Abstract:
A shock absorber includes; a free piston that partitions the compression chamber into an expansion-side compression chamber and a contraction-side compression chamber; an expansion-side flow passage that connects the expansion-side chamber with the expansion-side compression chamber; a contraction-side flow passage that connects the contraction-side chamber with the contraction-side compression chamber; an expansion-side bypass valve provided in the expansion-side flow passage to admit only a flow directed from the expansion-side chamber to the expansion-side compression chamber and generate resistance; a contraction-side bypass valve provided in parallel with the expansion-side bypass valve to admit only a flow directed from the expansion-side compression chamber to the expansion-side chamber and generate resistance; an expansion-side elastic stopper configured to stop the free piston at an expansion-side stroke end; and a contraction-side elastic stopper configured to stop the free piston at a contraction-side stroke end.
Abstract:
A working machine control system includes a split flow type fluid pressure pump configured to discharge a working fluid from a first discharge port and a second discharge port, and a lower pressure selection circuit configured to select and communicate with a working fluid of lower pressure among a working fluid on the downstream of a first operation valve of a first neutral passage in a first circuit system to which a working fluid discharged from the first discharge port is supplied, and a working fluid on the downstream of a second operation valve of a second neutral passage in a second circuit system to which a working fluid discharged from the second discharge port is supplied. The fluid pressure pump is adjusted in such a manner that the lower the pressure of the working fluid selected by the lower pressure selection circuit is, the more a discharge flow rate is increased.
Abstract:
A shock absorber includes a cylinder, a piston that partitions the cylinder into an expansion-side chamber and a contraction-side chamber, a piston rod connected to the piston, a damping passage that allows the expansion-side chamber to communicate with the contraction-side chamber, a pressure chamber that communicates with the expansion-side chamber and the contraction-side chamber, a free piston that partitions the pressure chamber into an expansion-side pressure chamber and a contraction-side pressure chamber, a spring element configured to position the free piston in a neutral position with respect to the pressure chamber and exert a biasing force for suppressing a displacement of the free piston from the neutral position, and a damping force control unit provided in the damping passage, the damping force control unit being configured to change resistance to a flow of the hydraulic fluid passing therethrough.
Abstract:
A damper control device includes a vibration level detection unit configured to detect a vibration level of the unsprung member, and a control unit configured to control the damping force characteristics of the damper by obtaining a control instruction, the control instruction determining the damping force characteristics on the basis of the vibration level detected by the vibration level detection unit.
Abstract:
A valve includes a valve disc and annular-plate shaped leaf valves. The leaf valves are laminated on each of the one chamber side and the other chamber side of the valve disc. The valve disc includes annular bosses and seats. The boss is formed at each of the one chamber side and the other chamber side to support the leaf valves. The seats are formed on outer peripheral sides of the respective bosses on the one chamber side and the other chamber side. The leaf valves are left from/seated on the seats. At least one of the seats on the one chamber side and the other chamber side are disposed to project with respect to the bosses. An outer peripheral end on the seat on the other chamber side is disposed on an outer peripheral side with respect to an outer peripheral end of the leaf valve. The leaf valve is seated on the seat on the other chamber side. The outer peripheral end of the seat on the other chamber side is disposed at a position identical to an outer peripheral end of the seat on the one chamber side in a radial direction of the valve disc. Alternatively, the outer peripheral end of the seat on the other chamber side is disposed on an outer peripheral side with respect to the outer peripheral end of the seat on the one chamber side.
Abstract:
A shock absorber includes a piston joined to a piston rod that proceeds into and recedes from a cylinder, an extension-side chamber and a compression-side chamber that are separated from each other by the piston and have a working fluid reserved therein, first and second extension-side discharge passages in which the working fluid discharged from the extension-side chamber flows, an extension-side supply passage in which the working fluid to be supplied to the compression-side chamber flows, first and second compression-side discharge passages in which the working fluid discharged from the compression-side chamber flows, and a compression-side supply passage in which the working fluid to be supplied to the extension-side chamber flows. An extension-side damping valve and a compression-side damping valve are respectively provided in the first extension-side discharge passage and the first compression-side discharge passage. An extension-side electromagnetic pressure control valve and a compression-side electromagnetic pressure control valve, which are respectively provided in the second extension-side discharge passage and the second compression-side discharge passage, are set such that the openings thereof are maximized before the piston speed reaches a high-speed range.
Abstract:
A shock absorber includes: a metal cylindrical outer tube; a rod inserted into the outer tube, the rod being capable of moving in the axial direction; a bump cushion attached to an outer periphery of the rod that protrudes from the outer tube; a synthetic resin bump stopper formed in a cap shape and fitted to one end in the axial direction of the outer tube, the bump stopper being configured to be abutted by the bump cushion during maximum compression; and a sacrificial corrosion part disposed between the outer tube and the bump stopper, the sacrificial corrosion part being configured to contact a metal surface of the outer tube. The sacrificial corrosion part is made of a metal having a higher ionization tendency than the outer tube, and thereby corrosion of members is suppressed.
Abstract:
A shock absorber includes a telescopic tube member configured to include a vehicle body side tube and a vehicle wheel side tube, a cap member that closes an upper side opening of the vehicle body side tube, a cylinder erected in an axial center portion of the vehicle wheel side tube, a piston rod held by the cap member and configured to enter and exit the cylinder, a reservoir formed between the tube member and the cylinder, a cap interior passage formed in the cap member and configured to connect the rod interior passage to the reservoir, a plurality of valve bodies provided in series or in parallel midway in the cap interior passage, and a plurality of adjusters attached to the cap member and configured to be capable of adjusting a valve opening pressure or an opening amount of the plurality of valve bodies.
Abstract:
A fluid pressure control apparatus includes a pilot control valve configured to control a pilot pressure guided from a pilot pump to the control valve and a load retaining mechanism installed in the main passage. The load retaining mechanism includes an operated check valve configured to permit a flow of the working fluid from the load-side pressure chamber to the control valve in accordance with a back pressure and a switch valve configured to switch an action of the operated check valve. The switch valve has a discharge position configured to discharge the working fluid in a back pressure chamber when the pilot pressure has been guided from the pilot control valve. When the switch valve is set to the discharge position, the working fluid in the back pressure chamber is discharged to a tank via a drain port of the pilot control valve.
Abstract:
A fluid pressure cylinder includes a cylinder tube, a piston rod, and a displacement sensor. A bottom portion of the cylinder tube has: a pin hole formed in a direction orthogonal to a center axis; and a through hole penetrating the bottom portion through the pin hole. The displacement sensor has: a sensor body disposed on inner side of the pin hole in the through hole; a sensor rod provided so as to extend from the sensor body; and an annular magnet relatively movable with respect to the sensor rod. The through hole has: a reduced-diameter portion; and a female screw portion that has a female screw formed on an inner circumference of the female screw portion. The sensor body is fixed by being pressed by a plug that is screwed into the female screw portion and by being engaged with the reduced-diameter portion.