JP3377327B2 - Molded plug - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a molded plug.

[0002]

2. Description of the Related Art Generally, a molded plug is composed of a plug blade to which a cord is connected and a plug body that integrally surrounds the poles of the plug blade while insulating them. It is made of a material, for example, a molding resin such as soft vinyl chloride.

[0003]

By the way, in such a molded plug, since the plug surface (blade surface) is formed into a flat surface, a tracking phenomenon may occur. In other words, the tracking phenomenon means that if you insert the plug into the outlet with a gap between the plug surface and leave it for a long period of time, dust or cotton dust will accumulate between the plug and the outlet. When water droplets or moisture intervene, a small current flows through the plug surface between the blades that are originally insulated. Then, a small arc flashover is repeatedly generated during the repeated application of such a slight current, and the plasticizer contained in the resin is carbonized by the heat generated at this time, and finally this carbonization is carried out. There was a problem that the blades were short-circuited through the part.

Further, if the blade receiving metal fitting of the outlet is deformed for some reason and the force of holding the plug blade of the molding plug is weakened, the contact resistance between the blade and the blade receiving metal fitting becomes large,
When the current load is large, the surrounding temperature may rise. As a result, there is also a problem that the plug main body formed of the flexible insulating material is softened by the abnormal temperature rise, the blades come close to each other, and the contact resistance is further increased.

The present invention has been made in view of the above problems, and a molded plug capable of preventing the occurrence of the tracking phenomenon for a long period of time, and further, preventing the occurrence of the tracking phenomenon for a long period of time. Provided is a molded plug capable of maintaining a constant blade blade interval even when the temperature rises abnormally.

[0006]

According to a first aspect of the present invention, there is provided a molded plug comprising a pair of plug blades to which a cord is connected and a plug body surrounding the pair of blades and molded with a flexible insulating material. It is characterized in that a concave portion is formed on the plug surface of the main body while leaving only the root periphery of each blade in an island shape.

According to a third aspect of the present invention, there is provided a molded plug in which a pair of plug blades to which a cord is connected, a pair of plug blades are arranged, and a plug base molded of a heat resistant insulating material is integrated with the plug base. It is characterized by comprising a plug body molded from a flexible insulating material, and forming a recess on the plug surface of the plug base, leaving only the root periphery of each blade in an island shape.

[0008]

According to the molded plug of the first aspect, the creeping distance between the pair of blades is formed by forming the concave portion on the plug surface of the plug body leaving only the root periphery of each blade as an island shape. It is possible to increase the length of the plug, and when the plug is inserted into the outlet, a constant space can be formed between the surface of the outlet and the outer peripheral edge of the plug surface.

As a result, even if moisture or the like is present between the surface of the outlet and the surface of the plug, the blades are not short-circuited and the occurrence of the tracking phenomenon can be prevented for a long period of time.

Further, according to the molded plug of the third aspect, the blade is disposed, and only the root periphery of each blade is island-shaped on the plug surface of the plug base molded with the heat resistant insulating material. Since the recess is left behind, the creepage distance between the pair of blades can be increased, and when it is inserted into the outlet, it remains constant with the surface of the outlet except for the outer peripheral edge of the plug surface. A space can be formed.

As a result, even if moisture or the like intervenes with the surface of the outlet, the plug blades are not short-circuited, the occurrence of the tracking phenomenon can be prevented for a long period of time, and the blade receiver of the outlet can be prevented. Even when the abnormal temperature rises due to poor contact with the metal fitting, the interval between the blades can be maintained.

[0012]

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

1 to 3 show a molded plug 1 of the present invention.
The first embodiment of the present invention is shown. The molding plug 1 is composed of a plug blade 3 to which a cord 2 is connected and a plug body 4 surrounding the plug blade 3 and molded with a flexible insulating material. On the plug surface 41 of the plug body 4, a recess 41x is formed, leaving the root edge 411 of the blade 3 in an island shape.

As a result, the creepage distance between the blades 3, 3 can be increased, and as shown in FIG. 3, the concave portion 10x is formed around the insertion port 10a of the outlet 10. Thus, a constant space can be formed between the plug surface 41 and the surface of the outlet 10 except for the outer peripheral edge of the plug surface 41 that is in close contact with the surface of the outlet 10.

Therefore, the molded plug 1 is connected to the outlet 1
Even if a water droplet penetrates into the surface of the outlet 10 in a state of being inserted into 0, the water droplet wraps around along the outer peripheral edge of the plug surface 41 that is in close contact with the surface of the outlet 10 due to the capillary phenomenon, so It is possible to prevent a short circuit between the blades 3 and 3 without falling into the recess 41x. Even if water drops fall into the recess 41x, the root edge 411 of the blade 3 is isolated in an island shape and a constant space is formed between the blade 3 and the surface of the outlet 10. , 3 is not short-circuited unless the concave portion 41x is infiltrated. Therefore, the occurrence of the tracking phenomenon can be prevented for a long period of time.

Next, a second embodiment of the molding plug 1 of the present invention will be described with reference to FIG. 4. This molding plug 1 is the same as the molding plug 1 of the first embodiment described above except that the plug surface 4
Opening notches 41a communicating with the recesses 41x are formed at two vertically opposed positions on the outer peripheral edge of 1.

In this embodiment, even if a water droplet penetrates between the plug surface 41 of the molded plug 1 and the surface of the outlet 10, the water droplet travels through the recess 41x and is discharged from the lower release notch 41a, so that the recess is formed. 41x is prevented from staying. As a result, it is possible to prevent the short circuit between the blades 3 and 3 due to the fact that the base peripheral edge 411 of the blade 3 is isolated in an island shape, and it is possible to prevent the occurrence of the tracking phenomenon for a long period of time.

In this embodiment, the plug surface 4
The open notch 4 is provided at two vertically opposed positions on the outer peripheral edge of
Although 1a is formed, it may be formed in two left and right opposite positions depending on the relationship with the outlet 10a of the outlet 10, and the number thereof is not limited to two. That is, the plug surface 41 of the molded plug 1
Since water droplets that have entered between the outlet and the surface of the outlet 10 may be discharged or the moisture may be dried, there may be one open notch 41a, and depending on the shape of the molding plug 1, Three or more pieces may be formed on the outer peripheral edge of the plug surface 41.

By the way, in these examples, although the occurrence of the tracking phenomenon can be prevented for a long period of time, since the plug body 4 is molded of a flexible insulating material, the heat resistance against abnormal temperature rise is high. I have a problem. Therefore, in the third embodiment of the molded plug 1 shown in FIG. 5, the heat resistance is improved together with the tracking resistance and the gap between the blades can be maintained even when the abnormal temperature rises.

That is, the third of the molding plug 1 shown in FIG.
In the embodiment, the blade 3 to which the cord 2 is connected and the insertion hole 5a into which the blade 3 can be inserted are formed, and a heat-resistant insulating material such as urea resin, melamine phenol resin, unsaturated polyester resin, or the like is used. It is composed of a plug base 5 formed of a curable resin and a plug body 4 integrated with the plug base 5 and molded of a flexible insulating material. The plug surface 51 of the plug base 5 is provided with a plug. A concave portion 51x is formed while leaving the root edge 511 of the blade 3 in an island shape.

To mold such a molding plug 1,
The plug base 5 is molded in advance with a heat resistant insulating material, and the plug blade 3 having the cord 2 connected thereto is inserted into the insertion hole 5a of the plug base 5, and then the plug blade 3 and the plug base 3 are formed in a molding die (not shown). It is possible to mold by disposing 5 and closing the mold to fill the flexible insulating material.

In addition to the through hole 5b formed in the plug base 5, a peripheral groove 5c is formed in the end face on the side connected to the plug body 4, and the through hole 5b and the peripheral groove 5c are formed. The plug base 5 is integrated with the plug body 4 by filling the plug body 4 with the flexible insulating material, and the plug body 4 is prevented from rolling up.

In the molded plug 1 as described above, the creepage distance between the plug blades 3 can be increased and the plug surface 51 which is in close contact with the surface of the outlet 10 can be formed as in the above-described embodiment. A constant space can be formed between the plug surface 51 and the surface of the outlet 10 except the outer peripheral edge.

Therefore, the molded plug 1 is connected to the outlet 1
Even if water droplets intrude into the surface of the outlet 10 in the state of being plugged in 0, as described above, the plug surface 51 that is in close contact with the surface of the outlet 10 due to the capillary phenomenon.
It is possible to prevent the short circuit between the blades 3 and 3 by wrapping around along the outer peripheral edge of the blade, and even if water droplets fall into the recess 51x, the root edge 511 of the blade 3 is isolated in an island shape. Moreover, since a fixed space is formed between the surface of the outlet 10 and the surface of the outlet 10, short-circuiting does not occur unless the recess 51x is infiltrated to the extent that the blades 3, 3 are connected. As a result, the occurrence of the tracking phenomenon can be further prevented for a long period of time in combination with the use of urea resin or the like having excellent tracking resistance.

On the other hand, even when the temperature rises abnormally due to poor contact between the blade 3 and the blade receiving metal fitting (not shown) of the outlet 10, the plug base 5 is softened by being formed of a heat-resistant insulating material. It is possible to maintain the gap between the blades 3 and 3 at a constant interval without performing the operation.

Further, in the above-mentioned third embodiment, the plug surface 51 of the plug base 5 formed of the heat resistant insulating material.
Although the plug surface of the molded plug 1 was formed by using the plug base 5 as in the fourth embodiment of the molded plug 1 shown in FIG.
The plug surface of the molded plug 1 may be formed by the plug surface 51 of 1 and the plug surface 41 of the plug body 4 which is continuous with the plug surface 51 of the plug base 5. That is, in the fourth embodiment of the molded plug 1, as shown in FIG. 6, the plug body 4 is formed so as to surround the outer peripheral surface of the plug base 5, and the end surface thereof is the plug surface 51 of the plug base 5. It is formed on the continuous plug surface 41.

Since the plug body 4 is integrated with the plug base 5 by wrapping around the outer peripheral edge of the plug base 5, the plug base 5 is prevented from being separated from the plug body 4. .

Also in this embodiment, even if water droplets enter between the surface of the outlet 10 and the outlet 10,
In addition to the plug surface of the molded plug 1 that is in close contact with the surface, that is, the outer peripheral edge of the plug surface 51 of the plug base 5 and the plug surface 41 of the plug body 4, it does not fall into the recess 51x, and if water drops Even if it falls into the concave portion 51x, the concave portion 5 is enough to connect the blades 3 and 3.
No short circuit occurs unless 1x is infiltrated. As a result,
Coupled with the adoption of urea resin, which has excellent tracking resistance, it is possible to prevent the tracking phenomenon from occurring for a long time.

Further, even when the plug base 3 is made of a heat-resistant insulating material, the plug base 5 is not softened even when the temperature rises due to a poor contact between the plug blade 3 and the blade receiving fitting of the outlet 10. It is possible to maintain a constant interval between 3 and 3.

Further, although not shown in detail in the third and fourth embodiments described above, as shown in the second embodiment, an appropriate number of open notches are formed on the outer peripheral edge of the plug surface. To secure communication between the recess 51x and the outside air,
The water droplets that have entered x may be promptly discharged or the moisture may be dried.

[0031]

As described above, according to the molded plug of the first aspect, only the root peripheral edge of each blade is formed on the plug surface of the plug body which surrounds the pair of blades and is molded with the flexible insulating material. The island-shaped recessed part allows the creepage distance between the pair of blades to be increased, and when the plug is inserted into the outlet, it is separated from the surface of the outlet except for the outer peripheral edge of the plug surface. It is possible to form a certain space, and even if moisture etc. intervenes between the surface of the outlet and the plug surface, there is no short circuit between the pair of blades and the occurrence of tracking phenomenon can be prevented for a long time. You can

According to the molded plug of the third aspect, a pair of plug blades to which a cord is connected, a plug base provided with the pair of plug blades and molded of a heat resistant insulating material, and a plug base. It consists of a plug body that is integrated and molded with a flexible insulating material, and by forming a recess on the plug surface of the plug base leaving only the root periphery of each blade in an island shape,
The creepage distance between a pair of blades can be increased, and when it is inserted into an outlet, a constant space can be formed between the outlet and the surface of the outlet except the outer peripheral edge of the plug surface. Even if moisture or the like is present between the plug surface and the plug surface, the pair of blades is not short-circuited, and the occurrence of the tracking phenomenon can be prevented for a long period of time. Further, even when the abnormal temperature rises due to poor contact when the outlet is inserted, the pair of blades can be maintained at a constant interval.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of a molded plug of the present invention.

2 is a side view of the molding plug of FIG. 1. FIG.

FIG. 3 is a sectional view taken along line ZZ of FIG.

FIG. 4 is a plan view showing a second embodiment of the molded plug of the present invention with a part thereof cut away.

FIG. 5 is a sectional view showing a third embodiment of the molding plug of the present invention.

FIG. 6 is a sectional view showing a fourth embodiment of the molding plug of the present invention.

[Explanation of symbols]

1 molded plug 2 codes 3 blades 4 plug body 41 plug side 411 Edge of the blade 41x recess 41a release notch 5 plug base 51 plug surface 511 The peripheral edge of the blade 51x recess 10 outlets

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-124621 (JP, A) JP-A-50-8086 (JP, A) SAIKAI HEI 5-97067 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) H01R 13/44 H01R 13/46 H01R 13/502

Claims (4)

(57) [Claims] 1. A pair of plug pins connected code consists plug body that is molded in flexible insulating material surrounding the pair of <br/> plug pins, each blade on the plug surface of the plug body The root of the
A molded plug characterized in that a recess is formed while leaving only the island shape. 2. One or a plurality of release notches communicating with the recess are formed on the outer peripheral edge of the plug surface of the plug body.
Molding plug of claim 1, wherein that. A pair of plug blades wherein the connecting cord, a pair of <br/> plug pins are disposed, and a plug body that is molded of heat-resistant insulating material, is integrated with the plug body, flexibility molded plug, wherein an insulating material consists molded plug body, the recess leaving only islands underlying the periphery of each <br/> plug pins on the plug surface of the plug body is formed. Wherein the outer peripheral edge of the plug face of the molded plug formed by the plug surface of the plug body, or continuously in a plug surface of the plug body surrounding the outer peripheral surface of the plug face and the plug body of the plug body molding plug of claim 3, wherein one communicating with the recess in the outer peripheral edge of the plug face of the molded plug formed by the plug surface of the plug body or a plurality of release notch is formed was <br/>.