JPH02115528A - Fuel injection system of rotary piston engine - Google Patents

Abstract

PURPOSE:To secure combustion improvement through stratification by installing a fuel injection port in a side housing, and having the fuel injection port opened in the direction of trailing and facing toward a rotary recess. CONSTITUTION:Rotors 4, 5 rotate, and suction, compression, explosion and exhaust are performed in operating chambers 9, 10 which are partitioned with each rotor housing 2, 3 and side housing 6-8. In the side housings 6, 8, one each of fuel injection ports 11, 12 are installed on the leading side of the operating chambers 9, 10 when the rotors 4, 5 are at their bottom dead points. These fuel injection ports 11, 12 are faced toward the direction of trailing and the direction of rotary recess 13. Dense layers of air-fuel mixture are formed in the rotary recess this way to secure combustion improvement.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel injection device for a rotary piston engine that stratifies an air-fuel mixture by directly injecting fuel into a working chamber.

(Prior Art) Conventionally, as described in, for example, Japanese Unexamined Patent Publication No. 52-36207, a piston recess (rotary recess) is provided in the case outer cylinder portion (rotor housing) of a rotary piston engine in the leading direction of the working chamber. A fuel injection port is provided that opens toward the piston, and fuel is injected from the fuel injection port toward the piston recess at a predetermined timing, thereby creating an ignitable air-fuel mixture within the piston recess when the spark plug is located. It is known that the structure is made to form a .

However, with such conventional fuel injection devices, fuel is injected from the peripheral side toward the rotary recess, so
There is a problem that the fuel is mixed and cannot be collected compactly in the rotary recess. Furthermore, as the rotor rotates, a flow of intake air toward the leading side occurs in the working chamber, so if fuel is injected toward the leading side, there is a problem in that the flow of intake air causes the fuel to be concentrated on the leading side.

(Object of the Invention) The present invention has been made in view of the above problems, and is a fuel injection device for a rotary piston engine that can reliably unevenly distribute fuel within a rotary recess and reliably improve combustion through stratification. The purpose is to obtain.

(Structure of the Invention) The present invention provides a rotary piston engine that directly injects fuel into a working chamber, in which a fuel injection port is provided in a side housing, and the fuel injection port is opened in a trailing direction and toward a rotary recess. Achieved the purpose.

(Function) Fuel is injected from the fuel injection port of the side housing in the trailing direction toward the rotary recess at a predetermined timing, so that it advances against the flow of intake air in the working chamber and collects in the rotary recess.

As a result, a rich mixture layer is formed within the rotary recess.

(Example) Examples will be described below based on the drawings.

FIG. 1 is an overall view of one embodiment of the present invention, and FIG. 2 is a detailed view of the structure of the fuel injection valve installation.

The rotary piston engine I of this embodiment is of a 20-cylinder type, and rotors 4 and 5 rotate along the inner peripheral surface within each rotor housing 2.3.
．． Suction, compression, explosion, and exhaust are carried out in each working chamber 9° IO, which is partitioned by 3 and a side housing 6° 7.8.

The side housings 6.8 located on both sides contain working chambers 9 when the rotors 4, 5 are at the BDC (bottom dead center) position.
．． Fuel injection port II, located on the leading side of 10,
2 are provided respectively.

These fuel injection ports 11.12 are arranged in the rotary recess 1 in the trailing direction and when the rotor 4.5 is in the above position.
It is oriented in the direction of 3.

The side housing 6.8 on both sides has the fuel injection port I.
A socket 14 is attached to the back space of 1.12 from above. These sockets 14 are formed with fuel outlet passages 15 that extend obliquely laterally from the center and communicate with the fuel injection ports It, 12. A fuel injection valve 16 is installed in the upper part of this socket 14. Further, an annular groove 17 is provided on the outer periphery of the socket I4, and a plurality of air injection ports 18 that open around the injection port of the fuel injection valve 16 are formed at the bottom of the annular groove 17.

The side housing 68 has the annular groove 1 of the socket I4.
An air assist passage 19 is formed which communicates with the air assist passage (7), and a check valve 20 is provided in the air assist passage (7). In addition, for the socket 14 on the right side in FIG. 2, an air assist passage is formed toward the back of the figure, and a check valve is also provided. Assist air for atomizing the fuel is supplied to the air assist passage 19 via an air vibrator connected to the nipple 21 .

The check valve 20 is provided to eliminate compression loss due to intake air blowing back upstream of the assist air passage during the compression stroke.

As shown in FIG. 2, the fuel injection valve I6 is of the poppet valve type, thereby ensuring gas attack resistance and effectively providing air assist to promote atomization of the fuel.

The fuel injector 16 is mounted in the side housing 6.8 via the socket I4 as described above and communicates with the fuel injection port 11.12 of the site housing 6.8 via the obliquely formed fuel outlet passage 15. Because of this structure, the fuel injection valve 16 can be disposed compactly without protruding on the front and rear sides of the engine, where there is little room for layout. In addition, the fuel injection valve 16 itself can be placed outside the side housing 6.8 so as not to be heated as much as possible, thereby preventing the occurrence of percolation.

The timing of fuel injection is determined by the rotor posture in which fuel can be injected after the leading side of the rotary recess 13 has been raised, and the timing in which fuel can be injected based on the relationship between the fuel pressure and the atmospheric pressure in the working chamber 9. It's coming. In this embodiment, the timing of fuel injection (injection pulse) is set around BDC for each working chamber, as shown in the time chart of FIG. The timing at which fuel is actually injected is around 30'' after BDC because there is a delay of about 30 degrees in eccentric shaft angle from when the injection pulse is output until the fuel is actually injected.

Note that this time chart shows 10 minutes, and 2 minutes.
In the case of the 0-star, the same operation is performed for the 10-star with a phase difference of 180° eccentric shaft angle.

FIG. 4 is a flowchart for executing fuel injection in this embodiment. When started, first, the rotation period is measured by looking at the eccentric shaft angle, and then the output of the air flow meter is detected.

Next, calculate the engine speed from the rotation period of the eccentric shaft angle, and calculate the fuel injection rate during the injection pulse by multiplying the intake air amount, which is the output value of the air-to-meter, divided by the engine speed by a constant. do.

Next, it is determined whether or not it is the predetermined injection timing, taking into account the injection delay. Then, when it is determined that it is the injection timing, the injection is executed.

(Effects of the Invention) Since the present invention is configured as described above, the fuel can be injected in opposition to the flow of intake air in the working chamber, and the fuel can be reliably unevenly distributed within the rotary recess.

Therefore, reliable stratified combustion can be performed.

[Brief explanation of the drawing]

Fig. 1 is an overall view of one embodiment of the present invention, Fig. 2 is a detailed view of the structure of the fuel injection valve installation in the same embodiment, Fig. 3 is a time chart showing the characteristics of the embodiment, and Fig. 4 is a flowchart for executing control in the same embodiment. I; Rotary piston engine, 2, 3: Rotor housing, 4.5: Rotary recess, 678, Side housing, 9.10: Working chamber, It. 12: Fuel injection port, 13. Rotary recess, 16 fuel injection valves.

Claims (1)

[Claims] (1) In a rotary piston engine that injects fuel directly into the working chamber when the rotor position is near the intake bottom dead center, a fuel injection port is provided in the side housing, and the fuel injection port is directed in the trailing direction and toward the rotary recess. A fuel injection device for a rotary piston engine characterized by having an open opening.