JPH0426298Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the structure of a subframe body mount for a vehicle having a subframe type suspension support mechanism.

[Conventional technology]

BACKGROUND ART Conventionally, a subframe that supports a differential of an automobile supports a body through body mounts provided at the front and rear parts of the subframe, respectively. FIG. 4 is a cross-sectional view showing an example of the structure of a conventional body mount, in which a body side mount mounting seat 2 with a nut 23 welded and fixed to the body 21 is shown.
2 is provided. On the other hand, body mount 31
has an inner cylinder 28, an outer cylinder 29, and a vibration isolating rubber 30 fixed between the inner cylinder 28 and the outer cylinder 29, and the outer cylinder 29 is fixed to the subframe 27. Moreover, the inner cylinder 28 of the body mount 31 is
It is tightened to the body side mount mounting seat 22 by a bolt 24 and a nut 25 via a stopper 26.

[Problem that the invention attempts to solve]

However, in the conventional body mount structure described above, various vibrations of the subframe transmitted to the body depend on the hardness of the vibration isolating rubber. In other words, lowering the rubber hardness increases the level of wind-up vibration of the subframe due to the reaction force of torque from the differential supported by the subframe, resulting in body vibration during acceleration, low-speed muffled noise, and sudden deceleration. The drawback was that the unpleasant noise and vibrations, such as the sound of impact, were increased.

On the other hand, if the hardness of the rubber was increased in order to eliminate the above-mentioned drawbacks, the vibrations of the sub-frame due to unevenness of the road surface would be directly transmitted to the body, resulting in poor riding comfort.

An object of the present invention is to suppress vibrations of the subframe due to torque reaction force from a differential supported by the subframe, and to absorb vibrations of the subframe due to unevenness of the road surface.
The purpose is to provide a subframe body mount structure.

[Means to solve the problem]

In order to achieve the above object, the present invention consists of a front mount and a rear mount each having an inner cylinder and an outer cylinder, and a vibration isolating rubber is installed between the inner cylinder and the outer cylinder. In the structure of the subframe body mount, in which the body is supported by the subframe by fixing the outer cylinder to a subframe that supports a differential, The rubber consists of two vibration-proof rubber rings attached to the upper and lower parts of the inner cylinder and the outer cylinder, respectively, so as to form a liquid chamber in the space between the inner cylinder and the outer cylinder, Each liquid chamber of the mount is divided into an upper liquid chamber and a lower liquid chamber by a partition plate with an orifice function protruding from the inner wall of the outer cylinder, and the upper liquid chamber of one mount is separated from the liquid chamber of the other mount. It is characterized in that it is communicated with the lower liquid chamber through a connecting pipe.

[Effect]

In the present invention configured as described above, the upper liquid chamber of one mount and the lower liquid chamber of the other mount are communicated with each other through a connecting pipe, so that the torque reaction force of the differential is applied to the subframe. When the subframe makes a pitching motion, the pressure fluctuations in the fluid chambers that communicate with each other become the same, so the apparent spring constant of each mount increases, suppressing pitching vibration of the subframe. On the other hand, when the subframe bounces due to unevenness in the road surface, liquid flows from the fluid chamber where the pressure increases to the fluid chamber where the pressure decreases among the fluid chambers that communicate with each other.
The apparent spring constant of each mount is reduced, and the vibrations of the subframe are absorbed by the mount.

〔Example〕

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

FIG. 1 is a perspective view of the overall structure of one embodiment of the subframe body mount structure of the present invention, and FIGS. 2a and 2b are sectional views of the front mount and rear mount of FIG. 1, respectively.

The front mount 10 has a liquid chamber surrounded by an inner cylinder 8, an outer cylinder 9, an upper vibration-proof rubber ring 3, and a lower vibration-proof rubber ring 4. This liquid chamber is formed by a partition plate 5 having an orifice 6 protruding from the inner wall of the outer cylinder 9.
The liquid chamber 7 is divided into an upper liquid chamber 7 and a lower liquid chamber 13, and each liquid chamber 7, 13 is filled with liquid. Further, one end of a metal pipe 12 serving as a connecting pipe is attached to the upper liquid chamber 7.

The rear mount 11 has the same structure as the front mount 10, but has an upper liquid chamber 14 and a lower liquid chamber 15.
The other end of the pipe 12 is connected to the lower liquid chamber 15, and the upper liquid chamber 7 of the front mount 10 and the lower liquid chamber 15 of the rear mount 11 communicate with each other via the pipe 12.

On the other hand, the subframe 17 that supports the differential 18 has a subframe-side front mount mounting seat 2a and a subframe-side rear mount mounting seat 2b at its front and rear parts, respectively, and the outer cylinder 9 of the front mount 10 is fixed to the front mount mounting seat 2a on the subframe side, and the outer cylinder of the rear mount 11 is fixed to the rear mount mounting seat 2b on the subframe side. Further, the inner cylinder 8 of the front mount 10 and the inner cylinder of the rear mount 11 are each fixed to a body side mount mounting seat of the body 1 with bolts and nuts. Due to this, the body 1 is attached to the subframe 17,
It is elastically supported by a front mount 10 and a rear mount 11.

Next, the operation of this embodiment will be explained.

First, the operation when the subframe 17 performs a bouncing motion will be described. The bouncing motion is a motion in which both the front and rear sides of the subframe 17 move toward or away from the body 1, and is caused by unevenness of the road surface or the like.

If the subframe 17 moves closer to the body 1, the partition plate 5 will also move closer to the body 1 as the subframe 17 moves, so the pressure in the upper liquid chambers 7 and 14 of each mount 10 and 11 will increase. The pressure in the lower liquid chambers 13 and 15 decreases. Here, since the upper liquid chamber 7 of the front mount 10 and the lower liquid chamber 15 of the rear mount 11 are communicated with each other through the pipe 12, the liquid in the upper liquid chamber 7 of the front mount 10 is transferred to the lower liquid chamber 15 of the rear mount 11. Flows into chamber 15.

For the same reason, when the subframe 17 moves away from the body 1, the liquid in the lower liquid chamber 15 of the rear mount 11 flows into the front mount 1.
0 to the upper liquid chamber 7.

This reduces the load applied to the subframe 17 during movement of the subframe 17,
Since the apparent spring constant of each mount 10, 11 is reduced, the subframe 17
The bouncing motion is absorbed by each mount 10, 11, improving riding comfort.

Next, the operation when the subframe 17 performs pitching motion will be explained. Pitching motion means that when the front side of subframe 17 approaches body 1, the rear side of subframe 17 moves away from body 1, and conversely, when the front side of subframe 17 moves away from body 1, the rear side of subframe 17 moves toward body 1. This movement is caused by the torque reaction force of the differential 18, etc.

Now, when the front side of the subframe 17 moves closer to the body 1, the pressure in the upper liquid chamber 7 of the front mount 10 increases for the reason described above. At this time, since the rear side of the subframe 17 moves away from the body 1, the pressure in the lower liquid chamber 15 of the rear mount 11 also increases. In this way, pipe 1
2, the pressure fluctuations in the upper liquid chamber 7 of the front mount 10 and the pressure fluctuations in the lower liquid chamber 15 of the rear mount 11 are the same, so that the liquid between the front mount 10 and the rear mount 11 is There is no movement. Further, even if the front and rear parts of the subframe 17 move in opposite directions, the liquid does not move for the same reason. As a result, the load applied to the subframe 17 increases when the subframe 17 moves, and the apparent spring constant of the front mount 10 and rear mount 11 increases, so that the differential 18
The wind-up vibration level due to the torque reaction force from is suppressed.

FIG. 3 is a graph in which the relationship between vehicle speed and vibration according to the conventional mount structure shown in FIG. 4 is represented by a broken line, and the relationship between vehicle speed and vibration according to the embodiment of the present invention is represented by a solid line. It turns out that it has a considerable effect.

[Effect of idea]

As explained above, the present invention attaches anti-vibration rubber rings to the upper and lower parts between the inner and outer cylinders of both the front mount and rear mount of the vehicle subframe to form liquid chambers, and these liquid chambers function as orifices. The subframe is divided into two chambers, upper and lower, by a partition plate with a When pitching motion occurs due to torque reaction force, etc., the apparent spring constant of both mounts increases and suppresses the movement of the subframe.On the other hand, when the subframe makes a bouncing motion due to unevenness of the road surface, etc. The apparent spring constant of the mount is reduced, absorbing vibrations from the subframe, and has the effect of improving the ride comfort of the vehicle.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the overall structure of one embodiment of the structure of the subframe body mount of the present invention, Fig. 2 a and b are sectional views of the front mount and rear mount of Fig. 1, and Fig. 3 is the subframe body mount of the present invention. FIG. 4 is a graph comparing the relationship between vehicle speed and vibration between the body mount structure of 2008 and the conventional body mount structure, and FIG. 4 is a cross-sectional view of the conventional body mount structure. 1...Body, 2a...Front mount mounting seat on the subframe side, 2b...Rear mount mounting seat on the subframe side, 3...Upper anti-vibration rubber ring, 4...
Lower anti-vibration rubber ring, 5... Partition plate, 6... Orifice, 7, 14... Upper liquid chamber, 8... Inner cylinder, 9...
Outer cylinder, 10...Front mount, 11...Rear mount, 12...Pipe, 13, 15...Lower liquid chamber, 17...Subframe, 18...Differential.

Claims (1)

[Claims for Utility Model Registration] Consisting of a front mount and a rear mount, each having an inner cylinder and an outer cylinder, and with anti-vibration rubber installed between the inner cylinder and the outer cylinder, the inner cylinder is attached to the body. and a structure of a subframe body mount in which the body is supported by the subframe by fixing the outer cylinder to a subframe that supports a differential, wherein for both the mounts, the vibration isolating rubber is , consisting of two vibration-proof rubber rings attached to the upper and lower parts of the inner cylinder and the outer cylinder, respectively, so as to form a liquid chamber in the space between the inner cylinder and the outer cylinder, and of both the mounts. Each liquid chamber is divided into an upper liquid chamber and a lower liquid chamber by a partition plate having an orifice function, which is protruded from the inner wall of the outer cylinder, and the upper liquid chamber of one mount and the lower side of the other mount. A subframe body mount structure that is characterized by communicating with the liquid chamber through a connecting pipe.