JPH09273596A - Vibration-proofing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin made vibration-proofing device for sufficiently reducing and regulating the number of fixed vibration as a whole of a vibration system without enlarging the whole of the device extremely by directly fixing a metal body for regulating a mass on a first installing member. SOLUTION: A cylindrical part 11c formed on the inner side of a resin made bracket 11 formed such as a first installing member is connected to an inner cylinder 13 formed as a second installing member through an elastic body 12. An installing hole 19 is arranged on the bracket 11, an engine is fixed on the bracket 11 by a bolt and the like, and also the inner cylinder 13 is fixed to a car body member. A plurality of locking parts 11B erected in an axial outer direction are arranged integratedly with the bracket 11 on the outer peripheral surface of the bracket 11, a metal mass body 14 is fitted to a locking part 11A so as to surround by the locking part 11B, and the metal mass body 14 is fixed on the outer peripheral surface of the bracket 11. It is thus possible to constitute a damper mass serving the elastic body 12 as a spring element and a damping element, and serving a part by which the elastic body 12 is held as a mass body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device, for example, a vibration damping device suitable for use as an engine mount for a vehicle for damping vibrations from an engine.

[0002]

2. Description of the Related Art Heretofore, as this type of engine mount, there has been known an engine mount constructed by press-fitting and fixing an anti-vibration bush inside a tubular portion of a metal bracket. As this anti-vibration bush, one in which a metal inner cylinder is arranged inside a metal outer cylinder and the inner and outer cylinders are connected by an elastic body such as rubber is usually used. The bracket and the metal outer cylinder are attached as one mounting member to the engine side which is the vibration generating portion, and the metal inner cylinder is attached as the other mounting member to the vehicle body side which is the vibration receiving portion. Mount is used.

However, in recent years, in response to the demand for cost reduction of the device, a vibration damping device in which at least one of the mounting members is made of a resin material (hereinafter referred to as "resin vibration damping device") is proposed. Has been done.

An example of this type of vibration isolator is shown in FIG. As shown in FIG. 5, in the engine mount 100, which is a resin vibration isolator, the elastic body 12 is provided between the tubular resin bracket 110 and the metal inner cylinder 130 arranged therein.
It is connected by 0. The resin bracket 110 is provided with a mounting hole 190, and the resin bracket 110 is fixed to an engine (not shown) by a bolt or the like.
The inner cylinder 130 is fixed to a member of the vehicle body. Such an engine mount 100 is manufactured as follows. First, the elastic body 120 is integrally molded on the outer circumference of the inner cylinder 130 by vulcanization adhesion. Next, the inner cylinder 130 and the elastic body 12
The assembly consisting of 0 is installed in a mold cavity for forming the resin bracket 110. Next, the resin material constituting the resin bracket is changed to the resin bracket 1
(10) The engine mount 100 is obtained by injection-flowing into a molding die cavity and molding the same with the above assembly. Therefore, the step of press-fitting the outer cylinder into the bracket becomes unnecessary.

[0005]

According to the vibration isolator as described above, the cost can be reduced by simplifying the manufacturing method. On the other hand, on the other hand, a metal outer member as a conventional mounting member for an engine is used. Compared to a combination of a cylinder and a metal bracket, the weight of the mounting member is extremely light because the outer cylinder is abolished and the bracket is made of resin. Therefore, when the mounting member and the engine mounted on the mounting member are regarded as a mass body, the natural frequency of the entire vibration system increases significantly. This is because when the mass of the mass body in the vibration system is M, the spring constant of the elastic body is K, and the natural frequency is f, the following formula is obtained.

[0006]

[Equation 1] In this case, the vibration transfer characteristic is generally improved, but the natural frequency of another vibration transfer system may be matched with the increased natural frequency depending on the vehicle, which may further deteriorate the vibration transfer characteristic. In this case, it is necessary to adjust and reduce the natural frequency.

On the other hand, in order to reduce the natural frequency, as is clear from the above equation, it is conceivable to reduce the spring constant of the elastic body or increase the weight of the bracket which is the mounting member. Since the material, shape, size, etc. of the body are determined from its strength, durability, damping characteristics, etc., it is difficult to change the spring constant unnecessarily in order to adjust the natural frequency. Also, since the bracket is made of resin, if the weight of the bracket is to be increased so that the mass of the mass body as a whole can be sufficiently increased, it is unavoidable to make it extremely large. I will end up.

Therefore, an object of the present invention is to provide a resin vibration isolator capable of sufficiently reducing and adjusting the natural frequency of the entire vibration system without making the entire apparatus extremely large.

[0009]

A vibration isolator according to a first aspect of the present invention comprises a first attachment member and a second attachment member which are attached to one or the other of the vibration generating portion and the vibration receiving portion, respectively. An elastic body that connects the first mounting member and the second mounting member, and at least the first mounting member of the first mounting member and the second mounting member is made of a resin material. The vibrating device is characterized in that a metal body for mass adjustment is directly fixed to the first mounting member.

A vibration isolator according to a second aspect is characterized in that the metal body is fixed to the first mounting member by exposing at least a part of the surface thereof.

The vibration isolator according to claim 3 is characterized in that the metal body is detachably fixed to the first mounting member.

A vibration isolator according to a fourth aspect is characterized in that the metal body is embedded inside the first mounting member.

According to a fifth aspect of the invention, in the vibration isolator, the first mounting member is formed as a first cylindrical body, and the second mounting member is arranged inside the first cylindrical body. It is characterized by being formed as a tubular body of No. 2.

According to the invention of claim 1, since the metal body for mass adjustment is directly attached to the first mounting member, the mass of the first mounting member is sufficiently increased without making the size of the first mounting member extremely large. Can be made larger, and the material, shape, and
By appropriately selecting the size, the mass of the first mounting member can be set arbitrarily.

According to the second aspect of the present invention, since the metal body is fixed to the first mounting member with at least a portion of its surface exposed, the first mounting member and the metal body are formed by injection molding of a resin material. In the case of integral molding, since it is not necessary to float the metal body in the mold cavity and the exposed portion may be directly installed in the mold, a complicated mold device is not required.

According to the third aspect of the present invention, the metal body can be freely attached to and detached from the first mounting portion. Therefore, even after the vibration isolator is once manufactured, only the metal body is changed to easily change the first body. The mass of the mounting member 1 can be adjusted.

According to the fourth aspect of the invention, since the metal body is embedded inside the first mounting member, the metal body is covered with the resin material, so that the metal body can be prevented from falling off and its corrosion can be suppressed. .

According to the invention of claim 5, the first mounting member is formed as a first cylindrical body, and the second mounting member is the first cylindrical member.
Since it is formed as the second tubular body disposed inside the tubular body, a so-called bush type vibration damping device is realized.

[0019]

1 is a cross-sectional view showing a first embodiment of an engine mount which is a vibration isolator according to the present invention. The engine mount 10, which is a vibration isolation device, is a device that isolates vibrations from, for example, an automobile engine,
An elastic body 12 connects between the inner cylindrical portion 11C of the resin bracket 11 which is the first mounting member and the inner cylinder 13 which is the second mounting member. An attachment hole 19 is provided in the resin bracket 11, and an engine (not shown) is fixed to the resin bracket 11 with bolts and the like, and the inner cylinder 13 is fixed to a member of the vehicle body. Further, a plurality of locking portions 11B that stand upright in the axial direction are provided integrally with the resin bracket 11 on the outer periphery of the resin bracket 11, and the metal body is surrounded by these locking portions 11B. The metal mass 14 which is
It is fixed to the outer peripheral surface of the resin bracket 11.

The engine mount 10 as described above is manufactured as follows. First, the elastic body 12 is integrally molded on the outer periphery of the inner cylinder 13 which is a mounting member by vulcanization adhesion, and an assembly composed of the inner cylinder 13 and the elastic body 12 is manufactured in advance. Next, the assembly and the metal mass body 14 are placed at a predetermined position in the resin molding die, that is, the resin bracket 11
Installed in the cavity for the formation of. From this state, a resin material such as a thermoplastic resin is injected into the mold and allowed to flow into the cavity of the resin bracket portion 11 to mold the resin bracket 11. In this way, the assembly and the metal mass body are integrally molded with the resin bracket, and the engine mount 10 in which the resin bracket 11 and the metal mass body 14 are integrally fixed is obtained.

Furthermore, only the above-mentioned assembly is installed in a cavity for forming the resin bracket 11, and a resin material such as a thermoplastic resin is injected into a mold to obtain the resin bracket portion. 11 is made to flow into the cavity to mold the resin bracket 11, and the intermediate body integrally molded with the assembly and the resin bracket 11 is demolded from the mold, and the metal mass body 14 manufactured in advance is made of resin. Bracket 1
The space surrounded by the locking portion 11A of FIG. The metal mass 1 on the jaw 11B.
It is possible that the four step portions 14A are snap-fitted and locked, and the resin bracket 11 and the metal mass body 14 are integrally fixed to each other.

In this case, the metal mass body 14 is fixed by the locking portion 11A integrally provided on the resin bracket 11, but the resin bracket 11 without the locking portion 11A is formed and its outer peripheral surface is formed. Metal mass 1 at a predetermined position
4 may be fixed by an adhesive, a pressure sensitive adhesive or the like.

Next, the operation of the present embodiment will be described. In this embodiment, the elastic body 12 in the engine mount 10 is used as a spring element and a damping element, and the damper mass is configured with a portion sandwiching the elastic body 12 as a mass body to be formed of resin. The mass of the bracket portion 11 can be adjusted by fixing the metal mass body 14 to adjust the natural frequency of the mass body constituent portion to a desired value. That is, when the metal mass 14 having an appropriate mass is fixed to the surface portion of the resin bracket 11 that constitutes a part of the mass body, the mass of the mass body including the bracket 11 and the engine fixed to the bracket 11 becomes a desired value. The natural frequency in this vibration system can be adjusted to a desired value without changing the spring constant of the elastic body. In particular, in the case where the metal mass body 14 is detachable, the metal mass body 14 can be replaced and changed even after the engine mount 10 is once manufactured. Therefore, the mass of the resin bracket 11 can be more easily changed. Can be adjusted, and versatility is enhanced.

This will be described with reference to the curve of the vibration transmissibility with respect to the vibration frequency as shown in FIG. The one using a bracket (dashed line) has its natural frequency on the high frequency side, that is, 30
Slide from near 0 Hz to around 500 Hz. Even if the resin bracket is changed in shape to have a higher rigidity, the natural frequency of the resin bracket hardly changes. When the bracket is made of resin, the natural frequency of the vibration system that uses the bracket and the engine fixed to the bracket as a mass body matches the natural frequency of the member of the vehicle body to which the inner cylinder is fixed. In such a case, resonance is caused and the vibration transmission characteristic is deteriorated.
By selecting, the frequency curve is moved to the curve (dotted line) of the engine mount 10 to which the present invention is applied, that is, the natural frequency is moved, so that deterioration of the vibration transmission characteristic can be avoided. Thus, according to the present invention, depending on how the engine mount 10 is applied,
The mass member 14 having an appropriate mass is attached to the resin bracket 1
By making it integral with 1, the bracket can be used optimally. The reason why the vibration transmissibility is lower in the case of using the metal bracket near 300 Hz is that the resin itself has a slight elasticity.

Next, the engine mount 10 according to the present invention.
2 is shown in FIG. 2, and the embodiment will be described based on this figure. The same members as those described in the first embodiment are designated by the same reference numerals, and the duplicated description will be omitted.

As shown in FIG. 2, according to the present embodiment,
When the metal mass body 14 is inserted into the space surrounded by the locking portion 11A of the resin bracket 11 as described in the manufacturing method in the description of the first embodiment, the jaw portion 11 is formed.
The step portion 14A of the metal mass body 14 is snap-fitted and locked to B, and the resin bracket 11 and the metal mass body 14 are integrally fixed to each other.

Next, the engine mount 10 according to the present invention.
3 shows a third embodiment of the present invention, and the embodiment will be described based on this drawing. The same members as those described in the first embodiment are designated by the same reference numerals, and the duplicated description will be omitted. Such an engine mount 10 is manufactured as follows. First, the elastic body 12 is integrally molded on the outer periphery of the inner cylinder 13 which is a mounting member by vulcanization adhesion, and an assembly composed of the inner cylinder 13 and the elastic body 12 is manufactured in advance. Next, the assembly and the metal mass body 14 are placed at a predetermined position in the resin molding die, that is, the resin bracket 11
Installed in the cavity for the formation of. From this state, a resin material such as a thermoplastic resin is injected into the mold and allowed to flow into the cavity of the resin bracket portion 11 to mold the resin bracket 11. In this way, the assembly and the metal mass body are integrally molded with the resin bracket, and the engine mount 10 in which the resin bracket 11 and the metal mass body 14 are integrally fixed is obtained.

In the engine mount 10 thus obtained, the metal mass body 14 is covered with the resin material of the resin bracket, so that the metal mass body 14 is covered with the metal mass body 14. In this way, the rust prevention effect is obtained without being affected by the atmosphere around the engine and without being corroded at all.

In the vibration isolator of the present invention, as described in the above embodiment, the first mounting member is the resinous bracket 11 of the tubular member, and the second mounting member is the inner cylinder 13 of the tubular member. As described above, the first type of mounting member is a plate-shaped member and the second type of mounting member is also a plate-shaped member. A vibration isolation device of a type in which the spaces are connected by an elastic body may be used.

[0030]

According to the present invention as described above,
It is possible to provide a resin vibration damping device that can sufficiently reduce and adjust the natural frequency of the entire vibration system without making the entire device extremely large.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a vibration isolator according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of a vibration isolation device according to the present invention.

FIG. 3 is a sectional view showing a third embodiment of a vibration isolator according to the present invention.

FIG. 4 is a diagram showing a graph showing an example of a vibration isolation performance of a vibration isolation device.

FIG. 5 is a sectional view of a conventional vibration isolator.

[Explanation of Codes] 10, 100 Vibration Isolator 11, 110 Resin Bracket 11A Locking Part 11B Resin Bracket Jaw 11C Cylindrical Part 11D Resin Bracket Cover 12,120 Elastic Body 13,130 Inner Cylinder 14 Metal Mass Body 14A Metal mass Body step 19,190 Mounting hole

Claims (5)

[Claims] 1. A first mounting member and a second mounting member which are respectively mounted on one or the other of the vibration generating portion and the vibration receiving portion, and the first mounting member and the second mounting member are connected to each other. A vibration isolator, wherein at least a first mounting member of the first mounting member and the second mounting member is formed of a resin material. An anti-vibration device having a metal body for mass adjustment directly fixed thereto. 2. The vibration isolator according to claim 1, wherein the metal body is fixed to the first mounting member by exposing at least a part of the surface of the metal body. 3. The vibration isolator according to claim 2, wherein the metal body is detachably fixed to the first mounting member. 4. The vibration isolator according to claim 1, wherein the metal body is embedded inside the first mounting member. 5. The first mounting member is formed as a first tubular body, and the second mounting member is formed as a second tubular body disposed inside the first tubular body. The anti-vibration device according to claim 1, wherein the anti-vibration device is provided.