Abstract: A hydraulic pump/motor includes a rotational shaft rotatably attached inside a casing, a cylinder block configured to rotate together with the rotational shaft, a plurality of pistons, a swash plate, a valve plate, and a rotation detection mechanism. The rotation detection mechanism includes a detection target section having three or more recesses formed on an outer peripheral surface of the cylinder block in a unique arrangement pattern with different arc lengths between the three continuous recesses with respect to one rotational direction of the rotational shaft and being formed so as not to include the unique arrangement pattern with respect to the other rotational direction of the rotational shaft, each of the three or more recesses having a cross section having a same semicircular shape perpendicular to a direction of the rotational shaft; and a rotation sensor arranged in the casing in a state of facing the detection target section.

Abstract: A stroke detection device for detecting, along a longitudinal direction, a stroke amount of a spool arranged in a valve main body. The stroke detection device includes: a device main body attached to the valve main body; a detection rod extending along the longitudinal direction of the spool, and movably arranged along the longitudinal direction inside the device main body, in a position where a tip end portion faces an end surface of the spool; a stroke detection unit configured to output a detection signal according to the stroke amount of the detection rod with respect to the device main body; and an attracting unit arranged in the tip end portion of the detection rod, the attracting unit being attracted to the end surface of the spool by magnetic force.

Abstract: A blocking configuration of an oil pressure circuit hole includes a plug screwed together with an aperture end portion of the oil pressure circuit hole provided to a main body. The plug includes: a shaft portion; an external thread portion disposed on a leading end of the shaft portion; an O-ring mounted on an outer periphery of a base end portion of the shaft portion and pressed between the outer periphery of the shaft portion and an inner periphery of the oil pressure circuit hole to seal them; a flange portion having an external diameter larger than that of the shaft portion and disposed on a part of a base end side of a storage groove on which the O-ring is mounted; and a polygonal column-shaped head portion on which a tightening tool is mounted and disposed on a part of a base end side of the flange portion.

Abstract: A blocking configuration of an oil pressure circuit hole includes a plug screwed together with an aperture end portion of the oil pressure circuit hole provided to a main body. The plug includes: a shaft portion; an external thread portion disposed on a leading end of the shaft portion; an O-ring mounted on an outer periphery of a base end portion of the shaft portion and pressed between the outer periphery of the shaft portion and an inner periphery of the oil pressure circuit hole to seal them; a flange portion having an external diameter larger than that of the shaft portion and disposed on a part of a base end side of a storage groove on which the O-ring is mounted; and a polygonal column-shaped head portion on which a tightening tool is mounted and disposed on a part of a base end side of the flange portion.

Abstract: A steering device for a wheel loader includes a handle for steering, a lever for steering, a steering cylinder, a steering valve that controls a direction of operating fluid to the steering cylinder, and a pump that supplies operating fluid to the steering cylinder via the steering valve. The steering device further includes a handle control valve that controls the supply direction of the operating fluid according the handle, a lever electromagnetic control valve that controls the supply direction of operating fluid according to the lever, and a handle prioritization valve that shuts off a pilot hydraulic pressure supplied from the lever electromagnetic control valve to the steering valve according to a pressure produced by operating fluid flowing through the handle control valve when the handle is operated. Communication between the lever electromagnetic control valve and the steering valve is allowed when only the lever electromagnetic control valve is operated.

Abstract: A steering device for a wheel loader includes a handle for steering, a lever for steering, a steering cylinder, a steering valve that controls a direction of operating fluid to the steering cylinder, and a pump that supplies operating fluid to the steering cylinder via the steering valve. The steering device further includes a handle control valve that controls the supply direction of the operating fluid according the handle, a lever electromagnetic control valve that controls the supply direction of operating fluid according to the lever, and a handle prioritization valve that shuts off a pilot hydraulic pressure supplied from the lever electromagnetic control valve to the steering valve according to a pressure produced by operating fluid flowing through the handle control valve when the handle is operated. The handle prioritization valve includes a switching valve and a priority control valve switchable between a handle stage and a lever stage.

Abstract: A steering device for a wheel loader includes a handle for steering, a lever for steering, a steering cylinder, a steering valve that controls a direction of operating fluid to the steering cylinder, a pump that supplies operating fluid to the steering cylinder via the steering valve, and a return oil passage connected to a tank. The steering device further includes a handle control valve that controls the supply direction of the operating fluid according the handle, a lever electromagnetic control valve that controls the supply direction of operating fluid according to the lever, and a handle prioritization valve that shuts off a pilot hydraulic pressure supplied from the lever electromagnetic control valve to the steering valve according to a pressure produced by operating fluid flowing through the handle control valve when the handle is operated. The handle prioritization valve includes a throttle arranged in the return oil passage.

Abstract: A steering device for a wheel loader includes a handle for steering, a lever for steering, a steering cylinder, a steering valve that controls a direction of operating fluid to the steering cylinder, a pump that supplies operating fluid to the steering cylinder via the steering valve, and a return oil passage connected to a tank. The steering device further includes a handle control valve that controls the supply direction of the operating fluid according the handle, a lever electromagnetic control valve that controls the supply direction of operating fluid according to the lever, and a handle prioritization valve that shuts off a pilot hydraulic pressure supplied from the lever electromagnetic control valve to the steering valve according to a pressure produced by operating fluid flowing through the handle control valve when the handle is operated. The handle prioritization valve includes a throttle arranged in the return oil passage.

Abstract: A steering device for a wheel loader includes a handle for steering, a lever for steering, a steering cylinder, a steering valve that controls a direction of operating fluid to the steering cylinder, and a pump that supplies operating fluid to the steering cylinder via the steering valve. The steering device further includes a handle control valve that controls the supply direction of the operating fluid according the handle, a lever electromagnetic control valve that controls the supply direction of operating fluid according to the lever, and a handle prioritization valve that shuts off a pilot hydraulic pressure supplied from the lever electromagnetic control valve to the steering valve according to a pressure produced by operating fluid flowing through the handle control valve when the handle is operated. Communication between the lever electromagnetic control valve and the steering valve is allowed when only the lever electromagnetic control valve is operated.

Abstract: A steering device for a wheel loader includes a handle for steering, a lever for steering, a steering cylinder, a steering valve that controls a direction of operating fluid to the steering cylinder, and a pump that supplies operating fluid to the steering cylinder via the steering valve. The steering device further includes a handle control valve that controls the supply direction of the operating fluid according the handle, a lever electromagnetic control valve that controls the supply direction of operating fluid according to the lever, and a handle prioritization valve that shuts off a pilot hydraulic pressure supplied from the lever electromagnetic control valve to the steering valve according to a pressure produced by operating fluid flowing through the handle control valve when the handle is operated. The handle prioritization valve includes a switching valve and a priority control valve switchable between a handle stage and a lever stage.

Abstract: 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.

Abstract: An oil filter interposed in an oil passage and configured to perform filtering of oil by causing the oil to pass through a passage hole of a filter body formed by etching, wherein an oil passing section is etched to a half of plate thickness of the filter body on one surface of the filter body, and a plurality of the passage holes are formed by etching in a region where the oil passing section is formed on the other surface of the filter body.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An oil filter interposed in an oil passage and configured to perform filtering of oil by causing the oil to pass through a passage hole of a filter body formed by etching, wherein an oil passing section is etched to a half of plate thickness of the filter body on one surface of the filter body, and a plurality of the passage holes are formed by etching in a region where the oil passing section is formed on the other surface of the filter body.

Abstract: An engine includes a variable geometry turbocharger, an EGR valve device, a hydraulic servo drive device that drives the variable geometry turbocharger, a hydraulic servo drive device that drives the EGR valve device, an electronic proportional control valve (EPC valve) that supplies pilot pressure oil to the hydraulic servo drive device, and an electronic proportional control valve (EPC valve) that supplies pilot pressure oil to the hydraulic servo drive device, the EPC valves being attached to the EGR valve device.

Abstract: A hydraulic servo drive device for driving a swing mechanism of a variable geometry turbocharger includes a servo piston connected to a driveshaft of the swing mechanism and a pilot spool that is accommodated in a center hole of the servo piston and slides by pilot pressure. A first hydraulic chamber to and from which pressure oil flows are provided in a housing. The servo piston separately includes a pressure port for introducing pressure oil from an outside, a first piston port for intercommunicating the center hole and the first hydraulic chamber, a second piston port for intercommunicating the center hole and the second hydraulic chamber, and a return port for exiting pressure oil.

Abstract: A hydraulic servo drive device for driving a slide mechanism of a variable geometry turbocharger includes a servo piston connected to a driveshaft of the slide mechanism and a pilot spool that is accommodated in a center hole of the servo piton and slides by pilot pressure. A first hydraulic chamber and a second hydraulic chamber to and from which pressure oil flows are provided in a housing. The servo piston separately includes a pressure port for introducing pressure oil from an outside, a first piston port for intercommunicating the center hole and the first hydraulic chamber, a second piston port for intercommunicating the center hole and the second hydraulic chamber, and a return port for exiting pressure oil.

Abstract: An EGR valve device includes a valve housing of which inside exhaust gas passes through, a poppet valve as a valve body accommodated in the valve housing, and a hydraulic servo actuator for driving the poppet valve to be opened and closed. The hydraulic servo actuator is provided by a three-port or four-port servo valve.