JPS58144663A - Fuel supplying apparatus - Google Patents

Abstract

PURPOSE:To prevent attaching of fuel to the wall surface of an intake pipe, by forming a substantially horizontal, straight pipe section on the upstream side of an intake port, connecting a bend section to the upstream side of the straight pipe section, and attaching a fuel injection nozzle to the outside of said bend section in the manner that the direction of fuel injection is aligned with the direction of air flow in the intake pipe. CONSTITUTION:In an engine 1 in which air supplied to a concentrated tank 7 from a duct 9 having a throttle valve 8 and an air-flow meter 10 is introduced into a plurality of cylinders via respective branch pipes 5, each of the branch pipes 5 consists of a straight pipe section 15 extended substantially horizontally on the upstream side of an intake port 37 and a bend section 14 connected to the upstream side of the straight pipe section 15. The bending angle of the bend section 14 is preferably greater than 90 deg., and a fuel injection nozzle 6 is attached to the outside of the bend section 14 such that the center of the injected fuel comes to the axis a-a' of the straight pipe portion 15 and the top of the injection nozzle 6 is located slightly above the axis a-a' of the straight pipe section 15.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel supply system, and particularly to a fuel supply system suitable for use in an electric spark ignition engine.

Conventional fuel supply systems include carburetors, single point fuel injection systems, and intake port fuel injection systems that supply fuel from near the intake valves of each cylinder. The disadvantage of the previous method is that it takes a long time for the fuel to reach the cylinder via the intake pipe.

The latter has the disadvantage that the distance to be delivered to the cylinder is short, and the fuel enters the first cylinder where it does not evaporate. It is well known that these drawbacks seriously degrade engine performance. In order to prevent the former drawback, there is a method of atomizing the fuel with a rotary tip, as in U.S. Pat. No. 4,283,358, and a method of promoting atomization with a throttle valve deflector and a mixing tube, as in U.S. Pat. No. 4,281,632. , U.S. Patent 428046
No. 3 discloses a method of colliding fuel with a fuel dispersion member to atomize the fuel, and U.S. Pat. No. 4,285,320 discloses a method of promoting fuel atomization using gold steel. I haven't reached the point where it's resolved.

In order to prevent this drawback, there is a method of atomizing fuel in an intermittent injection valve using compressed air as in U.S. Pat. No. 4,280,661, and a method of atomizing fuel with a hemispherical opening valve as in U.S. Pat. No. 4,281,797. have been disclosed, but these have not completely solved the above drawbacks.

In addition, as in Japanese Patent Application Laid-open No. 55-104519, one injection of fuel is actively applied to the intake pipe or the inner wall surface of the cylinder,
A method has been proposed that uses wall evaporation to prevent the drawbacks of multi-point injection systems, but if it adheres to the intake pipe wall, the supply of fuel to the cylinder will be delayed. However, it requires a direct injection system, which has the disadvantage of increasing costs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel supply iron lid that can prevent the above-mentioned drawbacks by supplying fuel at a location away from the intake valve and into a branch pipe downstream of the collecting section.

The present invention has experimentally confirmed that in an intake boat fuel injection system, the fuel injected from the injection nozzle directly collides with the intake valve and coarse particles enter the cylinder, and in order to prevent this, the injection nozzle is It is placed sufficiently upstream of the intake cylinder. In the conventional arrangement of the intake manifold and injection nozzles, simply moving the injection nozzles away from the intake valves will inevitably cause fuel to adhere to the walls of the intake manifold, resulting in a delay in fuel transport, as in the case of a carburetor. was found to increase. In order to avoid this, a bed part is provided in a part of the branch pipe of the intake manifold, and an injection nozzle is arranged so that fuel is injected toward the center downstream of the vent part.

A configuration in which the injection nozzle is moved away from the intake valve is disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 55-104519, but in this case, the direction of the injection is changed so that the injected fuel is actively deposited on the wall surface of the intake pipe. It is deviated from the flow direction of the intake pipe.

In the present invention, a bead part is provided downstream of the collector of the intake manifold, and a straight pipe part is provided downstream of the bend part, so that the direction of injection and the flow direction of the intake pipe are made to match. The objective 1 function and effect are different from the above-mentioned known examples in that fuel is prevented from adhering to the wall surface of the intake pipe.

In other words, an almost horizontal straight pipe section is provided upstream of the intake boat, a bend section is provided upstream of the straight pipe section, and an injection nozzle is provided outside the bend section. The flow direction of the tube and the injection direction of the injection nozzle are made to match.

The present invention is particularly effective when the passage of the intake boat section is curved in order to strengthen the swirl. In such a case, if fuel adheres to the intake valve or the trachea as in the conventional known example, the fuel entering the trachea will be skewed and the engine performance will be significantly reduced.

In this way, an intake manifold in which a bed section is provided upstream of a straight pipe section is conventionally used in combination with an intake boat fuel injection device. Therefore, by using a known intake manifold and attaching a conventionally known injection nozzle to the bend portion, the configuration of the present invention can be obtained. Therefore, there is an advantage that the objective can be achieved without significantly improving conventional parts. Naturally, an injection nozzle in which fuel flows out from the nozzle is inappropriate is unsuitable, and a sufficient effect cannot be obtained. It is desirable that the fuel particles have a diameter of 100 microns or less. The slip distance of the particles, that is, the distance that the particles ejected from the nozzle until they stop due to air resistance, is proportional to the square of the particle diameter and the initial velocity, and is 20 μm in diameter.

For initial velocity 600 m/s, s o c m@H
become.

If the initial velocity is l Q m / 8, then 1.3cm8K
become. If the particle size is 100μ, it will be about 33cm. The straight pipe part of the intake manifold also has a length of this length, and under these conditions, the fuel ejected from the nozzle goes straight and hits the intake valve or a wall near the intake valve. Never. Therefore, in the present invention, it is essential to use an injection nozzle that satisfies the above conditions. According to Laughing Fin, conventionally known spiral injection nozzles (spiraling the fuel or auxiliary air to prevent particles from going straight), vibrating valve type nozzles (flowing fuel in a conical film shape and preventing particles from going straight) At the same time, it was found that the above-mentioned properties were satisfied by the ultrasonic vibrating nozzle (which causes the membrane to vibrate to speed up the splitting), and the ultrasonic vibrating nozzle (which splits the water flow or jet stream by vibration). . Furthermore, from the standpoint of fuel fR formation, a nozzle that jets fuel continuously is more advantageous than one that jets fuel intermittently from a nozzle. A product that ejects continuously is the product name K-Jetro from West German Bosch.
A vibrating valve type nozzle is used in this type of nozzle. However, this nozzle is mounted close to the intake valve and does not completely overcome the drawbacks of the prior art. That is, according to experiments, it has been found that, as shown in FIG. 13, at the beginning of the intake stroke, at the beginning of the piston's descent, the air that closes the intake valve directly collides with the piston head. Therefore, the fuel near the intake valve also hits the piston head together with the air and is redeposited. Therefore, in the case of K-JetrO, even if the fuel is atomized by the vibrating valve type nozzle, the spray is located near the intake valve, and it is difficult to prevent the fuel from re-adhering to the piston head. On the other hand, in Figure 14, where the piston is lowered (crank angle 60 [or later)], the air is turbulent before reaching the piston head surface, and the fuel entering the cylinder at this time is prevented from re-adhering to the piston head surface. It turned out that it was. This phenomenon is new knowledge obtained through many years of research into internal combustion engines. therefore,
In the present invention, based on this new knowledge, the piston is sufficiently lowered by not allowing fuel to be present near the intake valve at the beginning of the intake stroke, in other words, by providing the fuel nozzle at a distance from the intake valve. After that, the fuel passes through the intake valve.

In this regard, although a continuous ejection vibration valve such as K-Jetro is used, the operation and effect are different. In K-Jetro, fuel is present near the intake valve at the beginning of the intake stroke, so fuel is sucked in in the state shown in FIG. Since fuel is present at a position away from the valve, fuel is sucked in in the state shown in FIG. 14. In the case shown in FIG. 13, when fuel is sucked in, the fuel re-adheres to the piston head, and the air-fuel mixture below the cylinder becomes richer. This indicates that the air-fuel mixture near the spark plug is becoming leaner, resulting in poorer combustion. On the other hand, when fuel is sucked in as shown in FIG. 14, the air-fuel mixture below the cylinder is prevented from becoming diluted near the spark plug.

Therefore, compared to the conventional known example, there is an effect that the formation of the air-fuel mixture can be greatly improved by simply changing the position of the injection nozzle slightly.

This is done by installing a straight pipe section upstream of the intake valve, and installing an injection nozzle with a slip distance shorter than the length of the straight pipe section upstream of the straight section so that the injection direction is the same as that of the straight pipe section. This can be achieved by adding *p.

In FIG. 1, an intake manifold 11 is arranged upstream of an intake valve 2 of an engine 1. As shown in FIG. Intake manifold 11
There is a branch pipe 5, and conventionally, fuel was supplied from the injection nozzle 4. In this configuration, even if the injection nozzle 4t is provided at a position away from the cover 3, collision of the fuel with the lower surface of the branch pipe 5 cannot be avoided. The diameter of branch pipe 5 is 39mm
Therefore, the fuel ejection speed of nozzle 4 is set to 30 m
/ 8 then 1. l m s gradually reaches the bottom surface. Even if the nozzle is tilted 45 degrees, it will slow down to the bottom surface in about 1.4 ms, and there is no room for evaporation. In the present invention, fuel is supplied from the injection nozzle 6. A collection tank 7 is provided upstream of the branch pipe 5 to prevent interference between the intake air of each cylinder.

As shown in FIG.
．． Duct 9. An air flow meter 10 is provided.

One injection nozzle 6 is provided in each branch t5, and upstream of the injection nozzle 6, a metering section 1 is connected via a fuel nozzle 12.
3 are connected. FIG. 3 shows the intake manifold 11 viewed from below. a-a', bb in Fig. 3
', c-c'.

A straight pipe portion exists in the section dd'. The injection nozzle 6 is attached so that the center of the spray is on this assembly.

The length of the above linear section is 100 mm. FIG. 4 shows the intake manifold 11 viewed from the side, and the bending angle θ of the bend portion 14 is 90 degrees or more. In rare cases, 9
Temperatures below 0 degrees are also used. The injection nozzle 6 is attached to the direct point a-a' so that the center of the spray is located.

As shown in Fig. 4, the position iin of the tip of the nozzle 6 is
It is provided slightly above Q from the a-a' line. This is it, 9
, a-zn increases. This is advantageous in terms of the origin of the spray. a % n distance #I & is 150m
Since the distance is about m, all the fuel injected ti evaporates until the point a is reached, and it is possible to prevent the fuel from colliding with the intake valve 2. Also, the air in the branch pipe 5 is -Io due to the heat of vaporization of the fuel.
ta' decreases. This improves the charging efficiency of the engine. Fuel is continuously injected from the nozzle 6. In the case of a four-cylinder engine, the air in the branch pipe 5 moves once every two revolutions, only during the intake stroke. Other than that, the air is almost stationary, and the jet from the nozzle 6 is bent by the total air flow and does not come into contact with the wall of the branch pipe 5. The spray moves to the left during the intake stroke. Initially, air near the intake valve enters the cylinder.
Next, as the fuel spray is sucked in, the fuel 1IJjsl
is placed at the top of the cylinder, near the spark plug, to promote combustion. As the fuel nozzle 6, the fifth
The hemispherical outward opening fP15 shown in the figure can be used. It is well known that the action of the springs 16 generates vibrations of about 2 KHz, and this vibration promotes atomization of the fuel. In addition, a passage 17 through which cooling water or exhaust gas passes can be provided in a part of the branch pipe 5 to heat the part of the branch pipe 5. It is also possible to provide a stepped portion as shown in FIG. 5 to tear off the fuel liquid film. With such a simple configuration, fuel can be supplied to the cylinders Km according to the movement of air during the intake stroke, without causing fuel to remain in the branch pipe 5. 9, stepped part 1
By providing 8, the fluid resistance during engine blowback increases, the blowback amount is reduced, and filling efficiency can be increased. The measuring section 13 is constructed as shown in FIG. The fuel in the fuel tank 19 is 0.3-5.0k by the pump 20.
f/cm", passes through the filter 21 and damper 22, and is supplied to the metering valve 23. The metering valve 23 moves up and down in the cylinder 24. As it moves upward, the opening area of the orifice 25 increases. The amount of injection from the nozzle 6 increases.

The pressure across the orifice 25 is maintained constant by a differential pressure regulator. Further, the pressure of the metering valve 23 is maintained constant by a pressure regulator 27. In the case of 4 cylinders, orifice 25, differential pressure regulator 26. Although four nozzles 6 are provided, they are omitted in FIG. Measuring valve 23
is pushed by the rod 28. Pulse motor 2
When the rotor 3o of 9 rotates, the rod 28 moves up and down.

An air valve 31 is connected to the other end of the rod 28 .

The upstream port '332 of the air valve 31 is connected to the upstream side of the air flow meter 10 via the hot wire airflow meter 34, and the downstream port 33 is
It is connected to the venturi section of the air flow meter 10. A total of 34 wind signals are sent to the controller 35, and the pulse motor 29 is rotated so that the signal from the airflow meter 34 becomes constant. Since these operations are well known, their explanation will be omitted. As the air cap through the air 70-meter 1o increases, the air valve 31 operates to close, the rod 28 moves upward, and the opening area of the orifice 25 increases. air valve 3
1 and the orifice 25, the amount of fuel corresponding to the amount of air can be obtained. Air fuel ratio is air volume meter 34
It can be freely controlled by changing the set value of . In FIG. 2, a supercharging co/greaser 36 is provided upstream of the throttle valve 8.

In this case, since the pressure in the intake manifold 11 is higher than atmospheric pressure, it is necessary to increase the pressure in the injection nozzle 6, or in the embodiment shown in FIG. 6, the fuel flow rate does not change depending on the pressure. do not have. Diameter t of injection nozzle 6 1.5φm
m, and the diameter of the valve 15 is 3 mm, the slip distance of the injection nozzle is about 150 mm, and the fuel spray does not enter the intake valve side at two or more points in FIG. 4. The diameter of the fuel particles of this fuel spray is 100 μm, and the diameter is 80 m5.
Evaporates in a certain amount of time. At an engine/engine rotation speed of 60 rpm, the period of one rotation is i, 6 J) ms, and air intake is performed once every z rotation.

The fuel that was injected at the beginning was blown into the cylinder after 150m5, so it evaporated in the process. In Figure 1,
From the end face of the flange 37 of the intake manifold, the intake valve 37
There is a distance of about 100 mm between the two and the distance is filled with air. In FIG. 1, the collection tank 7 is attached at the top, but the bend of the section 14 is opposite to that in FIG. In this way, by providing a bend part,
The ejection direction of the nozzle 6 can be matched with the flow direction of the straight f section without inserting the entire nozzle 6 into the branch pipe 5 of the intake manifold 11. Fuel cut during deceleration is performed by pulling down the rod 28 and closing the metering valve 23, as shown in FIG.

If the fuel cut continues, the branch pipe 5 of the intake manifold 11 will contain only air. In this state, when the engine speed drops to the idle state and the fuel cut is stopped, the cylinder immediately after the return is supplied with the normal 1
Only 1/4 of the amount of fuel is supplied, and the engine is likely to stall, that is, stop. This has an idle speed of 50 Orr.
By restoring the fuel at a rotation speed higher than pm,
It can be avoided.

FIG. 7 shows the engine of the division method. In FIG. 7, the three cylinders are connected via a branch pipe 45.
It is connected to a collection tank 40.

The other three cylinders are connected to the collecting tank 41 via branch pipes 46. The collecting tank 41 is connected to an exhaust pipe 47 through a switching valve 42. It is connected to one of the collection tanks 40.

When the load on the engine 1 is small, the switching valve 42 is placed in position A to introduce exhaust gas into the branch pipe 46 and stop supplying fuel from the injection nozzle 43. That is, combustion in the three cylinders stops. On the other hand, when the load is high, the switching valve 42 is
position, and while introducing air into the branch pipe 46, fuel is also supplied from the injection nozzle 43. In this way, combustion occurs in all cylinders. In this case, the configurations of the branch pipe 45, the branch pipe 46, and the injection nozzle 43.44 are as shown in FIGS.
With the configuration shown in the figure, similar effects can be achieved even in a split-type engine. Also, in order to cant the fuel to the injection nozzle 43, the sixth
As shown in the figure, a solenoid valve 45 is provided in the middle of the fuel pipe 12'. FIG. 8 shows the structure of the intake manifold of a six-cylinder type engine. In this case, the collecting tank 7 is mounted in the center of the engine 1, and the intake air is distributed by the branch IIf5. 8th
In the figure, by attaching the nozzle 6 at a position remote from the intake valve 2, it is possible to achieve the same effect 75 as with a size engine. In the intake manifold having such a configuration, the height of the collection tank 7 tends to increase.

To prevent this, in the case of a 4-cylinder engine,
The configuration of the intake manifold 11 shown in the figure can be adopted. Figure 9 is a view from above, and Figure 10 is a view from the side. In this case as well, similar effects can be achieved by attaching the nozzle 6 at the illustrated position. Even in the case of a V6 engine, by using the intake manifold 11 configured as shown in Fig. 11, the collecting tank 7 can be placed low, and by installing the nozzle 6 in the position shown, the same effect can be achieved. can be raised.

FIG. 12 shows an example of an ultrasonic temporary vibration type injection nozzle 61 as another example of the injection nozzle 6.

An electrostrictive element 63 is attached to one end of the nozzle 61, and a voltage generated by a circuit 64 is applied to both ends of the electrostrictive element 63. This causes the nozzle 61 to vibrate at a threshold resonance frequency of 1 to 100 kHz. Fuel enters the nozzle 61 from the vibro 5 and is ejected from the nozzle hole 62. At this time, the jet stream is atomized by the above-mentioned vibration, and becomes a spray with a particle size of 100 μm or less.

In FIG. 12, the area of the nozzle hole 62 is a, and the area of the sphere valve 6 is
If the area of 6 is b, then the fuel flow rate q of the nozzle hole 62 is q=ayl below (1). On the other hand, the flow rate q, passing through the spill valve 66 is q,=bV/jp (2). Now, if q + qt = Q-foot, (a
+b) V7j=Q... (3) Tona9
, holds true. If the amount of air is G, then it becomes 0. Here, if the fuel flow rate of the pump 20 is set to one foot by the metering valve 67, that is, Q is set to one foot, and the opening area of the spill valve 66 is made inversely proportional to G, R becomes as shown in equation (6). constant, that is, the air-fuel ratio becomes constant. The rod 28 in FIG. 6 is also configured so that the air valve 31 closes when the amount of air increases, so the spill valve 66 can be moved using this configuration.

According to the present invention, it is possible to prevent fuel from adhering within the cylinder without increasing the delay in fuel transportation, so that engine performance can be significantly improved.

[Brief explanation of the drawing]

Figures 1 to 12 show the structure of the present invention,
3 and 14 are explanatory diagrams of airflow. l...Engine, 11...Maki Manifold, 6...
・Injection (Lino Tea l Country v-/3 Country No. 74

Claims (1)

[Scope of Claims] 1. Upstream of the air valve, there is a ml passage through which the fuel jet ejected from the injection nozzle can go straight, and upstream of the first passage there is a second passage having a bending path for the intake air. . A fuel supply device comprising: an injection nozzle installed so that spray is ejected from the outside of the bend in the direction of air flow in the first passage. 2. The fuel supply device according to item 1 d, characterized in that the fuel supply device is equipped with an injection nozzle in which the slip distance of the spray is smaller than the length of the first passage. 3. The fuel supply device according to item 1, characterized in that the fuel supply device is equipped with means for measuring the amount of fuel ejected in a delayed manner. 4. No. I, characterized in that the upstream sides of the plurality of second passages or more are connected to a collecting tank, and a throttle valve is provided upstream of the collecting tank.
Fuel supply device described in JA. 5. The fuel supply device according to item 1, characterized in that a part of the first passage is provided with a heating section.