Door body assembly and cooking equipment

Abstract

The invention discloses a door body assembly which comprises a door body, the inner surface, facing an inner container, of the door body is provided with a sunken part which extends along the edge of the door body and forms an enclosure, a plurality of layers of choke plates which are mutually spaced in the thickness direction of the door body are arranged in the space corresponding to the sunken part, and gaps are formed in the peripheries of the choke plates and the sunken part. Tooth grooves are formed in the edge of the choke plate at intervals, and choke teeth are formed in the portions, between the adjacent tooth grooves, of the choke plate; the space corresponding to the concave part is located between the two adjacent choke plates, a plurality of choke grooves which are mutually spaced in the thickness direction of the door body are formed between the bottom of the concave part and the choke plate closest to the concave part, and the depth of each choke groove from the inner periphery to the outer periphery is matched with the wavelength of the corresponding microwave; each choke slot is adapted to shield a corresponding microwave. The invention further discloses cooking equipment. The microwave shielding device has the beneficial effect of being capable of efficiently shielding microwaves with various frequencies.

Description

Technical Field

[0001] This invention relates to a door assembly and a cooking device, belonging to the technical field of microwave shielding for cooking devices. Background Technology

[0002] In microwave cooking equipment, the door assembly is a key component for preventing microwave energy leakage. Current technology commonly uses choke grooves on the inner surface edge of the door to achieve microwave shielding. Especially to address the shielding requirements of two different microwave frequencies, a common approach is to alternately distribute two types of choke grooves of different depths along the extension direction of the recess to resonate and match the target frequency. However, this alternating distribution structure has significant drawbacks: First, the alternating arrangement of choke grooves of different depths within the door edge plane occupies a large space, hindering the narrowing design of the door frame; more importantly, the alternating distribution pattern creates physical gaps or structural discontinuities at the junctions of different choke grooves. These locations can easily become weak points or "blind spots" for microwave energy leakage, leading to a localized decrease in shielding effectiveness and posing safety hazards. Furthermore, traditional choke groove structures with a single depth and width are highly frequency sensitive, effective only within a very narrow frequency band, and have poor shielding effects against frequency drift or higher harmonics. Summary of the Invention

[0003] The purpose of this invention is to provide a door assembly and cooking equipment that can efficiently shield microwaves of multiple frequencies.

[0004] The present invention is achieved through the following technical solution.

[0005] A door assembly includes a door body, the inner surface of the door body facing the inner liner having a recess extending along its edge and forming an enclosure, a space corresponding to the recess having multiple layers of chokes spaced apart from each other in the thickness direction of the door body, a gap between the chokes and the periphery of the recess, the chokes having spaced-apart grooves along their edges, and the portion of the chokes between adjacent grooves forming choke teeth.

[0006] The space corresponding to the recessed portion has multiple choke slots spaced apart from each other in the thickness direction of the door body, formed between two adjacent choke plates, at the bottom of the recessed portion and between the nearest choke plate. The depth of each choke slot from the inner perimeter to the outer perimeter is matched with the corresponding microwave wavelength, so that each choke slot is suitable for shielding the corresponding microwave.

[0007] As a further improvement of the present invention, the depth of each choke groove gradually decreases along the direction from away from to near the bottom of the recess.

[0008] As a further improvement of the present invention, the length of the slot teeth of each choke gradually decreases along the direction from away from to near the bottom of the recess.

[0009] As a further improvement of the present invention, the width of the choke teeth of each choke plate gradually decreases along the direction from away from to near the bottom of the recess.

[0010] As a further improvement of the present invention, at least a portion of the choke groove is configured such that the choke groove varies in a stepped manner along its depth direction, so as to form a multi-level impedance gradient within the choke groove.

[0011] As a further improvement of the present invention, the choke groove with a stepped width is formed from the inner perimeter to the outer perimeter as a relatively wide broadband matching section and a relatively narrow harmonic suppression section.

[0012] As a further improvement of the invention, the width variation of the choke groove along its depth direction is provided by the choke plate to which it belongs.

[0013] As a further improvement of the present invention, a first choke plate relatively far from the bottom of the recess and a second choke plate relatively close to the bottom of the recess are provided in the space corresponding to the recess. Furthermore, a first choke groove is formed between the first choke plate and the second choke plate, and a second choke groove is formed between the second choke plate and the bottom of the recess in the space corresponding to the recess.

[0014] As a further improvement of the present invention, the first choke slot is used to shield microwaves of 902 MHz - 928 MHz, and the second choke slot is used to shield microwaves of 2400-2500 MHz.

[0015] A cooking appliance, including a door assembly.

[0016] The beneficial effects of this invention are:

[0017] By arranging the choke grooves in layers along the thickness of the door, the shielding structures for different frequencies almost completely overlap and cover each other in the projection, eliminating any possible straight leakage paths. This achieves continuous and uniform microwave protection for the entire edge of the door without any blind spots, significantly improving the overall shielding effectiveness and reliability. Attached Figure Description

[0018] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings to aid in understanding the objectives and advantages of the present invention, wherein:

[0019] Figure 1 This is a structural schematic diagram of the door assembly;

[0020] Figure 2 This is a cross-sectional view of the door assembly. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0022] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the construction shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0023] Implementation method 1:

[0024] This embodiment illustrates a gate assembly capable of efficiently shielding microwaves of multiple frequencies, with reference to... Figure 1 and Figure 2 The door assembly includes a door body 1. The inner surface of the door body 1, facing the inner pot of the cooking appliance, has a recess 11 extending along the edge of the door body 1 and ultimately forming a closed enclosure. Multiple layers (two or more) of choke plates 2 are arranged within the space corresponding to this recess 11. These choke plates 2 are spaced apart from each other in the thickness direction of the door body 1. The outer edge of each choke plate 2 is not tightly attached to the sidewall of the recess 11, but rather there is a certain gap. Importantly, each choke plate 2 has spaced-apart grooves c1 on its edge, and the solid portion between two adjacent grooves c1 constitutes a choke tooth c2 that can effectively interfere with and suppress microwave energy. Through the arrangement of multiple choke plates 2, multiple (two or more) choke grooves 3 are formed between the bottom of the recess 11 and the nearest choke plate 2, and between any two adjacent choke plates 2, spaced apart in the thickness direction of the door body 1. Each choke slot 3 has a depth from its inner perimeter to its outer perimeter that matches the microwave of a specific wavelength. The physical principle is that the depth is about one-quarter of the wavelength, so that each choke slot 3 can act as a highly efficient resonant cavity, producing a strong shielding and attenuation effect for the microwave of its corresponding specific frequency.

[0025] Compared to existing technologies that alternately arrange two types of choke grooves 3 of different depths along the edge of the door 1, this embodiment stacks and integrates choke grooves 3 with different functions in three-dimensional space. This layout greatly optimizes and saves the planar space occupied by the edge of the door 1, making the structure more compact, which is particularly beneficial for the aesthetic design of modern home appliances that pursue ultra-narrow bezels. More importantly, the alternating distribution mode of the existing technology has an inherent defect, namely, there is a physical gap between the shielding units of different frequencies, and microwave energy may leak out from the junction area between the two different choke grooves 3, forming a shielding blind zone or weak zone. However, this embodiment, through the layered arrangement of choke grooves 3 in the thickness direction of the door 1, makes the shielding structure for different frequencies almost completely overlap and cover in projection, eliminating any possible straight leakage path, thereby achieving continuous and uniform microwave protection for the entire edge of the door 1 without dead angles, significantly improving the overall shielding effectiveness and reliability.

[0026] In this embodiment, based on a thorough consideration of the electromagnetic field distribution and attenuation laws, the depth of each choke groove 3 is designed to gradually decrease from the direction away from the bottom of the recess 11 to the direction closer to the bottom of the recess 11. This means that the outermost choke groove 3, closest to the outer edge of the door 1, is usually the deepest to match microwaves with longer wavelengths and lower frequencies; while the depth of the choke groove 3 decreases progressively closer to the bottom of the recess 11, i.e., closer to the inner side of the door 1, to effectively shield microwaves with shorter wavelengths and higher frequencies. This gradient depth design cleverly conforms to the characteristics of microwaves during propagation and attenuation, because after microwave energy enters from the gap between the door 1 and the cavity, its field strength distribution usually gradually attenuates from the outside to the inside. By allocating a deeper choke groove 3 to the outside of microwaves with lower frequencies and longer wavelengths, it is possible to suppress and dissipate them more efficiently at the point where their energy is strongest. For microwaves with higher frequencies, whose energy is relatively easier to absorb and attenuate, a shallower choke groove 3 is allocated to the inside. This ensures sufficient shielding effect while avoiding excessive waste of materials and redundancy in structure, achieving an optimal balance between shielding effectiveness and structural economy.

[0027] In this embodiment, to further improve the suppression efficiency of microwave energy and broaden the effective frequency band, the length of the slots, i.e., slot c1, on each choke plate 2 is designed to gradually decrease along the direction from away from the bottom of the recess 11 to near the bottom of the recess 11. This gradient setting of the slot length directly affects the equivalent electrical length and resonant characteristics of the choke c2. Longer slots mean that the corresponding choke c2 has a longer equivalent current path, which can produce more effective reflection and destructive interference for lower frequency microwaves; while shorter slots are more suitable for disturbing and suppressing higher frequency microwaves. By making the slot length decrease from the outside to the inside, it can be coordinated with the aforementioned trend of the variation of the depth of the choke slot 3 to jointly construct an electromagnetic shielding system with continuously varying parameters in three-dimensional space, so that microwaves of different frequencies can find the most matching suppression structure on their propagation path, thereby achieving a smoother and more uniform high shielding efficiency throughout the entire target frequency band.

[0028] In this embodiment, to more precisely control the electromagnetic response characteristics of the choke structure, the width of the choke teeth c2 on each choke plate 2 is designed to gradually decrease from the direction away from the bottom of the recess 11 to the direction near the bottom of the recess 11. The width of the choke teeth c2 is a key parameter determining its equivalent inductance and capacitance, thus affecting its overall impedance characteristics. Wider choke teeth c2 generally have lower equivalent impedance, while narrower choke teeth c2 exhibit higher equivalent impedance. By setting the width to decrease from the outside to the inside, a gradually changing impedance distribution is actually constructed in space. When microwaves attempt to pass through these choke teeth c2, they experience a transition region with gradually changing impedance. This is very beneficial for promoting the gradual dissipation and reflection of microwave energy, rather than violent direct reflection. This matching transition can effectively reduce secondary energy reflection and possible resonance peaks caused by impedance abrupt changes, thereby making the microwave shielding effect smoother and more stable, and maintaining good performance over a wider frequency range, improving the robustness against frequency drift.

[0029] In this embodiment, based on the core objective of achieving high-efficiency wideband shielding, at least a portion of the choke slots 3 are configured such that their width along the depth direction is not constant, but rather exhibits a stepped variation. This structural arrangement means that the interior of a single choke slot 3 is no longer a uniform cavity, but rather forms multiple slot segments of different sizes through width variations. These slot segments are connected in series, collectively forming a multi-level impedance gradient along the electromagnetic wave propagation path. This offers superior technical performance compared to the standard choke slot 3 structure with a single depth and width commonly used in the prior art. Specifically, a traditional single-size choke slot 3 can be considered as a resonator tuned to a single frequency, and its high-efficiency shielding is limited to a very narrow frequency band. Once the magnetron output frequency drifts slightly due to aging, temperature changes, or manufacturing tolerances, its shielding effectiveness drops sharply, which is its high frequency sensitivity defect. Furthermore, its shielding effect is often poor against higher harmonics of the operating frequency or stray radiation of other frequencies. The stepped variable choke slot 3 in this solution integrates slot segments of different widths within a continuous physical structure. The resulting multi-stage impedance gradient smoothly guides electromagnetic waves deep into the choke slot 3, where they are gradually dissipated or reflected, significantly reducing the uneven energy reflection caused by drastic impedance changes. This transforms the choke slot 3 from a simple λ / 4 resonator into a broadband stopband filter, greatly extending its effective operating frequency band. Consequently, the gate assembly maintains high and stable shielding effectiveness over a wider frequency range. Even if the magnetron's output frequency drifts within a certain range, or if simultaneous suppression of higher harmonics is required, this multi-stage impedance gradient provides stable and reliable shielding, greatly improving product performance reliability and lifespan.

[0030] In this embodiment, to concretize the advantages of the aforementioned wideband shielding and leverage its synergistic effect, the choke slot 3, with its stepped width, is divided into two functionally distinct sections along its depth from the inner perimeter to the outer perimeter: a relatively wide wideband matching section 3a, followed by a relatively narrow harmonic suppression section 3b. Due to its relatively large physical width, the wideband matching section 3a corresponds to a lower optimal resonant frequency, meaning it can effectively capture and shield microwave components slightly below the center frequency of the main magnetron, broadening the low-frequency shielding range. Conversely, the harmonic suppression section 3b, with its relatively narrow width, corresponds to a higher optimal resonant frequency, enabling it to very accurately and efficiently shield the center frequency of the main magnetron's operation, as well as the second, third, and other higher harmonic frequencies that may be generated during its operation. Integrating these two sections is not a simple superposition, but rather produces a superior synergistic effect. The wideband matching section 3a provides a good initial impedance match for microwave energy entering the choke slot 3, guiding the energy smoothly into the slot; the harmonic suppression section 3b is responsible for the final efficient attenuation of the core high-frequency energy. This collaborative working mode ensures that a single choke slot 3 can cover a wide range of frequencies from near the fundamental frequency to important harmonic frequencies, achieving better overall broadband shielding performance with fewer structural units, simplifying the design and improving reliability.

[0031] In this embodiment, the width variation of the choke groove 3 along its depth direction is not achieved by adding other parts, but is provided by the shape of the choke plate 2 itself. This means that these choke plates 2 are not simple flat plates, but have specific bending, twisting, or stepped shape variations. This design is equivalent to cleverly extending the physical length of the choke plate 2 constituting the boundary of the choke groove 3 within a limited planar space, that is, increasing the actual path length of the microwave current flowing on the choke plate 2. According to electromagnetic theory, the increase in the current path reduces the current density per unit area, thereby mitigating the skin effect loss and potential hotspot problems on the metal surface of the choke plate 2. More importantly, the longer current path allows the mutually canceling electromagnetic fields within the choke groove 3 to interact more fully, making the microwave energy cancellation process more thorough and efficient, further improving the shielding depth and effectiveness of the choke groove 3. More specifically, the inner circumference and bottom of the recess 11 are provided with a plurality of stepped structures 12, and the sinking depth of the plurality of stepped structures 12 gradually increases from the inner circumference to the outer circumference of the recess 11. Each stepped structure 12 is provided with a choke plate 2. The choke plate 2 includes an extension 2a extending from the corner of the stepped structure 12 away from the bottom of the recess 11, and an extension 2b that bends from the extension 2a and extends to the outer circumference of the recess 11. Thus, the corresponding choke groove 3 forms a broadband matching section 3a from the inner circumference to the corner of the stepped structure 12, and a harmonic suppression section 3b from the corner of the stepped structure 12 to the outer circumference.

[0032] In this embodiment, to concretely realize the concept of multi-layer shielding, two key choke plates 2 are clearly arranged in the space corresponding to the recess 11: one is a first choke plate 21 relatively far from the bottom of the recess 11, and the other is a second choke plate 22 relatively close to the bottom of the recess 11. Through this arrangement, a first choke groove 3, called the first choke groove 31, is naturally formed between the first choke plate 21 and the second choke plate 22; simultaneously, a second choke groove 3, called the second choke groove 32, is formed between the second choke plate 22 and the bottom of the recess 11. This clear double-layer, double-groove structure layout allows each layer of choke groove 3 to be independently optimized for a specific frequency band of microwaves. The two choke grooves 3 are arranged side-by-side in space, without interfering with each other, yet together forming a complete protection system capable of simultaneously and efficiently shielding two completely different frequencies, solving the technical challenge of multi-band compatible shielding and providing possibilities for the multi-functionality of the equipment.

[0033] In this embodiment, the specific functional allocation of the aforementioned double-layer choke slots 3 is further clarified. The first choke slot 31 is specifically optimized for shielding microwaves in the 902 MHz to 928 MHz frequency band, while the second choke slot 32 is specifically optimized for shielding microwaves in the 2400 MHz to 2500 MHz frequency band. This explicit frequency assignment allows designers to calculate and determine the optimal depth and size of each choke slot 3 very precisely based on a quarter wavelength of the target frequency, thereby ensuring that each choke slot 3 achieves its theoretically maximum shielding effectiveness within its designated frequency band. This design is particularly suitable for advanced cooking equipment that needs to support two different microwave frequency bands simultaneously! For example, a hybrid oven that combines ordinary microwave heating and efficient steam functions@, ensuring that the door assembly provides equally excellent microwave leakage protection in any operating mode, meeting the most stringent safety standards.

[0034] Implementation Method 2:

[0035] This embodiment also illustrates a cooking device that includes the door assembly shown in Embodiment 1. Due to the integration of the door assembly of Embodiment 1, the cooking device of this embodiment possesses all the advantages of the aforementioned technical solutions, such as a compact frame design, excellent broadband microwave shielding effectiveness, efficient multi-band simultaneous shielding capability, stable anti-frequency drift characteristics, and more thorough energy dissipation. This makes the cooking device not only outstanding in safety, reliability, and service life, but also lays a solid technical foundation for its aesthetically pleasing industrial design and powerful multi-functional composite cooking capabilities.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A door assembly, characterized in that, The device includes a door body (1), the inner surface of which facing the inner liner has a recess (11) extending along its edge and forming an enclosure. The space corresponding to the recess (11) is provided with multiple layers of choke plates (2) spaced apart from each other in the thickness direction of the door body (1). There is a gap between the choke plate (2) and the periphery of the recess (11). The choke plate (2) has spaced grooves (c1) along its edge, and the choke plate (2) forms choke teeth (c2) in the portion between adjacent grooves (c1). The space corresponding to the recess (11) has a plurality of choke grooves (3) spaced apart from each other in the thickness direction of the door body (1) between two adjacent choke plates (2), between the bottom of the recess (11) and the choke plate (2) closest to it. The depth of each choke groove (3) from the inner periphery to the outer periphery is matched with the corresponding microwave wavelength, so that each choke groove (3) is suitable for shielding the corresponding microwave.

2. The door assembly according to claim 1, characterized in that, The depth of each of the choke grooves (3) gradually decreases along the direction from away from to near the bottom of the recess (11).

3. The door assembly according to claim 2, characterized in that, The length of the slot teeth of each of the chokes (2) gradually decreases along the direction from away from to near the bottom of the recess (11).

4. The door assembly according to claim 2, characterized in that, The width of the choke teeth (c2) of each of the choke plates (2) gradually decreases along the direction from away from to near the bottom of the recess (11).

5. The door assembly according to claim 1, characterized in that, At least a portion of the choke groove (3) is configured such that the choke groove (3) varies in a stepped manner along its depth direction to form a multi-level impedance gradient within the choke groove (3).

6. The door assembly according to claim 5, characterized in that, The choke groove (3), whose width varies in a stepped manner, is formed from the inner perimeter to the outer perimeter as a relatively wide broadband matching section (3a) and a relatively narrow harmonic suppression section (3b).

7. The door assembly according to claim 6, characterized in that, The width variation of the choke groove (3) along its depth direction is provided by the shape of the choke plate (2) to which it belongs.

8. The door assembly according to any one of claims 1-7, characterized in that, The space corresponding to the recess (11) is provided with a first choke plate (21) relatively far away from the bottom of the recess (11) and a second choke plate (22) relatively close to the bottom of the recess (11). Furthermore, the space corresponding to the recess (11) forms a first choke groove (31) between the first choke plate (21) and the second choke plate (22) and a second choke groove (32) between the second choke plate (22) and the bottom of the recess (11).

9. The door assembly according to claim 8, characterized in that, The first choke slot (31) is used to shield microwaves of 902MHz-928MHz, and the second choke slot (32) is used to shield microwaves of 2400-2500MHz.

10. A cooking device, characterized in that, Includes the door assembly as described in any one of claims 1-9.

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