JPH0236232Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention is a heating element of a far-infrared heater, which is embedded in an inorganic board with excellent electrical insulation and heat resistance, and which reduces the resistance caused by energization. This is the structure of a heating plate for an electric heater that is used to generate Joule heat through exothermic action. Specifically, it is a plate-like plate with a uniform thickness, and a band-shaped plate part of a constant width or approximately constant width is hammered out in a continuous wave shape from a plate-shaped conductor with a uniform thickness. Concerning what is formed.

<Prior art> The heating plate having the above structure has a smaller bulk than a sheathed wire made by winding a conducting wire (heating wire) into a coil, such as a nichrome wire, and the heater itself can be made more compact. In addition, since the conductor band-like plate has a continuous wave shape, the width of the plate-like conductor is smaller than that of a plate-like conductor in which a band-like plate of a constant width or approximately constant width is formed by punching out a linear shape from the plate-like conductor. It has the advantage that the path length in the direction can be increased, the amount of heat generated per unit area can be increased, and heat generation characteristics comparable to those of the above-mentioned sheathed wire etc. can be obtained.

Therefore, conventionally, this type of heating plate is
The belt-shaped plate portion was formed by continuous stamping into a round wave shape.

<Problems to be solved by the invention> However, in the case of the heat generating plate having the above-mentioned continuous round wave shape, since the bent corners are rounded, the bending corners are rounded. There is no local red-hot phenomenon at the corners, which makes it possible to equalize the current density and therefore the amount of heat generated, and there is no problem with the heat resistance of the constituent materials caused by the local red-hot phenomenon at the corners. Although it is possible to ensure a sufficiently long service life for the heat generating plate as a whole, the shape of the punching die used for punching out the rounded product is complicated, and the cost required for making the die is high.
This had the disadvantage of increasing the cost of the heating plate itself.

<Means for solving the problems> In view of the above circumstances, the present invention has been developed to easily and inexpensively produce a device with a large pass length and excellent heat generation characteristics, and which is equivalent to the conventional round wave shape. The object is to provide a structure of a heating plate for an electric heater that has a long service life.

In order to achieve the above object, the structure of the heat generating plate for an electric heater according to the present invention is as described in detail at the beginning. , and is characterized in that the intersecting angles of adjacent plate sides are at right angles or substantially right angles, and arcuate cuts are formed at each inner corner.

<Function> The heat generating plate for an electric heater according to the present invention having the above configuration is embedded in an electrical insulator, and by applying a voltage across both ends of the wavy band plate, A current that is inversely proportional to the resistance that is proportional to the total length in the direction of the wavy line is passed, and the resistance heating effect generates Joule heat in the band-shaped plate.In this case, the band-shaped plate is Or, since the two right sides of a substantially right-angled isosceles triangle are continuous, so-called sawtooth, the current path length is sufficiently long, and each right-angled interior corner has an arc-shaped cut, so The current flows in a detour around the inner corner, so there is no phenomenon where the current concentrates on the inner corner and the inner corner becomes locally red hot. Therefore, even at the right angle corner, the current density in the width direction of the strip plate is It is uniform and there is no distribution in the amount of heat.

<Example> Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 2, reference numeral 3 denotes a plate-shaped conductor having a uniform thickness and a constant width over its entire length, and is made of nickel cloth alloy or stainless steel.
1 is a plurality of rows in the longitudinal direction of the plate-shaped conductor 3, and the plate-shaped conductors 3 are pressed in such a state that adjacent ones in the longitudinal direction are arranged alternately at both ends in the width direction of the plate-shaped conductor 3. Therefore, each row of strip-shaped plate portions is stamped in a zigzag shape and has a constant width, and each of these strip-shaped plate portions 1 is formed in a sawtooth waveform. More specifically, as clearly shown in FIG. 1, the two types of plate side portions 1A and 1B that are inclined to each other, like the two right sides of a right-angled isosceles triangle, are both linear, and the two adjacent side portions are linear. The plate sides 1A and 1B are formed by stamping so that each intersection angle θ is a right angle or a substantially right angle. Reference numeral 2 denotes a minute diameter arcuate cut formed at the inner corner of the right angle portion of each sawtooth continuous wave band plate portion 1 .

As shown in FIGS. 3 and 4, the heating plate A is embedded in an inorganic plate B having excellent electrical insulation and heat resistance to form a planar heating element C. C is used as a heat source for a far-infrared heater made by sandwiching a far-infrared radiation plate D and a reflection plate E made of, for example, a ceramic material, and integrating these through a case F. In addition, it can of course be used as a heat source for general electric heaters such as boiling water and boiling water.

In addition, in FIG. 2, in the width of each corrugated strip plate part 1 located in parallel in the longitudinal direction of the plate-shaped conductor 3, the width of the plurality of rows of strip plate parts 1 on both ends in the longitudinal direction is equal to the width of the plurality of rows of the middle part. The width of the strip plate portion 1 is smaller than the width of the strip plate portion 1, and a difference corresponding to the difference in the amount of heat dissipated from each zone is added to the amount of heat generated between the end zones and the intermediate zone, each of which is composed of a plurality of rows of the strip plate portions 1. Although it is shown that the heating temperature is made uniform or approximately uniform over the entire area of the heater by adding , the width may be the same for all the heaters.

<Effects of the invention> As is clear from the detailed description above, the invention according to the invention has the following advantages: (1) Since the heating element is plate-shaped, it is less effective than a sheathed wire made by winding a nichrome wire into a coil. (2) The band-shaped plate that makes up the current path length is not linear but has a continuous wave shape, so the path length is small considering the space occupied by the plate-shaped conductor. By increasing , the amount of heat generated per unit area can be made sufficiently large,
Of course, it has the effect of providing heat generation characteristics that are comparable to those of the sheathed wire, etc.; (4) Moreover, the shape of the punching die for press forming is simpler than that of a continuous round wave shape, and the production cost of the die and, by extension, the production cost of the heating plate itself can be reduced. By forming an arcuate cut in the inner corner where heat concentration tends to occur, it is possible to suppress red heat in the inner corner and the associated decrease in the service life of the entire heat generating plate, thereby reducing the cost mentioned in 3 above. (5) In addition, the amount of heat generated in the width direction of the strip plate portion can be made uniform or almost uniform, and uniform heating can be achieved over the entire area of the heater. This has led to the realization of remarkable practical advantages.

[Brief explanation of the drawing]

FIG. 1 is an enlarged plan view of a main part, FIG. 2 is an overall plan view, and FIGS. 3 and 4 are a perspective view and an enlarged longitudinal sectional view of an example of use. 1 is a band-shaped plate part, 1A and 1B are linear plate side parts, 2
3 is a circular arc-shaped cut, and 3 is a plate-shaped conductor.

Claims (1)

[Scope of Claim for Utility Model Registration] A heating plate for an electric heater, which is formed by punching out a band-shaped plate portion 1 of a constant width or approximately constant width into a continuous wave shape from a plate-shaped conductor 3 having a uniform thickness. , the two mutually inclined plate sides 1A, 1B constituting the continuous wave band-shaped plate part 1 are linear, and the intersecting angles θ of the adjacent plate sides 1A, 1B are at right angles or substantially right angles, and , a structure of a heating plate for an electric heater, characterized in that an arcuate notch 2 is formed at each inner corner. The structure of the heating plate for an electric heater according to claim 1, wherein the continuous wave band-shaped plate portion 1 is formed by punching out a plurality of rows in a zigzag shape in the longitudinal direction of the plate-shaped conductor 3 having a constant width. .