With the increasing application of lifting platforms, users have insufficient awareness of safety management work, and some operators have poor quality and weak sense of responsibility. Many times, they do not check carefully before use, which has caused many hidden dangers to the safety of lifting platform equipment. For the sake of our own safety and to prevent irreversible losses, we must conduct a safety check before using the lifting platform. The following are the checks that must be done before using the lifting platform.
On site inspection
1. First, check if there is water accumulation in the foundation area and if there are signs of sinking. During the inspection, if a lifting platform is found to be installed on the first floor slab, the top support system and calculation plan of the basement must be checked; Check if the grounding system meets the requirements; The ribbon punch should be complete and effective; The bottom cage is tightly enclosed without any damage; The bottom entrance and exit of the elevator should have protective shelters.
2. During the inspection of the frame structure, the fastening of the foundation and standard section connection bolts should be checked, and the bolts should be equipped with double nuts or spring washers according to regulations; The welds in all parts are intact and free of cracks; The attachment rod should be set according to the material and specifications required in the manual, and should not be changed arbitrarily. The distance between the attachment rods should comply with the requirements of the instruction manual, generally 6m per piece; The connection and fastening methods of the attachment rod should be carried out according to the instructions and should not be changed arbitrarily. During the safety inspection process (gu ò ch é ng), it was found that steel bars were used instead of bolts, and steel bar heads were welded at both ends of the steel bars instead of nuts. This approach is very dangerous.
3. Mechanical transmission system: The mechanical transmission system of the lifting platform can be divided into two parts: closed and open. Its variable speed part and the centrifugal braking part of the cone drum speed limiter are enclosed. The other parts are open type. The enclosed part is not easy to inspect, and on-site inspection can only check whether the gearbox leaks oil and whether the inspection date marked on the cone drum speed limiter is overdue. Its inspection cycle is generally two years, and the cone drum speed limiter must be regularly monitored and sealed by the national safety monitoring center. The user unit is not allowed to adjust it arbitrarily. The inspection and testing of the opening part are different. Due to the wide range of points and limited time involved in safety supervision, it is more extensive compared to the safety inspection of elevators. In general, no instruments are brought and all rental experience is observed. To check, the clearance between each transmission part should not be too large, generally controlled at around 0.2-0.5mm. When the gear and rack mesh, the clearance at the bottom of the teeth is about 2mm. Excessive meshing clearance or severe wear of gears and racks are both very dangerous. The operation and braking force of the lifting platform must be transmitted through gears and racks. Insufficient meshing depth, severe wear, or excessive axial displacement can reduce the meshing area and cause a decrease in the strength of gears and racks, resulting in gear breakage accidents. In the actual safety inspection process, it was found that the gear rack of the elevator only hangs on the tooth tip, and the meshing surface cannot even reach one-third, which is very dangerous. The adjustment of meshing clearance mainly relies on the correct positioning of the rack guide wheel and guide rail roller. During the inspection process, it should be noted that the gap between the guide wheel and the rack should not be too large, generally between 0.2-0.5mm. The gap between the roller and the guide rail should also be controlled between 0.2-0.5mm. The elevator should run smoothly without any abnormal noise or noticeable vibration.
4. Safety devices for elevators. There are many safety devices for lifting platforms, mainly including the following more than ten types:
Prevent people from poking their heads out of the door.
There are various forms of installation for rope limit:
a。 When a rope breakage accident occurs due to the contact of an eccentric pulley, the pulley will fall in the direction and press the limit switch to cut off the power supply, causing the car to stop running.
If there is contact with a hinged pulley, the hinged pulley should have a reverse control spring to ensure that the pulley tilts towards the limit switch in the event of a rope breakage accident.
use. Press the emergency stop switch, and the lift platform car should stop immediately during the lifting process
(11) The sound of the alarm bell should be clear, and it should ring to warn before the elevator starts or stops.
(12) The anti fall device has been introduced in the mechanical transmission system and will not be repeated.
5. Electrical system:
(1) A switch box and leakage protector should be installed.
(2) Wires and cables should have good insulation, no damage, and no leakage. The metal hose for threading is free from rust and damage, and is reliably connected to zero.
(3) According to GB005588 regulations (gu ī d ì ng), the grounding resistance of the lifting platform should not exceed 4 Ω.
(4) Instruments, lighting, and control devices should be intact and sensitive.
6. Steel wire rope and pulley system:
(1) The specifications of the steel wire rope should be configured according to the instructions, without any broken strands or reduced diameter, and the number of broken wires should not exceed the scrap standard.
(2) The pulley operates flexibly, slides well, and the support is stable.
(3) The steel wire rope should be fixed with no less than four rope clamps at each end.
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