JP2007305535A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell capable of knowing the remainder of fuel with a simple configuration without visually recognizing the fuel. <P>SOLUTION: A float 4 is provided in a fuel tank 3 in the fuel cell 1. The float 4 is formed by a magnet 5, and an outer shell 6 made of resin for wrapping the magnet 5. A recess 2a is formed at the side of the fuel tank 3 in a casing 2, and a plurality of cylinders 8 made of resin are provided in parallel mutually in the recess 2a. The cylinders 8 are supported rotatably by the inner wall of the recess 2a. Then, the peripheral surface of the cylinders 8 is colored to four equal regions along the circumferential direction, and a green region, an orange region, a blue region, and an orange region are arranged in this order along the circumferential direction. A magnetic body 9 is provided inside the cylinders 8, and the center of gravity is arranged at a position separated from the center axis of the cylinders 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more particularly to a fuel cell that can grasp the remaining amount of fuel without visually recognizing the inside of the fuel tank.

  As a power source for small electronic devices such as notebook personal computers, small audio players, and wireless headsets, fuel cells using methanol or the like as fuel are being put into practical use. This methanol fuel cell (DMFC) is a self-breathing fuel cell. That is, this fuel cell is provided with a fuel tank that holds fuel and a power generation unit that generates power, and methanol moves spontaneously from the fuel tank to the power generation unit by capillary action or diffusion phenomenon. Yes. On the other hand, oxygen is taken into the power generation unit from the atmosphere. The power generation unit generates electric power in the process of generating water and carbon dioxide from methanol and oxygen.

In such a fuel cell, the user can always recognize the remaining amount of fuel so that the user can know the usable time of the electronic device in which the fuel cell is mounted and can determine whether or not fuel replenishment is necessary. preferable.
Therefore, a technology has been proposed in which a part of the fuel tank is formed of a transparent material and a viewing window is provided in the casing of the electronic device so that the inside of the fuel tank can be visually recognized from the outside of the electronic device (for example, (See Patent Document 1). Patent Document 1 describes that the user can directly visually recognize the remaining amount of fuel.

  However, in this technique, when a transparent liquid such as methanol is used as the fuel, there is a problem that the liquid level of the fuel is difficult to visually recognize. In addition, a viewing window must be provided in the casing of the fuel cell and the casing of the electronic device, and there is a problem that the design of the electronic device is greatly restricted. Furthermore, since an electronic device employing this technology is always provided with a viewing window for visually recognizing the fuel, there is also a problem that design restrictions are large.

JP 2004-335331 A

  An object of this invention is to provide the fuel cell which can grasp | ascertain the residual amount of fuel with a simple structure, without visually recognizing fuel.

According to one aspect of the invention,
A fuel tank that holds the fuel;
A float provided with a magnet to float on the fuel in the fuel tank;
A plurality of detection means for detecting magnetic force generated from the magnet provided outside the fuel tank;
With
The plurality of detection means are provided at different positions in the direction in which the float moves as the fuel increases or decreases.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell which can grasp | ascertain the residual amount of fuel with a simple structure, without visually recognizing a fuel is realizable.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a first embodiment of the present invention will be described.
FIG. 1 is a cross-sectional view showing a fuel cell according to this embodiment.
FIG. 2 is a perspective view showing the column shown in FIG.
FIG. 3 is a cross-sectional view showing the column shown in FIG.
The fuel cell according to the present embodiment is, for example, a direct fuel cell that uses methanol as a fuel, and is built in a personal computer, for example, and replenished with fuel from the outside. In addition to methanol, for example, ethanol or an aqueous solution of saccharides such as glucose and sugar can be used as the fuel.

  As shown in FIG. 1, in the fuel cell 1 according to the present embodiment, a housing 2 made of, for example, a resin is provided, and a rectangular parallelepiped fuel tank 3 is provided inside the housing 2, for example. Yes. The fuel tank 3 is made of resin, for example, and no window is provided. The housing 2 is also not provided with a window. Methanol is held in the fuel tank 3 as a liquid fuel 50. The fuel tank 3 is fixedly installed with respect to the housing 2, and the fuel 50 is replenished in a timely manner from the outside.

  A float 4 is housed inside the fuel tank 3. The float 4 is formed by a magnet 5 and a resin outer shell 6 that encloses the magnet 5. The shape of the float 4 is, for example, a spherical shape, and the diameter thereof is smaller than the shortest distance among the distances between the inner walls of the fuel tank 3 facing each other. The float 4 is not fixed to the fuel tank 3, and the specific gravity of the entire float 4 is smaller than the specific gravity of the fuel 50. As a result, the float 4 floats on the fuel 50 and is positioned on the liquid level 51 of the fuel 50. That is, the float 4 moves in the vertical direction in accordance with the increase / decrease of the fuel 50.

  Further, a rectangular parallelepiped recess 2a is formed on the side of the fuel tank 3 in the housing 2, and a plurality of column bodies 8 are provided in parallel to each other in the recess 2a. The shape of the column 8 is a cylindrical shape, and is rotatably supported by the inner wall of the recess 2a. The rotation axis extends in the horizontal direction. Thereby, the columnar body 8 is fixedly arranged at different positions along the vertical direction. The diameter of the column 8 is, for example, 5 mm. The column 8 is exposed on the outer surface of the fuel cell 1, and the display portion 10 is constituted by the recess 2 a and the column 8.

  As shown in FIGS. 1, 2, and 3, the outer peripheral surface of the column 8 is color-coded into a plurality of regions along the circumferential direction. That is, each region has a stripe shape extending in the axial direction of the column 8. For example, in the specific example shown in FIG. 1, the outer peripheral surface of the column 8 is color-coded into two regions, a narrow region corresponding to a fan-shaped arc with a central angle of 90 degrees, and a fan-shaped with a central angle of 270 degrees. It is divided into a wide area corresponding to the arc. In the specific examples shown in FIGS. 2 and 3, the outer peripheral surface of the column 8 is equally divided into four regions, which are a green region 8G, a red region 8R, a blue region 8B, and a red region. The region 8R is arranged in this order along the circumferential direction. That is, the green region 8G and the blue region 8B are located at positions facing each other across the central axis 8a, and the two red regions 8R are located at positions facing each other across the central axis 8a. is there.

  In addition, a magnetic body portion 9 made of a magnetic material such as iron, cobalt, or nickel is provided inside the column body 8. The center of gravity of the magnetic body portion 9 is disposed at a position deviating from the central axis 8 a of the column body 8. For example, in the specific example shown in FIG. 1, the magnetic body portion 9 is disposed on the narrow region side as viewed from the central axis of the column body 8. Further, in the specific examples shown in FIGS. 2 and 3, the magnetic body portion 9 is disposed on the green region 8 </ b> G side when viewed from the central axis 8 a of the column body 8. And the part other than the magnetic body part 9 in the column 8 is formed of a material whose specific gravity is smaller than that of the magnetic body, for example, resin. For this reason, the center of gravity of the entire column body 8 is also at a position deviated from the central axis 8a. For example, in the example shown in FIG. 1, the center of gravity is on the narrow region side as viewed from the central axis, and in the examples shown in FIGS. It is on the green region 8G side when viewed from 8a.

  Furthermore, a power generation unit (not shown) is provided in the housing 2. The power generation unit generates electric power by reacting methanol supplied from the fuel tank 3 with oxygen. The electric power generated by the power generation unit is supplied to the outside via a terminal (not shown) provided on the outer surface of the housing 2.

Next, the operation of this embodiment will be described.
FIGS. 4A and 4B are views showing the influence of the distance between the float and the column on the posture of the column in the fuel cell according to the present embodiment, and FIG. 4A shows the float and the column. The case where the body is approaching is shown, and (b) shows the case where the float is separated from the column. In FIG. 4, for convenience, four regions that are color-coded on the outer peripheral surface of the column 8 are shown as fan-shaped regions. The same applies to FIG. Further, in FIG. 4, for convenience of explanation, only one specific one of the plurality of columnar bodies 8 provided in the vertical direction is shown.
FIG. 5 is a front view showing the display unit of the fuel cell according to the present embodiment.

  As shown in FIG. 3, if no magnetic force acts on the magnetic body portion 9 of the column body 8, the magnetic body portion 9 is positioned immediately below the central axis 8 a due to the weight of the magnetic body portion 9. Keep such a posture. At this time, of the outer peripheral surface of the column 8, the green region 8 </ b> G faces downward, and thus the red region 8 </ b> R faces the outer surface side of the fuel cell 1.

However, actually, a magnetic force is applied to the magnetic body portion 9 of the column 8 by the magnet 5 of the float 4. Further, the magnitude of the magnetic force differs depending on the position where the column 8 is disposed.
As shown in FIG. 1, when the fuel 50 is injected into the fuel tank 3 of the fuel cell 1, the float 4 is given buoyancy by the fuel 50 and floats on the liquid level 51. Thereby, the column body 8 located at the same height as the liquid surface 51 among the plurality of column bodies 8 has a relatively short distance from the float 4. As a result, as shown in FIG. 4A, the magnetic force acting between the magnet 5 of the float 4 and the magnetic body portion 9 of the column body 8 becomes stronger than the gravity acting on the magnetic body portion 9, and the column The body 8 rotates and the magnetic body portion 9 is positioned on the float 4 side as viewed from the central axis 8a. Thereby, in the outer peripheral surface of the column 8, the green region 8 </ b> G faces the fuel tank 3 side, and thus the blue region 8 </ b> B facing the green region 8 </ b> G faces the outer surface side of the fuel cell 1.

On the other hand, the column body 8 not positioned at the same height as the liquid surface 51 has a relatively long distance from the float 4. For this reason, as shown in FIG. 4B, the magnetic force acting between the magnet 5 and the magnetic body portion 9 is weaker than the gravity acting on the magnetic body portion 9. As a result, in the outer peripheral surface of the column 8, the green region 8 </ b> G faces downward, and thus the red region 8 </ b> R faces the outer surface side of the fuel cell 1.
Thus, the column 8 detects the magnetic force generated from the magnet 5 and changes its posture.

Accordingly, as shown in FIG. 5, when the display unit 10 is viewed from the outside of the fuel cell 1, the magnetic force acting on the magnetic body unit 9 is close to the liquid level 51 (see FIG. 1) of the fuel 50 and greater than the gravity. In the region 11, the blue region 8B of the column 8 is visible. Further, in a region 12 far from the liquid surface 51 and having a magnetic force acting on the magnetic body portion 9 smaller than gravity, a red region 8R of the column 8 can be seen. Thereby, the user can know the position of the liquid level 51 and grasp the remaining amount of the fuel 50 by visually recognizing the position of the blue region 11. In FIG. 5, hatched lines are drawn in the blue region 8 </ b> B of the column 8 for easy viewing of the drawing.
Similarly, in the example shown in FIG. 1, in the column body 8 far from the float 4, the wide region faces the outer surface side of the fuel cell 1, and in the column body 8 close to the float 4, the narrow region faces the outer surface side.

Next, the effect of this embodiment will be described.
According to this embodiment, the user can grasp the remaining amount of the fuel 50 by looking at the column body 8 without directly viewing the fuel 50. Therefore, even when a transparent liquid such as methanol is used as the fuel 50, the remaining amount of the fuel 50 can be easily grasped. In addition, since there is no need to provide a viewing window in the fuel tank 3 and the housing 2 and it is not necessary to provide a viewing window in the electronic device on which the fuel cell 1 is mounted, the design of the fuel cell and the electronic device and the degree of freedom of design are increased. large.

  Further, according to the present embodiment, the fuel 4 is provided with the float 4 having the magnet 5 in the fuel tank 3, and the remaining fuel can be obtained with a simple configuration in which the plurality of pillars 8 are rotatably attached to the housing 2. The amount can be displayed. For this reason, the cost of the fuel cell is not significantly increased. Further, since the remaining amount of fuel is displayed by rotating the plurality of pillars 8 at a position fixed with respect to the fuel tank 3, it is not necessary to provide a mechanism for moving the fuel cell 1 greatly. For this reason, there are few mechanical failures. Furthermore, since the fuel cell 1 is not provided with an electrical mechanism, no electric power is required to display the remaining amount of fuel, and no electrical failure occurs.

  Furthermore, according to the present embodiment, since the outer diameter of the float 4 is made smaller than the shortest distance among the distances between the mutually opposing inner walls of the fuel tank 3, the float 4 is inside the fuel tank 3. It can be prevented from being caught by.

  In the present embodiment, a reference for recognizing the position of the boundary between the region 11 and the region 12 in the vicinity of the display unit 10 on the outer surface of the housing 2, that is, a position where the user can view the display unit 10 at the same time. For example, a scale and numbers may be displayed. Accordingly, the user can accurately grasp the remaining amount of the fuel 50 by making the position of the boundary between the region 11 and the region 12 correspond to the reference such as the scale and the number.

  Moreover, the color of the outer peripheral surface of the column 8 is not limited to the above specific example, and any color may be used. It is preferable to use a color that is easy to identify the position of the liquid level and that has excellent design properties. Further, for example, in the several columnar bodies 8 located at the lower part of the display unit 10, other color regions may be set instead of the blue region 8B. Thereby, when the remaining amount of fuel is reduced, another color area appears, and a warning can be given to the user.

  Furthermore, in this embodiment, although the example which made the shape of the fuel tank 3 rectangular solid and the shape of the float 4 spherical was shown, this invention is not limited to this. For example, the fuel tank may have a cylindrical shape, and the float may have an ellipsoidal shape. However, in this case, it is preferable to make the maximum outer diameter of the float smaller than the minimum inner diameter of the fuel tank. Thereby, it is possible to prevent the float from being caught inside the fuel tank.

Furthermore, in the present embodiment, an example in which the fuel tank 3 is fixedly installed with respect to the housing 2 has been shown, but the present invention is not limited to this, and the fuel tank 3 is mounted on the housing 2. Alternatively, it may be a cartridge-type fuel tank that is detachably provided. Also in this case, when the fuel cell 1 is used, the fuel tank 3 is fixed with respect to the housing 2, so that the column body 8 rotates at a position fixed with respect to the fuel tank 3. .
In the present embodiment, the same effect can be obtained even if a columnar body such as a prismatic column (a quadrangular column, a hexagonal center, etc.) is shown in a freely rotating manner instead of the columnar column 8. It is included in the scope of the invention. Further, instead of the column body 8, for example, a spherical member may be provided so as to be rotatable.

Next, a modification of the first embodiment will be described.
FIG. 6 is a cross-sectional view showing a column of a fuel cell according to this modification.
In this modification, a column 18 is provided instead of the column 8 in the first embodiment described above. A magnet 19 is embedded inside the column 18, and a portion other than the magnet 19 in the column 18 is formed of, for example, a resin. The center of gravity of the magnet 19 coincides with, for example, the central axis 18a of the column 18 and is arranged, for example, so that the blue region 18B side is the S pole and the green region 18G side is the N pole. The configuration other than the above in the present modification is the same as that in the first embodiment.

Hereinafter, the operation of this modification will be described.
FIGS. 7A and 7B are cross-sectional views showing a display unit of a fuel cell according to this modification. FIG. 7A shows a case where the float and the column are separated from each other, and FIG. And the case where the column is approaching. In FIG. 7, for convenience, four areas that are color-coded on the outer peripheral surface of the column 18 are shown as fan-shaped areas. Further, in FIG. 7, components other than the float 4 and the column body 18 are omitted in order to simplify the drawing.

  As shown in FIG. 7A, when the column body 18 is separated from the float 4 (not shown), the posture of the column body 18 is restrained by the magnetic force between the column bodies 18, and two adjacent columns The body 18 takes a posture such that the S pole side of one column 18 and the N pole side of the other column 18 are close to each other. For this reason, for example, when the S pole side of a certain column 18 faces upward and the N pole side faces downward, the N pole side of the column 18 positioned on the upper side of the column 18 faces downward and is positioned on the lower side. The S pole side of the column 18 faces upward. By the same operation, the S pole side is upward and the N pole side is downward in all the column bodies 18. That is, all the column bodies 18 take the same posture. As a result, in all the column bodies 18, the red region 18R faces the outer surface of the display unit.

  On the other hand, as shown in FIG. 7B, when the float 4 and the column 18 are approaching, the S pole side or the N pole side of the column 18 is pulled by the float 4, and the outer peripheral surface of the column 18 Among them, the blue region 18B or the green region 18G faces the fuel tank 3, and the green region 18G or the blue region 18B faces the outer surface side of the fuel cell.

  As a result, when the display unit is viewed from the outside of the fuel cell, the magnetic force that the magnet 19 receives from the magnet 5 provided on the float 4 is about the column 18 near the liquid surface 51 (see FIG. 1) of the fuel 50. Since it is larger than the magnetic force received from the magnet 19 of the adjacent column 18, the green region 18 </ b> G or the blue region 18 </ b> B can be seen. On the other hand, since the magnetic force that the magnet 19 receives from the magnet 5 provided on the float 4 is smaller than the magnetic force received from the magnet 19 of the adjacent column 18 for the column 18 far from the liquid level 51, the red region 18 </ b> R. Can be seen. Thereby, the user can know the position of the liquid level 51 and grasp the remaining amount of the fuel 50 by looking at the column 18.

  Operations and effects other than those described above in the present modification are the same as those in the first embodiment described above. In this modification, the region located on the south pole side of the magnet 19 in the outer peripheral surface of the column 18 is a blue region 18B, and the region located on the north pole side is a green region 18G. Although shown, this invention is not limited to this, The area | region located in the S pole side of the magnet 19 and the area | region located in the N pole side among the outer peripheral surfaces of the column 18 may be colored with the same color. .

Next, a second embodiment of the present invention will be described.
FIG. 8 is a cross-sectional view showing the fuel cell according to the present embodiment.
FIG. 9 is a cross-sectional view showing the float in the present embodiment.
In the fuel cell 21 according to the present embodiment, a housing 22 that forms an outer shell of the fuel cell 21 is provided, and a fuel tank 3 is provided inside the housing 22. A float 24 is housed inside the fuel tank 3.

The float 24 is provided with a hollow outer shell 26 inside, and a magnet 25 is provided inside the outer shell 26. The outer shell 26 is made of, for example, resin. The magnet 25 is connected to the inner surface of the outer shell 26 by a plurality of, for example, two springs 27. Thereby, the magnet 25 vibrates in a certain space in the outer shell 26. That is, the spring 27 functions as an elastic body that supports the magnet 25 against the inner surface of the outer shell 26.
The shape of the float 24 is, for example, a spherical shape, and the diameter thereof is smaller than the shortest distance among the distances between the mutually opposing inner walls of the fuel tank 3. The float 24 is not fixed to the fuel tank 3, and the specific gravity of the entire float 24 is smaller than the specific gravity of the fuel 50. As a result, the float 24 floats on the fuel 50.

  In addition, unlike the first embodiment described above, in this embodiment, the housing 22 is not provided with a recess. On the other hand, a coil 28 is provided inside the housing 22 so as to wind around the fuel tank 3, and both ends of the coil 28 are connected to a current sensor 29. A plurality of induced current detection means including the coil 28 and the current sensor 29 are provided along the longitudinal direction of the fuel tank 3, that is, the vertical direction. For example, the height of the fuel tank is 8 centimeters, and five induced current detection means are provided. Each induced current detection means is electrically independent from each other. And the detection result by each current sensor 29 is displayed by the display means (not shown) attached to the housing | casing 22. As shown in FIG.

Next, the operation of this embodiment will be described.
When the electronic device mounted with the fuel cell 21 is used or transported, when the electronic device is moved, the fuel 50 in the fuel tank 3 shakes and the liquid level 51 moves up and down. Vibrates up and down. Then, the action of the spring 27 amplifies the vibration of the magnet 25 in the float 24, and the magnet 25 vibrates with a larger amplitude than that of the outer shell 26. As a result, since the magnet 25 moves in the coil 28 of the induced current detection means, an induced current of, for example, milliampere order flows through the coil 28, and this induced current is detected by the current sensor 29. The detection result is displayed by the display means, so that the user can know the remaining amount of the fuel 50.

Next, the effect of this embodiment will be described.
According to this embodiment, the user can grasp the remaining amount of the fuel 50 without directly viewing the fuel 50. Therefore, even when a transparent liquid such as methanol is used as the fuel 50, the remaining amount of the fuel 50 can be easily grasped. In addition, since it is not necessary to provide a viewing window in the fuel tank 3 and the housing 22, and it is not necessary to provide a viewing window in the electronic device on which the fuel cell 21 is mounted, the design of the fuel cell and the electronic device and the degree of freedom of design are increased. large.

  Further, according to the present embodiment, the arrangement position of the fuel tank 3 is not restricted as compared with the first embodiment described above. For example, the fuel tank 3 can be arranged at a position away from the housing 22 inside the housing 22. For this reason, the freedom degree of design of a fuel cell improves further.

  Furthermore, according to the present embodiment, a simple structure is provided in which a float 24 is provided in the fuel tank 3, a plurality of coils 28 are provided so as to wind the fuel tank 3, and a current sensor is connected to the coil 28. The remaining amount of fuel can be displayed. For this reason, the cost of the fuel cell can be suppressed. In addition, since a plurality of induced current detection means operate at positions fixed to the fuel tank 3 to display the remaining amount of fuel, there is no need to provide a mechanical mechanism outside the fuel tank 3, No mechanical failure occurs.

  Furthermore, since the current sensor 29 detects the induced current flowing through the coil 28, it is not necessary to supply electric power to the induced current detecting means from the outside. For this reason, no electric power is required to display the remaining amount of fuel.

  Furthermore, according to the present embodiment, the outer diameter of the float 24 is made smaller than the shortest distance among the distances between the inner walls of the fuel tank 3 facing each other. It can be prevented from being caught inside.

  In the present embodiment, an example in which the induced current flowing in the coil 28 is detected by the current sensor 29 has been described. However, the present invention is not limited to this. For example, the induced electromotive force generated in the coil 28 by the voltage sensor. May be detected.

  The display means may simply display the detection result of each current sensor 29. Even in this case, the user can know the position of the liquid level 51 by knowing the position of the float 24 and can recognize the remaining amount of the fuel 50. However, the display means preferably displays the remaining amount of the fuel 50 quantitatively. Further, when the electronic device on which the fuel cell is mounted includes a display unit such as a display panel, the fuel cell is not provided with a display means, and the output signal of the current sensor 29 is input to the electronic device. Then, the remaining amount of the fuel 50 may be displayed on the display unit of the electronic device. In this case, the remaining operation time of the electronic device may be calculated from the remaining amount of the fuel 50 and displayed.

  Furthermore, in this embodiment, the example in which the fuel tank 3 is fixedly installed with respect to the housing 22 has been shown. However, the present invention is not limited to this, and the fuel tank 3 is mounted on the housing 22. It may be a cartridge type fuel tank that is detachably provided. Also in this case, when the fuel cell 21 is used, the fuel tank 3 is fixed with respect to the housing 22, so that the induced current detection means operates at a position fixed with respect to the fuel tank 3. Become.

  Furthermore, when the electronic device equipped with the fuel cell 1 is not moving, the float 24 also does not move, and no induced current flows through the coil 28. In this case, the user wants to know the remaining amount of the fuel 50. Sometimes, the electronic device or the fuel cell may be lightly shaken. As a result, the liquid level 51 of the fuel 50 sways and an induced current flows through the coil 28, so that the display means can display the remaining amount of the fuel 50.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to these embodiment. For example, a plurality of cells that are visible from the outside may be provided along the outer surface of the fuel cell housing, and a magnetic fluid or iron sand may be enclosed in each cell. Thereby, the position of a float can be pinpointed by the behavior of magnetic fluid or sand iron. At this time, magnetic fluid or iron sand may be colored. Further, the material, size, shape, arrangement relationship, etc. of each element constituting the fuel cell are within the scope of the present invention as long as they include the gist of the present invention even if they are appropriately modified by those skilled in the art. Is included. Further, the fuel is not limited to methanol, and the present invention can be suitably applied to any fuel cell that uses liquid fuel.

1 is a cross-sectional view showing a fuel cell according to a first embodiment of the present invention. It is a perspective view which shows the column body shown in FIG. It is sectional drawing which shows the column body shown in FIG. (A) And (b) is a figure which shows the influence which the distance between a float and a pillar body has on the attitude | position of a pillar body in the fuel cell which concerns on this embodiment, (a) is a float and a pillar body. (B) shows the case where the float and the column are separated. It is a front view which shows the display part of the fuel cell which concerns on this embodiment. It is sectional drawing which shows the column of the fuel cell which concerns on the modification of 1st Embodiment. (A) And (b) is sectional drawing which shows the display part of the fuel cell which concerns on this modification, (a) shows the case where the float and the column body are separated, (b) shows the float and the column. Indicates the case where the body is approaching. It is sectional drawing which shows the fuel cell which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the float in this embodiment.

Explanation of symbols

1, 21 Fuel cell, 2, 22 Case, 2a Recessed part, 3 Fuel tank, 4, 24 Float, 5, 25 Magnet, 6, 26 Outer shell, 8, 18 Column, 8a, 18a Central axis, 8B, 18B Blue region, 8G, 18G Green region, 8R, 18R Red region, 9 Magnetic body portion, 10 Display portion, 11, 12 region, 19 Magnet, 27 Spring, 28 Coil, 29 Current sensor, 50 Fuel, 51 Liquid surface

Claims (5)

A fuel tank that holds the fuel;
A float provided with a magnet to float on the fuel in the fuel tank;
A plurality of detection means for detecting magnetic force generated from the magnet provided outside the fuel tank;
With
The plurality of detection means are arranged at different positions in the direction in which the float moves as the fuel increases or decreases.   The detection means is a column body having a member made of a magnetic body and rotatably supported, and the rotation axis of the column body extends in a direction intersecting the direction in which the float moves, 2. The fuel cell according to claim 1, wherein the center of gravity of the column body and the center of gravity of the member are located at positions deviated from the rotation axis of the column body.   The detection means is a column having a magnet and rotatably supported, and the rotation axis of the column extends in a direction intersecting with a direction in which the float moves. Item 2. The fuel cell according to Item 1.   4. The fuel cell according to claim 2, wherein an outer peripheral surface of the column body is color-coded into a plurality of regions along a circumferential direction thereof. The detection means includes
A coil provided to wind around the fuel tank;
A sensor for detecting a current flowing in the coil or an electromotive force generated in the coil;
The fuel cell according to claim 1, comprising:

Images