JPH02241977A - Fuel supply device for engine - Google Patents

Abstract

PURPOSE:To promote fuel atomizing and prevent atomization adhesion to a combustion chamber wall surface so as to reduce HC by making atomization jetted from a fuel injection valve which carries out direct fuel injection to the inside of a chamber have a collision with each other near a fuel injection port. CONSTITUTION:When fuel is fed to a fuel pool 31 by the command of a control unit to raise pressure, the fuel flows in the clearances generated at angular shaft portions 38b on the backs of the upstream passage hole 37b and the core valve 38 of a valve seat 37a in the body 37 of an outer opening valve 35 respectively. Fuel pressure pushes a valve body 38a against a coil spring 45, and the fuel enters an assist air turning portion 40b from a valve opening generated at the section to the valve seat 37a to mix with assist air of turning flow sufficiently. The mixture is atomized at the clearance between an air valve portion 39, and a guide portion 41 and an air valve seat portion 42 and is jetted into a hollow conical shape as indicated by dashed lines. Then it has a collision with each other at point C near a fuel injection port 8a, and after collision, it spreads out in a fan shape to promote atomization further and simultaneously decrease atomizing speed, then no atomization adhesion to a housing 2a takes place.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel supply device for an engine that injects fuel directly into the combustion chamber of the engine.

(Prior Art) Conventionally, as a fuel supply device for this type of engine, for example, Japanese Patent Application Laid-Open No. 63-147924 and Japanese Patent Application Laid-Open No. 63-16
As described in Japanese Patent No. 2938, there is a known rotary engine in which fuel is directly injected into the working chamber so that a rich air-fuel mixture is unevenly distributed on the leading side. Each of the above devices injects fuel into the combustion chamber of the engine, that is, the working chamber of the low-pressure engine, by having a fuel injection valve facing the injection port formed in one side housing. Since the shape of the injected fuel is a round hole or an annular ring, there is a problem in that the injected fuel is not sufficiently diffused, resulting in insufficient atomization. Further, since the injected fuel has a high straightness and penetrating power, it tends to adhere to the wall surface of the other side housing that faces the injected fuel, which causes a problem of poor combustibility and an increase in HC in the exhaust gas.

The present invention was made in view of the above-mentioned problems, and its purpose is to promote atomization of fuel, prevent the spray from adhering to the wall surface of the combustion chamber, and improve H
An object of the present invention is to provide a fuel supply device for an engine that reduces C.

(Means for Solving the Problems) As shown in the embodiment drawings, the present invention injects fuel directly into the room from a fuel injection valve (8) facing the combustion chamber (6).
This is a fuel supply system for an engine in which sprays ejected from a fuel injection valve (8) collide with each other near a fuel injection port (8a).

(Function) Since the sprays collide with each other near the fuel injection port (8a) of the fuel injection valve (8), atomization within the combustion chamber (6) is promoted.
Furthermore, since the penetrating force of the spray is weakened, it is prevented from adhering to the wall surface of the opposing combustion chamber (6).

(Example) Hereinafter, the first example when the present invention is applied to a low-recruiting engine will be described.
An embodiment will be described based on FIGS. 1 to 5.

A rotor housing (1) with a two-section peritrochoid-shaped inner circumferential surface and a side housing (2) that covers both sides of the rotor housing (2).
2a) It has a casing (3) consisting of the following, and a rotor (4) whose basic shape is a three-lobed inner envelope. Rotor (4
) is supported by the eccentric part of the eccentric shaft (5), and rotates and revolves due to the engagement between the rotor gear and the fixed gear (none of which are shown). Each vertex of the rotor (4) is always in contact with the inner peripheral surface of the rotor housing (1) and slides while drawing the same trochoidal locus. Three working chambers (6) are formed between the casing (3) and the rotor (4), and each stroke of suction, compression, expansion, and exhaust is performed with a phase difference. The intake boat (7) opens into the working chamber surface of the side housing (2). In addition, the side housing (2
), the first fuel injector (8) is connected to the spark plug (9), (
The fuel injection port (8a) is arranged so as to face the injection boat (I+) opened near Iω. The intake boat (the second fuel injector θ is connected to the intake passage θ)
3), throttle valve (14) and air flow meter 05
) are arranged in sequence.

1st. Fuel is supplied to the second fuel injection valve (8), Q3) from a fuel tank 06) by a fuel pump (17) through a fuel supply path 08).

In addition, the first fuel injection valve (8) is equipped with an air flow meter 09.
An assist air supply path QΦ with an air pump 09) is led from the intake passage 02) downstream of the air pump 09), and an assist air exhaust path (2I) is connected to the assist air exhaust path QΦ from the first fuel injection pump (8) on the upstream side of the air pump 09). Air supply path +2 [Connected to D. The control unit (22) receives information from the throttle sensor (23), engine speed sensor (24), and engine water temperature sensor (25), respectively, and controls the first fuel injection valve (8) and the second fuel injection valve O■. It controls the timing and amount of fuel injection, and also controls the assist air control valves (26) and (27) to control the timing and amount of assist air supplied to the first fuel injection valve (8). (28) is an exhaust port.

Next, the first. The operation of the second fuel injection valve (8), O
Only the fuel injection valve (8) injects fuel together with assist air into the leading side of the compression stroke. As a result, the rich air-fuel mixture can be mainly stratified near the spark plug (9) and Qω to facilitate ignition, while the other parts are located near the intake passage 021.
This results in a lean air-fuel mixture mainly consisting of air from the engine, which improves fuel efficiency in the low-load rotation range (A) such as during idling. In addition, in the high-load, high-speed region (B), the second fuel injection valve 03) is mainly used, and the first fuel injection valve (8) is used auxiliary on the leading side of the combustion chamber to improve ignition performance. Reliable ignition can be achieved by stratifying the fuel around the plug (9), GO).

The configuration of the first fuel injection valve (8) is as shown in FIG. A cylindrical body (30) is arranged below it to form a fuel storage chamber (31) inside, and an assist air passage supply side (32a) and an assist air passage exhaust side (32a) are arranged on the outside. 32b), the upper ends of which form an assist air inlet (33) and an assist air outlet (34), respectively.
It communicates with.

Further, the lower end of the fuel reservoir chamber (31) communicates with an outer valve (35) provided at the lower end of the first fuel injection valve (8). On the other hand, the assist air passage supply/exhaust side (32a), (
Both the lower ends of the cylindrical body (30) and the outer valve (32b)
The outer wall (36) of the assist air passage that communicates with the injection side (32c) formed on the outside of the assist air passage (35) and surrounds the outside of this passage has a outer valve (35).
The opening corresponding to the front side of the fuel injection port (8a) is opened. In other words, the front of the outer valve (35) is the working chamber (6).
) are arranged as desired.

The outer valve (35) is shown enlarged in Figure 4.
A heart valve (38) is fitted into the main body (37), and an air valve portion (39) is formed at the tip. Also, the body itself (37
), and the attachment (40) has a guide part (41) inclined at a predetermined angle along the outer periphery of the air valve part (39) and an air valve seat part (42) in the front part. ) and a fifth section at the rear.
As shown in the figure, there are four assist air introduction sections (40a
) and an assist air swirling section (40b).

In addition, there is a tapered valve body (38) in the center of the heart valve (38).
) and the valve seat (37a) of the body body (37) are connected to the heart valve (3
8) The retainer (44) attached to the rear end is brought into close contact with the elasticity of the coil spring (45) that biases it in the axial direction, thereby blocking the fuel passage.

In this way, a large amount of assist air is supplied by the air pump 09) from the intake passage θ through the assist air supply path +2[D] to the assist air control valves (26) and (27) according to commands from the control unit (22). When open, the assist air enters the assist air passage supply side (32a) from the assist air inlet (33), descends in the direction of the solid arrow, and then passes through the assist air passage injection side (32c) to the outer valve (32a).
5) flows into the assist air introduction section (40a). The assist air then enters the assist air swirling section (40b) and generates a swirling airflow.

On the other hand, when fuel is fed into the fuel reservoir chamber (31) and the pressure increases according to a command from the control unit (22), the fuel is transferred to the upstream side of the valve seat (37a) of the body main body (37) of the outer valve (35). The liquid flows through the gap formed in the through hole (37b) made in the hole (37b) and the square shaft part (38b) formed in the rear part of the heart valve (38) as shown by the arrows. The pressure of these fuels presses the valve body (38a) against the elasticity of the coil spring (45), and the fuel flows from the opening of the valve created between the valve seat (37a) and the assist air swirling part ( 40b)
The air enters the air and mixes thoroughly with the swirling assist air. This air-fuel mixture is sprayed into the gap between the air valve part (39), the guide part (41) and the air valve seat part (42), and is vigorously ejected into a hollow conical shape as shown by the dashed line. collide with each other at the zero point near the fuel injection port (8a). After the spray collides, it spreads out and atomization is further promoted, and at the same time, the speed of the spray further decreases, so that the spray does not collide and adhere to the inner wall of the opposing side housing (2a). .

Next, a second embodiment of the present invention will be described based on FIGS. 6 and 7. FIG. 6 is a diagram corresponding to the external valve (35) in FIG. 4, and the external valve (46) includes a cardiac valve (47) and an attachment (48).
) is different from the outer valve (35) only in the shape. Therefore, other components of the outer valve (46) are designated by the same reference numerals as those of the outer valve (35).

The umbrella-shaped part (47a) and neck part (47) of the front end of the heart valve (47)
As can be seen from FIG. 7, which is a front view of the umbrella-shaped part (47a), b) is provided with four through holes (49) that are opened from the neck part (47b) to the umbrella-shaped part (47a). It is being

These through holes (49) are similar to the outer valve (45) shown in FIG. is tilted at a predetermined angle in the same direction as the turning direction of the Further, the opening of the attachment (48) forms an inner circumferential edge (51) with a predetermined gap and inclined at a predetermined angle at the outer circumferential edge (50) of the umbrella-shaped portion (47a).

Fuel flows from the fuel reservoir chamber (31) into the outer valve (46) in the direction of the dotted arrow as in the first embodiment, presses the heart valve (47) in the opening direction, and the fuel flows into the assist air. The air enters the swirling part (40b) and mixes with the assist air. In this air-fuel mixture, the spray ejected from the gap between the outer circumferential edge (50) and the inner circumferential edge (51) and the spray ejected from each through hole (49) collide at points C5 and 02 near the fuel injection port (8a). However, after that, the spray is dispersed and atomization is further promoted. At the same time, the speed of the spray is slowed down to prevent the spray from colliding with and adhering to the opposing side housing (2a).

Furthermore, in this embodiment, the umbrella-shaped portion (4) of the heart valve (47)
Since four through holes (49) are provided in 7a), when the valve is closed, the umbrella-shaped part (47a) is closed (48
) Even if the opening of the hole (49
) can flow out and hit the heart valve (47) 4
This has the effect of stabilizing valve behavior and reducing A/F variations by reducing the influence of the dynamic pressure of °.

The present invention has been described above in the first aspect. Although the second embodiment has been described with reference to a case where it is applied to a reciprocating engine, the present invention can also be applied to a reciprocating engine.

(Effects of the Invention) According to the present invention, when injecting fuel directly into the combustion chamber of an engine from a fuel injection valve, the sprays from the fuel injection valve are made to collide with each other near the fuel injection port. This promotes atomization of the fuel and prevents the spray from adhering to the opposing wall surfaces in the combustion chamber, improving combustibility and reducing HC in the exhaust gas.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the overall configuration of a fuel supply system for a rotary piston engine as an application example of the present invention, and Fig. 2 shows a first fuel injection valve that injects fuel into the combustion chamber, and a first fuel injection valve that injects fuel into the intake passage. A diagram showing a usage area with a second fuel injection valve,
3 to 5 are for explaining the first embodiment of the present invention, and FIG. 3 is a partial vertical cross-sectional view of the first fuel injection valve, FIG. 4 is a vertical cross-sectional view of the outer valve, and FIG. The figure is a sectional view taken along the line V-V in FIG. 4. 6 and 7 illustrate a second embodiment of the present invention, in which FIG. 6 is a longitudinal sectional view of the external valve, and FIG. 7 is a front view of the umbrella-shaped portion of the heart valve. 6... Combustion chamber 8... Fuel injection valve 8a... Fuel injection port 35.46... Outer valve C, C,, C,...
Spray impact point patent Applicant Mazda Motor Corporation Fig. 1 Fig. 2 Q Engine rotation number (RPN) MAX Fig. A Fig.

Claims (1)

[Claims] In an engine fuel supply system that injects fuel directly into the combustion chamber from a fuel injection valve facing the combustion chamber, the nozzle tip is arranged so that the spray ejected from the fuel injection valve collides with each other near the fuel injection port. A fuel supply device for an engine, characterized in that: