Abstract: A device for controlling the variable capacity motor incorporated in a hydraulic drive vehicle, wherein a control valve for reducing the oil pressure for controlling the motor is provided to pilot hydraulic piping extending from a control pump or controlling the capacity of the motor, and changeover valves are provided for performing changeover between operation and non-operation of the pressure reduction valve. The above structure serves to control the minimum capacity of the variable capacity hydraulic motor while reducing the pressure of pilot oil introduced from the control pump and, when a pressure in the main circuit exceeds a preset value, the changeover valves operate even when the pressure reduction valve is in operation so as to cancel such operation for continuously controlling the vehicle.

Abstract: A device for controlling a vehicle for loading work and equipped with a plurality of hydraulic pumps of fixed capacity for loading work and a torque converter driven from an engine, an electronic control governor for optionally selecting output characteristic in steps for controlling output of the engine, changeover valves disposed in the circuit on the downstream side of one pump for changing over the flow of pressure oil to a drain circuit in response to working oil pressure or an electric signal, a selection switch for selecting the output characteristics, a governor controller for controlling engine the output characteristic as selected by the switch, and control circuits for actuating the changeover valves in response to the position of the selection switch.

Abstract: This invention relates to a variable capacity pump controller for an industrial vehicle such as a shovel loader using a static hydraulic driving system. In a hydraulically driven vehicle equipped with a variable capacity hydraulic pump (P), the controller of the invention includes variable throttle devices (11, 13) (21, 24), (31, 35), (41, 46) which are disposed in pilot hydraulic circuits (10, 12), (20, 22), (30, 32), (40, 42) of a pump capacity control cylinder (C) for controlling the capacity hydraulic pump (P) and operate in such a manner as to change the operation speed of the pump capacity control cylinder (C) in accordance with the oil pressure of a main hydraulic circuit (S). According to this construction, the variable throttle device operates in such a manner as to open a check valve or a throttle valve in the pilot circuit of the pump capacity control cylinder when the hydraulic driving main circuit is at a high pressure.

Abstract: A moving speed regulator for a hydraulically driven work implement capable of automatically controlling the lifting speed of a boom, and regulating the maximum lifting speed thereof in particular during earth and sand scooping operation, and also having for its object to enable the lifting speed of the boom when the boom is lifted to a position near its highest position. This regulator comprises a pilot circuit (10) having a pilot pump (P); a hydraulic circuit for driving a work implement, which includes a work implement operating valve (g) adapted to be actuated by a pilot fluid pressure from a hydraulic pilot valve (i.sub.

Abstract: A hydraulic circuit apparatus for use in construction vehicles which is arranged to reduce pressure losses that occur when all the implement operating valves are kept at their neutral positions, to reduce the power consumption by all hydraulic pumps when the hydraulic circuit for implements require only a small amount of pressurized fluid, and to transmit a command signal to unload the surplus pressurized fluid when occasion demands. The circuit comprises a surplus pressurized fluid control circuit (50) to facilitate the regulation of changes in the fluid flow rate when changing over valves. The surplus pressurized fluid control circuit (50) has a pilot actuated type unloading valve (11) provided in a surplus pressurized fluid supply conduit (51) which is connected through a check valve 20 to a hydraulic pump (P.sub.1). The hydraulic pump (P.sub.1) is for the exclusive use of the implement. The conduit (51) is also connected to a drain conduit (Ct).

Abstract: There is disclosed an apparatus which controls a variable delivery motor installed on a hydraulically operated vehicle in such a way that the maximum vehicle speed can be continuously varied without sacrificing the performance of the nonstep variable speed, hydraulically operated vehicle. The apparatus includes a hydraulic pump (1) connected with the variable delivery hydraulic motor (2) by main circuits (24, 25), a cylinder (31) that controls the motor (2), a control pump (3) delivering pilot pressure, and a vehicle speed limiter (122). Higher pressure is produced inside the main circuits. The limiter limits the minimum capacity of the motor (2), depending on the higher pressure and also on the pilot pressure acting on the cylinder (31).

Abstract: A loading/unloading vehicle having booms and a bucket carried thereon such as a shovel loader, a wheel loader or the like vehicle detects that a true bucket-to-ground angle coincides with a preset angle after the vehicle starts automatic turning movement of the bucket. When the coincidence is detected, the automatic turning movement of the bucket is interrupted. Thereafter, a differential value between the true bucket-to-ground angle and the preset angle is determined, if any and then the bucket angle is corrected so as to allow the differential value to be reduced to zero. Consequently, the bucket is held at the preset angle after the bucket stops, even though the booms continue to be turned.

Abstract: The present invention is concerned with a working machine in the form of a construction machine including booms 2 and a bucket 4 such as a wheel loader, a shovel loader or the like. When a scooping operation is performed by alternately repeating a tilting operation with the use of only a bucket operation lever 16 while a boom operation lever 15 is held at a boom kick-out position, a lifting operation for the booms 2 and a tilting operation for the bucket 4 while the boom operation lever 15 is shifted to a neutral position, a lift speed of the booms 2 is variably controlled to a speed corresponding to a tilt speed of the bucket or an angle of the booms whereby the tilt speed is harmonized with the boom speed.

Abstract: The present invention is concerned with a working machine in the form of a construction machine including booms 2 and a bucket 4 such as a wheel loader, a shovel loader or the like. When a scooping operation is performed by alternately repeating a tilting operation with the use of only a bucket operation lever 16 while a boom operation lever 15 is held at a boom kick-out position, a lifting operation for the booms 2 and a tilting operation for the bucket 4 while the boom operation lever 15 is shifted to a neutral position, a lift speed of the booms 2 is variably controlled to a speed corresponding to a tile speed of the bucket or an angle of the booms whereby the tilt speed is harmonized with the boom speed.

Abstract: A hydraulic steering apparatus for a construction vehicle, which has been developed for the purpose of improving the steering control performance of an apparatus of this kind by preventing the occurrence of nonsynchronousness between a steering wheel and a knuckle arm or some other pivotable member, and eliminating a dead zone ascribed to an operation of a link mechanism. This steering apparatus has a pilot valve (2) connected directly to a steering wheel, a main control valve (7) provided separately from the pilot valve and adapted to be operated by a pressure oil sent from a pilot pump (9) which is controlled by the pilot valve, a steering cylinder (6) to which a pressure oil is supplied from a main pump (8) via the main control valve, and a feedback line (4) connected between a pivotable member (5), such as a knuckle arm connected pivotably to a piston rod in the steering cylinder and a spool in the pilot valve.

Abstract: An air conditioning device installed in a cabin of an earth-moving vehicle is equipped with a housing which has internal and external air intake ports to intake the internal air and the external air, a housing for containing cooling units and heating units, and a housing for mixing the air, that are located at the back of the driver's seat in the cabin, on either one side of the driver's seat, and under the driver's seat, respectively. The air is blown by a blower provided in the housing which intakes the internal air and the external air. The cold air or the hot air which has passed through the cooling units or the heating units is blown from the blow ports provided on the front side of the housing for mixing the air, and from the blow ports provided in the dash board in the cabin.