JPH079183B2 - Engine intake system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of an intake system for an engine, which utilizes the dynamic effect of intake air to improve output.

(Prior Art) Conventionally, as an air intake device of an engine, for example, Japanese Patent Laid-Open No. 59-708
As disclosed in Japanese Patent No. 33, 33, the independent intake passages of each cylinder of a two-cylinder rotary piston engine are communicated with each other through a communicating portion downstream of a throttle valve, and By properly setting the passage length between the intake ports, the closing compression wave and the opening compression wave generated in the independent intake passage when the intake port of one cylinder is closed and opened are connected to the other through the communicating portion. It is known that supercharging is performed by propagating to an intake port immediately before the cylinder is fully closed to obtain a dynamic effect due to intake interference between the cylinders.

(Problems to be Solved by the Invention) However, in the above-described conventional one, since the passage length between the intake ports of both cylinders formed by the communication portion and the independent intake passages downstream thereof is constant, dynamic The effect can be obtained only in a specific rotation range depending on the passage length.

Therefore, a control valve that collects each of the independent intake passages upstream of the throttle valve and communicates with the communication portion downstream of the throttle valve and that opens at high engine speed is provided at the communication portion, and the control valve is closed at low engine speed. The length of the passage between the intake ports of both cylinders is made long by the collecting portion and the independent intake passage downstream thereof, while the control valve is opened at the time of high engine speed to connect between the intake ports of both cylinders. It is conceivable to make the passage length short so as to be formed by the communication portion and the independent intake passage downstream thereof so that the dynamic effect can be effectively obtained in the entire engine rotation range.

However, in this case, since a communication part is provided between the independent intake passages and a control valve is arranged in the communication part, the intake device becomes complicated and a large space is occupied by the intake device. ing.

The present invention has been made in view of the above points, and an object of the present invention is to suppress the height of an intake device and make it compact by appropriately laying out the independent intake passage and the control valve. It is in.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the solution means of the present invention is such that after extending the upstream end of the independent intake passage of each cylinder group in substantially the same direction in the same plane, Bend them so that they face each other. A control valve that opens and closes the communication between the independent intake passages is provided at the confluent portion, and the rotation axis of the control valve is arranged in the plane.

(Operation) With the above configuration, in the present invention, the passage length between the intake ports of the cylinder group is changed by opening and closing the communication between the independent intake passages according to the engine speed by the control valve. Good dynamic effect is obtained in all rotation range.

In this case, since each of the independent intake passages is in the same plane and the rotary shaft that is the long member of the control valve is in the same plane, the height of the intake device is suppressed and the size is made compact.

(Example) Hereinafter, the Example of this invention is described based on drawing.

1 to 3 show an embodiment in which the present invention is applied to a two-cylinder rotary piston engine. This engine has a centrally located intermediate housing 1
And front and rear rotor housings 2a, 2b arranged on both sides of the intermediate housing 1 and having trochoidal inner peripheral surfaces, and front and rear side housings arranged before and after each rotor housing 2a, 2b. 3
a and 3b, and two cylinders C, C are formed inside thereof by these housings. A polygonal rotor 4 is arranged in each cylinder C, each rotor 4 is supported by an eccentric shaft 5, and each rotor 4 makes a planetary rotational motion to form a partition in each cylinder C. The three working chambers 6, 6, 6 to be operated are made to sequentially perform the intake, compression, explosion, expansion and exhaust strokes.

The intermediate housing 1 has primary ports 7 and 7 for supplying fresh air to the working chambers 6 of the cylinders C in the entire operating range. Further, a secondary main port 8 for supplying fresh air to the working chamber 6 of each cylinder C only when the engine is under high load is provided on the leading side in the rotor rotation direction with respect to the primary port 7 of each of the side housings 3a, 3b. Further, a secondary auxiliary port 9 for supplying fresh air to the working chamber 6 of each cylinder C at the time of high rotation and high load of the engine is opened on the leading side in the rotor rotation direction with respect to each secondary main port 8. .

Further, one end of the first independent intake passage 10 is connected to each primary port 7, and the other end (upstream end) of each first independent intake passage 10 has a dynamic effect due to pressure propagation between the cylinders. They are arranged so as to face each other and are communicated with each other by the first merging portion 11. Further, one end of the second independent intake passage 12 is connected to each of the secondary main port 8 and the secondary auxiliary port 9, and the other end (upstream end) of each of the second independent intake passages 12 is connected between the cylinders. They are arranged opposite to each other so as to obtain a dynamic effect by pressure propagation, and are communicated with each other by the second merging portion 13. The second independent intake passages 12 are arranged outside the first independent intake passages 10 as shown in FIGS. 2 and 3. Then, the upstream ends of the independent intake passages 10 and 12 are bent upward on the side of the housing of the engine, inverted, and then extend in a direction substantially intersecting with the eccentric shaft 5 within a substantially horizontal plane P. , First
The independent intake passages 10, 10 are first independent intake passages, and the second independent intake passages 12, 12 are joined so as to be curved so as to face each other in the eccentric shaft direction.

A valve 14 for opening and closing the communication of the second independent intake passage 12 to the secondary auxiliary port 9 is provided at one end of the second independent intake passage 12, and the valve 14 uses an intake negative pressure as an operation source. It is driven by a diaphragm type actuator 15, and the actuator 15 is controlled by a controller 16. The controller 16 is provided with the above independent intake passages.
The opening degree of the throttle valves 17a to 17c provided in 10, 12,
The signal from the air flow sensor 18 and the engine speed signal are input, and the valve is operated when the engine is running at high speed and high load.
While opening the valve 14, the valve 14 is controlled to be closed in other operating ranges.

The first merging section 11 and the second merging section 13 are provided with a first control valve 19 and a second control valve 20 for opening and closing the communication between the respective merging sections 11 and 13. The first control valve 19 and the second control valve
Both 20 are cylindrical rotary valves, and both control valves 19,2
The valve body of No. 0 has a common rotary shaft 27, and the rotary shaft 27 is arranged so as to be orthogonal to the eccentric shaft 5 in the plane P, and a diaphragm type actuator using an intake negative pressure as an operation source. It is driven in conjunction with 21. The actuator 21 is controlled by the controller 16 so that the first and second control valves 1
While opening 9,20, both control valves 19,20
Is controlled to close.

Further, one ends of the first upstream intake passages 22 and 22 are connected near both sides of the first control valve 19, respectively, and the other ends of the first upstream intake passages 22 and 22 are collected and connected to the air cleaner 23. There is. In addition, the second control valve 20 has a second
One end of each of the upstream intake passages 24, 24 is connected to
The other ends of the upstream intake passages 24, 24 are collected and connected to the air cleaner 23 in the same manner as the first upstream intake passages 22, 22. The first upstream intake passages 22 are arranged outside the second upstream intake passages 24 as shown in FIGS. 2 and 3. The downstream ends of the upstream air passages 22 and 24 are connected to the lower sides of the independent intake passages 10 and 12, respectively, and the upstream ends of the upstream air passages 22 and 24 are located above the housing of the engine.
After extending in the extending direction of 10, 12, it bends upward and turns over to face the air cleaner 23. In addition, 25 is each intake passage 10,1
2 injectors, 26 are rotor housings 2
It is a spark plug arranged in a and 2b.

Therefore, in the above embodiment, when the engine is running at low speed, the first and second control valves 19 and 20 are closed and both cylinders C and C are closed.
The length of the passage between the primary ports of the first independent intake passage 10
And a long one formed by the first upstream intake passage 22 and a long passage between the secondary main ports of both cylinders C, C formed by the second independent intake passage 12 and the second upstream intake passage 24. Therefore, it is possible to favorably obtain the low-frequency dynamic effect matching the engine speed.

In addition, since the first and second control valves 19 and 20 are cylindrical rotary valves, the dead formed between the valve body and the openings of the merging portions 11 and 13 to the independent intake passages 10 and 12. The volume is reduced, the compression wave propagating in the intake passage can be suppressed from being attenuated, and the dynamic effect can be effectively obtained.

On the other hand, when the engine speed is high and the load is high, the first and second control valves 19 and 20 are opened, and the passage length between the primary ports of both cylinders C and C is determined by the first independent intake passage 10 and the first merging portion 11. And the length of the passage between the secondary main ports of both cylinders C and C becomes shorter than that of the second independent intake passage and the second
Since it is a short one formed by the confluence portion 13, it is possible to favorably obtain a high frequency dynamic effect matching the engine speed.

Moreover, the first independent intake passages 10, 10 and the second independent intake passage 1
Since 2 and 12 are arranged facing each other and are communicated with each other by the merging portions 11 and 13, the passage resistance in the vicinity of the merging portion becomes small, and the dynamic effect can be further enhanced.

In this case, the first independent intake passages 10, 10 and the second independent intake passages 12, 12 are in the same horizontal plane P, and the rotary shaft 27 which is a long member of the first control valve 19 and the second control valve 20. Is in the plane P, the height of the intake device is suppressed above the engine, and the size of the intake device can be reduced.

Moreover, the first upstream intake passages 22 and 22 and the second upstream intake passages 2
Since the valves 4, 24 are arranged in the space between the first independent intake passages 10, 10 and the second independent intake passages 12, 12 and the engine, the intake system can be made more compact.

(Effects of the Invention) As described above, according to the engine intake system of the present invention, the upstream ends of the independent intake passages of the respective cylinder groups are extended in substantially the same direction in the same plane and then face each other. In addition to bending and merging, the rotation axis of the control valve provided in this merging portion is arranged in the above plane, so that the passage length between the intake ports of the cylinder group is changed to achieve efficient pressure in the entire rotation range of the engine. While obtaining a good dynamic effect by propagation,
The height of the intake device is suppressed, and the intake device can be made compact.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is an overall schematic configuration diagram, FIG. 2 is a side view of an engine, and FIG. 3 is a plan view of the engine. 10 ... 1st independent intake passage, 11 ... 1st confluence part, 12 ... 2nd independent intake passage, 13 ... 2nd confluence part, 19 ... 1st control valve, 20 ... 2nd control valve, 27 …… Rotary axis, C …… Cylinder, P
……Plane.

Claims (1)

[Claims] 1. An independent intake passage of each cylinder group has an upstream end extending in substantially the same direction in the same plane, and then curved and joined so as to face each other. A control valve is provided to open and close the communication between the passages.
An intake system for an engine, wherein a rotary shaft of the control valve is arranged in the plane.