JP3377403B2 - Plug-in plug - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a plug provided at an end of a power cord of an electric device such as an electric appliance or an OA device. The present invention relates to a plug having a double structure in which a core made of a thermosetting resin is embedded on the abutting surface side of a main body. 2. Description of the Related Art In general, an insertion plug used for a power cord of an electric device such as an electric appliance or an OA device includes a pair of blades inserted into a power outlet, and a connecting portion between the pair of blades and the cord. And a plug body made of an insulating material that supports the blade in a predetermined positional relationship. Conventionally, the plug body has a structure in which a resin molded product manufactured in a separate process from the blade is attached to the connection between the blade and the cord, but recently,
Most have a resin mold structure by injection molding or the like. [0003] In addition, as an insertion plug used for a power cord of an electric device that uses relatively high power, a core made of a thermosetting resin is inserted into the plug body in order to increase the strength and heat resistance of a blade holding portion. A structure in which the blade is held by the core, which is embedded by insert molding or the like, is generally used. In this type of insertion plug, as shown in FIG. 8, the outer dimensions (thickness and width) of the blades 103A and 103B are made to enable the blade to be inserted into the blade receiving hole of the power outlet. To the socket 1 of the power outlet 11
The dimensions are slightly smaller than 1A and 11B. Therefore, when the blades 103A, 103B of the insertion plug are inserted into the power outlet 11, a gap C is left between the outer peripheral surfaces of the blades 103A, 103B and the inner peripheral surfaces of the blade receiving holes 11A, 11B. A short circuit due to accumulation of dust or the like in the gap C may cause a so-called tracking fire. When such a gap C is present, when the plug is inserted into the power outlet, the plug is loose and the blades 103A and 103B of the plug are tilted with respect to the power outlet so that the plug blades 103A and 103B are plugged into the outlet. Receiving hole 11 of
A, 11B may be easily pulled out. In such a situation, if the power cord is accidentally caught by a foot, the plug is easily pulled out and power supply to the electric device is interrupted. The problem occurs. In particular, for OA equipment that always requires power supply,
If the power supply is cut off due to such an unexpected situation, a serious problem such as corruption or loss of internal data is caused. In order to solve the above problems, conventionally,
When the sleeve-shaped resin blade cap is inserted into the base of the blade protruding from the plug body and the blade is inserted into the blade receiving hole of the outlet, the gap between the outer peripheral surface of the blade and the inner peripheral surface of the blade receiving hole Plug having a structure in which the plug is closed by a blade cap (for example, Japanese Patent Laid-Open No. 8-236)
189). In the case where such a blade cap is provided on a plug having a double structure, a method of integrally molding the blade cap with a core made of a thermosetting resin has conventionally been adopted. However, since the thermosetting resin is a hard and brittle material, if the blade cap is a thermosetting resin molded article integrally formed with the core, the blade cap is May be easily damaged when some external force is applied. The present invention has been made in view of such circumstances, and is a double-structure plug having a thermosetting resin core, and has an inner peripheral surface between an outer peripheral surface of a blade and a blade receiving hole of an outlet. An object of the present invention is to provide a plug having a structure in which a blade cap is provided for closing an empty space between the plug and the blade cap, and the blade cap is hardly damaged. [0010] In order to achieve the above object, a plug of the present invention is inserted into blade receiving holes 11A and 11B of an outlet 11 as illustrated in FIGS. Blades 3A and 3B, and a plug body 2 made of an insulating material for protecting a connection portion J between the blades 3A and 3B and the cord 4.
A core 6 made of a thermosetting resin for holding the blades 3A and 3B at predetermined positions is embedded in the plug body 2 so that the front surface 60 forms a part of the abutting surface 20 of the plug body 2. Blade 3 protruding from the core 6
Connect the blades 3A, 3B to the outlet 1
With the blade 3 inserted into the blade receiving holes 11A and 11B, the blade 3
A member for closing a gap formed between the outer peripheral surfaces of A and 3B and the inner peripheral surfaces of the blade receiving holes 11A and 11B. A sleeve-like blade cap 5 made of an insulating material separate from the core 6 is fitted. The rear end of the blade cap 5 is located inside the core 6, and a flange 50 for preventing the blade cap 5 from coming off from the core 6 is integrally formed at the rear end. 3A and 3B have positioning step portions 31 for defining the position of the blade cap 5 with respect to the blade tip.
A, 31B, and a step 62 provided inside the core 6
A and 62B are characterized by the provision of locking step portions 32A and 32B for defining the amount of protrusion of the blades 3A and 3B from the front surface of the core. According to the plug of the present invention having the above structure, the blades 3A, 3B are connected to the blade receiving holes 11A, 1
1B, the blade cap 5 provided at the root of the blades 3A, 3B is inserted into the gap C between the outer peripheral surfaces of the blades 3A, 3B and the inner peripheral surfaces of the blade receiving holes 11A, 11B (see FIG. 8). Since the gap C is closed by being fitted, dust and the like can be prevented from being deposited on this portion. In addition, since the blades 3A and 3B of the insertion plug are securely fixed to the outlet 11 by the fitting of the blade cap 5, rattling of the insertion plug can be prevented. Moreover, in the plug of the present invention, since the blade cap 5 is a separate component from the core (made of thermosetting resin), the blade cap 5 is hardly damaged, for example, PS (polystyrene). And the like. Further, since the blade cap 5 is prevented from coming off from the core 6 by the flange 50 integrally formed at the rear end thereof, the blade cap is not displaced or slipped off, and the safety is further improved. Can be enhanced. In the insertion plug of the present invention, as shown in FIGS. 3 to 5, step portions 62A, 62A,
At 62B, the amount of protrusion of each of the blades 3A and 3B from the core front surface 60, that is, the abutting surface 20 of the plug body 2 is defined.
The locking step portions 32A and 32B are provided, and the plug blades 3A and 3B are provided with positioning step portions 31A and 31B for defining the position of the blade cap 5 with respect to the blade tip. Blade cap 5 to 3B
, That is, the position of the blade cap 5 with respect to the blade tip can be made constant, so that the protrusion amount (height) of the blade cap 5 with respect to the abutment surface 20 of the plug body 2 in the finished product can be always made constant. . Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a horizontal sectional view showing the structure of the embodiment of the present invention, and FIG. 2 is an external perspective view of the embodiment.
FIG. 3 is a horizontal sectional view showing a main structure of the embodiment of the present invention, and FIG. 4 is a sectional view taken along line XX of FIG. First, the plug 1 of this embodiment mainly comprises a plug body 2, a pair of blades 3A and 3B, and a core 6. The pair of blades 3A and 3B are connected to the power outlet 1
A metal plate inserted into one of the blade receiving holes 11A and 11B is connected to a connection terminal T (see FIG. 5) provided at each rear end thereof.
The core wire of the power cord 4 is connected by caulking (crimping). Connection J between each blade 3A, 3B and power cord 4
Is a plug body 2 injection-molded by a method described later.
Protected by A core 6 is embedded in the abutment surface 20 side of the plug body 2, and the core 6
A pair of blades 3A and 3B are supported and fixed. The core 6 is a molded product of a thermosetting resin, is insert-molded into the plug body 2 by a method described later, and its front surface 60 is formed so as to form a part of the abutting surface 20 of the plug body 2. ing. As shown in FIGS. 3 and 4, the core 6 has
The blade insertion holes 61A and 61B are provided in a positional relationship corresponding to the blade receiving holes 11A and 11B of the power outlet 11 shown in FIG. Each of the blade insertion holes 61A and 61B has such a shape and size that a blade cap 5 described later can be inserted. In the core 6, each insertion hole 61A,
Positioning steps 62A and 62B are provided for respectively defining the positions of the blades 3A and 3B inserted into 61B. In this embodiment, blade caps 5 are attached to the roots of the blades 3A and 3B protruding from the plug body 2, respectively. The blade cap 5 is a resin molded product obtained by molding a resin such as PS (polystyrene) into a sleeve shape. As shown in FIG. 6, a flange 50 is integrally formed at one end. The thickness of the sleeve portion of the blade cap 5 is determined in such a manner that the blades 3A and 3B of the plug are inserted into the blade receiving holes 11A and 11B of the power outlet 11 and the respective blades 3A and 3B.
It is machined to the same size as or slightly smaller than the gap C (see FIG. 8) provided between the outer peripheral surfaces of A and 3B and the inner peripheral surfaces of the blade receiving holes 11A and 11B. Further, a blade receiving hole 11 of a power outlet 11 is provided at a tip end of the blade cap 5.
A, 30 ° in consideration of the insertability at the time of insertion into 11B
It is chamfered to a certain degree. As shown in FIGS. 3 and 4, the blades 3A and 3B are brought into contact with the rear end surfaces 51 of the blade caps 5 inserted into the blades 3A and 3B, respectively.
Positioning step 31A defining the position of the blade relative to the blade tip,
31B are provided. Further, the blades 3A and 3B are provided with locking step portions 32A and 32B which contact the positioning step portions 62A and 62B provided on the respective cores 6 and define the amount of protrusion from the respective core front surfaces 60. The locking step 32
With the blades 3A and 3B positioned with respect to the core 6 by A and 32B, as shown in FIG. 3, the blade cap 5 projects outside through the blade insertion holes 61A and 61B. The rear end face 51 of the blade 5 contacts the positioning steps 31A, 31B of the blades 3A, 3B, so that the movement of the cap 5 toward the blade rear end is restricted, and
The flange 50 has a rear end surface 63 of the blade insertion holes 61A and 61B.
A, 63B, the movement to the blade tip side is regulated. Next, the operation of the present embodiment will be described together with the manufacturing method. First, the sheath at the end of the power cord 4 is peeled off, and the core wire is crimped to the connection terminal T of the blades 3A, 3B of the plug to connect the blades 3A, 3B to the power cord 4.
A blade cap 5 is attached to each blade 3A, 3B at the rear end face 5 thereof.
1 is inserted up to the position where it contacts the positioning step portions 31A, 31B of the blades 3A, 3B. Next, the blades 3A, 3B are respectively inserted into the blade insertion holes 61A, 61B of the core 6, and the locking step portions 32A, 32B of the respective blades 3A, 3B are fitted with the positioning step portions 62 of the core 6.
A and 62B. With the blades 3A and 3B incorporated as described above (the state shown in FIGS. 3 and 4), the core 6 is used to mold the plug body 2 into an injection mold (not shown). Place in the cavity. At this time, the front 60 of the core 6
Is applied to a portion of the mold cavity where the abutment surface 20 of the plug body 2 is formed, and a fixing pin P is passed through a hole h at the tip of each of the blades 3A and 3B (see FIG. 3).
The positioning of B with respect to the mold is performed. Then, a molten resin (polyvinyl chloride) is injected into the mold cavity, and the connection portion J between each blade 3A, 3B and the power cord 4 and the core 6 are insert-molded into the plug body 2. By doing so, the plug 1 having the structure shown in FIG. 1, that is, the connection portion J between the blades 3A and 3B and the power cord 4 is protected by the plug body 2 and the blades 3A and
The insertion plug 1 having a structure in which the core 6 incorporating the 3B is embedded in the plug body 2 is obtained. As described above, in the present embodiment, when the cap body 2 is subjected to injection molding, the positioning of the blade cap 5 to the blades 3A, 3B is performed by the positioning steps 31A, 31B provided on the blades 3A, 3B. Since the insertion amount, that is, the position of the blade cap 5 with respect to the blade tip can be accurately positioned, the protrusion amount (height) of the blade cap 5 with respect to the abutment surface 20 of the plug body 2 in the finished product can be always constant. . Further, in the finished product, the blade cap 5 has a flange 50 at its rear end formed with the blade insertion hole 6 of the core 6.
By hitting the end faces 63A, 63B of the cores 1A, 61B, the core cap 6 is prevented from coming off, so that the blade cap 5 is separated from the front face 60 of the core 6, that is, the abutting face 20 of the plug body 2, and the blade 3, It will not fall out of 3B. In the above embodiment, the pair of blades 3
An example in which the present invention is applied to a two-pole insertion plug having A and 3B has been described. However, the present invention is not limited to this, and can be applied to a connector having three poles or any other number of poles. It is. As described above, according to the present invention,
2 with core of thermosetting resin product embedded in plug body
In the heavy-duty plug, the blade cap is fitted to the base of the blade protruding from the core, so when the plug blade is inserted into the socket receiving hole of the outlet, the outer peripheral surface of the blade and the blade receiving hole Gaps between the inner peripheral surface and the inner peripheral surface can be closed. As a result, it is possible to prevent a short circuit, a tracking fire, and the like caused by accumulation of dust and the like on the blade of the plug. In addition, the blade cap is made of a hard-to-break material (eg, PS) separately from the thermosetting resin core.
Etc.), there is no possibility that the blade cap is damaged. Further, since the blade cap is integrally formed with a flange for preventing the core from coming off, there is no problem that the blade cap separates from the abutting surface of the plug body or falls off the blade.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a horizontal sectional view showing a structure of an embodiment of the present invention. FIG. 2 is an external perspective view of the embodiment. FIG. 3 is a main structure of an embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line XX of FIG. 3. FIG. 5 is a side view showing a structure of a blade used in the embodiment of the present invention. FIG. 6 is a blade cap used in the embodiment of the present invention. 7 is a perspective view showing the structure of the present invention. FIG. 7 is a view showing a use state of the embodiment of the present invention. FIG. 8 is a view showing an example of a use state of a conventional plug. Main body 20 Abutment surfaces 3A, 3B Blades 31A, 31B Positioning step 32A, 32B Locking step 4 Power cord 5 Blade cap 50 Flange 51 Rear end face 6 Core 60 Front 61A, 61B Blade insertion holes 62A, 62B Positioning step 11 Power outlets 11A, 11B Blade support

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01R 13/44 H01R 13/502 H01R 13/52

Claims (1)

(57) [Claims] [Claim 1] A plug used for a power cord or the like of an electric device, the blade being inserted into a blade receiving hole of an outlet,
A plug body for protecting the connection between the blade and the cord is provided.A core made of a thermosetting resin for holding the blade in a predetermined position is provided in the plug body. In the insertion plug which is embedded so as to form a part, the outer peripheral surface of the blade and the blade receiving hole are inserted at the base of the blade protruding from the core in a state where the blade is inserted into the blade receiving hole of the outlet. A member for closing the gap between the inner peripheral surface and the core.A sleeve-like blade cap made of an insulating material separate from the core is fitted.The rear end of this blade cap is inserted into the core. And a flange for preventing the blade cap from coming off from the core at the rear end is integrally formed, and the blade has a positioning step portion for defining a position of the blade cap with respect to the blade tip, Set inside the core An insertion plug, wherein a locking step is provided for defining the amount of protrusion of the blade from the front surface of the core in contact with the stepped portion.