Shield performance measurement device for wire harness

Abstract

One aspect of the present disclosure provides a shield performance measurement device for a wire harness, the shield performance measurement device making it possible to improve measurement accuracy. In a termination connection member (24) used in a measurement device, an insulating resin adhesive sheet (24y) is provided in close contact with a circuit board (24b) so as to cover a termination resistor (24a), and a conductive metal sheet (24x) is provided in close contact with the insulating resin adhesive sheet (24y). The conductive metal sheet (24x) and the insulating resin adhesive sheet (24y) function as a parasitic capacitor in a measurement circuit including the termination connection member (24), and act in a direction of lowering the impedance of the measurement circuit.

Description

Apparatus for Measuring Shielding Performance of Wire Harness

[0001] The present disclosure relates to an apparatus for measuring shielding performance of a wire harness.

[0002] For in-vehicle wire harnesses having shielded wires and the like, it is required to guarantee desired EMC (Electromagnetic Compatibility) performance at the installation location. Therefore, the shielding performance of wire harnesses is measured and evaluated on a regular basis. As one of the methods for measuring the shielding performance of wire harnesses, a method conforming to the international standard IEC62153-4-7 is known.

[0003] For wire harnesses that perform high-speed communication, various measures have been taken during implementation to perform impedance matching using a terminating resistor and eliminate factors that hinder high-speed communication (see, for example, Patent Document 1).

[0004] Japanese Utility Model Publication No. 6-38277

[0005] Therefore, even in a shielding performance measuring apparatus, when a wire harness intended for high-speed communication is the object to be measured, it is necessary to perform impedance matching using a terminating resistor. The inventor of the present invention intends to improve measurement accuracy by performing more appropriate impedance matching related to the terminating resistor.

[0006] An object of the present disclosure is to provide an apparatus for measuring shielding performance of a wire harness that can improve measurement accuracy.

[0007] The wire harness shielding performance measuring device of the present disclosure is a wire harness shielding performance measuring device for measuring a wire harness using a shielded wire including a communication wire and a shielding member provided on the outside of the communication wire, wherein the measuring device comprises a conductive metal tubular member for housing the wire harness, a conductive metal contact jig that is attached to the shielded wire of the wire harness and electrically connected to the shielding member, and electrically connected to the tubular member when the wire harness is housed in the tubular member, and an electrical connection of the shielded wire to the communication wire The terminal connection member has a circuit board on which a terminating resistor is mounted for impedance matching connected to the shield wire, an input unit for injecting a measurement signal into the communication line of the shield wire, and a measurement unit for measuring the shielding performance of the wire harness by acquiring the leakage of electromagnetic waves from the shield wire to the shield member based on the injection of the measurement signal through the contact jig and the tube member, wherein the terminal connection member comprises an insulating resin sheet provided in close contact with the circuit board so as to cover the terminating resistor, and a conductive metal sheet provided in close contact with the insulating resin sheet.

[0008] The wire harness shielding performance measuring device described herein can improve measurement accuracy.

[0009] Figure 1 is a longitudinal cross-sectional view of a wire harness being measured according to one embodiment. Figure 2 is a transverse cross-sectional view of a wire harness being measured according to one embodiment. Figure 3 is a configuration diagram of a shield performance measuring device according to one embodiment. Figure 4 is a configuration diagram of a wire harness with a contact jig attached and the inner tube of the measuring device according to one embodiment. Figure 5 is a configuration diagram of a wire harness with a contact jig attached according to one embodiment. Figure 6 is a configuration diagram of a terminal connection member according to one embodiment. Figure 7 is a configuration diagram of a terminal connection member according to one embodiment. Figure 8 is a waveform diagram showing the measurement results using the terminal connection member according to one embodiment. Figure 9 is a waveform diagram showing the measurement results using the terminal connection member according to one embodiment.

[0010] [Description of Embodiments of the Disclosure] Embodiments of the Disclosure will be listed and described first. [1] The wire harness shielding performance measuring device of the Disclosure is a wire harness shielding performance measuring device for measuring a wire harness using a shielded wire including a communication wire and a shielding member provided on the outside of the communication wire, the measuring device comprising: a conductive metal tubular member for housing the wire harness; a conductive metal contact jig that is attached to the shielded wire of the wire harness and electrically connected to the shielding member, and electrically connected to the tubular member when the wire harness is housed in the tubular member; and an electric wire for the communication wire of the shielded wire. The terminal connection member comprises a circuit board on which a termination resistor for impedance matching is mounted and electrically connected; an input unit for injecting a measurement signal into the communication line of the shielded wire; and a measurement unit for measuring the shielding performance of the wire harness by acquiring the leakage of electromagnetic waves from the shielded wire to the shielding member based on the injection of the measurement signal through the contact jig and the tube member. The terminal connection member comprises an insulating resin sheet provided in close contact with the circuit board so as to cover the termination resistor, and a conductive metal sheet provided in close contact with the insulating resin sheet.

[0011] In this configuration, a terminating connector for impedance matching of the wire harness under measurement is provided with an insulating resin sheet in close contact with the circuit board so as to cover the terminating resistor, and a conductive metal sheet in close contact with the insulating resin sheet. Since the conductive metal sheet and the insulating resin sheet function as parasitic capacitors, the capacitance component of the parasitic capacitors cancels out the inductance component of the terminating connector, which acts to lower the impedance of the measurement circuit. In other words, even for objects under measurement where the inductance component of the terminating connector affects the measurement accuracy, an improvement in measurement accuracy can be expected.

[0012] [2] In the above [1], the insulating resin sheet is made of an insulating resin adhesive sheet having adhesive layers on both sides, and the terminal connection member may be made by attaching the insulating resin sheet to the circuit board and the conductive metal sheet, respectively.

[0013] In this configuration, the insulating resin sheet is an adhesive insulating resin sheet having adhesive layers on both sides, and is attached to both the circuit board and the conductive metal sheet. In other words, since the installation work for the insulating resin sheet can be done by attachment, it is possible to easily install both the conductive metal sheet and the insulating resin sheet onto the circuit board.

[0014] [3] In [1] or [2] above, the termination connection member is provided with a pair of termination resistors, and the insulating resin sheet and the conductive metal sheet may be configured to cover the pair of termination resistors together.

[0015] In this configuration, the insulating resin sheet and the conductive metal sheet are provided to cover the pair of termination resistors together. In other words, since the installation of the insulating resin sheet and the conductive metal sheet can be done at once, it is possible to easily install the conductive metal sheet and the insulating resin sheet on the circuit board.

[0016] [4] In any one of [1] to [3] above, the insulating resin sheet and the conductive metal sheet are each flexible, and the termination connecting member may be configured such that the insulating resin sheet and the conductive metal sheet adhere closely to the circuit board including the termination resistor which is in a protruding configuration as they deform.

[0017] In this configuration, the insulating resin sheet and the conductive metal sheet are both flexible and deform to adhere closely to the circuit board, including the protruding termination resistor, upon installation. In other words, the conductive metal sheet and the insulating resin sheet can function effectively as parasitic capacitors.

[0018] [5] In any one of [1] to [4] above, the wire harness to be measured may be one that performs high-speed communication using multi-gigabit signal frequencies. With this configuration, in a wire harness for high-speed communication using multi-gigabit signal frequencies, the inductance component of the termination connection member becomes more significant, so there is great significance in using the conductive metal sheet and the insulating resin sheet as parasitic capacitors to lower the impedance of the measurement circuit. In other words, even with a wire harness to be measured intended for high-speed communication, a significant improvement in measurement accuracy can be expected.

[0019] [Details of Embodiments of the Disclosure] Next, details of embodiments of the disclosure will be described with reference to the drawings. In the drawings used in this embodiment and the other embodiments described later, some parts of the configuration may be exaggerated or simplified for the sake of explanation. Also, the dimensional ratios of each part may differ in each drawing. The present invention is not limited to these examples, but is shown in the claims, and all modifications within the meaning and scope equivalent to the claims are intended.

[0020] (An example of a wire harness 10 to be measured) The wire harness 10 shown in Figures 1 and 2 is an example of a device to be measured by the measuring device 20 of this embodiment shown in Figure 3. The wire harness 10 is used, for example, as a transmission line for high-speed communication that constitutes an in-vehicle network. The wire harness 10 comprises a shielded wire 11 and a connector 12 that is attached to the longitudinal end of the shielded wire 11.

[0021] The shielded cable 11 comprises a pair of communication wires 13a and 13b, a cylindrical shielding member 14 that covers the outer circumference of each communication wire 13a and 13b collectively, and a cylindrical sheath 15 that covers the outer circumference of the shielding member 14. Each communication wire 13a and 13b has a core wire 13x made of stranded conductive metal wire and an insulating coating 13y that covers the outer circumference of the core wire 13x. The shielding member 14 is a braided wire in which conductive metal strands are woven into a cylindrical shape. The shielding member 14 is provided on the outside of each communication wire 13a and 13b and has the function of shielding electromagnetic waves from the inside communication wires 13a and 13b toward the outside, and shielding electromagnetic waves from the outside toward the inside communication wires 13a and 13b. The sheath 15 is provided on the outside of the shielding member 14 and is an outer covering member that protects the inside shielding member 14 and the communication wires 13a and 13b.

[0022] In this embodiment, the wire harness 10 to be measured is, as an example, a hollow structure having a gap x between the communication lines 13a and 13b and the shielding member 14 in cross-section. However, it may also be a solid structure in which insulating resin material is provided in the gap x. The measuring device 20 of this embodiment measures the shielding performance of the wire harness 10 having the shielded wire 11 described above.

[0023] (Configuration of the measuring device 20) The measuring device 20 of this embodiment shown in Figure 3 performs measurements in accordance with the international standard IEC 62153-4-7. The measuring device 20 comprises an outer tube 21, an inner tube 22, a contact jig 23 (see Figure 4), a terminal connecting member 24 (see Figure 6), an input unit 25, and a measuring unit 26.

[0024] The outer tube 21 and the inner tube 22 are both made of conductive metal and are substantially cylindrical in shape. The inner tube 22 has a smaller diameter than the outer tube 21 and is used in a manner in which it is inserted into the outer tube 21 during measurement. The wire harness 10 to be measured is inserted into the inner tube 22.

[0025] As shown in Figure 4, the inner tube 22 comprises a tube body 22a and an end cap 22b. The tip of the inner tube 22 has threaded portions 22c and 22d on the outer surface of the tube body 22a and the inner surface of the end cap 22b, respectively, and the end cap 22b is configured to be screwed onto the tube body 22a. When measuring the shielding performance with the measuring device 20, the wire harness 10 with the contact jig 23 attached is housed inside the inner tube 22.

[0026] (Configuration and mounting of contact jig 23) As shown in Figure 5, the contact jig 23 comprises a pair of plate members 23a and 23b. Each plate member 23a and 23b is made from, for example, a conductive metal plate. Each plate member 23a and 23b is attached to a predetermined portion of the shield wire 11 of the wire harness 10 to be measured using screws 23x. Each plate member 23a and 23b has semi-cylindrical portions 23c and 23d, and a pair of flat portions 23e and 23f that extend outward from both ends of the semi-cylindrical portions 23c and 23d in cross-section. The pair of flat portions 23e of one plate member 23a each have screw insertion holes 23g, and the pair of flat portions 23f of the other plate member 23b each have screw holes 23h.

[0027] Then, the plate members 23a and 23b are positioned to cover the stripped portion of the sheath 15 of the shielded wire 11 from both sides. The plate members 23a and 23b are positioned to sandwich the shield member 14 along the entire axial direction of the semi-cylindrical portions 23c and 23d, and are attached to the shield member 14 in a press-fit state by fastening with screws 23x. In this way, as preparation for measurement, the plate members 23a and 23b are electrically connected to the shield member 14 of the shielded wire 11.

[0028] (Assembly of the measuring device 20 during measurement) As shown in Figure 4, the wire harness 10 with the contact jig 23 attached is inserted into and housed in the inner tube 22 during measurement. When the end cap 22b is screwed onto the tube body 22a, the contact jig 23 comes into contact with the front surface of the tube body 22a and the inner surface of the end cap 22b, so that the shielded wire 11 is held immovably inside the inner tube 22. The contact jig 23 is also electrically connected to the inner tube 22, so that the inner tube 22 and the shielding member 14 of the shielded wire 11 are electrically connected to each other via the contact jig 23. The connector 12 at the front of the wire harness 10 protrudes from the end cap 22b at the front of the inner tube 22. The base end of the wire harness 10 opposite to the connector 12 protrudes from the base end of the inner tube 22.

[0029] As shown in Figure 3, the inner tube 22, with the wire harness 10 housed inside, is housed in a manner that allows it to be inserted into the outer tube 21 during measurement. The outer tube 21 comprises a tube body 21a, a base end cap member 21b, and a tip cap member 21c. The base end cap member 21b is fixed to the base end of the tube body 21a of the outer tube 21 by screws or the like. The base end cap member 21b supports the base end of the inner tube 22, arranging the tube body 22a of the inner tube 22 and the tube body 21a of the outer tube 21 coaxially. The base end cap member 21b also electrically connects the inner tube 22 and the outer tube 21 by supporting the inner tube 22. The base end of the wire harness 10 is led out from the base end cap member 21b. The base end of the wire harness 10 is electrically connected to the input section 25 of the measuring device 20 during measurement.

[0030] A tip cap member 21c is fixed to the tip of the tube body 21a of the outer tube 21 by screws or the like. The tip cap member 21c is configured to support a terminal connection member 24 at a position in front of the tip of the inner tube 22 inside the outer tube 21. The terminal connection member 24 is detachable from the connector 12 of the wire harness 10 and is electrically connected to the wire harness 10 when mated with the connector 12. The detailed configuration of the terminal connection member 24 will be described later.

[0031] The tip cover member 21c is electrically connected to the measuring unit 26 of the measuring device 20 via the measuring cable 27 during measurement. Through the connection between the tip cover member 21c and the measuring unit 26, the tip cover member 21c is connected to the measuring unit 26, the outer tube 21, and the termination connection member 24, respectively. That is, the measuring unit 26 is connected to the shielding member 14 of the shielded wire 11 via the outer tube 21, the inner tube 22, and the contact jig 23, and is also connected to the communication lines 13a and 13b of the shielded wire 11 via the termination connection member 24 and the connector 12.

[0032] (Configuration of Termination Connection Member 24) As shown in Figures 6 and 7, the termination connection member 24 has a circuit board 24b on which a pair of termination resistors 24a are mounted, which are connected to the communication lines 13a and 13b of the wire harness 10 and function on the electrical circuit during measurement. The circuit board 24b is attached to the base member 24c. That is, the termination connection member 24 is attached to the end cap member 21c (see Figure 3) by the base member 24c. A connector 24d is attached to the base member 24c. The connector 24d is electrically connected to the circuit board 24b, that is, the terminals 24e of the connector 24d and the termination resistors 24a are electrically connected. During measurement, the connector 24d is connected to the connector 12 (see Figure 3) of the wire harness 10 to be measured and electrically connected to each other.

[0033] On the portion of the circuit board 24b where the termination resistors 24a are mounted, a conductive metal sheet 24x having a predetermined area to cover the pair of termination resistors 24a together is attached using an insulating resin adhesive sheet 24y having an equivalent area. The conductive metal sheet 24x is, for example, a copper sheet material. The insulating resin adhesive sheet 24y is, for example, an insulating resin sheet material with a polyimide resin base and adhesive layers on both sides. When attaching the conductive metal sheet 24x and the insulating resin adhesive sheet 24y, the insulating resin adhesive sheet 24y is first attached to the termination resistors 24a and the circuit board 24b so as to cover the termination resistors 24a, and then the conductive metal sheet 24x is attached on top of it. Alternatively, the conductive metal sheet 24x is first attached to the insulating resin adhesive sheet 24y, and then the insulating resin adhesive sheet 24y is attached to the termination resistors 24a and the circuit board 24b so as to cover the termination resistors 24a. Since the conductive metal sheet 24x and the insulating resin adhesive sheet 24y are flexible, they deform and adhere closely to the circuit board 24b, which includes a termination resistor 24a that protrudes slightly.

[0034] Furthermore, the insulating resin adhesive sheet 24y also functions as a dielectric. Therefore, by creating a structure in which the insulating resin adhesive sheet 24y is sandwiched between the circuit board 24b having a wiring layer 24f such as a ground and the conductive metal sheet 24x, the portion having the conductive metal sheet 24x and the insulating resin adhesive sheet 24y functions as a parasitic capacitor. Here, as the speed and frequency of the signal flowing through the termination resistor 24a of the termination connection member 24 and the circuit board 24b increase, the inductance component of the termination connection member 24 becomes more significant, and the characteristic impedance (CIDM) tends to worsen. This becomes particularly pronounced in the multi-gigabit band (2.5G / 5G / 10G) where the signal frequency exceeds 1 gigabit.

[0035] The measuring device 20 of this embodiment takes this into consideration and uses the conductive metal sheet 24x and the insulating resin adhesive sheet 24y as parasitic capacitors. In other words, the capacitance component of the parasitic capacitor cancels out the inductance component of the termination connection member 24, which acts to lower the impedance of the measuring circuit including the termination connection member 24. As a result, even when the object being measured is performing high-speed communication in the multi-gigabit band, measurement accuracy can be maintained and improved. Moreover, this can be achieved with simple additional processing, such as attaching the conductive metal sheet 24x and the insulating resin adhesive sheet 24y while using the existing termination resistor 24a.

[0036] (Operation of this embodiment) The operation of this embodiment will now be described. As shown in Figures 3 to 5, when measuring the shielding performance of the wire harness 10 to be measured using the measuring device 20, as a preliminary step, a contact jig 23 is attached to the shield wire 11 of the wire harness 10 so as to be electrically connected to the shield member 14. The wire harness 10 is housed in the inner tube 22 so as to be electrically connected to the contact jig 23 attached to it. The base end cover member 21b that supports the inner tube 22 is attached to the base end of the tube body 21a of the outer tube 21. The inner tube 22 is housed in the outer tube 21 and electrically connected to each other. At the tip of the outer tube 21, the connector 12 of the wire harness 10 and the termination connecting member 24 are connected.

[0037] As shown in Figures 6 and 7, for the termination connection member 24, a conductive metal sheet 24x is attached to the portion of the circuit board 24b where the termination resistor 24a is already mounted, using an insulating resin adhesive sheet 24y to cover the termination resistor 24a. When the communication speed of the wire harness 10 to be measured is in the multi-gigabit band, the capacitance component of the parasitic capacitor created by the conductive metal sheet 24x and the insulating resin adhesive sheet 24y is adjusted. In other words, the material, area, thickness, etc. of the conductive metal sheet 24x and the insulating resin adhesive sheet 24y are appropriately set so that the differential characteristic impedance is within the desired range.

[0038] The end cap member 21c, which supports the terminal connection member 24, is attached to the end of the tube body 21a of the outer tube 21. The wire harness 10 led out from the base end cap member 21b of the outer tube 21 is connected to the input section 25 of the measuring device 20, and the measuring cable 27 connected to the end cap member 21c is connected to the measuring section 26 of the measuring device 20.

[0039] Then, measurements are performed using the measuring device 20 shown in Figure 3, in accordance with well-known international standards. The wire harness 10 to be measured is, for example, one that is used for communication speeds in the multi-gigabit band. A predetermined measurement signal is injected into the communication lines 13a and 13b of the wire harness 10 from the input unit 25 of the measuring device 20. The injected measurement signal propagates through the communication lines 13a and 13b in the shielding member 14 of the shielded wire 11, and most of it is absorbed by the function of the electrical circuit of the termination connection member 24. On the other hand, a portion of the measurement signal leaks out as electromagnetic waves through the shielding member 14. The leaked electromagnetic waves propagate from the inner tube 22 to the outer tube 21, and are further input as a measurement signal from the outer tube 21 to the measuring unit 26. The measuring unit 26 measures the shielding performance of the wire harness 10 based on the measured value of the input measurement signal.

[0040] Figures 8 and 9 show an example of measurement results for a wire harness 10 including a termination connector 24. Figure 8 shows the measurement results related to the return loss (RL) of the transmission characteristics. The return loss indicates the amount of signal reflection that occurs when a high-frequency signal passes through the transmission path. In this embodiment (referred to as "the present invention" in the figures), which uses a conductive metal sheet 24x and an insulating resin adhesive sheet 24y, the measurement of the return loss can be performed accurately within a predetermined frequency range shown in the figures, particularly at multi-gigahertz frequencies. On the other hand, in conventional methods that do not use a conductive metal sheet 24x and an insulating resin adhesive sheet 24y, measurements at multi-gigahertz frequencies are not performed well. In other words, in this embodiment, where the parasitic capacitors of the conductive metal sheet 24x and the insulating resin adhesive sheet 24y are used to bring the differential characteristic impedance within a desired range, and impedance matching of the measurement circuit is properly performed, it is possible to improve the measurement accuracy. Furthermore, this can be improved by a simple measure of attaching a conductive metal sheet 24x and an insulating resin adhesive sheet 24y to the circuit board 24b so as to cover the termination resistor 24a.

[0041] Figure 9 shows the measurement results related to the transmission characteristic mode conversion (LCL: Longitudinal Conversion Loss). Mode conversion indicates the amount by which differential signals are converted to common-mode signals, and poor mode conversion indicates susceptibility to noise. The measurement results shown in Figure 9 are other transmission characteristic items related to Figure 8, and both this embodiment and conventional methods can accurately measure these items within the predetermined frequency range shown in the figure, especially in the multi-gigabit band.

[0042] (Effects of the present embodiment) Effects of the present embodiment will be described. (1) In the terminal connection member 24 used in the measuring device 20, an insulating resin adhesive sheet 24y is provided in close contact with the circuit board 24b so as to cover the terminal resistor 24a, and a conductive metal sheet 24x is provided in close contact with the insulating resin adhesive sheet 24y. The conductive metal sheet 24x and the insulating resin adhesive sheet 24y function as a parasitic capacitor. Therefore, the capacitance component of the parasitic capacitor cancels out the inductance component of the terminal connection member 24, which acts to lower the impedance of the measurement circuit. In other words, an improvement in measurement accuracy can be expected even for measurement objects in which the inductance component of the terminal connection member 24 affects measurement accuracy.

[0043] In particular, when the measurement object is the wire harness 10 for high-speed communication using a multi-gigahertz band signal frequency, the inductance component of the terminal connection member 24 cannot be ignored. Therefore, it is of great significance to cause the conductive metal sheet 24x and the insulating resin adhesive sheet 24y to function as a parasitic capacitor to lower the impedance of the measurement circuit. In other words, even for the wire harness 10 as a measurement object intended for high-speed communication, the measurement device 20 of the present embodiment can be sufficiently expected to improve measurement accuracy.

[0044] (2) The insulating resin adhesive sheet 24y is produced using an insulating resin sheet material having adhesive layers on both sides, and is affixed to each of the circuit board 24b and the conductive metal sheet 24x. That is, since the installation work for the insulating resin adhesive sheet 24y can be performed by affixation, the conductive metal sheet 24x and the insulating resin adhesive sheet 24y can be easily installed on the circuit board 24b.

[0045] (3) The insulating resin adhesive sheet 24y and the conductive metal sheet 24x are provided so as to collectively cover the pair of terminal resistors 24a. That is, since the installation work of the insulating resin adhesive sheet 24y and the conductive metal sheet 24x can be performed at one time, the conductive metal sheet 24x and the insulating resin adhesive sheet 24y can be easily installed on the circuit board 24b.

[0046] (4) The insulating resin adhesive sheet 24y and the conductive metal sheet 24x each have flexibility, and each deform and closely adhere when installed on the circuit board 24b including the terminating resistor 24a in a protruding configuration. That is, the conductive metal sheet 24x and the insulating resin adhesive sheet 24y can sufficiently function as a parasitic capacitor.

[0047] (Modified Example) The above embodiment can be modified and implemented as follows. The above embodiment and the following modified examples can be implemented in combination with each other within a technically consistent scope.

[0048] - The insulating resin adhesive sheet 24y is produced using an insulating resin sheet material having adhesive layers on both sides, but the present invention is not limited thereto. For example, the insulating resin adhesive sheet 24y may be installed using an adhesive patch prepared separately with an insulating resin sheet that does not have an adhesive layer.

[0049] - The insulating resin adhesive sheet 24y and the conductive metal sheet 24x are installed with an area that collectively covers a pair of terminating resistors 24a. However, the present invention is not limited thereto. For example, the insulating resin adhesive sheet 24y and the conductive metal sheet 24x may each be installed so as to individually cover the pair of terminating resistors 24a.

[0050] - The insulating resin adhesive sheet 24y and the conductive metal sheet 24x each deform and closely adhere by virtue of their own flexibility when installed on the circuit board 24b including the terminating resistor 24a in a protruding configuration. However, the present invention is not limited thereto. For example, a conductive metal sheet 24x preliminarily deformed in accordance with the protruding configuration of the terminating resistor 24a may be used.

[0051] - The pair of plate members 23a and 23b of the contact jig 23 are fastened to each other using the screw 23x, but the screw 23x may be fastened using a nut. In this case, by forming the screw hole 23h as the screw insertion hole 23g, the plate members 23a and 23b can have the same configuration. Further, a fastening member other than a screw may be used.

[0052] - In addition to the above, the configuration of the measuring device 20 may be changed as appropriate. - This disclosure encompasses the following embodiments. Note that, for the purpose of aiding understanding rather than being limiting, reference numerals representing components of embodiments are shown in parentheses in the following description.

[0053] (Note 1) A wire harness shielding performance measuring device (20) comprising: conductive metal tube members (21, 22) capable of housing the wire harness (10); conductive metal contact jig (23) that can be attached to the shield wire (11) of the wire harness and for electrically connecting the shield wire of the wire harness housed in the tube member to the tube member; a termination connection member (24) having a circuit board (24b) on which a termination resistor (24a) for impedance matching is mounted and electrically connected to the communication lines (13a; 13b) of the shield wire; an input unit (25) for supplying a measurement signal to the communication line; and a measurement unit (26) that measures the shielding performance of the wire harness by acquiring the leakage of electromagnetic waves to the shield member based on the supply of the measurement signal through the contact jig and the tube member. The terminal connection member (24) includes an insulating resin sheet (24y) provided in close contact with the circuit board so as to cover the terminal resistor, and a conductive metal sheet (24x) provided in close contact with the insulating resin sheet; the tube members (21, 22) include an outer tube (21) made of conductive metal and tubular in shape, and an inner tube (22) made of conductive metal, tubular in shape, having a smaller diameter than the outer tube, arranged coaxially inside the outer tube and electrically connected to the outer tube, into which the wire harness can be inserted; the contact jig (23) is attached to the shield wire (11) and electrically connected to the inner tube (22) and held immovably inside the inner tube; and the terminal connection member (24) is housed inside the outer tube (21) and electrically connected to the shield wire (11) at a forward position protruding from the tip of the inner tube (22), in a wire harness shielding performance measuring device.

[0054] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims, not in the sense described above, and all modifications within the sense and scope equivalent to the claims are intended.

[0055] 10 Wire harness 11 Shielded wire 12 Connector 13a Communication wire 13b Communication wire 13x Core wire 13y Insulation coating 14 Shielding member 14a Folded section 15 Sheath 20 Measuring device 21 Outer tube (tube member) 21a Tube body 21b Base end cap member 21c Tip cap member 22 Inner tube (tube member) 22a Tube body 22b End cap 22c Threaded section 22d Threaded section 23 Contact jig 23a Plate member 23b Plate member 23c Semi-cylindrical section 23d Semi-cylindrical section 23e Flat section 23f Flat section 23g Screw insertion hole 23h Threaded hole 23x Screw 24 Termination connection member 24a Termination resistor 24b Circuit board 24c Base member 24d Connector 24e Terminal 24f Wiring layer 24x Conductive metal sheet 24y Insulating resin adhesive sheet (insulating resin sheet) 25 Input section 26 Measurement section 27 Measurement cable x Gap

Claims

1. A wire harness shielding performance measuring device for measuring a wire harness using a shielded wire including a communication line and a shielding member provided on the outside of the communication line, the measuring device comprising: a conductive metal cylindrical tube member for housing the wire harness; a conductive metal contact jig attached to the shielded wire of the wire harness and electrically connected to the shielding member, and electrically connected to the tube member when the wire harness is housed in the tube member; a termination connection member having a circuit board on which a termination resistor for impedance matching is mounted and electrically connected to the communication line of the shielded wire; an input unit for injecting a measurement signal into the communication line of the shielded wire; and a measuring unit for measuring the shielding performance of the wire harness by acquiring the leakage of electromagnetic waves from the shielded wire to the shielding member based on the injection of the measurement signal through the contact jig and the tube member. The terminal connection member comprises an insulating resin sheet provided in close contact with the circuit board so as to cover the terminal resistor, and a conductive metal sheet provided in close contact with the insulating resin sheet, wherein the device is configured to measure the shielding performance of a wire harness.

2. The wire harness shielding performance measuring device according to claim 1, wherein the insulating resin sheet is made of an insulating resin adhesive sheet having adhesive layers on both sides, and the termination connection member is made by attaching the insulating resin sheet to the circuit board and the conductive metal sheet, respectively.

3. The wire harness shielding performance measuring device according to claim 1, wherein the termination connecting member is provided with a pair of termination resistors, and the insulating resin sheet and the conductive metal sheet are configured to cover the pair of termination resistors together.

4. The wire harness shielding performance measuring device according to claim 1, wherein the insulating resin sheet and the conductive metal sheet are each flexible, and the termination connecting member is configured such that the insulating resin sheet and the conductive metal sheet adhere closely to the circuit board, which includes the termination resistor having a protruding configuration, as they deform.

5. The wire harness shielding performance measuring device according to claim 1, wherein the wire harness to be measured is used for high-speed communication using multi-gigabit band signal frequencies.

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