Abstract: A fluid pressure shock absorber includes a piston connected to an end of a piston rod and slidably moving inside a cylinder tube and dividing the cylinder tube into a piston-side chamber and a rod-side chamber, a rod internal space formed inside the piston rod, a first communication passage communicating the rod-side chamber with the rod internal space, a second communication passage formed in the piston and communicating the piston-side chamber with the rod internal space, and a restrictor provided in the second communication passage to apply a resistance to a flow of a working fluid passing through the second communication passage.

Abstract: A cylinder device includes an annular cushion ring that prevents collision between the cylinder head and the rod head at stroke end during contraction. The cushion ring is formed by linking a plurality of ring segments in a circumferential direction so as to have an annular shape. The ring segments have a main body portion and linkage portions formed on both ends of the main body portion in the circumferential direction, the linkage portions linking the neighboring ring segments. The linkage portions of the neighboring ring segments are mutually overlapped in an axial direction of the cushion ring and linked such that relative movement in a radial direction of the cushion ring is restricted.

Abstract: A cylinder device includes a piston rod that is inserted into a cylinder so as to be movable back and forth. The piston rod has a rod portion that extends outside the cylinder, and a piston connected to an end portion of the rod portion, the piston moving in the cylinder in a slidable manner. The rod portion has a rod inner space formed in the rod portion, the rod inner space communicating with the piston-side chamber of the cylinder, a first communicating passage that connects the rod inner space and the rod-side chamber of the cylinder, and an orifice plug provided in the first communicating passage in a changeable manner. The piston is connected to the rod portion so as to cover a part of the orifice plug.

Abstract: A piston of a fluid pressure cylinder comprises a sealing ring interposed in a sealing ring accommodation groove, a piston ring that is interposed in a piston ring accommodation groove of the piston and comprises a fractured portion, and a backup ring that is attached to an outer peripheral surface of the piston and contacts the sealing ring and the piston ring. A groove for holding the backup ring is not required, and therefore a diameter of the piston can be reduced relative to the sealing ring. As a result, attachment of the sealing ring to the piston is simplified.

Abstract: A cushion mechanism for decelerating a piston rod includes a holder fastened to an end surface of a cylinder portion fitted with an inner peripheral surface of a cylinder tube, a plurality of fastening bolts for fastening the holder to the cylinder portion, an annular entry portion provided on the piston rod and advancing into the holder and the cylinder portion in the vicinity of the stroke end, a cushion passage formed by penetrating at least one of the plurality of fastening bolts and allowing a working chamber and a discharge port to communicate with each other and leading a working fluid in the working chamber to a discharge port, and an orifice portion provided on the cushion passage and applying resistance to a flow of the working fluid.

Abstract: A cushion mechanism for decelerating a piston rod includes a holder fastened to an end surface of a cylinder portion fitted with an inner peripheral surface of a cylinder tube, an annular entry portion provided on the piston rod and advancing into the holder and the cylinder portion in the vicinity of the stroke end, a cushion passage leading a working fluid of the working chamber to a supply/discharge port, and an orifice plug fastened to the cushion passage, and the cushion passage includes an internal passage extending in a radial direction of the holder and to which the orifice plug is fastened, and the orifice plug is replaceable through a replacement port formed by penetrating the cylinder tube and communicating with the internal passage.

Abstract: A cylinder device includes a piston rod that is inserted into a cylinder so as to be movable back and forth. The piston rod has a rod portion that extends outside the cylinder, and a piston connected to an end portion of the rod portion, the piston moving in the cylinder in a slidable manner. The rod portion has a rod inner space formed in the rod portion, the rod inner space communicating with the piston-side chamber of the cylinder, a first communicating passage that connects the rod inner space and the rod-side chamber of the cylinder, and an orifice plug provided in the first communicating passage in a changeable manner. The piston is connected to the rod portion so as to cover a part of the orifice plug.

Abstract: A cylinder device includes an annular cushion ring that prevents collision between the cylinder head and the rod head at stroke end during contraction. The cushion ring is formed by linking a plurality of ring segments in a circumferential direction so as to have an annular shape. The ring segments have a main body portion and linkage portions formed on both ends of the main body portion in the circumferential direction, the linkage portions linking the neighboring ring segments. The linkage portions of the neighboring ring segments are mutually overlapped in an axial direction of the cushion ring and linked such that relative movement in a radial direction of the cushion ring is restricted.

Abstract: A cushion mechanism for decelerating a piston rod includes a holder fastened to an end surface of a cylinder portion fitted with an inner peripheral surface of a cylinder tube, an annular entry portion provided on the piston rod and advancing into the holder and the cylinder portion in the vicinity of the stroke end, a cushion passage leading a working fluid of the working chamber to a supply/discharge port, and an orifice plug fastened to the cushion passage, and the cushion passage includes an internal passage extending in a radial direction of the holder and to which the orifice plug is fastened, and the orifice plug is replaceable through a replacement port formed by penetrating the cylinder tube and communicating with the internal passage.

Abstract: A cushion mechanism for decelerating a piston rod includes a holder fastened to an end surface of a cylinder portion fitted with an inner peripheral surface of a cylinder tube, a plurality of fastening bolts for fastening the holder to the cylinder portion, an annular entry portion provided on the piston rod and advancing into the holder and the cylinder portion in the vicinity of the stroke end, a cushion passage formed by penetrating at least one of the plurality of fastening bolts and allowing a working chamber and a discharge port to communicate with each other and leading a working fluid in the working chamber to a discharge port, and an orifice portion provided on the cushion passage and applying resistance to a flow of the working fluid.

Abstract: When a fluid pressure cylinder (1) is in a maximum expansion state, a piston (40) contacts a cylinder head (30). The cylinder head (30) is fixed to a cylinder tube (10) by a plurality of head bolts (12). The cylinder head (30) includes a pipe attachment seat (36), and the head bolts (12) are disposed in a first region (A) that avoids the pipe attachment seat (36). A non-contact portion in which contact is avoided between the piston (40) and the cylinder head (30) is formed in a second region (B) other than the first region (A), and therefore, when the fluid pressure cylinder (1) is in the maximum expansion state, a tensile load acting on the head bolts (12) on either side of the first region (A) can be suppressed to become equal to a tensile load acting on the other head bolts (12).

Abstract: A hydraulic cylinder includes a piston unit inside a cylinder to be free to slide within the cylinder; and a piston rod having the piston unit fixed to one end thereof and another end thereof projecting from the cylinder. The piston unit is inserted into a small diameter portion of the piston rod with an end surface thereof fixedly contacting a shoulder end surface of the piston rod. A round portion is formed as an annular concave in a base end portion outer periphery of the small diameter portion of the piston rod. A tapered portion is formed on an inner periphery of the piston unit from the end surface in alignment with a portion formed by concaving the small diameter portion. A length of the tapered portion in a piston unit axial direction is equal or greater than a length of the concave portion in a piston rod axial direction.

Abstract: A piston of a fluid pressure cylinder comprises a sealing ring interposed in a sealing ring accommodation groove, a piston ring that is interposed in a piston ring accommodation groove of the piston and comprises a fractured portion, and a backup ring that is attached to an outer peripheral surface of the piston and contacts the sealing ring and the piston ring. A groove for holding the backup ring is not required, and therefore a diameter of the piston can be reduced relative to the sealing ring. As a result, attachment of the sealing ring to the piston is simplified.

Abstract: When a fluid pressure cylinder (1) is in a maximum expansion state, a piston (40) contacts a cylinder head (30). The cylinder head (30) is fixed to a cylinder tube (10) by a plurality of head bolts (12). The cylinder head (30) includes a pipe attachment seat (36), and the head bolts (12) are disposed in a first region (A) that avoids the pipe attachment seat (36). A non-contact portion in which contact is avoided between the piston (40) and the cylinder head (30) is formed in a second region (B) other than the first region (A), and therefore, when the fluid pressure cylinder (1) is in the maximum expansion state, a tensile load acting on the head bolts (12) on either side of the first region (A) can be suppressed to become equal to a tensile load acting on the other head bolts (12).

Abstract: A hydraulic cylinder includes a piston unit inside a cylinder to be free to slide within the cylinder; and a piston rod having the piston unit fixed to one end thereof and another end thereof projecting from the cylinder. The piston unit is inserted into a small diameter portion of the piston rod with an end surface thereof fixedly contacting a shoulder end surface of the piston rod. A round portion is formed as an annular concave in a base end portion outer periphery of the small diameter portion of the piston rod. A tapered portion is formed on an inner periphery of the piston unit from the end surface in alignment with a portion formed by concaving the small diameter portion. A length of the tapered portion in a piston unit axial direction is equal or greater than a length of the concave portion in a piston rod axial direction.