JPH07177981A - Cooking surface of heating cooker and its production - Google Patents

Abstract

PURPOSE:To obtain a cooking plate having excellent wear resistance to prevent peeling of a fluororesin even if a metallic spatula is used for the cooking plate with the fluororesin coated on the surface in the surface treatment structure of the cooking plate to be used for an electromagnetic cooker, etc. CONSTITUTION:A thermally sprayed layer 13 is formed on the surface 12 of a plate 11 without having the rugged shapes of the hot plate. A primer layer 14 and top coat layer 15 of the fluororesin are applied thereon. The rugged parts exist on the surface of the thermally sprayed layer 13 and are specified to Ra=9 to 13mum, Rmax=60 to 110mum and film thickness 30 to 80mum. The plate structure which substantially prevents peeling of the fluororesins in spite of strong rubbing of the cooking surface with the metallic spatula is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking surface structure used in a heating cooker such as a hot plate or an electric pan, which is improved so as to improve wear resistance.

[0002]

2. Description of the Related Art In order to improve wear resistance, the cooking surface structure of a conventional cooking device such as a hot plate or an electric pan is
For example, the configuration as described in Japanese Patent Laid-Open No. 5-23253 is adopted. The details will be described with reference to FIG. 6. Reference numeral 1 is a metal material.
Three thermal spray layers having a thickness of μm are formed. Then, a polysiloxane-based binder of 4 having a thickness of 10 ± 5 μm is provided on the sprayed layer 3, and 10 to 30 thereon.
Five fluororesin layers having a thickness of μm are provided. Further, the surface of the fluororesin layer 5 has 6 convex portions.

In the above cooking surface structure, when the cooking surface is rubbed with a metal spatula, the projections 6 of the fluororesin layer 5 and the projections 7 of the polysiloxane binder 4 are slightly peeled off. However, the sprayed layer 3 is harder than the polysiloxane-based binder 4 and the fluororesin layer 5, and the projection 8 of the sprayed layer 3 is not broken by the metal spatula, whereby the projection 8 of the sprayed layer 3 is broken.
In order to support the abrasion of the metal spatula, the fluororesin layer 5 is suppressed in a state of being slightly peeled off, and the scorching caused by the peeling of the fluororesin can be prevented. Therefore, it was possible to cook deliciously using a metal spatula.

[0004]

However, when the cooking surface is strongly rubbed with a metal spatula, the projections of the fluororesin layer and the polysiloxane-based binder are peeled off, and the projections of the sprayed layer also collapse, so that the fluororesin is spread over a wide range. The problem of peeling occurred. As a result, there was a problem that charring occurred in the portion without the fluororesin during cooking, and cooking could not be performed well.

Therefore, it is an object of the present invention to develop a thermal sprayed layer having a hardness such that the convex portion of the thermal sprayed layer does not collapse even if it is strongly rubbed by a metal spatula and a large load is applied to the cooking surface.

[0006]

In order to achieve the above object, the first means of the present invention is that the surface of a cooking plate has a roughness R.
a = 5 μm or less, a base material of a metal material having a shape in which no irregularities are formed, and a sprayed layer provided on the surface of the base material,
In a cooking plate in a heating cooking period in which a fluororesin is applied and baked on the sprayed layer, the sprayed layer has a thickness of 30 to 80 μm.
m, the surface roughness of the sprayed layer is Ra = 9 to 13 μm, Rma
x = 60 to 110 μm, and the sprayed material is a mixture of alumina-titania ceramics and nickel-aluminum alloy, or a material prepared by compression molding and sintering of alumina-titania ceramics and nickel-aluminum alloy on the cooking surface. is there.

The second means is that the particle size of the thermal spray material is 50 to 50.
It is a cooking surface of a heating cooker using a material having a particle size combination of 110 μm and particle sizes of 50 to 75 μm and 75 to 110 μm in a ratio of 3: 7.

A third means is a method for manufacturing a cooking surface of a heating cooker in which the arc gas is set to 40 psi or less, the electric current is set to 850 A or more, and the powder gas is set to 50 psi or more when spraying and depositing the sprayed material. It was done.

[0009]

With the configuration of the first means described above, Ra = 5
The thickness is 30 to 80 μm and the surface roughness is Ra = 9 to 13 μm on the surface of the metal material having an unevenness of less than μm.
A thermal sprayed layer having Rmax = 60 to 110 μm is provided. As a result, the surface of the sprayed layer becomes uneven like the surface of the sprayed layer having the conventional structure, and when the fluororesin is applied onto the sprayed layer, the surface of the fluororesin becomes uneven as in the conventional case. Then, when the cooking surface is rubbed with a metal spatula, the projections on the surface of the fluororesin layer are peeled off and the metal spatula hits the projections on the surface of the sprayed layer in the structure of the present invention as in the conventional structure. Here, since the surface shape of the conventional sprayed layer is formed by applying a predetermined thickness on the unevenness formed on the cooking plate surface, the projections on the surface of the sprayed layer are the same as those on the cooking plate surface. Formed in
When the convex portion on the surface of the sprayed layer receives a load from the metal spatula, the convex portion on the surface of the cooking plate is also loaded. On the other hand, in the configuration of the present invention, since the spraying is provided on the surface of the cooking plate having no unevenness, even if a convex portion of the unevenness of the sprayed layer surface receives a load from a metal spatula, the cooking plate surface is not loaded. Hardly receives. Generally, the cooking plate is made of an aluminum alloy having excellent thermal conductivity, but this aluminum alloy has a lower hardness than ceramics, which is a thermal spray material. In the structure, the projections of the sprayed layer collapse from the projections of the cooking plate made of aluminum alloy, and the fluororesin layer peels off in a wide area. On the other hand, the projections of the sprayed layer having the structure of the present invention are hardly affected by the aluminum alloy of the plate base material, and are subjected to the load from the metal spatula in the sprayed layer, so that they do not collapse and the fluororesin hardly peels off.

Further, as the thermal spraying material, not the conventional alumina-titania but a material obtained by mixing the alumina-titania ceramics and the nickel aluminum alloy or a material obtained by compression molding and sintering the alumina-titania ceramics and the nickel aluminum alloy is used. Since the nickel-aluminum alloy improves the bonding force between the particles during thermal spray deposition, the shape of the convex portion formed on the surface of the thermal spray layer becomes tough, and even if the cooking surface is rubbed by the metal spatula, it is less likely to collapse.

As described above, according to the structure of the present invention, even if the surface of the cooking plate is strongly rubbed with the metal spatula, the peeling of the fluororesin is suppressed to a minimum, no sticking occurs during cooking, and a long-life and delicious cooking is possible. A cooking period having a face can be provided.

The structure of the second means, that is, the particle size of the thermal spray material is changed from the fine particle size of the conventional product to a large particle size of 50 to 110 μm, and the particle size composition of the particle size is 50 to 75 μm.
m and the particle size of 75 to 110 μm are mixed in the ratio of 3: 7, the density of the thermal spray material is the highest, the density is high even when sprayed and adhered, the bonding force between the particles becomes high, and the hardness of the thermal spray layer is high. Is obtained.

In the third means, that is, when the thermal spraying is applied,
By lowering the arc gas and increasing the current and powder gas, it is possible to form a sprayed layer having the constitution of the present invention even with a sprayed material having a large particle size, which has been difficult to spray and deposit until now.

To explain this principle, first, by lowering the arc gas, the sprayed material stays in the frame for a longer time, and the material is easily melted. Next, increasing the electric current increases the flame power of the frame, and the material is easily melted. As a result, a material having a large particle size, which has been difficult to melt and could not be spray-adhered, can be spray-adhered. Also, by increasing the powder gas, the amount sent into the frame increases, and the sprayed layer with the target film thickness can be obtained in one stroke, and it is possible to work in a short time and to form a layer with several overcoatings. It is possible to obtain a sprayed layer having high adhesion, while the adhesion to the layer is reduced.

[0015]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a plate of a hot plate showing a first embodiment, FIG. 2 is a partially enlarged view of a cooking surface of the plate 1 of FIG. 1, and 11 in FIGS. 1 and 2 is a hot plate. 12 is a surface to be a cooking surface of the plate 11, and 13 sprayed layers are formed on the surface 12 of the plate 11. Then, 14 primer layers of fluororesin and 15 top coats are applied onto the sprayed layer 13. Reference numeral 16 is an uneven portion of the sprayed layer, 17 is a protruding portion of the primer layer 14, and 18 is a protruding portion of the top coat 15.

Next, a method of manufacturing the cooking surface structure having the above structure will be described with reference to FIGS. 1 and 2.

First, the plate 11 is manufactured by die casting of an aluminum alloy, and the surface 12 serving as a cooking surface is formed to have no uneven shape. And air pressure 5 on the surface 12
Sandblasting at ~ 7Kg / cm ² for about 3 minutes (# 3
6, alumina oxide) is applied to roughen the surface 12. Here, the surface is roughened by blasting, but this is for cleaning the surface 12 of the plate 11, and the surface 12 of the plate 11 does not have irregularities. Then, a thermal spraying material is sprayed on the surface 12 of the plate 11 by using a plasma spraying device to provide a thermal spray layer 13. Examples of the spray material in place of a conventional Al ₂ O ₃ spray material over 2.3% TiO _2, Al ₂
The distance between the gun of the plasma apparatus and the surface 12 of the plate 11 is set to about 10 cm by using a material in which 91% of O ₃ is mixed with 4% of TiO _{2 and} 5% of NiAl. The thickness of the sprayed layer is 30 to 80 μm, and the roughness of the peaks 16 is Ra = 9 to 13
μm, Rmax = 60 to 110 μm. Next, a fluororesin primer layer 14 having a film thickness of 10 ±
After being applied to 5 μm and pre-dried at 120 to 150 ° C. for 10 minutes, a fluororesin top coat 15 having a film thickness of 20 ± 1
A coating of 0 μm is applied, preliminary drying is performed at 120 to 150 ° C. for 10 minutes, and baking is performed at 380 ° C. for 20 minutes.

In the plate structure thus constructed,
The uneven shape of the sprayed layer is not formed by the uneven shape provided on the surface of the plate as in the conventional configuration, but the surface 12
Since the uneven sprayed layer 13 is provided on the plate 11 which is not provided with the uneven shape on the plate 11, when the cooking surface is rubbed with the tip of the metal spatula 19 as shown in FIG. 18 and the convex portion 1 of the primer 14
7 is peeled off and the metal spatula 19 is a convex portion 1 on the surface of the sprayed layer 13.
6, the protrusions 16 of the thermal spray layer 13 have a higher impact resistance than the protrusions of the conventional thermal spray layer, and therefore are less likely to collapse.

Further, the thermal spray material is Al ₂ O ₃ 91%, TiO 2.
_By using a material in which 24% and NiAl 5% are mixed, the bonding force between particles is improved at the time of thermal spray adhesion, and the projections 23 of the thermal spray layer 22 are less likely to collapse.

On the other hand, the projections of the conventional sprayed layer are affected by the unevenness of the plate. Generally, the material of the plate is an aluminum alloy having excellent thermal conductivity, and the hardness of the aluminum alloy is significantly higher than that of the sprayed ceramics. Because of inferiority, the projections of the sprayed layer are more likely to collapse than the projections 16 of the sprayed layer 13 having the configuration of the present invention.

Therefore, in the plate of the present invention, since the projections 16 of the thermal spray layer 13 are not peeled off, the peeling of the top coat 15 can be suppressed to a small extent. Peeling occurs in a large area.

As described above, according to the structure of the present invention, even if the surface of the cooking plate is strongly rubbed with the metal spatula, the peeling of the fluororesin is suppressed to a minimum, no sticking occurs during cooking, and a long-life and delicious cooking is possible. A cooking period having a face can be provided.

(Embodiment 2) As shown in FIG. 4, the surface 21 of the plate 20 is formed into a shape without unevenness by the same manufacturing method as in Embodiment 1, and the surface 21 is subjected to sandblasting and then plasma sprayed. Using the equipment, change the particle size of the thermal spray material from the conventional fine material of 10 to 45 μm to 50 to 1
By changing to a large particle size of 10 μm and changing the particle size composition of the particle size to a ratio of 50 to 75 μm and 75 to 110 μm in the ratio of 3: 7, the density of the thermal spraying material became the highest and the thermal spraying was performed. Sometimes the density is high,
Twenty-two sprayed layers with improved adhesion are obtained, and the projections 23 of the sprayed layer 22 have hardness. Therefore, 24 primer layers of fluororesin and 25 top coats to be applied on the sprayed layer 22 are applied, but even if the surface of the plate is abraded by the metal spatula of 26, the fluororesin is hardly peeled off. You can get a non-stick cooking surface.

(Embodiment 3) As shown in FIG. 5, by the same manufacturing method as in Embodiment 1, the surface 31 of the plate 30 is made into a shape without irregularities, and the surface 31 is subjected to sandblasting and then plasma sprayed. The apparatus is used to provide 32 thermal spray layers, and the manufacturing conditions at this time are as low as 40 psi for the arc gas to prolong the time the thermal spray material stays in the frame, making it easier to melt the thermal spray material. The current is increased to 1000 A to increase the heating power and facilitate the melting of the thermal spray material.

The Aux gas is 100 psi. In addition, the powder gas can be raised to 50 psi to increase the amount of thermal spray material entering the frame and be applied thicker. Under the above conditions, Ra = 9 to 13 μm, Rm for materials with large grain size
A sprayed layer having ax = 60 to 110 μm and a film thickness of 30 to 80 μm can be provided.

[0027]

As is clear from the above description, in the present invention, even if the cooking surface is strongly rubbed with the metal spatula, the fluororesin is hardly peeled off, so that there is no sticking during cooking and long-life cooking is possible. A heating cooker having a plate can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of a plate of a hot plate showing a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a plate of the hot plate.

FIG. 3 is an enlarged sectional view of a cooking surface showing a usage state of a metal spatula according to the first embodiment of the present invention.

FIG. 4 is a sectional view of a plate of a hot plate showing a second embodiment of the present invention.

FIG. 5 is a sectional view of a plate of a hot plate showing a third embodiment of the present invention.

FIG. 6 is an enlarged sectional view of a cooking surface structure showing a conventional heating cooker.

[Explanation of symbols]

 11, 20, 30 Plates 13, 22, 32 Sprayed layer 14, 24 Primer layer 15, 25 Top coat 16, 23 Topographically convex portion of sprayed layer 17 Primed portion of primer layer 18 Topcoat raised portion 19, 26 Metal spatula

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsuneo Shibata 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Hidenori Kawanishi, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Atsushi Atsue 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. The surface of the cooking plate has a roughness of Ra = 5 μm.
A base material of a metal material having a shape in which no unevenness is formed below, a sprayed layer provided on the surface of the base material, and a cooking process in which the fluororesin is applied on the sprayed layer and baked. In the plate, the sprayed layer has a film thickness of 30 to 80 μm, and the surface roughness of the sprayed layer is Ra = 9 to 13 μm and Rmax = 60 to
110 μm, the cooking surface of a heating cooker using a material obtained by mixing alumina-titania ceramics and nickel aluminum alloy or a material obtained by compression molding and sintering alumina-titania ceramics and nickel aluminum alloy as the thermal spray material. 2. The thermal spray material has a particle size of 50 to 110 μm.
2. The cooking surface of the heating cooker according to claim 1, wherein a material having a particle size mixture of 50 to 75 μm and 75 to 110 μm in a ratio of 3: 7 is used. 3. A method for manufacturing a cooking surface of a heating cooker, wherein when spraying and depositing a spraying material, the spraying conditions are arc gas of 40 psi or less, electric current of 850 A or more, and powder gas of 50 psi or more.