JPS62285385A - Electric wire 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 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to an electric wire heater used as a heat source for heating or heating equipment such as electric stoves and electric stoves.

Conventional technology Electric wire heaters made of nichrome wire, etc., which generate heat when energized, have been widely used as a heat source for electric stoves, electric heaters, etc., and are especially easy to start and stop. Because of its simplicity and low indoor air pollution, it is used as a heat source in highly airtight rooms.
ing.

Problems to be Solved by the Invention However, conventional heating wire heaters have a relatively small amount of heat generated per unit length of the heating wire, and are not necessarily satisfactory as a large-capacity heat source.

In other words, the table below shows the volume resistivity of JIS standard nickel-chromium heating wire and iron-chromium heating wire.

As shown in the linear expansion coefficient and melting temperature, the melting point was about 14 oO<0>C and 1500'C1, and the volume resistivity was about 1 oO to about 150, which was not satisfactory as a large-capacity heat source.

(Left below) On the other hand, as shown in the previous table, tungsten and molybdenum have high melting points and low volume resistivities, so if both can be used as electric heating wire heaters, they will be far more effective than conventional electric heating wires. This will provide a source of heat for Yokei.

However, as is well known, tungsten and molybdenum burn when heated with electricity in the air and cannot be used as heat generating materials in the air. It is used as. This infrared light bulb has a limited shape, and unlike a nichrome wire electric heater, it is difficult to use it close to or in close contact with the object to be heated, resulting in poor heating efficiency.

The present invention provides a wire heater that takes advantage of the features of tungsten and molybdenum and eliminates the above-mentioned drawbacks.

Means for Solving the Problems The electric wire heater of the present invention uses iron on the surface of a core wire whose main component is either tungsten or molybdenum.

It is constructed of a wire material into which at least one of nickel, chromium, and aluminum is diffused and infiltrated, and the outside of the core wire is molded with a heat-generating alloy whose main component is one of the metals into which the above-described diffusion and infiltration is made.

Tungsten or molybdenum can be constructed into relatively free shapes like nichrome wire, and can be used in close proximity to the heated object, while solving the problem of combustion when tungsten or molybdenum is heated in air with electricity. Alternatively, it is possible to use molybdenum as a core wire and cover its outer periphery with a nickel-chromium alloy to prevent the core wire from coming into direct contact with the air. Because the thermal expansion coefficients of the two materials differ greatly, peeling and cracking may occur during heating, or deformation may occur.

However, in the structure of the present invention, since the main component of the metal to be coated is diffused and permeated onto the surface of the core wire, if the core wire is heated to near the melting point of the coated metal after coating, the adhesion interface will be fused and bonded to form an alloy state. Therefore, the stress due to the difference in coefficient of thermal expansion between the core wire and the coating metal is absorbed step by step, and the above-mentioned inconveniences that occur during heating are eliminated.

EXAMPLE Hereinafter, an example of the electric wire heater of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of one embodiment of a heating wire used in the present invention. Reference numeral 1 indicates a core wire made of tungsten or molybdenum, and the surface thereof is coated with iron.

At least one metal of nickel, chromium, and aluminum, such as nickel, is used in CVD (ChemICa
The diffusion permeation layer 2 is formed by diffusion permeation using a vapor deposition method or the like. Reference numeral 3 denotes a heat generating material layer that can generate heat in the air and is mainly composed of the diffused metal (for example, nickel), and is, for example, a heat generating material layer of a type of nickel-chromium heating wire (JIS standard); This core wire 1 is molded in close contact with the outer periphery of the core wire 1.

After molding the core wire 1 with the heat-generating material layer 3, it is heat-treated in an inert gas atmosphere to near the melting point of the heat-generating material layer 3. Through this heat treatment, the interface between the core wire 1 and the heat generating material layer 3 is fused and bonded to form an alloy. 4 is an aluminum oxide layer formed on the surface of the heat generating material layer 3 by conventionally known means.

The wire having the above structure is wound into a coil shape in the same manner as conventional nichrome wire to form a heating wire heater. According to the above configuration, the core wire has a shape sealed by the heat generating material layer 3, so that it is cut off from oxygen in the air and will not be burned. The problem that arises from the difference in the coefficient of thermal expansion between the core wire 1 and the heat generating material layer 3 is also caused by the stress caused by the difference in the coefficient of expansion because a diffusion permeation layer, that is, an alloy of both, is formed at the interface between the core wire 1 and the heat generating material layer 3. The problem is solved by being absorbed in this alloy part in a step-by-step manner.

Furthermore, if an aluminum oxide layer is formed on the surface as in this embodiment, the electric wire heater 6 can be heated as shown in FIG.
When the coil elements are arranged vertically and used, even if adjacent coil elements come into contact with each other due to the weight of the coil itself, an electrical short circuit will not occur.

Alternatively, the core wire 1 having the diffusion layer formed on its surface may be formed into a coil or mesh shape, and the entire core wire of the coil or mesh may be covered with a heat generating material layer. be.

Effects of the Invention As described above, according to the present invention, the tungsten or molybdenum core wire has lower cold resistance than conventional electric heating materials, so a fast heating and high output heat source can be obtained. Since the mechanical strength is also high at high temperatures, a heating wire heater with excellent mechanical strength can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main parts of an embodiment of the electric wire heater of the present invention, and FIG. 2 is a perspective view of the main parts in the same state of use. 1...Core wire, 2...Diffusion permeation layer, 3...
... Heat generating material layer, 4 ... Aluminum oxide layer. 3 °−#4t7′t,”:=%y% gain

Claims (3)

[Claims] (1) At least one of iron, nickel, chromium, and aluminum is diffused and infiltrated onto the surface of a core wire whose main component is either tungsten or molybdenum, and the outside of the core wire is made of the metal that has been diffused and infiltrated. A heating wire heater characterized in that a coiled body is formed of a wire molded with a heat-generating alloy having one main component. (2) The electric wire heater according to claim 1, wherein the core wire is formed by twisting a plurality of single wires. (3) The electric wire heater according to claim 1, wherein the wire has a shape in which the entire core material, which has been previously wound into a coil shape, is molded with a heat-generating alloy.