| 摘要 |
<p>A pressure regulating valve (20) for adjusting a pressure of a supply/discharge passage (10) to a pressure balanced against a weight of a body to be carried (1) is provided. The supply/discharge passage (10) is connected to a working chamber (8) of a cylinder (2) for raising and lowering the body to be carried (1). A control valve (38) for increasing and decreasing a pressure in a control passage (28) in accordance with a balance between the weight of the body to be carried (1) and a working force in a reaction force chamber (42) to which a pilot pressure is introduced from the control passage (28) is also provided. The pressure regulating valve (20) comprises a pressure regulating chamber (26) connected to the control passage (28) via an opening/closing valve (48), a pilot chamber (30) to which the pilot pressure from the control passage (28) is constantly introduced, and a control chamber (32) to which a pilot pressure from the supply/discharge passage (10), and it adjusts the pressure of the supply/discharge passage (10) to the pressure balanced against the weight of the body to be carried (1) by balancing a working force in the pressure regulating chamber (26) with working forces in the pilot chamber (30) and the control chamber (32). <IMAGE></p> |
