JP2001244041A - Connecting structure of plug gap and plug cord - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connecting structure which conveniently and cheaply performs connection with the plug, even if it is a resistor plug cord. SOLUTION: The plug gap 10 comprising an L-shaped rubber body has an insertion mouth 1a for detachably fitting a plug into an insulator head of an ignition plug in one external cylinder section 1, a cord insertion mouth 2a for fitting a plug cord 20 extended from the secondary side of the ignition coil in the other external cylinder section 2. Connection metal fitting 3 connected with a terminal of the ignition plug in the inner part of the plug insertion mouth 1a of the plug cap, a terminal 4 provided with a external thread 4a on its periphery in the inner part of cord insertion mouth 2a, and a cylindrical resistor 5 connected between the terminal 4 and the connection metal fitting 3 to supperss the noise when it is necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure between a plug cap and a plug cord used in an internal combustion engine.

[0002]

2. Description of the Related Art In order to supply a high voltage for ignition from an ignition coil to an ignition plug mounted on a cylinder head, usually a plug cap and an ignition coil are detachably mounted on an insulator head of the ignition plug. The plug cord extended from the next side is used.

Conventionally, these interconnections are made by screwing a terminal pin with a male screw provided in a plug cap into a core material of a plug cord covered with an insulating resin (for example, Japanese Patent Application Laid-Open No. 6-84580). No.).

[0004] In such a connection method, when the core material is a stranded wire composed of a large number of thin metal wires, the stranded wires can be entangled with each other around the external thread by screwing in the terminal pins, so that the connection is performed with relatively high tensile strength. can do.

[0005]

By the way, general-purpose engines, especially engines used in personal watercrafts, are:
Compared with automobiles, the radio noise level is very high, so the resistor is built into the plug cap as seen in the prior art, but sometimes the regulation value could not be satisfied .

Therefore, it has been considered to use a plug cord with resistance wound around a resistance wire having a predetermined resistance value. Such a plug cord, as shown in FIG. A ferrite-containing resin layer 6b is formed on the outer periphery, and a resistance wire 6c is sequentially wound thereon, and then a jacket layer 6d is formed. Because of no entanglement with the stranded wire, a predetermined connection structure could not be obtained.

It is also conceivable to adopt a method of applying an adhesive to the connection between the terminal pin and the plug cord with resistance. However, the use of the adhesive not only increases the number of extra steps but also strictly controls the adhesive. In addition, it is not a method that is electrically reliable, because it causes problems such as the need for manufacturing cost, and is easily exposed because of exposure to severe conditions.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a connection structure that can easily and inexpensively connect a plug cap even with a plug cord with a resistor. .

[Means for solving the problem and functions and effects]

In order to achieve the above object, according to the present invention, a terminal pin having an external thread engraved on an outer periphery thereof is provided in a plug cap, and the terminal pin is fixed to an end of the plug cord. A locking piece having a hole is formed in a crimp fitting electrically connected to the terminal, and the hole of the locking piece of the crimp fitting is screwed into a male screw of the terminal pin.

According to the present invention, since the plug cap is left as it is and the crimping fitting is simply fixed to the plug cord, the process is simpler than when an adhesive is used, and the process is omitted. Therefore, the manufacturing cost can be reduced. Moreover, since the connection between the plug cap and the plug cord is a screw connection between the terminal pin and the locking piece, the connection can be made firmly, and it does not drop out even if subjected to any severe environment. The reliability is also good. A typical technique for fixing the crimping fitting to the plug cord includes caulking, but is not limited thereto.

According to the second aspect of the present invention, the locking piece can be formed simultaneously with the formation of the crimping fitting, so that the manufacturing cost can be further reduced.

Further, according to the third and fourth aspects of the present invention, a connection structure having a resistor and / or a resistance wire for suppressing noise can be provided, so that it can be applied to a general-purpose engine, especially a personal watercraft or the like in which noise suppression (regulation) is strict. It is very effective for the general-purpose engine used.

According to the fourth aspect of the present invention, the terminal pins of the plug cap can be connected without being screwed into the plug cord. Enable connection.

[0014]

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

FIG. 1 shows an internal structure of a connection portion between a plug cap 10 and a plug cord 20 according to an embodiment of the present invention. The plug cap 10 is made of an L-shaped rubber body,
A plug insertion port 1a which is detachably fitted to an insulator head of a spark plug (not shown) is provided in one outer cylinder portion 1 and a secondary coil 2 (not shown) is provided in the other outer cylinder portion 2. Each has a cord insertion port 2a through which a plug cord 20 extending from the side is inserted.

A connection fitting 3 for connecting to a terminal of the ignition plug is disposed in a deep portion of the plug insertion port 1a of the plug cap 10, and a terminal in which a male screw 4a is engraved on the outer periphery of a deep portion of the cord insertion port 2a. A pin 4 is provided, and a bar-shaped resistor 5 is connected between the terminal pin 4 and the connection fitting 3 as necessary, thereby providing a noise suppressing function.

As shown in FIG. 4, the plug cord 20 has a glass layer 6a as a reinforcing material, a ferrite-containing resin layer 6b formed on the outer periphery thereof, and a resistance wire 6c wound thereon to provide a noise suppressing function. , And further protected by an insulating layer 6e, a fabric layer 6f, and a jacket layer 6d. These plug caps with resistance and plug cords with resistance wires are the same as those of the conventional configuration.

Next, the main part of the present invention will be described with reference to FIG. FIG. 2 shows a crimp fitting 7 used in the present invention,
U-shaped fixing parts 7a, 7a and a circular pipe part 7b are formed in series by pressing from a thin metal plate such as brass,
Saw teeth 7c, 7c are formed on both side edges of the fixed portion 7a, and a part of the lower surface of the circular tube portion 7b is cut and raised to bend toward the inside of the circular tube portion 7b, thereby forming a locking piece 7d. At the same time, a through hole 7e is formed in the locking piece 7d.

The inner diameter of the circular tube portion 7b is set to a size for loosely inserting the terminal pin 4 of the plug cap, and the inner diameter of the through hole 7e of the locking piece is set to the size of the terminal pin 4 of the plug cap.
Is set to a size that can be screwed into the male screw 4a.

FIG. 5 shows a state in which the crimp fitting 7 is fixed to the end of the plug cord 20. U-shaped fixing portion 7 via bridge fitting 8 connected to resistance wire 6c of the plug cord
The outer periphery of one end of the cord is inserted into the cords a and 7a, and both side edges are bent inward by a predetermined caulking tool so that the saw teeth 7c and 7c bite into the jacket layer 6d of the cord and are joined (fixed).

When the plug cord 20 to which the crimp fitting 7 is fixed at the end is inserted from the cord insertion opening 1a of the plug cap 10, the tip of the terminal pin 4 is
b is inserted into the through hole 7e of the locking piece while being inserted.

When the cord is rotated in a predetermined direction in this state, the through hole 7e is screwed and connected along the external thread 4a on the outer periphery of the terminal pin 4. Since the connection in this case is a screw connection, a strong connection can be obtained, and thereby a highly reliable electrical connection can be obtained.

Therefore, the ignition plug and the plug cord are electrically connected, and the ignition high voltage generated in the ignition coil is supplied to the ignition plug.

When it is necessary to replace the plug cord or the plug cap, if the cord is turned in the opposite direction to the screwing of the terminal pin 4, the through-hole 7e is inserted into the terminal pin 4. Since the two can be easily separated from the male screw 4a and separated from each other, the replacement operation can be easily performed.

FIG. 3 shows another embodiment of the crimp fitting 7 'used in the present invention. U-shaped fixing portions 7a, 7a which are caulked and fixed to the outer periphery of the end of the plug cord 20;
Through holes 7 e ′, 7 screwed with the male screw 4 a of the terminal pin 4 of FIG.
e 'and a double-folded locking piece 7d'.

In this embodiment as well, a strong connection structure can be obtained as in the embodiment of FIG.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a connection structure according to the present invention.

FIG. 2A is a top view of a crimping fitting used in the present invention,
(B) Side view, (c) bottom view, (d) front view.

FIG. 3 is a sectional view of another embodiment of the present invention.

FIG. 4 is a perspective view showing a plug cord.

FIG. 5 is a perspective view showing a state where a crimping fitting is connected to a plug cord.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Plug cap 20 Plug cord 1 and 2 Outer cylinder part 2a Cord insertion opening 1a Plug insertion opening 3 Connection fitting 4a Male screw 4 Terminal 5 Rod resistance 6a Glass fiber 6b Ferrite-containing resin layer 6c Resistance wire 6d Outer layer 6e Insulation layer 6f knitting Deposit 7, 7 'Crimp fitting 7a Fixing part 7b Circular tube part 7c Saw part 7d, 7d' Locking part 7e, 7e 'Through hole 8 Bridge fitting

Claims (4)

[Claims] In a connection structure of a plug cap detachably fitted to an insulator head of an ignition plug and a plug cord extending from a secondary side of an ignition coil, an outer periphery is provided inside the plug cap. A terminal pin engraved with a male screw is provided, and a locking piece having a hole is formed in a crimp fitting fixed to an end of the plug cord and electrically connected to the plug cord. A connection structure between a plug cap and a plug cord, wherein a hole of a locking piece of a metal fitting is screwed into a male screw of the terminal pin. 2. The connection structure according to claim 1, wherein the locking piece is formed by cutting and raising a part of the crimping fitting. 3. The connection structure between a plug cap and a plug cord according to claim 1, wherein said plug cap includes a built-in resistor for suppressing noise. 4. The connection structure between a plug cap and a plug cord according to claim 1, wherein a resistance wire for suppressing noise is wound around the plug cord.