Abstract: A double-rod type shock absorber includes a rod, first and second pistons held by the rod, first and second piston chambers disposed on an outer side of the first and second pistons, a liquid storage chamber between the first piston and the second piston, a flow path gap formed between an outer peripheral surface of the first and second pistons and an inner peripheral surface of the liquid chamber, and first and second unidirectional flow paths which connect the first and second piston chambers with the liquid storage chamber, wherein, during reciprocating motion of the rod, the unidirectional flow path located on a front side in a movement direction of the rod is closed, and the unidirectional flow path located on a back side in the movement direction of the rod is opened.

Abstract: A double-rod type shock absorber includes a rod, first and second pistons held by the rod, first and second piston chambers disposed on an outer side of the first and second pistons, a liquid storage chamber between the first piston and the second piston, a flow path gap formed between an outer peripheral surface of the first and second pistons and an inner peripheral surface of the liquid chamber, and first and second unidirectional flow paths which connect the first and second piston chambers with the liquid storage chamber, wherein, during reciprocating motion of the rod, the unidirectional flow path located on a front side in a movement direction of the rod is closed, and the unidirectional flow path located on a back side in the movement direction of the rod is opened.

Abstract: A hydraulic shock absorber that can reduce outflow amount of oil by maximally removing an oil film attached to an outer periphery of a rod and that can achieve securement of high slidability between the rod and a rod packing and prevention of wear of the rod packing. A rod packing interposed between an outer periphery of a rod and an inner periphery of a rod-side end wall includes a first lip for scrapping off an oil film attached to the outer periphery of the rod, and a ring-shaped grease holding member for supplying holding grease to the outer periphery of the rod. The grease holding member is in contact with the outer periphery of the rod at a position closer to a rod distal end than the first lip.

Abstract: Provided is a shock absorber enabling stable stop by damping at a terminal of a stroke and covering demanded impact-absorbing models. The shock absorber has a piston chamber, a start part for piston movement, a decelerating part, and an end part for stopping the piston. The start part forms a curve to provide a diameter larger than a virtual tapered surface formed within a stroke range of the piston and to be outward to a central axis of the piston chamber. In the decelerating part, a variation of diameter reduction is increased with the result that the diameter becomes smaller than the tapered surface, and a curve is formed so the change in variation of diameter reduction reaches the maximum variation point and turns negative. In the end part, the variation of diameter reduction is decreased with the result that a curve which enables piston stopping by damping is formed.

Abstract: A hydraulic shock absorber that can reduce outflow amount of oil by maximally removing an oil film attached to an outer periphery of a rod and that can achieve securement of high slidability between the rod and a rod packing and prevention of wear of the rod packing. A rod packing interposed between an outer periphery of a rod and an inner periphery of a rod-side end wall includes a first lip for scrapping off an oil film attached to the outer periphery of the rod, and a ring-shaped grease holding member for supplying holding grease to the outer periphery of the rod. The grease holding member is in contact with the outer periphery of the rod at a position closer to a rod distal end than the first lip.

Abstract: Provided is a shock absorber enabling stable stop by damping at a terminal of a stroke and covering demanded impact-absorbing models. The shock absorber has a piston chamber, a start part for piston movement, a decelerating part, and an end part for stopping the piston. The start part forms a curve to provide a diameter larger than a virtual tapered surface formed within a stroke range of the piston and to be outward to a central axis of the piston chamber. In the decelerating part, a variation of diameter reduction is increased with the result that the diameter becomes smaller than the tapered surface, and a curve is formed so the change in variation of diameter reduction reaches the maximum variation point and turns negative. In the end part, the variation of diameter reduction is decreased with the result that a curve which enables piston stopping by damping is formed.