Abstract: Brake mechanisms (33) that apply braking to rotations of left and right rotational shafts (25) each include a projecting part (40) that faces a partition wall (15A) of a brake case (15) and projects radially inward from an inner diameter side of a piston (37), an engaging member (41) that is arranged in the inner diameter side of the piston (37) in a state of being movably engaged with the projecting part (40) by a predetermined dimension in the left-right direction, and a pin member (42) that is provided between the partition wall (15A) of the brake case (15) and the engaging member (41). A frictional resistance between the pin member (42) and the partition wall (15A) is set to a value smaller than a pressing force of the piston (37) at the braking. The projecting part (40) is provided with an engaging member insertion groove (40A) that the pin member (42) penetrates in the left-right direction, and the engaging member (41) is movably engaged with the projecting part (40) in the left-right direction.

Abstract: In a hydraulic drive system, hydraulic oil discharged from an actuator pump is supplied to an actuator via an actuator drive circuit. In the hydraulic drive system, the hydraulic oil discharged from a fan pump is supplied to a cooling fan motor via a fan drive circuit, and the cooling fan motor rotates a cooling fan at a rotational speed corresponding to the flow rate of the hydraulic oil supplied to the cooling fan motor. A merge circuit connects the actuator drive circuit and the fan drive circuit to each other to cause the hydraulic oil flowing through the actuator drive circuit to merge into the hydraulic oil flowing through the fan drive circuit. When the merge condition is satisfied, the controller controls the merge circuit to connect the actuator drive circuit and the fan drive circuit to each other.

Abstract: A hydraulic control device includes: a hydraulic pump connected in parallel to steering and boom cylinders; a steering control valve that controls the direction of operating oil flowing through the steering cylinders; a boom control valve that connects the hydraulic pump to a tank when the valve is at a neutral position and controls the direction of the oil flowing through the boom cylinders when the valve is at an offset position; a meter-in pressure compensator that increases flow rate of the oil flowing through a variable restrictor of the steering control valve in accordance with pressure in front of and behind the restrictor; and a bleed-off pressure compensator that decreases flow rate of the oil flowing through the boom control valve in accordance with the increase in pressure of the oil flowing through the steering cylinders to maintain the predetermined pressure of the oil in the steering control circuit.

Abstract: A lockup device (63) includes a lockup clutch (64) for establishing connection between a rotating body (44) of a torque converter (41) and a transmission shaft (55), a lockup control valve (70) that controls supply/discharge of pressurized oil from a hydraulic pump (69) to/from the lockup clutch (64), and a lockup oil passage (75) that introduces pressurized oil from the lockup control valve (70) to the lockup clutch (64). The lockup control valve (70) is arranged on an outer side face (18B) of an intermediate casing (18) in a position of radially overlapping the transmission shaft (55) in a radial direction of the transmission shaft (55). Further, a casing side oil passage (76) constituting the lockup oil passage (75) is formed as a linear oil passage that linearly extends in the radial direction of the transmission shaft (55) between the lockup control valve (70) and the transmission shaft side oil passage (77).

Abstract: A hydraulic drive system includes a pump, a steering actuator, a loading/unloading apparatus actuator, a drive device, a relief valve, and an input unit. The drive device: flows hydraulic oil from the pump to the loading/unloading apparatus actuator when an operating tool is operated; flows the hydraulic oil from the pump to the steering actuator when a steering has become an operated state from a non-operated state regardless of an operation of the operating tool; and causes the hydraulic oil from the pump to be discharged to a tank via the relief valve to increase the torque of an engine when an increase instruction is inputted to the input unit and the steering is in a non-operated state.

Abstract: A work vehicle including a front work device, contains: a variable displacement hydraulic pump that is driven by an engine and supplies pressure oil to an actuator that drives the front work device; an exhaust gas purification device that purifies nitrogen oxide in exhaust gas discharged from the engine using a reducing agent solution stored in a reducing agent tank; a remaining amount detection device that detects a remaining amount of the reducing agent solution in the reducing agent tank; and a control unit that decreases output torque of the engine and also decreases a rotational speed of the engine in a rated point according to decrease of the remaining amount of the reducing agent solution detected by the remaining amount detection device.

Abstract: A wheel loader includes: a driver's cab; an engine; a chassis, at sides of which tires are provided; an engine room in which the engine is mounted on the chassis, the engine room being provided behind the driver's cab; front portion structures respectively standing at left and right positions of a surface of the engine room, the surface being located at the driver's cab side; rear portion structures respectively standing at left and right positions of a surface of the engine room, the surface being opposite to the surface located at the driver's cab side; and a coupling structure that couples upper portions of the front portion structures to upper portions of the rear portion structures and forms a peripheral device installation space at an upper portion of the engine.

Abstract: A wheel loader includes: a driver's cab; an engine; a chassis, at sides of which tires are provided; an engine room in which the engine is mounted on the chassis, the engine room being provided behind the driver's cab; front portion structures respectively standing at left and right positions of a surface of the engine room, the surface being located at the driver's cab side; rear portion structures respectively standing at left and right positions of a surface of the engine room, the surface being opposite to the surface located at the driver's cab side; and a coupling structure that couples upper portions of the front portion structures to upper portions of the rear portion structures and forms a peripheral device installation space at an upper portion of the engine.

Abstract: A wheel loader includes: a driver's cab; an engine; a chassis, at sides of which tires are provided; an engine room in which the engine is mounted on the chassis, the engine room being provided behind the driver's cab; front portion structures respectively standing at left and right positions of a surface of the engine room, the surface being located at the driver's cab side; rear portion structures respectively standing at left and right positions of a surface of the engine room, the surface being opposite to the surface located at the driver's cab side; and a coupling structure that couples upper portions of the front portion structures to upper portions of the rear portion structures and forms a peripheral device installation space at an upper portion of the engine.

Abstract: A construction machine comprises an electric motor/generator; an engine; an epicyclic gearing for rotating the electric motor/generator reversely when speed of a rotation output to a drive wheel is zero during running of the engine; a transmission configured to switch between a forward driving gear position and a backward driving gear position; and a controller for controlling the engine, the electric motor/generator and the transmission, based on at least an accelerator opening, and a state of charge in an electric storage device; the controller being configured to switch the forward driving gear position or the backward driving gear position to a direction opposite to a direction in which the construction machine is moving, and cause the electric motor/generator to generate reverse torque in a power running mode, when the electric storage device is in a fully charged state and the accelerator has been pressed down by a driver.

Abstract: A steering system, in a state where a first steering means is not operated, a third signal pressure output means outputs a third signal pressure in response to a second signal pressure fed to the third signal pressure output means, and feeding and discharging control means operates based in the third signal pressure, while in a state where the first steering means is operated, the third signal pressure output means stops outputting of the third signal pressure regardless of whether or not the second signal pressure is fed to the third signal pressure output means, and the feeding and discharging control means operates based on the first signal pressure.

Abstract: A steering system, in a state where a first steering means is not operated, a third signal pressure output means outputs a third signal pressure in response to a second signal pressure fed to the third signal pressure output means, and feeding and discharging control means operates based in the third signal pressure, while in a state where the first steering means is operated, the third signal pressure output means stops outputting of the third signal pressure regardless of whether or not the second signal pressure is fed to the third signal pressure output means, and the feeding and discharging control means operates based on the first signal pressure.

Abstract: A construction machine comprises an electric motor/generator; an engine; an epicyclic gearing for rotating the electric motor/generator reversely when speed of a rotation output to a drive wheel is zero during running of the engine; a transmission configured to switch between a forward driving gear position and a backward driving gear position; and a controller for controlling the engine, the electric motor/generator and the transmission, based on at least an accelerator opening, and a state of charge in an electric storage device; the controller being configured to switch the forward driving gear position or the backward driving gear position to a direction opposite to a direction in which the construction machine is moving, and cause the electric motor/generator to generate reverse torque in a power running mode, when the electric storage device is in a fully charged state and the accelerator has been pressed down by a driver.