JPH03149794A - Electric heating element - Google Patents

Abstract

PURPOSE:To improve durability, reliability and assembling property by providing such holes at the center of the second heating board and the third and fourth insulating materials that are larger than the holes provided at the center of the first heating board, the first and second insulating materials, and a heat diffusing plate, and providing two pressing faces corresponding to respective holes on the first back plate. CONSTITUTION:Holes a15-d18 are provided at the center of the first insulating material 9, the first heating board 7, the second insulating material 10 and a heat diffusing plate 4, holes e19-g21 larger than holes a15-d18 are provided at the center of the third insulating material 13, the second heating board 11 and the fourth insulating material 14, and they are fitted by the good-heat conductivity first back material 22 such as a surface-processed steel plate protruded upward at the center and having an outer periphery side section 22c, a through hole at the center, and two pressing faces 22a and 22b corresponding to holes a15-d18 and holes e19-g21 while a pressing margin is provided on the lower face of a heat transfer plate 1. Assembling property, safety and reliability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric heating element installed in an electric water heater for heating and keeping a contained liquid warm. As shown in FIG. 4, there is a heating plate 29 in which a main heating wire 27 and an auxiliary heating wire 28 are integrally wrapped around the bottom back side of a container 26 which is cylindrical with a bottom and has a heat transfer plate 26 protruding from the bottom. Insulating materials 30 and 31 covering the upper and lower surfaces of the housing and a heat diffusion plate 32 having good thermal conductivity were attached by a backing material 33.

Problems to be Solved by the Invention In such a conventional configuration, if an attempt is made to increase the softness of the heating element, the watt density will naturally increase.

In other words, as the temperature of the heating wire increases, the load on the heating wire increases, and the thermal expansion also increases accordingly, resulting in a durability problem in which the main heating wire and the auxiliary heating wire may short-circuit and break. .

The present invention solves the above problems and is durable.

The purpose is to provide a heating element with improved reliability and ease of assembly.

Means for Solving the Problem In order to achieve this object, the present invention provides a container having a cylindrical shape with a bottom and a heat exchanger plate protruding from the bottom. a covered first heating panel;
The power consumption is smaller than this first heat generating board, and the upper and lower surfaces are the third heat generating board.
and a second heat generating panel covered with a fourth insulating material: a panel, a heat diffusion plate with good thermal conductivity, and a first back plate are attached, and the second heat generating panel and the third and fourth heat dissipating panels are attached. A hole larger than the hole provided in the center of the first heating panel, the first and second insulating materials, and the heat diffusion plate is provided in the center of the insulating material, and the first back plate is provided with Two levels of holding surfaces are provided to correspond to the holes.

According to the above-described structure, the present invention includes a first heat generating plate, first and second insulating materials, and a heat diffusion plate in the center of the second heat generating plate and the third and fourth insulating materials. A hole larger than the hole provided in the central part of
Heat conduction from the heating element and radiant heat to the sensor detection surface provided in the center of the bottom is improved, improving dry cooking detection performance. In addition, since the diameters of the holes provided in the center of the heating panel and the insulating material are different, it is possible to prevent mistakes in the order of assembling the parts, thereby improving assemblability, safety, and reliability.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3.

In the figure, 1 is a heat exchanger plate whose central part protrudes upward in an abbreviated shape to form a circumferential side part 1a, and its outer circumferential part is fixed liquid-tightly to the lower end of the cylinder by means such as welding. A liquid storage container 23 made of solid metal is formed. This is an exterior body that wraps the container 23 with a space in between. A heating element portion 3 is attached to the lower surface of the heat transfer plate 1 via a heat conduction plate 2 having a flat plate shape and made of, for example, aluminum or surface-treated steel plate. This heating element section 3 consists of a first heating element 6 and a second heating element 6 disposed above and below a heat diffusion plate 4 of good thermal conductivity such as aluminum or surface-treated steel plate. The body 5 includes a first heating plate 7 wrapped with a first main heating wire 8 and a first heating plate 7 above and below.
has an insulating material 9 and a second insulating material 10, and a second heating element 6
The second heat generating plate 11 is wrapped with an auxiliary heat generating wire 12 having a smaller electric power than the first main heat generating wire 8, and is covered with third insulating material 13 above and below.
and a fourth insulating material 14.

The first insulating material 9, the first heating plate 7, and the second insulating material 1
0 and the heat diffusion plate 4 have a hole a15.0 in the center. b16°C17,
d18, the third insulating material 13 and the second heating board 1
1 and the fourth insulating material 14 have the hole a16. b16
．． c17. Hole e19, 120 larger than d18. g2
1 and 9 having a central portion protruding upward;
It has an outer peripheral side part 22c and a through hole in the center, and the hole a1
s,b1e.

017, d18 and hole e19. f20. The heat exchanger plate 1 is made of a first backing material 22 with good thermal conductivity such as a surface-treated steel plate having two stages of holding surfaces 22a and 22b corresponding to
It is attached with a presser foot provided on the underside.

By configuring as described above, the flow from the first heat generating plate 7 to the first back plate 2 passes through the second insulating material 10 and the heat diffusion plate 4.
2, and from the first back plate 22 to the sensor detection surface 1b provided at the center of the bottom surface, during boiling and empty cooking.

Heat conduction to the sensor detection part 1b is improved, and more accurate detection can be achieved, and reliability and safety can be further improved.

Effects of the Invention As described above, in the heating element of the present invention, the first heating panel and the first and second insulating materials are located in the center of the second heating panel and the third and fourth insulating materials. A hole larger than the hole provided in the center of the heat diffusion plate is provided, and a two-step presser surface is provided on the first back plate to correspond to the hole, ensuring durability and ensuring durability. Heat conduction from the heating element and radiant heat to the sensor detection part is good, and dry cooking detection performance can be improved. In addition, since the diameters of the holes provided in the center of the heating panel and insulating material are different, it is possible to prevent mistakes in assembling parts, and improve assembly efficiency, safety, and reliability.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of the present invention.
The figure is an exploded perspective view of an electric heating element, Figures 2 and 3 are a sectional view and an enlarged sectional view of a main part of an electric water heater equipped with a heating element, and Figure 4 is an exploded perspective view of a conventional electric heating element. It is a diagram. 1--Heat transfer plate, 4--Heat diffusion plate, 7--
・-・First heat generating board, 9・・・First insulating material, 10・
...Second insulating material, 11...Second heat generating board, 13...-Third insulating material, 14...Fourth insulating material, 16... ...hole a, 16...--one hole b
117... Hole C, 18... Hole d, 19...
...Hole e, 20...Hole f121...---
One hole q, 22...First back plate, 22a...
--- Presser surface a, 22b--- Presser surface, 23.
・－・・・Container. Name of agent: Patent attorney Shigetaka Awano and one other person Fu No. 1 Bonryorei 9- No. 19 Insulating material Fig. 2■ Shi-1 j Fig. 3 b Fuku Fig. 4

Claims (1)

[Claims] A first heat generating plate whose upper and lower surfaces are covered with first and second insulating materials is provided on the back side of the bottom of the container which has a bottomed cylindrical shape and has a heat transfer plate protruding from the bottom surface, and from this first heat generating plate. A second heat generating board with low power consumption and whose upper and lower surfaces are covered with third and fourth insulating materials, a heat diffusion plate with good thermal conductivity, and a first back plate are attached, and the second heat generating board is installed. A hole larger than the hole provided in the center of the first heating panel, the first and second insulating materials, and the heat diffusion plate is provided in the center of the board and the third and fourth insulating materials. An electric heating element characterized in that the back plate is provided with two pressing surfaces corresponding to the respective holes.