The machining process specification is one of the process documents that stipulate the machining process and operation methods of parts. It is to write a more reasonable process and operation method in a prescribed form into a process document under specific production conditions. Used to guide production after approval. Machining process regulations generally include the following: the process route of the 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 cutting amount, the time quota, etc.
Steps to formulate process regulations
1. Calculate the annual production program and determine the type of production.
2. Analyze parts drawings and product assembly drawings, and perform process analysis on parts.
3. Select the blank.
4. Draw up the process route.
5. Determine the machining allowance of each process, calculate the size and tolerance of the process.
6. Determine the equipment and tools, fixtures, measuring tools and auxiliary tools used in each process.
7. Determine the cutting amount and working hour quota.
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 previously determined content to improve economic benefits. In the process of implementing process regulations, unexpected situations may occur, such as changes in production conditions, the introduction of new technologies and processes, the application of new materials and advanced equipment, etc., requiring timely revision and improvement of process regulations
The machining process is the process of manufacturing and processing workpieces or parts. The process of directly changing the shape, size and surface quality of the blank by mechanical machining is called the machining process. For example, the processing process of a common part is rough processing-finishing-assembly-inspection-packaging, which is a general process of processing.
The machining process is to change the shape, size, relative position and nature of the production object on the basis of the process to make it a finished or semi-finished product. It is a detailed description of each step and each process. For example, as mentioned above, rough Machining may include blank manufacturing, grinding, etc. Finishing may be divided into turning, fitter, milling machine, etc., each step must have detailed data, such as how much roughness should be achieved, and how much tolerance should be achieved.
The technicians determine the technological process to be adopted according to the quantity of products, equipment conditions and worker quality, and write the relevant content into technological documents, which are called technological regulations. This is more targeted. Each factory may be different because the actual situation is different. In general, the technological process is the outline, the processing technology is the detailed parameters of each step, and the technological procedure is a specific processing technology written by a certain factory according to the actual situation.
Forging-aging treatment-rough turning-normalizing-fine turning-heat treatment (quenching-tempering-aging)-rough grinding-fine grinding-chrome plating
Machining process
In the production process, those processes that are directly related to the transformation of raw materials into products are called technological processes. It includes blank manufacturing, parts processing, heat treatment, quality inspection and machine assembly. In order to ensure the normal process of the process, the manufacturing of tools and fixtures, and the adjustment and maintenance of machine tools are auxiliary processes. In the process, the shape, size, relative position and performance of the blank are gradually changed in a certain order by mechanical processing methods, until the part of the process that becomes a qualified part is called the mechanical processing process.
Technicians determine the technological process to be adopted according to the quantity of products, equipment conditions, and the quality of the workers, and write the relevant content into a technological document, which is called a technological procedure.
In order to facilitate the preparation, execution and production organization management of process regulations, the process needs to be divided into units of different levels. They are process, installation, station, work step, and knife pass. The process is the basic unit in the process. The machining process of parts consists of several processes. One process may include one or several installations, each installation may include one or several stations, each station may include one or several steps, and each work step may include one or several passes. .
(1) Process The part of the process that is continuously completed by one or a group of workers on one or several workpieces at a work site or on a machine tool is called a process. The division of processes is based on whether the work location changes and whether the work process is continuous. For example, to process a batch of axes on a lathe, you can either continuously rough and finish each axis, or you can rough the entire batch of axes first, and then finish them in turn. In the first case, processing includes only one process; in the second case, due to the interruption of the continuity of the processing process, although the processing is performed on the same machine tool, it becomes two processes. The process is the basic unit that makes up the technological process and the basic unit of the production plan.
(2) During the machining process, the process of making the workpiece occupy a correct position on the machine tool or in the fixture and be clamped is called clamping. Sometimes, the workpiece needs to be clamped multiple times on the machine tool to complete the work content of a process. Installation refers to the part of the process content completed after the workpiece has been clamped once. For example, when machining a shaft on a lathe, first process a part of the surface from one end, then turn around and then process the other end. At this time, the process involves two installations.
(3) When the work station adopts indexing (or shifting) fixtures, rotary worktables or machining on a multi-axis machine tool, after the workpiece is clamped on the machine tool once, it must pass through several positions for processing. The part of the process completed in each position occupied is called a station. To put it simply, the part of the process content that the workpiece occupies a processing position relative to the machine tool or tool is called the workstation. In order to reduce the clamping error and time loss caused by multiple clampings, various rotary tables, rotary fixtures or mobile fixtures are often used, so that the workpiece is processed in several different positions in one clamping.
(4) The part of the process that is continuously completed under the condition that the processing surface is unchanged and the processing tool is unchanged is called the process step. It is also often called “feed” in production. The whole process consists of several processes. Each process can include one step or several steps. Each step usually includes one work schedule, but may also include several work schedules. In order to improve productivity, the process of processing several surface processing steps with several tools at the same time is called a compound process step, which can also be regarded as a process step, for example, a combined drilling machine is used to process a porous box hole.
(5) The part of the process step completed by the cutting tool on the machined surface is called the cutting tool. For example, if the metal layer to be cut is very thick for shaft parts, it needs to be cut several times. At this time, each cut is called a pass. Therefore, the completion of a feed movement by the tool on the premise that the cutting speed and feed amount remain unchanged is called a pass.