Machining technology Countersinking, machining technology

The sequence of the steps for this threaded hole is as follows: drilling--- countersinking --- tapping. The purpose of countersinking is to make the flat gasket of the bolt have a circular plane, so that the contact surface can be flattened, so countersinking 18 is not good, because the outer diameter of the flat pad of M14 is 28, these are specified in the national standard, see figure:

d2 in the figure is the countersink diameter.

If you want to counterenter, you generally process the hole on the inclined plane or arc surface, and the drill bit is countersunk only when punching. Therefore, the countersinking process is generally before tapping the threaded bottom hole. After that, the bottom hole is chamfered and tapped.

Of course, if it is on the plane, you have to drill the bottom hole first, chamfer after countersinking, and finally tap! (The reason why the countersink is arranged after the bottom hole is processed is to ensure a certain degree of concentricity between the countersink part of the axis and the thread axis, so that the screw shoulder blade can completely rely on the countersink plane to form a large torque, so that the connection is reliable, of course, if you choose a CNC drill, it doesn't matter) (The following friend said that the countersinking is actually a means in the processing process, its purpose is to prevent the drill bit from being broken by unilateral force, and usually the countersink can be processed with a radial drill, because the cost is low, Moreover, the precision of the countersink itself is not high, and only the countersink is equipped with a guide core. The first countersink must make the blade pass the center, and the flat bottom drill should be selected and the non-standard tool needs to be sharpened).

Absolutely! In terms of countersinking processing, the operator can directly change a flat drill bit after drilling the hole, and it can be completed! It can be added to a process.

The machining process is the process of manufacturing and processing the workpiece or parts, and the process of directly changing the shape, size and surface quality of the blank by using the method of machining is called the machining process. For example, the processing process of an ordinary part is rough machining - finishing - assembly - inspection - packaging, which is a general process of processing.

Machining technology is on the basis of the process, change the shape, size, relative position and nature of the production object, etc., to make it a finished or semi-finished product, is a detailed description of each step, each process, for example, as mentioned above, rough machining may include blank manufacturing, grinding, etc., finishing may be divided into turning, fitters, milling machines, etc., each step must have detailed data, such as roughness to reach, tolerance to reach.

According to the number of products, equipment conditions and the quality of workers, technical personnel determine the process to be adopted, and write the relevant content into process documents, which are called process regulations. This one is more targeted. Every plant may be different, because the reality is different.

In general, the process flow is the program, the processing technology is the detailed parameters of each step, and the process specification is the specific processing technology written by a factory according to the actual situation. [1]

Machining process.

Machining process specification is one of the process documents that stipulate the machining process and operation method of parts, etc., it is in the specific production conditions, the more reasonable process and operation method, in accordance with the prescribed form written into the process document, after approval to guide production. The machining process specification generally includes the following contents: the process route of workpiece processing, the specific content of each process and the equipment and process equipment used, the inspection items and inspection methods of the workpiece, the amount of cutting, the time quota, etc.

1) Calculate the annual production program and determine the type of production.

2) Analyze the parts drawing and product assembly drawing, and analyze the process of the parts.

3) Select the blank.

4) Draw up a process route.

5) Determine the machining allowance of each process, calculate the process size and tolerance.

6) Determine the equipment and tools, fixtures, measuring tools and auxiliary tools used in each process.

7) Determine the amount of cutting and the quota of working hours.

8) Determine the technical requirements and inspection methods of each main process.

9) Fill in the process documents.

In the process of formulating process regulations, it is often necessary to adjust the content that has been preliminarily determined in order to improve economic benefits. In the process of implementing the process specification, there may be unexpected situations, such as changes in production conditions, the introduction of new technologies and new processes, the application of new materials and advanced equipment, etc., all require timely revision and improvement of the process regulations. [2-3]

It's such a simple shape, ah, I haven't forgotten the program in recent years! A few years ago, you could read the program out at the same time.