In daily life, elevators are becoming more and more inseparable. However, we don’t know enough about its “temperament”. Xi'an Quality Supervision Bureau and Sanqin Metropolis Daily jointly launched the second series of "Quality Xi'an Quality First" series to see what are the misunderstandings about the safety of elevators? The professionals gave everyone a reassurance: "Let's say that even if all the steel cables are cut during the operation, there will be no sudden drop in the elevator, because there are more safety systems like the handbrakes and foot brakes of the car. The 'brain brakes, leg brakes', etc., the roads are very powerful, so the tragedy of the elevator accident is not caused by the quality defects of the elevator, many people have misunderstandings about it."
Misunderstanding 1 "You can get on the squeeze"
Sometimes the public enters the vertical elevator and “can be squeezed out”. This idea is wrong and there is a high risk. Under normal circumstances, the elevator overload causes the elevator to enter the self-protection mode and stop running. “When the carrying capacity of the elevator approaches the standard load-bearing capacity, the elevator will display full load, but it will continue to operate. If there is a large movement in the car, the elevator will be symmetrically unbalanced, immediately show overweight, and open self-protection. , stop working." If the elevator stops at the upper level and continues to be overloaded, the elevator is likely to slide down from the upper level.
Myth 2 "The elevator hall door is open but the elevator car is not on this floor"
Elevators are publicly used tools, and the most direct impact on public safety is the elevator doors. In design, the elevator hall door is tightly locked by the elevator door lock. Only when the elevator car runs to the door opening area, the door can be opened by the car door door knife. Under normal circumstances, the elevator hall door cannot be opened from the outside. Therefore, the reason why the elevator door is open but the elevator car is not on the floor is mainly: 1 the elevator door lock is faulty, the elevator management personnel operate illegally, short the elevator door interlock circuit, and open the elevator door operation; 2 Elevator management personnel operate illegally during maintenance and maintenance operations. They do not observe the actual position of the car and operate the elevator at will, causing passengers to mistake the elevator for opening the door, thus causing an accident.
Myth 3 Easy to knock or the ceiling can "escape"
"The elevator has two doors, one is the hall door, and the other is the car door. The automatic locking device is installed on the hall door. Once locked, unless the elevator car is in place, the hall door and the car door are coincident, otherwise the mechanical lock hook lock Death can not be opened." The relevant person in charge of Xi'an Special Equipment Inspection and Testing Institute said that in the event of an emergency, only professional licensees can open the hall door with a special triangular key to open the lock hook.
"The movie often plays up and pushes the ceiling out of the elevator scene. It is more exaggerated. Although there is an emergency exit on the top of the elevator, it is necessary to open the lighting ceiling and have a special key to open it." He introduced, and the elevator car top is The place where the maintenance personnel work is only the railings for work. The unfamiliar passengers are mistaken, not only cannot escape the well, but it is also very easy to cause danger and cause injury.
Myth 4 "The elevator hall door will open as soon as it is pushed"
The elevator hall door is the only way to take the elevator. The elevator door is hung in the upper door slot through the upper pulley. The upper positioning wheel and the lower door slider are engaged and positioned continuously, and the door is continuously opened and closed every day. The horizontal stress source of the elevator hall door is mainly the door. Its own gravity, so the hall door is one of the most dangerous parts of the elevator, and its daily maintenance is very important.
Comprehensive analysis, the main reason for the phenomenon that “the elevator hall door is pushed and opened” is mainly: 1 dust and sand accumulation in the upper door groove, reducing the depth of engagement of the upper pulley; 2 dust accumulation in the door groove or failure of the positioning wheel, hindering the opening of the hall door, Off, and the maintenance personnel adjust the positioning wheel at will, causing the pulley on the hall door to be non-engaged; 3 the dust and sand in the lower door slot, the lower slider is seriously worn, and the lower slider basically uses the colloidal material, and the horizontal stress is small.
Misunderstanding 5 Elevator failure will suddenly fall down
"The vertical elevator has a complete protection device, which is normally maintained and will not fall suddenly." He explained that the "sliding ladder" and "slide" that passengers said are actually illusions. The elevator has at least three security devices. First of all, the elevator has a brake. When a fault or power failure occurs, the brake will lock the traction motor and stop the rotation to ensure the safety of the elevator. Secondly, in the hoistway where the elevator is running, the upper and lower limit check switches and the forced deceleration switch are set. If the elevator runs to the end of the up and down, the elevator system will enter the forced deceleration and the state of development. Third, when the speed limiter detects that the elevator is overspeeding, the safety gear is braked to lock the car to the guide rail. "It is like two big pliers. Once the elevator speeds down, it will hug and prevent falling." If the elevator falls quickly to the bottom, there will still be a buffer at the bottom of the elevator to slow down the impact when the elevator is landing.
He introduced that in the process of elevator operation, if a small fault occurs and the elevator floor detection signal has a problem, the elevator will enter the protection restart state, automatically stop the corresponding button command, and return the floor data by returning to the lowest floor or the highest floor. Because of this process, the passengers could not control the elevator, and the elevator was always running, so everyone thought it was the elevator "slide" and "slide".
1 In the design of the elevator, the elevator car and the counterweight are respectively suspended at both ends of the stern wheel, and the elevator car is importantly lighter. When the elevator is idling, the lighter elevator car will not fall; 2 hanging There are at least five steel cables for the elevator car and the counterweight. Each wire rope is composed of multiple steel wires, and each wire rope can bear more than three times the weight of the elevator car. One-time break is impossible, not to mention. Said that the five breaks at the same time; 3 when the elevator running speed exceeds the rated speed, the speed limiter is triggered, the running power is turned off, and the safety gear is pulled at the same time to ensure that the car is stopped on the guide rail, and the electrical control loop is over The flow protection also stops running; 4 Modern elevator control uses the mileage coding method to automatically calculate the landing. When the elevator fails or the safety circuit protects, the elevator will automatically run to the base station (first floor).
In summary, the normal operation of the elevator is not able to appear "elevator suddenly falling down" phenomenon.
Misunderstanding 6 Why does the floor display turn to the 6th floor on the 8th floor?
When the elevator failed, the floor screen suddenly changed from the 8th floor to the 6th floor.” Many passengers questioned, the elevator “dropped” from the 6th floor to the 4th floor. this is too scary.
In fact, when the elevator is running, the floor corresponding to the displayed number is not very accurate. He explained that for the comfort of the passengers when the elevator is running, it is started, accelerated, decelerated and stopped according to a specific running curve. "Especially high-speed elevators, reaching the highest speed stage, the running distance exceeds 3 meters per second, that is, more than one floor height. However, in order to take passengers to the elevator's viewing habits, the displayed floor numbers are superimposed at a constant speed, so that passengers do not think that the elevator is When a fault occurs, if the elevator is in the process of starting acceleration or deceleration, there is a certain error between the actual position and the digital display floor. After the elevator self-protection stops, the floor display will automatically switch to the actual position. At this time, the passengers mistakenly thought that the elevator suddenly dropped several layers of illusion. In fact, the elevator stopped within the normal braking distance and did not slip.
Misunderstanding 7 Elevator failure is an accident
Some citizens may hear abnormal noise during the elevator ride, or the car may be slightly shaken during the elevator operation. In this case, there is no need to panic. According to reports, elevators will inevitably appear in a variety of situations during the operation, such as abnormal noise, jitter, emergency stop, and even sleepy people, etc. These are just elevator failures in operation, not elevator accidents. Elevator accidents are strictly defined. According to the relevant laws of special equipment, elevators can be considered as elevator accidents if they are stranded for more than 2 hours and the elevator causes serious injury, death or major property damage.
Misunderstanding 8 Elevator Pass = Elevator Accident
When the elevator is running, it is trapped by a sudden power outage. The first reaction of most people is "again the elevator accident." However, professionals analyzed that the elevator is actually a protection measure for passengers.
The elevator "gate" is actually a protection measure for the passengers when the safety detection system finds that the elevator has abnormal or faulty problems during the operation of the elevator. It is a protection measure for the passengers, not an elevator accident. If the elevator does not automatically stop running when an abnormality occurs, closing the elevator door may cause accidental injury.
“When the safety detection system finds that there are abnormalities or malfunctions in the elevator during the operation of the elevator, it automatically makes a normal response to protect the passengers. This is the case.” According to professionals, the power outage is essentially due to a sudden power outage. The elevator stops operating in the absence of electricity and stops the elevator car in the hoistway. The passengers who are locked in the elevator are safe at this time, and the maintenance personnel only need to manually release the passengers to release the passengers safely.
In the event of an emergency such as an elevator trapped person, first press the emergency alarm button to contact the duty officer on duty of the property company. Secondly, you can call the rescue unit to call for help. Remember, under no circumstances should you take dangerous actions such as climbing the car roof or forcibly opening the car door.
Misunderstanding 9 The door is closed and the elevator is broken.
Some households have reported that the unit elevators that live in their homes often have a door that is half open and can be locked or closed or closed. In fact, this situation is caused by the obstruction of the foreign matter in the elevator landing door slide, or the foreign matter in the light curtain area of the elevator door blocks the passage of light. The elevator door has safety contacts and the elevator will stop running as soon as the door opens. If the elevator car door or the hall door does not close the door for a certain period of time, the door interlock protection device will be activated and the elevator will automatically stop. In addition, excessive force such as strong slamming outside the elevator may also cause the door interlock to be disconnected and the elevator to stop running.
Misunderstanding 10 Stirring in the elevator will cause suffocation
Many passengers worry that after being trapped in a troubled elevator, in a small elevator, if they are not rescued in time, it will cause suffocation. In fact, at present, the national standards for elevators have strict regulations, and only when ventilation achieves the required effect can they be put on the market. In addition, some connection positions of the elevator car with the ventilation device, such as the connection between the car wall and the car roof, have gaps, which are generally sufficient for human breathing.
This article tags: Elevator Elevator knowledge Elevator failure Elevator shock Elevator error