Process planning is well known as the key toward achieving highly efficient machining. However, it is difficult to standardize machining skills for process planning, which depend heavily on skilled operators. Hence, in a previous study, a computer aided process planning (CAPP) system using machine learning is developed to determine the operation parameters for finish machining of dies and molds. On the other hand, in rough machining, it is assumed that some machining operations are conducted sequentially using a respective tool according to the workpiece shape, which induces a much higher complexity in process planning. Therefore, in this study, machine learning is adopted to determine operation parameters for rough machining. The developed CAPP system converts the removal volume into a voxel model and infers a machining operation for each voxel. The inferred machining operation is visualized using different colors and identified corresponding to the voxel. Finally, the removal volume is classified using three different machining operations. However, machine learning is said to have a critical problem in that it is difficult to understand the reasons for the inferred results. Hence, it is necessary for the CAPP system to demonstrate the certainty level of the determined operation parameters. Thus, this study proposes a method for calculating the degree of certainty. If an artificial neural network is trained sufficiently, similar inferred results would always be obtained. Consequently, by using the Monte Carlo dropout to delete weights at random, the certainty level is defined as the variance of the inferred results. To verify the usefulness of the CAPP system, a case study is conducted by assuming rough machining of dies and molds. The results confirm that the machining operations are inferred with high accuracy, and the proposed method is effective for evaluating the certainty of the inferred results.
{"title":"Computer Aided Process Planning for Rough Machining Based on Machine Learning with Certainty Evaluation of Inferred Results","authors":"Naofumi Komura, Kazuma Matsumoto, Shinji Igari, Takashi Ogawa, Sho Fujita, K. Nakamoto","doi":"10.20965/ijat.2023.p0120","DOIUrl":"https://doi.org/10.20965/ijat.2023.p0120","url":null,"abstract":"Process planning is well known as the key toward achieving highly efficient machining. However, it is difficult to standardize machining skills for process planning, which depend heavily on skilled operators. Hence, in a previous study, a computer aided process planning (CAPP) system using machine learning is developed to determine the operation parameters for finish machining of dies and molds. On the other hand, in rough machining, it is assumed that some machining operations are conducted sequentially using a respective tool according to the workpiece shape, which induces a much higher complexity in process planning. Therefore, in this study, machine learning is adopted to determine operation parameters for rough machining. The developed CAPP system converts the removal volume into a voxel model and infers a machining operation for each voxel. The inferred machining operation is visualized using different colors and identified corresponding to the voxel. Finally, the removal volume is classified using three different machining operations. However, machine learning is said to have a critical problem in that it is difficult to understand the reasons for the inferred results. Hence, it is necessary for the CAPP system to demonstrate the certainty level of the determined operation parameters. Thus, this study proposes a method for calculating the degree of certainty. If an artificial neural network is trained sufficiently, similar inferred results would always be obtained. Consequently, by using the Monte Carlo dropout to delete weights at random, the certainty level is defined as the variance of the inferred results. To verify the usefulness of the CAPP system, a case study is conducted by assuming rough machining of dies and molds. The results confirm that the machining operations are inferred with high accuracy, and the proposed method is effective for evaluating the certainty of the inferred results.","PeriodicalId":13583,"journal":{"name":"Int. J. Autom. Technol.","volume":"28 1","pages":"120-127"},"PeriodicalIF":0.0,"publicationDate":"2023-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80420283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-05DOI: 10.20965/ijat.2023.p0156
Shuohan Wang, Fuminobu Kimura, Shuaijie Zhao, E. Yamaguchi, Yuuka Ito, Yukinori Suzuki, Y. Kajihara
Efficient hybrid joining methods are required for joining metals and plastics in the automobile and airplane industries. Injection molded direct joining (IMDJ) is a direct joining technique that uses metal pretreatment and injection molding of plastic to form joints without using any additional parts. This joining technique has attracted attention from industries for its advantages of high efficiency and low cost in mass production. Blast-assisted IMDJ, an IMDJ technique that employs blasting as the metal pretreatment, has become suitable for the industry because metal pretreatment can be performed during the formation of the metal surface structure without chemicals. To satisfy industry standards, the blast-assisted IMDJ technique needs to be optimized under blasting conditions to improve joining performance. The number of parameters and their interactions make this problem difficult to solve using conventional control variable methods. We propose applying statistical and artificial intelligence analyses to address this problem. We used multiple linear regression and back propagation neural networks to analyze the experimental data. The results elucidated the relationship between the blasting conditions and joining strength. According to the machine learning predicted results, the best joining strength in blast-assisted IMDJ reached 22.3 MPa under optimized blasting conditions. This study provides new insights into similar engineering problems.
{"title":"Statistical and Artificial Intelligence Analyses of Blast Treatment Condition Effects on Blast-Assisted Injection Molded Direct Joining","authors":"Shuohan Wang, Fuminobu Kimura, Shuaijie Zhao, E. Yamaguchi, Yuuka Ito, Yukinori Suzuki, Y. Kajihara","doi":"10.20965/ijat.2023.p0156","DOIUrl":"https://doi.org/10.20965/ijat.2023.p0156","url":null,"abstract":"Efficient hybrid joining methods are required for joining metals and plastics in the automobile and airplane industries. Injection molded direct joining (IMDJ) is a direct joining technique that uses metal pretreatment and injection molding of plastic to form joints without using any additional parts. This joining technique has attracted attention from industries for its advantages of high efficiency and low cost in mass production. Blast-assisted IMDJ, an IMDJ technique that employs blasting as the metal pretreatment, has become suitable for the industry because metal pretreatment can be performed during the formation of the metal surface structure without chemicals. To satisfy industry standards, the blast-assisted IMDJ technique needs to be optimized under blasting conditions to improve joining performance. The number of parameters and their interactions make this problem difficult to solve using conventional control variable methods. We propose applying statistical and artificial intelligence analyses to address this problem. We used multiple linear regression and back propagation neural networks to analyze the experimental data. The results elucidated the relationship between the blasting conditions and joining strength. According to the machine learning predicted results, the best joining strength in blast-assisted IMDJ reached 22.3 MPa under optimized blasting conditions. This study provides new insights into similar engineering problems.","PeriodicalId":13583,"journal":{"name":"Int. J. Autom. Technol.","volume":"48 1","pages":"156-166"},"PeriodicalIF":0.0,"publicationDate":"2023-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88117545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-05DOI: 10.20965/ijat.2023.p0167
Isamu Nishida, Hayato Sawada, K. Shirase
This study proposes a method for automating the determination of assembly order by automating the derivation of the necessary connection relationships between the parts. The proposed method minimizes the information required for the initial conditions and automatically determines the feasible assembly orders. As a general rule, based on the assumption that the assembly order for a product is the reverse of the disassembly order, once the disassembly order is derived based on the 3D CAD model and the connection relationships between the parts, the assembly order can be determined. Until now, however, the relationships between the parts are decided manually by the attendant engineers, thus, hindering the full automation of the determination of the assembly order. To achieve full automation realistically, the connection relationships between the parts should be derived automatically from the 3D CAD model, for which this study proposes an efficient method. The components were extracted from the 3D CAD model, and the bolts were identified. The connection relationships between the parts were derived from the interference conditions determined while moving each part minutely. An association chart diagram was created from the obtained connection relationships, from which multiple assembly order candidates could be derived.
{"title":"Automated Generation of Product Assembly Order Based on Geometric Constraints Between Parts","authors":"Isamu Nishida, Hayato Sawada, K. Shirase","doi":"10.20965/ijat.2023.p0167","DOIUrl":"https://doi.org/10.20965/ijat.2023.p0167","url":null,"abstract":"This study proposes a method for automating the determination of assembly order by automating the derivation of the necessary connection relationships between the parts. The proposed method minimizes the information required for the initial conditions and automatically determines the feasible assembly orders. As a general rule, based on the assumption that the assembly order for a product is the reverse of the disassembly order, once the disassembly order is derived based on the 3D CAD model and the connection relationships between the parts, the assembly order can be determined. Until now, however, the relationships between the parts are decided manually by the attendant engineers, thus, hindering the full automation of the determination of the assembly order. To achieve full automation realistically, the connection relationships between the parts should be derived automatically from the 3D CAD model, for which this study proposes an efficient method. The components were extracted from the 3D CAD model, and the bolts were identified. The connection relationships between the parts were derived from the interference conditions determined while moving each part minutely. An association chart diagram was created from the obtained connection relationships, from which multiple assembly order candidates could be derived.","PeriodicalId":13583,"journal":{"name":"Int. J. Autom. Technol.","volume":"40 1","pages":"167-175"},"PeriodicalIF":0.0,"publicationDate":"2023-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72814347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.20965/ijat.2023.p0065
Liyun Xing
The substation inspection robot follows the set path when working autonomously, and accurate positioning of the robot while moving is required to ensure that the route does not deviate. This study briefly introduces a substation inspection robot, an odometer-based positioning algorithm, radio frequency identification (RFID), and a machine vision-based positioning algorithm, and improves the former algorithm by RFID. Subsequently, the three positioning algorithms were compared. The results showed that the RFID+machine vision-based positioning algorithm exhibited the highest accuracy among the three algorithms tested under the same cycle number, and its positioning error remained stable as the cycle number increased.
{"title":"Research on the Positioning and Recognition of an Intelligent Inspection Robot in Substations","authors":"Liyun Xing","doi":"10.20965/ijat.2023.p0065","DOIUrl":"https://doi.org/10.20965/ijat.2023.p0065","url":null,"abstract":"The substation inspection robot follows the set path when working autonomously, and accurate positioning of the robot while moving is required to ensure that the route does not deviate. This study briefly introduces a substation inspection robot, an odometer-based positioning algorithm, radio frequency identification (RFID), and a machine vision-based positioning algorithm, and improves the former algorithm by RFID. Subsequently, the three positioning algorithms were compared. The results showed that the RFID+machine vision-based positioning algorithm exhibited the highest accuracy among the three algorithms tested under the same cycle number, and its positioning error remained stable as the cycle number increased.","PeriodicalId":13583,"journal":{"name":"Int. J. Autom. Technol.","volume":"10 1","pages":"65-70"},"PeriodicalIF":0.0,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82243077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.20965/ijat.2023.p0040
Tappei Kawasato, Hinata Takamaru, Kazuhisa Hamazono, M. Fukuta, Katsuto Tanaka, Yusuke Chiba, Mikinori Nagano, Hidebumi Kato, Y. Kakinuma
The demand for optical glass lenses is rising owing to the increase in image resolution. Optical glass is a hard and brittle material. Thus, an efficient and precise grinding method is required for optical glass to improve lens quality and productivity. There are a few methods of producing crack-free machined surfaces; however, they provide only limited grinding efficiency. To resolve this issue, the authors’ group has proposed the reaction-induced slurry-assisted (RISA) grinding method, which expands the range of ductile-regime grinding by utilizing the chemical–mechanical action of a cerium oxide slurry. In this study, the grinding performance of RISA grinding is experimentally evaluated for different pH levels. The results are compared using Tukey’s test, where surface roughness is considered as the characteristic value and the pH value as the analyzed factor. The result shows that RISA grinding efficiently produces a high-quality surface when the slurry is alkaline. The adhesion of cerium oxide abrasives to the wheel in RISA grinding follows the same mechanism as slurry aggregation. In addition, adhesion is more likely to occur when the alkalization of the slurry promotes aggregation. The tank in the slurry supply unit is replaced with a rotating tank to ensure stable RISA grinding with a highly aggregable slurry while preventing aggregation. The performance evaluation shows that a high-quality surface with a surface roughness of less than 10 nm in most parts is obtained. Moreover, the critical depth of cut stably increases by a factor of 5.8.
{"title":"Slurry Conditions for Reaction-Induced Slurry-Assisted Grinding of Optical Glass Lens","authors":"Tappei Kawasato, Hinata Takamaru, Kazuhisa Hamazono, M. Fukuta, Katsuto Tanaka, Yusuke Chiba, Mikinori Nagano, Hidebumi Kato, Y. Kakinuma","doi":"10.20965/ijat.2023.p0040","DOIUrl":"https://doi.org/10.20965/ijat.2023.p0040","url":null,"abstract":"The demand for optical glass lenses is rising owing to the increase in image resolution. Optical glass is a hard and brittle material. Thus, an efficient and precise grinding method is required for optical glass to improve lens quality and productivity. There are a few methods of producing crack-free machined surfaces; however, they provide only limited grinding efficiency. To resolve this issue, the authors’ group has proposed the reaction-induced slurry-assisted (RISA) grinding method, which expands the range of ductile-regime grinding by utilizing the chemical–mechanical action of a cerium oxide slurry. In this study, the grinding performance of RISA grinding is experimentally evaluated for different pH levels. The results are compared using Tukey’s test, where surface roughness is considered as the characteristic value and the pH value as the analyzed factor. The result shows that RISA grinding efficiently produces a high-quality surface when the slurry is alkaline. The adhesion of cerium oxide abrasives to the wheel in RISA grinding follows the same mechanism as slurry aggregation. In addition, adhesion is more likely to occur when the alkalization of the slurry promotes aggregation. The tank in the slurry supply unit is replaced with a rotating tank to ensure stable RISA grinding with a highly aggregable slurry while preventing aggregation. The performance evaluation shows that a high-quality surface with a surface roughness of less than 10 nm in most parts is obtained. Moreover, the critical depth of cut stably increases by a factor of 5.8.","PeriodicalId":13583,"journal":{"name":"Int. J. Autom. Technol.","volume":"112 1","pages":"40-46"},"PeriodicalIF":0.0,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87705261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.20965/ijat.2023.p0014
M. Fujimoto, M. Fujita
The surface topography of ceramic grinding wheels used in creep feed grinding is examined in this study. Creep feed grinding experiments are performed using seeded gel (SG) grinding wheels. The three-dimensional surface of the grinding wheel is observed using a two-dimensional high-definition laser displacement sensor, and the effective cutting-edge number is calculated based on three-dimensional surface observations. Microscopic wear behaviors of grain cutting edges are examined based on scanning electron microscope (SEM) images. The cutting-edge area percentage is calculated based on SEM images via the discriminant analysis method. Results show that the micro self-sharpening phenomenon can be evaluated quantitatively. Micro sharp cutting edges on grains and normal grinding forces are suppressed. Subsequently, the relationship between the grinding characteristics and behaviors of the SG wheel working surface is investigated.
{"title":"Three-Dimensional Evaluation of Microscopic Wheel Surface Topography in Creep Feed Grinding Using Ceramics Grinding Wheel","authors":"M. Fujimoto, M. Fujita","doi":"10.20965/ijat.2023.p0014","DOIUrl":"https://doi.org/10.20965/ijat.2023.p0014","url":null,"abstract":"The surface topography of ceramic grinding wheels used in creep feed grinding is examined in this study. Creep feed grinding experiments are performed using seeded gel (SG) grinding wheels. The three-dimensional surface of the grinding wheel is observed using a two-dimensional high-definition laser displacement sensor, and the effective cutting-edge number is calculated based on three-dimensional surface observations. Microscopic wear behaviors of grain cutting edges are examined based on scanning electron microscope (SEM) images. The cutting-edge area percentage is calculated based on SEM images via the discriminant analysis method. Results show that the micro self-sharpening phenomenon can be evaluated quantitatively. Micro sharp cutting edges on grains and normal grinding forces are suppressed. Subsequently, the relationship between the grinding characteristics and behaviors of the SG wheel working surface is investigated.","PeriodicalId":13583,"journal":{"name":"Int. J. Autom. Technol.","volume":"8 1","pages":"14-20"},"PeriodicalIF":0.0,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78918563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.20965/ijat.2023.p0047
Y. Hashimoto, Yugo Nakayama, T. Furumoto, Akihito Sekiya, Tetsuya Yamada, Tatsuki Kawahara, A. Hosokawa
Gyro finishing is a mass-finishing process in which fixed workpieces are finished by contact with the flow of abrasive media owing to the rotation of the barrel. The process is used to finish large complex-shaped workpieces, such as large gears and parts constructed using additive manufacturing. In our previous study, we proposed a cover plate positioned above a workpiece to restrict the upward motion of abrasive media after contact with the workpiece, thereby improving the finishing speed. In this study, plates were added at the side of the workpiece to restrict the flow of the abrasive media toward the side of the workpiece and further improve the finishing speed. First, we evaluated the effect of the side plates using a simple-shaped workpiece. The difference in the surface roughness during a 5 min process was evaluated under certain conditions of the side cover plates. We confirmed that the finishing speed can be increased by using a side cover plate whose front was positioned behind the workpiece center because of the restriction of motion of the abrasive media. In contrast, the finishing speed decreased when a side cover plate whose front was positioned in front of the workpiece center was used because of the interruption in the transmission of force from the barrel wall to the abrasive media near the workpiece, owing to the side cover plates. Subsequently, the effect of the side cover plates placed at a suitable position was evaluated based on variations in the surface roughness during the process. We confirmed that the finishing speed increased by approximately a factor of 1.5 when the side cover plates were used owing to restrictions in the motion of the abrasive media. Finally, a spur gear was finished with cover plates, as a sample of practical workpieces. The finishing speed was determined based on the difference in the surface roughness of the gear teeth during the process. The finishing speed increased when a side cover plate whose front was positioned behind the workpiece center was used. Therefore, it can be concluded that the use of side cover plates is an effective technique to improve the finishing speed in gyro finishing.
{"title":"Finishing Speed Improvement Using Side Cover Plates in Gyro Finishing","authors":"Y. Hashimoto, Yugo Nakayama, T. Furumoto, Akihito Sekiya, Tetsuya Yamada, Tatsuki Kawahara, A. Hosokawa","doi":"10.20965/ijat.2023.p0047","DOIUrl":"https://doi.org/10.20965/ijat.2023.p0047","url":null,"abstract":"Gyro finishing is a mass-finishing process in which fixed workpieces are finished by contact with the flow of abrasive media owing to the rotation of the barrel. The process is used to finish large complex-shaped workpieces, such as large gears and parts constructed using additive manufacturing. In our previous study, we proposed a cover plate positioned above a workpiece to restrict the upward motion of abrasive media after contact with the workpiece, thereby improving the finishing speed. In this study, plates were added at the side of the workpiece to restrict the flow of the abrasive media toward the side of the workpiece and further improve the finishing speed. First, we evaluated the effect of the side plates using a simple-shaped workpiece. The difference in the surface roughness during a 5 min process was evaluated under certain conditions of the side cover plates. We confirmed that the finishing speed can be increased by using a side cover plate whose front was positioned behind the workpiece center because of the restriction of motion of the abrasive media. In contrast, the finishing speed decreased when a side cover plate whose front was positioned in front of the workpiece center was used because of the interruption in the transmission of force from the barrel wall to the abrasive media near the workpiece, owing to the side cover plates. Subsequently, the effect of the side cover plates placed at a suitable position was evaluated based on variations in the surface roughness during the process. We confirmed that the finishing speed increased by approximately a factor of 1.5 when the side cover plates were used owing to restrictions in the motion of the abrasive media. Finally, a spur gear was finished with cover plates, as a sample of practical workpieces. The finishing speed was determined based on the difference in the surface roughness of the gear teeth during the process. The finishing speed increased when a side cover plate whose front was positioned behind the workpiece center was used. Therefore, it can be concluded that the use of side cover plates is an effective technique to improve the finishing speed in gyro finishing.","PeriodicalId":13583,"journal":{"name":"Int. J. Autom. Technol.","volume":"9 1","pages":"47-54"},"PeriodicalIF":0.0,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75725930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.20965/ijat.2023.p0005
Chieko Kuji, Kuniyuki Izumita, K. Shimada, M. Mizutani, K. Sasaki, T. Kuriyagawa
Powder jet machining is a blast machining process in which micrometer-order particles are projected onto a workpiece at near-supersonic speeds, to remove the workpiece (abrasive jet machining (AJM)) or to deposit the particles (powder jet deposition (PJD)). We report a novel dental treatment method for powder jet machining using hydroxyapatite, which is the main component of teeth, as deposited particles. The surfaces and interdental spaces of human teeth are not only flat, but also have complex groove structures. However, PJD and AJM exhibit impact-angle-dependent machining phases. Therefore, it is necessary to investigate the effect of the particle impact angle on machining, before dental treatment. Furthermore, because machining interacts not only with the particle impact angle but also with the particle impact velocity, a comprehensive investigation of the effects of the machining parameters is required, for delineating the phase-transition conditions. Accordingly, in this study, we conducted machining experiments using hydroxyapatite particles (particle diameter, 2.16 μm) and four different blasting angles of 30°, 45°, 60°, and 90°, to infer the machining amount. Machining efficiency was evaluated based on the amount of machining. The impact angles and velocities of the particles were calculated using computational fluid dynamics (CFD). Three-dimensional process mapping was performed using the machining amount, particle impact angle, and particle impact velocity, obtained from the experiments and CFD calculations. The results showed that PJD crossed to AJM at the impact angle of approximately 60°. Moreover, PJD exhibited high processing efficiency for impact angles above 60° and impact velocities in the 280–310 m/s range. In contrast, AJM exhibited high processing efficiency for impact angles below approximately 35° and impact velocities above 310 m/s.
{"title":"Influence of the Impact Angle on Machining in Powder Jet Processing","authors":"Chieko Kuji, Kuniyuki Izumita, K. Shimada, M. Mizutani, K. Sasaki, T. Kuriyagawa","doi":"10.20965/ijat.2023.p0005","DOIUrl":"https://doi.org/10.20965/ijat.2023.p0005","url":null,"abstract":"Powder jet machining is a blast machining process in which micrometer-order particles are projected onto a workpiece at near-supersonic speeds, to remove the workpiece (abrasive jet machining (AJM)) or to deposit the particles (powder jet deposition (PJD)). We report a novel dental treatment method for powder jet machining using hydroxyapatite, which is the main component of teeth, as deposited particles. The surfaces and interdental spaces of human teeth are not only flat, but also have complex groove structures. However, PJD and AJM exhibit impact-angle-dependent machining phases. Therefore, it is necessary to investigate the effect of the particle impact angle on machining, before dental treatment. Furthermore, because machining interacts not only with the particle impact angle but also with the particle impact velocity, a comprehensive investigation of the effects of the machining parameters is required, for delineating the phase-transition conditions. Accordingly, in this study, we conducted machining experiments using hydroxyapatite particles (particle diameter, 2.16 μm) and four different blasting angles of 30°, 45°, 60°, and 90°, to infer the machining amount. Machining efficiency was evaluated based on the amount of machining. The impact angles and velocities of the particles were calculated using computational fluid dynamics (CFD). Three-dimensional process mapping was performed using the machining amount, particle impact angle, and particle impact velocity, obtained from the experiments and CFD calculations. The results showed that PJD crossed to AJM at the impact angle of approximately 60°. Moreover, PJD exhibited high processing efficiency for impact angles above 60° and impact velocities in the 280–310 m/s range. In contrast, AJM exhibited high processing efficiency for impact angles below approximately 35° and impact velocities above 310 m/s.","PeriodicalId":13583,"journal":{"name":"Int. J. Autom. Technol.","volume":"204 1","pages":"5-13"},"PeriodicalIF":0.0,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75082430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.20965/ijat.2023.p0032
Tappei Oyamada, A. Mizobuchi, T. Ishida
Our laboratory has been exploring the development of tools for drilling holes in glass plates, and the drilling techniques to be adopted for it. A devised tool shape that could prevent the occurrence of cracks at the exit holes achieved high quality through hole drilling of 100 holes or more using only the drilling cycle. However, crack-free drilling beyond this number of holes cannot be performed. This is due to the adhesion of the residual chip on the tool surface when the number of holes increases. Therefore, further improvement of chip discharge is needed to achieve crack-free drilling. In this report, we consider that chip discharge results from the flow of the machining fluid. To investigate the cause of chip discharge, we analyzed the flow of the machining fluid in the hole using computational fluid dynamics and the supposed chip discharge conditions. The results obtained in this study are summarized as follows. (1) In the case of a cylindrical tool, the Z-axis directional flow of the machining fluid did not occur in the hole. This is because the tool does not have bumps to agitate the fluid on the side, and the gap between the tool and the inner surface of the hole is narrow. (2) The plate side widened the gap between the tool and inner surface of the hole. Therefore, the fluid was likely to flow in the Z-axis direction in the hole. (3) For the tool with the plane side bit, the flow entered the hole from one plane side and exited the hole from the other plane side. (4) When the tool end is spherical, the Z-axis directional flow of the fluid occurs at the tool end. (5) The fluid flow of the devised tool weakened as the drilling depth increased. To improve the chip discharge performance of the designed tool, the Z-axis directional flow of the machining fluid must occur in an area deeper than 2 mm.
{"title":"Effects of Bit Shape of Electroplated Diamond Tool Used for Drilling Small Diameter Holes in Glass Plate on Machining Fluid Flow and Chip Discharge","authors":"Tappei Oyamada, A. Mizobuchi, T. Ishida","doi":"10.20965/ijat.2023.p0032","DOIUrl":"https://doi.org/10.20965/ijat.2023.p0032","url":null,"abstract":"Our laboratory has been exploring the development of tools for drilling holes in glass plates, and the drilling techniques to be adopted for it. A devised tool shape that could prevent the occurrence of cracks at the exit holes achieved high quality through hole drilling of 100 holes or more using only the drilling cycle. However, crack-free drilling beyond this number of holes cannot be performed. This is due to the adhesion of the residual chip on the tool surface when the number of holes increases. Therefore, further improvement of chip discharge is needed to achieve crack-free drilling. In this report, we consider that chip discharge results from the flow of the machining fluid. To investigate the cause of chip discharge, we analyzed the flow of the machining fluid in the hole using computational fluid dynamics and the supposed chip discharge conditions. The results obtained in this study are summarized as follows. (1) In the case of a cylindrical tool, the Z-axis directional flow of the machining fluid did not occur in the hole. This is because the tool does not have bumps to agitate the fluid on the side, and the gap between the tool and the inner surface of the hole is narrow. (2) The plate side widened the gap between the tool and inner surface of the hole. Therefore, the fluid was likely to flow in the Z-axis direction in the hole. (3) For the tool with the plane side bit, the flow entered the hole from one plane side and exited the hole from the other plane side. (4) When the tool end is spherical, the Z-axis directional flow of the fluid occurs at the tool end. (5) The fluid flow of the devised tool weakened as the drilling depth increased. To improve the chip discharge performance of the designed tool, the Z-axis directional flow of the machining fluid must occur in an area deeper than 2 mm.","PeriodicalId":13583,"journal":{"name":"Int. J. Autom. Technol.","volume":"1 1","pages":"32-39"},"PeriodicalIF":0.0,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89198386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.20965/ijat.2023.p0055
K. Yoshitomi, Yoshinori Shimada, A. Une
An increased removal rate is required to improve the production efficiency during the polishing of ultrahard-to-process materials. The rotational speed of the polishing pad is increased to increase the removal rate. However, research has not been extensively conducted on polishing with a high-speed rotation because slurry is rarely supplied to a polishing area by the centrifugal force generated through polishing pad rotation. In this study, we developed a high-speed rotational polishing system with slurry confinement and friction-state control. The casing and spiral groove of the polishing pad were designed to confine the slurry in a polishing area, and friction-state control was adopted to maintain the spindle torque generated by friction between the pad and wafer at the target spindle torque. Based on the experiments investigating the supply efficiency, the developed polishing method can supply sufficient slurry to the polishing area by the optimized spiral groove pattern and perform polishing without slurry shortage at a high-speed pad rotation of 10000 min-1. In addition, the results of polishing experiments for a sapphire wafer revealed that friction-state control and wafer rotation could stabilize the polishing state effectively. The proposed polishing system can achieve a higher removal rate than the conventional polishing system.
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