JP3646701B2 - Liquid level indicator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid level gauge having a function of detecting the position of a float with a reed switch by detecting the position of the float along the top and bottom of the liquid level.
[0002]
[Prior art]
This type of liquid level gauge is widely used for industrial or household appliances. An example of a conventional liquid level gauge will be described with reference to FIG.
[0003]
1 includes a stem 3 extending up and down, a float 6 made of a nonmagnetic material capable of moving up and down with respect to the stem 3, a magnet 5 incorporated in the float 6, and a magnet 5 accompanying the vertical movement of the float 6. And a reed switch 4 that opens and closes the contact point according to the position fluctuation. Terminals at both ends of the reed switch 4 are connected to the harness 1. The position of the reed switch 4 is determined by pressing a terminal on one side of the reed switch 4 against the bottom surface of the stem 3. Further, the reed switch 4 is fixed to the stem 3 by the filling resin 8. A screw part 2 for attaching the liquid level gauge to household appliances and the like is provided at the upper part around the stem 3.
[0004]
The stem 3 is provided with a step 9 for determining the upper limit position of the float 6 and a stopper 7 for determining the lower limit position of the float 6 and preventing the float 6 from falling off. As the liquid level rises and falls, the float 6 moves up and down between the step 9 of the stem 3 and the stopper 7. Since the position of the magnet 5 varies depending on the up and down of the float 6, the contact of the reed switch 4 is repeatedly opened and closed according to a known principle. The liquid level is detected by opening and closing the contact of the reed switch 4.
[0005]
[Problems to be solved by the invention]
When the liquid level gauge of FIG. 1 is used, in order to detect a plurality of liquid levels, it is necessary to prepare as many liquid level meters as the number of liquid levels to be detected. Therefore, it is necessary to prepare as many stem molds as the number of liquid levels to be detected, which is expensive and troublesome.
[0006]
Therefore, an object of the present invention is to provide a liquid level meter that can easily and inexpensively cope with detection of a plurality of liquid levels.
[0007]
Another object of the present invention is to provide a liquid level gauge capable of easily changing the detection position.
[0008]
[Means for Solving the Problems]
According to the present invention, a stem that extends vertically, a float made of a non-magnetic material that can move up and down with respect to the stem, a magnet provided in the float, and a position change of the magnet that accompanies the vertical movement of the float. And a reed switch that opens and closes a contact point, the stem includes a circuit board having a long space above and below the stem, the reed switch is disposed in the space, and the reed switch extends along the space. The vertical position can be changed, and the stem is provided with a stopper for restricting the vertical position of the float, and a plurality of vertically spaced grooves for stopping the stopper. A liquid level gauge is obtained.
[0009]
The reed switch may be capable of changing a vertical position along the space.
[0010]
The stopper may be capable of changing a stopping position between the plurality of grooves.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 2, a liquid level gauge according to the embodiment of the present invention will be described.
[0012]
The liquid level gauge of FIG. 2 includes a cylindrical stem 13 made of a non-magnetic material extending up and down and closed at the lower end. A ring-shaped float 16 made of a nonmagnetic material that can move up and down is fitted to the lower portion around the stem 13. A ring-shaped magnet 15 is built in the float 16. A plurality of magnets may be arranged in a ring shape instead of the ring magnet.
[0013]
A reed switch 14 that opens and closes contacts by detecting the position of the magnet 15 as the float 16 moves up and down is disposed at the inner and lower portions of the stem 13. The float 16 moves up and down along the stem 13 as the liquid level of the liquid to be detected rises and falls.
[0014]
Further, a circuit board 20 such as a printed circuit board is disposed inside the stem 13. Further, the circuit board 20 is fixed to the stem 13 by the filling resin 18. A harness 11 is connected to the upper part of the circuit board 20. The harness 11 is drawn upward from the stem 13. In addition, the screw part 12 for attaching this level gauge to household appliances etc. is provided in the upper part around the stem 13.
[0015]
In a relatively lower portion of the circuit board 20, a void 21 is formed that is formed by a long hole that is long in the vertical direction. The reed switch 14 described above is disposed in the space 21. The reed switch 14 can be moved up and down within the space 21 of the circuit board 20 and fixed at both ends thereof to change the vertical position.
[0016]
In the lower part of the periphery of the stem 13, there are two stoppers 17, 17 'for regulating the vertical position of the float 16, and a plurality of grooves 19 formed at positions separated vertically to stop the upper stopper 17, respectively. Is provided. Each groove 19 preferably has a ring shape extending in the circumferential direction along the periphery of the stem 13. In this way, the stopper 17 can change the stop position between the plurality of grooves 19. That is, the stopper 17 is detachably fitted and fixed to a selected one of the plurality of grooves 19.
[0017]
As the liquid level rises and falls, the float 16 moves up and down between the upper and lower stoppers 17 and 17 ′ along the stem 13. Since the position of the magnet 15 varies depending on the up and down of the float 16, the contact of the reed switch 14 is repeatedly opened and closed according to a known principle. The liquid level is detected by opening and closing the contact of the reed switch 14.
[0018]
By moving the reed switch 14 within the range of the long hole 21 of the circuit board 20 and fixing both ends thereof, it is possible to change the position of the float 16, that is, the magnet 15 that opens and closes the reed switch 14. When the open / close position of the reed switch 14 is changed upward, the movable range of the float 16 is also moved upward. That is, the stopper 17 is moved upward to the upper groove among the plurality of grooves 19. Thus, the movable range of the float 16 can be easily changed.
[0019]
According to the liquid level gauge of FIG. 2, the detection position of the liquid level can be easily changed, and a plurality of liquid level positions can be detected with one mold.
[0020]
Each of the stem 13 and the float 16 is preferably made of resin or nonmagnetic metal. Of course, the number of grooves 19 may be three or more.
[0021]
【The invention's effect】
As described above, the liquid level gauge according to the present invention can easily change the open / close position of the reed switch, and can easily change the movable range of the float. By combining with the position of the stopper, it is possible to easily and inexpensively change the liquid level detection position.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a conventional liquid level gauge.
FIG. 2 is a cross-sectional view of a liquid level gauge according to an embodiment of the present invention.
[Explanation of symbols]
1,11 Harness 2,12 Screw part 3,13 Stem 4,14 Reed switch 5,15 Magnet 6,16 Float 7,17,17 'Stopper 8,18 Filling resin 9 Step 19 Groove 20 Circuit board 21 Space

Claims (1)

A stem that extends vertically, a float made of a non-magnetic material that can move up and down with respect to the stem, a magnet provided on the float, and a lead that opens and closes a contact according to a positional change of the magnet as the float moves up and down In the liquid level gauge including a switch, the stem includes a circuit board having a space long in the vertical direction, the reed switch is disposed in the space, and the reed switch is changed in a vertical position along the space. are those that can be, and the stem, a stopper for regulating the vertical position of the float, the liquid level meter, characterized in that a plurality of grooves spaced vertically for stopping the stopper.

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