JP3573037B2 - Sound vibration control device for variable valve engine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technology for suppressing noise and vibration generated in a variable valve engine having an intake valve and an exhaust valve (hereinafter, referred to as an intake / exhaust valve) which can be variably controlled at an arbitrary opening / closing timing such as an electromagnetic drive type.
[0002]
[Prior art]
Conventional general engines control the intake air amount by the opening degree of a throttle valve.In recent years, however, an electromagnetically driven intake / exhaust valve is provided, and the intake air amount is controlled mainly by controlling the opening / closing timing of the intake valve. The following has been proposed (see JP-A-8-2000025).
[0003]
[Problems to be solved by the invention]
In the case of this type of intake / exhaust valve, the intake / exhaust valve opens and closes instantaneously, so that the communication opening area of the intake / exhaust system during valve overlap is large, and depending on the opening / closing timing of the intake / exhaust valve, When the gas or flame blows back to the intake system, the noise or vibration level of the intake system may increase, resulting in loud noise inside or outside the vehicle interior or deterioration of parts around the intake system. There is.
[0004]
The present invention has been made in view of such conventional problems, and when the sound and vibration of the engine is abnormal, it is possible to suppress the progress of deterioration of the intake system peripheral parts while suppressing the sound and vibration. It is an object of the present invention to provide a sound vibration control device for a variable valve engine.
[0005]
[Means for Solving the Problems]
Therefore, the invention according to claim 1 is, as shown in FIG.
In a variable valve engine with intake and exhaust valves that can be variably controlled at any opening and closing timing,
A sound / vibration detecting means provided in an intake passage downstream of a throttle valve whose opening is electronically controlled to detect a sound / vibration state of an engine intake system;
An abnormal level sound / vibration detecting means for detecting whether an abnormal level of sound / vibration is generated based on a detection signal of the sound / vibration detecting means,
When it is detected that the abnormal level of sound / vibration is being generated , the opening / closing timing of the intake / exhaust valve is adjusted by controlling the throttle valve so as to maintain a constant torque while controlling the throttle valve . Sound vibration suppression means for lowering the level,
Is characterized by comprising.
[0006]
According to the first aspect of the invention,
When it is detected that the sound and vibration of the engine intake system is at an abnormal level, the electronically controlled throttle valve is throttle-controlled to return gas to the intake system during the valve overlap period of the intake and exhaust valves and to control the electric current. Sound leakage to the upstream side of the throttle valve can be suppressed, and noise and vibration inside and outside the vehicle can be reduced. Further, by adjusting the opening / closing timing of the intake / exhaust valves, it is possible to prevent a decrease in torque due to the throttle control of the electronically controlled throttle valve and to keep the torque constant.
[0007]
The invention according to claim 2 is
The intake valve is normally controlled to close earlier than the intake bottom dead center, and when it is detected that the abnormal level of noise and vibration is generated, the intake valve closing timing is delayed to make the intake bottom dead center It is characterized in that control is performed by performing close control in the vicinity.
[0008]
According to the invention according to claim 2,
The torque can be kept constant by decreasing the torque due to the throttle control of the throttle valve and increasing the torque by delaying the closing timing of the intake valve in the early closing control.
[0009]
The invention according to claim 3 is:
The intake valve is normally controlled to be closed later than the intake bottom dead center, and when it is detected that the abnormal level of sound / vibration is generated, the late closing control is stopped and the intake bottom dead center is detected. The adjustment is performed by performing close control with.
[0010]
According to the invention according to claim 3,
When it is detected that abnormal levels of noise and vibration are being generated, the air that flows into the cylinder from the intake port and the air that is compressed and discharged from the cylinder collide with the late closing control, causing loud noise and vibration. Is prevented by stopping the late closing control, so that noise and vibration inside and outside the vehicle cabin can be reduced .
The invention according to claim 4 is
In a variable valve engine with intake and exhaust valves that can be variably controlled at any opening and closing timing,
A sound / vibration detecting means provided in an intake passage downstream of a throttle valve whose opening is electronically controlled to detect a sound / vibration state of an engine intake system;
An abnormal level sound / vibration detecting means for detecting whether an abnormal level of sound / vibration is generated based on a detection signal of the sound / vibration detecting means,
The intake valve is normally controlled to close earlier than the intake bottom dead center, and when it is detected that the abnormal level of noise and vibration is generated, the intake valve is closed later than the intake bottom dead center. Sound vibration suppression means for switching to control that closes earlier than the intake bottom dead center while maintaining the torque constant, and lowering the level of sound and vibration,
Is characterized by comprising.
[0011]
According to the invention of claim 4,
By switching the intake valve from the late closing control to the early closing control, noise and vibration inside and outside the vehicle cabin due to the late closing control can be reduced, and the torque can be kept constant.
The invention according to claim 5 is
The sound vibration suppression means is configured to, when it is detected that an abnormal level of sound or vibration is generated, reduce the amount of overlap between the intake and exhaust valves to zero and maintain the torque at a constant level so as to maintain the torque constant. It is characterized in that the closing timing of is controlled.
[0012]
According to the invention according to claim 5 ,
When it is detected that abnormal levels of noise and vibration are generated, the opening degree of the communication between the intake system and the exhaust system is reduced by reducing the overlap amount of the intake and exhaust valves to zero, and the exhaust system is closed. Since the backflow of gas to the intake system can be suppressed, the sound and vibration levels can be reduced. Further, by adjusting the closing timing of the intake valve, it is possible to eliminate a torque change and maintain a constant torque.
[0013]
The invention according to claim 6 is
In an area other than the sound / vibration level area where the abnormal level sound / vibration detecting means detects that an abnormal level of sound / vibration is generated, the afterburning phenomenon occurs based on the detection signal from the sound / vibration detecting means. When detecting the occurrence, the opening / closing timing of the intake / exhaust valve is adjusted by controlling the throttle valve with a throttle amount larger than that at the time of occurrence of the abnormal level of sound / vibration so as to maintain a constant torque. It is characterized by suppressing the afterburning phenomenon .
[0016]
According to the invention according to claim 6,
When it is detected that the afterburning phenomenon has occurred, by controlling the throttle of the electronically controlled throttle valve, turbulence occurs in the intake airflow in the intake passage and the intake flow velocity is increased, thereby improving the combustibility and improving the afterburning. The occurrence of the phenomenon is suppressed, and sound leakage to the upstream side of the electronically controlled throttle valve can be suppressed, noise and vibration inside and outside the vehicle cabin can be reduced, and deterioration of parts around the intake system can be suppressed.
[0017]
The invention according to claim 7 is
In an area other than the sound / vibration level area where the abnormal level sound / vibration detecting means detects that an abnormal level of sound / vibration is generated, the afterburning phenomenon occurs based on the detection signal from the sound / vibration detecting means. When the occurrence is detected, the ignition timing is controlled so as to approach an MBT (optimal ignition timing) at which the generated torque becomes maximum.
[0018]
According to the invention according to claim 7,
When it is detected that the afterburning phenomenon has occurred, by bringing the ignition timing close to the MBT, the combustion speed is increased and the flammability is improved. Noise and vibration can be reduced, and deterioration of parts around the intake system can be suppressed.
[0019]
The invention according to claim 8 is
In an area other than the sound / vibration level area where the abnormal level sound / vibration detecting means detects that an abnormal level of sound / vibration is generated, the afterburning phenomenon occurs based on the detection signal from the sound / vibration detecting means. When the occurrence is detected, the mixture ratio of fuel and air is adjusted to a mixture ratio at which the output increases.
[0020]
According to the invention according to claim 8,
When it is detected that the afterburning phenomenon has occurred, by adjusting the mixing ratio of fuel and air to a mixing ratio at which the output increases, the combustion speed increases and the combustibility is improved. Occurrence is suppressed, so that noise and vibration inside and outside the vehicle cabin can be reduced, and deterioration of parts around the intake system can be suppressed.
[0021]
The invention according to claim 9 is
Based on the detection signal from the sound / vibration detecting means, in a region other than the region where it is detected that the abnormal level of sound / vibration is generated, and in a region other than the region where the afterburning phenomenon is occurring. When the occurrence of a fire is detected, the throttle valve is fully closed.
[0024]
According to the invention according to claim 9 ,
When the occurrence of backfire is detected, the electronically controlled throttle valve is fully closed to prevent the backflow of the flame to the intake system, thereby suppressing the backfire. Noise and vibration can be reduced, and deterioration of peripheral parts of the intake system can be suppressed.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 2 is a system diagram of a variable valve engine showing one embodiment of the present invention.
[0026]
A combustion chamber 3 defined by a piston 2 of each cylinder of the engine 1 is provided with an electromagnetically driven intake valve 5 and an exhaust valve 6 so as to surround an ignition plug 4. The intake passage 7 is provided with an electronically controlled throttle valve 8 whose opening is electronically controlled, and an air cleaner 9 is mounted at the upstream end. A vibration sensor 10 as sound / vibration detecting means for detecting a sound / vibration state generated from the intake system of the engine 1 is mounted in the intake passage 7 downstream of the electronically controlled throttle valve 8. Reference numeral 11 denotes an exhaust passage.
[0027]
FIG. 3 shows a basic structure of an electromagnetic drive device for the intake valve 5 and the exhaust valve 6. A plate-shaped mover 22 is attached to a valve shaft 21 of the valve body 20, and the mover 22 is urged to a neutral position by springs 23 and 24. The valve opening electromagnetic coil 25 is disposed below the movable element 22, and the valve closing electromagnetic coil 26 is disposed above the movable element 22.
[0028]
Therefore, when the valve is opened, the power supply to the upper valve closing electromagnetic coil 26 is stopped, and then the current is supplied to the lower valve opening electromagnetic coil 25 to attract the movable element 22 to the lower side. The valve body 20 is lifted to open the valve. Conversely, when closing the valve, the power supply to the lower valve-opening electromagnetic coil 25 is stopped, and then the current is supplied to the upper valve-closing electromagnetic coil 26 to attract the mover 22 upward. The valve body 20 is seated on the seat and closed.
[0029]
Further, a detection rod 31 is engaged with an upper end of the valve shaft 21 of the intake valve 5 and the exhaust valve 6, and a lift sensor 32 is disposed at an upper end of the housing. The lift sensor 32 detects the amount of movement of the detection rod as the amount of lift of the valve body 20. In addition, a contactless distance measuring sensor using infrared rays, ultrasonic waves, or the like can be used as the lift sensor.
[0030]
Returning to FIG. 2, an electromagnetic fuel injection valve 12 is provided in the intake passage 7 at an intake port portion for each cylinder.
Here, the operations of the intake valve 5, the exhaust valve 6, the fuel injection valve 9 and the ignition plug 4 are controlled by a control unit 13, which outputs a crank angle signal in synchronization with the engine rotation. In addition to the crank angle sensor 14 that can detect the engine rotation speed, the accelerator pedal sensor 15 that detects the accelerator opening (the amount of depression of the accelerator pedal), the lift sensor 32 that detects the opening / closing timing of the intake valve 5 and the exhaust valve 6 And so on, a signal is input.
[0031]
Then, the target opening / closing timing of the intake valve 5 and the exhaust valve 6 set based on the operating conditions of the engine is compared with the actual opening / closing timing detected by the lift sensor 32, and the ignition timing is determined based on the deviation. The fuel injection amount and the opening / closing timing of the intake valve 5 and the exhaust valve 6 are adjusted. Also, based on the sound / vibration state signal detected by the vibration sensor 10, an abnormal level of sound / vibration, afterburning phenomenon (afterburning; a phenomenon in which combustion continues until the beginning of the exhaust stroke), and whether or not backfire has occurred And when each abnormal state is detected, fail-safe control for suppressing these abnormal states is performed.
[0032]
Hereinafter, detection of each abnormal state and fail-safe control will be described in detail with reference to a flowchart.
FIG. 4 is a flowchart showing detection of abnormal level sound / vibration and fail-safe control.
[0033]
In step 1, it is determined based on the sound / vibration state detection signal from the vibration sensor 10 whether an abnormal level of sound / vibration is generated. More specifically, as shown in FIG. 5, the determination is made based on whether or not the sound level belongs to an abnormal level area determined by the sound vibration level (dB) and the frequency (KHz). Therefore, the vibration sensor 10 and the function of step 1 constitute an abnormal level sound / vibration detecting means.
[0034]
If it is determined in step 1 that an abnormal level of sound / vibration has been generated, the process proceeds to step 2 and control for reducing the level of the sound / vibration is performed. Specifically, the following control is performed.
[0035]
As a first method, the throttle control of the electronically controlled throttle valve 9 is controlled. As shown in FIG. 6, the throttle amount of the electronically controlled throttle valve 9 is set when an abnormal level of sound or vibration occurs. In this way, by controlling the throttle of the electronically controlled throttle valve 9, it is possible to suppress the backflow of gas to the intake system and the sound leakage to the upstream side of the electronically controlled throttle valve 9 during the valve overlap period of the intake and exhaust valves, Noise and vibration inside and outside the vehicle can be reduced. Further, when the electronically controlled throttle valve 9 is throttled, the torque decreases accordingly, so that the opening / closing timing of the intake and exhaust valves is adjusted so as to maintain the torque constant. Specifically, when controlling the intake air amount by closing the intake valve 5 earlier than the intake bottom dead center, the closing timing of the intake valve 5 is adjusted to be delayed.
[0036]
As a second method, when the late closing control for controlling the intake air amount by closing the intake valve 5 later than the intake bottom dead center is performed, the late closing control is stopped. That is, when the late closing control is performed, the air flowing into the cylinder from the intake port collides with the compressed air discharged from the cylinder, thereby generating loud noise and vibration. By stopping the closing control to prevent generation of sound and vibration, noise and vibration inside and outside the vehicle cabin can be reduced. When the late closing control is stopped and the intake valve 5 is closed near the intake bottom dead center, the torque increases with an increase in the amount of intake air. The throttle control of the valve 9 is performed. Noise and vibration can also be reduced by this aperture control. Alternatively, the late closing control may be stopped, and the intake valve 5 may be closed earlier than the intake bottom dead center to switch to the early closing control in which the intake air amount is controlled.
[0037]
As a third method, control is performed so that the valve overlap amount of the intake and exhaust valves approaches zero. By doing so, the communication opening degree between the intake system and the exhaust system is reduced, and the backflow of gas from the exhaust system to the intake system can be suppressed, so that the sound / vibration level can be reduced. Also in this case, the closing timing of the intake valve 5 is adjusted so as to maintain the torque constant without the torque change due to the control.
[0038]
As a fourth method, control is performed such that the valve overlap position (center position) of the intake / exhaust valve approaches the vicinity of the intake top dead center. With this configuration, when the piston is near the top dead center, the piston speed is close to 0, so that the amount of gas blown back from the cylinder to the intake system during the valve overlap can be sufficiently reduced. Sound and vibration levels can be reduced.
[0039]
Further, the first method, the third method, and the fourth method can be applied in combination of two or more of them. That is, two or more of the throttle control of the electronically controlled throttle valve 9, the control of approaching the overlap amount of the intake and exhaust valves to 0, and the control of approaching the overlap position to the top dead center are combined to achieve sufficient sound and noise. The vibration level can be reduced.
[0040]
If the determination in step 1 is NO, the process proceeds to step 3 and determines whether or not the afterburning phenomenon has occurred based on the sound / vibration state detection signal from the vibration sensor 10. Specifically, as shown in FIG. 5, the determination is made based on whether or not the vehicle belongs to the afterburning phenomenon region determined by the sound vibration level (dB) and the frequency (KHz) .
[0041]
If it is determined in step 3 that the afterburning phenomenon has occurred, the process proceeds to step 4 to perform control for suppressing the afterburning phenomenon .
[0042]
As a first method, the throttle control of the electronically controlled throttle valve 9 is controlled. As shown in FIG. 6, the throttle amount of the electronically controlled throttle valve 9 is set to be used when the afterburning phenomenon occurs, and is set to be larger than when the abnormal level of sound or vibration occurs. In this way, by controlling the throttle of the electronically controlled throttle valve 9, turbulence is generated in the intake air flow in the intake passage 7 and the intake air flow velocity is increased, thereby improving the combustibility and suppressing the occurrence of the afterburning phenomenon. In addition, sound leakage to the upstream side of the electronically controlled throttle valve 9 can be suppressed, so that noise and vibration inside and outside the vehicle cabin can be reduced, and deterioration of parts around the intake system can be suppressed. Further, for example, in the early closing control, the closing timing of the intake valve 5 is adjusted so as to suppress the decrease in torque due to the throttle control of the electronically controlled throttle valve 9 and maintain the torque constant.
[0043]
As a second method, the ignition timing is controlled so as to approach MBT (optimum ignition timing). By bringing the ignition timing close to the MBT, the combustion speed is increased and the combustibility is improved, so that the occurrence of the afterburning phenomenon is suppressed, whereby the noise and vibration inside and outside the vehicle cabin can be reduced, and the parts around the intake system can be reduced. Deterioration can be suppressed. In this case, since the generated torque is increased by the control of bringing the ignition timing close to the MBT, the closing timing of the intake valve 5 is adjusted in a direction to suppress the increase in the torque, for example, in the early closing control.
[0044]
As a third method, the mixing ratio of fuel and air is controlled to a higher output mixing ratio at which the output increases. The output mixing ratio control increases the combustion speed and improves the combustibility in the same manner as the ignition timing control, so that the occurrence of the afterburning phenomenon is suppressed, so that the noise and vibration inside and outside the vehicle cabin can be reduced and the intake air can be reduced. Deterioration of system peripheral components can be suppressed. Also in this case, since the generated torque increases, the closing timing of the intake valve 5 is adjusted earlier in the direction to suppress the increase in the torque, for example, in the early closing control.
[0045]
If the determination in step 3 is NO, the process proceeds to step 5 and determines whether or not backfire has occurred based on the sound / vibration state detection signal from the vibration sensor 10. Specifically, as shown in FIG. 5, the determination is made based on whether or not it belongs to a backfire area determined by the sound vibration level (dB) and the frequency (KHz) .
[0046]
If it is determined in step S5 that backfire has occurred, the process proceeds to step S6 to perform control for suppressing the backfire. Specifically, control for fully closing the electronically controlled throttle valve 9 is performed.
[0047]
As described above, by fully closing the electronically controlled throttle valve 9, the backflow of the flame to the intake system can be blocked and the backfire can be suppressed, thereby reducing noise and vibration inside and outside the vehicle interior. It is possible to suppress deterioration of peripheral components of the intake system.
[0048]
If it is determined in step 5 that backfire has not occurred, it is determined that no abnormality has occurred, and the process proceeds to step 7 to execute normal control.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing a configuration of the present invention.
FIG. 2 is a system diagram of a variable valve engine showing one embodiment of the present invention.
FIG. 3 is a basic structural diagram of an electromagnetic drive device of the intake and exhaust valves.
FIG. 4 is a flowchart of a control routine according to one embodiment.
FIG. 5 is a diagram illustrating a relationship between a sound vibration level and a frequency.
FIG. 6 is a diagram showing a fail-safe opening of an electronically controlled throttle valve in each abnormal state of an engine intake system.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 engine 2 piston 3 combustion chamber 4 ignition plug 5 electromagnetically driven intake valve 6 electromagnetically driven exhaust valve 7 intake passage 8 electronically controlled throttle valve 10 vibration sensor 11 exhaust passage 13 control unit

Claims (9)

In a variable valve engine with intake and exhaust valves that can be variably controlled at any opening and closing timing,
A sound / vibration detecting means provided in the intake passage downstream of the throttle valve whose opening is electronically controlled to detect a sound / vibration state of the engine intake system;
An abnormal level sound / vibration detecting means for detecting whether an abnormal level of sound / vibration is generated based on a detection signal of the sound / vibration detecting means,
When it is detected that the abnormal level of sound / vibration is being generated , the opening / closing timing of the intake / exhaust valve is adjusted by controlling the throttle valve so as to maintain a constant torque while controlling the throttle valve . Sound vibration suppression means for lowering the level,
A sound vibration control device for a variable valve engine, comprising: The intake valve is normally controlled to close earlier than the intake bottom dead center, and when it is detected that the abnormal level of noise and vibration is generated, the intake valve closing timing is delayed to reduce the intake bottom dead center. The sound vibration control device for a variable valve engine according to claim 1, wherein the control is performed by performing close control in the vicinity. The intake valve is normally controlled to close later than the intake bottom dead center, and when it is detected that the abnormal level of sound and vibration is generated, the late closing control is stopped and the intake bottom dead center is detected. The sound vibration control device for a variable valve engine according to claim 1, wherein the control is performed by performing close control. In a variable valve engine with intake and exhaust valves that can be variably controlled at any opening and closing timing,
A sound / vibration detecting means provided in the intake passage downstream of the throttle valve whose opening is electronically controlled to detect a sound / vibration state of the engine intake system;
An abnormal level sound / vibration detecting means for detecting whether an abnormal level of sound / vibration is generated based on a detection signal of the sound / vibration detecting means,
The intake valve is controlled to normally close earlier than the intake bottom dead center, and when it is detected that the abnormal level of noise and vibration is generated, the intake valve is closed later than the intake bottom dead center. A vibration suppression means for switching to a control that closes earlier than the intake bottom dead center while maintaining a constant torque to reduce the level of sound and vibration,
A sound vibration control device for a variable valve engine, comprising: The sound vibration suppression means is configured to, when it is detected that an abnormal level of sound or vibration is generated, reduce the amount of overlap between the intake and exhaust valves to zero and maintain the torque at a constant level so as to maintain the torque constant. The sound vibration control device for a variable valve engine according to any one of claims 1 to 4, wherein the closing timing of the variable valve engine is controlled. In an area other than the sound / vibration level area where the abnormal level sound / vibration detecting means detects that an abnormal level of sound / vibration is generated, the afterburning phenomenon occurs based on the detection signal from the sound / vibration detecting means. When detecting the occurrence, the opening / closing timing of the intake / exhaust valve is adjusted by controlling the throttle valve with a throttle amount larger than that at the time of occurrence of the abnormal level of sound / vibration so as to maintain a constant torque. The sound vibration control device for a variable valve engine according to any one of claims 1 to 5, wherein a afterburning phenomenon is suppressed . In an area other than the sound / vibration level area where the abnormal level sound / vibration detecting means detects that an abnormal level of sound / vibration is generated, the afterburning phenomenon occurs based on the detection signal from the sound / vibration detecting means. 6. The variable operation according to claim 1 , wherein when the occurrence is detected, the ignition timing is controlled so as to approach an MBT (optimal ignition timing) at which the generated torque becomes maximum. Sound vibration control device for valve engine. In an area other than the sound / vibration level area where the abnormal level sound / vibration detecting means detects that an abnormal level of sound / vibration is generated, the afterburning phenomenon occurs based on the detection signal from the sound / vibration detecting means. The variable valve engine according to any one of claims 1 to 5, wherein when the occurrence is detected, the mixing ratio of fuel and air is adjusted to a mixing ratio at which the output increases. Sound and vibration control device. The sound / vibration detecting means in a region other than the sound / vibration level region where it is detected that the abnormal level of sound / vibration is generated, and in a region other than the sound / vibration level region where the afterburning phenomenon is occurring; The variable valve engine according to any one of claims 6 to 8, wherein the throttle valve is fully closed when it is detected that a backfire has occurred based on a detection signal from the engine. Sound and vibration control device.

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