| 摘要 |
The invention relates to a hydraulic circuit for a ram cylinder and an object thereof is to cause double or more supply/discharge circuits for the ram cylinder to serve a plurality of functions. The invention includes: a ram cylinder which drives a driven device; a control valve hydraulic unit including (i) a supply circuit which includes a supply control valve for controlling hydraulic oil from a hydraulic power supplier and a supply throttle valve for controlling an amount of supplied oil, and (ii) a discharge circuit which includes a discharge control valve for controlling hydraulic oil returning from the ram cylinder and a discharge throttle valve for controlling an amount of the returning hydraulic oil; and a first supply/discharge circuit which connects the ram cylinder with the supply circuit of the hydraulic unit, and a second supply/discharge circuit which connects the ram cylinder with the discharge circuit of the hydraulic unit. A bypass circuit having an opening/closing function connects a portion downstream from the supply control valve and the supply throttle valve with a portion downstream from the discharge control valve and the discharge throttle valve, and the bypass circuit allows the first and second supply/discharge circuits to serve a plurality of functions. |
