xiehe model

CNC machining center is a fully automatic machine tool that can automatically process. It has the characteristics of high processing efficiency, strong cutting force and high precision. With automatic tool change function, the workpiece can be processed in multiple processes at one time. In terms of flexibility, CNC machining centers can process various parts with complex shapes, and the adaptability of parts processing is very strong. This article mainly describes the processing technology of CNC machining center processing cover parts.

Precision parts processing requires milling, drilling, reaming, boring, reaming, tapping and other steps.

1. Parts process analysis

The CNC machining content of precision parts is that planes, holes and threads are concentrated on the A and B surfaces. The four sides of the side do not need to be processed, and the highest precision must reach IT7 level. Then we can use surface A as a positioning reference to process in the previous process, and select the working holes on surface B and B to process on the machining center.

2. Select cnc machining center

Since all the holes on the B side can be machined in one station, a vertical machining center can be selected. The machining contents of parts include rough milling, fine milling, rough boring, semi-fine boring, fine boring, drilling, reaming, countersinking, reaming and tapping. No more than 20 tools are required, so I choose CNC machining center to meet the above requirements.

The X-axis travel of the machine tool is 800, the Y-axis travel is 500, the Z-axis travel is 500, the worktable size is 1000×500, the distance from the spindle end to the worktable is 110-610mm, and the positioning accuracy and repeat positioning accuracy are 0.01mm. The storage capacity is 24, and the above-mentioned processing can be automatically completed after the workpiece is clamped once.

3. Design process

(1) Select the processing method

B side can be rough and fine milled: Φ60H7 hole dimensional accuracy requires IT7, roughness Ra0.8um, rough hole has been cast, rough boring + semi-finishing + fine boring: Φ12H8 hole dimensional accuracy requires IT8, roughness Ra0 .8um, in order to prevent drilling deviation, we can drill center hole-drilling-reaming-reaming: it is enough to drill Φ16 holes to the size on the basis of Φ12 countersunk holes; the threaded holes in M6 are in M20 and M20, then we can drill the bottom hole first, and then tap the thread.

(2) Determine the processing order

In order to reduce the number of tool changes, according to the principle of roughing and finishing first, face first and then hole, the processing route is: roughing, finishing, milling B-face—roughing, semi-finishing, and fine boring.

(3) Selection of tools

As far as the processing content is concerned, the tools to be used include milling cutters, boring cutters, center drills, twist drills, reamers, end mills and taps, etc. The specifications and sizes need to be selected according to the processing conditions.

(4) Determine the feeding route

The feed route of the rough and fine milling of the B face is determined according to the diameter of the milling cutter, and there are two feeds in the X direction. Since the required accuracy of the hole position is within the range that the positioning accuracy of the machine tool can guarantee, all the hole machining feed routes are determined according to the shortest route.

(5) Selection of cutting parameters

According to the determination of cutting tolerance and feed rate, then calculate the feed rate of the machine tool spindle at high speed.