Spring devices – Resilient shock or vibration absorber – Including energy absorbing means or feature
Reexamination Certificate
2001-10-12
2002-08-27
Schwartz, Christopher P. (Department: 3683)
Spring devices
Resilient shock or vibration absorber
Including energy absorbing means or feature
C267S219000
Reexamination Certificate
active
06439555
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a vibration-isolating apparatus adapted to support a vibration generating member, such as an engine of an automobile in a vibration isolating manner with respect to a body.
As the space saving techniques for the interior of an engine room of an automobile produced in recent years have been developed, functional parts have been miniaturized and arranged in a very narrowly spaced condition. Therefore, the conditions for repairing the functional parts have become increasingly severe, and the creation of functional parts of high durability and reliability has been demanded.
JP-Y1-1993-003789 (JP-Y1-05003789 or Japanese Utility Model Publication Examined No. 3789/1993) discloses a vibration-isolating apparatus (hereinafter referred as Prior Art 1) of the following structure, for supporting an engine in a vibration-isolating manner in such an engine room with respect to a vehicle body. This vibration-isolating apparatus comprises a first fixture secured to a bracket of an engine; a second fixture secured to a body; a vibration-isolating base body formed of an elastic material such as rubber interposed between and connecting together these two fixtures; a stopper rubber projecting outward from the portion of the vibration-isolating base body which is on the side of the second fixture; and a metal stopper fixed to the first fixture so as to surround the stopper rubber. The metal stopper and stopper rubber prevent an excess deformation of the vibration-isolating basebody. The metal stopper is formed of a metal plate by bending the same so as to have a substantially sideway-fallen J-shaped cross section so that the metal stopper has contact surfaces respectively parallel to stopper surfaces of the stopper rubber, stoppering action is achieved in all of the following three directions—compression and drawing directions in which the first and second fixtures are moved relatively toward and away from each other; a radial direction perpendicular to these directions, for example, forward or backward direction of the vehicle; and a circumferential direction, for example, rightward or leftward direction of the vehicle. This metal stopper prevents damage on the elastic material constituting the vibration-isolating base body and stopper rubber.
On the other hand, JP-A-1997-079310 (JP-A-09079310, or Japanese Patent Publication Unexamined No. 79310/1997) discloses another vibration-isolating apparatus (hereinafter, referred as Prior Art 2) of the following structure. This apparatus includes a metal stopper which has the same shape as mentioned above and serves for restring displacements between upper and lower fixtures in all of following direction—compression and drawing directions in which the first and second fixtures are moved relatively toward and away from each other; a radial direction perpendicular to these directions, for example, forward or backward direction of the vehicle; and a circumferential direction, for example, rightward or leftward direction of the vehicle. The metal stopper is formed by bending a plate or sheet so as to have a substantially sideway-fallen J-shaped cross section and so as to be combined firmly with the first fixture. The metal stopper is bonded firmly to an upper part of a vibration-isolating base body formed of an elastic member such as rubber, in such a manner that the metal stopper is opposed to a stopper rubber.
In such vibration-isolating apparatuses, the durability and reliability thereof have increasingly been demanded. Especially, because an upward-facing contact surface of the metal stopper, which surface abuts on the stopper rubber when the metal stopper is displaced greatly in the drawing direction, has to come to the lower side of the stopper rubber by moving around the stopper rubber, it is desired that a slip-off of the metal stopper can be prevented even when a momentary large stress in drawing direction is applied.
However, the above-described vibration-isolating apparatus of Prior Art 2 is not satisfactory concerning its ability to prevent a slip-off of the metal stopper.
In view of the above, the present invention is aimed to provide a vibration-isolating apparatus and a metal stopper therefor which have a long-lasting durability and reliability.
As for Prior Art 1, in which a metal stopper is formed so as to surround a stopper rubber in three directions, the spatial dimensions for a stopper mechanism increases to cause a problem to occur in the mountability thereof.
The vibration-isolating apparatus supporting the engine is fixed in a rightwardly or leftwardly inclined state to a bracket in a vehicle. Therefore, whereas a large stress in rightward or leftward direction rarely cause an excessive stress to be exerted on other parts on the vehicle, a large stress in forward or backward direction causes the stopper rubber to collide with the metal stopper. By the collision, bending stress is exerted on fixing bolts for the second fixture on the lower side due to the reaction ascribed to the impact of the collision. This exerts an ill influence upon the sealability and fastening force between the lower side fixture and fixing bolts, and causes problems to occur in the reliability of the apparatus.
In the Prior Art 2, the metal stopper is merely formed by bending a plate or sheet so as to have a substantially sideway-fallen J-shaped cross section. Since this metal stopper has a structure not interfering with the stopper rubber at displacements in the circumferential direction or the forward or backward direction, the mountability of the apparatus is high as compared with that of the Prior Art 1, while the fixture does not have an ill influence upon the fixing bolts. However, since the metal stopper is bonded firmly with the elastic body at vulcanization of the elastic body, rubber burr is left on the metal stopper, so that the controlling of a stopper clearance, or distance between abutting surfaces, is difficult.
The metal stopper maybe formed separately from the elastic body and assembled thereto later so as to eliminate the problems due to the rubber burr. However, because the metal stopper is formed by merely bending a plate material so as to have a substantially sideway-fallen J-shaped cross section, a required rigidity of the metal stopper cannot be maintained against a large stress in the compression and drawing directions or in the lateral direction. When a flange is formed by bending the edges on circumferential-direction-wise end of the metal stopper in order to maintain the rigidity of the metal stopper, the flange necessarily hits the stopper rubber. Consequently, the Prior Art 2 has problems similar to those of the Prior Art 1.
In view of the above, second object of the present invention is solving at once the above-mentioned problems of the prior art, and for achieving altogether following—the improvement of the mountability of the apparatus; the prevention of circumferential-direction-wise interference of the metal stopper with the stopper rubber; and an increase in the rigidity of the metal stopper.
BRIEF SUMMARY OF THE INVENTION
First aspect of the present invention provides a vibration-isolating apparatus, having a structure basically identical with Prior Arts 1 and 2, capable to prevent a slip-off of the metal stopper in the drawing direction by improving the metal stopper, and thereby improve the durability and reliability of the apparatus.
According to the first aspect, the vibration-isolating apparatus includes a first fixture; a second fixture; a vibration-isolating base body interposed between these two fixtures and formed of an elastic material having rubber-like elasticity; a stopper rubber projecting outward so as to restrict a large displacement of the vibration-isolating base body; and a metal stopper surrounding this stopper rubber; and the metal stopper being formed by bending a metal plate or sheet. The metal stopper has contact surfaces respectively parallel to stopper surfaces of the stopper rubber, for restricting displacements in following direction—a compress
Hashimoto Tsutomu
Takashima Yukio
Bartz C. T.
Jordan and Hamburg LLP
Schwartz Christopher P.
Toyo Tire & Rubber Co., Ltd.
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