Exhaust system for a motor vehicle as well as motor vehicle

The invention relates to an exhaust system for an a vehicle body and an internal combustion engine exhibiting motor vehicle, with a connectable to the combustion engine exhaust, comprising at least one deformable line member, at least one arranged downstream of said tube and at least one downstream of said pipe member arranged muffler, and with retention means for holding the exhaust on the vehicle body.

The exhaust system is provided for example for a passenger car, the vehicle body has a frame and a vehicle floor. However, the exhaust system may possibly also for another vehicle - used - for example, a truck or bus. The internal combustion engine may consist of a gasoline or diesel engine.

When using a motor vehicle are the engine vibration, ie vibration of the motor housing is generated and transmitted to the latter via the mechanical connection of this with the exhaust. Further, the engine exhaust gas leads to a pulsating, which may also excite vibration of the exhaust. In exhaust vibrations with different vibration modes can thereby arise. The vibrations cause the exhaust periodically over time and relatively rapidly changing accelerations of the vibrating parts of the exhaust. Furthermore, driving over holes and other irregularities, the cornering and acceleration and braking of the vehicle accelerations of the exhaust cause. These accelerations caused by driving normally change much slower than the acceleration caused by the vibration. The exhaust is further heated by the exhaust gas during operation of the engine, wherein the exhaust gas temperature decreases away from the engine along the flow path. The heating effect due to the thermal expansion of the rigid parts of the exhaust pipe a temporary extension of this. In known passenger cars, the lengths of the exhaust pipes, for example, about 4 m and caused by temperature changes changes in length, for example, be approximately 0.5% to 1%, ie, about 2 cm to 4 cm.

From DE 30 26 730 A, DE 31 37 746 A and numerous cars have exhaust systems with exhaust and holding means are known that have the exhaust holding the vehicle body rubber rings. When a force is applied to a so-held part of the exhaust, put the rubber rings of a deflection of the exhaust from its rest position initially received only a very small resistance. Only when the deflections of the exhaust parts reach certain limits, the resistance generated by the rubber rings is skyrocketing. These limits are, in practice, usually about 1 cm to 2 cm, or possibly even more. Held by the holding means parts can move almost freely within the area bounded by the above-mentioned limits areas therefore. From US 5,323,989 A and US 4,060,143 A exhaust systems are known in which the holding means also comprise elastic elements and enable at least in different directions a fairly free, limited movement of the exhaust. From some of the cited publications and from practice, it is also known to equip the exhaust between the engine and the (first) silencer with a deformable pipe member having, for example, a bellows or a rubber ring.

The known deformable pipe members serve primarily as decoupling elements to decouple the downstream of them arranged mufflers and other exhaust parts vibrationally from the engine. Since the known exhausts and in particular downstream of the deformable pipe elements parts can move fairly freely within certain limits, the transverse oscillations are generated with large amplitudes in the exhausts despite the deformable pipe members frequently. This is especially the case when the exhausts have resonances in the field of fundamental vibrations generated by the engine. The vibrations and other forces acting on the exhaust accelerations and forces cause a heavy pressure on the exhaust pipes belonging, silencer casings and deformable pipe members. The pipes of the exhaust therefore have a minimum of 1.5 mm wall thickness amount end passenger cars. The silencers usually have housing with coats and end walls, also be the wall thicknesses of passenger cars more than 1 mm and often at least 1.5 mm. The exhaust pipes and mufflers case of trucks usually have even greater wall thicknesses. The exhaust of the known exhaust systems is therefore difficult. In addition, a weight enlarging heat shield between the or each silencer and the vehicle floor must be arranged in known exhaust systems often. The high weight of the known exhaust systems requires the production of which a lot of material, for example, much relatively expensive, stainless steel, and increases especially fuel consumption when driving. despite the large wall thicknesses addition occur rather frequently breaks the exhaust. Since the silencers of the known exhausts normally be transverse to the general longitudinal direction of the exhaust from their Central and / or rest position in different transverse directions until at least 1 cm and often deflected to 2 cm or more, they claim, in addition to the they occupy space also space for their transverse movements. This often has the disadvantage means that the silencers can not be sized so large as would be desirable for a good sound damping.

The invention has for its object to avoid the disadvantages of the known exhaust systems and in particular to provide an exhaust system that has a low weight in relation to the flow rate of the to be derived through the exhaust system the exhaust gas and with respect to the length and the characteristic cross-sectional dimensions of the exhaust pipe while is permanent.

This object is inventively achieved by an exhaust system having the features of claim 1.

The invention further relates to a motor vehicle according to the invention comprises the features of claim 23rd

Advantageous embodiments of the exhaust system will be apparent from the dependent claims.

According to the invention, at least a large part of the exhaust are designed with very thin walls. As a result, the weight of an inventive exhaust system against the weight of known exhaust systems can be reduced considerably with similar passage cross-sectional areas, cross-sectional dimensions and lengths of the various exhaust parts. The weight of the downstream of the first in the exhaust gas flow direction elastically deformable pipe member arranged exhaust part can be reduced by about or more than 50%, for example, with otherwise approximately the same rating.

In an advantageous development of the subject matter in the case of the or each layer of sound-absorbing silencer, a heat-insulating and insulating material between the shell of the housing and a hollow interior is available. Furthermore, it is preferably also present between each end wall and the hollow interior of the or each muffler sound-absorbing and heat-insulating insulation material. If the exhaust has a downstream of the first elastically deformable pipe member, and / or arranged below the vehicle floor catalyst, the housing may also include analog arranged sound-absorbing and heat-insulating insulation materials. These insulation materials are preferably made of mineral fibers, for example basalt wool and / or other rock wool and / or may be glass wool. Such a material has a high temperature resistance and a relatively low density. Such thermal insulation of the or at least one or each arranged under the vehicle floor housing allows to keep the heat transfer to the vehicle floor in spite of thin-walled housing low and to waive the application of a metallic heat shield on the vehicle floor and thereby also reduce weight.

According to an advantageous development of the subject invention, the holding means adapted to the or at least the (first) to keep along the exhaust in the exhaust gas flow direction of the first elastically deformable line member following housing such on the vehicle body, that this or any case by the from the engine and vibrations generated by the otherwise acting on the exhaust accelerations and forces at least in all approximately perpendicular to the vehicle longitudinal direction at most little is deflected. By such a relatively rigid mounting at least resonances of transverse modes of vibration of the (first) downstream of the (first) elastically deformable line member arranged housing and practically the whole downstream of said pipe member arranged exhaust part can be largely suppressed. Accordingly, the oscillation amplitudes and other caused by driving movements of said exhaust part are greatly reduced. This allows, in turn, thin-walled and easily form the downstream of the (first) elastically deformable line member arranged pipes and boxes and yet to achieve a high lifetime of the exhaust pipe. The reduction of the transverse deflection further allows the diameter or other cross-sectional dimensions of a silencer body to enlarge, without that this encounters due to vibration or other accelerations against the vehicle floor or other parts of the vehicle body. Such an enlargement of a silencer body, in turn, allows an improvement in the sound attenuation.

The retaining means preferably include for the or each housing, the at least downstream of the (first) elastically deformable pipe member is arranged, at least one holder, which is connected directly to the housing. It is then not necessary, the pipes to keep themselves directly to the vehicle body. Since a muffler and / or catalyst with a housing usually a larger mass and a greater weight per unit length than a pipe, contribute directly to the or each housing engaging holding means to a stable mounting and a low mechanical stress of the various parts of the exhaust in ,

The subject invention is subsequently explained with reference to the drawings, exemplary embodiments. In the drawings<ul><li>FIG. 1 is a schematic, partly in view, partly in section signed motor vehicle having an exhaust system,</li><li>FIGS. 2 a signed partly in view, partly in longitudinal section elastically deformable line member of the exhaust system,</li><li>FIGS. 3 a longitudinal section through the first muffler of the exhaust system,</li><li>FIG. 4 shows a cross section through the first muffler,</li><li>FIG. 5 shows a longitudinal section through the second silencer of the exhaust system,</li><li>FIG. 6 shows a cross section through the second silencer,</li><li>FIG. 7 is a section through the vehicle floor and a view of the first muffler, and a serving for fastening the holder,</li><li>Fig. 8 is a section through a holder taken along the line VIII-VIII of Fig. 7 on an enlarged scale,</li><li>FIG. 9 is a section through the vehicle floor and a view of the second muffler</li><li>FIG. 10 is an axial section through a variant of a connecting member of a holder,</li><li>FIG. 11 is an axial section through yet another connection member of a holder, </li><li>Fig. 12 a to FIG. 7 analog representation with another holder,</li><li>Fig. 13 is a plan view of parts of the holder according to FIG. 12,</li><li>Figs. 14 a to FIG. 7 analog representation with another holder,</li><li>FIG. 15 is a plan view of parts of the visible in Fig. 14 holder</li><li>Figs. 16 a to FIG. 7 analog representation with another holder,</li><li>Figs. 17 a to FIG. 7 analog representation with yet another holder,</li><li>FIG. 18 is a similar to FIG. 1 showing a motor vehicle with a different exhaust system and</li><li>FIG. 19 contains a longitudinal section through a housing, the catalyst means and forms a part of a muffler.</li></ul>

The schematically drawn in FIG. 1 motor vehicle 1 consists of a passenger car and has a vehicle body 2. This has a self-supporting body 3, a vehicle floor 4 and a frame 5. The vehicle body 2 holds an internal combustion engine 6, front wheels 7, 8 rear wheels and a whole designated by 11 exhaust system. The internal combustion engine 6 has a vibration-damping on the frame 5 attached motor housing 6a with a plurality of exhaust ports, each of which is associated with a cylinder of the engine. The exhaust system 11 has as a main component an exhaust 12. This has, in the direction of flow of the exhaust gas in series, a inlet and collecting apparatus 13, a catalyst 14, a short pipe 15, a first elastically deformable pipe member 16, a long, straight tube 17, a second elastically deformable line member 18, a first silencer 19, a short pipe 20, a third elastically deformable line member 21, a longer, bent pipe 22, a second silencer 23 and a discharge pipe opening into the environment 24. The internal combustion engine 6 is located at the forward end of the motor vehicle 1. The exhaust 12 generally extends approximately parallel to the longitudinal and driving direction of the vehicle 1 from the engine 5 to the rear of the vehicle and is for the most part below the vehicle floor 4. The exhaust system 11 includes further retaining means 27. These have four holders 28, 29, 30, 31, 19 and 23 which, namely connecting the two muffler in the vicinity of its ends to a rigid part of the vehicle body 2 to the vehicle floor. 4

The inlet and collecting apparatus 13 has an exhaust manifold having for each exhaust outlet of the engine a bent inlet pipe, whose input is connected with one of the exhaust ports of the engine housing. The device 13 further includes the outputs of the intake pipes connecting bus connection means to one another and a common for all inlet pipes output 13a. The inlet and collecting apparatus 13 is, for example, completely rigid, but may possibly at least an elastically deformable coupling element having a bellows or the like which connects one of the intake pipes to the common output 13a. However, the common output 13 to be connected through the collector connection means rigid with at least one of the inlet pipes and the motor housing 6a. The catalyst 14 has a rigid housing having an input, which is rigidly connected to the common output 13a of the inlet and collecting apparatus. 13 The pipes 15, 17, 20, 22, 24 are rigid. The inlet and collecting apparatus 13, the housing of the catalytic converter 14 and the tubes 15, 17, 20, 22 and 24 are made of metallic materials such as stainless steel. The apparatus 13, the housing of the catalytic converter 14 and the tube 15 are tightly joined together, namely welded.

The three elastically deformable pipe members 16, 18, 21 are shown only schematically in Fig. 1 and have, for example, a metallic, namely consisting of stainless steel, flexible, bendable, extendable and retractable bellows having its ends tightly and securely to the respective preceding are connected and subsequent exhaust parts, welded for example, directly or indirectly. The pipe members 16, 18, 21 can still have additional parts. The second elastically deformable line member 18 is formed, for example, according to FIG. 2 and has as main components a bellows 33, an inside of this fluid control inner sleeve 34, a the bellows in cross-section enclosing, serving as a protective sheath outer sleeve 35 and a connecting piece 36. The line element 18 also has a cross-sectionally approximately U-shaped ring 37 outside with an open to the outside groove and in this held, deformable damping element 38. this is formed by a multi-layer, to form a ring with a solid cross section shaped wire mesh and projects out of the channel of the ring 37 out. The said parts of the pipe element 18 are made of metallic materials such as stainless steel. The bellows 33 has a cylindrical end portion at both ends and is rigidly and tightly connected to the ends of the two sleeves 34, 35, namely welded to his in the Fig. 2 left ends located end. These ends of the corrugated bellows 33 and the sleeves together form the first terminal 39 - namely, the input -. The line element 18. The located is in the 2 right exploiting dividend end of the corrugated bellows firmly and tightly connected to the other end portion of the sleeve 36 and the ring 37, namely welded. The other, narrower end portion of the sleeve 36 forms the second terminal 40 - namely, the output - of the line element. The inner sleeve 34 protrudes into the other end portion of the stub 36th The cylindrical main portion of the inner sleeve 34 is separated by annular gaps from the inner wave crests of the corrugated bellows 33 and the inner surface of the connecting piece 36th The outer sleeve 35 has has a cylindrical center portion, which is separated by a gap from the outer wave crests of the corrugated bellows and some holes. Which are going through FIG. 2 to the right end portion of the outer sleeve 35 is bent inwards and surrounds a portion of the damping member 38. The pipe member 18 is generally rotationally symmetric to an axis 41.

The first and third elastically deformable line member 16 and 21 are for example the same or similar configuration to the second elastically deformable pipe member 18. The pipe members 16, 18, 21, however, can also be of different dimensions and / or designed and modified in various ways. The inner sleeve 34 may for example be omitted for the enlargement of the flexibility of the corrugated bellows. Further, the outer sleeve 35, the ring 37 and the damping element 37 may, for example, in particular the first conduit member 16 or for all line elements 16, 18, 21 formed by a flexible, extensible and retractable, from wires or metal strips sheath are replaced.

The first elastically deformable line member 16 is used in particular as a vibration damper and decoupling element and to the that are available with respect to the exhaust gas flow direction downstream of the line element 16 parts of the exhaust 12 decouple vibrationally from the engine and as far as possible to prevent the operation of the engine vibration generated or vibrations are transmitted from the motor housing to the downstream ends located by the line element 16 exhaust parts. The second and third line element 18 or 21 is also still used for vibration decoupling moderate. The first and the second lead member 16 and 18 are also to decouple the downstream of them located ends exhaust parts also with respect to other, that is not caused by vibration movements, in particular tilting movements, from the motor housing.

The Bellows of three pipe members 16, 18, 21 and in particular the second and third line element 18 and 21 may also change under elastic deformations their lengths and in particular starting shortened from their resting states along their axes. When separately drawn in Fig. 2 second lead member 18 then, the two sleeves 34, 35 for example, starting shifted from subscribed, occupied with resting motor idle state to the right against the terminal 40. The parallel to the axis 41 of the pipe element 18 measured distance between the two ports 39, 40, ie the length of the pipe element can preferably at least 5 mm and even changed a little more, for example to about 10 mm or, ie starting downsized from an idle state and / or be enlarged. The first and the third line element 16 or 21 can have their length preferably also change at least 5 mm and, for example, to about 10 mm or more, ie starting decrease and / or increase of an idle state.

The two pipe members 16 and 18 can offset caused by temperature changes changes in length upstream of the first silencer 19 located the pipes 15 and 17 and other solid exhaust parts. The two pipe members 16, 18 can thereby offset along their axes and / or to the longitudinal direction of the motor vehicle and / or to the axis of the first silencer 19 parallel length and other dimensional changes that approximately up to at least 5 mm or at least 10 mm or even up amount to or more than 20 mm. The third line member 21 can compensate for changes in length located between the two silencers 19, 23 tubes 20, 22nd The third duct element 21 may in to compensate changes in length and / or other dimensional changes to its axis and / or to the longitudinal direction of the motor vehicle and / or to the axes of the first muffler 19 and / or the second muffler parallel direction to at least 5 mm and, for example, to at least 10 mm.

The separately in Figures 3 and 4 apparent, first muffler 19 has an elongated sealed housing 45 which is generally rotationally symmetrical about a straight axis 46th The wall of the housing 45 has a substantially cylindrical casing 47 and two side facing away, leak tight and firmly connected to the casing end walls 48 and 49 on. The two end walls are for example at least partially conical or curved to stiffen the housing. The housing 45 includes two gas permeable partition walls 50, 51, each of which is located near one of the end walls 48, 49 and consists of a substantially planar annular disc. The two partitions 50, 51 are perforated at least in places, and have to achieve good rigidity preferably also at least one compact, non-perforated area. The silencer 19 has two to the axis 46 coaxial tubes 53 and 54. The tube 53 passes through which the left end of the muffler exploiting dividend end wall 48 and intermediate wall 50. The other pipe 54 penetrates the end wall 49 and the partition wall 51. The pipes 53, 54 are rigidly and tightly connected to the end wall 48 and 49th The partitions 50, 51 are fixed and more or less tightly connected to the shell 47 and / or to the tube 53 and 54, and have, for example, by spot welding connections on the jacket fastened flanges. The outer end of the tube 53 forms the input port of the muffler 19 and is connected to the conduit member 18th The outer end of the tube 54 forms the output port of the muffler 19 and is connected via the pipe 20 to the conduit member 21st Each tube 53, 54 has in the vicinity of its inner end a gas permeable perforated portion 53a or 54a. The tube 54 has 54a between its perforated portion and its serving as an output terminal end still serving as a choke constriction 54b. The inner ends of the two pipes 53, 54 are separated in the axial direction by a gap from each other. The inner end of the tube 53 is closed by squeezing more or less dense or may be open. The inner end of the tube 54 is squeezed together and more or less tightly. The housing 45 includes between the two intermediate walls 50 and 51, a generally cylindrical inner sheath 55. This consists of two sleeve-shaped inner shell parts, each of which at one end to one of the intermediate walls 50, 51 is secured. The other, the intermediate walls facing away from end portions of the two inner casing parts enclosing each other with at most small game and are parallel to the axis 46 relative to each other. The two-piece inner shell 55 is in the greatest part of its length gas-permeable and perforated, however near his left located ends end a compact, ie hole-free portion 55a, which surrounds the axis 46, extends approximately over the length portion of the perforated pipe section 53a and for example, at both ends slightly project beyond the latter. The exploiting dividend in within the housing 45 of the pipe section 54 is longer than half the length of the housing and is supported at its inner end with a few rod-shaped supports 56 on the inner casing 55th The housing 45, the partitions 50, 51, the two tubes 53, 54, the inner casing 55 and the supports 56 are made of metallic materials such as stainless steel. The between the end wall 48 and the intermediate wall 50 as well as between the end wall 49 and the intermediate wall 51 present, the pipe 53 and 54 respectively enclosing the annular gaps are filled with a layer of thermally insulating or filling and sound-absorbing material 57 and 58th The annular cross-sectional space which is located between the two partitions 50, 51 and between the shell 47 of the casing and the inner casing 55 is also filled with a layer of heat-insulating and sound-absorbing material 59th The materials 57, 58, 59 consist, for example, from fibers of the above in the introduction contrast, the the inner casing 55 enclosed in cross-section, between the two intermediate walls 50, 51 existing inside. 60 - apart from the pipes 53, 54 and pillars - hollow and empty.

The second, separately drawn in Figures 5 and 6 silencer 23 has a housing 65 with a straight axis 66. The housing has a cylindrical casing 67 and two end walls 68, 69. contains The housing two disc-shaped, at least in places, gas-permeable, perforated partitions 70 , 71. the muffler 23 has two pipes 73 and 74. the tube 73 penetrates the end wall 68 and the intermediate wall 70. the tube 74 penetrates the end wall 69 as well as the intermediate wall 71. the housing 65 of the second muffler 23 is shorter than the housing 45 of the first muffler 19, but has a larger diameter than the housing 45. the tubes 73, 74 are parallel to the axis 66, but arranged on different sides of this.

Further, the two tubes 73, 74 to exploiting dividend side by side in the same longitudinal section of the housing 65 portions. The outer end of the tube 73 forms the input terminal of the second muffler 23 and is connected to the pipe 22nd The tube 73 is squeezed at its that are available in the housing 65 and the end more or less sealed or open and 73a a gas-permeable, perforated section in the vicinity of this end. The tube 74 is open at its inner end and has no perforated section. The outer end of the tube 74 forms the output port of the second muffler 23 and is connected to the outlet pipe 24 and / or forms it. The second silencer 23 has an inner shell 75, which is like the first silencer of two interlocking protruding, mutually displaceable inner shell parts. The inner shell 75 is mostly gas-permeable and perforated but has a compact 75a, hole-free portion. This extends over a somewhat longer longitudinal region than the perforated portion 73a of the pipe 73, however, enclosing the axis 66 is not complete, but occupies only amid a school near the tube 73 circumference area of ​​the inner shell.

The two existing between the end walls 68, 69 and one of the gas permeable partition walls 70 and 71, gaps include a material 77 and 78 between the housing casing 67 and the inner shell 75 existing space containing a material 79. The materials 77, 78 , 79 are in turn heat-insulating and sound-absorbing and consist of mineral fibers. Between the two intermediate walls 70 and 71 present, surrounded by the inner sheath 75 in cross-section interior space 80 is apart from the tubes 73, 74 is hollow and free. Unless stated otherwise above written, the second silencer 23 is formed similarly to the first muffler 19th

. The schematically drawn in Figure 1 holder 28, 29, 30, 31 for securing the two silencers 19 and 23 may - be the same differently designed and dimensioned or all - depending on the design of the vehicle bottom 3. Both for fastening the first silencer 19 serving holder 28, 29 are, for example, formed identically or similarly, are along the silencer axis 46 at a distance from each other and are in the vicinity of both ends of the silencer 19, namely at its intermediate walls 50 or 51 attached to its shell. The holder 28 is formed as shown in FIGS 7 and. 8 In the figures 7 and 8, a segment of the vehicle floor 4 can be seen. This is, for example, generally more or less flat but has an upwardly projecting bulge. This defines a downwards open channel, which is often referred to as a tunnel and in which there is at least a part of the exhaust pipe 12 and in particular at least one cross-sectional area of ​​the end view in shown in Fig. 7, the first silencer 19th

The holder 28 has a directly on the housing 45 of the first muffler 19 engages retainer 85, and the latter two to the vehicle floor 4 linking connecting members 87 on. The retaining member 85 is made of a metallic material such as stainless steel. The retaining member 85 is rigid, arranged longitudinally and at right angles to the silencer 19 and consists essentially of a U-profile bar with a web 85a and two limbs 85b. The U-profile bar is reinforced at the ends by end members which are integrally welded with the legs and also either welded to the web or by using this. The middle section of the retaining member 85 is bent parallel to the jacket 47 of the silencer body 45, is the outer, the top located ends surface of the web 85a on the lower side of the silencer body 45 on the casing 47 and is for example, by some point welds or other weld connections on the casing 47 mounted. Each connecting member 87 is at least partly elastically deformable and consists for example of a one-piece rubber-elastic body made of synthetic and / or natural rubber. Each connecting member is substantially rotationally symmetrical about an axis and has 87a comprises a generally cylindrical, but in the middle area in the axial section slightly indented main portion. This has over its entire axial dimension a full cross-section and thus contains no free cavities or gaps or holes. The main portion 87a has flat at its two ends, annular support and / or end faces and is connected in the middle region of each end to an axial direction of this projecting away approximately mushroom-shaped extension, the fastening and / or connecting means 87b or 87c forms. The two holders 28 and 29 at the same associated connecting members 87 are provided along the retaining element 85 of the relevant holder, mutually offset and arranged in the vicinity of the ends of the retaining member. Each connecting member is located on the flat support and / or end surfaces of its main portion 87a on the upper surface of the web 85a of the holding member or on a portion of the lower surface of the vehicle floor. 4 The mushroom-shaped fastening and / or connecting means 87b, 87c are in the assembly of the exhaust under a temporary elastic deformation through holes in the web 85a or vehicle bottom 4 inserted through and grab this one, so that the heads of the fastening and / or connecting means to web 85a and the vehicle floor 4 engage behind. The connecting members 87 connecting the holding members 85 and at this welded first muffler 19 then releasably connected to the vehicle floor. 4

The first muffler 19 is thus held by four connecting members 87 to the vehicle floor 4 of the vehicle body 2 in the assembled state. The four connecting members 87 together form a 4-point suspension. The centers of the four first muffler holding connecting members 87 define in a vertical projection onto a horizontal plane, on which the motor vehicle 1 is a quadrangle such as a rectangle. In this case, on each side of a plane passing through the axis 46 vertical plane two connecting members present.

The second muffler 23 is arranged, for example in the vicinity of the rear end of the vehicle 1 behind the rear axle under a more or less planar portion of the vehicle floor. 4 The front for holding the second muffler on the vehicle floor 4 serving holder 30 is particularly evident in FIG. 9 can be seen and has a rigid, elongate, metallic holding member 95 and two at least partially elastically deformable connecting members 97. The retaining member 95 is similar to the holding members 85 formed, however, lies with the central portion of its web on the upper side of the muffler 23 on the jacket 67 of the housing 65 at. The connecting members 97 of the holder 30 are the same or similar design as the connecting members 87, however, protrude from above into the groove of the holding member 95 in and lie on the inner surface of the web on. The rear holder 31 of the second silencer, for example, the same or similar design to the front holder 30. Unless stated otherwise above written, the holders 30, 31 are the same or similar design and attached to the muffler and the vehicle floor as the holder 28, 29th

The downstream of the catalyst 14 exploiting dividend portion of the exhaust 12 is generally approximately parallel to the longitudinal and main driving direction of the vehicle 1. The axes of the elastically deformable pipe members 16, 18 and 21 are at rest straight and for example, approximately parallel to the longitudinal and main driving direction of motor vehicle. The axes of the mufflers are for example at least approximately parallel to the longitudinal and driving direction of the vehicle.

The catalyst 14 and the pipe 15 are connected by the inlet and collecting apparatus 13 rigidly to the motor housing 6a. The rubber-elastic connecting members 87, 97 of the holder 28, 29, 30, 31 allow because of their elastic deformability small deflections of the silencer housings 45 and 65 from the rest positions of these housings. However, consisting of compact rubber bodies connecting members generate this counteracting restoring forces, which continue to grow with increasing deflection within a certain range, monotonous and, for example, more or less linearly to the deflection at very small, arbitrary direction deflections. The connecting members 87, 97 thus allow certain but only relatively small movements of the silencer body. The connecting members also provide a vibration damping connection of the muffler housing to the vehicle body. The connecting members 87, 97 of the holder 28, 29, 30, 31 are preferably formed such that each silencer casings 45, 65 in the assembled exhaust pipe through a one or each housing 45, 65 acting, constant, steady acceleration of 10 m / s² and, for example, also 20 m / s² or even 50 m / s² or a constant, steady force of 100 N in any direction of the vehicle body than 5 mm and preferably at most 2 mm from the middle and / or rest position of the respective housing is deflected. The housings 45, 65 are then in the assembled exhaust particular also by accelerations or forces which have the aforementioned variables as well as any desired direction and, for example approximately parallel to the longitudinal and main traveling direction of the vehicle and approximately parallel to the axes 46, 66 of the housing 45 , 65 are or example, any of the longitudinal direction of the vehicle and to the axes 46, 66 have approximately perpendicular direction, at most 5 mm and preferably not more than 2 mm from a central and / or rest position deflected or moved. The holder may for example be designed such that the deflections of the two silencer housings also lie in the said accelerations or forces within the said regions when the housings 45, 65 from the remaining exhaust parts and are separated from each other.

As mentioned in the introduction, the exhaust is heated by the supplied him by the engine exhaust. The exhaust manifold is heated by the exhaust gas, for example to a temperature of at least 1000 ° C. The front tubes 15, 17 are heated, for example to temperatures in the range of 500 ° C to 800 ° C and the rear tubes 20, 22, 24 to temperatures of about 200 ° C to 500 ° C. The heated portions of the exhaust expand temporarily, so that in particular the pipes 15, 17, 20, 22 are longer. The pipes and boxes for example consist of steel having a linear expansion coefficient of about 1.2^, 10^-5/ ° C. The pipes 15, 17 are then, for example, about 0.6% to 1%, and the tubes 20, 22, 24 extended by approximately 0.2% to 0.6%.

Present in the silencer tubes 53, 54, 73, 74 are also heated by the exhaust gas and also extended. Since these tubes attached at one end to the housing of the relevant silencer and at the other end are free, they can be extended freely, without creating tensions. The exhaust gas also heats the inner sheaths 55 and 75 of the silencer. Since each inner casing consists of two parts, having one end fixed and the other end is movable, the length changes of the inner shell parts also generate no tension.

The existing in the housings of the silencers, consist of fibers 57, 58, 59, 77, 78, 79 insulate the sheaths 47, 67 thermally from the exhaust gas, so that these coats at most relatively slightly to temperatures of, for example, approximately through the exhaust 100 ° C are heated to 300 ° C. Further, it is thereby avoided that the rubber body of the holder being damaged by heating. Since the shells are 47, 67 heated by the hot exhaust gas at most slightly, the high temperature of the exhaust gas also causes at most small extensions of the jackets 47, 67. As a result, the total extension of the exhaust is reduced compared to a conventional exhaust having housings without heat insulation. The extention of the housing can be absorbed by deformation of the elastic connecting members of the holders. Due to the heat insulation is at least largely avoided that the hot exhaust gas generated stresses in the shells, although they are connected approximately immovably connected to the vehicle floor at both ends.

The containing the materials 57, 58, 59, 77, 78, 79 spaces of the silencer are through the perforation holes of the partitions 50, 51, 70, 71 and inner sheaths 55, 75 through with the hollow, free, flowed through by exhaust gas interiors 60 and 80 connected. Therefore, the existing of fibers, sound absorbing materials also result in a substantial improvement of the sound absorption.

The thermally induced changes in length of the pipes 15, 16, 20 and the changes in length of the silencer housings are compensated at least for the most part by the elastically deformable pipe members 16, 18, 21st therefore act most minimal, caused by changes in temperature stresses and forces on the pipes and mufflers. The silencers to be moved by the thermally induced changes in length of the pipes and the consequent and not by the deformable pipe members 16, 18, 21 compensated residual forces at most little, for example at most 2 mm, contrary to the recovery forces generated by the deformable connecting members 87, 97, wherein such any possible shifts of the muffler are approximately parallel to the axes.

As described in the introduction, can be excited by the vibrations of the motor housing and the pulsating exhaust vibrations of the various exhaust parts and are also caused by the driving force acting on the exhaust parts accelerations with the use of the motor vehicle. The mufflers have from the downstream of the first elastically deformable pipe member 16 arranged exhaust parts the largest mass per unit length. The somewhat mobile, resilient and vibration-damping, but rather rigid connections of the silencer to the vehicle body 2 prevent strong vibrational resonances, vibrations of large amplitudes and other larger movements of the silencer. The pipes 15, 17, 20, 22 and in particular the two silencers 19, 23 are represented by the vibrations and the most excited by the pulsating exhaust vibrations in all directions generated by the internal combustion engine during normal operation at most 5 mm, preferably at most 2 mm and typically at most 1 mm or even deflected only at most 0.5 mm from its middle layers, which they assume after reaching the operating temperatures due to the thermal dimensional changes. The caused during normal operation of the motor vehicle by an uneven road curves, acceleration and braking and accelerations acting on the exhaust caused deflections from said middle layers be in all directions also at most 2 mm and typically at most 0.5 mm. Furthermore, be the entire exhaust-displacements caused by temperature changes, vibrations and other accelerations, starting from the area occupied with the motor in cold condition rest positions during normal driving in all directions at most 5 mm and preferably at most 2 mm.

The downstream of the catalyst 14 and in particular of the first elastically deformable pipe member 16 arranged tubes do not need large caused by the vibration or driving forces and accelerations to take. The pipes 15, 17, 20, 22 therefore need essentially only their own weight and possibly also partly the weight of the elastically deformable pipe members 16, 18 to carry 21st It is therefore not necessary, the pipes 15, 17, 20, 22, 24 to hold through directly to themselves attacking holder on the vehicle body. The pipes 15, 17, 20, 22, 24 and the tubes present in the mufflers 53, 54, 73, 74 can also be made relatively thin-walled and have wall thicknesses, at least substantially at most 1 mm, preferably at most 0.8 mm and for example, be about 0.5 mm. It should be noted that the tubes which may overlap possibly at the junctions with them connected parts, so that may be the result exhaust sections with slightly thicker wall thicknesses there. These optionally present, thicker sections are then relatively short and much shorter than the whole exhaust. The walls of the pipes of the exhaust manifold of the inlet and collecting apparatus 13 may possibly also slightly thinner than conventional, non-inventive exhaust systems are dimensioned and possibly similar thicknesses as arranged after the catalyst 14 tubes. The shells 47, 67, end walls 48, 49, 68, 69 and partitions 50, 51, 70, 71 and inner sheaths 55, 75 of the muffler need also to have only small wall thicknesses. These wall thicknesses are at least at the largest parts of these walls coats and more than 1 mm, preferably at most 0.8 mm and for instance approximately 0.5 mm.

The between the jackets 47, 67 and the inner mantles 55 and 75 of the muffler existing consist of fibers 59 and 79 constitute amount layers whose measured in the radial direction in the cross-sectional layer thicknesses of at least 10 mm and, for example, about 20 mm. The measured in the axial direction dimensions of the existing between an end wall and an intermediate wall materials 57, 58, 77, 79 be at least 10 mm, preferably at least 20 mm and for example 25 mm to 80 mm.

The visible in Fig. 10 connecting member 101 is composed of a composite body and is substantially rotationally symmetrical to an axis. The connecting member 101 has a substantially cylindrical consisting of natural and / or synthetic rubber elastic body 102 is provided at each of its two ends with a recess. Each recess includes a flat plate 103 having a central hole and the head of a fastening and / or connecting means 104 forming the hole of the plate penetrating bolt with an axially extending away from the rubber body 102 threaded portion. The two plates 103 and the fixing and / or connecting means 104 consist of a metallic material such as steel and are joined by casting and / or vulcanization of the rubber and / or by gluing or the like firmly and inextricably linked to the rubber body. The rubber body has between the filled by the plate 103 and fastening and / or connecting means 104 recesses have a full cross section. The platelets 103 and these enclosing edges of the rubber body 102 together form flat support and / or end surfaces of the connecting member one hundred and first

The 11 visible in Fig. Connecting member 111 is similar to the connecting member 101 made ​​of a composite body with a rubber body 112, two plates 113 and fixing and / or connecting means 114, 115. The a fastening and / or connecting means 114 are as in the connection member 101 helically. The other fastening and / or connecting means 115 are connected by a protruding from the rubber body forth in the hole of the plate threaded book se or mother formed whose threaded hole is on the deeper in the rubber body located ends end of the fastener is closed by a disc.

One can some or all in the 7 to 9 apparent connecting members 87, 97 of the holder 28, 29, 30, replace 31 by connecting members 101 and / or 111th The or each linking member 111 can then be connected to the vehicle floor or ungekehrt for example, by the connecting means 114 having a holding member and by the fastening means 115th The vehicle floor 4 can then accordingly be provided with welded threaded bushes or threaded bolts or the like. Furthermore you can combine features of the connecting members 87, 97, 101, 111 with each other and provide for example, connecting members which have at one end a mushroom-shaped appendage of rubber and at the other end a screw or threaded bushing or both ends of the rubber body Gewindebbuchsen. Furthermore, connecting elements can be provided which have at least at one end a formed as a sheet metal screw threaded part or are formed for riveting or welding on. In addition, the rubber body can have a more upright shaped end portion having at least one end for engagement with a key or even in cross-section substantially entirely in the form of a regular polygon, such as a 6- or 8-gon.

Between the two support and / or end faces measured, axial dimension of the main portion 87a of the completely made of rubber connecting member 87 and the rubber body 102, 112 is for example about 50% to 150% of the maximum diameter of the respective rubber body. The maximum diameter is also in an exhaust system for a passenger car, preferably about 15 mm to 50 mm. Said axial dimension can then be about 10 mm to 50 mm.

The attachment to the first silencer 19 serving holder 28, 29 may be replaced by holders, one of which is marked in Fig. 12 and partially in FIG. 13 and denoted by 121. The holder 121 has as main components a directly on the housing 45 of the silencer 19 engaging holding member 122, a fixed on the vehicle floor 4 a support element 123 and two the latter connecting with the retaining member 122 connecting member 125 on. are The retaining member and the support member are made at least substantially of a metallic material such as stainless steel, while the connecting members 125 are made at least in large part made of elastomeric material and the same or similar to one of the previously described connecting members 87, 97, 101, 111 are formed , The retaining member 122 has the mantle 47 of the muffler 19 surrounds Bride 126 and a arranged at the ends of closure 127 and is releasably attached to the muffler housing 45th The support member 123 consists for example of a multiply bent flat profile bar or U-profile bar. The support member 123 is arranged below the muffler 19 and attached on opposite sides of the latter with attachment means 129 releasably or non-releasably on the vehicle floor third The attachment means 129 comprise for example sheet metal screws or normal metal screws which are passed through holes of the supporting member 123 is screwed into the vehicle base 4 and / or welded-on that threaded bushes. However, the screws could be replaced by latching elements or rivets or other fastening means.

Each or at least one of the holders 28 to 31 can for example also according to the in the Fig. 14 and in part in the FIG. 15 apparent holder be formed 131st In the Fig. 14 are similar as in Figs. 7 and 12, a segment of the vehicle floor 4 and the muffler 19 drawn. The holder 131 has an attached silencer on retainer 132, a fixed to the vehicle floor support member 133 and two connecting members 135th The retaining member 132 again has a Bride 136 with a shutter 137, and in addition two angled tabs 138, whose one ends are fixed to the Bride and projecting from this. The support member 133 consists of a straight U-section bar, whose ends are fastened with fastening means 135 on the vehicle floor. 4 The a rubber body having connecting members 135 are at their one, upper end of one of the tabs 138 and secured at its other end on the support organ 133rd

In the depicted in FIG. 16 variant of the vehicle floor 4 which is less high than in the Fig upwardly projecting bulge. 7, so that a cross-sectional area of ​​the silencer 19 protrudes downward from the bulge limited by the tunnel. The drawn in Fig. 16 bracket 141 has a retainer 142 and two connecting members 145. The retaining member 142 has a muffler 19 surrounds Bride 146 and a multiply bent flat or U-profile bar 147. The middle section of the profiled bar 147 is bulged in accordance with the arrangement of the muffler down and attached to both sides of the bulge at the Bride. The connecting members 145 are disposed in the vicinity of the ends of the profile bar 142 and connect it to the vehicle floor. 4

The 17 drawn in FIG. Excerpt from the vehicle floor 4 has a groove and / or an asymmetric, downwardly open tunnel, which the muffler 19 is in the or at least partly. The visible in Fig. 17, holder 151 has a holding member 152 having a enclosing the muffler and a Bride attached thereto, multiply angled and / or bent rod whose ends are connected through connecting members 155 to the vehicle bottom 5.

Unless stated otherwise written, the apparent in Figures 12 to 17 holders are similarly formed as that described with reference to FIGS 7 and 8, holder 83 and have connecting elements, which are one of the connecting members 87, 97, 101, 111 the same or similar ,

The visible in Fig. 18 motor vehicle 201 again consists of a passenger car, having a vehicle body 202 having a body 203, a vehicle floor 204 and a frame 205, an internal combustion engine 206 with a motor housing 206a and an exhaust system 211 with an exhaust 212. This includes - starting the engine - along the exhaust gas flow path in series, a inlet and collecting apparatus 213 to an exhaust manifold and a common output 213a, a first elastically deformable line member 216, a rigid tube 217, a second elastically deformable conduit element 218, a catalyst 219, a tube 220, a third elastically deformable line member 221, a first muffler 222, a tube 223, a fourth elastically deformable line member 224, a pipe 225, a second muffler 226 and an outlet 227 on. The catalyst 219 is therefore placed downstream of the elastically deformable pipe elements 216, 218 and is located below the vehicle floor 204. The catalyst 219 is elongated and has a roughly parallel to the longitudinal direction of the vehicle axis, and a housing 235 having a shell 237, and two end walls 238 , 239. the jacket has 237 in cross-section, for example the shape of a flattened oval or a circle. The end walls 238, 239 are, for example, at least partially conical and / or curved and inclined relative to the axis. The housing 235 contains catalyst means for the catalytic purification of the exhaust gas. The mantle and the end walls of the housing of the catalytic converter 219 can have similar small wall thicknesses, as was earlier indicated for the silencer of the exhaust housing 12th The catalyst housing 235 can include sound-absorbing and heat-insulating fiber materials which are arranged in the same way as the first described exhaust silencers of the 12 possible.

The exhaust system 211 has still retaining means 241, which hold the housing of the catalytic converter and the two silencers on the vehicle floor 204th The holding means comprise two holders 243 for holding the catalyst body 235, and two holders 244, 245 for holding the housing of the muffler 222 and 226 on. The holder 243, 244, 245 are the same or similar design as the holder previously described and in particular have each two connecting members, which consist entirely or partially of a rubber body. Unless stated otherwise above written, the exhaust system can be 211 configured the same or similar to the exhaust in Annex 11.

The 19 visible in Fig. Device 251 forms a combined catalyst-silencer and has an elongated housing 255 having an axis 256, a jacket 257 and two end walls 258, 259 on. The housing 255 includes, for example, similar to the silencer body of the exhaust pipe 12, two gas-permeable partition walls 260, 261, a gas permeable inner casing 265, as well as heat-insulating and sound-absorbing fiber materials 267, 268, 269. The jacket 257, end walls 258, 259, the intermediate walls 260, 261 and the inner surface 265 may be similar and similar wall thicknesses as in the mufflers of the exhaust 12th

The partition walls and the inner shell define a hollow interior 270. The housing 255 is provided at its end walls having an inlet 271 and an outlet 272 and contains catalyst means 275. These subdivide the interior 270 in a first, inner interior region 277 and a second, outer interior region 278. the inlet 271 opens at the partition wall 260 in the first interior region 277. the outlet 272 is formed by a tube which projects into the second interior portion 278 and formed, for example similar to the 3 visible in FIG. tube 54 of the silencer 19th the catalyst means 275 serve for the catalytic cleaning of the exhaust gas and have a multiplicity of passages, which connect the first to the second interior region. The catalyst means 275 can, for example, have two V-shaped arranged catalytic body and can be configured similarly as it 5593645 A and the corresponding EP 0676535 A is known from the US. The content of these publications is hereby incorporated by reference, as far as there are no contradictions. The housing 255 is held by two holders 291 on the vehicle floor. The holder 291 may be formed similar to the above-described holder of the muffler.

The serving both for catalytic exhaust gas purification and also for silencing apparatus 251 can for example be installed in place of the first muffler 19 in the visible in Fig. 1 exhaust 12th The catalyst 14 of the exhaust 12 then serves only as a pre- and / or start-catalyst and can be made relatively small. The device 251 can also be the catalyst 218 and the first muffler 222 of 18 drawn in Fig. 212 exhaust replaced.

The motor vehicle and its exhaust system can be modified in various ways.

One can also combine characteristics of different embodiments with each other in particular. One can Example, in the drawn in Fig. 18 Exhaust 212 still provide an initial and / or start-catalyst rigidly connected analogously to the catalytic converter 14 in FIG. 1 with the inlet and collecting apparatus 213 and upstream of the first elastically deformable pipe member is arranged.

If a motor vehicle has an exhaust system with more than one exhaust, each exhaust may be connected to some cylinders of the engine of the vehicle and formed in the rest in the manner described. When the engine consists of a diesel engine, the catalyst can be omitted. Further, the exhaust may have a single muffler policy.

Possibly you can at the apparent in Figures 1 and 18, exhaust 12, 212, respectively one of the two elastically deformable pipe members 16 and 18 or 216 and 218 omitted.

When the motor vehicle consists of a truck or bus or the like, the pipes and mufflers can have larger diameters than in a passenger car. The wall thicknesses of the pipes, the downstream of at least one elastically deformable pipe member and the vehicle body held catalyst and / or silencer casing and the intermediate walls and inner sheaths can however be still, for example, only about 0.5 mm or a little more. Further, the holder can be fixed then optionally at least partly on the frame instead of on the vehicle floor of the vehicle.

may farther Des you may connect each case only with three at least partly elastic connecting members to the vehicle body. The three connecting members should then do not all lie on one and the same straight line and in a perpendicular projection on the plane on which the vehicle stands, preferably form a triangle. Furthermore, you can possibly connect at least one or each silencer with only one bracket to the vehicle floor and / or frame. Possibly, a down stream preferably downstream secured by at least one elastically deformable pipe element and of two such arranged catalyst and / or silencer body even without rubber-elastic connecting members at a joint or several more or less joints rigidly to the vehicle body. Furthermore, the muffler or at least one of them may have a housing, the sheath in cross-section rather than, for example, is circular about oval.