Spring devices – Resilient shock or vibration absorber – Including energy absorbing means or feature
Reexamination Certificate
1998-06-03
2001-08-14
Graham, Matthew C. (Department: 3613)
Spring devices
Resilient shock or vibration absorber
Including energy absorbing means or feature
C267S220000
Reexamination Certificate
active
06273406
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid encapsulated bushing used, for example, in a section for supporting a suspension arm of an automobile on a vehicle body.
2. Description of the Related Art
A liquid encapsulated bushing is known, for example, as described in Japanese Patent Application Laid-open No. 1-275209. In such a liquid encapsulated bushing, the dynamic spring constant can be reduced compared to the prior art bushing in which the absorption of a vibration is performed only by the elasticity of a bushing rubber. Hence, the load noise can be effectively decreased.
In the known liquid encapsulated bushing described in Japanese Patent Application Laid-open No. 1-275209, an inner tube and an outer tube are connected to each other by a single bushing rubber. For this reason, it is difficult not only to finely regulate axial and radial spring characteristics of the bushing rubber, but also to establish any sectional shape of a liquid chamber defined in the bushing rubber.
In addition, the known liquid encapsulated bushing described in Japanese Patent Application Laid-open No. 1-275209 includes a liquid chamber in an area where a cylindrical bushing rubber, which interconnects the inner and outer tubes, is in contact with the inner tube. For this reason, it is necessary not only to define an injecting bore, which extends through the outer tube and the bushing rubber, for injecting a liquid into the liquid chamber, but also to occlude the injecting bore after injection of the liquid. Thus, it is difficult to produce the liquid encapsulated bushing, and the cost is increased.
SUMMARY OF THE INVENTION
The present invention has been accomplished with the above circumstance in view. It is a first object of the present invention to provide a liquid encapsulated bushing, wherein the spring characteristics of the bushing rubber and the sectional shape of the liquid chamber can be easily determined.
It is a second object of the present invention to provide a liquid encapsulated bushing, wherein the encapsulation of the liquid into the liquid chamber can be easily carried out.
To achieve the above first object, according to a first aspect and feature of the present invention, there is provided a liquid encapsulated bushing comprising an inner tube supporting a spherical portion which is formed on a support shaft for rotation by an inner peripheral surface thereof. A first elastomeric member is fixed to an outer peripheral surface of the inner tube on an axially first end side. An outer tube is disposed to cover the outside of the inner tube. A second elastomeric member is fixed to the inner peripheral surface of the outer tube on the axially second end side. A liquid chamber, containing a liquid encapsulated therein, is defined between the first and second elastomeric members by axially inserting the inner tube into the outer tube, coupling the first elastomeric member to the inner peripheral surface of the outer tube on the axially first end side and coupling the second elastomeric member to the outer peripheral surface of the inner tube on the axially second end side.
With the above arrangement, the liquid chamber, containing the liquid encapsulated therein, is defined between the first elastomeric member and the second elastomeric member by axially coupling the assembly, which is integrally formed by the inner tube and the first elastomeric member, to the assembly integrally formed by the outer tube the second elastomeric member. The first and second elastomeric members can be produced separately. Hence, it is easy not only to finely regulate the axial and radial spring characteristics of the first and second elastomeric members, but also to establish any sectional shape for the liquid chamber.
To achieve the first object of the present invention, according to a second aspect and feature of the present invention, there is provided a liquid encapsulated bushing comprising an inner tube supporting a spherical portion which is formed on a support shaft for rotation by an inner peripheral surface thereof. A first elastomeric member is fixed to an outer peripheral surface of the inner tube on an axially first end side. An outer tube, whose inner peripheral surface on its axially first end side, is fixed to the first elastomeric member. A second elastomeric member is axially inserted into the outer tube and is fixed to the outer peripheral surface of the inner tube on its axially second end side and is fixed to the inner peripheral surface of the outer tube on its axially second end side. A liquid chamber is defined between the first and second elastomeric members and contains a liquid encapsulated therein.
With the above arrangement, the liquid chamber, containing a liquid encapsulated therein, is defined between the first and second elastomeric members by axially coupling the assembly, which is integrally formed by the inner tube, the first elastomeric member and the outer tube, to the second elastomeric member. The first and second elastomeric members can be produced separately. Hence, it is easy not only to finely regulate the axial and radial spring characteristics of the first and second elastomeric members, but also to establish any sectional shape for the liquid chamber.
To achieve the above second object, according to a third aspect and feature of the present invention, there is provided a liquid encapsulated bushing comprising an inner tube supporting a spherical portion which is formed on a support shaft for rotation by an inner peripheral surface thereof. A substantially cylindrical elastomeric member is fixed to an outer peripheral surface of the inner tube and has a circumferentially extending annular groove on its outer peripheral surface. A ring is fixed to the outer peripheral surface of the elastomeric member, so that at least a portion of the annular groove is exposed. An outer tube is fixed to an outer peripheral surface of the ring by drawing the outer tube radially inwards. A liquid chamber is defined between the annular groove and the outer tube and contains a liquid encapsulated therein.
With the above arrangement, when the assembly integrally formed by the inner tube, the elastomeric member and the ring is immersed in the liquid and the outer tube is placed over this assembly and fixed thereto by drawing thereof, the liquid is automatically encapsulated between the annular groove in the elastomeric member and the outer tube (namely, in the liquid chamber). Therefore, the operation of encapsulating the liquid into the liquid chamber can be easily performed.
The above and other objects, features and advantages of the invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 4893799 (1990-01-01), De Fontenay
patent: 5690320 (1997-11-01), Kanda
patent: 5947455 (1999-09-01), Mikasa et al.
patent: 1-275209 (1989-11-01), None
Doi Isamu
Miyamoto Yasuo
Tokimoto Hiroshi
Yamazaki Masaru
Arent Fox Kintner Plotkin & Kahn
Graham Matthew C.
Honda Giken Kogyo Kabushiki Kaisha
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