Hydraulic damper

Abstract

A hydraulic damper that produces a small damping force for small-amplitude vibrations and a large damping force for large-amplitude vibrations in a hydraulic damper for washing machines. A piston (3) connected with a piston rod (4) is slidably embedded in a cylinder (2) in which oil and gas are mixed and sealed, and immersed in the oil. The extension side oil passage (10) and the shortening side hole (11) are arranged at the bottom of the piston body (7), and the shortening side oil passage (12) and the extension side hole (13) are arranged on the cover part (8). The body (14) is arranged axially movable inside the piston (3). When the piston rod is at a small amplitude, the moving distance of the valve body (14) is small, and the oil passages (10) and (12) on the extension side and the shortening side are opened, so a small damping force is generated. The moving distance of (14) becomes larger, and the valve body (14) closes the extension side and shortening side oil passages (10), (12), so a large attenuation force.

Description

technical field [0001] The present invention relates to a hydraulic damper which can be used as a damper for a washing machine or the like for supporting a water tank in which a drum of a drum type washing machine is accommodated. Background technique [0002] Generally speaking, in a drum type washing machine such as a fully automatic washing machine, it has a rotating shaft that is approximately horizontal to the ground, and a substantially cylindrical water tank that accommodates a drum with laundry and is rotatably supported and becomes the washing machine. Springs and dampers are installed between the boxes of the outer contour of the machine, and the water tank is suspended by these springs and dampers, so as to absorb and stop the vibration generated by the rotation of the drum. [0003] As general dampers used in drum-type washing machines, friction dampers and hydraulic dampers are known. A friction damper generates a damping force through sliding friction of a fri...

AI Technical Summary

Problems solved by technology

[0007] In this way, in the damper for washing machines, it is required to have: a sufficiently large damping force is generated to suppress the shaking of the drum during resonance, and the damping force characteristics such as reducing the damping force and absorbing the vibration of the drum in normal times are required. In the above-mentioned Patent Document 1 The announced damper for washing machines satisfies this requirement to a certain extent, but its damping force tends to be insufficient at resonance, and there is room for further improvement

Images