JP2011096450A - Insulating sheet for screw terminal of electric apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulating sheet for a screw terminal of an electric apparatus which can respond with easy winding work to a screw terminal section of the electric apparatus and can reuse the insulating sheet by easily removing it at the time of maintenance and inspection and is easy to use at low cost. <P>SOLUTION: In the insulating sheet for a screw terminal of electric apparatus, a screw engagement hole 6a fitted to a tip of the shaft section of a terminal screw 4 engaged with a terminal piece 1a of the electric apparatus 1 is drilled at a starting end side of the insulating sheet 6 punched in a band-shape, a projecting engagement pawl section 6b for keeping the insulating sheet at a winding state and an engagement groove 6c for inserting the engagement pawl section are formed on a sheet surface of an intermediate section and a terminal end section along the longitudinal direction, the insulating sheet 6 is wound around the circumference of a wiring connection section by hooking the engagement hole 6a to the terminal screw 4, and the insulating sheet is kept at a winding state by inserting the engagement pawl section 6b to the engagement groove 6c at a terminal end. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In this invention, electric wires are connected to screw terminals for external wiring of various electrical devices such as switches and instrument transformers that are installed and used in switchboards and control panels of low-voltage distribution systems. The present invention relates to an insulating sheet that is wound around the wiring connection portion in a state to ensure insulation.

  First, a general external wiring connection structure of the head electrical device is shown in FIGS. 6 (a) and 6 (b). In the figure, 1 is an electric device, 2 is a mounting plate for the electric device 1 installed in the panel, and 3 is an electric wire for external wiring connected to the electric device 1. Here, a terminal screw 4 is screwed to each of the terminal pieces 1a on the power source side and the load side arranged in a line on the left and right sides from the case of the electric device 1, and when the electric wire 3 is wired, As is well known, a crimping terminal 3a attached to the tip of 3 is inserted into the terminal screw 4 and fastened with a nut 4a. In addition, as shown in FIG. 7, the bar conductor 5 laid in the panel may be connected to the terminal screw 4 instead of the electric wire 3 shown in FIG.

In this case, in the state where the electric wire 3 is connected to the terminal portion of the electrical equipment 1, an insulating material is used around the wiring connection portion as a preventive measure for preventing an electric shock and preventing a short circuit between the terminals due to the contact of foreign matter. In this case, since the screw terminal structure has irregularities such as terminal screws 4 and nuts 4a screwed on the terminal piece 1a, normal insulation is provided. Since the taping operation for winding the tape is difficult, various insulation methods as described below have been proposed and adopted as alternative means.
(1) An insulating cover of a molded product made of plastic or the like previously molded corresponding to the external shape of the screw terminal portion is fitted so as to cover the screw terminal portion and the crimp terminal of the electric wire.
(2) A putty-like insulating material in which a resin adhesive and a curing agent are mixed on site is applied to the outer surface of the wiring connection portion.
(3) Adopt a heat shrinkable tube.
(4) In addition, the soft rubber sheet is folded in half and covered with the wiring connection portion, and the periphery of the sheet is hooked and fixed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-299062

By the way, the above-described conventional method for insulating a wiring connection portion has the following problems in terms of cost and workability.
(1) Since the applicable size and shape of the insulating cover to be a molded product are limited, it is necessary to prepare a variety of products corresponding to the terminal shape and size of various electric devices, which increases costs.
(2) Putty-like insulating material takes time to apply, and it is necessary to remove the putty each time maintenance such as maintenance and inspection of electrical equipment, change of wiring, etc., and to repaint the putty for repair. .
(3) Although heat-shrinkable tubes can be obtained at a relatively low cost, the heat-shrinking work to be applied to the wiring connection part requires a heat source such as a torch, and there is a problem that the working place is limited. The tube must be cut and cannot be reused.
(4) Furthermore, the hook structure of the soft rubber sheet disclosed in Patent Document 1 has a limited number of parts because the shape of applicable electrical equipment is limited and a dedicated hook is required for fixing the sheet. In addition to the high cost, the installation work is also troublesome.

  The present invention has been made in view of the above points, and its purpose is to secure insulation by winding a wire connection portion in which an external conductor is connected to a terminal screw with a dedicated jig and a simple manual operation that does not require skill. We provide a low-cost and easy-to-use insulation sheet for screw terminals of electrical equipment that can be used and that can be easily removed and reused during maintenance such as maintenance and inspection of electrical equipment and changes in external wiring. There is.

In order to achieve the above object, an insulating sheet according to the present invention has a screw engagement hole that is fitted to the tip of a shaft portion of a terminal screw provided in a terminal portion of an electrical device on the start end side of a sheet punched into a strip shape. In addition, the sheet surface of the intermediate portion and the end portion along the longitudinal direction is formed by forming a projection-shaped engagement claw portion that holds the sheet in a wound state, and an engagement groove into which the engagement claw portion is inserted. (Claim 1) The detailed structure can be configured in the following manner.
(1) Radial cut grooves are formed at a plurality of peripheral portions of a screw engagement hole drilled on the starting end side of the insulating sheet.
(2) A plurality of engagement grooves are formed on the terminal side of the insulating sheet by shifting the position in the longitudinal direction.

  According to the above-described insulating sheet of the present invention, in the state in which the external conductor is wired to the screw terminal portion of the electrical equipment, the screw engaging hole drilled on the starting end side of the sheet is wound around the wiring connection portion. By fitting and engaging with the tip, it is possible to surround the terminal screw and the crimp terminal of the electric wire connected thereto, and to wind the insulating sheet around the wiring connection portion by a simple manual operation. The insulating sheet can be easily kept in the wound state by inserting the engaging claw portion formed in the middle of the sheet into the engaging groove formed at the end of the wound insulating sheet. In addition, the insulating sheet can be easily punched out of a soft rubber sheet or a soft plastic sheet using a simple mold called a so-called bi-molding mold, and can be manufactured at a low cost.

  In addition, by forming a notch groove on the periphery of the screw engagement hole, it is possible to handle terminal screws of different diameters, and in the state where the starting end of the insulating sheet is fitted to the screw shaft of the terminal screw. The peripheral edge of the engagement hole meshes with the screw groove of the terminal screw, preventing the insulation sheet from falling off and shifting. Furthermore, by forming a plurality of engagement grooves by shifting the position in the longitudinal direction on the terminal end side of the insulating sheet, the winding length of the insulating sheet can be adjusted according to the outer size of the wiring connection portion. .

It is a perspective view showing the state just before winding the insulation sheet by the Example of this invention around the screw terminal part of an electric equipment. FIG. 2 is a detailed structural diagram of the insulating sheet in FIG. 1, (a) is a plan view, and (b) and (c) are enlarged views of an A portion and a B portion in FIG. It is explanatory drawing of the winding procedure of the insulating sheet in FIG. 1, and is a perspective view showing the state which latched the start end of the insulating sheet on the terminal screw of the electric equipment. FIG. 4 is a perspective view of a state where an insulating sheet is wound around a wiring connection portion and fastened from the state of FIG. 3. It is an enlarged view showing the winding state of the insulating sheet in FIG. It is a figure of the electric equipment which connected the electric wire to the screw terminal part, (a) is a perspective view, (b) is a side view of the principal part in (a). It is a perspective view of the electric equipment which connected the bar conductor to the screw terminal part.

  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 to the member corresponding to FIG. 6, and the description is abbreviate | omitted.

  In this embodiment, the crimp terminal 3a attached to the electric wire 3 of the external wiring is fastened to the terminal piece 1a of the electric device 1 via the terminal screw 4 and the nut 4b, and the wiring connection portion is surrounded by the present invention. The insulation sheet 6 is wound to ensure insulation.

  Next, the detailed structure of the insulating sheet 6 is shown in FIGS. This insulating sheet 6 is produced by punching from a soft rubber sheet or soft plastic sheet using a so-called die-cut mold, and at the starting end (winding start side) of the insulating sheet 6 punched into a strip shape, An engagement hole (round hole) to be fitted to the tip of the screw shaft of the terminal screw 4 is drilled. Further, a projecting engagement claw portion 6b for fastening the insulating sheet in a wound state is provided at an intermediate portion along the longitudinal direction of the sheet, and a plurality of engagement claw portions 6b are inserted at the end (winding end side). An engagement groove 6c is formed (punching with a mold). Further, the hole diameter of the engagement hole 6a corresponds to the screw diameter of the terminal screw 4 (one diameter smaller than the screw diameter). Further, as shown in FIG. A radial cut groove 6a-1 is formed. In addition, the dotted line represented on the insulating sheet 6 of FIG. 2 represents the corner crease | fold when the said insulating sheet was wound around the terminal part of the electric equipment 1 as a virtual line.

  Next, an operation procedure for winding the insulating sheet 6 around the wiring connection portion of the electric device 1 will be described with reference to FIGS. First, the engagement hole 6a drilled at the starting end of the insulating sheet 6 is fitted into the tip of the screw shaft of the terminal screw 4 and hooked at this position. In this case, since the cut groove 6a-1 is formed in the peripheral edge of the engagement hole 6a, the peripheral edge of the expanded engagement hole 6a can be engaged with the screw groove of the terminal screw 4 and easily fall off. Absent.

  Next, as shown in FIGS. 4 and 5, the crimping terminal 3a of the electric wire 3 connected to the terminal piece 1a, the terminal screw 4 and the nut 4a are surrounded by the insulating sheet on the outer periphery of the screw terminal portion. 6 is wound, and the insulation groove 6c is inserted into the engagement claw portion 6b erected from the intermediate portion of the sheet to keep the insulating sheet 6 in the wound state. Complete. Thereafter, the insulating sheet 6 is wound around the terminal portion of the other pole in the same procedure as described above to ensure the insulation of the wiring connection portion.

  As can be seen from the above-described winding operation procedure, the insulating sheet 6 can be wound by a simple manual operation without requiring a special jig or high skill. In addition, the wound insulating sheet 6 can be easily removed from the wiring connecting portion by removing the terminal engaging groove 6c from the engaging claw portion 6b. Even during maintenance, the insulating sheet 6 once removed can be reused. In the illustrated embodiment, as an application example of the insulating sheet 6, the case where the electric wire 3 with the crimp terminal is connected to the terminal of the electric device 1 has been described, but the application is similarly applied to the bar conductor 5 shown in FIG. 7. Of course you can.

DESCRIPTION OF SYMBOLS 1: Electrical equipment 1a: Terminal piece 3: Electric wire 3a: Crimp terminal 4: Terminal screw 4a: Nut 6: Insulation sheet 6a: Engagement hole 6a-1: Cut groove 6b: Engagement claw part 6c: Engagement groove

Claims (3)

  An insulation sheet that secures insulation by connecting an external conductor to a wiring screw terminal of an electrical device and securing the insulation by surrounding it around the wiring connection portion. A screw-engagement claw portion for perforating a screw engagement hole to be fitted to the front end of the portion, and retaining the insulating sheet in a wound state at the intermediate portion along the longitudinal direction and the sheet surface of the end portion, and the engagement An insulating sheet for a screw terminal of an electrical device, wherein an engagement groove into which a claw portion is inserted is cut out.   The insulating sheet according to claim 1, wherein radial cutting grooves are formed at a plurality of peripheral portions of a screw engaging hole drilled on a starting end side of the insulating sheet.   The insulating sheet according to claim 1, wherein a plurality of engaging grooves are formed in the terminal end side of the insulating sheet by shifting the position in the longitudinal direction.

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