JP2003109682A - Threadless branch connector for electric wiring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate contact failure caused by deterioration over aging in a threadless branch connector for electric wiring. SOLUTION: Projecting shape parts 5 are provided as they are chamfers with guide function in the positions facing the spring piece tips of an electric wire terminal guide groove 11 of a conductive plate 3. Consequently, even if there is a bend of tolerance at an electric wire terminal 7, the contact position of the electric wire terminal 7 and conductive plate 3 is fixed to the projecting shape part 5 to prevent contact failure without moving. An electric wire terminal insertion port piece 10 is made of a material with moderately large creep property, and after the completion of work, elastic distortion left in the electric wire terminal 7 is absorbed by the creep property to deform the electric wire terminal insertion port piece 10 and to concentrate the pressing force of the spring piece on the contact pressure of the electric wire terminal 7 and conductive plate 3. Functional reliability can thereby be improved without impairing the conventional manufacturing cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a branch connector for electric wiring, and more particularly to a screwless branch connector for electric wiring that minimizes contact failure due to usage conditions.

[0002]

2. Description of the Related Art A conventional screwless branch connector is composed of a conductive plate and a spring piece arranged so as to sandwich an electric wire end, and the electric wire end is pressed against the conductive plate by the spring piece to obtain conductivity. . Since the conductive plate has a straight line shape or a corrugated plate shape parallel to the insertion direction of the wire end, if the wire end has a straight line shape, the pressing force of the spring piece will make contact with the end of the spring piece of the conductive plate at a position facing it. Conduct.

In the case of a screwless branch connector in which two spring pieces are provided for one wire end, the wire ends are brought into contact with the tips of the spring pieces of the conductive plate at positions facing each other due to the pressing force of each spring piece. And conduct.

[0004]

In general wiring work using the screwless branch connector (1), an electric wire is laid, the insulation coating of the electric wire is stripped at the branching portion, and the branch is made by connecting with the screwless branching connector. Wire end with bending (7)
The shape of is not an ideal straight line, and there is some degree of bending, and bending occurs even when a plurality of screwless branch connectors are bundled and housed in an insulating case. In addition, even after the construction work, bending occurs near the screwless branch connector due to maintenance and temperature changes. The screwless branch connector has a limit in setting the spring strength because it is in contact with the spring pressure and the wire end is inserted and removed while resisting the spring pressure. In addition, the screwless branch connector is reusable, the wire end may be pulled out, and it is necessary to rotate the wire when pulling out.

The bent wire end (7) does not always come into contact with the conductive plate (3) at a position facing the tip of the spring piece (4) against the pressing force of the spring piece, but does come into contact with the vertically displaced position. Or the contact pressure weakens. The portion of the wire end (7) exposed to the air without coming into contact with the conductive plate (3) gradually deteriorates in conductive performance due to oxidation or adhesion of dirt. When the wire end (7) undergoes bending stress due to maintenance or the like and undergoes shape change after such aging, the wire end (7) does not come into contact with the conductive plate (3) until now, and the surface has a conductive performance. A state where the deteriorated portion comes into contact with the conductive plate (3) occurs, which causes poor conduction.

FIG. 2 is a partial cross-sectional view 1 of a conventional screwless branch connector, showing a state in which the middle portion of the wire end (7) is bent into a shape bulging toward the conductive plate (3).
The contact position with the conductive plate (3) is not the position facing the spring piece tip (4) but the intermediate position between the two spring piece tips (4), and even if the wire end (7) is slightly deformed, the contact position Changes.

In this state, after a long time has passed, the surface of the wire terminal (7) that has not been in contact with the conductive plate (3) deteriorates in conductivity due to oxidation or dirt, and then the wiring state changes and the wire terminal (7)
3) Partial cross-sectional view of the conventional screwless branch connector. In the state of Part 2, the part that was in contact with the conductive plate (3) until now is separated and the part that was exposed to air is contacted. As a result, the contact position is moved, which is a cause of defective conduction. In the electric wiring work using the conventional screwless branch connector, linearity of the electric wire end (7) is strictly required.

[0008]

FIG. 1 shows a screwless branch connector in which a convex shape is provided as a circular groove having a guide function in a portion of a conductive plate (3) of the present invention which faces a tip (4) of a spring piece. It is an AA sectional view showing 1). A convex portion (5) is provided as a circular groove having a guide function at a position facing the spring piece tip (4) of the conductive plate (3) with the wire end (7) inserted, and the spring piece tip (4) is provided. The upper and lower positions that do not face each other are concave. Form the convex portion (5) of the conductive plate (3) at a position to hold the conductive plate (3) of the outer frame (2) integrally molded with the spring piece or the outer frame (2) separately molded with the spring piece. A convex reinforcing portion (6) is provided for reinforcement.

FIG. 8C-C is a sectional view showing a state in which the tip (4) of the spring piece and the convex portion (5) of the conductive plate (3) are in contact with the wire end (7). Contact at a position facing (4). 9D-D is a sectional view at a position deviated from the position of the tip (4) of the spring piece, and the conductive plate (3)
It is shown that the recessed part of is separated from the electric wire end (7) and does not contact.

FIG. 4 is a partial cross-sectional view of BB of the present invention. In FIG. 4, the electric wire terminal (7) having a bulging shape is inserted between the spring piece tips toward the conductive plate (3) side, and the electric wire end (7) faces the conductive plate (3) facing the spring piece tip (4). ) Is in contact with the convex portion (5) and the other part of the conductive plate (3) that does not face the spring piece tip (4) is an empty portion (9) and is not in contact. Even if the wire shape is changed from this state and the wire terminal (7) is deformed as shown in FIG. 5 Partial cross-sectional view of BB of the present invention, the wire terminal (7) is conductive as before the deformation. It is in contact with the convex portion (5) of the plate (3).

Since the screwless branch connector is reusable, when pulling out the wire end (7) against the retaining effect of the spring piece, the wire end (7) is pulled out while being rotated. Therefore, the screwless branch connector has a fixing force enough to rotate the wire end (7). Taking this rotation into consideration, the peaks of the convex portion (5) are sawtoothed in the circumferential direction of the electric wire end, and when the electric wire end (7) rotates in the circumferential direction, rust removal due to friction with the sawtooth Get the effect. In this way, the pressing force of the spring piece is stable and becomes the contact pressure between the wire end (7) and the conductive plate (3), and the contact position does not change, so that no conduction failure occurs.

Further, the electric wire (8) is inserted into the screwless branch connector by stripping the insulating coating, but the electric wire (8) is also inserted into the electric wire end insertion port to prevent the risk of short circuit. Considering the state of holding the bent electric wire end (7) including the electric wire end insertion port as an example of a screwless branch connector having two spring pieces for one electric wire end (7), the electric wire end ( Since 7) receives pressing force at three points: the spring piece on the back side, the spring piece on the entrance side, and the end of the wire terminal insertion port, depending on the bending condition, the spring pressure may be the wire terminal (7) and the conductive plate (3). Since the contact pressure is not the same as the contact pressure with the contact pressure, the contact pressure is reduced, which is a cause of conduction failure together with the deterioration of the conductive performance.

FIG. 6 Wire end and insertion port piece 1B-B is a cross-sectional view showing an exaggerated expression when a bent electric wire is inserted in a screwless branch connector. The electric wire end (7) is an electric wire end insertion port. It shows a state in which it is fixed by the piece (10) and two spring pieces, and the convex shaped part (5) of the conductive plate (3) and the wire end (7) facing the tip (4) of the spring piece on the far side. Are not in contact. This is a state in which the pressing force of the spring piece tip (4) due to the deformation of the wire end (7) is not the contact pressure between the convex portion (5) and the wire end (7).

When the shape of the wire end (7) is changed from this state to the cross section of the wire end and the insertion port piece 2B-B in FIG. 7, unlike the case of FIG. 6, the tip of the spring piece (4) on the back side is changed. ), The convex part (5) of the conductive plate (3) facing the wire end (7)
6, the convex portion (5) of the conductive plate (3) facing the inlet-side spring piece tip (4) that was in contact with FIG. 6 is not in contact with the wire end (7). Fig. 6 Fig. 7 is exaggeratedly expressed, but it is difficult to prevent residual stress due to elastic strain of the wire end (7).

In this way, the wire end insertion piece (10) is
It has the disadvantage of continuity. This wire end insertion piece (1
The contact inhibition factor of 0) was solved by making the material of the wire end insertion port piece (10) to have a large creep property.
The wire end insertion piece (10) is made of a material having a large creep property, so that it is rigid and rigid during wiring work, and the wire end (7) requires linearity and retains its shape until the work is completed. However, after the completion of construction, the creep characteristic absorbs the elastic strain remaining in the wire end (7) and slowly deforms, so that the pressing force applied to the wire end (7) is inserted into the two spring pieces and the wire end. From the three points on the mouth end to the two points on only two spring pieces, the tip of the spring piece (4)
The pressing force of becomes contact pressure to the convex portion (5) of the conductive plate (3) and becomes stable.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a screwless branch connector (1) in which a convex portion (5) is provided as a circular groove having a guide function at a portion of a conductive plate (3) of the present invention which faces a tip (4) of a spring piece. ) Is a sectional view taken along line AA. With the electric wire end (7) inserted, a convex portion (5) is provided as a circular groove at a position facing the spring end (4) of the electric wire end guide groove (11) of the conductive plate (3), and the end of the spring end is provided. The upper and lower positions that do not face (4) are concave. The convex portion (5) of the conductive plate (3) is formed at a position where the outer frame (2) integrally formed with the spring piece or the conductive plate (3) of the outer frame (2) separately formed with the spring piece is held. A convex reinforcing portion (6) is provided for reinforcement.

The height of the convex portion (5) is the amount of swelling of the wire end (7) generated between the tips of the upper and lower spring pieces (4) caused by the allowable bending of the wire end (7) and the tip of the spring piece (4).
It must be higher than the amount of bulge between the wire and the wire end insertion port, but the wire end (7) must be able to be inserted. The shape of the peak of the convex portion (5) is square, round or trapezoidal and is appropriately selected depending on the thickness of the conductive plate (3) and the pressing force of the spring piece. As another example, the convex shape portion (5) has a mountain shape in a sawtooth shape in the circumferential direction of the electric wire end, and when the electric wire end (7) rotates in the circumferential direction, an effect of removing rust due to friction with the sawtooth is obtained. obtain. On the side surface of the convex portion (5), the electric wire terminal insertion port side is made gentle so that the electric wire terminal (7) is not restricted from being inserted.

The side of the convex portion (5) opposite to the electric wire terminal insertion port has a shape which is durable and easy to process regardless of insertion of the electric wire end (7). The entrance side and the back side of the convex portion (5) of the conductive plate (3) need only have a guide function of the electric wire end (7), and therefore it is not necessary to take extra length. As a protection of the convex portion (5), a convex reinforcing portion is provided on the outer frame (2) integrally formed with the spring piece or the outer frame (2) separately formed with the spring piece so that the shape of the conductive plate (3) does not change. (6) is formed to protect the shape of the conductive plate (3), but it can be omitted if the conductive plate (3) has sufficient strength.

A part of the embodiments will be described below with reference to the drawings. FIG. 4 is a first partial cross-sectional view of the present invention taken along line BB. There is a wire terminal insertion hole in the upper part of the outer frame (2) integrally formed with the spring piece or the outer frame (2) separately formed with the spring piece, and the conductive plate (3) facing the spring piece is incorporated. In FIG. 4, the electric wire terminal (7) having a swelling shape is inserted between the spring piece tips (4) on the side of the conductive plate (3), and the electric wire end (7) is a conductive surface facing the spring piece tip (4). The other part of the conductive plate (3), which is in contact with the convex portion (5) of the plate (3) and does not face the tip of the spring piece (4), is an empty space (9) and is in contact with it. Absent.

Even if the electric wire terminal (7) is deformed as shown in FIG. 5, a partial sectional view taken along the line BB of FIG. 5 of the present invention, the electric wire terminal (7) is deformed in the same manner as before the deformation. ) Is in contact with the convex portion (5) of the conductive plate (3). In this way, the pressing force of the spring piece is stable and becomes the contact pressure between the electric wire end (7) and the conductive plate (3), and the contact position does not change, so that no conduction failure occurs.

Further, the electric wire (8) is inserted into the screwless branch connector after peeling off the insulating coating, but the electric wire (8) is also inserted into the electric wire terminal insertion port piece (10) up to the covering portion to prevent the risk of short circuit. Considering the state of holding the bent electric wire end (7) including the electric wire terminal insertion port as an example of a screwless branch connector having two spring pieces for one electric wire end (7), Since (7) receives pressing force at three points: the spring piece on the back side, the spring piece on the entrance side, and the end of the wire terminal insertion opening, depending on the bending condition, the spring pressure is applied to the wire terminal (7) and the conductive plate (3). ), The contact pressure is reduced, which, in combination with the deterioration of the conductive performance, causes poor conduction.

FIG. 6 Wire end and insertion port piece 1B-B is a cross-sectional view showing an exaggerated expression when a bent electric wire is inserted into a screwless branch connector. The electric wire end (7) is an electric wire end insertion port. It shows a state in which the piece (10) and the two spring pieces are fixed at three points, and the convex shaped part (5) of the conductive plate (3) and the wire end ( 7) is not in contact. This is a state in which the pressing force of the spring piece tip (4) is not the contact pressure with the conductive plate (3) due to the deformation of the wire end (7).

When the shape of the electric wire end (7) changes from this state to the cross section of the electric wire end and the insertion port piece 2B-B in FIG. 7, unlike the case of FIG. ), The convex part (5) of the conductive plate (3) facing the wire end (7)
6, the convex portion (5) of the conductive plate (3) facing the inlet-side spring piece tip (4) that was in contact with FIG. 6 is not in contact with the wire end (7).

FIG. 6 FIG. 7 is exaggeratedly expressed, but it is difficult to prevent residual stress due to elastic strain of the wire end (7). Thus, the wire end insertion piece (10) has a disadvantage in terms of continuity. The cause of contact inhibition of the wire end insertion port piece (10) was solved by making the material of the wire end insertion port piece (10) large in creep property.

The wire end insertion port piece (10) is made of a material having a large creep characteristic, so that it is rigid and rigid during wiring work, and the wire end (7) requires linearity until the work is completed. It retains its shape, but after completion of construction, its creep characteristics absorb the elastic strain remaining in the wire end (7) and slowly deform it, so that the pressing force applied to the wire end (7) becomes two spring pieces. The pressing force at the tip of the spring piece (4) is changed from the three points at the end of the electric wire terminal to the two points of only the two spring pieces so that the convex portion (5) of the conductive plate (3)
It becomes the contact pressure to and becomes stable. The present invention can improve the reliability of the function without impairing the conventional manufacturing cost.

[0026]

As described above, the screwless branch connector for electric wiring according to the present invention has the problem of contact failure due to bending or secular change of the wire end, which has been a problem of the conventional screwless branch connector, and the conductive plate. To fix the contact position in (3),
The elastic deformation of the electric wire end (7) is absorbed by the creep deformation of the electric wire end insertion port piece (10) and the pressing force of the spring piece is maintained as a stable contact pressure, which is prevented and a highly reliable electric wiring can be provided. .

[Brief description of drawings]

FIG. 1 is a sectional view taken along line AA.

FIG. 2 Partial cross-sectional view of a conventional screwless branch connector part 1
Is.

FIG. 3 Partial cross-sectional view of a conventional branch connector without screws Part 2
Is.

FIG. 4 is a first partial cross-sectional view taken along the line BB.

FIG. 5 is a second partial sectional view taken along line BB.

FIG. 6 is a sectional view of the wire end and the insertion port piece 1B-B.

FIG. 7 is a 2B-B sectional view of the wire end and the insertion port piece thereof.

FIG. 8 is a sectional view taken along line CC.

FIG. 9 is a sectional view taken along line D-D.

[Explanation of symbols]

1 Screwless branch connector 2 outer frame 3 conductive plate 4 Tip of spring piece 5 Convex part 6 convex reinforcement 7 Electric wire terminal 8 electric wires 9 empty space 10 Wire end insertion piece 11 Electric wire terminal guide groove

Claims (5)

[Claims] 1. An electric wire end guide groove (1) of a conductive plate (3).
A screwless branch connector for electric wiring, characterized in that the position facing the tip (4) of the spring piece of 1) is a convex portion (5) with the guide groove left. 2. A screwless branch connector for electric wiring, characterized in that the wire end insertion piece (10) is formed of a material having a moderately large creep characteristic. 3. A wire end guide groove (1) of a conductive plate (3).
The position facing the tip (4) of the spring piece (1) is a convex portion (5) with the guide groove left, and the wire end insertion piece (10) is formed of a material having a reasonably large creep property. Screwless branch connector for electrical wiring. 4. The electrical wiring according to claim 1, 2, or 3, wherein the convex portion (5) has a mountain shape in a sawtooth shape in a circumferential direction of the electric wire. Branch connector without screws. 5. A convex reinforcing portion (6) is provided to reinforce the convex portion (5) of the conductive plate (3) at a position where the conductive plate (3) of the outer frame (2) is held. The screwless branch connector for electrical wiring according to claim 1, claim 3, or claim 4.