DE1480626A1 - Exhaust pipe made of plastic for motor vehicles - Google Patents

Description

WALKER MANUFACTURING COMPANY

Exhaust pipe made of plastic for motor vehicles

The invention relates generally to exhaust systems for internal combustion engines and in particular an improved exhaust pipe for the same.

The invention relates generally to an improved exhaust system overcoming various problems posed by the extraordinarily large production volumes and the large number of different types of motor vehicles that have occurred in recent years have been manufactured. The invention particularly relates to overcoming certain problems arising from the fact reveal that virtually every different automobile model in its exhaust system has an exhaust pipe of a special size and distinctly different configuration «Apart from the significant costs for relevant machine tools and capital investments, how they are required to produce such a large number of different exhaust pipes emerge significant problems with the inventory and availability of such exhaust pipes, and these problems continue to be exacerbated due to the high space requirements of typical exhaust pipes. Another problem arises on the basis of the described order “Length when transporting such a large number of exhaust pipes from manufacturers to large and small distributors. According to the invention, an exhaust pipe is created through which the problems with regard to accessibility, storage and transport can be overcome by using a practically flexible and deformable

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Bares pipe for the exhaust gas is proposed in standard lengths and diameters can be made available so that it is at can be installed in practically any vehicle model «,

According to the invention, the exhaust system for an internal combustion engine an exhaust pipe made of plastic. According to the invention, a method is also used to produce a An exhaust system for internal combustion engines has been considered, in which a plastic pipe is used, which is practically flexible and deformable in a semi-hardened state and practically rigid and is not deformable in the fully hardened state, as well as such a pipe is installed when it is partially hardened State and the complete curing of the pipe is carried out, whereby it assumes a rigid working configuration.

An essential problem on which the invention is based is thus to provide an exhaust pipe that can be universally installed in virtually any model of motor vehicle.

There is a further problem on which the invention is based in creating an improved exhaust pipe that can be made either manually or with cheap or easily available crafts can be bent into a configuration appropriate to the contours of the vehicle frame and chassis of the concerned Motor vehicle corresponds.

There is a further problem on which the invention is based is to provide an improved exhaust pipe of the type indicated, which after bending into the appropriate configuration into a Motor vehicle built in an «extremely simple and economical Rigid can be subjected to the same thing is permanently fixed in the working configuration. There is a further problem on which the invention is based in providing an improved exhaust pipe of the type indicated

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U80626.

sohaffen, either in the form of large circular spirals or transported and stored in the form of rectilinear elongated pipes, thereby causing the traneport warehouse and related costs by greatly reducing the handling.

There is a further problem on which the invention is based in creating an exhaust pipe of the type indicated, the opposite the adverse effects of exhaust gas condensation, road salt, Weather conditions and the like. Is insensitive and thus has a significantly longer service life than conventional exhaust pipes.

According to the invention, an exhaust pipe with extraordinary created simple form, which can thus be produced economically.

According to the invention finds a hollow, elongated, the exhaust gases Pipe application made from plastic This pipe is supplied in a partially cured or catalyzed state, so that it is somewhat flexible and deformable and thus can easily be bent to conform to the underside of the particular motor vehicle on which it is to be placed. After the pipe has been arranged in its bent configuration on the corresponding motor vehicle, the same is subjected to a simple Rigid Maohen, which consists in the fact that the catalysis of the plastic is completed, whereby the pipe is practically rigid and fixed in its working configuration

The invention is described below, for example, with reference to FIG

the attached drawings explain:

Fig. 1 is a side elevation, partially broken away, of the invention

according to the exhaust pipe when it is placed on a conventional one

Motor vehicle engine and associated muffler. Fig. 2 is a quersei term cross section of an optional embodiment

shape of the exhaust pipe according to the invention.

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Pig. 3 is an enlarged, broken away side elevation, in part broken away, a further embodiment of the invention Exhaust pipe.

Fig. 4 is an enlarged broken away cross-sectional view of a further embodiment according to the invention

Fig. 5 is eleven. Side elevation of an exemplary embodiment the exhaust pipe according to the invention in spiral or rolled form before cutting and bending in the imple mentation form according to FIG. 1.

6 is an enlarged perspective view of FIG exhaust pipe according to the invention and aeigt a method of packaging or Bundling a variety of these components around the Traneport and the To facilitate storage of the same.

Referring to Figure 1, there is an exhaust system IO one conventional motor vehicle or similar internal combustion engine 12 arranged, which has a main pipe 14 for the exhaust gas connected to the inlet end of a conventional muffler or muffler 16 is connected via a pipe 18. The opposite or outer end The muffler 16 is connected to an elongated Auepuffrohr 20, which is constructed according to the invention and serves to control the exhaust gases from the muffler 16 to the rear end of the corresponding Supply motor vehicle, from where the gases are released into the outside air.

The exhaust pipe 20 is made of plastic of a resinous composition, which can best be described as a mass with multi-level hardness properties. The exhaust pipe 20 is particularly made of plastic containing a synthetic resin and in the partially hardened state (hereinafter referred to as B-stage is somewhat deformable and flexible, whereby the resin or the plastic in the fully hardened state (referred to as C-stage) practically rigid and not deformed internally.

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shafts result due to a multi-stage catalytic conversion, which enters inside the plastic and is controlled by selective regulation of the temperature and / or chemical conditions to which the material is exposed.

According to the invention, the exhaust pipe 20 is used to be installed on a motor vehicle when the same is in the partially hardened state (B-stage), whereby the exhaust pipe 20 can easily be bent into a configuration, either manually or with easily accessible ignition tools, that the chassis - and frame parts on the rear of the corresponding motor vehicle. So mused for PIB. a bent portion 22 can be formed in the exhaust pipe 20 to prevent interference between the exhaust pipe and the rear axle of the automobile. After the exhaust pipe 20 has been appropriately trimmed into a desired configuration, it can be rigidly attached by means of conventional mountings 24 to suitable adjacent parts of the frame or chassis of the motor vehicle, as shown in FIG. 1.

The exhaust pipe 20 can be constructed in various ways and made from different numbers of plastics. Epoxy, phenolic and silicone plastics have been found to be materials that have suitable properties. Epoxy and phenolic plastics can be formulated in such a way that they have flexible and deformable properties in the so-called semi-hardened state (B stage ) and after installation become practically rigid (C stage) due to the aftertreatment, due to the completion of the polyemrisation implementation. This is possible due to the use of hardeners such as amines, anhydrides or polyamides. The specific type of curing agent to be used depends on whether the copolymerization in the material of the exhaust pipe is restored by raising the temperature of the material above a predetermined temperature or by adding a chemical reactant (similar or not similar to the curing agent) into the

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ORIGINAL INSPECTED

Material de * Ä ^ puffsrclirs is started as it is further described under- ·: '^>·> Ve suitable fillers, such as asbestos, sand, fiberglass' and similar fibrous materials can be combined together with the specified plastics, so as to make the exhaust pipe give appropriate strength au. Filling agents which act in such a way that an insulation or drainage of the latent exhaust gas heat of the exhaust gas a discharged through the exhaust pipe 20 results, can also be noticed in the material of the exhaust pipe. A suitable fire protection agent, such as antimony trioxide, can also be incorporated into the material of the exhaust pipe in order to exclude the possibility of it being attacked by the hot exhaust gases.

As shown in Fig. 2, one method of manufacturing the exhaust pipe 20 is to combine a plurality of layers of material having the multi-stage hardening properties described above into a laminated body. Thus, Z may be ₀ Bc, wherein a multi-layered wall shape of the exhaust pipe 20, the radially innermost layer or tube 26 from one of the Kunsthsrzmassen described above in combination with a suitable Ieolationsmaterial as fibrous ceramic material, a.3. Clay-silica fibers are made and this material is either randomly distributed in the synthetic resin or arranged in the form of a woven fiber mat which is impregnated with the synthetic resin. Optionally, a suitable high-temperature Aebestmaterial such as amosite or crocidolite can be used as the insulation material in the inner layer 26. Such materials are superior to conventional asbestos in that they do not exhibit the fragile, flaky structure of asbestos.

In the construction of the exhaust pipe according to FIG. 2, the radially inner Layer or tube 26 surrounded by an intermediate layer 27 which preferably from a suitable mass of insulation material and

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BATH ORIGINAL

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Plastic is made, and this intermediate layer serves to the innermost layer 26 with a radially outermost Layer or cladding 28 to connect the layers 27 and 26 surrounds. The sheath or cladding 28 is preferably made from a synthetic resin compound and economical thermally conductive fibers manufactured and serves as a grass barrier for the duroh the exhaust pipe 20 removed exhaust gases. Optionally, the cover 28 may be made from an elastomeric composition such as a heat resistant rubber material which is commercially available under the name "Silastic". These Cladding 28 would then serve as a vibration barrier and cushion, as a result of which road vibrations of the exhaust pipe 20 are prevented from being transmitted to the motor vehicle, and likewise a possible damage to the exhaust pipe 20, which could result from the impact of stones and the like. On it, is prevented.

In a slightly modified embodiment of the exhaust pipes 20, instead of applying the above-described heat insulating layer around the inside of the exhaust pipe, it may be possible to use one To provide an arrangement for the rapid dissipation of the latent exhaust gas heat through the wall of the exhaust pipe 20. As shown in Fig. 4, One suitable method is to direct such exhaust heat through the wall of the exhaust pipe 20 to randomly embedded thermally conductive members inside the wall of the exhaust pipe 20 such as randomly oriented metal particles 30 made of aluminum or alumina and the like, and these particles serve to do so quickly dissipate the exhaust gas heat through the wall of the exhaust pipe 20 as the exhaust gases pass through the same.

As in FIG. 3, according to a further embodiment of the invention, the exhaust pipe 20 can be provided with a number of adjacent, radially outwardly projecting ribs or wings 32, which act in such a way that the surface of the exhaust pipe 20 is enlarged and there is a cooling effect, so that the puff -

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tube 20 is göalten at the lowest possible temperature during the passage of the hot exhaust gases through the same. It rises itself, of course, that the ribs or wings 32 in different Ways can be designed, the same both releasably along the Perimeter of the exhaust pipe 20 can be attached and itt * also can be made in one piece for the production of the exhaust pipe.

Referring to Figure 4, there is another modified one Embodiment of the exhaust pipe 20 shown, and instead of the incorporation of an insulating layer or heat dissipating layer Ribs or wings on the exhaust pipe 20, as described above, it may be possible to construct the exhaust pipe 20 in such a way that that the thickness of the wall thereof is slightly from the front end adjacent to the muffler 16 towards the rear or Outlet end of the same tapers from where the exhaust gases are adjacent to the end of the motor vehicle to the outside air. Thus, this is where the wall thickness of the exhaust pipe becomes greatest there be where the exhaust gases are at their highest temperature and the wall thickness then increases towards the rear of the Exhaust pipe 20 at a speed proportional to the cooling rate the exhaust gases from ",

As stated above, the ka ta Iy table implementation can be completed (Conversion of the plastic from the B to the C stage) des Plastic of the various types of exhaust pipe 20 described above in two generally different ways depending on of the special type of plastic used. «A process that can then be applied, when the exhaust pipe contains a plastic in the form of a thermosetting plastic, such as e.g. an epoxy resin, consists in that a predetermined additional amount of heat to that in the exhaust pipe present hardening agent is applied, whereby the

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Hardening agent from the semi-hardened B stage, in which the exhaust pipe 20 is somewhat flexible and deformable, is converted into the fully hardened C-stage in which the exhaust pipe 20 comes in handy is rigid and non-deformable. There can be heat on the exhaust pipe 20 can be applied in different ways, e.g. using a conventional blowtorch, an induction heater * or the like, but there is an extraordinarily simple, economical one and thus preferred method of applying heat to the exhaust pipe 20 in that the high temperature Exhaust gases are led back, whereby the conversion described above and the resulting stiffness of the exhaust pipe 20 is reached.

Another method of completing the catalytic polymerization reaction can be used when certain types of chemically hardening synthetic resins are present in the material of the exhaust pipe, such as epoxy resins, where a chemical hardener is applied to the outside of the exhaust pipe e.g. by means of a brush, Brushing, dipping or the like «is applied, whereby the polymerization implementation to the conclusion brewed and the exhaust pipe 20 is brought into a rigid state.

By appropriately controlling the applied heat or a suitable one chemical conversion participants on the various shapes of the exhaust pipe 20 it is thus possible to determine the extent of the rigidification regulate the plastic contained in it · So can it be possible, for example. be made when loading either of heat or a chemical reaction participant on the outside of the exhaust pipe 20 that only a hardening of the outer peripheral layer the same is effected so that only the exterior of the exhaust pipe 20 is from a practically deformable and flexible state is brought into a rigid state. This is special Value in that the inside or the inner circumference of the exhaust pipe

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rohrs remains somewhat flexible and thus as an acoustic weaker or a silencer is used to reduce the drilling resonance, so that a weakening of the exhaust gas ger from before the passage through the exhaust pipe 20 results. It can also work the other way round can be made possible to rigidize only the inner periphery of the exhaust pipe 20 by, for example, the temperature inside the Exhaust pipe 20 by means of passing high-temperature exhaust gases is increased, or by a chemical conversion participant is passed through the exhaust pipe 20 after it has been bent into the appropriate configuration. As above explained, this arrangement is particularly useful because the exterior of the exhaust pipe 20 remains somewhat flexible and deformable and thus serves as a vibration barrier and cushion. It results of course that it is possible to select a suitable plastic and hardening agent for the same in such a way that at Performing the complete hardening of the exhaust pipe 20, none or both of the inner and outer peripheral surfaces thereof slightly remain flexible or deformable.

Even if the subject matter of the invention with reference to the explained Exhaust pipe 20 has been described, however, it is not limited thereto. The basic idea according to the invention can also be applied to virtually any type of exhaust pipe, the only limitation being the physical properties of the plastic contained therein is limited.

The various embodiments of the exhaust pipe described herein 20 can be constructed in various ways. A preferred method of constructing the exhaust pipe 20 is that continuously wrapped a suitable filamentary material such as fiberglass or the like around a removable form or mandrel which creates a cylindrical or tubular body.

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is formed, which can then be impregnated with one of the synthetic resins described above to gain de «Auepuffrohrs 20. Other suitable methods aum manufacturing the exhaust pipe 20 are that with synthetic resin impregnated fibers in sprayed or introduced a suitable cylindrical shape or alternatively a suitable form in a known manner by means of dipping or spraying or calendering with a Uebea train is provided. Another method of making the exhaust pipe 20 is by continuously removing the material for the The exhaust pipe is rolled to a flat or planar state in a cylindrical shape and the adjacent edges are seamed appropriately. This particular procedure is based on Schiohtkörperformen of the exhaust pipe 20 are applicable.

A particular feature and advantage of the exhaust pipe according to the invention is that the exhaust pipe 20 is in straight pieces Can be transported and stored and this in contrast to the irregular serpentine configurations of the previous known and used exhaust pipes. Thus, an exhaust pipe 20 according to the invention can be compact and easy to use Bundles (see Fig. 6) are transported and stored. Because of de j.- The fact that the exhaust pipe 20 is practically flexible and deformable in the semi-hardened state, it is possible to determine certain To transport forms of the exhaust pipe 20 in an epiral or rolled-up state, as FIG. 5 shows. For example, a Spiral of the exhaust pipe 20 on a suitable stand 34 angeord net, so that easily preselected lengths of exhaust pipe 20 can be withdrawn and cut into sections of appropriate size. It thus follows that the previously with the storage, Transportation and the like. Costs associated with handling the exhaust pipe 20 of the present invention can be substantially reduced.

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Another inventions according to it feature ordered therein that due the production of the exhaust pipe 20 from plastic is the same compared to the disadvantageous oxidation effects caused by the corrosive Exhaust condensation, road salt, weathering and the like. Insensitive. The exhaust pipe 20 according to the invention thus has a long service life, which means that with maintenance and the Replacement related costs and inconveniences are held back.

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Claims (1)

Patent attorneys oipi.-ing. Walter Meissner BERLIN33CGrunewakO, HERBERTarRAssE 22 Fernsoreoher: 887 72 87 - Wireword: Invention Postal checking account: W. Meissner, Berlin-West Bank account! W. Meissner, Berliner Bank A.-G .. Depka Berlln-Haiensee, KurfOrstendamm ISO Herbertstrasse 22 YiLker Manufacturing Company Claims 1. Exhaust system for internal combustion engines, characterized in that the same has an exhaust pipe (20) made of plastic. 2. Exhaust system according to claim 1, characterized in that the plastic consists of a synthetic resin which cures in several stages, and the exhaust pipe (20) practically flexible and deformable in the presence of the plastic in a step and convenient is rigid and non-deformable when the plastic is present in a different stage. 3. Exhaust system according to claim 1 or 2, characterized in that the exhaust pipe (20) has a multilayer wall structure (26,27,28) having. 4. Exhaust system according to one of the preceding claims, characterized in that that one wall (27) of the exhaust pipe (20) contains an insulating material and another wall (28) of the exhaust pipe (20; has a weatherproof protective coating. 5. Aögas system according to claims 1 or 2, characterized in that that its arrangement is provided through which the heat quickly passes through the wall of the exhaust pipe (20) is discharged. 6. Exhaust system according to claim 5, characterized in that the exhaust pipe (20) randomly oriented heat-conducting elements (30) embedded in it " 7. Exhaust system according to claim 5, characterized in that the Exhaust pipe (20) a plurality of heat-conducting wings (32) along üea the outer periphery of the same arranged. " 90983 6./0466 U80626 8, exhaust system according to claims 1 or 2, characterized in that that the Auepuffrohr (20) τοη the inlet end of the same starting in Tapering towards the outlet end of the same. 9ο exhaust system according to claims 2 to 8, characterized in that the plastic from its deformable state to its rigid state when heat is applied to the synthetic resin, which cures in several stages, "can be grounded." 10. Exhaust system according to claim 9 »characterized in that the heat on the synthetic resin by means of passing hot exhaust gases is acted upon by the exhaust pipe (20). 11. Exhaust system according to claims 2 to 8, characterized in that the plastic from the flexible Zus tan: ^{1 can be converted} into the rigid state by applying a calibration agent with the synthetic resin. 12. Exhaust system according to claim 3 »characterized in that the radially innermost wall (26) is practical, rigid and the radially outermost Wall (28) is slightly deformable and acts as a vibration barrier and upholstery is used. 13. Exhaust system according to claim 3 »characterized in that one of the walls (26,27 _f 28) of the multilayer wall structure acts as a silencer. 14. Exhaust system according to one of the preceding claims, characterized in that daji the Auepuff pipe (20) is a cladding material Pi ₉ PnNv-i »c? Nvvä! H? Dipl .- '''V' · ''fl'3Γ Cn, U.-Vüiitn IU. 3 .; , V / 5 ^: 909836/0466