JPS60219518A - Bath boiler with water level detector - Google Patents

Abstract

PURPOSE:To obtain a water level detector having no mechanically movable part, by constituting the same so as to detect the change in electrostatic capacity corresponding to a water level. CONSTITUTION:Electrode rods 9a, 9b are opposed in a flat plate like shape and constituted so as to largely take the electrostatic capacity between both of them. By utilizing that the electrostatic capacity between two electrode rods 9a, 9b is changed corresponding to the constitutional ratio of air and water in a communication pipe 5, a water level can be calculated. That is, when the frequency of the output pulse from an oscillator 7 using the electrostatic capacity between two electrode rods 9a, 9b as a time constant element is set to (f) and the water level of the communication pipe 5 measured from the lowermost ends of the electrode rods 9a, 9b to (h), the relation shown by the drawing is obtained. Hereupon, when measuring frequency is set to f1, the water level of the communication pipe 5 at this time comes to h1. Therefore, if planning is performed so as to bring the height from the bottom of a bathtub to the lowermost ends of the electrode rods 9a, 9b to h0, the water level H of the bathtub 2 is calculated by H=h0+h1.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a bathtub with a water level detection device.

Conventional configuration and problems Conventional water level detection devices are generally of the mechanical contact type using floats, but if used once again to detect the water level in a bath, there is a risk of malfunction due to hot water scale. etc., reliability was not sufficient.

OBJECTS OF THE INVENTION The object of the present invention is to provide a device that eliminates the above-mentioned drawbacks, that is, a bathtub equipped with a water level detection device without mechanically moving parts by means of detecting changes in capacitance corresponding to the water level.

Structure of the Invention The present invention connects a heat exchanger provided in a bathtub body to a bathtub via a water pipe, and provides a communication pipe extending upward in a shunt to the water pipe on the second side. Inside the communication pipe, two electrode rods are installed facing each other and are electrically insulated with a -7. The water level in the bath is detected by converting and dividing this.

DESCRIPTION OF EMBODIMENTS FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. Normally, water in the bathtub 2 is provided in the bathtub body 1 through a water pipe 4b at the bottom (1!!I). is sent to the heat exchanger 3, where it is heated by the burner 6, and then passed through the upper water pipe 4a.
f and return to the bathtub 2 again.

A communication pipe 5 is provided in the bathtub body 1 and is shunted so as to extend upward from the second side water pipe 4a.
Inside, two electrode rods 9a and 9b are provided facing each other, and their terminals are connected to the oscillator 7.

As shown in FIG. 2, the surfaces of the electrode rods 9a and 9b are coated with electrically insulating coatings 10a and 10b made of Teflon, epoxy resin, etc.
It is electrically insulated from the water in the bathtub 2. In addition, spacers 1 are provided at the upper and lower parts of the electrode rods 9a and 9b.
1a and 11b are provided, and the wall surface of the communication tube 5 and the electrode rod 9a
, 9b and the distance between the electrode rods 9a and 9b is maintained.

The electrode rods 9a and 9b are arranged to face each other in a flat plate shape, as shown in FIG. 2, so that a large capacitance can be obtained between them.

In such a configuration, the water level can be adjusted by utilizing the fact that the capacitance value between the two electrode rods changes depending on the composition ratio of air and water in the communication pipe 5. That is, the oscillator 7 uses the capacitance of the two electrode rods 9a and 9b as a time constant element.
Assuming that the frequency of the output pulse from the electrode rods 9a and 9b is f and the water level of the communicating tube opened from the lowest end of the electrode rods 9a and 9b is h, a relationship as shown in FIG. 3 is obtained. Now, if the measured frequency is fl, the water level in the communication pipe 5 at that time is January.

Therefore, if the height from the bottom of the bathtub 2 to the lowest end of the electrode rods 9a, 9b is designed as ho, the water level H of the bathtub 2 that can be claimed can be obtained by the following equation.

H=hO+h.

Also, when the water level in the bathtub 2 is below the height of the upper water pipe 4a, the burner 6 cannot be burned.
It can be said that there is no need to detect water levels below this. Therefore, by configuring the electrode rods 9a, 9b so that the lowest end position 8 is at the height of the upper water pipe 4a, necessary water level information can be obtained using the short communication pipe 5 and the electrode rods 9a, 9b. Can be done.

In the above description, an example was shown in which the frequency of the output pulse of the oscillator 7 is measured in water level detection, but the present invention is not limited to this, and includes means for measuring the width of the output pulse.

Effects of the Invention As described above, according to the present invention, a simple structure is provided that includes a communication pipe shunted from the water pipe, two electrode rods sealed with an electrically insulating material, and an oscillator inside the communication pipe. The configuration can detect the water level in the bathtub, and by detecting that the water level in the bathtub is below the minimum level,
It has the effect of controlling combustion so that the bath kettle does not run dry.

Further, according to the present invention, since the water level detection mechanism can be configured without mechanically moving parts, it has the effect of being excellent in reliability against hot water scale and the like.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a bath pot with a water level detection device showing one embodiment of the present invention, Fig. 2 a and b are detailed sectional views of the same part, and Fig. 3
The figure shows the relationship between water level and oscillation frequency. 1... Bath pot body, 2... Bathtub, 3...
... Heat exchanger, 4a, 4b ... Water pipe, 5.
... Communication tube, 7... Oscillator, 9a, 9b...
...electrode rod. Name of agent: Patent attorney Toshio Nakao and 1 other person ≠ Atsuzuka

Claims (1)

[Claims] A water pipe that connects the heat exchanger and the bathtub installed inside the bathtub body, a communication pipe that is shunted upward from this water pipe, and an electrically sealed pipe that is installed inside this communication pipe. A bathtub with a water level detection device comprising two electrode rods facing each other and an oscillator connected to the two electrode rods.