Research On Inspection Method Of Surface Integrity Of Injection Gear

Injection gear is a part that relies on the meshing of teeth to transmit the motion form.It has the advantages of small processing volume,wide applicability,and low cost.At present,it has been widely used in many different fields.Injection gears inevitably have defective products in the process of processing and production,and their surface integrity,as a key factor affecting performance and service life,is an important indicator of gear quality.Therefore,it is very important to check the surface integrity of such gears.Traditional inspection methods have high cost and low efficiency,and cannot meet the requirements of industrial inspection,while inspection methods based on machine vision have the advantages of non-contact,high precision,and high efficiency.Therefore,this thesis uses machine vision methods to detect the surface integrity of injection molded gears.The main research work is as follows:1.According to the analysis of system inspection requirements,select high-resolution cameras,low-distortion lenses,suitable light sources and reasonable lighting methods,build a visual inspection hardware platform,and design a system that combines software and hardware for surface integrity inspection of injection molded gears.2.The sub-pixel edge detection method based on Canny operator optimization is used to extract accurate gear edge contours,determine the position coordinates of the maximum circumscribed rectangle of the target gear,and cut out redundant background information to prevent gear translation from affecting the detection results.Speed up the calculation speed and improve the accuracy.3.The acquired image of the gear to be tested is matched with the image of the template gear respectively,and the similarity measurement coefficient between the two images is calculated as a standard for measuring the integrity of the gear to be tested.According to the testing requirements,theoretical analysis and experiments have determined that the threshold of the similarity measurement coefficient is 0.96,which realizes the judgment of the integrity of the injection gear.4.It further judges the position of the defect of the incomplete gear,which is used to feed back the manufacturing system and improve the process.In this thesis,a single gear template matching method is used to traverse each gear tooth to determine whether there is a tooth profile defect;through threshold segmentation of the gear end surface,the defect area of the gear end surface is extracted to determine whether there is a gear end surface defect.5.Finally,a large number of experiments on different types of injection gears are carried out to verify the feasibility of the method in this thesis.The experimental results show that the accuracy of the injection gear surface integrity inspection system is 99.33%and the average inspection time is 45ms.The inspection system meets the requirements of industrial inspection.