JP2718237B2 - Ignition coil for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition coil directly connected to an ignition plug of each cylinder of an internal combustion engine, and in particular, to a coil body that generates a high voltage, and a high voltage And a connection structure for connecting to a connector portion for conducting electricity to a spark plug.

[Conventional technology]

Conventionally, in an internal combustion engine ignition coil in which a coil part main body that generates a high voltage and a connector part that supplies a high voltage from the coil part body to the ignition coil can be separated, the conductor of the connector part is the same as the coil part body. When attaching to and detaching from the connector, there is one that connects and separates at the center of the connector (for example, Japanese Utility Model Application Laid-Open No. 64-8580).

[Problems to be solved by the invention]

However, in the internal combustion engine ignition coil described above,
The conductors of the connector part are separated at the center of the connector part to absorb the misalignment between the coil part body and the ignition plug, and these conductors are connected by the repulsive force of the spring, There is a problem in that the two conductors separated by wear due to vibration cause poor contact and cannot supply a high voltage to the spark plug. SUMMARY OF THE INVENTION It is an object of the present invention to eliminate a contact failure in a separation unit and to reliably supply a high voltage from a coil unit main body to an ignition plug.

[Means for solving the problem]

Accordingly, the present invention provides a means for solving the above-mentioned problems, a coil part including a primary winding and a secondary winding, a resin case for housing the coil part, and a copper forming an end of the secondary winding. A secondary terminal for connecting a wire, a high-pressure tower having a cylindrical shape integrally formed with the resin case and the resin and having a convex portion on the outer periphery of the cylinder; A coil portion main body including a cylindrical high voltage terminal connected to the next terminal and having a spherical concave portion on the inner periphery; a cylindrical insulating resin body made of an elastic material having a concave portion on the inner end portion; Including a cylindrical conductor fitted in the resin body, a protrusion provided on the outer periphery of one end of the conductor, and a coil spring housed in the other end of the conductor and connected to the ignition plug And a connector section. The coil portion main body is assembled by fitting the convex portion of the high-voltage tower and the concave portion of the insulating resin body, and the projection of the ring spring and the spherical concave portion of the high-voltage terminal can swing. An ignition coil for an internal combustion engine, wherein the ignition coil is fitted.

[Action]

As a result, the high-voltage tower convex portion of the coil portion main body is fitted into the insulating resin body concave portion of the connector portion, and at the same time, the protrusion provided on the conductor is fitted into the spherical concave portion of the high-voltage terminal, and the coil portion main body is formed. The connector and the connector are electrically connected in a swingable state.

〔Example〕

 The present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a main part of an ignition coil for an internal combustion engine according to the present invention. Reference numeral 1 denotes a coil portion including a primary winding and a secondary winding, and 2 denotes a resin case for housing the coil portion 1 in a horizontal position.
A cylindrical high-pressure tower 5 is integrally formed of a resin material at a lower portion thereof, and a cap-shaped high-voltage terminal is fixed inside the high-pressure tower 5 by integral molding. The high-voltage terminal 4 is connected to the secondary terminal 3 to which a copper wire forming an end of the secondary winding is connected. Reference numeral 6 denotes a cylindrical insulating resin body made of an elastic material such as rubber, and a cylindrical conductor 7 is closely fitted to the inner periphery thereof. The conductor 7 has a ring spring 8 made of a conductive metal material connected to the high voltage terminal 4 at an upper end thereof, and a coil spring 9 directly connected to a spark plug (not shown) accommodated at the lower end. A space for fitting the high-pressure tower 5 is formed in a portion of the upper end inner peripheral surface of the insulating resin body 6 facing the ring spring 8.

FIG. 2 is an enlarged view showing a connection portion between the high voltage terminal 4 and the ring spring 8 in the ignition coil.

Reference numeral 6a denotes a ring-shaped recess provided in the inner peripheral portion of the upper end of the cylindrical insulating resin body 6, and the axial section of the recess 6a in the insulating resin body 6 is trapezoidal as shown in FIG. Reference numeral 5a denotes a ring-shaped projection integrally formed with the high-pressure tower 5 on the outer periphery of the upper end of the high-pressure tower 5. The cross section of this convex part 5a is concave part 6a.
The protrusion 5a and the recess 6a are closely fitted to each other. The high-voltage terminal 4 includes a cap portion 4c and a rod-shaped protrusion 4b extending from the upper end of the cap portion 4c. The protrusion 4b is a hole formed in the center of the secondary terminal 3.
3b, and is electrically connected to a projection 3a provided on a peripheral edge of the hole 3b. Reference numeral 4a denotes a ring-shaped recess formed in a spherical shape on the inner periphery of the center of the cap 4c. The concave portion 4a is swingably fitted with a plurality of metal hemispherical protrusions 8a formed on the outer periphery of the ring spring 8 and electrically connected between the high voltage terminal 4 and the ring spring 7. doing.

FIG. 3 is a sectional view of the insulating resin body 6, and FIG. 4 is an exploded view showing a state before the ring spring 8 and the coil spring 9 are assembled to the conductor 7. FIG. 5 is a view after the ring spring 8 and the spring 9 have been assembled to the conductor 7. A plurality of through-holes 7a are provided on the circumference of the upper end of the cylindrical conductor 7, and a ring spring 8 press-fit into the hole 7a through an opening 7c at the upper end of the conductor 7.
The projection 8a is fitted, and the projection 8a projects outside the conductor 7 through the hole 7a. Reference numeral 7b denotes a cap-shaped storage portion integrally formed with the conductor 7 for storing the spring 9. Reference numeral 7d denotes a projection protruded on the inner periphery for preventing the coil spring 9 from falling off. Reference numeral 6b denotes a cylindrical hollow portion formed in the insulator 6 for closely fitting and storing the conductor 7. Reference numeral 6c denotes an upper end portion of the hollow portion 6b, which is a storage portion for storing the high-pressure tower 5.

FIG. 6 is a view showing a state before the connector section is assembled to the coil section main body. A is a coil section main body including a coil section 1 for generating a high voltage, a high-voltage terminal 4 for supplying the high voltage, and the like. And B, a connector portion that is assembled to the coil portion main body A and includes a conductor 7 that supplies a high voltage and a spring 9 that is connected to a spark plug.

FIG. 7 is a sectional view of a main part showing a state in which the ignition coil is assembled to the engine main body. Reference numeral 10 denotes an ignition plug connected to a coil spring 9, one for each cylinder of a double overhead cam type four-cycle engine. Are arranged one by one. Reference numeral 11 denotes an engine body, and an ignition coil 13 composed of a coil part body A and a connector part B is housed and fixed in a plug hole. Reference numeral 12 denotes a coil fixing portion formed on the engine main body 11 for mounting and fixing the coil portion main body A.

Hereinafter, a method of assembling the ignition coil having the above configuration will be described. The coil unit 1 is housed in the resin case 2. Also, before storing the coil section 1, 2
The secondary terminal 3 for connecting the copper wire forming the end of the next winding is fixed. When the coil portion 1 is housed in the resin case 2, the protrusion 4b of the high voltage terminal 4 is press-fitted into a hole 3b provided at the center of the secondary terminal 3, and the protrusion 3a provided on the periphery of the hole 3b The projection 4b is electrically connected. Next, a thermosetting resin is injected between the coil portion 1 and the resin case 2 through an opening (not shown) of the resin case 2 to fix the coil portion.

The high-pressure tower 5 has a cylindrical shape, and is formed to have a ring-shaped convex portion 5a on the outer periphery of the center. The cap 4c of the high-pressure terminal 4 fixed to the inner periphery of the high-pressure tower 5 has a shape having a spherical concave portion 4b on the inner periphery.

 Thus, the coil unit main body A is assembled.

Next, a ring spring 8 is press-fitted through an opening 7c at the upper end of the cylindrical conductor 7, and a plurality of projections 8a provided on the outer periphery of the ring spring 8 are provided with a plurality of holes 7a provided at the upper end of the conductor 7.
To fit. By projecting the projection 8a to the outer periphery of the conductor 7 through the hole 7a, the ring spring 8
Is fixed in the cylinder of the conductor 7. The coil spring 9 connected to the ignition plug 10 is inserted and stored in the cap 7b at the lower end of the conductor 7. Then, the conductor 7 including the ring spring 8 and the spring 9 is closely fitted into the insulator 6 to obtain the connector portion B.

Next, the connector portion B is inserted into the coil portion main body A.
At this time, the concave portion 6a of the insulating resin body 6 is
And the insulating resin body 6 and the high-pressure tower 5 are assembled. That is, the connector portion B and the coil portion main body A are assembled. At this time, the hole 7a of the conductor 7 is
The plurality of hemispherical protrusions 8a of the ring spring 8 that are more protruding are formed in spherical concave portions provided on the inner periphery of the high-voltage terminal 4.
4a is fitted. And the ring spring 8 is provided on the projection 8a.
The restoring force acts on the concave portion 4a of the high-voltage terminal 4 so that the hemispherical projection 8a and the spherical concave portion 4a are electrically connected in a swingable state.

As described above, the ignition coil for an internal combustion engine of this embodiment is assembled as shown in FIG.

Here, the coil fixing portion 12 for fixing the coil portion main body A is
The high-pressure tower 5 (high-voltage terminal 4) of the coil unit main body A and the axis of the ignition plug 10 are designed to be concentric.

However, the high-pressure tower 5
If the ignition coil 13 is not concentric with the axis of the ignition plug 10, when the ignition coil 13 is housed and fixed in the engine main body 11, a misalignment occurs between the coil main body A and the connector portion B. However, since the hemispherical projection 8a and the spherical concave portion 4a are electrically connected in a swingable state, there is no danger of contact failure due to the misalignment absorbed at this connection. In addition, there is no fear of poor contact due to engine vibration.

Note that a plurality of hemispherical projections may be integrally provided on the conductor 7 instead of the ring spring 8.
Further, the shape of the projection provided on the conductor 7 is not limited to a hemisphere, but may be another shape such as a conical shape.

〔The invention's effect〕

As described above, in the ignition coil for an internal combustion engine of the present invention, the convex portion of the high-voltage tower is fitted into the concave portion of the insulating resin body and the coil body is assembled to the connector portion. The protrusions provided on the conductor are fitted into and electrically connected to the concave portions, so that even when the conductive member moves, the spherical concave portions and the protrusions are always connected, and the contact between the conductive material and the high-voltage terminal is poor. Therefore, there is an excellent effect that high voltage can be reliably supplied to the ignition plug.

Further, since the protrusion provided on the outer periphery of one end of the conductor and the spherical concave portion of the high voltage terminal are swingably fitted, not only the number of parts can be reduced, but also the connector can be inexpensively constructed, but also the connector can be manufactured at low cost. Since the attachment / detachment of the connector can be easily performed, there is an excellent effect that the workability of replacing the connector is good.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view of the ignition coil of the present invention, FIG. 2 is an enlarged view of a main part of the ignition coil of the present invention, FIG. 3 is a cross-sectional view of an insulating resin body, and FIG. Fig. 5 is an exploded front view showing a state before, Fig. 5 is a front view showing a state after a spring is assembled to a conductive material, Fig. 6 is a partial sectional front view showing a state before a conductive member is assembled to a coil body, FIG. 7 is a partial sectional front view showing a state in which the ignition coil is assembled to the engine. 1 ... coil part, 2 ... resin case, 3 ... secondary terminal, 4 ...
High voltage terminal, 5… High voltage tower, 6 …… Insulating resin body, 7…
… Conductive material, 8… Ring spring, 9 …… Coil spring.

Claims (1)

(57) [Claims] A coil portion including a primary winding and a secondary winding;
A resin case for accommodating the coil portion, a secondary terminal for connecting a copper wire forming an end of the secondary winding, a cylindrical high-pressure tower integrally formed with the resin case and a resin,
A coil portion main body fixed to the cylinder of the high-pressure tower and connected to the secondary terminal and having a cylindrical high-pressure terminal having a spherical concave portion on the inner periphery; and a cylindrical portion made of an elastic material. An insulating resin body, a cylindrical conductor fitted in the insulating resin body, a protrusion provided on the outer periphery of one end of the conductor, and connected to a spark plug housed in the other end of the conductor. A connector portion including a coil spring, and the connector portion and the coil portion main body are assembled by fitting the high-voltage tower and the insulating resin body together, and one end of the conductor. An ignition coil for an internal combustion engine, wherein a projection provided on an outer periphery and a spherical concave portion of a high voltage terminal are swingably fitted.