JPS6232031Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a flexible electric heating device, such as an electric soft anchor or an electric cushion, in which a heating element is interposed in a so-called flexible cushion material.

The structure of a conventional flexible electric heating device is as shown in FIG.

That is, in this FIG. 3, reference numerals 1 and 1 are flexible cushion materials, and cord type heating wires 3 are arranged in a zigzag pattern on a flexible sheet 2 in the flexible cushion materials 1 and 1. It is composed of Further, in this figure, reference numeral 4 denotes a safety device consisting of a thermostat or a temperature fuse, and this safety device prevents the heating wire 3 from abnormally rising in temperature.

In the case of this conventional structure, heating wires are distributed throughout the heating appliance, so considering its safety, it is necessary to install a large number of safety devices 4 to prevent local abnormal temperature rises. This is not possible and is extremely dangerous. However, since such flexible heating devices are designed to minimize the feeling of a foreign body, the number of safety devices and their placement positions are limited, and usually about two are installed as shown in Figure 3. This is common knowledge, and from a safety standpoint, it can be said to be a very dangerous product.

The purpose of the present invention is to provide a flexible electric heating device that is highly safe, has a uniform temperature on its heating surface, and is comfortable to use. Therefore, a flexible heat diffusion plate that is a good thermal conductor is interlocked with a sheet-like film that is less flexible and a poor thermal conductor, and a concentric waveform is formed on it, and the local part of the heat diffusion plate in the center of the concentric waveform is The heating element is placed in close contact with the heating element.

In this way, safety can be maintained by placing a safety device only near the heating element installed locally on the heat diffusion plate, resulting in an extremely reliable product, and at the same time, heating wires can be placed throughout the heating device. It becomes possible to make the temperature distribution on the heating surface uniform without any heat generation.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Reference numeral 5 denotes a flexible heat diffusion plate which is a good thermal conductor, and is made of, for example, a laminated thin plate of copper or aluminum, or a thin plate formed by braiding a copper foil strip or an aluminum foil strip. A heating element 6 has an area sufficiently smaller than that of the heat diffusion plate 5, and is closely attached to a local part of the heat diffusion plate 5 with a substrate 7 interposed therebetween.

Reference numeral 8 denotes a sheet-like film of a thermally poor conductor that is less flexible than the heat-diffusing plate 5, such as a nylon film or a polypropylene film. A film-free area is provided at the area where the heating element 6 is brought into direct contact with the metal foil.

The sheet-like film 8 is formed with a concentric waveform 9 centered on the non-film portion of the heating element mounting portion. The concentric circular waveform 9 is made smaller in the peripheral portion than in the vicinity of the heating element, and the contact area between the heat diffusion plate 5 and the sheet film 8 is made smaller in the vicinity of the heating element to reduce heat radiation. The contact area at the periphery is increased to increase heat dissipation. An appropriate combination of waveform sizes is selected to make the temperature distribution on the heating surface uniform.

In addition, the sheet-like film 8 is made of a material that is less flexible than the heat diffusion plate 5, and the fatigue of the heat diffusion plate 5 is reduced by increasing the bending radius of the heat diffusion plate 5 when bending force is applied to the sheet film 8. This also prevents permanent bending from remaining. Although it is desirable for the sheet-like film 8 to have less flexibility in order to reduce fatigue of the heat diffusion plate 5, it is hard and undesirable as a flexible heating device. In this case, the waveform is large near the heating element where the bending stress is greatest and there is little flexibility, and as you get closer to the periphery, the waveform becomes smaller and the flexibility increases, which is preferable for reducing fatigue and for use. becomes. Reference numeral 4 designates a safety device such as a thermostat or temperature fuse provided on the substrate 7 near the heating element 6, and 10 represents a cover that covers the heating element 6 and the safety device 4. 1
Reference numeral 1 designates a power cord for energizing the heating element 6, which is pulled out from a bent portion at one end of the board 7 via a cord armer 12. By being interposed between the flexible cushion materials 1, 1, they constitute a flexible electric heating device. Note that 13 in the figure is a front cover.

The present invention has the above-mentioned configuration, and when the heating element is energized, the heating element generates heat, and the heat is diffused by the heat diffusion plate. The temperature of a heat diffusion plate is high near the heating element, and tends to decrease as it gets closer to the periphery of the heat diffusion plate. As the circularly shaped corrugations get closer to the periphery of the heat diffusion plate, the contact area of the heat diffusion plate becomes larger and the area becomes smaller. The amount of heat reaching the heating surface becomes uniform, and the temperature of the heating surface becomes uniform. This results in a flexible electric heating device that feels as if a heating element is placed all over it.

According to the present invention, the heating element is placed in a very small part of the heat diffusion plate, and the safety device is also placed in a very small part, so there is no feeling of a foreign body, and even if the heating element becomes abnormally heated. Since a safety device is placed near it, the safety device operates reliably, resulting in a flexible electric heating device that is extremely safe and easy to use. Furthermore, according to the present invention, unlike conventional heating devices, the heating wire is not distributed throughout the heating device, so there is no problem of wire breakage due to bending.

[Brief explanation of the drawing]

1 and 2 are partially cutaway perspective views and main part sectional views of a flexible electric heating device according to an embodiment of the present invention, and FIG. 3 is a partially cutaway view of a conventional flexible electric heating device. It is a cutaway perspective view. 1... Flexible cushion material, 5... Heat diffusion plate,
6... Heating element, 8... Sheet film, 9...
Waveform.

Claims (1)

[Scope of utility model registration request] A heat diffusion plate 5 made of a flexible heat conductor is interposed with a sheet-like film 8 made of a less flexible heat conductor, and a heating element 6 is brought into close contact with a local part of the heat spreader plate 5. A concentric waveform 9 is formed on the film 8 around the heating element 6, and the waveform 9 is formed into the flexible cushion material 1 in such a manner that the waveform 9 is smaller in the peripheral area than in the vicinity of the heating element 6. A flexible electric heating device constructed with an intervening structure.