Application of stamping die technology in China's

Stamping is one of the four major processes in automotive manufacturing. The manufacturing accuracy of the body depends to a large extent on the accuracy of the stamping and its assembly. Stamping technology stems from the development and needs of mass production, especially in the automotive industry, and it is still the case today.

The development status of China's automobile stamping technology is reflected in the following aspects.

External cover is more automated

The outer cover has high surface quality requirements and can only rely on automated production. Although the automatic production of automobile outer cover parts in China is not high-speed stamping, the degree of automation is also quite high. This is mainly reflected in the widespread adoption of automated line stamping.

Line stamping generally consists of 4 presses to form a complete closed press line. The middle is the automatic feeding and picking of the robot. The production cycle is about 10~15 times/min. The typical one is the first double action 1630T and the subsequent 800T. The press consists of.

Floor or top cover inner cover for automatic or semi-automatic production

Such parts are mainly determined by batch production methods, generally using automated or semi-automated production. In addition to the joint venture company, the initial start of the local enterprise is basically a semi-automatic stamping production method.

Semi-automated stamping places specific requirements on the press. First, the press table should be large; secondly, because the forming force is too large, the first press is 2000T or 2400T, and the subsequent press is 1000T or 1250T or more.

2. The chassis frame parts are mostly made by component companies.

The chassis frame parts are mostly manufactured by the parts company and sent to the OEM. Large-scale parts companies generally have 6 press lines. Considering the convenience of quality control and production logistics management of the main engine factory, such parts companies have welding or even subsequent paint or spraying processes, so that they can directly provide total to the OEM. Into the parts.

Precision stamping technology is developing rapidly

Precision stamping technology originated in Switzerland with the development of watchmaking industry. It is one of the key technologies in the development of the automobile industry. It has important applications in the manufacture of some automobile assemblies, such as door hinge assembly and glass lifter assembly. The thickness of such parts is 3-5mm, which requires high precision, good strength and smooth and reliable assembly movement.

After years of development, precision stamping technology has made gratifying achievements in China's automobile industry. At present, a number of powerful fine-punching enterprises have emerged in China.

Development and application of main stamping process and hydroforming technology

At present, the mainstream stamping process in China is still a linear mold production mode. As for special forming processes, such as hydroforming, we often hear similar introductions and reports, but at present we mainly stay in the laboratory.

The hydraulic forming technology in the industry is mainly used in the forming of tubular parts, while the foreign countries are mainly used in the manufacture of individualized automobile parts in a small batch. At present, there is still no application in the domestic formation of the cover.

Hydroforming has the outstanding advantages: Firstly, in principle, the technology is isostatic forming, which relies on high-pressure medium to change the shape of the sheet. The sheet is pressed in the normal direction and is in a three-way state. The improvement of local forming, or the formation of more complicated covering parts; secondly, its forming principle and liquid medium change the traditional steel-steel contact forming method, which can effectively reduce sheet scratching and is highly beneficial for improving surface quality. Thirdly, it has improved the limitation of traditional stamping on the direction of stamping. Fourthly, more process content can be formed at one time, which is beneficial to reduce the number of processes and molds. Fifth, cold work hardening in forming is beneficial to improve the strength of the workpiece. At the same time, from the current foreign application situation, its production cycle is not slow.

However, hydroforming technology also has shortcomings. The limitations of its application are obvious: external liquid media and its corresponding equipment are required; and it is necessary to carry out subsequent processing of the parts before welding; considering the influence on the on-site working environment, it is not suitable for high-volume parts processing.

Problems in the manufacture of domestic automotive panel moulds

There are internal and external parts of the automobile cover, and accordingly there are also parts of the inner and outer cover parts. The surface quality of the inner cover is mainly the rebound and distortion problem. The stability and reliability of the mold are mainly to prevent the strain and improve the warpage and deformation of the workpiece; the surface quality of the outer cover is mainly the scratches, the burrs of the holes and the edges, Partial depression, the quality of the bonding surface, the gap after assembly of the assembly, etc. The mold requires excellent working parts, accurate assembly, and smooth mold movement.

It should be said that China has full capacity and technology to manufacture a complete mid-level car body mold, but the mold is not mass-produced. No matter which mold factory is manufactured by any mold, it is ultimately the specific personnel who undertake the design and manufacturing tasks. carry out. We can do a lot of work on overall experience accumulation and standardization, but because it is a single piece of production, it is actually determined by the individual level.

At present, the inner cover moulds of domestic automakers are mainly produced in China, and some key outer cover moulds are outsourced. Outsourcing is based on foreign experience, and the contractor has greater expectations in terms of product manufacturing cycle and quality. In fact, there are many problems in the outsourcing of the mold, but for the contractor, psychologically, there are more domestic problems.

All in all, the automobile cover has a large outer shape, and adopts a line production method and uses a wire-forming mold; small and medium-sized stamping parts are generally used in a multi-station progressive die, and the efficiency is high. With the continuous development of the domestic automobile industry, China's automobile mold industry is also making progress, and the competitive advantage of foreign automobile mold factories will be gradually weakened. Everyone will eventually agree with domestic molds.

Automotive stamping die design is looking forward to improving CAD/CAE system integration technology

When it comes to automotive stamping technology, the design of automotive stamping dies cannot be ignored.

At present, the CAD/CAE system that is common in the market has changed a lot since 10 years ago. It used to be a more generalized system. At present, it has made a lot of adaptive development or transformation for mold manufacturing. This is undoubtedly huge. progress.

Some of the typical CAD/CAE systems on the market today are very powerful, but in practical applications, it is always difficult to achieve the desired results due to changes in the environment, or there are some unsatisfactory places. In the long run, from the perspective of cost reduction and service, it is better if there is a powerful domestic CAD/CAM system.

In the long run, the integration of CAD/CAE will become a demand or trend. In fact, there are many such attempts now, but it is not very satisfactory from the application effect.

It is necessary for CAD/CAE system developers to make some special combing, analysis and characterization of the design ideas of the cover mold, and then find a joint point from the perspective of the software system. What is better in this area is the Thinkdesign system, which is able to achieve the engineer's intent in rebound processing.

The integration between software systems is always moving forward, and there is no problem in physical network processing. Now some mold factories have realized CAD/CAM integration in PDM environment. However, from the perspective of the relationship between system development and industrial application of mold factory, there is no more mature experience for reference without industrial application. If the mold factory needs to be applied, it needs investment, and the investment needs income. At the same time, the cultivation of talents is also an unavoidable problem.

Requirements for machine tools and tools for automotive stamping die manufacturing

1. Requirements for machine tools

The requirements for equipment for automotive stamping die manufacturing are mainly reflected in stability and reliability.

The author recently went to a mold company that said the accuracy of the equipment remained very important when talking about the use of several of its equipment and a machining center that was just installed. At the same time, the staff pointed out that the current equipment is increasingly dependent on the skills and professionalism of the equipment installers. The equipment installers must install and debug the equipment to the best condition. When training the operators, it is important to emphasize the equipment. The main points of use and maintenance and the results.

Mold manufacturing enterprises have great expectations for equipment purchased by huge amounts of money, which requires all parties to work hard to achieve their intended goals and achieve win-win and harmony. It is even better if equipment manufacturers can regularly return to users and on-site services, and even carry out some overhaul services and renovations.

2. Requirements for the tool

The requirements of the tool, I have talked about, mainly have the following points:

1 quality. Quality is a prerequisite, and the quality requirements are endless. The total service life and one sharpening life are their metrics.

2 price. The more competitive the field, the greater the effect of price. The price/performance ratio is its measure.

3 Research and development capabilities. The ability to launch new products includes at least two aspects: First, the ability to respond to customer needs, users are afraid that tool suppliers will ignore their needs, such as product suppliers that customers do not need, but they are highly recommended. Providing a solution is confusing. But now there has been a big change in this area, we have seen some mature and targeted solutions; the second is the design and manufacturing capabilities of new products, which is a test of the technical manufacturing strength of suppliers.

Of course, not all of the customer's requirements are reasonable or feasible, but the supplier (including ourselves as a supplier to others) does have the obligation to carefully analyze the customer's needs and provide professional solutions based on the state of the art. Therefore, whether to provide professional or targeted technical solutions based on the current state of the art is a very important and realistic aspect to test the supplier's research and development capabilities.

4 delivery date. At present, reducing inventory has become a problem that all fully competitive industries must face, so shorter delivery times are particularly important. Being close to the customer to establish a reasonable inventory becomes a realistic solution, the closer it is, the faster it will be. Tool suppliers are no exception.