China Passenger Elevator manufacturers share how to ens […]
China Passenger Elevator manufacturers share how to ensure that the acceleration (deceleration) that passengers are subject to is always within a safe range?
1. Under normal operating conditions. For elevators in normal operation, the maximum value of the starting and braking acceleration (deceleration) speed recommended by the national standard shall not exceed 1.50m / s2, and the average value shall not exceed 0.48m / s2 (when the rated speed is 1.0 ～ 2.0m / s) and 0.65m / s (when the rated speed is 2.0 ～ 2.5m / s). It should be noted that this value is not a safety limit, but a comfort limit. Such a small acceleration (deceleration) speed will not only cause any discomfort to passengers, but it will become an "up and down enjoyment" to take the elevator.
2. When the safety clamp stops. When the moving speed of the car exceeds 115% of the rated speed, the elevator speed limiter will act. It first uses a device that meets the requirements of safety contacts to cut off the power of the elevator traction machine to stop it. At the same time, the brake action of the traction machine gradually stops the traction machine and keeps it at rest; if the car is cut off after the power is turned off The speed of the car is not reduced, and the speed limiter will immediately pull the car safety gear (or counterweight safety gear, or other forms of upward overspeed protection device) to stop the car-counterweight system. In the whole process of the car from motion to rest, its average deceleration is less than gn.
3. When the buffer stops. The top and bottom floors are the upper and lower end stations that cannot be surpassed by the car. If the car does not stop when it reaches the end station, the end station stop switch will send a signal to make the motor slow down and stop. At this time, if the elevator car continues to run, it will touch the limit switch to cut off the power of the traction machine, and the brake action of the traction machine will cause the elevator to decelerate and stop. If it still fails to stop the descending car at this time, the car will hit the buffer. When the car is equipped with the rated load and the speed reaches 115% of the rated speed, the buffer will cause the car to change from a moving state to a stationary state at an average deceleration less than gn, and realize a soft landing. The buffer on the counterweight side of the car going over the end station has the same performance.
4. When the brake of the traction machine stops. The brake is only open when the traction machine is powered on. When the traction machine loses power, the brake immediately acts and brakes the components directly connected to the traction sheave. If the speed of the traction machine is zero before the brake action, the traction machine will remain stationary after the brake action; if the traction machine is rotating normally before the brake action, after the brake action, the traction machine will be decelerated with a certain braking force until it stops. . The brake has such a braking capacity: when the car carries 125% of the rated load and runs downward at the rated speed, operating the brake can stop the traction machine. In this case, the deceleration of the car will not exceed gn. In order to improve the working reliability of the brake, all mechanical parts involved in applying the braking force to the brake wheel (or disc) are assembled in two parts. If one set of components does not work, the other set still has enough braking force to slow down the car carrying the rated load at the rated speed.