JPH02207172A - Fuel feeding device - Google Patents

Abstract

PURPOSE:To improve the responsiveness of fuel and prevent the nonuniformity of fuel between cylinders by providing an injection valve with multiple injection holes, providing linear transporting pipes connected to suction pipes of individual cylinders, and flying and transporting fuel. CONSTITUTION:When an engine 4 is in operation, air flows in through an air cleaner 10 and is controlled by a throttle valve 2, then it is fed to the engine 4 via suction pipes 6, on the other hand fuel is fed to suction pipes 6 (6a-6d) through an injection valve 1 via transporting pipes 3 (3a-3d). Multiple injection holes 9 (9a-9d) corresponding to the number of cylinders are formed on the nozzle tip 8 of the injection valve 1, and linear transporting pipes 3 are installed for the injection holes 9. The injected fuel is flown in the transporting pipes 3 and fed to the suction pipes 6 respectively. The bypass air is fed to the transporting pipes 3 from a bypass pipe 7 opened at the upstream of the throttle valve 2, and air streams in the same direction as the flying direction of fuel are generated in the transporting pipes 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel supply system for an automobile, and particularly to a fuel supply system that is low in cost and has high engine performance.

[Conventional technology]

As described in Japanese Patent Application Laid-open No. 61-237882, the conventional device installs a bypass pipe that bypasses the main intake pipe, supplies fuel to the gathering part of the bypass pipe, and mixes it with air to form an air-fuel mixture. It is generated and distributed to each cylinder.

[Problem to be solved by the invention]

Since the above-mentioned conventional apparatus transports fuel as a mixture with air, it takes time to atomize the fuel, vaporize it, and generate the mixture. In addition, a part of the injected fuel adheres to the bypass pipe wall 7 and is transported in liquid form, which has the disadvantage that the transport time becomes longer. Furthermore, when the liquid fuel supplied to the collecting pipe is branched to each cylinder, it tends to become uneven depending on the shape of the branching part, and the air-fuel ratio between the cylinders tends to become uneven.

The object of the present invention is to eliminate the drawbacks of conventional devices, to shorten transportation time, and to equalize the air-fuel ratio between cylinders.

[Means to solve the problem]

The above object is achieved by making the number of injection holes of the injection valve the same as the number of cylinders, arranging each transport pipe in a straight line, and transporting the injected fuel by flying through the transport pipe.

[Effect]

The fuel is directly injected into the transport pipe that is paired with the injection hole using the pressure of the fuel. Furthermore, the directly injected fuel is transported by flying through transport pipes arranged in a straight line. Therefore, the distribution of fuel to each cylinder becomes uniform and the transportation time is shortened.

〔Example〕

An embodiment of the present invention is shown in FIG. 1 below.

Air flows in from the air cleaner 10, is regulated by the throttle valve 2, and is supplied to the engine 4 through the intake pipe 6.

The fuel is controlled by the rotation speed signal of the crankshaft 12 and the throttle valve opening.
The injection time is calculated in the control circuit 5 based on the opening signal of 1,
The injection valve 1 is opened, and the injector is injected from the injection holes 9 of the nozzle tip 8 into the transport pipe 3 installed facing each injection hole. The injected fuel will fly through each transport pipe.1
° It is transported near the intake valve 13. Also, bypass air is supplied to the transport pipe 3 from a bypass pipe 7 opened upstream of the throttle valve 2, causing an air flow in the transport pipe in the same direction as the direction in which the fuel flies.

FIG. 2 shows a cross-sectional view of the transport pipe. The transport pipes 3a to 3d are
Each pair is formed with the injection holes 98 to 9d of the nozzle chip 8. Further, the other end of the transport pipes 3a to 3d is a cylinder head 21.
It opens near the intake valves 20a to 20d. Injection hole 9
The fuel injected from a to 9d is transported within each of the linearly arranged transport pipes without adhering to the transport pipe walls, and is supplied near the intake valve 20 of the cylinder head 21.

Figure 3 shows the ratio of the transport pipe diameter to the injection hole diameter d and the adhesion rate Xx.
shows the relationship between Here, xl is the adhesion rate X i = adhesion amount/supply amount ... (1
). The transport tube length L is 200 nm. Note that L=
200 nn is approximately equal to the length of the transport pipes 3a and 3d. Air velocity v&=0 is the case when the flow of air in the transport pipe is stopped. Further, the fuel injection speed Vl is expressed as γ where K: constant Po: injection pressure γ: fuel density.

In FIG. 3, when ya=Q, when D/d became smaller than 10, Xl did not suddenly increase. Also,
When air flows at the same speed as vl, Xl becomes smaller. This is due to the lack of relative velocity between air and fuel. When va=3vz, Xl becomes large.

Note that when Va=2vz, it was almost the same as when va=o.

In the above method, the air speed is changed to synchronize with the fuel speed, but the same effect can be obtained by changing the fuel pressure and synchronizing it with the air speed.

FIG. 4 shows the injection valve opening signal and the intake timing of each cylinder. The injection valve opening signal is generated every 180° of crank angle, and
α1~Ha Fuel is supplied to 4 cylinders.

Therefore, the fuel required for one intake is divided into four parts and supplied to each cylinder. On the other hand, it is also possible to generate the injection valve opening signal every 360 degrees and supply the fuel required for one intake in two parts. FIG. 16 shows the timing diagram.

FIG. 5 shows another embodiment of the invention. In Figure 5,
Intake pipes 6a to 6d branch from the collector 16, and a flange 22 is attached to the cylinder head. In this example,
The fuel injection pressure is relatively low and the injection hole d is large (d=φ
/nwn). Therefore, the diameter of the transport pipe also becomes large, and D=φ10IIn. Transport pipe throttles D'14a to 14d are added to the injection hole side of the transport pipe. Further, a guide plate 23a is installed on the intake pipe 6a, and a guide plate 23d is installed on the intake pipe 6d, to guide the fuel that has flown through the transport pipe to the intake valve side in the cylinder head.
This prevents it from adhering to the wall of d.

FIG. 6 shows the inter-cylinder air-fuel ratio and the amount of non-uniformity ΔA/F when the transport pipe restriction D' and the ratio D'/D of the transport pipe are changed in the embodiment shown in FIG. Engine speed Ne=150Or
pm, when the throttle valve is fully open (WOT). Since it is WOT, there is no air supply from the bypass pipe 7. Without this air supply, D' /D = 0.4, and ΔA/
F becomes larger.

Furthermore, when air is supplied forcefully from the outside, the value remains constant without being affected by D'/D. Note that Δ
A/F=0.5 is the same as the amount of non-uniformity among the injection holes of the injection valve 1 at this time. In this way, when there is almost no inflow of air from the bypass pipe, when D'/D becomes larger than 0.4, ΔA/F becomes larger. This is because the air-fuel mixture that has blown back through the transport pipe flows unevenly when it flows into the transport pipe again.

Figure 7 shows the air flow during partial load. During partial load, since the suction negative pressure is large, it flows through the bus pass pipe 7 to each of the transport pipes 3a to 3d. This flow is independent of the stroke of the cylinder communicating with each transport pipe. Therefore, there is no air-fuel mixture blowback.

FIG. 8 shows the air flow when the suction negative pressure is small, such as in WOT. Almost no air flows into the bypass pipe 7. Now, if the Nα3 cylinders communicating with the transport pipe 3c are in the intake stroke, the transport pipes 3a and 3b.

In 3d, air (air mixture) flows backwards from the cylinder side, and the transport pipe 3
flows into c. Next, when the Nα4 cylinder enters the intake stroke, it flows into the transport pipe 3d. However, in the case of transport pipe 3c (3b), it is supplied from both sides (3b, 3d), whereas 3d (
3a) is supplied from one side, resulting in non-uniformity. Therefore, when the transport pipe throttle D' is added, the non-uniformity is improved due to its throttle effect. However, since the maximum amount of non-uniformity is close to 2.0, even if φD' is increased, ΔA/F will not exceed 2.

FIG. 9 is a sectional view of the nozzle tip 8 of the injection valve 1. When the valve body 17 separates from the valve seat 18, fuel flows into the fuel passage 19 and is injected from the injection hole 9.

FIG. 10 is a sectional view taken along line AA' in FIG. Injection hole 98
~9d are radially perforated. In addition, the injection holes 98 to 9
d is bored in a direction perpendicular to the fuel passage 19.

FIG. 11 shows another embodiment of the injection valve 1. Fuel passage 1
9 and the injection holes 9a to 9d are bored on the same plane. In this case, a large amount of dynamic pressure from the fuel passage 19 is applied to the injection holes 9b and 9c. Therefore, the injection holes 9b and 9c need to be smaller than the injection holes 9a and 9d.

FIG. 12 shows another embodiment of the transport pipe. The gap between the nozzle tube 8 and the transport pipes 3a to 3d is eliminated, and each transport pipe is made independent. Therefore, since there is no exchange of air-fuel mixture between the transport pipes, ΔA/F is not affected by the suction negative pressure.

FIG. 13 shows an example of application of a V type 6 cylinder. Inlet pipes 6a to 6f are branched from the collector 16. 3 from injection valve 1b
Since the fuel is injected in the direction, the transport pipes 3a, 3c, 3e
There are three.

FIG. 14 is a central sectional view of FIG. 13. injection valve 1a,
There are lb and 2 injectors, each supplying fuel to 3 cylinders.

FIG. 15 is a view taken along arrow P in FIG. The guide plate 23d has a semicircular shape.

FIG. 17 is a cross section taken along line AA' in FIG. By providing the passage 25 to allow air to flow, it is possible to prevent the fuel 3a and 3d in FIG. 7 from flowing into 3b and 3c due to the air flow. Also, as shown in Figure 18, connect the air inlet to the nozzle tip 8.
By opening a hole at the tip of each transport pipe 3, the air flow is
a, 3b.

3c and 3d can be made the same, eliminating uneven fuel distribution.

〔Effect of the invention〕

According to the present invention, since the injection hole and the transport pipe are provided for each cylinder, fuel non-uniformity between the cylinders is reduced.

Furthermore, since the fuel is transported while flying through the transport pipe, the response of the fuel becomes faster.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the present invention, Fig. 2 is a sectional view of a transport pipe, Fig. 3 is a diagram showing experimental values showing the relationship between D/d and Xl, and Fig. 4 is a diagram showing experimental values showing the relationship between D/d and Xl.
The figure is an explanatory diagram showing the relationship between the injection valve opening signal and the intake stroke of each cylinder, Figure 5 is a sectional view of the transport pipe of another embodiment, and Figure 6 is D
' A diagram showing experimental values showing the relationship between /D and ΔA, /F, Figure 7 is an explanatory diagram showing the air flow at partial load, Figure 8 is an explanatory diagram showing the air-fuel mixture flow at WOT, Figures 9 and 11
The figure is a cross-sectional view of the nozzle tip of the injection valve, Figure 10 is a view showing the AA' section of Figure 9, Figure 12 is a partial cross-sectional view of the transport pipe, and Figure 13 is a front view of another embodiment. 14 is a central sectional view of FIG. 13, FIG. 15 is a view taken along arrow P in FIG. 5, FIG. 16 is a timing diagram, and FIGS. 17 and 18 are A-A in FIG. 7.
'This is a cross-sectional view. 1... Injection valve, 2... Throttle valve, 3... Transport pipe, 4
...Engine, 5...Control circuit, 6...Intake pipe,
7... Bypass pipe, 8... Nozzle tip, 9...
Injection hole, 13... Intake valve, 14... Transport pipe throttle, 1
5... Bypass pipe restriction. Figure 3 () / Pressure height 4 map () / D Tame 8 Figure 2 Kuchi height 10 section Right horse map Lai 15 Figure l1lL 3Q-

Claims (1)

[Scope of Claims] 1. An injection valve having a plurality of injection holes and a transport pipe paired with the injection holes, and the transport pipe is configured to transport fuel by flying it through the transport pipe. A fuel supply device characterized by being arranged linearly. 2. Ratio D/ of the diameter d of the injection hole and the diameter D of the transport pipe
2. The fuel supply device according to claim 1, wherein d is 10 or more. 3. A throttle is attached to the injection hole side of the transport pipe, and the diameter of the throttle is D'.
2. The fuel supply device according to claim 1, wherein the ratio D'/D of the diameter D of the transport pipe and the diameter D of the transport pipe is 0.4 or less.