A uniform microwave heating device with a resonant field node resonator

Abstract

The present invention discloses a uniform microwave heating device with a resonant field node resonator, comprising a heating cavity, a waveguide connected to the lower end of the heating cavity, a tray installed in the heating cavity, an object to be heated is placed on the tray, a plurality of ferromagnetic material patches arranged in parallel are attached to the lower surface of the tray, the microwaves generated by the waveguide are transmitted to the heating cavity, a resonant field with nodes and antinodes is formed in the heating cavity, the ferromagnetic material patch is short-circuited with a resonator, the resonator is located at the node of the resonant field, and the field intensity of the resonant field near the tray is uniformed. The present invention only uses a simple plurality of strip-shaped ferromagnetic material patches and a resonator design at the tray to achieve the technical effect of generating a uniform field in the cavity and achieving uniform heating. It has very high practical value.

Description

Technical Field

[0001] The invention belongs to the technical field of microwave heating, and in particular relates to a uniform microwave heating device with a resonant field node resonator. Background Art

[0002] A microwave oven is an appliance that uses microwaves to heat food. It is widely used in households and the catering industry, mainly for heating, thawing and cooking food. Microwave ovens have the advantages of fast heating speed, energy saving and easy operation.

[0003] The working principle of microwave ovens is based on the generation and application of microwaves (frequency is usually 2.45 GHz). Microwaves are generated by a magnetron, and then sent into the heating cavity through a waveguide, forming resonance in the cavity, and quickly heating the object through interaction with the molecules of the substance (especially water molecules).

[0004] Due to the characteristics of microwaves, it is difficult for existing microwave ovens to obtain a uniform electromagnetic field, so it is difficult to obtain a uniform heating effect.

[0005] At present, some patents optimize the microwave distribution in the cavity by changing some components of the microwave oven. For example 1: CN202322800684.0 A glass structure that can improve the MW function. This patent improves the microwave energy distribution in the cavity by designing the bottom of the microwave oven. This utility model patent mainly involves a microwave oven substrate, which is a glass structure that improves the function of a microwave oven. It mainly includes a non-turntable microwave oven cavity with a glass substrate at the bottom. This glass substrate is located above the antenna and is square in shape, with four rounded corners. The bottom of the glass substrate is covered with a microwave reflection layer, which is formed by sintering at the bottom of the glass substrate, and the shape of this microwave reflection layer is different. The main advantage of this glass structure that can improve the function of a microwave oven is that by coating the bottom of the glass substrate with microwave reflection layers of different shapes, electromagnetic waves can be reflected, thereby changing the distribution of microwave energy in the cavity. This change can further improve the cooking performance of microwaves, increase the heating speed and thawing efficiency, thereby improving the microwave functional performance and the distribution of microwave energy, such as Figure 1As shown. Another example 2: CN202310016466.X A super-uniform heating microwave oven cavity based on a slot array antenna. This patent improves the microwave energy distribution in the cavity by designing a unique cavity shape. This invention is a microwave oven cavity based on a slot array antenna, which can achieve super-uniform heating effect. The cavity includes a cavity body, a cooking cavity is provided inside, and a magnetron and a waveguide located outside the cooking cavity. The cooking cavity consists of an inner cavity and an outer cavity, wherein the inner cavity is located inside the outer cavity and is hollow. A space band is provided between the outer wall of the inner cavity and the inner wall of the outer cavity, and this space band is used for the transmission of microwave energy. Some gaps are provided on the surface of the inner cavity, and these gaps are used to radiate microwave energy into the inner cavity. A slot antenna feeding port is provided at the bottom of the outer cavity, and this port is used to feed the microwaves generated by the magnetron into the outer cavity through the waveguide. The magnetron is located on the side of the outer cavity and is connected to the outer cavity of the microwave oven through the waveguide. A microwave outlet is provided at one end of the waveguide, which corresponds to the position of the slot antenna feed port. Figure 2 .

[0006] It can be seen that in the existing microwave heating technology, although there have been many designs trying to achieve heating uniformity through different internal structure improvements, there are still problems with high equipment complexity and high cost, such as including multiple microwave transmitters or complex reflection structures, which will increase manufacturing costs and maintenance difficulties. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a uniform microwave heating device with a resonant field node resonator in view of the above-mentioned existing deficiencies.

[0008] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0009] A uniform microwave heating device with a resonant field node resonator comprises a heating cavity, a waveguide is connected to the lower end of the heating cavity, a tray is installed in the heating cavity, an object to be heated is placed on the tray, a plurality of ferromagnetic material patches arranged in parallel are attached to the lower surface of the tray, microwaves generated by the waveguide are transmitted to the heating cavity, a resonant field with nodes and antinodes is formed in the heating cavity, the ferromagnetic material patches are short-circuited with the resonator, and the resonator is located at the node of the resonant field, so that the field intensity of the resonant field near the tray is uniform.

[0010] To optimize the above technical solutions, the specific measures taken also include:

[0011] The above-mentioned ferromagnetic material patches are strip-shaped patches, and the long sides of adjacent ferromagnetic material patches have slits.

[0012] The resonator is composed of a resonant ring and a connecting piece. One side of the resonant ring is fixedly connected to the lower end of the connecting piece, and the upper end of the connecting piece is short-circuited with the ferromagnetic material patch.

[0013] The above-mentioned resonant ring is a horizontal circular ring structure, and the connecting piece is a vertical rectangular piece.

[0014] The length of the resonator in the height direction is one quarter of the wavelength of the resonance field.

[0015] The number of the above-mentioned resonators is two, which are symmetrically arranged in the heating cavity.

[0016] The placement direction of the above-mentioned resonator, that is, the direction of the resonant ring diameter line passing through the connection between the connecting plate and the resonant ring, is parallel to the slit of the ferromagnetic material patch.

[0017] The above-mentioned tray is arranged in the middle position of the heating cavity. The tray is a rectangular metal tray. The four sides of the tray are sealed with the four walls of the inner cavity of the heating cavity. A slender gap structure is opened at the connection between the long side of the tray and the four walls of the inner cavity of the heating cavity. The resonant field can exist in the space above and below the tray through the slender gap structure.

[0018] Each long side of the above-mentioned tray is respectively provided with two elongated gap structures, and the elongated gap structures between the long sides are symmetrically arranged.

[0019] The above-mentioned heating cavity is a closed cavity, and the inner wall of the heating cavity is a metal wall.

[0020] The beneficial effects of the present invention are:

[0021] (1) The present invention has a simple structure and low cost. The present invention only uses a simple plurality of strip-shaped ferromagnetic material patches and a resonator design at the tray to achieve the technical effect of generating a uniform field in the cavity and achieving uniform heating, and has a very high practical value.

[0022] (2) There are obvious strong field areas and weak field areas in the inner cavity of a traditional microwave oven, resulting in uneven heating. The present invention sets a resonator at the node of the resonance field to eliminate the node characteristics of the resonance field, that is, the difference in field strength between each block is reduced, and there is no obvious weak field strength area, thereby achieving the technical effect of uniform heating.

[0023] (3) The present invention provides a ferromagnetic material patch on the lower surface of the tray, which can form a uniform electromagnetic field in conjunction with the resonator. The ferromagnetic material patch will affect the formation of the standing wave field in the cavity. Only by using multiple ferromagnetic material patches arranged in parallel and cooperating with the resonator can a uniform electromagnetic field be formed. If a whole ferromagnetic material is used, a similar uniform field cannot be generated when the resonator is also applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1This is a schematic diagram of a glass structure that can improve MW function in the prior art patent CN202322800684.0;

[0025] Figure 2 This is a schematic diagram of a super-uniform heating microwave oven cavity based on a slot array antenna in the prior art patent CN202310016466.X ( Figure 1 , 2 The reference numerals in the figure represent the reference numerals of the two prior art patents respectively, and are not the reference numerals of the structure of the present invention);

[0026] Figure 3 It is a structural schematic diagram of the present invention;

[0027] Figure 4 It is a structural position diagram of the heating cavity of the present invention, wherein the purple part is the heating cavity;

[0028] Figure 5 It is a structural position diagram of the waveguide of the present invention, wherein the purple part is the waveguide;

[0029] Figure 6 It is a structural position diagram of the resonator of the present invention, wherein the purple part is the resonator;

[0030] Figure 7 It is a schematic diagram of the structure of the resonator of the present invention;

[0031] Figure 8 It is a structural position diagram of the tray of the present invention, wherein the purple part is the tray;

[0032] Fig. 9 It is a structural schematic diagram of the tray of the present invention;

[0033] Fig.10 It is a structural position diagram of the ferromagnetic material patch of the present invention, wherein the purple part is the ferromagnetic material patch;

[0034] Fig.11 It is a structural position diagram of a single ferromagnetic material patch;

[0035] Fig.12 This is a magnetic field distribution diagram at the tray when the ferromagnetic material patch and the resonator are not optimized in the prior art;

[0036] Fig.13 The magnetic field distribution diagram at the tray after adding ferromagnetic material patches and resonators to the present invention;

[0037] Figure 3 , 7 The meanings of the symbols in the drawings in 9 are: heating cavity 1, waveguide 2, tray 3, slender gap structure 31, ferromagnetic material patch 4, resonator 5, resonant ring 51, connecting plate 52. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0039] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0040] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0041] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or units (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" / "several" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0042] like Figure 3 As shown, the complete three-dimensional structure of the present invention includes a heating cavity 1, a waveguide 2, a tray 3, a ferromagnetic material patch group and a resonator 5.

[0043] The heating chamber 1 is a relatively large hexahedron made of stainless steel.

[0044] The waveguide 2 is a common rectangular waveguide on the market, which is placed at the center just below the heating cavity 1 and is made of stainless steel.

[0045] The tray 3 is a metal tray, which is placed horizontally in the heating cavity 1 to divide the heating cavity 1 into two upper and lower areas. A plurality of rectangular strip-shaped ferromagnetic material patches 4 are placed directly below the tray 3 .

[0046] There are two resonators 5, which are relatively small in size and consist of a resonant ring 51 and a strip-shaped protruding connecting piece 52 located at the corner of the resonant ring 51 and perpendicular to the corner of the resonant ring 51. The connecting piece 52 is vertically arranged, the lower end is integrally formed or welded with the resonant ring 51, and the upper end is connected to the ferromagnetic material patch 4.

[0047] like Figure 4As shown, the metal wall of the heating cavity 1 can effectively reflect microwaves, ensuring that microwaves circulate inside the cavity, continuously penetrate and heat the food, thereby improving the heating efficiency. Through repeated reflection of microwaves, the microwave field distribution in the cavity is more uniform, which helps the food to achieve uniform temperature distribution during the heating process. The heating cavity 1 is completely sealed to prevent microwaves from leaking into the external environment and ensure the safety of the user.

[0048] like Figure 5 As shown, the waveguide 2 can adopt a low-cost WR430 rectangular waveguide, which is used to transmit the microwaves generated by the front microwave generating device (such as a magnetron) to the heating cavity 1, which helps to control and adjust the distribution of microwave energy entering the heating cavity 1, and can also protect the magnetron from erosion by food steam and grease.

[0049] like Figure 6 As shown, the resonator 5 is arranged below the ferromagnetic material patch 4 at the node of the resonance field, so that the placement direction of the resonator 5 (i.e. the direction of the resonance ring diameter line passing through the connection between the connecting piece and the resonance ring) is parallel to the slit of the ferromagnetic material patch 4. By determining the field strength of the node and the antinode (the optimal value is equal), the size of the resonator 5 is adjusted, and finally the field strength near the tray 3 is uniformed.

[0050] like Figure 7 As shown, the connecting piece 52 has a height of 4 mm and a width of 2 mm, and the outer diameter of the resonant ring 51 is about 16 mm and the inner diameter is about 15 mm.

[0051] The length of the resonator 5 in the height direction, that is, the height of the combination of the resonant ring 51 and the connecting plate 52, is one quarter of the wavelength of the resonant field (2.45GHz). The resonator 5 can adjust the distribution of the electromagnetic field in the cavity so that the microwave energy is evenly distributed in the heating cavity, so that the food can be heated more evenly.

[0052] like Figure 8 and 9 As shown, the tray 3 is located in the center of the cavity for carrying heated food. The four sides of the tray 3 are sealed with the four walls of the inner cavity of the heating cavity 1, and the long side of the tray 3 is provided with four elongated gap structures 31, so that the electromagnetic field can exist in the upper and lower spaces of the tray 3.

[0053] like Fig.10 and 11 As shown, the ferromagnetic material patch 4 is a strip patch, and the long sides of adjacent ferromagnetic material patches 4 are close to each other, but have a slit. The ferromagnetic material patch 4 must be matched with multiple ferromagnetic material patches arranged in parallel, and cannot be replaced by a whole ferromagnetic material. If a whole ferromagnetic material is used, similar resonator 5 cannot be produced. Fig.13 The uniform field is shown.

[0054] like Fig.12 As shown, in the prior art, when the ferromagnetic material patch 4 and the resonator 5 are not optimized, the magnetic field distribution at the tray 3 has obvious strong field areas and weak field areas, and the heating is uneven. The dotted box is the node area of ​​the field, that is, the area where the resonator 5 is set.

[0055] After the ferromagnetic material patch 4 and the resonator 5 are added to the present invention, the magnetic field distribution at the tray 3 is as follows: Fig.13 As shown in the figure, the node characteristics disappear in the dotted box area, that is, the difference in field strength between each block decreases, and there is no obvious weak field strength area, which can achieve uniform heating ( Fig.12 and Fig.13 The vertical coordinate H Field is the magnetic field intensity).

[0056] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A uniform microwave heating device with a resonant field node resonator, comprising a heating cavity (1), wherein the lower end of the heating cavity (1) is connected to a waveguide (2), wherein: A tray (3) is installed in the heating cavity (1), and the object to be heated is placed on the tray (3). A plurality of ferromagnetic material patches (4) arranged in parallel are attached to the lower surface of the tray (3). The microwaves generated by the waveguide (2) are transmitted to the heating cavity (1), and a resonant field having wave nodes and wave antinodes is formed in the heating cavity (1). The ferromagnetic material patches (4) are short-circuited with a resonator (5), and the resonator (5) is located at the wave node of the resonant field, so that the field intensity of the resonant field near the tray (3) is uniform. The ferromagnetic material patches (4) are strip-shaped patches, and the long sides of adjacent ferromagnetic material patches (4) have slits. The resonator (5) is composed of a resonant ring (51) and a connecting piece (52); one side of the resonant ring (51) is fixedly connected to the lower end of the connecting piece (52); the upper end of the connecting piece (52) is short-circuited with the ferromagnetic material patch (4); the tray (3) is arranged in the middle of the heating cavity (1); the tray (3) is a rectangular metal tray; the four sides of the tray (3) are sealed to the four walls of the inner cavity of the heating cavity (1); a slender gap structure (31) is provided at the connection between the long side of the tray (3) and the four walls of the inner cavity of the heating cavity (1); and the resonant field can exist in the upper and lower spaces of the tray (3) through the slender gap structure (31).

2. The uniform microwave heating device with a resonant field node resonator according to claim 1, characterized in that: The resonant ring (51) is a horizontal circular ring structure, and the connecting piece (52) is a vertical rectangular piece.

3. The uniform microwave heating device with a resonant field node resonator according to claim 2, characterized in that: The length of the resonator (5) in the height direction is one quarter of the wavelength of the resonance field.

4. The uniform microwave heating device with a resonant field node resonator according to claim 3 is characterized in that: The number of the resonators (5) is two, which are arranged symmetrically in the heating cavity (1).

5. The uniform microwave heating device with a resonant field node resonator according to claim 3, characterized in that: The placement direction of the resonator (5), that is, the direction of the diameter line of the resonant ring (51) passing through the connection between the connecting piece (52) and the resonant ring (51), is parallel to the slit of the ferromagnetic material patch (4).

6. The uniform microwave heating device with a resonant field node resonator according to claim 5, characterized in that: Each long side of the tray (3) is respectively provided with two elongated gap structures (31), and the elongated gap structures (31) between the long sides are symmetrically arranged.

7. The uniform microwave heating device with a resonant field node resonator according to claim 1, characterized in that: The heating cavity (1) is a closed cavity, and the inner wall of the heating cavity (1) is a metal wall.

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