JP2008025785A - Hollow tube, hollow tube connecting structure, and hollow tube connecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hollow tube, a hollow tube connecting structure, and a hollow tube connecting method securing airtightness of a connection part without using a special member when connecting hollow tubes. <P>SOLUTION: A first hollow tube is provided with a protruding type tapered part having an outer diameter becoming larger from one end toward the other end, and a second hollow tube is provided with a recessed type tapered part having an inner diameter becoming smaller from one end toward the other end, and fitting together with the protruding type tapered part. An outer circumference of a cross section of the protruding type tapered part and an inner circumference of a cross section of the recessed type tapered part, include curves when cut by a plane perpendicular to a predetermined center axis passing through a hollow part of the tapered parts. Curved parts of the cross sections of the two tapered parts deform thereby, and positive airtightness is secured. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a hollow tube, a connection structure for a hollow tube, and a connection method, and in particular, a hollow tube capable of being connected with another hollow tube with high adhesion, a hollow tube connection structure, and a hollow tube connection method. About.

  Hollow tubes having a hollow interior are used for various fluid movements and electromagnetic wave propagation. The hollow tube needs to move or propagate an object or electromagnetic wave passing through the hollow part to the destination without leaking. Therefore, the airtightness of the connection part of the hollow tube is very important.

  One type of such a hollow tube is a waveguide used for propagating electromagnetic waves. A general connection structure of a conventional waveguide is one in which a waveguide is connected using a flange provided at the end of the waveguide (see, for example, Patent Document 1). FIG. 21 is a general connection structure of a conventional waveguide. FIG. 21A is a perspective view, and FIG. 21B is a cross-sectional view. Thus, in the conventional connection structure, the flange 20 is provided in the edge part of each waveguide to connect, and the flange 20 is screwed using the volt | bolt 18, the nut 21, and the washer 22. As shown in FIG.

  As a connection structure of a different form, there is a technique of providing a taper at the end of each waveguide to be connected and facilitating the connection work by fitting the tapers together to improve reliability (for example, Patent Document 2). reference.).

JP 63-70702 (page 2-3, FIG. 5) JP-A-62-268201 (Page 2, Fig. 1)

  Each of the above known techniques has problems.

  In a conventional general connection structure such as Patent Document 1 shown in FIGS. 22A and 22B, the flange 20 is provided so as to protrude from the waveguide in order to connect the waveguide. The flange 20 needs to be tightened uniformly in order to suppress the leakage of radio waves at the connecting portion and improve the VSWR (Voltage Standing Wave Ratio). It is also necessary to match the centers of the two waveguides to be connected exactly.

  However, for example, when a housing containing a radio is connected to an antenna using a waveguide, it may be forced to be screwed at a location far from the flange for convenience of design. In such a case, it is difficult to tighten the flange uniformly.

  Furthermore, the optimum flange size depends on the frequency of the radio wave propagating through the inside of the waveguide, and cannot be minimized as long as it can be screwed. As described above, the restriction on the size of the flange is an obstacle to design in reducing the size of the radio.

  The connection structure of Patent Document 2 facilitates connection using a taper and improves reliability, but it is described that “a slight gap may occur when the taper portion is fitted”. As shown, the contact of the tapered portion is not reliable. For example, problems arise when connecting rectangular waveguides. In general, there is an error in the dimensions of each part of the waveguide including the tapered part. When connecting the waveguides, a slight dimensional error is allowed by providing a taper at the connecting portion, but the allowable range of the vertical / horizontal dimensional ratio error of the cross section of the rectangular waveguide is narrow. In other words, if there is an error in the vertical / horizontal dimension ratio of the tapered portion, the contact pressure (hereinafter referred to as pressure contact force) of the vertical surface of the taper portion and the pressure contact force of the horizontal surface when the waveguide is connected are completely. Does not match, and one is always larger and the other is smaller. Therefore, the contact of the surface of the taper portion with the smaller pressure contact force becomes incomplete, and perfect airtightness cannot be obtained, causing the above-described problems. The term “airtight” as used herein means an electromagnetic wave that flows through the inside of the waveguide, and means that the contact surface is in full electrical contact and is electrically sealed over the entire circumference of the hollow tube. .

  In the connection structure of Patent Document 2, a gap is filled with a conductive gasket in order to complete electrical contact. A general conductive gasket covers the periphery of the base material of the gasket with a conductive material, and has a more complicated structure than a normal insulating gasket made of only an elastic resin such as synthetic rubber. Therefore, in general, the conductive gasket is more expensive than a normal insulating gasket. Thus, the connection structure of Patent Document 2 has a problem that an expensive gasket must be used in order to prevent a problem due to incomplete contact of the tapered portion.

As described above, since the airtightness of the connection part of the hollow tube is incomplete in the conventional technology, for example, in the case of the waveguide, there is a problem that radio waves leak from the connection part or the VSWR deteriorates. is there. And in order to ensure electrical sealing, there exists a problem that an expensive gasket must be used.
(Object of invention)
The present invention has been made in view of the technical problems as described above, and when connecting the hollow tube, it is possible to complete the airtightness of the connecting portion without using a special member. It aims at providing a hollow tube, a hollow tube connection structure, and a hollow tube connection method.

  The hollow tube connection structure of the present invention is a hollow tube connection structure that connects the first end of the first hollow tube and the second end of the second hollow tube, The hollow tube has a convex taper portion whose outer diameter increases from the first end toward the other end, and the second hollow tube has an inner diameter from the second end toward the other end. An outer periphery of a cross-section cut by a plane perpendicular to a predetermined first central axis passing through the hollow portion of the convex taper portion The inner periphery of the cross section obtained by cutting the concave taper portion along a plane perpendicular to the predetermined second central axis passing through the hollow portion of the concave taper portion includes a curve.

  The first hollow tube and the second hollow tube may include a conductive material. The first hollow tube and the second hollow tube may be elliptical waveguides or rectangular waveguides.

  Furthermore, in the hollow tube connection structure of the present invention, when the convex taper portion and the concave taper portion are fitted, the first central axis and the second central axis coincide, and the convex taper portion and the concave taper portion are A taper angle that is an angle formed between the first central axis and the second central axis may be constant.

  The hollow tube connection structure of the present invention may include an annular sealing member made of an elastic material. The first hollow tube includes a first side surface in contact with the sealing member parallel to the first central axis, and the second hollow tube is sealed in parallel to the second central axis. You may provide the 2nd side surface which contacts a stop member.

  In the hollow tube, the hollow tube connecting structure and the hollow tube connecting method of the present invention, a tapered portion including a curved portion is provided in a part of the cross section at an end portion where the hollow tube is connected, and the tapered portions are connected to each other. The hollow tube is connected by fitting. Therefore, there is an effect that the airtightness of the connecting portion when connecting the hollow tubes can be made complete.

  Next, the best mode for carrying out the present invention will be described in detail with reference to the drawings. In this best mode, a waveguide is used as an example of a hollow tube. FIG. 1 is a perspective view of a waveguide according to the best mode of the present invention. FIG. 2 is a side view of the waveguide of the best mode of the present invention, FIG. 2 (a) is a side view seen from a direction perpendicular to the central axis, and FIG. 2 (b) is the inside of the waveguide from the end. FIG. FIG. 3 is a perspective view of the waveguide connection structure of the best mode. FIG. 4 is a side view of the waveguide connection structure of the best mode of the present invention. FIG. 5 is a cross-sectional view of the waveguide connection structure of FIG. 4 taken along A-A ′.

  The structures of the waveguides in this embodiment and the following examples are the same as those conventionally used except for the tapered portion, and are well known to those skilled in the art. The structure of the waveguide is not directly related to the gist of the present invention except for the tapered portion. Therefore, a general description of the waveguide itself is omitted. In addition, the inner diameters of the hollow portions of the two waveguides connected in the best mode and the following embodiments are all equal.

  First, the structures of the first waveguide 1 and the second waveguide 2 in the best mode will be described with reference to FIGS. The first waveguide 1 and the second waveguide 2 each include a convex taper portion 3 and a concave taper portion 4. The “tapered portion” in the present invention refers to a surface that is inclined with respect to a predetermined reference line or reference surface. By fitting the convex taper portion 3 and the concave taper portion 4, the first waveguide 1 and the second waveguide 2 are connected.

  The convex taper portion 3 and the concave taper portion 4 have a constant angle θ (hereinafter referred to as a taper angle) with respect to the central axis 5 for the first waveguide 1 and the central axis 6 for the second waveguide 2. Make it. Therefore, the convex taper portion 3 and the concave taper portion 4 are part of the side surface of the cone having an apex angle of 2θ, and are the front and back surfaces of the same shape. The taper angle θ can be arbitrarily set between 0 and 90 °.

  Next, the waveguide connection structure of the best mode will be described with reference to FIGS. 3, 4, and 5. Since the convex taper portion 3 and the concave taper portion 4 are the front and back surfaces of the same shape, the first waveguide 1 and the second waveguide 2 indicated by arrows in FIGS. 3 and 4 are pressed against each other. When the forces f1 and f2 are applied, the first waveguide 1 and the second waveguide 2 are connected. At this time, as shown in FIG. 5, the convex taper portion 3 and the concave taper portion 4 are in close contact with each other. However, strictly speaking, there is an error in the dimensions of the convex taper portion 3 and the concave taper portion 4, so that they do not adhere unless f1 and f2 are sufficiently large. The mechanism by which the convex taper part 3 and the concave taper part 4 adhere will be described later.

  The method for generating f1 and f2 is not particularly limited. The method for generating f1 and f2 includes, for example, tightening with bolts, which will be described in the fourth embodiment.

  Since the first waveguide 1 and the second waveguide 2 are each provided with a convex taper portion 3 and a concave taper portion 4 for connection, the pressure contact force is less than when a normal flange is used. Electrical contact can be made. This is because the convex taper portion is pushed into the concave taper portion 4 like a “wedge”.

  In the present embodiment, the taper angle θ is constant for all side surfaces of the convex taper portion 3 and the concave taper portion 4. Therefore, the pressure contact force when fitted is constant on all side surfaces of the convex taper portion 3 and the concave taper portion 4, and uniform contact can be obtained.

  Further, when the taper angle θ is constant, a self-alignment effect occurs when the convex taper portion and the concave taper portion 4 are pressed against each other. Therefore, a force is applied so that the central axis 5 of the first waveguide 1 and the central axis 6 of the second waveguide 2 coincide with each other, and accurate fitting with the central axes coincident can be performed.

  In the conventional waveguide connection structure using a flange, the pressure contact force is increased by using a large number of bolts, and by adjusting the tightening force of the bolts, the incomplete contact due to the unevenness of the plane is made uniform and electrical contact is achieved. Secured. However, in the present invention, by using the taper, the electrical contact is ensured by utilizing the effect of increasing the pressing force and the self-alignment effect.

  By the way, since the manufacturing accuracy of the first waveguide 1 and the second waveguide 2 is limited, there is an error in the dimensions and taper angle θ of the convex taper portion 3 and the concave taper portion 4. Therefore, the shapes of the surfaces of the convex taper portion 3 and the concave taper portion 4 that contact each other at the time of fitting are not completely the same. Further, the cross sections of the convex taper portion 3 and the concave taper portion 4 are not perfect circles. Therefore, when f1 and f2 are not sufficiently large when the convex taper portion 3 and the concave taper portion 4 are fitted, the entire surfaces that are in contact with each other are not completely in contact with each other. When the convex taper portion 3 and the concave taper portion 4 are fitted together, there is a gap between the convex taper portion 3 and the concave taper portion 4 at the moment when they contact each other.

  However, when large f1 and f2 are added to make a firm fit, and a sufficient pressure contact force is applied to the convex taper portion 3 and the concave taper portion 4, the convex taper portion 3 and the concave taper portion 4 are connected to the central shaft 5. The central axis 6 moves in the direction of coincidence and further deforms due to the reaction force from the contact surface. And it stops at the position where the gap disappears, and the connection structure in which the convex taper portion 3 and the concave taper portion 4 are seen in the entire periphery and are in electrical contact is completed.

  FIG. 6A shows the first waveguide 1 and the second waveguide 2 when the cross section of the first waveguide 2 is not an exact circle but is deformed to a slightly flat shape (ellipse). FIG. 6B is a side view of the top view when the waveguide 2 is connected. FIG. 7 is a cross-sectional view taken along the line A-A ′ of FIG. 6.

  Thus, when the pressure contact force is small, a gap exists between the outside of the convex taper portion 3 and the inside of the concave taper portion 4 as shown in FIGS. Here, when a pressing force is applied to the first waveguide 1 and the second waveguide 2 as indicated by arrows in FIG. 6B, the outer side of the convex taper portion 3 as shown in FIG. The contact portion of the concave taper portion 4 is pressed. And the convex taper part 3 and the concave taper part 4 deform | transform, and stand still in the state which the circumference | surroundings contacted completely. At this time, when the contact points of the convex taper portion 3 and the concave taper portion 4 are continuous, a closed belt-like contact surface such as a part of the side surface of the cone is cut off is formed.

Here, it is needless to say that the manufacturing accuracy of the convex taper portion 3 and the concave taper portion 4 needs to be within a range where complete electrical contact can be obtained by deformation.
(Effect of the best embodiment)
In the best embodiment, the circular waveguide to be connected is provided with a tapered portion at the connection portion, so that an electrical contact can be performed with a smaller pressure than when a normal flange is used. Further, the circular waveguide to be connected can obtain reliable electrical contact by the taper portion being deformed.

  Since the taper angle θ is constant, the pressure contact force becomes uniform, and reliable electrical contact can be obtained over the entire periphery of the taper portion. Since the taper angle θ is constant, the self-alignment effect of the taper part can be obtained, and a force is applied in the direction in which the centers of the two waveguides to be connected coincide with each other. There is also an effect that it can be performed.

  Thus, since reliable electrical contact is obtained at the connecting portion, problems such as radio wave leakage from the connecting portion and deterioration of VWSR can be prevented.

  Waveguides of various shapes such as circular waveguides, elliptical waveguides, and rectangular waveguides have been put into practical use. Since these waveguides have different characteristics, they are used according to the situation. In the best embodiment, the connection structure when the first waveguide 1 and the second waveguide 2 are circular waveguides has been described. However, the first waveguide 1 and the second waveguide are described. The tube 2 may be an elliptical waveguide.

  8A and 8B are perspective views of the elliptical waveguide according to the first embodiment of the present invention, in which FIG. 9A is a top view, FIG. 9B is a side view as seen from a direction perpendicular to the central axis, and FIG. 9 (c) is a side view of the inside of the waveguide viewed from the end in the direction of the central axis.

  Also in Example 1, the taper angle θ of the convex taper portion 3 and the concave taper portion 4 is constant. Since the taper angle θ is constant and the cross sections of the convex taper portion 3 and the concave taper portion 4 are elliptical, the side surfaces of the convex taper portion 3 and the concave taper portion 4 do not become part of the side surface of the cone.

  The generation of a strong pressing force due to the effect of the taper itself having a wedge-like shape and the self-alignment effect are the same as in the case of the circular waveguide of the best embodiment, and thus the description thereof is omitted.

  Since the taper angle θ is constant, the pressing force applied along the central axis 5 and the central axis 6 and the angles of the surfaces of the convex taper portion 3 and the concave taper portion 4 are constant. Accordingly, the pressing force applied in the direction perpendicular to the convex taper portion 3 and the concave taper portion 4 when fitted is constant. Therefore, constant electrical contact is obtained for the entire periphery of the convex taper portion 3 and the concave taper portion 4.

  Further, even when there is an error in the dimensions and taper angle θ of the convex taper portion 3 and the concave taper portion 4, the convex taper portion 3 and the concave taper portion 4 are deformed by the pressure contact force, so that the pressure contact force is made uniform. Easy to get effect.

In the best mode and the first embodiment, the taper angle θ is constant, thereby obtaining special effects such as uniform pressure contact force and self-alignment effect. However, as long as the convex taper portion 3 and the concave taper portion 4 have a tapered shape that can be fitted to each other, airtightness can be ensured, and the effect of the present invention is exhibited. Therefore, in the present invention, it is not always essential that the taper angle θ is constant.
(Effect of Example 1)
In the first embodiment, by providing the elliptical waveguide to be connected with a tapered portion having a certain taper angle, there is an effect that the pressure contact force at the time of connection is constant and reliable electrical contact can be obtained. For this reason, it is possible to prevent problems such as radio wave leakage from the connecting portion and deterioration of VWSR.

  The waveguide according to the present invention includes the convex taper portion 3 and the concave taper portion 4, and those cross sections only need to include a curve. Therefore, the waveguide of the present invention can be applied to connection of waveguides having shapes other than circular and elliptical shapes. can do. For example, the present invention can also be applied to a rectangular waveguide connection.

  FIG. 10 is a perspective view of a waveguide according to the second embodiment of the present invention. 11A and 11B are side views of the waveguide according to the second embodiment of the present invention. FIG. 11A is a top view of the waveguide, and FIG. 11B is viewed from a direction perpendicular to the central axis. A side view and FIG.11 (c) are the side views which looked at the center axis direction from the edge part.

  The structures of the first waveguide 1 and the second waveguide 2 according to the second embodiment will be described with reference to FIGS. 10 and 11. The first waveguide 1 includes a convex taper portion 3, and the second waveguide 2 includes a concave taper portion 4. By fitting the convex taper portion 3 and the concave taper portion 4, the first waveguide 1 and the second waveguide 2 are connected.

  Unlike the best embodiment and Example 1, the convex taper portion 3 and the concave taper portion 4 are composed of a flat surface portion and a curved surface portion. The convex taper portion 3 includes a flat surface portion 7 and a curved surface portion 8, and the concave taper portion 4 includes a flat surface portion 9 and a curved surface portion 10. The phase part 8 forms a constant taper angle θ with the central axis 11 passing through the point X and parallel to the central axis 5. The curved surface portion 10 forms a constant taper angle θ with a central axis 12 passing through the point Y and parallel to the central axis 6. Accordingly, the surface portion 8 and the curved surface portion 10 are the curved surfaces of a quarter of the side surface of the cone having vertices of X and Y and an apex angle of 2θ, respectively. The taper angle θ can be arbitrarily set between 0 and 90 °. The length L1 of the convex taper portion 3 and the length L2 of the concave taper portion 4 need to satisfy L1> L2 so that the taper portion is completely fitted.

  FIG. 12 is a perspective view of the waveguide connection structure according to the second embodiment of the present invention. 13 is a side view of the waveguide connection structure of the second embodiment of the present invention, FIG. 13 (a) is a top view, FIG. 13 (b) is a side view seen from a direction perpendicular to the central axis, FIG. 13C is a cross-sectional view taken along the line AA ′. As described above, the first tapered waveguide 1 and the second waveguide are formed by fitting the convex tapered portion 3 and the concave tapered portion 4 having the same shape and having a convex shape and a concave shape, respectively. 2 are connected.

  The uniform pressure contact force due to the constant taper angle θ, the generation of strong pressure contact force due to the effect of the taper itself having a wedge-like shape, and the self-alignment effect are the same as in the best embodiment. The detailed explanation is omitted.

  Next, the principle that the convex taper portion 3 and the concave taper portion 4 come into contact with each other will be described.

  14A is a top view when the first waveguide 1 and the second waveguide 2 are connected, and FIG. 14B is a side view. 14A and 14B, the ratio of the height of the cross section of the first waveguide 2 to the length of the base (hereinafter referred to as the aspect ratio) is the cross section of the second waveguide 1. Is larger than the aspect ratio. FIG. 15 is a cross-sectional view taken along the line A-A ′ of FIG. 14.

  As shown in FIGS. 14A and 15, the aspect ratio of the cross section of the first waveguide 2 is larger than the aspect ratio of the cross section of the second waveguide 1. A gap is generated between the outside of the convex taper portion 3 and the inside of the concave taper portion 4. Here, when a force pressing the first waveguide 1 and the second waveguide 2 indicated by arrows f1 and f2 in FIGS. 14A and 14B is applied, a convex shape as shown in FIG. The outside of the die taper portion 3 and the contact portion of the concave taper portion 4 are pressed against each other. And the corner part shown with the circle | round | yen of FIG. 15 of the convex taper part 3 and the concave taper part 4 deform | transforms, and it rests in the state which the circumference | surroundings contacted completely. Then, the contact points between the convex taper portion 3 and the concave taper portion 4 are continuous, so that a closed belt-like surface composed of the flat surface portion 7 and the curved surface portion 8 and a closed belt-shaped surface composed of the flat surface portion 9 and the curved surface portion 10 are formed. A fully contacting contact surface is formed.

  14 and 15 show the dimensional error extremely large, but it is assumed that the dimensional error is equal to or less than the deformation amount of the convex taper portion 3 and the concave taper portion 4.

  In the case of connecting the rectangular waveguides, the effect of deformation of the tapered portion as described above cannot be obtained with a conventional tapered portion including only a flat surface. FIG. 16 shows a cross-sectional view of the connection structure when the rectangular waveguide has a tapered portion consisting only of a plane. In particular, the tapered portion of the rectangular waveguide having only the plane shown in FIG. 16 is unlikely to come into contact with the tapered portion opposed to the corner portion indicated by a circle. Because the taper part has a shape where the planes are joined at right angles, the corner part has a very high curvature, and when there is a dimensional error in the taper part, the corner part does not deform flexibly so as to be in close contact with the opposing taper part. Because.

Note that the first waveguide 1 and the second waveguide 2 in this embodiment are general rectangular waveguides in which each side of the cross section is a straight line. Needless to say, the length ratio is not particularly limited.
(Effect of Example 2)
As described above, according to the present embodiment, the rectangular waveguide includes the taper portion, and a part of the cross section of the taper portion is curved, so that the taper portions of the two rectangular waveguides to be connected are connected. It is possible to absorb the error of the dimension and to obtain a reliable contact. For this reason, it is possible to prevent problems such as radio wave leakage from the connecting portion and deterioration of VWSR.

  Antennas and radios are often used outdoors. In order to prepare for use outdoors, the waveguide connection structure according to the third embodiment of the present invention includes a gasket in the fitting portion of the waveguide. FIG. 17 is a cross-sectional view of the waveguide of the third embodiment of the present invention cut along a plane including the central axis of the waveguide. 18A is a side view when the first waveguide 1 and the second waveguide 2 are connected, and FIG. 18B is a cross-sectional view taken along line AA ′ in FIG. FIG.

  As shown in FIG. 17, the first waveguide 1 includes an annular groove 14 for holding the gasket 13. The second waveguide 2 includes an inner wall portion 15 for contacting the gasket. The outer diameter of the first waveguide 1 is thinner than the inner diameter of the inner wall portion 15. Further, the outer diameter of the gasket 13 is slightly larger than the inner diameter of the inner wall portion 15. By appropriately setting the diameter of each part in this way, the gasket 13 is sandwiched between the annular groove 14 and the inner wall 15 when the first waveguide 1 and the second waveguide 2 are connected. , Undergo moderate compression. That is, when the first waveguide 1 and the second waveguide 2 are connected, the gasket 13 is connected to the first waveguide 1 and the second waveguide as shown in FIGS. Between the two waveguides 2. Thereby, the gasket 13 reinforces airtightness in addition to the effect of preventing leakage of electromagnetic waves due to contact between the convex taper portion 3 and the concave taper portion 4, and exhibits a waterproof effect.

  For the gasket 13, an insulator such as synthetic rubber is usually used. For this reason, it is desirable to mount at a position that does not affect electrical contact. In the third embodiment, the gasket 13 is brought into contact with the annular groove 14 and the inner wall portion 15 that are not in contact with the tapered portion whose main purpose is electrical contact, so that the electrical contact is not affected. ing.

In the third embodiment, the waveguide is a circular waveguide. However, by using a gasket that can be applied to the cross-sectional shape of the waveguide, it is possible to cope with waveguides of other shapes.
(Effect of Example 3)
As described above, the waveguide connection structure according to the third embodiment includes the tapered portion and the elastic and insulating gasket in the waveguide. For this reason, in addition to the effect of reliable electrical contact by the tapered portion, the airtightness of the connecting portion can be ensured, thus providing a waterproof effect. Therefore, the apparatus using this waveguide connection structure has an effect that it can be used outdoors.

  19 and 20 are diagrams showing a method of connecting a radio device having a waveguide connection structure and a parabolic antenna according to a fourth embodiment of the present invention, FIG. 19 is a side view, and FIG. 20 is a perspective view. is there.

  The wireless device 16 includes a first waveguide 1 having a convex taper portion 3. The antenna 17 includes a second waveguide 2 having a concave taper portion 4. And when connecting the radio | wireless machine 16 and the antenna 17, the 1st waveguide 1 and the 2nd waveguide 2 are fitted, and it is for fastening in the edge part of the radio | wireless machine 16, and the edge part of the antenna 17. The hole 18 is fixed with a bolt 19.

  At this time, the first waveguide 1 and the second waveguide 2 are ensured to be in electrical contact by the effect of the convex taper portion 3 and the concave taper portion 4. Further, since the first waveguide 1 is provided with the gasket 13, the connection portion between the first waveguide 1 and the second waveguide 2 is waterproof. Therefore, the radio device 16 and the antenna 17 can be connected to support outdoor use.

Needless to say, the waveguide used in the fourth embodiment is not limited to a circular waveguide, but may be an elliptical or rectangular waveguide.
(Effect of Example 4)
In the waveguide connection method according to the fourth embodiment, the connection of the waveguide is performed at the same time by fixing the wireless device to the antenna using a bolt. Therefore, there is an effect that it is easy to replace the wireless device for maintenance. In addition, since the structure is simple and there are no complicated mechanical parts, there is an effect that a highly reliable wireless system can be configured with few failures. Moreover, since the gasket is provided at the connection portion of the waveguide, it can be used outdoors.

It is a perspective view of the waveguide of the best form of this invention. It is a side view of the waveguide of the best form of this invention. It is a perspective view of the waveguide connection structure of the best form of this invention. It is a side view of the waveguide connection structure of the best form of this invention. It is sectional drawing of the waveguide connection structure of the best form of this invention. It is a side view of the connection structure of the deformed circular waveguide. It is sectional drawing of the connection structure of the deformed circular waveguide. It is a perspective view of the elliptical waveguide of the 1st example of the present invention. It is the upper side figure and side view of the elliptical waveguide of 1st Example of this invention. It is a perspective view of the waveguide of the 2nd example of the present invention. It is the top view and side view of a waveguide of the 2nd example of the present invention. It is a perspective view of the waveguide connection structure of the 2nd Example of this invention. It is the top view, side view, and sectional drawing of the waveguide connection structure of 2nd Example of this invention. It is the top view and side view of the connection structure of the waveguide with a dimension error of 2nd Example of this invention. It is sectional drawing of the connection structure of the waveguide with a dimension error of 2nd Example of this invention. It is sectional drawing of the connection structure of the waveguide which is provided with the taper part which consists of only a plane of 2nd Example of this invention, and has a dimensional error. It is sectional drawing which cut | disconnected the connection part of the waveguide connection structure of the best form of this invention by the plane perpendicular | vertical to the central axis of a waveguide. It is the side view and sectional drawing of the waveguide connection structure of the 3rd Example of this invention. It is a side view which shows the connection method of a radio | wireless machine and a parabolic antenna provided with the waveguide connection structure of the 4th Example of this invention. It is a perspective view which shows the connection method of a radio | wireless machine and a parabolic antenna provided with the waveguide connection structure of the 4th Example of this invention. It is the perspective view and sectional drawing of the conventional waveguide connection structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st waveguide 2 2nd waveguide 3 Convex taper part 4 Concave taper part 5 1st center axis 6 2nd center axis 7, 9 Plane part 8, 10 Curved surface part 11, 12 Center axis 13 Gasket 14 Annular Groove 15 Inner Wall 16 Radio 17 Antenna 18 Hole 19 Bolt 20 Flange 21 Nut 22 Washer

Claims (21)

A hollow tube connection structure for connecting a first end of a first hollow tube and a second end of a second hollow tube,
The first hollow tube includes a convex taper portion whose outer diameter increases from the first end portion toward the other end portion,
The second hollow tube has a concave taper portion whose inner diameter decreases from the second end portion toward the other end portion, and fits with the convex taper portion,
An outer periphery of a cross section obtained by cutting the convex taper portion by a plane perpendicular to a predetermined first central axis that penetrates the hollow portion of the convex taper portion, and the concave taper portion penetrates the hollow portion of the concave taper portion A hollow tube connecting structure, wherein an inner periphery of a cross section cut by a plane perpendicular to a predetermined second central axis includes a curve. The hollow tube connection structure according to claim 1, wherein the first hollow tube and the second hollow tube include a conductive material. The hollow tube connection structure according to claim 2, wherein the first hollow tube and the second hollow tube are elliptical waveguides. The hollow tube connection structure according to claim 2, wherein the first hollow tube and the second hollow tube are rectangular waveguides. When the convex taper portion and the concave taper portion are fitted, the first central axis and the second central axis coincide,
5. The taper angle, which is an angle formed between the convex taper portion and the concave taper portion with the first central axis and the second central axis, is constant. 6. The hollow tube connection structure described in 1. The hollow tube connection structure according to claim 1, further comprising an annular sealing member made of an elastic material. The first hollow tube includes a first side surface that is parallel to the first central axis and that contacts the sealing member;
The hollow tube connection structure according to claim 6, wherein the second hollow tube includes a second side surface that is parallel to the second central axis and is in contact with the sealing member. A hollow tube having a connection portion connectable with another hollow tube,
The connection portion includes a convex taper portion whose outer diameter increases from one end portion toward the other end portion, and is fitted with a predetermined concave taper portion,
A hollow tube characterized in that an outer periphery of a cross section obtained by cutting the convex taper portion along a plane perpendicular to a predetermined center axis passing through the hollow portion of the convex taper portion includes a curve. 9. The hollow tube connection structure according to claim 8, wherein the convex taper portion has a constant taper angle which is an angle formed with the central axis. A hollow tube having a connection portion connectable with another hollow tube,
The connection portion includes a concave taper portion whose inner diameter decreases from one end portion toward the other end portion, and is fitted with a predetermined convex taper portion,
A hollow tube characterized in that an inner periphery of a cross section obtained by cutting the concave taper portion along a plane perpendicular to a predetermined central axis passing through the hollow portion of the concave taper portion includes a curve. The hollow tube connecting structure according to claim 10, wherein the concave taper portion has a constant taper angle that is an angle formed with the central axis. The hollow tube according to any one of claims 8 and 9, wherein the hollow tube can be connected to the hollow tube according to any one of claims 10 and 11. The hollow tube according to any one of claims 10 and 11, which can be connected to the hollow tube according to any one of claims 8 and 9. The hollow tube according to claim 8, wherein the hollow tube is made of a conductive material. The hollow tube according to claim 8, wherein the hollow tube is an elliptical waveguide. The hollow tube according to any one of claims 8 to 14, wherein the hollow tube is a rectangular waveguide. The hollow tube connection structure according to any one of claims 8 to 16, further comprising a side surface that contacts an annular sealing member made of an elastic material. The hollow pipe connection structure according to claim 17, wherein the side surface is parallel to the central axis. A hollow tube connection method for connecting a first end of a first hollow tube and a second end of a second hollow tube,
A convex taper portion whose outer diameter increases from the first end portion toward the other end portion, and is a plane perpendicular to a predetermined first central axis that penetrates the hollow portion of the convex taper portion. A convex taper part whose outer periphery of the cut section includes a curve, and a concave taper part whose inner diameter decreases from the second end part toward the other end part, and penetrates the hollow part of the concave taper part A hollow tube connecting method comprising: fitting a concave taper portion in which an inner periphery of a cross section cut along a plane perpendicular to a predetermined second central axis includes a curved line. The convex taper portion having a constant taper angle, which is an angle formed with the first central axis, and the concave taper portion, the angle formed with the second central axis being equal to the taper angle. The hollow tube connecting method according to claim 19, further comprising a step of fitting so that an axis and the second central axis coincide with each other. And a step of bringing an annular sealing member made of an elastic material into contact with a predetermined first side surface of the first hollow tube and a predetermined second side surface of the second hollow tube. The hollow tube connection method according to any one of claims 19 and 20.

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