JPH0658237A - Ignition coil device of internal combustion engine - Google Patents

Abstract

PURPOSE:To dissolve directional property at assembling together an ignition coil and a member on the other side so as to dispense with an adjusting operation to conform both air vent holes to each other, and facilitate the assembling work. CONSTITUTION:This ignition coil device is provided with an upper cap 8 of a high voltage joint 7 outward fitted to the high voltage tower 5 of an ignition coil 1 capably of being fitted at any assembling angle in a plug hole H, a seal flange 13 formed on the upper cap 8 and mounted between the ignition coil 1 and a cylinder head C, a coil side air vent hole 15 formed on the pressed contact face 3a of the ignition coil 1 and a joint side air vent hole 14 formed on the face 13a to be pressedly contacted of the seal flange 13 which are spaced from the axis L by radius (r), and an angle allowable groove 16 annularly formed on the pressed contact face 3a at radius (r) centering around the axis L. Hereby, even if both vent holes 14, 15 are not conformed to each other, both are surely communicated to each other through the angle allowable groove 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition coil device for an internal combustion engine, and more particularly to an ignition coil device for arranging the ignition coil on a cylinder head of the internal combustion engine to shorten a distance from an ignition plug. It is about.

[0002]

2. Description of the Related Art As a conventional ignition coil device for an internal combustion engine of this type, there is one disclosed in Japanese Utility Model Laid-Open No. 2-115969.

FIG. 6 is a sectional view showing an installed state of an ignition coil device for an internal combustion engine described in this conventional publication.

As shown in the figure, the support cylinder 51 of the ignition coil device has a joint terminal 52 built in along the axial center and is inserted into the plug hole H of the internal combustion engine from above. Lower cap 53 provided at the lower end of the support cylinder 51
Fits over the spark plug P in the plug hole H, and
The upper cap 54 provided on the upper end of the support cylinder 51 positions the support cylinder 51 by bringing its outer periphery into contact with the inner periphery of the plug hole H, and the integrally formed collar portion 55 is attached to the plug on the cylinder head C. Abut around the hole H,
Watertightness inside and outside the plug hole H is maintained. Support cylinder 51
A coil tower 56 is connected to the upper cap 54, and the ignition coil 57 supported on the coil tower 56 is
Coil terminal 58 and support cylinder 5 in the coil tower 56
The spark plug P is electrically connected to the spark plug P via the joint terminal 52 in the unit 1, and the spark plug P is supplied with a spark current.

An air vent hole 59 is vertically formed at one side of the collar portion 55 of the upper cap 54, and an air vent groove 60 is formed on the outer periphery of the upper cap 54 in correspondence with the air vent hole 59. The inside of the plug hole H and the upper side of the cylinder head C communicate with each other through the air vent hole 59 and the air vent groove 60.
When the support cylinder 51 is inserted into the plug hole H,
When the air in the plug hole H is thermally expanded due to the operation of the internal combustion engine, surplus air is discharged to the outside through the air vent hole 59 and the air vent groove 60.

By the way, the demand for miniaturization of the internal combustion engine has been rapidly increasing in recent years, and accordingly, the space allocatable to the ignition coil device is being surely reduced. Further, in the above-described ignition coil device, since the ignition coil 57 supported on the coil tower 56 protrudes largely upward, it is impossible to further reduce the installation space, and the space is further saved. As an open technical report issued by Nippondenso Co., Ltd., date of issue January 15, 1990,
The one described in the reference number 69-198 is proposed.

FIG. 7 is a cross-sectional view showing an installed state of an ignition coil device for an internal combustion engine described in the conventional technical report.

As shown in the figure, this ignition coil device is
By directly fixing the ignition coil 71 on the cylinder head C of the internal combustion engine, the height of the upward protrusion is reduced to save space. A fitting portion 72 is formed on the lower surface of the ignition coil 71 so as to face the inside of the plug hole H, and a rubber packing 73 is externally fitted to the fitting portion 72 so that the holder 74 can be removed downward. It is prevented. Packing 73
Is suppressed from above by the lower surface of the ignition coil 71, and its outer periphery is brought into close contact with the inner periphery of the plug hole H to maintain water tightness inside and outside the plug hole H. On one side of the ignition coil 71 and the packing 73, air vent holes 75 and 76 are provided corresponding to each other.
Through the air vent holes 75 and 76, the inside of the plug hole H communicates with the upper side of the cylinder head C,
Similar to the ignition coil device described above, the surplus air in the plug hole H is appropriately discharged to the outside.

The outer periphery of the fitting portion 72 and the packing 73
The inner circumference of is formed in a square shape in cross-section corresponding to each other, and the fitting portion 7 is formed only when both air vent holes 75 and 76 are aligned.
The packing 73 can be externally fitted to the No. 2, and as a result, consideration is given to prevent the occurrence of assembly failure due to the mismatch of the air vent holes 75 and 76. In this ignition coil device, a high-voltage tower 77 formed so as to project downward from the fitting portion 72 of the ignition coil 71 is directly connected to the ignition plug P via a plug cap 78.

On the other hand, in addition to the above two types of ignition coil devices, an ignition coil device of the type shown in FIG. 8 has been proposed in which the ignition coil is directly fixed on the cylinder head C.

FIG. 8 is a sectional view showing a state of installation of the conventional ignition coil device for an internal combustion engine. As shown in the figure, a rubber high pressure joint 83 is externally fitted to a high pressure tower 82 formed on the lower surface of the ignition coil 81, and a joint terminal is built in the high pressure joint 83 along the axial center. 84 is an ignition coil 81 and a plug hole H
It is electrically connected to a spark plug (not shown) therein. A seal collar 85 is integrally formed on the upper end of the high pressure joint 83,
An annular outer seal lip 86 formed on the outer periphery of the lower surface of the seal collar 85 abuts on the cylinder head C, and an annular inner peripheral side extending downward on the inner periphery of the lower surface of the seal collar 85. The seal lip 87 is in contact with the inner circumference of the plug hole H, and these seal lips 86 and 87 keep the inside and outside of the plug hole H watertight.

Here, as compared with the outer peripheral side seal lip 86 which simply contacts the cylinder head C to maintain watertightness, the inner peripheral side seal lip 87 elastically deforms and the plug hole H of the high pressure joint 83. Since it is necessary to allow insertion / removal into / from the inside, greater flexibility is required. Therefore, in this ignition coil device, sufficient flexibility is imparted by forming the void 88 in the inner circumference of the inner seal lip 83, and the high pressure joint 83 is inserted with a light operating force.
It is considered to be removable.

By the way, the above-mentioned ignition coil device is intended for an internal combustion engine having a relatively large diameter plug hole H in which there is room for forming a void 88 in the inner circumference of the inner seal lip 87. For example, in a DOHC type internal combustion engine in which the valve scissors angle is narrowed, there is no room for forming the void 88 because the plug hole H is required to have a small diameter. Therefore,
As an object for an internal combustion engine having such a small-diameter plug hole H, for example, an ignition coil device shown in FIG. 9 has been proposed.

FIG. 9 is a sectional view showing the installed state of another conventional ignition coil device for an internal combustion engine.

As shown in the figure, this ignition coil device is
Instead of the inner peripheral seal lip 87 described above, a seal lip 91 is formed so as to project over the entire outer periphery of the high pressure joint 83, and the insertion and removal of the high pressure joint 83 are performed while compressing and deforming the seal lip 91 in the radial direction. Be done.

[0016]

In the conventional ignition coil device described in the open technical report shown in FIG. 7, the outer periphery of the fitting portion 72 of the ignition coil 71 and the inner periphery of the packing 73 are square in cross section as described above. The packing 7 is formed on the fitting portion 72 by forming the packing 7
When the 3 is externally fitted, the air vent holes 75 and 76 are prevented from being inconsistent with each other, resulting in defective assembly. However, by taking this measure, it is necessary to adjust the angle of the packing 73 with respect to the fitting portion 72 during assembly, which is a factor that complicates the assembly work. Further, in both the ignition coil device described in the open technical report and the ignition coil device described in the publication shown in FIG. 6, the air vent holes 59 and 75 are simply formed upward, so that the cylinder head C is not formed. When water is flooded into the plug hole H through the air vent holes 59 and 75, the insulation of the high voltage joint between the support cylinder 51 and the high pressure tower 77 and the ignition plug P is lowered, causing ignition failure. There was a possibility to do.

Therefore, an object of the present invention is to eliminate the assembling directionality of the ignition coil and the mating member, and to eliminate the need for an adjusting operation for aligning the air vent holes of both members, thus facilitating the assembling work. It is an object of the present invention to provide an ignition coil device for an internal combustion engine, which can be realized and which can prevent ignition failure due to water ingress into the plug hole from the air vent hole.

On the other hand, in the ignition coil device for the small-diameter plug hole H shown in FIG. 9, the seal lip 91 is compressed and deformed in the radial direction as described above, so that the high pressure joint 83 is inserted into and removed from the plug hole H. Is allowed. However, since the seal lip 91 is a solid body and the flexibility is not enhanced by utilizing the gap 88 unlike the inner peripheral side seal lip 87 shown in FIG. 8, it is difficult to compress and deform.
Therefore, in order to secure the sealing property with respect to the plug hole H, if the outer diameter of the seal lip 91 is set to be large and the inner circumference of the plug hole H is strongly pressed, the high pressure joint 8
When inserting / removing No. 3, a considerable operating force is required, which may deteriorate the maintainability of the internal combustion engine.

Incidentally, such a defect is caused by the seal lip 9
The present invention is not limited to 1, but also occurs when the support cylinder 51 is positioned in the plug hole H on the outer periphery of the upper cap 54 as in the ignition coil device shown in FIG. In other words, if the outer diameter of the upper cap 54 is set to be large and the inner circumference of the plug hole H is strongly pressed to secure the positionality of the support cylinder 51 with respect to the plug hole H, the support cylinder 51 is similarly pressed as described above. It requires a considerable amount of operating force when inserting or removing.

Therefore, the object of the invention of claim 2 is, in addition to the object of the invention of claim 1, that even if the plug hole has a small diameter, a light operation is ensured while ensuring the sealing property and the positioning property. It is an object of the present invention to provide an ignition coil device for an internal combustion engine, which can be inserted / removed by force and can be improved in maintainability of the internal combustion engine.

[0021]

According to a first aspect of the present invention, there is provided an ignition coil device for an internal combustion engine, wherein an ignition coil is fixed to an opening of a plug hole of a cylinder head, and is inserted and arranged in the plug hole. The outer end is externally fitted to the high-voltage tower of the ignition coil so as to be freely assembled around the shaft center, and the inner end is connected to an ignition plug, and the outer end of the high-pressure joint is formed integrally with the high-pressure joint. The pressure contact surface of the ignition coil is pressed against the cylinder head side of the pressure contact surface, and the seal flange is in contact with the periphery of the plug hole, and the seal flange is on a predetermined radius about the axis of the pressure contact surface of the seal flange. A joint-side air vent hole formed to communicate with the inside of the plug hole and a predetermined radius centered on the axial center of the pressure contact surface of the ignition coil are formed and communicated with the outside of the ignition coil. Coil side air vent hole, an angle allowance groove formed in an arc shape with a predetermined radius centered on the shaft center on either the pressure contact surface or the pressure contact surface, and the coil side air vent hole outside the ignition coil. And a shielding member provided directly above the opening portion of the.

In the ignition coil device for an internal combustion engine according to a second aspect of the present invention, a contact portion that elastically contacts the inner periphery of the plug hole is provided on the outer peripheral side near the outer end of the high pressure joint. The inner peripheral side and / or the outer peripheral side of the high-pressure tower is provided with a relief portion that forms a deformation-allowable space corresponding to the contact portion.

[0023]

According to the invention of claim 1, when the outer end of the high pressure joint is fitted onto the high pressure tower of the ignition coil even if the joint side air vent hole and the coil side air vent hole do not match,
Both air vent holes are surely communicated via the angle allowance groove formed on the same radius, so the directionality of the assembly of the ignition coil and the high pressure joint is eliminated, and no adjustment operation is required to match both air vent holes. Becomes Further, since the opening portion of the coil side air vent hole is shielded from above by the shielding member, there is almost no possibility of rainwater or the like entering the coil side air vent hole even when the cylinder head is exposed to water.

According to the second aspect of the present invention, since only the relief portion is formed on the inner peripheral side of the high-pressure joint or the outer peripheral side of the high-pressure tower, there is almost no need to increase the outer diameter of the high-pressure joint, and a small-diameter plug is used. The outer diameter can be reduced to the extent that it can be inserted sufficiently into the hole. When the high-pressure joint is inserted into or removed from the plug hole, the abutment part is deformed in the radial direction while deforming the deformation allowance space on the inner peripheral side. Becomes smaller.

[0025]

【Example】

 <First Embodiment> A first embodiment of the present invention will be described below.

FIG. 1 is a sectional view showing an installed state of an ignition coil device for an internal combustion engine which is a first embodiment of the present invention, and FIG. 2 is an ignition coil for an ignition coil device for an internal combustion engine which is a first embodiment of the present invention. And an exploded perspective view of the high pressure joint, and FIG. 3 is a sectional view taken along line XX of FIG. 1 showing coil side air vent holes of an ignition coil device for an internal combustion engine which is a first embodiment of the present invention.

As shown in the drawing, the ignition coil 1 of the ignition coil device is made of synthetic resin, and has a main body 2 as a shielding member in the shape of a rectangular box on the upper side, a pressing plate 3 in the shape of a lower disk, and a main body 2. And a pressing plate 3 and a cylindrical high-pressure tower 5 projecting downward at the center of the lower surface of the pressing plate 3. A pair of mounting portions 6 are provided on the side surface of the main body 2, and the ignition coil 1 is fixed on the cylinder head C of the internal combustion engine by bolts (not shown) through these mounting portions 6, and the high pressure tower 5 is a cylinder. It faces the plug hole H formed in the head C. A rubber high pressure joint 7 extending vertically is inserted and arranged in the plug hole H, and an upper cap 8 integrally formed on the upper end of the high pressure joint 7 is elastically fitted onto the high pressure tower 5 of the ignition coil 1. , Lower cap 9 integrally formed on the lower end
Is a spark plug P installed at the bottom of the plug hole H
It is elastically fitted on.

A joint terminal 10 is built in the high-pressure joint 7 along the axis, the upper end of the joint terminal 10 is connected to the connection terminal 5a in the high-voltage tower 5, and the lower end of the joint terminal 10 is the terminal spring 1.
1 to the terminal P1 of the spark plug P.
The coil (not shown) wound around the core 12 in the main body 2 of the ignition coil 1 is electrically connected to the ignition plug P via the joint terminal 10 and supplies an ignition current to the ignition plug P. The high pressure tower 5, the high pressure joint 7 and the ignition plug P of the ignition coil 1 are located on the same axis L, and the upper cap 8 and the lower cap 9 of the high pressure joint 7 are arranged.
Are externally fitted to the high-pressure tower 5 and the spark plug P so as to be freely assembled with the axis L as the center. That is,
The high-pressure joint 7 can be installed at any angle around the axis L.

A disc-shaped sealing collar 13 is integrally formed at the open end of the upper cap 8 of the high-pressure joint 7, and the sealing collar 13 is interposed between the cylinder head C and the restraining plate 3 of the ignition coil 1. There is. The pressure contact surface 13a on the upper surface of the seal flange 13 is pressed against the pressure contact surface 3a on the lower surface of the pressing plate 3 from above, and as a result, the annular seal lip 13b formed on the outer peripheral edge of the lower surface of the seal flange 13 is connected to the cylinder head C. The watertightness inside and outside the plug hole H is maintained by making contact with the periphery of the upper plug hole H.

A small-diameter joint-side air vent hole 14 is vertically provided through the seal collar 13 on the radius r from the axis L, and similarly, on the radius r from the axis L of the suppressing plate 3 of the ignition coil 1 on the radius r. The coil side air vent hole 15 having the same diameter as the joint side air vent hole 14 is vertically provided. Also,
An annular angle allowance groove 16 having a radius r around the axis L is formed on the pressure contact surface 3a of the pressing plate 3.
Communicates with the coil side air vent hole 15. Here, as described above, since the joint side air vent hole 14 is also located at the radius r from the axis L, the angle tolerance is irrelevant regardless of the assembly angle of the high pressure joint 7 with respect to the axis L of the high pressure joint 7. The groove 16 always corresponds to the joint side air vent hole 14.

On the side surface of the connecting portion 4 of the ignition coil 1,
Rib portion 17 having a square cross section for connecting the main body 2 and the holding plate 3
A rectangular communication window 18 is formed in the upper portion of one side surface of the rib portion 17 adjacent to the lower surface of the main body 2 and the side surface of the connecting portion 4. Here, the portions of the rib portion 17 surrounding the two side surfaces in the communication window 18 are respectively covered by the shielding wall 1.
7a and 17b. The coil side air vent hole 15 extends upward in the rib portion 17 from the side of the restraining plate 3 and opens in the communication window 18, and opens to the outside via the communication window 18. The opening of the coil side air vent hole 15 in the communication window 18 is shielded by the main body 2 from above, and the connection portion 4 and the shield walls 17a and 17b are provided with three openings.
It is shielded from the side.

On the other hand, on the outer circumference of the upper cap 8 of the high-pressure joint 7, a positioning ridge 19 is formed as an abutting portion so as to surround the entire circumference, and the outer circumference of the positioning ridge 19 is self-elastic. The high pressure joint 7 is pressed against the inner circumference of the plug hole H and the high pressure joint 7 is positioned at the center of the plug hole H. An air vent groove 20 is formed on one side of the positioning ridge 19 for communicating the upper and lower sides of the plug hole H, and the lower portion of the plug hole H includes the air vent groove 20, the joint side air vent hole 14, and the angle. The air in the plug hole H can be freely discharged by communicating with the upper side of the cylinder head C through the allowance groove 16, the coil side air vent hole 15 and the communication window 18.

Further, at a height corresponding to the positioning protrusion 19 on the inner circumference of the upper cap 8, an annular escape groove 21 as an escape portion is provided so as to surround the high pressure tower 5 of the ignition coil 1.
The escape groove 21 forms a deformation permitting space 22 having a semicircular cross section on the outer periphery of the high-pressure tower 5.
Then, when the positioning ridge 19 is compressed and deformed in the radial direction during insertion into the plug hole H, the deformation allowance space 22 is deformed accordingly, and the positioning ridge 19 is allowed to be compressed and deformed. . That is, due to the action of the deformation permitting space 22, the positioning ridge 19 is provided with sufficient flexibility. Here, as is clear from FIG. 1, since the upper cap 8 of the high-pressure joint 7 has only the escape groove 21 formed on the inner periphery thereof,
There is almost no need to increase the outer diameter, and the outer diameter can be reduced to such an extent that it can be sufficiently inserted even in a small-diameter plug hole H.

Although the above-mentioned escape groove 21 is an undercut from the viewpoint of molding, it is formed by so-called forced pulling in which the product is forcibly pulled out from the molding die after the upper cap 8 is vulcanized and molded.

Next, a procedure for mounting the ignition coil device having the above-mentioned configuration on the internal combustion engine will be described.

Prior to the mounting work, first, the upper cap 8 of the high pressure joint 7 is fitted onto the high pressure tower 5 of the ignition coil 1 in order to connect the ignition coil 1 and the high pressure joint 7.
Therefore, the high-voltage tower 5 is held inside by the elastic force of the upper cap 8, and the joint terminal 10 of the high-voltage joint 7 is connected to the connection terminal 5 a in the high-voltage tower 5.
And the two members 1 and 7 are joined together. At this time, the pressure-contacted surface 13 of the seal collar 13 of the high-pressure joint 7
a is in contact with the pressure contact surface 3a of the pressing plate 3 of the ignition coil 1,
The joint side air vent hole 14 is made to correspond to the angle allowance groove 16 on the press contact surface 3a side. Here, since the upper cap 8 of the high-pressure joint 7 is fitted onto the high-pressure tower 5 of the ignition coil 1 so as to be freely assembled around the axis L, a joint side air vent hole 14 around the axis L is formed. In many cases, the phases of the coil side air vent holes 15 do not match, but even in such a case, the joint side air vent holes 14 are not allowed to have the angle allowable groove 16.
Through the air vent hole 15 on the coil side. That is, when the high-voltage joint 7 is connected to the ignition coil 1, no adjustment operation for matching the air vent holes 14 and 15 is required, and the upper cap 8 of the high-pressure joint 7 for the high-voltage tower 5 of the ignition coil 1 is not required. It is possible to combine them without considering the assembly angle of.

Next, the ignition coil 1 and the high-pressure joint 7 after being joined are held, and the high-pressure joint 7 is inserted into the plug hole H of the internal combustion engine. Therefore, the lower cap 9 of the high-pressure joint 7 is fitted onto the ignition plug P, the internal terminal spring 11 is connected to the terminal P1 of the ignition plug P, and the ignition plug P is connected to the inside of the ignition coil 1 via the joint terminal 10. Conducts with the coil. Further, the outer periphery of the positioning protrusion 19 of the high-pressure joint 7 is pressed against the inner periphery of the plug hole H by its own elasticity, and the high-pressure joint 7 is positioned at the center of the plug hole H.

Since the positioning ridge 19 when inserted into the plug hole H is compressed and deformed in the radial direction while deforming the deformation permitting space 22 on the inner peripheral side, the action of the deformation permitting space 22 is performed. Gives sufficient flexibility. Therefore, the resistance when the positioning ridge 19 makes sliding contact with the inner circumference of the plug hole H is extremely small, and the high-pressure joint 7 can be inserted with a light operating force. On the contrary, when the high pressure joint 7 is detached from the inside of the plug hole H, the positioning protrusion 19
Since it has a small sliding contact resistance, it can be executed with a light operating force.

After that, the mounting portion 6 of the main body 2 of the ignition coil 1
Is fixed to the cylinder head C with bolts, the pressure contact surface 3a of the ignition coil 1 is pressed against the pressure contact surface 13a of the seal flange 13 of the high-pressure joint 7 from above, and the seal flange 13
The seal lip 13b comes into contact with the periphery of the plug hole H on the cylinder head C. As a result, the watertightness inside and outside the plug hole H is maintained by the seal lip 13b, and the mounting work of the ignition coil device is completed.

Incidentally, the plug hole H of the high pressure joint 7
Excessive air in the plug hole H due to the insertion into the inside, the air vent groove 20, the joint side air vent hole 14, the angle allowance groove 1
6, the air is discharged above the cylinder head C through the coil side air vent hole 15 and the communication window 18, so that the plug hole H
There is no possibility that the air is compressed inside and the insertion operation of the high pressure joint 7 is hindered. Also, after mounting the ignition coil device,
Even when the air in the plug hole H is thermally expanded due to the operation of the internal combustion engine, the surplus air is discharged above the cylinder head C, so that the internal pressure of the plug hole H rises and various ignition coil devices are provided. There is no risk of adverse effects.

On the other hand, when the vehicle is running in the rain, the cylinder head C may be flooded by rainwater that has entered the engine room. Here, in the ignition coil device of the present embodiment, the opening portion of the coil side air vent hole 15 in the communication window 18 is shielded from above by the main body 2 of the ignition coil 1, and the connecting portion 4 and the shield walls 17a, 17b are provided. Since it is shielded from 3 sides, rainwater or the like is unlikely to enter the coil side air vent hole 15 regardless of the direction in which it is exposed to water. Since it is possible to prevent water from being exposed in a direction other than the opening direction of the communication window 18 in this manner, it is desirable to install the ignition coil device so that the communication window 18 faces the direction with the least possibility of water exposure. .

As described above, the ignition coil device for the internal combustion engine of the first embodiment is fixed to the opening of the plug hole H formed in the cylinder head C of the internal combustion engine, and the high pressure tower is directed toward the inside of the plug hole H. 5, the ignition coil 1 having a protruding shape is inserted and arranged in the plug hole H, and the upper cap 8 is externally fitted to the high-voltage tower 5 of the ignition coil 1 with the axis L as the center. And connect the lower cap 9 to the spark plug P in the plug hole H,
A rubber-made high pressure joint 7 for electrically connecting the ignition coil 1 and the ignition plug P at a joint terminal 10 built in along the axis L, and an upper cap 8 of the high pressure joint 7.
Is integrally formed on the cylinder head C and is interposed between the cylinder head C and the ignition coil 1. The pressure contact surface 3a formed on the pressing plate 3 of the ignition coil 1 presses the pressure contact surface 13a to the cylinder head C side. And the seal collar 13 for bringing the seal lip 13b into contact with the periphery of the plug hole H, and the seal collar 1
3, a joint-side air vent hole 14 is formed vertically through a radius r centered on the axis L of the No. 3, and vertically extends over a radius r centered around the axis L of the holding plate 3 of the ignition coil 1. Has been
A coil side air vent hole 15 opening in a communication window 18 formed in the ignition coil 1, and an angle allowance groove 16 formed in an annular shape with a radius r centered on the axis L on the pressure contact surface 3a of the ignition coil 1. The main body 2 of the ignition coil 1, which is located immediately above and on the side of the opening of the coil side air vent hole 15 in the communication window 18, the connecting portion 4, and the shielding walls 17a and 17b are provided. This configuration corresponds to the invention of claim 1.

Therefore, the high voltage tower 5 of the ignition coil 1
When the upper cap 8 of the high pressure joint 7 is fitted onto the
Even if the joint side air vent hole 14 and the coil side air vent hole 15 do not coincide with each other, both air vent holes 14 and 15 are surely communicated with each other through the angle allowance groove 16 formed on the same radius r. Therefore, the directionality of the assembling of the ignition coil 1 and the high-pressure joint 7 is eliminated, and the adjusting operation for aligning the air vent holes 14 and 15 of both is unnecessary, and the assembling work can be facilitated.

Further, the opening portion of the coil side air vent hole 15 is shielded from above by the main body 2 of the ignition coil 1 and is shielded from the three sides by the connecting portion 4 and the shield walls 17a and 17b. Even when the head C gets wet,
There is almost no possibility that rainwater or the like will enter the coil side air vent hole 15. Therefore, it is possible to prevent ignition failure of the ignition plug P due to water ingress into the plug hole H and improve reliability of the internal combustion engine.

On the other hand, in the ignition coil device for the internal combustion engine of the first embodiment described above, the positioning ridge 19 elastically abutting the inner circumference of the plug hole H is formed on the outer circumference of the upper cap 8 of the high pressure joint 7. At the same time, on the inner peripheral side of the upper cap 8, there is provided an annular relief groove 21 corresponding to the positioning projection 19 and forming a deformation permitting space 22 having a semicircular cross section.
This configuration corresponds to the invention of claim 2.

Therefore, since the escape groove 21 is only formed on the inner circumference of the upper cap 8, there is almost no need to increase the outer diameter of the upper cap 8 and the outer diameter is sufficient to be inserted into the small-diameter plug hole H. The diameter can be reduced. When the high-pressure joint 7 is inserted into or removed from the plug hole H, the positioning ridges 19 allow the deformation allowable space 22 on the inner peripheral side.
Since it is compressed and deformed in the radial direction while deforming, the resistance at the time of sliding contact with the inner circumference of the plug hole H becomes extremely small.

Therefore, even when the plug hole H has a small diameter, it is possible to sufficiently secure the positioning of the high-pressure joint 7 by the positioning ridges 19 and perform the insertion / removal operation with a light operating force. Therefore, the maintainability of the internal combustion engine can be improved.

<Second Embodiment> A second embodiment of the present invention will be described below.

FIG. 4 is a sectional view showing an installed state of an ignition coil device for an internal combustion engine according to a second embodiment of the present invention, and FIG. 5 is an ignition coil for an ignition coil device for an internal combustion engine according to a second embodiment of the present invention. FIG. 3 is an exploded perspective view of a high pressure joint. The overall structure of the ignition coil device of the present embodiment is the same as that of the ignition coil device of the first embodiment described above, except for the relationship between the joint side air vent hole 31 and the angle allowance groove 32, and the deformation. Because of the structure of the permissible space 36, the differences will be mainly described.

As shown in the figure, in the ignition coil device of this embodiment, a pair of joint side air vent holes 31 are provided 180 degrees opposite to each other on the radius r from the axis L of the seal collar 13 of the high pressure joint 7. Has been done. Further, the pressure contact surface 3a of the ignition coil 1 is formed with an arc-shaped angle allowance groove 32 having a radius r over a region of 180 degrees around the axis L, and the angle allowance groove 32 is the same as in the first embodiment. Further, it communicates with one coil side air vent hole 33 formed in the restraining plate 3. Therefore, the angle allowance groove 32 always corresponds to one of the joint-side air vent holes 31 regardless of the assembly angle of the high-pressure joint 7 with respect to the high-pressure tower 5 about the axis L.

On the other hand, on the inner periphery of the upper cap 8 of the high-pressure joint 7, a step portion 34 is formed at a height corresponding to the lower edge of the positioning ridge 19 on the outer peripheral side. It has a large diameter. Further, a step portion 35 is formed on the outer periphery of the high-voltage tower 5 of the ignition coil 1 at a height corresponding to the upper edge of the positioning protrusion 19 when the high-pressure joint 7 is assembled. Has a smaller diameter. Therefore, due to the difference between the vertical positions of the step portions 34 and 35, the deformation allowance space 36 having a substantially rectangular cross section is formed corresponding to the height of the positioning ridge 19. Further, in this embodiment, the stepped portions 34 and 35 form an escape portion.

As is clear from the figure, these stepped portions 34 and 35 do not undercut during molding of the high-pressure joint 7 and the high-pressure tower 5, so that there is no need to force removal as in the first embodiment. The deformation allowable space 36 can be formed.

Since the ignition coil device of this embodiment is constructed as described above, when the upper cap 8 of the high pressure joint 7 is fitted onto the high pressure tower 5 of the ignition coil 1 in the same manner as in the first embodiment. Even if the joint side air vent hole 31 and the coil side air vent hole 33 do not match, both air vent holes 31,
The 33 is surely communicated with each other via the angle allowing groove 32 formed on the same radius r. Therefore, the assembling directionality of the ignition coil 1 and the high-pressure joint 7 is eliminated, and the air vent holes 3 of both sides are eliminated.
It is not necessary to perform an adjusting operation for matching the numbers 1 and 33, and the assembling work can be facilitated.

Further, since only the step portions 34 and 35 are formed on the inner circumference of the upper cap 8 and the outer circumference of the high pressure tower 5, the outer diameter can be reduced to such an extent that the plug hole H having a small diameter can be sufficiently inserted. In addition, when the high-pressure joint 7 is inserted into or removed from the plug hole H, the positioning projections 19 are deformed in the radial direction while deforming the deformation allowance space 36 on the inner peripheral side. The resistance when slidingly contacting the inner circumference of the hole H becomes extremely small. Therefore, even if the plug hole H has a small diameter, it is possible to sufficiently secure the positioning of the high-pressure joint 7 by the positioning ridge 19 and to perform the insertion / removal operation with a light operating force. The maintainability of the internal combustion engine can be improved.

By the way, the angle allowance groove of the first embodiment is configured as an annular angle allowance groove 16 formed on the pressure contact surface 3a of the ignition coil 1, and the angle allowance groove of the second embodiment is a 180 degree circle. Although it is configured as the arc-shaped angle-allowing groove 32, the present invention is not limited to this, and is not always limited to this, regardless of the assembly angle of the high-pressure joint 7 with respect to the high-pressure tower 5, the joint side is always provided. Air vent hole 1
It is only necessary to connect 4, 31 and the coil side air vent holes 15, 33 to each other. So, for example,
These angle allowance grooves 16 and 32 may be formed on the pressure contact surface 13a of the seal collar 13 on the high pressure joint 7 side. Regarding the formation length, in addition to the annular shape and the 180-degree arc shape, for example, it may be formed in a 90-degree arc shape, and corresponding air vent holes on the other side may be formed at four positions at 90-degree intervals. Even in this case, the joint side air vent hole and the coil side air vent hole can always be communicated with each other through the angle allowing groove.

Further, the abutting portions of the first and second embodiments are configured as the positioning projections 19 for the purpose of positioning the high pressure joint 7 in the plug hole H. However, the present invention is not limited to this, and is formed on the outer circumference of the high pressure joint 7 and elastically presses against the inner circumference of the plug hole H to insert / remove the high pressure joint 7 into / from the plug hole H. The purpose is not limited as long as flexibility is required in this case. Therefore, for example, like the ignition coil device shown in FIG. 9 described in the related art, it is configured as a seal lip projectingly provided on the entire outer periphery of the high pressure joint 7, and the escape groove 21 is formed on the inner peripheral side of the seal lip. Alternatively, the deformation allowance spaces 22 and 36 may be formed by the step portions 34 and 35 to secure the flexibility of the seal lip.

Further, the relief portion of the first embodiment is the relief groove 2 formed on the inner circumference of the upper cap 8 of the high pressure joint 7.
1, the relief portion of the second embodiment is configured as a step portion 34 formed on the inner circumference of the upper cap 8 and a step portion 35 formed on the outer circumference of the high pressure tower 5,
When the present invention is carried out, the present invention is not limited to this, and flexibility is imparted to the contact portions such as the positioning ridges 19 and the seal lips formed on the outer peripheral side of the upper cap 8 of the high pressure joint 7. Anything is possible. Therefore, for example, it may be configured as an escape groove formed on the outer periphery of the high-pressure tower 5.

[0058]

As described above, in the ignition coil device for an internal combustion engine according to the invention of claim 1, when the outer end of the high pressure joint is fitted onto the high pressure tower of the ignition coil, the joint side air vent and the coil side air are introduced. Even if the holes do not coincide with each other, the two air holes are surely communicated with each other through the angle allowing grooves formed on the same radius. Therefore, the directionality of the assembling of the ignition coil and the high-pressure joint is eliminated, and the adjustment operation for matching the air vent holes of both is unnecessary, and the assembling work can be facilitated. Further, since the opening portion of the coil side air vent hole is shielded from above by the shielding member, there is almost no possibility of rainwater or the like entering the coil side air vent hole even when the cylinder head is exposed to water. Therefore, it is possible to prevent ignition failure of the spark plug due to water ingress into the plug hole and improve the reliability of the internal combustion engine.

In the ignition coil device for an internal combustion engine according to a second aspect of the present invention, since the relief portion is formed only on the inner peripheral side of the high pressure joint and the outer peripheral side of the high pressure tower, it can be sufficiently inserted into a small-diameter plug hole. The outer diameter of the high-pressure joint can be reduced to the extent possible. When the high-pressure joint is inserted into or removed from the plug hole, the abutment part is deformed in the radial direction while deforming the deformation allowance space on the inner peripheral side. Becomes smaller. Therefore, even if the plug hole has a small diameter, it can be inserted with a light operating force while ensuring the sealing and positioning of the contact part.
The disengagement operation can be performed, and the maintainability of the internal combustion engine can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an installed state of an ignition coil device for an internal combustion engine which is a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of an ignition coil and a high pressure joint of an ignition coil device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along line XX of FIG. 1 showing coil side air vent holes of an ignition coil device for an internal combustion engine that is a first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing an installed state of an ignition coil device for an internal combustion engine which is a second embodiment of the present invention.

FIG. 5 is an exploded perspective view of an ignition coil and a high pressure joint of an ignition coil device for an internal combustion engine according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view showing an installed state of an ignition coil device for an internal combustion engine described in a conventional publication.

FIG. 7 is a cross-sectional view showing an installed state of an ignition coil device for an internal combustion engine described in a conventional open technical report.

FIG. 8 is a cross-sectional view showing an installed state of a conventional ignition coil device for an internal combustion engine.

FIG. 9 is a cross-sectional view showing an installed state of another conventional ignition coil device for an internal combustion engine.

[Explanation of symbols]

 1 Ignition coil 2 Main body (shielding member) 3a Pressure contact surface 5 High pressure tower 7 High pressure joint 13 Seal flange 13a Pressure contact surface 14,31 Joint side air vent hole 15,33 Coil side air vent hole 16,32 Angle allowance groove 19 Positioning protrusion (Abutting part) 21 Escape groove (Escape part) 22,36 Deformation allowance space 34,35 Step part (Escape part) C Cylinder head H Plug hole P Spark plug

Claims (2)

[Claims] 1. An ignition coil fixed to an opening of a plug hole formed in a cylinder head of an internal combustion engine and having a high-pressure tower projecting toward the inside of the plug hole, and an elastic coil having an insulating property. The shaft is inserted and arranged in the hole, and the outer end is fitted onto the high-voltage tower of the ignition coil so that it can be freely assembled around the shaft center, and the inner end is connected to the spark plug in the plug hole. A high-pressure joint for electrically connecting the ignition coil and the ignition plug with a joint terminal built along the core, and an integrally formed outer end of the high-pressure joint, which is interposed between the cylinder head and the ignition coil. A seal flange that is pressed against the cylinder head side by a pressure contact surface formed on the side of the plug hole, and a seal flange that contacts the periphery of the plug hole; And a joint side air vent hole communicating with the inside of the plug hole, and an opening formed on the predetermined radius centered on the axial center of the pressure contact surface of the ignition coil. In addition, the coil side air vent communicating with the outside of the ignition coil, and either the pressure contact surface of the ignition coil or the pressure contact surface of the seal flange is formed in an arc shape with the predetermined radius around the axis. An ignition coil device for an internal combustion engine, comprising: an angle permitting groove formed therein; and a shielding member provided immediately above an opening of a coil side air vent hole on the outside of the ignition coil. 2. A contact portion, which elastically contacts the inner circumference of the plug hole, is provided on the outer peripheral side near the outer end of the high pressure joint, which is externally fitted to the high pressure tower. Alternatively, the ignition coil device for an internal combustion engine according to claim 1, wherein an escape portion that forms a deformation allowable space corresponding to the contact portion is provided on the outer peripheral side of the high pressure tower.