JP2008014267A - Fuel residual-quantity detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel residual-quantity detector by which residual quantity of fuel is correctly detected even in a fuel tank having a low height and a wide base-area. <P>SOLUTION: A plurality of rodlike liquid-level detectors 20 are provided in the fuel tank 11 radially slantingly downward. Each of the detectors 20 sunk in the liquid detects the length of sinking from the tip end to the liquid-level position. The residual-quantity of the fuel in the fuel tank 11 is detected on the basis of length L to the liquid-level position detected by each liquid-level detector 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel remaining amount detection device that detects a remaining fuel amount in a fuel tank.

  2. Description of the Related Art Conventionally, a fuel remaining amount detection device that detects the remaining amount of fuel in a fuel tank is known (see Patent Document 1).

  Such a fuel remaining amount detecting device has two fuel sensors arranged at different positions in the fuel tank.

The fuel sensor is designed to detect the remaining amount of fuel by detecting the rotation of the rear part of the arm with a potentiometer by attaching the rear part of the arm with the float attached to the tip to the top plate of the fuel tank. It has become.
Japanese Patent Laid-Open No. 11-200971

  In such a fuel remaining amount detecting device, in the case of a fuel tank having a low height and a wide bottom area, the fuel is greatly biased during acceleration / deceleration, turning or climbing. For this reason, there is no fuel at the float position in the fuel tank, the remaining amount of fuel detected by the fuel sensor becomes zero despite the presence of fuel, and the fuel gauge displays “EMPTY”. there were.

  An object of the present invention is to provide a fuel remaining amount detection device that can reliably determine the remaining amount of fuel even in a fuel tank having a low height and a wide bottom area.

In the present invention, a plurality of rod-shaped liquid level detection members that are immersed in the liquid and detect the length from the tip part to the liquid level position are arranged in the fuel tank diagonally downward and radially,
The fuel remaining amount in the fuel tank is obtained based on the length to the liquid level position detected by each liquid level detection member.

  According to the present invention, the remaining amount of fuel can be reliably obtained even in a fuel tank having a low height and a wide bottom area.

  Hereinafter, an embodiment as an embodiment of a fuel remaining amount detection apparatus according to the present invention will be described with reference to the drawings.

  In FIGS. 1 and 2, reference numeral 10 denotes a fuel remaining amount device that detects the remaining amount of fuel in the fuel tank 11. The fuel remaining amount device 10 includes a plurality of rod-shaped liquid level detectors (liquid level detection members) 20 attached to the upper part of the pump module unit 12. The plurality of liquid level detectors 20 are disposed in the fuel tank 11 obliquely downward and radially. The fuel tank 11 has a low height and a wide bottom area.

  As shown in FIG. 3, the liquid level detection body 20 includes a first cylinder 21, a second cylinder 22 that is movably inserted into the first cylinder 21 from the upper end of the first cylinder 21, and A spring 23 disposed in the first cylinder 21, a sensor holder 25 attached to the tip of the first cylinder 21 and having a hemispherical holding part 24, and attached in the holding part 24 And a liquid level detecting element 30 and the like.

  The spring 23 is provided between a flange 22 </ b> F formed in the lower part of the second cylinder 22 and a flange 25 </ b> F formed in the sensor holding body 25, and the second cylinder 22 is inclined from the upper end of the first cylinder 21. It is biased in the direction of protruding upward.

  A hook-like locking portion 21B is formed on the upper portion of the first cylinder 21, and the fuel in the fuel tank 11 can freely enter the first and second cylinders 21 and 22 from a hole or a gap (not shown). It is possible to flow in and out.

  A rotation plate 26 is fixed to the upper portion of the second cylinder 22, and this rotation plate 26 is rotatably attached to a shaft 14 provided on the lid body 13 of the pump module unit 12. The rotating plate 26 can rotate about the shaft 14 integrally with the liquid level detector 20. A torsion coil spring 28 is attached to the shaft 14, and the torsion coil spring 28 urges the rotating plate 26 counterclockwise in FIG.

  A stopper 29 is formed on the rotation plate 26, and the rotation of the rotation plate 26 is restricted by the stopper 29 engaging with the protrusion 16 provided on the top plate portion 15 of the pump module unit 12. The rotation angle of the rotation plate 26 is set to be a predetermined angle (θ1 shown in FIG. 2).

  As shown in FIG. 4, the liquid level detection element 30 includes a transmission unit 31 that transmits ultrasonic waves using a piezo element and a reception unit 32 that receives reflected ultrasonic waves. The distance from the transmission unit 31 to the liquid level (the length from the transmission unit 31 to the liquid level) is determined by the time from the transmission to the reflection by the liquid level and reception by the reception unit 32.

  The pump module unit 12 has a pump main body 16 (see FIG. 5) having a pump P, and a plurality of locking pieces 17 are provided in a case K of the pump main body 16. An acceleration sensor G (see FIG. 2) is attached to the back surface of the top plate portion 15 of the pump module unit 12.

  FIG. 5 shows the pump module unit 12 before the plurality of liquid level detectors 20 are deployed. The locking portion 21 </ b> B of the first cylinder 21 of each liquid level detection body 20 is engaged with the locking piece 17 of the case K of the pump module unit 12. By this engagement, each liquid level detection body 20 is not expanded by the urging force of the torsion coil spring 28. The second cylinder 22 is retracted and contracted in the first cylinder 21. The front end portion of each liquid level detection body 20, that is, the holding portion 24 is located below the bottom portion 12 </ b> T of the pump module unit 12.

  Then, the pump module unit 12 is inserted into the mounting hole 11A of the fuel tank 11 as shown in FIG. 6, and the holding portions 24 of the respective liquid level detectors 20 are connected to the bottom 11T of the fuel tank 11 as shown in FIG. Abut. Next, the pump module unit 12 is pressed to press the bottom 12T of the pump module unit 12 against the bottom 11T of the fuel tank 11.

  At the time of this pressing, as shown in FIG. 8, the holding portion 24 of the liquid level detector 20 is in contact with the bottom portion 11T of the fuel tank 11, so that the second cylinder 22 of the liquid level detector 20 is 5 is further inserted into the first cylinder 21 against the urging force of the spring 23 from the state shown in FIG. That is, the first cylinder 21 moves relatively upward with respect to the second cylinder 22.

  By the upward movement of the first cylinder 21, the locking portion 21B of the first cylinder 21 of the liquid level detection body 20 is disengaged from the locking piece 17 of the case K of the pump module unit 12 as shown in FIG. .

  Each liquid level detection body 20 is expanded as shown in FIGS. 9 and 10 by the urging force of the torsion coil spring 28, and the second cylinder 22 is moved relative to the first cylinder 21 by the urging force of the spring 23. Will continue to grow. That is, the first cylindrical body 21 extends along the second cylindrical body 22 toward the tip (lower end) direction of the second cylindrical body 22.

  As a result, the liquid level detectors 20 are arranged in the fuel tank 11 radially and obliquely downward as shown in FIGS. 1 and 2.

  Here, the angles θ1 and θ2 shown in FIGS. 1 and 2 are set in advance, and the position of the bottom portion 11T of the fuel tank 11 with which the holding portion (tip portion) 24 of each liquid level detector 20 abuts is also set in advance. Has been.

  Then, by measuring the length L from the liquid level detection element 30 to the liquid level in the first cylinder 21 or the second cylinder 22 by the liquid level detection element 30, the liquid level in the cylinders 21 and 22 is measured. Can be obtained as coordinates in the fuel tank 11.

  That is, assuming that the position of the liquid level detection element 30 is the origin, the X and Y distances from the origin to the liquid level position P and the height Z to the liquid level position P can be obtained by the following equations.

X = Lsinθ1 × cosθ2
Y = Lsinθ1 × sinθ2
Z = Lcosθ1
When three or more liquid level positions P can be obtained by three or more liquid level detectors 20, as shown in FIGS. 11 and 12, the fuel tank 11 is moved from the three point positions P1 to P3 in the fuel tank 11. The entire position of the liquid level S1 can be specified. Then, the relationship between the specified liquid level S1 and the remaining fuel amount is measured in advance and stored as a map, and the remaining fuel amount is obtained from the specified liquid surface S1 obtained from the three point positions P1 to P3. .

  As shown in FIG. 11 and FIG. 12, even if the fuel tank 11 has a low height and a wide bottom area, and the fuel is greatly biased, the plurality of liquid level detectors 20 are obliquely downward and radially in the fuel tank 11. By being arranged, the three point positions P1 to P3 in the fuel tank 11 can be detected by the three or more liquid level detectors 20, so that the remaining amount of fuel can be obtained reliably.

  When the remaining fuel level is low and the liquid level position does not reach 3 points or more, the acceleration detected by the acceleration sensor G and the liquid level position P4 (see FIG. 13) detected by one liquid level detector 20 are obtained. Based on this, the remaining amount of fuel is obtained. That is, the inclination angle of the liquid level is obtained based on the acceleration detected by the acceleration sensor G, and the fuel is obtained from this inclination angle and the liquid level position P4 detected by one liquid level detector 20 as shown in FIGS. The liquid level S2 in the tank 11 is specified, and the remaining amount of fuel is obtained from the specified liquid level S2.

  When the pump module unit 12 is lifted from the mounting hole 11A of the fuel tank 11, each liquid level detector 20 rotates in a direction in which the angle θ1 decreases against the biasing force of the torsion coil spring 28. Each liquid level detector 20 can be easily removed, and maintenance is easy.

  In the above-described embodiment, the liquid level detector 20 is configured to expand and contract. However, the liquid level detector 20 need not be configured to expand and contract as long as it can be radially arranged in the fuel tank 11 in advance. Further, although the liquid level position is detected by ultrasonic waves by the liquid level detection element 30, the liquid level position may be obtained using a variable resistor instead of the liquid level detection element 30. In this case, the first and second cylinders 21 and 22 are unnecessary.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various design changes can be made without departing from the scope of the invention.

It is the top view which showed the structure of the fuel residual amount apparatus which concerns on this invention. It is sectional drawing which follows the AA line of FIG. FIG. 2 is an enlarged cross-sectional view illustrating a configuration of a liquid level detection body of the fuel remaining amount device in FIG. 1. It is the perspective view which showed the liquid level detection element. It is sectional drawing which showed the pump module unit and the liquid level detection body attached to this. It is explanatory drawing which showed the state before attaching a pump module unit to a fuel tank. It is explanatory drawing which showed the state which inserted the pump module unit in the fuel tank. It is explanatory drawing which showed the state which the latching | locking part of the liquid level detection body removed from the latching piece of the pump module unit. It is explanatory drawing which showed the state which the liquid level detection body began to expand | deploy from a pump module unit. It is explanatory drawing which showed the state which the liquid level detection body expand | deployed from the pump module unit. It is the top view which showed the state in which the fuel in a fuel tank was greatly biased. It is sectional drawing which showed the state in which the fuel in a fuel tank was greatly biased. FIG. 5 is a plan view showing a state where a small amount of fuel in the fuel tank is largely biased. It is sectional drawing which showed the state in which the little fuel in the fuel tank was greatly biased.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Fuel tank 12 Pump module unit 20 Liquid level detection body 21 1st cylinder 22 2nd cylinder 30 Liquid level detection element

Claims (5)

A plurality of rod-shaped liquid level detection members that detect the length of immersion from the tip to the liquid level position are disposed in the fuel tank diagonally downward and radially,
A fuel remaining amount detecting device characterized in that a fuel remaining amount in a fuel tank is obtained based on a length to a liquid level position detected by each liquid level detecting member. With an acceleration sensor,
When there are three or more liquid level detection members that can determine the length to the liquid level position, the remaining amount of fuel in the fuel tank is determined based on the length of the liquid level detection member to the liquid level position,
When there are two or less liquid level detection members whose length to the liquid level position can be obtained, the acceleration sensor detects the length to the liquid level position detected by the two or less liquid level detection members. The fuel remaining amount detecting device according to claim 1, wherein the remaining fuel amount is obtained based on acceleration.   The plurality of liquid level detection members are attached to a pump module unit that is inserted into the fuel tank from an opening of the fuel tank, and when the pump module unit is attached to the fuel tank, the liquid level detection members are radially expanded to form a fuel tank. The fuel remaining amount detecting device according to claim 1, wherein the fuel remaining amount detecting device is disposed inside the fuel remaining amount detecting device.   The liquid level detection member includes a pipe body through which fuel can flow in and out, and a liquid level detection element that is provided at a distal end portion in the tubular body and obtains a length from the distal end portion to the liquid level position in the tubular body. The fuel remaining amount detecting device according to any one of claims 1 to 3, wherein   The fuel remaining amount detecting device according to claim 4, wherein the tubular body is extended when radially expanded.

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