JP3029246B2 - Coaxial connector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coaxial connector, and more particularly to a coaxial connector which can be used for a coaxial cable having an outer conductor formed of a metal thin film for use in a superconducting device . Generally, a coaxial connector is a general-purpose component for connecting coaxial cables that mainly transmit high-frequency signals or between a coaxial cable and a device, and various types are used depending on the type and use of the cable.

[0002]

2. Description of the Related Art For example, a BNC type is one of well-known coaxial connectors, and this connector is used for connecting a coaxial cable having an outer conductor in which a fine metal wire is woven. BN
The procedure for assembling the C-type connector to the coaxial cable is generally as follows. Strip the outer sheath of the cable to expose the reticulated external conductor. Cut and adjust the appearance, solder the center pin to the tip of the inner conductor (also called the center conductor) of the cable, pass the coupling nut through the cable, insert the center pin first and insert it from the back of the housing, Screw the coupling nut to complete.

However, such a BNC type coaxial connector cannot be applied to a coaxial cable in which an outer conductor is formed of a metal thin film (hereinafter referred to as a "thin film coaxial cable"). This is because this coaxial cable does not have a thin metal wire to be entangled with the gasket. As an example of a thin film coaxial cable,
There is a "coaxial cable" for a superconducting device previously proposed by the present applicant (Japanese Patent Application No. Hei 7-281155 / Oct. 30, 1995).

In general, a superconducting device requires an extremely low-temperature operating environment. Therefore, in order to prevent temperature fluctuations and cooling efficiency, it is necessary to suppress heat conduction in all parts including a signal path as much as possible. The applicant has concluded that the transmission contributing portion of the high-frequency signal in the coaxial cable has only the outer peripheral surface of the inner conductor and the inner peripheral surface of the outer conductor due to the “skin effect” of the high-frequency signal. A dielectric of a predetermined thickness also contributes, but is omitted for convenience of explanation.)
That is, under the knowledge that only a very thin portion of the two conductors in contact with the dielectric contributes to the transmission of the high-frequency signal, the high-frequency characteristics are impaired, in particular, by forming the outer conductor having large heat conduction with a metal thin film. We have proposed a coaxial cable that significantly suppresses heat conduction without any problems.

[0005]

As described above, the conventional coaxial connector has a disadvantage that it cannot be applied to a thin-film coaxial cable, particularly a coaxial cable of the prior application suitable for use in a superconducting device. This is a technical issue that must be resolved immediately because it hinders the commercialization of the technology.

[0006] As in the SMA-P Straight called coaxial connector, although both the assembly of when soldering the outer conductor and the gasket of the thin coaxial cable is possible, thin coaxial used for superconductive devices Since the dielectric of the cable is covered only with a metal thin film, the protection strength against the dielectric is weak, the dielectric expands easily due to the heat of the solder, and the thickness (the distance between the inner and outer conductors) changes, and the frequency characteristics change. Because of the changes, soldering is a totally unacceptable means. Moreover, the metal thin film is as thin as several μm as described later.
Therefore, there is a problem that it is easily damaged.

Accordingly, an object of the present invention is to provide a coaxial connector applicable to a coaxial cable in which an outer conductor is formed of a metal thin film, and to provide a useful technique which contributes to practical use of a superconducting device.

[0008]

SUMMARY OF THE INVENTION The above object is achieved by a substantially cylindrical housing, a coaxial cable outer circumferential surface is shaped <br/> formed in the outer conductor with a surface abutting of the housing made of a metal thin film,
Holding means and, if necessary, a thickness along the axial direction of the housing.
A spacer member that changes only, the coaxial cable is inserted from one end side of the housing, and a center pin attached to a tip of a center conductor of the coaxial cable is exposed at the other end side of the housing. In the coaxial connector of the structure to be
(A) one end of the housing is configured to be deformable at least in a radial direction of the housing, and a holding means for holding a deformed state in a small radial direction is provided; or
(B) Inserting a spacer member whose thickness changes along the axial direction of the housing between the inner peripheral surface on one end side of the housing and the outer peripheral surface of the coaxial cable, and maintaining the inserted state of the spacer member This can be achieved by providing a holding means.

Preferably, the holding means (a) has an engaging portion which engages with an outer peripheral surface between one end and the other end of the housing, and an inner diameter smaller than an outer diameter of one end of the housing. Or (b) holding means for engaging with an outer peripheral surface between one end and the other end of the housing; and the spacer member. And a pressing surface that presses the end surface on the maximum thickness side of the above.

According to (a), when one end of the housing is deformed in the small radius direction, the outer peripheral surface of the coaxial cable is firmly pressed and held by the inner peripheral surface of one end surface of the housing.
Or, according to (b), with the insertion of the spacer member,
A force acts in the direction of increasing the distance between the inner peripheral surface at one end of the housing and the outer peripheral surface of the coaxial cable, and the outer peripheral surface of the coaxial cable is firmly pressed and held by this force.

Therefore, (a) and (b) can be assembled to a coaxial cable formed of a metal thin film without the need for soldering. One can be eliminated. Alternatively, the first cover portion, which is entirely made of a flexible material and has an inner diameter slightly smaller than the diameter of the largest outer portion of the housing, and the inner diameter slightly smaller than the diameter of a coaxial cable in which the outer conductor is formed of a metal thin film. When the sleeve having the second cover portion and the second cover portion tapered toward the tip is used for the coaxial connector, the tip of the housing (FIG. 2) is formed by the tapered shape of the second cover portion. ) Can be dispersed. For example, even when bending stress is applied to the coaxial cable, local stress concentration does not occur in the outer conductor of the coaxial cable in contact with the front end of the housing. The durability can be improved by avoiding breakage of the conductor.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a superconducting device according to the present invention.
It is a figure showing an example of a coaxial connector applicable to a chair . In FIG. 1, reference numeral 1 denotes a substantially cylindrical housing.
At a substantially central portion of the housing 1 in the axial direction, a specific shape portion 1a for using a jig such as a spanner is provided, and a tip portion of the specific shape portion 1a engages with a mating connector (not shown). A movable cap portion 1b is provided.

One end 1c and the other end 1d of the housing 1
(The side having the cap portion 1b)
A cylindrical piece 1f made of a dielectric material such as Teflon is mounted inside the hole 1e. An inner conductor (center conductor) 2a of the coaxial cable 2 is inserted into a shaft hole of the cylindrical piece 1f, and a center pin 1g is attached to a tip of the inner conductor 2a.

The coaxial cable 2 comprises an inner conductor 2a, an outer conductor 2b formed of a thin metal film, and both conductors 2a, 2b.
It has a dielectric 2c of a predetermined thickness that insulates between them, and corresponds to a “thin-film coaxial cable” that can be provided to the superconducting device described at the beginning. And the same is applied to the present invention.
The shaft cable has an outer peripheral surface as shown in FIG.
Are all external conductors made of a metal thin film,
The structure is such that the surface of the housing directly contacts the surface.
Here, the point of the present embodiment is that the metal thin film as the outer conductor is used.
The structure is such that the surface of the membrane is not damaged.
Such as tangling or soldering connector members
First, the housing 1 is not assembled.
Secondly, it is characterized in that one end side 1c of the housing 1 can be deformed at least in the radial direction of the housing 1, and secondly, it is provided with holding means 3 for holding the deformed state of the housing 1 in the small radial direction.

FIG. 2 is a schematic view of a main part for explaining such points. In this figure, one end 1c of the housing 1 is tapered and has several notches 1h extending in the axial direction. On the other hand, the holding means 3 has an inner peripheral surface 3a formed in a tapered shape,
The inner diameter D ₁ of the small opening side of the inner peripheral surface 3a, the housing 1
Of (one end 1c; hereinafter the same) greater than the outer diameter D ₂ of the tip, and than the outer diameter D ₃ in the vicinity of the location that contains a distance corresponding to the thickness L of the holding means 3 from the distal end of the housing 1 There is a small relation D ₂ <D ₁ <D ₃ (1).

According to such a configuration, the coaxial cable 2
Is inserted from one end side 1c of the housing 1 (see the arrow A in FIG. 2), and the holding means 3 is pushed over the one end side 1c of the housing 1 in the direction of the arrow A to push the holding means 3 along with the pushing. The inner diameter of the side 1c changes to the reduction side, and as a result, the outer peripheral surface of the coaxial cable 2 is securely held by the inner peripheral surface of the one end 1c of the housing 1.

Therefore, the coaxial cable 2 can be assembled to the housing 1 without performing a heating operation such as soldering, and the problem of expansion of the dielectric 2c can be avoided. 2 can be applied without difficulty to coaxial cables having no net-shaped outer conductor, for example, coaxial cables having an outer conductor formed of a metal thin film. It can provide a very useful technology for superconducting application fields, which can overcome one of the obstacles that hinder the development.

Here, two preferable examples of the mechanism of engagement between the holding means 3 and the housing 1 will be described. FIG. 3 is a diagram showing a first example. In this figure, a screw thread 3b is formed on the inner peripheral surface of the holding means 3, and
Threads 1i are also formed on the outer peripheral surface of the one end side 1c of the opposite housing 1. The holding means 3 is engaged with the housing 1 by screwing the threads 3b of the holding means 3 into the threads 1i of the housing 1. According to this, by adjusting the amount of screwing, one end 1 of the housing 1
There is an advantage that the degree of deformation of c can be adjusted and the holding force on the coaxial cable 2 can be controlled.

FIG. 4 is a diagram showing a second example. In this figure, a projection 3c which is continuous in the circumferential direction is formed on the inner circumferential surface of the holding means 3, and the outer circumferential surface of one end 1c of the opposing housing 1 is continuous in the circumferential direction. A groove 1j is formed. The holding means 3 is fitted into the one end 1c of the housing 1, and the holding means 3 is pushed forward to engage the projection 3c with the groove 1j, thereby engaging the holding means 3 with the housing 1. According to this, there is an advantage that a one-touch engagement operation is performed, and the assembling work on the coaxial cable 2 can be simplified.

In FIG. 4, the projections 3c and the grooves 1j do not always need to be continuous in the circumferential direction. It may be intermittent at appropriate intervals. FIG. 5 is a view showing another embodiment of the coaxial connector according to the present invention. In this figure, 10
Denotes a coaxial cable, 11 denotes a housing, and 12 denotes a spacer member. The illustration of the housing 11 is omitted in FIG.

Housing 1 for inserting coaxial cable 10
The diameter of the inner peripheral surface of one end 11a gradually increases in the axial direction from the inside to the outside, and the inner peripheral surface and the coaxial cable 1
The spacer member 12 is pushed into a gap between the outer peripheral surface of the spacer member 0 and the outer peripheral surface of the spacer member 12. The spacer member 12 has a substantially cylindrical shape and is formed such that its thickness changes in the axial direction. Preferably, the spacer member 12 further moves from the thin end surface 12a toward the thick end surface 12b (thickness). Several slits 12c (not reaching the end face 12b on the meat side ) are provided.

According to such a configuration, the spacer member 1
By using 2 as a "wedge", the housing 11 can be easily assembled to the coaxial cable 10 without performing a heating operation, and the same effect as in the above embodiment can be obtained. The means for holding the spacer member 12 of this embodiment includes, for example, FIG.
And a one-touch type shown in FIG.

As described above, according to this embodiment, the heat resistance
The coaxial cable can be attached to the housing without heating work such as soldering for the superconducting coaxial cable lacking , and the outer conductor is a metal thin film.
For superconducting coaxial cables that are susceptible to mechanical damage,
Since Ru can cover weakness of the coaxial cable by the housing, the superconducting device form an outer conductor of a metal thin film
This is advantageous in that a suitable coaxial connector can be realized using a “thin film coaxial cable” that can be provided . However, since the thickness of the outer conductor of the thin-film coaxial cable is extremely thin (several μm in a frequency band of several gigahertz), for example, when bending stress is applied to the coaxial cable, the tip of the housing (see reference numeral 1c in FIG. 2) It is undeniable that local stress concentration occurs in the outer conductor in contact with the outer conductor, and that the outer conductor in that portion is damaged by cracks or the like. Therefore, there is still room for improvement in terms of durability. In particular, in a superconducting applications, the use of the refrigerator for cryogenic cooling is essential, since the vibration of the refrigerator is easily applied to the coaxial cable, when applied to the art, by all means, resolved This is an issue that must be kept.

FIG. 6 is an improved constitutional view of the above embodiment in which the durability is improved. Elements common to the above embodiment (FIG. 1) are denoted by the same reference numerals. In FIG.
Is a sleeve. The sleeve 20 is entirely made of a flexible material (Note 1), and has a specific shape 1a of the housing 1.
Cover portion 20 having an inner diameter slightly smaller than the diameter of
a, and a second cover portion 20b having an inner diameter slightly smaller than the diameter of the coaxial cable 2, and wherein the second cover portion 20b is tapered toward the tip. Note 1: A material that is slightly softer than the coaxial cable 2 and does not become very hard even at low temperature is preferable. For example, in the case of a coaxial cable under the following conditions, PT
Fluorine resins such as FE, PFA, FEP, ETFE, and CTFE can be used.

Outer diameter: 1 mm to 4 mm Film thickness of outer conductor: 2 μm to 5 μm Diameter of inner conductor: 0.2 mm to 1 mm Material of outer conductor: Cu Material of center conductor: Cu or silver-plated steel wire Dielectric material : Teflon In such a configuration, after attaching the coaxial cable 2 to the housing 1, the inner diameter of the first cover portion 20 a of the sleeve 20 is shifted while the sleeve 20 previously inserted through the coaxial cable 2 is shifted toward the housing 1. When the cover 20 is put on the specific shape portion 1a of the housing 1 while enlarging, the sleeve 20 can cover the mounting portion of the coaxial cable 2 and the housing 1, and the tapered shape of the second cover portion 20b of the sleeve 20 allows the housing 1 can be dispersed. Therefore, a particularly advantageous effect that a sufficient durability can be ensured even when applied to a superconducting application field is obtained.

In the example of FIG. 6, the first cover 20a
Is slightly smaller than the diameter of the specific shape portion 1a of the housing 1, but is not limited to this. In short, it is only necessary that the sleeve 20 can be elastically engaged with the housing 1, and at least the first cover portion 20a has to have an inner diameter slightly smaller than the diameter of the largest outer portion of the housing body.

[0027]

According to the present invention, it is possible to provide a coaxial connector applicable to a coaxial cable in which an outer conductor is formed of a metal thin film, and to provide a useful technique which contributes to the practical use of a superconducting device. A particularly advantageous effect is obtained. Alternatively, if the sleeve of the present invention is used, local stress concentration does not occur in the outer conductor of the coaxial cable in contact with the tip of the housing, so that damage to the outer conductor at that portion can be avoided and durability can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional structural view of one embodiment.

FIG. 2 is an external view of a main part of one embodiment.

FIG. 3 is a diagram showing a mechanism of engagement according to one embodiment (first example);
It is.

FIG. 4 is a diagram showing a mechanism of engagement according to one embodiment (second example);
It is.

FIG. 5 is a sectional structural view of a main part of another embodiment.

FIG. 6 is a sectional structural view of an improved embodiment.

[Explanation of symbols]

 1: Housing 1c: One end 1d: Other end 1g: Center pin 2: Coaxial cable 2a: Inner conductor (center conductor) 3: Holding means 11: Housing 11a: One end 10: Coaxial cable 12: Spacer member 20: Sleeve 20a: 1st cover part 20b: 2nd cover part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-250571 (JP, A) JP-A-4-282579 (JP, A) JP-A-9-102217 (JP, A) JP-A-9-102 129041 (JP, A) JP-A-1-317003 (JP, A) JP-A-3-37974 (JP, A) JP-A-4-74876 (JP, U) JP-A-4-1155783 (JP, U) Japanese Utility Model Application Showa 61-133986 (JP, U) Japanese Utility Model Application Hei 3-19279 (JP, U) Japanese Utility Model Utility Model Hei 3-71578 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01R 17/04

Claims (5)

(57) [Claims] 1. A substantially cylindrical housing and an outer peripheral surface formed of thin metal.
The outer conductor made of a film is
Contacting coaxial cable and holding means capable of holding a deformed state
With the door, insert the coaxial cable from one end of the housing to expose the center pin attached to the tip of the center conductor of the coaxial cable to the other end of said housing, at least the housing and one end of the housing radially deformable configured to, the deformation state of the small radial
A coaxial connector characterized by being held by holding means . 2. A substantially cylindrical housing and an outer peripheral surface formed of thin metal.
The outer conductor made of a film is
Abutting coaxial cable and along the axial direction of the housing
The coaxial cable is inserted from one end of the housing , and a center pin attached to a tip of a center conductor of the coaxial cable is exposed at the other end of the housing. , coaxial connector the spacer member inserted between the outer peripheral surface of one end side of the inner peripheral surface and the coaxial cable of the housing, and the insertion state of the spacer member, characterized in that holding by said holding means . 3. The holding means includes an engaging portion that engages with an outer peripheral surface between one end and the other end of the housing, and an inner diameter smaller than an outer diameter of one end of the housing. The coaxial connector according to claim 1, wherein the coaxial connector has an inner peripheral surface. 4. The holding means includes: an engaging portion that engages with an outer peripheral surface between one end and the other end of the housing; a pressing surface that presses an end surface of the spacer member on a maximum thickness side; The coaxial connector according to claim 2, comprising: 5. A first cover part which is entirely made of a flexible material and has an inner diameter slightly smaller than the diameter of the largest outer part of the housing, and a second cover part having an inner diameter slightly smaller than the diameter of the coaxial cable. The sleeve for a coaxial connector according to claim 1 or 2, wherein the sleeve is formed so that the second cover portion is tapered toward the front end.