Control Apparatus for Work Machine

• US 20090301075A1
• Filed: 10/26/2006
• Published: 12/10/2009
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Kawaguchi, Tadashi, Inoue, Hiroaki, Morinaga, Jun
• Granted Patent: US 8,087,240 B2
• Time in Patent Office: Days
• US Class Current: 60/459
• CPC Class Codes: B66C 1/42 Gripping members engaging only the external or internal surfaces of the articles for handling or stripping castings or ingots during manufacture B22D29/00
• CPC Class Codes: B66F 7/04 hydraulically or pneumatically operated
• CPC Class Codes: E02F 9/2037 Coordinating the movements of the implement and of the frame
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00

Abstract

A speed of a hydraulic actuator is matched with that of an electric actuator when the hydraulic actuator and the electric actuator are concurrently actuated. When determination units (71, 72) determine that a boom hydraulic cylinder (31) and a rotation generator motor (11) are concurrently actuated based on a controlled variable of a boom control lever (41) and a controlled variable of a rotation control lever (42), a torque of the rotation generator motor (11) is restricted based on a pump discharge pressure (Pp). Therefore, for example, a torque limit command is generated and output such that a torque limit value (TL2) of the rotation generator motor (11) is decreased with a decrease in discharge pressure (Pp) of a hydraulic pump (3).

Claims

1. A control apparatus for a work machine comprising:

a hydraulic pump which is driven by an engine;

a hydraulic actuator to which pressurized oil is supplied, the pressurized oil being discharged from the hydraulic pump;

a generator motor which is coupled to an output shaft of the engine;

a storage device which accumulates electric power generated by the generator motor and supplies electric power to the generator motor;

an electric actuator which is driven by the electric power generated by the generator motor and/or the electric power accumulated in the storage device;

a determination unit which determines whether or not the hydraulic actuator and the electric actuator are concurrently actuated; and

a control unit for restricting a torque or a speed of the electric actuator when the determination unit determines that the hydraulic actuator and the electric actuator are concurrently actuated.

4. The control apparatus for a work machine according to claim 1, wherein a torque limit or a speed limit of the electric actuator is controlled to be decreased as a load on the hydraulic pump or the hydraulic actuator is decreased.

5. The control apparatus for a work machine according to claim 1, wherein the hydraulic actuator actuates work equipment, and

the electric actuator actuates an upper rotary body.

6. The control apparatus for a work machine according to claim 1, wherein the hydraulic actuator is a hydraulic actuator which includes a boom hydraulic actuator actuating a boom,

the electric actuator is an upper rotary body electric actuator actuating an upper rotary body, and

the determination unit determines whether or not a hoist rotary work is performed, in which the upper rotary body electric actuator actuating the upper rotary body so as to rotate the upper rotary body while the boom hydraulic actuator moves the boom upward.

2. A control apparatus for a work machine comprising:

a hydraulic pump which is driven by an engine;

a hydraulic actuator to which pressurized oil is supplied, the pressurized oil being discharged from the hydraulic pump;

a generator motor which is coupled to an output shaft of the engine;

a storage device which accumulates electric power generated by the generator motor and supplies electric power to the generator motor;

an electric actuator which is driven by the electric power generated by the generator motor and/or the electric power accumulated in the storage device; and

a control unit for restricting load of the hydraulic pump such that the load of the hydraulic pump is decreased as power of the electric actuator is increased.

3. A control apparatus for a work machine comprising:

a hydraulic pump which is driven by an engine;

a hydraulic actuator to which pressurized oil is supplied, the pressurized oil being discharged from the hydraulic pump;

a generator motor which is coupled to an output shaft of the engine;

a storage device which accumulates electric power generated by the generator motor and supplies electric power to the generator motor;

an electric actuator which is driven by the electric power generated by the generator motor and/or the electric power accumulated in the storage device;

a determination unit which determines whether or not the hydraulic actuator and the electric actuator are concurrently actuated;

a first control unit which restricts a torque or a speed of the electric actuator when the determination unit determines that the hydraulic actuator and the electric actuator are concurrently actuated; and

a second control unit for restricting load of the hydraulic pump such that the load of the hydraulic pump is decreased as power of the electric actuator is increased.