JP2006347408A - System and method for controlling automobile, and automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise operability in starting a vehicle, where the output of an internal combustion engine is transmitted to an automatic transmission via a friction clutch. <P>SOLUTION: The automobile includes: the friction clutch for transmitting/cutting off the driving force between the internal combustion 1 and the automatic transmission 200; a first driving shaft 202 to be driven by the internal combustion engine 1; a second driving shaft 306 which is independent in a driving system from the first driving shaft 202 and is driven by a motor 303; and a power train control unit 100 for cooperatively controlling the friction clutch, the automatic transmission 200, and the motor 303. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device and a control method for controlling an automobile, a transmission, and a motor in combination.

  Automobiles with manual transmissions (hereinafter referred to as MT (Manual Transmission)) have higher transmission efficiency and better fuel efficiency than automatic transmissions using torque converters (hereinafter referred to as AT (Automatic Transmission)). In addition, since the mechanism is simple, there is a merit of light weight and low cost.

  However, since it is necessary for the driver to operate the clutch and accelerator at the same time when starting or changing gears, if these series of operations are not successful, a large shock may occur when starting or shifting the clutch, or engine rotation Smooth running is difficult because the number suddenly increases or decreases. In addition, if the clutch is suddenly engaged while the engine speed is low, there is a demerit that the engine stops.

Therefore, in recent years, a new automatic transmission (hereinafter referred to as AMT) that performs automatic transmission using the MT structure
(Referred to as “Automated Manual Transmisson”). Since this AMT automates clutch operation and gear change operation of a manual transmission, it is a transmission that can eliminate the disadvantages of MT (see, for example, Patent Document 1). Currently, there are AMT types such as a single clutch system, a torque assist system, and a twin clutch system.

JP-A 61-45163

  Although AMT and AT are automatic transmissions, the biggest difference except for the speed change function is that AMT does not have a creep phenomenon due to the action of the torque converter peculiar to AT. As for the creep phenomenon, when the idling speed is high, the creep force is also large (the torque ratio is large due to the characteristics of the torque converter), so a careful accelerator operation is required when starting the engine when the engine is cold. Moreover, since the torque ratio is large when the AT starts, slipping is particularly likely on a low μ road. On the other hand, since the torque ratio is large, there is a great merit that it is easy to start and smooth at extremely low speeds.

  However, since there is no creep phenomenon in AMT, the start can only be made in a half-clutch state. The half-clutch state is subject to multiple factors such as clutch wear state, engine load fluctuation, component variation, and wear, so it is very difficult to always maintain a stable half-clutch state. It also becomes a factor that deteriorates drivability such as speed fluctuations and speed fluctuations at extremely low vehicle speeds.

  Therefore, it is required to add a function equivalent to the creep phenomenon that makes it easy to start without using a half-clutch for AMT.

  SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to improve the drivability at the time of starting, in which the output of an internal combustion engine is transmitted to an automatic transmission via a friction clutch.

  The present invention provides a friction clutch for transmitting and interrupting driving force between an internal combustion engine and an automatic transmission, and the drive system is independent of the first drive shaft driven by the internal combustion engine and the first drive shaft. An automobile having a second drive shaft driven by a motor, and a control device and a control method for cooperatively controlling these vehicles.

  According to the present invention, in the case where the output of the internal combustion engine is transmitted to the automatic transmission via the friction clutch, the drivability at the start can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is an overall configuration diagram of a vehicle in which e-4WD and a torque assist type AMT are combined to form an embodiment of the present invention.

The main configuration is engine 1, AMT 200, first drive shaft 210 driven by engine 1, rear wheel drive unit 300, clutch and speed reducer 301, high voltage generator 302, motor 303, driven by motor 303, The first drive shaft 202 includes a second drive shaft 306, a power train control unit 100, and a power cable 304, which have independent drive systems. Here, an example is shown in which the powertrain control unit 100 performs integrated control of the clutch 301, the motor 303, the high voltage generator 302, the engine 1, and the AMT 200. However, even if the integrated control function is shared by existing control units The invention is applicable.

  As will be described in detail with reference to FIG. 2, the AMT 200 sets an optimum gear position in order to transmit the engine output to the driving wheel (front wheel) with an appropriate driving force.

  Electric power is generated by a high-voltage generator 302 driven by an engine and applied to a motor 303 via a power cable 304. As a result, the motor 303 of the rear wheel drive unit 300 is operated, and the generated power is transmitted to the wheels after the clutch 301 connected to the axle of the rear wheel is connected and decelerated by the speed reducer 301.

  FIG. 2 is an overall configuration diagram of the torque assist type AMT of FIG.

  Engine 1, which is the driving force source 1, engine speed sensor (not shown) for measuring the number of revolutions of engine 1, electronically controlled throttle (not shown) for adjusting the intake air amount (engine torque), fuel amount corresponding to the intake air amount A fuel injection device (not shown) for injecting the engine 1 is provided, and the engine control unit 101 operates the intake air amount, the fuel amount, the ignition timing, and the like to control the torque of the engine 1 with high accuracy. Be able to. The fuel injection device is not limited to a method such as an intake port injection method in which fuel is injected into an intake port or an in-cylinder injection method in which fuel is directly injected into a cylinder. It is advantageous to use an engine of a system that can reduce fuel consumption and has good exhaust performance by comparing engine torque and engine speed. As a driving force source, not only a gasoline engine but also a diesel engine, a natural gas engine, an electric motor, or the like may be used.

  An input shaft clutch input disk 2 is connected to the engine 1, and the torque of the engine 1 is transmitted to the transmission input shaft by engaging and releasing the input shaft clutch input disk 2 and the input shaft clutch output disk 3. 10 can be transmitted and cut off. As the input shaft clutch, a dry single plate method is generally used, but all friction transmission means such as a wet multi-plate clutch and an electromagnetic clutch can also be used. The input shaft 10 includes a first drive gear 4, a second drive gear 5, a third drive gear 6, a fourth drive gear 7, a fifth drive gear 8, a reverse drive gear (not shown), and a seventh drive gear. 201 is provided. For controlling the pressing force (input shaft clutch torque) between the input shaft clutch input disk 2 and the input shaft clutch output disk 3, an actuator 22 driven by hydraulic pressure is used, and this pressing force (input shaft clutch torque) is used. ) Is adjusted so that the output of the engine 1 can be transmitted to and cut off from the input shaft 10.

The first drive gear 4, the second drive gear 5, the third drive gear 6, the fourth drive gear 7, the fifth drive gear 8, and the reverse drive gear are connected to the transmission input shaft 10. The seventh drive gear 201 is fixed to the transmission input shaft 10 so as to be rotatable. A sensor 29 for detecting the rotational speed of the transmission input shaft 10 is provided as input shaft rotational speed detection means.

  Here, from FIG. 1 and FIG. 2, the first drive shaft 210 may be the transmission output shaft 18 itself, but a power transmission member or a power conversion member may be further inserted therebetween.

On the other hand, a first driven gear 12, a second driven gear 13, a third driven gear 14, a fourth driven gear 15, a fifth driven gear 16, and a reverse driven gear (not shown) are freely rotatable on the transmission output shaft 18. The seventh driven gear 202 is fixed to the transmission output shaft 18. Here, the relationship between the input shaft 10 and the output shaft 18 and each drive gear and each driven gear fixed or rotatable may be reversed (the same applies hereinafter). The first driven gear 12 is meshed with the first drive gear 4, the second driven gear 13 is meshed with the second drive gear 5, and the third driven gear 14 is meshed with the first drive gear 4. The fourth driven gear 15 meshes with the fourth drive gear 7, the fifth driven gear 16 meshes with the fifth drive gear 8, and the fourth driven gear 15 meshes with the fifth drive gear 8. The reverse driven gear (not shown) meshes with the reverse drive gear via a reverse gear (not shown), and the seventh driven gear 202 meshes with the seventh drive gear 201.

Between the first driven gear 12 and the second driven gear 13, the first driven gear 12 is engaged with the transmission output shaft 18 or the second driven gear 13 is engaged with the transmission output shaft 18. A first meshing clutch 19 that is a meshing transmission means is provided. Accordingly, the rotational torque transmitted from the first drive gear 4 or the second drive gear 5 to the first driven gear 12 or the second driven gear 13 is transmitted to the first meshing clutch 19, and the first meshing clutch 19. Is transmitted to the transmission output shaft 18.

  Further, between the third driven gear 14 and the fourth driven gear 15, the third driven gear 14 is engaged with the transmission output shaft 18, or the fourth driven gear 15 is engaged with the transmission output shaft 18. A second meshing clutch 20 that is a meshing transmission means is provided. Accordingly, the rotational torque transmitted from the third drive gear 6 or the fourth drive gear 7 to the third driven gear 14 or the fourth driven gear 15 is transmitted to the second meshing clutch 20, and the second meshing clutch 20. Is transmitted to the transmission output shaft 18.

  Further, between the fifth driven gear 16 and the reverse driven gear (not shown), the fifth driven gear 16 is engaged with the transmission output shaft 18 or the reverse driven gear is engaged with the transmission output shaft 18. A third meshing clutch 21 serving as a meshing transmission means is provided. Accordingly, the rotational torque transmitted from the fifth drive gear 8 or the reverse drive gear to the fifth driven gear 16 or the reverse driven gear is transmitted to the third meshing clutch 21 and is shifted via the third meshing clutch 21. It is transmitted to the machine output shaft 18. It is desirable to add a synchronizer mechanism that smoothly adjusts the rotational speed by frictional force to the meshing clutch.

  Thus, in order to transmit the rotational torque of the transmission input shaft 10 to the first meshing clutch 19, the second meshing clutch 20, or the third meshing clutch 21, the first meshing clutch 19 or Any one of the second meshing clutch 20 and the third meshing clutch 21 is moved in the axial direction of the transmission output shaft 18, and the first driven gear 12, the second driven gear 13, and the third driven gear 14 are moved. , The fourth driven gear 15, the fifth driven gear 16, or the reverse driven gear needs to be fastened. In order to move any one of the first meshing clutch 19, the second meshing clutch 20, and the third meshing clutch 21, the shift first actuator 23, the shift second actuator 24, and the select first actuator 25 are moved. , By operating the shift / select mechanism 27 by the select second actuator 26. In this way, the rotational torque of the transmission input shaft 10 is supplied to the drive wheel output shaft 18 via any one of the first meshing clutch 19, the second meshing clutch 20, or the third meshing clutch 21. Can be communicated to.

  A sensor 30 for detecting the rotational speed of the transmission output shaft 18 is provided as output shaft rotational speed detection means.

  The shift first actuator 23, the shift second actuator 24, the select first actuator 25, and the select second actuator 26 may be configured using electromagnetic valves, or may be configured by an electric motor or the like.

  The shift / select mechanism 27 may be constituted by a shifter rail, a shifter fork, or the like, or may be a drum type. Further, the shift / select mechanism 27 may be provided with a position holding mechanism (not shown) for holding the gear position in order to prevent gear loss during traveling.

  The operations of the shift first actuator 23, the shift second actuator 24, the select first actuator 25, the select second actuator 26, the first mesh clutch 19, the second mesh clutch 20, and the third mesh clutch 21. The operation relationship will be described later with reference to FIG.

  Also, assist clutches 203 and 204, which are one type of transmission torque variable means, are provided, the seventh drive gear 201 and the assist clutch input disk 203 are connected, and the transmission input shaft 10 and the assist clutch output disk 204 are connected. The torque of the seventh driven gear 202 can be transmitted to the transmission output shaft 18 by being engaged and engaging the assist clutch input disk 203 and the assist clutch output disk 204.

  For controlling the pressing force (assist clutch torque) between the assist clutch input disk 203 and the assist clutch output disk 204, an actuator 205 driven by hydraulic pressure is used, and this pressing force (assist clutch torque) is adjusted. Thus, the output of the engine 1 can be transmitted and cut off.

  The transmission torque varying means may be constituted by using friction transmission means, or may be constituted by a motor generator or the like. Here, the friction transmission means is means for generating a friction force by the pressing force of the friction surface and transmitting torque, and a representative one is a friction clutch. Examples of the friction clutch include a dry single plate clutch, a dry multi-plate clutch, a wet multi-plate clutch, and an electromagnetic clutch. In this embodiment, the assist clutches 203 and 204 are wet multi-plate clutches that are friction transmission means, but any other transmission torque variable means can be used.

  Thus, the rotational torque of the transmission input shaft 10 transmitted to the transmission output shaft 18 via the drive gear and the driven gear is transmitted to the axle shaft (not shown) via the differential gear (not shown) connected to the transmission output shaft 18. (Not shown).

  The input shaft clutch actuator 22 that generates a pressing force (input shaft clutch torque) between the input shaft clutch input disk 2 and the input shaft clutch output disk 3, and the pressing between the assist clutch input disk 203 and the assist clutch output disk 204. The assist clutch actuator 205 that generates force (assist clutch torque) is controlled by a hydraulic control unit 102 by controlling the current of an electromagnetic valve (not shown) provided in each actuator. The hydraulic pressure of each actuator is controlled by adjusting the stroke amount (not shown), and the transmission torque of each clutch is controlled.

  In addition, the hydraulic control unit 102 controls the currents of solenoid valves (not shown) provided in the select first actuator 25 and the select second actuator 26 to control hydraulic cylinders (not shown) provided in each actuator. The hydraulic pressure of each actuator is controlled by adjusting the stroke amount, and it is selected whether to move the first meshing clutch 19, the second meshing clutch 20, or the third meshing clutch 21.

  Further, the hydraulic control unit 102 controls the currents of the shift first actuator 23, the shift second actuator 24, and the solenoid valve (not shown) provided in each actuator, thereby controlling the hydraulic cylinders provided in each actuator (see FIG. The load for operating the first mesh clutch 19, the second mesh clutch 20, and the third mesh clutch 21 can be controlled by adjusting the hydraulic pressure of each actuator by adjusting the stroke amount (not shown). ing.

  In the present embodiment, hydraulic actuators are used as the shift first actuator 23, the shift second actuator 24, the select first actuator 25, and the select second actuator 26, which are actuators that drive the shift / select mechanism 27. However, you may comprise by the electric actuator by an electric motor etc. Further, instead of the shift first actuator 23 and the shift second actuator 24, one actuator may be used instead of the select first actuator 25 and the select second actuator 26. Further, as a mechanism for operating the first meshing clutch 19, the second meshing clutch 20, and the third meshing clutch 21, it is constituted by a shifter rail, a shifter fork, or the like, or the meshing clutch 19, It is also possible to configure using other means for moving 20,21.

  In the present embodiment, hydraulic actuators are used for the input shaft clutch actuator 22 and the assist clutch actuator 205, but an electric actuator such as an electric motor may be used.

  Further, the engine 1 is configured to control the torque of the engine 1 with high accuracy by operating the intake air amount, fuel amount, ignition timing and the like by the engine control unit 101.

  The hydraulic control unit 102 and the engine control unit 101 are controlled by a powertrain control unit 100. The power train control unit 101, the engine control unit 101, and the hydraulic control unit 102 transmit / receive information to / from each other by the communication means 103.

  In this embodiment, since a hydraulic actuator is used, a hydraulic control unit 102 that controls the hydraulic actuator is used. However, in the case of an electric actuator such as an electric motor, an electric motor control unit is used instead of the hydraulic control unit 102. .

  FIG. 3 shows the driving force characteristics of the vehicle of FIG.

  This figure is an extraction of only the driving torque and vehicle speed of the general general performance diagram. Here, an example of a 5-speed AMT is shown. The driving force from 1st to 5th and the vehicle speed are indicated by solid lines, respectively. Furthermore, the case where the driving force of the motor of the rear wheel is added (motor assist) during the second speed traveling is indicated by a broken line. Although depending on the motor specifications, in this example, the motor assist when driving at the second speed is an example in which the driving force is higher than when the motor assist is not performed at the first speed. Thus, since the motor works to add the driving force, if the motor assist amount is set to 0 (zero) during the second speed traveling, the driving force during the normal second speed traveling is obtained.

FIG. 4 shows the gear position at the start of the vehicle of FIG. 1 and the presence or absence of motor assist after the start. In the table, “◯” indicates motor assist, “Δ” indicates conditionally motor assist, and “x” indicates no motor assist. AMT in FIG. 4 indicates an automatic transmission mode (AMT mode),
MT indicates a manual shift mode (MT mode) in which the driver directly designates the gear position.

  Although the start is performed by the motor drive, when the motor is stopped after the start, the subsequent acceleration force is determined by the gear position. As shown in FIG. 3, if the motor assists, the driving force equivalent to the first speed can be ensured even at the second speed. Therefore, in the AMT mode, it is usually sufficient to start the vehicle with the second speed gear. Further, if the vehicle starts at the second speed, there is no speed change operation from the first speed to the second speed, so that the number of shifts can be reduced and the drivability is improved. However, when a driving force higher than the first speed is required, such as traveling in sand or mud, the first speed start and the assist by the motor are enabled. For the switching, for example, a method using a switch installed near the driver's seat is easy. Further, if the road surface condition is easy to slip, such as a snowy road, it is possible to limit to the 2nd speed or 3rd speed start by a snow mode selection switch, for example. In another embodiment, the motor driving torque shown in FIG. 3 may be limited to adjust the driving torque.

  In the case of starting at 4th speed or 5th speed, there is a high concern that the engine will stop after starting, so it is set not to start.

  On the other hand, in the MT mode, the gear selection at the time of starting is determined by the driver, so motor assist is possible from the 1st to 3rd speeds, but at the 4th and 5th speeds, after starting, Because there is concern about the engine stall, set it so that it will not start.

  In addition, although this example is a case of forward 5 speed shifting, it is not limited to this.

  FIG. 5 shows a motor driving torque determination method when motor assist is performed in the vehicle of FIG.

  The driving torque by the motor assist is variable according to the accelerator opening of the driver. In this example, the characteristics of the accelerator opening and the motor driving torque are set in a proportional relationship, but are not linear. More specifically, the motor drive torque does not change suddenly in the accelerator low opening range and the high opening range, and conversely, the motor drive torque changes greatly in the intermediate opening range. This is to create the same situation as the creep phenomenon of AT cars, and an offset is set so that the driving torque does not become zero even when the accelerator is fully closed during extremely low speed traveling. Thus, when the brake is released, even if the friction clutch is disconnected and the engine power is not transmitted to the transmission, the rear wheels are rotated by the motor driving torque, so that low speed traveling is possible. It is also possible to change the offset amount and characteristics according to the engine operating state, such as when the engine speed is cold.

  FIG. 6 shows a case where the offset amount of the motor driving torque in FIG. 5 is changed.

  FIG. 5 shows the characteristics after the engine warm-up is completed, but this figure shows an example in which the offset amount is made variable according to the engine water temperature. Low water temperature reduces offset compared to high water temperature. Therefore, even when the accelerator is fully closed, the driving force of the rear wheels is variable according to the water temperature. This is because when the engine is cold and the engine is cold, the idle speed is high and the engine output is large, so it is possible to run at low speed only with the engine output, and the motor drive torque when the gear is connected after starting is zero. It becomes. When the water temperature becomes higher than the middle water temperature, the offset becomes larger than zero, so that the driving force of the rear wheels becomes larger than zero and the vehicle can travel at a low speed. In this example, the engine water temperature is taken as an example, but the present invention is not limited to this. For example, parameters such as detected values and estimated values such as outside air temperature, intake air temperature, engine target speed, engine speed, engine oil temperature, mission oil temperature, wheel speed, drive torque value, vehicle speed, road gradient, etc. are set as parameters. However, the same effect can be obtained.

  Even if the lower limit value of the motor driving torque is varied without providing an offset, the same effect can be obtained.

  Further, the same effect can be obtained even if the motor driving torque is adjusted by feedback control of the vehicle speed during the low speed driving to a predetermined vehicle speed.

  FIG. 7 shows a method of setting the timing for connecting the friction clutch in the vehicle of FIG.

This figure shows the relationship between the vehicle speed and the gear position (first speed, second speed, third speed) in the power performance diagram. In the case of the second speed start, if the vehicle speed to which the friction clutch is connected is Akm / h, Br / min that is the engine speed at the second speed is calculated. Therefore, the engine speed is also increased in proportion to the increase in the vehicle speed during traveling by the motor, and the engine speed is controlled to be Br / min at Akm / h. If the friction clutch is connected at this timing, the engine rotation speed (friction clutch input shaft) and the transmission input shaft (friction clutch output shaft) coincide with each other, so that smooth gear connection is possible. The engine speed increase is realized by an engine air amount adjusting device such as an electronic control throttle.

  On the contrary, the same applies to the starting point of the engine speed. For example, the vehicle speed corresponding to the idle speed indicated by the broken line may be calculated, and the friction clutch may be connected at the timing when the vehicle speed is reached. By changing the vehicle speed (timing) at which the clutch is connected according to the idling speed that changes according to the cold engine temperature or the warm-up condition, the clutch can be stably connected regardless of the engine warm-up condition. Smooth gear connection is possible. Further, when starting at the third speed, the vehicle speed is high even if the clutch is connected at the idling speed, so that it is possible to forcibly connect the clutch at the elapsed time after the start.

  In this way, the timing for connecting the clutch is changed according to the vehicle speed and the engine speed in accordance with the gear position at the start and the engine state.

  FIG. 8 shows an operation timing chart when the vehicle of FIG.

  Until time t1 when the brake is depressed (brake SW ON), the vehicle is stopped. At this time, although the gear position is connected to the second speed, the driving force is not transmitted to the front wheels because the power of the internal combustion engine is interrupted by the friction clutch. On the other hand, energization of the motor of the rear wheel is started, and the vehicle speed increases as the motor runs. At time t2 when the accelerator is depressed, the motor output is increased and the vehicle speed is further increased, but the engine remains idling. Thereafter, at the time t3, the rotational speed D of the transmission input shaft substantially matches the engine rotational speed during idling calculated in FIG. 7, and the friction clutch is engaged here.

  FIG. 9 is an operation timing chart showing a state where the vehicle of FIG.

  The vehicle is stopped until time t1 when the brake is depressed (brake SW ON). At this time, the gear position is connected to the second speed, but the power of the internal combustion engine is not transmitted by the friction clutch, so no driving force is applied to the front wheels, but energization to the motor of the rear wheels is started, The vehicle speed increases. Although the vehicle speed is increased by running the motor, the motor output is held at a predetermined value because the accelerator is not stepped on. As a result, the vehicle speed is maintained constant, and the running state is the same as the creep state. At this time, since the transmission input shaft rotational speed has not reached the rotational speed B at which the clutch is connected, the clutch is disengaged, that is, in the neutral state.

  FIG. 10 shows a control flowchart of the powertrain control unit 100 of FIG.

This process is calculated in a 10 ms task. In step 600, it is determined whether the vehicle is stopped. If the vehicle speed is 0 km / h and the brake is ON (a state where the brake is depressed), it is determined that the vehicle is stopped, the clutch is released, and the routine proceeds to step 601. If the vehicle is not stopped, the process is terminated. In step 601, the starting gear position is determined. For example, when the snow mode is selected by the switch SW or when there is a traffic jam, the gear is determined to be 2nd speed or 3rd speed. If it is a power mode, the 1st speed can be selected. In step 602, a brake state change is determined. When a change from the on state to the off state of the brake from the stop state is detected, a motor energization process is performed at a start step 612 to start energization of the rear wheel drive motor or increase the energization amount. However, if the brake state continues ON or continues OFF, or the brake changes from OFF to ON, the process proceeds to step 603. If the brake is not OFF, energization of the motor is stopped or the energization amount is decreased so as to decelerate the vehicle in step 613. If the brake is OFF, it is determined that the vehicle has started. In step 604, the accelerator opening is detected. In step 605, a motor drive torque target value corresponding to the accelerator opening described in FIG. 5 is calculated. Thereafter, in order to determine the timing for engaging the clutch, in step 606, the clutch connection target vehicle speed or the clutch connection target engine speed is determined as described with reference to FIG. In step 607, the actual vehicle speed or the actual engine speed is detected. In step 608, the engine speed is adjusted by controlling the electronic control throttle, the idle speed control valve, and the like so as to coincide with the target engine speed. In step 609, the energization amount to the motor is feedback controlled so as to coincide with the rear wheel motor driving torque determined in step 605. In Step 610, it is determined whether the actual vehicle speed or the actual engine speed matches the clutch connection target vehicle speed or the clutch connection target speed determined in Step 606. If they do not match, this routine ends. If they match, the clutch is connected in step 611.

  This completes the process of driving the rear wheel motor and starting at AMT, but FIG. 10 is an example. In this example, in step 602, energization of the motor is started using the brake ON to OFF as a trigger, but it is not necessary to synchronize with the brake. In step 612, the amount of current supplied to the motor is increased, but if it is increased from the beginning, it is not necessary to synchronize from ON to OFF of the brake.

  FIG. 11 shows the driving force switching between the motor and the engine when the vehicle of FIG. 1 starts. The upper diagram shows the relationship of the required drive torque calculated from the driver's accelerator opening. This allows various requests to be set in the control data. When the driver depresses the accelerator opening from fully closed to AP at the start, the powertrain control unit 100 calculates the required drive torque as T0. Then, the powertrain control unit 100 controls so that the driving force of the motor becomes T1 = T0 when starting. Thereafter, after starting with the motor, the friction clutches 2 and 3 are connected, the engine power is transmitted to the front wheels, the engine drive torque gradually increases from zero, and the motor drive torque increases as T2 = T0. Attenuates from T1 to zero. At this time, the motor drive torque T1 is controlled in synchronism with the engine drive torque T2 until T2 = T0 while maintaining the relationship of T1 = T0-T2.

  Thus, smooth switching without torque step is performed by smoothly switching from motor driving to engine driving.

  As described above, in this embodiment, an electric four-wheel drive technology (hereinafter referred to as e-4WD) that has been put into practical use in recent years is applied to AMT. In the e-4WD front-wheel drive vehicle, the rear wheel is driven by a motor when starting or traveling at an extremely low speed. Therefore, if this function is applied, it is possible to realize a function equivalent to the creep phenomenon even with AMT.

  This eliminates fluctuations in creep force, which is also a weak point of AT (the creep force also changes depending on the idling speed from engine cold to warm-up), and the driving force can be controlled by the motor, regardless of the engine state. At the same time, it is possible to ensure stable running performance, and at the same time, it has functions higher than AT.

  Specifically, the main drive wheel (front wheel) of the vehicle is driven by the output of the internal combustion engine, and the sub drive wheel (rear wheel) different from the main drive wheel is output from the motor with electric power generated by a generator or a storage battery. A gear-type transmission having a plurality of gear trains without using a torque converter, a friction clutch mechanism for transmitting or releasing the power of an internal combustion engine to the gear-type transmission, and the friction clutch mechanism The automatic clutch control device that automatically controls the release and transmission of the gear, and the automatic transmission control device that automatically performs the shift of the gear type transmission. Alternatively, a gear-type transmission having a plurality of gear trains without using a torque converter, a friction clutch mechanism for transmitting or releasing the power of the internal combustion engine to the gear-type transmission, and automatically releasing and transmitting the friction clutch mechanism. It consists of an automatic clutch control device to control.

  When the vehicle starts from a stop state, the friction clutch is changed from the released state to the transmission state after starting by the auxiliary drive wheel motor.

  Further, the timing for switching the friction clutch from the disengaged state to the transmitting state is when the vehicle is at or above a predetermined vehicle speed, or when the accelerator opening is at or above a predetermined opening, or according to the gear position of the gear transmission. The number is within a predetermined range, or after a predetermined time has elapsed after starting.

  Furthermore, when the vehicle is stopped and the internal combustion engine is in an idling state, if the brakes on the wheels are released, the amount of power supplied to the motor for the auxiliary drive wheels is increased. Realize.

  Furthermore, when the vehicle travels at a predetermined speed or less and the accelerator opening is less than the predetermined opening, if the vehicle brake is depressed, the energization amount to the sub drive wheel motor is limited or cut off to a predetermined value or less. Limit the driving torque by the motor.

  Further, the gear position of the gear type transmission at the time of starting the vehicle is set to the second gear or higher. As a result, a creep phenomenon is created by the motor, so that AMT can start smoothly and run at a very low speed similar to AT. In addition, since the speed change shock from the first speed to the second speed can be eliminated by starting the second speed, the number of shifts can be reduced regardless of which AMT system is adopted. As a result, it is possible to provide comfortable driving from the start to the maximum speed.

  As can be seen from the above description, this technique is a feature in the case of combining AMT and e-4WD, and is that the start and extremely low speed running are performed by a motor drive.

  According to the present embodiment, by applying a technique for driving the rear wheels with a motor to the AMT, the AMT can realize a function equivalent to the AT creep phenomenon. As a result, the startability and extremely low speed running in AMT can be made smoother, and therefore, smoothness comparable to that of AT and fuel efficiency equivalent to or better than MT can be achieved.

  Although the above has been described with the torque assist type AMT, the present invention is not limited to this, and the present invention is a single clutch type AMT in which an existing MT start clutch is automated, and a plurality of automatic transmissions each having a shift stage. It is limited to a twin clutch system or the like having an input shaft, in which the output of the internal combustion engine is transmitted to a plurality of input shafts via a plurality of friction clutches, and shifting is achieved by replacing the plurality of friction clutches. It can be applied to all transmissions that do not use a torque converter.

1 is an overall configuration diagram of a vehicle that combines an AMT and an electric 4WD according to an embodiment of the present invention. The whole block diagram of torque assist type AMT of Drawing 1 is shown. The driving force characteristic of the vehicle of FIG. 1 is shown. The gear position at the time of start in the vehicle of FIG. 1 and the presence or absence of the motor assist after start are shown. The motor drive torque determination method when performing motor assist in the vehicle of FIG. 1 will be described. The case where the offset amount of the motor drive torque of FIG. 5 is changed is shown. The setting method of the timing which connects the friction clutch in the vehicle of FIG. 1 is shown. The operation | movement timing chart at the time of 2nd speed start from the stop of the vehicle of FIG. 1 is shown. The operation | movement timing chart which showed the state which transfers to creep driving | running | working from the stop of the vehicle of FIG. The control flowchart of the powertrain control unit 100 of FIG. 1 is shown. Fig. 2 shows driving force switching between a motor and an engine when the vehicle of Fig. 1 starts.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 100 ... Powertrain control unit, 200 ... AMT (automatic manual transmission), 206 ... 2nd drive shaft, 210 ... 1st drive shaft, 303 ... Motor.

Claims (16)

A control apparatus for an automobile having a first drive shaft driven by an output of an internal combustion engine transmitted through a friction clutch and an automatic transmission, and a second drive shaft driven by an output of a motor,
A control apparatus for an automobile having a control unit for cooperatively controlling the friction clutch, the automatic transmission, and the motor when the automobile starts. The automobile control device according to claim 1,
The control unit controls the automatic transmission so that a gear stage different from the first speed is engaged when the vehicle starts, releases the friction clutch before starting the vehicle, and releases the motor when the vehicle starts. A control apparatus for an automobile that drives the motor and then engages the friction clutch. The automobile control device according to claim 1,
In addition to the friction clutch, the automatic transmission, and the motor, the control unit is a vehicle control device that cooperatively controls the internal combustion engine. The vehicle control device according to claim 3,
The control unit controls the vehicle to control the output shaft rotational speed of the internal combustion engine so as to synchronize with the input shaft rotational speed of the automatic transmission accompanying travel by the motor when the friction clutch is engaged. apparatus. The vehicle control device according to claim 2,
When the vehicle is stopped and the internal combustion engine is in an idling state, the control unit increases the energization amount to the motor when the brake of the wheel is released. The vehicle control device according to claim 2,
When the vehicle is traveling at a predetermined speed or less and the accelerator opening is not more than the predetermined opening, the control unit controls the amount of energization to the motor to be less than the predetermined value or interrupts energization when the brake is operated. Control device. The vehicle control device according to claim 2,
The controller is a control device for an automobile that engages the friction clutch when the rotational speed of the input shaft of the automatic transmission accompanying the traveling by the motor is synchronized with the idle rotational speed of the internal combustion engine. The vehicle control device according to claim 3,
The controller is a control device for an automobile that lowers the drive torque of the motor and increases the output torque of the internal combustion engine after engaging the friction clutch. The automobile control device according to claim 1,
The control unit of the automobile controls the automatic transmission so as to engage the first gear when the automobile starts in a manual transmission mode in which the driver manually changes gears. The automobile control device according to claim 1,
The control unit is configured such that when the vehicle is at or above a predetermined vehicle speed, when the accelerator opening is at or above a predetermined opening, when the shaft speed according to the gear position of the automatic transmission is within a predetermined range, or after starting A control apparatus for an automobile that engages the friction clutch when the elapsed time of the motor reaches a predetermined time. A method for controlling an automobile having a first drive shaft driven by an output of an internal combustion engine transmitted through a friction clutch and an automatic transmission, and a second drive shaft driven by an output of a motor,
The automatic transmission is controlled to engage a gear stage different from the first gear when the vehicle starts, the friction clutch is released before the vehicle starts, the motor is driven when the vehicle starts, and then A method for controlling an automobile in which the friction clutch is engaged. An internal combustion engine;
An automatic transmission,
A friction clutch for transmitting and interrupting driving force between the internal combustion engine and the automatic transmission;
A first drive shaft driven by the output of the internal combustion engine being transmitted via the friction clutch and the automatic transmission;
And a second drive shaft driven by the output of the motor. The automobile according to claim 12,
An automobile having a control device for cooperatively controlling the friction clutch, the automatic transmission, and the motor when the automobile starts. The automobile according to claim 12,
The motor is an automobile driven by electric power generated by a generator driven by the internal combustion engine. The automobile according to claim 12,
A storage battery for storing electric power generated by a generator driven by the internal combustion engine;
The motor is an automobile driven by the storage battery. The automobile according to claim 12,
The automatic transmission has a plurality of input shafts, and the output of the internal combustion engine is transmitted to the plurality of input shafts via the plurality of friction clutches.

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