JPH079186B2 - 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 Unexamined Patent Publication No. 33-33, the intake passages of each cylinder of a two-cylinder rotary piston engine are joined at the downstream side of a throttle valve, and the passage between the intake ports of both cylinders formed by the joining portion and the intake passages downstream thereof By appropriately setting the length, the closing compression wave and the opening compression wave generated in the intake passage at the time of closing and opening the intake port of one cylinder, respectively, through the above-mentioned confluence part, immediately before the other cylinder is fully closed. It is known that supercharging is performed by propagating to an intake port to obtain a dynamic effect due to intake interference between cylinders.

(Problems to be Solved by the Invention) By the way, as an engine intake device, a low load intake port and a high load intake port are provided in each cylinder, and the first low load intake port is provided in each cylinder of the cylinder group. The intake passage is connected, and the second intake passage is connected to the high-load intake port of each cylinder of the cylinder group, and the flow rate and flow velocity of fresh air supplied to each cylinder by changing the opening of each intake passage according to the load. It is known that the and are set appropriately.

When obtaining the above-described dynamic effect in such an intake device, the first intake passages and the second intake passages are merged with each other, and the compression wave is propagated between the cylinders through each of the merged portions. It is possible to let them do it.

However, in this case, since the first intake passages and the second intake passages are separately joined, the intake system becomes complicated. Further, since the fresh air supply amount of the low load intake port is smaller than the fresh air supply amount of the high load intake port, the passage area of the second intake passage is set larger than that of the first intake passage. , Especially the passage area is large. In other words, the second intake passage having a large passage diameter has a problem that when the curved portion is set to have a sharp curvature, the intake resistance becomes large and the dynamic effect cannot be satisfactorily obtained.

The present invention has been made in view of the above points, and an object of the present invention is to make the intake device compact and reduce the intake resistance by appropriately laying out the first intake passage and the second intake passage. It is to plan.

(Means for Solving the Problems) In order to achieve the above-mentioned object, a solution means of the present invention is to provide first intake passages connected to low-load intake ports of each cylinder of a cylinder group and high-load intake ports. The present invention is directed to an intake device of an engine in which second intake passages connected to each other and having a larger passage area than the first intake passage are joined so as to obtain a dynamic effect by pressure propagation between the cylinder groups. Then, the first intake passage and the second intake passage are arranged along the same plane and curved and extended in an arc shape, and then the first intake passage and the second intake passage are joined to face each other.
The second intake passage is arranged outside the first arc with respect to the first intake passage.

(Operation) With the above configuration, in the present invention, the first intake passage and the second intake passage
Since the intake passage is in the same plane, the height of the intake device is suppressed and the device becomes compact.

In addition, since the first intake passages and the second intake passages are opposed to each other and merge, pressure propagation between the cylinder groups is smoothly performed, and a dynamic effect is favorably obtained.

Further, since the second intake passage is arranged outside the first intake passage, the curved portion of the second intake passage having a large passage area becomes gentle, and the intake resistance of the intake device is reduced. Become.

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

1 to 4 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.

Further, the intermediate housing 1 has primary ports (low-load intake ports) 7 and 7 that supply fresh air to the working chambers 6 of the cylinders C in the entire operating range. Further, a secondary main port (for high load) that supplies fresh air to the working chamber 6 of each cylinder C only on the leading side in the rotor rotation direction of the side housings 3a, 3b from the primary port 7 in the rotor rotation direction is high. A secondary auxiliary port 9 for supplying fresh air to the working chamber 6 of each cylinder C when the engine is rotating at high speed and high load, on the leading side in the rotor rotation direction with respect to each secondary main port 8 Is open.

Further, each primary port 7 has a first intake passage 10
Are connected to each other, and the other ends (upstream ends) of the first intake passages 10 are arranged so as to face each other so as to obtain a dynamic effect due to pressure propagation between the cylinders, and are communicated with each other by the first merging portion 11. ing. Further, one end of a second intake passage 12 having a passage area larger than that of the first intake passage 10 is connected to each of the secondary main port 8 and the secondary auxiliary port 9, and the other end of each second intake passage 12 ( The upstream ends) are arranged so as to face each other so as to obtain a dynamic effect by pressure propagation between the cylinders, and are communicated with each other by the second merging portion 13.

After the upstream ends of the first intake passage 10 and the second intake passage 12 are inverted upward on the side of the housing of the engine, the first intake passage 10 and the second intake passage 12 extend along a substantially horizontal plane P and curved in an arc shape. The first intake passages and the second intake passages face each other and are joined at the first joining portion 11 and the second joining portion 13.

Further, the second intake passage 12 is arranged outside the first circular arc with respect to the first intake passage 10.

Further, a valve 14 for opening and closing 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, and the valve 14 is a diaphragm type operating source is an intake negative pressure. Driven by actuator 15 of
The actuator 15 is controlled by the controller 16. The controller 16 is inputted with the opening degrees of the throttle valves 17a to 17c provided in the intake passages 10 and 12, the signal of the air flow sensor 18 and the engine speed signal. While the valve 14 is opened, the valve 14 is controlled to be closed in other operating regions.

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
Reference numeral 20 is a butterfly valve, both control valves 19 and 20 have a common rotary shaft 27, and they are driven in conjunction with each other by a diaphragm-type actuator 21 which uses intake negative pressure as an operation source. 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 in other operating range
Is controlled to close.

Further, as shown in FIG. 4, the first merging portion 11 and the second merging portion 13 have passage areas of the first intake passage 10 and the second inlet passage 13, respectively.
The intake passage 1 is formed to have a larger area than that of the intake passage 12, and the intake passages 1 and 13 are separated from each other so that the intake passages 1 and 13 are separated from each other.
It is provided offset from 0 and 12.

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 downstream ends of the upstream intake passages 22 and 24 are connected to the lower sides of the intake passages 10 and 12, and the upstream ends of the upstream intake passages 22 and 24 extend substantially above the housing of the engine in the extending direction of the independent intake passages 10 and 12. After that, it curves upward and turns over to face the air cleaner 23. Incidentally, 25 is an injector arranged in each intake passage 10, 12, and 26 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.

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 becomes the first intake passage 10 and the first merging portion 11. The length of the passage formed between the secondary main ports of both cylinders C and C is shorter than that of the second intake passage and the second joining portion 13 formed.
Therefore, the high-frequency dynamic effect matching the engine speed can be favorably obtained.

Further, since the first intake passages 10, 10 and the second intake passages 12, 12 are arranged so as to face each other and are communicated with each other by the confluence portions 11, 13, it is possible to smoothly propagate the pressure between the cylinders, The dynamic effect can be effectively obtained.

Moreover, since the second intake passage 12 is arranged outside the first intake passage 10 in an arc, the curved portion of the second intake passage 12 becomes gentle, and the passage resistance is reduced. The intake resistance of can be reduced.

Further, since the passage areas of the first merging portion 11 and the second merging portion 13 are formed to be larger than the passage areas of the first intake passage 10 and the second intake passage 12, respectively, the intake resistance by the control valves 19, 20 is reduced. It can be reduced.

Further, since the first intake passages 10 and 10 and the second intake passages 12 and 12 are on the same horizontal plane P, the height of the intake device can be suppressed above the engine, and the size of the intake device can be reduced.

Moreover, the first merging portion 11 and the second merging portion 13 are
Since 1 and 13 are provided so as to be offset from each other in the direction in which they are separated from each other, the distance between the first intake passage 10 and the second intake passage 12 can be made as narrow as possible, The intake device can be made more compact.

(Effects of the Invention) As described above, according to the engine intake system of the present invention, the first intake passage and the second intake passage are arranged along the same plane and are curved in an arc shape, Since the first intake passages and the second intake passages are joined so as to face each other and the second intake passages are arranged outside the first arc, the pressure can be propagated efficiently and a dynamic effect can be obtained. It is possible to make the intake device compact and to have a small intake resistance while satisfactorily obtaining it.

[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, FIG. 3 is a plan view of the engine, and FIG. 4 is a cross-sectional view of a merging portion. 7 …… Primary port, 8 …… Secondary main port, 9 …… Secondary auxiliary port, 10 …… First intake passage, 11 …… First confluence part, 12 …… Second intake passage, 13 ……
Second confluence section, C ... Cylinder.

Claims (1)

[Claims] 1. A first intake passage connected to a low load intake port of each cylinder of a cylinder group and a second intake passage connected to a high load intake port and having a larger passage area than the first intake passage. An intake system for an engine, in which the two are combined so as to obtain a dynamic effect by pressure propagation between the cylinder groups,
The first intake passage and the second intake passage extend along the same plane in a curved shape in an arc shape, and then are joined to face each other in the first intake passage and the second intake passage. An intake device for an engine, wherein the two intake passages are arranged outside the first arc passage rather than the first intake passage.