Setting a system pressure for a hydraulically actuated clutch comprises

a) Providing a system comprising a pump drivable by an electrically operated motor controlled by a control unit that senses a motor current and rotational speed and a system temperature is determined;

b) a characteristic diagram is provided specifying values for at least the motor current and rotational speed for different system operating points;

c) Accessing the characteristic diagram while operating a vehicle;

d) Sensing at least the motor current and rotational speed at at least a first operating point and determining the system temperature ;

e) Comparing the values, acquired in step d) for the current and speed with the values for the current and rotational speed from the characteristic diagram according to step b);

f) Adapting the characteristic diagram for the system on the basis of the parameters determined in step d).

Setting a system pressure for a hydraulically actuated clutch comprises

a) Providing a system comprising a pump drivable by an electrically operated motor controlled by a control unit that senses a motor current and rotational speed and a system temperature is determined;

b) a characteristic diagram is provided specifying values for at least the motor current and rotational speed for different system operating points;

c) Accessing the characteristic diagram while operating a vehicle;

d) Sensing at least the motor current and rotational speed at at least a first operating point and determining the system temperature ;

e) Comparing the values, acquired in step d) for the current and speed with the values for the current and rotational speed from the characteristic diagram according to step b);

f) Adapting the characteristic diagram for the system on the basis of the parameters determined in step d).

In an engine, a cylinder block and a cylinder head are connected with a crankcase in a forwardly inclined posture. A dual clutch connects or disconnects a transmission path of power of the engine to a transmission. An actuator chamber houses an actuator that controls a hydraulic pressure of the dual clutch. The actuator chamber is disposed on an upper surface of the cylinder block at a position posterior to the cylinder head and anterior to the crankcase in a vehicle longitudinal direction.

In an engine, a cylinder block and a cylinder head are connected with a crankcase in a forwardly inclined posture. A dual clutch connects or disconnects a transmission path of power of the engine to a transmission. An actuator chamber houses an actuator that controls a hydraulic pressure of the dual clutch. The actuator chamber is disposed on an upper surface of the cylinder block at a position posterior to the cylinder head and anterior to the crankcase in a vehicle longitudinal direction.

A plurality of inductive loads (105) are connectable in parallel with one another between first and second terminals (120, 125), to which a controllable voltage (205) is applied. A method (300, 400) for operating the loads (105) includes the steps of detecting (305, 405) the connection of a previously non-energized load (105) between the terminals (120, 125); setting (310, 410, 435) the voltage (205) to a predetermined first value (210), and, after the lapse of a predetermined time interval (315, 415), adjusting the voltage (205) to a predetermined second value (215), with the second value (215) being lower than the first value (210).

A clutch control device and a clutch control method are capable of preventing progress of wear and damage of a pneumatic clutch actuator. The clutch control device that controls the operation of a pneumatic clutch actuator to disconnect a clutch is characterized by setting a stroke amount of a piston corresponding to a disconnection position of the clutch as a final target stroke amount, setting other stroke amounts different from the final target stroke amount as intermediate target stroke amounts, and controlling the operation of the piston in a stepwise manner such that an actual stroke amount of the piston is matched with the intermediate target stroke amounts and is thereafter matched with the final target stroke amount, thereby disconnecting the clutch.

A wheel loader includes a boom, a forward clutch, and a controller configured to control hydraulic pressure of hydraulic oil supplied to the forward clutch. The controller performs clutch hydraulic pressure control for bringing the forward clutch into a semi-engagement state by controlling the hydraulic pressure of the hydraulic oil supplied to the forward clutch on condition that the wheel loader advances while raising the boom in at least a loaded state.

A wheel loader includes a boom, a forward clutch, and a controller configured to control hydraulic pressure of hydraulic oil supplied to the forward clutch. The controller performs clutch hydraulic pressure control for bringing the forward clutch into a semi-engagement state by controlling the hydraulic pressure of the hydraulic oil supplied to the forward clutch on condition that the wheel loader advances while raising the boom in at least a loaded state.

A clutch actuating device has an actuating cylinder with piston and rod-side chamber, a multiplier cylinder with piston-side and rod-side chambers separated by a piston, a rod(s) interconnecting the pistons, and a directional control valve. The valve has a pilot port, ports in fluid connection with piston-side and rod-side chambers of the multiplier cylinder, and a port in fluid connection with a secondary source. When a first fluid pressure (P1) from a first pressure source is applied to the pilot port and rod-side chamber of the actuating cylinder, a second fluid pressure (P2) is applied to the piston-side chamber of the multiplier cylinder by the secondary source. This results in the first and second fluid pressures (P1 and P2) acting on the piston of the actuating cylinder to produce a clutch actuation fluid pressure.

A clutch actuating device has an actuating cylinder with piston and rod-side chamber, a multiplier cylinder with piston-side and rod-side chambers separated by a piston, a rod(s) interconnecting the pistons, and a directional control valve. The valve has a pilot port, ports in fluid connection with piston-side and rod-side chambers of the multiplier cylinder, and a port in fluid connection with a secondary source. When a first fluid pressure (P1) from a first pressure source is applied to the pilot port and rod-side chamber of the actuating cylinder, a second fluid pressure (P2) is applied to the piston-side chamber of the multiplier cylinder by the secondary source. This results in the first and second fluid pressures (P1 and P2) acting on the piston of the actuating cylinder to produce a clutch actuation fluid pressure.