Hydraulisches Steuersystem für eine Baumaschine

Details

Veröffentlichungs-Nr.

EP4768739

Anmeldetag

2. September 2024

Veröffentlichung

3. April 2025

Rechtsraum

EP

Abstract

When the control lever is not operated, the discharge pressure of the main pump can be maintained at a pressure above a predetermined minimum pressure. Additionally, when the control lever is operated, it ensures that sufficient flow rate of pressure oil is supplied to the hydraulic actuator of the directional control valve, which is tandem-connected downstream of the bypass cut valve placed in the middle of the center bypass oil passage. Therefore, a bypass cut valve is placed between the first directional control valve and the second directional control valve in the center bypass oil passage. The controller maintains the opening area of the bypass cut valve at a predetermined minimum opening area when all the directional control valves are in the neutral position, and controls the discharge flow rate of the main pump such that the discharge pressure of the main pump is at a pressure equal to or greater than a predetermined minimum discharge pressure. Then, when the second directional control valve, located downstream of the bypass cut-off valve, is operated, the controller controls the increase in the opening area of the bypass cut-off valve as the spool stroke amount of the second directional control valve increases.

Anmelder

Firma

Hitachi Construction Machinery Co., Ltd.

Land

🇯🇵 Japan