A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment.The accuracy of the model is validated through comparison with e...A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment.The accuracy of the model is validated through comparison with experimental data.The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed.In the spill control valve mode,main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time.In the needle control valve mode,main-injection fuel quantity increases with rising multi-injection dwell time;this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths.Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes;the variation in main-injection quantity is in the range of 1 mm3.展开更多
This paper presents a bi-directional permanent-magnet linear actuator for directly driving electrohydraulic valves with low power consumption. Its static and dynamic performances were analyzed using the 2D finite elem...This paper presents a bi-directional permanent-magnet linear actuator for directly driving electrohydraulic valves with low power consumption. Its static and dynamic performances were analyzed using the 2D finite element method,taking into account the nonlinear characterization and the eddy current loss of the magnetic material. The experiment and simulation results agree well and show that the prototype actuator can produce a force of ±100 N with the maximum power being 7 W and has linear characteristics with a positive magnetic stiffness within a stroke of ±1 mm. Its non-linearity is less than 1.5% and the hysteresis less than 1.5%. The actuator's frequency response(-3 dB) of the displacement reaches about 15 Hz,and the most significant factor affecting the dynamic performance is identified as the eddy current loss of the magnetic material.展开更多
A new approach to improve the matched responses of high-speed PWM mode electro pneumatic actuators is introduced. By modifying the control signal, the matched responses are highly improved. For testing this new approa...A new approach to improve the matched responses of high-speed PWM mode electro pneumatic actuators is introduced. By modifying the control signal, the matched responses are highly improved. For testing this new approach, an instrument is designed and developed. And the effectiveness of the approch is proved by experiment. The block diagram of the instrument is also presented.展开更多
The precise hydraulic valve is widely used in various industrial fields like aircraft, automobile and general machinery. Linear actuator is the most important device for driving the precise hydraulic valve. The reliab...The precise hydraulic valve is widely used in various industrial fields like aircraft, automobile and general machinery. Linear actuator is the most important device for driving the precise hydraulic valve. The reliable operation of linear actuator has effects on the overall hydraulic system. The performance of linear actuator relies on frequency response and step response according to arbitrary input signal. In this paper, the analysis for the components of linear actuator is performed to satisfy the reliable operation and response characteristics through the reliability analysis, and also deducted the design equations to realize the reliable operation and fast response characteristics of voice coil type linear actuator for servo valve operation through the empirical knowledge of experts and electromagnetic theories. The design equations are suggested to determine the values of design parameters of linear actuator as like bobbin size, length of yoke and plunger and turn number of coil, and calculated the life test time of linear actuator for verification of reliability of the prototype. In addition, for reducing the life test time, the acceleration model of linear actuator is proposed and the acceleration factor is calculated considering the field operating conditions. And then, the achieved design values are verified through accelerated life test and performance tests using some prototypes of linear actuators adapted in servo valve.展开更多
High voltage circuit breakers are the most important protection and control apparatus in power system. As a core part of circuit breakers, the operating mechanisms have a trend to be hydraulic-style in high voltage po...High voltage circuit breakers are the most important protection and control apparatus in power system. As a core part of circuit breakers, the operating mechanisms have a trend to be hydraulic-style in high voltage power grid. Compared with other hydranlic systems, the hydraulic operating mechanisms have the characteristics of high hydraulic pressure, high speed, high power and long-term waiting etc., and it is because of the characteristics that the hydraulic operating mechanisms become dif- ficult to be developed and have been arousing significant study interest from more and more researchers as well as their promising applications. Therefore, it is significant to summarize the hydraulic operating mechanisms on their development, characteristics, and key technologies etc. In this review, the evolution process and recent studies of hydraulic operating mechanisms at home and abroad are viewed. The review then focuses on the characteristics and key technologies of hydraulic operating mechanisms, especially on time and velocity characteristics, high-speed cylinder cushioning, fast response and great flow rate control valve, temperature compensation, system monitoring and fault diagnosis, intelligent operation, energy storage module, etc. In the end, the future trends of this field are presented.展开更多
基金Supported by the Program for New Century Excellent Talents in University（NECT-11-0826） the National Natural Science Foundation of China（NSFC 51279037）+1 种基金 the Fundamental Research Funds for the Central Universities（HEUCFZ13） the Postdoctoral Science-research Developmental Foundation of Heilongjiang Province（LBH-Q12126）Acknowledgement The authors gratefully acknowledge vice Professor Yong Shi and Jun Sun＇s help in fuel injection experiment.
文摘A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment.The accuracy of the model is validated through comparison with experimental data.The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed.In the spill control valve mode,main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time.In the needle control valve mode,main-injection fuel quantity increases with rising multi-injection dwell time;this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths.Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes;the variation in main-injection quantity is in the range of 1 mm3.
文摘This paper presents a bi-directional permanent-magnet linear actuator for directly driving electrohydraulic valves with low power consumption. Its static and dynamic performances were analyzed using the 2D finite element method,taking into account the nonlinear characterization and the eddy current loss of the magnetic material. The experiment and simulation results agree well and show that the prototype actuator can produce a force of ±100 N with the maximum power being 7 W and has linear characteristics with a positive magnetic stiffness within a stroke of ±1 mm. Its non-linearity is less than 1.5% and the hysteresis less than 1.5%. The actuator's frequency response(-3 dB) of the displacement reaches about 15 Hz,and the most significant factor affecting the dynamic performance is identified as the eddy current loss of the magnetic material.
文摘A new approach to improve the matched responses of high-speed PWM mode electro pneumatic actuators is introduced. By modifying the control signal, the matched responses are highly improved. For testing this new approach, an instrument is designed and developed. And the effectiveness of the approch is proved by experiment. The block diagram of the instrument is also presented.
文摘The precise hydraulic valve is widely used in various industrial fields like aircraft, automobile and general machinery. Linear actuator is the most important device for driving the precise hydraulic valve. The reliable operation of linear actuator has effects on the overall hydraulic system. The performance of linear actuator relies on frequency response and step response according to arbitrary input signal. In this paper, the analysis for the components of linear actuator is performed to satisfy the reliable operation and response characteristics through the reliability analysis, and also deducted the design equations to realize the reliable operation and fast response characteristics of voice coil type linear actuator for servo valve operation through the empirical knowledge of experts and electromagnetic theories. The design equations are suggested to determine the values of design parameters of linear actuator as like bobbin size, length of yoke and plunger and turn number of coil, and calculated the life test time of linear actuator for verification of reliability of the prototype. In addition, for reducing the life test time, the acceleration model of linear actuator is proposed and the acceleration factor is calculated considering the field operating conditions. And then, the achieved design values are verified through accelerated life test and performance tests using some prototypes of linear actuators adapted in servo valve.
基金This work was supported by the National High Technology Research and Development Program of China (Grant No.2007AA041803)Doctoral.Programs Foundation of Ministry of Education of China (Grant No.20090101110041)Program for New Century Excellent Talents in University
文摘High voltage circuit breakers are the most important protection and control apparatus in power system. As a core part of circuit breakers, the operating mechanisms have a trend to be hydraulic-style in high voltage power grid. Compared with other hydranlic systems, the hydraulic operating mechanisms have the characteristics of high hydraulic pressure, high speed, high power and long-term waiting etc., and it is because of the characteristics that the hydraulic operating mechanisms become dif- ficult to be developed and have been arousing significant study interest from more and more researchers as well as their promising applications. Therefore, it is significant to summarize the hydraulic operating mechanisms on their development, characteristics, and key technologies etc. In this review, the evolution process and recent studies of hydraulic operating mechanisms at home and abroad are viewed. The review then focuses on the characteristics and key technologies of hydraulic operating mechanisms, especially on time and velocity characteristics, high-speed cylinder cushioning, fast response and great flow rate control valve, temperature compensation, system monitoring and fault diagnosis, intelligent operation, energy storage module, etc. In the end, the future trends of this field are presented.
