This application is based on and claims the benefit of priority from Japanese Patent Application No. 2021-035413, filed on 5 Mar. 2021, the content of which is incorporated herein by reference.
The present invention relates to an electrical connector. In particular, the present invention relates to a small-sized coaxial connector configured on an end of a coaxial cable and to a structure of the coaxial connector including a shell electrically connected to an external conductor of the coaxial cable on one end side and formed in a cylindrical shape on the other end side.
The coaxial connector fixed to the terminal of the coaxial cable is connected to a receptacle mounted on a printed circuit board, and thus a high frequency signal can be transmitted from the coaxial cable to the printed circuit board. Alternatively, the high frequency signal can be transmitted from the printed circuit board to the coaxial cable.
In general, the coaxial cable is configured by a circular central conductor, a dielectric surrounding the central conductor, an external conductor such as a braided wire surrounding the dielectric, and an insulating sheath covering and protecting the external conductor. Further, the coaxial connector includes a housing and a bellows-shaped contact. The insulating sheath of the coaxial cable is fixed on one end side of the shell. Further, the external conductor of the coaxial cable is electrically connected on one end side of the shell. Further, the other end side of the shell is formed in a cylindrical shape (for example, see Japanese Unexamined Patent Application Publication No. 2019-169361).
According to Japanese Unexamined Patent Application Publication No. 2019-169361, the shell and the contact are electrically insulated by the housing. The contact is disposed inside the housing and is surrounded by some of external contacts of the shell in an annular shape. The contact is molded integrally with the housing by molding with a synthetic resin (insulating resin). The housing is provided with a disk portion including a columnar fitting portion protruding in a plate thickness direction, and the contact is disposed in a contact accommodation space that is opened on one surface side of the disk portion.
The contact includes a strip-shaped metal plate, and a base end side of the metal plate is an installation surface of a central conductor of the coaxial cable and is exposed to a surface of the housing. A pair of contact pieces are provided on a tip end side of the metal plate to face each other in a direction substantially perpendicular to the metal plate. When a mating contact is inserted between the pair of contact pieces, the pair of contact pieces spreads in a direction away from each other in a substantially horizontal direction, and sandwich the mating contact by springiness (elasticity) of approaching. Thus, the pair of contact pieces reliably come into contact with the mating contact and are electrically connected to the mating contact.
According to Japanese Unexamined Patent Application Publication No. 2019-169361, the columnar fitting portion can be inserted inside the cylindrical shell formed in the mating coaxial connector. When the fitting portions are inserted inside the cylindrical shell, a cylindrical mating contact disposed in a center of the cylindrical shell can be electrically connected to the pair of contact pieces disposed in the contact accommodation space.
As described above, the pair of contact pieces of the contact are configured to be displaced in the direction away from each other from a facing position in a substantially horizontal direction. In order to give an allowance for the displacement, the size of the contact accommodation space becomes large, and thus the outer diameter of the columnar fitting portion is made large. Accordingly, the size of the annular external contact surrounding the fitting portion becomes also large. In other words, a two-point contact structure of the contact according to the related art has a problem that downsizing of the coaxial connector is not easy.
The present invention has been made in view of the above problems, and is intended to provide a coaxial connector capable of further downsizing by changing a structure of a contact provided in the coaxial connector.
The present invention relates a contact for a coaxial connector capable of being connected to a cylindrical mating contact, and has a structure in which the contact externally contacts the mating contact by three-point contact. The three-point contact type contact is configured by a pair of fixed terminals located at a set of vertices among vertices of a virtual equilateral triangle inscribed in the mating contact and a movable terminal that can be elastically deformed located at the other vertex. This makes it possible to make the connector smaller than the coaxial connector using a two-point contact type contact that requires the terminals to spread in the direction away from each other.
An embodiment of the present invention will be described below with reference to the drawings.
Configuration of Coaxial Connector
First, a configuration of a coaxial connector according to an embodiment of the present invention will be described.
Overall Configuration
With reference to
The coaxial plug 10 includes a contact 1 by a three-point contact, a housing 3 including first and second connection bases, and a conductive shell 5. Further, the housing 3 includes a block-shaped crimp housing 7. Further, the shell 5 includes a pair of first barrels 521 and 521 and a pair of second barrels 522 and 522.
The contact 1 can electrically connect a cylindrical central contact 2, which is a mating contact, and the central conductor Wc of the coaxial cable Cb (see
Referring to
The pair of fixed terminals 11s and 11s are disposed to face each other in a direction substantially orthogonal to a longitudinal direction in which the metal plate 11t extends. The movable terminal 12s that can be elastically deformed is a plate spring terminal disposed in a state of facing an intermediate portion of the pair of fixed terminals 11s and 11s. When the central contact 2 is inserted into the space surrounded by the pair of fixed terminals 11s and 11s and the movable terminal 12s, the pair of fixed terminals 11s and 11s and the movable terminal 12s can externally contact an outer periphery of the central contact 2 by three-point contact.
Referring to
Referring to
Referring to
Referring to
An external contact 6 of a mating connector 20 to be described below can be inserted inside the cylindrical portion 51 (see
Referring to
More specifically, the extension portion 52 includes a pair of first barrels 521 and 521 and a pair of second barrels 522 and 522. The pair of first barrels 521 and 521 can press the crimp housing 7 against the second connection base 32, and thus can crimp the central conductor Wc of the coaxial cable Cb against the installation surface 321 of the contact 1. The pair of second barrels 522 and 522 can crimp the external conductor Wb from above the dielectric Di.
When the pair of second barrels 522 and 522 crimp the external conductor Wb surrounding the dielectric Di, the external conductor Wb and the shell 5 can be electrically connected. Thereby, the coaxial plug 10 can be fixed to the terminal of the coaxial cable Cb.
Referring to
Referring to
Configuration of Mating Connector Next, a description will be given with reference to
The central contact 2 is related to a main body 21 formed on a concentric circle of the central contact and a lead terminal 2r of the central contact 2, and the lead terminal 2r can be soldering-joined to a signal pattern in a wiring pattern of the printed circuit board (not shown). The external contact 6 is related to a main body 61, which is formed on the concentric circle of the main body 21 and has an opened upper surface, and a lead terminal 6r of the external contact 6, and the lead terminal 6r can be soldering-joined to a ground pattern in the wiring pattern of the printed circuit board (not shown).
The housing 4 is formed in a shape of a rectangular plate. The central contact 2 and the external contact 6 are integrally molded by the housing 4, and thus the central contact 2 and the external contact 6 are fixed to each other. A dielectric material is abundant inside the housing 4, and the central contact 2 and the external contact 6 are electrically insulated from each other.
When the coaxial plug 10 is connected to the receptacle 20, the central conductor Wc existing in the coaxial cable Cb can be connected to the central contact 2, and the external conductor Wb existing in the coaxial cable Cb can be connected to the external contact 6. Thereby, it is possible to transmit a high frequency signal from the coaxial cable Cb to the printed circuit board, and to transmit a high frequency signal from the printed circuit board to the coaxial cable Cb.
Configuration of Contact
A configuration of the contact 1 according to the embodiment will be described below with reference to
The pair of fixed terminals 11s and 11s are located at a set of vertices, among vertices of a virtual equilateral triangle inscribed in the central contact 2. On the other hand, the movable terminal 12s is located at the other vertex of the virtual equilateral triangle. Then, the contact surface of the movable terminal 12s is disposed in a state of facing the intermediate portion of the pair of fixed terminals 11s and 11s. More specifically, the movable terminal 12s is disposed in a state of being elastically deformed in a direction along a straight line passing through the vertex of the virtual equilateral triangle, at which the movable terminal 12s is located, and the intermediate portion of the pair of fixed terminals 11s and 11s.
When the central contact 2 of the receptacle 20 is inserted into the accommodation space 31r of the first connection base 31, the outer periphery of the central contact 2 comes into contact with ridge portions (contact edges) of the pair of fixed terminals 11s and 11s located in the accommodation space 31r and comes into contact with the movable terminal 12s. In this way, the contact 1 can make three-point contact with the central contact 2.
Configuration of Housing
A configuration of the housing 3 according to the embodiment will be described below with reference to
Referring to
More specifically, the housing 3 is formed so that a difference between a distance D2 from the tip end side of the contact 1 to the bottom surface of the shell 5 and a distance D1 from the base end side of the contact 1 to the bottom surface of the shell 5 is made as small as possible. A thickness of the housing 3 is substantially the same on the tip end side and the base end side of the contact 1. In other words, there is a relation of D2≈D1.
On the tip end side and the base end side of the contact 1, it is possible to inhibit disturbance of impedance by making the difference small between the distance from the tip end side of the contact 1 (metal plate lit) to the shell 5 and the distance from the base end side of the contact 1 to the shell 5. Thereby, it is possible to increase a high frequency band of the high frequency signal transmitted to the coaxial plug 10. For example, VSWR (voltage standing wave ratio) can be inhibited to less than “1.5” up to 60 GHz.
Configuration of Shell
A configuration of the shell 5 according to the embodiment will be described below with reference to
In the extension portion 52, the pair of first barrels 521 and 521 and the pair of second barrels 522 and 522 are preferably bent and shaped in a state of being open. Further, the bottom plate piece 52b of the cylindrical portion 51 is preferably shaped in the extension portion 52.
The pair of first barrels 521 and 521 can be bent to enclose the crimp housing 7 attached to the second connection base 32. When the crimp housing is pressed by the pair of first barrels 521 and 521, the central conductor Wc placed on the installation surface 321 of the second connection base 32 can be firmly crimped to the installation surface 321.
The pair of second barrels 522 and 522 can be bent to enclose the external conductor Wb surrounding the dielectric Di. Thus, the pair of second barrels 522 and 522 are crimped to the external conductor Wb to electrically connect the external conductor Wb and the shell 5 to each other and to fix the coaxial connector 10 to the terminal of the coaxial cable Cb.
Configuration of Crimp Housing
Next, referring to
One end of the crimp housing 7 is provided with a pair of lances 7r and 7r. The pair of lances 7r and 7r are disposed across straddle the slot 7s. A pair of guide grooves 7g and 7g are provided between each of the pair of lances 7r and 7r and the slot 7s. A pair of notches 7n and 7n are provided between the guide grooves 7g and 7g and the lances 7r and 7r, respectively. Thereby, deformation accompanied by elasticity is allowed at peripheral parts of the lances 7r and 7r.
On the other hand, referring to
Referring to
In the coaxial plug 10 according to the embodiment, the central conductor Wc is pressed against and crimped to the installation surface 321 using the crimp housing 7 and the pair of first barrels 521 and 521 that press the crimp housing 7. Thus, the central conductor Wc is reliably bonded to the contact 1.
Operational Effects of Coaxial Connector
Next, operational effects of the coaxial connector 10 according to the embodiment will be described.
Referring to
Referring to
Referring to
The coaxial connector according to the present invention has a configuration in which it externally contacts the mating contact by three-point contact. The pair of fixed terminals act as contact edges to the mating contact, and the allowance to spread in the direction away from each other in the horizontal direction cannot be required or can be minimized. The elastic displacement of the movable terminal provided only one is mainly within the direction toward the intermediate portion of the pair of fixed terminals and the opposite direction. Also in the shell, the thickness of the cylindrical portion surrounding the first connection base is made small as much as possible, and thus the coaxial connector can be downsized.
While preferred embodiments of the present invention have been described and illustrated above, it is to be understood that they are exemplary of the invention and are not to be considered to be limiting. Additions, omissions, substitutions, and other modifications can be made thereto without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered to be limited by the foregoing description and is only limited by the scope of the appended claims.
Number | Date | Country | Kind |
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2021-035413 | Mar 2021 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
20150056866 | Osaki | Feb 2015 | A1 |
20190296459 | Miyazaki | Sep 2019 | A1 |
20200203859 | Haga | Jun 2020 | A1 |
Number | Date | Country |
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204045796 | Dec 2014 | CN |
2008-147094 | Jun 2008 | JP |
3191979 | Jul 2014 | JP |
2016-192274 | Nov 2016 | JP |
2017-174624 | Sep 2017 | JP |
2017208257 | Nov 2017 | JP |
2019-169361 | Oct 2019 | JP |
Entry |
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Translated abstract of JP2017208257A (Year: 2017). |
Office Action of Japanese Patent Application No. 2021-035413: Notice of Reasons for Refusal issued Jun. 25, 2024 (3 sheets, 5 sheets translation, 8 sheets total). |
Number | Date | Country | |
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20220285894 A1 | Sep 2022 | US |