Control device for hybrid construction machine

• US 8,321,095 B2
• Filed: 04/20/2009
• Issued: 11/27/2012
• Est. Priority Date: 04/25/2008
• Status: Expired due to Fees

• Current Assignee: KYB Corp.
• Original Assignee: Kayaba Industry Company Limited (KYB Corp.)
• Inventors: Egawa, Masahiro, Kawasaki, Haruhiko
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): Rink, Ryan
• Application Number:
  US12/988,651
• Publication Number:
  US 20110035102A1
• Time in Patent Office: 1,317 Days
• Field of Search: 701/50, 701/36
• US Class Current: 701/50
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: E02F 9/2228 including an electronic controller
• CPC Class Codes: E02F 9/2235 including an electronic controller
• 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 2211/20515 Electric motor
• CPC Class Codes: F15B 2211/20523 Internal combustion engine
• CPC Class Codes: F15B 2211/20546 variable capacity
• CPC Class Codes: F15B 2211/265 Control of multiple pressure sources
• CPC Class Codes: F15B 2211/3116 the pump port being open in the centre position, e.g. so-called open centre
• CPC Class Codes: F15B 2211/88 Control measures for saving energy

Abstract

The amount of assist for a sub-pump (SP) is reduced when a rotating motor (RM) is singly operated, and the amount of assist for the sub-pump (SP) is increased except when the rotating motor (RM) is singly operated. A controller (C) has a function which, when a signal representing single operation of a rotating motor is inputted in the controller from a single operation detecting means and, at the same time, when a single indicating that assist is required is inputted from an assist controlling input means (A1) in the controller, controls either or both of the speed of an electric motor (MG) and the tilt angle of the sub-pump (SP) based on a low-output set value lower than a value for normal operation of the rotating motor, which is operation other than when the rotating motor is singly operated.

Claims

1. A control device for a hybrid construction machine, including

a variable displacement type of a main pump,

a circuit system connected to the main pump and including a plurality of operated valves for controlling actuators, and

an operated valve for controlling a rotating motor provided in the circuit system, comprising:

a single operation detection unit that detects single operation of the rotating motor and outputs a signal representing a rotating motor single operation to the controller;

a variable displacement sub-pump;

a tilt angle control unit that controls a tilt angle of the sub-pump;

an electric motor that is a driving source of the sub-pump;

a merging passage connected to the sub-pump and communicating with a discharge side of the main pump;

an assist control input unit that inputs a signal representing whether or not assist control is required in the single operation of the rotating motor; and

a controller that controls the tilt angle of the sub-pump and a rotational speed of the electric motor, wherein

the controller comprises a function of controlling one of or both a rotational speed of the electric motor and a tilt angle of the sub-pump on the basis of a low output setting of the assist force which is lower than a low output set value in regular working operations, when the controller receives the signal representing a rotating-motor single operation from the single operation detection unit and receives the signal representing a need for an assist from the assist control input unit.

2. The control device for a hybrid construction machine according to claim 1,

wherein the controller controls the output of the sub-pump on the basis of a high output setting of the assist force in regular working operations, and a low output setting of the assist force when controlling the single operation of the rotating motor and an assist is required.

3. The control device for a hybrid construction machine according to claim 1, wherein the controller comprises a function of setting output of the sub-pump to zero when an assist is not required in the single operation of the rotating motor.

4. The control device for a hybrid construction machine according to claim 2, wherein the controller comprises a function of setting output of the sub-pump to zero when an assist is not required in the single operation of the rotating motor.