KR100709095B1 - Safety device of heating wire - Google Patents

Abstract

The present invention relates to a safety device using a metal shield surrounding the outer circumferential surface of the heating wire in order to block an electric field exposed to the outside of the magnetic field heating wire used for a heater such as electric blanket, electric yoke, electric steamer, the configuration of the present invention A first heating wire and a second heating wire wound on an NTC thermistor layer or an insulating layer surrounding the first heating wire, and a metal shield wound on a constant temperature melting or synthetic resin insulating layer surrounding the second heating wire and surrounding the outside of the metal shield. In the non-inductive (non-electromagnetic, non-magnetic) heating wire comprising a shell insulating layer, the heating operation by a single-phase two-wire AC power source connected between the first heating wire and the second heating wire, the metal shield is a short circuit detection unit It is characterized in that the grounding to the ground wire side of the two-phase AC power supply line through.

The present invention reduces the thickness of the insulating resin layer between the second heating wire and the metal shield in the non-induction heating wire, thereby making the thickness of the heating wire thin, flexible, and reducing the production cost. In addition, when the insulation wire breaks down between the second heating wire and the metal shield and the heating wire becomes overheated and melts, the ground wire is automatically cut off or the power current is cut off so that the induction heating wire used for electric bedding, etc. functions as a non-electromagnetic wave and operates safely. It has the effect of having.

Description

Safety Device of Non-magnetic Heating Wire {Safety Device of Heating Wire}

1 is a circuit diagram of a non-electromagnetic wave heating line.

2 is a circuit diagram of a thermostat and a heating line of the present invention.

3 is a circuit diagram of another thermostat and a heating wire of the present invention.

4 is a circuit diagram showing various configurations of the short circuit detection unit of the present invention.

5 is a block diagram of a single-phase three-wire and single-phase two-wire power supply circuit.

6 is another circuit diagram of the thermostat and the heating wire of the present invention.

7 is another circuit diagram of the thermostat and the heating wire of the present invention.

<Description of Symbols for Main Parts of Drawings>

1: ventricle 2: 1st heating wire

3: NTC thermistor layer 3a: resin insulating layer

4: second heating wire 5, 5a: constant temperature molten resin insulating layer

6: metal shield 7: outer insulation layer

8: Temperature sensor 10: Short circuit detection resistor

11: temperature fuse 12: resistance

13: photocouple 14: constant voltage diode

15: short circuit detection, short circuit overcurrent blocking capacitor 16: solenoid coil

17 magnetic proximity switch 18 magnetoresistive element

C: Power Controller D1, D2: Rectifier

SW: Selection switch

The present invention relates to a safety device using a metal shield surrounding the outer circumferential surface of the heating wire to block the electric field exposed to the outside of the magnetic field heating wire used in the heater, such as electric blanket, electric yoke, electric steamer.

The heating wire used for a heating wire is doubled, and the heating wire is made to cancel an induced magnetic field by making two heating wires flow a current in opposite directions mutually. In addition, the temperature of the heating wire can be sensed by itself and compared with the temperature set by the user, and the temperature can be adjusted.Insulating synthetic resin or NTC thermistor is inserted between the first heating wire and the second heating wire to shield electromagnetic waves and induction magnetic fields. The heating wire which arrange | positions a 1st heating wire and a 2nd heating wire in the opposite direction, and the various shielding means is developed in the outer side. In particular, a heating wire is newly conceived by using a metal shield wound on the outside of the second heating wire to shield the electric field from leaking out to the outside.

An example of such heating lines will be described with reference to the drawings. 1 is a circuit diagram of a non-electromagnetic wave heating line. Referring to FIG. 1, the ventr 1 is wound with a first heating wire 2 connected to one side of the power supply, surrounds the first heating wire 2, and an NTC thermistor (Negative Temperature Coefficient) having a lower resistance value as the temperature increases. the outermost outer layer including a thermistor (3), a second heating wire (4) wound on the outer circumferential surface of the NTC thermistor (3), and a metal shield (6) surrounding the second heating wire (4). (7) is covered. The first heating wire 2 and the second heating wire 4 are arranged side by side or parallel to each other.

When the AC input power is turned on, the line half cycle of the AC cycle outputs a change in the temperature resistance value of the NTC thermistor 3 between the first heating wire 2 and the second heating wire 4 to the rectifier for detecting the temperature voltage. . The temperature detection signal current passes through the first heating wire 2 and flows back from the NTC thermistor 3 to the second heating wire 4.

At this time, since the temperature detection signal current flowing in the first heating wire 2 and the second heating wire 4 is opposite to each other, the magnetic field is canceled and the temperature detection signal current flows in the magnetic fieldless state. In addition, an electric field leaking outward of the second heating wire 4 is primarily shielded, but in the case of an electric field leaking out between them, the metal shield 6 is shielded. The metal shield 6 must be grounded separately.

Conventionally, in order to shield the electric field and minimize the thickness of the heating wire, a method of omitting an insulating layer between the second heating wire 4 and the metal shield 6 is used. In this case, the longer the heating wire, the internal resistance of the metal shield is used. The increase and the increase in the voltage between the metal shields has the disadvantage that the electric field blocking attenuation rate is lowered. However, the above configuration is provided with a constant temperature molten resin insulating layer 5 to solve this disadvantage.

Referring to the connection diagram of the lower part of FIG. 1, the heating current is inputted to the first heating wire 2 and is turned u-turn, and exits through the second heating wire 4. The outer side of the metal shield 6 is completely enclosed, and since the metal shield 6 is separately grounded, all charged electric charges are discharged.

Since the heating wire can detect and heat the temperature without a separate temperature sensor by the action of the NTC thermistor, when the heating wire is overheated to a high temperature, the heating wire can stop the heating operation by itself and adjust the temperature. However, in beddings such as electric blankets, electric yokes, and electric steamers that are in close contact with the human body and there is always a danger of fire, the function of ensuring stability is important. In the event of a short circuit, it is desirable to further attach a safety device to block the flow of current itself.

Specifically, the hot melt resin insulating layer 5 between the second heating wire 4 and the metal shield 6 is melted or broken so that the second heating wire 4 and the metal shield 6 are short-circuited to each other. In this case, a sudden resistance is generated and a risk of fire or electric shock occurs. At this time, the insulation state between the second heating wire 4 and the metal shield 6 is monitored, and in case of an emergency, the power is quickly cut off to provide a high resistance. There is a need for a simple and rapid safety device to prevent current flow through this generated state.

SUMMARY OF THE INVENTION An object of the present invention is to provide a simple safety circuit configuration for quickly blocking the flow of overheating current due to a short circuit between a second heating wire and a metal shield in bedding including a non-electromagnetic heating wire.

In addition, in bedding heating wire that needs thin thickness and flexibility, it detects the insulation performance and abnormality of the insulation layer wound on the second heating wire in order to minimize the increase in thickness by wrapping the grounded metal shield to block the electric field. It is an object of the present invention to provide a safety device that allows the insulating layer to be made thinner with a minimum thickness without being excessively thick.

In addition, it is intended to reduce the thickness of the insulating layer, to reduce the raw material and to minimize the manufacturing cost.

The construction of the present invention for achieving the above object comprises a first heating wire and a second heating wire wound on the synthetic resin insulating layer surrounding the first heating wire, the metal shield wound on the synthetic resin insulating layer surrounding the second heating wire And a shell insulation layer surrounding the outside of the metal shield, wherein the safety device is used for a non-electromagnetic wave heating wire that is heated by a single-phase two-wire AC power source connected between the first heating wire and the second heating wire. The metal shield is connected in series with the short circuit detection unit and is connected to the ground side of two wires of the single-phase two-wire AC power supply.

Another configuration of the present invention includes a first heating wire and a second heating wire wound on the NTC thermistor layer surrounding the first heating wire, and the metal shield wound on the hot melt or synthetic resin insulating layer surrounding the second heating wire and the It includes an outer shell insulating layer surrounding the outside of the metal shield, the half cycle is used to detect the temperature by the AC power connected between the first heating wire and the second heating wire, and the half cycle is used for the non-electromagnetic heating wire for heating operation In the safety device, the metal shield is connected in series with the short circuit detection unit, characterized in that connected to the ground side of the two wires of the single-phase two-wire AC power supply.

The short circuit detection unit may include a short circuit detection resistor connected between the ground ground and the metal shield. The short circuit detection unit may include a temperature fuse connected between a ground ground and the metal shield. The short circuit detection unit may include a photocouple connected in parallel with a short circuit detection resistor connected between the ground and the metal shield.

The short circuit detection unit may include a short circuit detection and a short circuit overcurrent blocking capacitor connected between the ground and the metal shield. The short circuit detection unit may include a photo coupler connected in parallel with the short circuit detection and short circuit overcurrent blocking capacitor.

The short circuit detection unit may include a solenoid coil connected between a ground ground and the metal shield. The short circuit detection unit may include a magnetic proximity switch at a position proximate to the solenoid coil. The short circuit detecting unit may include a magnetoresistive element at a position proximate to the solenoid coil.

Another configuration of the present invention includes a first heating wire and a second heating wire wound on the synthetic resin insulating layer surrounding the first heating wire, the metal shield wound on the synthetic resin insulating layer surrounding the second heating wire and the metal shield A safety device including an outer insulation layer surrounding the outside and used for a non-electromagnetic heating wire that is heated by an AC power source connected between the first heating wire and the second heating wire, wherein the heating wire has an AC power input selection switch. The AC power supply is connected to the single-phase two-wire or single-phase three-wire, the metal shield is provided with a short-circuit detection unit on the ground line side of the single-phase two-wire when using the single-phase two-wire AC power by the AC power input selection switch, When using a wired AC power source is characterized in that the short circuit detection unit provided on the hotline side is selected.

Another configuration of the present invention includes a first heating wire and a second heating wire wound around the NTC thermistor layer surrounding the first heating wire, and the metal shield wound on the low-temperature melting or synthetic resin insulating layer surrounding the second heating wire and the It includes a shell insulation layer surrounding the outer surface of the metal shield, the safety of being used in the non-electromagnetic heating wire that detects the temperature half cycle and the half cycle by the AC power connected between the first heating wire and the second heating wire In the apparatus, an AC power input selection switch is connected to the heating wire, the AC power supply is a single phase two wire type or a single phase three wire type, and the metal shield is connected to the AC power input selection switch using a single phase two wire type AC power supply. The short circuit detection unit is provided on the ground line side of the line, and when the single phase three-wire AC power supply is used, the short circuit detection unit provided on the hot line side is selected. .

Hereinafter, the configuration of the present invention will be described in detail with reference to embodiments of the present invention shown in the accompanying drawings.

2 is a circuit diagram of a thermostat and a heating line of the present invention. Referring to FIG. 2, the short circuit detection unit 30 is connected to a line where the metal shield 6 is grounded. When the current controlled by the power controller 20 flows through the first heating wire 2, it is turned in the temperature detector 40, and flows through the second heating wire 4. At this time, the electric charges that are charged through the second heating wires 4 and leaked electric field are exposed to the outside through the fusion-melt resin insulating layer 5, which is blocked by the metal shield 6 wound outside. . The blocked charge goes out along the metal shield 6 to grounded ground.

The hot melt resin insulating layer 5 wound on the outside of the second heating wire 4 is a synthetic insulating resin such as PVC, nylon, Teflon, silicon, PP, PE, etc., and the hot melt insulating resin is melted at a constant temperature. It means that the melting point and the property change point are set.

Therefore, the constant temperature molten resin insulating layer 5 has a change in physical properties at a predetermined temperature. If the second heating wire 4 is in an overheated state, the constant temperature molten resin insulating layer 5 melts or is damaged and the second heating wire 4 is changed. ) And the metal shield 6 are short-circuited to each other, a current flows through the metal shield 6, and a voltage of 20 to 40 V is applied to both ends, and a resistance is applied. The short-circuit detection unit 30 is formed in this portion so that the voltage can be detected and controlled. The short circuit detection unit 30 serves to block the energization when excessive voltage is detected. Therefore, when the internal heating wire is overheated, the low-temperature molten resin insulating layer 5 is melted, and serves to cut off the current so that it is no longer overheated.

3 is a circuit diagram showing another thermostat and a heating line of the present invention. Referring to FIG. 3, the short-circuit detection unit of the present invention does not use a thermistor as in the configuration of claim 1, and simply disposes the resin insulating layer 3a between the first heating wire 2 and the second heating wire 4. It can also be used for a heating wire that directly connects (R) the ends of the first heating wire 2 and the second heating wire 4. In general, in this case, the temperature detection is provided, instead of having a separate temperature sensor 8 to measure the temperature of the heating wire.

4 is a circuit diagram showing various configurations of the short circuit detection unit of the present invention. Referring to FIG. 3, an embodiment for performing voltage detection and disconnection operation through various configurations is illustrated.

(a) is a system in which the short circuit detection unit 30 between both ends A-B uses the short circuit detection resistor 10. If current flows through the short-circuit detection resistor 10, it is disconnected due to overheating. That is, a high power consumption is applied to the resistance of the low power consumption to disconnect. Since this system disconnects only the ground line of the metal shield 6, it only interrupts the overcurrent by the metal shield 6, and does not disconnect the power supply itself.

(b) is a method using the temperature fuse (11). The temperature fuse 11 is a system in which the heat fuse 11 is disconnected due to the heat generation phenomenon caused by the energization of the short-circuit detection resistor 10. The thermal fuse 11 is connected to energize or disconnect the power supply. When the thermal fuse 11 is disconnected, the thermal fuse 11 cuts off the electricity supply to the entire power supply.

(c) is a method of using the photo coupler (13). This is because when the photocouples SCR, TRIAC, TR, CDS, and LOGIG 13 are used, signals are transmitted to the input light emitting side, the output light receiving side, and light, and thus are mutually insulated so that circuit control is easy. (d) is a method of additionally connecting the light emitting diode overcurrent limiting constant voltage diode 14 in parallel to prevent damage caused by overvoltage to the photocouple 13.

(e) is a system using the short circuit detection and the short circuit overcurrent blocking capacitor 15. When the short-circuit detection and short-circuit overcurrent blocking capacitor 15 have a small capacity, the short-circuit detection and short-circuit over-current blocking capacitor 15 have high electrical resistance values even when the metal shield is shorted, so that short current does not flow to prevent overcurrent. Done. In particular, in the half-wave current heating method, since the half-wave is a direct current, the short-wave detection and short-circuit overcurrent blocking capacitor 15 cannot pass through. This method also disconnects only the ground line of the metal shield 6, thus only interrupting the overcurrent caused by the metal shield 6, but not the power supply itself. The reason for using such a method as (a) and (e) is that the object can be easily achieved with only one component. (f) and (g) is a method of using the photocouple 13, the overall operation is the same as the description of (c), (d).

When the photocouple 13 and the short circuit detection resistor 10 or the short circuit detection and short circuit overcurrent blocking capacitor 15 are connected in parallel, an overvoltage is applied to the photocouple 13 to prevent damage. do.

(h), (i), and (j) use the solenoid coil 16. The magnetic proximity switch 17 is provided in the solenoid coil 16 as shown in (i), or the magnetoresistive element 18 is provided as shown in (j). The magnetic proximity switch 17 is a device in which the switch is opened and closed by a magnetic field induced by the solenoid coil 16.

Since the magnetoresistive element 18 is made of a semiconductor and has three terminals like a transistor, when the voltage is supplied to the magnetoresistive element 18, the current value is changed by the magnetic signal and the voltage is output. The gate of the SCR TRIAC is driven to break the fuse.

Since the magnetoresistive element 18 is insulated from the detection unit in the same way as the photocouple, the circuit can be arbitrarily applied, so that the heating power can be controlled by adding an auxiliary circuit or the fuse can be disconnected. Such an insulated configuration has the advantage of being able to be coupled to any circuit part, and the non-insulating configuration is restricted in the circuit configuration.

5 is a block diagram of single-phase three-wire and single-phase two-wire power supply circuits, and FIGS. 6 and 7 are circuit diagrams. Referring to FIG. 5, there is a single-phase three-wire 220V power source (a) and a single-phase two-wire 220V power source (b) that are generally transmitted to homes. As shown in (a), 220V power flows to the heating line through the temperature controller 50 at both ends of the power line in the single-phase three-wire type, and at this time, the neutral wire is grounded (N) on the supply power side, and between the temperature controller and the heating line. The power controlled by the temperature controller is applied to the ground, and is grounded by a processing ground line between the temperature controller and the electric mat. Referring to (b), in the case of the single-phase two-wire system, one power supply line is grounded, and 220 V power is supplied to both ends of the power supply unit.

6 and 7, in the present invention, it is possible to select the single-phase two-wire and single-phase three-wire type through the selection switch SW (single-phase two-wire type when connected to E, single-phase three-wire type when connected to F). In the case of the single-phase three-wire type, a virtual ground is formed through the capacitors 21 and 22, and the metal shield 6 is connected thereto to block the electric field. In this case, a short circuit is detected at a portion where the voltage of the capacitor 21 serving as the short circuit detection unit increases from 110 V to 220 V, or the voltage at the capacitor 22 connected between the second heating wire 4 and the metal shield 6. What is necessary is just to detect that voltage falls falling from 110V to 0V.

When disconnection, short, or overheating occurs, the disconnection operation short current I is applied to the fuse connected to the triac 60 to disconnect the fuse. In this case, the short detection unit includes a magnetoresistive element 18 whose signal is changed by the resistor 10 or the solenoid 16, which is connected to the triac 60. Unexplained reference is a protective resistor 62.

The capacitor 21 has an internal capacitor capacitance value between the second heating wire 4 and the metal shield 6, and the capacitor 22 has the same capacitance value as the capacitor 21. When the two capacitors have the same capacitance value, the 220V voltage is divided into 110V and the voltage difference between the ground point and the virtual ground point becomes 0V. The potential difference between the ground point and the virtual ground point has a voltage difference of 0V due to voltage bisector and an alternating phase angle of phase alternating current, and a voltage difference of 0V due to the phase angle also becomes 0V potential for both voltage and phase. If the voltage is 110V using the capacitor 21 as a resistor, the potential cannot be 0V due to the AC phase difference between the ground point and the virtual ground point. The resistance and the AC square wave phase difference are 90 degrees, and as a result, the metal shield becomes zero potential by the virtual ground, and the electric field is blocked.

Referring to the operation of the short circuit detection unit according to the above configuration, when the second heating wire is overheated or the second heating wire and the metal shield are short-circuited (shorted) due to the failure of the constant temperature molten resin insulating layer, between the metal shield and the ground wire The short circuit detection unit detects a change in voltage. At this time, the ground wire of the metal shield may be disconnected by the resistance, or the heating wire itself may be disconnected to prevent fire or electric shock due to overheating.

Such a configuration of the present invention can be freely modified and added by those skilled in the art within the scope of the claims, and the scope thereof is not limited due to the description of the above embodiments.

The present invention, in the heating wire that can automatically adjust the temperature by sensing the temperature of the heating wire, when the insulation resin between the second heating wire and the metal shield is broken or melted automatically the ground wire or cut off the electric current bedding It has an effect of improving the safety and stability of the heating wire and the temperature controller used in the flow.

In addition, even if the thickness of the insulating resin surrounding the second heating wire is configured to be thin, the safety is guaranteed, the overall thickness of the heating wire is thinner and has the effect of reducing the raw material.

Claims (12)

A second heating wire wound around a first heating wire and a synthetic resin insulating layer surrounding the first heating wire, It includes a metal shield wound on the synthetic resin insulating layer surrounding the second heating wire and the outer shell insulating layer surrounding the outside of the metal shield, In the safety device used in the non-electromagnetic wave heating wire for heating operation by a single-phase two-wire AC power source connected between the first heating wire and the second heating wire, The metal shield is connected in series with the short-circuit detection unit, the safety device of the electromagnetic wave heating line, characterized in that connected to the ground side of the two wires of the single-phase two-wire AC power supply. A second heating wire wound around a first heating wire and an NTC thermistor layer surrounding the first heating wire, It includes a metal shield wound on the hot melt or synthetic resin insulating layer surrounding the second heating wire and the outer shell insulating layer surrounding the outside of the metal shield, In the safety device used in the non-electromagnetic wave heating wire that the half cycle detects the temperature by the AC power source connected between the first heating wire and the second heating wire, and the half cycle is heating operation, The metal shield is connected in series with the short-circuit detection unit, the safety device of the electromagnetic wave heating line, characterized in that connected to the ground side of the two wires of the single-phase two-wire AC power supply. The method of claim 1 or 2, wherein the short circuit detection unit: And a short circuit detection resistor connected between the ground and the metal shield. The method of claim 1 or 2, wherein the short circuit detection unit: And a thermal fuse connected between the ground and the metal shield. The method of claim 1 or 2, wherein the short circuit detection unit: And a photocoupler connected in parallel with a short-circuit detection resistor connected between the ground and the metal shield. The method of claim 1 or 2, wherein the short circuit detection unit: And a short circuit detection and a short circuit overcurrent blocking capacitor connected between the ground and the metal shield. The method of claim 6, wherein the short circuit detection unit: And a photocoupler connected in parallel with the short circuit detection and short circuit overcurrent blocking capacitors. The method of claim 1 or 2, wherein the short circuit detection unit: And a solenoid coil connected between the ground and the metal shield. The method of claim 8, wherein the short circuit detection unit: And a magnetic proximity switch in a position proximate to the solenoid coil. The method of claim 8, wherein the short circuit detection unit: And a magnetoresistive element in a position proximate to the solenoid coil. A second heating wire wound around a first heating wire and a synthetic resin insulating layer surrounding the first heating wire, It includes a metal shield wound on the synthetic resin insulating layer surrounding the second heating wire and the outer shell insulating layer surrounding the outside of the metal shield, In the safety device used in the non-electromagnetic wave heating wire heating operation by the AC power source connected between the first heating wire and the second heating wire, AC power input selection switch is connected to the heating wire, The AC power source is a single phase two wire type or a single phase three wire type, The metal shield is provided with a short-circuit detection section on the ground line side of the single-phase two-wire line when the single-phase two-wire AC power is used by the AC power input selection switch, and selects the short-circuit detection section provided on the hot line side when the single-phase three-wire AC power supply is used. Safety device for electromagnetic wave heating line characterized in that. A second heating wire wound around the first heating wire and the NTC thermistor layer surrounding the first heating wire, It includes a metal shield wound on the low-temperature melting or synthetic resin insulating layer surrounding the second heating wire and the outer shell insulating layer surrounding the outside of the metal shield, In the safety device used for the non-electromagnetic wave heating wire that the half cycle detects the temperature and the half cycle is heated by the AC power connected between the first heating wire and the second heating wire, AC power input selection switch is connected to the heating wire, The AC power source is a single phase two wire type or a single phase three wire type, The metal shield is provided with a short-circuit detection section on the ground line side of the single-phase two-wire line when the single-phase two-wire AC power is used by the AC power input selection switch, and selects the short-circuit detection section provided on the hot line side when the single-phase three-wire AC power supply is used. Safety device for electromagnetic wave heating line characterized in that.

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