What windproof devices should be set up for crane work?
Safety protection device and function of crane1. overload limiterIt is a safety guard for cranes to prevent overload, also called a weight limiter. The safety function of the utility model is that when the crane load exceeds the rated value, the lifting action is stopped, so as to avoid overloading. Overload limiters are widely used in bridge type cranes and elevators. Some boom type cranes (such as tower cranes and gantry cranes) use the overload limiter and the torque limiter together. Overload limiter has mechanical, electronic and many types.(1): mechanical drive ram through a lever and a spring cam, etc., when overloaded, hit the switch control rod and the lifting action phase, cut off the power source of hoisting mechanism, control the lifting mechanism to suspend operations.(2) electronic: composed of a sensor, an operational amplifier, to control the actuator and load indicator, display, control and alarm and other security functions in a body. When the crane is loaded, the sensor on the load bearing component is deformed, and the load weight is converted into an electric signal, and the value of the load is indicated by operation amplification. When the load exceeds the rated load, the power source of the lifting mechanism is cut off so that the lifting action of the lifting mechanism can not be realized.
4. windproof anti-skid safety deviceThe utility model is a safety device for preventing the crane of the open-air work from sliding along the track under the action of strong wind, and the outdoor working track type crane shall be installed. The safety function of the utility model is that when the crane encounters the maximum wind force in the non working state, the crane is not blown to prevent the crane from overturning at the end of the rail. Common windproof devices include rail clamps, anchoring devices, and iron shoes.(1) rail clamping device: it is widely used in all kinds of outdoor track crane, its working principle is to use the two sides of a clamp rail head, the crane is fixed on the track through the combination of the clamping force, the crane can not slip. The design requirements of rail clamp, clamping force of rail clamp must be greater than the crane sliding force, to ensure that the local maximum wind, crane stays closed; rail tongs should rely on device components own weight or spring, and should not only rely on the driving effect of the power of the driving device, to to prevent the power supply is interrupted, the rail clamping device does not work; power driven rail clamping action should be behind the operation mechanism of brake action violently to eliminate possible crane brake.(2) anchor device: it uses a bolt or a flashboard device, a chain or a top pole to connect the crane and the track foundation into one body, and is used for fixing the crane in the big storm when not working. Since the anchor device can only be located in a certain position of the track, the crane can be anchored to this position, which is not suitable for immediate weather protection in an emergency.(3) iron shoes: it is a wedge device, when used, the wedge-shaped tongue inserted between the wheel tread and rail top surface, the iron shoes of the slope constitute the resistance to sliding wheels.
2. torque limiterTorque limiter is an integrated safety protection device for jib cranes.We know that an arm crane represents the load condition from the moment of gravity. The load moment value is made up of product weight, amplitude decision, amplitude value is determined by the product, the boom of the crane arm length and angle cosine so that the crane is overloaded, in fact are the weight, arm length and arm angle limit, while also considering the working conditions and other parameters as well as constraints effect of control is more complex.At present, the widely used microcomputer controlled torque limiter can synthesize various situations and solve this problem better. The torque limiter consists of a load detector, an arm length detector, an angle detector, a work condition selector, and a microcomputer. When the crane to enter the working state, the computer will detect the signal input parameters of the actual working state, after operation, amplifying and processing, and advance into the rated load moment value, and at the same time in the display to display the corresponding actual values. When the actual value reaches the rated value of 90%, it will issue a warning signal when the actual value exceeds the rated load when the alarm signal, at the same time the crane to stop dangerous direction (lifting, boom, arm and rotary movements continue to drop).
