JP2005330834A - Control device for powertrain equipped with electric supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress problems in acceleration response and surging of an electric supercharger when drives of the electric supercharger and a motor are controlled according to operation conditions of an engine in a powertrain equipped with the electric supercharger. <P>SOLUTION: Both of the motor and the electric supercharger are put in non-operation state in a zone X where a target torque established based on engine load and engine speed is a first predetermined value Twot or less, only the motor is put in the operation state in a zone Y where the target torque is larger than the first predetermined value Twot and is a second predetermined value Ty larger than the first predetermined value Twot or less, and both of the motor and the electric supercharger are put in operation state in a zone Z where the target torque is larger than the second predetermined value Ty. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes a powertrain control device including an electric supercharger, more specifically, an electric supercharger for increasing engine output, and a traveling motor that functions as a power source for the vehicle. The present invention belongs to the technical field of powertrain control devices configured to switch these drives in accordance with the operating state of the engine.

  Conventionally, superchargers and turbochargers have been well known as means for increasing engine output, but both have the problem of insufficient supercharging pressure in the low engine speed range as a result of the supercharging capacity being greatly affected by the engine speed. There is. In contrast, an electric supercharger that drives a compressor with a motor can control the rotation speed of the compressor without being affected by the rotation speed of the engine, so that it can generate a sufficient boost pressure even in a low rotation speed region. Have.

  On the other hand, in recent years, low-pollution vehicles and environment-friendly vehicles equipped with an electric motor that functions as a power source of the vehicle in addition to the engine are known. For example, Patent Document 1 discloses such a motor and the electric motor. A powertrain having a supercharger is disclosed. And, in this way, in a vehicle equipped with an electric supercharger that increases the output of the engine and a travel motor that assists the engine with torque, for example, rotation-related values such as engine speed and vehicle speed, Each area indicating the driving state of the electric supercharger and the electric motor is displayed on the map according to the operating state of the engine using the torque-related values such as the engine load represented by the accelerator opening and the intake air amount as parameters. The actual engine speed and engine load are applied to this map, and the basic output control of the engine or the power train is executed to switch the driving of the electric supercharger and the electric motor according to the result. .

  In this regard, according to Patent Document 1, as disclosed in paragraphs 0014 to 0016, paragraph 0021, FIG. 2, and FIG. 9, when the target torque is equal to or less than a predetermined value (first state), When the vehicle is driven only by the output of the natural intake of the engine (non-supercharging region) and the target torque is larger than the predetermined value but not more than a second predetermined value larger than the predetermined value (second state), Only the electric supercharger is in an operating state to increase torque (supercharging region), and when the target torque is larger than the second predetermined value (third state), the motor is also operating in addition to the electric supercharger. As shown, the torque assist by the motor is performed (torque assist region). In other words, the torque increase by the electric supercharger is used as the main torque raising means, and the torque increase means by the motor is used as the torque raising means.

JP-A-11-332015

  However, in general, an electric supercharger takes a relatively long time from when electric power is supplied until the rotational speed of the turbine disposed in the intake passage increases and the supercharging pressure reaches the target pressure. There is a problem that acceleration response is inferior. Further, in the low rotation region where the intake flow rate is small, there is a problem of surging (pulsation) in which the discharge pressure and discharge flow rate of the turbine periodically fluctuate, and as a result, the target boost pressure or target torque is not achieved, There are also concerns about damage to the electric supercharger and the intake passage.

  The present invention addresses the above-described problems in a power train equipped with an electric supercharger. When controlling the electric supercharger and the motor according to the operating state of the engine, It is an object of the present invention to suppress the acceleration responsiveness problem and surging problem of the electric supercharger. Hereinafter, the present invention will be described in detail including other problems.

  That is, the invention described in claim 1 of the present application includes a motor that introduces assist torque into a power transmission path from the engine to the drive wheels, an electric supercharger that is provided in an intake passage of the engine and supercharges intake air, Batteries for supplying electric power to these motors and electric superchargers, engine load detection means for detecting parameters related to engine load, engine speed detection means for detecting parameters related to engine speed, and detection by both detection means A powertrain control device comprising an electric supercharger having a control means for controlling the motor and the electric supercharger according to a result, wherein the engine load detected by the engine load detection means and the above Target torque setting means for setting a target torque based on the engine speed detected by the engine speed detection means is provided. In the first state where the target torque set by the target torque setting means is equal to or less than a first predetermined value, both the motor and the electric supercharger are deactivated, and the target torque is set to the first predetermined value. In the second state, which is larger than the first predetermined value and less than or equal to the second predetermined value, only the motor is operated, and in the third state where the target torque is larger than the second predetermined value, the motor and the The electric supercharger is configured to be in an operating state together.

  Next, according to a second aspect of the present invention, in the first aspect of the present invention, motor driving force detecting means for detecting a parameter relating to the driving force of the motor is provided, and the control means detects the detection in the second state. When the motor driving force detected by the means drops below a predetermined value, the electric supercharger is configured to be in an operating state.

  Next, according to a third aspect of the present invention, in the first aspect of the present invention, there is provided battery storage amount detection means for detecting a parameter relating to the storage amount of the battery, and the control means is configured to detect the detection in the second state. The electric supercharger is configured to be in an operating state when the battery storage amount detected by the means decreases below a predetermined value.

  Next, the invention described in claim 4 is the invention described in claim 3, characterized in that a supercharger pre-rotating means for pre-rotating the electric supercharger in the first state is provided. And

  According to a fifth aspect of the invention, in the invention of the fourth aspect, the supercharger pre-rotation means pre-rotates according to the battery charge amount detected by the battery charge amount detection means in the first state. It is characterized by setting an amount.

  First, according to the first aspect of the present invention, when the drive of the electric supercharger and the motor is controlled in accordance with the operating state of the engine in the power train provided with the electric supercharger, the target torque is the first torque. In a first state that is less than or equal to the predetermined value, both the motor and the electric supercharger are inactivated, the vehicle is driven only by the output of the natural intake of the engine, and the target torque is greater than the first predetermined value. In the second state, which is equal to or smaller than the second predetermined value greater than the first predetermined value, only the motor is operated, torque assist is performed by the motor, and in the third state where the target torque is greater than the second predetermined value. Since the motor and the electric supercharger are both in an operating state and the torque is increased by the electric supercharger, that is, the torque assist mainly by the motor is high. Since it is used as a means for increasing the torque by the electric supercharger, the torque increase by the electric supercharger is used as the main means for increasing the torque as in the conventional case. The frequency of use of the electric supercharger is reduced as compared with the case where it is used as a torque raising means that follows the assist, and as a result, the acceleration responsiveness problem and the surging problem of the electric supercharger are suppressed.

  In addition, you may provide the generator which produces | generates the electric power accumulate | stored in a battery as another structure, As such a generator, what was drive-coupled directly or indirectly to the output shaft of an engine etc., for example Is preferably employable.

  Next, according to the second aspect of the present invention, when the driving force of the motor, that is, the assisting force of the motor is reduced to a predetermined value or less in the second state in which only the motor is operated, the electric supercharger Since the motor is continuously driven for a long time in the second state, the battery temperature and the motor temperature are excessively increased and the driving force of the motor is reduced. Even in this case, the torque is ensured, and the acceleration response at the time of transition from the first state to the second state is sufficiently ensured.

  In this case, when the electric supercharger is in the operating state, the driving of the motor may be weakened or the driving of the motor may be stopped.

  The parameters relating to the driving force of the motor include, for example, the battery temperature (the higher the motor driving force, the lower the motor driving force), the motor temperature (the same), and the battery and motor usage time (the longer the motor driving force decreases). ), Etc. are preferably used.

  Next, according to the third aspect of the present invention, similarly, in the second state in which only the motor is in the operating state, when the stored amount of the battery falls below a predetermined value, the electric supercharger is also operated. For example, when the motor is continuously driven for a long time in the second state, the amount of power stored in the battery is excessively consumed and the driving force of the motor is reduced. However, the torque is ensured, and the acceleration response at the time of transition from the first state to the second state is sufficiently ensured.

  In this case as well, when the electric supercharger is in the operating state, the driving of the motor may be weakened or the driving of the motor may be stopped. As a result, the consumption of the battery storage amount is reduced or zero, and the battery storage amount is prevented from excessively decreasing (so-called battery rising).

  However, in this case, there is a concern about battery consumption due to the operating state of the electric supercharger, but in general, the electric power consumption of the electric supercharger is considerably smaller than that of the assist motor (for example, about one fifth). From the above, the above problem of battery exhaustion can be sufficiently avoided.

  As the parameters relating to the amount of electricity stored in the battery, for example, the voltage value of the battery (the higher the amount, the higher the amount of electricity stored), the current value of the battery (the same), and the like are preferably used.

  Next, according to the invention described in claim 4, in addition to the configuration of the invention described in claim 3, in the first state where both the motor and the electric supercharger are inactive, the electric supercharger Is pre-rotated, the electric supercharger responds promptly at the time of transition from the first state to the second state, and the torque increase by the electric supercharger rises well.

  As a result, for example, the amount of power stored in the battery is excessively reduced at the stage of the first state before the transition to the second state, and it is predicted that the assist force of the motor will be insufficient when the transition to the second state occurs. Even when the electric supercharger is in the operating state at the time of transition, the torque can be sufficiently secured, and the acceleration response at the time of transition from the first state to the second state is sufficiently performed. .

  According to the invention described in claim 5, in addition to the configuration of the invention described in claim 4, according to the battery storage amount detected in the stage of the first state, in other words, the second state Since the pre-rotation amount is set in accordance with the motor assist force that is predicted when the state shifts to, the torque increase of the electric supercharger during the transition from the first state to the second state is the motor assist. It will stand up appropriately according to power. Hereinafter, the present invention will be described in more detail through the best mode for carrying out the invention.

  As shown in FIG. 1, the power train 1 according to the present embodiment is mounted on a hybrid vehicle that uses an engine 10 and a drive motor 16 together as a drive source. The powertrain 1 includes an engine 10 that generates a driving force for traveling the vehicle, and a continuously variable transmission 11 that can continuously change the output rotation of the engine 10. The type of continuously variable transmission 11 is not particularly limited. Preferably, for example, a toroidal continuously variable transmission in which a power roller is tiltably interposed between an input disk and an output disk, in particular, a torque converter. These include geared neutral type continuously variable transmissions that do not require adoption. The output torque of the engine 10 is shifted to a predetermined gear ratio by the continuously variable transmission 11 and then transmitted to the left and right drive wheels 13 and 13 through the differential device 12 and the like.

  On the power transmission path 14 between the engine 10 and the drive wheels 13, 13, a connection / disconnection mechanism 15 using, for example, a clutch or the like is disposed, and a drive motor (assist motor) 16 is connected via the connection / disconnection mechanism 15. Is coupled to the power transmission path 14. The drive motor 16 is supplied with electric power from the battery 18 by current control by the inverter 17 and generates a rotational driving force sufficient to run the vehicle. The generated driving force is transmitted via the connection / disconnection mechanism 15. Introduced into the power transmission path 14. The drive motor 16 can function as a generator that generates electric power using the rotational driving force on the power transmission path 14 during deceleration regeneration, and the generated electric power is stored in the battery 18.

  In the present embodiment, the assist motor 16 is located behind the transmission 11 (on the drive wheels 13 and 13 side) on the power transmission path 14 as described above. Thus, the output converted at the gear ratio of 11 is introduced into the power transmission path 14.

  An alternator 19 that is an AC generator is connected to the output shaft of the engine 10 via a belt, a chain, or the like. The alternator 19 is directly driven by the output rotation of the engine 10 to generate electric power, and the generated electric power is stored in the battery 18.

  An electric supercharger 21 that supercharges intake air to increase the output of the engine 10 is provided in the intake passage 20 of the engine 10. The electric supercharger 21 is a supercharger motor 22 that rotationally drives a turbine 23 on the intake passage 20 and pumps (supercharges) intake air in an amount larger than natural intake air of the engine 10 to the combustion chamber. Similarly to the drive motor 16, the electric supercharger 21 is driven by the supply of electric power from the battery 18.

  In the intake passage 20, an intercooler 24 and a throttle valve 25 are arranged in this order downstream of the electric supercharger 21. The throttle valve 25 is an electric type that is driven to open and close by a dedicated actuator 26. A bypass passage (also referred to as a relief passage or a recirculation passage) 27 is provided between the upstream of the electric supercharger 21 and the downstream of the intercooler 24. This passage 27 once exits the intercooler 24 in order to ensure the supercharging capability of the electric supercharger 21 when the intake air flow rate passing through the turbine 23 of the electric supercharger 21 is small, for example, in the low rotation region. The intake air is returned again to the upstream side of the electric supercharger 21 to secure the intake air flow rate passing through the turbine 23. The bypass passage 27 is provided with a relief valve 28 for adjusting the opening degree of the passage 27 (that is, the circulation amount of intake air passing through the turbine 23).

  As described above, the electric system of the power train 1 has a configuration in which the drive motor 16, the alternator 19, and the motor 22 of the electric supercharger 21 are electrically connected to the battery 18. When the drive motor 16 and the supercharger motor 22 are driven, electric power is supplied from the battery 18, respectively. On the other hand, when the drive motor 16 functions as a generator during deceleration regeneration, and the alternator 19 is an engine. When power generation is performed by the output rotation of 10, the generated power is supplied to the battery 18 and used for charging the battery 18.

  The control unit 40 of the power train 1 detects a signal from the supercharger motor temperature sensor 29 that detects the temperature of the motor 22 of the electric supercharger 21 and the intake air temperature immediately after exiting the intercooler 24 in the intake passage 20. A signal from the intake air temperature sensor 30 to detect, a signal from the intake air pressure sensor 31 to detect the intake air pressure immediately upstream of the throttle valve 25 in the intake passage 20, and an accelerator opening sensor 33 to detect the amount of depression of the accelerator pedal 32 by the driver. , A signal from the water temperature sensor 34 that detects the coolant temperature of the engine 10, a signal from the engine speed sensor 35 that detects the rotation speed of the engine 10, and the temperatures of the drive motor 16, the inverter 17, and the battery 18. Signals from the temperature sensors 36, 37, and 38 to be detected and state quantities relating to the amount of power stored in the battery 18 (eg A signal from the charged amount sensor 39 for detecting a pressure value, a current value, etc.), and based on the input results, the relief valve 28 on the bypass passage 27, the motor 22 of the electric supercharger 21, Current applied to a throttle actuator 26 for opening and closing the throttle valve 25, a continuously variable transmission (more specifically, various solenoids, pressure regulating valves, etc. disposed in a hydraulic control circuit for shift control), and a drive motor 16 Various control signals are output to the control inverter 17 and the like, and output control of the engine 10, torque assist control of the motor 16, or torque increase control of the electric supercharger 21 is executed.

  Next, features of the power train 1 will be described with reference to FIG. First, FIG. 2 is a map showing the control region of the engine 10. In this map, three regions X, Y, and Z are set with the engine speed and torque as parameters. The region X on the lowest torque side is a natural intake region, that is, a non-supercharging region. In this region X, neither the motor 16 nor the electric supercharger 21 is driven, and only an output by natural intake of the engine 10 is obtained. A region Y on the high torque side adjacent to the natural intake region X is a motor assist region. In this region Y, only the motor 16 is driven, and torque assist by the motor 16 is performed. A region Z on the highest torque side adjacent to the motor assist region Y is an electric supercharging region. In this region Z, the electric supercharger 21 is driven in addition to the motor 16, and the torque is increased by the electric supercharger 21.

  Here, as will be described later, the target torque is set based on the vehicle speed or the engine speed and the accelerator opening (engine load). Therefore, when the driver requests acceleration and depresses the accelerator pedal 32, for example, the target torque increases as indicated by A → B in the figure, and the transition from the natural intake area X to the motor assist area Y occurs. As a result, the engine 10 is operated at full throttle, and the drive of the motor 16 is controlled so as to achieve the target torque. Alternatively, when the driver requests greater acceleration and depresses the accelerator pedal 32 more, for example, the target torque increases as indicated by A → C in the figure, and the natural intake region X changes to the electric supercharging region Z. Transition takes place. As a result, the engine 10 is operated at full throttle, the motor 16 is driven with the maximum torque, and the electric supercharger 21 is further driven and controlled to achieve the target torque.

  In this embodiment, the line Twot that divides the regions X and Y shown in the figure is the maximum torque line by natural intake of the engine 10, and the line Ty that divides the regions Y and Z shown in the figure is In the present embodiment, it is the maximum torque line of the motor 16.

  As described above, in the present embodiment, in the natural intake region X (first state) where the target torque is equal to or less than the first predetermined value Two, the motor 16 and the electric supercharger 21 are both inoperative and the vehicle is engineed. The motor assist region Y (the second motor assist region Y) (second motor) in which the target torque is greater than the first predetermined value Twot and less than or equal to the second predetermined value Ty greater than the first predetermined value Twot. In the state), only the motor 16 is operated and torque assist is performed by the motor 16. Next, in the electric supercharging region Z (third state) where the target torque is larger than the second predetermined value Ty, the motor 16 In addition, both the electric supercharger 21 and the electric supercharger 21 are in an operating state so as to increase torque by the electric supercharger 21. That is, the torque assist by the motor 16 is used as a main torque raising means, and the torque increase means by the electric supercharger 21 is used as a torque raising means. Therefore, as compared with the conventional case, the increase in the torque by the electric supercharger 21 is used as the main torque raising means, and the electric supercharger 21 is used as the torque raising means followed by the torque assist by the motor 16. The frequency of use is reduced, and as a result, the problem that the electric supercharger 21 is inferior in acceleration response, the problem that the electric supercharger 21 generates surging (pulsation) in a low rotation region, and the like are effectively suppressed. It becomes.

  For example, FIG. 3 is a time chart at the time of transition from the natural intake region X to the motor assist region Y (acceleration) in the present embodiment. In the present embodiment, as a result of driving the motor 16 in the assist region Y, the actual torque follows the target torque To well without causing a significant response delay from the transition control start time ta, as indicated by reference numeral a. Get up quickly.

  On the other hand, FIG. 4 is a time chart at the time of transition from the natural intake region X to the region Y, that is, the electric supercharging region Y in the related art. Conventionally, as a result of driving the electric supercharger 21 in the region Y, as shown by the symbol a, a large response delay occurs from the start time ta of the transition control, and the actual torque is slowly delayed from the target torque To. Stand up. This is because, after supplying electric power to the electric supercharger 21 (time ta), the rotational speed of the turbine 23 disposed in the intake passage 21 rises to the target rotational speed Nbo (time tb), and thereafter This is because it takes a relatively long time for the supply pressure to reach the target pressure.

  FIG. 5 is a time chart at the time of transition from the natural intake region X to the electric supercharging region Z in the present embodiment. In the present embodiment, both the motor 16 and the electric supercharger 21 are driven in the electric supercharging region Z, the torque increase by the motor 16 is the main, and the torque increase by the electric supercharger 21 is the subordinate. As shown in FIG. 5, the electric supercharger 21 is driven, but its influence is reduced, and the actual torque rises quickly following the target torque To without much delay from the transition control start time ta. (Time tb).

  On the other hand, FIG. 6 is a time chart at the time of transition from the natural intake area X to the area Z, that is, the motor assist area Z in the related art. Conventionally, both the electric supercharger 21 and the motor 16 are driven in the region Z, and the torque increment by the electric supercharger 21 is the main and the torque increment by the motor 16 is the subordinate. Although the motor 16 is driven, the influence is reduced, and a large response delay occurs from the start time ta of the transition control, and the actual torque rises slowly with a large delay from the target torque To. Also, after supplying electric power to the electric supercharger 21 (time ta), the rotational speed of the turbine 23 disposed in the intake passage 21 increases to the target rotational speed Nbo (time tb), and then This is because it takes a relatively long time for the supercharging pressure to reach the target pressure.

  On the other hand, FIG. 7 is a time chart at the time of transition from the natural intake area X to the motor assist area Y in the present embodiment, as in FIG. This time chart shows that, after moving to the motor assist region Y, for example, when the motor 16 is continuously driven for a long time, the temperature of the battery 18 rises to a predetermined value A or more (time tc). As shown, when the driving force of the motor 16 is likely to decrease, the driving of the motor 16 is stopped and the driving of the electric supercharger 21 is started instead. As a result, the torque during the transition from the natural intake region X to the motor assist region Y is sufficiently ensured, and hence the acceleration response is sufficiently ensured.

  Next, FIG. 8 is also a time chart at the time of transition from the natural intake area X to the motor assist area Y in the present embodiment, as in the case of FIG. This time chart shows that, after moving to the motor assist region Y, for example, the motor 16 is continuously driven for a long time, so that the charged amount of the battery 18 decreases to a predetermined value B or less (time tc). As indicated by, when there is a possibility that the driving force of the motor 16 is reduced, the driving of the motor 16 is stopped and the driving of the electric supercharger 21 is started instead. As a result, the torque during the transition from the natural intake region X to the motor assist region Y is sufficiently ensured, and hence the acceleration response is sufficiently ensured.

  In addition, since the power consumption of the electric supercharger 21 is as small as, for example, about one fifth of the power consumption of the motor 16, the rate of decrease of the battery charge amount after the switching time tc from the motor 16 to the electric supercharger 21 is remarkably high. It is getting smaller. This avoids the problem of battery exhaustion with respect to the battery 18.

  9 is also a time chart at the time of transition from the natural intake area X to the motor assist area Y in the present embodiment, as in the case of FIG. This time chart shows that the electric supercharger 21 is pre-rotated at a predetermined target value Npre before shifting to the motor assist region Y. Thereby, at the time of the transition from the natural intake area X to the motor assist area Y, the electric supercharger 21 responds quickly, and as shown by the symbol K, the torque increase by the electric supercharger 21 rises well. (Time tb). As a result, for example, the amount of power stored in the battery 18 is excessively reduced at the stage of the natural intake area X before shifting to the motor assist area Y, and the assist force of the motor 16 is insufficient when moving to the motor assist area Y is predicted. In the case where it is predicted that the electric supercharger 21 will be in an operating state at the time of transition to the motor assist area Y, torque is secured at the time of transition from the natural intake area X to the motor assist area Y, and hence acceleration Ensuring responsiveness is sufficient.

  Hereinafter, it will be described in more detail with reference to a flowchart. As described above, in the present embodiment, since the motor 16 is disposed after the transmission 11, the drive control related to the motor 16 is the drive control obtained by converting the gear ratio of the transmission 11 to the engine 10. It is carried out.

  FIG. 10 is a flowchart illustrating a first example of the control operation of the engine 10. First, after inputting various signals in step S1, a target torque To is calculated from the accelerator opening α and the engine speed Ne in step S2. Next, in step S3, it is determined whether or not the target torque To is equal to or less than a first predetermined value Two. If the result is YES, that is, if it is in the first state (natural intake region X), the motor 16 and the electric motor A well-known powertrain control based on, for example, the accelerator opening degree α, the engine speed Ne, or the like is performed so that both the turbochargers 21 are inactive. However, as shown in the figure, in this first state, a subroutine (described later) for pre-rotation control of the electric supercharger 21 is executed in step S4.

  On the other hand, if NO in step S3, after setting the throttle opening TVO to 100% in step S5, it is determined in step S6 whether the target torque To is greater than or equal to the second predetermined value Ty. As a result, when NO, that is, when in the second state (motor assist region Y), the motor 16 is put into an operating state, but before that, in step S7, the temperature of the battery 18 reaches the predetermined temperature A ( See FIG. 7). That is, for example, as a result of the motor 16 being continuously driven for a long time in the motor assist region Y, it is determined whether or not there is a possibility that the temperature of the battery 18 rises excessively and the driving force of the motor 16 is reduced. In this sense, the determination in step S7 may be performed based on the temperature of the motor 16, the temperature of the inverter 17, the elapsed time after shifting to the motor assist area Y, or the like instead of the temperature of the battery 18.

  As a result, when the answer is YES, that is, when the temperature of the battery 18 is equal to or lower than the predetermined temperature and there is no concern about reducing the driving force of the motor 16, the process proceeds to step S8. It is determined whether or not it is greater than or equal to B (see FIG. 8). That is, for example, it is determined whether or not there is a possibility that the driving power of the motor 16 may be reduced due to excessive consumption / reduction of the amount of power stored in the battery 18 as a result of the motor 16 being continuously driven for a long time in the motor assist region Y. is there. As a result, when the answer is YES, that is, when the charged amount of the battery 18 is sufficient and there is no concern about the reduction of the driving force of the motor 16 from this point, the process proceeds to step S9 and the motor 16 is realized so that the target torque To is realized. (However, as described above, the gear ratio of the transmission 11 is converted. Hereinafter, the drive control of the motor 16 is the same in accordance therewith). Thus, the control of FIG. 3 (control during transition from region X to region Y) is realized.

  On the other hand, when NO in step S7, that is, when the temperature of the battery 18 is higher than the predetermined temperature A and there is a risk of reducing the driving force of the motor 16, or when NO in step S8, that is, when the battery 18 is charged. If the amount is lower than the predetermined charged amount B and is deficient, and there is a concern about reducing the driving force of the motor 16 from this point, the process proceeds to step S10.

  In step S10, it is determined whether or not the operating state is in a non-supercharging region, more specifically, whether or not the engine speed Ne is in a surging region or the target torque To is in a knocking region. Here, as illustrated in FIG. 11, a region where the engine speed Ne is relatively low is a surging region. When the electric supercharger 21 is driven in this surging region, a surging (pulsation) problem occurs in the electric supercharger 21 with high possibility. Further, a region where the target torque To is relatively high is defined as a knocking region. When the electric supercharger 21 is driven in this knocking region, the problem of knocking (abnormal combustion) occurs in the engine 10 with high possibility.

  However, as shown in the figure, the knocking region is reduced as the engine water temperature is lower. This is because the problem of knocking is less likely to occur as the engine water temperature is lower, and accordingly, when the engine water temperature is low, the drive of the electric supercharger 21 is permitted even if the target torque To is high.

  Returning to FIG. 10, when NO in step S <b> 10, that is, when there is no problem even if the electric supercharger 21 is driven, in step S <b> 11, electric supercharging that realizes the target torque To based on the target torque To. The torque increment (required supercharging torque) Tbo by the machine 21 is calculated. Next, in step S12, the rotational speed (target supercharging speed) Nbo of the turbine 23 of the electric supercharger 21 that achieves the required supercharging torque Tbo is set. In step S13, the electric supercharger 21 is feedback-controlled so that the target supercharging speed Nbo is realized. The control shown in FIG. 7 or FIG. 8 (switching control from the motor 16 to the electric supercharger 21 in the region Y) is thus realized.

  On the other hand, when YES in step S6, that is, in the third state (electric supercharging region Z), first, in step S14, the motor 16 is driven so that the motor torque Tm becomes maximum (that is, maximum torque Ty). After that (however, the temperature of the battery 18 and the amount of electricity stored in the battery 18 are taken into account), in step S15, as in step S10 described above, it is determined whether or not the operating state is in the non-superchargeable region. If the result is NO, that is, if there is no problem even if the electric supercharger 21 is driven, in step S16, the target torque To is based on the target torque To and the motor torque Tm (in this case, the maximum torque Ty). The torque increment (required supercharging torque) Tbo by the electric supercharger 21 realizing the above is calculated.

  Next, in step S17, the rotational speed (target supercharging rotational speed) Nbo of the turbine 23 of the electric supercharger 21 that achieves the required supercharging torque Tbo is set as in step S12 described above. In step S18, as in step S13 described above, the electric supercharger 21 is feedback-controlled so that the target supercharging speed Nbo is realized. Thus, the control of FIG. 5 (control during transition from region X to region Z) is realized.

  If YES in step S10 or step S15, that is, if a surging or knocking problem occurs and driving of the electric supercharger 21 is not permitted, the continuously variable transmission 11 is shifted down in step S19. As a result, it is possible to compensate for the increase in torque that should be shared by the electric supercharger 21 by increasing (decelerating) the gear ratio of the continuously variable transmission 11, and as a result, corresponds to the target torque To. Driving force is achieved. In this sense, the continuously variable transmission 11 can achieve the target gear ratio (because it can compensate for the target torque increment), and is therefore preferable in this case as compared to a normal automatic transmission with a fixed gear ratio. Become.

  Next, the pre-rotation control of the electric supercharger 21 in step S4 will be described with reference to the flowchart of FIG. First, in step S21, the first contribution value Npre1 is calculated from the charged amount of the battery 18, and in step S22, the second contribution value Npre2 is calculated from the temperature of the battery 18, and in step S23, the temperature of the motor 16 is calculated. The third contribution value Npre3 is calculated, and in step S24, the fourth contribution value Npre4 is calculated from the temperature of the inverter 17, and in step S25, the acceleration frequency (for example, the driver exceeds a predetermined acceleration within a predetermined period). The fifth contribution value Npre5 is calculated from the number of times the acceleration request is made, that is, the number of times the driver depresses the accelerator pedal 32 more than a predetermined depression amount within a predetermined period.

  Here, as illustrated in FIG. 13, the first contribution value Npre1 is increased as the charged amount of the battery 18 is small (however, it is zero when the charged amount is 50% or more). Further, as illustrated in FIG. 14, the second contribution value Npre2 is increased as the temperature of the battery 18 deviates from an appropriate temperature (0 ° to 50 ° in the illustrated example) (zero within the appropriate temperature). . Further, as illustrated in FIG. 15, the third contribution value Npre3 is increased as the temperature of the motor 16 is higher (however, it is zero when the motor temperature is 100 ° C. or lower). Further, as illustrated in FIG. 16, the fourth contribution value Npre4 is increased as the temperature of the inverter 17 is higher (however, when the inverter temperature is 60 ° C. or lower, it is zero). As illustrated in FIG. 17, the fifth contribution value Npre5 is increased as the acceleration frequency is increased (however, the acceleration value is zero when the acceleration frequency is equal to or lower than the predetermined frequency C).

  Next, in step S26, the target pre-rotation speed Npre is set by adding all the five contribution values Npre1 to Npre5. In step S27, the electric supercharger 21 is feedback-controlled so that the target pre-rotation speed Npre is realized. Thus, the control of FIG. 9 (pre-rotation control of the electric supercharger 21 in the region X) is realized.

  Thus, in the present embodiment, as described above with reference to FIG. 2, the torque assist by the motor 16 is used as the main torque raising means, and the torque raising means according to the torque increase by the electric supercharger 21 is used. Since it did in this way, the use frequency of the electric supercharger 21 reduces as much as possible, As a result, the problem of the acceleration responsiveness of the electric supercharger 21 and the problem of surging are suppressed.

  In that case, when the driving force of the motor 16, that is, the assisting force of the motor 16 falls below a predetermined value in the motor assist region Y where only the motor 16 is in the operating state (the temperature of the battery 18 exceeds the predetermined temperature A). When: NO in step S7 of FIG. 10, since the electric supercharger 21 is set in the operating state (steps S11 to S13), for example, the motor for a long time in the motor assist region Y Even when the temperature of the motor 16 and the temperature of the battery 18 are excessively increased due to the continuous driving of the motor 16 and the driving force of the motor 16 is reduced, the torque is secured and the natural intake region X Is sufficiently ensured in the acceleration response at the time of transition from the motor assist region Y to the motor assist region Y (switching control in FIG. 7).

  Similarly, in the motor assist region Y in which only the motor 16 is in the operating state, when the stored amount of the battery 18 falls below a predetermined value (when the stored amount of the battery 18 becomes lower than the predetermined stored amount B: FIG. 10). Since the electric supercharger 21 is also in the operating state (NO in step S8) (steps S11 to S13), for example, the motor 16 is operated for a long time in the motor assist region Y. Even when the amount of power stored in the battery 18 is excessively consumed due to continuous driving and the driving force of the motor 16 is reduced, the torque is secured and the natural assist region X to the motor assist region Y. Sufficient acceleration response at the time of shifting to is ensured (switching control in FIG. 8).

  In the case of the switching control of FIG. 8, when the electric supercharger 21 is in the operating state, the consumption of the storage amount of the battery 18 is reduced by weakening or stopping the driving of the motor 16, Or since it becomes zero, the characteristic and advantageous effect that the amount of electricity stored in the battery 18 is excessively reduced (so-called battery rise) is avoided.

  Furthermore, as described above with reference to FIG. 9 (pre-rotation control of the electric supercharger 21 in the region X), in the natural intake region X in which both the motor 16 and the electric supercharger 21 are in the non-operating state, Since the charger 21 is pre-rotated (step S4 in FIG. 10), the electric supercharger 21 responds promptly at the time of transition from the natural intake region X to the motor assist region Y, and the electric supercharger 21 The torque increase due to will rise well. As a result, for example, the amount of power stored in the battery 18 is excessively reduced at the stage of the natural intake region X before the shift to the assist region Y, and the assist force of the motor 16 is insufficient when the shift to the assist region Y is predicted. When it is predicted that the electric supercharger 21 is in an operating state at the time of transition to the region Y, sufficient torque can be secured, and the acceleration response at the time of transition from the natural intake region X to the motor assist region Y Ensuring sex is sufficiently performed.

  In that case, according to the storage amount of the battery 18 detected at the stage of the natural intake region X, in other words, according to the assist force of the motor 16 predicted when the state shifts to the assist region Y, Since the rotation amount Npre is set (step S21 in FIG. 12), the torque increase of the electric supercharger 21 at the time of transition from the natural intake region X to the motor assist region Y is appropriate according to the assist force of the motor 16 Will stand up.

  Of course, the temperature of the battery 18 in step S22 in FIG. 12, the temperature of the motor 16 in step S23, and the temperature of the inverter 17 in step S24 are also parameters related to the assist force of the motor 16 predicted when the shift to the assist region Y is performed. Needless to say. However, the acceleration frequency in step S25 is a parameter for predicting that the driver's acceleration request is in the near future.

  The embodiment described above is the best mode for carrying out the present invention, but it goes without saying that various modifications can be made without departing from the scope of the claims. For example, in the above embodiment, the continuously variable transmission 11 is used. However, instead of this, a normal automatic transmission may be used. Further, in the above embodiment, when the electric supercharger 21 is activated in the region Y in FIG. 10, the driving of the motor 16 is completely stopped (only the electric supercharger 21 is driven in steps S11 to S13). Alternatively, the motor 16 may be driven weakly with low power.

  Finally, a second example of the control operation of the engine 10 will be described with reference to the flowchart of FIG. However, Steps S31 to S35 are the same as Steps S1 to S5 in FIG. 10 described above, and thus the description thereof will be omitted, and a description will be added after Step S36. When the routine proceeds to step S36, the target torque To is greater than the first predetermined value Two, the throttle opening TVO is set to 100%, and the engine 10 is operating at full throttle.

  The second control example is different from the first control example of FIG. 10 in that the target torque To is compared with the first predetermined value Twot and the second predetermined value Ty in order to determine the region determination X. In this second control example, the target torque To is compared only with the first predetermined value Two, and the natural intake region X and a region where more torque is required Only the discrimination between Y and Z is performed, and in the latter region, the motor is preferentially used, and the electric supercharger is driven only when the required torque cannot be realized by the motor alone. . As a result, when the required torque can be realized only by the motor, it is determined that the vehicle is in the region Y (second state), and if it cannot be determined, the device is determined to be in the region Z (third state). Will be.

  That is, first, in step S36, as shown in the mathematical expression in the figure, the requested assist amount (target assist amount) Past is calculated based on the target torque To (converted to output, that is, power). Here, ηast is transmission efficiency.

  Next, in step S37, the maximum output Pbat of the battery 18 is calculated from the temperature of the battery 18 and the charged amount of the battery 18. Here, as shown in FIG. 19, the battery maximum output Pbat is calculated to be larger as the battery temperature is lower, and is calculated to be larger as the battery storage amount is larger.

  Next, in step S38, the maximum output Pmot of the motor 16 is calculated from the temperature of the motor 16 and the temperature of the inverter 17. Here, as shown in FIG. 20, the maximum motor output Pmot is calculated as a larger value as the motor temperature is lower, and is calculated as a larger value as the inverter temperature is lower.

  Next, in step S39, the maximum motor output Pmot is corrected by the motor / inverter efficiency ηmot, and in step S40, the maximum assist that the motor 16 can output the smaller of the two types of maximum outputs Pbat and Pmot. The amount Pa is adopted.

  In step S41, it is determined whether or not the maximum assist amount Pa is equal to or greater than the required assist amount Past. If YES, that is, if the required assist amount Past can be realized only by driving the motor 16, the output is output in step S42. Then, the motor 16 is driven so that the required assist amount Past becomes the required assist amount Past, and the process proceeds to power train control (control of the engine 10 and the transmission 11).

  On the other hand, if NO in step S41, that is, if the required assist amount Past cannot be realized only by driving the motor 16, the motor 16 is driven so that the output becomes the maximum assist amount Pa in step S43. In step S44, the torque increment (necessary supercharging torque) Tbo by the electric supercharger 21 that realizes the required assist amount Past is calculated based on the required assist amount Past as shown in the mathematical expression in the figure. In step S45, the electric supercharger 21 is controlled so that the required supercharging torque Tbo is realized, and the process shifts to power train control.

  As described above in detail with reference to specific examples, according to the present invention, in the power train provided with the electric supercharger, when the drive of the electric supercharger and the motor is controlled according to the operating state of the engine. The problem of acceleration response of the electric supercharger and the problem of surging can be suppressed. The present invention includes an electric supercharger for increasing the output of an engine and a traveling motor that functions as a power source for the vehicle, and is configured to switch these drives in accordance with the operating state of the engine. It has wide industrial applicability in the technical field of powertrain.

It is a control system diagram of a powertrain according to the best embodiment of the present invention. It is a map which shows the control area | region of the engine of the said power train. It is a time chart at the time of transfer to the area | region Y from the area | region X in the said embodiment. It is a time chart at the time of the transfer from the area | region X to the area | region Y in the past. It is a time chart at the time of transfer to the area | region Z from the area | region X in the said embodiment. It is a time chart at the time of the transition from the area | region X to the area | region Z in the past. It is another example of the time chart at the time of transfer to the area | region Y from the area | region X in the said embodiment. It is another example of the time chart at the time of transfer to the area | region Y from the area | region X in the said embodiment. It is another example of the time chart at the time of transfer to the area | region Y from the area | region X in the said embodiment. It is a flowchart which shows the 1st example of the control action of the said engine. It is a characteristic view used by control of FIG. It is a flowchart which shows the electric supercharger pre-rotation control operation | movement of the said engine. FIG. 13 is a characteristic diagram used in the control of FIG. 12. FIG. 13 is a characteristic diagram used in the control of FIG. 12. FIG. 13 is a characteristic diagram used in the control of FIG. 12. FIG. 13 is a characteristic diagram used in the control of FIG. 12. FIG. 13 is a characteristic diagram used in the control of FIG. 12. It is a flowchart which shows the 2nd example of the control action of the said engine. It is a characteristic view used by control of FIG. It is a characteristic view used by control of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Powertrain 10 Engine 11 Continuously variable transmission 13 Drive wheel 14 Power transmission path 16 Drive motor 17 Inverter 18 Battery 20 Intake passage 21 Electric supercharger 23 Supercharger turbine 25 Throttle valve 32 Accelerator pedal 33 Accelerator opening sensor 34 Water temperature Sensor 35 Engine speed sensor 36 Drive motor temperature sensor 37 Inverter temperature sensor 38 Battery temperature sensor 39 Battery charge amount sensor 40 Control unit X Natural intake area (first state)
Y Motor assist area (second state)
Z Electric supercharging region (third state)

Claims (5)

  A motor that introduces assist torque into the power transmission path from the engine to the drive wheels, an electric supercharger that is provided in the intake passage of the engine and supercharges intake air, and supplies electric power to these motor and electric supercharger A battery, an engine load detecting means for detecting a parameter relating to the engine load, an engine speed detecting means for detecting a parameter relating to the engine speed, and the motor and the electric supercharger according to the detection results of the both detecting means. A power train control device comprising an electric supercharger having control means for controlling the engine load, the engine load detected by the engine load detection means, and the engine speed detected by the engine speed detection means, Target torque setting means for setting the target torque based on the control torque is provided, and the control means is set by the target torque setting means. In a first state where the target torque is equal to or less than a first predetermined value, both the motor and the electric supercharger are deactivated, and the target torque is greater than the first predetermined value and greater than the first predetermined value. In a second state that is less than or equal to a predetermined value of 2, only the motor is in an operating state, and in a third state in which the target torque is greater than the second predetermined value, both the motor and the electric supercharger are in an operating state. A control apparatus for a power train provided with an electric supercharger.   Motor driving force detecting means for detecting a parameter relating to the driving force of the motor is provided, and the control means turns on the electric supercharger when the motor driving force detected by the detecting means in the second state falls below a predetermined value. The control apparatus for a power train provided with the electric supercharger according to claim 1, wherein the control apparatus is configured to be in an operating state.   A battery storage amount detection means for detecting a parameter relating to the storage amount of the battery is provided, and the control means turns on the electric supercharger when the battery storage amount detected by the detection means in the second state falls below a predetermined value. The control apparatus for a power train provided with the electric supercharger according to claim 1, wherein the control apparatus is configured to be in an operating state.   The supercharger pre-rotation means for pre-rotating the electric supercharger in the first state is provided. The powertrain control device with an electric supercharger according to claim 3. 5. The electric supercharger according to claim 4, wherein the supercharger pre-rotation means sets the pre-rotation amount in accordance with the battery charge amount detected by the battery charge amount detection means in the first state. Powertrain control device.

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