JP4866440B2 - Silencer - Google Patents

Description

  The present invention relates to a silencer connected to an exhaust system of an engine for vehicles or the like, and more particularly to a silencer that enhances a silencing effect due to interference of exhaust gas.

  Conventionally, in a silencer provided in an exhaust system of a vehicle engine, exhaust gas flowing through the first inner pipe 26L and the second inner pipe 26R is merged into an exhaust interference chamber 25 provided in the shell 11. A device that reduces exhaust noise by interfering with each other is known (see Patent Document 1 below).

Japanese Patent No. 3319956

  However, what is disclosed in Patent Document 1 is that an exhaust gas flowing through the first inner pipe 26L and the second inner pipe 26R is partly disposed in the exhaust interference chamber 25 provided in the middle of a passage through which the exhaust gas flows. Therefore, there is a problem that the amount of exhaust gas related to the interference is small and a sufficient interference effect due to the interference of the exhaust gas cannot be obtained.

  The present invention has been made in view of such a situation, and by causing the exhaust gas guided from the engine to the first exhaust gas introduction pipe and the second exhaust gas introduction pipe to interfere with each other in the expansion chamber, noise reduction due to the interference is achieved. An object is to provide a novel silencer that greatly improves the effect.

In order to achieve the above object, the invention according to claim 1 is configured to guide exhaust gas from the engine to the expansion chamber in the silencer body by the first exhaust gas introduction pipe and the second exhaust gas introduction pipe, In the silencer, wherein exhaust gas in the expansion chamber is discharged out of the silencer body by at least one exhaust gas discharge pipe.
The first exhaust gas introduction pipe and the second exhaust gas introduction pipe are connected through the middle portion of the shell between the left and right end walls of the silencer body, and the first exhaust gas introduction pipe and the second exhaust gas introduction are connected. The pipe is branched into one branch pipe and the other branch pipe in the silencer body, and the downstream end opening of one of the branch pipes is directly opposed with a space in the center of the expansion chamber. In addition, the downstream openings of the other branch pipes are respectively communicated to the outside through open / close valves that open when the engine reaches the high speed operation range .

According to the invention of the claims sections wherein the amount of exhaust gas involved in the interference remarkably increased, interference of the exhaust gas increases. As a result, the silencing effect due to the interference of exhaust gas can be enhanced. Also, since the exhaust gas after being interference uniformly expanded in the expansion chamber can be enhanced silencing effect due to the expansion of the exhaust gas.

Overall plan view of an exhaust system of a vehicle engine equipped with the silencer of the present invention Broken perspective view of the silencer shown in the arrow 2 in FIG. Sectional view of arrow 3 in FIG. Sectional view along line 4-4 in FIG. Enlarged sectional view taken along line 5-5 in FIG. Sectional drawing which follows the 6-6 line of FIG.

  Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

  In this embodiment, the silencer of the present invention is applied to an exhaust system of a V-type engine for a vehicle. In the following description, front and rear, left and right, and top and bottom are based on the forward direction of the vehicle.

  In FIG. 1, the vehicular engine generally indicated by the symbol E is a V-type multi-cylinder engine, and includes left and right banks BL and BR that form a pair, and the exhaust manifolds of these banks BL and BR include The first exhaust pipe P1 and the second exhaust pipe P2 are connected to each other. The first and second exhaust pipes P1 and P2 are separated from each other in the width direction of the vehicle body F and extend in the front-rear direction. The exhaust pipes P1 and P2 are primary in order from the upstream side to the downstream side. The catalyst CA1, the secondary catalyst CA2, and the auxiliary silencer (prechamber) PC are connected in series. The downstream ends of the first and second exhaust pipes P1, P2 are connected in parallel to the silencer M according to the present invention via joints J, J. The auxiliary silencers PC and PC are connected to each other to regulate the distance between them, and the downstream side of the auxiliary silencers PC and PC of the first and second exhaust pipes P1 and P2 is an elastic support member. The silencer M is suspended and supported by the vehicle body F via the other elastic support members S2 and S2 and is suspended and supported by the vehicle body F via S1 and S1.

  The exhaust gas discharged from the operation of the engine E is purified by the primary and secondary catalytic converters CA1 and CA2 to remove harmful components such as HC, CO and NOx, and then the auxiliary silencer. After being silently silenced through the PC, the sound is silenced by the silencer M and discharged to the outside.

  Next, the configuration of the silencer M according to the present invention will be described in detail with reference to FIGS.

  The silencer M is disposed in such a direction that its longitudinal center axis LL crosses the longitudinal direction of the vehicle body F, and the silencer body 1 that forms the main part of the silencer M and the exhaust gas from the engine E are silenced. A pair of left and right first exhaust gas introduction pipes 2L and second exhaust gas introduction pipes 2R that lead to the main body 1, and a pair of left and right exhaust pipes that exhaust the exhaust gases in the expansion chambers 20, 21, and 21 in the silencer body 1 to the outside. The exhaust gas discharge pipes 5 and 5 are provided.

  The silencer body 1 constitutes the housing of the silencer M, and includes a cylindrical shell 10 whose left and right end faces are open, a left end wall 11 that is airtightly fixed to the left opening end of the shell 10, and the shell. A right end wall 12 that is airtightly fixed to the right opening end of the right side wall and a cylindrical shape that is more hermetically sealed, and a sound deadening chamber is formed therein. The silencer body 1 is supported by the vehicle body F with its longitudinal center axis LL directed in the left-right direction.

  A pair of left and right inner separators 13, 13 each having a plurality of small holes 15 made of punching holes are fixed substantially parallel to the left and right end walls 11, 12 at the central portion in the longitudinal direction of the inner surface of the silencer body 1. An expansion chamber 20 is formed between the pair of inner separators 13 and 13. A pair of left and right outer separators 14 and 14 are fixed to the left and right end walls 11 and 12 in the longitudinal direction of the inner surface of the silencer body 1 so as to be substantially parallel to the left and right end walls 11 and 12. Expansion chambers 21 and 21 are formed between the inner separators 13 and 13 and the outer separators 14 and 14, and are formed between the outer separator 14 and the left end wall 11 and between the outer separator 14 and the right end wall 12. The resonance chambers 21R are respectively formed.

  A pair of left and right first exhaust gas introduction pipes 2 </ b> L and a second exhaust gas introduction pipe 2 </ b> R are provided in the shell 10 so as to be biased closer to the left and right end walls 11, 12 than the longitudinal center of the sound deadening chamber body 1. Each is through-connected. The upstream end of the first exhaust gas introduction pipe 2L and the upstream end of the second exhaust gas introduction pipe 2R are connected to the downstream end of the first exhaust pipe P1 and the second exhaust pipe P2 outside the silencer body 1. The first exhaust gas introduction pipe 2L and the second exhaust gas introduction pipe 2R are connected to the downstream ends via joints J and J, respectively, in the expansion chambers 21 and 21 of the silencer main body 1. One branch pipe 3, 3 and the other branch pipe 4, 4 are bifurcated. One branch pipe 3, 3 extends toward the center in the silencer main body 1, and its downstream end is penetrated and supported by the central part of the inner separators 13, 13, and the central part of the expansion chamber 20, That is, the silencer body 1 is opened on the longitudinal center axis LL. As shown in FIGS. 2 and 3, the downstream end openings of the pair of left and right one branch pipes 3 and 3 are arranged to face each other with a space in the central portion in the expansion chamber 21. On the other hand, the pair of left and right other branch pipes 4, 4 extend in the silencer body 1 toward the left and right end walls 11, 12, respectively, and their downstream ends are biased in the radial direction of the outer separators 14, 14. And is communicated with an inlet of an on-off valve V described later.

  A pair of left and right exhausts penetrating the resonance chamber 21R is provided between the pair of left and right outer separators 14 and 14 and the left and right end walls 11 and 12 at positions that are separated from the on-off valve V and are radially offset. Gas exhaust pipes 5 and 5 are respectively supported along the axial direction of the silencer body 1, and the upstream ends of the exhaust gas exhaust pipes 5 and 5 are expanded in a divergent shape so that the inner and outer separators 13, Opened into the expansion chambers 21 and 21 between the 13, 14, and 14 and the downstream ends thereof are connected to tail pipes 23 and 23 that open to the outside, respectively.

  A pair of left and right outer separators 14 and 14 are supported by a pair of communicating pipes 16 and 17, respectively. The communicating pipes 16 and 17 have an expansion chamber 21 between the inner and outer separators 13 and 14, and a resonance chamber 21R. And communicate with each other.

  The pair of left and right inner separators 13 and 13 and the pair of left and right outer separators 14 and 14 are respectively connected by a plurality of (three) connecting rods 18 that are fixed to their outer peripheral portions with a circumferential interval therebetween. Yes.

  As shown in FIG. 3, the on-off valve V includes a housing 30 supported between outer separators 14 and 14 and left and right end walls 11 and 12, a valve body 31 provided in the housing 30, and a valve body. And a valve spring 32 formed of a coil spring that elastically biases 31 to a closed position. The opening / closing valve V is directly connected to the downstream end opening of the other branch pipe 4, and the outlet is connected to the tail pipe 24 that opens to the outside via the exhaust passage 33. When the exhaust gas pressure in the first and second exhaust gas introduction pipes 2L, 2R is equal to or lower than a predetermined value, the valve body 31 closes the downstream opening of the other branch pipe 4 by the elastic force of the valve spring 32. When the other branch pipe 4 and the outside are maintained in a shut-off state, and when the exhaust gas pressure in the first and second exhaust gas introduction pipes 2L and 2R exceeds a predetermined value, the valve body 31 is closed. Is opened against the elastic force of the valve spring 32, and the downstream end opening of the other branch pipe 4 is opened to the outside through the exhaust passage 33 without communicating with the resonance chamber 21R.

  In FIG. 1, reference numeral 25 denotes a side branch (resonance silencer) 25 connected in the middle of the tail pipe 23.

  Next, the operation of this embodiment will be described.

  Now, according to the operation of the V-type engine E, the exhaust gas discharged from the left and right banks BL, BR flows through the first exhaust pipe P1 and the second exhaust pipe P2, and passes through the primary and secondary catalysts CA1, CA2, respectively. After flowing and purifying harmful components such as Nx, CO, and HC, they enter the prechambers PC and PC, where they are primarily silenced, and then pass through the first exhaust gas introduction pipe 2L and the second exhaust gas introduction pipe 2R. It is guided to the silencer M according to the present invention, and after being silenced as described later, it is discharged to the outside.

  In the low speed operation region including the idling operation and the start operation of the engine E, the combustion pressure of the engine E is low and the pressure of the exhaust gas discharged from the engine E is also low. Therefore, the first exhaust gas introduction pipe 2L and the second exhaust gas Since the pressure of the exhaust gas flowing into the silencer body 1 from the introduction pipe 2R is weaker than the resilience of the valve spring 32 of the on-off valve V, the valve body 32 of the on-off valve V is as shown by the solid line position in FIG. The closed state is maintained. Therefore, the exhaust gas introduced into the first and second exhaust gas introduction pipes 2L and 2R expands through the one of the left and right branch pipes 3 and 3 as shown by the solid line arrow a in FIG. The left and right inner separators 13 and 13 pass through the small holes 15 and then divert to the left and right expansion chambers 21 and 21. Through the exhaust gas discharge pipes 5 and 5.

  In this process, the exhaust sound of the exhaust gas is effectively silenced by the silencing effect due to the expansion in the expansion chambers 20, 21, and 21 and the silencing effect due to the resonance in the resonance chambers 21R and 21R.

  By the way, in the low-speed operation region of the engine E, the exhaust gas introduced into the first and second exhaust gas introduction pipes 2L and 2R passes through the one of the left and right branch pipes 3 and 3, and the expansion chamber 20 Since the amount of exhaust gas flowing into the expansion chamber 20 increases, the downstream end openings of the left and right branch pipes 3 and 3 face each other in the expansion chamber 20. Therefore, the amount of exhaust gas involved in interference increases as much as possible, and the amount of interference of exhaust gas also increases. As a result, the silencing effect based on the interference of exhaust gas is greatly enhanced.

  In particular, as shown in FIGS. 2 and 3, the downstream end opening of one branch pipe 3 of the first exhaust gas introduction pipe 2L and the downstream of one branch pipe 3 of the second exhaust gas introduction pipe 2R. The side end openings are on the longitudinal center axis LL of the silencer M main body, and are opposed to each other with a space at the center of the expansion chamber 20, so that the exhaust gas after interference is made. It can be expanded uniformly in the expansion chamber 20, and the silencing effect due to the expansion of the exhaust gas can be enhanced.

  On the other hand, when the combustion of the engine E is in a complete explosion state and reaches the high speed operation region, the combustion pressure increases, and the pressure of the exhaust gas exhausted therefrom increases, so the first exhaust gas introduction pipe 2L The pressure of the exhaust gas flowing into the second exhaust gas introduction pipe 2R also increases, and the pressure of the exhaust gas flowing into the other branch pipes 4, 4 is greater than the spring force of the valve spring 32 of the on-off valve V. The valve body 31 of the on-off valve V is opened as shown by the chain line in FIG. Therefore, most of the exhaust gas flowing into the first exhaust gas introduction pipe 2L and the second exhaust gas introduction pipe 2R does not pass through the expansion chambers 20, 21, 21, and the other branch pipes 4, 4 The exhaust gas is directly discharged to the outside through the on-off valve V and the exhaust passage 33, and the flow resistance of the exhaust gas is greatly reduced.

  The first and second exhaust gas introduction pipes 2L and 2R pass through the shell 10 between the left and right end walls 11 and 12, and are connected to the silencer main body 1. The exhaust gas introduction pipes 2L and 2R Since the other branch pipes 4 and 4 on the side where the on-off valves V and V are provided open directly from the left and right end walls 11 and 12 to the outside of the silencer body 1, when the on-off valves V and V are opened, The pipe length until the exhaust gas in the first and second exhaust gas introduction pipes 2L and 2R reaches the external opening of the silencer body 1 via the other branch pipes 4 and 4 is shortened, and the exhaust gas flow resistance is reduced. Furthermore, by reducing the flow resistance to the external opening when the on-off valves V, V are opened, the expansion chambers 20, 21, 21 can be opened when the on-off valves V, V are opened. Directly discharged from the external opening through the other branch pipes 4 and 4 without going through The amount of exhaust gas generated increases, and the amount of exhaust gas flowing into the expansion chambers 20, 21, and 21 via the one branch pipes 3, 3 that do not have the on-off valves V, V decreases. An increase in distribution resistance due to discharge via 20, 21, 21 can be greatly reduced. As a result, as a whole, the flow resistance of the exhaust gas flowing through the silencer body 1 can be reduced as much as possible, thereby enhancing the output improvement effect of the engine.

  As mentioned above, although the Example of this invention was described, this invention is not limited to the Example, A various Example is possible within the scope of the present invention.

  For example, in the above-described embodiment, the case where the silencer M of the present invention is implemented in the exhaust system of the V-type engine E for vehicles has been described. It is.

  In the above embodiment, the interference exhaust gas in the expansion chambers 20 and 21 is discharged to the outside through the pair of left and right exhaust gas discharge pipes 5 and 5. However, the interference exhaust gas in the expansion chambers 20 and 21 is discharged. The exhaust gas may be discharged to the outside through one or three or more exhaust gas discharge pipes.

DESCRIPTION OF SYMBOLS 1 ... Silencer main body 2L ... 1st exhaust gas introduction pipe 2R ... 2nd exhaust gas introduction pipe 5 ... Exhaust gas exhaust pipe
10 ... Shell
11 ... Left end wall
12 .... Right end wall 20 ... Expansion chamber 21 ... Expansion chamber E ... Engine V ... Open / close valve

Claims (1)

The exhaust gas from the engine (E) is guided to the expansion chamber (20, 21) in the silencer body (1) by the first exhaust gas introduction pipe (2L) and the second exhaust gas introduction pipe (2R). In the silencer, the exhaust gas in the expansion chamber (20, 21) is discharged out of the silencer body (1) by at least one exhaust gas discharge pipe (5).
The first exhaust gas introduction pipe (2L) and the second exhaust gas introduction pipe (2R) penetrate through the middle part of the shell (10) between the left and right end walls (11, 12) of the silencer body (1). The first exhaust gas introduction pipe (2L) and the second exhaust gas introduction pipe (2R) are connected to one branch pipe (3) and the other branch pipe (4) in the silencer body (1). The downstream end openings of one of the branch pipes (3) are directly opposed to each other with a space in the center of the expansion chamber (20), and the other branch pipe (4 The downstream silencer is connected to the outside through an on-off valve (V) that opens when the engine (E) reaches the high speed operation range .

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