Tool and cutting technology for high speed milling and multi-turn turning centers
In terms of cutting, we are hoping to establish a fast-moving production system, and we are the first to introduce high-speed milling tools.
At present, HSK tool holders have been widely used in Europe for the connection of machine tool spindles and tools, such as machining centers, and ISO standards have been developed. This tool system is being promoted in Japan. So far, Japanese manufacturers have developed a variety of tool systems, and the connection method is even more varied. Users are very confused when they purchase. Therefore, Japanese machine tool manufacturers and end users are hoping to develop an HSK tool system for turning centers. At present, a total of 16 tool companies and chuck manufacturers in Japan are jointly developing such products, and mass production will soon be possible. This can achieve extremely good results for improving processing efficiency, reducing production costs, and improving processing quality.
Sodick has developed a three-axis linear motor driven small machining center (table size 400mm × 600mm), which is a high-speed milling machine with a maximum spindle speed of 40,000r/min compared to other similar machines. The cost is reduced to less than 50%. In order to guarantee machining accuracy and tool life under high-speed milling conditions, the machine uses a hot-fit tool clamping system. This trend will continue to develop in the future. For example, the end mill series developed by MMC Kobelco Tools for hot-fit tool clamping systems, these end mills maintain a minimum amount of protrusion as far as possible for stable high-speed milling. Many of the products produced by companies that produce hot-fit clamping systems use electromagnetic induction heating methods produced in Europe. A new electromagnetic induction heating device developed by Japan YES Electronics Industry Co., Ltd., trade name MEGAHEATER. This is a pocket-sized hot-packing device that uses a new electromagnetic induction method to overcome the adverse effects of electromagnetic induction in the past. The power supply (called mega heater) is a box structure, which saves equipment space and is novel in design. Easy to operate.
In order to simplify the production process and achieve ultra-short delivery deadlines, turning centers and five-axis controlled machining centers require a large number of multi-tools. MAZAK has developed a series of multi-tools for the turning center. These tools are cut according to the instructions of the NC program. A tool can complete various internal and external cutting, internal and external thread cutting, boring, end milling, etc., from blanks to blanks. Complex shaped workpieces can be completed in one operation. The Makino milling machine is installed on the vertical machining center to install the indexing device. With the machine's own multi-axis control function, it can complete the machining of multiple parts in one process.
The latest trends in general cutting tools
Coating treatment is an important means to greatly improve tool performance. At present, tools for coating carbide, alumina, and nitride on the surface of a cemented carbide (ultrafine grained cemented carbide) substrate have been widely used. The latest achievement of Hitachi Tools' nano-coating technology is the development of TiSiN and CrSiN coated end mills. The two coating materials have a particle size of 5 nm. The former can process high-hardness steel of 50-70HRC at high speed. High-speed and high-precision machining of 43HRC mild steel and pre-hardened steel. Both coatings have better hardness and oxidation resistance than other coatings, and have outstanding effects in extending tool life and shortening cycle time.
Sumitomo Electric has developed DLC (Diamond Like Carbon) coated milling inserts, which are best used for dry machining of non-ferrous metals such as aluminum alloys. Products such as carbide end mills and drills with DLC coating have excellent surface lubrication properties and are ideal for dry cutting. In the past, deep hole machining was difficult to use for dry cutting. Fujitsu has introduced a long drill that can perform semi-dry (MQL) deep hole machining with a depth of 20 times the drill diameter. This drill is also DLC coated. DUET has developed a Beam drill that integrates diamond and hard alloy. It is characterized by the absence of weld defects, long service life, excellent cutting sharpness, regrind, and the ability to produce small diameter drills of φ0.4 mm. Beam drills are mainly used for high-speed hole processing of aluminum alloy, fiber reinforced plastic (CFRP), metal matrix composites, engineering ceramics and other materials.
The development of tool materials is extremely active. In addition to the above-mentioned coating products, there are coated blade T9000 series (Toshiba Tungaoy) which has increased coating thickness to improve cutting performance, and ceramic blade HW2 series with excellent resistance to breakage (Japanese special Ceramics, etc., these blades are superior to the previous similar products and have good cutting performance.
In addition to the above-mentioned types of tools suitable for dry cutting, many tool products have been developed to improve machining efficiency. For example, MRALE ORBIT, a multi-functional end mill developed by MMC Kobelco Tools Co., Ltd., is a special short-blade tool for profiling. It features a very high dimensional accuracy of the tool nose arc R for large feed cutting. The scope of application is very wide. Mitsubishi Materials Corporation has developed an indexable end mill with a unique shape, the main component of the cutting action acts on the axial direction, the side edge does not cut, and the cutting edge is cut near the bottom, so the cutting is very smooth. This end mill has a cutting depth of 1.5 to 2.Omm and a feed of 3.5 mm per tooth. Compared with other end mills, the feed rate is greatly improved. Kyocera has introduced a multi-functional end mill. Similar tools have already been sold on the market, but Kyocera has made significant improvements in the shape of the blade, which can effectively reduce the cutting force. The bottom edge of the blade is horizontally flat. This type of end mill can perform various machining such as grooving, cutting sidewalls, drilling, and inclined cavity milling. ISCAR's newly developed butterfly milling cutter blade with a cutting angle of 8 cutting angles and a tangential installation for stable cutting with large feed rate. The production efficiency is increased by 2.5 to 3.8 times. Has been widely adopted by the automotive industry
In order to reduce the weight of the milling cutter body and improve the cutting efficiency, many manufacturers have developed aluminum alloy cutter body high-speed face milling cutters, such as Sandvik's Coromant 590 face milling cutter and Sumitomo's RF profile milling cutter. These aluminum alloy cutter face milling cutters have high anti-centrifugal force characteristics when the high-speed rotary handsome 80mm tool speed is 17000r/min. The blade is firmly clamped, not easy to fall off and throw out, the insert pocket is large, and the blade and the cutter body are both Not easily scratched by chips.
In addition, OSG has introduced a carbide tap that is mounted on the machining center and uses the three-axis control function of the machine to form planetary motion. A tap can complete internal threads, external threads, right-handed threads, left-handed threads, etc. A kind of tapping processing, such a tap has a great effect on the rationalization of tapping processing.
Eye-catching tiny diameter cutter
At present, one of the effective measures taken by the Japanese domestic manufacturing industry in order to get rid of the economic downturn is to produce products with high added value. The characteristics of this type of product are that many parts must be processed in a fine shape, and in order to improve the market competitiveness of these products, high-efficiency and high-precision machining is required in almost all manufacturing fields.
With the rapid development of the processing shape, the requirements for the tool must be smaller, the precision is more strict, and the service life is longer. For example, Mitsubishi Materials Corporation has developed a series of small-diameter end mills, in which the ball nose end mill and square end mill have a minimum diameter of φ0.2mm and a maximum length of 1.5mm. Carbide products. Rijin Tools has introduced a carbide end mill with a diameter of φ50μm, which is mainly used for the processing of fine grooves with a depth of 50μm. It is said to be the smallest diameter of the current end mills. The use of small-diameter end mills for micro-machining is very difficult, but it is very difficult to trim the machined surface after cutting. Users want to use an end mill to complete the final machining process. Under normal circumstances, the cutting time consumed by high-precision shape processing often takes several hours. Therefore, higher requirements have been placed on the tools used for the machining of the micro-shapes, that is, the cutting performance (the sharpness of the blade tip, the surface roughness of the machined surface, etc.) and the tool life are superior to those of the general tool. The φ1mm CBN end mill of Rijin Tools Co., Ltd. has a tool life of more than 10 hours and a machining surface roughness of less than Ry1μm when the machining conditions are 120000r/min, feed speed 5000mm/min, and cutting depth 0.02mm. The rake angle of the end mill is negative, and the shape of the cutting edge is specially designed to have good impact resistance at high speed.
The small diameter of the drill bit is progressing rapidly. Sumitomo Electric Company has introduced an MDSS type carbide drill with a minimum diameter of only φ30μm and a maximum machining depth of 2D. The company also produces a φ0.2mm carbide drill with a maximum machining depth of up to 1 OD (D is the drill diameter).
With the high density and miniaturization of printed circuit board wiring, the development of ultra-small diameter PCB drill bits has received further attention. At present, PCB drill bits of φ0.1 to φ0.2 mm have been widely used, and some special small-diameter PCB drill bits (φ0.075 to φ0.05 mm) have been used. As we all know, the thickness of a person's hair is roughly φO.1mm, and the inner diameter of the injection needle is about 0.4mm. It is known that the PCB drill bit of φ0.05mm is smaller than the hair.
In the micro-diameter drilling process, in addition to the selection of a suitable machine tool, special attention should be paid to the following problems: the shape and accuracy of the guide hole, and the vibration of the tool under the condition of high-speed rotation (φ0.2mm bit speed above 30000r/min) Pendulum accuracy, intermittent feed times, and repeatability. These factors are all necessary for stable cutting. In the case of micro-drilling, slight negligence will seriously affect the processing effect.
It is expected that the demand for tools for micro-machining will increase rapidly in the future, and the development of such tools and related equipment will be highly valued. A high-speed spindle head has been developed, which can be mounted on a machine tool such as a machining center to achieve high-speed rotation, which is extremely advantageous for micro-machining. Currently, such spindle heads have been put on the market in batches. UNION has introduced a stochastic measuring device that measures the accuracy of the cutting edge of the tool. This device can be measured with the tool turning, which is very convenient for judging the accuracy of the tool during the cutting process. The development and utilization of these related devices provide a more convenient way for the efficient and high-precision micro-shape machining to be carried out efficiently.