JPH0643816B2 - Engine throttle control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an engine throttle valve control device, and more particularly to a supercharging delay in an engine equipped with a turbocharger,
Regarding prevention measures for (turbo lag).

(Prior Art) Conventionally, an accelerator operation amount detecting means for detecting an operation amount of an accelerator and a throttle valve driving means for driving a throttle valve are provided as disclosed in, for example, Japanese Patent Application Laid-Open No. 57-116140. Thus, there is known a throttle valve control device in which the throttle valve is electrically controlled so as to have a predetermined opening characteristic according to the accelerator operation amount.

On the other hand, the engine is equipped with a turbocharger for supercharging intake air, so that when the output is requested during acceleration or the like, the supercharging pressure by the operation of the turbocharger increases the intake charging efficiency to improve the output. It is also known to do.

(Problems to be Solved by the Invention) In an engine equipped with a turbocharger as described above, even if the turbocharger is operated when a supercharge is requested, the supercharge pressure does not immediately increase, so However, there is a problem that the acceleration response is poor due to the delay (turbo lag). The same can be said for a turbocharged engine equipped with the above throttle valve control device.

The present invention has been made in view of the above points, and in a turbocharged engine equipped with a throttle valve control device,
In the region where the turbo lag is generated, the throttle valve opening characteristic is changed, and the throttle valve is opened to increase the intake charge amount. The purpose is to prevent acceleration and improve acceleration response.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the solving means of the present invention includes a turbocharger 14 as shown in FIG. 1, while detecting an accelerator operation amount. The throttle valve 11 receives the outputs of the accelerator operation amount detecting means 30, the throttle valve driving means 13 for driving the throttle valve 11, and the accelerator operation amount detecting means 30, and the throttle valve 11 has a preset opening degree according to the accelerator operation amount. It is premised on an engine throttle valve control device provided with a throttle valve control means 37 for controlling the throttle valve drive means 13 so as to obtain the characteristics. On the other hand, the supercharging area detecting means 35 for detecting the supercharging area,
The supercharging pressure detecting means 31 for detecting the supercharging pressure of the intake air supplied to the engine, the supercharging area detecting means 35, and the outputs of the supercharging pressure detecting means 31 are received, and the supercharging area has a predetermined supercharging pressure. When the value is equal to or less than the value, the throttle valve opening correction means 38 for correcting the throttle valve opening so that the throttle valve opening with respect to the accelerator operation amount is on the open side with respect to the opening characteristic preset by the throttle valve control means 37. It is configured to include and.

(Operation) With this configuration, according to the present invention, the throttle valve opening correction means 38 corrects the throttle valve opening degree in the supercharging region and when the supercharging pressure is equal to or less than the predetermined value, and the throttle valve control means. By opening the throttle valve opening with respect to the accelerator operation amount to the opening side with respect to the opening characteristic set in advance in 37, the intake air charging amount is increased and turbocharging until the supercharging pressure rises to a predetermined value. The decrease in efficiency is compensated, and thus good acceleration response is ensured.

In this case, if the opening characteristic of the throttle valve is set to the opening side in advance in the entire operating region of the engine, the deterioration of the charging efficiency due to the turbo lag can be compensated for as in the present invention, but there is no problem of turbo lag. In the operating region, the change characteristic of the throttle valve opening with respect to the change in the accelerator operation amount becomes too sensitive and the operating state of the engine changes abruptly, deteriorating the drivability. It is preferable to set only the opening side.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings starting from FIG.

FIG. 2 shows an overall schematic configuration of an engine equipped with a throttle valve control device according to an embodiment of the present invention. In the figure,
An engine 1 has a combustion chamber 3 whose volume is variable by a piston 2, and the piston 2 and connecting rod 4 are provided.
The crankshaft 5 is provided as an output shaft connected through the. Reference numeral 6 denotes an intake passage through which one end is opened to the atmosphere through an air cleaner 7 and the other end is opened to the combustion chamber 3 of the engine 1 to supply intake air to the combustion chamber 3.
Of the intake passage 6 and the exhaust passage 8 to the combustion chamber 3, and the other end of the intake passage 6 and the exhaust passage 8 open to the atmosphere. An intake valve 9 and an exhaust valve 10 are provided in each.

The intake passage 6 is provided with a throttle valve 11 for controlling the amount of intake air to the engine 1, and a fuel injection valve 12 for injecting and supplying fuel is provided downstream of the throttle valve 11. The throttle valve 11 includes the throttle valve 11
A throttle actuator 13 including a step motor or the like as a throttle valve driving means for driving the is connected.

Further, 14 is a turbocharger that supercharges intake air to the engine 1, and the turbocharger 14 is a turbine 15 that is provided in the exhaust passage 8 and is rotationally driven by the exhaust gas flow.
The blower 16 is provided upstream of the throttle valve 11 in the intake passage 6 and is connected to the turbine 15 via a connecting shaft 17. The blower 16 driven by the turbine 15 supercharges intake air. ing. still,
Reference numeral 18 is a bypass passage that bypasses the turbine 15 and communicates the exhaust passage 8 upstream and downstream thereof, 19 is a wastegate valve disposed in the bypass passage 18, and the wastegate valve 19 has an intake passage. The diaphragm type actuator 20 that responds to the intake pressure (supercharging pressure) downstream of the blower 16 of No. 6 is connected, and when the supercharging pressure becomes equal to or higher than the set value (maximum supercharging pressure), the operation of the actuator 20 causes the wastegate valve. 19 is opened to allow the exhaust gas to bypass the turbine 15 by the bypass passage 18 and flow down, whereby the rotation of the turbine 15 is reduced and the blower 16 is rotated.
The supercharging pressure due to is reduced, so that the supercharging pressure is maintained at the maximum supercharging pressure.

On the other hand, 30 is an accelerator pedal position sensor as an accelerator operation amount detecting means for detecting the depression amount of the accelerator pedal 21, that is, the accelerator operation amount θ, and 31 is the intake passage 6
A supercharging pressure sensor as a supercharging pressure detecting means for detecting a supercharging pressure P of intake air supplied to the engine 1, and a throttle position 32 for detecting an opening T of the throttle valve 11. It is a sensor. Further, 33 is a crank angle sensor for detecting the engine speed N by the crank angle of the crankshaft 5, 34 is an air flow sensor for detecting the intake air amount Q, and the accelerator pedal position sensor 30 indicates the required load of the engine 1. A supercharging region detecting means for detecting and detecting whether or not it is a supercharging region requiring supercharging of intake air is configured. The outputs of the sensors 30 to 34 are input to a control unit 36 that controls the operation of the fuel injection valve 12 and the throttle actuator 13, and the control unit 36 causes the operating state of the engine 1 (engine speed and engine speed and The fuel injection valve 12 is controlled to inject an amount of fuel according to the engine load), and the engine 1
Feedback control is performed so that the opening degree T of the throttle valve 11 becomes a predetermined opening degree in accordance with the operating state.

Next, the throttle valve opening control by the control unit 36 will be described with reference to the flow chart of FIG. 3. First, in step S ₁ , a signal of the accelerator operation amount θ from the accelerator pedal position sensor 30 and a boost pressure sensor. The signal of the supercharging pressure P is read from 31 respectively, the signal of the engine speed N is read from the crank angle sensor 33 and the signal of the intake air amount Q is read from the air flow sensor 34 in step S ₂ , and then in step S ₃ . The rate of change dθ / dt of the accelerator operation amount θ is calculated.

Then, whether greater than the set value α the rate of change d [theta] / dt of the accelerator operation amount corresponds to rapid acceleration determined in step S _4, the supercharging region is determined whether further step S _5. Then, the determination in step S ₄ is dθ / dt ≦
In the case of NO which is not during the rapid acceleration of α and when the determination in step S ₅ is NO which is not in the supercharging region, it is determined that the engine is in normal operation, and in step S ₆ , the normal operation which is preset according to the accelerator operation amount θ is performed. The throttle valve opening T is calculated based on the opening characteristic fa (θ) for driving, and the control signal is output to the throttle actuator 13 so that the throttle valve 11 becomes the throttle valve opening T in step S _11. .

On the other hand, in the case of YES determination in place in and step S ₅ of YES judgment at the step S ₄ is rapid acceleration of dθ / dt> α is supercharging region, the supercharging pressure further in step S ₇ It is determined whether P is greater than or equal to a predetermined value Pa (maximum boost pressure value). When the determination is NO at P <Pa, the supercharging pressure P is the predetermined value Pa despite the supercharging region requiring supercharging.
It is determined that when the has occurred turbo-lag does not reach, the turbo lag that is set to the open side than the opening degree characteristic time for advance the normal operation in accordance with the accelerator operation amount θ fa ((θ) in step S ₈ The throttle valve opening T is calculated on the basis of the opening characteristic fa (θ) for cancellation, and step S ₁₁ is repeated.
Then, the control signal is output to the throttle actuator 13 so that the throttle valve opening T is achieved.

Then, without throttle valve opening control based on the supercharging pressure P rises and the judgment at the step S ₇ is YES of P ≧ Pa, immediately opening characteristic fa for ordinary operation (theta), The opening control of the throttle valve is performed based on the opening characteristic for transition to prevent torque shock. That is, opening characteristic for at the transition in step _{S 9 fb (θ) o-} fc (t) the throttle valve opening T based on
Is calculated. Here, the fb (θ) o is the throttle valve opening at the beginning of the transition, which is obtained based on the turbo lag elimination opening characteristic fb (θ). And the next step S
_{At 10} , it is determined whether or not the throttle valve opening T is equal to or greater than fa (θ) o (note that fa (θ) o is the opening characteristic for normal operation fa
A throttle valve opening degree at the time of migration completing obtained based on (θ)), T> fa (θ) o between YES, opening characteristic fb (theta for the time the transition in step S ₁₁₎ o- The control signal is output to the throttle actuator 13 so that the throttle valve opening T obtained based on fc (t) is achieved. On the other hand, if the determination in step S ₁₀ is NO at T = fa (θ) o, it is determined that the transition has been completed and step S ₆
Then, the throttle valve opening control is performed based on the normal operation opening characteristic fa (θ).

In the above flow, the throttle actuator 11 (throttle valve drive means) is adjusted so that the throttle valve 11 has the opening characteristic for normal operation fa (θ) preset according to the accelerator operation amount θ in steps S ₆ and S _11. ) For controlling the throttle valve control means 37. Further, in steps S ₄ , S ₅ , S ₇ and S ₈ , when the supercharging pressure P is equal to or lower than the predetermined value in the supercharging region, the throttle valve 11 has the turbo lag elimination opening characteristic fb (θ), That is, a throttle for correcting the throttle valve opening so that the throttle valve opening T with respect to the accelerator operation amount θ is on the open side with respect to the normal operation opening characteristic fa (θ) preset by the throttle valve control means 37. It constitutes the valve opening correction means 38.

Therefore, in the above embodiment, as shown in FIG. 4, even in the supercharging region, in the region I of the turbo lag where the supercharging pressure P is equal to or less than the predetermined value, the throttle valve opening correction means 38 causes the throttle valve opening correction means 38 to The throttle valve opening is corrected by the control means 37 so that the throttle valve opening T with respect to the accelerator operation amount θ is on the open side with respect to the opening characteristic fa (θ) for normal operation set in advance, and the turbo lag is eliminated. Opening characteristic fb
Since the control is performed so as to be (θ), the intake charge amount is increased by the increase in the throttle valve opening degree, and the decrease in the charge efficiency due to the turbo lag is compensated for, and good acceleration response is obtained. Therefore, the acceleration performance and the output performance can be improved.

Then, when the supercharging pressure P rises to a predetermined value Pa (maximum supercharging pressure value) and enters the region II where there is no turbo lag, the throttle valve opening T is the opening characteristic fb (θ) o-fc (t for transition. ), The transition is made to the opening characteristic for normal operation fa (θ), so that the transition can be made smoothly without torque shock. After that, the throttle valve control means 37 controls the throttle valve 11 to the opening characteristic fa (θ) for normal operation preset according to the accelerator operation amount θ.

Further, the setting of the above-mentioned opening characteristic fb (θ) for eliminating the turbo lag, that is, the opening side of the opening characteristic fa (θ) for normal operation is set in the supercharging region and the supercharging pressure P is equal to or less than a predetermined value. Since it is considered in the region I and not in the other regions, it is preferable that the change in the throttle valve opening T with respect to the change in the accelerator operation amount θ becomes sensitive in the other regions without causing a sudden change in the engine operating state. Drivability can be secured.

In an engine equipped with an automatic transmission, when the engine is kicked down, the engine speed rapidly rises. Therefore, the throttle valve opening T with respect to the accelerator operation amount θ is set closer to the closing side than a preset opening characteristic. It is preferable to suppress the increase in engine speed and prevent shift shock.

(Effects of the Invention) As described above, according to the present invention, in the throttle valve control device for the engine with a turbocharger, the throttle valve opening degree is electrically controlled according to the accelerator operation amount. In the charging area, the throttle valve opening is corrected to the open side to increase the intake charge until the turbocharging pressure of the turbocharger rises to a predetermined value, so a simple throttle valve control device is used. With the configuration, it is possible to effectively compensate for the decrease in the filling efficiency due to the turbo lag, ensure a good acceleration response, and improve the acceleration performance and the output performance.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 4 show an embodiment of the present invention, FIG. 2 is an overall schematic configuration diagram thereof, FIG. 3 is a flow chart showing the operation of a control unit, and FIG. 4 is an accelerator operation amount and throttle valve opening degree. It is an explanatory view showing a supercharging pressure change characteristic. 1 ... Engine, 11 ... Throttle valve, 13 ... Throttle actuator, 14 ... Turbocharger, 30 ...
... accelerator pedal position sensor, 31 ... supercharging pressure sensor, 32 ... throttle position sensor, 33 ...
Crank angle sensor, 34 ... Air flow sensor, 36 ...
... control unit, 37 ... throttle valve control means, 38 ... throttle valve opening correction means.

Claims (1)

[Claims] Claim: What is claimed is: 1. A turbocharger, which is provided with an accelerator operation amount detection means for detecting an operation amount of an accelerator, a throttle valve drive means for driving a throttle valve, and an output from the accelerator operation amount detection means. A throttle valve control device for an engine, comprising: a throttle valve control means for controlling the throttle valve drive means so that the valve has a preset opening characteristic according to an accelerator operation amount,
A supercharging region detecting means for detecting a supercharging region, a supercharging pressure detecting means for detecting a supercharging pressure of intake air supplied to the engine, and an output of the supercharging region detecting means and the supercharging pressure detecting means, When the supercharging region is in the supercharging region and the supercharging pressure is equal to or lower than a predetermined value, the throttle valve opening is adjusted so that the throttle valve opening corresponding to the accelerator operation amount is on the open side with respect to the opening characteristic preset by the throttle valve control means. A throttle valve control device for an engine, comprising: a throttle valve opening correction means for correcting.