ES2335794T3 - EXHAUST INSTALLATION FOR INTERNAL COMBUSTION MOTORS. - Google Patents

Abstract

An exhaust silencer, especially for a turbo charged IC engine, has a small volume straight through chamber linked to a larger volume expansion chamber. The silencer has inlet and outlet (4, 5) ports and comprises a perforated tube linked to cross tubes which connect to an array of expansion chambers whose size and layout provides enhanced damping in the lower engine speeds. The design is optimized to provide progressive increase in sound with engine speed.

Description

Exhaust system for combustion engines internal

The present invention concerns a exhaust system for internal combustion engines, especially motor vehicles, according to the preamble of claim 1.

Especially in turbomotors it is important that only a small back pressure is established by means of silencer, since otherwise the turbocharger cannot work properly Another problem with turbochargers is that turbocharged engines turn out to be less noisy in the upper range of speed numbers. However, for provide the driver with a perception of speed developed it is desirable that the noise of the march increase with the engine power.

An exhaust installation according to the preamble of claim 1 is known from the document DE-A1-197 43 447. Other state relevant technique is revealed in the documents EP-A2-1 380 734 and WO-A1-2005033485.

The invention is based on the problem of indicating an escape facility of the class cited at the beginning that can use especially well for turbomotors and make possible even in turbomotors a noise in the mouth that increases with the power.

This problem is solved by means of a exhaust system with the features of the claim one.

Thanks to this installation configuration Exhaust is virtually no back pressure. Do not However, due to the large area not covered by the exhaust gas, you can get a good sound damping in the range lower speed numbers. In this way, you can guarantee, on the one hand, an optimal work of a turbocharger and, on the other, a noise in the mouth that increases with the power.

According to the invention, the two areas not covered by the exhaust gas are connected to each other, for example by middle of a tubular section. The two zones traveled by the gas of exhaust can also be advantageously linked to each other to through paths and at least one tube. The tube can extend here preferably through the two zones not covered by gas and may be provided there with a respective drilling, with which they are attached to each other at the same time both the two zones traveled by gas and the two zones not Gas tours. In both cases, the union between the two zones does not traveled by gas or between the two zones traveled by gas can be discretionary locks, in particular by means of a Exhaust gas gate arranged in the tubular section. This configuration results in tuning possibilities additional and can be used so that the noise in the mouth also increase with increasing power. To this end, the connection preferably at high speed or full speed load and open at low speed or load partial.

Through the exhaust gas gate you can close the corresponding exhaust branch at will. Through the junction with the other exhaust branch, the exhaust gas enters then in this other exhaust branch and, together with the exhaust gas existing there, circulates to its gas outlet opening of escape. This results in a cheap possibility of variation of sound damping behavior of the installation of escape, through which you can especially create a sports load feedback. The gate is closed of the exhaust gas, a high sound damping results, and the segment placed between the junction of the two exhaust branches and the Exhaust gas gate is connected in parallel to the other branch escape On the contrary, if the gas gate of exhaust, less acoustic damping is provided and, in Consequently, it is a more sporty sound.

An advantageous arrangement of a gate of Exhaust gas of this class is in the final pipe. Consequence from the junction between the two exhaust branches, the second final tube that is necessary in other cases when using a tailgate in the end pipe. This reduces the Exhaust installation costs.

An additional cost reduction is obtained when an exhaust gas gate of this class is planned only in one of the two exhaust branches. The installation of escape needs then a total of only this single gate of exhaust gas and an end pipe by exhaust branch. But nevertheless, you have to, on the one hand, being closed the gas gate of escape can achieve a high degree of comfort due to a strong acoustic damping and, when the gas damper is open Exhaust you can get a sporty sound thanks to a Small exhaust gas back pressure.

Preferably, the silencer zone run by the exhaust gas is approximately 10 to approximately 15% of the total volume. They have been able to achieve this way Especially good results.

In a usual motor vehicle motor, for an example of a six-cylinder engine, the area covered by the gas of Exhaust may have a volume of less than two liters. This zone such a small gas tour is especially advantageous for the end of use cited and has not yet materialized until now.

A reduction can be advantageously achieved additional back pressure causing the area covered by gas not present curved tubular segments. In particular, the area Gas travel is provided with a short straight tubular section. He exhaust gas can thus travel the silencer without almost any impediment.

According to another embodiment of the invention, the section Tubular presents in the gas-driven zone of the silencer a drilling and is arranged in a damping chamber, especially an absorption chamber. The absorption chamber forms a volume of exhaust gas without flow that is linked to the Exhaust gas stream by drilling the section tubular and offering additional cushioning, especially in higher frequency domains

In front of the area covered by gas can be also provided at least one branch to at least one area Not traveled by gas. Thanks to the derivation arrangement in front of the area covered by gas, the damping action of This area can effectively dampen noise produced by the shunt.

Preferably, at least one is provided. resonator chamber as an area not covered by gas. The cameras resonators can be tuned to certain frequencies to ensure, for example, good damping in the lower range of speed numbers.

According to an especially preferred embodiment, two resonator chambers are connected to the gas stream of Escape through a crosshead. This results in good chances of tuning to two different frequency domains.

However, the two resonator chambers can also be connected to each other through an intermediate wall perforated You can then perform a different tuning by means of, especially, two tubular tuning sections lying inside the two resonating chambers. Such sections Tubular tuning are also advantageous if use two resonator chambers.

It is an advantageous execution when a First absorption chamber is connected to the gas stream of Exhaust through a branch in front of the tubular section short rectum and a second absorption chamber is connected to said exhaust gas stream through a perforation practiced in the short straight tubular section. With a cost relatively small you can create good possibilities of tuning.

A compact constitution of the silencer when the zone traveled by gas and the zone not traveled by gas are arranged in a common housing. With this mode of construction can also be set easily junctions between the two zones.

The two zones covered by gas and the two zones not covered by gas can be arranged in a common housing. This leads again to a compact constitution. However it is it is also possible to provide two separate housings, being associated especially every time an area covered by gas and an area not traveled by gas to one of the two housings. The Constitution geometric and silencer arrangement are thus more flexible and can best adapt to local conditions of a vehicle car.

When the exhaust system is used according to the invention for a turbomotor, the resonator chambers are preferably tuned to the lowest noise orders of the turbomotor, for example to the third order or the sixth order in the idle range up to approximately 2100 rpm. It can achieve particularly good acoustic damping with Little decrease in the power of the turbomotor.

The exhaust system according to the invention It can also be used for diesel engines. In this case, the resonator chamber is preferably tuned to the noise peak in the lower range of revolutions of the diesel engine. In diesel engines you can also get a good acoustic damping without excessive loss of the power of the Diesel engine.

An exhaust system with a silencer according to the invention it can also be constructed without a silencer central. The total flow volume can thus be reduced in greater measure and is altogether only 1.5 to 2 liters in, for example, A six cylinder engine.

The junction between the two exhaust branches can Be permanently open. You can do without means of switching, thereby reducing costs further.

According to an embodiment of the invention, the joint between the two exhaust branches it is configured in the form of a trouser tube This is of especially simple construction and, with the exhaust gas door open, it makes possible a pressure compensation between the two exhaust branches while that, when the tailgate of the exhaust gas is closed, a overflow of the exhaust gas from one to another exhaust branch.

The junction between the two exhaust branches can be also configured in the form of a perforation in a partition common between the two exhaust branches. This union is advantageous especially when the joint is formed in a common silencer of the two escape branches.

A pant tube as a union between the two exhaust branches can also be used instead of a central silencer You get an even more constitution simplified

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An exemplary embodiment of the invention is represented in the drawing and described below. Show in respective schematic representations:

Figure 1, a plan view of a silencer of an exhaust system according to the invention,

Figure 2, a section through a part of the silencer of figure 1,

Figure 3, a plan view of another exhaust system according to the invention,

Figure 4, a plan view of a additional exhaust system according to the invention,

Figure 5, a section through a final silencer of an exhaust system according to the invention,

Figure 6, a representation, according to the figure 2, of another silencer of an exhaust system according to the invention and

Figure 7, a representation, according to figure 2, of an additional silencer of an exhaust system according to the invention.

The silencer represented in figure 1 It comprises two housings 1 and 1 'that have paths 2, 2' Exhaust gas inlet and openings 3, 3 'outlets exhaust gas In addition, the two housings 1, 1 'have paths exhaust openings 4, 4 'which are arranged a in front of another. Through the two openings 4, 4 'of gas passage of Exhaust extends an exhaust pipe 5.

Figure 2 shows the interior constitution of the silencer 1 shown on the right in figure 1, having the silencer 1 'shown on the left in figure 1 a substantially symmetrical construction of that of the other silencer. A section of the exhaust gas inlet is inserted tubular 6 which is part of the exhaust system of a automobile vehicle exhaust system. The tubular section 6 it is connected by a tubular cross section 7 with four openings passing diametrically opposite 8, 9, 10 and 11. In the first passage opening 8 is connected to the tubular exhaust section 6. The opposite passage opening 9 has a short tubular section of escape 12 with its first end 13 while the second end 14 of the short tubular section 12 flows into the outlet opening 3 exhaust gas silencer 1. In the third passage opening 10 of the tubular cross section 7 a short tubular section is inserted curved 15 and in the opposite passage opening 11 is inserted a short straight tubular section 16.

The short straight tubular section 12 leading to the exhaust outlet 3 of the muffler 1 is surrounded by a chamber 18 that is formed by a wall 17 and that It is filled with absorption material 19. The absorption chamber 18 is connected to the exhaust gas stream I through a perforation 20 performed in the short straight tubular section 12.

The short curved tubular section 15 leads to a resonator chamber 21 which is formed by the housing 1 of the silencer and an intermediate wall 22 provided in the housing 1. The intermediate wall 22 is arranged laterally with respect to the buffer chamber 18 and in approximately parallel position to short straight tubular section 12, so that the resonator chamber 21 surrounds the absorption chamber 18.

The second short straight tubular section 16 flows into the second chamber 23 formed on the other side of the intermediate wall 22, whose chamber is also made in the form of a resonating chamber The intermediate wall 22 arranged between the first resonator chamber 21 and the second resonator chamber 23 can Be of perforated construction. However, in the example of Embedded embodiment is closed.

The tubular section 5 inserted in the opening 4 of Exhaust gas passage of the silencer extends, as represents, up to the intermediate wall 22 of the housing 1 of the silencer and is preferably welded with it. It freezes thus the tubular section 5 and the complete construction of the muffler. In its segment laid through the second chamber resonator 23 the tubular section 5 is provided with a perforation 24 through which said tubular section 5 is connected to the second resonator chamber 23. As shown in Figure 1, in the second segment 25 of the tubular section 5 lying between the two parts of the silencer is arranged a gas gate 26 of escape through which the section can be closed discretionally tubular 5. The operation of the exhaust gas gate 26 is carried out with the help of media that have not been represented here, preferably depending on the engine speed. Without However, gate 26 can also be dispensed with or it can dispense with the union tube or it can be closed permanently, for example suppressing perforation 24. Without gate is a compromise between sound and comfort, and being closed or suppressed the union tube can be tuned in a way different the left side and the right side.

The silencer represented is provided especially for a two-flow exhaust system, especially of a six-cylinder V engine. Each of the two exhaust branches is connected to one of the two openings 2, 2 'exhaust gas inlet of silencer represented. How I know see in figure 4, the exhaust gas entering the opening 2 exhaust gas inlet in the direction of arrow I runs  first the tubular cross section 7 and then the tubular section short straight 12, before I leave again after the silencer through exhaust outlet 3. As recognized, the route through the silencer is very short and not it presents address variations of any kind. Back pressure  Exhaust gas is thus very small.

During the flow passage through the tubular section straight 12 the exhaust gas noise is damped by means of the absorption chamber 18. In addition, damping is performed acoustics by means of the two resonating chambers 21 and 23, the which are connected to the tubular cross section 7 and, therefore, to the exhaust gas stream I by means of the curved tubular section short 15 and the short straight tubular section 16, respectively. To everything along the two tubular sections 15 and 16, the two chambers resonators 21 and 23 are tuned to frequency domains determined from the exhaust gas noise, in a turbomotor especially to the higher orders of gas noise from escape.

Additional damping is obtained through of the union of the two parts 1, 1 'of the silencer through the tubular section 5. This additional damping is used preferably in the lower range of speed numbers or partially loaded, to which end gate 26 of the exhaust gas in the tubular section 5. On the contrary, at high revolutions or at full load the gate 26 closes of the exhaust gas, which suppresses this damping additional. A higher noise can be advantageously achieved. from the engine at higher revs, which is desirable especially in turbomotors that, otherwise, produce a noise too low at higher revs.

The volume of the area covered by gas, which is determined by the tubular cross section 7 and the tubular section short straight 12, is especially small according to the invention. In particular, it is less than 2 liters, for example 1.7 liters in the case of a six-cylinder engine. Faced with this, the volume of the area not covered by gas, which is determined by the two resonator chamber 21 and 23, as well as by the absorption chamber 18, It is relatively large. In the aforementioned six-cylinder engine it is, for example, about 15 liters. Thanks to this division of volume not traveled by gas and volume traveled by gas are gets a very small back pressure of the exhaust gas along with an acoustic damping action that, despite everything, is very good, but that is not too big for turbomotors in the higher range of speed numbers.

The exhaust installation represented in the Figure 3 comprises a first exhaust branch 27 and a second branch Exhaust 28. Both exhaust branches each have a presilenciador 29 and a final silencer 30. Among the presilenciadores 29 and the final silencers 30, the two branches Exhaust 27 and 28 are connected to each other through a pipe pants 31. In addition, the two final silencers 30 are attached with each other through a connecting tube 32.

Each of the two final silencers 30 of the two exhaust branches 27 and 28 are also provided with a pipe end 33. In the end pipe 33 of the first exhaust branch 29 is insert an exhaust gas gate 34 by means of which you can block the flow through the final tube 33 of the first branch of exhaust 27. The two final silencers 30 may be configured in the manner represented in figures 1 and 2 and described above. However, any other configuration

The operation of the exhaust system represented in figure 3 is carried out in the usual way, being able to open and close the tailgate 34 of the exhaust gas, for example, depending on the number of engine revolutions. So, the gate of the exhaust gas may be closed at low numbers of engine revolutions in order to achieve high damping acoustics. Exhaust gases from both exhaust branches 27 and 28 they can then be ejected only by the final tube 33 of the second exhaust branch 28. This results in high damping acoustics with small noise production. As a result of bass number of revolutions, then there is no back pressure Unacceptably high exhaust gas. Exhaust gas overflow  from the first closed exhaust branch 27 to the second exhaust branch performed here through the trouser tube 31. Also, being open the connecting tube 32, an overflow can also take place through East. Depending on the circumstances, a more or less large segment of the first exhaust branch 27 is then connected in parallel with the second exhaust branch 28.

The gate 34 of the gas being opened Exhaust, the exhaust can escape through the two end pipes 33. Exhaust gas streams from the exhaust branches first and second 27, 28 are then widely separated one of other. Through the pant tube 31 only one pressure compensation In this state it is a minor acoustic damping with a corresponding back pressure smaller and a correspondingly higher noise production. Do not However, this is desirable as charge feedback.

The exhaust installation represented in the Figure 4 largely coincides with that represented in Figure 3. Instead of the pant tube 31, only one intermediate silencer 35 between the presillers 29 and the final silencers 30. This intermediate silencer is common to both exhaust branches 27 and 28 and presents a union between the two exhaust branches, for example a perforated wall. He operation of this exhaust installation also coincides with that of the installation of figure 3.

The final silencer shown in Figure 5 It is conceived as a common silencer with two exhaust branches of an exhaust installation. It comprises a housing 36 in which a pant tube 37 is arranged. Two ends of the pant tube 37 form intake tubes 38 to which the escape branches. The other two ends 39 of the pant tube 37 they are connected with two discharge tubes 40. These are in turn joined with two end tubes 41.

In a final tube 41 a gate is inserted 42 of exhaust gas through which the flow to through this final tube 41. This is the same function as in the exhaust installations of figures 3 and 4. Being closed the tailgate 42 of the exhaust gas exits through the other end pipe 41 the Exhaust gas from both exhaust branches, reaching the flow of exhaust gas from the blocked branch to the other exhaust branch through of the trouser tube 37. A high is obtained again acoustic damping with corresponding comfort. For him Otherwise, the exhaust gas door 42 is open exhaust gases circulate through both end tubes 41, having place only a pressure compensation between the two branches Exhaust through the pant tube 37.

Otherwise, the final silencer may be conceived in the known way in regard to its internal constitution, especially as represented, with absorption chambers 43, 44 and a resonator chamber 45, as well as a resonator tube 46. Chambers 43, 44 and 45 are separated one of another by intermediate walls 47. The discharge tubes 40 and the tube pants 37 are connected to the absorption chambers 43 and 44 a through perforations 48.

The variant represented in Figure 6 matches widely with the variant of figure 2. However, to Unlike this, the short curved tubular section has been suppressed 15 and the tubular section 16 is connected with the tube 5. In the area of the chamber 23, which is configured here as an absorption chamber, the union tube 5 has a perforation 49. The absorption chamber 23 is thus connected with the corresponding chamber of the second exhaust system silencer.

The variant represented in Figure 7 matches again to a large degree with the variant of figure 6. Without However, unlike this, camera 21 is configured as an absorption chamber and wall 17 has been suppressed, so that here only two cameras 21 and 23 not covered by gas. The silencer of Figure 7 is especially used for right side of the exhaust system and does not have a exhaust gas damper while the silencer in the figure 6 is preferably used for the left side of the exhaust system and is provided with a gas gate escape.

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List of reference symbols

one

First silencer housing

one'

Second silencer housing

2

Exhaust gas inlet opening 1

2'

Exhaust gas inlet opening of one'

3

Exhaust gas outlet opening of 1

3'

1 'exhaust gas outlet opening

4

Exhaust gas passage opening 1

4'

1 'exhaust gas passage opening

5

Tubular section

6

Tubular section

7

Tubular cross section

8

Exhaust gas inlet opening

9

Exhaust gas inlet opening

10

Exhaust gas inlet opening

eleven

Exhaust gas inlet opening

12

Short straight tubular section

13

First end of 12

14

Second end of 12

fifteen

Short curved tubular section

16

Short straight tubular section

17

Wall

18

Absorption chamber

19

Absorption material

twenty

Drilling

twenty-one

First resonator chamber

22

Intermediate wall

2. 3

Second resonator chamber

24

Drilling

25

5 segment

26

Exhaust gas gate

27

First exhaust branch

28

2nd exhaust branch

29

Presilenciador

30

Final muffler

31

Pant tube

32

Union tube

33

End tube

3. 4

Exhaust gas gate

35

Intermediate silencer

36

Case

37

Pant tube

38

Intake

39

Discharge end of 37

40

Discharge tube

41

End tube

42

Exhaust gas gate

43

Absorption chamber

44

Absorption chamber

Four. Five

Resonator chamber

46

Resonator tube

47

Intermediate wall

48

Drilling

49

Drilling

fifty

Derivation

I

Gas stream direction of escape

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Claims (22)

1. Exhaust installation for internal combustion engines, especially motor vehicles, with two exhaust branches (27, 28) especially associated with two groups of cylinders of an engine, each with a silencer (1, 1 ' ), especially an additional silencer, with an exhaust gas inlet opening (2, 2 '), an exhaust gas outlet opening (3, 3'), an area (7, 12) covered by the gas from Exhaust and an area (18, 21, 23) not covered by the exhaust gas, an exhaust gas gate (34, 42) being provided in a gas-driven area of one of the two exhaust branches (27, 28 ), whereby said exhaust branch can be closed, also presenting the two exhaust branches (27, 28), upstream of the tailgate (34, 42) of exhaust gas, at least one junction (5, 31, 32, 35, 37) between them that it can be traversed by gas and that it is open at least when the tailgate (34, 42) of exhaust gas is closed, and when or, in addition, the zone (7, 12) of the silencers (1, 1 ') traveled by the exhaust gas which is clearly smaller than the zone (18, 21, 23) not covered by the exhaust gas, characterized in that the Two zones (18, 21, 23) not covered by gas are connected to each other. 2. Exhaust installation according to claim 1, characterized in that the exhaust gas gate (34, 42) is arranged in the final pipe (33, 41) and because the corresponding exhaust branch (27) has only this final pipe ( 33, 41). 3. Exhaust installation according to claim 1 or 2, characterized in that the joint (31, 35, 37) is permanently open and / or because the joint (31, 37) is configured in the form of a pant tube. 4. Exhaust installation according to any one of claims 1 to 3, characterized in that the joint is configured as a perforation in a common partition between the two exhaust branches (27, 28), the pant tube (31) being preferably installed in instead of an intermediate silencer or preferably the pants tube (37) being installed in a silencer, especially a final silencer. 5. Installation of exhaust gas according to any of the preceding claims, characterized in that the zone (7, 12) of the silencer covered by the exhaust gas represents approximately 10 to approximately 15% of the total volume of the silencer. 6. Exhaust system according to any of the preceding claims, characterized in that the area (7, 12) covered by the exhaust gas has a volume of less than 2 liters. 7. Exhaust installation according to any of the preceding claims, characterized in that the gas-driven zone (7, 12) does not have curved tubular segments. 8. Exhaust installation according to any of the preceding claims, characterized in that the gas-driven zone (7, 12) has a short straight tubular section (12), the short straight tubular section (12) preferably having a perforation (20) in the muffler zone covered by gas and said tubular section being arranged in a damping chamber (18), especially an absorption chamber. 9. Exhaust installation according to any of the preceding claims, characterized in that at least one branch (7, 50) is provided in front of the short straight tubular section (12, 50) towards at least one area (21, 23) not covered by gas, being preferably a first absorption chamber (23) connected in front of the short straight tubular section (12) through a branch (50) and a second resonator chamber (18) being preferably connected to the exhaust gas stream through a perforation (20) practiced in the short straight tubular section (12). 10. Exhaust installation according to any of the preceding claims, characterized in that at least one resonator chamber (21, 23) is provided as a non-gas-driven zone. 11. Exhaust installation according to any of the preceding claims, characterized in that two resonator chambers (21, 23) are connected to the exhaust gas stream (I) through a cross-sectioned tubular section (7). 12. Exhaust installation according to any of the preceding claims, characterized in that two resonator chambers (21, 23) with an intermediate wall (22) perforated or unperforated are provided. 13. Exhaust installation according to any of the preceding claims, characterized in that at least one resonator chamber (21, 23) is provided which is connected to the exhaust gas stream through a tubular tuning section (15, 16). 14. Exhaust installation according to any of the preceding claims, characterized in that the zone (7, 12) covered by gas and the area (18, 21, 23) not covered by gas are arranged in a common housing (1). 15. Exhaust installation according to any of the preceding claims, characterized in that the two zones (18, 21, 23) not covered by gas are connected to each other through a tubular section (5).

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16. Exhaust system according to any one of the preceding claims, characterized in that the two zones (7, 12) covered by gas are connected to each other through different paths (50) and at least one tumbo (5), extending the section tubular (5) preferably through the two zones (23, 23 ') not covered by gas and being provided there with a respective perforation (49). 17. Exhaust installation according to any of the preceding claims, characterized in that the joint (5) can be closed at its discretion, in particular by means of an exhaust gas gate (26) disposed in the tubular section (5), the joint being (5) preferably closed at high speed or full load and open at low speed or partial load. 18. Exhaust installation according to any of the preceding claims, characterized in that all the zones (18, 21, 23) are arranged in a common housing or because two separate housings (1, 1 ') are provided. 19. Exhaust system according to any of the preceding claims, characterized in that it is used for a turbomotor, the resonator chambers (21, 23) being tuned preferably at the higher orders of the noise of the turbomotor exhaust gas. 20. Exhaust system according to any one of claims 1 to 18, characterized in that it is used for a diesel engine, the resonating chambers (21, 23) being preferably tuned to the peak of noise in the lower range of revolutions of the diesel engine. 21. Exhaust installation according to any one of the preceding claims, characterized in that tuning is performed so that the noise of the exhaust gas increases substantially continuously throughout the range of revolutions. 22. Exhaust system according to any of the preceding claims, characterized in that an intermediate silencer is not provided.