A diamond tool tip temperature in a micro cutting was measured by a two color pyrometer with an optical fiber. The use of the fiber facilitates the acceptance of infrared rays radiated from a very small cutting area. The independence of a two color pyrometer from a size of an object was experimentally confirmed. In the cutting experiment, a conical, single crystal diamond and a sintered aluminum were used as cutting tools, and a titanium and a tungsten carbide were used as workpieces. The tool has a small hole and the fiber was inserted into the hole. During the cutting, the fiber accepts the infrared rays radiated from the tool-chip interface and transmitted through the cutting tool. The diamond tool tip temperature in titanium cutting is 300°C when the depth of cut is 2μm and 600°C at 45μm. Compared with the cutting with aluminum tool, the diamond tool tip temperature is much lower than the aluminum tool tip temperature. In the cutting of tungsten carbide, the diamond tool tip temperature is over 1000°C when the depth of cut is 1mm. The tool is worn with cutting and the tool tip temperature increases with the tool wear.
The fusion splicing of ribbon-shaped eight optical fibers was carried out with CO2 laser beams. At first, laser beam of uniform power distribution, which was obtained by simple aperture method, was irradiated to every fiber. However, defective connections were frequently occurred at both edges of the ribbon fibers, because the heat inputs to these fibers were low and not enough to melt silica glass fibers. Two-dimensional heat conduction analysis indicated that the reason was the large heat transfer and radiation from these fibers to atmosphere. Therefore, higher laser power was necessary to be supplied to two edge fibers. Laser beams designed specially, which had about 20∼22 % higher power density at edge region, enabled the temperatures of all fibers to reach their softening point simultaneously. As a result, excellent connections with low splicing loss of 0.011dB on average values were achieved.
CMP is the standard planarization method for silicon wafers. For semiconductors of the next generation, a flatness of less than 0.1 μm is required on a 12" wafer. We have developed an oscillation-speed-control-type polishing machine that modifies a wafer's profile accurately. In this polishing, an appropriate polishing theory has to be used for the simulation that calculates a wafer profile. This report shows how the pressure distribution and the contact state change with the overhang of the polishing tool and type of a polisher used. The simulation showed that pressure distribution is linear, contact length is constant for polishing head pressure and polisher elasticity. On the other hand, the experimental results show that pressure distribution is non-linear in the case that the tool-overhang is large and the contact length changes when polisher types are different. It was shown that the characteristic of polisher elasticity has to be taken into account for the polishing simulation.
This study aims to develop an injection molding technology for micro plastic parts below several μm in size. An ultra high speed injection molding machine applying dropping force of weight, which performs high speed injection using the impact load of a free-fall weight, and a focused ion beam fabrication machine were used to fabricate micro molds, and attempts were made to fabricate micro plastic parts 50μm in size. To achieve the fabrication of parts in micro order size, investigations were particularly carried out on cavity insert structure and mold structure including the material. The results showed that the WC-Co cavity insert is more appropriate for molding compared to Ni plating cavity insert which has problems such as deformation of the runner and gate and micro cavities as well as flush of the molded product. Using the WC-Co cavity insert, star-shaped products of 50μm in maximum size with little flash were successfully fabricated.
This report proposes the suppression method of the stick motion at quadrant changes by the real-time inverse transfer function method without identifying the parameters previously. The dynamic characteristics of 2-axis NC table are identified by real-time calculation as the second regression function with consideration of variables for parameters during motion. The real-time compensation is executed by the identified parameters that show the characteristic values at quadrant changes. The trajectory error by the proposed method has been suppressed 37.1% of that by the conventional feedback control during air cutting. As the result of applying to the circular interpolation machining, the contoured profile of the workpiece by our method shows the suppression of 43.6% of the stick motion.
A cylindrical-lensed optical fiber is used for single-mode fiber coupling for 980-nm pump lasers. This paper proposes a new machining method for the cylindrical-lensed end of an optical fiber. The method uses the bending force of the optical fiber which has homogeneous elasticity characteristics. The rational machining condition is clarified from an elasticity analysis.
High flatness and smoothness are required for an extremely large rectangular glass mask of about 1 m used for pattern transfer of liquid-crystal panels. However, it is difficult to polish rectangular plates with a rotary polishing machine. Therefore, a new simulation program for a rectangular workpiece has been developed. This paper describes the shapes that were non-symmetrical about the central axis generated by grinding, the method to change to a center-axisymmetric shape, the compensation method of tool inclination for simulating polishing, and a comparison between experimental and simulated results for a rectangular workpiece. It was shown that a center-axisymmetric shape can be obtained by grinding at an infeed rate of less than 1 μm/min after dressing to decrease the grinding force, and that the relationships between removal rate and both relative velocity and pressure are proportional for quartz materials. The simulation results agreed with the experimental results under various conditions of tool positions, oscillation ranges and tool diameters by using the new compensation method of tool inclination.
The purpose of this study was development of the rotation type actuator that applied the EHD phenomenon. The EHD is a phenomenon that generates the flow in the insulating fluid by applying a high voltage electric field. In this study, firstly, the electrode arrangement which makes the strong EHD phenomenon was investigated and the EHD motor applying that electrode arrangement was developed. In the next step, the EHD motor using the developed electrode arrangement was manufactured as an experiment. Then, the electrode arrangement of the EHD motor was changed, and the performance change of the EHD motor was examined.
The objective of this study is the standardization of machining information and the development of operation planning support system that uses the standardized machining information. First, machining information of tool, holder, machine tool, etc. are standardized by creating the database on the basis of XML technology. The developed system consists of XML database of machining information and some software modules. The cutting condition determination module determines cutting condition, the tool path generation modules generate cutter location data, and the post-processor module generates NC data, while referring to the information in XML database. Also, the system adopts the case based reasoning technique in the calculation of each module, which uses the product data stored in the system as the machining know-how. In machining experiments, the developed system is mounted on PC that is connected to 5-axis control machine tool with open CNC. The result shows that the developed system enables sequential operations from the determination of cutting condition to the actual machining only by inputting the bare minimum of information, and the effect on the laborsaving in operation planning is indicated.
A solid model representing a product requires filleting or blending, which rounds a specified edge or vertex, in order to make a production model for manufacturing purpose such as mould die model. As a surface representation, current major solid modeling CAD systems use a tensor product surface such as B-spline or NURBS surface. Representing blend surfaces using tensor product surfaces, however, causes several problems in the case such as, blends for meandering shapes or blends degenerate at one side of a surface. We propose a new blend algorithm which makes blend process robust. In this report, we show a procedural blend surface representation that intersections of offset surfaces are represented in procedural curves and basic blend surfaces values, point positions and differentials, are interrogated through that curves. Several examples are shown to verify that procedural blend surfaces have higher quality compared to tensor product surfaces.
Laser beam scanning technology has been used in various machinery such as laser beam printers, laser processing machines. Recently, the usage such as distance sensors for automobiles, area sensors for robots has expanded further. According to it, the miniaturization of beam scanning equipment, advanced features, and low-pricing have also come to be called for strongly. We suggest a method of two-dimensional beam scanning by driving a lens with an electromagnetic actuator. We use suspension wires to hold the scan lens. As a result, two-dimensional beam scanning is possible by simple structure. This paper describes the structure of the scanner module system and characteristics of the prototype model.