| 摘要 |
An air balance system which is easy to operate and can be kept in balance with a body to be conveyed with a simple structure. A pressure regulating valve (50) is provided that regulates a pressure in a supply/exhaust flow path (10) to a pressure countering against the weight of the body (1) to be conveyed. A switching valve (14) is provided that allows the supply/exhaust flow path (10) and a control flow path (18) to communicate with each other when in balance, and the flow path (10) and a pilot flow path (16) to communicate when in a rise/fall drive. A body (1)-suspending cylinder (2) is attached to a lever member (38) supported on a fulcrum pin (44). A restoring force mechanism (48) for imparting an acting force, in the same direction as that of the load of the body (1), to the lever member (38) is provided in the vicinity of the fulcrum pin (44), and an energizing mechanism (74) for imparting to the lever member (38) an acting force in balance with the weight of the body (1) and with the acting force of the restoring force mechanism (48) is provided. The pressure regulating valve (50) supplies/exhausts compressed air to/from the flow path (10) according to an acting force by the rocking of the lever mechanism (38) and an acting force by the introduction of a pilot pressure from the control flow path (18).
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