JPH039595B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heating element for an electric heating appliance for heating liquids such as water, milk, and alcoholic beverages in general households.

2. Description of the Related Art In general, conventional heating elements for electric heating appliances are provided on the market in various embodiments such as space heaters and sheathed heaters. As a conventional space-type mica heater, for example, Japanese Patent Application Laid-Open No. 53-32430
The one shown in the publication is known. This is constructed as shown in FIGS. 7 to 10. In other words, an insulating substrate 1 around which a heating wire 2 is wound is provided with through holes 3 at appropriate locations, and an upper insulating plate 4 and a lower insulating plate 4 are provided on both back sides. An insulating plate 5 is provided. The upper insulating plate 4 is also provided with a suitable number of through holes 6, and a conductive molten metal plate 7 made of aluminum or the like for shorting is placed so as to cover the through holes 6. Here, the through holes 3 and 6 of the insulating substrate 1 and the upper insulating plate 4 are provided at corresponding positions, respectively. An auxiliary insulating plate 8 is provided on the upper surface of the short-circuiting molten metal plate 7, and the entire plate is sandwiched and laminated with metal holding plates 9 and 10, and metal cases 11 and 12 are arranged to form a liquid-tight structure. Also,
A hole is provided in the center of the metal case 12, and the lead portion 14 of the heating wire 2 is passed through the hole.
is guided out while being protected by a magnetic tube 15. In addition, the seventh
The conventional example shown in the figure is an example of an electric pot.
1 is the pot body, and 17 is a heating element.

Problems to be Solved by the Invention With such a conventional configuration, the lamination adhesion of each component of the heating element is made as good as possible to prevent the wire temperature of the heating wire itself from increasing due to the generation of a space layer, and to maintain a constant temperature. Design considerations that ensured a durable life were essential. For this reason, specific measures include improving the machining accuracy of the heating element components, preventing deformation and warping in the initial state, and devising a method for clamping the periphery of the metal case that houses the insulating plate and metal holding plates. It is necessary to take measures such as when energizing and changes over time, etc. In response to the above item, it is necessary to set the power density (W/cm ² ) of the heating element as high as possible within the allowable cost, and when a built-in temperature rise prevention mechanism is required. , as the number of parts increased, the structure became more complex, and the above-mentioned measures had to be taken more seriously.

The present invention solves these problems,
The purpose of this invention is to provide a heating element with a simple structure, good heating efficiency, and extended durability.

Means for Solving the Problem In order to solve this problem, the present invention provides a heat generating board having a heat generating element, a heat diffusion member having good thermal conductivity installed closely on the lower surface of the heat generating board, and a a heat transfer member that covers an upper surface; and a back member that covers a lower surface of the heat diffusion member; A through hole is formed in each center of the member, and the heat generating element is formed so that the amount of heat generated increases as it goes toward the outer circumference, and the heat diffusion member has a thickness that gradually increases from the inner circumference toward the outer circumference. It was set up so that

Effects With this configuration, when electricity is applied to the heating element, heat is radiated from the heat transfer member, and heat from the lower surface is quickly conducted to the periphery through the heat diffusion member, and is radiated upward from the periphery. Since heat is quickly conducted through the heat transfer member, the wire temperature of the heating wire itself is significantly lowered, extending its durable life, and the heat diffusion member is designed so that it becomes thicker from the inner circumference to the outer circumference. Therefore, the amount of heat diffusion is made larger in the outer circumferential portion than in the central portion of the heating element, thereby increasing the amount of heat diffusion toward the peripheral portion, and increasing the heating efficiency due to the above-mentioned good conductivity.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

In the figure, 21 is a dish-shaped heat transfer member having a side edge 22 on the outer periphery and an upward protrusion 21a in the center, and 23 is a plate-shaped heat transfer member with good heat conduction.
It is a dish-shaped back member having an upward protrusion 26 having a through hole 25 in the center. 27
is a heating element made of a high-resistance thin metal plate (for example, nickel chrome, nickel, iron/chrome, stainless steel, aluminum, etc.) formed into a desired shape by pressing, etching, etc.
This heating element 27 has ring-shaped insulating plates 28 and 29 stacked on top and bottom to form a heating plate 30. This heat generating plate 30 is stacked on the back surface of the heat transfer member 21, and the central hole is fitted into the protrusion 26 of the back surface member 23.

31 has a through hole 31a in the center, and the outer peripheral side part 31
A heat dissipating member with good thermal conductivity, such as aluminum, aluminum alloy, copper, etc., is made thicker from the inner circumference toward the outer circumference, and this
It is closely attached to the bottom of 0. This heat diffusion member 31
The back member 23 located below the heating plate 30
The side edge 22, the peripheral edge 24, and the central projections 21a and 26 are connected to the heat transfer member 21 which covers the upper surface of the heat transfer member 21, and holds the heat generating plate 30 and the heat diffusion member 31 in a sandwiched and crimped state. The outer circumferential side portion 31b of the heat diffusion member 31 is strongly adhered to the outer circumferential side portion of the heat transfer member 21, and is made of a relatively low melting point metal with good thermal conductivity such as aluminum or aluminum alloy. There is. 32 is a lead wire drawn out from the heat generating plate 30.

As shown in FIG. 4, the heat generating element 27 is electrically shaped so that the temperature is higher in the outer circumferential direction than in the center when energized.

In the above configuration, by passing current through the lead wire 32 to the heat generating element 27, the heat generating element 27 is heated, and the heat generating plate 30 is heated.
The heat generated at that time is quickly conducted through the heat transfer member 21 and the heat diffusion member 31, and the side edge 2 of the heat transfer member 21
Heat is dissipated from 2.

That is, when the heat transfer member 21 is used as a heat radiating surface, the heat from the upper surface of the heat generating plate 30 is radiated from the heat transfer member. In addition, since the heat from the lower surface of the heat generating plate 30 is quickly conducted to the circumferential direction of the heat transfer member 21 via the heat diffusion member 31, the linear temperature of the heat generating element 27 itself is significantly lowered and the durability of the heat generating element 27 is extended. It is something that extends the. In addition, since the linear temperature of the heat generating element 27 increases as it goes toward the outer circumference, [that is, the amount of heat generated increases as it goes toward the outer circumference], the heat dissipation member 31 increases in the outer circumferential direction. By increasing the thickness, heat diffusion is increased downward and to the sides to compensate for the increase in linear temperature, and the heat is dissipated from the side edges 22 of the heat transfer member 21.

The heat deformation and warping of the insulating plates 28 and 29 due to the high temperature of the heat generating element 27 causes the heat generating plate 30 to
Since both sides are sandwiched by the heat transfer member 21, this is prevented. Furthermore, when the durability is set to the same level as before, it is possible to set the power density [W/cm ² ] to a high density due to the aforementioned good conductivity and good heat dissipation, and the size of the heating element can be reduced. It can be made compact.

Note that even if the thickness of the heat diffusion member 31 is increased in the outer circumferential direction as shown in FIGS. 5 and 6, the effect will be the same, but the choice should be made depending on the electric heating device, structure, processing of parts, accuracy, etc. It's a good thing.

The above embodiment uses a heating element 27 made of a high-resistance thin metal plate, but it is formed by winding a heating wire around an insulating substrate (mica, mica night, etc.) that is used in general space heaters. Needless to say, the heat dispersion member 31 of the present invention may be used even in a heat generating board made of a heat generating plate.

As the heat transfer member 21 and the back member 23, 18
-8 stainless steel plate, 13-18% chrome, 0.5-2
If a ferritic stainless steel plate containing % molybdenum is used, joining will be extremely easy.

Effects of the Invention As is clear from the description of the embodiments above, according to the present invention, the heat generating plate is made of a heat transfer member having good heat conduction.
By sandwiching the heat diffusion member and the back member, and by bringing the peripheral edges of these members into close contact with each other, the heat generated from the heat generating plate is effectively radiated from the heat transfer member to the heated object, and the lower surface of the heat generating member The heat generated by the heating element is radiated from the peripheral edge of the heat transfer member to the heated object through the heat diffusion member and the back member, thereby preventing heat from accumulating inside the heating element, lowering the temperature, and increasing durability. .

Further, since the heat diffusion member 31 is made thicker in the direction of the outer circumference, the above-mentioned amount of heat diffusion can be rapidly and effectively guided towards the outer circumference, thereby positively increasing the temperature reduction and the extension of durability.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention, with Figure 1 being a cross-sectional view, Figure 2 being a front view, Figure 3 being a perspective view of a heat diffusion member, and Figure 4 being a diagram of a heat-generating plate. The main part cutaway plan view, FIGS. 5 and 6 show cross-sectional views of other embodiments. 7 to 10 show conventional examples;
8 is a sectional view of the heating element, FIG. 9 is an enlarged sectional view of the main part of the heating element, and FIG. 10 is an exploded perspective view of the components of the heating element. 21... Heat transfer member, 23... Back member, 26...
...Protruding portion, 27... Heat generating element, 30... Heat generating board.

Claims (1)

[Claims] 1. A heat generating plate having a heat generating element, a heat transfer member covering the upper surface of the heat generating plate, a heat diffusion member having good thermal conductivity installed in close contact with the lower surface of the heat generating plate, and a back member covering the lower surface of the heat diffusion member. The peripheral edges of the heat transfer member, the heat diffusion member, and the back member are brought into close contact with each other, and a through hole is formed in the center of each of the heat generating plate, the heat diffusion member, and the back member, and the heat generating element is directed toward the outer periphery. The heating element is formed so that the amount of heat generated increases as the heat dissipation member goes forward, and the heat diffusion member gradually becomes thicker from the inner circumference toward the outer circumference.