JP4206323B2 - Support device for engine exhaust system in vehicle - Google Patents

Description

  The present invention relates to a support device for supporting an exhaust system of a vehicle engine on a vehicle body, and particularly in a vehicle in which a downstream portion of the exhaust system is elastically supported via an elastic body made of a rubber material or the like. The present invention relates to a support device for an engine exhaust system.

  An exhaust system including an exhaust pipe and a silencer is connected to an exhaust port of the vehicle engine. Since the exhaust system is usually long, the downstream portion is separately supported by the vehicle body at least at one location. In that case, the silencer provided in the downstream part of the exhaust system is relatively heavy, so that the exhaust system constitutes one vibration system, and when the vehicle body vibrates in the vertical direction, the exhaust system also moves vertically with respect to the vehicle body. Vibrate. Therefore, an elastic body made of a rubber material or the like is used for supporting the exhaust system.

As described above, when the exhaust system of the vehicle engine is elastically supported by the vehicle body via the elastic body, conventionally, vibration in the vertical direction between the vehicle body and the exhaust system is more effectively absorbed. Therefore, as the elastic body, one having a left-right symmetric shape having portions that are easily deformed in the vertical direction on both sides in the left-right direction of the vehicle body is used (for example, see Patent Document 1).
JP 2002-138826 A

  By the way, recent passenger cars are increasingly equipped with a flat ride. In the case of a vehicle with such a flat ride, even if the vehicle body vibrates in the vertical direction by passing through slight irregularities such as road joints while driving on a good road surface, the vibration is not Stops immediately with a damper. However, if the engine exhaust system is supported by the vehicle body via a conventional elastic body, the vertical vibration of the vehicle body is transmitted to the exhaust system as it is, so that the engine exhaust system vibrates in the vertical direction. Become. Moreover, the vibration does not stop immediately. If the exhaust system continues to vibrate in this way, the vibration is transmitted to the vehicle body in the opposite direction, and the vehicle body may be shaken in the vertical direction. In particular, when the exhaust system resonates in the vertical direction, the force that shakes the vehicle body in the vertical direction increases. For this reason, supporting the engine exhaust system on the vehicle body via the elastic body causes a decrease in riding comfort.

  As described above, in a conventional engine exhaust system support device in a vehicle, the influence on the riding comfort due to the vibration of the exhaust system cannot be ignored.

  The present invention has been made in view of such circumstances, and is an engine in a vehicle in which the exhaust system of the vehicle engine is supported via an elastic body and the ride comfort is less likely to be reduced by vibration of the exhaust system. An object of the present invention is to provide an exhaust system support device.

In order to achieve the above object, the invention of claim 1 is directed to an engine exhaust system support device for a vehicle in which an exhaust system of a vehicle engine is elastically supported on a vehicle body via an elastic body.
A support frame fixed to one of the vehicle body and the exhaust system, and a support member fixed to the other side,
The support frame includes an elastic body support frame portion formed in a pentagonal cylindrical shape surrounded by upper and lower walls, front and rear walls, and a slant wall that chamfers the corners of the front wall and the lower wall. The elastic body is provided in the elastic body support frame portion, and has a block portion having a support hole through which the support member is inserted and supported, and projects obliquely from the front surface of the block portion toward the front lower side. A front upper arm portion and a front lower arm portion, the block portion is located away from the elastic support frame portion, and the front ends of the front upper arm portion and the front lower arm portion are burned on the inner surface of the oblique wall. The elastic body is attached and converts the vibration in the vertical direction of the vehicle body into vibration including vibration components in the front-rear direction and transmits the vibration to the exhaust system .

  According to the first aspect of the invention, the elastic body converts the vertical vibration of the vehicle body into the vibration including the vibration component in the front-rear direction and is transmitted to the engine exhaust system. Therefore, the vertical vibration component of the exhaust system can be lowered accordingly. As a result, the vibration level transmitted from the exhaust system to the vehicle body via the elastic body is also reduced, so that the force for shaking the vehicle body in the vertical direction can be reduced. Therefore, it is possible to prevent a decrease in ride comfort.

First, a reference example of the present invention will be described based on the attached drawings.

1 to 5 show a support device for an engine exhaust system in a vehicle according to a reference example of the present invention , FIG. 1 is a perspective view showing the engine exhaust system support device, and FIG. 2 is an arrow 2 in FIG. 3 is a sectional view taken along line 3-3 in FIG. 2, FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG. 3, and FIG. 5 is an exploded perspective view of the supporting device. .

  As shown in FIG. 1, an engine exhaust system Ex for discharging exhaust gas discharged by the operation to the atmosphere is connected to an engine E of an automobile as a vehicle engine. The engine exhaust system Ex includes an exhaust pipe 1 that is connected to an exhaust port of the engine E via an exhaust manifold and extends rearward and a silencer M connected to a downstream portion of the exhaust pipe 1. The silencer M is supported by the lower part of the vehicle body B such that the longitudinal axis L-L is along the longitudinal direction of the vehicle body B, and thereby the downstream portion of the exhaust system Ex is supported by the vehicle body B. It has become.

  The silencer M has a sealed elliptic cylindrical shape, and the front end of the inlet pipe 2 extending forward from the front wall thereof is connected to the downstream end of the exhaust pipe 1 via the connection flange 3. Further, two tail pipes 4 and 4 protrude from the rear wall of the silencer M, and the rear ends of the tail pipes 4 and 4 are open to the atmosphere. The silencer M has a conventionally known silencer structure, and effectively absorbs exhaust noise generated from the exhaust gas flowing through the exhaust system Ex.

  As shown in FIGS. 1 to 5, the support device for the silencer M, which is a support device for the engine exhaust system Ex, includes a support frame 5 fixed to the lower part of the vehicle body B, and a support member 6 fixed to the silencer M. It has. The support frame 5 includes an elastic support frame portion 7 in the form of a short rectangular tube whose upper and lower front and rear surfaces are closed by upper and lower walls 7a and 7b and front and rear walls 7c and 7d, and left and right side surfaces are opened. The upper mounting part 8 extends upward from the rear wall 7d and the lower mounting part 9 extends rearward from the lower wall 7b. The upper and lower mounting portions 8 and 9 are fixed to the front and lower surfaces of the cross member Bc that extends in the vehicle width direction and supports the floor panel Bf by bolts and nuts 10 and 11, respectively. It has become. By fixing the support frame 5 in such a manner, the elastic body support frame portion 7 of the support frame 5 becomes parallel to the front-rear direction of the vehicle body B.

  As is clear from FIGS. 2 and 4, an elastic body 12 made of a rubber material is provided in the elastic body support frame portion 7. The elastic body 12 has a left-right width that is the same as or slightly wider than the left-right width of the elastic body support frame portion 7, and faces the front and lower sides of the central block portion 12a and the front surface of the block portion 12a. A forearm portion 12b projecting diagonally and a rear arm portion 12c projecting rearward and upward from the rear surface of the block portion 12a. Then, the front end of the forearm portion 12 b is baked on the inner surface of the corner between the front wall 7 c and the lower wall 7 b of the elastic body support frame portion 7, and the rear end of the rear arm portion 12 c is the elastic body support frame portion 7. It is baked on the inner surface of the corner between the upper wall 7a and the rear wall 7d. In this way, the elastic body 12 is fixed to the elastic body support frame portion 7 such that the central block portion 12a is located away from the elastic body support frame portion 7 and is movable up and down. Further, the central block portion 12a of the elastic body 12 is provided on the inner surface of the corner portion between the upper wall 7a and the front wall 7c of the elastic body support frame portion 7 and the inner surface of the corner portion between the lower wall 7b and the rear wall 7d. Stopper rubbers 13 and 14 that are in contact with each other when they move up and down and forward and backward are respectively baked.

  Further, a support hole 15 penetrating in the left-right direction of the vehicle body is formed at the center of the central block portion 12a of the elastic body 12. The support member 6 is inserted into and supported by the support hole 15. As is apparent from FIG. 5, the support member 6 is formed of a bent bar-like stay, and the base end portion of the support member 6 is an intermediate portion of the front-rear mounting member 16 attached to the upper portion of the silencer M. It is fixed through. Further, the distal end portion of the support member 6, that is, the free end portion extends in the left-right direction of the vehicle body, and a poppet-shaped escape prevention portion 6 a is integrally formed at the distal end.

  In order to fix the mounting member 16, front and rear brackets 17 and 18 are fixed to the upper edges of the front and rear portions of the silencer M slightly offset from the longitudinal axis LL. These brackets 17 and 18 are provided with bolt holes 17a and 18a, respectively. On the other hand, mounting bolts 19 and 19 are fixed to the front and rear ends of the mounting member 16, respectively. Thus, the mounting bolts 19 and 19 are inserted into the bolt holes 17a and 18a of the front and rear brackets 17 and 18, and the nuts 20 and 20 are tightened, whereby the mounting member 16 is fixed to the upper portion of the silencer M. ing.

  As described above, the silencer M constituting a part of the engine exhaust system Ex fixes the support member 6 fixed to the mounting member 16 fixed to the silencer M to the support frame 5 fixed to the vehicle body B. The elastic body 12 is elastically supported by the vehicle body B through the elastic body 12 by being inserted into and supported by the support hole 15 of the elastic body 12. The elastic body 12 extends obliquely upward from the front side to the rear side of the vehicle body B, and has arm portions 12 b and 12 c that connect the support frame 5 and the support member 6.

Next, the operation of this reference example will be described.

  When the vehicle body B vibrates in the vertical direction while the vehicle is traveling, the vibration is transmitted to the engine exhaust system Ex via the elastic body 12. In that case, the engine exhaust system Ex constitutes a vibration system different from the vehicle body B, so that the exhaust system Ex vibrates relative to the vehicle body B.

  For example, suppose that the vehicle now rides on a small protrusion on the road surface and the vehicle body B moves upward. At that time, since the exhaust system Ex tries to maintain its position by inertial force, the support member 6 fixed to the silencer M of the exhaust system Ex is relative to the support frame 5 fixed to the vehicle body B. Try to move downward. That is, a downward force is applied to the support member 6. The force is F in FIG. If there is no elastic body 12, the support member 6 moves downward by the input F.

  However, the elastic body 12 has the property of being deformed in the shearing direction without being deformed as much as possible in the compression direction. Further, the support member 6 supported by the elastic body 12 has a property of applying a force in a direction in which the front and rear arm portions 12b and 12c are deformed substantially uniformly. As a result, the support member 6 is displaced in the direction P by the illustrated force P. The force P has substantially the same magnitude as the input F from the vehicle body B, and is in a direction substantially orthogonal to the front and rear arm portions 12b, 12c of the elastic body 12. That is, the direction includes the longitudinal component of the vehicle body. Therefore, the vertical component Pv of the force P is smaller than the input F from the vehicle body B.

  In this way, the vertical vibration of the vehicle body B is converted by the elastic body 12 into vibration including a vibration component in the vehicle longitudinal direction, and transmitted to the engine exhaust system Ex. Therefore, even when the vibration of the vehicle body B is stopped by the suspension damper and only the vibration of the exhaust system Ex is continued, the vertical vibration transmitted from the exhaust system Ex to the vehicle body B on the contrary is initially transmitted from the vehicle body B to the engine. It becomes smaller than the vibration transmitted to the exhaust system Ex. In general, the floor panel Bf of the vehicle body B of the vehicle has low rigidity in the vertical direction, and when vibrations in the vertical direction are input, the vibrations are easily felt in the passenger compartment, which greatly affects riding comfort. According to the elastic body 12 of this reference example, as described above, the vibration component in the vertical direction transmitted from the engine exhaust system Ex to the vehicle body B is reduced, so that a reduction in riding comfort is prevented.

It will now be described real施例of the present invention with reference to FIG.

Figure 6 is an enlarged side view of a main part showing the actual施例engine exhaust system of the support device according to the present invention.

Note that in the actual施例, the portion different from the reference example is the shape of the supporting frame and the elastic body, the description for corresponding parts as in Reference Example by the same reference numerals, without redundant description.

As shown in FIG. 6, in the case of the embodiment of the present invention, the elastic body support frame portion 27 of the support frame 5 includes upper and lower walls 27a and 27b, front and rear walls 27c and 27d, and its front wall 27c and lower wall 27b. It is made into the short pentagonal cylinder shape enclosed by the slant wall 27e which chamfers the corner | angular part between these, and the both right and left side surfaces were open | released. The elastic body 32 includes a block portion 32a having a support hole 15 penetrating in the vehicle width direction, a front upper arm portion 32b projecting obliquely from the lower front portion of the block portion 32a toward the front lower side, and a block portion 32a. A front lower arm portion 32c is also provided which projects from the lower surface front portion toward the front lower side. The front ends of the front upper arm portion 32 b and the front lower arm portion 32 c are baked on the inner surface of the inclined wall 27 e of the elastic body support frame portion 27. In this way, the elastic body 32 is fixed to the elastic body support frame 27 so that the block portion 32a is located away from the elastic body support frame 27 and is movable up and down.

Since other configurations are the same as those of the reference example , detailed description thereof is omitted.

In the engine exhaust system support device having such a configuration, when vertical vibration is input from the vehicle body B, the vibration is caused by the elastic body 32 as diagonal vibration including a vibration component in the front-rear direction. It is transmitted to the support member 6 that supports the exhaust system Ex. Therefore, the engine exhaust system Ex vibrates in an oblique direction, and the vertical vibration component transmitted from the exhaust system Ex to the vehicle body B is reduced, so that the ride comfort of the vehicle is prevented from being lowered.

Having described the actual施例of the present invention, the present invention is not limited to these examples, and various embodiments within the scope of the present invention.

For example, the supporting lifting frame 5 is fixed to the vehicle body B side, the support member 6 instead of fixed to the engine exhaust system Ex, the supporting frame 5 to the engine exhaust system Ex side, the supporting member 6 on the vehicle body B side, the fixed You may make it do.

The perspective view which shows the support apparatus of the engine exhaust system in the vehicle of a reference example Side view seen from the direction of arrow 2 in FIG. Sectional view along line 3-3 in FIG. Enlarged cross-sectional view along line 4-4 in FIG. An exploded perspective view of a support device for the engine exhaust system Cross-sectional view similar to FIG. 4 showing the actual施例of the present invention

Explanation of symbols

5 ... Support frame 6 ... Support member 15 ... Support hole
27 ... Elastic body support frame
27a ... Upper wall
27b ... Lower wall
27c ... Front wall
27d · · · rear wall
27e..Slanted wall 32. Elastic body
32a block part
32b .. Forearm
32c ··· Lower arm B ··· Body E · · · Engine Ex · · · Engine exhaust system · · · Muffler

Claims (1)

In an engine exhaust system support device for a vehicle, the exhaust system (Ex) of the vehicle engine (E) is elastically supported by the vehicle body (B) via the elastic body (32) .
A support frame (5) fixed to one of the vehicle body (B) and the exhaust system (Ex), and a support member (6) fixed to the other side (Ex),
The support frame (5) is surrounded by upper and lower walls (27a, 27b), front and rear walls (27c, 27d), and an inclined wall (27e) chamfering the corners of the front wall (27c) and the lower wall (27b). And an elastic body support frame portion (27) formed in a pentagonal cylindrical shape with both left and right side surfaces open, and the elastic body (32) is provided in the elastic body support frame portion (27). Then, a block part (32a) having a support hole (15) through which the support member (6) is inserted and supported, and a front upper arm part (32b) projecting obliquely from the front surface of the block part (32a) toward the front lower side And the front lower arm portion (32c), the block portion (32a) is located away from the elastic support frame portion (27), and the front upper arm portion (32b) and the front lower arm portion (32c). ) Are baked on the inner surface of the inclined wall (27e), and the elastic body 32), the vertical vibration of the vehicle body (B), characterized in that it transmitted to the exhaust system (Ex) by converting the vibration including the vibration components of the front-rear direction, the engine exhaust system of the support device in a vehicle .

Images