HYBRID CONSTRUCTION MACHINE

• US 20070214782A1
• Filed: 02/21/2007
• Published: 09/20/2007
• Est. Priority Date: 03/15/2006
• Status: Active Grant

• Current Assignee: Kobelco Construction Machinery Company Limited (Kobe Steel Limited)
• Original Assignee: Kobelco Construction Machinery Company Limited (Kobe Steel Limited)
• Inventors: KAGOSHIMA, Masayuki, KOMIYAMA, Masayuki
• Granted Patent: US 7,669,413 B2
• Time in Patent Office: Days
• US Class Current: 60/431
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2510/083 Torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60Y 2200/25 Track vehicles
• 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

Abstract

In a hybrid excavator, a hydraulic pump and a generator motor are connected in parallel to an output shaft of an engine and a rotation motor is driven by a battery. The generator motor assists the engine by performing a motor function. Power consumption of each of the hydraulic pump and the rotation motor is detected. The output of the hydraulic pump and the rotation motor is controlled such that the sum of the detected power consumption does not exceed maximum supply power set as the sum of power that can be supplied to the hydraulic pump and the rotation motor.

Claims

1. A hybrid construction machine comprising:

an engine;

a hydraulic pump connected to an output shaft of the engine;

a hydraulic actuator driven by the hydraulic pump;

a generator motor connected to the output shaft of the engine to perform a generator function and a motor function;

an electric actuator;

operating means for operating the hydraulic actuator and the electric actuator;

an electric storage device which supplies and receives electric power to and from the generator motor and the electric actuator; and

control means for controlling outputs of the hydraulic pump and the electric actuator,

wherein the control means detects power consumption of each of the hydraulic pump and the electric actuator, and controls the outputs of the hydraulic pump and the electric actuator so that the sum of the detected power consumption does not exceed maximum supply power set as the sum of power that can be supplied to the hydraulic pump and the electric actuator.

2. The hybrid construction machine according to claim 1, wherein the control means detects a charging state of the electric storage device and an engine revolution speed, and sets the maximum supply power on the basis of actual maximum system power that can be obtained from the actual charging state of the electric storage device and the actual engine revolution speed.

3. The hybrid construction machine according to claim 2, wherein the control means selects, as the maximum supply power, the lower of either the actual maximum system power or the maximum power of a hydraulic construction machine of the same type and with similar operating capabilities to those of the hybrid construction machine.

4. The hybrid construction machine according to claim 1, wherein

the electric actuator is a rotation motor;

and

the control means controls the output of the hydraulic pump so as not to exceed a value obtained by subtracting the power consumption of the rotation motor from the maximum supply power.

5. The hybrid construction machine according to claim 1, further comprising:

operation amount detecting means for detecting the amount of operation of the operating means for operating the respective actuators including the electric actuator; and

a plurality of hydraulic actuators,

wherein the control means divides the maximum supply power into power to be supplied to the hydraulic pump and power to be supplied to the electric actuator according to a ratio between the sum of the amounts of operation of the operating means for the respective hydraulic actuators and the amount of operation of the operating means for the electric actuator, and, on the basis of this division, controls the output of each of the hydraulic pump and the electric actuator.

6. The hybrid construction machine according to claim 1, further comprising:

operation amount detecting means for detecting the amount of operation of the operating means for operating the respective actuators including the electric actuator; and

a plurality of hydraulic actuators,

wherein the control means controls the output of each of the hydraulic pump and the electric actuator on the basis of a division ratio preset according to an operation pattern of the operating means.