The trochoidal gear pair consists of two elements. One is roller gear or pin gear, and the other is cam gear. Generally the roller center path on the cam gear makes a trochoidal curve, and the profile of the cam gear is parallel to the trochoid. In this report, first it is proved that this mechanism satisfy the gear theory, i. e., a constant velocity transmission is achieved, theoretically. Next some variety of the kind of this mechanism are shown and the nomenclatures are defined. The basic formulas are derived for the sake of optimal design of the mechanism.
A non-contact sensor which can continuously and simultaneously detect the normal direction and the position of a measured point is a base of an autonomic high speed measuring system. In the 1st report, the sensor-element and the sensor are designed and performance of the element is clarified by computer simulations. Then this paper deals with the method for determining a normal direction and a position by using calibration data, which is based on linear interpolation method, and a development of the sensor-element. Also, performance of the developed sensorelement is investigated by basic experiments. The following three issues became clear from the experiments. (1) The sensor-element can detect a normal direction in the range from 45.0° to 45.0° and detect a position in the range from 2.7 mm to 6.0 mm for a diffuse surface. (2) For a specular surface, the range of a detected normal direction is restricted from -7.5° to 7.5°. (3) The sensor element has the accuracy of 3 μm with regard to detecting a position and the accuracy of 0.18° with regard to detecting a normal direction for a diffuse surface. In addition, it became clear that the simulation results shown in the 1st report are similar to the experiment results, so that validity of the simulation is confirmed.
The thermal behavior of a machine tool is more influential on the machining accuracy than most of the other factors, especially when the machine tool is put under actual operating states. This paper deals with a new practical scheme which is applicable to Finite Element Method(FEM) for dynamic thermal analysis of machine tools having parts with relative motions. A case of fixed base and moving table is taken into consideration for a case study. A heat source is fixed on the upper surface of the table which moves over the base. During the finite element analysis, interpolations are introduced to match the mid-results of the nodal temperature values between the calculating steps. From the results of the case studies carried out under several moving conditions, it is proved that the scheme is effective for the dynamic thermal analysis of machine tools.
Constructing a CAD system for producing CAD models from a master model is important to style design. This paper describes curve fitting onto the measured point data of a master model. The point data were measured with a non-contact 3-D digitizing sensor, and a 4-degree non-uniform B-spline curve was fitted onto them. In the process was used a non-uniform knot vector determination method which took account of curvature as well as method of calculating curve fitting errors in the normal direction. Comparing the uniform B-spline curve with a curve obtained in the new fitting methods was simulated with a computer. So was the influence of the measured point data containing measurement errors. Control points were calculated by B-spline curve inverse transformation based on the least-square method. Then inspection experiments were performed by use of a master model having freeform surfaces. As a result of the experiments, it can be concluded that the new fitting methods can help reduce the 404 measured point data in the experiments to 23 control points and 27 knots, and that the B-spline curve calculated in the new methods can he fitted onto the measured point data with high accuracy in the whole range.
As explained in the 1st report, a new type of laser cutting machine for the apparel industry has been developed. With this type, since a slight error is magnified, high precision in parts, assembly and optical alignment is required to assure cutting accuracy. However, the high precision results in high cost. To prevent the cost increase, a new method of error compensation using software was introduced. During installation, the error vector is measured throughout the cutting area, and this error vector is subtracted from the reference position. This error compensation method proved to be quite effective in assuring cutting accuracy.
This paper deals with the heat generation influence of motor and the effect of shaft-bore cooling on a motor integrated spindle. With respect to the temperature distribution of spindle interior, the results of FEM heat conduction analysis and heat flow calculation agreed with the measurement of rotating test. Therefore according to the estimate on the influence of motor heat generation and the effect of shaft-bore cooling for temperature distribution and heat transfer, the preload increment and displacement, can be calculated more accurately.
Efficient fine finishing of optical glass has been conducted by using a newly-developed setup which realizes the finishing of the non-contact type polishing with tin wheel floating by the effect of fluid lubrication. The polishing is made by using an electrophoresis phenomenon of fine grain in the water. when the electric power of DC voltage is supplied to the tin wheel rotating in the polishing compound, the grain concentrates on the wheel surface and causes the grinding action in a sense to the workpiece surface Experimental results show that the stock removal rate increases after first decreasing with the applied potential. It is found, however, that applied current intensity has little effect on the stock removal. The characteristics of polished surface have been exmined by AFM. The microtopography of the surface polished with fine abrasive grain indicates that the surface roughness of the order of nanometers is obtained even in the case that high voltage is supplied.
The amplification of forced vibration in plunge-cut cylindrical grinding is analyzed theoretically and experimentally. In machining works of a certain size range, the forced vibration coming from the gear pump in a specific grinding machine is found to increase gradually or rapidly after start of grinding. This paper discusses a general mechanism of the vibration amplification as experienced with the case and methods of suppression are explained. The effectivity in suppression is confirmed experimentally.
The fabrication of three dimensional models using rapid prototyping system has been operated to make test parts not only in industry but also in medical fields in which a physical model needs to he realized from data stored in a computer. This process is paid much attention, as it is able to create a physical shape easily independent of the complexity of the model. Although the process is easier than the conventional machining, the strong demand is in the improvement of part's accuracy. The distribution of power density is one of the main factors that defines elemental unit shape of the model, and consequently it affects part's accuracy. This paper analyzes the laser optics with single and longitudinal multimodes lasers. According to this analysis, it reveals that, in the case of longitudinal multimodes laser, a difference occurs between each wave length beam waist, and the power density distribution results in the mixture of two wave length beams. This paper discusses the method to obtain the precise power distribution of a conventional system, and an optical system design is also proposed to minimize the difference of two beam waists.
Up to now metallic corrugated diaphragms are usually formed from the sheet material using a hydraulic bulging, mechanical press and explosive forming. This paper describes on the comparison with the characteristics of the new forming method by ball rotating with thrust load for the other process. A product by this new method is of the 5111k rank or better in linear pressure characteristics compared with those by another manufacturing methods. NIoreover, the product is very cheap in cost and economizes working force.
This paper describes the evaluation results of molybdenum conductors formed by laser-induced CVD using thermal decomposition of molybdenum hexacarbonyl as a material gas. In order to apply this technique to LSI products, it is very important that the conductors deposited on LSI chips have sufficient reliability. From the fusing test, the applicable current density was found to be about 3 × 106 A/cm2 which is sufficiently high compared with the maximum current density, 1-3 × 105 A/cm2, for practical use. Molybdenum conductors, after laser annealing. endured a heat cycle test 70 times without a change of resistance. And, these conductors did not change resistance for 1 000 hours when a current density of 1.3 × 106 A/cm2was applied in a 125°C atmosphere. These results suggest the possibility of application in LSI products.
A new type of externally pressurized infinite stiffness gas bearing is proposed. This bearing is constructed with a movable bush, a spring plate and two restrictors in series. This paper describes the bearing construction applying to a circular thrust bearing, working principle and analysis of the bearing performance. Calculated results show that the bearing has infinite stiffness in the neighbouring region of designed load. This is caused by the fact that the spring stiffness is linear but the change of bearing pressure is not linear to the shaft displacement.
The skilled machinists evaluate exactly the cutting state. Therefore, the study on the modeling machinist's thinking process is progressed recently. In this paper, a rational way for the system monitoring the cutting state in turning is discussed. The proposed system consists of the fuzzy integral model which evaluates the individual cutting trouble (e.g. tool life, chatter, chip controllability) and the neural network which applies to the model depending on machining conditions. The fuzzy integral model is systematized by the machinist's evaluation to individual trouble. The neural network is structured by the measure of information that compared the evaluation of machinist with fuzzy integral model. The validity of this system was confirmed by the experiments under various cutting conditions in this study.
This paper describes the conditions, especially for bonding time and temperature. Assuming that bonding of Cu depends on its recrystallization, the process can be estimated as follows. First, the temperature change of bonding parts is calculated by a simulation using F1-M. Conditions for the upper energy limit are given so the temperature does not exceed melting point. Then using Krupkowski's formula for recrystallization growth rate, constants are sought by the measurement of isothermal changes. From the formula and temperature change, the recrystallization change is calculated as the accumulation of growth in a short time. Conditions for lower energy limits are given as 90% of recrystallization rate. This hypothesis is verified by the fact that the conditions derived from the above calculation are in good agreement with the conditions of the experiment bonding Cu wires to Cu lands of printed circuit boards by parallel gap bonding, . As a result, it is now possible to choose a suitable bonding method and the conditions, not relying on experience OF trial and error.
The paper presents a new method for preventing chatter vibration in end-milling operation. Natural contact length between chip and rake face of end mill is reduced artificially by grinding. It is found experimentally that end-mill with the reduced contact length enables to prevent onset of the vibration and raises the stability threshold up to 70% in lower cutting speeds. Computer simulation of the chatter occurrence is also carried out, in which three models of dynamic cutting with variable undeformed chip thickness and energy methods for predicting the cutting force are developed and utilized. Through the simulation, it is revealed that the reduced contact length suppresses the cutting force variation when some disturbance is introduced in undeformed chip thickness, ilence it would reduce excitation of the vibration system. The suppression of the force vibration could be attributed to the stress characteristic of friction on the restricted rake face.
Aluminum nitride (AIN) is expected of useful electronic material because of properties of high temperature stability, chemical stability, high thermal conductivity, high sound velocity and so on. For purposes of fabrication and control of film crystallinity and orientation at low temperature, AIN film was prepared by dual ion beam deposition method. It was found that the bombardment of nitrogen ions was very important for reaction between aluminum and nitrogen, inc.1 that a good oriented AIN film could be formed at room temperature by the precision control of the bombardment of low nitrogen ion energy (100 eV). For stoichiometric AIN, the c-axis orientation depends on the nitrogen ion beam current density and becomes better with the increase of nitrogen ion beam current density. The c-axis orientation of AIN film by this method was independent of the kind of substrates and temperature.
Surface alloys which have composition similar to stainless steel are produced on mild steel substrates by traversing the substrates under electron beam irradiation. Chromium and nickel powders are fixed onto the substrates with water glass. An electro-magnetic deflection system oscillates the beam as if its cross section at the substrate surface looks like a rectangle. A mathematical model is constructed which describes diffusion of alloying elements from powders on the surface into an alloyed layer. It is assumed that the alloying elements diffuse instantaneously into an alloyed layer. The calculated results on the concentration distribution show good agree-ment with experimental results. Anti-corrosion characteristics of the alloyed layers are evaluated by anodic polarization curves measured along Japanese Industrial Standard G 0579. The anodic polarization curves of the alloys were similar to the standard curve of a stainless steel, SUS 304, but show somewhat higher peak current density for passivation. The concentration of water glass in powders should be in the range of 0.8 to 2% to attain good and stable anodic polarization curves. The anodic polarization characteristics are better when the density of chromium and nickel is higher.