JPH0451485A - Sheet form heat emitting element - Google Patents

Abstract

PURPOSE:To accomplish simple installation and provide possibility of attaining high temp. in a short time by consolidating a band-shaped heat emitting element of metal, with a plurality of projections provided having hole or notch on the same plane, with a supporting device for this band-shaped heat emitting element using a coupling device. CONSTITUTION:A plurality of projections 3 are provided on a band-shaped heat emitting element 2 made of metal and are used for fixation of the band- shaped element 2. The projections 3 must not necessarily be located on a single sode of this band-shaped element, but may be located on both sides, and the shape must not necessarily be rectangular but may be semi-circular or triangular. A coupling device 5 is inserted in a hole 6 provided in the heat emitting element 2 and pinched by a supporting device 4, and thereby the element 2 is fixed. The supporting device 4 is made of a heat resistant inorganic material such as glass or ceramic. The coupling device 5 is made of stainless steel having heat resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high-temperature planar heating element having a heating element temperature of 700'C or more, for example, for use in cooking appliances, heaters, etc. used in ordinary homes.

Conventional technology Conventional high-temperature planar heating elements have a structure in which a heating wire is wound around an insulating substrate such as mica and sandwiched between upper and lower mica plates, or a heating wire of a predetermined shape is placed in a block made of alumina and wrinkle-resistant fibers. It was a buried structure.

Problems to be Solved by the Invention However, the conventional technology has had the following problems.

That is, when mica is used as a heating element, the heating wire is embedded in mica, so in order to obtain high-temperature radiation, it is necessary to raise the temperature of the surface of the mica plate. For this reason, it is necessary to increase the temperature of the heating wire. As such high-temperature heating elements, nickel-chromium heating wires and iron-chromium heating wires are used in general household appliances. Among these, the iron black J4 heating wire has a lifespan of about 1000 hours at 1200°C, but in the case of mica heating elements, if the contact between the mica and the heating wire deteriorates, heat conduction decreases and that part becomes high temperature. The heating wire is more likely to be fused. Therefore, in practical terms, the line temperature is designed to be 1000 to 1100°C. At this time, the surface temperature of the mica plate is 500 to 600°
It can only be C. Therefore, as a device, it is 500 to 6
Since radiation from a heat source of 00'C is used, it is difficult to utilize radiation from a heat source of 700 to 800C, which is advantageous for cooking or heating. In addition, radiation is not obtained directly from the heating wire, but from a mica plate or a steel plate provided for mechanical reinforcement, so it takes time for these radiant surfaces to heat up. was not obtained. The same thing happened with the nickel-chromium heating wire.

In addition, in the case of a heating element in which a part of the heating wire is embedded in a block made of alumina/silica fiber, etc., the mechanical strength of the block is low, and a sudden temperature difference occurs between the heating element and the block when energized. In some cases, cracks appeared in the block, making it difficult to hold the heating wire. Also, if the thickness is increased to increase mechanical strength, the heat capacity increases,
Since a considerable part of the heating wire is buried in the block, the heat is taken away by the block and the temperature of the heating wire is raised to a high temperature, e.g.
It took a considerable amount of time to reach °C.

In order to solve the above problem, a method can be considered in which a heating element, for example, an iron-chromium steel plate is fixed as a punched plate-shaped heating element in a serpentine shape, and the object to be heated is heated by direct radiation from this heating element. However, in order to obtain a high temperature of 700 to 800°C in a short time, it is necessary to prevent the heat from the heating element from being taken away by thermal conduction, and it is necessary to easily fix the heating element industrially. .

However, a method that satisfies these requirements has not yet been found.

The present invention solves the above problems, and aims to provide a structure that is easy to install and can reach a high temperature in a short time.

Means for Solving the Problems The present invention provides various configurations described below in order to solve the above problems. That is, (1) a configuration in which a band-shaped metal heating element in which a plurality of convex portions having holes or notches are planted in the same plane and a support device that supports the band-shaped metal heating element are connected and integrated by a coupling device.

(2) A configuration in which a band-shaped metal heating element is provided with a plurality of convex portions on the same plane and the convex portions are bent, and is supported and fixed by a support device.

(3) A belt-shaped metal heating element in which a plurality of convex portions having holes or notches are planted in the same plane and the convex portions are bent is supported and fixed by a support device.

action The present invention can solve the problems with the above configuration.

According to the present invention, a convex portion is provided on a part of the metal heating element, and the convex portion is in contact with the support device via the support device or the coupling device. This contact has a small contact area. Furthermore, since the convex portion has a higher resistance than other parts (it becomes higher toward the tip of the convex portion), it is difficult for current to flow and the amount of heat generated is small.

In particular, it is dominated by heat transfer rather than temperature generation at the tip of the convex portion.

Therefore, the temperature at the tip of the convex portion can be reduced to 600°C or less, for example, compared to the design temperature of 800°C. As described above, since the heat transfer loss of the heating element is small, the heating element can easily reach a high temperature in a short time. Further, by providing holes or notches in the convex portion, the band-shaped heating element can be easily fixed by inserting a support device such as a rod-shaped body.

Embodiments Embodiment 1 Hereinafter, an embodiment of the present invention will be described based on the accompanying drawings. In FIG. 1, a sheet heating element 1 is a band-shaped metal heating element 2.
, a support device 4 and a coupling device 5. Further, convex portions 3 are provided at a plurality of locations on the band-shaped metal heating element 2.

The band-shaped metal heating element 2 can be obtained by punching an iron-chromium-aluminum-based, stainless-steel-based, or nickel-chromium-based heating element with a press in a serpentine shape, or by bending a metal band into a planar shape. Further, the heating element may be used as it is, or may be used with an inorganic coating provided thereon in order to improve corrosion resistance or radiation efficiency.

A feature of the present invention is that the band-shaped metal heating element 2 is provided with convex portions 3 at a plurality of locations as shown in FIG. 2(a). Since the protrusions 3 are used to fix the band-shaped metal heating element 2, their shape and number are not particularly limited as long as they suit the purpose.

However, as shown in FIG. 2, the convex portion 3 does not need to be on one side of the band-shaped body, it may be on both sides, and the shape may not be rectangular but semicircular or triangular. . Second
Figure (b) is an enlarged view of the convex portion 3 in figure (a). Does the current flow in Fig. 2(b)? *B (]) (2)
Considering (3), for the same potential difference ■, (1)
The flow path becomes longer in the order of →(2) →(3). Since the composition of this part is the same, the resistance increases in the order of (1)→(2)→(3). Therefore, this means that the current flowing in the above order is smaller, and the amount of heat generated is smaller.

That is, even if the temperature is 800'C in the flow path (1), the temperature at the tip of the convex portion is not 800°C, but is, for example, 600°C.

This temperature is also considered to be due to the heat generated by the flow path (1) being transferred. 21st F(a) band-shaped metal heating element 2
Insert the coupling device 5 of FIG. 1(c) into the hole 6 of the supporting device 4.
FIG. 1(a) shows the band-shaped metal heating element 2 fixed therein, and FIG. 1(b) shows the cross-sectional view taken along the χ-X° line. The support device 4 is made of a heat-resistant inorganic material such as glass or ceramic. Further, the coupling device 5 is made of heat-resistant stainless steel. A specific example will be described below.

Figure 2 shows 0.05mm steel plates made of iron, chromium, and aluminum (
A band-shaped metal heating element 2 was punched out so as to have a meandering shape and a convex portion as shown in a). This band-shaped metal heating element 2 has a total length of 2
m and the middle is 6 mm. As shown in FIG. 2(a), the convex portion was rectangular in size, rlt 6 mm, depth 18 mm, and a hole of 3 mmφ was drilled at the tip of the convex portion. A stainless steel coupling device 5 as shown in FIG. 1(c) was inserted into this hole, and the pipe was sandwiched and fixed between a 3.2111 mφ heat-resistant glass pipe as shown in FIG. 1(b). This planar heating element 1 has a power of 100V and 1.2KW. When a voltage was applied, it took several seconds to reach 700°C at the design temperature of 800'C, and 800°C was reached after 1 minute. This is because the main current path of the band-shaped metal heating element 2 is not in contact with other objects, so no heat is removed by thermal conduction.

When the main current path of Saramuko was 800'C, the tip of the protrusion was black. This is because the temperature at the tip of the convex portion is 600°C or less. The band-shaped metal heating element 2 and the support device 4 are integrated by a coupling device at the tip of the convex portion, but as mentioned above, the temperature at this portion is low and the contact area at this portion is small, so that heat is generated. Less loss. This increases the rate of temperature rise.

Example 2 A band-shaped metal heating element 2 was obtained in the same manner as in Example 1.

In this example, the configuration of the convex portion is different from Example 1, as shown in Fig. 3 (
The configuration is shown in a). The dotted line part in FIG. 3(a) is bent as shown in FIG. 3(b), and a glass pipe is inserted therein as a support device 4 to support the band-shaped metal heating element.
By fixing, a planar heating element 1 was obtained. When a voltage is applied to this, the temperature rises to 70'C in a few seconds as in Example 1.
The temperature reached 800'C after 1 minute.

Example 3 A band-shaped metal heating element 2 was obtained in the same manner as in Example 1.

In this embodiment, a hole is provided at the tip of the rectangular convex portion. The dotted line part in Fig. 4(a) is bent to form the shape as shown in Fig. 3(b), and a supporting device 4 made of a glass pipe is inserted into the hole 6 to support and fix the band-shaped metal heating element, thereby producing a sheet heating element. Obtained body 1. The arrangement of the protrusions is not limited to that shown in FIG. 4(a), and may be provided on one side or alternately. When a voltage is applied to this planar heating element 1, it reaches 700°C in a few seconds as in the case of Example 1, and after 1 minute it reaches 80°C.
It reached 0'C.

Example 4 A band-shaped metal heating element 2 was obtained in the same manner as in Example 1.

The convex portion has a notch 7 instead of the hole shown in FIG. The same results as in Example 3 were obtained by applying current. In actual use, a portion with a convex portion has a larger cross-sectional area and a lower resistance than a portion without a convex portion. Therefore, the temperature rise is also low. As a result, a difference in redness occurs in the main body of the strip body due to a difference in temperature rise. Fig. 6 is an attempt to reduce this difference in red heat as much as possible, and is intended to minimize the width of the composite portion of the belt body and the convex portion.

Furthermore, in FIG. 7, when a convex portion is provided, a hole 8 is provided in the center of the front band in order to make the cross-sectional area of this portion as similar as possible to the cross-sectional area of other portions.

By doing so, the temperature difference can be reduced.

Effects of the Invention As described above, the planar heating element of the present invention provides the following effects.

That is, in the planar heating element of the present invention, projections are provided at a plurality of locations on the band-shaped metal heating element, and these projections are used to fix the band-shaped metal heating element to the support device. That is, the band-shaped metal heating element can be fixed by folding the convex portion or by providing a hole or notch and easily attaching the support device to the convex portion. Furthermore, since the band-shaped metal heating element only partially contacts another object, there is very little heat transfer to the object by heat conduction. However, at -9, the temperature upper limit quickly rises to a high temperature in a short time, and the object to be heated can be radiantly heated at a high temperature.

[Brief explanation of the drawing]

FIG. 1(a) is a plan view of a planar heating element according to an embodiment of the present invention, FIG. 1(b) is a sectional view taken along line +x-x' of FIG. 1(a),
FIG. 1(c) is a front view showing an example of a coupling device, and FIG. 2(c) is a front view showing an example of a coupling device.
a) is a plan view of the band-shaped metal heating element of the same planar heating element, FIG. 2(b) is an enlarged plan view of the convex part of the same band-shaped metal heating element, and
a) is a plan view showing another convex portion of the band-shaped metal heating element;
Figure (b) is a sectional view showing the case where the support body is inserted into the convex part,
Fig. 4(a) is a plan view showing another convex portion of the band-shaped metal heating element, Fig. 4(b) is a front view showing the case where a support device is provided in Fig. 4(a), and Fig. 5 (a) is a plan view showing another convex part of the same strip-shaped metal heating element, FIG. 5(b) is a front view showing the case where a support device is provided in the same strip-shaped metal FIG. 7 is a plan view showing another convex portion of the heating element. FIG. 7 is a plan view showing another convex portion of the band-shaped metal heating element. DESCRIPTION OF SYMBOLS 1... Planar heating element, 2... Band-shaped metal heating element, 3... Protrusion, 4... Support device,
5... Coupling device, 6... Hole, 7...
...notch. Ward C1 Regret No.

Claims (3)

[Claims] (1) A band-shaped metal heating element in which a plurality of convex portions are provided in the same plane and holes or notches are provided in the convex portions, a support device that supports the band-shaped metal heating element, and the band-shaped metal heating element. A planar heating element comprising a coupling device that integrates the body and the support device. (2) A belt-shaped metal heating element in which a plurality of projections are provided in the same plane and the projections are bent, and a support device that supports the belt-shaped metal heating element, are arranged so that the projections are bent. A planar heating element that is integrated at the point where it is heated. (3) A belt-shaped metal heating element in which a plurality of projections having holes or notches are provided in the same plane, and the projections are bent, and a support device that supports the belt-shaped metal heating element are connected to the projections. A planar heating element that is integrated with a hole or notch provided in the section.