Research And Development Of Air Tightness Test System For Transmission Case

As the transmission mechanism and operating mechanism that change the running speed of the automobile,the transmission plays an extremely important role in the automobile.The insufficient sealing performance of the transmission housing not only affects the service life of the transmission,but also causes problems such as environmental pollution.In order to prevent leakage caused by insufficient sealing,it is necessary to develop a new,cost-effective and highly automated detection device to detect and analyze the leakage of the transmission housing.This article takes the transmission housing as the research object,and aims to study an efficient,high-precision,and high-reliability detection system to realize the air tightness detection of the transmission housing.The control system is required to realize automatic detection and the leak rate of detection can be obtained.The research content of this article is as follows:Compare and analyze various leak detection methods,and select the most suitable transmission case leak detection method-differential pressure air tightness leak detection method.The detection principle and influencing factors of the differential pressure air tightness detection method are analyzed,the detection parameters of the transmission case are determined,the leakage rate formulas for direct pressure detection and differential pressure detection are deduced,and the air tightness detection system of the transmission case is proposed.Design.According to the air tightness detection system scheme,a mechanical device that can realize automatic detection is designed,and a three-dimensional model of the mechanical device is established using CREO software.Developed a set of pneumatic system for transmission housing detection,used for leak detection and auxiliary mechanical device movement.Choose a robot,design a manipulator claw for grabbing the transmission housing according to the shape of the transmission housing,and use conveyor belts and industrial robots to feed and unload the mechanical equipment to achieve a high degree of automation in detection.For the unqualified transmission housing with leakage,a leak point detection system was developed for the location of the leak point,and the detection process of the leak point detection device was proposed.The hardware scheme of the control system is designed,the system control software is developed using PLC,and the PLC program and human-computer interaction interface are designed.The test tempo and experimental process were determined,and 50 sets of repeatability tests were performed on 50 transmission housings.Using the measurement capability indexes Cg and Cgk,50 sets of experimental data were analyzed and processed.The experimental results proved the accuracy and stability requirements of the designed mechanical devices,pneumatic systems,and control systems.