What are the safety protection devices of cranes

In order to ensure the safety and reliability of the lifting operation, the crane is equipped with a more complete safety device to protect the machine parts or remind the operator to pay attention to safety protection in the event of an accident.

1. Relief valves in the hydraulic system: it can suppress the abnormal high pressure in the circuit to prevent damage to the hydraulic oil pump and motor, and to prevent overloading.

2. Boom luffing safety device: when an accident occurs and the high-pressure hose or tubing in the boom luffing cylinder circuit bursts or is cut off, the balance valve in the hydraulic circuit will work to lock the work from the lower chamber of the cylinder Oil, so that the boom will not fall, thus ensuring the safety of the operation.

3. Boom telescoping safety device: when accidents occur, the high-pressure hose or tubing in the boom telescoping cylinder circuit bursts or is cut off, the balance valve in the hydraulic circuit works to lock the working oil from the lower cavity of the cylinder. The hoist will retract by itself to ensure the safety of the operation.

4. Height limit device: After the hook is raised to the specified height, touch the limit weight and turn on the travel switch, the “over-winding” indicator light will be on, and the hook lifting, boom extension, and hoisting will be cut off at the same time. Operate the arm to wait for the movement to ensure safety.

5. Outrigger locking device: When an accident occurs and the high-pressure hose or tubing leading to the vertical cylinder of the outrigger is broken or cut, the two-way hydraulic lock in the hydraulic system can block the outrigger and block the pressure oil in the two chambers of the cylinder to make the support The legs are not retracted or thrown out, so as to ensure the safety of lifting operations.

6. Lifting weight indicator: The lifting weight indicator is set on the closing side of the basic arm (that is, the right side of the control room), and the operator can clearly observe it when sitting in the control room, and can accurately indicate the boom The elevation angle and the rated lifting capacity allowed by the crane under the corresponding working conditions.

7. Lifting characteristics table: set on the lower wall panel of the front side of the control room, this table lists the rated lifting weight and lifting height under various boom lengths and various working ranges for easy reference during operation. During the lifting operation, the value specified in the table must not be exceeded.