February 2021 – Page 3 – CNC Machining & Turning, Milling, Metal parts

Repetitive production of CNC lathe

CNC CNC lathe processing repeatability of production parts: the use of CNC grinder process preparation time occupies a higher proportion. For example Process analysis and preparation, programming, first part adjustment and trial cutting, etc., the sum of these comprehensive working hours is often tens to hundreds of times of the working hours of a single part, but these CNC lathe work contents can be saved and reused, so a part is successfully trial produced on the CNC grinder, and then put into production repeatedly, the production cycle is greatly reduced, the cost is also less, and better results can be achieved The economic benefit of the project is very good.

It is required that the CNC grinding machine can achieve high precision, high quality and high efficiency grinding under the control of computer. Compared with special grinding machine, it can save a lot of special process equipment, has strong flexible manufacturing capacity and obtains better economic benefits. Compared with ordinary grinding machine, it can eliminate many artificial interference factors in the long process of complex processing, and has good precision consistency and interchangeability of processing parts, and high processing efficiency.

The parts processed by CNC lathe should be able to give full play to the process characteristics of multi process centralized processing of CNC grinder. When CNC grinder processes parts, the situation of grinding workpiece with grinding wheel is exactly the same as that of corresponding non CNC grinder, but it can carry out some complex processing with machining accuracy requirements. For example, in the grinding range, ordinary grinder is mainly used for grinding cylindrical and circular CNC lathe In addition, it can also grind torus and complex combination surface of various forms.

The processing batch of the parts should be larger than that of the ordinary lathe to the batch CNC lathe. When the medium and small batch parts are processed by the non CNC grinder, due to various reasons, the pure cutting time only accounts for 10% – 30% of the actual working hours. When machining on the CNC grinding machine with multiple working procedures, such as grinding center, the proportion may rise to 70% – 80%, but the working hours for preparing to adjust are often much longer, so it will become uneconomic if the batch size of parts is too small.

CNC CNC lathe processing of some special parts to consider, there are some parts, although the processing batch is very small, ordinary lathe, but the shape is complex, high quality, good interchangeability, which can not meet the above requirements on non CNC grinder, can only be arranged to CNC grinder processing, such as parabola, cycloid cam and special surface mirror, etc.

CNC computer gong processing range

When the main surface of the parts with complex structure and shape and difficult to be processed by ordinary machine tools is composed of complex curves and curved surfaces, the computer gong processing needs multi coordinate linkage processing, which is difficult or even impossible to be completed on ordinary machine tools. The numerical control processing equipment is the most effective equipment for processing such parts. The common typical parts are cam, integral impeller and die.

① There are various kinds of curved disc cam, cylindrical cam, conical cam and end face cam. When machining, according to the complexity of the cam surface, three axis, four axis or five axis machining center can be selected.

② Integral impeller is commonly used in aero-engine compressor, air compressor, marine underwater propeller and so on. In addition to the characteristics of general curved surface machining, it also has many special machining difficulties, such as narrow channel, easy tool to curve with the machined surface and adjacent.

The CNC center of parts with both plane and hole system has automatic tool changing device. In one installation, it can complete the milling of the upper plane of parts and the multi-step machining of hole system, such as drilling, boring, reaming, milling and tapping. The processing part can be on one plane or on different planes. The pentahedron machining center can complete the machining of five surfaces except the clamping surface. Therefore, the parts with both plane and hole system are the preferred processing objects of computer gongs. The common parts include box parts and plate, sleeve and plate parts.

① There are plane, curved surface and hole system on the end face of parts, and some radial holes are often distributed in the radial direction. The vertical processing equipment should be selected for the disc, sleeve and plate parts whose processing parts are concentrated on a single end face, and the horizontal processing equipment should be selected for the parts whose processing parts are not on the same direction surface.

② Box parts are common box parts. Box parts generally need multi station hole system and plane processing, with high accuracy requirements, especially the shape accuracy and position accuracy. They usually need to go through milling, drilling, expanding, boring, reaming, countersinking, tapping and other steps, and need more tools. It is difficult to process on ordinary machine tools, and the number of tooling sets is large. It needs multiple clamping and alignment, and manual measurement times are many, so the accuracy is not easy Guarantee. The last installation of CNC machining center can complete 60% ～ 95% of the process content of ordinary machine tool, with good consistency of parts precision, stable quality and short production cycle.

CNC processing technology in mobile phone

First generation iPad let more people know CNC technology

The first generation iPad, released on January 28, 2010, quickly won the market. In addition to its high performance, the back shell process of CNC processing technology is also one of the highlights. Its color is still “high value” in its shape, which is liked by more consumers. It can be said that the adoption of iPad generation CNC technology will let more people know about the technology.

The first generation iPad sold high-precision and high complexity polishing CNC process back shell, which is a lot of “bonus”. The first generation iPad was initially applied to the fuselage thickness of 13.4mm, and the first generation iPad fuselage thickness of 13.4mm. CNC molding technology combined with magnesium alloy material back shell brings a strong metal texture to the product. Although from our current perspective, the thickness of the fuselage is somewhat unsatisfactory, but in terms of the background at that time, its technology has just been applied to flat products, it is not easy to achieve this.

The thickness of the first generation iPad is 13.4mm, and its technology is not so perfect. It focuses more on the appearance and interior without too much design. At the beginning of the design, the main focus of the iPad generation CNC back shell is the appearance. When holding, the body is smooth, but there is just the right grain feeling, which makes it feel better when playing with the product. In addition, the round corners around the back shell increase its portability and give people a great visual experience.

In terms of internal design, the internal performance of the first generation iPad back shell is relatively rough, the internal screw fixation method and “baffle” design are relatively abrupt, and the overall design of the back shell is poor. However, the existence of its stripe design can better provide space for components and ensure the performance of the product. The thickened design at the key position of the back shell can ensure the fixation of its function keys to a certain extent.

In addition, the internal screw fixation method and “baffle” design of the iPad with CNC process are relatively abrupt. It can be seen that the preliminary CNC process applied to the flat products is relatively rough, and there are still many areas for improvement in the internal design. However, the strict product precision and outstanding texture make the process superior to the injection molding and stamping molding processes. Of course, this is only the initial CNC process. What progress has this process made? Let’s go on.

CNC processing technology tends to be mature. Both Nokia N1 and iPad air2 adopt this technology. With the development of CNC technology, more and more tablet products are applied. The most representative ones are Apple’s latest series of tablet iPad air2 and Nokia N1 tablet computer. The back case of these two products adopts CNC technology. What are the improvements in technology and design?

Nokia N1 adopts the latest CNC process back shell, which makes the appearance more beautiful. In appearance, the products made by this process are more “slim”. The back shell gives people an overall sense of visual impact, and the appearance of the products becomes more exquisite (of course, this has a lot to do with the upgrading and improvement of the screen). The borders around the products become more rounded, which is not a rigid “frame” design, It’s more comfortable to hold it in hand. This change can be said to be a big improvement in technology.

The Nokia N1’s peripheral borders become more rounded, rather than rigid “frame” design. In addition, there are certain improvements in the details of the key position, so that the key position does not stay on the side border, but to a certain extent close to the backplane. In this way, the thickness of the body will not affect the user’s operation, which can be said to kill two birds with one stone. The realization of the design, to a certain extent, also depends on the improvement of the process.

The details of the key position have also been improved, which is easy to operate and more beautiful at the same time. The concave design of the interface has also been improved in the previous technology. There is a certain gap between the two key positions. The design makes the volume key position and the shutdown key position adjacent, which makes the side of the machine more beautiful.

The precision of CNC technology perfectly supports the design. We can see that the appearance of today’s CNC technology has been greatly improved compared with before. The round frame, the appearance is more refined, and the polishing process is more mature. The high-precision polished fuselage will have a kind of aesthetic feeling of industrial design. And these are only the improvement of appearance technology, so does the internal technology of back shell also have a qualitative improvement? Please go on to see.

The design is more reasonable while the interior design is beautiful. Compared with the exterior of the back shell, the improvement of the interior of the CNC back shell is more attractive to the author. Now the interior of the CNC back shell has become “clean” and the screw fixing place has become “small”. The position is close to the frame, which does not give people a sudden feeling of design. The overall design has been greatly improved.

How to operate computer gong processing

Generally, the workpiece processed by computer gong has complex shape, many processes, and many kinds of cutting tools. It is often necessary to complete the whole process from rough machining, semi finish machining to finish machining after one clamping. So the program is complicated. The following problems should be considered when programming.

Carefully analyze the drawings and determine the reasonable process route.
The size of the tool should be selected, and the measured actual size should be filled in the tool card.
Determine the reasonable cutting parameters. It mainly includes spindle speed, back feed, feed speed, etc.
There should be enough space for automatic tool change to avoid collision with workpiece or fixture. It is recommended to set the tool change position at the origin of the machine tool.
In order to check and debug the program, the processing contents of each step can be arranged in different subprograms, and the main program mainly completes tool change and subroutine call. This procedure is simple and clear.
Check and trial run the programmed program, and pay attention to whether there is interference among tools, fixtures or workpieces. When checking m, s and t functions, it can be carried out in the z-axis locking state.

Performance of computer gong deep hole drilling machine

The deep hole drilling machine with computer gong is different from the traditional way of hole processing. It mainly relies on specific drilling technology (such as gun drill, BTA drill, jet suction drill, etc.), and the special machine tools for drilling deep hole series and precision shallow holes with length diameter ratio greater than 10 are collectively referred to as deep hole drilling machine.

Deep hole drilling machine has the following five characteristics in practical application

The casting of the whole machine is made of high quality mihanna cast iron, which has been aged to make the casting structure uniform and stable, with high rigidity and good stability.
The 3-axis deep hole drilling machine adopts imported high rigidity, high speed CNC to process high-precision screw rod, which can provide more powerful torque and more durable during processing.
The high-quality servo motor and driver are used for the three-dimensional feed drive, and they are directly connected with the ball screw. The mechanical parts are processed, and the transmission is stable without back clearance. At the same time, its good rigidity and optimized shock absorption performance greatly improve the dynamic rigidity of the transmission system, and can realize rapid movement.
The spindle adopts powerful motor, which can meet the needs of high and low speed processing. CNC processing and automatic oil cooling system ensure the constant temperature during processing.
The operating system adopts Taiwan system, which can be compatible with CAD / CAM software

Processing and development of precision mould

Research on key technology of design and manufacture of continuous fine blanking die for complex parts

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, the precision forging must be too thin. They are closely related. The basic idea of developing precision forging and fine blanking compound 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 has a high level, so it is a good way to improve the overall level of precision blanking technology in China.