HYDRAULIC SHOVEL AND METHOD OF CONTROLLING HYDRAULIC SHOVEL

• US 20120246981A1
• Filed: 03/29/2012
• Published: 10/04/2012
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Sumitomo (S.H.I.) Construction Machinery Co., Ltd. (Sumitomo Heavy Industries Limited)
• Original Assignee: Sumitomo (S.H.I.) Construction Machinery Co., Ltd. (Sumitomo Heavy Industries Limited)
• Inventors: MAGAKI, Hideto, SHIRATANI, Ryuji, TAKEO, Jitsutaka
• Granted Patent: US 9,593,466 B2
• Time in Patent Office: Days
• US Class Current: 37/443
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• CPC Class Codes: E02F 9/2285 Pilot-operated systems

Abstract

A hydraulic shovel includes an engine; a hydraulic pump driven by the engine; an excavating attachment which is driven by high oil discharged from the hydraulic pump; a motor generator that assists a power supply of the engine; and an assist control unit that controls the motor generator to assist the engine in a latter part of the excavating operation by the excavating attachment.

Claims

1. A hydraulic shovel comprising:

an engine;

a hydraulic pump driven by the engine;

an excavating attachment which is driven by oil discharged from the hydraulic pump;

a motor generator that assists a power supply of the engine; and

an assist control unit that controls the motor generator to assist the engine in a latter part of an excavating operation of the excavating attachment.

2. The hydraulic shovel according to claim 1, further comprising:

a regulator that controls discharging of the hydraulic pump,

wherein the assist control unit controls the regulator to increase the power of the hydraulic pump in the latter part of the excavating operation.

3. The hydraulic shovel according to claim 1, further comprising:

a load pressure sensor that detects a load applied to the excavating attachment,

wherein the assist control unit controls the motor generator to assist the engine in the latter part of the excavating operation of the excavating attachment when a pressure detected by the load pressure sensor exceeds a predetermined pressure.

4. The hydraulic shovel according to claim 3,

wherein the load pressure sensor detects a discharge pressure of the hydraulic pump.

5. The hydraulic shovel according to claim 3,

wherein the excavating attachment includes an arm, and the load pressure sensor detects a cylinder pressure of the arm.

6. The hydraulic shovel according to claim 1, further comprising:

an operation status detection unit that detects a timing from which the latter part of the excavating operation is about to start based on an operation status of the excavating attachment,

wherein the assist control unit controls the motor generator to assist the engine when the operation status detection unit detects that the latter part of the excavating operation is about to start.

7. The hydraulic shovel according to claim 6,

wherein the excavating attachment includes an arm,

the hydraulic shovel further comprises an arm operation status detection unit that detects the opening and closing status of the arm, and

wherein the operation status detection unit detects the timing from which the latter part of the excavating operation is about to start based on a value detected by the arm operation status detection unit.

8. The hydraulic shovel according to claim 7,

wherein the arm operation status detection unit detects an opening angle of the arm, and the operation status detection unit detects the timing from which the latter part of the excavating operation is about to start when the value detected by the arm operation status detection unit is less than a predetermined threshold value.

9. The hydraulic shovel according to claim 7, further comprising:

a pilot pressure sensor that detects an operation of an operation device that operates the excavating attachment as a pressure value, and

wherein the operation status detection unit detects the timing from which the latter part of the excavating operation is about to start based on the value detected by the arm operation status detection unit and a value detected by the pilot pressure sensor.

10. The hydraulic shovel according to claim 1,

wherein the excavating attachment includes an arm, and

the motor generator assists a closing operation of the arm in the latter part of the excavating operation by the excavating attachment.

11. The hydraulic shovel according to claim 1,

wherein the excavating attachment includes a bucket, and

the motor generator assists a closing operation of the bucket in the latter part of the excavating operation by the excavating attachment.

12. The hydraulic shovel according to claim 1,

wherein an output required for the excavating attachment exceeds the maximum value capable of being output by the engine in the latter part of the excavating operation by the excavating attachment.

13. A method of controlling a hydraulic shovel including an engine, a hydraulic pump driven by the engine, an excavating attachment which is driven by oil discharged from the hydraulic pump, and a motor generator that assists a power supply of the engine, comprising:

controlling the motor generator to assist the engine in a latter part of an excavating operation of the excavating attachment.

14. The method of controlling the hydraulic shovel according to claim 13,

wherein the hydraulic shovel further includes a regulator that controls discharging of the hydraulic pump, and

the method further comprising:

controlling the regulator to increase the power of the hydraulic pump in the latter part of an excavating operation.

15. The method of controlling the hydraulic shovel according to claim 13,

wherein the hydraulic shovel further includes a load pressure sensor that detects a load applied to the excavating attachment, and

the motor generator is controlled to assist the engine when a pressure detected by the load pressure sensor exceeds a predetermined pressure.

16. The method of controlling the hydraulic shovel according to claim 13, further comprising:

detecting a timing from which the latter part of the excavating operation is about to start based on an operation status of the excavating attachment, and

the motor generator is controlled to assist the engine when the timing from which the latter part of the excavating operation is about to start is detected in the detecting.