Pipe connection device for connecting two pipe ends, especially two pipe ends in an exhaust line of a combustion engine

0001The invention relates to a pipe connection arrangement for connecting two pipe ends, in particular two arranged in an exhaust line of an internal combustion engine pipe ends, according to the preamble of claim 1. Furthermore, the invention relates to an exhaust system of an internal combustion engine of a vehicle, in particular a commercial vehicle, with a pipe connection assembly and a commercial vehicle with a such exhaust system.

0002In a pipe connection arrangement in an exhaust gas stream of an internal combustion engine, in particular the operational thermal pipe expansion is to be taken into account by which the two pipe ends are displaced towards one another at the end face. In addition to such an axial displacement, angular errors and axial offsets can also occur in the connection arrangement. In order to compensate for such positional tolerances, it is generally known to arrange the mutually associated pipe ends in an axially aligned and spaced manner and to tightly connect them by a connecting pipe device which is deformable and / or displaceable during relative movements of the pipe ends. For such compensating connection tube devices, corrugated tube compensators or elastomer compensators connected to both tube ends, for example, are provided. in particular silicone rubber compensators, or plug connections are well known. Such tightly connecting connecting pipe devices are usually less resistant to the high thermal loads as they occur in an exhaust system of an internal combustion engine than the pipes used, so that weak points can form with the possibility of leaks.

0003From the <patcit id="pcit0001" dnum="EP2273175B1"><text>EP 2 273 175 B1</text></patcit> an arrangement for connecting two pipe ends is known, wherein the two pipe ends are spaced with an axial gap and connected by means of a connecting pipe piece in a plug connection in such a way that the connecting pipe piece is respectively inserted tube end inside with an axial end portion tightly fitting in both Rohrendbereiche. This creates a thermally expandable and position tolerances compensating sealing connection for connecting pipe ends in an engine exhaust system. The connecting pipe section should consist of a precipitation-hardenable alloy. In addition, the outer surfaces of the connecting pipe piece should have a wear-resistant coating. Such a wear-resistant galvanized coating is also made of<patcit id="pcit0002" dnum="EP2096194A2"><text>EP 2 096 194 A2</text></patcit> known.

0004A similar structure with a wear-resistant coating on the outer surface of the connecting pipe is also made of <patcit id="pcit0003" dnum="EP2154408B1"><text>EP 2 154 408 B1</text></patcit> known.

0005From the <patcit id="pcit0004" dnum="DE102010045986A1"><text>DE 10 2010 045 986 A1</text></patcit> are also known such internal connecting tube configurations, but at the same time also outer connecting tubes, in which the tube ends abut against the inner walls of the connecting tube in a wide, flat abutment connection. The pipe ends can each have an annular circumferential raised ball portion on its outer peripheral surface, wherein the associated inner wall portions of the outer connecting tube have a corresponding spherical shape, so that a flat contact connection is created.

0006An external connection pipe is also from the, a compliant pipe connection facing <patcit id="pcit0005" dnum="DE1491170A"><text>DE 1 49 11 70 A</text></patcit> known, in which the cylindrical tube ends are provided with so-called spherical surfaces, which lie flat against a corresponding spherical shaped inner surface of the connecting tube.

0007A disadvantage of all these known pipe joint arrangements is that these are sometimes very expensive to manufacture and assembly and also position tolerances can not be compensated to the desired extent.

0008In the <patcit id="pcit0006" dnum="EP1191269A2"><text>EP 1 191 269 A2</text></patcit> discloses a pipe joint of two inserted into a sleeve pipe ends, in which between the inner shell of the sleeve and the outer shell of at least one pipe end a spherical shape is provided. In a specific embodiment, this spherical shape is arranged here on the circumference of the outer shell of at least one pipe end.

0009Object of the present invention is to provide a pipe joint assembly for connecting pipe ends of two pipes, in particular two arranged in an exhaust line of an internal combustion engine pipes, which is both manufacturing technology and assembly technology relatively simple and which is also able to position tolerances in a wide Compensate the circumference functionally reliable.

0010This object is achieved with the features of the independent claims. Advantageous embodiments are the subject of the dependent claims.

0011According to claim 1, a pipe connection arrangement for connecting pipe ends of two tubes, in particular two arranged in an exhaust line of an internal combustion engine tubes is provided, which has two axially aligned and / or spaced-apart tube ends, each having on its outer peripheral surface an annular circumferential, raised ball portion wherein the two pipe ends are received with their raised ball portions in a pipe around the pipe ends on the outside in an overlapping portion connecting tube such that the ball portion respectively radially circumferentially in a ball portion abutment portion on an inner wall of the connecting pipe. It is also planned that the raised ball portions in the ball portion abutment areas each rest along a circular line and thus in a circular contact with the inner wall of the connecting tube, and in particular tight fit. This is the case when the diameter of the ball sections is made equal to the inner diameter of the connecting pipe in the associated ball section abutment area.

0012Such a merely circular arrangement of the tubular end-side raised spherical sections on the inner wall of the connecting tube allows for a formation of a sufficiently tight connection between the connecting pipe and pipe end and also allows the compensation of positional tolerances, such as angular errors, axial offsets and / or length offsets, in a particularly large extent because it allows the circular system while maintaining the tight contact connection on the inner wall of the connecting pipe particularly well to deflect the pipe ends with a relatively large tilt angle. In addition, such a circular system, unlike a flat system connection, less susceptible to overdetermination resulting from, for example, tolerance-induced manufacturing inaccuracies and / or thermally induced inaccuracies during operation. Furthermore, the pipe connection according to the invention can be produced with external connection pipe and there only in a circular system inlaid ball sections of the pipe ends on montagetechnisch fast and easy way.

0013The connecting pipe itself can in principle have any desired shape, for example, be formed as a corrugated tube, as long as it is ensured that the inner wall of the connecting tube for the circular contact of the raised ball sections on the inner wall of the connecting tube at least in the spherical section investment area flat and circular cylindrical, with a , the line-shaped adjacent ball-section abutment area substantially corresponding inner wall inner diameter is formed. It is understood that the spherical section outer diameter defined by the circular arrangement on the inner wall of the connecting tube in this case corresponds to the associated inner wall inner diameter such that a sufficiently tight contact connection of the raised spherical sections takes place on the inner wall,

0014For example, this may be done for a press fit oversize by a corresponding coating and / or training of mutually associated contact surfaces of a wear-resistant material. This means that the inner wall of the connecting tube can be made of a wear-resistant material or can be coated with it, at least in the ball-section abutment region and / or the outer surface of the spherical section.

0015According to a further particularly preferred embodiment, the inner wall of the connecting tube is continuous flat and circular cylindrical with a constant same inner diameter. Such inner wall geometry can be produced easily and inexpensively.

0016In order to facilitate the insertion of the tubular end-side ball sections can be further formed at the two opposite end sides of the connecting tube in each case a chamfer, in particular a rounded chamfer.

0017Particularly simple and inexpensive to manufacture is a connecting tube, which is formed by a, a connecting sleeve forming cylinder tube with the same inner and outer diameter throughout.

0018According to the invention, a catalytic substrate is at least partially introduced into the interior of the connecting tube and / or provided in the interior of the connecting tube, for example on an inner wall of the connecting tube, at least partially a catalytic coating to effect an exhaust gas purification and / or contribute to the exhaust gas purification. Furthermore, according to the invention, the arrangement of the catalytic substrate and / or the catalytic coating takes place here in a section lying between the two ball-section contact areas. The connecting tube or the interior (for example, the inner wall) of the connecting pipe thus contributes in a particularly preferred dual function at the same time to the exhaust gas purification, whereby the efficiency of the exhaust gas purification can be increased or increased overall.

0019Furthermore, the connecting tube may also be provided with a thermally insulating coating on its outside at least in regions. This helps to prevent inadmissible heat losses and thus surface temperatures, so that it can then come in the region of the connecting pipe to no undesirable condensation. The coating can in principle be of any desired design, for example of an insulating material, but can also be formed, for example, by a separate component with which the connecting tube is encased. Alternatively, however, the thermally insulating coating can also be formed by a firmly adhering coating, for example by a thermally stable elastomer coating, for example a silicone coating.

0020With regard to the compensation of positional tolerances, in particular the compensation of angular errors, axial offsets and / or length offsets, it has proved to be particularly advantageous if at least one of the two raised ball sections, preferably both raised ball sections, the pipe connection assembly according to the invention, seen in longitudinal section, respectively form a subsequent on the flat outside of the tube end circular segment, wherein for the circular segment at least one of the following conditions applies:<ol id="ol0001" ol-style=""><li>a) the center angle measured from the center of the circle of the circle segment is 90 ° to 120 °, preferably 100 ° to 110 °,</li><li>b) the ratio of the segment height to the segment length determined by the chord is 1: 3 to 1: 5, preferably 1: 3.5 to 1: 4.2</li><li>c) the ratio of the segment height to the radius is 1: 2 to 1: 3, preferably 1: 2.4 to 1: 2.7</li><li>d) the ratio of the radius to the circular segment length determined by the chord is 1: 1.25 to 1: 1.75, preferably 1: 1.4 to 1: 1.6, most preferably about 1: 1.15.</li></ol>

0021The abovementioned ratios are to be understood such that the second-mentioned value corresponds in each case to a multiple of the first-mentioned value, that is to say, for example, for the ratio b) of segment height to chord, a ratio of 1: 3 specifically means that the chord of the circle has three times the value of the segment height , The same applies analogously to the ratios in the points c) and d) as well as for any ratios mentioned below.

0022As already stated, the investigations by the inventor have shown that at least one of the conditions mentioned must be fulfilled in order to provide a structure by means of which positional tolerances and high thermal loads can be reliably compensated within large ranges, but with particularly good results be achieved on the compensation of positional tolerances in a wide range, if all of the above conditions a) to d) are fulfilled collectively.

0023The individual conditions mentioned cause the raised ball sections can function reliably and tightly in the desired circular contact with the inner wall of the connecting pipe even with large axial offsets or angular errors. This can also be further increased by providing, according to a further particularly preferred embodiment, that the distance of, relative to the longitudinal section through the pipe joint assembly, contact point of the raised ball portion in a basic position of the pipe joint, of the ball portion associated with the leading edge of the inner wall of the connecting tube, at most 2.5 times the segment height, preferably at most 2.0 times the segment height, and at least 1.0 times the segment height, preferably at least 1.5 times the segment height amounts.

0024Furthermore, it has proved to be advantageous overall with respect to the tube dimensioning if the radius of the circular segment to the outer diameter of the tube end in the region outside the raised spherical segment 1: 1.1 to 1: 1.4, preferably 1: 1.2 to 1: 1,3, is. This also ensures that the pipe end provided with the raised ball portion can be displaced within relatively large angular ranges relative to the connecting pipe.

0025Particularly advantageous in terms of manufacturing technology, the two raised spherical sections are identically formed at the tube ends with geometrically identical dimensions, so that, for example, the connecting tube can be produced particularly simply and inexpensively, since it can receive both the one and the other tube end from both sides. This reduces the variety of parts and helps to reduce manufacturing costs and storage costs.

0026At least one of the raised ball sections, preferably both raised ball sections of the pipe connection arrangement, is of the same material and / or formed integrally with the associated pipe end, for example by appropriate machining, for example by means of turning or milling, or by forming. Alternatively, at least one of the raised ball sections, preferably both ball sections, but also be formed by a separate component which is positively and / or non-positively and / or positively connected with its associated pipe end. The latter embodiment has the advantage that the pipe ends can be made essentially as identical parts and can be provided individually with the corresponding desired ball sections.

0027According to a first particularly preferred embodiment, the pipe end may have an internal thread, in which the raised ball portion with a, a corresponding external thread having a pin portion, which adjoins the ball portion, can be screwed. Alternatively, the pipe end may have an external thread onto which the raised ball portion can be screwed with a pin portion having a corresponding internal thread, which adjoins the ball portion. In connection with such a screwable solution, a construction is advantageous in which the ball section has at least one tool attachment. This tool approach can for example be formed by a plurality of outside groove-like engagement recesses as a tool approach.

0028As an alternative to the screwable solution just described, however, the ball portion may also have an inner recess and be pressed onto the pipe end as an externally pressed component. Alternatively, the ball portion but also have a pin portion, by means of which the ball portion is pressed as an internally compressed component in the pipe end. It is understood that in all the aforementioned embodiments with a journal portion of the ball portion then protrudes freely according to the pipe end to insert or insert this into the connecting pipe.

0029For a particularly strong connection of the pipe end with the ball portion may be provided to connect them at least partially cohesively. Welding and / or soldering is particularly suitable as cohesive connection.

0030The advantages that result with the exhaust system according to the invention or with the utility vehicle according to the invention correspond identically to those already explained in detail in connection with the pipe connection arrangement according to the invention.

0031The pipe ends to be connected here are preferably formed by adjacent exhaust manifold sections, but may generally also be formed by an exhaust manifold section and a pipe section associated with the cylinder head or formed by any pipes through which hot media flows, for example in the region of interfaces to exhaust gas recirculation lines and / or from the exhaust gas turbocharger lines to mention other uses of the pipe connection assembly according to the invention in conjunction with the preferred use thereof in an exhaust line of an internal combustion engine.

0032The invention will be explained in more detail with reference to a drawing.

0033Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>schematically and by way of example an external perspective view of a pipe connection arrangement according to the invention,</dd><dt>Fig. 2</dt><dd>the pipe connection arrangement according to <figref idref="f0001">Fig. 1</figref> in a side view,</dd><dt>Fig. 3</dt><dd>a section through the pipe connection assembly according to <figref idref="f0002">Fig. 2</figref> along the line AA in a basic position, in which the two pipe ends held in the connecting pipe are shown in a basic or initial position and are exactly in alignment,</dd><dt>Fig. 4</dt><dd>one of the <figref idref="f0002">Fig. 3</figref> corresponding representation in which the pipe ends are no longer exactly in alignment, but with respect to the basic position of the <figref idref="f0002">Fig. 3</figref> have an axial offset or angle error to be compensated,</dd><dt>Fig. 5</dt><dd>schematically an alternative embodiment with a, a journal portion having ball portion, wherein the journal portion has an external thread, via which it is screwed into an internal thread of the associated pipe end, and</dd><dt>Fig. 6</dt><dd>one to <figref idref="f0004">Fig. 5</figref> alternative embodiment, wherein the journal portion of the ball portion has an internal thread which is bolted to a corresponding external thread of the associated pipe end.</dd></dl>

0034In the <figref idref="f0001">Fig. 1</figref> is schematically and exemplified an external perspective view of a pipe joint assembly 1 according to the invention shown, for example, two in an exhaust pipe not shown further of an internal combustion engine also not shown pipe ends 2, 3, for example, adjacent exhaust manifold sections of an exhaust manifold not shown here, are interconnected ,

0035As can be seen in particular from the synopsis of a side view of the <figref idref="f0001">Fig. 1</figref> displayed <figref idref="f0002">Fig. 2</figref> and from the sectional view along the line AA of <figref idref="f0002">Fig. 2</figref> displayed <figref idref="f0002">Fig. 3</figref> it can be seen, the pipe joint assembly 1 here two with respect to their central axes 4, 5 mutually aligned, axially aligned and spaced from each other by means of an axial gap 6 pipe ends 2, 3, which each have an annular circumferential, raised ball portion 7 on one of its outer peripheral surface.

0036The two pipe ends 2, 3, in the <figref idref="f0002">Fig. 3</figref> are shown in their basic position without axial and angular offset and thus aligned exactly aligned with each other, are taken with their raised ball sections 7 in a pipe tube 2, 3 on the outside in an overlap section encompassing connecting tube 8.

0037This connecting tube 8 is here exemplified as a cylinder tube with a continuous same inner and outer diameter and thus has a flat and circular cylindrical with a constant same inner diameter formed inner wall 9, at which the two raised ball portions 7 of the pipe ends 2, 3 in the <figref idref="f0001 f0002">Fig. 1 to 3</figref> shown plugged in each case along a circular line 10, as shown only schematically and dashed in the <figref idref="f0001">Fig. 1</figref> and in the <figref idref="f0002">FIGS. 2 and 3</figref> (there in a two-dimensional projection) is shown only very schematically.

0038With this circular system a relatively large area is provided, in the axial and angular offsets of the two pipe ends functionally reliable with a still dense contact connection of the ball sections 7 on the inner wall 9 of the connecting pipe 8 in a large area or in a large extent can be included, which is schematically in the <figref idref="f0003">Fig. 4</figref> is indicated. Concretely, the two raised ball sections 7 are seen in longitudinal section (<figref idref="f0002">Fig. 3</figref>) are preferably designed such that they form a circle segment 12 adjoining the flat outer side 11 of the pipe ends 2, 3, for which at least one, preferably all, of the following conditions apply or apply:<ol id="ol0002" ol-style=""><li>a) the center angle α measured from the center of the circle M of the circle segment 12 is 90 ° to 120 °, preferably 100 ° to 110 °,</li><li>b) the ratio of the segment height h to the circle segment length I determined by the circular chord is 1: 3 to 1: 5, preferably 1: 3.5 to 1: 4.2,</li><li>c) the ratio of the segment height h to the radius r is 1: 2 to 1: 3, preferably 1: 2.4 to 1: 2.7,</li><li>d) the ratio of the radius r to the circle segment length I determined by the chord is 1: 1.25 to 1: 1.75, preferably 1: 1.4 to 1: 1.6, and most preferably about 1: 1, 5,</li><li>e) the distance of - related to in the <figref idref="f0002">Fig. 3</figref> shown longitudinal point through the pipe joint assembly 1 - contact point A (which is part of the circle 10) of the raised ball portion 7 of the ball portion associated with the insertion edge 13 of the inner wall 9 of the connecting tube is a maximum of 2.5 times the segment height h, preferably a maximum of 2, 0 times the segment height h, and at least 1.0 times the segment height h, preferably at least 1.5 times the segment height h,</li><li>f) the ratio of the radius r of the circle segment to the outer diameter D._a the pipe ends 2, 3 in the region outside the raised sphere section is 1: 1.1 to 1: 1.4, preferably 1: 1.2 to 1: 1.3.</li></ol>

0039As this is the schematic representation of <figref idref="f0002">Fig. 3</figref> can be seen, but there is shown for clarity, only at the right end of the connecting tube 8, at least one, preferably at both opposite end sides of the connecting tube 8 each have a chamfer 14, in particular a, as shown, rounded bevel 14 may be provided, which the introduction of the tubular end-side ball sections 7 in the connecting tube 8 facilitates, in particular when the outer diameter of the ball portion 7 has an excess over the correspondingly associated inner diameter of the inner wall 9 of the connecting tube 8.

0040Like this from the <figref idref="f0002">Fig. 3</figref> only schematically shown and there is only dashed lines, the connecting pipe 8 may be provided on its outside at least partially with a thermally insulating coating 15. This can be formed for example by an insulating or insulating material.

0041Further, here in an inner wall section 17 lying between the two ball-section abutment regions 16, a coating 18 causing an exhaust gas purification and / or contributing to the exhaust gas purification is provided, in particular a catalytically active coating 18. This is shown exaggerated here only for reasons of clarity.

0042Furthermore, both the inner wall 9 and the surface of the ball sections 7 can be provided with a wear-resistant coating or be formed there, for example by alloying, with such a wear-resistant coating.

0043As in the embodiment of <figref idref="f0001 f0002 f0003">Fig. 1 to 4</figref> shown, the two raised ball portions 7 may be formed identical to the pipe ends 2, 3 with substantially the same geometric dimensions and thereby form identical parts. For this purpose, the respective raised ball portion 7 may be formed, for example, the same material and / or in one piece with the associated pipe end, which can be done for example by a machining or by forming.

0044Alternatively, however, as in the <figref idref="f0004">Fig. 5</figref> and <figref idref="f0005">6</figref> is shown in each case in connection with the left there ball portion 7, at least one of the raised ball portions 7 may be formed by a separate component, which then with its associated pipe end 2 form and / or non-positively and / or positively connected.

0045Like in the <figref idref="f0004">Fig. 5</figref> By way of example, the pipe end 2 may have, for example, an internal thread 19, into which the raised ball section 7 can be screwed with a pin section 21 having a corresponding external thread 20, which adjoins the ball section 7. It is understood that both the pin portion 21 and the ball portion 7 here each have or form an inner recess 22, which form the extension of the hollow pipe end 2.

0046Alternatively to this embodiment of <figref idref="f0004">Fig. 5</figref> may also be provided in an analogous embodiment, that the pin portion 21 is pressed into the pipe end.

0047In the <figref idref="f0005">Fig. 6</figref> is one to <figref idref="f0004">Fig. 5</figref> shown alternative embodiment in which the pipe end has an external thread 23, on which the raised ball portion 7 with a, a corresponding internal thread 24 having pin portion 21 which adjoins the ball portion 7, can be screwed.

0048At the ball portion 7, specifically here at the constituent part of the ball portion 7 forming pin portion 21 may then, for example in the form of at least one groove-like engagement recess, a tool attachment 25 may be provided for screwing the ball portion with the associated pipe end. The tool attachment 25 may additionally or alternatively also be formed directly on the ball portion 7 itself, that is, it may not be formed on the journal portion 21 of the ball portion 7.

0049Alternatively to this embodiment of <figref idref="f0005">Fig. 6</figref> can also be provided in an analog embodiment, that the hollow ball portion 7 is pressed onto the pipe end.

0050Furthermore, the ball section 7 produced by a separate component can alternatively or additionally also be connected to the associated pipe end 2 by means of a material connection, for example by welding and / or soldering.

Bezuaszeichenliste

0051<dl id="dl0002" compact="compact"><dt>1</dt><dd>Pipe assembly</dd><dt>2</dt><dd>pipe end</dd><dt>3</dt><dd>pipe end</dd><dt>4</dt><dd>central axis</dd><dt>5</dt><dd>central axis</dd><dt>6</dt><dd>axial gap</dd><dt>7</dt><dd>ball section</dd><dt>8th</dt><dd>connecting pipe</dd><dt>9</dt><dd>inner wall</dd><dt>10</dt><dd>circle line</dd><dt>11</dt><dd>even outside</dd><dt>12</dt><dd>circular segment</dd><dt>13</dt><dd>lead-in</dd><dt>14</dt><dd>chamfer</dd><dt>15</dt><dd>thermally insulating coating</dd><dt>16</dt><dd>Spherical segment-bearing regions</dd><dt>17</dt><dd>Inner wall section</dd><dt>18</dt><dd>catalytically active coating</dd><dt>19</dt><dd>inner thread</dd><dt>20</dt><dd>external thread</dd><dt>21</dt><dd>journal section</dd><dt>22</dt><dd>inner recess</dd><dt>23</dt><dd>external thread</dd><dt>24</dt><dd>inner thread</dd><dt>25</dt><dd>tool attachment</dd></dl>