Machinery industry – Page 6 – CNC Machining & Turning, Milling, Metal parts

What is machining center three axis, four axis

The spindle in the horizontal state of space is called horizontal machining center. Spindle can be vertical and horizontal conversion, known as vertical and horizontal machining center or five machining center, also known as composite machining center. According to the number of machining center columns, there are single column type and double column type (gantry type).

According to the coordinate number of machining center movement and the coordinate number of simultaneous control, there are three axis two linkage, three axis three linkage, four axis three linkage, five axis four linkage, six axis five linkage, etc. Three axis and four axis refers to the number of motion coordinates of the machining center. Linkage refers to the number of coordinates that the control system can control at the same time, so as to realize the position and speed control of the tool relative to the workpiece. Machining center can be divided into vertical, horizontal and composite machining center from the appearance. The spindle of the vertical machining center is perpendicular to the worktable, which is mainly used for processing plate and shell workpieces, and can also be used for mold processing.

The spindle axis of the horizontal machining center is parallel to the worktable, and its worktable is mostly a CNC rotary table controlled by servo motor. In the one-time clamping of workpieces, multiple machining surfaces can be processed through the rotation of the worktable, which is suitable for the processing of box workpieces. The compound machining center mainly refers to that there are two vertical and horizontal spindles on one machining center, or the spindle can change the angle by 90 degrees, so it can realize the machining of five surfaces in one clamping of workpiece.

What is vertical machining center

The spindle of the vertical machining center is perpendicular to the worktable, which is mainly used for processing plate and shell workpieces, and can also be used for mold processing. The spindle axis of the horizontal machining center is parallel to the worktable, and its worktable is mostly a CNC rotary table controlled by servo motor. In the one-time clamping of workpieces, multiple machining surfaces can be processed through the rotation of the worktable, which is suitable for the processing of box workpieces. The compound machining center mainly refers to that there are two vertical and horizontal spindles on one machining center, or the spindle can change the angle by 90 degrees, so it can realize the machining of five surfaces in one clamping of workpiece.

Machining center is usually divided into vertical machining center and horizontal machining center according to the state of spindle in space

The vertical machining center whose spindle is vertical in space is called vertical machining center, and the horizontal machining center whose spindle is horizontal in space is called horizontal machining center. Spindle can be vertical and horizontal conversion, known as vertical and horizontal machining center or five machining center, also known as composite machining center. According to the number of machining center columns, there are single column type and double column type (gantry type).

Safe operation of computer gong processing

When processing parts, the protective door must be closed, and the head and hand shall not be extended into the protective door. During the processing, it is not allowed to open the protective door;
In the process of computer gong processing, the operator shall not leave the machine tool without authorization, and shall keep a high degree of concentration and observe the running state of the machine tool. In case of abnormal phenomenon or accident, the program operation shall be terminated immediately, the power supply shall be cut off and the instructor shall be informed in time, and other operations shall not be carried out;
It is strictly forbidden to tap the control panel and touch screen. It is strictly forbidden to knock the worktable, dividing head, fixture and guide rail;
It is strictly forbidden to open the control cabinet of the numerical control system to watch and touch without permission;
The operator of computer gong processing shall not change the internal parameters of the machine tool at will. Interns are not allowed to call or modify other programs that are not compiled by themselves;
On the control microcomputer of machine tool, no other operation is allowed except program operation, transmission and program copy;
CNC milling machine belongs to large precision equipment. Except for the tooling and workpieces on the worktable, it is strictly forbidden to stack any tools, clamps, cutting edges, measuring tools, workpieces and other debris on the processing machine;
It is forbidden to touch the blade tip and scrap iron with hands. Scrap iron must be cleaned with iron hook or brush;
It is forbidden to touch the rotating spindle, workpiece or other moving parts by hand or in any other way;
It is forbidden to measure the workpiece and change the speed manually in the process of processing. It is also forbidden to wipe the workpiece with cotton yarn and clean the machine tool;
Trial operation is forbidden;
When using the hand wheel or fast moving mode to move the position of each axis, make sure to see the “and -” signs in each direction of X, y and Z axes before moving. When moving, slowly turn the hand wheel to observe the correct direction of the machine before speeding up the movement.

Fine blanking die technology

The continuous fine blanking die for complex parts is the frontier basic technology of fine blanking technology, and it is expected to promote the whole fine blanking technology in China. Taking the synchronizer gear ring, clutch plate, longitudinal compound continuous fine blanking process and continuous fine blanking die for complex parts as the breakthrough point, the key technology of fine blanking die design and manufacturing is studied, so as to realize the rapid improvement of fine blanking die technology in China and shorten the gap with advanced countries as soon as possible.

Study on the life promotion of fine blanking die and its related key technologies

Die life is a comprehensive reflection of die material, process and supporting product level. Taking die life of fine blanking as the leader to carry out technical research can not only solve the problem of low die life which is urgently needed in China, but also drive the technological development of die material, fine blanking process, supporting tooling and other auxiliary products.

Research and development of fine blanking precision forging composite technology

Precision blanking and precision forging are two advanced manufacturing technologies developed in parallel. If the precision blanking parts are too thick and need precision forging, if the precision forging parts are too thin, they must be precision blanking. They are interrelated and closely related. The basic idea of developing precision forging precision blanking composite process is to find the combination point of the two processes (such as gear parts with wheel hub and cam parts with short shaft). The precision forging in China has a long history and high level This is a good way to improve the overall technology level of our country.

High precision parts manufacturing concept

The concept, significance and characteristics of high precision parts manufacturing high precision parts manufacturing takes high precision mechanical parts as processing objects. Based on the systematic and integrated theory and technology, according to the structure and requirements of the workpiece, the organic combination and optimization of feeding, processing, detection and handling are realized, and the production of parts is completed under the precise processing conditions.
Application field of high precision parts and components high precision parts and components are used in all walks of life testing equipment – scientific instruments. In China, they are mainly used in the instrument and instrument industry of scientific instruments.
High precision machining has the advantages of high precision, low energy consumption, flexible production and high efficiency. Reducing the size of the whole manufacturing system and precision parts can not only save energy, but also save manufacturing space and resources, which is in line with the production mode of energy saving and environmental protection. It is one of the development directions of green manufacturing.
Compared with ordinary machinery manufacturing, precision machinery manufacturing has high technology content (design and production), excellent processing equipment, high added value, and small batch sales.
Analysis of foreign development situation high precision machinery manufacturing technology is known as one of the key technologies in the 20th century. It is the key development direction in the 21st century and has been highly valued by all countries in the world. Japan, the European Union, South Korea, the United States and other developed countries have invested a lot of human, material and financial resources to develop their own high-precision mechanical parts research and development and technology.

Requirements of steel processing by computer gong

Smelting quality for high-quality die steel, the processes of out of furnace refining, vacuum treatment, vacuum smelting, powder injection treatment and electroslag remelting are widely used at home and abroad to reduce the contents of harmful elements, oxygen, hydrogen and inclusions in the steel and fine tune the chemical composition and pouring temperature. By ESR, the macrostructure and density of the steel can be effectively improved, and the isotropy of the die steel can be improved. The tests in some domestic factories show that the transverse impact toughness of 4Cr5MoSiV1 steel produced by electric arc furnace is only 31% of the longitudinal impact toughness. After ESR, the transverse impact toughness of 4Cr5MoSiV1 steel is 70% of the longitudinal impact toughness, which is more than doubled. For the die steel with special requirements, the P / m high speed steel and P / m high alloy die steel can better improve the microstructure and properties of the steel.
On the basis of a certain forging ratio, upsetting drawing forging and cross rolling should be adopted as far as possible to improve the isotropy of die material. In order to reduce machining allowance and improve material utilization, precision forging machine, fast forging hydraulic press and high-precision continuous rolling mill are widely used to provide high-precision steel to meet the needs of mold manufacturing.
For heat treatment and finishing of forged and rolled products, controlled atmosphere or vacuum heat treatment should be adopted to avoid oxidation and decarburization. Some plastic die steel and hot work die steel should be pre hardened by Metallurgical Department. For some hot working die materials with high requirements, the Metallurgical Department should refine the structure in advance to eliminate the coarse carbides and chain carbides in the steel, and obtain fine and uniform carbides, so as to further improve the various properties of the steel, especially the isotropy. According to some foreign reports, some hot work die steels are produced with high quality and high directivity by electroslag remelting, multi-directional forging (rolling) and microstructural refinement. The transverse impact toughness can be equal to more than 90% of the longitudinal impact toughness. Many steel plants have named the steel produced by this process, such as isodisc of Bole steel plant in Austria, isotropy of Hitachi metal company in Japan, and microfine of gaozhoubo steel company in Japan. Many metallurgical production departments in China are also committed to this work. In addition, considering the metallurgical quality of various parts of steel, attention should be paid to make the main working face of the mold (such as cavity or edge) close to the surface of steel; because in general, the surface of steel is the clean part of steel, while the center of steel is the area where the macrodefects are concentrated; especially in the large section ledeburite steel, the center part is the center part The inhomogeneity of eutectic carbide in steel is 2-3 grades higher than that on the surface. In addition, the main load bearing direction of the die should be consistent with the deformation direction of the steel, so as to reduce the adverse effect of the anisotropy of the steel on the die.
Thermal conductivity thermal conductivity is also one of the main performance indicators of die steel, especially some hot work die steel and plastic die steel. Mold steel with good thermal conductivity can quickly transfer the heat generated in the processing and the heat from the workpiece, avoid overheating on the working surface of the mold, and improve the working conditions of the mold. For some thermoplastics forming dies and some die-casting dies, in order to speed up the pace of production, it is hoped that the pressed workpieces can be cooled and demoulded quickly to improve productivity. In order to solve this problem, sometimes some die materials with better thermal conductivity than steel are selected, such as high-strength copper alloy, high-strength aluminum alloy, etc.

Safety precautions – computer gong processing

When processing parts, the protective door must be closed. It is not allowed to stretch the head and hand into the protective door. It is not allowed to open the protective door during processing;
In the process of computer gong processing,

The operator shall not leave the machine tool without permission, and shall keep a high degree of concentration and observe the running state of the machine tool. In case of abnormal phenomenon or accident, the program operation shall be terminated immediately, the power supply shall be cut off and the instructor shall be informed in time, and other operations shall not be carried out;

It is strictly forbidden to tap the control panel and touch screen. It is strictly forbidden to knock the worktable, dividing head, fixture and guide rail;
It is strictly forbidden to open the control cabinet of the numerical control system to watch and touch without permission;
The operator shall not change the internal parameters of the machine tool at will. Interns are not allowed to call or modify other programs that are not compiled by themselves;
On the control microcomputer of machine tool, no other operation is allowed except program operation, transmission and program copy;
CNC milling machine belongs to large precision equipment,

It is strictly forbidden to stack any tools, clamps, cutting edges, measuring tools, workpieces and other sundries on the machine tool except for the tooling and workpieces on the workbench;

It is forbidden to touch the blade tip and scrap iron with hands. Scrap iron must be cleaned with iron hook or brush;
It is forbidden to touch the rotating spindle, workpiece or other moving parts by hand or in any other way;
It is forbidden to measure the workpiece and change the speed manually in the process of processing. It is also forbidden to wipe the workpiece with cotton yarn and clean the machine tool;
Trial operation is forbidden;
When using the hand wheel or fast moving mode to move the position of each axis,

Make sure to see the “and -” signs in X, y and Z directions before moving. When moving, slowly turn the hand wheel to observe the correct direction of the machine before speeding up the movement.

Center positioning datum – computer gong processing

1、 Selection of positioning datum for computer gong machining center

(1) Try to choose the design datum on the part as the positioning datum.

(2) One time clamping can complete the machining of all key precision parts.

(3) When the machining center not only processes the datum but also completes the processing of each station, the selection of its positioning datum needs to consider the completion of as many processing contents as possible.

(4) When the positioning datum and design datum of a part are difficult to coincide, the assembly drawing should be carefully analyzed to determine the design function of the design datum of the part. Through the calculation of the dimension chain, the tolerance range between the positioning datum and design datum should be strictly specified to ensure the machining accuracy.

2、 Selection and use of fixture for CNC machining center

(1) According to the characteristics and processing needs of machining center, the commonly used fixture types include special fixture, modular fixture, adjustable fixture, group fixture and workpiece unified reference positioning clamping system.

(2) The high flexibility of machining center requires that its fixture structure is more compact and simple than ordinary machine tool, clamping action is more rapid and accurate, auxiliary time is reduced as far as possible, operation is more convenient, labor-saving and safe, and enough rigidity and flexibility should be ensured. Therefore, pneumatic and hydraulic clamping devices are often used.

(3) In order to keep all the surfaces to be machined fully exposed, the fixture should be open as far as possible, and the space position of the clamping element should be low as possible, so there must be space for the tool path.

(4) Considering the minimum distance between the machine tool spindle and the worktable and the clamping length of the tool, the installation position of the fixture on the machine tool worktable should ensure that the processing content of the workpiece can be completed within the stroke range of the spindle.

(5) Automatic tool change and worktable exchange can not interfere with the fixture or workpiece.

(6) Sometimes, the positioning block on the fixture is used when installing the workpiece. In the process, in order to meet the processing of the front, back, left and right stations and prevent interference, the workpiece can be removed after clamping. In this regard, we should consider the problem of maintaining the positioning accuracy of the workpiece after removing the positioning element.

(7) Try not to change the clamping point in the middle of machining.

3、 CNC machining to determine the best position of parts on the machine tool table

报错笔记

High gloss traceless mold – brain Gong processing

Main features of high gloss and no trace die:

First, the mold forming temperature is higher. At higher mold temperature, injection molding can eliminate weld mark, flow mark, internal stress and other defects. Therefore, the mold needs to be heated when it is working. In order to prevent heat loss, the resin heat shield is usually added on the fixed mold side;

Second, the cavity surface is extremely bright (generally mirror 2 or higher). The products produced by high gloss mold can be directly used to assemble the whole machine without any surface treatment, so this process has high requirements for mold steel and plastic materials;

Thirdly, there are many hot nozzles in hot runner system (generally 6-8 nozzles, sometimes more). Each nozzle must be equipped with a sealing needle and an independent air passage, which can be controlled separately by solenoid valve and timing controller to realize time-sharing glue feeding, so as to achieve control and even eliminate weld marks.

High gloss traceless injection molding technology has some basic requirements for molds

The inner surface of the mould requires very high finish to ensure the surface quality of the products. The setting of pipes inside the mould must be reasonable to ensure rapid heating and cooling. The pipe inside the mold should have good thermal conductivity. Due to the need to keep heating and cooling in the production process, the mold needs to choose high-quality steel. In the process of use, we should pay special attention to the maintenance of the mold to ensure that it is dry and dust-free.

In addition, the performance and service life of high gloss traceless mold are directly related to the steel used in the mold. Due to different working conditions of plastic mold parts, the external influence is also different. Therefore, in addition to the basic requirements, the steel should also be emphasized. For example, large high gloss plastic mold cavity steel, in addition to the requirements of good cutting, EDM and welding performance, also need to have excellent throwing rotation and high hardness and other characteristics. This can not only form a bright and beautiful product, but also reduce the wear of plastic on the cavity surface, which not only extends the service life of the mold, but also reduces the injection pressure and protects the injection molding machine. At present, the high-performance and high gloss non marking die steels used in different processing conditions of flat-panel TV include polmax, lkm838h, lkm818h, s-star (a), NAK80, Stavax S136, Stavax s136h, Optimax, x13t6w (236), x13t6w (236h), etc.

Application in the field of home appliances

In recent years, the traditional CRT TV in the TV industry has been gradually eliminated, and replaced by the flat-panel TV with novel appearance, thin volume and high-grade visual sense. The surface quality of the front shell directly affects the grade of the flat-panel TV. However, the TV front shell produced by the traditional mold is difficult to eliminate the defects such as the surface weld mark and the surface finish is not enough, which can not achieve the beautiful effect. Therefore, it also needs to go through the secondary processing such as surface coating, which brings the problems such as the lengthening of the TV manufacturing cycle and the rising of the manufacturing cost.

High gloss traceless mold can solve the above problems of traditional mold. High gloss traceless mold technology has been rapidly applied in the home appliance industry since it was officially announced in the 2004 German rubber and plastic Exhibition: in 2005, Samsung of South Korea began to use high gloss mold technology to produce LCD TV shell, Chinese TV manufacturers also began to carry out the application research of this technology in 2006, and began to widely use it in the production of flat panel TV shell in 2008.

Introduction of CMM for CNC machining

This paper introduces the development of three coordinate measuring instrument, which is a new type of high efficiency precision measuring instrument developed in recent 30 years. It is widely used in mechanical manufacturing, electronics, automotive and aerospace industries. It can detect the size, shape and mutual position of parts and components, such as box, guide rail, turbine and blade, cylinder block, cam, gear shape and other space surface measurement. In addition, it can also be used for scribing, centering hole, photolithography integrated circuit, etc., and can scan continuous curved surface and prepare machining program of CNC machine tool. Because of its versatility, wide measurement range, high precision, high efficiency, good performance, and can be connected with flexible manufacturing system, it has become a kind of large precision instrument.

With the development of CMM market, CMM, as a modern large-scale precision instrument, has shown its importance and broad development prospects. It can measure the three-dimensional dimension of space conveniently and realize on-line detection and automatic measurement.

Its advantages are as follows:

It has strong versatility, can realize the measurement of spatial coordinates, and can easily measure the three-dimensional outline size and position accuracy of various parts;
The measurement is accurate and reliable
It is convenient for data processing and program control. Therefore, it can be incorporated into automatic production and flexible processing line, and become an important part. At present, CMM is developing rapidly at home and abroad. Famous foreign manufacturers include Zeiss and Leitz of Germany, DEA of Italy, Brown & Sharpe of America, Mitutoyo of Japan, etc. Since the development of CMM in 1970s, great progress has been made in China. The main manufacturers in China are China Aerospace Precision Machinery Research Institute, Qingdao Qianshao yingkefa measuring equipment Co., Ltd., Shanghai machine tool factory, Beijing Machine Tool Research Institute, Harbin Measuring Tool and cutting tool factory, Kunming Machine Tool Factory and Xintian optical instrument factory, etc. At present, China has the ability to produce hundreds of various types of CMM annually. With the development of various industries, the development of coordinate measuring instruments will also be rapid. Many small manufacturers choose second-hand CMM because they can’t afford to buy the new CMM, so the price is more favorable, and they can also use the new type of CMM imported work.