Abstract: An electro-hydraulic circuit includes a supply line that connects between a hydraulic supply device that supplies hydraulic fluid and a driving part to be driven by a hydraulic pressure of the hydraulic fluid; a switching valve disposed in the supply line to switch between switching lines for the hydraulic fluid supplied to the driving part; a pilot hydraulic line connected to the switching valve to supply the hydraulic fluid for switching between the switching lines; a check valve disposed in the pilot hydraulic line; a solenoid valve disposed in the pilot hydraulic line to change a supply state of the hydraulic fluid to the switching valve; a sealing material disposed in the switching valve to seal the hydraulic fluid; and a relief valve disposed in the pilot hydraulic line to release the pilot hydraulic pressure

Abstract: A switching valve includes a sleeve on which a plurality of ports are disposed; a spool that is disposed inside the sleeve to move in an axial direction by a pilot hydraulic pressure to switch between switching lines each serving as a flow channel for hydraulic fluid that is formed by a combination of the ports; a first energizing unit that energizes the spool against the pilot hydraulic pressure; a relief hole that is disposed on the spool to discharge the hydraulic fluid with the pilot hydraulic pressure; a valve body that closes the relief hole; and a second energizing unit that energizes the valve body toward the relief hole of the spool against the pilot hydraulic pressure, and when the pilot hydraulic pressure exceeds a predetermined value, opens the relief hole.

Abstract: A multifunction relief valve includes a relief chamber having an introduction port and a relief port for introducing and relieving pressure fluid; a back pressure chamber formed on one end side of the relief chamber; a piston which is movably provided in the back pressure chamber and divides the back pressure chamber into a first back pressure chamber and a second back pressure chamber; a first spring which is provided in the first back pressure chamber and exerts a biasing force in a direction in which the relief port is closed; a second spring which is provided in the second back pressure chamber and biases the piston in the direction in which the relief port is closed; and a pilot pressure supply port formed in the first back pressure chamber. The pressure fluid introduced into the first back pressure chamber via the pilot pressure supply port changes the relief pressure.

Abstract: The present invention provides a technology for downsizing fluid pressure equipment including a fluid pressure pump and a radiator. The hydraulic pump unit 3 includes: a hydraulic pump 4; a motor 5 which drives the hydraulic pump 4; a cooling fan 7 which is connected to an output shaft 5a of the motor 5 and generates a flow of cooling air 6 to cool the motor 5; and a radiator 8 which receives heat from the hydraulic oil. The motor 5 and the radiator 8 are overlapped with the cooling fan 7, when viewed from the axial direction of the output shaft 5a of the motor 5.

Abstract: A multifunction relief valve 1 includes: a relief chamber 2 having an introduction port 7 and a relief port 8 for introducing and relieving pressure fluid; a back pressure chamber 3 formed on one end side of the relief chamber 2; a piston 4 which is movably provided in the back pressure chamber 3 and divides the back pressure chamber 3 into a first back pressure chamber 3a and a second back pressure chamber 3b; a first spring 5 which is provided in the first back pressure chamber 3a and exerts a biasing force in a direction in which the relief port 8 is closed; a second spring 6 which is provided in the second back pressure chamber 3b and biases the piston 4 in the direction in which the relief port 8 is closed; and a pilot pressure supply port 9 formed in the first back pressure chamber 3a. The pressure fluid introduced into the first back pressure chamber 3a via the pilot pressure supply port 9 changes the relief pressure.

Abstract: The present invention provides a technology for downsizing fluid pressure equipment including a fluid pressure pump and a radiator. The hydraulic pump unit 3 includes: a hydraulic pump 4; a motor 5 which drives the hydraulic pump 4; a cooling fan 7 which is connected to an output shaft 5a of the motor 5 and generates a flow of cooling air 6 to cool the motor 5; and a radiator 8 which receives heat from the hydraulic oil. The motor 5 and the radiator 8 are overlapped with the cooling fan 7, when viewed from the axial direction of the output shaft 5a of the motor 5.