JPS58129235A - Fuel property detector - Google Patents

Abstract

PURPOSE:To decrease the change in the lapse of time, by irradiating light to a fuel from the outside or inside of the fuel and measuring the refractive index of light generated at the time of emanating the transmitting light transmitted the fuel from the liquid face of the fuel to gas. CONSTITUTION:A fuel property detector 31 is provided on the side of a cap 22 of a fuel injection pipe 21 of a fuel tank 4 and a measuring signal of this detector 31 is inputted into a control circuit 9 consisting of a microcomputer, etc. The fuel in the tank 4 measured its property by the variation of refractive index of light by the detector 31 at the time of injecting the fuel, is compressed by a pump 6 and the compressed fuel is set at a prescribed pressure by a regulator 8 and then, said fuel is sent to a fuel jetting valve 3. Opening and closing time and time width are controlled by carrying out operational processing of each signal of a crank angle sensor 11, a water temperature sensor 12, a throttle valve opening degree sensor 15 and a detector 31 by a control circuit 9 and compared with a correction factor stored in a storage circuit and then commanded from the circuit 9 to actuators such as a fuel jetting valve 3, an ignition plug 20, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a senna for measuring the properties of fuel supplied to combustors of automobiles, aircrafts, etc., and is particularly suitable for non-contact measurement of low quality fuel properties. Fuel property detection! Regarding 11.

There are methods to measure the capacitance and determine the properties of the fuel from the dielectric constant of the fuel itself, and methods to know the properties of the fuel by irradiating the fuel with infrared mt-rays and measuring its absorption. However, the former method has disadvantages in that the measurement changes over time, and the latter method has the drawbacks of high costs, which are obstacles to practical use.

Here, a glimpse of a conventional fuel supply system is shown below. Engine lo @ downstream of throttle valve 2 in the trachea.

A fuel injection valve 3 is installed, and fuel is supplied to the fuel injection valve 3 from a fuel tank 4 through a filter 5, a bomb, a surge tank 6, and a V regulator 8t. Further, an output signal from a control circuit 9 that determines an appropriate amount of fuel is input to the fuel injection valve 3. This control circuit 9 includes
Crank angle sensor 11 linked to the crankshaft 10. A water temperature sensor 12, an oxygen sensor 14 installed in the exhaust pipe 13,
Output signals from various sensors such as a throttle valve opening sensor 15 linked to the throttle valve 9 valve 2 and a hot wire sensor 18 provided in a bypass passage 17 through which air from the air cleaner 16 passes are input. Further, the output signal of this control circuit 9 is outputted to an ignition coil 19, and this ignition coil 19 is electrically connected to a spark plug 20 attached to the engine 1.

Next, an example of the cross-sectional structure of the fuel tank 4 is shown in FIG.

When the cap 22 attached to the tip of the fuel injection pipe 21 inserted into the fuel tank 4 is removed and fuel is injected into the fuel injection pipe 21, the fuel spreads into the tank through the vibration isolating plate 23. Fuel level increases. This liquid level rises at the trench where the overflow prevention pipe 24 is clogged, and the amount of remaining oil is notified by the fuel level sensor 26 to which the float 25 is connected. Note that the pipe 27 is an oil feed pipe connected to the pump shown in Fig. 1, the pipe 28 is a return tube connected to the discharge side of the pump 6, and the pipe 29 is a paper recovery pipe for discharging hot air from the tank. The fuel inside is discharged to the outside by opening the drain 3o.

When a low-quality fuel such as an alternative fuel is used in such a conventional fuel supply system, the mixture ratio, which is the ratio of fuel to air, cannot be fully controlled. Therefore, it is essential to control the mixing ratio according to the properties of the fuel, and it is desired to develop a fuel property detector with good I@O properties.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a fuel property detector that is low in cost and has little change over time.

This book focuses on the fact that when a light beam is irradiated from the air into a liquid or from a liquid into the air, the path of the light beam at the gas-liquid interface differs depending on the physical properties of the irradiated liquid. The properties of the fuel are measured by irradiating light and measuring the angle of refraction of this light on the two sides of the gas and liquid.

Embodiments of the present invention will be described below with reference to the drawings, using the same reference numerals for the same parts as in the conventional art.

FIG. 3 shows the configuration of a fuel supply system equipped with an embodiment of the fuel property detector of the present invention! This is a clear diagram.

A fuel property detector 31 is provided at the middle end 22H of the fuel injection pipe 21 of the fuel tank 4. The measurement signal from the fuel property detector 31 is input to a control circuit 9, which is comprised of a micro combinator or the like. A fuel tank 4 whose properties are measured by a fuel property detector 31 when fuel is injected.
The fuel in the intake pipe 3 is passed through the filter ST, is pressurized by the pump 6, is set to a predetermined pressure by the V regulator 8, and is sent to the intake pipe 3.
The fuel is sent to the fuel injection valve 3 attached to the fuel injection valve 2. The opening timing and duration of the fuel injection valve 8 are controlled by the angle sensor 11. Water temperature sensor 12. Each signal from the throttle valve opening sensor 15 and the fuel property detection 'a31 is taken into the control circuit 9, where it is arithmetic processed, compared with the correction factor stored in the storage circuit, and the signal is sent to the fuel injection valve 31. This is done by sending commands from this control circuit 9 to actuators such as the spark plug 20. Note that the reference numeral 33 indicates an intake valve, the reference numeral 34 an exhaust valve, and the reference numeral 35 a battery that supplies power to the control circuit 9 and the like.

Here, in fact, m1fii's fuel property detector 31 (iD
The configuration will be explained in detail. This fuel property detector 31 is
Fuel properties are detected by utilizing the fact that the refractive index of light that passes through changes due to differences in the physical properties of the fuel. FIG. 4 shows the change in the refractive index of light depending on the component ratio of a conventional fuel mixture of Ganlin and methanol. That is, when pure gasoline has a refractive index of 1.51 in n, it changes to 1.4 in n when 40% methanol is mixed. As a result, it can be seen that the refractive index of light changes uniquely as the methanol mixing rate increases.

FIG. 5 shows an example of a method for measuring the refractive index of light transmitted through a liquid. A solid transparent body 36 having a triangular prism shape with a known refractive index (nl) and a hollow transparent body 37 of the same shape are shown in FIG.
The hollow transparent body 37 is filled with a liquid having an unknown refractive index n. When a light beam is incident from a perpendicular direction onto the surface that meets the bottom of the hollow transparent body 37, the refractive index n of the unknown liquid is expressed by the following equation.

11=jl, -δ・cot tp ・−・−
(1) However, - indicates the exit angle, and the refractive index n can be determined from equation (1) if the exit angle δ and the apex angle ψ of the triangular prism are known. The solid transparent body 36 with a refractive index n is
It functions as a refractive index intensifier 111i, and the measurement time is 1 it.
- Focus on things that will improve you. Therefore, the path of the ray is ABC
With DE, the refractive index of an unknown liquid can be determined by placing a light detector on the D axis.

FIG. 6 shows the fuel property detection i! of the nine embodiments shown in FIG. 3
1 shows a specific configuration example of No. 1. A triangular prism-shaped solid transparent body 36 and a hollow transparent body 37 are attached to a frame 38 so that their apex angles are in opposite directions. The light from the light source 39 passes through the slit 40 and becomes a light beam, which enters the hollow transparent body 37 from a direction perpendicular to the bottom surface of the hollow transparent body 37, passes through the solid transparent body 36, and reaches the light amount detection plate 41. reach. A slit 42 whose width gradually becomes narrower is formed in this light J1 side output plate 41. The light beam passing through this slit 42 is reflected by a condensing lens 43 and condensed onto a detector 44 . This detection 44 is converted into optical t-electrical polarization and transmitted to the control circuit 9. Depending on the nature of the fuel placed in the hollow transparent body 37, the light beam passing through it is refracted as shown in the figure and hits the slit 42 of the light amount detection plate 41, but if the refractive index is large, the slit 42 in the wide part
If the refractive index is small, the change in the refractive index passes through the narrow slit 42 and reaches the detector 44. It can be captured.

FIG. 7 shows the relationship between the amount of light I and the mixing rate of methanol mixed into the fuel in the above case. The electrical signal corresponding to the light intensity of the round detector 44 having such a relationship is based on the properties of the fuel in the hollow transparent body 37 (methanol mixing rate).
This means that it is detecting.

FIG. S shows another specific example of the structure of the fuel property detector 31 of this embodiment, in which a plurality of 7-point detectors 45 are arranged in place of the light amount detection plate 41, and a solid structure is used. It receives light rays that have passed through the transparent body 36 and the hollow transparent body 37. The output side of the photodetector 45 is connected to a selection circuit 46.

The output of this O selection circuit 46O is input to the control circuit 9. In this case, because the light beam hits the photodetector 45 which is ^ due to the difference in the refractive index of the fuel, it is possible to know the shoulder refractive index by identifying the photodetector 45 that has hit the light beam Q using the selection circuit number 6. The mixing rate of methanol can be calculated from the refractive index of .

9vA uses the above fuel property detector 31 in the fuel tank 4KM.
Let's look at an example of the configuration when wearing skin. The triangular prism tube of the hollow transparent body s7 is inserted in the middle of the fuel injection tube 110 inserted into the tank, and when fuel is flowed into this hollow transparent body, that is, when fuel is injected into the fuel mentor 4, the fuel I'm trying to detect the properties.

6. No. 10 #A shows another embodiment of the fuel property detector of the present invention. & The next light ray irradiated from the light source number 7 passes through the lens system 4$, the mirror 49, and the V/Z 5G to become a parallel ray, and is radiated onto the fuel Kjl in the fuel tank 4. A portion of the irradiated light beam is transmitted through the fuel, and this transmitted light beam is received by the detector 51.

The detector 51 is equipped with a guide tube 54t in front of the detection section 520 and 53, and the detection section 5[)jlE section has a light amount detection 1i! which detects the amount of light passing through the window 53. 5
5 is provided. The output signal of this light amount detection-55 is the output terminal! This output end 56 is pulled out to the outside from $6.
is connected to a control circuit (not shown). Incidentally, the window 53 is made of glass or the fence 11, and is equipped with a detector 51t.

A detector s1 provided at a fixed position detects the amount of scattered light in a predetermined range within the liquid using a light amount detector s5. This detected amount is due to the amount of light transmitted through the fuel.

Since p changes depending on the refractive index of the gas and liquid of this fuel, it changes according to the refractive index. Therefore, the fuel property detector having such a configuration can also detect the mixing rate of methanol in the fuel. Note that the guide tube 5 of the detector 51
4 is preferably immersed in the fuel at all times, and the guide cylinder 54 is preferably set at a position where it can be detected even when the fuel runs out.

FIG. 11 shows the j! of the fuel property detector of the present invention. Another example is shown in FIG. The light emitted from the light source 47 passes through the lens 57. The light passes through the slit 58 and enters the optical fiber 89 . This optical fiber s9 is inserted into the fuel tank 4 from the bottom, and the light is incident on the optical fiber 59 and then irradiated into the fuel in the fuel tank 4 from the other end of the optical fiber s9. be done. When this irradiated light exits from the fuel liquid surface, it undergoes KJII bending and enters the light amount detection 941.

This light amount detection plate 41 is similar to that shown in FIG. 6, and is provided with a slit 40 whose width varies.

A change in the emission angle of this friendly light beam is converted into a change in light amount by the light amount detection plate 41, and the light is received by a detector similar to eml (not shown). In this embodiment, an optical 7-eyeper 59 that allows light to enter the fuel from any angle direction is used.
The mixing rate of methanol in the fuel can be detected using the thick layer, which has the same characteristics as the embodiment shown in the xi diagram.

Fig. 12 shows a part of the case where a fuel property detector using this optical 7 AINO is installed in a fuel tank.The optical fiber 59 is inserted from the liquid level in the fuel tank 4, and the tip is bent into a five-figure shape.

FIG. 13 shows another example in which the fuel property detector for the optical 7<tw> is attached to the fuel tank. The optical fiber 59 is immersed deeply from the fuel liquid level in the fuel tank 4, and its tip near the bottom of the fuel tank 4 is bent into a 5-shape. fuel tank 4
A transparent window 60 with a known refractive index is provided on the side wall near the bottom of the
is provided, and the tip of the optical fiber 59 is directed toward the transparent window 60. This transparent window 6
A plurality of 7 photodetectors 45 are arranged on the outside of the fuel tank 4 facing G, and these photodetectors 45
The output side of is input to the selection circuit 46, and this selection circuit 46
The output of is input to the control circuit 9. Additionally, a propeller 62 rotated by a motor 61 is inserted into the fuel in the fuel tank 4.

When the light that has passed through the optical 7 eyeper 591 is irradiated into the fuel, when it exits from the fuel into the air through the transparent window 60, the light is refracted and received by one of the 7 Oto detectors 4s arranged in plurality. The zero selection circuit 46 determines which photodetector 45 receives the light, and inputs this determination signal to the control circuit 9. In the control circuit 9,
The refractive index is calculated from the position of the photodetector 4B that receives the light.

The mixing rate of methanol in the fuel is calculated based on the fourth graph. Note that the propeller 62 stirs the fuel in the tank to make it homogeneous. In this gA-example, the optical fiber 59 is used to irradiate light near the bottom of the fuel tank 4, which has the effect of completely preventing measurement errors that may occur due to fluctuations in the fuel fl level in the tank 4. In particular, in embodiments other than this embodiment, there is a concern that #j constant error may occur due to fluctuations in the fuel level in the fuel tank 4, but if the fuel property detection tube a is used to measure immediately after fuel injection, the fuel The above problem does not occur because the liquid level is adjusted.

According to each of the above embodiments, light is irradiated onto the fuel in the fuel tank 4, and the change in the refractive index of this light is detected as a change in the amount of light by the detector 4.
4, or by receiving the light by the detector 51, or by selectively receiving the refracted light by a plurality of photodetectors 45.

The effect can be detected on the fuel properties in the fuel tank 4 (in this case, the mixing rate of methanol in the fuel) t-storage. In addition, since the structure is relatively simple and it can be installed on tables already on the market, it has the advantage of being able to accurately measure fuel properties at low cost. This has the effect of minimizing changes in detected values over time. Furthermore, *
Since the hollow transparent body 37 can amplify the refractive index as in the embodiment shown in aZ, it has the effect of facilitating measurement and improving the Fuchishing precision IiL. Furthermore, in any of the embodiments, when fuel is injected into the fuel tank, its properties can be detected. In addition, in the above example, i1! regarding the fuel properties and the mixing rate of methanol in 41! However, the present invention is not limited to the mixing rate of methanol, and it is possible to detect the properties of various types of fuel from its refractive index. Further, the light source may be either white light or monochromatic light, but it is desirable to select light 4Iil with a wavelength that is difficult to be absorbed by the fuel to be measured.

As described above, according to the fuel property detector of the present invention, it is possible to reduce the cost and change over time.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing part of a conventional fuel supply system, Figure 2
The figure shows an example of the structure of a conventional fuel tank, Figure 3 is a configuration diagram of a fuel supply system equipped with an embodiment of the fuel property detector of the present invention, and Figure 4 shows the methanol mixing rate in gasoline. 5 is an explanatory diagram showing the constant raw salt of the embodiment shown in FIG. 3, and FIG. 6 is an embodiment of the fuel property detector of the present invention. FIG. 7 is an explanatory diagram showing the relationship between the methanol mixing rate in fuel and the amount of light. FIG. 8 is an explanatory diagram showing another configuration example of the fuel property detector shown in FIG. 6. , ljgQ is an explanatory diagram showing the next side of the fuel property detector shown in Fig. 6 or 8 attached to the fuel port, and Fig. 1θ is another embodiment of the fuel property detector of the present invention. 11 to 13 are explanatory diagrams showing other examples of impurities in the gloss of the fuel property detector of the present invention. 9... Control circuit, 36... Solid transparent body, 37...
Hollow transparent body, 39.47... Light source, 40.42.58
...Slit, 41...Photoelectric detection plate, Shito...Condensing lens. 44...detector, 45...photodetector%46.
...Selection circuit, 48...Lens system, 49...Mirror, 50°5 lens, 51...Detector, 54
-...Guide tube. ' 20 40 5Q 80 1Q (1
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Claims (1)

[Claims] 1. A means for irradiating the fuel with light from outside or inside the fuel, and this irradiation light is applied to 1% of the fuel from the air [when it enters the bacteria,
Alternatively, a fuel property detector characterized in that it has means for measuring the original refractive index that occurs when transmitted light that passes through the fuel is emitted into the air from the opposite direction of the fuel. 2. A hollow transparent body filled with fuel, and a source t in this hollow transparent body.
A fuel property detector having means for emitting pIA, means for measuring the refractive index of the source transmitted through the hollow transparent body and refracted at the boundary between the WL surface of the fuel and the air, and t% mold. 3. A slit whose slit width changes along the longitudinal direction and a light amount detector that receives the light passing through the slit are provided, and changes in the refractive index of the transmitted light are converted into changes in the amount of light passing through the slit. 3. The fuel property detector according to claim 2, wherein the fuel property detector measures: 4. By providing a plurality of 7 photodetectors arranged at the position where the transmitted light hits and a selection circuit to which the output ends of these photodetectors are connected, and distinguishing between the photodetectors that have received the transmitted light, the transmitted light can be detected. Measuring the refractive index! ! The fuel property detector according to claim 2, which is defined as IIIk. 5. It has an optical fiber inserted into the fuel so as to maintain a predetermined attitude, and a means for inputting light into the optical fiber, and the light radiated into the fuel from the tip of the optical fiber 7 is connected to the fuel. A fuel property detector comprising means for measuring the refractive index of light emitted from a liquid surface. 6. A slit whose width changes along the longitudinal direction and a light amount detector that receives the light passing through the slit are provided, and changes in the refractive index of the transmitted light are converted into changes in the amount of light passing through the slit. 6. The fuel property detector according to claim 5, which measures: 7. A plurality of photodetectors are arranged at positions where the transmitted light hits, and a selection circuit into which the output ends of these photodetectors are fitted is provided to distinguish between the photodetectors that have received the transmitted light. 6. The fuel property detector according to item 5, which measures the refractive index of light to determine t-% mold. S. It has a means for irradiating the fuel liquid surface with parallel light beams and a means for receiving the irradiated scattered light in the fuel liquid in a predetermined range, and the irradiation is caused by a change in the amount of the received scattered light. A fuel property detector characterized by measuring the refractive index of light in the direction of the boundary between the fuel liquid level and the air. 9. The amount of light is detected at the bottom of the bottomed cylindrical body as a means of receiving scattered light! Claim 8, characterized in that the cylindrical body is provided with a cylindrical body whose opening is immersed in fuel in a predetermined posture, and which introduces the scattered light through the opening. Fuel property detector.