JPS6236349B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cord holding structure having a tension removing structure that prevents tension applied to a power cord from acting on the connection between the power cord and a terminal, for example in a power plug. It is.

1 to 3 show conventional examples of power plugs. In Figure 1, a pair of clamping plates 25, 25, one of which is fixed to the plug body 1, is provided on the back of the plug body 1, and a cord 26 passed between the clamping plates 25, 25 is tightened with a screw 27. It is fixed. This device has a large number of parts, is cumbersome to operate, is expensive, and is dangerous because the screws and clamping plates are exposed and have a high possibility of breakage. In the one shown in FIG. 2, both of the clamping plates 25, 25 are fitted into the fitting grooves 28 provided inside the body 11 and the cover 12 which is joined to the body 11. Even with products, there are many parts and operation is troublesome.
Both clamping plates occupy a large space, and in this case, both clamping plates are made of metal, which is dangerous because there is a risk of a short circuit if the insulation of the cord's insulation deteriorates. The plug shown in FIG. 3 has a protrusion 30 integrally formed in the body 11 and cover 12 of the plug during molding, and the protrusion 30 is tightened by the tightening force of an assembly screw 29 to assemble the body 11 and cover 12.
0 is pressed against the cord 26 to fix the cord 26. In this case, since the distance between the protrusion on the body and the protrusion on the cover is constant, it cannot be applied if the outer diameter of the cord differs, and since a reaction force is always applied to the assembly screw to fix the cord, the assembly screw cannot be used. This causes the cord to become loose, which ultimately weakens the tension removal force of the cord. This is the same not only in this conventional example but also in the two conventional examples mentioned above because a reaction force is applied to the screw, and the tension removal force is uniform because it changes depending on the tightening force of the screw and the tightening force of the assembly screw. It has the disadvantage of lack of character.

The present invention has been provided in view of such conventional examples, and its purpose is to be able to use cords of various outside diameters without any treatment, and to reduce the cord tension by the elastic force of the elastic holding piece. Since the removal force is almost determined, the cord is securely held without being affected by the tightening force of assembly screws and screws, etc. In addition, the required space is small, and a pair of elastic Another object of the present invention is to provide a cord holding structure in which the cord can be easily inserted between the opposing locking protrusions of the holding piece, and another object is to provide a cord holding structure that is highly adaptable to the diameter of the cord and protects the covering of the cord. Provides a code holding structure,
Another objective is to create a cord holding structure that allows smooth assembly work for assembling the elastic holding piece to the body, inserting the cord, and attaching the cover to the member consisting of the body and cover. It is on offer.

The present invention will be described in detail below based on an embodiment of the illustrated power plug.The plug body 1 includes a body 11 and a cover 12.
It has a cord insertion opening 2 formed by 3. The body 11 and the cover 12 each have locking holes 4, 4 on both sides of the cord introduction groove 13, and the area between the locking hole 4 and the cord introduction groove 13 is
They are connected by notches 5, 5 which are inclined relative to the axis of 3. Here, on the one end opening side of the cord introduction groove 13, one side wall surface of the notch 5 is configured as a support rib 14, and the wall surface of the cord introduction groove 13 that is at the back of the cord introduction groove 13 and continuous with the notch 5 at an obtuse angle is an arcuate wall surface 15. It is said that On the other hand, 6 is an elastic holding piece having elasticity such as thermoplastic synthetic resin.
One end is provided with a columnar portion 7, and the other end is provided with a plurality of locking protrusions 8 on one side. The columnar part 7 is provided with an even smaller rib 9, and when the columnar part 7 is inserted into the locking hole 4 whose shape is slightly larger than the diameter of the columnar part 7, the protruding rib 9 touches the inner peripheral surface of the locking hole 4. The elastic holding piece 9 is press-fitted and locked. This elastic holding piece 6 is attached to the cord introduction groove 13 on the cover 12 side.
It is press-fitted into the locking hole 4 of the body 11, which is formed deeper than the locking hole 4 and notch 5, respectively, and the other end of the locking protrusion 8 protrudes into the cord introduction groove 13 through the notch 5. The locking protrusions 8 of both elastic holding pieces 6, 6 are made to face each other. And the plug blade 19
The cord 26 is inserted between the pair of elastic holding pieces 6 and connected to the terminal portion 18 in the body 11 equipped with the above. A cord 26 is inserted between both elastic holding pieces 6, 6.
The work of inserting the locking protrusion 8 is as shown in Figure 6.
Since the side edges of the insert are notched diagonally and chamfered to form the insertion guide portion 17, the insertion can be carried out smoothly. By providing the insertion guide portions 17 at both ends of the locking protrusion 8, the left and right elastic holding pieces 6 can be used in common. In this way, code 26 is connected to body 1.
1, the cover 12 is joined to the body 11, and both are tightened with assembly screws 29. At this time, the cord insertion groove 13 on the body 11 side, the locking hole 4
By making the notch 5 larger than that of the cover 12 so that the elastic holding piece 6 is more than half buried in the body 11, it is possible to prevent the elastic holding pieces 6 from opening when the cord 26 is inserted. Although it is suppressed, it still opens up a little. For this reason, the width at the back of the cord introduction groove 13 on the cover 12 side is made slightly larger than that on the body 11 side, and the openings of the locking hole 4 and notch 5 on the joint surface of the cover 12 with the body 11 are sufficiently chamfered. The guide portion 16 is provided with a wider diameter or width as shown in FIG. A cord positioned in the cord insertion opening 2 formed by the cord introduction grooves 13 and 13 by joining the body 11 and the cover 12 so as to fit in the locking hole 4, the notch 5, and the cord introduction groove 13. 26 is a pair of elastic holding pieces 6, 6
The cord 26 is clamped from both sides by opposing locking protrusions 8, 8 in the cord insertion opening 2, and as shown in FIGS. It is held by the elasticity of the elastic holding piece 6 which bends as it bends. Especially for the large-diameter cord 26, the arc-shaped wall surface 1 facing the cord insertion opening 2
5 and 15 support the elastic holding pieces 6 and 6 from behind, respectively, and securely hold the locking protrusion 8 against the cord 26 without weakening the pressing force thereof. In addition, in this case, even if a tension T acts on the plug body 1 in the direction of pulling the cord 26, the locking protrusion 8 of the elastic holding piece 6 is pressed against the cord 26 in accordance with this tension, as shown in FIG. 8a. Since the force will increase, it will not loosen, and in addition, the code 26
The holding force is determined by the elastic holding piece 6 and the locking hole 4 of the body 11.
The elastic force of the elastic holding piece 6 is determined mostly by the elastic force of the elastic holding piece 6, although it is slightly influenced by the degree of freedom with the notch 5 and the curvature of the arcuate wall surface 15. Since the one-end columnar portion 7 is press-fitted and locked into the locking hole 4, it does not affect or conversely affect the joint strength between the body 11 and the cover 12. That is, the pressing force F of the locking protrusion 8 due to the elasticity of the elastic holding piece 6 against the cord 26 acts in a direction perpendicular to the joint strength G of the assembly screw 29 between the body 11 and the cover 12, so that the holding force of the cord 26 is The reaction force is not applied to the assembly screw 29, and the assembly screw 29
Therefore, even if the assembly screw 29 becomes loose, the holding force of the cord 26 by the elastic holding piece 6 will not change. Furthermore, since the elastic holding piece 6 is held by the body 11 on one half of the columnar part 7 and the remaining half on the cover 12, the cord 2
The elastic holding piece 6 does not undergo any deformation that would reduce the holding force of the elastic holding piece 6, and exhibits a stable and reliable holding force, that is, a tension removing force, over a long period of time. The one shown in FIG. 9 shows another example of the elastic holding piece 8, in which the locking protrusion 8 is not linear but arc-shaped around the axis of the cord insertion hole 2. For this reason, the ability to adapt to changes in the diameter of the cord 26 is further increased, and the number of parts in contact with the cord 26 is increased, increasing the holding force.Furthermore, since the pressure contact force is not concentrated on a part of the cord 26, the covering of the cord 26 is improved. will also be protected.

As described above, the present invention has a small number of parts and is easy to install in a small space by simply press-fitting the elastic holding piece, and can be applied to a wide range of cord diameters. Since it is flexible in the direction perpendicular to the joining direction, there is no correlation between the joining strength between the body and the cover and the cord retention by both elastic retaining pieces, and they do not affect each other. It is possible to securely hold the cord with a uniform holding force for the cord of each diameter, and when both elastic holding pieces are made to be flexible in the direction perpendicular to the joining direction between the body and the cover, When joining the body and cover, both elastic holding pieces cannot be brought into contact with the cord, and the cord must be fitted between both elastic holding pieces before joining the body and cover. A chamfered cord insertion guide section is provided on the side end surface of the locking protrusion that locks onto the cord of the elastic holding piece, so the cord can be inserted smoothly between both elastic holding pieces. In addition to the above points, in the combined invention, the presence of the arcuate wall surface further increases the ability to adapt to changes in the diameter of the cord, and also increases the cord holding force, allowing for more reliable tension removal. It can be done.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional example, Fig. 2 is an exploded perspective view of another conventional example, Fig. 3 is an exploded perspective view of yet another embodiment, and Fig. 4a is a body of an embodiment of the present invention. Figure 5a is a front view of the body side, Figure b is a sectional view of the same as above, Figure c is a side view of the same as above, Figure 6 is a perspective view of the same as above. A perspective view of the elastic holding piece, FIGS. 7a and 7b are front views of the body side when the cord is inserted, FIGS. It is a perspective view of another elastic holding piece, and 2 is a cord insertion opening;
4 is a locking hole, 5 is a notch, 6 is an elastic holding piece, 7 is a columnar portion, 8 is a locking projection, 11 is a body, 12 is a cover, 13 is a cord introduction groove, and 15 is an arcuate wall surface.

Claims (1)

[Claims] 1. One end of each is press-fitted to both sides of a cord insertion hole formed in a body consisting of a body and a cover joined to the body, and each other end projects into the cord insertion hole. A pair of elastic holding pieces are provided, and both elastic holding pieces are inclined relative to the axial direction of the cord insertion opening, and the elastic holding pieces are respectively oriented in a direction in contact with the inner wall surface of the cord insertion opening, and are connected to the body and the cover. It is bendable in a direction perpendicular to the direction, and a locking protrusion is formed on the opposing surface of the other end of both elastic holding pieces, and a chamfer is formed on the side end surface of the locking protrusion located on the side edge of the elastic holding piece. A cord holding structure with a cord insertion guide section. 2. A cord introduction groove is provided in the body and a cover to be joined to the body to form a cord insertion hole when the two are joined together, and a locking hole is provided on both sides of each cord introduction groove, so that the cord can be inserted into each locking hole. The cord is connected to the groove by a notch that is inclined with respect to the axial direction of the cord introduction groove,
It has a columnar part on one end and a locking protrusion on one side of the other end, and a cord insertion guide part is provided by chamfering the side end surface of the locking protrusion located on the side edge of the elastic holding piece. The columnar parts of the pair of elastic holding pieces are press-fitted into the locking holes of the body and cover, and the other ends of both elastic holding pieces are projected into the cord insertion hole through the notch, and each locking protrusion is inserted into the cord insertion hole. The wall surface of the cord insertion opening connected to the notch at an obtuse angle is an arcuate wall surface, and both elastic holding pieces are respectively bendable along the arcuate wall surface in a direction orthogonal to the joining direction of the body and the cover. Features a cord retention structure. 3. The cord holding structure according to claim 2, wherein the locking protrusion of each elastic holding piece is formed in an arc shape centered on the axis of the cord insertion opening. 4 Make the cord introduction groove, locking hole, and notch on the body side deeper than the cord introduction groove, locking hole, and notch on the cover side, and open the locking hole and notch on the cover side at the joint surface of the cover with the body. Claim 2 is characterized in that a guide portion for inserting the elastic holding piece is provided in the part, and the width of the cord introduction groove on the cover side is larger than the width of the cord introduction groove on the body side. code holding structure.