JP2001296174A - Oil level meter having specific gravity detection function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a change in the specific gravity of a liquid and a change in liquid surface for easily matching with the specific gravity of the liquid, for measuring the specific gravity of a float. SOLUTION: This oil level meter having a specific gravity detection function is provided with a reed switch 1 that incorporates a contact, a stem 2 that incorporates the lead switch 1, and a float 5 that incorporates a magnet 3, that travels along the stem 2 and drives the reed switch 1 and has a projection 4 made of a foamed resin for adjusting specific gravity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reed switch built in a stem, which is widely used for industrial use or home electric appliances, in which a float rises and falls according to a rise and fall of a liquid level. The present invention relates to a liquid level gauge having a function of detecting a liquid level.

[0002]

2. Description of the Related Art A liquid level gauge using a conventional reed switch (hereinafter referred to as a first prior art) uses a float lighter than the specific gravity of the liquid to be measured and floats the liquid on the liquid to be measured. When the float goes up and down as the liquid level goes up and down, the strength of the magnetic field changes and the magnetically sensitive element built in the stem is turned on / off.

[0003] Further, by detecting a change in an output signal of a magnetically sensitive element provided in the stem by the balance between buoyancy acting on the float having magnets in both the float and the stem and the repulsive force of the two magnets, A hydrometer for measuring the specific gravity of a liquid (hereinafter referred to as a second prior art) is disclosed in Japanese Patent Application Laid-Open No. 61-47536.

Japanese Patent Laid-Open Publication No. Sho 51-109438 discloses that, as shown in FIG. 3, a hollow float 15 is used to detect a specific gravity, and a magnet 13 is attached to the upper end of the float 15 via a support rod. A specific gravity meter (hereinafter, referred to as a third meter) that is disposed and puts a substance having a high specific gravity, for example, lead particles 18 at the lower end of the hollow portion of the float 15 and adjusts the buoyancy acting on the float 15 to detect a change in specific gravity or a change in liquid level. Of the prior art.) Is disclosed.

[0005]

However, in the above-mentioned first prior art, only the liquid level is detected.
It was not possible to detect a change in the specific gravity of the liquid.

The second prior art uses the repulsive force of the magnet attached to the float and the magnet installed in the stem to balance the two and detect the specific gravity. It was very difficult to take.

In the third prior art described above, in order to adjust the specific gravity to a hollow float having a magnet attached to a support rod at one end, small particles, such as lead, having a high specific gravity are put in the hollow float. Since the specific gravity is adjusted, there is a disadvantage that the operation is complicated.

An object of the present invention is to make it possible to easily adjust the specific gravity of a float to the specific gravity of a liquid to be measured, and to detect a change in the specific gravity of the liquid and a change in the liquid level with one liquid level meter. To provide a liquid level meter with a specific gravity detection function that enables the above.

[0009]

To achieve the above object, a reed switch having a built-in contact, a stem having the built-in reed switch, and a reed switch driven by moving up and down along the stem. In a liquid level meter having a float with a built-in magnet and a ring for determining the lower limit of the float movement, a float made of foam resin is provided on the float, and the float length is changed by changing the cutting length of the foam resin protrusion. Can be easily adjusted to the specific gravity of the liquid to be measured, and the change in the specific gravity of the liquid and the change in the liquid level can be detected by one liquid level meter.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a sectional view showing one embodiment of the present invention.

As shown in FIG. 1, a liquid level gauge according to the present embodiment has a reed switch 1 having a built-in contact and a function having a function of incorporating the reed switch 1 and defining the upper limit of the movement of the float 5. A float having a stem 2 having a locking structure (reference numeral 7 in FIG. 1), a magnet 3 moving along the stem 2 and driving the reed switch 1, and having a foamed resin projection 4 for adjusting specific gravity. 5 and a ring 6 provided on the lower limit side that defines a range in which the float 5 moves as the specific gravity of the liquid decreases or the liquid level decreases. The float 5 is provided with a plurality of foamed resin projections 4, and the specific gravity of the float can be easily adjusted by cutting the foamed resin projections 4 according to the specific gravity of the liquid. The material of the stem 2 and the float 5 is made of resin or non-magnetic metal.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 2 is a sectional view showing another embodiment of the present invention. In the present embodiment, as shown in FIG. 2, the magnetic force of the magnet is reduced by arranging the ferromagnetic material 7 around a reed switch whose contact is turned on / off as the float 5 containing the magnet 3 moves up and down. This can be transmitted to the reed switch via the ferromagnetic material 8, and a stable operation can be performed.

[0013]

As described above, according to the present invention, in a liquid level meter using a reed switch, a protrusion for adjusting specific gravity is provided on a resin float foamed on a float containing a magnet, and the protrusion is cut. By changing the length of the float, the float can be easily adjusted to the specific gravity of the liquid.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid level gauge showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a liquid level gauge showing another embodiment of the present invention.

FIG. 3 is a cross-sectional view for explaining a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reed switch 2 Stem 3 Magnet 4 Projection made of foam resin 5 Float 6 Ring 8 Ferromagnetic substance

Claims (3)

[Claims] 1. A detecting magnet for providing a predetermined magnetism, a float incorporating the magnet, and the float moving up and down with the liquid level up and down, and detecting the approach of the detecting magnet to open and close a contact. In a liquid level gauge having a hollow stem with a built-in reed switch, a float made of foamed resin is provided on the float, and the density of the float is detected by changing the cutting length of the foamed resin protrusion. A liquid level meter with a specific gravity detection function, which is adapted to the specific gravity of the liquid. 2. The stem according to claim 1, wherein the stem has a locking structure that defines an upper limit of the float movement, and a ring that defines a lower limit of the float movement is provided. Liquid level meter with specific gravity detection function. 3. The liquid level meter with a specific gravity detection function according to claim 1, wherein a ferromagnetic material is disposed inside the stem so as to cover the reed switch.