JP2570912Y2 - Air duct device for engine intake - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air duct device arranged in an intake system of an engine.

[0002]

2. Description of the Related Art Conventionally, an air duct device schematically shown in FIG. 8 is provided in an intake system of an engine (1991).
June 2006, Nissan Motor Co., Ltd., "NISSAN Cedric Gloria New Model Guide", page B-27). That is, the other end of the intake duct 43 provided with the first and second intake ports 41 and 42 at one end thereof is connected to one surface of the air cleaner 44, and the other surface of the air cleaner 44 is connected to the intake of the engine. An outlet duct 45 connected to the manifold communicates with the manifold. An outer peripheral portion of the intake duct 43 and between the intake ports 41 and 42 and the air cleaner 44,
The resonator 46 is integrally formed, and the resonator 46 has a closed space of a predetermined volume.

In such a structure, when the engine rotates, air is sucked from the intake ports 41 and 42, and the air flows through the intake duct 43 and the air cleaner 44 and is introduced into the engine from the intake manifold. At this time, an intake air noise is generated when air flows into the intake ports 41 and 42. However, since a resonator 46 having a predetermined volume is provided in the middle of the intake duct 43, The intake air noise in the frequency band corresponding to the volume is attenuated, and thus the intake air noise can be reduced. Further, two intake ports 41 and 42 are provided so that a sufficient intake area is set.
Since the cross-sectional area is sufficiently set, the airflow resistance is reduced, and the output performance of the engine can be improved.

[0004]

However, such a conventional intake air duct device has a structure in which only two intake ports 41, 42 are provided at one end of an intake duct 43, Since air is always sucked from each of the suction ports 41 and 42, the suction air noise at the time of suction is always 2
It will occur from several places. Therefore, both intake ports 4
By providing the intake ports 1 and 42, the suction area can be increased and a large amount of air can be introduced at a high engine speed to improve the output performance. In an operating state where silence is prioritized over performance, intake air noise cannot be sufficiently reduced.

Moreover, since the intake air noise is attenuated by a single resonator 46, the frequency band that can be attenuated is uniquely determined by the volume of the resonator 46. On the other hand, the frequency of the intake air noise changes according to the engine speed, the engine speed increases, the intake air amount increases, and the frequency also increases as the flow velocity increases. Therefore, if the characteristic that can attenuate the low frequency band is set in the resonator 46, it is possible to attenuate the intake air noise in the low frequency band generated when the engine is running at a low speed. The intake air noise in the frequency band cannot be attenuated. Also,
Conversely, if the characteristic that can attenuate the middle frequency band is set in the resonator 46, even if it is possible to attenuate the intake air noise in the middle frequency band that occurs when the engine is rotating at a medium speed, the low noise that occurs when the engine is running at a low speed is reduced. The intake air noise in the frequency band cannot be attenuated. Therefore, it has been impossible to reduce the intake air noise in both the low frequency band and the medium frequency band generated corresponding to the low rotation speed range to the middle rotation speed range of the engine where quietness is prioritized.

The present invention has been made in view of such a conventional problem, and reduces intake air resistance as required to improve engine output performance. In addition, the intake air noise in a plurality of frequency bands is improved. It is an object of the present invention to provide an air intake duct device for an engine that can reduce the amount of air.

[0007]

In order to solve the above problems SUMMARY OF THE INVENTION According to the present invention includes a first intake duct and the other end portion inlet is provided at one end communicating with the air cleaner with a space, the Both ends are connected to the first intake duct and one end is closed
Can be used as a resonator for low frequency band
A bypass duct having a operable length and volume, a closed position for closing one end of the bypass duct ,
Open and connect the first intake duct to the bypass duct.
A first switching valve rotatable between an open position and a closed position between the communication portion with the air outlet, and an intake port provided at one end and the other end connected to the air cleaner to close the intake port.
The middle frequency higher than the low frequency band
It has a volume and length that can function as a band resonator
A second intake duct that opens and a second position that can rotate between an open position that opens the intake port of the second intake duct and a closed position that closes the intake port .
Switching valve and driving the first and second switching valves respectively
And an actuator that rotates the engine
The engine speed is controlled based on the engine speed,
The first and second switching valves are both closed.
Position in the middle rotation range higher than the low rotation range.
The first valve is in the open position and the second valve is in the closed position
High rotation range higher than the middle rotation range.
The first valve is in the closed position and the second valve is in the open position
And a controller for driving the

[0008]

In the above construction, when the engine speed is in a low rotation range
The controller controls the actuator to
The first and second switching valves are both driven to the closed position.
Then, air is sucked only from the air inlet of the first air intake duct and introduced into the air cleaner. At this time, attach both ends
Since one end of the bypass duct communicating with the intake duct is closed by the first switching valve, only the other end is in a closed pipe communicating with the first intake duct. Therefore, the bypass duct acts as a resonator for a low frequency band of the intake air noise at the time of low rotation generated in the first intake duct due to its length and volume, and attenuates the intake air noise.

Further, the engine speed is in the middle speed range.
And the controller controls the actuator to control the first
Driving the second valve to the closed position with the valve in the open position;
You. Then, air is sucked only from the intake port of the first intake duct, and at this time, the first intake duct is connected to the bypass duct.
Is closed by the first valve between the communication parts of
Then, the sucked air is introduced into the air cleaner via the bypass duct. Also, the second intake duct is
Since the suction port is closed by the switching valve, only the other end communicates with the closed space of the air cleaner and is closed. Therefore, due to its length and volume, the second intake duct acts as a medium frequency band resonator for intake air noise transmitted into the air cleaner. Moreover, when a large amount of air is not required to be introduced into the engine as in the case of the low rotation speed or the middle rotation speed, the bypass damper is used.
To close the air outlet and allow air to flow only through the first intake duct
Single path or bypass by closing the first intake duct
Inhalation by making a single passage through the duct
The sound source of the air sound becomes single, and the quietness is enhanced.

Further, the engine speed is in a high speed range.
And the controller controls the actuator to control the first
Driving the second valve to the open position with the valve in the closed position;
You. Then, on the first intake duct side, the air sucked from the intake port flows directly to the air cleaner without going to the bypass duct side, and the air also flows from the second intake duct to the air cleaner. Thus, the ventilation resistance increases the overall ventilation cross-sectional area and reduces the ventilation resistance, thereby enhancing the output performance of the engine.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. That is, as shown in FIG. 1, a first intake port 2 is formed at one end of the first intake duct 1, and the other end is communicated with one surface of an air cleaner 3 having a closed space therein. I have. Both ends of a bypass duct 4 bent in a U-shape are communicated with a middle portion of the first intake duct 1, and an end of the bypass duct 4 communicated downstream with respect to the first intake duct 1. Has a first switching valve 5
Is provided. The first switching valve 5 has a closed position for closing an end of the bypass duct 4 shown in FIG. 3 and a communication portion between the first intake duct 1 shown in FIG.
It closes in between and rotates to an open position where the bypass duct 4 is opened. When the end portion is closed by the first switching valve 5, the bypass duct 4 has a length and a volume that can function as a low-frequency band resonator that can attenuate low-frequency band intake air noise. I have.

Further, on one side of the air cleaner 3,
One end of a second intake duct 6 having a diameter larger than that of the first intake duct 1 and having a length and a volume different from that of the bypass duct 4 is communicated. The second intake duct 6
A second intake port 7 is provided at the other end, and a second switching valve 8 that opens and closes the second intake port 7 is provided. The second intake duct 6 can function as a resonator for a medium frequency band of the intake air noise transmitted into the air cleaner 3 when the second intake port 7 is closed by the second switching valve 8. It has a length and a volume. An outlet duct 9 communicating with the intake manifold of the engine is connected to the other surface of the air cleaner 3.

On the other hand, an input port of the controller 10 receives an engine speed from an engine speed sensor 11 and an output port thereof includes a first actuator 31 for opening and closing the first switching valve 5 and a second switching valve 8. Is connected to a second actuator 32 that opens and closes.

Next, the operation of this embodiment having the above configuration will be described with reference to the operation flowchart of the controller 10 shown in FIG. That is, the controller 10 starts the control according to this flowchart with the start of the engine, and first determines whether or not the engine speed is less than 2,000 rpm (S1). If this determination is YES and the engine speed is less than 2,000 rpm, an operation signal is output to each of the actuators 31 and 32, and both the first switching valve 5 and the second switching valve 8 are closed. It is driven (S2). Then, as shown in FIG. 3, one end of the bypass duct 4 is closed, the intake port 7 of the second intake duct 6 is closed, and only the intake port 2 of the first intake duct 1 is rotated by rotation of the engine. The air is sucked and introduced into the air cleaner.

At this time, one end of the bypass duct 4 having both ends communicating with the first intake duct 1 is closed by the first switching valve 5, so that only the other end communicates with the first intake duct 1. The tube is closed. Therefore, the bypass duct 4 has the first
It acts as a low-frequency band resonator for the intake air noise generated in the intake duct 1 and attenuates the intake air noise. Therefore, the low-frequency intake air noise generated when the engine is running at a low speed is attenuated and reduced by the function of the bypass duct 4 as a resonator.

If the determination in S1 is NO and the engine speed is not less than 2,000 rpm, the engine speed is further increased from 2,000 rpm to 4,000.
It is determined whether it is less than rpm (S3). If this determination is YES and the engine speed is 2,000 rpm
If the rotation speed is less than 4,000 rpm, an operation signal is output to each of the actuators 31 and 32 to open the first switching valve 5 and close the second switching valve 8 (S
4). Then, as shown in FIG. 4, the first switching valve 1
As a result, the first intake duct 1 is closed and the bypass duct 4 is opened, and the second switching valve 8 closes the intake port 7 of the second intake duct 6. Therefore, the first
Although air is sucked only from the intake port 2 of the intake duct 1,
Since the first intake duct 1 is closed by the first switching valve 5, the air taken in from the intake port 2 of the first intake duct 1 is introduced into the air cleaner via the bypass duct 4.

At this time, as described above, the second intake duct 6
Since the suction port 7 is closed by the second switching valve 8, only one end is in a closed pipe state communicating with the closed space of the air cleaner 3. Therefore, due to its length and volume, the second intake duct 6 functions as a medium frequency band resonator for intake air noise transmitted into the air cleaner 3. Therefore, the mid-frequency intake air noise generated during the middle rotation of the engine is attenuated and reduced by the function of the second intake duct 6 as a resonator. In addition, when a large amount of air is not required to be introduced into the engine as in the case of the low engine speed where the engine speed is less than 2,000 rpm or the middle engine speed where the engine speed is less than 2,000 rpm and less than 4,000 rpm, Since the air is sucked only from the intake port 2 of the first intake duct 1, a single sound source of the intake air noise is obtained, and the quietness at low and middle rotations is improved.

On the other hand, if the determinations of S2 and S3 are both NO, the engine speed is in a high rotation state of 4,000 rpm or more.
An operation signal is output to the first and second switches 32, and the first switching valve 5 is closed and the second switching valve 8 is opened (S5). Thereby, as shown in FIG. 5, the intake port 7 of the second intake duct 6 is opened, and the one end of the bypass duct 4 is closed by the second switching valve 8. Therefore, the first
On the intake duct side 1, the air sucked from the intake port 2 flows directly to the air cleaner 3 without going to the bypass duct 4 side, and the air also flows from the second intake duct 6 to the air cleaner 3. . Thus, the overall ventilation cross-sectional area is increased, and the ventilation resistance is reduced, whereby the output performance of the engine can be enhanced.

In the state of less than 2,000 rpm shown in FIG. 3, the second intake duct 6 can be operated similarly to the state of not less than 2,000 rpm and less than 4,000 rpm shown in FIG.
Functions as a resonator. Therefore, even when the engine is running at a low speed, it is possible to attenuate the medium frequency component included in the intake air noise.

FIG. 6 shows another embodiment of the present invention, in which a supercharger 12 includes a turbine 1 disposed at both ends of a coaxial axis.
An exhaust inflow port 15 communicated with an exhaust manifold of the engine and an exhaust outflow port 16 communicated with an exhaust pipe 33 are provided on the turbine 13 side. A bypass passage 17 communicating with the exhaust inflow port 15 and the exhaust outflow port 16 is provided on the turbine 13 side. An opening of the bypass passage 17 communicating with the exhaust inflow port 15 is formed by a swing valve 18. It can be opened and closed.

On the other hand, a suction port 19 open to the atmosphere and a discharge port 20 communicating with an intake manifold of the engine are provided on the compressor 14 side. A supply tube 22 for supplying a supercharging pressure P to a swing valve controller 21 is connected to the discharge port 20, and the swing valve controller 21 is linked to the swing valve 18.

On the other hand, a link 23 is linked to the second switching valve 8, and a rod 25 of an actuator 24 is pivotally supported at one end of the link 23. The actuator 24, as shown in FIG.
It has a housing 26, a boost pressure inlet 27 is provided on one side wall of the housing 26, and the rod 25 is inserted into the other side wall facing the one side wall. A diaphragm 28 is provided inside the housing 26, and the rod 25 is located at the center of the diaphragm 28.
Is fixed, and a return spring 29 is elastically inserted between the other side wall of the housing 26 and the diaphragm 28. One end of a supercharging tube 30 is connected to the supercharging pressure inlet 23, and the other end of the supercharging tube 30 is connected to the supply tube 22.
Is communicated to.

[0023] The first switching valve 5 is similar to the embodiment shown in FIG. 1, is driven to be opened and closed by the first actuator 31, first actuator 31 is an engine rotational speed inputted from the engine speed sensor 11 It is controlled by the controller 10 operating based on the above. Therefore, the first
The switching valve 5 is driven closed when the engine speed is less than 2,000 rpm, opened when the engine speed is 2,000 rpm or more and less than 4,000 rpm, and closed when the engine speed is 4,000 rpm or more.

In this embodiment having the above-described structure, when exhaust gas is supplied from the exhaust manifold to the exhaust inflow port 15 with the start of the engine, the turbine 13 is rotated by using the exhaust gas as a drive source, and the turbine 13 is rotated. 13 and the compressor 14 rotates. Thereby, the air is sucked from the suction port 19 and compressed, and the supercharging pressure P
Is sent to the engine via an intake manifold.

At the same time, the supercharging pressure P is
2, and the boost pressure inlet 2 through the boost pressure tube 30
7 leads into the housing 26. At this time, if the supercharging pressure P is, for example, less than 50 mmHg, the diaphragm 28 is pressed and deformed by the return spring 29, and the rod 25 is
In a state displaced inward. Accordingly, the second switching valve 8 is driven to close, and the intake port 7 of the second intake duct 6 is closed by the second switching valve 8.

When the supercharging pressure P rises to 50 mmHg or more and the supercharging pressure P is supplied into the housing 26, the diaphragm 28 swells and deforms against the return spring 29, and the rod 25 It protrudes and moves to the outside of the housing 26. As a result, the end of the link 23 is pressed, and the second switching valve 8 is rotated to open and the second switching valve 8 is opened.
The intake port 7 of the intake duct 6 is opened.

That is, in this embodiment, the second switching valve 8 is opened during acceleration running in which the supercharging pressure becomes 50 mmHg or more, whereby the intake cross-sectional area increases and the intake resistance decreases, and Output performance is improved, and conversely, when the supercharging pressure is 50
When it is less than mmHg, the second switching valve 8 is closed, and the silencing performance of the intake air noise is enhanced as in the above-described embodiment.

[0028]

As described above, according to the present invention, the first intake duct communicated with the air cleaner and the first intake duct are provided.
Low end by communicating both ends to one end and closing one end
Length and volume that can function as a wavenumber band resonator
A bypass duct, communicates the other end to the air cleaner with air inlet is provided at one end the intake with
Higher than the low frequency band by closing the mouth
A volume that can function as a resonator
A second intake duct having a length, and an engine speed
Is one of the ends of the bypass duct when
Part and the second intake duct are closed,
Opens the bypass duct and bypasses the first intake duct
Closed between the communication sections with the
Close one end of the bypass duct and open the second valve
I did it. Therefore, when the engine speed is low
Air noise in the middle and middle rotation ranges.
Unitization of sound sources and the corresponding resonator function
If the engine speed is higher and the engine speed is higher
In this case, it is necessary to increase the cross-sectional area of the intake air to reduce the ventilation resistance.
Can be. Therefore, while improving the output performance of the engine,
In an operating state where quietness is prioritized over output performance of the engine, such as when the engine is running at a low speed or a medium speed, the quietness can be improved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an embodiment of the present invention.

FIG. 2 is an operation flowchart of the embodiment.

FIG. 3 is an explanatory diagram showing a state in which both the first and second switching valves of the embodiment are closed.

FIG. 4 is an explanatory diagram showing a state where a first switching valve of the embodiment is open and a second switching valve is closed.

FIG. 5 is an explanatory diagram showing a state in which a first switching valve of the embodiment is closed and a second switching valve is open.

FIG. 6 is a conceptual diagram showing another embodiment of the present invention.

FIG. 7 is a schematic diagram showing details of the actuator of the embodiment.

FIG. 8 is a schematic diagram showing a conventional intake air duct device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st intake duct 2 intake port 3 air cleaner 4 bypass duct 5 1st switching valve 6 2nd intake duct 7 intake port 8 2nd switching valve

Claims (1)

(57) [Scope of request for utility model registration] A first intake duct having an intake port provided at one end thereof and an other end communicating with an air cleaner having a space; and both ends communicating with the first intake duct and having one end closed. Is
Can function as a resonator for low frequency band
A bypass duct having a length and a volume, a closed position for closing one end of the bypass duct , and the one end
And the first intake duct is connected to the bypass
Pivotable to open position that closes between communicating parts with the duct
A first switching valve having an intake port at one end and the other end communicating with the air cleaner to close the intake port.
Resonator for middle frequency band higher than the low frequency band
A second intake duct having a volume and a length capable of functioning as an air inlet, and an open position and a closed position for opening the intake port of the second intake duct
A second switching valve rotatable to a closed position in which the first and second switching valves are driven.
And the actuator based on the engine speed.
When the engine speed is within a predetermined low speed range,
And the second switching valve are driven to the closed position.
In the case of a middle rotation range higher than the rotation range, the first valve is
The second valve is driven to the closed position to the open position, and the
When the engine speed is higher than the shift range, the first valve is closed.
Control for driving said second valve to an open position in a position
Intake duct system for an engine, characterized in that it includes and La, the.