JPS61165980A - Heat generating body - 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 the Invention 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 have been implemented in various ways, such as space heaters and sheathed heaters, and are used to treat serious injuries. As a conventional space-type mica heater,
For example, one disclosed in Japanese Patent Application Laid-Open No. 53-32430 is known. This is constructed as shown in Figs. 7 to 10. 1 is an insulating substrate around which a heating wire 2 is wound, through-holes 3 are provided at appropriate places, and an upper insulating plate 4 and a lower insulating plate 1 are provided on both backs. A plate 5 is provided. The upper insulating plate 4 is also provided with an appropriate number of through holes 6, and the through holes 6 are covered with molten metal for short circuiting of S conductivity such as aluminum JRI1m7.
is placed. Here, the insulating substrate 1 and the upper insulating plate 4
The through holes 3 and 6 are provided with guard holes at corresponding positions. still,
An auxiliary insulating plate 8 is provided on the L side of the short-circuiting molten metal @7, and the whole is laminated in a clear press-bond state with a metal presser i9.10, and a liquid-tight structure is made with a metal case 11.12. A hole is provided in the center of the metal case 12, and the lead portion 14 of the heating wire 2 is guided out through the hole through which the lead portion 14 of the heating wire 2 is protected by a magnetic tube 15.

The conventional example shown in FIG. 7 is an example of an electric box 1-,
16 is a pot body, and 17 is a heating element.

Problems to be Solved by the Invention With such a conventional configuration, the lamination adhesion of the multiple components 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. Design considerations that ensured a certain durability life were essential. For this reason, specific measures include: ■ Improving the processing accuracy of heating element components, preventing deformation and warping in their initial state, ■ Improving the method of clamping the periphery of the metal case containing insulating plates and metal holding plates, ■ The need for countermeasures against changes during energization and over time, including these; ■ Corresponding to item 00 above, the power density (W/c
It is necessary to set Il) as large as possible within the allowable cost value, ■ If a temperature overrise prevention structure is built-in, the number of parts will increase and the structure will become complicated, so measures for items 0 to 0 above will be more necessary, etc. had to deal with the problem.

The present invention is intended to solve these problems, and aims to provide a heating element with a simple structure for preventing excessive temperature rise and increased durability.

Means for Solving the Problem In order to solve this problem, the present invention provides a heat generating board, a heat diffusion member with good thermal conductivity installed closely on the bottom surface of the heat generating board, and a heat dissipating member that covers the top surface of the heat generating board. It includes a heat transfer member and a back member that covers the lower surface of the heat diffusion member, and 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 each of the heat generation plate, the heat diffusion member, and the back member is A through hole is formed in the center and an annular recess is provided on the L surface of the back member.

Function: With this configuration, when the heating element is energized, 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 the durability life.In addition, when the heat diffusion member starts to melt during dry firing, the melted heat diffusion member is transferred to the back member. It flows into the recesses of the heating element and stays there, artificially forming a large space layer inside the heating element, causing the temperature of the heating wire to rise abnormally and leading to disconnection, thereby ensuring safety.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 6.

In the figure, 21 is a ■-shaped heat transfer member having a side edge 22 on the outer circumferential side, 23 is a dish-shaped back member having a side edge 24 on the outer circumferential side, and has a through hole 25 in the center facing upward. A protrusion 2G is formed. Four substantially annular portions 23a are provided on the upper surface of the back member 23 so as to surround the protrusion 2G. 27 is a heating wire 29 on a ring-shaped insulating substrate 28
This heat generating board 27 has ring-shaped insulating plates 30a and 30b stacked on top and bottom to form a heat generating board 31. Reference numeral 32 denotes a heat diffusion member having good thermal conductivity and having a through hole 32a in the center and an outer peripheral side portion 32b, which is closely attached to the lower side of the heat generating plate 31. The back member 23 located below the heat diffusion member 32 covers the heat transfer member 21 from the upper surface of the heat generating plate 31 with the side edge 22.
24 at the center, and holds the heat generating plate 31 and the heat diffusion member 32 in a sandwiched state. In addition, the heat diffusion member 3
The outer circumferential side portion 32b of No. 2 is tightly 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. 33
is a lead wire drawn out from the heat generating plate 27.

In the above configuration, the heating wire 29 is heated by passing current through the heating wire 29 from the lead @ 33, and the heating board 3
1 is heated. The heat generated at this time is quickly conducted through the heat transfer member 21 and the heat diffusion member 32, and is radiated from the side edges 22 of the heat transfer member 21. That is, when the heat transfer member 21 is used as a heat radiation surface, the heat from the upper surface of the heat generating plate 31 is transferred to the heat transfer member 21.
More heat is dissipated. In addition, the heat from the bottom surface of the heat generating plate 11 passes through the heat diffusion member 32 and the heat transfer member ! Because it is quickly conducted in the direction of the periphery of 1, the heating wire shi! This significantly lowers the wire temperature of the heating wire 9 itself and extends the durable life of the heating wire 29. In addition, thermal deformation and warpage of the insulating substrate 28, insulating plates 30a, 30b, etc. due to the high temperature of the heat generating plate 27 are caused by the heat generating plate 31 being caused by the back member 23, the heat diffusion member 32, and the heat transfer member 21. This is prevented because both sides are sandwiched. Furthermore, when the durability is set to the same level as the conventional one, it is possible to set the power density <W/-) to a high density, and the size of the heating element can be made compact.

When the heating element having the above configuration is applied to an electric heating device and energized for dry firing, since the built-in heat diffusion member 32 has a relatively low melting point, it starts to melt and the back member 23 is heated as shown in FIG.
It flows into and stays in the approximately annular recess 23a provided on the top surface, and at the same time, a large space layer is generated between the heat transfer member 21 and the back member 23, and the heating wire 29 is heated to an even higher temperature, leading to wire breakage. be. If the recess 23a is set to an appropriate size, the molten substance of the heat diffusion member 32 will not flow out of the heating element and will not come into contact with the lead wire 33 and the heating wire 29, so that it can be removed after the wire is disconnected. This guarantees electrical insulation.

Where? S The heat transfer member 21 and the back member 23 include:
18-8 stainless steel plate, 13-18% chrome, 0.5
If a ferritic stainless steel plate containing ~2% molybdenum is used, joining becomes extremely easy.

Effects of the Invention As described above, according to the present invention, the heat generating plate is sandwiched between the heat transfer member having good heat conduction, the heat diffusion member and the back member, and the peripheral portions of these members are brought 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 heat generated from the bottom surface of the heat generating member is transferred from the periphery of the heat transfer member to the heated object through the heat diffusion member and the back member. By dissipating heat, it is possible to prevent heat from accumulating inside the heating element, lowering the temperature, and improving durability. Furthermore, the simple structure of providing a recess on the upper surface of the back member actively guides the heating wire to disconnection when the temperature rises to ensure safety.

[Brief explanation of the drawing]

Figures 1 to 6 show one embodiment of the present invention.
The figure is a sectional view, Figure 2 is a front view, Figure 3 is a cutaway plan view of the main part of the heat generating plate, Figure 4 is a perspective view of the heat diffusion member turned over, and Figure 5 is a perspective view of the back member. , Fig. 6 is a sectional view showing the state of the heating element when the temperature rises, Figs. 7 to 10 show the conventional example, Fig. 7 is a partially cutaway front view of the electric kettle, and Fig. 8 is A sectional view of the heating element, FIG. 9 is an enlarged sectional view of the main part of the heating element,
FIG. 10 is an exploded perspective view of the heating element components. DESCRIPTION OF SYMBOLS 21... Heat transfer member, 22... Side edge, 23... Back member, 23a... Recessed part, 24... Side edge, 25...
...Through hole, 26...Protrusion, 27...Heating plate, 28
... Insulating substrate, 29 ... Heating wire, 30a.

Claims (1)

[Claims] 1. A heat-generating plate, a heat-diffusion member with good thermal conductivity installed closely on the lower surface of the heat-generating plate, a heat-transfer member covering the upper surface of the heat-generating plate, and a back member covering the lower surface of the heat-diffusing 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 an annular recess is provided on the upper surface of the back member. heating element.