JPH0586888A - Cylinder injection of fuel type rotary piston engine - Google Patents

Abstract

PURPOSE:To concentrate the fuel in the leading side edge part of an actuating chamber. CONSTITUTION:The directional direction of a fuel injection valve 13 to directly inject into an actuating chamber 3 is to be in the neighbourhood of the leading side edge part of the actuating cell in an compression process. A rotor recess 21 is formed by offsetting it on the leading side rather than the central position in its rotor rotational direction on a rotor flank surface 2a, and a second recess 22 is formed on the leading side edge part of the rotor recess 21. With rotation of the rotor 2, a large vortex a revolving in the rotor rotational direction is formed in the actuating chamber 3, and a small vertex beta revolving in the opposite direction of the vortex alpha is formed on the leading side edge part. The large vortex alpha is positioned nearer to the leading side of the actuating cell 3 than usual, and the strength of the small vortex beta is increased more than usual by the second recess 22. Fuel is blocked in the small vortex beta.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder fuel injection type rotary piston engine.

[0002]

2. Description of the Related Art In a rotary piston engine, a rotor recess is formed on a rotor flank surface to secure a volume of a combustion chamber, and this rotor recess is usually arranged in a rotational direction of the rotor. -The leading side and the trailing side are formed symmetrically with respect to the center of the tough flank.

On the other hand, in the rotary piston engine, it has been proposed to inject fuel directly from the fuel injection valve into the working chamber in order to stratify the fuel and improve the fuel consumption (Japanese Patent Laid-Open No. 63-63115). -80020). After all, such in-cylinder fuel injection attempts to concentrate the fuel as much as possible on the leading side of the working chamber.

[0004]

As described above, when the fuel is directly injected into the working chamber, it is not always possible to obtain good stratification of the fuel, that is, the fuel is dispersed more widely in the working chamber than intended. It turns out that it will end up.

In pursuit of such a cause, it was found that the vortex flow generated in the working chamber during the compression stroke had a great adverse effect on the stratification of the fuel. Explaining this point in detail, due to the rotation of the rotor, a large vortex or swirl swirling in the rotation direction of the rotor is generated in the working chamber, and this swirl spreads the fuel injected into the working chamber widely. I will let you.

The present invention has been made in consideration of the above circumstances, in which fuel is directly injected into the working chamber,
An object of the present invention is to provide an in-cylinder fuel injection type rotary piston engine capable of achieving high stratification of fuel.

[0007]

In order to achieve the above object, the present invention has the following constitution. That is, in the in-cylinder fuel injection type rotary piston engine in which the fuel is directly injected from the fuel injection valve into the working chamber, the rotary recess formed on the rotor flank is the rotor rotation direction reading side. The second recess is further formed at the leading end of the rotary recess on the reading side.

[0008]

According to the present invention constructed as described above, a large vortex swirling in the rotational direction of the rotor is generated in the working chamber during the compression stroke, but the rotor recess is recessed. By forming the offset on the ding side, it is possible to prevent the fuel from diffusing to the trailing side of the working chamber due to the large vortex flow. At the same time, it was confirmed that a small vortex swirling in the direction opposite to the large vortex was generated near the leading of the working chamber during the compression stroke, but by forming the second recess, this small vortex was generated. While the strength of the vortex is strengthened relative to the strength of the large vortex, the fuel once reaching the small vortex is prevented from being trapped in the small vortex and diffusing. In this way, the fuel can be concentrated on the reading side of the working chamber as a whole,
High stratification of fuel can be realized. Preferred aspects of the invention and advantages thereof will become apparent from the description of the examples below.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, a Wankel type rotary piston engine RE has a rotor 2 housed in a rotor housing 1, and by this rotor 2 there are three working chambers 3 in a cylinder. 4, 5 are defined. The working chambers 3, 4, and 5 periodically repeat the strokes of suction, compression, expansion (explosion), and exhaust with the planetary motion of the rotor. Figure 1
In this state, the working chamber 3 is in the compression stroke, the working chamber 4 is in the expansion stroke, and the working chamber 5 is in the final stage of the exhaust stroke.

Two ignition gaps LP1 and TP1 are provided for one cylinder, that is, first and second ignition gaps LP1 and TP1. First
The ignition gap LP1 is arranged slightly ahead of the trochoid minor axis (advancing side in the rotational direction of the rotor 2-the same applies hereinafter), and the second ignition gap TP1 is located slightly behind the trochoid minor axis. .. Each ignition gap LP
1 and LP2 are respectively located at the centers in the rotor width direction (the thickness direction of the rotor 2 and the length in the engine output shaft direction).

Reference numeral 8 in FIG. 1 denotes an intake passage in which a throttle valve 9 is arranged, and its downstream end portion is connected to an intake port 11 formed in a side housing 10. A first fuel injection valve 12 for injecting fuel into the intake passage 8 is arranged in the intake passage 8. Further, the rotor housing 1 is provided with a second fuel injection valve 13 for directly injecting fuel into the cylinder. The direction in which the second fuel injection valve 13 is oriented is approximately in the vicinity of the ignition gap TP1. In addition, 14 in FIG. 1 is an exhaust passage.

In the embodiment, fuel is injected only from the second fuel injection valve 13 in the engine low speed region and the engine low load region. In a high engine speed region or a high engine load region where a sufficient fuel injection amount is required and the air utilization rate is required to be increased, both fuel injection valves 12 and 13 are provided.
Fuel is injected from. The selection of such a fuel injection mode is merely an example, and the second fuel injection valve 13 may be included.

A rotor recess 21 is formed on each of the three rotor flanks 2a as shown in FIG. The rotor recess 21 extends long in the rotor rotation direction, but as a whole, is formed offset from the center position of the rotor flank 2a in the rotor rotation direction toward the reading side. ..

A second recess 22 is further formed at the leading end of the rotor recess 21. Since the second recess 22 is further formed with respect to the rotor recess 21, the depth of the second recess 22 is different from that of the other parts of the rotor recess 2.
It is deeper than the depth of 1. And the second recess 2
The cross-sectional shape of 2 is formed such that the bottom surface thereof is a gentle arcuate surface. The recesses 21 and 22 are
The length relationship is offset so that the leading side is longer than the center position of the rotor flank surface 2a in the rotor rotation direction, and the leading side is longer than the trailing side. Is set to be larger than that on the trailing side.

In the above-mentioned structure, a large vortex flow α swirling in the rotor rotation direction is formed in the working chamber during the compression stroke, as shown in FIG. This large vortex flow [alpha] is formed at a position closer to the leading side than before by forming the rotor recess 21 by offsetting the leading side as described above.

During the compression stroke, and at the same time, the release of the working chamber
A small vortex flow β that swirls in the opposite direction to the large vortex flow α at the end on the Ding side, that is, near the second recess 22.
Is formed. The pressure distribution of the small vortex flow β in the direction of the XX line in FIG. 2 is as shown in FIG. That is, the small vortex β has the lowest pressure at the center, and the pressure increases as the distance from the center increases. By forming the second recess 22, such a small vortex flow β is formed as stronger than before.

Therefore, once the fuel injected from the second fuel injection valve 13 reaches the small vortex flow β, the fuel is confined in the small vortex flow β and the confinement action becomes strong. As a result, the air-fuel ratio in the vicinity of the leading end of the working chamber during the compression stroke becomes sufficiently rich, and high stratification of fuel can be obtained.

By the way, the release of the working chamber during the compression stroke
On the ding side, combustion gas from the working chamber during the expansion stroke is often injected through the plug hole of the trailing side ignition gap TP1, as shown in FIG.
The combustion gas injected into the working chamber during this compression stroke is called Spitzback. This Spitzback γ
Are undesirable for concentrating fuel at the leading end of the working chamber during the compression stroke. In consideration of this Spitzback γ, it is preferable to do the following in order to concentrate the fuel on the leading side end of the working chamber during the compression stroke.

First, as shown in FIG. 5, the Spitz back γ is the ignition gap TP1 portion, that is, the plug hole.
The fuel may be injected so as to avoid the ignition gap TP1 in consideration of the fact that it is through the engine. In FIG. 5, in consideration of the fact that the ignition gap TP1 is located at the center in the rotor width direction, the second fuel injection valve 13 is of a two injection hole type, and the injected fuel is injected to both sides of the ignition gap TP1. Is oriented.

In FIG. 6, as the second fuel injection valve,
Two fuel injection valves of the one injection hole type, which are separated in the rotor width direction, are provided as shown by 13A and 13B, and the fuel injected from one fuel injection valve is directed to the right side of the ignition gap TP1. The fuel injected from the other fuel injection valve is directed to the left side of the ignition gap TP1.

In FIG. 7, as the trailing side ignition gap, two ignition gaps TP1 and TP2 separated in the rotor width direction are provided as the second fuel injection valve 1.
The fuel injected from No. 3 is the two ignition gaps TP1 and T
It is directed to P2.

FIG. 8 shows the momentum of Spitzback γ
This is intended to be offset by the injection pressure of the fuel injected from the fuel injection valve 13. That is, so that they face each other with respect to Spitzback γ, that is, so that the injected combustion collides with Spitzback γ from the front as much as possible,
The fuel injected from the second fuel injection valve 13 is directed.

In FIG. 9, the directivity direction of the second fuel injection valve 13 is set so that the fuel injected from the second fuel injection valve 13 obliquely enters along the second recess 23. .. By doing this, the fuel is
This is preferable in preventing dispersion due to collision with the.

In order to keep the angle at which the fuel is incident on the bottom surface of the second recess 23 as described above, it is preferable to advance the fuel injection timing as the engine speed increases. Further, in order to keep the contact time between the fuel and the rotor 2 as much as possible (the vaporization and atomization states of the fuel are as much as possible), it is advisable to control the fuel pressure as well, that is, change the fuel injection timing. This has an effect on injecting the required fuel amount, but by changing the injection rate that indicates the injection amount per unit time, that is, by controlling the fuel pressure, it is possible to secure the required fuel amount and the desired injection timing. We can both be satisfied. Since the fuel reaches the small vortex flow β through the large vortex flow α, it is possible to shorten the fuel injection period and increase the partial fuel pressure. From this viewpoint, it is advantageous to control the fuel pressure. ..

At the time of high engine load, the temperature of the rotor recess 21, which is higher than the second recess 23, becomes high,
It easily causes knocking. Therefore, at the time of high load, the fuel injection timing may be controlled so that the fuel injected from the second fuel injection valve 13 collides with the rotor recess 21 on the trailing side of the second recess 23. ..
Of course, in order to effectively cool the rotary recess 21 with the fuel, it is preferable that the fuel flow along the bottom surface of the rotary recess 21. At the time of this high load, from the viewpoint of securing the engine output, it is an operating region where it is required to sufficiently promote the vaporization and atomization of the fuel in order to increase the air utilization rate and to disperse the fuel widely in the working chamber. The point of stratification does not need to be particularly considered.

FIG. 10 shows a control system diagram for controlling the fuel injection timing and the fuel pressure as described above. In FIG. 10, 31 is a fuel path, 32 is a pump, 33 is an electromagnetic fuel pressure adjusting valve, and the second fuel injection valve 13 is connected to the fuel path 31 between the pump 32 and the fuel pressure adjusting valve 33. There is.
U is a control unit configured by using a microcomputer, and the control unit U controls the second fuel injection valve 13 and the fuel pressure adjusting valve 33. Of course, the control unit U receives signals from the sensors S1 to S3 that detect the engine speed, the engine load, and the crank angle.

In FIG. 11, the second fuel injection valve 51 is connected to the tray.
It is provided at the position of the ring side ignition gap TP1. That is, it corresponds to the one shown in FIG. 1 in which the second fuel injection valve 13 is changed to the position of the ignition gap TP1 in FIG. Further, as shown in an enlarged manner in FIG. 12, a collision plate 52 made of a perforated plate is arranged immediately in front of the second fuel injection valve 51 as shown in FIG. This collision plate 52
Is arranged so as to cover the hole 53 for mounting the second fuel injection valve 51 (which is the form of covering the plug hole of the ignition gap TP1 in FIG. 1).

In FIG. 11, the second fuel injection valve 1
The fuel injected from No. 3 does not need to traverse a large vortex flow α, which is preferable for further enhancing the stratification of the fuel. The collision plate 52 also promotes vaporization and atomization of fuel. Further, the collision plate 52 can reduce spits back.

[Brief description of drawings]

FIG. 1 is an overall view showing an embodiment of the present invention.

FIG. 2 is a diagram showing a vortex flow formed in a working chamber.

FIG. 3 is a diagram showing a pressure distribution of a small vortex flow.

FIG. 4 shows another embodiment of the present invention.
Figure corresponding to.

5 is a simplified cross-sectional view taken along line X5-X5 of FIG.

FIG. 6 shows another embodiment of the present invention.
Figure corresponding to.

FIG. 7 shows another embodiment of the present invention.
Figure corresponding to.

FIG. 8 shows another embodiment of the present invention.
Figure corresponding to.

FIG. 9 shows another embodiment of the present invention.
Figure corresponding to.

FIG. 10 is a control system diagram of a fuel injection valve.

FIG. 11 shows another embodiment of the present invention,
The figure corresponding to FIG.

12 is an enlarged cross-sectional view of the main parts of FIG.

FIG. 13 is a plan view of a collision plate.

[Explanation of symbols]

 U: Control unit α: Large vortex β: Small vortex γ: Spitzback 1: Rotor housing 2: Rotor 2a: Rotor flank surface 3, 4, 5: Working chamber 10: Side housing 13: Second fuel Injection valve 21: Rotor recess 22: Second recess 51: Fuel injection valve 52: Collision plate LP1: Ignition gap (reading side) TP1, TP2: Ignition gap (trailing side)

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shogo Watanabe 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Motor Corporation

Claims (12)

[Claims] 1. In a cylinder fuel injection type rotary piston engine in which fuel is directly injected from a fuel injection valve into a working chamber, a rotor recess formed on a rotor flank has a rotor rotation direction recess. An in-cylinder fuel injection type rotary piston engine, which is formed to be offset on the bearing side, and further has a second recess formed on the leading end of the rotary recess on the leading side. 2. The ignition gap according to claim 1, wherein the ignition gap is located slightly ahead of the trochoid minor axis, and the fuel injection valve is located slightly behind the trochoid minor axis. 3. The collision plate according to claim 2, wherein a collision plate against which fuel from the fuel injection valve collides is arranged in front of the fuel injection valve. 4. The direction of the fuel injected from the fuel injection valve is opposed to the combustion gas injected from the working chamber in the explosion stroke to the working chamber in the compression stroke through the plug hole. Those that are set to collide from the direction you do. 5. The directing direction of fuel injected from the fuel injection valve according to claim 1, does not collide with combustion gas injected from the working chamber in the explosion stroke to the working chamber in the compression stroke through the plug hole. What is supposed to be the direction. 6. The fuel injection system according to claim 5, wherein the fuel injected from the fuel injection valve is directed toward both sides of the plug hole. 7. The ignition gap according to claim 5, wherein two ignition gaps are provided at intervals in the rotor width direction, and the direction of the fuel injected from the fuel injection valve is between the two ignition gaps. What is supposed to be the position. 8. The fuel injection system according to claim 1, wherein the direction of the fuel injected from the fuel injection valve is such that the fuel flows along the bottom surface of the second recess. 9. The fuel from the fuel injection valve according to claim 8, wherein the position of arrival of the fuel injected from the fuel injection valve at the rotor flank is constant in accordance with the operating state of the engine. The one in which the injection state is controlled. 10. The fuel injection state according to claim 9, wherein the fuel injection state from the fuel injection valve is a fuel injection timing. 11. The fuel injection state according to claim 9, wherein the fuel injection state from the fuel injection valve is a fuel pressure. 12. The engine according to claim 1, wherein when the engine is under a high load, the fuel injected from the fuel injection valve collides with a rotor recess located in front of the second recess. Fuel injection timing is controlled.