JP2013098509A - Cable clamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable clamp having its structure improved so as to improve operability of screwing of a wiring cable.SOLUTION: There is provided a cable clamp 4 for gripping and screwing a wiring cable such as a shield cable 3 to a housing frame of equipment. A clamp body thereof has a looped cable grip part 4a formed in a center region of a strip sheet made of conductive metal, and fitting seat pieces 4b, 4c extending from the cable grip part 4a to both sides and having fitting holes 4b-1, 4c-1 bored. While the cable 3 is run through the cable grip part 4a and gripped with fitting seat pieces 3b and 3c placed thereupon, the cable 3 is screwed to the frame of the equipment by inserting fitting screws 5 into the fitting holes. The one fitting seat piece 4c has a guide wall part 4d raised along right and left side edges thereof, and restriction and holding are achieved with the fitting seat pieces 4b and 4c put one over the other.

Description

  The present invention relates to a structure of a cable clamp that is applied to, for example, an inverter device and grips a wiring cable such as a shielded cable wired inside the device housing and is screwed to a housing frame.

  In electronic devices such as inverter devices, a shielded cable is used for the signal cable wired inside the housing as a measure against EMC and noise, and the shield layer (the braided wire tube) of the cable is used as a metal housing frame. A cable clamp in which a shield cable is held by a conductive clamp and screwed to a housing frame is widely used as a grounding means (for example, Patent Document 1). reference).

  Here, taking an inverter device as an example, a grounding support structure for a wiring cable using the clamp is shown in FIGS. In each figure, 1 is a casing frame (made of metal) of the inverter device, 2 is a terminal block for connecting cables, 3 is a shielded cable connected to the terminal block 2 and wired inside the casing, and 4 is a cable clamp. The cable clamp 4 is gripped so as to hold the shielded cable 3 and is screwed to the housing frame 1 via an attachment screw 5.

  Next, the conventional structure of the cable clamp 4 will be described with reference to FIGS. That is, the cable clamp 4 is made by punching from a flexible steel sheet having a plate thickness of about 0.6 to 0.8 mm, for example, and the clamp body has a loop-shaped cable gripping portion 4a at the central portion of the strip-shaped sheet. The mounting seats 4b and 4c extending from the cable gripping portion 4a to both sides thereof are provided with mounting holes 4a-1 and 4b-1 through which the mounting screws 5 are passed.

  When the shield cable 3 is screwed to the housing frame 1 (see FIG. 4), the work procedure includes a shield layer 3a of the cable 3 passed through the clamp 4 and a cable gripping portion 4a for gripping the shield layer 3a. After adjusting the loop shape of the cable gripping portion 4a while applying a tightening force so as to be in close contact with each other, the mounting seat pieces 4b and 4c extending from the cable gripping portion to both sides are superposed vertically, and the mounting seat in this cable gripping state. The mounting holes 4b-1 (long holes) and 4c-1 (round holes) drilled in the pieces 4b and 4c are screwed to the housing frame 1 through the mounting screws 5. As shown in the figure, various shielded cables 3 having different thicknesses are provided by making the mounting hole 4b-1 drilled in one of the mounting seat pieces 4b and 4c into a long hole and the other mounting hole 4c-1 into a round hole. Can also be supported.

Japanese Utility Model Publication No. 6-31183

  By the way, the cable clamp 4 having the conventional structure described above is pushed so that the cable gripping portion 4a of the cable clamp 4 is in close contact with the peripheral surface of the cable by external tightening pressure when the shield cable 3 is gripped and screwed. When the bending is adjusted, the one mounting seat piece 4c may be laterally displaced in the direction of arrow P in FIG. 5B relative to the other mounting seat piece 4b due to the force applied at that time. As a result, in a state where both the mounting seat pieces 4b and 4c are overlapped, the positions of the mounting holes 4b-1 and 4c-1 do not match correctly, and there is a problem that hinders the insertion of the mounting screw 5. For this reason, conventionally, this is dealt with by re-adjusting the shape of the cable gripping portion 4a. However, the adjustment work takes time and the workability and work efficiency of cable wiring deteriorate.

  In addition, the cable clamp 4 having the conventional structure described above has a round hole shape corresponding to the size of the mounting bolt 5 in the mounting seat piece 4c as a mounting hole for drilling the mounting seat pieces 4b and 4c and passing the mounting screws 5 therethrough. The mounting hole 4c-1 is perforated, and the other mounting seat piece 4b is perforated with an elongated hole-shaped mounting hole 4b-1, so that various cables having different thicknesses can be accommodated.

  However, if one of the mounting holes is a long hole, when the tightening force of the mounting screw 5 is loosened or an external force is applied to the cable 3, the mounting seat piece 4b is within the longitudinal direction of the long hole 4b-1. As a result, the conductivity between the cable gripping portion 4a and the shield layer 3a of the cable 3 decreases, the grounding resistance to the shield cable 3 increases, and noise countermeasures are taken. May not function properly.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an improved cable clamp that can solve the above-described problems and improve the workability of screwing the wiring cable and the reliability of the support function. To provide a structure.

In order to achieve the above object, according to the present invention, a cable clamp that grips a wiring cable such as a shielded cable and is screwed to a housing frame of a device, the strip body of which the clamp body is a conductive metal A loop-shaped cable gripping portion formed at the central portion of the cable, and a mounting seat piece extending from the cable gripping portion on both sides and having a mounting hole drilled, and passing the wiring cable through the cable gripping portion. In the state where the cables are overlapped with each other, the mounting holes are screwed through the mounting screws,
On one of the mounting seat pieces, a fence-like guide wall portion is formed upright along the left and right edges to restrain and hold the other mounting seat piece in the overlapping position.

  Further, in the above-described configuration, one mounting seat piece extending on both sides of the cable gripping portion is provided with a round hole-shaped mounting hole at one position on the tip side thereof, and the other mounting seat piece in the longitudinal direction thereof. A round hole-shaped attachment hole is drilled at a plurality of locations along the line (claim 2).

According to said structure, there can exist the following effect.
First, with respect to the mounting seat pieces formed on both ends of the cable clamp main body, a fence-shaped guide wall is formed upright along the left and right side edges of one mounting seat piece in advance. Due to the restraint, both the mounting seat pieces are held at positions that face each other in a parallel posture.

  Therefore, when adjusting the loop shape according to the thickness of the cable by applying a tightening force to the cable gripping part in the work of screwing the wiring cable to the housing frame using the cable clamp as described above, Securely prevent the behavior that was problematic in the conventional structure where the other mounting seat piece is displaced laterally relative to one mounting seat piece, and smoothly screw the mounting screw through the mounting hole. As a result, workability and work efficiency can be improved.

  In addition to the above-described configuration, one mounting seat piece extending on both sides of the cable gripping portion is provided with a round hole-shaped mounting hole at one point on the tip side, and the other mounting seat piece has its longitudinal length. By drilling mounting holes with round holes at multiple locations along the direction, the mounting screws may be loosened or the cable may be subjected to external forces in use after the cable clamp that holds the distribution cable is screwed to the housing frame of the device. Can prevent the occurrence of problems that the mounting seat piece is displaced in the longitudinal direction and the cable clamping force is reduced as in the conventional structure, especially shielded cables as a measure against EMC and noise. When using, the reliability of the grounding support can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a structural diagram of the cable clamp concerning Example 1 of this invention, (a) is an external perspective view, (b) is a side view of the state which hold | gripped the cable, (c) is the arrow view X- in (b). It is an expanded sectional view of X. It is a structural diagram of the cable clamp concerning Example 2 of this invention, (a) is an external perspective view of a clamp, (b) is a development view of the clamp. It is an external appearance perspective view of the state which screwed the cable clamp to the housing | frame with the inverter apparatus as an example. FIG. 4 is an enlarged plan view of a state where a cable wired inside the housing of FIG. 3 is held by a cable clamp and screwed to the housing frame. FIGS. 3A and 3B are conventional structural views of a cable clamp applied to FIGS. 3 and 4, in which FIG. 3A is an external perspective view, and FIG. 3B is a perspective view illustrating a state when a wiring cable is gripped and screwed.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on the examples shown in FIGS. In addition, in the figure of an Example, the same code | symbol is attached | subjected to the same member corresponding to FIG. 5, and the description is abbreviate | omitted.

  First, the Example corresponding to the claim steel 1 of this invention is described based on Fig.1 (a)-(c). The cable clamp 4 of this embodiment is basically the same as the conventional structure shown in FIG. 3, but either one of the mounting seat pieces 4b and 4c extending from the cable gripping portion 4a (in the illustrated structure, the mounting seat piece 4c). ), A fence-like guide wall portion 4d that rises in an L shape is formed along the left and right edges toward the other mounting seat piece 4b. Here, the height of the guide wall portion 4d is equal to or greater than the plate thickness of the cable clamp 4. As a result, the mounting seat piece 4b overlying the mounting seat piece 4c is restrained and held between the guide wall portions 4d as shown in FIG. 1C, and is always positioned so as to correctly overlap the mounting seat piece 4c. Will be.

  Therefore, after passing the shielded cable 3 through the cable clamp 4, the loop shape is adjusted by applying a tightening force to the cable gripping portion 4a from the outside so that the cable gripping portion 4a and the shield layer 3a of the cable 3 are in close contact with each other. In this case, even if the tightening force applied to the cable gripping portion 4a is slightly deviated, a relative lateral shift occurs between the mounting seat pieces 4b and 4c as described in the conventional structure (see FIG. 5B). It is not.

  Thereby, when screwing the cable clamp 4 to the housing frame 1 (see FIGS. 3 and 4) of the device through the mounting bolt 5, the mounting holes 4b-1 drilled in both mounting seat pieces 4b and 4c Since 4c-1 matches each other, the mounting bolt 5 can be smoothly passed through the mounting hole, and workability is improved.

Next, an embodiment corresponding to claim 2 of the present invention will be described with reference to FIGS.
That is, in the first embodiment, the mounting hole 4b-1 drilled in the mounting seat piece 4b of the cable clamp 4 is a long hole, whereas in the embodiment shown in FIG. 2, the mounting seat piece is used instead of the long hole. Mounting holes 4b-2, 4b-3, and 4b-4 having the same round hole shape as the mounting hole 4c-1 of the mounting seat piece 4c are drilled at a plurality of locations along the longitudinal direction of 4b.

  When the shielded cable 3 passed through the cable clamp 4 is gripped and screwed to the housing frame, any of the mounting holes 4b-2, 4b-3, 4b-4 so as to fit the thickness of the cable 3 is selected. These are selected and superimposed on the mounting hole 4c-1 of the mounting seat piece 4c, and in this state, the mounting bolt 5 is screwed to the housing frame.

  As a result, even when the mounting screw 5 is loosened or the external force is applied to the cable 3 while the shielded cable 3 is grounded and supported on the housing frame, the clamping force of the cable clamp 4 that grips the cable 3 is weakened. There is no fear that the degree of adhesion between 4a and the shield layer 3a of the cable 3 is reduced, and a stable ground support state can be maintained.

  In the first and second embodiments, the case where the shield cable 3 is screwed to the housing frame of the device as an application example of the cable clamp 4 has been described, but the wiring cable to which the cable clamp 4 is applied is a shield. The present invention is not limited to the cable 3 and can be applied to a normal wiring cable in which a core wire is covered with an insulating material.

1 Equipment frame 3 Shielded cable (distribution cable)
3a Shield layer 4 Cable clamp 4a Cable gripping part 4b, 4c Mounting seat 4b-1-4b-4, 4c-1 Mounting hole 4d Guide wall 5 Mounting bolt

Claims (2)

A cable clamp for gripping a wiring cable and screwing it to a housing frame of a device, a loop-shaped cable gripping portion formed at a central portion of a strip-shaped sheet whose clamp body is a conductive metal, and the cable gripping portion A mounting seat piece extending from both sides to which a mounting hole is perforated, and passing a wiring cable through the cable gripping portion and holding the mounting seat pieces in a cable gripping state. In what I tried to stop,
A cable clamp characterized in that a fence-like guide wall portion is formed upright on one of the mounting seat pieces so as to restrain and hold the other mounting seat piece in an overlapping position along its left and right side edges.   The cable clamp according to claim 1, wherein one mounting seat piece extending on both sides of the cable gripping portion is provided with a round hole-shaped mounting hole at one end thereof, and the other mounting seat piece is provided with the other mounting seat piece. A cable clamp, characterized in that round hole-shaped mounting holes are drilled at a plurality of locations along the longitudinal direction.