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:
A travel vibration suppressing device 20 is structured such that a directional control valve 30 for a bucket, a directional control valve 29 for a boom, a ride control valve 31 and a boom speed increasing valve 33 are integrally arranged in a laminated manner by an internal piping. The ride control valve 31 communicates or cuts off a bottom chamber 11a of a boom cylinder 11 and an accumulator 27. The boom speed increasing valve 33 supplies a discharge pressure of a hydraulic pump 21 to the bottom chamber 11a or a head chamber 11b or connects the to the bottom chamber 11a or the head chamber 11b to a tank 23.
摘要:
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.
摘要:
Provided are a variable geometry turbocharger in which a drain pipe from a hydraulic servo drive device can be omitted and in which a member for transmitting power of the hydraulic servo drive device can be efficiently lubricated, and a method of returning oil from the hydraulic servo drive device. The variable geometry turbocharger includes a slide mechanism for changing an opening degree of a nozzle, the hydraulic servo drive device for driving the slide mechanism by hydraulic pressure, and drain flow paths for delivering oil exhausted from the hydraulic servo drive device into an oil return chamber adjacent to a turbocharger body.
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 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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A rotor and a seat mounted on a first shell is disposed between an annular first shell and an annular second shell both constituting a damper case, thereby forming a rotary damper device. A damper lever on which the rotor is mounted is hooked on a fixing pin fixed to a body. Viscous fluid such as highly viscous oil is charged into a damper chamber formed between the rotor and the seat, and a viscous resistance is applied to the rotor and the seat. In a state in which a rotation center of the rotary damper device is deviated from a rotation center of the shaft which is rotated by the operating lever, the damper case is fixed to a flange portion of the shaft, the rotor and the seat are allowed to rotate relatively to each other by an inclining operation of the operating lever, and a resistance force from the rotary damper device is applied to the operating lever.