Abstract: A shock absorber has an inclined surface that is inclined to a moving direction of the free piston in at least one of a free piston contact surface of a free piston with which an elastic body is in contact and a housing contact surface of a housing with which the elastic body is in contact. A shortest distance between the free piston contact surface and the housing contact surface is changed by movement of the free piston.

Abstract: A shock absorber includes a first passage (111) or (112) and a second passage (32), (99) or (235) in communication with each other and configured to allow a working fluid to flow between two chambers (16) and (17) based on movement of a piston (15), and a passage area adjustment mechanism (101) or (236) configured to adjust a passage area of the second passage (99) or (235) depending on a position of a piston rod (18) is installed to have at least one of a maximum length-side property in which an extension-side damping force becomes soft and a compression-side damping force becomes hard in a range in which the piston rod (18) extends to an outside of a cylinder (11) farther than a maximum length-side predetermined position, and a minimum length-side property in which the extension-side damping force becomes hard and the compression-side damping force becomes soft in a range in which the piston rod (18) enters an inside of the cylinder (11) further than a minimum length side predetermined position.

Abstract: A shock absorber includes a first passage (111) or (112) and a second passage (32), (99) or (235) in communication with each other and configured to allow a working fluid to flow between two chambers (16) and (17) based on movement of a piston (15), and a passage area adjustment mechanism (101) or (236) configured to adjust a passage area of the second passage (99) or (235) depending on a position of a piston rod (18) is installed to have at least one of a maximum length-side property in which an extension-side damping force becomes soft and a compression-side damping force becomes hard in a range in which the piston rod (18) extends to an outside of a cylinder (11) farther than a maximum length-side predetermined position, and a minimum length-side property in which the extension-side damping force becomes hard and the compression-side damping force becomes soft in a range in which the piston rod (18) enters an inside of the cylinder (11) further than a minimum length side predetermined position.

Abstract: A shock absorber has an inclined surface that is inclined to a moving direction of the free piston in at least one of a free piston contact surface of a free piston with which an elastic body is in contact and a housing contact surface of a housing with which the elastic body is in contact. A shortest distance between the free piston contact surface and the housing contact surface is changed by movement of the free piston.

Abstract: A shock absorber has an inclined surface that is inclined to a moving direction of the free piston in at least one of a free piston contact surface of a free surface with which an elastic body is in contact and a housing contact surface of a housing with which the elastic body is in contact. A shortest distance between the free piston contact surface and the housing contact surface is changed by movement of the free piston.

Abstract: A shock absorber includes first passages configured to communicate two chambers to flow a working fluid therebetween by movement of a piston, and a second passage configured to communicate with one chamber of the two chambers. The first passages have damping valves configured to suppress a flow of the working fluid generated by movement of the piston to generate a damping force. The second passage has a variable orifice having an area adjusted by an elastic member when a piston rod moves in an extension direction, a pressure chamber installed in series with the variable orifice, and a free piston configured to vary a volume of the pressure chamber by movement of the piston.

Abstract: A shock absorber includes a first passage and a second passage to which a working fluid flows out from one chamber in a cylinder by movement of a piston, a damping valve installed on the first passage and configured to regulate a flow of the working fluid caused by sliding of the piston to generate a damping force, a back pressure chamber applying an internal pressure to the damping valve in a closing direction of the damping valve, a back pressure chamber inflow oil passage introducing the working fluid from one chamber into the back pressure chamber, a pressure chamber provided in-between on the second passage, and a free piston installed in the pressure chamber so as to freely slide in the pressure chamber.

Abstract: A shock absorber includes first passages configured to communicate two chambers to flow a working fluid therebetween by movement of a piston, and a second passage configured to communicate with one chamber of the two chambers. The first passages have damping valves configured to suppress a flow of the working fluid generated by movement of the piston to generate a damping force. The second passage has a variable orifice having an area adjusted by an elastic member when a piston rod moves in an extension direction, a pressure chamber installed in series with the variable orifice, and a free piston configured to vary a volume of the pressure chamber by movement of the piston.

Abstract: A shock absorber has an inclined surface that is inclined to a moving direction of the free piston in at least one of a free piston contact surface of a free piston with which an elastic body is in contact and a housing contact surface of a housing with which the elastic body is in contact. A shortest distance between the free piston contact surface and the housing contact surface is changed by movement of the free piston.

Abstract: A shock absorber includes a first passage and a second passage to which a working fluid flows out from one chamber in a cylinder by movement of a piston, a damping valve installed on the first passage and configured to regulate a flow of the working fluid caused by sliding of the piston to generate a damping force, a back pressure chamber applying an internal pressure to the damping valve in a closing direction of the damping valve, a back pressure chamber inflow oil passage introducing the working fluid from one chamber into the back pressure chamber, a pressure chamber provided in-between on the second passage, and a free piston installed in the pressure chamber so as to freely slide in the pressure chamber.

Abstract: After insertion of a mandrel (23) into a blank tube (20) in the form of an electric welded tube, a parallel swaging operation is carried out by moving a cylindrical die (24) to cause the end of the blank tube (20) to contact tightly with a parallel forming portion (27) of the mandrel (23). After completion of parallel swaging operation, the die (24) is withdrawn out of the blank tube (20) and a push-die (33) is caused to move to the blank tube (20) from a radially outward position while leaving the mandrel (23) inside the blank tube (20) so that a weld bead on the blank tube (20) can be flattened by cooperation with the mandrel (23).

Abstract: A piston connected with a piston rod is slidably fitted in a cylinder having a hydraulic fluid sealed therein. An extension-side main disk valve generates a damping force in a high piston speed region against the flow of hydraulic fluid in an extension-side passage. A sub-passage bypasses the extension-side main disk valve, and an extension-side sub disk valve generates a damping force in an intermediate piston speed region. A compression-side main disk valve generates a damping force in the high piston speed region against the flow of hydraulic fluid in a compression-side passage. A sub-passage bypasses the compression-side main disk valve, and a compression-side sub disk valve generates a damping force in the intermediate piston speed region. Damping force characteristics in the intermediate and high piston speed regions can be set according to the valve-opening characteristics of these disk valves. Therefore, it is possible to increase the degree of freedom for setting damping force characteristics.

Abstract: After insertion of a mandrel 23 into a blank tube 20 in the form of an electric welded tube, a parallel swaging operation is carried out by moving a cylindrical die 24 to cause the end of the blank tube 20 contact tightly with a parallel forming portion 27 of the mandrel 23, and after completion of parallel swaging operation, the die 24 is withdrawn out of the blank tube 20 and a push-die 33 is caused to move to the blank tube 20 from a radially outward position while leaving the mandrel 23 inside the blank tube 20 so that a weld bead on the blank tube 20 can be flattened by cooperation with the mandrel 23.

Abstract: A groove processing method capable of smoothly processing a groove on a rod that has been subjected to a hardening treatment without a substantial degradation in strength is provided. A pair of straightening rollers is mounted at each side of rolling rollers mounted on respective rotating shafts of a rolling machine with spacers disposed between the straightening and rolling rollers. A rod is previously subjected to a hardening treatment, for example, high-frequency induction hardening and tempering, or carbulizing & quenching and tempering, so that the surface hardness is not less than 400 Hv. A groove is formed on the rod by rolling using the rolling rollers, thereby allowing a surface hardening layer to be left on the bottom of the groove. At the same time, the rod is held by the straightening rollers to prevent bending of the rod.