JP2006284259A - Apparatus for detecting liquid level and liquid tank having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for detecting a liquid level having a few number of components parts in a liquid tank, capable of improving volume efficiency in the liquid tank, and excellent in the followability of a float to a liquid level, and also to provide a liquid tank having the same. <P>SOLUTION: The apparatus for detecting a liquid height level in the liquid tank comprises both a protrusion type float having a part to be detected and a holder having both a recession part to be fitted over a protrusion part of the float for restricting the direction of movement of the float and a detection means for detecting the position of the float. The position of the float floating with variations of the liquid level in the liquid tank and the part to be detected provided for the float are detected by the detection means of the holder to detect the liquid height level in the liquid level detection apparatus. The holder does not protrude to inside an inner wall surface of the liquid tank in the liquid level detection apparatus. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid level detection device for detecting a liquid level in a liquid tank and a liquid tank having the liquid level detection device.

  As a liquid level detection device that detects the level of the liquid level in the liquid tank, a configuration as disclosed in Patent Document 1 is known.

  FIG. 5 is a cross-sectional view showing a conventional liquid level detection device. The liquid is composed of a guide pipe 31 in the liquid tank 30, a float 32 that moves up and down following the liquid level of the liquid in the guide pipe 31, and a detector 33 that is connected to the float 32 and moves up and down in conjunction with the float 32. It is a surface detection device. The liquid level detection device recognizes the level of the liquid level in the liquid tank 30 by visually confirming the position of the detection unit 33 interlocked with the float 32 that moves up and down as the liquid level rises and falls. is there. (See Patent Document 1)

JP 2004-340635 A

  In the liquid level detection apparatus as described above, it is necessary to provide a holding mechanism such as a pipe for guiding the movement direction of the float in the liquid tank so as to be immersed in the liquid. In such a configuration, the number of components in the liquid tank increases, the volume of liquid that can be stored in the liquid tank decreases, and the volumetric efficiency of the liquid tank decreases.

  In addition, since the float holding mechanism is immersed in the liquid, if the distance between the float and the holding mechanism is narrowed, the float is fixed to the holding mechanism due to surface tension, or the followability of the float to the liquid surface is deteriorated.

  The present invention solves such a problem, and there are few components in the liquid tank, the volume efficiency in the liquid tank is improved, and the liquid level detecting device and the liquid level with good followability to the liquid level of the float are provided. It is an object to provide a liquid tank having a detection device.

In the liquid level detection device that detects the level of liquid level in the liquid tank,
A convex float having a portion to be detected, a holder fitted with the convex portion of the float, and a concave portion for restricting the movement direction of the float and a detecting means for detecting the position of the float,
Liquid level detection device for detecting the level of the liquid level by detecting the position of the float that floats with the fluctuation of the liquid level in the liquid tank by means of a detection means of the holder that detects the detected portion provided in the float The holder is a liquid level detection device that does not protrude inward from the inner wall surface of the liquid tank.

  It is assumed that the detected portion provided in the float is a magnet, and the detection means provided in the holder is a liquid level detection device that is a magnetic detection element.

  The to-be-detected part provided in the convex float is a mirror provided at the tip of the float, and the detection means provided in the holder is a light emitting / receiving element installed on the bottom of the concave recess of the holder The liquid level detection device is an optical displacement sensor provided with

  In the liquid level detection device, either one or both of a shoulder portion continuous with the convex portion of the float and a leading end portion of the concave portion of the holder are formed in a tapered shape.

  A liquid tank having the liquid level detection device, wherein a holder of the liquid level detection device is a liquid tank installed on an upper end side or a lower end side of the liquid tank.

  The liquid tank has a liquid level detection device in which the height of the float is longer than the distance between the tip of the holder recess and the inner wall surface of the liquid tank on the opposite side of the holder.

  The liquid tank includes a liquid level detection device in which the holder is integrally formed on the wall of the liquid tank.

  In the present invention, since the holder having the recess for regulating the movement direction of the float does not protrude inward from the inner wall surface of the liquid tank, the member for regulating the movement direction of the float is a substantial space in the liquid tank. The volumetric efficiency of the liquid that can be stored is improved.

  In addition, since the detected portion is configured by a magnet and the detection means provided in the holder is configured by a magnetic detection element to detect the liquid level, the detection accuracy is improved.

  In addition, since the convex part of the float is used as a mirror surface to be detected, and an optical displacement sensor equipped with a light receiving and emitting element as a detecting means is provided on the bottom of the concave part of the holder, the liquid level is detected at a high level. Will improve.

  In addition, since one or both of the shoulder portion continuous to the convex portion of the float and the concave tip portion of the holder are formed in a tapered shape, the gap between the opposing surfaces when the float and the holder approach each other Can be secured widely, and the sticking of the float to the holder due to surface tension and the deterioration of the followability of the float to the liquid surface can be prevented.

  In addition, since the holder having a recess for regulating the movement direction of the float is installed on the upper end side or the lower end side of the liquid tank, the liquid level detection device is configured so as not to protrude inside the inner wall surface of the liquid tank. Since the member for regulating the moving direction of the float does not exist in the substantial space in the liquid tank, a liquid tank with improved volumetric efficiency of the liquid that can be stored is obtained.

  Further, since the height of the float is longer than the distance between the tip of the holder recess and the inner wall surface of the liquid tank on the opposite side of the holder, the float is detached from the holder regardless of the presence or absence of liquid. There is no end.

  Further, since the holder is integrally formed on the wall of the liquid tank, a liquid tank having a liquid level detecting device with a small number of parts can be obtained.

  A convex float having a detected portion, a concave portion that fits the convex portion of the float and regulates the movement direction of the float, and a holder that has detection means for detecting the position of the float, A liquid level detection device that detects the level of the liquid level by detecting the position of the float that floats as the liquid level in the liquid tank fluctuates by means of the detection means of the holder. And the volume efficiency of the liquid which can be stored in the said liquid tank as the structure which the said holder does not protrude inside the inner wall face of the said liquid tank improves. The present invention will be described below with reference to FIGS.

  FIG. 1 is a cross-sectional view of a liquid level detecting device showing a first embodiment of the present invention, and is a view arranged in a liquid tank. In the first embodiment of the present invention shown in FIG. 1, a holder 13 is installed in an opening provided on the upper surface of the liquid tank 1 so as to keep the airtightness of the liquid tank 1. A Hall element 14 serving as a detecting means is attached to the outer surface side of the liquid tank of the holder 13. A recess 13 a is formed on the inner surface side of the liquid tank of the holder 13. The tip of the recess 13a of the holder 13 is in a position recessed from the inner wall surface of the liquid tank, and does not protrude inward from the inner wall surface of the liquid tank. In the liquid tank 1, a convex float 11 having a width smaller than the width of the portion disposed in the liquid tank 1 of the holder 13 is installed, and the convex portion 11a of the float is fitted with the concave portion 13a of the holder. Yes. With this configuration, the float 11 is guided by the concave portion 13a of the holder 13 and floats in a state where the moving direction is restricted. A magnet 12 that is a detected portion is fixed to the tip of the convex portion 11a of the float.

  FIG. 4 is a cross-sectional view showing the liquid level detection device and the liquid tank having the liquid level detection device of the present invention, and is a supplementary diagram showing the dimensional relationship among the liquid tank, the holder and the float. As shown in FIG. 4, the length L of the convex portion 11a of the float 11 is longer than the length K of the concave portion 13a of the holder, and the height H of the float 11 is equal to the tip of the concave portion 13a of the holder 13 and the holder. 13 is longer than the distance G from the inner wall of the liquid tank 1 on the opposite surface. According to this configuration, even when the float 11 is positioned on the bottom surface of the liquid tank 1, the tip of the convex portion 11a is in a state of being fitted in the concave portion 13a of the holder 13, so that the float 11 is detached from the holder. There is no.

  Next, the operation of the liquid level detection device according to the present invention will be described. When the liquid tank 1 is empty, the float 11 is grounded to the bottom surface of the liquid tank 1 in a state of being engaged with the holder 13. When liquid is injected into the liquid tank 1, the float 11 rises with the concave portion 13a of the holder 13 as a guide according to the height of the liquid surface. The float 11 is provided with a magnet 12 that is a detected portion, and the holder 13 is provided with a Hall element 14 that is a detection means. When the magnet 12 approaches the Hall element 14, Output voltage rises. By monitoring this change, an increase in the liquid level can be detected in this configuration. On the contrary, when the liquid level falls, the magnet 12 of the float 11 moves away from the Hall element 14, so that the drop in the liquid level is detected when the output voltage from the Hall element 14 decreases.

  The liquid level detection device having the above configuration is configured such that the tip of the concave portion 13a of the holder does not protrude to the inside of the inner wall surface of the liquid tank, so that the volumetric efficiency in the liquid tank is not reduced.

  In the present embodiment, the Hall element 14 serving as detection means is provided on the upper portion of the holder 13, but may be provided on a side portion of the holder 13.

  In this embodiment, the holder 13 is installed on the upper surface of the liquid tank 1. However, the holder 13 may be installed on the lower surface of the liquid tank 1, and the float 11 may be arranged in accordance with the holder 13. .

  FIG. 2 is a sectional view showing a second embodiment of the present invention. In the second embodiment shown in FIG. 2, the holder 13 is installed in an opening provided on the upper surface of the liquid tank 1 so as to maintain airtightness. A recess 13 a is formed on the inner surface side of the holder 13. At the bottom of the concave portion 13a of the holder 13, a light receiving / emitting surface of an optical displacement sensor 24 provided with a light receiving / emitting element as a detecting means is installed so as to maintain airtightness. The tip of the concave portion 13a of the holder 13 is in a position recessed from the inner wall surface of the liquid tank. In the liquid tank 1, a convex float 11 having a shorter width than a portion disposed in the liquid tank 1 of the holder 13 is installed, and the convex portion 11 a of the float 11 is fitted with the concave portion 13 a of the holder 13. Are arranged. The front end surface of the convex portion 11 a of the float 11 is a detected portion and is a mirror surface 22.

  As for the dimensional relationship of each member, the length L of the convex portion 11a of the float 11 is configured to be longer than the length K of the concave portion 13a of the holder 13 as shown in FIG. 4 described in the first embodiment. . The height H of the float 11 is longer than the distance G between the tip of the holder recess 13 a and the inner wall of the liquid tank 1 on the opposite surface of the holder 13.

  Next, the operation of the liquid level detection apparatus according to the second embodiment of the present invention will be described. When the liquid tank 1 is empty, the float 11 is in contact with the bottom surface of the liquid tank in a state of being fitted with the holder 13. When the liquid is injected into the liquid tank 1, the float 11 rises in a state of fitting with the holder 13 according to the height of the liquid level. Here, light (arrow in the figure) emitted from the light emitting element of the optical displacement sensor 24 is reflected by the mirror surface 22 provided at the tip of the convex portion 11a of the float 11, and the reflected light is reflected by the optical displacement. Light is received by the light receiving element of the sensor 24. Depending on the distance between the light emitting element of the optical displacement sensor 24 and the mirror surface 22 provided at the tip of the convex portion 11a of the float 11, the light quantity distribution of the reflected light in the light receiving element of the optical displacement sensor 24 changes. Therefore, the height of the liquid level can be detected by monitoring this change.

  Further, although the optical displacement sensor 24 is disposed on the upper portion of the holder 13, it may be on a side portion of the holder 13. In this case, although not shown, a mirror surface 22 that reflects light is placed on the side surface of the convex portion 11a of the float 11 that faces the light emitting / receiving surface of the optical displacement sensor 24 according to the height of the liquid surface. The displacement sensor 24 is provided with an inclination so that the distance between the light emitting / receiving surface and the mirror surface 22 is different.

  FIG. 3 is a sectional view showing a third embodiment of the present invention. FIG. 3 is a sectional view showing a third embodiment of the present invention. In the third embodiment of the present invention shown in FIG. 3, a shoulder portion continuous with the convex portion 11 a of the float 11 and a tip portion of the concave portion 13 a of the holder 13 are formed in a tapered shape. In this case, since a wide gap is secured between the opposing surfaces of the float 11 and the holder 13 when they approach each other, the float 11 adheres to the holder 13 due to surface tension, or the follow-up performance of the float 11 with respect to the liquid level is deteriorated. Can be prevented.

  Although the holder 13 of the first, second, and third embodiments described above is shown separately from the liquid tank 1, it can be formed integrally with the liquid tank 1. In this case, the detection means may be directly attached to the liquid tank 1 or may be attached as a separate body.

1 is a cross-sectional view of a liquid level detection device showing a first embodiment of the present invention, and is a diagram arranged in a liquid tank. Sectional drawing which shows 2nd Example of this invention Sectional drawing which shows 3rd Example of this invention It is sectional drawing which shows the liquid tank which has the liquid level detection apparatus and liquid level detection apparatus of this invention, and is a supplementary figure which shows the dimensional relationship of a liquid tank, a holder, and a float Sectional view showing a liquid level detection device according to the prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid tank 11 Float 11a Convex part 12 of a float 13 Magnet 13 Holder 13a Concave part 14 of a holder Hall element 22 Mirror surface 24 Optical displacement sensor 30 Liquid tank 31 Guide pipe 32 Float 33 Detection part

Claims (7)

In the liquid level detection device that detects the level of liquid level in the liquid tank,
A convex float having a detected portion;
A holder having a concave portion for fitting with the convex portion of the float, and a detecting means for detecting the position of the float, and a concave portion for restricting the moving direction of the float;
Liquid level detection device for detecting the level of the liquid level by detecting the position of the float that floats with the fluctuation of the liquid level in the liquid tank by means of a detection means of the holder that detects the detected portion provided in the float Because
The liquid level detection device according to claim 1, wherein the holder does not protrude inward from an inner wall surface of the liquid tank.   2. The liquid level detection device according to claim 1, wherein the detection target provided in the float is a magnet, and the detection means provided in the holder is a magnetic detection element.   The to-be-detected part provided in the convex float is a mirror provided at the tip of the float, and the detection means provided in the holder is a light emitting / receiving element installed on the bottom of the concave recess of the holder The liquid level detection device according to claim 1, wherein the liquid level detection device is an optical displacement sensor.   Either one of the shoulder part which continues to the convex part of the said float, the recessed part front-end | tip part of the said holder, or both is formed in the taper shape, It is any one of Claims 1-3 characterized by the above-mentioned. Liquid level detection device. A liquid tank having the liquid level detection device according to any one of claims 1 to 4,
A liquid tank having a liquid level detection device, wherein a holder of the liquid level detection device is installed on an upper end side or a lower end side of the liquid tank.   6. The liquid tank having a liquid level detection device according to claim 5, wherein the height of the float is longer than the distance between the tip of the holder recess and the inner wall surface of the liquid tank on the opposite side of the holder. The liquid tank having a liquid level detecting device according to claim 5 or 6, wherein the holder is formed integrally with a wall portion of the liquid tank.

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