Abstract: A buffer includes a first seal portion, a second seal portion, a washer, and a bent portion. An annular body is provided between the washer and a rod guide, the first seal portion is provided on the inner peripheral side of the washer, or the inner peripheral side of the annular body, and the rod guide and an outer cylinder are radially spaced apart from each other at least on one end side of the outer cylinder. The outer peripheral side of the annular body has a bent portion bent and extending to the portion where the rod guide and the outer cylinder are radially spaced apart from each other, and the second seal portion is provided on the outer peripheral side of the bent portion.

Abstract: The first piston body includes a first passage which has a first opening that opens to the first chamber on the coupling surface with the second piston body and extends in the axial direction, and a second passage which has a second opening on the coupling surface, extends in the axial direction and has a third opening that opens to the second chamber, the second piston body is coupled to the first piston body to prevent direct communication with the first chamber of the second opening, the second opening has an inner opening portion that opens further inward in the radial direction than the first opening, and the inner opening portion communicates with a third passage formed in the second piston body.

Abstract: A buffer includes a first seal portion, a second seal portion, a washer, and a bent portion. An annular body is provided between the washer and a rod guide, the first seal portion is provided on the inner peripheral side of the washer, or the inner peripheral side of the annular body, and the rod guide and an outer cylinder are radially spaced apart from each other at least on one end side of the outer cylinder. The outer peripheral side of the annular body has a bent portion bent and extending to the portion where the rod guide and the outer cylinder are radially spaced apart from each other, and the second seal portion is provided on the outer peripheral side of the bent portion.

Abstract: A cylinder device includes; a cylinder; a rod protruding from the cylinder; an annular member formed at one end side of the cylinder; an annular closing section formed further outward in a cylinder inward/outward direction than the annular member to close the one end side of the cylinder; and an annular seal ring provided inward in the cylinder inward/outward direction from an outer circumferential side of the closing section. The seal ring includes: a front end side outer circumferential seal section; a base end side outer circumferential seal section; a front end side inner circumferential abutting section; and a base end side inner circumferential abutting section. At least one set of seal sections or abutting sections is constituted by convex sections protruding in a radial direction.

Abstract: A cylinder apparatus is configured to compatibly achieve an increase in mechanical strength and a reduction in weight of a metal ring of an oil seal member used in the cylinder apparatus. A hydraulic shock absorber (1) as a cylinder apparatus has a rod guide (9) provided at one end (2A) thereof. An annular oil seal member (10) is provided closer to the one end (2A) than the rod guide (9) so as to face the rod guide (9). The oil seal member (10) is secured by staked portions (2C) of the outer tube (2) between the staked portions (2C) and the rod guide (9). The oil seal member (10) includes a metal ring (11) and a seal member (13). The metal ring (11) is provided with a plurality of radially extending ribs (12) by locally deforming the metal ring (11).

Abstract: A cylinder apparatus is configured to compatibly achieve an increase in mechanical strength and a reduction in weight of a metal ring of an oil seal member used in the cylinder apparatus. A hydraulic shock absorber (1) as a cylinder apparatus has a rod guide (9) provided at one end (2A) thereof. An annular oil seal member (10) is provided closer to the one end (2A) than the rod guide (9) so as to face the rod guide (9). The oil seal member (10) is secured by staked portions (2C) of the outer tube (2) between the staked portions (2C) and the rod guide (9). The oil seal member (10) includes a metal ring (11) and a seal member (13). The metal ring (11) is provided with a plurality of radially extending ribs (12) by locally deforming the metal ring (11).

Abstract: The first piston body includes a first passage which has a first opening that opens to the first chamber on the coupling surface with the second piston body and extends in the axial direction, and a second passage which has a second opening on the coupling surface, extends in the axial direction and has a third opening that opens to the second chamber, the second piston body is coupled to the first piston body to prevent direct communication with the first chamber of the second opening, the second opening has an inner opening portion that opens further inward in the radial direction than the first opening, and the inner opening portion communicates with a third passage formed in the second piston body.

Abstract: A cylinder device includes; a cylinder; a rod protruding from the cylinder; an annular member formed at one end side of the cylinder; an annular closing section formed further outward in a cylinder inward/outward direction than the annular member to close the one end side of the cylinder; and an annular seal ring provided inward in the cylinder inward/outward direction from an outer circumferential side of the closing section. The seal ring includes: a front end side outer circumferential seal section; a base end side outer circumferential seal section; a front end side inner circumferential abutting section; and a base end side inner circumferential abutting section. At least one set of seal sections or abutting sections is constituted by convex sections protruding in a radial direction.

Abstract: A cylinder apparatus includes a flow path formed at a valve member through which a fluid flows when a rod is moved, a valve configured to open and close the flow path, and a restriction member disposed at a side in a direction in which the flow path of the valve is opened. The restriction member is an annular plate-shaped member in which an attachment hole is formed. The restriction member has a plurality of spring sections extending in the radial direction and configured to bias the valve toward the valve member and a stroke restriction section extending from between the neighboring spring sections in the radial direction and configured to restrict a stroke of the valve, which are installed at an outer circumferential side thereof. The stroke restriction section extends to form the same plane as the inner circumferential side of the restriction member.

Abstract: A shock absorber includes an annular outer seat protruding from a valve main body, an inner seat protruding inward of the outer seat of the valve main body, an intermediate seat disposed between the outer seat and the inner seat of the valve main body and protruding to surround an opening section of a passage, a first disk having a larger diameter than the outer seat and seated on the intermediate seat, a spring member configured to press the first disk toward the outer seat, a second disk stacked on the first disk, and a communication unit configured to bring the passage in communication with a space between the intermediate seat and the outer seat. The first disk starts to be pressed by the spring member to abut the outer seat while abutting the inner seat and the intermediate seat.

Abstract: Provided is a shock absorber that includes a disk support section protruding between an intermediate seat and an inner seat, having a tip height position in a protruding direction higher than that of the inner seat and lower than that of the intermediate seat, and continuously or discontinuously disposed in an annular shape. In a state in which a first disk is pressed against the inner seat and placed on an outer seat, the intermediate seat and the disk support section, in the first disk, a first bending section bent in a convex shape toward a valve main body side is formed between the inner seat and the disk support section, and a second bending section bent in a convex shape toward a side spaced apart from the valve main body is formed between the disk support section and the outer seat.

Abstract: Provided is a cylinder apparatus capable of obtaining optimum valve characteristics. The cylinder apparatus has an annular valve member provided with at least a part of flow paths and having a through-bore, a pin member inserted through the through-bore of the valve member, and an annular disk valve having the pin member inserted therethrough and movable at both inner and outer peripheries thereof selectively away from and into contact with one end surface of the valve member to open and close the flow paths, respectively. The valve member has a projecting portion around the through-bore on the one end surface. The projecting portion is locally provided with circumferentially spaced grooves. The disk valve has small-diameter portions extending toward the grooves from the inner periphery thereof. The small-diameter portions are slidable relative to the pin member.

Abstract: A cylinder apparatus includes a flow path which is provided in a valve member and through which a fluid circulates when a rod is moved; a disk valve which opens and closes the flow path; and a spring member which presses the disk valve in an axial direction. The spring member includes a first spring which comes into contact with the disk valve in a state in which the disk valve closes the flow path, and a second spring which comes into contact with the disk valve in a state in which the disk valve opens the flow path.

Abstract: A cylinder apparatus includes a flow path formed at a valve member through which a fluid flows when a rod is moved, a valve configured to open and close the flow path, and a restriction member disposed at a side in a direction in which the flow path of the valve is opened. The restriction member is an annular plate-shaped member in which an attachment hole is formed. The restriction member has a plurality of spring sections extending in the radial direction and configured to bias the valve toward the valve member and a stroke restriction section extending from between the neighboring spring sections in the radial direction and configured to restrict a stroke of the valve, which are installed at an outer circumferential side thereof. The stroke restriction section extends to form the same plane as the inner circumferential side of the restriction member.

Abstract: A fluid pressure shock absorber includes a piston which is constituted by two piston bodies. An annular valve seat is formed on a non-coupled surface of one of the piston bodies, so that extension-side communication passages are located radially inside the annular valve seat and compression-side communication passages are located radially outside the annular valve seat, and an annular valve seat is formed on a non-coupled surface of the other of the piston bodies, so that the compression-side communication passages are located radially inside the annular valve seat and the extension-side communication passages are located radially outside the annular valve seat. A sliding member is disposed around one of the pitons bodies. A rotation preventing unit for preventing relative rotation of the piston bodies is provided on coupled surfaces and of the piston bodies. A nut for fastening the piston bodies and disk valves is disposed at an end of a piston rod.

Abstract: Provided is a shock absorber that includes a disk support section protruding between an intermediate seat and an inner seat, having a tip height position in a protruding direction higher than that of the inner seat and lower than that of the intermediate seat, and continuously or discontinuously disposed in an annular shape. In a state in which a first disk is pressed against the inner seat and placed on an outer seat, the intermediate seat and the disk support section, in the first disk, a first bending section bent in a convex shape toward a valve main body side is formed between the inner seat and the disk support section, and a second bending section bent in a convex shape toward a side spaced apart from the valve main body is formed between the disk support section and the outer seat.

Abstract: A shock absorber includes an annular outer seat protruding from a valve main body, an inner seat protruding inward of the outer seat of the valve main body, an intermediate seat disposed between the outer seat and the inner seat of the valve main body and protruding to surround an opening section of a passage, a first disk having a larger diameter than the outer seat and seated on the intermediate seat, a spring member configured to press the first disk toward the outer seat, a second disk stacked on the first disk, and a communication unit configured to bring the passage in communication with a space between the intermediate seat and the outer seat. The first disk starts to be pressed by the spring member to abut the outer seat while abutting the inner seat and the intermediate seat.

Abstract: A cylinder apparatus includes a flow path which is provided in a valve member and through which a fluid circulates when a rod is moved; a disk valve which opens and closes the flow path; and a spring member which presses the disk valve in an axial direction. The spring member includes a first spring which comes into contact with the disk valve in a state in which the disk valve closes the flow path, and a second spring which comes into contact with the disk valve in a state in which the disk valve opens the flow path.

Abstract: A hydraulic shock absorber has a cylinder having a hydraulic fluid sealed therein and a piston connected with a piston rod and slidably provided in the cylinder. The piston is provided with a circular main seat portion to form a main valve chamber communicating with an extension passage. Arcuate sub-seat portions are provided in concentric relation to the main seat portion to form sub-valve chambers. A disk valve is seated on the main and sub-seat portions to form clearances between them that always communicate between the main and sub-valve chambers. The disk valve opens upon receiving the pressure in the main and sub-valve chambers. The clearances restrict the flow of hydraulic fluid flowing out through the sub-valve chambers at the beginning of opening of the disk valve to prevent a sharp change in damping force. The concentric arrangement of the main and sub-seat portions facilitates the setting of an initial deflection for the disk valve.

Abstract: A piston coupled with a piston rod is inserted in a cylinder sealingly containing operating fluid. A substantially circular outer seat, an inner seat, disk support portions, an intermediate seat are provided on the lower end surface of the piston. The disk support portions are disposed between the outer seat and the inner seat. The intermediate seat is disposed between the disk support portions and the outer seat. The protruding height of the disk support portion is shorter than the protruding height of the outer seat, and equal to or taller than the protruding height of the inner seat. The protruding height of the intermediate seat is shorter than the protruding height of the outer seat, and equal to or taller than the protruding height of the disk support portions.