Research And Design For Non-contact Crankshaft And Camshaft Measuring Head

Crankshaft and camshaft are the important parts of the automobile engine, and their quality directly affects the performance of the engine. In order to achieve their precise manufacturing, precision measurement equipment is needed to support.Traditional measurement methods have some shortcomings such as accuracy is not high, damage part surface, can not be automated test and so on. So they can not meet the measurement needs. In order to improve the accuracy and efficiency of the crankshaft and camshaft measurement, this article study and design a non-contact measuring head. The method of rotating flat crystal is used to make laser beam scanning the measured object. PIN-type photodiode is used for photoelectric conversion. By measuring the time interval, the size of the object is measured indirectly. This method can achieve high accuracy in a large range. The system consists of light, flat crystal, precision shafting, electromotor, photoelectric detectors, signal processing components and so on.The main contents of this article are summarized as follows:1. The common measurement methods are analyzed, and an appropriate measurement method is introduced for the measurement of crankshaft and camshaft according to the measurement requirements.2. The system is analyzed; mathematical model is constructed, and the specific parameters, design requirements and hardware are given.3. The reverse bias voltage circuit, trans-impedance amplification circuit and time point discrimination circuit are designed to ensure accurate measurement of the signal along.4. The system error analysis is made. The effect generated by beam tilt, not paralleled flat crystal surface and time measurement on the measuring system is studied. According to the requirements of precision, demands is made on these components. According to the mathematical model, simulation is made to obtain the relationship between the time and the exit beam position.5. Experiment about the circuit board to process the signal of the PIN tube is made to verify the circuit functionality. ]...