JP2002228512A - Liquid level detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid level detector facilitating adjustment of the characteristics of a detection element and its assembly work, and allowing easy re-adjustment of the characteristics even after its assembly. SOLUTION: This liquid level detector 1 is equipped with a float 5 moving with fluctuations of the level of a liquid, a magnetic body 9 making turning movement with the movement of the float 5, and a detection element 10 for detecting a change in magnetic force due to the movement of the magnetic body 9. The detector 1 is further equipped with a turning shaft 6a for supporting the magnetic body 9, an eccentric body 7 on which the turning shaft 6a is turnably mounted, and a support piece 8b for supporting the turning shaft 6a via the eccentric body 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type liquid level detecting device. In particular, the present invention relates to a liquid level detection device capable of easily adjusting characteristics of a detection element.

[0002]

2. Description of the Related Art Conventionally, non-contact type liquid level detecting devices are disclosed in Japanese Patent Application Laid-Open Nos. 8-94413 and 11-281.
No. 465, for example. In these liquid level detecting devices, an MR element, a Hall element, or the like is used as a magnetic sensing element as a detecting element. And, in order to effectively use the characteristics of the detection element,
The liquid level has been detected by positioning and assembling the detection element with respect to a magnetic body such as a magnet.

[0003]

However, in the conventional liquid level detecting device, the detecting element is fixed to the magnetic material with an adhesive or the like, so that a high assembling accuracy is required and the liquid level detecting device is required. There was a problem that assembly of the device became difficult. Also, once the detection element is fixed, it is necessary to remove the adhesive and change the position of the detection element, and then fix the detection element again with the adhesive, which is very troublesome. There was a problem.

Accordingly, the present invention provides a liquid level detecting device that adjusts the characteristics of a detecting element, facilitates an assembling operation, and can easily adjust the characteristics even after assembling. Aim.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a float that moves with a change in the liquid level, a magnetic material that rotates with the movement of the float, and a magnetic material that moves with the change in the magnetic material. A liquid level detecting device comprising a detecting element for detecting a change in magnetic force, a rotating shaft supporting the magnetic body, an eccentric body on which the rotating shaft is rotatably mounted, and And a support piece for supporting the rotation shaft via an eccentric body.

The eccentric body has a disk shape and is provided with a hole through which the rotating shaft passes at a position off the center point.

Further, the eccentric body is provided with a scale, and a plurality of scales are formed around a supporting portion of the support piece for supporting the eccentric body.

[0008] In addition, the floating which moves with the fluctuation of the liquid level,
A liquid level detection device comprising: a magnetic body that fluctuates according to the movement of the float; and a detection element that detects a change in magnetic force in accordance with the fluctuation of the magnetic body, wherein a liquid level detection device is provided between the magnetic body and the detection element. And a magnetic member for adjusting output characteristics of the detection element.

Further, the magnetic member is provided on a main body frame.

Further, the magnetic member has a screw shape having a spiral groove.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid level detecting device according to the present invention comprises a float 5 which is a float which moves with a change in the liquid level, a magnetic body 9 which rotates with the movement of the float 5, and a fluctuation of the magnetic body 9. A liquid level detecting device 1 including a detecting element 10 for detecting a change in magnetic force.
And an eccentric body 7 on which the rotating shaft 6a is rotatably mounted, and a support piece 8b for supporting the rotating shaft 6a via the eccentric body 7. With this configuration, the characteristics of the detection element 10 are adjusted, and the assembling work is easy.
Further, it is possible to provide the liquid level detecting device 1 whose characteristics can be easily readjusted even after assembling.

The eccentric body 7 has a disk shape and is provided with a hole 7a through which the rotating shaft 6a penetrates at a position off its center point. With this configuration, it is possible to provide a liquid level detection device 1 that can adjust the characteristics of the detection element 10 and can easily perform the assembling work, and can easily readjust the characteristics even after the assembling. Can be.

Also, a scale 7b is formed on the eccentric body 7, and a plurality of scales 8e are formed around a support portion 8a of the support piece 8b which supports the eccentric body 7. With such a configuration, the detecting element 10 at the time of assembling or after assembling is obtained.
The liquid level detecting device 1 which can easily finely adjust the characteristics of the liquid crystal display can be provided.

Further, a float 5 which is a float which moves with the fluctuation of the liquid surface, a magnetic body 9 which fluctuates with the movement of the float 5, and a detecting element 10 which detects a change in magnetic force with the fluctuation of the magnetic body 9 And a magnetic member 27 for adjusting the output characteristic of the detection element 10 is provided between the magnetic body 9 and the detection element 10. With this configuration, it is possible to provide a liquid level detection device 1 that can adjust the characteristics of the detection element 10 and can easily perform the assembling work, and can easily readjust the characteristics even after the assembling. Can be.

The magnetic member 27 is provided on the main body frame 8. With this configuration, the magnetic member 27 can be disposed close to the detection element 10.

The magnetic member 27 has a screw shape with a spiral groove. With this configuration, it is possible to provide the liquid level detection device 1 that can easily perform fine adjustment of the characteristics of the detection element 10 during or after assembly.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The liquid level detecting device 1 of the present invention detects the liquid level 4 of the liquid 3 in the tank 2. Liquid level detection device 1
Is a float 5 of the present invention floating on the liquid surface, a float arm 6 interlocking with the float 5, a rotating shaft 6a integrally formed with the float arm 6, and a rotating shaft 6a. An eccentric body 7 movably mounted, a main body frame 8 having a support portion 8a for supporting a rotating shaft 6a via the eccentric body 7, and a magnetic body 9 which rotates together with the rotating shaft 6a.
And a detection element 10 housed in the main body frame 8 for detecting the magnetic flux density of the magnetic body 9, and a circuit board 12 holding the detection element 10 and having a holding member 11. Reference numeral 13 denotes a filler made of a synthetic resin filled in the main body frame 8 for the purpose of protecting the detection element 10 and the circuit board 12 housed in the main body frame 8 and the like. This is a lead wire for outputting the resulting signal to the outside of the liquid level detecting device 1.

The liquid level detecting device 1 is partially disposed in the tank 2 through a through hole 2a below the tank 2 as shown in FIG. The main body frame 8 of the liquid level detecting device 1 includes:
An O-ring 15 is provided, and is made watertight so that the liquid 3 does not leak from between the through hole 2a and the main body frame 8.

In this embodiment, the float 5 is made of a metal material that is hardly corroded, such as stainless steel, and moves with the fluctuation of the liquid level 4. In addition, the material of the float 5 is not limited to the above-mentioned material, and may be formed of a synthetic resin or the like.

The float arm 6 is made of a non-magnetic metal, and the one end holds the float 5 and the other end is a rotating shaft 6a that supports the magnetic body 9. In the present embodiment, the float arm 6 is integrally formed. Have been. The rotating shaft 6a is supported by a support portion 8a of a main body frame 8 described later via two eccentric bodies 7.

The eccentric body 7 has a disk shape, and the hole 7 penetrates at a position deviated from the center of the disk shape deviated from the center.
a, and a rotating shaft 6a penetrates through the hole 7a in a rotatable manner. The support portion 8a is formed by holes penetrating through two plate-like support pieces 8b provided to protrude from the main body frame 8, and the support portion 8a has a size rotatable when the eccentric body 7 is fitted. is there. The support piece 8b has a screw hole 8c that penetrates the support portion 8a in the vertical direction.
Is provided. Reference numeral 8d denotes a screw screwed into the screw hole 8c, which fixes the eccentric body 7 rotatably fitted to the support portion 8a.

One scale 7b is formed on the eccentric body 7, and a plurality of scales 8e are formed around the support portion 8a.

Next, the fixing of the eccentric body 7 to the support portion 8a will be described. First, the eccentric body 7 is fitted into the support portion 8a. Next, the scales 7b of the two eccentric bodies 7 are aligned with the same scales 8e of the main body frame 8, and the screws 8d are screwed into the screw holes 8c, whereby the eccentric bodies 7
Easily fixed to By providing the scales 7b and 8e in this manner, the left and right eccentric bodies 7 can be accurately fixed at the same position, and the workability is improved.

The magnetic body 9 uses a magnet in this embodiment,
Its shape is a disk shape, and it is two-pole magnetized. The magnetic body 9 is fixed so as to rotate together with the rotation shaft 6a.

For fixing the magnetic body 9 to the rotating shaft 6a, a magnet holder 16, a nut 17, a washer 18 and a screw 19 are used. Magnet holder 16, nut 17, and washer 1
8 and the like are also formed of a non-magnetic material.

The magnet holder 16 has a thin cylindrical portion 16a and a thick cylindrical portion 16b through which the magnet 9, the nut 17, and the washer 18 penetrate, and has a step 16c between the cylindrical portions 16a and 16b. . Note that a screw portion 16d to which the nut 17 is screwed is formed in the cylindrical portion 16a.
The cylindrical portion 16b is provided with a through hole 16e having a screw portion into which the screw 19 is screwed. 16f is a through hole through which the float arm 6 penetrates.

Next, the fixing of the magnetic body 9 to the rotating shaft 6a will be described. First, the magnetic body 9 is fixed to the magnet holder 16. This fixing is performed by passing the magnetic material 9 through the cylindrical portion 16a of the magnet holder 16, screwing a nut 17 into a screw portion formed on the magnet holder 16, and screwing the nut 17 together.
7 is completed by sandwiching the magnetic body 9. The magnetic material 9
A washer 18 is provided between the nut 17 and the magnetic body 9 to prevent damage to the magnetic member 9. Next, in order to pass the rotating shaft 6a through the through hole 15f of the magnet holder 16 to which the magnetic body 9 is fixed, and to fix the magnet holder 16 at a position that satisfies the positional relationship between the rotating shaft 6a and the detection element 10, A screw 19 is screwed into the through hole 16e, and the screw 19 is brought into contact with the rotating shaft 6a, so that the magnet holder 16 is fixed to the rotating shaft 6a.

By adopting the fixing structure described above, the magnetic body 9 can be
By changing the interval between the two, the characteristics of the detection element 10 can be adjusted and the assembling operation can be easily performed. In addition, it is possible to provide the liquid level detection device 1 that can easily perform adjustment after assembly.

The provision of the scales 7b and 8e on the eccentric body 7 and the support portion 8a, respectively, provides a guide for the assembling work or the work after the assembling work, and also allows fine adjustment at the time of characteristic adjustment. It also serves as a guide and improves workability.

The main body frame 8 is formed of a non-magnetic metal material such as stainless steel, and has a cylindrical shape. Inside, a storage space 20 for storing the detection element 10, the circuit board 12, and the like is provided. Around the opening 21 of the storage space 20 (lower side of the main body frame 8 shown in FIG. 2)
Is provided with a collar portion 22. The collar 22 is fixed to the tank 2 using the flange 22. In the fixing method, a plurality of through holes (not shown) are provided in the flange portion 22, and screws (not shown) are inserted into the holes and fixed. The main body frame 8 may be made of a synthetic resin as long as it is a non-magnetic material.

The detecting element 10 is accommodated in the accommodating space 20 of the main body frame 8. In this embodiment, a Hall IC is used as the detecting element 10 to detect the rotation of the magnetic body 9. Note that the detection element 10 is not limited to this embodiment, and any detection element may be used as long as it can detect the rotation of the magnetic body 9. For example, an MR element Or the like may be used.

The holding member 11 is a member for holding the detection element 10 in the storage space 20 so as not to be displaced when the filler is filled into the storage space 20 or when the filler is cured.

The circuit board 12 is made of a hard board made of glass epoxy resin or the like, and the leads 23 extending from the detecting element 10 are fixed by soldering, and the holding member 11 is fixed. Electronic components (not shown) are mounted on the circuit board 12. In addition, lead wire 14
Are also fixed by solder. A part of the detection element 10, the holding member 11 and a part of the circuit board 12 are fixed in the storage space 20 by the filler 13.

Next, detection of the liquid level 4 of the liquid level detecting device 1 of this embodiment will be described.

The float 5 fluctuates with the fluctuation of the liquid surface 4, and the fluctuation of the float 5 causes the rotation shaft 6a to rotate together with the float arm 6 around the hole 7a as a fulcrum. This rotation also causes the magnetic body 9 to rotate. Due to this rotation, the magnetic flux density of the magnetic body 9 facing the detection element 10 fluctuates. The fluctuation is detected by the detection element 10, and a signal is output to an external device (not shown) by the lead wire 14 via the circuit board 12. , To detect the liquid level.

In the first embodiment, a magnet is used for the magnetic body 9. However, the present invention is not limited to the above embodiment. For example, a soft magnetic body such as pure iron may be used for the magnetic body 9. In this case, the detection element 10 detects a change in the distance between the soft magnetic material and the detection element 10.
It is necessary to provide a permanent magnet (may be an electromagnet) in a portion of the holding member 11 located behind the backing. With this configuration, the liquid surface can be detected even when a soft magnetic material is used as the magnetic material 9, and the magnetic material 9 can be used even when the soft magnetic material is exposed to water or an aqueous solution.

Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, the same reference numerals are given to the same and corresponding parts as those in the embodiment, and the detailed description thereof will be omitted.

In this embodiment, the rotating shaft 6a is rotatably supported by the supporting portion 8f of the main body frame 8 without using the eccentric body 7 of the above embodiment. This support portion 8f is a through hole. In this embodiment, a hole 26 is provided in the main body frame 8 between the magnetic body 9 and the detection element 10, and a magnetic member 27 is provided in the hole 26. A screw groove is formed in the hole 26, and the magnetic member 27 has a screw shape with a spiral groove. With such a configuration, the magnetic flux path between the magnetic body 9 and the detection element 10 is changed so that the detection element 10
Characteristics can be changed. Therefore, the assembling work is easy, and the characteristics of the detection element 10 can be adjusted after the assembling. Further, even after the assembly, the characteristics can be easily readjusted.

Further, since the magnetic member 27 is provided on the main body frame 8, the magnetic member 27 can be disposed close to the detection element 10, and the characteristics of the detection element 10 can be adjusted more favorably. .

Further, since the magnetic member 27 has a screw shape, the characteristics can be easily adjusted even when the characteristics are adjusted at the time of assembling or after assembling. In addition, workability is good because the adjustment only requires turning the screw.

In each of the above embodiments, the rotating shaft 6a is
Although fixed by one support piece 8b, the present invention is not limited to the above embodiments, and may be a structure supported by one support piece 8b. Further, in each of the above embodiments, the rotary shaft 6a is formed integrally with the float arm 6, but this is not limited to each of the above embodiments.
The rotation shaft 6a may be formed separately from the float arm 6.

[0042]

As described above, according to the present invention, the initial object can be achieved, the characteristics of the detection element can be easily adjusted, and the characteristics can be easily readjusted even after assembly. A liquid level detection device can be provided.

[Brief description of the drawings]

FIG. 1 is a side view of a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view taken along line AA in FIG.

FIG. 3 is a perspective view of a main part of the embodiment.

FIG. 4 is a side view of a second embodiment of the present invention.

FIG. 5 is a partial sectional view taken along line BB in FIG. 2;

[Explanation of symbols]

 Reference Signs List 1 liquid level detection device 2 tank 2a through hole 3 liquid 4 liquid level 5 float (floating) 6 float arm 6a rotating shaft 7 eccentric body 7a hole 7b scale 8 body frame 8a support portion 8b support piece 8c screw hole 8d screw 8e Scale 8f Support portion 9 Magnetic body 10 Detecting element 11 Holding member 12 Circuit board 13 Filler 14 Lead wire 15 O-ring 16 Magnet holder 16a, 16b Cylindrical portion 16c Step portion 16d Screw portion 16e Through hole 16f Through hole 17 Nut 18 Washer 19 Screw 20 Storage space 21 Opening 22 Flange 23 Lead 24 Nickel 25 Fluororesin 26 Hole 27 Magnetic member

Claims (6)

[Claims] 1. A liquid comprising: a float that moves in accordance with a change in a liquid level; a magnetic body that rotates in accordance with the movement of the float; and a detection element that detects a change in magnetic force in accordance with the change in the magnetic body. A surface detection device, comprising: a rotating shaft that supports the magnetic body; an eccentric body on which the rotating shaft is rotatably mounted; and a support that supports the rotating shaft via the eccentric body. A liquid level detection device comprising: 2. The liquid level detecting device according to claim 1, wherein the eccentric body has a disk shape, and is provided with a hole through which the rotating shaft passes at a position off its center point. 3. The liquid level detecting device according to claim 2, wherein a scale is formed on the eccentric body, and a plurality of scales are formed around a support portion of the support piece that supports the eccentric body. . 4. A liquid surface comprising: a float that moves with a change in the liquid surface; a magnetic body that changes with the movement of the float; and a detection element that detects a change in magnetic force due to the change in the magnetic material. A liquid level detecting device, comprising: a magnetic member for adjusting output characteristics of the detecting element between the magnetic body and the detecting element. 5. The liquid level detecting device according to claim 4, wherein said magnetic member is provided on a main body frame. 6. The liquid level detecting device according to claim 5, wherein the magnetic member has a screw shape having a spiral groove.