JP2002221050A - Noise reducing device for supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly prevent emission of a sound generated when a high pressure air is released at one time to an intake passage located upstream of a supercharger or emission of a surging sound. SOLUTION: A bypass 86 is installed to generate connection between the upstream and downstream of the supercharger 36 provided in the intake passage 32, and on the way of bypass, an air bypassing valve 114 is installed to open and close the bypass, and a control valve 116 to open and close the suction passage is installed upstream of the connecting part of the suction passage portion located upstream of the supercharger with the bypass, while a pressure sensor 100 to sense the pressure of the suction air is installed in the suction passage portion located downstream of the supercharger, and the arrangement further includes a throttle sensor 98 to sense the motion of a throttle valve 34 and a controlling means 106 to control the control valve so that its degree of opening is changed in the direction of closing when the pressure given by the sensor exceeds the set value for opening of the air bypassing valve during the decelerative operation and the throttle valve has changed abruptly in the direction of closing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise reduction device for a turbocharger, and more particularly to a noise or surge noise when high-pressure air is released at a stretch to an intake passage upstream of the turbocharger. Further, the present invention relates to a noise reduction device for a supercharger that reliably prevents the discharge of a sound generated by the supercharger when air is to be further supplied.

[0002]

2. Description of the Related Art In an internal combustion engine mounted on a vehicle,
A turbocharger in the middle of the intake pipe (also called "turbocharger")
Some are arranged. The internal combustion engine provided with this supercharger supplies supercharging pressure to the internal combustion engine by the supercharger to improve the output.

[0003] As a noise reduction device for a turbocharger, Japanese Utility Model 3
There is a device disclosed in Japanese Patent Application Publication No. 38414. An intake passage control device for a mechanical supercharger disclosed in this publication includes a mechanical supercharger provided in an intake passage, a throttle valve provided downstream of the supercharger, and a throttle valve provided between the supercharger and the throttle valve. In the internal combustion engine provided with a bypass for bypassing the intake passage to the upstream side of the turbocharger, a normally-open type shutoff valve is provided in the intake passage upstream of the bypass passage opening upstream of the turbocharger, and air flowing back through the bypass passage is provided. Under a predetermined operating condition with a large amount of air, the shutoff valve is fully closed and discharged to the upstream of the intake passage, thereby blocking the pulsating noise of air flowing backward through the bypass passage, thereby preventing noise.

[0004]

By the way, in the conventional internal combustion engine with a supercharger, when the throttle is returned from the operation in the supercharging region, that is, when the throttle opening is moved in the closing direction, noise is generated.

[0005] The noise generated when the throttle is released includes surge noise generated when the compressor of the turbocharger exceeds the limit of compressing (feeding) air,
There is a sound generated when the high-pressure air trapped between the compressor and the throttle of the supercharger is discharged through the bypass valve to the upstream side of the compressor of the low-pressure turbocharger.

As described above, the sound is generated in the vicinity of the supercharger, but the sound is transmitted through the intake pipe, enters the air cleaner, is amplified by the air cleaner, enters the passenger compartment, and is recognized as noise. Therefore, there is an inconvenience that comfort in the vehicle compartment is impaired.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to an internal combustion engine having a supercharger between an air cleaner in an intake passage and a throttle valve in order to eliminate the above-mentioned disadvantages. A bypass passage communicating between the upstream side and the downstream side is provided, and an air bypass valve for opening and closing the bypass passage is provided in the middle of the bypass passage, and a connection portion between the intake passage and the bypass passage on the upstream side of the supercharger is provided. Also provided is a control valve for opening and closing the intake passage at an upstream portion, a pressure sensor for detecting the pressure of intake air downstream of the supercharger in the intake passage, and a throttle sensor for detecting the movement of the throttle valve. When the pressure detected by the pressure sensor is equal to or greater than a set value for opening the air bypass valve during deceleration and the throttle valve suddenly changes in the closing direction, And characterized in that a control means for controlling so as to change the opening degree of the serial control valve in the closing direction.

Further, in an internal combustion engine having a supercharger between an air cleaner and a throttle valve in an intake passage, a bypass passage is provided for communicating an upstream side and a downstream side of the supercharger in the intake passage. An air bypass valve that opens and closes a bypass passage is provided on the way, and a control valve that opens and closes an intake passage at a portion upstream of a connection portion between the intake passage and the bypass passage on the upstream side of the turbocharger is provided.
A pressure sensor for detecting the pressure of the intake air is provided downstream of the supercharger in the intake passage, a throttle sensor for detecting the movement of the throttle valve is provided, and the pressure detected by the pressure sensor is A control means is provided for controlling the opening of the control valve to change to the closing direction when the throttle valve suddenly changes to the closing direction at a pressure and below the set value for opening the air bypass valve during deceleration. And

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION
When the pressure detected by the pressure sensor is equal to or higher than the set value for opening the air bypass valve during deceleration and the throttle valve suddenly changes in the closing direction, the control means controls the opening of the control valve to change in the closing direction, This prevents the sound from being emitted when the high-pressure air is released to the intake passage upstream of the supercharger at a stretch.

When the pressure detected by the pressure sensor is a pressure in the supercharging region and is equal to or less than a set value for opening the air bypass valve during deceleration, and the throttle valve suddenly changes in the closing direction, the control means controls the control valve. The opening degree is controlled to change in the closing direction to prevent the release of surge noise (sound generated by the supercharger when air is further supplied to high-pressure air).

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 4 show an embodiment of the present invention. 2, reference numeral 2 denotes an internal combustion engine mounted on a vehicle (not shown), 4 denotes a cylinder block, 6 denotes a cylinder head, 8 denotes a head cover, 10 denotes a piston, 12 denotes a combustion chamber, 14 denotes an intake port, 16 denotes an exhaust port, 18 Is an intake valve, and 20 is an exhaust valve.

The internal combustion engine 2 has an air intake passage 32 communicating with an intake port 14 by sequentially connecting an air cleaner 22, an intake pipe 24, a throttle body 26, a surge tank 28, and an intake manifold 30 as an intake system. . A throttle valve 34 is provided in the intake passage 32 of the throttle body 26.

At this time, in the middle of the intake pipe 24, that is, between the air cleaner 22 and the throttle valve 34, a supercharger (also called "turbocharger") 36 is provided from the upstream side.
Of the compressor 38 and the intercooler 40 are sequentially arranged.

The internal combustion engine 2 is provided with an exhaust passage 48 that sequentially connects an exhaust manifold 42, an exhaust pipe 44, and a catalytic converter 46 as an exhaust system and communicates with the exhaust port 16. A catalyst 50 is provided in the catalytic converter 46.

A turbine 52 of the supercharger 36 is disposed in the exhaust pipe 44, and a wastegate passage 54 that bypasses the turbine 52 is provided.
A waste gate valve 56 is provided in the waste gate passage 54.

The internal combustion engine 2 has a head cover 8 with a PC
A V-valve 58 is attached and provided.
A first blow-by gas passage 60 is provided for communicating the inside of the head cover 8 with the intake passage 32 of the surge tank 28 through the second passage, and a second blow-by gas is provided for communicating the inside of the head cover 8 with the intake passage 32 upstream of the throttle body 26. A passage 62 is provided.

The internal combustion engine 2 is provided with a fuel injection valve (also referred to as an "injector") 64 as a fuel injection means in the cylinder head 6 so as to be directed toward the combustion chamber 12. The fuel injection valve 64 is connected to a fuel tank 68 by a fuel supply passage 66. A fuel pump 70 for supplying fuel to the fuel supply passage 66 is provided in the fuel tank 68. In the middle of the fuel supply passage 66 in the fuel tank 68,
A fuel filter 72 and a pressure regulator 74 for adjusting fuel pressure are provided.

The fuel tank 68 has an evaporation passage 76
Is connected through a two-way check valve 78. The other end of the evaporation passage 76 communicates with the canister 80. One end of a purge passage 82 communicates with the canister 80. The other end of the purge passage 82 communicates with the intake passage 32.

In the middle of the purge passage 82,
A one-way valve 84 is provided.

Further, the intake passage 32 of the throttle body 26 bypasses the throttle valve 34 to the engine 2.
A bypass passage 86 is provided for communicating the air passage 32 with the intake passage 32 of the surge tank 28. A bypass air amount control valve (also referred to as an “ISC valve”) 88 for adjusting the amount of bypass air is provided in the middle of the bypass passage 86.

The internal combustion engine 2 is provided with an ignition coil 90 for igniting a spark plug (not shown), a crank angle sensor 92 for detecting a crank angle for discriminating a cylinder and an engine speed, and detecting an intake air temperature. An intake air temperature sensor 94 is provided, a water temperature sensor 96 for detecting a cooling water temperature of the internal combustion engine 2 is provided, a throttle sensor 98 for detecting a throttle opening of the throttle valve 34 is provided, and an intake air pressure in the intake passage 32 is detected. A pressure sensor 100 is provided in communication with an upstream portion of the surge tank 28, and an air-fuel ratio detecting means for detecting an air-fuel ratio in an exhaust passage 48 downstream of a junction with the wastegate passage 54, for example, in the exhaust gas. An O2 sensor 102 for detecting the oxygen concentration of the gas is provided.

The fuel injection valve 64, fuel pump 70, bypass air amount control valve 88, ignition coil 90, crank angle sensor 92, intake air temperature sensor 94, and water temperature sensor 9
6, the throttle sensor 98, the pressure sensor 100, the O2 sensor 102, and an idle switch 118 described later are connected to control means (also referred to as “ECM”) 106 that constitutes the noise reduction device 104. Reference numeral 108 denotes a battery, and 110 denotes a knock sensor that outputs a knock level.

The supercharger 3 in the intake passage 32
A bypass passage 112 is provided for communication between the upstream side and the downstream side of the bypass passage 6.
An air bypass valve (also referred to as “ABV”) 114 that opens and closes the intake passage 32 is provided to open and close the intake passage 32 at a position upstream of the supercharger 36 and upstream of a connection portion between the intake passage 32 and the bypass passage 112. A pressure control valve (also referred to as an "NR valve" or a "noise reduction valve") 116 for detecting the pressure of intake air downstream of the supercharger 36 in the intake passage 32;
00, and the throttle sensor 98 for detecting the movement of the throttle valve 34 is provided. When the pressure detected by the pressure sensor 100 is equal to or greater than a set value for opening the air bypass valve 114 during deceleration, the throttle valve 34 is closed. When a sudden change occurs, the control means 106 is provided with a function of controlling the opening degree of the control valve 116 to change in the closing direction.

Further, the control means 106 has a set value for opening the air bypass valve 114 at the time of deceleration when the pressure detected by the pressure sensor 100 is a pressure in a predetermined supercharging region where the supercharger 36 is operating. Below, the throttle valve 34
In the case where the control valve 116 suddenly changes in the closing direction, a function of controlling the opening degree of the control valve 116 to change in the closing direction is additionally provided.

More specifically, as shown in FIG. 2, the pressure sensor 100 is provided in the surge tank 28 to detect the internal pressure of the surge tank downstream of the throttle valve 34.

In this embodiment, the control means 106 determines the supercharging pressure PM which is the pressure detected by the pressure sensor 100. That is, the supercharging pressure PM is equal to the set value P
It is determined whether or not the pressure exceeds M (1) (see FIG. 3), and it is also determined whether or not the supercharging pressure PM is within the range between the set PM (2) and the set PM (2a) (see FIG. 3).

The control means 106 confirms that the throttle valve 34 has suddenly changed in the closing direction by judging a change in the throttle opening. This throttle opening change determination is based on the throttle opening change amount ΔTHR (negative value).
Is smaller than the set value DTHR (1), and it is also determined whether the throttle opening change amount ΔTHR (negative value) is smaller than the set value DTHR (2).

Further, the control means 106 also determines a change in the supercharging pressure. This supercharging pressure change determination is based on the supercharging pressure change amount ΔPM
Is smaller than the set value DPM (1), and it is determined whether the supercharging pressure change amount ΔPM is smaller than the set value DPM (2).

Then, the control means 106 determines whether or not the pressure detected by the pressure sensor 100 has decreased to a set value DPM (1) which is a set pressure change amount, and this judgment has been established. Sometimes, the opening of the control valve 116 is changed in the closing direction.

An idle switch 118 for detecting the fully closed state of the throttle valve 34 is provided. When the throttle valve 34 is fully closed, the control means 106 drives the control valve 116 to the fully closed state for a predetermined time. When the throttle valve 34 is not fully closed, the control valve 116 is also driven to a predetermined opening degree for a predetermined time, and has a function of opening the control valve 116 when a control condition is not satisfied during the predetermined time.

Here, the control region of the supercharging pressure PM will be described. As shown in FIG. 4, the region of the control (1) is a region defined by the maximum supercharging pressure and the set value PM (1). This region is the same as the condition under which the air bypass valve 114 is opened.

As shown in FIG. 4, the area of the control (2) is an area defined by the set PM (2) and the set PM (2a).

The generated sounds are different between the area of control (1) and the area of control (2). That is, control (1)
The sound to be eliminated in the area of the air bypass valve 1
This is the sound when 14 is opened ("push sound"), that is, the sound when the high-pressure air is released all at once.

The sound to be eliminated in the region of the control (2) is a sound generated when the condition for opening the air bypass valve 114 is not satisfied by slowly decelerating from the supercharging region ("surreal sound"). That is, a surge sound in which the supercharger 36 tries to push air further while being filled with high-pressure air. This surge noise is caused by the fact that the air bypass valve 114 is closed early because the pursuit noise is a concern.

If the noise reduction by the control valve 116 can be performed efficiently, the area of the control (2) may not be required in some cases.

Next, the operation will be described with reference to the control flowchart of the supercharger noise reduction device of FIG.

When the control program is started and the state is "beginning" (202), a supercharging pressure judgment is carried out, and the supercharging pressure PM, which is the pressure detected by the pressure sensor 100, exceeds the set value PM (1). It is determined whether or not it has been performed (204).

When the determination (204) is YES, the control (1) drive permission flag of the control valve 116 is turned ON (206), and when the determination (204) is NO,
The supercharging pressure is determined, and it is determined whether the supercharging pressure PM is within the range between the set PM (2) and the set PM (2a) (208).
Move to

After the control of the control valve 116 (1) the process of turning on the drive permission flag (206), a throttle opening change determination is performed, and the throttle opening change ΔTHR
It is determined whether or not (negative value) is less than the set value DTHR (1) (210) to determine the rapid deceleration state.
If 10) is YES, the supercharging pressure change determination (212)
When the determination (210) is NO, the process returns to the supercharging pressure determination processing (204) described above.

If the determination (212) as to whether the supercharging pressure change amount ΔPM is less than the set value DPM (1) in the supercharging pressure change judgment is YES, the control of the control valve 116 (1). The drive condition satisfaction flag is turned on (214), and if the determination (212) is NO, the process returns to the above-described supercharging pressure determination process (204).

Then, after the control of the control valve 116 (1) the processing of turning on the satisfaction flag of the driving condition (214), the throttle fully closed determination (216) is performed.

The throttle fully closed determination is performed by the idle switch 1 for detecting the fully closed state of the throttle valve 34.
It is determined whether or not 18 is in the ON state (216).

At this time, the idle switch 118 is turned on.
If the determination (216) of the state is YES, the control valve 116 is driven to the fully closed state (218), and if the determination (216) is NO, the control valve 116 is moved to the set opening v. The control valve 116 is driven up to (1) (220), and after the driving process (218) and (220) of the control valve 116, it is determined whether the ON state of the satisfaction flag of the driving condition of the control valve 116 is continued (222). Move to

Further, the above-described supercharging pressure judgment is performed, and in the judgment (208) as to whether or not the supercharging pressure PM is within the range between the set PM (2) and the set PM (2a), this judgment (20)
If 8) is YES, the control (2) drive permission flag of the control valve 116 is turned ON (224), and if the determination (208) is NO, the above-described supercharging pressure determination processing (204) is performed. Return.

Then, after the control (2) of the control valve 116 and the process (224) of turning on the drive permission flag, a throttle opening change determination is carried out, and the throttle opening change ΔTH
It is determined whether or not R (negative value) is less than the set value DTHR (2) (226) to determine the slow deceleration state. If this determination (226) is YES, the supercharging pressure change determination (22
The process proceeds to 8), and if the determination (226) is NO, the process returns to the above-described boost pressure determination process (204).

If the determination (228) as to whether the supercharging pressure change amount ΔPM in the supercharging pressure change judgment is smaller than the set value DPM (2) is YES, the control of the control valve 116 (2). The drive condition satisfaction flag is turned ON (230), and if the determination (228) is NO, the process returns to the above-described supercharging pressure determination process (204).

Then, after the control of the control valve 116 (2) the process of turning on the drive condition satisfaction flag (230), the control valve 116 is driven to the set opening degree v (2) (232).
After the driving process (232) of the control valve 116, the process proceeds to a determination (222) as to whether or not the ON state of the above-described driving condition satisfaction flag of the control valve 116 is continued.

In the determination (222) of whether or not the ON state of the drive condition satisfaction flag of the control valve 116 is continued, if the determination (222) is YES, the control condition (vehicle driving state) The drive of the control valve 116 is continued for a predetermined period of time (switching between the set times t1 and t2 depending on the control condition) (234), and the control valve 116 is set to the fully open state (236), and the control program ends.
The process proceeds to (238), and if the determination (222) is YES, the control valve 116 is set to the fully open state (236), and the process proceeds to "end" (238) of the control program.

Next, the time chart of FIG. 3 will be described. Note that the numbers in <> correspond to the numbers 1 to 9 described in the operation of the throttle valve in FIG.

First, the operation is started in <1>, and in <2>, the engine is fully opened and the intake pressure condition of the control (1) of the control valve 116 is satisfied.

Then, as shown in <3>, when decelerating with the throttle fully closed, the control valve 116 is fully closed according to the control (1), and is fully opened after a certain set time t1.

After setting <4> by running at a constant speed,
As shown in <5>, when the vehicle slowly accelerates and the control (1) condition is satisfied, the control valve 116 is provided in the control (1) because the throttle opening is not fully closed as shown in <6>. It is driven and held to the set opening (v1). here,
Although the intake pressure changes, the control valve 11
6 is held for t1 after first satisfying the condition, and becomes fully open.

Further, after setting <7> by constant speed running,
As shown in <8>, when the condition of the control (2) is satisfied and the condition of the control (2) is satisfied, the control (2) sets the closing duration of the control valve 116 to t2, the set opening to v2, and a value different from the control (1). Is set.

Thereafter, as shown in <9>, when the vehicle is accelerated and decelerated after satisfying the condition of the control (1), the drive of the control valve 116 is controlled by the control (1). Accelerated before elapse, the control valve 11
6 is immediately in the fully opened state.

Accordingly, when the pressure detected by the pressure sensor 100 is equal to or higher than the set value for opening the air bypass valve 114 during deceleration and the throttle valve 34 suddenly changes in the closing direction, the opening of the control valve 116 is closed. The high-pressure air passes through the bypass passage 112 by the control means 106 having the function of controlling the change in the
This makes it possible to reliably prevent the sound from being released when the air is immediately opened to the intake passage 32 on the upstream side, which is practically advantageous.

The control means 106 sets the pressure detected by the pressure sensor 100 at a pressure in a predetermined supercharging range in which the supercharger 36 is operating, and a set value for opening the air bypass valve 114 at the time of deceleration. Below, the throttle valve 34
When the valve suddenly changes in the closing direction, a function for controlling the opening of the control valve 116 to change in the closing direction is also provided, so that a surge noise (when air is further supplied to high-pressure air). In addition, it is possible to reliably prevent the emission of the sound generated by the supercharger 36).

Further, in order to detect the internal pressure of the surge tank downstream of the throttle valve 34, the surge tank 2
By providing the pressure sensor 100 in FIG. 8, it is possible to use an existing pressure sensor that indirectly measures the amount of intake air used for controlling the internal combustion engine such as control of fuel injection. No special provision is required, the number of parts does not increase, the cost can be kept low, and it is economically advantageous.

Further, when the pressure detected by the pressure sensor 100 falls below a set value DPM (1), which is a set pressure change amount, the control means changes the opening of the control valve 116 in the closing direction. The control by the control 106 allows not only a change in the throttle opening but also a change in the pressure downstream of the throttle valve to be the control condition, and a change in the opening of the throttle valve can be detected more. From the change, it is possible to estimate a change in pressure in the intake passage between the turbocharger and the throttle valve, and it is possible to detect a condition under which an unpleasant sound is generated. For reference, the change in the opening of the throttle valve and the change in the intake pressure do not always match, and the change in the intake cannot be accurately grasped from the change in the opening of the throttle valve.

When the throttle valve 34 is fully closed, the control valve 116 is driven to a fully closed state for a predetermined time, and when the throttle valve 34 is not fully closed, the control valve 116 is driven to a predetermined opening for a predetermined time. In order to open the control valve 116 when the control condition is not satisfied during a predetermined time, the control means 1
06, the throttle valve 3
4 is fully closed, the amount of intake air is small.
No malfunction occurs even if the control valve 116 is driven to the fully closed state for a predetermined time, and the control valve 116 is fully closed for a predetermined time, thereby preventing sound emission. However, when the throttle valve 34 is not fully closed, the intake air amount must be secured, and the control valve 116
Is not fully closed, the control valve 116 is driven for a predetermined time and a predetermined opening to prevent the emission of sound while securing the intake air amount. Since the control valve 116 is opened even if the control condition is not satisfied even during the predetermined time, the control valve 116 does not adversely affect the operation of the internal combustion engine.

It should be noted that the present invention is not limited to the above-described embodiment, and various application modifications are possible.

For example, in the embodiment of the present invention, various kinds of control such as a supercharging pressure judgment, a throttle opening change judgment, and a supercharging pressure change judgment are performed, but other detection values are controlled. It is also possible to adopt a special configuration adopted in the first embodiment.

Then, the vehicle speed and the amount of change in the vehicle speed can be used for the determination, and more accurate control can be achieved by incorporating the running state of the vehicle into the determination.

In the embodiment of the present invention, when the throttle valve suddenly changes in the closing direction, control means for controlling the opening of the control valve in the closing direction is provided, and the high-pressure air flows through the bypass passage. As a result, the sound of a sudden opening to the intake passage on the upstream side of the turbocharger, or a surge sound (when trying to send more air to high-pressure air,
To prevent the release of the sound generated by the turbocharger)
When the above conditions are satisfied, a special configuration in which a part of the supercharging pressure is caused to flow to the exhaust side is also possible.

That is, a relief passage is provided to connect the intake passage upstream of the compressor of the supercharger and the exhaust passage downstream of the turbine of the supercharger, and an on-off valve is provided in the middle of the relief passage. When the above conditions are satisfied, the control means opens the on-off valve and allows a part of the supercharging pressure to flow to the exhaust side.

In this case, a sound is emitted when the air is suddenly opened to the intake passage on the upstream side of the supercharger, or a surge sound (when the supercharger is generated in an attempt to send more air into the high-pressure air). Emission) can be reduced,
It is practically advantageous.

[0067]

As described above in detail, according to the present invention, in an internal combustion engine having a supercharger between an air cleaner in an intake passage and a throttle valve, an upstream side and a downstream side of the supercharger in the intake passage. A bypass passage communicating with the intake passage is provided, and an air bypass valve for opening and closing the bypass passage is provided in the middle of the bypass passage. A control valve for opening and closing the intake valve, a pressure sensor for detecting the pressure of the intake air downstream of the supercharger in the intake passage, a throttle sensor for detecting the movement of the throttle valve, and a pressure detected by the pressure sensor are provided. When the throttle valve suddenly changes in the closing direction when the air bypass valve opens at deceleration or higher, the opening of the control valve is changed to the closing direction. Since the control means provided for, high pressure air passes through the bypass passage can be reliably prevents release sound when once is opened into the intake passage upstream of the supercharger,
It is practically advantageous.

Also, in an internal combustion engine having a supercharger between an air cleaner and a throttle valve in an intake passage, a bypass passage communicating between an upstream side and a downstream side of the supercharger in the intake passage is provided. An air bypass valve that opens and closes the bypass passage is provided on the way, and a control valve that opens and closes the intake passage is provided upstream of the connection between the intake passage and the bypass passage on the upstream side of the turbocharger. A pressure sensor for detecting the pressure of the intake air is provided downstream of the engine, and a throttle sensor for detecting the movement of the throttle valve is provided. The pressure detected by the pressure sensor is a pressure in a supercharging region and the air bypass valve is used at the time of deceleration. When the throttle valve suddenly changes in the closing direction below the set value, the control means is provided to control the opening of the control valve to change in the closing direction. Because, surge sound (to the high pressure of the air,
Sound of the turbocharger trying to blow in more air)
Release can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a control flowchart of a turbocharger noise reduction device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a turbocharger noise reduction device.

FIG. 3 is a time chart of a turbocharger noise reduction device.

FIG. 4 is a diagram showing a control region of a supercharging pressure.

[Explanation of symbols]

2 Internal combustion engine 22 Air cleaner 24 Intake pipe 26 Throttle body 28 Surge tank 30 Intake manifold 32 Intake passage 34 Throttle valve 36 Supercharger (also referred to as “turbocharger”) 40 Intercooler 42 Exhaust manifold 44 Exhaust pipe 46 Catalyst converter 48 Exhaust passage 54 Wastegate passage 56 wastegate valve 58 PCV valve 64 fuel injection valve (also called “injector”) 68 fuel tank 74 pressure regulator 80 canister 86 bypass passage 88 bypass air amount control valve (also called “ISC valve”) 90 ignition coil 92 Crank angle sensor 94 Intake air temperature sensor 96 Water temperature sensor 98 Throttle sensor 100 Pressure sensor 102 O2 sensor 104 Noise reduction device 106 Control means (" CM "and also referred to) 108 also referred to as a battery 110 knock sensor 112 bypass passage 114 air bypass valve (" ABV ") 116 control valve (also referred to as" NR valve "or" noise reduction valve ") 118 idle switch

Claims (5)

[Claims] In an internal combustion engine provided with a supercharger between an air cleaner and a throttle valve in an intake passage, a bypass passage communicating between an upstream side and a downstream side of the supercharger in the intake passage is provided. An air bypass valve that opens and closes a bypass passage is provided on the way, and a control valve that opens and closes an intake passage at a portion upstream of a connection portion between the intake passage and the bypass passage upstream of the turbocharger is provided. A pressure sensor for detecting the pressure of the intake air is provided downstream of the turbocharger, a throttle sensor for detecting the movement of the throttle valve is provided, and the pressure detected by the pressure sensor is set to open the air bypass valve during deceleration. If the throttle valve suddenly changes in the closing direction at a value greater than or equal to the value, control means for controlling the opening degree of the control valve in the closing direction is provided. A noise reduction device for a turbocharger. 2. An internal combustion engine in which a supercharger is provided between an air cleaner in an intake passage and a throttle valve, a bypass passage communicating between an upstream side and a downstream side of the supercharger in the intake passage is provided. An air bypass valve that opens and closes a bypass passage is provided on the way, and a control valve that opens and closes an intake passage at a portion upstream of a connection portion between the intake passage and the bypass passage upstream of the turbocharger is provided. A pressure sensor for detecting the pressure of the intake air is provided downstream of the turbocharger, a throttle sensor for detecting the movement of the throttle valve is provided, and the pressure detected by the pressure sensor is a pressure in a supercharging region and decelerated. When the throttle valve suddenly changes in the closing direction below the set value for opening the air bypass valve, control is performed to change the opening of the control valve in the closing direction. A noise reduction device for a turbocharger, comprising a control means. 3. The turbocharger noise reduction device according to claim 1, wherein the pressure sensor detects a surge tank internal pressure downstream of a throttle valve. 4. The supercharger noise reduction device according to claim 3, wherein when the pressure detected by the pressure sensor drops below a set pressure change amount, the opening degree of the control valve is changed to the closing direction. 5. An idle switch for detecting a fully closed state of a throttle valve is provided, wherein the control means drives the control valve to a fully closed state for a predetermined time when the throttle valve is fully closed, and the throttle valve is not fully closed. 3. The noise reduction device for a turbocharger according to claim 1, further comprising a function of driving the control valve to a predetermined opening for a predetermined time and opening the control valve during a predetermined time when a control condition is not satisfied.