Quick coupler circuit for construction equipment

Abstract

A switch ( 15 ) is configured so as to be operated with two positions of a locked position when an attachment is held and an unlocked position when an attachment is released. Furthermore, a control device ( 16 ) receives an operation signal that is output when the switch ( 15 ) is operated to the locked position or the unlocked position and switches and controls an electromagnetic switching valve ( 13 ) so that the pressure of a hydraulic pump begins to rise and so that, at a stage when a predetermined time has passed, the pressure raising in the hydraulic pump is stopped.

1 . A quick coupler circuit for construction equipments for attaching or detaching an attachment to or from a working machine, the quick coupler circuit comprising:
 a quick coupler cylinder that is subject to extension and retraction driving and holds/detaches the attachment to or from the working machine;   a hydraulic pump;   an electromagnetic switching valve that switches forced pressure raising of the hydraulic pump;   a coupler switching valve for performing extension and retraction driving of the quick coupler cylinder by switching a supplying direction of hydraulic oil to the quick coupler cylinder; and   a control device that switches and controls the electromagnetic switching valve and the coupler switching valve, respectively,   wherein a switch for switching and operating the electromagnetic switching valve and the coupler switching valve is configured so as to be operated with two positions of a locked position where extending and retracting the quick coupler cylinder to hold the attachment, and an unlocked position where extending and retracting the quick coupler cylinder to detach the attachment, and   the control device switches and controls the coupler switching valve by receiving an operation signal that is output by operating the switch to the locked position or the unlocked position, and switches and controls the electromagnetic switching valve so that the pressure raising of the hydraulic pump begins by operation of the switch and the pressure raising of the hydraulic pump is stopped at a stage when a predetermined time elapses.