JPS62106874A - Method for coating inner wall of suction manifold of fuel jet type engine - Google Patents

Abstract

PURPOSE:To prevent erosion due to fuel jet pressure by thickly and simply forming a resin layer to an area against which fuel impinges, by injecting a resin to the branched parts of a suction manifold from a coating nozzle so as to form a locus almost same to that of the fuel injected from a fuel jet nozzle. CONSTITUTION:A cylinder head 2 is placed alone on a mount stand 10 and a spray cover 11 is mounted to said head 2 in place of an external suction manifold having a fuel jet nozzle. The coating passage 12 communicated with an internal suction manifold 6 is formed in the spray cover and a coating nozzle 13 injecting a resin in the coating passage 12 is arranged on a straight line coinciding with the center line (l) of the spray from the fuel jet nozzle. Therefore, if the resin is injected toward the branched part 6a of the suction manifold from the coating nozzle 13 to form a smooth resin layer to the inner wall of the manifold 6, said resin follows the locus almost same to that of injected fuel and a thick resin layer having durability is formed to an area against which fuel impinges.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method of applying resin to the inner wall of an intake passage of a fuel injection engine, and particularly to a method of applying resin to the inner wall of an intake passage that branches to communicate with a plurality of intake ports. The present invention relates to a coating method for coating.

(Prior Art) Conventionally, as disclosed in Japanese Utility Model Application Publication No. 56-118931, the inner wall of an intake passage has been formed with a smooth resin layer to reduce intake resistance in engine cylinder heads. What has been done is known.

(Problems to be Solved by the Invention) By the way, in a fuel injection engine in which each cylinder is provided with a plurality of intake ports, a fuel injection nozzle is connected to each cylinder.
IIM! In the case where the fuel injection nozzle is provided separately, the fuel injection nozzle is arranged so as to inject the fuel toward a branch part of the intake passage communicating with each intake port in order to supply fuel evenly to each intake port.

However, in this case, if the inner wall of the branch portion of the intake passage is not formed smoothly, a problem arises in that a large amount of the injected fuel adheres to the branch portion, resulting in poor vaporization and atomization of the fuel.

Therefore, if the inner wall of the intake passage of such a fuel injection type engine is formed of a smooth resin layer as described above, the injected fuel will be dispersed well without adhering to the branch portion. However, when placing resin on the inner wall of the intake passage to form a resin layer, the resin on the inner wall other than the branch part is applied based on the branch part, taking into account the erosion of the resin pattern by the injected fuel. becomes too thick. However, if the resin layer is applied to areas other than the branched areas, a problem arises in that the resin layer at the branched areas quickly disappears due to the erosive action of the injected fuel.

The present invention has been made in view of the above, and its purpose is to apply a resin to the inner wall of the intake passage of a fuel-injected engine under the same conditions as the injected fuel, so that the inner wall of the branch part of the intake passage can be coated with resin. The object is to be able to apply the resin thickly and to form a resin pattern easily.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention includes a fuel injection nozzle that injects fuel toward a branch part of an intake passage communicating with a plurality of intake ports. As a method of coating the inner wall of the intake passage of an injection type engine, the fuel injection nozzle and the branch part of the intake passage are arranged in a straight line, and the coating nozzle is arranged in a straight line, and the coating nozzle is connected to the branch part of the intake passage. The resin is applied by spraying it onto the target area.

(Function) With the above configuration, in the present invention, the resin is injected from the coating nozzle toward the branching part of the intake passage in approximately the same trajectory as the fuel injected from the fuel injection nozzle. When applied, a resin layer that is thicker than other areas and has a smooth surface is easily formed on that area.

(Example) Embodiments of the present invention will be described below based on the drawings.

2 and 3 show a fuel injection engine to which a coating method according to an embodiment of the present invention is applied.

1 is a cylinder block; 2 is a cylinder head disposed on the cylinder block 1; a combustion chamber 3 is formed between the cylinder block 1 and the cylinder head 2; The combustion chamber 3 has two openings 4.4 to the intake ports 1 and one exhaust port 5. The cylinder head 2 is provided with an internal intake passage 6 whose one end is bifurcated at a branch portion 6a and communicates with each of the intake ports 4, and whose other end is open to the side surface. Further, an external intake passage 7 is attached to the side surface of the cylinder head 2 so as to communicate with the internal intake passage 6.
Intake air is supplied to the combustion chamber 3 through an internal intake passage 6. Furthermore, a fuel injection nozzle 8 is disposed in the external intake passage 7 so that the center line 9 of the spray coincides with the branch part 6a so as to inject fuel toward the branch part 6a. Note that 9 is an intake valve that opens and closes each intake port 4.

Next, a method of applying resin to the inner wall of the intake passage of this fuel injection type engine will be explained based on FIG. First, the cylinder head 2 is placed alone on a mounting table 1°, and a spray cover 11 is attached in place of the external intake passage 7.

1. The spray cover 11 has an application passage 12 formed therein that communicates with the internal intake passage 6, and
A coating nozzle 13 for spraying resin is disposed within the coating passage 12. The application nozzle 13 is positioned on a straight line (coinciding with the intersection of the center lines of the spray) connecting the fuel injection nozzle 8 and the intake passage branch 6a.

Furthermore, blind plates 14.14 for preventing resin scattering are arranged on the mounting table 10 in correspondence with the intake ports 4.4.

Next, resin is sprayed from the coating nozzle 13 toward the intake passage branch 6a to coat the inner wall of the internal intake passage 6, thereby forming a smooth resin layer on the inner wall. As the resin, a fluororesin having a property of repelling fuel is suitable, and a non-adhesive agent or the like may also be used.

Next, to explain the operation of the above embodiment, the coating nozzle 13 is arranged on the center line 9 of the spray, and the resin is injected from the coating nozzle 13 in substantially the same trajectory as the fuel injected from the fuel injection nozzle 8. As a result, a large amount of resin is applied to inner wall portions such as the internal intake passage branch portion 68 that are exposed to fuel, and a resin layer that is thicker and has a smoother surface than other portions is formed there. Due to this, when the engine is running, the branch part 6
The fuel is repelled and scattered by the resin layer 8 and mixed well with the intake air, promoting vaporization and atomization, and the smooth resin layer reduces intake resistance and reduces pumping loss. , it is possible to effectively improve the performance of the engine in terms of fuel efficiency, output, and emissions.

Moreover, since the resin layer in the area that is hit by the injected fuel is thicker than in other areas, it can sufficiently withstand erosion caused by the injection pressure, and each performance of the engine can be maintained satisfactorily for a long period of time.

Moreover, since it is sufficient to simply attach the spray cover 11 to the cylinder head 2 and cause the application nozzle 13 to spray, the work is simple and cost-effective.

Next, to explain a specific example, when a fluororesin was applied by the method of the present invention so that the average thickness of the resin layer was about 50 μm, as shown in FIG. The thickness of the resin layer formed on A is 60 to 10
0μ, and the thickness of the other part B is 20μ,
The former performance greatly outperformed the latter. Furthermore, when the roughness of the inner wall was measured, it was found to have decreased from 60μ or more before application to 7-8μ. In addition, when the average thickness was less than 10 μm, the thickness of the resin layer was approximately constant in all parts, and when it exceeded 60 μm, the resin sagged.

Furthermore, when a running test was conducted using an engine with a resin layer formed thereon, the 10-mode fuel efficiency of a 12,000 cc in-line four-cylinder engine was improved by 21%. Also, exhaust both 2000CC
The fuel efficiency was improved by 5-6% and the output was improved by 3-4% in the full load range of V type 6 cylinder engine T1500rpm.

(Effects of R Light) As explained above, according to the method of coating the inner wall of the intake passage of a fuel IlltA type engine according to the present invention, the coating nozzle flows from the coating nozzle in approximately the same trajectory as the fuel injected from the fuel injection nozzle. Since the resin is injected toward the branching part of the intake passage, it is possible to easily form a thick resin layer in the area where the fuel hits, and it also increases durability against the erosion effect caused by the fuel injection pressure of the fuel injection valve. It can vaporize and atomize fuel well over a long period of time, improving engine fuel efficiency, output,
Emission performance can be effectively improved.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory diagram showing the application process, FIG. 2 is a vertical side view of the engine, FIG. 3 is a cross-sectional view thereof, and FIG. 4 is a diagram showing test results. be. 4...Intake port, 6...Internal intake passage, 5a,...
... Branch part, 7... External intake passage, 8... Fuel injection nozzle, 13... Application nozzle. Patent applicant: 7゛7da Co., Ltd. Agent Patent attorney former 1)
Hiro's value?

Claims (1)

[Claims] (1) A method of coating an inner wall of an intake passage of a fuel injection engine equipped with a fuel injection nozzle that injects fuel toward a branch part of an intake passage communicating with a plurality of intake ports, the method comprising: An intake air of a fuel injection type engine, characterized in that a coating nozzle is arranged at a position on a straight line connecting a branching part of an intake passage, and the resin is injected from the coating nozzle toward the branching part of the intake passage for coating. How to apply to the inner wall of the passageway.