Abstract: A control unit for a work machine that allows automatically obtaining optimal operability even when the weight of a work arm in the work machine is changed. In a work machine where at least a part of a work arm to be operated by a fluid pressure actuator is provided so as to be replaceable, a control unit for a work machine includes: a pilot-operated control valve that controls the fluid pressure actuator; a proportional solenoid valve that pilot-controls the pilot-operated control valve by a pilot control pressure according to an electrical signal corresponding to a manual operation amount; a measuring means that measures a weight of at least the part of the work arm; and a controller that converts characteristics between the manual operation amount and the pilot control pressure of the proportional solenoid valve to characteristics according to the weight of the work arm measured by the measuring means.

Abstract: A vibration control mount apparatus capable of absorbing an initial pushing-up load based on a shock and capable of promptly damping a residual vibration generated after the shock. The vibration control mount apparatus includes a case body mounted on a turning frame, a mount rubber is mounted on the case body. A magnetic viscous fluid of which viscosity is changed by a magnetic filed is sealed in a sealing chamber in the case body. A movable body supported by the mount rubber has a damper plate which moves while receiving resistance from the magnetic viscous fluid in the sealing chamber. Viscosity variable controlling device forms the magnetic field in accordance with vibration acceleration detected by the acceleration detecting device to change the viscosity of the magnetic viscous fluid.

Abstract: An oil cooler for cooling hydraulic oil that has increased in temperature due to energy loss in a hydraulic circuit a radiator for cooling engine cooling water that has increased in temperature as a result of cooling an engine and an ATAAC for cooling engine intake air that has increased in temperature as a result of being compressed by a turbocharger, are provided with heat pipes for vaporizing low-boiling medium by absorbing heat from the oil cooler the radiator and the ATAAC. A power recovery turbine is rotated by energy provided by vaporized low-boiling medium is provided for the engine. A low-boiling medium circuit is provided so as to drive the turbine by feeding the low-boiling medium that has been vaporized by waste heat energy. The low-boiling medium circuit includes the heat pipes of the oil cooler the radiator, and the ATAAC, as well as the turbine.

Abstract: A pilot-operated proportional control electromagnetic relief valve has a needle guide portion snugly fitted around the outer surface of a needle. The needle guide portion guides vertical movement of the needle, and is located at the center of a stopper so as to be coaxial with the stopper. A cylindrical inner wall portion of the stopper is so bored in the lower part of the adapter as to be coaxial with the needle guide portion. A cylindrical outer wall portion to be snugly fitted in the cylindrical inner positioning wall portion is so formed around the outer surface of a seat as to be coaxial with the seat portion. The outer circumferential surface of the needle is snugly fitted in the needle guide portion of the adapter so that the needle guide portion guides the axial travel of the needle, and the cylindrical inner wall portion of the adapter and the cylindrical outer wall portion of the seat are snugly fitted together.

Abstract: According to the present invention, an electromagnetic actuator comprises a closed magnetic circuit consisting of a magnetic stationary member in a closed loop shape; an electric coil for energizing the closed magnetic circuit; and a movable member made of a permanent magnet, which member is bridgingly connected between a pair of restricted sections, facing each other, of the closed magnetic circuit through gaps so as to apply magnetomotive force to the closed magnetic circuit.