JP3256288B2 - Exhaust pipe support device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe support device, and more particularly to an exhaust pipe support device mounted on a vehicle such as an automobile.

[0002]

2. Description of the Related Art A conventional exhaust pipe supporting apparatus is disclosed, for example, in Japanese Utility Model Laid-Open No. 57-46020. In this exhaust pipe support device, as shown in FIG. 5, a U-shaped bracket 31 fixed to a vehicle body is filled with a support rubber 32, and the support rubber 32 is formed with an insertion hole 33 through which a rod for exhaust pipe support is inserted. Have been. Insert hole 3
A hole 34 for absorbing vibration in the vertical direction of the exhaust pipe is formed in a lower center portion of 3, and a hole 35 for absorbing vibration in the horizontal direction of the exhaust pipe is formed on the left and right of the hole 34. The exhaust pipe moves up and down, left and right, and back and forth due to engine vibration or vehicle body vibration from the road surface. However, since the support rubber 32 itself is a viscoelastic body, even if the vibration is applied, the internal friction of the rubber causes It has the advantage of damping quickly.

[0003]

However, since the spring constant of rubber greatly changes due to heat, the damping characteristics at high temperatures deteriorate, and the rubber constant is also affected by the spring constant. Furthermore, since the dynamic magnification (dynamic spring constant / static spring constant) is high, there is a problem that vibration attenuation in a high frequency range is not good.

On the other hand, there has been proposed an exhaust pipe support device in which a metal spring is disposed in a support bracket and the rod for elastically supporting the exhaust pipe is elastically supported by the metal spring.
However, since the metal coil spring is a rigid body, it cannot be expected that vibration is attenuated due to internal friction, and there is a problem of surging that vibration is not immediately attenuated when vibration is applied.

It is an object of the present invention to obtain stable vibration damping which is not affected by temperature, frequency and deterioration which are characteristics of a metal spring, while surging which is a disadvantage of a metal spring is caused by vibration damping which is arranged in contact with the metal spring. An object of the present invention is to provide an exhaust pipe supporting device that can be suppressed by the body.

[0006]

According to a first aspect of the present invention, there is provided a support frame mounted on a vehicle body, and a pair of support frames fixed at positions separated from each other in the support frame. a vibration damping body, each thereof to the pair of vibration attenuator
The ends are fitted with two or more turns in contact with each other, and
When provided so as to slide relative to each vibration damper
In addition , a gist of the present invention includes a pair of coil springs having a vibration damping characteristic smaller than that of the vibration damper, and a support member elastically supported between the coil springs and supporting an exhaust pipe .

[0007]

According to the present invention constructed as described above, the coil spring is elastically deformed by the vibration of the exhaust pipe in the up, down, left, right, front and rear directions, but a part of the coil spring comes into contact with the vibration damper having a large internal friction damping. The vibration energy of the coil spring is absorbed by the vibration damper. Therefore, the vibration transmitted from the exhaust pipe support device to the vehicle body can be reduced, and the vibration noise can be greatly improved. In addition, this greatly improves the damping characteristic, which has been a disadvantage of the conventional metal coil spring, and reduces vibration noise due to the low dynamic magnification (dynamic spring constant / static spring constant) which is an advantage of the coil spring. Can be used to the maximum.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an exhaust pipe supporting device for a vehicle will be described below with reference to FIGS.

As shown in FIG. 2, a support bracket 1 serving as an exhaust pipe support device is fixed to a vehicle body 2. The exhaust pipe 3 is supported by the support bracket 1 via a support rod 4 fixed to the exhaust pipe 3. That is, the support rod 4 has the top portion in the axial direction of the exhaust pipe 3 (Y1-Y2
A rod portion 5 extending in the direction (direction) is provided, and the exhaust pipe 3 is elastically supported between the rod portion 5 and the support bracket 1 as described later.

As shown in FIG. 1, a housing 6 as a support frame comprises a U-shaped main body housing 7 and an upper housing 8 connected and fixed between upper side walls of the main body housing 7 to constitute an exterior of the support bracket 1. are doing. Bolt tightening holes 9 and 10 are provided at both ends of the housings 7 and 8, and the housing 6 is fastened and fixed to a floor or a cross member on the vehicle body 2 side by inserting bolts (not shown). A space S is provided between the upper housing 8 and the main body housing 7. A frusto-conical stopper rubber 11 as a vibration damping body and a columnar stopper rubber 12 are fixed to the central portions of the upper housing 8 and the main body housing 7 which face each other so as to face each other. Both stopper rubbers 11 and 12 are heat-resistant E
It is formed from PDM. Also, the stopper rubber 1
Reference numerals 1 and 12 restrict excessive movement of the attachment body 16 in the vertical direction (Z1-Z2 direction).

A frustoconical coil spring 13 is fitted on the stopper rubber 11 with a part thereof in contact therewith. A cylindrical coil spring 14 is fitted on the stopper rubber 12 with a part thereof in contact therewith. At least two portions of the coil springs 13 and 14 that come into contact with the outer periphery of the stopper rubbers 11 and 12 are provided.
It is more than a volume . It should be noted that the coil spring 1 in Volume 1
3,14 is the case of contact with the stopper rubbers 11 and 12, since the vibration damping characteristics of the object can not be obtained, it is necessary on Volume 2 than <br/> is. And the coil spring 13,
The vibration damping characteristics of 14 are smaller than the vibration damping characteristics of the stopper rubbers 11 and 12. This contact is preferably a line contact. The reason is that if the contact surface pressure is too high, the spring constants of the coil springs 13 and 14 increase,
Ru Der because rather there is an adverse effect on the vibration noise. In line contact
Also the coil springs 13 and 14 and the stopper rubbers 11 and 1
2, a sufficient frictional resistance acts to attenuate the vibration energy transmitted from the exhaust pipe. Double coil spring 1
An annular bracket 15 is welded and fixed to a base end of each of the upper and lower housings 3 and 14 at a plurality of locations.
Therefore, the coil springs 13, 14 are positioned so as not to move even when a load in the lateral direction is applied.

The rod mounting body 16 as a supporting member is composed of a rubber body 17 made of heat-resistant EPDM and a metal frame 18 provided so as to cover the outer periphery thereof. A cylindrical projection 1 is provided on both upper and lower portions of the rod mounting body 16.
9, 20 are formed. The two coil springs 13, 14 are provided on both projections 19, 20 of the rod mounting body 16.
The free end is fitted in, their respective free ends the rod mounting member 1
6 are respectively engaged with the upper and lower surfaces 16a, 16b at the center. The coil springs 13, 14
1 is longer than the vertical length shown in FIG. 1 in a free state, and is attached by compressing the free ends of the coil springs 13 and 14 and fitting them to the projections 19 and 20 of the rod mounting body 16. You.

At the center of the rod mounting member 16, both side portions in the left-right direction (X1-X2 direction) are stopper portions 21, 22.
The main body housing 7 when vibrating in the left-right direction.
Of the rod mounting body 16 in the left-right direction (X
Excessive movement in the (1-X2 direction) is restricted. The rod mounting hole 2 is provided in the frame 18 and the rubber body 17 of the rod mounting body 16.
3 is provided in the Y1-Y2 direction.

The rod portion 5 of the support rod 4 is loosely inserted into the rod mounting hole 23 as shown in FIG. Then, in this assembled state, that is, in the state where the exhaust pipe 3 is supported, the support bracket 1 configured as described above, as shown in FIG.
Appropriate gaps are formed between the stopper rubber 9 and the stopper rubber 11, and between the protrusion 20 of the rod mounting body 16 and the stopper rubber 12, respectively. That is, the coil springs 13 and 1
4 is selected to have a spring constant such that an appropriate gap is formed between the upper and lower protrusions 19 and 20 of the rod mounting body 16 in the state where the exhaust pipe 3 is supported. Therefore, the rod mounting body 16 is elastically movable in the vertical direction between the stopper rubbers 11 and 12 together with the rod portion 5 of the support rod 4.

When the exhaust pipe 3 is supported, the rod mount 16 is located at the center between the inner surfaces of the main body housing 7 in the left-right direction (X1-X2 direction). A large space is formed between both inner surfaces of the housing 7. Therefore, the rod mounting body 16 is elastically supported by the coil springs 13 and 14 and can move in the left-right direction until the stopper portions 21 and 22 come into contact with the inner surface of the main body housing 7.

Next, the operation of the support bracket 1 configured as described above will be described with reference to FIG. FIG. 2 shows a state where the rod portion 5 of the support rod 4 is assembled to the rod mounting body 16 and the engine is stopped.
The rod mount 16 is stationary at the intermediate position shown in FIG.

During the operation of the engine or the running of the vehicle, the exhaust pipe 3 has a vibration action in all directions due to the vibration of the engine body or the vibration received by the vehicle body 2 from the road surface. The vibration acting force acting on the exhaust pipe 3 directly becomes the vibration acting force of the rod mounting body 16 via the support rod 4.

For example, of the vibration acting force, the vertical direction (Z1
−Z2 direction) component, the rod mounting body 1
6 vibrates up and down. In the process of moving the rod mounting body 16 upward due to this vibration, the coil spring 13 is compressed and deformed, and the coil spring 14 is expanded and deformed. During the downward movement, the coil spring 13 is expanded and deformed, and the coil spring 14 is compressed and deformed. For this reason, while the rod attachment body 16, that is, the exhaust pipe 3 is supported by the vehicle body 2 by the coil springs 13 and 14, the vibration of the exhaust pipe 3 in the vertical direction (Z 1 -Z 2 direction) is reduced by the elasticity of the two coil springs 13 and 14. Absorbed by deformation. The fixed ends of the coil springs 13 and 14 are in contact with the stopper rubbers 11 and 12 having a larger vibration damping characteristic than the coil springs 13 and 14, that is, the internal friction damping is large.
The vibration energy of 14 is absorbed by the stopper rubbers 11 and 12 .

For this reason, a damping effect equivalent to that of a conventional exhaust pipe supporting device that uses only a rubber-based support can be obtained.
For example, FIG. 3A shows the damping characteristic of the exhaust pipe supporting device using only the rubber support used in the conventional exhaust pipe supporting device and the damping characteristic of the support bracket 1 according to the embodiment of the present invention. It is a vibration damping curve figure which shows that it was the same. FIG. 3B is a vibration damping curve of a conventional exhaust pipe supporting device using only a metal coil spring.

Therefore, the vibration is prevented from being transmitted to the housing 6, that is, the vehicle body 2 . In response to a large vertical vibration of the exhaust pipe 3, the rod mounting body 16 is restricted in the vertical direction by the stopper rubbers 11 and 12, so that the coil springs 13 and 14 may be deformed beyond the elastic limit. Is prevented. Since the stopper rubbers 11 and 12 are made of rubber, even if the rod mounting body 16 and the stopper rubbers 11 and 12 collide, no noise is generated at the time of collision.

Further, the rod mounting body 16 vibrates in the left-right direction due to the vibration acting force of the left-right direction (X1-X2 direction) component. Due to this vibration, the rod mounting body 16 is moved in the left-right direction, so that the moving directions of the coil springs 13 and 14 are compressed, and the non-moving directions are elongated. For this reason, the rod attachment body 16, that is, the exhaust pipe 3 is supported by the vehicle body 2 by the coil springs 13 and 14,
The vibration of the exhaust pipe 3 in the left-right direction (X1-X2 direction) is absorbed by the elastic deformation of the coil springs 13 and 14. Since the fixed ends of the coil springs 13 and 14 are in contact with the stopper rubbers 11 and 12 having a larger vibration damping characteristic than the coil springs 13 and 14, that is, the internal friction damping is large, the vibration energy of the coil springs 13 and 14 is increased. Is absorbed by the stopper rubbers 11 and 12. For this reason, the same damping effect as that of the exhaust pipe supporting device performed only with the conventional rubber-based support can be obtained as in the case of the vertical vibration. Therefore, the left and right vibrations are
That is, transmission to the vehicle body 2 is prevented.

In response to a large vibration in the left-right direction of the exhaust pipe 3, the movement of the rod mounting body 16 in the left-right direction is restricted by the stoppers 21, 22, so that the coil springs 13, 14 are deformed beyond the elastic limit. Is prevented. Since the insides of the stopper portions 21 and 22 are formed integrally with the rubber body 17, the rod mounting body 16 is formed.
Even if the main body housing 7 and the main body 7 collide with each other, no noise is generated at the time of collision.

Also, the axial direction of the exhaust pipe 3 (Y1-Y2 direction)
The support rod 4 vibrates in the axial direction due to the vibration acting force of the component. However, since the rod portion 5 of the support rod 4 is loosely inserted into the rod mounting body 16 along the axial direction, the rod portion 5 The shaft 6 slides in the axial direction with respect to the rod mounting body 16, and the vibration of the axial component of the exhaust pipe 3
That is, transmission to the vehicle body 2 is prevented.

FIG. 4 shows the engine speed (rpm) on the abscissa and the sound pressure level in the vehicle on the ordinate, and the dotted line shows the exhaust pipe support using only a conventional rubber support to support the exhaust pipe. The inside sound of the device is shown, and the solid line shows the inside sound in this embodiment. From this graph, it can be seen that especially when the rotational speed is 3900 to 5000 rpm, the in-vehicle sound is more effective than the conventional one.

As described above, in the support bracket 1 of the present embodiment, the exhaust pipe 3 is securely supported by the vehicle body 2 and
Vibrations and noises of the exhaust pipe 3 in all directions are absorbed by the coil springs 13 and 14 and the stopper rubbers 11 and 12, and are prevented from being transmitted to the vehicle body 2 .

The present invention is not limited to the above embodiment, but can be realized as follows. (1) In the above embodiment, the stopper rubbers 11 and 12 are made of heat-resistant EPDM. However, the stopper rubbers may be made of wire mesh, that is, knitted fine wires in a knit shape and compression molded.

Since the wire mesh vibration damper has a larger damping characteristic than the coil springs 13 and 14,
The same effects as in the above embodiment can be obtained, and it is particularly suitable when the use environment is severe at a very high temperature or the like.

[0028]

As described above in detail, according to the present invention, the coil spring is elastically deformed by the vibration of the exhaust pipe.
Since a part of the coil spring is in contact with the vibration damper having a large internal friction damping, the vibration energy of the coil spring is absorbed by the vibration damper. Therefore, the vibration transmitted from the exhaust pipe support device to the vehicle body can be reduced, and the vibration noise can be greatly improved. In addition, this greatly improves the damping characteristic, which has been a drawback of the conventional metal coil spring, so that the reduction of vibration noise due to the low dynamic magnification, which is an advantage of the coil spring, can be maximized. In addition, since the vibration noise can be reduced by the low dynamic magnification of the coil spring, the vibration attenuation particularly in a high frequency range can be improved.

In addition, there is an excellent effect that surging of the coil spring can be suppressed despite the use of the coil spring.

[Brief description of the drawings]

FIG. 1 is a perspective view of an exhaust pipe supporting apparatus according to an embodiment of the present invention;
It is an I line sectional view.

FIG. 2 is a view showing a support structure of an exhaust pipe used in the exhaust pipe support device shown in FIG.

FIG. 3A is a vibration damping curve diagram showing a vibration damping characteristic of a conventional rubber support and a support bracket according to an embodiment of the present invention, and FIG. 3B is a vibration damping curve showing a vibration damping characteristic of a conventional coil spring. It is a curve figure.

FIG. 4 is a graph showing the effect of reducing noise in a vehicle between a conventional rubber support and an embodiment of the present invention.

FIG. 5 is a front sectional view showing a conventional exhaust pipe support device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Support bracket (exhaust pipe support apparatus), 2 ... Body, 3 ... Exhaust pipe, 4 ... Support rod, 5 ... Rod part,
6 ... housing (support frame), 7 ... body housing, 8 ...
Upper housing, 11: stopper rubber (vibration damping body),
12: stopper rubber (vibration damping body), 13: coil spring, 14: coil spring, 16: rod mounting body (supporting member), 17: rubber body, 18: frame, 19: projection, 20: projection, 21 ... stopper part, 22 ... stopper part, 23 ... rod mounting hole, S ... space part.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mitsunori Ota 23 Ridge Denjiyama 404 No. 23, Denjiyama 1, Narumi-cho, Midori-ku, Nagoya-shi

Claims (1)

(57) [Claims] And 1. A support frame is attached to the vehicle body, said pair of vibration damping member that is fixed at a position spaced from one another in the support frame, the pair of vibration attenuator in each end thereof, Volume 2 or more Contact with
And fitted relative to each of the vibration dampers.
A pair of coil springs, which are provided so as to slide in and have a smaller vibration damping characteristic than the vibration damper, and a support member elastically supported between the two coil springs and supporting an exhaust pipe. Exhaust pipe support device .