DE2719634A1 - Internal combustion engine exhaust system and silencer - uses tubes with multiple bores to cool exhaust gas - Google Patents

Abstract

A silencer forming part of the exhaust system of an internal combustion engine consists of two concentric tubes (51, 52). These tubes are joined by radial walls (55) which extend longitudinally so that the annular space between the tubes is divided into a number of separate compartments (5). A cooling fluid flows in these compartments (5) in the opposite direction to the flow of gas in the central bore (50). The outer wall of the outer tube (52) has a number of radial fins (56) which also extend longitudinally. These fins help to dissipate the heat which has been transferred to the cooling medium by convection and radiation.

Description

Additional application to the patent application v.29.4.77 (own symbol:

lei S 772; File number not yet issued) with the designation aluminum cables with a simple hollow chamber jacket, especially in the case of mufflers of internal combustion engines ".

Designation of the additional registration: "Thermal exhaust gas routing addendum 1" Description In the main application a system of thermal exhaust gas experience is described that the area of application of aluminum cables despite the low heat resistance limit this material is significantly expanded in the exhaust systems of internal combustion engines. The basic structural element consists in the formation of a raw chamber annulus, which is divided into various elongated gas ducts by ribs. The structural arrangement of this basic element, from which the thermal The first advantage is that the outer wall of the hollow chamber jacket radiates in its predominant extent into the free atmosphere, secondly in it that the aluminum body in connection with the ribs, which its gas guide route divide it into different partial flow guides, one in counterflow Gas guide line contains which, and this is the third characteristic, of the amount of exhaust gas, which passed through the hollow spaces, is only then flushed after it has been in an intermediate zone functionally located between the two gas routing groups has experienced further heat loss.

This heat loss can be achieved in any way in the claim 1 of the main application, the following examples were given: Radiation to the free Atmosphere, heat exchange to a purging and heat-absorbing medial from the other side. The intermediate zone is called a "functional" one because it is not spatially, to be understood as lying between the two aluminum-limited gas routing groups is; it lies, see the schematic drawings reproduced again in this additional application Figures 1 and 3, which correspond to the schematic drawings of the main application, in the Usually outside the aluminum body, as can be seen in room 7 of FIG. The exhaust gas flows from the partial flow channels 9 of the cavity jacket radiates into the intermediate zone 7, which can be made of a different material with its wall 5 into the free atmosphere, and then enters the other gas guide line (10), which has a common aluminum wall with the lines 9.

In accordance with the features of claim 1 of the main application are related to the structural shape of the aluminum-manufactured basic element two special design options explained by this additional application. she can be seen from FIGS. 5 and 2. Figure 5 shows a base chamber annulus, delimited by the walls 15 and 24, its partial flow subdivision into the various elongated exhaust gas ducting spaces 9 are not made by ribs made of solid material, but by usually tubular ribs, so that with their further cavities (10) a further gas routing group can be formed. The one described below Figure 4 shows an embodiment. In this case it can even be dispensed with are to produce the wall 24 (inner wall) also from aluminum, so that the pure aluminum body both the hollow chamber annulus as the second counter-rotating Brings gas guide group to the emergence of the wall 24 part of a Rohres is that with the structure, consisting of the outer jacket 15 and the cast respectively.

pressed pipe ribs 10, no fixed connection in the sense has that it would form a unitary extruded body with these. FIG. 2 shows a hollow chamber annulus which corresponds in principle to FIG and only has the additional feature that on its inner wall 8 more Ribs 3 are cast; this construction gives in a manner similar to the figure 5 the further combination advantage, through an inserted tube 13 with the help of it form-fitting wall 24 a further, namely inner hollow chamber annulus to achieve with partial flow distribution in the simplest way. Figure 6 shows this an application example as an overall construction.

Figures 4 and 6 represent exhaust systems, namely sound-absorbing, They show how, for example, motorcycle mufflers for high-performance designs by Two-stroke engines (Figure 4) and four-stroke engines (Figure 6) using such extruded Hollow chamber gas ducts, which are mainly made of aluminum, related with tried and tested high-performance elements with an optimal soundproofing effect can be provided.

Figure 4 shows a two-stroke engine exhaust system, the exhaust gas from a cylindrical pipe part 1 in a relaxation volume 2 passes over, which from a downstream opening cone, a cylindrical part and a downstream part there is a narrowing cone, which is closed by a Dructwelle throwback wall 26 and the exhaust gas is discharged through the side wall hole group 18 into the space 17. This Room 17 corresponds to claim 2 of the main application. The exhaust gas comes out of it through the 6: 11, which correspond to claim 3 of the main application, into one Aluminum bodies according to FIG. 5, namely in the substream group 9. Exiting there a further cooling takes place in the thermal intermediate zone 7 and then in the countercurrent return through the tubular ribs 10 and their extension tubes 16 in the final part of the system, an acoustic chain ladder, ending in the end pipe 12. The entire The system can be dismantled after the nut of the retaining bolt 25 is loosened: after removal the part, usually made of sheet steel, with volumes 17 and 23 is also the aluminum body is removable. As described above, it is possible to use the aluminum body, which corresponds to the section in FIG. 5 without producing the wall 24, since the pipe ribs 10 by resting on the cylindrical sheet metal wall of the space 2, the shape of the hollow chamber annular space with partial flow division without affecting the aluminum partition would require. Acoustically, this construction has the extraordinary advantage that through the opposing partial flow groups created excellent sound-absorbing components and the outer jacket has become completely free of structure-borne noise, i.e. without the annoying tin tone.

Figure 6 shows a four-stroke engine high-performance system with so-called. Long pipe tuning. Since the final part with the volumes 17 and 23 has a length of 100 up to 150 mm, a long tube is 1/13 up to about the center of the wheel Realizable rear wheel and thus this four-stroke performance element also within of the limitations imposed by the length of the two-wheeler. Of the interrupted drawn aluminum structure is without this a price problem produced, to be extended almost at will and thereby an ideal effect Coordinate sound absorption part. Its section can be seen in FIG. Through use of the long pipe power tuning pipe 1/13 is created, this i.e. its jacket wall Surrounding 24, a double pile chamber annulus with double partial flow group formation (10 and 9). As in FIG. 4, the thermal intermediate zone is the space 7 at the front. This system can be fully dismantled by loosening the nut of the bolt 25. One a special thermal variant is given in the construction according to FIG. 6, that on the baffle wall of the de-icing zone 2, i.e. exactly opposite the exhaust gas outlet the long tube 13, a special type of heat routing is provided: the room At this position 20 is adjacent to the space 20, which thereby enables a fresh air throughput causes the air entering at the openings 19 to pass through an air ejector continuously is sucked off, for which the amount of exhaust gas entering the end pipe is the driving force Medium represents (12). The air ejector tube 21 protrudes through an exhaust gas annulus forming, in the exhaust pipe 12 briefly in its upstream zone. In this way there is a constant extraction of heat from zone 2 and a removal of this Amount of heat on an ideal short-circuit path directly into the silencer outlet. The extent to which this heat relief occurs depends purely on the design. About this a schematic drawing naturally does not provide any information. Due to the large heat exchange surface between the rooms 2 and 20, the conditions for this are favorable and effective further measures can be increased. That this measure requires the use of aluminum substantially supported, is obvious.

L e r s e i t e

Claims (5)

Claims Thermal exhaust gas delivery according to one of Claims 1 to 3 of the main application with the aluminum-manufactured component of a hollow chamber annulus, that in mufflers or Xtililstrekken of the exhaust systems of internal combustion engines is integrated and by ribs in different elongated, in particular two partial flow groups running in a countercurrent arrangement are subdivided with the feature, that the outer wall of the Hohlkammermanteis in its predominant extent in the emits free atmosphere, and the further feature that the amount of exhaust gas, which the first partial flow channels (9) leaves before entering the second partial flow channel group passes a thermal intermediate zone (7) with aluminum wall deposit (10), in which it suffers further heat loss, characterized in that the partial flow-forming ribs of the hollow-chamber ring rail are not made of solid material are, but have continuous cavities in the longitudinal extension and thereby are able to form a separately usable Teílstrongroupre, which the other sub-stream groups depending on the construction context, a distinguishable one and form exhaust gas passages that cannot be mixed with them. 2. Thermal exhaust gas routing according to the previous claim, characterized in that that the aluminum body as a cast or extruded unit consists only of the outer Sole chamber jacket (Figure 5 number 15) and the tubular ribs (10) consists. 3. Thermal exhaust gas routing according to one of the claims of the main application or one of the two previous claims characterized in that also on the Inner wall (8) of the aluminum body rib-like and inwardly directed bulges (3) made of solid or hollow material are provided, which form-fit on elner Service (13/24) are applied that are either part of the pre-cast or cast body its outer wall (24) is or belongs to a component and to that extent from something else Production process results. 4. Thermal exhaust gas routing according to claim 2 of the main application an exhaust gas inlet zone, which is located between the engine outlet or the exhaust pipe (or manifold) connected there and the inlet in the first partial flow group completely or partially provided with aluminum walls is located, characterized in that this exhaust gas inlet zone heat exchange wall to a fresh air throughput zone (20) integrated into the entire body. 5. Thermal exhaust gas routing according to the previous claim, characterized in that that the fresh air throughput is operated by an ejector, which is in the upstream Part of the outlet pipe (12) protrudes (21).