Figure 4 positioning disk 1 Size setting is based on the size of the workpiece, taking into account the T-bolt hole and the position of the indexing mechanism and other factors to determine its external dimensions. 2 materials used HT200 cast iron. 3 processing a. The outer circumference of the cast iron blank is clamped on the chuck to correct the outer end surface of the blank. The machining process is: flat end face → drilling 17mm through hole, then boring to 20 H8 → turning 100h6, length 10 mm boss → turning 70mm, depth 8 mm counterbore. b. Install the positioning plate with the mandrel and request to turn the 265mm outer circle according to the pattern. c. Use a chuck to hold the 265 mm outer circle and turn the other end to meet the pattern requirements. d. Grind the other end of the turntable with the end face of the boss as the reference (grinding plane, smoothing). e. On the digital drilling machine, based on the outer circle of the boss, drill and hinge two 20H7 mm mounting workpiece positioning pin holes according to the drawing. Drill out three 15mm T-bolt through holes and two M14 threaded bottom holes for clamping the valve body to tap the M14 internal thread. f. Using the digital drilling machine according to the pattern requirements, the drilled and hinged three 12H8mm indexing pin holes (the matching positioning pin and the indexing mechanism are shown in Figure 5). g. According to the drawings, drill three process holes of 24 mm and depth of 9 mm. 4 Install the valve body workpiece positioning pin hole, positioning pin (positioning pin part with the valve body) selection and accuracy calculation. a. Determine the center distance between the two positioning pins: the basic size of the centering distance of the two positioning pins should be equal to the average size of the two positioning holes of the workpiece (valve body) (see Figure 6), and the tolerance is generally Figure 5 indexing mechanism Image 6 Previous page next page Sheet Metal Fabrication,Cnc Bending Parts,Metal Flat Bracket,Customized Sheet Metal Fabrication JIANGSU TONGDE INTERNATIONAL TRADE CO.LTD. , https://www.tongdetrades.com
(2) Design and processing of the positioning plate (as shown in Figure 4) 
One-time installation of the multi-hole turning jig (3)