JP2012052992A - Adaptor for cable inspection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adaptor for cable inspection capable of easily and surely inspecting a cable assembly.SOLUTION: The cable adaptor 1(1A, 1B), connected between a network analyzer 60 and a cable assembly 20, has a coaxial cable 10 that is electrically connected to a female outer conductor 4, which is a shield member of a female connector 2, on one end, and has an SMA male connector 15 attached to the other end.

Description

  The present invention relates to a cable inspection adapter connected between a cable assembly in which connectors are provided at both ends of a cable and a measuring instrument for measuring the electrical characteristics of the cable assembly.

  A cable in which an internal conductor is covered with a metal foil or a braid, such as a coaxial cable or a twisted pair cable, is called a shielded cable.

  Among these shielded cables, for example, a twisted pair cable is a pair of twisted pair wires obtained by twisting two wires covered with an insulator around a core wire made of a signal wire, and a thin metal wire around the twisted pair wire. A large number of braided braids are arranged as a shield layer, and the outside is covered with an outer skin formed of an insulating resin or the like.

  Such a shielded cable such as a twisted pair cable is often used for transmission of a high-frequency signal. In the inspection process of the cable assembly in which plugs (connectors) are attached to both ends of the cable, not only conduction but also transmission characteristics are measured and evaluated.

  The inspection process of the cable assembly is performed as follows, for example. First, both ends of the cable assembly are connected to a network analyzer as a measuring instrument, the transmission characteristic with respect to the frequency of the input signal is measured, the measurement data is compared with the inspection specified value, and pass or fail is determined.

  The braid which is the shield layer of the cable is connected to the shield part of the plug at the cable end to form the shield layer of the cable assembly. However, there is a case where the shield is not connected (not electrically connected) between the plugs at both ends because the shield part is not attached to the plug or the cable braid is disconnected. In this case, since the inspection is performed with the ground defective, correct inspection data cannot be obtained.

  Also, if the inspection passes the test and the cable assembly with the shield layer disconnected is shipped, in the system using the cable assembly, the characteristic impedance of the cable partially changes and the signal quality deteriorates. There arises a problem that noise from the cable due to shielding failure is generated, or that there is a difference in the ground level at both ends of the cable assembly, and noise is emitted from the entire system.

  In order to deal with such a problem, for example, methods disclosed in Patent Documents 1 and 2 have been proposed as methods for inspecting cable disconnection and the like. In the method described in Patent Document 1, continuity is measured by short-circuiting the shield layer and the signal line at one end of the cable. In the method described in Patent Document 2, electrostatic noise is applied to the outer skin, and a signal generated in the core wire is detected.

Japanese Patent Laid-Open No. 5-180893 JP 2003-185694 A

  However, the method described in Patent Document 1 does not consider application to a cable assembly in which plugs (connectors) are attached to both ends of the cable. Therefore, there is a problem that it is difficult to connect to the signal line when the shield part of the plug is inside the plug.

  Further, the method described in Patent Document 2 requires a dedicated inspection device and process in addition to the cable assembly characteristic evaluation. Further, since the static electricity generator is moved along the cable, the inspection time is long, and there is a possibility that the insulating layer is broken by voltage application.

  Accordingly, an object of the present invention is to provide a cable inspection adapter that can easily and reliably inspect a cable assembly.

  The invention according to claim 1, which has been made in order to solve the above-described problem, is a cable in which a metal shield portion is provided around a core wire made of a conductor with an insulator interposed therebetween, and is attached to both ends of the cable. A cable assembly including a terminal electrically connected to a core wire and a connector provided with a shield member electrically connected to the metal shield part, and measurement for measuring electrical characteristics of the cable assembly A cable inspection adapter connected between the measuring instrument and the connector, wherein the adapter is detachable and electrically connected to the shield member of the connector and the signal line of the measuring instrument. And a cable inspection adapter comprising a shield inspection part that is insulated from the terminal of the connector. That.

  According to a second aspect of the present invention, in the first aspect of the present invention, the terminal of the connector and the signal line of the measuring instrument are electrically connected and insulated from the shield member of the connector. And a core wire inspection section.

  According to a third aspect of the present invention, in the second aspect of the invention, there is provided switching means for switching which of the shield inspection unit and the core wire inspection unit is electrically connected to the signal line of the measuring instrument. It is characterized by having.

  As described above, according to the first aspect of the present invention, the measuring device and the connector are configured to be detachable and electrically connected to the shield member of the connector and the signal line of the measuring device, and the terminal of the connector. Is provided with a shield inspection section that is insulated from each other, so that it is possible to easily and reliably measure the presence or absence of a break in the shield simply by connecting between the cable assembly and the measuring instrument.

  According to the second aspect of the present invention, since the core wire inspection unit is electrically connected to the connector terminal and the signal line of the measuring instrument and insulated from the shield member of the connector, the shield is provided. In addition to the electrical identification of the cable core, it can also be measured. In addition, since the shield layer can be evaluated in the signal line inspection process, work efficiency can be improved. In addition, since a shield layer is evaluated using a measuring instrument that measures the transmission characteristics of a signal line, a new measuring instrument is unnecessary. Furthermore, since the shield layer can be evaluated before measuring the transmission characteristic of the signal line, the accurate characteristic of the signal line can be measured.

  According to the invention described in claim 3, since the switching means for switching which one of the shield inspection unit and the core wire inspection unit is electrically connected to the signal line of the measuring instrument is provided, only the switching unit is switched. This eliminates the need to change the signal line of the measuring instrument.

It is a top view of the cable assembly to which the cable inspection adapter concerning one Embodiment of this invention is connected. FIG. 2 is a front view of a male connector of the cable assembly shown in FIG. 1 and a cross-sectional view showing a connection portion between the male connector and a cable. It is a top view of the cable inspection adapter concerning one Embodiment of this invention. It is sectional drawing which shows the front view of the female connector of the cable test | inspection adapter shown by FIG. 3, and the connection part of a female connector and a cable. FIG. 4 is a configuration diagram when the cable assembly shown in FIG. 1 is measured using the cable inspection adapter shown in FIG. 3. It is a graph which shows the measurement result measured by the structure shown by FIG. It is a top view of the cable inspection adapter concerning other embodiments of the present invention. It is a top view of the cable inspection adapter concerning other embodiments of the present invention.

  Next, an embodiment of the present invention will be described with reference to FIGS.

  First, a cable assembly 20 to which a cable adapter 1 according to an embodiment of the present invention is connected includes a cable 21 and a male connector 22 as shown in FIG.

  The cable 21 includes signal lines 23, 24, 25, and 26, a braid 27, and an outer skin 28 as shown in the cross-sectional view of FIG.

  The signal line 23 is covered with an insulating outer shell around a core wire 23a formed of a conductor. The same applies to the signal lines 24, 25, and 26. Further, the signal lines 23, 24, 25, and 26 are twisted together to form two pairs of twisted pair wires. The braid 27 as the metal shield part is formed by knitting a number of fine metal wires, and is provided as a shield layer on the outer periphery of the signal lines 23, 24, 25, 26. The outer skin 28 covers the outer side of the braid 27 and is formed of an insulating resin or the like. That is, the cable 21 is a twisted pair cable.

  The male connector 22 is attached to both ends of the cable 21 as shown in FIG. 1, and as shown in FIG. 2, the male case 29, the male outer conductor 30, the male inner conductors 31, 32, 33, 34, And a male insulator 35.

  The male case 29 is formed in a substantially cylindrical shape with an insulating resin or the like, and the end of the cable 21 is inserted (press-fitted) into one end thereof.

  The male outer conductor 30 is formed of a conductor such as metal, is provided along the inner peripheral surface of the male case 29, and is electrically connected by being in contact with the braid 27 of the cable 21. That is, the male outer conductor 30 functions as a shield member. Accordingly, the male outer conductor 30 and the braid 27 constitute a shield layer of the cable assembly 20. As shown in FIG. 2, since the male outer conductor 30 is provided inside the male case 29, it is difficult to reliably contact the tester probe or the like.

  The male inner conductor 31 is accommodated in the male case 29, and is formed in a rod shape with a conductor such as metal. The male inner conductor 31 is provided so that one end protrudes toward the opening on the other end side of the male case 29, and the core wire 23a of the signal line 23 is electrically connected to the other end. Has been. The male inner conductors 32, 33, and 34 are similarly configured, and the core wires 24a, 25a, and 26a of the signal wires 24, 25, and 26 are electrically connected to the other ends, respectively. That is, the male inner conductors 31, 32, 33 and 34 function as terminals of the male connector 22.

  The male insulator 35 is formed in a substantially disk shape with an insulating resin or the like, and is provided inside the male case 29 so as to insulate the male outer conductor 30 and the male inner conductors 31, 32, 33, 34. . The male insulator 35 separates the male case 29 from the portion into which the cable 21 is inserted and the portion into which the female connector 2 described later is inserted, and the male inner conductor 31 and the male through the male inner conductors 31, 32, 33 and 34. The inner conductor 34, the male inner conductor 32, and the male inner conductor 33 are fixed so as to be arranged diagonally.

  A cable adapter 1 as a cable inspection adapter according to an embodiment of the present invention includes a female connector 2, coaxial cables 10, 11, 12, 13, 14 and an SMA male connector as shown in FIGS. 15, 16, 17, 18, and 19, and is configured to be detachable from a male connector 22 of the cable assembly 20 and cables 61 and 63 of a network adapter described later.

  As shown in FIG. 4, the female connector 2 includes a female case 3, a female outer conductor 4, female inner conductors 5, 6, 7, and 8, and a female insulator 9.

  The female case 3 is formed in a substantially cylindrical shape with an insulating resin or the like, and coaxial cables 10, 11, 12, 13, and 14 are led out from one end. Further, the female case 3 is formed so that the inner diameter of the female case 3 is larger than the outer diameter of the male case 29 in order to accommodate a part of the male case 29 inside when the female case 3 is fitted to the male connector 22 described above. ing.

  The female outer conductor 4 as the shield inspection part is formed in a bottomed cylindrical shape with a conductor such as metal and is provided inside the female case 3. Further, since the female outer conductor 4 comes into contact with the male outer conductor 30 when fitted to the male connector 22, the outer diameter of the female outer conductor 4 is formed to be substantially the same as the inner diameter of the male outer conductor 30. That is, the female outer conductor 4 functions as a shield member for the female connector.

  The female inner conductor 5 as the core wire inspection part is housed in the female case 3 and is formed in a bottomed cylindrical shape with a conductor such as metal. The female inner conductor 5 has an opening toward the opening on the other end side of the female case 3, and a conductor 11 a of the coaxial cable 11 is electrically connected to the bottom. Further, when the female inner conductor 5 is fitted to the male connector 22, the male inner conductor 31 is accommodated therein and electrically connected. The female inner conductors 6, 7, and 8 serving as the core wire inspection portion are similarly configured, and the conductors 12a, 13a, and 14a of the coaxial cables 12, 13, and 14 are electrically connected to the bottom portions, respectively.

  The female insulator 9 is formed of an insulating resin or the like, and is provided inside the female outer conductor 4 so as to insulate the female outer conductor 4 and the female inner conductors 5, 6, 7, and 8, respectively. The female insulator 9 is filled and fixed in the female outer conductor 4 so that the male inner conductor 31 and the male inner conductor 34, and the male inner conductor 32 and the male inner conductor 33 are arranged diagonally.

  As shown in FIG. 4B, the coaxial cable 10 as a shield inspection part is provided with a braid 10b around a core wire 10a formed of a conductor covered with an insulator (not shown), and further around the braid 10b. Is covered with the outer skin 10c. The coaxial cable 10 is electrically connected to the core wire 10a and the female outer conductor 4 of the female connector 2 at one end, and electrically connected to the core wire 10a and the SMA (Sub Miniature Type A) male connector 15 at the other end. It is connected. Therefore, the coaxial cable 10, the SMA male connector 15 and the female outer conductor 4 are electrically connected to each other, and the female outer conductor 4 and the male outer conductor 30 ( That is, the shield member is electrically connected. Further, since the female inner conductors 5, 6, 7, and 8 are insulated by the female insulator 9, the male inner conductors 31, 32, 33, and 34 connected to the female inner conductors 5, 6, 7, and 8 ( The signal lines 23, 24, 25, 26) are also insulated.

  As shown in FIG. 4B, the coaxial cable 11 as the core wire inspection part is provided with a braid 11b around a core wire 11a formed of a conductor covered with an insulator (not shown), and further around the braid 11b. Is covered with an outer skin 11c. In the coaxial cable 11, the core wire 11 a and the female inner conductor 5 of the female connector 2 are electrically connected at one end, and the core wire 11 a and the SMA male connector 16 are electrically connected at the other end. The coaxial cables 12, 13, and 14 as the core wire inspection section are similarly configured, and the core wire 12a and the female inner conductor 6, the core wire 13a and the female inner conductor 7, and the core wire 14a and the female inner conductor 8 are electrically connected at one end, respectively. The core wire 12a and the SMA male connector 17, the core wire 13a and the SMA male connector 18, and the core wire 14a and the SMA male connector 19 are electrically connected at the other end. Therefore, for example, the coaxial cable 11, the SMA male connector 16, and the female inner conductor 5 are electrically connected, and the female inner conductor 5 and the male inner conductor are fitted by fitting with the male connector 22 of the cable assembly 20. 31 (that is, a terminal) is electrically connected. Further, since it is insulated from the female outer conductor 4 by the female insulator 9, it is also insulated from the male outer conductor 30 (braid 27) connected to the female outer conductor 4. The same applies to the coaxial cables 12, 13, and 14.

  Next, a method for inspecting the cable assembly 20 having the above-described configuration using the cable adapter 1 will be described with reference to FIG.

  First, a cable 61 as a signal line is connected to a signal output terminal of a network analyzer 60 as a measuring instrument, and a cable 63 as a signal line is connected to a signal input side terminal of the network analyzer 60. Next, one male connector 22 of the cable assembly 20 is inserted into the female connector 2 of the cable adapter 1A and connected (fitted), and the other male connector 22 of the cable assembly 20 is connected to the female connector 2 of the cable adapter 1B. Insert them into and connect them. Then, the SMA female connector 61a provided at the tip of the cable 61 is inserted into the SMA male connector 15 of the cable adapter 1A to connect them, and the SMA female connector 63a provided at the tip of the cable 63 is connected to the cable adapter 1B. Insert into the SMA male connector 15 to connect them. By connecting in this way, the network analyzer 60, the cable 61, the cable adapter 1A, the cable assembly 20, the cable adapter 1B, the cable 63, and the network analyzer 60 are connected as shown in FIG.

  In the connection of FIG. 5, since the cable adapters 1 </ b> A and 1 </ b> B connect the cables 61 and 63 of the network analyzer 60 to the SMA male connector 15, signals are sent from the network analyzer 60 to the SMA male connector 15, the core wire 10 a, and the female outer conductor 4. The male outer conductor 30, the braid 27, the male outer conductor 30, the female outer conductor 4, the core wire 10a, and the SMA male connector 15 are transmitted to the network analyzer 60. That is, a path for confirming the conduction of the shield layer of the cable assembly 20 is formed.

  Next, the network analyzer 60 is operated to perform measurement. FIG. 6 shows an example of measurement results. FIG. 6 is a graph showing frequency on the horizontal axis and reflection characteristics on the vertical axis. Since the DC component is transmitted when the shield of the cable assembly 20 is conducted, the frequency 0 Hz in the reflection characteristic graph is negative. Further, if the shield of the cable assembly 20 is broken, the DC component is not transmitted, so the frequency 0 Hz in the reflection characteristic graph becomes zero. Thus, the conduction of the shield layer can be confirmed from the measurement result of the reflection characteristics.

  Next, when the measurement result of the shield layer is normal, the SMA female connector 61a is disconnected from the SMA male connector 15 of the cable adapter 1A and connected to the SMA male connector 16, and the SMA female connector 63a is connected to the SMA male connector of the cable adapter 1B. 15 is removed and connected to the SMA male connector 16. In this way, signals from the network analyzer 60 are transmitted from the SMA male connector 15, the core wire 11a, the female inner conductor 5, the male inner conductor 31, the core wire 23a (signal line 23), the male inner conductor 31, the female inner conductor 5, the core wire 11a, A path is formed that travels with the SMA male connector 15 and returns to the network analyzer 60. That is, a path for confirming the signal line 23 of the cable assembly 20 is formed. Then, the measurement is performed by the network analyzer 60, and the inspection result of the signal line is determined from the measurement result.

  Thereafter, similarly, the SMA male connector 17 (signal line 24), the SMA male connector 18 (signal line 25), and the SMA male connector 19 (signal line 26) are sequentially connected and measured, and the inspection result is judged.

  According to the present embodiment, the cable adapter 1 connected between the network analyzer 60 and the cable assembly 20 is electrically connected to the female outer conductor 4 that is the shield member of the female connector 2 at one end, A coaxial cable 10 having an SMA male connector 15 attached to the other end is provided. Therefore, the male outer conductor 30 which is a shield member of the male connector 22 of the cable assembly 20 and the cables 61 and 63 connected to the network analyzer 60 are electrically connected, and the male inner conductor of the male connector 22 of the cable assembly 20. Since 31, 32, 33, and 34 are insulated from each other, it is possible to easily and surely measure the presence or absence of breakage of the shield layer simply by connecting the cable adapter 1 between the cable assembly 20 and the network analyzer 60.

  Further, the cable adapter 1 is electrically connected to the female inner conductors 5, 6, 7, 8 which are terminals of the female connector 2 at one end, and the SMA male connectors 16, 17, 18, are connected to the other end. Since the coaxial cable 11, 12, 13, 14 to which 19 is attached is provided, not only the shield layer but also the signal lines 23, 24, 25, 26 of the cable assembly 20 are measured to determine the inspection result. It can be carried out.

  In addition, since the shield layer can be evaluated in the signal line inspection process, work efficiency can be improved. Further, since the shield layer is evaluated using the network analyzer 60 that measures the transmission characteristics of the signal line, a new measuring device is not necessary. Furthermore, since the shield layer can be evaluated before measuring the transmission characteristic of the signal line, the accurate characteristic of the signal line can be measured.

  In the above-described embodiment, the male inner conductors 31, 32, 33, and 34 of the male connector 22 of the cable assembly 20, that is, the terminals are arranged diagonally. However, when the terminals are arranged horizontally, FIG. As shown in (1), the substrate can be used.

  The cable adapter 40 shown in FIG. 7 includes a substrate 41, a female connector 42, and SMA male connectors 43, 44, 45, and 46.

  The substrate 41 is an insulating member having a uniform thickness and is formed in a substantially rectangular shape. The female connector 42 is provided at the right end of the substrate 41 in the figure, and a terminal (female inner conductor) is disposed so as to be connectable to the male connector 22 of the cable assembly 20 in which a male inner conductor (not shown) is disposed horizontally. The SMA male connectors 43 and 44 are provided so as to protrude from the upper end of the board 41 in the drawing, the SMA male connectors 45 and 46 are provided so as to protrude from the left end of the board 41 in the drawing, and the SMA male connector 47 is provided on the board 41. It protrudes from the middle and lower ends.

  On the substrate 41, wirings 48, 49, 50, 51, 52 are formed. One end of the wiring 48 is electrically connected to a female outer conductor that is a shield member (not shown) of the female connector 42, and the other end is electrically connected to the SMA male connector 43. One end of the wiring 49 is electrically connected to a female inner conductor that is a terminal (not shown) of the female connector 42, and the other end is electrically connected to the SMA male connector 44. One end of the wiring 50 is electrically connected to a female inner conductor that is a terminal (not shown) of the female connector 42, and the other end is electrically connected to the SMA male connector 45. One end of the wiring 51 is electrically connected to a female inner conductor that is a terminal (not shown) of the female connector 42, and the other end is electrically connected to the SMA male connector 46. One end of the wiring 52 is electrically connected to a female inner conductor which is a terminal (not shown) of the female connector 42, and the other end is electrically connected to the SMA male connector 47.

  Wirings 49 and 50 are connected to female inner conductors corresponding to the signal lines of a pair of twisted pair lines, and wirings 51 and 52 are connected to female inner conductors corresponding to the signal lines of another pair of twisted pair lines.

  The cable adapter 40 having the configuration described above is connected in the same manner as the configuration shown in FIG. 5, that is, the male connector 22 of the cable assembly 20 is connected to the female connector 42, and the SMA male connectors 43, 44, 45, 46, 47 are connected. Any one of them can be connected to the network analyzer 60 to measure the shield or signal line of the cable assembly 20.

  In the above-described embodiment, the switching of the measurement target such as the shield and each signal line is performed by switching the cables 61 and 63 connected from the cable adapter 1 to the network analyzer 60. However, FIG. Thus, by using the switching device 70 as the switching means, it is possible to switch the measurement object without switching. As the switcher 70, for example, a microwave switch or the like can be used.

  Further, when the substrate 41 is used as shown in FIG. 7, by providing a changeover switch circuit or the like as a switching means on the substrate 41, the measurement object can be switched without changing the connection as in FIG. 8.

  The present invention can be applied not only to twisted pair cables but also to other shielded cables such as coaxial cables.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

1 Cable adapter (Cable inspection adapter)
2 Female connector (shield measurement part, core wire measurement part)
10 Coaxial cable (shield measurement part)
11-14 Coaxial cable (core wire measuring part)
15 SMA male connector (shield measurement part)
16-19 SMA male connector (core wire measuring part)
20 Cable assembly 21 Cable 22 Male connector (connector)
23a-26a Core wire 27 Braid (metal shield part)
30 Male outer conductor (shield member)
31-34 Male inner conductor (terminal)
60 Network analyzer (measuring instrument)
61, 63 Coaxial cable (signal line of measuring instrument)
70 switching device (switching means)

Claims (3)

A cable in which a metal shield portion is provided around an insulator around a core wire made of a conductor, a terminal attached to both ends of the cable and electrically connected to the core wire, and the metal shield portion electrically A cable inspection adapter connected between a cable assembly provided with a shield member to be connected, and a measuring instrument for measuring electrical characteristics of the cable assembly,
A shield inspection unit configured to be detachable from the measuring instrument and the connector, electrically connected to the shield member of the connector and a signal line of the measuring instrument, and insulated from the terminal of the connector. Cable inspection adapter characterized by comprising.   2. The core wire inspection unit according to claim 1, further comprising a core wire inspection unit that is electrically connected to the terminal of the connector and a signal line of the measuring instrument and is insulated from the shield member of the connector. Adapter for cable inspection as described.   The cable inspection adapter according to claim 2, further comprising a switching unit that switches which of the shield inspection unit and the core wire inspection unit is electrically connected to the signal line of the measuring device. .

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