| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic shock absorber of car height automatic adjusting type, whereby the discharge amount of a pumping means is increased properly and leakage of the oil from a cylinder to oil tank is decreased. SOLUTION: In a cylinder 2, a piston 5 with which a piston rod 6 is coupled is fitted. A pump rod 17 on the cylinder side is inserted into a pump tube 13 on the side with piston rod 6 so that a pump chamber 23 is formed. The pump chamber 23 is expanded and contracted by elongation and shrinkage of the piston rod 6 so that oil is supplied from an oil tank 4 to the cylinder 2 to cause elongation of the piston rod 6, and the oil in the cylinder 2 is returned to the oil tank 4 via an orifice 28 to shorten the piston rod 6, and thereby the car height is adjusted to a constant value. When the piston rod 6 shortens exceeding the specified position, a major diameteric portion 22 of the pump rod 17 is fitted in the fitting part 18 of the pump tube 13 to cause the discharge amount to increase. Because the orifice 28 is located in a minor diameteric portion 17b of the pump rod 17, leakage of the oil is decreased.
|
