Relief Angle Inspection Of Twist Drill By Using Image-based Measurement Instrument

In recent years, the automotive, aerospace and electronics industries,People pay moreattention to the hole driving methods and tools. As drilling technology development，Almostevery kind of tool design, manufactur and regrind need to measure,measurement device is thetool production, grinding indispensable equipment. Dalian Polytechnic University tooltechnology research institute has developed an image processing based cutting tool geometrymeasurement apparatus. Engineering practices verified that it is particularly suitable inmachine shop applications with favorable performance/price ratio. But Loading platform isstill not achieve an automatic rotation. Select the location of the contour remain to bemanually. Personal errors are inevitable and harmful to system precision.The objective of the thesis work achieve automatic control of rotary loading station，.fulfill the requirement of automatic recognizing and measurement. This thesis details theprocess of system design, assembly, adjustment, and test-run.Relief angle determination of a twist drill is indispensable to its cutting performanceappraisal. But there is yet in want of effective evaluation method. This paper presents anautomated inspection system utilizing image-based measurement instrument. The procedure issummarized as follow: a twist drill, chucked in V-block horizontally, rotates around theperpendicular axis to half value of point angle. Then the projection of flank surface is a planarcurve. The tangent vector of this curve is calculated by using B-spline. The relief angleevaluation by using vector based approach is also detailed. The measurement apparatus usedwas developed in our laboratory years ago, currently available in the market named as DJLsystem. The maximum error of step angle is calibrated to be less than0.03°. As an example,relief angle of a standard drill is measured by using tool microscope and image-basedinstrument, respectively. Numerical results exhibit that average error and mean square error ofthe latter deviated from the former are0.27°and0.15°, respectively.It verifies the validity ofthe proposed procedure and measurement device.