What details should be paid attention to when using the lift? Chengdu lift manufacturer Nanguang Machinery summarized the following points for you.
1.Anti-fall safety device
An anti-fall safety device is an important part of a construction elevator. It is necessary to rely on it to eliminate the occurrence of a fall accident in the cage and ensure the safety of the occupants. Therefore, the factory safety test of the anti-fall safety device is very strict. Before it leaves the factory, it is measured by the legal inspection unit for torque measurement, critical speed measurement, and spring compression measurement. Each test report is attached to the construction elevator. After the drop test at rated load, the lift in use on the site must be tested every three months. The two-year anti-fall safety device (the date of manufacture of the anti-fall safety device) must also be sent to a statutory inspection unit for a test test, and it will be tested once a year in the future. So far, few people have submitted inspections, and some construction sites do not even do a fall test every three months, and they think that their fall safety devices are OK, but they will regret it if an accident occurs. Why not regularly test and submit for inspection according to the system? The using unit blindly believes that it is not bad and is considered good. In fact, the quality of anti-fall safety devices can only be judged by testing and inspection. It is not possible to determine whether they are good or bad in daily operation. For those anti-fall safety devices that are overdue, it is recommended that they be submitted for inspection and regularly. The test is good. Only by having a good idea in mind can we prevent vicious accidents before they occur.
2. Safety switch
The safety switches of the elevator are designed according to safety requirements, including fence door limit, cage door limit, top door limit, limit switch, upper and lower limit switch, counterweight anti-break rope protection switch and so on. In order to save trouble on some construction sites, some limit switches are artificially cancelled and short-circuited or damaged and not repaired in time, which is equivalent to canceling these safety lines of defense and planting potential accidents. For example, the hanging cage should be loaded with long things. If the hanging cage cannot be placed in the hanging cage, it must be extended out of the hanging cage, and the door limit or the top door limit is artificially canceled. In the case of the above-mentioned safety facilities being incomplete or incomplete, people are still carried. This illegal operation is a joke for human life. In order to avoid the hidden danger of the accident, I hope that the unit leader strengthens the management and strictly requires elevator maintenance and operators to regularly check the safety and reliability of various safety switches to prevent accidents.
3. Wear and replacement of gears and racks
Construction on the site, the working environment conditions are harsh, it is impossible to eliminate the cement, mortar, and dust, the mutual grinding of gears and racks, the teeth are still sharp, and they should still be used, which should be paid attention to. 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 is it necessary to stop using it and replace it with a new one? It can be measured with a 25-50mm common normal micrometer. When the common normal length of the gear is worn from 37.1mm to less than 35.1mm (2 teeth), it must be replaced with a new one. gear. When the rack is worn, it is measured by the tooth thickness caliper. When the tooth thickness 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-out" gears and rack elevators on the construction site. It is still in extended service and must be replaced with a new one for safety reasons.
4.Definition of temporary load rate
The elevators on the construction site operate frequently and have high utilization rates, but they have to consider the intermittent working system of the motor, which is often referred to as the problem of the temporary load rate (sometimes called the load duration rate). It is defined as FC = duty cycle time / load Time × 100%, where the duty cycle time is the load time and downtime. The lifts on some construction sites are rented by leasing companies, and they always want to make full use of them. The temporary load rate of the motor (FC = 40% or 25%) is completely disregarded. Why does the motor not generate heat? Some even emit coke The puddle is still used, which is very abnormal operation. If the transmission system is poorly lubricated or running resistance is too large, overloaded, or used for frequent starts, it is even a small horse-drawn cart. Therefore, every driver on the construction site must understand the concept of temporary load rate and work according to scientific rules. This motor is designed for intermittent operation.
The last line of defense for the safety of the construction elevator by the buffer on the construction elevator. First, it must be set. Second, it must have a certain strength, can withstand the impact of the rated load of the elevator, and play a buffering role. At present, there are many construction sites, although some are provided, but they are not enough to serve as a buffer. There is no buffer at all on the construction site. This is extremely wrong. I hope that the unit will pay attention to the inspection and do not despise this last line of defense.
6. Floor security door
Each docking floor of the construction elevator shall be provided with docking safety protection doors. Obviously, if it is not set as required, construction workers waiting at high altitudes are prone to accidental falls. When setting up the safety protection door, the height of the safety protection door should not be less than 1.8m, and the landing door should have an interlocking device. When the hanging cage does not reach the landing position, the protection door cannot be opened to ensure the safety of workers. At present, it is common on the construction site that people waiting for the construction elevator can open the safety protection door at any time. This is very dangerous and should be paid attention to.
According to the provisions of GB10055, "the foundation fence should be equipped with mechanical interlocks or electrical interlocks, and the mechanism interlock should only allow the hanging cage to be located at the bottom specified position before the foundation fence door can be opened. The electrical interlock should enable the protective fence to be opened. The cage is stopped and cannot be started. " There are quite a few construction elevators. When the hanging cage approaches the fence door, the bottom of the hanging cage presses a beam to run downwards, and the fence door is driven to open upward by the reversing pulley wire rope. This is not allowed, and it is easy to give to the nearby fence outside. People cause harm.
The wire rope heads at all parts should be reliably connected, such as pouring, braiding, forging, and using wedge-shaped solid pieces. If U-shaped rope cards are used, there must be no less than three. The number of rope cards and the distance between the rope cards are related to the diameter of the wire rope. Number of matching rope clamps. Rope diameter <1010-2021-2628-36. Minimum rope clamps 3456.
The distance between the rope cards is not less than 6 times the diameter of the wire rope, the length of the rope head from the last rope card is not less than 140mm, and it must be bundled with thin steel wires. The pulley of the rope card is placed on the side where the wire rope is working. At the tail end of the steel wire rope, rope cards should not be staggered in the forward and reverse directions. The steel wire rope should be fixed before being stressed, and then tightened after being stressed. However, due to weak safety awareness at many construction sites, when using rope cards to fix, the number of rope cards, card spacing, rope setting, tail length, etc. are arbitrary, and not according to the standard, resulting in a discount of connectors with only 80% -85% fixed strength. Leaving hidden dangers.
9.Control box on the top of the cage
GB10055 stipulates that "the top of the hanging cage shall be provided with a control box used for maintenance or disassembly, and it is allowed to operate at a speed not higher than 0.65m / s under a variety of speeds. The control box on the top of the hanging cage is used At this time, other operating devices are ineffective. At this time, the safety device of the hanging cage still plays a protective role. The control of the top of the hanging cage should be operated by a constant pressure button or a bi-stable switch. The top of the hanging cage should be installed with an emergency stop without resetting. The switch can cut off the circuit at any time and stop the operation of the cage. " This article is mainly for SC-type construction elevators. Few companies' products can meet the five requirements of the article at the same time: including products designed by some well-known design units. What are the disadvantages of not meeting these five requirements? There may be safety accidents due to misoperation by installation and maintenance personnel. It is hoped that the relevant users will carry out a comparative inspection of the construction lift, especially the old products. If they do not meet the above requirements, they should actively take measures to transform them.
10.Over-voltage, under-voltage, staggered phase protection
The over-voltage, under-voltage, and staggered phase protection devices are used when the voltage drop, over-voltage, and out-of-phase and out-of-phase faults occur on the electrical circuit. The protection device operates and the construction elevator stops running. Some lift maintenance personnel on construction sites do not remove the faults that cause the operation of overvoltage, undervoltage and phase failure protection devices in time, but cancel or short the protection devices to make them ineffective, leaving hidden dangers to the equipment. The product does not have this protective device at all, and it is recommended that it be equipped. The construction lift should be able to carry people under the conditions of over- and under-voltage, staggered phase protection device is reliable and effective.