What are the main safety devices on a double-girder crane?
To ensure safe and reliable lifting operations, cranes should be equipped with comprehensive safety devices to protect components or alert operators in the event of an emergency, thus providing safety protection.
1. Relief valves in the hydraulic system: These valves suppress abnormally high pressure in the circuit to prevent damage to the hydraulic pump and motor, and to prevent overload.
2. Boom luffing safety device: If an unexpected event occurs, such as a rupture or severed high-pressure hose or tubing in the boom luffing cylinder circuit, the balancing valve in the hydraulic circuit activates, blocking the flow of hydraulic oil from the cylinder's lower chamber, preventing the boom from falling and thus ensuring safe operation.
3. Boom extension and retraction safety device: If an unexpected event occurs, such as a rupture or severed high-pressure hose or tubing in the boom extension and retraction cylinder circuit, the balancing valve in the hydraulic circuit activates, blocking the flow of hydraulic oil from the cylinder's lower chamber, causing the boom to retract automatically, thus ensuring safe operation.
4. Height Limit Device: When the hook reaches the specified height, it contacts the limit weight, triggering the travel switch. The "over-wind" indicator light illuminates, simultaneously shutting down operations such as hook raising, boom extension, and boom lowering, ensuring safety.
5. Outrigger Locking Device: In the event of an accident such as a rupture or cut in the high-pressure hose or oil pipe leading to the outrigger vertical cylinder, a bidirectional hydraulic lock in the hydraulic system blocks the pressurized oil in both chambers of the outrigger locking cylinder, preventing the outrigger from retracting or extending, thus ensuring the safety of the lifting operation.
