Cable with bush and method for inspecting the same

Abstract

To provide a cable with a bush and its inspection method capable of inspecting an adhesion state by non-destructive inspection.SOLUTION: A cable 5 with a bushing includes a cable 5a and a bushing 9 made of a non-magnetic material bonded and fixed to an outer peripheral surface of the cable 5a so as to cover a part of the cable 5a in a longitudinal direction, and the bushing 9 is bonded and fixed by a magnetic powder-containing adhesive 95 in which magnetic powder is dispersed in an adhesive as a base.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a bushed cable and an inspection method thereof. [Background technology]

[0002] Conventionally, there has been known a bushed cable in which a bush is provided around the cable to protect the portion of the cable extending from a terminal component such as a connector or a sensor head (see, for example, Patent Document 1). The bush is provided at the end of the cable so as to cover the periphery of the cable, and is adhered and fixed to the outer surface of the cable using an adhesive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-110888 Summary of the Invention [Problem to be solved by the invention]

[0004] In a cable with a bushing, there is a demand for inspecting the adhesive bonding condition (i.e., the state of application or filling of the adhesive) to confirm whether the bushing is firmly adhered to the cable. However, with conventional cables with a bushing, inspecting the bonding condition requires destructive testing.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a bushed cable and an inspection method therefor that enable inspection of the bonding state by non-destructive inspection. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides a bushed cable comprising a cable and a bush made of a non-magnetic material that is adhesively fixed to the outer surface of the cable so as to cover a portion of the cable in the longitudinal direction, wherein the bush is adhesively fixed with a magnetic powder-containing adhesive in which magnetic powder is dispersed in a base adhesive.

[0007] Furthermore, in order to solve the above-mentioned problems, the present invention provides a method for inspecting a bushed cable, the bushed cable comprising a cable and a bushing adhesively fixed to the outer surface of the cable so as to cover a portion of the cable in the longitudinal direction, the bushing being adhesively fixed with a magnetic powder-containing adhesive having magnetic powder dispersed in a base adhesive, the method comprising: a magnetization step of magnetizing the magnetic material; and a measurement step of measuring the strength of the magnetic field produced by the magnetized magnetic material at each position of the adhesively fixed portion of the bushing using a magnetic sensor. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a bushed cable and an inspection method therefor that allow the adhesive state to be inspected by non-destructive inspection. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a configuration diagram showing an ultrasonic probe using a bushed cable according to an embodiment of the present invention as a probe cable, and a device main body that constitutes an ultrasonic diagnostic device in combination with this ultrasonic probe. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] 1A and 1B are enlarged views of the vicinity of the bush of a bushed cable, where (a) is a plan view, (b) is a cross-sectional view taken along line AA in (a), and (c) is a cross-sectional view taken along line BB in (b). [Figure 5]10(a) and 10(b) are diagrams illustrating a method for inspecting a cable with a bushing. [Figure 6] FIG. 10 is a diagram illustrating a method for setting a threshold value. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Embodiment Mode] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the embodiment described below, a bushed cable 5 according to the present embodiment will be described as a probe cable for an ultrasound diagnostic device 1. However, the present invention is not limited to this, and can be applied to any bushed cable 5 having a bush 9 adhesively fixed thereto. Furthermore, the probe cable described below is merely one example of a bushed cable 5, and its specific structure can be modified as appropriate.

[0011] (Ultrasound diagnostic device 1) FIG. 1 is a diagram showing an ultrasonic probe 2 using a bushed cable 5 according to this embodiment as a probe cable, and a device main body 10 that constitutes an ultrasonic diagnostic device 1 in combination with this ultrasonic probe 2.

[0012] The ultrasound diagnostic device 1 is used by doctors and clinical laboratory technicians to diagnose subjects, and comprises a device main body 10 and an ultrasound probe 2. The device main body 10 performs processing to form ultrasound images and displays the ultrasound images on a display 100. The ultrasound probe 2 comprises a probe 3 having an ultrasound transmitting and receiving surface 3a, a probe connector 4 that fits into a main body side connector 101 provided on the device main body 10, and a bushed cable 5 that connects the probe 3 and the probe connector 4.

[0013] A gel-like ultrasound jelly is applied to the body surface of the subject, and the ultrasound transmitting and receiving surface 3a of the probe 3 is pressed against the area where the ultrasound jelly has been applied. The ultrasound waves transmitted from the ultrasound transmitting and receiving surface 3a are reflected inside the subject's body and received by the ultrasound transmitting and receiving surface 3a. The received ultrasound waves are converted into electrical signals and sent to the device main body 10 via the bushed cable 5 and the probe connector 4. The device main body 10 forms an ultrasound image based on this electrical signal and displays it on the display 100. The probe 3 and the probe connector 4 correspond to terminal members provided at the end of the bushed cable 5.

[0014] (Bushed Cable 5) The bushed cable 5 includes a cable 5a and a bush 9 made of a non-magnetic material that is adhesively fixed to the outer circumferential surface of the cable 5a so as to cover a portion of the cable 5a in the longitudinal direction. Each part will be described in detail below.

[0015] (Cable 5a) Fig. 2 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of cable 5a. As shown in Fig. 2, cable 5a includes a cable core 50 including a plurality of signal lines 51, a pressure wrapping tape 6 that is pressure wrapped around the outer periphery of cable core 50, a braided shield 7 that covers the outer periphery of the pressure wrapping tape 6, and a sheath 8 that covers the outer periphery of the braided shield 7.

[0016] Fig. 3 is a cross-sectional view showing one signal line 51 used in cable 5a. As shown in Fig. 3, signal line 51 is a coaxial line having an inner conductor 511, an outer conductor 512, an insulator 513 between inner conductor 511 and outer conductor 512, and a jacket 514 covering the outer periphery of outer conductor 512. The frequency of the electrical signal transmitted by signal line 51 is, for example, several MHz to several tens of MHz. Cable core 50 includes a large number of signal lines 51, for example, 100 or more.

[0017] The multiple signal wires 51 that make up the cable core 50 are bundled together by a pressure winding tape 6. The pressure winding tape 6 is a strip made of resin such as polyimide, and is spirally wound so that portions of the tape overlap in the width direction. The braided shield 7 is formed by braiding multiple wires 71, for example, made of tin-plated copper wire, in a lattice pattern. The sheath 8 can be made of, for example, polyvinyl chloride (PVC) or silicone rubber, and more preferably, soft polyvinyl chloride, which has been made more flexible by adding a plasticizer.

[0018] (Bush 9) 4A to 4C are enlarged views of the vicinity of the bushing 9 of the bushed cable 5, where (a) is a plan view, (b) is a cross-sectional view taken along line AA in (a), and (c) is a cross-sectional view taken along line BB in (b). As shown in FIGS. 4A to 4C, the bushing 9 is provided so as to cover the outer periphery of the sheath 8 at at least one of both longitudinal ends of the cable. In this embodiment, a bushing 9 is provided at each of both longitudinal ends of the cable. The bushing 9 is a reinforcing member for improving bending durability by suppressing breakage of the signal wire 51 and cracks in the sheath 8 caused by bending the bushed cable 5 at a small radius of curvature or interference with the housing of a terminal member.

[0019] The bushing 9 has a flange portion 91a, and the bushing 9 is fixed to the terminal member (probe 3 or probe connector 4 in this case) by engaging the flange portion 91a with the housing of the terminal member (probe 3 or probe connector 4) provided at the end of the cable. Then, the multiple signal wires 51 exposed from the sheath 8 at the tip of the cable 5a extend into the terminal member (probe 3 or probe connector 4). Hereinafter, the side of the bushing 9 from which the multiple signal wires 51 extend (the right side in FIG. 4(a)) will be referred to as the tip side, and the side from which the sheath 8 extends (the left side in FIG. 4(a)) will be referred to as the base side.

[0020] The bushing 9 integrally comprises a body 91 made of resin, at least a portion of which is disposed outside the terminal member (the probe 3 or the probe connector 4), and a substantially cylindrical base 92 integrally provided on the distal end of the body 91 (the end from which the signal lines 51 extend). The base 92 is made of a non-magnetic metal material or a resin material. The flange 91a is provided on the distal end of the body 91 so as to protrude radially outward. The body 91 is tapered so that its thickness decreases toward the base end (the farther it is from the terminal member), and its rigidity (i.e., the force required to deform it) decreases with increasing distance from the terminal member.

[0021] In this embodiment, the sheath 8 is folded back at its tip portion onto the outer periphery of the base portion 92, and this folded back portion 8a is fastened and fixed to the base portion 92 by a fixing band 94. Also, in this embodiment, a stopper (rubber stopper) 93 is inserted into the bushing 9 from the tip side (the side from which the multiple signal wires 51 extend) to restrict movement of the signal wires 51 at the connection portion (for example, the soldered portion). The stopper 93 is a member that is pressed into the bushing 9 to sandwich the signal wires 51 between the inner wall 9a of the bushing 9 and the stopper 93, thereby restricting movement of the signal wires 51 in the cable longitudinal direction.

[0022] The stopper 93 integrally includes a rubber insertion portion 931 that is inserted into the bushing 9 and clamps the signal lines 51 between itself and the inner wall 9a of the bushing 9, and a support portion 932 that is integrally formed with the insertion portion 931, supports the insertion portion 931, and secures the insertion portion 931 to the bushing 9. The insertion portion 931 is formed in a generally conical shape and is made of solid rubber such as urethane rubber. The support portion 932 is formed by bending a rectangular metal plate. The support portion 932 has a central portion 932a to which the insertion portion 931 is secured, and a pair of securing portions 932b that are bent 90° at both ends of the central portion 932a toward the insertion side of the insertion portion 931 and secured to the base portion 92 of the bushing 9, forming an overall U-shape.

[0023] The structure of the bushing 9 shown in the figure is merely an example, and the mouthpiece 92 and the stopper 93 are not essential and can be omitted. In other words, the bushing 9 does not have to have a structure in which the sheath 8 is crimped.

[0024] In the bushing cable 5 according to this embodiment, the bushing 9 is bonded and fixed with a magnetic powder-containing adhesive 95. The magnetic powder-containing adhesive 95 is a base adhesive in which magnetic powder (magnetic powder) is dispersed. As described in detail below, the magnetic powder is magnetized (see FIG. 5(a)) and the magnetic sensor 97 detects the strength of the magnetic field (magnetic flux density) generated by the magnetized magnetic powder (see FIG. 5(b)). This allows the application or filling state of the magnetic powder-containing adhesive 95 to be detected, thereby enabling easy and nondestructive inspection of the adhesive state of the bushing 9. Furthermore, by bonding and fixing the bushing 9 with the magnetic powder-containing adhesive 95, the magnetic powder-containing adhesive 95 functions as a ferrite core, thereby improving electrical characteristics. This makes it possible to omit or downsize (reduce the number of ferrite cores used), thereby miniaturizing the entire bushing cable 5 and making it easier to handle. Adjusting the application thickness (amount) of the magnetic powder-containing adhesive 95 or the magnetic powder content also makes it possible to adjust the characteristic impedance. The electrical properties can also be adjusted by selecting the type of magnetic powder used. When applying to an ultrasonic probe operating at a frequency band of several MHz, it is preferable to use Ni-Zn magnetic powder, which has low loss even at high frequencies and does not generate heat easily.

[0025] As the base adhesive used for the magnetic powder-containing adhesive 95, it is advisable to take into consideration the materials of the sheath 8 and the bushing 9 and use an adhesive that has high adhesiveness to the sheath 8 and the bushing 9. For example, if the sheath 8 is made of silicone rubber, a silicone-based adhesive or the like can be used.

[0026] Furthermore, ferrite powder can be used as the magnetic powder used in the magnetic powder-containing adhesive 95. This allows the magnetic powder-containing adhesive 95 to function as a substitute for or supplement the ferrite core, improving electrical characteristics or adjusting impedance, etc. However, if the magnetic powder content is too low, the adhesive state cannot be detected and the electrical characteristics cannot be sufficiently improved. On the other hand, if the magnetic powder content is too high, the adhesive effect is reduced, making the bushing 9 more likely to peel off. Therefore, the magnetic powder content in the magnetic powder-containing adhesive 95 should be 25 vol% to 70 vol%. Furthermore, the average particle size of the magnetic powder should be 0.1 μm to 10 μm, taking into account factors such as ease of dispersion and application. Here, the "average particle size" in this specification refers to a particle size measured by a laser diffraction scattering method. The magnetic powder may be surface-treated to enhance adhesion with the base adhesive. For example, when a silicone-based adhesive is used as the base, the magnetic powder may be subjected to a silane coupling treatment. The surface treatment method may be appropriately selected taking into consideration the adhesive that serves as the base.

[0027] The magnetic powder-containing adhesive 95 can be applied, for example, by placing the bushing 9 around the cable 5a, inserting an injection needle into the gap between the sheath 8 of the cable 5a and the bushing 9, and then using a syringe or the like to pump the magnetic powder-containing adhesive 95 into the gap. In this case, although the amount of the magnetic powder-containing adhesive 95 pumped in can be controlled, it is difficult to visually confirm whether the magnetic powder-containing adhesive 95 has spread throughout the entire gap between the sheath 8 and the bushing 9. Therefore, the adhesion state is inspected using the method described below.

[0028] (Inspection method for bushed cables 5) 5(a) and (b) are diagrams illustrating a method for inspecting a bushed cable 5. First, as shown in Fig. 5(a), a magnetizing member 96 such as a permanent magnet or electromagnet is brought close to the bushing 9 to magnetize the magnetic material (magnetic powder) contained in the adhesive 95 containing magnetic powder. At this time, it is preferable to move the magnetizing member 96 along the cable longitudinal direction and rotate the bushed cable 5 while magnetizing, thereby magnetizing the magnetic material (magnetic powder) contained in the adhesive 95 containing magnetic powder evenly.

[0029] Thereafter, as shown in FIG. 5( b), a magnetic sensor 97 such as a Hall element is used to measure the strength of the magnetic field generated by the magnetized magnetic material at each position of the adhesively fixed portion of the bushing 9. At this time, the magnetic sensor 97 is moved along the cable longitudinal direction, and the magnetic field strength is measured while the bushed cable 5 is rotated. If the magnetic field strength measurement results in a portion where the magnetic field strength is lower than a preset threshold, it is determined that there is a portion where the magnetic powder-containing adhesive 95 has not spread thoroughly, and a sufficient adhesive state has not been achieved. In this way, according to this embodiment, the adhesive state of the bushing 9 can be inspected nondestructively.

[0030] Here, the threshold value can be set by the following method. FIG. 6 is a diagram illustrating the threshold value setting method. As shown in FIG. 6, first, a first sheet 111 made of the same material as the bushing 9 and a second sheet 112 made of the same material as the sheath 8 are prepared. The first sheet 111 and the second sheet 112 are each a rectangular sheet with a thickness of approximately 1 mm, a width of 25 mm, and a length of 80 mm. These sheets 111 and 112 are bonded together with a magnetic powder-containing adhesive 95 to create a threshold value setting sample 110. At this time, the bonding area bonded with the magnetic powder-containing adhesive 95 is set to, for example, 10 mm x 25 mm. These steps are repeated to create threshold value setting samples 110 with various amounts of magnetic powder-containing adhesive 59 applied.

[0031] Thereafter, for each of the prepared threshold setting samples 110, the strength of the magnetic field generated by the magnetized magnetic material is measured at each position in the adhesive region using the magnetizing member 96 and the magnetic sensor 97. The tensile shear strength of the threshold setting samples 110 whose magnetic field strength has already been measured is then measured. Specifically, the tensile shear strength is measured by holding both ends of the threshold setting sample 110 and pulling it in the direction of the arrow in FIG. 6 at a speed of 500 mm / min. The relationship between the obtained magnetic field strength and the tensile shear strength is then plotted, and the magnetic field strength that results in the desired tensile shear strength is set as the threshold.

[0032] In the example of Figures 5(a) and (b), magnetization is performed using the magnetizing member 96, and then measurement is performed using the magnetic sensor 97. However, measurement using the magnetic sensor 97 may also be performed while a magnetic field is being applied using the magnetizing member 96.

[0033] (Actions and Effects of the Embodiments) As described above, in the bushing cable 5 according to this embodiment, the bushing 9 is bonded and fixed with the magnetic powder-containing adhesive 95, which is a base adhesive in which magnetic powder is dispersed. This allows the magnetic powder contained in the magnetic powder-containing adhesive 95 to be magnetized and the strength of the magnetic field generated by the magnetized magnetic powder to be measured, thereby enabling nondestructive testing of the adhesive state of the bushing 9. Furthermore, because the magnetic powder-containing adhesive 95 serves as a substitute for or supplement to the ferrite core, it is possible to omit or reduce the number of ferrite cores used, thereby reducing the overall size of the bushing cable 5 and making it easier to handle. For example, when the bushing cable 5 is used as a medical cable, this offers the significant benefit of making it easier to handle in tight spaces. Furthermore, the characteristic impedance can be adjusted by adjusting the thickness of the magnetic powder-containing adhesive 95 applied.

[0034] (Variation) Although not mentioned in the above embodiment, the magnetic powder-containing adhesive 95 may be spread over the outer circumferential surface of the cable 5a in addition to the adhesive portion of the bushing 9. That is, the bushed cable 5 may further have a coating layer formed by applying the magnetic powder-containing adhesive 95 to the outer circumferential surface of the sheath 8 in the portion where the bushing 9 is not provided. This makes it possible to adjust electrical characteristics such as characteristic impedance over a wider range, and it is also possible to achieve good electrical characteristics even if a ferrite core is omitted.

[0035] Although not mentioned in the above embodiment, a thermosetting resin may be used as the base adhesive of the magnetic powder-containing adhesive 95. In this case, an external magnetic field may be applied to heat the magnetic powder, thereby promoting hardening of the adhesive. This results in stronger adhesive strength.

[0036] Furthermore, in the above embodiment, the case where the main body 91 of the bushing 9 is made of resin has been described, but the main body 91 may be made of a non-magnetic metal such as copper.

[0037] (Summary of the embodiment) Next, the technical ideas grasped from the above-described embodiments will be described by using the reference numerals and the like in the embodiments. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiments.

[0038] [1] A bushed cable (5) comprising a cable (5a) and a bush (9) made of a non-magnetic material adhesively fixed to the outer surface of the cable (5a) so as to cover a portion of the cable (5a) in the longitudinal direction, the bush (9) being adhesively fixed with a magnetic powder-containing adhesive (95) in which magnetic powder is dispersed in a base adhesive.

[0039] [2] The bushed cable (5) according to [1], wherein the magnetic powder is made of Ni-Zn magnetic powder.

[0040] [3] A method for inspecting a bushed cable (5), the bushed cable (5) comprising a cable (5a) and a bush (9) adhesively fixed to the outer surface of the cable (5a) so as to cover a portion of the cable (5a) in the longitudinal direction, the bush (9) being adhesively fixed with a magnetic powder-containing adhesive (95) in which magnetic powder is dispersed in a base adhesive, the method comprising: a magnetization step of magnetizing the magnetic body; and a measurement step of measuring the strength of the magnetic field generated by the magnetized magnetic body at each position of the adhesively fixed portion of the bush (9) using a magnetic sensor (97).

[0041] (Addendum) Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the above-described embodiments. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention. Furthermore, the present invention can be appropriately modified and implemented within the scope of its spirit. [Explanation of symbols]

[0042] 5...Bushed cable 5a...cable 9. Bush 95...Magnetic powder adhesive 96...Magnetic member 97...Magnetic sensor

Claims

1. Cable and a bushing made of a non-magnetic material adhesively fixed to the outer circumferential surface of the cable so as to cover a portion of the cable in the longitudinal direction, The bushing is bonded and fixed with a magnetic powder-containing adhesive, which is a base adhesive in which magnetic powder is dispersed. Cable with bushing.

2. The magnetic powder is made of Ni-Zn magnetic powder.

2. The bushed cable according to claim 1.

3. 1. A method for inspecting a bushed cable, comprising: The bushed cable is Cable and a bushing adhesively fixed to the outer circumferential surface of the cable so as to cover a portion of the cable in the longitudinal direction, The bushing is bonded and fixed with a magnetic powder-containing adhesive, which is a base adhesive in which magnetic powder is dispersed, a magnetization step of magnetizing the magnetic body; a measuring step of measuring the strength of the magnetic field generated by the magnetized magnetic body at each position of the adhesively fixed portion of the bushing using a magnetic sensor, Inspection method for bushed cables.

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