Working Principles of Crane Related Safety Devices

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 cavity of the cylinder Oil, so that the boom will not fall, thus ensuring the safety of the operation.
3. Boom telescopic safety device: when accidents occur, the high-pressure hose or tubing in the boom telescopic 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 lifted to the specified height, touch the limit weight, turn on the travel switch, the indicator light will light up, and cut off the hook lifting, boom extension, and boom Ensure safety by waiting for the operation of the action. At this time, as long as the handle is operated such as lowering the hook, retracting the boom or raising the boom (that is, operating to the safe side), the limit weight is released from the restraint, and the operation returns to normal. In special occasions, if you still need to do a small amount of bypass operation, you can press the release button on the meter box, and the function of the limit will be released at this time, but the operation must be very careful at this time to prevent accidents.
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, so that 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). The operator can clearly observe 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.