Research On Detection Method And System Of Ultra-narrow Gap Welding Groove Width

In recent years,with the increasing strengthening of economic ties between regions and the increasing intensity of resource allocation in our country,higher requirements have been put forward for the capacity and safety of transportation in our country.Especially for railway transportation,with the increase of train carrying capacity and number of times,in order to ensure the safe operation and service life of trains,higher requirements are put forward for the quality of rail welded joints.At present,the commonly used methods for rail welding have certain deficiencies,so researchers have proposed a more efficient,green and energy-saving flux band confined arc ultra-narrow gap welding method.Compared with flash welding and thermite welding,When the flux band confined arc ultra-narrow gap welding method is used for welding,the whole welding process is more complicated due to the further reduction of groove width at the welding site,and the welding quality is easily affected by various factors,of which groove width is one of the most important factors affecting the welding quality.When the flux band confined arc ultra-narrow gap welding technology is used to weld the welding base metal,If the width of the welding groove can be accurately detected,other welding parameters can be adjusted in time to ensure that the groove width matches with other welding parameters,which is of great significance for improving the quality of ultra-narrow gap welding and the automation level of ultra-narrow gap welding.Compared with other welding methods,when the flux band constrained arc ultranarrow gap welding method is used for welding operation,because the groove width at the welding place is further reduced,the detection difficulty of the groove width at the welding place is also sharply increased,making many current detection methods of groove width difficult to apply.This paper aims at the problems of low measurement accuracy and large measurement error in the process of manually detecting the groove width of flux band constrained arc ultra-narrow gap welding.By combining the welding process of flux band confined arc ultra-narrow gap welding technology with the structural characteristics of groove,Eddy current sensor is applied to the detection of ultra-narrow gap welding groove width in order to realize the pre-welding detection of ultra-narrow gap welding groove width and lay a foundation for further realizing the real-time detection of ultra-narrow gap welding groove width.Around this goal,this paper has carried out the following research work:(1)Based on the existing methods of weld groove detection and the basic theory of eddy current sensor,combined with the structural characteristics of ultra-narrow gap weld groove 4-6mm,a method of ultra-narrow gap weld groove width detection based on eddy current sensor is proposed,and the implementation scheme of ultra-narrow gap weld groove width detection system is proposed according to this method.(2)The development of the sensor module of the ultra-narrow gap welding groove detection system is completed.The influence of geometric parameters of the probe coil of the eddy current sensor in the weld groove on the sensor performance is studied by finite element method.According to the research results and the manufacturing process of the inductance coil,the probe coil of the eddy current sensor is developed.According to the requirements of the subject,the design of eddy current sensor circuit is completed by using constant frequency and amplitude modulation method,and the developed sensor is calibrated.The calibrated sensor is used to carry out dynamic gap measurement tests.The experimental results show that the sensor can meet the requirements of this paper.(3)The information acquisition system of ultra-narrow gap welding is designed and implemented.In order to accurately and quickly obtain the welding parameters in the welding process,this paper designs an ultra-narrow gap welding information acquisition system based on LabVIEW platform and data acquisition card USB-6361.According to the research of voltage signal and current signal in the process of ultranarrow gap welding in the early stage of the research group,the sensor suitable for collecting voltage signal and current signal is selected,and the signal acquisition program(such as data reading module,storage module,etc.)is completed accordingly.In addition,the groove width is also collected by using the information acquisition system,and the error of the ultra-narrow gap welding groove width detection system is analyzed.The experimental results show that,compared with the method of manually obtaining the groove width of ultra-narrow gap welding,the groove width information obtained by the ultra-narrow gap welding groove width detection system based on eddy current sensor is not affected by the operation errors of the staff,and the obtained groove width accuracy is higher and better.