Construction machine with floating function

Abstract

Disclosed is a construction machine with a floating function for performing soil preparation or the like for flattening the ground or the like using a dozer blade. The construction machine with a floating function according to the present invention comprises: a hydraulic pump and a pilot pump; a dozer cylinder connected to the hydraulic pump so as to move the dozer blade in the vertical direction; a control valve arranged in a channel between the hydraulic pump and the dozer cylinder; a dozer check valve arranged in the channel between the control valve and the dozer cylinder; a return check valve arranged in the channel between the control valve and a hydraulic tank; a solenoid valve for floating arranged in a signal path between the pilot pump and the dozer check valve such that the solenoid valve is capable of opening and closing; a channel for floating, one end of which is connected to the hydraulic tank and the other end of which is connected to the channel interconnecting the control valve and the dozer cylinder; and a check valve arranged in the channel for floating so as to supply working fluid to the dozer cylinder through the channel for floating from the hydraulic tank in a floating mode, and cut off the channel for floating when the floating mode is cancelled.

Description

TECHNICAL FIELD[0001]The present invention relates to a construction machine having a floating function. More particularly, the present invention relates to such a construction machine having a floating function, which can perform a ground leveling work or a grading work in which the ground is flattened and leveled using a dozer blade.BACKGROUND OF THE INVENTION[0002]The floating function means a function in which a dozer blade is moved upwardly and downwardly along a rugged ground surface by its own weight or an external force even without a manipulation of a manipulation lever by an operator during the traveling of the construction machine. Even when the construction machine is simply manipulated to be traveled by the floating function, a ground leveling work or a grading work can be performed in which the ground is flattened and leveled by the dozer blade moved upwardly and downwardly.[0003]As shown in FIG. 1, a construction machine having a floating function in accordance with t...

AI Technical Summary

Benefits of technology

The invention provides a construction machine with a floating function that improves workability by increasing the vertical movement speed of the dozer blade when performing ground leveling or grading work.

Problems solved by technology

Thus, the supply and discharge of the hydraulic fluid to and from the dozer cylinder 4 is not performed smoothly in the floating mode, thus leading to a decrease in the vertical movement speed of the dozer cylinder 4.

In addition, in the process in which the dozer blade is moved upwardly or ascends in the floating mode, if a back pressure is formed in the flow path along which the hydraulic fluid discharged from the dozer cylinder 4 is returned, the dozer blade cannot ascend easily along the rugged ground surface.

For this reason, the conventional construction machine having a floating function entails a problem in that because the vertical movement speed of the dozer blade is relatively decreased as compared the traveling speed of the construction machine, the dozer blade does not ascend or descend smoothly along the rugged ground surface, resulting in a deterioration of workability in the ground leveling work.

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