JP3447039B2 - Ignition device assembly structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembling structure of an ignition device for an internal combustion engine, and more particularly to an assembling structure of an ignition device in which a case containing an ignition coil and a plug cap are integrated.

[0002]

2. Description of the Related Art As an ignition device for an internal combustion engine, for example,
When a high voltage is distributed to each spark plug by a distributor, there are inconveniences such as wear of the power distribution unit and generation of electrical noise from the power distribution unit.Therefore, an ignition system without a distributor was developed to prevent these inconveniences. ing. One of such ignition systems is one in which a coil portion main body that generates a high voltage and an ignition plug are directly connected by a conductor connecting portion, and the high voltage of the coil portion main body is supplied to the ignition plug. .

FIG. 6 shows a conventional ignition device 5 in which an ignition coil case and a plug cap are integrated. The ignition device 5 includes an ignition coil case 51,
And a plug cap 52. A tubular portion 53 is provided so as to project from the lower end surface of the ignition coil case 51, and a collar-shaped projection 54 is provided on the lower side of the tubular portion 53. A terminal 55 is built in the plug cap 52, and a groove-shaped locking portion 56 is provided above the terminal 55.

As shown in FIG. 7, a cylinder head 57 is provided with a plug hole 58, and a plug cap 52 fitted with an ignition coil case 51 is fitted into the plug hole 58. The projection 54 of the ignition coil case 51 is engaged with the locking portion 56 of the plug cap 52.

[0005]

However, in the conventional ignition device 5, as shown in FIGS. 6 and 7, in order to prevent the ignition coil case 51 from coming off,
Since the projection 54 and the locking portion 56 of the plug cap 52 need to be fitted to each other, for example, the fitting portion may not be completely fitted at the time of assembly due to a dimensional error or insufficient insertion. There was a case where it was in a fitted state. Further, in the conventional fitting structure, there is a problem that it is not possible to easily confirm by visual inspection or the like whether or not the fitted state is correct.

Thus, when the projection 54 and the locking portion 56 are in a half-fitted state, not only the electrical connection is incomplete, but also the lower end surface of the ignition coil case 51 and the upper end surface of the plug cap 52 are separated. A gap is generated without being pressed, and water is introduced into the fitting portion during transportation before assembly into the engine, or during rainwater during assembly or packaging work, for example. When assembled in the engine and operating the engine in such a state, it causes an electrical trouble.

An object of the present invention is to solve the above problems, and it is possible to ensure the connection between the ignition coil case and the plug cap, and it is possible to easily confirm whether or not the connection state is firmly established. Another object of the present invention is to provide an ignition device assembly structure capable of reliably preventing water from entering between the ignition coil case and the plug cap.

[0008]

The above object of the present invention is to provide an ignition coil case having a plurality of locking claws on a lower surface thereof, and an upper surface flange portion at an end surface thereof, which is provided at a predetermined distance from the upper surface flange portion. A plug cap having a raised protrusion,
A plate having an opening through which the plug cap can penetrate and having a plurality of locking portions with which the locking claws engage, and the upper surface flange portion is sandwiched between the plate and the ignition coil case. As described above, it can be achieved by an ignition device assembly structure characterized in that the locking claw and the lock portion are engaged with each other.

In the assembling structure of the ignition device according to the present invention as described above, the plate is arranged below the upper flange of the plug cap, and the locking claw of the ignition coil case is engaged with the locking part of the plate. As a result, the upper surface flange portion is sandwiched between the ignition coil case and the plate, and the elastic restoring force causes the upper end surface of the upper surface flange portion to come into close contact with the lower end surface of the ignition coil case. Further, the plate can be temporarily attached so as not to fall between the collar portion and the protrusion due to the configuration in which the collar portion and the protrusion are provided at a predetermined distance from the collar portion.

Further, in the ignition device assembling structure according to the present invention, when the lock portion is formed by a slit opening and the locking claw is formed in a divergent shape capable of penetrating the slit opening, By inserting the locking claw into the slot opening, the widened portion of the locking claw is engaged with the lower edge of the slit opening.

Further, in the ignition device assembling structure according to the present invention, when the lock portion is formed by a notch provided on the outer peripheral edge of the plate, the locking claw is engaged with the notch. When this is done, even if the widened portion of the locking claw is relatively large, it can be easily engaged. Further, since the locking claws are received in the notches, the ignition coil case and the plug cap are connected so as not to rotate.

Further, in the ignition device assembling structure according to the present invention, the plate is formed into a polygonal shape or a substantially polygonal shape, and has a substantially linear engaging edge portion, and the locking claw is the above-mentioned. When the engaging claw is configured to engage with the engaging edge portion, the engaging claw can be easily engaged even if it is configured to be relatively wide. Further, since the plurality of locking claws are brought into the state of being engaged with the linear engagement edge portion, the ignition coil case and the plug cap are connected so as not to rotate. Also, the plate shape can be made simple.

Further, in the ignition device assembling structure according to the present invention, according to the structure in which the protrusion is formed in a brim shape and is pressed against the inner peripheral surface of the plug hole into which the plug cap is inserted, the plug cap is formed. It can be pressed against the inner peripheral surface of the plug hole into which is inserted.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the ignition device assembly structure according to the present invention will be described in detail below with reference to the drawings. FIG. 1 shows an ignition device assembly structure 1 according to the present invention. As can be seen from this figure, this ignition device assembly structure 1
Includes an ignition coil case 11, a plug cap 12 made of, for example, hard rubber, and a plate 13 annularly formed of a member having a relatively high rigidity such as metal.

The ignition coil case 11 supplies a high voltage to an ignition plug (not shown), and is formed in a rectangular parallelepiped shape. Then, the tubular portion 14 is provided at the center of the lower end surface of the ignition coil case 11,
At least two engaging claws 15 are provided on the periphery, one in each of the quadrangular sides in this embodiment, for a total of four engaging claws 15. Note that the locking claw 15 has a structure adapted to be appropriately caught by a slit opening 25 described later, and in the present embodiment, the locking claw 15 has a shape in which the tip end thereof is widened. There is.

The plug cap 12 is entirely formed in a tubular shape, and an upper surface flange portion 20 having an appropriate diameter is provided at the upper end. Below the upper surface brim portion 20, a protrusion 21 is provided at a predetermined distance from the brim portion. In the present embodiment, the protrusion 21 is formed in a brim shape with a sharp tip, and its diameter is slightly larger than the diameter of a plug hole 61 of a cylinder head 60 (see FIG. 3) described later. Further, the plug cap 12 is provided with a fitting hole 22 having a predetermined depth from the upper end surface thereof.
2 from the bottom surface of the plug cap 12 to the bottom surface of the terminal 23
A through hole 24 for inserting is provided.

The plate 13 has an appropriate thickness, and the diameter d of the opening 26 of the plate 13 is the upper flange portion 20 of the plug cap 12.
Is smaller than the cylinder diameter and slightly larger than the cylinder diameter. Further, on the outer peripheral side of the plate 13, a plurality of lock portions are provided in correspondence with the locking claws 15 of the ignition coil case 11,
In this embodiment, four slit openings 25 are provided.

Ignition device assembly structure 1 constructed in this way
Assemble it before installing it in the engine. First,
As shown in FIG. 2, the upper surface brim portion 20 of the plug cap 12 is
The plate 13 is inserted between the protrusion 21 and the protrusion 21. The position of the plate 13 is regulated by the upper surface flange portion 20 and the protrusion 21 to prevent the plate 13 from coming off.

Next, the cylindrical portion 1 of the ignition coil case 11 is inserted into the fitting hole 22 of the plug cap 12 in the state shown in FIG.
Insert 4. Next, the plate 13 is brought closer to the upper surface flange portion 20 side, and the locking claw 15 of the ignition coil case 11 is inserted into the slit opening 25 of the plate 13 and locked. As a result, the upper surface collar portion 20 is sandwiched between the ignition coil case 11 and the plate 13 at a predetermined pressure, and the elastic restoring force of the upper surface collar portion 20 causes the lower end surface of the ignition coil case 11 and the upper end surface of the upper collar portion 20 to be sandwiched. And are closely attached.

In this way, the plug cap 12, the ignition coil case 11, and the plate 13 are assembled and integrated, and the plug cap 11 is inserted into the plug hole 61 of the cylinder head 60 as shown in FIG.
Attach to. That is, after assembling, the plug cap 12 is inserted into the plug hole 61 of the cylinder head 60, the plug cap 12 is fitted into the spark plug (not shown), and the projection 21 is closely attached to the inner peripheral surface of the plug hole 61. Let This completes the mounting of the ignition device.

As described above, in this ignition device assembly structure 1, the upper surface flange portion 20 is sandwiched between the ignition coil case 11 and the plate 13 at a predetermined pressure,
Since the lower end surface of the ignition coil case 11 and the upper end surface of the upper flange portion 20 are brought into close contact with each other by the elastic restoring force of the upper flange portion 20, water is prevented from entering between the ignition coil case 11 and the plug cap 12. be able to.

The ignition device assembly structure according to the present invention is
A form as shown in FIGS. 4 and 5 can also be adopted.
In the embodiment shown in FIG. 4, the lock portion is the plate 13
This is the case where it is configured by the notches 45 (four notches in the present embodiment) provided on the outer peripheral edge of. In this case, the locking claws 15 (actually, there are four corresponding to the notches, but for the sake of convenience, only one is shown) have a configuration in which the tip end widening portion faces inward. Therefore, when the locking claw 15 is engaged with the notch 45, the notch 45
On the other hand, it is desirable to set the tip to be deformed outward (outward in the radial direction of the plate 13) so as to be in an engaged state using the elastic force of the locking claw 15. Further, in the case of the present embodiment, even if the widened portion of the tip of the locking claw 15 is relatively large, it can be easily engaged. Further, the locking claw 15 is received in the notch 45, and the ignition coil case and the plug cap are connected so as not to rotate.

In the embodiment shown in FIG. 5, the plate 13
Is formed into a substantially polygonal shape (quadrangle). That is,
The plate 13 has four substantially linear engagement edges 55. On the other hand, four locking claws 15 are formed inward so as to engage with the engagement edge portion 55. Also in the present embodiment, as in the case of the configuration shown in FIG. 4, even if the expanding portion of the locking claw 15 is relatively large,
The plate 13 can be easily engaged. Further, when the plurality of (four) locking claws 15 are engaged with the linear engagement edge portion 55, the ignition coil case and the plug cap are connected so as not to rotate. Further, in the present embodiment, the plate shape can be made simple.

Further, in the above embodiment, the embodiment in which the protrusion is formed in a brim shape has been described, but the assembly structure according to the present invention is not limited to the illustrated form, and its shape is not limited. It can be changed as appropriate.

[0025]

As described above, according to the ignition device assembling structure of the present invention, the plate is arranged below the upper flange of the plug cap, and the locking portion of the plate engages with the locking claw of the ignition coil case. Since the upper surface flange is sandwiched between the ignition coil case and the plate by engaging with, the engagement between the ignition coil case and the plate is ensured. Also, since the upper end surface of the upper flange is brought into close contact with the lower end surface of the ignition coil case by the elastic restoring force of the upper flange part, it is possible to prevent water from entering between the ignition coil case and the plug cap. , The waterproof function is improved. Further, according to the assembly structure of the present invention, the engagement state between the ignition coil case and the plate can be easily confirmed visually.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an ignition device assembly structure according to the present invention.

FIG. 2 is an external view showing the state of the middle stage of the assembly of the ignition device assembly structure according to the present invention.

FIG. 3 is a cross-sectional view showing a state in which the ignition device assembly structure according to the present invention is mounted on a cylinder head.

FIG. 4 is a main part perspective view showing another embodiment of the ignition device assembly structure according to the present invention.

FIG. 5 is a main part perspective view showing another embodiment of the ignition device assembly structure according to the present invention.

FIG. 6 is an exploded view showing a conventional ignition device assembly structure.

FIG. 7 is a cross-sectional view showing an ignition device assembly structure of a conventional example.

[Explanation of symbols]

1 Ignition device assembly structure 11 Ignition coil case 12 plug cap 15 Locking claw 20 Top surface brim 21 Protrusion 25 Slit opening (lock part) 26 openings 45 Notch (lock part) 55 Engagement edge (lock part)

Continuation of front page (56) Reference JP-A-9-126113 (JP, A) JP-A-9-112402 (JP, A) JP-A-63-116414 (JP, A) JP-A-63-164307 (JP , A) Actual development 63-172115 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02P 13/00 H01T 13/04 F02P 15/00

Claims (5)

(57) [Claims] 1. An ignition coil case having a plurality of locking claws on a lower surface thereof, a plug cap having an upper surface flange portion on an end surface thereof, and a projection provided at a predetermined distance from the upper surface flange portion, and the plug. A plate having an opening through which the cap can penetrate, and a plate having a plurality of lock portions with which the locking claws engage, and the upper surface flange portion is sandwiched between the plate and the ignition coil case. The ignition device assembly structure, wherein the locking claw and the lock portion are engaged with each other. 2. The ignition device assembly structure according to claim 1, wherein the lock portion is formed by a slit opening, and the locking claw is formed in a divergent shape that can penetrate the slit opening. . 3. The ignition device assembly structure according to claim 1, wherein the lock portion is formed by a notch provided in an outer peripheral edge of the plate. 4. The plate is formed in a polygonal shape or a substantially polygonal shape and has a substantially linear engaging edge portion, and the locking claw is configured to engage with the engaging edge portion. The ignition device assembly structure according to claim 1, wherein the ignition device assembly structure is provided. 5. The protrusion according to claim 1, wherein the protrusion is formed in a brim shape, and is configured to be in pressure contact with an inner peripheral surface of a plug hole into which the plug cap is inserted. Ignition device assembly structure.