JP2023182363A - Intake control device of vehicle - Google Patents

Abstract

To provide an intake control device of a vehicle which can predict and adjust a request opening degree of a grille shutter based on driving conditions and load conditions to reduce air resistance of the vehicle when opening and closing the grille shutter, as much as possible.SOLUTION: An intake control device of a vehicle includes: a supercharger which compresses intake air of an engine; an intercooler which cools the intake air compressed by the supercharger through air cooling; and a grille shutter which controls an air quantity of travel wind toward the intercooler. The intake control device includes a controller performing opening and closing control of the grille shutter. The controller predicts temperature of the intake air after passing through the intercooler and prohibits opening of the grille shutter when the predicted temperature of the intake air is a prescribed temperature or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to an air intake control device for a vehicle that includes a grille shutter provided in a grille opening at the front of the vehicle body.

Some recent vehicles are equipped with a grille shutter behind a driving wind inlet such as a front grill. By closing the plurality of fins of the grille shutter to close or opening the traveling wind inlet, the amount of traveling wind introduced into the engine room can be adjusted.

Patent Document 1 discloses a control device for a vehicle grille shutter provided with a grille shutter configured as described above. This control device requests opening of the grill shutter when the temperature of an electronic control unit (hereinafter referred to as ECU) installed in the engine room reaches a higher temperature than a predetermined temperature while the grill shutter is closed. and cools the ECU. According to the invention of Patent Document 1, when the temperature of the ECU becomes high, the grill shutter can be appropriately opened to cool the ECU sufficiently.

Japanese Patent Application Publication No. 2014-148194

In conventional grille shutters that do not have an intermediate opening degree, a temperature sensor is provided in the engine compartment and requires the grille shutter to be fully opened when the temperature exceeds a predetermined level.

Additionally, when driving with the grille shutter closed, the grille shutter prevents outside air from entering the engine compartment and prevents air turbulence within the engine compartment. It is conventionally known to reduce the Cd value, drag coefficient value). Since fuel efficiency is improved by reducing the air resistance of a vehicle, it is required that the grille shutter be kept closed as much as possible.

On the other hand, in engines equipped with a supercharger, the intake air that is pressurized by the supercharger and heated to a high temperature is radiated by an intercooler placed near the front grill, which reduces the thermal expansion of the intake air after supercharging. It is said that it is possible to prevent this and efficiently burn the mixture of fuels. Therefore, in an engine equipped with a supercharger, a request to open the grille shutter is output in order to efficiently dissipate heat and cool the intercooler.

However, since it takes time to open and close the grille shutter, the grille shutter remains open until the intercooler is cooled by the outside air passing through the open grille shutter and the grille shutter is closed when there is no need for further cooling. In this state, due to the delay in opening and closing the grille shutter, the air resistance of the entire vehicle may become greater than when it is in the closed state.

This invention was made with a focus on the above-mentioned technical problem, and the required opening degree of the grille shutter is predicted and adjusted based on driving conditions and load conditions, and the air resistance of the vehicle due to the opening and closing of the grille shutter is minimized. It is an object of the present invention to provide a vehicle intake control device that can reduce the amount of air intake.

In order to achieve the above object, the present invention includes a supercharger that pressurizes the intake air of an engine, an intercooler that air cools the intake air pressurized by the supercharger, and a running air flow rate for the intercooler. An air intake control device for a vehicle, comprising a controller for controlling opening and closing of the grille shutter, the controller predicting the temperature of the intake air after passing through the intercooler, and predicting the temperature of the intake air after passing through the intercooler. If the temperature of the intake air is below a predetermined temperature, opening of the grille shutter is prohibited.

According to the intake air control device for a vehicle of the present invention, the temperature of the intake air after being pressurized by the supercharger and passing through the intercooler is predicted, and if the predicted intake air temperature is below a predetermined temperature, the grille shutter is closed. By prohibiting the opening of the grille shutter, the air resistance of the vehicle caused by opening and closing of the grille shutter can be reduced as much as possible.

Specifically, the system predicts the intake air temperature when the high-temperature intake air is pressurized by the supercharger and passes through the intercooler, and if the predicted intake air temperature is below a predetermined value, the grill By not opening the shutter, the grill shutter can be closed in a timely manner and unnecessary opening of the grill shutter can be prohibited, and when the intake air temperature is below a predetermined value, the grill shutter can be kept closed. can. Therefore, when driving with the grille shutter closed, outside air is not introduced into the engine compartment, preventing air turbulence within the engine compartment, and reducing the overall air resistance of the vehicle. .

FIG. 1 is a schematic diagram for explaining the configuration of an embodiment of the present invention. FIG. 2 is a block diagram for explaining an example of a control device in an embodiment of the invention. 3 is a flowchart for explaining a control example of the vehicle intake control device in Embodiment 1 of the present invention. 7 is a flowchart for explaining a control example of the vehicle intake control device in Embodiment 2 of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An intake control device for a vehicle according to an embodiment of the present invention will be specifically described with reference to the drawings. It should be noted that the embodiments described below are merely examples of implementing the present invention, and are not intended to limit the present invention.

FIG. 1 is a diagram for explaining the configuration of an embodiment of the present invention, and is a diagram schematically showing an engine compartment 1 of a vehicle Ve. Vertical arrows indicate the longitudinal direction of the vehicle, and horizontal arrows indicate the lateral direction of the vehicle.

In the engine room 1, an engine 4 connected between an intake passage 2 and an exhaust passage 3, and a supercharger 5 that generates compressed air introduced into the engine 4 through the intake passage 2 are arranged. The supercharger 5 includes a compressor 6 provided in the intake passage 2 and a turbine 7 provided in the exhaust passage 3. The turbine 7 is driven by the exhaust gas passing through the exhaust passage 3, and the turbine 7 and the compressor 6, which are connected to each other so as to transmit rotational force, compress intake air to generate compressed air.

The intake passage 2 is provided with an air cleaner 8, a compressor 6 of a supercharger 5, an air-cooled intercooler 9, and a throttle valve 10 in this order from upstream. The intake air taken in from an intake port (not shown) passes through the air cleaner 8 and becomes intake air compressed by the compressor 6 (hereinafter sometimes referred to as compressed air). The compressed air, which has been pressurized to a high temperature, is cooled by heat dissipation from the intercooler 9, and the intake air amount is adjusted by the throttle valve 10, and then sent to the cylinder 11 of the engine 4. A post-supercharging pressure sensor 12 that detects the pressure of compressed air after supercharging is provided between the compressor 6 of the supercharger 5 and the intercooler 9. An I/C outlet temperature sensor 13 that detects the temperature of the compressed air that has passed through the intercooler 9 is provided between the two.

In the cylinder 11 of the engine 4, a mixture of compressed air and fuel injected from a fuel injection valve (not shown) is combusted, and exhaust gas after combustion is discharged to the exhaust passage 3.

A turbine 7 of a supercharger 5 is provided in the exhaust passage 3, and the exhaust gas that has passed through the turbine 7 is configured to be sent to a catalytic converter and a muffler (not shown). Note that a bypass passage connecting the upstream and downstream sides of the turbine 7 may be provided, and the supercharging pressure may be adjusted by a wastegate valve provided in the bypass passage.

Next, the grille shutter 14 will be explained. The grille shutter 14 is disposed in an opening 16 formed in the front surface of the body 15 of the vehicle Ve in order to adjust the amount of air flowing to the intercooler 9. The interior of the grille shutter 14 includes a plurality of fin portions 17 capable of shielding the outside air and the running wind W, and a plurality of fin shafts 18 rotatably fixing the fin portions 17. By rotating each fin shaft 18 in the axial direction, each fin part 17 can be tilted in the axial direction, and when the tilt angle of the fin part 17 is parallel to the longitudinal direction of the vehicle, it is "open". On the other hand, when the angle of inclination of the fin portion 17 is perpendicular to the longitudinal direction of the vehicle, it is a "closed state" or a "closed state".

Note that the angle at which the fin portion 17 is inclined refers to the opening degree of the grille shutter, and the fin portion 17 of the embodiment of the present invention is in an “open state” that is parallel to the longitudinal direction of the vehicle, or in an “open state” that is parallel to the longitudinal direction of the vehicle. It is not limited to the "closed state" which is perpendicular to , but an intermediate opening degree that can be set to an appropriate opening degree may be provided. The grill shutter 14 includes a grill shutter actuator (not shown) for driving the fin shaft 18, and the grill shutter opening is detected by a grill shutter opening sensor 19 attached to the grill shutter 14, and the grill shutter opening is requested. is output to the actuator.

As shown in FIG. 1, when the fin portions 17 are parallel to the longitudinal direction of the vehicle, that is, in the open state, the running wind W passes between the fin portions 17 and enters the engine room 1, including the intercooler 9 and other parts. By hitting a cooling device (not shown) or the like, the cooling device radiates heat and is cooled.

Note that the opening/closing mechanism of the grille shutter 14 is not limited to the above-described configuration; for example, the fin shaft 18 may be configured to be parallel to the left-right direction of the vehicle, and the fin portion 17 may be tilted in the axial direction. It's okay. In other words, the configuration may be such that the traveling wind W hits at least the intercooler 9 depending on the opening degree of the grille shutter.

Next, an electronic control unit (ECU) 20 for controlling opening and closing of the grille shutter 14 is provided. This ECU 20 corresponds to the "controller" in the embodiment of the present invention, and is mainly composed of a microcomputer. FIG. 2 is a block diagram for explaining an example of the configuration of the ECU 20. As shown in FIG.

The ECU 20 is configured to receive data from various sensors mounted on the vehicle Ve, and output command signals based on the input data and pre-stored maps, calculation formulas, etc. . An example of data input to the ECU 20 is shown in FIG. 2, including a signal from a vehicle speed sensor that detects the vehicle speed, a signal from a sensor that detects the rotational speed of the engine 4, and an accelerator opening degree that detects the amount of operation of an accelerator pedal (not shown). Sensor signals, signals from sensors that detect outside air temperature, signals from sensors that detect atmospheric pressure, and data from the aforementioned post-supercharging pressure sensor 12, I/C outlet temperature sensor 13, grill shutter opening sensor 19, etc. , is input to the ECU 20.

The ECU 20 shown in FIG. 2 includes at least an intake air amount calculation section 21, a post-supercharging intake air temperature prediction section 22, an I/C heat radiation amount prediction section 23, an I/C outlet temperature prediction section 24, and a grille shutter as a functional configuration. An opening calculation section 25 is provided.

The intake air amount calculating section 21 has a function of calculating the required intake air amount of the engine 4 based on the engine speed and the accelerator opening. Alternatively, it may be determined based on an intake air amount map stored in advance in the ECU 20.

For example, the post-supercharging intake air temperature prediction unit 22 predicts the future intake air temperature after supercharging based on detection signals from an outside air temperature sensor and an atmospheric pressure sensor, and a detection signal from the post-supercharging pressure sensor 12. It has the ability to predict. Note that the future refers to a predetermined period of time later, and the period may be changed as appropriate depending on operating conditions and the like.

For example, the I/C heat dissipation amount prediction unit 23 calculates, based on the required intake air amount determined by the intake air amount calculation unit 21 and the future intake air temperature after supercharging determined by the post-supercharging intake air temperature prediction unit 22. It has a function of predicting the required amount of heat radiation by the intercooler 9 so that the outlet temperature of the intercooler 9 becomes a predetermined target temperature.

For example, the I/C outlet temperature prediction section 24 calculates the amount of heat dissipated by the intercooler 9, which is determined from a heat dissipation map stored in advance in the ECU 20, and the required intake air amount, which is determined by the intake air amount calculation section 21. It has a function of predicting the outlet temperature of the intercooler 9.

The grille shutter opening calculation section 25 calculates the grille shutter opening amount based on the vehicle speed, the required intake air amount determined by the intake air amount calculation section 21, and the required heat radiation amount by the intercooler 9 determined by the I/C heat radiation amount prediction section 23. It has a function to calculate 14 required opening degrees.

Then, a command signal for the grille shutter opening degree is output to the actuator based on data input to the ECU 20 and the like.

The grille shutter 14 prevents outside air from being introduced into the engine compartment 1 and prevents air turbulence in the engine compartment 1 when the vehicle is driven with the grille shutter 14 in the closed state. Air resistance can be reduced. Further, since fuel efficiency is improved by reducing the air resistance of the vehicle Ve, it is preferable to maintain the grille shutter 14 in a closed state.

On the other hand, in the engine 4 equipped with the supercharger 5, the compressed air that has been pressurized by the supercharger 5 and has become high temperature is radiated by the intercooler 9, thereby reducing the thermal expansion of the compressed air after supercharging. Therefore, it is desirable that the grille shutter 14 be in an open state in order for the intercooler 9 to efficiently dissipate heat and cool the compressed air, since the air-fuel mixture containing the fuel can be efficiently combusted.

Furthermore, since it takes time to open and close the grille shutter 14, the intercooler 9 is cooled by the traveling wind W passing through the grille shutter 14 in the open state, and it takes a long time to close the grille shutter 14 when there is no need for further cooling. During this period, the grille shutter 14 is at least in the open state, and the air resistance of the entire vehicle Ve may be increased accordingly compared to when it is in the closed state.

In this way, in order to reduce the air resistance of the entire vehicle Ve as much as possible, the grille shutter 14 is kept closed as much as possible, and when the heat is radiated by the intercooler 9 as predicted from the driving conditions and load situation. In order to open the grille shutter 14 only at certain times, the vehicle air intake control device in the embodiment of the present invention described above is configured to execute the control described below.

3 and 4 are flowcharts for explaining an example of the control, and the control shown in these flowcharts is repeatedly executed by the ECU 20 while the engine 4 is being operated. FIG. 3 is a flowchart for explaining an example of control of the vehicle intake control device according to the first embodiment of the present invention. First, a required intake air amount is calculated (step S1). The required intake air amount is determined by the intake air amount calculation unit 21. Specifically, the required intake air amount of the engine 4 is calculated based on the engine speed and the accelerator opening.

Next, the future intake air temperature after supercharging is predicted (step S2). The future intake air temperature after supercharging is determined by the post-supercharging intake air temperature prediction unit 22. Specifically, the future intake air temperature after supercharging is predicted based on the detection signals from the outside air temperature sensor and the atmospheric pressure sensor, and the detection signal from the post-supercharging pressure sensor 12.

Subsequently, the amount of heat released by the intercooler 9 is predicted from the intake air amount and the estimated intake air temperature after supercharging so that the outlet temperature of the intercooler 9 becomes a predetermined temperature (step S3). This amount of heat radiation is determined by the I/C heat radiation amount prediction unit 23. Specifically, based on the required intake air amount determined in step S1 and the future intake air temperature after supercharging determined in step S2, the outlet temperature of the intercooler 9 is set to a predetermined target temperature. The required amount of heat radiation by the intercooler 9 is predicted.

Subsequently, the required grille shutter opening degree is calculated from the vehicle speed of the vehicle Ve, the calculated value of the required intake air amount obtained above, and the predicted value of the amount of heat dissipated by the intercooler 9 (step S4). The required grille shutter opening degree is determined by the grille shutter opening degree calculation section 25. Then, the grill shutter opening calculated by the grill shutter opening calculation section 25 is requested (step S5). A command signal for the opening degree of the grille shutter is output to the actuator, and the fin shaft 18 is driven to tilt the fin portion 17 to a predetermined angle. Once the opening degree of the grille shutter 14 is requested, the routine shown in FIG. 3 is temporarily terminated.

When the fin portion 17 is tilted and the running wind W is introduced into the engine room, the intercooler 9 is cooled by the running wind W, and the compressed air inside the intercooler 9 radiates heat, reducing the temperature of the compressed air. . In other words, the required intake air amount is determined, the future intake air temperature after supercharging is predicted, and to what extent the compressed air passing through the intercooler 9 should be cooled so that the outlet temperature of the intercooler 9 becomes a predetermined temperature. In other words, by determining the amount of heat dissipated by the intercooler 9, it is possible to output the required opening degree request for the grill shutter 14. Also, as soon as the outlet temperature of the intercooler 9 drops, the grill shutter 14 can be opened immediately. can be closed. In other words, by determining the amount of heat dissipated by the intercooler 9, unnecessary opening of the grille shutter 14 can be prohibited, and the grille shutter 14 can be kept closed when the temperature of the compressed air is below a predetermined value. Can be done. Therefore, when driving with the grille shutter 14 closed, outside air is not introduced into the engine compartment 1, turbulence of air in the engine compartment 1 can be prevented, and the air resistance of the entire vehicle Ve is reduced. can do.

Next, FIG. 4 is a flowchart for explaining an example of control of the vehicle intake control device in Embodiment 2 of the present invention. In Embodiment 1 (FIG. 3), In contrast to the case where the outlet temperature is set to the target temperature, in the second embodiment (FIG. 4), the outlet temperature of the intercooler 9 is predicted based on the temperature of the compressed air, the amount of heat dissipated from the intercooler 9, etc. This is an example of control.

First, a required intake air amount is calculated (step S11). The required intake air amount is determined by the intake air amount calculation unit 21. Specifically, the required intake air amount of the engine 4 is calculated based on the engine speed and the accelerator opening.

Next, the future intake air temperature after supercharging is predicted (step S12). The future intake air temperature after supercharging is determined by the post-supercharging intake air temperature prediction unit 22. Specifically, the future intake air temperature after supercharging is predicted based on the detection signals from the outside air temperature sensor and the atmospheric pressure sensor, and the detection signal from the post-supercharging pressure sensor 12.

Subsequently, the amount of heat released by the intercooler 9 is calculated from the vehicle speed of the vehicle Ve and the required intake air amount determined in step S11 (step S13). Specifically, the amount of heat dissipated by the intercooler 9 is determined from a heat dissipation map stored in advance in the ECU 20 based on the required intake air amount determined by the intake air amount calculation unit 21 and the vehicle speed.

The outlet temperature of the intercooler 9 is predicted from the estimated intake air temperature determined in step S12 and the amount of heat dissipated by the intercooler 9 determined in step S13 (step S14). This can be obtained from the I/C outlet temperature prediction unit 24. Specifically, the intercooler Predict the outlet temperature of 9.

Then, it is determined whether the outlet temperature of the intercooler 9 predicted in step S14 is equal to or higher than a predetermined value (step S15). Here, the predetermined value is a temperature at which it is necessary to open the grill shutter 14, and the predetermined temperature may be changed as appropriate depending on weather conditions, driving conditions, etc. If the determination in step S15 is affirmative, opening of the grille shutter 14 is requested (step S16), and the routine shown in FIG. 4 is temporarily ended. On the other hand, if the determination in step S15 is negative, a request is made to close the grille shutter 14 (step S17), and the routine shown in FIG. 4 is temporarily ended. Note that the opening degree of the grille shutter 14 in step S16 does not have to be fully open, but may be a request for an intermediate opening degree of the grille shutter 14 in accordance with the cooling request of the intercooler 9.

In step S14, it is determined whether it is necessary to cool the intercooler 9 by predicting the future outlet temperature of the intercooler 9 based on the future intake air temperature after supercharging, the heat dissipation amount of the intercooler 9, etc. It is possible to judge whether Furthermore, since the grille shutter 14 can be opened only when it is necessary to cool the intercooler 9, unnecessary opening of the grille shutter 14 can be prohibited. Therefore, when there is no need to cool the intercooler 9, the vehicle can be driven with the grille shutter 14 closed, thereby preventing outside air from being introduced into the engine room 1 and preventing air turbulence within the engine room 1. This makes it possible to reduce the air resistance of the entire vehicle Ve.

Furthermore, by predicting the future outlet temperature of the intercooler 9, it is possible to open and close the grille shutter 14 in advance. The time required to open and close the grill shutter 14 according to the request can be shortened, rather than making a request every time. That is, since the grille shutter 14 is opened and closed by predicting the outlet temperature of the intercooler 9, it is possible to suppress the outlet temperature of the intercooler 9 from rising above a predetermined value. Further, by predicting the outlet temperature of the intercooler 9 and when there is no need to further cool the intercooler 9, the grille shutter 14 can be closed in a timely manner, thereby preventing delays in opening and closing the grille shutter 14. Therefore, unnecessary opening of the grille shutter 14 can be prohibited.

Note that this invention is not limited to the embodiments described above, and can be implemented with appropriate modifications within the scope of the objective of this invention. Furthermore, the present invention is not limited to the configuration of the flowchart described above. For example, the order of step S1 and step S2 may be changed, and the calculation and prediction of temperature and heat radiation amount may be determined by a two-dimensional array map stored in advance in the ECU 20.

1 Engine room 2 Intake passage 3 Exhaust passage 4 Engine 5 Supercharger 6 Compressor 7 Turbine 8 Air cleaner 9 Intercooler 10 Throttle valve 11 Cylinder 12 Post-supercharging pressure sensor 13 Outlet temperature sensor 14 Grill shutter 15 Body 16 Opening 17 Fin section 18 Fin shaft 19 Grill shutter opening sensor 20 Electronic control unit (ECU)
21 Intake air amount calculation unit 22 Post-supercharging intake air temperature prediction unit 23 I/C heat radiation amount prediction unit 24 I/C outlet temperature prediction unit 25 Grill shutter opening degree calculation unit Ve Vehicle W Traveling wind

Claims (1)

An air intake control device for a vehicle, comprising: a supercharger that pressurizes the intake air of an engine; an intercooler that air-cools the intake air pressurized by the supercharger; and a grille shutter that controls the amount of running air relative to the intercooler. And,
a controller that controls opening and closing of the grille shutter;
The controller includes:
predicting the temperature of the intake air after passing through the intercooler;
An intake air control device for a vehicle, wherein opening of the grille shutter is prohibited when the predicted temperature of the intake air is below a predetermined temperature.

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