JP2019019707A - Fuel supply system for internal combustion engine - Google Patents

Abstract

To suppress occurrence of icing at a fuel collision portion on an inner wall surface of an intake port and promote vaporization of fuel.SOLUTION: An internal combustion engine 10 includes: a cylinder head 12 having an intake port 13; and an intake manifold 15 having an intake passage section 16 communicated with the intake port 13. A water jacket 18 located adjacent to the intake port 13 is formed in the cylinder head 12. A fuel supply system 30 includes an injector 32 provided in the intake manifold 15 and injecting fuel into the intake port 13 to cause the fuel to collide with an inner wall surface 13a of the intake port 13. The injector 32 is disposed so that an intersection point P of a fuel injection center line L to the inner wall surface 13a is located downstream of a position B on a cylinder opposite side in a partition wall section 20 between the intake port 13 and the water jacket 18 of the cylinder head 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel supply device for an internal combustion engine.

  2. Description of the Related Art Conventionally, a fuel supply device for an internal combustion engine has been provided with an intake manifold having an intake passage communicating with an intake port of a cylinder head of the internal combustion engine, and the intake manifold is provided with an injector for injecting fuel into the intake port (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 2006-121614

  In Patent Document 1, the injector is disposed such that the fuel injection center line faces the umbrella portion of the intake valve. For this reason, the fuel injected from the injector does not collide with the inner wall surface of the intake port. Therefore, fuel diffusion is not promoted, and fuel vaporization cannot be promoted. In order to diffuse the fuel, the fuel injected from the injector may collide with the inner wall surface of the intake port. However, when the fuel is liquid fuel, for example, liquefied gas fuel, the fuel collision site on the inner wall surface of the intake port is cooled by the latent heat of vaporization of the fuel. For this reason, icing, that is, icing occurs due to icing of moisture in the intake air at the fuel collision site.

  The problem to be solved by the present invention is to provide a fuel supply device for an internal combustion engine that can suppress the occurrence of icing at the fuel collision site on the inner wall surface of the intake port and promote the vaporization of fuel.

  The above-described problem can be solved by the fuel supply device for an internal combustion engine of the present invention.

  A first invention includes an intake manifold having an intake passage communicating with an intake port of a cylinder head of an internal combustion engine. The intake manifold injects fuel into the intake port and an inner wall surface of the intake port. A fuel supply device for an internal combustion engine, wherein a water jacket adjacent to the intake port is formed on the cylinder head, wherein the injector is a fuel collision side of the intake port An internal combustion engine is disposed such that the intersection of the fuel injection center line with respect to the inner wall surface of the cylinder head is located downstream of the position on the opposite cylinder side of the partition wall portion between the intake port and the water jacket of the cylinder head. An engine fuel supply device.

  According to the first invention, on the inner wall surface of the intake port on the fuel collision side, the downstream side of the partition wall portion between the intake port of the cylinder head and the water jacket is located on the downstream side as compared with the upstream side. It is close to the combustion chamber and becomes hot. For this reason, generation | occurrence | production of the icing in the fuel collision site | part of the inner wall face of an intake port can be suppressed, and fuel vaporization can be accelerated | stimulated.

  A second invention is the fuel supply apparatus for an internal combustion engine according to the first invention, wherein the intersection point is arranged on the downstream side of the cylinder side position of the partition wall portion.

  According to the second invention, on the inner wall surface of the intake port on the fuel collision side, the downstream side of the partition wall portion on the cylinder side is closer to the combustion chamber than the upstream side. For this reason, the temperature rises quickly even when the coolant temperature in the water jacket is low immediately after the internal combustion engine is started. Therefore, it is possible to suppress the occurrence of icing at the fuel collision site on the inner wall surface of the intake port immediately after the internal combustion engine is started.

  A third invention is the fuel supply apparatus for an internal combustion engine according to the first or second invention, wherein the fuel is a liquid fuel.

  According to the third invention, even if the fuel is easily vaporized and icing is liable to occur, the occurrence of icing at the fuel collision site on the inner wall surface of the intake port can be effectively suppressed.

  A fourth invention is the fuel supply device for an internal combustion engine according to any one of the first to third inventions, wherein a heat insulating member is interposed between the cylinder head and the intake manifold.

  According to the fourth invention, heat transfer from the cylinder head to the intake manifold is suppressed by the heat insulating member. For this reason, while increasing the temperature of the cylinder head immediately after starting the internal combustion engine, it is possible to suppress the temperature increase of the intake manifold and to suppress the vaporization of the fuel in the injector.

  According to the fuel supply device for an internal combustion engine of the present invention, it is possible to suppress the occurrence of icing at the fuel collision portion on the inner wall surface of the intake port and promote the vaporization of the fuel.

It is sectional drawing which shows the fuel supply apparatus of the internal combustion engine concerning one Embodiment.

  Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. In the present embodiment, a fuel supply device that injects and supplies liquefied petroleum gas (LPG), which is liquid fuel, to an internal combustion engine is exemplified. FIG. 1 is a cross-sectional view showing a fuel supply device for an internal combustion engine. In FIG. 1, the upper side corresponds to the sky direction, and the lower side corresponds to the ground direction.

[Configuration of Fuel Supply Device for Internal Combustion Engine]
As shown in FIG. 1, the internal combustion engine 10 includes a cylinder head 12 having an intake port 13 and an intake manifold 15 having an intake passage portion 16 communicating with the intake port 13. A water jacket 18 adjacent to the intake port 13 is formed in the cylinder head 12. A wall portion between the intake port 13 and the water jacket 18 is referred to as a partition wall portion 20. Cooling water (engine cooling water) W can be circulated in the water jacket 18.

  The intake manifold 15 has a plurality of intake passage portions 16 (one is shown in FIG. 1) corresponding to each cylinder of the internal combustion engine 10. An injector mounting portion 22 is formed on the upper surface side of the downstream end portion of the intake manifold 15. A fitting recess 23 corresponding to the intake passage portion 16 is formed in the injector mounting portion 22. The upstream end of the intake manifold 15 is connected to a surge tank (not shown).

  A plate-like gasket 25 is interposed between the cylinder head 12 and the intake manifold 15. The gasket 25 is made of resin, for example, phenol resin, and has heat insulation properties. The gasket 25 is formed with a through hole 26 penetrating in the thickness direction. The intake passage portion 16 of the intake manifold 15 is communicated with the intake port 13 of the cylinder head 12 through the through hole 26 of the gasket 25. The intake manifold 15, the gasket 25, and the cylinder head 12 correspond to an “intake passage forming member” in the present specification. The intake passage portion 16, the intake port 13, and the through hole 26 correspond to the “intake passage” in this specification. The gasket 25 corresponds to a “heat insulating member” in this specification.

  The fuel supply device 30 includes an injector 32 that injects fuel into the intake port 13 of the cylinder head 12. The injector 32 is provided in the intake manifold 15. That is, the tip end portion (fuel injection side end portion) of the injector 32 is fitted in the fitting recess 23 of the injector mounting portion 22. The base end portion of the injector 32 is connected to a delivery pipe (not shown). The delivery pipe distributes fuel supplied from a fuel pump (not shown) to each injector 32. A fuel injection port 33 positioned coaxially is provided on the tip end side of the injector 32. The injector 32 injects fuel from the fuel injection port 33 toward the axial front side (downward and diagonally right in FIG. 1).

  A fuel injection passage 35 is formed in the intake manifold 15. The fuel injection passage 35 is formed in a hollow cylindrical shape having the same axis as the axis of the injector 32, that is, the injection center line L of the fuel injected from the injector 32. The fuel injection center line L is inclined toward the intake port 13 from the injector 32 side. The injector 32 injects fuel into the intake port 13 through the fuel injection passage 35 and collides with the inner wall surface of the intake port 13, specifically, the inner wall surface 13 a on the lower surface side. The fuel spray F injected from the fuel injection passage 35 has a conical shape with the outlet of the fuel injection passage 35 as a vertex.

  In the injector 32, the intersection P of the fuel injection center line L with respect to the inner wall surface 13 a on the fuel collision side of the intake port 13 is a cylinder side position A in the partition wall portion 20 between the intake port 13 of the cylinder head 12 and the water jacket 18. It arrange | positions so that it may be located in the downstream (back side) rather than. In this embodiment, the fuel spray F on the inner wall surface 13a on the fuel collision side of the intake port 13 is set so as to be located downstream of the position A on the cylinder side as a whole or substantially entirely.

[Operation and effect of fuel supply system]
The fuel injected from the injector 32 is injected toward the inner wall surface 13 a of the intake port 13 of the cylinder head 12 through the fuel injection passage 35. The fuel collides with the inner wall surface 13 a of the intake port 13 and is diffused. The fuel injected into the intake port 13 and the diffused fuel are mixed with the intake air while being vaporized while taking heat from the intake air. The air-fuel mixture is supplied to the combustion chamber of the internal combustion engine 10 and burned.

  Further, in the inner wall surface 13a on the fuel collision side of the intake port 13, the downstream side of the cylinder side position A in the partition wall portion 20 between the intake port 13 of the cylinder head 12 and the water jacket 18 is compared with the upstream side thereof. Close to the combustion chamber and become hot. For this reason, generation | occurrence | production of the icing in the fuel collision site | part of the inner wall surface 13a of the intake port 13 can be suppressed, and fuel vaporization can be accelerated | stimulated. As a result, combustion is improved, fuel consumption can be improved, and exhaust gas emission can be improved. Further, since it is not necessary to add a special device or control device, it is possible to suppress the occurrence of icing at the fuel collision portion of the inner wall surface 13a of the intake port 13 at a low cost.

  Further, on the inner wall surface 13a on the fuel collision side of the intake port 13, the downstream side of the partition wall portion 20 from the cylinder side position A is closer to the combustion chamber than the upstream side. For this reason, the temperature rises quickly even when the temperature of the cooling water W in the water jacket 18 is low immediately after the internal combustion engine 10 is started. Therefore, it is possible to suppress the occurrence of icing at the fuel collision portion of the inner wall surface 13a of the intake port 13 immediately after the internal combustion engine 10 is started.

  Further, even if the fuel is a liquid fuel that is easily vaporized and easily icing, the occurrence of icing at the fuel collision portion of the inner wall surface 13a of the intake port 13 can be effectively suppressed.

  Further, heat transfer from the cylinder head 12 to the intake manifold 15 is suppressed by the gasket 25 interposed between the cylinder head 12 and the intake manifold 15. For this reason, it is possible to suppress the temperature increase of the intake manifold 15 while suppressing the temperature increase of the cylinder head 12 immediately after the internal combustion engine 10 is started, and to suppress the vaporization of fuel in the injector 32.

[Other Embodiments]
The present invention is not limited to the above-described embodiments, and modifications can be made without departing from the present invention. For example, liquefied gas fuel such as liquefied natural gas (LNG) may be used as the liquid fuel. Further, the intersection P of the fuel injection center line L with respect to the inner wall surface 13a on the fuel collision side of the intake port 13 is more than the position on the opposite cylinder side of the partition wall portion 20 (the position opposite to the cylinder side position A) B It only has to be on the downstream side (back side). That is, the intersection point P may be disposed between the position B on the opposite cylinder side and the position A on the cylinder side. Further, the fuel injection passage 35 may be omitted, and the fuel may be directly injected from the injector 32 into the intake port 13.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Cylinder head 13 Intake port 13a Inner wall surface 15 Intake manifold 16 Intake passage part 18 Water jacket 20 Partition part 25 Gasket (heat insulation member)
30 Fuel supply device 32 Injector L Fuel injection center line P Intersection A Cylinder side position B Non-cylinder side position

Claims (4)

An intake manifold having an intake passage communicating with an intake port of a cylinder head of an internal combustion engine;
The intake manifold is provided with an injector that injects fuel into the intake port and collides with an inner wall surface of the intake port;
A fuel supply device for an internal combustion engine, wherein a water jacket adjacent to the intake port is formed in the cylinder head,
In the injector, the intersection of the fuel injection center line with the inner wall surface on the fuel collision side of the intake port is downstream of the position on the opposite cylinder side in the partition between the intake port and the water jacket of the cylinder head. A fuel supply device for an internal combustion engine, disposed so as to be located in A fuel supply device for an internal combustion engine according to claim 1,
The fuel supply device for an internal combustion engine, wherein the intersection is disposed downstream of a position of the partition wall on the cylinder side. A fuel supply device for an internal combustion engine according to claim 1 or 2,
The fuel supply device for an internal combustion engine, wherein the fuel is a liquid fuel. A fuel supply device for an internal combustion engine according to any one of claims 1 to 3,
A fuel supply device for an internal combustion engine, wherein a heat insulating member is interposed between the cylinder head and the intake manifold.

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