JPH079182B2 - 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 intake passages of each cylinder of a two-cylinder rotary piston engine are communicated with each other at a communication portion downstream of the throttle valve, and the intake ports of both cylinders are formed by the communication portion and the intake passages downstream thereof. The passage length between the cylinders is set appropriately, and the closing compression wave and the opening compression wave generated in the intake passage when the intake port of one cylinder is closed and opened are respectively passed through the above-mentioned communicating portion to all the other cylinders. It is known that supercharging is performed by propagating to an intake port immediately before closing and obtaining a dynamic effect due to intake interference between 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 passage and the intake passage downstream thereof is constant, a dynamic effect is obtained. Can be obtained only in a specific rotation range according to this passage length.

Therefore, the intake passages are gathered upstream of the throttle valve and communicated with the communication portion downstream of the throttle valve, and the communication portion is provided with a shutter valve or the like that opens at high engine speed, and the shutter valve is closed at low engine speed. The length of the passage between the intake ports of both cylinders is made long by the above-mentioned gathering portion and the intake passage downstream thereof, while the shutter valve is opened at the time of high engine rotation to open the passage between the intake ports of both cylinders. It is conceivable that the dynamic effect can be effectively obtained in the entire rotation range of the engine by making the length short so as to be formed by the communication portion and the intake passage downstream thereof.

However, in this case, since the shutter valve is arranged so that the valve body does not project into the intake passage and increase the passage resistance when the shutter valve is opened, it communicates with the valve body when the shutter valve is closed. The dead volume formed between the exhaust passage and the opening to the intake passage becomes large, and the compression wave propagating in the intake passage is attenuated by this dead volume, which improves the dynamic effect at low engine speed. There is a problem that you cannot get it.

Further, since the shutter valve and the like are provided in the communicating portion, there is also a problem that the passage resistance of the shutter valve suppresses the dynamic effect at the time of high engine rotation.

The present invention has been made in view of the above points, and an object of the present invention is to provide a cylindrical rotary valve with a small dead volume in the above-mentioned communication portion to obtain a good dynamic effect at the time of high engine rotation and to achieve communication. The purpose is to properly arrange the intake passages in the vicinity of these parts to obtain good dynamic effects at low engine speeds.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the solution means of the present invention is a communication in which the intake passages of each cylinder group are opposed to each other so as to obtain a dynamic effect by pressure propagation between the cylinder groups. Section, a control valve which is provided in the communication section and which opens at least at high engine speed and high load, and an upstream intake passage connected to each of the intake passages in the vicinity of both sides of the control valve. It is configured as a rotary valve.

(Operation) According to the present invention, according to the present invention, when the control valve is closed at the time of low engine speed, the passage length between the intake ports of both cylinder groups becomes long formed by the intake passage and the upstream intake passage, and the cylinder is Due to the characteristics of the rotary valve, the dead volume between the control valve and the opening of the communication part to the intake passage becomes small, and the low frequency dynamic effect matching the engine speed can be excellently obtained.

On the other hand, when the engine speed is high and the load is high, when the control valve is opened, the passage length between the intake ports of both cylinder groups is shortened by the communication portion and the intake passages downstream thereof, and the intake passages of each cylinder group are formed. Due to the opposing arrangement, the passage resistance near the communication portion becomes small, and the high frequency dynamic effect matching the engine speed can be excellently obtained.

(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 that supplies fresh air to the working chamber 6 of each cylinder C only when the engine is under high load is opened on the side of the side housings 3a, 3b that is closer to the leading side in the rotor rotation direction than the primary port 7. 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, each primary port 7 has a first intake passage 10
Are connected to each other, and the other ends of the respective first intake passages 10 are arranged so as to face each other so as to obtain a dynamic effect due to the pressure propagation between the cylinders, and are communicated with each other by the first communicating portion 11. Further, one end of the second intake passage 12 is connected to each of the secondary main port 8 and the secondary auxiliary port 9, and the other end of each of the second intake passages 12 has a dynamic effect due to pressure propagation between the cylinders. Are arranged to face each other and are communicated with each other by the second communicating portion 13. A valve 14 that opens and closes the communication of the second intake passage 12 with the secondary auxiliary port 9 is provided at one end of the second intake passage 12.
Is driven by a diaphragm type actuator 15 which uses an intake negative pressure as an operation source, and the actuator 15 is controlled by a controller 16. The controller 16 includes throttle valves 17a to 17a provided in the intake passages 10 and 12, respectively.
The opening of 17c, the signal of the air flow sensor 18 and the engine speed signal are input, and as shown in FIG. 4, the valve 14 is opened when the engine is rotating at high speed and high load, while in other operating ranges, the valve 14 is opened. It controls to close.

A first control valve 19 and a second control valve 20 are provided in the first communication section 11 and the second communication section 13, respectively. The first control valve 19 and the second control valve 20 are both cylindrical rotary valves, and the valve bodies 19a and 20a of both control valves 19 and 20 are coaxially arranged and integrally formed, and the intake negative pressure is reduced. It is driven in conjunction with a diaphragm-type actuator 21 whose operating source is. The controller 21 causes the controller 16 to open the first and second control valves 19 and 20 when the engine is rotating at high speed and high load as shown in FIG. 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 like the first upstream intake passages 22, 22.
In addition, 25 is an injector provided in each intake passage 10 and 12,
Reference numeral 6 is an ignition plug arranged in each rotor housing 2a, 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 passage length between the primary ports of the cylinders is the long one formed by the first intake passage 10 and the first upstream intake passage 22, and the passage length between the secondary main ports of both cylinders C, C is the second intake passage 12. In addition, since the length is formed by the second upstream intake passage 24, the low frequency dynamic effect matching the engine speed can be satisfactorily obtained.

Moreover, since the first and second control valves 19 and 20 are cylindrical rotary valves, they are formed between the valve bodies 19a and 20a and the openings of the communicating portions 11 and 13 to the intake passages 10 and 12. The dead 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 primer ports of both cylinders C and C is determined by the first intake passage 10 and the first communication portion 11. In addition to the short length being formed, the passage length between the secondary main ports of both cylinders C, C becomes the short length formed by the second intake passage and the second communicating portion 13, so a high frequency matching the engine speed is achieved. The dynamic effect of can be satisfactorily obtained.

Moreover, since the first intake passages 10 and 10 and the second intake passages 12 and 12 are arranged to face each other and are communicated with each other by the communicating portions 11 and 13, the passage resistance near the communicating portions becomes small, and The physical effect can be further enhanced.

Further, FIGS. 5 and 6 show modified examples of the present invention. This intake device for an engine of the present invention are those applied to reciprocating engines of the series six-cylinder, the cylinder group C ₁ -C ₃ that each cylinder C ₁ -C ₆ intake stroke not continuous, the C ₄ -C ₆ divided, the communicating portion 11 which communicates with the dynamic effect intake passage 10 (resonance effect) to obtain the cylinder groups _{C 1 ~C 3, C 4 ~C} 6 ', 10' are opposed to the pressure propagation between the cylinder groups ′ Is provided, and the communication valve 11 ′ is provided with at least a control valve 19 ′ that opens at high engine speed and high load,
Upstream intake passages 22 ', 22' connected to the respective intake passages 10 ', 10' are provided near both sides of the control valve 19 ', and the control valve 19' is provided.
Is a cylindrical rotary valve, and in addition to the same operation as in the above embodiment, each cylinder C _{1 to} C ₆ is divided into cylinder groups C _{1 to} C ₃ and C _{4 to} C ₆ in which the intake stroke is not continuous. By each cylinder C ₁
It is possible to prevent the attenuation of the pressure wave of ~ C ₆ and to perform efficient pressure propagation in the entire engine rotation range, and to obtain a good dynamic effect.

(Effects of the Invention) As described above, according to the intake system for an engine of the present invention, the control valve forms the communication portion that communicates the intake passage of each cylinder group so as to obtain a dynamic effect by the pressure propagation between the cylinder groups. Since the control valve is a cylindrical rotary valve and the intake passages of each cylinder group are arranged to face each other at the communicating portion in accordance with the engine speed and load, the dead volume when the control valve is closed is reduced. At the same time, the passage resistance in the vicinity of the communication portion when the control valve is opened is reduced, and efficient pressure propagation is achieved in the entire engine rotation range, and good dynamic effects can be obtained.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention, FIG. 1 is an overall schematic configuration diagram, FIG. 2 is a side view of an engine, FIG. 3 is a plan view of the engine, and FIG. 4 is a control valve. It is explanatory drawing which shows an operation | movement area | region. Further, FIG. 5 is an overall schematic configuration diagram in a modified example of the present invention, and FIG. 6 is a view corresponding to FIG. 4 in the modified example. 7 ... Primary port, 9 ... Secondary port,
9 ... Secondary auxiliary port, 10, 10 '... 1st intake passage, 11, 11' ... 1st communicating part, 12, 12 '... 2nd intake passage, 13 ... 2nd communicating part, 19, 19 '... First control valve, 20 ...
… Second control valve, 22,22 ′ …… First upstream intake passage, 24 ……
The second upstream intake passage, C ...... cylinder, C ₁ ~C ₆ ...... cylinder.

Claims (1)

[Claims] Claim: What is claimed is: 1. A communication section in which the intake passages of each cylinder group are opposed to each other so as to obtain a dynamic effect due to pressure propagation between the cylinder groups, and a control which is provided in the communication section and opens at least when the engine is running at high rotation and high load. An intake system for an engine, comprising: a valve; and an upstream intake passage connected to each of the intake passages near both sides of the control valve, wherein the control valve is a cylindrical rotary valve.