JPS63227928A - Scavenging device of rotary piston engine - Google Patents

Abstract

PURPOSE:To improve the scavenging efficiency of the engine in the caption by arranging a 2-fluid injection type injection nozzle directly facing to an operation chamber to make it possible to supply only compressed air from an injection nozzle to the operation chamber installed in an intake/discharge overlap area during the overlap period of intake/discharge strokes. CONSTITUTION:A 2-fluid injection method by which fuel is injected with air pressure is used as a fuel injection means 31 interposed in a fuel supply system 16 and said means 31 is constituted by connecting a pressurizing means 33 which supplied air pressure and an injection nozzle 34 which injects fuel to a performing chamber 3, to a metering unit 32. The metering unit 32 has a metering chamber which stores a required amount of fuel and a regulator which change the capacity of sai chamber and said unit 32 is constructed to discharge fuel from the pressurizing means 33 in response to application of air pressure at predetermined timing. In the overlap period of the intake/discharge strokes, said unit 32 is controlled to supply only compressed air from the injection nozzle 34 to the operation chamber 3 installed in the intake/discharge overlap area.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is directed to a rotary piston engine which is adapted to reduce dilution gas.

(Prior Art) Conventionally, as a fuel injection device for a rotary piston engine, as disclosed in Japanese Patent Publication No. 52-19612, for example, an auxiliary suction port is provided near the suction boat of the casing, and an auxiliary suction port is provided on the leading side in the rotational direction of the rotor. A fuel injection nozzle is provided between the auxiliary intake boat and the intersection point where the center line of the auxiliary intake bow 1 intersects with the inner peripheral surface of the trochoid, and the fuel injected from the fuel injection nozzle is injected into the auxiliary intake boat. It is known that a stratified air-fuel mixture is formed by atomizing the flow of air sucked in from the air, and stratification of this air-fuel mixture improves combustibility and reduces fuel consumption.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional rotary piston engine, during the overlap period of the intake and exhaust strokes, due to the pressure difference between the exhaust pressure and the intake pressure, the exhaust gas flows through the working chamber in the overlap region. Exhaust air flows from the port to the intake boat, and this exhaust gas is brought into the working chamber along with the intake air as dilution gas during the intake stroke, so this dilution gas deteriorates the combustibility of the air-fuel mixture and causes it to become stratified with the air-fuel mixture. The problem arises that the meaning is lost.

Therefore, an idea is to supply compressed air to the exhaust port during the overlap period of the exhaust stroke, and replace the exhaust gas flowing from the exhaust port to the intake boat with this compressed air, thereby suppressing the introduction of dilution gas into the working chamber. It will be done. but,
In this case, since compressed air is supplied to the exhaust port, when air-fuel ratio control is performed based on 11 degrees of oxygen in the exhaust gas, a problem arises in that the air-fuel ratio cannot be detected accurately.

The present invention has been made in view of these points, and its purpose is to use a so-called two-fluid injector, which injects fuel using air pressure at °C as a fuel injection means and is characterized by excellent fuel atomization performance. By injecting fuel and compressed air directly into the working chamber at appropriate timing from the two-fluid injector, the introduction of dilution gas into the working chamber can be suppressed without impairing the air-fuel ratio detected by the 02 sensor. The objective is to effectively stratify the air-fuel mixture in the working chamber.

(Means for Solving the Problems) In order to achieve the above object, the present invention uses a two-fluid injector to inject and supply a mixture directly to the working chamber, and compresses it from an injection nozzle during the overlap period of the intake and exhaust strokes. The purpose is to supply only air to the working chamber in the intake/exhaust overlap area, and use this compressed air to prevent dilution gas from waiting from the exhaust port to the intake boat.

Specifically, the solution taken by the present invention includes an injection nozzle provided directly facing the working chamber, a fuel metering chamber provided in the fuel supply system of the engine for storing a required amount of fuel, and the metering chamber. a fuel inlet provided in the chamber for introducing fuel into the chamber; a fuel outlet provided in the chamber for returning excess fuel from the chamber to the fuel supply system;
A joint body for changing the volume of the metering chamber; a fuel outlet for discharging the fuel stored in the metering chamber to the injection nozzle; and a pressurizing means for discharging the fuel from the fuel discharge port by applying air pressure so as to inject the fuel into the working chamber, and a fuel injection means for injecting the mixture of fuel and compressed air from the injection nozzle into the working chamber. and a control means for controlling the fuel injection means so as to supply only compressed air from the injection nozzle to the working chamber in the intake and exhaust overlap region during the overlap period of the intake and exhaust strokes. be.

<Function> With the above configuration, in the present invention, when the working chamber is in the intake stroke or the compression stroke, a mixture of fuel and compressed air is supplied from the injection nozzle, and the fuel is well atomized by the compressed air. A uniform air-fuel mixture is formed in the working chamber.

Also, during the overlap period of the intake and exhaust strokes, only compressed air is supplied from the jet tJ4 nozzle to the working chamber in the intake and exhaust overlap region, and this compressed air blocks the flow of exhaust from the exhaust port to the intake boat, Dilution gas is suppressed from being brought into the working chamber.

Furthermore, compressed air is supplied to the working chamber in the intake/exhaust overlap region i from the injection nozzle located on the leading side in the rotational direction, and compressed air is not supplied to the exhaust port as in the past, so when controlling the air-fuel ratio. The air-fuel ratio detection accuracy is not impaired.

(Example) Embodiments of the present invention will be briefly described below with reference to the drawings.

FIG. 1 shows a rotary piston engine equipped with a scavenging device according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a casing consisting of a rotor housing 1a having a trochoidal inner peripheral surface and side housings 1b and lb arranged on both sides of the rotor housing 1a. is arranged, and the rotor 2 makes a planetary rotation movement to cause the three working chambers 3.3.3 defined within the casing 1 to sequentially perform the intake, compression, explosion, and exhaust strokes. .

Reference numeral 4 denotes an intake passage 7 whose one end communicates with the atmosphere via the air cleaner 5 and whose other end is connected to an intake boat 6 that opens into the working chamber 3 during the intake stroke to supply intake air to the engine.
is an exhaust passage whose one end is connected to the exhaust boat 8 which opens into the working chamber 3 during the exhaust stroke, and whose other end is opened to the atmosphere for discharging exhaust gas. A throttle valve 9 is disposed in the middle of the intake passage 4 to control the amount of intake air. Incidentally, reference numerals 10 and 10 are leading-side and trailing-side spark plugs for igniting the air-fuel mixture in the working chamber 3.

Reference numeral 16 denotes a fuel supply system for supplying fuel to the engine, and the fuel supply system 1G includes a fuel tank 21 and a fuel injection means 31 connected by a fuel outgoing pipe 22 and a returning fuel pipe 23. A filter 24, a fuel pump 25, and a regulator 26 are connected to the outgoing pipe 22 from the fuel tank 21 side.
are interposed in order. The fuel that has passed through the filter 24 is pressurized by a fuel pump 25, the pressure is adjusted by a regulator 26, and the fuel is supplied to the fuel injection means 31.

The fuel injection means 31 employs a two-fluid injection method in which fuel is injected by air pressure, and the metering unit 32
a pressurizing means 33 for supplying air pressure to the working chamber 3 and a pressurizing means 33 for supplying air pressure to the working chamber 3;
An injection nozzle 34 is connected to the injection nozzle 34 for injection into the air. The injection nozzle 34 is disposed in the rotor housing 1a at a position facing the working chamber 3 in the second half of the intake stroke or the second half of the compression stroke so that its injection hole faces substantially in the direction of the spark plug 10.10. As shown in FIG. 2, the metering unit 32 mixes fuel and pressurized air, and a fuel metering chamber 36 is formed in the casing 35, and the metering chamber 36 stores the required amount of moldy fuel. It is configured as follows. The casing 35 is provided with a fuel port 37 and a fuel outlet 38 on the side, and a fuel outlet 39 on the bottom, opening into the metering chamber 36, as well as an adjustment hole 40 for the metering chamber 36. ing. The fuel inlet 37 is configured to introduce fuel into the metering chamber 36, and the fuel outlet 38 is configured to return excess fuel from the metering chamber 36 to the fuel supply system 16, respectively, with the valves of the on-off valves 41, 42. Room 418
．． 42a. The respective closed valves 41, 42 are formed by valve bodies 41C, 42C fixed to the front surfaces of diaphragms 41b, 42b that partition the valve chambers 41a, 42a into a fuel side and a pneumatic side. Entrance 3
7 and fuel outlet 38 are configured to close V#. Further, the F mixing valve chambers 41a, 42a have a fuel inlet passage 43 and a fuel outlet passage 44 on the fuel side partitioned by diaphragms 41b, 42b, and a pneumatic boat 45.4 on the pneumatic side.
6 are each spaced. The inflow path 43 is connected to the outgoing pipe 22 of the fuel supply system 16, and the outflow path 44 is connected to the incoming pipe 23. When the valve bodies 41G and 42C are open, fuel flows into the metering chamber 3G and the fuel tank 22.
It circulates between 1 and 1.

Further, although not shown, the pressurizing means 33 is connected to the pneumatic boats 45, 46, and pneumatic pressure acts on each of the valve chambers 41a, 42a in synchronization with the fuel injection timing, and pressurizes each of the diaphragms 41b.

42b is displaced to open and close the fuel port 37 and fuel outlet 38 (see FIG. 2). The volume of the 17 chamber 36 is changed, and it is composed of a regulating pipe 47 and an air control valve 48. , the inside of the adjustment pipe 47 is an air passage 47a.
The lower end opens into the measuring chamber 3G, and the pressurizing means 33 is connected to the air passage 47a. The air control valve 48 has a valve body 48b fixed to the lower end of a rod 48a through which the regulating pipe 47 is passed through, and the valve body 48b is configured to open and close the opening at the lower end of the regulating pipe 47. Further, although not shown, the adjustment valve 40 is connected to a stepping motor, etc., and moves up and down according to the engine load, etc., while the air control valve 48
Although not shown, is connected to an electromagnetic solenoid or the like, and is configured to open the air passage 47a in synchronization with the fuel supply timing.

The fuel discharge port 39 supplies fuel via the check valve 49! 50 is connected to the supply pipe 50, and one injection nozzle 1 is connected to the supply pipe 50.
5 is connected. Then, the fuel stored in the metering chamber 36 passes through the outlet 39 to the injection nozzle 1.
5 is injected into the working chamber 3.

The pressurizing means 33 is configured to supply high-pressure air pressurized by the air pump 51 to the air passage 47a of the adjustment valve 40, and discharge fuel from the discharge port 39 at the timing when the air control valve 48 is opened. ing. The discharge side of the air pump 51 is connected to the air passage 47 of the regulating valve 40 via an air supply pipe 52 and a regulator 53 and an accumulator 54.
A is connected to the regulator 53 to supply high pressure air to the regulator 53.
After the pressure is adjusted by the accumulator 54 and the pressure change FJJ is absorbed by the accumulator 54, it is supplied to the air path 47a.

On the other hand, the suction side of the air pump 51 is connected to the intake passage 8 via an air suction pipe 55 to suck in air, and the air pump 51 is connected to an eccentric shaft 56 of the engine and driven by the power of the engine. ing.

Further, 61 is a rotation speed sensor that detects the engine rotation speed;
Reference numeral 62 is provided in the exhaust passage 7 to remove oxygen a from the exhaust gas.
r! Detects the air-fuel ratio of the engine mixture from one component 0
2 sensor 63 is an air flow sensor that is provided in the intake passage 4 upstream of the throttle valve 9 and detects the amount of intake air.
The information is inputted to a control unit 70 that includes the following. Then, the output of the control unit 70 (=the drive control of the fuel pump 25 by the bow, and the vertical movement of the adjustment valve 40 of the metering unit 32,
Air is provided by Jolt valves 48 valves in 8 shifts and opening/closing pieces 41 and 42.
The operation of the air pump 51 is controlled, and the drive of the air pump 51 is also controlled.

Next, the control and operation of the fuel injection means 31 will be explained.

First, in the fuel supply system 16, fuel that has passed through the filter 24 from the fuel tank 21 is suctioned and pressurized by the fuel pump 25, and then is sent to the fuel injection means 3 via the regulator 26.
1 metal ring knit 32. In the metering unit 32, except for the fuel injection means, the on-off valves 41 and 42 open the fuel inlet 37 and the outlet 38, while the air control valve 48 closes the air passage 47a, and the fuel flows through the outgoing pipe 22 and Fuel enters the metering chamber 36 from the fuel inlet 37 through the inflow channel 43 . When this metering chamber 36 is filled with fuel, excess fuel flows out from the fuel outlet 38 and returns to the fuel tank 21 through the outflow path 44 and the return pipe 23.
1 and the metering chamber 36 at all times.

On the other hand, the air pump 51 in the pressurizing means 33 sucks intake air in the intake passage 8, pressurizes it, and discharges compressed air. air passage 47
It is supplied to a.

After that, when the fuel injection timing comes, the air pump 5
The compressed air from 1 acts on the diaphragms 41b and 42b of both n leap valves 41 and 42, resulting in the fuel population 37 and the fuel outlet 38.
At the same time, the air control valve 48 is lowered to open the air passage 47a (see FIG. 2). Then, compressed air flows into the metering chamber 36 from this air passage 47a, and the fuel stored in the metering chamber 36 is transferred to the fuel outlet 36.
9, and the fuel is pulverized with compressed air and injected into the working chamber 3 from the injection nozzle 15.

When this injection timing ends, both on-off valves 41 and 42
At the same time as opening the fuel population 37 and outlet 38 again,
Air control valve 48 closes air passage 47a and the above operation is repeated.

Next, the basic operation of the fuel injection means 31 mentioned above will be explained with reference to the control flow shown in FIG.

First, in step S1, the system is initialized to clear, for example, the fuel injection period. Next, the process moves to step S2, and various sensors 61 to 63 measure the engine speed, atmospheric pressure, intake air amount, intake temperature, throttle opening, water temperature, etc.
After reading from etc., the process moves to step S3, and the fuel is injected! ) Calculate lflTΔ. Further, the process moves to step S4, where a correction fuel is calculated based on intake air temperature, water temperature, etc. with respect to the basic injection amount TA. That is, for example, when the engine is cold, the amount of fuel supplied is increased during cold operation, and as the engine warms up, the amount of fuel supplied is decreased.
Adjust with . When the engine reaches a predetermined warm-up state, the m-joint body 40 is stopped at a predetermined position to keep the fuel supply amount constant.

Next, in step S5, based on the basic injection 1JJITA and the corrected fuel, the 11-section body 4o in the fuel injection means 31 is moved up and down by a stepping morph or the like, and the volume of the metering chamber 36 is changed. Regulates the fuel stored. Also, based on the map, the fuel injection start time IITS is calculated. Roughly, in step S6, the compressed air injection timing and injection period 7 air are calculated.

ll1Il injection timing and injection tA period 7ai of this compressed air
As shown in FIG. 4, when the working chamber 3 is in the latter half of the intake stroke or the first half of the compression stroke, r injects and supplies a mixture of fuel and compressed air from the injection hole nozzle 15, and then supplies the mixture of fuel and compressed air to the working chamber 3. It is set so that only compressed air is injected and supplied from the injection nozzle 15 until the working chamber 3 on the trailing side in the rotor rotational direction passes the intake/exhaust overlap period.

After that, the process moves to step S7, and it is determined whether or not it is the injection time, and the process waits in this step S7 until the injection time comes, and when the injection time comes, the process moves to step S8, and both on-off valves 41 and 42 are opened as described above. At the same time, the air control valve 48
is opened, compressed air is supplied to the metering chamber 36, and fuel is injected into the working chamber 3 and returned.

In the above flow, in steps 86 to S8, the mixture of fuel and compressed air is injected from the injection nozzle 34 into fPF:
! ! A control means 80 for controlling the fuel injection means 31 so as to supply only compressed air to the working chamber 3 in the intake/exhaust overlap area from the injection nozzle 34 during the overlapping 571111 of the intake/exhaust stroke. It consists of

Therefore, in step S8, compressed air is supplied to the metering chamber 36 based on the gk#injection tJJ period.

That is, as shown in FIG. 5, the air control valve 48 opens at the injection start time TS, and after this period of movement, fuel and compressed air are injected into the working chamber 3 together. Then, weighing chamber 3
When the fuel in 6 is discharged, only compressed air is supplied to the working chamber 3, the supply period of this compressed air is extended to m nodes, and the air control valve 48 is closed at the injection end time TE.

In that case, as shown in FIG. 5 (a), when the working chamber 3 is in the latter half of the intake stroke or the first half of the compression stroke, the mixture of fuel and compressed air is injected into the working chamber 3 from the injection nozzle 34. Next, the same figure (b).

As shown in (C), only compressed air is injected from this injection nozzle 34, and this compressed air pushes the above-mentioned air-fuel mixture to the leading side in the rotor rotational direction, and the spark plug 1
A rich air-fuel mixture is formed near 0.10, and a lean air-air mixture is formed around it, so that the air-fuel mixture in the working chamber 3 is reliably stratified, and combustion is performed in a favorable manner as shown in FIG. .

Further, as shown in FIG. 5(b), only compressed air is injected from the injection nozzle 34 into the working chamber 1FJJ chamber 3 until the apex of the rotor 2 passes through the injection nozzle 34. The curtain prevents spitzback from occurring.

Furthermore, as shown in FIG. 5(C), during the overlap period of the intake and exhaust strokes, only compressed air is supplied from the injection nozzle 34 to the working chamber 3 in the overlap region of the intake and exhaust strokes. Exhaust boat 8 to intake boat 6
This prevents the flow of exhaust gas into the working chamber 3, thereby suppressing dilution gas from being carried into the working chamber 3, improving combustibility and reducing fuel consumption.

Furthermore, the dilution gas is prevented from being introduced into the working chamber 3 in the intake/exhaust overlap region by supplying compressed air from the injection nozzle 34 located on the leading side in the rotor rotational direction. Since compressed air is not supplied to the 02 sensor 62, the air-fuel ratio detection accuracy by the 02 sensor 62 is maintained at a good level, and the air-fuel ratio can be controlled with high accuracy.

In addition, since the fuel or compressed air is not injected and supplied until the working chamber 3 is in the latter half of the compression stroke, a low IIrJJ pressure of the injection nozzle 34 is sufficient. It will not stick to the surface.

Moreover, when injecting fuel, compressed air is mixed to
1, vaporization and atomization of the fuel are promoted, fuel is prevented from adhering to the spark plug, and combustibility is further improved.

(Effects of the Invention) As explained above, according to the scavenging device for a rotary piston engine of the present invention, a so-called two-fluid injection nozzle is disposed so as to directly face the working chamber, and fuel and compressed air are injected from the injection nozzle. In addition to supplying a mixture with air to the working chamber, only compressed air is supplied from the injection nozzle to the working chamber in the intake/exhaust overlap area during the fluctuation period of the intake/exhaust stroke. While maintaining good air-fuel ratio detection accuracy, it is possible to effectively suppress the introduction of illusory gas into the working chamber, and this combined with the ability to effectively stratify the air-fuel mixture in the working chamber improves fuel efficiency. It is possible to improve the

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show an embodiment of the present invention, and FIG. 1 is a general schematic diagram, FIG. 2 is a vertical side view of the metering unit, and FIG. 3 is a flowchart explaining the operation of the controller. , 4th
The figure is an explanatory diagram showing the injection timing and injection period of fuel and compressed air, and FIG. 5 is an explanatory diagram showing the generation of air-fuel mixture in the working chamber. 2... Rotor, 3... Working chamber, 16... Fuel supply system, 31... Fuel injection means, 33... Pressurizing means, 3
4... Injection nozzle, 36... Metering chamber, 37.
...Fuel inlet, 38...Fuel outlet, 39...Fuel discharge port, 40...Adjustment stop, 80...Control means. Figure 2 Figure 4 Figure 3 (C1) (b) 5 causes

Claims (1)

[Claims] (1) An injection nozzle provided to directly face the working chamber, a fuel metering chamber provided in the fuel supply system of the engine to store the required amount of fuel, and a fuel metering chamber provided in the metering chamber to introduce fuel into the chamber. a fuel inlet, a fuel outlet provided in the metering chamber to return excess fuel from the chamber to the fuel supply system, a regulating valve for changing the volume of the metering chamber, and an injector for injecting the fuel stored in the metering chamber. A fuel injection means comprising a fuel outlet for discharging fuel to a nozzle, and a pressurizing means for applying air pressure to discharge the fuel from the fuel outlet so that the fuel stored in the metering chamber is injected into the working chamber at a predetermined timing. In addition to supplying a mixture of fuel and compressed air from the injection nozzle to the working chamber, only compressed air is supplied from the injection nozzle to the working chamber in the overlap region of the intake and exhaust strokes during the overlap period of the intake and exhaust strokes. A scavenging device for a rotary piston engine, comprising a control means for controlling the fuel injection means to supply fuel.