JPH07312253A - Power cord - Google Patents

Abstract

PURPOSE:To prevent the disconnection and detachment of a cord core wire by providing a first covering body having a hardness equal to or higher than a blade body holder resin, and a second covering body for protecting and covering the cord side. CONSTITUTION:A first covering body 31 having a hardness equal to or higher than an edge body holder 25 is filled in the space part 30 of the holder 25 and the through hole 29a of an insulating wall 29, and a conductor part 24b and a caulking piece 24c are fixed to the holder 25. A plug edge 24 is thus fixed to the holder 25 to prevent the breakage of the conductor part 24a, and the detachment of a core wire 23a from the caulking piece 24c can be prevented. Further, the covering body 31 is integrally covered with a second covering body 32. The covering body 32 covers the most outside of a plug part 22a, and also forms a protector part 22b. Since the edge 24 is fixed to the holder 25 by the covering body 31, the covering body 32 can be formed of a soft resin. Thus, even when a bending stress is added to the cord 23, it is bent from the boundary with the part 22b, and the disconnection of the core wire 23a in the boundary can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power cord used in, for example, a vacuum cleaner.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 9A and 9B, a plug 1 of a power cord used in, for example, an electric vacuum cleaner is formed with a pair of insertion holes 2 and a continuation of the insertion holes 2. Blade support portion 3 for supporting the cut blade 1a, and a blade holder 5 having shape retention formed of a difficult resin having a space 4 facing the blade support 3 and a resin filling portion. And a pair of blades 1a in which a core wire 8 of a cord 7 is fixed to a core wire fixing portion 6 provided at one end of the blade body 1a are inserted into the insertion hole 2 and stored, and in this stored state, FIG. ), The blade holder 5 is covered with a covering body 9 made of a resin such as vinyl chloride having a hardness lower than that of the resin forming the blade holder 5. At the time of this coating, the space 4 is filled with the coating 9, so that the blade 1a is fixed. At the same time,
Since the cover 9 is soft, it has a function of a protector for preventing disconnection of the core wire 8 caused by repeated bending during use of the cord 7, so as to protect the core 7 by covering a predetermined length from the end of the cord 7. 9a is formed.

[0003]

However, the above-mentioned coating 9
On the one hand, it is necessary to provide the protector function on the one hand, so that the hardness for achieving this function, that is, the bendable low hardness is required, and on the other hand, the function of fixing the blade body 1a in the blade body holder 5 is also required. Since they are required, high hardness is required in order to achieve this fixing function, and thus, contradictory hardness is required.

Therefore, since the covering body 9 of the plug 1 in the conventional power cord has a hardness that has both of the above-mentioned functions, it is not sufficient particularly in the latter function of fixing the blade body 1a in the blade holder 5. As a result, there is a problem that the blade body 1a is broken in the blade body holder 5. The breakage of the blade body in the blade body holder 5 is caused by the following causes. That is, the plug 1 has its blade body 1a inserted into an outlet not shown during use, and especially when the cord is long, such as in a vacuum cleaner, it is inserted into the outlet each time the cord is pulled around. A bending stress is applied to the blade body 1a that has been squeezed, and at that time, the hardness of the covering body 9 that is filled in the space portion 4 of the blade body holder 5 is insufficient, so that the blade body 1a moves, especially the core wire fixing portion 6 Repeated bending stress is applied to the thin conductor portion 1b provided in the vicinity of, resulting in elastic fatigue, and the conductor portion 1b is broken.

Further, since the covering body 9 has a hardness that allows the blade body 1a to have a fixing function, the hardness is too hard to be sufficiently flexible in terms of the protector function, and therefore the protector portion 9a is not necessarily sufficient. There is a problem that the cord sharply bends at the boundary between the cord 7 and the cord 7, and the core wire 8 in this portion is broken.

Furthermore, the core wire 8 to the core wire fixing portion 6
As a method of fixing the blade portion, a part of the blade portion is thinned to form a caulking portion integrally with the blade body, and the core wire 8 is caulked and fixed to the caulking portion, or one end of the blade body without the caulking portion. A method of fixing the core wire directly to the core wire fixing portion 6 by spot welding is used, but in any fixing method, the core wire 8 fixed to the core wire fixing portion 6 is removed from the core wire fixing portion 6 by the stress applied to the blade during the use. There is a problem that it may come off due to a disconnection or the like, resulting in defective conduction.

[0007]

In order to solve the above problems, the present invention forms a pair of blade body insertion holes and blade body support portions in the vicinity of the side walls of the blade body insertion holes, and at the same time, the blade body support portion. A blade holder having a shape-retaining property made of a difficult resin in which a resin-filled portion is formed so as to face the core wire, and a core wire drawn from the end of the cord is attached to the core wire fixing portion provided at one end and the other end side is attached. A pair of blades that are inserted into the blade insertion hole and housed in the blade holder, and cover the blade holder that includes at least the resin filling portion that is made of flame-retardant resin and that the blade holder A first coating having a hardness substantially equal to or higher than the hardness of the resin forming the resin, and at least a part of the first coating which is made of a soft resin and covers the end of the cord. Form a protector part to protect the part And a second cover, a power cord having a plug and a blade support part is formed in the vicinity of a side wall of the blade insert hole and the blade support part. A blade holder having a shape-retaining property made of a difficult resin with a resin-filled portion facing each other, and a core wire drawn from the end portion of the cord attached to the core wire fixing portion provided at one end and the other end side A pair of blades inserted into the blade insertion hole and housed in the blade holder, and made of a resin that is flame-retardant and has a hardness equal to or higher than the hardness of the resin forming the blade holder. A first coating body that covers at least the blade holder including at least the resin filling portion and the core wire fixing portion, and at least a part of the first coating body on the cord side, which is made of a soft resin, and the cord. Protects the edges of It is obtained by a power cord arrangement with a plug and a second cover member forming the terpolymer section.

[0008]

With the above-described structure, the blade holder is formed even when the blade of the plug inserted into the outlet is subjected to bending stress due to the power cord being laid while the electric device such as the vacuum cleaner is being used. Since the blade body is securely fixed in the blade body holder by the first coating body made of resin having a hardness equal to or higher than that of the resin to be used, the blade body is not broken, and the first coating is used. Since it has a role of fixing the blade to the body, the second part that covers the cord
Since the hardness of the cover can be made low enough to have a protector function, the second cover follows the cord when the cord is laid, and the cord is integrated with the protector portion formed by the second cover. Since it bends to the side, the cord does not bend at the border with the protector,
It is possible to prevent breakage of the core wire.

Further, by covering the blade holder by including the core fixing portion with the first cover, the core fixing portion is securely fixed in the blade holder, so that the bending stress caused by the running of the cord during use causes The core wire of the core wire fixing portion does not come off due to a disconnection or the like, so that it is possible to prevent the occurrence of defective conduction.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a plug of a power cord according to an embodiment of the present invention. In the figure, a power cord 21 is composed of a plug 22 and a cord 23, and the plug 22 is a pair of blades. It has a plug portion 22a having a plug blade 24 and a protector portion 22b formed integrally with the plug portion 22a.

The plug 22 has a plug 22a.
Is provided with a non-slip concave portion 22c and a rib 22d for preventing the plug 22 from slipping from a finger when it is inserted into or pulled out from an outlet not shown. The protector portion 22b is provided with a plurality of cutout recesses 22e for enhancing flexibility.

Next, FIG. 2 is a perspective view showing a blade holder 25 for accommodating the pair of plug blades 24, and FIG. 3 is a sectional view of the blade holder 24 taken along line AA in FIG. There is a diagram. The blade holder 25 is made of a difficult resin such as unsaturated polyester and melamine, and has shape retention after molding. As shown in the figure, the blade holder 25 has a pair of blade insertion holes 26 into which the plug blades 24 are inserted. Further, the blade body holder 25 is formed with a support portion 27 as a blade body support portion for supporting the plug blade 24 continuously to the blade body insertion hole 26. Further, inside the blade insertion hole 26, there is provided an engagement protrusion 28 which engages with an engagement hole 24d (see FIG. 4) formed in the plug blade 24 to position the plug blade.

A rectangular cylindrical insulating wall 29 having a through hole 29a is provided at the center of the blade holder 25, and the insulating wall 29 is formed at one end of a plug blade 24 described later. When the blade body holder 25 is covered with a first coating body 31 made of a resin described later while ensuring an insulation distance between the crimped piece 24c and the core wire 23a of the cord 23 fixed to the crimped piece 24c, the blade body holder 25 And the first
It plays the role of surely integrating with the cover 31.

A space portion 30 is formed between the support portion 27 and the insulating wall 29 as a resin filling portion filled with the first cover 31.

FIG. 4 is a perspective view showing the entire plug blade 24. The plug blade 24 is integrally formed with the blade portion 24a and the blade portion 24a so as to be thinner and narrower than the blade portion 24a. And the narrow conductor portion 24b formed by
It is composed of a pair of caulking pieces 24c as core wire fixing portions formed at the tip of b.

FIG. 5 is a view showing a state in which the core wire 23a of the cord 23 is fixed to the caulking piece 24c on the plug blade 24. This fixation is performed after the core wire 23a is positioned between the caulking pieces 24c. The piece 23a is bent inward and fixed by caulking.

Next, FIG. 6 shows the power cord 2 of the above embodiment.
FIG. 3 is a cross-sectional view showing the configuration of No. 1 in which the plug blade 24 is inserted into the insertion hole 26 of the blade body holder 25 to be housed therein, and the blade body holder 25 in this state is integrally covered with the first cover 31. The first cover 31 is JIS K 7201.
It is a difficult resin such as vinyl chloride having an increased oxygen index, which is defined by the above, and has a hardness equal to or higher than the hardness of the blade holder 25 after molding. The first cover 31 is the blade holder 25.
When it is covered, the space 30 of the blade holder 25 and the through hole 29a of the insulating wall 29 are also filled. Then, the space portion 30 is filled with the first cover 31, so that the conductor portion 24b of the plug blade 24 and the caulking piece 24 are formed.
Since c is securely fixed in the blade holder 25, it does not move even if external stress is applied to the plug blade 24, and is securely fixed in the blade holder 25, so that the conductor portion 24b is narrow.
Will not break.

The first cover 31 is the caulking piece 24.
Since it is provided so as to cover the end portions of c and the cord 23 as well, even if external stress is applied to the plug blade 24 and the cord 23, there is no risk that the core wire 23a will separate from the caulking piece 24c and a conduction failure will occur. Absent.

The first cover 31 is integrally covered with the second cover 32. The second cover 32 covers the outermost side of the plug portion 22a and forms the protector portion 22b. Then, this second cover 3
2, the plug blade 24 is fixed to the blade holder 25 by the first cover 31, so that the plug blade 24 is made of a soft resin having a lower hardness than the conventional one, that is, a low hardness required for the protector function, such as soft vinyl chloride. be able to. Therefore, even if a bending stress is applied to the cord 23, the cord 23 is not bent sharply from the boundary with the protector portion 22b, and there is no fear that the core wire 23a is broken at the boundary.

As described above, according to the above-described embodiment, the first cover 31 has the function of securely fixing the plug blade 24 to the blade holder 25, and the second cover 32 has the cord 23.
Since the hardness is low and soft so that it can follow the bending of the plug, and the protector function is provided, the fixing function of the first cover body 31 can prevent the plug blade body 24 from being broken.
The protector function of the cover 32 can prevent the core wire 23a of the cord 23 from being broken.

According to the inventor's confirmation, vinyl chloride having a hardness of 96 degrees and an oxygen index of 32 is used as the first coating 31, and a hardness of 85 degrees and an oxygen index of 2 are used as the second coating 32.
Good results were obtained with 7.5 vinyl chloride.

Next, how to make the power cord 21 of this embodiment will be described with reference to FIGS. 6 and 7A and 7B. First, after inserting the pair of plug blades 24 in which the core wire 23a of the cord 23 is fixed to the caulking piece 24c into the blade body insertion hole 26 and storing them in the blade body holder 25 (FIG. 7 (A)),
The blade holder 25 is set in a molding die (not shown), the resin forming the first cover 31 is injected, and the space portion 30, the conductor portion 24b, the caulking piece 24c portion and a part of the end portion of the cord 23 are injected. The entire blade holder 25 including the blade is covered (FIG. 7 (B)).

Next, the one covered with the first cover 31 is set in a mold not shown, and the second cover 32 is placed.
The assembly is completed by injecting the resin forming the above and covering the first cover 31 and the end portion of the cord 23 including a predetermined length (FIG. 6).

In FIG. 8, the description thereof is omitted, but Y- of FIG.
Sections taken along the line Y (that is, ZZ in FIG. 6) and shown with the same reference numerals attached to the same portions as those described above.

In the above embodiment, the entire blade body holder 25 including the space portion 30, the crimping pieces 24c, that is, the core wire fixing portion and a part of the end portion of the cord 23 is covered with the first covering body 31, but the entire body is not necessarily covered. It is not necessary to cover, and in order to prevent only the breakage of the narrow conductor portion 24b of the plug blade 24, it is sufficient to cover up to the space portion 30.
When it is desired to prevent the crimping piece 24c and the core wire 23a from coming off at the same time, the caulking piece 24c may be covered. In addition, when a part of the end of the cord 23 is covered, disconnection of the core wire 23a at the end of the cord 23 can be prevented.

Although the second coating 32 covers the entire first coating 31, the entire coating is not necessarily required.
From the viewpoint of preventing disconnection of the core wire 23a of the cord 23, at least the predetermined length of the end portion of the cord 23 and the cord 23
It suffices to cover a part of the first cover 31 on the end side of the. However, since the plug 22 is covered with the soft second covering body 32 by covering the entire first covering body 31, there is an advantage that the furniture is not damaged even if the plug 22 hits furniture, for example. .

[0028]

As described above, according to the first aspect of the present invention, the plug blade is housed in the blade body holder and both are integrally formed to have the same hardness as or higher than that of the blade body holder.
Since it is covered with the cover, the plug blade can be securely fixed to the blade holder, the plug blade is not damaged even if bending stress is applied to the plug, and the second cover that covers the first cover is the protector. Since the hardness can be made sufficiently low for the function, it is possible to prevent disconnection of the core wire at the connecting portion between the cord and the plug. Further, according to the invention of claim 2, since the core wire fixing portion is reliably fixed in the blade body holder by covering the blade body holder including the core wire fixing portion with the first cover, the cord in use It is possible to obtain an effect that the core wire of the core wire fixing portion is not detached due to a disconnection or the like due to the bending stress due to the wiring of the wire, and the occurrence of the defective conduction can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view of a power cord according to an embodiment of the present invention.

FIG. 2 is a perspective view of a blade holder according to the embodiment.

FIG. 3 is a sectional view of the blade holder according to the embodiment (FIG. 2).
AA sectional view).

FIG. 4 is a perspective view of a plug blade body according to the embodiment.

FIG. 5 is a perspective view showing a state in which the core wire of the cord is fixed to the plug blade in the embodiment.

FIG. 6 is a cross-sectional view showing the configuration of a power cord plug in the embodiment.

FIG. 7 is an explanatory view showing the procedure for assembling the power cord in the embodiment.

FIG. 8 is a cross-sectional view of the plug blade body according to the embodiment.

FIG. 9 is a cross-sectional view showing the configuration of a conventional power cord plug.

[Explanation of symbols]

 21 power cord 22 plug part 22b protector part 23 cord 23a core wire 24c crimping piece (core wire fixing part) 24 plug blade body 25 blade body holder 26 blade body insertion hole 27 blade support wall 30 resin filling portion 31 first coating body 32 21st cover

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masaki Nagano 5-5-48 Hongo, Kashiwara-shi, Osaka Within Fujidensen Kogyo Co., Ltd. (72) Inventor Shinichi Tsujino 5-54 Hongo, Kashiwara-shi, Osaka Fuji Electric Wire Co., Ltd.

Claims (2)

[Claims] 1. A pair of blade body insertion holes and a blade body support portion formed in the vicinity of the side wall of the blade body insertion hole, and a resin-filled portion facing the blade body support portion. A shape holder blade holder and a core wire drawn from the end of the cord are attached to the core wire fixing part provided at one end, and the other end side is inserted into the blade insertion hole and stored in the blade holder. And a pair of blades that are made of a flame-retardant resin and cover the blade holder including at least the resin-filled portion and have a hardness that is substantially the same as or higher than the hardness of the resin that forms the blade holder. A plug including a first cover and a second cover made of a soft resin, which covers at least a part of the first cover on the cord side and forms a protector portion for protecting an end of the cord. Power cord with 2. A pair of blade body insertion holes and a blade resin support portion formed near the side wall of the blade body insertion hole, and a resin-filled portion facing the blade body support portion. A blade holder with shape retention and a core wire drawn from the end of the cord are attached to the core wire fixing part provided at one end, and the other end is inserted into the blade insertion hole and stored in the blade holder. The blade holder including at least the resin filling portion and the core wire fixing portion, which is made of a flame-retardant resin having a hardness equal to or higher than the hardness of the resin forming the blade holder. And a second coating body made of a soft resin for coating at least a part of the first coating body on the cord side and forming a protector portion for protecting an end portion of the cord. With a plug consisting of Code.