JP2015138586A - cable clamp and cable clamp connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable favorable transmission of an electronic signal while reducing the number of processes with a simple configuration when mounted onto a co-axial cable.SOLUTION: Pressure-welding blades 12a are provided that cut and proceed from outside to inside of an outer covering 24 of a co-axial cable 20 to contact with an external conductor 23 of the co-axial cable 20 in shield contact portions 12 in contact with the external conductor 23. A contact end marginal part with the external conductor 23 in the pressure-welding blade 12a is made to be an arc shape along the outer peripheral shape of the external conductor 23. Thus, a pretreatment process such as pre-cutting of the outer covering 24 of the co-axial cable 20 becomes unnecessary, enabling efficient work. Uniformity of distance between an internal conductor 21 and the external conductor 23 is kept, favorably maintaining characteristic impedance and the like.

Description

  The present invention relates to a cable clamp and a cable clamp connection structure that perform ground connection by being attached to an intermediate portion of a coaxial cable.

  In recent years, it has become important to improve ground characteristics and EMI (electromagnetic wave interference) characteristics as the frequency of transmission signals used in various electronic devices such as cellular phones or electric devices increases. From this point of view, a countermeasure is often adopted in which a cable clamp is attached to the middle portion of the coaxial cable to perform ground connection. For example, in the cable clamp connection structure in which the conventional cable clamp 1 shown in FIG. 12 is attached to the coaxial cable 2, the outer sheath 2 a of the coaxial cable 2 is attached as shown in FIG. The shield barrel portion 1a of the cable clamp 1 is attached by plastic deformation such as caulking to the outer conductor 2b exposed at the portion where the outer covering 2a is removed. Next, on both sides of the shield barrel portion 1a, each of the pair of jacket barrel portions 1b and 1b is covered by plastic deformation such as caulking so as to cover the outer sheath 2a of the coaxial cable 2 from the outer side. Installing. The cable clamp 1 mounted on the coaxial cable 2 in this way is connected to the wiring board side (not shown) so that a ground circuit is formed.

  As described above, when the conventional cable clamp 1 is mounted, it requires a step of cutting and removing the outer sheath 2a of the coaxial cable 2 in advance and a step of plastically deforming the shield barrel portion 1a and the jacket barrel portion 1b. The number of manufacturing processes tends to increase, and improvement in productivity is demanded.

  In order to solve such problems of the conventional cable clamp, it is considered that a pressure contact blade that cuts into the outer sheath of the coaxial cable as shown in Patent Documents 1 and 2 below is adopted for the cable clamp. It is done. For example, as shown in FIG. 14, a pair of press contact blades 1 c, 1 c facing each other is provided on the shield barrel portion 1 a attached to the coaxial cable 2, and both the press contact blades 1 c, 1 c are The outer sheath 2a of the coaxial cable 2 is cut from the outer side so as to enter the inside, and both the press contact blades 1c, 1c are brought into contact with the outer conductor 2b of the coaxial cable 2, so that the outer portion of the coaxial cable 2 is contacted. In this configuration, the conductor 2b and the cable clamp 1 are grounded.

  A cable clamp having such a press contact blade improves productivity, but in the configuration in which the press contact blade is simply cut into the outer sheath of the coaxial cable, the external conductor is moved by the press contact blade entering the inside. It will be crushed into an ellipse shape, and the outer conductor will be elongated in the vertical direction as shown in FIG. If such deformation occurs in the outer conductor, the distance from the center conductor becomes non-uniform in the circumferential direction, and electrical characteristics such as characteristic impedance and reflection characteristics are degraded, resulting in a decrease in electrical characteristics. Signal transmission may become unstable.

JP-A-11-135164 JP 2005-332632 A

  Therefore, the present invention provides a cable clamp and a cable clamp connection structure that can perform electrical signal transmission satisfactorily while reducing the number of steps when mounting to a coaxial cable with a simple configuration. The purpose is to provide.

  In order to achieve the above object, the present invention is formed from a plastically deformable conductive member that is connected to a ground portion by being attached to a middle portion of the coaxial cable. A jacket barrel portion that is mounted so as to be wound from the outer side, and a shield contact portion that is integrally formed so as to be adjacent to the jacket barrel portion in the axial direction of the coaxial cable and contacts an outer conductor of the coaxial cable The shield contact portion is provided with a pressure contact blade that cuts inwardly from the outside of the outer sheath of the coaxial cable and contacts the outer conductor of the coaxial cable. The contact edge portion of the press contact blade with the outer conductor forms an arc shape along the outer peripheral shape of the outer conductor. It is.

  According to the present invention having such a configuration, when the cable clamp is attached to the coaxial cable, the coaxial cable is pressed against the pressure contact blade of the shield contact portion so that the pressure contact blade of the shield contact portion is Since the outer sheath enters the interior as if it is torn and is in electrical contact with the outer conductor, a pre-processing step such as pre-cutting the outer sheath of the coaxial cable is unnecessary, and the efficiency is increased accordingly. Work becomes possible.

  Further, according to the present invention having the above-described configuration, the outer conductor has the press contact blade of the shield contact portion in a state along the outer peripheral shape of the outer conductor after the cable clamp is mounted. The original circular cross-sectional shape is maintained, and the deformation of the outer conductor is reduced, so that the uniformity of the distance between the inner conductor and the outer conductor is maintained. As a result, characteristic impedance, reflection characteristics, etc. The signal transmission characteristics can be maintained satisfactorily and can be adjusted so as to have the necessary signal transmission characteristics.

  Furthermore, in the present invention, it is desirable that an engagement portion that protrudes or is recessed in the radial direction of the coaxial cable is provided at a contact edge portion of the press contact blade with the outer conductor.

  According to the present invention having such a configuration, the engagement portion provided at the contact portion of the press contact blade engages with the external conductor, whereby the electrical contact with the external conductor is improved and the engagement portion By appropriately adjusting the shape or position of the outer conductor, the shape of the outer conductor is adjusted, and the distance between the inner conductor and the outer conductor is appropriately adjusted in the circumferential direction so that the inner conductor and Signal transmission characteristics such as characteristic impedance and reflection characteristics determined by the distance to the external conductor are required.

  Furthermore, in the present invention, the shield contact portion having the press contact blade can be provided adjacent to one or both sides in the axial direction of the coaxial cable with respect to the jacket barrel portion, and The jacket barrel portion may be provided adjacent to both sides in the axial direction of the coaxial cable with respect to the shield contact portion having the press contact blade.

  Furthermore, in the present invention, the above-described cable clamp can be configured to be grounded via a clip member mounted on a wiring board.

  As described above, the present invention is a coaxial cable integrally formed so as to be adjacent in the axial direction of the coaxial cable with respect to a jacket barrel portion that is mounted so as to be wound around the outer sheath of the coaxial cable. The shield contact portion that contacts the outer conductor of the cable is provided with a pressure contact blade that cuts inward from the outside of the outer sheath of the coaxial cable and contacts the outer conductor of the coaxial cable, and the pressure contact blade contacts the outer conductor. By making the end edge an arc shape along the outer peripheral shape of the outer conductor, it is possible to perform an efficient operation without requiring a process such as cutting the outer sheath of the coaxial cable in advance, and the outer conductor has The original annular cross-sectional shape can be maintained, and the uniformity of the distance between the inner and outer conductors can be maintained, and signal transmission characteristics such as characteristic impedance and reflection characteristics can be maintained. Since it is well maintained or can be adjusted to provide the required characteristics, electrical signals can be transmitted satisfactorily with a simple configuration while reducing the number of steps when mounting to a coaxial cable. Therefore, the reliability of the cable clamp and the cable clamp connection structure can be improved at a low cost.

It is an appearance perspective explanatory view showing the state where the cable clamp connection structure concerning one embodiment of the present invention was mounted on the wiring board. It is a plane explanatory view of the cable clamp connection structure shown in FIG. It is side surface explanatory drawing of the cable clamp connection structure shown in FIG. 1 and FIG. It is an external appearance perspective explanatory view showing the single-piece | unit structure of the cable clamp concerning one Embodiment of this invention used for the cable clamp connection structure shown in FIGS. 1-3. 4A and 4B show a single structure of a cable clamp according to an embodiment of the present invention shown in FIG. 4, where (a) is a front explanatory view, (b) is a side explanatory view, and (c) is a rear explanatory view. is there. FIG. 5 is a cross sectional explanatory view taken along line VI-VI in FIG. 3. It is an external appearance perspective explanatory view showing the state where the cable clamp connection structure which attached the cable clamp concerning one embodiment of the present invention to the coaxial cable was mounted on the wiring board via the clip. It represents the single-piece | unit structure of the cable clamp concerning other embodiment of this invention, (a) is front explanatory drawing, (b) is side explanatory drawing, (c) is back explanatory drawing. FIG. 7 is a cross-sectional explanatory view corresponding to FIG. 6 in a cable clamp connection structure according to still another embodiment of the present invention. FIG. 7 is a cross-sectional explanatory view corresponding to FIG. 6 in a cable clamp connection structure according to still another embodiment of the present invention. It represents the unitary structure of the cable clamp concerning other embodiment of this invention, Comprising: (a) is an external appearance perspective explanatory drawing, (b) is a front view, (c) is side explanatory drawing, (d) FIG. It is external appearance perspective explanatory drawing showing the conventional cable clamp connection structure. It is an external appearance perspective explanatory view showing the state where a part of outer coating was cut and removed from the coaxial cable used for the conventional cable clamp connection structure shown in FIG. It is a cross-sectional explanatory drawing showing the conventional example of the cable clamp connection structure which enabled efficient mounting | wearing of a cable clamp.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a cable clamp connection structure using a cable clamp according to the present invention will be described in detail with reference to the drawings.

  First, a cable clamp 10 according to an embodiment of the present invention shown in FIGS. 1 to 3 is attached to a middle portion of a coaxial cable 20 by plastic deformation such as caulking, and is a conductive member. The metal plate is formed by cutting and pressing. As described above, the cable clamp 10 is attached to the middle portion of the coaxial cable 20 so that the ground connection to the outer conductor of the coaxial cable 20 to be described later is performed.

  In the coaxial cable 20 to which the cable clamp 10 is mounted, as shown in FIG. 6 in particular, the outer conductor 23 for shielding is coaxially formed on the outer peripheral side of the central conductor 21 for signal transmission via a dielectric 22. In addition, an outer covering 24 made of an insulating material is disposed in a laminated manner on the outer peripheral side of the outer conductor 23 so as to cover the outermost peripheral portion of the entire cable.

  The cable clamp 10 attached to the coaxial cable 20 has a jacket barrel portion 11 attached so as to be wound around the outer sheath 24 of the coaxial cable 20 from the outer side, A pair of shield contact portions 12 and 12 are integrally formed so as to be adjacent to the jacket barrel portion 11 in the axial direction of the coaxial cable 20.

  Among them, the jacket barrel portion 11 has a connection bottom plate 11a which is placed on the land portion P1 formed on the wiring board P and soldered as shown in FIGS. 4 and 5 in particular. The coaxial cable 20 is placed so that the curved surface on the bottom side is received in an arc-shaped recess formed on the upper surface of the connection bottom plate 11a. In the present embodiment, for the sake of convenience of explanation, “upper / lower” refers to a direction away from the surface of the substrate P as an upper side and a direction closer to the upper side as a lower side.

  Further, the above-described connection bottom plate 11a is integrally formed so that the pair of fixing plates 11b and 11b extend in a blade shape obliquely upward so that the coaxial cable 20 received on the connection bottom plate 11a is sandwiched from both sides. Is formed. Both the fixing plates 11b and 11b are plastically deformed so as to be folded from above with respect to the coaxial cable 20 placed on the connection bottom plate 11a so as to follow the outer peripheral surface of the coaxial cable 20 as shown in FIG. Thus, it is deformed into a curved shape. The fixed plates 11b and 11b after plastic deformation so as to form the curved shape are fixed so as to be wound around the outer peripheral surface of the coaxial cable 20, and both end edges face each other close to each other. Placed in the state.

  Each of the pair of shield contact portions 12 and 12 adjacent to the jacket barrel portion 11 in the axial direction of the coaxial cable 20 extends from the connection bottom plate 11a of the jacket barrel portion 11 to one side of the fixed plate 11b. A portion having a width is formed from a claw-like member that branches in a bifurcated shape after integrally projecting along the extending direction of the coaxial cable 20. The pair of shield contact portions 12 and 12 made of such claw-shaped members are formed so as to rise substantially in parallel upward from the above-described wiring board P, and the shield contact portions 12 and 12 are both formed. The coaxial cable 20 is disposed so as to face the outer side of both sides in the radial direction.

  In these shield contact portions 12 and 12, press contact blades 12a and 12a for the outer sheath 24 of the coaxial cable 20 are formed at portions extending from the respective upper end portions to the opposite inner edge portions. These two press contact blades 12a, 12a are formed so as to cut the outer sheath 24 of the coaxial cable 20 from the outer side, and the coaxial cable 20 is located on the upper side with respect to the shield contact portions 12, 12. When descending from the facing state, the press contact blades 12a, 12a of both the shield contact portions 12, 12 are abutted against the lower side portion of the outer sheath 24 of the coaxial cable 20 and act upwardly. The both press contact blades 12 a and 12 a are configured to gradually enter a position above the coaxial cable 20 toward the inner side of the coaxial cable 20.

  The press contact blades 12a and 12a of the shield contact portions 12 and 12 that have entered the inner side of the coaxial cable 20 in this way are formed so as to form opposite edge portions as described above. The press contact blades 12a, 12a are in a positional relationship in contact with the outer conductor 23 of the coaxial cable 20 from the outer side. And the edge part where these both press contact blades 12a and 12a contact the outer conductor 23 of the coaxial cable 20 is formed so that the circular arc shape along the outer periphery shape of the outer conductor 23 of the coaxial cable 20 may be made.

  That is, as described above, the press contact blades 12a and 12a of the shield contact portions 12 and 12 that have entered the inner side of the coaxial cable 20 so as to tear the outer sheath 24 of the coaxial cable 20 are connected to the outer conductor 23 of the coaxial cable 20. The outer conductor 23 of the coaxial cable 20 is electrically connected to the cable clamp 10 via both shield contact portions 12 and 12.

  The cable clamp 10 thus attached to the coaxial cable 20 is mounted on the land portion P1 of the wiring board P by solder bonding, and a ground circuit is formed between the cable clamp 10 and the coaxial cable 20 via the cable clamp 10. It has become so.

  According to this embodiment having such a configuration, when the cable clamp 10 is attached to the coaxial cable 20, the press contact blades 12a and 12a provided at the opposing edge portions of the pair of shield contact portions 12 and 12, The outer sheath 24 of the coaxial cable 20 enters from the outer side of the outer sheath 24 so as to cut inward, thereby making electrical contact with the outer conductor 23. A pre-processing step such as cutting in advance is not necessary, and the work can be efficiently performed correspondingly.

  In addition, after the cable clamp 10 is mounted, the press contact blades 12a, 12a provided at the opposing edges of the shield contact portions 12, 12 are arranged along the outer periphery of the external conductor 23, so that the external The deformation of the conductor 23 is reduced, the original circular shape is maintained, and the uniformity of the distance between the inner conductor 21 and the outer conductor 23 is maintained, so that signal transmission characteristics such as characteristic impedance and reflection characteristics are maintained. Can be maintained satisfactorily and can be adjusted to have the necessary signal transmission characteristics.

  In the above-described embodiment, the cable clamp 10 is directly solder-bonded to the wiring board P, and the mounting is performed. However, as illustrated in FIG. It is also possible to employ a configuration in which a clip member 30 formed of a metal plate made of a conductive member is soldered on the formed land portion P <b> 1 and the cable clamp 10 is fitted to the clip member 30. .

  According to such an embodiment, since the cable clamp 10 is securely clamped by the clip member 30, the coaxial cable 20 is more stably fixed, and the joint surface of the clip member 30 to the land portion P1 is provided. Can sufficiently secure the connection reliability. Furthermore, since the coaxial cable 20 is not directly soldered, it is easy to detach and improve the maintainability.

  Further, the shield contact portion 12 of the cable clamp 10 in the above-described embodiment is arranged so as to be adjacent to only one side in the axial direction of the coaxial cable 20 with respect to the jacket barrel portion 11, but is shown in FIG. As shown, the pair of shield contact portions 12 and 13 may be arranged symmetrically with respect to the jacket barrel portion 11 so as to be adjacent to both sides in the axial direction of the coaxial cable 20. . Also in such an embodiment, the same operation and effect as the above-described embodiment can be obtained, and contact reliability can be improved by contacting at multiple points.

  On the other hand, in another embodiment according to FIG. 9 in which the same reference numerals are given to the same constituent members as those in the above-described embodiment, the opposite edge portions of both shield contact portions 12, 12, that is, the outer conductor of the coaxial cable 20. Engagement convex portions 12b and 12b projecting toward the center in the radial direction of the coaxial cable 20 are provided at the upper and lower portions of the press contact blades 12a, which are electrical contact portions with respect to 23, respectively.

  If such a configuration is adopted, the engagement convex portions 12b and 12b provided at the contact portion of the press contact blade 12a of each shield contact portion 12 are engaged with the external conductor 23, whereby the electrical contact with the external conductor 23 is achieved. Contact is improved. Further, by appropriately adjusting the shape or position of the engaging protrusions 12b, 12b, the shape of the outer conductor 23 is adjusted, and the distance between the inner conductor 21 and the outer conductor 23 is set in the circumferential direction. By appropriately adjusting, signal transmission characteristics such as characteristic impedance and reflection characteristics determined by the distance between the inner conductor 21 and the outer conductor 23 are required.

  Furthermore, in another embodiment shown in FIG. 10, the upper edges of the press contact blades 12a and 12a, which are the opposite edge portions of the shield contact portions 12 and 12, that is, the electrical contact portions with respect to the outer conductor 23 of the coaxial cable 20, In addition to the lower portion, engagement concave portions 12c and 12c that are recessed toward the radially outer side of the coaxial cable 20 are provided in the center portion.

  Even in such a configuration, the engagement recesses 12c and 12c provided in the contact portions of the press contact blades 12a and 12a of the shield contact portions 12 and 12 engage with the external conductor 23, so that the electrical contact with the external conductor 23 is achieved. As a result, the shape of the external conductor 23 is adjusted, and the distance between the internal conductor 21 and the external conductor 23 is adjusted in the circumferential direction, whereby the internal conductor 21 and the external conductor are adjusted. Electrical characteristics such as characteristic impedance and reflection characteristics determined by the distance to the terminal 23 are required.

  On the other hand, in the cable clamp 40 according to the embodiment shown in FIG. 11, a pair of jacket barrel portions 41a and 41b arranged in parallel in the axial direction of the coaxial cable 20 are arranged so as to form a predetermined interval. Between the pair of jacket barrel portions 41a and 41b, a pair of shield contact portions 42 and 42 are disposed so as to face each other so as to sandwich the coaxial cable 20 from both outer sides in the radial direction. That is, the pair of jacket barrel portions 41 a and 41 b provided in the present embodiment are provided so as to be adjacent to both sides in the axial direction of the coaxial cable 20 with respect to the shield contact portion 42. Similarly to the above-described embodiment, the press contact blade 42a that cuts from the outer side to the outer sheath 24 of the coaxial cable 20 is provided.

  At this time, one of the shield contact portions 42, 42 described above is integrally projected in the axial direction from the connection bottom plate of the jacket barrel portion 41a disposed on one side in the extending direction of the coaxial cable 20. Although formed, the other shield contact portion 42 is formed so as to integrally project from the jacket barrel portion 41 b disposed on the other side in the extending direction of the coaxial cable 20. The lower end portions of both shield contact portions 42, 42 are integrally connected by a common connecting plate 42b, and both shield contacts are made to rise upward from a position spaced apart by a predetermined distance in the common connecting plate 42b. The parts 42 and 42 are provided.

  In the embodiment having such a configuration, both side portions of the shield contact portion 42 are held by the pair of jacket barrel portions 41 a and 41 b in the extending direction of the coaxial cable 20. Even when such an external force is applied, the holding force of the pair of jacket barrel portions 41a and 41b reduces the influence on the contact property of the shield contact portion 42 with respect to the coaxial cable 20, so that electrical Stability related to secure connectivity is improved.

  As mentioned above, although the invention made by the present inventor has been specifically described based on the embodiment, the present embodiment is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  For example, the present invention is not limited to the single-core coaxial cable as in the above-described embodiment, and can be similarly applied to coaxial cables and the like arranged in a multipolar shape.

  As described above, the present embodiment can be widely applied to a wide variety of cable clamps used in various electric devices.

DESCRIPTION OF SYMBOLS 10 Cable clamp 11 Jacket barrel part 11a Connection bottom plate 11b Fixed plate 12 Shield contact part 12a Press contact blade 12b Engagement convex part 12c Engagement recessed part 13 Shield contact part 20 Coaxial cable 21 Central conductor 22 Dielectric 23 External conductor 24 Outer coating P Wiring Substrate P1 Land part 30 Clip member 40 Cable clamp 41a, 41b Jacket barrel part 42 Shield contact part 42a Pressure contact blade 42b Connecting plate

Claims (5)

It is formed from a plastically deformable conductive member that performs ground connection by being attached to the middle part of the coaxial cable,
A jacket barrel portion mounted so as to be wound from the outer side with respect to the outer sheath of the coaxial cable;
A shield contact portion formed integrally with the jacket barrel portion so as to be adjacent to the axial direction of the coaxial cable and in contact with the outer conductor of the coaxial cable;
In cable clamps with
The shield contact portion is provided with a pressure contact blade that cuts inwardly from the outside of the outer sheath of the coaxial cable and contacts the outer conductor of the coaxial cable,
A cable clamp, wherein a contact edge portion of the press contact blade with the outer conductor is formed in an arc shape along an outer peripheral shape of the outer conductor.   The cable clamp according to claim 1, wherein an engagement portion protruding or recessed in a radial direction of the coaxial cable is provided at a contact end edge portion of the press contact blade with the outer conductor.   The cable clamp according to claim 1, wherein a shield contact portion having the press contact blade is provided adjacent to one or both sides in the axial direction of the coaxial cable with respect to the jacket barrel portion.   The cable clamp according to claim 1, wherein the jacket barrel portion is provided so as to be adjacent to both sides in the axial direction of the coaxial cable with respect to the shield contact portion having the press contact blade.   A cable clamp and a cable clamp connection structure, wherein the cable clamp according to any one of claims 1 to 4 is configured to be grounded via a clip member mounted on a wiring board.

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