Hoist crane safety devices

Hoist crane safety devices
Hoist electric hoist crane is a  chain block  for the  lift hoist   Because of its simple structure, easy operation, low cost, machinery, chemicals, light industry, railways and other industries widely used. Because of this special  Manual block ,  ground operations often a person several roles, and also served as operations, company search, command tasks, there are many unsafe operating risks.
In order to prevent the occurrence of this type of crane lifting injuries, GB6067-1985 "crane safety regulations" and other relevant national standards has asked hoist cranes must have safety devices, such as limit switch, end stop, bumpers, safety braking devices. These security guards equipped to effectively improve the safety and reliability of hoist cranes, but because of the design, manufacturing defect itself a variety of reasons, the current hoist cranes inadequate security measures, according to the daily inspection experience Gourd found  hoist equipment  in the wrong phase-phase protection, anti-broken shaft protection against electric hoist fall protection, buffer settings, etc. are still flawed or inadequate.

Because hoist cranes conical brake three-phase asynchronous motors used as power plant, while the three-phase asynchronous motor rotation direction and the power supply phase sequence, and when the power supply phase sequence is changed, the motor rotation direction and the direction of the original operation Instead, press "down" button, spreader rise, and rise to the limit position limiter does not work, likely to cause accidents. Every year, this type of crane caused due to wrong phase crushed reel, hook group extrusion, wire rope pull off the accident. At present, China produced and widely used CD, MD  rope hoist did not take the wrong phase-phase protection measures (in the  chainb lock  did not require installation). To prevent the wrong phase injury accidents caused by lifting the hoist crane electrical control system added wrong phase-phase protection.

When the power supply occurs when the phase or out of phase, phase-phase protection functions, so that the total power contactors disconnect the power supply must be returned to normal after the crane can continue working. This is to prevent the power-of-phase induced roll crushing, and can prevent the motor phase operation is burning. Therefore, the wrong phase-phase protection role is essential.
Electric hoist during operation, the wheel rim and wheel tread wear, wheels and tracks ask gap increases, then ask if not promptly adjust the running clearance, electric hoist may fall out of orbit, causing lifting injuries ; and because of the particularity of the wheel axle assembly, axle difficult to detect cracks, cracks can not be effectively controlled, axle may break, causing the fall accident. To prevent the resulting electric hoist fall accidents can hoist the appropriate place additional anti-broken shaft, derailment protection device. Derailment occurred when the electric hoist or broken shaft, the anti-broken shaft, derailment protection device can effectively suspended from the track, so as to avoid lifting injury accidents.

According GB6o67-1985 (crane safety regulations "requirement, the terminal must be running hoist additional buffers. Because the device does not specify the installation location, the current domestic use electric hoist usually installed in the work buffer the middle of the word steel when the hoist running wheels collide with the buffer, the buffer has played a role in absorbing energy, but because of the special structure of manual hoist , hanging wheel rim run collision with the buffer, the inertial under the effect of the buffer suspension wheel rim wear extremely serious when the hoist operation for some time, the buffer will lose the original design function, so that during the operation of  Manual hoist  insecurity increases, electric hoist operation The sharp decline in almost stability in order to prevent this failure occurs, the installation location of the buffer can be selected in the lower surface of the beam, using the buffer and the lug plate suspended hoist collision cushion, increase safety and reliability and prolong the life of the buffer.