Control system for construction machine

• US 9,835,187 B2
• Filed: 07/23/2013
• Issued: 12/05/2017
• Est. Priority Date: 07/25/2012
• Status: Expired due to Fees

• Current Assignee: KYB Corp.
• Original Assignee: KYB Corp.
• Inventors: Egawa, Masahiro, Kawasaki, Haruhiko, Yonehara, Yasuhiro
• Primary Examiner(s): Lopez, F. Daniel
• Application Number:
  US14/406,535
• Publication Number:
  US 20150152900A1
• Time in Patent Office: 1,596 Days
• 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 9/2217 with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: E02F 9/2285 Pilot-operated systems
• CPC Class Codes: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump
• CPC Class Codes: F15B 21/14 Energy-recuperation means
• CPC Class Codes: F15B 2211/20507 Type of prime mover
• CPC Class Codes: F15B 2211/40515 with variable throttles or orifices
• CPC Class Codes: F15B 2211/411 the positions being discrete
• CPC Class Codes: F15B 2211/41527 being connected to an output member and a directional control valve
• CPC Class Codes: F15B 2211/41581 being connected to an output member and a return line
• CPC Class Codes: F15B 2211/46 Control of flow in the return line, i.e. meter-out control
• CPC Class Codes: F15B 2211/7053 Double-acting output members
• CPC Class Codes: F15B 2211/7058 Rotary output members
• CPC Class Codes: F15B 2211/761 Control of a negative load, i.e. of a load generating hydraulic energy

Abstract

A control system for a construction machine includes: a boom cylinder; a boom switching valve; a fluid pressure motor adapted to drive a motor generator by being rotated by means of a return fluid guided from a piston side chamber; a regeneration control valve adapted to adjust a first supply amount serving as a supply amount of a working fluid supplied from the piston side chamber to the boom switching valve, and a second supply amount serving as a supply amount of the working fluid supplied from the piston side chamber to the fluid pressure motor; and a controller adapted to control the regeneration control valve so that the second supply amount becomes smaller than the first supply amount in a case where a stroke amount of a spool becomes an upper limit value or more.

Claims

1. A control system for a construction machine, comprising:

a boom cylinder partitioned into a piston side chamber and a rod side chamber by a piston, the boom cylinder operating so as to be extended and contracted by supplying a working fluid to the piston side chamber or the rod side chamber, thereby driving a boom;

a boom switching valve adapted to adjust a supply amount of the working fluid to be supplied to the piston side chamber or the rod side chamber by means of a stroke of a spool;

a fluid pressure motor adapted to drive a motor generator by being rotated by means of a return fluid guided from the piston side chamber;

a regeneration control valve adapted to communicate the piston side chamber with the boom switching valve and the fluid pressure motor, the regeneration control valve being adapted to adjust a first supply amount and a second supply amount, the first supply amount serving as a supply amount of the working fluid supplied from the piston side chamber to the boom switching valve, the second supply amount serving as a supply amount of the working fluid supplied from the piston side chamber to the fluid pressure motor; and

a controller adapted to control the regeneration control valve so that the second supply amount becomes smaller than the first supply amount in response to a determination that a stroke amount of the spool becomes an upper limit value or more.

3. The control system for the construction machine according to claim 1, wherein the regeneration control valve includes:

a pilot chamber connected to a pilot pressure source via a proportional solenoid valve; and

a spring provided on the opposite side of the pilot chamber, the spring being adapted to exert spring force for pressing the spool toward the side of the pilot chamber, and

wherein the controller controls the opening degree of the regeneration control valve by controlling the proportional solenoid valve to apply pilot pressure to the pilot chamber.

4. The control system for the construction machine according to claim 1, wherein

the upper limit value is set up on the basis of rated power of the motor generator.

2. A control system for a construction machine, comprising:

a boom cylinder in which a piston side chamber and a rod side chamber are formed by a piston, the boom cylinder operating so as to be extended and contracted by supplying a working fluid to the piston side chamber or the rod side chamber, thereby driving a boom;

a boom switching valve adapted to adjust a supply amount of the working fluid to be supplied to the piston side chamber or the rod side chamber by means of a stroke of a spool;

a fluid pressure motor adapted to drive a motor generator by being rotated by means of a return fluid guided from the piston side chamber;

a regeneration control valve adapted to communicate the piston side chamber with the boom switching valve and the fluid pressure motor, the regeneration control valve being adapted to adjust a supply amount of the working fluid supplied from the piston side chamber to the boom switching valve and a supply amount of the working fluid supplied from the piston side chamber to the fluid pressure motor;

a bleed-off valve provided on a passage connecting the regeneration control valve to the fluid pressure motor, the bleed-off valve communicating or blocking between the piston side chamber and a tank at a drain side; and

a controller adapted to, in a case where a stroke amount of the spool becomes an upper limit value or more, control an opening degree of the bleed-off valve in accordance with the stroke amount to communicate the piston side chamber with the tank.