JPH10295771A - Control method for preventing excess temperature rise in electric sauna bath and device using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize a temperature rise in a normal use condition and also use a low-priced material by lowering the highest use temperature of a heater and its surroundings. SOLUTION: When a temperature to be detected by a temperature detection sensor is above a first set temperature level (120 deg.C) (No.22), a power to be supplied to a heater is decreased (No.23). After saving on the power in (No.23), the power is increased (No.26) when the detected temperature is below a second temperature level (100 deg.C) (No.25) before the lapse of a set time. After the power is decreased in (No.23), the detected temperature is not below the second set temperature (No.27), even when the set time (10 minutes) is past, the power supply is shut off to set the device in a standby state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for controlling an excessive temperature rise of an electric sauna bath.

[0002]

2. Description of the Related Art Conventionally, a temperature fuse, for preventing excessive temperature rise in a bathroom (sauna storage) of an electric sauna bath, has been used.
A temperature detection sensor such as a thermostat or a thermistor is used.

[0003] If there is an abnormal temperature rise in the sauna room, the temperature detection sensor detects it, and the overheat prevention control device operates to stop supplying power to the heater, thereby maintaining safety. .

When the interior of the sauna is cold, for example, when the power is turned on for use of an electric sauna bath, the maximum power is supplied to the heater. It will be much higher than the set temperature.

[0005] However, when a planar heating heater or the like is used as the heater, the temperature detection sensor is often directly attached to the surface of the heater. Then, the temperature detection sensor detects a considerably high temperature even during normal operation.

Therefore, conventionally, even when the temperature detection sensor detects such a high temperature, the operating temperature of the overheating prevention device is variously undefined so that the overheating prevention control device does not operate. It is set quite high with a good margin.

For example, as shown in FIG. 8B, when the maximum surface temperature of the heater is about 110 ° C., the operating temperature of the overheat prevention device is 140 ° C., which is about 30 ° C. higher than that.
Is set to

[0008]

Then, the temperature rise up to the operating temperature set in the overheat prevention control device is as follows.
It will always be repeated in normal use. That is, in the normal use of the electric sauna bath, the temperature of the heater and its surroundings rises to about 140 ° C., and this is repeated.

Therefore, conventionally, it has been necessary to increase the heat resistant temperature of the heater and its surrounding members to 140 ° C. or higher. Therefore, it is necessary to use an expensive material having high heat resistance, which has been a factor of cost increase.

If the operating temperature of the overheating prevention device is set low, for example, the thermal fuse is frequently blown and must be replaced each time, and the thermostat repeatedly turns on and off. Therefore, the life is extremely shortened. Therefore, maintenance becomes troublesome and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to reduce the temperature rise during normal use and to reduce the maximum use temperature of the heater and its surroundings to use an inexpensive material. An object of the present invention is to provide a control method and an apparatus for preventing overheating of an electric sauna bath which are enabled.

[0012]

According to a first aspect of the present invention, there is provided a method of heating a bathroom by supplying power to a heater and controlling the power in accordance with a temperature detected by a temperature detection sensor. An overheating prevention control method for an electric sauna bath configured as described above, wherein a first step of reducing the electric power when a temperature detected by the temperature detection sensor is equal to or higher than a first set temperature. ,
After reducing the power in the first step, when the temperature detected by the temperature detection sensor becomes equal to or lower than a second set temperature before a set time elapses,
After the power is reduced in the second step of increasing the power and in the first step, the temperature detected by the temperature detection sensor does not fall below the second set temperature even after a set time has elapsed. Sometimes stopping the power supply.

[0013] The apparatus according to the second aspect of the present invention heats the bathroom by supplying electric power to the heater,
An overheat prevention controller for an electric sauna bath configured to control the electric power according to a temperature detected by a temperature detection sensor, wherein the temperature detected by the temperature detection sensor is a first set temperature. A first control unit for reducing the power, a temperature detected by the temperature detection sensor before a set time elapses after the first control unit reduces the power. A second control means for increasing the power when the temperature becomes equal to or lower than a second set temperature; and detecting the temperature even after a set time has elapsed after the power has been reduced by the first control means. A third step of stopping the power supply when the temperature detected by the sensor does not fall below the second set temperature.
And control means.

In the apparatus according to the third aspect of the present invention, the first
Is set higher than the maximum surface temperature of the heater, and the second set temperature is set lower than the maximum surface temperature of the heater.

According to a fourth aspect of the present invention, there is provided an apparatus having full-half-wave switching control means for switching between half-wave rectification and full-wave rectification of an AC power supply for reducing or increasing power supplied to the heater. It becomes.

The apparatus according to a fifth aspect of the present invention heats the bathroom by supplying electric power to the heater,
An overheat prevention control device for an electric sauna bath configured to control the power according to a temperature detected by a temperature detection sensor, for reducing or increasing power supplied to the heater, Full-wave switching control means for switching between half-wave rectification and full-wave rectification of the AC power supply, and the temperature detection sensor detects the full-wave mode for supplying the maximum power by full-wave rectification to the heater. A first control unit that switches the power to half-wave rectification when the temperature becomes equal to or higher than a first set temperature; and a set time after switching the power to half-wave rectification by the first control unit. When the temperature detected by the temperature detection sensor becomes equal to or less than a second set temperature before the elapse,
Second control means for switching the power to full-wave rectification, and after the power is switched to half-wave rectification by the first control means, a temperature detected by the temperature detection sensor even after a set time has elapsed. A third control unit for stopping the supply of the electric power when the temperature does not fall below the second set temperature; and a temperature detected by the temperature detection sensor in an adjustment mode for supplying the adjusted electric power to the heater. And a fourth control unit for stopping the supply of the electric power when the temperature becomes equal to or higher than the first set temperature.

The operation of the present invention will be described with reference to the drawings.

The first set temperature T1 is, for example, 120 ° C.
The second set temperature T2 is set to, for example, 100 ° C., respectively. The maximum temperature in the sauna room is, for example, 70 ° C., and the maximum surface temperature of the heater reaches, for example, 110 ° C.

When the power is turned on, for example, the planar heater 3
1 is supplied with electric power by full-wave rectification, and the inside of the sauna room is heated with full power. When the temperature To detected by the thermistor 32, which is a temperature detection sensor, reaches the first set temperature T1, the switching signal Kr forcibly switches from full-wave rectification to half-wave rectification, and the power due to half-wave rectification becomes planar. It is supplied to the heater 31. Thereby, the sheet heater 31
Surface temperature decreases.

After switching from full-wave rectification to half-wave rectification, when the temperature To detected by the thermistor 32 falls to the second set temperature T2 within the set time t1,
Normal operation is considered, and the half-wave rectification is returned to full-wave rectification by the switching signal Kr. That is, the power supplied to the planar heater 31 is returned from the half-power state to the original full power state.

On the other hand, when the temperature To detected by the thermistor 32 does not decrease to the second set temperature T2 even after the set time t1 has elapsed after switching from full-wave rectification to half-wave rectification, It is considered that some trouble has occurred, and the switching signal Kr causes the sheet heater 31 to fail.
Power supply to the power supply is forcibly stopped.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view showing a cross section of a part of an electric sauna bath 1 according to the present invention, and FIG.
FIG. 3 is an enlarged sectional view of the AA part shown in FIG.

As shown in FIGS. 1 and 2, the electric sauna bath 1 includes a rectangular parallelepiped main body 11 and a door 12. Two planar heaters 31a and 31b are embedded in the side wall of the main body 11.

In FIG. 3, the main body 11 includes a structural member 21.
And a heat insulator 22, and a planar heater 31 a is attached to the surface of the heat insulator 22. A thermistor 32a as a temperature detection sensor is directly attached to the surface heater 31a at a substantially central position on one surface thereof, and a lead wire 33 is drawn out. The other surface of the planar heater 31a, that is, the inner surface of the sauna box, is covered with a cover 34 made of cloth or the like.

Therefore, since the resistance value of the thermistor 32a changes immediately following the temperature change of the sheet heater 31a, the surface temperature of the sheet heater 31a can be detected without a time delay.

The whole or a part of the planar heaters 31a and 31b is described as "the planar heater 31" and the thermistor 32 is used.
All or a part of a and 32b may be described as "thermistor 32".

FIG. 4 is a block diagram showing a circuit of the control device 3 of the electric sauna bath 1.

In FIG. 4, the control device 3 includes a constant current source 5
1, an amplification circuit 52, a microcomputer 53, a power control circuit 54, an operation panel 55, and the like.

The constant current source 51 is for supplying a constant current to the thermistor 32. The thermistor 32 changes its resistance value according to the temperature and outputs a voltage signal Vs. The voltage signal Vs is the temperature T detected by the thermistor 32.
corresponding to o. The amplifier circuit 52 amplifies the voltage signal Vs output from the thermistor 32 and adjusts the voltage level.

The microcomputer 53 includes an amplification circuit 5
A / D converter for converting a voltage signal Vc output from 2 into a digital signal, an input / output port for inputting other signals and outputting a signal or data for control, a CPU, and storing programs and data for control ROM and ROM for temporarily storing data or programs.
AM, etc.

The microcomputer 53 controls the planar heater 31 based on the setting or command signal from the operation panel 55 and the temperature To detected by the thermistor 32 to perform normal temperature control and overheat prevention control. A switching signal Kr for switching the supplied power is output.

The power control circuit 54 includes a full-wave rectifier circuit, a half-wave rectifier circuit, a relay for switching between full-wave rectification and half-wave rectification, and a sheet heater 31a. , 31b for switching between parallel connection and series connection, and a temperature fuse.

In the power control circuit 54, based on the switching signal Kr output from the microcomputer 53, switching control of supply and stop of electric power to the planar heater 31, parallel connection and serial connection of the planar heaters 31a and 31b. Control and a combination of switching between full-wave rectification and half-wave rectification of the AC power supply, and control for preventing excessive temperature rise.

When the planar heaters 31a and 31b are connected in parallel, a predetermined voltage is applied to the planar heaters 31a and 31b. On the other hand, when connected in series, half of the predetermined voltage is applied to each of the planar heaters 31a and 31b.
The power supplied to a and 31b is about one-fourth of that in the case of parallel connection.

When power is supplied to the planar heater 31 by full-wave rectification, the rated power is supplied to the planar heater 31. On the other hand, when power is supplied by half-wave rectification, power that is approximately half of the rated power is supplied, and the heating power of the sauna room is reduced by half.

Therefore, when the planar heaters 31a and 31b are connected in parallel and supplied with electric power by full-wave rectification, the planar heaters 31a and 31b heat the sauna room with full power. In other cases, the electric power adjusted according to the set temperature is supplied to the planar heaters 31a and 31b.

The operation panel 55 includes a switch for turning on and off the power of the electric sauna bath 1, a switch for setting the temperature of the sauna chamber in a plurality of stages, and a thermistor 32.
And an indicator light for displaying the operation state of the control device 3 are provided.

Next, control for preventing excessive temperature rise will be described.

The contents of the overheat prevention control are described on the operation panel 5.
5 depends on the state of the temperature setting. That is, the excessive temperature rise prevention control includes a full-wave temperature excess rise prevention control in the full-wave mode and an adjusted temperature excess rise prevention control in the adjustment mode.

In the full-wave mode, for example, as in the case where “high temperature” is set by the operation panel 55,
In this mode, the sauna chamber is heated with full power by supplying power by full-wave rectification to 1a and 31b.

The adjustment mode is a power supply mode other than the full-wave mode. For example, “low temperature” by the operation panel 55
Is set, power is supplied to each planar heater 31 by half-wave rectification for normal temperature control, or power is supplied to the planar heaters 31a and 31b connected in series. .

In the present embodiment, the first set temperature T1 and the second set temperature T2 are set to 120 ° C. and 100 ° C., respectively, in the control device 3 for the overheat prevention control. The maximum temperature in the sauna room is 70 ° C., and in order to obtain the maximum temperature of 70 ° C., the surface maximum temperature of the sheet heater 31 usually reaches 110 ° C.

First, the full-wave temperature rise control will be described.

When the power is turned on by the operation panel 55, electric power by full-wave rectification is supplied to the planar heater 31 from the electric power control circuit 54, and the inside of the sauna chamber is heated with full power.

The temperature To detected by the thermistor 32
When the temperature reaches the first set temperature T1, the switching signal Kr is used to forcibly switch from full-wave rectification to half-wave rectification, and power by half-wave rectification is supplied to the sheet heater 31. That is, the power supplied to the planar heater 31 is forcibly reduced by half. As a result, the surface temperature of the planar heater 31 decreases.

After switching from full-wave rectification to half-wave rectification, if the temperature To detected by the thermistor 32 falls to the second set temperature T2 within the set time t1,
Normal operation is considered, and the half-wave rectification is returned to full-wave rectification by the switching signal Kr. That is, the power supplied to the planar heater 31 is returned from the half-power state to the original full power state.

For example, 10 minutes is set as the time t1. If the time is about 10 minutes, there is surplus heat in the sauna compartment, so even if the power supplied to the planar heater 31 is reduced by half, the temperature in the sauna compartment does not change much, and the user in the sauna compartment is reduced by half. I do not notice that it was switched to wave rectification. Note that an appropriate time other than 10 minutes may be set as the time t1.

On the other hand, when the temperature To detected by the thermistor 32 does not decrease to the second set temperature T2 even after the set time t1 has elapsed after switching from full-wave rectification to half-wave rectification, It is considered that some trouble has occurred, and the switching signal Kr causes the sheet heater 31 to fail.
Power supply to the power supply is forcibly stopped. At the same time, a warning lamp is lit on the operation panel 55. This serves as an over-temperature prevention control device.

After switching from half-wave rectification to full-wave rectification, if the temperature To detected by the thermistor 32 again reaches the first set temperature T1, the above-described control is repeated.

Next, the control for preventing the temperature from excessively rising will be described.

In the control for preventing the temperature from excessively rising, the temperature To detected by the thermistor 32 is equal to the first set temperature T.
It is monitored whether 1 has been reached. First set temperature T
If it does not reach 1, normal temperature control is continued.
When the temperature reaches the first set temperature T1, it is considered that some trouble has occurred, and the supply of power to the planar heater 31 is forcibly stopped by the switching signal Kr.

Next, the over-temperature prevention control will be described with reference to a flowchart.

FIG. 5 is a flowchart showing the overall procedure of the overheating prevention control, FIG. 6 is a flowchart showing the procedure of the full-wave temperature overheating prevention control, and FIG. 7 is a flowchart showing the procedure of the regulating overheating prevention control. is there.

In FIG. 5, when the temperature To detected by the thermistor 32 immediately after the power is turned on is 100 ° C. or higher (No in # 11), an error is displayed as an abnormality of the thermistor 32. (# 15), it immediately enters the standby state (# 16). The standby state is
This is a state in which the supply of power to the planar heater 31 is stopped, and the planar heater 31 does not perform any heating. The error display is performed for, for example, about 10 seconds.

When the temperature To is equal to or lower than 100 ° C. (Yes in # 11), when the operation is in the full-wave mode, full-wave temperature overheating prevention control is performed (# 13). The control for preventing the temperature from excessively rising is performed (# 14).

In FIG. 6, first, it is determined whether or not the state is a forced half-wave rectification (forced half-wave state) (# 21).

When the state is not the forced half-wave state (No in # 21), the temperature To detected by the thermistor 32 becomes 12
When the temperature is equal to or lower than 0 ° C. (first set temperature T1) (# 2
(No at 2), that state is maintained. Temperature To is 120
If the temperature is equal to or higher than C (Yes in # 22), the mode is forcibly switched to half-wave rectification (# 23).

In the forced half-wave state (Yes in # 21), the detected temperature To is 100 ° C. (second set temperature T2) within 10 minutes after that (No in # 24).
When it becomes below (Yes in # 25), the state of the forced half-wave is released, and the state of the full-wave rectification is returned (# 26).

When 10 minutes have passed since the forced half-wave state (Yes in # 24), an error is displayed because some trouble has occurred (# 27), and the apparatus enters the standby state (# 28). .

In FIG. 7, when the temperature To detected by the thermistor 32 is equal to or lower than 120 ° C. (first set temperature T1) (No in # 31), the state is maintained. When the temperature To becomes 120 ° C. or more (# 31
Yes), an error is displayed because some trouble has occurred (# 32), and the system enters the standby state (# 33).

The temperature To detected by the thermistor 32 is read into the microcomputer 53 at intervals of, for example, 10 to 20 seconds, and the above-described processing is performed at each timing.

The processing of the above steps # 22 and # 23 is applied to the first step and the first control means in the present invention, and the processing of steps # 25 and # 26 is applied to the second step and the second control means in the present invention and the processing of the step # 24 , 27, and 28
In the third step and the third control means in the present invention, the processing in steps # 31 and # 32 in the fourth control means in the present invention, and the power control circuit 54 in the full half-wave switching control means in the present invention, respectively. Corresponding.

According to the electric sauna bath 1 of the above-described embodiment, as shown in FIG. 8A, the first set temperature T1 can be set lower than the conventional set temperature for the overheat prevention control. Thus, the temperature rise of the planar heater 31 during normal use can be reduced. Therefore, since the maximum use temperature of the planar heater 31 and its surroundings is lowered, it is possible to use an inexpensive material having lower heat resistance than before. Thereby, the cost of the electric sauna bath 1 can be reduced.

Since the maximum temperature of the surface of the planar heater 31 is controlled, the overshoot of the temperature is reduced and a comfortable feeling in use is obtained.

Since the overheating prevention control is performed by switching between full-wave rectification and half-wave rectification, the present invention can be implemented without significantly changing the conventional electric sauna bath.

When the electric sauna bath 1 is applied to a foldable electric sauna bath, even if an abnormal usage such as energizing the folded state is performed, the above-mentioned excessive temperature rise will occur. Since the preventive control is performed, the thermal fuse does not blow and no failure occurs.

Since the thermistor 32, which is a semiconductor sensor, is used, it does not blow like a thermal fuse or has a limited life like a thermostat, and is maintenance-free.

In the above embodiment, the thermistor 32
Instead, various other temperature detection sensors can be used. Temperatures other than those described above may be set as the first set temperature T1 and the second set temperature T2. It is also possible to use the two planar heaters 31a and 31b only in parallel connection without connecting them in series. Further, one planar heater or three or more planar heaters may be used. Various types of heaters other than the planar heater may be used. Means other than switching between full-wave rectification and half-wave rectification may be used to reduce or increase the power to the planar heater 31.

In addition, the controller 3 or the electric sauna bath 1
Of the whole or each part, shape, size, number, material, content or order of overheat prevention control, timing, time setting,
Alternatively, the temperature setting and the like can be appropriately changed in addition to the above in accordance with the gist of the present invention.

[0070]

According to the first to fifth aspects of the present invention,
The temperature rise during normal use can be reduced,
It is possible to reduce the maximum operating temperature of the heater and its surroundings, and use an inexpensive material. Therefore, the cost of the electric sauna bath can be reduced.

According to the fourth and fifth aspects of the present invention, the excessive temperature rise prevention control of the present invention can be easily performed without significantly changing the conventional electric sauna bath.

According to the fifth aspect of the present invention, it is possible to easily perform the overheat prevention control for various set temperatures for using the electric sauna bath.

[Brief description of the drawings]

FIG. 1 is a sectional front view of a part of an electric sauna bath according to the present invention.

FIG. 2 is a side view of the electric sauna bath shown in FIG.

FIG. 3 is an enlarged sectional view showing an AA part of the electric sauna bath shown in FIG. 1;

FIG. 4 is a block diagram showing a circuit of a control device for the electric sauna bath.

FIG. 5 is a flowchart showing an overall procedure of an over-temperature prevention control.

FIG. 6 is a flowchart illustrating a procedure of a full-wave temperature excessive rise prevention control.

FIG. 7 is a flowchart illustrating a procedure of a control for preventing excessive temperature rise.

FIG. 8 is a diagram showing a comparison of a set temperature between the overheat prevention control according to the present invention and the conventional control.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 electric sauna bath 3 control device (overheat prevention control device) 31, 31a, 31b planar heater (heater) 32, 32a, 32b thermistor (temperature detection sensor) 53 microcomputer (first control means, second control means) , Third control means, fourth control means) 54 power control circuit (full-half-wave switching control means)

Claims (5)

[Claims] 1. An overheat prevention control for an electric sauna bath configured to heat a bathroom by supplying power to a heater and to control the power in accordance with a temperature detected by a temperature detection sensor. A method for reducing the power when the temperature detected by the temperature detection sensor is equal to or higher than a first set temperature; and after reducing the power in the first step, When the temperature detected by the temperature detection sensor becomes equal to or lower than a second set temperature before a set time has elapsed,
A second step of increasing the power, and a temperature detected by the temperature detection sensor does not fall below a second set temperature even after a set time has elapsed after the power is reduced in the first step. sometimes,
And a third step of stopping the supply of the electric power. 2. An overheat prevention control for an electric sauna bath configured to heat the bathroom by supplying power to a heater and to control the power in accordance with a temperature detected by a temperature detection sensor. An apparatus, wherein when the temperature detected by the temperature detection sensor is equal to or higher than a first set temperature, a first control unit that reduces the power, and the power is reduced by the first control unit. Thereafter, when the temperature detected by the temperature detection sensor before the set time has elapsed becomes equal to or lower than the second set temperature,
A second control unit that increases the power, and a temperature detected by the temperature detection sensor is equal to or less than a second set temperature even after a set time has elapsed after the power has been reduced by the first control unit. When it does not
And a third control means for stopping the supply of the electric power. 3. The heater according to claim 1, wherein the first set temperature is set higher than a maximum surface temperature of the heater, and the second set temperature is set lower than a maximum surface temperature of the heater. Item 3. The control device for preventing overheating of an electric sauna bath according to Item 2. 4. A full-wave switching control means for switching between half-wave rectification and full-wave rectification of an AC power supply for reducing or increasing electric power supplied to the heater. Item 4. An electric sauna bath heater control device according to item 3. 5. An overheat prevention control for an electric sauna bath configured to heat a bathroom by supplying power to a heater and to control the power in accordance with a temperature detected by a temperature detection sensor. An apparatus for reducing or increasing power supplied to the heater, a full-half-wave switching control means for switching between half-wave rectification and full-wave rectification of an AC power supply, A first control unit that switches the power to half-wave rectification when the temperature detected by the temperature detection sensor is equal to or higher than a first set temperature in a full-wave mode for supplying power; (1) After the power is switched to half-wave rectification by the control means, the temperature detected by the temperature detection sensor becomes equal to or lower than the second set temperature before a set time elapses. A second control unit for switching the power to full-wave rectification, and after the power is switched to half-wave rectification by the first control unit, the temperature is detected by the temperature detection sensor even after a set time has elapsed. A third control unit for stopping the supply of the electric power when the temperature of the heater does not fall below the second set temperature; and detecting the temperature by the temperature detection sensor in an adjustment mode for supplying the adjusted electric power to the heater. And a fourth control unit for stopping the supply of the electric power when the temperature to be performed becomes equal to or higher than the first set temperature.