JP2007005955A - Connection structure and method of waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure and a connection method of a waveguide capable of achieving connection without any gaps without increasing costs and working hours. <P>SOLUTION: The waveguide is prepared which comprises a flange at a transmission line opening and a projection projecting higher than a flange surface at the periphery of the transmission line opening. The projection is deformed at nearly the same height as the flange surface by pressure applied when connecting the waveguide to another member. Pressure is applied to another member and the projection, and the projection is deformed to nearly the same height as the flange surface, thus connecting the projection surface and the flange surface, and the contacting surface of another member nearly without any gaps. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a waveguide connection structure and connection method that are electromagnetic wave transmission lines such as microwaves and millimeter waves, and more particularly to a waveguide connection structure and connection method that can prevent radio wave leakage and in-tube discharge.

  When transmitting electromagnetic waves such as microwaves and millimeter waves, a waveguide capable of low-loss transmission is used. FIG. 8 shows a connection portion of a general waveguide. A flange 4 is formed in the transmission path opening 1 of the waveguide, and a flange surface 2 of the flange 4 is connected to another member, for example, a flange formed in the transmission path opening of another waveguide. Bonded and waveguides are connected. In this connection structure, a screw is passed through the screw hole 3 provided in the flange 4, and a predetermined pressure contact force is applied to the flange for connection.

  In such a waveguide connection structure, the flange surface needs to be in close contact with each other in order to suppress electromagnetic wave leakage, in-tube discharge, and transmission loss. For this reason, it is necessary to process the flange surface with high accuracy so as to reduce the unevenness, and it is necessary to press the connection surface uniformly, resulting in an increase in man-hours and cost for forming the connection portion. For this reason, the connection work is easy, and even if the waveguide structure (see Patent Document 1) that prevents the generation of a gap in the connection portion generated on the inner wall of the waveguide or the flatness of the flange surface is poor, the gap from the gap A connection structure (see Patent Document 2) that prevents leakage of radio waves has been proposed.

Furthermore, a structure provided with a protrusion on the periphery of the transmission line opening is disclosed in Patent Document 3, and the waveguides are connected by this protrusion. In this way, it is sufficient to process only the protrusions without unevenness, and a structure in which a good waveguide connection with little loss can be realized at low cost.
JP 2004-207941 A Japanese Patent Publication No. 7-44361 Japanese Utility Model Publication No. 3-70401

  Conventionally proposed waveguides and their connection structures require man-hours for connecting the waveguides and new parts for connection, leading to an increase in product cost. In addition, in order to connect easily, it is necessary to improve the flatness of the connecting surface of the waveguide. After the waveguide is manufactured by die casting or pressing, surface processing to eliminate the unevenness on the surface of the connecting surface is performed. It was necessary. The present invention has been made in view of such a situation, and an object of the present invention is to provide a waveguide connection structure and a connection method capable of realizing a connection without a gap in a connection portion without increasing costs and man-hours. And

  In order to achieve the above object, a waveguide connection structure according to claim 1 of the present application includes a flange at a transmission path opening, and a protrusion protruding above the flange surface at the periphery of the transmission path opening. In the waveguide connection structure, the projection surface and the flange surface deformed to substantially the same height as the flange surface are connected to a contact surface of another member with almost no gap. It is.

  Also, the waveguide connection method according to claim 2 of the present application is a waveguide connection method including a flange at the transmission path opening and a protrusion protruding higher than the flange surface at the periphery of the conduction path opening. A step of preparing a waveguide provided with the protrusion that deforms to substantially the same height as the flange surface by a pressure applied when connecting the waveguide and another member; and The pressure is applied to the protrusion to deform the protrusion to substantially the same height as the flange surface, and the protrusion surface, the flange surface, and the contact surface of the other member are connected with almost no gap. It is characterized by doing.

  According to the present invention, a waveguide whose protrusion is deformed by the pressure (pressure contact force) applied at the time of connection is used, and the height and width of the protrusion are approximately the same as the flange surface without the occurrence of burrs due to deformation. Therefore, it is possible to provide a waveguide connection structure and a connection method that can be connected without a gap without requiring a special part or a connection method only by setting a low height and a contact area.

  In the waveguide connection structure according to the present invention, the protruding portion after connection is laterally arranged so as to be approximately the same height as the flange surface in accordance with the surface state (irregularity, height, etc.) of another member to be connected by the pressure applied during connection. Since it is deformed in the direction (buckling occurs) and is in close contact with another member, it can be connected without gaps, allowing leakage of electromagnetic waves at the connection part, occurrence of in-tube discharge, transmission loss There is an advantage that there is no occurrence of.

  Further, in the waveguide connection method of the present invention, the flange surface and the projection surface of the waveguide may be flat as manufactured by a die casting method or a press method, and surface processing is performed to eliminate surface irregularities. Since there is no need to add, there is no increase in the manufacturing cost of the waveguide. Furthermore, the method of applying a pressure contact force to the flange surface may be a conventional screw connection, and there is an advantage that the number of man-hours for connecting is not increased.

  Hereinafter, the waveguide connection structure and connection method of the present invention will be described in detail according to the manufacturing process with reference to the drawings.

  FIG. 1 shows a waveguide connection used in the connection structure and connection method of the present invention. Compared with the connection portion of the general waveguide described with reference to FIG. 8, the protrusion 5 is provided on the periphery of the transmission line opening 1. The protrusion 5 protrudes most in the flange surface 2 and comes into contact with the surface of another member when connected to another member such as a waveguide.

  Thus, when connecting the flange surface 2 provided with the protrusion 5 to another member such as a waveguide, a screw is passed through the screw hole 3 and fixed. As a result, a pressing force is applied between the protruding portion 5 and another member, and the protruding portion 5 is laterally deformed by this pressing force (buckling occurs), and the height of the protruding portion 5 is the same as that of the flange surface 2. It becomes almost the same height. At this time, since the surface of the protrusion 5 is deformed along the unevenness of the surface of another member to be connected, the surface of the protrusion 5 and the flange surface 2 are connected to another member with almost no gap.

  In order to realize such a connection structure, the height h of the protrusion 5 is set to a predetermined height that satisfies the following conditions. First, as schematically shown in a cross-sectional view of the waveguide in the signal transmission direction in FIG. 2A, the height h is set to be higher than ½ of the height h1 of the unevenness of the flange surface 2. If it is lower than the height h1 / 2, when connecting to another member, the unevenness of the flange surface 2 comes into contact first, which is the same as the conventional connection structure. If the height h of the projection 5 is too high, even if the projection 5 is connected to another member and the surface of the projection 5 is deformed, only the projection 5 is connected, the flange surface 2 is not connected, and the gap Will remain. Then, surface processing for improving the flatness of the surface is necessary so that the height h2 of the unevenness on the surface of the protrusion 5 (equivalent to h1 when formed simultaneously) is not increased. Therefore, the height h of the protruding portion 5 is substantially the same as the flange surface 2 because the protruding portion 5 is deformed in the lateral direction due to the pressure contact force applied when connecting to another member, and the height of the protruding portion 5 is lowered. Try to make it low enough to be high. Therefore, the height h of the protrusion 5 needs to be appropriately set according to the material of the waveguide, the pressing force applied when connecting, and the area of the protrusion 5.

For example, in an X-band waveguide made of aluminum die cast, the strength against the stress of the waveguide is 180 N / mm ² (0.2% proof stress), and torque is 0.2 to 0.3 kgm with four screws. When tightened, the pressing force of the joint surface is about 300 N, and the height h1 of the unevenness is about 0.2 to 0.6 mm.

  The amount of deformation of the protrusion 5 varies depending on the area of the contact portion. That is, even when the same pressure contact force is applied, the deformation amount is small when the area of the contact portion is large, and the deformation amount is large when the area of the contact portion is small. Therefore, by adjusting the contact area as appropriate according to the magnitude of the pressure contact force applied and the strength of the waveguide material, adjustment is performed so that a desired connection is made within the range of the height of the protrusion 5 described above. There is a need.

For example, when the waveguide having the structure shown in FIG. 2B is connected to another member by screwing, if the following relationship is established, the protrusion 5 is deformed.
F> PL × S = PL × {2w × (a + b + 2w)}
Here, F is the pressure force (N) applied to the contact surface, PL is the strength of the waveguide material against stress (N / mm ² ), S is the area of the protrusion (mm ² ), and a is a rectangular waveguide. Is the short side dimension (mm) of the rectangular waveguide, and w is the width (mm) of the protrusion.

  FIG. 3 shows the height of the protrusion 5 when the width w of the protrusion 5 having a height of 0.2 (mm) is changed under the above condition where the pressure contact force F is 300 (N). As shown in the figure, it is confirmed that deformation (buckling) occurs when the width w of the protrusion 5 is 3.57 (mm) or less, and when the width w of the protrusion 5 is increased, the protrusion 5 No deformation was confirmed. Therefore, it can be seen that the deformation of the protrusion 5 can be realized by setting the width w of the protrusion 5 to at least 3.57 (mm) or less under the above conditions. On the other hand, if the width w of the protrusion 5 becomes too narrow, the deformed protrusion may become a burr and reduce the flatness of the joint surface. If the width w of the protrusion is experimentally narrower than 0.8 (mm), the protrusion is partially deformed to become a burr, and the height of the protrusion (burr thickness) may increase. confirmed. Therefore, the width w of the protrusion 5 is 0.8 (mm) as shown in FIG. 3 in a range where desired deformation occurs and no burrs occur according to the pressure contact force applied to the contact surface. ) ≦ w ≦ 3.57 (mm), it is necessary to set appropriately.

  Also, under such conditions, when the height h of the protrusion 5 is set so as to satisfy h1 / 2 ≦ h ≦ 2 · h1, the protrusion 5 is laterally deformed by the pressure contact force applied when connecting to another member. It has been confirmed that a connection structure can be formed in which the protrusion 5 is deformed in the direction, the height of the protrusion 5 is reduced, and the height is substantially the same as the flange surface 2.

  FIG. 4 shows an application example in which a magnetron is attached to the waveguide of the present invention and the waveguide is used as an input / output part of the magnetron. Since the electromagnetic wave generated in the magnetron tube part 6 is radiated into the waveguide pipe 7, the transmission line opening 1 is provided. In this embodiment, the projection 5 is provided on the peripheral edge of the transmission path opening 1 of the magnetron output flange 8. As a result, like the waveguide described in the first embodiment, when the magnetron output flange 8 is connected to, for example, another waveguide, no gap is generated on the connection surface, and electromagnetic waves leak even if high power is passed. There is no structure in which no discharge occurs in the tube. On the other hand, the heat generated in the magnetron tube part 6 can be efficiently dissipated through the waveguide connection surface, and the temperature rise can be prevented.

  FIG. 5 shows an embodiment in which the connection structure of the present invention is applied to a circular waveguide. In the case of a circular waveguide, a structure similar to that of a rectangular waveguide can be used. That is, the height h of the protrusion 5 is set to be higher than ½ of the height h1 of the unevenness of the flange surface 2. This is because when the height of the unevenness is lower than h1, the flange surface 2 comes into contact first when connecting to another member, and is not different from the conventional connection structure. If the height h of the protrusion 5 is too high, only the protrusion 5 is connected and the flange surface 2 is not connected when connected to another member. Then, surface processing for improving the flatness of the surface is required so that the height h2 of the unevenness on the surface of the protrusion 5 is not increased. Therefore, the height h of the protruding portion 5 is substantially the same as the flange surface 2 because the protruding portion 5 is deformed in the lateral direction due to the pressure contact force applied when connecting to another member, and the height of the protruding portion 5 is lowered. The surface is formed low enough to form a surface.

For example, an aluminum die-cast waveguide has a strength against the stress of the waveguide of 180 N / mm ² (0.2% proof stress) and is tightened with a torque of 0.2 to 0.3 kgm with four screws. In addition, the pressure contact force of the joint surface is about 300N.

  The amount of deformation of the protrusion 5 varies depending on the area of the contact portion. That is, even when the same pressure contact force is applied, the deformation amount is small when the contact portion area is large, and the deformation amount is large when the contact area is small. Therefore, by adjusting the contact area as appropriate according to the magnitude of the pressure contact force applied and the strength of the waveguide material, adjustment is performed so that a desired connection is made within the range of the height of the protrusion 5 described above. There is a need.

For example, when connecting the two waveguides with screws, if the following relationship is established, the projections will be deformed.
F> PL × S = PL × {wπ × (2r + w)}
Here, F is a pressure contact force (N) applied to the contact surface, PL is a strength of the waveguide material against stress (N / mm ² ), S is an area of the protrusion (mm ² ), and r is a circular waveguide. In-pipe radius (mm), w is the width (mm) of the protrusion.

  In the case of a circular waveguide, similarly to the above-described rectangular waveguide, deformation (buckling) occurs, and by setting the width w of the protrusion in a range where the deformed protrusion does not become a burr, the protrusion 5 It can be deformed and connected to another member without a gap.

  As mentioned above, although the Example of this invention was described, it cannot be overemphasized that this invention is not limited to these. For example, if the pressure contact force applied at the time of joining changes, the width w of the projection portion needs to be changed. If the material constituting the waveguide changes, the pressure contact force, width, and height of the projection portion need to be appropriately changed. is there.

  Further, as shown in FIG. 6, the protruding portion 5 may be provided with a chamfered portion 9, and the wall surface of the protruding portion 5 may be inclined toward the outside from the transmission path opening 1. By doing in this way, when the projection part 5 deform | transforms (buckling), the deformation | transformation member which deform | transformed in a waveguide does not enter, and there exists an effect that a transmission loss can be suppressed. In this case, the width w needs to be appropriately changed according to the inclination of the chamfered portion 9.

  Furthermore, as shown in FIG. 7, it is possible to have a structure in which the screw hole edge portion 10 is formed on the flange surface 2 together with the projection portion 5. In this case, the height of the protrusion 5 is set to be the same as the height of the screw hole edge 10 or higher than the height of the screw hole edge 10. If it does in this way, when connecting to another member, since both projection part 5 and screw hole edge part 10 will contact another member, and it will become a structure which changes and connects, the unevenness of the surface of flange surface 2 ( Even if it is large (corresponding to h1 in FIG. 2), it is possible to connect without a gap without being affected by the unevenness of the flange surface 2. In consideration of the fact that the contact hole area is increased by providing the screw hole edge portion 10 as compared with the structure including only the protrusion portion 5, the height of the protrusion portion 5, the screw hole edge portion, and the contact area. Needless to say, etc. need to be set.

It is a figure explaining the connection part of the rectangular waveguide used for this invention. It is a figure explaining the connection part of the rectangular waveguide used for this invention. It is a figure showing the relationship between the width | variety and height of the projection part of the waveguide used for this invention. It is a figure explaining the application example using the waveguide used for this invention. It is a figure explaining the connection part of the circular waveguide used for this invention. It is a figure explaining another connection part of the rectangular waveguide used for this invention. It is a figure explaining another connection part of the rectangular waveguide used for this invention. It is a figure explaining the connection part of a general waveguide.

Explanation of symbols

1; transmission path opening, 2; flange surface, 3; screw hole, 4; flange, 5;
6; magnetron bulb, 7; in waveguide tube, 8; magnetron output flange,
9; Chamfered portion, 10; Edge of screw hole

Claims (2)

In the connection structure of the waveguide provided with a flange at the transmission line opening, and provided with a protrusion protruding higher than the flange surface at the periphery of the transmission line opening,
The waveguide connection structure, wherein the protrusion surface and the flange surface deformed to substantially the same height as the flange surface are connected to a contact surface of another member with almost no gap. In the connection method of the waveguide provided with a flange in the transmission path opening, and provided with a protrusion protruding higher than the flange surface on the periphery of the conduction path opening,
Preparing a waveguide having the protrusions deformed to substantially the same height as the flange surface by pressure applied when connecting the waveguide and another member;
The pressure is applied to the another member and the protrusion, the protrusion is deformed to substantially the same height as the flange surface, and the protrusion surface, the flange surface, and the contact surface of the other member are formed. A method of connecting waveguides, characterized in that the connections are made almost without any gaps.

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