Hybrid shovel and hybrid shovel control method
First Claim
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1. A hybrid shovel, comprising:
- an engine that is controlled at a constant revolution speed;
a motor generator that assists the engine;
a control part that controls a drive of said motor generator; and
a hydraulic pump that is driven by said engine,wherein said control part causes said motor generator to assist said engine when a revolution speed of said engine is lower than said constant revolution speed due to a load of said hydraulic pump, and said control part causes said motor generator to decrease and stop an assist output to said engine before the revolution speed of said engine returns to said constant revolution speed.
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Abstract
A hybrid shovel includes an engine that is controlled at a constant revolution speed, a motor generator that assists the engine, a control part that controls a drive of the motor generator, and a hydraulic pump that is driven by the engine. The control part causes the motor generator to assist the engine when a revolution speed of the engine is lower than the constant revolution speed due to a load of the hydraulic pump. The control part causes the motor generator to decrease an assist output to said engine before the revolution speed of the engine returns to the constant revolution speed.
5 Citations
8 Claims
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1. A hybrid shovel, comprising:
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an engine that is controlled at a constant revolution speed; a motor generator that assists the engine; a control part that controls a drive of said motor generator; and a hydraulic pump that is driven by said engine, wherein said control part causes said motor generator to assist said engine when a revolution speed of said engine is lower than said constant revolution speed due to a load of said hydraulic pump, and said control part causes said motor generator to decrease and stop an assist output to said engine before the revolution speed of said engine returns to said constant revolution speed. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A hybrid shovel, comprising:
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an engine that is controlled at a constant revolution speed; a motor generator that assists the engine; a control part that controls a drive of said motor generator; and a hydraulic pump that is driven by said engine, wherein said control part causes said motor generator to assist said engine when a revolution speed of said engine is lower than said constant revolution speed due to a load of said hydraulic pump, and said control part causes said motor generator to decrease an assist output to said engine before the revolution speed of said engine returns to said constant revolution speed, wherein said control part sets a target revolution speed of said motor generator to a value lower than a revolution speed corresponding to said constant revolution speed, and said control part maintains the revolution speed of said motor generator at said target revolution speed when the revolution speed of said motor generator reaches said target revolution speed during the assist of said engine by said motor generator.
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Specification