JP4634813B2 - Engine exhaust system - Google Patents

Description

  The present invention relates to an exhaust system for an engine in which a silencer is mounted horizontally at the rear of a vehicle.

  Conventionally, a silencer is mounted horizontally at the rear of a vehicle in an exhaust system of an engine (see, for example, Patent Document 1). The silencer is generally formed in a substantially cylindrical shape, and is usually mounted on the rear portion of the vehicle in a so-called vertical state in which both ends are directed in the vehicle longitudinal direction and are elongated in the longitudinal direction, and is elastically supported on the vehicle body (for example, Patent Document 2). reference.). However, in recent years, there has been a problem of interior noise, and there has been a tendency for silencers to become larger due to the need for further reduction of exhaust noise. When such silencers become larger, interference with suspension cross members, etc. when installed vertically As a result, the space for mounting the silencer at the rear of the vehicle cannot be secured. For this reason, the silencer is placed horizontally, and the size is increased by extending it to the full extent in the vehicle width direction.

  However, if the silencer is mounted horizontally and thus becomes larger, the silencer becomes a heavy load, and the stress load on the exhaust pipe increases due to the heavy silencer that vibrates while connected to the exhaust pipe. To do.

  The engine is usually mounted at the front of the vehicle, and an exhaust pipe connected to the exhaust manifold of the engine extends to the rear of the vehicle and is connected to a silencer. A flexible joint and a flexible pipe are provided in the middle of the piping, and the exhaust pipe and the silencer are elastically supported, thereby reducing the vibration of the engine and transmission transmitted to the vehicle body, and the heat of the exhaust system. Expansion is absorbed. However, the conventional exhaust system does not take into consideration the problem of increasing the stress load on the exhaust pipe when the silencer is increased in size due to the horizontal mounting as described above, and the increase in the stress load can be suppressed. There wasn't.

  In the case where the silencer is vertically mounted, there is a conventional structure in which a flexible joint is disposed not only on the front connection portion close to the exhaust manifold but also on the rear connection portion close to the silencer (see Patent Document 2). In such a case, it is considered that the transmission of vibration between the silencer and the exhaust pipe is absorbed by the rear flexible joint. However, this is only for the case where the silencer is installed vertically, and when the size of the silencer that is difficult to install vertically is difficult, it is not assumed that the stress load of the exhaust pipe will increase due to the vibration of the heavy silencer. Absent.

  In addition, when a silencer is mounted horizontally at the rear of the vehicle, it is normal to connect the exhaust passage of the engine to the end plate on one end side, but if you expand it to the full width in the vehicle width direction to enlarge the silencer In addition, it is strict in terms of structure and space to route the exhaust passage and connect to the end plate so that it does not interfere with the suspension device etc. in the vicinity of the silencer, and in addition, it is conventional technology to arrange a flexible joint near the silencer. It was difficult.

JP 2002-70548 A JP 2000-64835 A

  As described above, when the silencer is mounted horizontally at the rear part of the vehicle to increase the size, the conventional technology has a problem that the stress load of the exhaust pipe increases due to the vibration of the silencer which is a heavy object, There is a problem that it is difficult in terms of structure and space to route the exhaust passage so as not to interfere with the suspension device and to dispose a flexible joint in the vicinity of the silencer so as to prevent an increase in stress load on the exhaust pipe.

  The present invention has been made in view of such a problem. The exhaust passage is reasonably arranged around the end plate on one end side of the silencer mounted horizontally at the rear of the vehicle so as not to interfere with the suspension device. The purpose is to reduce the stress load on the exhaust pipe due to vibration of the silencer by reasonably arranging a flexible joint between the silencer and the exhaust pipe in a narrow space.

According to the first aspect of the present invention, a substantially cylindrical silencer mounted on the rear part of the vehicle with both ends facing substantially in the vehicle width direction and long in the vehicle width direction is elastically supported on the vehicle body side, and one end of the silencer is An exhaust system for an engine comprising an engine exhaust passage mounted on a front part of a vehicle connected to a plate, wherein an exhaust introduction pipe is fixedly connected to an end plate on one end side of the silencer by being offset to the rear side of the vehicle body, and the exhaust introduction pipe And a rear exhaust pipe that forms an exhaust passage on the upstream side of the silencer are connected to each other in the vehicle width direction side of the end plate on one end side of the silencer via a flexible joint, and the silencer is connected to both ends of the silencer via elastic mounts at both ends. The front elastic mount and the rear elastic mount on the one end side are supported by the vehicle body. The rear exhaust pipe and the exhaust introduction pipe are inclined so that the rear is lowered in the vicinity of the connecting portion, and are arranged between the front elastic mount and the rear elastic mount on the one end side. and said that it has set.

  In this case, the exhaust passage is composed of a rear exhaust pipe and an exhaust introduction pipe at a portion close to the silencer, and is connected to the silencer at one end side end plate offset to the rear side of the vehicle body. The connecting portion moves to the rear side, so that the exhaust passage straddling the suspension device can be easily routed, and a space in which a flexible joint can be disposed on the side of the end plate in the vehicle width direction can be gained. Then, by connecting the introduction pipe and the rear exhaust pipe through a flexible joint arranged using the space, the vibration of the silencer is absorbed at a position close to the center of gravity of the elastically supported silencer, and then returned to the exhaust pipe. Transmission can be reduced.

  In this way, while exhaustively supporting the silencer elastically, the exhaust passage can be easily routed, and a flexible joint can be installed between the silencer and the exhaust pipe in a narrow space on the side of the end plate, and exhausted by the vibration of the silencer. The stress load on the tube can be reduced.

According to a second aspect of the present invention, in the engine exhaust system of the first aspect of the invention, the flexible joint is disposed between the front elastic mount and the rear elastic mount on one end side in a side view of the vehicle body. And

  With this configuration, the silencer can be firmly elastically supported, the exhaust passage can be easily routed and the flexible joint can be easily disposed, and the stress load on the exhaust pipe due to the vibration of the silencer can be effectively reduced.

  According to a third aspect of the present invention, in the engine exhaust system according to the first or second aspect, the rear exhaust pipe is disposed through a gap between the vehicle body floor above the suspension cross member extending in the vehicle width direction. And elastically supported on the vehicle body side.

  The transmission of silencer vibration to the rear exhaust pipe is reduced by the provision of a flexible joint to suppress the vibration of the rear exhaust pipe, and the rear exhaust pipe is elastically supported on the vehicle body side, so that even a curved rear exhaust pipe can be used. In this way, the suspension cross member can be disposed without interfering with the suspension cross member and the vehicle body floor through the narrow gap between the suspension cross member and the vehicle body floor.

According to a third aspect of the present invention, there is provided an exhaust system for an engine according to the present invention, wherein the front elastic mount and the rear elastic mount on the one end side are arranged such that the rear elastic mount is upward and the front elastic mount is downward as viewed from the side of the vehicle body. The rear exhaust pipe and the exhaust introduction pipe are disposed between the front elastic mount and the rear elastic mount so that the rear exhaust pipe and the exhaust introduction pipe are inclined in the vicinity of the connection portion.

  In this case, the rear exhaust pipe disposed through the gap between the suspension cross member and the vehicle body floor can be connected to the exhaust introduction pipe in an arrangement that does not interfere with the elastic mount without excessive bending in a narrow space.

According to a fourth aspect of the present invention, in the exhaust system for an engine according to the first, second, or third aspect of the invention, the exhaust lead-out pipe is connected to the one end side end plate that is the same as the side where the exhaust inlet pipe of the silencer is fixedly connected. A fixed connection is made at a position offset to the side.

  By concentrating the inlet (exhaust inlet pipe) and outlet (exhaust outlet pipe) on one end plate in this way, the pipe installation space for introducing and leading exhaust can be made compact, and the silencer can be enlarged accordingly. be able to.

According to a fifth aspect of the present invention, in the exhaust system for an engine according to the first, second, third, or fourth aspect of the present invention, support members that are suspended from elastic mounts are fixed around the both ends of the silencer, and the silencer is fixed to the support members. A plate member for restricting displacement in the vehicle width direction with respect to each of the elastic mounts is fixed.

  With this configuration, it is possible to restrict left and right (vehicle width direction) transition while allowing front and rear (vehicle longitudinal direction) and vertical movement of the silencer that can be absorbed by an elastic mount or flexible joint.

  As is clear from the above description, according to the invention of claim 1, the silencer is firmly elastically supported, the exhaust passage is easily routed, and the silencer and the exhaust pipe are arranged in a narrow space on the side of the end plate. A flexible joint can be easily installed between the two to reduce the stress load on the exhaust pipe due to the vibration of the silencer.

  According to the invention of claim 2 in particular, the silencer can be firmly elastically supported, the exhaust passage and the flexible joint can be easily arranged, and the stress load on the exhaust pipe due to the vibration of the silencer is effectively reduced. Can be reduced.

  In particular, according to the invention according to claim 3, the curved rear exhaust pipe is disposed without interfering with the suspension cross member or the vehicle body floor through the narrow gap between the vehicle body floor above the suspension cross member. it can.

  In particular, according to the invention of claim 4, the rear exhaust pipe disposed through the gap between the suspension cross member and the vehicle body floor is not bent excessively in a narrow space and does not interfere with the elastic mount in the exhaust introduction pipe. Can be connected.

  In particular, according to the fifth aspect of the invention, the space for installing the pipe for introducing and deriving exhaust gas can be made compact, and the silencer can be enlarged accordingly.

  In particular, according to the invention of claim 6, the left and right transitions can be restricted while allowing the silencer to move back and forth and up and down.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 4 show an example of an embodiment of the present invention. FIG. 1 is a view of a rear portion of a vehicle equipped with an exhaust device for an engine according to an example of an embodiment of the present invention as seen from below the floor, FIG. 2 is a plan view of the silencer, FIG. 3 is a rear view of the silencer, and FIG. It is a right view of a silencer.

In this embodiment, the present invention is applied to an exhaust system for an engine of a four-wheel drive vehicle. A rear exhaust pipe 1 that forms a rear exhaust passage of an engine (not shown) mounted on the front of the vehicle is shown in FIG. As shown in FIG. 1, the rear differential (rear differential) 2 is detoured to the right side (upper side in FIG. 1) as viewed from the front side of the vehicle ( left side in FIG. 1) at the rear of the vehicle body, and at a position near the side rail 3A on the right side. It stands up, straddles the cross member 4, the rear axle shaft 5 and the suspension cross (suspension cross member) 6 inside the side rail 3 </ b> A, and extends rearward through a gap between the vehicle body floor 7 and the suspension cross 6.

  At the rear of the vehicle, a large cylinder-shaped silencer 8 is disposed between the left and right side rails 3A and 3B in plan view behind the suspension cross 6 with the end plates 8a and 8b at both ends facing in the vehicle width direction. It is mounted in a horizontally long state in the vehicle width direction, and is elastically supported on the vehicle body side (side rails 3A, 3B) via mount rubbers (elastic mounts) 9A, 9B, 9C, 9D before and after both ends.

  The silencer 8 is provided with support rods (support members) 10A, 10B, 10C, and 10D that are suspended from mount rubbers 9A, 9B, 9C, and 9D at both ends. These support rods 10A, 10B, 10C, 10D are fixed to the end plates 8a, 8b at both ends of the silencer 8 by welding or the like as shown in FIGS. 2 to 4, and are viewed from the front side of the vehicle (left side in FIG. 1). The front mounting rubber 9B and the rear mounting rubber 9C on one end, which are on the right side (upper side in FIG. 1), are the rear mounting rubber 9C upward and the front mounting rubber 9B downward. Similarly, the front side mounting rubber 9A and the rear side mounting rubber 9D are arranged on the other side on the left side (lower side in FIG. 1). The arrangement is such that 9D is upward and the front mounting rubber 9A is downwardly offset. Further, the silencers of the mount rubbers 9A, 9B, 9C, and 9D are provided on the support rods 10A, 10B, 10C, and 10D so as to regulate the displacement of the silencer 8 with respect to the mount rubbers 9A, 9B, 9C, and 9D in the vehicle width direction. Plate members 11A, 11B, 11C, and 11D are fixedly provided on the 8 side, respectively.

  An exhaust introduction pipe 12 and an exhaust lead pipe 13 are fixedly connected to the silencer 8 on one end side end plate 8a that is on the right side (upper side in FIG. 1) when viewed from the front side of the vehicle (left side in FIG. 1). .

  The exhaust introduction pipe 12 is fixedly connected to a position offset from the center of gravity of the end plate 8a on the one end side toward the rear side of the vehicle body, and is bent between the front mounting rubber 9B and the rear mounting rubber 9C (front supporting bar). 10B and the rear support rod 10C) are configured to extend obliquely upward in the forward direction, and the connection flange 12a is disposed at a position that is offset obliquely upward from the center of gravity of the end plate 8a in the side view (see FIG. 4). I have.

  Then, the rear end portion of the rear exhaust pipe 1 extending rearward through a gap with the vehicle body floor 7 above the suspension cross 6 is bent rearward and obliquely downward, and the end plate 8a on the one end side of the silencer 8 is On the side in the vehicle width direction, it is connected to the exhaust introduction pipe 12 via a flexible joint 14 having a spherical sliding contact surface arranged between the front mounting rubber 9B and the rear mounting rubber 9C in a side view of the vehicle body. Yes. The rear exhaust pipe 1 and the exhaust introduction pipe 12 are connected with an inclination so that the rear part is lowered in the vicinity of the connection part, and the inclined part is located between the front mounting rubber 9B and the rear mounting rubber 9C. Yes. The rear exhaust pipe 1 is elastically supported on the vehicle body side (cross member 4) through a mount rubber (elastic mount) 9E at a position straddling the cross member 4.

  Further, the exhaust lead-out pipe 13 is fixedly connected at a position offset from the center of gravity of the end plate 8a to the lower front side of the vehicle body, is curved and extends rearward, and is connected to the tail pipe 15.

It is the figure which looked at the vehicle rear part of the motor vehicle provided with the exhaust apparatus of the engine which concerns on an example of embodiment of this invention from under the floor. It is a top view of the silencer in embodiment of FIG. It is a rear view of the same silencer. It is a right view of the same silencer.

Explanation of symbols

1 Rear exhaust pipe 6 Suspension cross (suspension cross member)
7 Body floor 8 Silencer 8a, 8b End plate 9A, 9B, 9C, 9D, 9E Mount rubber (elastic mount)
10A, 10B, 10C, 10D Support rod (support member)
11A, 11B, 11C, 11D Plate member 13 Exhaust outlet pipe 14 Flexible joint

Claims (5)

A substantially cylindrical silencer mounted on the rear of the vehicle with both ends facing in the vehicle width direction and long in the vehicle width direction is elastically supported on the vehicle body, and mounted on the end plate on the one end side of the silencer on the vehicle front In the exhaust system of the engine formed by connecting the exhaust passage of the engine,
An exhaust pipe is fixedly connected to the end plate on the one end side of the silencer by being offset to the rear side of the vehicle body, and the exhaust pipe and a rear exhaust pipe that forms an exhaust passage on the upstream side are connected to the end plate on the one end of the silencer. Connected to the side of the vehicle width direction through a flexible joint ,
The silencer is supported on the vehicle body through elastic mounts at both ends, and the front elastic mount and the rear elastic mount on the one end side are arranged such that the rear elastic mount is upward and the front elastic mount is downward in a side view of the vehicle body. The rear exhaust pipe and the exhaust introduction pipe are inclined between the front elastic mount on the one end side and the rear elastic mount so that the rear exhaust pipe and the exhaust introduction pipe are inclined in the vicinity of the connecting portion. An exhaust system for an engine. The exhaust apparatus according to claim 1, characterized in that disposed between the front resilient mounts and the rear resilient mounts at one end a pre-Symbol flexible joint in the side view of the vehicle body. The engine according to claim 1 or 2, wherein the rear exhaust pipe is disposed through a gap between the suspension cross member extending in the vehicle width direction and a vehicle body floor above the vehicle, and elastically supported on the vehicle body side. Exhaust system. 4. The engine according to claim 1 , wherein an exhaust lead-out pipe is fixedly connected to the end plate on the same end side as the side where the exhaust inlet pipe of the silencer is fixedly connected at a position offset to the front side of the vehicle body. Exhaust system. Claim 1 is fixed a supporting member for suspending the resilient mounts to the front and rear end of the silencer, characterized in that fixedly provided a plate member for restricting the displacement of the vehicle width direction with respect to the elastic mount of the silencer to their supporting members 2. The exhaust system for an engine according to 2, 3 or 4 .

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