JP2000313240A - Residual quantity detection device for liquid tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a residual quantity detection device for obtaining the correct height of a liquid level, even in the cases of a tilted liquid tank, and detecting the height of a liquid level in a position at a distance shorter than that to nearby the center in the tank from the side surface of the tank. SOLUTION: A sensor main body 21 is arranged on a side surface 11 so that the center of a supporting shaft can be positioned at a position having a height Hsi from a bottom surface 13, or at a position having a distance WS from the surface 11; and detects the rotation angle θi of an arm 22 rotating in accordance with the floating height of a float 23. The arm length As of the arm 22 is set shorter than a width WT/2, and the height of a liquid level detected by a float type level sensor 20 can be corrected based on the slant angle θT of the tilted tank 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the remaining amount of a liquid tank, and more particularly, to detecting the height of the liquid level in a liquid tank mounted on a vehicle, and based on the detection result. The present invention relates to a remaining amount detection device for a liquid tank that calculates the remaining amount of liquid.

[0002]

2. Description of the Related Art A vehicle such as a construction machine is provided with a remaining amount detecting device for detecting a remaining amount of fuel in a fuel tank mounted on the vehicle.

[0003] The remaining amount detection device is provided with a level sensor for detecting the level of the liquid level of the fuel. Examples of the level sensor include an ultrasonic sensor and a float type level sensor.

FIG. 8A is a schematic side view of a fuel tank provided with a remaining amount detecting device using an ultrasonic sensor. The remaining amount detecting device is provided with an ultrasonic sensor 2 disposed at the center in the width direction of the upper surface 1A of the fuel tank 1 to detect the liquid level 1
The distance h between C and the sensor unit is detected, and the control unit 3
Based on the distance h detected by the ultrasonic sensor 2 and the preset height H0 from the bottom surface 1B of the fuel tank 1 to the sensor section, the fuel level H is determined. The remaining fuel amount is calculated by calculating the product of the height H and the bottom area of the fuel tank 1.

[0005] Further, since the ultrasonic sensor 2 is provided at the center of the upper surface 1A in the width direction, the fuel tank 1 is arranged as shown in FIG.
Even when the ultrasonic sensor 2 is inclined with the inclination angle θ as shown in FIG. 8B, the ultrasonic sensor 2 has the same height as the liquid level when the fuel tank 1 is horizontal (dotted line in FIG. 8B). This means that the height position is being measured.

As described above, in the remaining amount detection device using the ultrasonic sensor, even if the fuel tank 1, that is, the liquid level 1C is inclined,
An accurate liquid level is obtained.

FIG. 9 is a schematic side view of a fuel tank provided with a remaining amount detecting device using a float type level sensor.
In this remaining amount detecting device, the side surface 4A of the fuel tank 4
A float type level sensor 5 is disposed on the side surface 4 of the float type level sensor 5. A support portion 5C rotatably supporting an arm 5B provided with a float 5A is provided on the side surface 4.
A is attached.

In this case, the float 5A is provided on the upper surface 4C (or the bottom surface) of the fuel tank 4 so that an accurate liquid level can be obtained even when the fuel tank 4, that is, the liquid surface 4B is inclined with the inclination angle θ. It is provided so as to be located at the center in the width direction. The remaining level of the fuel is detected by such a float type level sensor 5 based on the height of the float 5A floating according to the height of the fuel level 4B.

[0009]

However, in the above-mentioned conventional remaining amount detecting device, in the remaining amount detecting device using an ultrasonic sensor, as shown in FIG. Even when the surface 1C is inclined, the liquid level can be accurately detected, but the ultrasonic sensor 2 is expensive, and as a result, the remaining amount detection device itself becomes expensive. There is.

In the remaining amount detecting device using the float type level sensor, the following problem occurs when the height of the fuel tank 4 is high.

That is, as shown in FIG. 10, the liquid level of the fuel in the fuel tank 6 having the height "H0", the width "W", and the "height H0 / 2> width W" is formed. When the height is detected using the float type level sensor 7, the side surface 6
A float type level sensor 7 is disposed at a height of H0 / 2 from the bottom surface 6B in FIG. A, and the arm 7B rotatably supported by the support 7C is moved from the support position of the support 7C to the float 7A. Up to the tip of "H0 /
2 ".

For this reason, in the vicinity of a position substantially at the height of "H0 / 2" from the bottom surface 4B, the float 7A collides with the side surface 6C as shown in FIG. As a result, the heights of all the liquid levels in the fuel tank 6 cannot be detected.

Here, in order to be able to detect the heights of all the liquid levels in the fuel tank 6, the arm 7B is provided with a support 7C.
Is formed with a length of approximately W or less from the supporting position of the float 7A to the tip of the float 7A, and the float 7A, ie, the arm 7B
Assume a semicircular motion as indicated by a dotted line indicated by a symbol R in FIG.

In this case, since the arm 7B is longer than the arm 5B shown in FIG. 9, the moment naturally increases. For this reason, the supporting portion 7 for rotatably supporting the arm 7B is provided.
A large load is applied to C, which causes deterioration of the support portion 7C in a short period of time.

Therefore, an object of the present invention is to detect the height of the liquid surface at a position where the liquid tank is inclined and shorter than the distance from the side surface of the liquid tank to the vicinity of the center of the liquid tank. It is an object of the present invention to provide an apparatus for detecting the remaining amount of a liquid tank that can obtain an accurate liquid level.

[0016]

In order to achieve the above object, according to a first aspect of the present invention, a liquid level of a liquid in a liquid tank mounted on a vehicle is detected, and the detection is performed. In the liquid tank remaining amount detection device for obtaining the remaining amount of the liquid based on the result, the liquid level height at a position shorter than the distance from the side surface of the liquid tank to the vicinity of the center in the liquid tank is detected. Detecting means, an inclination angle detecting means for detecting an inclination angle of the liquid tank inclined, and correcting the height of the liquid level detected by the detecting means based on the inclination angle detected by the inclination angle detecting means. And a calculating means for calculating the remaining amount of the liquid based on the data indicating the liquid level height corrected by the correcting means.

The first invention will be described with reference to FIGS.

The sensor body 21 is positioned such that the center of the axis for supporting the arm 22 is located at a height Hsi from the bottom surface 13 in the liquid tank 10 and the distance (interval) from the side surface 11.
It is arranged on the side surface 11 such that the center of the shaft supporting the arm 22 is located at a position after WS.

The sensor body 21 is composed of, for example, a potentiometer, and the arm 2 which rotates according to the floating height of the float 23 (ie, the height of the liquid surface 12).
2 is detected. In this embodiment, the sensor body 21 outputs a signal corresponding to the rotation angle of the arm 22.

The length (distance) As between the center of the shaft provided on the sensor body 21 and the center of the float 23 is represented by
The arm length of the arm 22 is used.

When the liquid tank 10 is inclined with the inclination angle θT, the height of the liquid level 12 detected by the float type level sensor 20 is corrected based on the inclination angle θT. That is, the height of the liquid surface 12 when the liquid tank 10 is inclined is corrected to the height of the liquid surface 12A when the liquid tank 10 is in the horizontal state.

According to the first aspect of the present invention, when the height of the liquid surface is detected at a position where the liquid tank is inclined and the distance from the side surface of the liquid tank to the vicinity of the center of the liquid tank is shorter than the distance. Even so, the detected liquid level height can be corrected to the liquid level height when the liquid tank is horizontal based on the inclination angle of the liquid tank.

In a second aspect based on the first aspect, the detecting means includes a level sensor for detecting a height of the liquid level based on information indicating a position of a float floating on the liquid level in the liquid tank. It is characterized by:

In a third aspect based on the second aspect, in the level sensor, the other end of the arm having at one end a float floating on the liquid surface in the liquid tank is rotatably supported on a side surface of the liquid tank. The rotation angle of the arm when the arm is rotated by the float floating according to the height of the liquid surface, and the height from the bottom surface of the liquid tank to a position where the arm is rotatably supported. , The height of the liquid level is detected based on

According to the third aspect, similarly to the first aspect, the liquid tank is inclined and the distance from the side surface of the liquid tank to the vicinity of the center in the liquid tank is reduced by using an inexpensive level sensor. Even when detecting the height of the liquid level at a position at a short distance, this detected liquid level height is
The height of the liquid level when the liquid tank is horizontal can be corrected based on the inclination angle of the liquid tank.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the detecting means is configured such that the other end of the arm having a float floating on the liquid surface in the liquid tank is rotatably supported on a side surface of the liquid tank. The rotation angle of the arm when the arm is rotated by the float floating according to the height of the liquid surface, and the height from the bottom surface of the liquid tank to a position where the arm is rotatably supported. Is a level sensor for detecting the height of the liquid surface based on the height of the liquid tank, wherein the height from a position near the bottom surface of the liquid tank to a position near the top surface of the liquid tank is divided into N (N is a positive integer). N level sensors each having a range corresponding to each height as a detection range of the level of the liquid surface, wherein the correction means comprises a float floating on the liquid surface among the N level sensors. Detected by a level sensor with The the liquid surface height, is characterized in that it comprises means, for correcting on the basis of the inclination angle detected by the inclination angle detecting means.

The fourth invention will be described with reference to FIGS.

A plurality of float type level sensors 31 to 33
Is the liquid tank 10 using each level sensor.
Is disposed on the side surface 11 so that the height of the liquid corresponding to the height H0 of the liquid can be detected. For example, the float type level sensors 31 to 33 are arranged at positions Hs1, Hs2, and Hs3 from the bottom surface 13, respectively.

That is, the level sensors 31 to 33 are arranged so that the detection range of the liquid level by each level sensor overlaps with the detection range of the adjacent level sensor. (In the direction of the arrow).

In this case, in each of the adjacent level sensors, even if the depression angle is detected by the upper level sensor and the elevation angle is detected by the lower float sensor, Each float floats on the liquid surface without collision.

When the liquid tank 10 is inclined at an inclination angle θT, the float type level sensor 31 to 33 has a float floating on the liquid surface based on the inclination angle θT. The liquid level detected by the float type level sensor is corrected. That is, the height of the liquid surface 12 when the liquid tank 10 is inclined is corrected to the height of the liquid surface 12A when the liquid tank 10 is in the horizontal state.

According to the fourth aspect of the invention, even when the height of the liquid tank is high and the liquid tank is inclined, the plurality of inexpensive level sensors are used to move the side of the liquid tank into the liquid tank. The height of the liquid level at a position shorter than the distance to the vicinity of the center can be detected, and the detected liquid level is horizontal based on the inclination angle of the liquid tank. It can be corrected to the liquid level in the case.

In a fifth aspect based on the first or fourth aspect, the calculating means includes data indicating the corrected liquid level height corrected by the correcting means and a preset value of the liquid tank. Find the product with the data indicating the bottom area,
It is characterized in that the remaining amount of the liquid in the liquid tank is calculated.

In a sixth aspect based on the first or fourth aspect, the variation in the detected value of the liquid level detected by the detecting means is within a preset allowable range, and the state is determined in advance. If it has been running for more than the set time,
It is characterized by further comprising control means for causing the correction means to correct the liquid level and for causing the calculation means to calculate the remaining amount of liquid.

According to the sixth aspect, it is possible to prevent erroneous detection of the detecting means due to vibration of the vehicle body, that is, the liquid tank, and fluctuation of the liquid. That is, based on the height of the liquid surface detected when the liquid surface is stationary (or in a state where the liquid surface can be regarded as stationary), accurate liquid level correction and the remaining amount of liquid are performed. Can be requested.

In a seventh aspect based on the first aspect, the fourth aspect or the sixth aspect, when the tilt angle detected by the tilt angle detecting means is a value within a predetermined allowable range, the correction means To correct the liquid level,
The apparatus further comprises means for causing the calculating means to calculate the remaining amount of the liquid.

According to the seventh aspect, it is possible to prevent the detection of the liquid level when the vehicle body, that is, the liquid tank is extremely inclined.

[0038]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a device for detecting a remaining amount of a liquid tank according to the present invention.

FIG. 1 is a principle diagram showing the principle of a device for detecting the remaining amount of a liquid tank.

This principle diagram shows a state in which a liquid tank 10 such as a fuel tank mounted on a vehicle such as a construction machine is viewed from the front of the vehicle body. The vehicle body, that is, the liquid tank 10 is inclined from a reference line GL parallel to the horizontal line. FIG. 3 shows a side view of the liquid tank 10 in a state where the liquid tank 10 is inclined rightward with an angle θT.

In this embodiment, the liquid tank 1
When 0 is inclined rightward with respect to the reference line GL, the inclination angle θ
T <0, that is, (−θT). On the other hand, when tilted to the left, the tilt angle θT> 0, that is, (+ θT).

The width inside the liquid tank 10 is "WT",
The depth is "T" and the height is "H0".

On the side surface 11 inside the liquid tank 10,
A float type level sensor (hereinafter, referred to as a level sensor) 20 for detecting the height of the liquid level 12 of the liquid fuel (hereinafter, referred to as fuel) is provided.

The level sensor 20 includes a sensor main body 21 provided on the side surface 11, an arm 22 rotatably supported by the sensor main body 21, and a float 23 provided at a tip end of the arm 22. I have.

The float 23 has, for example, a cylindrical shape (or a spherical shape).
(The center of the float 23) is set so as to float in conformity with the liquid level 12.

The sensor body 21 is positioned such that the center of the axis supporting the arm 22 is located at a height Hsi from the bottom surface 13 in the liquid tank 10, and the distance (interval) from the side surface 11.
It is arranged on the side surface 11 such that the center of the shaft supporting the arm 22 is located at a position after WS.

The sensor main body 21 is composed of, for example, a potentiometer, and the arm 2 that rotates according to the floating height of the float 23 (that is, the height of the liquid surface 12).
2 is detected. In this embodiment, the sensor body 21 outputs a signal corresponding to the rotation angle of the arm 22.

For convenience of explanation, the sensor body 2
The length (distance) As between the center of the shaft provided in 1 and the center of the float 23 is defined as the arm length of the arm 22.

The arm length As is set to be shorter than the center of the liquid tank 10 in the width direction, that is, WT / 2 (for example, や or の of the width WT).

Here, for example, when the level sensor 20 is arranged such that the center of the float 23 is located near the center of the liquid tank 10 (see the conventional example shown in FIG. 9), the liquid tank is inclined. Even in this case, the height of the liquid level 12 on which the float 23 is floating and the actual liquid level 1
The height “H” of 2A (the height of the liquid level when the liquid tank is in a horizontal state) roughly matches.

However, as in the present embodiment, the level sensor 20 is arranged such that the center of the float 23 has a width WT from the side surface 11.
For example, in a state where the liquid tank 10 is inclined in a state where the liquid tank 10 is inclined at a distance passing through 1/3 or 1/4, the height of the liquid surface 12 on which the float 23 is floating,
The actual height "H" of the liquid surface 12A differs.

Therefore, in the present invention, the arm length As
<WT / 2 (for example, arm length As = for example, 1/3 or 1/4 of width WT) is established, and even when the liquid tank 10 is inclined, the accurate liquid level height can be adjusted. As can be determined, the inclination angle θT of the inclination of the liquid tank 10
Is measured by an inclinometer (not shown), and the height of the liquid level detected by the level sensor 20 is corrected based on the inclination angle θT.

Next, correction of the liquid level detected by the level sensor 20 will be described with reference to FIG.

FIG. 2 is a principle diagram in which the state shown in FIG. 1 is rewritten for easy explanation. Of course, various parameters are the same as those shown in FIG.

As shown in FIG. 2, when the liquid tank 10 is in the horizontal state, the intersection between the liquid surface 12A and the side surface 11 is "B", the intersection between the liquid surface 12A and the side surface 14 is "D", In a state where the tank 10 is inclined rightward with the inclination angle θT, the intersection between the liquid surface 12 and the side surface 11 is “C”, the intersection between the liquid surface 12 and the side surface 14 is “E”, and the center of the float 23 is “ a ", the intersection between the side surface 11 and a line segment passing through the center a and parallel to the horizontal line is" b ", and the intersection between the liquid level 12 and the center of the width WT (width WT / 2) is" A ". .

Further, a line segment AB = WT / 2 = X1, a line segment a
b = XFi = X2, line segment BC = Y1, and line segment bC = Y2
And

As can be seen from FIG. 2, the line segment of the X direction component of the arm 22 rotated by the rotation angle θi is parallel to the horizontal line, and the line segment of the Y direction component of the arm 22 is perpendicular to the vertical line. Are parallel, the triangle △ ABC and the triangle △ abC have a similar relationship.

Under the conditions described above, the side surface 11
The distance (length) XFi from to the center a of the float 23 is represented by the following equation (1).

XFi = AS * Cos θi + WS (1) The height YFi from the bottom surface 13 to the center a of the float 23
Is represented by equation (2).

YFi = AS * Sin θi + Hsi (2) By the way, as can be seen from FIG. 2, since the point A is at the center of the width WT (width WT / 2), the area of the triangle △ ABC and the area of the triangle ADE Are equal, and therefore, the liquid surface height H can be expressed by equation (3).

H = YFi-h (3) where H is the exact height of the liquid surface (the height of the liquid surface 12A when the liquid tank 10 is horizontal), and YFi is the level sensor 2
The height of the liquid level based on the detection result of 0 and h are correction amounts.

As can be seen from FIG. 2, h is “line segment B
C−line segment bC ”, the correction amount h
Is represented by equation (4).

H = Y1-Y2 (4) As described above, since the triangle △ ABC and the triangle △ abC have a similar relationship, Tan θT is determined based on the inclination angle θT of the liquid tank.
Is obtained, TanθT is expressed by equation (5).

TanθT = Y1 / X1 = Y2 / X2 (5) From this equation (5), Y2 and Y1 are expressed by equations (6) and (7).
It is expressed by an equation.

Y1 = TanθT * X1 (6) Y2 = TanθT * X2 (7) When the equations (6) and (7) are substituted into the equation (4), the correction amount h is expressed by the equation (8). You.

H = TanθT * X1−TanθT * X2 = TanθT (X1−X2) (8) Here, since X1 = WT / 2 and X2 = XFi, Expression (8) is expressed by Expression (9). You.

H = Tan θT {(WT / 2) −XFi} (9) When the equation (1) is substituted into the equation (9), the correction amount h is finally expressed by the equation (10).

H = Tan θT {(WT / 2) − (AS * Cos θi + WS)} (10) Accordingly, the remaining amount V of the fuel can be expressed by equation (11).

The remaining fuel amount V = WT * T * H = WT * T * {(AS * Sin θi + Hsi) −h} (11) Next, in the liquid tank 10 based on the above-described principle,
With reference to FIG. 3, a description will be given of a mounting state of the sensors when a plurality of float type level sensors and an inclination angle sensor are arranged.

FIG. 3 is a diagram for explaining the mounting state of the sensors when a plurality of float type level sensors and tilt angle sensors are arranged in the liquid tank 10.

As described with reference to FIG. 1, the inside of the liquid tank 10 is also formed to have a width "WT", a depth "T", and a height "H0". The depth T is set to a length such that the liquid surface is maintained substantially horizontal even when the liquid tank 10 is inclined in the x-axis direction.

The liquid tank 10 includes a plurality of float type level sensors (hereinafter, referred to as level sensors) 31 and 3 having the same function and structure as the level sensor 20 described above.
2, 33 and an inclinometer 40 for detecting an inclination angle when the liquid tank 10 is inclined are arranged.

The length (height) of the column in each float of the level sensors 31, 32, 33 is set shorter than the length obtained by dividing the depth T into three equal parts.

The level sensor 3 provided on the bottom surface 13 side
1, and the level sensor 33 provided on the upper surface 15 side,
As shown in FIG. 3, it is a region formed by the length T2 of the side surface 11 and the height H0, and is located at the heights Hs1 and Hs3 from the bottom surface 13.

The level sensor 31 and the level sensor 33
As shown in FIG. 3, the level sensor 32 is located between the bottom surface 13 and the height Hs2 in a region formed by the length T1 of the side surface 11 and the height H0.

In short, the adjacent level sensors move in the y direction (depth direction) on the side surface 11 of the liquid tank 10 so that the floats do not collide with each other when the arm makes a semicircular movement around the axis of the sensor body. Area.

The inclinometer 40 is a tilt angle sensor, for example, a contact type or a non-contact type (optical type, magnetoresistive element type)
Is formed by a length T3 of the side surface 11 and a height H0.
Is disposed at a position below the outer side surface 11.

Next, the definition of the sensing values of the rotation angle θi and the inclination angle θT will be described with reference to FIG.

FIG. 4 is a diagram for explaining the definitions of the sensing values of the rotation angle θi and the inclination angle θT, and is a side view showing the liquid tank 10 shown in FIG. 3 as viewed from the front of the vehicle body.

The plurality of level sensors 31 to 33 use the respective level sensors to determine the height H 0 of the liquid tank 10.
To be able to detect the height of the liquid corresponding to
It is arranged on the side surface 11. That is, as described with reference to FIG. 3, the level sensors 31 to 33 are respectively located at the heights Hs1, Hs2, and Hs3 from the bottom surface 13.

In short, the level sensors 31 to 33 are arranged such that the liquid level detection range of each level sensor overlaps the detection range of the adjacent level sensor in the z direction (height) of the side surface 11 of the liquid tank 10. Direction).

In this case, in each of the adjacent level sensors, even if the depression angle is detected by the upper level sensor and the elevation angle is detected by the lower float sensor, Each float floats on the liquid surface without collision.

The level sensors 31 to 31 arranged as described above
The elevation angle or depression angle of each arm of 33 is θ1, θ2, θ, respectively.
A sign of “+” is added for an elevation angle, and a sign of “−” is added for a depression angle. When the liquid tank 10 tilts to the right with respect to the reference line GL parallel to the horizontal line, the tilt angle is (−θT), and when the liquid tank 10 tilts to the left, the tilt angle is (+ θT).

Here, the prerequisites for detecting the liquid level in the liquid tank 10 having the above-described configuration will be described with reference to FIGS.

(1) Each level sensor 31, 32, 33
Are arranged so that the detection ranges of the liquid level by the respective level sensors overlap.

(2) Since the liquid tank 10 has a thin structure in the front and rear direction (length in the X direction), the inclination around the x axis is ignored.

(3) When the liquid surface exists in the overlapping portion, the detection result of the level sensor located on the upper side is used.

(4) In order to prevent erroneous detection of the level sensor due to the vibration of the vehicle body and the fluctuation of the liquid level, the fluctuation of the rotation angle of the arm of the level sensor is set to a predetermined allowable range (for example, “± 10 degrees”). Only when the state is maintained for 10 seconds or more. In this case, the liquid level is treated as being stationary in the calculation of the liquid level height correction and the like.

(5) If the inclination angle θT deviates from a value within a preset allowable range (for example, −15 degrees ≦ θT ≦ + 15 degrees), no sensing is performed.

Next, a control system configuration for executing various arithmetic processing based on the liquid level detected by the remaining amount detecting device of the liquid tank 10 will be described with reference to FIG.

As shown, the control system includes the above-described level sensors 31, 32, 33, an inclinometer (inclination angle sensor) 40, an engine rotation sensor 50, and a controller 60.

In FIG. 5, the parts performing the same functions as those of the components shown in FIG. 3 are denoted by the same reference numerals.

A signal indicating the tilt angle θi detected by each of the level sensors 31, 32, 33 and a signal indicating the tilt angle θT detected by the inclinometer 40 are transmitted to the controller 60.
Is input to

The engine rotation sensor 50 detects the number of rotations of the engine mounted on the vehicle, and outputs the result to the controller 60.

The controller 60 includes an input / output (I / O) unit 61, a memory 62, a central processing unit (hereinafter, referred to as a CPU) 63, and an interface 64.

The input / output unit 61 includes the level sensors 31, 3
Data indicating the tilt angle θi from the second and the third 33 and the inclinometer 40
The data indicating the tilt angle θT detected by the CPU is input, and these data are stored in the memory 62 and the CPU 6
In accordance with the instruction of No. 3, a signal for controlling each of these sensors is output.

The memory 62 stores the above-mentioned equations (10) and (1).
Of the parameters of 1, the float arm length AS (3
Arm lengths for the three level sensors are the same), the mounting height WS from the side surface 11 of the liquid tank 10 to the axis of the sensor body (the mounting height for the three level sensors is the same), and the height from the bottom surface 13 of the liquid tank 10 Level sensor mounting height Hsi (mounting heights Hs1, Hs2, Hs3 corresponding to each of the three level sensors), width W of liquid tank 10
Data indicating T and depth T is stored in advance.

The memory 62 stores the known parameter data, the sampled rotation angle θi and the tilt angle θT.
Are allocated, a work area for executing the processing for calculating the liquid level height correction amount h, the liquid level height H and the remaining fuel amount V, and other necessary processing is allocated.

The CPU 63 reads and writes data from and to the memory 62 to calculate the corrected liquid level by calculating the above-mentioned equations (10) and (3), and to calculate the remaining fuel amount by calculating the above-described equation (11). Obtain the fuel consumption rate.

[0100] The interface 64 transfers data such as a calculation result by the CPU 63 to a data processing device such as a personal computer 70 in accordance with an instruction from the CPU 63. PC 7
0 executes a predetermined process based on the transferred data.

Note that the controller 60 is provided with a fuel remaining amount counter and a fuel consumption calculation counter (not shown), and the count values of these counters are counted up based on a predetermined calculation result by the CPU 63.

The controller 60 monitors whether the preconditions (3) to (5) are satisfied, and performs sensing control.

Next, this control will be described.

[Control Based on Precondition (3)] That is, a control procedure of which of the three level sensors 31, 32, and 33 uses the detection result (liquid level) from the level sensor Is set in advance.

Specifically, for example, when the liquid surface exists in the overlap portion, the detection result of the level sensor located above is used. For example, when the float of the level sensor 32 and the float of the level sensor 33 are floating on the liquid surface (when the liquid surface exists in the overlapping portion), the detection result (the liquid (Surface height), and the detection result is stored in the memory 62.

When only one float is floating on the liquid surface, for example, the liquid surface is located near the position of the height Hs1 (see FIG. 4) and the rotation angles of the arms of the level sensors 32 and 33 are set. Is approximately 90 degrees as a depression angle (−θ2 = −θ3 = −90
Degree), and when the rotation angle of the arm of the level sensor 31 is approximately 0 degree (θ1 = 0 degree = substantially horizontal), the detection result from the level sensor 31 is adopted, and this detection result is It is stored in the memory 62.

[Control Based on Precondition (4)] That is, sensing is not performed when the vibration of the vehicle body, that is, the liquid tank 10 and the fluctuation of the liquid level are large. Specifically, the fluctuation of the rotation angle of the arm of the level sensor is, for example, within an allowable range of “± 10 degrees”, and the sensing is performed every minute from when the state continues for 10 seconds or more to when the condition is not satisfied. .

[Control Based on Precondition (5)] That is, sensing is not performed when the inclination of the vehicle body, that is, the liquid tank 10 is large. Specifically, sensing is performed only when the inclination angle θT is within a permissible range of, for example, “−15 degrees ≦ θT ≦ + 15 degrees”, and when it is out of the range, no sensing is performed.

This means that it is possible to prevent the detection of the liquid level when the vehicle body, that is, the liquid tank 10 is extremely inclined.

The process of calculating the corrected liquid level, remaining fuel amount, and fuel consumption rate by the controller 60 in the control system having the above configuration will be described with reference to the flowchart shown in FIG.

The controller 60 initializes the data (variables) stored in the memory 62 and indicating the height of the highest fluid level, the height of the lowest fluid level, the fuel consumption, and the engine operating time (step 101). , A preset measurement period, for example, one day (for example, 8
(Time) is completed (step 10).
2).

Here, the initialization will be described. For example,
When the vehicle is used with the new liquid tank 10 filled with fuel of the rated capacity, the initial value is the maximum liquid level height = 0,
Minimum liquid level = 0, consumption = 0, engine operating time =
It becomes 0.

Note that the previous vehicle (predetermined measurement period ends)
When the vehicle is used this time in a state where the fuel in the liquid tank 10 is reduced by using, the initial value of the liquid level is set to the last detected liquid level height = maximum The liquid level height is the minimum liquid level height. That is, if there is no refueling at the end of the previous measurement, the value indicating the minimum liquid level stored in the memory 62 becomes the initial value.

In the following description, a description will be given of a process in a case where the vehicle is used continuously in the fuel state of the vehicle used last time (a state where a predetermined measurement period has been completed).

If the measurement period has not ended in step 102, the controller 60 reads each data from the level sensors 31 to 33, the inclinometer 40 and the like (step 103). That is, a signal indicating an arm rotation angle (float swing angle) from any one of the three level sensors, a signal indicating an inclination angle from an inclinometer 40 (inclination sensor), and a signal indicating an inclination angle from an engine rotation sensor 50. Each data of the signal indicating the engine speed is read. These data are temporarily stored in the memory 62.

The controller 60 executes the following processing based on each data temporarily stored in the memory 62.

That is, the engine operating time is counted based on the data indicating the engine speed (step 10).
4). This engine operation time is counted up until the measurement period ends.

Then, the rotation angle θ of the arm of the level sensor
Based on data indicating i (θi is any one of θ1 to θ3) and data indicating the inclination angle θT of the tank, it is determined whether or not the liquid level in the liquid tank 10 is stable (stationary). (Step 105).

This means that it is determined whether or not the vibration of the vehicle body and the sway of the liquid level are within predetermined ranges (whether or not the above preconditions (4) and (5) are satisfied). Means.

If the liquid level is stable in step 105, the data indicating the rotation angle θi and the inclination angle θT stored in the memory 62 are substituted into the above-mentioned equations (10) and (3) to obtain the corrected liquid level. Is calculated (step 106).

Next, it is determined whether or not the value indicating the corrected liquid level H is larger than the value indicating the maximum liquid level already stored in the memory 62 (step 10).
7).

In step 107, unless the liquid tank 10 is replenished with fuel, it is unlikely that the fuel will increase. Therefore, the corrected liquid level H is set to the maximum liquid level as the initial value. Cannot be higher than the height of

If the corrected liquid level height H is equal to or less than the highest liquid level in step 107, the corrected liquid level height H is greater than the lowest liquid level height. It is determined whether it is low (step 108).

If the corrected liquid level height H is lower than the minimum liquid level in step 108, the minimum value of the liquid level is updated (step 109). That is, the data indicating the lowest liquid level stored in the memory 62 is rewritten to the data indicating the corrected liquid level height H.

This is because the fuel in the liquid tank 10 decreases unless fuel is replenished in the case of continuously measuring from the previously measured state, so the value indicating the minimum liquid level is This means that the value is updated to a value indicating the corrected liquid level H with the sensing of the liquid level.

When step 109 is completed, or when the corrected liquid level height H is equal to or greater than the minimum liquid level in step 108, the process returns to step 102, and the steps after this step are executed.

If the corrected liquid level H is higher than the maximum liquid level in step 107, it means that fuel has been replenished, and the controller 60
Adds the replenishment amount of the supplied fuel to the fuel consumption amount, and updates the value indicating the maximum liquid level to a value indicating the corrected liquid level H (step 110). This step 110
The replenishment amount in (1) is obtained by calculating the above equation 11 by setting (the corrected liquid level H-the maximum liquid level) a new liquid level H.

After step 110 is completed, the value indicating the minimum liquid level is updated to the value indicating the corrected liquid level H (step 111), and thereafter, the process returns to step 102.

Thereafter, unless it is determined in step 102 that the measurement period has not ended, step 102
The processing up to 109 is repeated. In this case, the value indicating the lowest liquid level (the same value as the value indicating the highest liquid level) updated in step 111 is the corrected liquid level according to the sensing of the liquid level. Will be updated to a value indicating the height H of.

When it is determined in step 102 that the measurement period has ended, the fuel consumption is calculated (step 112). At the end of the measurement period, data indicating the maximum and minimum values of the liquid level and the engine operating time are stored in the memory 62, and at the end of step 112, the data indicating the fuel consumption is stored. Stored in the memory 62.

Therefore, the fuel consumption amount is, for example, {fuel consumption amount Q = fuel supply amount q + remaining amount Vma based on the height of the maximum liquid level.
It can be obtained by calculating the expression of x-the remaining amount Vmin｝ based on the minimum liquid level. By dividing the fuel consumption calculated in this way by the engine operating time, an average fuel consumption rate for a certain period (measurement period) can be calculated.

Note that the replenishment amount q is represented by (the corrected liquid level H
−highest liquid level) as a new liquid level height H by calculating the above equation 11, and the remaining amount Vmax and the remaining amount Vmin are calculated as the height of the highest level stored in the memory 62. The data indicating the height and the data indicating the height of the lowest liquid level are obtained by calculating the above formula 11 as the liquid surface height H.

Next, the processing of the controller 60 for calculating the fuel consumption rate based on the height of the liquid level and the fuel consumption thus calculated will be described with reference to FIG.

FIG. 7 is an explanatory diagram for explaining the processing of the controller 60 for calculating the fuel consumption rate.

The controller 60 includes a level sensor 31,
Data indicating a rotation angle θi (θi is any of θ1 to θ3) from one of the level sensors 32 and 33;
Based on the data indicating the tilt angle θT from the inclinometer 40 (P201), the above equation 11 is calculated and the remaining fuel amount V =
Qrest is calculated (P202), and the remaining fuel amount Qrest and the remaining fuel counter are referred to (P2).
03) Based on the obtained count value Qrest-b, a process of calculating the fuel change amount ΔQ (that is, ΔQ = “Qrest-b”)
-Update the count value of the fuel remaining amount counter by executing the expression "Qrest" (P204).

Next, the integrated fuel consumption amount Qtotal is obtained by integrating the fuel change amount ΔQ. That is, the equation of Qtotal = ΣΔQ (unit: liter) is calculated (P205). When the fuel is increased by replenishment, the increase (fuel change amount ΔQ) is not integrated as the fuel consumption. That is, step 110
The replenishment amount (fuel change amount ΔQ) obtained by the processing of
It is not added to the integrated fuel consumption Qtotal.

Further, as an initialization before the start of the processing in P201, the measurement period for performing this sensing, that is, the count value of the fuel consumption calculation counter for measuring the time is reset (P206), and the processing in P201 is performed. (P207), the count value of the fuel consumption calculation counter is updated with the passage of time (at the same time as the level sensor senses the liquid level).

Then, a preset measurement period (time) T
Is reached, this measurement period (time) T and P205
The average fuel consumption rate Qrate is calculated based on the integrated fuel consumption Qtotal calculated in. That is, an equation of Qrate = Qtotal / T (unit: liter) is calculated (P208).

In the above-described embodiment, the level sensors 31, 32, 3 are set so that the detection ranges of the liquid levels overlap.
3, the level sensors 31, 32, and 33 detect the height (the liquid level) of the liquid tank 10 obtained by dividing the height H0 into three equal parts. May be arranged at a predetermined position in the z direction (height direction) of the side surface 11. Of course, in this case, the liquid level at the height corresponding to the boundary line is detected by the upper and lower level sensors.

Although the description has been given of the detection of the liquid level when three level sensors are used, the present invention is not limited to this, and the liquid level can be detected using one level sensor as in the principle described in FIG. The height of the surface can also be detected.

This means that the fuel tank 10 is effective when the width is long and the height is low.

Further, according to the depth of the liquid level tank, that is, the height of the liquid level tank, and the arm length of the level sensor, the level of the liquid is detected using two or four or more level sensors. Can also.

As described above, detecting the liquid level using a plurality of level sensors can be performed when the width of the fuel tank 10 is short and high (vertical tank) or when the fuel tank 10 is large. Means that it is valid.

Further, in this embodiment, personal computer 70 stores the data (data such as the calculation result by CPU 63) transferred from controller 60 in an external storage device (not shown) which is locally connected to itself. You may do it.

As described above, according to the present embodiment, the height of the liquid surface calculated based on the rotation angle θi of the arm of the level sensor is corrected based on the inclination angle θT of the liquid tank 10, and Since the remaining amount of the liquid fuel is calculated based on the height of the liquid surface after this correction, the position of a distance shorter than the distance from the side surface of the liquid tank 10 to the vicinity of the center of the liquid tank 10 is calculated. In this case, a level sensor for detecting the level of the liquid level at the time is adopted, and even when the vehicle body, that is, the liquid tank 10 is inclined, an accurate remaining fuel amount can be calculated.

[Brief description of the drawings]

FIG. 1 is a principle diagram showing the principle of a device for detecting the remaining amount of a liquid tank.

FIG. 2 is a principle diagram in which the state shown in FIG. 1 is rewritten for easy explanation.

FIG. 3 is a diagram for explaining a mounting state of a sensor when a plurality of float type level sensors and an inclination angle sensor are arranged.

FIG. 4 is a diagram illustrating a state for explaining definitions of sensing values of a rotation angle θi and a tilt angle θT;

FIG. 5 is a system configuration diagram showing a control system.

FIG. 6 is a flowchart illustrating a calculation operation of a liquid level and a fuel consumption amount;

FIG. 7 is an explanatory diagram illustrating a calculation process of a fuel consumption rate.

FIG. 8 is a side view showing a conventional fuel tank.

FIG. 9 is a side view showing a conventional fuel tank.

FIG. 10 is a side view showing a conventional fuel tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Liquid tank 20, 31-33 Float type level sensor 21 Sensor main body 22 Arm 23 Float 40 Inclinometer 50 Engine rotation sensor 60 Controller

Continued on the front page (72) Inventor Kunihiko Imanishi 3-1-1 Ueno, Hirakata-shi, Osaka Prefecture F-term (reference) 2F013 AA01 BB01 CB01 3D038 CA31 CB09 CD00

Claims (7)

[Claims] An apparatus for detecting a liquid level of a liquid in a liquid tank mounted on a vehicle and obtaining a remaining amount of the liquid based on a result of the detection. Detecting means for detecting the height of the liquid surface at a position shorter than the distance from the side surface of the liquid tank to the vicinity of the center of the liquid tank; tilt angle detecting means for detecting the tilt angle of the tilted liquid tank; Correction means for correcting the height of the liquid level detected by the detection means based on the inclination angle detected by the angle detection means; and data based on the liquid level height after correction by the correction means. And a calculating means for calculating the remaining amount of the liquid. 2. A level sensor for detecting a height of a liquid surface based on information indicating a position of a float floating on the liquid surface in the liquid tank,
The remaining amount detection device for a liquid tank according to claim 1, further comprising: 3. The level sensor, wherein the other end of an arm having a float floating on the liquid surface in the liquid tank at one end is rotatably supported on a side surface of the liquid tank, and the float is at a height of the liquid surface. The height of the liquid surface based on the rotation angle of the arm when the arm is rotated by floating in response to the arm and the height from the bottom surface of the liquid tank to a position where the arm is rotatably supported. The remaining amount detection device for a liquid tank according to claim 2, wherein the remaining amount is detected. 4. The detection means, wherein the other end of an arm having a float floating on the liquid surface in the liquid tank at one end is rotatably supported on a side surface of the liquid tank, and the float is at a height of the liquid surface. The height of the liquid surface based on the rotation angle of the arm when the arm is rotated by floating in accordance with the height and the height from the bottom surface of the liquid tank to the position where the arm is rotatably supported. A level sensor for detecting the height, wherein a height from a position near the bottom surface of the liquid tank to a position near the top surface of the liquid tank is divided by N (N is a positive integer), and a range corresponding to each height is defined by: N level sensors for detecting the liquid level,
Wherein the correction unit detects the height of the liquid surface detected by the level sensor having a float floating on the liquid surface among the N level sensors, and detects the height of the liquid surface by the inclination angle detection unit. 2. The apparatus according to claim 1, further comprising: means for correcting based on the inclination angle.
The remaining amount detection device for a liquid tank according to claim 1. 5. The calculating means calculates a product of data indicating a corrected liquid level height corrected by the correcting means and data indicating a preset bottom area of the liquid tank, The remaining amount detection device for a liquid tank according to claim 1 or 4, wherein the remaining amount of the liquid in the liquid tank is calculated. 6. The method according to claim 1, wherein a variation in the detected value of the liquid level detected by said detecting means is within a predetermined allowable range, and
When the state is continued for a preset time or more, the control device further includes control means for causing the correction means to correct the liquid level and for causing the calculation means to calculate the remaining amount of liquid. The liquid remaining amount detecting device according to claim 1 or 4, wherein: 7. When the tilt angle detected by the tilt angle detecting means is a value within a preset allowable range, the correcting means corrects the liquid level and the calculating means controls the liquid level. 7. The liquid remaining amount detecting device according to claim 1, further comprising means for calculating a remaining amount of the liquid.