JPS60212987A - Sheathed heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a sheathed heater that is widely used as a heating source for general cooking appliances and commercial cooking equipment.〇Conventional structure and problems thereof 2. Description of the Related Art Conventionally, /-Z heaters have been widely used as a heating source for general cooking appliances such as toaster ovens, microwave ovens, rice cookers, and hot plates.

This is because the sheathed heater is simple, highly safe, and has excellent zero resistance.

Also, recently, electric ovens, yakiniku, and kageyaki have become popular.

Using a sauce containing a large amount of salt such as yakitori,
Cooking appliances that can be used under saline water conditions are widely available in the world, and sheathed heaters are no longer being used as a heating source for these appliances.

Generally, in a sheathed heater, a coiled heating wire with VC electricity extraction ends r at both ends is inserted into the center of a metal pipe, and this metal pipe is filled with electrically insulating powder made of fused Magnenoa powder. Both ends are sealed with low melting point glass and heat resistant resin.

On the other hand, since sheathed heaters used in electric ranges, yakiniku, kabayaki, and yakitori equipment are used at high temperatures, NCF300 (trade name Incoloy 80o) is used as the metal pipe, and 5USso4 is used as the electrical outlet terminal.
are used, and the gap between the metal pipe and the air outlet terminal is sealed with low-melting glass to ensure electrical insulation.11. I'm nestling.

As this low melting point glass, a glass material having a coefficient of linear expansion suitable for the respective materials of the metal pipe (ncysoo) and the electrical outlet terminal (5US304) is used.

That is, a low melting point glass having a linear expansion coefficient of 110 to 13 o x 1 o/C is used.

However, when using the Z-heater made of the -F constituent materials as a heating source for the above-mentioned electric ovens, yakiniku, kageyaki, etc. Dripping causes the metal pipe to corrode in a short period of time, resulting in cracking of the pipe and subsequent disconnection of the heating wire.
The reality is that there is a problem.

For this reason, the present inventors have already proposed the use of NCF600, which has a high nickel content, as a metal bubble.

However, using N CF 600 as a metal pipe,
When a nose heater is manufactured using a conventional 5US304 electrical outlet terminal and a glass material with a linear expansion coefficient of 110 to 130 x 10/''C as a low melting point glass, the corrosion resistance against salt etc. increases significantly. Although the effect was obtained, the glass broke during the sealing work on the 1st floor with low melting point glass, and during use, moisture etc. entered through the broken part of the glass, and the electrical insulation between the metal pipe and the electrical outlet terminal deteriorated, causing the equipment to fail. '- A problem arose in which the power decreased.

OBJECTS OF THE INVENTION The present invention provides a heater which eliminates the above-mentioned conventional drawbacks and has excellent corrosion resistance +'I and electrical insulation properties in an environment where common salt is used.

Structure of the Invention In the present invention, NCF300° is used as the metal pipe, and 5US430LX is used as the electrical extraction terminal, and the gap between the metal pipe and the electrical extraction end r is 80 to 100×10.
A nose heater made of low melting point glass with a linear expansion coefficient of -'/°C, which replaces the conventional metal pipe with N
By changing to CF 600, the resistance to salt etc. is increased (and by matching the coefficient of linear expansion of metal pipes, electrical outlet terminals, and low melting glass),
Electrical insulation is improved by completely sealing the metal vibro part.

Description of examples A specific embodiment of the present invention will be described with reference to FIG.

(Example) As the metal pipe 3, NCF800 (trade name Incoloy 800) or NCF600 (trade name Inconel 60o) is used.
), and use 5US304-i as the electrical outlet terminal 1.
Nichrome wire of type 1 was used as the heating wire 2.

In addition, as the low melting point glass 6, 70 to 130X10/°
A range of C was used.

The above-mentioned materials are combined as shown in Table 1, and the diameter is 11mm, the length is 6001RM, and the power is 100V-800W.
completed the nose heater.

/-'s heater is made by placing a coiled heating wire 2 connected to an electricity extraction terminal 1 in the center of a metal pipe 3. After diameter reduction, the metal pipe 3 was annealed, and both ends of the metal pipe 3 were sealed with low melting point glass 6 and NRIKO 7 mtlE.

Sample numbers 1 to 12 were used for the completed /-Z heaters.

Sample numbers 1 and 2 are conventional 7-Z heaters using conventional construction materials, and samples t1 numbers 3 and 4 use NCF600 for the metal pipes, and the electrodeposited terminals and low melting point glass are conventional R4F' 1 is used.

-) J sample numbers 6 to 12 1, NCF600 and 5US430LX as metal pipe and electric deposited end r
i is used, and low melting point glasses with different linear expansion coefficients are changed respectively.

(Left below) Table 1 In order to evaluate each sheathed heater in Table 1, the applied voltage was adjusted so that the temperature of the metal pipe was ao o'c, and after applying saturated saline, the metal pipe was energized for 20 min - 10 min. A zero resistance test was conducted by intermittent energization with one cycle of rest, and the cycle in which the sheathed heater was disconnected was determined. The results are shown in Table 1.

The saturated saline solution was applied once every 50 cycles.

On the other hand, in order to check the reliability of the glass seal, the electrical insulation between the metal pipe and the electrical outlet terminal was measured using an insulation meter after it was placed in a constant temperature and humidity chamber at 40°C and relative humidity of 96% for one month. . At this time, the case where the value is 2000MΩ or more is indicated by a circle, and the case where the value is 2000MΩ or less is indicated by an X mark. The sheathed heaters of sample numbers 1 and 2 had excellent glass sealing reliability, and no deterioration in electrical insulation was observed even when placed in a constant temperature and humidity chamber at 40° C. and 95% relative humidity.

However, in the corrosion resistance test, the wire broke at about the SOO cycle and favorable results could not be obtained.

Sample numbers 3 and 4, which used NCF600 for the metal pipe and 5t JS304 for the electrical outlet terminal, were
Although no significant effect was obtained in the capital resistance test, the reliability of the glass seal is lacking.

Furthermore, test F1 numbers 5, 11 and 12 use NCF600 for the metal pipe and 5US430L for the electrical outlet terminal.
However, the linear expansion coefficient of the low-melting point glass did not match, and the glass seal lacked reliability despite its excellent corrosion resistance.

However, sample numbers 6, 7, 8.9 and 1o, which used N G F600'i for the metal pipe, 5US430LX for the electrical outlet terminal, and a low melting point glass with a coefficient of linear expansion of 80 to 100X10/C, The sheathed heater of the present invention has excellent glass sealing reliability, and
A remarkable effect was obtained in terms of resistance to 11 cycles.

In this way, by using NCF600 with metal-ζ eaves, it can withstand 1f! By using 5US430LXf low melting point glass material with a coefficient of linear expansion of 80 to 10 x 1o/C for the electrical outlet terminal, we were able to obtain a glass seal reliability of 1.

This means that the linear expansion coefficient of conventional NCF300 is 17o~
180×1o10C, and the linear expansion coefficient of NCF600 is as small as 140 to 160×10/° (:
600 metal pipe is used, and the electric outlet terminal has a conventional 5trs3o4 (linear expansion coefficient 170 to 180x1).
o/'C) Also, as a low melting point glass, 110 to 130 x 1
Using a glass material with a coefficient of linear expansion of 0-diC, when melting and cooling the glass, the conventional N CF 8
This is because, compared to NCF600, cracks occur between the glass and the metal pipe because the degree of storage is smaller in NCF600.

However, the S U 5430LX (110~
By using 120X10/"C)f, the degree of shrinkage during cooling is matched, and the glass is prevented from becoming eroded.
-I can do it.

In addition, in the embodiment of the present invention, 5 (JS
430LX was used, but this material is the conventional 5US430 containing T1 in the range of 0.1 to 1.0%, and is 5U.
This is an improved version of S430 in terms of high temperature strength, etc.

Effects of the Invention As is clear from the following explanation, according to the heater of the present invention, NCF600 is used as the metal pipe, 5US430LX is used as the electrical outlet terminal, and the gap between the metal pipe and the electrical outlet terminal is 80 to 80 mm. 100X1
It is sealed with low melting point glass having a coefficient of linear expansion of 0'/''C, and as a result, it is possible to obtain a heater with excellent resistance to salt etc. and electrical insulation. Its practical value is great.

[Brief explanation of drawings]

The figure is a sectional view of a 7-Z heater according to an embodiment of the present invention. 1 Electrical outlet terminal, 3 Gold oval pipe, 6 Low melting point glass.

Claims (1)

[Claims] As a metal pipe, NCF600. A sheathed heater 0 in which 5US430LX is used as an electricity extraction terminal, and the gap between the metal pipe and the electricity extraction terminal is covered with a low melting point glass having a linear expansion coefficient of 8o to 100X10/°C.