JPS6354568B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a vibration-proof mounting device for a vehicle such as an automobile.

[Conventional technology and its problems]

Generally, a vibrating body such as an engine, transmission, or body mount of an automobile generates vibrations as the automobile travels, and as a result, muffled noise or the like may be generated. Therefore, in order to prevent such vibrations, vibration isolation mechanisms for supporting the above-mentioned vibrating bodies and damping and absorbing the vibrations of the vibrating bodies have been proposed.

For example, to prevent muffled noise, it is common practice to reduce the dynamic spring constant, but this also reduces the static spring constant, which increases the amount of movement of the engine, transmission, etc. This results in other problems such as a decrease in the durability of the vibration mechanism itself. On the other hand, for continuous and fine vibrations called swaying vibrations, it is necessary to increase the damping coefficient, but this also increases the spring constant, making the muffled sound even worse. It is occurring.

The present invention has been made in order to solve the problems of the prior art described above, and it supports a vibrating body so as to attenuate and absorb the vibrations of the vibrating body, and also prevents the support member itself from causing a resonance phenomenon. It is an object of the present invention to provide a vibration-isolating mount device for a vehicle that can obtain a vibration-isolating effect.

[Means for solving problems]

In order to achieve the above object, the present invention provides a vibration isolating mount device for supporting a vibrating body such as a vehicle engine or transmission. a vibration support member in the form of an inverted gutter with an open bottom that integrally includes members in the longitudinal direction; and an elastic member that is accommodated in an open groove of the support member and connects the side member and the attachment member to the body frame; A tuning mass element is fixed along the longitudinal direction of the side member in the support member to prevent resonance between the frequency of the vibrating body and the natural frequency of the support member. .

[Effect]

In such a configuration, the vibration support member that receives vibration from the vibrating body is formed in the shape of an inverted gutter with an open bottom that integrally extends in the longitudinal direction with a pair of side members that hang down from both sides of the mounting portion of the vibrating body, and the side members A tuning mass element is fixed along its longitudinal direction.

Therefore, it is possible to suppress an increase in the weight of the support member and easily shift the resonance point of the vibration frequency of the vibrating body and the natural frequency of the support member in the normal use range without reducing the durability and reliability. (The natural frequency refers to the unique frequency of vibration of an object when the object vibrates without being subjected to external force.) The above structure of the present invention and the salience of its operation will be more clearly understood from the following explanation. I can do it.

FIG. 4 schematically shows the state of the vibration support member and the tuning mass element fixed thereto. Note that the vibration support member corresponds to the upper metal fitting 3 in the embodiment described later.

As shown in the figure, the support member 3 includes a pair of side members 3 hanging from both sides of a back surface 3a attached to the vibrating body.
It has b. A tuning mass element 10 is fixed to the side member 3b along its longitudinal direction.
The back surface 3a portion has a substantially flat plate shape and relatively low rigidity. l is the distance from the back surface of the support member to the mass attachment center, and the moment l x mass acts as the tuning mass. On the other hand, among the input vibrations, the problematic resonance vibration is in the horizontal direction (or left and right direction) of the hanging part.
The resonance point of the vibration can be shifted by fixing the tuning mass element at a distance l from the support member.

Here, simply reducing the thickness of the supporting member uniformly and lowering its rigidity will lower the natural frequency of the supporting member, but there is an upper limit to the durability and reliability of lowering the rigidity.
A resonance point occurs in the normal use range. On the other hand, simply increasing the plate thickness uniformly and increasing the rigidity will increase the natural frequency of the supporting member, but since the weight will increase, the amount of increase in the natural frequency will be small. This will add a lot of weight. There are also cases where it is impossible to install.

In the present invention, as shown in the drawings, the support member 3 has a side member 3b that hangs down, and the tuning mass element 1
0 is fixed along the longitudinal direction of the side member 3b. Therefore, it is possible to lower the resonance point by making the rigidity of the parts involved in the natural frequency relatively low and by increasing the mass of the side members.

Furthermore, as described above, by fixing the tuning mass element 10 to the side member 3b along its longitudinal direction, the side member 3b has both rigidity against torsion in the longitudinal direction (rigidity in the direction indicated by the arrow in the figure) and strength. is improved.

Therefore, it is possible to suppress an increase in the weight of the support member and easily shift the resonance point between the frequency of the vibrating body in the horizontal direction (or left and right direction) and the natural frequency of the support member in the normal use range without reducing the durability and reliability. becomes possible. In addition, by replacing the tuning mass element, it can be easily adapted to engines with different specifications.

〔Example〕

The present invention will be further described below with reference to embodiments shown in the drawings.

Fig. 1 is a side view of the anti-vibration mount device according to the present invention installed as a rear mount insulator at the rear of the vehicle, as seen from the left side of the vehicle;
The figure is a partially sectional view taken along the - line in FIG. 1, as seen from the rear side of the vehicle.

As is clear from FIG. 1, a rear mount insulator 1 constituting a vibration isolation mechanism is attached to the lower side of a transmission extension housing 2 (vibrating body) of a vehicle. That is,
An upper metal fitting 3 (vibration support member) of the rear mount insulator 1 is fixed to the lower surface of the transmission extension housing 2 by an upper mounting bolt 4 for the rear mount insulator. As is clear from the figure, this upper metal fitting 3 has a downwardly opened inverted gutter-like groove shape integrally having a pair of side members 3b hanging down from both sides of the mounting portion 3a secured to the mounting bolt 4 in the longitudinal direction. A rubber portion 5 containing a cushion 6 is provided in the groove portion of the upper metal fitting 3.

On the other hand, a lower metal fitting 7 which is an attachment member to the cross member 8 (body frame) is attached to this rubber part 5, and the upper end side of this lower metal fitting 7 is located at a position facing the cushion 6 with a slight gap. It is set in. Further, a rear mount cross member 8 is provided on the lower end side of the rubber portion 5. As shown in FIG. 1, the rubber portion 5, lower metal fitting 7, and rear mount cross member 8 are fixed together by tightening from below with rear mount isolator lower mounting bolts 9. ing.

Therefore, in such a structure, vibrations such as gear noise transmitted from the transmission extension housing 2, which is a vibrating body, are first transmitted to the upper metal fitting 3 of the rear mount insulator 1, which is a vibration-proof mounting device. However, this gear noise vibration is absorbed by the rubber portion 5, and in the case of normal vibration, the transmission of vibration energy to the lower metal fitting 7 is considerably reduced. However, if the level of the gear noise vibration is very high and the rigidity of the upper metal fitting 3 is weak, a problem may occur in which the vibration is amplified in a specific frequency range. In that case, although it is possible to obtain a certain degree of vibration isolation effect by increasing the rigidity of the upper metal fitting 3, increasing the rigidity of the upper metal fitting 3 too much may cause problems, or considering the shape of the upper metal fitting 3. In some cases, it may not be possible to increase the rigidity, and in such cases, it cannot be used as an effective anti-vibration measure.

Therefore, in this embodiment, in order to eliminate such inconvenience, the natural frequency of the upper metal fitting 3 is changed on both the front and rear outer surfaces of the pair of side members 3b of the upper metal fitting 3 of the rear mount insulator 1. A tuning mass element mounting bolt 11 and a lock nut type tuning mass element mounting nut 12 for preventing loosening are used to fix the tuning mass element 10.
It is attached by That is, this tuning mass element 10 has the frequency of the transmission extension housing 2, which is a vibrating body, and the natural frequency of the upper metal fitting 3, which is a supporting member that receives vibrations from the transmission extension housing 2. In order to prevent resonance from occurring and amplifying vibrations in a specific frequency range, the role of shifting the resonance point between the frequency of the transmission extension housing 2 and the natural frequency of the upper metal fitting 3 was determined. It is something.

Therefore, the tuning mass element 10 is carefully tuned to obtain an appropriate weight and distribution according to its assembled state. The tuning mass element 10 is preferably installed as low as possible on the side member 3b of the upper metal fitting 3; in that case, the tuning mass element 10 should be installed from the uppermost position of the upper metal fitting 3. As the distance to the position increases, the moment increases accordingly, so the lower the tuning mass element 10 is installed, the lighter the weight of the tuning mass element 10 can be.

As described above, in this embodiment, by attaching the tuning mass elements 10 to both the front and rear outer surfaces of the pair of side members 3b of the upper metal fitting 3 constituting the rear mount insulator 1, vibrations in a specific frequency range can be suppressed. As a result, most of the normal vibration energy is absorbed by the rubber part 5, and the transmission extension housing 2, which is a vibrating body, can be
The transmission of vibrations from the lower metal fitting 7 to the lower metal fitting 7 can be made extremely small. At the same time, the transmission of vibration to the ream mount cross member 8 is similarly reduced to an extremely low level, and the level of muffled sound inside the vehicle interior can also be kept to an extremely low level.

FIGS. 3A and 3B are graphs showing a comparison of the sound pressure levels in the vehicle interior of the present invention and the conventional technology when the vehicle is accelerating and decelerating, respectively, and the solid line indicates the conventional technology that does not use a tuning mass element. , the broken line shows the case of the present invention in which the tuning mass element 10 is provided. As is clear from these figures, when the tuning mass element 10 according to this embodiment is provided on the upper metal fitting 3, which is a supporting member, the sound pressure level in the vehicle interior is considerably reduced, and the sound pressure level in the vehicle interior is considerably reduced. It can be seen that the muffled noise inside the vehicle interior within the range can be reduced to a good level.

Further, in this embodiment, by fixing the tuning mass element 10 to the side member 3b along its longitudinal direction as described above, the rigidity against torsion in the longitudinal direction of the side member 3b can be increased.

Therefore, according to this embodiment, the frequency of the vibrating body in the horizontal direction (or left and right direction) and the characteristic of the upper metal fitting 3 can be reduced in the normal use range without increasing the weight of the upper metal fitting 3 and reducing the durability. The resonance point with the vibration frequency can be easily shifted.

In addition, in the above embodiment, an example was shown in which the anti-vibration mount device according to the present invention was applied as a rear mount insulator of a vehicle, but the present invention is not limited to only a rear mount insulator. For example, it can also be applied as a front mount insulator.

Further, in the above embodiment, the tuning mass element mounting bolt 11 and the lock nut type tuning mass element mounting nut 12 are used as the mounting method for the tuning mass element 10, and such a mounting method improves reliability. Although this is the most excellent method in terms of improving productivity and reducing equipment costs, other mounting methods such as adhesion or welding may also be used.

〔Effect of the invention〕

According to the present invention, the vibration support member that receives vibrations from the vibrating body is formed in the shape of an inverted gutter with an open bottom that integrally has a pair of side members hanging down from both sides of the vibrating body attachment part in the longitudinal direction. Since the tuning mass element is fixed to the side member along the longitudinal direction, the weight increase of the support member is suppressed, and the frequency of the vibrating body in the horizontal direction (or left and right direction) in the normal use range can be adjusted without reducing the durability and reliability. The resonance point with the natural frequency of the support member can be easily shifted. Furthermore, by fixing the tuning mass element to the side member along its longitudinal direction, the rigidity and strength against torsion in the longitudinal direction of the side member can be increased.

Therefore, it is possible to reduce the vibration level from the vibrating body to an extremely low level, and for example, it is possible to sufficiently reduce the muffled sound inside the vehicle interior in a general use area to a comfortable and good level without causing any problems. It is. Furthermore, in the present invention, by preventing resonance of the vehicle engine, transmission, etc., the amount of movement thereof can be suppressed to a small value, so that the durability of the vibration-proof mount device itself can be maintained for a sufficiently long time. It is possible.

[Brief explanation of drawings]

FIG. 1 is a side view of an embodiment of the anti-vibration mount device according to the present invention applied as a rear mount insulator of a vehicle, as seen from the left side of the vehicle, and FIG. 2 is a side view of the rear mount insulator of FIG. 1. Figures 3A and 3B are a partial cross-sectional view of the rotor along the - line in Figure 1 and seen from the rear, and Figures 3A and 3B compare the vibration damping effects of the present invention and the conventional technology when the vehicle is accelerating and decelerating, respectively. FIG. 4 is a perspective view schematically showing the state of the upper metal fitting, which is a vibration support member, and the tuning mass element fixed thereto. 1...Rear mount insulator, 2...Transmission extension housing,
3... Upper metal fitting, 4... Upper mounting bolt for rear mount insulator, 5... Rubber part, 7... Lower metal fitting, 8... Cross member for rear mount, 9...
Lower mounting bolt for rear mount insulator,
10... Tuning mass element, 11... Tuning mass element mounting bolt, 12... Tuning mass element mounting nut.

Claims (1)

[Claims] 1. A vibration-isolating mount device that supports a vibrating body such as a vehicle engine or transmission, with an open bottom that has a back surface attached to the vibrating body and integrally has a pair of side members that hang down from both sides of the mounting part in the longitudinal direction. an inverted gutter-shaped vibration support member;
an elastic member that is accommodated in the open groove of the support member and connects the side member and the attachment member to the body frame; A vibration-isolating mount device for a vehicle, characterized in that a tuning mass element is fixed to prevent the natural frequency of a support member from causing resonance.