JPH0240023A - Intake device of engine - Google Patents

Abstract

PURPOSE:To reduce fuel consumption by providing a large diameter intake path by cylinder and an aggregate intake path connected to said intake path by cylinder in common in a regular intake path and an intake path for high intake or every cylinder. CONSTITUTION:An intake device 10 of an engine 12 has regular intake paths 24a, 24b and intake paths 26a, 26b for high intake in each of respective cylinders 18, 20, and is provided with large diameter intake paths 42, 44 by cylinder and an aggregate intake path 46 connected in common to the upstream side of said paths 42, 44 in common in regular intake paths 24a, 24b and intake paths 26a, 26b for high intake of each of respective cylinders 18, 20. While supercharging effect due to pulsation is thus ensured, fuel consumption is reduced by reducing intake resistance.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention has a regular intake passage and a high intake intake passage for each cylinder, and in order to obtain a supercharging effect by pulsation in a specific operating region, The present invention relates to an engine intake device that includes a communication passage with an intake passage of another cylinder and controls opening and closing of the communication passage.

[Prior Art] Conventionally, each cylinder has a normal intake passage and a high-intake intake passage, and in order to obtain a supercharging effect by pulsation in a specific operating range, a communication passage with the intake passage of other cylinders is provided. For example, Japanese Patent Application Laid-open No. 77039/1983 is known as a known technique disclosing an engine intake device that is equipped with a communication passage and controls the opening and closing of this communication passage.

According to this known technology, a strong supercharging effect can be obtained in the intake passage for high intake air intake due to the exhaust interference effect and the intake inherent pulsation effect, and therefore, the existing intake needle can be used without using a supercharger etc. By using a simple configuration with a slight design change, it is possible to significantly increase the charging efficiency when the engine is under high load and at high rotation speeds, thereby significantly and effectively increasing the output.

[Problems to be Solved by the Invention] However, in the above-mentioned known technology, in the intake system, the intake pipe from the air cleaner is first divided into two parts: primary (regular use) and secondary (high intake). The primary and secondary intake passages are each further divided into individual cylinders. In the intake passages divided for each cylinder, the primaries are communicated with each other through a communication passage via an on-off valve, and the secondary passages are also communicated with each other through another communication passage via an on-off valve.

As a result, when the above-mentioned on-off valve is closed in a low intake state, the primary intake passage in each cylinder becomes a relatively small diameter passage that continues for a long time, resulting in high intake resistance. As described above, it has been pointed out that this prior art has a problem in that fuel consumption deteriorates as intake resistance increases.

This invention has been made in view of the above-mentioned problems, and an object of the invention is to provide an engine intake system that can reduce fuel consumption by reducing intake resistance while ensuring a supercharging effect due to pulsation. The goal is to provide the following.

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the purpose, an engine intake system according to the present invention has a regular intake passage and a high-intake intake passage for each cylinder. In order to obtain a supercharging effect due to pulsation in a specific operating range, in an engine intake system that is equipped with a communication passage with the intake passage of other cylinders and controls the opening and closing of this communication passage, the regular intake passage of each cylinder is a first communication path that communicates with each other via the first on-off valve; a second communication path that communicates the high-intake intake passage in each cylinder with each other via the second on-off valve; are commonly connected on the upstream side of the part connected to the communication path,
A cylinder-specific intake passage with a common large diameter is provided for the normal intake passage and the high-intake intake passage of each cylinder, and an intake passage gathering part that is commonly connected to the upstream side of these cylinder-specific intake passages. It is a feature.

[Operation] In the engine intake system configured as described above, both the on-off valves are closed in the low intake area, and intake air is introduced into each cylinder through only the regular intake passage. Become. Here, since the regular intake passage is connected to the large-diameter cylinder-specific intake passage, a predetermined intake inertia effect is ensured without increasing intake resistance.

On the other hand, in the high intake region, the on-off valve is opened and the supercharging effect due to pulsation is reliably obtained.

[Embodiment] Below, the configuration of an embodiment of an engine intake device according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a low-pressure engine 12 equipped with an intake system 10 according to one embodiment. This intake device 10 has two intake systems: a low-load (normal use) intake system 14 and a high-load (high intake) intake system 16. It is specified as a two-system, side-intake, boat-type, two-cylinder, low-pressure engine.

That is, this low-pressure engine 12 includes first and second cylinders 18,20.

Each cylinder 18, 20 has a rotor housing 22 having a two-section trochoidal inner peripheral surface, and is located on both sides of this rotor housing 22, and is provided with a common intake passage (hereinafter simply referred to as a primary passage) in the intake device 10, which will be described later. )
24a, 24b and a high intake passage (hereinafter simply referred to as a secondary passage) 26a, 26b are opened, respectively, in a regular intake boat 28 and a high intake intake boat 30 (in the first cylinder 18 on the left side in the figure). is only for the high intake boat 30, and for the second cylinder 20 on the right side,
Only service intake boats 28 are shown, respectively. ), and a substantially triangular rotor 38 that is supported by an eccentric shaft 36 and rotates planetarily within the casing 34.

Here, the rotors 38 of 8.20 in each cylinder have a phase difference of 180 degrees in the rotation angle of the eccentric shaft 36, and as each rotor 38 rotates, the inside of the casing 34 is divided into three working chambers 40. and each cylinder 18.20
The structure is such that the intake, explosion, expansion, and exhaust steps are performed sequentially with the above-mentioned 180 degree phase difference.

Incidentally, the configuration of such a two-cylinder rotary engine 12 is as follows:
Since this is well known, further detailed explanation will be omitted.

Here, the intake system 10, which is a feature of the present invention, has a primary passage 24 for each cylinder 18, 20, as described above.
a, 24b, and secondary passages 26a, 26b. In addition, as shown in the figure, the secondary passage 26a,
26b branches into two just before being connected to the corresponding casing 34, and correspondingly, the high intake air intake bow 1-30 to which this is connected is also divided into two.

The primary passages 24a, 24b and the secondary passages 26a, 26b are connected at the upstream end for each cylinder 182°, and are connected to the downstream ends of the cylinder-specific intake passages 42, 44, respectively. Further, these cylinder-specific intake passages 42 and 44 are combined at their upstream ends and connected to the downstream end of the intake main pipe 46. Although not shown, the upstream end of the intake main pipe 46 is connected to an air cleaner, and a throttle valve 48 is provided at the downstream end of the intake main pipe 46.

Here, a feature of the present invention is that each cylinder-specific intake passage 42, 44 has a cross-sectional area that is the sum of the opening cross-sectional areas of the primary and secondary passages 24a, 26a, 24b, and 26b connected to each cylinder. It is set to have a large diameter so that it has .

On the other hand, both primary passages 24a and 24b are communicated with each other via the first communication passage 5o in their upstream portions. In addition, both secondary passages 26a, 26
b are similarly communicated with each other via the second communication path 52 in their upstream portions. These first
First and second on-off valves 54,56 for opening and closing the passages are provided in the second communicating passages 50,52, respectively. These first and second on-off valves 54 and 56 are both connected to a first actuator 58 as a common drive source, and are driven to open and close in synchronization with each other.

In addition, the secondary passages 26a, 26b are provided immediately upstream of the bifurcated portion of each secondary passage 26a, 26b.
A high load throttle valve 60 is used to intermittently intake air through the valve 6b.
(In FIG. 1, only the high-load throttle valve disposed in the secondary passage 26a connected to the first cylinder 18 is shown.). These high-load throttle valves 60 are both operated by a second actuator 6 as a common driving force.
2 and are driven to open and close in synchronization with each other.

The first and second actuators 58, 62 are both connected to a control unit 64, and are set to operate based on control signals from the control unit 64.

Further, the first and second on-off valves 54 and 56 each include a rotary valve rotatably disposed in a corresponding passage. As shown in FIG. 2 in detail, each rotary valve has a central axis that extends in a direction perpendicular to the extending direction of the passage, and is a cylindrical valve that is rotatably supported around this central axis. a through passage 68 extending along a direction perpendicular to the central axis of the valve body 66 and passing through the valve body 66;
It is composed of.

In the rotary valve configured in this way, the valve body 6 is arranged so that the through passage 68 is along the extending direction of the corresponding passage.
6 is rotated, as shown by the solid line, the through passage 68
Both ends are communicated with the corresponding passages, so that the passages are open. On the other hand, in the state shown by the dashed line in which the through passage 68 is rotated along the direction perpendicular to the extending direction of the corresponding passage, both ends of the through passage 68 are closed by the peripheral wall of the corresponding passage, and thus, The passage will be closed.

The intake operation of the intake device 10 configured as described above will be explained below.

First, the control unit 64 performs the correlation based on FIG.
That is, the driving states of the first and second actuators 58, 62 are controlled according to the engine load state. Specifically, the control unit 64 controls the first actuator 58 to control the first and second on-off valves 54.
6 together, this control unit 64 causes the first actuator 58 to close the first
and the second on-off valves 54 and 56 are set to issue a control signal to open them both.

In addition, this control unit 64 opens and closes the high-load throttle valve 60 in accordance with the opening degree of the throttle valve 48 in the low intake region A and the high intake region B, as shown by the broken line in FIG. It is configured to issue a control signal to the second actuator 62.

Specifically, 5, O○○ to 7, OOOr, which require high output
pm, that is, in the high intake region indicated by the symbol B, each cylinder 18. The 20 high-intake boats 30 are opened together with the regular intake port 28 to supply intake air. At this time, when the high intake boat 30 of one cylinder, for example, the second cylinder 20, is opened, a pressure wave is generated in the secondary passage 26b connected thereto. This pressure wave appropriately changes the length between the high intake boats 30 of both cylinders 18 and 20 (that is, the distance via the open second communication path 52) to a value corresponding to the high rotational speed. By setting, the high intake boat 30 immediately before fully closing the cylinder 18 having a phase difference of 180 degrees is transmitted through the second secondary passage 26b, the second communication passage 52, and the first secondary passage 26A. (exhaust interference effect).

At the same time, in the first cylinder 18, due to the start of intake in the high intake boat 30, the secondary passage 26
An expansion wave is generated within a. By appropriately setting the length between the high-intake boat 30 and the connecting portion of the intake passages 42 and 44 for both cylinders, this expansion wave is reversed into a compression wave and reflected at this connecting portion. Returning to the intake boat 30, it is reversed into an expansion wave and reflected, and again, at the connection part, it is reversed into a compression wave and reflected as a secondary pulsating wave of the compression wave.
It is propagated to the high intake boat 30 just before fully closing (intake specific pulsation effect).

As a result, due to the opening compression wave and the secondary pulsating compression wave, the high intake boat 30 immediately before the first cylinder 18 is fully closed.
This suppresses the blowback of intake air from the working chamber 40.
This results in strong supercharging. At the same time, in the second cylinder 20, the opening compression wave from the first cylinder 18 and the secondary pulsating compression wave of the second cylinder 20 itself are propagated to the high intake boat 30 just before fully closing. Strong supercharging will occur.

Therefore, in the high-intake intake system 16 of each cylinder 18, 20, due to the strong supercharging effect due to the exhaust interference effect on the high-intake boat 30 just before fully closing and the intake-specific pulsation effect, the engine can be operated under high load and at high speed. Area (5,000~7
．． The intake air filling efficiency at (OOOrpm) is significantly increased, and the output can be significantly improved.

On the other hand, low intake area A (for example, engine speed 1.00
In the low rotation state (0 to 5,000 rpm), the first
The first and second on-off valves 54,56 are closed via the actuator 58, and the intake air flows through the primary passage 24a.
, 24b to the first and second cylinders 18, 20, respectively. In this way, since the intake air is sent into the working chamber 40 through the single regular intake port 28, the speed of the intake air entering the working chamber 40 is set to a high value, and as a result, the speed of the intake air entering the working chamber 40 is set to a high value. A good intake air flow is generated at , and the fuel injected into the working chamber 40 through a fuel injection valve (not shown) and the intake air are mixed well,
High combustion efficiency will be achieved.

Here, as mentioned above, in the low intake region A, the first and second on-off valves 54.56 are closed and the first and second communication passages 50.52 are closed. ,
Although the above-mentioned exhaust interference effect cannot be obtained, the intake-specific pulsation effect can be similarly obtained, and intake air is carried out in a supercharged state.

In particular, in this embodiment, the cylinder-specific intake passage 42.
44 is formed to have a large diameter, the intake pipe resistance, which is a major factor that hinders intake, is kept low in the low intake region △, so the overall intake resistance is reduced to a small value. It will become. As a result,
Intake is performed smoothly in the low intake area A, and fuel efficiency is improved.

Here, the control unit 64 operates in an intake region C that is lower than the low intake state indicated by the symbol A (for example, the rotation speed is set slightly higher than the idling rotation speed).
1. In the rotation state with the upper limit of OOOrpm),
For the purpose of reducing intake resistance as much as possible, control signals are set to be issued to the first and second actuators 58 and 62 in order to open all the first and second on-off valves 5456 and the high-load throttle valve 60. There is.

It goes without saying that this invention is not limited to the configuration of the one embodiment described above, and can be modified in various ways without departing from the gist of the invention.

For example, in the embodiment described above, the engine is described as being applied to a two-cylinder rotary engine, but the present invention is not limited to this, and the present invention is similarly applicable to a multi-cylinder reciprocating engine.

[Effects of the Invention] As described in detail above, the engine intake system according to the present invention has a regular intake passage and a high intake intake passage for each cylinder, and has a supercharging effect due to pulsation in a specific operating region. In order to achieve this, in an engine intake system which is provided with a communication passage with the intake passage of other cylinders and which controls the opening and closing of this communication passage, a first opening/closing valve is provided which connects the regular intake passages of each cylinder to each other via a first on-off valve. a second communication passage that communicates the high-intake intake passages in each cylinder with each other via a second on-off valve; a large-diameter cylinder-specific intake passage that is connected to the cylinder and is common to the regular intake passage and the high-intake intake passage of each cylinder;
It is characterized in that the upstream sides of these intake passages for each cylinder are commonly connected to an intake passage collection part.

Therefore, according to the present invention, there is provided an intake system for an engine that can reduce fuel consumption by reducing intake resistance while ensuring the supercharging effect due to pulsation.

[Brief explanation of the drawing]

FIG. 1 is a front view schematically showing the structure of an embodiment of an engine intake system according to the present invention; FIG. 2 is a cross-sectional view showing the structure of an on-off valve; and FIG. FIG. 3 is a diagram showing the operating state of the actuator of FIG. In the figure, 10... Intake system, 12... Rotary engine, 14... Regular intake system, 16... High intake intake system, 18... First cylinder, 20... Second cylinder. cylinder, 22
...Rotor housing, 24a; 24b...Common intake passage (primary passage), 26...: 26b;
・・High intake air intake passage (secondary passage), 28...
Regular intake boat, 30... High intake intake boat, 32
...Side housing, 34...Casing, 36
...Eccentric shaft, 38...Rotor,
40... Working chamber, 42.44... Intake passage by cylinder,
46... Intake main pipe, 48... Throttle valve, 50...
...First communication path, 52...Second communication path, 54...
- First on-off valve, 56... Second on-off valve, 58...
First actuator, 60...High load throttle valve, 6
2... Second actuator, 64... Control unit, 66... Valve body, 68... Penetration passage. Member of ``Wobao ni ku ro fankokigo''

Claims (1)

[Claims] Each cylinder has a regular intake passage and a high intake intake passage,
In order to obtain a supercharging effect by pulsation in a specific operating range, in an engine intake system that is equipped with a communication passage with the intake passage of other cylinders and controls the opening and closing of this communication passage, the regular intake passage of each cylinder is connected to the first intake passage. a first communication passage that communicates with each other via an on-off valve; a second communication passage that communicates the high-intake intake passages in each cylinder with each other via a second on-off valve;
A large-diameter cylinder-specific intake passage that is commonly connected on the upstream side of the connected portion of the communication passage and is common to the normal intake passage and the high-intake intake passage of each cylinder, and the upstream side of these cylinder-specific intake passages is An engine intake system characterized by comprising a commonly connected large-diameter intake passage collection section.