JP4207898B2 - Liquid level detector - Google Patents

Description

  The present invention relates to a liquid level detection device that detects the height of a liquid level, and is suitable, for example, for detecting the remaining amount of fuel in a fuel tank indicated by the height of the liquid level.

Conventionally, in Patent Document 1, an oil level gauge that detects the height of an oil level is disclosed as a liquid level detection device. This oil level gauge is provided with a guide for guiding the float to move up and down, and by providing a flange-like stopper for this guide, the movement limit position of the float is regulated, The rotation angle is set within a predetermined range. The guide is configured in a straight line, and when the float moves along the guide, the distance from the pivot center of the pivot arm to which the float is attached to the float changes. The arm is divided into a float-side arm that can slide the shaft-side arm, and the shaft-side arm slides within the float-side arm so that the change in the distance can be absorbed.
Japanese Utility Model Publication No. 62-143219

  However, in the case of the structure shown in Patent Document 1, the rotating arm is divided into the shaft side arm and the float side arm, which makes the structure complicated and heavy. Since the shaft side arm and the float side arm are always located on the float side with respect to the center of rotation, the size of the float required to float on the liquid surface is the same as that of the shaft side arm and the float side arm. The total weight must be taken into consideration, and there is a problem that the float cannot be reduced in size.

  In view of the above points, an object of the present invention is to provide a liquid level detection device capable of reducing the size of a float.

In order to achieve the above object, the invention described in claim 1 is provided with a bar-shaped guide (9) facing the top-and-bottom direction, and a hole (8b) penetrating in the vertical direction is formed in the float (8). As the guide (9) is inserted into the hole (8b), the float (8) is guided by the guide (9) to move up and down, and the rotating arm (4) The body (2) is provided with a holder (3) that rotates about the rotation shaft (2b) and holds the rotation arm (4). The holder (3) has a disk-shaped part (3a), and the linear part of the rotating arm (4) is a disk-shaped part ( 3f) provided in the holder (3). scan to slide in the radial direction of 3a), the distance of the float from the rotational center (8) is a adjustable structure Cage, rotating arms (4), upon slide in a provided grooves in the holder (3) (3f), are adapted to protrude on the opposite side to be a float (8) from the rotation center, The liquid level detecting means is provided with a magnet (5) that rotates about the rotation axis (2b) in the holder (3), and the magnet (5) is generated in the rotation axis (2b). A magnetic reaction element (6) that generates an output corresponding to a change in magnetic flux density, and a liquid based on a change in magnetic flux density that occurs when the magnet (5) rotates about the rotation axis (2b). It is a magnetoresistive type that detects the height of the liquid level .

  As described above, the pivot arm (4) slides in the groove (3f) of the holder (3), so that the float (8) can move up and down along the guide (9) as the liquid level changes. I am doing so. For this reason, since it is not necessary to comprise a rotation arm (4) by several components unlike the past, it becomes possible to achieve simplification of the structure of a rotation arm (4), and weight reduction. Accordingly, it is possible to reduce the size of the float (8) determined from the weight of the rotating arm (4) and the weight of the float (8) itself.

  Thus, when the rotating arm (4) rotates, the rotating arm (4) slides in the groove (3f) of the holder (3), and the rotating arm on the side opposite to the float (8). (4) protrudes. For this reason, the weight of the protruding portion of the rotating arm (4) acts as a force in the direction of floating the float (8), and the size of the float (8) can be further reduced.

The rotating arm (4) used in such a liquid level detecting device is constituted by, for example, a rod-like member or a pipe-like member as shown in claim 2 . Moreover, since it is desirable that the rotating arm (4) is lightweight, for example, the rotating arm (4) is preferably made of aluminum. In addition, a stainless steel material is preferable in order to achieve stable sliding stability. Anyway, adoption is possible.

In the invention described in claim 3 , the holder (3) is formed with a claw portion (3d) for holding the rotating arm (4), and the float (8) of the rotating arm (4) is held. A bent portion (4a) is formed at the end opposite to the side, and the bent portion (4a) of the rotating arm (4) comes into contact with the claw portion (3d), so that the rotating arm (4) It is characterized in that a structure for preventing removal from the holder (3) is constructed.

  As described above, even if the rotating arm (4) is configured to be slidable in the groove (3f), the holder (3) is provided with the claw portion (3f) and the rotating arm (4) By providing the bent portion (4a) at the end opposite to the side on which the float (8) is held, a structure for preventing the rotation arm (4) from coming off from the holder (3) can be provided.

As the liquid level detection device as described above, for example, as shown in claim 4 , both ends of the guide (9) are respectively provided with a fixing plate (2ca) and a holding portion (2d) provided on the main body (2). ), And the fixing plate (2ca) and the holding part (2d) may define a lower limit position and an upper limit position of the float (8), respectively. In addition, the present invention can be applied to other types of liquid level detection devices such as a so-called resistance type or reed switch type liquid level detection device.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
A first embodiment of the present invention will be described. 1 is a front view of the liquid level detection device of the present embodiment, and FIG. 2 is a partial cross-sectional view of the liquid level detection device of the present embodiment, showing a cross section of a straight line portion in a two-dot chain line Z in FIG. It is a thing.

  The liquid level detection device shown in FIGS. 1 and 2 is used to detect the remaining amount of the fuel 1 by measuring the height of the liquid level of the fuel 1 in the fuel tank 10. This liquid level detection device is fixed at the lowest position on the bottom surface of the fuel tank 10, and includes a body 2, a magnet holder 3, a rotating arm 4, a magnet 5, a magnetic reaction element 6, a terminal 7, a float 8, and A guide 9 is provided.

  The body 2 constitutes the main body of the liquid level detection means, and is made of a non-conductive material such as a resin. The body 2 includes a support surface 2a, a rotating shaft 2b, a stay 2c, and a holding portion 2d.

  The support surface 2 a is assembled so as to be perpendicular to the bottom surface of the fuel tank 10. The rotation shaft 2b is a portion that becomes the rotation center of the magnet holder 3, and is provided so as to protrude in a direction perpendicular to the support surface 2a. A groove 2ba is formed on the outer periphery of the rotation shaft 2b. Yes.

  The stay 2c is provided so as to protrude in a direction perpendicular to the support surface 2a at a position below the rotation shaft 2b, and is provided as a reinforcement for the stay. In the lower position of the stay 2c, the fixing plate 2ca is formed so as to be bent in the horizontal direction so as to face the bottom surface of the fuel tank 10. One end of the guide 9 is fixed to a surface of the fixing plate 2ca of the stay 2c opposite to the bottom surface of the fuel tank 10. Here, the liquid level detection device is connected and fixed to the tank or a bracket fixed to the tank by the body back surface 2e (not shown).

  The holding portion 2d is provided at a position above the body 2 so as to protrude in the vertical direction from the support surface 2a, and is provided so as to face the fixing plate 2ca in the stay 2c described above. The other end of the guide 9 is fixed to the lower surface of the holding portion 2d.

  And in the body 2 comprised in this way, it has the structure arrange | positioned so that the terminal 7 may be exposed above the body 2 and may be extended to the rotating shaft 2b.

  The magnet holder 3 is held so as to be rotatable with respect to the body 2 and incorporates a magnet 5. A rotating arm 4 is held by the magnet holder 3, and the rotating arm 4 rotates with respect to the body 2 as the magnet holder 3 rotates.

  Specifically, the magnet holder 3 is composed of a disc-shaped portion 3 a that accommodates the magnet 5, and a protruding portion 3 b that extends from the disc-shaped portion 3 a in accordance with the shape of the rotating arm 4. The central part of the disc-shaped part 3a is hollow, and when the rotating shaft 2b extended from the body 2 is fitted into this hollow part, the groove part 2ba formed on the outer periphery of the rotating shaft 2b is inserted. By fitting the protruding portion 3c protruding from the inside of the hollow portion of the disk-shaped portion 3a, the magnet holder 3 can be rotated without coming off in the axial direction with respect to the body 2.

  A claw portion 3 d for holding the rotating arm 4 is formed on the surface of the magnet holder 3. The claw portion 3d has a hook shape, and is held so as to be slidable with respect to the claw portion 3d when the rotating arm 4 is fitted. Here, the claw portion may be manufactured integrally with the holder, or may be assembled and fixed in the form of a lid with another part.

  Further, projections 3 e are formed on both sides of the surface of the disk-shaped portion 3 a in the magnet holder 3 along the extension line of the rotating arm 4. The protrusion 3e is for forming a groove 3f on the extension line of the rotating arm 4, and guides the rotating arm 4 when the rotating arm 4 slides.

  The rotating arm 4 is made of, for example, a metal (aluminum or the like) rod-like member or pipe-like member in order to reduce the weight, and is made by bending the rod-like member or pipe-like member in some places. . One end of the rotating arm 4 is held by the magnet holder 3, and the other end holds the float 8. Specifically, a bent portion 4 a is formed at the end of the rotating arm 4 on the side held by the magnet holder 3, and the bent arm 4 d makes the rotating arm 4 a claw portion 3 d of the magnet holder 3. It comes to be prevented from leaving. Further, the end of the rotating arm 4 on the side holding the float 8 is bent in a direction parallel to the rotating shaft 2b (horizontal direction) and opposite to the protruding direction of the rotating shaft 2b from the support surface 2a. The float 8 is rotatably held at the bent portion. Since the rotating arm 4 is composed of a rod-shaped member or a pipe-shaped member (for example, a rod-shaped member or a pipe-shaped member having a circular cross section), the inner wall surface of the claw portion 3d of the magnet holder 3 is held on the side where the float 8 is held. Can be slid from the end portion to the end portion on the side held by the magnet holder 3, and the distance of the float 8 from the rotation center can be adjusted.

  The magnet 5 is accommodated in a disc-shaped portion 3 a in the magnet holder 3. When the rotating arm 4 is rotated, for example, like a sector, the magnet 5 changes the density of the magnetic flux generated by the magnet 5 passing through the rotating shaft 2b according to the rotating state. It has a shape.

  The magnetic reaction element 6 is arranged in the rotating shaft 2b and generates an output corresponding to the density of magnetic flux generated by the magnet 5. Accordingly, when the magnet 5 moves with the rotation of the rotating arm 4, the magnetic flux density passing through the magnetic reaction element 6 changes accordingly, and thus different outputs can be generated from the magnetic reaction element 6. ing.

  The terminal 7 includes a power supply terminal that supplies power from an external power source to the magnetic reaction element 6, an output terminal for taking out the output of the magnetic reaction element 6, and the like. Through a wire 7a connected to this terminal 7, although not shown, it is connected to an external power source or a control device that receives the output of the magnetic reaction element 6.

  The float 8 is formed in a substantially rectangular shape, and is formed in a foamed or hollow shape so as to float on the liquid level of the fuel 1. The float 8 is formed with a hole 8a that is blocked in front of the guide hole 8b in the horizontal direction, and the end of the rotating arm 4 is fitted into the hole 8a, so that the float 8 can be 4 is held. However, since the end of the rotating arm 4 is loosely fitted into the hole 8 a of the float 8, the float 8 can be rotated with respect to the end of the rotating arm 4.

  The float 8 is also formed with a hole 8b penetrating in the vertical direction. A guide 9 is inserted into the hole 8b. However, since the guide 9 is loosely fitted in the hole 8 b of the float 8, the float 8 can slide with respect to the guide 9.

  The guide 9 is constituted by a straight rod-like member having a circular cross section, for example. Both ends of the guide 9 are fixed to the fixing plate 2ca of the stay 2c in the body 2 and the lower surface of the holding portion 2d, respectively, so that when the liquid level detection device is fixed to the fuel tank 10, it faces in the vertical direction. It has a configuration like this. Since the float 8 moves up and down along the guide 9 thus fixed, the lower limit position and the upper limit position of the float 8 are respectively the upper surface of the fixing plate 2ca of the stay 2c and the holding portion 2d in the body 2. It becomes the lower surface of.

  Next, the operation of the liquid level detection device of the present embodiment configured as described above will be described with reference to the state during operation of the liquid level detection device shown in FIG.

  In the liquid level detection device of the present embodiment, when the position of the float 8 moves according to the fluctuation of the liquid level of the fuel 1, the rotation arm 4 rotates about the rotation axis 2b accordingly. At this time, since the linear portion 9 a of the guide 9 is inserted into the hole 8 b of the float 8, the float 8 moves up and down along the guide 9. Since the distance from the rotation shaft 2b, which is the rotation center of the rotation arm 4, to the guide 9 changes according to the liquid level, as shown in FIG. The arm 4 slides in the groove 3f of the magnet holder 3, and the fluctuation is absorbed.

  Further, when the magnet 5 moves with the rotation of the rotating arm 4, the magnetic flux density passing through the magnetic reaction element 6 changes accordingly, so that different outputs are generated from the magnetic reaction element 6. Therefore, based on the output of the magnetic reaction element 6, the rotating state of the rotating arm 4, that is, the position of the float 8 is recognized, and the remaining amount of the fuel 1 can be detected from the height of the liquid level of the fuel 1. It becomes.

  As described above, in the liquid level detection device of the present embodiment, the float 8 moves along the guide 9 along with the change in the liquid level as the rotating arm 4 slides in the groove 3 f of the magnet holder 3. It can be moved up and down.

  For this reason, since it is not necessary to comprise the rotation arm 4 by several components unlike the past, it becomes possible to achieve the simplification of the structure of the rotation arm 4, and weight reduction. Therefore, the size of the float 8 determined from the weight of the rotating arm 4 and the weight of the float 8 itself can be reduced.

  Further, when the rotating arm 4 is rotated according to the height of the liquid level of the fuel 1, the rotating arm 4 slides in the groove 3 f of the magnet holder 3. Is in a state where the bent portion 4a side of the rotating arm 4 protrudes to the opposite side. For this reason, the weight of the protruding portion of the rotating arm 4 acts as a force in the direction of floating the float 8, and the size of the float 8 can be further reduced.

(Other embodiments)
In the first embodiment, the liquid level detection using the magnet 5 and the magnetic reaction element 6 has been described as an example. However, the electrical resistance value changes as the rotating arm 4 rotates. The present invention may be applied to other types of liquid level detection devices such as a so-called resistance type or reed switch type liquid level detection device that performs liquid level detection based on the above.

  In the above embodiment, the liquid level detection device that detects the liquid level of the fuel 1 stored in the fuel tank 10 has been described as an example, but of course, the liquid level of the liquid stored in the tank is detected. It can be applied to anything as long as it is.

It is a front view of the liquid level detection apparatus in 1st Embodiment of this invention. It is sectional drawing of the liquid level detection apparatus shown in FIG. It is the front view which showed the mode in operation | movement of the liquid level detection apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel, 2 ... Body, 2a ... Support surface, 2b ... Rotary axis, 2ba ... Groove part,
2c ... stay, 2ca ... fixing plate, 2d ... holding part, 2da ... holding hole,
3 ... Magnet holder, 3a ... Disc-shaped part, 3b ... Projection part, 3c ... Projection part,
3d ... Claw part, 3e ... Projection part, 3f ... Groove part, 4 ... Rotating arm, 4a ... Bending part,
5 ... Magnet, 6 ... Magnetic reaction element, 7 ... Terminal, 7a ... Wire,
8 ... float, 8a, 8b ... hole, 9 ... guide, 10 ... fuel tank.

Claims (4)

A float (8) whose position moves up and down according to the height of the liquid level of the liquid contained in the tank (10);
A rotating arm (4) for holding the float (8) and rotating as the float (8) moves;
The rotating shaft (2b) of the rotating arm (4) is provided, and an output corresponding to the rotating state of the rotating arm (4) is generated, so that the float (8) is positioned. In a liquid level detection device comprising a main body (2) having liquid level detection means (5, 6, 7) for detecting the height of the liquid level based on
A rod-shaped guide (9) facing the top-and-bottom direction is provided, and the float (8) is formed with a hole (8b) penetrating in the vertical direction, and the guide (9) is formed in the hole (8b). By being inserted, the float (8) is guided by the guide (9) to move up and down ,
The pivot arm (4) has a linear portion,
Furthermore, the main body (2) is provided with a holder (3) that rotates about the rotation shaft (2b) and holds the rotation arm (4) .
The holder (3) has a disk-shaped part (3a),
Wherein the linear portion of the pivot arm (4) provided in the holder (3) in the groove (3f) is slide in a radial direction of the disk-shaped portion (3a), from the rotation center The distance of the float (8) is adjustable.
When the rotation arm (4) slides in the groove (3f) provided in the holder (3), the rotation arm (4) protrudes to the opposite side of the float (8) from the rotation center. And
The liquid level detecting means includes a magnet (5) that rotates about the rotation shaft (2b) in the holder (3), and the magnet ( A magnetic reaction element (6) that generates an output corresponding to a change in magnetic flux density generated by 5), and the magnetic flux density generated when the magnet (5) rotates about the rotation shaft (2b). The liquid level detection device is of a magnetoresistive type that detects the height of the liquid level based on the change of the liquid level. The liquid level detection device according to claim 1 , wherein the rotating arm (4) is constituted by a rod-like member or a pipe-like member. The holder (3) is formed with a claw portion (3d) for holding the rotating arm (4),
A bent portion (4a) is formed at the end of the rotating arm (4) opposite to the side on which the float (8) is held,
The bending portion (4a) of the rotating arm (4) is in contact with the claw portion (3d), so that a structure for preventing the rotating arm (4) from coming off from the holder (3) is configured. The liquid level detection device according to claim 1, wherein: Both ends of the guide (9) are fixed to a fixing plate (2ca) and a holding portion (2d) provided on the main body (2), respectively, and the fixing plate (2ca) and the holding portion (2d) are fixed. ) Define a lower limit position and an upper limit position of the float (8), respectively.

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