A shear angle online measurement system and method

Abstract

The invention belongs to the field of metal cutting machining, and particularly discloses a shearing angle online measuring system and method. The system comprises a cutter, a light transmitting sheet, a laser scanner and a lathe sliding table, wherein the cutter is clamped on the lathe sliding table, the light transmitting sheet is fixed above the cutter, and the laser scanner is mounted above the light transmitting sheet and fixed to the lathe sliding table. During measurement, the cutter cuts a workpiece, the light transmitting sheet presses cuttings between the light transmitting sheet andthe cutter when the cuttings of the workpiece are formed, and the laser scanner scans the outer contour of the thickness direction of the cuttings through the light transmitting sheet, so that the thickness of the cuttings is obtained, and then the shearing angle is obtained according to the thickness of the cuttings. Shearing angle measurement is completed in the cutting experiment process, thestructure is simple, installation is easy, the system can be used on common lathes, and meanwhile, measurement results are accurate and reliable.

Description

technical field [0001] The invention belongs to the field of metal cutting processing, and more particularly relates to an on-line measuring system and method for shearing angle. Background technique [0002] The shear angle is the angle between the shear plane and the direction of the cutting speed. It points out the shear direction of the cutting unit. Its size has an important influence on the metal deformation, cutting force and cutting temperature during cutting. It is a considerable part of the metal cutting process. important parameters. The larger the shear angle, the smaller the cutting deformation; the smaller the shear angle, the larger the cutting deformation. Many scholars have done a lot of research on the shear angle problem based on theories such as elastoplasticity, trying to establish the tool rake angle γ 0 , The theoretical relationship between the friction angle β and the shear angle φ on the contact surface between the tool and the chip, and many form...

AI Technical Summary

Problems solved by technology

DIC technology is to divide the deformation field into analysis areas of different sizes by taking two frames of images during the cutting process, track and match the pixel feature points on the surface of the object, and perform "correlation matching" by comparing the analysis areas before and after deformation. Yes, this method has good accuracy for in-plane displacement measurement. For right-angle cutting, if you use a 2D camera combined with DIC technology, although you can observe the separation process of chips and workpiece matrix in right-angle cutting, and then use DIC technology to calculate the shear The shear angle can be found by connecting the line of the point with the largest strain rate in the cut band, but this method is firstly in the case of an unstable light source, and the result of the matching algorithm is not stable; secondly, only the in-plane displacement can be measured , there is no way to calculate out-of-plane displacement, so it is not suitable for oblique cutting; third, the use of high-speed cameras is expensive, and it is difficult to install and use

If the binocular high-speed camera is applied to the measurement of the shear angle, it is necessary to match the chips in the images taken by the left and right cameras, and then use a series of image processing algorithms to extract the chips, restore the three-dimensional space coordinates of each point on the chip surface and simulate In order to obtain the desired chip thickness and calculate the shear angle, the workload is large and there are also problems of low robustness and high price.

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