JPH08145966A - Fuel property discriminating apparatus - Google Patents

Abstract

PURPOSE: To reduce in size a measuring unit and to allow fuel to smoothly flow in the unit by providing an ultrasonic sensor in the cover of the unit, and by forming fuel flow pipelines in the cover part of the cover and the bottom of a tube with a bottom. CONSTITUTION: The structure of a measuring unit 15 has a tube 16 with a bottom in which a discharge pipeline 19 is formed at a bottom 16A, a cover 17 in which an input pipeline 18 is formed at the cover part 17A to cover the opening 16B of the tube 16, and an ultrasonic sensor 20 provided via a damper 25 and an annular resin layer 26 in the cover 17. The number of components is small. The structure is compact, mounting at a gasoline tube is enhanced, and the delay time τ by the sensor 20 can be accurately detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel property discriminating apparatus suitable for discriminating the property of fuel (gasoline) used in an automobile engine or the like from heavy oil or light oil.

[0002]

2. Description of the Related Art Generally, genuine gasoline used as fuel for automobile engines includes light gasoline mainly containing hydrocarbons such as heptane and pentane and heavy gasoline mainly containing hydrocarbons such as benzene. There is gasoline, and if further subdivided, there are three types: light gasoline, medium gasoline, and heavy gasoline.

Gasoline used for automobile engines is usually matched with light gasoline in ignition timing and the like. However, recently, due to the generalization of the use of heavy gasoline and the enforcement of the Air Pollution Law, the heavy gasoline is being used.

Therefore, matching light gasoline,
When heavy gasoline is used as fuel in an engine that is set to control ignition timing, the ignition timing is delayed compared to light gasoline, resulting in a tendency to become lean as a whole and startability at low temperatures. However, there is a problem that driving performance is deteriorated. Further, even when the vehicle is in a running state, when heavy gasoline is used, not only the driving performance is deteriorated such as a breathing phenomenon, but also inconvenient combustion causes a problem that harmful components in the exhaust gas are increased.

On the other hand, contrary to the above, when light gasoline is used in a gasoline vehicle that is set to match the heavy gasoline to control the ignition timing and the like, an overrich tendency occurs and the spark plug becomes There is a problem that "smoldering" occurs.

In order to solve the above-mentioned problems, an optical property determination device utilizing the refractive index or reflectance of light is widely known as a method for determining the property of fuel.

This optical property discriminating apparatus discriminates the property of fuel by the refractive index or reflectance of gasoline detected based on the intrinsic refractive index or reflectance stored in advance.

[0008]

By the way, the above-mentioned optical property determining apparatus according to the prior art has a problem that the number of parts is increased because a light source, a receiving apparatus or a reflecting apparatus is required.

Further, if the surface of the light source, the receiving device, the reflecting device, or the like is contaminated, the amount of light, the refractive index, or the reflectance changes to cause an error, which makes it impossible to accurately determine the property. .

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a fuel property discriminating apparatus capable of discriminating the fuel property with a simple structure.

[0011]

In order to solve the above-mentioned problems, a fuel property determination device adopted by the invention according to claim 1 is provided in the middle of a fuel supply pipe, and transmits a ultrasonic wave signal to receive a reflected wave. A measuring unit having an ultrasonic sensor for measuring the delay time up to, and a discrimination processing unit for discriminating the property of the fuel based on the delay time detected from the measuring unit. -Shaped tubular body, a lid provided so as to cover the opening of the bottomed tubular body, one fuel distribution pipe formed to project outward from the lid, and the one Another fuel distribution conduit that is formed to project outward from the bottom of the bottomed tubular body facing the fuel distribution conduit, and is provided on either the lid or the bottom, and the other bottom or It consists of an ultrasonic sensor that emits ultrasonic signals toward the lid. That.

According to a second aspect of the present invention, an ultrasonic sensor provided on the lid or the bottom is provided with an annular piezoelectric vibrator provided radially outside the fuel flow passage, and an axial direction of the piezoelectric vibrator. It is composed of a pair of annular electrodes provided on both side surfaces.

According to the third aspect of the invention, a sound absorbing material is provided between the ultrasonic sensor and the bottom of the lid or the bottomed tubular body.

According to a fourth aspect of the present invention, the discrimination processing section detects the density based on the delay time detected by the measuring section from the characteristic of the density with respect to the delay time of the ultrasonic sensor stored in advance. And a property determining unit that determines the property of the fuel based on the detected density of the density detecting unit.

[0015]

According to the present invention, the discrimination processing section calculates the density of the fuel flowing through the fuel supply pipe on the basis of the delay time detected by the ultrasonic sensor of the measuring section, and from this density, The property of the fuel is determined. At this time, in the measurement unit, fuel can be smoothly flowed from one fuel distribution pipe to another fuel distribution pipe, and the ultrasonic signal is propagated by increasing the length of the bottomed pipe. A long distance can be secured.

According to a second aspect of the present invention, the piezoelectric vibrator and each electrode forming the ultrasonic sensor are formed in an annular shape, and the piezoelectric vibrator and each electrode are provided radially outside of the fuel flow passage. Therefore, the ultrasonic sensor can be easily attached to the bottom portion or the lid of the bottomed cylindrical body.

According to the third aspect, since the sound absorbing material is provided between the ultrasonic sensor and the bottom of the lid or the bottomed tubular body on which the ultrasonic sensor is provided, external vibration (noise) is applied to the ultrasonic sensor. Can be prevented from being transmitted, and highly accurate delay time detection can be performed.

According to the present invention, the time required for the ultrasonic wave signal emitted from the ultrasonic wave sensor to travel back and forth in the fuel over a predetermined propagation distance varies depending on the property of the fuel. As a result, in the discrimination processing unit, the density is detected based on the delay time detected by the measuring unit from the characteristics of the density with respect to the delay time of the ultrasonic sensor stored in advance in the density detecting unit, and the property judging unit The property of the fuel can be determined based on the detected density detected by the density detecting means.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, the first embodiment of the present invention will be described with reference to FIGS.
An example of is shown.

In the figure, reference numeral 1 indicates, for example, a four-cylinder engine (only one cylinder is shown). The engine 1 is a cylinder 1A,
A cylinder head 1B mounted on the cylinder 1A,
The piston 1C is generally constituted by a piston 1C that reciprocates in the cylinder 1A. Reference numeral 2 denotes an ignition plug (only one is shown) provided on the cylinder head 1B located above each cylinder 1A. The ignition plug 2 is a cylinder when an ignition signal is output from a control unit 28 described later. It is designed to burn (explode) the air-fuel mixture in 1A.

A cylinder 1A of the cylinder 3 has a base end side serving as a branch pipe.
The intake manifold provided on the intake side of the cylinder head 1B is shown. An intake filter 4 is provided on the front end side of the intake manifold 3, and an air flow meter 5 for measuring the intake air amount and a throttle valve switch 6 are provided on the way. An attached throttle valve 7 etc. is provided,
Further, an injection valve 8 is provided near the cylinder head 1B, and the injection valve 8 injects gasoline G into the engine 1 in response to an injection signal from the control unit 28.

A gasoline tank 9 stores gasoline G therein, and an in-tank type gasoline pump 10 is provided in the gasoline tank 9. Reference numeral 11 denotes a gasoline pipe as a fuel supply pipe, one end of the gasoline pipe 11 is connected to a discharge side of the gasoline pump 10 via a gasoline filter 12, and the other end is connected to an injection valve 8 and an inflow side of the pressure regulator 13. The outlet side of the pressure regulator 13 is connected to the gasoline tank 9 via a return pipe 14.

Reference numeral 15 denotes a measuring portion of the fuel property discriminating apparatus according to the present embodiment, which is provided in the middle of the gasoline pipe 11, for example, and the measuring portion 15 has a bottomed tubular body 1 having a bottom portion 16A.
6, a shallow-bottom cylindrical lid 17 that covers the opening 16B of the bottomed tubular body 16, and a lid 17A located at the center of the lid 17A. An inflow conduit 18 that serves as one fuel distribution conduit, and another fuel distribution that is located at the center of the bottom portion 16A of the bottomed tubular body 16 facing the inflow conduit 18 and that projects outwardly. Outflow pipeline 19 that becomes a pipeline
And an ultrasonic sensor 20 which is provided on the lid 17 and transmits an ultrasonic signal toward the facing bottom portion 16A.

Here, the opening 16 of the bottomed tubular body 16
At B, an annular positioning portion 16C in which an O-ring 21 is fitted toward the inner diameter side is formed, and the opening 1 is formed.
A threaded portion 16D is formed on the outer peripheral surface of 6B. Further, a female screw portion 17C is formed on the inner peripheral surface of the lid 17 on the side of the opening 17B, and a signal line 22 is formed on the lid 17A.
An insertion hole 17D through which the is inserted.

Then, the female thread portion 17C of the lid body 17 is screwed into the male thread portion 16C of the bottomed tubular body 16 to cover the opening 16B of the bottomed tubular body 16 with the lid body 17. It is supposed to do. Therefore, the fuel continuously flows from the inflow conduit 18 on the lid 17 side toward the outflow conduit 19 on the bottom 16A side in the arrow F direction, and the measurement unit 15 is provided in the middle of the gasoline pipe 11. The fuel flows into the bottomed tubular body 16 through the inflow conduit 18 and
The fuel inside is directed from the outflow pipe 19 to the gasoline pipe 11,
It flows out smoothly.

On the other hand, the ultrasonic sensor 20 includes the lid 1.
7, an annular piezoelectric vibrator 23 provided on the outside in the radial direction of the inflow conduit 18, and a pair of annular electrodes 24, 24 provided on both axial side surfaces of the piezoelectric vibrator 23. The ultrasonic sensor 20 is a portion not covered by a damper material 25 described later (that is, the bottomed tubular body 16).
The side surface of the bottom portion 16A) is the ultrasonic wave emitting surface 20A.

Reference numeral 25 denotes a sound absorbing material (hereinafter referred to as “damper material 25”) provided between the ultrasonic sensor 20 and the lid 17 so as to surround the ultrasonic sensor 20. Is formed, for example, by filling cork, urethane, or the like. An annular damper portion 25A is formed between the outer circumference of the inflow conduit 18 and the inner circumference of the ultrasonic sensor 20 to insulate the inflow conduit 18 from the sound.

Further, reference numeral 26 is an annular resin layer which is resin-molded so as to surround the inflow conduit 18 and cover the ultrasonic wave emitting surface 20A of the ultrasonic sensor 20, and the annular resin layer 26 is formed of, for example, an epoxy resin. The ultrasonic sensor 20
The ultrasonic wave emitting surface 20A is protected and waterproofed. The ultrasonic sensor 20 is fixed to the lid 17 by the damper material 25 and the annular resin layer 26, and vibration from the outside is applied to the ultrasonic sensor 20 via the bottomed tubular body 16 and the lid 17. Are prevented.

The signal line 22 is inserted into the insertion hole 17D of the lid 17 and connected to each annular electrode 24. The signal line 22 is positioned and fixed to the lid body 17 by a seal washer 27.

On the other hand, the ultrasonic sensor 20 is a transmission / reception integrated type having a transmitter and a receiver, and the transmitter and the receiver are composed of a piezoelectric vibrator, a magnetostrictive vibrator, an electromagnetic induction vibrator or the like. There is. Then, by converting the electric energy into the vibration energy, whichever piezoelectric vibrator 23 that constitutes the ultrasonic sensor 20 is, the ultrasonic signal is transmitted from the ultrasonic wave emission surface 20A to the bottom portion 16A. , The reflected wave reflected by the bottom portion 16A is the ultrasonic sensor 2
The vibration energy is converted into electric energy by being received at zero. In the measuring unit 15 according to the embodiment, the distance between the ultrasonic sensor 20 and the bottom portion 16A facing the ultrasonic sensor 20 is the propagation distance D1, and the time from the ultrasonic signal oscillation to the reflected wave reception is delayed. It is designed to be detected as time τ.

In the measuring unit 15, the properties of gasoline, that is, the hydrocarbons (xylene,
The time it takes for the ultrasonic signal to pass differs depending on the component (hexane, etc.). FIG. 3 shows the characteristic of the density d with respect to the delay time τ.

Further, reference numeral 28 denotes a control unit which serves as a discrimination processing unit which constitutes the fuel property discrimination apparatus according to the present embodiment together with the measuring unit 15, and the control unit 2
8 is composed of, for example, a microcomputer,
The control unit 28 includes a storage circuit (not shown) including a RAM, a ROM, etc., and in addition to the property determination processing program shown in FIG. 4, an injection amount calculation program, an ignition timing control program (all not shown), etc. Is built in. Further, in the storage area 28A, the map shown in FIG. 3 and the determination reference density d1 for light gasoline and medium gasoline are given.
, Criterion density d2 for medium gasoline and heavy gasoline
Is remembered.

Here, in the characteristic map shown in FIG. 3, for gasoline of known properties, the horizontal axis represents the delay time τ for the ultrasonic signal to travel back and forth through the propagation distance D1 in gasoline, and the vertical axis represents the density. d [kg / m ³ ], and the delay time τ is appropriately set according to the distance dimension of the propagation distance D 1.

The fuel property determining apparatus according to the present embodiment is constructed as described above. Next, the property determining process will be described with reference to the program shown in FIG.

First, in step 1, the delay time τ is read from the ultrasonic sensor 20 of the measuring section 15, and in step 2,
The density d (eg, density da) corresponding to the detected delay time τ is calculated with reference to the map of FIG. Then, in step 3, the property is discriminated based on the detected density db. That is, density d <d1, d1 ≤ density d≤d
2. Discrimination in three ranges of density d> d2 (note that
The unit of the density d is kg / m ^3. )

If the density d <d1 in step 3, the process moves to step 4, the measured fuel is determined to be light gasoline, and in step 5, it is stored in the storage area 28A that the fuel is light gasoline. Then, the process returns in step 10.

When d1 ≤ density d ≤ d2 in step 3, the process moves to step 6 and the measured fuel is determined to be medium gasoline, and in step 7 it is determined that the fuel is medium gasoline. Store in storage area 28A, step 1
Return with 0.

Further, if the density becomes d> d2 in step 3, the process moves to step 8, the measured fuel is determined to be heavy gasoline, and in step 9, it is stored in the memory area that the fuel is heavy gasoline. 28A and returns in step 10.

As described above, in the fuel property discriminating apparatus according to the present embodiment, the property of the fuel is judged to be light, medium or heavy based on the detected density d. Therefore, the property of the fuel is discriminated finely. Therefore, engine control such as fuel injection amount and ignition timing control can be accurately performed.

Further, in the measuring unit 15 according to this embodiment, the ultrasonic sensor 20 is provided on the lid 17 having the inflow conduit 18.
Since the outflow conduit 19 is provided in the bottom portion 16A of the bottomed tubular body 16, the number of components of the measuring unit 15 can be reduced and the measuring unit 15 can be made compact with a simple structure. When connecting the measuring unit 15 in the middle of the gasoline pipe 11, the space for mounting the measuring unit 15 is not required, and the space can be effectively used and the mountability can be improved.

Further, by connecting the inflow pipe 18 to the inflow side of the gasoline pipe 11 and the outflow pipe 19 to the outflow side of the gasoline pipe 11, respectively, fuel is supplied through the inflow pipe 18 and the outflow pipe 19. The smooth flow can be made straight to the bottom tube body 16, and the delay time τ by the ultrasonic sensor 20 can be increased.
The detection sensitivity of can be improved.

On the other hand, in the measuring section 15 of this embodiment,
Since the bottomed tubular body 16 is attachable to and detachable from the lid body 17 by screwing, the bottomed tubular body 16 can be easily replaced, and by increasing the length of the bottomed tubular body 16, The propagation distance D1 can be easily lengthened and the ultrasonic sensor 20
The detection sensitivity of the delay time τ due to can be increased.

Further, since the damper material 25 is provided between the ultrasonic sensor 20 and the lid 17 on which the ultrasonic sensor 20 is provided, vibration from the outside is applied to the ultrasonic sensor 20 with a bottomed tube. It is possible to prevent the transmission via the body 16 and the lid 17, and it is possible to detect the delay time with high accuracy.

On the other hand, in this embodiment, since the density d is detected by utilizing the ultrasonic wave, unlike the prior art, the defect due to deterioration with time does not occur like the optical property determination device of the optical type, and the high accuracy is obtained. Enables detection.

In the first embodiment, steps 1 and 2 are specific examples of density detecting means, and steps 3 to
Reference numeral 9 is a specific example of the property determining means.

Next, FIG. 5 shows a second embodiment according to the present invention. The feature of this embodiment is that the ultrasonic sensor 20 provided in the measuring section 31 is provided on the bottom 16A side of the bottomed tubular body 16. This is because the ultrasonic sensor 20 detects the delay time τ by reflecting the ultrasonic signal transmitted by the cover 17A of the cover 17. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The measuring unit 3 of this embodiment having the above-mentioned configuration
Also in No. 1, it is possible to obtain the same effects as those of the first embodiment described above, it is possible to distinguish the properties of the fuel from light, medium, and heavy based on the density d, and the engine such as fuel injection amount, ignition timing control, etc. Control can be performed accurately.

Next, FIG. 6 shows a third embodiment according to the present invention. The feature of this embodiment is that the bottomed tubular body in the measuring section is a tubular body, and the bottom of the tubular body is the bottom. The lid is screwed together. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, 41 is a measuring portion of the fuel property determining apparatus according to this embodiment, 42 is a bottomed tubular body of the measuring portion 41, and the bottomed tubular body 42 is an outer peripheral surface of both side openings. A cylindrical body 43 formed with male screw portions 43A and 43B, and a female screw portion 44 screwed to one male screw portion 43B of the cylindrical body 43.
And a bottom cover body 44 having a shallow bottom and forming a bottom portion of the bottomed tubular body 42.

Reference numeral 45 denotes an outflow conduit, which is formed from the central portion of the bottom portion 44B of the bottom cover 44 toward the outside.

The measuring unit 4 of this embodiment having the above-mentioned configuration
Also in No. 1, it is possible to obtain the same effects as those of the first embodiment described above, it is possible to distinguish the properties of the fuel from light, medium, and heavy based on the density d, and the engine such as fuel injection amount, ignition timing control, etc. Control can be performed accurately. Furthermore, since the bottom cover 44 is also removable, the maintainability of the measuring unit 41 can be improved.

In each of the above-described embodiments, the fuel property is described as being divided into three types, light, medium and heavy. However, the present invention is not limited to this, and it is possible to distinguish light and heavy. You may distinguish according to a kind.

Further, in each of the above-described embodiments, the inflow conduit 18 is located at the center of the lid 17A, and the outflow conduit 19 (45) is provided.
Was formed at the center of the bottom portion 16A (44B), but the present invention is not limited to this position and may be arranged so as to face each other at a position eccentric from the center of the shaft.

[0055]

As described in detail above, in the fuel property discriminating apparatus according to the invention of claim 1, in the discrimination processing section, the fuel flowing through the fuel supply pipe is based on the delay time detected by the ultrasonic sensor of the measuring section. Is calculated, and the property of the fuel is discriminated from this density. At this time, it is possible to smoothly flow the fuel from the fuel supply pipe from one fuel distribution pipe to the other fuel distribution pipe, and by increasing the length of the bottomed pipe, the ultrasonic signal A long propagation distance can be secured, the delay time by the ultrasonic sensor can be detected with high accuracy, and accurate property determination can be performed.

According to the second aspect of the present invention, since the piezoelectric vibrator and the electrodes that form the ultrasonic sensor are annular electrodes, the piezoelectric vibrator and the annular electrodes are provided outside the fuel distribution pipe in the radial direction. Therefore, the measuring unit can be downsized. Also, when mounting the measurement unit to the fuel supply pipe,
By reducing the size of the measuring unit, the mounting space can be reduced and the mountability can be improved.

According to the third aspect of the present invention, since the sound absorbing material is provided between the ultrasonic sensor and the lid or the bottom portion thereof, it is possible to prevent external vibration (noise) from being transmitted to the ultrasonic sensor. It is possible to prevent the detection sensitivity of the sensor from deteriorating and to detect the delay time with high accuracy.

According to the fourth aspect of the present invention, by configuring the discrimination processing section, based on the delay time detected by the measuring section from the characteristic map of the density with respect to the delay time by the ultrasonic sensor stored in advance by the density detecting means. To detect the density. Then, the property determining unit can determine whether the property of the fuel is light oil, heavy oil or medium oil based on the density detected by the density detecting unit. As a result, it is possible to always accurately determine the fuel property regardless of the fuel temperature.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a fuel injection control device using a fuel property determination device according to a first embodiment.

FIG. 2 is a vertical cross-sectional view showing a measuring unit of the fuel property discriminating apparatus according to the first embodiment.

FIG. 3 is a characteristic line map showing the density d with respect to the delay time τ in known gasoline by the measuring unit according to the first embodiment.

FIG. 4 is a flowchart showing a fuel property determination process according to the first embodiment.

FIG. 5 is a vertical cross-sectional view showing a measurement unit of a fuel property determination device according to a second embodiment.

FIG. 6 is a vertical cross-sectional view showing a measuring section of a fuel property discriminating apparatus according to a third embodiment.

[Explanation of symbols]

 11 Gasoline piping (fuel supply piping) 15,31,41 Measuring part 16,42 Bottomed tubular body 16A, 44B Bottom 17 Lid 17A Lid 18 Inflow pipeline (one fuel flow port) 19, Outflow pipeline ( Other fuel flow ports) 20 Ultrasonic sensor 23 Piezoelectric vibrator 24 Ring electrode 25 Damper material (sound absorbing material) 26 Ring resin layer 28 Control unit (discrimination processing part) 43 Cylindrical body 44 Bottom lid τ Delay time d Density

Claims (4)

[Claims] 1. A measuring unit which is provided in the middle of a fuel supply pipe and has an ultrasonic sensor for measuring a delay time from transmission of an ultrasonic signal to reception of a reflected wave, and an ultrasonic sensor of the measuring unit. A determination processing unit that determines the property of the fuel from the calculated density by calculating the density of the fuel flowing through the fuel supply pipe based on the delay time, and the measurement unit has a bottomed tubular body. A lid provided so as to cover the opening of the bottomed tubular body, one fuel distribution pipe formed to project outward from the lid, and the one fuel distribution pipe Another fuel distribution pipe that is formed to project outward from the bottom of the bottomed tubular body facing the passage, and is provided on either the lid or the bottom, and an ultrasonic signal is provided toward the other. A fuel property determination device including an ultrasonic sensor for transmitting the fuel. 2. The ultrasonic sensor provided on the lid or the bottom is provided with an annular piezoelectric vibrator provided on the outer side in the radial direction of the fuel flow passage, and on both axial side surfaces of the piezoelectric vibrator. The fuel property determination device according to claim 1, wherein the fuel property determination device comprises a pair of annular electrodes. 3. The fuel property determining device according to claim 1, wherein a sound absorbing material is provided between the ultrasonic sensor and the bottom of the lid or the bottomed tubular body. 4. The density detecting means, wherein the discrimination processing part detects a density based on a delay time detected by the measuring part from a characteristic of a density of the ultrasonic sensor with respect to a delay time stored in advance, and the density detecting means. 2. The fuel property discriminating device according to claim 1, further comprising a property discriminating unit for discriminating the property of the fuel based on the detection density of the detecting unit.