JP2013254676A - Method for manufacturing attachment plug - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an attachment plug capable of preventing tracking and carbonization in the internal part thereof and excellent in tracking-resistance and heat-resistance.SOLUTION: In a manufacturing method for an attachment plug, after each plug prong 3 with a conduction wire 21 of a cord 2 connected thereto is inserted into each plug prong insertion hole 52b of a core 5, an inner layer part 6A of a plug body 1z is subjected to injection molding with thermoplastic resin of either one of elastomer and modified vinyl chloride, so as to cover a tip end part of the cord 2 where the conduction wire 21 is exposed towards rear side from the rear end of the core 5 and a base portion of each plug prong 3 with the conduction wire 21 connected thereto. Then, an outer layer part 6B of the plug body 1z is subjected to injection molding with thermoplastic resin of either one of elastomer and vinyl chloride, so as to cover an outer surface of the core 5 other than a front end surface from which the plug prongs 3 are projected, the inner layer part 6A exposing towards the rear side from the rear end of the core 5 and the tip end part of the cord 2 exposing towards the rear side than the rear end of the inner layer part 6A.

Description

  The present invention relates to a method of manufacturing a plug for use in supplying power to, for example, a plug for charging an electric vehicle or a hybrid vehicle, or a microwave oven, a toaster, an electronic device, an electric device, an electric appliance or the like.

  Conventionally, as the above-described plug, for example, a connecting portion between a plug blade protruding from the front end side of the plug and a cord is covered with a primary insulator made of a thermoplastic resin (polyamide), and the periphery of the primary insulator is vinyl chloride. A double insulated power plug of Patent Document 1 that is integrally molded with a secondary insulator made of

  However, the double-insulated power plug of Patent Document 1 has a poor insertion state of the plug blade with respect to, for example, a power outlet, and when the plug blade generates heat due to overcurrent, the primary insulator covered with the plug blade and the surrounding Since the coated secondary insulator is heated to a high temperature, each insulator is carbonized by the high heat. That is, since each insulator is carbonized, a conductive path with a small resistance is formed between the plug blades, and therefore tracking is likely to occur between the plug blades inside the plug. In addition, there is a problem that the plug generates heat and ignites due to repeated tracking.

Japanese Patent Laid-Open No. 9-306581

  An object of the present invention is to provide a method for manufacturing an insertion plug that can prevent tracking and carbonization from occurring inside the insertion plug, and is excellent in tracking resistance and heat resistance.

  According to the present invention, a plug blade is connected to each of the plurality of conductive wires exposed at the tip of the cord, and covers the tip of the cord where the lead of the cord is exposed and the base of the plurality of plug blades to which the lead is connected. A method for manufacturing an insertion plug in which a plug body is injection-molded with an insulating thermoplastic resin, wherein the plug blade to which the lead wire of the cord is connected is inserted into the plug blade of a core molded with a thermoplastic resin The plug blades that are inserted through the holes are regulated to be spaced apart from each other by a predetermined distance, and the distal end side of the plug blade protrudes forward from the front end of the core by a predetermined length. After the rear end side protrudes a predetermined length from the rear end of the core toward the rear side and supports the state, the front end portion where the conductor of the cord on the rear side from the rear end of the core is exposed, and the conductor Elastomer and modified vinyl chloride so as to cover the base of the plug blade to which The inner layer portion is injection-molded with any one of the thermoplastic resins, and the outer surface of the core excluding the front end surface on which the plug blade protrudes and the rear surface exposed from the rear end of the core are exposed. In order to cover the inner layer portion and the tip end portion of the cord exposed to the rear side from the rear end of the inner layer portion, the outer layer portion is injection-molded with a thermoplastic resin of either elastomer or vinyl chloride, The inner layer portion and the outer layer portion constitute the plug body.

  According to the present invention, it is possible to prevent an occurrence of tracking or carbonization inside the plug body, and it is possible to manufacture an insertion plug excellent in tracking resistance and heat resistance.

  Specifically, the plug blade to which the lead wire of the cord is connected is inserted into the plug blade insertion hole of the core formed of a thermoplastic resin and the adjacent plug blades are regulated at a predetermined interval, The front end side of each plug blade projects a predetermined length from the front end of the core toward the front side, and the rear end side of each plug blade is supported in a state of projecting a predetermined length from the rear end of the core toward the rear side. .

  Subsequently, the connection between the plurality of conductors exposed from the tip of the cord and the blade connected to each of the conductors is separated from the core by a predetermined distance from the rear end of the core. The inner layer portion is injected with one of the thermoplastic resin of elastomer or modified vinyl chloride so as to cover the tip end portion where the lead wire of the rear cord is exposed and the base portion of the plug blade to which the lead wire is connected. Mold.

  After this, the outer surface excluding the front end surface on which the core plug blade protrudes, the inner layer portion exposed rearward from the rear end of the core, and the cord exposed rearward from the rear end of the inner layer portion The outer layer portion is injection molded with either one of an elastomer and a vinyl chloride thermoplastic resin so as to cover the tip portion.

  That is, the rear end side of the plug blade to which the conducting wire is connected is supported in a state protruding a predetermined length from the rear end of the core to the rear side, and a plurality of conducting wires exposed from the tip end portion of the cord, While the connecting portion between each lead wire and the plug blade connected to each of the lead wires is regulated at a predetermined interval by the core, the tip portion where the lead wire of the cord is exposed and the plug to which the lead wire is connected Since the inner layer part is injection-molded with either thermoplastic resin or modified vinyl chloride so as to cover the base of the blade, the spacing and position between the connecting parts are not displaced, and the insulation is It can coat | cover reliably, keeping at the space | interval obtained.

Further, since the inner layer portion is formed integrally with the core to which the plug blade is assembled, it is possible to ensure the strength necessary for maintaining the gap between the connecting portions at an insulating property. Furthermore, since the inner layer portion of the plug body is injection-molded with either one of the thermoplastic resin of elastomer or modified vinyl chloride, the outer layer portion of the plug body is made of an inexpensive heat which is less insulating than the elastomer or modified vinyl chloride. It can be molded with a plastic resin.
As a result, it is possible to reliably insulate the connection portions between the plurality of conductive wires exposed from the tip portion of the cord and the plug blades connected to the respective conductive wires.

  As an aspect of the present invention, a plug blade is connected to each of the plurality of conductors exposed at the tip of the cord, the tip of the cord exposed to the lead, and the base of the plurality of blades to which the conductor is connected, A plug plug manufacturing method in which a plug body is injection-molded with an insulating thermoplastic resin so as to cover the tip of the plug blade, to which the lead wire of the cord is exposed, and the plug blade to which the lead wire is connected. The inner layer portion is injection-molded with one of the thermoplastic resin of elastomer or modified vinyl chloride so as to cover the base portion, and the plurality of plug blades are restricted to a state separated by a predetermined interval in the inner layer portion. In addition, the front end side of the plug blade is supported in a state protruding a predetermined length from the front end of the inner layer portion toward the front side, and the plug blade protruding forward from the front end of the inner layer portion is made of thermoplastic resin. Insert it into the blade insertion hole of the core molded with After assembling in a state in which the front end side of the plug blade protrudes a predetermined length from the front end of the core toward the front side, the outer surface excluding the front end surface on which the plug blade of the core protrudes, and the core Either the elastomer or the improved vinyl chloride so as to cover the inner layer portion exposed to the rear side from the rear end and the tip portion of the cord exposed to the rear side from the rear end of the inner layer portion. An outer layer portion can be injection-molded with a thermoplastic resin, and the plug body can be constituted by the inner layer portion and the outer layer portion.

  According to the present invention, it is possible to manufacture an insertion plug that has the above-described tracking resistance and heat resistance and has excellent assemblability.

More specifically, the inner layer portion is covered with one of an elastomer and a modified vinyl chloride thermoplastic resin so as to cover the tip end portion where the lead wire of the cord is exposed and the base portion of the plug blade to which the lead wire is connected. Injecting and regulating the connection between the plurality of conductors exposed from the tip of the cord and the blade connected to each of the conductors to a state separated by a predetermined interval by the inner layer part The tip end side of the plug blade is supported in a state of protruding a predetermined length from the front end of the inner layer portion toward the front side.
Thereafter, the plug blade protruding forward from the front end of the inner layer portion is inserted into the plug blade insertion hole of the core formed of thermoplastic resin, and the distal end side of each plug blade is directed forward from the front end of the core. Assemble in a state protruding by a predetermined length.

  Subsequently, the outer surface excluding the front end surface on which the core blade is projected, the inner layer portion exposed rearward from the rear end of the core, and the cord exposed rearward from the rear end of the inner layer portion The outer layer portion is injection-molded with one of the thermoplastic resin of elastomer and modified vinyl chloride so as to cover the tip portion.

  That is, the leading end side of the plug blade to which the conducting wire is connected is supported in a state protruding a predetermined length from the front end of the inner layer portion to the front side, and a plurality of conducting wires exposed from the leading end portion of the cord and each of the conducting wires The plug blade protruding forward from the front end of the inner layer portion was molded with a thermoplastic resin while the connection between the plug blade blades connected to each of the inner blade portions was regulated at a predetermined interval by the inner layer portion. Since it is inserted through the core blade insertion hole of the core and assembled, the interval and position between the connecting portions are not displaced, and the assembly can be performed while maintaining the interval at which insulation is obtained.

  In addition, since the cord and the blade are integrally assembled by the inner layer portion, the cord, the blade and the inner layer portion can be handled as a single component, and the distance between the connecting portions can provide insulation. The cord, the blade, and the inner layer portion can be integrally assembled to the core while maintaining the above.

Moreover, since the inner layer portion of the plug body is injection-molded with one of the thermoplastic resin of elastomer and modified vinyl chloride, the outer layer portion of the plug body is made of an inexpensive heat which is less insulating than the elastomer or modified vinyl chloride. It can be molded with a plastic resin.
As a result, it is possible to reliably insulate the connection portions between the plurality of conductors exposed from the tip of the cord and the plug blades connected to each of the conductors, and obtain insulation between the connection portions. It is possible to assemble it as a single piece while maintaining a certain distance.

Further, as an aspect of the present invention, a plug blade is connected to each of a plurality of conductors exposed at the tip of the cord, and a tip portion where the conductor of the cord is exposed and a plurality of plug blades to which the conductor is connected An insert plug manufacturing method in which a plug body is injection-molded with an insulating thermoplastic resin so as to cover a base portion, wherein a plug blade to which the lead wire of the cord is connected is molded with a thermoplastic resin The plug blades are inserted into the blade insertion holes of the blades and the adjacent blades are regulated at a predetermined interval, and the distal end side of the blades is protruded from the front end of the core by a predetermined length, After supporting the state where the rear end side of the plug blade protrudes a predetermined length from the rear end of the core toward the rear side, the outer surface excluding the front end surface on which the plug blade of the core protrudes; The leading end of the lead wire exposed behind the rear end of the core and the lead wire are in contact with each other. Has been said to cover the base of the plug pins, the plug body in one of the thermoplastic resin with the elastomer and improve vinyl chloride can be injection molded.
According to the present invention, it is possible to manufacture an insertion plug having excellent formability while having tracking resistance and heat resistance.

  Specifically, the plug blade to which the lead wire of the cord is connected is inserted into the plug blade insertion hole of the core formed of a thermoplastic resin and the adjacent plug blades are regulated at a predetermined interval, The front end side of each plug blade is protruded by a predetermined length from the front end of the core toward the front side, and the rear end side of each plug blade is supported in a state of protruding a predetermined length from the rear end of the core toward the rear side. After that, elastomer and modified vinyl chloride so as to cover the outer surface excluding the front end surface where the core blade of the core protrudes, the tip portion where the lead wire of the cord is exposed, and the base portion of the blade blade to which the wire is connected The plug body is injection-molded with any one of the thermoplastic resins.

  That is, the rear end side of the plug blade to which the conducting wire is connected is supported in a state protruding a predetermined length from the rear end of the core to the rear side, and a plurality of conducting wires exposed from the tip end portion of the cord, While the connecting portion between each lead wire and the plug blade connected to each of the lead wires is regulated at a predetermined interval by the core, the tip portion where the lead wire of the cord is exposed and the plug to which the lead wire is connected The plug body is injection-molded with one of the thermoplastic resin of elastomer or modified vinyl chloride so as to cover the base of the blade. It can coat | cover reliably, keeping at the space | interval obtained.

  Further, since the plug body is injection-molded with one thermoplastic resin, the tip end portion where the lead wire of the cord is exposed and the base portions of the plurality of plug blades to which the lead wire is connected can be covered at the same time.

As a result, it is possible to reliably insulate the connection portions between the plurality of conductive wires exposed from the tip portion of the cord and the plug blades connected to the respective conductive wires. Furthermore, the step of insulating between the connecting portions of the plurality of conductive wires exposed from the tip of the cord and the plug blades connected to each of the conductive wires and the step of injection molding the plug body can be performed at the same time. Simplification of the manufacturing process for manufacturing and improvement of work efficiency can be achieved.
Note that if the plug body is formed only of vinyl chloride, the plug can be manufactured at low cost.

The above-described elastomer can be composed of, for example, an olefin elastomer, a styrene elastomer, a urethane elastomer, an ester elastomer, a polyamide elastomer, or the like.
The improved vinyl chloride can be composed of, for example, a compound obtained by blending a predetermined amount of an ethylene polymer and calcium carbonate with respect to vinyl chloride.
Furthermore, the vinyl chloride can be composed of, for example, polyvinyl chloride, vinyl chloride polymer, vinyl chloride resin, vinyl chloride homopolymer or the like.

As an aspect of the present invention, the improved vinyl chloride can be constituted by blending a predetermined amount of an ethylene polymer and calcium carbonate with respect to the vinyl chloride.
The above-mentioned ethylene-based polymer can be composed of an ethylene-based copolymer manufactured by Mitsui DuPont Polychemical Co., Ltd. Calcium carbonate can be composed of, for example, calcium bicarbonate, light calcium carbonate, or the like.

  According to the present invention, it is possible to improve the moldability, dimensional stability, and tracking resistance of the plug, and to manufacture the plug having excellent disconnection spark characteristics with high accuracy according to the dimensions.

  More specifically, tracking resistance is improved by blending the above-described ethylene-based polymer into vinyl chloride. In addition, since the ethylene-based polymer is more compatible with vinyl chloride than the conventional ethylene-acrylic acid ester-polar monomer copolymer, it is possible to obtain a molecularly homogeneous compound. .

  In addition, since the ethylene-based polymer has excellent filler filling characteristics, the compound containing the ethylene-based polymer can be used as a material for molding a power cord plug or cord with high accuracy according to the dimensions. .

  Moreover, if the weight part of calcium carbonate mix | blended with vinyl chloride is adjusted, the viscosity and fluidity | liquidity of a compound can be set according to molded articles, such as a plug and a cord, and the shaping | molding precision of a molded article improves.

  Further, as an aspect of the present invention, a connecting portion in a range extending from the outer surface on the front side to the crimping portion where the conducting wire of the plug blade is crimped and connected to the outer surface on the rear side from the exposed end portion exposing the core wire of the conducting wire. Then, it can be covered with a tape-like insulator which is wound several times as appropriate so as to cover the entire connecting portion.

According to the present invention, it is possible to further improve the insulation between adjacent connecting portions and prevent tracking due to a short circuit between the connecting portions.
More specifically, a tape-like insulator is wound around the connecting portion where the conducting wire and the plug blade are connected appropriately, and is covered so as to cover the entire connecting portion, and then from above the insulator covering the connecting portion. The plug body is integrally formed with the thermoplastic resin so as to cover the whole of the connection portion and the insulator.

As a result, in addition to the insulating effect by the thermoplastic resin, the insulating effect by the tape-like insulator is obtained in synergy, so that the insulation is higher than the insulation by either the thermoplastic resin or the tape-like insulator. Sex is obtained.
As a result, it is possible to more reliably insulate between the connecting portions where the conducting wires and the plug blades are connected by the synergistic effect of the thermoplastic resin and the tape-like insulator.

  That is, since the adjacent connection portions are insulated by the tape-like insulator, no conductive path is formed between the connection portions, and tracking due to a short circuit between the connection portions can be prevented. Moreover, since the heat generation by the short circuit between tracking parts and tracking is prevented, it can prevent that the thermoplastic resin which covers a connection part carbonizes.

  Furthermore, since the tape-like insulator has flexibility, it can be wound in a state of being in close contact with, for example, a connecting portion having unevenness, and a foreign substance (for example, a cause of tracking) Intrusion of moisture, oil, dust, fibers, etc.) can be prevented.

  For example, even if the plug plug is not plugged into the outlet and the plug blade is heated due to overcurrent, and the thermoplastic resin coated on the plug blade is carbonized, the adjacent connection parts are insulated by a tape-like insulator. Therefore, it is possible to prevent a conductive path from being formed between the connecting portions. Further, it is possible to reliably prevent a short circuit between adjacent connection portions regardless of carbonization of the thermoplastic resin.

Moreover, as an aspect of the present invention, the tape-like insulator can be composed of a glass cloth tape.
According to this invention, it is possible to improve the durability by increasing the connection strength of the connection portion where the conducting wire and the plug blade are connected.

  More specifically, the glass cloth tape is wound several times around the connecting portion where the conducting wire and the plug blade are connected to cover the entire connecting portion, and then covered from above the glass cloth tape covering the connecting portion. Thus, since the plug body is integrally formed of a thermoplastic resin, in addition to the insulating effect of the thermoplastic resin, the strength necessary to keep the adjacent connection portions of the glass cloth tape insulated. can get.

  In other words, since the connection strength of the connection portion can be increased by the characteristics of the glass cloth tape, for example, when a load (stress) such as bending, twisting, or tension is applied to the connection portion, Further, it is possible to prevent disconnection of the core wire of the conducting wire and to improve heat resistance and connection strength.

Moreover, as an aspect of the present invention, the tape-like insulator can be made of a mica tape.
According to this invention, the heat resistance of the connection part to which the conducting wire and the plug blade are connected can be increased, and the insulation between the connection parts can be prevented from being reduced by heat generation.

  More specifically, the mica tape is wound around the connecting portion where the conducting wire and the plug blade are connected appropriately and covered so as to cover the entire connecting portion, and then the mica tape covering the connecting portion is covered from above. Since the plug body is integrally formed of thermoplastic resin, in addition to the insulating effect of thermoplastic resin, the heat resistance effect of mica tape can be obtained in synergy.

In other words, the mica tape has a higher heat resistance temperature than the glass cloth tape described above, and the insulation properties may be impaired even if the mica tape is heated to a temperature higher than the heat resistance temperature of the glass cloth tape due to heat generated by the plug blade due to overcurrent. Therefore, the heat resistance can be improved.
In addition, you may wind combining the above-mentioned mica tape and glass cloth tape in combination or in combination, and both the connection strength and heat resistance can be improved with the characteristic of both tapes.

  According to the present invention, it is possible to prevent tracking and carbonization from occurring inside the plug body, and it is possible to manufacture an insertion plug excellent in tracking resistance and heat resistance.

The vertical side view of the insertion plug of 1st Embodiment. Structure explanatory drawing of a 1st core. The structure explanatory drawing of the 2nd core. Explanatory drawing explaining the winding state of a tape-shaped insulator. Explanatory drawing explaining the manufacturing method of the insertion plug of 1st Embodiment. Explanatory drawing of the process of injection-molding the outer-layer part of the outer skin of 1st Embodiment. Explanatory drawing explaining the manufacturing method of the plug of 2nd Embodiment. Explanatory drawing explaining the manufacturing method of the insertion plug of 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal side view of the insertion plug 1A of the first embodiment, FIG. 2 is a configuration explanatory view of a first core 51, and FIG. 3 is a configuration explanatory view of a second core 52.

  2A and 2B are explanatory views of the configuration of the first core 51. FIG. 2A is a front view of the first core 51, FIG. 2B is a bottom view of the first core 51, and FIG. ) Is a cross-sectional view of the first core 51 shown in FIG.

  3A and 3B are explanatory views of the configuration of the second core 52. FIG. 3A is a rear view of the second core 52, FIG. 3B is a plan view of the second core 52, and FIG. ) Is a cross-sectional view taken along line CC of the second core 52 shown in FIG. 3A, and FIG. 3D is a cross-sectional view taken along line DD of the second core 52 shown in FIG.

(First embodiment)
The plug 1A according to the first embodiment is a straight type plug in which the plug blades 3 and 3 and the ground electrode 4 are connected to the cord 2 in a straight line in the longitudinal direction A, and the rear end of the plug body 1z. A cord 2 continuously provided on the side, a pair of plug blades 3 and 3 and a grounding electrode 4 projecting on the front end side of the plug main body 1z, and a core 5 for supporting the plug blades 3 and 3 and the grounding electrode 4 The outer end 6 of the cord 2 and the outer skin 6 covering the core 5 are provided.
In the present embodiment, one of the plug blades 3 and 3 and the ground electrode 4 protruding is set as the front end side or the front side, and the other is set as the rear end side or the rear side.

  In the present embodiment, the above-described cord 2 is composed of two conductive wires 21 and 21 (shown only in the front side in FIG. 2) and one ground wire 22. Each of the conductive wire 21 and the ground wire 22 has a configuration in which the outer circumferences of the core wires 21a and 22a formed by bundling a plurality of conductive wire conductors are covered with insulating materials 21b and 22b made of an insulating resin, At each tip, the insulating materials 21b and 22b are removed, and the core wires 21a and 22a are exposed.

  The conducting wire 21 is connected by crimping the exposed end of the core wire 21a exposed from the tip of the insulating material 21b to the crimping portion 3a formed at the base of the plug blade 3, and connecting the tip of the conducting wire 21 to the plug blade 3. ing.

  The ground wire 22 is connected by crimping the exposed end portion of the core wire 22a exposed from the tip of the insulating material 22b to the crimp portion 4a formed at the base of the ground electrode 4, and the tip of the ground wire 22 is connected to the ground electrode 4. Connected to.

  Further, the cord 2 has a configuration in which the conductive wires 21 and 21 and the ground wire 22 are covered with an insulating exterior portion 2a while being bundled into one, and at the distal end portion, the exterior portion 2a is removed, The conducting wires 21 and 21 and the ground wire 22 are exposed for a predetermined length from the tip of the exterior portion 2a.

  Furthermore, a tape-like insulator 7 having insulating properties and heat resistance is appropriately wound around the connecting portion 23 in which the core wire 21a of the conducting wire 21 is crimped and connected to the crimping portion 3a of the plug blade 3. .

Next, with reference to FIG. 4, a winding method for winding the tape-like insulator 7 will be described.
4A and 4B are explanatory views for explaining a winding state of the tape-like insulator 7, wherein FIG. 4A is a side view of the state in which the glass cloth tape 7A is wound, and FIG. 4B is a winding of the mica tape 7B. FIG.

  The tape-like insulator 7 is composed of a glass cloth tape 7A having excellent mechanical strength and a mica tape 7B having a heat resistance higher than that of the glass cloth tape 7A, and is used according to the type and use of the plug 1A. It is done.

  As shown in FIGS. 4A and 4B, the glass cloth tape 7A and the mica tape 7B are formed from the outer peripheral surface on the front side of the crimping portion 3a of the plug blade 3 to which the core wire 21a of the conducting wire 21 is crimped and connected. Several windings are appropriately wound so as to cover the entire connecting portion 23 set in a range straddling the rear outer surface rather than the exposed end portion of the exposed core wire 21a.

  Thereby, between the pair of connection parts 23 to which the plug blade 3 and the conductive wire 21 are connected is kept in an insulated state by the glass cloth tape 7A or the mica tape 7B wound so as to cover the entire connection part 23. Can do.

  Moreover, since the glass cloth tape 7A and the mica tape 7B have flexibility, the glass cloth tape 7A and the mica tape 7B can be wound in close contact with the outer peripheral surface of the connection portion 23. For this reason, it is possible to prevent foreign matters (for example, moisture, oil, dust, fibers, etc.) that cause tracking from entering the inside of the connection portion 23.

Further, a band-like binding band 25 is wound around the outer peripheral surface of the outer side of the exterior portion 2a in close contact with the outer peripheral surface on the rear side from the exposed end portion of the exterior portion 2a of the cord 2.
The binding band 25 is embedded in the outer skin 6 when the outer skin 6 is injection-molded so that the distal end portion of the cord 2 is covered in the manufacturing method described later.

  Thus, for example, when a load (stress) such as bending, twisting, or tension is applied to the cord 2, the binding band 25 wound around the cord 2 is locked inside the outer skin 6, so that the load is applied to the plug blade. 3 can be prevented from being directly added to the connecting portion between the lead wire 21 and the conductive wire 21.

  As a result, it is possible to prevent disconnection from occurring in the connection portion between the conductive wire 21 and the plug blade 3, the core wire 21a of the conductive wire 21, or the like. Further, it is possible to prevent foreign matters such as moisture and dust from entering the plug through the gap between the cord 2 and the outer skin 6.

  In the present embodiment, as shown in FIGS. 2 and 3, the core 5 includes a first core 51 and a second core 52 formed of different materials. The first core 51 is made of polybutylene terephthalate resin (PBT) that is harder than the second core 52. Further, the second core 52 is made of a melamine resin having a higher insulating property than the first core 51.

  As shown in FIG. 2, the first core 51 has a pair of fitting portions 51a having a convex shape with the front end of the above-described plug blades 3, 3 and the ground electrode 4 protruding a predetermined length. 51 a is formed at both lower ends of the front end side of the first core 51.

  Further, a polygonal (here, regular hexagonal) first grounding electrode insertion hole 51b corresponding to the shape of the grounding electrode 4 is formed in the intermediate part between the fitting parts 51a and 51a in the longitudinal direction A. ing. Furthermore, an engaged portion 51c having a fitting recess 51d is formed in the upper center of the rear end side of the first core 51.

As shown in FIG. 3, the second core 52 is formed with a pair of fitting holes 52 a and 52 a that can be fitted with the fitting portion 51 a of the first core 51 on both sides of the center of the second core 52. Has been established.
A pair of plug blade insertion holes 52b and 52b corresponding to the shape of the plug blades 3 and 3 are formed in the longitudinal direction A below the pair of fitting holes 52a and 52a. Further, a circular second grounding electrode insertion hole 52c corresponding to the shape of the grounding electrode 4 is formed in the middle portion between the fitting holes 52a and 52a in the longitudinal direction A.

In the above-described core 5, the base portions of the plug blades 3, 3 are covered with the second core 52 by inserting the plug blades 3, 3 into the plug blade insertion holes 52 b, 52 b of the second core 52. .
In other words, the relative position between the first core 51 and the second core 52 is determined by the fitting between the fitting portion 51a of the first core 51 and the fitting hole 52a of the second core 52. It has become.
Further, by the above-described positioning, the first grounding electrode insertion hole 51b and the second grounding electrode insertion hole 52c communicate with each other as shown in FIG. 1 to form one continuous grounding electrode insertion hole 53. .

  In the present embodiment, by inserting the ground electrode 4 through the above-described ground electrode insertion hole 53, the base portion of the ground electrode 4 is covered with the first core 51 and the second core 52. The grounding electrode 4 is disposed at an intermediate portion between the pair of fitting portions 51a and 51a (fitting holes 52a and 52a), and the first and second cores 51 in the direction orthogonal to the longitudinal direction A are provided. The relative position between 52 is positioned.

Here, in the first core 51, only the base portion of the ground electrode 4 is covered, while in the second core 52, the plug blades 3 and 3 and the base portion of the ground electrode 4 are covered.
Further, in the ground electrode 4, a polygonal portion is formed thicker than others, and a stepped portion 41 is formed by this thick portion and other portions. As a result, when the ground electrode 4 is inserted into the ground electrode insertion hole 53, the boundary portion between the first and second ground electrode insertion holes 51b and 52c and the stepped portion 41 are fitted with no gap therebetween. 4 is positioned.

  By the way, the outer skin 6 is covered with an inner layer portion 6 </ b> A that covers the connecting portion 23 connecting the cord 2 (conductive wire 21) and the plug blade 3 and the connecting portion 24 connecting the cord 2 and the ground electrode 4. And an outer layer portion 6B that is covered so as to cover the inner layer portion 6A.

The inner layer portion 6A and the outer layer portion 6B are made of softer materials than the first core 51 and the second core 52, and are made of improved vinyl chloride and vinyl chloride having insulation properties.
As shown in FIG. 1, the inner layer portion 6 </ b> A made of the improved vinyl chloride is exposed to the rear side from the rear end of the core 5, as shown in FIG. 1. Are connected so as to cover the connection part 23 connecting the cord 2 and the grounding electrode 4.

That is, the inner layer portion 6A includes a distal end portion where the conducting wires 21 and 23 of the cord 2 are exposed, a base portion of the plug blade 3 to which the conducting wire 21 is connected, and a proximal end portion of the ground electrode 4 to which the conducting wire 23 is connected. It is injection molded to cover it.
The outer layer portion 6B made of vinyl chloride includes an outer surface excluding the front end surface on which the plug blade 3 and the ground electrode 4 of the core 5 are projected, and an inner layer exposed rearward from the rear end of the core 5. Injection molding is performed so as to cover the portion 6A and the outer peripheral surface of the distal end side of the cord 2 exposed to the rear side from the rear end of the inner layer portion 6A.

  Further, in the outer skin 6, an opening 61 is formed in the outer skin 6 at a position corresponding to the engaged portion 51 c of the first core 51. As shown in FIG. 1, the engaged portion 51 c is exposed from the opening 61 to the outer surface of the insertion plug 1 </ b> A.

Further, the thermistor 18 for detecting the temperature of the exposed front end surface of the second core 52 is disposed in the center portion on the front end side of the second core 52.
The thermistor 18 is disposed substantially in the middle of the plug blades 3 and 3 and the ground electrode 4, and is housed in the central portion on the rear end side of the second core 52. In addition, between the exposed side front end surface of the second core 52 and the detection side front end portion of the thermistor 18, the temperature of the exposed side front end surface is formed to be thick enough to conduct heat directly to the thermistor 18. Yes.

  That is, since the temperature of the exposed front end face of the second core 52 is directly conducted to the thermistor 18, the current from the outlet (not shown) to the load device is not reached before reaching a high temperature at which tracking occurs. The supply can be interrupted by a current interrupt device 19 described later.

  The thermistor 18 is connected to one end side of signal lines 18 a and 18 a drawn from the tip of the cord 2. The other ends of the signal lines 18a and 18a are connected to a current interrupt device 19 for interrupting the supply of current from an outlet (not shown) to the load device.

  For example, when a load (stress) such as bending, twisting, or tension is applied to the cord 2, the signal line 18 a is allowed to break the signal line 18 a of the thermistor 18 before the core line 21 a of the conductor 21 is broken. It is made of a material that can be formed to have a wire diameter that is acceptable, or that disconnection is allowed.

Alternatively, the signal line 18a may be wired in a tensioned state with respect to the longitudinal direction A, and may be configured to be disconnected before the core wire 21a of the conducting wire 21 when the above-described load (stress) is applied.
The load device can be constituted by, for example, a battery mounted on an electric vehicle, a microwave oven, a toaster, an electric device, or the like.

  Based on the detection signal output from the thermistor 18, the current interrupt device 19 calculates the resistance value of the thermistor 18 that varies according to the temperature change of the exposed front end surface of the second core 52. The resistance value of the thermistor 18 is compared with a preset threshold value to determine whether or not the temperature of the exposed front end surface of the second core 52 is equal to or lower than a predetermined temperature.

  That is, when the temperature of the exposed front end surface of the second core 52 increases, the resistance value of the thermistor 18 decreases. Further, when the temperature of the exposed front end surface of the second core 52 decreases, the resistance value of the thermistor 18 increases. Therefore, the resistance value of the thermistor 18 that varies according to the temperature change of the exposed front end surface of the second core 52. By detecting this change, the temperature of the exposed front end surface of the second core 52 can be accurately determined.

When the temperature of the exposed front end surface of the second core 52 rises to a predetermined temperature or more and it is determined that the resistance value of the thermistor 18 is lower than a preset threshold value, the current interrupt device 19 connects the outlet to the load device. Shut off the current supply.
Thereby, it is possible to prevent the front end face of the insertion plug 1A from being overheated to a predetermined temperature or more, and preventing ignition due to the overheat.

  In addition, when the temperature of the exposed front end surface of the second core 52 drops below a predetermined temperature and it is determined that the resistance value of the thermistor 18 is higher than the threshold value, the supply of current from the outlet to the load device is continued. .

  Further, the current interrupt device 19 detects that no signal is output from the thermistor 18 when the signal line 18a of the thermistor 18 is disconnected and the circuit of the thermistor 18 is in an open state (disconnected state). Based on the above, the notifying means (not shown) notifies that the signal line 18a is disconnected.

  That is, in the state in which the plug 1A is inserted into the outlet, for example, when a load (stress) such as bending, twisting, or tension is applied to the cord 2, the signal of the thermistor 18 before the core wire 21a of the conducting wire 21 is disconnected. The line 18a is disconnected.

  When it is detected that the circuit of the thermistor 18 is in an open state (disconnected state) and no signal is output from the thermistor 18, based on the detection, a notification means (not shown) that the signal line 18 a is disconnected can be used. It can notify that there is a possibility that the conducting wire 21 may be disconnected.

  Thereby, the plug 1A can be replaced in a device or the like in which it is difficult to suddenly break the lead 21 before the lead 21 suddenly breaks and trouble occurs. As a result, it is possible to prevent a failure from occurring in the device.

Next, a manufacturing method for manufacturing the plug 1A of the first embodiment will be described with reference to FIGS.
FIG. 5 is an explanatory view for explaining the manufacturing method of the plug 1A of the first embodiment. FIG. 5 (a) shows the cord 2, the plug blades 3, 3, the grounding electrode 4, and the core 5. FIG. 5B is an explanatory diagram of a process of injection molding the inner layer portion 6A of the outer skin 6. Moreover, FIG. 6 is explanatory drawing of the process of injection-molding the outer layer part 6B of the outer skin 6 of 1st Embodiment.

  In the manufacture of the insertion plug 1A, first, the connecting portion 23 where the lead wire 21 of the cord 2 and the plug blade 3 are connected is covered with a glass cloth tape 7A that is wound several times as appropriate so as to cover the entire connecting portion 23. The adjacent connection portions 23 are insulated in advance.

  Next, as shown in FIG. 5 (a), the fitting portion 51a of the first core 51 is fitted into the fitting hole 52a of the second core 52, and the first and second in the insertion direction of the ground electrode 4 are fitted. The relative position between the two cores 51 and 52 is positioned. At this time, the first and second grounding electrode insertion holes 51b and 52c communicate with each other to form one continuous grounding electrode insertion hole 53.

Subsequently, the plug blades 3 and 3 to which the conductors 21 and 21 of the cord 2 are connected are covered with the glass cloth tape 7A while the entire connection portion 23 to which the conductor 21 and the blade 3 of the cord 2 are connected is covered with the glass cloth tape 7A. The plug blades are inserted through the corresponding plug blade insertion holes 52b and 52b of the second core 52, respectively, and the distal ends of the plug blades 3 and 3 are regulated to protrude from the front end of the second core 52 by a predetermined length. At the same time, the base is supported by the second core 52 of the core 5.
Further, the ground electrode 4 to which the ground wire 22 is connected is inserted into the corresponding ground electrode insertion hole 53, and the base portion thereof is supported by the first and second cores 51 and 52 of the core 5.

  As a result, the plug blades 3 and 3 and the grounding electrode 4 are supported in a state in which the distal end sides of the plug blades 3 and 3 and the grounding electrode 4 protrude from the front end of the second core 52 by a predetermined length. The rear ends of the plug blades 3 and 3 and the grounding electrode 4 are supported in a state of protruding a predetermined length from the rear end of the second core 52 toward the rear side.

  Further, the connecting portions 23 and 23 between the conducting wires 21 and 21 exposed from the tip end of the cord 2 and the plug blades 3 and 3 connected to the conducting wires 21 and 21 are separated by a core 5 at a predetermined interval. Regulated to the specified state.

  Next, with the cord 2, the plug blades 3, 3, the grounding electrode 4, and the core 5 being integrally assembled, they are set between an upper mold 8 a and a lower mold 9 a described later, and the outer skin 6 The inner layer portion 6A is injection molded (see FIG. 5B).

  In order to mold the inner layer portion 6A of the outer skin 6, as shown in FIG. 5B, the plug blades 3 and 3 and the ground electrode 4 to which the cord 2 is connected, and the plug blades 3 and 3 and the ground electrode 4 are supported. The assembled core 5 is inserted between the upper mold 8a and the lower mold 9a having the cavity of a predetermined shape.

  Thereafter, a modified vinyl chloride (specifically, a compound formed by blending a predetermined amount of an ethylene polymer and calcium carbonate with respect to vinyl chloride) is formed into a cavity formed between the upper mold 8a and the lower mold 9a. It injects in.

  That is, the inner layer portion 6A is connected to the distal end side outer peripheral surface where the conducting wire 21 and the ground wire 22 of the cord 2 on the rear side from the rear end of the core 5 are exposed, and the connecting portion 23 connecting the conducting wire 21 and the plug blade 3. Then, after injection molding so that the connection portion 24 connecting the ground wire 22 and the ground electrode 4 is covered, the upper die 8a and the lower die 9a are separated, and the component in which the inner layer portion 6A is injection molded is taken out.

  Next, in order to mold the outer layer portion 6B of the outer skin 6, a component in which the cord 2, the plug blades 3, 3, the grounding electrode 4, and the core 5 are integrally assembled by the inner layer portion 6A described above. As shown in FIG. 6, the upper die 8b and the lower die 9b having cavities of a predetermined shape are inserted.

  Thereafter, vinyl chloride (specifically, a thermoplastic resin such as polyvinyl chloride, vinyl chloride polymer, vinyl chloride resin, vinyl chloride homopolymer) is placed in the cavity formed between the upper die 8b and the lower die 9b. To ejaculate.

  That is, the outer layer portion 6B is formed by removing the engaged portion 51c of the first core 51, the outer surface excluding the front end surface on which the plug blade 3 and the grounding electrode 4 of the core 5 are projected, and the rear of the core 5. Injection molding is performed so as to cover the exposed outer surface of the inner layer portion 6A exposed to the rear side from the end and the distal end side outer peripheral surface of the cord 2 exposed to the rear side from the rear end of the inner layer portion 6A.

By the above-described injection molding, the outer skin 6 having the opening 61 for exposing the engaged portion 51c to the outer surface is integrally injection-molded. Thereafter, the upper die 8b and the lower die 9b are separated, and the plug body 1z on which the outer skin 6 is injection-molded is taken out, thereby completing the manufacture of the plug 1A shown in FIG.
Moreover, the cord 2, the plug blades 3 and 3, the ground electrode 4, and the core 5 can be integrated with no gap by injection molding the outer skin 6.

  The insertion plug 1A manufactured as described above is assembled by inserting the rear end side of the plug blade 3 to which the conducting wire 21 is connected into a state protruding from the rear end of the second core 52 by a predetermined length. Between the connecting portions 23 adjacent to each other inside the plug 1 </ b> A, the inner layer portion 6 </ b> A that is injection-molded so as to cover the connecting portions 23 is restricted to a state spaced by a predetermined interval.

Further, since the glass cloth tape 7A is wound around the connecting portion 23 where the conductor 21 of the cord 2 and the plug blade 3 are connected appropriately so as to cover the entire connecting portion 23, the plug body 1z Between the adjacent connecting portions 23 can be kept insulated by the glass cloth tape 7A wound so as to cover the connecting portions 23.
Thereby, while being able to insulate reliably between the connection parts 23, it can be assembled | attached integrally, keeping between the connection parts 23 in the space | interval which can obtain insulation.

  That is, since the connection parts 23 are insulated by the glass cloth tape 7A, no conductive path is formed between the connection parts 23, and it is possible to prevent tracking due to a short circuit between the connection parts 23. Furthermore, since heat generation due to a short circuit or tracking between the connecting portions 23 is prevented, it is possible to prevent the improved vinyl chloride and vinyl chloride coated between the connecting portions 23 and the connecting portions 23 from being carbonized.

For example, the insertion state of the insertion plug 1A with respect to the outlet is poor, and even if the thermoplastic resin coated on the plug blade 3 is carbonized due to heat generated by the plug blade 3 due to overcurrent, a conductive path is formed between the connecting portions 23. Can be prevented. Moreover, even if the situation which carbonizes to the thermoplastic resin which comprises the outer skin 6 does not arise, it can prevent that between the connection parts 23 short-circuits.
As a result, it is possible to prevent the occurrence of tracking and carbonization inside the insertion plug 1A, and it is possible to manufacture the insertion plug 1A having excellent tracking resistance and heat resistance.
Further, instead of the glass cloth tape 7A, the mica tape 7B is wound around the connection portion 23 where the lead wire 21 of the cord 2 and the plug blade 3 are connected appropriately so as to cover the entire connection portion 23. Also good.

  If the plug 1A with the connection portion 23 covered with the mica tape 7B is manufactured by the above-described manufacturing method, the adjacent connection portions 23 in the plug body 1z are kept insulated by the mica tape 7B. Thus, tracking due to a short circuit of the connecting portion 23 can be prevented.

Further, the mica tape 7B has a higher heat resistance temperature than the glass cloth tape 7A described above, and even if the mica tape 7B is heated to a temperature higher than the heat resistance temperature of the glass cloth tape 7A due to the heat generated by the plug blade 3 due to overcurrent, the insulating property is maintained. The heat resistance can be improved without being damaged.
As a result, the heat resistance of the connection part 23 to which the lead wire 21 of the cord 2 and the plug blade 3 are connected can be increased, and the insulation between the connection parts 23 can be prevented from being reduced by heat generation.

  Further, in addition to the insulating effect by the glass cloth tape 7A or the mica tape 7B, the insulating effect by the improved vinyl chloride constituting the inner layer portion 6A can be obtained synergistically, so that the insulating material is not insulated by the glass cloth tape 7A or the mica tape 7B. Insulation improves.

(Second Embodiment)
Next, with reference to FIG. 7, the manufacturing method which manufactures the plug 1B of 2nd Embodiment is demonstrated.
FIG. 7 is an explanatory view of a manufacturing method for manufacturing the plug 1B of the second embodiment. FIG. 7 (a) shows the cord 2, the plug blades 3 and 3, and the ground electrode 4 made of improved vinyl chloride in advance. FIG. 7B is a longitudinal side view of the molding process in which the outer layer part 6B of the outer skin 6 is molded with vinyl chloride.
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the manufacturing method of the second embodiment, first, as shown in FIG. 7A, the connecting portion 23 connecting the conductive wire 21 of the cord 2 and the plug blade 3, and the ground wire 22 and the ground electrode 4 are connected. The plug blade 3 to which the conductive wire 21 is connected and the grounding electrode 4 to which the ground wire 22 is connected to the inner layer portion 6A having a core shape that is molded in advance with improved vinyl chloride so that the connection portion 24 is covered. Assemble. Alternatively, the inner layer portion 6A is injection molded so that the connection portions 23 and 24 are covered by the manufacturing method of the first embodiment.

  Thereby, between the connection parts 23 and 23 of the conducting wires 21 and 21 exposed from the front-end | tip part of the code | cord | chord 2 and the plug blades 3 and 3 connected to each of the conducting wires 21 and 21 is made into a predetermined space | interval by the inner layer part 6A. While restricting to the separated state, the distal ends of the plug blades 3 and 3 and the ground electrode 4 are supported in a state of protruding a predetermined length from the front end of the inner layer portion 6A toward the front side.

  Thereafter, the front edge side of the inner layer portion 6A is fitted and integrated with the rear end side of the second core 51 from the rear, and the plug blade 3 is protruded forward from the front end of the inner layer portion 6A. 3 and the ground electrode 4 are inserted into the plug blade insertion holes 52b and 52b and the ground electrode insertion hole 53 of the second core 52, respectively, and the plug blades 3 and 3 and the ground electrode 4 are inserted into the plug blades 3 and 3 and the ground. The tip side of the pole 4 is supported in a state where it protrudes a predetermined length from the front end of the second core 52 toward the front side.

  Next, the cord 2, the blades 3 and 3, the grounding electrode 4, the core 5 and the inner layer portion 6A are integrally assembled and set between an upper die 8b and a lower die 9b described later. Then, the outer layer portion 6B of the outer skin 6 is injection-molded (see FIG. 7B).

  In order to mold the outer layer portion 6B of the outer skin 6, between the connecting portions 23, 23 between the lead wires 21, 21 exposed from the tip of the cord 2 and the plug blades 3, 3 connected to the lead wires 21, 21 respectively. 7 in which the cord 2, the plug blades 3, 3, the grounding electrode 4, and the core 5 are integrally assembled with the inner layer portion 6 </ b> A being regulated at a predetermined interval. As shown in (b), it is placed between an upper mold 8b and a lower mold 9b having cavities of a predetermined shape.

  Thereafter, vinyl chloride (specifically, a thermoplastic resin such as polyvinyl chloride, vinyl chloride polymer, vinyl chloride resin, vinyl chloride homopolymer) is placed in the cavity formed between the upper die 8b and the lower die 9b. To ejaculate.

  That is, the outer layer portion 6B is formed by removing the engaged portion 51c of the first core 51, the outer surface excluding the front end surface on which the plug blade 3 and the grounding electrode 4 of the core 5 are projected, and the rear of the core 5. Injection molding is performed so as to cover the exposed outer surface of the inner layer portion 6A exposed to the rear side from the end and the distal end side outer peripheral surface of the cord 2 exposed to the rear side from the rear end of the inner layer portion 6A.

  After the outer layer portion 6B is injection-molded, the upper die 8b and the lower die 9b are separated, and the plug body 1z with the outer skin 6 being injection-molded is taken out, whereby the manufacture of the plug 1B is completed.

  The plug 1B according to the second embodiment manufactured by the above-described manufacturing method has a predetermined length protruding from the rear end of the second core 52 on the rear end side of the plug blade 3 to which the conducting wire 21 is connected. The connecting portions 23 adjacent to each other in the plug 1B are restricted to a state separated by a predetermined interval by an inner layer portion 6A that is injection-molded so as to cover the connecting portions 23.

  Further, since the glass cloth tape 7A wound so as to cover the connecting portions 23 is insulated, the connecting portions 23 can be reliably insulated, and the connecting portions 23 are kept at an interval at which insulation is obtained. It can be assembled as it is.

  As a result, it is possible to prevent the occurrence of tracking and carbonization inside the insertion plug 1B and to manufacture the insertion plug 1B having excellent tracking resistance, heat resistance, and assembly property. Thereby, there can exist an effect | action and effect substantially equivalent to the said 1st Embodiment.

  Note that the inner layer portion 6A may be injection-molded with an elastomer instead of the above-described improved vinyl chloride. Moreover, you may injection-mold the outer layer part 6B with an elastomer instead of vinyl chloride.

(Third embodiment)
Next, a manufacturing method for manufacturing the insertion plug 1C of the third embodiment will be described with reference to FIG.
FIG. 8 is an explanatory view of a manufacturing method for manufacturing the plug 1C of the third embodiment. FIG. 8 (a) shows the cord 2, the plug blades 3, 3, the grounding electrode 4, and the core 5. FIG. 8B is an explanatory side view of the assembling process, and FIG.
Note that in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In the manufacturing method of the third embodiment, first, as shown in FIG. 8A, after the first core 51 and the second core 52 are fitted, the lead wire 21 of the cord 2 and the plug blade 3 are connected. The plug blades 3 and 3 to which the lead wires 21 and 21 of the cord 2 are connected are inserted into the plug blade insertion holes 52b and 52b of the second core 52 while the connected connection portion 23 is covered with the glass cloth tape 7A.
Further, the ground electrode 4 connected to the ground wire 22 is inserted into the corresponding ground electrode insertion hole 53, and the bases of the plug blades 3, 3 and the ground electrode 4 are connected to the first and second cores 51 of the core 5. , 52.

As a result, the plug blades 3 and 3 and the grounding electrode 4 are supported in a state in which the distal ends of the plug blades 3 and 3 and the grounding electrode 4 protrude from the front end of the second core 52 by a predetermined length. The rear ends of the plug blades 3 and 3 and the grounding electrode 4 are supported so as to protrude a predetermined length from the rear end of the second core 52 toward the rear side.
Further, the connecting portions 23 and 23 between the conducting wires 21 and 21 exposed from the tip end of the cord 2 and the plug blades 3 and 3 connected to the conducting wires 21 and 21 are separated by a core 5 at a predetermined interval. Regulated to the specified state.

  Next, a part in which the cord 2, the blades 3 and 3, the grounding electrode 4 and the core 5 are integrally assembled is placed between the upper mold 8b and the lower mold 9b having a cavity having a predetermined shape. After setting, the outer skin 6 of the plug body 1z is injection-molded (see FIG. 8B).

  After setting as described above, an elastomer (specifically, a thermoplastic resin such as an olefin-based elastomer, a styrene-based elastomer, a urethane-based elastomer, an ester-based elastomer, or a polyamide-based elastomer) is bonded to the upper mold 8b and the lower mold 9b. It injects into the cavity formed between.

That is, the outer skin 6 of the plug main body 1z is removed from the outer surface except for the front end surface where the plug blade 3 and the ground electrode 4 of the core 5 are projected, except for the engaged portion 51c of the first core 51, and the core. 5, a connecting portion 23 connecting the lead wire 21 exposed to the rear side from the rear end of the wire 5 and the plug blade 3, a connecting portion 24 connecting the ground wire 22 and the grounding electrode 4, the lead wire 21 and the ground wire of the cord 2. Injection molding is performed so as to cover the outer peripheral surface on the front end side where 22 is exposed.
After the outer skin 6 is injection-molded, the upper die 8b and the lower die 9b are separated, and the plug body 1z on which the outer skin 6 is injection-molded is taken out, whereby the manufacture of the plug 1C is completed.

  The plug 1 </ b> C of the third embodiment manufactured by the above-described manufacturing method protrudes a predetermined length from the rear end of the second core 52 to the rear end side of the plug blade 3 to which the conducting wire 21 is connected. In the plug plug 1C, the adjacent connection parts 23 are regulated to be separated by a predetermined interval by the outer skin 6 of the plug body 1z formed by injection so as to cover the connection parts 23. Since the glass cloth tape 7A wound so as to cover the portion 23 is insulated, the connection portion 23 can be reliably insulated, and the connection portion 23 is integrally maintained while maintaining an insulating property. Can be assembled.

  As a result, it is possible to prevent the occurrence of tracking and carbonization inside the insertion plug 1C, and it is possible to manufacture the insertion plug 1C having excellent tracking resistance, heat resistance, and moldability. Thereby, there can exist an effect | action and effect substantially equivalent to the said 1st Embodiment.

  Furthermore, since the process of insulating between the connecting portions 23 connecting the conducting wire 21 of the cord 2 and the plug blade 3 and the process of forming the plug body 1z can be performed simultaneously, the manufacturing work for manufacturing the plug 1C can be simplified. The work efficiency can be improved.

Instead of the above-described elastomer, the outer skin 6 of the plug 1C may be injection-molded using, for example, improved vinyl chloride obtained by blending a predetermined amount of an ethylene polymer and calcium carbonate with respect to vinyl chloride. .
Thereby, in addition to the insulating effect by the glass cloth tape 7A or the mica tape 7B, the molding accuracy, dimensional stability, and tracking resistance of the plug 1C can be further improved by the characteristics of the elastomer.

  Further, the outer skin 6 may be injection-molded only with vinyl chloride, and since an insulating effect by the glass cloth tape 7A or the mica tape 7B is obtained, substantially the same operations and effects as the first embodiment can be achieved.

In the correspondence between the configuration of the present invention and the embodiment,
The plug body of the present invention corresponds to the plug body 1z and the outer skin 6,
Similarly,
Tape-like insulators correspond to glass cloth tape 7A and mica tape 7B,
The present invention is not limited to the configuration of the above-described embodiment, but can be applied based on the technical idea shown in the claims, and many embodiments can be obtained.

  The manufacturing method of the present invention is not limited to the straight type plug described above, and may be applied to, for example, an L type plug in which a plug blade is connected to a cord in a direction perpendicular to the longitudinal direction. Can do.

DESCRIPTION OF SYMBOLS 1A, 1B, 1C ... Insert plug 1z ... Plug main body 2 ... Cord 3 ... Plug blade 4 ... Ground electrode 3a, 4a ... Crimp part 5 ... Core 6 ... Outer skin 6A ... Inner layer part 6B ... Outer layer part 7 ... Tape-like insulation Body 7A ... Glass cloth tape 7B ... Mica tape 18 ... Thermistor 21 ... Conducting wire 22 ... Earth wire 23, 24 ... Connection 51 ... First core 52 ... Second core

Claims (7)

A plug blade is connected to each of the plurality of conductors exposed at the tip end of the cord, and insulated so as to cover the tip portion at which the conductor of the cord is exposed and the base of the plurality of plug blades to which the conductor is connected. A method of manufacturing an insertion plug in which a plug body is injection-molded with a thermoplastic resin,
The plug blade to which the lead wire of the cord is connected is inserted into a plug blade insertion hole of a core formed of a thermoplastic resin so that adjacent plug blades are regulated at a predetermined interval. After the front end side of the blade is protruded by a predetermined length from the front end of the core toward the front side, and the rear end side of the plug blade is supported to protrude from the rear end of the core toward the rear side by a predetermined length. ,
Either one of the elastomer and modified vinyl chloride is covered so as to cover the tip end portion where the lead wire of the cord behind the rear end of the core is exposed and the base portion of the plug blade to which the lead wire is connected. Injection molding the inner layer of the plug body with a thermoplastic resin,
The outer surface of the core excluding the front end surface where the plug blade protrudes, the inner layer portion exposed to the rear side from the rear end of the core, and the rear side exposed from the rear end of the inner layer portion. A method for manufacturing an insertion plug in which an outer layer portion of the plug body is injection-molded with any one of an elastomer and a vinyl chloride so as to cover a tip portion of the cord. A plug blade is connected to each of the plurality of conductors exposed at the tip end of the cord, and insulated so as to cover the tip portion at which the conductor of the cord is exposed and the base of the plurality of plug blades to which the conductor is connected. A method of manufacturing an insertion plug in which a plug body is injection-molded with a thermoplastic resin,
The inner layer of the plug body is made of one of an elastomer and a modified vinyl chloride thermoplastic resin so as to cover the tip end portion where the lead wire of the cord is exposed and the base portion of the plug blade to which the lead wire is connected. The part is injection molded,
The plurality of plug blades are restricted to a state spaced by a predetermined interval in the inner layer portion, and the distal end side of the plug blade is supported in a state protruding a predetermined length from the front end of the inner layer portion toward the front side. ,
The plug blade protruding forward from the front end of the inner layer portion is inserted into a plug blade insertion hole of a core molded from a thermoplastic resin, and the distal end side of the plug blade is directed forward from the front end of the core. After assembling in a state in which the rear end side of the plug blade protrudes a predetermined length from the rear end of the core toward the rear side,
The outer surface of the core excluding the front end surface where the plug blade protrudes, the inner layer portion exposed to the rear side from the rear end of the core, and the rear side exposed from the rear end of the inner layer portion. A method for manufacturing an insertion plug, wherein an outer layer portion of the plug body is injection-molded with one of an elastomer and an improved vinyl chloride so as to cover a tip portion of the cord. A plug blade is connected to each of the plurality of conductors exposed at the tip end of the cord, and insulated so as to cover the tip portion at which the conductor of the cord is exposed and the base of the plurality of plug blades to which the conductor is connected. A method of manufacturing an insertion plug in which a plug body is injection-molded with a thermoplastic resin,
The plug blade to which the lead wire of the cord is connected is inserted into a plug blade insertion hole of a core formed of a thermoplastic resin so that adjacent plug blades are regulated at a predetermined interval. After the front end side of the blade is protruded by a predetermined length from the front end of the core toward the front side, and the rear end side of the plug blade is supported to protrude from the rear end of the core toward the rear side by a predetermined length. ,
The outer surface of the core excluding the front end surface from which the plug blade protrudes, the distal end portion where the conductor of the cord on the rear side from the rear end of the core is exposed, and the plug blade to which the conductor is connected A method of manufacturing an insertion plug in which the plug body is injection-molded with a thermoplastic resin of any one of an elastomer and modified vinyl chloride so as to cover the base of the plug. The improved vinyl chloride,
The manufacturing method of the insertion plug as described in any one of Claims 1-3 comprised by mix | blending predetermined amount of ethylene-type polymer and calcium carbonate with respect to the said vinyl chloride. Covering the entire connecting portion of the connecting portion in a range extending from the outer surface on the front side to the crimping portion where the conducting wire of the plug blade is crimped and connected to the outer surface on the rear side rather than the exposed end portion exposing the core wire of the conducting wire. The manufacturing method of the insertion plug as described in any one of Claims 1-4 coat | covered with the tape-shaped insulator suitably wound several times. The method for manufacturing an insertion plug according to claim 5, wherein the tape-like insulator is made of glass cloth tape. The method for manufacturing an insertion plug according to claim 5, wherein the tape-like insulator is made of mica tape.

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