Accident Case Analysis: Analysis and Prevention of Elevator Accidents

The types of elevator accidents can be divided into door system accidents, roof rushing or squatting accidents and other accidents according to the location of the accident system. According to statistics, the probability of all kinds of accidents in the total number of elevator accidents is about 80% for door system accidents, 15% for rushing to the top or squatting at the bottom, and 5% for other accidents. Door system accidents account for the proportion of elevator accidents and have the highest frequency.

2. Causes of elevator accidents and preventive measures

The defects of users or maintenance personnel and the potential safety hazards of elevators are the preconditions for elevator accidents. If one of the conditions is met, the elevator accident may or may not occur; But if both conditions are met, elevator accidents will definitely happen. If we understand or master this principle, we can effectively prevent elevator accidents when all conditions are not available.

(1) Defects of maintenance unit or maintenance personnel

Some maintenance units or maintenance personnel do not implement the principle of "safety first, pre-inspection and pre-repair, and planned maintenance", but treat the symptoms rather than the feet. They don't plan preventive maintenance, but wait until the elevator breaks down, which is both delayed and delayed. Some maintenance units or maintenance personnel even perfunctory, ignoring elevator safety.

Managers or maintenance personnel should strengthen the study of relevant laws and regulations, so as to abide by the law. Relevant departments should strengthen law enforcement and constantly improve the construction of laws and regulations.

(2) The elevator's own safety hazards and preventive measures.

The accident rate of door system is caused by the structural characteristics of elevator system. Because every operation of the elevator has to go through the process of opening and closing the door twice, the door lock works frequently and ages quickly. Over time, the mechanical or electrical protection device of the door lock is unreliable. If the maintenance and replacement are not timely, there will be hidden dangers in elevator operation, and accidents will easily occur.

The brake of the elevator is a very important part of the elevator, and the accidents of rushing to the top or squatting at the bottom are generally caused by the brake failure. If the brakes fail or there are hidden dangers, the elevator will be out of control and there will be no safety guarantee, and the consequences will be unimaginable. In order to effectively prevent roof caving accidents, we should not only strengthen the improvement of standards, but also strengthen the inspection, maintenance and repair of brakes.

Other accidents such accidents are mainly caused by the failure or unreliability of individual equipment.

3. Accident cases

(1) Door system accident 1

1July, 999 14, the elevator on the south side of Building Guangximenbeili 14 in Chaoyang District, Beijing opened the door to take the elevator, resulting in three third-floor residents' grandparents and grandchildren being cut while getting on the elevator, resulting in one death and one injury. On September 24th, 1998, the elevator of a bank in Shandong province also had an accident of opening the door and taking the stairs. On that day, a passenger entered the floor selected by the car and stood at the door waiting for someone to take the elevator together. At this moment, the elevator opened the door but ran down at normal speed, squeezing the passenger's head and jaw from the upper edge of the car and the sill respectively, causing serious injuries.

(2) Door system accident 2

1September 995 13, a vicious elevator accident occurred in a clothing factory in Shandong. The elevator is a 6-story 6-station passenger and freight elevator, XPJ type, with rated speed of 0.5m/s, rated load 1000kg, and the door lock is GS75- 1 1. Due to the early manufacture of elevators, the models of various parts have tended to be aging. Because of the frequent collision between triangle collision and hook lock, triangle collision has been ground into an inverted arc. In addition, the spring is aging, and the engagement depth is only 3 mm As long as it is outside the landing door, it is easy to open the landing door by hand. In view of this situation, the maintenance personnel have reflected it to the unit leaders three times, and all replied that the enterprise's efficiency is not good and the funds are tight, so they should use it first and talk about it later. On September 13, the workshop closes at 5: 30 pm. Because Gao was the team leader of the workshop, he left a little late from work, about 5: 40. He came out of the workshop (which is on the fourth floor) and found that the elevator was about to close. It was about 15m away from the elevator, so I quickly passed. At this time, the elevator has started and is moving quickly to the sixth floor. Gao opened it with his hand. This is a typical accident caused by managers and users not paying attention to safety.

(3) the top or squat accident

In the MBDS elevator on the 24th floor of a housing management office in Beijing, because the maintenance worker forgot to pull out the open-ended wrench when operating, the wrench became tighter and tighter with the vibration of the elevator, and finally the brake could not be closed. At this time, the elevator returned to the first floor, and the maintenance man was about to quit the car, only to find that the elevator came up automatically. Seeing that the elevator was getting faster and faster, he hesitated. He pressed the emergency stop switch on the roof, but it didn't help, and the maintenance man could do nothing. The elevator was out of control, accelerated to the 24th floor, roared to the top, and the maintenance workers immediately gathered and curled up at the lowest place on the car roof. A loud bang, a car; The middle item shook the whole building. The repairman's life was saved, but the car top rewinding wheel was hit by the floor, and a big bulge arched on the top of the machine room.

(4) Other accidents

1On August 25th, 999, two elevators were newly installed in a university in Northeast China. Li Hegao adjusted the distance between the elevator hall door and the car door knife. While they were adjusting the bolts, someone pressed the call button and the elevator quickly rose. Li was squeezed into the car and shaft on the side of the hall door on the sixth floor and died after being rescued.