Lever expresses pear form to measure the design of the head
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source:JANEZH CNC Machining
The measurement that common lever expresses the principle is the corner that the sine value that will measure a rotational point of view changes enlarge to be dial finger. In measuring a process, if be measured,the included angle of plane and space of measuring staff axis exceeds 5 ° , can cause more apparent additional indication error. To solve this one problem, our design made form of a kind of pear measure a head, if pursue,1 is shown. Through the lever to measuring a head of pear form the watch undertakes actual measurement experiments, the result makes clear, although be measured,the included angle of plane and space of measuring staff axis amounts to 30 ° , also won't cause more apparent additional indication error. Use pear form to measure a head to be able to raise the use precision of lever dial gauge and lever dial gauge, have certain promotion value. Graph 11. Pear form measures the mathematical model of head curved surface to measure a process to measure head curved surface to have main at 2 o'clock demand to pear form: (1) measuring range inside, random two linear length is due to it a paragraph of corresponding arc length; (2) the length that be measured is on the normal of curved surface and the point of tangency of the plane that be measured. Can judge from this, pear form curved surface should be a paragraph of involute rotate face, the basic circle the centre of a circle of involute is on the runner shaft of measuring staff, basic circle radius is the academic length of measuring staff, and length of measuring staff theory should be below the condition that removed error of theory of orgnaization of sine of original measuring staff recount comes out. Pear form measures a head to still be used in the part of basic circle less than spherical, its radius is Sr, but pushball face should rotate with involute join of face be identical. (1) Rd of basic circle radius (namely measuring staff length) computational lever watch measures a head to be in when the graph shows the position 2 times, have Sin of ／ of C of ＝ of α of Sin of ／ of Rdb of S ＝ α (β - α ) (1) β ＝ Arcsin [(C ／ B)sin (S ／ Rd) ] the S in type of Rd of ＋ S ／ -- α of of of lever watch span -- measuring staff has turned, ze of ／ of Z2 of ＝ of Z1 ／ Zx can get ／ of Zf of Z1 ＝ β ／ of ZfZe of β of ＝ of 2 π Z2 the Zf in type of 2 π Zx -- Zx of of of number of sector gear tine -- Ze of of of number of axial gear tine -- end panel gear, have Rad ＝ 2 π of ＝ of your Rad of ZxZn of ／ of ZfZe of β of ＝ of Zn of ／ of 2 π Z2, have β ＝ 2 π ZxZn ／ the type on ZfZe general and (1) type can get Arcsin quite [(C ／ B) Sin (S ／ Rd) ] ＝ of Rd of ＋ S ／ ZfZe of ／ of 2 π ZxZn or (C ／ B) Sin (. With Newtonian law the Qbasic program of the Rd that seek solution is: B of of 10 INPUT, c, s 16 of ＝ of Rd of of 20 LET 30 of ANT of ＝ of LET Bita (1) 8 of 40 of of of Ze of ／ of Zf of ／ of Zx Zn SIN of of B of ／ of C of ＝ of LET Y (S ／ Rd) - SIN (. 90 of of 00001 THEN 80 of 30 of GOTO 90 of PRINT " Rd ＝ " ; 100 of Rd END (2) of polar coordinates equation if the graph is shown 3 times,build, calculate above all the initiative horn A of involute of pear form curved surface. Graph Arctg of 3 θ ＝ (Sr ／ Rd) ＝ of A (π ／ 2) - θ ＝ (π ／ 2) - Arctg (Sr ／ Rd) the polar coordinates equation of curved surface of pear form is Tgt of Costinvt ＝ of ／ of ρ ＝ Rd - ｓ type is medium, if set allows the angle of axes of measuring staff deviate to be T0, criterion 0 ＝ of θ Tgt0 - 0 ＝ of θ of T0Sr ＝ Rdtg Rdtg (Tgt0 - T0) attention: The basic circle of spherical ball heart prep above that measures a root radius to be Sr. 2. The Qbasic program that the rectangular coordinates equation of the computational involute that involute face coordinate nods face chooses to beg involute face coordinate is as follows: Rd of of 10 INPUT, 20 of Sr ATN of ＝ of LET A (1) 2 - ATN (Sr ／ Rd) 30 of PRINT " T " , "X " , "Y " 40 of 0 of ＝ of FOR T 1 of TO STEP 0. 01 COS of ／ of Rd of ＝ of P of of 50 LET (T) 60 of TAN of ＝ of LET INVt (T) - 70 of T COS of of P of ＝ of LET X (INVt ＋ A) 80 of ＝ of LET Y, x, 100 of Y 0 of ＝ of IF X 120 of THEN 110 of of 120 END uses of of NEXT T the means that this program seeks pear form to measure the top of head to nod is as follows: After running a program, in replacing the 40th statement with penult T value " ＝ " several after date, and " STEP " the number after is multiplied with 0. 01. Operate repeatedly so, till Y value is in extremely before do not produce change till. Value of this one Y is apical M (0, ymax) medium Ymax value. Beg Xmax with the means that seeks extreme value next, computational formula is your, sin (Tgt - T ＋ A) Tgt ＝ Cos (Tgt - T ＋ A) solves a generation to enter thereby (3) type gets the lumbar way that can seek form giving pear to measure a head from this to be φ ＝ 2Rdarctg (Sr ／ Rd) ＝ 2Rdarctg [, the value of proper STEP chooses in the 40 statements of the program, get 60 many coordinate are nodded, the N feature that will contain Xmax and the M feature that contain Ymax are brought into among them, the form that states coordinate is nodded is made on blueprint. The concerned other dimension such as diameter of the acme that measures a head in the line out on view and pear form finally, waist and involute basic circle. CNC MillingCNC Machining