JPS63183219A - Internal combustion engine - Google Patents

Abstract

PURPOSE:To facilitate the manufacture of an internal combustion engine provided with a fuel activation chamber by providing a fuel activation chamber in a holder formed in a body different from a cylinder head, and then fixing the holder using an inserting hole for the cylinder head and the internal periphery part of a cylinder block. CONSTITUTION:An internal combustion engine 1 is provided with a fuel activation chamber 3, which is located in the neighborhood of the upper part of a main combustion chamber 2, and also provided with a valve 13 for opening and closing the two chambers 2, 3 between these chambers 2, 3. In this case, the fuel activation chamber 3 is provided in the lower part 4b of a cylindrical holder 4 having a stage part 4c which is formed in such a manner that its upper part 4a has a small diameter and its lower part 4b has a large diameter respectively. While, on a cylinder head 8 are provided a hole 8a having a small bore and a hole 8b having a large bore corresponding to the shape of the holder 4, and at the same time, between these holes is provided an annular stage part 8c. And further, the hole 8b having a large bore is provided eccentrically to the main combustion chamber so that a part of it overlaps a cylinder liner which is //fixed on the internal periphery surface of a cylinder block 33.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to an internal combustion engine, and more specifically, it has a fuel activation chamber in the vicinity of a main combustion chamber, and a space between the fuel activation chamber and the main combustion chamber. This invention relates to an internal combustion engine equipped with a valve that opens and closes between these parts.

b. Prior art and its problems Combustion systems for internal combustion engines, for example compression ignition engines, include direct injection, pre-combustion chamber, swirl chamber, and air chamber.

However, in both combustion methods, liquid fuel is injected directly into the combustion chamber, so before a uniform gas mixture of the injected liquid fuel and air is formed,
Compression ignition combustion may have started. In this case, unburned hydrocarbon is generated within the combustion chamber and black smoke is emitted from the compression ignition engine, resulting in a decrease in fuel efficiency and contributing to air pollution. .

In addition, many of the current compression ignition engines burn at high compression ratios and high temperatures, so they emit nitrogen oxides (Nox).
) were emitted in large quantities, which also contributed to air pollution.

Therefore, in view of these circumstances, the applicant first requested the following:
We have proposed an internal combustion engine that has a fuel activation chamber near the main combustion chamber and a valve that opens and closes the space between the activation chamber and the main combustion chamber. 277908 etc.).

In these internal combustion engines, the valve has a structure in which the valve body moves from its valve seat toward the main combustion chamber to open and close. No large loss occurred, and therefore it was possible to improve the rotational speed and maximum output of the internal combustion engine.

However, as a result of further research, the applicant has arrived at the present invention, which makes it possible to easily manufacture or assemble an internal combustion engine equipped with a fuel activation chamber.

That is, an object of the present invention is to provide an internal combustion engine that is easy to manufacture or assemble.

Means for Solving Problem C1 In order to achieve the above object, the present invention has a fuel activation chamber in the vicinity of the main combustion chamber, and a space between the fuel activation chamber and the main combustion chamber. In an internal combustion engine equipped with a valve that opens and closes, the valve is configured to open when its valve body is moved toward the fuel activation chamber, and the valve is configured to open in a holder formed separately from the fuel activation chamber cylinder head. Further, a holder insertion hole having a stepped portion approximately at the center thereof is formed in the cylinder head eccentrically with respect to the main combustion chamber to the extent that a portion thereof overlaps with the inner circumferential edge of the cylinder block. , a stepped portion corresponding to the stepped portion of the holder fitting hole is formed on the holder, so that when the holder is fitted and installed in the holder fitting hole, the holder
It is configured to be fixed by the stepped portion of the holder fitting hole of the cylinder head and the inner circumferential edge of the cylinder block.

d. Embodiments Hereinafter, embodiments of the internal combustion engine according to the present invention will be described in detail with reference to the accompanying drawings.

1 to 4 show an embodiment of the present invention.

The internal combustion engine 1 of this embodiment is a case where the present invention is applied to a compression ignition engine such as a diesel engine.

The internal combustion engine 1 has a fuel activation chamber 3 in the upper vicinity of the main combustion chamber 2 thereof.

The fuel activation chamber 3 is formed in a lower part 4b of a cylindrical holder 4 with a stepped portion 4c, in which an upper part 4a is formed with a small diameter and a lower part 4b is formed with a relatively large diameter.

The fuel activation chamber 3 is formed in the shape of a rotating body centered on the vertical axis of the holder 4, and in particular, its upper portion is formed in a conical shape.

Further, the holder 4 is formed with a substantially semi-spherical recess 5 opening downward below the fuel activation chamber 3 .

Corresponding to this depression 5, a substantially semispherical depression 7 opening upward is also formed in the upper part of the piston 6.

When the main combustion chamber 2 is at its compression top dead center, the depression 5 and the depression 7 form a substantially spherical shape in which swirl A is likely to occur, except for the flat plate-shaped portion between the cough piston and the cylinder head 8. .

The upper part 4a of the holder 4 has a communication hole 9 extending in its axial direction.
is formed.

A rod 11 having a valve body 10 at the bottom thereof is slidably inserted into the insertion hole 9 and is installed in a state where it is sealed with the holder 4.

The valve body 10 has a holder 4 between the fuel activation chamber 3 and the recess 5.
A valve 13 is configured together with a valve seat 12 formed in the above.

A spring 15 is interposed between the tappet 14 fixed to the upper end of the iron 11 and the cylinder head 8.

The valve body 10 is constantly urged upward by the elastic force of the spring 15, and is moved up and down as the cam 16 in contact with the tappet 14 rotates.

The cam 16 is rotated at a predetermined timing by receiving power from a crankshaft (not shown) via a power transmission means (not shown).

Therefore, the valve 13 is opened and closed at a predetermined timing by the rotation of the cam 16.

The opening period of the valve 13 is preferably an appropriate period from around the end of the compression process to the beginning of the exhaust process, but is not particularly limited to this.6 For example, the opening period of the valve 13 can be set from around the end of the compression process to It can also be a long period until about the end of the inhalation process.

Further, it is preferable that the opening timing of the valve 13 is configured to be advanced in accordance with the rotation speed of the internal combustion engine.
Note that this advancing device can be easily constructed and installed in the above-mentioned power transmission means using conventional technology, so a detailed explanation thereof will be omitted.

Furthermore, a fuel supply hole 18 is formed in the side of the holder 4 for guiding and supplying the injected fuel from the fuel injection nozzle 17 into the fuel activation chamber 3 .

This fuel supply hole 18 is preferably formed eccentrically with respect to the fuel activation chamber 3 (see FIG. 2), so that the injected fuel from the fuel injection nozzle 17 is directed clockwise in FIG. Swirl B is formed. This swirl B
This promotes fuel activation.

Further, the fuel supply hole 18 of the holder 4 and the recess 5 are communicated with each other through a small diameter compressed air introduction hole 18a.

This compressed air introduction hole 18a guides compressed air within the main combustion chamber 2 into the fuel supply hole 18. The compressed air from this compressed air introduction hole 18a is transferred to the fuel injection nozzle 17.
The fuel is premixed with the fuel injected from the fuel chamber 3 and is injected into the fuel activation chamber 3.

In this way, the fuel supply hole 18 functions to mix fuel and compressed air in advance and send the mixture to the fuel activation chamber 3, so that it forms a so-called pre-mixing boat for the fuel activation chamber 3.

Furthermore, the tip of the glow plug 19 faces the fuel activation chamber 3 in a slightly protruding manner. The glow plug 19 is preferably arranged slightly downstream from the hole 18 in the direction of fuel injection.

Furthermore, a female screw hole 20 is formed on the side of the holder 4 facing the fuel supply hole 18. In the female screw hole 20,
The spark plug 21 to which the spark plug 21 is connected is
The tip 21a is located within the female threaded hole 20 so as not to interfere with the swirl B within the fuel activation chamber 3.
Of course, the tip portion 21a may be installed so as to protrude from the female screw hole 20.

The spark plug 21 is inserted into the female thread 2 through a hole 22 formed in the rad 8 to the cylinder corresponding to the female thread hole 20 of the holder 4.
It is removably fixed to 0.

Furthermore, another hole 23 is formed in the holder 4, and holes 24, 25 are formed in the cylinder head 8, corresponding to the wire holes. The hole 23 is formed facing downstream with respect to the swirl B in the fuel activation chamber 3 .

The hole 25 communicates the hole 24 with the main combustion chamber 2 . Therefore, the fuel activation chamber 3 has holes 23, 24 . ．． It communicates with the main combustion chamber 2 via 25.

Further, between the holes 24 and 25, there is an air amount adjusting device 2 configured to change the degree of opening of the hole 25 with respect to the hole 24.
6 is installed interveningly.

This air amount adjusting device 26 consists of a small cylindrical rod 27 having an inclined portion 27a at its tip, and a rotating means 28 for appropriately rotating the rod.

The small rod 27 is rotatably supported in a hole 29 formed in the cylinder head 8, with its inclined portion 27a disposed above the mouth of the hole 25.

The small rod 27 is connected to the rotating means 28 via a connecting rod 30.

The air amount adjustment device 26 detects that the internal combustion engine is operating at high speed, acceleration, and/or high load, and supplies the fuel from the main combustion chamber 2 to the fuel activation chamber via the compressed air introduction hole 18a. This is provided to supplement the amount of compressed air sent to the holes 25, 24 by rotating the small rod 27 and squeezing the opening by overlapping the inclined portion 27a with the opening of the hole 25. .23 serves to regulate the amount of compressed air passing through.

The rotation means 28 may be configured to, for example, change the number of rotations of a crankshaft (not shown), the amount of depression of an accelerator pedal, the degree of change in the amount of depression of an accelerator pedal, or the degree of change of flow velocity on the downstream side of a throttle valve in an intake pipe (not shown). The edge 7 door 27 is rotated by an appropriate amount based on.

This rotation means 28 includes, for example, a processing device such as a microcomputer that processes detection data obtained by detecting various changes as described above, a stepping motor that is driven as appropriate based on the processing results of the processing device, and It may be constituted by a speed reduction device, etc., or it may be constituted by being mechanically connected directly to a throttle valve or an accelerator pedal, etc. via a connecting means (not shown).In short, the internal combustion engine The configuration may be determined as appropriate, taking into consideration the purpose of use.

Further, the upper surface 10a of the valve body 10 is formed into a conical shape similarly to the ceiling surface 3a of the fuel activation chamber 3. Thereby, when the valve body 10 is moved upward and comes into contact with the ceiling surface 3a, the space between the valve body IO and the cylinder head 8 is completely sealed.

Further, two annular grooves 31 are formed on the upper surface 10a of the valve body 10, and two annular grooves 31 are formed on the side peripheral surface 10b.
2 is formed. Note that the number of these grooves 31 and 32 is not particularly limited.
During operation of the valve 13, carbon adhering to the upper surface 10a and/or ceiling surface 3a of the valve body 10 is efficiently peeled off, and carbon adhering to the side peripheral surface 10b of the valve body 10 and/or the valve seat 12 is also removed. Efficiently peeled off. especially,
By being able to peel off the carbon between the upper surface 10a of the valve body 10 and the ceiling surface 3a, good sealing between the valve body 10 and the cylinder head 8 can be maintained at all times when the valve body 10 is moved upward. .

Furthermore, as described above, the holder 4 has an annular stepped portion 4C between its upper portion 4a and lower portion 4b. Corresponding to the shape of this holder 4, a small diameter hole 8a and a large diameter hole 8b are formed in the cylinder head 8, and a hole 8a and a hole 8b are formed.
An annular step portion 8C is formed between the two.

In this embodiment, the hole 8b is formed largely eccentrically with respect to the main combustion chamber 2 so that a portion of the hole 8b overlaps the cylinder liner 34 fixed to the inner circumferential surface of the cylinder block 33. There is.

Here, attachment of the holder 4 will be explained.

The holder 4 has a hole 3 a from below the cylinder head 8 .

8b and is fixed to the cylinder and integrated with the Rad 8. At this time, the stepped portion 4C of the holder 4 and the stepped portion 8c of the cylinder rod 8 are brought into close contact. After that, this cylinder head is fixed to the cylinder block 33. As a result, the vertical movement of the holder 4 is restricted by the stepped portion 8C of the cylinder head 8 that presses the stepped portion 4C, and the upper end surface 34a of the liner 34 that presses a part of the bottom surface 4d. completely fixed.

It is preferable that the holder 4 is prevented from rotating relative to the cylinder head 8 by a rotation locking key (not shown) at some point. In this case, there is no rotation relative to the cylinder head 8, so the locking key is not needed in this case.

Further, as a fixed position of the holder 4, a part of the bottom surface 4d of the holder 4 is fixed to the cylinder block 33 far beyond the liner 34.
Of course, it is also possible to reach this point.

Furthermore, in this embodiment, two guide grooves 35 are formed that extend linearly or curvedly from the recess 7 of the piston 6. Note that the number of guide grooves 35 is not particularly limited, and the grooves 35 effectively cause the air in the main combustion chamber 2 to swirl during the compression process. therefore,
When the guide groove 35 is formed in a curved shape, it is preferable to match the direction of the swirl. In FIG. It shows the installation positions of provided intake valves and exhaust valves (not shown) relative to the piston 6.

Next, the operation of this embodiment will be explained.

When the internal combustion engine 1 is currently in a compression process, the air within the main combustion chamber 2 is compressed. Then, the compressed air in the main combustion chamber 2 is injected into the fuel supply hole 18 through the compressed air introduction hole 18a, and guided into the fuel activation chamber 3 through the fuel supply hole. Also, at this time, fuel is injected from the fuel injection nozzle 8 into the fuel supply hole 18 . This injected fuel is
The compressed air introduced from the main combustion chamber 2 through the compressed air introduction hole 18a is mixed in advance in the fuel supply hole 18, and then injected into the fuel activation chamber 3. Due to this ejection, the fuel activation chamber 3
Swirl B is formed within the fuel, and activation of the injected fuel is promoted. At the same time, the injected fuel is heated by the glow plug 19 to promote its activation and form a uniform air-fuel mixture.

Next, due to the rotation of the cam 16, the valve lO is moved upward near the compression top dead center, and the valve 13 is opened. At the same time, a spark is emitted by the spark plug 21 at a predetermined ignition timing. By opening the valve lO, the fuel activation chamber 3
The air-fuel mixture in the main combustion chamber 2 mixes with the compressed air in the main combustion chamber 2 and begins to ignite and burn, and is further reliably ignited by the spark from the ignition plug 19. Due to this ignition, the air-fuel mixture in the fuel activation chamber 3 begins to burn and its pressure is rapidly increased, and the space between the valve body 10 and the valve seat 12 and the hole 18.
It is injected into the main combustion chamber 2 via 18a. At this time,
In particular, due to the combustion mixture injected through the hole L8a,
A strong swirl is formed within the main combustion chamber 2.

Due to this swirl, combustion within the main combustion chamber 2 is performed smoothly.

Furthermore, as described above, when the valve 13 is opened and combustion begins, the valve body 10 comes into contact with the ceiling surface 3a to seal between the valve body and the cylinder head 8. This seal allows the combustion air-fuel mixture in the fuel activation chamber 3 to be transferred to the holder 4 and the cylinder rad 8.
This prevents leakage to the outside through the gap between the

Thereafter, the valve 13 is closed at an appropriate time, such as near the end of the expansion stroke or near the end of the exhaust stroke. Thereafter, the same operations as described above are repeated.

Note that the internal combustion engine 1 of the above embodiment includes an air amount adjusting device 2.
Instead of or in addition to 6, it is also possible to additionally install a compressed air supply means 3B that supplies compressed air into the fuel activation chamber 3 during acceleration of the internal combustion engine.

As shown in FIG. 1 as an example, this compressed air supply means 38 includes a pump 39 that compresses a part of clean air obtained through an air cleaner or the like, and a pump 39 that stores the air compressed by the pump. a conduit 41 for guiding compressed air from the tank to the fuel activation chamber 3;
a normally closed solenoid valve 42 interposed in the middle of the solenoid valve 1;
2 and a solenoid valve control section 43 that controls opening and closing as appropriate.

The pump 39 is driven by power transmitted from a crankshaft (not shown).

The solenoid valve control unit 43 opens the solenoid valve 42 to open the fuel activation chamber 3 when the internal combustion engine is being accelerated (hereinafter referred to as acceleration time) or when a load is applied to the internal combustion engine (hereinafter referred to as Kaga loading time). It is operated to send compressed air to.

In this example, by utilizing the fact that the control rack 44a of the fuel supply pump 44 is largely moved in one direction when the internal combustion engine is accelerated or under load, the actuator of the switch 45 is pressed by the operation of the control rack 44a. The switch is opened, thereby allowing operating current to flow from the battery 46 to the solenoid valve 42 via the switch 45.

In addition, 47 is a check valve interposed in the middle of the conduit 4B connecting the pump 39 and the tank 40 to prevent the compressed air from flowing back from the tank 40 to the pump 39 side, and 49 is a check valve that is interposed in the middle of the conduit 4B that connects the pump 39 and the tank 40. This is a relief valve to maintain a constant value.

Furthermore, when installing the compressed air supply means 38, compressed air may be directly supplied to the fuel activation chamber 3 as shown in FIG. It is preferable to supply the fuel so that it is ejected in the same direction as B and in the tangential direction, for example, from the hole 23 or the fuel supply hole 18, or from any point between the hole 23 and the fuel supply hole 18. It is better to supply it from

Next, let's summarize the characteristic actions of the internal combustion engine:
It is as follows.

1) Early activation of the injected fuel The fuel is injected from the fuel injection nozzle J7 into a fuel activation chamber 3 containing high-temperature residual gas and having a wall surface heated to a high temperature.
The compressed air introduction hole 18
It flows in from a, is premixed with compressed air, and further swirls in the fuel activation chamber 3 and is forcibly preheated by the residual gas, the hot wall surface, the glow plug 19, etc., to form a uniform air-fuel mixture. Note that if the compressed air introduction hole 18a is made too large, self-ignition will occur in the fuel activation chamber 3, resulting in so-called diesel combustion, so it is preferable to set the diameter of the compressed air introduction hole 18a relatively small.

2) Control of ignition timing by valve 4 Valve body 10 of valve 13 provided near fuel activation chamber 3
The uniformly activated (premixed, preheated) air-fuel mixture between the upper surface 10a of the valve element 10 and the ceiling surface 3a of the fuel activation chamber 3 is moved between the upper surface 10a of the valve element 10 and the ceiling surface 3a of the fuel activation chamber 3 by pulling up the valve element IO. A squish action is applied by the surface 3a, and the air is violently injected into the main combustion chamber 2 from the opened valve 13, and immediately ignites and burns when it comes into contact with fresh air in the main combustion chamber.

In this way, in the internal combustion engine, essentially the spark plug 2
Since ignition combustion can be performed by opening the valve 13 without using one spark, the ignition plug 21 can also be omitted.

Furthermore, in the case of a configuration using the ignition plug 21, even if fuel that is difficult to activate or ignite is used, it is possible to reliably ignite it at a predetermined timing.

Therefore, whether or not to adopt the configuration using the spark plug 21 may be determined as appropriate by considering the type of fuel, its properties, the purpose of use of the internal combustion engine, and the like.

As is clear from the above, in the internal combustion engine, the ignition timing can be optimally controlled by appropriately selecting and changing the opening/closing timing of the valve 13 and/or the spark timing of the ignition plug 21.

In addition, when the configuration is such that ignition is caused by the spark of the ignition plug 21, the timing of emitting the spark of the ignition plug 21 is preferably synchronized with the opening timing of the valve 13.

In addition, since the timing of opening and closing of the valve 10 can be controlled, the fuel supply time can also be controlled, so that the fuel and air can be premixed and preheated and activated sufficiently in the fuel activation chamber 3. Fuel can be gasified in an optimal state suitable for various internal combustion engines. Therefore, various types of fuel can be used, and it can also be used in internal combustion engine PQ (including not only diesel engines but also ordinary gasoline engines).

3) Premixed combustion due to activation Achieves quiet premixed combustion without causing the diesel knock that is characteristic of diesel combustion, produces little exhaust gas, and in particular, almost no black smoke is seen.As a result, high speed rotation is possible. Since the compression ratio can also be lowered slightly, it is expected that the weight of the engine will be reduced. Furthermore, since the excess air ratio can be brought close to 1.0, it is also possible to improve the output.

In the present invention, the holder 4 may of course be installed at the center of the piston 6.

Further, the shape of the recess 7 of the piston 6 is not limited to a substantially hemispherical shape, but may be any shape such as a substantially cylindrical shape.

Furthermore, the grooves 31 and 32 of the valve body lO, the air amount adjustment device 26
, the groove 35 of the piston 6, and the compressed air supply means 38 may be omitted, or may be added selectively and appropriately in consideration of the intended use of the internal combustion engine 1.

Furthermore, if at least the wall surface surrounding the fuel activation chamber 3 or the entire holder 4 is formed using a ceramic material, the thermal efficiency of the internal combustion engine can be improved, and it is preferable.
In addition, the entire structure may be formed from a ceramic material.

Further, in the above embodiment, the compressed air introduction hole 18a is configured as a hole that connects the main combustion chamber 2 with the middle of the fuel supply hole 18, but the present invention is not limited to this, and the compressed air introduction hole 18a is configured as Any configuration may be used as long as it is suitable.

e. Detailed Description of the Invention As described in detail, in the present invention, the fuel activation chamber is formed in a holder formed separately from the cylinder head, and furthermore, a large holder fitting hole with a stepped portion approximately in the center is formed in the holder. The cylinder head is formed eccentrically with respect to the main combustion chamber to the extent that a portion overlaps with the inner circumferential edge of the cylinder block, and a stepped portion corresponding to the stepped portion of the holder insertion hole is formed in the holder, Therefore, when the holder is fitted into the holder fitting hole, the holder is fixed by the stepped part of the holder fitting hole of the cylinder head and the inner peripheral edge of the cylinder block. No fastening means such as bolts are required to fix the holder to the cylinder head, and therefore the fixing structure of the holder becomes simple and the number of parts required for the fixing structure can be reduced. It is economical because assembly is easy and costs are low.

[Brief explanation of the drawing]

1 to 4 show an embodiment of a piston structure for an internal combustion engine according to the present invention, FIG. 1 is a conceptual sectional view thereof, FIG. 2 is an enlarged sectional view of the main parts, and FIG. The figure is an enlarged sectional view of the main part, and FIG. 4 is a plan view showing the piston structure. 1... Internal combustion engine, 2... Main combustion chamber, 3...
fuel activation chamber, 4... holder, 4c... stepped portion,
5... recess, 6... piston,
7... (hollow, 8... cylinder head, 8c...
・Stepped portion, 10... Valve body, 11... Rondo, 12... Valve seat, 13... Valve, 14.
...Tapeft, 15...Spring, 16...
・Cam, 17...Fuel injection nozzle, 18, 18a...
・Hole, 19... Glow plug, 20... Female screw hole, 21... Spark plug, 22... Hole,
23.24.25... Hole, 26... Air amount adjustment device, 27... Small rod, 27a... Inclined portion, 28... Rotating means, 31, 32... Groove,
33... Cylinder block, 34-... Liner, 35... Guide groove. Figure 2 Figure 3 Figure 4 Procedure Nefu Tadashi Shoko November 13, 1985 1, Display of the case 1988 Patent Application No. 11984 4, Agent 107 Address Akasaka, Minato-ku, Tokyo 3-chome-2-3-5, "Detailed Description of the Invention" column of the specification subject to amendment. Contents of the amendment 1) The following sentence is inserted between page 18, line 12 and line 13 of the specification of the present application. Note that the internal combustion engine 1 may be configured to include a valve control means (not shown) that opens and closes the valve 13 at the ignition timing when rotating at low speeds, and keeps it open when rotating at medium speeds or higher. . The valve control means is, for example, a mechanism that detects the rotation speed and stops the cam 16 to open the valve 13 when the rotation speed reaches a medium speed. Since such a mechanism can be easily constructed by using a conventionally well-known speed detection sensor, a control device using a microcomputer, etc., detailed explanation thereof will be omitted. Note that the mechanism of this valve control means is, of course, not limited to the one described above;
Any configuration may be used as long as the valve 13 can be kept open at medium speed or higher. In the valve control means in this embodiment, the medium speed means:
Although it is preferable to set it within the range of 1500 to 2000 rpm, the present invention is not particularly limited to this, and may be determined as appropriate in consideration of the type, performance, purpose of use, etc. of the internal combustion engine to which the present invention is applied. good. By using such a valve control means, non-king can be effectively prevented at low to medium speeds, and
Smooth high-speed operation can be achieved at medium to high speeds.

Claims (1)

[Claims] In an internal combustion engine having a fuel activation chamber in the vicinity of a main combustion chamber, and a valve between the fuel activation chamber and the main combustion chamber for opening and closing the space therebetween, the valve body is connected to the fuel activation chamber. The fuel activation chamber is configured to open when moved to the side, and is formed in a holder formed separately from the fuel activation chamber cylinder head, and further includes a holder insertion hole with a stepped portion approximately in the center. The cylinder head is formed eccentrically with respect to the main combustion chamber to the extent that the part overlaps with the inner circumferential edge of the cylinder block, and a stepped part corresponding to the stepped part of the holder insertion hole is formed in the holder. , when the holder is inserted into the holder insertion hole,
An internal combustion engine, wherein the holder is fixed by a stepped portion of the holder fitting hole of the cylinder head and an inner circumferential edge of the cylinder block.