Design Of On-line Detection Device For Tension And Length Parameters Of Automobile Chain

In recent years,with the development of economy and living standards,the ownership of automobiles has increased rapidly,and automobile manufacturing has become the pillar industry of industrial economy.The transmission chain is an important part of the automobile transmission mechanism,which has a significant impact on the driving reliability and stability of the automobile.The length of center distance and tensile force are important quality indexes of automobile chain.In the process of operation,the center distance is lengthened,which will cause tooth skipping;the chain will be broken if the tensile force is not up to the standard,which will cause engine failure,light will cause abnormal engine noise,high fuel consumption,increased oil consumption and other problems,heavy will cause serious exhaust emissions,insufficient power and even unable to start the car.Therefore,these two problems need to be carried out before the chain leaves the factory Special detection of indicators.Traditional detection devices and manual detection methods have the problems of low detection efficiency,inaccurate detection data,and can not support the preservation,analysis and traceability of detection results.According to the actual needs of the enterprise,this paper designs and implements an on-line detection device for the length and tension of the automobile chain based on PLC and configuration technology.The distance between the centers of the test chain is 150 mm?550 mm,and the measurement error is less than 0.15 mm;the tension value of the test chain reaches 20 kn,and the error of the tension measurement is less than 1‰;the number of the on-line continuous test chains in 8 hours is more than 1000.The details are as follows:(1)This paper introduces the national standard of the automobile chain,analyzes the theoretical mechanics of the working state of the chain,puts forward the shortcomings of the current automobile chain tension and length parameter detection device,and points out the direction of improvement.(2)In the mechanical structure of the testing device,the structure of the horizontal four column worktable is designed based on the structural principle of the hydraulic press.The four column sliding support combined with the ball screw drive is adopted to reduce the influence of the gap error of the transmission structure on the testing accuracy.At the same time,the fast and stable movement of the testing platform is realized.(3)The detection device adopts configuration technology to design computer touch human-machine interface and backstage database,adopts double closed-loop control system of tension and length to automatically test the length and tension of automobile chain according to the requirements,the computer communicates with PLC through RS232 bus,PLC directly collects travel data through servo motor coding disk and communicates with special tension sensor through RS485 bus The tension data is collected by data acquisition,and the detected parameters are automatically recorded and analyzed in the computer database at the same time.(4)In the design of the software system,two detection modes are designed according to the actual needs of the enterprise,i.e.tension mode and length mode.Tension mode refers to the operation with the set tension as the target.After reaching the target value,maintain the tension according to the set time,and record the length after the time reaches;length mode refers to the operation with the set total length as the standard,and there is a window for setting the tension and the total length.When the total length does not arrive,but the tension reaches,the alarm light will be on,which is the default for this product to be unqualified.When the total length is reached,the pressure maintaining delay will be recorded and the total length corresponding to the tension will be recorded.The testing device designed in this paper is used in the practice of enterprises,the results show that it can meet the design objectives well,the system runs stably and reliably,solves the problem of on-line detection of the tension and length of the automobile chain,realizes the database function of product parameter recording,consulting and statistics,and supports the development of information technology in the production of enterprises.