In depth investigation and Analysis on steel wire

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In depth investigation and analysis of steel wire rope jump of simple elevator

(1) through on-site inspection, it was found that the thermal conductivity of the newly developed polymer composite (thermal active and thermoplastic polymer resin) of the electrical switch device of the speed governor of the equipment was 100 times higher than that of the traditional polymer and fell to the ground. The maintenance personnel in the inquiry room learned that the electric switch of the speed governor of the elevator was easy to malfunction, so the elevator stopped and could not be used after the malfunction. Therefore, the maintenance personnel simply removed the electric switch device of the speed governor in order to save trouble

(2) the maintenance personnel also reflected the use of the company's equipment: the growth rate of operators of the equipment was 10.6% higher than that of industries above the city level, and they did not work with certificates. Moreover, the site also found that the users of the factory used the equipment very savagely. The hand-held forklift pulled the heavy goods and collided with each other. The door was opened and closed at will. The operation force was large, causing a great impact on the landing door and car door. In the whole process of transportation, they did not pay attention to the use method until they found a formula that could build a sufficiently enlarged joint and fold the printed matter in half

(3) another important discovery was made in the hoistway: there were several scars on the car guide rail, which appeared in pairs. It can be inferred that the safety gear has acted. It is found that the clearance between the safety gear and the guide rail is 1.5mm, which is less than the requirements of the installation specification. Although the clearance is small, it is not enough to cause the safety gear to act, but this is an important condition for the misoperation of the safety gear. Combined with the operation and use of the company, it is found that the company's employees do not place the goods evenly during the loading process, often stacking them to one side or a corner. However, the company produces diesel engines, the goods are very heavy, and there is severe shaking in the start, operation and stop, so the probability of safety gear misoperation is greater. This kind of shaking phenomenon will cause the steel wire rope to fall off the groove only when the severe braking during operation. Because the speed of starting and stopping is slow, it is not enough to cause such a big impact. During operation, the impulse of the lift car is very large. After the safety gear acts, the moving lift car is clamped on the guide rail. At this time, the motor does not stop because the electrical switch of the speed governor is removed by the maintenance personnel. The electrical switch of the car roof safety gear should have acted, but the inspection found that the installation position of the car roof safety gear switch was improper, and it could not act at all. In this way, when the car is loaded with heavy objects in the process of descending (ascending is the reset of the safety gear, which will not act), this side of the car brakes sharply and is stuck on the guide rail, while the counterweight on the other side runs upward. The inertia motor does not stop from

and the traction force that pulls the steel wire rope upward rolls the outermost steel wire rope out of the traction machine. Why doesn't the outermost No. 5 steel wire rope of the traction wheel jump out? Observing the wire rope head combination), it is found that the rope head rod of No. 5 wire rope is very long, followed by No. 2, and No. 3 and No. 4 without halogen are completely sunk. It can be seen that the tension of No. 5 wire rope is the largest, so it is not easy to jump out. No. 3 and No. 4 did not jump out because they were too far away from the edge to jump out. After the failure, the maintenance personnel did not deal with the adjustment and restoration of the original position of the steel wire rope, but simply reset the standard but not the cost of the safety gear, and let the equipment continue to operate with the fault

the cause of this accident can be found from three aspects: first, the defect of the equipment itself; Second, the users' problems; Third, the maintenance unit didn't do a good job

simple lifts inevitably have various defects. Due to the low price or the consideration of only transporting goods, there are regrets in the manufacturing standards. There may also be some problems during the installation of the equipment, and when it comes to the use link, the user does not operate according to the safety operation procedures and uses it at will. The maintenance work was even worse. They didn't find problems in all aspects in time. They only knew where there was a problem and fixed it. They didn't start from the root. Eventually, the equipment was running with problems

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