Yearly Archive September 17, 2020

CNC machining has the following advantages:

① The number of tooling is greatly reduced, and complex tooling is not required for parts with complex processing forms. If we want to change the form and size of parts, we only need to modify the part processing program, which is applicable to the development and modification of new products.

② The machining quality is stable, the machining precision is high, and the repeated precision is high, which is suitable for the processing requirements of aircraft.

③ It can reduce the time of production planning, machine tool adjustment and process inspection, and reduce the cutting time due to the use of good cutting amount.

④ It can be used to machine the complex surface which is difficult to machine by conventional way, and even can process some parts which cannot be observed.

The disadvantage of NC machining is the high cost of machine tools, which requires maintenance staff to have a high level.

1. What are the key points of CNC engraving and CNC milling?

Both CNC engraving and CNC milling are based on milling principle. Focus on the use of tool diameter, CNC milling commonly used tool diameter boundary is 6-40 mm, while CNC engraving tool diameter is 0.2-3 mm.

1. Is CNC milling only for rough machining and CNC engraving only for finishing?

Before answering this question, let’s first understand the meaning of the process. The amount of rough machining is large, while the amount of finishing is small. Therefore, some people habitually regard rough machining as “heavy cutting” and fine machining as “light cutting”. In essence, rough machining, semi finishing and finishing are the meaning of technological process, which represent the different processing stages. Therefore, the exact answer to this question is that CNC milling may as well do heavy cutting or light cutting, while CNC engraving can only do light cutting.

1. Can CNC engraving process be used for rough machining of steel raw materials?

To infer whether CNC engraving can process a certain raw material, the key point is to see how large a tool can be used. The cutting tool used in CNC engraving determines its comparative cutting strength. If the mold form allows the use of tools with a diameter of more than 6 mm, it is proposed to use CNC milling first, and then use engraving to eliminate the remaining raw materials.

1. Whether adding a speed increasing head to the spindle of CNC machining center can complete the engraving process?

It can’t be over. This kind of product appeared in the exhibition two years ago, but it was impossible to complete the carving process. The main reason is that the design of CNC machining center studies its own tool boundary, and the overall structure is not suitable for engraving. The main reason for this mistake is that they mistook the high-speed motorized spindle as the only feature of a successful engraving machine.

1. CNC engraving may use a tool with a small diameter. Can it replace EDM?

It cannot be replaced. Although engraving reduces the tool diameter boundary for milling, small molds that used to only be machined by EDM can now be completed by engraving. However, the length / diameter ratio of engraving tools is usually controlled at 5:1. When using small diameter tools, only a very shallow cavity can be machined, while EDM has almost no cutting force. As long as the electrode can be made, the cavity can be machined.

1. What are the key factors affecting the carving process?

Machining is a complex process, and there are many factors affecting it. The key points are as follows: machine tool characteristics, cutting tools, control system, raw material characteristics, processing technology, auxiliary fixture and surrounding environment.

1. What are the requirements for the control system of CNC engraving?

CNC engraving processing is milling processing first, so the control system must have the control strength of milling processing. For small tool machining, feed-forward performance must be provided at the same time, and the path speed can be reduced in advance to reduce the tool breaking frequency of small tool. At the same time, the cutting speed should be increased in the smooth path section, so as to improve the engraving efficiency.

1. What characteristics of raw materials affect processing?

The key factors affecting the engraving performance of raw materials are the type of raw materials, hardness and toughness. The category of raw materials includes metallic raw materials and non-metallic raw materials. In general, the higher the hardness, the worse the processability; the higher the viscosity, the worse the processability. The more impurities, the worse the processability, the greater the hardness of the particles inside the raw materials, the worse the processability. A general rule is: the higher the carbon content, the worse the processability; the higher the alloy content, the worse the processability; the higher the content of non-metallic elements, the better the processability (but usually the nonmetal content in raw materials is strictly controlled).

1. Which raw materials are suitable for carving?

The non-metallic materials suitable for carving include plexiglass, resin, wood, etc., while those unsuitable for carving include natural marble and glass. The metal raw materials suitable for engraving include copper, aluminum, mild steel with hardness less than hrc40, and those unsuitable for carving include quenched steel, etc

With the continuous emergence of various technologies in front of us, and CNC machining is one of them. We all know that it is a relatively common technology in the industry, and it is also a more common technology that we use. What is the precision detection of CNC machining?

CNC machinist CNC lathe for different shape of guide rail, each surface should control which plane straightness error?

In CNC machining, scraping and lapping method is used to trim the straight line of guide rail to pass the lost time. The method of grinding point is often used in the inspection of short guide rail. Because of the simple deformation when the leveling ruler exceeds 2000mm, it is difficult to manufacture and affects the measurement accuracy. When scraping and grinding the short guide rail.

The straightness error of guide rail is usually ensured by the accuracy of the leveling ruler, and the density of lapping points per unit area is also determined. According to the accuracy requirements in the middle of processing and the nature and important level of the guide rail in the middle of the processing, the rules are as follows: no less than 10 ~ 20 points per 25 mm × 25 mm internal lapping points (i.e. the number of points in each scraping Square).

The common shapes of CNC machining intermediate guide rail are rectangular guide rail and V-shaped guide rail. The degree surface of the rectangular guide controls the straightness error of the guide in the pen plane. The error of straightness in the degree plane is controlled by two or four sides of rectangular guide rail. For the V-shaped guide rail, the two inclined surfaces not only control the straightness error in the straight plane, but also control the straightness error in the degree plane.

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

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?

1. 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.
2. 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.
3. 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,
4. 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

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.