Analyze the hidden dangers of accidents during the use of the lifting platform, and propose corresponding preventive measures.

    Lifting platform is an indispensable construction equipment for vertical transportation of construction projects. The so-called barrier-free lifting platform of the projector elevator is mainly composed of a track and a lifting platform, which is similar to a simple small elevator. The track is inlaid on the wall of the entrance and exit of the passage, and follows the slope of the stairs to extend down to the inside of the tunnel. The lifting platform can be folded and placed against the wall when not in use, so that it will not occupy the space at the entrance and exit of the passage. When a disabled person in a wheelchair is in use, the four wheels of the wheelchair can be fixed on the platform, and after pressing the switch, the lifting platform can be controlled to enter the underground passage, which is safe and convenient.

The underground passage plans to install barrier-free lifting platforms, so what kind of design will the overpass? Yesterday, the staff of the municipal design department introduced that at present, except for Shenyang University's north-south campus and the North Canal pedestrian bridge, all the other three flyovers will be installed with "sightseeing elevators" to facilitate the access to the disabled.

Escalator lighting adopts induction type

The escalator in the underground passage will be designed as an induction elevator that runs 24 hours a day. It can be turned on automatically when someone passes through, and it will automatically stop working when there is no one. This can achieve the purpose of energy saving. In addition, in the 5 underground passages, Wanghua Street/September 18 underground passages are not designed with escalators.

The lighting equipment at the entrance and exit of the underground passage is also designed as a 24-hour voice-activated light, which will automatically light up when someone passes.

1. Anti-fall safety device

    The anti-fall safety device is an important part of the lifting platform, and the projector lifter must rely on it to eliminate the occurrence of the cage falling accident and ensure the safety of the occupants. Therefore, the factory test of the anti-falling safety device is very strict. Before leaving the factory, the legal maintenance unit will measure the torque, measure the critical speed, and measure the spring compression. Each unit is accompanied by a test lecture and assembled on the elevator. The drop test under the rated load is carried out, and the lifting platform in use on the construction site must be subjected to a drop test every three months. The anti-falling safety device of the lifting platform that has been delivered for two years (the date of delivery of the anti-falling safety device) must also be sent to the legal maintenance unit for inspection and testing, and then tested once a year. Few people have sent for inspection so far, and some construction sites do not even do a drop test every three months, thinking that their anti-fall safety devices are okay, but if there is an accident, they regret it. Why not test and submit for inspection on schedule? Using units blindly thinks that it’s good if it’s not bad. In fact, the quality of the anti-falling safety device can only be judged through testing and inspection. It is impossible to determine whether it is good or bad in daily operation. For those anti-falling safety devices that have been in service for an extended period of time, it is recommended to submit for inspection and inspection earlier. It is better to test on a regular basis, and only by knowing what to do, can we prevent serious accidents before they happen. (Detection of anti-falling safety devices can be sent to: Changsha National Construction Machinery Quality Inspection Center, Shanghai Academy of Construction Sciences, Shanghai Jiaotong University, etc.)

2. Safety switch

    The safety switches of the lift are all designed according to safety needs, including fence door limit, cage door limit, top door limit, limit switch, upper and lower limit switch, counterweight anti-break rope protection switch, etc. In some construction sites, in order to save trouble, some limit switches were artificially cancelled and short-circuited, or they were not repaired in time after they were damaged. That is to say, these safety lines of defense have been cancelled and hidden accidents have been planted. Example: The hanging cage needs to be loaded with long things, and the hanging cage cannot fit inside and needs to be extended out of the hanging cage, and the door limit or top door limit is artificially cancelled. In the case of imperfect or incomplete safety measures mentioned above, people will still be carried. This kind of illegal homework is a joke on human lives. In order to avoid hidden dangers of accidents, I hope to use unit leaders to strengthen governance and strictly require the maintenance of the lifting platform and operators to check the safety and reliability of various safety switches on schedule to prevent accidents. happen.

3. Wear and replacement of gears and racks

    Construction on the construction site, the homework environment is harsh, cement, mortar, and dust cannot be eliminated. The mutual grinding of gears and racks, and the teeth are still in use after they are sharpened, which should be faced squarely. As we all know, the tooth profile should be like a cantilever beam. When worn to a certain size, the gear (or rack) must be replaced. To what extent should I stop using it and replace it with a new one? A 25-50mm common normal micrometer can be used for measurement. When the length of the common normal of the gear is worn from 37.1mm to a size smaller than 35.1mm (2 teeth), a new gear must be replaced. When the rack is worn, it is measured by the tooth thickness caliper. When the chord height is 8mm, the tooth thickness is worn from 12.56mm to less than 10.6mm. The rack must be replaced. However, there are many "old teeth" gears and racks on the construction site. The lifting platform is still in overdue service. For safety reasons, new parts must be replaced.

4. Definition of duty cycle

    The elevators on the construction site frequently do homework and the utilization rate is high, but the problem of the interrupted work system of the motor has to be considered, that is, the problem of the duty cycle (sometimes called the load duration rate), which is defined as FC=work cycle time/load Time × 100%, where the working cycle time is the load time and the down time. The lifting platform on some construction sites is rented by a leasing company and always wants to make full use of it. However, the temporary load rate of the motor (FC=40% or 25%) is completely ignored. Why does the motor not have a fever? Some of them are still in use even with a burnt smell, which is a very abnormal operation. If the elevator transmission system is poorly lubricated or running resistance is too large, overloaded, or frequently started, it is even a small horse-drawn cart. Therefore, every driver on the construction site must understand the concept of duty cycle and act according to scientific laws. This kind of motor itself is designed according to the interruption work.

5. Buffer

    The last line of defense for the safety of the lifting platform of the buffer on the elevator, first, it must be installed, and second, it must have a certain strength, can withstand the impact of the elevator's rated load, and play a buffering role. And now many construction sites, although some have settings, but they are not enough to serve as a buffer, there is no buffer at all on the site, which is extremely wrong. I hope that the user unit will pay attention to the inspection and do not underestimate this last one. Line of defense.

6. Floor parking safety protection door

    Each docking floor of the lifter shall be provided with docking safety protection doors. The projector lifter is very significant. If it is not set up as required, the construction staff waiting at a high place can easily fall accidentally. When setting the parking safety protection door, ensure that the height of the safety protection door is not less than 1.8m, and the landing door should have an interlocking device. The protection door cannot be opened when the cage is not at the parking position to ensure the safety of homework staff. At present, there are generally employees waiting for the lift on the construction site who can open the safety protection door at any time. This is very dangerous and should be faced squarely.