JP2009035212A - Driving device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a motor from being locked by a simple structure. <P>SOLUTION: This driving device for a vehicle comprises the motor 4 capable of transmitting driving torque to a drive wheel, and a torque convertor 31 as fluid coupling disposed in a transmission path of the driving torque from the motor 4 to the drive wheel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle drive device that drives drive wheels with a motor.

In the vehicle drive device disclosed in Patent Document 1, a generator is driven by an engine, electric power generated by the generator is supplied to a motor, and torque of the motor is transmitted to drive wheels via a reduction gear. ing.
JP 2006-187090 A

By the way, when the drive shaft of the motor and the reduction gear are directly connected as in the device as in Patent Document 1, an external force is applied to the drive wheel when starting on a slope or when exiting from a hole. When the driving wheel is locked, the driving shaft of the motor also does not rotate, and a so-called motor lock is obtained. In this case, since the drive shaft of the motor does not rotate even though the drive current is supplied to the motor, the current continues to flow in a specific phase, and the motor generates heat.
An object of the present invention is to prevent motor lock with a simple configuration.

  In order to solve the above-mentioned problems, the present invention arranges a fluid coupling in a transmission path of driving torque from a motor to driving wheels.

  According to the present invention, by disposing the fluid coupling, even if the drive wheel is locked, the rotation of the drive shaft of the motor is allowed, and the motor lock can be prevented with a simple configuration.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
(Constitution)
FIG. 1 is a schematic configuration diagram when the present invention is applied to a four-wheel drive vehicle.
As shown in FIG. 1, in the vehicle of this embodiment, left and right front wheels 1L and 1R are main drive wheels driven by an engine 2 which is a heat engine (internal combustion engine), and left and right rear wheels 3L and 3R are motors. 4 is a driven wheel that can be driven by the motor 4. Here, the motor 4 is an AC motor.

  For example, a main throttle valve and a sub-throttle valve are interposed in the intake pipe line of the engine 2. The throttle opening of the main throttle valve is adjusted and controlled according to the amount of depression of the accelerator pedal. The sub-throttle valve uses a step motor or the like as an actuator, and the opening degree is adjusted and controlled by a rotation angle corresponding to the number of steps. Therefore, by adjusting the throttle opening of the sub-throttle valve to be equal to or less than the opening of the main throttle valve, the engine output torque can be reduced independently of the driver's operation of the accelerator pedal. That is, the adjustment of the opening degree of the sub-throttle valve is the driving force control that suppresses the acceleration slip of the front wheels 1L, 1R by the engine 2.

  The output torque Te of the engine 2 is transmitted to the left and right front wheels 1L, 1R through the transmission and the reference gear 5. Further, a part of the output torque Te of the engine 2 is transmitted to the generator 7 via the endless belt 6, so that the generator 7 reaches the rotation speed Ne (hereinafter referred to as engine rotation speed) Ne. It rotates at a rotational speed (hereinafter referred to as generator rotational speed) Ng multiplied by the pulley ratio.

  The generator 7 becomes a load on the engine 2 in accordance with the field current Ifg adjusted by the 4WD controller 8, and generates power in accordance with the load torque. The magnitude of the power generated by the generator 7 is determined by the magnitudes of the generator rotational speed Ng and the field current Ifg. The generator speed Ng of the generator 7 can be calculated from the engine speed Ne of the engine 2 based on the pulley ratio.

FIG. 2 is a diagram showing the structure of the field current drive circuit of the generator 7.
As shown in FIG. 2 (a), this circuit applies a configuration in which a constant voltage power source such as a 14V battery 7a of a vehicle and an output voltage of the generator itself are selected as a field current power source. Is connected to the field coil 7b to switch the transistor 7c. In this case, when the generator output is lower than the battery voltage Vb, the battery voltage Vb becomes a power source for the field coil 7b in a separate excitation region, the generator output increases, and the output voltage Vg is equal to or higher than the battery voltage Vb. Then, the output voltage Vg of the generator is selected as a self-excited region and becomes a power source for the field coil 7b. That is, since the field current value can be increased by the power supply voltage of the generator, the generator output can be significantly increased.

In the field current drive circuit, only the 14V battery 7a of the vehicle (only the separate excitation region) may be applied as the field current power source as shown in FIG. 2 (b).
The electric power generated by the generator 7 can be supplied to the motor 4 via the junction box 10 and the inverter 9. The drive shaft of the motor 4 can be connected to the rear wheels 3 </ b> L and 3 </ b> R via a drive force transmission unit (reduction gear) 30.

FIG. 3 shows the configuration of the driving force transmission unit 30.
As shown in FIG. 3, the driving force transmission unit 30 is provided with a torque converter (fluid coupling) 31 between the drive shaft 4a of the motor 4 and the reduction gear unit 32, and the reduction gear unit 32 and the rear wheels 3L, 3R. A differential gear 33 and a clutch 34 are provided between the drive shaft 3a.
The torque converter 31 has the same structure as that generally used for A / T. That is, while the rotational speed of the motor 4 is low, the drive force from the drive shaft 4a of the motor 4 is reduced. When the rotational speed of the motor 4 increases without being transmitted to the gear portion 32 side, the driving force from the drive shaft 4a of the motor 4 is transmitted to the reduction gear portion 32 side to start the vehicle.

  The torque converter 31 is a so-called lock-up torque converter that includes a lock-up mechanism (lock-up piston or lock-up clutch) 31a. The lock-up mechanism 31a is activated (fastened) during normal running, that is, when the vehicle speed is below a predetermined value, the lock-up mechanism 31a is in a released state (non-operating state), and the vehicle speed is increased to a predetermined value or more. In this case, it is in a fastening state (operating state).

FIG. 4 shows the relationship between the vehicle speed and the operating state of the lockup mechanism.
As shown in FIG. 4, when traveling forward, the lockup mechanism changes from a non-released state or an operating state (OFF) to a fastening state or an operating state (ON) after a certain speed.
In this vehicle, the torque converter in the A / T transmission also has a lock-up mechanism. As shown in FIG. 3, the lock-up mechanism 31a in the torque converter 31 is a lock-up mechanism of the torque converter on the transmission side. The operation state is controlled via a hydraulic system 41 by a control unit that hydraulically controls (lock-up piston or lock-up clutch).

  By such a lock-up mechanism 31a, when the rear shaft torque (torque of the rear wheels 3L and 3R) is required, such as when starting or rolling back (rolling back when moving forward), the torque is released by entering the release state. The torque is amplified by the converter 31 and transmitted to the reduction gear unit 32 side. During normal traveling (during high-speed traveling), the engagement state is established, so that the drive shaft of the motor 4 and the reduction gear unit 32 are The relationship is directly connected, and the torque of the motor 4 is transmitted to the reduction gear portion 32 side.

Further, in the torque converter in the A / T transmission, the input (engine rotation) does not reverse, but the motor 4 reverses when the vehicle travels backward. That is, the motor 4 is rotated forward and backward in response to forward and backward movement of the vehicle.
In this case, due to the structure of the torque converter 31, the input from the reversely rotating motor 4 cannot be transmitted to the output (reduction gear unit 32 side). Correspondingly, when the vehicle travels backward, the lockup mechanism 31a is operated. That is, the drive shaft of the motor 4 and the reduction gear portion 32 are directly connected.

The reduction gear unit 32 reduces the rotational speed of the motor 4 transmitted via the torque converter 31 by the reduction gear and transmits the reduced speed to the differential gear 33 and the clutch 34 side.
The driving force of the motor 4 is transmitted to the driving shaft 3a of the rear wheels 3L and 3R via the differential gear 33 and the clutch 34.
The clutch 34 is an electromagnetic clutch that is released when the rotational speed of the motor 4 exceeds a predetermined value and releases the rotation input to the clutch 34 to the drive shaft 3a of the rear wheels 3L and 3R. is there. When the clutch 34 is engaged, the four-wheel drive state is established. When the clutch 34 is released, the four-wheel drive is released and the two-wheel drive state is established with the left and right front wheels 1L, 1R.

Here, the clutch 34 is engaged and disengaged according to a command from the 4WD controller 8. Further, when the rotational speed of the motor 4 becomes a predetermined value or more, the motor torque of the motor 4 is also reduced. Here, the electromagnetic clutch is, for example, a wet multi-plate clutch, a powder clutch, or a pump-type clutch.
The clutch 34 can also be configured as a one-way clutch. In this case, when the rotation input to the clutch 34, that is, when the rotational speed of the motor 4 becomes high, the clutch 34 is released and the rotation input to the clutch 34 is driven to the drive shaft 3a of the rear wheels 3L and 3R. Will not be transmitted.

Further, the clutch 34 releases transmission of rotation input to the clutch 34 to the drive shaft 3a of the rear wheels 3L, 3R when the rotational speed of the drive shaft 3a of the rear wheels 3L, 3R becomes high. It can also be configured as a centrifugal clutch.
In the junction box 10, a relay for connecting and disconnecting the inverter 9 and the generator 7 is provided. In a state where this relay is connected, DC power supplied from the generator 7 via a rectifier (not shown) is converted into three-phase AC in the inverter 9 to drive the motor 4.

The junction box 10 is provided with a generator voltage sensor that detects a generated voltage and a generator current sensor that detects a generated current that is an input current of the inverter 9. These detection signals are sent to the 4WD controller 8. Is output. Further, a resolver is connected to the drive shaft of the motor 4 and outputs a magnetic pole position signal θ of the motor 4.
Each wheel 1L, 1R, 3L, 3R is provided with a wheel speed sensor 27FL, 27FR, 27RL, 27RR. Each wheel speed sensor 27FL, 27FR, 27RL, 27RR outputs a pulse signal corresponding to the rotation speed of the corresponding wheel 1L, 1R, 3L, 3R to the 4WD controller 8 as a wheel speed detection value.

  The 4WD controller 8 includes an arithmetic processing unit such as a microcomputer, for example, and includes wheel speed signals detected by the wheel speed sensors 27FL to 27RR, output signals of voltage sensors and current sensors in the junction box 10, and motors. The output signal of the resolver connected to 4 and the accelerator opening corresponding to the amount of depression of an accelerator pedal (not shown) are input.

FIG. 5 shows the configuration of the 4WD controller 8.
As shown in FIG. 5, the 4WD controller 8 includes a target motor torque calculation unit 8A, a generator supply power calculation unit 8B as a motor required power calculation unit, a generated current command calculation unit 8C, and a generator control as a generator control unit. 8D, a motor control unit 8E as a load fixing means, a TCS control unit 8F, and a clutch control unit 8G.
The target motor torque calculation unit 8A is configured to calculate the required driving force of the rear wheels 3L and 3R as the driven wheels, for example, the wheel speed difference between the front and rear wheels calculated based on the wheel speed signal of the four wheels, and the accelerator pedal opening signal. From this, the motor torque command value Tt is calculated.

The generator supply power calculation unit 8B calculates the generator supply power Pg based on the following equation based on the torque command value Tt and the motor rotation speed Nm.
Pg = Tt × Nm / Иm (1)
Here, Иm is the inverter efficiency. That is, the generator supply power Pg has a value that is higher by the inverter efficiency Иm than the power Pm (= Tt × Nm) required for the motor, which is obtained by the product of the torque command value Tt and the motor rotation speed Nm.
The generated current command calculation unit 8C calculates the following equation based on the generator supply power Pg calculated by the generator supply power calculation unit 8B and the generated voltage command value Vdc ^* calculated by the motor control unit 8E described later. Based on the generated current command value Idc ^* .
Idc ^* = Pg / Vdc ^* (2)

FIG. 6 is a block diagram showing details of the generator control unit 8D that performs power generation control of the generator 7.
The generator control unit 8D includes a P control unit 101, an I control unit 102, an FF control unit 103, a control amount adding unit 104, and a field control unit 105, and determines a field voltage PWM duty ratio C1. Thus, the field current Ifg of the generator 7 is PWM-controlled.
The P control unit 101 performs P control based on the deviation between the generated current command value Idc ^* calculated by the equation (2) and the actual generated current value Idc. First, the deviation between the generated current command value Idc ^* and the actual generated current value Idc is multiplied by a predetermined gain. Then, in order to make the gain sensitivity constant with respect to fluctuations in the rotational speed of the generator, this value is multiplied by the reciprocal of the generator rotational speed Ng, and this is used as a control amount Vp in P control, which will be described later. To 104.

The I control unit 102 performs I control based on the deviation between the generated current command value Idc ^* and the actual generated current value Idc calculated by the equation (2). That is, the deviation between the generated current command value Idc ^* and the actual generated current value Idc is integrated. Here, the integral value has an upper limit value and a lower limit value. Then, like the P control, this integral value is multiplied by the reciprocal of the generator rotational speed Ng, and this is output to the control amount adding unit 104 described later as the control amount Vi in the I control.

As shown in FIG. 7, the FF control unit 103 refers to the generator characteristic map for each rotation speed stored in advance, and generates power by feedforward based on the generated voltage command value Vdc ^* and the generated current command value Idc ^*. The PWM duty ratio D1 of the machine field voltage is obtained. In FIG. 7, curves a1 to a4 are locus of operating points when the field voltage PWM duty ratio D1 is fixed in the self-excited region of the generator 7 and the load of the generator 7 is gradually changed. Curves a1 to a4 show the difference in duty ratio D1.

Then, based on the PWM duty ratio D1 and the generated voltage command value Vdc ^* , the control amount Vff in the FF control is calculated based on the following equation and output to the control amount adding unit 104.
Vff = D1 × Vdc ^* (3)
In the present embodiment, the case where the control amount Vff is calculated based on the PWM duty ratio D1 and the generated voltage command value Vdc ^* has been described. However, the present invention is not limited to this, and the field of the generator 7 is not limited thereto. The control amount Vff may be calculated based on the current If and the field coil resistance Rf.

In this case, first, calculates the required power generation voltage V0 and the required generated current I ₀ required to the generator 7 with reference to pre-stored map and the motor rotation speed Nm and the torque command value Tt, Based on these As shown in FIG. 8, the necessary field current If ₀ is calculated with reference to the field current characteristic map of the generator 7 for each rotation speed stored in advance. Then, the control amount Vff may be calculated by Vff = If ₀ × Rf based on the necessary field current If ₀ calculated in this way.

The control amount adding unit 104 adds the control amount Vp, the control amount Vi, and the control amount Vff, and outputs this to the field control unit 105 as a voltage Vf applied to the field coil.
The field control unit 105 determines whether or not the actual power generation voltage value Vdc is equal to or less than the battery voltage Vb as the field current power source of the generator 7. If Vdc ≦ Vb, the field control unit 105 determines the field based on the following equation (4). The duty ratio C1 of the magnetic voltage PWM is calculated.
C1 = Vf / Vb (4)
On the other hand, when Vdc> Vb, field voltage PWM duty ratio C1 is calculated based on the following equation (5).
C1 = Vf / Vdc (5)
Then, the field current Ifg of the generator 7 is controlled according to the duty ratio C1 calculated in this way.

That is, in this generator control unit 8D, the generator operating point for realizing the generator supply power Pg determined from the torque command value Tt is designated by feedforward, and the deviation between the generated current command value Idc ^* and the actual generated current value Idc is specified. Is fed back by PI compensation to cause the actual generated current value Idc to follow the generated current command value Idc ^* . Thereby, the field current Ifg of the generator 7 is controlled so as to supply the inverter 9 with the electric power according to the request of the motor 4.
Here, PI compensation is applied as a control method used for feedback control. However, the present invention is not limited to this, and any control method that stabilizes the system may be used.

FIG. 9 is a block diagram showing details of the motor control unit 8E that controls the motor 4 by the inverter 9. As shown in FIG.
The motor control unit 8E includes an Id / Iq command value calculation unit 201, a Vd / Vq command value calculation unit 202, a Vdc ^* command value calculation unit 203, a 2-phase / 3-phase conversion unit 204, and a PWM control unit 205. And a field current command value calculation unit 206 and a field magnetic flux calculation unit 207. The torque command value Tt calculated by the target motor torque calculation unit 8A is input and the actual motor torque T is converted into the torque command value Tt. The three-phase power element of the inverter 9 is subjected to switching control so that

In the Id, Iq command value calculation unit 201, based on the torque command value Tt and the motor rotation speed Nm, a d-axis (magnetic flux component) current and a q-axis (torque) for outputting torque that matches the torque command value Tt Component) Command values Id ^* and Iq ^* with current are calculated and output to the Vd and Vq command value calculation unit 202.
In the Vd, Vq command value calculation unit 202, current command values Id ^* , Iq ^* input from the Id, Iq command value calculation unit 201, the motor rotation speed Nm, and a field magnetic flux calculation unit 207, which will be described later, are input. motor parameters (inductance Ld, Lq, field magnetic flux [Phi) based on the, the d-axis current value Id and the d-axis current command value Id ^* d-axis voltage for the command value Vd ^*, the q-axis current value Iq The q-axis voltage command value Vq ^* for obtaining the q-axis current command value Iq ^* is calculated.

The Vdc ^* command value calculation unit 203 calculates the generated voltage command value Vdc ^* based on the voltage command values Vd ^* and Vq ^* calculated by the Vd, Vq command value calculation unit 202, and the generator shown in FIG. Output to the control unit 8D.
Vdc ^* = 2√2 / √3 · √ (Vd ^{* 2} + Vq ^{* 2} ) (6)
Further, in the two-phase / three-phase conversion unit 204, the dq-axis voltage command values Vd ^* and Vq ^* calculated by the Vd and Vq command value calculation unit 202 are converted to the U phase of the three-phase coordinate system which is a three-phase sine wave command value. The voltage command value Vu ^* , the V-phase voltage command value Vv ^* , and the W-phase voltage command value Vw ^* are converted and output to the PWM control unit 205.

The PWM control unit 205 calculates the PWM command by comparing with the triangular wave based on the three-phase sine wave command value input from the two-phase / three-phase conversion unit 204, and outputs a switching signal to be output to the inverter 9. Generate. The inverter 9 generates a PWM wave voltage corresponding to the switching signal and applies it to the motor 4, thereby driving the motor 4.
At the time of the triangular wave comparison, in this embodiment, the generated voltage command value Vdc ^* which is a DC voltage command value is used to normalize the sine wave amplitude by Vu ^* / Vdc ^{* in} the case of the U phase, for example. A U-phase switching signal is output by comparing the wave command value with the triangular wave. Thereby, the impedance of the inverter viewed from the generator is fixed for each combination of the torque command value Tt and the motor rotation speed Nm. That is, this corresponds to fixing the pulse width of the PWM wave voltage for each torque command value Tt and motor rotation speed Nm.

The field current command value calculation unit 206 calculates a field current command value If ^* based on the motor rotation speed Nm and outputs it to the field magnetic flux calculation unit 207. The field magnetic flux calculation unit 207 The magnetic flux is calculated and output to the Vd, Vq command value calculation unit 202 described above.
Therefore, in this motor control unit 8E, the operation of the inverter is fixed to the required motor output with a switching pattern performed when the required voltage is satisfied.

Further, the TCS control unit 8F in FIG. 5 performs a known method based on an engine generated drive torque demand signal Tet from an unillustrated engine torque controller (ECM), the rotational speeds V _FR and V _{FL of} the left and right front wheels, and the vehicle speed V. Thus, the front wheel traction control control is performed by returning the engine generated drive torque demand signal Te to the ECM.
The clutch control unit 8G controls the state of the clutch 34, and controls the clutch 34 to be in a connected state while determining that it is in the four-wheel drive state.

(Operation and action)
Operation and action are as follows.
Now, it is assumed that the vehicle is determined to be in the four-wheel drive state, and the motor torque command value Tt is calculated based on the wheel speed and the accelerator pedal opening. In this case, the generator control unit 8D performs PI control on the deviation between the generated current command value Idc ^* calculated based on the motor torque command value Tt and the generated current value Idc, and the generated current value Idc is generated. Field current Ifg of generator 7 is controlled so as to follow current command value Idc ^* .

Then, the motor control unit 8E calculates a three-phase sine wave command for switching control of the three-phase power element of the inverter 9 based on the torque command value Tt and the motor rotation speed Nm. Based on this, a PWM command is calculated and output to the inverter 9.
At this time, the motor control unit 8E calculates the generated voltage value Vdc from the U-phase voltage command value Vu, and outputs this to the generator control unit 8D. Further, the motor control unit 8E obtains the U-phase current value Iu based on the dq-axis current command values Idr and Iqr, calculates the generated current value Idc from the U-phase current value Iu, and supplies this to the generator control unit 8D. Output. Then, the generator control unit 8D executes power generation control using the generated voltage value Vdc and the generated current value Idc calculated by the motor control unit 8E.

Further, in this vehicle, since the lockup mechanism 31a of the torque converter 31 is released at the time of starting, the rotation speed of the motor 4 increases due to the increase in the motor torque command value Tt. As a result, the drive torque from the motor 4 amplified by the torque converter 31 is output to the rear shaft (the drive shaft 3a of the rear wheels 3L, 3R) in the rotation stopped state, and the vehicle starts to start, and the subsequent low speed During traveling, the torque amplified by the torque converter 31 (drive torque from the motor 4) is output to the rear shaft.
When the rotational speed of the motor 4 is increased to some extent, that is, when the vehicle is traveling at a high speed, the driving torque from the motor 4 is output to the rear shaft via the torque converter 31 with the lockup mechanism 31a operating. .

FIG. 10 shows a time chart of torque command values and the like that change in relation to the accelerator operation.
As shown in FIG. 10, when the accelerator operation is performed (when the accelerator changes from OFF to ON in FIG. 10A), the motor torque command value Tt is calculated based on the accelerator operation (FIG. 10B). )). At this time, the rotational speed of the motor 4 gradually increases ((c) in the figure), and the vehicle speed of the started vehicle also gradually increases ((d) in the figure). In this embodiment, the rotational speed of the motor 4 is temporarily high.

  When the vehicle starts, the clutch 34 is engaged (the electromagnetic clutch is turned on in FIG. 5F), and the lockup mechanism 31a of the torque converter 31 is released. (The lock-up mechanism 31a is OFF in FIG. 4 (e)), the four-wheel drive state is set, and the rear wheels 3L and 3R are driven by the torque amplified by the torque converter 31 (drive torque from the motor 4). It becomes like this.

Shortly after the start, the lockup mechanism 31a is activated (the lockup mechanism 31a is turned on in FIG. 5E), and the torque of the motor 4 is transmitted via the torque converter 31 (torque converter). Torque is not amplified at 31) and output to the rear shaft.
When a certain vehicle speed is reached, regardless of the accelerator operation, the motor torque command value Tt is set to 0 ((b) in the figure), and the rotational speed of the motor 4 decreases ((c) in the figure). . At this time, the clutch 34 is released (the electromagnetic clutch changes from ON to OFF in FIG. 5F), that is, a two-wheel drive state is set. Thereafter, when the vehicle speed decreases to some extent, the lock-up mechanism 31a is released (the lock-up mechanism 31a is turned off again in FIG. 4 (e)).

(effect)
The effect is as follows.
As described above, since the motor 4 and the rear shaft are connected via the torque converter 31, the function of the torque converter 31 as a fluid coupling allows the rotation of the motor 4 even if the drive shaft is locked. Therefore, the motor lock can be prevented with a simple configuration.
Further, as described above, the torque converter 31 amplifies the drive torque from the motor 4 and outputs it to the rear shaft, so that the drive torque from the motor 4 can be increased with a simple configuration. Thereby, the output of the rear shaft (the driving force of the rear wheels 3L, 3R) can be increased without increasing the input energy such as the engine torque and the external power source.

Further, for example, if the output of the rear shaft is not increased by limiting the output of the conventional rear shaft, the conventional rear shaft can be achieved without increasing the motor 4 speed or downsizing the motor 4. If it is about the output of, it will be possible to ensure. Further, since the reduction ratio is not changed, the operable vehicle speed range does not change.
Further, as described above, if the clutch 34 is constituted by a one-way clutch or a centrifugal clutch, the clutch 34 capable of engaging and disengaging the connection between the motor 4 and the rear shaft with sensitivity to the vehicle speed without performing complicated control. realizable.

  Further, as described above, the torque of the motor 4 amplified by the torque converter 31 is output to the rear shaft by the lock-up mechanism 31a of the torque converter 31, and when the vehicle speed increases to some extent, the torque converter 31 The torque of the motor 4 is output to the rear shaft without being amplified. Thereby, when a large torque is required as at the time of starting, a large torque can be output to the rear axle correspondingly, and when the vehicle speed increases, a transmission loss by the torque converter 31 is eliminated, The torque of the motor 4 can be output to the rear shaft.

  Further, when the vehicle travels backward, the lockup mechanism 31a is operated. Thereby, even if the torque converter 31 is provided, the torque of the motor 4 can be efficiently transmitted to the rear shaft. In addition, even when the vehicle travels backward, there may be a scene where the motor is locked. In this case, the lock-up mechanism 31a is released when the motor is likely to be locked. For example, generally, since the gear ratio of the reduction gears on the front wheels (main drive wheels) 1L, 1R side during reverse running is set high, even if the lockup mechanism 31a is released (in a two-wheel drive state) Even if it is accompanied by a start on a slope or escape from a hole, the vehicle can run backward without problems.

In addition, the said embodiment can also be implement | achieved by the following structures.
That is, in the embodiment, the configuration of the vehicle is described with a specific example. However, it is not limited to this. That is, the vehicle may be any vehicle as long as the driving wheels are driven by the driving torque from the motor.
In the description of the embodiment, the motor 4 realizes a motor capable of transmitting drive torque to the drive wheels, and the torque converter 31 is disposed in a drive torque transmission path from the motor to the drive wheels. Torque converter is realized.

It is a schematic structure figure showing an embodiment of the present invention. It is a figure which shows the structure of a generator. It is a figure which shows the structure of a driving force transmission part. It is a figure which shows the relationship between a vehicle speed and the operating state of a lockup mechanism. It is a block diagram which shows the detail of 4WD controller. It is a block diagram which shows the detail of a generator control part. It is a generator characteristic map for every rotation speed. It is a field current characteristic map for every number of rotations. It is a block diagram which shows the detail of a motor control part. It is a characteristic view which shows time charts, such as a torque command value which changes in relation with an accelerator operation.

Explanation of symbols

  1L, 1R front wheel, 2 engine, 3L, 3R rear wheel, 3a drive shaft, 4 motor, 4a drive shaft, 6 belt, 7 generator, 8 4WD controller, 8A target motor torque calculator, 8B generator supply power calculator 8C generator current command calculation unit, 8D generator control unit, 8E motor control unit, 8F TCS control unit, 8G clutch control unit, 8H load fixing determination unit, 8I motor control unit, 9 inverter, 10 junction box, 27FL, 27FR , 27RL, 27RR wheel speed sensor, 30 driving force transmission part, 31 torque converter, 31a lockup mechanism, 32 reduction gear part, 33 differential gear, 34 clutch

Claims (5)

A motor capable of transmitting drive torque to the drive wheels;
A fluid coupling disposed in a drive torque transmission path from the motor to the drive wheel;
A vehicle drive device comprising:   The vehicle drive device according to claim 1, wherein the fluid coupling is a torque converter.   The motor rotates forward and reverse the drive shaft that outputs the drive torque in response to the forward and backward movement of the vehicle, and the torque converter removes the motor from the motor when the drive shaft is rotating forward. A lockup mechanism that stops the transmission of the driving torque via the working fluid and transmits the driving torque in a directly connected state. The vehicle drive device according to claim 2, wherein the lockup mechanism is activated when the vehicle speed exceeds a predetermined vehicle speed.   The vehicle drive device according to claim 3, wherein the lockup mechanism is activated when the vehicle is traveling backward.   A drive torque transmission path from the motor to the driving wheel is provided with a one-way clutch or a centrifugal clutch, and the driving wheel is driven as a driven wheel driven by the motor, and the main driving wheel is driven by a main driving source. The one-way clutch or the centrifugal clutch is configured such that the one-way clutch or the centrifugal clutch is in a connected state in a four-wheel drive state, and the one-way clutch or the centrifugal clutch is in an open state in a two-wheel drive state. Item 5. The vehicle drive device according to any one of Items 1 to 4.

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