Data name

Improvenment of quality and accuracy, and cost reduction by vacuum chuck

Overview

In this work, the finished thickness was as thin as 4mm. So, it was difficult to satisfy the surface roughness and processing accuracy. To solve the problem, the vacuum chuck was used, and it reduced the cost. 　Processed nember:50/lot

Finished size:　135×405×ｔ19.5 Minimum thickness after engraving: 4ｍｍ Material　A6063 Material dimension:　150×415×ｔ20

Point

Problems like clamp distortion, vibration, processing atrain were solved by vacuum chuck, and it enhanced processing accuracy, and connected to cost reduction.

Result

There was no vibration, clamp distortion or processing distortion at all, and the processing has finished without problems. Machining accuracy in thickness direction was less than 5μ. 　コCost was reduced by 41.8％. Shortening factor of the processing time ・The setup time was reduced with one jig. ・Installation and removal time was shortened, because the processes such as the tightening of the bolts have disappeared. ・Before the improvement, restraint of the whole work was not uniform, so, vibration was significant, and it was impossible to improve the cutting condition. ・With the vacuum chuck, the entire workpiece is pressed uniformly, so, even if the cutting conditions were severe, there could be no vibrations.

Commentary

Befor improvement, this work required five step processings, and the cost performance and quality of the product was bad. First and second steps 　Machining 135ｍｍ dimensions using vise（4 piles layered） The third step 　Processing of the item using the vice （above, left picture: round hole, elliptical hole, square hole to the point where it penetrates in the next process). Fourth Step 　Processing of the shaded area (the figure below) using the 5 clamps. Problem 　When the thickness of the remaining plate became thin, vibrations had occurred, and surface/ dimensional accuracy were not attained as we expected. So, we dropped cutting conditions, and restrained vibrations. ★Previously, this process was done by using a vice, but it caused more vibration than the current situation. Fifth step 　Processing of the shaded area (the figure below) using the four clamps. Problem 　As with the fourth step, when the thickness of the remaining plate became thin, chattering had occurred, and it did not finishas we expected. Process with vacuum chuck 　The machining processes could be reduced from 5 steps to 2 steps by usage of a vacuum chuck, and the jig was made to be commonly used in the 1 st and 2nd steps. In the first step 　Processing on the side of the work plane with three stopper pins on the jig. 　Jig (upper) and work (lower) 　（The work is a finished product. It's not in the middle of the processing.） In the second step 　1In the first sotp of machining, we used φ8 seat grinding for positioning, then advanced on the engraved side and outer periphery machining. 　Jig (upper) and work (lower) 　（Work is a finished product）

Coment

In most cases when using a vacuum chuck with a milling / machining center, the mounting base is specified for the workpiece. 　Since the clamping force of the vacuum chuck, when applied in the horizontal direction, is about 35％ of the perpendicular direction, the stopper pin is set up in this base. 　In the base, an O-ring groove for preventing leakage, and a leak groove for improving exhaust performance are processed. 　Neoprene sponge round cord is used as a O-ring for leak prevention. Toyoron hose is used for the line between the vacuum unit and the base. 　　This time, the base is processed using a machinen that processes the workpiece.