Rice cooking utensil

Abstract

The utility model provides a rice cooking utensil, and aims to solve the technical problems that the rice cooking utensil is not easy to clean and food is easy to remain. The rice cooking utensil comprises an inner container formed by stretching a polished and embossed metal plate, the inner container comprises a metal layer forming the inner wall of the inner container, and a plurality of independent grooves are formed in the metal layer; the depth h of each independent groove ranges from 0.01 mm to 0.05 mm, a surface connecting rib is arranged between every two adjacent grooves, the top surface of each connecting rib is a first smooth face, and the bottom face of each independent groove is a second smooth face. According to the zero-coating inner container, the grooves are independent, the grooves are isolated from one another through the connecting ribs, and the adjacent grooves are not communicated with one another, so that the non-stick performance of the zero-coating inner container can be improved. Through the arrangement of the first smooth surface and the second smooth surface, sticky rice milk can be washed away more easily after being dried in the cooking process, and therefore food residues are reduced.

Description

[0001] This application claims priority to a utility model patent application filed on December 8, 2023, with application number 2023233584516, and invention name “A rice cooking utensil”. Technical Field

[0002] The present application belongs to the technical field of kitchen appliances, and in particular, relates to a rice cooking utensil. Background Art

[0003] In the existing rice cooking utensils, by forming grooves and protrusions on the inner surface of the inner pot, it is no longer necessary to use a non-stick coating to improve the non-stick performance of the rice inner pot, and a zero-coating non-stick effect is achieved.

[0004] Some existing 0-coating inner pots have independent grooves formed on the inner surface of the inner pot, and the independent grooves are separated by connecting ribs. During the cooking process, rice slurry is stored in the independent grooves, and the connecting ribs support the rice. For the independent grooves, when the water is evaporated, the starch precipitated from the rice slurry inside the grooves is easy to adhere to the grooves. For the connecting ribs, the starch adhered to the upper surface of the connecting ribs is also easy to leave food residue after the starch grains become dry, and it is not very easy to clean. Summary of the invention

[0005] The present application provides a rice cooking utensil to solve the above-mentioned technical problems of being difficult to clean and easily having food residue.

[0006] On the one hand, the technical solution adopted in one embodiment of the present application is:

[0007] A rice cooking utensil comprises an inner pot formed by stretching a polished and embossed metal plate, the inner pot comprising a metal layer constituting the inner wall of the inner pot, the metal layer being provided with a plurality of independent grooves; the depth h of the independent grooves is 0.01 to 0.05 mm, surface connecting ribs are provided between adjacent grooves, the top surface of the connecting ribs is a first smooth surface, and the bottom surface of the independent grooves is a second smooth surface.

[0008] As a preferred implementation manner of this embodiment, the groove has a groove bottom surface, the groove has a groove side surface formed by one side of the connecting rib, and the groove side surface extends in the depth direction of the groove and is inclined toward the outside in the width direction of the groove.

[0009] As a preferred implementation manner of this embodiment, the connecting rib includes an intersection portion, and the groove side also has a first side surface and a second side surface located in the same groove, the first side surface and the second side surface are connected at an angle transition at the intersection portion, and the depth of the first side surface or the second side surface at the intersection is compared with the center depth of the groove, and the ratio is greater than or equal to 0.9 and less than 1.

[0010] As a preferred implementation manner of this embodiment, the shape size of the groove on the metal plate is larger than the shape size of the connecting rib.

[0011] As a preferred implementation of this embodiment, the groove has a mouth width and a bottom width, and the ratio of the mouth width to the bottom wall width is Wherein θ is the angle between the groove side and the groove bottom; the angle θ is controlled between 90-150°.

[0012] As a preferred implementation manner of this embodiment, the groove side surface and the groove bottom surface transition at an angle, and the groove side surface and the groove bottom surface are connected at the angle respectively.

[0013] As a preferred implementation manner of this embodiment, the width of the connecting rib is 0.1-0.4 mm, the width of the groove is 0.2-0.8 mm, and the width of the connecting rib is less than 1 / 3 of the width of the groove.

[0014] As a preferred implementation manner of this embodiment, the inner liner also includes at least an aluminum layer and a stainless steel layer, the stainless steel layer and the aluminum layer are combined to form a stainless steel composite plate, the stainless steel layer has a bonding surface combined with the aluminum layer, the bonding surface includes a first bonding portion corresponding to the position of the groove, and a second bonding portion corresponding to the connecting rib, and the ratio of the distance of the first bonding portion relative to the bottom wall of the groove to the distance of the second bonding portion relative to the upper surface of the connecting rib is greater than 0.95 and less than or equal to 1.

[0015] As a preferred implementation of this embodiment, the surface roughness of the second smooth surface is Ra2-9 μm.

[0016] As a preferred implementation of this embodiment, the surface roughness of the first smooth surface is Ra2-9 μm.

[0017] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows:

[0018] The grooves of the present application are independent, and connecting ribs are present between the grooves to isolate each other, and adjacent grooves are not connected. In this way, the non-stick performance of the 0-coated inner pot can be improved. Specifically, the grooves are separated by connecting ribs so that the grooves are isolated from each other and relatively independent. For this reason, the independent grooves and the connecting ribs that serve as isolation allow the inner surface of the inner pot to have a certain water storage capacity, thereby enhancing the maintenance time of the water film between the rice and the inner surface of the inner pot, thereby improving the non-stick performance of the rice; further, through the provision of the first smooth surface and the second smooth surface, the sticky rice slurry or starch granules can be dried during the cooking process to reduce the adhesion, thereby making it easier to be washed away, thereby reducing food residue.

[0019] In some preferred embodiments, the groove side extends in the depth direction of the groove and is inclined toward the outside of the width direction of the groove. In this way, during the cleaning process, the cleaning tool is convenient for cleaning the food remaining in the independent groove, thereby reducing food residue.

[0020] In some preferred embodiments, the first side surface and the second side surface are connected at an angle transition at the intersection, so that the groove is extended as close to the intersection as possible, so that the size of the intersection is reduced, thereby increasing the area occupied by the groove; the depth at the intersection is close to the depth at the center of the bottom surface of the groove, and the ratio is not less than 0.9, so that the depth size consistency of the groove is better, thereby improving the non-stick performance of the inner pot.

[0021] In some preferred embodiments, the groove has a mouth width and a bottom width, and the ratio of the mouth width to the bottom wall width is Wherein θ is the angle between the side surface of the groove and the bottom surface of the groove; the angle θ is controlled between 90-150°; when the angle θ is less than 90°, the groove cannot be manufactured and processed; when the angle is greater than 150°, the ability of the groove to store water or rice slurry will be reduced, resulting in the problem that the rice on the side wall of the inner pot is easy to stick and the non-stick performance is poor.

[0022] In some preferred embodiments, during pressing, the stainless steel layer is under pressure and may also deform at the joint surface. Correspondingly, the distance between the first joint portion and the bottom surface of the groove and the distance between the second joint portion and the upper surface of the connecting rib 302 are in a ratio of greater than 0.95 and less than or equal to 1. Therefore, after pressing, for stainless steel, the material thickness is relatively consistent regardless of the position, which is conducive to uniform heat transfer, so that the temperature of the inner wall of the inner pot is uniform and the non-stick performance is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 A cross-sectional view of a cooking utensil provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of an embossed metal sheet provided in an embodiment of the present application;

[0026] Figure 3 A cross-sectional view of the inner tank structure provided in an embodiment of the present application;

[0027] Figure 4 A flowchart of the manufacturing method of an embodiment of the present application;

[0028] Figure 5 This is a partially enlarged schematic diagram of the groove and the connecting rib in the first embodiment of the present application;

[0029] Figure 6 is a cross-sectional view of the metal layer in Example 1 of the present application;

[0030] Figure 7 This is a partial enlarged schematic diagram of the intersection in Example 1 of the present application;

[0031] Figure 8 A cross-sectional view of a composite plate in an embodiment of the present application;

[0032] Fig. 9 A schematic diagram of another embossed metal sheet provided in an embodiment of the present application;

[0033] Fig.10 A partially enlarged schematic diagram of the connecting groove and protrusion provided in the second embodiment of the present application;

[0034] Fig.11 It is a cross-sectional view of the metal layer in the second embodiment of the present application;

[0035] Fig.12 It is a partially enlarged schematic diagram of the cross-connection part in the second embodiment of the present application.

[0036] in,

[0037] Pot body 10; Heating device 105;

[0038] Pot cover 20; metal cover plate 21; sealing ring 22;

[0039] Inner pot 30; inner pot bottom wall 31; inner pot side wall 32; cooking cavity 33; flange 34; independent groove 301; connecting rib 302; first smooth surface 320; second smooth surface 310; stainless steel layer 311; aluminum layer 312; groove side 303; groove bottom 313; intersection 304; first side 3031; second side 3032; bonding surface 305; first bonding part 3051; second bonding part 3052; connecting groove 307; protrusion 306; cross-connecting part 309. DETAILED DESCRIPTION

[0040] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0041] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0042] In addition, in the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0043] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] In the present application, unless otherwise clearly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0045] The present application proposes a rice cooking utensil, which may be an electric rice cooker or a pressure cooker. In some other embodiments, the rice cooking utensil may be other cooking utensil capable of cooking rice.

[0046] refer to Figure 1 , shows an electric rice cooker, which comprises a pot body 10, a pot cover 20 and an inner pot 30, wherein the inner pot 30 is arranged in the pot body 10, the inner side of the inner pot 30 is in contact with the rice through a metal layer, the pot cover 20 is covered on the pot body 10, and the pot body 10 is provided with a heating device 105 for heating the inner pot 30. During the cooking process, a rice-water mixture is added into a cooking cavity 33 in the inner pot 30, and the rice is cooked under the heating of the heating device 105 at the bottom of the inner pot 30.

[0047] In a specific embodiment of the present application, the cooking utensil cooks rice through an uncoated or zero-coated inner pot. Most existing inner pots are coated inner pots, that is, a Teflon coating (scientific name polytetrafluoroethylene, abbreviated as PTFE) is provided on the inner surface of the inner pot. The uncoated inner pot of the present application is relative to the above-mentioned coated inner pot. A coating is no longer provided on the substrate of the inner pot, so the inner wall of the inner pot is a metal layer that can come into contact with food. The metal layer can be stainless steel. When cooking, food is directly contacted and cooked through the metal layer of the inner pot, thereby eliminating the coating shedding of the coated inner pot and the dietary health problems caused by the coating itself.

[0048] The existing 0 coating inner pot is formed with grooves and protrusions on the inner surface of the stainless steel by chemical etching. Although chemical etching is efficient, it is highly polluting and easy to leave residues, which will cause a defective rate in the later stage. In addition, grooves or protrusions can be formed by laser engraving, but the laser engraving processing efficiency is low and it is not suitable for mass production. In addition, grooves or protrusions can be formed by mechanical pressing, which can meet the requirements of processing efficiency. However, during the application of mechanical pressing, there is a problem of poor consistency in the surface roughness, surface friction coefficient and adhesion coefficient of the grooves and protrusions, which leads to poor consistency in the non-stick performance of the 0 coating inner pot. For example, there is a problem that some parts are prone to causing rice to stick to the pot, while some parts have better non-stick performance of rice.

[0049] At the same time, during the mechanical pressing process, the manufacturing process can be used to improve the consistency of product molding. Since the size of the molded grooves and protrusions is small, the requirements for processing accuracy also increase accordingly. In order to obtain good processing consistency and reduce the defective rate.

[0050] The present application manufactures the inner liner by the following method: polishing the surface of the metal plate to form a smooth surface, embossing the smooth surface to form a plurality of independent quadrilateral grooves, wherein the depth of the independent quadrilateral grooves 301 is 0.01 to 0.05 mm, and the width is 0.3 mm to 0.6 mm; smooth ribs are formed between adjacent independent grooves 301, and the width of the smooth ribs is 0.1 mm-0.3 mm; the formed metal plate is as follows Figure 2 or Fig. 9 As shown; the metal sheet having multiple independent grooves 301 and smooth ribs is stretched to form an inner liner, and the formed inner liner is as shown Figure 3 shown.

[0051] like Figure 4 As shown, the specific steps include:

[0052] S10: polishing the surface of the sheet metal plate to obtain a smooth surface on the sheet metal plate;

[0053] S20: Processing the metal plate by a mechanical pressing process to form a plurality of independent grooves on the smooth surface after the polishing process, and forming smooth ribs between adjacent independent grooves 301;

[0054] S30: Processing a metal plate having a plurality of independent grooves 301 and smooth ribs into an inner liner through a stretching process; wherein the independent grooves are quadrilateral, the depth of the grooves is 0.01 to 0.05 mm, the width is 0.3 mm to 0.6 mm, and the width of the smooth ribs is 0.1 mm-0.3 mm.

[0055] It should be noted that the width of the groove is the distance between two opposite sides of the four sides of the groove, rather than the distance between adjacent sides and the diagonal distance of the quadrilateral. The width of the smooth rib is the thickness of any side of the quadrilateral, rather than the length of the side.

[0056] The purpose of the metal sheet after polishing is to make the surface roughness of the metal sheet reach mirror 8K, and the surface roughness is Ra0.02-0.03μm; because the metal surface is smooth enough before pressing, the metal surface defects are removed, so the pressed protrusions (smooth ribs) and grooves have better morphological consistency. For the protrusions (smooth ribs), not only the width, length and depth of the protrusions (smooth ribs) can be guaranteed, but also the surface roughness of the protrusions can be guaranteed. During the cooking process, the inner surface of the inner pot is provided with a number of protrusions, and the morphological size and surface roughness of each protrusion are consistent. Therefore, the protrusions at various places on the inner surface of the inner pot have a consistent support effect on the rice, avoiding the problem of poor non-stick consistency of the inner surface of the inner pot. For the grooves, pressing on the mirror-surface metal sheet not only makes the morphology and size of each groove consistent, but also the surface roughness of each part in the groove consistent. Compared with the grooves formed by chemical etching or laser engraving, mechanical pressing (embossing) uses the ductility of the metal to form the grooves. For this reason, the bottom wall and side wall of the groove are part of the mirror or smooth surface of the metal sheet before forming. After forming, part of the mirror surface of the metal sheet becomes the bottom wall of the groove, and part becomes the side wall of the groove. For this reason, the surface roughness of the side wall and the bottom wall is close. For a single groove, since the surface roughness of the side wall and the bottom wall is close, the consistency of the surface roughness of each part in the groove is good. The groove is a quadrilateral, so that the smooth ribs between adjacent grooves serve as one of the sides of the quadrilateral, so that the thickness of the smooth ribs along the length direction is consistent, and there will be no thickening or thinning phenomenon. In this way, the area occupied by the independent groove is indirectly larger than the area occupied by the smooth ribs per unit area, so that the non-stickiness is better. During the embossing process, the depth of the independent groove is controlled at 0.01 to 0.05 mm, and the width of the smooth ribs is 0.1 mm-0.3 mm, which can avoid excessive deformation of the metal sheet and reduce the change in roughness after pressing. In addition, when the groove depth h is small When the depth h is greater than 0.01, firstly, the volume of the groove is limited, thereby reducing the ability of the groove to store water or rice slurry. Secondly, the smooth ribs are difficult to form effective support for the rice, and the rice is easy to contact the bottom surface of the groove, reducing the non-stick performance of the inner pot. Thirdly, when washing, the smooth ribs are not strong enough and are easily worn, thereby reducing the non-stick performance of the inner pot. When the groove depth h is greater than 0.05mm, on the one hand, it is easy for the groove to hide dirt and grime, and on the other hand, it is easy to make the difference between the width of the mouth and the width of the bottom wall too large, making the top of the smooth ribs too thin, thereby causing the problem that the strength of the smooth ribs of the inner pot is not enough and is easy to wear. Finally, the inner pot is stretched to form the inner pot. Through the inner pot manufacturing method of this embodiment, the roughness of the inner pot obtained is slightly changed, the non-stick performance is significantly improved, and it is not easy to have food residue. When the width of the smooth ribs is less than 0.1mm, the strength of the smooth ribs is too low and easy to wear. When it is greater than 0.3mm, the area occupied by the smooth ribs per unit area will be larger, reducing the non-stick performance.

[0057] In some existing forming processes, the surface of the metal sheet is not mirror-polished before pressing. Instead, the inner and outer surfaces of the inner pot are polished after pressing and stretching to form the inner pot shape. In this way, forming first and then polishing can easily cause significant damage to the morphology of the protrusions and grooves. If the polishing force is too strong, the protrusions on the inner surface of the inner pot will be ground off first, and the depth of the groove will also be reduced because the material on the surface of the inner pot is ground off, which will cause certain damage to the non-stick performance of the rice in the inner pot. In addition, for the groove, during the polishing process, due to the small size of the groove, it is difficult for the polishing tool to penetrate into the groove. Although some flexible polishing tools can contact the middle bottom wall of the groove, it is difficult to contact the corners, side walls and other parts of the groove that are not easy to contact, which makes it difficult to polish the groove evenly, and the inability to fully polish results in poor consistency of the non-stick performance.

[0058] In the present application, the inner surface of the molded inner liner having multiple independent grooves 301 and smooth ribs is polished twice.

[0059] Polishing specifically includes rough polishing, semi-fine polishing, fine polishing, waxing, and polishing;

[0060] Secondary polishing specifically includes sand polishing and scouring pad polishing;

[0061] Generally speaking, the number of polishing processes is greater than the number of secondary polishing processes. More polishing processes are required, requiring a smaller final surface roughness value and a smoother surface. Since there is polishing before the secondary polishing, the surface roughness of the smooth surface formed by polishing is smaller than the surface roughness of the inner surface of the liner after the secondary polishing, compared with the polishing before forming the grooves and smooth ribs and the secondary polishing. In this way, the problem of some existing forming processes, which are prone to significant damage to the morphology of protrusions and grooves by first stretching and then polishing, and the problem of difficult uniform polishing of the corners and side walls close to the grooves that are not easy to contact, is avoided.

[0062] Rough polishing: Use a 600# sand belt to grind the surface of the metal sheet back and forth. The goal of this process is to remove the oxide layer of the metal sheet and the bruises on the surface of the metal sheet, so that there are basically no large scratches and bruises on the surface.

[0063] Semi-fine polishing: Use an 800# abrasive belt to grind the surface of the metal plate back and forth. This process is mainly to correct the defects that occurred in the previous process and to further fine-grind the marks produced after rough polishing. The marks left by the previous process must be ground repeatedly to achieve a scratch-free surface of the metal plate and basically brighten it.

[0064] Fine polishing: Use 1000# abrasive belt to correct the fine lines in the previous process. The grinding method is the same as above. The goal of this process is to make the surface of the metal sheet brighter. The metal sheet after grinding in this process should be close to the mirror effect.

[0065] Waxing: Use a wool wheel driven by a high-speed motor and large blue wax to mirror-polish the metal sheet after the previous polishing process, rather than further grinding.

[0066] Polishing: This process is the last step of mirror polishing. Use a clean cotton wheel to rub the mirror-polished metal sheet surface to clean and polish the metal sheet after all the previous processes. The goal of this process is to make the metal sheet surface flawless and polish the waxed and polished workpiece to a brightness of 8k.

[0067] In some specific embodiments of the present application, the surface roughness of the smooth surface formed by polishing the metal plate surface is less than the surface roughness of the inner surface of the inner liner after molding. Therefore, compared with the polishing before the grooves and smooth ribs after molding, the surface roughness of the smooth surface formed by polishing is less than the surface roughness of the inner surface of the inner liner after molding. This manufacturing method prevents the roughness of the grooves and smooth ribs after molding from accumulating too much. The overall roughness of the inner liner surface after molding is obtained based on the surface roughness of the smooth surface. When a good parameter foundation is obtained, the roughness of the inner liner surface after molding is also relatively good.

[0068] In some specific embodiments of the present application, the mechanical pressing process is a rolling process, in which a rolling machine drives an embossing roller to rotate and applies pressure to the metal sheet, thereby forming a pattern on the metal sheet. Specifically, the embossing step further includes:

[0069] A pattern is formed on an embossing roller, and the smooth side of the metal sheet is pressed by the embossing roller to form a pattern consisting of smooth ribs and grooves on the smooth side.

[0070] The grooves and protrusions (smooth ribs, connecting ribs 302) are obtained by a rolling process, which has high processing efficiency and can complete the pressing of patterns in rolls.

[0071] In the present application, the material of the metal plate is a steel-aluminum-steel composite plate. The stainless steel plate, the alloy aluminum plate and the stainless steel plate are heated in an electric furnace, and after being taken out of the furnace, they are rolled into a composite plate by a rolling machine; the composite plate makes the heat transfer performance of the inner pot better, the heating is more uniform, and the effect of cooking food is better.

[0072] The embossing roller is formed with a pattern, and the smooth side of the composite plate is pressed by a rolling machine to form a pattern consisting of protrusions and grooves on the smooth side.

[0073] Compared with etching grooves and protrusions on the composite sheet, the composite sheet will be stretched and thinned during the process of pressing the grooves and protrusions. Therefore, the thickness of the composite sheet is increased by 10%-22% compared with the thickness of the composite sheet used in the etching process, for example, 1.5mm is increased to 1.65-1.70mm; 2.0mm is increased to 2.3-2.35mm; 3.0mm is increased to 3.55-3.65mm.

[0074] The grooves are formed by rolling, and the patterns on the embossing roller are formed on the cylindrical surface. During the pressing process, the protrusions on the cylindrical surface will press out grooves on the metal sheet, and the grooves on the cylindrical surface will press out protrusions on the metal sheet. For the embossing roller, the grooves are processed, and relatively speaking, the protrusions are the unprocessed parts on the cylindrical surface. Since the cylindrical surface can ensure good roundness before processing, the concentricity of each part of the cylindrical surface can be controlled very high, and the dimensional error is small, while the grooves are processed later, so the side walls of the grooves may not maintain the radial direction, and the bottom wall of the grooves may not maintain the arc surface coaxial with the cylindrical surface, so the convex surface of the embossing roller The relative groove has a higher dimensional accuracy. Then, in the process of pressing the flat metal plate, the groove formed by the protrusions of the embossing roller has a higher dimensional accuracy, while the protrusions formed by the grooves of the embossing roller have a relatively low morphological consistency; preferably, the morphological size of the groove on the metal plate is larger than the morphological size of the connecting rib 302, and the morphological area occupied by the connecting rib 302 per unit area is smaller than the morphological area occupied by the groove. In this way, the morphology on most areas of the surface of the metal plate can be grooves, and the dimensional consistency of the grooves is better during pressing, thereby making the non-stick consistency of the entire liner better.

[0075] In some embodiments, the morphological size of the protrusion may be smaller than the morphological size of the groove, that is, the area occupied by the protrusion is larger than the area occupied by the groove.

[0076] After pressing, the side with the grooves and smooth ribs is coated to protect the side of the metal sheet with the grooves and smooth ribs.

[0077] The surface of the metal sheet with the grooves or protrusions pressed thereon is coated to protect the morphology of the metal surface. In some embodiments of the present application, the protective film can be retained during the stretching process to reduce the damage to the surface morphology caused by the stretching die.

[0078] After stretching, the wall of the inner liner can be lightly ground manually to avoid serious damage to the protrusions.

[0079] The inner liner is then subjected to physical vapor deposition to optimize the wear resistance of the grooves on the inner surface of the inner liner, thereby increasing the service life of the inner liner.

[0080] The surface roughness of the groove bottom surface 313 of the groove is 2-9μm, and the surface roughness Ra of the upper surface of the smooth rib is 2-9μm. Although the stainless steel reaches the level of mirror surface 8k before embossing, the subsequent process will increase the surface roughness of the stainless steel liner. Nevertheless, due to the forming method of first polishing, then embossing, and then stretching, the cumulative error of the entire process is smaller, and the size and parameters of each groove and protrusion are more consistent, thereby ensuring good non-stick consistency.

[0081] In some specific embodiments, the surface roughness Ra of the bottom surface of the groove is 6-9 μm; the surface roughness Ra of the upper surface of the smooth rib is 3-8 μm; the inner liner after stretching will also undergo some process steps, and the surface roughness Ra of the bottom surface of the groove after processing is 6-9 μm, and the surface roughness Ra of the upper surface is 3-8 μm.

[0082] It should be noted that the surface roughness of the groove bottom and the smooth ribs is measured after optically magnifying the grooves and smooth ribs on the inner container surface by about 800-1500 times. For example, at 1000 times, the surface roughness of the groove bottom is 7.5μm, and at 1200 times, the roughness is 8.7μm.

[0083] The present application also proposes a rice cooking utensil based on the above-mentioned manufacturing method, such as Figure 1 As shown, it includes a pot cover 20 and a pot body 10, wherein the pot body 10 is provided with an inner pot 30 made by any of the inner pot making methods described above, the pot cover 20 is provided with a metal cover plate 21, the metal cover plate 21 is provided with a sealing ring 22, the inner pot 30 is provided with a flange 34 on the edge of the inner pot, the upper surface of the flange 34 is a plane with the groove removed after polishing, and the sealing ring 22 abuts on the plane; through the above method, it can be ensured that the depth of the independent groove 301 is 0.01 to 0.05mm, and it can be ensured that the smooth ribs and the independent groove 301 have good surface roughness, and the inner pot made thereby has good non-stick consistency of rice. On this basis, in order to ensure the sealing effect, the flange on the edge of the inner pot is a plane, and the sealing ring abuts on the plane, so as to avoid air leakage.

[0084] In addition, the specific embodiment of the present application proposes a rice cooking pot, such as Figure 3 As shown, the inner liner includes an inner liner side wall 32 and an inner liner bottom wall 31, and may include the following two embodiments. The inner liner may be formed by stretching a polished and embossed metal sheet, and polishing and embossing are existing manufacturing processes; the specific implementation methods are as follows:

[0085] Embodiment 1:

[0086] The inner liner includes a metal layer constituting the inner wall of the inner liner, such as Figure 5 As shown, the metal layer is provided with a plurality of independent grooves; the depth h of the independent groove 301 is 0.01 to 0.05 mm, and surface connecting ribs 302 are provided between adjacent grooves, the top surface of the connecting ribs 302 is a first smooth surface 320, and the bottom surface of the independent groove 301 is a second smooth surface 310.

[0087] Embodiment 2:

[0088] The inner liner includes a metal layer constituting the inner wall of the inner liner, such as Figure 9-10 As shown, the metal layer is provided with a plurality of independent protrusions 306 ; the height h of the protrusions 306 is 0.01 to 0.05 mm, connecting grooves 307 are provided between adjacent protrusions 306 , the top surface of the protrusions 306 is a first smooth surface 320 , and the bottom surface of the connecting grooves 307 is a second smooth surface 310 .

[0089] In the above two embodiments, grooves, protrusions or connecting ribs 302 are formed on the surface of the inner pot. The difference is that the grooves in embodiment one are independent, and connecting ribs exist between the grooves to isolate each other, and adjacent grooves are not connected. Connecting ribs exist between the grooves to isolate each other, and adjacent grooves are not connected. In this way, the non-stick performance of the 0-coated inner pot can be improved. Specifically, the grooves are separated from each other by connecting ribs, so that each groove is isolated from each other and relatively independent. For this reason, the independent grooves and the connecting ribs that serve as isolation make the inner surface of the inner pot have a certain water storage capacity, enhance the maintenance time of the water film between the rice and the inner surface of the inner pot, and thus improve the non-stick performance of the rice; while the grooves in embodiment two are connected, and the protrusions are independent of each other.

[0090] In the above scheme, no matter the groove is independently provided or the protrusion is independently provided, for the groove, protrusion or connecting rib, the top surface of the protrusion or connecting rib is the first smooth surface 320 and the bottom surface of the groove is the second smooth surface 310 .

[0091] like Figure 2 As shown, the inner pot of the first embodiment is formed by stretching the embossed metal sheet shown in the figure. The first smooth surface 320 and the second smooth surface 310 have a surface roughness of Ra2-9 microns. During the cooking process, the first smooth surface 320 and the second smooth surface 310 are provided, and the sticky rice paste or starch particles are dried, which reduces the adhesion, so that they are easier to be washed off, thereby reducing food residues.

[0092] In the first embodiment of the present application, Figure 6As shown, the groove has a groove bottom surface 313 (second smooth surface 310), and the groove has a groove side surface 303 formed by one side of the connecting rib 302. The groove side surface 303 extends in the depth direction of the groove and is inclined toward the outside of the width direction of the groove. In this way, during the cleaning process, the cleaning tool can easily clean the food remaining in the independent groove, thereby reducing food residue.

[0093] It should be noted that after the metal sheet is stretched to become the inner liner, the groove bottom surface 313 located on the rotational side wall of the inner liner is a curved surface at a macroscopic level. However, since the size of the independent groove 301 is small compared to the size of the rotational side wall of the inner liner, the groove bottom surface 313 can be approximately regarded as a plane; and the inner liner bottom wall 31 is relatively flat at a macroscopic level, and the groove bottom surface 313 corresponding to the groove on the inner liner bottom wall 31 is also closer to a plane from a microscopic perspective.

[0094] The groove has a mouth width D1 and a bottom width D2, and the ratio of the mouth width to the bottom wall width is Wherein θ is the angle between the groove side surface 303 and the groove bottom surface 313 , and h is the depth of the groove.

[0095] like Figure 6 As shown, there is an inclined angle θ between the outer inclined groove side surface 303 and the groove bottom surface 313, so that the groove is trumpet-shaped in the depth direction. In order to avoid a large difference between the groove mouth width and the bottom width, the angle θ is controlled between 90-150° and h is controlled between 0.01-0.05mm.

[0096] like Figure 6 As shown, the groove side surface 303 and the groove bottom surface 313 transition with an angle, and the groove side surface 303 and the groove bottom surface 313 are connected at the angles.

[0097] It should be understood that whether the groove side and the groove bottom 313 transition at an angle can be determined by whether the groove side and the groove bottom 313 can be approximately flat. For example, in the present application, the groove depth and width are relatively small, and the groove side and the groove bottom 313 are relatively straight. The groove side extends roughly in the depth direction of the groove, and the groove bottom 313 extends roughly in the width direction of the groove, and the depth direction and the width direction are orthogonal. Therefore, it can be considered as an angle transition. When the groove side and the groove bottom 313 are obviously curved surfaces, and the transition is smooth, and the angle cannot be clearly distinguished, it is a non-angle transition.

[0098] When the angle θ is less than 90°, the groove cannot be manufactured and processed. When the angle is greater than 150°, the water storage or rice slurry storage capacity of the groove will be reduced, resulting in the problem that the rice at the side wall 32 of the inner pot is easy to stick and the non-stick performance is poor. When the groove depth h is less than 0.01, firstly, the volume of the groove is limited, thereby reducing the water storage or rice slurry storage capacity of the groove. Secondly, the protrusion or connecting rib is difficult to form an effective support for the rice, and the rice is easy to contact the bottom surface 313 of the groove, reducing the non-stick performance of the inner pot. Thirdly, when washing, the protrusion or connecting rib is not strong enough and is easy to be worn, thereby reducing the non-stick performance of the inner pot. When the groove depth h is greater than 0.05mm, on the one hand, it is easy for the groove to be more likely to hide dirt and grime. On the other hand, it is easy to make the difference between the width of the mouth and the width of the bottom wall too large, making the top of the protrusion or connecting rib too thin, thereby causing the protrusion or connecting rib of the inner pot to be insufficiently strong and easy to wear.

[0099] In some embodiments, the angle value can also be 130, 132, 145 degrees or other values, and the groove depth h can also be 0.018, 0.025, 0.027, 0.028, 0.03 mm or other values. Correspondingly, the ratio of the mouth width to the bottom wall width is between 1-1.08, and the preferred ratio is greater than 1.

[0100] In the first embodiment, Figure 7 As shown, the connecting rib 302 includes a crossing portion 304, and the groove side also has a first side 3031 and a second side 3032 located in the same groove, the first side 3031 and the second side 3032 are cross-connected at the crossing portion 304, and the depth of the first side 3031 or the second side 3032 at the crossing connection is compared with the center depth of the groove, and the ratio is: greater than or equal to 0.9 and less than 1.

[0101] As described above, the grooves are formed by rolling, and the pattern on the embossing roller is formed on the cylindrical surface. During the pressing process, the protrusions on the cylindrical surface will press out grooves on the metal plate, and the grooves on the cylindrical surface will press out protrusions on the metal plate. For the embossing roller, the grooves are processed. Relatively speaking, the raised surface of the embossing roller has a higher dimensional accuracy than the grooves. For this reason, preferably, the morphological size of the grooves on the metal plate is larger than the morphological size of the connecting ribs 302. Within a unit area, the area occupied by the connecting ribs 302 is smaller than the area occupied by the grooves. In this way, the morphology on most areas of the surface of the metal plate can be grooves, and the dimensional consistency of the grooves is better during pressing, thereby making the non-stick consistency of the entire liner better; the connecting ribs 302 on the surface of the metal plate will be connected to each other, while the grooves are relatively independent.

[0102] The connecting ribs 302 are connected to each other through the intersection 304. In order to further reduce the area occupied by the connecting ribs 302 and increase the area occupied by the groove, the groove side 303 has a first side 3031 and a second side 3032. The first side 3031 and the second side 3032 are connected at an angle transition at the intersection 304, so that the groove is extended as close to the intersection 304 as possible, so that the size of the intersection 304 is reduced, thereby increasing the area occupied by the groove.

[0103] It should be understood that whether the groove side surface (first side surface 3031) and the groove side surface (second side surface 3032) transition at an angle can be determined by whether the groove side surface and the groove side surface are approximately planar. For example, in the present application, the width dimension of the groove along the first side surface 3031 and the width dimension along the second side surface 3032 are relatively small, and the first side surface 3031 and the second side surface 3032 are relatively straight, the first side surface 3031 extends roughly toward one side of the groove, and the second side surface 3032 extends roughly toward the other side of the groove, so it can be considered as an angle transition. When the groove side surface and the groove side surface are both obviously curved surfaces, and the transition arc transition is smooth, and the angle cannot be clearly distinguished, then it is a non-angle transition.

[0104] The depth of the first side surface 3031 or the second side surface 3032 at the intersection is the depth from the top of the groove to the transition point of the angle. The center depth of the groove is the depth from the mouth of the groove to the center of the groove bottom surface 313. The two depths are greater than or equal to 0.9 and less than 1.

[0105] The depth at the cross connection is close to the depth at the center of the groove bottom surface 313, and the ratio is not less than 0.9, so that the depth size consistency of the groove is better, thereby improving the non-stick performance of the inner pot.

[0106] The width D3 of the connecting rib 302 is less than 1 / 3 of the width of the groove D1, so that the area of ​​the groove accounts for a larger proportion. Since the size consistency of the groove is better controlled during processing, the overall size consistency of the inner pot is also better and the non-stickiness is better.

[0107] like Figure 8 As shown, the liner also includes at least an aluminum layer 312 and a stainless steel layer 311, the stainless steel layer 311 and the aluminum layer 312 are combined to form a stainless steel composite plate, the stainless steel layer 311 has a bonding surface 305 combined with the aluminum layer 312, the bonding surface 305 includes a first bonding portion 3051 corresponding to the position of the groove, and a second bonding portion 3052 corresponding to the connecting rib 302, and the ratio of the distance of the first bonding portion 3051 relative to the bottom surface of the groove to the distance of the second bonding portion 3052 relative to the upper surface of the connecting rib 302 is greater than 0.95 and less than or equal to 1.

[0108] During pressing, the stainless steel layer is under pressure and may also be deformed at the joint surface 305. Correspondingly, the distance between the first joint portion 3051 and the bottom surface 313 of the groove and the distance between the second joint portion 3052 and the upper surface of the connecting rib 302 are in a ratio of greater than 0.95 and less than or equal to 1. Therefore, after pressing, for stainless steel, the material thickness is relatively consistent regardless of the position, which is conducive to uniform heat transfer, so that the temperature of the inner wall of the inner pot is uniform and the non-stick performance is good.

[0109] like Figure 6 As shown, the width dimension D1 of the connecting rib 302 is 0.1-0.4 mm, and the width dimension D1 of the groove is 0.2-0.8 mm.

[0110] In the first embodiment, the inner container includes an inner container bottom wall 31 and an inner container side wall 32 . The groove on the inner container bottom wall 31 is square, and the groove on the inner container side wall 32 is rhombus-shaped.

[0111] For Example 2, Fig. 9 As shown, the inner pot of the second embodiment is formed by stretching the metal plate after embossing in the figure. The grooves are connected to each other, so that the rice slurry in the grooves will be able to flow along the connecting grooves 307. Especially for some inner pots with good heating effect, since the bottom part is easy to overheat, the connecting grooves 307 can play a role in keeping the water film from disappearing easily; the independent protrusions support the rice, which can ensure a good heat transfer effect. During the cooking process, the first smooth surface and the second smooth surface are set, so that the starch attached to the connecting grooves can be easily washed off. On the one hand, it reduces the residue of food in the grooves, and on the other hand, it avoids the risk of clogging of the connecting grooves, so that the rice slurry can flow in the connecting grooves, thereby ensuring that the non-stick performance of the inner pot is continuously in a good state. The starch granules on the independent protrusions can be easily cleaned, and it is not easy to leave food residues, which can ensure the good heat transfer performance of the protrusions.

[0112] like Fig.10 As shown, the connecting groove 307 has a groove bottom surface 313 (second smooth surface 310), and the connecting groove 307 has a groove side surface 303 formed by one side of the protrusion, and the groove side surface 303 extends in the depth direction of the connecting groove 307 and is inclined toward the outside of the width direction of the connecting groove 307. In this way, during the cleaning process, the cleaning tool can easily clean the food remaining in the independent groove, thereby reducing food residue.

[0113] The inclination angle of the groove side 303 cannot be too small, otherwise the groove cannot be manufactured and processed, and it is easy to hide dirt and is difficult to clean. The inclination angle of the groove side 303 should not be too large, otherwise the ability of the groove to store water or rice slurry will be reduced, resulting in the problem that rice is easy to stick and the non-stick performance is poor. When the groove depth h is less than 0.01, the volume of the groove is limited, thereby reducing the ability of the groove to store water or rice slurry; when the groove depth h is greater than 0.05mm, on the one hand, it is easy for the groove to hide dirt and on the other hand, it is easy to make the top of the protrusion or connecting rib 302 too thin, thereby causing the protrusion or connecting rib of the inner pot to be insufficiently strong and easy to wear.

[0114] The connecting groove 307 has a mouth width D1 and a bottom width D2, and the ratio of the mouth width to the bottom wall width is Wherein θ is the angle between the groove side surface 303 and the groove bottom surface 313 , and h is the height of the groove.

[0115] like Fig.11 As shown, there is an inclined angle θ between the outer inclined groove side surface 303 and the groove bottom surface 313, so that the groove is trumpet-shaped in the depth direction. In order to avoid a large difference between the groove mouth width and the bottom width, the angle θ is controlled between 90-150° and h is controlled between 0.01-0.05mm.

[0116] like Fig.12 As shown, the connecting groove 307 includes a cross-connecting portion 309, and the groove side 303 also has a first side 3031 and a second side 3032 located on the same protrusion, the first side 3031 and the second side 3032 are cross-connected at the cross-connecting portion 309, and the depth of the first side 3031 or the second side 3032 at the cross-connection is compared with the central depth of the connecting groove 307, and the ratio is: greater than or equal to 0.9 and less than 1.

[0117] The depth is close, and the rice slurry in the groove can flow smoothly, thereby improving the non-stick effect of rice.

[0118] In the second embodiment, Fig.11 As shown, the width dimension D3 of the protrusion 306 is 0.2-0.8 mm, and the width dimension D1 of the connecting groove 307 is 0.1-0.4 mm. During the flow of rice slurry, the heat of the protrusion 306 is easily taken away. In order to maintain a good heat transfer effect, preferably, the width of the protrusion 306 is set larger, and the width of the connecting groove 307 is less than 1 / 3 of the width of the protrusion 306.

[0119] During the processing, the grooves and protrusions 306 are first formed on the sheet and then stretched into the inner liner. Thus, the grooves or protrusions 306 on the side wall 32 of the inner liner and the grooves or protrusions 306 on the bottom wall 31 of the inner liner are different in appearance.

[0120] Specifically, the inner container includes an inner container bottom wall 31 and an inner container side wall 32. The connecting groove 307 of the inner container bottom wall 31 and the connecting groove 307 on the inner container side wall 32 are connected to each other, and the connecting groove 307 on the inner container side wall 32 is rhombus-shaped.

[0121] From a macroscopic perspective, the protrusion 306 on the inner pot side wall 32 is rhombus-shaped, and the connecting groove 307 next to the protrusion 306 is also rhombus-shaped. The angle between the first side surface 3031 and the second side surface 3032 may be greater than 90 degrees or may be less than 90 degrees. In any case, the rhombus-shaped connecting groove 307 can improve the smooth transportation of rice milk or water on the inner pot side wall 32 toward the inner pot bottom wall 31, thereby maintaining the non-stick performance at the inner pot bottom wall 31.

[0122] The inner liner also includes at least an aluminum layer 312 and a stainless steel layer 311, the stainless steel layer 311 and the aluminum layer 312 are combined to form a stainless steel composite plate, the stainless steel layer 311 has a bonding surface 305 combined with the aluminum layer 312, the bonding surface 305 includes a first bonding portion 3051 corresponding to the position of the connecting groove 307, and a second bonding portion 3052 corresponding to the protrusion 306, the ratio of the distance of the first bonding portion 3051 relative to the bottom wall of the groove to the distance of the second bonding portion 3052 relative to the upper surface of the protrusion 306 is greater than 0.95 and less than or equal to 1. The specific effect is described in Example 1. The roughness of the second smooth surface 310 and the first smooth surface 320 is Ra2-9μm.

[0123] In the present application, due to the existence of independent grooves, the depth h is 0.01 to 0.05 mm, and surface connecting ribs are provided between adjacent grooves. The size of general rice grains is 3-5 mm, so the existence of independent grooves can "suspend" the rice grains on the independent grooves, because the top surface of the connecting ribs is the first smooth surface, and the bottom surface of the independent grooves is the second smooth surface. The surface on which the rice grains are suspended and supported on the independent grooves is too smooth, and is affected by boiling during the cooking process and the influence of thermal convection. The position of the rice grains will not be restricted to a single independent groove, and can make irregular movements relative to the inner pot, realizing "activated" movement.

[0124] When cooking rice, due to the existence of the independent groove, the rice grains are suspended on the independent groove, and with the help of the first smooth surface, similar to a "rice grain activation suspension cabin". During the cooking process, the rice grains have a very small contact area with the inner pot, and the contact point is the first smooth surface. With the help of liquid boiling, high-temperature steam, etc., it is difficult for the rice grains to stick to the surface of the inner pot, thereby achieving the effect of non-stick rice.

[0125] Anything not described in this application can be achieved by adopting or drawing on existing technologies.

[0126] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0127] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A rice cooking utensil, comprising an inner pot formed by stretching a polished and embossed metal plate, the inner pot comprising a metal layer constituting an inner wall of the inner pot, the metal layer being provided with a plurality of independent grooves; characterized in that: The depth h of the independent groove is 0.01 to 0.05 mm, and surface connecting ribs are provided between adjacent grooves. The top surface of the connecting ribs is a first smooth surface, and the bottom surface of the independent groove is a second smooth surface.

2. A rice cooking utensil according to claim 1, characterized in that: The groove has a groove bottom surface, and the groove has a groove side surface formed by one side of the connecting rib. The groove side surface extends in the depth direction of the groove and is inclined toward the outside in the width direction of the groove.

3. A rice cooking utensil according to claim 2, characterized in that: The connecting rib includes an intersection, and the groove side also has a first side and a second side located in the same groove, the first side and the second side are connected at an angle at the intersection, and the depth of the first side or the second side at the intersection is compared with the center depth of the groove, and the ratio is greater than or equal to 0.9 and less than 1.

4. A rice cooking utensil according to claim 3, characterized in that: The shape and size of the groove on the metal plate is larger than the shape and size of the connecting rib.

5. The rice cooking utensil according to claim 2, characterized in that: The groove has a mouth width and a bottom width, and the ratio of the mouth width to the bottom wall width is Wherein θ is the angle between the groove side and the groove bottom; the angle θ is controlled between 90-150°.

6. The rice cooking utensil according to claim 2, characterized in that: The groove side surface and the groove bottom surface transition with an angle, and the groove side surface and the groove bottom surface are connected at the angle respectively.

7. The rice cooking device according to claim 1, characterized in that: The width of the connecting rib is 0.1-0.4 mm, the width of the groove is 0.2-0.8 mm, and the width of the connecting rib is less than 1 / 3 of the width of the groove.

8. The rice cooking utensil according to claim 1, characterized in that: The inner liner also includes at least an aluminum layer and a stainless steel layer, the stainless steel layer and the aluminum layer are combined to form a stainless steel composite plate, the stainless steel layer has a bonding surface combined with the aluminum layer, the bonding surface includes a first bonding portion corresponding to the position of the groove, and a second bonding portion corresponding to the connecting rib, and the ratio of the distance of the first bonding portion relative to the bottom wall of the groove to the distance of the second bonding portion relative to the upper surface of the connecting rib is greater than 0.95 and less than or equal to 1.

9. The rice cooking device according to claim 1, characterized in that: The surface roughness of the second smooth surface is Ra 2-9 μm.

10. The rice cooking device according to claim 1, characterized in that: The surface roughness of the first smooth surface is Ra 2-9 μm.

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