Tokai Rubber Industries, Ltd.

Nissan Motor Company Limited

Keizo Konishi

Takao Yamamoto

Teruo Yonehama

Toshihiko Kakimoto

A fluid-filled resilient bushing structure having a resilient member interposed between an inner sleeve and an outer sleeve disposed radially outwardly of the inner sleeve. The resilient member has portions in which are formed plural fluid chambers which are filled with an incompressible fluid and held in communication with each other through an orifice. The resilient bushing structure comprises a non-fixed independent radial stop member of a rigid material accommodated in at least one of the plural fluid chambers and movable in this at least one fluid chamber. The radial stop member is abuttable on surfaces defining the at least one fluid chamber, thereby preventing an excessive displacement of the inner and outer sleeves relative to each other in a radial direction thereof.

Fluid-filled resilient bushing

A vibration damper comprising an elastic block having a cavity open at its bottom end, a support integrally united with the elastic block, a partition of a rigid material disposed adjacent the bottom end of the elastic block so as to close the cavity to form an operating chamber on one side of the partition, a diaphragm disposed on the other side of the partition and cooperating with the same to define an equilibrium chamber, and an orifice for effecting communications between the operating and equilibrium chambers which are filled with incompressible fluid. At least a portion of the diaphragm is formed of a thin layer of flexible material so that the equilibrium chamber is variable in its volume. The rigid partition undergoes substantially no deformation upon input of a vibrational energy into the operating chamber. A ratio of a dynamic spring rate to a static spring rate of the damper is not greater than 2.1 for high-frequency vibrations of higher than 50 Hz.

Vibration-damping structure

Herein disclosed is a damper device which is so constructed that a main sealed chamber is formed between one mounting member and the other mounting member by an elastic rubber member providing connection in between, that an auxiliary sealed chamber is formed at the opposite side of the other mounting member to the main sealed chamber by an elastic cover, that the main sealed chamber and at least a portion of the auxiliary sealed chamber are charged with a liquid, that the main sealed chamber and the auxiliary sealed chamber are partitioned by such a partition as is made movable in the direction jointing the two chambers and as is arranged to have its movable range restricted, and that a slot passage is formed between said partition and a wall surrounding the latter. The aforementioned passage is sized to generate in the liquid in the vicinity thereof not when high-frequency vibrations are applied from the one mounting member in the direction joining the two mounting members but when low-frequency vibrations are applied. The damper device thus constructed has remarkably excellent spring and damping constants.

Damper device for engine mountings or the like

An engine mount device comprises first and second base plate members; an elastic block securely interposed between the first and second base plate members and formed with a cavity; a partition plate member connected to one of the first and second base plate members and formed with an orifice; a diaphragm member connected to the one of the first and second base plate members and defining an auxiliary chamber between it and the partition plate member, the auxiliary chamber being in communication with the fluid chamber through the partition plate member orifice, at least a part of the fluid and auxiliary chambers being filled with a fluid; and a rigid ring disposed around the intermediate section of the elastic block thereby restricting the expansion of the elastic block; the elastic block and the rigid ring serving as a dynamic damper for damping vibration having predetermined frequencies, thereby rendering unnecessary installing the dynamic damper independent from the engine mount device.

Fluid-filled engine mount device

At least one confined chamber is formed by one and the other mounting fixtures and by a wall of rubber elastomer hermetically connecting the two fixtures, and a pump chamber made operative to effect a pumping action in response to the vibrations of the one mounting fixture is formed separately of the aforementioned confined chamber so that the atmosphere is pumped into the confined chamber from that pump chamber. In the damper support thus constructed, since the air is pumped into the inside when in the vibrations of low frequency, the damping factor can be made large. Even in the vibrations of high frequency, the dynamic spring constant can be made small.

Growing community of inventors

Inuyama, Japan

Keizo Konishi