JPH05106432A - Exhaust device for vehicle - Google Patents

Abstract

(57) [Summary] [Purpose] To ensure smooth opening and closing of the exhaust control valve regardless of the vibration of the exhaust pipe. [Structure] A valve unit 7 is disposed in a portion where the two exhaust front pipes 5 and 6 communicate with each other.
An exhaust control valve 17 that reduces exhaust noise by opening and closing is provided in the internal communication passage 16. The exhaust control valve 17 is provided adjacent to the universal joint 8. As a result, even if the vehicle and the exhaust front pipes 5 and 6 are subjected to vibration during traveling, the universal joint 8 is relatively easy to bend among the exhaust pipes. Become one.
Therefore, the vibration of the valve unit 7 near the universal joint 8 is relatively small, and the opening / closing of the exhaust control valve 17 is less likely to be affected by the vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle exhaust system, and more particularly to an exhaust system provided with an exhaust control valve in an exhaust pipe of an internal combustion engine mounted on a vehicle.

[0002]

2. Description of the Related Art Conventionally, a "vehicle exhaust system" disclosed in, for example, Japanese Utility Model Publication No. 1-83123 is known as this type of technology. In this technique, an opening / closing valve is provided in a communication passage that connects two exhaust pipes connected to an exhaust manifold of an engine. The sound pressure level of the exhaust noise is reduced by controlling the open / close valve according to the change in the engine speed.

[0003]

However, in the above-mentioned prior art, since the exhaust pipe vibrates as the vehicle travels, the on-off valve is located in a portion where the exhaust pipe vibrates violently, that is, in the antinode portion of the vibration. When it is located, the vibration may make it difficult to operate the on-off valve smoothly.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an exhaust system for a vehicle capable of ensuring smooth opening and closing of an exhaust control valve regardless of vibration of an exhaust pipe. Especially.

[0005]

In order to achieve the above object, in the first invention, an exhaust pipe constituting an exhaust system of an internal combustion engine mounted on a vehicle, and an exhaust pipe provided in the middle of the exhaust pipe are provided. In an exhaust system of a vehicle equipped with an exhaust control valve that is opened and closed to control the flow of the exhaust gas, a universal joint that allows refraction of the exhaust pipe is provided in the middle of the exhaust pipe, and the exhaust control valve is provided near the universal joint. I am trying to provide it.

According to the second aspect of the invention, an exhaust pipe constituting an exhaust system of an internal combustion engine mounted on a vehicle, and an exhaust control which is provided in the middle of the exhaust pipe and is opened / closed to control the flow of exhaust gas. In a vehicle exhaust system including a valve, the vicinity of the exhaust control valve is supported by an exhaust pipe support member.

[0007]

According to the first aspect of the present invention, when the exhaust pipe vibrates as the vehicle travels, the universal joint serves as a node portion with relatively little vibration. Since the exhaust control valve is provided in the vicinity of this universal joint, vibration of the exhaust control valve can be relatively small. Therefore, opening / closing of the exhaust control valve is less likely to be affected by vibration.

Further, according to the second aspect of the invention, when the exhaust pipe vibrates as the vehicle travels, the support member becomes a node portion with relatively little vibration. Since the exhaust control valve is provided in the vicinity of this support member, vibration of the exhaust control valve can be relatively small. Therefore, opening / closing of the exhaust control valve is less likely to be affected by vibration.

[0009]

【Example】

(First Embodiment) A first embodiment of the first invention will now be described in detail with reference to FIGS.

FIG. 2 is a schematic plan view for explaining an exhaust system for a vehicle in this embodiment. In the figure, an exhaust system of a four-cylinder engine 1 as an internal combustion engine mounted on the front part of a vehicle includes four exhaust ports 2A, 2 for each cylinder.
A pair of exhaust manifolds 3 communicating with B, 2C and 2D
4 are provided. One exhaust manifold 3 is connected to the front and rear two exhaust ports 2A and 2D, and the other exhaust manifold 4 is connected to the central two exhaust ports 2B and 2C. One ends of exhaust front pipes 5 and 6 forming an exhaust pipe are connected and fixed to the pair of exhaust manifolds 3 and 4, respectively. The other ends of the exhaust front pipes 5 and 6 are connected to the catalytic converters 9 and 10 via the valve unit 7 and the universal joint 8. Further, the downstream side of the catalytic converters 9 and 10 is the collecting pipe 1
1. The branch pipe 13 is connected via the sub muffler 12, and the end of the branch pipe 13 has main mufflers 14 and 15
Is linked to.

Each exhaust port 2A of the engine 1-
The exhaust gas discharged from 2D is exhausted from each exhaust manifold 3,
4, the exhaust front pipes 5, 6, the valve unit 7, and the universal joint 8 to flow into the catalytic converters 9, 10. Then, the exhaust gas is purified by a metal catalyst or the like in the catalytic converters 9 and 10, and then the collecting pipe 11 and
Sub muffler 12, branch pipe 13 and main muffler 1
It is designed to be released to the outside through 4, 15.

Inside the valve unit 7 provided in the middle of each exhaust front pipe 5, 6, both pipes 5,
A communication passage 16 that communicates between 6 is provided. Also,
An exhaust control valve 17 for opening and closing is provided in the communication passage 16. By opening / closing the exhaust control valve 17, the communication passage 16 is opened / closed, and as a result, exhaust noise is reduced.

A universal joint 8 is provided adjacent to the valve unit 7. Next, the valve unit 7
The universal joint 8 will be described in detail. In FIG. 2, the valve unit 7 is a unit body 1 made of stainless steel.
8, the flange 18a is connected and fixed to the flange 19 of the exhaust front pipes 5 and 6 by a bolt via a gasket (not shown). This unit body 1
In order to reduce the weight, No. 8 is thin-walled by vacuum casting.

FIG. 1 is a sectional view showing the valve unit 7 and the universal joint 8, and FIG. 3 is a partial sectional view taken along the line AA in FIG. As is clear from these figures, the communication passage 16 in the unit main body 18 has a rectangular cross section, and the exhaust control valve 17 is arranged therein. The exhaust control valve 17 has a valve body 20 having a thick central portion and a rectangular shape corresponding to the cross section of the communication passage 16, and a disc portion 21 integrally formed at the base end of the valve body 20. Is equipped with. A shaft 22 is formed so as to project downward from the center of the disc portion 21, and a shaft 23 is similarly formed so as to project upward from the center of the valve body 20. Further, a bearing recess 24 corresponding to the shaft 22 and a recess 25 corresponding to the disc portion 21 are formed in the bottom wall of the communication passage 16. The shaft 22 is fitted in the bearing recess 24 via a bush 26 and is rotatably supported. Further, the disc portion 21 is fitted in the recess 25 so as to be flush with the bottom wall of the communication passage 16.

On the other hand, as shown in FIG. 3, an opening 27 that opens upward is formed in the communication passage 16 at a position corresponding to the exhaust control valve 17. The shaft 23 is arranged so as to project upward from the opening 27. A bush 28 is arranged around the shaft 23 so as to close the opening 27,
The shaft 23 is rotatably supported. Also, bush 28
Above the shaft 23, a retainer 29 is fitted around the shaft 23, and between the retainer 29 and the bush 28, a ring seal 30,
31 is interposed. Further, as shown in FIGS. 3 and 4, a substantially diamond-shaped plate 32 is fastened and fixed by bolts 33 to the upper surface of the unit body 18 so as to cover the retainer 29 and the upper surface of the bush 28. Has been done. In this way, the exhaust control valve 17 has the shaft 22,
It is rotatably supported about 23.

A lever 34 is attached to the tip of the shaft 23 projecting upward from the plate 32 so as to rotate integrally with the shaft 23. A pin 35 protruding upward is provided at one end of the lever 34. A spring plate 36 is interposed between the lever 34 and the plate 32 so as to cover a part of the plate 32. The spring plate 36 is formed with an arcuate projection 36a centering on the shaft 23, and the projection 36a is in contact with the lower surface of the lever 34. As a result, the lever 34
Is biased upward to prevent its rattling.

As shown in FIGS. 5 and 6, the unit main body 18
An actuator 37 for rotating the lever 34 is attached and fixed to a side portion of the with a bolt 39 via a bracket 38. A pair of holding members 40 and 41 are provided inside the actuator 37.
A diaphragm 42 is sandwiched between 0 and 41. The peripheral edge of the diaphragm 42 is attached to a flange 43 protruding to the outer circumference of the actuator 37, and the inside of the actuator 37 is partitioned by the diaphragm 42 into a negative pressure chamber 37a and an atmospheric pressure chamber 37b. A base end of an operating rod 44 that extends outward from the atmospheric pressure chamber 37b is connected to central portions of the sandwiching members 40 and 41. The tip of the operating rod 44 is rotatably connected to the pin 35. Further, in the negative pressure chamber 37a, a compression spring 45 is interposed between the holding member 41 and the bottom wall of the actuator 37. The compression spring 45 urges both the clamping members 40, 41 and the diaphragm 42, so that the operating rod 44 is urged in the outward extending direction as shown by the solid line in FIG. In this state, the lever 34 is arranged at the position indicated by the solid line in FIG. 5, and is arranged at the valve opening position where the exhaust control valve 17 is opened.

Further, the negative pressure chamber 37a is provided with a pressure port 46 extending outward. When the negative pressure is introduced into the negative pressure chamber 37a through the pressure port 46, the holding members 40, 41 and the diaphragm 42 are pulled against the urging force of the compression spring 45, and the operating rod 4
4 is pulled in the direction of contracting inside the actuator 37 as shown by the chain double-dashed line in FIG. In this state, the lever 34
Is arranged at the position indicated by a chain double-dashed line in FIG. 5, and the exhaust control valve 17 is arranged at a closed position where the communication passage 16 is closed.

Further, in this embodiment, a stopper for restricting the position of the lever 34 is provided. That is, as shown in FIG. 5, a bracket 47 protruding upward is provided on the upper surface of the unit main body 18 near the lever 34. On the bracket 47, a pair of bolts 48 and 49 that form a stopper are provided.
Mounted in parallel by 53. One bolt 4
8 is arranged so as to be able to contact one end of the lever 34 near the pin 35. Further, the other bolt 49 is arranged so as to be able to contact the other end of the lever 34.

Therefore, the rotation range of the lever 34 is regulated by adjusting the nuts 50 to 53 and adjusting the abutting positions of the bolts 48 and 49 with respect to the lever 34, so that the opening position of the exhaust control valve 17, The valve closing position is determined.

In this embodiment, the actuator 37
The introduction of negative pressure and atmospheric pressure into the negative pressure chamber 37a is switched by a vacuum switching valve (VSV) not shown. Therefore, when a negative pressure is introduced into the negative pressure chamber 37a by the control of the VSV in the state shown by the solid line in FIG. 5, that is, in the state where the exhaust control valve 17 is in the open position, the operating rod 44 moves in the direction of contracting Then, the lever 34 is rotated to the position indicated by the chain double-dashed line in FIG. 5, and the exhaust control valve 17 is switched to the closed position. Further, the introduction into the negative pressure chamber 37a is switched from the negative pressure to the atmospheric pressure by controlling the VSV. As a result, the operating rod 44 moves in the extending direction, the lever 34 is pivotally returned to the position indicated by the solid line in FIG. 5, and the exhaust control valve 17 is returned to the valve opening position.

In this way, the exhaust control valve 17 is appropriately opened / closed according to the engine speed and the like,
The exhaust noise of the engine 1 is reduced. Next, the structure of the universal joint 8 will be described.

As shown in FIG. 1, the universal joint 8 includes a pair of flexible relay pipes 54, whose central portion has a slightly reduced diameter.
55, and one ends of these relay pipes 54, 55 are fitted into the two openings 18b, 18c on the downstream side of the unit main body 18. These relay pipes 54, 55
Bellows tubes 57 and 58 having a bellows-shaped flexible portion 56 in the central portion are externally fitted to the outside. Also, the bellows tube 5
A pair of support covers 5 so as to cover the outer periphery of 7,58
9, 60 are arranged so as to partially overlap each other. As shown in FIGS. 1 and 7, the one support cover 59 includes a fixed portion 59a, an enlarged diameter portion 59b, and a cover portion 5.
It is composed of 9c. The fixed portion 59a is a portion fitted to the outer peripheral surface of one end of the bellows tubes 57, 58, and the expanded diameter portion 59b is continuous with the fixed portion 59a and has a tapered shape in which the diameter increases as it goes to the flexible portion 56. ing. The cover portion 59c is formed so as to cover the outer periphery of the flexible portion 56, and two protrusions 59d are formed on both sides of the cover portion 59c so as to project. The base end of the one support cover 59 is joined to both openings 18b, 18c of the unit body 18 by full-circumferential welding W1.

The other support cover 60 is also composed of a fixed portion 60a, an expanded diameter portion 60b and a cover portion 60c. The cover portion 60c is located inside the cover portion 59c of the one support cover 59, and pin holes 60d are formed at positions corresponding to the protrusions 59d on both sides.

Both of these support covers 59, 60 have a connecting pin 6 provided on the projection 59d and the pin hole 60d.
1 are interconnected via a wire mesh 62. The wire mesh 62 is obtained by weaving a thin wire and compressing it into a predetermined shape, and has elasticity. In addition, the connecting pin 61 includes a cylindrical portion 61a and a flange portion 61 that radially protrudes from a base end portion of the cylindrical portion 61a.
and b. The flange portion 61b of the connecting pin 61 is fixed to the inner surface of the inner support cover 60 by spot welding W2. The cylindrical portion 61 a of the connecting pin 61 penetrates the pin hole 60 d of the support cover 60 and extends into the protrusion 59 d of the one support cover 59.

As described above, the universal joint 8 in this embodiment has a pin joint type joint structure, and the both support covers 59, 60 are rotatable relative to each other about the connecting pin 61 in the vertical direction to some extent. Is becoming Also,
When both support covers 59 and 60 are rotated,
The bellows pipes 57, 58 and the relay pipes 54, 55 are allowed to bend to some extent.

Therefore, when vibration is applied while the vehicle is running, the flexible portions 56 of the bellows tubes 57 and 58 and the wire mesh 62 of the connecting pin 61 are elastically deformed. Further, since the two connecting pins 61 connecting the support covers 59 and 60 rotate about the pin 61 in the vertical direction to some extent, the vibrations of the exhaust front pipes 5 and 6 are absorbed and reduced.

Next, the operation of the vehicle exhaust system configured as described above will be described. While the vehicle is running, the vehicle undergoes some vibrations due to road surface irregularities and the like. With this,
The exhaust front pipes 5 and 6 forming the exhaust pipe are also subject to vibration. At this time, since the universal joint 8 is relatively easy to bend among the exhaust front pipes 5 and 6,
This universal joint 8 becomes one of vibration nodes. In this embodiment, since the exhaust control valve 17 is provided in the vicinity of the universal joint 8, that is, the joint, vibration in the vicinity of the exhaust control valve 17 can be relatively small. Therefore, the exhaust control valve 17 and the unit main body 18 do not interfere with each other due to the vibration, and the smooth opening and closing of the exhaust control valve 17 can be ensured.

Further, as described above, the clearance between the exhaust control valve 17 and the unit body 18 can be made smaller because the exhaust control valve 17 can be opened and closed smoothly. As a result, leakage of exhaust gas when the exhaust control valve 17 is fully closed can be reduced, and the effect of reducing exhaust noise can be made more effective.

Further, in this embodiment, the bellows tube 5 is used.
Most of 7,58 are covered with support covers 59,60. Therefore, bellows tubes 57, 58
Can be reliably protected from stepping stones and road surface interference.

In addition, these support covers 59, 60
This reduces the amount of snow-melting salt that adheres to the bellows pipes 57 and 58 for preventing road surface freezing. Therefore, the progress of high temperature salt damage corrosion of the bellows tubes 57, 58 can be suppressed.

Further, since the wire mesh 62 having elasticity is interposed in the connecting pin 61 portion, contact between the support covers 59 and 60 and direct contact between the connecting pin 61 and the support covers 59 and 60 are prevented. In addition, it is possible to prevent the tapping sound from being generated due to vibration.

(Second Embodiment) Next, a second embodiment of the second invention will be described in detail with reference to FIGS.

FIG. 8 is a schematic view for explaining the exhaust system for a vehicle in this embodiment. In the figure, an exhaust system of a four-cylinder engine 71 as an internal combustion engine mounted on the front part of a vehicle includes four exhaust ports 72A, 72B for each cylinder.
An exhaust manifold 73 that communicates with 72C and 72D is provided. One end of an exhaust front pipe 74 is connected and fixed to the exhaust manifold 73. Further, the other end of the exhaust front pipe 74 is connected to the catalytic converter 75.
Is linked to. Further, the downstream side of the catalytic converter 75 is connected to an exhaust rear pipe 76 that constitutes an exhaust pipe,
The end of the exhaust rear pipe 76 is connected to the muffler 77.

Each exhaust port 72 of the engine 71
The exhaust gas discharged from A to 72D flows into the catalytic converter 75 through each exhaust manifold 73 and the exhaust front pipe 74. Then, the exhaust gas is purified by a metal catalyst or the like in the catalytic converter 75, and then released to the outside through the exhaust rear pipe 76 and the muffler 77.

A valve unit 78 is arranged in the middle of the exhaust rear pipe 76. An exhaust control valve 79 for an exhaust brake is provided in the main body of the valve unit 78. The exhaust control valve 79 is opened and closed by a vacuum cylinder (not shown),
By closing the exhaust control valve 79 while the vehicle is traveling,
The flow of exhaust gas in the exhaust control valve 79 is blocked, the internal resistance of the engine 71 is increased, the engine brake is applied, and the vehicle is decelerated.

On the downstream side of the valve unit 78 and the muffler 77, tube side brackets 80 and 81 projecting upward are provided. Further, in the vehicle body 82, vehicle body side brackets 83 and 84 that hang downward are provided at positions corresponding to the pipe side brackets 80 and 81, respectively. The pipe side brackets 80, 81 and the vehicle body side brackets 83, 84 are connected via the support member 85, whereby the exhaust rear pipe 76 and the muffler 7 are connected.
7 is supported by the vehicle body 82.

As shown in FIG. 9, the support member 85 is formed of a rubber elastic body in a substantially rectangular ring shape, and mounting holes 86 and 87 are formed at the upper and lower portions thereof, respectively, which face each other. The vehicle body side bracket 8 is provided in the upper mounting hole 86.
3, 84, the pipe side bracket 8 in the upper mounting hole 87
0 and 81 are inserted respectively. Further, the left and right portions of the support member 85 facing each other are elastic arm portions 88 and 89 capable of expanding and contracting. Vibration is absorbed by the elastic arm portions 88 and 89.

Next, the operation and effect of the vehicle exhaust system configured as described above will be described. When the exhaust rear pipe 76 and the muffler 77 are vibrated while the vehicle is traveling, the exhaust rear pipe 76 and the muffler 77 are absorbed by the support member 85. Therefore, the support member 85 is included in the exhaust rear pipe 76 and the muffler 77.
The vicinity of is the node with the least vibration. Further, in this embodiment, since the exhaust control valve 79 for the exhaust brake is provided near the support member 85, vibration near the exhaust control valve 79 is relatively small.

As a result, the exhaust control valve 79 is caused by the vibration.
And the valve unit 78 will not interfere with each other,
It is possible to ensure smooth opening and closing of the exhaust control valve 79.
The present invention is not limited to the above-described embodiments, and a part of the configuration can be appropriately modified without departing from the spirit of the invention and can be carried out as follows.

(1) In the first embodiment, the so-called pin joint type joint structure in which the support covers 59, 60 of the universal joint 8 are connected by the connecting pin 61 is used, but in addition to that, for example, a hinge type joint or a spherical joint. It may be configured to be connected by.

(2) In the first embodiment, an exhaust control valve 17 for reducing exhaust noise is provided near the universal joint 8, and in the second embodiment, the exhaust control valve 7 for exhaust brake.
Although the vicinity of 9 is supported by the support member 85, on the contrary, the vicinity of the exhaust control valve 17 of the first embodiment is supported by the support member, and the exhaust control valve 79 of the second embodiment is universal joint. It may be configured to be provided in the vicinity of.

(3) In the first embodiment, the exhaust control valve 17 for reducing the exhaust noise is provided, and in the second embodiment, the exhaust control valve 79 for the exhaust brake is provided. The exhaust control valve may be provided for any purpose.

(4) In the first embodiment, the support cover 60 and the connecting pin 61 are formed as separate members, but the supporting cover 60 may be formed by pressing to form a pin conforming to the connecting pin 61. Good.

[0045]

As described in detail above, according to the first invention, the exhaust control valve is provided in the vicinity of the universal joint portion of the exhaust pipe, so that the exhaust control can be performed despite the vibration of the exhaust pipe. It has an excellent effect that the valve can be opened and closed smoothly.

Further, according to the second invention, since the vicinity of the exhaust control valve is supported by the exhaust pipe support,
This has an excellent effect that the exhaust control valve can be smoothly opened and closed despite the vibration of the exhaust pipe.

[Brief description of drawings]

FIG. 1 is a plan sectional view showing a valve unit and a universal joint as main parts in a first embodiment embodying the first invention.

FIG. 2 is a plan view showing an exhaust system of a vehicle in the first embodiment.

FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1 showing an exhaust control valve mounting structure in the first embodiment.

FIG. 4 is a partial plan view showing the movement of the lever of the valve unit in the first embodiment.

FIG. 5 is a plan view showing the outer appearance of the valve unit in the first embodiment.

FIG. 6 is an end view showing the outer appearance of the valve unit in the first embodiment.

FIG. 7 is a side view showing the universal joint in the first embodiment.

FIG. 8 is a schematic side view showing an exhaust system for a vehicle in a second embodiment embodying the second invention.

FIG. 9 is a diagram showing a support member and the like in a second embodiment.

[Explanation of symbols]

1, 71 ... Engine as internal combustion engine, 5, 6 ... Exhaust front pipe constituting exhaust pipe, 8 ... Universal joint, 17,
79 ... Exhaust control valve, 76 ... Exhaust rear pipe constituting exhaust pipe, 85 ... Support member.

Claims (2)

[Claims] 1. A vehicle equipped with an exhaust pipe that constitutes an exhaust system of an internal combustion engine mounted on a vehicle, and an exhaust control valve that is provided in the middle of the exhaust pipe and that is opened and closed to control the flow of exhaust gas. The exhaust system of a vehicle according to claim 1, wherein a universal joint that allows refraction of the exhaust pipe is provided in the middle of the exhaust pipe, and the exhaust control valve is provided in the vicinity of the universal joint. 2. A vehicle equipped with an exhaust pipe that constitutes an exhaust system of an internal combustion engine mounted on a vehicle, and an exhaust control valve that is provided in the middle of the exhaust pipe and is opened and closed to control the flow of exhaust gas. 2. The exhaust system for a vehicle according to claim 1, wherein the vicinity of the exhaust control valve is supported by a support member of the exhaust pipe.