JPH0311510B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heating element used in an electric heating appliance.

Conventional technology Conventionally, this type of heating element has been developed, for example, by
It had a configuration as shown in Publication No. 172880. That is, as shown in FIG. 4, a large number of holes are provided in a heating plate 51 made of an insulating material,
were wound at equal pitches through the holes.

Problems to be Solved by the Invention In such a conventional configuration, loosening tends to occur during winding near the part A where the heating wire 52 is wrapped over a long distance, and adjacent heating wires 52 come into contact with each other, resulting in an unexpected failure. It had the disadvantage of not being able to obtain electric power.

In addition, the heating wire 5 generated by normal repeated use
The meandering of No. 2 also appears most strongly near the A section where the winding distance is large and the high temperature section occurs, so the adjacent heating wire 5
The first contact between the heating wires 52 occurs near part A, which leads to an increase in power due to a decrease in total resistance.
It also had the disadvantage of accelerating wire breakage.

The present invention has been made in view of these problems and aims to provide a heating element with improved quality, mass productivity, and excellent durability.

Means for Solving the Problem In order to solve this problem, the present invention has a heat generating plate in which a plurality of winding frames made of an insulating material are formed into a substantially rectangular and annular shape, and a heating wire of the heat generating plate. The winding pitch is set sparsely where the winding distance is long within one winding frame, and densely where the winding distance is short.

Effect With the above configuration, even if the heating wire becomes loose during wrapping in a part where the wrapping distance is long, contact can be prevented because the distance between the heating wire and the adjacent heating wire is large, and the desired power can be obtained. It is something. Furthermore, even if the first meandering occurs in a portion where the winding distance is long during repeated use, since the distance between the heating wires is large, there will be no contact, and early breakage of the heating wires can be prevented.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the accompanying drawings. In FIGS. 1 to 3, 1 is a dish-shaped heat transfer member having a flange 2 on the periphery, 3 is a dish-shaped back member having a flange 4 on the periphery, and a through hole 5 is provided in the center of the bottom. It has a protrusion 6 having a shape. Reference numeral 7 denotes a heating plate made of a pair of paper frames made of an insulating material formed into a substantially rectangular and annular shape, around which a first heating wire 8 and a second heating wire 9 are wound. 10 is an insulating plate that holds the top and bottom of the heat generating plate 7.

The heat transfer member 1 and the back member 3 are integrated by joining their flange portions 2 and 4, as well as the bottom surface of the heat transfer member 1 and the protruding portion 6 of the back member 3, respectively. A space 12 formed around the protrusion 6
A heat-generating plate 7 and insulating plates 10, 10 sandwiching the heat-generating plate 7 are disposed therein, and a first heat-diffusing member 11 made of a metal with good thermal conductivity is closely contacted with the inner surface of the heat transfer member 1 and the upper insulating plate 10, and the heat-generating plate 7 an insulating plate 10 on the lower side of the plate 7;
A second heat diffusion member 13 made of a metal with good thermal conductivity is provided in close contact with the back member 3 and whose peripheral edge is brought into close contact with the heat transfer member 1.

The heating element 7 has a winding pitch larger than that in the B part when comparing the heating wires 8 and 9 in a part A where the winding distance is long and a part B where the winding distance is short.
The heating element is made up of a large section.

In the above configuration, when winding the heating wires 8 and 9 around the heating plate 7, the distance in part A is long, so they tend to loosen a little, and the distance in part B is short, so they are wrapped tightly. Ru.

In addition, when electricity is applied, not only the area near the boundary between part A and part B becomes the hottest part, but also the winding distance is long.
Meandering is more likely to occur in the part A, but since the winding pitch in the A part is larger and the distance between the heating wires is wider, slight loosening and meandering of the heating wires can be absorbed.

As described above, according to this embodiment, even if loosening occurs in the part where the winding distance is long during winding of the heating wire,
Since the winding pitch is large, a sufficient distance between the heating wires can be ensured, and contact between adjacent heating wires can be prevented, so that the desired electric power can be reliably obtained.

Furthermore, since the winding pitch is increased to prevent the heating wires from meandering due to repeated use, the heating wires can be prevented from coming into contact with each other in the same way as described above, and durability can be improved.

Effects of the Invention As is clear from the above description of the embodiments, the present invention makes the winding pitch of the heating wire of the heating plate sparse in the areas where the winding distance is long within one winding frame, and the winding pitch where the winding distance is short. By making the parts dense, it is possible to prevent power failure when wrapping the heating wire, and also to provide a highly durable heating element that can be mass-produced and prevents early disconnection of the heating wire after repeated energization. The effect is great.

[Brief explanation of the drawing]

Fig. 1 is a plan view of essential parts of a heating element showing an embodiment of the present invention, Fig. 2 is a sectional view of the heating element, Fig. 3 is an exploded perspective view of the heating element, and Fig. 4 is a conventional heating element. FIG. 2 is a plan view of the main parts of the body. 7... Heat generating plate, 8... First heating wire, 9... Second heating wire.

Claims (1)

[Claims] 1. A heating plate has a plurality of winding frames made of an insulating material formed into approximately rectangular and annular shapes, and the winding pitch of the heating wire on this heating plate is set so that the winding distance is large within one winding frame. The heating element is loosely wrapped in places and densely wrapped in places where the wrapping distance is short.