JPS62101882A - Fuel feeding device of engine - Google Patents

Abstract

PURPOSE:To feed optimum air-fuel ratio of mixture to an engine and at the same time to prevent vapor lock occurring by adjusting the fuel pressures by means of negative ventury pressures generated corresponding to the air suction rate and by adding a constant pressure to the fuel pressure controlled with a fuel pressure adjuster. CONSTITUTION:When negative ventury pressures are weak, the opening of an escape valve 23 is great to increase fuel delivery and decrease fuel pressures in a fuel chamber 16. Accordingly the delivery out of a fuel adjuster 13 is small. As the negative ventury pressure becomes stronger, a diaphragm 19 is sucked and moved toward a negative pressure chamber 18 to decrease the opening of the escape valve 23, and to increase the fuel pressures and fuel delivery. However, a pressurizing means 28 exerts pressure via diaphragms 19 and 17 on the valve 23 to make its opening further smaller. Fuel pressurized in this way is depressurized by the amount of pressure thus added by means of a pressure adjuster 15 and blows out of a fuel nozzle 12. Generation of vapor bubbles due to the rise in the fuel temperature is also prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for supplying fuel to an engine, particularly an automobile gasoline engine.

(Prior art and its problems) Carburetors are still the mainstream for supplying fuel to automobile gasoline engines, but various fuel injection devices have been proposed because they have advantages that carburetors cannot provide. This fuel injection device injects fuel.
There are several types of control means, and among them, there is one that controls the fuel pressure using a vent valve negative pressure and continuously supplies fuel from an injection valve provided in the intake passage.

This fuel supply device has a bench lily and a throttle valve in the intake passage, and the injection valve is installed upstream of the flange valve. Further, a fuel regulator that controls fuel pressure has a fuel chamber and a negative pressure chamber that are partitioned by a diaphragm, and the fuel chamber is formed in the middle of a fuel passage that sends pressurized fuel to an injection valve. A diaphragm to which a ventilated negative pressure is introduced into the negative chamber is reciprocated, and the fuel pressure is controlled by the opening degree of the relief chamber driven by the diaphragm. According to this fuel supply system, there is a problem in that even when the throttle valve is fully open, the vent lily negative pressure led to the negative pressure chamber is weak and the fuel pressure is low. However, the essential problem of low pressure remains unsolved. Therefore, when the temperature of the fuel rises due to an increase in the ambient temperature, bubbles are easily generated, and these bubbles cause vapor lock, which greatly impedes fuel control.

(Means for Solving the Problems) An intake passage having a bench FL IJ, a fuel passage for sending pressurized fuel to the intake passage for injection, and a fuel chamber and a pen tier formed in the middle of the fuel passage. A fuel regulator in which fuel pressure is controlled in response to the negative pressure by the opening of a negative pressure chamber into which negative pressure is introduced and a relief chamber driven by a diaphragm that partitions these two chambers; The fuel pressure regulator includes a pressurizing means for applying a constant pressure to the fuel pressure controlled by the fuel regulator, and a metering unit and a pressure regulator that are sequentially provided in a fuel passage downstream of the fuel regulator.

The pressure regulator is characterized in that the fuel regulator is configured to adjust the fuel pressure to a controlled value according to the Pentieri negative pressure.

(lol example) Embodiments of the present invention will be described based on the drawings.

In FIG. 1, 1 is an intake cylinder, 2 is an intake passage extending vertically,
3.4 is a large and small double venturi.

5 is a pivot, 6 is a fuel tank, 7 is a prime mover that works during engine operation, 8.9 is a fuel pump and an air pump driven by this prime mover 7, and IO is the larger one from the fuel tank 6 via the fuel pump 8. 13 is a fuel regulator, and 14 and 15 are fuel passages on the downstream side of the fuel regulator 13. Fuel regulator 1 to 10
A measuring section and a pressure regulator are installed sequentially from the 3rd side.

The fuel regulator 13 is a fuel chamber 1 provided in the middle of the fuel passage io.
6, a negative pressure chamber 18 provided between the fuel chamber 16 and the first diaphragm 17, and an air chamber provided between the negative pressure chamber 18 and the second diaphragm 19. The diaphragm 19 has a larger effective area than the first diaphragm 17, and the arm 21 fixedly protruding from the center of the base is in contact with the center of the first diaphragm 17 so that the distance between the two diaphragms 17 and 19 is is always kept constant. Further, a return passage n is provided which opens into the fuel chamber 16 and returns the fuel to the portion of the fuel passage IO between the fuel tank 6 and the fuel pump 8, and the effective passage area is changed steplessly from zero to the maximum. A relief valve is secured to the center of the first diaphragm 17. A negative pressure passage opened at the narrowest part of the smaller pentier 4 is connected to the negative pressure chamber 18, and the air chamber is opened to the atmosphere. The second diaphragm 194 is activated.

The measuring part 14 consists of a jet 9 and a needle 9P30.

The needle 9P30 mechanically interlocks with the needle 9P30 to change the effective area of the jet 4 by linearly reciprocating motion. This metering section 14 corrects fuel control in engine idle link and low load operating ranges.

The pressure regulator 15 is provided in the middle of the fuel passage 10 and has an adjustment/arrangement 32 and a diaphragm 3 separated by a diaphragm 31.
1 and a regulating valve fixedly protruding from the center of the diaphragm 31 to steplessly change the effective area of the fuel passage 1 from zero to the maximum. It is configured to reduce the pressure by the same amount.

In this embodiment configured in this way, considering the function of the fuel regulator 13 on the premise that there is no action of the pressurizing means path, the fuel chamber 161 is pressurized to a constant pressure by the fuel pump 8. The pressure in the I negative pressure chamber 18 is P, and the negative pressure in the I negative pressure chamber 18 is P.
2. When the effective areas of the two diaphragms 17 and 19 are respectively A and B.

pt''-(upper-1)P2 holds true. That is, the negative pressure P2 of the negative pressure chamber 18 corresponding to the negative and positive of the bench lily is
It can be seen that the pressure is amplified by −(!L 1) times by 1, and is reversed to a positive pressure and adjusted by Plt-A. That is, when the vent valve negative pressure is low, the opening degree of the relief valve B is large, increasing the amount of fuel released and lowering the fuel pressure P, so that the amount of discharge from the fuel regulator 13 is small. As the negative pressure in the vent lily increases, the second diaphragm 19 suctions toward the negative pressure chamber 18, so that the opening of the relief chamber becomes smaller, and the fuel pressure P is completely increased to increase the discharge amount.

However, the pressurizing means acts on the relief valve via the second diaphragm 19 and the first diaphragm 17 to further reduce its opening. Therefore, the fuel pressure P1 is a constant pressure (P
3) is pressurized, and the fuel pressure (P+cx) actually discharged from the fuel regulator 13 becomes high. The pressurized fuel flows into the pressure regulator 15 through the metering section 14, is reduced in pressure by a pressure corresponding to P3, and is ejected from the fuel nozzle base with a fuel pressure similar to IP.

Therefore, a fuel flow rate corresponding to the vent lily negative pressure is supplied to the intake passage 2.

In addition, the pressurized air generated by the air pump 9 passes through the air passage δ and is brought to a constant pressure by an air regulator installed in the middle of the air passage δ.
After being atomized, the fuel is sent to the air nozzle I of the injector 11 through the injection passage 26, and helps atomize the fuel injected from the fuel nozzle 12.

FIG. 2 shows different embodiments of the metering section 14 and the pressure regulator 15, and shows a needle valve 30 of the metering section 14. The fuel control in the low-speed operating range is performed by linearly reciprocating the step motor I and driving the step motor I by an electronic control device (not shown). Moreover, the pressure regulator 15 is connected to the fuel passage 10.
It is composed of a larger diameter adjustment chamber 37, a valve body that opens and closes the fuel passage IO, and a spring 39 that acts between the valve bodies.
By appropriately selecting the spring 39, the pressure is reduced by the pressure applied by the pressurizing means.

9. The present invention will be described with reference to a supply device having a fuel regulator that amplifies venturi negative pressure with two diaphragms 17.19; It can also be applied to Further, the pressurizing means is not limited to a spring, and other means may also be used.

(Effects of the Invention) As described above, according to the present invention, since the fuel pressure is adjusted by the vent lily negative pressure generated in accordance with the intake air amount, it can be applied to the entire operating range of the engine with a simple configuration. It is possible to supply an air-fuel mixture with an appropriate air-fuel ratio to the engine.In particular, according to the present invention, since a constant pressure is added to the fuel pressure controlled by the fuel regulator, the rise in fuel temperature can be avoided. This prevents the generation of air bubbles and therefore eliminates the inconvenience of paper lock.Also, the pressure regulator adjusts the fuel pressure to the fuel pressure controlled according to the negative pressure in the vent lily. This not only maintains an appropriate amount of fuel supplied to the intake passage, but also allows the jet diameter of the metering section to remain the same as before, allowing adjustment in the idle link and low speed driving ranges without any problems. It is.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view thereof;
FIG. 2 is a partial vertical cross-sectional view of a different embodiment. ]... Intake path, 3.4... Bench lily, 5... Piece of paper, 8... Fuel pump, 9... Air pump. lO...Simple passage, 11...Injector, 13...Fuel regulator, 14...Measuring section, 15...Pressure regulator. 16...Fuel chamber, 17.19...Diaphragm, 1
8... Negative pressure chamber, 20... Air chamber, 23... Relief valve. 2, °〕... Pressurizing means.

Claims (1)

[Claims] An intake passage having a vent lily, a fuel passage for sending pressurized fuel to the intake passage and injecting it, and a fuel chamber formed in the middle of the fuel passage and a negative pressure in the vent lily are introduced. a fuel regulator in which the fuel pressure is controlled in response to the negative pressure in the vent lily by the opening of a relief valve driven by a negative pressure chamber and a diaphragm that partitions these two chambers;
A pressurizing means for pressurizing the fuel pressure controlled by the fuel regulator to a constant pressure, and a metering unit and a pressure regulator sequentially provided in a fuel passage downstream of the fuel regulator, and the pressure regulator 2. A fuel supply system for an engine, characterized in that the fuel regulator is configured to adjust the fuel pressure to a controlled value in accordance with the negative pressure in the vent valve.