With the rapid development of China's science and technology and social economy, computer information technology is widely used in the field of mechanical engineering technology. Numerical control technology has b...With the rapid development of China's science and technology and social economy, computer information technology is widely used in the field of mechanical engineering technology. Numerical control technology has been popularized and applied in various industries, especially in mechanical manufacturing industry. There is still a large space for development in the application of numerical control technology in China. Therefore, numerical control technology should be studied and broken through in the next step, so as to provide support for China’s mechanical mold manufacturing industry. On this premise, this paper first expounds the principle of NC machining technology, and then explains its application advantages, scope of application and function one by one. Finally, it puts forward the methods of how to optimize and improve in machining process, so as to provide relevant reference for the development of NC machining industry.展开更多
With the deepening of global economic integration, the machinery manufacturing and mechanic technology of developed countries have a great impact on China's machinery manufacturing and processing technology. Numer...With the deepening of global economic integration, the machinery manufacturing and mechanic technology of developed countries have a great impact on China's machinery manufacturing and processing technology. Numerical control technology is widely used in related industries, and it is used more vigorously in automatic machinery manufacturing industry, which can not only promote the long-term development of automatic machinery manufacturing, but also lay a solid foundation for automatic machinery manufacturing. Therefore, numerical control technology plays a key role in automatic machinery manufacturing. Next, this paper discusses the practical application of numerical control technology in automatic machinery manufacturing.展开更多
The numerical control technology application major in secondary vocational schools trains the technical workers of numerical control processing. Physics plays an irreplaceable role in promoting the study of numerical ...The numerical control technology application major in secondary vocational schools trains the technical workers of numerical control processing. Physics plays an irreplaceable role in promoting the study of numerical control major and provides a foundation for the knowledge of mechanical processing. Under the situation of popular numerical control specialty, physics teaching in secondary vocational schools is declining. The teachers analyzed the current situation of physics teaching of numerical control technology application major in secondary vocational schools, and proposed countermeasures to adapt to social changes and improve the effectiveness of physics teaching.展开更多
For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock disp...For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sections, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, l-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic stability of surrounding rock and support structure.展开更多
Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control （CNC） system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical cont...Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control （CNC） system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical control （HITCNC）, is researched and manufactured based on the interface standards. The system＇s external interfaces are coincident with the corresponding international standards, and the internal interfaces follow the open modular architecture controller （OMAC） agreement. In the research and manufacturing process, object-oriented technology is used to ensure the openness of the HITCNC, and static programming is applied in the CNC system according to the idea of modularization disassembly. The HITCNC also actualizes real-time and unreal-time modules adopting real-time dynamical linked library （RTDLL） and component object model （COM）. Finite state ma- chine （FSM） is adopted to do dynamically modeling of HITCNC. The complete separation between the software and the hardware is achieved in the HITCNC by applying the SoftSERCANS technique. The application of the above key techniques decreases the programming workload greatly, and uses software programs replacing hardware functions, which offers plenty technique ensures for the openness of HITCNC. Finally, based on the HITCNC, a three-dimensional milling system is established. On the system, series experiments are done to validate the expandability and interchangeability of HITCNC. The results of the experiments show that the established open architecture CNC system HITCNC is correct and feasible, and has good openness.展开更多
vip Editor Prof.Jianfeng Li Univ.of Electronic Science and Technology of China lijianfeng@uestc.edu.cn The mid-infrared spectral domain is critically important and has considerable significance to fundamental scienc...vip Editor Prof.Jianfeng Li Univ.of Electronic Science and Technology of China lijianfeng@uestc.edu.cn The mid-infrared spectral domain is critically important and has considerable significance to fundamental science and technological applications.展开更多
A new method for generating tool paths for rough machining of sculpturedsurface is presented in this paper. The sculptured surface is approximated by a regular mesh ofquadrangular facets. A set of equidistant horizont...A new method for generating tool paths for rough machining of sculpturedsurface is presented in this paper. The sculptured surface is approximated by a regular mesh ofquadrangular facets. A set of equidistant horizontal planes are assigned to intersect the blank ofmachined part and surface model , resulting in a series of contours, which demarcate the feasiblecutting regions of each layer of material removal. The desired cutter path is computed through NCprogramming and any gouging between the cutter and the part being machined is detected and correctedautomatically. The proposed algorithm successfully solves the problem of layered milling forsculptured surface with nested islands.展开更多
The island coal face arises in coal mines with the purpose of preventing gas explosion or maintaining the balance between mining and tunneling. However, its particular stress conditions in the surrounding rock may inc...The island coal face arises in coal mines with the purpose of preventing gas explosion or maintaining the balance between mining and tunneling. However, its particular stress conditions in the surrounding rock may increase the difficulty of stress control in the coal face and in its mining roadways, especially when the coal seam, the roof, and the floor have rock-burst propensities, The high energy accumulated in the island coal face and in its roof and floor will intensify rock-burst propensity or even induce rock burst, which further result in great casualties and financial losses. Taking island coal face 2321 in Jinqiao coal mine as a case, we propose a method for the prediction of rock-burst-threatened areas in an island coal face with weak rock-burst propensity. Based on the anaHysis of the movement of the overlying roof and characteristics of stress distribution, this method combined numerical simulation with drilling bits to ensure the prediction accuracy. The effects of coal pillars with different widths on the mitigation of stress concentration in the coal face and on the prevention of rock burst are analyzed together with the mech- anism behind. Finally, corresponding measures against the rock burst in the island coal face are proposed.展开更多
In the practice teaching of vocational schools, the current teaching situation is not optimistic, and the traditional teaching mode is still followed. The practice teaching link is relatively weak, which is not conduc...In the practice teaching of vocational schools, the current teaching situation is not optimistic, and the traditional teaching mode is still followed. The practice teaching link is relatively weak, which is not conducive to students' future job demands. Based on practical teaching problems, this paper implements teaching integration and puts forward purposeful and targeted improvement strategies aiming at the existing problems, which lays a theoretical basis for improving the quality of practical teaching and provides reference for related research.展开更多
For special-shaped parts, the clamping and processing are very difficult. Based on this, a part with high precision and special shape is selected as a case. In-depth analysis of its structure and accuracy, scientific ...For special-shaped parts, the clamping and processing are very difficult. Based on this, a part with high precision and special shape is selected as a case. In-depth analysis of its structure and accuracy, scientific and reasonable formulation of the processing technology, at the same time, the complete involvement of special tooling and fixtures, so as to ensure the simplification of parts processing, and thus ensure the processing progress. At the same time, in order to effectively control the quality based on the accuracy and shape requirements of the parts themselves, if ordinary inspection equipment is applied, the purpose of inspection cannot be achieved. Therefore, according to the actual situation, special inspection tools should be designed to ensure the reliability and efficiency of the inspection. Based on this, this paper mainly analyzes and discusses the NC machining process analysis and testing of precision special-shaped parts.展开更多
The adaptive cycle engine(ACE)is considered a crucial candidate for the propulsion systems of next-generation aircraft.Its high thrust and low fuel consumption operating modes make it suitable for various flight missi...The adaptive cycle engine(ACE)is considered a crucial candidate for the propulsion systems of next-generation aircraft.Its high thrust and low fuel consumption operating modes make it suitable for various flight missions.However,the complex couplings and novel components in the ACE pose significant challenges to its performance design.This paper presents a systematic literature review on development status and performance deign of ACEs.Firstly,the development of ACE at various periods over the past few decades is presented.Then,four typical ACE configurations are introduced and analyzed based the differences of the core and the low-pressure compression system.After that,an emphasis is placed on the performance optimization method for ACE under various operating conditions,including steadystate,mode transition,acceleration/deceleration,and considering uncertainties.In addition,the numerical zooming technology for non-rotating components,rotating components,as well as intake and exhaust system are summarized in this paper.Through the above summary and analysis,the development trends in ACE performance design are explored.展开更多
文摘With the rapid development of China's science and technology and social economy, computer information technology is widely used in the field of mechanical engineering technology. Numerical control technology has been popularized and applied in various industries, especially in mechanical manufacturing industry. There is still a large space for development in the application of numerical control technology in China. Therefore, numerical control technology should be studied and broken through in the next step, so as to provide support for China’s mechanical mold manufacturing industry. On this premise, this paper first expounds the principle of NC machining technology, and then explains its application advantages, scope of application and function one by one. Finally, it puts forward the methods of how to optimize and improve in machining process, so as to provide relevant reference for the development of NC machining industry.
文摘With the deepening of global economic integration, the machinery manufacturing and mechanic technology of developed countries have a great impact on China's machinery manufacturing and processing technology. Numerical control technology is widely used in related industries, and it is used more vigorously in automatic machinery manufacturing industry, which can not only promote the long-term development of automatic machinery manufacturing, but also lay a solid foundation for automatic machinery manufacturing. Therefore, numerical control technology plays a key role in automatic machinery manufacturing. Next, this paper discusses the practical application of numerical control technology in automatic machinery manufacturing.
文摘The numerical control technology application major in secondary vocational schools trains the technical workers of numerical control processing. Physics plays an irreplaceable role in promoting the study of numerical control major and provides a foundation for the knowledge of mechanical processing. Under the situation of popular numerical control specialty, physics teaching in secondary vocational schools is declining. The teachers analyzed the current situation of physics teaching of numerical control technology application major in secondary vocational schools, and proposed countermeasures to adapt to social changes and improve the effectiveness of physics teaching.
基金Financial support for this work, provided by the Major Program of the National Natural Science Foundation of China (Nos. 51174196 and 51204168)the Program for New Century Excellent Talents in University by Ministry of Education of China (No. NCET-07-0519)
文摘For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sections, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, l-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic stability of surrounding rock and support structure.
基金This project is supported by Provincial Science & Technology Projoct of Heilongjiang, China (No. GB05A501).
文摘Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control （CNC） system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical control （HITCNC）, is researched and manufactured based on the interface standards. The system＇s external interfaces are coincident with the corresponding international standards, and the internal interfaces follow the open modular architecture controller （OMAC） agreement. In the research and manufacturing process, object-oriented technology is used to ensure the openness of the HITCNC, and static programming is applied in the CNC system according to the idea of modularization disassembly. The HITCNC also actualizes real-time and unreal-time modules adopting real-time dynamical linked library （RTDLL） and component object model （COM）. Finite state ma- chine （FSM） is adopted to do dynamically modeling of HITCNC. The complete separation between the software and the hardware is achieved in the HITCNC by applying the SoftSERCANS technique. The application of the above key techniques decreases the programming workload greatly, and uses software programs replacing hardware functions, which offers plenty technique ensures for the openness of HITCNC. Finally, based on the HITCNC, a three-dimensional milling system is established. On the system, series experiments are done to validate the expandability and interchangeability of HITCNC. The results of the experiments show that the established open architecture CNC system HITCNC is correct and feasible, and has good openness.
文摘vip Editor Prof.Jianfeng Li Univ.of Electronic Science and Technology of China lijianfeng@uestc.edu.cn The mid-infrared spectral domain is critically important and has considerable significance to fundamental science and technological applications.
文摘A new method for generating tool paths for rough machining of sculpturedsurface is presented in this paper. The sculptured surface is approximated by a regular mesh ofquadrangular facets. A set of equidistant horizontal planes are assigned to intersect the blank ofmachined part and surface model , resulting in a series of contours, which demarcate the feasiblecutting regions of each layer of material removal. The desired cutter path is computed through NCprogramming and any gouging between the cutter and the part being machined is detected and correctedautomatically. The proposed algorithm successfully solves the problem of layered milling forsculptured surface with nested islands.
基金provided by the National Natural Science Foundation of China (Nos.51304208 and 51474208)
文摘The island coal face arises in coal mines with the purpose of preventing gas explosion or maintaining the balance between mining and tunneling. However, its particular stress conditions in the surrounding rock may increase the difficulty of stress control in the coal face and in its mining roadways, especially when the coal seam, the roof, and the floor have rock-burst propensities, The high energy accumulated in the island coal face and in its roof and floor will intensify rock-burst propensity or even induce rock burst, which further result in great casualties and financial losses. Taking island coal face 2321 in Jinqiao coal mine as a case, we propose a method for the prediction of rock-burst-threatened areas in an island coal face with weak rock-burst propensity. Based on the anaHysis of the movement of the overlying roof and characteristics of stress distribution, this method combined numerical simulation with drilling bits to ensure the prediction accuracy. The effects of coal pillars with different widths on the mitigation of stress concentration in the coal face and on the prevention of rock burst are analyzed together with the mech- anism behind. Finally, corresponding measures against the rock burst in the island coal face are proposed.
文摘In the practice teaching of vocational schools, the current teaching situation is not optimistic, and the traditional teaching mode is still followed. The practice teaching link is relatively weak, which is not conducive to students' future job demands. Based on practical teaching problems, this paper implements teaching integration and puts forward purposeful and targeted improvement strategies aiming at the existing problems, which lays a theoretical basis for improving the quality of practical teaching and provides reference for related research.
文摘For special-shaped parts, the clamping and processing are very difficult. Based on this, a part with high precision and special shape is selected as a case. In-depth analysis of its structure and accuracy, scientific and reasonable formulation of the processing technology, at the same time, the complete involvement of special tooling and fixtures, so as to ensure the simplification of parts processing, and thus ensure the processing progress. At the same time, in order to effectively control the quality based on the accuracy and shape requirements of the parts themselves, if ordinary inspection equipment is applied, the purpose of inspection cannot be achieved. Therefore, according to the actual situation, special inspection tools should be designed to ensure the reliability and efficiency of the inspection. Based on this, this paper mainly analyzes and discusses the NC machining process analysis and testing of precision special-shaped parts.
基金funded by National Natural Science Foundation of China(NSFC)under Grants(No.51776010)the Fundamental Research Funds for the Central Universities and the Stable support project of the State Key Laboratory(No.12700002024146001).
文摘The adaptive cycle engine(ACE)is considered a crucial candidate for the propulsion systems of next-generation aircraft.Its high thrust and low fuel consumption operating modes make it suitable for various flight missions.However,the complex couplings and novel components in the ACE pose significant challenges to its performance design.This paper presents a systematic literature review on development status and performance deign of ACEs.Firstly,the development of ACE at various periods over the past few decades is presented.Then,four typical ACE configurations are introduced and analyzed based the differences of the core and the low-pressure compression system.After that,an emphasis is placed on the performance optimization method for ACE under various operating conditions,including steadystate,mode transition,acceleration/deceleration,and considering uncertainties.In addition,the numerical zooming technology for non-rotating components,rotating components,as well as intake and exhaust system are summarized in this paper.Through the above summary and analysis,the development trends in ACE performance design are explored.
