The Design And Research Of The Unintended Car Movement Protection Device

With the increase of elevator production and demand,the safety of elevator is becoming more and more prominent.Most elevator accidents are caused by unintended car movement,it is a state of low speed moving,however,most of the elevator safety device in our country only in the case of a speeding car will be triggered.This paper designed a model of non-intervention unintended car movement protection device,which can be conveniently installed on various types of elevators,when the device detects unintended car movement,it can in timely stop the car and keep this state for protecting the safety of the passengers.Main work and research results are as follows:1.Analyzing the cause of the unintended car movement,according to the national standard,the paper determines the requirements which device needs to meet.According to the operation condition of the elevator,the paper designs the corresponding detection process and puts forward two kinds of schemes for the detection unit.2.Analyzing and comparing the controllers among the relay,PLC and microcomputer,the paper determines the PLC as the control unit;Designs the braking schemes which the speed limiter,brake and clamping wire rope are executive components,finally determines the overall scheme of the clamping wire rope as the actuator.The paper analyzes car's work environment and operation characteristics,the door system,the working principle of the brake,and completes the design of detection,control and execution unit.3.Based on the analysis of the unintended car movement,the paper designs a locking type redundant brake,and geometric modeling has been carried out.The strength and stiffness of the mechanism are checked by Workbench which improves the safety of car moving.4.According to the various situations of unexpected car movement,the corresponding ladder diagram is drawn in the CX-Programmer programming software,and the software design of the control system is completed.The specific experiment was carried out in an elevator company,and achieved the expected effect.This study is mainly oriented to the actual needs of unintended car movement protection,analyses and designs a model of non-intervention unintended car movement protection device,and the device is for the field test with the PLC programmer.This device can play a better protective role in the unintended car movement,and has certain guiding significance to the elevator industry.