To reduce the risk of tool breakage in high-efficiency machining, the shape of the cutter body was studied using structural analysis. The structural analysis was performed using finite element analysis simulation software MSC Nastran 2019 from MSC Software, and was evaluated in terms of Mises stress. As a result, it was found that setting an appropriate angle at the radial side of the insert near the restraining surface had the effect of reducing the stress on the cutter body when a cutting load was applied. The angle is between 30° and 45°.

the machining accuracy required for molds has become stricter year by year, but shortening the machining time is also an important issue. To break through, there are high expectations for 5-axis machining, and this paper describes a simulation related to the development series of special shape tools specializing in 5-axis machining. The use of the cutting edge and the development of the R size cutting edge in consideration of the cutting force are described.

For machining the flange of a jet engine case made of heat-resistant alloy, a CBN electroplated wheel that enables the supply of grinding fluid from inner side of the grinding wheel was developed. The developed grinding wheel has many radial slits in the base metal, which are covered by flanges on both sides. The grinding fluid is supplied from inside the wheel through the spindle. Furthermore, the grinding fluid is fed through the gap between the flange and the wheel and into the slit grooves from the root side of the radial slits, reaching the machining point by centrifugal force. A flatness of 0.02 or less and a surface roughness of about Ra 1.0 μm were obtained, and harmful affected layer couldn’t be observed within the machined surface.

Five-axis machining centers widely applied to machine mechanical parts, molds and dies have more error sources comparing with three-axis machines, and it is important to identify and compensate geometric errors in rotary axes to achieve higher machining accuracy. This study tries to develop a geometric error identification method of rotary axes based on cube machining test results. Cube machining test is a test method for five axis machining centers by machining a surface with several tool orientations. Height deviation of the machined surfaces are influenced by the geometric errors. In this study, a sensitivity matrix representing relationships between geometric errors and height deviations was obtained based on a mathematical model of a five-axis machining center. The geometric errors can be identified from the measured height deviations by using an inverse sensitivity matrix. As the results of simulations and experiments, it is clarified that although geometric errors can be identified based on the matrix, small measurement error yields large identification error in some cases.

As one of the new accuracy evaluation methods for 5-axis machining centers, the cubic-machining of 9 square faces on the cube is proposed. Each square face on the cube is machined at different tool posture. 9 square faces obtained by cubic-machining are affected by the geometric errors of the machine tool, and thus are confirmed to be accompanied by height differences and inclinations. So far, vertical height differences of machined surfaces have been discussed.

However, in addition to vertical height differences, machined surfaces have horizontal displacements and inclinations, which makes the evaluation of the machined surfaces more difficult. By applying 5 dimples as measurement points on each of 9 square faces, horizontal and in-plane misalignments can be evaluated. For the top surface of the cube, positions of dimples on the reference plane machined at a tool posture of 90° are simulated. The relative amount of displacement of the dimple positions was expressed by form-shaping function, and the structure error γ_yx was identified.

Most machining operations on 5-axis machining centers are not simultaneous 5-axis machining but indexing 5-axis machining. Therefore, a simple measuring method for the angle indexing accuracy on a 5-axis machining center was investigated. Specifically, angle indexing was performed by simulating cubic machining, in which nine cells are machined per face of a cube, at several combinations of inclination and rotation angles, and on-machine measurements were made using three reference balls and a touch probe.

Researches to develop a more efficient tool posture specification method for 5-axis machining are still very active. We thought that the use of spherical κ-curves would provide more efficient tool posture specification in 5-axis machining. The purpose of this study is to use tool posture specification using a spherical κ-curve in ball end milling on a 5-axis machine. The κ-curve is a smooth curve developed by Yan et al. The spherical κ-curve is a projection of the κ-curve onto the unit sphere. The tool posture is represented by two angles. Therefore, posture control is performed by mapping a point on the spherical κ-curve one-to-one to the tool posture. The spherical κ-curve does not cause unexpected oscillations. Therefore, the tool posture changes very smoothly without unnecessary motion. We conducted experiments using the proposed method on Pocket NC V2-10. As a result, we confirmed that tool posture specification using spherical κ-curve is feasible. In the future, it is necessary to devise a more efficient method for generating the spherical κ-curve.

In recent years, special shaped tools with curved cutting edges have been introduced in 5-axis control machining. In machining with special shaped tools, the positional relationship between the command point and the cutting point changes depending on the tool posture, so the widely used tool center point control as an interpolation method for the command point cannot guarantee machining accuracy. Ueyama et al. proposed a new interpolation method that refers to the cutting point of an oval tool, which is a type of special shaped tool with a curved cutting edge. In this study, this method is extended to be applicable to other tools with curved cutting edges. Machining simulations were performed on an aluminum alloy (A5052) flat plate using four types of special shaped tools (barrel type, oval type, lens type, and tapered type) to evaluate the machining accuracy. Consequently, it was established that the average machining accuracy improved by approximately 99.4% compared to tool path interpolation based on tool center point control.

To achieve high-quality and high-efficient machining without depending on the skill level of operators, standardization of process planning is strongly desired. Because operators' decision-making process is complicated, interviews with skilled operators are difficult to acquire the skills related to process planning. On the other hand, in recent years, electroencephalography has attracted much attention to obtain brain wave as a key to estimate operators' decision-making process. Therefore, electroencephalography is conducted when understanding a lot of mechanical drawings with different difficulty level in this study. The degree of cognitive load is visualized by calculating the power spectrum of the brain wave data. Then, a machine-learning model is built based on the common spatial pattern method to classify the drawings according to the difficulty level. The inference results show a possibility to identify a high cognitive load area when understanding mechanical drawings and to establish a key to find an important area for the interviews to acquire the skills.

It is practical to use past machining cases which include implicit machining know-how to efficiently realize computer aided process planning (CAPP). In the previous study, a CAPP system is developed based on machine learning to determine suitable operation parameters for die and mold machining. The system employs voxel and infers tool path pattern for each voxel. However, there is a problem that the data size of voxel increases with the resolution. On the other hand, graph could solve this problem by representing only the surface efficiently. Therefore, this study aims at developing a CAPP system based on graph neural networks (GNN) for die and mold. Graph data is generated from mesh data, and tool path pattern as an operation parameter is inferred by node classification of GNN. From the result of case study, it is recognized that the inference using GNN is effective to determine operation parameters reflecting the implicit machining know-how.

Water Jet Guided Laser (WJGL) processing is a micromachining technology that uses high-pressure thin water jet (<φ100 μm) as a waveguide for the processing pulse laser. As the laser energy is delivered to the workpiece by total internal reflection at the boundary of the water jet and the air, water jet stability is of great importance in maintaining effective and quality processing. However, other than hydrodynamic instability, it is known that there are disturbances on the water jet that are caused by the laser incidence at the jet orifice, which is called laser-induced disturbances. In this report, we observed the laser-induced disturbances in a pump-probe manner with high spatio-temporal resolution by utilizing picosecond laser illumination synchronized with processing laser. The instantaneous water jet morphology was successfully visualized and the observed disturbances showed high reproducibility over pulses. The disturbances were also caught flowing at the jet velocity, which is a direct proof for the model of laser-induced disturbances.

This paper proposes a novel three-dimensional measurement technique enables to measure structures to which conventional optical methods are not applicable. In recent years, precise components with micrometer-scale structures have become widespread in various fields, such as optical elements and microfluidic chips. At the same time, the demand to measure these three-dimensional shapes with sub-micrometer accuracy is expanding. While optical shape measurement methods such as confocal laser scanning microscopy have the advantage of being non-invasive and getting into the micrometer scale region, they are difficult to measure steep and smooth slopes where reflected light cannot be acquired. In this study, we focus on fluorescence as a measurement principle that can acquire signals independent of structures and propose a method to estimate the surface position by confocal detection of the fluorescence emitted from the object itself. We named this technique fluorescence response-based optical probing (FROP). In this paper, we construct a theoretical signal model considering excitation light attenuation and detection volume comparing it with finite difference time domain (FDTD) simulation. Through the measurement based on the proposed model, its applicability to inclined surfaces was verified.

In this study, we propose a measurement system designed to compensate for the orthogonality of a planar stage and demonstrate its basic principles. The proposed system consists of a single grating scale placed diagonally across the stage and two interferometers aligned in a retro configuration, which are sensitive only to the stage displacement along the optical axis. The measurement direction is determined with high precision by the pitch of the grating and the optical wavelength of the interferometer, allowing for accurate orthogonality correction. Our experiments demonstrated that interferometers aligned in a retro configuration can accurately measure the stage displacement component along the optical axis. In discussion, we identified two key factors to evaluate orthogonality: (1) the alignment accuracy of the retro configuration and (2) the pitch accuracy of the grating scale. These factors are essential to ensure the high accuracy and reliability of the proposed measurement system.

On-machine measurement using touch trigger probes can be performed on a single workpiece, including 3D geometry, using multiple measurement methods. If the measurement results differ, this will lead to uncertainties in the machining process. The aim of this study is to clarify the influence of the measurement method on the measurement results by comparing the measurement results of several methods of measuring S-shaped machined specimens, which are described in ISO 10791-7 as informative test.

Chatter vibration in cutting deteriorates machining efficiency, cutting tool life, and surface quality. Many reports have revealed that the chatter vibration can be suppressed by analyzing the dynamic stiffness of the cutting tool and the workpiece. However, since the apparatus required for the analysis is generally expensive, it seems that the analytical approaches to prevent the chatter vibration are not widely used among machine shops.

Therefore, this study reports an inexpensive and simple method for suppressing chatter vibration.

Chatter vibration generated during machining, such as turning and milling, causes deteriorating finished surfaces and tool chipping, and consequently affects machining accuracy and productivity. Numerous studies and technological developments have been conducted on the clarification and suppression of chatter vibration. Recently, multitasking machines have become widely used, allowing for the easy machining of mechanical parts with various cross-sectional shapes by controlling the main spindle and tool spindle. It is necessary to verify the characteristics of chatter vibration in turn milling. However, since both the main spindle and tool spindle rotate in turn milling, it is not easy to apply a dynamometer or an accelerometer to detect vibration. In this study, the effectiveness of detecting chatter vibration by measuring the sound during machining was studied and compared to detection using an accelerometer. As a result of the analysis of the sound frequency, changes in the power spectrum caused by the generation of chatter vibration could be detected. Although the rate of change of the signal is lower with a microphone than with an accelerometer, detecting chatter vibration by machining sound is effective.

Since 5-axis machining centers have rotating axes, there are geometric deviations. Therefore, Low machining accuracy is a problem. Although there were tests to calculate geometric deviation thorough machining, rotary axis is machined after indexing. This report, mill turning while rotating the A-axis, we investigated relationship between geometric deviation and shape deviation. Through simulation and experiment, the geometric deviation transferred to the shape deviation differs depending on the processing position.

In this study, we have developed a new prototype measurement device that can simultaneously evaluate displacements in some directions, and that does not change measurement accuracy depending on the measurement position, in response to three-dimensional feed axis motion.The prototype measuring device has two displacement sensors, allowing simultaneous measurement in two directions.An evaluation experiment was conducted by circular motion, using the prototype measuring device and DBB. As a result, the prototype measuring device confirmed the errors due to over-compensation of the backlash compensation and quadrant glitch compensation on the (+) side of the Y-axis motion direction change point. However, some problems with low measurement accuracy occurred on the other points.

Major error sources in on-machine measurement on a machine tool are error motions of linear axes. As linear axis error motions can significantly vary due to the environmental thermal influence, it is important to periodically perform a verification test, similarly as for coordinate measuring machines (CMMs), to monitor the variation in linear axis error motions. By measuring a rectangular square by a touch trigger probe, this paper presents a scheme to measure linear positioning errors, angular errors, and squareness errors of linear axes. On a vertical machining center, the present test was performed three times over six months, to observe long-term variation in linear axis error motions mainly due to the environmental thermal change.

By high resolution of machining, on-machine measurement and in-process measurement of machining tool position are needed. Image measurement is tried to use for on-machine measurement of machining tool position. However, when we use image measurement, machining tool is hidden in case that obstacles such as cutting chips and sparks are generated. To overcome this problem, we propose to use time sparsity of obstacles generation. We detect obstacle using time difference of pixel value and complement hidden area by machine learning.

A variety of techniques, including the use of radio-frequency (RF) devices, are currently used skin care. To evaluate the skin care effects of home RF beauty devices, it was compared and discussed with the in vivo effects of commercially available skin care cosmetics. Thirty-three women aged 30-60 years participated in this randomized, controlled, split-face trial. The study involved a 7-day trial with 3 repeated measurements. One side of the face was randomly selected as the experimental group, and treated with a RF beauty device, for comparison, the other side was used as the control, and treated with anti-aging cosmetics. Moreover, treatment safety, skin wrinkles, hydration, radiance, elasticity and color were evaluated. All participants completed this clinical Trial.

The experimental side showed the statistically significant improvements in wrinkles, skin radiance, color (p \ 0.05), compared to the anti-aging cosmetically treated face side. It could conclude that the home RF beauty device is safe and effective for rejuvenation, furthermore, the device is more effective than the commercially available anti-aging osmetics.

In this report, the history and methods of dental and oral health and dental/oral cleaning are briefly described, and the structure and function of portable water flossers for oral cleaning are investigated and compared. The basic structure of portable water flossers was also investigated. The main portable water flossers on the market were compared with the data published on Amazon.com, a major sales website, for comparison purposes. The emergence of more compact and lightweight portable water flossers will undoubtedly help people to maintain healthier oral and dental health and lead to a safer and more secure life.

In the drawing of stainless steel and nickel-based heat-resistant alloys, progressive and transfer press forming with continuous plastic deformation processes involves repeated deformation of the material and intermittent contact and release between the die and the material to be formed, resulting in complex heat transfer. Therefore, lubrication and protection of the contact surfaces with oil is important for the control of the geometry of the final products and for extending the life of the die. In general, the performance required of the machining oil used in the drawing process is strict, and chlorinated press oils have been used for many years. In this process, temperature control of the contact interface is important to achieve the desired performance of the processing oil and to control the final product quality. In this study, a non-contact temperature monitoring method for the die surface and the material surface during transfer pressing was developed and its accuracy was evaluated.

In recent years, magnesium alloys and aluminum alloys have been attracting attention as a way to reduce the weight of car bodies in the context of energy conservation and a decarbonized society. However, it is known that magnesium alloys have very poor workability due to the anisotropy of their crystal structure. Cases and containers with few seams are formed by deep drawing. Since plastic deformation is difficult at room temperature, warm forming is generally performed. However, dies and punches require heating and cooling devices. In the present study, focusing on frictional heat generation during friction stir welding, warm deep drawing of magnesium alloys was attempted using a punch incorporating a frictional heat generation jig. It was found that heat of 400 °C or more could be obtained in a few minutes of friction processing time. It was also found that deep drawing of magnesium alloys is possible with a punch in a warm state of 200 to 300 °C.

Corrugated cardboard, known for its high cushioning properties and strength, is widely used in transportation. In the present study, we focused on the cross-sectional structure of cardboard with voids. Aiming to produce a lightweight, high-strength corrugated cup, we formed the drawn cup with a void structure and evaluated its strength. In the experiment, test material used was the mild carbon steel sheet SPCC, and pure titanium sheet TP270. The disk blank had a thickness of 0.3 mm and a diameter of 80 to 90 mm. The special die used was the roller ball die (RBD) with steel balls tightly packed into the shoulder of the die. It was used in combination with a normal die. The diameter of the steel balls ranged from 6 to 8 mm. The punch had a corner radius of 4 mm and a diameter of 39 mm. Both the punch and die underwent conventional heat treatment. The formability of the clad cup was investigated, including the adhesion between the constituent cups, residual stress of the cups, compressive strength, and plate thickness distribution. The drawn cup did not break, and a corrugated layer was formed uniformly on the cross section of the cup. Furthermore, the maximum sheet thickness reduction rate was approximately 10 % or less. It was also found that it was possible to form the drawn cup with a void structure that exhibits high adhesion and high compressive strength.

The grinding wheel wear reduces the machining accuracy and causes the residual stock removal of workpiece after the grinding process. One of the causes of the grinding wheel wear can be mentioned the grinding resistance. On the other hand, it is known that the grinding resistance depends on the stiffness of the grinder. The grinding wheel wear may be depended on the stiffness of the grinder if the grinding resistance by the stiffness of the grinder changes. Therefore, machining accuracy will be improved if the workpiece support stiffness can be properly controlled. This study aims to investigate the effect of the difference in the workpiece support stiffness in cylindrical grinding on grinding wheel wear. As a result, it was clarified that the difference in the workpiece support stiffness affects the normal resistance, grinding wheel wear and decreased amount of depth of cut in plunge grinding. Moreover, difference in the normal resistance affects the grinding wheel wear.

This study focused on the temperature inside the cover of a grinding tool to detect and control in-process machining errors in the grinding process. As a result, it was confirmed that the temperature inside the cover responds relatively quickly to the depth of grind. Two feedback systems, one to control the flow rate of the grinding fluid and the other to control the tool speed, were developed by monitoring the temperature in the cover, and in-process control according to the temperature detected in each system became possible. The result that the surface roughness and roundness were almost same in with or without each control system proves dynamic thermal control of grinding point is available.

In this study, we propose a model-based process simulation to estimate grinding force and a parameter identification method for ultrasonic assisted grinding. The proposed grinding model consists of a macro grinding model based on a mechanistic force model and a micro grinding model the performs z-map simulation considering the movement of abrasive grains. Grinding experiments and simulations were conducted on quartz glass to verify the proposed method. In the grinding experiments, the grinding force was evaluated when the feed directions were changed between normal to the z-axis, ramp-up, and ramp-down in shoulder machining using the grinding pin. The results of the verification experiments confirmed that it was possible to quantitatively estimate the reduction in grinding force of the bottom surface of the tool due to ultrasonic oscillation.