Hydraulic drive device of civil engineering/construction machine

Abstract

Abstract PURPOSE:To reduce the manufacturing cost by individually controlling the magnitude of a control pressure, which is given to No.1 pilot valve from a decompressing means, and the magnitude of a control pressure given to No.2 pilot valve from decompressing means. CONSTITUTION:When a control lever 2 is turned in the S1 direction, an electric signal is read into the operational part of a controller 3 via a signal wire 6a. The operational part gives signal to solenoid selector valves 5i, 5o and emits control current to solenoid proportioning decompression valves 4i, 4o via signal lines 7i, 7o so as to generate respective control pressures. The control pressure led through a meter-in pilot line 15i is given to No.1 pilot valve 9aip of No.1 flow control valve 9ai so as to displace No.1 main seat valve 9aiS. The control pressure led through a meter-out pilot line 150 is given to No.2 pilot valve 9aop so as to displace No.2 main seat valve 9aos.

Inventors

• 👤 Hideyo Kato
• 👤 英世 加藤
• 👤 Masami Ochiai
• 👤 落合　正己

Bibliographic Details