[in Japanese]

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[in Japanese]

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Welding process is one of key processes in industry, but weld-joint geometry, such as grooves and fillets, is not easily generated from given parameters. To support the generation of welded-part geometry, a rule based system is proposed and implemented. First of all, geometry of raw material is refined by shifting or cutting suitable for welding. An IF-condition of the rule consists of geometric parameters and user defined parameters. A THEN-clause of a rule is a procedure of generating a weld-joint geometry, which sweeps a cross section of groove or fillet weld along the surround loop of contact faces between raw materials. Welded-part geometry can be generated by set operation between weld-joint geometry and raw material.

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To automate semiconductor bare chip placement operation for the flip-chip-attach, a robust image processing method for realizing high accuracy and reliability is required. This paper proposes a method for measuring a position of a semiconductor bare chip and a chipsite on a module board. Both the position of a solder bumps array on the bottom surface of a semiconductor bare chip and the position of a contact pads array on the surface of a module board are measured in gray level images. Because gray levels of pixels are evaluated relatively and the number of parameters that influence the result of image processing is few in the method, robust and high reliable alignment is performed. As the experimental result, the method provided practical alignment accuracy and reliability for the semiconductor bare chip placement tool.

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The purpose of the study is three-dimensional evaluation of unaxisymmetrical form by using a contact type measuring equipment. The characteristic of the proposed method is to be able to compensate six setting errors which are x, y, z-directional components and rotational components around x, y, z-axes. Algorism which is based on simplex method is proposed to search the errors. The merit of the proposed method is to be robust to multipolarity of the objective function. The function is composed of the sum of square deviations among measured data and reference model data. The errors to minimize the function are searched by the proposed method and are removed by coordinates transformation. The following facts are revealed by experiment : (1) The accuracy of three-dimensional evaluation is 0.7 μm (P-V), which is confirmed by measurement of a master paraboloidal mirror. (2) The measured results by the contact type measuring equipment and CMM resemble well.

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This paper deals with the total tuning method of NC feed drive systems for the aim of decreasing the contouring error in synchronous drive of multiple axes. The tuning process proposed in this paper is not an automatic process but a conversational process using JK-map. JK-map is a graphical human interface to show designers “where they are now” and “where they should go” on the evaluation of the machine performance. In the simulation case study, it is shown that the contouring error of a machining center is drastically reduced using the total tuning method.

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In a SCARA-type robot, coupling forces act between the joints. To improve the dynamic behavior and to reduce the time of a working cycle, it is necessary to compensate for the force generated between the joints. The active coupling torque of the arm is expressed by the sum of acceleration-coupling terms due to the nondiagonal element in an inertia matrix and the Coriolis and centrifugal forces. If the exact angular acceleration θ is known, the coupling torque is easily estimated without calculating the complex inverse dynamic mechanics. This paper describes the decoupling control in a SCARA-type robot using acceleration sensors for the estimation of these terms. In an experiment servotype acceleration sensors having high resolution and linearity at low frequency were installed to the arms. A simple control algorithm that can decouple the joints by applying a nonlinear compensation feedback control is proposed. The proposed method showed satisfactory results even for the stepwise input signal of a velocity command. It could reduce the position errors to less than 47% when compared with the traditional PI control.

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The authors develop a fast-processing algorithm of low- and high-pass Gaussian digital filters executed while one discrete data of traced profile is sampled. In this report, the 8-step modified running-box-function filter is newly presented. The transmission characteristics of this new filter are very close to those of Gaussian digital filter provided by ISO 468-1982. Furthermore, the conditions to utilize this filter are shown for a practical use.

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The plant inspection and diagnosis robot (I.D.R.) proposed in this study will search a faulty part in a machine by sound signal with the following steps : (1) detecting the failure, (2) searching the faulty machine and (3) searching the faulty part in the machine. (1) and (2) have been discussed on the 1st and 2nd reports. This paper discusses the searching method for the 3rd step. The contents of this paper are : (1) collision avoidance method of the manipulator equipped on the I.D.R. A sound sensor is installed on the manipulator for measuring sound signal; (2) the control method of the manipulator for searching the faulty part by using Genetic Algorithms (GA); (3) showing the method of obtaining the initial genotype population for the GA control; (4) verifying the efficiency of these methods by practical application.

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This paper deals with the experimental analysis on the stability of a regenerative chatter vibration in end mill operation. A series of side cutting tests carried out under various cutting conditions and vibration characteristics of an end mill in order to investigate the influence on the chatter stability limit. The results obtained are as follows : (1) An unstable region on a surface generated by one cutting was examined and it agreed approximately with the theoretical result. (2) Low cutting speed and large feed rate increases the chatter stability. However, width of cut and depth of cut has almost no effect on the chatter stability in usual cutting condition. (3) The chatter stability in down milling is lower than that in up milling. (4) High helix angle of the cutting edge increases the chatter stability. (5) The experimental values of the chatter stability limit agree well with the theoretical results. As a result of this, the validity of the theoretical analysis was confirmed.

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Compound gear lapping is to increase a certain degree of accuracy by lapping a pair of metal gears in mesh, and at the same time to improve roughness of tooth surface by lapping the metal gears in mesh with plastic gears at the shaft angle. The metal gears are lapping during traverse feeding in the place where oil coolant mixed with fine abrasive grains is spouted. The lapping test shows that only irregular profiles of the metal gears are removed and meshing noise is reduced. The test also finds the following; widely uniform tooth contacts are obtained by means of the plastic gears made of Polyacetal and fine adjustment of the shaft angle. Meshing noise is reduced to approximately 86 dB by selecting proper lapping conditions. The best tooth profile and the smallest meshing noise are achieved at the lapping time of 20 seconds. The profile is deteriorated and meshing noise becomes higher at a lapping time over 20 seconds.

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The centrifugal barrel finishing is done at various charging ratios of media. The media is made of aramid fiber of meta type containing abrasive grains of SiC in #120 and its shape is cylindrical (2.5mm in diameter and 4mm in length). The workpiece is a cold finished carbon steel bar (S45C in JIS, 32mm in diameter) sliced by 10mm in length and its sliced surfaces are finished in grinding or in sand paper finishing. It is confirmed that the stock removal rate increases with the decrease of charging ratio, and also that the surface roughness and the edge radius of workpiece show the same tendency as the stock removal. The amount of stock removals of workpieces finished in a barrel shows two inflection points. The maximum point appears nearly at 50vol% in charging ratio but the amount becomes larger than the maximum point as the charging ratio becomes less than 20vol%.

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This report deals with the enlarging method of the recording area per a magnetic disk substrate by means of repressing the edge roll-off formed by polishing. The change of the edge shape in polishing process is experimentally examined in detail by measuring the edge shape in the accuracy of nanometer order with WYKO. To clear the formation mechanism of edge shape by polishing, the influence of the revolution of the polisher and the substrate on the edge shape formation is separately investigated and discussed. The edge shape of the substrate after non-electrolytic plating is found to be classified into the roll-up type and the roll-down type. The change of the edge shape in polishing process is divided into the edge roll-up formation type (RUF type) and the edge roll-down enlargement type (RDE type). In case of polishing under only the substrate revolution without polisher revolution and only the polisher revolution without the substrate revolution, the change of the edge shape becomes the RUF type and the RDE type, respectively. The low and high velocity polisher revolution under the normal polishing operation tends to be connected with the RUF type and the RDE type, respectively. The polishing of the RUF type can decrease the roll-down radius width, ΔR_X, of the substrate having the large roll-down, from ΔR_X_??_1.5mm to about 500 μm. for examnle.

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For measurement of the surface roughness, the techniques for simple treatment and proper evaluation of the measured results are generality required.In the measurement of the flat surface, the detection of diffuse reflex light is difficult because of the influence of the scattering light by finished scratch. Furthermore, the extent of roughness measurement is limited within narrow domain. Then the detection system of scattering light was investigated to be applicable between rough and smooth surface on the samples. By using the detection system of the moving surface for incident beam, the roughness measurement of the flat surface of the sample was examined by laser beam with new conpulsory vibration method. As a result, this method was found to he able to obtain the recording profiles of the effective treatment and proper evaluation.

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The study deals with 5-axis control tool path generation for machining sculptured surfaces by using a conicoid end mill. The sphere part of a ball end mill is in general utilized in case of machining sculptured surfaces having a wide variety of curvatures. However, it takes much time to machining such complicated sculptured surfaces with high accuracy because of the necessity of small amount of pick feed, which causes the reduction in machining efficiency. To solve this problem, a conicoid end mill was devised and the main processor of machining a swept surface was developed by use of paraboloid end mill, which is a kind of conicoid end mills. The adequate selection of cutting edge part allows a large amount of pick feed and a good surface roughness in finishing. As a result, it is experimentally found that the conicoid end mill has the potential of machining a sculptured surface with high accuracy and efficiency.

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The paper presents an analytical method which enables us to presume carbide tool wear quantitatively in turning operation with chatter vibration, based only upon the measured wave form of the vibration during the operation. The method consists of determination of stresses on both flank and crater wears using dynamic cutting models and the wave form, numerical calculation of temperature upon the wear surfaces, and computer simulation of the wear progress with a wear characteristic equation. The presumed results through the method are in good agreement with the experimental results. It is revealed that chatter vibration increases the flank wear, but decreases the crater wear. appreciably in both the wears. The increase could be attributed mainly to the large normal stress on the flank wear generated during the vibration, while the decrease would be resulted from the reduced contact time between chip and tool face due to the cyclic variance of the undeformed chip thickness.

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Atomic-scale mechanical processing of a layered crystal structure material, muscovite mica was performed using an atomic force microscope (AFM). The atomic scale processing phenomenon was evaluated from lateral force and surface atomic topographic changes caused by sliding. Above about 100 nN load, grooves were formed on the damage-free mica surface. The processing depth dependence on load was evaluated. The depth of the processed grooves increased with load. Processing lateral force estimated from the torsion of the tip beam was divided into plowing force and friction force. The plowing force is proportional to processed depth. Several cycles of mechanical sliding of the tip generated a 1-nm-deep groove by removing potassium from the surfaces which corresponded to the distance from the top surface of SiO₄ to the top surface of the next SiO4 layer beneath it. A groove with four steps of one-nm depth was processed by stepwise mechanical sliding. Atomic images of each step surface of the groove corresponding to the SiO₄ basal plane were observed. Then the letters NIT (scale 2000 × 600 × 1nm) was processed by mechanical tip sliding.

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Drill breakage is one of the major problems in small hole drilling with twist drills. Therefore, it is important to know the influence of drill shape on torsional strength. Because of the small diameter and complex cross section, accurate evaluation of torsional strength is very difficult. This paper presents the process for analyzing the torsional strength of a twist drill using the three-dimensional Finite Element Method (FEM). An FEM analysis is performed using a short cutting length model with constant web thickness. The analytical results are in good agreement with experimental results and the effectiveness of this analysis was proved.

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