JPH054569B2 - - Google Patents

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to a temperature control device for an electric kotatsu.

(b) Conventional technology Traditionally, the temperature of electric kotatsu was controlled by a thermostat connected in series to the heater.
In this case, regardless of whether the temperature set by the thermostat is set to "strong,""medium," or "low" when the heater is initially energized, the heater will remain at its maximum rating until the temperature inside the kotatsu reaches the set temperature. It generates heat using electric power and has an excellent start-up characteristic. This kind of characteristic is effective, for example, when the outside temperature is particularly low or when the user wants to warm up quickly, but on the other hand, temperature control is such that the thermostat is turned on after the temperature inside the kotatsu reaches the set temperature. This is done by turning the kotatsu off, but the interval between on and off is long, so the so-called differential becomes large, and the temperature inside the kotatsu is unstable, resulting in large temperature differences.
In addition, at the beginning of energization, even after the temperature inside the kotatsu reaches the set temperature, it becomes higher than the set temperature, causing a so-called overrun, and the temperature of various parts of the kotatsu, such as the protective guard, becomes high, creating a risk of burns. At the same time, it had the disadvantage that the high-temperature radiant heat caused pain in the feet.

For this reason, as shown in Japanese Utility Model Publication No. 51-21994, an electronic circuit consisting of a thermistor that detects the temperature inside the kotatsu, a volume that sets the temperature inside the kotatsu to a desired temperature, a triax connected in series with the heater, etc. is used. A kotatsu was used that accurately controlled the temperature inside the kotatsu so that it always remained at the desired temperature.

However, temperature control using this electronic circuit does not provide the rise characteristics seen in a thermostat. When set to ``High'', ``Medium'', or ``Low'',
The rise characteristics at each setting are different, and there is a drawback that it takes a long time from the initial energization to reach the set temperature especially when set to "low", so we aimed to improve the rise characteristics according to each set temperature.

However, in the above-mentioned Japanese Utility Model Publication No. 58-33499, the rise characteristic diagram based on the invention was divided into this publication and the second publication.
As shown in the figure, as is clear from this characteristic diagram, the rise is somewhat improved at each set temperature, but it tends to be faster when the set temperature inside the kotatsu is "high" and slower when it is "low". There is.

(c) Problems to be Solved by the Invention The present invention improves the various points mentioned above, and in particular, the same rise characteristics can be obtained no matter what temperature the temperature inside the kotatsu is set, and Reduces power consumption until the temperature reaches the set temperature to prevent overrun, and performs accurate temperature control when the set temperature is reached.

(d) Means for solving the problems The present invention provides a heating means, a temperature setting means, a temperature detection means, and a power control means having a first mode and a second mode and controlling the energization rate of the heating means. and when the temperature detected by the temperature detection means is below the detection level temperature of the level setting means, the heating means generates heat at the maximum power consumption in the first mode, and when the temperature is above the detection level temperature and below the set temperature range. At times, the heating means generates heat using power in the second mode that is lower than power in the first mode, and when the set temperature range is reached, the set temperature is maintained.

(E) Effect At the beginning of energization, the desired temperature is set by the temperature setting means, and after this setting, the temperature inside the kotatsu body detected by the temperature detection means is compared with the set temperature, and the detected temperature is detected to be lower than the set temperature. When the detected temperature is below the level temperature, the first mode of the power control means causes the heating means to generate heat at its maximum power consumption, and when the detected temperature is above the detection level temperature and below the set temperature, the second mode of the power control means causes the heating means to generate heat. Heat is generated with a power lower than the power in the first mode, and when the detected temperature reaches the set temperature, the set temperature is maintained by the phase control means.

(f) Examples Examples of the present invention will be described based on the drawings. Reference numeral 1 denotes a kotatsu main body in which a plurality of crosspieces 2...2 are combined vertically and horizontally to form a frame 3, and a plurality of support legs 4... are fixed to the corners of the frame. A storage section 5 is provided in the section, and a vacant space 6 is provided adjacent to the storage section.

Reference numeral 7 denotes a heater unit that is housed and fixed in the storage section 5, and includes a mounting frame 8 and a reflector 9 fixed to the frame.
The heating means 10 is composed of a plurality of lamp heaters (hereinafter referred to as heaters) whose both ends are fixed to the lower surface of the mounting frame 8, a mesh-like mixture retention guard 11, and a top plate 12. Reference numeral 13 denotes an electrical unit that adjusts the heating amount of the heaters 10, 10 housed in the space 6, and is connected to the heaters 10, 10 by a lead wire 14 inserted through the crosspiece 2.

Next, the schematic electrical circuit diagram shown in FIG. 2 will be explained. 15 is an AC power supply; 16 is a zero-cross pulse generating means that generates a pulse near approximately 0 degrees of the AC waveform; and 17 is a delay means that slightly delays the pulse of the pulse generating means and outputs it at approximately 0 degrees of the AC waveform. .

Reference numeral 18 denotes a temperature detection means (hereinafter referred to as a thermistor) consisting of a thermistor with a negative characteristic attached to a suitable position of the heater unit 7, and detects the temperature inside the kotatsu main body 1. Reference numeral 19 denotes a temperature setting means (hereinafter referred to as a volume) consisting of a volume that adjusts the heating amount of the heaters 10, 10 and sets the temperature of the kotatsu main body 1 to a desired temperature. 20 is a bridge circuit consisting of a circuit whose one side is the volume and a capacitor 21 connected in series with the volume, the thermistor 18 and a resistor 22 connected in series with the thermistor, and 23 is a comparison means consisting of a comparator (hereinafter referred to as a first comparator). ), the inverting input terminal is connected to the connection between the thermistor 18 and the resistor 22, and the non-inverting input terminal is connected to the connection between the volume 19 and the capacitor 21. This first comparator 23 has a potential (comparison potential) based on the temperature detected by the thermistor 18 and a charging potential (reference potential) of the capacitor 21 based on the temperature set by the volume controller 19.
When the temperature of the kotatsu main body 1 is lower than the set temperature, that is, when the comparison potential is lower than the reference potential, it is output.

Reference numeral 24 denotes potential dropping means (hereinafter referred to as a switching transistor) for discharging the charge in the capacitor 21 in response to a pulse signal from the delay means 17, and an emitter and a collector are connected to both ends of the capacitor 21.

25 is a comparator consisting of a comparator (hereinafter referred to as the second
a comparator) whose inverting input terminal is connected to the connection between the volume 19 and the capacitor 21,
A non-inverting input terminal is connected between resistor 26 and resistor 27.

28 is a first timer means for inputting the falling signal of the output signal of the second comparator 25 and outputting a pulse signal for a certain period of time (0.95 ms);
Similarly to the first timer means, a reference numeral 9 inputs the falling signal of the output signal of the second comparator 25 and outputs a pulse signal longer than the pulse signal of the first timer means 28 for a certain period of time (2.45 ms). This is second timer means. This first and second
The timer means 28 and 29 operate the switching transistor 24 in response to a pulse signal from the delay means 17.
When the signal turns ON, the output of the second comparator 25 becomes "H", and is output for a certain period of time when this signal falls.

30 connects the output of the first comparator 23 to the J terminal and connects the output of the first timer means 28.
The first flip-flop (first
1FF), 31 is the first comparator 25
The output of the second timer means 2 is connected to the J terminal.
9 is a second flip-flop whose output is connected to the CLK terminal (hereinafter referred to as 2nd FF); 32 is a first one-shot multivibrator (hereinafter referred to as 1st MV) which outputs at the falling edge of the pulse signal of the zero-cross pulse generating means 16; and 33 is a Said first timer means 2
A second one-shot multivibrator (hereinafter referred to as 2nd MV) that outputs when the output signal of No. 8 falls, 34
is a third multivibrator (a third multivibrator) which outputs a pulse signal based on the output of the first comparator 23;
3MV), 35 is the Q terminal of the first FF 30 and the
The first AND gate connects the Q terminal of 2FF31 to the input side, and 36 connects the terminal of the first FF30 and the first AND gate.
A second AND gate 37 connects the Q terminal of 2FF31 to the input side, and 37 connects the terminal of the first FF30 and the second AND gate.
The third AND gate 38 has the terminal of 2FF31 connected to the input side, and the third AND gate 38 has the output of the first AND gate 35 and the output of the first MV32 connected to the input side.
4AND gate; 39 is a fifth AND gate whose input side is connected to the output of the second AND gate 36 and the output of the second MV 33; 40 is the third AND gate 3;
7 and the output of the third MV 34 are connected to the input side, and 41 is the fourth, fifth, and
This is an OR gate that outputs when at least one of the outputs of the sixth AND gates 38, 39, and 40 is "H".

42 is a switching element (TAIAC) connected in series to the heaters 10, 10; 43 is a drive whose base is connected to the output of the OR gate 41, whose collector is connected to the gate of the TAIAC 42 via a resistor 44, and whose emitter is grounded. It is a transistor.

the resistors 26, 27, the second comparator 25, the first and second timer means 28, 29, and the first and second timer means 28, 29;
2FF30, 31 constitute a level setting means for setting a detection level temperature lower than the set temperature when a desired temperature is set by the volume 19.

The fourth and fifth AND gates 38 and 39 and the first and second MVs 32 and 33 constitute power control means.
This power control means is a fourth AND gate 38 that causes the heaters 10, 10 to generate heat at their maximum power consumption.
and the first MV32 (4th, 5th,
6) and a second mode (see FIGS. 4, 5, and 6) consisting of a fifth AND gate 39 and a second MV 33 that generate heat with lower power than the first mode.

A third MV that uses the outputs of the sixth AND gate 40 and the first comparator 23 as direct inputs.
34 constitutes a phase control means.

Next, the characteristic diagrams shown in FIGS. 3a to 3d will be explained. a is the rated power consumption of heaters 10, 10
This shows the temperature A and the thermistor temperature B in the kotatsu body 1 when the resistance value of each component in the bridge circuit 20 and the value of the capacitor 21 are experimentally determined at 500W. Sometimes, it is desirable that the thermistor temperature B and the temperature inside the kotatsu body 1 show the same linearity, but as shown in the figure, in reality, the thermistor 18 also detects the temperature on the heater unit 7 side, so the temperature inside the kotatsu body 1 is It is slightly higher than A. Therefore, when the heaters 10, 10 generate heat with their rated power consumption of 500 W at the beginning of power supply, the temperature difference between the temperature A in the kotatsu body 1 and the thermistor temperature B becomes even larger.

b is a curve drawn based on a formula based on the time of the pulse signal from the zero-crossing pulse generating means 16, and the power consumption increases as the time of the pulse signal is short and decreases as the time of the pulse signal is long.

This is a curve determined by the charging ratio (Vc) of the c capacitor 21 and the time of the pulse signal from the zero-cross pulse generating means 16, and changes depending on the position of the volume control 19 ("high", "middle", "low"). . That is, the charging time for the capacitor 21 is long if it is in the "low" position, and short if it is in the "high" position.

d shows the relationship between the rate of change (VTh) of the thermistor 18 and temperature; when the aforementioned volume 19 is set to "low", the rate of change (VTh) is 0.44, and the temperature inside the kotatsu body 1 at this time is 0.44. Temperature A is approximately 34°C, which is generally considered the "low" temperature setting level, and it is set to "high".
When the rate of change (VTh) is 0.76, the temperature inside the kotatsu body 1 at this time is about 67°C, which is generally considered a "high" temperature level.

In this way, there is a correlation between a to d in Figure 3, and b, c, and d are drawn based on the characteristic diagram of a,
In particular, in the curve c, when the volume 19 is set to "high", the temperature inside the kotatsu body shown in a is determined to be at the "high" stable level (approximately 67 degrees Celsius), and when the volume 19 is set to "low", the point is determined. The temperature inside the kotatsu body shown in a is "low"
The point at which the temperature reaches a stable level (approximately 34℃) is determined.

Next, we will discuss the operation. If it is desired to set the inside of the kotatsu body 1 to a "high" temperature, the AC power supply 15 is supplied and the volume 19 is set to the "high" position to minimize the resistance value. The charging time of the capacitor 21 is determined in accordance with the temperature setting by the volume control 19 described above, and the charging draws the curve VR1=min shown in c in FIG. I) in Figure 4 is set. That is, the setting of this detection level I changes the level at the time of the inverted input of the second comparator 25, and as a result, the first and second timer means 28, 2
9's operation timing is off. The detection level temperature at this time indicates the point at which the set temperature reaches the stable area,
Specifically, the protective guard 11 is at a high temperature that does not cause discomfort when touched (for example, about 54° C.), and is at a temperature that does not cause overrun.

As the desired temperature is set by the aforementioned volume control 18, the comparison potential of the first comparator 23 is lower than the reference potential due to the relationship (VC)>(VC)>(VTh), so this comparator outputs Input to the J terminals of the first and second FFs 30 and 31. On the other hand, the zero-cross pulse based on the AC power supply waveform is input to the first MV 32 and becomes a slightly delayed pulse by the delay means 17, turning on the switching transistor 24 and discharging the capacitor 21. At this time, the output of the second comparator 25 becomes "H", and this output is transmitted to the first comparator 2 as the capacitor 21 starts charging again.
When the levels of the reference potential of 3 and the reference potential of the second comparator 25 are reversed, the output becomes "L", and the first and second timer means 28, 29 start timekeeping operation, and first the first timer means 28 The output of the first FF 30 is inverted from "H" to "L" and at the time of its fall, the Q terminal of the first FF 30 is set to "H". On the other hand, the output of the second timer means 29 is inverted from "H" to "L", and the Q terminal of the second FF 31 is set to "H".
Then, the first AND gate 35 is operated, and the fourth AND gate 38 is operated by its output and the output of the first MV 32, and the drive transistor 43 is turned on by the output via the OR gate 41, and the TRIAC 42 is turned on, and the heaters 10, 10 are turned on. generates heat at the rated power. At this time, TRIAC42 turns on near 0° of the AC power waveform, so
The heaters 10, 10 have their rated power consumption (approximately
500W) (Figure 6, mode 1).

Eventually, the temperature inside the kotatsu body 1 rises, and the thermistor 18 that detects this temperature rise gradually lowers its resistance value, and the comparison potential of the first comparator 23 rises (VC)>(VTh)>(VC). Then, when the output of the first timer means 28 falls, the Q terminal of the first FF 30 is inverted and the output becomes "H", and the output of the second AND gate 36 becomes "H". Then, when the output of the second timer means 29 that has set the detection level temperature falls and when the comparison potential and reference potential of the first comparator 23 are reversed, the output becomes "H" and in the next half cycle of the AC power supply. The output of the second MV 33 is set to "H" by the first timer means 28, which operates the fifth AND gate 39 and the OR gate 41, thereby reducing the power consumption of the heaters 10, 10 to approximately 400 W, which is lower than the rated power consumption. (Figure 6, Mode 2) Then, the temperature inside the kotatsu body 1 further increases and eventually reaches a region close to the set temperature (see Figures 4 and 6), when (VC) < (VC) < ( VTh)
Therefore, the position at which the levels of the reference potential of the first comparator 23 and the comparison potential are inverted changes greatly and becomes close to the discharge timing of the capacitor 21. At this time, even if the output of the first comparator 23 is "H" due to the above-mentioned potential reversal, the first
and the outputs of the second FFs 30 and 31 are inverted, the first and second AND gates 35 and 36 do not operate, and the outputs of the second FFs 30 and 31 are inverted.
3AND gate 37 outputs and the 6th AND gate 4
Outputs 0 and turns on the drive transistor 43.
The phase of the heaters 10, 10 is controlled by conducting the TRIAC 42. That is, since the output of the third MV 34 depends only on the change in the output of the first comparator 23, the heater 10, 10 about 260W ~
Control within the range of 165W.

Also, the broken line in Figure 6 shows the case where the temperature inside the kotatsu body 1 is set to "low", and the second mode is approximately
Generates heat at 260W, and in the set temperature range heater 10,
10 is controlled in the range of approximately 110W to 50W.

In Figure 8, the temperature set by volume 19 is "high"
This shows the time chart in the second mode in the case of , the case of "medium" and the case of "low".
This indicates that the power is reduced according to each set temperature. To explain this based on FIG. = 0.2, and when the output of the first timer means 28 is inverted based on this point X ₀ , Y ₀ , Z ₀ , that is,
After 0.95ms, it becomes (X) for "high" setting, (Y) for "medium" setting,
In the case of "low" setting, it becomes (Z). Furthermore, when the output of the second timer means 29 is inverted, that is, after 2.45 ms, in the case of the "high" setting, (X
), and if the setting is “medium”, it will be (Y),
In the case of "low" setting, it becomes (Z). As is clear from the diagram in Figure 3c, in the case of the "high" setting, the detection level temperature (X) is set at a point much earlier than the set temperature of the curve to prevent overrun.
In the case of "Low" setting, the detection level temperature (Z) is set at a point relatively close to the set temperature on the curve, and the power consumption of the heater is reduced as close to the set temperature as possible, and the set temperature is set to the maximum without overrun. is approaching.

In addition, the power consumption in the second mode when set to "Medium" is approximately 320W, and after the second mode it is 133W to 100W.
The phase is controlled by

(g) Effects of the Invention As described above, the present invention allows the heating means to generate heat at the maximum power consumption in the first mode when the temperature detected by the temperature detection means is lower than the detection level temperature of the level setting means, so that the detection level is lowered. When the temperature is higher than the set temperature range and lower than the set temperature range, the heating means generates heat using the power in the second mode, which is lower than the power in the first mode, and when the set temperature range is reached, the set temperature is maintained. No matter what temperature is set, the same rising characteristics can be obtained, and the set temperature can be reached within the kotatsu body in a short time. Moreover, since the power consumption is reduced before the set temperature range is reached at the time of initial power supply, overrun can be prevented, and abnormal high temperatures and painful radiant heat in various parts of the kotatsu body can be prevented. Furthermore, once the temperature inside the kotatsu body reaches a stable region, phase control can be performed at a cycle that does not affect noise, and in the case of a lamp heater, flickering can be eliminated and temperature control can be performed accurately. Further, when the desired temperature is set by the temperature setting means, in order to reduce the power of the second mode of the power control means according to this set temperature,
You can make the most of the characteristics of each setting state.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of an electric kotatsu equipped with the temperature control device of the present invention, Figure 2 is an equivalent circuit diagram, and Figure 3 is a temperature characteristic diagram, where part a shows the relationship between the temperature inside the kotatsu body and the thermistor temperature. In the figure, part b is a diagram of the relationship between zero cross time and power consumption, part c is a diagram of the relationship between the setting value by the volume and the charging ratio of the capacitor, and part d is a diagram of the relationship between temperature and the rate of change of the thermistor. Figure 4 shows the relationship between zero cross time and electric power and capacitor charging ratio when the temperature inside the kotatsu body is set to "high" by the volume control, and Figure 5 shows the relationship between the temperature inside the kotatsu body and the temperature when it is set to "low". Figure 6 is a relationship diagram similar to Figure 4, Figure 6 is a correspondence diagram between temperature inside the kotatsu body and electric power, Figure 7 is a time chart of each part shown in Figure 2, and each point ~
Figure 8 is a time chart showing the waveform of the corresponding part of
It shows a time chart in the second mode in the case of "medium" and "low". 1... Kotatsu body, 10, 10... Heating means (heater), 16... Zero cross pulse generating means,
18...Temperature detection means (thermistor), 19...
Temperature setting means (volume), 20...Bridge circuit, 21...Capacitor, 23...Comparison means, 2
5... Comparator, 25, 28, 29, 30, 31...
...a second comparator constituting the level setting means;
first and second timer means, first and second FF, 3
2, 33, 38, 39...first and second multivibrators, fourth and third multivibrators constituting the power control means
5AND gate, 34, 40...3rd multivibrator and 6th AND gate constituting phase control means.

Claims (1)

[Scope of Claims] 1. A heating means for heating the kotatsu body, a temperature setting means for setting the kotatsu body to a desired temperature, and a temperature detection means for detecting the temperature of the kotatsu body.
Level setting means for setting a detection level temperature lower than the set temperature when a desired temperature is set by the temperature setting means; a first mode for causing the heating means to generate heat at its maximum power consumption; and power for the first mode. and a power control means for controlling the energization rate of the heating means having a second mode of generating heat with a lower power than the above, and heating when the temperature detected by the temperature detection means is equal to or lower than the detection level temperature of the level setting means. The heating means generates heat using electric power in a first mode, and when the temperature is higher than the detection level temperature and lower than the set temperature, the heating means generates heat using electric power in the second mode, and when the set temperature range is reached, the set temperature is maintained. Kotatsu temperature control device. 2. When the desired temperature is set by the temperature setting means, the second temperature of the power control means is adjusted according to this set temperature.
The temperature control device for an electric kotatsu according to claim 1, characterized in that the power of the mode is set.