HYBRID WORKING MACHINE AND CONTROLLING METHOD THEREOF

• US 20120109472A1
• Filed: 06/25/2009
• Published: 05/03/2012
• Est. Priority Date: 06/25/2009
• Status: Active Grant

• Current Assignee: Sumitomo Heavy Industries Limited, Sumitomo (S.H.I.) Construction Machinery Co., Ltd. (Sumitomo Heavy Industries Limited)
• Original Assignee: Sumitomo Heavy Industries Limited, Sumitomo (S.H.I.) Construction Machinery Co., Ltd. (Sumitomo Heavy Industries Limited)
• Inventors: Yanagisawa, Makoto
• Granted Patent: US 8,798,876 B2
• Time in Patent Office: Days
• US Class Current: 701/50
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/06 Limiting the traction current under mechanical overload conditions
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/0677 Engine power
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: B60Y 2200/25 Track vehicles
• CPC Class Codes: B60Y 2200/412 Excavators
• 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: F02D 29/02 : peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

In a hybrid working machine, a control unit (60) corrects an output upper limit value of an engine (50) based on a deviation between a target revolution speed of the engine and an actual revolution speed of the engine, and output values of a motor generator (12), a hydraulically driven unit (54) and an electrically driven unit (56) are determined based on the corrected output upper limit value of the engine, or the control unit (60) corrects an output lower limit value of the motor generator (12) based on a deviation between the target revolution speed of the engine and the actual revolution speed of the engine, and the output values of the motor generator (12), the hydraulically driven unit (54) and the electrically driven unit (56) are determined based on the corrected output lower limit value of the motor generator (12).

Claims

1. A hybrid working machine comprising:

a hydraulic generator configured to convert an output from an engine to a hydraulic pressure and supply to a hydraulically driven unit;

a motor generator connected to the engine and configured to function as both of an electric motor and a generator;

an electric power accumulator configured to supply an electric power to the motor generator to cause the motor generator to function as the electric motor;

an electrically driven unit configured to be driven by the electric power from the electric power accumulator, generate a regenerated electric power and supply the regenerated electric power to the electric power accumulator; and

a control unit configured to control an operation of the motor generator,

wherein the control unit corrects an output upper limit value of the engine based on a deviation between a target revolution speed of the engine and an actual revolution speed of the engine and determines output values of the motor generator, the hydraulically driven unit and the electrically driven unit based on the corrected output upper limit value of the engine.

2. The hybrid working machine according to claim 1,

wherein the control unit corrects an output lower limit value of the motor generator based on a deviation between the target revolution speed of the engine and the actual revolution speed of the engine, and determines output values of the motor generator, the hydraulically driven unit and the electrically driven wilt based on the corrected output lower limit value of the engine.

3. The hybrid working machine according to claim 2,

wherein the control unit corrects the output lower limit value of the motor generator in consideration of discharge capability of the electric power accumulator.

4. The hybrid working machine according to claim 1,

wherein control unit determines an output from the hydraulically driven unit based on discharge capability of the electric power accumulator.

5. A hybrid working machine comprising:

a hydraulic generator configured to convert an output from an engine to a hydraulic pressure and supply to a hydraulically driven unit;

a motor generator connected to the engine and configured to function as both of an electric motor and a generator;

an electric power accumulator configured to supply an electric power to the motor generator to cause the motor generator to function as the electric motor;

an electrically driven unit configured to be driven by the electric power from the electric power accumulator, generate a regenerated electric power and supply the regenerated electric power to the electric power accumulator; and

a control unit configured to control an operation of the motor generator,

wherein the control unit corrects an output lower limit value of the motor generator based on a deviation between a target revolution speed of the engine and an actual revolution speed of the engine and determines output values of the motor generator, the hydraulically driven unit and the electrically driven unit based on the corrected output lower limit value of the motor generator.

6. The hybrid working machine according to claim 5,

wherein the control unit corrects the output lower limit value of the motor generator in consideration of discharge capability of the electric power accumulator.

7. The hybrid working machine according to claim 5,

wherein control unit determines an output from the hydraulically driven unit based on discharge capability of the electric power accumulator.

8. A control method of a working machine which is operated by driving a hydraulic generator with an engine, the control method comprising:

setting an increasing rate of an output from the engine to be a predetermined value;

comparing an upper limit value of the engine which is obtained from the predetermined value and a required power which is obtained from a hydraulic output required for the hydraulic generator; and

controlling an output from the engine to be the output upper limit value or less when the required power exceeds the output upper limit value.

9. The control method according to claim 8,

wherein when the required power exceeds the output upper limit value, a power exceeding the output upper limit value is supplied by the electric motor.

10. The control method according to claim 9,

wherein the electric motor is driven by a power obtained from the electric power accumulator and a regenerated electric power obtained from a working motor generator.

11. The control method according to claim 8,

wherein the output from the engine is controlled by a predetermined time interval, and the output upper limit value of the engine is obtained by adding a value of a predetermined rate to a previous output from the engine.

12. The control method according to claim 11,

wherein when the output upper limit value of the engine is obtained, a revolution speed of the engine is considered.