JP3498385B2 - Ignition device for internal combustion engine - Google Patents

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, and more particularly to an ignition device for an internal combustion engine which improves the assemblability of an ignition coil.

[0002]

2. Description of the Related Art Conventionally, an internal combustion engine (hereinafter referred to as "engine")
There is an ignition device for an internal combustion engine in which a spark plug is embedded in a plug hole formed in a cylinder head and power is directly supplied to the spark plug. In the method of fixing the ignition device for an internal combustion engine of this kind to the engine, after the lower end portion of the ignition device for an internal combustion engine inserted in the plug hole is fitted to the ignition plug, it is provided at the upper end portion of the ignition device for an internal combustion engine. At one place of the supporting portion, it is fastened and fixed to the cylinder head with a bolt through a cylindrical spacer. Therefore, when fixing the bolt, the axis of the plug hole and the axis of the ignition device for the internal combustion engine need to be substantially parallel to each other, and the lower end surface of the bolt head, the upper and lower end surfaces of the spacer, and the cylinder head that come into contact when fixing the bolt. The upper end surface is processed so that the surfaces are kept parallel to each other.

[0003]

However, according to such a conventional ignition device for an internal combustion engine, the lower end surface of the bolt head, the upper and lower end surfaces of the spacer, and the upper end surface of the cylinder head are kept parallel to each other. As described above, there is a problem in that the cost is increased because it needs to be processed with high precision.

On the other hand, if a machining error occurs in any of the lower end face of the bolt head, the upper and lower end faces of the spacer, and the upper end face of the cylinder head, the respective faces cannot be kept parallel to each other. The ignition device for the internal combustion engine inserted in the plug hole tilts with respect to the axis of the plug hole. Then, when an internal combustion engine ignition device having an axial length longer than the outer diameter is attached to the plug hole, the lower end of the internal combustion engine ignition device is inclined so as to approach the inner wall of the plug hole. A radial force is applied to the fitting portion between the lower end portion and the spark plug. As a result, the high-voltage sealing characteristic of the insulating member that wraps around the fitting portion may be deteriorated, and the internal combustion engine ignition device and the ignition plug may be damaged by the great mechanical stress generated in the fitting portion. There is a risk.

Further, when the bolts are completely tightened in a state where the upper and lower end surfaces of the spacer are inclined with respect to the lower end surface of the bolt head and the upper end surface of the cylinder head, the shaft required for fixing the ignition device for the internal combustion engine There is a problem that sufficient directional force cannot be obtained. The present invention has been made to solve such a problem, and provides an ignition device for an internal combustion engine that relieves mechanical stress generated in a fitting portion between the ignition device for an internal combustion engine and an ignition plug when a bolt is fastened. The purpose is to do.

[0006]

In order to solve the above-mentioned problems, an ignition device for an internal combustion engine according to claim 1 of the present invention has one end which can be fitted into an ignition plug embedded in a recess of a cylinder head. part have a, the coil body than the outer diameter
The spark plug is formed into a cylindrical shape with a long axial length.
Built-in high voltage generator that generates high voltage for supply
The plug hole formed in the cylinder head
A coil main body to be inserted into the cylinder main body, a fixing portion formed at the other end of the coil main body and fixing the coil main body to the cylinder head with a bolt, and interposed between the fixing portion and the cylinder head. And a spacer having a through hole through which the bolt penetrates, the upper and lower end surfaces of which are formed so as to project from the fixing portion, and which comes into contact with the upper end surface of the spacer that contacts the head of the bolt or the cylinder head. At least one of the lower end surfaces of the spacers is formed into a convex curved surface.

[0007] The ignition apparatus for an internal combustion engine according to claim 2, wherein according to the invention have a one end that can be fitted to the spark plug which is embedded in the recess of the cylinder head, the coil
The main body is formed into a cylindrical shape whose axial length is longer than the outer diameter,
A high voltage that generates a high voltage to supply the spark plug.
It has a built-in pressure generator and is formed on the cylinder head.
A coil body inserted into a plug hole, and a fixing portion formed at the other end of the coil body for fixing the coil body to the cylinder head with a bolt; and the bolt penetrating the fixing portion and the cylinder. An elastic member interposed between the head and the head is provided.

[0008] The ignition apparatus for an internal combustion engine according to claim 3, wherein according to the invention have a one end that can be fitted to the spark plug which is embedded in the recess of the cylinder head, the coil
The main body is formed into a cylindrical shape whose axial length is longer than the outer diameter,
A high voltage that generates a high voltage to supply the spark plug.
It has a built-in pressure generator and is formed on the cylinder head.
A coil body that is inserted into a plug hole, and a fixing portion that is formed at the other end of the coil body and that fixes the coil body to the cylinder head with a bolt; and the bolt penetrates the head of the bolt. And an elastic member interposed between the fixing unit and the fixing unit.

The ignition device for an internal combustion engine according to a fourth aspect of the present invention is the ignition device for an internal combustion engine according to the second aspect, wherein the elastic member seals between the fixed portion and the cylinder head. It is characterized by being integrally molded with the seal member. An internal combustion engine ignition device according to a fifth aspect of the present invention is the internal combustion engine ignition device according to the second or third aspect, wherein the elastic member is a compression coil spring.

The ignition device for an internal combustion engine according to claim 6 of the present invention is the ignition device for an internal combustion engine according to claim 2, 3 or 4, wherein the elastic member is made of rubber or elastomer. To do.

[0011]

According to the ignition device for an internal combustion engine according to claim 1 of the present invention, at least one of the upper end surface and the lower end surface is a convex curved surface between the fixed portion of the coil body and the cylinder head. Since the formed spacer is interposed, when mounting the coil body to the cylinder head with bolts that pass through this spacer, even if, for example, a spacer, cylinder head processing error, mounting error, etc. occur, the cylinder head and spacer It is possible to reduce the horizontal distance between the contact position of the spacer and the contact position of the spacer and the head of the bolt. Therefore, it is possible to reduce the bending moment generated in the coil body when the bolt is tightened. This has the effect of relieving the mechanical stress applied to the end of the coil body that can be fitted with the spark plug. Further, since at least one of the upper end surface and the lower end surface of the spacer is formed into a convex curved surface, when mounting the coil body on the cylinder head with a bolt penetrating the spacer,
For example, even if a processing error or a mounting error occurs in the spacer or the cylinder head, the contact area between the upper end surface of the spacer and the head of the bolt and the contact area between the lower end surface of the spacer and the cylinder head can be increased. This has the effect of obtaining the axial fastening force required to fix the coil body to the cylinder head without excessive tightening of the bolts.

According to the ignition device for an internal combustion engine of the second aspect of the present invention, since the elastic member is interposed between the fixed portion of the coil body and the cylinder head, the bolt penetrating the elastic member. Thus, when the coil body is mounted on the cylinder head, for example, even if a processing error, a mounting error or the like of the fixed portion or the cylinder head occurs, the elastic member can be deformed in the axial direction to absorb the gap due to these errors. The elastic force of the elastic member has an effect of relieving the mechanical stress applied to the ends of the spark plug and the coil body, and obtaining the axial fastening force necessary for fixing the coil body to the cylinder head.

According to the ignition device for an internal combustion engine of the third aspect of the present invention, the elastic member is interposed between the fixing portion of the main body and the head of the bolt for attaching the coil main body to the cylinder head and the coil. Therefore, when mounting the ignition device for an internal combustion engine on the cylinder head with the bolt penetrating the elastic member, for example, even if a fixing portion, a processing error of the cylinder head, an installation error, or the like occurs, the elastic member is deformed in the axial direction. The gap due to the error can be absorbed. The elastic force of this elastic member relieves the mechanical stress applied to the end of the internal combustion engine ignition device that can be fitted with the ignition plug, and the axial direction required to fix the internal combustion engine ignition device to the cylinder head. There is an effect of obtaining the fastening force.

According to the ignition device for an internal combustion engine of claim 4 of the present invention, an elastic member integrally formed with the seal portion through which the coil body penetrates is interposed between the fixed portion of the coil body and the cylinder head. Therefore, when the coil body is mounted on the cylinder head by the bolt penetrating the elastic member, for example, a processing error of the fixing portion or the cylinder head,
Even if a mounting error or the like occurs, the gap due to these errors can be absorbed by the axial deformation of the elastic member, and at the same time when the ignition device for an internal combustion engine is mounted on the cylinder head, the concave opening surface of the cylinder head and the fixing portion are fixed. The gap between and can be sealed. As a result, the elastic force of the elastic member can reduce the mechanical stress applied to the ends of the spark plug and the coil body, and can obtain the axial fastening force required to fix the coil body to the cylinder head. In addition, the seal portion can prevent water from entering the concave portion of the cylinder head.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 5 show an ignition device for an internal combustion engine according to a first embodiment of the present invention. As shown in FIGS. 1 and 2, the internal combustion engine ignition device 10 includes a coil body 11, a rubber boot portion 12, a stay portion 13, and a spacer 20.

The coil body 11 is formed in a cylindrical shape having an axial length longer than the outer diameter made of resin, for example, and has a built-in high voltage generating section for generating a high voltage to be supplied to the ignition plug 80. Fitting portion 11 located at one end of coil body 11
A power supply spring 15 that is electrically connected to the electrode portion 81 of the spark plug 80 is housed inside a. The cylindrical rubber boot portion 12 for sealing high voltage is formed such that the inner diameter of one end portion thereof can fit the fitting portion 11a. The inner diameter of the other end of the rubber boot portion 12 is formed so that the upper portion of the spark plug 80 can be fitted therein.

At the other end of the coil body 11, a stay portion 13 is provided.
Is integrally formed with the coil body 11, and the stay portion 13
A hole 13a is formed at the end of the. A spacer 20 attached by a method such as insert or outsert is located in this hole 13a. A through hole 20c into which the bolt 40 can be inserted is formed in the central axis portion of the spacer 20, and a screw hole 33 having a female screw portion into which the bolt 40 can be screwed is formed in the cylinder head 30. By inserting the bolt 40 into the spacer 20 and screwing it into the screw hole 33 and tightening it, the ignition device for internal combustion engine 1
0 can be attached to the cylinder head 30.

The spacer 20 is formed in a cylindrical shape made of metal or ceramic having high rigidity such as brass and aluminum. One end of the spacer 20 is formed to have an outer diameter that can be fitted into the hole 13a, and the outer diameter of the other end is formed to be larger than the outer diameter of the one end. Therefore, the spacer upper end surface 20a having a smaller outer diameter is in contact with the bolt head 41, and the spacer lower end surface 20 having a larger outer diameter is provided.
The spacer 20 is attached to the stay portion 13 so that b contacts the cylinder head 30. Spacer top surface 20
a and the spacer lower end surface 20b are formed in a convex curved surface shape, and the outer peripheral edge of the opening of the through hole 20c formed in the central axis portion is more axial than the peripheral edges of the spacer upper end surface 20a and the spacer lower end surface 20b. It is formed in a shape protruding to the outside.

Next, a process of assembling the internal combustion engine ignition device 10 to the cylinder head 30 will be described with reference to FIGS. 1 and 3. As shown in FIG. 1, a cylindrical plug hole 32 extending in the cylinder direction is formed in the cylinder head 30, and an ignition plug 80 is fixed to the bottom of the plug hole 32. A screw hole 33 located near the plug hole 32 is formed in the cylinder head 30 in parallel with the plug hole 32.

The coil body 11 is inserted into the plug hole 32 so that the upper portion of the spark plug 80 fixed to the bottom portion of the plug hole 32 fits into the fitting portion 11a of the coil body 11. By this insertion, the power supply spring 15 of the coil body 11 is pressed against the electrode portion 81 of the spark plug 80,
The high voltage generated by the high voltage generator built in the coil body 11 can be supplied to the spark plug 80.

A spacer 20 attached to the stay portion 13
After the stay portion 13 is positioned so that the through hole 20c of No. 2 communicates with the screw hole 33 formed in the cylinder head 30, the bolt 40 is inserted into the through hole 20c, and the screw hole 3
Screw the bolt 40 into 3. As shown in FIG. 3, by gradually tightening the bolt 40, the spacer 20 is sandwiched between the bolt head 41 and the cylinder head upper end surface 31, and when the bolt 40 reaches a predetermined tightening torque, the bolt 40 is tightened. The tightening is completed, and the internal combustion engine ignition device 10 is fixed to the cylinder head 30.

A comparative example in which the internal combustion engine ignition device 5 equipped with spacers having flat upper and lower end surfaces is attached to the cylinder head 30 will now be described with reference to FIG. As shown in FIG. 4, the spacer upper end surface 17 a and the spacer lower end surface 1
7b is such that when the internal combustion engine ignition device 5 of the comparative example is attached to the cylinder head 30, the bolt head lower end surface 41a, the spacer upper end surface 17a, the spacer lower end surface 17b, and the cylinder head upper end surface 31 are parallel to each other. It is set. However, the ignition device 5 for the internal combustion engine, the spacer 1
7, screw hole 33 of cylinder head 30 or bolt 4
When tightening the bolt 40 due to each processing error of 0 or the mounting error between the internal combustion engine ignition device 5 and the spacer 17,
In some cases, the bolt head lower end surface 41a, the spacer upper end surface 17a, the spacer lower end surface 17b, and the cylinder head upper end surface 31 (hereinafter referred to as “each end surface”) cannot be maintained in a parallel positional relationship. Then, the lower end surface 4 of the bolt head
A gap 53 is formed between the 1a and the spacer upper end surface 17a,
A gap 54 is formed between the spacer lower end surface 17b and the cylinder head upper end surface 31. Therefore, the bolt head lower end surface 41a and the spacer upper end surface 17a contact at the position indicated by the arrow C in FIG. 4, and the spacer lower end surface 17b contact the cylinder head upper end surface 31 at the position indicated by the arrow D. Become. The horizontal distance between the position indicated by the arrow C and the position indicated by the arrow D is represented by Y in FIG.

In this way, even if the upper and lower end surfaces of the spacer 17 are set to be flat, if the respective end surfaces cannot be kept in a parallel positional relationship due to a processing error or the like, the spacer upper end surface 17a and Spacer bottom face 1
Bending moments that try to make 7b parallel to the bolt head lower end surface 41a and the cylinder head upper end surface 31 are generated in proportion to the horizontal distance Y. As a result, a bending moment is generated in the coil body 11, and a radial force is generated on the rubber boot portion 12 located at the lower end of the coil body 11. As a result, mechanical stress is generated in the connection between the fitting portion 11a of the ignition device 5 for the internal combustion engine and the ignition plug 80, which is located in the rubber boot portion 12 shown in FIG. 1, the rubber boot portion 12, and the ignition plug 80. Mechanical stress is generated in each part of the coil body 11. Particularly, as the axial length becomes longer with respect to the outer diameter dimension, the radial force applied to the lower end portion of the coil body 11 increases.

As shown in FIG. 3, in comparison with the comparative example described above, the spacer upper end surface 20a and the spacer lower end surface 20b of the spacer 20 attached to the coil body 11 of the first embodiment have a convex curved shape. Has been formed.
This curved surface shape is for absorbing processing errors and the like of the bolt head lower end surface 41a, the spacer upper end surface 20a, the spacer lower end surface 20b, and the cylinder head upper end surface 31. For example, when the bolt 40 is tightened, a gap 51 is formed between the bolt head lower end surface 41a and the spacer upper end surface 17a, and a gap 52 is formed between the spacer lower end surface 17b and the cylinder head upper end surface 31. The lower end surface 41a of the head portion and the upper end surface 17a of the spacer come into contact with each other at a position indicated by an arrow A in FIG.
The spacer lower end surface 17b and the cylinder head upper end surface 31 are in contact with each other at a position indicated by an arrow B. The horizontal distance between the position indicated by the arrow A and the position indicated by the arrow B is represented by X in FIG. 3, and when compared with the horizontal distance Y of the comparative example using the spacer 17, X <Y is larger or smaller. Get involved. Therefore, as compared with the comparative example using the spacer 17, the coil body 11
The bending moment with respect to can be reduced. Since the horizontal distance X can be reduced as the bolt 40 is tightened, the bending moment with respect to the coil body 11 can be further reduced. As a result, the mechanical stress generated at the connecting portion between the fitting portion 11a and the spark plug 80 can be relieved.

Since the spacer upper end surface 20a and the spacer lower end surface 20b are formed in a curved shape, the contact areas at the positions indicated by the arrows A and B are indicated by the arrows C and D when the spacer 17 is used. It can be larger than the contact area of the position. Thereby, the spacer upper end surface 20
a and the spacer lower end surface 20b are the bolt head lower end surface 41.
a. It is not necessary to tighten the bolt 40 until it becomes parallel to the cylinder head upper end surface 31, respectively. If the tightening is completed at the time when a certain tightening torque is generated in the bolt 40, the internal combustion engine ignition device 10 is The axial force required to fix the head 30 can be obtained.

Further, when the depths of the plug holes 32 are different, a spacer having a length corresponding to each depth of the plug holes is prepared so that the depth of the internal combustion engine ignition device can be adjusted without changing the length. The ignition device 10 for an internal combustion engine can be attached to different plug holes. This gives 1
Since the ignition devices for internal combustion engines of various types can be mounted on the cylinder heads having different plug hole depths, the ignition devices for internal combustion engine can be standardized.

Here, a modification of the mounting direction of the spacer 20 is shown in FIGS. As described above, the spacer 2
No. 0 is attached to the stay portion 13 so that the spacer upper end surface 20a having a smaller outer diameter contacts the bolt head 41 and the spacer lower end surface 20b having a larger outer diameter contacts the cylinder head 30. However, it is not limited to this, and FIG.
As shown in FIG. 3, the stay part 1 has a large outer diameter spacer upper end surface 20 b in contact with the bolt head 41, and a small outer diameter spacer lower end surface 20 a in contact with the cylinder head 30.
You may attach to 3. Further, as shown in FIG. 6, the upper end surface 2
You may use the spacer 22 which made the outer diameter of 2a large and made it the same diameter as the outer diameter of the lower end surface 22b.

In the first embodiment, the upper and lower end surfaces of the spacer 20 are formed to have convex curved surfaces, but the present invention is not limited to this, and for example, either the upper end surface or the lower end surface of the spacer can be formed. One of them may be formed into a convex curved surface shape. (Second Embodiment) FIG. 6 shows an ignition device for an internal combustion engine according to a second embodiment of the present invention. The same reference numerals are attached to the substantially same components as those in the first embodiment.

As shown in FIG. 6, the ignition device 1 for an internal combustion engine
The spacer 21 located between the stay portion 13 of 0 and the cylinder head 30 is made of an elastic member.
This is different from the first embodiment in that both upper and lower end surfaces of are formed flat. The spacer 21 is formed in a cylindrical shape made of an elastic member such as rubber or elastomer, and the spacer upper end surface 21a and the spacer lower end surface 21b are formed flat. One end of the spacer 21 has a hole 13 in the stay 13.
It is formed to have an outer diameter that can be fitted into a, and the outer diameter of the other end is formed to be larger than the outer diameter of the one end. Spacer 2
A through hole 21c is formed in the central axis portion of the collar 1, and the collar 24 has a cylindrical shape and can be fitted into the inner wall of the through hole 21c.
Has been inserted. The collar 24 is made of metal such as stainless steel.

At the time of assembling, the spacer upper end surface 21a and the spacer lower end surface 21b of the spacer 21 are fixed to the bolt head lower end surface 41a and the cylinder head upper end surface 31 due to various processing errors of the spacer 21 and the like as the bolt 40 is tightened.
In some cases, a non-parallel state that cannot be kept parallel to each other may occur. Then, a gap is created between the bolt head lower end surface 41a and the spacer upper end surface 21a, and between the spacer lower end surface 21b and the cylinder head upper end surface 31. However, since the spacer 21 is deformed in the axial direction by further tightening the bolt 40, the gap due to the non-parallel state can be absorbed. As a result, the elastic force of the spacer 21 can sufficiently generate the axial force required for the bolt 40.

Also, since the spacer 21 is deformed to absorb the gap due to the non-parallel state, the coil body 11
The bending moment with respect to can be reduced. As a result, the mechanical stress generated at the connecting portion between the fitting portion 11a and the spark plug 80 can be relieved. Further, when the depths of the plug holes 32 are different, a spacer having a length corresponding to each depth of the plug holes is prepared so that the plugs having different depths can be obtained without changing the length of the ignition device for an internal combustion engine. The ignition device 10 for an internal combustion engine can be attached to the hall. Accordingly, one type of ignition device for an internal combustion engine can be mounted on cylinder heads having different depths of plug holes, so that the ignition device for an internal combustion engine can be standardized.

In the second embodiment, the spacer upper end surface 21a and the spacer lower end surface 21b of the spacer 21 are formed to be flat, but the present invention is not limited to this, and may be a convex curved surface or the like. good. In this case, the first
Since the same effect as that of the embodiment is obtained, an effect combined with the effect of the first embodiment can be obtained. Further, in the second embodiment, the collar 24 is fitted in the through hole 21c of the spacer 21, but in the present invention, for example, the collar may not be used.

Further, in the second embodiment, the internal combustion engine ignition device 10 is attached to the cylinder head 30 by the bolt 40 penetrating the hole 13a formed in the stay portion 13 at one place. However, the present invention is not limited to this, and for example, the internal combustion engine ignition device may be attached to the cylinder head with bolts by providing two or more holes in the stay portion at positions sandwiching the coil body.

(Third Embodiment) FIG. 7 shows an ignition device for an internal combustion engine according to a third embodiment of the present invention. The same reference numerals are attached to the substantially same components as those in the first embodiment. As shown in FIG. 7, the first embodiment differs from the first embodiment in that a spring 50 is used instead of the spacer located between the stay portion 13 and the cylinder head 30 of the internal combustion engine ignition device 10.

A cylindrical collar 60 made of metal such as stainless steel is attached to the hole 13a formed in the stay portion 13 of the coil body 11 by a method such as insert or outsert. A hole 60a is formed in the central axis portion of the collar 60 so that the bolt 40 can penetrate therethrough. A compression coil spring 50 made of metal that covers the outer periphery of the bolt shaft portion 42 is located at the axially intermediate portion of the bolt 40 that penetrates the hole portion 60a. Further, the bolt shank 42 is made up of a metal washer 7
It penetrates through the hole 71 formed in 0. The hole 71 of the washer 70 has a diameter slightly smaller than the outer diameter of the thread formed on the bolt shaft 42. Therefore, when the ignition device 10 for the internal combustion engine is assembled, the collar 60 of the stay portion 13, the compression coil spring 50, and the washer 70.
When the bolt 40 is inserted in this order, the washer 70 does not easily come off the bolt shaft portion 42. Therefore, the compression coil spring 5 located between the stay portion 13 and the washer 70 is
It prevents the loss of 0. The screw hole 33 formed in the cylinder head 30 is set to have a screw hole depth such that a proper repulsive force is generated in the compression coil spring 50 when the bolt 40 is completely tightened.

At the time of assembly, the collar upper end surface 60b and the collar lower end surface 60c of the collar 60 become different from the bolt head lower end surface 41a and the cylinder head upper end surface 31 due to various processing errors of the collar 60 and the like as the bolt 40 is tightened. There may be non-parallel states that cannot be kept parallel. However, since the compression coil spring 50 is compressed and deformed as the bolt 40 is tightened,
The gap due to this non-parallel state can be absorbed. By tightening the bolt 40 until the lower end of the bolt 40 comes into contact with the bottom of the screw hole 33, an appropriate repulsive force can be generated in the spring 50.

Further, since the gap due to the non-parallel state is absorbed by the deformation of the compression coil spring 50, the bending moment with respect to the coil body 11 can be reduced. As a result, the fitting portion 11a and the spark plug 80
It is possible to relieve the mechanical stress generated in the connection part with. Furthermore, when the depths of the plug holes 32 are different,
By preparing a compression coil spring having a length corresponding to each depth of the plug holes, the internal combustion engine ignition device 10 is mounted in the plug holes having different depths without changing the length of the internal combustion engine ignition device. be able to. As a result, one type of ignition device for an internal combustion engine can be mounted on cylinder heads having different plug hole depths.
The ignition device for an internal combustion engine can be standardized.

Further, by preventing the compression coil spring 50 from falling off by the washer 70, the bolt 40 and the spring 50 can be supplied integrally with the internal combustion engine ignition device 10, and the assembling workability is improved. You can In the third embodiment, the internal combustion engine ignition device 10 is attached to the cylinder head 30 by the bolt 40 penetrating the hole 13a formed at one place in the stay portion 13, but the present invention is not limited to this. However, the ignition device for an internal combustion engine may be attached to the cylinder head with bolts by providing two or more holes in the stay portion at positions such that the coil body is sandwiched.

(Fourth Embodiment) FIG. 8 shows an ignition device for an internal combustion engine according to a fourth embodiment of the present invention. The same reference numerals are attached to the substantially same components as those in the first embodiment. As shown in FIG. 8, in place of the spacer located between the stay portion 13 and the cylinder head 30 of the internal combustion engine ignition device 10,
The difference from the first embodiment is that a compression coil spring 50 is used between the bolt head lower end surface 41a of the bolt 40 and the stay portion upper end surface 13b.

A cylindrical collar 62 made of metal such as stainless steel is attached to the hole 13a formed in the stay 13 of the coil body 11 by an insert or outsert method. A hole portion 62b is formed in the central axis portion of the collar 62 so that the bolt 40 can penetrate therethrough. The inner wall of the hole portion 62b has a collar portion 6 having an inner diameter slightly smaller than the thread diameter of the bolt 40.
2d is formed. In order to prevent the lower end surface 13c of the stay portion 13 from coming into contact with the cylinder head upper end surface 31, the lower end portion 62a of the collar 62 is formed to project from the lower end surface 13c of the stay portion 13. The screw hole 33 formed in the cylinder head 30 is set to have a screw hole depth such that a proper repulsive force is generated in the compression coil spring 50 when the bolt 40 is completely tightened.

At the time of assembly, the collar upper end surface 62c and the collar lower end surface 62a of the collar 62 become different from the bolt head lower end surface 41a and the cylinder head upper end surface 31 due to various processing errors of the collar 62 and the like as the bolt 40 is tightened. There may be non-parallel states that cannot be kept parallel. However, since the compression coil spring 50 is compressed and deformed as the bolt 40 is tightened,
The gap due to this non-parallel state can be absorbed. By tightening the bolt 40 until the lower end of the bolt 40 comes into contact with the bottom of the screw hole 33, an appropriate repulsive force can be generated in the spring 50.

Further, the deformation of the compression coil spring 50 absorbs the gap due to the non-parallel state, so that the bending moment with respect to the coil body 11 can be reduced. As a result, the fitting portion 11a and the spark plug 80
It is possible to relieve the mechanical stress generated in the connection part with. Further, the compression coil spring 50, the washer 7
When the bolt 40 is inserted in the order of 0 and the collar 62 of the stay portion 13, the bolt shaft portion 42 does not easily drop from the stay portion 13, so the bolt 40 inserted in the collar 62,
The compression coil spring 50 and the washer 70 can be prevented from falling off. Thereby, the bolt 40 and the spring 50 can be supplied integrally with the ignition device 10 for the internal combustion engine, and the workability of assembling can be improved.

Furthermore, the collar 6 made of stainless steel
Since the lower end portion 62a of No. 2 projects from the lower end surface 13c of the stay portion 13, the lower end surface 13c of the stay portion 13 made of resin does not contact the cylinder head upper end surface 31 and the lower end portion 62a of the collar 62 is It contacts the upper end surface 31 of the cylinder head. Although the washer 70 is inserted between the compression coil spring 50 and the upper end surface 13b of the stay portion 13 in the fourth embodiment, in the present invention, for example, the washer may not be used.

Further, in the fourth embodiment, the internal combustion engine ignition device 10 is attached to the cylinder head 30 by the bolt 40 penetrating one hole 13a formed in the stay portion 13, but this is not the case in the present invention. Is not limited to
For example, the ignition device for an internal combustion engine may be attached to the cylinder head with bolts by providing two or more holes in the stay portion at positions where the coil body is sandwiched. In this case, the length of the bolt, the depth of the screw hole, or the axial length of the collar is set so that the lower end of the collar does not come into contact with the upper end surface of the cylinder head. Accordingly, even if the lower end of the collar and the upper end surface of the cylinder head do not come into contact with each other, the internal combustion engine ignition device is sufficiently fixed to the cylinder head by the urging force of the compression coil spring covering the outer circumference of the bolt in the cylinder direction.

(Fifth Embodiment) FIG. 9 shows an ignition device for an internal combustion engine according to a fifth embodiment of the present invention. The same reference numerals are attached to the substantially same components as those in the first embodiment. As shown in FIG. 9, the lower end surface 13c of the stay portion 13 and the plug hole 3 are formed on the spacer 26 made of an elastic member located between the stay portion 13 and the cylinder head 30 of the ignition device for an internal combustion engine.
The second embodiment differs from the first embodiment in that a seal portion for waterproofing the upper end surface 32a of the second opening is provided.

The spacer 26 is made of an elastic member such as rubber or elastomer, and the spacer portion 26a and the seal portion 26b are integrally formed. The spacer portion 26a is
It is formed in a cylindrical shape, and both upper and lower end surfaces are formed flat. One end of the spacer portion 26a has a hole portion 1 of the stay portion 13.
The outer diameter of the other end is formed to be larger than the outer diameter of the one end. A through hole 26c is formed in the central axis portion of the spacer portion 26. On the other hand, the seal portion 26b is formed in a disk shape having flat upper and lower end surfaces, and a hole portion 26d into which the coil body 11 can be fitted is formed in the center portion.

During assembly, after the coil body 11 is fitted into the hole 26d of the seal portion 26b of the spacer 26 from the direction of the fitting portion 11a, the through hole 26c of the spacer portion 26a is formed into the screw hole 33 formed in the cylinder head 30. To communicate with
The stay portion 13 is positioned. After this, the through hole 26c
The bolt 40 is passed through and the bolt 40 is screwed into the screw hole 33. Spacer 26 according to tightening bolt 40
There may be a non-parallel state in which the upper and lower end surfaces of the spacer portion 26a cannot be kept parallel to the bolt head lower end surface 41a and the cylinder head upper end surface 31, respectively, due to processing errors of the spacer portion 26a and the like. However, by further tightening the bolt 40, the spacer 2
Since 6 is deformed in the axial direction, the gap due to this non-parallel state can be absorbed. This allows the spacer 2
The elastic force of 6 can sufficiently generate the axial force required for the bolt 40. At the same time, the stay portion 13
Lower end surface 13c of the plug and upper end surface 31 of the opening of the plug hole 32
As the seal portion 26b located between a and a is tightened with the bolt 40, the seal portion 26b is compressed. As a result, it is possible to prevent water from entering the plug hole 32.

Further, since the gap due to the non-parallel state is absorbed by the deformation of the spacer portion 26a, the bending moment with respect to the coil body 11 can be reduced. As a result, the mechanical stress generated at the connecting portion between the fitting portion 11a and the spark plug 80 can be relieved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an ignition device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of an internal combustion engine ignition device according to a first embodiment.

FIG. 3 is a partial cross-sectional view showing an assembled state of the internal combustion engine ignition apparatus according to the first embodiment.

FIG. 4 is a partial cross-sectional view showing an assembled state of an internal combustion engine ignition device of a comparative example.

FIG. 5 is a partial cross-sectional view showing a modified example of the internal combustion engine ignition device according to the first embodiment.

FIG. 6 is a partial cross-sectional view showing a modified example of the ignition device for an internal combustion engine according to the first embodiment.

FIG. 7 is a partial cross-sectional view showing an assembled state of the internal combustion engine ignition apparatus according to the second embodiment.

FIG. 8 is a partial cross-sectional view showing an assembled state of the ignition device for an internal combustion engine according to the third embodiment.

FIG. 9 is a partial cross-sectional view showing an assembled state of the ignition device for an internal combustion engine according to the fourth embodiment.

FIG. 10 is a partial cross-sectional view showing an assembled state of the ignition device for an internal combustion engine according to the fifth embodiment.

[Explanation of symbols]

10 Ignition device for internal combustion engine 11 coil body 11a Fitting part (one end) 12 Rubber boots 13 Stay part (fixed part) 15 Power supply spring 20, spacer 21, 22, 26 Spacer (elastic member) 20a Spacer top surface (spacer top surface) 20b Lower end surface of spacer (lower end surface of spacer) 26a Spacer part (elastic member) 26b Seal part (elastic member, seal member) 30 cylinder head 31 Upper end surface of cylinder head 32 plug hole (cylinder head recess) 40 volts 41 bolt head (bolt head) 41a Bolt head lower end surface 50 Compression coil spring (elastic member) 62 colors (cylindrical member) 80 spark plug

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-99641 (JP, A) Actually open 1-127975 (JP, U) Actually open 3-100920 (JP, U) Actually open 61- 72827 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F02P 15/00 F02P 13/00

Claims (6)

(57) [Claims] [Claim 1] have a end of one fittable to buried spark plug recess of the cylinder head, the axial direction than the outer diameter
It has a long cylindrical shape and is used to supply the spark plug.
Built-in high voltage generator that generates high voltage for
Insert into the plug hole formed in the cylinder head
A coil main body, a fixing portion formed at the other end of the coil main body and fixing the coil main body to the cylinder head with a bolt, and interposed between the fixing portion and the cylinder head, and A spacer having a through hole through which the bolt penetrates, the spacer having upper and lower end surfaces protruding from the fixing portion, the spacer contacting an upper end surface of the spacer contacting the head of the bolt or the cylinder head An ignition device for an internal combustion engine, wherein at least one of the lower end surfaces of the engine is formed into a convex curved surface. 2. A closed end portion recess while fittable to buried spark plug of the cylinder head, the coil body
Is formed into a cylindrical shape whose axial length is longer than the outer diameter.
High voltage generator to generate high voltage to supply fire plug
The built-in raw part is installed on the cylinder head.
A coil body to be inserted into a lug hole, a fixing portion formed at the other end of the coil body and fixing the coil body to the cylinder head with a bolt, the bolt penetrating the fixing portion and the cylinder head. An ignition device for an internal combustion engine, comprising: an elastic member interposed between the ignition device and the elastic member. 3. have a one end that can be fitted to the spark plug which is embedded in the recess of the cylinder head, the coil body
Is formed into a cylindrical shape whose axial length is longer than the outer diameter.
High voltage generator to generate high voltage to supply fire plug
The built-in raw part is installed on the cylinder head.
A coil body inserted into a lug hole, a fixing portion formed at the other end of the coil body and fixing the coil body to the cylinder head with a bolt, the bolt penetrates, and the head of the bolt and the An ignition device for an internal combustion engine, comprising: an elastic member interposed between the fixed part and the fixed part. 4. The ignition device for an internal combustion engine according to claim 2, wherein the elastic member is integrally formed with a seal member that seals between the fixed portion and the cylinder head. 5. The ignition device for an internal combustion engine according to claim 2, wherein the elastic member is a compression coil spring. 6. The ignition device for an internal combustion engine according to claim 2, 3 or 4, wherein the elastic member is made of rubber or elastomer.