September 2020 – Page 17 – CNC Machining & Turning, Milling, Metal parts

Development of machining technology

With the rapid development of modern mechanical processing, the rapid development of mechanical processing technology, slowly showing a lot of advanced mechanical processing techniques and methods, such as micro machining technology, rapid prototyping technology, careful and super careful processing technology and so on.

Micromachining technology

Mechanical products

With the development of micro / nano science and technology, micromachining, which is characterized by small size of its own mode or extremely small exclusive criteria, has become a kind of high-tech for people to understand and change the micro world. Due to the characteristics that micromachining can operate in a small space without disturbing the working environment and objects, micromachining has a broad application potential in aerospace, meticulous instruments, biomedical and other boundaries, and has become an important means to explore nanotechnology. Therefore, it is highly valued and listed as the first key technology in the 21st century.

Rapid prototyping machining technology

Rapid prototyping technology is developed in the 20th century. It can produce sample or parts quickly according to CAD model. It is a manufacturing method of raw material accumulation, that is to complete three-dimensional forming by orderly accumulation of raw materials. Rapid prototyping technology is an important part of modern advanced machining technology, which integrates CNC technology, raw material technology, laser technology and CAD technology.

Meticulous and super meticulous machining technology

As an important part of modern mechanical processing and manufacturing technology, careful and super careful processing is one of the important indicators to measure the level of a country’s high-tech manufacturing industry. Since the 60s of the 20th century, with the development of computer and information technology, higher requirements have been put forward for manufacturing technology, which requires not only high dimensional and geometric accuracy, but also high surface quality. It is in such a market demand that the over intensive processing technology has been rapid development, all kinds of processes and new methods are constantly

Reason of heat treatment in machining

Remove the internal stress of the blank. It is mainly used for casting, forging and welding parts.
Improve the processing conditions to make the raw materials easy to process. Such as annealing, normalizing, etc.
Improve the comprehensive mechanical function of metal raw materials. For example, quenching and tempering.
Increase the hardness of raw materials. For example, quenching, carburizing and quenching, etc.

Machining parts for the corresponding heat treatment process, which helps to improve the hardness, wear resistance and strength of machined parts, so that the accuracy and service life of machined parts are greatly enhanced.

Reasons for uneven cutting tools in CNC machining

In the process of processing, there will be a variety of problems, these problems are often occurred, may be because we do not operate well in the process of operation, caused by CNC machining is the same, so what are the causes of CNC machining tool imbalance?

The main reason for CNC machining is that the tool design is asymmetric, there are defects in the tool body, and all the adjustment of the tool. The correct balance of the tool can significantly reduce noise and vibration, which increases the tool life and improves the accuracy consistency of parts.

The centrifugal force of CNC machining center is proportional to the square of velocity to amplify the vibration caused by unbalance. The vibration increase of CNC machining center caused by the machining center minimizes the service life of bearing bush, bearing, shaft, spindle and gear.

Before balancing the tool in CNC machining center, it is necessary to measure the unbalance and the angle position of each selected correction plane. These variables are measured on two general types of balancing machines: non rotating or gravity machines are used to measure single plane unbalance, while rotary or centrifuge is used to measure single plane or two plane unbalance.

After measuring the magnitude and angle of the unbalance in the correct plane, you can correct it by adding or removing material from the workpiece. For the components which are not tools, the most widely used material adding method of drilling center is welding counterweight on the components

Advantages of CNC machining over general CNC machining

Now with the development of our industrial industry, many of the former processing methods and processing machinery are being replaced by new technology step by step, although some can not be completely replaced, but for the former, the new technology will always have some advantages better than the former, now we live in an era that will only get better and better, we need to keep up with the progress of the times Day we will talk about CNC machining relative to the general CNC what advantages?

It can process continuous and smooth free-form surface which can not be machined by general three-axis or it is difficult to finish machining by clamping at one time. For example, the blades of aeroengines and steam turbines, the propeller used in naval ships, and many shells and moulds with special curved surfaces and complex cavities and holes.
It can improve the machining accuracy, quality and efficiency of free-form surface. For example, ball end milling cutter is often used when machining complex curved surface by three-axis machine tool. Ball end milling cutter is formed by point contact, and the cutting efficiency is low. Moreover, the pose angle of cutter / workpiece cannot be adjusted in the process of machining. Generally, it is difficult to ensure that the best cutting point on the ball end milling cutter (i.e. the highest linear speed point on the ball head) is used for cutting, and it is possible that the cutting point falls on the ball end cutter, and the line speed of the ball end cutter is equal to The situation on the center line of rotation of zero.
Advantages of mold processing. In the traditional mold processing, the vertical machining center is generally used to complete the milling of the workpiece. With the continuous development of mold manufacturing technology, some weaknesses of the vertical machining center become more and more obvious. Ball end milling cutter is widely used in modern mold processing. The advantages of ball end milling cutter in mold processing are obvious,
Five axis machine tool processing technology can overcome the above shortcomings. The use of five axis machine tool processing mold can quickly complete the mold processing, fast delivery, better guarantee the mold processing quality, make the mold processing easier, and make the mold modification easier

Characteristics of CNC machine tools

CNC (numerical control machine tool) is the abbreviation of computer numerical control machine tool. It is an automatic machine tool equipped with program control system. The control system can process and decode the program with control code or other symbol instructions logically, so that the machine tool can move and process parts. Today we’ll take a look at its characteristics.

The operation and monitoring of CNC machine tools are all completed in this CNC unit, which is the brain of CNC machine tools. Compared with ordinary machine tools, CNC machine tools have the following characteristics:

1、 High machining precision and stable machining quality;

2、 The complex shape of the parts can be processed by linkage;

3、 When the machining parts are changed, only the NC program needs to be changed, which can save the production preparation time;

4、 The machine tool itself has high precision and rigidity. It can choose favorable processing amount and high productivity (generally 3 ~ 5 times of ordinary machine tool);

5、 High degree of automation of machine tools can reduce labor intensity;

6、 The requirements for the quality of operators are higher, and the technical requirements for maintenance personnel are higher.

Hardware processing steps

No matter what thing is operated or in the process, there are corresponding operation steps. We need to operate according to its operation steps and strictly follow its method to process. Hardware processing is also the same. What are the operation steps of hardware processing?

1、 All employees of hardware processing shall check whether their clothes meet the work requirements before entering the work post. Slippers, high-heeled shoes and clothes that affect safety are not allowed. Those with long hair should wear safety helmets. Keep correct posture when working, have enough spirit to deal with the work. If you feel unwell, you should leave the post immediately and report to the leader. During operation, it is necessary to concentrate on the operation, and it is strictly prohibited to chat and cooperate with each other. The operator should not operate under the state of irritability and fatigue, so as to avoid accidents and ensure the safety of operation.

2、 Before the machine works, check whether the moving part is filled with lubricating oil, and then start and check whether the clutch and brake are normal, and run the machine tool at idle speed for 1-3 minutes. It is strictly forbidden to operate in case of mechanical failure.

3、 When replacing the mold, the power supply should be turned off first, and the moving Department of the punch should stop running before the mold can be installed and debugged. After installation and adjustment, manually move the flywheel for two times to check whether the upper and lower dies are symmetrical and reasonable, whether the screws are firm, and whether the blank holder ring is in a reasonable position.

Dongguan Hardware processing

4、 Hardware processing must wait for other personnel to leave the mechanical work area, and take away the sundries on the workbench before starting the power supply to start the machine.

5、 After the hardware processing machinery is started, one person will transport materials and operate the machine. Others are not allowed to press the electric building or step on the foot switch board, nor can they put their hands into the mechanical working area or touch the moving parts of the machine with their hands. When the machine is working, it is forbidden to reach into the slider working area, and it is forbidden to take and place the workpiece by hand. The standard tools must be used when taking and placing the workpiece in the die. In case of abnormal sound or machine failure, the power switch should be turned off immediately for inspection.

6、 When off duty, the power supply should be turned off and the finished products, leftovers and sundries should be sorted out to ensure the clean and safe working environment

Hardware processing design principles

The design of a product is not as simple as we imagine, but there are relevant steps and methods to carry out the design. It is also necessary to operate strictly according to the method. The same is true for hardware processing. What is the design principle of hardware processing.

(1) the stamping parts of hardware processing design must meet the product application and technical performance, and be easy to assemble and repair.

(2) the stamping parts of hardware processing design must be conducive to improving the application rate of metal data, reducing the types and specifications of data, and reducing the data consumption as far as possible. Cutting and cutting materials to make use of as few scrap parts as possible.

(3) stamping parts must be simple in shape and reasonable in structure, so as to simplify the die structure and simplify the number of working procedures, that is, to complete the processing of the whole part with the least and simplest stamping process, reduce the use of other processing methods, and facilitate the stamping operation, facilitate the organization of mechanization and automation consumption, and improve the labor consumption rate.

Dongguan Hardware processing

(4) for stamping parts designed for hardware processing, under the condition of ensuring normal operation, the dimensional accuracy level and surface roughness level shall be lower as far as possible, which is conducive to the exchange of products, reducing waste products and ensuring the stability of production and quality.

(5) the stamping parts of hardware processing design should be conducive to the use of existing equipment, process equipment and process flow to stop processing, and to extend the service life of the die.

Prospect of CNC processing industry

CNC is also called computer gong, cncch or CNC machine tool. In fact, it is a kind of name in Hong Kong. Later, it was introduced into the Pearl River Delta of the mainland. It is actually a CNC milling machine. In Guangzhou, Jiangsu, Zhejiang and Shanghai, there are people called “CNC machining center”. CNC, milling machine, CNC machining, CNC milling machine, etc. Today we will talk about the prospect of CNC processing industry.

As an industry widely used in the market for mold processing and production, with the development of market economy, the decline of demand and the increase of peer competition pressure, technological breakthrough or price war is urgent.

1、 From the technical reform, the future development center must make a breakthrough from the most basic technology, realize the multi-directional upgrading from the mechanical and operational aspects, and achieve the technical update of the industry. Only with unique technology can we better cope with the future competition.

2、 In terms of service improvement, the competition in the industry is not only in technology, but also in service. Service is the relationship. If the service is done well, customers will continue to choose cooperation. Therefore, in the limited time, we should improve the service in essence.

Installing CNC machining center environment

Generally speaking, only living objects will pay more attention to the impact of the environment, did not expect to say that mechanical installation also has requirements on the environment. CNC machining center’s powerful processing ability can bring very high work efficiency for enterprises. The premise is that the installation environment is good, so today we’ll learn about the requirements for the installation environment?

Location requirements

It should be far away from the vibration source and direct sunlight. If there is a seismic source nearby, an earthquake proof trench should be set up.

Temperature and humidity

The optimal processing temperature of CNC machining center is below 30 ℃. If the ambient temperature and humidity are too high, the service life of the control system components may be reduced. If the ambient humidity is too high, it may lead to the short circuit and fault of the integrated circuit board.

Voltage and current control

There are many processing equipment in the workshop, which will cause excessive fluctuation of the power grid. We need to control the voltage and current within the allowable range of the machining center and keep it stable, otherwise the work of the system may be affected. The power supply shall be 380V ± 10%, three-phase AC

Automatic parts processing technology

With the continuous updating of the times, our requirements for products are also higher and higher. We must require the products to meet the standards or appearance. Dongguan automatic parts processing is one of them. What are the technical requirements for automatic parts processing?

1： When installing the hydraulic system, it is allowed to use sealing filler or sealant, but should avoid entering the system.

2： The parts and components entering the installation can be installed only with the certificate of inspection part.

3： The unmarked shape service shall meet the requirements of gb1184-80, and the allowable error of unmarked length shall be ± 0. 5mm。

Dongguan automatic parts processing

4： For fasteners with regular tightening torque, it is necessary to select torque wrench and tighten according to regular tightening torque.

5： Before assembly, strictly check and remove the residual sharp angle, burr and foreign matters during the processing of parts. Ensure that the seal will not be scratched during installation.

6： It is necessary to clean and clean the parts before installation, and there shall be no burr, flash, oxide scale, rust, chip, oil stain, colorant and dust, etc.

7： After the bearing outer ring is installed, the end face of the bearing cover at the positioning end shall be evenly touched. There shall be no scratch, scratch and other defects on the surface of the parts.