JP2020013803A - Shield terminal - Google Patents

Abstract

To improve impedance without degrading the rigidity of a dielectric.SOLUTION: A shield terminal 12 comprises: an inner conductor 14 provided with a tab 16 protruding forward from a body part 15; a dielectric 21 which has a conductor housing chamber 36 inside and holds the inner conductor 14 with the body part 15 housed inside the conductor housing chamber 36; an outer conductor 37 surrounding the dielectric 21 and the tab 16; and wall parts 23, 31, and 32 which constitute a conductor housing chamber 36 and on which air chambers 43 to 50 are formed. Focusing on the fact that air has a dielectric constant lower than that of synthetic resin, the air chambers 43 to 50 are formed on the wall parts 23, 31, and 32 constituting the conductor housing chamber 36. Thus, impedance can be improved even if a material with high rigidity is used as the dielectric 21.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shield terminal.

  Patent Literature 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 this kind of shield terminal is used in a high-speed communication circuit, it is preferable to match impedances in order to increase the reliability of communication performance.

JP 2012-129103 A

  When the impedance is low, as a means for increasing the impedance, a material having a low dielectric constant, for example, polypropylene may be used as the dielectric material. However, since polypropylene has low rigidity, it cannot be said that polypropylene is desirable as a material having a function of stably holding the inner conductor terminal.

  The present invention has been completed based on the above circumstances, and has as its object to increase impedance without reducing rigidity of a dielectric.

The shield terminal of the present invention,
An inner conductor with a tab protruding forward from the main body,
A conductor accommodating chamber is formed therein, and a dielectric that holds the inner conductor in a state where the main body is accommodated in the conductor accommodating chamber,
An outer conductor surrounding the dielectric and the tab,
It is characterized in that the conductor accommodating chamber is provided and includes a wall portion in which an air chamber is formed.

  Focusing on the fact that air has a lower dielectric constant than synthetic resin, an air chamber was formed in the wall constituting the conductor accommodating chamber. Thereby, the impedance can be increased even if the dielectric is made of a material having high rigidity.

Sectional view showing a state where the shield terminal of the first embodiment is attached to a housing. Cross section of shield terminal XX sectional view of FIG. FIG. 2 is a sectional view taken along line YY of FIG. 2. FIG. 2 is a sectional view taken along line ZZ of FIG. 2. Top view of shield terminal Plan view showing a state where an inner conductor is attached to the first component Perspective view of first component Perspective view of the first part in an upside down state Perspective view of the second part Perspective view of the second component turned upside down. Perspective view of first shell constituting outer conductor Perspective view of the second shell constituting the outer conductor

  In the present invention, the dielectric may hold a first component having a groove that forms the conductor accommodating chamber and the inner conductor attached to the groove so as to sandwich the inner conductor between the first component and the first component. The two parts are united, and the lock part formed on the side surface of the first part and the side part of the second part is locked together to be held in a united state. It may be formed on at least one of the bottom wall of the first component and the upper wall of the second component. Since the bottom wall portion and the upper wall portion are regions where the lock portions are not formed, the degree of design freedom when setting the formation position of the air chamber is high.

  In the present invention, the dielectric may include a first component having a groove that forms the conductor accommodating chamber formed by raising a partition from a bottom wall, and a second component having an upper wall that covers the groove. And the material or material of the first component is a material or material having a lower dielectric constant than the second component, and the material or material of the second component is more mechanically stronger than the first component. High material or material. According to this configuration, the first component is made of a material or a material having lower mechanical strength than the second component. However, the volume is large by the presence of the partition, so that the strength is increased as a whole. Further, the first component having a large volume has a low dielectric constant, so that the impedance can be effectively increased.

  In the present invention, the second component may be formed with a side plate that maintains a united state by being locked to an outer surface of a side wall of the first component, and the air chamber may be formed in the side plate. . Since the second component is made of a material having a higher mechanical strength than the first component, the strength is maintained even if the side plate portion forms an air chamber.

<Example 1>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the following description, the front and rear directions in FIGS. 1, 2, 6, 7, 8, and 10 are defined as the front. As for the up and down direction, the directions appearing in FIGS. 8 and 10 are defined as up and down as they are, and the inverted directions in FIGS. 1 to 5 are defined as up and down.

  The shield connector 10 according to the first embodiment is a connection member that constitutes a wire harness for an Ethernet (registered trademark) high-speed communication circuit of an automobile, and includes a housing 11 made of a synthetic resin and a shield terminal 12 housed in the housing 11. It is comprised including. The shield terminal 12 is configured by assembling the terminal unit 13 and the outer conductor 37. One terminal unit 13 is configured by attaching a pair of inner conductors 14 to a dielectric 21.

  The inner conductor 14 has an elongated shape in the front-rear direction as a whole. The inner conductor 14 has a rectangular cylindrical main body 15, a tab 16 protruding elongated from the main body 15, and an open barrel-shaped crimping part 17 connected to the rear end of the main body 15. At the rear end of the main body 15, a stepped locking portion 18 is formed. The front end of the electric wire 19 is fixed to the crimping portion 17 in a conductive manner. A pair of electric wires 19 connected to the two inner conductors 14 constitute a twisted pair wire 20.

  The dielectric body 21 intersects the first part 22 made of a synthetic resin in a half-shape and the second part 30 made of a synthetic resin in a half-shape in the vertical direction (intersecting with the axis of the front end of the electric wire 19). Direction). The material and material of the first component 22 are polypropylene (PP) having a lower dielectric constant than the second component 30, and the material and material of the second component 30 are polybutylene having higher mechanical strength than the first component 22. Terephthalate (PBT).

  The first component 22 includes a bottom wall portion 23 (e.g., a wall portion described in the claims) that is elongated in the front-rear direction, a pair of left and right side wall portions 24 that rise upward from left and right side edges of the bottom wall portion 23, and a bottom wall portion 23. And a partition wall 25 rising from the center in the left-right direction. An area defined by the bottom wall 23, the side wall 24, and the partition 25 is a groove 26 which is elongated in the front-rear direction. The bottom wall 23 is formed with a pair of left and right protrusion-shaped retaining portions 27 facing the left and right grooves 26. A sliding protrusion 28 is formed at a position near the front end of the upper edge of the left and right side wall portions 24. Lock grooves 29 (lock portions described in claims) extending in the front-rear direction are formed on the outer side surfaces of the left and right side wall portions 24.

  The second component 30 includes an upper wall portion 31 (e.g., a wall portion described in the claims) which is elongated in the front-rear direction, and a pair of left and right side plate portions 32 extending downward from left and right side edges of the upper wall portion 31 (described in the claims). Wall). A pair of guide grooves 33 which are elongated in the front-rear direction are formed on both left and right side edges of the upper wall portion 31. The guide groove 33 communicates from the outer surface of the upper wall portion 31 to the inner surface.

  The pair of side plate portions 32 are formed with lock ribs 34 (lock portions according to the claims) that extend in the front-rear direction and protrude from the extended end edge of the inner surface. In addition, the left and right side plate portions 32 are formed with cutout portions 35 in a form in which a region of the side plate portion 32 excluding the front and rear end edges and the extended end edge is cut out. The notch 35 communicates with the inner surface of the outer conductor 37 of the side plate 32.

  When assembling the first component 22 and the second component 30, the main body portion 15 and the crimping portion 17 of the pair of inner conductors 14 are individually placed in the pair of groove portions 26 of the first component 22. Since the first part 22 and the second part 30 are divided and united in a direction that intersects the front end of the electric wire 19 at a substantially right angle, the moving direction when the inner conductor 14 is placed is also the front end of the electric wire 19. This is a direction that intersects the axis of the portion at a substantially right angle. Accordingly, at the front ends of the two electric wires 19 constituting the twisted pair wire 20, the length of untwisting of the electric wire 19 can be suppressed as short as possible, so that the noise reduction function caused by untwisting of the electric wire 19 is achieved. Can be avoided.

  The pair of inner conductors 14 mounted on the first component 22 is capable of locking the locking portions 18 of the main body 15 individually to the retaining portions 27, so that the positional deviation in the front-rear direction with respect to the first component 22 is reduced. Be regulated. After attaching the pair of inner conductors 14 to the first component 22, the second component 30 is assembled to the first component 22 from above. The direction in which the second component 30 is attached to the first component 22 is a direction that intersects the axis of the front end of the electric wire 19 substantially at right angles.

  When the first component 22 and the second component 30 are combined, the dielectric 21 is formed, and the combined first component 22 and the second component 30 are held in a combined state by the locking of the lock groove 29 and the lock rib 34. Is done. In the combined state, a pair of left and right conductor housing chambers 36 for housing the main body 15 and the crimping portion 17 of the pair of inner conductors 14 are formed in the dielectric 21. By the above. The assembly of the terminal unit 13 is completed.

  Further, the second component 30 slides the guide groove 33 and the guide rib to cover and protect the tab 16 (not shown), and an exposed position for exposing the tab 16 (FIGS. 1, 2, 6, and 6). ). In addition, the second protrusion 30 is held at the protection position by locking the sliding protrusion 28 to the rear end of the guide groove 33 in a semi-lock state. In addition, the second protrusion 30 is held at the exposed position by the slide protrusion 28 being locked in a semi-lock state with the front end of the guide groove 33.

  The terminal unit 13 is surrounded by a rectangular tubular outer conductor 37 made of a metal material. The outer conductor 37 is configured by combining a first shell 38 (see FIG. 12) and a second shell 39 (see FIG. 13). By surrounding the terminal unit 13 with the outer conductor 37, the shield terminal 12 is configured. A barrel portion 40 formed at the rear end of the outer conductor 37 is conductively fixed to the braided wire 41 of the twisted pair wire 20. The shield terminal 12 fixed to the twisted pair wire 20 is assembled by being inserted into the housing 11 from behind.

  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 impedances in order to enhance reliability of communication performance. When the impedance is low, as a means for increasing the impedance, the material of the first component 22 of the dielectric 21 is made of polypropylene having a low dielectric constant. However, since the mechanical rigidity of polypropylene is low, the terminal of the inner conductor 14 is stabilized. This is not desirable as a material having a function of holding the same.

  Therefore, in order to increase the reliability of the function of holding the inner conductor 14, the material of the second component 30 is made of polybutylene terephthalate having high mechanical strength. However, since polybutylene terephthalate has a high dielectric constant, impedance Cause a decrease. Therefore, air chambers 43 to 48 are formed in the bottom wall portion 23 and the upper wall portion 31 of the dielectric material 21 as a means for increasing the impedance without reducing the rigidity of the dielectric material 21. ing.

  Specifically, a pair of left and right front first air chambers 43 (the air chambers described in the claims) are formed at the front end of the bottom wall 23, and a pair of front first air chambers 43 in the bottom wall 23. A pair of left and right center first air chambers 44 (the air chambers described in the claims) are formed in the vicinity of the rear of the left and right sides of the pair of center first air chambers 44 in the bottom wall 23. A pair of rear first air chambers 45 (air chambers described in claims) are formed. Each of these first air chambers 43, 44, 45 communicates with the inside of the conductor housing chamber 36 and the outside (bottom surface) of the dielectric 21.

  A region between the front first air chamber 43 and the rear first air chamber 45 in the bottom wall portion 23 has a function as a reinforcing portion. The pair of left and right front first air chambers 43 communicate with each other on the outer surface of the bottom wall 23 to form one space. The pair of left and right central first air chambers 44 communicate with each other on the outer surface of the bottom wall 23 to form one space. The pair of left and right rear first air chambers 45 communicate with each other on the outer surface of the bottom wall 23 to form one space.

  Further, a front second air chamber 46 (an air chamber described in the claims) is formed at the front end of the upper wall 31 of the second component 30, and a pair of front second air chambers 46 in the upper wall 31 is formed. A pair of left and right central second air chambers 47 (air chambers according to the claims) are formed in the vicinity of the rear, and a pair of left and right central second air chambers 47 in the upper wall portion 31 is located in the vicinity of the rear of the pair of center second air chambers 47. A second rear air chamber 48 (an air chamber described in claims) is formed. Each of the second air chambers 46, 47, and 48 communicates with the inside of the conductor housing chamber 36 and the outside (bottom surface) of the dielectric 21.

  The region where the front second air chamber 46 is formed in the front-rear direction is substantially the same as the region where the front first air chamber 43 is formed. The formation region of the central second air chamber 47 in the front-rear direction is substantially the same as the formation region of the central first air chamber 44. The formation region of the rear second air chamber 48 in the front-rear direction is substantially the same as the formation region of the rear first air chamber 45. A region of the upper wall portion 31 between the front second air chamber 46 and the rear second air chamber 48 has a function as a reinforcing portion. Further, the pair of left and right guide grooves 33 formed in the upper wall portion 31 function as side air chambers 49 (an air chamber described in the claims). The pair of notches 35 formed in the left and right side plate portions 32 function as side air chambers 50 (the air chambers described in the claims).

  The shield terminal 12 according to the first embodiment includes a pair of inner conductors 14 having tabs 16 protruding forward from the main body 15 and a conductor accommodating chamber 36 formed therein. The main body 15 is accommodated in the conductor accommodating chamber 36. The dielectric 21 that holds the inner conductor 14 in the assembled state, the outer conductor 37 that surrounds the dielectric 21 and the tab 16, the conductor housing chamber 36, and the bottom wall 23 in which the air chambers 43 to 45 are formed. , An upper wall portion 31 in which the air chambers 46 to 49 are formed, and a side plate portion 32 in which the air chamber 50 is formed.

  Polybutylene terephthalate, which is the material of the second component 30 constituting the dielectric 21 of the first embodiment, has relatively high mechanical rigidity, but has a low dielectric constant, and therefore has a low impedance. Is concerned. Therefore, attention is paid to the fact that the dielectric constant of air is lower than that of the synthetic resin that is the material of the dielectric 21 (the first component 22 and the second component 30). Air chambers 43 to 50 were formed in the wall 23, the upper wall 31, and the side plate 32. Since the air chambers 43 to 50 having a low dielectric constant are formed, even if a material having high rigidity is used for the dielectric 21, it is realized that the impedance is increased and the reliability of the communication performance is enhanced.

  Further, the dielectric 21 holds the first component 22 in which the groove 26 forming the conductor accommodating chamber 36 is formed, and holds the inner conductor 14 attached to the groove 26 so as to be sandwiched between the first component 22. It is configured by combining two parts 30. By locking the lock groove 29 formed on the outer surface of the first component 22 and the lock rib 34 formed on the inner surface of the second component 30, the first component 22 and the second component 30 are held in a united state. ing. The air chambers 43 to 48 are formed in the bottom wall 23 of the first component 22 and the upper wall 31 of the second component 30, and the bottom wall 23 and the upper wall 31 are Since it is a region where the lock ribs 34 and the lock ribs 34 are not formed, the degree of design freedom when setting the formation positions of the air chambers 43 to 48 is high.

  In addition, the dielectric 21 has a first component 22 in which a groove 26 forming a conductor accommodating chamber 36 is formed by rising the partition 25 from the bottom wall 23, and an upper wall 31 that covers the groove 26. It is configured by combining two parts 30. The material or material of the first component 22 is polypropylene having a lower dielectric constant than the second component 30, and the material or material of the second component 30 is polybutylene terephthalate having higher mechanical strength than the first component 22. . According to this configuration, the first component 22 is made of a material or a material having lower mechanical strength than the second component 30, but the volume is large by the presence of the partition wall portion 25, so that the overall strength is increased. ing. Further, since the first component 22 having a large volume has a low dielectric constant, the impedance can be effectively increased.

  Further, the second part 30 is formed with a side plate part 32 that is kept in a united state by being locked to the outer surface of the side wall part 24 of the first part 22, and a side air chamber 50 (a notch part 35) is formed in the side plate part 32. Is formed. Since the second component 30 is made of a material having a higher mechanical strength than the first component 22, the strength of the side plate portion 32 is maintained even if the side air chamber 50 is formed.

  The inner conductor 14 has a tab 16 protruding forward from the dielectric 21, and the dielectric 21 rises from the bottom wall 23 to the partition 25 to form the groove 26 forming the conductor accommodating chamber 36. The first component 22 formed is combined with a second component 30 that holds the inner conductor 14 attached to the groove 26 so as to be sandwiched between the first component 22 and the second component 30.

  The first part 22 is formed with a sliding protrusion 28, the second part 30 is formed with a guide groove 33 functioning as a side air chamber 49, and the second part 30 is formed with the sliding protrusion 28 in the guide groove 33. Are slidable back and forth between a protection position for covering the tab 16 and a regular assembly position for exposing the tab 16. According to this configuration, the guide groove 33 also has a function of increasing the impedance as the side air chamber 49. In addition, the guide groove 33 does not need to be formed in the first component 22 having relatively low strength.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the first embodiment, the air chamber of the first component is formed only on the bottom wall, but the air chamber may be formed on the side surface of the first component.
(2) In the first embodiment, the air chamber of the second component is formed on the upper wall and the side surface. However, the air chamber of the second component may be formed only on the upper wall.
(3) In the first embodiment, the air chamber is formed in the bottom wall, the upper wall, and the side plate of the dielectric. However, the air chamber is only one of the bottom wall, the upper wall, and the side plate. Alternatively, only two of them may be formed.
(4) In the first embodiment, the retaining portion is formed at the rear end edge of the air chamber. However, the retaining portion may be provided at a position behind the rear end of the air chamber.
(5) In the first embodiment, the air chamber penetrates from the inner surface of the dielectric to the outer surface. May be used.
(6) In the first embodiment, two inner conductors are attached to one dielectric, but the number of inner conductors accommodated in one dielectric may be one or three or more.
(7) In the first embodiment, the dielectric is composed of two parts, the first part and the second part. However, the dielectric may be a single part.
(8) In the first embodiment, the two electric wires connected to the pair of inner conductors constitute a twisted pair wire. However, the present invention is also applicable to a case where the electric wire connected to the inner conductor does not constitute a twisted pair wire. Applicable.
(9) In the first embodiment, the material and material of the second component are polybutylene terephthalate (PBT). However, the material and material of the second component may be other than polybutylene terephthalate.
(10) In the first embodiment, the material and material of the first component are polypropylene (PP). However, the material and material of the first component are polyethylene (PE), polystyrene (PS), foamed polybutylene terephthalate, and the like. There may be.
(11) In the first embodiment, the combination of the material or the material of the first part and the second part is polypropylene and polybutylene terephthalate, but the combination of the material or the material of the first part and the second part is polyethylene ( PE) and polybutylene terephthalate, or foamed polybutylene terephthalate and polybutylene terephthalate.

DESCRIPTION OF SYMBOLS 12 ... Shield terminal 14 ... Inner conductor 15 ... Main body 16 ... Tab 21 ... Dielectric 22 ... First part 23 ... Bottom wall (wall)
24 ... side wall part 26 ... groove part 29 ... lock groove (lock part)
30: second part 31: upper wall (wall)
32: Side plate (wall)
34 ... lock rib (lock part)
36: conductor accommodating chamber 37: outer conductor 43: front first air chamber (air chamber)
44 ... Central first air chamber (air chamber)
45 ... rear first air chamber (air chamber)
46 front second air chamber (air chamber)
47: Central second air chamber (air chamber)
48 Rear second air chamber (air chamber)
49 Side air chamber (air chamber)
50: Side air chamber (air chamber)

Claims (4)

An inner conductor with a tab protruding forward from the main body,
A conductor accommodating chamber is formed therein, and a dielectric that holds the inner conductor in a state where the main body is accommodated in the conductor accommodating chamber,
An outer conductor surrounding the dielectric and the tab,
A shield terminal, comprising: the conductor accommodating chamber; and a wall having an air chamber formed therein. The dielectric includes a first component having a groove that forms the conductor accommodating chamber, and a second component that holds the inner conductor attached to the groove so as to be sandwiched between the first component and the first component. It is configured to be united, and is held in a united state by locking lock portions formed on the side surface of the first component and the side surface of the second component,
The shield terminal according to claim 1, wherein the air chamber is formed in at least one of the bottom wall of the first component and the upper wall of the second component. The dielectric is formed by combining a first component having a groove that forms the conductor accommodating chamber by raising a partition from a bottom wall and a second component having an upper wall that covers the groove. Composed,
The material or material of the first component is a material or material having a lower dielectric constant than the second component,
3. The shield terminal according to claim 1, wherein a material or a material of the second component is a material or a material having higher mechanical strength than the first component. A side plate portion is formed on the second component to maintain a united state by being locked to an outer surface of a side wall portion of the first component,
The shield terminal according to claim 3, wherein the air chamber is formed in the side plate portion.

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