JPS6147968B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake system for a rotary piston engine, and particularly to an improvement in a supercharging system that improves charging efficiency by supplying pressurized air in addition to air-fuel mixture.

Generally, the technical concept of increasing the charging efficiency and improving the output performance of the engine by pressurizing and inhaling all of the intake air during the intake stroke of the engine using a supercharger is well known. However, in this case, all of the intake air drawn into the engine passes through the supercharger, which creates ventilation resistance in the supercharger itself, resulting in a decrease in charging efficiency and a decrease in output performance. On the other hand, all of the intake air taken into the engine is adiabatically compressed by the supercharger and heated to a high temperature, which lowers the density of the intake air and prevents sufficient improvement in charging efficiency. In order to avoid this problem, the supercharger must be made larger. Therefore, conventionally, in addition to the main intake port that sucks the air-fuel mixture using the engine's intake negative pressure, a supercharging port that supplies air or air-fuel mixture pressurized by the turbocharger has been installed, allowing natural intake due to the negative pressure and the turbocharger. A system has been proposed in which air is taken in by supercharging, and the charging efficiency is effectively improved over the entire rotation range of the engine using a relatively small-capacity supercharger. However, in the conventionally proposed devices, at least one of the main intake port and the supercharging port is a so-called peripheral port, and an effective supercharging effect is not necessarily obtained. That is, in the conventional type, when the apex seal attached to the top of the rotor passes over the port, the preceding working chamber and the succeeding working chamber communicate with each other, and blowback from the preceding working chamber to the succeeding working chamber is prevented. Therefore, in order to obtain the desired supercharging effect, it is necessary to increase the capacity of the supercharger accordingly, and if the opening position is shifted to the trailing side, the overlap with the exhaust port will increase. There is a problem in that the stability of combustion during light loads is impaired, and the main intake port and supercharging port close early, which impedes the suction capacity of the main intake port and prevents a sufficient supercharging effect from being obtained. .

Therefore, in the present invention, the main intake port and the supercharging port are placed close to each other in the side housing to eliminate overlap with the exhaust port without impeding the suction capacity of the main intake port.
The outer periphery of the supercharging port is set so that it opens almost simultaneously with the main intake port, while the pressure inside the intake working chamber and the pressure of the pressurized air are almost the same after the main intake port is fully closed. setting its upper edge to be delayed closed by the rotor in a rotational position;
We decided to secure a sufficient area for the supercharging port without causing blowback, and as a result, we were able to obtain sufficient supercharging effect even with a small-capacity supercharger without compromising combustion stability at light loads. The basic feature is that

The present invention will be specifically described below with reference to the illustrated embodiments.

In Fig. 1, 1 is a trochoidal inner peripheral surface 2.
A casing formed of a rotor housing 2 having a diameter of 1 and side housings 3 disposed on both sides of the rotor housing 2; 4 a triangular rotor that rotates planetarily within the casing 1 while sliding its top portion on the trochoid inner circumferential surface 2a; 5; are the inner surface of casing 1 and rotor 4
a variable volume working chamber defined by a flank surface of the
6 is a main intake port that opens on the inner surface of the side housing 3 and is opened and closed by the rotor 4 at a predetermined timing with respect to the intake working chamber 5a during the intake stroke;
7 is an air cleaner, 8 is a carburetor, 9 is an intake passage that supplies the air-fuel mixture generated by the carburetor 8 to the main intake port 6, and 10 is an air-fuel mixture in the compression working chamber 5b near the compression top dead center. Spark plug, 1
Reference numeral 1 denotes an exhaust port that discharges exhaust gas from the exhaust working chamber 5c to the exhaust manifold 12, which continuously performs intake, compression, explosion, and
It constitutes a rotary piston engine that repeats the expansion and exhaust strokes.

On the other hand, 13 is a supercharging port that opens on the inner surface of the side housing 3 similarly to the main intake port 6, and is opened on the leading side of the main intake port 6 with respect to the rotational direction of the rotor 4, and supplies pressurized air to the working chamber 5. It is configured to be supplied almost in the axial direction.
14 is a vane type air pump as a supercharger driven by the engine; 15 is air pump 1;
A pressurized air passage 16 is interposed in the pressurized air passage 15 and communicates the discharge side of 4 with the supercharging port 13 and supplies pressurized air discharged by the air pump 14 to the supercharging port 13. A normally open opening/closing valve completely closes the pressurized air passage 15 to cut off the supply of pressurized air during light load operation of the engine, and a normally open opening/closing valve 17 controls high pressure when the discharge side pressure of the air pump 14 reaches a set value or higher. These pressure valves discharge to the atmosphere, and constitute a supercharging device that supplies pressurized air to the intake stroke working chamber 5a in addition to the air-fuel mixture taken in from the main intake port 6.

Next, the setting of the supercharging port 13 will be explained. First, the outer peripheral edge 13a of the supercharging port 13 is connected to the main intake port 6 at the rotor rotational position where the exhaust port 11 provided in the rotor housing 2 is closed. In order to open into the intake stroke working chamber 5a at almost the same time, the outer peripheral edge 6a of the main intake port 6 is set on a curve extending along the flank edge of the rotor posture A just before the start of the intake stroke shown by the dashed line in the figure. do.
In other words, since the outer circumferential edge 6a of the main intake port 6 and the outer circumferential edge of the supercharging port 13 are both determined by the overlap with the exhaust port 11, the timing at which the supercharging port 13 begins to open overlaps. It is necessary to set the time when the main intake port 6 starts to open in order to secure the necessary area without any problem.

Further, the trailing side lower edge 13b of the supercharging port 13 is set substantially parallel to the leading side upper edge 6b of the main intake port 6 at a small distance from the leading side upper edge 6b. The main intake port 6 is started to close immediately from the rotor posture RO (position indicated by the chain double-dashed line in the figure) immediately after the main intake port 6 is fully closed.

Further, the upper edge 13c of the leading side of the supercharging port 13 faces the lower edge 13b at a required distance in parallel with the lower edge 13b, and as the rotor 4 further rotates from the rotor posture B, the main intake port 6 It is set so that it is fully closed after rotating through a predetermined angle, for example, 30° to 50° at an eccentric shaft angle.

In this case, the timing of fully closing the supercharging port 13 is set to be as late as possible within a range that does not cause blowback to the supercharging port 13. Therefore, immediately before the air pressure applied to the supercharging port 13 becomes equal to the internal pressure of the compression working chamber 5b, which increases as the main intake port 6 moves to the compression stroke after the main intake port 6 is fully closed, the supercharging port 13 closes completely. It is set so that

Note that, like the inner peripheral edge 6c of the main intake port 6, the inner edge 13d of the supercharging port 13 is set to be located outside the sliding locus of the oil seal.

Therefore, when the rotor 4 further rotates slightly from the rotor posture A, the main intake port 6 and the supercharging port 13 are opened by the rotor 4 to the intake working chamber 5a, and the main intake port 6 is connected to the carburetor 8. The air-fuel mixture thus supplied is sucked into the working chamber 5a by the negative pressure in the working chamber 5a, while pressurized air pressurized by the air pump 14 is sent from the supercharging port 13 to the working chamber 5a. supplied within. When the rotor 4 further rotates from this state, the pressure in the intake working chamber 5a increases, the amount of air-fuel mixture sucked from the main intake port 6 gradually decreases, and when the rotor position B is reached, the main intake port 6 Since the air-fuel mixture suction capacity from the rotor position B becomes zero, the main intake port 6 is closed in this rotor attitude B.

In this case, if the main intake port 6 is set to open until after the suction capacity is exceeded, the supercharging port 13
This is not preferable because the supercharged air from the main intake port 6 and the intake passage 9 will flow back into the main intake port 6 and the intake passage 9.

From the rotor attitude described above until the supercharging port 13 closes, pressurized air pressurized by the air pump 14 is supplied to the working chamber 5a from the supercharging port 13 having a necessary and sufficient opening area.

Therefore, by sufficient intake of the air-fuel mixture through the main intake port 6 and sufficient supercharging through the supercharging port 13, the filling efficiency of the engine can be improved and the output performance can be reliably improved.

Further, since the supercharging port 13 opens toward the axial direction of the working chamber 5a on the trailing side of the intake working chamber 5a that moves to the compression stroke after the main intake port 6 is fully closed, and supplies pressurized air, Supercharging port 13
The pressurized air supplied from the intake working chamber 5a does not dilute the air-fuel mixture on the leading side of the working chamber 5a.
The fuel mixture is reliably filled into the railing side of the fuel tank a, and acts to push the already supplied air-fuel mixture to the leading side, thereby improving the combustibility of the engine.

In the above embodiment, the discharge side of the air pump 14 and the supercharging port 13 are directly communicated through the pressurized air passage 15, but if a surging tank is interposed in the middle, the vane type pump can be easily connected. Pulsation, which is a drawback, can be effectively alleviated, and pressure loss due to pulsation can be prevented.

As is clear from the above description, the present invention provides a main intake port and a supercharging port in close proximity to each other in a side housing, and opens the supercharging port almost at the same time as the main intake port. On the other hand, the closing timing is set so that the rotor closes at a rotational position of the rotor where the pressure in the intake working chamber and the pressure of the pressurized air are almost the same pressure, and the pressurized air is supplied from the supercharging port to the working chamber. To provide an intake device for a rotary piston engine, which supplies air to a supercharging port in a transition period from an intake stroke to a compression stroke within a range that does not cause blowback.

Therefore, in the intake system for a rotary piston engine according to the present invention, it is possible to eliminate overlap with the exhaust port without impeding the suction capacity of the main intake port, and at the same time, it is possible to eliminate overlapping with the exhaust port without impeding the suction capacity of the main intake port. Enough area for the charging port can be secured, and as a result, the supercharging efficiency can be improved even with a small-capacity supercharger without compromising the stability of combustion under light loads, thereby improving engine charging efficiency. This makes it possible to improve output performance.

Furthermore, in the intake system of the rotary piston engine of the present invention, since the main intake port and the supercharging port are provided close to each other in the same side housing, the intake passage and the pressurized air passage are necessarily close to each other. , the high temperature pressurized air flowing through the pressurized air passage and the air-fuel mixture flowing through the intake passage exchange heat,
Atomization of the fuel in the air-fuel mixture is promoted, improving combustibility, and the temperature distribution of the intake air in the intake working chamber is also made uniform, making it possible to prevent knocking.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional explanatory diagram showing an intake device of a rotary piston engine according to an embodiment of the present invention;
FIG. 2 is a diaphragm showing the opening/closing timing of the main intake port and supercharging port in the above embodiment. 1... Casing (2... Rotor housing,
3... side housing), 4... rotor, 6...
... Main intake port, 9 ... Intake passage, 13 ... Supercharging port, 14 ... Air supply pump, 15 ... Pressurized air passage.

Claims (1)

[Scope of Claims] 1. A rotary piston engine in which a polygonal rotor rotates planetarily in a casing composed of a rotor housing having a trochoidal inner surface and side housings located on both sides of the rotor housing. The main intake port and the supercharging port are provided close to each other, and the supercharging port is opened almost simultaneously with the main intake port at the rotor rotational position where the exhaust port is closed, and the main intake port is closed during high load operation. The rotor is configured to close at a rotational position of the rotor where the pressure inside the intake working chamber and the pressure of the supercharging air are almost the same pressure. An intake device for a rotary piston engine, characterized in that pressurized air is supplied from a rotary piston engine.