摘要:
A pressurized fluid feed system including a pressure compensating valve and directional control valve disposed between a hydraulic pump and a boom cylinder, and a pressure compensating valve and a directional control valve disposed between the hydraulic pump and a turning motor. Each pressure compensating valve comprise a check valve section and a pressure reduction valve section. The check valve section has an inlet port connected to the said hydraulic pump, an outlet port connected to the directional control valve, a spool for establishing and blocking communication between the inlet and outlet ports and a pressure chamber for applying pressure to the spool. The pressure reduction valve section has a first port connected to the said hydraulic pump, a second port connected to a reservoir, and a spool for establishing and blocking communication between the first and second ports. The check valve section of the pressure compensating valve for the turning motor allows a variable flow rate when the turning motor is singly operated and is moved to provide a fixed throttled flow when the boom cylinder and the turning motor are simultaneously operated. There is a check valve (118) connected between the pump and both the pressure chamber (63a) and the first port (42), which prevents communication between the pump and both the pressure chamber and the first port, when the boom cylinder and the turning motor are simultaneously operated.
摘要:
In a hydraulic apparatus for traveling, a left direction switching valve is formed by forming a spool bore having a pump port, an actuator port and a return port in a first valve block, and by disposing a spool within the spool bore for establishing and blocking communication of respective of the ports to another of the ports, a right direction switching valve is formed by forming a spool bore having a pump port, an actuator port and a return port in a second valve block, and by disposing a spool within the spool bore for establishing and blocking communication of respective of the ports to another of the ports, and a switching valve is formed by forming a spool bore having a primary port and a drain port in a third valve block, and by disposing a spool within the spool bore for establishing and blocking communication between respective of the ports and another of the ports. The first and second valve blocks are respectively connected with the third valve block to communicate respective of the return ports and the drain port.
摘要:
An electric lever device includes a detent mechanism 6 between the rotational center shaft 3 and the handgrip 2. The detent mechanism 6 includes a pressing unit 10 including a through hole 11 formed in an axis C1 direction of the operation lever 1, an extension coil spring 12 inserted into the through hole 11 and balls 13a and 13b provided on both ends of the extension coil spring 12 for generating pressing force in the axis C 1 direction, and a guide unit 20 for guiding movement in a circumferential direction of the axis C 1 and changing the pressing force by changing a guide width in the axis C1 direction to apply a load to the movement of the operation lever 1 together with pulling force of a twisted coil spring 30.
摘要:
A hydraulic servo drive device includes: a pilot spool for switching supply and shutoff of oil; a servo piston slid in accordance with the pilot spool; a stroke sensor for detecting a displacement of the servo piston; a first hydraulic chamber in which oil for moving the servo piston is flowed; a first piston oil path for communicating a pump port to which oil is supplied from a pump with a first hydraulic chamber; and a discharge circulating oil path for communicating the first hydraulic chamber with a drain port.
摘要:
An electric lever device includes a detent mechanism 6 between the rotational center shaft 3 and the handgrip 2. The detent mechanism 6 includes a pressing unit 10 including a through hole 11 formed in an axis C1 direction of the operation lever 1, an extension coil spring 12 inserted into the through hole 11 and balls 13a and 13b provided on both ends of the extension coil spring 12 for generating pressing force in the axis C 1 direction, and a guide unit 20 for guiding movement in a circumferential direction of the axis C 1 and changing the pressing force by changing a guide width in the axis C1 direction to apply a load to the movement of the operation lever 1 together with pulling force of a twisted coil spring 30.
摘要:
In order to reduce hysteresis and other noise components included in the output signal characteristic of a differential pressure sensor, an elastic reaction member which operates together with a diaphragm provided in a chamber of the differential pressure sensor includes a contact portion which contacts the diaphragm, and a plurality of springs which are arranged symmetrically about the contact portion. Each of the springs is a plate shaped or linear shaped spring which is bent into the form of a letter C, U, J, or V, and has one of its ends fixed to a wall which defines the chamber, while its other end is connected to the contact portion. When the contact portion shifts together with the diaphragm, the deformations of the plurality of springs are mutually balanced, so that rotation and horizontal deviation of the contact portion with respect to the diaphragm is suppressed.
摘要:
A pressure compensation valve has a check valve portion with a check valve bore with an inlet port and an outlet port in a valve body, a valve in the check valve bore for establishing and blocking communication between the inlet port and the outlet port, a pressure reduction valve portion constructed by forming a pressure reducing valve bore having a first port, a second port and a third port and being coaxial with the check valve bore in the valve body, a spring-biased spool in the pressure reduction valve bore to define a first pressure chamber communicating with the first port and a second pressure chamber communicating with the third port at both sides, making the second port communicate with the third port by a pressure of the first pressure chamber, and blocking communication between the second port and the third port by the pressure in the second pressure chamber.
摘要:
A planarizing material comprising a resin capable of having its practical temperature for a planarizing step set at a level lower than 200.degree. C., and a melamine-type heat-curing agent and/or an epoxy-type heat-curing agent.
摘要:
A multiple valve includes first and second valve units respectively having first and second valve bodies. The first and second valve bodies have respective spool bores therein; and a respective spool is inserted in the spool bore of each of the first and second valve bodies. The first and second valve bodies of the first and second valve units also have inlet ports, tank ports, and first and second blocks having mounting holes, the blocks and a respective valve body being fixedly coupled together by means of stud bolts. The first block has a first threaded hole on one side surface thereof for receiving the stud bolt, and a second threaded hole on another side surface thereof for receiving a cover bolt. A pump passage, a main passage and a tank passage extend between the one side surface and the another side surface of the first block, and a stud bolt extends through the second block and is engaged with the first threaded hole. A cover is fixedly mounted on the another side surface of the first block by a cover bolt which is engaged with the second threaded hole, the cover having a cut-out groove therein for communicating the pump passage with the main passage.
摘要:
A steering device for a wheel loader includes a rotatable handle, a tiltable lever, a steering cylinder, a steering valve, a pump, a handle control valve, a lever control valve, and a handle prioritization valve. The steering valve controls a supply direction of operating fluid to the steering cylinder with pilot hydraulic pressure. The pump supplies operating fluid to the steering cylinder via the steering valve. The handle and lever control valves supply pilot hydraulic pressure to control the supply direction to the steering valve according to handle rotation and lever tilt, respectively. The handle prioritization valve shuts off the pilot hydraulic pressure supplied from the lever control valve to the steering valve according to a differential pressure or an absolute pressure in a hydraulic circuit produced due to operating fluid flowing through the handle control valve when the handle is operated.