JPS6059494B2 - Automatic shutdown device for the heat source when the bath boils - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an outer pot circulation type bath, and when the temperature of the water in the bathtub rises to a desired appropriate temperature and reaches a boiling state, this is detected, and combustion gas and The present invention relates to a device for automatically stopping a heat source to which electric current is supplied.

Traditionally, it has been possible to detect when a bath is boiling and use an alarm to artificially shut off the gas, but this has the inconvenience of requiring a person to operate the gas valve or switch for this purpose. Therefore, some devices are used in which a timer is used to set a time in advance and the gas etc. are automatically shut off when the time elapses.

The set time depends on the amount of water in the bathtub, the initial water temperature, and the desired boiling temperature, so if you stir the water in the bathtub when the timer goes off, you will notice that it is considerably colder than the appropriate temperature for bathing. It's easy to get hot or too hot and have to add a lot of water.

Therefore, it is already considered that by detecting the temperature of the heated hot water using a temperature sensor, when the detected temperature reaches a set temperature, a predetermined control device is activated, thereby shutting off the combustion gas, etc. It is being

In this case, there is a problem as to where the temperature sensor should be installed, and many ideas have been proposed regarding this point. When the temperature sensor detects that the set temperature has been reached and the heat source is shut off, when the hot water is stirred, there is a considerable error between the boiling temperature and the set temperature. Therefore, it is extremely difficult to shut off the heat source at an appropriate temperature, and satisfactory results have not been obtained.

The present invention attempts to provide a solution to the above problem.
Describing this in detail with a drawing, as is known, a bathtub 1 and a bathtub 2 adjacent thereto are in communication via an upper circulation pipe 3 and a lower circulation pipe 4, and are connected via a supply pipe 5. The combustion gas 7 supplied to the heat source section 6 of the bathtub 1 can be cut off by an on-off valve 8.

Of course, the heat source section 6 may be an electric heater or the like instead of gas.

In the present invention, one or more pairs of temperature sensors 9, 9' are provided inside the lower circulation vibrator 4. At this time, as shown in FIG. 10 and 1'' in the lower half, respectively.Then, temperature sensors 9 and 9'' are shown by solid lines in FIGS. 1 and 2.
are on the vertical dividing line Y, respectively, and 10 and 1' in the upper and lower halves, respectively.
The temperature sensors 9, 9'' shown by chain lines in FIG. 2 are installed at the top and bottom of the screen, and the temperature sensors 9 and 9'' shown by chain lines in FIG. As shown in A, multiple pairs of temperature sensors 9, 9'', 9'', 9'''', etc. are arranged in series on the vertical dividing line Y of the same vibrator 4, and It may be arranged above.

As shown in FIG. 1, the temperature sensors 9 and 9'' are supplied with the water temperature detection output as an input to a control device 11 that can set a predetermined temperature. The on-off valve 8 is closed by an arbitrary means, but the above-mentioned detection output is the detection output by the temperature sensor 9 in the upper half 10 of the lower circulation vibrator 4 where the hot water temperature rises and changes at an early stage. A serial output is used between the output and the detection output from the temperature sensor 9'' in the lower half 1'' where the hot water temperature rises and changes with a delay.

An example of how to obtain such a series output is shown in FIG.
1 and R2 are connected in series, a correction resistor R is connected in parallel to this, and a temperature setting variable resistor VR is connected in series with the resistor R. The terminal t is connected to the power supply, and the terminals t'' and t are connected in series.
The detection output is derived from ``'', and the correction resistor R is used so that the voltage output at both ends of R is close to linear. It also has the advantage of being able to use one that changes linearly and making the temperature setting scale equal. Curve A in Fig. 5 shows how the detection output of the hot water temperature by only the solid line upper temperature sensor 9 shown in Fig. 2 changes over time, and the curve A shows how the temperature rises and changes over time. Temperature sensor 9 below the solid line
'' represents the temperature increase change detected, curve C represents the temperature rise change detected by the temperature sensor 9 indicated by the chain line in Figure 2, and straight line 2 represents the temperature change detected by stirring the hot water in bathtub 2 to make it uniform. This is the temperature of the water.

In the present invention, instead of using the detection output of one temperature sensor as shown in curves A, C and C above, a pair or more series outputs are used as input to the control device 11 as described above. Curve E represents the arithmetic average output of the detection outputs of the temperature sensors 9 and 9'' indicated by curve A and mouth.

So, first of all, if we consider curve A, the initial water temperature of hot water is T.

When you start boiling a bath from this state, there is initially little change in the water temperature detection output of the temperature sensor 9 over time, but
As shown in the figure, the temperature rises relatively early, the slope of the curve becomes quite large, and then the temperature rises in a straight line with a substantially positive slope. When boiling a bath in this figure, the actual water temperature required is in the range T1 to T3, and therefore the time is in the range t1 to T3, but the curve A at time t1 is The gradient is quite large, whereas the second
In the case of curve C obtained by the temperature sensor 9 in the upper half 10 shown by the chain line in the figure, the slope is decreasing), a temperature increase change with a considerable slope is also obtained.

However, the temperature sensor 9'' shown by the solid line in the lower half 1'' shows almost no temperature change not only at time but also at time t1'' as shown by the curved line, and therefore the detection output of the temperature sensor 9'' is obtained. In this case, the water temperature T1~T
It becomes impossible to set the temperature for ,''.Therefore, when curve A is reached, and if we examine it further, it becomes time! After that, it becomes a straight line 2, that is, it is well proportional to the average temperature change when hot water is stirred, but the temperature changes over time. The proportional relationship does not hold in the relatively early period from t1 to T2.

Therefore, by utilizing the series output as shown in curve E as in the present invention, a proportional relationship substantially parallel to straight line 2 can be obtained, and by controlling the heat source section 6 using the series output, the following is achieved. You can get the following effect.

Curve A in FIG. 6 shows the error between the temperature set by the control device 11 and the actually obtained temperature during stirring due to changes in the initial water temperature L, using only the temperature sensor 9 and keeping the water amount W constant. In this case as well, the above error can be made quite small, but as shown in the figure, at 0°C and L<3
At 0℃, the error is about ±4℃, so in cold regions L will be close to 0℃, and in warm regions L will be close to 30℃, and in general, the optimal temperature for bathing is around 42℃. When considering that, it cannot be said that it is completely satisfactory.

On the other hand, when control is performed using the serial output of temperature sensors 9 and 9'' shown by the solid line in Fig. 2, the characteristics shown at the beginning of the simultaneous curves are obtained, and the boiling temperature is reduced over an extremely wide range of initial water temperatures. It was possible to suppress the temperature error to less than ±1°C.

Next, curve A in FIG. 7 shows how the above error changes when the temperature sensor 9 is placed in the upper half 10 and the mounting position angle θ is changed, where θ=90. 'C
The error gradually increases as the value approaches , and when θ becomes larger than that, a suddenly large error occurs.

On the other hand, when the temperature sensors 9, 9'' are provided in the upper half 10 and the lower half 1'' and their serial outputs are used as in the present invention, their installation is as shown by the curved opening in the same figure. Even if the position angle .theta. is changed, the error does not become large, and therefore there is a degree of freedom in the mounting position of the temperature sensors 9, 9''.

Furthermore, in FIG. 8, curve A shows the fluctuation of the error due to changes in the water amount W when Ts = - constant and only the temperature sensor 9 shown by the solid line in FIG. 2 is used. As shown in the figure, W=110e and the error is C with about -6.

Therefore, when one temperature sensor 9 is used, there remains a problem that the error becomes large when trying to boil water while saving water in a bath. By using the sensors 9 and 9'', a characteristic similar to the curved line in the same figure was obtained, and errors due to changes in the amount of water W could be greatly reduced.

Note that a temperature element such as a thermistor or a diode can be used as the temperature sensor, and a plurality of temperature elements may be built into the same sensor.

As described above, the present invention provides the
one or more temperature sensors 9,9'' are provided at 0,1'', respectively;
A control device 11 is provided which is activated by the serial detection output of the water temperature from these temperature sensors, and the heating by the heat source section 6 can be cut off according to the set value of the device, so that It is possible to utilize a hot water temperature change curve that is extremely similar to straight line 2, and as a result, the above-mentioned 6th, 7th, and 8th
Various improvement effects as illustrated in the figures can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of a bath equipped with an automatic stop device according to the present invention, Fig. 2 is an explanatory diagram showing the mounting position of the temperature sensor, and A and mouth in Fig. 3 are at the same mounting position. 4 is a wiring diagram of an example of a circuit that can be used to obtain the serial output of a temperature sensor, FIG. 5 is a diagram showing changes in water temperature detected by the temperature sensor over time, and FIG. 6 is a diagram showing other embodiments. is a chart showing the error between the set temperature and the boiling water temperature with respect to the initial water temperature Ts of hot water, Fig. 7 is a chart showing the same error with respect to the mounting position angle of the temperature sensor 00, and Fig. 8 is a chart showing the same error with respect to the water volume W of hot water. This is a chart showing the 1...bath pot, 2...bathtub, 3...
...Upper circulation vibe, 4...Lower circulation vibe, 6...Heat source section, 9,9''...Temperature sensor, 10...Top Inside half, 10″...
- Inside the lower half, 11...control device.

Claims (1)

[Claims] 1 The hot water in the bathtub is heated by a heat source, and the heated water is circulated by convection through an upper circulation pipe and a lower circulation pipe that connect the bathtub and the bathtub, thereby boiling the water in the bathtub. In such a bath, one or more temperature sensors are provided in each of the upper half and the lower half of the lower circulation pipe, and a control device is provided that is operated by the serial detection output of the water temperature from these temperature sensors. . A device for automatically stopping a heat source when a bath is boiling, characterized in that heating by the heat source can be cut off depending on a set value of the device.