JP2013098138A - Cord-shaped heat generation line device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cord-shaped heat generation line device which can obtain a highly accurate and stable temperature control function and a highly safe line short circuit protection function with little variation by alternately and spirally winding a temperature detection strand and a short circuit detection strand around the outer circumference of a polymer layer at a constant pitch regardless of one-line type cord-shaped heat generation line and separating a temperature control circuit from a line short circuit protection circuit, and is manufactured at low cost.SOLUTION: A heat generation strand 2 is spirally wound around a core 1. A polymer layer 3 is formed around the core. A temperature detection strand 4 and a short circuit detection strand 6 are alternately kept at a constant pitch and spirally wound around the outer circumference of the polymer layer 3 in the form of cutting into the polymer layer 3. An insulation coating layer 5 is further formed thereon. The temperature detection strand 4 and the short circuit detection strand 6 are spatially separated, which thereby can respectively independently perform temperature control by the temperature detection strand 4 and line short circuit protection by the short circuit detection strand 6 with high accuracy and without variations.

Description

  The present invention relates to a cord-like heating wire device used for a sheet heating device such as an electric blanket or an electric carpet.

  In general, cord-like heating lines used for sheet heating devices such as electric blankets and electric carpets are well known. In particular, the cord-like heating system used for electric carpets at the beginning is composed of cord-like sensor wires and cords. The structure is called a two-wire system composed of a heater wire, and its structure is shown in FIG.

  In the figure, a cord-shaped sensor wire 100 includes a core 1a of a fiber bundle such as polyester fiber, an inner electrode wire 2a in which a copper or copper alloy conductor is spirally wound around the outer periphery of the core 1a, A polymer heat-sensitive layer 3a formed by extruding a polymer heat-sensitive resin on the outer periphery of the inner electrode wire 2a, and an outer electrode element wire in which a copper or copper alloy conductor is spirally wound on the outer periphery of the polymer heat-sensitive layer 3a. 4a and an insulating coating layer 5a formed by extruding a polyvinyl chloride resin or the like on the outermost periphery.

  If necessary, a polyester tape may be spirally twisted between the outer electrode wire 4a and the insulating coating layer 5a to provide a barrier layer against plasticizer migration from the insulating coating layer 5a. Some of the inner electrode wires 2a and the outer electrode wires 4a are reversely arranged, and the inner electrode side electrode wires 2a and the outer electrode wires 4a are made of a special alloy.

  Here, the electrical characteristics with respect to the temperature of the polymer thermosensitive layer 3a show a so-called negative temperature coefficient thermistor characteristic in which the AC impedance decreases as the temperature rises, and the B constant representing the sensitivity performance is about 8000K to 11000K. . The polymer thermosensitive layer 3a does not necessarily have an inherent melting point.

  In the cord-like sensor wire 100 having such a configuration, a change in AC impedance due to a temperature change is taken out as an electrical signal from both ends of the inner electrode strand 2a and the outer electrode strand 4a and used for temperature control.

  Next, the cord-like heater wire 101 has the same shape as that shown in FIG. 3, but the material used is different. In the figure, a core 1b of a fiber bundle such as a polyester fiber, a heating element wire 2b in which a copper or copper alloy conductor is spirally wound around the outer periphery of the winding core 1b, and an outer periphery of the heating element wire 2b. A polymer layer 3b formed by extruding a polymer resin, a short-circuit detecting element wire 4b in which a copper or copper alloy conductor is spirally wound around the outer periphery of the polymer layer 3b, a polyvinyl chloride resin or the like on the outermost periphery And an insulating coating layer 5b formed by extrusion molding.

  Here, the polymer layer 3b has an inherent melting point. When the polymer layer 3b is overheated, the polymer layer 3b is melted, and the exothermic element wire 2b and the short-circuit detecting element wire 4b come into contact with each other. work. Note that the line-to-line short-circuit protection function referred to here is a function that shuts off the main power supply in a non-returning manner in combination with other components such as a thermal fuse when a line short-circuit occurs, preventing a fire due to abnormal overheating. say.

  If necessary, a polyester tape may be spirally twisted between the short-circuit detecting element wire 4b and the insulating coating layer 5b to provide a barrier layer against plasticizer migration from the insulating coating layer 5b. In addition, a part of the heating element wire 2b and the short-circuiting detection element wire 4b are reversed.

  These two cord-like sensor wires 100 and cord-like heater wires 101 are wired substantially in parallel and connected to the temperature control unit, and the operation of temperature control and line short-circuit protection is realized by the circuit connection shown in FIG. .

In FIG. 4, the signal from the cord-like sensor line 100 is divided to a low voltage by resistors R1 and R2, further smoothed by a diode D3 and a capacitor C1, and applied to the negative terminal of the voltage comparator U1 as a small DC component. The input voltage is compared with a reference voltage Vref1 corresponding to a preset temperature and output from the voltage comparator U1, and the opening / closing of the power control switch SW is driven to control energization to the heating element wire 2b.
Here, the symbol STB is a stabilized power source whose voltage is lowered, and is supplied to the temperature control unit. (The same shall apply hereinafter.)

On the other hand, as shown in FIG. 4, both ends of the short-circuit detecting element wire 4b are short-circuited and the cord-like heater wire 101 is short-circuited, and each AC 100V is connected via the temperature fuse integrated resistor RF1 and two diodes. Is connected to the other pole to form a short circuit protection circuit between lines.
Here, F1 is a thermal fuse, RF1 is a thermal fuse integrated resistor, and D1 and D2 are rectifier diodes.

The operation of the short circuit protection circuit between the cord-like heater wires 101 shown in FIG. 4 is as follows.
When the temperature control unit to which the cord-like sensor wire 100 is connected is damaged and becomes uncontrollable, the power control switch SW remains ON, the energization of the cord-like heater wire 101 to the heating element wire 2b is continuous, and the whole Since the polymer layer 3b is melted at an inherent melting point due to the overheating state, the exothermic element wire 2b and the short-circuit detecting element wire 4b come into contact with each other, “AC power supply N point → 2b → 4b → RF1 → D1 → F1 → AC power supply. An AC half-wave current flows through two paths of “H point” and “AC power supply H point → F1 → 2b → 4b → RF1 → D2 → AC power supply N point”, and the temperature fuse integrated resistor RF1 is heated with large electric power. In the predetermined time, the thermal fuse is blown, the power supply is shut off, and a final protection circuit is configured to prevent a fire.
Here, the H point and N point of the AC power source are names indicating positions on the circuit diagram, and do not include electrical meaning. The same operation is performed even if the diodes D1 and D2 are connected in opposite directions.

The advantages of the line short circuit protection circuit are as follows.
(1) The resistance value of the short-circuit detecting element wire 4b can be made much smaller than that of the temperature fuse integrated resistor RF1, and can be industrially made smaller than the resistance value of the heat generating element wire 2b. The variation in the fusing time of the thermal fuse can be made very small, but the extent to which it is made depends on the cost.
(2) By connecting and using both ends of the short-circuit detecting element wire 4b, the combined resistance of the short-circuit detecting element wire 4b becomes equal to or less than ¼ of the original resistance value when both ends are open regardless of the short-circuit position. Reducing the resistance of the short-circuit detecting element wire 4b shown in the item (1) brings about a large reduction effect of four times or more with respect to the resistance value of the temperature fuse integrated resistor RF1.
(3) Since the AC half-wave current flows through the two paths in the temperature fuse integrated resistor RF1, variation in power consumption due to the short-circuit position between the lines and the ON / OFF state of the power control switch SW can be reduced. In addition, since the cord-like heater wire 101 is spatially separated from the cord-like sensor wire 100, it is possible to provide a highly safe and stable line-to-line short-circuit function without electrical mutual interference.

Next, Table 3 shows a rough calculation value of the power consumption of the temperature fuse integrated resistor RF1 based on FIG.
Here, the resistance value of the heating element wire 2b is 28.6Ω, the resistance value of the temperature fuse integrated resistor RF1 is 180Ω, and the resistance value of the short-circuit detecting element wire 4b is 1 / of the resistance value of the temperature fuse integrated resistor RF1. Considering a standard of about 2 and cost, it is set to 90Ω corresponding to about 3 times the resistance value of the heating element wire 2b. Since the forward voltage drop of the diodes D1 and D2 is small, it is omitted from the calculation (the same applies hereinafter).

  According to Table 3, in the two-wire cord-like heater wire 101 (conventional example 1), the temperature fuse integrated resistor RF1 according to each mode of the line short-circuit position and the ON / OFF state of the power control switch SW. In actual use, the difference in power consumption is only 13.9 W ÷ 9.6 W = 1.4 times.

The above is because the line short-circuit protection function functions regardless of whether the power control switch SW is ON or OFF, and therefore, the maximum value in each mode works effectively for the power consumption of the temperature fuse integrated resistor RF1.
Here, assuming that the fusing time of the thermal fuse F1 depends on the energy consumption, the fusing time in the case of 9.6 W with respect to the power consumption of 13.9 W is expected to increase only by 1.4 times. The time is generally reasonable for the above forecast.

As described above, the conventional two-wire cord-like heating wire consisting of the cord-like sensor wire and the cord-like heater wire has an excellent configuration that can completely separate the temperature control function and the safety protection function. The difference in fusing time depending on the position can be accommodated in an acceptable range, and it is an extremely safe form, but because it uses two filaments, the cost is very high and it is not economical, Since the polymer thermosensitive layer 3a has a large change over time, there has been a serious problem that stable temperature control cannot be performed over a long period of time.
Patent Documents 1 to 6 are cited as similar in appearance and configuration to the above description.

JP-A-48-55480 JP-A-5-3071 JP-A-5-306819 JP-A-6-5175 JP-A-6-124771 Japanese Patent Laid-Open No. 7-216174

  In recent years, in the electric blanket and electric carpet, with the increase in area, the fabric and cover are thicker from the viewpoint of vision and touch, while the wiring density of the cord-shaped heating wire per unit area is reduced, the strong cost of the market Due to the demand for stable temperature control with little change over time over a long period of time, a heating wire structure called a one-wire cord-like heating wire has rapidly become widespread. There are many variations in protection functions, and the final protection function that prevents the occurrence of fires does not have sufficient safety, which is a big problem.

  A one-wire cord-shaped heating wire 102 shown in FIG. 3 includes a winding core 1c of a fiber bundle such as polyester fiber, and a heating element wire 2c obtained by spirally winding a copper or copper alloy conductor around the winding core 1c. A polymer layer 3c formed by extruding a polymer resin on the outer periphery of the heating element wire 2c, a temperature detection element wire 4c in which a conductor such as nickel is spirally wound on the outer periphery of the polymer layer 3c, and an outermost periphery The insulating coating layer 5c is formed by extruding a polyvinyl chloride resin or the like.

  If necessary, a polyester tape may be spirally twisted between the temperature detection element wire 4c and the insulating coating layer 5c to provide a barrier layer against plasticizer migration from the insulating coating layer 5c. Some of the heating element wires 2c and the temperature detection element wires 4c are reversely arranged.

  In the cord-like heating wire 102 having such a structure, the temperature change due to heating changes the resistance value of the temperature detecting element wire 4c made of nickel having a positive temperature coefficient, and the change is converted into an electric signal and taken out. It is used for temperature control. Unlike polymer thermosensitive layers that use ionic conduction, the temperature detection element using nickel wire has a highly accurate and stable resistance value and temperature coefficient, realizing stable and highly accurate temperature control over a long period of time. is made of.

In the cord-like heating wire 102, the polymer layer 3 c has a unique melting point, and when it is overheated, the polymer layer 3 c melts, and the heating wire 2 c and the temperature detection wire 4 c come into contact with each other, so-called line short circuit. Works as a protective function. That is, in the one-wire cord-like heating wire 102, the temperature detection wire 4c also serves as a short-circuit detection wire.
Some polymer layers 3c have a negative temperature coefficient thermistor characteristic in which the impedance decreases as the temperature rises.

The temperature control and line short-circuit protection operation of the one-wire cord-shaped heating wire 102 is realized by circuit connection as shown in FIG.
In the temperature control operation, the resistance change of the temperature detection element wire 4c is divided by resistors R1 and R2, input to the negative terminal of the voltage comparator U1, and compared with a reference voltage Vref1 corresponding to a preset temperature. Output from the comparator U1, the opening and closing of the power control switch SW is driven, and energization to the heating element wire 2c is controlled.
Here, the symbol STB is a stabilized power source whose voltage is lowered, and is supplied to the temperature control unit.

  In the line short-circuit protection operation, the anodes of the diodes D1 and D2 are respectively connected to both ends of the temperature detection element wire 4c, and the cathodes of the diodes D1 and D2 are connected together to one end of the temperature fuse integrated resistor RF1. The other end of the integrated resistor RF1 is connected to one end of AC100V.

  Here, when the temperature control unit is damaged and becomes uncontrollable, the power control switch SW remains ON, energization to the heating element wire 2c is continued, and the whole is overheated, so that the polymer layer 3c Is melted at a specific melting point, the heating element wire 2c and the temperature detection element wire 4c come into contact with each other, and the current flows through the path of “AC power supply N point → 2c → 4c → D1 or D2 → RF1 → F1 → AC power supply H point”. The thermal fuse integrated resistor RF1 is heated, the thermal fuse is blown out within a predetermined time, the power supply is shut off, and a final protection circuit for preventing the occurrence of a fire is formed.

  Of particular importance in the above-described line-to-line short-circuit function is that the protective function must operate in a state where there is little variation regardless of the position of the cord-like heating wire 102 where a line-to-line short-circuit occurs. In order to satisfy this requirement, in the circuit connection shown in FIG. 5, the influence of the short-circuit position between the lines is reduced in the direction of decreasing the resistance value of the temperature detection element wire 4c and the temperature fuse integrated resistor RF1, and the temperature fuse integrated type. Efforts have been made to ensure a uniform fusing time of the thermal fuse F1 by uniform heating of the resistor RF1, but the resistance value of the temperature detection wire 4c, which also serves as a short-circuit detection wire, is changed to a temperature fuse integrated resistor RF1. It is economically impossible to make it smaller than the resistance value.

  Table 3 shows a rough calculation value of the power consumption of the temperature fuse integrated resistor RF1 based on FIG. Here, the resistance value of the temperature detection element wire 4c is 1176Ω at 60 ° C., the resistance value of the temperature fuse integrated resistor RF1 is 180Ω, and the resistance value of the heating element wire 2c is 28.6Ω. Other conditions are the same as in the case of the two-wire system.

  According to Table 3, in the one-wire cord-like heating wire 102 (conventional example 2), the temperature fuse integrated resistor RF1 in each mode of the line short-circuit position and the ON / OFF state of the power control switch SW is used. In actual use, there is a difference of 13.9 W / 1.9 W = 7.3 times in power consumption. Here, assuming that the fusing time of the thermal fuse F1 depends on the energy consumption, the fusing time in the case of 1.9 W is expected to be 7.3 times the power consumption 13.9 W, but the actually measured fusing time is Is generally reasonable to the expectation.

  Further, assuming an extreme case where the resistance value 1176Ω of the temperature detection element 4c at 60 ° C. is reduced to 588Ω, which is ½, the thermal control integrated resistor is calculated when the power control switch SW is OFF. The power consumption of RF1 is about 3.9 W, and the fusing time is expected to be shortened to 13.9 W / 3.9 W = 3.6 times and approaches the allowable range.

  However, if the resistance value of the temperature detection element wire 4c is halved, the temperature signal is halved. Therefore, the current flowing through the temperature detection element wire 4c must be doubled, which lowers the voltage. Increases the heat generation of the constant electrified power supply, raises the surface temperature of the storage case of the temperature controller, and causes discomfort and safety problems in use.

  Next, as another structure of the one-wire cord-shaped heating wire, a heating wire having a structure as shown in FIG. 6 has been proposed (Patent Document 5).

  In the drawing, a core 1d of a fiber bundle such as a polyester fiber, a heating element wire 2d in which a copper or copper alloy conductor is spirally wound around the outer periphery of the winding core 1d, and an outer periphery of the heating element wire 2d. A polymer thermosensitive layer 3d formed by extruding a polymer thermosensitive resin, and a temperature detecting element wire 4d and a bare overheat detecting element element 6d are provided on the outer periphery of the polymer thermosensitive layer 3d with an interval between them. It is spirally wound at a constant pitch, and its outer periphery is insulated with an insulating coating layer 5d to form a cord-like heating wire 103. Here, the polymer thermosensitive layer 3d has a so-called negative temperature coefficient thermistor characteristic in which the impedance decreases as the temperature rises.

  Based on the structural diagram of FIG. 6, the insulated temperature detection element wire 4 d is electrically independent from the other portions, and can detect only a pure temperature detection signal, and the overheat signal of the polymer thermosensitive layer 3 d is Since the overheat signal can be detected purely between the exothermic element wire 2d and the overheat detection element line 6d without mixing the temperature detection signal, the overheating proceeds and the polymer thermosensitive layer 3d melts, and the exothermic element line 2d and the overheat detection element line 6d It is shown that the overheating signal can cut off the energization of the heating element wire 2d at a temperature much before the occurrence of a so-called line short circuit where the wire contacts, thereby preventing the line short circuit.

This will be described in more detail with reference to the circuit diagram of FIG.
In the figure, the signal from the temperature detecting element wire 4d coated with insulation is divided by resistors R1 and R2 and input to the negative terminal of the voltage comparator U1-A, which corresponds to a preset temperature. Compared with the reference voltage Vref1 and output from the voltage comparator U1-A, the opening and closing of the power control switch SW is driven to control the energization to the heating element wire 2d.

Next, the signal from the overheat detection element 6d is divided by resistors R2 and R3 and input to the negative terminal of the voltage comparator U1-B, which corresponds to a preset temperature long before the occurrence of a short circuit between lines. Is compared with the reference voltage Vref2 and output from the voltage comparator U1-B, and the opening / closing of the power control switch SW is driven to control the energization to the heating element wire 2d.
As described above, the main purpose of Patent Document 5 is that the polymer thermosensitive layer 3d is melted and can be prevented before the occurrence of a short circuit between the exothermic element wire 2d and the overheat detecting element wire 6d.

  However, even if the above-mentioned precautions are taken, the temperature control unit may break down, and when the polymer thermosensitive layer 3d melts and a line short circuit occurs between the heating element wire 2d and the overheat detection element wire 6d. The circuit connection for the line short-circuit protection that enables the above-mentioned main purpose of “signal separation” can be provided as shown in FIG. It can be configured only in the same manner as the case where the popular one-wire cord-like heating wire 102 described in FIG. 5 is used, and a line-to-line short-circuit protection operation with little variation cannot be obtained.

  Of course, the overheat detection element 6d can be used exclusively for line-to-line short-circuit protection with high sensitivity in which an AC half-wave current flows through two paths as in the two-wire type. A short circuit prevention circuit cannot be constructed. Therefore, since the insulation coating process of the temperature detection element 4d which is the object of Patent Document 5 does not need to exhibit its function, it is not possible to use the overheat detection element exclusively for the short-circuit detection element with the structure of Patent Document 5. This creates a contradiction that must be extremely uneconomical.

  The object of the present invention is to provide a constant pitch alternately on the outer circumference of the polymer layer with a temperature detection wire and a short-circuit detection wire, each of which is made of a suitable material, although it is a one-wire cord-like heating wire. Highly accurate and stable temperature control function with less variation and high safety by keeping the temperature control circuit and the line short circuit protection circuit tightly wound and spirally wound into the polymer layer An object of the present invention is to provide a cord-like heating wire device which can obtain a line short-circuit protection function and is economically excellent.

  In order to achieve the above object, a cord-like heating wire device according to claim 1 according to the present invention is a heating element wire spirally wound around a winding core at a predetermined pitch, and an alternating current is applied to both ends, and is closely attached to the heating element wire. A polymer layer that is arranged and melts at a predetermined temperature, and a temperature detection element that is spirally wound so as to bite into the polymer layer while maintaining a constant pitch on the outer periphery of the polymer layer to maintain a constant pitch A cord-like heating wire device comprising two conductors composed of a wire and a short-circuit detecting element, and a coating layer that insulates the two conductors. When the other end of the resistor is connected to both poles of the AC power source via two diodes, and the heating element wire and the short-circuit detection element wire are short-circuited at an arbitrary position, the heating element Before the AC applied to the wire side is short-circuited A path is formed through the wire connected to the short-circuit detection element wire to the thermal fuse integrated resistor, and a current of the magnitude leading to fusing flows through the path to heat, and the thermal fuse is cut in a short time for safety. It is characterized by ensuring.

  According to a second aspect of the present invention, there is provided a cord-like heating wire device comprising two temperature sensing wires and a short-circuiting sensing wire which are spirally wound with a constant pitch between the outer circumferences of the core. A conductor, a polymer layer press-molded to bite into the two conductors, a heating element wire spirally wound at a predetermined pitch on the outer periphery of the polymer layer that melts at a predetermined temperature, and alternating current applied to both ends; A cord-like heating wire device having a coating layer for insulating the heating wire, wherein both ends of the short-circuit detection wire are connected to one end of a temperature fuse integrated resistor, and the other end of the resistor is two When the heating element wire and the short-circuit detection element wire are short-circuited at an arbitrary position, each connected to both poles of an AC power source via a diode, the short-circuit detection is performed through a portion where an alternating current applied to the heating element side is short-circuited. Through the wire connected to the element wire. Is formed a path flowing through the chromatography's integral resistors, heated flow magnitude of the current leading to fusing to said path, characterized in that to ensure a short time to cut the thermal fuse safety.

  According to a third aspect of the present invention, there is provided the cord-like heating wire device according to the first or second aspect, wherein each of the temperature detection wire and the short-circuit detection wire has a thickness or a diameter of 10 mm. % Or more and 50% or less is spirally wound so as to bite into the polymer layer.

  According to a fourth aspect of the present invention, there is provided the cord-like heating wire device according to the first, second or third aspect, wherein the polymer layer is made of a mixture of polyamide resin and polyamide elastomer. The melting temperature is 130 ° C. or higher and 190 ° C. or lower.

  The cord-like heating wire device according to claim 5 of the present invention is the cord-like heating wire device according to claim 1, 2, 3 or 4, wherein the temperature detecting element wire is a metal wire having a positive temperature coefficient. It is characterized by being.

  The cord-like heating wire device according to claim 6 of the present invention is the cord-like heating wire device according to any one of claims 1 to 5, wherein the two diodes have a temperature fuse integrated resistor on the same polarity side. The other pole side of each of the diodes is connected to each pole of an AC power source, and the other end of the temperature fuse integrated resistor is connected to both ends of a short-circuit detecting element wire.

  The cord-like heating wire device according to claim 7 of the present invention is the cord-like heating wire device according to any one of claims 1 to 6, wherein the resistance value of the short-circuit detecting element wire is a resistance integrated with a temperature fuse. It is less than the resistance value of the vessel.

Hereinafter, the configuration of the present invention will be described in detail.
The core wire used in the cord-like heating wire device of the present invention is a polyester fiber bundle, a polyimide fiber bundle, a glass fiber bundle, etc., but a polyester fiber bundle is preferable from the viewpoint of heat resistance, flexibility and cost, and is suitable for use. Accordingly, the fiber bundle is not particularly limited as long as it is excellent in heat resistance and flexibility, and may be a mixed bundle of various fibers.

The heating element wire spirally wound at a predetermined pitch used in the cord-like heating wire device of the present invention includes a pure copper wire, an alloy wire of copper and tin, or an alloy wire of copper and silver, and the shape is round. It can also be made into a linear shape or a thin plate shape, and they remain as a single wire, are stranded, or are spirally wound in multiple lines, but with a predetermined size and a predetermined resistance value Therefore, selection of the material and shape is not limited at all.
Here, the heating element wire is a conductor through which a current flows to generate heat, but also serves as one electrode that contacts the short-circuit detection element wire when a line short-circuit occurs.

  The temperature detection element wire and the short-circuit detection element wire used in the cord-like heating wire device of the present invention are spirally wound at a constant pitch with a mutual interval around the outer periphery of the polymer layer with the surface thereof being uninsulated and bare. However, since 10% or more and 50% or less of the thickness or diameter of each strand is spirally wound into the polymer layer and firmly fixed by the upper insulating coating layer, the cord-like heating wire Even if the wire is subjected to bending stress, the temperature detection element wire and the overheat detection element wire that are not covered with insulation do not come into contact with each other.

  The polymer layer used in the cord-like heating wire device of the present invention has a melting temperature of 130 ° C. or more and 190 ° C. or less from the surface temperature of products such as electric blankets and electric carpets and the heat resistance temperature of the cord-like heating wire. Preferably, a blend of a polyamide resin and a polyamide elastomer exhibiting relatively steep melting characteristics at 150 ° C. to 170 ° C. is suitable.

  Here, when the melting temperature of the polymer layer is 130 ° C. or less, the peak temperature of the exothermic wire may instantaneously rise to around 120 ° C. under normal temperature control, and when this occurs repeatedly, heat is generated in a short period of time. There is a high possibility that the element wire and the short-circuit detecting element are short-circuited. At 190 ° C. or higher, the heating element wire is overheated and smoke and kogation increase, which is not appropriate.

  In addition, the melting temperature of the polymer layer is 130 as described above from the relationship between the amount of biting of the temperature detection wire and the short-circuit detection wire into the polymer layer and the molding temperature and pressure of the insulating coating layer covering the both wires. The range of from 150 ° C. to 190 ° C., preferably from 150 ° C. to 170 ° C. is suitable.

  Furthermore, in order to deepen the bite into the polymer layer even when the molding temperature of the insulating coating layer is low, the mixture of polyamide resin and polyamide elastomer used in the cord-like heating wire device of the present invention, Polyalkylene oxide may be added, or a conductive agent may be blended in the polymer layer so as to have a so-called negative temperature coefficient thermistor characteristic in which the electrical impedance decreases with increasing temperature.

Even if the temperature detection wire and the short-circuit detection wire are in contact with each other, the short-circuit detection wire is connected to the AC power source via the diode and the temperature fuse integrated resistor. Therefore, the control circuit can easily detect the contact state, shut off the power source, and ensure safety.
Therefore, the temperature detecting element according to the present invention does not require a detailed process of insulating coating as shown in FIG.
In FIG. 2 of the present invention, the terminal voltage of R2 due to the presence or absence of a short circuit between the temperature detection wire and the short detection wire is about 0.9V when there is no short circuit through an appropriate smoothing circuit, and 0 when there is a short circuit. .4 to 0.5 V, and a clear discrimination ratio can be secured.

  The temperature detection element wire used in the cord-like heating wire device of the present invention is not particularly limited as long as it is a metal wire having a positive temperature coefficient, but among metals, the temperature coefficient is relatively high, and wire drawing and winding are performed. Nickel, which has a stable resistance value and temperature coefficient even when subjected to mechanical stress such as wire processing, has a positive temperature coefficient, linear resistance characteristics with respect to temperature, excellent reproducibility, and little change over time It is considered as a detection element wire.

  The two diodes used in the cord-shaped heating wire device of the present invention have the same polarity side connected to one end of the temperature fuse integrated resistor, and the other polarity side of the diode is connected to each pole of the AC power source. In both cases, the other end of the temperature fuse integrated resistor is connected to both ends of a short-circuit detecting element wire, and when the line is short-circuited, an AC half-wave current flows from the two paths to the temperature fuse integrated resistor and a large amount of power is applied. Configure a line-to-line short-circuit protection circuit that enables quick fusing. Here, as long as the above-described polarity connection reference is maintained, the forward and reverse directions of the two diodes are not particularly limited.

  The resistance value of the short-circuit detecting element wire used in the cord-like heating wire device of the present invention is preferably equal to or less than the resistance value of the temperature fuse integrated resistor, preferably less than 1/2 the resistance value of the temperature fuse integrated resistor. It is. In the case of the present invention, the resistance value of the short-circuit detecting element wire can be much smaller than the resistance value of the temperature fuse integrated resistor RF1, and industrially, it can be made smaller than the resistance value of the heating element wire. Whether it is reduced to the extent depends on the cost.

  A cord-like heating wire device is formed by extruding an insulating coating layer such as a vinyl chloride resin that is intimately adhered to the outer periphery of the temperature detection wire and the short-circuit detection wire, has high electrical insulation, and is flexible and inexpensive.

  According to the cord-like heating wire device of the present invention, the temperature detection wire and the short-circuit detection wire are spirally formed in such a manner that they are spaced apart from each other on the outer periphery of the polymer layer to maintain a constant pitch and bite into the polymer layer. Because it is wound, the short-circuit detection between the heating element and the short-circuit detection element can be detected by the short-circuit detection element alone, regardless of the temperature detection element, and the line-to-line short-circuit protection is quick and has little variation. Functions can be prevented to prevent local smoke and burns.

  According to the cord-like heating wire device according to the present invention, the temperature detection wire and the short-circuit detection wire are 10% to 50%, preferably 20% to 40% of the thickness or diameter of the polymer layer. Since it is wound spirally and firmly fixed by the upper insulation coating layer, even if the cord-like heating wire is subjected to bending stress, the temperature detection strand and the short-circuit detection strand are not in contact with each other Can be.

  According to the cord-like heating wire device of the present invention, a polyamide resin and a polyamide elastomer exhibiting relatively steep melting characteristics when the melting temperature of the polymer layer is 130 ° C. or higher and 190 ° C. or lower, preferably 150 ° C. or higher and 170 ° C. or lower. Thus, the final line-to-line short-circuit protection function can be flexibly ensured by selecting appropriate varieties and blends for the amount of biting, melting temperature, and melting time.

  According to the cord-like heating wire device of the present invention, the temperature sensing element is a metal wire having a positive temperature coefficient, so the temperature coefficient is small, but the temperature-resistance characteristic is linear and changes with time compared to the polymer thermosensitive layer. Is very small, so temperature control with high precision, stability, and reproducibility is possible.

  According to the cord-like heating wire device of the present invention, the two diodes have the same polarity side connected to one end of the temperature fuse integrated resistor, and the other polarity side of the diode is connected to each pole of the AC power source. The other end of the temperature fuse integrated resistor is connected to both ends of the short-circuit detecting element. When the line is short-circuited, an AC half-wave current flows from the two paths to the temperature fuse integrated resistor, and a line due to large power application Since the short-circuit protection circuit can be configured, the fusing time of the thermal fuse is shortened, and a significant improvement in safety can be ensured.

  According to the cord-like heating wire device according to the present invention, the resistance value of the short-circuit detecting element wire is set to be equal to or less than the resistance value of the temperature fuse integrated resistor, and preferably 1/2 or less. Therefore, it is less affected by the short-circuit position between the lines and the ON / OFF state of the power control switch, and can realize a fusing time with little variation and can greatly improve safety.

It is a figure which shows embodiment of the cord-shaped heating wire apparatus by this invention, and is the structure figure which abbreviate | omitted and showed a part of heating wire. It is a circuit diagram which shows embodiment of the circuit part of the cord-shaped heating wire apparatus by this invention. It is a figure which shows an example of the cord-shaped heat generating line of the conventional example 1 of 2 lines type, and the conventional example 2 of 1 line type, Comprising: It is the structure figure which abbreviate | omitted a part of heat generating line. It is a circuit diagram which shows an example of the circuit part of the cord-shaped exothermic line of the 2 wire type prior art example 1. It is a circuit diagram which shows an example of the circuit part of the cord-shaped heating wire of the conventional example 2 of 1 wire type. It is a figure which shows an example of the code | cord | chord heat | fever wire of the 1 line type prior art example 3, Comprising: It is the structure figure which abbreviate | omitted a part of heat | fever wire. It is a circuit diagram which shows an example of the circuit part of the cord-shaped heat generating line of the conventional example 3 of a 1-wire system.

Hereinafter, embodiments of the cord-like heating wire according to the present invention will be described in more detail with reference to the drawings. In addition, this invention is not limited to the following content, unless it deviates from the summary.
FIG. 1 shows one end of a cord-like heating wire 1H according to an embodiment of the present invention, and is a view in which a part of an insulating coating layer and a polymer layer are omitted.

  The cord-shaped heating wire 1H includes a winding core 1 of a fiber bundle such as glass fiber or polyester fiber, a heating element wire 2 in which a rectangular conductor of copper or copper alloy is spirally wound around the outer periphery of the winding core 1, and heat generation. A polymer layer 3 formed by extruding a polymer thermosensitive resin on the outer periphery of the strand 2, and a temperature detection strand 4 spirally wound at a constant pitch on the outer periphery of the polymer layer 3 with mutual spacing It is comprised from the short circuit detection strand 6 and the insulation coating layer 5 which extruded polyvinyl chloride etc. in the outermost periphery.

  Here, among the polyamide resins, the polymer layer 3 is preferably a blend of nylon 12 having a low water absorption rate and a polyamide / elastomer, and when the molding temperature of the insulating coating layer 5 is low, the blend may include polyethylene glycol or Polyalkylene oxide such as polyethylene oxide may be added to lower the softening point of the polymer layer 3. These materials are kneaded by a kneader or a multi-screw extruder to obtain a polymer layer 3 as an admixture. These materials may be charged and kneaded at one time, but may be sequentially charged and kneaded a plurality of times.

Further, on the outer periphery of the polymer layer 3, two conductors composed of the temperature detection element wire 4 and the short circuit detection element wire 6, each of which is 10% to 50% of the thickness or diameter of the polymer layer 3. In a state where they are bitten into each other, they are spirally wound at a constant pitch with a mutual interval. The depth of this biting is usually realized by tension management of the winding machine, but by adjusting not only the means but also the extrusion pressure of the insulating coating layer 5, a quantitatively stable biting amount can be obtained, It is an important construction method that leads the present invention to mass production and is one of the core.
In order to determine the amount of biting, there is a means of adjusting the extrusion temperature of the insulating coating layer, but the extrusion temperature is an important means of ensuring optimum fluidity depending on the material of the insulating coating layer, and this can be arbitrarily set. It is not preferable to change.

  Further, in order to prevent the plasticizer contained in the polyvinyl chloride resin mixture of the insulating coating layer 5 from moving to the polymer layer 3, the temperature detecting element 4, the short-circuit detecting element 6, and the insulating covering layer 5 A barrier layer in which a polyester tape is vertically attached may be provided.

Various data on the embodiment shown in FIG. 1 is as follows.
Material of the core 1: Polyester fiber bundle Material of the heating element wire 2: 0.7% tin copper alloy Dimensions of the heating element wire 2: Cross section 0.060 × 0.420 mm (flat conductor), pitch 0.86 mm
Material of polymer layer 3: Table 1
Dimension of polymer layer 3: thickness 0.33 mm
Material of temperature detection element wire 4: Nickel Dimensions of temperature detection element element 4: Section diameter φ0.080 mm (round wire conductor), pitch 0.86 mm
Material of short-circuit detecting element wire 6: 0.7% tin copper alloy Dimensions of short-circuit detecting element element 6: Section diameter φ0.083 mm (round conductor), pitch 0.86 mm
Material of insulating coating layer 5: Polyvinyl chloride resin admixture Dimensions of insulating coating layer 5: thickness 0.4 mm

  The polyvinyl chloride resin blend is a commercially available blend for power wires using heat-resistant polyvinyl chloride resin (VM-163, manufactured by Apco), and the polyamide resin is commercially available nylon 12 (3020X15, UBE) and polyamide 12 elastomer (9048X1, UBE) were used.

The materials of the three types of examples shown in Table 1 and the two types of conventional examples are kneaded with a kneader or a twin screw extruder to form a cord-shaped heating wire 1H having the structure shown in FIG. 1, which is cut to a length of 36 m. A sample for measurement was used.

A circuit configuration relating to an embodiment of the present invention is shown in FIG. 2, and the electrical values and operations of each component will be briefly described.
In the figure, the resistance value of the heating element wire 2 which is a component of the cord-shaped heating wire 1H having a total length of 36 m is 28.6Ω, and the resistance value of the temperature detection element wire 1 is 1176Ω at 60 ° C. (the temperature coefficient is 0. 0). 44% / ° C.), the resistance value of the short-circuit detecting element 6 is 90Ω, and the resistance value of the temperature fuse integrated resistor RF1 is 180Ω. 3 is a polymer layer, R1, R2, and R3 are fixed resistors, and R1 = 1.5 KΩF, R2 = 470ΩF, and R3 = 10 KΩ. C1 is an electrolytic capacitor, C1 = 10 μF, withstand voltage 16V, D1 and D2 are rectifier diodes 1N4004, U1 is a voltage comparator, and SW is a power control switch for controlling energization to the heating element wire 2 according to the result of the voltage comparator U1. STB is a stabilization circuit unit that supplies DC Vcc = 5V from AC 100V to the temperature control unit.

The operation of the circuit of FIG. 2 is as follows.
In the temperature control operation, the resistance change of the temperature detection wire 4 is divided by resistors R1 and R2, and input to the negative terminal of the voltage comparator U1, and compared with a reference voltage Vref1 corresponding to a preset temperature. Output from the comparator U1, the opening and closing of the power control switch SW is driven, and energization to the heating element wire 2 is controlled.

  In the line short-circuit protection operation, both ends of the short-circuit detecting element 6 are connected to one end of the temperature fuse integrated resistor RF1, and the anodes of the diodes D1 and D2 are connected to the other end of the temperature fuse integrated resistor RF1. When the cathode sides of the diodes D1 and D2 are connected to the respective poles of the AC power source and a short circuit between the lines occurs, an AC half-wave current flows through the temperature fuse integrated resistor RF1 through two paths.

  Table 3 shows a rough calculation value of the power consumption of the thermal fuse integrated resistor RF1 based on FIG. According to Table 3, in the cord-like heating wire 1H of Examples 1, 2, and 3 according to the present invention, the temperature fuse integrated resistor RF1 depending on the short-circuit position between the wires and the ON / OFF state of the power control switch SW. As in the case of the two-wire system, the power consumption is estimated to produce only a difference of 13.9 W ÷ 9.6 W = 1.4 times in actual use.

[Temperature control test]
The 36 m cord-like heating wire 1H is spread so as not to intersect, and the upper and lower sides are covered with a heat insulating material such as felt for measurement.
The positive input voltage Vref1 of the voltage comparator U1 is set in advance so that the average temperature of the temperature detection element 4 is controlled at 65 ° C., and the temperature is directly applied to the surface of the central position of the cord-like heating wire 1H whose temperature is controlled by energization. The temperature was measured by contacting the sensor. The results are shown in Table 2.

[Short line protection test between lines]
A line-to-line short-circuit test between the heating element wire 2 and the short-circuit detection element wire 6 accompanying the melting of the polymer layer 3 due to overheating of the cord-like heating wire 1H was performed in a pseudo manner as follows. In the circuit diagram of FIG. 2, the power control switch SW is set to the state shown in Table 2, and one end A2 and H2 of the heating element wire 2 and the short-circuit detection element wire 6 is forcibly short-circuited, and the heating element wire 2 The fusing time of the thermal fuse F1 was measured for the case where the center part of each of the short-circuit detecting wires 6 was forcibly short-circuited.
Table 2 shows the fusing time of Examples 1, 2, 3 and Conventional Example 1 (due to a short circuit between the heating element wire 2b and the short-circuit detection element wire 4b) and 2 (according to the heating element wire 2c and the temperature detection element wire 4c). Show.

[Measurement of the amount of wire biting]
In Examples 1, 2, and 3 and Conventional Examples 1 and 2, temperature detection element wire 4 (4c in Conventional Example 2) and short circuit detection to polymer layer 3 (3b and 3c in Conventional Examples 1 and 2, respectively) Table 2 shows the percentage of the average bite amount with respect to the wire diameter of the wire 6 (4b in the conventional example 1), the cross section of which was measured with a projector. Table 2 shows the presence / absence of contact between the two wires in the 180-degree bending test 10,000 times.

[Melting temperature test]
The melting / short circuit test of the polymer layer 3 by overheating the cord-shaped heating wire 1H was performed as follows. Both ends are fixed in a state where the central portion of the cord-shaped heating wire 1H cut to a length of 0.5 m is slackened, and the temperature is raised at a rate of 1 ° C./1 minute. Note that an extension wire is connected to the heating element wire 2 and the short-circuit detection element wire 6, and is connected to an ohmmeter outside the thermostat. During the temperature raising process, the resistance meter became zero ohms, and the temperature of the thermostatic chamber when the short circuit was detected was read as the melting temperature. Table 2 shows the melting temperatures for Examples 1, 2, and 3 and Conventional Example 1 (polymer layer 3b) and 2 (polymer layer 3c).

Evaluation for each measured value is as follows.
[Evaluation of temperature control test]
Looking at the variation in surface temperature in Table 2, there is no significant difference between the example and the conventional example, and even if the structure of the cord-like heating wire is changed according to the present invention, the temperature control performance is comparable to the conventional one. Was able to prove.

[Evaluation of line-to-line short-circuit protection test]
The value of the thermal fuse fusing time of the conventional example 1 of the two-wire type showed an excellent value that inherited the tradition, but the conventional example 2 of the one-wire type had a problem in the short circuit between the central portions of the cord-like heating wires. The value of 189 seconds with a slow fusing time was reproduced. On the other hand, in each of the first, second, and third embodiments according to the present invention, similarly to the conventional example 1 of the two-wire type, between the line short circuit at the end of the cord-like heating wire and the line short circuit at the center. It showed a value with no large variation, demonstrating that high safety was secured.

[Evaluation of melting temperature test]
Looking at the melting temperature of the polymer layer 3 in Table 2 (3b and 3c in Conventional Examples 1 and 2), Examples 1, 2, and 3 are melted on the lower temperature side than Conventional Examples 1 and 2. This is due to the blending of polyamide and elastomer, which induces early line-to-line short-circuiting due to early melting, demonstrating that safety has been improved compared to the prior art.
[Evaluation of the amount of wire biting]
Comparing Table 1 and Table 2, the amount of biting can be obtained by adjusting the extrusion pressure of the insulating coating layer, that is, the extrusion die diameter and the extrusion speed, from the helical winding tension of the strands. The reliability can be fully verified from the results of the bending test.

In the above-described Examples 1, 2, and 3, the heating element wire is spirally wound around the winding core, and the outer periphery of the polymer layer arranged in close contact with the periphery thereof is spaced apart from each other to maintain a constant pitch, and the polymer layer The cord-shaped heating wire has a structure in which the temperature detection element wire and the short-circuit detection element element are spirally wound so as to dig into the wire and an insulating coating layer is formed around the temperature detection element wire. Two conductors composed of a temperature detecting element wire and a short-circuit detecting element element that are spirally wound with a constant pitch and a polymer layer that is press-molded so that the two conductor elements bite, It can also be applied to a heating element wire spirally wound at a predetermined pitch on the outer periphery of the polymer layer that melts at a temperature and a cord-like heating wire provided with a coating layer that insulates the heating element wire.
In this other embodiment, the arrangement positions of the heating element wires, the temperature detection element wires, and the short circuit detection element elements of the first, second, and third embodiments are reversed, and the circuit adopts the configuration shown in FIG. It is.

  As described above, according to the present invention, the temperature detection wires and the short-circuit detection wires each made of a suitable material are alternately arranged on the outer periphery of the polymer layer while being a one-wire cord-like heating wire. Maintaining a constant pitch and spirally wound into the polymer layer and firmly separated and fixed by the upper insulating coating layer, the temperature control circuit provides a highly accurate and stable temperature control function. The line short-circuit protection circuit does not go through high-resistance temperature detection wires at all, and the low resistance value of the short-circuit detection wires provides a highly safe line-to-line short-circuit protection function with little variation. A cord-like heating wire device can be provided.

  It is a cord-shaped heating wire device used for a surface heating device such as an electric blanket or an electric carpet.

DESCRIPTION OF SYMBOLS 1 Winding core 1H Code-like heating wire 2 Heating strand 3 Polymer layer 4 Temperature detection strand 5 Insulation coating layer 6 Short-circuit detection strand

Claims (7)

A heating element wire that is spirally wound around the winding core at a predetermined pitch and applied with alternating current at both ends, a polymer layer that is closely disposed on the heating element wire and melts at a predetermined temperature, and a gap between the outer circumferences of the polymer layer 2 conductors comprising a temperature detection element wire and a short-circuit detection element element spirally wound so as to bite into the polymer layer, and a coating for insulating the two conductors A cord-like heating wire device comprising a layer,
Both ends of the short-circuit detection element wire are connected to one end of a temperature fuse integrated resistor, and the other end of the resistor is connected to both poles of an AC power source via two diodes,
When the heating element wire and the short-circuit detection element are short-circuited at an arbitrary position, the temperature fuse is integrated through a line connected to the short-circuit detection element through a portion where an alternating current applied to the heating element line is short-circuited. A cord-like heating wire device characterized in that a path flowing through the resistor is formed, a current of a magnitude that leads to fusing flows through the path and heats, and a thermal fuse is cut in a short time to ensure safety. Two conductors composed of a temperature detection element wire and a short-circuit detection element element that are spirally wound with a constant pitch provided on the outer periphery of the winding core, and press-molded so that the two conductor elements are bitten. Cord-like heat generation comprising a polymer layer, a heating element wire spirally wound around the outer periphery of the polymer layer that melts at a predetermined temperature, with alternating current applied to both ends, and a coating layer that insulates the heating element wire A wire device,
Both ends of the short-circuit detection element wire are connected to one end of a temperature fuse integrated resistor, and the other end of the resistor is connected to both poles of an AC power source via two diodes,
When the heating element wire and the short-circuit detection element are short-circuited at an arbitrary position, the temperature fuse is integrated through a line connected to the short-circuit detection element through a portion where an alternating current applied to the heating element line is short-circuited. A cord-like heating wire device characterized in that a path flowing through the resistor is formed, a current of a magnitude that leads to fusing flows through the path and heats, and a thermal fuse is cut in a short time to ensure safety. The cord-like heating wire device according to claim 1 or 2,
The cord-like heating wire device, wherein the temperature detection wire and the short-circuit detection wire are each spirally wound so that 10% or more and 50% or less of the thickness or the diameter of the wire is caught in the polymer layer. In the cord-like heating wire device according to claim 1, 2, or 3,
The cord-like heating wire device, wherein the polymer layer is made of a mixture of a polyamide resin and a polyamide-elastomer, and has a melting temperature of 130 ° C or higher and 190 ° C or lower. In the cord-like heating wire device according to claim 1, 2, 3, or 4,
The cord-like heating wire device, wherein the temperature detection wire is a metal wire having a positive temperature coefficient. In the cord-shaped heating wire device according to any one of claims 1 to 5,
The two diodes have the same polarity side connected to one end of a thermal fuse integrated resistor, the other pole side of each of the diodes connected to each pole of an AC power source, and the other end of the temperature fuse integrated resistor A cord-like heating wire device connected to both ends of a short-circuit detection element wire. In the cord-like heating wire device according to any one of claims 1 to 6,
The cord-like heating wire device, wherein the resistance value of the short-circuit detecting element wire is equal to or less than the resistance value of the temperature fuse integrated resistor.

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