Abstract: A piston coupled to a piston rod is inserted in a cylinder, and an outer cylinder is disposed around the cylinder so as to define a reservoir therebetween. A separator tube is disposed around the cylinder so as to define an annular passage therebetween. The piston rod can be locked and unlocked by closing and opening an electromagnetic open/close valve so as to block and allow a flow of hydraulic fluid through a flow passage between the annular passage and the reservoir. The separator tube has a greater thickness. O-rings are disposed so as to provide seals between the separator tube and the cylinder. The separator tube extends to positions such that the ends of the separator tube overlap a base valve and a rod guide, thereby holding the respective ends of the cylinder. Due to this configuration, it is possible to prevent deformation of the cylinder and the separator tube due to an increase in the hydraulic pressure.

Abstract: A piston coupled to a piston rod is inserted in a cylinder, and an outer cylinder is disposed around the cylinder so as to define a reservoir therebetween. A separator tube is disposed around the cylinder so as to define an annular passage therebetween. The piston rod is locked and unlocked so that a movement of the piston is prevented and allowed, by closing and opening an electromagnetic open/close valve so as to block and allow a flow of hydraulic fluid through a flow passage between the annular passage and the reservoir. The separator tube has a greater thickness. O-rings are disposed so as to provide seals between the separator tube and the cylinder. The separator tube extends to positions such that the ends of the separator tube overlap a base valve and a rod guide, thereby holding the respective ends of the cylinder. Due to this configuration, it is possible to prevent deformation of the cylinder and the separator tube due to an increase in the hydraulic pressure, and improve the pressure resistance.

Abstract: In a cylinder apparatus such as a hydraulic shock absorber, a piston to which a piston rod is connected slidably is inserted into a cylinder which contains liquid oil. A rebound spring is wound around the piston rod with one end of the piston rod fixed to the piston rod using a spring holder. The rebound spring is slidably guided along the piston rod by means of another spring holder. A rebound stopper is fixed to the piston rod at a position between the spring holders. The rebound spring exerts a spring force opposite to the extension of the piston rod, thereby to moderate shock at the end of the stroke of the piston. Because the spring holder comes into contact with the rebound stopper, contact of adjacent linear portions of the rebound spring with each other due to excessive compression of the rebound spring can be prevented, and also occurrence of strange noise and damage of the rebound spring can be prevented.

Abstract: In a cylinder apparatus such as a hydraulic shock absorber, a piston to which a piston rod is connected slidably is inserted into a cylinder which contains liquid oil. A rebound spring is wound around the piston rod with one end of the piston rod fixed to the piston rod using a spring holder. The rebound spring is slidably guided along the piston rod by means of another spring holder. A rebound stopper is fixed to the piston rod at a position between the spring holders. The rebound spring exerts a spring force opposite to the extension of the piston rod, thereby to moderate shock at the end of the stroke of the piston. Because the spring holder comes into contact with the rebound stopper, contact of adjacent linear portions of the rebound spring with each other due to excessive compression of the rebound spring can be prevented, and also occurrence of strange noise and damage of the rebound spring can be prevented.