Control system for operating work device for construction machine

Abstract

Disclosed is a control system for controlling flow so as to allow simultaneous usage of a parallel flow path and a tandem flow path thereby reducing loss of pressure inside a control valve, when simultaneously operating work devices having different operating pressures. A control system for operating the work device, according to the present invention, provides the control system for operating the work device for a construction machine, comprising: first and second hydraulic pumps that are connected to an engine; a revolution control valve, an arm control valve, and a left driving control valve, which are installed on a first center bypass path of the first hydraulic pump, and each of which is connected via the parallel flow path; a boom control valve, a bucket control valve, and a right driving valve, which are installed on a second center bypass path of the second hydraulic pump, and each of which is connected via the parallel flow path; a pressure generation device; a bleed flow path, which is formed on a control spool at a lower side of a boom of the boom control valve, for maintaining an open state of the second center bypass path without closing same, when the boom control valve is switched so as to lower the boom; and a center bypass switch valve, which is installed on the lowermost side of the second center bypass path and is switched by means of a control signal for switching the boom control valve.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an attachment driving control system for a construction machine. More particularly, the present invention relates to an attachment driving control system for a construction machine, in which in the case where two attachments having different operating pressures are simultaneously driven (e.g., the case where a boom for performing a boom descending operation and an attachment such as a bucket are simultaneously driven), a flow rate of a hydraulic fluid is controlled to enable the simultaneous use of a parallel flow path and a tandem flow path, leading to a reduction in a pressure loss occurring in the control valve.BACKGROUND OF THE INVENTION[0002]In general, a conventional boom driving control system for a construction machine in accordance with the prior art as shown in FIG. 1 includes:[0003]an engine 1;[0004]first and second variable displacement hydraulic pumps (hereinafter, referred to as “first and second hydraulic pu...

AI Technical Summary

Benefits of technology

The present invention provides an attachment driving control system for a construction machine. The system allows for the simultaneous use of attachments that require different operating pressures. This is done by using a hydraulic fluid from a second pump to flow into the control valve of the bucket, reducing pressure loss and energy loss. This results in an improved efficiency of the attachment driving control system.

Problems solved by technology

Meanwhile, in the case where two different attachments such as the boom for performing a boom descending operation and the bucket are driven simultaneously, the second center bypass path 12 is blocked by the control spool on a boom descending side and the hydraulic fluid is supplied to the bucket cylinder 15 through only the parallel flow path 12a. In this case, there occurs a problem in that a sufficient flow path cannot be secured by a priority control valve installed in the parallel flow path 12a, thereby inducing an excessive pressure loss, and thus causing an energy loss.

In addition, a variable control valve as a throttle valve 24 (see FIG. 2) may be installed in the parallel flow path 12a, but there is a limitation in securing the flow path using the throttle device.

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