JP2009162454A - Electric warmer - Google Patents

Abstract

Electromagnetic waves generated from a heating element can be suppressed by flowing currents in opposite directions to the first heating line and the second heating line of the heating element, and the first heating line and the second heating line Provided is an electric warming tool capable of ensuring safety when any one of them is in a partially disconnected state.
An electric heating device in which a first heating wire and a second heating wire are connected in series, and currents flowing in opposite directions flow in the first heating wire and the second heating wire, respectively. Based on the comparison result between the voltage between the input terminal T1 and the input terminal T3 and the voltage between the input terminal T2 and the input terminal T3, one of the first heating wire 1 and the second heating wire 2 is in a half-broken state. When the abnormality detection circuit 9 and the abnormality detection circuit 9 detect that one of the first heating wire 1 and the second heating wire 2 is in a partially disconnected state, the first heating wire 1 and the second heating wire 1 An electric warming tool provided with the circuit breaker 10 which interrupts | blocks the electricity supply to the serial connection body of the heat wire 2. FIG.
[Selection] Figure 5

Description

  The present invention relates to an electric warming tool (for example, an electric carpet or an electric blanket).

  Here, an electric carpet will be described as an example of a conventional electric warming tool. FIG. 7 shows a schematic configuration example of a conventional electric carpet. The conventional electric carpet shown in FIG. 7 includes a heating element 4 having a first heating wire 1, a second heating wire 2, and a detection wire 3, a control circuit 5, a relay contact 6, and a fuse (temperature fuse or current fuse). 7).

  The detection line 3 of the heating element 4 is composed of a resistance line whose resistance value changes according to the ambient temperature. When a voltage is applied to both ends, the first heating line 1 and the second heating line 2 of the heating element 4 generate heat. Temperature is detected and a temperature detection signal is output. The control circuit 5 operates using the voltage output from the commercial AC power supply 8, and controls the relay contact 6 to be turned ON / OFF according to the temperature detection signal output from the detection line 3 of the heating element 4. The temperature of the electric carpet body is controlled by turning ON / OFF the energization of the first heating wire 1 and the second heating wire 2 and the commercial AC power supply 8. Further, the fuse 7 cuts off the power supply between the commercial AC power supply 8 and the control circuit 5 and the first heating wire 1 and the second heating wire 2 of the heating element 4 when overheating or overcurrent occurs due to a circuit abnormality or the like. It is a safety device.

  Further, in the conventional electric carpet shown in FIG. 7, the first heating wire 1 and the second heating wire 2 are arranged in parallel, and the first heating wire 1 and the second heating wire 2 are connected in series, Currents in opposite directions are passed through the first heating wire 1 and the second heating wire 2. Thereby, since the electromagnetic waves from the first heating wire 1 and the electromagnetic waves from the second heating wire 2 cancel each other, the electromagnetic waves generated from the heating element 4 can be suppressed.

Japanese Patent Laid-Open No. 10-144457 JP-A-4-236020 JP 2005-183018 A

  Here, as shown in FIG. 4, the first heating wire 1 and the second heating wire 2 are flexible and have flexibility, so as shown in FIG. A copper wire having a diameter of ~ 0.15 mm is spirally formed on the outer periphery of the core wire 17 by twisting together a plurality of wires (for example, 2 to 6 wires, in which three wires are shown in FIG. 4). A structure is provided in which an insulating coating 18 is provided around the winding. FIG. 4B is an enlarged cross-sectional view of the heating wire 16 as viewed from the direction of arrow D in FIG.

  However, even if the first heating wire 1 and the second heating wire 2 have a structure with excellent flexibility and flexibility as described above, the heating wire 16 is constituted by long-term use or external pressurization. The thin wire is broken. If all the thin wires are disconnected and the heating element wire 16 is completely disconnected, the power supply between the commercial AC power supply 8 and the first heating wire 1 and the second heating wire 2 of the heating element 4 is cut off at that time. No problem. On the other hand, for example, the exothermic element wire 16 is composed of three thin wires, and some of the thin wires are broken, such as a state where two of the three thin wire configurations are disconnected and one is not disconnected. Even if an unforeseen abnormality such as a high temperature or short spark occurs locally in the disconnected part, the abnormality is overheated or overheated to activate the fuse 7. Since the current does not reach, there is a possibility that the commercial AC power supply 8, the control circuit 5, and the first heating wire 1 and the second heating wire 2 of the heating element 4 are not cut off.

  In view of the above situation, the present invention can suppress electromagnetic waves generated from a heating element by flowing currents in opposite directions to the first heating line and the second heating line of the heating element. It aims at providing the electric warming tool which can ensure the safety | security when either a hot wire and a 2nd heating wire will be in a half-broken state.

  In order to achieve the above object, an electric warmer according to the present invention includes a heating element having a first heating wire and a second heating wire, and includes one end of a heating element wire of the first heating wire and the second heating wire. One end of the heating element wire is connected at a connection node, the first heating wire and the second heating wire are connected in series, and currents in opposite directions are connected to the first heating wire and the second heating wire. An electric warming tool through which the voltage between the connection node and the other end of the heating wire of the first heating wire, and the other end of the heating wire of the connection node and the second heating wire. An abnormality detection circuit that detects that one of the first heating wire and the second heating wire is in a half-broken state based on the comparison result, and the abnormality detection circuit When the first heating wire and the second heating wire are detected to be in a half-broken state, the first heating wire It has a configuration and a circuit breaker for interrupting the power supply to the series connection of the heating wire and the second electrical heating wire.

  According to such a configuration, currents in opposite directions flow through the first heating wire and the second heating wire of the heating element, so that electromagnetic waves generated from the heating element can be suppressed. Moreover, according to such a structure, when either a 1st heating wire and a 2nd heating wire will be in a half-disconnection state, the abnormality detection circuit will detect this, and a 1st heating wire and 2nd by a circuit breaker will be detected. Since energization to the serial connection body of a heating wire is interrupted | blocked, the safety | security when one of a 1st heating wire and a 2nd heating wire will be in a half-broken state can be ensured.

  Further, in the electric warming device having the above-described configuration, between the other end of the heating element wire of the first heating wire and the abnormality detection circuit and between the other end of the heating element wire of the second heating wire and the abnormality detection circuit. A semi-fixed resistor may be provided in at least one of them.

  According to such a configuration, even when there is a large variation in manufacture for each product, by adjusting the resistance value of the semi-fixed resistor, one end of the heating element wire of the first heating wire and the heat generation of the second heating wire are performed under normal conditions. The voltage between the connection node to which one end of the element wire is connected and the other end of the heating element wire of the first heating wire, one end of the heating element wire of the first heating wire, and one end of the heating element wire of the second heating wire The voltage between the connection node connected to the other end of the heating wire of the second heating wire can be made the same.

  Moreover, in the electric warming tool of each said structure, you may make the specification and structure of the exothermic element wire of the said 1st heating wire, and the exothermic element wire of the said 2nd heating wire the same.

  According to such a configuration, basically, under normal conditions, one end of the heating element wire of the first heating wire and one end of the heating wire of the second heating wire are connected to the heating element of the first heating wire. The voltage between the other end of the wire, one end of the heating element wire of the first heating wire, and one end of the heating wire of the second heating wire are connected to the other end of the heating wire of the second heating wire. The voltage between and becomes the same.

  Further, in the electric warming device having each of the above-described configurations, the first heating wire and the second heating wire each have an insulation coating for covering the heating element wire, and the insulation coating of the first heating wire and the second heating wire are provided. The insulating coating of the heat ray may be made of insulating materials having different bending performances.

  According to such a configuration, it is possible to reduce the possibility that the heating element wire of the first heating wire and the heating element wire of the second heating wire will be in a partially disconnected state at the same time.

  According to the electric warming device of the present invention, it is possible to suppress electromagnetic waves generated from the heating element by flowing currents in opposite directions to the first heating wire and the second heating wire of the heating element, and Safety can be ensured when either the hot wire or the second heating wire is in a partially disconnected state.

  Embodiments of the present invention will be described below with reference to the drawings. Here, as an electric warming tool according to the present invention, an electric carpet will be described as an example. For convenience of explanation, the same parts as those shown in FIG.

  FIG. 1 is an overall plan view of an electric carpet according to the present invention. In the electric carpet 11 according to the present invention, the carpet body 12 includes a front cloth and a back cloth, and the heating element 4 is arranged in a meandering manner between the front cloth and the back cloth of the carpet main body 12. A controller 13 for connecting both ends of the heating element 4 is provided at the corner of the carpet body 12 and the power cord 14 for connecting to a commercial AC power outlet (not shown) is connected to the controller. 13 is a structure extending from 13.

  In the present embodiment, a heating element having the same basic configuration as the heater wire proposed in Patent Document 3 is used as the heating element 4.

  FIG. 2 shows a cross-sectional view of the heating element 4. The heating element 4 is a cable having a structure in which an insulating sheath 15 is formed on the outer periphery of a bundle in which the first heating wire 1, the second heating wire 2, and the detection wire 3 are bundled together.

  In the heating element 4, the first heating wire 1 and the second heating wire 2 are adjacent to each other as shown in FIG. 2, and one end of the heating wire 16_1 of the first heating wire 1 is connected to the second heating wire 1 as shown in FIG. One end of the heating element wire 16_2 of the heating wire 2 is connected, and the first heating wire 1 and the second heating wire 2 are connected in series. By connecting the other end of the heating element wire 16_1 of the first heating wire 1 to one end of the commercial AC power supply 8 and connecting the other end of the heating element wire 16_2 of the second heating wire 2 to the other end of the commercial AC power supply 8, That is, by connecting the serial connection body of the first heating wire 1 and the second heating wire 2 to the commercial AC power supply 8, currents in opposite directions flow through the first heating wire 1 and the second heating wire 2, Since the electromagnetic waves from the first heating wire 1 and the electromagnetic waves from the second heating wire 2 cancel each other, the electromagnetic waves generated from the heating element 4 can be suppressed.

  The detection wire 3 is a signal wire 19 made of a single nickel fine wire having a diameter of about φ0.1 mm or a combination of two nickel fine wires having a diameter of about φ0.1 mm is wound around the outer periphery of the core wire 20 in a spiral, and an insulating coating 21 is formed around the signal wire 19. It is the structure which provided.

  Since each of the first heating wire 1 and the second heating wire 2 has flexibility and flexibility, as shown in FIG. 4, a thin wire having a diameter of about φ0.1 mm (for example, φ0.1 mm to φ0. 15 mm of copper wire) (for example, 2 to 6 wires, 3 cases are shown in FIG. 4) are wound around the outer periphery of the core wire 17 in a spiral, The structure is provided with an insulating coating 18 around. FIG. 4B is an enlarged cross-sectional view of the heating wire 16 as viewed from the direction of arrow D in FIG. Since the resistance value per unit length of the heating wire varies depending on the performance (size and rated power consumption) of the electric carpet 11 according to the present invention, the diameter and the number of the thin wires constituting the heating wire 16 are the present invention. The combination is suitable for the performance of the electric carpet 11.

  The resistance value of the series connection body of the first heating wire 1 and the second heating wire 2 is set so as to have a predetermined power consumption when an AC voltage having an effective value of 100 [V] is applied from the commercial AC power supply 8. However, the heating element wire 16_1 of the first heating wire 1 and the heating element wire 16_2 of the second heating wire 2 are set so that the resistance value of the first heating wire 1 and the resistance value of the second heating wire 2 are the same. The specifications and configuration are the same. On the other hand, the insulating coating 18_1 of the first heating wire 1 and the insulating coating 18_2 of the second heating wire 2 are made of different insulating materials so that the first heating wire 1 and the second heating wire 2 have different bending performances. Yes. For example, the insulating coating 18_1 of the first heating wire 1 is made of polyamide (melting point 175 ° C.), which is the same insulating material as the insulating coating 21 of the detection wire 3, and the insulating coating 18_2 of the second heating wire 2 is made of ethylene / tetrafluoroethylene ( Melting point 270 ° C.).

  FIG. 5 is a diagram showing a schematic configuration example of the electric carpet 11 according to the present invention. The electric carpet 11 according to the present invention shown in FIG. 5 is obtained by adding an abnormality detection circuit 9, a circuit breaker 10, resistors R1 to R3, and semi-fixed resistors R4 and R5 to the conventional electric carpet shown in FIG. It is a configuration. The control circuit 5 and the abnormality detection circuit 9 are stored in the controller 13.

  The detection line 3 of the heating element 4 is composed of a resistance line whose resistance value changes according to the ambient temperature. When a voltage is applied to both ends, the first heating line 1 and the second heating line 2 of the heating element 4 generate heat. Temperature is detected and a temperature detection signal is output. The control circuit 5 operates using the voltage output from the commercial AC power supply 8, and controls the relay contact 6 to be turned ON / OFF according to the temperature detection signal output from the detection line 3 of the heating element 4. The temperature of the electric carpet body is controlled by turning ON / OFF the energization of the first heating wire 1 and the second heating wire 2 and the commercial AC power supply 8. Further, the fuse 7 cuts off the power supply between the commercial AC power supply 8 and the control circuit 5 and the first heating wire 1 and the second heating wire 2 of the heating element 4 when overheating or overcurrent occurs due to a circuit abnormality or the like. It is a safety device.

  When the abnormality detection circuit 9 detects that one of the first heating wire 1 and the second heating wire 2 is in a half-broken state, the abnormality detection circuit 9 operates the circuit breaker 10, and the commercial AC power supply 8, the control circuit 5, the heating element. 4, the energization of the first heating wire 1 and the second heating wire 2 and the abnormality detection circuit 9 is cut off.

  One end of the heating element wire 16_1 of the first heating wire 1 and one end of the heating element wire 16_2 of the second heating wire 2 are connected by the connection node N1, and the connection node N1 is input to the abnormality detection circuit 9 via the resistor R3. The other end of the heating element wire 16_1 of the first heating wire 1 is connected to the input terminal T1 of the abnormality detection circuit 9 via the resistor R1 and the semi-fixed resistor R4, and the heating element of the second heating wire 2 is connected to the terminal T3. The other end of the line 16_2 is connected to the input terminal T2 of the abnormality detection circuit 9 through the resistor R2 and the semi-fixed resistor R5. The resistors R1 to R3 are high resistors for protecting the abnormality detection circuit.

When an AC voltage having an effective value of 100 [V] is applied from the commercial AC power source 8 to the series connection body 2 of the first heating wire 1 and the second heating wire 2, as shown in FIG. An AC voltage having an effective value of 100 [V] is applied from the commercial AC power supply 8 to the series connection body of the heating element wire 16_1 and the heating element wire 16_2 of the second heating wire 2. At this time, the heating element wire 16_1 of the first heating wire 1 and the heating element wire 16_2 of the second heating wire 2 have the same specifications and configuration as described above. if a second heating wire heating wire 2 16_2 is normal, basically, the voltage across V ₁₆ _ ₁ of the first heating wire of the heating wire 1 16_1, both ends of the second heating wire heating wire 1 16_2 Both voltages V ₁₆ _ ₂ have an effective value of 50 [V].

Then, an AC voltage having an effective value of 100 [V] is applied from the commercial AC power supply 8 to the series connection body of the heating element wire 16_1 of the first heating wire 1 and the heating element wire 16_2 of the second heating wire 2, and the first heating wire. when 1 of the heating wire 16_1 and the second heating wire heating wire 2 16_2 is normal, the input terminal of the input terminal T1- input terminal T3 between voltages V ₁ and the abnormality detection circuit 9 of the abnormality detecting circuit 9 T2 - so that the voltage V ₂ between the input terminal T3 become identical, corrected adjusting the resistance value of the semi-fixed resistors R4 and R5.

Due to deterioration of use for many years, one of the first heating wire 1 and the second heating wire 2 becomes a half-break, and as a result, the voltage V ₁ between the input terminal T1 and the input terminal T3 of the abnormality detection circuit 9 And the voltage V ₂ between the input terminal T2 and the input terminal T3 of the abnormality detection circuit 9 are not the same.

Therefore, the abnormality detecting circuit 9, the difference between the voltage V ₂ between the input terminals T2- input terminal T3 of the input terminal T1- input terminal T3 between voltages V ₁ and the abnormality detection circuit 9 of the abnormality detecting circuit 9 is equal to or higher than a predetermined value Then, it is determined that one of the first heating wire 1 and the second heating wire 2 is half-broken, and the circuit breaker 10 is operated to turn on the commercial AC power supply 8, the control circuit 5, and the heating element 4. The energization of the first heating wire 1 and the second heating wire 2 and the abnormality detection circuit 9 is cut off. Thereby, it is possible to prevent an unforeseen abnormality such as a high temperature or occurrence of a short spark locally at the disconnection portion, thereby ensuring safety.

  As described above, the insulating coating 18_1 of the first heating wire 1 and the insulating coating 18_2 of the second heating wire 2 are different from each other so that the first heating wire 1 and the second heating wire 2 have different bending performances. Since it is made of an insulating material, there is almost no possibility that the heating element wire of the first heating wire 1 and the heating element wire of the second heating wire 2 are in a semi-cut state at the same time. As described above, from the viewpoint of reliably detecting a half-break, it is preferable that the insulating coating 18_1 of the first heating wire 1 and the insulating coating 18_2 of the second heating wire 2 are made of different insulating materials. From the viewpoint of cost reduction and simplification of the manufacturing process, the insulating coating 18_1 of the first heating wire 1 and the insulating coating 18_2 of the second heating wire 2 may be made of the same insulating material.

  In the present embodiment, the heating element wire 16_1 of the first heating wire 1 and the heating element wire 16_2 of the second heating wire 2 have the same specifications and configuration, but adjustment with the semi-fixed resistors R4 and R5 is possible. Since it is possible, the specification and configuration of the heating element wire 16_1 of the first heating wire 1 and the heating element wire 16_2 of the second heating wire 2 may not be the same. In addition, when there is little manufacturing variation for each product and the range of adjustment with semi-fixed resistance may be small, or when adjustment with semi-fixed resistance is not required, the configuration with a single semi-fixed resistor or semi-fixed resistor is used. You may make it the structure which does not provide.

These are the whole top views of the electric carpet which concerns on this invention. FIG. 3 is a sectional view of a heating element. These are the block diagrams of a heat generating body. These are the block diagrams of a heating wire. These are figures which show the example of schematic structure of the electric carpet based on this invention. FIG. 6 is an excerpt of the relevant part of FIG. 5. These are figures which show the schematic structural example of the conventional electric carpet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st heating wire 2 2nd heating wire 3 Detection wire 4 Heating element 5 Control circuit 6 Relay contact 7 Fuse 8 Commercial AC power supply 9 Abnormality detection circuit 10 Circuit breaker 11 Electric carpet 12 Carpet body 13 Controller 14 Power cord DESCRIPTION OF SYMBOLS 15 Insulation sheath 16, 16_1, 16_2 Exothermic wire 17, 17_1, 17_2, 20 Core wire 18, 18_1, 18_2, 21 Insulation film 19 Signal line R1-R3 Resistance R4, R5 Semi-fixed resistance T1-T3 Input terminal

Claims (4)

A heating element having a first heating wire and a second heating wire, wherein one end of the heating wire of the first heating wire and one end of the heating wire of the second heating wire are connected by a connection node; In the electric warming tool in which the heating wire and the second heating wire are connected in series, and currents in opposite directions flow through the first heating wire and the second heating wire,
Comparing the voltage between the connection node and the other end of the heating element wire of the first heating wire with the voltage between the connection node and the other end of the heating element wire of the second heating wire; An abnormality detection circuit that detects that either the first heating wire or the second heating wire is in a half-broken state based on a comparison result;
When the abnormality detection circuit detects that either the first heating wire or the second heating wire is in a half-broken state, energization to the series connection body of the first heating wire and the second heating wire is performed. An electric warming tool comprising: a circuit breaker for interrupting.   Semi-fixed resistors are provided between the other end of the heating element wire of the first heating wire and the abnormality detection circuit and at least one of the other end of the heating element wire of the second heating wire and the abnormality detection circuit. The electric warmer according to claim 1.   The electric heating device according to claim 1 or 2, wherein the heating element wire of the first heating wire and the heating wire of the second heating wire have the same specifications and configuration.   The first heating wire and the second heating wire each have an insulation coating for covering the heating element wire, and the insulation coating of the first heating wire and the insulation coating of the second heating wire have different bending performances. It is an insulating material, The electric warming tool in any one of Claims 1-3.

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