Yearly Archive October 12, 2020

We all know that the components with mold forming technology have certain adaptability. It requires relatively thin parts and certain molding. It is difficult to use die stamping for components with thickness and diameter such as crankshaft and connecting rod. At present, the most can be used is to make the rough die of crankshaft first, and then use cutting to finish machining.

The advantage of using mold is that it can reduce cost, save time, improve production efficiency, so that enterprises can be invincible in the fierce competition. However, at present, the mold used in automobile manufacturing, or plastic components, lights, steel shell and other accessories. The real automobile core engine still uses cutting technology, not mold technology.

In addition to the engine can not use mold technology, the crankshaft used in the car can not use this technology. Why?

The technological level and scientific and technological content of mould production has become an important mark to weigh the level of science and technology and product manufacturing in a country. To a great extent, it determines the quality, efficiency, development ability of new products and the international competitiveness of a country’s manufacturing industry. According to the development of domestic and international mold market, mold expert Luo Baihui speculates that the mold precision will be higher and higher after the industry structure adjustment in China in the future. Die is the basic process equipment of industrial production. In the products of electronics, automobiles, motors, electrical appliances, meters, household appliances and communication, 80% – 90% of the parts and components are formed by the mold. The shape of the mold determines the shape of these products, and the processing quality and precision of the mold also determine the quality of these products.

With the improvement of economy and living standard, the number of cars is also rising. When we see so many cars, we can’t help but realize the huge production behind the manufacturers. Undoubtedly, China’s die and mold industry has led the development of the automobile industry. What is the impact of mold on automobile manufacturing and what requirements does the automobile manufacturing industry have on the mold industry.

The technological level and technological content of mold production have become the primary mark to weigh the technology and production level of a country. It determines the quality and efficiency of products, the development strength of new products and the international competitiveness of a country’s manufacturing industry to a great extent. According to the development of domestic and international mold market, mold experts speculate that the precision of China’s mold will be higher and higher after the adjustment of industry structure in the future. Mold is the basic process equipment of industrial production. In the products of electronics, automobiles, motors, electrical appliances, meters, household appliances and communications, 80% – 90% of the parts depend on the mold forming. The shape of the mold determines the appearance of these products, and the processing quality and precision of the mold also determine the quality of these products.

With the increasing of economy and survival, the number of cars is also rising. When we see so many cars, we can’t help but realize the huge production behind the scenes of the manufacturers. Undoubtedly, China’s mold industry has led the development of automobile industry. What kind of influence does the mold have on automobile production and what requests does the automobile manufacturing industry have for the mold industry.

The advantage of using mould is to reduce cost, save time, raise production efficiency, so that enterprises can be invincible in today’s fierce competition. However, the mold is now used in automobile production, or plastic components, lights, steel shell and other accessories. The real automobile heart mobilization machine still adopts cutting skills, never adopts mold skills.

Unless the mobilization machine can not adopt the mold technology, the crankshaft used in the automobile can not adopt this technology. Why? We all know that the components that adopt the molding techniques have certain habits. They require thin measurement and definite molding. For components with thickness and diameter, such as crankshaft and connecting rod, it is difficult to measure with die stamping. At present, the best way to adopt is to use die to make crankshaft rough embryo, and then to adopt cutting for finish machining.

When the machining precision is very high, the mold is often surplus but not enough force. The precision of today’s fine and fine molds is roughly in the range of 0.1-0.01 mm. Compared with the previous molds, the accuracy has been greatly increased. However, components like mobilizers require accuracy below one thousandth of a millimeter or less. Nowadays, it is not suitable to use the mould for machining.

Mold today’s own smoothness, roughness once had a great leap. However, the mold itself is also made by machine tools. If the accuracy of the machine tool used to make the mold itself cannot pass the standard, the precision of the products produced is bound to be low. Therefore, mold experts believe that the adoption of excellent mold skills is the inevitable trend of fierce competition, and it is more important to raise the mold’s personal competitiveness to get used to the market. It is the request of mold industry development and the heart of automobile and other industries to raise the high precision of mold.

Strengthen the recognition of die precision concept

1。 Die is a kind of fine forming tool used for batch forming, stamping and other products. Mold precision includes the accuracy of parts obtained in processing and the quality awareness of ensuring product precision when producing. But the mold precision usually refers to the precision of professional parts of mold.

①。 The concept of precision in mold processing refers to the actual geometric parameters after the mold parts are processed and assembled

Fixture design is a delicate work. Every detail should be taken into consideration. Otherwise, when assembling, we will find that this part is reversed, that part has forgotten to sink its head, it has been enlarged here, and it has forgotten to open a hole there, and the hole position is deviated.

Fixture design, unlike the general mechanical design, mold design. Computer gong processing general mechanical design cycle is very long, so there is time to check, draw 3D drawings to check the assembly and so on. Fixture design lead time is very short, slow is three days, fast and the next day to order. Due to the processing, assembly and so on, the time left for design is quite small.

Experienced fixture design engineer, the problems are generally more comprehensive. He will infer what problems will occur after the fixture is processed according to the problems or unsatisfactory places that have occurred before. In view of these problems and deficiencies, an improved countermeasure is made to make the function of the fixture more convenient and ideal.

Fixture design for fixture design engineers, is the test of experience, is the grasp of the structure.

It can be said that the success or failure of the fixture depends on 80% of the fixture designer’s design, and 20% of the fixture is determined by processing and assembly.

The imported products are generally from Germany, the United States and Japan. The brands include ingun, TCI, Xinhua, Huarong, Zhongtan, yatan, etc.

The quality of the test probe is mainly reflected in the material, coating, diameter accuracy of spring and sleeve and manufacturing process. At present, the processing of mechanical parts includes domestic products, and many of them are made of imported materials. Therefore, unless it is a shoddy process, the material problem of the probe is not very big. The diameter accuracy of the needle and sleeve in China is similar to that of Taiwan and Hong Kong products. The import is slightly better, but the general impact is not great. The quality of spring and coating processed by Dongguan Mechanical parts is much better than that of domestic products, The results show that the coating made in Hong Kong, Taiwan is slightly better than that in China. The main reason is that the coating made in China has poor wear resistance and the coating is easy to fall off.

If the test fixture is manufactured and used for more than 150000 times, it is more appropriate to select imported products, but the imported probes are more expensive. At present, the production level and technology in China are gradually improved, and in the current price war, many agents use domestic needles as imported or Taiwan made probes for sale.

If the test requirements and test times are not high, it is recommended to use domestic probes. The quality of the probe is mainly related to the test times and good contact in the manufacture of the test fixture. Design principle of fixture:

1. Meet the stability and reliability of workpiece positioning in the process of use.
2. Enough bearing or clamping strength is required to ensure the construction process of workpiece on the tooling and fixture.
3. Meet the simple and fast operation in the clamping process.
4. The vulnerable parts must be the structure that can be quickly replaced, and it is better not to use other tools when the conditions are sufficient.
5. Meet the reliability of repeated positioning of tooling and fixture in the process of adjustment or replacement.
6. Avoid complex structure and high cost as far as possible.
7. As far as possible, select the standard products with reliable quality in the market as the assembly parts.
8. Meet the safety laws and regulations of the country or region where the fixture is used.
9. The design scheme follows the priority principle of manual, pneumatic, hydraulic and servo.

Tooling and fixture processing, tooling and fixture design, tooling and fixture price consulting, tooling fixture technical consulting.

CT test fixture can effectively find all kinds of defects and faults in SMT assembly process, but it can not evaluate the performance of the whole PCB system at clock speed. The function test can test whether the whole system can achieve the design goal. It takes the unit under test on the circuit board as a functional body to provide input signal. Dongguan high-speed computer gong processing detects the output signal according to the design requirements of the functional body. This test is to ensure that the circuit board can work normally according to the design requirements. Dongguan CNC machining center so the simplest method of function test is to connect the special circuit board of an electronic equipment assembled to the appropriate circuit of the equipment, and then apply voltage. If the equipment works normally, it indicates that the circuit board is qualified. This method is simple and less investment, but it can’t diagnose fault automatically.

Hongze electronic equipment factory main products: assembly fixture, welding fixture, disassembly fixture, dispensing fixture, irradiation fixture, adjustment fixture, shear fixture, CT test fixture, FCT functional fixture, SMT furnace pass fixture, BGA test fixture and CCD test fixture, glass parts, ceramic parts, automation equipment, etc,

The exact definition of fixture is not found (and there is no need to investigate. It is enough to know what it is). I think it is an auxiliary device specially made for solving practical problems or realizing a certain function. Features: simple structure, wide range of applications, a wide range of types, can be a piece of iron, can also be a device. For example, grinding machine block can be called clamp fixture; for example, hi pot tester can be called fixture. (Note: the noun comes from Japan, we call it tool)

The electronic industry’s clamping fixture can be roughly classified into pressing, bending, cutting, riveting, welding, testing and fixing. Of course, it can also be divided into ordinary and special categories, which can be sorted out according to personal preference or professional secretary. Basically, in addition to electrical testing and welding, most factories have their own design department or simply make their own. It can be asserted that where there is an electronic factory, there will be clamping tools; where there is no electronic factory, there will be clamps everywhere.

In a sense, fixture design can exercise a person’s ability of abnormal analysis and problem solving, while the design ability is relatively complex, and equipment such as automata will be relatively weak and secondary. There are two reasons

1. The fixture design is simple, easy to use and safe, which is reflected in the structure and the workpiece. So, knowing how to do it, from drawing to assembly to debugging success, it hardly takes much effort. However, some of the objects of the fixture service are difficult products that can not be automated and manual operation is difficult. At this time, headache will often occur. If there is a problem that is not the problem of the machine itself, but if there is a lack of ability to analyze and identify and solve the problem, it will be confused and cheated, and will be made to sleep and eat uneasily, and the hair is like a hedgehog every day:)
2. In general, the most important consideration for fixture design is not the machine itself, but the product or process. No matter how you do it, the cost of each fixture is not different (the project cost is limited to death). Even if you spend more than 30000 yuan or 50000 yuan, the enterprise can accept it. If you have rich experience in product and process, you can always understand the opportunity and put forward improvement to the possible problems of the product before production At the same time, draw up a set of reasonable and efficient production plan, and then refine it to the production of fixture and fixture in each work station, which will guarantee the cost control and efficiency improvement in a long term, which is the most important part of the enterprise. There will be many solutions for the fixture of the same work station. Sometimes it is necessary to consider the product characteristics, production capacity requirements, cost control and other factors before finalizing. In fact, this process is more an analysis capability than a design capability.

Today, the development of mechanical technology has been very mature. Why we still encounter various difficult problems and why some technical problems are insurmountable are largely related to factors other than machinery which are developing faster and changing with each passing day.

Although the fixture is simple and easy to use, its design concept and level can basically reflect a person’s mechanical skills;

Of course, most of the designers do not dare to use 2D software, and most of them are afraid to use 3D software. Of course, most of the designers are afraid to use 2D software, and most of them are afraid to use 3D software. I personally think that for beginners, 3D design and 2D drawing is definitely an ideal way. Software such as Pro-E, SOLIDWORK, onespace, etc. is not too hard to learn, and the part used for fixture design can be easily learned. Three dimensional software has an advantage: it is more intuitive. People who can’t understand the drawings can operate and “touch” the drawings, which liberates the obstacles of reading and imagination in design. Similarly, good idea or design inspiration can be expressed quickly and clearly as long as you move the mouse and keyboard. The idea has been completely described. In fact, the design is half finished, including the highest half as far as possible. Of course, emphasizing the benefits of three-D design here is by no means a denial of 2D

The first step in fixture design is to understand the product. Deep understanding of the product, in fact, to do clamping fixture Baili no harm. If we grasp the products at the beginning, we can avoid detours and eliminate many possible problems in the future

The second step of design, of course, is the design concept. Everyone knows that the fixture is simple, but as mentioned above, it takes a lot of brains. There are a lot of things involved. What I think is the essence has been summed up in one sentence: accurate positioning, stable limit, easy taking and placing, less processing and skillful structure. Don’t look at these words, can be integrated cost, man-machine, organization and other related content, everyone may master and application level is not the same, but absolutely should be used. In the actual design, there are more things to use, such as cams, connecting rods, springs, cylinders, motors, bearings wait. There are also a lot to consider, such as whether the tool has strong interchangeability, whether the rack can support it, whether the clearance of the positioning groove is appropriate, and what to do in case of material jam To sum up, in fact, this step can be said to be the most demanding step, that is to say, the design with substantial significance.

The next step is to check while drawing. When it is almost finished, the drawing will be thrown out for processing. Then, when the workpiece comes back, it will be installed and tried. If there is any problem, it should be corrected as soon as possible, so as to avoid being too late. Then it is the sample stage. It may be very smooth or troublesome. It is necessary to think about it carefully. It’s better not to concern yourself and ask questions

Parts are the basic elements of a machine. The machine generally includes one or several transmission parts (such as electric motor, internal combustion engine, steam engine) used to receive external energy; the executive part (such as the cutting tool in the machine tool) that transfers the motion and power of the prime mover to the transmission part of the executive part (such as the gear and screw transmission mechanism in the machine tool) to ensure the coordinated work of all parts of the machine And control system (such as CNC system in machine tool) (that is, the machine is composed of prime mover part, transmission part, high-speed computer gong processing execution part, and measurement and control part). By further decomposing the machine, various parts can be obtained.

Parts are the basic elements of a machine, which can be divided into two categories: one is the parts that can be used in all kinds of machines (such as gears, shafts, etc.), which are called general parts; the other is the parts that can only be used in certain types of machines (such as bolt, propeller, etc.), which are called special parts; in addition, the parts combination composed of some cooperative parts is also called Is a component or assembly (e.g. coupling, reducer, etc.)

2、 Precision parts processing plant – strength requirements for parts:

Strength refers to the ability of parts not to break or produce plastic deformation beyond the allowable limit when working, which is the most basic requirement for normal operation and safe production of machines.

The principles and measures to improve the strength of the parts are as follows: 1) increase the size of the dangerous section of the parts, reasonably design the section shape to increase the inertia moment of the section by high-speed computer gong processing; 2) using high-strength materials, heat treatment to improve the strength and reduce the internal stress of the materials; 3) controlling the processing technology to reduce or eliminate the micro defects; 3) strive to reduce the load on the parts; 4) properly involve in the design And the structure of the parts to reduce the stress concentration.

Parts are the basic elements of a machine. The machine generally includes one or several transmission parts (such as electric motor, internal combustion engine, steam engine) used to receive external energy; the executive part (such as the cutting tool in the machine tool) that transfers the motion and power of the prime mover to the transmission part of the executive part (such as the gear and screw transmission mechanism in the machine tool) to ensure the coordinated work of all parts of the machine And control system (e.g. CNC system in machine tool) (i.e. the machine is composed of prime mover part, transmission part, executive part and measurement and control part). By further decomposing the machine, various parts can be obtained.

Parts are the basic elements of a machine, which can be divided into two categories: one is the parts that can be used in all kinds of machines (such as gears, shafts, etc.), which are called general parts; the other is the parts that can only be used in certain types of machines (such as bolt, propeller, etc.), which are called special parts; in addition, the parts combination composed of some cooperative parts is also called Is a component or assembly (e.g. coupling, reducer, etc.)

2、 Precision parts processing plant – strength requirements for parts:

Strength refers to the ability of parts not to break or produce plastic deformation beyond the allowable limit when working, which is the most basic requirement for normal operation and safe production of machines.

The principles and measures to improve the strength of parts are as follows: 1) increase the size of the dangerous section of the part, reasonably design the profile shape, and high-speed computer gong processing to increase the inertia moment of the section; 2) use high-strength materials, heat treatment to improve the strength and reduce the internal stress, control the processing technology to reduce or eliminate the micro defects, etc.; 3) strive to reduce the load on the parts; 4) properly handle the problem And the structure of the parts to reduce the stress concentration.

Generally speaking, the engraving machine is a kind of CNC milling machine with small cutting tools, high power and high-speed spindle motor. Foreign countries do not have the concept of precision carving machine. They mainly use machining centers (computer gongs) to mill molds. However, machining centers have their own shortcomings, especially when using small cutters to process small molds, and the cost is very high. At the beginning of China, there was only the concept of CNC engraving machine. The advantage of engraving machine is carving. If the hardness of processing material is relatively large, it will be unable to meet the requirements. The emergence of carving machine can be said to fill the gap between the two. The engraving machine can not only carve, but also mill. It is an efficient and high-precision CNC machine tool.

Shape and structure

The appearance and structure of the carving machine, engraving and milling machine and machining center (computer gong) are very similar. The following is a comparative analysis of the four:

Conceptually:

Processing center: Hong Kong, Taiwan, Guangdong area known as the computer gong, is a highly automated multi-functional CNC machine tool with tool magazine and automatic tool change device. The first machining center appeared in the United States in 1958. It can realize the centralized processing of milling, drilling, boring, reaming, tapping and other processes after the workpiece is clamped at one time, with special emphasis on “milling”.

Engraving machine: its spindle speed is high, suitable for small cutting tools processing, torque is relatively small, focusing on the “carving” function, such as wood (wood carving machine for special processing of wood), dual color board, acrylic plate and other plates with low hardness, which are not suitable for large workpieces with strong cutting. Dongguan Machinery parts processing at present, most of the products bearing the banner of engraving machine in the market are mainly for processing handicrafts with low cost. Due to the low precision, they are not suitable for mold development. However, there are also exceptions, such as wafer engraving machine.

Carving machine: as the name implies. On the basis of the engraving machine, the power of the spindle and servo motor is increased, and the bearing force of the bed is maintained. At the same time, the high speed of the spindle is maintained. More importantly, the precision is very high.

Engraving and milling machine: engraving and milling machine focus on carving and milling, which is a transitional model between the fine carving machine and the machining center. Compared with the precision carving machine, the advantages of computer gong processing are stronger machine rigidity, higher processing efficiency, high power, and suitable for fast and heavy cutting of soft metal. Compared with the machining center, the speed of processing soft metals such as copper and aluminum is faster, and the finishing speed and efficiency of steel mold are higher. Its disadvantages are not suitable for large-scale workpiece rough cutting, heavy cutting. Engraving and milling machine also to high-speed development, commonly known as high-speed machine, cutting ability is stronger, processing accuracy is very high, but also can directly process hardness above HRC60 materials, one-time molding.

In terms of appearance and volume:

The volume of the machining center is the largest, the volume of large-scale 1690 machine is 4 m * 3 m, and that of small-scale 850 type machine is 2.5 m * 2.5 m; the volume of fine carving machine is the second, and that of large-scale 750 type machine is 2.2 m * 2 m; the carving machine is the smallest.

In terms of mechanical structure:

Generally, the cantilever type is used in the machining center, and the gantry structure is commonly used in the carving machine and engraving machine. The gantry type is divided into the pillar type and the fixed beam type. At present, the fixed beam type is the main type of the fine carving machine.

In terms of index data:

The highest spindle speed (R / min): Machining Center 8000; engraving machine is the most common 240000, high-speed machine is the lowest 30000; engraving machine is generally the same as engraving and milling machine, the engraving machine used for high gloss processing can reach 80000, but the air bearing spindle is not the general electric spindle.

Spindle power: the machining center is the largest, ranging from several thousand watts to tens of kilowatts; the carving machine is the second, generally within ten kilowatts; the engraving machine is the smallest.

It is suitable for machining center, especially for rough machining.

Speed: due to the light weight of the engraving machine and engraving machine, their moving speed and feed speed are faster than that of the machining center, especially for the high-speed machine equipped with linear motor, the maximum moving speed is 120m / min

Accuracy: the accuracy of the three is similar.

From the processing size: the worktable area can better reflect this. The smallest worktable area (unit mm, the same below) of domestic processing center (computer gong) is 830 * 500 (850 machines); the largest worktable area of fine carving machine is 700 * 620 (750 machines), and the minimum is 450 * 450 (400 machines); engraving machines generally do not exceed 450 * 450, and the common ones are 45 * 270 (250 machines).

From the perspective of application objects: the machining center is used to complete the processing equipment of large milling amount of workpieces, large molds and materials with hardness comparison, which are also suitable for the opening of common molds; the precision carving machine is used to finish the finishing of small molds with small milling amount, which is suitable for copper and graphite processing; the low-end engraving machines are inclined to those with low hardness such as wood, double color plate and acrylic plate Plate processing, high-end suitable for wafer, metal shell polishing and polishing.

It is generally believed that: Machining Center, carving machine can do both products and molds, engraving machine can only do products.

Model difference

Let’s first clarify the differences between the three models

1. CNC milling and machining center is used to complete the processing equipment of large milling amount of workpieces
2. CNC engraving machine is used to finish small milling amount or soft metal processing equipment
3. High speed cutting machine is used to finish medium milling amount and reduce grinding amount to the minimum

In depth analysis of the above equipment structure can help us make the right choice

1、 — from a mechanical point of view

The machine is divided into two parts, the moving part