Lightning Protection Coaxial Connector

Abstract

To provide a lightning protection coaxial connector in which a capacitor can be interposed between central conductors without the need of soldering.SOLUTION: A lightning protection coaxial connector 10 comprises: first and second cylindrical outer conductors 50, 60 that are connected with a coaxial cable and each have an arrestor element 11 therein; first and second rod-like central conductors 20, 30 that are connected with the coaxial cable and are coaxially arranged; insulators 41-44 that support the first and second central conductors 20, 30; an elastic body 12 that urges at least any one central conductor of the first and second central conductors 20, 30 toward the other central conductor; and a capacitor 13 that is arranged between the first and second central conductors 20, 30 and has first and second electrodes 13a, 13b. The urging force of the elastic body 12 brings the first and second electrodes 13a, 13b of the capacitor 13 into contact with the first and second central conductors 20, 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lightning protection coaxial connector that is connected to a coaxial cable and has an arrester element therein. [Background technology]

[0002] Conventionally, a lightning coaxial connector has been proposed, for example, as described in Patent Document 1. The connector described in Patent Document 1 has a DC component cut-off / injection function that cuts off the transmitted DC component and injects another DC component. In this type of lightning coaxial connector, a circuit wiring that forms a central conductor, etc. is formed on the surface of an insulating substrate by a microstrip line, and an arrester element, a chip capacitor for cutting DC components, etc. are attached to this circuit wiring by soldering. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3079493 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the invention described in Patent Document 1, the capacitor must be soldered to the board, which is time-consuming and has the problem that electrical characteristics such as frequency characteristics vary depending on the soldering skill of the worker.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to provide a lightning protection coaxial connector in which a capacitor is interposed in a central conductor without the need for soldering. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention includes the subject matter described in the following paragraphs.

[0007] Item 1: A lightning-arresting coaxial connector that is connected to a coaxial cable and has an arrester element therein, First and second cylindrical outer conductors; first and second rod-shaped central conductors connected to the coaxial cable and arranged coaxially; an insulator supporting the first and second central conductors within the first and second outer conductors; an elastic body that biases at least one of the first and second central conductors toward the other central conductor; a capacitor disposed between the first and second central conductors, the capacitor having first and second electrodes; At least one of the first and second central conductors is supported by an insulator so as to be movable along an axial direction; A lightning-resistant coaxial connector in which at least one of the first and second central conductors is biased toward the other, causing the first and second electrodes of the capacitor to abut against the first and second central conductors.

[0008] Item 2: A lightning protection coaxial connector according to item 1, wherein the first and second electrodes of the capacitor are located at both ends in the axial direction and include flat surfaces along a plane perpendicular to the axis.

[0009] Item 3: A lightning protection coaxial connector according to item 1 or 2, wherein the capacitor is held within a hollow portion formed in the insulator so as to be freely movable along the axial direction.

[0010] Item 4: A lightning protection coaxial connector according to any one of items 1 to 3, wherein an area of ​​an end face of at least one of the first and second central conductors that abuts against at least one of the first and second electrodes of the capacitor is larger than a cross-sectional area of ​​another portion of at least one of the first and second central conductors.

[0011] Item 5: The elastic body is a spring having a hollow portion, 5. The lightning protection coaxial connector according to any one of items 1 to 4, wherein at least one of the first and second central conductors penetrates the hollow portion. Effect of the Invention

[0012] The present invention allows the capacitor to be connected to the center conductor without soldering. [Brief description of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view taken along the central axis of a lightning protection coaxial connector according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Diagram 3] FIG. 13 is a side view showing the second insulator in an open state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (Overall composition) An embodiment of the present invention will be described with reference to the drawings. A lightning protection coaxial connector 10 of the present invention is connected to a coaxial cable (not shown) and has an arrester element 11 inside. The arrester element 11 instantaneously changes from high resistance to low resistance in response to an overvoltage such as a lightning surge caused by a lightning strike, and flows the surge current to the ground side while suppressing the voltage of the lightning surge. The lightning protection coaxial connector 10 includes cylindrical first and second outer conductors 50, 60, rod-shaped first and second central conductors 20, 30 connected to the central conductor of the coaxial cable and arranged coaxially, first to fourth insulators 41-44 supporting the first and second central conductors 20, 30 inside the first and second outer conductors 60, a coil spring 12 which is an elastic body for biasing at least one of the first and second central conductors 20, 30 toward the other central conductor 30, and a capacitor 13 arranged between the first and second central conductors 20, 30 and having first and second electrodes 13a, 13b. The first and second outer conductors 50, 60, the first and second central conductors 20, 30, and the first to fourth insulators 41-44 are arranged coaxially such that their length directions and axial directions are aligned with the central axis C.

[0015] In the following description, unless otherwise specified, in Fig. 1, the first outer conductor 50 side is referred to as one side or left side, and the second outer conductor 60 side is referred to as the other side or right side along the central axis C of the lightning protection coaxial connector 10. In addition, the cross-sectional shape refers to the shape of a plane perpendicular to the central axis C. The direction along the central axis C is also referred to as the axial direction.

[0016] (First and second outer conductors 50, 60) The first outer conductor 50 has a hollow circular internal cross section, and is provided with a first large diameter section 51, a first medium diameter section 52, a first small diameter section 53, and a first cable insertion section 54, which are successively provided from the right side to the left side. A screw 51a is formed on the inner peripheral surface of the first large diameter section 51, and the screw 51a is screwed into a screw 61a formed on the outer peripheral surface of the second outer conductor 60, thereby connecting the first and second outer conductors 50, 60. A step surface 50a is formed at the left end of the first large diameter section 51 due to the difference in inner diameter with the first medium diameter section 52. The first medium diameter section 52 is formed to have a smaller inner diameter than the first large diameter section 51, and a step surface 50b is formed at the left end of the first medium diameter section 52 due to the difference in inner diameter with the first small diameter section 53. The first medium diameter section 52 houses the first insulator 41. The first small diameter portion 53 is formed to have an inner diameter smaller than that of the first medium diameter portion 52. The first cable insertion portion 54 is formed to have an inner diameter larger than that of the first small diameter portion 53, and the inner diameter becomes larger toward the left side. The material constituting the first outer conductor 50 is, for example, SUS (stainless steel), brass, etc., but is not limited thereto.

[0017] The second outer conductor 60 has a circular cross-sectional shape and is hollow, and from the left side to the right side, a second large diameter portion 61, a second medium diameter portion 62, a second small diameter portion 63, and a second cable insertion portion 64 are continuously formed. The second large diameter portion 61 has a thread 61a formed at the left end of the outer circumferential surface to screw with the second outer conductor 60. The second large diameter portion 61 is set to have a longer axial length than the first large diameter portion 51, and accommodates the second and third insulators 42 and 43. A through hole 61b into which the arrester element 11 is fitted is formed in the peripheral wall of the second large diameter portion 61, and a lid portion 61c is attached to the outer opening of the through hole 61b to close the opening of the through hole 61b with the arrester element 11 fitted therein. A step surface 60a is formed at the right end of the second large diameter portion 61 due to the difference in inner diameter between the second large diameter portion 61 and the second medium diameter portion 62.

[0018] The second medium diameter portion 62 has an inner diameter smaller than that of the second large diameter portion 61, and accommodates the fourth insulator 44. A step surface 60b is formed at the right end of the second medium diameter portion 62 due to the difference in inner diameter with the second small diameter portion 63. The second small diameter portion 63 is formed to have an inner diameter smaller than that of the second medium diameter portion 62. The second cable insertion portion 64 has an inner diameter larger than that of the second small diameter portion 63, and is formed so that the inner diameter increases toward the right side. The material constituting the second outer conductor 60 is, for example, SUS (stainless steel), brass, etc., but is not limited thereto.

[0019] (First and second central conductors 20, 30) (First central conductor 20) The first central conductor 20 is a rod-shaped member located inside the second outer conductor 60 and the first outer conductor 50 along the central axis C. The first central conductor 20 is formed from a known material and processing method. In this embodiment, for example, beryllium copper, phosphor bronze, or the like is used as the material, and the first central conductor 20 is processed into a predetermined shape by cutting. A contact portion 21 having a circular cross-sectional shape and a larger outer diameter than other parts of the first central conductor 20 is formed at the right end of the first central conductor 20. The contact portion 21 is provided to prevent deterioration of the electrical characteristics of the lightning protection coaxial connector 10 caused by interposing the capacitor 13 between the first and second central conductors 20 and 30. The deterioration of the electrical characteristics includes phenomena such as an increase in contact resistance, a fluctuation in specific impedance, and a decrease in voltage standing wave ratio (VSWR) due to an increase in contact resistance or a fluctuation in specific impedance.

[0020] The right end face 21a of the contact portion 21 abuts against the first electrode 13a of the capacitor 13, thereby electrically connecting the first central conductor 20 and the first electrode 13a of the capacitor 13. The outer diameter of the contact portion 21 is preferably set as large as possible, and is equal to or smaller than the inner diameter of the second large diameter portion 61 of the second outer conductor 60, from the viewpoint of reducing the contact resistance with the capacitor 13. The outer diameter of the contact portion 21 is set to a diameter such that the area of ​​the end face 21a of the contact portion 21 abutting against the first electrode 13a of the capacitor 13 is at least larger than the area of ​​the first electrode 13a of the capacitor 13, and the contact portion 21 can contact the entire surface of the first electrode 13a. The axial length of the contact portion 21 (hereinafter, simply referred to as "length") is set to a predetermined length from the viewpoint of maintaining a predetermined specific pin impedance (for example, 50Ω) of the lightning protection coaxial connector 10 and preventing a decrease in the voltage standing wave ratio (VSWR).

[0021] The outer diameter of the contact portion 21 may be set from the following viewpoint. If the capacitor 13 is interposed between the first and second central conductors 20 and 30 without providing the contact portion 21, the characteristic impedance of the capacitor 13 and the third insulator 43 holding the capacitor 13 will be high. This is because the outer diameter of the equivalent central conductor of the capacitor 13 and the third insulator 43 holding the capacitor 13 will be small. For this reason, the contact portion 21 having a large outer diameter is provided to provide low impedance, and the characteristic impedance of the lightning protection coaxial connector 10 as a whole is adjusted to a predetermined value. When the characteristic impedance of the lightning protection coaxial connector 10 is 50Ω, the ratio of the outer diameter of the contact portion 21 to the inner diameter of the second large diameter portion 61 of the second outer conductor 60 (the outer diameter of the third insulator 43) is preferably 1:1.5 or more and 1:2.33 or less. In this embodiment, the outer diameter of the contact portion 21 is 8 mm, the inner diameter of the second large diameter portion 61 of the second outer conductor 60 is 14 mm, and the ratio is 1:1.75.

[0022] On the left side of the contact portion 21 of the first central conductor 20, a first portion 22, a second portion 23 having an outer diameter larger than that of the first portion 22, a third portion 24 having an outer diameter smaller than that of the first portion 22, a fourth portion 25 having the same outer diameter as that of the second portion 23, and a fifth portion 26 having the same outer diameter as that of the first portion 22 are continuously formed. In addition, flat notched surfaces 23a, 25a are formed in parts of the second portion 23 and the fourth portion 25 adjacent to the third portion 24, so that the electrodes of the arrester element 11 come into contact with the first central conductor 20. A slit 27 is provided at the tip of the fifth portion 26 for connection to the central conductor (not shown) of a coaxial cable.

[0023] With the first and second outer conductors 50, 60 fitted together, the entire first portion 22 and the right side of the second portion 23 are held by the second insulator 42, and the right side of the fifth portion 26 is held by the first insulator 41. As a result, the first to fourth portions 22 to 25 extend within the second large diameter portion 61 of the second outer conductor 60, and the fifth portion 26 extends within the first medium diameter portion 52, the first small diameter portion 53 and the first cable insertion portion 54 of the first outer conductor 50. The slit 27 of the fifth portion 26 is located within the first cable insertion portion 54.

[0024] (Second central conductor 30) The second central conductor 30 is a rod-shaped member located along the central axis C in the second outer conductor 60. The second central conductor 30 is formed from a known material and processing method. In this embodiment, for example, beryllium copper or phosphor bronze brass is used as the material, and the second central conductor 30 is processed into a predetermined shape by cutting. The second central conductor 30 includes a left portion 31, a central portion 32 having an outer diameter larger than that of the left portion 31, and a right portion 33 having an outer diameter equal to that of the left portion 31. The left end face 31a of the left portion 31 abuts against the second electrode 13b of the capacitor 13. The area of ​​the left end face 31a is set to be equal to or smaller than the area of ​​the second electrode 13b of the capacitor 13. A slit 34 is provided at the tip of the right portion 33 for connection to a central conductor (not shown) of a coaxial cable.

[0025] With the first and second outer conductors 50, 60 fitted together, the left portion 31 is held by the third insulator 43 and extends into the second large diameter portion 61 of the second outer conductor 60. The central portion 32 extends into the second medium diameter portion 62 of the second outer conductor 60, and the right portion 33 is held by the fourth insulator 44 and extends into the second medium diameter portion 62, the second small diameter portion 63 and the second cable insertion portion 64 of the second outer conductor 60. The slit 34 of the right portion 33 is located in the second cable insertion portion 64.

[0026] (Capacitor 13) The capacitor 13 blocks the flow of DC current generated when the arrester element 11 becomes low resistance due to a lightning surge from flowing to the second central conductor 30. The capacitor 13 is supported by the third insulator 43, and in this embodiment, has a substantially rectangular parallelepiped shape. The first and second electrodes 13a, 13b of the capacitor 13 are located at both ends in the axial direction and are flat surfaces parallel to each other along a plane perpendicular to the axial direction. In this embodiment, the capacitor 13 is a ceramic chip capacitor, but is not limited thereto, and may have a shape that allows the first and second electrodes 13a, 13b to abut against the first and second central conductors 20, 30. For example, the capacitor 13 may be a general leadless capacitor for mounting on a printed circuit board, such as a surface-mount laminated capacitor, having parallel electrodes at both ends, or a feedthrough capacitor.

[0027] (First to fourth insulators 41 to 44) (First insulator 41) Each of the first to fourth insulators 41 to 44 has a cylindrical shape and has a hollow portion with a circular cross section inside. Each of the first to fourth insulators 41 to 44 is made of a resin material such as PTFE (polytetrafluoroethylene), but ceramics may also be used.

[0028] The inner diameter of the hollow portion 41a of the first insulator 41 is approximately the same as the outer diameter of the fifth portion 26 of the first central conductor 20, and is set to a size that allows the fifth portion 26 to be inserted. A ring-shaped protrusion 41c is formed around the hollow portion 41a of the right end face 41b of the first insulator 41, and the protrusion 41c abuts against a step surface 20a caused by the difference in outer diameter between the fifth portion 26 and the fourth portion 25 of the first central conductor 20. The outer diameter of the first insulator 41 is approximately the same as the inner diameter of the first medium diameter portion 52 of the first outer conductor 50. The length of the first insulator 41 excluding the protrusion 41c is equal to the length of the first medium diameter portion 52. The first insulator 41 is held in the first medium diameter portion 52 of the first outer conductor 50 by a frictional force generated between the inner surface of the first medium diameter portion 52 and the outer circumferential surface of the first insulator 41. When a biasing force from the coil spring 12 is applied to the first insulator 41 and the first central conductor 20, the left end face 41d of the first insulator 41 abuts against the step surface 50b of the first medium diameter portion 52, thereby restricting the movement of the first insulator 41 and the first central conductor 20.

[0029] (Second insulator 42) The hollow portion of the second insulator 42 includes a first hollow portion 42a and a second hollow portion 42b that is coaxial with the first hollow portion 42a, is located to the right of the first hollow portion 42a, and has an inner diameter smaller than that of the first hollow portion 42a. The inner diameter of the first hollow portion 42a is approximately the same as the outer diameter of the second portion 23 of the first central conductor 20, and the right portion of the second portion 23 is supported in the first hollow portion 42a. The inner diameter of the second hollow portion 42b is approximately the same as the outer diameter of the first portion 22 of the first central conductor 20, and the length of the second hollow portion 42b is approximately the same as the length of the first portion 22, and the first portion 22 is supported in the second hollow portion 42b. The outer diameter of the second insulator 42 is approximately the same as the inner diameter of the second large diameter portion 61 of the second outer conductor 60, and the second insulator 42 is held at an axial intermediate position of the second large diameter portion 61 by frictional force generated between the inner surface of the second large diameter portion 61 of the second outer conductor 60 and the outer circumferential surface of the second insulator 42. A through hole 42d is formed beside the first hollow portion 42a and the second hollow portion 42b.

[0030] The second insulator 42 is composed of a pair of half-split bodies 42A and 42B, which are obtained by dividing a cylindrical member having a first hollow portion 42a and a second hollow portion 42b formed therein along a plane including a central axis C and the central axis of a through hole 42d along the axial direction. As shown in FIG. 3, the ends of the outer peripheral surfaces of the half-split bodies 42A and 42B are connected to each other via a hinge 42c along the axial direction so as to be freely opened and closed. The half-split body 42A has a columnar shape with a semicircular cross section, and grooves 42g and 42h with semicircular cross sections are formed along the axial direction at the center of a surface 42f facing the half-split body 42B. In addition, a groove 42i with a semicircular cross section is formed between the hinge 42c and the grooves 42g and 42h. The half-split body 42B has a symmetrical shape to the half-split body 42A, and corresponding components are assigned corresponding symbols and will not be described. When the pair of half bodies 42A, 42B are closed and the opposing surfaces 42f, 42f are brought together, the grooves 42g, 42g form the first hollow portion 42a, the grooves 42h, 42h form the second hollow portion 42b, and the grooves 42i, 42i form the through hole 42d. In FIG. 3, the half bodies 42A, 42B are shown slightly open. By opening and closing the half bodies 42A, 42B of the second insulator 42, the first portion 22 and the second portion 23 of the first central conductor 20 can be disposed in the first hollow portion 42a and the second hollow portion 42b, respectively.

[0031] (Third insulator 43) The hollow portion of the third insulator 43 includes a first hollow portion 43a and a second hollow portion 43b on the right side of the first hollow portion 43a, the second hollow portion 43b having a smaller inner diameter than the first hollow portion 43a. The first hollow portion 43a supports the capacitor 13. As shown in FIG. 2, the inner diameter of the first hollow portion 43a is approximately the same as the length of the diagonal of the rectangular capacitor 13 in cross section. The four corners 13c of the capacitor 13 abut against the inner surface of the first hollow portion 43a, and the capacitor 13 is held in the first hollow portion 43a so as to be freely movable in the axial direction due to the frictional force between the inner surface and the corners 13c of the capacitor 13. The capacitor 13 is inserted from the opening on the left side of the first hollow portion 43a, and the insertion is restricted by the second electrode 13b of the capacitor 13 abutting against a step surface 43c generated by the difference in inner diameter between the first hollow portion 43a and the second hollow portion 43b. The length of the first hollow portion 43a is slightly shorter than the length of the capacitor 13, and when the capacitor 13 is fitted into the first hollow portion 43a, the first electrode 13a of the capacitor 13 protrudes to the left from the left end face 43d of the third insulator 43.

[0032] The inner diameter of the second hollow portion 43b is approximately the same as the outer diameter of the left portion 31 of the second central conductor 30, and the left portion 31 of the second central conductor 30 is supported in the second hollow portion 43b so as to be freely movable in the axial direction. The second central conductor 30 is urged toward the first central conductor 20 by the urging force of the coil spring 12, so that the left end face 31a of the left portion 31 abuts against the second electrode 13b of the capacitor 13, and thus the second electrode 13b of the capacitor 13 and the second central conductor 30 are electrically connected. The length of the second hollow portion 43b is set to be slightly shorter than the length of the left portion 31. As a result, the second central conductor 30 can move leftward until the step surface 30a generated by the difference in outer diameter between the left portion 31 and the central portion 32 of the second central conductor 30 abuts against the right end face 43e of the third insulator 43.

[0033] The outer diameter of the third insulator 43 is approximately the same as the inner diameter of the second large diameter portion 61 of the second outer conductor 60, and the third insulator 43 is held to the right of the second large diameter portion 61 by frictional force generated between the inner surface of the second large diameter portion 61 of the second outer conductor 60 and the outer circumferential surface of the second insulator 42. The third insulator 43 is positioned such that there is a small gap S between its right end face 43e and the step surface 60a of the second large diameter portion 61. The right end face 43e of the third insulator 43 may abut against the step surface 60a.

[0034] (fourth insulator 44) The hollow portion of the fourth insulator 44 includes a first hollow portion 44a and a second hollow portion 44b on the right side of the first hollow portion 44a, the second hollow portion 44b having a smaller inner diameter than the first hollow portion 44a. The first hollow portion 44a accommodates the coil spring 12 constituting an elastic body. The coil spring 12 has a hollow portion, and the right portion 33 of the second central conductor 30 penetrates the hollow portion. An O-ring 14 is disposed on the right end side of the coil spring 12. The right end of the coil spring 12 abuts against a step surface 44d generated by the difference in inner diameter between the first hollow portion 44a and the second hollow portion 44b via the O-ring 14, and the left end of the coil spring 12 abuts against a step surface 30b generated by the difference in diameter between the central portion 32 and the right portion 33 of the second central conductor 30, thereby applying a force to the second central conductor 30 in the left direction. The length of the first hollow portion 44a is set to be slightly shorter than the total length of the coil spring 12 when it is most compressed and the thickness of the O-ring 14.

[0035] The second hollow portion 44b has an inner diameter substantially the same as the outer diameter of the right portion 33 of the second central conductor 30, and supports the right portion 33 of the second central conductor 30 so as to be movable along the central axis C.

[0036] The outer diameter of the fourth insulator 44 is approximately the same as the inner diameter of the second medium diameter portion 62 of the second outer conductor 60, and the fourth insulator 44 is held in the second medium diameter portion 62 by frictional force generated between the inner surface of the second medium diameter portion 62 of the second outer conductor 60 and the outer circumferential surface of the fourth insulator 44. The fourth insulator 44 is disposed such that a right end surface 44c of the fourth insulator 44 abuts against the step surface 60b of the second medium diameter portion 62.

[0037] (Assembly procedure) The assembly procedure of the lightning protection coaxial cable will be described. First, the first insulator 41 and the second insulator 42 are attached to the first central conductor 20. Next, the capacitor 13 is fitted into the first hollow portion 43a of the third insulator 43, and the left portion 31 of the second central conductor 30 is inserted into the second hollow portion 43b. Then, the coil spring 12 and the O-ring 14 are inserted into the right portion 33 of the second central conductor 30, and the fourth insulator 44 is inserted from the first hollow portion 44a to position the coil spring 12 and the O-ring 14 in the first hollow portion 44a. The coil spring 12 is positioned between the step surface 30b generated by the difference in outer diameter between the central portion 32 and the right portion 33 and the O-ring 14.

[0038] The first central conductor 20 having the first insulator 41 and the second insulator 42 attached thereto is inserted into the first outer conductor 50 until the first insulator 41 abuts against the stepped surface 50b of the first medium diameter portion 52 of the first outer conductor 50. The second central conductor 30 having the third insulator 43 and the fourth insulator 44 attached thereto is inserted into the second outer conductor 60 until the fourth insulator 44 abuts against the stepped surface 60b of the second medium diameter portion 62 of the second outer conductor 60.

[0039] Then, the threads 51a on the inner circumferential surface of the first outer conductor 50 and the threads 61a on the outer circumferential surface of the second outer conductor 60 are screwed together to connect the first outer conductor 50 and the second outer conductor 60. As the first and second outer conductors 50, 60 are fitted together, the coil spring 12 presses the second central conductor 30 rightward. As a result, the contact portion 21 of the first central conductor 20 abuts against the first electrode 13a of the capacitor 13, and the left portion 31 of the second central conductor 30 abuts against the second electrode 13b of the capacitor 13, electrically connecting the capacitor 13 to the first and second central conductors 20, 30.

[0040] The arrester element 11 is fitted into the through hole 61b of the second outer conductor 60, and the opening is covered with a lid portion 61c. The arrester element 11 abuts against the cutout surfaces 23a and 25a of the first central conductor 20 and is electrically connected to the first central conductor 20.

[0041] According to this embodiment, the lightning protection coaxial cable 10 is assembled by accommodating the capacitor 13 supported by the first to fourth insulators 41 to 44 and the first and second central conductors 20 and 30 inside the first outer conductor 50 and the second outer conductor 60, and fitting the first outer conductor 50 and the second outer conductor 60 together. The capacitor 13 can be interposed between the first central conductor 20 and the second central conductor 30 and electrically connected by such a simple operation, eliminating the need for soldering and facilitating assembly. In addition, there is no variation in electrical characteristics due to the soldering skill of the worker. Furthermore, the time required for soldering is no longer required, and a board for mounting the capacitor 13 is no longer required, thereby reducing costs.

[0042] In addition, the second central conductor 30 is biased toward the first central conductor 20 by the coil spring 12, which is an elastic body, and the capacitor 13 is interposed between the first central conductor 20 and the second central conductor 30. Therefore, the first and second electrodes 13a, 13b of the capacitor 13 can be reliably brought into contact with the first and second central conductors 20, 30, respectively, and electrical connection between the first electrode of the capacitor 13 and the first and second central conductors 20, 30 is maintained.

[0043] In this embodiment, a ceramic chip capacitor is used as the capacitor 13. Since ceramic chip capacitors are available in a wide variety of capacitances on the market, a capacitor 13 with an appropriate capacitance can be selected to maintain the electrical characteristics of the lightning protection coaxial connector 10.

[0044] The end face 21a of the contact portion 21 that abuts the first electrode 13a of the capacitor 13 is set to be larger than the area of ​​the first electrode 13a of the capacitor 13 and larger than the cross-sectional area of ​​other parts of the first central conductor 20, thereby making it possible to minimize the contact resistance with the capacitor 13 and to prevent a deterioration in the electrical characteristics.

[0045] Furthermore, by setting the length of the contact portion 21 along the central axis C to a predetermined length, the voltage standing wave ratio (VSWR) of the lightning protection coaxial connector 10 does not decrease, and deterioration of the electrical characteristics can be prevented.

[0046] Furthermore, by passing the second central conductor 30 through the hollow portion of the coil spring 12, the inductance is smaller than when the second central conductor 30 and the coil spring 12 are arranged in succession, and deterioration of the electrical characteristics can be prevented.

[0047] In this embodiment, the O-ring 14 is disposed so as to come into contact with the stepped surface 44d of the first hollow portion 44a of the fourth insulator 44, and the coil spring 12 itself is pressed toward the capacitor 13. Therefore, even when the second central conductor 30 is pulled in a direction away from the capacitor 13 and the coil spring 12 is in the most compressed state, the second central conductor can be reliably brought into contact with the second electrode 13b of the capacitor 13.

[0048] The lightning coaxial connector 10 of this embodiment is lighter than the conventional technology that includes a substrate on which a capacitor 13 and the like are attached. Therefore, when connecting the lightning coaxial connector 10 to a coaxial cable, it can be aerial without being fixed to a frame or the like. In particular, by providing the lightning coaxial connector 10 with a waterproof structure, it can be connected to an aerial coaxial cable outdoors.

[0049] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. In this embodiment, the second central conductor 30 penetrates the hollow part of the coil spring 12, which is an elastic body, and the second central conductor 30 is biased toward the first central conductor 20, but the first central conductor 20 may penetrate the hollow part of the coil spring 12 and bias the first central conductor 20 toward the second central conductor 30. Also, the coil springs 12 may be provided in both the first central conductor 20 and the second central conductor 30, and biased toward each other.

[0050] In addition, in this embodiment, the contact portion 21 is formed in the first central conductor 20, but the contact portion 21 may be formed in the second central conductor 30, or may be provided in both the first central conductor 20 and the second central conductor 30.

[0051] The dimensions, materials, shapes, and relative arrangements of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention. For example, expressions expressing relative or absolute arrangements, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such arrangements, but also express a state in which they are relatively displaced with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions expressing that things are in an equal state, such as "same," "equal," and "homogeneous," not only strictly express a state in which they are equal, but also express a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions expressing shapes such as a square shape or a cylindrical shape not only express shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also express shapes including uneven parts, chamfered parts, etc., to the extent that the same effect is obtained. The expressions "comprise," "include," "include," "include," or "have" one component are not exclusive expressions that exclude the existence of other components. In this specification, expressions accompanied by "approximately" such as "almost the same" may be used. For example, "almost the same" means that it is substantially the same, and includes not only the strictly same state but also an error of a few degrees. The same applies to other expressions accompanied by "approximately". Furthermore, in this specification, expressions that are distinguished by the presence or absence of "part...", such as "end" and "end", are used. For example, "end" means a part having a certain range including the "end". The same applies to other expressions accompanied by "part...". [Explanation of symbols]

[0052] 10 Lightning protection coaxial connector 11 Arrester element 12 Elastic body (coil spring) 13 Capacitor 13a, 13b First and second electrodes 14 O-ring 20, 30 First and second central conductors 41-44 First to fourth insulators

Claims

1. A lightning protection coaxial connector connected to a coaxial cable and having an arrester element therein, First and second cylindrical outer conductors; A rod-shaped first central conductor connected to the coaxial cable and in contact with the arrester element; a rod-shaped second central conductor connected to the coaxial cable and arranged coaxially with the first central conductor; a capacitor disposed between the first central conductor and the second central conductor, the capacitor having first and second electrodes; an insulator supporting the first and second central conductors and the capacitor within first and second outer conductors; a coil spring having a hollow portion, the second central conductor penetrating the hollow portion, and biasing the second central conductor toward the first central conductor; Equipped with the second central conductor is supported by an insulator so as to be movable along an axial direction; the second central conductor is biased toward the first central conductor, whereby the first and second electrodes of the capacitor come into contact with the first and second central conductors, A lightning-resistant coaxial connector in which the capacitor is held freely movable along the axial direction within the hollow portion of the insulator by abutting the inner surface of the hollow portion formed in the insulator with the corners of the capacitor.

2. 2. The lightning protection coaxial connector according to claim 1, wherein each of the first and second electrodes of the capacitor is located at both axial ends and includes a flat surface along a plane perpendicular to the axis.

3. 2. The lightning protection coaxial connector according to claim 1, wherein an area of ​​an end face of at least one of the first and second central conductors that abuts against at least one of the first and second electrodes of the capacitor is larger than a cross-sectional area of ​​another portion of at least one of the first and second central conductors.

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