HYBRID CONSTRUCTION MACHINE

• US 20150354603A1
• Filed: 06/03/2015
• Published: 12/10/2015
• Est. Priority Date: 06/05/2014
• Status: Active Grant

• Current Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Inventors: NISHIKAWA, Shinji, ISHIKAWA, Kouji, SATAKE, Hidetoshi, IMURA, Shinya, IZUMI, Shiho
• Granted Patent: US 10,006,473 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E02F 9/123 Drives or control devices specially adapted therefor E02F9/125 and E02F9/128 take precedence
• CPC Class Codes: E02F 9/2095 Control of electric, electro-mechanical or mechanical equipment not otherwise provided for, e.g. ventilators, electro-driven fans control of hydraulic driven equipment E02F9/22
• CPC Class Codes: E02F 9/2203 Arrangements for controlling the attitude of actuators, e.g. speed, floating function
• CPC Class Codes: E02F 9/2228 including an electronic controller
• CPC Class Codes: E02F 9/2282 Systems using center bypass type changeover valves
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump
• CPC Class Codes: F15B 11/042 by means in the feed line , i.e. "meter in"F15B11/046, F15B11/05 take precedence
• CPC Class Codes: F15B 11/08 with only one servomotor
• CPC Class Codes: F15B 2211/20515 Electric motor
• CPC Class Codes: F15B 2211/30525 Directional control valves, e.g. 4/3-directional control valve
• CPC Class Codes: F15B 2211/3059 having multiple valves for multiple output members
• CPC Class Codes: F15B 2211/6306 representing a pressure
• CPC Class Codes: F15B 2211/6346 representing a state of input means, e.g. joystick position
• CPC Class Codes: F15B 2211/6355 having valve means
• CPC Class Codes: F15B 2211/6654 Flow rate control
• CPC Class Codes: F15B 2211/7058 Rotary output members
• CPC Class Codes: F15B 2211/7135 Combinations of output members of different types, e.g. single-acting cylinders with rotary motors
• CPC Class Codes: F15B 2211/75 Control of speed of the output member

Abstract

This invention provides a hybrid construction machine including a swing structure, a hydraulic pump, a hydraulic swing motor driving the swing structure using hydraulic fluid from the hydraulic pump, an electric swing motor driving the swing structure in conjunction with the hydraulic swing motor, a boom cylinder operated simultaneously with the swing structure at times and driven by the hydraulic fluid from the hydraulic pump, a first directional control valve controlling flow of the hydraulic fluid supplied from the hydraulic pump to the hydraulic swing motor, a second directional control valve controlling the flow of the hydraulic fluid returning from the hydraulic swing motor, and a controller and solenoid pressure reducing valves which prevent operation of the second directional control valve when the boom cylinder is operated simultaneously with the swing structure.

Claims

1. A hybrid construction machine comprising:

a swing structure;

a hydraulic pump;

a hydraulic swing motor driving the swing structure using hydraulic fluid from the hydraulic pump;

an electric swing motor driving the swing structure in conjunction with the hydraulic swing motor;

a hydraulic actuator operated simultaneously with the swing structure at times and driven by the hydraulic fluid from the hydraulic pump;

a directional control valve for meter-in control controlling flow of the hydraulic fluid supplied from the hydraulic pump to the hydraulic swing motor;

a directional control valve for meter-out control controlling the flow of the hydraulic fluid returning from the hydraulic swing motor; and

a regulating device regulating operation of the directional control valve for meter-in control;

wherein, when the hydraulic actuator is operated simultaneously with the swing structure, the regulating device prevents the operation of the directional control valve for meter-in control to cause the swing structure to be driven by the electric swing motor alone.

2. The hybrid construction machine according to claim 1,

wherein the directional control valve for meter-in control is disposed on a center bypass hydraulic line constituting part of the hydraulic line for connecting the hydraulic pump to a tank, and has a function of controlling the flow rate of the hydraulic fluid returning from the hydraulic pump to the tank;

and

wherein the directional control valve for meter-out control is disposed on a hydraulic line other than the center bypass hydraulic line.

3. The hybrid construction machine according to claim 1,

wherein the directional control valve for meter-in control is disposed on a center bypass hydraulic line constituting part of the hydraulic line for connecting the hydraulic pump to a tank, and has a function of controlling the flow rate of the hydraulic fluid returning from the hydraulic pump to the tank;

and

wherein the directional control valve for meter-out control is disposed on the center bypass hydraulic line, and does not have the function of controlling the flow rate of the hydraulic fluid returning from the hydraulic pump to the tank.

4. The hybrid construction machine according to claim 1,

wherein the directional control valve for meter-in control and the directional control valve for meter-out control are switched by the same operating pilot pressure;

and

wherein the regulating device has a valve mechanism for blocking the operating pilot pressure led to the directional control valve for meter-in control when the hydraulic actuator is operated simultaneously with the swing structure.