JPH05159863A - Antifreezer - Google Patents

Abstract

PURPOSE:To prevent a heater wire from overheating by detecting that temperature in a heater element becomes abnormally high without a moment's delay. CONSTITUTION:A trouble detecting wire K1 is installed in parallel with a heater wire H. This trouble detecting wire K1 is formed into a structure provided with each electrode 4 at both inner and outer sides of nylon resin 5. When this trouble detecting wire K1 has come to a temperature more than a fusing point of the nylon resin 5, an interval between these electrodes 4 being opposed to each other via the nylon resin 5 is short-circuited at this nylon resin is fused. In the case where the nylon resin 5 lying between these electrodes 4 of the trouble detecting wire K1 fused by abnormal heating of the heating wire H, the electrodes 4 are short-circuited and thereby an electric current flows into a resistor R1. Therefore, voltage is produced in a gate terminal, a thyristor Q1 is conducted, and a temperature fuse H1 is melted. Accordingly, current- energization to the heater wire H is thus stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to an antifreezing device used for water pipes and the like.

[0002]

2. Description of the Related Art Conventionally, a pair of electrodes are arranged to face each other.
A material with a large positive temperature coefficient of resistance between the electrodes (hereinafter,
A self-temperature control type antifreezing device using a heating wire configured by sandwiching PTC material) is commercially available.
In this heating wire, a uniform heat is generated due to the current flowing between the pair of electrodes through the PTC material. However, when a locally adiabatic portion occurs, the temperature of that portion rises and the resistance of the PTC material increases, so the amount of heat output from that portion decreases.

That is, it is possible to automatically control the local temperature of the heat insulating portion of the heating wire by using the heating wire as described above.

[0004]

However, in such a heating wire, the temperature resistance characteristic of the PTC material, which is a factor that determines the control temperature, is relatively unstable, and other heat insulating wires cause other heat insulation. When the PTC material is exposed to a temperature higher than that for a long time, the temperature resistance characteristic of the PTC material changes with time, and the self-control temperature determined by the balance between the amount of heat generated by the current flowing through the PTC material and the amount of heat released from that portion It will change. In particular, when the change in the temperature resistance characteristic of the PTC material is a change in the direction of decreasing the resistance value, the self-control temperature becomes high, which is dangerous.

That is, the self-control temperature of the heating wire is PT
Since it is controlled by the temperature resistance characteristic of C material,
If the temperature resistance characteristic of the PTC material changes due to the temperature of local heat insulation for a long time, the self-control temperature will change. Further, conventionally, since there is no means for detecting the change in the temperature resistance value characteristic of the PTC material, there is a problem that it is dangerous if the temperature resistance value characteristic of the PTC material changes in the direction of increasing the self-control temperature. was there.

The present invention has been provided in view of the above-mentioned points, in which the heating wire and the abnormality detection wire are integrally molded to quickly detect an abnormally high temperature of the heating element and to overheat the heating wire. The present invention provides a freezing prevention device for the purpose of preventing this.

[0007]

According to the present invention, at least two or more electrodes are arranged to face each other in a freeze prevention device for preventing freezing of a certain object by heat generated by passing an electric current. A heating wire formed by sandwiching a material having a positive temperature coefficient of resistance between electrodes and an abnormality detection line in which a pair of electrodes are opposed to each other with a low melting point resin layer formed integrally, and the pair of electrodes of the abnormality detection line are An abnormality detection circuit is provided for detecting a short circuit and stopping the power supply to the heating wire.

In the second aspect, the abnormality detection line is composed of a single strip of an electrode made of a low melting point metal, and the fact that the electrode is melted is detected.

[0009]

When the heating wire abnormally heats up, the abnormality detection line is short-circuited to detect it by the abnormality detection circuit, and the power supply to the heating wire is stopped to prevent abnormal heating of the heating wire. Can be prevented. In addition, by configuring the abnormality detection line with a single electrode made of a low melting point metal, when the heating wire abnormally generates heat, the abnormality detection line is melted and detected by the abnormality detection circuit, It is possible to prevent abnormal heat generation of the heat generation line by stopping the energization of, and the structure of the abnormality detection line is simplified by configuring the abnormality detection line with one electrode made of low melting point metal. In addition, since the abnormality detection circuit operates even if an intermittent failure occurs due to an error in the structure of the abnormality detection line or an error in use, reliability and safety can be further improved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows a heating wire corresponding to claim 1.
That is, the schematic configuration of the integrated heating wire W ₁ obtained by integrally molding the heating wire H and the abnormality detection wire K ₁ is shown. In FIG. 4, the heating wire H has a structure in which the space between two opposing electrodes 1 is filled with the PTC material 2. When a constant voltage is applied between these electrodes 1, a current flows through the PTC material 2,
It produces a fever. Due to this heat generation, the temperature of the PTC material 2 rises, the resistance value of the PTC material 2 gradually increases, and conversely the current decreases. Eventually, PTC material 2
It stabilizes at a temperature where the amount of heat generated and the amount of heat released are the same.

An abnormality detection line K ₁ is provided in parallel with the heating line H. The abnormality detection line K ₁ has _one of the electrodes 4 formed in a spiral shape on the middle thread 3, a nylon resin 5 is formed on the outside thereof, and the other side of the electrode 4 is spirally formed on the nylon resin 5 formed in a cylindrical shape. It has a structure formed into a shape. And these abnormality detection lines K ₁ are made of nylon resin 5
When the temperature is equal to or higher than the melting point of Nylon resin 5, the nylon resin 5 is melted, and the electrodes 4 facing each other via the nylon resin 5 are short-circuited. The heating line H and the abnormality detection line K
Reference numeral ₁ is an insulating resin 6 which is integrally molded.

FIG. 5 shows a heating wire corresponding to claim 2. That is, the schematic configuration of the integrated heating wire W _{2 in which} the heating wire H and the abnormality detection wire K ₂ are integrally molded is shown. In FIG. 5, an abnormality detection line K ₂ composed of a low melting point metal electrode 7 is provided in parallel with the heating line H, and the temperature of these abnormality detection lines K ₂ exceeds the melting point of the low melting point metal electrode 7 and rises in temperature. Would melt the low melting point metal electrode 7. The heat generation line H and the abnormality detection line K ₂ are integrally molded with the insulating resin 6.

FIG. 6 shows the temperature resistance value characteristic of the heating wire H.
Here, the initial characteristic before the heating line H is subjected to the thermal history is T ₁
The temperature resistance value characteristic of the heating wire H when the resistance value changes in the direction of decreasing resistance value at the same temperature due to the heat history is shown by T ₂ . At this time, the change in the temperature resistance value characteristic when the heating wire H receives a heat history may change in the direction in which the resistance value increases at the same temperature, but in such a case, the heating wire H It is safe because the temperature of H tends to decrease.

However, as shown in FIG. 6, when the temperature resistance value characteristic of the heating wire H changes in the direction of decreasing resistance value at the same temperature, the temperature of the heating wire H changes in the direction of increasing temperature. Therefore, it is dangerous. FIG. 1 shows a circuit diagram corresponding to claim 1. One end of the pair of electrodes 1 of the heating wire H is connected to one end of the commercial power supply AC via the temperature fuse FH _1, and the other end of the electrode 1 is directly connected to the other end of the commercial power supply AC. A commercial voltage is uniformly applied to the PTC material 2 between the electrodes 1 so that uniform heat generation can be obtained.

An abnormality detecting circuit for detecting an abnormality of the abnormality detecting line K ₁ is constructed as follows. That is,
A series circuit of a diode D ₁ , a heat generating resistor RH ₁ and a thyristor Q ₁ is connected between both ends of the electrode 1 of the heat generating line H, and when the thyristor Q ₁ becomes conductive, the heat generating resistor RH
_A large current flows into ₁ and heats up. Since the heating resistor RH ₁ and thermal fuse FH ₁ are thermally coupled, the temperature fuse FH ₁ is blown by the heat generation of the heat generating resistor RH _1, and so as to stop the power supply to the heating cable H.

Further, between the both ends of the electrode 1 of the heating wire H, the diode D ₂ , the resistance R ₂ , the interelectrode of the electrode 4 of the abnormality detection wire K ₁ and the resistance R ₁ are connected in series. A capacitor C ₂ is connected in parallel with the resistor R _1, and the terminal of the resistor R ₁ on the side connected to the electrode 4 is connected to the gate terminal of the thyristor Q ₂ . When the nylon resin 5 between the electrodes 4 of the abnormality detection line K ₁ is melted due to the abnormal heat generation of the heating line H, the electrodes 4 are short-circuited and a current flows through the resistor R ₁ to generate a voltage between both terminals, which causes a thyristor. Q ₁ becomes conductive and the thermal fuse FH ₁ is blown. Therefore, the power supply to the heating wire H is stopped.

Although nylon resin 5 is used as the low melting point resin layer, this nylon resin 5 is 12 nylon and has a melting point of about 180.degree. In addition, PTC material 2
Formed by kneading carbon black with a thermoplastic resin,
It has flexibility. (Embodiment 2) FIG. 2 shows another embodiment of the antifreezing device according to claim 1. In the embodiment shown in FIG. 1, when the electrode 4 of the abnormality detection line K ₁ is broken for some reason, There was a problem that the abnormality detection function does not work, but this problem is solved in this embodiment.

As shown in FIG. 2, the end of the electrode 1a at one end of the heating wire H is connected to the commercial power source A through a thermal fuse FH _3.
C is connected to one end, and the other electrode 1b is directly connected to the commercial power source A
It is connected to the other end of C (also serving as the common circuit ground COM), and a commercial voltage is uniformly applied to the PTC material 2 between the pair of electrodes 1 so that uniform heat generation can be obtained.

Further, between the secondary-side terminal and the shared circuit ground COM temperature fuse FH _3, the diode D _5, the heat-generating resistor RH _3, with the series circuit of the thyristor Q ₃ is not connected, the thyristor Q ₃ Is conducted, the heating resistor RH
₃ generates heat, the temperature fuse FH ₃ which are thermally coupled
I try to melt it. Furthermore, the temperature fuse FH ₃
A diode D ₆ and a resistor R ₅ are connected in series to the secondary side terminal of the. Between the resistor R ₅ and the common circuit ground COM, resistors R ₆ and R ₇ connected in series and an abnormality detection line K are connected.
₁ electrode 4a, resistance R ₈ , electrode 4b, current fuse CF
Are respectively provided in series.

If the connection point between the resistors R ₆ and R ₇ is point G,
The gate terminal of the thyristor Q ₃ is connected to the G point, and the capacitor C for smoothing the half-wave voltage between the G point and the common circuit ground COM into a direct current is connected between the G point and the common circuit ground COM. ₃ are provided. When there is no abnormality in the abnormality detection line K ₁ , the current half-wave rectified by the diode D ₆ flows through the resistor R ₅ , the electrode 4a, the resistor R ₈ , the electrode 4b, and the current fuse CF. Since the electrodes 4a, the resistance value of the 4b is sufficiently small, the current value of the path, the resistance R _5, R ₈
Is determined by the resistance value of. The resistance R ₈ is made sufficiently large so that the above current value is smaller than the fusing rated current value of the current fuse CF.

The temperature of the abnormality detection line K ₁ becomes abnormally high,
When the nylon resin 5 is melted, the electrodes 4a and 4b are short-circuited, and the current exceeds the fusing rated current value of the current fuse CF, and a current flows, and the current fuse CF is blown.
When the current fuse CF is blown, no current flows in the abnormality detection line K _1, and the current half-wave rectified by the diode D ₆ flows only in the resistors R ₅ , R ₆ , and R ₇ . Therefore, the amount of current flowing through the resistor R ₇ changes before and after the current fuse CF is blown, and the voltage at the point G becomes high after the current fuse CF is blown.

When the current fuse CF is not blown by adjusting the resistance values of the resistors R ₆ and R ₇ , the voltage at the point G is made lower than the conduction gate voltage of the thyristor Q ₃ to blow the current fuse CF. and when the, so the voltage at the point G is set to be higher than the conduction gate voltage of the thyristor Q _3, when the current fuse CF is blown operates thyristor Q _3, and the temperature fuse FH ₃ melted, heating The power supply to the line H is stopped.

Further, even if the electrodes 4a and 4b of the abnormality detection line K ₁ are broken for some reason, the temperature fuse FH ₃ is melted by the same operation as described above, and the power supply to the heating line H is stopped. It will be. (Embodiment 3) FIG. 3 shows a circuit diagram corresponding to claim 2. One end of the pair of electrodes 1 of the heating wire H is connected to one end of the commercial power supply AC via the thermal fuse FH _2, and the other end of the electrode 1 is directly connected to the other end of the commercial power supply AC. The commercial voltage is evenly applied to the PTC material 2 between the electrodes 1 so that uniform heat generation can be obtained.

Further, a series circuit of a diode D ₃ , a heating resistor RH ₂ and a thyristor Q ₂ is connected between both ends of the electrode 1 of the heating wire H, and when the thyristor Q ₂ becomes conductive, the heating resistor RH ₂ A large current flows into the heat source to generate heat. Since the heating resistor RH ₂ and the temperature fuse FH ₂ are thermally coupled, the temperature fuse FH ₂ is blown by the heat generation of the heat generating resistor RH _2, and so as to stop the energization of the heating wire H.

Further, a diode D ₄ and resistors R ₄ and R ₃ are connected in series between both ends of the electrode 1 of the heating wire H. Resistor R ₃ and capacitor C ₂ and the low melting point metal electrodes 7 are provided in parallel, the connection point of the resistors R ₃ and R ₄ are connected to the gate terminal of the thyristor Q _2. The low-melting point metal electrode 7 is, for example, a Sn-Pb-Bi-based thin wire of low-melting point alloy solder having a melting point of 140 ° C.

If the heating wire H is normally generating heat,
Irista Q₂The low-melting metal electrode 7 is used for the cathode and gate terminal of
Thyristor Q because it is short-circuited₂Does not conduct. Low
The melting point metal electrode 7 is blown by the abnormal heat generation of the heating wire H.
If Thyristor Q₂Voltage between the cathode and the gate terminal of
Occurs, thyristor Q₂Is conducted, and the thermal fuse FH ₂
Is melted and the power supply to the heating wire H is stopped.

The circuit of the present embodiment can detect abnormal heat generation of the heating wire H and stop the power supply to the heating wire H with a simpler configuration than that of FIG.

[0028]

As described above, according to the present invention, at least two or more electrodes are arranged opposite to each other in a freeze prevention device in which a certain object is prevented from freezing by the heat generated by passing an electric current. A heating wire formed by sandwiching a material having a positive temperature coefficient of resistance between electrodes and an abnormality detection line in which a pair of electrodes are opposed to each other with a low melting point resin layer formed integrally, and the pair of electrodes of the abnormality detection line are Since it is equipped with an abnormality detection circuit that detects the occurrence of a short circuit and stops the energization of the heating wire,
When the heat generation line abnormally heats up, the abnormality detection line is short-circuited and the abnormality detection circuit detects this, and by stopping the power supply to the heat generation line, it is possible to prevent abnormal heat generation of the heat generation line. It plays.

According to the second aspect of the present invention, the abnormality detection line is composed of a single strip of an electrode made of a low melting point metal, and the fact that the electrode is melted is detected. When the abnormality detection line is blown, the abnormality detection circuit detects it, and by stopping the power supply to the heating line, abnormal heating of the heating line can be prevented. Since the electrode is made of a low melting point metal, the structure of the abnormality detection line can be simplified, and
Even if an intermittent failure occurs due to an error in the structure of the anomaly detection line or an error in usage, the anomaly detection circuit operates, so that reliability and safety can be further improved.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention.

FIG. 2 is a circuit diagram of Embodiment 2 of the above.

FIG. 3 is a circuit diagram of Embodiment 3 of the above.

FIG. 4 is a perspective view of an essential part of the integrated heating wire of the above.

FIG. 5 is a perspective view of an essential part of the integrated heating wire of the above.

FIG. 6 is a characteristic diagram showing the relationship between the temperature and the resistance value of the heating wire of the above.

[Explanation of symbols]

1 Electrode 2 PTC material 4 Electrode 5 Nylon resin 6 Insulating resin H Heating wire K ₁ Abnormality detection wire W ₁ Integrated heating wire

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 3, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

[Action] by Thus, when the heating wire is abnormally exothermic, with detects this abnormal detection circuit that abnormality detection line is short-circuited, the power supply to the heating wire by stopping the abnormal heat generation of the heating wire Can be prevented. Further, by constituting the electrode comprising an abnormality detection line from a strip of low-melting-point metal, when the heating wire is abnormally exothermic, with the abnormality detection line detects this abnormal detection circuit to blow, to the heating wire It is possible to prevent abnormal heat generation of the heat generation line by stopping the energization of, and the structure of the abnormality detection line is simplified by configuring the abnormality detection line with one electrode made of low melting point metal. reduction can, and, errors or structural abnormality detection line, even when the failure sectional line by misuse, abnormal since the detection circuit to operate, it is possible to further improve reliability, safety.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

[0011] The heating wire abnormality detection line K ₁ to H and parallel lines are provided. The abnormality detection line K ₁ has _one of the electrodes 4 formed in a spiral shape on the middle thread 3, a nylon resin 5 is formed on the outside thereof, and the other side of the electrode 4 is spirally formed on the nylon resin 5 formed in a cylindrical shape. It has a structure formed into a shape. And these abnormality detection lines K ₁ are made of nylon resin 5
When the temperature is equal to or higher than the melting point of Nylon resin 5, the nylon resin 5 is melted, and the electrodes 4 facing each other via the nylon resin 5 are short-circuited. The heating line H and the abnormality detection line K
Reference numeral ₁ is an insulating resin 6 which is integrally molded.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

FIG. 5 shows a heating wire corresponding to claim 2. That is, the schematic configuration of the integrated heating wire W _{2 in which} the heating wire H and the abnormality detection wire K ₂ are integrally molded is shown. 5, the abnormality detecting wire K ₂ made of a low-melting metal electrode 7 is provided on the heating wire H and concurrency, these abnormality detection line K ₂ is then heated beyond the melting point of the low melting metal electrode 7 In this case, the low melting point metal electrode 7 will be blown. The heat generation line H and the abnormality detection line K ₂ are integrally molded with the insulating resin 6.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

[0028]

As described above, according to the present invention, at least two or more electrodes are arranged opposite to each other in a freeze prevention device in which a certain object is prevented from freezing by the heat generated by passing an electric current. A heating wire formed by sandwiching a material having a positive temperature coefficient of resistance between electrodes and an abnormality detection line in which a pair of electrodes are opposed to each other with a low melting point resin layer formed integrally, and the pair of electrodes of the abnormality detection line are Since it is equipped with an abnormality detection circuit that detects the occurrence of a short circuit and stops the energization of the heating wire,
If the heating wire abnormally heats up, the abnormality detection wire will be short-circuited.
Together it detects this in abnormality detection circuit, the power supply to the heating wire by stopping, in which is provided an advantage of being able to prevent abnormal heat generation of the heating wire.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

According to the second aspect of the present invention, the abnormality detection line is composed of a single strip of an electrode made of a low melting point metal, and the fact that the electrode is melted is detected. with abnormality detection line detects the Re this <br/> abnormal detection circuit to fusing, the energization of the heating wire by stopping, it is possible to prevent abnormal heat generation of the heating wire, also, the abnormality detection Since the wire is composed of one electrode made of a low melting point metal, the structure of the abnormality detection wire can be simplified, and
The error detection line may be broken due to a structural error or an error in use.
Even if a line failure occurs, the abnormality detection circuit operates, so that reliability and safety can be further improved.

Claims (2)

[Claims] 1. In a freeze prevention device configured to prevent freezing of a certain object by heat generated by passing an electric current, at least two or more electrodes are arranged to face each other, and a positive temperature coefficient of resistance is provided between the electrodes. A heating wire that sandwiches the material of
An anomaly detection circuit that integrally forms a pair of electrodes with an anomaly detection line facing each other via a low melting point resin layer, and detects that a pair of electrodes of the anomaly detection line is short-circuited and stops energizing the heating line An anti-freezing device characterized by being provided with. 2. The antifreezing device according to claim 1, wherein the abnormality detection line is composed of a single strip of an electrode made of a low-melting metal and is adapted to detect that the electrode has melted.