JPH03124959A - Fuel feeder for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the fuel consumption and output by providing a fuel injection valve so that the injection center line intersects the portion of the umbrella section of an intake valve on the apart side from an exhaust valve, and smoothing the surface roughness of the lower section of the inner wall hit by the fuel spray. CONSTITUTION:Fuel is injected through a fuel injection valve 33 so that the injection center line 39 intersects the portion 41 of the umbrella section 19 of an intake valve 9 on the apart side from an exhaust valve 11, and the fuel spray 35 does not collide with the umbrella section 19 on the side near the exhaust valve 11. Even at the time of the cam overlap when an intake valve 9 and the exhaust valve 11 are both opened, the fuel spray 35 is rarely discharged to an exhaust port 7 in a short circuit from the exhaust valve 11, the blow-by quantity of the unburnt HC to the exhaust port 7 is reduced, and the fuel is effectively utilized and the fuel consumption is improved. The fuel spray 35 having collided with the inner wall face of an intake port is stuck at the lower section 49 of the inner wall formed with smooth surface roughness, but it is rarely left here, it quickly flows down and is sucked to a combustion chamber 1, thus no dispersion of the air-fuel ratio occurs for each engine cycle, the operation is stabled, and the output is improved.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a fuel supply device for an internal combustion engine.

(Prior Art) There is a conventional fuel supply device as shown in FIG. 7 (see Japanese Patent Laid-Open No. 162770/1983). That is, the openings on the combustion chamber 1 side of the intake port 5 and the exhaust port 7, which are provided in the cylinder head 3 so as to face the combustion chamber 1 of the internal combustion engine, are connected to the intake valve 9 and the exhaust valve operated by a valve mechanism (not shown). 11 and are opened and closed at predetermined timing.

The fuel injection valve 13 injects fuel to be injected from now on.
Since the injection center line 17 of the injection valve 9 is provided so as to aim at the center 21 of the umbrella portion 19 of the intake valve 9, the injection center line 17 of the injection valve
Spread with the spray angle 23 so as to cover the entire area, and spray 1
5 also adheres to the umbrella portion 19 and the inner wall 25 of the intake port 5. Since the inner wall 25 of the intake port 7 is still a cast surface, the surface roughness is rough, for example, the Ra value is 200 to 300. Therefore, the fuel adhering to the inner wall 25 remains as it is and becomes a wall flow.

Furthermore, at the time of cam overlap when the intake valve 9 begins to open, the exhaust valve 11 is also open, so at this time, the injected fuel is open, as shown by the streamline 27 in FIG. It blows through to the exhaust port 7 via the exhaust valve 11.

(Problems to be Solved by the Invention) As described above, in the conventional fuel supply device, since the fuel injection center line 17 is directed toward the center line 19 of the umbrella portion 17 of the intake valve 9, the exhaust valve of the umbrella portion 19 The spray 15 near the part 29 which is very close to the 11 flows like a streamline 27 during the cam overlap and is discharged as it is from the exhaust valve 11 to the exhaust port 7, resulting in an increase in unburned HC emissions and a decrease in fuel efficiency. It is the cause.

Moreover, the spray 1 near the lower part 31 of the inner wall 25 of the intake port 5
No. 5 has a large adhesion force to the inner wall 25, which remains as a cast surface and has a rough surface, so that the spray 15 in this vicinity is not immediately sucked into the combustion chamber 1 while adhering to the surface of the cast surface as a wall flow. becomes. This wall flow causes fluctuations in the air-fuel ratio for each engine cycle, causing a worsening of combustion fluctuation rate and a decrease in output.

This invention was made by focusing on these conventional problems, and is designed to prevent fuel spray from being discharged into the exhaust system in a short-circuit manner, and to reduce adhesion to the inner wall of the intake port. The object of the present invention is to provide a fuel supply device for an internal combustion engine.

[Configuration 1 of the Invention (Means for Solving the Problems) The configuration of the present invention for solving the above problems includes an intake port and an exhaust port facing the combustion chamber, an intake valve for opening and closing each port, and υ1. In a fuel supply device for an internal combustion engine, the fuel injection valve is provided with a fuel injection valve whose injection center line is aligned with the intake valve. It is provided so as to intersect with a part of the umbrella part on the far side from the exhaust valve, and the inner wall of the intake port, which is hit by the spray from the fuel injection valve, has a smooth surface roughness at least at the lower part of the wall.

(Function) The fuel injected from the fuel injection valve is injected so that its injection center line intersects with the part of the intake valve head part that is far from the exhaust valve, and as a result, the fuel is injected into the exhaust valve of the intake valve head part. On the other hand, fuel spray is less likely to flow out on the closer side.

Therefore, even during cam overlap when both the intake valve and the exhaust valve are open, the spray injected to the far side is almost never discharged from the exhaust valve to the exhaust port in a short circuit, and the cam overlap occurs. The amount of unburned HC blown into the exhaust port 7 during the lap is extremely small, and the fuel is used effectively, improving fuel efficiency.

The spray that is injected toward the intake valve and collides with the inner wall of the intake port collides with the lower part of the inner wall, but the lower part of the wall has a smooth surface roughness, so less fuel stays. The fuel is quickly sucked into the fuel chamber, the air-fuel ratio is stabilized in each engine cycle, and the output is improved.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a vertical cross-sectional view of a main part of a fuel supply device according to a first embodiment, and FIG. 2 is a view of the main part taken in the direction of the ■ arrow in FIG.

The combustion chamber 1 side openings of the intake port 5 and the exhaust port 7, which are provided in the cylinder head 3 so as to face the combustion chamber 1, are opened in a predetermined manner by an intake valve 9 and an exhaust valve 11 operated by a valve mechanism (not shown). It opens and closes at the right time. fuel injection valve 3
3 is the fuel spray 3 that will be injected as shown in Figure 1.
The injection center line 39 of No. 5 is located at the exhaust valve 1 of the umbrella portion 19 of the intake valve 9.
It is provided so as to intersect with the lower part 41 which is the faster side with respect to 1.

As shown in FIG. 2, the cylinder head 3 has an intake valve 9.
Two exhaust valves 11 are provided respectively, and the fuel injection valve 33 has two injection ports, and the lower portion 41 of the umbrella portion 19 of both the two intake valves 9 is provided.
It is set up to aim at.

In the example shown in FIG. 2, the injection center F! 39, the mounting direction of the fuel injection valve 33 is set so as to intersect with the center 43 of the lower part 41 of the umbrella part 19, and the fuel injection valve 33 has three a and 835 injection valves.
collides with the lower portion 41 of the umbrella portion 19 at the spray angle 45 shown in FIG. 1, and is sprayed over the range of the spray surface 47 illustrated by the two-dot chain line in FIG.

Furthermore, the spray 35 of the fuel injection valve 33 also collides with the wall lower part 49 of the inner wall of the intake port 5, but the surface roughness of the wall lower part 49 is smoothed, and the collision of the spray 35 causes the wall lower part 49 to collide with the wall lower part 49. The fuel adhering to the wall 49 quickly flows down due to the smoothness of the lower wall 49 and is sucked into the combustion chamber 1.

As a method of forming the surface roughness of the lower wall portion 49 smoothly, for example, machining can be used to obtain a roughness of machine finish W (for example, Ra value of about 2.0). In Figure 2, the number 5
1 is the boundary line between the intake port 5 and the casting surface that appears by machining.

Another method for forming the wall lower part 49 with a smooth surface roughness is shown in FIG. 3 as a longitudinal cross-sectional view, and FIG. 4 as a view of the main part in the direction of the arrow ◯ in FIG. 3. In this second embodiment, a coating material 53, which is shown as a shaded area in FIG.
An alumina-based sealant with fuel resistance properties is applied. In FIG. 4, reference numeral 55 indicates a boundary line between the wall lower part 49 smoothed by the coating material 53 and the cast surface of the intake port 5.

Next, the effects of these two embodiments will be explained.

The fuel injected from the fuel injection valve 33 is aligned with the injection center line 39
is injected so as to intersect with a portion 41 of the umbrella portion 19 of the intake valve 9 that is far from the exhaust valve 11, and the exhaust valve 11 of the umbrella portion 19
The spray 35 does not collide with the side closer to . Therefore, even during cam overlap when both the intake valve 9 and the exhaust valve 11 are in the open state, the spray 35 injected to the far side part is
Short-circuit discharge from the exhaust valve 11 to the exhaust port 7 is almost eliminated, the amount of unburned HC blown into the exhaust port 7 is reduced, the degree of unburned HCl in the exhaust is significantly reduced, and the fuel is It is used effectively and improves fuel efficiency.

The spray 35 that is injected toward the intake valve 9 and collides with the inner wall of the intake port 7 adheres to the lower part 49 of the inner wall, which has a smooth surface roughness. Since it is less likely to stagnate and quickly flows down and is sucked into the combustion chamber 1, the air-fuel ratio does not vary from engine cycle to engine cycle and is stable, resulting in improved output.

A third embodiment is shown in FIG. 5 in a vertical cross-sectional view, and in FIG. It is shown in the main part view from the ■ arrow in the figure. In this third embodiment, in the lower part of the wall 49,
The shaded area in FIG. 6 is a cast material 57 shown as a part, and this casting material 57 is made of a material with high thermal conductivity so that the lower part of the wall 49 is kept at a high temperature. The structure is such that the spray 35 that collides with 49 is quickly vaporized. As the casting material 57, for example, copper is used, which has a thermal conductivity about twice that of the aluminum alloy constituting the cylinder head 3 and has a smooth surface.

Therefore, even if the spray 35 injected from the fuel injection valve 33 adheres to the wall lower part 49, the wall lower part 4 is at a high temperature due to its smooth surface and high thermal conductivity.
9, it quickly vaporizes and does not stay here,
The air-fuel ratio is sucked into the combustion chamber 1, and the air-fuel ratio does not vary from engine cycle to engine cycle and becomes stable, thereby improving output.

In FIG. 6, reference numeral 59 indicates the casting material 57 and the intake port 5.
This is the boundary line with the cast surface.

[Effects of the Invention] As is clear from the above, according to the present invention, the injection center line of the fuel spray is configured to intersect with a portion of the intake valve umbrella portion that is far from the exhaust valve, so that the intake valve umbrella The spray does not collide with the side closer to the exhaust valve, and even during cam overlap when both the intake and exhaust valves are open, the spray injected to the far side does not collide with the exhaust valve due to a short circuit. This means that the injected fuel is hardly ever discharged to the exhaust port, and the space in which the injected fuel is discharged to the exhaust port is extremely small, allowing the fuel to be used more effectively and improving fuel efficiency.

In addition, the fuel that collides with and adheres to the inner wall of the intake port, which has a smooth surface roughness, does not stay at the bottom of this wall, but quickly flows down and is sucked into the combustion chamber, resulting in a change in the air-fuel ratio for each engine cycle. becomes stable and output increases.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a fuel supply device showing a first embodiment of the present invention, FIG. 2 is a main part view as viewed from the ■ arrow in FIG. 1, and FIG. 3 is a fuel supply device showing a second embodiment of the present invention. Longitudinal sectional view of the supply device, No. 4
5 is a vertical cross-sectional view of a fuel supply system showing a third embodiment of the present invention. FIG. FIG. 7 is a longitudinal sectional view of a conventional fuel supply device. 1... Combustion v 5... Intake port 7... Exhaust port 9... Intake valve 11... Exhaust valve 19... Umbrella portion 33... Fuel injection valve 35... Spray 39.・Injection center line 41 ・Lower portion of intake valve umbrella 49 ・Lower part of the wall

Claims (1)

[Claims] Fuel for an internal combustion engine comprising an intake port and an exhaust port facing a combustion chamber, an intake valve and an exhaust valve that open and close each port, and a fuel injection valve that injects fuel toward the umbrella of the intake valve. In the supply device, the fuel injection valve is provided so that its injection center line intersects with a portion of the intake valve umbrella portion that is far from the exhaust valve, and an inner wall of the intake port that is hit by the spray from the fuel injection valve is provided. A fuel supply device for an internal combustion engine, characterized in that the surface roughness of at least the lower part of the wall thereof is smoothed.