Grinding machine - the choice for high precision machining

As the automation of the process continues to heat up, in response to the ever-changing demands of the market, grinding machine manufacturers have begun to focus on the convergence of production, variety, and grinding machine manufacturing technology with automated processing, and how to use digital means to further improve the precision of the grinding machine.

Grinding machine automation

Harding China Co., Ltd. Product Manager for Grinding Machine Mr. Wang Xiaohui: At present, the degree of automation of grinding machines is getting higher and higher, and automation has become a hot spot for the future development of grinding machines. But in the process of pursuing automation, the first thing that should be clear is, what is the purpose of automation? The answer is nothing more than minimizing production costs while ensuring quality. Two main factors should be considered. The first is the machine tool itself, followed by the processing technology.

The degree of automation required for the machine itself is very high, and not all devices have these functions. The machine tool needs to have a modular design that can meet the needs of different users for flexible processing. In addition, the machine tool also needs to have a very high computing speed, and a very wide range of interfaces to enhance the matching with the automation system.

In addition, the processing technology is equally important for automated systems. What automation needs to realize is an unmanned operation. From feeding to processing, every step in the process needs to be detected manually in real time. If you do not achieve the desired goal, how to interfere with the machine tool to make adjustments? We divide this process into pre-process, in-process and post-process, ie before grinding, during grinding and after grinding. The purpose is to be able to produce stable and reliable production. Any problems in any one of the stages cannot realize the automation of machine tools. Processing.

At present, the automotive industry is the most demanding of high-volume production. Therefore, the degree of automation is also very high. For example, Jingzhou Henglong Company, the largest manufacturer of automotive power steering gears in China, produces about 10 to tens of thousands of pieces each year. The product they chose was a TSCHUDIN 3 in 1 grinder from HARTING Company. This machine is equipped with a feed and loading device, equipped with MARPOSS pre-grinding measuring device, on-line measuring device and post-grinding measuring device. The control of the entire production process is real Automated production, the original need to 3 times the processing of the assembly is completed as a set-up, while the processing cycle shortened by more than 5 times.

Mr. Wolfgang Haarer: We have been watching the strong demand for automated grinding machines. In the global market, especially the Chinese market, our customers' interest in such machine tools has been increasing. An important basic feature for any fully automated grinding machine is to have a digital control system. Digital control systems are the premise of automated grinding machines. We currently only manufacture grinding machines with numerical control systems. Of course, after the CNC system, it also needs other components, such as optimized software, and some accessories, such as measurement systems, trimming systems, and cooling systems. Although some parts are commercially available, we are responsible for the normal operation of the entire grinding machine.

We have a fully automated grinder Starline 2000 CNC for grinding punches. Composed of the machine itself and the automatic loading and unloading system, it can be operated unattended. Its high degree of automation is reflected in several aspects: automatic unmanned operation; automatic loading and unloading system, the robot automatically stores the workpiece in the warehouse can store one week of the workpiece; automatic measurement system, the workpiece can be measured before and after grinding; high Accuracy, high efficiency, low loss servo motor driven automatic trimming system. With automatic compensation.

Mr. Shu Zhiyong: In general, grinding is a Precision Machining that guarantees the final process size and precision in machining. This requires that the grinding machine has high manufacturing and assembly precision. However, the requirements for grinding machines in the modern manufacturing industry are not limited to this, but also require that the grinding machines have a high degree of automation, but if anyone asks what function of the grinding machine can be called an automatic grinding machine, because the grinding process is very different. I think that answering this question should not start with the function or equipment of the machine tool, but should start with the purpose of automation. The purpose is nothing more than four kinds: first, automation to reach the precision that cannot be achieved by artificial (or unskilled mechanic); secondly, automation to achieve The accuracy of the product cannot be achieved by manpower; thirdly, it is automated to achieve an efficiency that is difficult for humans to achieve; and fourth, automation reduces man-made settings, adjustments, and loading times.

Automation is not the purpose, digital control systems, automatic detection devices, automatic compensation systems, automatic loading and unloading, etc., shall be determined according to the product's processing technology, manufacturing precision and production efficiency. Due to the development of precision casting and forging processes, the production of civilian products, and the increasingly finer social division of labor, people's requirements for the automation of grinding machines will become higher and higher.

Equipped with high-end CNC grinding machine

Mr. Wang Xiaohui: The requirements for the numerical control system of grinding machines are very special. In a professional numerical control production plant, almost no CNC system can be found for the development of grinding machines. Grinding machines require that the CNC system be open-ended, or a PC-based CNC system. In the actual grinding process, the grinding parameters need to be constantly revised, which requires the high-speed computing characteristics of the CNC system of the grinding machine.

At present, the control system of our GRINDplusIT equipped with HEIDENHAIN is dual-processor. One of the processors is dedicated to high-speed calculations, so as to guarantee high-speed operation of data during grinding.

In addition, there are many grinding cycles in grinding, which are equivalent to a single macro. If programming according to the graphics is very difficult and time-consuming, we have used the “graphic programming” function in the dedicated grinder system. The operator only needs to draw the graphics and the program will be generated automatically. But sometimes this procedure is not effective in all control systems, but also need to design a set of matching post-processing procedures. The special post-processing program we used was jointly developed by KELLENBERGER, a wholly owned subsidiary of Harding, and HEIDENHAIN.
The hardware is based on HEIDENHAIN iTNC 530. All the requirements and functions in the software are developed by KELLENBERGER for HEIDENHAIN's CNC system. The developed system is called “GRINDplusIT” and it is the current control system. One of the CNC systems developed for grinding machines is also the CNC system that we are currently working on.

A special post-processing program and optimized grinding parameters are built into the CNC system, and the resulting graphics generate the programs that this HEIDENHAIN system can recognize. The GRINDplusIT control system also directly recognizes DXF format graphic files. These files can be generated directly by software such as AUTO-CAD. The operating interface is Windows XP Professional, and personnel with initial computer operating experience can be skilled in use. In order to adapt to different optimization needs, the full range of KELLENBERGER products are available with the GE FANUC 310is control system. The hardware of this system is based on FANUC, and the software is also specially developed by KELLENBERGER for grinding machines.

Mr. Shu Zhiyong: There are differences between the cutting process and the grinding process in the following aspects: (1) Servo system acceleration and deceleration and work movement. 2 Geometric description of the shape of the machining tool (grinding wheel or tool) and wear compensation. 3 It is difficult to pack a typical grinding process with a fixed cycle for various types of grinding machines. Because the process of grinding machine is not to remove the excess, but to ensure the ultimate ever-changing process requirements.

So for the special grinder manufacturing, the need is a simple CNC system that only contains the core functions, and then a professional software developer who understands the machine tool to understand the grinding process, and then carries out secondary development on the platform of the CNC system to meet its needs.

Abrasive abrasive escort

Shenyang Institute of Superhard Die Grinding: The abrasive industry is a basic industry, but it has always occupied an extremely important position in machining. In terms of abrasives, there are three aspects of improvement and breakthroughs that are of special significance. First, the improvement of the physical structure of the grinding tools, such as increasing the number of abrasive particles that act on the workpiece per unit time, increasing the average length of grinding, and increasing the grinding contact surface, has changed the amount of grinding per unit time. The second is that the application of superabrasives mainly refers to the application of superabrasive materials such as metal powders, metal oxides or CBN as fillers, and abrasives made of resin, ceramics or metal binders. At present, the high-precision, high-efficiency grinding effect brought by superabrasives has been widely recognized; Third, the emergence of new types of abrasive tools, such as microcrystalline ceramic microcrystalline abrasives, micro-diamond grinding Granules for spherical shells and superfinished polyester films for superfinishing. The characteristics of these new types of abrasive tools have enabled them to fully demonstrate their advantages in grinding.

Throughout the development of the grinding field, the future of grinding will place higher demands on the abrasives. Judging from the current status, super-hard products precisely meet these new grinding needs. Such as CBN abrasive has good thermal stability, high hardness, good wear resistance and other characteristics, so its grinding tools in the grinding process of high linear speed, high grinding efficiency, abrasive life is also high, especially suitable for processing high-speed steel , ferrous metal materials such as bearing steel, stainless steel, and cold-drawn cast iron. In addition, ceramic binder grinding wheels, atmospheric hole high-speed grinding wheels, and grinding wheels with different abrasive grains on different processing surfaces, and diamond saw blades, which meet various needs, will expand the application range as technology advances and become mainstream products in grinding processing. .