JPH061055B2 - Intake device for rotary piston engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an intake device applied to a rotary piston engine having an auxiliary intake port in addition to a primary intake port, a secondary intake port, and a high output. The present invention relates to an intake device for a rotary piston engine, which is advantageous in terms of realization.

[Prior art]

A structure in which a rotary piston engine is provided with an auxiliary intake port in addition to a primary intake port and a secondary intake port is disclosed, for example, in Japanese Utility Model Laid-Open No. 58-146828.

In this conventional example, as shown in FIG. 3, a primary intake port 4 is provided in one of the side housings 3 on both sides of the combustion chamber 2 accommodating the rotary piston 1.
On the other hand, a secondary intake port 5 and an auxiliary intake port 6 are provided.

In this case, the primary intake port 4 is used for intake at low load,
The secondary intake port 5 is used for intake at medium load, and the auxiliary intake port 6 is used for high load.

By the way, the range in which these ports 4, 5, 6 can be opened to the combustion chamber 2 on the sliding contact surface of the side housing 3 with the rotary piston 1 is, as shown in FIG. It is limited between a sliding contact area D of an incorporated oil seal (not shown) and a sliding contact area E (partially shown) of a corner seal 7 mounted on a corner portion of the rotary piston 1.

Further, when the two kinds of intake ports 5 and 6 are opened in the same side housing 3 as described above, if the opening and closing timings of them are not properly set, as shown in FIG. The secondary intake port 5 is opened before the valve is closed, and a gap 8 between these ports 5 and 6 and the rotary piston 1 and the side housing 3 is provided so that the air-fuel mixture during the compression stroke is indicated by an arrow L. Then, the rotary piston 1 blows off toward the suction stroke side. Therefore, it is meaningless to set the position of the opening edge 5a on the left side in FIG. 4 that sets the opening start timing of the secondary intake port 5 to the left side of the range where the above-mentioned blow-through does not occur.

The position of the opening edge 5b on the lower side (upper side in FIG. 4) of the rotary piston 1 of the secondary intake port 5 in the rotational direction is limited by the closing timing of the secondary intake port 5.

After all, in such a conventional device, the opening area of the secondary intake port 5 cannot be increased beyond a certain size, and a large limitation is imposed on achieving high output.

[Object of the Invention]

The present invention has been made in consideration of the above problems, and it is possible to eliminate blow-by of the air-fuel mixture during the compression stroke to the suction stroke side, which is advantageous in achieving high output, and the primary An object of the present invention is to provide an intake device for a rotary piston engine that can improve the stability of combustion under a load condition in which the intake port is used, for example, a low load.

[Structure of Invention]

The intake device of the rotary piston engine according to the present invention,
The primary intake port and the auxiliary intake port are provided in the same side housing, and the opening start timing of the primary intake port is set after the auxiliary intake port is closed to set the leak passage of the air-fuel mixture from the compression stroke side to the intake stroke side. On the other hand, the secondary intake port is provided in the other side housing, and the opening start timing of this secondary intake port is set earlier than the opening start timing of the primary intake port, so that the desired output can be obtained. The opening area of the secondary intake port is secured, and the overlap between the opening of the primary intake port and the opening of the exhaust port is made smaller than the overlap between the opening of the secondary intake port and the opening of the exhaust port. It is a thing.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

The rotary piston engine 10 shown here includes one rotary piston 11 and a housing 12 that houses the rotary piston 11.
And have.

The housing 12 includes a rotor housing 13 and a pair of side housings 14, 1 connected to both sides of the rotor housing 13.
5 has a cocoon-shaped combustion chamber 16 formed therein.

An intake device 17 for supplying intake air to the combustion chamber 16 includes an air cleaner (not shown), a carburetor (not shown),
Three intake systems 18, 19, 20 connected to this, that is, a primary intake system 18 that supplies intake air at low load,
A secondary intake system 19 that supplies intake air when the load is medium, and a supercharged intake system 20 that supplies intake air when the load is high.

On one side housing 14, a primary intake port 21 of a primary intake system 18 and an auxiliary intake port 22 of a supercharged intake system 20 are provided.
And the other side housing 15 is provided with the secondary intake port 23 of the secondary intake system 19.

The opening edge 21a on the left outside of the primary intake port 21 is
When the opening edge 22a on the upper right side of the auxiliary intake port 22 and the upper right flank 11a of the rotary piston 11 overlap (when the rotary piston 11 is located at the position shown in FIG. 2A), the left side of the rotary piston 11 It is located at the position of the flank 11b (or to the right of it).

The position of the opening edge 21b on the upper side of the primary intake port 21 is selected corresponding to the closing timing of the port 21, and when this opening edge 21b overlaps with the upper right flank 11a of the rotary piston 11 (see FIG. 2). When the rotary piston 11 is located at the position C), the lower opening edge 22b of the auxiliary intake port 22 is set to a position higher than the flank 11a.

The left outer opening edge portion 23a of the secondary intake port 23 is located on the left side of the left outer opening edge portion 21a of the primary intake port 21.

Further, the opening edge portion 23b on the upper side of the secondary intake port 23
Is positioned at a height equal to or lower than the upper opening edge 21b of the primary intake port 21.

In the above structure, the closing timing of the auxiliary port 22 is determined by the position of the opening edge 22a on the upper right side of the port 22. That is, the auxiliary intake port 22 is closed when the upper right flank 11b of the rotary piston 11 crosses the opening edge 22a from the bottom to the top (when the rotary piston 11 is located at the position shown in FIG. 2A). After the auxiliary intake port 22 is closed, the compression stroke is performed in the upper right portion of the rotary piston 11 in the combustion chamber 16.

On the other hand, the opening start timing of the primary intake port 21 is determined by the position of the opening edge 21a on the left outside of the port 21. That is, opening of the primary intake port 21 is started when the left flank 11a of the rotary piston 11 crosses the opening edge 21a from left to right (when the rotary piston 11 is located at the position shown in FIG. 2B). .
When opening of the intake port 21 is started, an intake stroke is performed on the left side of the rotary piston 11 in the combustion chamber 16.

The opening edge 21a on the left outside of the primary intake port 21 is
Since the auxiliary intake port 22 is located at the position of the left flank 11b of the rotary piston 11 (or the right side thereof) in the position of FIG. 2A where the auxiliary intake port 21 is closed, the primary intake port 21 is 22 will be opened after being closed, and these intake ports 2
1, 22 are never opened at the same time.

As a result, there is no possibility of forming a leak passage communicating from the compression stroke side of the combustion chamber 16 to the suction stroke side via these ports 21 and 22, and blowback does not occur, so that a desired output can be obtained. It will be possible.

The secondary intake port 23 is a side housing 1 different from the side housing 14 in which the auxiliary intake port 22 is provided.
5, it is free from the problem of blow-by through the auxiliary intake port 22. Therefore, it becomes possible to start the opening of the secondary intake port 23 before the auxiliary intake port 22 is closed so that the combustion chamber 16 can inhale the amount of intake air required to obtain a desired output. Will be able to bring out the high output of.

That is, the opening start timing of the secondary intake port 23 is determined by the position of the opening edge portion 23a on the left outside of this port 23,
By locating the opening edge portion 23a on the left side of the left outer opening edge portion 21a of the primary intake port 21,
The opening start timing of the secondary intake port 23 is set to the primary intake port 2
It is possible to secure the opening area and opening time of the secondary intake port 23 sufficient to inhale the intake amount required at the time of medium load by making it faster than that of 1, and to obtain a desired output.

Further, the opening edge portion 21 on the left outside of the primary intake port 21 is provided.
a is an opening edge portion 23a on the left outer side of the secondary intake port 23.
By arranging the intake port 21 on the right side, the overlap between the opening of the intake port 21 at low load and the opening of the exhaust port (not shown) can be compared to the overlap between opening of the intake port 23 at medium load and opening of the exhaust port. It is also possible to improve the stability of combustion at low load by reducing the amount of the fuel.

As described above, the rotary piston engine intake device according to the present invention is provided with the primary intake port 6 and the auxiliary intake port in the same side housing, and the opening start timing of the primary intake port is set to the auxiliary intake port. By setting after the port is closed, it is possible to eliminate the formation of the leak passage of the air-fuel mixture which is communicated from the compression stroke side to the suction stroke side through the two kinds of intake ports provided in the same side housing. It is possible to surely avoid the stairwell through the port.

As a result, it is possible to remove the limitation on the output increase due to such blow-by.

In addition, these two types of ports are provided in one side housing, and the other side housing is provided with the above-mentioned secondary intake port that is another type of intake port, so that this third port can be used for this and other two ports. It is possible to open the opening area of this port to a desired size by eliminating the problem of occurrence of blow-through through one of the ports, which is advantageous in achieving high output.

Further, for example, by setting the opening start time of the secondary intake port used at the time of medium load earlier than the opening start time of the primary intake port used at the time of low load, the opening of the primary intake port and the opening of the exhaust port can be performed. Can be made smaller than the overlap between the opening of the secondary intake port and the opening of the exhaust port, and the stability of combustion under a load condition using the primary intake port, for example, low load can be enhanced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a schematic view showing the relationship between the arrangement of primary, secondary and auxiliary intake ports and the rotary piston, and FIG. 3 is a sectional view of a conventional example. Figure,
FIG. 4 is a schematic diagram showing a range in which each intake port can be arranged,
FIG. 5 is a sectional view of a main part of a conventional example showing the principle of occurrence of blow-by. 10 is a rotary piston engine, 14 is a side housing, 15 is a side housing, 21 is a primary intake port, 22 is an auxiliary intake port, and 23 is a secondary intake port.

Claims (1)

[Claims] 1. A rotary piston engine having an auxiliary intake port in addition to a primary intake port and a secondary intake port, wherein the primary intake port and the auxiliary intake port are provided in the same side housing. While setting the opening start time of the after the closing of the auxiliary intake port,
An intake device for a rotary piston engine, wherein the secondary intake port is provided in another side housing, and an opening start timing of the secondary intake port is set earlier than an opening start timing of the primary intake port.