JP2006284258A - Liquid level detection sensor and liquid container having liquid level detection sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid level detection sensor capable of improving inferiority in drainage of a liquid inside a cylindrical float case due to the influence of a capillary phenomenon and surface tension, and detecting the level in height of the liquid accurately and reliably. <P>SOLUTION: The liquid level detection sensor for detecting the level in height of the liquid inside a liquid container is composed by providing in its one end, a float equipped with a portion to be detected, and a detecting means for detecting the position of the portion to be detected which is equipped in the float, and moreover by having a cylindrical float case for housing the float inside. The float is housed in such a way as to be movable vertically along the inner wall surface of the cylindrical float case with the variations in the liquid level, and by detecting the state of vertical movement of the portion to be detected which is provided in the float, the liquid level detection sensor detects the level in height of the liquid, and the liquid level detection sensor has slits in the side face of the cylindrical float case. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid level detection sensor and a liquid container having a liquid level detection sensor.

  As a device for detecting the level of the liquid level in a liquid container (for example, a fuel tank, etc.), as the liquid level rises and falls, the float with the detected object moves up and down along the guide, There is known an apparatus for detecting the position of the detected object by a detecting means at the lower end and confirming the level of the liquid level. (For example, Patent Document 1)

  5A and 5B show a conventional liquid level detection sensor, where FIG. 5A is a perspective view and FIG. 5B is a cross-sectional view. A float 2 provided with a magnet 3 is accommodated in a cylindrical float case 1 having a Hall element 4 at one end. The liquid level detection sensor of the said structure is installed in the upper end part or lower end part in a liquid container, and monitors the position (high / low) of the float 2 which moves up and down along the inner wall surface of the cylindrical float case 1 with the fluctuation | variation of a liquid level. This is used to confirm the level of the liquid level.

  Specifically, the float is detected by detecting the strength of the magnetic force generated by the positional relationship between the magnet 3 provided in the float 2 and the Hall element 4 provided in the cylindrical float case 1 by the output voltage of the Hall element 4. Recognize the position. As the liquid level rises, the magnet 3 rises at the same time as the float 2 and the magnetic force applied to the Hall element 4 increases and the output voltage increases. On the contrary, as the liquid level falls, the magnet 3 descends simultaneously with the float 2 and the magnetic force applied to the Hall element 4 is weakened, so that the output voltage is lowered. By detecting this output voltage, the level of the liquid level is recognized.

  A convex portion 1 ′ provided at the end of the cylindrical float case 1 is a drop-off preventing member provided so that the float 2 does not come out of the cylindrical float case 1.

When the liquid level detection sensor is installed at the upper end in the liquid container, the float 2 rises when the liquid level is high, that is, when the liquid amount is full, and descends when the liquid amount decreases. The movement of the float 2 is detected by the Hall element 4, and the liquid level in the liquid container and the remaining amount of liquid are recognized.
JP 2004-219143 A

  The above-described conventional liquid level detection sensor is desired to be used as a means for detecting the remaining amount of liquid in a container containing a liquid such as methanol, which is currently used as a fuel cell. This fuel cell is being further miniaturized with the aim of being mounted on all portable electronic devices, and naturally the liquid level detection sensor expected as a means for detecting the remaining amount of liquid is also required to be downsized. It is.

  Although it is possible to simply downsize the liquid level detection sensor according to the conventional configuration, the following problems arise as functional malfunctions due to downsizing.

  When the liquid enters the cylindrical float case having a narrow cylindrical inner diameter along with the downsizing, the liquid inside the cylindrical float case becomes poor due to the capillary action and the surface tension. Therefore, the liquid stays inside the cylindrical float case, and the float stays at a certain position regardless of the rise and fall of the surrounding liquid, and the state where the up and down operation is not continued continues. As a result, there is a problem that an accurate liquid level cannot be detected.

  In addition, the reason why the liquid that has entered the inside of the cylindrical float case is poorly drained is that a protrusion for preventing the float from falling off is provided. This is necessary for the liquid level detection sensor having the above-described configuration. It is a simple member and cannot simply be lost.

  In view of the above-mentioned problems, the present invention improves the liquid breakage of the liquid inside the cylindrical float case caused by the effect of capillary action and surface tension, and can detect the liquid level level accurately and reliably. It is intended to provide a sensor.

  In the liquid level detection sensor for detecting the level of the liquid level in the liquid container, the float having the detected portion and the detecting means for detecting the position of the detected portion provided in the float are provided at one end. A cylindrical float case that accommodates the float therein, and the float is accommodated so as to move up and down along the inner wall surface of the float case as the liquid level changes. A liquid level detection sensor for detecting a level of a liquid level by detecting a position of a detection unit by a detection unit provided in the cylindrical float case, and a slit is provided on a side surface of the cylindrical float case A liquid level detection sensor is used.

  Furthermore, the liquid level detection sensor is configured such that the slit extends in parallel with the central axis direction of the cylindrical float case and extends to the other end where the detection unit is not provided.

  By providing a slit as described above, a large inflow / outlet of the liquid can be secured, so that even if it is downsized, the liquid runs out better and the problem that the float continues to stay in the cylindrical float case is improved. The surface level can be detected.

  Further, a liquid level detection sensor provided with a drop-off preventing member for preventing the float from falling out of the cylindrical float case at the other end of the cylindrical float case where the detecting means is not provided. To do.

  Since the cylindrical float case is provided with a slit and a float drop-off preventing member is provided, it is possible to improve liquid drainage and prevent the float from falling off.

  Further, in the liquid level detection sensor for detecting the liquid level in the liquid container, a float having a detected portion and a substrate on which detection means for detecting the position of the detected portion provided in the float is placed. A plurality of rod-like pins are planted and arranged on the peripheral edge of the substrate, and the float is housed in a space surrounded by the rod-like pins, and the float serves as a guide as the liquid level changes. The liquid level detection sensor is housed so as to be movable up and down, and detects the level of the liquid level by detecting the position of the detected portion provided in the float by the detecting means placed on the substrate.

  In the said structure, a liquid inflow / outlet can be ensured still larger by using a rod-shaped pin. In addition, complicated processing can be omitted and the part cost can be reduced.

  Furthermore, a liquid level detection sensor is provided in which a free end portion of the pin is provided with a drop-off preventing member that prevents the float from falling out of the space surrounded by the rod-shaped pin.

  In the above configuration, since the rod-like pin is used and the float-off preventing member is provided on the rod-like pin, the liquid breakage is further improved and the float can be prevented from falling off.

  Furthermore, the detection means is a magnetic detection element, and the detected portion is a liquid level detection sensor that is a magnet.

  The magnetic detection element is a Hall element, and the change in the magnetic field due to the separation / contact of the magnetic material provided on the float is detected by the strength of the output voltage due to the Hall effect, whereby the level of the liquid level can be easily detected.

  A liquid container having the liquid level detection sensor, wherein the liquid level detection sensor has a liquid level detection sensor installed on the upper part of the inner wall of the liquid container or on the lower part of the inner wall.

  The liquid container includes a liquid level detection sensor provided with a convex portion that regulates the position of the float of the liquid level detection sensor on the other inner wall that faces the inner wall where the liquid level detection sensor is installed.

  Since the protrusion for regulating the float position is provided on the liquid container side to prevent the float from falling off, it is not necessary to provide a drop-off preventing member on the cylindrical float case or the rod-like pin, and the liquid breakage is further improved.

  A structure in which a slit is provided on a side surface of a cylindrical float case for storing a float, and a structure in which a float is stored in a space surrounded by a plurality of rod-shaped pins allows the liquid to move in the vertical movement range of the float. Since a large inflow / outlet can be ensured, even if the device is reduced in size, the liquid runs out better and an accurate liquid level can be detected.

  A structure in which a slit is provided on the side surface of a cylindrical float case for storing a float, and a structure in which a float is stored in a space surrounded by a plurality of rod-shaped pins. Secure.

  1A and 1B are diagrams showing an embodiment of a liquid level detection sensor according to the present invention, in which FIG. 1A is a perspective view and FIG. 1B is a top view. On the upper part of the cylindrical float case 1, a hall element 4 as a detecting means is provided. A slit 1 a extending in parallel to the central axis of the cylindrical float case 1 and extending to the lower end of the cylindrical float case 1 is provided on the side surface of the cylindrical float case 1. It is preferable to ensure the slit width as wide as possible. Reference numeral 2 denotes a float, which is arranged in the cylindrical float case 1 so as to move up and down along the inner wall surface of the cylindrical float case 1. A convex portion 1 ′ for preventing the float 2 from falling off is provided at the lower end of the cylindrical float case 1. The convex portion 1 'projects toward the axial center of the cylindrical float case. A magnet 3 that is a detected portion is provided on the upper end surface of the float 2, and the upper surface of the float 2 is tapered so that the liquid can easily flow downward.

  When the float 2 is lowered as the liquid level is lowered, the magnet 3 is separated from the Hall element 4 at the same time, so that the output voltage from the output terminal 5 provided on the Hall element 4 is lowered due to the decrease of the magnetic force on the Hall element 4. Surface degradation can be detected. On the contrary, when the liquid level rises, the magnet 3 approaches the Hall element 4, and the rise in the liquid level can be detected by increasing the output voltage, as in the prior art.

  In the present invention, since the slit 1a is provided as in the above configuration, the liquid inflow / outlet can be secured wider than the conventional liquid level detection sensor of FIG. 5, so that the liquid level detection sensor can be downsized. The problem that the float 2 continues to stay in the cylindrical float case 1 due to capillary action or surface tension can be improved despite the surrounding liquid level being lowered.

  FIG. 2 is a perspective view showing another embodiment of the liquid level detection sensor of the present invention. In this embodiment, unlike the liquid level sensor of the first embodiment, the slit shape extending to the lower end of the side surface of the cylindrical float case 1 is not provided, but the slit 1b is partially provided only on the side surface. According to this configuration, it is possible to improve the drainage of the liquid and to have a structure with good rigidity. Moreover, although not shown in figure, the convex part for preventing dropping of the float 2 is provided in the lower end part of the cylindrical float case 1 like Example 1. FIG.

  3A and 3B are diagrams showing another embodiment of the liquid level detection sensor of the present invention, where FIG. 3A is a front view and FIG. 3B is a top view. Hall elements 4 are provided on the upper surface of the substrate 7, and four rod-like pins 6 are arranged on the lower surface so as to surround the float 2 with the magnet 3 on the lower surface. A cylindrical member 6 ′ for preventing the float 2 from falling off is inserted and fixed at the lower end of the rod-like pin 6. As a member for preventing the float 2 from falling off, for example, a rod-shaped pin may be a thin metal wire, and a lower end portion of the rod-shaped pin may be bent inward.

  In the above configuration, the float 2 moves up and down with the rod-shaped pin 6 as a guide as the liquid level changes, and the level of the liquid level can be detected by detecting the voltage output of the Hall element 4. Moreover, since it can reduce the contact area of the said float 2 and the rod-shaped pin 6 by setting it as the rod-shaped pin 6, followability and responsiveness can be improved. Furthermore, according to this configuration, complicated processing can be omitted and the cost of parts can be reduced.

  The liquid level detection sensors described in the first, second, and third embodiments are used by being installed on the inner wall portion of the liquid container, but the installation position may be any of the upper portion of the inner wall and the lower portion of the inner wall.

  FIG. 4 is a partial cross-sectional view showing an embodiment of a liquid container having a liquid level detection sensor of the present invention. A hall element 4 is provided at a lower portion of the cylindrical float case 1 provided with a slit 1a extending to the lower end. The float 2 includes a magnet 3 at a lower portion, and a lower surface side is formed in a tapered shape. The float 2 moves up and down along the inner wall surface of the cylindrical float case 1 as the liquid level fluctuates, and constitutes a liquid level detection sensor in which the Hall element 4 detects the strength of the magnetic force. In the present embodiment, the liquid level detection sensor having the above-described configuration is installed on the lower side of the inner wall of the liquid container 9.

  When the liquid inside the liquid container 9 increases, the float 2 floats. However, a stopper 8 is provided on the upper part of the liquid container 9 to prevent the float 2 from dropping from the cylindrical float case 1 and restrict the position of the float 2. is doing.

  In the configuration of this embodiment, as the liquid level rises, the magnet 3 moves away from the Hall element 4 at the same time as the float 2, so that the output voltage decreases. An increase in the liquid level 10 can be detected by a decrease in the output voltage of the Hall element 4. Conversely, a decrease in the liquid level 10 can be detected by an increase in the output voltage. According to this configuration, since the stopper 8 for preventing the float 2 from dropping is provided in the liquid container 9, it is not necessary to provide a drop-off preventing member in the cylindrical float case 1 serving as a guide. Can be improved.

  The liquid level detection sensor may be turned upside down and installed on the upper part of the inner wall of the liquid container. In this case, the determination setting of the level of the liquid level by increasing or decreasing the output voltage of the Hall element may be changed. In any case, it can function as a liquid level detection sensor that detects an accurate level of the liquid level.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows one Example of the liquid level detection sensor of this invention, (a) is a perspective view, (b) is a top view (Example 1). It is a figure which shows the other Example of the liquid level detection sensor of this invention, and is a perspective view (Example 2). It is a figure which shows the other Example of the liquid level detection sensor of this invention, (a) is a front view, (b) is a top view (Example 3). The figure which shows one Example of the liquid container which has the liquid level detection sensor of this invention, and is a partial cross section figure (Example 4) In the conventional liquid level detection sensor, (a) is a perspective view, (b) is a sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical float case 1a Slit 1b Slit 1 'Convex part 2 Float 3 Magnet 4 Hall element 5 Hall element output terminal 6 Rod-shaped pin 6' Cylindrical member 7 Substrate 8 Stopper 9 Liquid container 10 Liquid surface

Claims (8)

In the liquid level detection sensor that detects the level of the liquid level in the liquid container,
A float having a detected portion;
It comprises a cylindrical float case that has a detecting means for detecting the position of the detected portion provided in the float at one end and accommodates the float inside,
The float is housed so as to move up and down along the inner wall surface of the cylindrical float case as the liquid level changes, and the detection means provided in the cylindrical float case is provided with the position of the detected portion provided in the float. A liquid level detection sensor that detects the level of the liquid level by detecting,
A liquid level detection sensor, wherein a slit is provided on a side surface of the cylindrical float case.   2. The liquid level detection sensor according to claim 1, wherein the slit extends in parallel with the central axis direction of the cylindrical float case and extends to the other end portion where the detection means is not provided.   The drop-off preventing member for preventing the float from falling out of the cylindrical float case is provided at the other end of the cylindrical float case where the detecting means is not provided. The liquid level detection sensor according to 1 or 2. In the liquid level detection sensor for detecting the liquid level in the liquid container,
A float having a detected portion;
A substrate on which detection means for detecting the position of the detected portion provided in the float is mounted;
A plurality of rod-like pins are planted and arranged on the peripheral edge of the substrate, and the float is housed in a space surrounded by the rod-like pins.
The float is housed so that it can move up and down with the rod-shaped pin as a guide as the liquid level changes, and the liquid level is detected by detecting the position of the detected portion provided in the float by the detecting means placed on the substrate. A liquid level detection sensor characterized by detecting a high and low level.   5. The liquid level detection sensor according to claim 4, wherein a drop-off preventing member is provided at a free end portion of the rod-shaped pin to prevent the float from falling out of a space surrounded by the rod-shaped pin.   The liquid level detection sensor according to claim 1, wherein the detection unit is a magnetic detection element, and the detected portion is a magnet. A liquid container having the liquid level detection sensor according to any one of claims 1 to 6,
A liquid container having a liquid level detection sensor, wherein the liquid level detection sensor is installed on an upper part of an inner wall of the liquid container or on a lower part of the inner wall.   A liquid container comprising the liquid level detection sensor according to any one of claims 1, 2, 4, and 6, wherein the liquid level detection sensor is installed on an inner wall upper part or an inner wall lower part of the liquid container, A liquid level detection sensor characterized in that a convex portion for regulating the position of the float of the liquid level detection sensor is provided on another inner wall portion facing the inner wall portion where the liquid level detection sensor is installed. Having liquid container.

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