JPH06300079A - Liquid-filled vibration control device - Google Patents

Abstract

PURPOSE:To secure the airtightness of an air chamber provided in the back of an auxiliary liquid chamber easily at low cost by forming an airtight seal part in the lower surface of a head part of a bolt member, which abuts on the surface of a bottom plate of the outer peripheral surface of a shaft part of the bolt member passing through the bottom plate. CONSTITUTION:A bolt member 6 is projected so that the all circumference of the outer peripheral edge of the lower surface of a head part 62 thereof, which abuts on the inner surface of a bottom plate 4, has a wedge-like cross section to form an airtight seal part 63. Under the condition that a shaft part 61 formed with a screw groove in the outer periphery thereof is pressed into a through hole 41 formed at the center of the bottom plate 4, the airtight seal 63 as a part of the bolt member having a large rigidity bites the inner surface of the bottom plate 4. Even in the case where a clearance is generated between the outer periphery of the shaft part 61 of the bolt member 6 and the inner periphery of the through hole 41 of the bottom plate 4, the clearance is sealed by the airtight seal part 63, which bites the inner surface of the bottom plate 4, to secure the airtightness of an air chamber C. Necessity for providing a spacer like a conventional case is thereby eliminated to simplify the structure and reduce a cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid filled vibration damping device,
In particular, the present invention relates to a structural improvement of a liquid-filled vibration isolator that simply ensures the airtightness of an air chamber behind a rubber film that constitutes a sub-liquid chamber.

[0002]

2. Description of the Related Art FIG. 7 shows an example of a conventional liquid filled vibration damping device. In the figure, a container-shaped thick rubber wall 1 that opens downward has an opening closed by a partition plate 3, and the inside is the main liquid chamber A.
Has become. An upper plate 11 is placed on the top surface of the rubber wall 1, and a vibrating body such as an engine is connected and fixed to a bolt member 12 standing on the upper plate 11.

The partition plate 3 has a rubber plate 32 at the center and a groove on the outer peripheral surface to form a throttle channel 31. A thin rubber film 2 is disposed below the partition plate 3, and the outer peripheral edge of the thin rubber film 2 is in close contact with the outer peripheral lower surface of the partition plate 3 to form a sub liquid chamber B with the partition plate 3.

A container-like bottom plate 4 which is opened upward is provided so as to cover the rubber film 2 from below to behind the rubber film 2, and the opening peripheral edge of the cylindrical side plate 5 joined to the opening peripheral edge of the rubber wall 1. The lower end is caulked and fixed so as to sandwich the outer circumference of the partition plate 3 and the rubber film 2.

A bolt member 6 is provided at the center of the bottom plate 4 so as to penetrate therethrough and project downwardly. The bolt member 6 is inserted into a mounting hole of a vehicle frame F which is a base body as shown in the drawing, and a nut 7 is used. Fix it.

[0006]

In the above conventional structure, the air chamber C is required to be airtight behind the rubber film 2 so as to exert a proper air spring.
It is necessary to use a bolt member 6 having a high axial force and a high tensile strength in order to obtain a sufficient fastening torque, so that welding cannot be performed. Therefore, the bolt member is press-fitted and fixed, but since the airtightness cannot be secured by the press-fitting, conventionally, as shown in FIG. 7, a shallow dish-shaped spacer 8 is provided between the rubber film 2 and the bottom plate 4, and the opening edge thereof is By closely contacting the lower surface of the outer periphery of the rubber film 2, an air chamber C that maintains airtightness is formed. However, this requires the production and assembly of a separate spacer 8, which requires labor and cost.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid-filled anti-vibration device which can inexpensively and easily secure the airtightness of the air chamber behind the sub-liquid chamber.

[0008]

To explain the structure of the present invention, a vibrating body is placed on the top surface of a container-shaped thick rubber wall 1 that opens downward, and the opening of the rubber wall 1 is squeezed. A partition plate 3 provided with a passage 31 closes the interior to form a main liquid chamber A, and an outer peripheral edge of the partition plate 3 is brought into close contact with the outer peripheral edge of the partition plate 3 to provide a thin rubber film 2. Throttle channel 3
A sub-liquid chamber B communicating with the main liquid chamber A via 1 is formed, and the above-mentioned rubber film 2 is covered from below to form an air chamber C behind the rubber film 2. The peripheral edge of the opening is joined to the peripheral edge of the opening of the rubber wall 1, the bottom plate 4 is fixed to the base body F by a bolt member 6 penetrating the bottom surface and protruding downward, and the bottom plate 4 of the bolt member 6 is penetrated. The entire circumference of at least one axial direction of the shaft outer peripheral surface,
And / or the airtight seal portion 63 is formed on at least one circumferential portion of the lower surface of the head portion of the bolt member 6 in contact with the bottom plate 4 surface.
Is formed.

[0009]

In the above structure, since the airtight seal portion 63 is formed on the outer peripheral surface of the shaft portion 61 and / or the lower surface of the head portion 62 of the bolt member 6 penetrating the bottom plate 4, the bolt member 6 fixed by press fitting or the like is used. The gap between the outer periphery and the bottom plate 4 is sealed, and airtightness of the air chamber C behind the rubber film 2 is ensured.

Since the conventional spacer is not required, the number of man-hours for producing and assembling is reduced, and the cost is reduced.

[0011]

[Embodiment 1] FIG. 2 shows the overall structure of a vibration isolator, the basic structure of which is the same as that of the conventional structure already described, and the differences will be mainly described below.

A main liquid chamber A having a rubber wall 1 for supporting the engine as a chamber wall and a sub liquid chamber B having a rubber film 2 as a chamber wall are partitioned by a partition plate 3 provided with a throttle channel 31. The back of the rubber film 2 is closed by a container-shaped bottom plate 4 to form an air chamber C. A bolt member 6 is provided at the center of the bottom plate 4 so as to penetrate downward, and an airtight seal portion 63 is formed on a head portion 62 of the bolt member 6 which is in contact with the bottom plate 4.

The details will be described with reference to FIG. 1. The bolt member 6 has a head portion 62 which contacts the inner surface (top surface in the drawing) of the bottom plate 4.
The entire outer peripheral edge of the lower surface of the above protrudes downward in a wedge cross section to form the airtight seal portion 63. Then, in the state where the shaft portion 61 having the thread groove formed on the outer periphery is press-fitted into the hole 41 at the center of the bottom plate 4 as shown in the figure, the airtight seal portion 63, which is a part of the bolt member having high rigidity, is attached to the bottom plate 4. Cut into the inside.

As a result, even if there is a gap between the outer circumference of the shaft portion 61 of the bolt member 6 and the inner circumference of the punched hole 41 of the bottom plate 4, it is closed by the airtight seal portion 63 that digs into the inner surface of the bottom plate 4, and the air chamber is closed. The airtightness of C is secured.

According to this structure, since the airtight seal portion 63 of the bolt member 6 to be press-fitted ensures the airtightness of the air chamber C, it is not necessary to install a spacer as in the conventional case.
The structure is simple and inexpensive.

[0016]

[Embodiment 2] FIG. 3 shows another example of the airtight seal portion formed on the bolt member 6, in which a recess 42 having a rectangular cross section is formed around the lower end opening of the bottom hole 4 of the bottom plate 4. The airtightness of the air chamber C is ensured by closely fitting the rectangular convex airtight seal portion 64 formed on the outer periphery of the bolt shaft portion 61 in the place 42.

The seal portion 64, as shown in FIG.
The upper end portion of the bolt shaft portion 61 penetrating the bottom plate 4 is stepped and has a large diameter, and this portion is formed in the recess 42 by caulking deformation.

[0018]

[Embodiment 3] FIG. 5 shows still another example of the airtight seal portion. A hermetic seal portion is formed by joining a seal rubber layer having a constant thickness to the entire upper surface of the shaft portion 61 of the bolt member 6 and the entire lower surface of the head portion 62. 6
It is set as 5. Then, with the bolt member 6 press-fitted into the vent hole 41 of the bottom plate 4, the airtight seal portion 65 is in close contact with the inner periphery of the vent hole 41 and the bottom plate surface to ensure the airtightness of the air chamber C.

[0019]

[Embodiment 4] As shown in FIG. 6, a sealing rubber layer 66 is provided so as to form a semicircular cross section over the entire circumference at one radial position on the lower surface of the bolt head 62 to form an airtight sealing portion. Even if this structure is brought into close contact with the inner surface of the bottom plate 4, the same effect as that of each of the above embodiments can be obtained.

[0020]

As described above, according to the liquid filled vibration damping device of the present invention, since the airtightness of the air chamber can be secured by the airtight seal portion formed on the bolt member, a separate spacer is provided. It is simple and inexpensive without the need for

[Brief description of drawings]

FIG. 1 is a sectional view of an upper end portion of a bolt member according to a first embodiment of the present invention.

FIG. 2 is an overall cross-sectional view of the device according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of the upper end portion of the bolt member when the mounting is completed according to the second embodiment of the present invention.

FIG. 4 is a cross-sectional view of the upper end portion of the bolt member when the mounting is not completed in the second embodiment of the present invention.

FIG. 5 is a sectional view of an upper end portion of a bolt member according to a third embodiment of the present invention.

FIG. 6 is a sectional view of an upper end portion of a bolt member according to a fourth embodiment of the present invention.

FIG. 7 is an overall cross-sectional view of a conventional device.

[Explanation of symbols]

 1 rubber wall 2 rubber film 3 partition plate 31 throttle channel 4 bottom plate 6 bolt member 63, 64, 65, 66 airtight seal part A main liquid chamber B sub liquid chamber C air chamber F vehicle frame (base body)

Claims (1)

[Claims] 1. A vibrating body is placed on the top surface of a container-shaped thick rubber wall that opens downward, and the opening of the rubber wall is closed by a partition plate provided with a throttle channel to make the main liquid inside. A thin rubber film is formed by closely contacting the outer peripheral edge of the outer peripheral surface of the partition plate with the chamber to form a sub liquid chamber communicating with the main liquid chamber via the throttle channel, and An upwardly opened container-like bottom plate is provided which covers the rubber film from below and forms an air chamber behind the rubber film, and the opening peripheral edge is joined to the opening peripheral edge of the rubber wall and penetrates the bottom surface and projects downward. The bottom plate is fixed to the base body by a bolt member, and at least the entire circumference of at least one axial direction of the outer peripheral surface of the shaft portion that penetrates the bottom plate of the bolt member and / or at least the diameter of the lower surface of the head portion of the bolt member that contacts the bottom plate surface. An airtight seal is formed around the entire circumference in one direction. Liquid-filled anti-vibration device characterized by