Quick coupler control device for working machine

Patent metadata

Field	Value
Publication number	US-10113292-B2
Application number	US-201515302799-A
Country	US
Kind code	B2
Filing date	Apr 8, 2015
Priority date	Apr 8, 2014
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

In a control device, a pilot-operated first check valve connects a solenoid-operated first directional control valve to a lock side chamber of a lock cylinder installed in a quick coupler. A pilot-operated second check valve is connected to the lock cylinder unlock side chamber, a solenoid-operated second directional control valve connected between the second check valve and the first directional control valve. The first and second directional control valves are controlled by a controller with processed signals input from a mode selector switch, first sensor detecting a buck closing pilot pressure, and second sensor detecting a bucket closing working pressure.

First claim

The invention claimed is:

1. A quick coupler control device for a working machine comprising:
a quick coupler that allows a work tool to be removably installed on a working arm of the working machine;
a lock cylinder attached to the quick coupler and having a lock-side chamber that is pressurized when the work tool installed on the quick coupler is actuated in a lock direction in which the work tool is fixed and an unlock-side chamber that is pressurized when the work tool is actuated in an unlock direction in which the work tool is unfixed;
a solenoid-operated first direction control valve having an unexcited position where a working fluid fed under pressure from a fluid pressure source is guided to a lock-side chamber of the lock cylinder and an excited position where the working fluid fed under pressure from the fluid pressure source is guided to an unlock-side chamber of the lock cylinder and where a return fluid discharged from the lock-side chamber is discharged to a low pressure side of the fluid pressure source;
a pilot-operated first check valve that sets a forward direction, in which a working fluid is fed under pressure from the first direction control valve to the lock-side chamber of the lock cylinder, a check function of the pilot-operated first check valve being cancelled by a working fluid fed under pressure to the unlock-side chamber of the lock cylinder;
a pilot-operated second check valve that sets a forward direction, in which a working fluid is fed under pressure to the unlock-side chamber of the lock cylinder, a check function of the pilot-operated second check valve being cancelled by a working fluid fed under pressure to the lock-side chamber of the lock cylinder;
a solenoid-operated second direction control valve having an unexcited position where a return fluid flowing out from the unlock-side chamber of the lock cylinder via the second check valve is discharged to the low pressure side of the fluid pressure source and where a working fluid fed via the first direction control valve is blocked and an excited position where a working fluid fed via the first direction control valve is guided to the unlock-side chamber of the lock cylinder;
a tool cylinder that pivots the work tool that is removably installed on the working arm of the working machine via the quick coupler;
a mode selector switch that switches between a lock mode where the lock cylinder is actuated in the lock direction and an unlock mode where the lock cylinder is actuated in the unlock direction;
a first sensor that detects whether a state of operation where the tool cylinder is actuated in a predetermined direction is established or whether a state of no operation where the tool cylinder is not actuated in the predetermined direction is established;
a second sensor that detects whether a loaded state where load is applied to the tool cylinder is established and a unloaded state where load is not applied to the tool cylinder is established; and
a controller having a function to control the first direction control valve and the second direction control valve to the unexcited position when the mode selector switch is in the lock mode and to control the first direction control valve and the second direction control valve to the excited position when the mode selector switch is in the unlock mode and the first sensor and the second sensor detect the operation state and the loaded state, respectively, and otherwise to control the first direction control valve and the second direction control valve to the excited position and the unexcited position, respectively.

2. The quick coupler control device for a working machine according to claim 1 , wherein
the tool cylinder is a bucket cylinder that pivots a bucket serving as a work tool removably installed by means of the quick coupler on an arm of an excavator serving as a working machine,
the first sensor is provided in a pilot pressure circuit that operates a bucket cylinder control valve in a bucket close direction, the bucket cylinder control valve controlling the bucket cylinder,
the second sensor is provided in a working fluid pressure circuit that actuates the bucket cylinder in the bucket close direction, and
the controller has a function to control the first direction control valve and the second direction control valve to the excited position when the mode selector switch is in the unlock mode and the first sensor and the second sensor detect the operation state in the bucket close direction and the loaded state in the bucket close direction, respectively, and otherwise to control the first direction control valve and the second direction control valve to the excited position and the unexcited position, respectively.

3. A working machine comprising:
a working arm, and
the quick coupler control device of claim 1 .

Assignees

• Caterpillar Sarl

Inventors

• Yokota Kenichi
• Abe Shigeru
• Kanenawa Yuya
• Yukimura Yujiro

Classifications

• E02F9/226

  Safety arrangements, e.g. hydraulic driven fans, preventing cavitation, leakage, overheating · CPC title

• E02F3/32

  working downwardly and towards the machine, e.g. with backhoes · CPC title

• E02F3/3618

  with two separating hooks · CPC title

• E02F3/3622

  with a hook and a locking element acting on a pin · CPC title

• E02F3/3663 Primary

  hydraulically-operated · CPC title