RU2803239C2 - Food cooking device containing heating element in lid - Google Patents

Abstract

FIELD: cooking.

SUBSTANCE: cooking device (100) having lid (10) and inner bowl (20) forming cooking space (22) to accommodate food material. Cover (10) is located above inner bowl (20) with the possibility of movement between the closed position and the open position. Cover (10) contains heating unit (1) including heating device (11, 12), reflective plate (13) and light-transmitting plate (14) located under reflective plate (13), while reflective plate (13) and light-transmitting plate (14) determine the heating space in which heating device (11, 12) is placed. Heating device (11, 12) contains first heating tube (11) and second heating tube (12), each heating tube has a semi-closed shape with passage (111, 121), first heating tube (11) being surrounded by second heating tube (12), and the passage of first heating tube (11) is located so that it faces the body of the second heating tube without a passage. Reflective plate (13) contains a reflection enhancement zone located between first heating tube (11) and second heating tube (12), and the reflection enhancement zone is configured to enhance the reflection of radiation from both first heating tube (11) and second heating tube (12).

EFFECT: uniform heating of the cooking space.

12 cl, 5 dwg

Description

Field of technology to which the invention relates

The invention relates to the field of food preparation devices, namely to a multicooker with baking or grilling functions.

State of the art

To meet the varied cooking needs of people and save space in the kitchen, multi-cookers are one of the fastest growing electrical appliances. They are widely used to prepare various foods such as rice, beans and even muffins. A multicooker typically includes an inner bowl defining a cooking space and a lid positioned over the inner bowl and movable between a closed position and an open position. If the multicooker is intended to serve baking or grilling functions, the lid may contain a top heating block in addition to the heating plate typically provided at the bottom of the cooking space to also heat the food material from above.

Existing top heating blocks often contain a single heating tube, such as a far infrared heating tube. The heating tube is a tubular electric heating element that converts electrical energy into heat based on the Joule effect. Typically, the heating tube contains a metal filament enclosed in a sheath. When powered by electricity, the metal filament generates radiation of certain wavelengths. Such heating tubes are known in the art and are widely used as a heating device in electric stoves. However, due to the location of the metal filament in the heating tube, heating the ends of the heating tubes is often difficult. The so-called cold end causes uneven heating of the food material in the cooking space, resulting in poor cooking results. In addition, with this arrangement, the space directly below or adjacent to the far-infrared heating tube heats up quickly, while the space away from the heating tube receives less heat and the temperature rises slowly. In other words, the existing top heating block cannot provide uniform heating either horizontally or in three dimensions.

Disclosure of the invention

To solve at least some of the above problems, the invention provides a multicooker with a heating block that is more efficient and provides uniform heating of the cooking space.

In particular, the invention relates to a food preparation device having a lid and an inner bowl defining a cooking space for receiving food material, the lid being disposed over the inner bowl and being movable between a closed position and an open position, the lid comprising a heating block including a heating element. a device, a reflective plate and a light transmitting plate located below the reflective plate, wherein the reflective plate and the light transmitting plate define a heating space in which the heating device is located, wherein the heating device includes a first heating tube and a second heating tube, each heating tube having a semi-closed shape with passage, wherein the first heating tube is surrounded by a second heating tube, and the passage of the first heating tube is positioned to face the body of the second heating tube without a passage, wherein the reflection plate includes a reflection enhancement zone located between the first heating tube and the second heating tube , wherein the reflection enhancement zone is configured to enhance the reflection of radiation for both the first heating tube and the second heating tube.

The heating device according to the present invention contains two heating tubes, which can be more powerful than a single heating tube. The general shape of each heating tube is a semi-closed shape with a passage, such as a C-shape or a U-shape, or even a rectangular shape with a passage on one side. The electrical terminals are located in the said passage. As described in the Background Art section, the passage is the cold end of the heating tube. By positioning the first heating tube surrounded by the second heating tube so that its passage faces the body of the second heating tube, the reduction in radiation at the cold end of the first heating tube is compensated by the second heating tube. Preferably, the passage of the first heating tube is located so that it faces the main part of the second heating tube opposite its passage. In other words, the passages of the first and second heating tubes are located opposite each other so that each cold end is compensated by the other heating tube. In this way, the overall radiation of the heating device is uniform to improve the temperature uniformity in the cooking space.

Further, by “transmitting plate” is meant a plate that allows at least a portion of the radiation generated by the heating tubes to pass through. Depending on the wavelengths of radiation generated by the heating tubes, the light transmitting plate may or may not be transparent to visible light. The light-transmitting plate is located to partially limit the cooking space. In other words, the radiation generated by the heating tubes passes through the light transmission plate and directly enters the cooking space.

The reflective plate and the light transmitting plate together form a heating space in which the heating device is housed. The heating block is fixed in the multicooker lid. When the cover is open, the light transmitting plate is visible from the bottom of the cover. It is understood that the light transmitting plate defines the bottom wall of the heating space. The reflection plate preferably includes an upper wall and a side wall, which respectively constitute an upper wall and a side wall of the heating space. The inner surface of the reflective plate is capable of reflecting and/or scattering radiation generated by the heating tubes. In fact, the heating tube emits radiation in all directions around it. The function of the reflective plate is to redirect the emitted radiation upward or sideways and downward to enter the cooking space. The reflective plate increases the thermal efficiency of the heating tubes. In addition, the scattering effect ensures better radiation uniformity.

In addition, the reflection plate includes a reflection enhancement zone located between the first heating tube and the second heating tube, and the reflection enhancement zone is configured to enhance the reflection of radiation for both the first heating tube and the second heating tube. In particular, the location and shape of the reflection enhancement zone is carefully selected by the inventors through experiments and simulations. Compared with the flat surface that could be provided as the inner surface of the reflection plate, the reflection enhancement zone according to the present invention can further enhance the reflection and/or scattering of radiation generated by both heating tubes to improve thermal efficiency and radiation uniformity.

Thus, the cooking apparatus of the present invention can overcome the disadvantages of the existing lid heating unit and improve the heating uniformity in the cooking space.

The food preparation device according to the present invention may further comprise the following features, individually or together:

- the first and second heating tubes are far infrared heating tubes. The far infrared heating tube has the advantages of high intensity, high thermal efficiency, high penetration and low energy consumption.

- the first and second heating tubes are C-shaped. The heating tube may also have other semi-closed shapes, such as U-shape, oval or rectangular shape with a passage, and others, depending on the shape of the cap and its aesthetic design.

- the first and second heating tubes are attached to the reflective plate, for example, by means of clamps or brackets. It is preferable to leave a vertical distance between the reflection plate and the heating tubes to ensure better reflection effect and avoid the need for thermal insulation between them.

- the light transmitting plate is sealed by the lower end of the reflective plate by means of a peripheral seal. Since the multicooker may have the function of cooking food material with water, steam may be generated inside the cooking space. Thus, it is preferable to seal a heating block that is electrically powered.

- the light transmitting plate is made of glass, such as glass ceramics or tempered glass. The glass allows at least a portion, and preferably a majority, of the radiation emitted by the heating tubes to pass through. However, it may be opaque or translucent to visible light, so that the user cannot see the heating tubes located within the heating space, leaving more freedom to the multicooker designer. The light transmitting plate can also be made of transparent plastic.

- the light-transmitting plate contains an upper surface facing the heating space and a lower surface facing the cooking space, while the light-transmitting plate contains a reflective layer located on the upper surface and/or the lower surface. In this preferred embodiment, the radiation emitted by the heating tubes is reflected between the reflection plate and the reflective layer of the light transmission plate to reduce the proportion of radiation that passes directly through the light transmission plate, which will increase the temperature of some individual areas. Thus, the temperature difference between different areas of the light transmission plate is reduced, and the light transmission plate is heated more evenly. Consequently, the food material in the cooking space is also heated more evenly.

- the reflection enhancement zone includes two projections extending downward from the top wall of the reflective plate and both located between the first heating tube and the second heating tube. The projections provide a large reflective surface area, which further improves the reflection and dispersion of radiation emitted by the heating tubes. The surfaces of the two projections are located between the first and second heating tubes so that they can serve both heating tubes.

- if the first and second heating tubes are C-shaped, the projections are arched and located opposite each other. The curve of the protrusions follows the curve of the heating tubes, which allows for as much additional reflection/scattering surface as possible.

- the reflection enhancement zone comprises a convex surface located between the first heating tube and the second heating tube, the convex surface further comprising a plurality of embossings. The embossing forms a rough surface, which provides a better dissipation effect of the radiation emitted by the heating tubes.

- embossings are evenly distributed on the convex surface. This arrangement allows scattered radiation to be uniformly reflected towards the light-transmitting plate.

- the cover contains a steam channel connecting the cooking space and the outside of the cooking device, and the reflective plate contains a mounting hole made to receive and accommodate the steam channel, and the mounting hole is located so as to pass through the passage of the first heating tube or the second heating tube. Thus, the steam channel is located at the passage, that is, at the cold end of one of the heating tubes, where the temperature rise is lowest. This arrangement prevents overheating of parts inside the heating space and provides increased safety.

Brief description of drawings

Fig. 1 is a schematic cross-sectional view of a multicooker according to one embodiment of the invention;

Fig. 2 is an enlarged cross-sectional view of the heating block shown in FIG. 1;

Fig. 3 is a schematic bottom view of the heating block shown in FIG. 1, without light transmitting plate;

Fig. 4 is a perspective view of the heating block of FIG. 1 disassembled;

Fig. 5 is a sectional view of a heating block according to another embodiment.

Detailed Description of the Invention

Exemplary embodiments, which are illustrated in the accompanying drawings, are described in detail below. In the following description of the figures, unless otherwise indicated, like numbers in different figures refer to the same or similar elements. The implementation methods described in the following exemplary embodiments do not represent all implementation methods in accordance with the invention. Instead, they are only examples of devices in accordance with certain aspects of the invention as described in detail in the accompanying claims.

The terms used in the application are used only for the purpose of describing specific embodiments and are not intended to be limiting. The singular forms "one" and "said" used in the specification and appended claims are also intended to include the plural form unless the context clearly indicates otherwise. It should also be understood that the term “and/or” as used herein means and includes any and all possible combinations of one or more related listed elements.

It should be understood that although the application may use terms such as “first,” “second,” and “third” to describe various pieces of information, those pieces of information are not limited to these terms. These terms are used only to distinguish information of the same type. For example, without departing from the scope of the invention, the first element of information may also be referred to as the second element of information. Likewise, the second information element may be referred to as the third information element. Depending on the context, such as the terms used herein, “if” may be interpreted as “when...” or “in the event that...” or “in response to a determination that...”.

In fig. 1 shows a food preparation device 100 according to one embodiment of the invention. The cooking device 100, for example, is powered by electricity and can perform various cooking functions such as cooking rice, cooking soy milk, and especially cake baking or grilling. Thus, the cooking device 100 is also called a multicooker. As in a conventional structure, the cooking apparatus 100 includes a housing 30 and a lid 10 that is hinged to the upper end of the housing 30. The inner bowl 20 is movably positioned within the housing 30 and defines a cooking space 22 housing the food material to be cooked. The lid 10 is movable between a closed position in which it covers the cooking space 22 and an open position in which it leaves the cooking space 22 accessible from the outside. In fig. 1 cover 10 is in the closed position. In fig. 1 also shows that the lid 10 includes a heating block 1 and a steam path 50, which are described below.

The heating block 1 is shown more clearly in FIG. 2-4. In particular, the heating block 1 contains two heating tubes 11, 12 forming a heating device. The heating block 1 also includes a reflective plate 13 and a light transmitting plate 14 located below the reflecting plate 13. The reflecting plate 13 and the light transmitting plate 14 define a heating space in which the heating device, that is, the first heating tube 11 and the second heating tube 12, is located. the tube 11 and the second heating tube 12 are attached to the reflective plate 13 by means of clamps 138.

As shown in FIG. 2 and 4, the reflection plate 13 includes a top wall 130 and a side wall 132 extending downward from the top wall 130 and including a flange 134. The top wall 130 and the side wall 132 of the reflection plate 13 constitute the top wall and the side wall of the heating space, respectively. In this embodiment, the light transmission plate 14 is a substantially flat piece that is clamped to the flange 134 of the reflection plate 13 and sealed with a peripheral sealing member (not shown). The light transmitting plate 14 constitutes the bottom wall of the heating space and is in direct contact with the cooking space 22.

In this embodiment, both heating tubes 11, 12 are far-infrared heating tubes, each comprising a metal filament 124 enclosed within a tubular sheath 125. The first heating tube 11 is supplied with electricity through terminals 114 that extend upward from the plane of the first heating tube. 11. It is known that the heating effect on the 114 terminals is not as good as other parts of the filament. As shown in FIG. 3 and 4, the first heating tube 11 has an annular shape with a passage 111, thus forming an overall semi-closed shape. Both terminals 114 are located in the passage 111, which forms the so-called cold end. The first heating tube 11 is surrounded by a second heating tube 12 located in the same plane. The second heating tube 12 has the same general shape as the first heating tube 11, but with a larger diameter.

In accordance with the invention, the passage 111 or the cold end of the first heating tube 11 is located so that it faces the main part 122 of the second heating tube 12, which is therefore not the passage 122 of the second heating tube 12. At the same time, the passage 121 the second heating tube 12 is also positioned to face the body 112 of the first heating tube 11. Thus, the cold end of each heating tube is radially adjacent to the body of the other heating tube, thereby compensating for the reduced heating effect due to the presence of the cold end. Thus, the overall heating effect is uniform to a certain extent. In this embodiment, the passage 111 of the first heating tube 11 is located opposite the passage 121 of the second heating tube 12. In other words, the two passages 111, 121 are diametrically opposed. However, if necessary, the passages can be located at a non-zero angle.

As shown in FIG. 2-4, the upper wall 130 of the reflective plate 13 includes two projections 131 extending downward into the heating space and located between the first heating tube 11 and the second heating tube 12. When viewed from above or below, each projection 131 has an arcuate shape that extends along the annular body. first and second heating tubes. The two projections 131 constitute a reflection enhancement zone according to the present invention, which is configured to enhance the radiation reflection of both the first heating tube 11 and the second heating tube 12. In fact, as best shown in FIG. 2, the vertical section of the protrusion 131 is defined by a curve whose lowest point is located in the middle part of the curve. Since the protrusion 131 is located radially between the first heating tube 11 and the second heating tube 12, its curved surface has two portions 136, 137, respectively, generally facing the first and second heating tubes. A portion 136 extends from the general plane of the top wall 130 to the lowest point of the curve and is thus oriented to face the first heating tube 11 so as to form a reflective surface for the first heating tube 11. Likewise, a portion 137 extends from the lowest point curve to the general plane of the top wall 130 and is thus oriented to face the second heating tube 12 so as to form a reflective surface for the second heating tube 12. Thus, the radiation emitted by the heating tubes 11, 12 is better scattered by the projections 131 Additionally, during actual use of the multicooker 100, it is possible that only one heating tube will be energized for certain functions or scenarios. The projections 131 in this embodiment are capable of enhancing the reflection of radiation emitted by each of the heating tubes, thereby providing a highly ductile structure.

The reflection plate 13 is made of a reflective material such as stainless steel, preferably treated with a mirror polish. Alternatively, the inner surface of the reflection plate 13 may be coated with a reflective layer such as silver paper or aluminum foil. The inner surface includes the inner surface of the top wall 130, the side wall 132 and the projections 131. These embodiments are preferred because they can improve the reflection of radiation emitted by the heating tubes and thus improve the thermal efficiency of the heating block.

The light transmitting plate 14 is made of glass, such as glass ceramic or tempered glass. In a further preferred embodiment not shown in the figures, the top surface 141 and/or the bottom surface 142 of the light transmitting plate 14 is also provided with a reflective layer that is printed or electroplated on one or both surfaces. When the far infrared light reaches the light transmitting plate 14, it is blocked or attenuated by said reflective layer. Thus, the far-infrared light is reflected between the reflection plate 13 and the reflective layer of the light transmission plate 14, so that the entire light transmission plate 14 is evenly heated. Thus, the temperature difference of different parts of the light transmission plate 14 is reduced, so that the cooking space is evenly heated through the surface of the light transmission plates 14. Thus, the cooking effect is improved.

In fig. 1 to 4, it can also be seen that the heating block 1 includes a mounting hole 16 through which the steam path 50 passes. More specifically, the reflection plate 13 includes an upper hole 133, and the light transmission plate 14 includes a lower hole 143 at a corresponding location. In this embodiment, the mounting hole 16 extends through the passage 121 of the second heating tube 12. Thus, the steam path 50 is located at the passage, that is, at the cold end of the second heating tube, where the temperature rise is lowest. This arrangement prevents overheating of parts inside the heating space and provides increased safety.

The embodiment shown in FIG. 5 is very similar to the embodiment described above, except that the convex surface of the projections 131 is further provided with a plurality of embossings 139. The embossings 139 are evenly spaced and form a rough surface of the convex surface, which thus provides a better scattering effect of the radiation emitted by the heating elements. tubes. However, it should be noted that the reflection enhancement region does not necessarily include two arcuate projections 131 as shown in FIG. 5 and 3, but may also have other shapes in the top view. The convex surface of the reflection enhancement zone may also differ from the shape shown in FIG. 2, provided that it is capable of improving the reflection of radiation emitted by both the first and second heating tubes. In particular, the convex surface may comprise two portions facing the first and second heating tubes, respectively.

The description above is provided only to describe preferred embodiments of the invention and is not intended to limit the invention. When there is no conflict, the above-described embodiments can be combined with each other. Any modification, equivalent replacement or improvement made within the spirit and principles of the invention falls within the scope of protection of the invention.

For example, the heating block may contain more than two heating tubes, which may be of a type other than the far infrared type. The reflection enhancement region may have other shapes, such as a plurality of embossings formed directly on the inner surface of the reflection plate. The light transmitting plate can be made of transparent plastic.

Claims (12)

1. A food preparation device (100) having a lid (10) and an inner bowl (20) defining a cooking space (22) to receive food material, the lid (10) being located above the inner bowl (20) so that it can be moved between the closed position and an open position, while the cover (10) contains a heating block (1), including a heating device (11, 12), a reflective plate (13) and a light transmitting plate (14) located under the reflective plate (13), while the reflective a plate (13) and a light transmitting plate (14) define a heating space in which a heating device is located, the heating device comprising a first heating tube (11) and a second heating tube (12), each heating tube having a semi-closed shape with a passage (111, 121), wherein the first heating tube (11) is surrounded by a second heating tube (12), and the passage of the first heating tube (11) is positioned to face the main part of the second heating tube without a passage, wherein the reflecting plate (13) contains a reflection enhancement zone located between the first heating tube (11) and the second heating tube (12), wherein the reflection enhancement zone is configured to enhance the reflection of radiation for both the first heating tube (11) and the second heating tube (12), wherein the reflection enhancement zone comprises two projections (131) extending down into the heating space and located between the first heating tube (11) and the second heating tube (12). 2. The cooking apparatus according to claim 1, wherein the first and second heating tubes are far-infrared heating tubes. 3. The cooking apparatus according to claim 1, wherein the first and second heating tubes are each C-shaped. 4. The cooking device according to claim 1, wherein the first and second heating tubes are attached to the reflection plate (13). 5. The cooking device according to claim 4, wherein the first and second heating tubes are attached to the reflective plate (13) by means of clamps. 6. The cooking device according to claim 1, wherein the light transmitting plate (14) is sealed with the lower end of the reflecting plate (13) by a peripheral seal. 7. The cooking device according to claim 1, in which the light transmitting plate (14) is made of glass. 8. The cooking device according to claim 1, wherein the light transmitting plate (14) includes an upper surface (141) facing the heating space and a lower surface (142) facing the cooking space, wherein the light transmitting plate (14) contains a reflective layer located on the upper surface (141) and/or the lower surface (142). 9. The cooking device according to claim 1, wherein the first and second heating tubes are C-shaped, each protrusion (131) being arc-shaped and positioned opposite each other. 10. The cooking device according to claim 1, wherein the reflection enhancement zone comprises a convex surface located between the first heating tube (11) and the second heating tube (12), the convex surface further comprising a plurality of embossings (139). 11. The cooking device according to claim 10, wherein the embossings (139) are uniformly distributed on the convex surface. 12. The cooking device according to claim 1, in which the lid contains a steam channel (50) connecting the cooking space and the outer part of the cooking device, and the reflective plate (13) contains a mounting hole (16) designed to receive and accommodate the steam channel (50), wherein the mounting hole (16) is located so as to pass through the passage (111, 121) of the first heating tube (11) or the second heating tube (12).