JP7350533B2 - Fuel injection valve and internal combustion engine equipped with the fuel injection valve - Google Patents

Description

The present invention relates to a fuel injection valve that injects fuel into an internal combustion engine, and an internal combustion engine equipped with the fuel injection valve.

As a conventional fuel injection valve, it is attached to the cylinder head of an internal combustion engine (for example, a gasoline engine) by being inserted into a mounting hole formed in the cylinder head and communicating with the combustion chamber, and injects fuel directly into the combustion chamber. There is something. In such a fuel injection valve, a seal ring made of fluororesin or the like is provided around the outer periphery of the tip, and when the tip is press-fitted into the mounting hole, combustion gas from the combustion chamber of the cylinder is sealed. A device configured to be sealed by a ring has been proposed (for example, see Patent Document 1).

Japanese Patent Application Publication No. 2010-150976

The fuel injection valve described in Patent Document 1 is attached to the cylinder head so that its tip portion faces the combustion chamber, so the tip portion is exposed to combustion gas in the combustion chamber and becomes high temperature. Therefore, there is a possibility that the seal ring provided around the outer periphery of the tip of the fuel injection valve may be heated excessively and the temperature may rise, causing it to melt or to accelerate deterioration. On the other hand, if the tip of the fuel injector is placed in the mounting hole outside the combustion chamber to prevent the seal ring from being excessively heated, the tip of the fuel injector will be less likely to be heated, reducing the temperature rise of the seal ring. However, if fuel adheres to the tip, it becomes difficult to evaporate the fuel, and there is a risk that the number of PN (Particulate Number: PM) particles in the internal combustion engine will increase. There is.

The present invention has been made against the background of the above-mentioned problems, and improves a fuel injection valve and an internal combustion engine to which the fuel injection valve is attached, while reducing the temperature drop of an injection part that injects fuel into a fuel chamber of an internal combustion engine. It is an object of the present invention to provide a fuel injection valve that can reduce the temperature rise of a seal portion that seals between the cylinder head and the cylinder head. Another object of the present invention is to provide an internal combustion engine including such a fuel injection valve.

The fuel injection valve according to the present invention includes:
Fuel comprising a nozzle part (36) that is inserted into a mounting hole (26) formed in a cylinder head (22) of an internal combustion engine (10) and injects fuel directly into a combustion chamber (21) of the internal combustion engine (10). In the injection valve (30),
The nozzle part (36) is
an injection part (32) provided with an injection hole (31) for injecting fuel into the combustion chamber (21) of the internal combustion engine (10);
a seal portion (35) that seals combustion gas between the inner periphery of the mounting hole (26) and the outer periphery of the fuel injection valve (30);
a thick part (34) formed between the injection part (32) and the seal part (35);
a thin wall portion (33) formed between the injection portion (32) and the seal portion (35), the wall thickness being thinner than the thick wall portion (34);
Equipped with.

According to the fuel injection valve according to the present invention, in the fuel injection valve that directly injects fuel into the combustion chamber, a thin wall portion and a thick wall portion are provided between the injection portion and the seal portion, and the thin wall portion is Thermal resistance is higher than that of the thick walled part, and it acts as a barrier to heat transfer from the injection part to the seal part, so even if the temperature of the injection part rises, heat will not transfer from the injection part to the seal part. It is possible to reduce the temperature rise in the sealing part. In addition, the thin-walled portion has a higher thermal resistance than the thick-walled portion and acts as a barrier to heat transfer from the injection part side to the sealing part side, so when the injection part is heated by combustion gas, the injection part It is possible to make it easier for heat to stay in the area, and it is possible to reduce the temperature drop in the injection part.

The internal combustion engine according to the present invention includes:
Fuel comprising a nozzle part (36) that is inserted into a mounting hole (26) formed in a cylinder head (22) of an internal combustion engine (10) and injects fuel directly into a combustion chamber (21) of the internal combustion engine (10). In the injection valve (30),
The nozzle part (36) is
an injection part (32) provided with an injection hole (31) for injecting fuel into the combustion chamber (21) of the internal combustion engine (10);
a seal portion (35) that seals combustion gas between the inner circumference of the mounting hole (26) and the outer circumference of the fuel injection valve (30);
a thick part (34) formed between the injection part (32) and the seal part (35);
a thin wall portion (33) formed between the injection portion (32) and the seal portion (35), the wall thickness being thinner than the thick wall portion (34);
A fuel injection valve (30) is provided.

According to the internal combustion engine according to the present invention, in the fuel injection valve that directly injects fuel into the combustion chamber of the internal combustion engine, the thin wall portion and the thick wall portion are provided between the injection portion and the seal portion. has a higher thermal resistance than the thick walled part and acts as a barrier to heat transfer from the injection part to the seal part, so even if the temperature of the injection part rises, heat will not transfer from the injection part to the seal part. This can reduce the movement of the air and reduce the temperature rise in the sealing part. In addition, the thin-walled portion has a higher thermal resistance than the thick-walled portion and acts as a barrier to heat transfer from the injection part side to the sealing part side, so when the injection part is heated by combustion gas, the injection part It is possible to make it easier for heat to stay in the injector, thereby reducing the temperature drop in the injection part.

Note that the present invention may have only the matters specifying the invention described in the claims of the present invention, or may have configurations other than the matters specifying the invention together with the matters specifying the invention described in the claims of the present invention. It may be something.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining an internal combustion engine including a fuel injection valve according to an embodiment. It is a side view of the fuel injection valve concerning an embodiment. FIG. 3 is a side sectional view of the tip portion of the fuel injection valve according to the embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of embodiments of a fuel injection valve and an internal combustion engine equipped with the fuel injection valve according to the present invention will be described below with reference to the drawings. Note that the configuration, operation, etc. of the embodiment described below are merely examples, and the present invention is not limited to such a configuration, operation, etc. Further, below, the same or similar explanations are simplified or omitted as appropriate. Furthermore, in each figure, the same or similar members or portions are omitted or given the same reference numerals. Furthermore, detailed structures are simplified or omitted as appropriate.

The fuel injection valve according to this embodiment can be applied as a fuel injection valve that injects fuel in an internal combustion engine (eg, a gasoline engine, a diesel engine, etc.). Further, an internal combustion engine provided with the fuel injection valve according to the present invention is an internal combustion engine that uses gasoline as fuel, and can be applied as an internal combustion engine for vehicles, power generators, etc., for example. In this embodiment, a gasoline internal combustion engine for a vehicle will be described as an example of the internal combustion engine, but the present invention is not particularly limited to this.

<Embodiment>
[About internal combustion engines]
The configuration of an internal combustion engine 10 according to this embodiment will be explained based on FIG. 1.

As shown in FIG. 1, the internal combustion engine 10 includes an engine body 20 forming a combustion chamber 21, a fuel injection valve 30 injecting fuel into the combustion chamber 21, a spark plug 40 discharging sparks into the combustion chamber 21, and a combustion chamber 21. An intake valve 50 that opens and closes the combustion chamber 21 with respect to the intake passage 24, an exhaust valve 60 that opens and closes the combustion chamber 21 with respect to the exhaust passage 25, and a piston that operates linearly as the mixture of fuel and air burns in the combustion chamber 21. 70, a connecting rod 80 and a crankshaft (not shown) that convert linear operation of the piston 70 into rotational movement, and a fuel supply device that supplies fuel from a fuel tank (not shown) in which fuel is stored to the fuel injection valve 30. (not shown) etc.

The engine body 20 includes a cylinder head 22 and a cylinder block 23, and the cylinder head 22 and cylinder block 23 form a combustion chamber 21. The cylinder head 22 has a first mounting hole 26 and a second mounting hole 27 that communicate with the combustion chamber 21 from the outside of the cylinder head 22 . Further, in the first mounting hole 26, a large diameter portion 26a is formed on the outer surface side of the cylinder head 22, and a large diameter portion 26a is formed on the combustion chamber side continuously with the large diameter portion 26a and has a smaller diameter than the large diameter portion 26a. A small diameter portion 26b is formed (see FIG. 2). A fuel injection valve 30 is inserted into the first mounting hole 26, and a spark plug 40 is inserted into the second mounting hole 27.

The fuel injection valve 30 is inserted into the first mounting hole 26 so that an injection part 32 provided with an injection hole 31 for injecting fuel faces the combustion chamber 21, and directly injects fuel into the combustion chamber 21. Furthermore, as will be described later, a seal portion 35 is provided on the outer periphery of the tip portion of the fuel injection valve 30, which closes the gap between the fuel injection valve 30 and the first mounting hole 26, and seals the combustion chamber 21. is configured to seal off combustion gases from the

The first mounting hole 26 and the second mounting hole 27 are provided in the cylinder head 22 between the mounting position of the intake valve 50 and the mounting position of the exhaust valve 60. is provided in the cylinder head 22 between the intake valve 50 and the exhaust valve 60.

[About fuel injection valve]
The configuration of the fuel injection valve 30 according to this embodiment will be explained based on FIGS. 1 to 3.

As shown in FIGS. 1 and 2, the fuel injection valve 30 has a base end 38 connected to a delivery pipe (not shown) to which fuel is supplied from a fuel supply device, and an injection valve that injects fuel into the combustion chamber 21. A nozzle part 36 having a spray part 32 in which a hole 31 is formed at the tip thereof is provided. The fuel injector 30 is inserted into the first mounting hole 26 such that the base end 38 side is located at the large diameter portion 26a of the first mounting hole 26, and the nozzle portion 36 side is located at the small diameter portion 26b. .

As shown in FIG. 2, a protrusion 37 that protrudes toward the outer peripheral surface from the central axis CF of the fuel injection valve 30 is provided at the end of the base end 38 on the combustion chamber 21 side. The protrusion 37 has a contact surface 37a that contacts the cylinder head 22 when the fuel injection valve 30 is attached to the cylinder head 22. The fuel injection valve 30 is fixed to the cylinder head 22 and the delivery pipe by being held between the cylinder head 22 and the delivery pipe, which are in contact with each other through the contact surface 37a.

When the fuel injection valve 30 is inserted into the first mounting hole 26 and fixed to the cylinder head 22, the injection part 32 at the tip of the nozzle part 36 is inserted from the opening of the first mounting hole 26 on the combustion chamber 21 side. The fuel injector 30 is positioned within the combustion chamber 21 without protruding into the combustion chamber 21, and the fuel injection valve 30 is positioned so that the tip of the injection part 32 matches the wall surface of the combustion chamber 21 around the opening A of the first mounting hole 26. is fixed to the cylinder head 22.

In the nozzle portion 36, a seal portion 35 for sealing combustion gas from the combustion chamber 21 is provided between the injection portion 32 in which the injection hole 31 is formed and the end portion on the base end portion 38 side. In the seal portion 35, a groove 35a is formed in the circumferential direction on the outer peripheral surface of the nozzle portion 36 (see FIG. 3), and an elastic resin material such as polytetrafluoroethylene, so-called Teflon, is formed on the inner peripheral surface of the groove 35a. A sealing member 35b made of a fluororesin such as (registered trademark) is arranged in an annular shape. When the fuel injection valve 30 is inserted into the first mounting hole 26 and the nozzle portion 36 is press-fitted into the small diameter portion 26b of the first mounting hole 26, the seal member 35b is compressed in the radial direction and the nozzle The inner circumferential surface of the groove 35a of the portion 36 and the inner circumferential surface of the first mounting hole 26 are closely contacted to form a seal to prevent combustion gas from flowing out from the combustion chamber 21 to the outside of the cylinder head 22.

In this embodiment, the injection part 32 at the tip of the nozzle part 36 does not protrude into the combustion chamber 21 from the opening of the first mounting hole 26 on the combustion chamber 21 side. The fuel injection valve 30 is fixed to the cylinder head 22 so that the fuel injection valve 30 is located at The fuel injection valve 30 may be fixed to the cylinder head 22 so as to be located within the combustion chamber 21. In a configuration in which the fuel injection valve 30 is fixed such that the injection part 32 is located within the first mounting hole 26, the injection part 32 is The seal portion 35 can be made less likely to be exposed to high-temperature combustion gas, and the seal portion 35 can be made less likely to be heated. On the other hand, in a configuration in which the fuel injection valve 30 is fixed such that the injection part 32 at the tip of the nozzle part 36 is located within the combustion chamber 21, compared to a configuration in which the injection part 32 is located in the first mounting hole 26. Accordingly, the injection section 32 can be more easily exposed to high-temperature combustion gas. Then, by increasing the temperature of the injection part 32 by the combustion gas, if fuel adheres to the injection part 32, the adhering fuel is vaporized, and PN (Particulate Number: PM) in the internal combustion engine is increased. The number of particles of particulate matter) can be reduced.

Next, the thermal barrier portion of the fuel injection valve 30 according to this embodiment will be explained.

As shown in FIGS. 2 and 3, in the fuel injection valve 30, there is a gap between the injection part 32 and the seal part 35 in the nozzle part 36, which acts as a barrier to the movement of heat from the injection part 32 to the seal part 35. A thin wall portion 33 and a thick wall portion 34 are provided as thermal barrier portions.

As shown in FIG. 3, the thin portion 33 is formed continuously from the injection portion 32 in the nozzle portion 36 between the injection portion 32 and the seal portion 35. As shown in FIG. The wall thickness L2 of the thin wall portion 33 is formed thinner than the wall thickness L1 of the side portion of the injection portion 32 and the wall thickness L3 of the thick wall portion 34.

The thick portion 34 is formed continuously from the thin portion 33 in the nozzle portion 36 between the injection portion 32 and the seal portion 35 . The wall thickness L3 of the thick wall portion 34 is formed to be thicker than the wall thickness L2 of the thin wall portion 33. Furthermore, a seal portion 35 is formed on the opposite side of the thick portion 34 from the thin portion 33 and continues to the thick portion 34 . Note that the thick portion 34 may be formed to be thicker than the thin portion 33 and thinner than the side portions of the injection portion 32, or may have a thickness thicker than the thin portion 33. In addition to being formed thickly, a configuration may also be adopted in which the wall thickness is thicker than the side portions of the injection portion 32 .

In the configuration in which the thin part 33 and the thick part 34 are provided between the injection part 32 and the seal part 35 in the nozzle part 36, the cross-sectional area of the thin part 33 in the axis CF direction is equal to the cross-sectional area of the thick part 34 in the axis CF direction. Due to the small area, the thermal resistance of the thin-walled portion 33 is greater than that of the thick-walled portion 34, which acts as a barrier to heat transfer from the injection section 32 side to the seal section 35 side. When the temperature of the portion 32 increases, the transfer of heat from the injection portion 32 to the seal portion 35 can be reduced, and the rise in temperature of the seal portion 35 can be reduced. Furthermore, the thin wall portion 33 has a higher thermal resistance than the thick wall portion 34 and serves as a barrier to heat transfer from the injection section 32 side to the seal section 35 side, so that the injection section 32 is heated by the combustion gas. In this case, heat can be easily retained in the injection section 32, and a drop in temperature of the injection section 32 can be reduced. This makes it easier to increase the temperature of the injection part 32, so that when fuel adheres to the injection part 32, the attached fuel can be easily vaporized.

Further, the injection part 32 is formed to have a thicker wall than the thin part 33. As a result, the injection section 32 has a large heat capacity, so that when the injection section 32 is heated by combustion gas, heat can be easily retained in the injection section 32, and a drop in temperature of the injection section 32 can be reduced. I can do it.

In the nozzle part 36, the outer diameter r1 of the injection part 32 is formed smaller than the outer diameter r4 of the seal part 35, and a predetermined distance is formed between the outer circumferential surface of the injection part 32 and the inner circumferential surface of the first mounting hole 26. A gap is created between the two. By creating a gap between the outer circumferential surface of the injection part 32 and the inner circumference of the first mounting hole 26, the combustion gas flows from the combustion chamber 21 into the space s1 of the gap, and the injection part 32 can be heated from the outer peripheral side by combustion gas, and by raising the temperature of the injection part 32 by the combustion gas, when fuel adheres to the injection part 32, the attached fuel can be vaporized.

The outer diameter r2 of the thin wall portion 33 is smaller than the outer diameter r1 of the injection portion 32 and the outer diameter r3 of the thick wall portion 34, and the outer circumferential surface of the thin wall portion 33 and the inner circumferential surface of the first mounting hole 26 A gap of a predetermined interval is created between the two. By creating a gap between the outer circumferential surface of the thin wall portion 33 and the inner circumferential surface of the first mounting hole 26, the combustion gas flows from the combustion chamber 21 into the space s2 of the gap, and the injection section 32 can be heated by combustion gas from the thin wall portion 33 side, and by raising the temperature of the injection part 32 by the combustion gas, when fuel adheres to the injection part 32, it is possible to vaporize the attached fuel. can.

The outer diameter r3 of the thick wall portion 34 is smaller than the outer diameter r4 of the seal portion 35, and a predetermined interval is formed between the outer circumferential surface of the thick wall portion 34 and the inner circumferential surface of the first mounting hole 26. A gap is created. Further, the outer diameter r3 of the thick wall portion 34 is larger than the outer diameter r2 of the thin wall portion 33, and there is a gap between the outer circumferential surface of the thick wall portion 34 and the inner circumferential surface of the first mounting hole 26. The space s3 of the gap created is smaller than the space s2 created between the thin wall portion 33 and the first attachment hole 26. A gap space s3 created between the outer peripheral surface of the thick wall portion 34 and the inner peripheral surface of the first mounting hole 26 is smaller than the space s2 created between the thin wall portion 33 and the first mounting hole 26. With this configuration, the amount of combustion gas flowing from the combustion chamber 21 into the space s3 of the gap is reduced compared to the amount of combustion gas flowing into the space s3, and the seal portion 35 formed continuously with the thick portion 34 The area of contact between the seal member 35b and the combustion gas can be reduced, and the temperature rise in the seal portion 35 can be reduced.

[About effects]
The fuel injection valve 30 according to this embodiment includes a nozzle portion 36 that is inserted into a mounting hole 26 formed in a cylinder head 22 of an internal combustion engine 10 and directly injects fuel into a combustion chamber 21 of the internal combustion engine 10. In the valve 30 , the nozzle portion 36 includes an injection portion 32 provided with an injection hole 31 that injects fuel into the combustion chamber 21 of the internal combustion engine 10 , and a combustion chamber between the inner periphery of the mounting hole 26 and the outer periphery of the fuel injection valve 30 . A seal portion 35 for sealing gas, a thick wall portion 34 formed between the injection portion 32 and the seal portion 35, and a wall thinner than the thick portion 34 between the injection portion 32 and the seal portion 35. This configuration includes a thin wall portion 33 formed therein. According to such a configuration, in the fuel injection valve 30 that directly injects fuel into the combustion chamber 21, the thin wall portion 33 and the thick wall portion 34 are provided between the injection portion 32 and the seal portion 35. The portion 33 has a higher thermal resistance than the thick portion 34 and acts as a barrier to heat transfer from the injection portion 32 side to the seal portion 35 side, so when the temperature of the injection portion 32 increases, the injection portion The transfer of heat from the seal portion 32 to the seal portion 35 can be reduced, and the temperature rise of the seal portion 35 can be reduced. Furthermore, the thin wall portion 33 has a higher thermal resistance than the thick wall portion 34 and serves as a barrier to heat transfer from the injection section 32 side to the seal section 35 side, so that the injection section 32 is heated by the combustion gas. In this case, heat can be easily retained in the injection section 32, and a decrease in temperature of the injection section 32 can be reduced.

The fuel injection valve 30 according to the present embodiment includes an injection portion 32, a seal portion 35, a thick portion 34 formed between the injection portion 32 and the seal portion 35, and a thick wall portion 34 formed between the injection portion 32 and the seal portion 35. In between, there is a thin wall portion 33 formed thinner than the thick wall portion 34, and the injection portion 32 is formed thicker than the thin wall portion 33. According to such a configuration, the injection part 32 has a larger heat capacity because it is thicker than the thin-walled part 33, so that when the injection part 32 is heated by combustion gas, heat remains in the injection part 32. It is possible to reduce the temperature drop of the injection section 32.

The fuel injection valve 30 according to this embodiment includes an injection part 32 and a seal part 35, and the outer diameter r1 of the injection part 32 is smaller than the outer diameter r4 of the seal part 35. According to such a configuration, since the outer diameter r1 of the injection part 32 is formed smaller than the outer diameter r4 of the seal part 35, when the nozzle part 36 is inserted into the mounting hole 26 of the cylinder head 22, A space s1 can be formed between the outer periphery of the injection part 32 and the inner periphery of the mounting hole 26, and combustion gas can be caused to flow into the space s1 to heat the injection part 32 from the outer periphery side. can.

The fuel injection valve 30 according to the present embodiment includes an injection part 32 and a seal part 35, and the thin part 33 is formed continuously with the injection part 32, and the outer diameter r2 of the thin part 33 is This configuration is formed to be smaller than the outer diameter r1 of the portion 32. According to such a configuration, the thin part 33 is formed continuously to the injection part 32, and the outer diameter r2 of the thin part 33 is smaller than the outer diameter r1 of the injection part 32. When the nozzle part 36 is inserted into the mounting hole 26 of the cylinder head 22, a space s2 can be formed between the outer periphery of the injection part 32 and the thin-walled part 33 and the inner periphery of the mounting hole 26. Combustion gas can be caused to flow into the space s2, and the injection part 32 can be heated by the combustion gas from the thin wall portion 33 side.

The fuel injection valve 30 according to this embodiment includes an injection part 32 and a seal part 35, and the thick part 34 is formed continuously with the thin part 33, and the outer diameter r3 of the thick part 34 is , the outer diameter r2 of the thin wall portion 33 is larger than that of the thin wall portion 33. According to such a configuration, the thick portion 34 is formed continuously with the thin portion 33, and the outer diameter r3 of the thick portion 34 is larger than the outer diameter r2 of the thin portion 33. Therefore, when the nozzle part 36 is inserted into the mounting hole 26 of the cylinder head 22, the space s3 created between the outer periphery of the thick wall part 34 and the inner periphery of the mounting hole 26 is connected to the outer periphery of the thin wall part 33. By making the space s2 smaller than the space s2 generated between the inner periphery of the hole 26 and the inner periphery of the hole 26, it is possible to reduce the area in which the combustion gas flowing into the space s3 on the outer periphery of the thin-walled portion 33 and the seal portion 35 come into contact with each other. 35 temperature rises can be reduced.

The internal combustion engine 10 according to the present embodiment includes a fuel injection valve that is inserted into a mounting hole 26 formed in the cylinder head 22 of the internal combustion engine 10 and includes a nozzle part 36 that directly injects fuel into the combustion chamber 21 of the internal combustion engine 10. 30, the nozzle part 36 has an injection part 32 provided with an injection hole 31 for injecting fuel into the combustion chamber 21 of the internal combustion engine 10, and a combustion gas between the inner periphery of the mounting hole 26 and the outer periphery of the fuel injection valve 30. a thick wall portion 34 formed between the injection portion 32 and the seal portion 35, and a wall thickness thinner than the thick portion 34 between the injection portion 32 and the seal portion 35; This configuration includes a fuel injection valve 30 having a thin wall portion 33 with a thin wall. According to such a configuration, in the fuel injection valve 30 that directly injects fuel into the combustion chamber 21 of the internal combustion engine 10, the thin wall portion 33 and the thick wall portion 34 are provided between the injection portion 32 and the seal portion 35. The thin wall portion 33 has a higher thermal resistance than the thick wall portion 34 and acts as a barrier to heat transfer from the injection section 32 side to the seal section 35 side, so when the temperature of the injection section 32 increases. In addition, the transfer of heat from the injection part 32 to the seal part 35 can be reduced, and the temperature rise in the seal part 35 can be reduced. Furthermore, the thin wall portion 33 has a higher thermal resistance than the thick wall portion 34 and serves as a barrier to heat transfer from the injection section 32 side to the seal section 35 side, so that the injection section 32 is heated by the combustion gas. In this case, heat can be easily retained in the injection section 32, and a drop in temperature of the injection section 32 can be reduced.

The internal combustion engine 10 according to the present embodiment includes a fuel injection valve 30 that directly injects fuel into the combustion chamber 21 of the internal combustion engine 10, a spark plug 40 that discharges sparks into the combustion chamber 21, and an intake passage 24 that connects the combustion chamber 21 to the combustion chamber 21. The fuel injection valve 30 and the spark plug 40 are provided between the intake valve 50 and the exhaust valve 60. This configuration is provided in the cylinder head 22 of the.

For example, when disposing the injection part 32 in the combustion chamber 21 in order to easily increase the temperature of the injection part 32 of the fuel injection valve 30 by combustion gas, the injection part 32 is placed in the small diameter part 26b of the mounting hole 26. It is necessary to provide the large-diameter portion 26a which is deeper than the case where the large-diameter portion 26a is disposed inside. However, in a configuration in which the fuel injection valve 30 and the spark plug 40 are arranged in the cylinder head 22 between the intake valve 50 and the exhaust valve 60 in the internal combustion engine 10, if the large diameter portion 26a of the mounting hole 26 is made deeper, In the cylinder head 22, the distance between the mounting hole 26 of the fuel injection valve 30 and the mounting hole 27 of the spark plug 40 becomes narrower, resulting in a thinner part of the wall, which may reduce the mechanical strength of the cylinder head 22. There is.

On the other hand, the fuel injection valve 30 of the present embodiment includes a thin wall portion 33 formed thinner than the thick wall portion 34 between the injection portion 32 and the seal portion 35. When the section 32 is heated by combustion gas, the heat can be easily retained in the injection section 32, and the temperature of the injection section 32 can be easily increased. As a result, the distance between the mounting holes 26 and 27 in the cylinder head 22 can be made relatively thick.

In addition, in this embodiment, the thin part 33 and the thick part 34 are provided between the injection part 32 and the seal part 35, and while the thin part 33 is formed continuously from the injection part 32, Although the thick part 34 is formed continuously from the thin part 33, the thick part is formed continuously from the injection part, and the thin part is formed continuously from the thick part. But it's okay. Even with such a configuration, the same effects as the present embodiment can be achieved.

Further, in this embodiment, the thin wall portion 33 and the thick wall portion 34 are provided between the injection portion 32 and the seal portion 35, but between the injection portion and the seal portion, there is a wall thinner than the injection portion. A configuration in which only a thin portion having a thickness is provided may be used. Even with such a configuration, the same effects as the present embodiment can be achieved.

Further, in the present embodiment, the thickness L2 of the thin wall portion 33 is formed thinner than the wall thickness L1 of the side portion of the injection portion 32 and the wall thickness L3 of the thick wall portion 34; The structure may be such that the wall thickness is thinner than the thick portion and the wall thickness is thicker than the side portion of the injection portion. Even with such a configuration, the same effects as the present embodiment can be achieved.

Further, in the present embodiment, in the nozzle portion 36 of the fuel injection valve 30, the outer diameter r2 of the thin wall portion 33 is formed smaller than the outer diameter r1 of the injection portion 32 and the outer diameter r3 of the thick wall portion 34. The outer diameter r3 of the portion 34 is configured to be smaller than the outer diameter r4 of the seal portion 35, but the injection portion, the thin wall portion, and the thick wall portion may each be formed to have the same outer diameter. . Even with such a configuration, the same effects as this embodiment can be achieved by forming a thick part and a thin part thinner than the thick part between the injection part and the seal part. .

Although examples of embodiments of the present invention have been described above, the present invention is not limited to these examples of embodiments, and the present invention may be modified or added without departing from the spirit of the present invention. Needless to say, it is included.

10 Internal combustion engine 21 Combustion chamber 22 Cylinder head 26 First mounting hole 27 Second mounting hole 30 Fuel injection valve 31 Injection hole 32 Injection part 33 Thin part 34 Thick part 35 Seal part 36 Nozzle part

Claims (7)

Fuel comprising a nozzle part (36) that is inserted into a mounting hole (26) formed in a cylinder head (22) of an internal combustion engine (10) and injects fuel directly into a combustion chamber (21) of the internal combustion engine (10). In the injection valve (30),
The nozzle part (36) is
An injection part (32) is provided with an injection hole (31) for injecting fuel into the combustion chamber (21), and combustion occurs between the inner periphery of the mounting hole (26) and the outer periphery of the fuel injection valve (30). a seal part (35) for sealing gas;
a thick part (34) formed between the injection part (32) and the seal part (35);
a thin wall portion (33) formed between the injection portion (32) and the seal portion (35), the wall thickness being thinner than the thick wall portion (34);
Equipped with
When the fuel injection valve (30) is inserted into the mounting hole (26), the injection part (32) is located in the mounting hole (26).
fuel injection valve. The fuel injection valve according to claim 1, wherein the injection portion (32) is formed thicker than the thin wall portion (33). The fuel injection valve according to claim 1 or 2, wherein an outer diameter (r1) of the injection part (32) is smaller than an outer diameter (r4) of the seal part (35). The thin wall portion (33) is formed continuously with the injection portion (32), and the outer diameter (r2) of the thin wall portion (33) is smaller than the outer diameter (r1) of the injection portion (32). The fuel injection valve according to claim 3, wherein the fuel injection valve is also formed small. The thick portion (34) is formed continuously from the thin portion (33), and the outer diameter (r3) of the thick portion (34) is equal to the outer diameter (r2) of the thin portion (33). ) The fuel injection valve according to claim 4, wherein the fuel injection valve is formed larger than the diameter of the fuel injection valve. An internal combustion engine comprising the fuel injection valve (30) according to any one of claims 1 to 5. The internal combustion engine (10) includes:
a spark plug (40) that discharges sparks into the combustion chamber (21);
an intake valve (50) that opens and closes the combustion chamber (21) with respect to the intake passage (24);
an exhaust valve (60) that opens and closes the combustion chamber (21) with respect to the exhaust passage (25);
Equipped with
The fuel according to claim 6, wherein the fuel injection valve (30) and the spark plug (40) are provided in a cylinder head (22) between the intake valve (50) and the exhaust valve (60). An internal combustion engine including an injection valve (30).

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