Exhaust system for a motor vehicle as well as motor vehicle

The invention relates to an exhaust system for a one Vehicle body and an internal combustion engine exhibiting Motor vehicle connectable to a combustion engine with Exhaust, at least one deformable line member, at least one downstream from this arranged Tube and at least one downstream of said having pipe element arranged muffler, and with Holding means for holding the exhaust on the vehicle body.

The exhaust system, for example for a passenger car provided, the vehicle body frame and a one comprising vehicle floor. However, the exhaust system can possibly for another motor vehicle - for example, a lorry or bus - are used. The internal combustion engine can consist of a gasoline or diesel engine.

When using a motor vehicle are the internal combustion engine Vibration, ie vibration of the motor housing generated and the mechanical connection of this transferred to the exhaust on the latter. Further results the engine exhaust pulsating exhaust gas to which also vibrations can stimulate the exhaust. In exhaust possibility Vibrations with different vibration modes arise. The Oscillations of the exhaust cause periodic in time and relatively rapidly changing accelerations of the vibrating Parts of the exhaust. Further, the driving cause through holes and other irregularities, the cornering and the Acceleration and braking of the vehicle accelerations of Exhaust. These accelerations caused by driving normally change much more slowly than those produced by Vibrations caused accelerations. The exhaust is also heated during operation of the engine by the exhaust gas, wherein the exhaust gas temperature by the engine away along the flow path decreases. The heating effect due to the thermal expansion the rigid parts of the exhaust pipe a temporary extension of this. be In known passenger cars the lengths of the exhaust pipes, for example, about 4 m and the caused by changes in temperature changes in length to Example, about 0.5% to 1%, or about 2 cm to 4 cm.

From DE 30 26 730 A and DE 31 37 746 A and of numerous Passenger cars are exhaust systems with an exhaust and holding means known at the exhaust vehicle body having retaining rubber bands. If a force on a such retained part of an exhaust exerted, put the rubber rings of a deflection of the exhaust from its Rest position at first only a very small resistance contrary. Only when the deflections of the exhaust parts certain reach limits, increases the generated by the rubber rings Resistance skyrocketing. These limits are in the Practice usually about 1 cm to 2 cm, or possibly even more. Held by the holding means parts can therefore within the area bounded by the limits mentioned areas move almost freely. From US 5,323,989 A and the US 4,060,143 A are exhaust systems are known whose holding means also comprise elastic elements and at least in different directions a fairly free, limited movement the exhaust allow. From some of the cited publications and in practice it is also known that the Exhaust from the engine and the (first) silencer equip a deformable pipe member, for example, having a bellows or a rubber ring.

The known deformable pipe members serve in primarily as decoupling elements to the downstream of them arranged mufflers and other exhaust parts vibrationally decouple the engine. Since the known exhausts and in particular downstream of the deformable pipe elements arranged within parts can move certain limits rather freely, be in the exhausts despite the deformable pipe members often generated transverse vibrations of large amplitudes. This is particularly the case when the exhausts Resonances in the field of fundamental vibrations generated by the engine have. The vibrations and other on the exhaust acting accelerations and forces cause a strong Stress on the exhaust pipes belonging, silencer casings and deformable pipe members. The pipes an exhaust therefore have at least one passenger car 1.5 mm wall thickness amount. The silencers usually housing with coats and end walls, the wall thicknesses passenger cars also more than 1 mm and often be at least 1.5 mm. The exhaust pipes and Silencer housings of trucks have mostly yet greater wall thicknesses. The exhaust of the known exhaust systems is therefore difficult. It must also, in known exhaust systems often nor a weight enlarging heat shield between arranged the or each muffler and the vehicle floor will. 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 before especially fuel consumption when driving. Further contact despite the large wall thicknesses quite often breaks the exhaust on. Since the silencers of the known exhausts normally transverse to the general longitudinal direction of the exhaust starting of its central and / or rest position in different transverse directions until at least 1 cm and often up to 2 cm or even more are displaced, they consume an additional to the space they occupy even place for their Transverse movements. This often has the disadvantage of the consequence that the muffler can not be measured so large, as would be desirable for a good sound damping.

The US 5,331,810 discloses an internal combustion engine and an exhaust system with an exhaust. The latter has a first and second exhaust manifold. Each of this is rigid with three exhaust ports of the engine. The two Exhaust manifolds are interconnected by a connecting line connected, which has a bellows. The second Exhaust manifold is through a rigid catalyst feed the input of a catalyst connected. The connecting line and the catalyst supply line are essentially double-walled and have an inner tube and a Outer wall. The inner tube has a thin, only 0.46 mm thick Wall, so that between the engine and the catalyst located ends lines have only a small heat capacity. In contrast, the outer wall is at least 1.1 mm and Example 1,4 mm Amount border thickness and have a bearing Structure serve. Between the engine and the catalyst So existing lines, despite the small wall thickness the inner tube is a great weight. Further, the double-wall pipes and their connection through the bellows rather complicated and expensive production of the Exhaust system. Incidentally 5331810 A in the US not reveals how the downstream from the catalytic converter Exhaust parts are formed and maintained. From So the US 5,331,810 A known exhaust system has a heavy and complicated and expensive exhaust has to and probably otherwise at least partly related Disadvantages such as the annotated previously known exhaust systems.

The DE 44 23 939 A discloses a motor vehicle with a Internal combustion engine, a gearbox and an exhaust. Of the the latter has a catalyst, a flexible tube, a Silencer, a main silencer and some apparently rigid pipes. Further holding means are for holding the Exhaust available. The holding means each have two a tube connecting the exhaust pipe to the housing of the gear unit Holder and the inlet end of the pre with the vehicle body connecting to the holder. This document contains no information on the thickness of the pipe walls and Housing walls. It is therefore plausible that the wall thickness of the tubes and the housing as in most known Exhaust systems be at least about 1.5 mm and that the Exhaust is difficult accordingly.

The invention is based on the object disadvantages of avoid known exhaust systems and more particularly to an exhaust system create, with respect to that of the flow rate through the exhaust system to be derived exhaust gas and in respect to the length and the characteristic cross-sectional dimensions the exhaust has a light weight, yet durable is.

This object according to the invention is an exhaust system solved with the features of claim 1.

The invention further relates to a motor vehicle according to the invention comprising the features of claim 27th

Advantageous embodiments of the exhaust system go from the dependent claims.

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

In an advantageous development of the subject matter in the housing of the or each muffler a Layer of sound-absorbing and thermally insulating insulation material between the jacket of the housing, and a hollow interior available. Further, preferably between each end wall and the hollow interior of the or each Muffler sound-absorbing and thermally insulating Insulation available. If the exhaust a downstream the first elastically deformable pipe member and / or arranged below the vehicle floor catalyst , whose housing may likewise analogous arranged sound-absorbing and heat-insulating insulation materials exhibit. These insulating materials are preferably from 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 the or at least one or each under the Vehicle floor disposed housing allows the heat transfer on the vehicle floor in spite of thin-walled housing keep low and on the application of a metallic Heat shield to abandon the vehicle floor and in addition save weight.

According to the invention the holding means are adapted to the respectively at least the (first) along the exhaust in the exhaust gas flow direction on the first elastically deformable line member keep the following housing such on the vehicle body, that this or any case by the internal combustion engine vibrations produced and by the other to the exhaust acting accelerations and forces at least in rectangular all about the vehicle longitudinal direction Movement is more than slightly deflected. Such a relatively rigid mounting at least resonances Transversal vibration modes of the (first) downstream of the arranged (first) elastically deformable pipe member Housing and practically the whole of the downstream said conduit element arranged exhaust part largely suppressed. Accordingly, the oscillation amplitudes are and other changes caused by driving said exhaust portion is greatly reduced. this makes possible in turn, the elastically downstream of the (first) deformable pipe member disposed pipes and boxes thin-walled and easily trained and can still to achieve high exhaust of life. The reduction of transverse displacement also allows the diameter or other cross-sectional dimensions of a silencer body to enlarge without this vibration as a result of or other accelerations against the vehicle floor or other parts of the vehicle body abuts. Such Enlargement of a silencer body 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) elastic deformable pipe member is arranged, at least a holder, which is connected directly to the housing. It is then not necessary, the pipes themselves directly to the vehicle body to keep. Since a silencer and / or catalyst with a housing usually a larger mass and a greater weight per unit length as a tube, contribute directly to the or each housing engaging retaining means to a stable mounting and a low mechanical Stress on the various parts of the exhaust at.

The subject invention is then based on the Drawing exemplary embodiments shown. In The drawing shows <sl><li>FIG. 1 is a schematic, partly in view, partly in Average signed motor vehicle having an exhaust system,</li><li>FIG. 2 is a partly in view, partly in longitudinal section, signed elastically deformable line member of the exhaust system,</li><li>FIGS. 3 a longitudinal section through the first silencer the exhaust system,</li><li>FIG. 4 shows a cross section through the first silencer.</li><li>FIG. 5 shows a longitudinal section through the second silencer 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 silencer and a fastening thereof serving holder,</li><li>Fig. 8 is a section through a holder 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 silencer,</li><li>FIG. 10 is an axial section through a variant of a connecting member a holder,</li><li>FIG. 11 is an axial section through yet another link member a holder, </li><li>Fig. 12 is a to Fig. 7 with another analog representation Holder,</li><li>Fig. 13 is a plan view of parts of the holder according to FIG. 12,</li><li>FIG. 14 is a to Fig. 7 analog representation with a other holders,</li><li>FIG. 15 is a plan view of parts of the Fig. 14 apparent holder,</li><li>FIG. 16 is a to Fig. 7 analog representation with a other holders,</li><li>Figs. 17 a to FIG. 7 analog display with even 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 is a longitudinal section through a housing, the catalyst means and includes a portion of a muffler forms.</li></sl>

The schematically drawn in Fig. 1 the 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 on. The vehicle body 2 holds an internal combustion engine 6, front wheels 7, rear wheels 8 and as a whole designated by 11 exhaust system. The internal combustion engine 6 has a vibration-damping on Rack 5 mounted motor housing 6a with multiple exhaust outlets, each of which a cylinder of the engine associated with is. The exhaust system 11 has as a main ingredient a Exhaust 12. This has in the direction of flow of the exhaust gas the series, an inlet and collecting device 13, a Catalyst 14, a short pipe 15, a first elastically deformable Line element 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 an opening into the surrounding outlet 24. The internal combustion engine 6 is located at the forward end of the motor vehicle 1. The exhaust 12 extends generally about parallel to the longitudinal and driving direction of the vehicle 1 from 6 engine to the rear of the vehicle and located for the most part below the vehicle floor 4. The exhaust system 11 also includes holding means 27. These include four Holder 28, 29, 30, 31 on which the two silencer 19 and 23 in the vicinity of its ends to a rigid part of the Vehicle body 2 which is connected to the vehicle floor. 4

The inlet and collecting apparatus 13 includes an exhaust manifold, of a bent for each exhaust outlet of the engine having inlet pipe, whose input is connected to one of exhaust ports the motor housing is connected. The device 13 also includes the outputs of the intake pipes together connecting bus connection means and for all intake pipes common output 13a. The inlet and collecting apparatus 13 is, for example, completely rigid, but can possibly at least an elastically deformable coupling element having a bellows or the like, the one of the intake pipes to the common output 13a connects. The common output is 13 but rigidly by the collector connecting means having at least one the input pipes and be connected to the motor housing 6a. The catalyst 14 has a rigid housing having an input, rigidly connected to the common output 13a of the intake and is collecting device 13. The pipes 15, 17, 20, 22, 24 are rigid. The inlet and collecting apparatus 13, the housing of the catalyst 14 as well as the pipes 15, 17, 20, 22 and 24 are made of metallic materials, for example, stainless steel. The apparatus 13, the casing of the catalyst 14 and the pipe 15 are sealed together, namely welded.

The three elastically deformable pipe members 16, 18, 21 are shown in FIG. 1 only schematically shown, and have for example, a metallic, namely stainless steel existing, flexible, bendable, extendable and retractable Bellows having its ends tightly and firmly with the respectively preceding and succeeding exhaust parts, welded for example, directly or indirectly are. The pipe members 16, 18, 21 can still additional have parts. The second elastically deformable line member 18 is formed, for example, according to FIG. 2 and has as main components a bellows 33, a to within this fluid control inner sleeve 34, a the Bellows in cross-section enclosing, as a protective coat serving outer sleeve 35 and a sleeve 36. The line element 18 also has a cross-sectionally approximately U-shaped Ring 37 with an open to the outside groove and a in this held, deformable damping element 38th This is characterized by a multi-ply, into a ring with full exterior section formed shaped wire mesh and projects out of the channel of the ring 37 out. The parts of the said Line element 18 are made of metallic materials, such as stainless steel. The bellows 33 has to both ends of a cylindrical end section and is at his in the Fig. 2 left located ends end rigidly and tightly connected to the ends of the two sleeves 34, 35, namely welded. These ends of the corrugated bellows 33 and the Sleeves together form the first terminal 39 - namely the Input - the line element 18. The in the Fig. 2 Right exploiting dividend end of the corrugated bellows is fixed and sealed with the other end portion of the sleeve 36 and the ring 37 connected, namely welded. The other, narrower End portion of the connecting piece 36 forms the second port 40 - Namely, the output - of the line element. The inner Sleeve 34 projects into the other end portion of the connecting piece 36 in. The cylindrical main section of the inner sleeve 34 is through annular gaps of the inner shaft of vertices Corrugated bellows 33 and separate the inner surface of the connecting piece 36th The outer sleeve 35 has a cylindrical central portion, the outer by a gap of the wave summits the corrugated bellows is separated and has some holes. Of the in the Fig. 2 right exploiting dividend end of outer sleeve 35 is bent inwards and engages a Portion of the damping member is 38. The line element 18 generally rotationally symmetrical about an axis 41st

The first and third elastically deformable Line element 16 or 21, for example equal to or formed similarly to the second elastically deformable Line element 18. The pipe members 16, 18, 21 may However, different dimensions and / or designed and be changed in various ways. The inner sleeve 34 For example, to enlarge the flexibility of Corrugated bellows are omitted. Further, the outer Sleeve 35, the ring 37 and the damping element 38, for example, especially the first line element 16 or at all line elements 16, 18, 21 through a flexible, expandable and retractable, from wires or metal strips formed shell be replaced.

The first elastically deformable line member 16 in particular serves as a vibration damper and decoupling element and is intended to be with respect to the exhaust gas flow direction located downstream ends of the pipe member 16 12 decouple parts of the exhaust from the motor vibrationally and as far as possible to prevent the operation from Engine vibrations or vibrations produced by the motor housing the downstream ends located by the line element 16 Exhaust parts are transmitted. The second and third Line element 18 and 21 also serve to more moderate vibration Decoupling. The first and the second conduit element 16 and 18 are located downstream of them located ends Exhaust parts also in relation to other, ie not by vibrations caused movements, in particular Tilting, decouple from the motor housing.

The corrugated bellows of the three line elements 16, 18, 21 and in particular of the second and third conduit member 18 and 21 may further under elastic deformations their lengths change and in particular starting from their sleep states be shortened along their axes. When separately in Fig. 2 drawn second line element 18 are then the two Sleeves 34, 35, for example starting from subscribed, with resting motor occupied hibernation right against the terminal 40 is displaced. Parallel to the axis 41 the line element 18 measured distance between the two terminals 39, 40, ie the length of the line element can preferably at least 5 mm and, for example, to about 10 mm or even a bit m ore changes, ie starting from an idle state is reduced and / or increased. The first and the third line element 16 or 21 can its length is also preferably at least 5 mm and, for example, Change to about 10 mm or more, that is, starting collapse of an idle state and / or enlarge.

The two conducting members 16 and 18 by temperature changes can caused changes in length of the upstream the first muffler 19 located the pipes 15 and 17 and other solid parts exhaust balance. The two pipe members 16, 18 can thereby together with 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 compensate for that to a minimum 5 mm or at least 10 mm or even up to about or be more than 20 mm. The third line member 21 may Changes in length between the two silencers 19, 23 located the pipes 20, 22 to compensate. The third line element 21 may changes in length and / or other Dimensional changes in 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 offset direction until at least 5 mm and, for example, to at least 10 mm.

The separately in Figures 3 and 4 apparent, first Silencer 19 has an elongated, tight housing 45, the generally rotationally symmetrical to a straight Axis 46 is. The wall of the housing 45 has a substantially cylindrical shell 47 and two side facing away, tightly and firmly connected to the casing end walls 48 or 49. The two end walls for stiffening the housing For example, at least partially conical or curved. The housing 45 includes two gas-permeable partitions 50, 51, each of which extends in the vicinity of a End walls 48, 49 and is of a substantially planar, annular disc consists. The two intermediate walls 50, 51 are perforated at least in places, and have to Achieving good stiffness preferably also at least a compact, non-perforated area. Of 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 49, respectively. The partitions 50, 51 are fixed and more or less tightly connected to the jacket 47 and / or with the tube 53 and 54, respectively and have, for example, by Spot welding connections on the jacket fastened flanges. The outer end of the tube 53 forms the input terminal of the Muffler 19 and is connected to the conduit member 18th The outer end of the tube 54 forms the output terminal the silencer 19 and is connected via the pipe 20 with the lead member 21 connected. Each tube 53, 54 has in close to its inner end a gas-permeable, perforated Section 53a and 54a. The tube 54 has between its 54a perforated portion and its as output terminal serving end still serving as a choke 54b Constriction. The inner ends of the two pipes 53, 54 are in the axial direction separated by a gap from each other. The inner end of the tube 53 is by crimping more or less sealed or may be open. The inner end of the tube 54 is pinched together and more or less sealed. The housing 45 contains between the two intermediate walls 50 and 51 of a generally cylindrical inner shell 55. This consists of two sleeve-shaped inner shell parts, each on a End is attached to one of the intermediate walls 50, 51st The other, the intermediate walls facing away from end portions of the two Inner shell parts enclose each other with a maximum small game and are parallel to the axis 46 against each other displaced. The two-piece inner shell 55 is in the largest Part of its length gas-permeable and perforated but has a compact near his left located ends end, ie hole-free portion 55a, which surrounds the axis 46, over approximately the length of the perforated area Pipe section 53a extends and example to both ends slightly project beyond the latter. The in is exploiting dividend within the housing portion of the pipe 45 54 is longer than half the length of the housing and is at its inner end with a few rod-shaped supports 56 supported on the inner casing 55th The housing 45, the partition walls 50, 51, the two tubes 53, 54, the inner casing 55 and the supports 56 are made of metallic materials, for example, stainless steel. The between the end wall 48 and the intermediate wall 50 and between the end wall 49 and the Between existing wall 51, the pipe 53 and 54 respectively enclosing, annular gaps are coated with a layer or filling of heat-insulating and sound-absorbing Material 57 or 58 is filled. The ring-shaped in cross-section Intermediate space which extends between the two intermediate walls 50, 51 and between the shell 47 of the casing and the inner casing 55 is, is also provided with a layer of heat-insulating and sound-absorbing material 59 is filled. The materials 57, 58, 59 consisting for example of fibers referred to in the introduction. In contrast, the cross-sectional the inner casing 55 enclosed between the two Partitions 50, 51 existing interior 60 - apart from the tubes 53, 54 and supports - 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 includes a cylindrical casing 67 and two End walls 68, 69. The housing includes two disk-shaped, at least in places, gas-permeable, perforated partitions 70, 71. The silencer 23 has two pipes 73 and 74. The tube 73 passes through the end wall 68 and the partition wall 70. The tube 74 passes through the end wall 69 and 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 pipes 73, 74 are parallel to the axis 66, but on different sides disposed of this.

Further, the two tubes 73, 74 next to each other in the same longitudinal section of the housing 65 exploiting dividend portions. The outer end of the tube 73 forms the input terminal of the second muffler 23 and is connected to the pipe 22. The tube 73 is at its located in the housing 65 squeezed located ends end and more or less tightly sealed or open and has in the vicinity of this end a gas-permeable, perforated section 73a. The Tube 74 is open at its inner end and has no perforated Section. The outer end of the tube 74 forms the Output terminal of the second silencer 23 and is connected the exhaust pipe 24 is connected and / or forms of this. Of the second silencer 23 has an inner shell 75, the like the first muffler of two interlocking protruding, mutually displaceable inner shell parts. Of the Inner sheath 75 is mostly gas-permeable and perforated, but has a compact, non-perforated section 75a. This extends over a somewhat longer longitudinal region as the perforated portion 73a of the tube 73, surrounds However, the axis 66 is not complete, but takes only amid a school near the tube 73 circumference area of the inner shell a.

The two between the end walls 68, 69 and one of the gas-permeable partitions 70 and 71, existing gaps contain a material 77 or 78. The between the body shell 67 and the inner shell 75 existing gap containing a material 79. The materials 77, 78, 79 in turn, are heat-insulating and sound-proofing and consist of mineral fibers. The between the two Between walls 70 and 71 present, in cross-section from the inner sheath 75 enclosed interior 80 is apart from the Tubes 73, 74 hollow and free. Unless stated otherwise been written, the second muffler 23 is similar formed as the first muffler 19th

The schematically drawn in Fig. 1 holder 28, 29, 30, 31 for securing the two mufflers 19 and 23 may - Depends on the education of the vehicle floor 3 - different designed and dimensioned or all the same be. Both for fastening the first silencer 19 serving holder 28, 29 are, for example, the same or similar formed, standing along the silencer axis 46 at a distance from each other and are in the vicinity of both ends the muffler 19, namely at its partitions 50 and 51 attached to its shell. The holder 28 is to Example according to the figures 7 and 8 is formed. In the figures, 7 and 8 is also a segment of the vehicle floor 4 visible. This is, for example, generally more or less flat but has an upwardly projecting bulge. This defines an open towards the bottom groove, which often called tunnel and in which at least a portion of the exhaust 12 and especially at least one Cross-sectional area of ​​the end view in shown in Fig. 7, the first muffler 19 is located.

The holder 28 has a directly on the housing 45 of the first Silencer 19 engages retainer 85, and two the latter connecting with the vehicle base 4 connection members 87. The retaining member 85 consists of a metallic Material, such as stainless steel. The retaining member 85 is rigid, elongated and at right angles to the silencer 19 arranged and essentially consists of a u-profile bar 85b with a web 85a and two limbs. The U-profile bar is at the ends of amplified by end members welded to the legs and either with the web welded or are contiguous with this. The middle one Portion of the holding member 85 is parallel to the jacket 47 of the silencer body 45 is bent, is located with the outer, Up located ends surface of the web 85a on the lower Side of the silencer body 45 on the casing 47 and for example by a few spot welds or other welding connections on the casing 47 mounted. Each connecting member 87 is at least partially elastically deformable and consists for example of a one-piece, rubber elastic body or elastic body made of synthetic and / or natural Rubber. Each connecting member is substantially rotationally symmetrical to an axis and having a generally cylindrical, but in the central region in axial slightly indented main section 87a. This has his whole axial dimension a full cross-section and therefore contains no free cavities or gaps or holes. The main portion 87a has on its both ends flat annular support and / or end faces and depends the middle area of ​​each end in the axial direction with a of this project away, approximately mushroom-shaped extension together, the fastening and / or connecting means 87b or 87c forms. Both the same holder 28 and 29, belonging connecting members 87 are provided along the retaining member 85 of that keeper staggered and in the Near the ends of the retaining member arranged. Each connecting member lies with the flat support and / or end faces of his 87a main portion 85a on the upper surface of the ridge of the holding member or on a portion of the lower surface the vehicle floor of the fourth The mushroom-shaped fastening and / or Connecting means 87b, 87c are in the assembly the exhaust under a temporary elastic deformation through holes in the web 85a or vehicle bottom 4 plugged and grab this one, so that the heads of the fastening and / or connecting means the web 85a and the Vehicle floor 4 engage behind. Connect the connecting members 87 the holding members 85 and welded at this first muffler 19 then releasably connected to the vehicle floor. 4

Thus, the first muffler 19 is in the assembled state by four connecting members 87 to the vehicle floor 4 of the Vehicle body 2 held. The four connecting members 87 together form a 4-point suspension. The centers of the four first muffler retaining connecting members 87 define in a vertical projection onto a horizontal Level at which the motor vehicle 1 is a rectangle, For example, a rectangle. In this case, on each side of a through the axis 46 extending vertical plane two connecting members available.

The second silencer 23 is, for example, in Near the rear end of the vehicle 1 behind its Rear axle under a more or less planar portion the vehicle floor 4 is arranged. 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, elongated, 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 to the connecting members 87, however, protrude from the top 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 muffler For example, the same or similar design to the front holder 30. As far as written previously otherwise was, the holders 30, 31 are of identical or similar and attached to the muffler and the vehicle floor such as the holder 28, 29th

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

The catalyst 14 and the pipe 15 are through the inlet and collecting device 13 rigidly connected to the motor housing 6a connected. The rubber-elastic connecting members 87, 97 of Holder 28, 29, 30, 31 allow, due to their elastic Deformability small deflections of the silencer housings 45 and 65 from the rest positions of these housings. From produce compact rubber bodies existing connecting members However, even at very small deflections in any direction These counteracting restoring forces with increasing Deflection within a certain range steadily monotonically and for example more or less linearly to the displacement to grow. allow the connecting members 87, 97 So certain, but only relatively small movements of the silencer body. The connecting members also give a antivibration compound of silencer casings with the vehicle body. The connecting members 87, 97 of the holder 28, 29, 30, 31 are preferably formed such that each Silencer housings 45, 65 in the assembled exhaust by acting on one or each housing 45, 65, constant, stationary acceleration of 10 m / s² and example even 20 m / s² or even 50 m / s² or one constant, steady force of 100 N in any direction of the vehicle body at most 5 mm and preferably more than 2 mm from the middle and / or rest position of the relevant The housing is deflected. The housing 45, 65 are then in the assembled exhaust especially by accelerations or forces said sizes and some have an arbitrary direction and example approximately parallel to the longitudinal and main driving direction of Motor vehicle and approximately parallel to the axes 46, 66 of the Housing 45, 65 are or example for any Longitudinal direction of the motor vehicle and about the axes 46, 66 have right-angled direction, not more than 5 mm and preferably more than 2 mm from a central and / or rest position deflected or moved. The holder can, for example, be designed such that the deflections of the two Silencer casings in the said accelerations or Forces also are within the ranges mentioned, when the housing 45, 65 remaining on the exhaust parts and are separated.

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

Present in the silencer tubes 53, 54, 73, 74 are also heated by the exhaust gas and also lengthened. There these tubes at only one end on the housing of the respective Muffler mounted and at the other end are free, can they shall 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 slidably is producing changes in length of the inner shell parts also no tension.

The existing in the housings of the silencer, from Fibers existing materials 57, 58, 59, 77, 78, 79 isolate the jackets 47, 67 thermally from the exhaust gas, so that these coats at most relatively slightly by the exhaust gas at temperatures of for example about 100 ° C to 300 ° C are heated. Further, it is thereby avoided that the rubber body the holders are damaged by heating. Since the Coats 47, 67 heated by the hot exhaust gas at most little be, the high temperature of the exhaust gas also causes at most small extensions of the jackets 47, 67. This is the total extension of the exhaust over a conventional Exhaust with enclosures without thermal insulation reduces. The extention of the housing can be achieved by deformation the rubber-elastic connecting members of the holders be included. The heat insulation is at least largely avoided that the hot exhaust gas tension in the Coats produced, although these almost motionless at both ends are connected to the vehicle floor.

containing the materials 57, 58, 59, 77, 78, 79 Interstices of the muffler are through the perforation of the intermediate walls 50, 51, 70, 71 and inner sheaths 55, 75 through flow with the hollow, free from exhaust Indoors 60 and 80 respectively. The consisting of fibers, sound-absorbing materials produce therefore an essential Improve soundproofing.

The thermally induced changes in length of the pipes 15, 17, 20 and the changes in length of the silencer body at least for the most part by the elastically deformable Pipe members 16, 18, 21 balanced. It therefore act at most small changes in temperature caused stresses and forces on the pipes and mufflers on. Mufflers are thermally by the induced changes in length of the pipes and the resulting 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 deformable by the Connecting members 87, 97 shifted generated restoring forces, and such any possible shifts in the silencer are approximately parallel to their axes.

As already described in the introduction, may be obtained at Use of the motor vehicle by the vibrations of the motor housing and the pulsating exhaust vibrations of various excited exhaust parts and also by driving caused to the exhaust parts acting accelerations will. The mufflers have from the downstream of the first arranged elastically deformable pipe member 16 Exhaust parts, the largest mass per unit length. The somewhat mobile, resilient and vibration damping, but rather rigid connections of the silencer the vehicle body 2 prevent strong vibrational resonances Vibrations of large amplitudes and other larger movements the muffler. The pipes 15, 17, 20, 22 and in particular the two silencers 19, 23 are represented by the during normal operation of the internal combustion engine vibrations generated and the most excited by the pulsating exhaust Vibrations in all directions greater than 5 mm, preferably highest 2 mm and typically at most 1 mm or even only more than 0.5 mm is deflected from their center positions, they after reaching the operating temperatures due to the thermal taking dimensional changes. The in normal driving of the motor vehicle through uneven terrain, curves, Acceleration and braking caused and to the Exhaust acting accelerations caused deflections from said middle layers be in all directions also more than 2 mm and typically at most 0.5 mm. Furthermore, be the entire silencer deflections, by temperature changes, vibrations and caused other accelerations, starting from the space 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 arranged first elastically deformable pipe member 16 Pipe does not need large by the vibrations or driving caused accelerations and forces receive. The pipes 15, 17, 20, 22 therefore need substantially only their own weight and possibly also partly the weight the elastically deformable pipe members 16, 18, 21 to wear. It is therefore not necessary, the pipes 15, 17, 20, 22, 24 by directly engaging themselves Holder to keep the vehicle body. The pipes 15, 17, 20, 22, 24 and present in the silencer tubes 53, 54, 73, 74 can also be made relatively thin and have Wall thicknesses, at least substantially not exceeding 1 mm, better than 0,8 mm and for instance approximately 0.5 mm. It should be noted that the pipes associated with them overlapping parts at the connection points may can, so that there may exhaust sections slightly thicker wall thicknesses result. These optionally present, but thicker sections are then relatively short and much shorter than the whole exhaust. The walls of the tubes the exhaust manifold of the inlet and collecting apparatus 13 can possibly also slightly thinner than conventional, not inventive exhaust systems are dimensioned and possibly similar thicknesses as that of the catalyst 14 tubes arranged. The shells 47, 67, end walls 48, 49, 68, 69 and intermediate walls 50, 51, 70, 71 and inner sheaths 55, 75 of the two silencers likewise need only minor exhibiting wall thicknesses. These wall thicknesses are at least in the largest part of these coats and walls at most 1 mm, better at most 0.8 mm, and for example, about 0.5 mm.

The between the shells 47, 67 and the inner sheaths 55 or 75 of the muffler existing, consisting of fibers Materials 59 and 79 form layers, which in cross section measured in the radial direction of layer thickness at least 10 mm and, for example, be approximately 20 mm. The axial Direction measured dimensions of between one end wall and a partition wall existing 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 element 101 is of a composite body and is substantially an Axis rotational symmetry. has the connecting member 101 a substantially cylindrical from natural and / or synthetic rubber existing rubber body 102, which at each its two ends is provided with a recess. Each recess includes a flat plate 103 with a central hole and the head of a fixing and / or Connecting means 104 forming the hole of the plate piercing screw with an axially from the rubber body 102 projecting away threaded portion. The two plates 103 and the Fixing and / or connecting means 104 consist of a metallic material, such as steel and are by casting and / or vulcanization of the rubber and / or by gluing or the like firmly and inextricably linked to the Rubber body connected. The rubber body has between the plates 103 and fastening and / or connecting means 104 filled recesses a full cross-section. The platelets 103 and these enclosing edges of Rubber body 102 together form flat support and / or end surfaces the connecting member one hundred and first

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

It can be apparent in some or all of the Figures 7 to 9 Connecting members 87, 97 of the holder 28, 29, 30, 31 replaced by connecting members 101 and / or 111th The or each connecting member 111 may then, for example, by the Connecting means 114 having a holding member and by the fastening means 115 to the vehicle floor or ungekehrt get connected. The vehicle floor 4 can then accordingly with welded threaded bushes or threaded bolts or the like are provided. Furthermore you can Features the connecting members 87, 97, 101, 111 combine provide and example compound organs at one end of a mushroom-shaped appendage of rubber and on other end a screw or threaded bushing or both having ends of the rubber body Gewindebbuchsen. Further, Connecting members are provided, at least at formed one end of a like a self-tapping screw have threaded part or riveting or welding on are formed. In addition, the rubber body can at least one end of a multi-edge-shaped end portion for engaging comprise a key or even in cross-section substantially completely the shape of a regular polygon, have about a 6- or 8-gon.

The between the two support and / or end surfaces measured, axial dimension of the main portion 87a of the completely Rubber existing connecting member 87 and the Rubber body 102, 112 is for example about 50% to 150% the maximum diameter of the respective rubber body. Of the maximum diameter is in an exhaust system for a Passenger cars further preferably about 15 mm to 50 mm. Said axial dimension can be about 10 mm to 50 mm be.

The means of attachment of the first muffler 19 Holders 28, 29 can be replaced by holders, one of which one drawn in Fig. 12 and partially in Fig. 13 and is designated by the 121st The holder 121 comprises as main components one directly on the housing 45 of the silencer 19 engages retainer 122, a fixed to the vehicle floor 4 Support member 123 and the latter two with the retainer 122 connecting link member 125. The retaining member and the supporting element consist at least essentially of a metallic material such as stainless steel, while the connecting members 125 at least to a large made part of elastomeric material and the same or similar to one of the connecting members previously described 87, 97, 101, 111 is formed. owns The retaining member 122 a cloak 47 of the muffler 19 surrounds Bride 126 and a arranged at the ends of closure 127 and is removably attached to the muffler housing 45th The Supporting member 123 is composed for example of a multiply angled Flat profile bar or U-profile bar. The support member 123 is arranged below the muffler 19 and on opposite sides of the latter with fastening means 129 detachably or permanently secured to the vehicle floor 4. The fasteners 129 have, for example, sheet metal screws or normal metal screws on which through holes the support member 123 and into the vehicle floor 4 and / or screwed into this welded on threaded bushings are. However, the screws could by locking elements substituted or rivets or other fastening means be.

Each or at least one of the holders 28 to 31 can for example, according to the in the Fig. 14 and in part in of Fig. 15 apparent holder be formed 131st In the Fig. 14 are similar as in Figs. 7 and 12, a cut- the vehicle floor 4 and the muffler drawn 19th Of the Holder 131 has a fixed to the muffler holding member 132, a fixed to the vehicle floor support member 133 and two Connecting members 135. The retaining member 132 has, in turn, a Bride 136 with a closure 137 and two additional angled tabs 138, whose one ends to the Bride are attached, and projecting from this. The support member 133 consists of a straight U-section bar, whose ends with fastening means 139 are attached to the vehicle floor. 4 The a rubber body having connecting members 135 are in its one upper end to one of the tabs 138 and at its fastened the other end to the support member 133rd

In the depicted in FIG. 16 variant of the vehicle floor 4 is its upwardly bulge less high as in the Fig. 7, so that a cross-sectional area of ​​the Muffler 19 below from the limited of the bulge Tunnel projects. The drawn in Fig. 16 Holder 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 portion of Profile bar 147 is in accordance with the arrangement of the muffler bulged downwardly and on both sides of Bulge attached to the Bride. The connecting members 145 are in the vicinity of the ends of the profiled bar 142 is located and connect it to the vehicle floor. 4

The drawn in Fig. 17 Detail of the vehicle floor 4 has a throat and / or an asymmetrical, downwardly open tunnel, in which the producer to the silencer 19 at least is partly. The in the Fig. 17 apparent holder 151 has a retainer 152 with a the muffler enclosing Bride and one of these fastened multiply angled and / or bent Rod whose ends by connecting members 155 to the vehicle floor 4 are connected.

Unless stated otherwise above written, are Similarly, the apparent in Figures 12 to 17 holder formed as described with reference to Figures 7 and 8 Holder 28 and have connecting members, one of the connecting members 87, 97, 101, 111 are identical or similar.

The 18 visible in Fig. Motor vehicle 201 is, back 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 having a Exhaust 212. This comprises - starting the engine - along the exhaust flow path of the series, an inlet and Collecting device 213 with an exhaust manifold and a common output 213a, a first elastically deformable Line element 216, a rigid tube 217, a second elastically deformable line member 218, a Catalyst 219, a tube 220, a third elastic deformable line member 221, a first Silencer 222, a tube 223, a fourth elastic deformable line member 224, a pipe 225, a second muffler 226 and an outlet 227 on. Of the Catalyst 219 is thus downstream from the elastic deformable pipe elements 216, 218 arranged and is located below the vehicle floor 204. The Catalyst 219 is elongated and has a about the longitudinal direction the motor vehicle parallel axis and a housing 235 with a casing 237 and two end walls 238, 239. The Sheath 237 has in cross-section, for example the shape of a flattened oval or a circle. The end walls 238, 239 for example, at least partially conical and / or curved and inclined to the axis. The housing 235 contains Catalyst means for the catalytic cleaning of the exhaust gas. The casing and the end walls of the housing of the catalytic converter 219 can similarly have small wall thicknesses, as earlier specified for the silencer casings of the exhaust 12 has been. The catalyst housing 235 may possibly sound absorbing and contain heat-insulating fiber materials, arranged analogously ih the silencers of the first described exhaust 12th

The exhaust system 211 has still retaining means 241 which the housing of the catalytic converter and muffler of the two at the keep vehicle floor 204th The holding means comprise two holders 243 for holding the catalyst housing 235 and two holders 244, 245 for holding the housing of the silencer 222 or 226. The holder 243, 244, 245 are identical or similar formed as the holder and the previously described in particular have each two connecting members on that very or partially made of a rubber body. Unless stated nothing was written, the exhaust system be 211 formed identically or similarly to the exhaust system 11th

The 19 visible in FIG. 251 device forms a combined catalyst-silencer and has an elongated Housing 255 with an axis 256, a jacket 257 and two end walls 258, 259 on. The housing 255 includes, for example, similar to the muffler housing the exhaust 12 two gas-permeable intermediate walls 260, 261, a gas-permeable inner casing 265 and heat insulating and sound-absorbing fiber materials 267, 268, 269. The shell 257, the end walls 258, 259, the intermediate walls 260, 261 and the inner surface 265 may be formed similarly 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 has at its end walls provided with 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 flows in the intermediate wall 260 in the first interior region 277. The outlet 272 is formed by a tube protrudes into the second interior portion 278 and, for example, similarly formed as shown in Fig. 3 apparent 19 are pipe 54 of the silencer The catalyst means 275 for catalytic purification of the exhaust gas and have a Plurality of passages including the first to the second interior region connect. The catalyst means 275 can For example, two V-shaped arranged catalyst bodies comprise and be similarly formed as from the US 5,593,645 A and the corresponding EP 0676535 A known is. The content of these publications is hereby incorporated in this Registration included if 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 previously described holders of the silencers.

The both for catalytic exhaust gas purification as well as for Silencing device serving 251, for example, instead of the first muffler 19 in the visible in Fig. 1 Exhaust 12 are installed. The catalyst 14 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 219 and the first Silencer 222 of 18 drawn in Fig. 212 exhaust replace.

The motor vehicle and its exhaust system can still different ways to change.

One can in particular characteristics of different combine embodiments together. One can as Example at the 18 drawn in Fig. 212 Exhaust yet a pre- and / or start-catalyst provide the analog rigid as the catalyst 14 in FIG. 1 with the inlet and Collecting device 213 connected upstream and the first elastically deformable pipe member is disposed.

If a motor vehicle, an exhaust system with more than one has exhaust, exhaust each can with some cylinders the internal combustion engine of the vehicle and in the rest be formed in the manner described. When the motor consists of a diesel engine, the catalyst can be omitted will. Further, the exhaust may possibly only one have silencers.

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

When the motor vehicle from a truck or bus or the like, the pipes and silencers can larger diameter than have in a passenger car. The wall thicknesses of the pipes, the downstream of at least arranged an elastically deformable pipe member and held on the vehicle body catalyst and / or Muffler housing and the partition walls and inner coats but can still, for example, only about 0.5 mm or be little more. Further, the holder can then possibly at least in part on the frame instead of on the vehicle floor be vehicle mounted.

Further, the silencer or at least one of them have a housing whose Coat in cross-section rather than circular, for example, about Oval is.