JP2003083219A - Ignition device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition device for an internal combustion engine capable of simplifying m assembling work to a cylinder head regarding an ignition plug and a plug hole pipe. SOLUTION: In the ignition device 1 for an internal combustion engine, a pipe-integrated ignition plug integrally constituted by fixing of the ignition plug 11 having no screw groove on a main fitting 19 and the plug hole pipe 31 is used. It is not required that the assembling work to the cylinder head 51 is separately and independently carried out regarding the ignition plug 11 and the plug hole pipe 31, thereby, troublesomeness of the fixing work to the cylinder head 51 can be solved. Since the pipe-integrated ignition plug 9 is not fixed by threading but is clamped to a second wall surface 51d by press- fitting to a plug arrangement hole 51 of the cylinder head 51, an arrangement position of an earth electrode 21 in a combustion chamber 55 is easily set at a specified position where an ignition property can be obtained well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine, which includes an ignition plug attached to each cylinder of an internal combustion engine and generates spark discharge for igniting an air-fuel mixture at the ignition plug.

[0002]

2. Description of the Related Art Conventionally, in an internal combustion engine used for an automobile engine or the like, a spark plug used for igniting an air-fuel mixture is generally a center electrode inserted in a tip end side of a shaft hole of an insulator. And a metal shell provided outside the insulator,
A ground electrode, one end of which is coupled to the metal shell and the other end of which faces the center electrode across the spark discharge gap, is inserted into the rear end side of the shaft hole of the insulator, and is electrically connected to one end of the center electrode. And a terminal electrode to be connected.

Such an ignition plug is attached to a cylinder head of an internal combustion engine for practical use, and constitutes an internal combustion engine ignition device together with an ignition coil and the like. In this ignition device for an internal combustion engine, a high voltage for ignition generated by the ignition coil is applied to the spark plug, so that spark discharge is generated in the spark discharge gap of the spark plug, and a spark mixture is discharged to the air-fuel mixture in the combustion chamber. Ignite.

By the way, the cylinder head of the internal combustion engine is provided with an intake / exhaust valve drive mechanism including a camshaft for driving an intake valve and an exhaust valve in addition to the spark plug. Lubricating oil for circulating the intake / exhaust valve drive mechanism is circulated. Since the spark plug has a structure that generates a spark discharge by applying a high voltage as described above, if the lubricating oil adheres to the spark plug, a spark discharge is normally generated due to the influence of an electric leak or the like. I may not be able to.

Therefore, in the internal combustion engine, the cylinder head in which the intake / exhaust valve drive mechanism is arranged is formed to have an inner diameter through which the spark plug can be inserted (in other words, the spark plug can be housed inside). ) A cylindrical plug hole pipe is provided to form a spark plug installation space and
Isolating the spark plug from lubricating oil. The plug hole pipe is fixed to the cylinder head with its axial direction being the same as the axial direction of the spark plug.

[0006]

However, when an ignition plug which is a part of an internal combustion engine ignition device is mounted on an internal combustion engine having a plug hole pipe, the plug hole pipe is fixed to a cylinder head. Since the spark plug will be mounted deeper into the elongated plug hole pipe later, the work of mounting the spark plug becomes complicated. In particular, in DOHC engines that have become widespread in recent years, the cylinder head is often provided with a large-area intake / exhaust valve, and the thickness of the cylinder head tends to increase. It is located right above the sandwiched combustion chamber. In such an engine, since the plug disposing hole is designed deep in the cylinder head, the plug hole pipe is inevitably long in the axial direction, and the work of mounting the ignition plug becomes more complicated. Further, since it is necessary to perform two works, one for fixing the plug hole pipe to the cylinder head and one for installing the spark plug, there is a problem that the number of man-hours for the assembling work is large and the working time is long.

Therefore, an object of the present invention is to provide an ignition device for an internal combustion engine which can simplify the work of assembling the ignition plug and the plug hole pipe into the cylinder head.

[0008]

In order to achieve the above object, the present invention according to claim 1 provides a center electrode inserted into the tip end side of a shaft hole of an insulator and provided outside the insulator. A spark plug disposed in a plug disposing hole formed in a cylinder head of an internal combustion engine, the spark plug having a metal shell and a ground electrode coupled to the metal shell to form a spark discharge gap between the metal shell and the center electrode. An ignition device for an internal combustion engine, comprising: a spark discharge for igniting an air-fuel mixture in a spark discharge gap of the spark plug, which is directly or indirectly fixed to a cylinder head through another member. With a cylindrical plug hole pipe, the ignition plug is housed inside the plug hole pipe from its rear end side, and the plug hole pipe and the metal shell are fixed to each other,
It is characterized in that the spark plug and the plug hole pipe are integrally formed so as not to rotate in the axial direction.

In other words, in this ignition device for an internal combustion engine, the ignition plug and the plug hole pipe are fixed to each other so that they cannot rotate with respect to the axial direction (in other words, the ignition plug in the rotational direction about the axial direction). Since it is integrally formed (so that the relative position with the plug hole pipe is maintained constant), it is not necessary to perform the work of assembling to the cylinder head independently for the ignition plug and the plug hole pipe. Can be done with.

In order to integrally integrate the plug hole pipe and the spark plug so as not to rotate in the axial direction, for example, the metal shell of the spark plug and the plug hole pipe may be fixed to each other. Then, when integrating the spark plug and the plug hole pipe, the outer diameter of the plug hole pipe is set to be equal to or less than the maximum diameter in the direction orthogonal to the axial direction of the spark plug, and then both are set. It is desirable to integrate them. Conventionally, since the structure is such that the plug hole pipe is fixed to the cylinder head and then the spark plug is inserted therein, the inner diameter and the outer diameter of the plug hole pipe are the most in the direction orthogonal to the axial direction of the spark plug. The diameter had to be larger than the outer diameter.

On the other hand, in the structure in which the plug hole pipe and the spark plug are integrally fixed to each other in the axial direction so as not to rotate as in the present invention, both of them can be attached to the cylinder head at the same time as described above. The inner diameter can be set to the outer diameter which is the largest in the direction orthogonal to the axial direction of the spark plug or less, and by extension, the outer diameter of the plug hole pipe is set to be the outer diameter which is the largest or above. Is possible. By reducing the outer diameter of the plug hole pipe in this way, the area occupied by the plug hole pipe with respect to the cylinder head can be reduced compared to the conventional case, and the installation space for other devices such as the intake and exhaust valve mechanism can be reduced. Can be widely secured.

In the spark plug having the caulking portion in which the peripheral edge of the metal shell is caulked toward the outer peripheral portion of the insulator, in the spark plug, the plug hole pipe is one of the spark plugs. It is preferable that the rear end side portion of the metal shell relative to the caulking portion is housed inside, and that the caulking portion is fixed to the both to be integrated. With such a configuration, the outer diameter of the plug hole pipe can be reduced as much as possible, and the area occupied by the plug hole pipe with respect to the cylinder head can be further reduced.

As a method of fixing the metal shell of the ignition plug and the plug hole pipe, for example, welding such as laser welding, resistance welding, spot welding, electron beam welding, or brazing may be used. Further, as a fixing method in which the inner side surface of the plug hole pipe and the outer side surface of the metal shell of the ignition plug are in contact with each other, fixing by caulking is also possible.

Therefore, according to the ignition device for an internal combustion engine of the present invention (claim 1), the assembling work of the ignition plug and the plug hole pipe to the cylinder head can be simplified and the assembling work is complicated. It can be resolved. Further, it becomes possible to use a plug hole pipe having an outer diameter reduced as compared with the conventional one. Further, the area occupied by the plug hole pipe in the cylinder head can be reduced, and a large installation space for other devices such as the intake / exhaust valve drive mechanism can be secured.

By the way, in recent years, internal combustion engines in which the air-fuel ratio of the air-fuel mixture is set high (to a lean air-fuel ratio) have become widespread in order to meet the demands for higher efficiency and lower exhaust gas emissions. In such an internal combustion engine, the turbulent flow (swirl flow) of the air-fuel mixture in the combustion chamber is used to generate the air-fuel mixture suitable for combustion in the vicinity of the spark discharge gap of the spark plug to stabilize the ignitability. However, when generating a turbulent air-fuel mixture, it is known that the position of the ground electrode of the spark plug in the combustion chamber affects the ignitability of the air-fuel mixture. In other words, the air-fuel mixture is ignited by touching the sparks generated in the spark discharge gap of the spark plug.For example, when the ground electrode is located above the spark discharge gap with respect to the turbulent flow of the air-fuel mixture. In some cases, the ground electrode interferes with the air-fuel mixture, making it difficult for the air-fuel mixture to come into contact with sparks, which may reduce the ignitability of the air-fuel mixture.

Here, in a general spark plug, a thread groove (screw portion) for screwing into the cylinder head is formed in the metal shell. However, in the structure in which the metal plug is mounted on the cylinder head by screwing as described above, The arrangement position of the ground electrode in the combustion chamber varies depending on each spark plug. In addition, the spark plug that is attached to the cylinder head by screwing is
The position of the ground electrode in the combustion chamber at the time of final mounting will change due to slight dimensional errors and individual differences in the screw groove.

Therefore, in the above ignition device for an internal combustion engine (claim 1), as described in claim 2, the metal shell of the spark plug is directly connected to the cylinder head or indirectly through another member. A flange portion having a contacting plug seat surface on the tip side, and a tubular tip end extending axially from the plug seat surface of the collar portion to the tip end side in the axial direction without a thread groove being provided, It is preferable that the spark plug is housed in the plug hole pipe from the rear end side of the spark plug and the plug hole pipe and the rear end side of the metal shell of the metal shell are fixed to the rear end side.

The spark plug fixed to the plug hole pipe so as to be non-rotatable in the axial direction is not provided with a thread groove on the outer peripheral surface of the tip of the metal shell, and is attached to the cylinder head by screwing. It is not a structured structure. That is, since the tip of the metal shell does not have a thread groove on its outer circumference, it can be inserted into the cylinder head without being screwed. Therefore, when mounting the plug hole pipe and the spark plug, which are integrally configured on the cylinder head, the connection part of the ground electrode to the metal shell is specified in the circumferential direction around the axis (center axis) of the plug placement hole. It is easy to set the position. At this time, it goes without saying that the plug hole pipe is not structured to be attached to the cylinder head by screwing.

That is, after the direction of the turbulent flow of the air-fuel mixture is specified from the structure of the intake pipe and the combustion chamber, the arrangement position of the ground electrode in the combustion chamber is set. Then, considering the arrangement position, by mounting the integrated plug hole pipe and the ignition plug on the cylinder head, the arrangement position of the ground electrode in the combustion chamber is set to a specific position in consideration of the turbulent direction of the air-fuel mixture. It becomes possible to do.

Therefore, according to the ignition device for an internal combustion engine of the present invention (Claim 2), when the ignition device for an internal combustion engine in which the ignition plug and the plug hole pipe are integrated is finally attached, the ground electrode The arrangement position in the combustion chamber can be easily set to a specific position, and the ignitability of the air-fuel mixture can be excellently obtained.

In the structure in which the spark plug and the plug hole pipe having no thread groove in the metal shell are integrated, the internal structure of the internal combustion engine is not because the structure is not attached to the cylinder head (plug placement hole) by screwing. Even when the combustion pressure generated by the combustion of the air-fuel mixture is applied from the combustion chamber side during the operation of 1, it is necessary to be stably fixed to the cylinder head. In order to stably fix the integrally formed spark plug and plug hole pipe to the cylinder head, a pressure higher than the combustion pressure (specifically, 10 [MP
In a) or more), the metal shell may be fixed to the cylinder head so that the plug seating surface of the metal shell is pressed against the cylinder head.

Further, in the ignition device for an internal combustion engine according to (claim 2), as described in claim 3, at least one of the metal shell and the plug hole pipe of the ignition plug is fixed to the cylinder head by press fitting. It is good to be configured as described above.

That is, in the fixing method by press fitting, the integrated spark plug and plug hole pipe can be firmly fixed to the cylinder head, and even when the combustion pressure is applied from the combustion chamber side, It can be fixed stably.

When one of the integrated spark plug and plug hole pipe is fixed to the cylinder head by press fitting, the integrated spark plug and plug hole pipe can be removed from the cylinder head after fixing. It is difficult and the wearable internal combustion engine is limited to the internal combustion engine which does not require regular replacement of the spark plug.

Therefore, in the ignition device for an internal combustion engine of the above-mentioned (Claim 2), as described in Claim 4, one of the metal shell of the spark plug and the plug hole pipe is projected outward from the outer peripheral surface thereof. It is preferable that the ignition plug and the plug hole pipe integrally formed are fixed to the cylinder head by using the flange portion formed as described above.

That is, the structure in which the spark plug and the plug hole pipe which are integrally formed by using the flange portion are fixed to the cylinder head eliminates the need for a structure for press-fitting into the cylinder head. Then, after fixing the integrated spark plug and plug hole pipe by using the flange portion, by releasing the fixing by the flange portion, it becomes possible to remove them from the cylinder head again.

The flange portion may be formed, for example, at a plurality of locations by extending from different points on the outer peripheral surface of the plug hole pipe, or may be formed over the entire outer peripheral surface of the plug hole pipe. . And as a method of fixing the flange portion to the cylinder head, for example,
A method of forming a screw hole in the flange part and screwing a bolt into the screw hole to fix it to the cylinder head, or after inserting the plug hole pipe and the ignition plug integrated with the cylinder head, It is advisable to use a method in which an engaging portion that engages with the flange portion is formed on the cylinder head by rotating it around, and the both are fixed. At this time, the fixing position of the flange portion to the cylinder head and the arrangement position of the ground electrode in the combustion chamber when the plug hole pipe and the spark plug which are integrally configured are mounted are determined in consideration of the flow direction of the air-fuel mixture. By that,
The ground electrode can be arranged at a specific position in the combustion chamber simply by fixing the flange portion to a predetermined position of the cylinder head.

Further, in order to fix the spark plug and the plug hole pipe integrally formed to the cylinder head,
In the ignition device for an internal combustion engine according to the above (claim 2), as in claim 5, a cylindrical nut member having a through hole and having a thread groove formed on an outer peripheral surface thereof is provided. Is externally inserted from the rear end side to the spark plug and the plug hole pipe integrally formed in the through hole and is fixed to the cylinder head by screwing, and a part of itself is included in the spark plug and the plug hole pipe. It is preferable that the spark plug and the plug hole pipe that are integrally formed are fixed to the cylinder head by contacting at least one of them and pressing the plug seat surface of the metal shell of the spark plug against the cylinder head.

In the case of fixing the integrated spark plug and plug hole pipe by using the nut member as described above, it is not necessary to provide a structure for press-fitting the integrated both into the cylinder head. As a result, after mounting the integrated spark plug and plug hole pipe in the plug placement hole, fixing them to the cylinder head using the nut member, and then removing the nut member, remove them again from the cylinder head. Is possible.

When the nut member is fixed to the cylinder head, a part of the nut member comes into contact with at least one of the spark plug and the plug hole pipe, so that the plug seat surface of the metal shell of the spark plug is attached to the cylinder head. It is important that it is formed to press. This is because, even when the combustion pressure generated by the combustion of the air-fuel mixture is applied from the combustion chamber side, it is necessary to stably fix the spark plug and the plug hole pipe integrally configured to the cylinder head.

By the way, when mounting an ignition plug having a plug hole pipe and a metal shell having no thread groove integrally formed on a cylinder head, as described above, the connecting portion of the ground electrode to the metal shell is plugged. It is easy to set it at a specific position in the circumferential direction around the axis of the placement hole, but rotation occurs after inserting both into the plug placement hole until they are fixed, and the placement position of the ground electrode in the combustion chamber is It may change.

Therefore, in the above-mentioned ignition device for an internal combustion engine (any one of claims 2 to 5), as described in claim 6, the ignition plug and the plug hole pipe which are integrally formed are the cylinders. The metal shell is provided with a first detent portion that engages with the cylinder head at one or a plurality of points when it is mounted on the head and is rotated about the axial direction of the plug placement hole. Is the first
It is preferable to provide a first rotation stopper receiving portion corresponding to the rotation stopper portion. That is, when the spark plug and the plug hole pipe, which are integrally formed, are fixed to the cylinder head by providing the first rotation stopping portion and the first rotation preventing receiving portion,
The ignition device for an internal combustion engine is configured so that the connecting portion of the ground electrode to the metal shell is set at a predetermined position in the circumferential direction around the axis of the plug disposing hole.

Here, the first detent portion formed on the metal shell of the spark plug and the first detent receiving portion formed on the cylinder head are integrated by fitting or engaging with each other. It has the function of preventing rotation of the spark plug and the plug disposition hole of the plug hole pipe, and the function of specifying the disposition position of the ground electrode in the combustion chamber. And, as the first detent portion,
For example, it may be provided as a ridge extending in the axial direction on the outer peripheral surface of the metal shell of the spark plug or as a groove portion provided on the outer peripheral surface of the metal shell of the spark plug in the axial direction. In addition, the metal shell of the spark plug is formed with a specific cross-section whose cross-sectional shape in a plane perpendicular to the axial direction is a shape other than a circle (polygon (hexagon, etc.), ellipse, etc.). May be used as the first detent portion.

At this time, the cylinder head can be fitted (engaged) with the first anti-rotation part in consideration of the arrangement position of the ground electrode in the combustion chamber so as to have a good ignitability. It is necessary to provide such a first detent receiving portion. With this, only by fitting (engaging) the first detent portion with the first detent receiving portion formed on the cylinder head, it is possible to reliably and easily arrange the ground electrode in the combustion chamber with good ignitability. Can be set to a position.

When mounting an ignition plug having a plug hole pipe and a metal shell having no thread groove integrally formed on a cylinder head, the ignition plug integrally formed as described in claim 7. When the plug and the plug hole pipe are attached to the cylinder head, it is preferable that the plug hole pipe is formed with a position identifying portion that allows the connecting portion of the ground electrode to the metal shell to be identified from the outside.

As described above, by providing the position identifying portion on the plug hole pipe that allows the connecting portion of the ground electrode to the metal shell of the spark plug to be identified from the outside, the ground electrode can be reliably set at a specific position in the combustion chamber. It is possible to prevent the deterioration of ignitability. In other words, when inserting the integrated plug hole pipe and spark plug into the plug placement hole and fixing them to the cylinder head, while visually recognizing the position identifying part of the plug hole pipe, the position identifying part is located at the planned circumferential position. It becomes possible to set the ground electrode at a specific position in the combustion chamber by adjusting to. At this time, the position setting portion satisfies the positional relationship in the predetermined circumferential direction with the connecting portion of the ground electrode to the metal shell, and the outer peripheral surface of the plug hole pipe or the rear end surface (the side facing the spark plug). The end surface on the opposite side) must be formed on the inner peripheral surface.
Further, it is desirable that the position setting portion is formed in a portion of the plug hole pipe that can be easily visually recognized from the outside. As the position identification part, a mark having any shape or a processing mark (for example, a mark is intentionally made on the outer surface of the plug hole pipe) can be exemplified.

Further, in mounting the spark plug having the plug hole pipe integrally formed and the metallic shell having no thread groove on the cylinder head,
As described in, the spark plug and the plug hole pipe integrally formed with the cylinder head when mounted on the cylinder head and rotated about the axial direction of the plug disposing hole are located at one or a plurality of locations. While the plug hole pipe is provided with a second detent portion that fits with each other, the cylinder head is provided with a second detent receiving portion that corresponds to the second detent portion. The ignition device for an internal combustion engine is configured so that when the plug hole pipe is fixed to the cylinder head, the connecting portion of the ground electrode to the metal shell is set at a predetermined position in the circumferential direction around the axis of the plug placement hole. May be.

Here, the second detent portion formed on the plug hole pipe and the second detent receiving portion formed on the cylinder head are integrated with each other by fitting or engaging with each other. And the function to prevent rotation in the plug placement hole of the plug hole pipe,
In addition, it has a function of specifying the arrangement position of the ground electrode in the combustion chamber. The second detent portion can be provided as, for example, a ridge portion extending in the axial direction on the outer peripheral surface of the plug hole pipe or a groove portion provided on the outer peripheral surface of the plug hole pipe in the axial direction.

At this time, the cylinder head can be fitted (engaged) with the second anti-rotation portion in consideration of the arrangement position of the ground electrode in the combustion chamber having a good ignition property. It is necessary to provide such a second detent receiving portion. With this, only by fitting (engaging) the second detent portion with the second detent receiving portion formed on the cylinder head, the arrangement position of the ground electrode in the combustion chamber can be reliably and easily provided with good ignitability. Can be set to a position.

On the other hand, the plug hole pipe has been
It is arranged in an internal space formed between the cylinder head and the cylinder head cover together with other devices such as an intake / exhaust valve drive mechanism. The upper end of the plug hole pipe contacts the cylinder head cover via the oil seal member, thereby preventing the lubricating oil circulating in the internal space of the cylinder head and the cylinder head cover from leaking to the outside.

Therefore, in the above-mentioned ignition device for an internal combustion engine (any one of claims 1 to 8), as described in claim 9, the cylinder head cover provided on the upper part of the cylinder head is provided. It is preferable that the ignition plug and the plug hole pipe, which are integrally formed, be fixed to the cylinder head by being sandwiched between the head cover and the cylinder head.

That is, the cylinder head cover urges the plug hole pipe toward the cylinder head, thereby fixing the integrated spark plug and plug hole pipe to the cylinder head. At this time, the plug hole pipe and the spark plug are integrated so that the integrated spark plug and plug hole pipe are biased against the cylinder head by a biasing force larger than the combustion pressure generated by the combustion of the air-fuel mixture. It is advisable to properly set the dimensions of the cylinder head cover and the cylinder head. This allows
During operation of the internal combustion engine, the integrated spark plug and plug hole pipe can be stably fixed to the cylinder head.

Further, the plug hole pipe is originally for isolating the spark plug from the lubricating oil, but when it is formed so as to be integrally fixed to the spark plug, its structure becomes more complicated than the conventional structure. there is a possibility. Therefore, due to a dimensional error or the like, a gap may be formed between the plug hole pipe and the cylinder head, and the lubricating oil may easily permeate.

Therefore, in the ignition device for an internal combustion engine described above (any one of claims 1 to 9),
As described in (1), an oil seal member may be provided between the spark plug and the plug hole pipe that are integrally configured and the cylinder head. In other words, the oil seal member
For example, it is made of an elastically deformable material (rubber, etc.) and its cross-sectional shape is deformed depending on the gap created between the plug hole pipe and the cylinder head or between the spark plug and the cylinder head. Thus, the gap between the plug hole pipe and the cylinder head can be closed, and the permeation of the lubricating oil can be appropriately prevented.

The ignition device for an internal combustion engine according to any one of claims 1 to 10 is characterized in that
As described in 1, the gasket is provided outside the metal shell of the spark plug, and the spark plug and the cylinder head may be in contact with each other via the gasket.

That is, a gasket is provided at a position where the spark plug and the cylinder head come into contact with each other, for example, between the plug seat surface of the flange portion of the metal shell and the cylinder head in the spark plug. As a result, it is possible to prevent a gap from being generated between the spark plug and the cylinder head, more reliably maintain the airtightness of the combustion chamber, and maintain the performance (particularly heat resistance) of the spark plug.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (a) shows a cylinder head 51 in which a pipe-integrated spark plug 9 in which an ignition plug and a plug hole pipe provided in an internal combustion engine ignition device 1 according to the first embodiment are integrated so as not to rotate in an axial direction. FIG. 1B is an explanatory view showing a state in which the pipe-integrated spark plug 9, the cylinder head 51, and the cylinder head cover 5 are mounted over the cylinder head cover 53 and the cylinder head cover 53.
3 is a sectional view of FIG.

As shown in FIG. 1B, the pipe-integrated spark plug 9 includes a spark plug 11 and a plug hole pipe 3.
1 and the metal shell 19 of the spark plug 11
And the tip 31b of the plug hole pipe 31 are fixed by welding. Then, the pipe-integrated spark plug 9 is arranged between the cylinder head 51 and the cylinder head cover 53 in a state where a portion corresponding to the spark plug 11 is arranged in the plug arrangement hole 51 a provided in the cylinder head 51. .

In the space formed between the cylinder head 51 and the cylinder head cover 53, an intake / exhaust valve drive mechanism (FIG. 1 (a) and (Not shown in FIG. 1B)
Is provided, and lubricating oil for circulating the intake / exhaust valve drive mechanism smoothly is circulated.

The internal combustion engine ignition device 1 includes an ignition coil (not shown in FIGS. 1A and 1B) having a primary winding and a secondary winding, and an igniter (having a power switching element). 1 (a) and 1 (b) are omitted). Then, the igniter energizes and disconnects the primary winding to generate a high voltage for ignition in the secondary winding of the ignition coil, and this high voltage for ignition causes the pipe-integrated spark plug 9 (specifically, ignition spark). Plug 11)
Is applied to the spark plug 11, spark discharge is generated in the spark discharge gap g formed between the center electrode 17 of the spark plug 11 and the ground electrode 21.

The cylinder head 51 is provided with a plug placement hole 51a for placing a portion of the pipe-integrated spark plug 9 corresponding to the spark plug 11. In addition,
The plug placement hole 51a includes a step surface 51b that comes into contact with the spark plug 11 (specifically, a plug seat surface 23a of the collar portion 23 described later) or through another member (the gasket 71 in this embodiment) and a step surface. The first wall surface 51 provided on the side closer to the combustion chamber 55 than the side 51b (the lower side in FIG. 1B).
c, and the second wall surface 51d and the third wall surface 51e provided on the side closer to the cylinder head cover 53 than the step surface 51b (upper side in FIG. 1B).

Next, as shown in FIG. 1B, the spark plug 11 provided in the pipe-integrated spark plug 9 is provided at the tip end side (the lower side in FIG. 1B) of the shaft hole of the insulator 15. The inserted center electrode 17, a metal shell 19 provided outside the insulator 15, and one end that is connected to the metal shell 19 and the other end forms a spark discharge gap g with the center electrode 17 The electrode 21 and the rear end side of the shaft hole of the insulator 15 (see FIG.
And the center electrode 17
And a terminal electrode 13 electrically connected to.
In addition, the metal shell 19 has its rear end peripheral edge made of the insulator 15.
Is provided with a caulking portion 27 that is caulked toward the outer peripheral portion of the metal shell, and the caulking portion 27 engages with a metal fitting side engaging portion (not shown) formed inside the metal shell 19. The insulator 15 is prevented from being pulled out, and the insulator 15 is held by the metal shell 19.

Of these, the metal shell 19 has a cylinder head 51 (specifically, a step surface 51 of the plug placement hole 51a).
b) A flange portion 23 having a plug seat surface 23a on the tip side that comes into direct or other member contact (specifically, the gasket 71), and an axial tip end side extending from the plug seat surface 23a of the collar portion 23. The cylindrical outer peripheral surface is provided with a cylindrical tip portion 25 having no thread groove. Also, the collar part 2
A rear end surface 23b is formed on the side opposite to the plug seat surface 23a of No. 3.

The plug hole pipe 31 forming part of the pipe-integrated spark plug 9 is a cylindrical member made of a metal material such as stainless steel or aluminum.
The rear end 31a and the front end 31b are opened, and the spark plug 11 is externally inserted from the rear end side of the spark plug 11, and the rear end side (see FIG.
The upper side of the above) can be housed inside. The plug hole pipe 31 is formed such that its inner diameter is smaller than the outer diameter of the flange portion 23 of the metal shell 19 of the spark plug 11, and the outer diameter of the plug hole pipe 31 is different from that of the rear end 31a. It is formed smaller than the outer diameter of the collar portion 23. The tip 31b of the plug hole pipe 31 is formed so as to come into contact with the rear end surface 23b of the flange portion 23 of the ignition plug 11, and has an outer diameter smaller than that of a conventional plug hole pipe.

On the outer peripheral surface of the plug hole pipe 31 near the rear end side, as shown in FIG. 1 (a), the connecting portion of the ground electrode 21 of the spark plug 11 to the metal shell 19 is arranged in the circumferential direction. Predetermined positional relationship (angular positional relationship)
A mark m as a position identification portion is provided so as to satisfy the above condition.

In the pipe-integrated spark plug 9, the spark plug 11 is inserted into the plug hole pipe 31 and the tip 3 is attached.
1b is inserted from the opening, the tip end 31b of the plug hole pipe 31 is brought into contact with the rear end surface 23b of the collar portion 23 of the metal shell 19, and then the rear end surface 23b and the tip end 31b are fixed by welding. To be done. At this time, the plug hole pipe 31 and the spark plug 11 on which the mark m is formed have a circumferential position between the position where the mark m is formed and the position where the ground electrode 21 is connected to the metal shell 19 when viewed in the circumferential direction. Are fixed by welding so as to satisfy a predetermined positional relationship in the direction.

The pipe-integrated spark plug 9 thus constructed has a plug placement hole 51 in the cylinder head 51.
The side surface of the collar portion 23 of the ignition plug 11 and the side surface of the plug hole pipe 31 on the tip side are inserted into the plug a from the side of the spark plug 11 with respect to the second wall surface 51d of the plug placement hole 51a. It is press-fitted and fixed in.

When the pipe-integrated spark plug 9 is press-fitted into the plug arranging hole 51a, the gasket 71 causes the plug seat surface 23a of the collar portion 23 of the metal shell 19 and the step surface 51.
The oil seal 63 is sandwiched between b and b, and the oil seal 63 is arranged between the plug hole pipe 31 and the third wall surface 51e of the plug arrangement hole 51a. Further, the first wall surface 51c of the plug placement hole 51a faces the tip portion 25 of the spark plug 11.

Here, the oil seal 63 is a ring-shaped member made of an elastically deformable material having heat resistance, and is sandwiched between the plug hole pipe 31 and the third wall surface 51e and has a sectional shape. By deforming, the gap generated between the plug hole pipe 31 and the cylinder head 51 (specifically, the third wall surface 51e) is closed. Therefore, the oil seal 63 can prevent the lubricating oil from penetrating between the plug hole pipe 31 and the cylinder head 51. Further, the oil seal 63 is arranged so as to be fitted in a bottomed cylindrical recess (not shown) formed in the circumferential direction on the outer peripheral side surface of the plug hole pipe 31. When press-fitting into the plug placement hole 51a, the plug placement hole 51a is sandwiched between the third wall surface 51e while elastically deforming between the plug placement hole 51a and the third wall surface 51e. The oil seal 63 is not shown in FIG.

After that, the cylinder head cover 53 is fixed to the upper part of the cylinder head 51, so that the rear end 31a of the plug hole pipe 31 comes into contact with the peripheral portion of the opening 53a of the cylinder head cover 53. As a result, the pipe-integrated spark plug 9 is
As shown in (b), a portion corresponding to the spark plug 11 is arranged in the plug arrangement hole 51a of the cylinder head 51,
The plug hole pipe 31 is sandwiched between the cylinder head 51 and the cylinder head cover 53 while being in contact with the inner surface of the cylinder head cover 53.

The rear end 31 of the plug hole pipe 31
A second oil seal 64 (FIG. 1A and FIG. 1A) for preventing the penetration of the lubricating oil is provided between the enlarged portion of a and the peripheral portion of the opening 53a of the cylinder head cover 53.
(See (b)) is arranged. The second oil seal 64 prevents the lubricating oil from leaking between the rear end 31a of the plug hole pipe 31 and the cylinder head cover 53, and prevents the lubricating oil from leaking from the rear end 31a of the plug hole pipe 31.
It is prevented from invading from the outside and adhering to the spark plug 11.

Here, the pipe-integrated spark plug 9 of this embodiment has no thread groove on the outer peripheral surface of the tip portion 25 of the metal shell 19 of the spark plug 11, so that the method of fixing it to the cylinder head 51 is different. Since it is not a method by screwing, it is easy to set the connecting portion of the ground electrode 21 to the metal shell 19 at a specific position in the circumferential direction around the axis of the plug placement hole 51a. Since the tip portion 25 of the metal shell 19 does not have a thread groove on the outer circumference, the pipe integrated spark plug 9 can be inserted into the plug placement hole 51a of the cylinder head 51 without being screwed. Therefore, the pipe-integrated spark plug 9 can be easily attached.

Therefore, the mark m formed on the outer peripheral side surface of the plug hole pipe 31 is visually recognized in a state where the arrangement position of the ground electrode 21 in the combustion chamber 55 is set in advance, and the mark m is in the predetermined circumferential direction. By mounting the pipe-integrated spark plug 9 in the plug placement hole 51a so as to match the specific position of the pipe-integrated spark plug 9, the placement position of the ground electrode 21 in the combustion chamber 55 at the time of the final mounting Can be set to.

More specifically, after the direction of the turbulent flow (swirl flow) of the air-fuel mixture is specified from the structure of the intake pipe and the combustion chamber 55, the optimum arrangement position of the ground electrode 21 in the combustion chamber 55 is specified in advance. Then, the pipe-integrated spark plug 9 is attached to the cylinder head 51 while visually recognizing the mark m having a positional relationship in the predetermined circumferential direction with the connecting portion of the ground electrode 21 formed on the plug hole pipe 31 to the metal shell 19. By doing so, the arrangement position of the ground electrode 21 in the combustion chamber 55 can be set to a specific position in consideration of the direction of the turbulent flow of the air-fuel mixture. After mounting the pipe-integrated spark plug 9 on the cylinder head 51, the cylinder head cover 53 is fixed to the upper part of the cylinder head 51, and the pipe-integrated spark plug 9 is sandwiched between the cylinder head cover 53 and the cylinder head 51. Then, the pipe integrated spark plug 9 is fixed to the cylinder head 51.

As described above, in the internal combustion engine ignition device 1 according to the first embodiment, since the pipe-integrated ignition plug 9 is used, the work of assembling the cylinder head 51 can be performed only once. You can That is, the assembling work to the cylinder head 51 is performed by the spark plug 11
Since it is not necessary to separately perform the plug hole pipe 31 and the plug hole pipe 31, the fixing work to the cylinder head can be simplified, and the complexity of the fixing work can be eliminated.

The pipe-integrated spark plug 9 is sandwiched between the cylinder head 51 and the cylinder head cover 53 by being press-fitted into the plug disposing hole 51a of the cylinder head 51 so as to be sandwiched between the cylinder wall 51 and the cylinder head cover 53. ,
It is fixed to the cylinder head 51. That is, since the fixing method by screwing is not adopted as the fixing method of the pipe integrated spark plug 9, the ground electrode 21 of the metal shell 19 is not used.
It is easy to set the coupling part of the above-mentioned at a specific position in the circumferential direction around the axis of the plug placement hole 51a. In the internal combustion engine ignition device 1 of the present embodiment, the ground electrode 21 is arranged in the combustion chamber 55 so that the ignition property of the air-fuel mixture is particularly good. Good property is obtained.

Further, since the pipe-integrated spark plug 9 is clamped by the second wall surface 51d by being press-fitted into the plug disposing hole 51a, it is also clamped between the cylinder head 51 and the cylinder head cover 53. The pipe-integrated spark plug 9 is firmly attached to the cylinder head 51.
Will be fixed to. Therefore, the pipe-integrated spark plug 9 is securely fixed to the cylinder head 51 even when combustion pressure is generated by combustion of the air-fuel mixture.

Here, the pipe-integrated spark plug 9 has a plug hole so that the connecting portion of the ground electrode 21 to the metallic shell 19 is located at a specific position in the circumferential direction around the axis of the plug placement hole 51a. In addition to the configuration in which the mark m is provided on the pipe 31, any one of the second spark plug 11a, the third spark plug 11b, and the fourth spark plug 11c shown in FIG. 6 can be adopted.

First, the second spark plug 11a is provided on the outer peripheral side surface of the collar portion 23 of the metal shell 19 with a ridge 65 as a first rotation stopping portion extending in the axial direction. FIG. 6A shows an external view of the second spark plug 11a seen from the side, and FIG. 6B shows an external view of the second spark plug 11a seen from the tip side. Since the protrusion 65 is formed so that the relative position to the ground electrode 21 is constant as shown in FIG. 6B, the plug placement hole 5 of the cylinder head 51 is formed.
The second spark plug 11a and the plug hole pipe are integrally formed by providing the second wall surface 51d (see FIG. 1) of 1a with a fitting groove as a first anti-rotation receiving portion that can be fitted with the protruding portion 65. The integrated pipe-integrated spark plug is installed in the plug placement hole 5
The ridge 6 formed on the metal shell 19 while being inserted into 1a.
Only by fitting 5 into the fitting groove formed in the cylinder head 51, the arrangement position of the ground electrode 21 in the combustion chamber 55 can be maintained constant. At this time, the position of the fitting groove in the cylinder head 51 is further such that the connecting portion of the ground electrode 21 to the metal shell 19 is at a specific position in the circumferential direction around the axis of the plug placement hole 51a. 21 and connecting part to the metallic shell 19 and the ridge 65
It is set in advance in consideration of the positional relationship with.

Further, as can be seen from FIG. 6 (b), in the second spark plug 11a, among the circumferential positions on the outer peripheral surface of the collar portion 23 of the metallic shell 19, the installation position of the protruding portion 65 is the ground electrode. The position is the same as the position of the connecting portion 21 of the metal shell 21 to the metal shell 19. However, the installation position of the protruding portion 65 in the circumferential direction of the collar portion 23 is set at the metal shell 19 of the ground electrode 21.
It is not limited to the same position as the position of the connecting portion to. However, at this time, the position of the fitting groove formed on the cylinder head 51 side is, as described above, the metal shell 1 of the ground electrode 21.
It is necessary to appropriately set in consideration of the positional relationship between the connecting portion to 9 and the protruding portion 65 and the specific positional relationship of the ground electrode 21 in the combustion chamber 55. The ridge 65 is formed on the outer peripheral surface of the collar portion 23 of the metal shell 19 in the second spark plug 11a, but may be formed on the outer periphery of the tip portion 25 of the metal shell 19. At this time, on the cylinder head 51 side, a fitting groove may be appropriately formed on the first wall surface 51c of the plug placement hole 51a so as to correspond to the protruding portion formed on the tip portion 25 thereof.

Further, the third spark plug 11b is provided with a groove portion 67 as a first rotation stopping portion extending in the axial direction on the side surface of the collar portion 23 of the metal shell 19. FIG. 6C shows an external view of the third spark plug 11b viewed from the side.
(D) shows an external view of the third spark plug 11b as viewed from the tip side. Since the groove portion 67 is formed so that the relative position with respect to the ground electrode 21 is constant as shown in FIG. 6D, the groove portion 67 can be fitted into the plug arrangement hole of the cylinder head. By providing the fitting protrusion as the rotation-stop receiving portion, the pipe-integrated spark plug in which the third spark plug 11b and the plug hole pipe are integrated is formed in the metal shell 19 while being inserted into the plug placement hole 51a. By simply fitting the groove portion 67 to the fitting protrusion formed on the cylinder head 51, the arrangement position of the ground electrode 21 in the combustion chamber 55 can be maintained constant. At this time, at the position of the fitting protrusion in the cylinder head 51, the connecting portion of the ground electrode 21 to the metal shell 19 is the plug placement hole 5
It is set in advance so as to be located at a specific position in the circumferential direction around the axis of 1a in consideration of the positional relationship between the connecting portion of the ground electrode 21 to the metal shell 19 and the groove portion 67.

As can be seen from FIG. 6 (d), in the third spark plug 11b, among the circumferential positions on the outer peripheral surface of the collar portion 23 of the metallic shell 19, the installation position of the groove portion 67 is
The position is the same as the position where the ground electrode 21 is connected to the metal shell 19. However, the installation position of the groove portion 67 at the circumferential position of the collar portion 23 is not limited to the same position as the connecting portion position of the ground electrode 21 to the metal shell 19. However, the position of the fitting protrusion formed on the cylinder head 51 side at this time is, as described above, the positional relationship between the connecting portion of the ground electrode 21 to the metal shell 19 and the groove 67, and the inside of the combustion chamber 55. It is necessary to set it appropriately considering the specific positional relationship of the ground electrode 21. It should be noted that this groove portion 67 is the third
Although the spark plug 11b is formed on the outer peripheral surface of the collar portion 23 of the metal shell 19, it may be formed on the outer periphery of the tip portion 25 of the metal shell 19. At this time, on the cylinder head 51 side, in order to correspond to the groove formed in the tip portion 25,
A fitting protrusion may be appropriately formed on the first wall surface 51c of the plug placement hole 51a.

Further, the fourth spark plug 11c is provided with a flat surface portion 69 as a first rotation stopping portion on a part of the outer peripheral surface of the collar portion 23 of the metal shell 19. FIG. 6 (e) shows an external view of the fourth spark plug 11c seen from the side, and FIG.
The external view of the 4th ignition plug 11c seen from the front end side is shown in FIG. The plane portion 69 is formed so that the relative position with respect to the ground electrode 21 is constant as shown in FIG. 5 (f), so that the plug placement hole 51a of the cylinder head 51 is formed.
The flat surface portion 69 so that the flat surface portion 69 can be fitted.
The flat surface portion 6 of the pipe-integrated spark plug in which the fourth spark plug 11c and the plug hole pipe are integrated by providing the facing flat surface portion as the first anti-rotation receiving portion facing the
The position of the ground electrode 21 in the combustion chamber 55 can be kept constant only by fitting the plug 9 into the opposing flat surface of the plug placement hole 51a. At this time, at the position of the opposing flat surface portion formed on the cylinder head 51, the connecting portion of the ground electrode 21 to the metal shell 19 is the plug placement hole 51a.
It is set in advance so that it is located at a specific position in the circumferential direction around the axis line of (1) in consideration of the positional relationship between the ground electrode 21 and the plane portion 69.

As can be seen from FIG. 6 (f), in the fourth spark plug 11c, among the circumferential positions on the outer peripheral surface of the collar portion 23 of the metallic shell 19, the formation position of the plane portion 69 is the ground electrode 21. The position is the same as the position of the connecting part to the metal shell 19. However, the installation position of the flat surface portion 69 at the circumferential position of the collar portion 23 is not limited to the same position as the connection portion position of the ground electrode 21 to the metal shell 19. However, at this time, the position of the corresponding flat surface portion formed on the cylinder head 51 side is determined by the positional relationship between the connecting portion of the ground electrode 21 to the metal shell 19 and the flat surface portion 69, and the identification of the ground electrode 21 in the combustion chamber 55. It is necessary to set it appropriately considering the positional relationship.

Further, in the fourth spark plug 11c, the cross-sectional shape of the collar portion 23 of the metal shell 19 (the cross-sectional shape in a plane perpendicular to the axial direction of the fourth spark plug 11c) is obtained by cutting off a part of a circle. However, the cross-sectional shape of the collar portion 23 may be formed in a shape other than a circle, such as a polygon (hexagon, etc.) or an ellipse. The cross-sectional shape of the corresponding portion of the plug placement hole 51a of the cylinder head 51 is configured to allow the collar portion 23 of the spark plug to be placed, so that the placement position of the ground electrode 21 in the combustion chamber 55 can be reliably and easily performed. Can be set to a specific position.

Further, in the pipe-integrated spark plug 9, instead of the plug hole pipe 31, as shown in FIG. 7A, the relative position of the ground electrode 21 with respect to the cylinder head 51 can be surely set. , A ridge plug hole pipe 3 having a ridge 32c as a second detent
2 may be used.

7 (a) is a sectional view of the cylinder head 51 to which the pipe-integrated spark plug 9 constructed by using the projecting plug hole pipe 32 is mounted.
FIG. 7B is a cross-sectional view taken along the line AA of the pipe integrated spark plug 9 and the cylinder head 51 in FIG.

The protruding plug hole pipe 32 has a tip 32.
It is provided with a ridge 32c which is connected to the outer peripheral surface near b and projects outward from the outer peripheral surface.
Is fixed integrally with the ignition plug 11 in a state where the positional relationship between the ground electrode 21 and the connecting portion of the ground electrode 21 to the metal shell 19 in the circumferential direction is constant.

Thus, the ridge plug hole pipe 32
In the pipe-integrated spark plug 9 configured by using the cylinder head 51, the positional relationship in the circumferential direction between the protrusion 32c and the connecting portion of the ground electrode 21 to the metal shell 19 is constant.
The fitting position of the ground electrode 21 in the combustion chamber 55 is kept constant by providing the plug placement hole 51a with a fitting groove 51i as a second anti-rotation receiving part capable of fitting with the protrusion 32c. You can The cylinder head 51
The position of the fitting groove 51i is in the connecting portion of the ground electrode 21 to the metal shell 19 and the protruding portion 3 of the protruding plug hole pipe.
2c and the specific positional relationship of the ground electrode 21 in the combustion chamber 55 need to be set appropriately.

Further, the plug hole pipe 31 is formed such that the outer peripheral shape when the cross section in the direction orthogonal to the axial direction is taken is a shape other than a circle such as a polygon (hexagon, etc.) or an ellipse (in this case, The outer peripheral shape itself may correspond to the second detent portion, and the relative position of the ground electrode 21 with respect to the cylinder head in the pipe-integrated spark plug may be settable.

In the ignition device for an internal combustion engine of the first embodiment, the pipe-integrated ignition plug 9 is press-fitted and fixed to the second wall surface 51d of the plug placement hole 51a.
As shown in FIG. 5, it may be configured to be press-fitted and fixed to the first wall surface 51c of the plug placement hole 51a. Specifically, the tip portion 25 of the metal shell 19 of the spark plug 11 has the plug placement hole 5
The pipe-integrated spark plug 9 is fixed to the cylinder head 51 by being press-fitted and fixed to the first wall surface 51c of 1a. In this case, as shown in FIG.
The groove 23c is provided all around the outer circumference of the collar portion 23 of the metal shell 19 in FIG. 1, and the oil seal 63 is arranged in this groove 23c to prevent the lubricating oil from entering the tip portion 25 of the spark plug 11 or the like. be able to.

Next, as a second embodiment, the flange portion 75
An ignition device for an internal combustion engine including a second pipe-integrated spark plug 9a formed by using a second plug hole pipe 73 provided with will be described. The spark plug provided in the second pipe integrated spark plug 9a has the same structure as the spark plug 11 of the first embodiment.

FIG. 3 is a sectional view of the cylinder head 51 in which the second plug hole type pipe 73 having the flange portion 75 and the second pipe integrated type ignition plug 9a composed of the ignition plug 11 are arranged. In FIG. 3, the second plug hole pipe 73 is also shown as a sectional view.

As shown in FIG. 3, the cylinder head 51 is provided with an intake valve 57 and an exhaust valve 59, and a cam for driving the intake valve 57 and the exhaust valve 59 is provided above the cylinder head 51. An intake / exhaust valve drive mechanism including a shaft 61 and the like is provided, and lubricating oil for circulating the intake / exhaust valve drive mechanism is circulated.

As shown in FIG. 3, the second plug hole pipe 73 has a flange portion 75 formed so as to project radially outward from the outer peripheral surface thereof.
A through hole 75a through which the bolt 77 can be inserted is provided in the. The flange portion 75 may be formed so as to project outward over the entire outer circumference of the second plug hole pipe 73 as in this embodiment, or may be intermittently formed over the entire outer circumference. In addition, a plurality of outwardly protruding portions may be formed at equal intervals. Then, the front end 73b of the second plug hole pipe 73 and the rear end surface 23b of the flange portion 23 of the metal shell of the spark plug 11 are integrally fixed by welding in a non-rotatable manner in the axial direction. The body spark plug 9a is configured.

At this time, the length from the tip 73b of the second plug hole pipe 73 to the tip of the flange portion 75 is at least ignited when the second pipe integrated spark plug 9a is inserted into the plug disposing hole 51a. The plug seat surface 23a of the flange portion 23 of the metal shell 19 of the plug 11 is set so as to be able to contact the step surface 51b via the gasket 71. Thus, when the flange portion 75 is fixed to the cylinder head 51, the second pipe integrated spark plug 9a (specifically, the plug seat surface 23a) and the cylinder head 51 (specifically, the step surface of the plug placement hole 51a). 51
b) can be reliably brought into contact with each other via the gasket 71.

The flange portion 75 of the second plug hole pipe 73 has the through hole 75a for the cylinder head 5
It is fixed to the cylinder head 51 by a bolt 77 that is screwed and fixed to 1, and the cylinder head 51 is formed with a female screw portion 51g that can be screwed into the bolt 77. The position where the female screw portion 51g is formed on the cylinder head 51 is the second pipe integrated spark plug 9a.
Is fixed to the cylinder head 51, the ground electrode 21 is set at a specific position in the combustion chamber 55 that is set in consideration of ignitability.

Further, of the outer peripheral surface of the second plug hole pipe 73, the outer peripheral surface between the flange portion 75 and the tip 73b, and the second of the plug disposing holes 51a of the cylinder head 51.
An oil seal 63 is arranged between the wall surface 51d and
The lubricant is prevented from entering the ground electrode 21 and the like of the spark plug 11. The plug placement hole 51a of the cylinder head 51 of the second embodiment has a step surface 51b and a first wall surface 51c.
And the second wall surface 51d is provided, but unlike the plug placement hole 51a of the first embodiment, the third wall surface is not provided.
The oil seal 63 has a bottomed recess 7 formed in the circumferential direction on the outer peripheral surface of the second plug hole pipe 73.
When the second plug hole pipe 73 is fixed to the cylinder head 51 by the flange portion 75, the second wall surface 51d of the plug arranging hole 51a is arranged so as to be fitted into the cylinder 3c.
While being elastically deformed between and, it is sandwiched between the second wall surface 51d.

As explained above, in the ignition device for an internal combustion engine of the second embodiment, the second plug hole pipe 73 is fixed to the cylinder head 51 by fixing the flange portion 75 with the bolt 77. Therefore, by removing the bolt 77, the fixed second plug hole pipe 73 (second pipe integrated spark plug 9a) can be removed from the cylinder head 51.

Therefore, according to the internal combustion engine ignition device of the second embodiment, as in the internal combustion engine ignition device of the first embodiment, the cylinder head 5 of the second pipe-integrated spark plug 9a is used.
It is possible to set the position of the ground electrode 21 in the combustion chamber 55 at the time of mounting to the No. 1 to a position that provides the optimum ignitability, and it is possible to replace the second pipe integrated spark plug 9a. Can be applied to.

Further, as a third embodiment, a third pipe integrated spark plug 9b formed by using a third plug hole pipe 89 having a small flange portion 91, and a third pipe integrated spark plug 9b are used as a cylinder head. An ignition device for an internal combustion engine including a cylindrical fixing member 87 for fixing to 51 will be described. The spark plug provided in the third pipe integrated spark plug 9b has the same configuration as the spark plug 11 of the first embodiment. Further, the intake / exhaust valve drive mechanism provided in the cylinder head 51 has the same configuration as that of the second embodiment, and therefore the description thereof is omitted here.

A sectional view of the cylinder head 51 in a state where the third pipe-integrated spark plug 9b composed of the third plug hole pipe 89 and the spark plug 11 is fixed by a cylindrical fixing member 87 as a nut member. Is shown in FIG. In addition, in FIG. 4, the cylindrical fixing member 87 is also shown as a cross-sectional view.

First, the cylindrical fixing member 87 has the third inner diameter.
The plug hole pipe 89 is sized to be inserted through the cylindrical portion, and is formed in a tubular shape having a thread groove 87c on the outer peripheral surface. Further, the third plug hole pipe 89 is provided with a small flange portion 91 protruding outward in the radial direction near the tip 89b as shown in FIG. The outer diameter of the rear end 89a of the third plug hole pipe 89 is the same as that of the cylindrical portion.
It is formed in a size that can be inserted inside. In addition, in FIG. 4, the intermediate portion in the axial direction of the third plug hole pipe 89 is omitted.

Further, on the second wall surface 51d of the plug disposing hole 51a of the cylinder head 51, there is formed a screw groove 51h which can be screwed in correspondence with the screw groove 87c of the cylindrical fixing member 87. And the third pipe integrated spark plug 9b
Is inserted into the plug placement hole 51a of the cylinder head 51, the cylindrical fixing member 87 is inserted from the rear end 89a into the third plug hole pipe 89, and the screw groove 87c and the screw groove 51h are inserted.
The cylindrical fixing member 87 is attached to the cylinder head 5 by screwing with
Fixed to 1. At this time, the cylindrical fixing member 87 is fixed to the cylinder head 51 by screwing, and abuts against the small flange portion 91 at its axial end 87b,
The third plug hole pipe 89 is biased to the cylinder head 51. Thus, the third plug hole pipe 89 is biased by the cylindrical fixing member 87, so that the third pipe integrated spark plug 9 b is fixed to the cylinder head 51.

When such a cylindrical fixing member 87 is used, the small flange portion 91 has the cylindrical fixing member 8
If it is formed in such a size that it can be brought into contact with the tip end 87b of No. 7, it can be fixed to the cylinder head 51. From this, for example, the size of the flange portion (specifically, the size of the portion extending in the radial direction from the outer surface of the plug hole pipe) can be reduced as compared with the case of using a bolt. Therefore, according to the ignition device for an internal combustion engine of the third embodiment, since the flange portion can be downsized, it is possible to secure a wide installation space for other devices above the cylinder head 51.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments.
Various aspects can be taken. For example, in the above embodiment, as the plug hole pipe having the flange portion, the plug hole pipe in which the flange portion is formed over the entire outer circumference like the second plug hole pipe 73 and the third plug hole pipe 89 has been described. A fourth plug hole pipe 93 in which two divided flange portions 93c as shown in FIG. 5 are intermittently provided in the circumferential direction may be used. Then, FIG. 5A shows a cross-sectional view of the cylinder head 51 to which the fourth pipe integrated spark plug 9c configured by using the fourth plug hole pipe 93 is mounted.

As shown in FIG. 5A, the fourth plug hole pipe 93 is provided with two divided flange portions 93c, and a fourth pipe integrated type formed by using the fourth plug hole pipe 93 is formed. The spark plug 9c has an engaging portion 85.
Is fixed to a cylinder head 51 having The engaging portion 85 is formed so as to extend upward from the upper surface of the cylinder head 51 and to have a contact portion with the insertion fixing member 83 disposed between the split flange portion 93c. There is.

Here, the fourth pipe integrated spark plug 9c
FIG. 5B is a schematic view showing a state in which the insertion fixing member 83 is inserted between the insertion fixing member 83 and the engaging portion 85 of the cylinder head 51. Note that FIG. 5B shows the fourth pipe integrated spark plug 9 when looking down from above the cylinder head 51.
c, the engaging portion 85 of the cylinder head 51 and the insertion fixing member 83 are schematically shown.

The fourth pipe integrated spark plug 9c
To fix the cylinder to the cylinder head 51, first, the split flange portion 93c is inserted into the plug placement hole 51a without interfering with the engaging portion 85. Then, the split flange portion 93c
The fourth pipe-integrated spark plug 9c is rotated so that the and the engaging portion 85 come closest to each other, and the insertion fixing member 83 is inserted between the split flange portion 93c and the engaging portion 85. As a result, the engaging portion 85 and the insertion fixing member 83 prevent the split flange portion 93c from coming out of the plug disposing hole 51a, and the fourth pipe integrated spark plug 9c.
Can be fixed to the cylinder head 51.

Incidentally, the engaging portion 85 and the divided flange portion 9
3c may be configured to be in contact with each other even when the insertion fixing member 83 does not exist. In this case, by inserting the fourth pipe integrated spark plug 9c into the plug placement hole 51a in a state where the split flange portion 93c and the engagement portion 85 do not interfere with each other, the fourth pipe integrated spark plug 9c is rotated, The split flange portion 93c and the engaging portion 85 come into contact with each other, so that the fourth pipe integrated spark plug 9c is fixed to the cylinder head 51.

In the ignition device for an internal combustion engine, the pipe-integrated spark plug may be fixed to the cylinder head only with the cylinder head cover. In this case, the pipe-integrated spark plug is fixed to the cylinder head. There is no need to add a new member. As a result, an increase in the number of parts can be suppressed, and manufacturing cost can be suppressed.

Further, the fixing position of the plug hole pipe and the ignition plug is not limited to the tip of the plug hole pipe and the rear end surface of the brim portion of the metal shell, but the inner surface of the plug hole pipe and the side surface of the brim portion of the metal shell. And the inside of the plug hole pipe and the caulking part of the metal shell, and the caulking part of the metal shell, and the inside protrusion formed to project inward in the radial direction at the tip of the plug hole pipe and the metal shell It may be a crimp part.

The plug-hole pipe constituting the pipe-integrated spark plug is of a type having a portion having an enlarged diameter portion at its rear end and having a constant outer diameter in the other portions, or having a constant outer diameter in all portions. The type is not limited to the type having a diameter, and a type in which the outer diameter changes in the middle part in the axial direction may be used.

[Brief description of drawings]

FIG. 1A is an explanatory diagram showing a state where a pipe-integrated spark plug included in an internal combustion engine ignition device according to a first embodiment is mounted between a cylinder head and a cylinder head cover; FIG. 6B is a sectional view of the pipe-integrated spark plug, the cylinder head, and the cylinder head cover after mounting.

FIG. 2 is a cross-sectional view of a cylinder head in which a pipe-integrated ignition plug in which a tip portion of a metal shell is press-fitted and fixed to a first wall surface of a plug placement hole is placed.

FIG. 3 is a cross-sectional view of the cylinder head in a state in which a second plug-integrated spark plug including a second plug hole pipe having a flange portion and a spark plug is arranged.

FIG. 4 is a cross-sectional view of a cylinder head in which a third pipe-integrated spark plug is fixed by a cylindrical fixing member.

5A is a sectional view of a cylinder head in which a fourth pipe-integrated spark plug is fixed by an insertion fixing member, and FIG. 5B is an engagement between the fourth pipe-integrated spark plug and the cylinder head. It is a schematic diagram showing the state which inserts an insertion fixing member between a part.

6A is an external view of the second spark plug seen from the side, FIG. 6B is an external view of the second spark plug seen from the tip side, and FIG. 6C is a view seen from the side. 3D is an external view of the third spark plug, FIG. 3D is an external view of the third spark plug viewed from the tip side, and FIG. 3E is an external view of the fourth spark plug viewed from the side. f) is an external view of the fourth spark plug viewed from the tip side.

FIG. 7A is a cross-sectional view of a cylinder head equipped with a pipe-integrated spark plug configured by using a ridged plug hole pipe, and FIG. 7B is a pipe-integrated spark plug in FIG. 7A. FIG. 3 is a cross-sectional view of the cylinder head as seen from AA.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine ignition device, 9 ... Pipe integrated spark plug, 9a ... 2nd pipe integrated spark plug, 9b ... 3rd pipe integrated spark plug, 9c ... 4th pipe integrated spark plug, 11 ... Spark plug , 13 ... Terminal electrode, 15 ... Insulator, 17 ... Center electrode, 19 ... Metal shell, 21 ... Ground electrode, 23 ... Collar part, 31 ... Plug hole pipe, 51 ... Cylinder head, 51a ... Plug placement hole, 53 ... Cylinder head cover, 63 ... Oil seal, 64 ... Second oil seal, 71 ... Gasket, 73 ... Second plug hole pipe, 75 ... Flange portion, 87 ... Cylindrical fixing member, 89
… Third plug hole pipe, 91… Small flange part, 9
3 ... 4th plug hole pipe, m ... mark (position identification part).

Claims (11)

[Claims] 1. A spark is formed between a center electrode inserted into the tip side of a shaft hole of an insulator, a metal shell provided outside the insulator, and the center electrode coupled to the metal shell. A spark plug having a ground electrode forming a discharge gap and arranged in a plug arrangement hole formed in a cylinder head of an internal combustion engine, and spark discharge for igniting an air-fuel mixture is generated in the spark plug. An ignition device for an internal combustion engine that is generated in a spark discharge gap, comprising a cylindrical plug hole pipe fixed directly or indirectly through another member to the cylinder head, wherein the ignition plug is its own. The plug hole pipe is accommodated in the inside of the plug hole pipe from the rear end side, and the plug hole pipe and the metal shell are fixed to each other so that the ignition plug and the plug hole pipe are axially opposed to each other. Nonrotatably it is configured integrally Te, ignition apparatus according to claim. 2. The ignition device for an internal combustion engine according to claim 1, wherein the metal shell of the spark plug has a plug seat surface that directly contacts the cylinder head or indirectly through another member. And a tubular tip end portion that extends axially from the plug seating surface of the collar end to the tip end side in the axial direction and is not provided with a thread groove on the outer periphery thereof. For the internal combustion engine, wherein the plug hole pipe is housed in the inside of the plug hole pipe from the rear end side and the plug hole pipe and the rear end side of the metal shell are fixed to the rear end side. Ignition device. 3. The ignition device for an internal combustion engine according to claim 2, wherein at least one of the metal shell and the plug hole pipe of the spark plug is fixed to the cylinder head by press fitting. An ignition device for an internal combustion engine, comprising: 4. The ignition device for an internal combustion engine according to claim 2, wherein one of the metal shell of the spark plug and the plug hole pipe is formed with a flange portion protruding outward from an outer peripheral surface thereof. An ignition device for an internal combustion engine, comprising: the ignition plug and the plug hole pipe, which are integrally formed, are fixed to the cylinder head by using the flange portion. 5. The ignition device for an internal combustion engine according to claim 2, further comprising a tubular nut member having a through hole and having a thread groove formed on an outer peripheral surface thereof, wherein the nut member comprises: The ignition plug and the plug hole pipe integrally formed in the through hole are externally inserted from the rear end side and fixed to the cylinder head by screwing, and a part of the ignition plug and the ignition plug and the plug hole pipe. By pressing at least one of the plug hole pipes and pressing the plug seating surface of the metal shell of the spark plug against the cylinder head, the spark plug and the plug hole pipe that are integrally formed are connected to the cylinder head. An ignition device for an internal combustion engine, which is fixed. 6. The ignition device for an internal combustion engine according to claim 2, wherein the ignition plug and the plug hole pipe that are integrally formed are mounted on the cylinder head. In addition, the metal shell is provided with a first anti-rotation portion that engages with the cylinder head at one or a plurality of locations when the metal shell is rotated about the axial direction of the plug placement hole, while the cylinder head is A first rotation-stop receiving portion corresponding to the first rotation-stop portion, and when the spark plug and the plug hole pipe that are integrally configured are fixed to the cylinder head, The ignition device for an internal combustion engine, wherein the coupling portion of the ground electrode is set at a predetermined position in the circumferential direction around the axis of the plug disposing hole. 7. The ignition device for an internal combustion engine according to claim 2, wherein the ignition plug and the plug hole pipe that are integrally formed are mounted on the cylinder head. An ignition device for an internal combustion engine, characterized in that a position identification portion that allows the connection portion of the ground electrode to the metal shell to be identified from the outside is formed on the plug hole pipe. 8. The ignition device for an internal combustion engine according to claim 2, wherein the ignition plug and the plug hole pipe that are integrally formed are connected to the cylinder head. The plug hole pipe is provided with a second detent portion that engages with the cylinder head at one or a plurality of points when the plug hole is rotated around the axial direction of the plug disposing hole during mounting. The cylinder head includes a second detent receiving portion corresponding to the second detent portion, and when the ignition plug and the plug hole pipe integrally configured are fixed to the cylinder head, the metal shell is attached. An ignition device for an internal combustion engine, wherein a connecting portion of the ground electrode to the ground electrode is set at a predetermined position in a circumferential direction around an axis of the plug disposing hole. 9. The ignition device for an internal combustion engine according to claim 1, further comprising a cylinder head cover provided on an upper portion of the cylinder head, the cylinder head cover and the cylinder head. The ignition device for an internal combustion engine, wherein the ignition plug and the plug hole pipe that are integrally formed are fixed to the cylinder head by being sandwiched between them. 10. The ignition device for an internal combustion engine according to claim 1, wherein the ignition plug and the plug hole pipe and the cylinder head are integrally configured. An ignition device for an internal combustion engine, comprising: an oil seal member. 11. The method according to any one of claims 1 to 10.
The ignition device for an internal combustion engine according to the item, wherein a gasket is provided outside the metal shell of the ignition plug, and the ignition plug and the cylinder head are in contact with each other via the gasket, A characteristic ignition device for an internal combustion engine.