| With the development of the automobile industry, automobile has become necessary traffic equipment in people's everyday work and life. It brings human not only benefit but also traffic accidents and environment pollution and the lack of the energy sources at the same time.At present, the increasing oil consumption gives rise to a series of energy problems. The contradiction between the lack of oil supply and vast needs that is leaded by the rapid economy development is obvious. The lack of oil force people to pay attention to the oil economic factor, so many countries establish lots of law about oil consumption.All over the word pay attention to greenhouse effect which brings to gradually becoming warm weather, carbon dioxide is the main factor, the half of greenhouse gas is carbon dioxide. At developed countries, the number of carbon dioxide that is letted by automobile is nearly thirty percent to forty percent of all carbon dioxide. So the law of oil consumption is not only energy problems, but also decreasing pollution problems of carbon dioxide.The rate of the consumption oil is nearly forgotten at one time, now often mentioned because of the increasing oil price. It is not only the most important one of automobile performance evaluation aspects, but also the primary factor that people think of when they intend to buy a car. Many merchants set up the brand of low oil consumption. Thus the oil consumption measuring meter is paid attention to by most of people.The fuel lacked tightly to the automobile put forward a very high request to oil consumption parameter, so the oil consumption meter, as its examination equipments, should also have corresponding accuracy .In the practical process, because the calibrating process of oil consumption meter is more troublesome, causing some clients or the research organizations would not like to calibrate it, let what will do well enough alone. Some oil consumption meter never be calibrated from use to elimination, as for its accuracy, it is no meaning to talk it , The oil consumption meter lose accuracy because of lacking of valid calibrating equipments for completely examine during the period of producing with the usage, this is the main reason that cause the existing oil consumption meter to lose control.As for calibrating method of oil consumption meter, existing method is mainly measuring quality or physical volume through oil consumption calibrating meter during certain time , by comparison the manifestation number of oil consumption calibrating meter and true value, judge it qualified or not. The existing method mainly depends on measuring container, weighing scales,flowmeter and stop-watch, it is carried on by hand and eyes estimation .Although this method can satisfy calibrating request in some certain scope, because of the restriction of the technique development level, but a few obvious weakness is still exist. For example, low automation and artificial error and tedious procedure etc.1. The study of existing oil calibrating meterDomestic and international institutions exist some related calibrating theories, but few can apply to practical use. the engine oil research institution of Tianjin University is more mature in theory as for calibrating equipment of the capacity type .A fuel flow equation is established and deduced by using the stratified flow theory of incompressible viscous fluid. the oil consumption meter is calibrated by measurement fluid accumulated discharge of quality method, .This equipment is made up of sampling system and the electric circuit control system .But this method lower automation degree , calibrating result fluence factor is complex, the real apply is very difficult. Actually most of the factories and measuring organizations depend on measuring container, weighing scales, flowmeter and stop-watch to calibrate the oil consumption meter, In all, the existing oil consumption meter calibrating equipments don't satisfy society need, staying in the further improvement with perfection.2. The structure study of the oil consumption calibrating equipmentsThe oil consumption calibrating equipments is made up of the machine structure part, match part to liquid; the data collect part, the system software part. The machine structure part is the most important part in system; it mainly converts the position signal of liquid into the electricity number by the buoyancy principle. Standard surface inside the container and standard piece surface needs to be designed to make it become bright sheen surface. The liquid presses to match part mainly provide an enough stable adjustable liquid press oil for the calibrating device, it mainly includes electromotor ,liquid pump,overflow valve, back pressure controlled valve, electro-hydraulic proportional pressure and flux valve etc.the appropriate choose of liquid components will make the design of the system reasonable, the function good, install simple, maintain easily. In addition to choose various liquid type to suit the system function, the settled pressure, discharge quantity, install form and performance factors also should be consider. Data collecting system converts simulation signal of force sensor into numeral quantity that computer can identify by amplifier and the A/D conversion .There are a lot of categories of the amplifier , choosing the suitable operation amplifier is a key. This system amplify small signal by the amplifier module. A/D, D/A conversion design mainly consider sampling rate and conversion time etc.this device adopt module PC-6313s to carry out A/D, D/A conversion fuctions, To exalt the applicability of the device, original automation apparatus can change into a simple calibrating apparatus easily, this simple apparatus operate easily and conveniently, is applicable to go out to calibrate. But this apparatus need manual operation basically, the efficiency is low, the calibrating data can't handle by oneself, need to be return to the calibrating center to carry on a data processing and print .Making use of these two suits apparatus satisfy the demand of oil consumption meter calibrating apparatus basically. The software part mainly complete data collection, processing and print function, carry out the automation of the calibration. This system adopt Windows 98 terrace and VC++6.0 system. This performance system delivers the procedure instruction by RS 232 strings of communications, the computer control electric motor, the electromagnetic discharge valve and back pressure Controlled valves by electromagnetic switch .the system carry out filtration wave, safe warning system function by the software system.3. The accuracy study of the oil consumption meterThe main error source of calibrating apparatus put up qualitative analysis, then production error margin, the assemble error margin, the quality diagraph error margin, the collection error margin of data signal etc. We put forward to calibrating project of calibrating apparatus, and have calibrating apparatus trace to origins national basis. We examine the calibrating apparatus by the all-powerful angle scales and precise electronics weighing scales. The accuracy of calibrating apparatus can be guarantee by the above project. 4. The trial identification of oil consumption metes calibrating devicesThese calibrating devices carry on the calibration on two oil consumption meter. The result imply: automatic calibration result fits the analysis in theory.This calibrating system work safely and credibly, process reasonably,calibrte accurately, and the data repeat continually. The system of calibration satisfies the design request, can be applied in calibrating sections and the research organizations, it not only provide assurance for the oil consumption meter accuracy, but also bring a direct economic benefit for the society.
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