JP2885541B2 - Method and apparatus for manufacturing liquid-filled bush - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a liquid-filled bush, and more particularly to a technique for advantageously manufacturing a bush-type automotive anti-vibration rubber filled with a highly viscous fluid as a liquid. .

[0002]

2. Description of the Related Art Various types of anti-vibration rubbers for automobiles, such as suspension bushes used for tension rods and buffer rod links, or body mounts and member mounts are used.
These dampen low-frequency, large-amplitude vibrations input during idling, sudden start, sudden stop, etc., and provide the two characteristics of blocking high-frequency, small-amplitude vibrations input from the engine or the road surface during running. Used in However, since these two properties are contradictory, simply using a rubber bush with a rubber elastic body between the inner cylinder and the outer cylinder gives such a vibration-proof rubber a performance that satisfies both properties. There was a limit. Therefore, in recent years, liquid-filled vibration damping rubbers have been proposed to satisfy the purpose (for example, Japanese Patent Publication No. 48-36151, Japanese Patent Publication No. 52-16554).
Issue publication).

[0003] In these liquid-filled type vibration damping rubbers, the two liquid chambers are communicated with each other by an orifice provided in an elastic body. Liquid flows through the orifice during that time, and the fluid flows through the orifice, whereby viscous resistance and inertia force act, giving high damping characteristics especially in the low frequency region. It will be. However, in the so-called liquid column resonance type liquid-filled vibration damping rubber based on these prior arts, however, stiffening occurs in a high vibration frequency region above the resonance point, and there is a problem in vibration insulation.

On the other hand, in the technique of vibration isolation at a high frequency, there is a method of providing vibration isolation by encapsulating a conventionally used silicone oil in a torsional damper or a mount-type anti-vibration rubber. In these, a viscous fluid such as silicone oil is sealed in a narrow gap, and vibration insulation is performed by the shear resistance (for example, Japanese Patent Publication No. 40-26).
No. 296 and Japanese Patent Publication No. 47-46305). According to the vibration damping method by enclosing the viscous fluid in these narrow portions, the rigidity of the vibration damping rubber in the high frequency region is prevented, and therefore, it is promising as a method for preventing the liquid-filled vibration damping rubber from becoming rigid.

[0005] When the liquid is sealed in the liquid-sealing type vibration damping rubber, the elastic coefficient of the vibration damping rubber is required when a gas (air) having compressive elasticity is mixed in the incompressible liquid. In general, in the liquid encapsulation process, a member constituting the bush is put in the liquid and assembled so that gas does not enter, or a bush assembly is put in a vacuum chamber, and a nozzle is externally provided with a nozzle. For example, liquid is injected into the cavity.

[0006]

As described above, if the assembling process includes a dipping process into a liquid or a depressurizing process, the operation is not easy compared with the operation in the atmosphere, and particularly, a highly viscous fluid is removed. When gas is sealed in the liquid chamber, it is easy for gas to enter.Therefore, problems such as degassing, removal of fluid adhering to metal fittings with solvent, drying after assembly, removal from the vacuum chamber, etc.
There are many issues in terms of labor, workability, efficiency, etc. Therefore, a method and an apparatus for manufacturing a liquid encapsulating bush, which can be operated in the atmosphere, has no fluid attached to the outer wall of the fitting, is easily sealed in the liquid chamber, and has no gas mixed into the liquid chamber, were studied.

[0007]

The above object has been attained by the following method and apparatus. That is, the method for manufacturing the liquid-enclosed bush includes a hollow portion having a cylindrical rubber elastic body 12 radially outside the inner shaft body 11 and opening outwardly of the rubber elastic body.
A cover closing step A in which the outside of the hollow portion of the bush body 10 in which the 13 is formed is liquid-tightly held by an outer wall, and while injecting liquid from the lowest level of the hollow portion 13 of the bush body held in a liquid-tight manner. Liquid injection process B to expel air from the highest level
And an air removal step C, and an introduction step D for introducing the bush body 10 into the outer cylinder 14 in a liquid-tight manner when the hollow portion 13 of the bush body is filled with liquid.

Further, the apparatus for manufacturing a liquid-filled bush according to the present invention has a cylindrical rubber elastic body 12 radially outside of an inner shaft body 11, and a hollow portion 13 opening outside the rubber elastic body 12. Means for keeping the outside of the cavity of the bush body 10 formed with the liquid-tight by the outer wall 7, and the liquid positioned at the lowest level of the cavity 13 of the bush body 10 held in a liquid-tight manner. Means 2 for injecting water, exclusion means 3 positioned at the highest level of the cavity 13 of the liquid-tightly maintained bush body 10 to expel air, and if necessary, the bushing which is liquid-tightly maintained. Detecting means 4 for detecting that the hollow portion 13 of the main body 10 is filled with the liquid is provided, and is disposed coaxially with the bush main body 10 which is maintained in a liquid-tight manner.
A guide means 5 for introducing the bush body 10 into the outer cylinder 14 in a liquid-tight manner when the bush body is filled with a liquid, and coaxially arranged with the bush body to form one cylinder in cooperation with the guide means. The bush body 10 and the holding means 6 for holding the outer cylinder 14 when the outer cylinder 14 is inserted into the bush body 10 and holding the outer cylinder 14 at a predetermined position on the inner peripheral surface thereof.

Further, the manufacturing method or the manufacturing apparatus includes:
An intermediate cylinder 15 coaxially disposed with the rubber elastic body 12 and the outer cylinder 14 is integrally fixed to a radially outer side of the inner shaft body 11, and a plurality of cavities opened outside the rubber elastic body 12. A portion 13 is provided at an axially intermediate portion of the elastic body, and a hollow portion 13 of the
A liquid chamber 17 when sealed between the cylinder 14 and the intermediate cylinder 15 with or without a rubber layer, and is configured to be communicated with the orifice 18 or the narrow gap. The manufacture of a bush assembly was also made possible.

[0010] By using such a method or apparatus for manufacturing a liquid-enclosed bush assembly, the liquid to be enclosed in the liquid chamber is not only a low-viscosity fluid having a kinematic viscosity of 50 cps or less,
For example, even with a silicone oil having a kinematic viscosity of 1000 cps or more, it has become possible to fill the fluid without mixing gas.

[0011]

According to the method or apparatus for manufacturing a liquid-enclosed bush assembly of the present invention, the liquid is injected from the lowest level into the cavity 13 of the bush body 10 which is kept liquid-tight in the closing step A in the injection step B. Then, the air is expelled from the cavity 13 in the elimination step C, and when the cavity is filled with the liquid, the air is introduced into the outer cylinder 14 with a pusher or the like. The gas in the room is completely exhausted. At this time, since the exclusion means 3 is at the position corresponding to the highest level of the cavity 13 and the injection means 2 is at the position corresponding to the lowest level of the cavity 13, when the liquid is injected, the air moves upward. , And are finally discharged to the outside. This simplifies the process, and provides a liquid-filled bush assembly having two characteristics of attenuating low-frequency large-amplitude vibration and blocking high-frequency small-amplitude vibration.

[0012]

1 is a sectional view of an apparatus for carrying out a method for manufacturing a liquid-filled bush assembly according to the present invention. This device holds an outer cylinder 14 for a bush assembly at a substantially intermediate portion between a cylindrical upper outer wall 7a as the closing means 1 and a base outer wall 7b as the holding means 6, and is provided inside the cylinder of the upper outer wall 7a. There is a packing 8 around the periphery to prevent liquid leakage. The bush main body has a cylindrical rubber elastic body 12 on the radially outer side of the inner shaft body 11, and a hollow portion 13 opened outside the rubber elastic body is formed,
The rubber elastic body is press-fitted into the cylindrical wall of the cylindrical upper outer wall 7a in a tightly contacted state to be liquid-tight. An injection path 2a is perforated as the liquid injection means 2 to the outermost wall 7a at the lowest level of the cavity 13 of the bush body 10 which is maintained in a liquid-tight manner as described above. Further, an air discharge passage 3a is provided as an exclusion means 3 which is located at the highest level of the hollow portion 13 and drives out air.
If necessary, an electric or mechanical sensor 4a operated by opening and closing a check valve as a detecting means 4 for detecting that the cavity 13 of the bush body 10 held in a liquid-tight manner is filled with liquid. Is provided. Alternatively, a capacitance type proximity switch can be used.

When the hollow portion 13 of the bush body is filled with the liquid, the bush body is press-fitted into the outer cylinder 14, and the guiding means 5 for that purpose is provided.
The press-fit pusher 5a is coaxially arranged at the upper part of the bush body 10, and when pressed by this, the bush body is tapered at the middle part of the cylindrical outer wall 7a as the closing means 1. And is introduced into the outer cylinder 14 in a liquid-tight manner. In order to introduce the bush body 10 into the outer cylinder 14 in a liquid-tight compression manner, the base outer wall 7b is used as holding means 6 for supporting the outer cylinder 14.
There is a portion in which the inner diameter of the cylinder is enlarged at the upper part of the. The base outer wall 7b and the upper outer wall 7a fitted and connected to the upper part thereof are combined to form one cylinder.

The production of the liquid-filled bush by such a device is performed in the following procedure. First, the outer cylinder 14 is held at the upper enlarged diameter portion of the base outer wall 7b, the upper outer wall 7a is united with the upper portion, and then the bush body 10 is inserted from the upper portion and the lowermost portion of the hollow portion 13 that opens outward. Is the liquid injection path 2a, and the top of the cavity 13 is the air discharge path 3a for purging air.
(See step A). Next, the liquid is injected from the lowest level of the cavity 13 of the bush body held in a liquid-tight manner.
(Liquid injection step B). Although the air is expelled by this injection (air elimination step C), the liquid can be simultaneously filled while expelling the air by suctioning the air discharge passage 3a from the outside. When the cavity 13 of the bush main body which is kept liquid-tight is filled with the liquid, the upper part of the bush main body 10 is further pushed by the press-fitting pusher 5a and introduced into the outer cylinder 14 (introduction step D). Thus, according to this method, it is possible to fill the cavity 13 with a liquid from a low-viscosity glycol to a high-viscosity silicone oil without gas being mixed.

FIGS. 2 and 3 are partial cross-sectional views of a liquid sealing bush manufactured by the manufacturing method and apparatus of the present invention.
The former has a cylindrical rubber elastic body 12 on the radial outside of the inner shaft body 11, and a hollow portion 13 opened to the outside of the rubber elastic body 12 has an outer cylinder.
A liquid chamber 17 is formed by coating with 14. There are usually two liquid chambers 17 on the diameter line, and a communication passage between the liquid chambers is formed as an orifice 18 between a groove on the outer periphery of the rubber elastic body and the outer cylinder 14. In the latter one shown in FIG. 3, a rubber elastic body 12 and an intermediate cylinder 15 are integrally fixed coaxially with the outer cylinder 14 on the radially outer side of the inner shaft body 11. The cavity 13 that opens toward the liquid chamber is covered when sealed between the outer cylinder 14 and the intermediate cylinder 15 with or without a rubber layer.
It has become 17. Orifice 18 as communication passage between liquid chambers
3, is formed between the intermediate cylinder 15 and the outer cylinder 14, in a rubber elastic body, or in the inner shaft body 11, as shown in FIG.

[0016]

As described above, according to the present invention, the assembling with the outer cylinder following the injection of the liquid into the bush body can be easily performed in the atmosphere without immersing the liquid in the liquid or reducing the pressure. This simplifies the process, thereby streamlining the production of a liquid-filled bush assembly having two characteristics of attenuating low-frequency, large-amplitude vibration and blocking high-frequency, small-amplitude vibration without introducing gas. Was achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an apparatus for carrying out a method of manufacturing a liquid-filled bush assembly according to the present invention.

FIG. 2 is an axial cross-sectional view of a liquid sealing bush manufactured by the manufacturing method and apparatus according to the present invention, in the X and Y planes perpendicular to the axis.

FIG. 3 is an axial cross-sectional view of a liquid sealing bush having an intermediate cylinder manufactured by the manufacturing method and apparatus of the present invention, in the X-Y plane perpendicular to the axis.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Covering means 2 Injecting means 2a Injecting path 3 Excluding means 3a Air discharging path 4 Detecting means 4a Sensor 5 Guide means 6 Holding means 7a Upper outer wall 7b Lower outer wall 10 Bush body 11 Inner shaft body 12 Rubber elastic body 13 Cavity part 14 Outside Tube 15 Intermediate tube 18 Orifice

Claims (2)

(57) [Claims] 1. A hollow portion of a bush body 10 having a cylindrical rubber elastic body 12 on a radially outer side of an inner shaft body 11 and having a hollow portion 13 opened to the outside of the rubber elastic body. An enclosing step A in which the outer wall is kept liquid-tight, a liquid injecting step B in which liquid is injected from the lowest level of the hollow portion 13 of the bush body kept liquid-tight and air is expelled from the highest level while removing air. In step C, when the cavity 13 of the bush body held in a liquid-tight state is filled with liquid, the bush body 10 is
14. A method for producing a liquid-filled bush, comprising: an introduction step D for introducing the liquid-tight bush into the inside of 14. 2. A hollow rubber member (12) having a cylindrical rubber elastic body (12) radially outside the inner shaft body (11), and opening outside the rubber elastic body (12).
The outside of the hollow portion of the bush body 10 in which the
A closing means 1 for holding the liquid tightly, an injecting means 2 for injecting a liquid at the lowest level of the hollow portion 13 of the bush body 10 held liquid tight, The expulsion means 3 which is located at the highest level of the hollow portion 13 of the bush body 10 to expel air, and which is disposed coaxially with the bush body 10 which is maintained in a liquid-tight manner, and the hollow portion 13 of the bush body When the bush body 10 is filled with
A guide means 5 for introducing liquid-tight into the inside, and arranged coaxially with the bush body, forming a single cylinder in combination with the guide means, and positioning the outer cylinder 14 at a predetermined position on its inner peripheral surface. An apparatus for manufacturing a liquid-filled bush, comprising holding means 6 for holding and supporting the bush main body 10 and the outer cylinder 14 when inserting them.