JPH064550Y2 - Connection structure of high voltage cord to ignition coil for spark ignition internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a connection structure between a spark coil internal combustion engine ignition coil and a high tension cord.

[Prior Art] A conventional connection structure of a high pressure cord to an ignition coil for a spark ignition internal combustion engine has a tubular shape as shown in Fig. 4, a screw 210 is formed on the outer circumference, and a tapered surface is formed on the inner circumference of the tip. 220 is formed, and the core wire 110 bundled in a thin wire is connected to the connection terminal 200 of the ignition coil to which the electrode pin 230 is fixed coaxially with the axis.
Is inserted into the outer periphery of the coating of the high-voltage cord 100, and a tapered surface 310 facing the tapered surface 220 of the connection terminal 200 is formed on the inner periphery. The formed nut 300 is screwed onto the screw 210 and is externally fitted to the outer circumference of the coating of the high-voltage cord 100, and the tapered surfaces corresponding to the tapered surface 220 of the connection terminal 200 and the tapered surface 310 of the nut 300 are provided on both outer circumferences. It is the structure which tightens the soft collar 400 which has 410,420.

[Problems to be solved] However, in the conventional connection structure of the high-voltage cord to the ignition coil for the spark ignition internal combustion engine, the strength of disconnection from the connection terminal of the ignition coil for the spark ignition internal combustion engine of the high-voltage cord is weak, and the electrical insulation property is particularly high. If the elastomer is a relatively soft rubber, the pull-out strength will decrease significantly (5 kg for silicone rubber).
(~ 7 kg) has a drawback.

The object of the present invention is to produce a spark-ignited internal combustion engine of a high-pressure cord that can be manufactured without significantly increasing the cost as compared with the conventional one, and that even a high-pressure cord having a soft coating is excellent in pulling out strength from the connection terminal of the ignition coil. It is to provide a connection structure to an engine ignition coil.

[Means for Solving the Problems] To achieve the above object, the present invention has a tubular shape, a screw is formed on the outer circumference, a tapered surface is formed on the inner circumference of the tip, and an electrode pin is coaxially formed on the shaft center. A high-voltage cord formed by coating a core of thin wires with an electrically insulating elastomer is inserted into the fixed connection terminal of the spark ignition internal combustion engine ignition coil. A nut having a tapered surface facing the tapered surface of the connection terminal is screwed into the screw, and the nut is fitted over the outer periphery of the coating of the high-voltage cord, and the tapered surface of the connection terminal and the nut are provided on the outer periphery of both ends. In a structure for connecting a high-pressure cord to an ignition coil for a spark ignition internal combustion engine, which tightens a soft collar having a tapered surface corresponding to the tapered surface of the electrode pin, the outer diameter of the electrode pin is 1.8 mm or more and 2.4 mm or less. , Pitch p is at least 5mm screw portion L of 0.3mm or more 0.5mm or less
The formed structure was adopted.

[Operation and Effect of Invention] Threaded portion L having a pitch p of 0.3 mm or more and 0.5 mm or less on the outer periphery of the electrode pin having an outer diameter d of 1.8 mm or more and 2.4 mm or less
Is formed at least 5 mm. Therefore, the following operational effects are obtained.

The core wire is attached to the threaded portion L and has excellent pull-out strength.

Since the electrode pin is only screwed, the cost does not increase significantly.

The numerical value of the pin outer diameter d is limited because if the d is less than 1.8 mm, the strength of the pin is poor, and if the d exceeds 2.4 mm, it is necessary to rotate and fit the high-voltage cord.

The numerical value of the pitch p is limited because if p is less than 0.3 mm, the attachment of the core wire is weak, and if it exceeds 0.5 mm, the strength of the pin itself decreases.

This is because if the threaded portion L is 5 mm or less, the pull-out strength is almost the same, and if it is less than 5 mm, the effect of improving the pull-out strength is reduced.

[Embodiment] Next, a first embodiment of a connection structure of a high pressure cord to an ignition coil for a spark ignition internal combustion engine according to the present invention is shown in FIGS. 1 and 2.
A description will be given based on the figure.

The connection structure C of the high pressure cord to the ignition coil for a spark ignition internal combustion engine of the present invention comprises a high tension cord 1, a connection terminal 2 of the ignition coil into which the cord 1 is inserted, and a screw cap loosely fitted to the cord 1. 3 and a rubber bush 4 fitted on the cord 1.

The high tension cord 1 is formed by surrounding a silicon rubber 13, which is an electrically insulating elastomer, on a core wire 12 formed by bundling strands 11 of copper wire plated with tin. The rear end of the cord 1 is connected to the distributor.

The connection terminal 2 of the ignition coil is made of phenolic resin and has a tubular shape. The connection terminal 2 has a size such that the cord 1 can be inserted, and a screw 2 is provided on the outer periphery.
1 is provided, and a tapered surface 22 is formed on the inner circumference of the tip. The electrode pin 23 is coaxially fixed to the axis of the connection terminal 2. A high voltage from the secondary high voltage coil of the ignition coil is applied to the electrode pin 23. Here, the pin outer diameter d of the electrode pin 23 is 2.1 mm, and a screw portion L having a pitch p of 0.4 mm is formed on the outer periphery of the electrode pin 23 by 5 mm.

The screw cap 3 is a P. B. It is a nut made of T resin or the like. The screw cap 3 is provided with a tapered surface 31 which is loosely fitted to the outer periphery of the silicone rubber 13 of the high tension cord 1 and faces the tapered surface 22. Further, a screw 32 is cut on the inner circumference of the cap 3 so as to be screwed with the screw 21 of the connection terminal 2, and a knurled eye 33 is formed on the outer circumference so as not to slip when the cap 3 is tightened. Has been done.

The rubber bush 4 is fitted onto the outer circumference of the silicone rubber 13 of the high tension cord 1, and has tapered surfaces 41 and 42 corresponding to the tapered surfaces 22 and 31 on the outer circumferences of both ends. A plastic washer 43 is arranged between the tapered surface 42 and the tapered surface 31. The rubber bush 4 is attached to the screw cap 3 by an outward elastic force.

Next, the manner in which the connection structure C of the high pressure cord covered with the elastomer to the spark ignition internal combustion engine ignition coil is connected will be described with reference to FIG.

The connection structure C of the high-voltage cord to the spark ignition internal combustion engine ignition coil is connected in the following order.

(1) Insert the screw cap 3 into the high tension cord 1.

(2) Insert the cord 1 into the connection terminal 2 without rotating it. At this time, the threaded portion L is the tip portion 1 of the core wire 12.
4 and the tip end portion 15 of the silicone rubber 13 are spread out and fitted, and the pitch p of the threaded portion L entangles the element wire 11 of the core wire 12 with the threaded portion L of the electrode pin 23 to maintain the connection.

(3) Connect the screw cap 3 to the ignition coil connection terminal 2
It shifts to the side, and screw 32 and screw 31 are screwed together. At this time, the pressure contact force from the taper surface 22 and the pressure contact force from the taper surface 31 via the screw cap 3 are transmitted to the rubber bush 4 and the silicon rubber 1 of the high tension cord 1 is transferred.
Hold 3

The connection structure C of the high-voltage cord to the spark ignition internal combustion engine ignition coil has the following actions and effects.

In the structure C for connecting the high-voltage cord, which is connected as described above, to the ignition coil for the spark ignition internal combustion engine, the connection terminal 2 of the ignition coil is fixed and the high tension cord 1 is extended in the tip extension direction 5 of the electrode pin 23. The tensile strength and pull-out strength were measured and found to be 14kg-18kg, which is 5kg-7kg of the conventional
It has a remarkable effect compared with (see Fig. 3).

The present invention includes the following embodiments in addition to the above embodiments.

The screw of the electrode pin 23 may be a taper screw, the screw direction may be either, and the screw thread may have an arbitrary shape.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a first embodiment of a connection structure of a high pressure cord to an ignition coil for a spark ignition internal combustion engine of the present invention, and FIG. 2 is a sectional view showing a state where the connection is established. FIG. 3 is a graph showing the pull-out strength of the high tension cord. FIG. 4 is a partial cross-sectional view of a connection structure of a conventional high pressure cord to an ignition coil for a spark ignition internal combustion engine. In the drawing, 1 ... High tension cord (high pressure cord), 2 ... Ignition coil connection terminal (spark ignition internal combustion engine ignition coil connection terminal), 3 ... Screw cap (nut), 4 ...
Rubber bush (soft color), 13 ... Silicon rubber (electrically insulating elastomer), 21 ... Screw, 22 ... Tapered surface, 23 ... Electrode pin, 31 ... Tapered surface, 41, 42 ... Tapered surface, d ... Pin outer diameter, p ... pitch, L ... screw part, C ...
Connection structure of high voltage cord to ignition coil for spark ignition internal combustion engine

Claims (1)

[Scope of utility model registration request] 1. A connection terminal of an ignition coil for a spark ignition internal combustion engine, which has a cylindrical shape, a screw is formed on the outer circumference, a tapered surface is formed on the inner circumference of the tip, and an electrode pin is coaxially fixed to the shaft center. , A high-voltage cord formed by coating a core of a bundle of thin wires with an electrically insulating elastomer, is loosely fitted to the outer periphery of the coating of the high-voltage cord, and has a taper surface facing the taper surface of the connection terminal on the inner periphery. A nut formed with is screwed onto the screw, and is fitted onto the outer periphery of the coating of the high-voltage cord, and a soft collar having a taper surface corresponding to the taper surface of the connection terminal and the taper surface of the nut is tightened on the outer circumference of both ends. In a structure for connecting a high-voltage cord to an ignition coil for a spark ignition internal combustion engine, a pitch p of 0.3 mm or more and 0.5 mm or less is provided on the outer circumference of the electrode pin having an outer diameter d of 1.8 mm or more and 2.4 mm or less. Screw part L Without even connecting structure to the spark ignition internal combustion engine ignition coil high voltage cord, characterized in that the 5mm formed.