Hydraulic shock absorber

A hydraulic shock absorber comprising:

• a cylinder housing;
• a piston chamber formed in the cylinder housing and filled with oil;
• a damping piston accommodated in the piston chamber so as to be able to move in the direction of the axis of the piston chamber;
• and
• a rod having a base end connected to the piston, the tip of the rod being led to the outside of the cylinder housing in a sealed state, wherein
• in a start part in which a moving object collides against the tip of the rod with the result that the piston starts to move, the inner surface of the piston chamber is formed so as to have a concave curve with a diameter larger than that of a virtual tapered surface formed within the diameter difference between the start end of a stroke range of the piston and the terminal narrower than the start end,
• in a main decelerating part after the start part, the variation of diameter reduction of the inner surface is gradually increased with the result that a diameter becomes smaller than that of the virtual tapered surface, and the concave curve is formed such that the change in the variation of diameter reduction reaches the maximum variation point and turns from positive to negative, and
• in an end part after the maximum variation point in the main decelerating part, the variation of diameter reduction is gradually decreased with the result that a convex curve is formed for the stop of the piston by damping.