This paper describes an NC Simulator GP / SIM based on a newly proposed 3 D-solid model. The main purposes of GP / SIM are to precheck an NC data by using the simulation techniques and then to make the expected production period shorten. GP /SIM proposes a new theory of a hierarchy solid modeling (CSG model) and also developed new algorithms to simulate the aspect of machining. Therefore, GP / SIM is able to verify throughout the machining process beforehand. After the development of the system, whole of algorithms and theories were confirmed on engineering work station and real machining shop.
In this report, the new encapsulation technology for electronic devices, such as IC, has been investigated using the injection moulding process to substitute for the transfer moulding method conventionally used so far. And the analysis has been carried out utilizing the computer simulation program covering cavity filling behavior to examine the quantitative relationship between the deformation and/or breaking-down of gold wires bonded with IC chips and processing factors, such as mould geometries, injection conditions and physical properties of resin encapsulants. As a result, the new technology to obtain good products preventing gold wire deformation within the practical level has been established concerning various kinds of cold-runner and hot-runner moulds. Furthermore, the new type of the injection moulding machine developed for the purpose of the resin encapsulation has been described in this report.
The heat generated in one-pass surface grinding causes the convex deformation of a workpiece. Therefore, the ground surface represents a concave profile. In this study, the thermal deformation of a workpiece attracted by magnetic chuck is investigated both theoretically and experimentally, and the necessary constraining force that completely constrains the convex deformation is computed. The main results obtained are as follows : (1) The ground surface attracted by magnetic chuck represents a concave profile. (2) The attraction force of magnetic chuck diminishes the, convex deformation. (3) When workpiece thickness to length ratio H/L does not exceed about 1/8, two concaves are formed by both ends of ground surface. (4) When a workpiece of HXL=20×80 (mm) is ground under a condition of 10μm down feed, the necessary constraining force is about 8 MPa.
The paper is concerned with the finishing characteristics by a new finishing process employing Liquid-Bonded Wheel with high finishing pressure varying from 0.1-0.6MPa. The bond strength of this wheel is smaller than those of any other grinding wheels, resulting in the decrease of the removal unit. The number of active abrasive grains in this process is however more than that in conventional finishing process. And the removal rate increases in proportion to the finishing pressure, for all load is subjected to abrasive grains under even high pressure. Consequently both a high removal rate and a very smooth surface can be achieved at high finishing pressure. A removal rate of about 7 μm/min and a surface finish of 0.05 μm Rz is obtained for the finishing of silicon monocrystal wafers with pressure of 0.4 MPa by using SiC grains (mean diameter=5μm) in this process. Moreover, the removal rate increases in proportion to the finishing speed too under even high speed up to 30 m/min in this process, for the strong cohesiveness of abrasive grain in this wheel against the centrifugal force. And further, it becomes clear that type of polishing fluid, type of abrasive grains and grain size effect on the finishing characteristics in this process
A very practical simulation system for the establishment of grinding operation standards has been developed in which many practical parameters in actual grinding operations are considered. This computer system simulates such grinding phenomena as dressing, chip geometry, active grains behaviors, wheel surface conditions, wheel wear, grinding force and power, surface roughness, temperature and burning of workpiece, loading on wheel surface, and spark-out grinding. The system can display the simulation results as a graph including both the time-dependent results and the effects of various parameters, having the same effects as many grinding experiments. It is also capable of selecting the optimum grinding wheels and conditions for the grinding operation under the given constraints by exchanging automatically the combinations of the operation parameters and their values. Thus, with the aid of the system, grinding operation standards are able to be established.
This paper deals with a ball-nose end mill simulator. It proposes a simulating method of a cutting force for a part of ball.This method is as follows. By using approximate functions for a shape of a cutting edge, a phase difference and a helix angle of the cutting edge are represented by means of formulas and calculated. Therefore a cutting area is given.The cutting force becomes the product of the cutting area by a specific cutting force which is determined from experimental values of the cutting force. In accordance with this method, it is shown that the cutting force is simulated.
This paper presents some experimental results on mechano-electrochemical polishing with applied voltage and suggestion on the mechanism of this polishing. In polishing of ferrite with stannum plate and diamond-slurry-mixed hydrochloric acid to build up the inner cell, electrochemical action adds to mechanical action. This electrochemical action is accelerated by applied voltage between stannum plate and ferrite. In this case, stock removal rate of ferrite is increased to four times that without applied voltage or to tweentieth times that of mechanical polishing. Morever, surface damaged layer of ferrite is reduced to one tenth that of mechanical polishing.
In turning of the sintered carbon, the influence of the varying depth of cut and feed rate on a tool life and a chip formation mechanism are shown experimentally. The tool life is a minimum at a given depth of cut and increases with increasing feed rate. These singular results of the tool life are discussed from chip particle size, vibration frequency and amplitude, crack extension and work surface roughness. The obtained results are as follows. At the larger depth of cut and feed rate, the vibration amplitude is larger so that the rate of the large chip particle increases and the work surface roughness is larger. On the other hand, at the smaller depth of cut the work surface roughness is larger because of the deeper crack extension. The tool life depends on the work surface roughness, which is relevant to the contact numbers between tool clearance face and work surface.
It is customary to support the workpiece with dead-centers in high precision cylindrical grinding. Then the geometrical deviations of cone centers and center holes, and their misalignments have an influence on the roundness of ground surfaces. It is known that the misalignments and geometrical deviations of center holes do not influence the roundness of ground surfaces with the accurate and cheap steel balls in place of cone centers. But few reports concerned about the characteristics of the ball centers were found. In this paper, experiments on the axial and radial stiffness were performed, at the contact parts between balls and center holes. The obtained main results are as follows : (1) The relationships between the elastic deformations and the loads are hysteretic. (2) The axial and radial contact compliances are from 0.002 5 to 0.006 μm /N. In the ball centers, the stiffness is smaller than that of the cone centers, but the variances of stiffness are smaller than these too. (3) The stiffness decreases according to the increase of the circumferential waviness of center holes, and to the decreases of ball diameter and Young's modulus. (4) The ellipsoidal component of center holes decreases the radial contact stiffness remarkably.
The method proposed inserts periodic, decelerated feed at infinitesimal width into continuous feed at a certain pitch (hereafter referred to as intermittently decelerated feed). An attempt was made to break chip produced from drilling by intermittently decelerated feed. It was found that the chip is broken into easily disposable smaller pieces by optimizing the interval and the rate of feed deceleration. The axial deviation of hole in intermittently decelerated feed is lower than that the continuous feed. As a result of research on round of hole with work material S 45 C, no difference in round of hole was observed in intermittently decelerated feed compared with continuous feed. The tool life of intermittently decelerated feed in drilling is longer than that of continuous feed.
This paper discusses the product data flow in a manufacturing system for machined parts. Through consideration of this product data flow, a form-feature modeling system is developed for the generation of a product model. The resulting product model contains descriptions of these form features and their dimensions to datum surfaces. For functional machined parts, the functional form features used by designers and the manufacturing form features used by process planners are nearly identical. Currently, machined part designers produce a representation of the information about the form features and their dimensions, which usually is not in an appropriate form for input into automated process planning systems. With the system described in this paper, both the designer and the process planning system may share the same description of form feature and dimension information. The dimensioning information is automatically converted into the appropriate form for production. Machined part features output by the system are dimensiond and described appropriately for direct use in production systems. With such an integrated system, the difficulty in converting product design to process plans is eliminated.
Recently, discrete parts manufacturing systems have a tendency to turn from the mid-variety and mid-volume production to very small batch production according to a great diversity of marketing needs. In practical shops, it is required to establish an effective very small batch production system. The objective of this research work is to propose an effective operation method for the very small batch production in machine shops. It is shown in the research that a dynamic process planning system is necessary to operate the very small batch production efficiently. The dynamic process planning system is a knowledge-based system that is able to integrate job-shop scheduling and process planning. This paper defines the characteristics of very small batch production, describes the modelling of DPP system, and shows the evaluation result of DPP by using simulation.
This paper analytically deals with development of a hammering machine contained in function of shock isolation with a work operating manipulator. The isolation method is called “Elastic suspension with synchronously repetitive counterblow”. A body of the machine keeps to set rigidly and an anvil and a work holder are suspended elastically for shock isolation. An operating arm necessitates very low stiffness to the impact direction for isolation of impulsive force and high stiffness to the orthogonal direction for keep good moval responsibility. If the setting position of the arm takes place the position that the work contacts to the anvil head without press together and the ratio of the damped natural half period to the period of excitation is 2 to the anvil system and 2/5 to the work holding system, respectively, the hammer and the anvil collide to the work from upper and under direction as counterblow at the static equilibrium position of the work. Then change of the work thickness doesn't perturbed the counterblow. Feeling of the work operation becomes as good as that of the rigidly setting anvil. The mass ratio of the anvil and the work to the hammer take place more than about 15 and less than about 1 for control of reduction of the impact activity, respectively.
The paper proposes a computer-aided 3-dimensional shape measuring system which consists of 5-directional measuring machine installed with a newly developed non-contact distance sensor, and processors provided to transform the measured distance data to coordinates then also to construct entire mesh point data of the object workpiece. The distance sensor is based. on an astronomical telescope typed optical system, equipped with laser tube and one dimensional CCD set horizontally on the optical axis. The device has following features : (1) wide range of measuring distance, (2) high measuring rate, (3) linear measuring characteristics, (4) less hidden effect and (5) compact size. The system is one of the sub-systems in a more comprehensively computer-aided marking system which, also having been realized in the same period, executes automatically all processes concerning to marking operation for large sized workpiece produced by casting and / or forging. Some test results of the measurement are presented constructing mesh point data model of the entire surface for a few typical work - pieces.
This paper describes a method of three dimensional coordinate measurement in which the coordinates of a moving transmitter are calculated using ultrasonic distances of some fixed receivers to the transmitter. First, to realize motion measurement, the four-point method is introduced which uses four receivers for reducing the coordinate calculation time instead of three receivers of the conventional triangulation. The measuring speed by the method is 6.5Hz. Secondly, an ultrasonic coordinate measuring machine is introduced. It is shown that profile measurements are possible without using any motion mechanisms. Lastly, a method is discussed of expanding the measuring space by uniting some small spaces measured by four receivers. As an example, a 1m×1m × 1m space is made of eight small spaces using thirteen receivers.
This paper describes the sensitivity of vibratory rate gyro as a sensor of angular velocity, which is detected by phase difference method. In a vibratory rate gyro, subvibration occurs due to the Coriolis' force, when the gyro is rotated around its longitudinal axis. The sensitivity depends on the angle between a straight line connecting the position of detector for subvibration to center of the gyro and the direction of mainvibration, and increases as the angle increases up to 90 degrees. Also the sensitivity depends on the difference between the two resonance frequencies of main- and subvibration, and increases as the difference becomes smaller.
It is important for the strength design to clarify the impact strength of roller chains because they are applied to the repeating impact load for chain drives. Firstly in this study, the relation between the repeating impact energy and the number of repetitions to impact failure. In the next step, the distribution of the failure sections is exmained. They are compared with the results of the repeating impact test of roller link and pin link. Further, the effects of the number of links on the repeating impact strength is investigated, and studied statistically. The obtained results are as follows : (1) The results of repeating impact test of roller chains indicate that the repeating impact strength reduced as the number of links are increased. (2) When roller chains are applied to higher repeating impact energy, they are a failured in pin link-plates and in the case of lower ones, they are a failured in roller link-plates. (3) The repeating impact life distribution could be estimated statistically by using the life distribution of single roller link and pin link..
Recently, the gear breakage and the noise due to the repetitive impact load in the lightly loaded gear train became one of big problems. For the theoretical analysis of this problem, actual contact characteristics of a pair of gear under lightly loaded is necessary. In this paper, the exact contact characteristics were obtained experimentally. Actually we obtained, spring characteristics and damping characteristics for the ideal condition, misalinement condition and double flank meshing condition. The result of lightly loaded gear pair has nonlinearity and the smaller values of contact characteristics compare with gears which used under heavy load for transmit power.