JP7109415B2 - shield terminal - Google Patents

Description

The present invention relates to shield terminals.

Patent Document 1 discloses a shield terminal in which an inner conductor terminal is housed in a dielectric and the dielectric is surrounded by an outer conductor terminal. When trying to use this type of shield terminal in a high-speed communication circuit, it is preferable to match the impedance in order to improve the reliability of communication performance.

JP 2012-129103 A

If the impedance of the shield terminal is low, a means for increasing the impedance is to use a material with a low dielectric constant, such as polypropylene, as the dielectric material. However, since polypropylene has low mechanical rigidity, it cannot be said to be desirable as a material that functions to stably hold the inner conductor terminals.

The shield terminal of the present disclosure has been completed based on the circumstances as described above, and aims to increase the impedance without lowering the rigidity of the dielectric.

The shield terminal of the present disclosure is
a dielectric made of synthetic resin in which a conductor housing chamber is formed;
an inner conductor housed in the conductor housing chamber;
an outer conductor surrounding the dielectric;
a wall portion forming the conductor housing chamber and having an air chamber formed therein;
A square tube-shaped main body portion into which the mating conductor is electrically connected is formed at the front end portion of the inner conductor,
A locking portion is formed at the rear end of the main body,
A retaining portion is formed on the bottom wall portion of the conductor housing chamber to restrict relative displacement of the inner conductor to the rear by engaging the locking portion,
The air chamber is arranged only in a region of the bottom wall portion corresponding to the main body portion in the front-rear direction and forward of the retaining portion.

According to the present disclosure, the impedance can be increased without reducing the stiffness of the dielectric.

FIG. 1 is a cross-sectional view showing a state in which the shield terminal of Example 1 is attached to a housing. FIG. 2 is a cross-sectional view of a shield terminal. FIG. 3 is a cross-sectional view of the terminal unit. FIG. 4 is a plan view showing a state in which the inner conductor is attached to the first part. FIG. 5 is a perspective view of the first part. FIG. 6 is a perspective view showing the upside-down state of the first component. FIG. 7 is a perspective view showing the upside-down state of the second component. FIG. 8 is a perspective view of the second part. FIG. 9 is a perspective view of an outer conductor. FIG. 10 is a perspective view showing an inverted state of the outer conductor.

[Description of Embodiments of the Present Disclosure]
First, the embodiments of the present disclosure will be listed and described.
The shield terminal of the present disclosure is
(1) A synthetic resin dielectric having a conductor housing chamber formed therein, an inner conductor housed in the conductor housing chamber, an outer conductor surrounding the dielectric, and the conductor housing chamber, and a wall portion in which an air chamber is formed. A rectangular tube-shaped main body portion into which a mating conductor is electrically connected is formed at the front end portion of the inner conductor, and is locked to the rear end of the main body portion. A retaining portion is formed on the bottom wall portion of the conductor housing chamber to restrict relative displacement of the inner conductor to the rear by locking the locking portion, and the air chamber is formed with the It is arranged only in a region of the bottom wall portion that corresponds to the main body portion in the front-rear direction and is forward of the retainer portion.

In the shield terminal of the present disclosure, an air chamber is formed in the wall portion that constitutes the conductor housing chamber, paying attention to the fact that air has a lower dielectric constant than synthetic resin. Thereby, even if the dielectric is made of a highly rigid material, the impedance can be matched. Therefore, the impedance can be increased without lowering the rigidity of the dielectric. In addition, in the area where the front end of the inner conductor is arranged, the mating conductor is inserted inside the main body, and the proportion of metal occupied is large, so there is concern that the impedance will be lower than in other areas. be done. On the other hand, in the shield terminal of the present disclosure, since the air chamber is arranged in the area corresponding to the main body, the impedance in the area where the front end of the inner conductor is arranged can be raised to the same extent as the other areas. can be done. Further, the air chamber can be disposed in a region corresponding to the main body portion after forming a retaining portion for retaining the inner conductor in the bottom wall portion.

(2) It is preferable that the retaining portion is formed at the rear end edge portion of the air chamber. According to this configuration, a large air chamber can be ensured without complicating the shape of the wall portion.

(3) The dielectric is configured by combining a first component having a front wall portion and a second component holding the inner conductor so as to sandwich the inner conductor between the first component and the front wall portion. The mating conductor is inserted into the insertion port of the first part, the material of the first part is a material or material having higher mechanical strength than the second part, and the second part is preferably a material having a dielectric constant lower than that of the first component. According to this configuration, since the material of the first part has higher mechanical strength than the material of the second part, even if the mating conductor interferes with the front wall, the mating conductor does not move from the front wall. There is no danger of piercing the part. Moreover, since the second component is made of a material with a low dielectric constant, the impedance can be increased.

[Details of the embodiment of the present disclosure]
[Example 1]
A first embodiment embodying the shield terminal of the present disclosure will be described with reference to FIGS. 1 to 10. FIG. The present invention is not limited to these exemplifications, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. In the first embodiment, regarding the front-rear direction, the left side in FIGS. 1 to 10 is defined as the front. Regarding the vertical direction, the directions appearing in FIGS. 3, 5 and 8 are defined as upward and downward as they are.

The shield connector 10 of the first embodiment is a connection member that constitutes a wire harness for an automotive Ethernet (registered trademark) high-speed communication circuit. and The shield terminal 12 is configured by assembling a terminal unit 13 and an outer conductor 14 . One terminal unit 13 is configured by housing a pair of inner conductors 15 in a dielectric 22 .

The inner conductor 15 has a shape elongated in the front-rear direction as a whole. A rectangular tube-shaped body portion 16 is formed at the front end portion of the inner conductor 15 . An elongated tab-shaped mating conductor 48 is inserted into the body portion 16 from the front of the inner conductor 15 . The mating conductor 48 inserted into the body portion 16 elastically contacts the elastic contact piece 17 formed in the body portion 16, whereby the mating conductor 48 and the inner conductor 15 are electrically connected. A stepped locking portion 18 is formed at the rear end portion of the body portion 16 . An open-barrel crimp portion 19 is formed at the rear end portion of the inner conductor 15, and the front end portion of the electric wire 20 is fixed to the crimp portion 19 so as to be conductive. A pair of wires 20 connected to two inner conductors 15 constitute a twisted pair wire 21 .

The dielectric 22 has a half-split synthetic resin first part 23 and a half-split synthetic resin second part 34 arranged vertically (intersecting the axis of the front end of the electric wire 20). direction). The material of the first part 23 is polybutylene terephthalate (PBT) having a mechanical strength higher than that of the second part 34, and the material of the second part 34 has a dielectric constant lower than that of the first part 23. Polypropylene (PP).

The first component 23 has a bottom wall portion 24 that is elongated in the front-rear direction, and a front wall portion 25 that rises upward from the front edge of the bottom wall portion 24 . A pair of left and right insertion openings 26 for inserting the mating conductor 48 of the mating conductor 48 are formed in the front wall portion 25 in a penetrating form. The first part 23 includes a central partition wall 27 rising upward from a laterally central position in the longitudinally central portion of the bottom wall portion 24 , and left and right side surfaces of the central partitioning wall 27 in the longitudinally central portion of the bottom wall portion 24 . A pair of left and right retainer portions 28 are formed so as to protrude upward in a region connected to the two. Further, a pair of left and right locking protrusions 29 are formed on the outer side surfaces of the pair of left and right retaining portions 28 .

The first part 23 includes a pair of left and right front side walls 30 rising upward from the front end portions of the left and right side edges of the bottom wall portion 24, and a front partition portion rising upward from the center position in the left-right direction of the front end portion of the bottom wall portion 24. 31 are formed. A pair of the front side wall 30 and the front partition 31 are connected to the rear surface of the front wall 25 . The first part 23 includes a pair of left and right rear side walls 32 rising upward from the rear end portions of the left and right side edges of the bottom wall portion 24, and a rear partition wall rising upward from the center position in the left-right direction of the rear end portion of the bottom wall portion 24. 33 are formed.

The second part 34 includes an upper wall portion 35 elongated in the front-rear direction, a pair of left and right side wall portions 36 extending downward from both left and right side edges of the upper wall portion 35, and a pair of left and right side wall portions 36 extending downward from the center position of the upper wall portion 35 in the left-right direction. A pair of extended front and rear partition walls 37 are provided. Stepped lock portions 38 (see FIG. 7) are formed on the inner side surfaces of the pair of side wall portions 36 .

When assembling the first part 23 and the second part 34 , the pair of inner conductors 15 are placed on the bottom wall portion 24 of the first part 23 . Since the first part 23 and the second part 34 are divided in a direction crossing the front end of the electric wire 20 at a substantially right angle and are united, the direction of movement when the inner conductor 15 is placed also coincides with the front end of the electric wire 20 . It is a direction that intersects the axis of the part at a substantially right angle. As a result, the untwisted length of the electric wires 20 can be kept as short as possible at the front ends of the two electric wires 20 that constitute the twisted pair wire 21, thereby reducing noise caused by untwisting the electric wires 20. can avoid a decline in

The pair of inner conductors 15 placed on the first component 23 can be prevented from being dislocated in the front-rear direction with respect to the first component 23 by individually locking the locking portions 18 of the main body portion 16 to the retaining portions 28 . Regulated. Further, the pair of inner conductors 15 are prevented from shifting in the left-right direction and tilting by sandwiching the front end of the main body 16 between the front side wall 30 and the front partition 31 . Further, the pair of inner conductors 15 are prevented from lateral displacement and inclination by sandwiching the rear ends of the crimping portions 19 between the rear side wall 32 and the rear partition wall 33 .

After the pair of inner conductors 15 are attached to the first part 23, the second part 34 is assembled with the first part 23 from above. The assembly direction of the part to the first part 23 is the direction that intersects the axis of the front end of the electric wire 20 at a substantially right angle. When the first part 23 and the second part 34 are combined, the dielectric 22 is formed, and the dielectric 22 is assembled with the pair of inner conductors 15 accommodated therein, and the assembly of the terminal unit 13 is completed. do.

The united first part 23 and second part 34 are held in the united state by engagement between the lock portion 38 and the lock projection 29 . In the combined state, the front side wall 30, the side wall 36, and the rear side wall 32 are arranged in series in the front-rear direction, and the front partition 31, the front partition wall 37, the central partition wall 27, and the rear partition wall. The part 37 and the rear partition wall 33 are arranged in series in the front-rear direction. Thereby, a pair of left and right conductor accommodating chambers 39 for individually accommodating the pair of inner conductors 15 are formed in the dielectric 22 .

The terminal unit 13 is surrounded by a rectangular tubular outer conductor 14 made of a metal material. The outer conductor 14 is configured by vertically uniting an upper shell and a lower shell. The shield terminal 12 is configured by surrounding the terminal unit 13 with the outer conductor 14 . A barrel portion 40 formed at the rear end portion of the outer conductor 14 is attached to the braided wire 41 of the twisted pair wire 21 so as to be able to contact therewith. The shield terminal 12 fixed to the twisted pair wire 21 is inserted into the housing 11 from behind and assembled.

Now, since the shield connector 10 and the shield terminal 12 of the first embodiment are used in a high-speed communication circuit, it is preferable to match the impedance in order to improve the reliability of communication performance. When the impedance of the shield terminal 12 is low, polypropylene, which has a low dielectric constant, is used as the material of the second part 34 of the dielectric 22 as a means for increasing the impedance. It cannot be said that it is desirable as a material that has the function of stably holding 15 .

Therefore, in order to increase the reliability of the function of holding the inner conductor 15, the material of the first part 23 is polybutylene terephthalate, which has a high mechanical strength. cause a decrease in Therefore, as means for increasing the impedance without lowering the rigidity of the dielectric 22, air chambers 42, 43, 45, and air chambers 42, 43, 45, 46 is formed.

Specifically, a pair of left and right front first air chambers 42 are formed at the front end portion of the bottom wall portion 24 , and a pair of left and right front air chambers 42 are formed near the rear of the pair of front first air chambers 42 in the bottom wall portion 24 . A rear first air chamber 43 is formed. Both of these first air chambers 42 and 43 communicate with the inside of the conductor accommodating chamber 39 and the outside (bottom surface) of the dielectric 22 . A region of the bottom wall portion 24 between the front first air chamber 42 and the rear first air chamber 43 functions as a reinforcing portion 44 .

Further, since the main body portion 16 of the inner conductor 15 has a rectangular tubular shape, it has a larger amount of metal than the crimping portion 19 having an open barrel shape. Moreover, inside the body portion 16, the mating conductor 48, which is a metal part, is inserted, and there is a locking portion 18 made of metal that elastically contacts the mating conductor 48. there is As described above, the formation region of the main body portion 16 has a high metal density, so that the impedance is lower than that of the region behind the main body portion 16 . Therefore, the rear end of the rear first air chamber 43 and the front end of the retainer portion 28 that locks onto the lock portion 18 are positioned adjacent to each other in the front-rear direction. That is, the front first air chamber 42 and the rear first air chamber 43 are arranged at positions corresponding to the body portion 16 of the inner conductor 15 in the front-rear direction.

A front second air chamber 45 is formed at the front end portion of the upper wall portion 35 of the second component 34 , and a pair of left and right air chambers 45 are provided near the rear of the pair of front second air chambers 45 in the upper wall portion 35 . A rear second air chamber 46 is formed. Both of these second air chambers 45 and 46 communicate with the inside of the conductor accommodating chamber 39 and the outside (bottom surface) of the dielectric 22 . The formation area of the front second air chamber 45 in the front-rear direction is substantially the same as the formation area of the front first air chamber 42 . The formation area of the rear second air chamber 46 in the front-rear direction is longer rearward than the formation area of the front first air chamber 42 . A region of the upper wall portion 35 between the front second air chamber 45 and the rear second air chamber 46 functions as a reinforcing portion 47 .

The shield terminal 12 of the first embodiment includes a synthetic resin dielectric 22 in which a pair of left and right conductor accommodating chambers 39 are formed, and a pair of left and right inner conductors 15 individually accommodated in the conductor accommodating chambers 39. , and an outer conductor 14 surrounding the dielectric 22 . The dielectric 22 has a bottom wall portion 24 that defines a conductor accommodating chamber 39 with a front first air chamber 42 and a rear first air chamber 43 formed therein. Similarly, the dielectric 22 has an upper wall portion 35 in which a front-side second air chamber 45 and a rear-side second air chamber 46 are formed and which constitutes a conductor accommodation chamber 39 .

Polybutylene terephthalate, which is the material of the first part 23 constituting the dielectric 22 of the present embodiment 1, has relatively high mechanical rigidity, but on the other hand, it has a low dielectric constant, resulting in a low impedance. is concerned. Therefore, we paid attention to the fact that the dielectric constant of air is lower than that of the synthetic resin that is the material of the dielectric 22 (the first part 23 and the second part 34). Air chambers 42 , 43 , 45 and 46 are formed in the wall portion 24 and the upper wall portion 35 . By forming the air chambers 42, 43, 45, and 46 with a low dielectric constant, it is possible to increase the impedance and improve the reliability of communication performance.

At the front end of the inner conductor 15, there is formed a rectangular tube-shaped main body 16 into which the mating conductor 48 is inserted so as to be conductive. In the region where the front end portion of the inner conductor 15 is arranged, the mating conductor 48 is inserted inside the body portion 16, and the proportion of metal occupied is large, so the impedance can be lower than in other regions. Concerned. Therefore, the air chambers 42, 43, 45, and 46 are arranged in regions corresponding to the body portion 16 in the front-rear direction. According to this configuration, the impedance of the region where the front end portion of the inner conductor 15 is arranged can be increased to the same extent as other regions.

An engaging portion 18 is formed at the rear end of the main body portion 16 , and by engaging the engaging portion 18 with the bottom wall portion 24 of the conductor housing chamber 39 , the inner conductor 15 is connected to the first component 23 . A retaining portion 28 is formed to restrict relative displacement rearward with respect to the . The front first air chamber 42 and the rear first air chamber 43 of the bottom wall portion 24 are arranged only in a region of the bottom wall portion 24 in front of the retaining portion 28 . According to this configuration, the retaining portion 28 for retaining the inner conductor 15 is formed in the bottom wall portion 24, and the air chamber can be arranged in the area corresponding to the main body portion 16. FIG. Further, since the retaining portion 28 is formed at the rear edge portion of the rear first air chamber 43, the front first air chamber 42 and the rear first air chamber 42 can be separated from each other without complicating the shape of the bottom wall portion 24. 1 Large air chamber 43 can be ensured.

In addition, the dielectric 22 is configured by combining a first part 23 having a front wall portion 25 and a second part 34 holding the inner conductor 15 so as to sandwich the inner conductor 15 between the first part 23 and the first part 23. A mating conductor 48 is inserted into the insertion opening 26 of the front wall portion 25 . The material of the first part 23 is polybutylene terephthalate, which has higher mechanical strength than that of the second part 34 , and the material of the second part 34 has a dielectric constant higher than that of the first part 23 . Polypropylene, which is a low material or material, was used. You can According to this configuration, the first part 23 is made of a material having higher mechanical strength than the second part 34, so even if the mating conductor 48 interferes with the front wall part 25, the mating conductor There is no danger that the side conductor 48 will stick into the front wall portion 25 . Moreover, since the second component 34 is made of a material with a low dielectric constant, the impedance can be increased.

[Other embodiments]
The invention is not limited to the embodiments illustrated by the above description and drawings, but is indicated by the claims. The present invention includes all modifications within the meaning and equivalents of the claims and the scope of the claims, and is intended to include the following embodiments.
(1) In Embodiment 1, the air chambers are formed only on the bottom and top walls of the dielectric, but the air chambers may be formed on the side walls (side surfaces of the dielectric).
(2) In Example 1, the air chamber penetrates from the inner surface to the outer surface of the dielectric. It may be in the form of
(3) Although two inner conductors are accommodated in one dielectric in the first embodiment, the number of inner conductors accommodated in one dielectric may be one or three or more.
(4) In Example 1, the dielectric is composed of two parts, the first part and the second part, but the dielectric may be a single part.
(5) In the first embodiment, two electric wires connected to a pair of inner conductors constitute a twisted pair wire. Applicable.
(6) In the first embodiment, the material of the first part is polybutylene terephthalate (PBT), but the material of the first part may be other than polybutylene terephthalate.
(7) In the first embodiment, the material of the second part is polypropylene (PP), but the material of the second part is polyethylene (PE), polystyrene (PS), expanded polybutylene terephthalate, or the like. There may be.
(8) In Example 1 above, the material or combination of materials for the first and second parts is polybutylene terephthalate and polypropylene, but the material or combination of materials for the first and second parts is polybutylene. Terephthalate and polyethylene (PE) may be used, or polybutylene terephthalate and foamed polybutylene terephthalate may be used.

DESCRIPTION OF SYMBOLS 10... Shield connector 11... Housing 12... Shield terminal 13... Terminal unit 14... Outer conductor 15... Inner conductor 16... Body part 17... Elastic contact piece 18... Locking part 19... Crimp part 20... Electric wire 21... Twisted pair wire 22... Dielectric 23 First component 24 Bottom wall (wall)
25 Front wall portion 26 Insertion opening 27 Central partition wall 28 Retaining portion 29 Lock projection 30 Front side wall 31 Front partition portion 32 Rear side wall 33 Rear partition wall 34 Second component 35 Upper wall (wall)
36... Side wall part 37... Partition part 38... Lock part 39... Conductor housing chamber 40... Barrel part 41... Braided wire 42... Front first air chamber (air chamber)
43 Rear first air chamber (air chamber)
44 Reinforcing part 45 Front second air chamber (air chamber)
46 Rear second air chamber (air chamber)
47 Reinforcing portion 48 Mating conductor

Claims (2)

a dielectric made of synthetic resin in which a conductor housing chamber is formed;
an inner conductor housed in the conductor housing chamber;
an outer conductor surrounding the dielectric;
a bottom wall portion forming the conductor housing chamber and formed with two air chambers arranged in front and back ;
A square tube-shaped main body portion into which the mating conductor is electrically connected is formed at the front end portion of the inner conductor,
A locking portion having a stepped shape is formed at the rear end of the main body,
The bottom wall portion of the conductor housing chamber is provided with a retaining portion that restricts relative displacement of the inner conductor to the rear by engaging the locking portion,
The two air chambers arranged in the front-rear direction are arranged only in a region of the bottom wall portion corresponding to the main body portion in the front-rear direction and in front of the retaining portion,
The retaining portion is formed at a rear edge portion of the air chamber on the rear side ,
A shield terminal in which a rear end of the air chamber on the rear side and a front end of the retaining portion are adjacent to each other in the front-rear direction. 2. The shield terminal according to claim 1 , wherein the air chamber communicates with the inside of the conductor accommodating chamber and the outside of the dielectric, and opens at the bottom surface of the dielectric .

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