Engine with exhaust gas treatment apparatus

0001The present invention relates to an engine having an exhaust gas treatment apparatus attached thereto and, more particularly, to an engine having an exhaust gas treatment apparatus attached thereto, which is capable of preventing an exhaust pipe from being damaged by a vibration of the main body of the engine.

0002The document <patcit id="pcit0001" dnum="JP2009012609A"><text>JP-A-2009-12609</text></patcit> discloses an engine having an exhaust gas treatment apparatus attached which is supported by the main body of the engine and the main body of the engine is configured to communicate with the exhaust gas treatment apparatus through an exhaust pipe. The exhaust gas treatment apparatus is thereby integrated with the main body of the engine. Accordingly the exhaust gas treatment apparatus is easily installed in a machine on which the engine is mounted.

0003However, the prior art is problematic in that the exhaust gas treatment apparatus is supported by the main body of the engine only in the exhaust pipe.

0004The exhaust gas treatment apparatus is supported with respect to the main body of the engine only by the exhaust pipe. Thus, if the exhaust gas treatment apparatus is shaken by vibration of the main body of the engine, the exhaust pipe is subject to severe loading and is likely to be damaged. In particular, in case where a diesel particulate filter (DPF) or a heavy catalyst is accommodated in the exhaust gas treatment apparatus, the problem becomes serious.

0005An object of the present invention is to provide an engine having an attached exhaust gas treatment apparatus an adapted to prevent unnecessary damage to an exhaust pipe by vibration of the main body of the engine. The invention is defined in the independent claim 1.

Description of the drawings

0006<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIGS. 1(A) to 1(C)</figref> are diagrams illustrating an engine having an exhaust gas treatment apparatus attached thereto according to a first embodiment of the present invention. <figref idref="f0001">FIG. 1(A)</figref> is a perspective view of the exhaust gas treatment apparatus and peripherals thereof seen from the upper side on the front right side. <figref idref="f0001">FIG. 1(B)</figref> is an exploded view of a portion indicated by an arrow B in <figref idref="f0001">FIG. 1(A). FIG. 1(C)</figref> is an exploded view of a portion indicated by an arrow C in <figref idref="f0001">FIG. 1(A)</figref>.</li><li><figref idref="f0002">FIG. 2(A)</figref> is a lateral view of the exhaust gas treatment apparatus of <figref idref="f0001">FIG. 1(A)</figref> and peripherals thereof, seen from the right side, and <figref idref="f0002">FIG. 2(B)</figref> is a cross-sectional view of <figref idref="f0002">FIG. 2(A)</figref> taken along line B-B.</li><li><figref idref="f0003">FIG. 3</figref> is a cross-sectional view of <figref idref="f0002">FIG. 2(A)</figref> taken along line W-W.</li><li><figref idref="f0004">FIGS. 4(A), 4(B), and 4(C)</figref> are diagrams illustrating the exhaust gas treatment apparatus of <figref idref="f0001">FIG. 1(A)</figref>. <figref idref="f0004">FIG. 4(A)</figref> is a longitudinal side view of a DPF accommodation casing unit seen from the right side, <figref idref="f0004">FIG. 4(B)</figref> is a lateral view of a ring-shaped spacer seen from the right side, and <figref idref="f0004">FIG. 4(C)</figref> is a lateral view of an exhaust inlet-side casing unit seen from the right side.</li><li><figref idref="f0005">FIGS. 5(A) and 5(B)</figref> are diagrams illustrating the exhaust gas treatment apparatus of <figref idref="f0001">FIG. 1(A)</figref>. <figref idref="f0005">FIG. 5(A)</figref> is a lateral side view of an exhaust outlet-side casing unit seen from the right side, and <figref idref="f0005">FIG. 5(B)</figref> is a lateral view of the DPF accommodation casing unit seen from the right side.</li><li><figref idref="f0006">FIGS. 6(A) to 6(C)</figref> are diagrams illustrating the exhaust gas treatment apparatus of <figref idref="f0001">FIG. 1(A)</figref>. <figref idref="f0006">FIG. 6(A)</figref> is a front view of the exhaust outlet-side casing unit, <figref idref="f0006">FIG. 6(B)</figref> is a cross-sectional view of <figref idref="f0006">FIG. 6(A)</figref> taken along line B-B, and <figref idref="f0006">FIG. 6(C)</figref> is an enlarged view of a portion indicated by an arrow C of <figref idref="f0006">FIG. 6(B)</figref>.</li><li><figref idref="f0007">FIG. 7</figref> is a front view of the exhaust gas treatment apparatus of <figref idref="f0001">FIG. 1(A)</figref>.</li><li><figref idref="f0008">FIG. 8</figref> is a perspective view of the engine having the exhaust gas treatment apparatus attached thereto relating to the first embodiment of the present invention, which is seen from the upper side on the front right side.</li><li><figref idref="f0009">FIG. 9</figref> is a perspective view of the engine, seen from the upper side on the front left side.</li><li><figref idref="f0010">FIG. 10</figref> is a lateral view of the engine of <figref idref="f0008">FIG. 8</figref>, seen from the right side.</li><li><figref idref="f0011">FIG. 11</figref> is a lateral view of the engine of <figref idref="f0008">FIG. 8</figref>, seen from the left side.</li><li><figref idref="f0012">FIG. 12</figref> is a front view of the engine of <figref idref="f0008">FIG. 8</figref>.</li><li><figref idref="f0013">FIG. 13</figref> is a plan view of the engine of <figref idref="f0008">FIG. 8</figref>.</li><li><figref idref="f0014">FIG. 14</figref> is a perspective view of an engine having an exhaust gas treatment apparatus attached thereto according to a second embodiment of the present invention, is seen from the upper side on the front right side.</li><li><figref idref="f0015">FIG. 15</figref> is a lateral view of the engine of <figref idref="f0014">FIG. 14</figref>, seen from the left side.</li><li><figref idref="f0016">FIG. 16</figref> is a front view the engine of <figref idref="f0014">FIG. 14</figref>.</li><li><figref idref="f0017">FIG. 17</figref> is a plan view of the engine of <figref idref="f0014">FIG. 14</figref>.</li><li><figref idref="f0018">FIG. 18</figref> is a lateral view of the engine of <figref idref="f0014">FIG. 14</figref>, seen from the right side.</li><li><figref idref="f0019">FIG. 19</figref> is a rear view of the engine of <figref idref="f0014">FIG. 14</figref>.</li><li><figref idref="f0020">FIG. 20</figref> is a diagram showing a tractor with the engine of <figref idref="f0014">FIG. 14</figref>.</li><li><figref idref="f0021">FIG. 21</figref> is a perspective view of an engine having an exhaust gas treatment apparatus attached thereto according to a third embodiment of the present invention, seen from the upper side on the front right side.</li><li><figref idref="f0022">FIG. 22</figref> is a lateral view of the engine of <figref idref="f0021">FIG. 21</figref>, seen from the left side.</li><li><figref idref="f0023">FIG. 23</figref> is a front view of the engine of <figref idref="f0021">FIG. 21</figref>.</li><li><figref idref="f0024">FIG. 24</figref> is a plan view of the engine of <figref idref="f0021">FIG. 21</figref>.</li><li><figref idref="f0025">FIG. 25</figref> is a lateral view of the engine of <figref idref="f0021">FIG. 21</figref>, seen from the right side.</li><li><figref idref="f0026">FIG. 26</figref> is a rear view of the engine of <figref idref="f0021">FIG. 21</figref>.</li><li><figref idref="f0027">FIG. 27</figref> is a lateral view showing a modification example of a support bracket used in the engine of <figref idref="f0021">FIG. 21</figref>.</li><li><figref idref="f0028">FIG. 28</figref> is a perspective view of the back part of an engine having an exhaust gas treatment apparatus attached thereto according to a fourth embodiment of the present invention, which is seen from the upper side on the front right side.</li><li><figref idref="f0029">FIG. 29</figref> is a lateral view of the back part of the engine of <figref idref="f0028">FIG. 28</figref>, seen from the right side.</li><li><figref idref="f0030">FIG. 30</figref> is a rear view of the engine of <figref idref="f0028">FIG. 28</figref>.</li></ul>

0007<b>General summary of the claimed subject-matter</b>

0008As illustrated in <figref idref="f0009">FIG. 9</figref>, in an engine having an exhaust gas treatment apparatus attached thereto, an exhaust gas treatment apparatus 4 is supported by an engine body 1, and the engine body 1 and the exhaust gas treatment apparatus 4 are configured to communicate with each other through an exhaust pipe 13, as illustrated in <figref idref="f0003">FIG. 3</figref>, a casing of the exhaust gas treatment apparatus 4 consists of a plurality of casing units 5, 6, and 7 separable from each other, connection flanges 8, 9, 10, and 11 are disposed in respective end portions of the casing units 5, 6, and 7, and the casing units 5, 6, and 7 are coupled together by a connection of the connection flanges 8, 9, 10, and 11, and As illustrated in <figref idref="f0008">FIGS. 8</figref>, <figref idref="f0014">14</figref>, <figref idref="f0021">21</figref>, and <figref idref="f0028">28</figref>, the exhaust gas treatment apparatus 4 is supported by the engine body 1 through the connection flanges 8, 9, 10, and 11.

0009As illustrated in <figref idref="f0008">FIGS. 8</figref>, <figref idref="f0014">14</figref>, <figref idref="f0021">21</figref>, and <figref idref="f0028">28</figref>, the exhaust gas treatment apparatus 4 is supported by the engine body 1 through the connection flanges 8, 9, 10, and 11. Accordingly, the exhaust gas treatment apparatus 4 is robustly supported by the engine body 1 through the connection flanges 8, 9, 10, and 11 having higher rigidity. Although the exhaust gas treatment apparatus 4 may be shaken by a vibration of the engine body 1, the load applied to the exhaust pipe 13 can be reduced and the likelihood of vibrational damage to the exhaust pipe 13 can be substantially reduced.

0010As illustrated in <figref idref="f0008">FIGS. 8</figref>, <figref idref="f0014">14</figref>, <figref idref="f0021">21</figref>, and <figref idref="f0028">28</figref>, the exhaust gas treatment apparatus 4 is supported by the engine body 1 through the plurality of connection flanges 8, 9, 10, and 11 which are spaced apart from each other. Although the exhaust gas treatment apparatus 4 may be shaken by vibration of the engine body 1, the load applied to each of the connection flanges 8, 9, 10, and 11 is distributed. Accordingly, the likelihood of vibrational damage to the connection flanges 8, 9, 10, and 11 of the exhaust gas treatment apparatus 4 can be substantially reduced.

0011As illustrated in <figref idref="f0008">FIGS. 8</figref>, <figref idref="f0014">14</figref>, and <figref idref="f0021">21</figref>, the load of the exhaust gas treatment apparatus 4 is supported by the support stays 2 and 3 through the support bracket 12, and the support bracket 12 is installed in the support stays 2 and 3 using bracket installation fastening members 14. Accordingly, the support bracket 12 can be easily installed in the support stays 2 and 3 without the need to support the weight of the exhaust gas treatment apparatus 4 using an external support device, such as a crane.

0012As illustrated in <figref idref="f0008">FIGS. 8</figref>, <figref idref="f0014">14</figref>, and <figref idref="f0021">21</figref>, the support stays 2 and 3 consist of the support stays 2 and 3 on the front and back sides, the support stays 2 and 3 on the front and back sides are respectively installed on the front and back sides of the engine body 1, the support bracket 12 is elongate in the forwards and backwards direction and is installed between the support stays 2 and 3 on the front and back sides, and the exhaust gas treatment apparatus 4 is supported by the engine body 1 through the support stays 2 and 3 on the front and back sides in the state in which the exhaust gas treatment apparatus 4 is elongate in the left and right direction. Thus, the disposition of the exhaust gas treatment apparatus 4 in the forward and backward directions can be freely set up.

0013As illustrated in <figref idref="f0001">FIGS. 1(A)</figref> and <figref idref="f0021">21</figref>, the front and back end portions of the support brackets 12a and 12b on the left and right sides are placed above the support stays 2 and 3 on the front and back sides and installed using bracket installation fastening members 14a and 14b on the left and right sides.

0014Accordingly, a robust outside structure with high strength can be constructed using the support brackets 12a and 12b on the left and right sides and the support stays 2 and 3 on the front and back sides. Furthermore, excessive shaking of the exhaust gas treatment apparatus 4 due to vibration of the engine body 1 can be avoided, and thus the connection flanges 8, 9, 10, and 11 can be protected from vibrational damage.

0015As illustrated in <figref idref="f0003">FIG. 3</figref>, in accommodating a DPF 17 in the exhaust gas treatment apparatus 4, as illustrated in <figref idref="f0010">FIGS. 10</figref>, <figref idref="f0015">15</figref>, <figref idref="f0020">20</figref>, and <figref idref="f0022">22</figref>, the exhaust gas treatment apparatus 4 is disposed on the upper side of a head cover 20 attached to the upper portion of a cylinder head 19. When the maintenance of the DPF 17 is performed, the exhaust gas treatment apparatus 4 or the DPF 17 can be taken out toward the upper side of the engine body 1 without intervening with the components of the engine body 1. Accordingly, the maintenance of the DPF 17 can be easily performed.

0016.As illustrated in <figref idref="f0010">FIGS. 10</figref>, <figref idref="f0015">15</figref>, <figref idref="f0020">20</figref>, and <figref idref="f0022">22</figref>, the exhaust gas treatment apparatus 4 is disposed at a position higher than the upper end portion 21 of the engine cooling fan 18 on the upper side of the head cover 20 attached to the cylinder head 19. Accordingly, the regeneration efficiency of the DPF 17 can be high because the DPF 17 is hardly cooled by the flow of cooling air.

0017As illustrated in <figref idref="f0009">FIGS. 9</figref>, <figref idref="f0014">14</figref>, and <figref idref="f0026">26</figref>, the exhaust inlet flange 23 of the exhaust gas treatment apparatus 4 is placed above the engine exhaust outlet flange 22 of the engine body 1. Accordingly, installing the exhaust inlet flange 23 in the engine exhaust outlet flange 22 can be easily performed without the need to support the load on the side of the exhaust inlet flange 23 using an external support device, such as a crane.

0018As illustrated in <figref idref="f0001">FIG. 1(A) and 1(B)</figref>, support brackets 12a and 12b are attached to the connection flanges 10 and 11 using bracket installation fastening members 25, position adjustment holes 26 of the bracket installation fastening members 25 are formed in at least one of the connection flanges 10 and 11 and the support brackets 12a and 12b, and the positions of at least upper and lower directions of the bracket installation fastening members 25 are adjusted using the position adjustment holes 26. Although the positions of the connection flanges 10 and 11 and the support brackets 12a and 12b are mutually deviated in the upper and lower directions, the attachment of the support brackets 12a and 12b to the connection flanges 10 and 11 can be performed without hindrance by up and down adjusting the positions of the bracket installation fastening members 25 using the position adjustment holes 26.

0019As illustrated in <figref idref="f0001">FIG. 1(B)</figref>, in the state in which the width direction of the engine body 1 is the left and right directions, a large-diameter hole 27 and a small-diameter hole 28 are overlapped with each other left and right, and the bracket installation fastening member 25 is inserted into the overlapped position and configured to pass therethrough.

0020Thus, if the connection flanges 10 and 11 and the support brackets 12a and 12b are aligned with each other, the bracket installation fastening members 25 are automatically aligned at a proper position. Accordingly, the attachment of the support brackets 12a and 12b to the connection flanges 10 and 11 can be easily performed without the need to adjust and manipulate the bracket installation fastening members 25.

0021As illustrated in <figref idref="f0001">FIG. 1(A) and 1(C)</figref>, the support brackets 12a and 12b are installed in the support stays 2 and 3 using respective bracket installation fastening members 14a and 14b, the position adjustment holes 29 of the bracket installation fastening members 14a and 14b are installed in at least one of the support brackets 12a and 12b and the support stays 2 and 3, and the positions of at least the forward and backward directions and the left and right directions of the bracket installation fastening members 14a and 14b are adjusted using the position adjustment holes 29. Although the positions of the support stays 2 and 3 and the support brackets 12a and 12b are mutually deviated in the forward and backward directions or the left and right directions, the positions of the bracket installation fastening members 14a and 14b can be adjusted using the position adjustment holes 29, and the installation of the support brackets 12a and 12b in the support stays 2 and 3 can be performed without hindrance.

0022As illustrated in <figref idref="f0001">FIG. 1(C)</figref>, the long hole 30 of the forward and backward directions and the long hole 31 of the left and right directions are overlapped with each other up and down in a crossing form, and the bracket installation fastening members 14a and 14b are inserted into the overlapping position and configured to pass therethrough. When the support brackets 12a and 12b and the support stays 2 and 3 are aligned with each other, the bracket installation fastening members 14 are automatically aligned at a proper position. Accordingly, a task of installing the support brackets 12a and 12b in the support stays 2 and 3 is facilitated.

0023As illustrated in <figref idref="f0003">FIGS. 3</figref>, <figref idref="f0014">14</figref>, <figref idref="f0021">21</figref>, and <figref idref="f0028">28</figref>, the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7 are detachably coupled to both ends of the DPF accommodation casing unit 5. If both ends of the DPF 17 are exposed by separating the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7 from the DPF accommodation casing unit 5, the maintenance of the DPF 17, such as washing of ashes accumulated in the DPF 17, can be performed.

0024As illustrated in <figref idref="f0001">FIGS. 1(A)</figref> and <figref idref="f0028">28</figref>, in the state in which the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7 are supported by the engine body 1, the DPF accommodation casing unit 5 can be pulled out between the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7. Accordingly, the maintenance of the DPF 17, such as washing of ashes accumulated in the DPF 17, can be easily performed.

0025As illustrated in <figref idref="f0001">FIGS. 1(A)</figref> and <figref idref="f0028">28</figref>, the pull-up locking units 36 and 37 of the DPF accommodation casing unit 5 are installed in the pull-up protrusions 34 and 35. Accordingly, the maintenance of the DPF can be easily performed because the DPF accommodation casing unit 5 can be simply pulled up using an external support device, such as a crane.

0026As illustrated in <figref idref="f0002">FIGS. 2 (A) and (B)</figref>, a flange-fit concave unit 38b having an upper portion opened is installed in the support bracket 12b, and the lower edge portion of at least one of the connection flanges 9 and 11 where the DPF accommodation casing unit 5 and the exhaust outlet-side casing unit 7 overlap with each other is fitted into the flange-fit concave unit 38b. Accordingly, the exhaust gas treatment apparatus 4 and the support bracket 12 can be easily aligned with each other.

0027In the engine as described in the foregoing paragraphs, the exhaust gas treatment apparatus can be compacted. As illustrated in <figref idref="f0003">FIG. 3</figref>, a ring-shaped spacer 39 may be inserted between the connection flanges 8 and 10 of the DPF accommodation casing unit 5 and the exhaust inlet-side casing unit 6, and a DPF inlet-side space 40 may be formed within the ring-shaped spacer 39. As illustrated in <figref idref="f0004">FIGS. 4(B)</figref> and <figref idref="f0028">28</figref>, a sensor installation hole 41 may be formed in the ring-shaped spacer 39, and an exhaust sensor 42 may be inserted from the sensor installation hole 41 toward the DPF inlet-side space 40. Accordingly, the exhaust gas treatment apparatus 4 can be compacted because the DPF inlet-side space 40 can be narrowed.

0028However, if a sensor installation boss were installed on the peripheral wall of a DPF accommodation casing unit using welding, all the peripheral edge portions of the sensor installation boss would need to be welded, and a space through which a welding torch can enter would be needed between the sensor installation boss and the connection flange of a DPF welding casing unit. Accordingly, the distance between the connection flange and a sensor would be widened, and an exhaust inlet-side space have to be widened, resulting in an increase in size of the exhaust gas treatment apparatus.

0029As illustrated in <figref idref="f0001">FIGS. 1(A)</figref> and <figref idref="f0028">28</figref>, the posture of the ring-shaped spacer 39 can be changed in the circumferential direction and thus the position and posture of the sensor installation hole 41 can be changed. Accordingly, the disposition and posture of the exhaust sensor 42 can be freely selected.

0030As illustrated in <figref idref="f0006">FIGS. 6(C)</figref>, <figref idref="f0014">14</figref>, <figref idref="f0021">21</figref>, and <figref idref="f0028">28</figref>, a pipe installation boss 46 having the exhaust pressure entrance pipe 45 of an exhaust pressure sensor 44 installed therein may be installed in the peripheral wall of the exhaust outlet-side casing unit 7, and the boss hole 47 of the pipe installation boss 46 may be upwardly formed externally. Thus, condensation water remaining in the exhaust outlet-side casing unit 7 can be prevented from entering the exhaust pressure entrance pipe 45 of the exhaust pressure sensor 44, and thus the erroneous detection by the exhaust pressure sensor 44 can be prevented.

0031As illustrated in <figref idref="f0004">FIGS. 4(C)</figref>, <figref idref="f0014">14</figref>, <figref idref="f0021">21</figref>, and <figref idref="f0028">28</figref>, the posture of the exhaust inlet-side casing unit 6 can be changed in the circumferential direction and thus the direction of an inlet 48a of the exhaust inlet pipe 48 can be changed. Accordingly, the disposition of an exhaust path on the upper stream side of the exhaust inlet pipe 48 can be freely selected.

0032As illustrated in <figref idref="f0005">FIGS. 5(A), 5(B)</figref>, <figref idref="f0014">14</figref>, <figref idref="f0025">25</figref>, and <figref idref="f0028">28</figref>, the posture of the exhaust outlet-side casing unit 7 can be changed in the circumferential direction and thus the direction of an outlet 49a of the exhaust outlet pipe 49 can be changed. Accordingly, the disposition of an exhaust path on the lower stream side of the exhaust outlet pipe 49 can be freely selected.

0033As illustrated in <figref idref="f0028">FIGS. 28</figref> and <figref idref="f0029">29</figref>, the exhaust gas treatment apparatus 4 has a long posture in the left and right directions, and the DPF accommodation casing unit 5 is disposed on the upper back side of a flywheel housing 51 immediately after the head cover 20 attached to the upper portion of the cylinder head 19. When the maintenance of the DPF 17 is performed, the exhaust gas treatment apparatus 4 or the DPF accommodation casing unit 5 can be taken out toward the upper side of the engine body 1 without intervening with the components of the engine body 1. Accordingly, the maintenance of the DPF 17 can be easily performed.

0034As illustrated in <figref idref="f0028">FIGS. 28</figref> and <figref idref="f0029">29</figref>, in the state in which the exhaust gas treatment apparatus 4 has a long posture in the left and right directions, the DPF accommodation casing unit 5 of the exhaust gas treatment apparatus 3 is disposed on the upper back side of the flywheel housing 51 immediately after the head cover 20 attached to the upper portion of the cylinder head 19. Accordingly, the total height of the engine can be kept low.

0035As illustrated in <figref idref="f0008">FIG. 8</figref>, the engine cooling fan 21 is disposed in the front part of the engine body 1. As illustrated in <figref idref="f0028">FIGS. 28</figref> and <figref idref="f0029">29</figref>, in the state in which the exhaust gas treatment apparatus 4 is elongate in the left and right directions, the DPF accommodation casing unit 5 of the exhaust gas treatment apparatus 4 is disposed on the upper back side of the flywheel housing 51 immediately after the head cover 20 attached to the upper portion of the cylinder head 19. Accordingly, the regeneration efficiency of the DPF can be high because the DPF 17 is hardly cooled by air flowing over the engine.

Detailed description

0036<figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008 f0009 f0010 f0011 f0012 f0013 f0014 f0015 f0016 f0017 f0018 f0019 f0020 f0021 f0022 f0023 f0024 f0025 f0026 f0027 f0028 f0029 f0030">FIGS. 1 to 30</figref> are diagrams illustrating an engine having an exhaust gas treatment apparatus attached thereto relating to embodiments of the present invention. <figref idref="f0001 f0002 f0003 f0004 f0005 f0006 f0007 f0008 f0009 f0010 f0011 f0012 f0013">FIGS. 1 to 13</figref> are diagrams illustrating a first embodiment, <figref idref="f0014 f0015 f0016 f0017 f0018 f0019 f0020">FIGS. 14 to 20</figref> are diagrams illustrating a second embodiment, <figref idref="f0021 f0022 f0023 f0024 f0025 f0026 f0027">FIGS. 21 to 27</figref> are diagrams illustrating a third embodiment, and <figref idref="f0028 f0029 f0030">FIGS. 28 to 30</figref> are diagrams illustrating a fourth embodiment. In each of the embodiments, a water-cooling vertical in-line multi-cylinder diesel engine having a DPF muffler attached thereto is described.

0037The construction of the first embodiment is described below. As shown in <figref idref="f0008">FIG. 8</figref>, in the state in which a direction along which a crank shaft center line 16 extends is forward and backward directions and the width direction of an engine body 1 orthogonal to the crank shaft center line 16 is left and right directions, the engine body 1 has a cylinder head 19 attached above a cylinder block 52, a head cover 20 attached above the cylinder head 19, an oil pan 53 attached under the cylinder block 52, a coolant pump 54 attached in front of the cylinder block 52, an engine cooling fan 18 disposed in front of the coolant pump 54, a gear casing 15 disposed in the rear of the cylinder block 52, a flywheel housing 51 disposed in the rear of the gear casing 15, a suction manifold 56 attached on the right side of the cylinder head 19, and an exhaust manifold 55 attached on the left side of the cylinder head 19 as shown in <figref idref="f0009">FIG. 9</figref>.

0038As shown in <figref idref="f0008">FIG. 8</figref>, the engine cooling fan 18 is disposed in the input axis of the coolant pump 54, and the coolant pump 54 and the engine cooling fan 18 are driven by a belt transmission device from the crank shaft. The engine body 1 is equipped with an EGR apparatus (i.e., exhaust gas recirculation system) and a common rail fuel injection system. The EGR apparatus reduces some of an exhaust gas into a suction gas. The common rail fuel injection system accumulates fuel, boosted by the fuel supply pump 57, in a common rail 58 and controls a fuel injection time or a fuel injection amount of each cylinder by opening or closing the electromagnetic valve of an injector through electronic control.

0039As shown in <figref idref="f0008">FIG. 8</figref>, in the EGR apparatus, an EGR valve casing 59 is attached above the suction manifold 56 and configured to communicate with the exhaust manifold 55 through an EGR cooler 60. As shown in <figref idref="f0010">FIG. 10</figref>, the EGR cooler 60 is disposed immediately after the cylinder head 19 and immediately above a flywheel housing 51.

0040As shown in <figref idref="f0008">FIG. 8</figref>, the common rail fuel injection system is configured to have the common rail 58 disposed under the suction manifold 56 and to pump fuel from a fuel supply pump 57 to the common rail 58 and supply fuel, compressed by the common rail 58, to the injector through the high pressure pipe 61. The fuel supply pump 57 is disposed on the front side of the gear casing 15 in the right direction of the cylinder block 52.

0041As shown in <figref idref="f0009">FIG. 9</figref>, an exhaust gas treatment apparatus 4 is supported by the engine body 1, and the engine body 1 and the exhaust gas treatment apparatus 4 are configured to communicate with each other through an exhaust pipe 13. A super charger 62 is attached above the exhaust manifold 55, and the exhaust pipe 13 of an elbow form is coupled to the exhaust outlet of an exhaust turbine 63 of the super charger 62.

0042As shown in <figref idref="f0003">FIG. 3</figref>, a DOC 64 and a DPF 17 are accommodated in the exhaust gas treatment apparatus 4. The DOC 64 is disposed on the upper stream side of the exhaust gas treatment apparatus 4, and the DPF 17 is disposed on the lower stream side thereof. The DOC is an abbreviation of a diesel oxidization catalyst, and the DPF is an abbreviation of a diesel particulate filter. In the exhaust gas treatment apparatus 4, the DPF 17 is configured to capture PM (particle materials) included in an exhaust gas, oxidize non-combustion fuel, drained out from a combustion chamber or sprayed to an exhaust path, using the DOC 64, raise temperature of the exhaust gas using oxidization heat, and incinerate the PM accumulated in the DPF 17 using the raised temperature, thereby contriving the regeneration of the DPF 17. The DPF muffler is used in the exhaust gas treatment apparatus 4 in the present embodiment, but an exhaust muffler or a catalyst converter which does not include the DPF may be used as the exhaust gas treatment apparatus 4.

0043As shown in <figref idref="f0003">FIG. 3</figref>, the casing of the exhaust gas treatment apparatus 4 consists of a plurality of casing units 5, 6, and 7 which can be separated from each other. Connection flanges 8, 9, 10, and 11 are installed at the end of each of the casing units 5, 6, and 7. The casing units 5, 6, and 7 are coupled by a connection of the connection flanges 8, 9, 10, and 11. As shown in <figref idref="f0008">FIG. 8</figref>, the exhaust gas treatment apparatus 4 is supported by the engine body 1 through the connection flanges 8, 9, 10, and 11.

0044As shown in <figref idref="f0003">FIG. 3</figref>, the casing of the exhaust gas treatment apparatus 4 consists of three casing units; the DPF accommodation casing unit 5, the exhaust inlet-side casing unit 6, and the exhaust outlet-side casing unit 7. The DPF accommodation casing unit 5 accommodates the DPF 17, and the exhaust inlet-side casing unit 6 accommodates the DOC 64. The DPF inlet-side connection flange 8 and the DPF outlet-side connection flange 9 are disposed on both ends of the DPF accommodation casing unit 5. The exhaust inlet-side connection flange 10 is disposed at the end of the DPF inlet side of the exhaust inlet-side casing unit 6, and the exhaust outlet-side connection flanges 11 is disposed at the end of the DPF outlet side of the exhaust outlet-side casing unit 7.

0045Between the DPF inlet-side connection flange 8 and the exhaust inlet-side connection flange 10, a ring-shaped spacer 39 is inserted, and the connection flanges 8 and 10 and the ring-shaped spacer 39 are overlapped with each other and fastened by flange connection fastening members 43 on the DPF inlet side. Furthermore, the DPF outlet-side connection flange 9 and the exhaust outlet-side connection flange 11 are overlapped with each other and fastened by flange connection fastening members 50 on the DPF outlet side. All the flange connection fastening members 43 and 50 are bolts and nuts.

0046As shown in <figref idref="f0008">FIG. 8</figref>, the exhaust gas treatment apparatus 4 is supported by the engine body 1 through the plurality of connection flanges 8, 9, 10, and 11 which are spaced apart from each other. The plurality of connection flanges 8, 9, 10, and 11 includes the DPF inlet-side connection flange 8 and the DPF outlet-side connection flange 9 of the DPF accommodation casing unit 5, the exhaust inlet-side connection flange 10 of the exhaust inlet-side casing unit 6, and the exhaust outlet-side connection flange 11 of the exhaust outlet-side casing unit 7.

0047As shown in <figref idref="f0008">FIG. 8</figref>, support stays 2 and 3 are installed in the engine body 1, a support bracket 12 is attached to the connection flanges 10 and 11, and the support bracket 12 is disposed above the support stays 2 and 3. The load of the exhaust gas treatment apparatus 4 is supported by the support stays 2 and 3 through the support bracket 12, and the support bracket 12 is installed in the support stays 2 and 3 using bracket installation fastening members 14.

0048As shown in <figref idref="f0008">FIG. 8</figref>, the support stays 2 and 3 consist of the front and rear support stays 2 and 3, the front and rear support stays 2 and 3 are installed on the front and back sides of the engine body 1, the support bracket 12 is lengthily formed forward and backward, the support bracket 12 is disposed between the front and rear support stays 2 and 3, and the exhaust gas treatment apparatus 4 is supported by the engine body 1 through the front and rear support stays 2 and 3 in a long posture in the left and right directions.

0049As shown in <figref idref="f0001">FIG. 1(A)</figref>, the support bracket 12 consists of support brackets 12a and 12b on the left and right sides, and the support brackets 12a and 12b are respectively attached to the connection flanges 8, 10 and 9, 11 on the left and right sides. The front and rear ends of the support brackets 12a and 12b are disposed on the front and rear support stays 2 and 3 and fastened by bracket installation fastening members 14a and 14b on the left and right sides.

0050As shown in <figref idref="f0002">FIG. 2(A)</figref>, the front support stay 2 is formed by bending a horizontal placement unit 2b from the upper end of a vertical stay installation unit 2a toward the back side. Furthermore, the rear support stay 3 is formed by bending a horizontal placement unit 3b from the upper end of a vertical stay installation unit 3a toward the back side. As shown in <figref idref="f0010">FIG. 10</figref>, the stay installation units 2a and 3a of the respective front and rear support stays 2 and 3 are installed in the front and rear end faces of the cylinder head 19. As shown in <figref idref="f0002">FIG. 2(B)</figref>, the support bracket 12a on the left side is formed by bending a vertical support unit 12d from the left edge of a horizontal bracket installation unit 12c toward an upper side. The right support bracket 12b is formed by bending a vertical support unit 12d from the right edge of a horizontal bracket installation unit 12c toward an upper side.

0051As shown in <figref idref="f0001">FIGS. 1(A) and 1(C)</figref>, the front end portions of the bracket installation units 12c and 12c of the support brackets 12a and 12b on the left and right sides are placed on the placement unit 2b of the front support stay 2. The front end portions are fastened by the bracket installation fastening members 14a and 14b on the left and right sides. As shown in <figref idref="f0002">FIG. 2(A) and 2(B)</figref>, the rear end portions of the bracket installation units 12c and 12c of the support brackets 12a and 12b on the left and right sides are placed on the placement unit 3b of the rear support stay 3. The rear end portions are fastened by the bracket installation fastening members 14a and 14b on the left and right sides. The bracket installation fastening members 14a and 14b are bolts and nuts.

0052As shown in <figref idref="f0010">FIG. 10</figref>, on the upper side of the head cover 20 attached above the cylinder head 19, the exhaust gas treatment apparatus 4 is disposed in a place higher than the upper end portion 21 of the engine cooling fan 18. As shown in <figref idref="f0009">FIG. 9</figref>, the exhaust inlet flange 23 of the exhaust gas treatment apparatus 4 is placed on the engine exhaust outlet flange 22 on the side of the engine body 1. The engine exhaust outlet flange 22 is formed toward the upper side of the end of the exhaust pipe 13. The exhaust inlet flange 23 is formed toward the lower side of the leading end of the exhaust inlet pipe 48 of the exhaust gas treatment apparatus 4.

0053As shown in <figref idref="f0001">FIGS. 1(A) and 1(B)</figref>, the support brackets 12a and 12b on the left and right sides are attached to the connection flanges 10 and 11 using bracket installation fastening members 25. The position adjustment holes 26 of the bracket installation fastening members 25 are formed in at least one of the connection flanges 10 and 11 and the support brackets 12a and 12b. The positions of at least upper and lower directions of the bracket installation fastening members 25 are adjusted by the position adjustment holes 26. As shown in <figref idref="f0002">FIG. 2(B)</figref>, in the present embodiment, the support brackets 12a and 12b on the left and right sides are respectively attached to the exhaust inlet-side connection flange 10 of the exhaust inlet-side casing unit 6 and the exhaust outlet-side connection flange 11 of the exhaust outlet-side casing unit 7. The position adjustment holes 26 of the bracket installation fastening members 25 are formed in the support brackets 12a and 12b.

0054As shown in <figref idref="f0001">FIG. 1(B)</figref>, the position adjustment hole 26 of the bracket installation fastening member 25 is a large-diameter hole 27. The large-diameter holes 27 are formed in one of the connection flanges 10 and 11 and the support bracket 12, and small-diameter holes 28 are formed in the other of the connection flanges 10 and 11 and the support bracket 12. The inside diameter of the large-diameter hole 27 is set to a size in which a portion through which the bracket installation fastening member 25 inserted therein passes can be moved and adjusted in a direction orthogonal to the direction in which the bracket installation fastening member 25 passes. The inside diameter of the small-diameter hole 28 is set to a size in which a portion through which the bracket installation fastening member 25 inserted therein passes cannot be moved and adjusted in a direction orthogonal to the direction in which the bracket installation fastening member 25 passes. In the state in which the width direction of the engine body 1 is left and right directions, the large-diameter hole 27 and the small-diameter hole 28 overlap with each other left and right, and the bracket installation fastening member 25 is inserted into the overlapping position and passes through the overlapping position.

0055As shown in <figref idref="f0001">FIGS. 1(A) and 1(C)</figref>, the support brackets 12a and 12b are attached to the support stays 2 and 3 using the bracket installation fastening members 14a and 14b. The position adjustment holes 29 of the bracket installation fastening members 14a and 14b are formed in at least one of the support brackets 12a and 12b and the support stays 2 and 3. The positions of at least the forward and backward directions and left and right directions of the bracket installation fastening members 14a and 14b are adjusted through the position adjustment holes 29.

0056As shown in <figref idref="f0001">FIG. 1(C)</figref>, in the present embodiment, the position adjustment holes 29 are formed in the front end portion of the support bracket 12a on the left side and in the front support stay 2 on both sides of the left side. The positions of the forward and backward directions and the left and right directions of the bracket installation fastening members 14a on the left side are adjusted through the position adjustment holes 29. The rear end portion of the support bracket 12a on the left side, the front and rear end portions of the support bracket 12b of the left and right sides of the rear support stay 3, and the right side of the pair of front and rear support stays 2 and 3 have the same construction. The positions of the forward and backward directions and the left and right directions of the bracket installation fastening members 14a and 14b are adjusted through the position adjustment holes 29.

0057As shown in <figref idref="f0001">FIG. 1(C)</figref>, the position adjustment holes 29 of the bracket installation fastening members 14a and 14b consist of a long hole 30 in the forward and backward directions and a long hole 31 in the left and right directions. The long holes 30 of the forward and backward directions are formed in one of the support stays 2 and 3 and the support brackets 12a and 12b, and the long holes 31 of the left and right directions are formed in the other of the support stays 2 and 3 and the support brackets 12a and 12b. The long holes 30 of the forward and backward directions and the long holes 31 of the left and right directions overlap with each other up and down in a crossing form. The bracket installation fastening members 14a and 14b are inserted into the overlapping positions and configured to pass therethrough. As shown in <figref idref="f0001">FIG. 1(C)</figref>, in the present embodiment, the long holes 30 of the forward and backward directions are formed in the support stays 2 and 3 on the front and back sides, and the long holes 31 of the left and right directions are formed in the support brackets 12a and 12b on the left and right sides.

0058As shown in <figref idref="f0003">FIG. 3</figref>, the DPF 17 is accommodated in the exhaust gas treatment apparatus 4. The casing of the exhaust gas treatment apparatus 4 is formed of the DPF accommodation casing unit 5, the exhaust inlet-side casing unit 6, and the exhaust outlet-side casing unit 7. The exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7 are connected to both ends of the DPF accommodation casing unit 5 so that they can be separated from each other.

0059As shown in <figref idref="f0002">FIG. 2(B)</figref>, the connection flanges 8 and 9 of the DPF accommodation casing unit 5 overlap with the respective connection flanges 10 and 11 of the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7. Support protrusions 32 and 33 are outwardly more protruded than the respective connection flanges 8 and 9 of the DPF accommodation casing unit 5 in the diameter direction and formed in the respective connection flanges 10 and 11 of the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7. The exhaust gas treatment apparatus 4 is supported by the engine body 1 through the support protrusions 32 and 33.

0060As shown in <figref idref="f0001">FIG. 1(A)</figref>, in the state in which the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7 are supported by the engine body 1, the DPF accommodation casing unit 5 can be pulled out between the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7. As shown in <figref idref="f0004">FIGS. 4(B) and 4(C)</figref>, the ring-shaped spacer 39 is detachably installed in the exhaust inlet-side connection flange 10 of the exhaust inlet-side casing unit 6 using an installation bolt 69. However, the ring-shaped spacer 39 is not detached from the exhaust inlet-side connection flange 10 when the DPF accommodation casing unit 5 is pulled out between the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7.

0061As shown in <figref idref="f0001">FIG. 1(A)</figref>, pull-up protrusions 34 and 35 are outwardly more protruded than the connection flanges 10 and 11 of the exhaust inlet-side casing unit 6 and the exhaust outlet-side casing unit 7 in the diameter direction and installed in the respective connection flanges 8 and 9 of the DPF accommodation casing unit 5. The pull-up locking units 36 and 37 of the DPF accommodation casing unit 5 are installed in the respective pull-up protrusions 34 and 35.

0062As shown in <figref idref="f0002">FIGS. 2(A) and 2(B)</figref>, a flange-fit concave unit 38b having an upper portion opened is formed in the support bracket 12b on the right side. The lower edge portion of at least one of the connection flanges 9 and 11 at which the DPF accommodation casing unit 5 and the exhaust outlet-side casing unit 7 overlap with each other is fitted into the flange-fit concave unit 38b.

0063As shown in <figref idref="f0003">FIG. 3</figref>, in the present embodiment, the lower edge portions of both sides of the connection flanges 9 and 11 of the DPF accommodation casing unit 5 and the exhaust outlet-side casing unit 7 are fitted into the flange-fit concave unit 38b. As shown in <figref idref="f0002">FIG. 2(B)</figref>, a flange-fit concave unit 38a having an upper portion opened is also formed in the support bracket 12a on the left side. The lower edge portion of at least one of the connection flange 10 of the DPF inlet-side casing unit 6 and the ring-shaped spacer 39 which overlap with each other is fitted into the flange-fit concave unit 38a. The inner peripheral edges of the flange-fit concave units 38a and 38b are formed in a curved shape along the connection flanges 9, 10, and 11 of a polygon or the intersecting corner of a lower edge portion of the ring-shaped spacer 39. Since the lower edge portions are fitted into the flange-fit concave units 38a and 38b as described above, the position of the exhaust gas treatment apparatus 4 in the forward and backward directions and the rotation and posture of the exhaust gas treatment apparatus 4 are determined.

0064As shown in <figref idref="f0003">FIG. 3</figref>, the ring-shaped spacer 39 is inserted between the connection flanges 8 and 10 of the DPF accommodation casing unit 5 and the exhaust inlet-side casing unit 6, and DPF inlet-side space 40 is formed in the ring-shaped spacer 39. As shown in <figref idref="f0004">FIG. 4(B)</figref>, a sensor installation hole 41 is formed in the ring-shaped spacer 39. An exhaust sensor 42 is inserted from the sensor installation hole 41 toward the DPF inlet-side space 40.

0065The exhaust sensor 42 is an exhaust temperature sensor on the DPF inlet side. As shown in <figref idref="f0004">FIG. 4(B)</figref>, a pipe installation hole 66 in which the DPF inlet-side exhaust pressure entrance pipe 65 of an exhaust pressure sensor 44 shown in <figref idref="f0001">FIG. 1(A)</figref> is installed is formed in the ring-shaped spacer 39. The pipe installation hole 66 is upwardly formed externally so that condensation water within the DPF inlet-side space 40 does not flow into the DPF inlet-side exhaust pressure entrance pipe 65.

0066As shown in <figref idref="f0004">FIGS. 4(A) and 4(C)</figref>, a plurality of locked units 8a and 10a is disposed in the respective connection flanges 8 and 10 where the DPF accommodation casing unit 5 and the exhaust inlet-side casing unit 6 overlap with each other and arranged in their circumferential direction at equal spaced angles. As shown in <figref idref="f0004">FIG. 4(B)</figref>, a plurality of locked units 39a is disposed in the ring-shaped spacer 39 and arranged in their circumferential direction at equal spaced angles. The posture of the ring-shaped spacer 39 is moved in the circumferential direction in the unit of the equal spaced angle, and the locked units 39a of the ring-shaped spacer 39 are aligned with the respective locked units 8a and 10a of the connection flanges 8 and 10. In this state, if the locked units 8a and 10a of the connection flanges 8 and 10 are locked into the locked units 39a of the ring-shaped spacer 39 using the flange connection fastening members 43, the posture of the ring-shaped spacer 39 can be changed in the circumferential direction and thus the position and posture of the sensor installation hole 41 can be changed.

0067As shown in <figref idref="f0006">FIG. 6(C)</figref>, a pipe installation boss 46 in which the exhaust pressure entrance pipe 45 of the exhaust pressure sensor 44 is installed is disposed in the peripheral wall of the exhaust outlet-side casing unit 7. The boss hole 47 of the pipe installation boss 46 is upwardly formed externally.

0068As shown in <figref idref="f0001">FIG. 1(A)</figref>, the exhaust pressure entrance pipe 45 is disposed on the DPF outlet side and configured to communicate with the exhaust pressure entrance pipe 65 on the DPF inlet side and the exhaust pressure sensor 44. The exhaust pressure sensor 44 detects a difference in the pressure between the inlet side and the outlet side of the DPF 17. An engine ECU estimates the amount of PM accumulated in the DPF 17 on the basis of the detection value. The ECU is an abbreviation of an electronic control unit.

0069As shown in <figref idref="f0004">FIG. 4(C)</figref>, an exhaust inlet pipe 48 is installed in the exhaust inlet-side casing unit 6. The plurality of locked units 8a and 10a is disposed in the connection flanges 8 and 10 where the DPF accommodation casing unit 5 and the exhaust inlet-side casing unit 6 overlap with each other and arranged in their circumferential direction at equal spaced angles. The exhaust inlet-side casing unit 6 is moved in the circumferential direction in the unit of the equal spaced angle. The locked units 10a of the connection flange 10 of the exhaust inlet-side casing unit 6 are aligned with the respective locked units 8a of the connection flange 8 of the DPF accommodation casing unit 5 and then fastened using the flange connection fastening members 43. Accordingly, the posture of the exhaust inlet-side casing unit 6 can be changed in the circumferential direction, and thus the direction of an inlet 48a of the exhaust inlet pipe 48 can be changed.

0070As shown in <figref idref="f0004">FIGS. 4(A) and 4(C)</figref>, the bolt insertion through holes of the flange connection fastening members 43 are formed in the locked units 8a and 10a. The bolt insertion through holes of the flange connection fastening members 43 are spaced apart from each other at equal angles of 36° and formed at 10 places in the circumferential direction. As shown in <figref idref="f0001">FIG. 1(A)</figref>, the sensor installation hole 67 for an exhaust sensor is formed in the peripheral wall of the exhaust inlet-side casing unit 6. An exhaust gas temperature sensor for detecting the temperature of an exhaust gas on the upper stream side of the DOC is disposed in the sensor installation hole 67.

0071As shown in <figref idref="f0005">FIGS. 5(A) and 5(B)</figref>, an exhaust outlet pipe 49 is installed in the exhaust outlet-side casing unit 7. A plurality of locked units 11a and 9a is disposed in each of the connection flanges 11 and 9 where the exhaust outlet-side casing unit 7 and the DPF accommodation casing unit 5 overlap with each other and arranged in their circumferential direction at equal spaced angles. The exhaust outlet-side casing unit 7 is moved in the circumferential direction in the unit of the equal spaced angle, and the locked units 11a of the connection flange 11 of the exhaust outlet-side casing unit 7 are aligned with the respective locked units 9a of the connection flange 9 of the DPF accommodation casing unit 5 and then fastened using respective flange connection fastening members 50. Accordingly, the posture of the exhaust outlet-side casing unit 7 can be changed in the circumferential direction, and the direction of an outlet 49a of the exhaust outlet pipe 49 can be changed.

0072As shown in <figref idref="f0005">FIGS. 5(A) and 5(B)</figref>, the bolt insertion through holes of the flange connection fastening members 50 are formed in the locked units 11a and 9a. The bolt insertion through holes of the flange connection fastening members 50 are spaced apart from each other at equal angles of 36° and formed at 10 places in the circumferential direction. As shown in <figref idref="f0001">FIG. 1(A)</figref>, a sensor installation hole 68 for an exhaust sensor is formed in the peripheral wall of the exhaust outlet-side casing unit 7. An exhaust gas temperature sensor for detecting the temperature of an exhaust gas on the lower stream side of the DPF can be disposed in the sensor installation hole 68.

0073Second and third embodiments shown in <figref idref="f0014 f0015 f0016 f0017 f0018 f0019 f0020 f0021 f0022 f0023 f0024 f0025 f0026 f0027">FIGS. 14 to 27</figref> relate to a diesel engine having an exhaust gas treatment apparatus attached thereto, which is specialized for a tractor. The diesel engine is mounted on the following tractor vehicle 102. As shown in <figref idref="f0020">FIG. 20</figref>, the tractor vehicle 102 includes an engine body 1, a clutch housing, a transmission casing, a front axle frame 105, and so on which are coupled in series. A bonnet 107 is formed to generally surround various equipments attached to its peripherals, engine auxiliary equipments, etc. starting from the engine body 1. The ceiling unit 107a of the bonnet 107 is configured to be the highest in its back part and lowered in its front part. That is, the ceiling unit 107a is disposed in a tilt fashion in which the back part becomes gradually high from the front part to the back part.

0074Furthermore, as shown in <figref idref="f0020">FIG. 20</figref>, a cabin 108 is disposed above the tractor vehicle 102 in the back side of the engine body 1, and a cockpit having a handle and a driver's seat disposed therein is formed in the cabin 108. The engine body 1 has a crank shaft center line 16 disposed in the forward and backward directions. An engine cooling fan 18, a radiator 112, a battery 113, and the like are disposed above the front axle frame 105 in front of the engine body 1.

0075As shown in <figref idref="f0020">FIG. 20</figref>, a shroud 115 of a cylindrical shape is backwardly protruded in the radiator 112. The front part of the engine cooling fan 18 is disposed within the shroud 115. Furthermore, an air cleaner 116 is disposed above the battery 113. A clean air suction pipe 118 led out from the air cleaner 116 is coupled to the suction manifold 56 of the engine body 1 shown in <figref idref="f0018">FIG. 18</figref> so that it communicates therewith.

0076The construction of the second embodiment shown in <figref idref="f0014 f0015 f0016 f0017 f0018 f0019 f0020">FIGS. 14 to 20</figref> is described below. As shown in <figref idref="f0015">FIG. 15</figref>, the EGR apparatus has an EGR cooler 60 and an EGR gas lead-out pipe 135 disposed in an EGR gas lead-out passage 133 and an EGR valve casing 59 disposed on the down stream side of the EGR gas lead-out pipe 135. As shown in <figref idref="f0018">FIG. 18</figref>, an EGR gas inlet pipe 137 is led out from the suction manifold 56. A shown in <figref idref="f0015">FIG. 15</figref>, an exhaust gas treatment apparatus 4 is coupled to a super charger 62, attached to an exhaust manifold 55, through a flange. The exhaust gas treatment apparatus 4 is a DPF muffler, but it has a larger external size and heavier weight than a conventional muffler. The weight of the exhaust gas treatment apparatus 4 is 20 to 30 Kg which is 4 to 6 times greater than that of the conventional muffler.

0077As shown in <figref idref="f0015">FIG. 15</figref>, the exhaust gas treatment apparatus 4 is disposed above the back part of the engine body 1 covering the bonnet 107 so that the length direction of the exhaust gas treatment apparatus 4 is oriented left and right. The exhaust gas treatment apparatus 4 is disposed in the space having the largest gap in the upper and lower directions between the engine body 1 and the ceiling unit 107a of the bonnet 107. As shown in <figref idref="f0016">FIG. 16</figref>, as in the first embodiment, the casing of the exhaust gas treatment apparatus 4 is divided into three parts; a DPF accommodation casing unit 5, an exhaust inlet-side casing unit 6 on the left side, and an exhaust outlet-side casing unit 7 on the right side. Connection flanges 8 and 9 are formed in the DPF accommodation casing unit 5 placed in a central portion and configured to flange-couple the casing units 6 and 7 on the left and right sides. Connection flanges 10 and 11 corresponding to the connection flanges 8 and 9 are formed at the respective end portions of the casing units 6 and 7 on the left and right sides. The casing units 6 and 7 on the left and right sides are coupled to the DPF accommodation casing unit 5 placed in a central portion by means of the connection flanges 8 and 10 and the connection flanges 9 and 11.

0078As shown in <figref idref="f0019">FIG. 19</figref>, an exhaust inlet pipe 48 is downwardly protruded from the exhaust inlet-side casing unit 6 on the left side and coupled to the exhaust manifold 55 of the engine body 1 through the super charger 39. An exhaust outlet pipe 49 is downwardly led out from the exhaust outlet-side casing unit 7 on the right side and coupled to an exhaust pipe 150. A longitudinal pipe 149 shown in <figref idref="f0014">FIGS. 14</figref> and <figref idref="f0017">17</figref> is coupled to the exhaust pipe 150. The longitudinal pipe 149 is disposed on the side of a back part of the engine body 1. As shown in <figref idref="f0016">FIG. 16</figref>, a muffler element 151, such as a DPF 17, is accommodated in the casing of the exhaust gas treatment apparatus 4.

0079The sizes of the engine body 1 and the exhaust gas treatment apparatus 4 are compared below. Assuming that, in case of the engine body 1 having 3800 cc, for example, the front and rear width L1 of the engine body 1 is 600 mm, the front and rear width L2 of the engine body 1 including a flywheel housing 51 is 738 mm, and the height H of the engine body 1 is 826 mm as shown in <figref idref="f0015">FIG. 15</figref>, the diameter R1 of the exhaust gas treatment apparatus 4 is 300 mm as shown in <figref idref="f0015">FIG. 15</figref>, the diameter R2 of the connection flanges 9 and 11 of the exhaust gas treatment apparatus 4 is 340 mm and the left and right width W of the exhaust gas treatment apparatus 4 is 560 mm as shown in <figref idref="f0016">FIG. 16</figref>, and the diameter R1 of the exhaust gas treatment apparatus 4 is about 1/3 of the height H of the engine body 1.

0080As shown in <figref idref="f0014">FIG. 14</figref>, a single support bracket 12 which is long in the forward and backward directions is disposed at the lower side of the middle part of the exhaust gas treatment apparatus 4 in the left and right directions. The exhaust gas treatment apparatus 4 is placed on the back side of the support bracket 12. The front and back parts of the support bracket 12 are detachably coupled to respective support stays 2 and 3 attached to the front and back sides of the engine body 1. The support stays 2 and 3 are attached to respective connection flanges 8 and 9 on the left and right sides of a DPF accommodation casing 5 placed in a central portion through respective installation members 155 and 156 disposed on the left and right sides and configured to have a '⊐' shape.

0081As shown in <figref idref="f0019">FIG. 19</figref>, the installation members 155 and 156 on the left and right sides include respective lower wall portions 155a and 156a of a horizontal shape, respective fixed wall portions 155b and 156b raised from the external ends of the lower wall portions 155a and 156a in the left and right directions, and respective installation wall portions 155c and 156c raised from the internal ends of the lower plate units 155a and 156a in the left and right directions.

0082As shown in <figref idref="f0019">FIG. 19</figref>, the fixed wall portions 155b and 156b of the installation members 155 and 156 on the left and right sides are assembled with the respective lower portions of the connection flanges 8 and 9 on the left and side of the DPF accommodation casing unit 5 placed in a central portion and then fastened by bracket installation fastening members 25 and 25. The installation wall portions 155c and 156c of the pair of installation members 155 and 156 have the support unit 12d of the support bracket 12 inserted therebetween on both sides left and right, and they are then fastened by the bracket installation fastening members 25. Accordingly, the support bracket 12 is attached to the connection flanges 8 and 9 on the left and right sides of the DPF accommodation casing unit 5 placed in a central portion through the installation members 155 and 156. The bracket installation fastening members 25 and 25 which fix the installation members 155 and 156 on the left and right sides to the connection flanges 8 and 9 on the left and right sides also serve as the flange connection fastening members 43 and 50. As shown in <figref idref="f0015">FIGS. 15</figref> and <figref idref="f0018">18</figref>, the locked units 10a and 11a, such as the connection flanges 10 and 11 locked by the flange connection fastening members 43 and 50, are spaced apart from each other at equal angles of 60° and placed at 6 places in the circumferential direction of the connection flanges 10 and 11.

0083As shown in <figref idref="f0019">FIG. 19</figref>, the lower plate units 155a and 156a, the fixed wall portions 155b and 156b, and the installation wall portions 155c and 156c of the installation members 155 and 156 on the left and right sides are coupled by connection plates 159 and 160. As shown in <figref idref="f0014">FIG. 14</figref>, the front support stay 2 installed in the front part of the engine body 1 has a placement unit 2b of a horizontal form. The placement unit 2b couples the upper end portions of a pair of support legs 163 and 164 and a pair of support legs 163 and 164 on the left and right sides. The lower portion of the support leg 163 on the left side is fixed to the left face of a cylinder head 19 of the front part of the engine body 1, and the lower portion of the support leg 164 on the right side is fixed to the upper right portion of the front part of the engine body 1. As shown in <figref idref="f0015">FIG. 15</figref>, in a support stay 3 on the back side, the lower portion of a stay installation unit 3a having an upper and lower long belt form is fixed to the back side of the engine body 1. A placement unit 3b forwardly curved in an 'L' form is formed at the top of the stay installation unit 3a.

0084According to the second embodiment, in case where the exhaust gas treatment apparatus 4 is installed within the bonnet 107 as shown in <figref idref="f0015">FIG. 15</figref>, the support bracket 12 long in the forward and backward directions is previously attached to the lower side of a middle portion of the exhaust gas treatment apparatus 4 in the left and right directions, the support stays 2 and 3 on the front and back sides are previously installed in the front and rear portions of the engine body 1, the front part of the support bracket 12 is placed in the placement unit 2b of the front stay 2, the back part of the support bracket 12 is placed on the placement unit 3b of the rear support stay 3, and the front and back parts of the support bracket 12 are fixed to the placement units 2b and 3b using bracket installation fastening members 14, such as bolts. Accordingly, although the exhaust gas treatment apparatus 4 has a large size and heavy weight, the exhaust gas treatment apparatus 4 can be simply installed in the engine body 1.

0085Furthermore, after the exhaust gas treatment apparatus 4 is installed, the front and back parts of the support bracket 12 supporting the weight of the exhaust gas treatment apparatus 4 are detachably coupled to the support stays 2 and 3 on the front and back sides which are installed in the front and back parts of the engine body 1. Accordingly, although the exhaust gas treatment apparatus 4 has a large size and heavy weight, it can sufficiently stand self weight and a vibration of the tractor vehicle body 1, the front and rear distance from the front part of the exhaust gas treatment apparatus 4 to the longitudinal pipe 149 can be reduced, and thus space above the engine body 1 can be efficiently used.102, and the deformation and damage of the support bracket 12 can be prevented. Furthermore, the length direction of the exhaust gas treatment apparatus 4 is disposed in the left and right directions. Accordingly, more empty space can be secured as compared with a case in which the length direction of the exhaust gas treatment apparatus 4 is disposed in the forward and backward directions. Furthermore, since the longitudinal pipe 149 is disposed on the side of the back part of the engine body 1, the front and rear distance from the front part of the exhaust gas treatment apparatus 4 to the longitudinal pipe 149 can be reduced, and thus space above the engine body 1 can be efficiently used.

0086Furthermore, as shown in <figref idref="f0019">FIG.19</figref>, the connection flanges 8 and 9 are configured to flange-couple the casing units 6 and 7 on the left and right sides and formed in the DPF accommodation casing unit 5 placed in a central portion, and the support bracket 12 is installed on both sides of the connection flanges 8 and 9 on the left and right sides of the DPF casing unit 5 placed in a central portion through the installation members 155 and 156. Accordingly, the support bracket 12 and the connection flanges 8 and 9 on the left and right sides can be easily coupled. Furthermore, the support bracket 12 can be robustly fixed and installed in the middle portion of the exhaust gas treatment apparatus 4 using the connection flanges 8 and 9 of the casing unit 5. Accordingly, the deformation and damage of the support bracket 12 can be prevented.

0087Furthermore, as shown in <figref idref="f0015">FIG. 15</figref>, the bonnet 107 is formed with the ceiling unit 107a downwardly inclined, and the exhaust gas treatment apparatus 4 is disposed left and right at a position having the greatest gap between the engine body 1 and the back part of the bonnet 107. Accordingly, the exhaust gas treatment apparatus 4 of a large size can be disposed in small space, and the weight of the tractor 102 itself can be well balanced on the front and back sides. Other features or functions of the second embodiment may be the same as those of the first embodiment.

0088<figref idref="f0021 f0022 f0023 f0024 f0025 f0026 f0027">FIGS. 21 to 27</figref> show a third embodiment. A pair of support brackets 12a and 12b on the left and right sides are disposed in response to respective connection flanges 8 and 9 on the left and right sides of a DPF casing unit 5 placed in a central portion. The front parts of the pair of support brackets 12a and 12b are detachably coupled to the upper portion of a front support stay 2. The back parts of the pair of support brackets 12a and 12b are detachably coupled to the upper portion of the rear support stay 3.

0089As shown in <figref idref="f0026">FIG. 26</figref>, the support unit 12d of the support bracket 12a on the left side is assembled with the lower portion of the connection flange 8 on the left side of the DPF casing unit 5 placed in a central portion and fastened by bracket installation fastening members 25 and 25. The support unit 12d of the support bracket 12b on the right side is assembled with the lower portion of the connection flange 9 on the right side of the DPF casing unit 5 placed in a central portion and fastened by bracket installation fastening members 25 and 25. The bracket installation fastening members 25 and 25 also serve as flange connection fastening members 43 and 50 and attach the support brackets 12a and 12b on the left and right sides to the connection flanges 8 and 9 on the left and right sides. As shown in <figref idref="f0022">FIGS. 22</figref> and <figref idref="f0025">25</figref>, locked units 10a and 11a, such as connection flanges 10 and 11 fastened by respective flange connection fastening members 43 and 50, are spaced apart from each other at equal angles of 45° and placed at 8 places in the circumferential direction of the connection flanges 10 and 11. The back side of the front support stay 2 is reinforced by a reinforcement plate 76. The rear support stay 3 has an installation unit 3a and a placement unit 3b coupled by a reinforcement plate 80.

0090According to the third embodiment, as in the second embodiment, although the exhaust gas treatment apparatus 4 has a large size and heavy weight, the exhaust gas treatment apparatus 4 can stand its weight and a vibration of the tractor vehicle 102. Furthermore, the pair of support brackets 12a and 12b installed in the exhaust gas treatment apparatus 4 can detachably coupled to the support stays 2 and 3 on the front and back sides of the front and back parts of the engine body 1. Accordingly, the exhaust gas treatment apparatus 4 can be easily installed in the engine body 1.

0091Moreover, in the third embodiment, the pair of support brackets 12a and 12b on the left and right sides are disposed in response to the respective connection flanges 8 and 9 on the left and right sides of the DPF casing unit 5 placed in a central portion. The front parts of the pair of support brackets 12a and 12b on the left and right sides are detachably coupled to the upper portion of the front support stay 2. The back parts of the pair of support brackets 12a and 12b on the left and right sides are detachably coupled to the upper portion of the rear support stay 3, and the pair of support brackets 12a and 12b on the left and right sides are used. Accordingly, the exhaust gas treatment apparatus 4 can be easily and robustly installed through the pair of support brackets 12a and 12b on the left and right sides by using the connection flanges 8 and 9 on the left and right sides of the DPF casing unit 5 placed in a central portion.

0092<figref idref="f0027">FIG. 27</figref> shows a modification example of the support bracket. The support unit 12d of support brackets 12a and 12b is divided into a support member body 81 and a fixing plate body 82 which is fixed to connection flanges 8 and 9 on the left and right sides of a DPF casing unit 5 placed in a central portion. The support member body 81 and the fixing plate body 82 are detachably fastened by a fixture, such as bolts. In the modification example, although the support member body 81 and the fixing plate body 82 are detached, the exhaust gas treatment apparatus 4 can be detached from the engine body 1. Accordingly, periodic inspection can be easily performed on the exhaust gas treatment apparatus 4. Other features or functions of the third embodiment may be the same as those of the first and second embodiments.

0093In the second embodiment of <figref idref="f0014 f0015 f0016 f0017 f0018 f0019 f0020">FIGS. 14 to 20</figref>, a single support bracket 12 is installed in the connection flanges 8 and 9 on the left and right sides of the DPF casing unit 5, placed in a central portion, of the exhaust gas treatment apparatus 4 through the pair of installation members 155 and 156. Furthermore, in the third embodiment of <figref idref="f0021 f0022 f0023 f0024 f0025 f0026">FIGS. 21 to 26</figref>, the support brackets 12a and 12b on the left and right sides are installed in the respective connection flanges 8 and 9 on the left and right sides of the casing unit 5 placed in a central portion of the exhaust gas treatment apparatus 4. However, the support brackets 12, 12a, and 12b may be installed only in one of the connection flanges 8 and 9 on the left and right sides of the casing unit 5 placed in a central portion of the exhaust gas treatment apparatus 4.

0094The construction of a fourth embodiment shown in <figref idref="f0028 f0029 f0030">FIGS. 28 to 30</figref> is described below. As shown in <figref idref="f0028">FIGS. 28</figref> and <figref idref="f0029">29</figref>, an exhaust gas treatment apparatus 4 is placed at a long posture in the left and right directions, and the DPF accommodation casing unit 5 of the exhaust gas treatment apparatus 4 is disposed on the upper back side of a flywheel housing 51 immediately after a head cover 20 attached to the upper portion of a cylinder head 19.

0095A pair of support stays 71 and 72 on the left and right sides are installed in the rear portion of the engine body 1. The support protrusions 32 and 33 of the connection flange 10 of an exhaust inlet-side casing unit 6 and of the connection flange 11 of an exhaust outlet-side casing unit 7 are installed in the pair of left and right support stays 71 and 72 using flange installation locking units 73 without using support brackets on the left and right sides. The flange installation locking units 73 are inserted into position adjustment holes, like the position adjustment holes 26 of the bracket installation fastening members 25, and configured to pass therethrough. Furthermore, the positions of the flange installation locking units 73 can be adjusted in the upper and lower directions and the forward and backward directions. In addition, like the flange-fit concave units 38a and 38b, flange fitting units 74 are installed in a pair of stays on the left and right sides. Lower edge portions, such as the connection flange 11, are fitted into the fitting units 74. In the fourth embodiment, like the first embodiment, the DPF 17 is accommodated in the exhaust gas treatment apparatus 4, and the engine cooling fan 21 is disposed in the front part of the engine body 1. Other features or functions of the fourth embodiment may be the same as those of the first embodiment.

0096In the claims, 'forward and backward' or 'front and rear' relate (as is usual) to a lengthwise direction corresponding to the direction in which a centre line of a crankshaft extends, and 'left and right' relate to a width direction transverse to the lengthwise direction.