JP2010177127A - Shielded connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shielded connector capable of attaining characteristic impedance matching with a shielded cable, by lowering the characteristic impedance, using a signal conductor at a connecting position. <P>SOLUTION: In the shielded connector, in which an insulator Wb is interposed between a signal conductor Wa and a shielded conductor Wc and a terminal part of a shielded cable W formed and coated by an insulating sheath Wd, is connected to the outer periphery of the shielded conductor Wc, and there are provided an inner conductor terminal 2, having a signal conductor connection part 3 with which the signal conductor Wa is connected, an inner conductor terminal 2 with the signal conductor Wa connected; and an outer conductor terminal which houses the inner conductor terminal, while a dielectric is interposed and connects to the shielded conductor Wc. The terminal portion of the signal conductor Wa is bent back, at an end portion of the signal conductor connecting part 3, and the bent-back portion is pinched between the signal conductor connecting part 3 and a connection part crimping piece 9, made of a conductive sheet material which is mounted on the outer periphery of the signal conductor connecting part 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shield connector, and more particularly to a shield connector for electrically connecting shielded cables whose signal conductors are electromagnetically shielded by shield conductors.

  In recent years, electrical signals transmitted to printed circuit boards for control mounted with electronic components and ICs (integrated circuits) incorporated in electrical devices of automobiles such as car navigation systems have been accelerated (increased in frequency). Circuit patterns formed on the printed circuit board are also densely packed and densified. Generally, a shielded cable is used to transmit such a high-frequency electrical signal. However, as the transmitted electrical signal is further increased in frequency, the shielded connector connected to the shielded cable is further increased. There is a growing demand for higher frequencies.

  An example of a shielded cable is what is called a coaxial cable. Commonly used coaxial cables are a signal conductor that bundles a plurality of strands such as copper wires as a transmission path for electrical signals, a shield conductor that consists of a braided wire knitted with a plurality of strands, and these An insulator interposed between conductors and an insulating sheath covering the outer periphery of the shield conductor are coaxially arranged, and the shield conductor covers the outer periphery of the signal conductor without gaps. Is electromagnetically shielded.

  Usually, a shield connector connected to a terminal portion of a coaxial cable that transmits such a high-frequency signal is connected to an inner conductor terminal that is connected to a signal conductor that transmits the high-frequency signal and a shield conductor such as a braided wire. Both are provided with an outer conductor terminal covering the outer periphery of the inner conductor terminal, and a dielectric having a predetermined relative dielectric constant interposed between the inner conductor terminal and the outer conductor terminal, and insulates the end portion of the coaxial cable. The inner conductor terminal and the outer conductor terminal are connected to the signal conductor and the shield conductor exposed by peeling off the body and the sheath, respectively.

  An example of such a shield connector is disclosed in Patent Document 1 below. FIG. 6 shows a longitudinal section of the shield connector. As shown in the figure, the shield connector 50 is connected to a portion where the insulator Wb and the sheath Wd of the coaxial cable W are peeled off and the signal conductor Wa and the shield conductor Wc are exposed. The inner conductor terminal 51 is connected to the signal conductor Wa via the crimping portion 51a, and the outer conductor terminal 53 is connected to the shield conductor Wc via the crimping portion 53a. A dielectric 52 that insulates both the terminals is provided. It is provided between both terminals.

  In general, the characteristic impedance of a coaxial cable in high-frequency signal transmission is set to, for example, 50Ω, and matching (matching) with the characteristic impedance of a circuit board or the like of an electric device to be connected is achieved. If there is a portion (non-matching portion) where the characteristic impedance is not matched in the transmission path of the high-frequency signal, problems such as a decrease in transmission efficiency due to signal reflection at the mismatching portion and generation of noise occur. Therefore, the characteristic impedance of the shield connector needs to be matched with the characteristic impedance of the coaxial cable.

  Normally, the characteristic impedance of the shield connector is adjusted by adjusting the ratio of the inner diameter of the shell of the outer conductor terminal to the outer diameter of the terminal of the inner conductor terminal and the relative dielectric constant of the dielectric so that impedance matching with the coaxial cable can be achieved. As shown in FIG. 6, the outer diameter of the crimping portion 51 a after crimping the inner conductor terminal 51 has a size and shape giving priority to the reliability of electrical connection with the signal conductor Wa. In general, since the outer diameter of the terminal portion 51b is smaller than the outer diameter of the terminal portion 51b, the “ratio of the inner diameter of the shell portion 53b of the outer conductor terminal 53 and the outer diameter of the crimp portion 51a of the inner conductor terminal 51” in the crimp portion 51a The “ratio between the inner diameter of the shell portion 53b of the outer conductor terminal 53 and the outer diameter of the terminal portion 51b of the inner conductor terminal 51” in 51b is not the same. For this reason, the characteristic impedance in the crimping part 51 a of the inner conductor terminal 51 is not matched with the characteristic impedance of the coaxial cable W, and becomes higher than the characteristic impedance of the coaxial cable W.

  When the characteristic impedance of such a shielded connector is not equal to that of a coaxial cable, the transmitted electrical signal is reflected or radiated, causing problems such as the signal not being transmitted correctly or causing noise. It occurs. In particular, this tendency becomes significant in the transmission of high-frequency signals of several GHz.

  In order to improve this, the characteristic impedance at the position of the crimping portion of the inner conductor body terminal should be lowered so as to match the characteristic impedance of the coaxial cable. Impedance matching can be achieved by increasing the diameter to about the outer diameter of the terminal portion. Conventionally, as a method of increasing the outer diameter of the crimping portion, a method of attaching a cylindrical metal sleeve to the crimping portion has been adopted.

JP 2000-173725 A

  However, the method in which a cylindrical metal sleeve is attached to the crimping portion to increase the outer diameter of the crimping portion is an insulator in which the metal sleeve is previously stripped from the coaxial cable before crimping the crimping portion of the inner conductor terminal. The assembly work becomes complicated because it must be passed through. Further, since a metal sleeve is required separately from the shield connector, the material cost increases. Therefore, there is a problem that the manufacturing cost of the shield connector increases.

  The problem to be solved by the present invention is to reduce the characteristic impedance that becomes high at the position of the connection portion between the inner conductor terminal of the shield connector and the signal conductor of the shield cable, and to achieve characteristic impedance matching with the shield cable. It is also intended to reduce the manufacturing cost of such a shielded connector.

  In order to solve the above-described problems, the present invention is configured such that an insulator is interposed between a signal conductor and a shield conductor, and an end portion of a shielded cable in which an outer sheath is covered with an insulating sheath is connected. In the shield connector, an inner conductor terminal having a signal conductor connection portion to which the signal conductor is connected, and an outer conductor terminal that accommodates the inner conductor terminal with a dielectric interposed therebetween and to which the shield conductor is connected. A terminal portion of the signal conductor is folded at an end portion of the signal conductor connection portion, and the folded portion is a connection portion made of a conductive plate material attached to the signal conductor connection portion and an outer periphery of the signal conductor connection portion. The gist is that it is sandwiched between the crimping piece.

  In this case, it is preferable that the length of the signal conductor folded at the end of the signal conductor connection portion is equal to or greater than the length of the signal conductor connection portion.

  According to the present invention, on the outer periphery of the signal conductor connection portion of the inner conductor terminal connected to the signal conductor, the connection portion crimping piece made of a conductive plate material is crimped, and at that time, the signal conductor connection portion and The signal conductor folded back at the end of the signal conductor connecting portion is sandwiched between the connecting portion crimping pieces. That is, in addition to the connection part crimping piece that is crimped to the outer peripheral surface of the signal conductor connection part, the signal conductor connection part and the vicinity of the signal conductor connection part are enlarged by the signal conductor sandwiched between the signal conductor connection part and the connection part crimping piece. Therefore, the high impedance in the vicinity of the signal conductor connecting portion, which has a smaller diameter than the terminal portion of the inner conductor terminal, can be reduced, and impedance mismatch with the shielded cable can be eliminated.

  Further, since the signal conductor folded back at the end of the signal conductor connection portion is sandwiched between the signal conductor connection portion and the connection portion crimping piece, the connection strength of the signal conductor (shield cable) to the shield connector is improved. Further, the contact area between the signal conductor and the inner conductor terminal is increased, and a stable electrical connection state between them can be obtained.

  Furthermore, since the connection portion crimping piece is only crimped to the outer periphery of the signal conductor connecting portion with the folded signal conductor interposed therebetween, as in the case of processing to increase the diameter of the signal conductor connecting portion by a conventional metal sleeve. In addition, it is not necessary to pass the metal sleeve over the insulator from which the shield cable is exposed in advance, and the workability of increasing the diameter of the signal conductor connecting portion is improved. Further, since the folded signal conductor is used, a new member for increasing the diameter of the signal conductor connection portion is not required, leading to a reduction in manufacturing cost.

  In this case, the length of the signal conductor folded back at the end of the signal conductor connecting portion, that is, the length of the signal conductor sandwiched between the signal conductor connecting portion and the connecting portion crimping piece is the length of the signal conductor connecting portion. If it is equal to or greater than that, in the direction in which the signal conductor is folded back, there is a portion where the signal conductor is sandwiched between the signal conductor connecting portion and the connection portion crimping piece, and a portion where the signal conductor is not sandwiched. It is prevented that the connecting portion crimping piece is inclined and crimped, or a part of the connecting portion crimping piece is crushed during crimping. Further, the reliability of the connection state of the signal conductor (shield cable) to the shield connector and the electrical connection state of the signal conductor and the inner conductor terminal is further improved.

It is a longitudinal cross-sectional view of the shield connector which concerns on one Embodiment of this invention. FIG. 2 shows a procedure for connecting a signal conductor of a coaxial cable to a crimping part of the shield connector shown in FIG. 1 by crimping, (a) is a cross-sectional view of the crimping part and the signal conductor before crimping, and (b). Is a cross-sectional view of the crimping part and the signal conductor after the crimping process, and (c) is a longitudinal sectional view of the crimping part and the signal conductor after the crimping process. It is the external appearance perspective view which showed the mode that the connection part crimping piece was attached to the crimping part of the inner conductor terminal after the crimping process shown in FIG. 2 in order. It is the longitudinal cross-sectional view which showed the mode that the connection part crimping piece was attached to the crimping part of the inner conductor terminal after the crimping process shown in FIG. FIG. 3 is a transverse cross-sectional view illustrating, in order, how a connection portion crimping piece is attached to a crimp portion of an inner conductor terminal after the crimping process illustrated in FIG. 2. It is a longitudinal cross-sectional view of the conventional shield connector.

  Hereinafter, a shield connector according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view (cross-sectional view in the longitudinal direction) of a shield connector connected to a coaxial cable (shield cable), and FIG. 2 shows a state in which a signal conductor is connected to a signal conductor connection portion of an inner conductor terminal. FIGS. 3 to 5 are diagrams showing a state in which the connecting portion crimping piece is attached to the signal conductor connecting portion of the inner conductor terminal to which the signal conductor is connected (FIG. 3 is an external perspective view, FIG. 4). Is a longitudinal sectional view, and FIG. 5 is a transverse sectional view (cross-sectional view in the lateral direction). In the following description, the shield connector according to the present embodiment will be described with the connection side with a mating connector (not shown) as the front.

  As shown in FIG. 1, the shield connector 1 includes an inner conductor terminal 2 to which the signal conductor Wa of the coaxial cable W is connected at the end of the coaxial cable W, a dielectric 5 that holds the inner conductor terminal 2, and the dielectric The body 5 is held on the inner side, and the outer conductor terminal 6 is connected to the shield conductor Wc of the coaxial cable W.

  The coaxial cable W includes a signal conductor Wa formed by twisting and bundling a plurality of strands such as copper wires as a transmission path for electrical signals, a shield conductor Wc composed of a braided wire formed by braiding a plurality of strands, and these An insulator Wb interposed between the conductors and an insulating sheath Wd covering the outer periphery of the shield conductor Wc are arranged coaxially. The outer periphery of the signal conductor Wa is covered with the shield conductor Wc without a gap, and is electromagnetically shielded.

  As shown in the figure, the end of the coaxial cable W has the sheath Wd peeled off for a predetermined length to expose the shield conductor Wc, and the exposed shield conductor Wc is peeled off for a predetermined length to expose the insulator Wb. The exposed insulator Wb is peeled off for a predetermined length to expose the signal conductor Wa.

  The inner conductor terminal 2 of the shield connector 1 connected to the signal conductor Wa is formed by integrally bending a conductive plate material, has a so-called female terminal shape, and the signal conductor Wa. Are provided on the rear side, and a terminal part 4 connected to a male inner conductor terminal of a mating connector (not shown) is provided on the front side.

  The crimping part 3 of the inner conductor terminal 2 includes a bottom plate part 3b of the crimping part 3 on which the terminal part of the signal conductor Wa is placed, and a pair of shield-shaped crimping pieces 3a in a strip shape extending from the bottom plate part 3b. 3a. The crimping pieces 3a, 3a are formed in a sufficient length so as to be widened upward and to be wound around the signal conductors of coaxial cables having various diameters.

  The terminal portion of the signal conductor Wa is crimped to the crimping portion 3 of the inner conductor terminal 2 as follows. That is, as shown in FIG. 2A, the terminal portion of the signal conductor Wa is placed on the bottom plate portion 3 b of the crimping portion 3 of the inner conductor terminal 2. Thereafter, the respective crimping pieces 3a, 3a are bent inward by a crimping machine (not shown) to be in a state as shown in FIG. 2 (b) and FIG. 2 (c). Thereby, the inner conductor terminal 2 and the signal conductor Wa are electrically connected. As will be described later, since the signal conductor Wa is folded and crimped by the connecting portion crimping piece 9, the tip of the signal conductor Wa protrudes from the crimping portion 3 by a predetermined length. Crimping is applied.

  On the other hand, as shown in FIG. 1, the terminal portion 4 of the inner conductor terminal 2 has a substantially cylindrical shape, and a pair of elastic contact pieces 4 a and 4 a formed by being folded inside the terminal portion 4. Is provided. These elastic contact pieces 4a and 4a can be elastically bent and deformed, and elastically when a tab portion of a male inner conductor terminal of a mating connector (not shown) is inserted between the elastic contact pieces 4a and 4a. The signal can be exchanged by contact. Further, on the upper surface of the terminal portion 4, a locking piece 4 b is provided so as to be elastically bent and deformable upward.

  The dielectric 5 that accommodates and holds the inner conductor terminal 2 is integrally formed in a substantially cylindrical shape with an insulating synthetic resin having a predetermined relative dielectric constant. Due to the dielectric 5, the inner conductor terminal 2 and the outer conductor terminal 6 are in an insulated state. A terminal accommodating chamber 5a that opens in the front-rear direction is formed through the dielectric 5 so that the inner conductor terminal 2 is accommodated and held in the terminal accommodating chamber 5a. A locking hole 5b for locking the locking piece 4b of the inner conductor terminal 2 is formed in the ceiling surface behind the terminal accommodating chamber 5a, and the locking of the inner conductor terminal 2 is performed in the locking hole 5b. When the piece 4b is locked, the inner conductor terminal 2 is held so as not to easily come out of the terminal accommodating chamber 5a. The lower surface of the dielectric 5 is provided with a lock protrusion 5c protruding downward.

  The outer conductor terminal 6 holding the dielectric 5 is integrally formed by bending a conductive plate material, and the substantially cylindrical shell portion 7 to which the dielectric 5 is attached is moved forward. And a crimping portion 8 to which the coaxial cable W is fixed by crimping.

  On the lower surface on the front side of the shell portion 7 is a stabilizer 7a that is inserted into a slit formed in the bottom surface of the housing portion of the connector housing when the outer conductor terminal 6 is housed in the housing portion of the connector housing (not shown). Is formed to protrude. The direction in which the outer conductor terminal 6 is inserted into the connector housing is regulated by the stabilizer 7a. Further, a guide piece 7c for guiding the stabilizer 7a to the bottom slit of the housing portion of the connector housing when the outer conductor terminal 6 is inserted into the connector housing is provided at the tip of the opening 7b generated by the formation of the stabilizer 7a. It is formed in a tapered shape.

  And the lock piece 7d is formed in the back side lower surface of the shell part 7 so that it can bend and deform | transform toward upper direction. When the dielectric 5 is inserted into the shell portion 7 of the outer conductor terminal 6, the lock protrusion 5c formed to protrude from the rear lower surface of the dielectric 5 engages with the lock piece 7d, and the dielectric 5 It is held so as not to easily come off from the portion 7. In addition, on the left and right side walls of the shell portion 7, tongue-shaped contact pieces (not shown) that elastically contact the outer wall of the outer conductor terminal of the mating connector are formed.

  The inner side of the crimping portion 8 of the outer conductor terminal 6 is formed in a stepped shape so that the shield conductor Wc terminal portion and the sheath Wd terminal portion of the coaxial cable W are appropriately placed. The crimping portion 8 includes a pair of strip-shaped shield conductor crimping pieces 8 a and 8 a extending upward from the bottom surface of the crimping portion 8, and a pair of strip-shaped sheath crimping pieces 8 b and 8 b in the same manner. It is provided in a row. The shield conductor crimping pieces 8a and 8a and the sheath crimping pieces 8b and 8b have a sufficient length so that they can be wound around coaxial cables having various diameters.

  In the crimping portion 8 of the outer conductor terminal 6, a through hole 8c is formed at the center of the bottom surface where the shield conductor crimping piece 8a is formed. When the end portion of the shield conductor Wc is crimped by the shield conductor crimping pieces 8b, 8b, a part of the shield conductor Wc enters the through hole 8c.

  As shown in FIGS. 3 to 5, the signal conductor Wa is crimped to the outer periphery of the crimping portion 3, which is a connection portion between the inner conductor terminal 2 of the shield connector 1 having such a configuration and the signal conductor Wa. A connecting portion crimping piece 9 made of a conductive metal material is attached so as to cover the crimping portion 3 after the contact. The connecting portion crimping piece 9 has a shape such that the left and right crimping pieces 9a, 9a are diverging upward from the bottom surface 9b before being attached to the crimping portion 3. The crimping pieces 9a, 9a of the connecting part crimping piece 9 have a sufficient length so that they can be wound around the crimping part after crimping processing of inner conductor terminals of various diameters. As shown in FIGS. 3 to 5, in the present embodiment, the signal conductor Wa folded at the end portion on the tip end side of the crimping portion 3 is sandwiched between the crimping portion 3 and the connection portion crimping piece 9. Has been.

  The connecting portion crimping piece 9 is mounted as follows. First, the crimping part 3 after the crimping process of the inner conductor terminal 2 is placed on the bottom surface 9b of the connecting part crimping piece 9 (see FIGS. 3A to 5A). Then, the signal conductor Wa protruding in advance from the crimping part 3 by a predetermined length is folded back to the rear end side at the end part of the crimping part 3 (see FIGS. 3B to 5B).

  Thereafter, the respective crimping pieces 9a, 9a of the connecting portion crimping piece 9 are bent inward by a crimping machine (not shown). Specifically, the connection portion crimping piece 9 is connected to the crimping portion 3 such that the signal conductor Wa folded back at the end of the crimping portion 3 is sandwiched between the crimping portion 3 and the connection portion crimping piece 9. (Refer to FIG. 3C to FIG. 5C).

  Thus, the outer diameter of the crimping part 3 is increased by winding the connecting part crimping piece 9 around the outer periphery of the crimping part 3 after the inner conductor terminal 2 is crimped. Moreover, since the connecting portion crimping piece 9 is mounted so as to sandwich the signal conductor Wa folded between the connecting portion crimping portion 3 and the connecting portion crimping piece 9 is simply wound around the crimping portion 3. Instead, the outer diameter of the crimping part 3 can be increased by the amount of interposition of the signal conductor Wa. Thereby, the high characteristic impedance in the vicinity of the crimping part 3 after the crimping process, which has a smaller diameter than the terminal part 4 of the inner conductor terminal 2, is the characteristic impedance in a part other than the crimping part 3 of the coaxial cable W or the shield connector 1. Can be lowered to match.

  Further, since the signal conductor Wa folded back at the end of the crimping part 3 is sandwiched between the crimping part 3 and the connection part crimping piece 9, the connection strength of the signal conductor Wa to the shield connector 1 can be increased. In addition, since the contact area between the signal conductor Wa and the inner conductor terminal 2 is increased, the electrical connection between the two is improved.

  Furthermore, since the outer diameter of the crimping part 3 is increased simply by crimping the connecting part crimping piece 9 made of a conductive plate material to the crimping part 3 after the crimping process of the inner conductor terminal 2, There is no need to pass the metal sleeve over the exposed insulator Wb of the coaxial cable W as in the case where the diameter of the crimping portion 3 is increased by mounting the metal sleeve, and the crimping portion 3 of the inner conductor terminal 2 is not necessary. Workability to increase the diameter is improved. Further, since the outer diameter of the crimping portion 3 is made larger by using the signal conductor Wa that has been drawn out excessively in advance and turned back at the end of the crimping portion 3, the signal conductor connecting portion 9 is made thicker as in the past. A new member for increasing the diameter is not required, leading to a reduction in manufacturing cost.

  Furthermore, in this embodiment, as shown in FIG. 4, the length of the folded portion of the signal conductor Wa, that is, the length of the signal conductor Wa sandwiched between the crimping portion 3 and the connecting portion crimping piece 9. However, it is comprised so that it may become substantially the same as the length of the signal conductor connection part 9 in the folding | turning direction (or more than that). By doing in this way, in the return direction of the signal conductor Wa, there are a portion where the signal conductor Wa is interposed and a portion where the signal conductor Wa is not interposed between the crimping portion 3 and the connection portion crimping piece 9, thereby 9 is prevented from being crimped in a non-uniform state (for example, the joint crimping piece 9 is tilted and crimped, or a part of the joint crimping piece 9 is crushed during crimping). Further, the connection state of the signal conductor Wa to the shield connector 1 and the electrical connection state of the signal conductor Wa and the inner conductor terminal 2 can be further improved.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, the connecting portion crimping piece 9 may not be crimped so that the crimping pieces 9a and 9a overlap as shown in FIGS. That is, in order to match the characteristic impedance in the vicinity of the crimping part 3 with the characteristic impedance in the part other than the crimping part 3, the crimping of the connecting part crimping piece 9 is changed so that the outer diameter of the connecting part crimping piece 9 after the crimping is changed. The shape can be changed as appropriate.

1 Shield Connector 2 Inner Conductor Terminal 3 Crimp (Signal Conductor Connection)
6 Outer conductor terminal 9 Connection part crimping piece W Coaxial cable (shielded cable)
Wa Signal conductor Wb Insulator Wc Shield conductor Wd Sheath

Claims (2)

  The signal conductor is connected in a shield connector in which an insulator is interposed between the signal conductor and the shield conductor, and an end portion of the shield cable in which the outer periphery of the shield conductor is covered with an insulating sheath is connected. An inner conductor terminal having a signal conductor connection portion; and an outer conductor terminal that accommodates the inner conductor terminal with a dielectric interposed therebetween and to which the shield conductor is connected. Folded at the end of the conductor connecting portion, and the folded portion is sandwiched between the signal conductor connecting portion and the connecting portion crimping piece made of a conductive plate attached to the outer periphery of the signal conductor connecting portion. Shield connector characterized by.   The shield connector according to claim 1, wherein a length of the signal conductor folded back at an end portion of the signal conductor connection portion is equal to or greater than a length of the signal conductor connection portion.

Images