Industrial machine is the “equipment of production equipment”, providing intelligent production equipment and parts for the equipment manufacturing industry, is one of the most important tools in industrial production, and is in the cornerstone position in the entire industrial system.

In 2020, the global machine tool output value is less than 500 billion yuan, a decline of 16.3%. For many years, China has been the world’s largest producer and consumer. However, China’s machine tool industry is still facing problems such as weak basic ability, high import dependence, and difficult to gather talents.

01 China’s machine tool industry is facing difficulties

GFD233A-3BHE022294R0103 Since the late 1990s, China’s original machine tool industry research and development system has collapsed, and a new market-oriented research and development system has not been established.

In the upstream design and manufacturing end, the foundation is weak in materials, parts and experience, which is difficult to support China’s comprehensive autonomy in the field of high-end machine tools; In the downstream application end, leaving the imported raw materials, high-end machine tools have no use in our country.

Only taking materials as an example, China’s basic material homogeneity, cutting performance and other indicators relative to foreign countries have a big gap, not only high-end tools rely on imports, a large number of downstream applications of high-end materials are also heavily dependent on imports.

GFD233A-3BHE022294R0103 With the development of the national economy and the upgrading of the industrial structure, the application of high-end CNC machine tools is becoming more and more popular, and the demand for products is increasing, but the supply is difficult to meet the demand. The added value of low-end product trade is low, and the transition to high-end is urgent. Data show that in 2018, China’s high-end CNC machine tools, such as five-axis and above machining centers, have a self-sufficiency rate of less than 10%, of which gantry machining centers and vertical machining centers have a self-sufficiency rate of less than 1%.

In the high-end field, China’s machine tool enterprises for some high-end industry demand is difficult to touch, even dare not touch. In the mid-end field, Japanese machine tools firmly occupy the mid-end market with their reliable and durable performance and cheaper prices. Taking horizontal machining centers as an example, Japanese companies such as Mori Seiki, Yamazaki Mazak, and Okuma occupy more than 80% of the market in China. In the low-end field, a large number of small and medium-sized private machine tool enterprises gathered in Tengzhou, Shandong (the capital of small and medium-sized machine tools in China), Yuhuan, Zhejiang (the capital of economic CNC lathes in China) and other places, into the low-end scramble.

GFD233A-3BHE022294R0103 Machine tool industry is a high technical threshold, high professional division of labor and the need for long-term accumulation of typical. Machine tool industry progress driven by capital alone is difficult to succeed, the need is a market-oriented mechanism. It is estimated that the market capacity of the machine tool is only equivalent to 2.5% of the market capacity of its production object, and the real data is probably less than 1%. Machine tools are fundamentally different from equipment manufacturing such as high-speed rail and nuclear power equipment: the machine tool industry is fully market-oriented, and the national will can maintain the operation of a few key enterprises at most, but it cannot play a decisive role.

02 Where’s the neck card

At present, the core “card neck” products of China’s machine tool industry are high-end CNC machine tools.

1. Machining accuracy

GFD233A-3BHE022294R0103 Machine tool is a complex electromechanical information system, which is affected by statics, dynamics, vibration and heat during machining. Only take the internal thermal effect as an example, it includes tens or even hundreds of factors such as motor rotation cutting magnetic induction line heat generation, lead screw guide rail motion friction heat generation, cutting process heat generation, and the generated heat will cause parts heat deformation, resulting in changes in tool and material performance, and ultimately superposition reflected in the processing error.

Europe has been able to establish the corresponding physical model in this respect, can simulate and analyze the source of processing error through high-precision simulation, and compensate, and improve the processing accuracy, but at present, Chinese enterprises even have no solid basic research on the heat source of the motor rotary cutting magnetic induction line heat source.

2. Reliability

GFD233A-3BHE022294R0103 German de Maggie (DMG) company has a strict quality control system for its machine tools, and the company’s allowed repair rate has been as low as 1.8 times/(thousand sets/year) a few years ago, which is at least one order of magnitude lower than the current domestic repair rate.

The reliability of the machine tool is mainly divided into three aspects, which are static characteristics, dynamic characteristics and thermal characteristics, and the cutting performance of the machine tool mainly depends on the dynamic characteristics. It is this dynamic characteristic that is almost ignored by the domestic machine tool industry.

The root cause of this seemingly “negligence” is actually the lack of research on the basic mechanism in China, and the insufficient accumulation of engineering databases on the characteristics of machine tools, so that these size models can not be correctly calibrated. Engineering experience is insufficient, and there is no industry common technology support.

3. Sensor technology

GFD233A-3BHE022294R0103 Effective and complete control system is the premise of machine tool to achieve high machining accuracy and intelligence, and perfect and reasonable sensor system is the core hardware foundation of the control system.

Taking the DMC80FDduoBLOCK, a five-axis milling center currently on the market, as an example, a machine tool is equipped with more than 60 sensors at key locations, including temperature, force, vibration, lubrication flow, coolant temperature, etc. Through the sensor, the required machine tool and processing information can be collected accurately and in real time, and the online correction compensation can be completed in time through the appropriate control method.

Step 4 Be smart

Intelligence is a complete process to realize the machine tool “self-learning, self-adaptation, self-diagnosis” and even “self-decision-making”. At present, European machine tools have a high level of intelligence, taking De Magee’s CELOS as an example. At present, this machine has been able to greatly optimize human-computer interaction, the function of the machine tool block, developed into an app-like function, the user can more easily and quickly process programming operations on the panel.

In addition, CELOS has realized the high-precision simulation of the machining process, and the machining center can first directly visualize the machining process through modeling and simulation after receiving the machining instruction program segment, and present it to the operator of the industrial machine tool.

The core of machine tool intelligence is the need on the basis of a perfect sensor system, superimposed with big data, artificial intelligence and other methods, to achieve the automatic optimization of the processing process, parameters, paths, speed curves, early warning of possible conflicts, internal and external interference factors to make correction compensation, to ensure accuracy and other functions.