Antenna drive mechanism and microwave heating device

Abstract

To provide an antenna drive mechanism achieving both high functionality and downsizing, and also to provide a microwave heating device.SOLUTION: An antenna drive mechanism is provided with: an antenna shaft supporting a rotary antenna; a motor shaft rotatable integrally with the antenna shaft and rotatably driven in a first rotation direction or a second rotation direction; and a first rotation regulation part and a second rotation regulation part. The antenna shaft relatively moves to a second position where rotation regulation is cancelled from a first position where the rotation regulation is received according to rotation of the motor shaft in the first rotation direction while receiving the rotation regulation by the first rotation regulation part along the axial direction. The antenna shaft relatively moves to the first position where the rotation regulation is cancelled from the second position where the rotation regulation is received according to rotation of the motor shaft in the second rotation direction while receiving the rotation regulation by the second rotation regulation part along the axial direction.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present disclosure relates to an antenna driving mechanism for driving a rotating antenna and a microwave heating device including the same. [Background technology]

[0002] 2. Description of the Related Art Conventionally, microwave heating devices have been known in which an object to be heated, such as food, is placed in a heating chamber and microwaves are supplied into the heating chamber to heat and cook the object to be heated (see, for example, Patent Document 1).

[0003] The microwave heating device of Patent Document 1 includes a rotating antenna for supplying microwaves to a heating chamber, an antenna rotating motor for rotating the rotating antenna, and an antenna vertical movement motor for moving the rotating antenna up and down. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4024145 Summary of the Invention [Problem to be solved by the invention]

[0005] In the microwave heating device of Patent Document 1, a motor is required for each of the rotation function and the vertical movement function of the rotating antenna, which tends to make the device large. It can be said that there is room for improvement in terms of achieving both high functionality and miniaturization of the microwave heating device.

[0006] Therefore, an object of the present disclosure is to solve the above problems and to provide an antenna driving mechanism that can achieve both high functionality and compact size, and a microwave heating device equipped with the same. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the antenna driving mechanism of the present disclosure comprises an antenna shaft supporting a rotating antenna for supplying microwaves to a heating chamber, a motor shaft that is screwed onto the antenna shaft and can rotate integrally with the antenna shaft and is rotationally driven in a first rotation direction or a second rotation direction, a first rotation regulating unit that selectively regulates rotation of the antenna shaft in the first rotation direction, and a second rotation regulating unit that selectively regulates rotation in the second rotation direction, wherein, in a state where the antenna shaft is rotationally regulated by the first rotation regulating unit, in response to the motor shaft rotating in the first rotation direction, the antenna shaft moves relatively along the axial direction from a first position where the rotation restriction is imposed to a second position where the rotation restriction is released, and, in a state where the antenna shaft is rotationally regulated by the second rotation regulating unit, in response to the motor shaft rotating in the second rotation direction, the antenna shaft moves relatively along the axial direction from the second position where the rotation restriction is imposed to the first position where the rotation restriction is released.

[0008] In addition, the antenna driving mechanism of the present disclosure includes an antenna shaft supporting a rotating antenna for supplying microwaves to a heating chamber, a motor that applies a rotational driving force in a first rotation direction or a second rotation direction to the antenna shaft, a rotation regulating unit that selectively regulates the rotational movement of the antenna shaft so that, when the antenna shaft receives the rotational driving force in the first rotation direction, the axial position of the antenna shaft is positioned at a first position, and, when the antenna shaft receives the rotational driving force in the second rotation direction, the axial position of the antenna shaft is positioned at a second position different from the first position, and a control unit that controls the rotational direction of the rotational driving force by the motor.

[0009] The microwave heating device of the present disclosure also includes the antenna driving mechanism, the rotating antenna driven by the antenna driving mechanism, and the heating chamber to which the rotating antenna supplies microwaves. Effect of the Invention

[0010] According to the present disclosure, it is possible to achieve both high functionality and miniaturization. [Brief description of the drawings]

[0011] [Figure 1A] Schematic side view of a microwave heating device according to an embodiment. [Figure 1B] 1 is a schematic side view of a microwave heating device according to an embodiment; [Diagram 2] 1 is a schematic plan view of a rotating antenna according to an embodiment of the present invention; [Figure 3A] FIG. 2 is a perspective view of an antenna driving mechanism according to an embodiment; [Figure 3B] FIG. 2 is a perspective view of an antenna driving mechanism according to an embodiment; [Figure 4] FIG. 2 is an exploded perspective view of an antenna driving mechanism according to an embodiment; [Diagram 5] FIG. 2 is an exploded perspective view of an antenna driving mechanism according to an embodiment; [Figure 6] FIG. 1 is a perspective view showing an antenna shaft and a motor screw according to an embodiment; [Figure 7] FIG. 2 is an exploded perspective view of an antenna shaft according to an embodiment; [Figure 8] FIG. 2 is an exploded perspective view of an antenna shaft according to an embodiment; [Figure 9] FIG. 1 is a cross-sectional view showing a schematic cross section of an antenna shaft according to an embodiment; [Figure 10A] FIG. 1 is a cross-sectional view (raised position) showing a schematic longitudinal section of the antenna shaft and its surrounding structure according to an embodiment; [Figure 10B] FIG. 1 is a cross-sectional view (lowered position) showing a schematic longitudinal section of the peripheral configuration of an antenna shaft according to an embodiment; [Figure 11] FIG. 1 is a perspective view of a ring member according to an embodiment; [Figure 12] FIG. 1 is a perspective view of a ring member according to an embodiment; [Figure 13] FIG. 13 is a perspective view illustrating an operation when the movable pin of the embodiment is located at a lower stage and rotates in a first rotation direction; [Figure 14] FIG. 13 is a perspective view illustrating an operation when the movable pin of the embodiment is located at an upper stage and rotates in a first rotation direction; [Figure 15] FIG. 13 is a perspective view illustrating an operation when the movable pin in the embodiment is located at an upper stage and rotates in a second rotation direction; [Figure 16] FIG. 13 is a perspective view illustrating an operation when the movable pin in the embodiment is located at a lower stage and rotates in a second rotation direction; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] According to a first aspect of the present disclosure, there is provided an antenna driving mechanism comprising: an antenna shaft supporting a rotating antenna for supplying microwaves to a heating chamber; a motor shaft screwed onto the antenna shaft and rotatable integrally with the antenna shaft and driven to rotate in a first rotation direction or a second rotation direction; a first rotation regulating unit selectively restricting rotation of the antenna shaft in the first rotation direction, and a second rotation regulating unit selectively restricting rotation in the second rotation direction, wherein, in a state where the antenna shaft is rotationally restricted by the first rotation regulating unit, in response to the motor shaft rotating in the first rotation direction, the antenna shaft moves relatively along the axial direction from a first position where the rotation restriction is restricted to a second position where the rotation restriction is released, and, in a state where the antenna shaft is rotationally restricted by the second rotation regulating unit, in response to the motor shaft rotating in the second rotation direction, the antenna shaft moves relatively along the axial direction from the second position where the rotation restriction is restricted to the first position where the rotation restriction is released.

[0013] According to a second aspect of the present disclosure, there is provided an antenna driving mechanism as described in the first aspect, further comprising a cover member arranged to face an outer periphery of the antenna shaft, wherein the first rotation regulating portion and the second rotation regulating portion are arranged on an inner periphery of the cover member.

[0014] According to a third aspect of the present disclosure, there is provided the antenna driving mechanism according to the second aspect, further comprising a waveguide structure that transmits microwaves toward the rotating antenna, the cover member being attached to the waveguide structure.

[0015] According to a fourth aspect of the present disclosure, there is provided an antenna driving mechanism as described in the third aspect, wherein the cover member comprises a first member having the first rotation restricting portion and the second rotation restricting portion and constituting the inner circumference, and a second member attached to the waveguide structure by attaching the first member to the inside.

[0016] According to a fifth aspect of the present disclosure, there is provided an antenna driving mechanism described in any one of the second to fourth aspects, wherein the antenna shaft has a protrusion that protrudes laterally intersecting the axial direction, the first rotation regulating portion has a first regulating wall that receives the protrusion in the first rotation direction, and the second rotation regulating portion has a second regulating wall that receives the protrusion in the second rotation direction, and the first regulating wall and the second regulating wall have different positions in the axial direction.

[0017] According to a sixth aspect of the present disclosure, there is provided an antenna driving mechanism as described in the fifth aspect, wherein the first rotation regulating portion is provided adjacent to the first regulating wall and has a first slope whose height gradually increases along the second rotation direction, and the second rotation regulating portion is provided adjacent to the second regulating wall and has a second slope whose height gradually increases along the first rotation direction.

[0018] According to a seventh aspect of the present disclosure, there is provided the antenna driving mechanism according to the fifth or sixth aspect, wherein the antenna shaft further includes a first biasing member that biases the protrusion in a protruding direction.

[0019] According to an eighth aspect of the present disclosure, there is provided an antenna driving mechanism as described in the seventh aspect, wherein the protrusion has a first protrusion protruding to one side in the lateral direction and a second protrusion protruding to the other side in the lateral direction, and the first biasing member biases the first protrusion and the second protrusion in their respective protruding directions.

[0020] According to a ninth aspect of the present disclosure, there is provided an antenna driving mechanism described in any one of the first to eighth aspects, wherein the antenna shaft comprises a first shaft screwed onto the motor shaft and a second shaft arranged on the outside of the first shaft and movable integrally with the first shaft, and the rotating antenna is attached to the second shaft.

[0021] According to a tenth aspect of the present disclosure, there is provided the antenna driving mechanism according to the ninth aspect, further comprising a second biasing member that generates a biasing force in the axial direction between the first shaft and the second shaft.

[0022] According to an eleventh aspect of the present disclosure, there is provided the antenna driving mechanism according to the ninth or tenth aspect, wherein the first shaft is made of resin, and the second shaft is made of metal.

[0023] According to a twelfth aspect of the present disclosure, there is provided an antenna driving mechanism described in any one of the ninth to eleventh aspects, wherein the first shaft has a protrusion protruding laterally intersecting the axial direction, and the second shaft has a through hole through which the protrusion passes in the laterally direction.

[0024] According to a thirteenth aspect of the present disclosure, there is provided an antenna driving mechanism described in any one of the first to twelfth aspects, wherein the rotating antenna is located away from a wall portion constituting the heating chamber when the antenna shaft is in the first position, and contacts the wall portion when the antenna shaft is in the second position.

[0025] According to a fourteenth aspect of the present disclosure, there is provided the antenna driving mechanism according to the thirteenth aspect, wherein the wall portion is a bottom wall portion of the heating chamber.

[0026] According to a fifteenth aspect of the present disclosure, there is provided an antenna driving mechanism comprising: an antenna shaft supporting a rotating antenna for supplying microwaves to a heating chamber; a motor for applying a rotational driving force in a first rotation direction or a second rotation direction to the antenna shaft; a rotation regulating unit for selectively regulating a rotational movement of the antenna shaft so that, when the antenna shaft receives a rotational driving force in the first rotation direction, the axial position of the antenna shaft is positioned at a first position, and, when the antenna shaft receives a rotational driving force in the second rotation direction, the axial position of the antenna shaft is positioned at a second position different from the first position; and a control unit for controlling the rotational direction of the rotational driving force applied by the motor.

[0027] According to a sixteenth aspect of the present disclosure, there is provided a microwave heating device comprising: the antenna driving mechanism; the rotating antenna driven by the antenna driving mechanism; and the heating chamber to which the rotating antenna supplies microwaves.

[0028] (Embodiment) Hereinafter, exemplary embodiments of an antenna driving mechanism and a microwave heating device according to the present disclosure will be described with reference to the accompanying drawings. The present disclosure is not limited to the specific configurations of the following embodiments, and configurations based on similar technical ideas are included in the present disclosure.

[0029] First, an antenna driving mechanism and a microwave heating device according to an embodiment of the present disclosure will be described with reference to FIGS. 1A and 1B.

[0030] 1A and 1B are each a schematic side view of a microwave heating device 2 according to an embodiment.

[0031] 1A and 1B is a cooking device (a so-called "microwave oven") for cooking an object P by using microwaves. The object P may be any type of food ingredient.

[0032] As shown in Figures 1A and 1B, the microwave heating device 2 includes a housing 6 having a heating chamber 4, a door 8, a microwave generator 10, a waveguide structure 12, an antenna driving mechanism 14, a rotating antenna 16, and a control unit 17.

[0033] The housing 6 is a member that constitutes the outer frame of the microwave heating device 2. As shown in Figures 1A and 1B, the housing 6 has a heating chamber 4 inside and is opened and closed by a door 8. The heating chamber 4 is a space for heating an object P to be heated, and has a bottom wall portion 18 on which the object P to be heated can be placed.

[0034] Outside the heating chamber 4, a microwave generator 10, a waveguide structure 12, an antenna driving mechanism 14, a rotating antenna 16 and a control unit 17 are housed in a housing 6.

[0035] The microwave generating device 10 is a device that generates microwaves, and generates microwaves with a frequency of, for example, 300 MHz to 300 GHz. As the microwave generating device 10, for example, a magnetron is used.

[0036] The waveguide structure 12 is a structure for supplying microwaves generated by the microwave generator 10 to the heating chamber 4, and has a waveguide capable of transmitting the microwaves in a predetermined direction (see arrow A1). An antenna driving mechanism 14 and a rotating antenna 16 are connected to the waveguide structure 12.

[0037] Antenna driving mechanism 14 is a mechanism for driving rotating antenna 16. Antenna driving mechanism 14 in this embodiment has a function of rotating rotating antenna 16 and a function of moving rotating antenna 16 up and down.

[0038] Antenna drive mechanism 14 includes an antenna shaft 20 connected to rotating antenna 16 , and a motor 24 having a motor shaft 21 for transmitting a rotational drive force to antenna shaft 20 .

[0039] Antenna shaft 20 is a shaft that rotatably supports rotating antenna 16, and rotates integrally with rotating antenna 16 about rotation axis Ax1. Rotation axis Ax1 extends in the height direction (i.e., the up-down direction) of microwave heating device 2. Antenna shaft 20 is inserted into through hole 28 provided in the upper surface of waveguide structure 12, and forms a coaxial structure together with waveguide structure 12. A cover member 26 is arranged around antenna shaft 20.

[0040] The cover member 26 is a member that covers the antenna shaft 20 from the outside in a movable state. The cover member 26 is attached and fixed to the waveguide structure 12 together with the motor 24. The cover member 26 in this embodiment functions as a "rotation restricting portion" that selectively restricts the rotational movement of the antenna shaft 20. By restricting the rotational movement of the antenna shaft 20, the antenna shaft 20 can be moved up and down.

[0041] Rotating antenna 16 is a member for supplying microwaves transmitted from waveguide structure 12 toward heating chamber 4. Rotating antenna 16 is rotatable together with antenna shaft 20 described above about rotation axis Ax1.

[0042] The control unit 17 is a member that controls the components of the microwave heating device 2, such as the microwave generator 10 and the motor 24, and is configured to include, for example, a microcomputer.

[0043] An antenna driving mechanism 14 having an antenna shaft 20 and a cover member 26 raises the rotating antenna 16 (arrow H1) when rotating the antenna shaft 20 in a first rotation direction R1, as shown in FIG. 1A, and lowers the rotating antenna 16 (arrow H2) when rotating the antenna shaft 20 in a second rotation direction R2, as shown in FIG. 1B.

[0044] According to this operation, by control unit 17 controlling the direction of the rotational driving force on antenna shaft 20, rotating antenna 16 can be moved up and down to a desired height position.

[0045] In this embodiment, when rotating antenna 16 is in the raised position as shown in Fig. 1A, rotating antenna 16 is brought into partial contact with bottom wall 18 of heating chamber 4 via a spacer, which will be described later. When rotating antenna 16 is in the lowered position as shown in Fig. 1B, rotating antenna 16 is not in contact with bottom wall 18 of heating chamber 4, but is disposed below bottom wall 18 with a gap therebetween.

[0046] By contacting the rotating antenna 16 with the bottom wall 18 of the heating chamber 4 via a spacer when the rotating antenna 16 is in the raised position, it becomes easier to maintain a constant distance from the object to be heated P, and the heating state of the object to be heated P by microwaves can be stabilized.

[0047] FIG. 2 is a schematic plan view of rotating antenna 16.

[0048] The rotating antenna 16 shown in Fig. 2 may have any configuration as long as it can supply microwaves toward the heating chamber 4, and may supply microwaves in any form, such as radiation waves or surface waves. In Fig. 2, the rotating antenna 16 is illustrated diagrammatically.

[0049] As shown in FIG. 2, the rotating antenna 16 has an upper surface 29 having a number of spacers 30, 32 thereon.

[0050] The multiple spacers 30, 32 are protrusions that protrude upward from upper surface 29 of rotatable antenna 16 towards heating chamber 4. Spacers 30, 32 contact bottom wall 18 of heating chamber 4 and function as spacers that ensure a gap between bottom wall 18 and upper surface 29. Rotatable antenna 16 contacts bottom wall 18 via spacers 30, 32. Providing spacers 30, 32 can reduce frictional resistance when rotatable antenna 16 rotates in the raised position shown in Figure 1A.

[0051] Spacer 30 is disposed at the center position of top surface 29 of rotatable antenna 16. Spacer 30 in this embodiment overlaps with rotation axis Ax1 of rotatable antenna 16. A pair of spacers 32 are disposed at both ends of top surface 29 of rotatable antenna 16. The arrangement, shape, and number of spacers 30, 32 are not limited to the example shown in FIG.

[0052] Antenna driving mechanism 14 that drives rotating antenna 16 will be described below with reference to FIG. 3A and subsequent figures.

[0053] 3A and 3B are perspective views of the antenna driving mechanism 14. Fig. 3A shows a state in which the antenna shaft 20 is in a raised position (arrow H1), and Fig. 3B shows a state in which the antenna shaft 20 is in a lowered position (arrow H2).

[0054] As shown in Figures 3A and 3B, an attachment portion 42 for attaching rotating antenna 16 is provided at the upper end of antenna shaft 20. In the example shown in Figures 3A and 3B, attachment portion 42 is a plurality of attachment holes.

[0055] As shown in FIGS. 3A and 3B, the cover member 26 provided to surround the outer periphery 23 of the antenna shaft 20 has an upper cover 36 and a lower cover 38.

[0056] The upper cover 36 and the lower cover 38 each have a through hole for inserting the antenna shaft 20, and are connected to each other in the up-down direction. The upper cover 36 has an attachment portion 40 for attachment to the waveguide structure 12 shown in Figures 1A and 1B, and is attached and fixed to the waveguide structure 12 via the attachment portion 40 and a fixing means (not shown) such as a screw. The lower cover 38 prevents the antenna shaft 20 from falling off when attached to the upper cover 36.

[0057] 4 and 5 are exploded perspective views of the antenna driving mechanism 14. FIG.

[0058] 4 and 5, the upper cover 36 has a through hole 46 that accommodates the antenna shaft 20 so that it can move up and down, and a mounting claw 48 for attaching the lower cover 38. The lower cover 38 has a through hole 50 that accommodates the antenna shaft 20 so that it can move up and down, and an insertion portion 52 into which the mounting claw 48 of the upper cover 36 is inserted and engaged. The insertion portion 52 has an insertion hole into which the mounting claw 48 is inserted.

[0059] The cover member 26 includes an upper cover 36 and a lower cover 38 as well as a ring member 44 .

[0060] The ring member 44 is an annular member having a rotation restricting portion 54 for selectively restricting the rotational movement of the antenna shaft 20. The ring member 44 has a through hole 53, and is sandwiched and fixed between the upper cover 36 and the lower cover 38 in a state where it is housed in the through hole 46 of the upper cover 36.

[0061] The ring member 44 of this embodiment has a rotation restricting portion 54 on its inner periphery and a positioning portion 56 on its outer periphery. The positioning portion 56 is a protrusion extending in the vertical direction, and determines the rotational position of the ring member 44 by being disposed in a recess 60 provided on the inner periphery of the upper cover 36 shown in FIG.

[0062] The rotation restricting portion 54 selectively engages with a movable pin 58 provided on the outer circumferential portion 23 of the antenna shaft 20, and selectively restricts the rotational movement of the antenna shaft 20 depending on the rotational direction of the antenna shaft 20. The rotation restricting portion 54 in this embodiment is configured with a concave-convex shape provided on the inner circumferential portion of the ring member 44. The rotation restricting portion 54 will be described in detail later.

[0063] Fig. 6 is a perspective view showing the antenna shaft 20 and the motor screw 22. Fig. 7 and Fig. 8 are exploded perspective views of the antenna shaft 20, and Fig. 9 is a cross-sectional view that shows a schematic transverse section of the antenna shaft 20.

[0064] 6 to 8, the antenna shaft 20 has an inner first shaft 64 and an outer second shaft 66. The first shaft 64 and the second shaft 66 are attached to each other so as to rotate integrally about a rotation axis Ax1. A motor screw 22 constituting the motor shaft 21 is connected to the first shaft 64.

[0065] 6, the first shaft 64 has a threaded portion 68 on its inner periphery. The motor screw 22 connected to the first shaft 64 has a threaded portion 70 on its outer periphery. By connecting the threaded portion 70 to the threaded portion 68, the antenna shaft 20 and the motor shaft 21 are screwed together and can rotate integrally, and the rotational driving force of the motor 24 can be transmitted to the antenna shaft 20.

[0066] A connection hole 72 is provided on the underside of the motor screw 22. A rod-shaped connecting shaft 73 (FIGS. 10A and 10B) extending from the motor 24 is inserted into the connection hole 72. The connecting shaft 73 has a cross-sectional shape other than circular, and rotates integrally with the motor screw 22. The motor shaft 21 is formed by including the motor screw 22 and the connecting shaft 73.

[0067] 4 and 5 in a state where the rotation restricting unit 54 does not restrict the rotation of the antenna shaft 20, the antenna shaft 20 and the motor shaft 21 rotate together, whereas when the rotation restricting unit 54 restricts the rotation of the antenna shaft 20, only the motor shaft 21 rotates. Since the vertical position of the motor shaft 21 is fixed, the antenna shaft 20 screwed to the motor shaft 21 moves up and down relatively along the axial direction L. The direction in which the antenna shaft 20 moves along the axial direction L changes depending on the rotation direction of the motor shaft 21, thereby making it possible to control the up and down movement of the antenna shaft 20.

[0068] As shown in Figures 7 and 8, the antenna shaft 20 has a pair of movable pins 58A, 58B (movable pins 58), a pair of positioning pins 62A, 62B (positioning pins 62), a biasing member 74, and a biasing member 76 as members for connecting the first shaft 64 and the second shaft 66.

[0069] The movable pins 58A, 58B are members that engage with the rotation restricting portion 54 of the cover member 26, and rotate integrally with the antenna shaft 20. The movable pins 58A, 58B may be collectively referred to as "movable pins 58." The positioning pin 62 and other members may also be collectively referred to in a similar manner.

[0070] The movable pins 58A, 58B are protruding parts that protrude radially outward (laterally) from the antenna shaft 20, with the movable pin 58A protruding to one side and the movable pin 58B protruding to the other side.

[0071] The movable pins 58A and 58B have engagement portions 88A and 88B, respectively. The engagement portions 88A and 88B are tip portions for engaging with and contacting the rotation restricting portion 54. In the present embodiment, the engagement portions 88A and 88B have linear side surfaces that come into contact with the restricting wall of the rotation restricting portion 54.

[0072] The movable pins 58A and 58B are inserted through a through hole 80 provided in the first shaft 64 and a through hole 82 provided in the second shaft 66, respectively.

[0073] The biasing member 74 is a member that biases the movable pins 58A, 58B in the respective protruding directions (arrows F1, F2). In this embodiment, the biasing member 74 is a compression spring having one end connected to the movable pin 58A and the other end connected to the movable pin 58B. By using one biasing member 74 to commonly bias the two movable pins 58A, 58B, the number of parts can be reduced.

[0074] The positioning pins 62A, 62B are members for determining the relative rotational positions of the first shaft 64 and the second shaft 66. The positioning pins 62A, 62B are inserted into a through hole 84 provided in the first shaft 64 and a through hole 86 provided in the second shaft 66, respectively. Each of the through holes 84, 86 extends a predetermined length in the circumferential direction R centered on the rotation axis Ax1, so that the positioning pins 62A, 62B come into contact with the side edges that constitute the through holes 84, 86, and the first shaft 64 and the second shaft 66 are positioned relative to each other in the circumferential direction R.

[0075] 9, the movable pins 58A, 58B are inserted into a through hole 82 of the second shaft 66, and a small gap is provided between the movable pins 58A, 58B and the side of the through hole 82 so that the movable pins 58A, 58B can move in the urging direction (arrows F1, F2) of the urging member 74. By providing positioning pins 62A, 62B in addition to the movable pins 58A, 58B, positioning in the circumferential direction R can be performed with greater precision.

[0076] 9, the movable pins 58A, 58B are connected to each other via a biasing member 74, whereas the positioning pins 62A, 62B are not connected to each other and are provided independently. This allows the movable pins 58A, 58B and the positioning pins 62A, 62B to be provided at the same height position (same cross section) in the axial direction L of the antenna shaft 20.

[0077] The biasing member 76 shown in Figures 7 and 8 biases the inner first shaft 64 and the outer second shaft 66 toward each other along the axial direction L. The biasing member 76 is disposed in a recess 78 provided in the upper surface of the first shaft 64 shown in Figure 8, and biases the upper surface portions of the second shaft 66 and the first shaft 64 in directions away from each other (arrow F3). The provision of the biasing member 76 can provide a cushioning effect when the antenna shaft 20 rises and the rotating antenna 16 comes into contact with the bottom wall portion 18. The biasing member 76 is, for example, a compression spring.

[0078] In the antenna shaft 20 having the above configuration, the materials of the respective members are different. Specifically, the first shaft 64, the movable pins 58A, 58B, and the positioning pins 62A, 62B are made of resin, and the second shaft 66 and the biasing members 74, 76 are made of metal.

[0079] By making the outer second shaft 66 out of metal, a coaxial structure can be formed together with the waveguide structure 12 shown in Figs. 1A and 1B. In this embodiment, the inner diameter of the metal second shaft 66 is set to be equal to or less than a quarter of the wavelength of the microwave generated by the microwave generator 10, thereby suppressing the incidence of microwaves into the internal space of the second shaft 66. Therefore, the internal space of the second shaft 66 has less effect on the supply form of the microwaves on the outside, and it becomes possible to incorporate a metal member. For example, durability can be improved by making the biasing members 74 and 76 out of metal. The first shaft 64, the movable pins 58A and 58B, and the positioning pins 62A and 62B are made of resin, thereby reducing costs.

[0080] In the above configuration, the antenna shaft 20 can be made compact by storing each component inside the second shaft 66 made of metal, and the antenna driving mechanism 14 can be made small in size.

[0081] 10A and 10B are cross-sectional views that show schematic longitudinal sections of the peripheral configuration of the antenna shaft 20. Fig. 10A shows a state in which the antenna shaft 20 is in a raised position (arrow H1), and Fig. 10B shows a state in which the antenna shaft 20 is in a lowered position (arrow H2).

[0082] 10A and 10B, the motor screw 22 is rotatably housed inside the lower cover 38, and is connected to the coupling shaft 73 of the motor 24 by being inserted through the through hole 50 of the lower cover 38. A threaded portion 70 provided on the outer periphery of the motor screw 22 and a threaded portion 68 provided on the inner periphery of the first shaft 64 are screwed together, so that the motor shaft 21 and the antenna shaft 20 can rotate integrally around the rotation axis Ax1.

[0083] The ring member 44 having the rotation restricting portion 54 is sandwiched in the vertical direction between the upper cover 36 and the lower cover 38, and is positioned in the circumferential direction R. The rotation restricting portion 54 faces the outer periphery 23 of the antenna shaft 20 so as to engage with the movable pin 58 of the antenna shaft 20.

[0084] The rotation restricting portion 54 is provided in two stages at different positions in the axial direction L. The lower stage rotation restricting portion 54 restricts rotation of the antenna shaft 20 in a first rotation direction R1 while allowing rotation in a second rotation direction R2. The upper stage rotation restricting portion 54 restricts rotation of the antenna shaft 20 in the second rotation direction R2 while allowing rotation in the first rotation direction R1.

[0085] 10A, when the motor shaft 21 and the antenna shaft 20 rotate in the first rotation direction R1, the movable pin 58 is engaged with the lower rotation restricting portion 54 and restricts the rotation in the first rotation direction R1 when the movable pin 58 is located at the lower stage. When the motor shaft 21 rotates in the first rotation direction R1 in this state, the antenna shaft 20 screwed to the motor shaft 21 relatively rises along the axial direction L (arrow H1). Since the upper rotation restricting portion 54 does not restrict the rotation of the antenna shaft 20 in the first rotation direction R1, the antenna shaft 20 can continuously rotate in the first rotation direction R1 when the movable pin 58 is located at the upper stage.

[0086] 10B, when the motor shaft 21 and the antenna shaft 20 rotate in the second rotation direction R2, the movable pin 58 is engaged with the upper rotation restricting portion 54 and restricts the rotation in the second rotation direction R2 when the movable pin 58 is located at the upper stage. When the motor shaft 21 rotates in the second rotation direction R2 in this state, the antenna shaft 20 screwed to the motor shaft 21 relatively descends along the axial direction L (arrow H2). Since the lower rotation restricting portion 54 does not restrict the rotation of the antenna shaft 20 in the second rotation direction R2, the antenna shaft 20 can continuously rotate in the second rotation direction R2 when the movable pin 58 is located at the lower stage.

[0087] Control unit 17 can switch the rotation direction of motor shaft 21 and antenna shaft 20 to perform the rotation and up-down movement of rotatable antenna 16. Because the rotation and up-down movement of rotatable antenna 16 can be achieved by a single motor 24, it becomes easier to achieve both high functionality and compact size of antenna drive mechanism 14 compared to the case where a separate motor for rotation and a motor for up-down movement are provided.

[0088] Next, the configuration and function of the rotation restricting portion 54 and the ring member 44 having the rotation restricting portion 54 will be described with reference to FIG. 11 and subsequent drawings.

[0089] 11 and 12 are perspective views of the ring member 44 viewed from different angles. Fig. 11 is a perspective view viewed from an angle where one positioning portion 56A of a pair of positioning portions 56A, 56B of the ring member 44 is located on the rear side, and Fig. 12 is a perspective view viewed from an angle where the other positioning portion 56B is located on the rear side.

[0090] 11 and 12, the substantially cylindrical ring member 44 has a rotation restricting portion 54 on an inner circumferential portion 89. The rotation restricting portion 54 includes a first rotation restricting portion 90 located at a lower portion in the axial direction L and a second rotation restricting portion 91 located at an upper portion in the axial direction L.

[0091] As shown in Fig. 11, the first rotation restricting portion 90 has a restricting wall 92A and a slope 94A. As shown in Fig. 12, the first rotation restricting portion 90 has a restricting wall 92B and a slope 94B. The first rotation restricting portion 90 shown in Figs. 11 and 12 has a pair of restricting walls 92A, 92B and a pair of slopes 94A, 94B.

[0092] The restricting walls 92A, 92B are walls that protrude radially inward from the inner circumferential portion 89 so as to restrict the rotation of the antenna shaft 20 in the first rotation direction R1. Both restricting walls 92A, 92B face toward the second rotation direction R2. The pair of restricting walls 92A, 92B are provided at positions facing each other and contact the pair of movable pins 58A, 58B at approximately the same timing. Slopes 94A, 94B are provided at positions adjacent to the restricting walls 92A, 92B, respectively.

[0093] The slopes 94A and 94B are inclined walls for assisting the movable pins 58A and 58B to climb over the restricting walls 92A and 92B when the antenna shaft 20 rotates in the second rotation direction R2. The slopes 94A and 94B are smoothly inclined so that their height gradually increases along the second rotation direction R2 in the direction approaching the restricting walls 92A and 92B. By providing the restricting walls 92A and 92B and the slopes 94A and 94B, it is possible to permit rotation of the antenna shaft 20 in the second rotation direction R2 while restricting rotation in the first rotation direction R1.

[0094] As shown in FIGS. 11 and 12, the upper second rotation restricting portion 91 has a pair of restricting walls 96A, 96B and a pair of slopes 98A, 98B.

[0095] The restricting walls 96A, 96B are walls that protrude radially inward from the inner circumferential portion 89 so as to restrict the rotation of the antenna shaft 20 in the second rotation direction R2. Both restricting walls 96A, 96B face toward the first rotation direction R1. The pair of restricting walls 96A, 96B are provided at positions facing each other and contact the pair of movable pins 58A, 58B at approximately the same timing. Slopes 98A, 98B are provided at positions adjacent to the restricting walls 96A, 96B, respectively.

[0096] The slopes 98A and 98B are inclined walls for assisting the movable pins 58A and 58B to climb over the restricting walls 96A and 96B when the antenna shaft 20 rotates in the first rotation direction R1. The slopes 98A and 98B are smoothly inclined so that their height gradually increases along the first rotation direction R1 in the direction approaching the restricting walls 96A and 96B. By providing the restricting walls 96A and 96B and the slopes 98A and 98B, it is possible to permit rotation of the antenna shaft 20 in the first rotation direction R1 while restricting rotation in the second rotation direction R2.

[0097] A partition portion 100 is provided in a middle stage between the lower stage and the upper stage in the inner circumferential portion 89. The partition portion 100 is a wall portion that protrudes inward from the inner circumferential portion 89 so as to separate the lower stage from the upper stage, and extends along the circumferential direction R. The partition portion 100 forms a groove 102 in the lower stage and a groove 104 in the upper stage.

[0098] A portion of the partition portion 100 in the circumferential direction R is interrupted to form a gap 106. The gap 106 extends along the axial direction L and is provided between the first rotation restricting portion 90 and the second rotation restricting portion 91. The first rotation restricting portion 90 and the second rotation restricting portion 91 are separated in the circumferential direction R by the gap 106. By providing the gap 106, a space can be secured in which the movable pins 58A, 58B and the antenna shaft 20 can move up and down along the axial direction L in accordance with the rotation of the motor shaft 21 when the rotation of the movable pins 58A, 58B is restricted by the restricting walls 92A, 92B or the restricting walls 96A, 96B.

[0099] The function and operation of the rotation restricting portion 54 having the above-mentioned configuration will be described with reference to FIGS.

[0100] Fig. 13 is a perspective view for explaining the operation when the movable pins 58A, 58B and the antenna shaft 20 rotate in the first rotation direction R1 when the movable pins 58A, 58B are located at the lower stage. In Fig. 13 and Figs. 14 to 16, the engagement portions 88A, 88B of the movable pins 58A, 58B are diagrammatically illustrated by dotted lines.

[0101] As shown in Fig. 13, when the movable pins 58A, 58B located at the lower stage rotate in the first rotation direction R1, they come into contact with the restricting walls 92A, 92B protruding to face the second rotation direction R2, and the rotation is restricted. In response to the motor shaft 21 rotating in the first rotation direction R1 with the rotation of the antenna shaft 20 restricted, the antenna shaft 20 screwed to the motor shaft 21 relatively rises along the axial direction L (arrow H1). The movable pins 58A, 58B move from the lower stage to the upper stage via the middle stage.

[0102] The movable pins 58A, 58B that have moved to the upper stage rotate in the first rotation direction R1 in the groove 104 of the upper stage.

[0103] FIG. 14 is a perspective view for explaining the operation when the movable pins 58A, 58B and the antenna shaft 20 rotate in the first rotation direction R1 when the movable pins 58A, 58B are located at the upper stage.

[0104] As shown in Fig. 14, when the movable pins 58A, 58B located at the upper stage rotate in the first rotation direction R1, they slide along the slopes 98A, 98B whose height gradually increases along the first rotation direction R1, and climb over the restriction walls 96A, 96B. When the movable pins 58A, 58B slide along the slopes 98A, 98B, the biasing members 74 slide while contracting. This allows the movable pins 58A, 58B to rotate continuously in the first rotation direction R1.

[0105] FIG. 15 is a perspective view for explaining the operation when the movable pins 58A, 58B and the antenna shaft 20 rotate in the second rotation direction R2 when the movable pins 58A, 58B are located at the upper stage.

[0106] As shown in Fig. 15, when the movable pins 58A, 58B located at the upper stage rotate in the second rotation direction R2, they come into contact with the restricting walls 96A, 96B protruding to face the first rotation direction R1, and the rotation is restricted. In response to the motor shaft 21 rotating in the second rotation direction R2 with the rotation of the antenna shaft 20 restricted, the antenna shaft 20 screwed to the motor shaft 21 relatively descends along the axial direction L (arrow H2). The movable pins 58A, 58B move from the upper stage to the lower stage via the middle stage.

[0107] The movable pins 58A, 58B that have moved to the lower stage rotate in the second rotation direction R2 in the groove 102 of the lower stage.

[0108] FIG. 16 is a perspective view for explaining the operation when the movable pins 58A, 58B and the antenna shaft 20 rotate in the second rotation direction R2 when the movable pins 58A, 58B are located at the lower stage.

[0109] As shown in Fig. 16, when the movable pins 58A, 58B located at the lower stage rotate in the second rotation direction R2, they slide along the slopes 94A, 94B whose height gradually increases along the second rotation direction R2, and climb over the restriction walls 92A, 92B. When the movable pins 58A, 58B slide along the slopes 94A, 94B, the biasing member 74 slides while contracting. This allows the movable pins 58A, 58B to rotate continuously in the second rotation direction R2.

[0110] With the above configuration, it is possible to realize the rotation and vertical movement functions of rotatable antenna 16 by using movable pins 58A, 58B of antenna shaft 20 and rotation restricting portion 54 of ring member 44. As shown in Figures 3A and 3B, these operations can be realized by cover member 26 incorporating ring member 44, and antenna shaft 20 provided inside cover member 26, which leads to the miniaturization of antenna drive mechanism 14.

[0111] 7 and 8, the antenna shaft 20 can be made smaller by arranging the movable pin 58, the positioning pin 62, and the biasing member 74 inside the second shaft 66. By making the second shaft 66 out of metal, a metal member can be arranged in the internal space of the second shaft 66, and by making the biasing members 74 and 76 out of metal, durability can be increased.

[0112] (Action and effect) As described above, the antenna drive mechanism 14 of the present embodiment includes the antenna shaft 20 supporting the rotating antenna 16 for supplying microwaves to the heating chamber 4, the motor shaft 21 screwed onto the antenna shaft 20 and rotatable integrally with the antenna shaft 20 and driven to rotate in a first rotation direction R1 or a second rotation direction R2, a first rotation restricting portion 90 selectively restricting the rotation of the antenna shaft 20 in the first rotation direction R1, and a second rotation restricting portion 91 selectively restricting the rotation of the antenna shaft 20 in the second rotation direction R2. When the motor shaft 21 is subject to rotation restriction by the first rotation restriction unit 90, as the motor shaft 21 rotates in the first rotation direction R1, the antenna shaft 20 moves relatively along the axial direction L from a lowered position (first position) where the rotation restriction is imposed to an elevated position (second position) where the rotation restriction is released, and when the motor shaft 21 is subject to rotation restriction by the second rotation restriction unit 91, as the motor shaft 21 rotates in the second rotation direction R2, the antenna shaft 20 moves relatively along the axial direction L from the elevated position where the rotation restriction is imposed to a lowered position where the rotation restriction is imposed.

[0113] With this configuration, by switching the rotation direction of motor shaft 21, the position in axial direction L of antenna shaft 20 can be changed, thereby axially moving rotating antenna 16. This makes it possible to achieve rotational and axial movement of rotating antenna 16 with a simple configuration, thereby achieving both high functionality and compact size of antenna drive mechanism 14.

[0114] Moreover, the antenna driving mechanism 14 of the present embodiment further includes a cover member 26 provided to face the outer circumferential portion 23 of the antenna shaft 20, and the first rotation restricting portion 90 and the second rotation restricting portion 91 are provided on an inner circumferential portion 89 of the cover member 26. According to this configuration, the rotation restricting portions 90, 91 can be formed using the inner circumferential portion 89 of the cover member 26.

[0115] Moreover, antenna driving mechanism 14 of the present embodiment further includes waveguide structure 12 that transmits microwaves toward rotating antenna 16, and cover member 26 is attached to waveguide structure 12. With this configuration, cover member 26 can be easily provided.

[0116] Moreover, in the antenna driving mechanism 14 of the present embodiment, the cover member 26 includes a ring member 44 (first member) having a first rotation restricting portion 90 and a second rotation restricting portion 91 to form an inner periphery 89, and an upper cover 36 (second member) to which the ring member 44 is attached inside and which is attached to the waveguide structure 12. With this configuration, it is easy to arrange the shapes of the rotation restricting portions 90 and 91 provided on the ring member 44 while attaching the upper cover 36 to the waveguide structure 12.

[0117] In the antenna driving mechanism 14 of this embodiment, the antenna shaft 20 has movable pins 58A, 58B (protruding portions) protruding laterally intersecting the axial direction L, the first rotation restricting portion 90 has restricting walls 92A, 92B (first restricting walls) that receive the movable pins 58A, 58B in a first rotation direction R1, and the second rotation restricting portion 91 has restricting walls 96A, 96B (second restricting walls) that receive the movable pins 58A, 58B in a second rotation direction R2, and the restricting walls 92A, 92B and the restricting walls 96A, 96B are located at different positions in the axial direction L. With this configuration, the rotation restricting portions 90, 91 can be realized with a simple structure.

[0118] In the antenna driving mechanism 14 of this embodiment, the first rotation restricting portion 90 is provided adjacent to the restricting walls 92A, 92B (first restricting walls) and has slopes 94A, 94B (first slopes) whose height gradually increases along the second rotation direction R2, and the second rotation restricting portion 91 is provided adjacent to the restricting walls 96A, 96B (second restricting walls) and has slopes 98A, 98B (second slopes) whose height gradually increases along the first rotation direction R1. According to this configuration, the restricting walls 92A, 92B can be configured to restrict the rotation of the antenna shaft 20 in the first rotation direction R1 while allowing the rotation in the second rotation direction R2, and the restricting walls 96A, 96B can be configured to restrict the rotation of the antenna shaft 20 in the second rotation direction R2 while allowing the rotation in the first rotation direction R1.

[0119] In the antenna driving mechanism 14 of the present embodiment, the antenna shaft 20 further includes a biasing member 74 (first biasing member) that biases the movable pins 58A, 58B (protruding portions) in the protruding direction. With this configuration, by biasing the movable pins 58A, 58B in the protruding direction, the movable pins 58A, 58B can be more reliably brought into contact with the restriction walls 92A, 92B, 96A, 96B.

[0120] In the antenna driving mechanism 14 of this embodiment, the movable pins 58A, 58B (protruding portions) have a movable pin 58A (first movable pin) protruding on one side in the horizontal direction and a movable pin 58B (second movable pin) protruding on the other side in the horizontal direction, and the biasing member 74 (first biasing member) biases the movable pins 58A, 58B in their respective protruding directions. With this configuration, the use of a common biasing member 74 can reduce costs.

[0121] Furthermore, in antenna drive mechanism 14 of the present embodiment, antenna shaft 20 includes a first shaft 64 that screws onto motor shaft 21, and a second shaft 66 that is disposed on the outside of first shaft 64 and is movable integrally with first shaft 64, and rotating antenna 16 is attached to second shaft 66. With this configuration, first shaft 64 and second shaft 66 can be made to have different shapes and materials.

[0122] Moreover, antenna driving mechanism 14 of the present embodiment further includes biasing member 76 (second biasing member) that generates a biasing force in axial direction L between first shaft 64 and second shaft 66. With this configuration, a cushioning effect can be generated when rotating antenna 16 comes into contact with another object (for example, bottom wall portion 18 of heating chamber 4).

[0123] In the antenna driving mechanism 14 of the present embodiment, the first shaft 64 is made of resin, and the second shaft 66 is made of metal. With this configuration, by making the second shaft 66 out of metal, a coaxial structure for feeding microwaves can be created, and by making the first shaft 64 out of resin, weight reduction and cost reduction can be achieved.

[0124] Furthermore, in the antenna driving mechanism 14 of this embodiment, the first shaft 64 has movable pins 58A, 58B (protruding portions) that protrude in a lateral direction (radial direction of the antenna shaft 20) intersecting the axial direction L, and the second shaft 66 has a through hole 82 through which the movable pins 58A, 58B pass in the lateral direction. With this configuration, while dividing the antenna shaft 20 into two shafts 64, 6, the movable pins 58A, 58B for engaging with the rotation restricting portions 90, 91 can be protruded outward.

[0125] Furthermore, in antenna drive mechanism 14 of the present embodiment, rotating antenna 16 is located away from bottom wall 18 (wall) constituting heating chamber 4 when antenna shaft 20 is in the lowered position (first position), and contacts bottom wall 18 when antenna shaft 20 is in the raised position (second position). With this configuration, by bringing rotating antenna 16 into contact with bottom wall 18 when antenna shaft 20 approaches heating chamber 4, the radiation mode of microwaves can be stabilized, leading to uniform cooking results.

[0126] Furthermore, in antenna driving mechanism 14 of the present embodiment, rotating antenna 16 comes into contact with bottom wall portion 18 of heating chamber 4. With this configuration, microwaves can be fed from below heating chamber 4.

[0127] As described above, the antenna driving mechanism 14 of this embodiment includes an antenna shaft 20 that supports a rotating antenna 16 for supplying microwaves to the heating chamber 4, a motor 24 that applies a rotational driving force in a first rotational direction R1 or a second rotational direction R2 to the antenna shaft 20, a rotation regulating unit 54 that selectively regulates the rotational operation of the antenna shaft 20 so that when the antenna shaft 20 receives a rotational driving force in the first rotational direction R1, the position of the axial direction L of the antenna shaft 20 is positioned in a descending position (first position), and when the antenna shaft 20 receives a rotational driving force in the second rotational direction R2, the position of the axial direction L of the antenna shaft 20 is positioned in an ascending position (second position) different from the descending position; and a control unit 17 that controls the rotational direction of the rotational driving force by the motor 24.

[0128] With this configuration, by switching the rotation direction of the rotational drive force by motor 24, the position in axial direction L of antenna shaft 20 can be changed, thereby axially moving rotating antenna 16. This makes it possible to achieve rotational and axial movement of rotating antenna 16 with a simple configuration, thereby achieving both high functionality and compactness of antenna drive mechanism 14.

[0129] As described above, the microwave heating device 2 of the present embodiment includes the antenna driving mechanism 14, the rotating antenna 16 driven by the antenna driving mechanism 14, and the heating chamber 4 to which microwaves are supplied by the rotating antenna 16. With this configuration, it is possible to achieve the same effects as those achieved by the antenna driving mechanism 14.

[0130] Although the invention of the present disclosure has been described above with reference to the above-mentioned embodiment, the invention of the present disclosure is not limited to the above-mentioned embodiment. For example, in the present embodiment, the case where the movable pins 58A and 58B are movable and the regulating walls 92A, 92B, 96A, and 96B are fixed is described, but the invention is not limited to such a case. For example, the movable pins may be fixed and the regulating walls may be movable. In this case, the urging member 74 that urges the movable pins outward may be omitted, and a urging member that urges the regulating walls inward may be provided. On the other hand, in the configuration in which the movable pins 58A and 58B are movable and urged by the urging member 74 as in the embodiment, the metal urging member 74 can be accommodated inside the metal second shaft 66, and the highly durable urging member 74 can be used without affecting the supply form of the microwaves, which also leads to a reduction in size of the antenna shaft 20.

[0131] In the above embodiment, a case was described in which a pair of each of the movable pins 58A, 58B, positioning pins 62A, 62B, regulating walls 92A, 92B, slopes 94A, 94B, regulating walls 96A, 96B, and slopes 98A, 98B is provided, but this is not limited to the case, and it is sufficient to provide at least one of each.

[0132] Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various modifications and alterations will be apparent to those skilled in the art. Such modifications and alterations should be understood to be included within the scope of the invention as defined by the appended claims, unless they deviate from the scope of the invention. In addition, changes in the combination and order of elements in each embodiment may be made without departing from the scope and spirit of the present disclosure.

[0133] Of the various modifications of the embodiment, any of the modifications can be appropriately combined to obtain the respective effects. [Industrial Applicability]

[0134] The present disclosure is applicable to any antenna driving mechanism that drives a rotating antenna and a microwave heating device including the same. [Explanation of symbols]

[0135] 2. Microwave heating device 4 Heating chamber 14 Antenna drive mechanism 16 Rotating Antenna 17 Control section 20 Antenna shaft 21 Motor shaft 24 Motor 54 Rotation restriction part 90 First rotation restriction part 91 Second rotation restriction part L axis direction R1 First rotation direction R2 Second rotation direction

Claims

1. An antenna shaft that supports a rotary antenna for supplying microwaves to a heating chamber, a motor shaft that is rotatable integrally with the antenna shaft and is rotationally driven in a first rotation direction or a second rotation direction, and a rotation restricting portion that selectively restricts the rotational movement of the antenna shaft according to the rotation direction of the motor shaft. The antenna drive mechanism is provided, wherein the antenna shaft moves relatively in the axial direction according to the restriction of the rotation restricting portion.

2. Further comprising a cover member provided so as to face the outer peripheral portion of the antenna shaft, wherein the rotation restricting portion is provided on the inner peripheral portion of the cover member. The antenna drive mechanism according to claim 1.

3. Further comprising a waveguide structure that transmits microwaves toward the rotary antenna, wherein the cover member is attached to the waveguide structure. The antenna drive mechanism according to claim 2.

4. The cover member includes a first member that has the rotation restricting portion and constitutes the inner peripheral portion, and a second member that is attached to the inside of the first member and is attached to the waveguide structure. The antenna drive mechanism according to claim 3.

5. The antenna shaft has a protruding portion that protrudes in a lateral direction intersecting the axial direction, wherein the rotation restricting portion has a first restricting wall that receives the protruding portion in the first rotation direction and a second restricting wall that receives the protruding portion in the second rotation direction, wherein the first restricting wall and the second restricting wall are different from each other in the axial direction. The antenna drive mechanism according to claim 2.

6. The rotation restricting portion includes a first slope that is provided adjacent to the first restricting wall and has a gradually increasing height along the second rotation direction, and a second slope that is provided adjacent to the second restricting wall and has a gradually increasing height along the first rotation direction. The antenna drive mechanism according to claim 5.

7. The antenna shaft further includes a first biasing member that biases the protruding portion in the protruding direction. The antenna drive mechanism according to claim 5.

8. The protruding portion has a first protruding portion that protrudes to one side in the lateral direction and a second protruding portion that protrudes to the other side in the lateral direction, wherein the first biasing member biases the first protruding portion and the second protruding portion in their respective protruding directions. The antenna drive mechanism according to claim 7.

9. The antenna shaft includes a first shaft screwed onto the motor shaft, and a second shaft disposed outside the first shaft and movable integrally with the first shaft. The rotary antenna is attached to the second shaft, and the antenna drive mechanism according to claim 1.

10. The antenna drive mechanism according to claim 9, further comprising a second biasing member that generates a biasing force in the axial direction between the first shaft and the second shaft.

11. The antenna drive mechanism according to claim 9, wherein the first shaft is made of resin and the second shaft is made of metal.

12. The antenna drive mechanism according to claim 9, wherein the first shaft has a protruding portion protruding in a lateral direction intersecting the axial direction, and the second shaft has a through hole through which the protruding portion passes in the lateral direction.

13. The rotary antenna is at a position away from the wall portion constituting the heating chamber when the antenna shaft is in the first position, and contacts the wall portion when the antenna shaft is in the second position, and the antenna drive mechanism according to claim 1.

14. The wall portion is the bottom wall portion of the heating chamber, and the antenna drive mechanism according to claim 13.

15. The rotation restricting portion includes a first rotation restricting portion that selectively restricts the rotation of the antenna shaft in the first rotation direction, and a second rotation restricting portion that selectively restricts the rotation in the second rotation direction. In a state where the rotation restriction of the first rotation restricting portion is received, in response to the motor shaft rotating in the first rotation direction, from a first position where the rotation restriction is received, to a second position where the rotation restriction is released, it moves relatively along the axial direction. The antenna shaft moves relatively along the axial direction from the second position where the rotation restriction of the second rotation restricting portion is received to the first position where the rotation restriction is released in response to the motor shaft rotating in the second rotation direction in a state where the rotation restriction of the second rotation restricting portion is received, and the antenna drive mechanism according to claim 1.

16. An antenna shaft that supports a rotary antenna for supplying microwaves to a heating chamber. A motor that applies a rotational driving force in a first rotation direction or a second rotation direction to the antenna shaft. When the antenna shaft receives the rotational driving force in the first rotational direction, the axial position of the antenna shaft is arranged at a first position, and when the antenna shaft receives the rotational driving force in the second rotational direction, the axial position of the antenna shaft is arranged at a second position different from the first position. A rotation restricting unit that selectively restricts the rotational operation of the antenna shaft. An antenna drive mechanism comprising:

17. The antenna drive mechanism according to claim 16, further comprising a control unit that controls the rotational direction of the rotational driving force by the motor.

18. A microwave heating apparatus comprising: the antenna drive mechanism according to any one of claims 1 to 17; the rotary antenna driven by the antenna drive mechanism; and a heating chamber to which the rotary antenna supplies microwaves.

Images