JP2001356040A - Fuel gauge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability and durability by eliminating moving contacts from a fuel gauge. SOLUTION: A fuel pump 6 and the like are set to a pump setting bracket 2 of a fuel feed system 1 and also a casing-storing part 2C is formed. The fuel gauge 11 is constituted of an arm 12, a float 13 and a level detector 14. A casing of the level detector 14 is set to the casing-storing part 2C. The casing is provided with a magnet rotating together with the arm 12, a first and a second yokes opposite to the magnet. A Hall element is arranged between the first and the second yokes. A cover 2 is fitted to the casing in this state to prevent the magnet from falling off. The Hall element outputs detection signals corresponding to an opposite area between the magnet and the first, second yokes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel gauge suitable for detecting, for example, the remaining amount of fuel in a fuel tank of an automobile.

[0002]

2. Description of the Related Art In general, fuel gauges are, for example,
As disclosed in Japanese Patent No. 28345/28, etc., there is known a float composed of a float floating on a liquid surface in a fuel tank and a variable resistor connected to the float and having a resistance value which changes according to the height of the liquid surface. Have been. In the fuel gauge according to the related art, a slider having a variable resistance is connected to the float via an arm or the like, and the slider moves following the float floating on the liquid surface of the fuel in the fuel tank. As a result, since the resistance value of the variable resistor changes, a constant voltage power supply that applies a constant voltage to the variable resistor is connected, and by detecting the current flowing through the variable resistor, the liquid level of the fuel in the fuel tank, That is, the remaining fuel amount is detected.

[0003]

In the fuel gauge according to the prior art described above, a variable resistor whose resistance changes according to the contact position of a slider is used in a state of being immersed in a fuel such as gasoline. For this reason, an insulating film may be formed on the sliding contact between the slider and the resistor due to sulfur components and additives in the gasoline, and the remaining fuel amount can be detected by such an insulating film. There is a risk of disappearing.

Further, since a variable resistor having a sliding contact is used, the resistor and the slider tend to wear in proportion to the number of operations. Therefore, when used for a long period of time, there is also a problem that the accuracy of detecting the remaining fuel amount gradually decreases.

[0005] Further, since the fuel gauge is installed in the fuel tank, when the above-described defect occurs,
The fuel tank needs to be removed from the vehicle and repaired. Therefore, there is a problem that the trouble and cost for repairing the defect of the fuel gauge increase, and that the fuel gauge itself becomes expensive due to measures against sulfur and additives in gasoline.

Further, when the fuel gauge is attached to the fuel pump, the number of parts tends to increase because the fuel gauge is fixed to a bracket or the like of the fuel pump using a technique such as snap fitting. For this reason, there is a problem that the manufacturing cost is increased and the reliability is likely to be reduced due to an increase in the number of joints.

In the fuel gauge according to the prior art, the amount of change in the resistance value is uniquely defined by the total length of the sliding portion of the resistor and the stroke amount per unit angle. There is also a problem that it is necessary to adapt.

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 gauge having improved reliability and durability by eliminating sliding contacts from the fuel gauge. And

[0009]

In order to solve the above-mentioned problems, the present invention provides an arm whose base end is rotatably supported by a bracket provided in a fuel tank, and an arm provided at a distal end of the arm. The present invention is applied to a fuel gauge comprising: a float that is displaced in accordance with a liquid level of fuel in the fuel tank; .

The first aspect of the present invention is characterized in that the liquid level detecting means includes a casing provided at a base end of an arm, and a magnet provided in the casing and rotating together with the arm. A first and a second yoke provided on the casing and opposed to each other with the magnet interposed therebetween; and a first yoke provided between the first and the second yokes, And a signal output means for outputting a signal corresponding to the facing area.

With this configuration, the float is displaced in accordance with the level of the fuel in the fuel tank, and the base end of the arm rotates. At this time, the magnet rotates together with the arm, and the facing area between the magnet and the first and second yokes changes according to the rotation angle of the arm. Since the signal output means outputs a signal corresponding to the area of the magnet and the first and second yokes facing each other, using the signal output from the signal output means enables the rotation angle of the arm,
That is, the fuel level can be detected.

In the invention of claim 2, the bracket is a pump mounting bracket for mounting the fuel pump, and the casing is provided on the pump mounting bracket.

Thus, the fuel gauge can be attached to the fuel pump, and the fuel gauge can be arranged in the fuel tank together with the fuel pump.

Further, the invention according to claim 3 is that the casing is constituted by a cylindrical projection formed on the pump mounting bracket.

Thus, the casing can be formed integrally with the pump mounting bracket, and a fuel gauge can be formed by attaching a magnet or the like to the casing.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a fuel gauge according to an embodiment of the present invention will be described in detail with reference to FIGS.

First, FIGS. 1 to 7 show a first embodiment of the present invention, in which 1 is a fuel supply device disposed in a fuel tank, and the fuel supply device 1 is a pump mounting bracket described later. 2. It is composed of a fuel pump 6, a fuel filter 7, and the like.

Reference numeral 2 denotes a pump mounting bracket mounted on the upper side of the fuel tank.
It is composed of a lid 2A formed of a resin material and fixed to the fuel tank, and a mounting cylinder 2B hanging from the lid 2A into the fuel tank. And lid part 2
A has a supply pipe 3 for supplying fuel to the outside of the fuel tank,
A suction pipe 4 for sucking fuel in the sub tank and a return pipe 5 for returning surplus fuel to the fuel tank are provided.

Further, a casing accommodating portion 2C for accommodating a casing 15 of the fuel gauge 11, which will be described later, is provided in the mounting cylinder portion 2B so as to protrude in a cylindrical shape. Further, the lid 2A is provided with a connector 2D for supplying driving power to a fuel gauge 11 described later, outputting a signal, and the like.

Reference numeral 6 denotes a mounting cylinder 2 of the pump mounting bracket 2.
The fuel pump 6 is a substantially columnar fuel pump provided in B. The fuel pump 6 has a suction port 6A to which a suction filter and the like are attached. Then, the fuel pump 6 sucks the fuel in the fuel tank from the suction port 6A, and discharges this fuel toward a fuel filter 7 described later.

Reference numeral 7 denotes a fuel filter provided on the pump mounting bracket 2. The fuel filter 7 filters fuel discharged from the fuel pump 6 by a filter element (not shown), and supplies purified fuel to a supply pipe. Discharge from 3.

Reference numeral 8 denotes a suction pump for the sub tank provided on the pump mounting bracket 2. The suction pump 8 is constituted by a so-called jet pump, and is connected to the suction pipe 4 and the return pipe 5. And the suction pump 8
The fuel in the sub-tank is sucked into the fuel tank using the flow of the fuel returning to the fuel tank through the return pipe 5.

Next, the fuel gauge 11 attached to the fuel supply device 1 will be described.

Reference numeral 11 denotes a fuel gauge provided on the pump mounting bracket 2 of the fuel supply device 1.
Is generally constituted by an arm 12, a float 13, and a liquid level detecting device 14, which will be described later.

Reference numeral 12 denotes an arm rotatably supported by a pump mounting bracket 2 of the fuel supply device 1 via a liquid level detecting device 14 to be described later. A support portion 12A extending toward
A swing arm portion 12B which is bent from the support portion 12A and is swingable about the support portion 12A;
B and a mounting portion 12C to which the float 13 is mounted at the front end.

Reference numeral 13 denotes a float attached to the tip of the arm 12. The float 13 follows the liquid surface of the fuel in the fuel tank and floats on the liquid surface. Thereby, the float 13 swings the arm 12 about the support portion 12A.

Reference numeral 14 denotes a liquid level detecting device which is located on the base end side of the arm 12 and is mounted on the casing accommodating portion 2C of the pump mounting bracket 2. The liquid level detecting device 14 includes a casing 15, a It is composed of the second yokes 18, 19, the Hall element 21 and the like.

A casing 15 is accommodated in a casing accommodating portion 2C of the pump mounting bracket 2. The casing 15 is formed of a non-magnetic material such as a resin material and has a closed cylindrical shape. 18, 19 are integrally held by means such as a resin mold.
Then, the casing 15 includes the first and second yokes 18, 1.
For example, the first yoke 18 and the second yoke 18, which are adhered to the
19 are performed.

Reference numeral 16 denotes a rotating plate attached to the support portion 12A of the arm 12. The rotating plate 16 is formed in a substantially disk shape.
A magnet 17 described later is fixed on the rotating plate 16. The support portion 12A of the arm 12 is provided with a retaining portion 12A1 protruding radially outward. The rotating plate 16 is fixed in a state where the support portion 12A is prevented from being removed by performing resin molding in a state where the stopper portion 12A1 is buried.

The rotating plate 16 has a sliding shaft portion 16A having an outer diameter substantially equal to the inner diameter of the casing 15.
And a flange 16 formed with a larger diameter than the sliding shaft 16A.
B form a stepped disk. And
In the rotating plate 16, the sliding shaft portion 16 </ b> A is inserted into the casing 15 in a state where the opening side of the casing 15 is closed, and the flange portion 16 </ b> B contacts the opening end of the casing 15.
Thus, the rotating plate 16 is configured such that the sliding shaft portion 16 </ b> A slides on the casing 15 and rotates.

Reference numeral 17 denotes a magnet fixed on the rotating plate 16 with an adhesive or the like. The magnet 17 is formed in a rectangular or oval shape having magnetic poles on both sides in the length direction. The magnet 17 has convex arcuate surface portions 17A and 17B on both longitudinal end surfaces, and the convex arcuate surface portions 17A and 17B.
Between 17B are parallel plane portions 17C and 17D. The convex arc-shaped surface portions 17A and 17B of the magnet 17 are formed at an angle α1 of, for example, about 90 ° with respect to the rotation center OO.

Reference numeral 18 denotes a first member mounted on the casing 15.
The first yoke 18 guides the magnetic flux generated by the magnet 17 to a Hall element 21 described later. The yoke 18 is formed by bending a first magnetic pole piece 18A in the shape of a curved plate facing the convex arcuate surfaces 17A and 17B of the magnet 17 and bending radially inward from the first magnetic pole piece 18A. , And a first overhang portion 18 </ b> B extending in a plate shape so as to straddle the magnet 17. Further, the first pole piece 18A is provided with a rotation center OO.
For example, the overhang portion 18B of the yoke 18 partially covers the magnet 17 at an angle α2 of about 90 °.

Reference numeral 19 denotes a second member mounted on the casing 15.
The second yoke 19 forms a magnetic circuit by radially opposing the first yoke 18 with the magnet 17 interposed therebetween, and guides the magnetic flux generated by the magnet 17 to a Hall element 21 described later. It is. The yoke 19 has a second magnetic pole piece 19A opposed to the convex arc portions 17B and 17A of the magnet 17 like the yoke 18.
And a second overhang portion 19B which is formed by bending inward in the radial direction from the second pole piece 19A and extends in a plate shape so as to straddle the magnet 17.

The second magnetic pole piece 19A radially opposes the first magnetic pole piece 18A with the magnet 17 interposed therebetween, and the first magnetic pole piece 18A with respect to the center of rotation OO.
A extends at almost the same angle α2 as A.

On the other hand, the second overhang portion 19B partially extends to a position beyond the rotation center OO of the magnet 17, and partially overlaps with the first overhang portion 18B with a predetermined gap. . And the first,
Between the second overhang portions 18B and 19B, a Hall element 21 described later is provided. Accordingly, the first and second overhang portions 18B and 19B are configured to sandwich both sides of the Hall element 21 in the axial direction.

The first and second pole piece portions 18A, 19
When A faces the convex arc surface portions 17A and 17B of the magnet 17 over almost half the surface, the float 13 is stopped at the lowest position (bottom side) as shown in FIG.
When the float 13 moves in the direction of arrow A as the liquid level rises as shown in FIG. 2, the magnet 17 rotates in the direction of arrow B as shown in FIG. The opposing areas of the piece portions 18A, 19A and the convex arc surface portions 17A, 17B gradually decrease. When the float 13 moves to the intermediate position, the first and second pole piece portions 1 are moved.
The convex arcuate surface portions 17A and 17B of the magnet 17 move to an intermediate position between the first and second magnetic pole piece portions 18A and 19A.
A, 19A and the convex arcuate surface portions 17A, 17B have the smallest opposing area. Further, when the float 13 rises and moves to the highest position, the first and second pole piece portions 1 are moved.
8A and 19A are convex arcuate surface portions 17B of the magnet 17;
It faces 17A almost over the half surface.

A flexible substrate 20 made of a resin material or the like has a Hall element 21 mounted on the flexible substrate 20 as shown in FIG.
The 19 overhang portions 18B, 19B are disposed in the gap between the overhang portions 18B, 19B.

Reference numeral 21 denotes a Hall element as signal output means. The Hall element 21 is mounted on the flexible substrate 20 and is disposed in a gap between the first and second overhang portions 18B and 19B. The magnetic detection direction of the Hall element 21 is determined by the support portion 12A of the arm 12, which is a rotation axis.
The direction is parallel to the axial direction and orthogonal to the magnetic pole line of the magnet 17. The Hall element 21 outputs a detection signal proportional to the magnetic flux density passing through a magnetic circuit including the magnet 17, the first yoke 18, and the second yoke 19.

The Hall element 21 is connected to a circuit component (not shown) provided on the flexible board 20, and the circuit component is connected to a connector 2D of the pump mounting bracket 2 through wiring or the like. Then, the circuit component calculates a detection signal output from the Hall element 21,
The signal is amplified and output to the outside through the connector 2D.

Reference numeral 22 denotes a cover which is attached by covering the opening side of the casing 15. The cover 22 is formed in a bottomed cylindrical shape, and has a support portion 12 of the arm 12 at the center thereof.
An insertion hole 22A for inserting A is provided. The cover 22 is detachably attached to the opening side of the casing 15 so as to cover the outer peripheral side of the casing 15,
It has a so-called snap-fit structure.

On the inner peripheral side of the bottom of the cover 22, an annular protruding portion 22B is provided. And
The cover 22 is attached to the casing 15 with the rotating plate 16 sandwiched therebetween, and the protrusion 22B abuts on the rear surface of the rotating plate 16 to position the rotating plate 16 in the axial direction. .

Further, the cover 22 has stopper portions 22C, which restrict the rotation range of the arm 12 to about 90 °.
22D is provided to protrude, and the stopper portions 22C, 22
D contacts the swing arm 12B of the arm 12 when the float 13 moves to the lowest position or the highest position, and regulates further movement.

The fuel gauge according to the present embodiment constitutes a two-pole type fuel gauge by the two yokes 18 and 19 as described above. Next, the operation of the fuel gauge will be described with reference to FIG.

First, when the float 13 is at the lowest position, the convex circular arc surface portion 17A of the magnet 17 faces the magnetic pole piece portion 18A of the first yoke 18 and the convex circular arc surface portion 17A.
B faces the pole piece 19A of the second yoke 19. Thereby, the magnetic flux of the magnet 17 is transferred to the first yoke 18.
And the second yoke 19 to the Hall element 21. At this time, the Hall element 21 outputs a positive detection signal corresponding to the magnetic flux density passing through the yokes 18 and 19.

On the other hand, when the float 13 rises and moves to an intermediate position in the height direction, the convex circular arc portions 17A and 17B of the magnet 17 are connected to the first magnetic pole piece 18A and the second magnetic pole piece 19A. Centrally located. At this time, since the convex circular surface portions 17A and 17B of the magnet 17 do not face any of the pole piece portions 18A and 19A, the magnetic flux from the magnet 17 hardly passes through the yokes 18 and 19, and each Hall element Reference numeral 21 outputs a substantially zero detection signal.

When the float 13 further rises and moves to the highest position, the convex circular arc surface portion 17A of the magnet 17 faces the magnetic pole piece portion 19A of the second yoke 19, and the convex circular arc surface portion 17B becomes the first circular arc surface portion 17B. Pole piece part 1 of yoke 18
8A. Thereby, the magnetic flux of the magnet 17 is guided to the Hall element 21 through the first and second yokes 18 and 19. At this time, the Hall element 21 outputs a negative detection signal corresponding to the magnetic flux density passing through the yokes 18 and 19.

As described above, the Hall element 21 is connected to the float 1
Since the detection signal is output in proportion to the height position of No. 3, that is, the liquid level position of the fuel, the remaining fuel amount in the fuel tank can be detected using this detection signal.

Thus, according to the fuel gauge 11 of the present embodiment, the liquid level detecting device 14 includes the magnet 17 rotatably provided in the casing 15 and the magnet 1.
7, the first and second yokes 18, 1 opposed to each other
9, a magnet 17, and first and second yokes 18, 19
Hall element 21 that outputs a signal corresponding to the area facing the device
Therefore, the sliding contact such as the fuel gauge according to the related art can be eliminated, and the non-contact type fuel gauge 11 can be configured.

Therefore, unlike the prior art, the remaining fuel amount cannot be detected due to poor contact at the sliding contact, and the detection accuracy does not decrease due to wear of the sliding contact. Therefore, the remaining fuel amount can be reliably detected over a long period of time, and the reliability and durability of the fuel gauge 11 can be improved.

Further, since maintenance due to failure of the fuel gauge 11 can be eliminated, maintenance costs can be reduced. Further, the fuel gauge 11 does not need to take measures against sulfur in gasoline and additives. In addition, the casing 15 can be integrally formed with the yokes 18 and 19, and can be sub-assembled with the magnet 17 and the cover 22 attached to the casing 15. Therefore, the number of components can be reduced, and the manufacturing process can be simplified, so that the manufacturing cost can be reduced.

Further, the value of the detection signal output from the Hall element 21 with respect to the rotation angle of the magnet 17 can be easily adjusted by using an operational amplifier or the like. Therefore, the fuel gauge 11 according to the present embodiment can be easily applied to various types of fuel tanks without adapting the shape of the arm 12 for each shape of the fuel tank.

Further, unlike the prior art, there is no need to provide a sliding contact on the swing arm portion 12B of the arm 12, and the liquid level detecting device 14 of the fuel gauge 11 is concentrated around the support portion 12A of the arm 12. Therefore, the liquid level detecting device 14 can be reduced in size as compared with the related art.

Further, since the two-pole type fuel gauge 11 is constituted by the two yokes 18 and 19, the whole fuel gauge 11 can be reduced in size as compared with the case where three or more yokes are used. Thus, the structure can be simplified and the manufacturing cost can be reduced.

Also, since the casing 15 is provided on the pump mounting bracket 2 for mounting the fuel pump 6 on the fuel tank, the fuel gauge 11 can be arranged in the fuel tank together with the fuel pump 6.

Next, FIG. 8 shows a second embodiment of the present invention, which is characterized in that the liquid level detecting device is formed integrally with the pump mounting bracket of the fuel supply device. Note that, in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Reference numeral 31 denotes a liquid level detecting device according to the present embodiment. Like the liquid level detecting device 14 according to the first embodiment, the liquid level detecting device 31 includes a cylindrical projection 32 and a first , The second yokes 18 and 19, the Hall element 21 and the like.

Reference numeral 32 denotes a cylindrical projection as a casing integrally formed with the mounting cylinder 2B of the pump mounting bracket 2. The cylindrical projection 32 is formed in a closed cylindrical shape, and has a first and a second cylindrical shape. The yokes 18 and 19 are integrally held by means such as a resin mold. And the cylindrical projection 3
A rotating plate 16 on which an arm 12 and a magnet 17 are mounted is rotatably mounted on the cover 2.
2 retains the retaining state.

Thus, in the present embodiment, substantially the same functions and effects as in the first embodiment can be obtained. However, in the present embodiment, since the cylindrical projection 32 of the liquid level detecting device 31 is formed integrally with the pump mounting bracket 2, the number of parts can be reduced as compared with the first embodiment. . For this reason, the manufacturing cost can be reduced, defects during manufacturing can be reduced, and reliability can be improved. Further, since the cylindrical projection 32 is integrated with the pump mounting bracket 2, two functions of fuel supply and liquid level detection can be integrated into the fuel supply device 1.

Next, FIGS. 9 and 10 show a third embodiment of the present invention. The feature of this embodiment is that the rotary plate of the liquid level detecting device has a cylindrical projection integrally formed with a pump mounting bracket. The part is deformed by heat caulking and fixed. Note that, in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Reference numeral 41 denotes a liquid level detecting device according to the present embodiment. Like the liquid level detecting device 14 according to the first embodiment, the liquid level detecting device 41 includes a cylindrical projection 42 and a first , The second yokes 18 and 19, the Hall element 21 and the like.

Reference numeral 42 denotes a cylindrical projection as a casing integrally formed with the mounting cylinder 2B of the pump mounting bracket 2. The cylindrical projection 42 is formed in a closed cylindrical shape, The yokes 18 and 19 are integrally held by means such as a resin mold. The cylindrical projection 42
At its front end on the opening side, for example, four arc-shaped plate portions 42 are provided.
A is formed to extend in the axial direction. Then, the plate portion 42A of the cylindrical protrusion 42 is mounted on the cylindrical protrusion 42 so as to cover the rotary plate 16 using a means such as thermal caulking as shown in FIG. Deform into a bent state. As a result, the rotating plate 16 is held in the retaining state by the plate portion 42A.

Thus, in the present embodiment, substantially the same operation and effect as in the first embodiment can be obtained. However, in this embodiment, since the cover for stopping the rotation plate 16 is eliminated, the number of parts can be reduced as compared with the first embodiment, and the manufacturing cost can be further reduced. it can.

In each of the above embodiments, the fuel gauge 11 is mounted on the pump mounting bracket 2 of the fuel supply device 1. However, the present invention is not limited to this. For example, a single fuel gauge is provided in the fuel tank. It may be configured to be directly attached to the bracket.

In each of the above embodiments, the rotating plate 16
The magnet 17 is fixed by using a means such as bonding. For example, in a state where the magnet 17 is attached to the support portion 12A of the arm 12, the rotating plate is resin-molded, and the magnet is insert-molded on the rotating plate. May be.

In each of the above embodiments, the two-pole type liquid level detecting devices 14 and 3 are provided by using the two yokes 18 and 19.
However, for example, as described in JP-A-11-264711, a three-electrode type liquid level detecting device may be configured using three yokes,
A liquid level detecting device having four or more electrodes may be used.

[0066]

As described in detail above, according to the first aspect of the present invention, the liquid level detecting means includes a magnet rotatably provided in the casing, and the first and second magnets opposed to each other with the magnet interposed therebetween. 2 and the signal output means for outputting a signal corresponding to the facing area of the magnet and the first and second yokes, so that the sliding contact such as the fuel gauge according to the prior art can be eliminated. It is possible to reliably detect the remaining amount of fuel over a long period of time and improve the reliability and durability of the fuel gauge.

The fuel gauge does not need to take measures against sulfur and additives in the fuel, and the liquid level detecting device can be subassembled, so that the number of components can be reduced and the manufacturing process can be simplified. And the manufacturing cost can be reduced. Further, since the liquid level detecting means can be arranged concentratedly on the base end side of the arm, the liquid level detecting means can be reduced in size as compared with the prior art.

Further, the signal output from the signal output means can easily adjust the value with respect to the rotation angle of the magnet by using an operational amplifier or the like.
The present invention can be easily applied to various types of fuel tanks without adapting the shape of the arm for each shape of the fuel tank.

According to the second aspect of the present invention, since the casing is provided on the pump mounting bracket for mounting the fuel pump on the fuel tank, the fuel gauge can be arranged in the fuel tank together with the fuel pump, and the fuel pump can be mounted on the fuel pump. Can integrate the two functions of fuel supply and liquid level detection.

According to the third aspect of the present invention, since the casing of the liquid level detecting means is constituted by the cylindrical projection integrally formed with the pump mounting bracket 2, the number of parts of the liquid level detecting means is reduced. As a result, the manufacturing cost can be reduced, defects during manufacturing can be reduced, and the reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a fuel supply device provided with a fuel gauge according to a first embodiment of the present invention.

FIG. 2 is a left side view of FIG. 1 showing the fuel supply device.

FIG. 3 shows a fuel gauge liquid level detecting device as indicated by an arrow III in FIG.
FIG. 3 is a longitudinal sectional view as seen from a −III direction.

FIG. 4 is a cross-sectional view of the liquid level detecting device as viewed from a direction indicated by arrows IV-IV in FIG. 3;

FIG. 5 is an exploded perspective view showing the liquid level detecting device according to the first embodiment in an exploded state.

FIG. 6 is a perspective view showing an arrangement relationship of a magnet, a first yoke, a second yoke, and the like according to the first embodiment.

FIG. 7 is a schematic configuration diagram showing an arrangement relationship among a magnet used for a fuel gauge, a first yoke, a second yoke, and a Hall element.

FIG. 8 is an exploded perspective view showing an exploded state of a liquid level detecting device according to a second embodiment.

FIG. 9 is an exploded perspective view showing the liquid level detecting device according to the third embodiment in an exploded state.

FIG. 10 is a longitudinal sectional view showing the liquid level detecting device according to the third embodiment in an assembled state, viewed from a position similar to FIG. 3;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fuel supply device 2 pump mounting bracket (bracket) 2B mounting cylinder 6 fuel pump 11 fuel gauge 14, 31, 41 liquid level detecting device (liquid level detecting means) 15 casing 17 magnet 18 first yoke 18A first magnetic pole Piece 18B first overhang 19 second yoke 19A second pole piece 19B second overhang 21 Hall element (signal output means) 32, 42 cylindrical projection

Claims (3)

[Claims] An arm rotatably supported at a base end thereof by a bracket provided in the fuel tank; and a float provided at a distal end of the arm and displaced in accordance with a liquid level of the fuel in the fuel tank. A fuel level gauge provided at a base end of the arm and outputting a signal corresponding to the displacement of the float; a casing provided at a base end of the arm; A magnet provided in the casing and rotating together with the arm, a first and second yoke provided in the casing and opposed to each other with the magnet interposed therebetween, and between the first and second yokes; A fuel gauge, comprising: signal output means provided for outputting a signal corresponding to an area of the magnet and the first and second yokes facing each other. 2. The fuel gauge according to claim 1, wherein the bracket is a pump mounting bracket for mounting a fuel pump, and the casing is provided on the pump mounting bracket. 3. The fuel gauge according to claim 2, wherein the casing comprises a cylindrical projection formed on the pump mounting bracket.