| 摘要 |
PURPOSE:To improve positioning accuracy of a moving body by fitting a pair of longitudinally spaced moving pieces on the moving body and impelling one moving piece in the backward direction and the other moving piece in the forward direction by means of a magnetic attraction device arranged in a conveying passage. CONSTITUTION:A coil 13a and a coil 13b, when excited, exert backward thrust FA on a moving core 14a and at the same time forward thrust FB on a moving core 14b respectively so that a pallet stops at a position where these thrusts FA and FB equilibrate. Here, the distance DELTAX2 is greater than the positioning stop error DELTAX1 and therefore the magnitude f2 of the thrusts FA and FB is greater than the maximum friction force f1 occurring between the conveying passage and the pallet 8. Therefore, no positioning stop error due to friction between the conveying passage and the pallet 8 occurs. Thus, stop position accuracy is improved. |
