How to judge the choice of Chengdu machinery processing factory?

Machining refers to the process of changing the external dimensions or properties of a workpiece through a mechanical device. According to the difference in processing methods, it can be divided into cutting processing and pressure processing. The machinery required for processing includes digital display milling machines, digital display forming grinders, digital display lathes, electric spark machines, universal grinders, machining centers, laser welding, medium wire walking, fast wire running, slow wire running, cylindrical grinders, internal cylindrical grinders, Precision lathes, etc., can perform turning, milling, planing, grinding and other processing of precision parts. This type of machinery is good at turning, milling, planing, grinding and other processing of precision parts. It can process various irregular-shaped parts with a processing accuracy of up to 2 μm. .

Machining technology refers to the whole process of using traditional machining methods to make the shape, size, relative position and properties of the blank into qualified parts according to the patterns and dimensions of the drawings. The processing technology is where workers process The work that needs to be done in advance to avoid processing errors during processing and causing economic losses.

The machining process is a step in the manufacturing and processing of workpieces or parts. The process of using mechanical processing to directly change the shape, size and surface quality of the blank to turn it into parts 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 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 product 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., and finishing machining may be divided into lathes, fitters, milling machines, etc. Each step requires detailed data, such as the roughness to be achieved and the tolerances. How much to achieve.

Technical personnel determine the process to be adopted based on the quantity of products, equipment conditions and quality of workers, etc., and write the relevant content into process documents, which are called process procedures. This one is more targeted. Each factory may be different because the actual situation is different.

In general, the process flow is the outline, the processing technology is the detailed parameters of each step, and the process specification is the specific processing technology written by a factory based on the actual situation.

Machining process flow:

Machining process specification is one of the process documents that stipulates the machining process and operating methods of parts. It is the process of machining parts under specific production conditions. The more reasonable process and operating methods should be written into process documents in the prescribed form and used to guide production after approval. Mechanical processing process regulations generally include 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, cutting amount, time quota, etc.

Machining production process:

The production process of the machine refers to the entire process of making products from raw materials (or semi-finished products). For machine production, it includes the transportation and storage of raw materials, production preparation, blank manufacturing, parts processing and heat treatment, product assembly, debugging, painting and packaging, etc. The content of the production process is very extensive. Modern enterprises use the principles and methods of systems engineering to organize and guide production, and regard the production process as a production system with input and output.

In the production process, any process that changes the shape, size, location and nature of the production object to make it a finished product or semi-finished product is called a process. It is a major part of the production process. The process can be divided into casting, forging, stamping, welding, machining, assembly and other processes. The mechanical manufacturing process generally refers to the sum of the machining process of parts and the assembly process of the machine. Other processes are called auxiliary processes. Processes such as transportation, storage, power supply, equipment maintenance, etc. The technological process is composed of one or several sequential processes, and a process consists of several work steps.

The process is the basic unit of the mechanical processing process. The so-called process refers to that part of the process that is continuously completed by a worker (or a group of workers) on a machine tool (or a working place) on the same workpiece (or on several workpieces at the same time).

The main characteristics of a process are that the processing object, equipment and operator do not change, and the content of the process is that the continuously completed work steps are carried out under the conditions of unchanged processing surface, unchanged processing tools, and unchanged cutting amount. The working stroke is the working steps completed by the processing tool once on the processing surface.

To formulate a mechanical processing process, it is necessary to determine how many processes the workpiece will go through and the order in which the processes are carried out. A brief process that only lists the names of the main processes and their processing sequence is called a process route.

The formulation of the process route is to formulate the overall layout of the process. The main task is to select the processing method of each surface, determine the processing sequence of each surface, and the number of processes in the entire process. The process route formulation must follow certain principles.

Machining production types:

Production types are usually divided into three categories:

1. Single-piece production: individually produce products of different structures and sizes. , and rarely repeated.

2. Mass production: The same products are manufactured in batches throughout the year, and the manufacturing process has a certain degree of repeatability.

3. Mass production: Products are manufactured in large quantities, and most work sites often repeat a certain process of a certain part.

Process procedure design, mechanical processing design principles:

(1) The designed process procedure should be able to ensure the processing quality of machine parts (or the assembly quality of the machine) and meet the design drawings the technical requirements specified above.

(2) The process should have higher productivity so that the product can be put on the market as soon as possible.

(3) Try to reduce manufacturing costs.

(4) Pay attention to reducing the labor intensity of workers and ensuring production safety.

Machining raw materials:

(1) Product assembly drawings and parts drawings.

(2) Product acceptance quality standards.

(3) Annual production program of the product.

(4) The production conditions of the manufacturing plant, including the specifications, performance and current status of machine tool equipment and process equipment, the technical level of workers, the ability of the factory to make its own process equipment, and the power and gas supply of the factory Ability and other relevant information.

(5) Design manuals and relevant standards required for process procedure design and process equipment design.

(6) Domestic and foreign advanced manufacturing technology data, etc.

Machining step content:

(1) Analyze and study the assembly drawings and parts drawings of the product.

(2) Determine the blank.

(3) Draw up the process route and select the positioning base surface.

(4) Determine the equipment used in each process.

(5) Determine the cutting tools, fixtures, measuring tools and auxiliary tools used in each process.

(6) Determine the technical requirements and inspection methods of each major process.

(7) Determine the machining allowance of each process and calculate the process dimensions and tolerances.

(8) Determine the cutting amount.

(9) Determine the working hours quota.

Machining allowance:

In the process of turning a blank into a finished product, the total thickness of the metal layer removed on a certain processing surface is called the total machining allowance of the surface. . The thickness of the metal layer removed in each process is called the machining allowance between processes. For rotating surfaces such as outer circles and holes, the machining allowance is considered from the diameter, so it is called symmetrical allowance (ie, bilateral allowance), that is, the actual thickness of the metal layer removed is the machining allowance on the diameter. Half. The machining allowance of the plane is the single-sided allowance, which is equal to the actual thickness of the metal layer removed. The purpose of leaving a machining allowance on the workpiece is to remove the machining errors and surface defects left by the previous process, such as the chilled layer, pores, and sand layers on the surface of the casting, and the oxide scale, decarburization layer, and surface cracks on the surface of the forging. , the internal stress layer and surface roughness after cutting. Thereby improving the accuracy and surface roughness of the workpiece. The size of the machining allowance has a great impact on both the processing quality and production efficiency. Excessive machining allowance not only increases the labor volume of mechanical processing and reduces productivity, but also increases the consumption of materials, tools and electricity, and increases processing costs. If the machining allowance is too small, it will neither eliminate various defects and errors in the previous process, nor compensate for the clamping errors in this process, resulting in scrap. The selection principle is to keep the margin as small as possible while ensuring quality. Generally speaking, the more finishing, the smaller the process margin.

Machining development status:

With the rapid development of modern machining, machining technology has developed rapidly, and many advanced machining technology methods have slowly emerged, such as micro Mechanical processing technology, rapid prototyping technology, precision and ultra-precision processing technology, etc.

1. Micro machining technology

With the development of Micro/Nano Science and Technology (Micro/Nano Science and Technology), micro-machining technology is characterized by its small shape and size or extremely small operating scale. Machinery has become a high-tech technology for people to understand and transform the microscopic world. Because micromachines can operate in a small space without disturbing the working environment and objects, they have broad application potential in aerospace, precision instruments, biomedicine and other fields, and have become an important means of nanotechnology research. It is highly valued and listed as the first key technology in the 21st century.

2. Rapid prototyping machining technology

Rapid prototyping technology was developed in the 20th century and can quickly produce samples or parts based on CAD models. It is a material additive processing and manufacturing method, that is, three-dimensional forming is completed through the orderly accumulation of materials. Rapid prototyping technology integrates modern scientific and technological achievements such as CNC technology, material technology, laser technology and CAD technology, and is an important part of modern advanced mechanical processing technology.

3. Precision and ultra-precision machining technology

Precision and ultra-precision machining are an important part of modern machining and manufacturing technology and are a measure of the level of a country's high-tech manufacturing industry. One of the important indicators. Since the 1960s, with the development of computers and information technology, higher requirements have been placed on manufacturing technology, which not only requires extremely high dimensional and shape accuracy, but also requires extremely high surface quality. It is under such market demand that ultra-precision machining technology has developed rapidly, and various processes and new methods continue to emerge.