The Online Testing System For Oil Control Valve And Actuator Of Variable Valve Timing Engine

OCV is the oil control valve of VVT engine, which determines when the intake valve open and close. The main purpose of actuator is to change the camshaft phase. The manufacture of OCV and actuator is a multidisciplinary, high-precision process and products must undergo a rigorous inspection. The testing system for OCV and actuator is very advanced abroad, while few manufacturers of our country can produce the equipments. In order to improve the rate of qualified products, the efficiency of production, reduce the costs and achieve the localization of OCV, this subject starts to develop a online testing system.On the basis of the analysis of OCV and actuator performance, this subject determines the technical parameters, designs a valuable testing program, and completes fully functional, high precision, reliable online testing system. According to practical needs, the whole system is divided into actuator phase testing system and the OCV spool displacement measurement system. Phase testing system has two main functions:Monitoring OCV characteristics in signals of different duty cycle and locating duty cycle range of advance, delay and close; Monitoring the maximum stroke angle of implementation. Displacement test system is mainly to monitor OCV spool displacement in different duty cycles. The online testing system includes simulated control signal system of automobile engine, data acquisition system, and sensors. This paper completes the following tasks:the lower computer program receives instruction, examines data, feedbacks information and outputs PWM control signal. Hardware platform of phase testing system includes sensors and the data acquisition system which collects the data from sensor system. MCU of spool displacement testing system receive date, output signal and show the result. The hardware drives the oil control valve.Compared with the traditional testing method, the simulated cam system and computer data sampling system monitors the dynamic characteristics of actuator and the performance of OCV in various conditions. Due to production processes, the spool displacement of OCV can reduce the defect rate and control the cost of production. At the last of this paper, the author summarizes the whole work of this text, looks ahead to the next step and puts forward scheduled program for the existing problems. This will help improve the precision, efficiency and stability of online testing system.