JP2005353433A - Planar heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar heater capable of being structured by using a high-wattage heater wire, reduced in internal heat generation and reduced in electromagnetic waves generated from a heater wire. <P>SOLUTION: This planar heater is provided with a heater wire unit 14 with a first heat generation wire 11, a second heat generation wire 12 and a temperature-sensitive layer 13 formed therein, a first rectification element 16, a power control element 17, a second rectification element 18, a third rectification element 19, a temperature detection part 20 and a control part 24. By connecting the first heat generation wire 11 and the second heat generation wire 12 in parallel with an A.C. power source 15 and by detecting temperature of the temperature-sensitive layer 13 on the side of a cycle opposite to the side of a current-carrying cycle of the first heat generation wire 11 and the second heat generation wire 12, a resistance value of unit length of the first heat generation wire 11 and the second heat generation wire 12 is increased, whereby high wattage, reduction of electromagnetic waves and reduction of heat generation from the rectification elements can be realized by a thin wire material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a planar warming tool that reduces electromagnetic waves generated from a heater wire in an electric blanket or the like.

  Conventionally, this type of sheet heating device has two heating wires constituting the heater wire connected in series, the flowing current is reversed, the electromagnetic waves generated from the heating wires are canceled out, and the amount of electromagnetic radiation emitted from the heater wire (See, for example, Patent Document 1).

FIG. 5 shows a planar warming tool described in Patent Document 1. As shown in FIG. As shown in the figure, a heater wire 4 in which two heating wires 2 and 3 are arranged via a temperature-sensitive resin layer 1, a diode 5 connected to one end of the heating wires 2 and 3, and a heating wire 2 A temperature control switch 6 connected to the other end of the heater, a diode 7 connected to the other end of the heating wire 3, a temperature fuse 8 connected to the cathode side of the diode 7, and the other end of the temperature control switch 6 and the temperature fuse 8. It is composed of a connected AC power source 9 and an emergency cut-off circuit 10 that operates when the heater wire 4 is abnormal and drives the temperature fuse 8.
JP-A-4-206379

  However, in the conventional configuration, since the heating wires 2 and 3 are connected in series, it may be possible to configure with about 50 W like a laid blanket, but it is 100 W to 200 W like a hanging blanket, a lap or a carpet. When the above is required and a large heating area is required, the resistance value of the heating wires 2 and 3 of the heater wire 4 is reduced, and the total length is also increased, and the units of the heating wires 2 and 3 are increasingly increased. Since the resistance value of the length becomes small, the heating wires 2 and 3 require a wire having a large cross-sectional area. In particular, it is very difficult to form a heater wire by spirally winding, and the breaking strength due to bending is also reduced. End up. Further, since it is housed in a small controller case close to a sealed state, there is a problem that the problem of heat generation of the diodes 5 and 7 through which the entire current flows cannot be ignored.

  The present invention solves the above-described conventional problems, and provides a planar warmer that can be configured for a high-watt heater wire, has low internal heat generation, and reduces electromagnetic waves generated from the heater wire. Objective.

  In order to solve the above-described conventional problems, the sheet heating device of the present invention is configured such that one end of the first heating wire of the heater wire is connected to an AC power source, and the other end is powered via the first rectifying element in the forward direction. Connect one end of the second heating wire located on the same end side as one end of the first heating wire connected to the control element to the AC power supply, and connect the other end to the second rectifying device in the reverse direction. Connect one end of the first heating wire to the AC power supply connected to the power control element, and connect the one end side connection part of the second heating wire connected to the power control element to the temperature detection part through the third rectifying element in the reverse direction. The temperature of the temperature sensitive layer is detected on the cycle side opposite to the energization cycle side of the first heating wire and the second heating wire of the AC power supply.

  As a result, the first heating wire and the second heating wire are each connected in parallel to the AC power supply. Therefore, when the same power is taken out, the resistance value is four times larger than that of each heating wire connected in series. This is possible. Therefore, the heating wire can be a high-watt heater wire without reducing the resistance value of the unit length, that is, with a wire having a small cross-sectional area. In addition, the current flowing through the first rectifying element and the second rectifying element is half that of the series connection when the same power setting is used, and the heat generation amount of the first rectifying element and the second rectifying element is also half. Become. Naturally, since the currents flowing through the first heating wire and the second heating wire are in opposite directions, the electromagnetic waves can be canceled out.

  The planar warming tool of the present invention can be configured for a high-watt heater wire, has little internal heat generation, and can reduce electromagnetic waves generated from the heater wire.

  According to a first aspect of the present invention, there is provided an AC power supply, a heater wire having a temperature-sensitive layer formed between the first heating wire, the second heating wire, and both the heating wires, and a power control element for energizing the AC power supply to the heater wire. A temperature detection unit for detecting the temperature of the temperature sensing layer of the heater wire, and a control unit for processing the signal of the temperature detection unit to control the power control element, wherein the heater wire has one end of the first heating wire. Connected to AC power supply, the other end is connected to the power control element through the first rectifying element in the forward direction, and the second heating wire is located on the same end side as one end of the first heating wire connected to the AC power supply One end of the second heating line is connected to the power control element, the other end is connected to an AC power source connected to one end of the first heating line through the second rectifying element in the reverse direction, and the second heating line connected to the power control element Connect the one end side connection part to the temperature detection part through the third rectifier element in the reverse direction, and The first heating wire and the second heating wire are obtained by using a sheet heating device configured to detect the temperature of the temperature sensing layer on the cycle side opposite to the energization cycle side of the first heating wire and the second heating wire. Since each of them is connected in parallel to the AC power source, if the same power is taken out, the resistance value can be four times as large as that of each of the heating wires connected in series. Therefore, the heating wire can be a high-watt heater wire without reducing the resistance value of the unit length, that is, with a wire having a small cross-sectional area, and the heater wire can be easily configured and the disconnection strength can be secured. In addition, the current flowing through the first rectifying element and the second rectifying element is half that of the series connection when the same power setting is used, and the heat generation amount of the first rectifying element and the second rectifying element is also half. Become. Naturally, since the currents flowing through the first heating wire and the second heating wire are in opposite directions, the electromagnetic waves can be canceled out.

  According to a second invention, in particular, in the first invention, a heating resistor is connected in series with the third rectifier element, and a temperature interrupting element thermally coupled to the heating resistor is connected in series to an AC power source, so that the heating tool main body When a part of the heater is locally kept, etc., when the heater wire temperature reaches the fusing temperature of the temperature sensitive layer, the first heating wire and the second heating wire are brought into contact with each other, the heating resistor generates heat, and the temperature is cut off. The element can be disconnected to stop energization.

  In a third aspect of the invention, in particular, in the first aspect of the invention, the current flowing to the power control element is detected by the current detection unit, and the detected conduction current is a current of either the first heating line or the second heating line. In such a case, the power control element is turned off, so that an abnormal temperature rise of the warming tool body can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 and 2 show a planar warming tool according to Embodiment 1 of the present invention.

  In FIG. 1, a heater wire 14 having a string-like structure in which a temperature sensitive layer 13 is formed between the first heating wire 11 and the second heating wire 12 is shown. By arranging the heater wire 14 having the string-like structure in a surface shape on the body of the warming tool, a surface warming tool such as a laid blanket, a hanging blanket, a knee lap, or a carpet is formed.

  In FIG. 2, one end c of the first heating wire 11 of the heater wire 14 is connected to the a side of the AC power supply 15, and the other end d is connected to the power control element 17 through the first rectifier element 16. One end e of the second heating wire 12 located on the same end side as the one end c of the first heating wire 11 connected to the a side is connected to the power control element 17, and the other end f is reversed to the second rectifying device 18. It connects to the a side of AC power supply 15 which connected the end c of the 1st heating wire 11 through the direction. The first rectifying element 16, the second rectifying element 18 and the power control element 17 are connected in a direction in which the first heating wire 11 and the second heating wire 12 are energized when the a side of the AC power supply 15 is at a positive voltage. Further, the third rectifying element 19 is connected toward the one end e side connecting portion of the second heating wire 12 connected to the power control element 17, and the other end of the third rectifying element 19 is connected to the temperature detecting unit 20. The temperature detection unit 20 includes a transistor 21 having a base connected to the b side of the AC power supply 15 and a collector connected to the third rectifier 19, a capacitor 22, and a resistor 23, and detects the temperature of the temperature sensitive layer 13. . And the control part 24 which processes the temperature signal detected by the temperature detection part 20 and controls the power control element 17 is comprised.

  About the planar warming tool comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, on the positive cycle side in which the a side of the AC power supply 15 is a positive voltage, the first heating wire 11 and the second heating wire 12 are respectively connected in parallel to the AC power supply 15, and further, the a side of the AC power supply 15 is positive. Energize on the positive cycle side, which is the voltage. The power control element 17 turns on and off the energization of the first heating wire 11 and the second heating wire 12 by a signal from the control unit 24. Then, the control unit 24 determines on / off of the power control element 17 from the temperature signal voltage Vt of the temperature detection unit 20. Next, the temperature detection unit 20 includes a transistor 21 when the b side of the AC power supply 15, which is the cycle side opposite to the energization cycle side of the first heating line 11 and the second heating line 12, is positive, that is, on the negative cycle side. When the transistor 21 is turned on when a temperature signal current flows from the base of the transistor to the emitter, the third rectifying element 19, the second heating line 12, the temperature sensing layer 13, the first heating line 11, and the AC power supply 15 side, Almost all of the current flows through the collector, and a DC temperature signal voltage Vt is output by the capacitor 22 and the resistor 23. Since the temperature signal voltage Vt varies depending on the impedance of the temperature sensitive layer 13, the temperature of the planar warming tool is determined by controlling the temperature signal voltage Vt with the control unit 24.

  As described above, in the present embodiment, the first heating wire 11 and the second heating wire 12 are connected in parallel to the AC power supply 15 respectively. The resistance value can be four times as large as that of the line. From another point of view, when the power is set to 50 W in the series connection, each resistance value is 50 Ω, and when this 50 Ω heating wire is connected in parallel, the power that can be taken out is 200 W, which enables four times the power setting. . Therefore, the heating wire can be made into a high-watt heater wire 14 without reducing the resistance value of the unit length, that is, with a wire having a small cross-sectional area, the heater wire 14 can be easily configured, and disconnection strength can be secured. Further, the current flowing through the first rectifying element 16 and the second rectifying element 18 is half the current of the series connection when the same power setting is used, and the heat generation amounts of the first rectifying element and the second rectifying element are also It becomes half. Naturally, since the currents flowing through the first heating wire and the second heating wire are in opposite directions, the electromagnetic waves can be canceled out.

(Embodiment 2)
FIG. 3 shows a planar warming tool in Embodiment 2 of the present invention. The same elements as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  As shown in the figure, the sheet heating device in the present embodiment has a heating resistor 25 connected in series with the third rectifying element 19, and a temperature interrupting element 26 thermally coupled to the heating resistor 25 is connected in series with the AC power supply 15. Connected.

  About the planar warming tool comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, when the temperature of the surface warmer main body rises abnormally due to, for example, a failure of the power control element 17 or local heat retention of the main body, when the temperature rise value reaches the melting temperature of the temperature sensitive layer 13, the temperature sensitive layer 13 The first heating wire 11 and the second heating wire 12 come into contact with each other. When the first heating wire 11 and the second heating wire 12 come into contact, on the negative cycle side where the b side of the AC power supply 15 becomes a positive voltage, the emitter from the base of the transistor 21, the heating resistor 25, the third rectifying element 19, and then A short current flows to the a side of the second heating wire 12, the first heating wire 11, and the AC power supply 15, the heating resistor 25 generates heat due to this short current, and the temperature cutoff element 26 thermally coupled to the heating resistor 25 is disconnected. And turn off the power.

  It is also possible to connect diodes 27 and 28 in parallel to the base and emitter of the transistor 21 and to allow a short current to flow through the diodes 27 and 28 when the transistor 21 is open due to the short current.

  As described above, in the present embodiment, the heating resistor 25 and the temperature blocking element 26 thermally coupled to the heating resistor 25 are connected to the path of the temperature detection unit 20, thereby causing an abnormal temperature rise of the heater wire 14. A short circuit between the first heating wire 11 and the second heating wire 12 can be detected to stop energization, and electromagnetic wave can be reduced and a safe sheet heating tool can be provided.

(Embodiment 3)
FIG. 4 shows a planar warming tool in Embodiment 3 of the present invention. The same elements as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  As shown in the figure, the sheet heating device in the present embodiment detects the energization current to the power control element 17 by the current detection unit 23, and the detected energization current is the first heating wire 11 or the second heating wire. The power control element 17 is turned off when any one of the currents 12 is obtained.

  About the planar warming tool comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, when one of the first heating wire 11 or the second heating wire 12 is disconnected, the effective area of the temperature sensing layer 13 for detecting the temperature is reduced, and the space between the first heating wire 11 and the second heating wire 12 is reduced. Impedance increases. If the impedance increases, it is regarded as a low temperature and the power control element 17 is kept on, and the temperature of the heating wire that is not disconnected becomes higher than a predetermined set temperature. Therefore, when the energization current of the power control element 17 is detected by the current detection unit 29 and the detected energization current becomes one of the currents of the first heat generation line or the second heat generation line, the power control element 17 Can be forcibly turned off.

  As described above, in the present embodiment, the first heating wire 11 or the second heating wire 12 is disconnected by detecting the energizing current of the first heating wire 11 and the second heating wire 12 with the current detection unit 29. Can be detected, and an abnormal temperature rise of the surface warmer body can be prevented.

  As described above, the planar warming device according to the present invention can be configured for a high-watt heater wire, has little internal heat generation, and can reduce electromagnetic waves generated from the heater wire. It can be applied to applications such as carpets that require high wattage as well as hanging blankets and knees.

The perspective view which shows the heater wire structure of the planar heating tool in Embodiment 1 of this invention. Circuit configuration diagram of coplanar warmer The circuit block diagram of the planar warming tool in Embodiment 2 of this invention The circuit block diagram of the planar warming tool in Embodiment 3 of this invention Circuit diagram of a conventional surface heating device

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 1st heating wire 12 2nd heating wire 13 Temperature sensing layer 14 Heater wire 15 AC power supply 16 1st rectification element 17 Power control element 18 2nd rectification element 19 3rd rectification element 20 Temperature detection part 24 Control part 25 Heating element 26 Temperature shut-off element 29 Current detector

Claims (3)

AC power source, heater wire having a temperature-sensitive layer formed between the first heating wire, the second heating wire, and both the heating wires, a power control element for energizing the AC power source to the heater wire, and the temperature sensitivity of the heater wire A temperature detection unit that detects the temperature of the layer; and a control unit that processes the signal of the temperature detection unit to control the power control element, and the heater wire connects one end of the first heating wire to an AC power source, Connect the other end to the power control element via the first rectifying element in the forward direction, and connect the one end of the second heating line located on the same end side as the one end of the first heating line connected to the AC power supply to the power control element The other end, connected to an AC power source connected to one end of the first heating line through the second rectifying element in the reverse direction, and one end side connection portion of the second heating line connected to the power control element, Connect the third rectifier element to the temperature detector through the reverse direction, and the first heating wire of the AC power supply Preliminary structure and the planar Todan device for detecting the temperature of the temperature-sensitive layer in the second heating wire energization cycle side opposite cycle side. The planar warmer according to claim 1, wherein a heating resistor is connected in series with the third rectifying element, and a temperature interrupting element thermally coupled to the heating resistor is connected in series to an AC power source. A configuration in which the power control element is turned off when the energization current to the power control element is detected by the current detection unit and the detected energization current becomes one of the first heating wire and the second heating wire. The planar warming tool according to claim 1.

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