JPH0935851A - Belt-shaped heating unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt-shaped heating unit with no hazardousness due to short-circuiting, by forming into structure of integrally arranging an earth member in addition to a heating wire, so as to quickly perform detecting leakage with regard to a short-circuit phenomenon of the heating wire. SOLUTION: This belt-shaped heating unit comprises a heating wire 2 wound to a core wire 1, first insulating member 11 of coating this heating wire 2, earth member 12 arranged on the first insulating member 11 and a second insulating member 3 of arranging parallelly to each other a wire material of including the heating wire 2, first insulating member 11 and the earth member 12 to be coated into a belt shape. The earth member 12 may be a braided wire of stranding a metal wire rod and metal foil or a thin metal wire rod.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip-shaped heating element used to prevent freezing of a liquid passing through a pipe body, and more particularly, to a strip-shaped heating body wound around a water pipe or along the pipe to prevent water in the water pipe from freezing. Regarding heating element.

[0002]

2. Description of the Related Art As shown in FIGS. 8 and 9, a conventional strip-shaped heating element has a heating wire 32 spirally wound around a single flexible core wire 31 such as a glass core wire, and these are wound in a U-shape. The strip-shaped heating element 34 is formed by bending the strips and arranging the strips in parallel with each other and covering them with a flexible covering member 33 such as rubber or resin.

As shown in FIG. 9, a power cord 35 is connected to both ends of the heating wire 32. Further, as shown in FIG. 10, a thermostat 36 is interposed in the middle portion of one heating wire 32. The thermostat 36 serves to keep the heating element 34 at a constant temperature. That is, the thermostat 36 is a temperature controller for adjusting the temperature of the heating element 34.

[0004]

However, in the strip-shaped heating element, rainwater and the like enter the heating wire 32 when a nail is struck on the covering member 33 or a part of the covering member 33 is cut by a knife. There is a risk of short-circuiting. Therefore, if there is a short circuit,
Since the thermostat 36 merely measures the temperature of a part of the heating element, there is a problem that the leakage cannot be detected.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a belt-shaped heating element capable of promptly detecting an electric leakage with respect to a short-circuit phenomenon of a heating wire and having no danger due to a short circuit.

[0006]

According to the present invention, a heating wire, a first insulating member covering the heating wire, a grounding member arranged on the first insulating member, the heating wire, The first
A strip-shaped heating element is provided, which comprises: a second insulating member in which the insulating member and the wire including the ground member are arranged in parallel with each other and covered in a strip shape.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the strip heating element of the present invention. 2 to 4 show the detailed structure of each part of the strip-shaped heating element shown in FIG.

First, referring to FIG. 1 and FIG. 2, the strip-shaped heating element comprises a heating wire 2 wound around a core wire 1, a first insulating member 11 covering the heating wire 2, and a first insulating member. The grounding member 12 is provided on the upper surface 11 of the heating element 11, and the second insulating member 3 is formed by arranging the heating wire 2, the first insulating member 11, and the filament including the grounding member 12 in parallel with each other and covering them in a strip shape.

The strip-shaped heating element is formed by spirally winding a heating wire 2 around one flexible core wire 1 such as a glass core wire.
The outer periphery of the heating wire 2 is covered with the first insulating member 11,
A ground wire (ground member 12) is arranged on the outer periphery of the insulating member 11 and is further arranged in parallel by bending them into a U-shape, and the second covering member 3 having flexibility such as rubber or resin. The band-shaped heating element 4 is formed by covering with.

A power cord 5 is connected to each of both ends of the heating wire 2, as shown in FIG. A ground cord 14 is connected to each of both ends of the ground wire 12. In addition, in the middle portion of one heating wire 2,
As also shown, the thermostat 6 is interposed.
The thermostat 6 serves as a safety device when the heating element 4 abnormally heats. The thermostat 6
The ground wires 12 arranged on the outer circumference of the heat generating wire 2 with the interposition of are connected to each other and covered with the tube 15a.

The middle portion of the other heating wire 2 is the heating wire 2,
Each of the ground wires 12 is connected to each other to form the tube 1
It is covered by 5b.

The heating wire 2 is made of a metal wire rod or a metal strip foil, and the ground wire 12 is a braided wire 16 in which a metal wire rod, a metal strip foil or a thin metal wire rod is woven as shown in FIG. Good. In addition, the heating element 4 and the ground wire 12
Each of the connection portion with the power cord 5, the intermediate connection portion of the heating element 4, and the U-shaped portion can be prevented from entering water from the outside by molding, that is, have a waterproof structure. You can

FIG. 6 shows a circuit of the strip-shaped heating element shown in FIG. The operation of the strip-shaped heating element will be described with reference to FIG. 6. The heating element 4 is fixed to the water pipe by being wound around or wound around a water pipe (not shown). In this way, when the power cord 5 is connected to the commercial power source, the ground terminal shown in FIG. 7 is also grounded. FIG.
A plug with a ground terminal is shown in which a plug 17 of the power cord 5 is provided with a ground terminal 18 connected to the ground wire 14.

Since the heating element 4 is heated, freezing is prevented by keeping the water frozen inside the water pipe at a temperature exceeding 0.degree. At this time, thermostat 6
Detects ambient temperature and turns the power on and off.

Furthermore, when a phenomenon occurs in which the heating wire 4 and the ground wire 12 are short-circuited, the resistance of the heating wire 2 changes, and this resistance change is detected by an earth leakage detector (not shown), which causes electric leakage. Avoid danger.

[0016]

As described above, according to the strip-shaped heating element of the present invention, since the earth member is integrally arranged in addition to the heating wire as described in the embodiments, the construction which occurs by nailing, cutting with a knife, etc. The leakage phenomenon due to a mistake can be easily found.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a strip-shaped heating element of the present invention.

FIG. 2 is a perspective view showing an arrangement state of a heating wire and a ground wire of the heating element of FIG.

FIG. 3 is a plan view showing a connection configuration of a heating wire, a ground wire, and a power cord of FIG.

FIG. 4 is a plan view showing a connection configuration of an intermediate portion of the heating wire and the ground wire of FIG.

5 is a perspective view showing an arrangement state of a heating wire and a ground wire of the heating element of FIG.

FIG. 6 is a circuit diagram showing a circuit configuration of the strip-shaped heating element shown in FIG.

FIG. 7 is a plan view showing a specific example of a plug with a ground terminal used in the strip-shaped heating element of FIG.

FIG. 8 is a plan view showing a conventional band-shaped heating element.

9 is a perspective view showing an arrangement state of heating lines of the heating element of FIG.

FIG. 10 is a plan view showing a connection configuration of the heating wire and the power cord of FIG.

FIG. 11 is a plan view showing a connection configuration of an intermediate portion of the heating wire of FIG.

[Explanation of symbols]

 1,31 Core wire 2,32 Heating wire 3 Second insulating member 4,34 Heating element 5,35 Power cord 6,36 Thermostat 11 First insulating member 12 Ground wire 14 Ground cord 17 Power plug 18 Ground terminal

Claims (5)

[Claims] 1. A heating wire, a first insulating member covering the heating wire, and a grounding member arranged on the first insulating member.
A strip-shaped heating element, comprising: a heating wire, a second insulating member in which filaments including the first insulating member and the grounding member are arranged in parallel with each other and covered in a strip shape. 2. The belt-shaped heating element according to claim 1, wherein a power cord is connected to the heating wire and an earth cord is connected to the grounding member. 3. The strip heating element according to claim 1, wherein the grounding member is a strip-shaped metal body, and the metal body is spirally wound around the first insulating member. Band heating element. 4. The band-shaped heating element according to claim 1, wherein the ground member is a braided wire in which a metal wire is woven. 5. A belt-shaped heating element, characterized in that a power supply connection plug connected to the power supply cord is provided with a ground terminal connected to the ground member.