Influence of eddy current on transient characteristics of common rail injector solenoid valve was studied in this paper. Experimental investigations of drive current and power source volt- age of both drive current as...Influence of eddy current on transient characteristics of common rail injector solenoid valve was studied in this paper. Experimental investigations of drive current and power source volt- age of both drive current ascending and descending process were conducted on a common rail injec- tor solenoid valve. A new discretizing calculation method of solenoid valve flux linkage was put for- ward for the first time based on the experimental results and drive circuit principle, and flux linkage of both drive current ascending and descending process were evaluated. New inductance calculation methods for drive current ascending and descending process respectively were also presented. Influ- ence of parasitic inductance was evaluated. Results indicate that the air gap, under which the transi- ent flux linkage of the solenoid valve is the biggest, varies with drive current due to eddy current. Flux linkage of drive current descending process is bigger than that of drive current ascending process under the same drive current and the same air gap width. Eddy current can reduce the delay between the time that drive current begins to descend and the time that armature begins to move downward. Inductance of drive current descending process is bigger than that of drive current as- cending process over larger scope of drive current, but the difference becomes smaller with the in- creasing of air gap width. The differences of both flux linkage and inductance between drive current ascending and descending process are caused by the eddy current in core and armature materials.展开更多
The injector is the most critical and vulnerable part of a diesel engine, and injector remanufacturing seems to be a solution to change the adverse market conditions. For remanufactured injector, there are some differ...The injector is the most critical and vulnerable part of a diesel engine, and injector remanufacturing seems to be a solution to change the adverse market conditions. For remanufactured injector, there are some differences between China and developed countries. These differences make a different remanufacturability. New remanufacturing process should be evaluated to determine the feasibility. Fuqiang Power Company's experiment and the survey from Bosch Diesel Centers(BDCs) show the status of the used injectors that nearly one-third of the used injector can be remanufactured with low cost. It is feasible to produce quality remanufactured injector under given process. Promoting clean diesel engine is more likely to be accepted by the consumer.展开更多
Fuel injection timing is an important control parameter for engine combustion optimization and emissions control. However, the actual fuel injection timing is different from the nominal one commanded by the electronic...Fuel injection timing is an important control parameter for engine combustion optimization and emissions control. However, the actual fuel injection timing is different from the nominal one commanded by the electronic control unit, due to the system hydraulic lag or the possible communication malfunction. In this study,a simple estimate approach based on the injector inlet pressure is proposed to capture four critical characteristic instants at the start and end of injection. The critical characteristic moments estimated using this pressure-based approach are validated against those determined by the actual injection rate profiles, in the context of different single or split injection processes. The comparison revealed that the characteristic injection moments estimated by the injector inlet pressures and those determined by the actual injection rate profiles have a satisfactory agreement, certifying the broad applicability and reliability of this pressure-based approach in the detection of the real fuel injection start and end time.展开更多
基金Supported by the National Natural Science Foundation of China(51076014)the Research Fund for the Doctoral Program of Higher Education(20101101110011)
文摘Influence of eddy current on transient characteristics of common rail injector solenoid valve was studied in this paper. Experimental investigations of drive current and power source volt- age of both drive current ascending and descending process were conducted on a common rail injec- tor solenoid valve. A new discretizing calculation method of solenoid valve flux linkage was put for- ward for the first time based on the experimental results and drive circuit principle, and flux linkage of both drive current ascending and descending process were evaluated. New inductance calculation methods for drive current ascending and descending process respectively were also presented. Influ- ence of parasitic inductance was evaluated. Results indicate that the air gap, under which the transi- ent flux linkage of the solenoid valve is the biggest, varies with drive current due to eddy current. Flux linkage of drive current descending process is bigger than that of drive current ascending process under the same drive current and the same air gap width. Eddy current can reduce the delay between the time that drive current begins to descend and the time that armature begins to move downward. Inductance of drive current descending process is bigger than that of drive current as- cending process over larger scope of drive current, but the difference becomes smaller with the in- creasing of air gap width. The differences of both flux linkage and inductance between drive current ascending and descending process are caused by the eddy current in core and armature materials.
基金the National Natural Science Foundation of China(No.51675343)
文摘The injector is the most critical and vulnerable part of a diesel engine, and injector remanufacturing seems to be a solution to change the adverse market conditions. For remanufactured injector, there are some differences between China and developed countries. These differences make a different remanufacturability. New remanufacturing process should be evaluated to determine the feasibility. Fuqiang Power Company's experiment and the survey from Bosch Diesel Centers(BDCs) show the status of the used injectors that nearly one-third of the used injector can be remanufactured with low cost. It is feasible to produce quality remanufactured injector under given process. Promoting clean diesel engine is more likely to be accepted by the consumer.
基金the National Natural Science Foundation of China(No.51306114)
文摘Fuel injection timing is an important control parameter for engine combustion optimization and emissions control. However, the actual fuel injection timing is different from the nominal one commanded by the electronic control unit, due to the system hydraulic lag or the possible communication malfunction. In this study,a simple estimate approach based on the injector inlet pressure is proposed to capture four critical characteristic instants at the start and end of injection. The critical characteristic moments estimated using this pressure-based approach are validated against those determined by the actual injection rate profiles, in the context of different single or split injection processes. The comparison revealed that the characteristic injection moments estimated by the injector inlet pressures and those determined by the actual injection rate profiles have a satisfactory agreement, certifying the broad applicability and reliability of this pressure-based approach in the detection of the real fuel injection start and end time.
