Connection module and cable assembly

A connection module includes a first assembly and a second assembly. The first assembly has a rest portion for resting thereon an exposed portion of a covered electrical wire for differential signal transmission. A cable accommodates the covered electrical wire in a jacket. The exposed portion is not covered with the jacket, exposing a covering of the covered electrical wire. The second assembly has a presser portion pressing the exposed portion rested on the rest portion against the rest portion. A position of the exposed portion is determined by combining the first assembly with the second assembly.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the filing date under 35 U.S.C. § 119(a)-(d) of Japanese Patent Application No. 2020-14001, filed on Jan. 30, 2020.

FIELD OF THE INVENTION

The present invention relates to a connection module and, more particularly, to a connection module connected with a cable for relaying a signal transmitted via the cable.

BACKGROUND

A cable can accommodate a covered electrical wire for differential signal transmission in a jacket. To an end portion of this cable, a connection module for connection with another cable, for example, is connected. In order to connect the connection module to the end portion of the cable, an end portion of the jacket of the cable is stripped off to expose the covered electrical wire. Then, a covering at a leading end portion of the exposed covered electrical wire is stripped off to expose a core wire, and a contact is connected to the core wire by crimping, for example.

The end portion of the cable has the covered electrical wire exposed and is therefore in a different environment from the inside of the jacket, so that an impedance mismatch is likely to occur. In order to suppress this impedance mismatch, Japanese Patent Application No. 2017-204335A and Japanese Patent Application No. 2018-014260A suggest connectors having a metal plate for impedance adjustment positioned near an exposed portion where the covered electrical wire is exposed.

In the connectors of Japanese Patent Application No. 2017-204335A and Japanese Patent Application No. 2018-014260, the metal plate for impedance adjustment is arranged in a position separated from the exposed portion where the covered electrical wire is exposed. Therefore, a structure for locating and fixing this exposed portion needs to be constituted separately from the metal plate for impedance adjustment. In addition, in the case of the connectors of Japanese Patent Application No. 2017-204335A and Japanese Patent Application No. 2018-014260, since the metal plate for impedance adjustment is arranged in a position separated from the exposed portion where the covered electrical wire is exposed, an impedance match can be insufficient.

SUMMARY

A connection module includes a first assembly and a second assembly. The first assembly has a rest portion for resting thereon an exposed portion of a covered electrical wire for differential signal transmission. A cable accommodates the covered electrical wire in a jacket. The exposed portion is not covered with the jacket, exposing a covering of the covered electrical wire. The second assembly has a presser portion pressing the exposed portion rested on the rest portion against the rest portion. A position of the exposed portion is determined by combining the first assembly with the second assembly.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

Exemplary embodiments of the present disclosure will be described hereinafter in detail with reference to the attached drawings, wherein like reference numerals refer to like elements. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will convey the concept of the disclosure to those skilled in the art. Furthermore, several aspects of the embodiments may form—individually or in different combinations—solutions according to the present invention. The following described embodiments thus can be considered either alone or in an arbitrary combination thereof.

FIG. 1is an exploded isometric view of a cable assembly1A according to an embodiment. The cable assembly1A shown inFIG. 1includes a connection module20according to a first embodiment. The cable assembly1A has a cable10, a connection module20, and an outer housing30. The cable10has a tubular jacket11and a pair of covered electrical wires12for differential signal transmission positioned within the jacket11. These two covered electrical wires12are twisted around each other to form a twisted pair wire. The cable10has a shield layer13, shown inFIG. 4A, formed by braiding thin conductors around the pair of covered electrical wires12within the jacket11thereof.

A leading end portion10A of the cable10, shown inFIG. 1, has a structure processed in the following manner. The leading end portion10A has the shield layer13exposed by removing the jacket11. Then, a rear portion of an exposed portion of the shield layer13is covered with a tubular ferrule14, as shown inFIG. 4A. The exposed portion is not covered with the jacket11and exposes a covering of the covered electrical wires12. Further, a front portion of the exposed portion of the shield layer13is folded back on the ferrule14. A portion13A of an exposed non-folded-back portion and a portion13B folded back on the ferrule14of the shield layer13can be seen inFIG. 1.

By folding back the shield layer13on the ferrule14, front end portions121of the two covered electrical wires12are exposed, as shown inFIG. 1. Then, further, a covering at a portion of a front end of the exposed front end portion121of the covered electrical wire12is stripped off to expose a front end portion151of a core wire15inside the covered electrical wire12, shown inFIG. 4A. Then, a contact21is fixed by crimping to the front end portion151of the exposed core wire15. The contact21is a contact constituting the connection module20, and is a female contact into which a rod-like mating contact is inserted.

The connection module20in the embodiment shown inFIG. 1has a first assembly22and a second assembly23, in addition to the contact21connected by crimping to the core wire15of the cable10.

The first assembly22has an insulative inner housing221and a metal shell222enclosing the inner housing221. This metal shell222circumferentially encloses a front portion of the inner housing221. In addition, the metal shell222encloses a lower portion and both side portions of a rear portion of the inner housing221, but is opened upward. This metal shell222is equivalent to an example of a first metal shell defined in the present invention.

An insertion hole221ainto which the contact21is inserted is formed in the front portion of the inner housing221that is circumferentially enclosed by the metal shell222, as shown inFIG. 1. In addition, a rest portion221bon which a portion of the exposed front end portion121of the covered electrical wire12is rested is formed in the upward-opened rear portion of this inner housing221. Furthermore, the inner housing221has a structure in which, when the contact21is inserted to a proper position in the insertion hole221aof the inner housing221, a portion of the front end portion121of the covered electrical wire12rests on the rest portion221b. A portion of the front end portion121of the covered electrical wire12that rests on the rest portion221bis referred to here as exposed portion121a. In an embodiment, the rest portion221bis formed integrally with a member constituting the first assembly22and has not only an action as the rest portion221bbut also another action, and as a portion of the member.

The second assembly23, as shown inFIG. 1, has an inner housing231and a metal shell232. The inner housing231covers from above a portion crimped to the contact21of the core wire15. In addition, a presser portion232a, shown inFIGS. 4A and 4B, for pressing from above the exposed portion121aof the covered electrical wire12resting on the rest portion221bof the first assembly22is provided in the metal shell232. The details will be described later. The metal shell232of the second assembly23is equivalent to an example of a second metal shell defined in the present invention.

The outer housing30has an outer housing main body31and a retainer32, as shown inFIG. 1. The connection module20in an assembled state composed of the contact21, the first assembly22, and the second assembly23is accommodated in the outer housing main body31. Then, the retainer32is fitted onto the outer housing main body31accommodating the connection module20. By fitting this retainer32thereonto, the connection module20is so fixed so to be retained in the outer housing main body31. The description of the outer housing30is finished here, and a cable mounting structure using the connection module20will be described in detail below.

FIGS. 2A and 2Bare exploded isometric views of the cable10and the connection module20. The first assembly22having the leading end portion10A of the cable10positioned therein and the second assembly23in an assembly attitude before assembly are shown inFIGS. 2A and 2B.FIG. 2Ashows the second assembly23positioned above in order to show a structure for positioning the leading end portion10A of the cable10in the first assembly22. In addition,FIG. 2Bshows the second assembly23positioned below in order to show a structure on a side coming into contact with the cable10of the second assembly23.

The cable10is incorporated into the first assembly22, as shown inFIG. 2A. That is, the contact21(seeFIG. 1) is inserted into the insertion hole221aof the inner housing221. Thereupon, the exposed portion121aof the covered electrical wire12rests on the rest portion221b(seeFIG. 1) of the inner housing221. A shield contacting portion222ais provided in a position corresponding to the ferrule14, shown inFIG. 4B, in the metal shell222constituting the first assembly22. The shield contacting portion222ahas a barrel shape, and comes into contact with the portion13B of the shield layer13that is folded back on the ferrule14.

The metal shell232constituting the second assembly23, as shown inFIG. 2B, has the presser portion232aand a shield contacting portion232b. The presser portion232a, as described before, presses the exposed portion121aof the covered electrical wire12resting on the rest portion221bof the first assembly22against the rest portion221bto locate and fix the exposed portion121a. In addition, the shield contacting portion232b, like the shield contacting portion222aof the first assembly22, has a barrel shape, and comes into contact with the portion13B folded back on the ferrule14of the shield layer13. The connection module20performs fixation and impedance matching of the exposed portion121aby this work. Therefore, both good assemblability and high-accuracy impedance matching are achieved.

As shown inFIGS. 2A and 2B, after the leading end portion10A of the cable10is positioned in the first assembly22, the second assembly23is positioned on the first assembly22, as shown inFIGS. 3A and 3B. Then, further, the shield contacting portion222aof the metal shell22of the first assembly22is fixed by swaging onto the shield contacting portion232bof the metal shell232of the second assembly23. By this fixation by swaging, assembly of the connection module20is completed. Further, thereafter, the connection module20is accommodated in the outer housing main body31and so fixed as to be retained by the retainer32. Thereby, the cable assembly1A as the first embodiment of the present invention is completed.

The longitudinal sectional view taken along arrows X-X shown inFIG. 4Ashows the contact21inserted in the insertion hole221aformed in the inner housing221of the first assembly22. In addition, the exposed portion121aof the covered electrical wire12rests on the rest portion221bof the inner housing221of the first assembly22. Furthermore, the presser portion232aof the metal shell232of the second assembly23presses the exposed portion121aresting on the rest portion221bagainst the rest portion221b. The inner housing231of the second assembly23is positioned on a front side in relation to the presser portion232a, and a space232cis formed on a back face side opposite to a presser face231dfacing toward the exposed portion121aof the presser portion232a.

With reference toFIG. 4B, the structure of a portion where the exposed portion121aof the covered electrical wire12is positioned will be further described.

As described above, the rest portion221bis provided in the inner housing221of the first assembly22. Furthermore, a rest face221cof the rest portion221bthat comes into contact with the exposed portion121ais so shaped as to have a recessed groove having a shape along the contour of the exposed portion121a. Because the recessed groove is formed in the rest portion221b, each of the two covered electrical wires12is arranged in a corresponding predetermined position, and a space between these two covered electrical wires12is also a predetermined space. This point also contributes to impedance stabilization.

On the other hand, the presser portion232ais formed in the metal shell232of the second assembly23. The presser face232dof this presser portion232athat comes into contact with the exposed portion121aof the covered electrical wire12has an arcuate shape that is a shape along the contour of the exposed portion121a, and comes into direct contact with the exposed portion121a, covering an upper side of the exposed portion121asubstantially semi-circumferentially, as shown inFIG. 4B. Thus, high-accuracy impedance matching is enabled. On the back face side of this presser portion232aopposite to the presser face232dthe inner housing231does not exist, but the space232cexists.

The presser portion232ais located in a position a little lower than a position shown inFIGS. 4A and 4Bwhen the presser portion232ais separated from the exposed portion121aof the covered electrical wire12. Then, when the second assembly23is rested on the first assembly22, the presser portion232acomes into contact with the exposed portion121a, and elastically deforms toward narrowing the space232cto press the exposed portion121aagainst the rest portion221b. Then, the shield contacting portion222aof the metal shell222of the first assembly22is fixed by swaging onto the shield contacting portion232bof the metal shell232of the second assembly23. Thereupon, the presser portion232aelastically deforms to keep pressing the exposed portion121a. In this manner, a portion of the metal shell232constitutes the presser portion232a, and this presser portion232apresses the exposed portion121a. Thereby, the exposed portion121ais located, and further retained, and simultaneously the impedance of the exposed portion121alowers to make an impedance match with a portion covered with the jacket11of the covered electrical wire12. This presser portion232ahas springiness, and therefore, even if there is a part tolerance, the exposed portion121ais reliably pressed against the rest portion221bby the presser portion232ain an elastically deformed state, and thereby the exposed portion121ais reliably retained in a predetermined position.

In the present embodiment, both the metal shell222of the first assembly22and the metal shell232of the second assembly23have the shield contacting portions222a,232bthat come into contact with the shield layer13of the cable10. Then, the shield contacting portion222aof the first assembly22is fixed by swaging onto the shield contacting portion232bof the second assembly23. Thereby, the first assembly22and the second assembly23are integrated together with the metal shells222,232in contact with each other. These metal shells222,232are in contact with the shield layer13of the cable10and retained at the same electric potential as the shield layer13. In addition, the inside of the connection module20is shielded by combining these metal shells222,232. However, it is only necessary that the inside of the connection module20be shielded by combining these metal shells222,232. That is, the structure does not need to be a structure in which both the metal shells222,232come into contact with the shield layer13, but may also be a structure in which either one of the metal shells222,232comes into contact with the shield layer13, and both the metal shells222,232come into contact with each other. In an embodiment, the second metal shell232achieves both the function of pressing the exposed portion121aand the shielding function of the connection module20in cooperation with the first metal shell direct

It should be noted that the description here has been made taking as an example the cable10having the shield layer13. However, the structure in which the exposed portion121awhere the covered electrical wire12is exposed is rested on the rest portion221band pressed by the conductive presser portion232ais not relevant to whether or not the cable10has the shield layer13. That is, the present invention is applicable to a cable not having a shield layer. By applying the present invention, regardless of whether or not the cable10has the shield layer13, the impedance at the leading end portion of the covered electrical wire12can be matched with the impedance of portions of the covered electrical wires12that are twisted around each other to form a twisted pair.

In addition, the presser portion232ahere is constituted as a portion of the metal shell232. Therefore, the presser portion232ais made of a metal material. However, though it is preferred that the presser portion232ahave a high conductivity, the presser portion232adoes not necessarily need to be made of a metal material. That is, as long as the presser portion232ais made of a material having a higher conductivity than air, the impedance of the exposed portion221bof the covered electrical wire12can be made close to the impedance of the portions of the covered electrical wires12that are twisted around each other to form a twisted pair.

In addition, here, the contact21is connected by crimping to the core wire15, but, instead of crimping connection, they are connected together by another connection, for example, a soldering connection, or the like.

FIG. 5is an exploded isometric view of a cable assembly1B as a second embodiment of the present invention. Here, a component corresponding to a component of the cable assembly1A of the first embodiment shown inFIG. 1is denoted by the same reference sign as a reference sign used inFIG. 1even if they differ in shape or the like, and their functional difference will be described.

A cable10of a cable assembly1B of this second embodiment is a cable having the same structure as the cable10of the first embodiment. However, a male contact21is connected by crimping to the front end portion151of the core wire15.

In addition, a fitting-in space222binto which a front end portion20aof the connection module20shown inFIG. 1is formed in the first assembly22of the connection module20constituting the cable assembly1B of the second embodiment. Though this first assembly22is also provided with the inner housing221, the inner housing221is positioned on a rear side in relation to this fitting-in space222b, and invisible inFIG. 5. However, in the case of the second embodiment, similarly, the rest portion221b(invisible inFIG. 5) similar to one in the first embodiment is provided in this inner housing221.

The second assembly23of this second embodiment is a component having the same structure and the same shape as the second assembly23of the first embodiment.

A mating space311that a front end portion30aof the outer housing30of the first embodiment enters is formed in the outer housing main body31of the outer housing30of this second embodiment1B. The retainer32of this second embodiment1B is different in shape from the retainer32of the first embodiment, but has the same function.

The cable assembly1B of this second embodiment is assembled in the same manner as the cable assembly1A of the first embodiment. Then, the front end portion30aof the outer housing30of the first embodiment is fitted into the mating space311of the outer housing30of this second embodiment. Thereupon, the front end portion20aof the connection module20of the first embodiment is inserted into the fitting-in space222bof the connection module20of the second embodiment. Then, further, the male contact21of the second embodiment is inserted into the female contact21of the first embodiment. In this manner, the cable assembly1A of the first embodiment and the cable assembly1B of the second embodiment are connected together. In this manner, the present invention is applicable regardless of the shape of the contact21or regardless of the shape of the outer housing30.

FIGS. 6A and 6Bare a longitudinal sectional view and a cross sectional view, respectively, of another example of a connection module20equivalent toFIGS. 4A and 4Bof the connection module shown inFIGS. 1 to 4B. The same reference signs as those used inFIGS. 4A and 4Bare used here, and only their differences will be described.

In the case of the connection module20shown inFIGS. 1 to 4B, as shown inFIGS. 4A and 4B, the rest portion221bis formed as a portion of the inner housing221. In addition to the rest portion221b, the insertion hole221ainto which the contact21is inserted is formed in this inner housing221. That is, the inner housing221having the rest portion221bformed therein is a member taking not only a role as the rest portion221bbut also a role to retain the contact21inserted into the insertion hole221a, or the like.

On the other hand, in the case of another example of the connection module20shown inFIGS. 6A and 6B, the rest portion221bis a component separate from the inner housing221. That is, this rest portion221bis incorporated separately from the inner housing221when the connection module20is assembled. In this manner, the rest portion221bmay be a single independent component.

The connection module20and the cable assembly1A and1B according to the various embodiments achieve both good assemblability and high-accuracy impedance matching.