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:
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 rotary pilot valve in which a force required to operate the pilot valve is reduced and especially the pilot valve can be operated with a very small operating force as in a fingertip type, and the number of parts forming the pilot valve is reduced. In a body, a tank port, a pair of pump ports, a first output port, and a second output port are formed. In a cylindrical valve, a pair of notch grooves is formed and connected with each other by a balance hole. Variable throttles are formed on a side of the tank port and a side of the pump port of the notch groove. An open area of one of the variable throttles gradually increases while an open area of the other gradually reduces by tilting of an operating lever. Pressure oil lead into the notch groove through the variable throttle is output from the first output port as an intermediate throttle pressure.
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:
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 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.