JP4169850B2 - Induction cooker pan - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pan, particularly a frying pan, that can be suitably used for an electromagnetic cooker.
[0002]
[Prior art]
In recent years, an electromagnetic cooker has attracted attention as an electric heating apparatus capable of rapid heating. The electromagnetic cooker is a heating method in which the bottom of a pan placed on the electromagnetic cooker is induction-heated by electromagnetic induction and the pan bottom itself is used as a heater. Therefore, iron or an iron alloy is used for the material of the pan. Since the bottom portion of the pan for an electromagnetic cooker is rapidly heated, it is likely to be thermally deformed and sometimes bulges downward. In this case, since the pan cannot be stably placed on the electromagnetic cooker, it becomes difficult to use the pan. For this reason, conventionally, measures have been taken to prevent thermal deformation of the pan by forming a plurality of annular cutting grooves concentrically on the bottom of the pan.
[0003]
[Problems to be solved by the invention]
As described above, since a plurality of annular cutting grooves are formed at the bottom of a conventional pan for an electromagnetic cooker made of iron or an iron alloy, it is necessary to increase the plate thickness by the depth of the annular cutting grooves, There is a problem that the weight of the pan increases. For this reason, attempts have been made to reduce the weight of the pot by using a laminated plate of different metals, for example, a laminated plate of an aluminum plate and a stainless steel plate as the material of the pan. In this case, if the stainless steel plate of the laminated plate is arranged on the outer layer side of the pan and the annular cutting groove is formed on the bottom surface of the outer layer side of the pan, the plate thickness of the stainless steel plate is reduced by cutting, so the output of the electromagnetic cooker There is a problem that decreases.
[0004]
As a result of intensive research on such problems, the present inventors have formed the above-mentioned problem by forming a plurality of annular forming grooves at an appropriate depth in place of the annular cutting grooves at the bottom of the pan as described later. It has been found that not only can the output of the electromagnetic cooker be prevented but also the output can be improved.
[0005]
The present invention has been completed based on this finding, and an object of the present invention is to provide a lightweight pan for an electromagnetic cooker that can prevent thermal deformation of the bottom of the pan and improve the output of the electromagnetic cooker. It is to be.
[0006]
[Means for Solving the Problems]
The present invention has a bottom portion that extends flat and a side wall portion that extends substantially perpendicular to the bottom portion, and is placed on an electromagnetic cooker and induction heated by electromagnetic induction.
An aluminum plate and a stainless steel plate that is thinner than the aluminum plate are composed of laminated plates that are pressed in layers,
Stainless steel plates are arranged on the outer layer side of the bottom and side walls,
On the bottom surface on the outer layer side of the bottom part, a plurality of annular molding grooves are formed by pressing concentrically around the center part of the bottom surface ,
The ratio D / t between the depth D of each annular forming groove and the thickness t of the stainless steel plate is selected to be in the range of 1.0 ≦ D / t ≦ 2.5,
The plate thickness t is selected in the range of 0.4 mm to 1.0 mm,
The plurality of annular forming grooves are concentrically formed around the center of the bottom surface in a diameter range of 60 mm to 120 mm,
The thickness of the said aluminum plate is chosen as the value of the range of 1.3 mm-2.6 mm, It is a pan for electromagnetic cookers characterized by the above-mentioned.
[0007]
According to the present invention, a plurality of annular forming grooves are formed concentrically on the bottom surface of the flat outer layer side of the bottom of the pan for the electromagnetic cooker, so that the heat deformation of the bottom of the pan is evenly absorbed without unevenness. can do. Further, since the ratio D / t between the depth D of each annular forming groove and the plate thickness t of the stainless steel plate is selected within a proper range, the ability to absorb thermal deformation can be improved. As shown in FIG. 14, the amount of thermal deformation at the bottom of the pan can be reduced. Furthermore, the output of the electromagnetic cooker can be improved as shown in FIGS.
Moreover, since the outer layer of the pan for electromagnetic cookers is a stainless steel plate and the inner layer is an aluminum plate, the pan can be reduced in weight. Moreover, since the aluminum plate with favorable thermal conductivity is disposed in the inner layer of the pan, the temperature distribution at the bottom of the pan can be made uniform. Moreover, since the stainless steel plate is arrange | positioned in the outer layer of the said pan, the corrosion resistance and heat resistance of a pan can be improved.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view showing a simplified configuration of a pan for an electromagnetic cooker according to a first embodiment of the present invention, FIG. 2 is a bottom view as seen from II-II in FIG. 1, and FIG. It is sectional drawing seen from the cut surface line III-III of FIG. The frying pan 1 which is the pan for the electromagnetic cooking device in FIG. 1 is shown with the bottom portion facing upward for convenience of illustration. The frying pan 1 is heated by placing the bottom on an electromagnetic cooker. The electromagnetic cooker applies high-frequency alternating current to a heating coil inside the appliance, induces eddy current due to electromagnetic induction at the bottom 3 of the frying pan 1, and induction-heats the bottom 3 using Joule heat of eddy current.
[0011]
Frying pan 1 of the present embodiment is a laminated plate of a non-ferrous metal plate and an iron or iron alloy plate, for example, an aluminum plate 6 that is a non-ferrous metal plate, and an iron or iron alloy plate that is thinner than aluminum plate 6. It consists of a laminated plate with a stainless steel plate 7 and is formed by pressing. The frying pan 1 is formed by setting the laminated plate in a mold so that the stainless steel plate 7 is on the outer layer side. The laminated plate cleans the joining surfaces of the aluminum plate 6 and the stainless steel plate 7, superimposes the joining surfaces and cold-rolls them, brings both metals close to the interatomic distance, presses them in layers, and further heats them. It is manufactured by interdiffusion of atoms and metal bonding of both metals.
[0012]
The frying pan 1 includes a disk-shaped bottom portion 3 that extends substantially flat, a cylindrical side wall portion 4 that extends substantially perpendicularly to the bottom portion 3, and a handle 5 that is fixed to the side wall portion 4. A stainless steel plate 7 is disposed on the outer layer side of the bottom portion 3 and the side wall portion 4 of the frying pan 1, and an aluminum plate 6 is disposed on the inner layer side. On the outer layer side bottom surface 14 of the bottom portion 3 of the frying pan 1, a plurality (3 in the present embodiment) of annular molding grooves 9 are formed concentrically around the central portion C of the bottom surface 14. The cross-sectional shape of the annular forming groove 9 is substantially semicircular. The outer diameter and groove width of the annular forming groove 9 are set to predetermined values. The outer diameters D1, D2, and D3 of each annular forming groove 9 are, for example, 83 mm, 103 mm, and 123 mm, respectively, and the groove width W of each annular forming groove 9 is, for example, 3.0 mm. The ratio D / t between the depth D of each annular forming groove 9 and the plate thickness t of the stainless steel plate 7 is selected to be in the range of 1.0 ≦ D / t ≦ 2.5. The reason for this limitation will be described later.
[0013]
The thickness of the stainless steel plate 7 that forms the outer layer of the frying pan 1 is, for example, 0.4 to 1.0 mm, and the thickness of the aluminum plate 6 that forms the inner layer of the frying pan 1 is, for example, 1.3 to 2.6 mm. is there. The reason why the upper and lower limits of the thickness of the stainless steel plate 7 are limited in this way is as follows.
[0014]
FIG. 4 is a graph showing the relationship between the thickness of the stainless steel plate 7 forming the outer layer of the frying pan 1 and the output of the electromagnetic cooker, and FIG. 5 is a plan view for explaining a method of measuring the output of the electromagnetic cooker 17. It is. The data shown in FIG. 4 is obtained using a plurality of frying pans 1 having different thicknesses of the stainless steel plate 7. The plate thickness of the plurality of frying pans 1 is 1.7 mm, and the plate thickness of the stainless steel plate 7 is 0.1 to 1.0 mm. Therefore, the plate thickness composition ratio of the aluminum plate 6 and the stainless steel plate 7 of each frying pan 1 is different. In the plurality of frying pans 1 in FIG. 4, the annular forming groove 9 is not formed. The output of the electromagnetic cooker 17 is measured by preparing the plurality of frying pans 1 and the 1.2 kW electromagnetic cooker 17, placing the frying pan 1 on the electromagnetic cooker 17 as shown in FIG. Is set to full output and heated, and the value of the digital output meter 18 is read when the temperature of the central portion C at the inner layer side bottom surface 15 of the bottom 3 of the frying pan 1 reaches 200 ° C.
[0015]
From FIG. 4, it can be seen that the output of the electromagnetic cooker 17 increases as the plate thickness of the stainless steel plate 7 increases, reaches a maximum value when saturated at a plate thickness of 0.4 mm. As described above, the lower limit value of the thickness of the stainless steel plate 7 is limited to 0.4 mm for this reason. The upper limit of the thickness of the stainless steel plate 7 is limited to 1.0 mm. If the plate thickness exceeds 1.0 mm, not only the output cannot be increased, but also the weight increases to reduce the weight. It is because it becomes impossible.
[0016]
FIG. 6 is a cross-sectional view showing a situation during molding of the three annular molding grooves 9, and FIG. 7 is a graph showing the relationship between the groove depth D of the annular molding grooves and the molding force. The three annular forming grooves 9 are formed by pressing. The press working is performed using an upper mold 12 and a lower mold 11 having three annular protrusions 10 as shown in FIG. The plate thickness configuration of the frying pan 1 used for obtaining the data shown in FIG. 7 is an aluminum plate: 2.0 mm and a stainless steel plate: 1.0 mm. The dimensions of each annular projection 10 of the lower mold 11 are the height of the projection. The thickness is 2.0 mm and the protrusion width is 3.0 mm. The outer diameter of each annular protrusion 10 is substantially the same as the outer diameter of each annular forming groove 9. The black circles in FIG. 7 are symbols representing data when the three annular forming grooves 9 are formed. Further, in FIG. 7, data for forming seven annular forming grooves 25 described later are also shown by black triangle marks for comparison.
[0017]
From FIG. 7, there is a unique relationship between the groove depth of the annular forming grooves 9 and 25 and the forming force, and the groove depth of the annular forming grooves 9 and 25 increases as the forming force increases. Comparing the forming force of the three annular forming grooves 9 with the forming force of the seven annular forming grooves 25, seven requires a larger forming force to obtain the same groove depth than the three. I understand that. FIG. 7 is obtained in advance before the annular forming grooves 9 and 25 are formed.
[0018]
As shown in FIG. 6, the three annular molding grooves 9 are formed by placing the outer layer side bottom surface 14 of the bottom 3 of the frying pan 1 on the lower mold 11 having the annular projections 10 and having a flat pressing surface. This is performed by pressing the mold 12 against the bottom surface 15 on the inner layer side of the bottom 3 of the frying pan 1. As a result, three annular forming grooves 9 are formed on the outer layer side bottom surface 14 of the bottom 3 of the frying pan 1 as shown in FIG. Along with this, although minute protrusions are produced on the inner layer side bottom surface 15 of the bottom 3 of the frying pan 1, the minute protrusions are smoothed by polishing. The adjustment of the groove depth D of the three annular forming grooves 9 is to obtain the forming force for the desired groove depth D based on the relationship between the forming force and the groove depth D as shown by the black circles in FIG. This is done by applying the determined molding force to the upper mold 12.
[0019]
As described above, the ratio D / t between the groove depth D of each annular forming groove 9 and the plate thickness t of the stainless steel plate 7 is selected in the range of 1.0 ≦ D / t ≦ 2.5. The reason why the upper and lower limit values of the ratio D / t are limited in this way is as follows.
[0020]
FIG. 8 is a graph showing the relationship between the ratio D / t of the groove depth D of the three annular forming grooves 9 and the plate thickness t of the stainless steel plate 7 and the amount of thermal deformation of the frying pan 1. FIG. 10 is a graph showing the relationship between the ratio D / t between the groove depth D of the annular formed groove 9 and the plate thickness t of the stainless steel plate 7 and the output of the electromagnetic cooker 17. It is a front view for demonstrating the measuring method of quantity, FIG. 11: is a top view for demonstrating the measuring method of the amount of thermal deformation of the frying pan 1. FIG.
[0021]
The amount of thermal deformation of the frying pan 1 is performed using the dial depth gauge 20 and the support member 21. The support member 21 is an elongated rod-shaped member having a rectangular cross section, and supports the dial depth gauge 20 at a substantially central portion in the longitudinal direction. The support member 21 is stretched over the upper portion of the side wall portion 4 of the frying pan 1 and forms one diameter line of a circle formed by the side wall portion 4. Therefore, the support member 21 exists above the center portion C on the inner layer side bottom surface 15 of the bottom portion 3 of the frying pan 1. As shown in FIG. 10, the dial depth gauge 20 is a distance between the lower surface 21 a of the support member 21 at the center C of the inner layer side bottom surface 15 of the bottom portion 3 of the frying pan 1 and the inner layer side bottom surface 15 of the bottom portion 3 of the frying pan 1. And called H). The measurement of the amount of thermal deformation is performed in each of the rolling direction (hereinafter referred to as the L direction) of the laminated plate that is the material of the frying pan 1 and the direction perpendicular to the rolling direction (hereinafter referred to as the C direction). . The amount of thermal deformation is measured when the temperature of the central portion C at the inner layer side bottom surface 15 of the bottom 3 of the frying pan 1 reaches 200 ° C. (hereinafter referred to as after heating) and after cooling to room temperature (hereinafter referred to as “after heating”). In each case).
[0022]
The measurement of the amount of thermal deformation after heating in the L direction and after cooling is performed as follows.
(1) As shown in FIG. 11, the support member 21 is placed on the diameter line 23 parallel to the L direction of the side wall portion 4.
(2) Measure the spacing H before heating, after heating and after cooling. Hereinafter, the measured intervals are referred to as HLO, HL1, and HL2, respectively.
(3) The thermal deformation amounts DL1 and DL2 after heating and cooling are calculated based on the following formulas (1) and (2).
DL1 = HL1-HLO (1)
DL2 = HL2-HLO (2)
[0023]
The measurement of the amount of thermal deformation after heating and cooling in the C direction is performed in the case of the L direction after the support member 21 is placed on the diameter line 24 parallel to the C direction of the side wall portion 4 as shown in FIG. This is done in the same way. The amount of thermal deformation DC1 and DC2 after heating in the C direction and after cooling is the measured interval H before heating, after heating and after cooling (hereinafter referred to as HCO, HC1 and HC2, respectively) (3), It is obtained by substituting into equation (4).
DC1 = HC1-HCO (3)
DC2 = HC2-HCO (4)
[0024]
Accordingly, if the values of the heat deformation amounts DL1, DL2, DC1, and DC2 are positive, it indicates that the bottom 3 of the frying pan 1 is thermally deformed downward, and if it is negative, it is convex upward. Represents thermal deformation.
[0025]
The plate thickness configuration of the frying pan 1 used to obtain the data shown in FIGS. 8 and 9 is aluminum plate: 1.3 mm, stainless steel plate: 0.4 mm, and the outer diameter of the frying pan 1 is 246 mm. The dimensions of the annular forming groove 9 are groove width: 3.0 mm, groove depth D: 0 to 0.73 mm, outer diameter D1: 83 mm, outer diameter D2: 103 mm, and outer diameter D3: 123 mm. The white circles in FIG. 8 are symbols representing the amount of thermal deformation after heating, and the black circles are symbols representing the amount of thermal deformation after cooling. FIG. 8 (1) is a graph showing the relationship between the amount of thermal deformation in the L direction and the ratio D / t, and FIG. 8 (2) shows the relationship between the amount of thermal deformation in the C direction and the ratio D / t. FIG. 8 (3) is a graph showing the relationship between the average amount of thermal deformation in the L direction and the C direction and the ratio D / t. The output of the electromagnetic cooker 17 in FIG. 9 was measured by the measuring method shown in FIG.
[0026]
From FIG. 8, the amount of thermal deformation of the bottom 3 of the frying pan 1 decreases as the ratio D / t increases, and this tendency is the average of the L direction, the C direction, and the L direction and the C direction after heating and cooling. It can be seen that the amounts of thermal deformation in are almost the same. In addition, when the ratio D / t is 1.0 or more, in other words, when the groove depth D of the annular forming groove 9 is equal to or greater than the plate thickness t of the stainless steel plate, the ratio D / t is zero for each amount of thermal deformation. It can be seen that the amount of thermal deformation is maintained at substantially the same level even when the ratio D / t is further increased. This is because as the ratio D / t is increased, the heat distortion absorbing ability by the annular groove 9 is improved, and when the ratio D / t is 1.0 or more, the heat distortion absorbing capacity is saturated.
[0027]
From FIG. 9, the output of the electromagnetic cooker 17 increases as the ratio D / t increases, and when the ratio D / t that satisfies the conditions of the present embodiment is 1.0 or more, a high output of 1.0 kW or more is obtained. It can be seen that it can be obtained stably. On the other hand, when D / t is zero, in other words, when the annular forming groove 9 is not formed, the output is 0.9 kW, which is lower than that of the present embodiment. Further, according to the investigation by the present inventors, an electromagnetic cooker in the case where an annular cutting groove (depth: 1 mm, width: 1 mm, number: 1, diameter: 150 mm) is formed in a frying pan made of a single stainless steel plate. The output is 0.9 kW, which is lower than that of the present embodiment.
[0028]
As described above, the lower limit of the ratio D / t is limited to 1.0 or more for this reason. Further, the upper limit value of the ratio D / t is limited to 2.5 or less because even when the ratio D / t exceeds 2.5, the amount of thermal deformation is further reduced and the output of the electromagnetic cooker 17 is increased. When the ratio D / t exceeds 2.5, the groove depth D of the annular forming groove 9 increases, so that the necessary forming force increases as shown in FIG. It is because it is necessary to make it.
[0029]
As described above, in the present embodiment, the three annular molding grooves are formed concentrically around the center portion C of the bottom surface 14 on the bottom surface 14 of the bottom layer 3 of the frying pan 1. The thermal deformation of the bottom 3 can be absorbed evenly. Moreover, since the ratio D / t is set to a value within an appropriate range, the amount of thermal deformation of the bottom 3 can be reduced, and the output of the electromagnetic cooker 17 can be improved. Therefore, the life of the frying pan 1 can be extended and the cooking heating time can be shortened. Further, since an aluminum plate that is light and has good thermal conductivity is disposed on the inner layer side of the frying pan 1, the frying pan 1 can be reduced in weight and the temperature distribution of the bottom 3 of the frying pan 1 can be made uniform. Moreover, since the stainless steel plate 7 is disposed on the outer layer side of the frying pan 1, the frying pan 1 can be induction-heated by electromagnetic induction, and the corrosion resistance and heat resistance of the frying pan 1 can be improved.
[0030]
FIG. 12 is a bottom view showing a simplified configuration of the bottom 3 of the frying pan 1 according to the second embodiment of the present invention. Since the present embodiment is similar to the first embodiment, the corresponding parts are denoted by the same reference numerals, and duplicate descriptions are omitted. What should be noted in the present embodiment is that seven annular molding grooves 25 are formed on the bottom surface 14 on the outer layer side of the bottom 3 of the frying pan 1. Each annular forming groove 25 is formed concentrically around the central portion C of the outer layer side bottom surface 14. The outer diameter and groove width of each annular forming groove 25 are set to predetermined values. The outer diameters D4, D5, D6, D7, D8, D9, and D10 of each annular molded groove 25 are, for example, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, and 120 mm, respectively. For example, all are 3.0 mm.
[0031]
FIG. 13 is a cross-sectional view showing the situation when the seven annular forming grooves 25 are formed. The seven annular molding grooves 25 are formed by placing the outer layer side bottom surface 14 of the bottom 3 of the frying pan 1 on a lower mold 27 having seven annular projections 26 as shown in FIG. This is performed by pressing the upper mold 12 having the above to the inner layer side bottom surface 15 of the bottom 3 of the frying pan 1. As with the first embodiment, the adjustment of the groove depth D of the annular forming groove 25 is based on the desired groove depth based on the relationship between the forming force indicated by the black triangle mark in FIG. 7 and the groove depth D. The molding force for the thickness D is obtained, and the obtained molding force is applied to the upper mold 12.
[0032]
In the present embodiment, as in the first embodiment, the ratio D / t between the groove depth D of each annular forming groove 25 and the plate thickness t of the stainless steel plate 7 is 1.0 ≦ D / t ≦. A value in the range of 2.5 is chosen. The reason why the upper and lower limit values of the ratio D / t are limited in this way is as follows.
[0033]
FIG. 14 is a graph showing the relationship between the ratio D / t of the groove depth D of the seven annular forming grooves 25 and the plate thickness t of the stainless steel plate 7 and the amount of thermal deformation of the frying pan 1. 4 is a graph showing a relationship between a ratio D / t between a groove depth D of a ring-shaped annular groove 25 and a plate thickness t of a stainless steel plate 7 and an output of an electromagnetic cooker 17. The method of measuring the amount of thermal deformation of the frying pan 1 and the output of the electromagnetic cooker 17 is the same as in the first embodiment.
[0034]
The plate thickness configuration of the frying pan 1 used to obtain the data shown in FIGS. 14 and 15 is aluminum plate: 1.3 mm, stainless steel plate: 0.4 mm, and the outer diameter of the frying pan 1 is 246 mm. The dimensions of each annular forming groove 25 are as described above, and the groove depth D of the annular forming groove 25 is 0 to 0.56 mm. The white triangle mark in FIG. 14 is a symbol representing the heat deformation amount after the heating, and the black triangle mark is a symbol representing the heat deformation amount after the cooling. FIG. 14 (1) is a graph showing the relationship between the amount of thermal deformation in the L direction and the ratio D / t, and FIG. 14 (2) shows the relationship between the amount of thermal deformation in the C direction and the ratio D / t. FIG. 14 (3) is a graph showing the relationship between the average amount of thermal deformation in the L direction and the C direction and the ratio D / t.
[0035]
From FIG. 14, the amount of thermal deformation of the bottom 3 of the frying pan 1 decreases as the ratio D / t increases. When the ratio D / t is 1.0 or more, the ratio D / t is zero for each amount of thermal deformation. It turns out that it becomes very small compared with the case of. Further, the present embodiment has a stronger correlation between the amount of thermal deformation and the ratio D / t than in the first embodiment, and it can be seen that the amount of thermal deformation can be controlled with higher accuracy by the ratio D / t.
[0036]
From FIG. 15, the output of the electromagnetic cooker 17 increases as the ratio D / t increases. When the ratio D / t is 1.0 or more, the output is 1.0 kW or more as in the case of the first embodiment. It can be seen that high output can be obtained stably. As described above, the ratio D / t is limited to 1.0 or more for this reason. The reason why the ratio D / t is limited to 2.5 or less is the same as in the case of the first embodiment.
[0037]
As described above, in the present embodiment, since a large number of annular forming grooves 25 are formed as compared with the first embodiment, the amount of thermal deformation of the frying pan 1 is stabilized with higher accuracy than in the first embodiment. Can be controlled. In addition, the same effects as those of the first embodiment can be obtained.
[0038]
As described above, in the first and second embodiments, the laminated plate that is the material of the frying pan 1 is composed of a non-ferrous metal plate and an iron or iron alloy plate, and an aluminum plate is used as the non-ferrous metal plate. Although a stainless steel plate is used as the alloy plate, the present invention is not limited to this combination, and other non-ferrous metal plates may be used. Moreover, although the cross-sectional shape of the annular forming grooves 9 and 25 is formed in a substantially semicircular shape, it may be formed in another cross-sectional shape, for example, a triangle.
[0039]
【The invention's effect】
As described above, according to the present invention, a plurality of annular forming grooves are formed concentrically on the bottom surface of the flat outer layer of the bottom of the pan for an electromagnetic cooker, so that the thermal deformation of the bottom of the pan is biased. Can be absorbed evenly. Moreover, since the ratio D / t between the depth D of each annular forming groove and the plate thickness t of the stainless steel plate is selected within the appropriate range, the ability to absorb heat deformation can be improved, and the bottom of the pan The amount of thermal deformation can be reduced, and the output of the electromagnetic cooker can be improved.
Moreover, since the outer layer of the pan for electromagnetic cookers is a stainless steel plate and the inner layer is an aluminum plate, the pan can be reduced in weight. Moreover, since the aluminum plate with favorable thermal conductivity is disposed in the inner layer of the pan, the temperature distribution at the bottom of the pan can be made uniform. Moreover, since the stainless steel plate is arrange | positioned in the outer layer of the said pan, the corrosion resistance and heat resistance of a pan can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a simplified configuration of a pan for an electromagnetic cooker according to a first embodiment of the present invention.
FIG. 2 is a bottom view as seen from II-II in FIG.
3 is a cross-sectional view taken along section line III-III in FIG.
FIG. 4 is a graph showing the relationship between the thickness of the stainless steel plate 7 forming the outer layer of the frying pan 1 and the output of the electromagnetic cooker.
FIG. 5 is a plan view for explaining a method of measuring the output of the electromagnetic cooker 17;
FIG. 6 is a cross-sectional view showing a situation when three annular forming grooves 9 are formed.
FIG. 7 is a graph showing the relationship between the groove depth D of the annular forming groove 9 and the forming force.
8 is a graph showing the relationship between the ratio D / t of the groove depth D of the three annular forming grooves 9 and the plate thickness t of the stainless steel plate 7 and the amount of thermal deformation of the frying pan 1. FIG.
9 is a graph showing the relationship between the ratio D / t of the groove depth D of the three annular forming grooves 9 and the plate thickness t of the stainless steel plate 7 and the output of the electromagnetic cooker 17. FIG.
FIG. 10 is a front view for explaining a method for measuring the amount of thermal deformation of the frying pan 1;
11 is a plan view for explaining a method of measuring the amount of thermal deformation of the frying pan 1. FIG.
FIG. 12 is a bottom view showing a simplified configuration of a bottom portion 3 of a frying pan 1 according to a second embodiment of the present invention.
FIG. 13 is a cross-sectional view showing a situation when seven annular forming grooves 25 are formed.
14 is a graph showing the relationship between the ratio D / t of the groove depth D of the seven annular forming grooves 25 and the plate thickness t of the stainless steel plate 7 and the amount of thermal deformation of the frying pan 1. FIG.
15 is a graph showing the relationship between the ratio D / t of the groove depth D of the seven annular forming grooves 25 and the plate thickness t of the stainless steel plate 7 and the output of the electromagnetic cooker 17. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Frying pan 3 Bottom part 9, 25 Annular shaping | molding groove | channel 10, 26 Annular protrusion 11, 27 Lower metal mold | die 14 Outer layer side bottom face 15 Inner layer side bottom face 17 Electromagnetic cooker

Claims (1)

In a pan for an electromagnetic cooker that has a bottom portion that extends flatly and a side wall portion that extends substantially perpendicular to the bottom portion, and is placed on the electromagnetic cooker and induction heated by electromagnetic induction.
An aluminum plate and a stainless steel plate that is thinner than the aluminum plate are composed of laminated plates that are pressed in layers,
Stainless steel plates are arranged on the outer layer side of the bottom and side walls,
On the bottom surface on the outer layer side of the bottom part, a plurality of annular molding grooves are formed by pressing concentrically around the center part of the bottom surface ,
The ratio D / t between the depth D of each annular forming groove and the thickness t of the stainless steel plate is selected to be in the range of 1.0 ≦ D / t ≦ 2.5,
The plate thickness t is selected in the range of 0.4 mm to 1.0 mm,
The plurality of annular forming grooves are concentrically formed around the center of the bottom surface in a diameter range of 60 mm to 120 mm,
The thickness of the said aluminum plate is chosen by the value of the range of 1.3 mm-2.6 mm, The pan for electromagnetic cookers characterized by the above-mentioned .

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