Operation circuit for a work vehicle

• US 7,518,322 B2
• Filed: 11/29/2004
• Issued: 04/14/2009
• Est. Priority Date: 12/04/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Inventors: Kodaka, Katsuaki, Ichimura, Kazuhiro
• Primary Examiner(s): Ro; Bentsu
• Assistant Examiner(s): DINH, THAI T
• Application Number:
  US10/998,046
• Publication Number:
  US 20050122068A1
• Time in Patent Office: 1,597 Days
• Field of Search: 318/34, 180/53.4, 180/53.5, 180/69.6, 180/306
• US Class Current: 318/34
• CPC Class Codes: E02F 9/2025 Particular purposes of control systems not otherwise provided for E02F3/16, E02F3/26, sub-groups of E02F3/43, E02F3/651, sub-groups of E02F3/84, E02F3/907, E02F5/145 take precedence

Abstract

An operation circuit for a work vehicle drives an electromagnetic actuator by generating an operation signal corresponding to a switch operation and drives a work actuator in response to the drive of the electromagnetic actuator. By installing a specific detachable electric circuit unit in a first operation circuit that generates a first operation signal in response to an operation of a specific switch, the first operation circuit can be modified to a second operation circuit that generates a second operation signal different from the first operation signal in response to an operation of the same switch.

Claims

1. An operation circuit for a work vehicle, comprising:

a switch device;

an electromagnetic actuator driven in response to a command signal issued through the switch device;

a work actuator driven by the electromagnetic actuator;

at least one electric circuit module disposed between the switch device and the electromagnetic actuator, which controls driving the electromagnetic actuator in response to a command signal issued through the switch device; and

a connector device that individually and detachably connects the switch device with the electric circuit module and the electric circuit module with the electromagnetic actuator, wherein;

a mode in which the electromagnetic actuator is driven in response to the command signal from the switch device is modified (1) by replacing the electric circuit module with another electric circuit module via the connector device to change the operation circuit and alter the command signal or (2) by attaching another electric circuit module via the connector device to the electric circuit module to change the operation circuit and alter the command signal; and

each electric circuit module includes a relay circuit.

2. An operation circuit for a work vehicle according to claim 1, wherein:

the operation circuit is changed between a first operation circuit and a second operation circuit; and

a drive command for driving the work actuator is output while an operation of the switch device is sustained in the first operation circuit, and a drive command for driving the work actuator is continuously output once an operation of the switch device is performed even if the switch operation of the switch device stops in the second operation circuit.

3. An operation circuit for a work vehicle according to claim 1, wherein:

the operation circuit is changed between a first operation circuit and a second operation circuit;

an operation signal to demand a specific operation of the work actuator in response to an operation of the switch device is output to the electromagnetic actuator in the first operation circuit; and

an operation signal to demand another specific operation of the work actuator along with the specific operation of the work actuator in response to an operation of the switch device is output to the electromagnetic actuator in the second operation circuit.

4. An operation circuit for a work vehicle according to claim 1, further comprising:

a selector switch operated to select driving a single work actuator among a plurality of work actuators, wherein;

the operation circuit is changed between a first operation circuit and a second operation circuit;

a command to demand an operation of the work actuator, determined in advance in response to an operation of the switch device, is output to the electromagnetic actuator in the first operation circuit; and

a command to demand an operation of the work actuator, selected by the selector switch in response to an operation of the switch device, is output to the electromagnetic actuator in the second operation circuit.