JPH01196611A - Temperature control device - Google Patents

Abstract

PURPOSE:To suppress the rise of a temperature under a cushion and to prevent the degradation of the impedance of temperature thermal resin by executing temperature detection at a non-energizing time to the heater line of floor- warming, etc., in a constant period, determining the energizing time to the heater line according to the difference of the temperature and detecting the local heat insulating condition of the heater line during heater energizing. CONSTITUTION:Since a control means 76 drives and re-starts a driving means 40 in the constant period, the exact temperature detection can be executed during the stop of the driving means 40. Since the driving means 40 is driven by the signal of a first comparing means 74, the energizing time to a heater line 9 in the constant period goes to the remaining time of a time to drive the driving means 40 by the signal of a first comparing means 74 from the stop of the driving means 40. When local heat insulation is generated during the heater energizing, since the energizing to the heater line is forcibly stopped by the signal of a second comparing means 102, an energizing rate can be decreased. Thus, the temperature rise under the cushion can be suppressed and the degradation of the impedance of the temperature thermal resin can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a temperature control device for electric heating appliances such as electric carpets and floor heaters.

2. Description of the Related Art An example of a conventional electric heating appliance such as an electric carpet is shown in FIG. 1 is an electric carpet main body, which is a so-called two-wire type electric carpet in which a thermosensitive resin 6 that detects the surface temperature and a heater wire 9 that contributes to heat collection are wired separately in the main body 1. be. 2 is a controller box that controls the surface temperature of the electric carpet 1.

FIG. 6 is a perspective view of a portion of the thermosensitive resin 6. FIG.

A thermosensitive resin 6, which is filled between the pair of first electrode wires 3.4 and whose diimpedance changes depending on the temperature, is integrally formed. In addition, 6 is a core thread, and 7 is an outer skin. The electrode wire 3 is spirally wound around the core thread 6, and the temperature-sensitive resin 6 is filled around the electrode wire 3, and the outside of the electrode wire 3 is similarly wound spirally. The electrode wire 4 that came off is covered with an outer sheath 7.

FIG. 6 is a diagram showing changes in impedance temperature characteristics of the thermosensitive resin 5, which has a characteristic that the impedance decreases as the temperature rises. FIG. 7 is a partial perspective view of the heater wire 9 that contributes to heating the electric carpet 1. The second electrode wire 8, the heater wire 9, and the insulating resin 1o are integrally constructed. 11 is a core thread, 12 is an outer sheath, a second electrode wire 8 is spirally wound around the core thread 11, and an insulating resin 1o is filled around the second electrode wire 8; The heater wire 9 wound around the heater wire 9 is covered with an outer sheath 12. FIG. 8 is a conventional temperature control circuit diagram. 13
is an AC power supply, and 14 is a power switch. 15,
18, 17.18 is a resistor, 19.20 is a diode, 2
1.22 is a capacitor. Resistor 15, the first of the pair
The impedance of the electrode wire 3°4 and the temperature thermosensitive resin 5 (
Z,! : Called. ), a resistor 16, a diode 19,
A smoothed temperature signal voltage of the positive cycle of the AC power supply 13 is obtained by the capacitor 21 . The relational expression of the detected temperature signal voltage is approximately as shown in equation (1), assuming that the voltage of the AC power supply 13 is vAc.

1/(1+resistance 15/z)×vAc...group(1)
That is, as the temperature rises, the impedance of the thermosensitive resin 5 decreases, so the smoothed temperature signal voltage decreases. In addition, the diode 20. Resistor 17, capacitor 2
2, even in the negative cycle of the AC power source 13, a voltage symmetrical to that in the positive cycle is applied to the temperature thermosensitive resin 5. This is because the thermosensitive resin 5 is a nylon-based chemical resin, and is intended to prevent polarization deterioration and stabilize impedance. 23 is a diode, 24,
25° 26, 27, 28 are resistors, 29 is a variable resistor which is a temperature setting means for setting the desired temperature, 3
Q is smoothed by a capacitor and becomes the temperature setting voltage. 31 is a control means, temperature thermosensitive resin 5
The temperature signal voltage of the temperature setting means 29 and the temperature setting voltage of the temperature setting means 29 are compared and controlled. 32 is a diode, 33
．． 34 is a resistor, 35 and 36 are capacitors, 37 is a constant voltage diode, 38 is a relay which is a power control means, and 39 is a diode for surge absorption of the relay 38. Diode 32, resistance 33.34, capacitor 35
．． 36, the driving power for the control means 31 and the relay 38 is obtained from the constant voltage diode 37.

40 is a transistor for driving means of the relay 38;
41 and 42 are resistors, and 43 is a diode. A transistor 40 is turned on and off by a signal from the control means 31, controls a relay 38, and controls whether or not the heater 9 is energized. Note that the resistor 42 and diode 43 are connected to the relay 38.
This is to prevent chattering. 44.45 is a diode, 46.47 is a low resistance heating resistor, 48
is a safety circuit. Control means 31 is out of order and relay G8
When the heater wire 9 of the electric carpet 1 body remains on, the temperature of the heater wire 9 of the electric carpet 1 body rises abnormally, the insulating resin 10 melts, and the second electrode wire 8 and the heater wire 9 come into contact, causing the heating resistor 46.47 to rise. A large current flows and the Joule heat generates safety circuit 4.
8 is operated to cut off the AC power supply 13. Note that normally, the impedance of the insulating resin 1o is very large, so that only a small current flows through the heating resistors 46 and 4, so that the safety circuit 48 does not operate.

Next, as another example of the conventional technology, as shown in FIGS. 9 to 11, there is a so-called single-wire type electric blanket in which the heater wire and electrode wire are integrated, which is used in electric blankets with relatively low power consumption. An example of a blanket will be explained. Note that the same reference numerals are given to the same components as those of the conventional example shown in FIGS. 4 to 8.

FIG. 9 is an overall external view of the electric blanket. Reference numeral 49 indicates an electric blanket main body, 6o indicates a controller box, and a single line in which a temperature-sensitive resin 5 and a heater wire 9 are integrated is wired inside the electric blanket 49. FIG. 10 is a perspective view of a part of the heater-type temperature-sensitive resin.
A thermosensitive resin 6 whose impedance changes depending on the temperature is filled between the electrode wire 51 and the electrode wire 51, and its temperature characteristics are as follows.
It is similar to the figure. In addition, 62 is a core thread, and 53 is an outer skin. FIG. 11 is a control circuit diagram of a one-line blanket. 1
3 is an AC power supply, and 14 is a power switch. 5 is a thermosensitive resin whose impedance changes depending on the temperature, 9 is a heater wire, and 51 is an electrode wire. 64 is a diode, 55.56 is a resistor, 57.58 is a capacitor, 5
Reference numeral 9 denotes a constant voltage diode, which constitutes a constant voltage circuit. 60 is a base-grounded transistor for temperature detection, 61, 62, and 63 are diodes for transistor protection, and 64 is a heating resistor connected to the electrode wire 51. The temperature detection method is such that a transistor 60 whose base is grounded is turned on in a negative half cycle of AC power supply △ 13, and from the Beine emitter to the transistor 1, the heating resistor 64, the electrode wire 51, the temperature thermosensitive resin 5, the heater wire 9 and the like are connected. The flowing temperature signal current is converted into a temperature signal voltage by a resistor 66 and a capacitor 57 connected to the collector side. Reference numeral e6 is a thyristor, which is a power control means, and controls the on/off of energization of the heater wire 9. Reference numeral 66 is a resistor, and reference numeral 67 is a capacitor, which prevents malfunctions due to noise. In addition, for temperature detection, the thyristor is non-conductive during the negative half cycle, and a uniform electric field is applied between the temperature thermosensitive resin 6 and the electrode wire 51 at any part, allowing accurate temperature detection of the entire heater wire 9. It is something that can be done. 68 is a diode, 69, 70
, 1 is a resistor, 72 is a variable resistor which is a setting means for setting a desired temperature, and 73 is a capacitor. These configurations create a smoothed temperature setting voltage.

74 is a comparator which is a comparison means for comparing the temperature signal voltage and the temperature setting voltage; 75 is a zero volt pulse generation means which generates a pulse synchronized with the AC power supply 13; and 76 is a control means. Based on this, the thyristor 66 is triggered in synchronization with the pulse of the zero volt pulse generating means 76 to control the temperature to a desired level. 77 is a diode, 78 is a resistor, 79
80 is a capacitor, and 80 is a constant voltage diode. These components create a power source for the control means 76 and the comparator 74.

48 is a safety circuit, 81 is a diode, 82 is a heating resistor, 83 is a thyristor, 84 is a resistor, 86 is a capacitor, and these are the thyristor 6 which is a power control means.
6 or when the temperature rises abnormally, the control means 76 triggers the Cyrisk-83 to flow a large current through the heating resistor 82, and the Joule heat operates the safety circuit 48 to cut off the AC power supply 13. It is something. Also, when the temperature thermosensitive resin 6 melts due to abnormal temperature, a large current flows through the diodes 61 and 62, the heating resistor 64, the electrode wire 51, the temperature thermosensitive resin 5, and the heater wire 9, and similarly the heating resistor 640
The safety circuit 48 operates due to the Joule heat and cuts off the AC power supply 13.

Problems to be Solved by the Invention However, the above configuration has the following problems.

(1) For example, in an electric carpet with a power consumption of 300 watts or more, if a heat insulator is placed on the heater wire 9 without locally covering the temperature thermosensitive resin 5, the temperature thermosensitive resin 5 will prevent the abnormal temperature rise of the heater wire 9. Not detectable at all. This is because the thermosensitive resin 6 and the heater wire 9 are wired separately, and the underside of the insulation material changes color due to the abnormal temperature rise of the heater wire 9, which eventually reaches the melting temperature of the insulating resin 1o. Something happened. Furthermore, since the temperature-sensitive resin 5 and the heater wire 9 are wired in pairs, there is a limit in terms of productivity and cost reduction.

@) When using a heater-type temperature-sensitive resin in which the temperature-thermosensitive resin 5 and the heater wire 9 are integrated, the disadvantage of (1) can be solved, but it is limited to electric blankets with relatively low power consumption. Ru. Furthermore, when several hundred watts of power are controlled by Cyrisk, there is a problem in that the number of heat dissipation fins increases and noise increases.

(3) In the second conventional example, the non-conducting region of the thyristor (the negative half current /L/ of the AC power supply 13) is used for temperature detection, and therefore the temperature of the heater wire 9 can be accurately detected. However, in the case of a bidirectional power control means such as a relay, the heater wire 9 is energized even in the negative half cycle, so the temperature of the thermosensitive resin 5 between the heater wire 9 and the tFM wire 51 is evenly distributed. Since no electric field is applied to the heater wire 9, accurate temperature detection of the heater wire 9 cannot be performed. Therefore, although the relay is periodically de-energized by the control means to accurately detect the temperature of the thermosensitive resin 5, the temperature exceeds the heat resistance limit of the thermosensitive resin 6 when keeping a local area such as a cushion, etc. The impedance characteristics changed, and the area under the cushion became hot, posing the risk of scorching or discoloration.

Means for Solving the Problems In order to solve the above problems, the temperature control device of the present invention has an integrated structure in which the diimpedance changes depending on the temperature by filling between the electrode wire, the heater wire, and the electrode wire and the heater wire. a temperature detection circuit that detects a temperature signal of the thermosensitive resin, a power control means that turns on and off the energization of the heater wire, a drive means that drives the power control means, and a temperature detection circuit that sets the temperature to a desired temperature while the drive means is stopped. The first comparison means compares the signal of the first setting means and the temperature detection circuit, and while the drive means is being driven, the second comparison means compares the signal of the temperature detection circuit with the second setting means for detecting local heat retention. a timer means for forcibly driving and restarting the driving means at a certain regular cycle; and a timer means for driving the driving means with a signal from the first comparing means when the driving means is stopped;
The control means is configured to stop driving the driving means in response to a signal from the second comparing means when the driving means is being driven, and to keep the driving means stopped during the fixed cycle time.

According to the present invention, with the above-described configuration, the control means drives and restarts the driving means at a certain regular cycle, so that accurate temperature detection can be performed while the driving means is stopped, and the signal from the first comparison means can be used to detect the temperature. Since the driving means is configured to be driven, the time during which the heater wire is energized within a certain period is the remaining time from when the driving means is stopped to when the driving means is driven by the signal from the first comparing means, and when the heater is energized. When local heat retention occurs, the signal from the second comparing means forcibly stops energizing the heater wire, which has the effect of lowering the energization rate.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

FIG. 1 is a temperature control circuit diagram showing one embodiment of the present invention. Components that are the same as those of the conventional example are given the same numbers. A thermosensitive resin 6, a heater wire 9, and an electrode wire 61 are integrally constructed and wired inside the electric carpet body 1. 1
3 is an AC power supply, and 14 is a power switch. 32 is a diode, 33 is a resistor, 38 is a relay which is a power control means, 39 is a diode for absorbing surge of the relay 38, and 4o is a transistor which is a driving means for driving the relay 38. 46 and 47 are heat generating resistors, and 48 is a safety circuit. 54 is a diode, 55°66 is a resistor,
57 and 58 are capacitors, and 69 is a constant voltage diode, which constitute a constant voltage circuit. eO is a base-grounded transistor for temperature detection, 61,6
2,63,97°^ 98 is a diode, 99 is a resistor. The temperature detection method uses a transistor p whose base is grounded as in other conventional examples.
Ae o is turned on in the negative half cycle of the AC power supply 13,
The temperature signal current flowing through the transistor J60, heating resistor 47, electrode wire 61, thermosensitive resin 6, and heater wire 9 is converted into a temperature signal voltage by a resistor and a capacitor 57 connected to the collector side.

68 is a diode, 69. To, 71 is a resistor, 72 is a variable resistor which is the first setting means for setting the desired temperature, and 73 is a capacitor, and they create a smoothed temperature setting voltage. . 74 is a comparator which is a first comparing means for comparing the temperature signal voltage and the temperature setting voltage; 75 is a zero volt pulse generating means which generates a pulse synchronized with the AC power supply; and 76 is a microcomputer (hereinafter referred to as microcomputer) which is a control means. ), and when the transistor Al40, which is the driving means, is turned off, the comparator V-
In response to the output signal of 174, the transistor 40 is turned on and the relay 38 is controlled, thereby controlling whether or not the heater wire 9 is energized. 77.89 is a diode, 78
79 is a resistor, 79 is a capacitor 80 is a constant voltage diode, and these structures create a power source for the comparator 74. Further, 90 is a diode, 91 is a resistor, 92 is a capacitor, and 93 is a constant voltage diode.These configurations create a driving power source for the microcomputer. 94 is a reset circuit for the microcomputer 76, and 96 is a clock circuit for the microcomputer T6. Reference numeral 96 is a timer counter which is a timer means, and creates a certain periodic period of time by counting the pulses of the zero volt pulse generator 117B. Furthermore, if the microcomputer e malfunctions and the relay 38 remains on, the temperature of the sweater wire 9 inside the electric carpet 1 body rises abnormally and the temperature-sensitive resin melts, the electric Wi
When the wire 61 and the heater wire e come into contact with each other, a large current flows through the heat generating resistors 46 and 47 due to the contact portion, and the safety circuit 48 operates to cut off the AC power source 13. However, normally, the impedance of the temperature-sensitive resin 5 is very large, so only a small current flows through the heating resistors 46 and 47, so the safety circuit 48 does not operate. Further, 9e is a resistance. 1oO1101 is a resistor, which constitutes a second setting means. Reference numeral 102 denotes a comparator as second comparison means, and the output signal thereof is detected by the control means only while the drive means 4o is on.

Based on the above configuration, the temperature control method of this embodiment will be explained using FIGS. 2 and 3.

After turning off the transistor A40 of the driving means, the microcomputer T6 counts the number of pulses of the zero/1/l-pulse generating means 75 using a timer counter 96, thereby creating a certain fixed period. (For example, 6 minutes.) Then, while the transistor 4o is off, the △ relay 38 is off and the contact of the relay 38 is open, so that there is a gap between the temperature thermosensitive resin 6 and the electrode wire 51. There is a uniform electric field applied to any part of the heater wire 9.
The overall temperature can be accurately detected by using the transistor 6o whose base is grounded during the negative half cycle of the AC power supply 13. In normal temperature control, a comparator 74 compares the temperature signal voltage of the heater wire 9 with the temperature setting voltage of the variable resistor 72, which is the first setting means, and generates a drive signal to request the relay 38 to turn on. Microcomputer 7e
is input. The microcomputer 76 immediately
, 40, the relay 38 is turned on and the heater wire 9 is energized. Here, as shown in FIG. 2, the time during which the heater wire 9 is energized (TOn) is the difference time until the ON request signal is received from the comparator 74 ("off") within a certain fixed period (Ttotal). Become.

Temperature control is achieved by changing the setting means 72. The time of ff changes, and the ot of T'on within a certain fixed period (T)
a1 The desired temperature can be obtained by changing the time and therefore changing the energization rate of the heater wire 9. In addition,
The timer counter 96 is stored in the microcomputer 76, and when the microcomputer 76 turns off the transistor 40, it is reset and restarts the timer counting.

FIG. 3 shows a pattern of energization rate when the electric carpet 1 is kept locally warm with a cushion or the like. this is,
The temperature thermosensitive resin 6 is filled between the heater wire 9 and the electrode #161, and from an electric circuit perspective, it becomes a parallel circuit, so if the local heat is kept warm, if the heater wire 9 is still hot, the relay 38 from the comparator 74 This indicates that the on-request signal for T is less likely to be generated, and therefore the time T increases and the overall energization rate decreases. Since the energization rate is reduced in this way, it is possible to suppress the rise in temperature of the heater wire 9 under the cushion when the cushion is kept locally warm.

Note that by configuring the control means 76 with a microcomputer and configuring the timer counter 96 within the microcomputer 6, the circuit configuration can be greatly simplified.

Further, by using a bidirectional control element as the power control means, there is an effect that the heater tiA9 can be used effectively.

Note that in one embodiment of the present invention, the timer counter 96
Although the pulses of the zero-bottom pulse generating means 75 are counted, the clock circuit 95 may also be counted, and the present invention is not limited to this embodiment.

Further, in this embodiment, the relay 38 is used as the power control means, but a triac may also be used, and the present invention is not limited to this.

Then, when the transistors J, 40 of the driving means are turned on to keep the local area warm, and when a signal from the second comparing means 102 is generated, the microcomputer 76 immediately turns off the relay 38, and within the fixed cycle time, the relay 38 is turned off. It is possible to maintain the OFF state and further reduce the energization rate to suppress the rise in temperature under the cushion (T'.ff section in Fig. 3).

In this embodiment, the timer counter % counts the pulses of the zero-volt pulse generating means 76, but the invention is not limited to this.

Further, in the embodiment, the relay 38 is used as the power control means, but a triac may also be used, and the present invention is not limited to this.

Furthermore, in this embodiment, the first. Although a comparator is used as the second comparison means, the microcomputer 76 may include an analog-to-digital converter and the comparison may be made within the microcomputer 76. Similarly, the present invention is not limited to this.

Effects of the Invention As described above, the temperature control device of the present invention provides the following effects.

■ Accurately detects the temperature when the heater wire is not energized within a certain period, determines the energization time to the heater wire based on the difference between them, and also determines the local heat retention state of the heater wire when the heater wire is energized. Since this is a control method that detects local heat retention, it has a high ability to detect local heat retention, suppresses temperature rises under the cushion, prevents deterioration of the impedance of the temperature-sensitive resin in that area, and enables stable temperature control of electric carpets over a long period of time. be able to.

■ Extremely safe as the thermosensitive resin monitors the heater wire temperature.

■ Since the temperature-sensitive resin and heater wire are integrated, the wiring process inside the electric carpet is simplified and productivity is improved.

FIG. 1 is a temperature control circuit diagram of an embodiment of the present invention, FIGS. 2 and 3 are diagrams showing a hallway control method, and FIG. 4 is a diagram of the main body configuration of a conventional electric carpet. Figure 6 is a perspective view of a partial configuration of the same temperature thermosensitive resin, Figure 6 is a diagram of impedance change temperature characteristics of the thermosensitive resin, Figure 7 is a perspective view of a partial configuration of the heater wire, and Figure 8 is shown in Figure 4. 9 is a front view of another conventional electric blanket, FIG. 10 is a perspective view of a partial configuration of a heater-type thermosensitive resin, and FIG. 11 is a diagram of the electric blanket shown in FIG. 9. It is a temperature control circuit diagram.

Name of agent: Patent attorney Toshio Nakao and 1 other person No. 4
Fig. 5 / S Kaku 6 Fig. 20 47) ω /θQ;φ(
A book surface ks & Figure 7 Figure 9] Figure 0

Claims (1)

[Claims] A heater wire that contributes to heat collection, an electrode wire that detects a temperature signal, a heater-type thermosensitive resin that is filled between the heater wire and the electrode wire and whose impedance changes depending on the temperature, and that is integrated with the heater wire. a power control means for turning on and off electricity; a driving means for driving the power control means; a temperature detection circuit for detecting a temperature signal current flowing through the thermosensitive resin via the electrode wire; and a temperature detection circuit for setting the temperature to a desired temperature. a first comparing means for comparing a signal of the temperature detection circuit when the drive means is stopped and the first setting means; a signal of the temperature detection circuit when the drive means is being driven; and a first comparison means for comparing the signal of the temperature detection circuit when the drive means is stopped; a second setting means for detecting local heat retention of the wire; a second comparison means for comparing the second signal with the second setting means; and a second comparison means for forcibly stopping the driving means at a certain regular period. a timer means for restarting; when the driving means is stopped, the driving means is driven by a signal from the first comparing means; and when the driving means is being driven and the local heat is kept warm, the driving means is driven by a signal from the second comparing means; A temperature control device comprising a control means for forcibly stopping the driving means and keeping the driving means stopped during the periodic period.