CN101509883A - Engine oil detector - Google Patents
Engine oil detector Download PDFInfo
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- CN101509883A CN101509883A CNA2008100098803A CN200810009880A CN101509883A CN 101509883 A CN101509883 A CN 101509883A CN A2008100098803 A CNA2008100098803 A CN A2008100098803A CN 200810009880 A CN200810009880 A CN 200810009880A CN 101509883 A CN101509883 A CN 101509883A
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Abstract
The invention relates to a detecting instrument for detecting the engine oil aging property of an engine by utilizing a resistance sensor measurement technology. The engine oil of the engine to be detected is taken as dielectric medium of a resistance sensor; when the engine oil of the engine gradually ages during the use process, a resistance value of the resistance sensor is decreased correspondingly; and the ageing condition of the engine oil of the engine can be judged by relevant detection, converting and display circuits, so as to scientifically determine the time to change the engine oil. The appearance structure of the engine oil detecting instrument consists of a probe (1), a telescopic pull rod (2) and a control box (3), as shown in figure 1. The circuit structure of the engine oil detecting instrument consists essentially of the resistance sensor (1), a digital temperature sensor (2), an electric bridge (3), an operational amplifier (4), an analog-to-digital converter (5), a singlechip (6), a digital display screen (7), a buzzer (8), a data storage device (9), and the like, and a battery is used for supplying power, as shown in figure 2.
Description
One, affiliated technical field
The present invention relates to the measuring technique of electric resistance sensor, utilize the dielectric of tested engine motor oil as electric resistance sensor, when engine motor oil is in use progressively aging, the resistance value of electric resistance sensor reduces thereupon, by coherent detection, conversion and display circuit, can judge the aging performance of engine motor oil, scientifically to determine the more time of change engine oil.
Two, background technology
Use various engines in a large number in the engineering, and machine oil plays the effects such as buffering of lubricated, cleaning, cooling, sealing, anticorrosion and impact load to the work of engine.Therefore, machine oil has important effect to performance of work permanance, reliability, economy and the ability to work of engine etc.Rationally use machine oil is the consumption of reduction engine capacity, alleviates rubbing wear, prolongs the engine important assurance in serviceable life.Because engine motor oil in use is subjected to influences such as high temperature, vibration, friction, pollution, can be progressively aging, its effect of bringing into play will progressively weaken.For this reason, judge that scientifically and rationally the time of the aging machine oil of replacing just seems very important,, will cause the waste of machine oil, and be unfavorable for environmental protection if change oil early; Late if change oil, then easily cause the damage of engine, influence the life-span of engine.For this reason, country promulgation have special " gasoline engine oil criteria for changing oil " (GB/T8028-1994), " diesel engine oil criteria for changing oil " standard such as (GB/T7607-2002), regulation is when a certain in the physical and chemical parameters such as the viscosity of machine oil, moisture, open flash point, acid number, iron content, n-pentane insoluble substance during above limit value, more change engine oil.
Usually, in real work, determine that the replacing time of engine motor oil is mainly adopted two kinds of methods: the one, chemical analysis, promptly regularly it is carried out sample examination, parameter to machine oil is carried out chemical analysis, exceeds limit value if find a certain parameter index, then change engine oil more; The 2nd, empirical method, promptly rule of thumb, when engine accumulative total operation reaches certain hour, or the walking of vehicle accumulative total reaches certain mileage, then change engine oil more.Preceding a kind of method needs special chemical analysis instrument, complicated operation, and the time is long, and efficient is low; Though then a kind of method is simple, and is not accurate enough, easily causes too early or change oil evening excessively.
Three, summary of the invention
Analysis and experiment show that along with progressively wearing out of machine oil, when its chemical constitution changed, its physical property also was a synchronous change, as: the dielectric coefficient of machine oil, conductivity etc. are to change along with the aging of machine oil.This just makes and utilizes physical measurement mode instead of chemical analysis mode to become possibility.Engine oil detector utilizes the electric resistance sensor measuring technique exactly, and with the dielectric of tested engine motor oil as electric resistance sensor, when machine oil was in use progressively aging, the resistance value of electric resistance sensor reduced thereupon.So, measure its changes in resistance, can grasp the ageing properties of machine oil.
Technical scheme of the present invention is:
1. make an electric resistance sensor (as the probe of detection instrument) according to the resistance formula,, and machine oil can be flowed freely between two electrodes of resistor the dielectric of tested machine oil as electric resistance sensor;
2. consider the influence of oil temperature to measurement data, a digital temperature sensor is installed on the probe of detection instrument simultaneously, make probe when measuring the dielectric parameter of machine oil, can measure the temperature of machine oil simultaneously, so that carry out temperature characteristic compensation by scm software;
3. electric resistance sensor detects through an electric bridge, the output dc voltage signal, after operational amplifier amplifies, again through analog to digital conversion circuit, detection signal is converted to digital voltage signal and inputs to single-chip microcomputer, single-chip microcomputer is delivered to digital display screen after handling, and then the shown numeral of digital display screen has just been represented the ageing properties of machine oil;
4. digital temperature sensor can directly input to single-chip microcomputer with coding form with detected oil temperature signal, prestore the family curve of machine oil under different temperatures in the single-chip microcomputer storer, can compensate automatically according to the warm ageing parameter of oil at that time during actual measurement machine oil;
5. for ease of carrying and using, detection instrument is made up of a control enclosure and a Telescopic handle, the built-in single-chip microcomputer of control enclosure, data-carrier store, detect electric bridge, amplifying circuit, analog to digital conversion circuit, digital display screen, button, pilot lamp, components and parts such as hummer, one end of pull bar is installed probe (containing an electric resistance sensor and a digital temperature sensor), the diameter of probe and pull bar is can insert the oil supply hole degree of being of engine motor oil fuel tank, the length of pull bar is can be inserted to the bottom degree of being of engine motor oil fuel tank, the other end of pull bar is fixedlyed connected with control enclosure, and the lead-in wire of two sensors is connected to circuit in the control enclosure through the pull bar endoporus.
6. consider from the angle of the actual use of user, if it is the digital display screen of detection instrument directly shows the resistance value or the output voltage values after conversion of surveying electric resistance sensor, neither directly perceived, also meaningless.For this reason, introduce the notion of " ageing rate ", η represents with symbol, and its span is 0%～100%.The η value is big more, and expression machine oil degree of aging is serious more, if η=0% is expressed as new machine oil, and η=aging criteria for changing oil, the more renew oil of having reached of 100% expression machine oil.The calculating of ageing rate η is as shown in Equation (1):
In the formula: U
0Representative is to measuring the output voltage values of gained, U without the new machine oil that uses
OffRepresentative is measured the output voltage values of gained, U to the machine oil that reaches criteria for changing oil
iOutput voltage values for certain actual measurement machine oil.Like this, the digital display screen of detection instrument shows ageing rate η with the form of number percent, then unusual intuitive and convenient.
7. detection instrument is battery-powered.
The invention has the beneficial effects as follows:
1. engine oil detector can make things convenient for measuring machine oil deterioration performance exactly, determine the suitable more change engine oil time, can avoid changing oil early or late, can bring into play effect, saving machine oil, the minimizing environmental pollution of machine oil to greatest extent, can fully guarantee the normal effectively work of engine again.
2. detection instrument can be when engine quits work machines oil deterioration performance easily, statistics have shown, and temperature compensation function is arranged.If the machine oil degree of aging is when reaching criteria for changing oil, can also be by the hummer warning of sounding, prompting operation person changes oil;
3. the data-carrier store family curve of various machine oil that can prestore in the detection instrument is so can be used for detecting the machine oil of different model, different brands;
4. the control enclosure volume of detection instrument is little, and adopts Telescopic handle, and so powered battery is easy to carry, simple to operate;
5. the detection instrument cost of manufacture is low, and is functional, reliable operation.
Four, description of drawings
The invention will be further described below in conjunction with accompanying drawing.
Fig. 1 is appearance structure schematic diagram of the present invention. Engine oil detector is by probe (1), Telescopic handle (2) and control box (3) Form. When survey meter does not use, disconnect control box power source switch, pull bar may contract to concordant with control box, so that take Band; When using survey meter, with inserting the fuel feed hole of engine motor oil fuel tank after the pull bar stretching, probe is immersed in the machine oil fully, Connect again control box power source switch, handle the associated button on the control box, can show the state that machine oil is aging at control box Data. Survey meter is battery-powered.
Fig. 2 is electric resistance sensor structural representation of the present invention. Two electrodes of electric resistance sensor by two radiuses be respectively R and The coaxial metal cylindrical shell of r (R〉r) forms, and keeps electric insulation between two housings, and non-filler, and tested machine oil can be free Enter slit between two housings as the dielectric of electric resistance sensor, two metal shells are respectively drawn a lead (1) and (2), do For two of electric resistance sensor to outer lead. In the inner housing (radius is r) of probe, imbed a digital temperature sensor and (want Ask with electric resistance sensor to keep electric insulation, not shown in FIG.). Like this, pop one's head in the dielectric parameter of measuring machine oil, Also can measure the temperature of machine oil, so that scm software carries out temperature-compensating to measured value. The height h of cylindrical shell is with sensor Can immerse fully in the machine oil is degree, and its diameter 2R can insert the engine motor oil fuel tank take sensor fuel feed hole is degree, two cylindrical shells The gap R-r of body can flow freely to degree therein with machine oil. The lead-out wire of electric resistance sensor and digital temperature sensor is all through drawing The bar endoporus is connected to circuit in the control box.
Fig. 3 is schematic block circuit diagram of the present invention. The survey meter main circuit will by electric resistance sensor (1), digital temperature sensor (2), Electric bridge (3), operational amplifier (4), analog-digital converter (5), single-chip microcomputer (6), digital display screen (7), buzzer (8) And data storage (9) etc. partly forms. Electric resistance sensor and digital temperature sensor all are installed on the probe, the machine oil dielectric Parameter is delivered to analog-digital converter after electric bridge and operational amplifier detection amplification, the digital voltage signal of its output and digital temperature pass The oil temperature data signal that sensor records is delivered to single-chip microcomputer in the lump, is shown according to gained signal controlling digital display screen by single-chip microcomputer Corresponding data. If the machine oil ageing properties reaches criteria for changing oil, then by the buzzer warning of sounding, prompting operation person changes oil. For Make survey meter can adapt to the machine oil (namely adapting to dissimilar engines) of various different models, different brands, at data storage In prestore various different models, the characteristic curve of different brands under different oil temperatures. Dissimilar the starting of each detection During machine machine oil, should at first detect the once parameter of new (totally) machine oil, this parameter is deposited in the data storage, and by monolithic Machine is judged the model of machine oil and is locked it (still can keep after the outage), so that when normally detecting, single-chip microcomputer can be selected corresponding automatically The characteristic curve of model machine oil.
Five, embodiment
Fig. 4 is one embodiment of the present of invention---the engine oil detector circuit theory diagrams.
1, electric resistance sensor and detection electric bridge, operational amplifier
The below of Fig. 4 is for detecting electric bridge and operational amplifier.Electric resistance sensor Rx is through the arm of its lead-in wire access as electric bridge, and bridge output voltage as shown in Equation (2).Get R2=R4 in the electric bridge, and get the maximal value that the resistance value of R3 may reach more than or equal to electric resistance sensor Rx, can guarantee that then output voltage U b is all the time more than or equal to 0.
Usually, the uneven output voltage U b of electric bridge that is produced by the machine oil ageing properties is very little (for millivolt level signal), must handle after dc amplification circuit amplifies it.For this reason, select the accurate single supply operational amplifier OP777 of U.S. ADI company for use.By the operational amplifier principle of work as can be known, adjust the feedback resistance R7 of OP777 and the ratio of input resistance R6, can adjust enlargement factor, obtain suitable output voltage U f.Like this, when machine oil is in use aging, the resistance Rx of electric resistance sensor will reduce thereupon, and the output voltage U b of electric bridge then increases thereupon, and the output voltage U f of operational amplifier also increases thereupon.Therefore, by detecting the variation of Uf, can learn the ageing properties of machine oil.
2, single-chip microcomputer and peripheral circuit thereof
Single-chip microcomputer is selected the high-performance 8-bit microprocessor AT89C51 of atmel corp for use, and the program storage of 4KB Flash Memory is arranged in its sheet.Circuit such as single-chip microcomputer and A/D convertor circuit, digital display screen, data-carrier store are (for simplifying circuit, components and parts such as crystal oscillator, button, pilot lamp, hummer do not draw among the figure) as shown in Figure 4.
For ease of single-chip microcomputer identification with handle, the analog voltage signal Uf of operational amplifier output should be carried out analog to digital conversion, make it become digital voltage signal and input to single-chip microcomputer.Analog to digital conversion circuit is selected 8 bit data conversion chip ADC0809 for use, and its resolution is 2
-8=1/256, as its reference voltage, then its voltage resolution is 5V/256 ≈ 20mV with the 5V direct supply.ADC0809 has 8 road input signal channels, and (IN0～IN7) is by 3 address wires (gating of ADDA～ADDC).Because of detection instrument only needs the input of 1 road signal,, be converted signal Uf and import thus so, make passage IN0 be in strobe state all the time with ground connection behind 3 address wire short circuits.8 data lines of ADC0809 (msb2-1～lsb2-8) directly be connected with the data bus of single chip computer AT 89C51; The clock signal of ADC0809 (CLOCK) is provided by the ALE/PROG end of AT89C51; The enable signal of ADC0809 (ENABLE) and enabling signal (START) are controlled through the output line (Y7) of two rejection gate 74LS02 and three or eight code translator 74LS138 jointly by read signal end (RD) and the write signal end (WR) of AT89C51 respectively; The EOC signal (EOC) of ADC0809 is delivered to AT89C51 through input and output lead-in wires (P1.7).
For showing the detection data of electric resistance sensor and temperature sensor, detection instrument is selected CM802-2 type LCD display (seeing shown in Fig. 4 upper left side) for use.CM802-2 is 2 row * 8 character point configuration LCD display, and each character all can show ASCII character characters such as arabic numeral, English alphabet, punctuation mark commonly used.8 data lines of CM802-2 (D7～D0) directly be connected with the data bus of single chip computer AT 89C51, Enable Pin (EN) is by an output line (Y6) control of three or eight code translator 74LS138, register selecting side (RS) is by the P1.1 control of AT89C51, and read-write end (R/W) is by the P1.0 control of AT89C51.
3, digital temperature sensor
The lower left of Fig. 4 is a digital temperature sensor.Engine will inevitably generate heat when work, and the resulting electric resistance sensor resistance of the machine oil dielectric under the different temperatures is different.Be the accuracy that guarantees that the machine oil ageing properties detects, the detection data of reply electric resistance sensor are carried out temperature compensation.Through experiment measuring and consult interrelated data and learn, engine is behind long-play, and the maximum temperature that its machine oil may reach is about 120 ℃.It is the 1-wire digital temperature sensor DS18B20 of U.S. DALLAS company that temperature sensing circuit is selected for use, and its circuit connection is seen among Fig. 3 shown in the lower left.DS18B20 is unibus (a 1-Wire Bus) structure, can only be directly changed into serial digital signal with an I/O bundle of lines temperature signal and handle for single-chip microcomputer, need not any additional hardware.Its temperature-measuring range is-55 ℃～+ 125 ℃ (precision is ± 0.5 ℃ in the time of-10 ℃～+ 85 ℃), and temperature is output as 9～12 (serials, able to programme), and be 750ms maximum switching time.DS18B20 can (3～5V) power supplies also can be powered by bus itself by external power source.DS18B20 has advantages such as volume is little, low in energy consumption, is particularly suitable for as temperature probe.The I/O line of DS18B20 links to each other with the input and output of single chip computer AT 89C51 lead-in wire P1.6, and detected temperature coded signal is delivered to single-chip microcomputer.R5 is a pull-up resistor.
4, the detection of machine oil and demarcation
For making detection instrument can be applicable to the detection of various different models, different brands machine oil, need the oil sample of elder generation's various machine oil of extraction when different degree of aging (, to be referred to as X respectively for some parts during design from without the old machine oil of the new machine oil that uses to necessary replacing
0, X
1X
Off, wherein, with X
0Be called " new machine oil ", with X
OffBe called " critical oil "), with chemical method the parameters such as viscosity, flash-point, acid number, impurity and moisture of each oil sample are analyzed, therefrom find out critical oil sample X
Off, measure the output voltage values (being as the criterion) of each oil sample correspondence again with data presented on the LCD screen with detection instrument.As: extract one group of oil sample from certain motor car engine, get one group of experimental data U
0, U
1U
Off(corresponding oil sample X
0, X
1X
OffOutput voltage values).
Like this, N kind machine oil is arranged, just can obtain N group experimental data U
0, U
1U
OffConsider of the influence of oil temperature, also use the output voltage values that oil sample is organized in detection instrument measurement (is a grade with per 5 ℃) under the oily temperature of difference electric resistance sensor resistance Rx.Above experimental data is made form in advance, deposit the data-carrier store EEPROM 2816A (seeing upper right side among Fig. 4) of system in; So that table look-up use during program run.
5, the using method of detection instrument
The data-carrier store EEPROM 2816A that to be provided with a capacity in the detection instrument be 2KB, the N that is used to prestore organizes U
0, U
1U
OffThe temperature curve of data and correspondence and some information in actual use, and can after outage, keep.
When using detection instrument for the first time, earlier its probe is inserted in the new machine oil (not pouring the clean machine oil of fuel tank into), after the energising work, single-chip microcomputer will be according to detected magnitude of voltage U
0Automatically enter look-up routine, from N group U
0, U
1U
OffFind the U of certain group data in the data
0(this moment both must equate), and the memory address of these data deposited in two particular memory location among the EEPROM 2816A (2 * 8=16 position is called " identify unit ").Obviously, the output of detection instrument demonstration at this moment should be " η=0% ".After the outage, detection instrument quits work, but the identify unit information among the EEPROM 2816A can not lost.Identify unit represents to choose certain group U
0, U
1U
Off(after this representative can measure certain machine oil).
After this be that available this detection instrument repeated multiple times detects the ageing properties of this machine oil in different phase: will pop one's head in and insert fuel tank, after the energising work, single-chip microcomputer is obtained the first address of tabling look-up from the identify unit of EEPROM 2816A, directly navigates to the U of certain machine oil
0, U
1U
OffData and curves is again according to measured value U
i, substitution formula (1) can calculate ageing rate η, and delivers to the demonstration of LCD screen.
By above explanation as can be known, have only when engine is changed the machine oil of different model, different brands (this kind situation is actually rare), or when detecting various engine motor oil (this kind situation is also rare) with same detection instrument, just needing will pop one's head in earlier inserts new machine oil, so that single-chip microcomputer upgrades the memory address (another kind of tested machine oil is changed in representative) in the identify unit.
Claims (3)
1, a kind of engine oil detector, its resemblance is: detection instrument is made up of probe, Telescopic handle and control enclosure; Its circuit feature is: detection instrument partly is made up of electric resistance sensor, digital temperature sensor, electric bridge, operational amplifier, analog to digital converter, single-chip microcomputer, digital display screen, hummer and data-carrier store etc.
2, engine oil detector according to claim 1 is characterized in that: with the dielectric of tested machine oil as electric resistance sensor.
3, engine oil detector according to claim 1 is characterized in that: the ageing rate of machine oil adopts following formula to calculate:
In the formula: U
0Representative is to measuring the output voltage values of gained, U without the new machine oil that uses
OffRepresentative is measured the output voltage values of gained, U to the machine oil that reaches criteria for changing oil
iBe the output voltage values of certain actual measurement machine oil, ageing rate η represents with the form of number percent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100098803A CN101509883A (en) | 2008-02-17 | 2008-02-17 | Engine oil detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100098803A CN101509883A (en) | 2008-02-17 | 2008-02-17 | Engine oil detector |
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| Publication Number | Publication Date |
|---|---|
| CN101509883A true CN101509883A (en) | 2009-08-19 |
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ID=41002348
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2008100098803A Pending CN101509883A (en) | 2008-02-17 | 2008-02-17 | Engine oil detector |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101900700A (en) * | 2009-05-26 | 2010-12-01 | 通用汽车环球科技运作公司 | On-vehicle evaluation of oil formulation |
| CN102262037A (en) * | 2011-04-21 | 2011-11-30 | 西安石油大学 | Measuring method and electronic measuring device for oil content and water content in oil tank |
| CN103742226A (en) * | 2013-12-25 | 2014-04-23 | 浙江吉利控股集团有限公司 | Engine oil quality detection device |
| CN106813923A (en) * | 2015-11-30 | 2017-06-09 | 北京华清燃气轮机与煤气化联合循环工程技术有限公司 | A kind of generator bearing failure detector and detection method |
| CN107883147A (en) * | 2017-12-12 | 2018-04-06 | 无锡市飞天油脂有限公司 | A kind of fast lubricant fluid supply apparatus |
| CN109637095A (en) * | 2018-12-28 | 2019-04-16 | 武汉船舶通信研究所（中国船舶重工集团公司第七二二研究所） | A kind of water level detecting alarm control circuit |
| CN110702740A (en) * | 2018-07-10 | 2020-01-17 | 郴州市佳迅电子仪器科技有限公司 | Engine oil quality detection instrument |
| CN111340980A (en) * | 2018-12-18 | 2020-06-26 | 英飞凌科技股份有限公司 | Authentication system and method of generating a multi-component fingerprint for a vehicle |
| CN112796851A (en) * | 2021-01-06 | 2021-05-14 | 三一重机有限公司 | Automatic engine oil replacing system and method |
-
2008
- 2008-02-17 CN CNA2008100098803A patent/CN101509883A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101900700A (en) * | 2009-05-26 | 2010-12-01 | 通用汽车环球科技运作公司 | On-vehicle evaluation of oil formulation |
| CN101900700B (en) * | 2009-05-26 | 2014-03-05 | 通用汽车环球科技运作公司 | On-vehicle evaluation of oil formulation |
| CN102262037A (en) * | 2011-04-21 | 2011-11-30 | 西安石油大学 | Measuring method and electronic measuring device for oil content and water content in oil tank |
| CN103742226A (en) * | 2013-12-25 | 2014-04-23 | 浙江吉利控股集团有限公司 | Engine oil quality detection device |
| CN103742226B (en) * | 2013-12-25 | 2016-03-30 | 浙江吉利控股集团有限公司 | A kind of device detecting machine oil quality |
| CN106813923A (en) * | 2015-11-30 | 2017-06-09 | 北京华清燃气轮机与煤气化联合循环工程技术有限公司 | A kind of generator bearing failure detector and detection method |
| CN107883147A (en) * | 2017-12-12 | 2018-04-06 | 无锡市飞天油脂有限公司 | A kind of fast lubricant fluid supply apparatus |
| CN110702740A (en) * | 2018-07-10 | 2020-01-17 | 郴州市佳迅电子仪器科技有限公司 | Engine oil quality detection instrument |
| CN111340980A (en) * | 2018-12-18 | 2020-06-26 | 英飞凌科技股份有限公司 | Authentication system and method of generating a multi-component fingerprint for a vehicle |
| CN109637095A (en) * | 2018-12-28 | 2019-04-16 | 武汉船舶通信研究所（中国船舶重工集团公司第七二二研究所） | A kind of water level detecting alarm control circuit |
| CN112796851A (en) * | 2021-01-06 | 2021-05-14 | 三一重机有限公司 | Automatic engine oil replacing system and method |
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Application publication date: 20090819 |