In order to ensure the safety and reliability of hoist cranes, cranes are generally equipped with sophisticated safety devices to prevent accidents and protect the machine or alert the operator.

Each relief valve in the hydraulic system suppresses abnormal high pressure in the circuit, thereby preventing damage to the hydraulic pump and motor to prevent overload.

The boom variable-width safety device can act as a balancing valve in the hydraulic circuit when the accident occurs, and the high-pressure hose in the boom-variable cylinder circuit or the tubing bursts or cuts, the lock generally comes from the cylinder The working oil of the cavity enables the boom to not fall, thus ensuring the safety of the work.

The boom telescopic safety device, when an accident occurs, the high-pressure hose or tubing in the boom telescopic cylinder circuit bursts or cuts, the balance valve in the hydraulic circuit acts, locks the working oil from the lower chamber of the cylinder, and causes the crane to hang Will retract yourself to ensure the safety of the job.

The height limit device, when the hook is raised to a certain height, touches the weight of the limit, opens the travel switch, and the indicator lamp of "over-winding" will light up, and at the same time, the hook is lifted and the boom is extended. The boom is slammed to the same action to ensure safety.

The leg locking device, when the high-pressure hose or the oil pipe leading to the vertical cylinder of the leg is broken or cut, the two-way hydraulic lock in the hydraulic system can block the pressure oil of the leg blocking the two chambers of the cylinder, so that the leg can not be shrunk or smashed Out, thus ensuring the safety of lifting work.

The lifting weight indicator is generally disposed on the side of the basic arm, that is, the right side of the operating room. The operator can clearly see when sitting in the operating room, and can accurately indicate the elevation angle of the boom. And the rated lifting capacity allowed by the crane under the corresponding working conditions.

The lifting characteristics table is set on the wall panel under the front side of the control room. The table can list the various lifting lengths and lifting heights under various working ranges for easy access during operation. When lifting work, do not exceed the values ​​specified in the table.

In order to ensure safe and reliable lifting work, the crane should be equipped with complete safety devices to protect the machine or alert the operator in case of accidents, thus providing safety protection.