JPS6228249Y2 - - Google Patents

Description

[Detailed Description of the Invention] Field of the Invention The present invention relates to a heating container, and particularly to a heating container whose contents can be heated by a ceramic heater having a high watt density.

BACKGROUND ART Conventionally, as a heating container, a band heater is attached to the outer periphery of the bottom of a metal container, and the contents are heated by the band heater.
In this type of heating container, mica heaters or sheathed heaters are generally used as heaters, but in either case, the watt density is small;
It has the disadvantage of increasing size and cost.

Therefore, it is conceivable to attach a ceramic heater with a large watt density to the bottom of a metal container, which can obtain large power even with a small size and reduce costs. To attach this type of ceramic heater to the bottom of a container, for example, place a presser spring on the back of the ceramic heater, and support the back of this presser spring with a presser plate screwed to the outer periphery of the bottom of the container. One possible method is to press the heater onto the bottom of the container. However, when the bottom surface is flat, the clamping force of the presser plate causes
There is a problem in that the center of the bottom of the container is depressed through the ceramic heater, and as a result, an unreasonable force is applied to the ceramic heater.

Therefore, we formed multiple concentric steps for reinforcement at the bottom of the container, placed a ceramic heater on the outer surface of the center step, and screwed both ends of the presser plate that supports the presser spring onto the outer circumferential step of the bottom. There are ways to stop them, but in general, containers are made of separate bodies and bottoms that are fixed together by welding. There is a problem that deformation easily occurs. Therefore, when both ends of the presser plate are screwed to the outer periphery of the bottom, the presser plate and the ceramic heater are tilted relative to each other, and the spring pressure of the presser spring does not act evenly on the ceramic heater, causing the ceramic heater and the bottom of the container to There is a problem in that this causes local contact between the ceramic heater and the ceramic heater itself, causing an abnormal temperature rise and cracking of the ceramic heater itself.

Purpose of the invention The present invention was made in view of the above problems, and even if there is residual strain or thermal influence during welding, it can achieve efficient heating by improving heat transfer between the ceramic heater and the bottom of the container. The purpose is to provide a heating container that can be heated.

Structure of the invention In order to achieve the above object, the present invention provides a plurality of concentric steps at the bottom of the container, a ceramic heater is brought into contact with the outer surface of the central step, and a presser spring is arranged on the back of the ceramic heater. The back of the spring is supported by a presser plate screwed to the middle step, and the ceramic heater is pressed against the outer surface of the center step.

Embodiments Next, embodiments of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a stainless steel container which is an example of a metal container, and has a body 2 and a bottom 3, which are separate bodies, welded together at the periphery. In order to reinforce the bottom part, the bottom part 3 is formed with a plurality of concentric step parts 3a to 3c whose central part is depressed in a step-like manner, and the outer surface of the central step part 3a has a predetermined thickness (for example 4 mm) aluminum plate 4 is bonded and fixed. This aluminum plate 4 has one side connected to the container 1.
Pressure and heat are applied to the center step portion 3a of the bottom portion 3 to join and fix them by hot welding such as clad welding, and then the outer surface is polished or cut to obtain flatness.

An intermediate metal plate 5 made of an aluminum plate and a ceramic heater 6 are provided on the outer surface of the aluminum plate 4.
A heater unit 8 is formed by integrally fixing a rear metal plate 7 made of an aluminum plate and a rear metal plate 7 made of an aluminum plate, and is pressed into contact with a substantially disc-shaped presser spring 9 whose back is supported by a presser plate 10. That is, the presser plate 10 is formed into a substantially disk shape, and there are, for example, three holes on the outer periphery.
screw insertion holes 10a are formed;
Three mounting screw seats 11 are fixed to the intermediate stage portion 3b of the container 1 at 120 degree intervals. Then, with the heater unit 8 in contact with the outer surface of the aluminum plate 4 and the presser spring 9 placed on its back, the screw 12 is inserted into the screw insertion hole 10a while pressing the back of the presser spring 9 with the presser plate 10. By screwing the presser plate 10 to the mounting screw seat 11, the heater unit 8 is attached to the aluminum plate 4 with a predetermined pressure.

The ceramic heater 6 is formed by forming a thin ceramic substrate mainly made of alumina in a semi-dry state, printing a circuit consisting of heater wires, a temperature control sensor, etc. on the top surface, and then forming a thin ceramic layer on top of it. was then molded with several thin ceramic layers laminated underneath, and the whole was fired with the lead wires exposed to the outside. Note that the ceramic heater 6 and the metal plates 5, 7 may be fixed integrally as described above, or may be separated.

In the heating container configured as described above, due to residual strain and thermal effects during welding of the body 2 and bottom 3 of the container 1, the outer circumferential step 3c of the bottom 3 is depressed as shown by the broken line in FIG. However, since the parallelism between the central step portion 3a and the intermediate step portion 3b is maintained, the presser plate 10 screwed to the intermediate step portion 3b and the ceramic heater 6 do not tilt relative to each other, and the presser spring The spring pressure 9 acts equally on the ceramic heater 6.
Therefore, even if a dent occurs in the outer circumferential step 3c of the bottom part 3 due to residual strain or thermal effects, the ceramic heater 6 will remain in close contact with the aluminum plate 4 via the intermediate metal plate 5. There is no risk of cracking as it does not cause abnormal temperature rise.

The internal solution stored in the container 1 is transferred to an intermediate metal plate 5 and an aluminum plate 4 by a ceramic heater 6.
and the bottom part 3. At this time, the intermediate metal plate 5 and the aluminum plate 4 have good thermal conductivity, and the aluminum plate 4 and the intermediate metal plate 5
Since they are in close contact with each other by the spring force of the presser spring 9, the heat transfer properties are extremely good. In addition, even if there is distortion in the bottom part 3 due to pressing, welding, etc. during the formation of the container 1 or distortion in the joining and fixing of the aluminum plate 4, the above-mentioned distortion can be ignored by plane-polishing or cutting the outer surface of the aluminum plate 4 later. flatness is obtained, and the adhesion between the intermediate metal plate and the aluminum plate is not impaired.

Furthermore, when the remaining amount of the solution kept at a predetermined temperature (for example, 90°C) becomes low, when cold water is replenished into the container 1, the bottom 3 of the container 1 is rapidly cooled due to the cold water, and the ceramic heater There is a risk of giving a heat shock to 6. However, since the aluminum plate 4 and the intermediate metal plate 5 are interposed between the bottom part 3 and the ceramic heater 6, the thermal shock is softened by the heat capacity of the aluminum plate and the intermediate metal plate, and the ceramic heater 6 cracks can be prevented.

Furthermore, during normal heating, the upper surface of the bottom 3 of the container 1 is lower than the lower surface of the aluminum plate 4, which receives heat from the ceramic heater 6, so the bottom 3 and the aluminum plate 4 are arranged so that the bottom is convex. On the other hand, since the container 1 is overheated during empty cooking, there is a tendency for the container 1 to sag inward so that the bottom becomes concave. If the ceramic heater 6 is the aluminum plate 4
If the ceramic heater 6 and the aluminum plate 4 are in direct contact with each other, the ceramic heater 6 and the aluminum plate 4 will come into local contact during the above-mentioned external sagging and internal sagging, and the heat of the ceramic heater 6 will not be sufficiently transferred to the aluminum plate 4. As a result, there is a problem in that the ceramic heater 6 itself causes an abnormal temperature rise and breaks.
However, since an intermediate metal plate 5 is interposed between the ceramic heater 6 and the aluminum plate 4, and this intermediate metal plate 5 is in surface contact with the ceramic heater 6 regardless of the deformation of the aluminum plate 4, the intermediate metal plate 5 The heat of the heater 6 is dissipated by the plate, and cracking of the ceramic heater 6 due to an abnormal temperature rise can be prevented. Furthermore, deformation and distortion of the bottom 3 of the container 1 and the aluminum plate 4 are not transmitted to the ceramic heater 6 due to the interposition of the intermediate metal plate 5, and no bending moment is applied to the ceramic heater 6.

The reason why the back metal plate 7 is provided behind the ceramic heater 6 is to equalize the spring pressure of the presser spring 9 that presses the back of the ceramic heater 6 and to eliminate variations in heater temperature. Since the heater unit 8 is constructed by integrally sandwiching the ceramic heater 6 between the back metal plate 7 and the intermediate metal plate 5, parts management becomes easy and assembly work is also simplified.

Further, the reason why the joint surface between the aluminum plate 4 and the intermediate metal plate 5 was polished and the aluminum plate 4 was bonded and fixed to the bottom part 3 by hot pressure welding is as follows. Generally, the resistance value of the heater wire of the ceramic heater 6 has a property of increasing as the heater temperature rises. If the adhesion between the bottom part 3 and the bottom part 3 is poor, the heat from the ceramic heater 6 will be transferred to the bottom part 3.
The ceramic heater 6 itself will be overheated. In this case, the resistance value of the ceramic heater 6 also increases, and together with the above-mentioned poor heat transfer, the result is that the liquid content is not sufficiently heated considering the power consumption. Therefore, as described above, the bottom part 3, the aluminum plate 4, the intermediate metal plate 5, and the ceramic heater 6 are connected.
By increasing the adhesion with the ceramic heater 6, the temperature rise of the ceramic heater 6 is suppressed, heat is generated efficiently, and the heat transfer coefficient is improved, allowing the small ceramic heater 6 to exhibit a large heating capacity. .

As shown in the drawings, a recess 4a is formed in the center of the outer surface of the aluminum plate 4. This is because the bottom part 3 and the aluminum plate 4 are thermally deformed so as to convex downward during heating, which tends to push the ceramic heater down and cause it to crack or cause poor adhesion.
This is to reduce this influence.

Further, the aluminum plate 4 is not limited to being bonded and fixed to the bottom portion 3 by hot pressure welding as in the above embodiment, but may be bonded and fixed integrally to the outer surface of the bottom portion 3 by die casting, for example. Furthermore, the container according to the present invention is not limited to a single-layered container as in the above embodiment, but may also be a heat-insulated heavy-duty container whose outer circumferential surface is wrapped with a heat insulating material or a vacuum double-layered container. In that case, only the bottom portion may be made single layered and a ceramic heater may be attached to this bottom portion.

Note that the form of welding the body 2 and the bottom 3 of the container 1 is not limited to the one shown in FIG. may be welded to the lower end of the body 2, or as shown in FIG. may be welded to the outer surface of the upright part.

Effects of the Invention As described above, the present invention provides a heating container in which a body and a bottom are separately welded, and a ceramic heater is attached to the outer surface of the central step of the concentric reinforcing step provided at the bottom. Since the ceramic heater is pressed against the outer surface of the center step using a presser spring and a retaining plate screwed to the intermediate step, even if the outer peripheral step at the bottom is not affected by residual strain or thermal effects during welding, Even if a dent occurs, the parallelism between the central step and the intermediate step is maintained, so the presser plate and ceramic heater do not tilt relative to each other, and the spring pressure of the presser spring acts evenly on the ceramic heater. . Therefore, the heat transfer between the ceramic heater and the bottom of the container is improved, and efficient heating is possible, and cracking of the ceramic heater itself due to abnormal heating can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a bottom sectional view of an example of the heating container according to the present invention, and FIGS. 2 and 3 are partial sectional views of other examples of the welded form. DESCRIPTION OF SYMBOLS 1... Metal container, 3... Bottom, 4... Aluminum plate, 5... Intermediate metal plate, 6... Ceramic heater, 7... Back metal plate, 8... Heater unit, 9... Presser spring, , 10... presser plate, 11...
...Mounting screw seat.

Claims (1)

[Scope of utility model claims] In a heating container in which a body and a bottom are made of separate metal plates and these are welded at the periphery, a plurality of concentric steps are formed in the bottom, and a ceramic heater is installed on the outer surface of the central step. A press plate is screwed onto the mounting screw seat formed on the intermediate step, and a press spring is interposed between the press plate and the ceramic heater to press the ceramic heater against the outer surface of the center step at the bottom. A heating container characterized by: