JP2010135089A - Power plug, and manufacturing method of power plug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power plug capable of integrally forming a sleeve with an inner ring, and preventing itself from coming off, as well as a manufacturing method of the power plug. <P>SOLUTION: The power plug is provided with blades, a bridge integrally formed with a sleeve covering a root part of the blade and an inner ring retaining a lower end of the blade, and a plug body molded to have a bridge except an upper part of the sleeve incorporated. In the manufacturing method of the power plug, a bridge is formed by integrally molding the sleeve for covering the root part of the blade and the inner ring for retaining the lower end of the blade with hard resin, the lowest end of the blade is press-connected to a wire conductor of a cord with the use of caulking, then, the upper part of the sleeve is removed, and the plug body is molded by soft resin so as to incorporate the cord parts of bridging, caulking and press-connection. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a power plug and a method for manufacturing the power plug, and more particularly, to a power plug having tracking resistance and a method for manufacturing the power plug.

A conventional power plug having tracking resistance is described in Japanese Patent No. 3327093. In the power plug of this publication, a connection terminal member (blade) is inserted into a thermosetting resin, and the proximal end side of the connection terminal member is connected to a power cord by a crimping portion. The plug body is made of a polyvinyl chloride material or the like. A gap filling portion (sleeve) is provided to cover the base of the connection terminal member. When the resin such as a polyvinyl chloride material forming the plug body is poured into the mold, the gap filling portion is made of a thermosetting resin. It is formed simultaneously with the plug body through the connection terminal insertion hole.
Japanese Patent No. 3327093

  In the power plug of the conventional example, the surface of the thermosetting resin is exposed on the front surface of the plug body, and therefore, the thermosetting resin is easily pulled out of the plug body. In order to prevent this disconnection, the thermosetting resin has to be provided with relatively long legs extending into the plug body. In addition, the gap filling part is formed by pouring a resin such as polyvinyl chloride material into the mold and through the connection terminal insertion hole of the thermosetting resin, but this process is to form a thin wall thickness of the gap filling part. It is very difficult to realize at the same time as the complete formation of the plug body.

  Accordingly, an object of the present invention is to provide a power plug in which a sleeve can be formed integrally with a core and can be prevented from coming off.

  Another object of the present invention is to provide a method of manufacturing a power plug that can integrally form a sleeve with a core and prevent the sleeve from coming off.

  The power plug according to the present invention includes a bridge in which a blade, a sleeve that covers a base portion of the blade, and a core that holds the lower end of the blade are integrally formed, and the bridge is built in except for the upper portion of the sleeve. And a plug body molded into the shape.

  In the method for manufacturing a power plug according to the present invention, a sleeve is formed by integrally molding a sleeve that covers the base portion of the blade and a core that holds the lower end of the blade with a hard resin, and the lower end of the blade is caulked. The plug main body is molded with a soft resin so as to incorporate the cords of the bridge, caulking, and crimping connection portions except for the upper portion of the sleeve.

  According to the present invention, a power plug can be obtained in which the sleeve can be formed integrally with the core and can be prevented from coming off. In addition, a method for manufacturing a power plug can be obtained in which the sleeve can be formed integrally with the core and can be prevented from coming off.

  The power plug of the present invention is formed so that the blade, the bridge that covers the base portion of the blade and the core that holds the lower end of the blade are integrally molded, and the bridge is built in except for the upper portion of the sleeve. A plug body.

  In the power plug manufacturing method of the present invention, a sleeve is formed by integrally molding a sleeve that covers the base portion of the blade and a core that holds the lower end of the blade with a hard resin, and then the lowermost end of the blade is formed. The crimping body is crimped and connected to the electric wire conductor of the cord, and then the plug body is molded with a soft resin so that the cord of the bridge, caulking, and crimping connection portion is built in except for the upper portion of the sleeve.

  1 is a diagram showing a power plug according to a first embodiment of the present invention, FIG. 1a is a plan view showing an internal bridge, FIG. 1b is a sectional view thereof, and FIG. 1c is a sectional view thereof. It is. In FIG. 1, blades (blade: connection terminals) 12 are covered with a sleeve (covering resin) 16 b whose base portion is injection-molded with a hard thermoplastic resin that provides tracking resistance. These sleeves 16b are molded integrally with a core 16a that holds the lower end of the blade 12 and also holds the lower end of the ground pin 14. For convenience of explanation, the integrally formed sleeve 16b and the core 16a are referred to as a bridge 16.

  A caulking 18 is provided at the lowermost end of the blade 12 and the lowermost end of the ground pin, and the caulking 18 is crimped and connected to the electric wire conductor of the cord 20. The plug body 22 is formed by injection molding using a soft resin such as soft polyvinyl chloride, a soft polyethylene resin, a soft polyolefin resin, etc., except for the upper portion of the sleeve 16b. 18 and injection-molded so that the cord 20 is incorporated. Since the bridge 16 is built in the plug body 22, it does not come out of the plug body 22. Further, since the sleeve 16b is molded without passing through the connection terminal insertion hole of the thermosetting resin, the sleeve 16b is surely molded without being incomplete.

  FIG. 2 is a perspective view showing a power plug according to a second embodiment of the present invention, and shows the plug body in a transparent manner so that the internal structure can be easily understood. The second embodiment is directed to a two-pole power plug that is not provided with a ground pin. Since the portion excluding the ground pin is the same as that of the first embodiment, detailed description thereof is omitted.

  In the manufacture of the power plug of the first embodiment, the two blades 12 and the ground pin 14 are arranged in a mold, and a hard resin is injected to integrally mold the core 16a and the blade 16b. That is, the bridge 16 is formed. Thereafter, the lowermost end of the blade 12 and the lowermost end of the ground pin 14 are crimped and connected to the wire conductor of the cord 20 by caulking 18. Next, the integrated body is placed in a mold, soft resin is injected, and the plug body 22 is formed so as to incorporate the bridge 16, the caulking 18, and the cord 20 except for the upper portion of the sleeve 16b. .

  Since the power plug according to the second embodiment is manufactured in the same manner as the first embodiment except for the ground pin, detailed description thereof is omitted.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the power plug of Example 1 of this invention, FIG. 1a is the top view which also shows an internal bridge | bridging, FIG. 1b is the sectional drawing, FIG. 1c is the sectional drawing. It is a perspective view which shows the power plug of Example 2 of this invention, and permeate | transmits and shows a plug main body so that an internal structure can be understood easily.

Explanation of symbols

10 Power plug 12 Blade (blade: connection terminal)
14 Earthpin 16 Bridge 16a Core 16b Sleeve 18 Caulking 20 Cord 22 Plug body

Claims (4)

A blade,
A bridge formed by integrally molding a sleeve covering the base portion of the blade and a core holding the lower end of the blade;
A plug body molded to incorporate the bridge except for the upper portion of the sleeve;
A power plug characterized by comprising:   2. The power plug according to claim 1, wherein the bridge further holds a ground pin. A bridge is formed by integrally molding the sleeve that covers the base of the blade and the core that holds the lower end of the blade with a hard resin,
Crimp the lower end of the blade to the cable conductor using caulking,
Except for the upper part of the sleeve, the plug body is molded with a soft resin so as to incorporate the cord of the bridge, caulking, and crimp connection part.
A method for manufacturing a power plug.   4. The method for manufacturing a power plug according to claim 3, wherein the bridge also holds a ground pin.