Design And Implementation Of Vehicle-Mounted Hydraulic Oil Particle Counter For Mining Dumpers

With the development of mining industry and large-scale industry construction project, it was a sharp increase for mining dumpers being applied in open-pit mines, quarries and large construction sites.The contamination of hydraulic oil directly affected the normal operation of mining dumpers,owing to hydraulic oil being used as the working medium of transmitting power and providing lubrication for hydraulic transmission system of mining dumpers. In order to guarantee the normal opeartion of mining dumpers and decline the failure rate, it is necessary to detect hydraulic oil pollution of mining dumpers.The regular off-line detection method, which required a longer period and was easily affected by the external factors, was used in hydraulic oil contamination, this can result in whether hydraulic oil contamination exceeds the normal level cannot be found in time. Therefore, it has very important practical significance to design an instrument which can measure hydraulic oil pollution of mining dumpers in real time.In this paper, through analysing a variety of methods of hydraulic oil pollution detection, and at present applying solid particles to evaluate contamination of hydraulic oil at home and abroad, a vehicle-mounted hydraulic oil particle counter based on light blockage method was designed for mining dumpers applying PIC MCU and photoelectric sensor.According to the performance of hydraulic oil particle counter, a overall scheme was designed by adopting the modular method, including the design of size of the measurement area,the hardware circuit, and the software. The size of the measurement area was designed on the basis of the characteristics of the particle size. The hardware circuit design mainly consisted of the signal acquisition module, microcontroller module and flow control module. The signal acquisition module was the core part of the hydraulic oil particle counter, and its function was to converted optical signals to the particle numbers.The PIC16F877A MCU was used as the core of micro-controller module, and its main function was to control the start and stop of particle counting, set the threshold value of particles, remind the hydraulic oil contamination when it exceeded the range of normal value, and realize the data communication.The function of the flow control module was to make the hydraulic oil flow through the particle measurement area at a steady speed. On the foundation of hardware circuit design, the software design which applied C language in the MPLAB software development environmentwas completed in order to detect the hydraulic oil contamination for mining dumpersin real time.In the laboratory, the whole and partial function of particle counter were measured and anlayzed through building the experiment platform and configuring hydraulic oil with different sizes of standard particle. The experimental results show that the particle counter, which was designed in this paper, can detect the number of hydraulic oil particle sizes of >4μm,>6μm and >14μm and the level of hydraulic oil contamination on the basis of the standard of ISO4406. The repeatability of the counting results of the hydraulic oil particle counter is less than 4% and the deviation between the particle detection value and the calibration value is less than ±3%, when the hydraulic oil flow rate is in a certain range. This indicates that it has high reliability and stability for the results of hydraulic oil particle counter.