Communication cable connector and communication cable with connector

Abstract

To provide a communication cable for high-speed communication to be disposed between railway vehicles which has good operability while achieving their communication performance and durability at high level.SOLUTION: A connector 1A comprises an insulation stage 14A into which a contact 16 is inserted so as to surround an outer peripheral side of a fixed metal fitting 15 mounted to one end side of a communication cable for a railway vehicle having a signal wire forming a twist pair wire around a tension member 31 to which an end part side is fixed with the fixed metal fitting 1. As a combination of divided insulation stages 140 defined by dividing the insulation stage 14A into a number of pairs so as to insert a pair of contacts 16, 16, respectively, a conducive external contact piece 12A having divided body insertion holes 12a, 12b, 12c, and 12d that cover and hold all of external peripheral surfaces excluding a base end part of the division insulation stage 140 to a tip end side is provided. Partition walls separating neighboring ones of the divided body insertion holes 12a, 12b, 12c, and 12d from each other also serve as shield walls between a pair of contact and signal wires.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a connector for a communication cable and a communication cable with a connector, and particularly to a connector for connecting a communication cable for high-speed communication between railway vehicles, and a communication cable with a connector having the same on at least one end side.

Background Art

[0002] In recent railway vehicles, since it is required to transmit signals such as vehicle control signals and image signals of in-vehicle cameras in large quantities and at high speeds, a method using Ethernet (registered trademark) of 100 Mbit / sec has become common, and a large number of signal transmission means such as communication cables and connectors for realizing the communication level have also been developed.

[0003] For such an increase in the capacity and speed of data communication, it is necessary to ensure transmission characteristics in a wide frequency range, and in particular, it is required to sufficiently ensure characteristics in the high-frequency range. In order to ensure the characteristics in this high-frequency range, a method of transmitting a signal used for communication as a differential signal through a twisted pair wire in which two signal lines are twisted together is also well known.

[0004] In this case, in order to perform high-speed communication at the 100 Mbit / sec level between railway vehicles, a communication cable having at least two pairs of twisted pair wires is required. However, in recent years, higher transmission speeds have also been required, and since communication at the 1 Gbit / sec level or higher is also assumed, communication cables having four or more pairs of twisted pair wires have also come to be used.

[0005] On the one hand, the communication cable arranged between railway vehicles is as short as about 1.5 m. However, due to the repeated angular deviation with respect to the running direction caused by the curved running of the vehicle, the durability of the cable terminal part connected to the vehicle side tends to become a problem. Therefore, when incorporating four pairs of twisted pair wires into one communication cable as described above, it is conceivable to incorporate piano wires into each signal wire for the purpose of ensuring the durability of the communication cable. However, there is a problem that the necessary transmission characteristics cannot be ensured because the electrical resistance of the piano wire is large.

[0006] On the other hand, in the communication cable for railway vehicles described in Japanese Patent Application Laid-Open No. 2017-188249, a structure is adopted in which signal lines formed by a plurality of pairs of twisted pair wires are arranged around a tension member formed by a high-tensile wire arranged at the center. By connecting both end sides of the tension member to the vehicle side via connectors, while the tension member bears most of the load applied to the communication cable, a state is ensured in which damage is less likely to occur to each signal line.

[0007] However, the work of fixing both end sides of the communication cable while crimping the end side of the tension member formed by a high-hardness metal wire arranged at the center of the communication cable is not easy. Further, when using a wire of a conductive metal to ensure the strength of the tension member incorporated in the communication cable, since the conductive metal is not electrically connected anywhere, its potential becomes unstable, which easily causes impedance disturbance to the surrounding signal lines.

[0008] To address this problem, the inventors and applicants of the present application proposed, in the previous Patent No. 7288635 Gazette, a method of fixing the end side of the conductive tension member 31 with a fixing fitting 15 made of conductive metal within the insulating base 14B that holds the contact 16, as shown in the connector 1B in Fig. 4. By connecting the connector 1B to the vehicle-side connector and grounding the shield layer of the cable, the tension member 31 is grounded through the fixing fitting 15 and the grounding fitting 17. This method facilitates the operation of fixing the end of the tension member 31 to both ends of the communication cable, and at the same time, it is possible to ground the conductive tension member 31 to reduce the adverse effects on the signal line.

[0009] However, in the connector used for the above-described high-speed communication cable including this connector, crosstalk between signal lines and changes in characteristic impedance are still problems in terms of ensuring communication performance. In particular, when attaching the connector to the cable end, since the contacts in the connector are thicker than the wire diameter of the signal line, the positional relationship between each pair of twisted pair lines spreads more than in the cable state, which easily leads to disturbances in characteristic impedance.

[0010] Also, although it is common for the contacts to be fixed with clips in the contact insertion holes of the insulating base, a gap is provided between the contacts and the inner peripheral surface of the contact insertion holes in order to remove the contacts with a dedicated tool. This has contributed to the instability of the characteristic impedance. Furthermore, when connecting the signal line to the contacts in the connector, if the shield braid of the communication cable is removed at the connection part, the distance between the signal line and the ground connection through the shield braid increases at that part, and there is also a problem that the characteristic impedance of the signal line is more likely to change.

[0011] In response to such problems, Patent Publication No. 6188804 and Patent Publication No. 7150677 propose a connector in which a conductive cross-section shield plate is inserted between pairs constituting a pair so as to shield between the pairs in an insulating base that holds contacts provided on the end side of a twisted pair wire, thereby preventing the occurrence of crosstalk between the twisted pairs. Also, in the connector 1B of FIG. 4 described above, shield plates (shield plates) 171 to 174 extending from the ground connection fitting 17 connected to the fixing fitting 15 are inserted between the pairs of contacts 16, 16, respectively, and crosstalk is prevented in the same manner as described above.

[0012] However, in common with the conventional connectors described above, when connecting a connector to the end side of a communication cable, by peeling the cable, in addition to the characteristic impedance being disturbed at the exposed portion of the twisted pair wire, there is also a concern that crosstalk between the twisted pairs may occur at the portion without the shield. Therefore, in the terminal processing of the cable, since it is necessary to minimize the portion where the twisted pair wire is exposed from the shield layer, the assembly work is not easy, and variations in characteristic impedance are likely to occur depending on the quality of the terminal processing. Also, simply inserting four cross-section shield plates between the twisted pairs cannot cover the entire outer peripheral side, so the shielding performance is still insufficient.

Prior Art Documents

Patent Documents

[0013]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0014] The present invention aims to solve the above problems, and it is an object to provide a communication cable for high-speed communication arranged between railway vehicles, which realizes high-level communication performance and durability while having excellent workability.

Means for Solving the Problems

[0015] Therefore, the present invention is attached to one end side of a communication cable for signal transmission between railway vehicles, which includes signal lines constituting a plurality of pairs of twisted pair lines around a tension member arranged at the center and the outer peripheral side of the bundle of signal lines is covered with a shield layer. Inside the communication cable, a fixing fitting is arranged at the position of the extension line of the central axis of the communication cable to be attached, and a plurality of non-conductive insulating bases having contact insertion holes into which a plurality of columnar contacts, to which the end sides of the signal lines are connected and fixed so as to surround the outer peripheral side thereof, are respectively inserted, are arranged. In a connector for a communication cable in which the end side of the tension member is locked and fixed by the fixing fitting so as not to be pulled out, the insulating base is a combination of divided insulating bases having a shape obtained by dividing a substantially cylindrical insulating base into the number of pairs so as to respectively insert a pair of contacts connected to a pair of signal lines constituting the twisted pair lines. The tip side has a fitting hole for inserting the fixing fitting at the center and an external contact piece made of a conductive cylindrical member having divided body insertion holes for holding each in a state of covering all the outer peripheral surfaces except at least the base end portion of the divided insulating base around the fitting hole. A partition wall separating the adjacent divided body insertion holes by this external contact piece also serves as a shield wall between the inserted pair of contacts and signal lines.

[0016] In this way, by providing a fixing fitting for fixing the end side of the tension member inside the connector, the fixing operation of the tension member becomes easy. In addition, the insulating base is divided into pairs so that it is inserted for each pair of contact and signal lines, and the divided insulating bases are inserted into the divided body insertion holes formed in the conductive external contact pieces respectively. By adopting this method, the arrangement of the contacts is completed only by inserting the divided insulating bases into which the pair of contacts are inserted into the external contact pieces, and the assembly operation is facilitated. Further, the partition wall separating the divided body insertion holes of the external contact pieces also serves as a shield wall between the pair of contact and signal lines located on the inner peripheral side of the divided body insertion hole. Thus, for a predetermined range in the pair of contacts and the twisted pair line connected thereto, the entire outer peripheral side is covered by the shield, enabling high communication performance while exhibiting excellent shielding performance. Moreover, since the portion where the communication line is exposed due to peeling can be lengthened by the amount that fits inside the inner peripheral side of the divided body insertion hole of the exposed twisted pair line, the workability is further improved.

[0017] Also, in this connector for a communication cable, the fixing fitting is made of a conductive material. By connecting the connector attached to one end side of the communication cable or the connector attached to the other end side of the communication cable to the vehicle-side connector having an earth connection and thereby earth-connecting the shield layer, the tension member and the external contact piece are earth-connected via the fixing fitting. If this is made a feature, by simply connecting this connector for a communication cable to the vehicle-side connector, it is possible to significantly reduce the adverse effect on the signal line caused by the conductive tension member while ensuring a stable earth connection, and to realize the shielding function by the external contact piece at a high level.

[0018] Furthermore, in the connector for a communication cable described above, a notch of a predetermined shape is formed at a longitudinal intermediate position on the outer peripheral surface of the split insulating base. With the contacts inserted into the contact insertion holes, a contact retainer shaped to fit into the notch is fitted into the notch from the outside, so that the contact retainer becomes a part of the structure of the split insulating base and a part of it engages with a flange or a stepped portion formed on the outer peripheral surface of the contact, and the contact is fixed to the split insulating base in a non-removable state. Compared with the conventional example using a clip to fix the contact, the attaching and detaching operation of the contact to and from the insulating base becomes extremely easy, and in addition, there is no need to provide a gap for the attaching and detaching operation on the outer peripheral side of the contact, so that the characteristic impedance of that portion is easily stabilized.

[0019] In this case, the split insulating base is longer than the contact into which the contact insertion hole is inserted, and with the contact inserted, the entire contact and a predetermined range of the signal wire connected to the contact are supposed to be accommodated inside the inner peripheral side of the contact insertion hole. If this is made a feature, it becomes easier to further stabilize the characteristic impedance.

[0020] Furthermore, a signal wire constituting a plurality of pairs of twisted pair wires is provided around a tension member made of conductive metal arranged at the center, and the outer peripheral side of the bundle of signal wires is covered with a shield layer. At at least one end side of a communication cable for signal transmission between railway vehicles, if a connector-attached communication cable is formed by attaching the above-described connector for a communication cable, just by arranging it between railway vehicles, all the functions of the above-described connector for a communication cable are exhibited.

Effect of the Invention

[0021] By fixing the end side of the tension member in the connector with a fixing fitting, the fixing work of the tension member can be facilitated. In addition, according to the present invention, each pair of contacts into which the insulating base is inserted is divided and inserted into the divided body insertion holes formed in the conductive external contact pieces. Regarding the communication cable for high-speed communication arranged between railway vehicles, it is possible to achieve excellent workability while realizing high communication performance and durability.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the present invention, the communication cable is used not only for transmitting information and data but also for widely transmitting electrical signals, and is included in the signal transmission cable.

[0024] Fig. 1 shows an exploded perspective view of a connector 1A for a communication cable according to the present embodiment, and Fig. 2 shows an enlarged longitudinal sectional partial view of a communication cable 100 with a connector in which the connector 1A is attached to the end side of the communication cable 30. This connector 1A is attached and used to at least one end side of a communication cable 30 arranged between longitudinally arranged railway vehicles for high-speed communication between the vehicles, and is developed to ensure high workability while ensuring high communication performance and durability of the communication cable 30.

[0025] On one hand, as the communication cable 30 disposed between vehicles, as shown in the longitudinal sectional view of FIG. 2, it includes eight signal lines 32a, ···, 32d, ··· that constitute four pairs of twisted pair lines around a tension member 31 disposed at the center, and the outer peripheral side of the bundle of the signal lines is covered with a shield layer formed by a shield braid 36, which is preferable from the viewpoint of enabling high-speed communication at the 1 Gbit / sec level.

[0026] As the tension member 31 installed in the communication cable 30, it is normal to use a wire material made of a conductive metal such as a wire formed by bundling steel wires having a tensile strength at a predetermined level. However, from the viewpoint of achieving both the durability of the cable terminal portion connected to the vehicle side and the ease of the fixing operation inside the connector, it is preferable to use a so-called jumper wire in which a copper wire and a piano wire are twisted together and provided with a coating.

[0027] And in the connector 1A for the communication cable of the present embodiment, the end side of the tension member 31 disposed at the center of the communication cable 30 is locked and fixed by a fixing metal fitting 15 made of a conductive material disposed in the connector in a non-removable state, enabling the tension member 31 to bear the stress generated on the cable end side and enhancing the resistance to the tensile force and bending force on the end sides of the signal lines 32a, ···. In addition to this, it has a structure in which the tension member 31 is grounded through the conductive fixing metal fitting 15 disposed inside.

[0028] When a conductive metal tension member 31 is arranged at the center of a communication cable to ensure the durability of the communication cable arranged between railway vehicles, if the tension member 31 is not electrically connected anywhere, there is a risk of adversely affecting the communication states of the signal lines 32a, ··· arranged around it. Therefore, a fixing fitting 15 for fixing the tension member 31 in a connector is made of a conductive component and is fixed to an external contact piece 12A. The connector 1A attached to one end side of the communication cable 30 or a connector (not shown) attached to the other end side of the communication cable 30 is connected to a vehicle-side connector that is grounded, and the shield layer is grounded. In this way, the tension member 31 is grounded via the fixing fitting 15. As a result, since the potential of the tension member 31 is stabilized, the adverse effect of the tension member 31 on the communication states of the signal lines 32a, ··· can be minimized.

[0029] And a non-conductive insulating base 14A is provided in which eight columnar contacts (contact pieces) 16 to which the end sides of eight signal lines 32a, ···, 32d, ··· are connected and fixed are inserted in parallel in a cylindrical shape so as to surround the outer peripheral side of the fixing fitting 15. This insulating base 14A has a shape in which a substantially cylindrical insulating base 14A is divided into four pairs along the central axis so that a pair of contacts 16, 16 connected to a pair of signal lines are inserted respectively, and is a combination of divided insulating bases 140, 140, 140, 140 each having contact insertion holes 140a, 140b for inserting a pair of contacts 16, 16 respectively. This point is the greatest feature of the present invention.

[0030] Also, on the tip side of the connector 1A, there is a fitting hole 120 for inserting a fixing fitting 15 at the center, and split insertion holes 12a, 12b, 12c, 12d for holding each while closely covering the inner peripheral surface on at least the entire outer peripheral surface of the split insulating base 140 except for the base end portion are formed annularly at equal intervals around the fitting hole 120. The external contact piece 12A is composed of a conductive cylindrical member. A partition wall separating adjacent split insertion holes 12a, 12b, 12c, 12d in this external contact piece 12A also serves as a shield wall between the inserted pair of contact and signal lines, and this is also an important characteristic part of the present invention.

[0031] In this way, by providing the fixing fitting 15 for fixing the end side of the tension member 31 inside the connector, it is possible to facilitate the fixing work of the tension member. In addition to this configuration, a split insulating base 140, 140, 140, 140, which is formed by splitting a non-conductive insulating base 14A into four identical parts and inserting one for each pair of contacts 16, is combined. By adopting a method of inserting and assembling these into the split insertion holes 12a, 12b, 12c, 12d formed annularly and at equal intervals in the conductive external contact piece 12A, the arrangement of the contacts 16 is completed simply by inserting the split insulating base 140 into which the pair of contacts 16, 16 is inserted into the external contact piece 12A. Therefore, the assembly work of the connector has been greatly facilitated.

[0032] Also, since the partition wall separating the split insertion holes 12a, 12b, 12c, 12d of the external contact piece 12A also serves as a shield wall, it is possible to continuously cover the entire outer peripheral side with a shield for a predetermined range between the pair of contacts and the twisted pair wire. Therefore, high communication performance can be realized while exhibiting high shielding performance. Furthermore, since it is possible to leave the exposed part of the twisted pair wire with the outer skin of the communication cable 30 longer by the length that the exposed twisted pair wire fits inside the split insertion holes 12a, 12b, 12c, 12d, the workability is further improved.

[0033] And as described above, by grounding the shield layer of the communication cable 30, the tension member 31 and the external contact piece 12A are grounded via the fixing fitting 15. Therefore, simply connecting this connector 1A to the vehicle-side connector can ensure a stable ground connection, and thereby a high-level shielding function is realized by the external contact piece 12A.

[0034] In addition, a ring-shaped insulating base retainer 13 is disposed on the proximal end side of the non-conductive insulating base 14A that holds the fixing fitting 15 and the eight contacts 16 connected to each signal line while maintaining their insulation states. The insulating base retainer 13 abuts against the proximal end side of the insulating base 14A and fixes it. Further, the proximal end side of the external contact piece 12A is covered with a wire retainer 11A formed by combining an upper retainer 111 and a lower retainer 112 made of conductive metal that insert and fix the end side of the communication cable 30 on the inner peripheral side. The external contact piece 12A, the insulating base retainer 13, and the wire retainer 11A constitute a cylindrical contact housing in the connector 1A.

[0035] Referring to the exploded perspective view of the split insulating base 140 in FIG. 3, the contact insertion holes 140a and 140b of this split insulating base 140 are formed longer (about twice) than the contacts 16 to be inserted. As shown in the longitudinal sectional view of FIG. 2, in a state where the contacts 16 are inserted to the tip side, a predetermined range (a length comparable to that of the contacts 16 in this embodiment) of the signal lines 32a,... connected to the contacts 16 is accommodated on the inner peripheral side of the contact insertion holes 140a and 140b, ensuring a state where it is easy to stabilize the characteristic impedance of the signal lines 32a,....

[0036] Also, as shown in FIG. 3, the split insulating base 140 that holds the pair of contacts 16, 16 has a notch 141 formed in a shape that is cut in the width direction to a depth reaching the contact insertion holes 140a, 140b at a substantially intermediate position in the longitudinal direction of its outer peripheral surface. And, with the contacts 16, 16 inserted to the tip side of the contact insertion holes 140a, 140b, a contact retainer 142 having a shape that fits into the notch 141 is fitted into the notch 141 from the outside to fix the contacts 16, 16.

[0037] That is, as shown in FIG. 2, by fitting the contact retainer 142 into the notch 141 in a detachable state, while making the outer surface flush with the outer peripheral surface of the split insulating base 140, the contact retainer 142 becomes integral with the split insulating base 140 and becomes part of its structure. The tip surface of the portion that adheres to the outer peripheral surface of the contact 16, which is recessed in a shape with two semi-cylinders arranged side by side on the lower end surface side, engages with the side surfaces of the flanges 16a, 16a formed on the outer peripheral surfaces of the contacts 16, 16, and the contacts 16, 16 are fixed in a state where they cannot be pulled out.

[0038] As a result, compared with the conventional example of using a clip to fix the contacts, the attachment and detachment work of the contacts 16, 16 to the insulating base 14A becomes extremely easy, and since there is no need to provide a gap for performing the attachment and detachment work on the outer peripheral side of the contact 16, the insulating base 14A is likely to stabilize the characteristic impedance as a whole.

[0039] Still, as shown in FIG. 2, a plurality of sets of signal lines 32a, ··· that constitute twisted pair lines are provided around the conductive metal tension member 31 arranged at the center, and the outer peripheral side of the bundle of signal lines is covered with a shield layer by a shield braid 36. If it is provided as a communication cable 100 with a connector in which the above-described connector 1A for a communication cable is attached to one end side of the communication cable 30 used for signal transmission between railway vehicles, by simply arranging this between railway vehicles, all the functions of the above-described connector for a communication cable are exhibited.

[0040] In addition, in the above-described embodiment, the case where the connector 1A includes four divided insulating bases 140 has been described. However, the connector for a communication cable of the present invention is not limited to this, and it goes without saying that the connector may include two or five or more divided insulating bases 140.

[0041] As described above, with respect to the cable for high-speed communication disposed between railway vehicles, according to the present invention, while ensuring high levels of communication performance and durability, the cable has excellent workability.

Explanation of Reference Numerals

[0042] 1A Connector, 12A External Contact Piece, 12a, 12b, 12c, 12d Divided Body Insertion Hole, 14A Insulating Base, 15 Fixture, 16 Contact, 16a Flange, 30 Communication Cable, 31 Tension Member, 32a, 32d Communication Line, 100 Communication Cable with Connector, 120 Fixture Hole, 140 Divided Insulating Base, 140a, 140b Contact Insertion Hole, 141 Notch, 142 Contact Holder

Claims

1. A communication cable connector for signal transmission between railway vehicles, which is provided with signal lines constituting a plurality of pairs of twisted-pair lines around a tension member disposed at the center, and the outer peripheral side of the bundle of the signal lines is covered with a shield layer. The communication cable connector is attached to one end side of the communication cable, and inside thereof, a fixing bracket is disposed at a position along the extension line of the central axis of the communication cable to be attached, and a plurality of columnar contacts to which the end portions of the signal lines are connected and fixed so as to surround the outer peripheral side thereof are respectively inserted. A non-conductive insulating base having a plurality of contact insertion holes is disposed. In the communication cable connector in which the end portion of the tension member is locked and fixed by the fixing bracket so as not to be pulled out, the insulating base is formed by combining divided insulating bases having a shape in which the substantially cylindrical insulating base is divided into the number of pairs so as to respectively insert the pair of contacts connected to the pair of signal lines constituting the twisted-pair line. The tip side thereof is provided with an external contact piece made of a conductive cylindrical member having a fitting hole for inserting the fixing bracket at the center and having split body insertion holes around the fitting hole for holding each in a state of covering at least the entire outer peripheral surface excluding the base end portion of the divided insulating base. A partition wall separating the adjacent split body insertion holes with the external contact piece also serves as a shield wall between the inserted pair of contacts and signal lines. A communication cable connector characterized by the above.

2. The fixing bracket is made of a conductive material, and by connecting the connector attached to one end side of the communication cable or the connector attached to the other end side of the communication cable to a vehicle-side connector that is grounded and grounding the shield layer, the tension member and the external contact piece are grounded via the fixing bracket. The communication cable connector according to claim 1, characterized by the above.

3. The divided insulating base has a notch having a predetermined shape formed at an intermediate position in the longitudinal direction of the outer peripheral surface thereof. With the contact inserted into the contact insertion hole, a contact retainer having a shape that fits into the notch is fitted into the notch from the outside, so that the contact retainer becomes a part of the structure of the divided insulating base, and a part thereof engages with a flange or a stepped portion formed on the outer peripheral surface of the contact, and the contact is fixed to the divided insulating base in a state where it cannot be pulled out. The communication cable connector according to claim 1 or 2, characterized by the above.

4. The split insulating base is longer than the contact into which the contact insertion hole is inserted, and in a state where the contact is inserted, the entire contact and a predetermined range of the signal line connected to the contact are supposed to be accommodated on the inner peripheral side of the contact insertion hole. The communication cable connector according to claim 3, characterized in that.

5. A communication cable for signal transmission between railway vehicles, comprising signal lines constituting a plurality of pairs of twisted pair lines around a tension member made of conductive metal disposed at the center, and the outer peripheral side of the bundle of signal lines being covered with a shield layer. A communication cable with a connector, wherein the communication cable connector according to claim 1 or 2 is attached to at least one end side.

6. A communication cable for signal transmission between railway vehicles, comprising signal lines constituting a plurality of pairs of twisted pair lines around a tension member made of conductive metal disposed at the center, and the outer peripheral side of the bundle of signal lines being covered with a shield layer. A communication cable with a connector, wherein the communication cable connector according to claim 3 is attached to at least one end side.

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