JPH06331424A - Liquid level switch - Google Patents

Abstract

PURPOSE:To prevent the flicker phenomenon of a warning bulb with a simple structure, by providing a float with a magnet near a reed switch fixed in a fixed height position from a reference plane and by providing the reed switch with a holding circuit. CONSTITUTION:In a fixed height position within a housing 3, a reed switch 5 for switching on and off a lighting circuit of a warning bulb is provided. One end of the reed switch 5 is connected to a lead wire 4, and the other end is connected to an end of a self holding coil 10. One end of the coil 10 is connected to the other lead wire 4. On a peripheral surface of the housing 3, an annular float 6 with a magnet is vertically movably disposed. When a liquid level 9 is temporarily lowered because of the rotation of a car, etc., and the float 6 descends to the height of the reed switch 5, the switch 5 is made by the action of the magnet 7 and thereafter kept in an on-state by the coil 10. Therefore, the flicker phenomenon of the warning bulb can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid level detector, and more particularly to a liquid level detector suitable as a washer level switch, a reserve tank switch and the like.

[0002]

2. Description of the Related Art Conventionally, a liquid level detector as shown in FIG. 4 has been known as a liquid level detector. Liquid level detector 1 shown in FIG.
Is provided with a cylindrical housing 3 projectingly provided on the bottom surface 2a of the tank 2 so as to extend inside the tank 2, and the lead is provided at a predetermined height position from the reference surface (tank bottom surface 2a) inside the housing 3. A reed switch 5 connected to the wire 4 is arranged, and an annular magnet-equipped float 6 is arranged on the outer peripheral surface of the housing 3 so as to be vertically movable. Here, the reed switch 5 is a switch for closing a warning circuit for lighting a warning valve (not shown), and as the liquid level 9 is lowered, the float 6 is positioned at the height position of the reed switch 5. When it goes down, the magnet 7 is turned on by the action of the magnet 7 to close the warning circuit and turn on the warning valve.

[0003]

However, in the above-mentioned prior art, the liquid level 9 is caused by the turning or acceleration / deceleration of the vehicle.
When the float 6 descends to the height position of the reed switch 5 due to a large fluctuation, the warning valve lights up, causing a so-called "flicker" phenomenon.

In view of the above problems, it is an object of the present invention to prevent the "flickering" phenomenon of a warning valve with a simple structure.

[0005]

In order to solve the above problems, a liquid level detector according to the present invention comprises a reed switch fixed at a predetermined height position from a reference surface, and a reed switch near the reed switch. In a liquid level detector including a float with a magnet arranged so as to move up and down according to the liquid level, the reed switch is provided with a self-holding circuit.

[0006]

The function of the self-holding circuit is that once the reed switch is turned on, the self-holding circuit keeps the warning valve connected to the reed switch in the lit state, which causes the "flickering" phenomenon of the warning valve. Can be prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows a side cross section of a liquid level detector according to an embodiment.

In FIG. 1, a liquid level detector 1 is a tank 2
The bottom surface 2a of the above is provided with a cylindrical housing 3 that is provided so as to extend inside the tank 2. A reed switch 5 for opening and closing the lighting circuit of the warning valve 8 as shown in FIG. 2 is arranged at a predetermined height position from the reference surface (tank bottom surface 2a) inside the housing 3.
Here, one end of the reed switch 5 is connected to the lead wire 4, the other end is connected to one end of the self-holding coil 10 wound around the outer circumference of the reed switch 5, and the other end of the self-holding coil 10 is Connected to the lead wire 4.

An annular float 6 with a magnet is arranged on the outer peripheral surface of the housing 3 so as to be vertically movable. The float 6 has a magnet 7 when the liquid level 9 is lowered to the height position of the reed switch 5 as shown by the chain double-dashed line in FIG.
The reed switch 5 is turned on by the action of.

Next, the operation of the liquid level detector 1 having the above structure will be described.

When the liquid level 9 is temporarily lowered by the turning or acceleration / deceleration of the vehicle and the float 6 is lowered to the height position of the reed switch 5, the reed switch 5 is turned on by the action of the magnet 7 and thereafter. , Are held in the ON state by the self-holding coil 10. Therefore, the warning valve 8
Once lit, ignition switch (IG)
Is kept on until is turned off. Therefore, the "flickering" phenomenon of the warning valve 8 can be prevented.

FIG. 3 shows a circuit configuration of a liquid level detector 1 according to another embodiment.

The liquid level detector 1 shown in FIG. 3 has a self-holding coil 11 connected in series to the reed switch 5 of the conventional liquid level detector shown in FIG.
The self-holding contact 12 is connected in parallel with respect to. As is apparent from FIG. 3, once the reed switch 5 is turned on, the self-holding coil 12 holds the self-holding contact 12 in the on state, so that the warning valve 8 is held in the lighting state and Similar to the embodiment, the "flickering" phenomenon of the warning valve 8 can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of a liquid level detector according to an embodiment.

FIG. 2 is an electric circuit diagram of the liquid level detector.

FIG. 3 is an electric circuit diagram of a liquid level detector according to another embodiment.

FIG. 4 is a schematic side sectional view of a conventional liquid level detector.

[Explanation of Codes] 1 liquid level detector 2a tank bottom (reference surface) 5 reed switch 6 float with magnet 7 magnet 9 liquid level 10, 11 self-holding coil 12 self-holding contact

Claims (1)

[Claims] 1. A reed switch fixed to a predetermined height position from a reference surface, and a float with a magnet arranged near the reed switch so as to be movable up and down according to a liquid level. A liquid level detector, wherein the reed switch is provided with a self-holding circuit.