JP2010255518A - Muffler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance an engine output improving effect by reducing the flow resistance of exhaust gas flowing in a muffler body in a muffler muffling exhaust gas from an engine. <P>SOLUTION: Exhaust gas introducing pipes 2L, 2R are connected to the muffler body 1 through the shell 10 of the muffler body between a pair of end walls 11, 12 of the muffler body 1, and each of exhaust gas introducing pipes is branched into one branch pipe 3 for introducing exhaust gas into expansion chambers 20, 21 and the other branch pipe 4 opened to the outside of the muffler body through the inside of the muffler body 1. By the one branch pipe 3, the exhaust gas is discharged to the outside of the muffler body 1 through the expansion chambers 20, 21, and by the other branch pipe 4, the exhaust gas is directly discharged to the outside of the muffler body 1 not through the expansion chambers 20, 21 when an operating valve V is opened. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an exhaust silencer connected to an exhaust system of an engine for a vehicle or the like, and more particularly, to an exhaust silencer that increases the silencing effect by reducing the flow resistance of exhaust gas flowing through the silencer body.

  Conventionally, a silencer body 1 having expansion chambers A and B formed therein from a shell 2 and a pair of end walls 3 and 4 closing both ends of the shell 2, and exhaust gas discharged from the engine is expanded into the expansion chamber A. , B, and an exhaust gas discharge pipe 20 for discharging the exhaust gas in the expansion chambers A, B to the outside of the silencer body 1. The exhaust gas introduction pipe 10 is provided in the pipe 10. An exhaust silencer is known in which the exhaust gas in the exhaust gas introduction pipe 10 is directly discharged to the outside without passing through the expansion chambers A and B when the on-off valve 12 provided in the valve is opened (patents described later). Reference 1).

JP 2008-45495 A

  However, what is disclosed in Patent Document 1 is that the exhaust gas introduction pipe 10 enters the silencer body 1 from one end wall 3, penetrates the silencer body 1 in the vertical direction, and the other end wall 4. Since the opening to the outside of the silencer main body 1 is opened, when the on-off valve 12 provided in the exhaust gas introduction pipe 10 is opened, the pipe length until the exhaust gas in the exhaust gas introduction pipe 10 reaches the opening is as follows. Not only does the exhaust gas flow resistance increase when exhaust gas is discharged directly from the opening without passing through the expansion chambers A and B, but the on-off valve 12 opens due to the increase in the flow resistance. When the valve is opened, the exhaust gas in the exhaust gas introduction pipe 10 easily flows into the expansion chambers A and B from the through-hole 11 on the upstream side of the on-off valve 12, and as a result, even if the on-off valve 12 is opened, the expansion chamber It is discharged directly from the opening without going through A and B When the amount of gas is reduced and the on-off valve 12 is opened, the flow resistance is reduced by directly discharging a large amount of exhaust gas from the opening without passing through the expansion chambers A and B, and the engine output thereby There was a problem that the improvement effect could not be sufficiently obtained.

  The present invention has been made in view of such a situation, and provides a novel exhaust silencer capable of reducing the flow resistance of exhaust gas flowing in the silencer body as much as possible to solve the above problem. For the purpose.

In order to achieve the above-mentioned object, the invention according to claim 1 includes a silencer body having a shell and a pair of end walls closing both ends of the shell, and having an expansion chamber inside, and exhaust discharged from the engine. In an exhaust silencer comprising: an exhaust gas introduction pipe that guides gas to an expansion chamber; and an exhaust gas discharge pipe that exhausts exhaust gas in the expansion chamber to the outside of the silencer body,
The exhaust gas introduction pipe passes through the shell between a pair of end walls and is connected to the silencer body, and passes through one branch pipe for introducing the exhaust gas into the expansion chamber and the silencer body. The downstream end is branched from one of the pair of end walls to the other branch pipe that opens to the outside of the silencer body,
The one branch pipe discharges exhaust gas in the pipe from the exhaust gas discharge pipe to the outside of the silencer body through the expansion chamber, and the other branch pipe has an exhaust gas passage in the pipe. An on-off valve that opens and closes is provided, and when the on-off valve is opened, exhaust gas is discharged from the other branch pipe to the outside of the silencer body.

  According to the first aspect of the present invention, the exhaust gas introduction pipe is connected to the silencer body through the shell between the pair of end walls, and the other branch of the exhaust gas introduction pipe provided with the on-off valve. Since the pipe opens to the outside of the silencer body from one end wall, the pipe length until the exhaust gas in the exhaust gas introduction pipe reaches the opening when the on-off valve is opened is shortened, and the flow resistance of the exhaust gas is reduced. In addition, by reducing the flow resistance to the opening when the on-off valve is opened, it is discharged directly from the opening without going through the expansion chamber when the on-off valve is opened. Since the amount of exhaust gas increases and the amount of exhaust gas flowing into the expansion chamber via one branch pipe that does not have an open / close valve decreases, the flow resistance increases due to exhaust gas being discharged through the expansion chamber. It can be greatly reduced. As a result, as a whole, the flow resistance of the exhaust gas flowing through the silencer body can be reduced as much as possible, thereby enhancing the output improvement effect of the engine.

Overall plan view of an exhaust system of a vehicle engine equipped with the exhaust 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 through 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 exhaust silencer 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 exhausts that exhaust the exhaust gases in the expansion chambers 20, 21, and 21 of the silencer main body 1 to the outside. 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. And expansion chambers 21 and 21 are formed between the inner separators 13 and 13 and the outer separators 14 and 14, and 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 second exhaust gas introduction pipes 2 </ b> R are provided on the shell 10, with the sound deadening chamber body 1 being biased closer to the left and right end walls 11 and 12 than the longitudinal center. Through-connection. 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 on-off valve V communicates with the downstream opening of the other branch pipe 4 whose inlet is connected to the opening 44 formed in the outer separator 14, and its outlet opens to the outside via the exhaust passage 33. Connected to the tail pipe 24. When the exhaust gas pressure in the first and second exhaust gas introduction pipes 2L and 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 valve is closed, the other branch pipe 4 and the outside are maintained in a disconnected state, and 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 The valve is opened against the elastic force of the spring 32, and the downstream 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) 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 exhausts that flow into the chamber 20 and then pass through the small holes 15 of the left and right inner separators 13 and 13 to be divided into the left and right expansion chambers 21 and 21, and the upstream sides thereof open into the expansion chambers 21 and 21. It is discharged to the outside through the 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 expansion in the expansion chambers 20, 21, and 21 and the silencing effect due to 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, but it can be applied to the exhaust system of engines for other purposes such as general purpose. It is.

1 ... silencer body 2L ... exhaust gas introduction pipe (first exhaust gas introduction pipe)
2R ... Exhaust gas introduction pipe (second exhaust gas introduction pipe)
3... One branch pipe 4... The other branch pipe 10... Shell 11... End wall (left end wall)
12 .... End wall (right end wall)
20 .... Expansion chamber 21 ... Expansion chamber E ... Engine V ... Open / close valve

Claims (1)

A silencer body (1) comprising a shell (10) and a pair of end walls (11, 12) closing both ends of the shell (10) and having expansion chambers (20, 21) inside;
Exhaust gas introduction pipes (2L, 2R) for guiding the exhaust gas discharged from the engine (E) to the expansion chambers (20, 21);
An exhaust gas exhaust pipe (5) for exhausting exhaust gas in the expansion chamber (20, 21) to the outside of the silencer body (1);
In the exhaust silencer equipped with
The exhaust gas introduction pipes (2L, 2R) pass through the shell (10) between the pair of end walls (11, 12) and are connected to the silencer body (1), and the expansion chambers (20, 21). ) Through one branch pipe (3) for introducing exhaust gas to the silencer body (1) and the downstream end from one of the pair of end walls (11, 12) to the outside of the silencer body (1) Branched to the other branch pipe (4) that opens to
The one branch pipe (3) allows the exhaust gas in the pipe (3) to pass through the expansion chamber (20, 21) from the exhaust gas discharge pipe (5) to the outside of the silencer body (1). Discharge,
The other branch pipe (4) is provided with an on-off valve (V) that opens and closes an exhaust gas passage in the pipe (4). When the on-off valve (V) is opened, the other branch pipe (4) The exhaust silencer is characterized by exhausting exhaust gas to the outside of the silencer body (1).

Images