JP2010184615A - Control device of transmission system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a transmission system for vehicles which can suppress slip due to excess of driving force transmitted to a front wheel in a 4WD (four wheel drive) vehicle which drives a rear wheel with a motor. <P>SOLUTION: When it is determined that a snow switch 53 is ON by a driving condition determination means 90, the control device does not increase only a front wheel driving force Ffr in order to attain the demanding driving force Fuser, since a rear wheel driving force Frr is restricted by a driving force determination means 100 to not more than the rear wheel maximum driving force Frrmax determined from the rear wheel maximum driving force map of Fig.7 (not shown) regardless whether or not the demanding driving force Fuser is larger than the controlled total driving force Fcontrol, and a rear wheel driving force allocation rate R (actual value) is made a rear wheel driving force allocation rate R (calculated value) determined by a driving force allocation rate determination means 94 from a map of the rear wheel driving force allocation rate of Fig.6 (not shown). Consequently, the slip resulting from the front wheel driving force Ffr becoming excessive can be suppressed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for preventing slipping of drive wheels of a vehicle.

  2. Description of the Related Art Conventionally, a four-wheel drive device for a vehicle that drives a front wheel of a vehicle with a main driving force source and drives a rear wheel with an electric motor has been known. For example, this is the vehicle drive device disclosed in Patent Document 1. The vehicle drive device includes an engine as a main driving force source, and the engine drives the front wheels. The control device for controlling the vehicle drive device disclosed in Patent Document 1 causes a slow vehicle start on a so-called low μ road having a low friction coefficient at which a drive wheel such as a snowy road or a sandy field is likely to slip when the vehicle starts ( In order to prevent vehicle wobbling, a control for advancing the drive timing of the electric motor is executed. Specifically, when the front wheel slip occurs, the control device for the vehicle drive device executes control for advancing the drive timing of the electric motor with respect to the case where the front wheel slip does not occur. .

JP 2008-1000053 A2 Japanese Patent Laid-Open No. 2005-170086 JP 2003-136922 A JP 2002-067723 A

  Since the maximum output is determined for the motor, the rear wheel driving force transmitted from the motor to the rear wheel has an upper limit determined from the maximum output of the motor. In the four-wheel drive vehicle drive device that drives the rear wheels with an electric motor, such as the vehicle drive device, although not described in Patent Document 1, a driver who is usually judged from an accelerator opening degree or the like When the driving force distribution rate of the front wheels and the rear wheels is controlled according to the required driving force, etc., the required rear wheel driving force determined by the driving force distribution rate and the required driving force is the amount of the rear wheel driving force. When the upper limit is exceeded, the driving force corresponding to the required rear wheel driving force exceeding the upper limit of the rear wheel driving force is supplemented by the driving force of the front wheels (front wheel driving force). That is, when the accelerator opening, that is, the required driving force exceeds a certain level, the rear wheel driving force is limited by its upper limit, while the required driving force is exerted exclusively by the increase of the front wheel driving force. In this way, even when the front wheel driving force and the rear wheel driving force are output, the required driving force is exhibited without inducing slip during normal traveling on a dry asphalt road surface or the like. However, although it is unknown, if the required driving force is exerted exclusively by increasing the front wheel driving force as described above in traveling on the low μ road, there is a limit determined from the state of the road surface. There was a possibility of inducing a slip in an attempt to increase the front wheel driving force beyond that.

  Therefore, the control device for a vehicle drive device disclosed in Patent Document 1 can suppress the slack of the vehicle to some extent when starting on the low μ road, while the rear wheel driving force is limited by its upper limit. Considering the case where the required driving force is exerted solely due to the increase in the front wheel driving force, it is considered that the slip cannot be sufficiently suppressed depending on the magnitude of the accelerator opening degree when traveling on the low μ road. It was.

  The present invention has been made in the background of the above circumstances, and its object is to provide a main driving force source for driving a main driving wheel corresponding to the front wheel and a sub driving wheel corresponding to the rear wheel. In the vehicle drive device provided with the electric motor which drives a vehicle, the control device of the vehicle drive device which suppresses the slip by the excessive drive force transmitted to the said main drive wheel is provided.

  In order to achieve such an object, in the invention according to claim 1, (a) a vehicle driving device including a main driving force source for driving main driving wheels of a vehicle and a traveling electric motor for driving auxiliary driving wheels. (B) if it is determined that at least one of the main drive wheel and the sub drive wheel is in a slipping traveling state, the sub drive wheel is transmitted to the sub drive wheel. The driving force is limited to be equal to or less than the maximum driving force of the auxiliary driving wheels determined from the predetermined first relationship, and the distribution ratio of the auxiliary driving wheel driving force to the total driving force of the vehicle is determined in advance. The distribution ratio is determined from the second relationship.

  In the invention according to claim 2, the total driving force is calculated based on a requested driving force requested by a driver based on a distribution ratio of the auxiliary driving wheel driving force and the auxiliary driving wheel maximum driving force. When the upper limit value of the total driving force is exceeded, the calculated upper limit value is set.

  In the invention according to claim 3, (a) the relationship between the accelerator opening, the vehicle speed, and the required driving force, in which the required driving force increases as the accelerator opening increases, is determined in advance. The driving force is determined from the relationship based on the accelerator opening and the vehicle speed.

  The invention according to claim 4 is characterized in that when the snow switch operated by the driver is on, it is determined that the vehicle is in a slipping state that is likely to slip.

  In the invention according to claim 5, (a) the second relationship is a relationship in which the distribution rate of the auxiliary driving wheel driving force decreases as the vehicle speed increases, and (b) the distribution rate is based on the vehicle speed. It is determined.

  In the invention according to claim 6, (a) the first relationship is a relationship between the vehicle speed and the maximum driving force of the auxiliary driving wheel, and (b) the auxiliary driving wheel maximum driving force is determined based on the vehicle speed. It is characterized by being.

  According to the first aspect of the present invention, when it is determined that at least one of the main drive wheel and the sub drive wheel is in a slipping traveling state, the sub drive wheel is transmitted to the sub drive wheel. The driving force is limited to a value equal to or less than the maximum auxiliary driving wheel driving force determined from a predetermined first relationship, and the distribution ratio of the auxiliary driving wheel driving force to the total driving force of the vehicle is determined in advance. Therefore, even if the required driving force is large, the distribution rate of the auxiliary driving wheel driving force is maintained. Therefore, in order to achieve the required driving force, There is no attempt to increase only the main driving wheel driving force transmitted to the main driving wheel. Accordingly, it is possible to suppress the slip caused by the excessive driving force of the main drive wheels.

  According to the second aspect of the invention, the total driving force is calculated based on the required driving force requested by the driver based on the distribution ratio of the auxiliary driving wheel driving force and the auxiliary driving wheel maximum driving force. Further, when the upper limit value of the total driving force is exceeded, the calculated upper limit value is set, so that the total driving force is limited to the upper limit value or less, thereby suppressing the slip. Further, even if the auxiliary driving wheel driving force reaches the auxiliary driving wheel maximum driving force, the distribution ratio of the auxiliary driving wheel driving force is maintained by the limitation of the total driving force.

  According to the invention according to claim 3, (a) the relationship between the accelerator opening and the vehicle speed at which the required driving force increases as the accelerator opening increases and the required driving force is determined in advance. Since the required driving force is determined based on the accelerator opening and the vehicle speed from the relationship, the required driving force can be easily obtained.

  According to the fourth aspect of the present invention, when the snow switch operated by the driver is on, it is determined that the traveling state is likely to slip, so that it is easily and accurately determined whether or not the traveling state is present. it can.

  According to the fifth aspect of the invention, (a) the second relationship is a relationship in which the distribution rate of the auxiliary driving wheel driving force decreases as the vehicle speed increases, and (b) the distribution rate depends on the vehicle speed. To be determined. Therefore, it is possible to easily determine the distribution rate. In addition, since the inertial force of the vehicle increases as the vehicle speed increases, for example, even if the vehicle slips on the low μ road, it can pass through the low μ road with the inertial force. It becomes difficult to receive. Accordingly, reducing the distribution ratio of the auxiliary driving wheel driving force, in other words, increasing the distribution ratio of the main driving wheel driving force is less likely to affect the vehicle behavior, while reducing the total driving force of the vehicle. Can be brought close to the required driving force.

  According to the invention of claim 6, (a) the first relationship is a relationship between the vehicle speed and the maximum driving force of the auxiliary driving wheel, and (b) the auxiliary driving wheel maximum driving force is based on the vehicle speed. Therefore, the maximum driving force of the auxiliary driving wheel can be easily obtained.

  Preferably, the main driving force source includes an engine, a differential mechanism connected between the engine and the main driving wheel, and a first electric motor that controls a differential state of the differential mechanism. And a second electric motor coupled to the main drive wheel so as to be capable of transmitting power.

  Preferably, the first electric motor, the second electric motor, and the traveling electric motor are configured to be able to exchange power with each other. Further, the vehicle drive device is provided with a power storage device capable of transferring power to each of the first electric motor, the second electric motor, and the traveling electric motor. In this way, compared with the case where the main driving force source is only the engine, larger electric power can be supplied to the electric motor for traveling. Further, it is possible to run by driving only the electric motor for driving while the main driving force source is in an inoperative state.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a skeleton diagram illustrating an example of a speed change mechanism that constitutes a part of a vehicle drive device to which the present invention is applied and drives a front wheel of a 4WD vehicle. FIG. 2 is a skeleton diagram illustrating an example of a sub-drive device that constitutes a part of the vehicle drive device separately from the transmission mechanism 10 of FIG. 1 and drives the rear wheels of a 4WD vehicle. FIG. 2 is a diagram illustrating a signal input to an electronic control device provided in the vehicle drive device including the speed change mechanism of FIG. 1 and a signal output from the electronic control device for controlling the vehicle drive device. . It is a functional block diagram explaining the principal part of the control function with which the electronic control apparatus of FIG. 3 was equipped. FIG. 4 is a required driving force map that is a relationship between the accelerator opening, the vehicle speed, and the required driving force, which is stored in advance in the electronic control unit of FIG. 3 and calculates the required driving force. FIG. FIG. 4 is a rear wheel driving force distribution rate map that is a relationship between a vehicle speed and a rear wheel driving force distribution rate that is stored in advance in the electronic control unit of FIG. 3 and calculates a rear wheel driving force distribution rate. 4 is a rear wheel maximum driving force map that is stored in advance in the electronic control unit of FIG. 3 and is a relationship between the vehicle speed and the rear wheel maximum driving force for calculating the rear wheel maximum driving force. FIG. 4 is a flowchart for explaining a main part of a control operation of the electronic control device of FIG. 3, that is, a control operation for determining a front wheel driving force and a rear wheel driving force when traveling on a low μ road.

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

  FIG. 1 is a skeleton diagram illustrating a speed change mechanism 10 as a power transmission device constituting a part of a vehicle drive device 8 (see FIG. 4) to which the present invention is applied. In FIG. 1, a transmission mechanism 10 is an internal combustion engine such as a gasoline engine or a diesel engine in a transaxle (T / A) case 12 (hereinafter referred to as “case 12”) as a non-rotating member attached to a vehicle body. In order from an engine 14 side, a damper 16 that is operatively connected to an output shaft (for example, a crankshaft) of the engine 14 and absorbs pulsation due to torque fluctuations from the engine 14, and the engine 14 via the damper 16 The input shaft 18 that is rotationally driven, the first electric motor M1, the first planetary gear device 20 that functions as a power distribution mechanism, the second planetary gear device 22 that functions as a speed reducer, and the front wheel 40 that is the main drive wheel (FIG. 4). The second electric motor M2 is connected so as to be able to transmit power.

  The speed change mechanism 10 is placed in front of a front-rear wheel drive, that is, a four-wheel drive (4WD) vehicle 6 and is preferably used for driving a front wheel (main drive wheel) 40. In the speed change mechanism 10, the power of the engine 14 includes an output gear 24 as an output rotation member of the speed change mechanism 10 constituting one of the counter gear pairs 32, a counter gear pair 32, a final gear pair 34, a differential gear device (final reduction gear). ) 36 and a pair of axles 38 and the like are sequentially transmitted to the pair of front wheels 40 (see FIG. 4). That is, the main drive device that drives the front wheels (main drive wheels) 40, that is, the main drive force source 23, is composed of the speed change mechanism 10 and the engine 14. As described above, in this embodiment, the input shaft 18 and the engine 14 are operatively connected via the damper 16, and the output shaft of the engine 14 is an output rotating member of the engine 14. The input shaft 18 also corresponds to the output rotating member of the engine 14.

  Both ends of the input shaft 18 are rotatably supported by ball bearings 26 and 28, and one end of the input shaft 18 is connected to the engine 14 via the damper 16 to be driven to rotate by the engine 14. Further, an oil pump 30 as a lubricating oil supply device is connected to the other end, and the oil pump 30 is driven to rotate by rotating the input shaft 18, so that each part of the transmission mechanism 10, for example, the first planetary gear. Lubricating oil is supplied to the device 20, the second planetary gear device 22, the ball bearings 26, 28, and the like.

  The first planetary gear device 20 is a differential mechanism connected between the engine 14 and the front wheel 40. Specifically, the first planetary gear device 20 is a single pinion type planetary gear device, and includes a first sun gear S1, a first pinion gear P1, and a first carrier CA1 that supports the first pinion gear P1 so as to rotate and revolve. A first ring gear R1 that meshes with the first sun gear S1 via the first pinion gear P1 is provided as a rotating element (element).

  The first planetary gear device 20 is a mechanical power distribution mechanism that mechanically distributes the output of the engine 14 transmitted to the input shaft 18, and outputs the output of the engine 14 to the first electric motor M <b> 1 and the output gear 24. To distribute. That is, in the first planetary gear device 20, the first carrier CA1 is connected to the input shaft 18, that is, the engine 14, the first sun gear S1 is connected to the first electric motor M1, and the first ring gear R1 is connected to the output gear 24. Has been. As a result, the first sun gear S1, the first carrier CA1, and the first ring gear R1 can rotate relative to each other, so that the output of the engine 14 is distributed to the first electric motor M1 and the output gear 24, and The first electric motor M1 is generated by the output of the engine 14 distributed to the first electric motor M1, and the generated electric energy is stored or the second electric motor M2 is rotationally driven by the electric energy. For example, a continuously variable transmission state (electric CVT state) is set, and the differential state of the first planetary gear device 20 is controlled by the first electric motor M1, so that the output gear 24 rotates regardless of the predetermined rotation of the engine 14. Functions as an electric continuously variable transmission.

  The second planetary gear unit 22 is a single pinion type planetary gear unit, and includes a second sun gear S2, a second pinion gear P2, a second carrier CA2 that supports the second pinion gear P2 so as to be capable of rotating and revolving, and a second pinion gear P2. A second ring gear R2 that meshes with the second sun gear S2 via a rotation element is provided as a rotating element. The ring gear R1 of the first planetary gear device 20 and the ring gear R2 of the second planetary gear device 22 are an integrated compound gear, and an output gear 24 is provided on the outer periphery thereof.

  In the second planetary gear device 22, the second carrier CA2 is connected to the case 12 which is a non-rotating member to prevent rotation, the second sun gear S2 is connected to the second electric motor M2, and the second ring gear R2 Is connected to the output gear 24. Thus, for example, when the vehicle starts, the second electric motor M2 is rotationally driven, whereby the second sun gear S2 is rotated, and the second planetary gear device 22 decelerates and transmits the rotation to the output gear 24.

  FIG. 2 is a skeleton diagram illustrating a sub-driving device 46 that constitutes a part of the vehicle driving device 8 separately from the speed change mechanism 10 and is preferably used as a sub-driving device of a 4WD vehicle. The sub drive device 46 includes a third electric motor M3 as a sub drive force source and a speed reducer 48 in the housing 45 (see FIG. 4). Then, the output from the third electric motor M3 is a rear wheel 52 which is a pair of auxiliary drive wheels different from the front wheels (main drive wheels) 40 through the reduction gear 48, the differential gear device 49, the pair of axles 50, and the like sequentially. Is transmitted to. As described above, the vehicle drive device 8 of the present embodiment includes the main driving force source 23 that drives the front wheels 40 and the third electric motor M3 (traveling electric motor) that drives the rear wheels 52. That is, in the vehicle drive device 8, the front wheels (main drive wheels) 40 are driven mainly by the output of the engine 14 via the speed change mechanism 10, and the rear wheels (sub drive wheels) 52 are exclusively driven by the third electric motor M3. This is a drive device for a hybrid vehicle that constitutes an electric 4WD (e-4WD) system. The third electric motor M3 corresponds to the traveling electric motor of the present invention.

  The first electric motor M1, the second electric motor M2, and the third electric motor M3 of the present embodiment are all so-called motor generators having a power generation function, but the first electric motor M1 is a generator for generating reaction force (power generation ) At least a function, and the second motor M2 and the third motor M3 have at least a motor (motor) function for outputting the driving force of the vehicle 6. Further, the first electric motor M1, the second electric motor M2, and the third electric motor M3 (see FIG. 2) are configured to be able to exchange power with each other.

  FIG. 3 illustrates a signal input to the electronic control device 80 that is a control device for controlling the vehicle drive device 8 of the present embodiment and a signal output from the electronic control device 80. The electronic control unit 80 includes a so-called microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like, and performs signal processing according to a program stored in the ROM in advance while using a temporary storage function of the RAM. By performing the above, vehicle control such as hybrid drive control relating to the engine 14, the first and second electric motors M1 and M2, and four-wheel drive control including driving of the third electric motor M3 is executed.

The electronic control unit 80 includes a signal indicating the engine water temperature TEMP _W , a signal indicating the shift position P _SH of the shift lever operated by the driver, and the rotational speed of the engine 14 from each sensor and switch as shown in FIG. A signal representing the engine rotational speed _NE , a signal representing the presence / absence of switch operation for setting the motor traveling (EV traveling) mode, and the rotational speed N _OUT of the output gear 24 (hereinafter referred to as “output rotational speed N _OUT ”). ) Corresponding to the vehicle speed V, a signal indicating the foot brake operation, a signal indicating the accelerator opening Acc, which is the operation amount of the accelerator pedal corresponding to the driver's required output, and the throttle valve opening θ of the electronic throttle valve A signal representing _TH , a signal representing the longitudinal acceleration G of the vehicle, a signal representing the wheel speed of each wheel 40, 52, the rotational speed N _M1 of the first electric motor _M1 (hereinafter, A signal representing "a first motor rotation speed N _M1 "), a signal representing a rotation speed N _{M2 of} the second motor _M2 (hereinafter referred to as "second motor rotation speed N _M2 "), and a rotation speed N of the third motor M3. _M3 (hereinafter, "the third electric motor rotation speed _{N M3"} hereinafter) signal representing the power storage device 56 the charging current or discharging current _{I CD} (see Fig. 4) (hereinafter, "charge-discharge current _{I CD"} or "output current I _CD ")), a signal representing the voltage V _BAT of the power storage device 56, the power storage device temperature TH _BAT , the charge / discharge current I _CD , and the remaining charge amount of the power storage device 56 calculated based on the voltage V _BAT. (Charge state) A signal indicating SOC, a signal indicating ON or OFF of the snow switch 53 operated by the driver, and the like are supplied. In the snow switch 53, when at least one of the wheels 40 and 52 easily slips during normal driving on a dry asphalt road surface or the like, for example, the vehicle 6 is low in which a slip such as a snowy road or sandy land easily occurs. The switch is turned on by the driver when traveling on a so-called low μ road having a friction coefficient. For example, when the snow switch 53 is on, the speed ratio γ0 and the engine output of the speed change mechanism 10 are controlled so that slip does not occur more than when the snow switch 53 is off.

A control signal from the electronic control unit 80 to the engine output control unit 58 (see FIG. 4) for controlling the engine output, for example, the throttle valve opening θ of the electronic throttle valve 62 provided in the intake pipe 60 of the engine 14. _Commands a drive signal to the throttle actuator 64 for operating _TH , a fuel supply amount signal for controlling the fuel supply amount to the intake pipe 60 or the cylinder of the engine 14 by the fuel injection device 66, and an ignition timing of the engine 14 by the ignition device 68 An ignition signal to be transmitted, a command signal for instructing the operation of each of the electric motors M1, M2, and M3, an EV mode display signal for displaying that the EV traveling mode is selected, and the like are output.

FIG. 4 is a functional block diagram for explaining the main part of the control function provided in the electronic control unit 80. In FIG. 4, the hybrid control means 82 operates the engine 14 in an efficient operating range, while optimizing the reaction force due to the distribution of the driving force between the engine 14 and the second electric motor M2 and the power generation of the first electric motor M1. Thus, the transmission gear ratio γ0 as an electric continuously variable transmission of the transmission mechanism 10 is controlled. For example, at the traveling vehicle speed V at that time, the target (request) output of the vehicle is calculated from the accelerator opening Acc and the vehicle speed V as the driver's required output amount, and the total required from the target output and the required charging value of the vehicle. The target engine output is calculated, the target engine output is calculated in consideration of transmission loss, auxiliary load, assist torque of the second electric motor M2, etc. so that the total target output can be obtained, and the engine speed at which the target engine output is obtained so that the speed N _E and engine torque T _E to control the amount of power generated by the first electric motor M1 controls the engine 14.

In other words, the hybrid control means 82, to achieve both the drivability and the fuel consumption when the continuously-variable shifting control in a two-dimensional coordinate composed of the output torque (engine torque) T _E of the engine rotational speed N _E and the engine 14 For example, the target output (total target output, request) is set so that the engine 14 is operated along the well-known optimal fuel consumption rate curve (fuel consumption map, relationship) of the engine 14 that is experimentally obtained and stored in advance. determines the target value of the speed ratio γ0 of the transmission mechanism 10, its target value obtained such that the engine torque T _E and the engine rotational speed N _E for generating the engine output necessary to meet the driving force) Thus, the speed ratio γ0 is controlled steplessly within the changeable range of the speed change.

  At this time, the hybrid control means 82 supplies the electric energy generated by the first electric motor M1 to the power storage device 56 and the second electric motor M2 through the inverter 54, so that the main part of the power of the engine 14 is mechanically the output gear 24. However, a part of the motive power of the engine 14 is consumed for power generation of the first electric motor M1 and converted into electric energy there, and the electric energy is supplied to the second electric motor M2 through the inverter 54, The second electric motor M2 is driven and transmitted from the second electric motor M2 to the output gear 24. An electric path from conversion of part of the motive power of the engine 14 into electric energy and conversion of the electric energy into mechanical energy by a device related to the generation of the electric energy until it is consumed by the second electric motor M2 Composed. The power storage device 56 is an electrical energy source capable of supplying power to the first motor M1, the second motor M2, and the third motor M3 and receiving power from the motors M1, M2, and M3. For example, a battery such as a lead storage battery or a capacitor.

The hybrid control means 82, regardless of during or running the vehicle is stopped, the electric CVT function of the transmission mechanism 10, for example, a substantially constant engine speed N _E by controlling the first electric motor speed N _M1 The rotation is controlled at an arbitrary rotation speed. That is, the hybrid control means 82 is a drive capable of transmitting power to the input shaft 18 of the first electric motor M1 operatively connected to the input shaft 18 (that is, the output shaft of the engine 14) via the first planetary gear device 20. By making it function as a device, the engine 14 is driven to rotate by the first electric motor M1. For example, the hybrid control means 82 when raising the engine rotation speed N _E during running of the vehicle, the vehicle speed V (wheel 40) first electric motor speed while maintaining the output rotational speed N _OUT being held to a substantially constant N _M1 to perform the raising of.

The hybrid control means 82 controls the opening and closing of the electronic throttle valve 62 by the throttle actuator 64 for the throttle control, and controls the fuel injection amount and the injection timing by the fuel injection device 66 for the fuel injection control. A command for controlling the ignition timing of the ignition device 68 such as an igniter for control is output to the engine output control device 58 alone or in combination, and the output control of the engine 14 is executed so as to generate the necessary engine output. An engine output control means is functionally provided. For example, the hybrid control means 82 basically drives the throttle actuator 60 based on the accelerator opening Acc from a previously stored relationship (not shown), and increases the throttle valve opening θ _TH as the accelerator opening Acc increases. Throttle control is executed so that Further, the engine output control device 58 controls the opening and closing of the electronic throttle valve 62 by the throttle actuator 64 for throttle control according to the command from the hybrid control means 82, and the fuel injection by the fuel injection device 66 for fuel injection control. The engine torque control is executed by controlling the ignition timing by an ignition device 68 such as an igniter for controlling the ignition timing.

Further, the hybrid control means 82 drives the second electric motor M2 with the electric power from the power storage device 56 in a state where the operation of the engine 14 is stopped and uses only the second electric motor M2 as a driving force source for the front wheels 40 ( EV traveling) can be executed. For example, the EV traveling by the hybrid control means 82 is a comparison of a relatively low output torque T _OUT region, that is, a low engine torque _TE region, or a vehicle speed V, which is generally considered to have a low engine efficiency compared to a high torque region. It is executed at a low vehicle speed range, that is, a low load range.

During this EV traveling, the hybrid control means 82 idles by, for example, setting the first electric motor M1 to a no-load state in order to suppress dragging of the engine 14 that has stopped operating and improve fuel efficiency. maintaining the engine speed N _E at zero or substantially zero as needed by the electric CVT function of the mechanism 10 (differential action). That is, the hybrid control means 82 does not simply stop the operation of the engine 14 during EV traveling, but also stops the rotation of the engine 14.

Moreover, the hybrid control means 82 is functionally provided with an engine start control means for starting the engine 14 while the vehicle is stopped or during EV traveling. For example, the hybrid control means 82, by raising the first electric motor speed N _M1 is energized to the first electric motor M1, i.e., by function of the first electric motor M1 as a starter, complete explosion of the engine rotational speed N _{E 'together} pulled above the predetermined rotational speed N _E' given rotation speed N _E capable of supplying fuel by the fuel injection device 66 at least at autonomously rotate eg idle or rotational speed of the engine rotational speed N _E (injection) The ignition device 68 is ignited to start the engine 14.

  Further, the hybrid control means 82 uses the electric energy from the first electric motor M1 and / or the electric energy from the power storage device 56 by the electric path described above during the engine running using the engine 14 as a driving force source. , And driving the second electric motor M2 to apply torque to the front wheels 40, so-called torque assist for assisting the power of the engine 14 is possible.

  Further, the hybrid control means 82 is in a state in which the transmission mechanism 10 cannot transmit torque, that is, a state in which the power transmission path in the transmission mechanism 10 is interrupted, by causing the first electric motor M1 to rotate freely, that is, idle, with no load. The second electric motor M2 can be in a no-load state and no output from the transmission mechanism 10 can be generated. That is, the hybrid control means 82 can place the transmission mechanism 10 in the neutral state by setting the electric motors M1 and M2 to the no-load state.

The hybrid control means 82 performs 4WD control for driving the rear wheels 52 in addition to driving the front wheels 40 as the main driving wheels. For example, the hybrid control means 82 calculates the front-rear driving torque distribution at the time of starting, sudden acceleration, traveling on a low μ road, etc. based on the accelerator opening Acc, the vehicle speed V, the wheel speed of each wheel, the longitudinal acceleration G, etc. That is, a front wheel driving torque T _F ^* required for driving the front wheels 40 and a rear wheel driving torque T _R ^* required for driving the rear wheels 52 are calculated, and a command for executing engine torque control is issued according to the result. The power is output to the output control device 58 to drive the front wheels 40, and electric energy is supplied to the third electric motor M3 through the inverter 54 to drive the rear wheels 52. The front wheels 40 may be driven only by the output of the engine 14, but may be driven by adding the output of the second electric motor M2 to the output of the engine 14, or may be driven only by the output of the second electric motor M2. May be.

Further, the hybrid control means 82 supplies the electric energy (electric power) generated by the first electric motor M1 by the output of the engine 14 to the third electric motor M3 via the inverter 54. Thus, the first electric motor M1 functions as a power generation power source that becomes a power source by the power generation by the output of the engine 14. At this time, the engine 14 and the first electric motor M1 can be controlled to a free rotational speed without being constrained by the vehicle speed V by the differential action of the first planetary gear unit 20, so that the hybrid control means 82 can control the rear wheel driving torque. the power required to T _R ^* is obtained while securing the power generation amount of the first electric motor M1 for supplying the third electric motor M3, advance such as power generation efficiency of the first electric motor M1 is as high as possible The first motor M1 is operated at the determined first motor rotation speed N _M1 . Furthermore, the hybrid control means 82 may supply the electric power from the power storage device 56 to the third electric motor M3 via the inverter 54 as necessary. For example, when the drive torque distribution to the rear wheels 52 becomes large as in sudden acceleration and the remaining charge SOC of the power storage device 56 is equal to or greater than a predetermined remaining charge, the third electric motor M3 On the other hand, in addition to the electric power generated by the first electric motor M1, electric power is supplied from the power storage device 56 via the inverter 54.

Further, the hybrid control means 82 is the kinetic energy of the vehicle when the vehicle is decelerated or braked with the accelerator off, that is, the reverse driving force transmitted from the drive wheels 40 and 52 to the second electric motor M2 and the third electric motor M3. Accordingly, the second electric motor M2 and the third electric motor M3 are driven to rotate to operate as a generator, and the electric energy, that is, the second electric motor generated current I _M2G and the third electric motor generated current I _M3G are supplied via the inverter 54 to the power storage device 56. It functions as regenerative brake control means for executing so-called regenerative braking.

  By the way, the hybrid control means 82 performs the 4WD control as described above. When traveling on the low μ road, the hybrid control means 82 is suitable for front and rear wheel driving force control for the low μ road traveling, that is, suitable for the low μ road traveling. Perform front and rear wheel drive force control. Therefore, in addition to the hybrid control unit 82, the electronic control unit 80 further includes a traveling state determination unit 90, a required driving force determination unit 92, a driving force distribution rate determination unit 94, and a maximum driving force determination unit 96. , A driving force limit determining means 98 and a driving force determining means 100 are provided.

  The traveling state determination means 90 in FIG. 4 determines whether or not at least one of the front wheels (main driving wheels) 40 and the rear wheels (sub driving wheels) 52 is in a slipping state, that is, a low μ road traveling state. It is determined whether or not. Specifically, whether or not the vehicle is traveling on the low μ road is determined by the operation state of the snow switch 53. That is, the traveling state determination unit 90 determines whether or not the snow switch 53 is on. Then, when the snow switch 53 is on, it is determined that the vehicle is in the slipping traveling state (low μ traveling state). More specifically, the low μ road running state is a running state that easily slips against a predetermined normal running state on a dry asphalt road surface, for example, a friction coefficient such as a snowy road or a sandy land is extremely low. It is a running state on the road surface.

  The requested driving force determining means 92 calculates the requested driving force Fuser requested by the driver. Specifically, a required driving force map that is a relationship between the accelerator opening Acc and the vehicle speed V and the required driving force Fuser as shown in FIG. It is remembered. Then, the required driving force determining means 92 determines the required driving force Fuser based on the accelerator opening Acc and the vehicle speed V from the predetermined required driving force map. The required driving force map in FIG. 5 is such that the required driving force Fuser is in accordance with the driver's intention within the allowable output range of the main driving force source 23 and the third electric motor M3 (sub driving force source). In the required driving force map, the required driving force Fuser increases as the accelerator opening Acc increases.

Further, the required driving force determining means 92 is based on the required driving force Fuser determined by the required driving force determining means 92 and the rear wheel driving force distribution ratio R determined by the driving force distribution ratio determining means 94 described later. Thereafter, when the wheel driving force distribution ratio R is maintained, the required front wheel driving force Ffruser handled by the front wheel 40 and the requested rear wheel driving force Frruser handled by the rear wheel 52 among the requested driving force Fuser are calculated and determined. Specifically, the required rear wheel driving force Frruser is determined (calculated) by the following equation (1), and the required front wheel driving force Ffruser is determined (calculated) by the following equation (2). The requested driving force determining means 92 determines that the requested front wheel driving force Ffruser and the requested rear wheel driving force when the requested driving force Fuser is determined to exceed the control total driving force Fcontrol by the driving force limit judging means 98 described later. Frruser may be determined (calculated).
Frruser = Fuser × R (1)
Ffruser = Fuser−Frruser (2)

The driving force distribution rate determining means 94 determines a distribution rate R of the rear wheel driving force Frr transmitted to the rear wheels 52 (hereinafter referred to as “rear wheel driving force distribution rate R”). More specifically, the rear wheel driving force distribution ratio R is the rear wheel driving force Frr relative to the total driving force Ftotal of the vehicle 6, which is the sum of the front wheel driving force Ffr transmitted to the front wheels 40 and the rear wheel driving force Frr. That is, as shown in the following formula (3), it is represented by the ratio of the rear wheel driving force Frr to the total driving force Ftotal. The rear wheel driving force Frr corresponds to the auxiliary driving wheel driving force of the present invention, and the rear wheel driving force distribution rate R corresponds to the distribution ratio of the auxiliary driving wheel driving force of the present invention.
R = Frr / Ftotal (3)

Specifically, a rear wheel driving force distribution ratio map, which is a relationship between the vehicle speed V and the rear wheel driving force distribution ratio R as shown in FIG. 6, is possible without causing a slip in the low μ road running state. It is experimentally determined by optimizing drivability so that the total driving force Ftotal can be increased as much as possible, and is stored in advance in the driving force distribution rate determining means 94. Then, the driving force distribution rate determining means 94 determines the rear wheel driving force distribution rate R based on the vehicle speed V from the predetermined rear wheel driving force distribution rate map. Note that the rear wheel driving force distribution ratios R1, R2, and R3 shown in the rear wheel driving force distribution ratio map in FIG. 6 have the relationship shown in the following equation (4). That is, the vehicle speed V and the rear wheel driving force distribution rate R in the rear wheel driving force distribution rate map have a relationship that the rear wheel driving force distribution rate R decreases as the vehicle speed V increases. The relationship between the vehicle speed V and the rear wheel driving force distribution ratio R is as follows. As the vehicle speed V is higher as shown in FIG. 6, the rear wheel driving force distribution ratio R may be gradually reduced to R1, R2, and R3. It may be continuously reduced. The rear wheel driving force distribution ratio map in FIG. 6 corresponds to the second relationship of the present invention.
R1>R2> R3 (4)

  The maximum driving force determining means 96 calculates a rear wheel maximum driving force Frrmax that is an upper limit value of the rear wheel driving force Frr. Specifically, the rear wheel maximum driving force map, which is the relationship between the vehicle speed V and the rear wheel maximum driving force Frrmax as shown in FIG. 7, is used to maintain the durability of the third electric motor M3 and optimize the drivability. From the viewpoint, that is, it is experimentally determined so that the maximum output of the third electric motor M3 can be maximized as much as possible without deteriorating the durability of the third electric motor M3, and the drivability can be optimized. Prestored in the driving force determining means 96. Then, the maximum driving force determining means 96 determines the rear wheel maximum driving force Frrmax based on the vehicle speed V from the predetermined rear wheel maximum driving force map. The rear wheel maximum driving force map in FIG. 7 corresponds to the first relationship of the present invention, and the rear wheel maximum driving force Frrmax corresponds to the auxiliary driving wheel maximum driving force of the present invention.

Further, the maximum driving force determination means 96 is based on the rear wheel driving force distribution ratio R determined by the driving force distribution ratio determination means 94 and the rear wheel maximum driving force Frrmax determined by the maximum driving force determination means 96. A control total driving force Fcontrol that is an upper limit value of the driving force Ftotal and a control front wheel driving force Ffrcontrol that is an upper limit value of the front wheel driving force Ffr are calculated. Specifically, the control total driving force Fcontrol is determined by the following equation (5), and the front wheel driving force Ffrcontrol is determined by the following equation (6).
Fcontrol = Frrmax / R (5)
Ffrcontrol = Fcontrol−Frrmax (6)

  The driving force restriction determination unit 98 determines whether or not the total driving force Ftotal (actual value) should be limited to a driving force smaller than the required driving force Fuser (calculated value) calculated by the required driving force determination unit 92. Specifically, the driving force restriction determination unit 98 determines whether or not the requested driving force Fuser exceeds the control total driving force Fcontrol calculated by the maximum driving force determination unit 96, that is, the requested driving force Fuser controls It is determined whether or not the total driving force is greater than Fcontrol. When the required driving force Fuser exceeds the control total driving force Fcontrol, it is determined that the total driving force Ftotal should be limited to a driving force smaller than the required driving force Fuser.

  The driving force determining means 100 is determined to be in the low μ road traveling state by the traveling state determining means 90, and the required driving force Fuser does not exceed the control total driving force Fcontrol by the driving force limit determining means 98. When the determination is made, the rear wheel driving force distribution rate R determined by the driving force distribution rate determining unit 94 is maintained, and the total driving force Ftotal is set as the required driving force Fuser determined by the required driving force determining unit 92. . Specifically, the front wheel driving force Ffr is the required front wheel driving force Ffruser determined by the required driving force determining means 92, and the rear wheel driving force Frr is the required rear wheel driving force Frruser determined by the required driving force determining means 92. Then, the driving force determining means 100 instructs the hybrid control means 82 to drive the front wheels 40 and the rear wheels 52 with the determined front wheel driving force Ffr and rear wheel driving force Frr.

  On the other hand, when the driving force determining unit 100 determines that the traveling state determining unit 90 is in the low μ road traveling state, and the driving force limit determining unit 98 determines that the required driving force Fuser exceeds the control total driving force Fcontrol. If determined, the rear wheel driving force distribution ratio R determined by the driving force distribution ratio determining means 94 is maintained, and the total driving force Ftotal is limited to a driving force smaller than the required driving force Fuser. That is, the total driving force Ftotal is set to the control total driving force Fcontrol determined by the maximum driving force determining means 96. Specifically, in the above case, the driving force determining means 100 uses the front wheel driving force Ffr as the control front wheel driving force Ffrcontrol determined by the maximum driving force determining means 96 and the rear wheel driving force Frr determined by the maximum driving force determining means 96. The rear wheel maximum driving force Frrmax. Then, the driving force determining means 100 instructs the hybrid control means 82 to drive the front wheels 40 and the rear wheels 52 with the determined front wheel driving force Ffr and rear wheel driving force Frr.

  In this way, when the front wheel driving force Ffr and the rear wheel driving force Frr are determined by the driving force determining means 100 and the driving state determining means 90 determines that the vehicle is traveling on the low μ road, Regardless of whether or not the required driving force Fuser is greater than the control total driving force Fcontrol, the rear wheel driving force distribution rate R (actual value) is determined by the driving force distribution rate determining means 94 as shown in FIG. The rear wheel driving force distribution ratio R (calculated value) determined from the map is used. Further, the rear wheel driving force Frr is limited by the driving force determining means 100 to be equal to or less than the rear wheel maximum driving force Frrmax determined from the rear wheel maximum driving force map of FIG.

  FIG. 8 is a flowchart for explaining the main part of the control operation of the electronic control unit 80, that is, the control operation for determining the front wheel driving force Ffr and the rear wheel driving force Frr when traveling on a low μ road. It is repeatedly executed with an extremely short cycle time of about 10 msec.

  First, in a step (hereinafter, “step” is omitted) SA1 corresponding to the travel state determination means 90, whether or not the snow switch 53 is on, that is, the travel mode when the snow switch 53 is on. It is determined whether or not the low μ road running mode is selected. If the determination of SA1 is affirmative, that is, if the snow switch 53 is on, the process proceeds to SA2. On the other hand, when the determination of SA1 is negative, the process proceeds to SA10.

  In SA2 corresponding to the required driving force determining means 92, the required driving force (user required driving force) Fuser requested by the driver (user) is changed to the accelerator opening Acc and the vehicle speed V from the required driving force map of FIG. Based on the calculation. After SA2, the process proceeds to SA3.

  In SA3 corresponding to the driving force distribution rate determining means 94, the rear wheel driving force distribution rate R is calculated and calculated based on the vehicle speed V from the rear wheel driving force distribution rate map of FIG. After SA3, the process proceeds to SA4.

  In SA4 corresponding to the maximum driving force determining means 96, the rear wheel maximum driving force Frrmax is calculated and calculated based on the vehicle speed V from the rear wheel maximum driving force map of FIG. After SA4, the process proceeds to SA5.

  In SA5 corresponding to the maximum driving force determining means 96, based on the rear wheel driving force distribution ratio R calculated in SA3 and the rear wheel maximum driving force Frrmax calculated in SA4, the total control driving force Fcontrol is calculated. And the control front wheel driving force Ffrcontrol are calculated and calculated. Specifically, the control total driving force Fcontrol is calculated by the above equation (5), and the control front wheel driving force Ffrcontrol is calculated by the above equation (6). After SA5, the process proceeds to SA6.

  In SA6 corresponding to the driving force limit determination means 98, it is determined whether or not the required driving force Fuser calculated in SA2 is larger than the total control driving force Fcontrol calculated in SA5. If the determination in SA6 is affirmative, that is, if the required driving force Fuser is greater than the total control driving force Fcontrol, the process proceeds to SA7. On the other hand, if the determination at SA6 is negative, the operation goes to SA8.

  In SA7 corresponding to the driving force determining means 100, a front wheel driving force Ffr and a rear wheel driving force Frr are set. Specifically, the front wheel driving force Ffr is the control front wheel driving force Ffrcontrol calculated in SA5, and the rear wheel driving force Frr is the rear wheel maximum driving force Frrmax calculated in SA4. Then, a command to drive each of the driving wheels 40 and 52 with the set front wheel driving force Ffr and rear wheel driving force Frr is issued.

  In SA8 corresponding to the requested driving force determining means 92, the requested front wheel driving force Ffruser and the requested rear wheel driving force Frruser are the requested driving force Fuser calculated in SA2 and the rear wheel driving force distribution calculated in SA3. Calculated based on the rate R. Specifically, the required rear wheel driving force Frruser is calculated from the equation (1), and the required front wheel driving force Ffruser is calculated from the equation (2). After SA8, the process proceeds to SA9.

  In SA9 corresponding to the driving force determining means 100, a front wheel driving force Ffr and a rear wheel driving force Frr are set. Specifically, unlike SA7, the front wheel driving force Ffr and the rear wheel driving force Frr are the required front wheel driving force Ffruser and the required rear wheel driving force Frruser calculated in SA8, respectively. Then, a command to drive each of the driving wheels 40 and 52 with the set front wheel driving force Ffr and rear wheel driving force Frr is issued.

  In SA10, control of the driving force during the normal running other than the running on the low μ road is performed. For example, in the case where the rear wheel driving force Frr is increased to the rear wheel maximum driving force Frrmax in the predetermined driving force distribution ratio of the front and rear wheels 40, 52, the total driving force Ftotal is insufficient with respect to the required driving force Fuser. Regardless of the total driving force Ftotal with respect to the required driving force Fuser, the driving force is compensated by increasing the front wheel driving force Ffr regardless of the driving force distribution ratio of the front and rear wheels 40 and 52.

  This embodiment has the following effects (A1) to (A7). (A1) According to the present embodiment, when it is determined by the traveling state determining means 90 that the traveling state is likely to slip, whether or not the required driving force Fuser is greater than the total control driving force Fcontrol is determined. First, the rear wheel driving force Frr is limited by the driving force determining means 100 to be equal to or less than the rear wheel maximum driving force Frrmax determined from the rear wheel maximum driving force map shown in FIG. The actual value) is the rear wheel driving force distribution ratio R (calculated value) determined from the rear wheel driving force distribution ratio map of FIG. 6 by the driving force distribution ratio determining means 94, so that the required driving force Fuser is large. Also, the rear wheel driving force distribution ratio R (actual value) is maintained as determined from the rear wheel driving force distribution ratio map, so only the front wheel driving force Ffr is increased in order to achieve the required driving force Fuser. There is no attempt. Accordingly, it is possible to suppress the slip caused by the excessive front wheel driving force Ffr. That is, stable vehicle travel can be realized even when traveling on the low μ road.

  (A2) Also, according to this embodiment, the driving force determining means 100 is determined to be in the low μ road traveling state by the traveling state determining means 90 and the required driving force Fuser is determined by the driving force restriction determining means 98. Is determined to exceed the control total driving force Fcontrol, the total driving force Ftotal is set to the control total driving force Fcontrol determined by the maximum driving force determination means 96. Therefore, in the low μ road running state, the required driving force Even if Fuser is large, the total driving force Ftotal is limited to the upper limit value (control total driving force Fcontrol) or less, thereby suppressing the slip of the vehicle 6, particularly the slip of the front wheel 40. Even if the rear wheel driving force Frr reaches the rear wheel maximum driving force Frrmax, the rear wheel driving force distribution rate R (actual value) is limited to the rear wheel driving force distribution rate map shown in FIG. To be determined from.

  (A3) Further, according to this embodiment, the required driving force Fuser increases as the accelerator opening Acc increases, and the required driving force shown in FIG. 5 is a relationship between the accelerator opening Acc and the vehicle speed V and the required driving force Fuser. A map is predetermined. Then, the required driving force determining means 92 determines the required driving force Fuser based on the accelerator opening Acc and the vehicle speed V from the predetermined required driving force map. Therefore, the required driving force Fuser can be easily obtained.

  (A4) Also, according to this embodiment, when the snow switch 53 is on, the traveling state determining means 90 determines that the traveling state is likely to slip (low μ traveling state). It is possible to easily and accurately determine whether or not the traveling state is likely to slip.

  (A5) Further, according to this embodiment, the rear wheel driving force distribution ratio map shown in FIG. 6 shows that the rear wheel driving force distribution ratio R decreases as the vehicle speed V increases, and the vehicle speed V and the rear wheel driving force distribution ratio. The driving force distribution rate determining means 94 determines the rear wheel driving force distribution rate R based on the vehicle speed V from the rear wheel driving force distribution rate map. Therefore, the rear wheel driving force distribution ratio R can be easily determined, and the optimal driving force distribution to the front and rear wheels 40 and 52 according to the vehicle speed V can be realized. Further, since the inertial force of the vehicle 6 increases as the vehicle speed V increases, even if the vehicle 6 slips on the low μ road, for example, the vehicle 6 can pass through the low μ road with the inertial force. Less susceptible to driving force loss. Therefore, reducing the rear wheel driving force distribution ratio R, in other words, increasing the distribution ratio of the front wheel driving force Ffr hardly affects the vehicle behavior, and controls the total driving force in the high vehicle speed range. It is possible to raise Fcontrol to bring the total driving force Ftotal closer to the required driving force Fuser.

  (A6) According to this embodiment, the rear wheel maximum driving force map shown in FIG. 7 is a predetermined relationship between the vehicle speed V and the rear wheel maximum driving force Frrmax, and the maximum driving force determining means 96 is Since the rear wheel maximum driving force Frrmax is determined based on the vehicle speed V from the rear wheel maximum driving force map, the rear wheel maximum driving force Frrmax can be easily obtained.

  (A7) Moreover, according to the present Example, the 1st electric motor M1, the 2nd electric motor M2, and the 3rd electric motor M3 are comprised so that electric power transmission / reception is mutually possible. Further, since the vehicle drive device 8 is provided with a power storage device 56 capable of transferring power to each of the first electric motor M1, the second electric motor M2, and the third electric motor M3, the main driving force source 23 is provided. Compared with the case where only the engine 14 is used, larger electric power can be supplied to the third electric motor M3. That is, when the rear wheel 52 is driven by the third electric motor M3, sufficient electric power can be supplied to the third electric motor M3, and the rear wheel maximum driving force Frrmax can be set large. In addition, it is possible to run by driving only the third electric motor M3 with the main driving force source 23 being in an inoperative state.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

  For example, in the above-described embodiment, the driving force determining means 100 determines the front wheel driving force Ffr and the rear wheel driving force Frr, but may determine the driving torques of the front and rear wheels 40 and 52, respectively.

  In the above-described embodiment, the traveling state determination unit 90 determines whether or not the traveling state is the low μ road traveling state based on the operation state of the snow switch 53, but by another unit other than the snow switch 53, It may be determined whether the vehicle is traveling on the low μ road.

  In the above-described embodiment, a transmission is not provided in the power transmission path between the engine 14 and the front wheels 40, but a manual transmission or an automatic transmission is provided in the power transmission path. There is no problem. For example, the manual transmission or the automatic transmission is provided in a power transmission path between the output gear 24 and the front wheel 40. Further, when a manual or automatic transmission is provided as described above, the differential state of the first planetary gear device 20 composed of the first electric motor M1 and the first planetary gear device 20 is electrically changed. It is not necessary that the electrical differential unit that can be changed to the above and the transmission are mechanically independent from each other. For example, the electrical difference that can electrically change the differential state as the entire transmission mechanism 10 It is only necessary to have a function for shifting on the principle different from the shift function based on the dynamic function and the electric differential function. The automatic transmission may be a stepped automatic transmission constituted by a planetary gear device or the like, or a continuously variable automatic transmission such as CVT.

  Similarly to the above, a manual transmission or an automatic transmission may be provided in the power transmission path between the third electric motor M3 and the rear wheel 52.

  In the above-described embodiment, the main driving force source 23 is a hybrid driving force source constituted by the engine 14 and the electric motors M1 and M2, but may be a driving force source constituted only by the engine 14. The driving force source may be constituted only by an electric motor. Further, the main driving force source 23 may be a hybrid driving force source constituted by the engine 14 not having the second electric motor M2 and the first electric motor M1. In such a configuration without the second electric motor M2, the third electric motor M3 also functions as the second electric motor M2.

  In the above-described embodiment, the speed change mechanism 10 includes the first planetary gear device 20, the second planetary gear device 22, and the first electric motor M1, but these are not essential. For example, the first planetary gear device 20 is provided. The second planetary gear unit 22 and the first electric motor M1 may not be provided, and a so-called parallel hybrid vehicle in which the engine 14, the clutch, the second electric motor M2, and the front wheels 40 are connected in series may be used. In such a parallel hybrid vehicle, since the forward rotation direction of the second electric motor M2 is equal to the forward rotation direction of the engine 14, the forward rotation direction of the second electric motor M2 is opposite to the configuration of FIG. In addition, since the said clutch between the engine 14 and the 2nd electric motor M2 is provided as needed, the structure where the said parallel hybrid vehicle is not equipped with the clutch can also be considered.

  In the above-described embodiment, the front wheels 40 are driven by the main driving force source 23 and the rear wheels 52 are driven by the third electric motor M3. Conversely, the front wheels 40 are driven by the third electric motor M3 and the main driving is performed. The rear wheel 52 may be driven by the force source 23.

  In the above-described embodiment, by controlling the operating state of the first electric motor M1, the speed ratio γ0 of the speed change mechanism 10 is continuously changed and controlled steplessly within the changeable range of the speed change. However, for example, the gear ratio γ0 may not be continuous, but may be changed stepwise by using the differential action of the first planetary gear device 20.

  In the main driving force source 23 of the above-described embodiment, no clutch is provided between the engine 14 and the first planetary gear device 20, but a power transmission path between the engine 14 and the first planetary gear device 20 is provided. There is no problem even if an engagement device such as a clutch is provided. Similarly, in the power transmission path between the first motor M1 and the first sun gear S1, between the second motor M2 and the output gear 24, and between the third motor M3 and the rear wheel 52, the power An engaging device such as a clutch may be provided in the transmission path.

  Moreover, in the above-mentioned Example, although the 1st planetary gear apparatus 20 is a single planetary, it may be a double planetary. The same applies to the second planetary gear unit 22.

  In the above-described embodiment, the second electric motor M2 is connected to the output gear 24 via the second planetary gear unit 22, but the connecting position of the second electric motor M2 is not limited thereto. A configuration without the second planetary gear unit 22 is also conceivable. In FIG. 1, when the second planetary gear unit 22 is not provided and the second electric motor M2 is directly connected to the output gear 24, the positive rotation direction of the second electric motor M2 is equal to the positive rotation direction of the engine 14. Therefore, the forward rotation direction of the second electric motor M2 is opposite to the configuration in which the second planetary gear device 22 is provided.

  In addition, the second electric motor M2 of the above-described embodiment is connected to the output gear 24 that constitutes a part of the power transmission path from the engine 14 to the front wheels 40 so that the power can be transmitted. In addition to being connected to the transmission path, it can also be connected to the first planetary gear device 20 through an engagement device such as a clutch. The first planetary gear M2 is used instead of the first electric motor M1, and the first planetary gear device 20 is connected. The structure of the speed change mechanism 10 that can control the differential state of the gear device 20 may be used.

6: Vehicle 8: Vehicle drive device 23: Main drive force source 40: Front wheel (main drive wheel)
52: Rear wheel (sub drive wheel)
53: Snow switch 80: Electronic control device (control device)
M3: Third electric motor (traveling motor)

Claims (6)

A control device for a vehicle drive device comprising a main drive force source for driving main drive wheels of a vehicle and a traveling motor for driving auxiliary drive wheels,
If it is determined that at least one of the main drive wheel and the sub drive wheel is in a slipping traveling state, a sub drive wheel driving force transmitted to the sub drive wheel is set to a predetermined first. The distribution is determined to be less than or equal to the maximum driving force of the auxiliary driving wheels determined from the above relationship, and the distribution ratio of the auxiliary driving wheel driving force to the total driving force of the vehicle is determined from the predetermined second relationship. A control device for a vehicle drive device, characterized by: The total driving force is such that the required driving force requested by the driver exceeds the upper limit value of the total driving force calculated based on the distribution ratio of the auxiliary driving wheel driving force and the maximum driving force of the auxiliary driving wheel. In such a case, the calculated upper limit value is used. The control device for a vehicle drive device according to claim 1, wherein: The relationship between the accelerator opening and the vehicle speed at which the required driving force increases as the accelerator opening increases and the required driving force is determined in advance.
The control device for a vehicle drive device according to claim 2, wherein the required drive force is determined based on the accelerator opening and the vehicle speed from the relationship. The control of the vehicle drive device according to any one of claims 1 to 3, wherein when the snow switch operated by a driver is on, the vehicle is determined to be in a slipping-prone traveling state. apparatus. The second relationship is a relationship in which the distribution rate of the auxiliary driving wheel driving force decreases as the vehicle speed increases.
The control device for a vehicle drive device according to any one of claims 1 to 4, wherein the distribution ratio is determined based on the vehicle speed. The first relationship is a relationship between the vehicle speed and the maximum driving force of the auxiliary driving wheel,
The control device for a vehicle drive device according to any one of claims 1 to 5, wherein the maximum drive force of the auxiliary drive wheel is determined based on the vehicle speed.

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