Abstract: 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.

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: 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: 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: 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.

Abstract: 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.

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 piston 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: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present invention lowers energy loss while at the same time enhancing the responsiveness of a steering control system. When a steering controller is operated rapidly, the aperture area of a steering flow control valve 4 rapidly increases, and the differential pressure (Pp?-PL) across the steering flow control valve 4 rapidly decreases. When the differential pressure (Pp?-PL) across the steering flow control valve 4 rapidly decreases, a flow control valve 6 is biased by the spring force of a spring 6f and quickly moves to the side of a valve position 6b to increase the differential pressure (Pp?-PL) and make it correspond to a set pressure. Thus, the pressure oil of a surplus flow ?, which up to this point has been flowing to a discharge oil line 7, is quickly supplied from the flow control valve 6 to a steering hydraulic cylinder 5 via the steering flow control valve 4. Thus, an output Q? starts quickly relative to an input St.

Abstract: The present invention intends to provide a hydraulic signal output device having a smaller installation space, and thereby enabling to make an installation space of hydraulic machines in an operation room smaller and that of other than the hydraulic machines larger. In addition to this, the present invention intends to allow externally restricting an operation in the operation room. In order to attain the intentions, in a hydraulic signal output device of the present invention, a PPC valve, an EPC valve and a shuttle valve are integrally formed. In one invention, in addition to the above, a pressure oil output port in a pressure-reducing valve in the PPC valve is communicated with a pressure oil input port of a switching valve in an electromagnetic valve, and a pressure oil output port of the switching valve in the electromagnetic valve is communicated with a pilot pipe line.

Abstract: The present invention lowers energy loss while at the same time enhancing the responsiveness of a steering control system. When a steering controller is operated rapidly, the aperture area of a steering flow control valve 4 rapidly increases, and the differential pressure (Pp?-PL) across the steering flow control valve 4 rapidly decreases. When the differential pressure (Pp?-PL) across the steering flow control valve 4 rapidly decreases, a flow control valve 6 is biased by the spring force of a spring 6f and quickly moves to the side of a valve position 6b to increase the differential pressure (Pp?-PL) and make it correspond to a set pressure. Thus, the pressure oil of a surplus flow ?, which up to this point has been flowing to a discharge oil line 7, is quickly supplied from the flow control valve 6 to a steering hydraulic cylinder 5 via the steering flow control valve 4. Thus, an output Q? starts quickly relative to an input St.

Abstract: A monolever operating device that inclines in a two-dimensional manner including at least a front and rear direction and a right and left direction. A drive signal generating unit contained within a drive signal generating body for outputting two drive signals to components in the front and rear direction and in the right and left direction in accordance with an orientation and an amount of inclination of the monolever. The device further includes a universal joint mounted to support the monolever in an inclinable manner, a mount plate for mounting the drive signal generating body mounted thereto to a vehicle body, and a monolever bearing member provided on an upper surface of the mount plate and provided with lever bearing portions and boot holding portions alternately arranged adjacent to each other in a circumferential direction.

Abstract: 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.

Abstract: An oil pressure signal output device which is easy to be integrated with an additional EPC valve and can be manipulated inside/outside a driver's cab. The device makes it possible to reduce the occupied area of hydraulic apparatuses in the driver's cab and to extend a space other than that of hydraulic apparatuses. In the device: the manual oil pressure signal output device for controlling a first hydraulic apparatus, the first electric oil pressure signal output device and the selecting output means are integrated; a second electric oil pressure signal output device for controlling a second hydraulic apparatus abuts against the first electric oil pressure signal output device is removably provided.

Abstract: It is designed that an oil pressure signal can be output by operating an operation lever in a twisting direction; a structure can be made simple and its assembly and adjustment are easy; an operation force can be reduced; and a layout is not restricted. It is also designed that when the operation lever is left free after it is twisted, it returns smoothly to the original neutral position. When the operation lever is twisted about the lever axis, the shaft supported by bearings is twisted. The twist of the shaft is converted into the movement in a direction to move the pistons by first and second levers, and the pistons are moved. When the pistons are moved, the oil pressure signal is output from the discharge ports. A disk plate is separated into a first disk plate to which the root of the operation lever is attached and a second disk plate which is tiltably supported by a tilting fulcrum.