A microwave shielding structure

Abstract

The present invention discloses a microwave shielding structure, which includes a base and a fastener, wherein the base includes at least a through hole penetrating the upper and lower surfaces of the base; the fastener includes a cap body and a rod body fixed together, and the rod body penetrates and is fixed in the through hole; an anti-flow groove structure is formed between the cap body and the base; the cap body is provided with a first groove formed by being concave inwardly around the outer surface of its side wall; a gap is left between the base and the cap body; the base is provided with a second groove formed by being concave inwardly around the outer surface of the side wall of the base; the first groove, the second groove and the gap together form the anti-flow groove structure. The microwave shielding structure of the present invention can effectively avoid a large amount of microwave leakage at the opening of the microwave rotating shaft, reduce the interference of the leaked microwave on the electrical components and the damage to the parts, and reduce the harm of the leaked microwave to the human body; and the structure is simple, easy to install, and convenient for industrial application.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic shielding equipment, and more specifically, to a microwave shielding structure. Background Art

[0002] Microwaves are electromagnetic waves with frequencies ranging from 300MHz to 3000GHz, that is, wavelengths ranging from 1m to 0.1mm. Microwaves, as a form of energy, can be converted into heat in a medium. Therefore, using microwaves to heat materials has become a common heating method. The penetrability of microwaves makes it possible to heat both inside and outside at the same time and with a fast heating speed. However, due to the propagation characteristics of microwaves, it is easy to cause uneven microwave heating.

[0003] In this regard, the prior art often adopts the method of adding a turntable structure to realize the relative movement between the heating medium and the microwave field so as to improve the uniformity of microwave heating. The addition of the turntable structure is bound to add an opening on the microwave heating cavity to install the rotating shaft, and the rotating shaft rotates to drive the turntable to move. The structure of the rotating shaft passing through the circular hole is similar to the structure of the coaxial line. There will be a gap between the rotating shaft and the circular hole, which is easy to cause a large amount of microwave leakage. The leakage of high-power microwaves is harmful to the human body, so it is necessary to perform microwave shielding on the rotating shaft opening structure. At present, the microwave shielding structure commonly used in the rotating shaft opening structure of the microwave heating cavity is to use a microwave shielding cover to enclose the entire rotating system including the rotating motor to prevent secondary leakage of microwaves. However, this method has two defects. First, the microwaves leaking from the microwave heating cavity will cause certain interference and damage to electrical equipment such as the rotating motor. Second, this structure is relatively complex, and it is troublesome to install and maintain, and it is difficult to use for industrial applications.

[0004] Therefore, in order to overcome the defects of the prior art, it is necessary to provide a new type of microwave shielding structure. Summary of the invention

[0005] The purpose of the present invention is to provide a microwave shielding structure which can effectively prevent a large amount of microwave leakage at the opening of the microwave rotating shaft and effectively control the microwave leakage at the working position to 5mW / cm 2 In the following, the interference of leaked microwaves on electrical components and the damage to parts are reduced, and the harm of leaked microwaves to the human body is reduced; at the same time, the airtight seal at the opening of the rotating shaft is effectively achieved. In addition, the structure has the characteristics of simple structure and convenient installation, which is convenient for industrial application.

[0006] To achieve the above-mentioned purpose, the present invention provides a microwave shielding structure, which includes a base and a fastener, wherein the base includes at least a through hole penetrating the upper and lower surfaces of the base; the fastener includes a cap body and a rod body combined and fixed together, and the rod body passes through and is fixed in the through hole; an anti-flow groove structure is formed between the cap body and the base; the cap body is provided with a first groove formed by being concave inwardly around the outer surface of its side wall; a gap is left between the base and the cap body; the base is provided with a second groove formed by being concave inwardly around the outer surface of the side wall of the base; the first groove, the second groove and the gap together form the anti-flow groove structure.

[0007] In addition, a preferred solution is that one end of the cap body close to the base is indented inward to form a step portion, and the first groove is formed on a side wall of the step portion.

[0008] In addition, a preferred solution is that the base includes a boss protruding outward from a side surface thereof close to the cap body, and the second groove is formed on a side wall of the boss.

[0009] In addition, a preferred solution is that the first groove and the second groove have the same height in the axial direction of the through hole; and the first groove and the second groove have the same depth in the radial direction of the through hole.

[0010] In addition, a preferred solution is that the height of the first groove in the axial direction of the through hole is 2-4 mm, and the depth in the radial direction of the through hole is 25-35 mm; the height of the second groove in the axial direction of the through hole is 2-4 mm, and the depth in the radial direction of the through hole is 25-35 mm.

[0011] In addition, a preferred solution is that the gap between the base and the cap body is 2-4 mm.

[0012] In addition, a preferred solution is that the structure also includes a shaft fixing device located below the base; the shaft fixing device includes a sealing ring sleeved on the rod body; the sealing ring is provided with an oil seal ring and an O-ring; the O-ring is configured to seal the gap between the base and the sealing ring; the oil seal ring is configured to seal the gap between the rod body and the sealing ring.

[0013] In addition, a preferred solution is that the rod body includes an equal-diameter portion combined and fixed with the through hole and the sealing ring, and a retracted portion formed by retracting the diameter of one end of the equal-diameter portion inward; the shaft fixing device also includes an extension portion surrounding the retracted portion and a bearing portion located between the extension portion and the retracted portion, and the bearing portion is configured to be combined and fixed with the retracted portion.

[0014] In addition, a preferred solution is that the bearing portion includes a first bearing, a retaining ring and a second bearing, and the first bearing inner ring abuts against the side wall surface of the retracted portion and the bottom surface of the equal-diameter portion.

[0015] In addition, a preferred solution is that the rod body also includes an exposed portion extending outward from one end of the retracted portion of the rod body, and the exposed portion of the rod body is located outside the bearing portion and is provided with a thread; the shaft fixing device is provided with a locking nut corresponding to the thread of the exposed portion of the rod body, and the top end of the nut can abut against the inner ring of the second bearing.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. The microwave shielding structure provided by the present invention is equipped with an anti-flow groove structure, which can effectively prevent a large amount of microwave leakage at the opening of the microwave field rotation axis, and can effectively control the microwave leakage at the working position to 5mW / cm 2 In the following, the interference of leaked microwaves on electrical components and the damage to parts are reduced, and the harm of leaked microwaves to the human body is reduced; and the structure has the characteristics of simple structure, convenient installation and maintenance, and is convenient for industrial application.

[0018] 2. The microwave shielding structure provided by the present invention is equipped with a sealing ring, an oil sealing ring and an O-ring, which can further achieve gas isolation inside and outside the microwave heating cavity and ensure gas sealing at the opening of the rotating shaft.

[0019] 3. The bearing part and locking nut of the microwave shielding structure provided by the present invention can realize radial and axial fixation of the rotating shaft, effectively support the rod body and bear the axial force and radial force of the rotating shaft during rotation, ensure that the rotating shaft will not shake up and down or left and right during rotation, and at the same time ensure the rotation accuracy of the rotating shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0021] Figure 1 A schematic diagram of the exploded structure of a microwave shielding structure according to an embodiment of the present invention is shown.

[0022] Figure 2 A schematic diagram of the assembly structure of a microwave shielding structure provided by an embodiment of the present invention is shown.

[0023] Figure 3 A cross-sectional view of an assembly structure of a microwave shielding structure according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0024] In the following description, for the purpose of explanation, in order to provide a thorough understanding of one or more embodiments, numerous specific details are set forth. However, it is apparent that these embodiments may also be implemented without these specific details.

[0025] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0026] At present, in view of the characteristics and current situation of uneven microwave heating, a turntable structure is often used to achieve relative movement between the heating medium and the microwave field. To add a turntable structure, it is necessary to add an opening to the microwave heating cavity to install a rotating shaft, and the turntable is driven by the rotation of the rotating shaft. However, the structure of the rotating shaft passing through the circular hole is similar to the structure of a coaxial line. There will be a gap between the rotating shaft and the circular hole, which can easily lead to a large amount of microwave leakage. High-power microwave leakage is harmful to the human body, so it is necessary to perform microwave shielding on the rotating shaft opening structure. In the prior art, the more commonly used microwave shielding structure in the rotating shaft opening structure of the microwave heating cavity is to use a microwave shielding cover to enclose the entire rotating system including the rotating motor to prevent secondary leakage of microwaves. However, research has found that this shielding method has two defects. First, the microwaves leaking from the microwave heating cavity will cause certain interference and damage to electrical components such as the rotating motor. Second, this structure is relatively complex, and it is troublesome to install and maintain, making it difficult to use for industrial applications. In order to overcome the defects of the prior art, combined with Figure 1-3 As shown, the present invention provides a preferred embodiment, which provides a microwave shielding structure, such as Figure 1As shown, the microwave shielding structure includes a base 20 and a fastener 10, the fastener 10 is a rotating shaft, and the base 20 includes at least a through hole 21 passing through the upper and lower surfaces of the base 20; the fastener 10 includes a cap body 11 and a rod body 12 combined and fixed together, and the rod body 12 passes through and is fixed in the through hole 21; an anti-flow groove structure 30 is formed between the cap body 11 and the base 20; the cap body 11 is provided with a first groove 31 formed by being recessed inward around the outer surface of its side wall; further preferably, one end of the cap body 11 close to the base 20 is indented inward to form a step portion 111, the step portion 111 is located outside the through hole 21, and the first groove 31 is formed on the side wall of one end of the step portion 111 close to the base 20. A gap 33 is left between the top surface of the base 20 and the bottom surface of the cap body 11; the base 20 is provided with a second groove 32 which is formed inwardly concave around the outer surface of the side wall of the base 20; further preferably, the base 20 includes a boss 22 which protrudes outward from a side surface thereof close to the cap body 11, and the second groove 32 is formed on the side wall of one end of the boss 22 close to the cap body 11. The first groove 31, the second groove 32 and the gap 33 together form the anti-flow groove structure 30. With the microwave shielding structure of this embodiment, a new type of anti-flow groove structure can be formed through the synergistic effect between the first groove, the second groove and the gap, specifically as Figure 2 As shown, by utilizing the impedance transformation characteristics of a quarter-wavelength transmission line, an electric field open circuit will be formed at point A of the first groove, and an electric field short circuit will be formed at point B. Therefore, the cylindrical surface at point A can realize an electric field open circuit, so that the current is zero, and electromagnetic waves cannot be transmitted here, thereby achieving the effect of microwave shielding. It can be understood by those skilled in the art that the microwave shielding principle of the second groove and the gap is the same as that of the first groove. Through the synergistic effect between the first groove, the second groove and the gap, it is ensured that there will be no large amount of microwave leakage at the opening of the microwave rotating shaft. In addition, compared with the existing technology that uses a microwave shielding cover to enclose the entire rotating system including the rotating motor, the microwave shielding structure in this preferred embodiment has a better microwave shielding effect, which can effectively control the microwave leakage at the working position to 5mW / cm 2 The following can also reduce the interference and damage of leaked microwaves to electronic components and extend the service life of electronic components; and compared with the existing technology of using special-shaped grooves for microwave shielding, the structure of the microwave shielding structure is simpler, easier to process, convenient to install and maintain, and suitable for industrial applications.

[0027] In a more preferred embodiment, the first groove 31 and the second groove 32 have the same height in the axial direction of the through hole 21; the first groove 31 and the second groove 32 have the same depth in the radial direction of the through hole 21. Further preferably, the height of the first groove 31 in the axial direction of the through hole 21 is 2-4mm, and the depth in the radial direction of the through hole 21 is 25-35mm; the height of the second groove 32 in the axial direction of the through hole 21 is 2-4mm, and the depth in the radial direction of the through hole 21 is 25-35mm. In addition, the gap between the base 20 and the cap body 11 is preferably 2-4mm. This structure can make the gap cooperate with the first groove and the second groove to effectively realize microwave shielding, and at the same time avoid the occurrence of microwave ignition accidents.

[0028] In addition, in order to further achieve the gas isolation inside and outside the microwave heating cavity and ensure the gas sealing at the opening of the rotating shaft, the present invention also provides another preferred embodiment, such as Figure 1-2 As shown, the structure also includes a shaft fixing device located below the base 20; the shaft fixing device includes a sealing ring 41 sleeved on the rod body 12; the sealing ring 41 is provided with an oil seal ring 42 and an O-ring 43; the O-ring 43 is configured to seal the gap between the base 20 and the sealing ring 41; the oil seal ring 42 is sleeved on the rod body 12, and is used to seal the gap between the rod body 12 and the sealing ring 41, so as to achieve an isolation and airtight seal between the gap between the rod body 12 and the inner wall of the through hole 20 and the outside world.

[0029] Furthermore, if Figure 3As shown, the rod body 12 includes an equal diameter portion 121 fixedly combined with the through hole 21 and the sealing ring 41, and a retracted portion 122 formed by retracting the diameter of one end of the equal diameter portion 121 inwardly; the shaft fixing device also includes an extension portion 44 surrounding the retracted portion 122 and the sealing ring 41, and a bearing portion 45 located between the extension portion 44 and the retracted portion 122, and the bearing portion 45 is configured to be combined and fixed with the retracted portion 122. The extension portion 44 is connected and fixed to the base 20 by bolts. More preferably, the bearing portion 45 includes a first bearing 451, a retaining ring 452 and a second bearing 453, and the first bearing 451 abuts against the side wall surface of the retracted portion 122 and the bottom surface of the equal diameter portion 121, which can effectively support the rod body and bear the axial force and radial force during the rotation of the rod body, ensuring that the rotating shaft will not shake left and right during the rotation process, while ensuring the rotation accuracy of the rotating shaft. In addition, the rod body 12 also includes an exposed portion 123 extending outward from one end of the retracted portion 122 of the rod body, and the exposed portion 123 of the rod body is located outside the bearing portion 45 and is provided with a thread 124; the shaft fixing device is provided with a nut 46 corresponding to the thread 124 of the exposed portion of the rod body, and the top end of the nut 46 can abut against the second bearing 453 to ensure the axial fixation of the rod body and ensure that the rotating shaft does not shake up and down during rotation.

[0030] During operation, the bearing part 45 is first installed in the extension part 44 in the order of the second bearing 453, the retaining ring 452 and the first bearing 451, and then the oil seal ring 42 and the O-ring 43 are installed in the sealing ring 41, and then the sealing ring 41 is installed in the extension part 44, and then the extension part 44 is connected and fixed to the base 20 with bolts. Finally, the fastener 10 (i.e., the rotating shaft) passes through the through hole 21 of the base 20 and is sleeved on the shaft fixing device, and the side wall surface of the retracted part 122 of the rod body and the bottom surface of the equal diameter part 121 are in contact with the first bearing 451, and then the nut 46 is used to cooperate with the thread 124 of the exposed part 123 to abut and fix with the second bearing 453. The microwave shielding structure of this preferred embodiment forms a new type of anti-flow groove structure through the first groove, the second groove and the gap between the cap body and the base. By utilizing the impedance transformation characteristics of the quarter-wavelength transmission line, the electric field can be opened at the first groove, the second groove and the gap cylindrical surface, so that the current is zero and the electromagnetic wave cannot be transmitted, thereby realizing microwave shielding and avoiding a large amount of microwave leakage at the opening of the rotating shaft, and controlling the microwave leakage at the working position to 5mW / cm 2 The following effectively reduces the interference and damage of leaked microwaves to electronic components and reduces the harm of leaked microwaves to the human body; and by configuring the shaft fixing device, on the one hand, an airtight seal is achieved at the opening of the rotating shaft, and on the other hand, it can ensure that the rotating shaft will not shake up and down or left and right during rotation, while ensuring the rotation accuracy of the rotating shaft.

[0031] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A microwave shielding structure, comprising a base and a fastener, characterized in that: The base at least includes through holes penetrating the upper and lower surfaces of the base; The fastener comprises a cap body and a rod body which are combined and fixed together, and the rod body passes through and is fixed in the through hole; An anti-flow groove structure is formed between the cap body and the base; The cap body is provided with a first groove which is formed by surrounding the outer surface of the side wall and is inwardly recessed; A gap is left between the base and the cap body; The base is provided with a second groove which surrounds the outer surface of the side wall of the base and is inwardly recessed; The first groove, the second groove and the gap together form the anti-flow groove structure; The structure also includes an axis fixing device located below the base; The shaft fixing device comprises a sealing ring sleeved on the rod body; the sealing ring is provided with an oil seal ring and an O-ring; The O-ring is configured to seal the gap between the base and the sealing ring; The oil seal ring is configured to seal the gap between the rod body and the sealing ring; The rod body includes an equal-diameter portion fixedly combined with the through hole and the sealing ring, and an indented portion formed by indenting the diameter of one end of the equal-diameter portion inwardly; The shaft fixing device further includes an extension portion surrounding the retracted portion and a bearing portion located between the extension portion and the retracted portion, wherein the bearing portion is configured to be combined and fixed with the retracted portion; The bearing portion includes a first bearing, a retaining ring and a second bearing, wherein the inner ring of the first bearing abuts against the side wall surface of the retracted portion and the bottom surface of the equal-diameter portion; The rod body also includes an exposed portion extending outward from one end of the rod inwardly contracted portion, the exposed portion being located outside the bearing portion and being provided with threads; The shaft fixing device is provided with a locking nut corresponding to the thread of the exposed portion of the rod body, and the top end of the locking nut abuts against the inner ring of the second bearing.

2. The structure according to claim 1, characterized in that: One end of the cap body close to the base is indented inward to form a step portion, and the first groove is formed on the side wall of the step portion.

3. The structure according to claim 1, characterized in that: The base includes a boss protruding outward from a side surface thereof close to the cap body, and the second groove is formed on a side wall of the boss.

4. The structure according to claim 1, characterized in that The first groove and the second groove have the same height in the axial direction of the through hole; The first groove and the second groove have the same depth in the radial direction of the through hole.

5. The structure according to claim 1, characterized in that: The height of the first groove in the axial direction of the through hole is 2-4 mm, and the depth in the radial direction of the through hole is 25-35 mm; The second groove has a height of 2-4 mm in the axial direction of the through hole and a depth of 25-35 mm in the radial direction of the through hole.

6. The structure according to claim 1, characterized in that: The gap between the base and the cap body is 2-4 mm.

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