2 * Study on Improvement Methods of CMM (Coordinate Measuring Machine) in Workshop Environment – Correction of Squareness Error – Tohru OHNISHI, Shotoku TAKASE and Kiyoshi TAKAMASU In recent years, the CMM (Coordinate Measuring Machine) quickly has been spreading in the manufacturing industry. With this phenomenon, the environmental condition and installation site of CMMs has been changed from the temperature control room to the workshop environment and the production line without air conditioning. However, even in severe environment the demand to high accuracy measurements by CMM has been enhancing still more. Therefore, the methods to evaluate and realize the high accuracy measurements by CMM in workshop environment have been investigated. In this paper, we propose the evaluation and correction method of squareness errors using MCG (Machine Checking Gauge). Additionally the performances of CMM in workshop environment and temperature-controlled room are tested and corrected experimentally. From these results, we confirmed the availability of the proposed methods. Key words: CMM, coordinate measuring machine, workshop environment, squareness error correction 1. Coordinate Measuring Machine CMM CMM CMM 1) 2) CMM CMM CMM CMM CMM 1 2 CMM 3 1) CMM 21 CMM 3)~6) CMM CMM X Y Z * 18 12 14 ** 1-1-12 *** 7-3-1 精密工学会誌,73(7),2007,818-822
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2 · 45 txy 4 a c e 45 45 X tzy 4 c d e 45 45 Y tzx 3 Sq MCG 3. CMM MCG 3.1 CMM-1 CMM-2 MCG 1 CMM CMM-1 CMM CMM-2 CMM 5 CMM-1 CMM-2 MCG 101 mm 151 mm 226 mm 380 mm CMM-2 380 mm CMM-1
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2 *
Study on Improvement Methods of CMM (Coordinate Measuring Machine) in Workshop Environment – Correction of Squareness Error –
Tohru OHNISHI, Shotoku TAKASE and Kiyoshi TAKAMASU
In recent years, the CMM (Coordinate Measuring Machine) quickly has been spreading in the manufacturing industry. With this phenomenon, the environmental condition and installation site of CMMs has been changed from the temperature control room to the workshop environment and the production line without air conditioning. However, even in severe environment the demand to high accuracy measurements by CMM has been enhancing still more. Therefore, the methods to evaluate and realize the high accuracy measurements by CMM in workshop environment have been investigated. In this paper, we propose the evaluation and correction method of squareness errors using MCG (Machine Checking Gauge). Additionally the performances of CMM in workshop environment and temperature-controlled room are tested and corrected experimentally. From these results, we confirmed the availability of the proposed methods.
R x, y,z R 101 mm 151 mm 226 mm 380 mm 532 mm 685 mm
2 45 845 45 8 24
3 72R
CMM
CMM1 20
2.2 MCG72 xi, yi, zi
x0, y0, z0 txy, tzx, tzy
1 Sc
CMM 3 3CMM x, y, z
X, Y, Z X xxy XY y
Y txy z Z X
tzx z Z Y tzy 3
2 3 Sqr
n
iiiic rzzyyxxS
1
220
20
20 )()()( (1)
zttzttzZ
ztytztyYztytxtztyxX
zyzxzyzx
zyzyxy
zxxyzxxy
coscostantan1
sincossinsin
22
(2)
222
1
2 rztzytztyxS izyii
n
izxixyiiq (3)
2.3 MCG 100 mm 3
Fig. 1 Construction and set up of Machine Checking Gauge (MCG), R is length between centers of pivot ball and stylus ball 11)
Fig. 2 Location of measuring positions by MCG; 8 positions on 3 difference Z levels (+45º, 0º, -45º) 11)
Y
Z
plane
Fig. 3 Coordinate systems and squareness errors by 3 angle error parameters txy, tzx and tzy; XYZ is coordinate system without squareness errors and xyz is machine coordinate system with squareness errors.