JP3563456B2 - Anti-vibration device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a vibration isolator applied to, for example, an automobile, a general industrial machine, and the like, which absorbs vibration from a vibration generating unit, and particularly to a vibration isolator having an outer cylinder portion formed of a resin molded product.
[0002]
[Prior art]
For example, in a vehicle, a vibration isolator as an engine mount is disposed between an engine serving as a vibration generating unit and a vehicle body serving as a vibration receiving unit, and the vibration generated by the engine is absorbed by the vibration isolator. , So that it is prevented from being transmitted to the vehicle body.
[0003]
As this kind of vibration isolator, a bush type vibration isolator of a liquid filling type is used. In a bush-type vibration isolator, a rubber-like elastic body (and an intermediate cylinder) is vulcanized and bonded to the outer periphery of the inner cylinder, and inserted into the outer cylinder to prevent slipping and sealing. The end of the tube is drawn. After attaching the inner cylinder, the outer cylinder is press-fitted into a mounting bracket and attached to the vehicle body.
[0004]
In recent years, there has been a demand for a reduction in the number of parts, a reduction in the number of assembling steps, a reduction in weight, and the like.
[0005]
For example, a vibration isolator in which an outer cylinder and a mounting bracket are integrated has been proposed by the present applicant (Japanese Patent Application No. 5-306684).
[0006]
In this anti-vibration device, an elastic body provided with an inner cylinder fitting is arranged in a mold, and a resin is injection-molded on the outer peripheral side to integrate an inner cylinder, an elastic body, and an outer cylinder integrated with a mounting bracket. In addition, the number of parts and the number of assembly steps are reduced compared to the conventional vibration isolator.
[0007]
[Problems to be solved by the invention]
However, since the outer periphery of the elastic body is covered with resin, a groove is provided on the outer periphery of the elastic body as in a vibration isolator having a structure before resinification of the outer cylinder, and the orifice is covered by covering the groove with the outer cylinder. The opening cannot be formed, and an opening is formed in the outer cylinder, and a partition member for forming an orifice is inserted from the opening toward the recess of the elastic body.
[0008]
For this reason, there is a limit in increasing the opening area of the opening, and it has been difficult to form a long orifice by enlarging the partition member.
[0009]
An object of the present invention is to provide a vibration isolator capable of forming a long orifice in consideration of the above fact.
[0010]
[Means for Solving the Problems]
The present invention provides an outer cylinder connected to one of the vibration generator and the vibration receiver and integrally formed of resin, and an outer cylinder connected to the other of the vibration generator and the vibration receiver and arranged inside the outer cylinder. An inner cylinder, an elastic body disposed between the outer cylinder and the inner cylinder so as to connect between the outer cylinder and the inner cylinder, and at least a part of an inner wall is formed by the elastic body. Pressure-receiving liquid chamber, a sub-liquid chamber provided at a position circumferentially separated from the pressure-receiving liquid chamber and partially formed of an elastic film, and a restriction passage connecting the pressure-receiving liquid chamber and the sub-liquid chamber. Wherein the restriction passage is a plate-shaped member that is interposed between the elastic body and the outer cylinder and the elastic body and is curved along the outer periphery of the elastic body. At least one of the recesses is closed by an opposing partner. There.
[0011]
[Action]
In this vibration isolator, the restriction passage formed between at least one of the elastic body and the plate-shaped member interposed between the outer cylinder and the elastic body and curved along the outer periphery of the elastic body is opposed to the counterpart. It is configured to be closed by the side. That is, when a groove-like concave portion is formed on the outer peripheral surface of the elastic body and the concave portion is closed by the plate-like member to form a restricted passage, a groove-like concave portion is formed on the elastic body side of the plate-like member. When this concave portion is closed by the outer peripheral surface of the elastic body to form a restriction passage, a groove-like concave portion is formed on both the outer peripheral surface of the elastic body and the elastic body side of the plate-like member, and both concave portions are formed. There may be a case where a restriction passage is formed to face the passage. Therefore, according to this vibration isolator, a space for providing the restriction passage between the elastic body and the outer cylinder can be secured, so that the restriction passage can be made long, and the damping caused by the liquid passing through the restriction passage can be obtained. It is possible to increase the power.
[0012]
【Example】
1 to 6 show an anti-vibration device according to an embodiment of the present invention, and the present embodiment will be described based on these drawings.
[0013]
As shown in FIG. 1, a vibration isolator 10 of the present embodiment includes an outer cylinder 12 of a bracket integrated type integrally formed of a synthetic resin, and a vehicle body (not shown) as a vibration receiving portion. ), The outer cylinder 12 is screwed using an embedding nut 13 fixed to an arm 12A protruding from one side of the outer cylinder 12. Therefore, the outer cylinder 12 is connected to the vehicle body. As shown in FIGS. 1 and 2, an inner tube fitting 14 formed in a tubular shape is arranged inside the outer tube 12 so as to be parallel to the axis of the outer tube 12. When an unillustrated bolt is screwed in, the inner cylinder fitting 14 is connected to an engine (not shown) serving as a vibration generating unit.
[0014]
An elastic body 16 made of rubber is provided between the inner tube fitting 14 and the outer tube 12.
[0015]
As shown in FIGS. 3 and 4, the elastic body 16 is formed into a cylindrical shape which is vulcanized and adhered to the outer peripheral surface of the inner cylindrical member 14. Is formed with a concave portion 18. On the opposite side of the concave portion 18 with the inner cylinder fitting 14 interposed therebetween, a through-hole 20 having a cross-section of a letter-like shape penetrating in the axial direction is formed. The metal fitting 14 is easily displaced.
[0016]
On the outer periphery of the elastic body 16, a groove 22 is formed at a middle portion in the axial direction as a concave portion extending along the outer peripheral direction. One of the grooves 22 is connected to the recess 18, and the other is connected to a small recess 24 formed on the opposite side of the inner tube fitting 14. The elastic body 16 between the small recess 24 and the through hole 20 is a diaphragm 26 as a thin elastic film.
[0017]
Further, a wide shallow groove 28 which is continuous in the circumferential direction is formed at an intermediate portion in the axial direction of the elastic body 16. Into the shallow groove 28, a resin inflow prevention cover 30 as a cylindrical plate-like member as shown in FIG. 5 is inserted from the axial direction, which covers the opening on the outer peripheral side of the concave portion 18, the groove 22, and the small concave portion 24. It is fitted. The resin inflow prevention cover 30 is formed by cutting a metal round pipe into a predetermined length, and has a split 31 along an axis, which facilitates insertion by being pushed out from the inside. . After the insertion, the resin inflow prevention cover 30 elastically returns and comes into close contact with the elastic body 16.
[0018]
The shallow groove 28 has small projections 32 continuous in the circumferential direction as shown in FIGS. 3 and 4 in order to enhance the sealing performance with the inner peripheral surface of the resin inflow prevention cover 30. It is formed on both axial sides of the small recess 24.
[0019]
As shown in FIGS. 1 and 2, the recess 18 is closed by a resin inflow prevention cover 30 to form a main liquid chamber 34 as a pressure receiving liquid chamber, and the groove 22 is closed by the resin inflow prevention cover 30 to serve as a restriction passage. And the small recess 24 is closed by the resin inflow prevention cover 30 to form the sub liquid chamber 38. Therefore, the orifice 36 communicates between the main liquid chamber 34 and the sub liquid chamber 38.
[0020]
Here, the outer peripheral surface of the resin inflow prevention cover 30 and the outer peripheral surface of the elastic body 16 not covered by the resin inflow prevention cover 30 are adhered to the inner peripheral surface of the outer cylinder 12.
[0021]
The main liquid chamber 34, the orifice 36 and the sub liquid chamber 38 are filled with a liquid 40 such as water or oil. The liquid 40 is injected from an injection port 42 that penetrates the outer cylinder 12 and the resin inflow prevention cover 30, and is sealed with a rivet 44 after the injection.
[0022]
Next, assembly of the vibration isolator 10 according to the present embodiment will be described.
At the time of assembling the vibration isolator 10, the elastic body 16 is vulcanized and bonded around the inner tube fitting 14 to obtain a state as shown in FIGS.
[0023]
Next, the resin intrusion prevention cover 30 is inserted into the shallow groove 28 of the elastic body 16 from the axial direction to obtain a state as shown in FIG. Since the elastic body 16 can be elastically deformed, the insertion of the resin inflow prevention cover 30 is easy.
[0024]
Next, the elastic body 16 and the embedding nut 13 fitted with the resin inflow prevention cover 30 are loaded at predetermined positions in a mold (not shown) for molding the outer cylinder, and the molten synthetic resin is injected into the mold. Thereby, the synthetic resin is adhered to the outer periphery of the elastic body 16 and the resin inflow prevention cover 30, and the outer cylinder 12 integrated with the elastic body 16 and the resin inflow prevention cover 30 is formed.
[0025]
After that, the outer cylinder 12 is removed from the mold, a predetermined liquid is injected into the inside through the injection port 42, and the liquid is sealed with the rivets 44, thereby completing the assembly of the vibration isolator 10.
[0026]
The outer cylinder 12 of the vibration isolator 10 thus completed is screwed and connected to the vehicle body side of the automobile, and the inner cylinder fitting 14 is connected to the engine via bolts. When the vibration isolator 10 is incorporated into a vehicle body, a force due to the load of the engine is applied to the inner cylinder 14, so that the inner cylinder 14 is substantially coaxial with the outer cylinder 12.
[0027]
Next, the operation of the present embodiment will be described.
When the vibration of the engine is transmitted to the inner tube fitting 14, the elastic body 16 is deformed and the main liquid chamber 34 expands and contracts, and the vibration is attenuated by the resistance when the liquid 40 flows through the orifice 36.
[0028]
When assembling the vibration isolator 10, the outer cylinder 12 is formed of a resin material, but the concave portion 18, the groove 22, and the small concave portion 24 formed on the outer peripheral portion of the elastic body 16 are covered by the resin inflow prevention cover 30. Since the resin material is covered, these concave portions are not filled with the resin material when the resin material is injected, so that the main liquid chamber 34, the sub liquid chamber 38, and the orifice 36 can be obtained.
[0029]
As described above, in the vibration isolator 10 of the present embodiment, the diaphragm 26 is formed integrally with the elastic body 16 as a part, and the main liquid chamber 34, the sub liquid chamber 38 and the orifice 36 prevent the resin from flowing into the elastic body 16. Since it is formed between the cover 30 and the cover 30, there is no need for a partition member, an orifice forming member, a diaphragm, and the like, which are necessary for the conventional vibration isolator, to separate the main liquid chamber and the sub liquid chamber. Since these parts are not assembled later, the number of parts and the number of assembling steps can be reduced.
[0030]
Furthermore, the vibration isolator 10 of the present embodiment does not necessarily insert the orifice forming member from the outside after resin molding as in the conventional vibration isolator, but has a configuration in which the outer peripheral surface of the elastic body 16 can be used freely. Therefore, the length of the orifice 36 can be increased, and the attenuation rate can be increased by bending the orifice 36 or making a U-turn.
[0031]
As shown in FIG. 9, a metal elastic body deformation preventing ring 50 may be embedded in the elastic body 16 such that a part of the resin inflow preventing cover 30 is in close contact with both ends. Thereby, deformation of the elastic body 16 due to pressure during resin molding can be suppressed, and it is ensured that the resin enters the groove 22, the small recess 24, and the recess 18 from between the resin inflow prevention cover 30 and the elastic body 16. Can be prevented.
[0032]
Further, in the vibration isolator 10 of the embodiment, the arm 12A is integrally provided on one side of the outer cylinder 12, but the outer cylinder 12 is integrally provided with mounting portions 12B protruding on both sides as shown in FIG. It may be provided in some way.
[0033]
Further, in the above-described embodiment, the resin inflow prevention cover 30 is formed by cutting a metal round pipe, but the split 31 may be omitted if the elastic body 16 can be easily inserted. Further, the resin inflow prevention cover 30 may be formed by cutting a round pipe along an axis to be divided into two parts, or by combining two semi-circular plate members into a pipe shape.
[0034]
Further, in the above embodiment, the groove 22 is provided in the elastic body 16 and the orifice 36 is formed by covering the groove 22 with the resin inflow prevention cover 30. However, the present invention is not limited to this, and as shown in FIG. The groove 22 may not be provided, and the orifice 36 may be formed by providing a concave portion 30A as a concave portion in the resin inflow prevention cover 30. Although not shown, the elastic member 16 has a concave portion 30A of the resin inflow prevention cover 30 in the groove 22. May be opposed to each other to form the orifice 36.
[0035]
Further, in the above-described embodiment, the outer cylinder 12 is connected to the vehicle body serving as the vibration receiving unit, and the inner cylinder fitting 14 is connected to the engine side serving as the vibration generating unit. good.
[0036]
Further, in the above embodiment, the inner cylinder is made of a metal fitting, but may be made of resin. Further, as the type of the resin material used in the above embodiment, ABS, polyacetal, etc. are considered, but are not limited thereto. Not something.
[0037]
On the other hand, in the embodiment, the purpose is to dampen an engine mounted on an automobile. However, it goes without saying that the anti-vibration device of the present invention can be used for, for example, a body mount of an automobile or other uses other than an automobile. Also, the shape and dimensions of the elastic body, the stopper and the like are not limited to those of the embodiment.
[0038]
【The invention's effect】
As described above, the anti-vibration device of the present invention has the above-described configuration, so that it is possible to generate a large damping force by lengthening the orifice, and it is possible to reduce the number of assembly steps. Having.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view perpendicular to an axis showing a vibration isolator according to one embodiment of the present invention.
FIG. 2 is a sectional view taken along line 2-2 of the vibration isolator shown in FIG.
FIG. 3 is a cross-sectional view perpendicular to an axis showing the elastic body before the outer cylinder is assembled.
FIG. 4 is a side view of the elastic body before being incorporated into the outer cylinder.
FIG. 5 is a side view of a resin inflow prevention cover.
FIG. 6 is a side view of an elastic body to which a resin inflow prevention cover is attached.
FIG. 7 is a cross-sectional view perpendicular to an axis showing a vibration isolator according to another embodiment of the present invention.
FIG. 8 is a sectional view taken along an axis showing a vibration isolator according to still another embodiment of the present invention.
FIG. 9 is a sectional view along an axis showing a vibration isolator according to still another embodiment of the present invention.
[Explanation of symbols]
10 Vibration isolator 12 Outer tube 14 Inner tube fitting (inner tube)
16 elastic body 22 groove (concave part)
26 Diaphragm (elastic membrane)
30 Resin inflow prevention cover (plate-like member)
30A recess (recess)
34 Main fluid chamber (pressure receiving fluid chamber)
36 orifice (restricted passage)
38 Secondary liquid chamber

Claims (1)

An outer cylinder connected to one of the vibration generating unit and the vibration receiving unit and integrally molded with resin;
An inner cylinder connected to the other of the vibration generator and the vibration receiver and arranged inside the outer cylinder;
An elastic body disposed between the outer cylinder and the inner cylinder so as to connect between the outer cylinder and the inner cylinder;
A pressure-receiving liquid chamber in which at least a part of the inner wall is formed by the elastic body,
The pressure-receiving liquid chamber is provided at a position separated in the circumferential direction and a part of the auxiliary liquid chamber is formed of an elastic film,
A restriction passage connecting the pressure receiving liquid chamber and the sub liquid chamber,
A vibration isolator provided with
The restriction passage is opposed to the elastic body and a recess formed in at least one of a plate-shaped member interposed between the outer cylinder and the elastic body and curved along the outer periphery of the elastic body. An anti-vibration device characterized by being closed by a partner.

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