JP2010209850A - Supercharging control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supercharging control device raising supercharging pressure and smoothly shifting gears when shifting the gears by a transmission. <P>SOLUTION: The supercharging control device includes a supercharger for relatively increasing an intake air amount of an internal combustion engine, and the transmission connected to the internal combustion engine in a power transmissible manner, wherein when there is a demand for increasing output of the internal combustion engine, the supercharging pressure of the supercharger is raised, and gear shifting is performed for increasing the change gear ratio by the transmission. The supercharge control device includes a supercharging pressure calculating means for obtaining a target supercharging pressure to reach during gear change transition of the transmission (step S4), a torque capacity control means for obtaining torque capacity of the transmission based on the target supercharging pressure of the supercharger (step S5), and a supercharging pressure control means for controlling an actual supercharging pressure of the supercharger based on the target supercharging pressure of the supercharger upon controlling the torque capacity of the transmission by the torque capacity control means (steps S7, S8, S9, S10, S11). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a supercharging control device that performs control to increase the intake air amount of an internal combustion engine by a supercharger and increase the transmission gear ratio when the output of the internal combustion engine is increased.

  Conventionally, a supercharger is attached to an internal combustion engine such as a diesel engine. If this supercharger is used, the amount of intake air in the internal combustion engine can be increased, and therefore the output of the internal combustion engine can be relatively increased. An example of a vehicle control device in which a supercharger is attached to an internal combustion engine is described in Patent Document 1. In Patent Document 1, an exhaust turbine supercharger is attached to a diesel engine. The turbocharger compressor is connected to the intake pipe of a diesel engine. A turbocharger turbine is connected to the exhaust manifold of the diesel engine. This supercharger is configured such that the supercharging pressure increases as the displacement of the diesel engine increases. And when the acceleration request | requirement is determined, the engine speed is raised and the supercharging pressure is raised by performing the downshift which enlarges the gear ratio of a continuously variable transmission. Patent Document 2 discloses a technique for controlling the rotation speed of a compressor of a supercharger by an electric motor.

JP 2003-39989 A JP 2004-360487 A

  However, in the vehicle control device described in Patent Document 1, when the output torque of the diesel engine increases more than expected due to an increase in the supercharging pressure, the engine torque increase control and the continuously variable transmission shift control are performed. There is a possibility that the speed change with the continuously variable transmission cannot be performed smoothly.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a supercharging control device capable of improving consistency with torque increase control of an internal combustion engine and shift control in a transmission. It is said.

  In order to achieve the above object, an invention according to claim 1 is directed to an internal combustion engine that generates power by burning a mixture of fuel and air, a supercharger that increases an intake air amount of the internal combustion engine, When there is a request to increase the output of the internal combustion engine, including a transmission that is connected to the internal combustion engine so that power can be transmitted and that can change a transmission gear ratio between an input rotation speed and an output rotation speed Further, in a supercharging control device that performs a shift to increase the supercharging pressure of the supercharger and increase the gear ratio with the transmission, the transmission in the transmission is based on a request to increase the output of the internal combustion engine. A supercharging pressure calculating means for obtaining a target supercharging pressure of the supercharger to be reached during a shift transition; a torque capacity control means for controlling the torque capacity of the transmission based on the target supercharging pressure of the supercharger; , The torque capacity of the transmission is controlled by the torque capacity control means. When controlling the capacity of the turbocharger, the difference between the target supercharging pressure of the supercharger and the actual supercharging pressure of the supercharger is equal to or less than a predetermined value set in advance. And a supercharging pressure control means for controlling the supercharging pressure.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the transmission is configured such that a gear ratio is controlled by controlling engagement and release of a plurality of clutches or brakes, and the torque. The capacity control means includes means for controlling a torque capacity of the transmission by controlling an engaging force of a clutch or a brake that is engaged after the change of the transmission gear ratio of the transmission. .

  According to a third aspect of the invention, in addition to the configuration of the first or second aspect, an electric motor for controlling the supercharging pressure of the supercharger is provided.

  According to the first aspect of the present invention, the target supercharging pressure that should be reached at the time of the shift of the transmission is obtained, and the torque capacity of the transmission is controlled based on the target supercharging pressure of the supercharger. When controlling the torque capacity of the transmission, the actual supercharging pressure of the supercharger is controlled so that the difference between the target supercharging pressure and the actual supercharging pressure is equal to or less than a predetermined value. To do. Therefore, the consistency between the control of the torque capacity of the transmission and the control of the supercharging pressure of the supercharger is improved, and the speed change can be performed smoothly.

  According to the invention of claim 2, in addition to obtaining the same effect as that of the invention of claim 1, the consistency between the engaging force of the clutch or brake to be engaged and the supercharging pressure of the supercharger is improved. The transmission can be shifted more smoothly.

  According to the invention of claim 3, in addition to obtaining the same effect as that of the invention of claim 1 or 2, the supercharging pressure of the supercharger can be controlled by the electric motor.

It is a flowchart which shows the example of control of the supercharging control apparatus in this invention. It is a schematic diagram which shows the structural example of the vehicle which can perform the example of control of FIG. It is a figure which shows an example of the time chart corresponding to the flowchart of FIG.

  Next, an embodiment of the present invention will be described with reference to the drawings. First, FIG. 2 shows a configuration example of a vehicle that can execute the control of the present invention. In the vehicle 1 shown in FIG. 2, an engine 2 is provided as a driving force source for driving the vehicle 1. The engine 2 is a power unit that burns a mixture of fuel and air in a combustion chamber, converts the thermal energy into kinetic energy, and outputs the kinetic energy. As the engine 2, an internal combustion engine, more specifically, a gasoline engine, a diesel engine, an LPG engine, or the like can be used.

  An intake pipe 3 connected to the combustion chamber of the engine 2 is provided, and an electronic throttle valve 4 for controlling the intake air amount is provided in the intake pipe 3. A supercharger 5 is provided upstream of the electronic throttle valve 4 in the direction of air intake in the intake pipe 3. An electric motor 6 that rotates a compressor (not shown) of the supercharger 5 is provided. Then, by controlling the voltage supplied to the electric motor 6, the rotational speed of the supercharger 5 is controlled, and the pressure (supercharging pressure) when the supercharger 5 sends air to the combustion chamber of the engine 2 is controlled. Can be controlled. The supercharger 5 is configured to drive a mechanical supercharger or an exhaust supercharger with an electric motor. Since the technology for driving a supercharger using an electric motor is known as described in JP-A-2005-226501, JP-A-2007-120376, JP-A-2007-198253, etc., Illustration and detailed description are omitted. An exhaust pipe 7 is connected to the combustion chamber, and the exhaust gas generated when the air-fuel mixture is burned in the combustion chamber is discharged to the exhaust pipe 7.

  A transmission 8 is provided so as to be able to transmit power to the engine 2. The transmission 8 is a transmission that can change the ratio between the input rotation speed and the output rotation speed, that is, the gear ratio. The transmission 8 may be either a stepped transmission that can change the gear ratio stepwise (discontinuously) or a continuously variable transmission that can change the gear ratio continuously (stepless). Here, a stepped transmission using a planetary gear mechanism and its control mechanism are described in JP-A-5-87231, JP-A-5-99306, JP-A-5-99316, and the like. Since it is publicly known, description of its configuration and control is omitted. Further, since the belt-type continuously variable transmission is known as described in JP-A-11-182666, JP-A-2001-323978, and the like, description of the configuration and control thereof is omitted. Further, since the toroidal type continuously variable transmission is known as described in JP-A-2002-181152, JP-A-2003-130160, and the like, description of the configuration and control thereof is omitted.

  Here, an example in which a stepped transmission, more specifically, a stepped transmission having a planetary gear mechanism and a friction engagement device is used as the transmission 8 will be described. In the transmission 8 having the planetary gear mechanism and the friction engagement device, the gear ratio is changed stepwise (discontinuously) by controlling the engagement and release of the friction engagement device. Further, the engagement and release of the friction engagement device are controlled by hydraulic pressure. Therefore, when the transmission stage is changed by the transmission 8, the transmission torque temporarily decreases or the power is interrupted during the shift. An output shaft (not shown) of the transmission 8 is connected to the drive wheel 10 through a final reduction gear 9 so that power can be transmitted. The drive wheel 10 may be either a front wheel or a rear wheel, and may be both a front wheel and a rear wheel. That is, the vehicle 1 may be either a two-wheel drive vehicle or a four-wheel drive vehicle. Furthermore, an electronic control unit 11 is provided for controlling the fuel injection amount of the engine 2, the voltage supplied to the electric motor 6, the opening degree of the electronic throttle valve 4, and the transmission gear ratio of the transmission 8. The electronic control unit 11 includes a supercharging pressure and a rotational speed of the supercharger 5, a vehicle speed, an accelerator pedal depression amount (accelerator opening), a rotational speed of the engine 2, an input rotational speed of the transmission 8 (turbine rotational speed). ), A sensor signal for detecting the output speed of the transmission 8, the amount of depression of the brake pedal, and the like is input.

  Next, the control of the vehicle 1 will be described. The vehicle speed and the accelerator opening are detected by the electronic control device 11, and the gear ratio of the transmission 8 is controlled using the shift map stored in the electronic control device 11. In this embodiment, when the accelerator opening is increased and a request to increase the engine output is generated, the downshift is performed to increase the supercharging pressure of the supercharger 5 and relatively increase the speed ratio of the transmission 8. The control example will be described based on the flowchart of FIG. First, it is determined whether or not the accelerator pedal is depressed to satisfy the downshift condition of the transmission 8 and the downshift control is being executed (step S1). This is a step of determining whether or not the friction engagement device is being engaged and released. If the determination in step S1 is affirmative, it is determined whether or not the electric motor 6 is controlled to increase the supercharging pressure of the supercharger 5 (step S2). If a negative determination is made in step S2 or step S1, the process returns. The increase amount of the supercharging pressure of the supercharger 5 performed at this time is a value obtained by using a map or the like based on an increase in acceleration request.

  If the determination in step S2 is affirmative, it is determined whether it is the oil pressure setting timing at the time of rotation speed synchronization (step S3). Here, the rotational speed synchronization means that the synchronous rotational speed corresponding to the downshift of the transmission 8 matches the actual turbine rotational speed. The synchronous rotation speed is obtained by multiplying the output rotation speed of the transmission 8 and the speed ratio after the downshift of the transmission 8. That is, prior to controlling the hydraulic pressure of the friction engagement device (the hydraulic pressure of the friction engagement device to be engaged) at the time of rotation speed synchronization, whether or not the current time is the timing at which the hydraulic pressure of the friction engagement device should be set. Judging. The determination of whether or not it is the hydraulic pressure setting timing at the time of rotation speed synchronization is, for example, the elapsed time since the start of the downshift control, or the friction engagement device that is engaged at the shift stage after the downshift. This can be done according to the elapsed time after outputting the hydraulic pressure increase instruction. These elapsed times are obtained in advance by experiments or simulations, and the values are stored in the electronic control unit 11. Further, in step S3, when the value obtained by subtracting the actual turbine rotation speed from the synchronous rotation speed becomes equal to or less than a predetermined value, it is determined that the hydraulic pressure setting timing at the rotation speed synchronization is reached, and the actual turbine speed is determined from the synchronous rotation speed. When the value obtained by subtracting the rotational speed exceeds a predetermined value, it can be determined that it is not the hydraulic pressure setting timing at the time of rotational speed synchronization.

  If the determination in step S3 is affirmative, a target supercharging pressure (predicted supercharging pressure) of the supercharger 5 during the engagement and release of the friction engagement device is calculated (step S4). This predicts the target supercharging pressure during gear shifting from the rotational speed and supercharging pressure of the supercharger 5 at the present time, and predicts the target supercharging pressure after a predetermined time, that is, at the time of rotational speed synchronization ( (Estimate). Needless to say, the target boost pressure is premised on satisfying the acceleration requirement after the downshift. In order to perform the process of step S4, data obtained by experiments or simulations is stored in advance in the electronic control unit 11. Following this step S4, the engagement hydraulic pressure of the friction engagement device engaged at the gear stage after the shift is obtained from the target boost pressure (step S5), and the process returns. This step S5 is to obtain the engagement hydraulic pressure of the friction engagement device during the shift of the transmission 8 based on the output torque of the engine 2.

  On the other hand, if a negative determination is made in step S3, it is determined whether or not the hydraulic pressure of the friction engagement device at the time of rotation speed synchronization has been set (step S6). If a negative determination is made in step S6, the process returns. If the determination in step S6 is affirmative, whether or not the value obtained by dividing the target supercharging pressure (predicted supercharging pressure) from the current supercharging pressure of the supercharger 5 exceeds a predetermined value A is determined. Determination is made (step S7). If a negative determination is made in step S7, it is determined whether or not a value obtained by subtracting the current supercharging pressure of the supercharger 5 from the target supercharging pressure exceeds a predetermined value A (step S8). ). The predetermined value A is a threshold value for determining whether or not the correspondence relationship between the actual supercharging pressure of the supercharger 5 and the engagement hydraulic pressure of the friction engagement device is appropriate. More specifically, it is a value obtained by experiment or simulation from the torque capacity that allows the shift to proceed without incurring a shift shock with respect to changes in engine torque.

  The negative determination in step S7 and the negative determination in step S8 means that the actual supercharging pressure substantially coincides with the target supercharging pressure. The voltage of the electric motor 6 that drives 5 is maintained at the current value (step S9), and the process returns. On the other hand, if a positive determination is made in step S8, the current supercharging pressure is too low compared to the target supercharging pressure, so the voltage of the electric motor 6 that drives the supercharger 5 is increased ( Step S10) and return. Furthermore, if the determination in step S7 is affirmative, the current supercharging pressure is too high compared to the target supercharging pressure, so the voltage of the electric motor 6 that drives the supercharger 5 is reduced (step S11). To return. As described above, the difference between the actual boost pressure and the target boost pressure is controlled to be equal to or less than the predetermined value A by the processes of steps S8, S9, S10, and S11.

  Next, an example of a time chart corresponding to the control example of FIG. 1 will be described with reference to FIG. The time chart of FIG. 3 shows a shift (clutch toe) established by releasing one of the friction engagement devices and engaging another friction engagement device when downshifting is performed in the transmission 8.・ Clutches are supported. In FIG. 3, the accelerator pedal is depressed (accelerator ON) before time t1, the downshift condition is satisfied, and the hydraulic pressure indication value of the friction engagement device released at the shift stage after the downshift decreases before time t1. is doing. That is, the downshift is started in the transmission 8. With this control, the engine speed starts to increase. At time t1, the hydraulic pressure instruction value of the friction engagement device engaged at the shift stage after the downshift starts to increase, and the input rotational speed of the transmission 8 starts to increase. The subsequent time t2 is the hydraulic pressure setting timing determined in step S3, and at the time t3, the input rotational speed of the transmission 8 coincides with the synchronous rotational speed after the downshift (rotational speed synchronization). That is, the downshift of the transmission 8 is completed at time t3. Further, the hydraulic pressure instruction value of the friction engagement device to be released is the lowest value at time t4.

  Thus, when the acceleration request increases in the vehicle 1, the supercharging pressure of the supercharger 5 is increased to increase the engine output, and the transmission 8 performs a downshift. At this time, the hydraulic pressure of the friction engagement device to be engaged when downshifting with the transmission 8 is set in accordance with the engine torque in steps S4 and S5. A signal for switching the gear position of the transmission 8 is output from the electronic control unit 11, but the actual hydraulic pressure causes a response delay with respect to the command hydraulic pressure. Further, the supercharging pressure of the supercharger 5 rises with time, but the supercharging pressure may vary. Then, there is a possibility that the engagement timing of the friction engagement device engaged at the shift stage after the downshift of the transmission 8 is delayed, and the drive force increase timing due to the downshift is delayed. On the other hand, in the control of FIG. 1, the difference between the actual boost pressure and the target boost pressure is controlled to be equal to or less than the predetermined value A by the processes of steps S8, S9, S10, and S11. Therefore, the torque of the friction engagement device is set so that the increase timing of the engine torque due to the increase of the supercharging pressure of the supercharger 5 matches the engagement timing of the friction engagement device and no shift shock occurs. Smooth engagement can be performed by appropriately controlling the capacity.

  In the schematic diagram of FIG. 2, the supercharger 5 is driven by the electric motor 6. However, the supercharger 5 is driven by the torque of the engine 2. In addition to the exhaust supercharger (turbocharger) driven by the kinetic energy of the exhaust gas, the control of FIG. 1 can also be executed by a vehicle that also has a configuration driven by the electric motor 6. In this case, instead of determining whether or not the supercharger 5 is driven by the electric motor 6 at the time of determination in step S2, it is determined whether or not the supercharger 5 is operating. And when progressing to step S9, the control which maintains the supercharging pressure of the supercharger 5 is performed, without carrying out powering and regeneration of the electric motor 6. FIG. When the process proceeds to step S10, the electric motor 6 is driven to perform control for increasing the supercharging pressure of the supercharger 5. On the other hand, when it progresses to step S11, regenerative control of the electric motor 6 is performed and control which reduces the supercharging pressure of the supercharger 5 is performed. Furthermore, as a supercharger in this invention, the structure which provided the exhaust-type supercharger or the mechanical supercharger, and also provided the supercharger driven by an electric motor may be sufficient.

  The transmission 8 has a configuration in which the friction engagement device is engaged and released, and the torque capacity of the friction engagement device is controlled by hydraulic pressure. The control shown in FIG. 1 can also be executed in a vehicle having a stepped transmission having an electromagnetic clutch or an electromagnetic brake whose release is controlled. That is, the torque capacity of the electromagnetic brake and the electromagnetic clutch is controlled by the electromagnetic force. Thus, in the case of a transmission having an electromagnetic brake and an electromagnetic clutch, “hydraulic pressure” described in the description of FIG. 1 may be read as “electromagnetic force”.

  Furthermore, the control shown in FIG. 1 can be executed even in a vehicle using a continuously variable transmission as the transmission 8, specifically, a belt type continuously variable transmission or a toroidal type continuously variable transmission. The continuously variable transmission does not engage and disengage the clutch and brake, but can control to increase the torque capacity of the continuously variable transmission as the engine torque increases. Here, when the control of FIG. 1 is executed, in step S3, it is determined whether or not the remaining time until the end of the shift is equal to or less than a predetermined time. If the determination in step S3 is affirmative, Proceed to S4. In step S4, the target boost pressure during the shifting of the continuously variable transmission is obtained, and in step S5, the torque capacity instruction value of the continuously variable transmission is obtained. Further, if a negative determination is made in step S3, the process proceeds to step S6, and in step S6, it is determined whether or not a torque capacity instruction during the shift has been set. Thereafter, the same processing as that of the stepped transmission may be performed. In this way, when the transmission is a continuously variable transmission, the control shown in FIG. 1 can be performed smoothly, that is, without a shock.

  Here, the correspondence between the functional means shown in FIG. 1 and the configuration of the present invention will be described. Step S4 corresponds to the supercharging pressure calculation means of the present invention, and step S5 represents the torque of the present invention. It corresponds to the capacity control means, and steps S7, S8, S9, S10, S11 correspond to the supercharging pressure control means of this invention. In the present invention, the shift of the transmission controlled by the shift control means includes the torque capacity during the shift of the transmission.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine, 5 ... Supercharger, 6 ... Electric motor, 8 ... Transmission, 11 ... Electronic control apparatus.

Claims (3)

An internal combustion engine that generates power by burning a mixture of fuel and air, a supercharger that increases the amount of intake air of the internal combustion engine, a power transmission to the internal combustion engine, and an input rotational speed And a transmission capable of changing the speed ratio between the output speed and the output of the internal combustion engine when there is a request to increase the boost pressure of the supercharger, and In the supercharging control device that performs a shift to increase the gear ratio in the transmission,
A supercharging pressure calculating means for obtaining a target supercharging pressure of the supercharger to be reached at the time of a shift transition in the transmission based on a request to increase the output of the internal combustion engine;
Torque capacity control means for controlling the torque capacity of the transmission based on the target supercharging pressure of the supercharger;
When controlling the torque capacity of the transmission by the torque capacity control means, the difference between the target supercharging pressure of the supercharger and the actual supercharging pressure of the supercharger is equal to or less than a predetermined value. And a supercharging pressure control means for controlling the actual supercharging pressure of the supercharger. The transmission is configured to control a gear ratio by controlling engagement and disengagement of a plurality of clutches or brakes,
The torque capacity control means includes means for controlling a torque capacity of the transmission by controlling an engaging force of a clutch or a brake that is engaged after the change of the transmission gear ratio of the transmission. Item 2. The supercharging control device according to Item 1.   The supercharging control apparatus according to claim 1, further comprising an electric motor that controls a supercharging pressure of the supercharger.

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