JPH0587016A - Fuel injection device for rotary piston engine - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] Considering the swirl direction of the intake air, depending on the operating state, or in the case of multiple cylinders Optimize the swirl direction. [Structure] Two air passages 22 are provided in a fuel passage 14 communicating with a fuel injection port 14a opened in a side housing 10.
A and 22B are connected, and on-off valves V1 and V2 are connected to each. When the on-off valve V1 is opened and air is supplied from the air passage 22A, the fuel swirl β is set in the same direction as the intake swirl α generated in the cylinder according to the rotation of the rotor 2, and the intake air This is preferable for stratifying the fuel because the diffusion effect of the fuel by the swirl α is suppressed, and when the on-off valve V2 is opened and air is supplied from the air passage 22B,
The swirl β of the fuel is formed in the direction opposite to the swirl α of the intake air, and the diffusion action of the fuel by the swirl α of the intake is strengthened, which is preferable in promoting the vaporization and atomization of the fuel. The mechanism is mounted on the fuel injection port 14a.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a rotary piston engine, as disclosed in Japanese Utility Model Application Laid-Open No. 2-241977, direct fuel injection into a cylinder is disclosed. More specifically, the fuel injection port is opened in the side housing, and the fuel injected from this fuel injection port is concentrated near the spark plug. Such direct injection of fuel into the cylinder is preferable in terms of combustion stability and responsiveness due to stratification of fuel.

Further, in the above publication, in order to promote vaporization and atomization of the fuel injected from the fuel injection port opened in the side housing as much as possible, the fuel injected from the fuel injection port is parallel to the inner surface of the side housing. It is also disclosed that a swirl shape is formed in a plane.

[0004]

As described above, when the fuel from the fuel injection port opened in the side housing is swirled in a plane parallel to the inner surface of the side housing,
It has been found that there are cases where the fuel spreads more widely in the cylinder, that is, in the working chamber than intended, and the stratification of the fuel is disturbed.

In the side housing, an intermediate housing defining the first cylinder and the second cylinder is opened with a first fuel injection port for the first cylinder and a second fuel injection port for the second cylinder. It has also been found that when a common fuel injection valve having a fuel swirl generation mechanism is installed in each of the fuel injection ports, the combustion state is different between the two cylinders.

In pursuit of the cause of the above problems, it was found that the swirl of intake air generated in the cylinder due to the rotation of the rotor had an influence.
Explaining this point in detail, due to the rotation of the rotor, an intake air swirl that swirls in the rotational direction of the rotor occurs from the intake stroke to the compression stroke. The intake swirl and the fuel swirl come into contact with each other, but both swirls
It was found that the fuel is less diffused when the swirl directions are the same, and the fuel is largely diffused when the swirl directions are opposite to each other.

That is, the reason why the fuel is diffused wider than intended is that the intake air swirl direction and the fuel swirl direction are large.
It is when the fuel swirl direction is opposite to the intake swirl direction between the two cylinders that the combustion state is different between the two cylinders. It is because of the relationship.

The present invention has been made in consideration of the above circumstances, and is a fuel for a rotary piston engine in which an appropriate swirl direction of fuel can be set in consideration of the swirl direction of intake air. An object is to provide an injection device.

In order to achieve the above object, the present invention has the following as a first configuration thereof. That is, in the rotary piston engine in which the fuel injection port is opened in the side housing and the fuel is injected in a swirl shape in a plane parallel to the inner surface of the side housing from the fuel injection port, the swirling of fuel is performed. The configuration is such that the roll direction is set to be the same as the swirl direction of intake air in the cylinder generated by the rotation of the rotor.

The present invention has the second configuration as follows. That is, in the rotary piston engine in which the fuel injection port is opened in the side housing and the fuel is swirled and injected from the fuel injection port in a plane parallel to the inner surface of the side housing, the fuel injection port The swirl direction changing means for changing the swirl direction of the fuel from the engine, and the swirl direction changing means for controlling the swirl direction to change the swirl direction of the fuel according to the operating state of the engine. And a direction control means.
The engine operating state may be engine load.

In order to achieve the above-mentioned object, the present invention has the following third construction. That is, in the rotary piston engine in which the fuel injection port is opened in the side housing, and the fuel is swirled and injected from the fuel injection port in a plane parallel to the inner surface of the side housing, The swirl direction of the fuel with respect to the swirl direction of intake air in the cylinder generated by the rotation is set to be the same in each cylinder.

In the case of the above-mentioned third construction, the intermediate housing which defines the first cylinder and the second cylinder in the side housing is provided with the first fuel injection port for the first cylinder and the first fuel injection port for the first cylinder. When the second fuel injection port for the second cylinder is formed, the swirl direction of the fuel from the first fuel injection port and the second direction when the fuel injection direction from the fuel injection port is used as a reference. If the swirl direction of the fuel from the fuel injection port is set to be opposite to each other, as a result, the swirl direction of the fuel is the same as the swirl direction of the intake air between the cylinders. ..

[0013]

According to the first structure of the present invention, while the fuel is swirled, the vaporization and atomization of the fuel can be appropriately promoted, while the fuel is prevented from excessively diffusing in the cylinder, and the fuel is stratified. Can do enough

According to the second structure, it is possible to satisfy both the request for fuel vaporization and atomization promotion depending on the engine operating condition, particularly engine load, and the request for fuel stratification.

According to the third structure, it is possible to prevent a difference in combustion state between the cylinders and obtain the same combustion state for each cylinder.

[0016]

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 plugs 6, 7 are provided for one cylinder, that is, first and second ignition plugs 6, 7. The first spark plug 6 is located slightly ahead of the trochoid minor axis (advancing side in the rotational direction of the rotor 2-the same applies hereinafter), and the second spark plug 7 is located slightly behind the trochoid minor axis. ing.

Indicated at 8 in FIG. 1 is an intake passage extending from an air cleaner (not shown), and an intake port 9 is provided at the downstream end thereof.
It is connected to. The intake passage 9 includes the intake passage 9
A first fuel injection valve 11 for injecting fuel is arranged inside. Further, the side housing 10 is provided with a second fuel injection valve 12 for directly injecting fuel into the cylinder. Because of the fuel supply from the second fuel injection valve 12,
A fuel passage 14 is formed in the side housing 10, and a downstream end of the fuel passage 14 serves as a fuel injection port 14a.

An air pump 21 is provided for the intake system. The air pump 21 is driven by the engine RE via an electromagnetic clutch (not shown) and is led out from the intake passage 8 upstream of the throttle valve 15. Is connected to the air passage 22. The air from the air passage 22 is branched into two on the way, and each branch air passage 22A, 22B
Are connected to the fuel passages 14, respectively. And
An electromagnetic first on-off valve V1 is connected to the branch air passage 22A, and an electromagnetic second on-off valve V2 is connected to the branch air passage 22B.
Are connected. In addition, 31 in FIG. 1 is an exhaust passage.

The branch air passages 22A and 22B and the on-off valves V1 and V2 are for changing the swirl direction of the fuel injected from the fuel injection port 14a. The mechanism of the swirl direction changing portion of the fuel will be described with reference to FIGS.

First, in FIG. 2, reference numeral 41 denotes a casing which constitutes the fuel metering portion 12a of the second fuel injection valve 12. In this casing 41, one fuel passage 42 and two air passages 43A are provided. , 43B are formed. Below the casing 41, a casing 44 having a swirl generating mechanism, which will be described later, is arranged.
One fuel passage 45 and two air passages 46A and 46B are formed. The fuel passages 42 and 45 are connected to the pipe 4
7 and the air passages 43A and 46A are connected to each other by the pipe 48
The air passages 43B and 46B are connected to each other by a pipe 48
Connected at B.

The fuel passage 42 is connected to the fuel metering portion 12a of the second fuel injection valve 13, and the fuel passage 45 is connected to a check valve 51 mounted on the casing 44. As a result, the fuel injected from the second fuel injection valve 12 is
The check valve 51 is pushed open by the fuel pressure and is injected to the outside from the injection port 52 opened leftward in FIG. Of course, the injection port 52 is located at the fuel injection port 14a, and the injection port 5
The pointing direction of 2 is almost matched with the engine output shaft direction.

The air passage 43A is connected to the air passage 22A, that is, the on-off valve V1, and the air passage 43B is
It is connected to the air passage 22B, that is, the on-off valve V2.
An annular sleeve 61 is fitted and held on the inner peripheral surface of the injection port 52 on the downstream side of the check valve 51,
The air passages 46A and 46B are connected to the sleeve 61 as described later.

As shown in FIGS. 3 and 4, a sleeve 61 is provided.
Are spaced apart from each other in the axial direction of the injection port 52 by the first
It has annular passages 62A and 62B. As shown in FIG. 3, the first annular passage 62A is connected to the air passage 46A connected to the opening / closing valve V1. Then, the first annular passage 62
A is opened in the injection port 52 via a plurality of radiation passages 63A formed so as to extend in the tangential direction of the injection port 52. Due to this radiation passage 63A, the air that has passed through the on-off valve V1 and passed through the first annular passage 62A and then ejected from the radiation passage 63A is swirling in the clockwise direction in FIG. 3 in a plane parallel to the inner surface of the side housing. It becomes a swirl.

As shown in FIG. 4, the second annular passage 62B.
Is connected to an air passage 46B connected to the on-off valve V2. The second annular passage 62B is opened in the injection port 52 via a plurality of radiation passages 63B formed so as to extend in the tangential direction of the injection port 52. This radiation passage 63B passes through the on-off valve V2, and the second annular passage 6
The air jetted from the radiation passage 63B after passing through 2B becomes a swirl flow or swirl in the counterclockwise direction in FIG. 4, but the swirl direction at this time is the opposite direction to that shown in FIG. Becomes

As can be understood from the above description, depending on which one of the on-off valves V1 and V2 is opened,
The swirl direction of the air jetted from the jet port 52 is changed. The fuel injected from the injection port 52 is also swirled by the influence of the swirl air, and the swirling direction is the same as the swirl direction of the air. The lower portion of the assembly AB such as the fuel injection valve 12 as shown in FIG. 2 is formed to be elongated as a whole, and is inserted into the fuel passage 14 so that the injection port 52 is aligned with the fuel injection port 14a. , Retained.

Referring again to FIG. 1, the swirl of the intake air generated in the working chamber 3 due to the rotation of the rotor 2 is indicated by the symbol α, and is injected from the fuel injection port 14a (injection port 52). The swirl of fuel is indicated by the symbol β. In FIG. 1, both swirls α and β are in the same direction, and in such a relationship, the fuel injected from the fuel injection port 14a is hardly diffused by the swirl of intake air, and This is a preferable state for achieving stratification. Thus, the directions of the swirls α and β are the same as each other.
When the fuel is swirling as shown in FIG. 3, that is, when the on-off valve V1 is opened.

When the direction of the fuel swirl β is opposite to that shown in FIG. 1, the fuel is greatly diffused by the intake swirl α to promote the vaporization and atomization of the fuel. It will be preferable from the above. Thus, swirl α and β
The directions of and are opposite to each other, as shown in FIG.
That is, it is when the on-off valve V2 is opened.

Here, the fuel injection timing of the first fuel injection valve 11 is set, for example, when the intake port 9 is opened. Further, as shown in FIG. 1, the fuel injection timing of the second fuel injection valve 12 is set to a fuel injection timing at which the rotor 2 does not close the fuel injection port 14a during the compression process. ..

FIG. 5 shows a housing portion of a two-cylinder rotary piston engine, and shows an example in which combustion states of both cylinders are not different from each other. In FIG. 5, the engine housing includes a side housing 71, a rotor housing 72, a side housing (intermediate housing) 73, and a rotor housing 7 in order from left to right.
4, formed by the side housing 75. By the housings 71, 72 and 73, the first cylinder RE
1, and the housings 73, 74, and 75 form a second cylinder RE2.

In the intermediate housing 73 which defines the cylinders RE1 and RE2, fuel passages 76A,
76B (corresponding to 14) is formed, and its downstream side end is opened to the first cylinder RE1 or the second cylinder RE2 as fuel injection ports 77A and 77B (corresponding to 14a). Then, in the fuel passages 76A and 76B, assemblies 78A and 78B corresponding to the assembly AB of the fuel injection valve as shown in FIG.
Is inserted and held.

However, the directions of the fuel swirl β by the assemblies 78A and 78B are opposite to each other.
That is, assuming that the injection port 52 is viewed from the left in FIG. 2, if the swirl β of the fuel from the assembly 78A is clockwise, the swirl of the fuel from the assembly 78B is clockwise. The counter direction is counterclockwise. In other words, using the assembly AB having the same specifications as shown in FIG.
8A and 78B, if one assembly 78A opens V1, the other assembly 78B opens V2.

With this setting, the direction of the fuel swirl β with respect to the direction of the intake swirl α is determined by the two cylinders R.
It becomes the same between E1 and RE2. In other words,
When the direction of the intake swirl α and the direction of the fuel swirl β in the first cylinder RE1 are set to be the same direction, the direction of the intake swirl α in the second cylinder RE2 is also set. And the direction of the fuel swirl β are the same.

It is preferable to change the direction of the fuel swirl β with respect to the direction of the intake swirl α according to the operating condition of the engine. An example of this change will be described with reference to FIG. The overall configuration for fuel injection is based on the case of FIG.

First, in FIG. 6, U is a control unit constructed by using a microcomputer. In FIG. 4, the input / output relationship to each of the above-described components is shown. In FIG. 4, reference numeral S1 is a sensor for detecting intake pressure as an engine load, S2 is a sensor for detecting an engine speed, S3 is a water temperature sensor for detecting the cooling water temperature, S3
Reference numeral 4 is a throttle opening sensor.

The control unit U basically stores a map as shown in FIG. 7 and selects a fuel injection valve to execute fuel injection. In FIG. 7, “M
"I" indicates when fuel injection from the first fuel injection valve 11 is performed, and "SDI" indicates when fuel injection from the second fuel injection valve 12 is performed. As understood from FIG. 7, the second fuel injection valve 1
Fuel injection is always performed from No. 2, but fuel injection from the first fuel injection valve 11 may be stopped.

Further, in FIG. 7, what is shown as "forward direction" is the case where the direction of the swirl β of the fuel from the second fuel injection valve 12 is the same as the direction of the swirl α of the intake air, and Shown as "reverse direction" is when the directions of both swirls α and β are opposite.

FIG. 7 shows a basic state after the engine has been warmed up. When the engine is cold (when the water temperature is less than 60 ° C. in the embodiment) where vaporization and atomization are insufficient, FIG. Preferentially, the mode is changed as shown in FIG. The conditions shown in FIG. 8 are also stored in the control unit U.
The setting as shown in FIGS. 7 and 8 is a request according to the operating state of the engine, that is, an operating state that gives priority to promotion of vaporization and atomization, or an operating state that gives priority to fuel stratification. It is done from the viewpoint.

Next, the control contents of the control unit U will be described with reference to the flowchart of FIG.
In the following description, P indicates a step. First, at P1, after the signals from the sensors S1 to S4 are read,
In 2, it is determined whether or not it is during acceleration. This determination is performed, for example, by checking whether or not the rate of change in the direction in which the throttle opening becomes larger is a predetermined value or more. If YES in the determination of P2, in P8,
The fuel is injected from both fuel injection valves 11 and 12, and the swirl direction of the fuel from the fuel injection port 14a is in the opposite direction (vaporization and atomization promotion for securing increased fuel quantity and output during acceleration). ).

If NO in P2, it is determined in P3 whether the water temperature is 30 ° C. or lower. Even if YES in the determination of P3, the process proceeds to P8. If NO in P3, in P4, the second fuel injection valve 12
It is determined whether or not the fuel injection is performed only from, that is, whether or not the hatched operation state of FIG. Even if the determination in P4 is NO, the process proceeds to P8.

When the determination in P4 is YES, it is determined in P5 whether or not the intake pressure is a high load of -200 mHg or more. If YES in the determination of P5, the process proceeds to P9, the fuel is injected from the second fuel injection valve 12, the opening / closing valve V2 is opened, and the swirl β of the fuel is set in the opposite direction. It

If NO in P5, it is determined in P6 whether the water temperature is 60 ° C. or lower. When the determination in P6 is YES, the process shifts to P9. If NO in P6, the fuel is injected from only the second fuel injection valve 12 in P7, and the on-off valve V1 is opened to swirl the fuel in the forward direction.

Although the embodiment has been described above, the second fuel injection valve 12 only, that is, the fuel may be supplied only from the fuel injection port 14a. If both the on-off valves V1 and V2 are opened, the fuel injection port 14
Since it is possible to inject the fuel from a without swirling, it is possible to select fuel injection without swirling depending on the operating state of the engine.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing an example of a mechanism for changing the direction of swirl of fuel.

3 is a sectional view taken along line X3 of FIG. 2, showing a sleeve for setting the swirl direction of the fuel.

FIG. 4 is a sectional view taken along the line X4 in FIG. 2, showing a sleeve for setting the swirl direction of fuel.

FIG. 5 is a side sectional view showing setting of fuel in a swirl direction in a two-cylinder rotary piston engine.

FIG. 6 is a control system diagram showing an input / output relationship with a control unit.

FIG. 7 is a diagram schematically showing basic control contents by a control unit.

FIG. 8 is a diagram showing a control content according to a water temperature by a control unit.

FIG. 9 is a flowchart showing a control example of the present invention.

[Explanation of symbols]

 U: Control unit RE: Engine RE1: First cylinder RE2: Second cylinder α: Intake swirl β: Fuel swirl 2: Rotor 3, 4, 5: Working chamber 10: Side housing 11: First fuel injection valve 12: Second fuel injection valve 14: Fuel passage 14a: Fuel injection port 21: Air pump 22: Air passage 22A: Branch air passage 22B: Branch air passage V1: Open / close valve (normal swirl of fuel) V2: Open / close valve (for reverse direction of fuel swirl) 73: Intermediate housing 77A: Fuel injection port 77B: Fuel injection port

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F02M 51/08 K 7226-3G 69/00 310 L 9248-3G 69/46 69/04 L 9248- 3G (72) Inventor Kazuhiro Shiomi 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Motor Corporation

Claims (5)

[Claims] 1. A rotary piston engine in which a fuel injection port is opened in a side housing, and the fuel is swirled and injected from the fuel injection port in a plane parallel to the inner surface of the side housing. Is set so that the swirl direction of the engine is the same as the swirl direction of intake air in the cylinder generated by the rotation of the rotor. .. 2. A rotary piston engine in which a fuel injection port is opened in the side housing, and the fuel is swirled and injected from the fuel injection port in a plane parallel to the inner surface of the side housing. The swirl direction changing means for changing the swirl direction of the fuel from the fuel injection port, and the swirl direction changing means are controlled to change the swirl direction of the fuel according to the operating state of the engine. A device further comprising swirl direction control means. 3. The engine according to claim 2, wherein the operating state of the engine is engine load. 4. A rotary piston engine in which a fuel injection port is opened in a side housing, and fuel is swirled and injected from the fuel injection port in a plane parallel to the inner surface of the side housing. -The swirl direction of the fuel is set to be the same in each cylinder with respect to the swirl direction of the intake air in the cylinder generated by the rotation of the cylinder. 5. The intermediate housing, which defines a first cylinder and a second cylinder of the side housing, according to claim 4, and a first fuel injection port for the first cylinder, and a second fuel injection port for the first cylinder. A second fuel injection port for a cylinder is formed, and a swirl direction of fuel from the first fuel injection port based on the fuel injection direction from the first fuel injection port;
The swirl direction of the fuel from the second fuel injection port based on the fuel injection direction from the fuel injection port is set to be opposite to each other.