Method and device for compressing a cylindrical sleeve for wire strand

Description

TECHNICAL FIELD

The present invention relates to a method and device for compressing a cylindrical sleeve on a stranded wire, the cylindrical sleeve being used for terminal insertion connecting portion of a power meter, a switch, etc.

PRIOR ART

Conventionally, there are two types of electrical wire connections: a direct connection and a terminal insertion connection. The use of such two types of connections depends on the receiving side electrical devices. For the terminal insertion connection, in particular, stranded wire requires a soldering operation to unify the tip portion of the wire. However, since this operation accompanies heat, the work efficiency is poor, thus providing an increased contact surface area between the wire and the sleeve.

The conventional cylindrical sleeve has a small contact surface area with a stranded wire, and thus it has some problems. The cylindrical sleeve tends to fall off easily when tipped downward during the sleeve crimping operation that impedes the operation, and it has difficulty of removal for later maintenance and repairs.

Therefore, it is desirable to develop a stranded wire sleeve that matches the outer dimensions and shape of a stranded wire while increasing the contact surface area between the stranded wire and the sleeve, and it is further desirable to develop a stranded wire sleeve that has a good work efficiency and has a low electrical resistance.

However, development of a sleeve that matches the outer shape of a stranded wire is fraught with problems, including a large amount of development costs and time, and it further requires mass production for profitability.

Also, a reference document for conventional models of crimping devices (crimping pliers) include a patent application filed for an invention in which the crimping portion of a crimping device is removable to accommodate a plurality of sleeve types. However, problems remain with workability, affordability, durability, etc. (For example, see Patent Document 1.)

[Patent Reference 1] Japanese Patent Application Laid-Open (Kokai) No. 2000-133401

DISCLOSURE OF INVENTION PROBLEM THE INVENTION IS TO SOLVE

Therefore, in order to solve the problems described above, the present invention develops and provides a stranded wire cylindrical sleeve compression method and a compression device in which a conventional cylindrical sleeve is fitted on a stranded wire, and the outer circumference of the cylindrical sleeve is compressed to the outer circumferential surface of a stranded wire.

MEANS TO SOLVE THE PROBLEM

As a means for solving the problem, the compression device is comprised of a pair of handles and a pair of jaws operated by the pair of handles, and a center portion of the pair of jaws are provided with a plurality of types of pairs of compression portions that have a predetermined width and match a cross-sectional outer circumferential shape of a stranded wire so as to be used for a plurality of cylindrical sleeve sizes; wherein with a use of the compression portion of the compression device, an entire outer circumference of the cylindrical sleeve is compressed to fully close a gap between the stranded wire and the cylindrical sleeve for full contact with each other, thus providing an increased contact surface between the sleeve and the stranded.

EFFECT OF THE INVENTION

The effect of the present invention is to improve work efficiency and to enable an effective connecting method with low electrical resistance by using a conventional cylindrical sleeve as a method for securing a stranded wire, matching the outer circumference of the sleeve to the outer circumferential surface of stranded wire, and compressing the cylindrical sleeve, thus fully closing a gap between the stranded wire and the cylindrical sleeve for full contact with each other and providing an increased contact surface area between the wire and the sleeve.

Also, in addition to the key points for electrical wire connection, which are to increase work speed and reliability, this is solid and superior in mechanical strength and electrical strength, simplifies detachability at the time of maintenance and repair, and contributes to a reduction of electrical fires. Thus, the improved workability, durability, and safety provide an extremely beneficial effect.

BEST MODE FOR CARRYING OUT THE INVENTION

The preferred mode of present invention, when determined based on electrical resistance, is to compress such that the gap between the stranded wire and sleeve are minimized. However, when determined based on maintenance and repair workability, the narrower the gap, the worse the workability. Therefore, the preferred mode would be a compression method and a compression device which enable appropriate compression while taking into consideration both electrical resistance and workability.

Embodiment 1

Next, one embodiment of the present invention is described in detail according to FIG. 1 through FIG. 4. When a stranded wire to be connected to a terminal insertion connecting portion of a power meter of an such as a power meter or a switch is compressed via a cylindrical sleeve (S), the stranded wire (SL) is pinched and compressed with an intersecting compression device (1) formed by opposing compression grooves that match the cross-sectional outer circumferential shape of the stranded wire (SL), to compress and secure the stranded wire (SL) and the sleeve (S).

Also, a compression device for a cylindrical sleeve (S) for a stranded wire to be connected to terminal insertion connecting portions of a power meter or a switch, etc., comprises a compression device (1) characterized by being provided with a pair of handles (2), and being provided with a pair of jaws (3) operated by said pair of handles (2), and having a center portion of said pair of jaws (3), being provided with a plurality of types of pairs of compression portions (4) having a predetermined width (W) and matching a stranded wire (SL) cross-sectional outer circumferential shape, and, made used for a plurality of cylindrical sleeve (S) sizes, and with a use of the compression portion (4) of said compression device (1), compressing the entire outer circumference of the cylindrical sleeve (S), to fully close a gap between the stranded wire (SL) and the cylindrical sleeve (S) for full contact with each other, thus providing an increased contact surface area between the wire and the sleeve.

Next, a general summary is given regarding the compression device (1) parts composition and operation principle. The parts composition, as shown in FIGS. 1(A) and (B), can be generally categorized into a pair of handles (2) and a pair of jaws (3). The handles (2) can be opened and shut symmetrically on the left and right, centered on the axis portion (1a). Approximately center of the handles, a compression force adjustment device (2a) is provided, comprising a mechanism by which the handles are compressed with a specified force and, upon reaching the specified value, the handles automatically return to the open position. Meanwhile, at the center of the pair of jaws (3), pairs of compression portions in three sizes (4a) (4b) (4c) are provided. Said compression portions (4a) (4b) (4c) are respectively formed symmetrically left and right to match the cross-section shape of each stranded wire, comprising a mechanism by which, when the pair of handles (2) are compressed in the closing direction, the pair of compression portions (4) on the jaws (3) close to compress a sleeve.

Next, the sleeve compression method will be described. First, FIG. 3(A) shows the relationship between the stranded wire (SL), cylindrical sleeve (S), and compression device (1) before sleeve compression. (B) shows the relationship of the stranded wire (SL), a cylindrical sleeve (S′), and the compression device (1) after sleeve compression. The cylindrical sleeve (S) length is about 20 mm, and the width of the compression portions (4) on the compression device (1) is about 12 mm. Therefore, the compression portion (4) on the compression device (1) is used to fully compress the entire outer circumferential surface in two moves. Doing so will fully close a gap between the stranded wire (SL) and the cylindrical sleeve (S) for full contact with each other, thus providing an increased contact surface area between the wire and the sleeve.

Also, the compression portion 4 of the compressor 1 is separated into three types: a small-size compression portion 4a, a medium-size compression portion 4b, and a large-size compression portion 4c. These are used as appropriate for their usage. However, the compression portion sizes and number are not limited to three types, and they can be changed to meet the usage and purpose.

Also, FIG. 2(A) is an enlarged detailed view of portion “a” in FIG. 1(B), indicating said medium compression portion (4b). FIG. 2(B) is reference illustration, indicating the specifications of electrical wires used for the compression device, and lists the relationship between electrical wire size and compression inner diameter dimensions.

Then, a cylindrical sleeve (S) is compressed onto the end of a stranded wire (SL) for full contact with each other, which is then, for example, inserted into a terminal (Ma) of a watt-hour meter (M) as shown in FIG. 4, and secured by tightening a retaining screw (Mb).

POSSIBILITY OF INDUSTRIAL USE

The present invention improves workability, affordability, and safety, providing a stranded wire sleeve with low electrical resistance and high efficiency, and has potential for industrial use in contributing to terminal insertion connection work for a power meter or a switch, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] showing one embodiment of present invention, wherein (a) is a top view of the compression device, and (b) is a front view.

[FIG. 2] showing one embodiment of present invention, wherein (a) is an enlarged detailed view of portion “a” in FIG. 1(b), and (b) is reference illustration, indicating specifications of electrical wires used for the compression device (list of electrical wire sizes and compression inner diameter dimensions).

[FIG. 3] showing a usage example of present invention, wherein (a) is a status drawing before sleeve compression, and (b) is a status drawing after sleeve compression.

[FIG. 4] showing a usage example of present invention, and it is an isometric drawing of a watt-hour power meter wire insertion connecting method.