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  • Forun and information of industrial design
    DING Man, CHENG Yu, HUANG Xiao-guang, ZHAO Ling-ying
    Journal of Machine Design. 2020, 37(1): 121-127. https://doi.org/10.13841/j.cnki.jxsj.2020.01.022
    The continuous improvement of productivity transformed the key point of industrial design from function into meeting user emotional requirements. The concept of kansei engineering was concluded through relative literature domestic and overseas. The design process of image acquisition,model establishment and model optimization in the kansei engineering were concluded. Some representative technologies were list based on these processes. In the application, the research directions of kansei engineering, including product modeling,color and other properties were analyzed. According to the integrated development trend of kansei engineering and information technology,accurate acquisition of user multi-sensory image and improvement of model accuracy will become hotpots of future research.
  • Forun and information of industrial design
    LU Ji-xiang, YU Sui-huai, LU Zhang-de
    Journal of Machine Design. 2020, 37(4): 140-144. https://doi.org/10.13841/j.cnki.jxsj.2020.04.023
    The relevant literatures of intelligent design was sorted out in the field of industrial design to summarize theoretical research status, practical application and existing problems of intelligent design. The basic principles of intelligent design were discussed. The theoretical method system of intelligent design was established. The intelligence design trends were predicted. The research results showed that intelligent design system could help accelerate the integration of industrial design and artificial intelligence technology, forming intelligent design innovation model for industrial design.
  • Theses on special topics
    TIAN Yong-jun, SUN Shuang, ZHANG Xiang-yu, DUAN Guo-lin
    Journal of Machine Design. 2020, 37(3): 1-13. https://doi.org/10.13841/j.cnki.jxsj.2020.03.001
    This article reviews the progress in the research on the vibration and noise of circular saw blades;the inherent characteristics of diamond circular saw blades and the effect of sawing stability on the vibration characteristics of saw blades are explored;a series of discussion are conducted on the mechanisms of aerodynamic noise and sawing noise of circular saw blades.Besides,in terms of the vibration-and-noise reduction technology,the comprehensive analysis is conducted on the sawing parameter-optimization technology,the damping vibration-and-noise reduction technology,the adaptive control technology,the saw blade structure-and-size optimization technology,as well as the matrix-topology optimization technology and its mechanism. Finally,efforts are made to straighten out the problems related to vibration and noise of diamond circular saw blades and possible solutions.
  • Mordern equipment design technology and analysis of examples
    LIU Yu, XIE Ni, ZHANG Tuo
    Journal of Machine Design. 2020, 37(6): 115-122. https://doi.org/10.13841/j.cnki.jxsj.2020.06.018
    Crawler chassis has excellent performance such as low ground pressure,flexible steering and good maneuverability,which is regarded as an optimal scheme for small mountain-based agricultural machinery-driven chassis. In this article,the terrain-passing ability of the common walking device of the crawler chassis is evaluated,with the width of the ditch and the height of the vertical obstacle as the index. Thus,a crawler-chassis design scheme suitable for agricultural machinery in mountain areas is proposed. With the multi-body dynamic software RecurDyn,the simulation of the straight,climbing and obstacletraveling process of the crawler chassis under the hard and soft road conditions is carried out,and as a result,the scheme is feasible. The research will provide reference for the design of crawler chassis.
  • Forun and information of industrial design
    DAI Ming-yuan, LU Yi-lin, WANG Shuo, ZHANG Han
    Journal of Machine Design. 2020, 37(7): 116-123. https://doi.org/10.13841/j.cnki.jxsj.2020.07.019
    As an important infrastructure tool in the field of equipment manufacturing,the quality of ergonomic design is ofgreat importance to production efficiency and safety. In order to perform ergonomic verification in time during the design process ofengineering machinery products and avoid trial production risks,the ergonomic design method of engineering machinery productshad been studied using virtual reality technology. Through the collection and collation of relevant literatures and comparative analysis,recent research results of ergonomic design on engineering machinery products using virtual reality technology had been analyzed. The study content of virtual ergonomic design inside and outside cockpit of engineering machinery products was analyzed.The method of engineering machinery products ergonomic design based on virtual reality technology was summarized,which providedrelative references for the design in this field.
  • Mordern equipment design technology and analysis of examples
    SONG Zhong-yue, XU Qing-kun, WANG Ya-ling
    Journal of Machine Design. 2020, 37(11): 115-119.
    In this article, a 6-axis industrial robot driven by the stepping motor is designed based on the D-H model, and the model of the robot's core components is worked out. In order to meet the design requirements of the industrial robot, the method of circular feedback is used to optimize the design. Such tasks as motion simulation, finite-element analysis, interference collision detection and stress calculation are carried out on this robot, so as to verify whether the robot's structure is rationale. It provides basis for the development and improvement of industrial robots.
  • Forun and information of industrial design
    DAI Ming-yuan, WANG Ming-jiang, XIAO Li-wei, YANG Wen-jun
    Journal of Machine Design. 2020, 37(3): 128-134. https://doi.org/10.13841/j.cnki.jxsj.2020.03.021
    Engineering machinery products belongs to complex industrial products. The optimization of its R&D process is an important research content in the field of engineering machinery industry. In order to avoid the trial production risk of engineering machinery products,the way of embedding virtual reality technology into R&D process of engineering machinery products has been studied. The research results of virtual design of engineering machinery products in recent years has been analyzed through relevant literature arrangement and comparative analysis. The status of industrial design and engineering design using virtual design method in the R&D process of engineering machinery products were analyzed. The application mode of virtual design for engineering machinery products design is summarized,which provides relative references for design and research in this field.
  • Theses on special topics
    ZHANG Zhao-huang, LI Wei-wei, XIAO Peng-fei
    Journal of Machine Design. 2020, 37(11): 1-11.
    As an alternative to fossil energy, wind energy has attracted wide attention and widely application because of its less land occupation, low cost of power generation and low impact on environment. The wind turbine's blades, which convert wind energy into wind turbine kinetic energy, play a decisive role in the rotor's power coefficient. This article briefly introduces some achievements of the research on wind turbines, such as the special airfoil on blade, the method for calculating chord length and torsion angle as well as the synergistic device for blades. Some methods are explored; their theoretical basis and working principles are introduced.
  • Theses on special topics
    BAI Yi-dong, SUN Ling-yu, ZHANG Ming-lu, LIU Xiao-ya, LI Zhi-long
    Journal of Machine Design. 2020, 37(10): 1-13. https://doi.org/10.13841/j.cnki.jxsj.2020.10.001
    Tracked mobile robots are widely used in the military, agriculture and architecture fields thanks to their high maneuverability and outstanding off-road capability. It is of great significance to explore the traction performance, driving resistance and obstacle-obstacle ability of tracked mobile robots based on terramechanics. In the development of vehicle terramechanics, many methods are developed to the probe into the mechanism of interaction between the rubber track and the ground. These methods are classified into four categories, namely empirical, semi-empirical, physics-based, and numerical analysis methods. Firstly, they are classified and compared. Then, both the ground response model and the grouser effect model are summarized. The ground response model is applied to evaluate the passing ability of robots, and the grouser effect model exerts certain influence on traction performance. The response model is divided into the pressure-sinkage model and the shear stress-displacement model. Finally, the existing problems of terramechanics for tracked mobile robot are discussed, and feasible directions in the future are given, in order to provide some reference for follow-up research.
  • Forun and information of industrial design
    LUO Shi-jian
    Journal of Machine Design. 2020, 37(3): 121-127. https://doi.org/10.13841/j.cnki.jxsj.2020.03.020
    In the era of new economy with Internet and artificial intelligence,design environment,object and mode have been deeply changed. A new thought of crowd intelligence design was proposed based on innovation development situation such as social design,design crowd sourcing and crowd intelligence. The status of social design,design crowd sourcing and crowd intelligence were discussed. The connotation of crowd intelligence design including concept,research content and its relationships,features,values,key technologies,as well as future research requirement were analyzed. The ontology feature,user experience and co-creative value of crowd intelligence design were studied through ontology level,behavioral level and value level.With deep fusion and development of future social technology,design and business,crowd intelligence design will gather more and better idea flows,open crowd intelligence innovation mode and create co-value using Internet platform and artificial intelligence technology.
  • Theses on special topics
    SONG Zhi-qiang, CAO Li-bo, WU Jun, QIU Yang-di
    Journal of Machine Design. 2020, 37(2): 32-38. https://doi.org/10.13841/j.cnki.jxsj.2020.02.004
    With the rapid development of the active safety technology,the automatic emergency braking(AEB) system plays an important role in reducing the number of rear-collision accidents. However,the AEB system is different for each vehicle. In this article,in order to detect and evaluate the performance of the AEB system,both the rest equipment and the control system are worked out according to the test requirements and methods specified in China New Car Assessment Program(C-NCAP).With the help of the wireless communication technology,the subsystems cooperatively work after their control parameters are debugged; based on a series of test,the error meets the requirements issued by C-NCAP. Finally,some field tests are conducted to detect the performance of the AEB systems of five vehicles in the scenario of car-to-car rear static(CCRs). The results show that the test equipment can work smoothly in order to get desirable outcomes and effectively detect the AEB performance of target vehicle.
  • Innovation design
    XIAO Ren-bin, LIN Wen-guang
    Journal of Machine Design. 2020, 37(6): 1-10. https://doi.org/10.13841/j.cnki.jxsj.2020.06.001
    Customized design is a key mean to achieve product innovation,and its may is product family design. In order to improve the R&D capabilities of enterprises in mass customization environment,and remedy the shortcomings of existing product family design theory,a data-driven product family design process framework is proposed. Firstly,for satisfying the demands of product family design,the correlation between data requirements and data sources are analyzed; secondly,according to the characteristics of different stages of product design process,the data-driven mode is explored from four aspects,market segmentation,platform construction,product family evolution and portfolio innovation; finally,the key technologies of data mining,data prediction and data analysis needed in different steps during design process are proposed in detail,and the system architecture supporting data-driven product family design platform is completed.
  • Theses on special topics
    YANG Shuai, CHANG Bo-yan, LI Xiao-ning, ZHANG Zhuan
    Journal of Machine Design. 2020, 37(3): 39-46. https://doi.org/10.13841/j.cnki.jxsj.2020.03.007
    Based on the combination of the kite straight-line mechanism and the scissors mechanism,a new kite straight-line deployable unit with revolute joints merely is worked out. Then,the kite straight-line deployable mechanism is developed. According to the theories related to mechanism and structure,the modular principle of the kite straight-line deployable mechanism is illustrated,and the mechanism is divided into external module and internal module,which are both derived from the kite straight-line deployable unit. The kinematic model of a single kite straight-line deployable unit is set up firstly,and the kinematic relationship between the two adjacent modules is identified according to the modular principle. Based on the kinematic analysis,the Lagrange method is adopted to work out the dynamic model of the whole mechanism. With the mechanism featuring sixlayer modules as an example,the tasks of dynamic numerical calculation and virtual simulation are carried out. Based on the motion law of the end-effector,the driving torque is calculated,in order to verify whether the kinematic and dynamic models are correct and effective. The results show that there is no impact throughout the motion when the output-based motion law of the end-effector is mainly embodied as the sine acceleration curve.
  • Theses on special topics
    LI Wei-jian, CHEN Ji-qing, LAN Feng-chong, LI Shi-cheng
    Journal of Machine Design. 2020, 37(5): 8-14. https://doi.org/10.13841/j.cnki.jxsj.2020.05.002
    In order to meet the performance requirements of light steering and high-speed stable running for mini pure electric vehicles,the steering system is subject to the electric power-assisted optimization. With the influence of the steering geometry and the motor's power-assisted parameters taken into consideration,the parameterization of the electric power-assisted system is realized and the mathematical model of electromechanical coupling is worked out. The power-assisted characteristic curve is identified with the influence of vehicle speed taken into account,and efforts are made to ensure that the function is accurate,so that the system is accurate in fitting and the motor torque's control characteristics are identified. The electric power-assisted system is based on the fuzzy adaptive PID control strategy,in order to control the motor's current error,reduce the current deviation and enhance the accuracy in power assist. With the electromechanical-coupling mathematical model,the motor torque's control characteristics and the PID control strategy,the mechanical and power-assisted motor-control models are constructed by means of MATLAB/Simulink and ADAMS/CAR,and the joint simulation is carried out. The simulation results of the electric power-assisted system are compared with those of the non-assisted system in terms of continuous steering,high-speed steering and largeangle acceleration steering. The results under these conditions show that the electric power-assisted system reduces the steering torque of drivers by about 48% in the process of middle-and-low-speed serpentine running and effectively realizes the light steering. In addition,the high-speed steering time for the automobile under the conditions of high-speed stable running is shortened by about 20%.
  • Theses on special topics
    ZHANG Peng, LUO Yang, YANG Tong-da, YU Fei, LIU Wei-sheng
    Journal of Machine Design. 2020, 37(8): 1-10. https://doi.org/10.13841/j.cnki.jxsj.2020.08.001
    Design-Centric Complexity (DCC) focuses on the complexity of system from the perspective of function, and takes the probability of product realization as the representation of systematic complexity. With the rapid development of science and technology, the characteristics of complex systems such as non-linearity, strong coupling, time-varying and openness are increasingly prominent, and the research on complex systems becomes a hot topic both at home and abroad. In this article, from the perspective of design-centric complexity, with the four characteristics of complex systems as the starting point, the related research is conducted on complex systems, and the relationship between the complex system featuring the design-centric complexity and the complex system featuring the artificial self-recovery. Finally, both the fields of study and application and the future prospects of these complex systems characterized by the design-centric complexity and the artificial self-recovery are discussed.
  • Theses on special topics
    WANG Rui, ZHANG Yu-long, JING Xiao-hui, CHEN Zheng-man, ZHAI Ying-ming
    Journal of Machine Design. 2020, 37(11): 42-46.
    In this article, by the research on the operation status of the prototype of the heavy pressure centrifuge, the cause of the damage to the mechanism's inner mechanical seal of is identified. By optimizing the structure of the inner sealing system, dry friction turns into liquid lubrication, which improves the working environment of the sealing structure, realizes its continuous flushing and lubrication, and prolongs the service life of the mechanical seal.
  • Theses on special topics
    GU Yu-zhi, QU Chang, XU Wei-wei, WANG Jun-ze, WANG Jin, LI Yue-hua
    Journal of Machine Design. 2020, 37(9): 49-55. https://doi.org/10.13841/j.cnki.jxsj.2020.09.008
    For photovoltaic power stations, dust accumulation on the surface of photovoltaic modules seriously affects the power generation, and dust is difficult to clean. In order to realize the automatic cleaning of dust accumulation on the surface of photovoltaic modules, an auto solar-cleaning robot system is developed, which includes the cleaning car, the ferry car and the opticalstorage wireless charging system. The cleaning car with the in-line wall-mounted structure adopts the water-free cleaning method of spiral roller brush to clean while walking. The ferry car carries the cleaning car through the newline track and aligns the cleaning car with each row of photovoltaic modules accurately with the aid of the automatic adjustment mechanism. The optical-storage wireless charging system collects and stores the photovoltaic module's electric energy, and then charges the batteries of the ferry car and the cleaning car through the wireless charging equipment. The robot-control system takes the STM32F103RCT6 chip as the main control chip, and the cleaning car and ferry car communicate with each other via the 2. 4 GB wireless signal. The prototype test shows that the cleaning robot system has stable operation and desirable cleaning effect, and it realizes the automatic linewrapped cleaning for multi-row photovoltaic modules.
  • Theses on special topics
    ZHAO Tong, DU Yong-tao, WANG Zhan-zhong, SUN Qiang, LIN Wen-min, LI Ran
    Journal of Machine Design. 2020, 37(11): 66-71.
    In this article, in order to solve the maintenance problem of metal pillars in the canopy of high-speed railway stations, a magnetic-adsorption pole-climbing robot working on the metal pillars is developed. This robot can move forward, turn 90°, change its diameter and go back on the metal strut. It is simulated with the multi-body dynamics software Adams, so as to verify its feasibility, and the magnetic-adsorption force is calculated by means of the ANSYS software. With the actual situation of the metal strut surface taken into account, the simulation experiments of each action are completed. Furthermore, since the magnetic-adsorption force changes with the different working gap, the SPLINE function is adopted to set the magnetic-adsorption force; the reasonable walking speed, the changing range of the magnetic-adsorption force and the range of the working gap are finally identified. The simulation results provide reference for the design and manufacturing of magnetic-adsorption pole-climbing robots.
  • Mordern equipment design technology and analysis of examples
    LU Guang-da, QIE Tong-tong, HA Jian-bo, LIU Xing-bo, WU Xiang-bin
    Journal of Machine Design. 2020, 37(8): 66-70. https://doi.org/10.13841/j.cnki.jxsj.2020.08.010
    In view of the problems suffered by the existing lining trolleys, a new self-propelled lining trolley for the tunnel's omni-directional formwork is worked out, according to the characteristics of most excavated tunnels. The lining trolley is applied to the tunnels with horizontal and longitudinal ramps. Firstly, the structure of the new lining trolley is introduced; with the aid of the MIDAS auxiliary design software, the stress analysis is conducted on the key components such as formwork, arch plate and cross beam. The results show that the structural design is reasonable. With the most unfavorable load, the deformation of the trolley's frame and formwork meets the construction requirements.
  • Forun and information of industrial design
    WANG Nian-wen, LIU Yun-hua
    Journal of Machine Design. 2020, 37(10): 139-144. https://doi.org/10.13841/j.cnki.jxsj.2020.10.020
    In order to improve the rationality and accuracy of hand rehabilitation trainer design,a product design method based on FBS(Function-Behavior -Structure) and extension was proposed. The hierarchical relationship between user requirements and product structure was obtained. The product requirements were prioritized by entropy weight method. FBS model was used as the design framework to carry out function-behavior-structure mapping. The event element divergence of total function was carried out and the corresponding practical operation behavior was mapped combined with divergence tree method. The system components were layered and the matter elements were established according to different user requirements. The behavior was added and replaced using addition transformation and replacement transformation of extension transformation to obtain expected behavior and map out corresponding structure to perform extension transformation, so as to realize hand rehabilitation trainer redesign process. The results showed that,the combination method of entropy weight method based FBS model and extension transformation not only improved the functional structure of hand rehabilitation trainers, but also provided references for product innovation design.
  • Forun and information of industrial design
    LU Ning, ZHU Du-xin, LI Fang-yu
    Journal of Machine Design. 2020, 37(10): 128-133. https://doi.org/10.13841/j.cnki.jxsj.2020.10.018
    In order to improve the comfort of health testing machine, the function and module classification of the intelligent health testing machine were determined through the analysis of physiological and psychological changes of the elderly. 3D software was used to build digital model of health testing machine. The digital model was imported into Jack virtual simulation software to analyze human-machine interaction behavior under different functions from four aspects:ergonomic dimensions,comfort,accessibility and visual field. The key parts of human-machine adaptability of the device were obtained. The improved design was performed combinesd with stress analysis results of key parts and the comfort simulation verification was performed on the improved testing machine. The results showed that the forces exerted on muscles,joints and back of elderly users were significantly reduced,and the operation comfort was enhanced, which could provide references for the barrier free design of the elderly.
  • Theses on special topics
    DAN Yan-xia, FU Bing-shuang, LI Ruo-song, HAN Xue-yan, LI Shi-hua
    Journal of Machine Design. 2020, 37(6): 17-23. https://doi.org/10.13841/j.cnki.jxsj.2020.06.003
    The parallel mechanism has the advantages of simple structure and strong bearing capacity. Therefore, a dualactuated in-pipe robot for medium pipelines is worked out based on a novel 3-UPU parallel mechanism. The parallel mechanism serves as the support-actuating mechanism, in order to ensure the mode of supporting motion, including turning and walking in the non-cylindrical pipelines. Meanwhile, the parallel mechanism could rotate continuously, which ensures the stationarity of turning. The 4-leaf spiral as the spiral-actuating mechanism realizes the mode of spiral motion and accelerates the robot's movement. Besides, a connected angle-shift unit is developed to ensure the transformation of the two modes of motion and change the speed by adjusting the spiral angle. The in-pipe robot with compact structure, high speed and smooth operation could detect and maintain in the pipelines beyond the reach of human.
  • Theses on special topics
    LAI Jun-hao, ZHU Da-chang, ZHAN Wang-hu, YANG Jia-mou, ZHONG Yun
    Journal of Machine Design. 2020, 37(8): 41-49. https://doi.org/10.13841/j.cnki.jxsj.2020.08.006
    Since the compliant mechanism for spatial topological configuration is difficult to process and the processing cost is high, the method of assemblyable spatial topological configuration is proposed. Based on the kinematic analysis on the 3-PUU parallel mechanism, the Differential Jacobi Matrix is worked out; the Isomorphic Mapping Matrix of the 3-DOF translational compliant mechanism for spatial topological configuration is set up. Both the Isomorphic Mapping Matrix and SIMP (Solid Isotropic Material with Penalization) interpolation model are adopted for topological optimization, so that the 3-DOF translational compliant mechanism for spatial topological configuration is worked out and solved. Through the comparative analysis on the secondary modeling of topological configuration and the simulation of statics, the parameters of topological optimization are modified in a realtime manner, and the physical model is printed out in 3D for the related experimental analysis. The results show that the 3-DOF spatial translational compliant mechanism is identical to the 3-PUU parallel mechanism, which provides practical significance for the precise modeling and application of this compliant mechanism.
  • Theses on special topics
    WEI Lang, ZHOU Wen-cai, TIAN Shun, LIU Yong-tao, GONG Jian-qiang
    Journal of Machine Design. 2020, 37(1): 1-9. https://doi.org/10.13841/j.cnki.jxsj.2020.01.001
    The traditional vehicle reliability test which requires a large amount of statistic information on the vehicles has a certain hysteresis in the verification of vehicle reliability,which is not conducive to the vehicle reliability test as well as the development and optimization of vehicles. Thus,the enhancement test technology is widely used in the automobile design and finalization. In order to optimize the vehicle reliability test,this article summarizes the application of the enhancement test technology in the vehicle reliability test from three aspects:vehicle road test,bench reliability test,and virtual proving test,according to the characteristics of both the enhancement test technology and the vehicle fault model. Suggestions are made on the future trend of the enhancement test technology in the vehicle reliability test,based on summarizing the status quo and deficiencies of the vehicle reliability test,which provides reference for improving the automobile reliability,optimizing the automobile design and accelerating the vehicle reliability test.
  • Mordern equipment design technology and analysis of examples
    FANG Zi-fan, LIU Jin, YU Hong-chang, HE Kong-de, YANG Yu-hua, XIE Zhe-yu
    Journal of Machine Design. 2020, 37(2): 101-108. https://doi.org/10.13841/j.cnki.jxsj.2020.02.014
    In this article,aiming at the unstable steering and poor boost performance due to the long body and tonnage characteristics of four-axle heavy-duty vehicles,a design for the double front axle power-steering system is proposed. A six-link one-bridge steering mechanism and an eight-link two-bridge steering mechanism on the side of the tire are worked out symmetrically,and a new double front axle hydraulic power-steering system composed of a dual-circuit assist system and a double front axle steering mechanism is developed. Based on the Ackerman theorem,the relationship between the declination angles of the two front axles is derived;the rotation angles of the double front axles are identified with the minimum turning radius,in order to reduce the tire wear. A two-degree-of-freedom four-wheel monorail model is set up to explore its basic operating characteristics.Based on the empirical formula of the tire's in-situ steering torque,by means of the ADAMS and AMESim co-simulation technology,the mechanical-hydraulic coupling model from the steering wheel to the tire model is worked out,and thus the co-simulation interface file is generated to ensure the multi-domain modeling and co-simulation. Such dynamic characteristics of the hydraulic power-steering system as the hydraulic pressure,the steering response time and the tire's deflection angle are analyzed with the fixed input of the steering wheel's torque step,and it has proved that the design is rationale.
  • XIE Zhi-jiang, DONG A-bin, XING Shu-xia, YAO Meng, SUN Qi
    Journal of Machine Design. 2018, 35(8): 42-47.
    The 3 degree-of-freedom proper-constraint branch chain parallel mechanism is mainly composed of a moving platform, a static platform, three non-constraint UPS active branch chains, and a mid proper-constraint PU branch chain. With the aid of the screw theory, the driven sub jacobin matrix and the constrained sub jacobin matrix is obtained; based on this, the complete jacobin matrix is obtained. By means of the principle of virtual power, the model of the stiffness analysis of the 3 degree-of-freedom proper-constraint branch chain parallel mechanism is established. The stiffness matrix method is adopted, and by means of MATLAB Movement Simulation, the law of the distribution of static stiffness within the working space is obtained. The results show that the mid proper-constraint branch chain PU exerts obvious influence upon the overall stiffness.
  • Theses on special topics
    CHENG Chuan-tai, WANG Jun-nian, CHU Hong-sen, JIANG Zhu-heng, DUAN Chao-sheng
    Journal of Machine Design. 2020, 37(7): 1-7. https://doi.org/10.13841/j.cnki.jxsj.2020.07.001
    Safety is an important part of vehicle design. Currently, passive safety mostly depends on the optimization ofvehicle body or door structure, while the safety devices for vehicle seats are rarely to be seen. In this article, a new type of selftilting vehicle seats is developed, in order to protect the passengers from lateral impact. Firstly, the design boasts of both anelectric lifting-tilting device and an anti-collision-rod protective device for specific seats. Meanwhile, the key parameters, alongwith their corresponding motors, are identified. Secondly, the assembly and debugging of the physical prototype are completed.Finally, the start-up time of the two devices is tested. The results show that both the seat tilting and the anti-collision -rodextension within the specified time are ensured, thus effectively protecting the passengers in a short time.
  • Theses on special topics
    DU Xue-jing, CHEN Zhan-li
    Journal of Machine Design. 2020, 37(11): 33-41.
    In order to explore the low-speed frontal-collision crashworthiness of pure electric SUV and improve its insurance level, in this article, according to the European RCAR low-speed crash test procedure, the ANSA software is used to set up the low-speed fr ontal-collision finite-element model for pure electric SUV; by means of the LS-DYNA and HyperView software, the analysis is conducted on the deformation and energy absorption of the key components of the front end of electric SUV. For the problem of insufficient crashworthiness, the structure and parameters are optimized from the aspects of rigidity and strength. The results show that the crashworthiness of the key components of the front end improves as a whole, the energy absorption and deformation obviously improve, and the compression distance of the energy-absorption box is 111.8 mm, which is close to the minimum distance of 110 mm between the anti-collision beam on one hand and the fan and its mounting plate on the other hand. As a result, the extrusion exerted on the fan significantly reduces. The plastic deformation of the front longitudinal beam reduces from 45.41% to 12.52%. Since after optimization, both the compression distance of the energy-absorption box and the plastic deformation of the front longitudinal beam fail to satisfy the the RCAR test requirements, the multi-objective optimization is applied to further optimize the overall thickness of the key components. The results show that the RCAR test requirements are met finally, the compression distance of the energy absorbing box is 105.44 mm, the plastic defo rmation of the front longitudinal beam is 5.04%, and the front end has a higher standard of crashworthiness and lightweight effect.
  • Mordern equipment design technology and analysis of examples
    DING Yan, YU Guan-hua
    Journal of Machine Design. 2020, 37(4): 100-104. https://doi.org/10.13841/j.cnki.jxsj.2020.04.017
    In this article,a motion-adsorption scheme for the wall-climbing robot is worked out. Based on the three-trajectory cam-typed structure,a simple mechanical method is adopted to realize the automatic adsorption and separation of the adsorption components relative to the wall surface when the robot is moving. Thus,when the sucker is close to the ground,the lifted adsorption surface is parallel to the wall surface,and the sucker does not curl,thereby ensuring a high standard of air tightness and adsorption stability. Furthermore,the analysis is conducted on the adsorption safety of the adsorption components; as a result,the scheme will be realized smoothly.
  • Forun and information of industrial design
    HU Shan, LIU Jing
    Journal of Machine Design. 2020, 37(1): 135-139. https://doi.org/10.13841/j.cnki.jxsj.2020.01.024
    In order to reasonably evaluate and determine design scheme using fuzzy comprehensive evaluation method,the evaluation process was revised to obtain more objective results. The design of the guide rod was taken as an example to construct evaluation system of guide rod design scheme through literature review and group discussion. The fuzzy comprehensive evaluation method was used to perform evaluation and selection of the scheme. The entropy weight method was introduced to modify the subjectivity of analytic hierarchy process in determining weight of evaluation index while determining the weight of each evaluation index. The optimal solution was thereby selected. Fuzzy comprehensive evaluation method was applied to the specific design evaluation to obtain evaluation result of the design scheme. Fuzzy comprehensive evaluation method in the preliminary design of the product scheme could effectively help decision makers evaluate global design scheme, so as to grasp product development direction better. The introduction of entropy weight method could effectively improve subjective problem in determining weight of evaluation indicators. The objective evaluation results were obtained. This method was also applicable to the evaluation and determination of other design schemes.
  • Forun and information of industrial design
    YOU Wen-hua, WANG Li-chao, WANG Xu, NIU Yu-zhi, CHEN Mei-ling, XUE Wen-jun, WEI Jiao
    Journal of Machine Design. 2020, 37(1): 140-144. https://doi.org/10.13841/j.cnki.jxsj.2020.01.025
    In order to design a fitness equipment to meet the home sports requirement,the structure of a home multi-functional treadmill was designed using ergonomic theory of the fitness equipment and the knowledge of industrial design based on the basic form of treadmill with characteristics of home products. SolidWorks software was used to build a three-dimensional model of a home multi-functional treadmill. The rationality of the structure was ensured through simulation. PLC unit was embedded to control working mode to achieve free conversion between modes. Finite element simulation software was used to perform static analysis on the parts of the home multi-functional treadmill. The results showed that the structure strength of the home multi-functional treadmill was qualified. Function integration of fitness equipment and home products could provide references for the development of home sports fitness equipment.
  • Forun and information of industrial design
    LI Rui-zhen, WU Yong-meng, ZHI Jin-yi
    Journal of Machine Design. 2020, 37(9): 134-139. https://doi.org/10.13841/j.cnki.jxsj.2020.09.020
    In order to explore industrial design factors that influencing comfort of wireless headphones,web comments were obtained using crawler technology based on web comments method. A set of comfort evaluation words was established for wireless earphone using semantic analysis. The comfort evaluation of web comments were encoded, extracting material factor,wear factor and quality factor as industrial design elements of wireless earphone. The frequency of comfort evaluation was grouped and counted.The research showed that three industrial design elements had significant influence on wear comfort and wear stability. The lightweight,half-in wireless earphones made of silica gel were more comfortable but less stable to wear. The choice of wireless earphone industrial design element should be considered comprehensively for the optimal wearing comfort and wearing stability. The user requirement study method could provide references for comfort study of other products based on web comment data.
  • Theses on special topics
    ZHAO Rui-kai, ZHANG Jian-hui, WANG Xue-rui, ZHANG Wan-ming
    Journal of Machine Design. 2020, 37(6): 29-37. https://doi.org/10.13841/j.cnki.jxsj.2020.06.005
    Due to the limit of the current conflict analysis,it is difficult to analyze and identify multiple conflicts of those systems with complex technologies. To solve this problem,a multi-domain hierarchical mapping model is set up based on the Petri net. The mathematical tools related to the Petri net are adopted for functional failure analysis; the demand analysis are conducted,in order to identify the conflicts comprehensively and accurately and build up a multi-conflict network; then,the TRIZ tools are employed to solve problems. Finally,the non-avoidance three-dimensional garage serves as an engineering example for the innovative design scheme,which has verified that this method is effective.
  • Mordern equipment design technology and analysis of examples
    LIU Dong-yi, YANG Jian-wei, LI Xin, WANG Jin-hai, ZHU He-kai
    Journal of Machine Design. 2020, 37(3): 59-66. https://doi.org/10.13841/j.cnki.jxsj.2020.03.010
    Helical gear is a main form of transmission applied in metro vehicles. Serious root crack may lead to gear fracture,which greatly affects the safe operation of vehicles. Therefore,the research on the crack propagation of gear root is of great significance for the service performance of helical gears. This article focuses on the application of helical gears in metro gear boxes. Firstly,the transient response dynamics of gears is analyzed with the aid of the method of Newmark time integration,and the analysis is conducted on the maximum bending stress at the dangerous section of helical gear root,which is obtained from the national standard GB/T 3480.5—2008. As a result,the model is validated. Then,the crack propagation of gears is explored by XFEM(Extended Finite Element Method),and the analysis is carried out on crack propagation path and life prediction. The simulation results show that the failure mode of the bending fatigue of helical gears in metro gear boxes is characterized by the Ⅲ crack,which is dominated by the mode of I crack. The crack at the root of gears originates from a certain end face and propagates along the direction of gear thickness and width. When the crack along the direction of gear width extends to a certain level,the crack propagation path changes its direction. The life-prediction analysis is conducted on the gear with an initial crack of 4 mm in length and 2 mm in width on the end face of gear,and it's found that the cycle life of the gear with the initial crack is 16×105 times.
  • Journal of Machine Design. 2020, 37(6): 151-151. https://doi.org/10.13841/j.cnki.jxsj.2020.06.029
  • Forun and information of industrial design
    SU Jian-ning, WEI Jin
    Journal of Machine Design. 2020, 37(8): 121-126. https://doi.org/10.13841/j.cnki.jxsj.2020.08.020
    In order to improve operation method of rose buds and picking efficiency, interview method and analytic hierarchy process were used to obtain the weight of customer requirements. QFD method was used to analyze key design elements, including structure, function and modeling of harvesting machine. The design idea was proposed based on TRIZ theory. The design of picking machine was completed according to the overall functional requirements. The field test of the prototype revealed that the picking efficiency was improved apparently, and the feasibility of the design scheme was verified. This could provide references for the design of picking and collection equipment.
  • Theses on special topics
    CHEN Hong-yue, HU Xue-bing, ZHU Hui-dong, LI En-dong, BAI Yang-xi
    Journal of Machine Design. 2020, 37(4): 55-60. https://doi.org/10.13841/j.cnki.jxsj.2020.04.009
    In this article,in order to explore the stress distribution on several cross sections of the conveyor belt,for example,the transition part,the relationship between the stress and strain of the conveyor belt is analyzed with the aid of the electronic universal tensile experiment,and the universal friction-wear tester is adopted to identify the friction coefficient. Based on this relationship and the theoretical analysis,the rigid-flexible coupling dynamic model of conveyor belt is worked out for simulation. The results show that the stress-strain hysteresis loop of the steel-cord rubber conveyor belt is obtained through a series of experiments,and the relationship between stress and strain is found. Thus,such material parameters as the elastic modulus are calculated to simulate the ST1600 conveyor belt. With the experiment-based parameters,the trapezoidal stress on the cross sections of the conveyor belt at the sink-typed roller support gradually reduces from the middle to the two sides. The stress distribution at the roller is roughly parabola-typed,with the largest stress at the middle of the conveyor belt,and the stress distribution at the transition part is W-shaped.
  • Mordern equipment design technology and analysis of examples
    YU Ming-xing, CHEN Jian-zhang, LI Huai-liang, YU Wen-tai, WANG Fu-shan, MA Tian-liang, LI Jian-nan, WU Shi-peng
    Journal of Machine Design. 2020, 37(2): 115-120. https://doi.org/10.13841/j.cnki.jxsj.2020.02.016
    Thanks to the analysis on the working principle and components of submarine pipeline recovery tools, both the failure mode and the level of influence are worked out by the FMECA analysis. Besides, both the weakest link and the most harmful failure mode in the process of utilization are identified, and then the suggestions for improvement are brought forward.Thus, a series of reliability design, such as the environment-resistance design, the stress-strength design, as well as the verification of function and durability verification, are completed.
  • Mordern equipment design technology and analysis of examples
    WANG Zhi-jun, LIU Lu, LI Zhan-xian, CHEN Li-wen
    Journal of Machine Design. 2020, 37(11): 72-77.
    A six-dimensional force sensor at the base is affected by such factors as the gravity and inertia of the moving robot, which causes the zero change in position. In this article, the algorithm of dynamic force compensation for the six-dimensional force sensor at the base is worked out. Firstly, the algorithm of gravity compensation is derived when the robot is stationary, and the robot model is set up by means of the D-H parameter method and the Newton-Eulerian method for structural analysis. The universal algorithm is derived for the sake of dynamic force compensation when the robot is moving. Secondly, with the KUKA sixdegree-of-freedom robot as an example, the theoretical curve of this numerical example is identified. Finally, the ADAMS software is adopted for dynamic simulation, in order to work out the dynamic force curve of the six-dimensional force sensor at the base when the robot is moving. Thus, it is verified that the theoretical analysis on the algorithm of dynamic force compensation is correct.
  • Mordern equipment design technology and analysis of examples
    XING Yang, SHEN Xiu-min, LI Ming, WANG Xian-guo
    Journal of Machine Design. 2020, 37(9): 112-119. https://doi.org/10.13841/j.cnki.jxsj.2020.09.017
    Based on the computational fluid dynamics (CFD), the numerical-simulation model of automotive air-conditioning is worked out with the aid of the SST two-equation model. With the low utilization ratio of the evaporator monomer's refrigerating capacity to the air-conditioner's refrigerating capacity assembly, Chongqing Sanden's evaporator performance indicator (EAPI) is adopted as the standard to conduct the simulated analysis on the air-conditioner's structural optimization. It's shown that the CFD results are in line with the experimental data, and the deviation of air volume is 1. 29%. When EAPI, which is extremely important and reasonable, increases from 43. 93% to 83. 54%, the utilization ratio of the evaporator monomer's refrigerating capacity to the air-conditioner's refrigerating capacity assembly will rise from 77. 59% to 91. 70%. The volute's expansion section has great influence on the fan's performance, and the effective expansion will increase its air volume. The sectional adjustment of the evaporator's front inlet (step and windshield) ensures a higher standard of evaporator performance.