JPS60219516A - Bath boiler with water level detector - Google Patents

Abstract

PURPOSE:To make it possible to control combustion so as to prevent a bath boiler from heating the bath without water, by detecting that the water level in a bathtub is a min. level or less by a simple constitution equipped with a pressure detection means. CONSTITUTION:The water in a bathtub 2 is sent to the heat exchanger 3 in a main body 1 through a lower side water passing pipe 4b and heated therein by a burner before again returned to the bathtub 2 through an upper side water passing pipe 4a. A communication pipe 5, which is branched so as to be extended upwardly, is provided to the water passing pipe 4a within the main body 1 and a tube 7 is inserted into the leading end part 5b thereof while the pressure detection means 8 is connected to the leading end of said tube 7 so as to be provided in the main body 1. Hereupon, by utilizing such a phenomenon that the air pressures of the air sump part 5a in the communication pipe 5, the interior of the tube 7 and the pressure receiving chamber 8b of the detection means 8 are changed by the difference (h) of the water level in the bathtub 2 and that in the communication pipe 5, the water level in the bathtub is calculated to prevent the heating of the bath without water and combustion can be controlled.

Description

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

Conventional configuration and its problems Conventional water level detection devices are generally of the mechanical contact type using floats, but when used to detect the water level in a bath, there is a risk of malfunction due to hot water scale, making them unreliable. There wasn't enough sex.

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 non-contact type water level detection device using means for detecting air pressure proportional to the water level in the bathtub.

Structure of the Invention The present invention connects a heat exchanger provided in a bathtub main body to a bathtub via a water pipe, and provides a communication pipe extending upward in a shunt to the upper water pipe, and also connects the bathtub with the heat exchanger provided in the bathtub body through a water pipe. A pressure sensing means is installed at the tip of the pipe either directly or through a tube, and the water level of the bath can be determined by measuring the pressure of the air inside the communicating pipe, which changes depending on the water level of the bath. This is to detect.

DESCRIPTION OF EMBODIMENTS FIG. 1 is a schematic +111 diagram showing an embodiment of the present invention. Normally, water in the bathtub 2 passes through a water pipe 4b at the bottom 11111 and is heated to a temperature provided in the bathtub body. After being sent to the exchanger 3 and heated there by the burner 6, it passes through the upper water pipe 4a and returns to the bathtub 2.

In the upper water pipe 4a, a communication pipe 5 is provided in the bathtub body 1 and is branched so as to extend in one direction.
The distal end portion 5b has a structure into which a duplex 7 is inserted, as shown in FIG. By using a flexible material such as vinyl chloride for the tube 7, it is possible to install the pressure detection means 8 connected to the tip of the tube at any desired location within the bathtub body 1.

As the pressure detection means 8, a strain gauge type made of a silicon semiconductor or a capacitance type with a ceramic tA diaphragm as one electrode plate may be considered.
In the embodiment, the pressure received by the rubber diaphragm 8a is balanced by the spring 8c, and the mechanical displacement (Δ
A pressure sensing means 8 of a type that converts the signal I) into an electrical signal was used. The diaphragm 8a receives pressure, and the displacement phase (△X) of the diaphragm plate 8b is determined by the spring 8c.
d, and finally an electrical signal proportional to the pressure is obtained. A conceivable configuration of the mechanical-electrical converter 8d described in 1fX is such that the inductance of the winding changes with the amount of displacement of the displacement rod 8e made of a magnetic material.

In such a configuration, it is assumed that the difference between the water level in the bathtub 2 and the water level in the communication pipe 5 changes the air pressure in the air pocket 5a in the communication pipe 5, in the duplex 7, and in the pressure receiving chamber 8f of the pressure detection means 8. You can use it to raise the water level in the bath.

That is, atmospheric pressure is P. , the density of water is ρ, and the spring constant of ノ<NE8C is K, then the air pressure P1 of the air pocket 5a in the communication pipe 5 is expressed by the following equation.

P 1-” P □+ρg h -il+However, g is
The gravitational acceleration coefficient is approximately 9.13, m/s2. On the other hand, when the spring 8C is displaced by Δ, the pressure P2 that the diaphragm 8a receives from the spring side is determined by the following equation.

P 2 ''' P ( ) + K ' △ Knee (2) Since the pressures shown in equations (1) and (21) above are balanced in the diaphragm 8a, if P1=P2, the following equation holds.

pgh=ni・△x (3: In other words, since ρ and g are proportional constants, the displacement Δ
It is shown that the difference in water level between the bathtub 2 and the communication pipe 5 can be detected by using Kokichi, which measures the amount of air in the city corresponding to the construction.

On the other hand, the water level change amount Δh in the communication pipe 5 is very small compared to the water level difference in the bathtub 2 and the communication pipe 5, and can be almost ignored. water level h
The water level H1l-1 of the bathtub 2 can be determined by the following formula.

H=h-t-h.

Effects of the Invention As described above, the present invention has a simple structure in which a communication pipe is branched from a water flow pipe and a pressure detection means is provided at the tip of the communication pipe directly or through a pipe such as a tube. By detecting that the water level in the bathtub is below the minimum level, combustion can be controlled so that the bathtub does not run dry.

Furthermore, according to the present invention, since the water level detection mechanism is constructed of a water level non-contact type, 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 surface showing an embodiment of the present invention, and Fig. 2 is a detailed diagram of the same part i (+11bo 1fii).
It is 171. 1... Bathtub body, 2 - Bathtub, 3... Heat exchanger,
4a, 4b: Water pipe, 5: Communication pipe, 7: Tube, 8: Pressure detection means.

Claims (1)

[Claims] A water pipe that connects the heat exchanger installed in the bathtub body and the bathtub, a communication pipe that is shunted in one direction from this water pipe, and a water pipe that connects the heat exchanger installed in the bathtub body to the bathtub; A bathtub equipped with a water level detection device and a pressure detection means connected via a pipe.