The measurement of hub chamfer symmetric alignment error

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  • source:MARSTEN CNC Machining
Axis kind the keyway of workpiece is sectional symmetric alignment error is 　 (1) 　 because axial chamfer median plane may tilt with axes, reason still should be measured along keyway length direction, take grow to be symmetric alignment error to the difference of the biggest reading 2 o'clock, its formula grows ＝ F for F tall - F low 　 (2) 　 is taken in sectional be worth with the error that grows to be measured up bigger person the symmetric alignment error that serves as keyway. To aperture kind workpiece, how is hub chamfer symmetric alignment error measured? The article is made at this point discuss. 1. Measure formula to be in graph 1 in, QB is keyway center plane, OE is include area center is planar, AO is line of fiducial aperture center and the distance with keyway planar center, Ⅰ - Ⅰ and Ⅱ - Ⅱ has been mixed for Q respectively B and OE parallel and distributing symmetrically at its both sides include face. If keyway deepness is H, the radius of aperture is R (the diameter is D) , keyway center plane measures ／ of AO ＝ A relative to the deflection of line of fiducial aperture center 2, QB of keyway center plane and include OE of area center plane (fiducial center is planar) included angle is α . Graph 1 　 will pursue 1 local enlarge, by the graph 2 know, BFE of Δ of Δ OAE ∽ , namely FE of ／ of BF of ＝ of OA ／ AE. Know ／ of OA ＝ α by the graph 2, ／ of H of ＝ of Β of Ε of Q Ε ＝ 2, ／ of BF ＝ F 2, 2 　 of ／ of H of ＋ of AE ＝ R have 　 thereby (3) because α part is very small, ≈ of reason Cos α 1, have 　 (4) 　 type (4) it is hub chamfer namely of sectional symmetric alignment error measure formula. Graph 2 　 　 2. Measure example aperture of workpiece of one hub chamfer is  34mm, groovy deep H is 10mm, groove is wide for 7. 6mm, measure its keyway symmetric alignment error. (1) sectional measure 　 ① 7. The gauge block of 6mm is built-in inside hub chamfer, by plane of center of keyway of gauge block imitate, the core axis of the 34mm that use  is inserted cooperate cheek by jowl with aperture inside workpiece, place core axis outfit in V on form piece, so OK by V form piece imitate is fiducial axes (namely aperture center line) , place next go up in flat, serve as with flat measure fiducial, adjust the plane on gauge block and flat parallel through instruction sheet. ② uses plan of TESA 　 MICRO-HITE2 height, get on next getting ready to measure above all inside the position of aperture center line, make its buy 0. ③ gets ready up and down again the place that measures plane of gauge block center, if reading of right now tall metric is 0. 13mm, namely keyway center plane measures A ／ relative to the deflection of line of fiducial aperture center 2 ＝ 0. 13mm, a ＝ 0. 26mm (if do not have high compasses, also can use rotate the axis the method of 180 ° measures a dimension A) . D ＝ 34mm, generation of H ＝ 10mm enters formula (4) , this value is namely measure sectional symmetric alignment error. (2) long to measure direction of edge keyway length to be measured the biggest reading 2 o'clock is poorly for 0. 015mm, this value is namely long to symmetric alignment error. Take sectional and grow the greater value to the middle of symmetric alignment error 0. 0591mm regards this hub as groovy symmetric alignment error. CNC Milling