Waveguide device and microwave cooking utensil

Abstract

The utility model discloses a waveguide device and a microwave cooking utensil, and relates to the technical field of microwave cooking, the waveguide device is provided with a wave guide channel and is provided with an incoming wave section and an outgoing wave section which are connected, the incoming wave section is provided with a microwave wave inlet communicated with the wave guide channel, and the outgoing wave section is provided with at least one microwave wave outlet; the waveguide wavelength of microwave transmitted by the waveguide device is lambda, and the perimeter L of the microwave outlet meets the condition that 0.5 lambda < = L < = 1.5 lambda; according to the technical scheme, the distribution uniformity of microwaves in the microwave heating cavity can be improved, and the cooking effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of microwave cooking, and particularly relates to a waveguide device and a microwave cooking appliance. Background Art

[0002] In microwave cooking appliances such as microwave rice cookers and microwave ovens, a waveguide device is usually provided to introduce microwaves generated by a microwave generating device such as a magnetron into a microwave heating cavity; in the related art, a microwave outlet is provided on the contact surface of the waveguide device that is oppositely arranged with respect to the appliance body forming the microwave heating cavity. However, when the size of the contact surface of the waveguide device is smaller than the cross-sectional size of the microwave heating cavity, it will cause the microwaves emitted from the microwave outlet to be difficult to cover the edge position of the microwave heating cavity, resulting in poor microwave heating uniformity and affecting the cooking effect. Summary of the Utility Model

[0003] The main purpose of the utility model is to propose a waveguide device and a microwave cooking appliance, aiming to improve the microwave cooking effect.

[0004] To achieve the above purpose, the waveguide device proposed by the utility model has a connected incoming wave band and outgoing wave band. The incoming wave band and the outgoing wave band are internally connected to form a waveguide channel. The incoming wave band is provided with a microwave inlet communicating with the waveguide channel, and the outgoing wave band is provided with at least one microwave outlet.

[0005] The waveguide wavelength of the waveguide device for transmitting microwaves is λ, and the perimeter L of the microwave outlet satisfies 0.5λ ≤ L ≤ 1.5λ.

[0006] In an embodiment, in the height direction perpendicular to the extending direction of the waveguide channel, the outgoing wave band has a top surface and a bottom surface arranged oppositely, and at least two of the microwave outlets are provided on the top surface.

[0007] In an embodiment, at least two of the microwave outlets are arranged along the width direction of the top surface and are axially symmetrically distributed, and the axis of symmetry extends along the extending direction of the waveguide channel;

[0008] And / or, at least four of the microwave outlets are provided on the top surface, and four of the microwave outlets are arranged in sequence along the circumferential direction of the top surface;

[0009] And / or, the distance L1 between any two points on the edges of at least two adjacent microwave outlets is L1 ≥ 0.1λ.

[0010] In an embodiment, at least one of the microwave outlets extends obliquely with respect to the extending direction of the waveguide channel.

[0011] In one embodiment, the included angle α between the extending direction of at least one of the microwave output ports and the extending direction of the waveguide channel satisfies 10° ≤ α ≤ 30°.

[0012] In one embodiment, the microwave output port is polygonal, and the number of sides of the microwave output port is not less than four.

[0013] In one embodiment, the distance d between any two points on two non-adjacent sides of at least one of the microwave output ports satisfies d ≥ 0.1λ;

[0014] And / or, a fillet is provided between two adjacent straight sides of the microwave output port.

[0015] In one embodiment, in the width direction perpendicular to the extending direction of the waveguide channel, the width D of at least a part of the waveguide channel located at the output end is D ≥ 100 mm;

[0016] And / or, in the height direction perpendicular to the extending direction of the waveguide channel, the height h of at least a part of the waveguide channel located at the output band satisfies 10 mm ≤ h ≤ 15 mm.

[0017] In one embodiment, the input band and the output band are arranged at an included angle and enclose a corner area. The microwave input port is provided on the surface of the input band facing the corner area, and the microwave output port is provided on the surface of the output band facing away from the corner area;

[0018] Or, the waveguide device is in the shape of a cuboid, and the input band and the output band are arranged along the length direction of the waveguide device.

[0019] The present application also provides a microwave cooking appliance, including an appliance main body, a microwave generating device, and the waveguide device as described in any one of the foregoing embodiments. The appliance main body forms a microwave heating cavity. The microwave generating device is communicated with the microwave input port of the waveguide device, and the microwave output port of the waveguide device is communicated with the microwave heating cavity;

[0020] The appliance main body includes a cavity structure and a cover body. The cavity structure forms a microwave heating cavity with an open top. The cover body is movably provided at the opening. A steam valve is provided on the cover body, and the steam valve can communicate the internal and external spaces of the microwave heating cavity when exhausting.

[0021] The technical solution of the present utility model limits the size of the microwave outlet on the waveguide device, so that the perimeter L of the microwave outlet satisfies 0.5λ ≤ L ≤ 1.5λ with the microwave wavelength λ transmitted by the waveguide device. With such a setting, the opening of the microwave outlet can be made relatively large, the coupling amount is increased, the coupling efficiency and the microwave energy transfer efficiency are improved, more microwave energy can be introduced into the microwave heating cavity, and the microwave energy distribution in the microwave heating cavity is made more uniform, thereby improving the uniformity of microwave heating and the cooking effect. Brief Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0023] Figure 1 Structural diagram of an embodiment of a microwave cooking appliance provided by the present application;

[0024] Figure 2 For Figure 1 Top view of the microwave cooking appliance with the cover removed in

[0025] Figure 3 Structural diagram of an embodiment of a waveguide device provided by the present application;

[0026] Figure 4 For Figure 3 Structural diagram of the waveguide device from another perspective in

[0027] Figure 5 For Figure 3 Side view of the waveguide device in

[0028] Explanation of the reference numerals in the drawings:

[0029] 100, microwave cooking appliance; 1, waveguide device; 11, incoming wave band; 12, outgoing wave band; 13, microwave incoming wave port; 14, microwave outgoing wave port; 15, waveguide channel; 2, appliance main body; 21, cavity structure; 22, cover; 23, microwave heating cavity; 3, microwave generating device.

[0030] The realization of the purpose, functional features and advantages of the present utility model will be further described in conjunction with the embodiments with reference to the drawings. Detailed Embodiments

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model.

[0032] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0033] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or the solution where A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0034] In microwave cooking appliances such as microwave rice cookers and microwave ovens, a waveguide device is usually provided to introduce the microwave generated by a microwave generating device such as a magnetron into the microwave heating cavity. In the related art, the waveguide device opens a microwave output port on the contact surface opposite to the appliance body forming the microwave heating cavity. However, when the size of the contact surface of the waveguide device is smaller than the cross-sectional size of the microwave heating cavity, it will cause the microwave output from the microwave output port to be difficult to cover the edge position of the microwave heating cavity, resulting in poor microwave heating uniformity and affecting the cooking effect.

[0035] To solve the above problems, the present utility model proposes a waveguide device 1.

[0036] Please refer to Figures 1 to 3, in an embodiment of the present utility model, the waveguide device 1 has a connected input band 11 and output band 12. The input band 11 and the output band 12 are internally connected to form a waveguide channel 15. The input band 11 is provided with a microwave input port 13 communicating with the waveguide channel 15, and the output band 12 is provided with at least one microwave output port 14; the waveguide wavelength of the microwave transmitted by the waveguide device 1 is λ, and the perimeter L of the microwave output port 14 satisfies 0.5λ ≤ L ≤ 1.5λ.

[0037] The waveguide device 1 proposed in this application is applied in a microwave cooking appliance 100. The microwave cooking appliance 100 can be a microwave oven, a microwave rice cooker, etc.; the microwave cooking appliance 100 further includes an appliance main body 2 forming a microwave heating cavity 23 and a microwave generating device 3 for generating microwaves. Among them, the microwave generating device 3 can be a magnetron, and the appliance main body 2 includes a cavity structure 21. The cavity structure 21 can form a microwave heating cavity 23 with an open top. At this time, the appliance main body 2 is correspondingly provided with a cover 22 for closing the microwave heating cavity 23; the cavity structure 21 can also be a microwave heating cavity 23 with a side opening. At this time, the appliance main body 2 is correspondingly provided with an openable and closable door that cooperates with the appliance main body 2; the cavity structure 21 is provided with a microwave feed inlet communicating with the microwave heating cavity 23. The cavity structure 21 is usually made of a metal material, a metal matrix composite material or other materials with microwave shielding functions, so as to avoid microwave leakage during the process of microwave cooking in the closed microwave heating cavity 23. In some embodiments, the microwave cooking appliance 100 further includes an inner container disposed in the microwave heating cavity 23. The inner container is used to hold food materials, and microwaves can penetrate the inner container and react with the food materials to heat the food materials.

[0038] The waveguide device 1 is formed with a waveguide channel 15 for guiding the microwave traveling wave. Along the extending direction of the waveguide channel 15, it is defined that the waveguide device 1 includes a connected input band 11 and output band 12. Among them, the waveguide channel 15 can extend linearly. At this time, the input band 11 and the output band 12 are substantially on the same straight line; the waveguide channel 15 can also extend in a bent manner. For example, the input band 11 and the output band 12 are perpendicular to each other. The input band 11 is provided with a microwave input port 13 communicating with the waveguide channel 15, and the output band 12 is provided with at least one microwave output port 14 communicating with the waveguide channel 15; when the waveguide device 1 is applied to the microwave cooking appliance 100, the microwave generating device 3 is connected to the microwave input port 13. For example, the antenna end of the magnetron is inserted into the microwave input port 13; the microwave output port 14 is arranged facing the microwave feed inlet of the microwave heating cavity 23 and communicates with the microwave heating cavity 23, so that the microwaves generated by the microwave generating device 3 are fed into the microwave heating cavity 23 through the waveguide channel 15 to heat the food materials.

[0039] In the embodiments of the present application, the waveguide wavelength of the microwave generated by the microwave generating device 3 in the waveguide channel 15 is defined as λ, and the perimeter of the microwave outlet 14 is L, and the value range of L is between 0.5λ and 1.5λ. L can take values of 0.5λ, 0.6λ, 0.8λ, λ, 1.2λ, 1.3λ, 1.5λ, and any value between 0.5λ and 1.5λ; wherein, the shape of the microwave outlet 14 can be circular, elliptical, or polygonal shapes such as triangular, rectangular, square, pentagonal, etc., or other regular or irregular shapes. Limiting the perimeter of a single microwave outlet 14 between 0.5λ and 1.5λ can improve the coupling efficiency and the microwave energy transfer efficiency, enable more microwave energy to be introduced into the microwave heating cavity 23, and can make the microwave energy distribution in the microwave heating cavity 23 more uniform, thereby improving the uniformity of microwave heating and the cooking effect.

[0040] In this embodiment, the number of microwave outlets 14 opened on the waveguide device 1 can be set according to the shape and contour size of the microwave heating cavity 23 and the microwave wavelength generated by the microwave generating device 3.

[0041] Therefore, it can be understood that in the technical solution of the present application, by limiting the size of the microwave outlet 14 on the waveguide device 1, the perimeter L of the microwave outlet 14 and the microwave wavelength λ transmitted by the waveguide device 1 satisfy 0.5λ ≤ L ≤ 1.5λ; with such a setting, the opening of the microwave outlet 14 can be relatively large, and the coupling amount is increased, improving the coupling efficiency and the microwave energy transfer efficiency. More microwave energy can be introduced into the microwave heating cavity 23, and the microwave energy distribution in the microwave heating cavity 23 is more uniform, thereby improving the uniformity of microwave heating and the cooking effect.

[0042] Referring to Figure 1 、 Figure 2 and Figure 4 , in an embodiment, in the height direction perpendicular to the extending direction of the waveguide channel 15, the output band 12 has a top surface and a bottom surface arranged opposite to each other, and at least two microwave outlets 14 are opened on the top surface.

[0043] In this embodiment, at least two microwave outlets 14 are opened on the waveguide device 1, so that the microwave energy in the waveguide channel 15 is dispersed under the interference of at least two microwave outlets 14, making the range where the microwave is transmitted from the waveguide device 1 wider, and then forming a relatively uniform thermal field in the microwave heating cavity 23, making the hot spot distribution in the microwave heating cavity 23 more uniform, and thus achieving the purpose of uniform heating.

[0044] When the waveguide device 1 is applied to a microwave cooking device 100, a single microwave feed port with a larger opening can be provided on the device body 2 to communicate with at least two microwave outlets 14 on the waveguide device 1; or at least two microwave feed ports can be provided on the device body 2 to communicate with each microwave outlet 14 of the waveguide device 1, which is not limited here.

[0045] See also Figure 4 In one embodiment, at least two microwave outlets 14 are arranged along the width direction of the top surface and are axially symmetrically distributed, and the symmetry axis extends along the extension direction of the waveguide channel 15.

[0046] It can be understood that the extension direction of the waveguide channel 15 is the traveling direction of the microwave in the waveguide channel 15, so that the wave output section 12 in the waveguide device 1 is provided with at least two microwave outlets 14 in the width direction perpendicular to the traveling direction, and the two microwave outlets 14 arranged along the width direction of the top surface are axially symmetrical with each other. With such a configuration, the microwave energy dispersed to the two microwave outlets 14 and outputted outward is roughly the same, which is beneficial to the uniform distribution of microwave energy in the microwave heating cavity 23 and improves the uniformity of microwave heating.

[0047] See also Figure 4 In one embodiment, at least four microwave outlets 14 are opened on the top surface, wherein the four microwave outlets 14 are arranged in sequence along the circumference of the top surface.

[0048] In this embodiment, at least four microwave outlets 14 are provided on the top surface of the wave exit section 12 which is arranged opposite to the microwave heating cavity 23, and the four microwave outlets 14 are arranged in sequence along the circumference of the top surface; the arrangement profile of the four microwave outlets 14 can be roughly similar to the cross-sectional profile of the microwave heating cavity 23, so that the microwave energy in the waveguide channel 15 can be interfered and dispersed by the at least four microwave outlets 14, and is evenly transmitted from the four microwave outlets 14 to different positions of the microwave heating cavity 23, which not only makes the range of microwave transmission from the waveguide device 1 wider, but also can form a relatively uniform thermal field in the microwave heating cavity 23, so that the hot spots in the microwave heating cavity 23 are more evenly distributed, thereby achieving the purpose of uniform heating.

[0049] In some embodiments, the four microwave outlets 14 can be distributed in two rows along the width direction of the waveguide channel 15, and the two rows of microwave outlets 14 are arranged axially symmetrically with each other, so as to further improve the uniformity of microwave distribution and improve the cooking effect.

[0050] See also Figure 4 In one embodiment, the distance L1 between any two points on the edges of at least two adjacent microwave outlets 14 is ≥0.1λ.

[0051] In the present embodiment, the distance between two adjacent microwave outlets 14 of the waveguide device 1 is limited, and the distance between any two points on the edge of the two adjacent microwave outlets 14 is defined as L, and L1 ≥ 0.1λ is required. Such a setting can avoid the two adjacent microwave outlets 14 being too close, and can prevent the microwaves from gathering at one place when the microwave cooking device 100 is unloaded, resulting in excessive electric field strength at that place, which easily forms a breakdown voltage to generate an arc and a loud current sound, thereby reducing the risk of ignition problems.

[0052] See also Figure 4 In one embodiment, at least one microwave outlet 14 extends obliquely relative to the extension direction of the waveguide channel 15 .

[0053] In the present embodiment, at least one microwave outlet 14 is extended obliquely relative to the extension direction of the waveguide channel 15, thereby increasing the wave output range of the microwave outlet 14 in the width direction of the waveguide channel 15, making the microwave transmission range wider, so as to enter the microwave heating cavity 23 more evenly, improve the microwave distribution and heating uniformity, and ensure the cooking effect.

[0054] See also Figure 4 In one embodiment, an angle α between an extension direction of at least one microwave outlet 14 and an extension direction of the waveguide channel 15 satisfies 10°≤α≤30°.

[0055] Among them, α can take the value of 10°, 12°, 15°, 18°, 20°, 22°, 25°, 28°, 30° or any value between 10° and 30°, so that the microwave outlet 14 can cover a wider range along the extension direction and width direction of the waveguide channel 15, so that the microwaves can be more evenly distributed in the microwave heating cavity 23, thereby improving the heating uniformity.

[0056] See also Figure 4 In one embodiment, the microwave outlet 14 is a polygon, and the number of sides of the microwave outlet 14 is not less than four.

[0057] In this embodiment, it is defined that the shape of the microwave outlet 14 is generally polygonal, and the number of sides of the microwave outlet 14 is not less than four. Herein, the number of sides of the microwave outlet 14 refers to the number of straight edges in the microwave outlet 14. That is, the shape of the microwave outlet 14 can be a quadrilateral, a pentagon, or other polygonal structures. Adjacent two straight edges can be directly connected, or a fillet can be provided between the two straight edges for transition, which is not limited herein. This setting method avoids the microwave outlet 14 being circular, thereby reducing microwave diffraction and lowering microwave energy loss. Additionally, when the microwave outlet 14 is set as a triangle, there are many acute-angle positions, and microwave aggregation is likely to occur at the acute-angle positions, resulting in too high an electric field strength at the acute-angle positions, and it is relatively easy to form a breakdown voltage to generate arcs and loud current sounds. By setting the shape of the microwave outlet 14 as a polygon, microwave energy loss can be reduced and the problem of excessive local electric field strength caused by microwave aggregation can be alleviated, enabling the microwave to be fed into the microwave heating cavity 23 more evenly and ensuring the cooking effect.

[0058] In some embodiments, the number of sides of the microwave outlet 1412 can be no more than 16. This setting method avoids the microwave outlet 1412 approaching a circular shape, thereby facilitating the reduction of microwave diffraction, lowering microwave energy loss, improving microwave transmission efficiency, and ensuring the cooking effect.

[0059] Please refer to Figure 4 , in one embodiment, the distance d between any two points on two non-adjacent sides of at least one microwave outlet 14 is d≥0.1λ.

[0060] Herein, the two non-adjacent sides refer to that the endpoints of the two straight edges are not directly connected, but are respectively connected to other straight edges, such that the distance d between any two points on the two sides is d≥0.1λ. By setting it like this, the problem of microwave aggregation at the microwave outlet 14 due to the too-close distance between the two non-adjacent edges of the microwave outlet 14 can be avoided, resulting in better microwave uniformity and less likelihood of microwave aggregation, reducing the risk of arcing problems and improving the use safety.

[0061] Please refer to Figure 4 , in one embodiment, a fillet is provided between two adjacent straight edges of the microwave outlet 1412.

[0062] By setting it like this, the sharp shape of the contour line of the microwave outlet 14 can be avoided, and further, the electric field strength at the intersection position of the two straight edges is too high, resulting in arcing at that position can be avoided. In some embodiments, a microwave feed inlet is provided on the bottom wall of the microwave heating cavity 23, and the cross-sectional contour of the microwave heating cavity 23 is generally rectangular. Four microwave outlets 14 are provided in the output band 12, and the four microwave outlets 14 are respectively located at the four corners of the rectangle. Fillets can be provided at the corners of the rectangle corresponding to each microwave outlet 14.

[0063] Please refer toFigure 4 , in one embodiment, in the width direction perpendicular to the extending direction of the waveguide channel 15, the width D of at least a part of the waveguide channel 15 located at the wave output end is ≥ 100 mm; wherein, D can take values of 100 mm, 110 mm, 120 mm, 125 mm, 130 mm, 150 mm or other values not less than 100 mm. With such a setting, the width of the waveguide channel 15 and the top surface size of the wave output band 12 are relatively large, which can not only increase the waveguide wavelength of the microwave in the waveguide channel 15 to ensure the transmission efficiency of the microwave, but also set larger and more microwave output ports 14 on the wave output band 12 to improve the microwave coupling and energy transmission efficiency, enable more microwave energy to be transmitted into the microwave heating cavity 23, and make the microwave energy distribution in the microwave heating cavity 23 more uniform, thereby improving the uniformity of microwave heating and the cooking effect.

[0064] Please refer to Figure 5 , in one embodiment, in the height direction perpendicular to the extending direction of the waveguide channel 15, the height h of at least a part of the waveguide channel 15 located at the wave output band 12 satisfies 10 mm ≤ h ≤ 15 mm.

[0065] Among them, h can take values of 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm or any value between 10 mm and 15 mm. With such a setting, it is beneficial to reduce the size of the waveguide device 1, thereby reducing the size of the microwave cooking appliance 100, which is beneficial to the miniaturization development of the waveguide device 1 and the microwave cooking device.

[0066] Combined with reference to Figure 1 , Figure 3 and Figure 4 , in one embodiment, the wave input band 11 and the wave output band 12 are arranged at an angle and enclose an installation space. A microwave input port 13 is opened on the surface of the wave input band 11 facing the installation space, and a microwave output port 14 is opened on the surface of the wave output band 12 facing away from the installation space.

[0067] In this embodiment, the wave input band 11 and the wave output band 12 of the waveguide device 1 are arranged at an angle, which can make the wave input band 11 and the wave output band 12 perpendicular to each other or at other angles. At this time, a corner area is formed between the wave input band 11 and the wave output band 12, and this corner area can be used to install the microwave generating device 3. Correspondingly, a microwave input port 13 needs to be opened on the surface of the wave input band 11 facing the corner area; and since the corner area is occupied by the microwave generating device 3, in order to avoid interference, the microwave output port 14 can be opened on the side of the wave output band 12 facing away from the corner area. This setting method can make the combined structure arrangement of the microwave generating device 3 and the waveguide device 1 more compact, which is beneficial to the miniaturization development of the microwave cooking appliance 100.

[0068] In one embodiment, the waveguide device 1 is in the shape of a cuboid, and the incoming waveband 11 and the outgoing waveband 12 are arranged along the length direction of the waveguide device 1.

[0069] In this embodiment, the waveguide device 1 is generally in the structure of a cuboid, and the incoming waveband 11 and the outgoing waveband 12 are arranged along the length direction of the cuboid. Among them, the microwave incoming wave port 13 and the microwave outgoing wave port 14 can be opened on the same surface of the cuboid or on different surfaces of the cuboid, which is not limited herein.

[0070] Please refer to Figure 1 and Figure 2 , this application also proposes a microwave cooking appliance 100, which includes an appliance main body 2, a microwave generating device, and the waveguide device 1 in any of the foregoing embodiments. The appliance main body 2 is formed with a microwave heating cavity 23. The microwave generating device is communicated with the microwave incoming wave port 13 of the waveguide device 1, and the microwave outgoing wave port 14 of the waveguide device 1 is communicated with the microwave heating cavity 23. The specific structure of the waveguide device 1 refers to the above embodiments.

[0071] Among them, the microwave cooking appliance 100 can be a microwave rice cooker, a microwave oven, etc. The microwave generating device 3 can be a magnetron, and the appliance main body 2 includes a cavity structure 21. The cavity structure 21 can form a microwave heating cavity 23 with an opening at the top. At this time, the appliance main body 2 is correspondingly provided with a cover body 22 for closing the microwave heating cavity 23; the cavity structure 21 can also be a microwave heating cavity 23 with an opening on the side. At this time, the appliance main body 2 is correspondingly provided with an openable and closable door body that cooperates with the appliance main body 2; the cavity structure 21 is provided with a microwave feed inlet communicating with the microwave heating cavity 23. The cavity structure 21 is usually made of a metal material, a metal matrix composite material, or other materials with microwave shielding functions, so as to avoid microwave leakage during the process of closing the microwave heating cavity 23 for microwave cooking. In some embodiments, the microwave cooking appliance 100 further includes an inner container disposed in the microwave heating cavity 23. The inner container is used to hold food materials, and the microwave can penetrate the inner container and react with the food materials to heat the food materials.

[0072] The waveguide device 1 is formed with a waveguide channel 15 for guiding a microwave traveling wave. Along the extending direction of the waveguide channel 15, it is defined that the waveguide device 1 includes an input band 11 and an output band 12 connected to each other. Among them, the waveguide channel 15 can extend linearly. At this time, the input band 11 and the output band 12 are substantially on the same straight line; the waveguide channel 15 can also extend in a bent manner. For example, the input band 11 and the output band 12 are perpendicular to each other. The input band 11 is provided with a microwave input port 13 communicating with the waveguide channel 15, and the output band 12 is provided with at least one microwave output port 14 communicating with the waveguide channel 15; when the waveguide device 1 is applied to the microwave cooking appliance 100, the microwave generating device 3 is connected to the microwave input port 13. For example, the antenna end of the magnetron is inserted into the microwave input port 13; the microwave output port 14 is arranged facing the microwave feeding port of the microwave heating cavity 23 and communicates with the microwave heating cavity 23, so that the microwave generated by the microwave generating device 3 is fed into the microwave heating cavity 23 through the waveguide channel 15 to heat the food materials.

[0073] Define the waveguide wavelength of the microwave generated by the microwave generating device 3 in the waveguide channel 15 as λ, and the perimeter of the microwave output port 14 as L, and make the value range of L between 0.5λ and 1.5λ. L can take values of 0.5λ, 0.6λ, 0.8λ, λ, 1.2λ, 1.3λ, 1.5λ and any value between 0.5λ and 1.5λ; among them, the shape of the microwave output port 14 can be circular, elliptical or polygonal shapes such as triangular, rectangular, square, pentagonal, etc., and can also be other regular or irregular shapes. And limiting the perimeter of a single microwave output port 14 between 0.5λ and 1.5λ can improve the coupling efficiency and the microwave energy transfer efficiency, enable more microwave energy to be introduced into the microwave heating cavity 23, and can make the microwave energy distribution in the microwave heating cavity 23 more uniform, thereby improving the uniformity of microwave heating and the cooking effect.

[0074] Since the microwave cooking appliance 100 proposed in this application adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0075] Please refer to Figure 1, in some embodiments, when the microwave cooking appliance 100 is a microwave rice cooker, the appliance body 2 of the microwave cooking appliance 100 includes a cavity structure 21 and a lid 22. The cavity structure 21 forms a microwave heating cavity 23 with an open top, and the lid 22 is pivotally attached to the cavity structure 21. Additionally, an inner pot that can be placed in the microwave heating cavity 23 can be provided. The inner pot is used to hold food ingredients, and microwaves can penetrate the inner pot and react with the food ingredients to heat the food ingredients, thus completing the rice cooking process. A steam valve can be provided on the lid 22. The steam valve can connect the internal and external spaces of the microwave heating cavity 23 during exhaust to discharge some of the steam and other gases in the microwave rice cooker, adjust the pressure in the microwave heating cavity 23, and keep the air pressure in the microwave rice cooker stable to avoid excessive pressure.

[0076] When the lid 22 is attached to the cavity structure 21, the inside of the microwave heating cavity 23 can be in an atmospheric pressure state; or the pressure inside the microwave heating cavity 23 can be greater than the ambient pressure outside the microwave cooking appliance 100. In other words, the microwave rice cooker can also be a pressure cooker. When the lid 22 is attached to the cavity structure 21, a slightly pressurized or highly pressurized environment can be formed in the microwave heating cavity 23.

[0077] In some embodiments, a microwave feed inlet communicating with the microwave heating cavity 23 can be opened on the bottom wall of the cavity structure 21, and at least part of the waveguide device 1 can be disposed below the cavity structure 21. Among them, the incoming wave band 11 and the outgoing wave band 12 of the waveguide device 1 can be vertically arranged, and a corner area can be formed on the side of the outgoing wave band 12 away from the cavity structure 21. The microwave generating device can be disposed in the corner area, thereby reducing the size of the microwave cooking appliance 100 in the cross-sectional direction. Alternatively, in some embodiments, the waveguide device 1 is generally in a cuboid structure, the incoming wave band 11 and the outgoing wave band 12 are arranged along the length direction of the cuboid, and the microwave incoming wave port 13 of the incoming wave band 11 can be opened on the top surface of the incoming wave band 11 to dispose the microwave generating device above the incoming wave band 11, thereby reducing the size of the microwave cooking appliance 100 in the height direction.

[0078] The above are only exemplary embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A waveguide device, characterized in that, The waveguide device has a connected input band and output band. The inside of the input band and the output band is connected to form a waveguide channel. The input band is provided with a microwave input port communicating with the waveguide channel, and the output band is provided with at least one microwave output port. The waveguide wavelength of the microwave transmitted by the waveguide device is λ, and the perimeter L of the microwave output port satisfies 0.5λ ≤ L ≤ 1.5λ.

2. The waveguide device according to claim 1, characterized in that, In the height direction perpendicular to the extending direction of the waveguide channel, the output band has a top surface and a bottom surface arranged oppositely, and at least two of the microwave output ports are provided on the top surface.

3. The waveguide device according to claim 2, wherein, At least two of the microwave output ports are arranged along the width direction of the top surface and are axially symmetrically distributed, and its axis of symmetry extends along the extending direction of the waveguide channel. And / or, at least four of the microwave output ports are provided on the top surface, and four of the microwave output ports are arranged in sequence along the circumferential direction of the top surface. And / or, the distance L1 between any two points on the edges of at least two adjacent microwave output ports is L1 ≥ 0.1λ.

4. The waveguide device according to claim 1, characterized in that, At least one of the microwave output ports extends obliquely with respect to the extending direction of the waveguide channel.

5. The waveguide device according to claim 4, characterized in that, The included angle α between the extending direction of at least one of the microwave output ports and the extending direction of the waveguide channel satisfies 10° ≤ α ≤ 30°.

6. The waveguide device according to claim 1, wherein, The microwave output port is polygonal, and the number of sides of the microwave output port is not less than four.

7. The waveguide device according to claim 6, wherein, The distance d between any two points on two non-adjacent sides of at least one of the microwave output ports is d ≥ 0.1λ; And / or, a fillet is provided between two adjacent straight sides of the microwave output port.

8. The waveguide device according to claim 1, wherein, In the width direction perpendicular to the extending direction of the waveguide channel, the width D of at least a part of the waveguide channel located at the output end is D ≥ 100 mm; And / or, in the height direction perpendicular to the extending direction of the waveguide channel, the height h of at least a part of the waveguide channel located at the output band satisfies 10 mm ≤ h ≤ 15 mm.

9. The waveguide device according to any one of claims 1 to 8, characterized in that, The input band and the output band are arranged at an angle and enclose a corner area. The microwave input port is provided on the surface of the input band facing the corner area, and the microwave output port is provided on the surface of the output band facing away from the corner area. Or, the waveguide device is in the shape of a cuboid, and the input band and the output band are arranged along the length direction of the waveguide device.

10. A microwave cooking appliance, characterized in that, It includes an appliance main body, a microwave generating device, and the waveguide device according to any one of claims 1 to 9. The appliance main body forms a microwave heating cavity. The microwave generating device is communicated with the microwave input port of the waveguide device, and the microwave output port of the waveguide device is communicated with the microwave heating cavity. The appliance main body includes a cavity structure and a cover body. The cavity structure forms a microwave heating cavity with an open top. The cover body is movably provided at the opening. A steam valve is provided on the cover body, and the steam valve can communicate the internal and external spaces of the microwave heating cavity when exhausting.

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