Recent Change in the machine tools is discussed in this paper, especially the machining centers with high speed, high acceleration rate and intelligence. High speed machining centers with feed rate of 60 m/min, acceleration rate of 1G and spindle speed of 20,000/min are becoming very popular in the area of aluminum alloys machining. These machining centers have been developed for improving productivity, and will be used for agile and high-volume FMSs. These machining centers are very effective for die/mold making. The remained problems for these machining centers have been discussed. The intelligent machine tools is one of the key technologies which can realize these problems.

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Regarding the new machining technology for Die&Mold, this paper takes up two of the new machining technology to replace EDM with Cutting. First of all, the ceramic ball bearing spindle is introduced. Then two machining processes with Ultra High Speed spindle are introduced. One of them is Air Drive tool, which is introduced for the spindle to be able to offer as the low cost and automatic changeable equipment. Another one is Aero-Static Bearing spindle, which is introduced for the machining process to make use of the merit of Aero-Static Bearing.

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High precision and troublesome setups and changeovers stand in the way of automation in mold production. Simplified setups and changeovers as well as alignment system, which corrects errors caused by attaching / detaching of work palettes, realize mechanization. Automation is accelerated by measurement system after production and finish machining

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In the machining process especially for the mold die of the instrument-panel for the cars among all those large-sized mold die, there is many part on the die where can not be finished to the final shape only by the milling process, because the shapes of the die are great ups and downs and very much complicated. hence. EDM process can be applied in many part of the injection mold die. In fact its process will greatly influence on the lead-time of the injection mold die. So; then we would like to explain about the application of EDM process for the injection mold die of the instrument-panel in this reports.

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Cutting performance of ceramics tools in side milling of Pre-Hardened Steels were investigated and tool failure were compared with those of carbide tools. In case of cutting with ceramics tools, chipping and cracking were occurred at the begining of the cutting and resulted in tool breakage. Carbide tools showed rather superior performance to those of ceramics tools.

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This paper deals with analysis of cutting mechanism of tapered end mills using three-dimensional CAD. At first, calculating method is shown and also appropriateness of the method is verified. Then cutting areas are calculated in the several conditions, and influences of radial depth, taper angle, helix angle and type of milling on cutting areas are considered.

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The level of precision in die and molds becomes higher and higher due to the minituarization and higher functionality of electronical devices and likes. To meet these demand, linear motor wire-cut EDMs are developed; and this report introduces features and applications of them.

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In this paper, we investigated the stability of EDM machining loop using a high speed actuator. The stability condition of machining loop was obtained by describing function analysis. We performed the test of electric discharge machining and it was confirmed that the result of experiment were in good agreement with the result of simulation.

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Today, the demand for microscopic machining becomes higher and higher due to high-density semiconductors, high quality printers, minituarization of IT related products and likes. Linear motor drive EDMs developed by Sodick provides superior performance in microscopic machining because of its high speed and highly responsive servo system. This report mainly explains microscopic hole machining less than φ 0.1mm and other microscopic machining technology with linear motor drive EDMs.

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Microholes have been widely used in various fields of industry such as fuel injection nozzles, inkjet printer heads, fluid sensors and optical fiber connectors. Since the development of WEDG (Wire-Electro-Discharge Grinding), micro-EDM has been an excellent technology for machining micro holes in metals and alloys. However, there remains two main problems of machining micro holes by EDM. One is how to machine micro holes continuously and the other one is how to supply micro tools automatically. This paper deals with a new method which enables automatic mass production of microholes by EDM.

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Recently, electrical discharge machining (EDM) has been applied to micro processing. A thin electrode less than 0.1mm in diameter has been used for the micro EDM. In conventional micro EDM, minute energy is supplied to the gap region for micro removal machining. In this study, we carried out some experiments on single discharge machining with thin electrode. The value of discharge current was selected up to 50A as the machining condition. The electrode wear length was measured for several pulse durations. As a result, we found out the electrode became thinner than original diameters at the edge portion under pulse duration of several hundred μs in a single discharge. A needle of 35μm in diameter and 300μm length can be made instantaneously from a tungsten wire of 0.125mm in diameter. Using a thin electrode, micro drilling could be performed on the machine.

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Insulating ceramics can be machined by electrical discharge machining (EDM) with an assisting electrode method. During the machining process, a carbonization phenomenon occurs on the workpiece surface continuously due to cracked carbon from working oil. And the carbonized surface has electrical conductivity. However, because of discharge concentration and discharges with long pulse duration, the machining characteristics such as removal rate and surface roughness are inferior to those of he electro conductive materials. This paper describes the machining rate of insulating Si_3N_4 ceramics by this method in which several kinds of powder are suspended in working oil. With help of powder suspended oil. the removal rate was improved due to the decrease of discharge concentration. The removal rate in drilling Si_3N_4 by EDM leads almost the same by grinding process.

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The tribological properties of an EDC coating, the surface modification by the electrical discharge machining, were examined and compared with CVD and PVD coatings. As a result the next things became clear. (1) Friction coefficient of an EDC coating becomes smaller than CVD, PVD coatings, and becomes degree the same as that of SUS440C. (2) Wear resistance of a coating is a turn of PVD, EDC, CVD, and a TiAlN coating by PVD is hard to wear most. (3) The EDC coating is hard to wear about 5-10 times than a case without a coating. (4) Each coating of EDC, CVD, PVD is easy to let partner materials wear than a case without a coating. (5) As for the EDC coating, the wear of partner materials increases with increase of friction speed remarkably. From the above, it is clear that an application to the die surface and a tool is capable.

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This study describes a new discharge pulse pattern in order to make a hard TiC layer, which manufactured by an electrical discharge machining (EDM) with a semi-sintered electrode. In order to improve a hardness of the TiC layer, it needs to extend a diameter of crystallite on a crater formed by a single pulse discharge. To extend the diameter, we proposed a small discharge current (heating pulse) following to a former pulse pattern to increase a cystallite growth time. We investigated the time on the discharge crater with a thermal analysis and examined it experimentally. The results are as follows; The cystallite growth time is increased to 1.3 times by the heating pulse. The diameter of crystallite is 2.5 times as large as the former one and the TiC layer become harder by 15%.

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There are several approaches to increase productivity. One of them is to shorten cutting time by means of high-speed and high-performance machining operations. Especially, the aerospace industry that has a high ratio of aluminum cutting time is directly influenced by the high-speed machining technology to increase productivity. However, the current medium and large size machining centers whose axial strokes exceed 2000 mm (78.74inches) have not reached the cutting feedrate necessary for high-speed machining due to the limitations of ball screw drives. In order to solve such a problem we have developed a high-speed machining center employed with linear motors instead of a conventional ball screw drive. This paper introduces the technology.

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High speed, high productivity tapping has been studied by using newly developed intelligent machine tools. The intelligent machine tools have three levels of feedback loop, which can control the cutting forces and torque during tapping process and can decide the cutting conditions. Cutting forces and torque, which are estimated by internal sensor, coincided with measured force and torque of tool dynamometer during tapping process. By using the signal from internal sensors, the monitoring of the cutting forces and torque of M4 tap and larger for steel, cast iron and aluminum alloy were proved to be possible through experiments. The cutting forces and torque increase as the tool wears, so tool life was estimated by the increase of cutting forces or torque successfully. And monitoring the chip jamming during tapping process was also proved to be possible.

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Au ultraprecision grinder is developed which can grind hard and brittle materials such as silicon, glass and ceramics by a cup-type grinding wheel. It has the following characteristics; (1)It is relatively small and stiff because the grinding wheel spindle and workpiece spindle are set horizontally. (2)A fine and coarse positioning device can give very low speed of 1∿100nm/s to the workpiece spindle after a high speed greater than 100nm/s under the feedback control of the workpiece spindle. The results are; (i) For the silicon wafer of 150mm diameter, the surface roughness of 4nm Ry and flatness of 0.2μm can be obtained by partially ductile mode process. (ii) For the ferrite and alumina the surface roughness of 2∿4μm Ry can be obtained by perfect ductile mode process.

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The linear motor drive machining center HVM (High Velocity Machine) has been developed to target customers mass producing automobile parts and those machining aluminum airplane parts. Already, over 100 machines are installed and in operation in major automobile and airplane manufacturers in Europe and in the United States. MORI SEIKI combined the experience and knowledge of designing and assembling linear motors made available through technical cooperation with THE INGERSOLL MILLING MACHINE COMPANY, with the latest mechanical technology developed by MORI SEIKI to develop a full-scale linear motor drive machining center, HVM630,with increased accuracy, productivity, and reliability. By discontinuing the use of the ball screw, ball nut, ball screw support bearing, and couplings, and other parts that distort in the feed direction to raise the servo loop gain, we were able to achieve a circular machining accuracy of 1.8μm (F=2,000 mm/min, R=15 mm, peak to valley).

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Giant magnetstrictive materials (GMM), as being called lanthanoid-iron compounds, changes their permeability extremely when the externaly stressed. This alternation of the permeability is fundamentally coincident to the displacement that resulted from the varied crystal lattice of GMM element by the external stress. On the other hand, the relation between external stress and permeability which caused the alternation of internal magnetization being existence histeresis due to the ΔE effects. The purpose of this study is to ascertain the static characteristic and develop a telecommunication system using GMM pressure sensor.

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This machine is for grinding cylindrical portions (pin portion) of a compressor shaft etc. used in an air conditioner whose pin center is eccentric relative to a rotational center of the shaft, by following a feed motion of a wheel head to a rotation of the shaft. In order to improve both productivity and machining accuracy, it is required not only to rotate the shaft at a high speed but also to accurately move the wheel head. In this machine, the high speed and high accurate grinding has been realized by using a linear motor as an actuator of the wheel head. The machine construction, principle of pin portion profile grinding and machining result are explained.

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This paper describes the horizontal machining center with turning function. In the past, when machining parts such as valve and pump, the turning process was essential for machining of a large-diameter seat surface and an inclined surface. Now, machining of such surfaces can be taken over to the single horizontal machining center, thanks to the development of a new machining center (NX76B) and ORBIT BORING function (i. e., turning function). The most outstanding features of this horizontal machining center are summarized as 1) machining of various diameters with same tool, 2) realization of facing operation without U-axis control function, and 3) realization of both turning operation and operation of a horizontal machining center by the single machine.

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This paper deals with the introduction of a fully automatic CNC tool and cutter grinding machine operated by a graphical user interface. The axis configuration of this machine was determined to minimized the number of CNC axes in order to reduce complicated machine construction and to make the machine operation easier. The software consists of mathematics calculations and data base parameter storage. Graphical user interface supports an easy and correct operation. Cutting tools that should be ground are measured on the machine automatically by using a touch sensor and controlled CNC axes. That is why the operator runs the machine with minimized keyboard data input. As a result this machine can grind various kind of tools without operator's knowledge about the tools and avoids machine crash by miss operation.

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This paper deals with the stable efficient drilling by intelligent machining center. Intelligent functions for drilling are tool life detection, adaptive control, quick retract and adaptive pecking. The integration of those functions in the whole drilling process has been studied and the intelligent drilling scheme is proposed and tested.

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We have developed the new technology for grinding cam which gives the optimum rotation speed of cam. Since the rotation speed of cam is controlled by the calculations based on the relation between the rotation angle of cam and the ratio of peripheral velocity, the grinding resistance can be continually kept constant in one-rotation work. Consequently, the accuracy of cam profile was improved as compared with former control by experience and intuition.

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It is said that an approach to environment problems is necessary to prevent the global warming. The correspondences of the global warming and the waste disposal are necessary for the machine tool as well. Carbon dioxide is said as the cause of No.1 of the global warming. It is necessary to saving energy for reduce the discharge of carbon dioxide. A machine tool uses a wide area when it is compared with a product. We researched the base technology, and developed a prototype of the small sized, low energy, multi spindle automatic lathe "ECOM". This machine occupied only 1/6 of floor space and power consumption was 1/3 in comparison with Tsugami automatic lathe.

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This article explains the main specification and features for NC lathe that is built on the latest digital intelligence, which meets the need for the next generation, of "High Speed" supported by ultimate reliability and affordable "High Quality Machining".

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Lately the multipurpose Lathe machine added features of face milling and drilling has been increasing the supplemental value. Mitsui Seiki Kogyo has also complied the customer's needs by offering five axes machining center in order to increase the supplemental value. Here I would like to introduce our newest five axes machining center together with its background of research and development, machine characteristics and machining cycle time data.

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Our biggest aim is to develop a machine tool having heavy-duty and high-speed machining performance that allows various operations ranging from roughing to finishing as per specified profile. Workpieces mainly machined by this machine are small-and middle-sized dies and molds. Since 1996 when we first put out our portal type machining center MPF-2114C on the worldwide market, this machine has been popularized for its high rigidity and high accuracy among users domestic and overseas. Recently, however, with increasing needs for large-sized mold dies, increase in machining volume is urgently necessary. This is why we developed the ram type machining center with crossrail to realize the large machining volume, while following suit the machine structure of the MPF-2114C machine.

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The mainstream solution in the machining line for aluminum engine components; i.e., cylinder blocks and cylinder heads, has been provided by a transfer line featuring a multi-spindle machining device. In spite of the advantages it can offer, the conventional system is found less appropriate for meeting recent demands. These demands are; minimized investment for adapting the system to new production, and enhanced flexibility to cope with more diversified manufacturing demands. A possible answer would be machinary that simultaneously achieves production efficiency similar to that of the multi-spindle machine and the flexibility of the NC machine. To achieve this goal, the "HVT-6000", an ultra high-speed machining center featuring a tilt-positioning mechanism using direct drive (DD) motors, was developed.

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The ball screw for high speed machining center series which is a feed speed 100m/min is merchandised to cope with a demand for increasing the feed speed of machine tool. We realized the ball screw specifications such as ball diameter, ball center diameter are related for noise creation and the ball screw for high speed machining center series are controlled these factor to minimize the noise level. Recently, a demand for the noise reduction of the ball screw has been getting higher from the point of the environment countermeasure. This report is the result of the consideration and the examination of noise level and vibration of ball screws which are used in machine tool.

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This paper describes the lubricating characteristics of LM-guide at the point of out-particles from LM-guide. After, we investigated the contents of out-particles, we did improve in lubricants and in structure of LM-guide for low out-particles. We can reach "Super clean guide" using new structure and new lubricating grease (AFE or AFF). This "Super clean guide" can provide extremely low out-particles characteristics of less than 1% of normal liner motion guide.

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This paper describes the development of a ultra-high speed spindle using ceramic ball bearing. Recently, rotational speed of ball bearing spindle for machining center must be increased to satisfy the requirement of high-productivity. In this paper, we present two types high speed spindles which are a 50000 (min)^<-1> spindle with a diameter of 50mm, and a 20000 (min)^<-1> spindle with a diameter of 90mm.

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This study deals with the improvement of high-speed spindle through supply system. During high-speed spindle machining large amount of pressurized lubricant is usually supplied to cutting area. From view point of the environmental protection, recently, the minimum quantities of lubrication system (M.Q.L) has been developed and applied to the metal cutting progress. When the spindle rotates at high speed, the mist flow is, however, blocked out from the machining area by the high-speed circular airflow. The spindle through coolant supply method is effective to supply the oil mist to cutting area in high speed machining. The oil drops are separated from the mist flow due to the centrifugal force during high-speed rotation. In order to suppress the influence of centrifugal force, a special type of oil mist supply mechanism was also developed and installed to the draw-bar shaft of spindle system.

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Aerostatic porous journal bearings are very suitable for precision devices such as ultra-precision machine tools and precision measuring equipment. However, it is said that aerostatic porous bearings are prone to cause pneumatic hammer instability, unless the surface restricted layer is formed on the bearing surface. This paper theoretically investigates the dynamic characteristics of aerostatic porous journal bearings with a surface restricted layer. In addition, the influences of various design parameters on the dynamic characteristics are discussed and the effects of the surface restricted layer on pneumatic hammer instability are clarified.

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For the purpose of designing the higher stiffness aerostatic bearing, the pressure distribution of the face of bearing in the porous aerostatic bearing is measured by the equipment of our own making. Therefore, it is found that how the amount of flowing coefficient, the clearance and the supply pressure contribute to the bearing performance.

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This paper describes the friction coefficient between chuck-part made of aluminumalloy and spindle made of steel, which is obtained in the experiment. In the experiment, the friction force is loaded by a PZT-element in the direction perpendicular to the bolt thrust. The friction force and the bolt thrust are measured with load-sensor of Kistler and A/D converter, and the friction coefficient is calculated as the ratio of those forces. It is clarified that the friction coefficient gradually increases with the increase in relative displacement between chuck-part and spindle under small displacement.

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In the manufacturing process, engineers often estimate the deformation of clamped workpieces from their features, and select clamping points with minimum deformation. In this paper, the fixturing features which composed of the form features, the compliance features and deformation features are proposed in order to determine the optimum points for clamping a workpiece. And the effects of the method of deciding the best clamping points applying this concept are confirmed for two-dimensional workpieces.

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This paper describes a method of collision avoidance on the tool path generation for 5-axis control machining. The proposed method is able to avoid the collision between tool and workpieces. In the method, the avoidance angle and avoidance direction without collision are analytically calculated under the continuity for the tool-posture and machining conditions. A prototype CAM system has been developed in this study. This system is composed of the tool path generation module, post-processor and NC-simulation, in order to deal with the collision at the cutting points which are generated by linearization process. And it has been applied to machining for a marine propeller. As a result, the validity of the proposed method is experimentally confirmed.

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The virtual copy milling system has been developed. In the virtual copy milling system, a stylus and a master model in copy milling are defined as geometrical surface models, and the stylus motion corresponding to the tool motion is simulated by applying copy milling principle. This method is simple enough to generate the tool motion in real time, and experimental cutting have been succeeded to show NC programless milling of sculptured surface. The real time tool path generation is indispensable for the adaptation of cutting conditions such as depth of cut and feed speed to maintain stable machining. In this study, the machining strategy for the adaptation of cutting conditions is proposed to realize an autonomous NC machine tool.

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This paper deals with a high accuracy NC cutting simulator, which is able to represent the effect of a tool deformation, motion error and so on, based on Boundary-Map geometric model. Although a CNC controller executes interpolation, smoothing and servo control of tool path, these functions may cause a motion error. To emulate these functions of CNC controller, a crowd of points for tool path is generated based on a NC program. At the each crowd of positions the removing process from work-piece can be simulated by applying set-operation to the Boundary-Map data. The shape simulated by this NC simulator is compared with the machined shape using the same NC program. As a result, it becomes clear that the developed NC simulator can emulate enough the motion error caused by NC controller and enables to simulate accurately the effect of the error upon the machined geometric shape.

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To produce die/mold consisting of smooth curve surfaces by hale (non-rotating tool) machining, it needs simultaneous six-axes controlled machining center. Therefore, we developed a system of six-axes hale machining and that of creating NC data. We got the following results from the whole system. Firstly, we cut curve surfaces both by five-axes as well as six-axes machining center, evaluated the machined surface and cutter path. Secondly, during cutting we maintained the movement of the tool axis as small as possible so as to improve surface roughness (Ry). Finally, we succeeded to achieve Ry of curve surfaces less than 1μm.

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The study deals with the development of an integrated main processor of six-axis control CAM system. The six-axis control machining, where non-rotational cutting tools are used, has a lot of advantages, compared with the conventional one with rotational cutting tools. The main processors, which have developed till now, can generate CL data corresponding to the kind of six-axis control machining such as smooth machining, grooving, character line machining, sharp-edged corner machining, pocket machining, etc. However, it is not convenient to prepare the main processor for each six-axis control machining method. To solve the problem, the integration of the main processors is intended, where CL data corresponding to specific machining method is automatically generated on the basis of judgment of the shape pattern standing for the kind of six-axis control machining. As a result, it was experimentally confirmed that the integrated main processor has the potential to select the suitable six-axis control machining method and generate the corresponding CL data.

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Problem of 5 axis machining is that selection of machine tool, shape of tools, machining method, and NC programming. This paper report the machining method and NC programming for 5 axis machining.

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