Toyota Motor Corporation's mold design and manufacturing technology has many unique features in management and technology. The preliminary discussion on the manufacturing technology of Toyota's molds will provide some reference and inspiration to domestic automotive molders who urgently need to improve their production methods, promote scientific management, and improve the level of manufacturing technology.
I. Overview of Toyota Mold Design and Manufacturing Department
Toyota Motor Corporation has two main departments related to the design and manufacture of stamping dies. Among them, the eighth production technology department is responsible for mold design, and the st department is responsible for mold manufacturing (st is the abbreviation of die). They all belong directly to the head office, production technology 1-8 department belongs to the production preparation department, and the die department (st department) belongs to the machine manufacturing department.
The 8th Production Technology Department is mainly responsible for mold design and press equipment preparation. It has a total of nearly 350 people including its planning, production preparation, and subordinate departments. There are three technical rooms related to the design of molds. They are divided by the type of product they are engaged in:
department
Responsibility
personnel
One room
Body peripheral part mold design
(door, cover, rear trunk lid) about 70 people
Two rooms
Main Body Parts Mold Design
(sides, fenders, roofs, etc.) about 75 people
Three rooms
Base plate, beam frame mold design
(floor, engine room, etc.) about 30 people
Each room is divided into two groups: stamping process and mold structure design. The specialized division of labor is a feature of Toyota's mold design department.
Mold design content breakdown
Toyota divided the mold design into three processes: process design, mold surface design, and structural design. The division of labor was clear, and specialized personnel were responsible for each. The process design mainly completes the process sketches, dl diagram design, detailed mold design task book, mold surface design, etc. The main creative work of the mold design is completed by the human brain in this step. The die surface design is almost a simple surface modeling, and the structural design focuses on the specific implementation of the die structure.
Personnel division of specialization
Each room is responsible for only one type of product, and each person is responsible for the same piece, even the same type of mold, within a certain period of time. Since Toyota can develop up to ten new cars each year, that is to say, some people may draw ten sets of very similar front door outer panel drawing molds within one year, and their degree of specialization can be imagined.
Mold's social division of labor
Japan's mold manufacturing division of expertise is very strong, although Toyota's own mold manufacturing capability is very strong, but it is not a model to do it. For example, he is responsible for the stamping process of all parts of the vehicle and the entire vehicle coordination of the mold. However, he only deals with the design and manufacture of the mold, and he only covers the inside and outside of the car body, and the floor and beam parts all go to the outsourcing manufacturers. This is not only true for Toyota, but also for mold factories affiliated with major foreign auto companies, such as Daihatsu's mold factory in Japan, and even only a limited number of external covers such as side panels, fenders, and top covers. This can be seen as a trend of development. In South Korea, Taiwan and even professional mold manufacturers are also developing more professionally with only a few parts.
Mold manufacturing department (st department)
The Toyota st. department is responsible for the coordination of mold making and new car molds, and it is up to the production of stamping production before mass production.
Department
responsibility
People/people
Technical Room
Production technology development, production plan
89
Nc class
Nc programming, inspection
175
Real class
Test tools, real manufacturing
142
Mechanical class
Machining
173
Locksmithing class
Fitter, assembly
237
Commissioning class
Test mode, debugging
204
Summary
1020
The main CNC processing equipment:
Device name
Number of stations/station
Structure machining CNC milling machine
39
High-speed, five-axis five-sided milling
15
New integrated processing equipment
6
Other small processing equipment
31
Summary
91
From the perspective of personnel and production capacity, the st department can be regarded as one of the largest automotive mold factories in the world.
Second, Toyota's mold design and manufacturing capabilities
Mold design and manufacturing capacity: approximately 10 car molds can be developed each year; mold production (standard sets) is about 2000 sets/year; internal control rate is 60% (outside of 40%)
Among the main products: 80% for dies, 7% for inspections, and 13% for others.
In the whole year, the mold manufacturing cost is estimated to be nearly 20 billion yen, the average mold output is 2 sets per year, the mold manufacturing cost (excluding design) is about 6 million yen per set, and the labor cost (average) is about 10,000 yen per hour. .
The vehicle mold design and manufacturing cycle lasts 12 months (from body design completion to mass production of new vehicles), including the entire vehicle design cycle of 5 months, manufacturing cycle of 5 months, and debugging cycle of 6 months.
It can be seen that Toyota's annual passenger car production capacity is about 5 million (approximately 50% in Japan), which is ten times the production of cars in mainland China, and the mold design and manufacturing capacity is also several times that of our country's automotive mold production capacity. . Toyota's complete vehicle mold manufacturing cycle is far shorter than our general single-set mold manufacturing cycle. Its standard single-set mold manufacturing cycle is three to four months. It seems to us a dream, our mold quality level and Toyota is far behind.
Toyota standardizes the manufacturing plan for molds. According to the complexity of molds, it can be divided into short cycle, standard cycle, and long cycle. Now take a single set of mold design and manufacturing cycle (drawing die, standard cycle) as an example:
Stamping
20
Mold design
20
NC programming
8
Real production
7
Foundry
12
Machining
9
Fitter assembly
7
A single set of drawing die has a total cycle of 62 days, of which the manufacturing cycle is 52 days.
The above cycle includes the design and manufacture of the mold until the initial mold test of the mold is completed. If you consider the total cycle time of each sequential mold of product parts, the total cycle time of each sequential mold of a single part shall be based on the drawing die for an additional 22 days (including mold debugging, but does not include vehicle commissioning) for a total of 84 days .
The above days are all weekdays (except holidays), and conversion to calendar days is approximately 20 days equals one month, that is, a single set of mold manufacturing cycle of three to four months.
Toyota's mold manufacturing is also conducted in accordance with the punctual production method. All the inversion plans are planned for every working day without early production and avoid increasing the production of molds. Our inversion plans are often for the duration of the project, man-made compression period. Toyota's plan for reversed stockpiles is to produce the necessary products when necessary, avoiding the waste of overproduction caused by early production.
Third, Toyota mold manufacturing technology
In the past ten years, I have conducted more in-depth studies and inspections at a number of mold manufacturing plants in Japan. The accumulated time has reached more than six months. In comparison, we discovered that Toyota's mold technology is also very prominent in Japan's mold manufacturers. No matter whether it is competence, efficiency or technology, it is not a world-class level. Through the understanding of Toyota, we can see that the world's automotive mold manufacturing technology is developing in these directions: the operation before the computer gradually replaces the on-site operation, high-precision machining replaces the manual labor of people, and the design and manufacture of molds are highly standardized. The production method is developed to an assembly line production method. In combination with our domestic mold manufacturing situation, Toyota is very different from us in the following places, and it is worth learning from us.
Fine mold design
We often say that the mold design is actually divided into three parts: stamping process design, mold surface design and structural design. The content and emphasis of these three designs are completely different. Toyota's workflow is to design the first stamping process and then to guide the mold surface design and mold structure design. They are done by different people, and the professional division of labor is very clear. The traditional stamping process design adopts the process diagram or dl diagram. The design of its die surface is very rough. The process modeling under the guidance of such drawings must be artificially finished and the manufacturing process must be supplemented in the subsequent order, resulting in the manufacture of the mold. Manual pliers have a large amount of work and an extended period. In the design phase, Toyota completed the fine design of the mold surface through the computer's surface modeling. For example, different drawbeads are designed for different feed amounts, different drawbead cross-sections for different parts of the same mold, anti-rebound, over-stretch treatment, minimum material design, and uneven clearance design. The result of the fine die surface design can greatly reduce the profile processing, reduce the clamp repair, and reduce the trial time, its role is no small matter.
In contrast, the domestic mold design still stays at the stage of structural design. The mold surface design is not well valued. The mold surface is actually completed by the day after tomorrow. The backwardness of the mold design has caused the backwardness of manufacturing. It is no surprise. .
Sheet forming analysis technology application
From 5-6 years ago, Toyota began to apply the finite element method to computer simulation of sheet metal forming analysis. The main application of the solution software was the American dyna3d. After nearly three years of hard work, they reached the practical level. At present, Toyota has established a database of analysis results for various typical parts of the entire vehicle body. For parts of a new model, if the formability does not change much, only the reference to the original process will not be analyzed. Only special new shapes will be used for sheet metal forming analysis. Toyota's new car to do prototype, in addition to the special shape of the sheet metal forming analysis, but also generally do simple mode to verify. Therefore, Toyota believes that the current analysis of sheet metal forming is not a necessary and simple matter, and it is costly both in terms of cycle and cost.
I believe that Toyota has developed a large number of models, with few changes between models, similar to many, and has accumulated a wealth of human experience, sheet metal forming analysis does not have much use, the establishment of a library of analysis results is a good Method (Japan Fuji Mould Co., Ltd. does the same). Looking back at the domestic situation, on the one hand, the mold division has a very low professional division of labor, and various parts will be encountered. Difficult to have ready-made experience, it seems that sheet metal forming technology is more necessary. On the other hand, the low level of technology to support the poor environment (such as: sheet parameters, friction coefficient, etc. difficult to grasp), mold factory application, to achieve practical (no effect, no cost of the study is not) is also very difficult. Even if a professional analysis company is established, the number of users, cycle time, price, etc., may be high. At present, the practical application of this technology in China is still difficult to determine.
Mold surface design experience accumulation mechanism
In addition to manual drafting sketches, Toyota's design department has completely computerized the design. In addition to a workstation, the general designer has a laptop. However, the true creative design still depends on the human brain, especially the accumulation of human experience. Toyota places special emphasis on the experience accumulation mechanism: only collective experience cannot have personal experience only, such as unified management of data, group discussion of sketch design, multi-sector collective review of drawings, and frequent changes in design standards and specifications. . The experience accumulation mechanism is the main means by which Toyota can continuously improve the fine design of the die surface. For example: After mold processing is completed, the general mold surface does not need to be combined, the edge does not have to be in the gap, the fitter is only responsible for the installation, the mold can not be adjusted in the initial test mode, the debugging mold has the mold surface design personnel presence, the initial test mode Defects need to be recorded. The results of the final rest, such as the drawbeads, the change in the radius of the drawing, the asymmetry of the symmetry, etc., are also measured on site. Accumulation, organization, analysis, and archiving of these materials are cumulative experiences in the design of die surfaces, and are added to the next design at any time.
Toyota's mold design and debugging process is truly a closed-loop manufacturing system. With this self-perfecting experience-accumulating mechanism, the mold design has become more and more precise and accurate.
Gap diagram design
In Toyota, the die surface design is actually completed by the two parts of the surface modeling and the nc programming. In order to convey and describe the design concept of the die surface, the third kind of diagram besides the dl diagram and the die diagram is created. The map is also called a quality assurance map.
The gap map itself has not been seen before, and this may be a Toyota creation. The design of the mold is not simply to design a machine, it can complete its certain actions (this can only be called structural design), the ultimate goal of the mold design is to ensure that the product parts it presses are qualified and high quality. The gap diagram is such a graph designed to ensure the quality of the product. The quality assurance diagram mainly includes such items as the actual mold surface area of ​​the mold, the clearance value of each character area, the change of the mold surface required by the process, the change of the drawing fillet, and the hollowing out of various mold surfaces. Wait. Any surface design that can't be achieved through surface modeling is communicated through the gap diagram, and is realized through the design of nc programming. Here, nc programming is no longer a simple process to realize the mold structure, it actually participates in the mold surface. Design came. Therefore, the application of the gap diagram is also an inevitable result of the fine die design.
The impact of mass production on the mold
Toyota's production scale is world-class, and it has extensive experience in how mold design meets the requirements of large-scale production.
Improve material utilization: For high-volume automotive production, improving the utilization of sheet metal is the first major event in mold design. As long as the material utilization rate is increased by a few percentage points, the cost of the mold can be slightly reduced. If a set of mold 400,000 yuan, equivalent to the price of 100 tons of steel plate, with life expectancy of 500,000, the average savings of 0.2kg of steel plate per piece, it is sufficient to save the cost of this set of mold.
Reducing the stamping process: The trend of mold design is to combine the parts, close the left and right parts, close the front and back parts, and so on. The original parts are combined into one piece, and the different pieces are combined in a set of molds. The number of single-piece processes has been greatly reduced, and the number of vehicle molds has become less and less. This has played a key role in reducing the cost of stamping. For example, Toyota reduced the mold factor of finished vehicle parts from about 3 in the past to about 2 in the past.
Press automation: In order to fully automate the press line, the mold must take into account the loading on the robot, the automatic discharge of waste, and the universal use of pneumatic, automatic, and sensing devices.
Rapid die change: Die change time for stamping lines has also become a must for mold design considerations. For example, the drawing die completely replaces the double action with a single action, the die is automatically clamped, the die changer does not change the air supply top bar, and so on.
Fourth, the mold structure design and processing
The design has two purposes: one is for the design itself and the other is for manufacturing. Designers gradually improve their design ideas in the drawing process. After the drawing is finished, they are also clear. Therefore, the drawings must first of all be easy for designers to see and make the design work more efficient. On the other hand, design must be oriented toward manufacturing, with the ultimate goal of improving production efficiency.
We should recognize that different production processes determine the presentation of drawings. The traditional mold assembly drawing plus part drawing form adapts to the non-frame structural mold production. After large-scale CNC milling, the mold assembly diagram becomes a better form. After full-scale application of cad design, if the production method has not changed, then the two-dimensional design and the general plan design will not change, but instead replace the drawing board with the screen and keyboard. Our company once changed the two-dimensional design into a three-dimensional solid design in 1997. However, the effect was not good, the design efficiency was reduced, and there was not much benefit in production.
Toyota provided us with relatively successful experience in the close cooperation between CAD three-dimensional solid design and manufacturing.
1. Physical design
Toyota's mold design has all adopted three-dimensional solid design, and the application software is enginner.
Die Surface Design and Structural Design Separation: Toyota completely separates the die structure design from the die surface design. The former is a physical design and the latter is still a curved surface design. In the structural design, the mold surface part is only schematic and can be used for real-type machining and cannot be used for mold processing. This division of labor greatly simplifies the physical design of the mold. This simplification is very important for the success or failure of three-dimensional solid design.
Canceling 2D drawings: Dimensions account for approximately 40% of the drawing workload. Toyota does not draw 2D drawings in the traditional sense and it completely eliminates the workload of this part. Instead, according to the needs of each process, necessary three-dimensional diagrams are given, and plane diagrams with the necessary dimensions are given. If we start from the three-dimensional design and eventually get the results of the two-dimensional map, then converting a three-dimensional entity into a two-dimensional map that meets people's habit of looking at the map will be very time-consuming and costly, and the designed entity will become worthless. Obviously contrary to the original intention of the physical design, Toyota's success is not to do so.
Building Blocks and Editing Design: The three-dimensional solid design adopts a building block design and relies on three-dimensional standard parts and a typical structure library to greatly standardize the mold structure and transform the two-dimensional drawing into a three-dimensional arrangement. At the same time, a large number of existing similar mold structures were borrowed, and after simple editing and modification, new mold designs were completed. For designers, this is a revolution in ideas. If we still stick to the rules, we first draw a floor plan and re-establish the body shape. The advantage of three-dimensional design becomes a burden and the efficiency is too low.
Interference checking: In the two-dimensional design, the designer often does not really establish a three-dimensional mold image, and can only rely on cross-sectional drawings for complex space problems. Once inexperienced and poorly considered, spatial interference is inevitable. The most direct benefit of 3D solid design is the very intuitive and convenient interference check, and even motion interference analysis. In the past, a difficult problem in the design of 2D maps was solved in the face of physical design.
The deletion of complex design is simplified: the physical design is directly oriented to manufacturing, and the complexity of its design is determined by the processing needs, and it is completely unnecessary to consider the habit of human viewing. For example: the chamfer of the casting, the concave angle in the processing by the tool to complete, the convex angle by artificial trimming, so the design does not have to do; Another example: standard parts, is completely purchased parts, can also become indicative in the design Simple geometry and more. There are many design tasks that are actually completed by the following process specifications, such as screw hole locations, insert shapes, and so on. The design is the most economical design due to the processing needs.
Semi-automatic design: Based on the physical design, Toyota has developed some auxiliary programs with certain functions, such as drawing die and other molds with typical structures and relatively high standardization, to achieve semi-automatic design. For example, the drawing die structure design is usually handed over to the novice and female staff. It takes no more than one week to design a complete set of modules.
2. Real-type numerical control processing
The first use of the physical design is that the casting foam is completely CNC-machined. The real model of Toyota is CNC machined with a whole piece of rectangular foam. The real-type numerical control processing production is through the process editing of the solid model (such as: processing surface mounting allowance, model layered editing, etc.), and then through numerical control programming, foam blank blank cutting, numerical control processing, manual bonding and Trimming and other processes completed. At Toyota, real-world production employees have completely changed from hand-made to large-scale NC programming. Simple manual bonding and finishing work at the site is performed by temporary workers. The real-type numerical control production benefits directly from the physical design, which in turn increases the precision of the casting, and brings great advantages to the subsequent fine processing.
3. Construction surface numerical control processing
The mold construction surface is a machined surface other than the mold surface, such as a guide surface, an insert mounting surface, a screw hole, and other processing surfaces. These are also programmed and CNC machined in Toyota. The physical design brings the possibility of CNC programming and machining of the die's construction surface. The programming of the construction surface can greatly improve the machining efficiency, reduce the human error in the field, and improve the degree of automation of the processing. Of course, to achieve this, in addition to the physical design, we must also do a lot of work, such as: automatic tool setting, tool management, processing parameters, programming experience, etc. In this regard, our gap with Toyota is even greater, without these foundations. It is impossible to program and process the surface.
Toyota's real cad/cam integration in the mold structure through physical design is also integrated. It eliminates the constraint of drawing two-dimensional maps, physical design shows its value, and both should be developed simultaneously. This is Toyota's experience for us.
V. High-precision processing
Die surface processing is the focus of mold processing. In recent years, Toyota has been making great efforts to develop high-precision mold surface processing technology, which has made people feel new and innovative results.
1. High-precision processing of profile
The high-precision machining of the profile is mainly reflected in such aspects as improving the precision of the die surface, improving the degree of machining in place, and achieving the fine design of the die surface. In addition to the precision of machine tools and the management of tools, high-precision machining is mainly achieved through the improvement of programming techniques.
Processing methods include contour processing, maximum length forward pass machining, finish machining pass travel density of up to 0.3mm, and changing vertical cutters to high-speed machining at 30 degrees to improve machining accuracy.
At the same time, in the concave corner clear roots, convex corners in place, control mold with unequal distance gap, the maximum possible reduction of profile surface should be processed in place to achieve the fine processing of mold surface.
2. High-precision machining of two-dimensional cutting edges
Toyota's two-dimensional cutting edge inserts are processed on a special insert processing line and processed into a single piece. The machining accuracy can be achieved by pin-positioning, and the clamping does not require clearance. When the two-dimensional cutting edge is integrally machined, on-line measurement method is also used to ensure the mold clearance of the male and female molds. The greatest advantage of the high precision of the two-dimensional cutting edge is that it can ensure that the trimming and burring of the workpiece is well controlled.
3. The effect of high-precision machining
Through high-precision machining, Toyota's mold accuracy has achieved the goal of fewer fitters and no fitters. In Toyota's standard plan, between the completion of machining and the first tryout, there are only seven fitter workdays. It is basically a fitter assembly time, and there is no fitter repair time. In Toyota, once the mold has been processed, basically no need to repair the fillet, do not open the gap, do not need to repair the root, not on the edge, do not study, or even draw the mold surface do not have to knife marks, do not push grinding, the only The caliper repair is to use whetstone to push and draw the protruding convex fillet and the compression drawing surface. And for the first tryout, the pass rate of the test piece that does not need to be modified reaches 80%. If you don't see it with your own eyes, this is the power of fine die design and high precision machining.
Sixth, other technologies
Mold material
Toyota's drawing die materials are mainly made of ductile cast iron rather than the current domestic popular alloy cast iron. The ductile iron has good welding performance, good machinability, wear resistance and surface quenching hardness, and the cost is much lower than that of alloy cast iron. For trimming edge materials, the use of profile inserts instead of cast steel is mainly due to the much higher cost of cast steel. What is most noteworthy is that Toyota has now adopted a large number of special cast iron materials with the integration of the base body and the cutting edge as the trimming mold, which greatly reduces the machining cost of the mold. Please note that the cutting edge here is neither surfacing nor steel. The entire edge of the cast iron is flame-quenched only on the surface, and it is used directly for the thin-plate trimming die for several hundred thousand lives. And the cost of this casting is not high.
2. Surface treatment
The surface treatment of Toyota's drawing model surface requires higher electroplating, and other molds, flanging, trimming edge inserts basically use flame quenching. Japan does not currently use ion nitriding technology. According to Toyota, there are also trials to consider. For long-life blade materials for heavy plates, Toyota uses its own patented special steel and is also flame-quenched. The first method of forming and then quenching the whole, due to the deformation caused by quenching can only be artificially trimmed, not seen in Toyota.
3. Inspection in mold production
The mold is a single piece of production, ensuring quality is a very difficult thing. Most of the domestic mold factories are equipped with a large number of professional quality inspection personnel, which seriously affects the production efficiency, but the quality control effect is still not good. How did Toyota do it?
Process inspection: Toyota believes that product quality is at the source, design, process, programming, machine tools, and cutting tools are the real guarantees for quality. Quality is produced rather than checked out. Therefore, there is no full-time inspection between the molds. Only self-inspection and mutual inspection, the quality of control is each producer.
Profile detection: The mold profile is also basically not measured. A large number of profile inspections, such as the measurement of the drawing radius, the correction of the drawbeads, the smoothness of the curved surface, etc., mainly accumulate experience for the design of the die surface, rather than checking the quality of the die.
Parts Inspection: Toyota's product parts inspections rely mainly on three-dimensional measuring machines for automatic numerical inspection, but they also do inspection tools, and inspection tools only serve as positioning support for product parts. Therefore, the structure of the test piece is simple, there is no forced clamping device, and the detection of their product is almost in the free state. This is a very strict requirement on the character of the product.
Seventh, technological development trends
A few years ago we saw that the auto mold industry in developed countries seems to be shrinking. Because at that time, mold production was inseparable from manual labor, developed countries had high wage costs, no one was willing to do this line, and other factors, the mold industry has shifted to the third world. Through the development of Toyota, we have some new understandings. The production of molds is increasingly dependent on high technology, and we can reduce the artificial labor to a very low level. The most important requirement for mold production in automobiles is high quality and short cycle. In large-scale automobile production, the cost of the mold itself is far less important than the cost of the mold. From this point of view, at present, our mold production does not have any advantage, and this industrial transfer will not become a trend. In the past ten years or more, we have achieved technological progress through the introduction of hardware technology. Efforts to pursue the new gap brought about by technological progress. From another point of view, if the automobile mold industry really shifts to the third world, it must be a sunset industry. At present, there is still a certain amount of development space and demand for car molds without a breakthrough in body materials.
Focus on the development of computer technology
The focus of Toyota's mold manufacturing technology development is to highlight the application of computers. More and more people are moving from the production site to the computer. Solid design plus numerical control programming replaces manual real-world production and machine operation. Fine die surface design and fine numerical control programming greatly reduce the clamp repair, and high-precision machining eliminates the research and repair of the die. Now CNC programmers have surpassed the on-site operation workers, and the man-hour cost of NC programming exceeds the processing time cost of the machine tool by 50%. The programming cycle exceeds the machining cycle. The development of computer technology application has not reduced the cost of the mold at present, but the production of the mold has changed from relying on the skill of the person to the automatic and semi-automatic production of the numerical control. This kind of high-precision and unmanned processing brings about the quality of the mold and the product parts. Greatly improved, the production cycle is greatly shortened, and computer technology has enabled mold manufacturing technology to reach a new height. In comparison, it can be seen that the domestic computer application is still relatively elementary, not that our machine tools and software are not available, but there is a big gap in the basic technology of the application, even if all of Toyota's technology is moved to the real world. It is not an easy task to achieve that effect.
Eliminate fitter
Originally we thought that it was impossible for the single-piece production and complex-shaped products of the mold to leave the handwork, and Toyota proposed to eliminate the fitter. The elimination of fitters is a goal. It is mainly to reduce or completely avoid grinding and adjusting fitters (assembly fitters are still required). As we mentioned earlier, Toyota’s current goal has been basically achieved. In addition to repairing and drawing and drawing convex fillets, grinding, repairing, and adjusting clamps are mostly abnormal or The defects of design and manufacture are no longer a necessary and normal job.
As an example, drawing the surface finish of the model has always been the quality standard that we have emphasized. In the past, this was mainly achieved by fitters. In order to reduce or not to mill, it is necessary to reduce the amount of milling cutter marks, it is advocated that the use of vertical surface machining five-axis milling machine, but also the use of CNC surface grinding. These Toyotas have also adopted, but the practice has proved that the cost of the five-axis machine tool is high, the efficiency is low, the programming is very difficult, and the effect is also very unsatisfactory. Finally, Toyota adopted a high-speed, small-transition three-axis milling method to obtain a high-precision surface, and artificially rubbed the fillet, while other models simply do not grind, mold surface with a knife mark. The results show that although the mold surface is not even smooth (it also has a knife mark), even if the surface quality of the car plate is very high, in addition to the internal surface of the product there are some pull marks, there is no external surface of the useful parts Any adverse effects are those that need to be plated, as well as knife-edge plating. It is said that some automobile mold factories in Germany and the United States have long since abolished the surface grinding. This is a big joke for those who are pursuing the surface finish of the mold. In the same way, the concave angle is used for clearing losses, the elevation is processed with a 30-degree head guard, and the gap is used to control the forming pressure of the parts. In this case, the precision of the convex and concave dies is now lost. significance.
Therefore, the elimination of fitters in a sense is no longer a dream. Of course, at home, how a mold factory persuades users to accept such a tool with a knife mark is still a big issue.
Integrated processing
There are three kinds of CNC machining lines on the Toyota machine shop site: The first one is a processing line composed of several CNC machine tools with interchangeable bed. One line includes bottom processing, horizontal milling, rough milling and fine milling. The machine tool has a clear division of labor and it is not necessary to reinstall the cards to change the machine tool. This assembly line is about the product of the 1980s. The second is an unmanned rubbing processing machine with a three-dimensional warehouse, which was the product of the early 1990s. The third is a rough finishing integrated, high-speed, high-precision, five-face machining center that has only been put into use in recent years. The first processing line, its stand-alone machine is the CNC machine tool currently used by us, but the machine tool is a multi-task machine. Its efficiency in not relocating the machine is high, and we basically stay at the level of stand-alone operations. It is worth our reference. Although the kneading machine group is very advanced, it is difficult to operate. It takes a lot of preparation and time. If there is not a large number of finishing tasks, it is not practical to use. It is also true of Toyota. It seems that this is not a success. The direction. The integrated machining center is the latest technology currently under development. Its advantage is that it combines the advantages of various machine tools. In addition to the bottom surface processing, it can be installed once in one time, with coarse, fine, and lying, high power, high precision, and high speed. Eighteen classes of martial arts are proficient and processing efficiency is high. The disadvantage is that the cost of the machine tool is very high, and the environmental requirements are also high. Is it economical to use it to work hard and live together? Still not known. However, this is undoubtedly a very idealistic technology that represents the development of CNC machining technology and should draw our attention.
Eight, summary
Toyota’s technology tells us that good molds should be designed; molds can also be streamlined; high-tech applications are the driving force for the development of mold manufacturing technologies; domestic auto mold industry still has a big gap compared to the world’s advanced level if we If you don't work hard, this gap will not shrink but will increase.
Through the above, we have simply listed some of the impressive things that Toyota has seen and those that are relatively strong in comparison with the domestic ones. They are not comprehensive and detailed, and we hope that these materials can give peers some thought.
We feel that our gap with the advanced world level is a great deal of pressure. In the face of the trend of world economic integration, if you are not the best in the world, you may not be able to live in China. Domestic auto mold manufacturers are not many, but they do not eat enough, our high-quality mold market is occupied by mold factories in neighboring countries and regions. We do not learn from the world's most advanced mold technology, can we survive?
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