Hydraulic shock absorber
AssigneesHitachi, Ltd., Nissan Motor Co., Ltd.
InventorsHajime Katou, Hikaru Nakajima, Takao Nakadate
Life of this patent
Estimating the term…
Abstract
A hydraulic shock absorber in which the flow of hydraulic fluid induced in each of extension and compression hydraulic fluid passages, by sliding movement of a piston, is controlled by a main disk valve to generate damping force. The valve opening pressure of the main disk valve is adjusted by the pressure in a back-pressure chamber. In a low piston speed region, the main disk valve closes a back-pressure chamber inlet passage. Therefore, the pressure in the backpressure chamber will not rise, and sufficiently small damping force is obtained. When the main disk valve opens, the backpressure chamber inlet passage opens simultaneously. Consequently, the pressure in the backpressure chamber rises, and the damping force increases.
Claims7
A hydraulic shock absorber comprising:
- a cylinder having a hydraulic fluid sealed therein;
- a piston slidably fitted in said cylinder;
- a piston rod connected at one end thereof to said piston, the other end of said piston rod extending to an outside of said cylinder;
- a main valve that generates damping force by controlling flow of hydraulic fluid induced by sliding movement of said piston;
- a back-pressure chamber that allows its internal pressure to act on said main valve in a direction for closing said main valve;
- and a back-pressure chamber inlet passage through which a part of the hydraulic fluid of said flow of hydraulic fluid is introduced into said back-pressure chamber to control opening of said main valve,
- wherein a valve mechanism is provided that increases a flow path area of said back-pressure chamber inlet passage when said main valve opens so that the damping force is not adjusted from outside of the hydraulic shock absorber.
A hydraulic shock absorber comprising:
- a cylinder having a hydraulic fluid sealed therein;
- a piston slidably fitted in said cylinder;
- a piston rod connected at one end thereof to said piston, the other end of said piston rod extending to an outside of said cylinder;
- a main valve that generates damping force by controlling flow of hydraulic fluid induced by sliding movement of said piston;
- a back-pressure chamber that allows its internal pressure to act on said main valve in a direction for closing said main valve;
- and
- a back-pressure chamber inlet passage through which a part of the hydraulic fluid of said flow of hydraulic fluid is introduced into said back-pressure chamber to control opening of said main valve,
- wherein a valve mechanism is provided that increases a flow path area of said back-pressure chamber inlet passage when said main valve opens,
- wherein said valve mechanism includes:
- an opening provided in said main valve;
- a notched disk installed upstream of said main valve and provided with at least one radially extending notch communicating with said opening;
- and
- a blocking disk provided upstream of said notched disk to block a portion of said notch that faces said opening, wherein when said main valve opens, it separates from said notched disk.
Dependencies are inferred from the claim text.