JPS603476A - Fuel supply controller - Google Patents

Abstract

PURPOSE:To improve distribution property of mixture to each cylinder to provide a stable air-fuel ratio by providing a guide plate along an intake flow between a Venturi portion of an intake path and a case for supporting a fuel injection valve. CONSTITUTION:The lower ends of guide plates 11a, 11b are formed to diverge to the right and left of an injection hole 10 so that an angle made by the lower end faces of both guide plates 11 is equalized to the maximum angle of fuel injection. Air guided from an air duct path to an intake path 1 is divided into four at a Venturi portion 6 by a stay 4a and the guide plates 11a, 11b perpendicular thereto to be conducted to the periphery of a throttle valve 5 so that the flow of intake air is put in order. Thus, the air is uniformly mixed with fuel sprayed from a fuel injection valve 2 to form a homogeneous mixture and improve distribution property to each cylinder.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a fuel supply control device that controls fuel supplied to an internal combustion engine of an automobile or the like according to operating conditions, and particularly relates to a fuel supply control device that controls fuel supplied to an internal combustion engine of an automobile or the like according to operating conditions. This invention relates to a single-point type fuel supply control device equipped with one fuel injection valve.

[Background of the invention]

A single-point fuel supply control device, which installs a fuel injection valve upstream of the throttle valve and supplies the mixture to the internal combustion engine, injects fuel in a conical shape toward the throttle valve, so there is no fuel inside the intake passage. The fuel can be distributed substantially uniformly. However, the air passing through the intake passage passes through the air cleaner and air duct passage, reaches the entrance of the intake passage, and then passes through the venturi section and is introduced around the throttle valve. The flow is not uniform due to the influence of the stay.

Therefore, the air-fuel mixture supplied to the internal combustion engine is concentrated in some places, and this spreads to the branching part of the intake manifold, deteriorating the fuel distribution to each cylinder. Another drawback is that the fuel spray injected from the fuel injection valve adheres to the lower end of the support case, grows into large fuel droplets, and falls intermittently, causing fluctuations in the air-fuel ratio of the mixture. was occurring. This will be explained using the following diagram.

FIG. 1 is a plan view of a fuel supply control device improved from the technique described in Japanese Patent Application Laid-Open No. 57-73858, and FIG. 2 is a cross-sectional view taken along line AB in FIG. At the center of the intake passage 1 and upstream of the throttle valve 5, a fuel injection valve 2 is installed and housed in a support case 6. The left and right sides of the support case 6 are connected to the venturi portion 9 by a relatively thick stay 43, and fuel passages 3a and 3b are formed therein. Further, a fuel injection hole 10 is opened at the lower end of the support case 6, and a stay 4b in the shape of a face down is installed on the upper part of the stay 4a to fix the fuel injection valve 2 within the support case 6. .

As shown in FIG. 1, the venturi portion 9 of the intake passage 1 is divided into two by stays 4a and 4b to form intake passages 1a and lb, and a bypass air passage 7 is formed in the main body on the side of the intake passage 1a. An air 70-sensor 8 is installed therein.

In the conventional device configured in this manner, the stay 4a is thick because it is necessary to form the fuel passage 3 inside the stay 4a. That is, in order to form the fuel passage 3 with a diameter of 3Tnm, the stay 4a has a thickness of more than 10m+n, so
The inspiratory flow is thereby disturbed. In addition, since the nozzle hole 10 is formed at the lower end of the thick support case 6, the intake air flow in this area is disturbed, and the spray that exits the nozzle hole 10 drifts and adheres to this area, collecting into fuel droplets. It falls on the throttle valve 5 intermittently. Therefore, the air-fuel ratio of the air-fuel mixture changes each time, which is a drawback.

FIG. 3 is an explanatory diagram of a state in which the device shown in FIG. 1 is connected to an air cleaner. Due to layout constraints in the engine compartment, Figure 3 (a)
), so the intake passage 1a
, lb flow velocities are uneven in size. Figure 3(b) shows the third
As shown in the side view of FIG. 2, such uneven intake air flow makes the air-fuel mixture distributed unevenly to each cylinder, resulting in a disadvantage that the driveability is degraded.

[Purpose of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fuel supply control device suitable for eliminating the drawbacks of the prior art described above, improving the distribution of air-fuel mixture to each cylinder, and maintaining a stable air-fuel ratio.

[Summary of the invention]

A feature of the present invention is that a thin guide plate is provided along the intake air flow between the venturi part of the intake passage and the support case of the fuel injection valve, and the lower end of this guide plate is aligned with the maximum fuel injection angle. It is about forming and becoming like that.

[Embodiments of the invention]

FIG. 4 is a plan view of a fuel supply control device which is an embodiment of the present invention, and FIG. 5 is a sectional view taken along line CD in FIG. 4. The same parts as in FIG. 1 are given the same reference numerals, but in this case, a thin guide plate 11 connects the venturi part 9 and the support case 6 in a direction perpendicular to the stay 43 forming the fuel passage 3.
a, llb are provided along the intake flow. The lower ends of these guide plates 11a and llb are formed to open in a V-shape on the left and right sides of the nozzle 10, as shown in FIG. is equal to the largest angle of . Note that a bypass air passage 7 is formed in the main body on the side of the guide plate 1a, and an air flow sensor 8 is installed in the bypass air passage 7.

The fuel supply control device configured as described above directs the air guided from the air duct passage to the intake passage 1 through the stay 4a at the venturi section 9 and the guide plates 11a and llb perpendicular to the stay 4a.
It is divided and guided around the throttle valve 5. Therefore, the flow of intake air is in a rectified state, so that it mixes uniformly with the fuel spray from the fuel injection valve 2 to form an even mixture, and is distributed to each cylinder. Sexuality improves.

FIG. 6 is a diagram comparing and showing changes in exhaust composition of a four-cylinder internal combustion engine, and the vertical axis indicates the total amount of CO, CO2, )-IC in the exhaust gas. Further, a solid line with white circles indicates the experimental values of the apparatus shown in FIG. 4 of this embodiment, and a broken line with black dots indicates the experimental values with the conventional apparatus of FIG. 1. Figure 6 (a) shows the case when the internal combustion engine is operated at 750 rpm with no load, Figure 6 (b) shows the case when the engine is operated at a speed of 40 km/h with load, and Figure 6 (C) shows 4/4 This shows the case of operation at 2000 rP.

Comparing these data shows that the device of this embodiment shown by the solid line has less change in exhaust composition and has better fuel distribution to each cylinder. Also, during the experiment, each emission,
It was recognized that output, fuel efficiency, etc. were improved. Furthermore, the phenomenon in which fuel droplets fall intermittently and disturb the air-fuel ratio of the air-fuel mixture has been improved as follows.

FIG. 7 is a diagram comparing the operability of the device shown in FIG. 1 and the device shown in FIG. 4. The broken line is the measurement record of the device shown in FIG. This is a measurement record of the device. Figure 7 (a) shows a phenomenon in which the rotational speed drops intermittently when idling at around 800 revs, but this is because fuel droplets fall and the air-fuel mixture becomes over-enriched, causing a temporary drop in drivability. It is shown that. In addition, Fig. 7(b) shows the change in exhaust gas composition in parallel with Fig. 7(a), and the data of the apparatus shown in Fig. 1 indicated by the broken line shows that CO , C02, and a small peak indicating an increase in the total amount of HC.

However, the data obtained when using the apparatus shown in FIG. 4, indicated by the solid line, is flat without producing small valleys or small peaks as described above. This indicates that no fuel dripping occurred. In addition, even in the case of the device of this embodiment, a part of the fuel spray from the jet hole 10 is transferred to the guide plate 11a,
Sometimes it adheres to the lower end of llb and forms a droplet, but since the lower end surface is inclined toward the wall of intake passage l, the fuel droplets flow down the wall and vaporize on the way. It is estimated that the Note that since the amount of fuel adhering to the vicinity of the nozzle hole 10 is very small, less than 1φ in total, even if it vaporizes while flowing along the inner wall surface, it does not have a significant effect on the air-fuel ratio of the air-fuel mixture.

The fuel supply control device of this embodiment includes a pair of thin guide plates provided along the intake flow between the venturi portion of the intake passage and the support case of the fuel injection valve to form a fuel passage to the fuel injection valve. Together with the stay, it rectifies the airflow in the intake passage. In addition, since the lower end surface of the guide plate is sloped so as to be continuous with the wall surface of the intake passage, the generation of fuel droplets adhering to the vicinity of the nozzle is suppressed, and even if they occur, they will not drip toward the throttle valve. Since the exhaust gas composition is prevented from changing, it is possible to improve the drivability and prevent fluctuations and deterioration of the exhaust gas composition.

[Effects of the Invention] The fuel supply control device of the present invention has the effect of improving and stabilizing fuel distribution to each cylinder through relatively simple modification, and improving drivability, fuel efficiency characteristics, and exhaust composition. .

[Brief explanation of drawings]

Fig. 1 is a plan view of a conventional supply fuel control device, Fig. 2 is a sectional view taken along line A-B in Fig. 1, Fig. 3 is an explanatory diagram of the connection state of the device in Fig. 1 with an air cleaner, and Fig. 4 5 is a plan view of a fuel supply control device which is an embodiment of the present invention, and FIG.
-D sectional view, Figure 6 is a line diagram comparing changes in exhaust composition of a four-cylinder internal combustion engine, Figure 7 is a line diagram comparing drivability between the device in Figure 1 and the device in Figure 4. It is a diagram. DESCRIPTION OF SYMBOLS 1... Intake passage, 2... Fuel injection valve, 3... Fuel passage, 4... Stay, end... Throttle valve, 6... Support case, 7... Bypass air path, 8...Air flow sensor, 901. Flood map B

Claims (1)

[Scope of Claims] 1. An intake passage that supplies air to the internal combustion engine, a throttle valve installed in the intake passage, a fuel injection valve installed in the intake passage upstream of the throttle valve, and a venturi. A supply fuel control device having a bypass air passage in which an upstream intake passage of the section and an intake passage of the venturi section communicate with each other through the main body wall and an air flow sensor is installed in the bypass air passage, wherein the venturi section of the intake passage and A supply fuel control device characterized in that a thin guide plate is entirely provided along the intake flow between the support case of the fuel injection valve and the lower end of the guide plate is formed to match the maximum fuel injection angle. . 2. The guide: a member whose opposite side is formed in a direction perpendicular to a stay forming a fuel passage to the fuel injection valve and divides a cross section of the intake passage into four equal parts. The supply fuel control device according to item 1.