JP2002186109A - Auxiliary driving gear and front-and-rear wheel driven vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the safety of a vehicle when traveling on a wet road, a snowy road, a frozen road, or the like. SOLUTION: This auxiliary driving gear 1 is provided with a first generator 2 mounted on a front-and-rear wheels driven vehicle 100, the front wheels 104a, 104b of which are driven by an engine 101 and the rear wheels 105a, 105b of which are driven by a motor 4, and driven by the engine 101 to generate electric power; an inverter 3 that outputs the electric power generated by the first generator 2 to the motor 4 by power conversion; a motor control device 5 that controls the rotary driving force of the motor 4; and field control device 6 that controls the magnetic field of the first generator 2. In this driving gear 1, and motor control device 5 controls a voltage that is impressed on the motor 4 by using both controls of adjusting the power generating capacity of the first generator 2 and the output voltage of the inverter 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary drive device and a front and rear wheel drive vehicle equipped with the auxiliary drive device.

[0002]

2. Description of the Related Art Generally, in a front and rear wheel drive vehicle, one of a front wheel and a rear wheel is driven by an engine.
The other is configured to be driven by a motor. As such a front-rear wheel drive vehicle, for example,
There has been proposed in Japanese Patent Application No. -159502. In the front and rear wheel drive device proposed in this publication, an induction motor is mounted as a motor, and a battery is mounted as a power supply for the induction motor. Further, a direct current from the battery is converted into an alternating current and supplied to the induction motor. An inverter is provided.

[0003]

However, in the above conventional technique, a relatively high constant voltage of a battery is always applied to the inverter regardless of the voltage applied to the induction motor. The voltage jump generated when switching the elements is large, and an inverter having excellent withstand voltage performance is required to withstand this. Also, the induction motor cannot be driven at a high power factor,
The loss in the motor is also large.

Further, when the charged amount of the battery is reduced, it becomes impossible to supply sufficient electric power to the induction motor, and the vehicle stability is ensured when traveling on wet roads, snowy roads, frozen roads and the like. It is not preferable in doing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an auxiliary drive device which can ensure sufficient running stability by using a normal inverter and optimally driving a motor according to the running condition and running environment of a vehicle. And a front and rear wheel drive vehicle equipped with the auxiliary drive device.

[0006]

In order to achieve the above-mentioned object, an auxiliary driving device according to the present invention comprises a front wheel and a rear wheel.
One is driven by an engine, the other is mounted on a vehicle driven by a motor, a generator that is driven by the engine to generate power, an inverter that converts the generated power of the generator to power and outputs the power to the motor, A motor control unit that controls the rotational driving force of the motor, and a field control unit that controls the field of the generator, the motor control unit controls the power generation amount of the generator, The present invention is characterized in that the voltage applied to the motor is controlled using control for adjusting the output voltage.

According to the above configuration, the ratio of the driving force of the wheels driven by the engine to the driving force of the wheels driven by the motor can be changed as appropriate in accordance with the running state and the running environment. Accordingly, the vehicle can stably travel on wet roads, snowy roads, frozen roads, and the like.

More specifically, the motor control section has the following functions. (1) The control of adjusting the power generation of the generator by intermittent current flowing through the field coil of the generator and the control of adjusting the output voltage of the inverter based on the pulse amplitude modulation method are used together to apply the motor. Control the voltage. (2) The control for adjusting the amount of power generated by the generator by adjusting the voltage applied to the field coil of the generator and the control for adjusting the output voltage of the inverter based on the pulse width modulation method are used in combination. Control the applied voltage. (3) The control of adjusting the amount of power generated by the generator by intermittent current flowing through the field coil of the generator and the control of adjusting the output voltage of the inverter based on the pulse width modulation method are used together to apply the motor. Control the voltage. (4) The control for adjusting the amount of power generated by the generator by adjusting the voltage applied to the field coil of the generator and the control for adjusting the output voltage of the inverter based on the pulse amplitude modulation method are used together. Control the applied voltage.

The following configuration is also possible.
That is, the present invention provides a generator mounted on a vehicle driven by an engine and driven by a motor, one of a front wheel and a rear wheel, driven by the engine to generate power, and a power generated by the generator. An inverter that converts the electric power into electric power and outputs the electric power to the motor, a motor control unit that controls the rotational driving force of the motor, and a field control unit that controls the field of the generator. The voltage applied to the motor is controlled by using both control for adjusting the amount of power generated by the generator by intermittent current flowing in the field coil of the machine and control for adjusting the output voltage of the inverter based on a pulse amplitude modulation method. A first control unit for controlling the power generation amount of the generator by adjusting a voltage applied to a field coil of the generator, and a pulse width modulation method. Second control means for controlling the voltage applied to the motor in combination with control for adjusting the output voltage of the inverter, and control for adjusting the amount of power generated by the generator by interrupting the current flowing through the field coil of the generator. Controlling the voltage applied to the motor using a combination of controlling the output voltage of the inverter based on a pulse width modulation method.
And a selecting means for selecting one of the first control means, the second control means, and the third control means according to a running state or a running environment of the vehicle. It is characterized by:

Further, the present invention is a front-rear wheel drive vehicle equipped with any of the auxiliary drive devices having the above-mentioned configuration.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows the configuration of an auxiliary drive device 1 according to Embodiment 1 of the present invention, and a front and rear wheel drive vehicle 100 equipped with the same. In FIG. 1, an auxiliary drive device 1 includes a first generator 2 that is connected to a crankshaft 108 of an engine 101 and is driven to rotate, and an inverter that converts power generated by the first generator 2 into power and outputs the power to a motor 4. 3
A motor 4 that generates a rotational driving force by receiving the electric power of the inverter 3, a motor controller 5 that controls the rotational driving force of the motor 4, and a field controller 6 that controls the field of the first generator 2.
And a rotation sensor 40 for detecting the number of rotations of the motor 4. Further, the motor control unit 5 includes a motor torque determination unit 50, a motor current determination unit 51, a motor voltage determination unit 52, a field determination unit 53, and the like.

The motor 4 may be a synchronous servo motor, a switched reluctance motor, an induction motor, or the like.
A so-called AC servomotor is suitable, but the basic structure of the auxiliary drive device 1 is shown in FIG.
It is good as shown in.

Front and rear wheel drive vehicles (hereinafter abbreviated as vehicles)
Reference numeral 100 denotes an engine 101, which is an internal combustion engine, and converts the rotational driving force of the engine 101 into front wheels 104a, 104b.
, And front wheels 104a, 104b rotationally driven by rotational driving force from the transmission 102
To convert the rotational driving force of the motor 4 to the rear wheels 105a, 1
05b, and the rear wheel 1 rotationally driven by the rotational driving force from the driving force transmitting unit 103
05a, 105b and the like. Also, the front wheel 104
a, wheel speed sensor 106 for detecting the rotation speed of 104b
a, 106b, wheel speed sensors 106c, 106d for detecting rotation speeds of the rear wheels 105a, 105b, and the vehicle 10
A vehicle speed sensor 107 for detecting the traveling speed of 0 is provided.

The arrangement of the engine 101 and the motor 4 does not necessarily have to be as shown in FIG. 1, and depending on the layout, the rear wheels 105a, 105a,
105b is rotated and the motor 4 drives the front wheels 104a,
It is also possible to adopt a configuration in which the 4b is driven to rotate. Further, a configuration in which the motor 4 is arranged near the engine 101 can be adopted.

Hereinafter, the configurations of the first generator 2 and the field control unit 6 will be described with reference to the circuit diagram of FIG. First, the first
The configuration of the generator 2 will be described. The first generator 2 is 3
A phase alternating current generator 20 and a three-phase full-wave rectifier 21 are provided. The three-phase AC generator 20 includes a three-phase stator coil 22.
And the field coil 23 and the like. The stator coil 22 is wound around a stator (not shown), and the field coil 23 is connected to a crankshaft 108 of the engine 101.
And wound around a rotor (not shown) that is driven to rotate. The connection method of the stator coil 22 does not necessarily have to be a star connection as shown in FIG. 2, that is, a so-called star connection, and may be a triangular connection, that is, a so-called delta connection in some cases. The rotor is provided with slip rings 24a and 24b so that current can be supplied to the field coil 23 from the output of the three-phase full-wave rectifier 21 or the like. Since the rotor is rotatably supported inside the stator, the rotor magnetized by the field coil 23 rotates inside the stator coil 22. As a result, an electromotive force is generated in the stator coil 22 and power is generated.

The three-phase full-wave rectifier 21 is a three-phase AC generator 2
It is responsible for converting the AC power generated at 0 to DC power, and is configured by appropriately combining at least six diodes.

Next, the configuration of the field control section 6 will be described. The field control unit 6 includes a field current control transistor 63 for interrupting a current flowing through the field coil 23, and a first generator 2
Based on information from a first DC / DC converter 61 that transforms the generated voltage of the power supply into a predetermined voltage and a field determining unit 53 (see FIG. 1), specifically, information on the field method and amount, The transistor control circuit 60 for controlling the on / off operation of the magnetic current control transistor 63, the output voltage of the first DC / DC converter 61, and the like, and the voltage applied to the field coil 23 is supplied to the generation voltage side of the first generator 2. (A side) and a switch 62 for switching to any one of the output voltage side (B side) of the first DC / DC converter 61.
The switching of the switch 62 is optimally performed according to which of the first to fourth control means described later is selected.

Hereinafter, the operation of the auxiliary driving device 1 having the above configuration will be described. First, the operation of the motor control unit 5 will be described. Motor torque determination unit 5 inside motor control unit 5
0 is the traveling speed of the vehicle 100 obtained from the vehicle speed sensor 107, the speed of the front wheels 104a and 104b obtained from the wheel speed sensors 106a and 106b, and the wheel speed sensor 10
Based on the speeds and the like of the rear wheels 105a and 105b obtained from the motors 6c and 106d, the necessary torque to be generated by the motor 4 in order to maximize or optimize the driving force or the braking force of the rear wheels 105a and 105b (hereinafter, referred to as (Referred to as a target motor torque) and outputs it to the motor current determination unit 51.

For example, in order to maximize the driving force or the braking force, at the time of driving ((traveling speed of vehicle 100-speed of rear wheels 105a, 105b) / rear wheels 105a, 105b).
At the time of braking ((the running speed of the vehicle 100-the speed of the rear wheels 105a and 105b) / the running speed of the vehicle 100).
The vehicle 100 is controlled so that the absolute value of the so-called slip ratio, which is defined as
The speed of the rear wheels 105a and 105b may be controlled by the motor 4 according to the traveling speed of the vehicle. As a result, the rear wheels 105a,
Since the coefficient of friction between the road 105b and the road surface with which the rear wheels 105a and 105b are in contact is maximized, the driving force or the braking force is maximized. When the traveling speed of the vehicle 100 cannot be obtained, the motor 4 can be controlled based on an estimated value of the traveling speed obtained from the speed of the front wheels 104a, 104b and, in some cases, the rear wheels 105a, 105b. .

It should be noted that the target motor torque is not necessarily determined only as described above, but can be arbitrarily determined according to the driver's requirements and the like as long as the stability of the vehicle 100 is ensured.

The motor current determination unit 51 includes a rotation sensor 40 provided in the motor 4 and, in some cases, rear wheels 105a and 10a.
The current of the motor 4 required to generate the target motor torque (hereinafter, referred to as the target motor current) based on the rotation speed of the motor 4 obtained from the speed 5b and information such as the position obtained by integrating the rotation speed. ) Is determined, and the motor voltage determination unit 52 is determined.
Output to

The motor voltage determining unit 52 compares the current of the motor 4 obtained from a current sensor (not shown) provided in the motor 4 or the inverter 3 with a target motor current.
A necessary voltage to be applied to the motor 4 to flow the target motor current (hereinafter, referred to as a target motor voltage) is determined, and is output to the field determination unit 53 and the inverter 3.

When determining the target motor voltage,
It is desirable to consider compensation for current detection delay, compensation for sampling time, compensation for short-circuit prevention time of the inverter 3, and the like.

The field determining section 53 is provided with various information obtained from an engine control unit (not shown), the running speed of the vehicle 100, the running state and running environment of the vehicle 100 estimated from the speeds of the rear wheels 105a and 105b, and the like. , The first to fourth control means to be described later are selected, and the method and amount of the field are determined, and this is output to the field controller 6 and the inverter 3.

In general, in an AC servomotor, it is important to change the current flowing through it as quickly as possible. This is also true of the motor 4.

Therefore, in the auxiliary drive device 1 of the present embodiment, control for adjusting the method and amount of the field (hereinafter, referred to as field control) and control for adjusting the output voltage by switching of the inverter 3 (hereinafter, referred to as the field control). The output voltage control is also used to control the applied voltage of the motor 4. As a result, the voltage applied to the motor 4 can be controlled at high speed, so that the torque response performance of the motor 4 is improved and the vehicle 10
The motor 4 can be driven to rotate optimally according to the traveling state of 0, the traveling environment, and the like.

Hereinafter, the contents and operation of the first to fourth control means of the auxiliary drive device 1 using both the field control and the output voltage control will be described. First, the first control means of the auxiliary drive device 1 will be described. The first control means performs field control so that the generated voltage of the first generator 2 becomes an optimal voltage (hereinafter, referred to as a target generated voltage) according to the target motor voltage, and the output voltage of the inverter 3 is set to the target motor voltage. The output voltage is controlled so as to be equal to the voltage.

In the present embodiment, the value of the DC voltage such as the voltage generated by the first generator 2 means its magnitude, and the value of the AC voltage such as the target motor voltage means its half amplitude. are doing. However, the output voltage of the inverter 3, that is, the applied voltage of the motor 4, means its fundamental wave based on Fourier analysis or its one amplitude.

FIG. 3 shows a control flow of the first control means. At the same time that the vehicle 100 starts running, the field determining unit 53 estimates the running state, running environment, and the like of the vehicle 100 (Step 1), and selects the first control means based on the estimation (Step 2). ). Then, in the field control unit 6, the switch 62 is switched to the A side in FIG. 2 (step 3), and the voltage applied to the field coil 23 becomes the power generation voltage of the first generator 2.

Further, the motor torque determining section 50 calculates a target motor torque and outputs this to the motor current determining section 51 (step 4). The motor current determining unit 51 calculates a target motor current and outputs this to the motor voltage determining unit 52 (Step 5). The motor voltage determining unit 52 calculates a target motor voltage and outputs the calculated target motor voltage to the field determining unit 53 and the inverter 3 (Step 6).

In the field control section 6, a comparator (not shown) in the transistor control circuit 60 compares the generated voltage of the first generator 2 with the target generated voltage, thereby generating an ON / OFF operation signal. Is done. In response, the field current control transistor 63 sets the field coil 23
(Step 7). From the above,
The generated voltage of the first generator 2 becomes equal to the target generated voltage.

Next, in the inverter 3, elements such as transistors (not shown) in the inverter 3 are switched based on the pulse amplitude modulation method, and the output voltage of the inverter 3 is made equal to the target motor voltage. Control is performed (step 8).

Then, a three-phase AC voltage corresponding to the target motor voltage is applied to the motor 4, a target motor current flows through the motor 4, and a target motor torque is generated (step 9).

The target power generation voltage is determined so that the half amplitude of the fundamental wave when the output voltage of the inverter 3 is subjected to Fourier analysis becomes equal to the target motor voltage.

The magnitude of the torque generated by the motor 4 based on the first control means is converted by the driving force transmission unit 103 and transmitted to the rear wheels 105a and 105b. As a result, the driving force or the braking force of the rear wheels 105a and 105b becomes maximum or optimal, so that the wet road, the snow road,
Even when traveling on a road surface having a relatively low friction coefficient such as an icy road (hereinafter referred to as a low friction coefficient road), the stability of the vehicle 100 at the time of starting or stopping can be ensured. Also, front wheels 104a, 104b and rear wheels 105a, 105b
Of the front wheels 104a, 1
04b and the rear wheels 105a, 105b together with the engine 101
Front and rear wheel drive vehicles (hereinafter referred to as mechanical front and rear wheel drive vehicles) driven by the rotational driving force of the vehicle can travel on an uphill road where the vehicle cannot travel, and the stability of the vehicle 100 when starting or stopping Can be secured.

In the first control means, the voltage applied to the inverter 3 becomes the target power generation voltage. However, the target power generation voltage depends on the target motor torque, and when the target motor torque is low, the target power generation voltage becomes low. In this case, the voltage applied to the inverter 3 is suppressed to a low level. Therefore, compared to a case where a battery (not shown) is connected to the inverter 3 as a power source and a relatively high constant voltage is constantly applied, a voltage generated when switching elements such as transistors (not shown) in the inverter 3 is changed. Will be kept small. As a result, the withstand voltage performance of the inverter 3 is reduced, so that the size and cost of the inverter 3 can be reduced. Further, since the loss at the time of switching is reduced, the heat resistance is improved, and the reliability of the inverter 3 can be improved.

Further, since the applied voltage of the motor 4 is kept low and the power factor is improved, the loss of the motor 4 is reduced. Thus, the torque of the engine 101 that drives the first generator 2 to rotate is reduced, so that the fuel efficiency of the vehicle 100 can be improved.

As described above, the first control means is an effective control means capable of efficiently driving the inverter 3 and the motor 4, and the motor 4 is optimally driven to rotate in accordance with the running state of the vehicle 100, the running environment, and the like. Therefore, it is desirable that the present invention be widely applied in normal traveling.

FIG. 4C shows the first generator 2 based on the first control means when the vehicle 100 continues running at a constant acceleration from a stopped state (0 (sec) in the figure). FIG. 2 shows an example of a time chart of the generated voltage of FIG. A time chart of the traveling speed of the vehicle 100 at this time is shown in FIG.
FIG. 4B shows a time chart of the number of rotations of the generator 2 and the motor 4. Thus, the field control is performed so that the generated voltage of the first generator 2 becomes an optimum voltage corresponding to the target motor voltage, and the output voltage control is performed so that the applied voltage of the motor 4 becomes equal to the target motor voltage. You can see that it is. Therefore, as described above, the motor 4 is optimally rotated and driven according to the traveling state of the vehicle 100, the traveling environment, and the like.

FIG. 5 shows the relationship between the applied voltage of the inverter 3 based on the first control means and the applied voltage of elements such as transistors (not shown) in the inverter 3 when the target motor voltage is constant. , Referred to as an applied voltage of the element). As a result, the applied voltage of the inverter 3 is low, and the voltage rise is small. Therefore, the applied voltage of the element is suppressed low, and the maximum value (peak voltage in the figure) is lower than the withstand voltage of the element. You can see that. As a result, the size and cost of the inverter 3 can be reduced as described above. Also,
The reliability of the inverter 3 can be improved.

Next, the second control means of the auxiliary driving device 1 will be described. The second control means performs field control according to the rotation speed of the first generator 2 so that the amount of the field generated by the field coil 23 becomes a predetermined constant value, and the output voltage of the inverter 3 reaches a target value. The output voltage control is performed so as to be equal to the motor voltage.

FIG. 6 shows a control flow of the second control means. At the same time that the vehicle 100 starts running, the field determining unit 53 estimates the running state, the running environment, and the like of the vehicle 100 (Step 1), and selects the second control means based on the estimation (Step 2). ). And the first generator 2
The amount of the field generated by the field coil 23 (hereinafter, referred to as the field amount) is determined according to the rotation speed of the motor. Further, the field coil 2
The output voltage of the first DC / DC converter 61 is determined on the basis of the impedance of the third DC / DC converter. Then, in the field control unit 6, the switch 62 is switched to the B side in FIG. 2 (step 3 '), and the voltage applied to the field coil 23 is changed to the first DC voltage.
/ DC converter 61 output voltage.

Further, the motor torque determining section 50 calculates a target motor torque and outputs this to the motor current determining section 51 (step 4). The motor current determining unit 51 calculates a target motor current and outputs this to the motor voltage determining unit 52 (Step 5). The motor voltage determining unit 52 calculates a target motor voltage and outputs the calculated target motor voltage to the field determining unit 53 and the inverter 3 (Step 6).

In the field control section 6, an ON operation signal is generated by the transistor control circuit 60, and in response to this, the field current control transistor 63 is always turned ON.
Then, the transistor control circuit 60 controls the first DC / DC
The output voltage of the converter 61 is adjusted (Step 7 '). As described above, the field amount generated by the field coil 23 becomes a predetermined constant value.

Here, an example of a method of determining the field amount will be described. FIG. 7 shows an example of the power generation characteristics of the first generator 2. In FIG. 7, the horizontal axis represents the generated current, and the vertical axis represents the generated voltage and the generated output. The generated output indicates a value obtained by multiplying the generated current by the generated voltage. As described above, the power generation voltage when the power generation output is maximum is the first generator 2
, And the generated voltage tends to increase as the rotation speed increases.

Based on this power generation characteristic, the field determining unit 53
The rotation speed of the first generator 2 is estimated based on the rotation speed of the engine 101 obtained from an engine control unit (not shown), and the power generation voltage at which the power generation output becomes maximum at this rotation speed (hereinafter, referred to as output maximum voltage). ). Then, based on the impedance of the stator coil 22 and the like,
The field quantity for the generated voltage of the first generator 2 to become the maximum output voltage is determined. When calculating the field quantity, the first
Care must be taken that the generated voltage of the generator 2 is higher than the target motor voltage. Thus, the field quantity is determined.

It should be noted that the field quantity is not necessarily determined only as described above, but can be arbitrarily determined according to the power generation characteristics of the first generator 2.

Next, in the inverter 3, elements such as transistors (not shown) in the inverter 3 are switched based on the pulse width modulation method, and the output of the inverter 3 is output so as to be equal to the target motor voltage. Voltage control is performed (step 8 ').

As described above, since the three-phase AC voltage corresponding to the target motor voltage is applied to the motor 4, the target motor current flows through the motor 4, and the target motor torque is generated (step 9).

The magnitude of the torque generated by the motor 4 based on the second control means is converted by the driving force transmission unit 103 and transmitted to the rear wheels 105a and 105b. As a result, the driving force or the braking force of the rear wheels 105a and 105b is maximized or optimized. Therefore, even when the vehicle 100 travels on a road with a low friction coefficient, the vehicle 100 starts or stops.
Stability can be ensured. Also, the front wheel 104
a, 104b and the rear wheels 105a, 105b are relatively large in total driving force, so that it is possible to travel on an inclined uphill where a mechanical front-rear wheel drive vehicle cannot travel, and the vehicle 100 at the time of start or stop Stability can be ensured.

In the second control means, the power output of the first generator 2 can be maximized, for example, so that the required electric power is supplied to the motor 4 according to the required driving force of the rear wheels 105a, 105b. Can be supplied to Thus, the motor 4 can be rotationally driven optimally according to the traveling state of the vehicle 100, the traveling environment, and the like.

Even when the rotational driving force of the front wheels 104a and 104b suddenly increases due to the downshift of the transmission 102, the engine 101 associated with the downshift is used.
The power output of the first generator 2 increases due to the increase in the rotation speed of the engine 101, and the torque of the engine 101 consumed to rotationally drive the first generator 2 increases.
Thus, a sharp increase in the rotational driving force actually transmitted to the front wheels 104a and 104b via the second wheel 2 is avoided. Thereby, the front wheels 104a and 104b are driven to rotate without slipping, so that the stability of the vehicle 100 can be improved particularly when traveling uphill on a low friction coefficient road.

Further, even if the voltage generated by the first generator 2, that is, the voltage applied to the inverter 3, has a ripple,
Accordingly, since the appropriate switching is performed in the inverter 3 based on the pulse width modulation method, the output voltage of the inverter 3, that is, the applied voltage of the motor 4 can follow the target motor voltage at high speed. This allows
Since the torque response performance of the motor 4 is improved, the vehicle 100
The motor 4 can be optimally rotated in accordance with the traveling state, traveling environment, and the like of the vehicle.

As described above, the second control means is an effective control means capable of avoiding instability of the vehicle 100 due to downshifting of the transmission 102. Therefore, during traveling, the transmission 1 is controlled based on shift change information obtained from an engine control unit (not shown).
If it is determined that a downshift of 02 will be performed,
Before the downshift, the rotational driving force of the front wheels 104a and 104b is controlled by switching the control means of the auxiliary drive device 1 from, for example, the first control means to the second control means. , Front wheels 104a, 104b
However, the so-called slip does not occur, and the stability of the vehicle 100 particularly when traveling on a low friction coefficient road is secured.

FIG. 8 (c) shows the front wheel 104a based on the second control means, for example, when the transmission 102 is shifted down while the vehicle 100 is traveling on a low friction coefficient road at a constant speed. , 104b and rear wheels 105a, 105
6 shows an example of a time chart of the driving force b. A time chart of the rotation speeds of the engine 101 and the first generator 2 at this time is shown in FIG. 8A, and a time chart of the power output of the first generator 2 is shown in FIG. 8B. Accordingly, even if the transmission 102 is downshifted, the power output of the first generator 2 is increased by the increase in the rotation speed of the engine 101 associated with the downshift, and the first generator 2 is driven to rotate. It can be seen that since the consumed torque of the engine 101 is increased, a sharp increase in the driving force of the front wheels 104a and 104b driven by the engine 101 is suppressed. In addition, it can be seen that the driving power of the rear wheels 105a and 105b, which are rotationally driven by the motor 4 receiving the electric power, increases as the power generation output of the first generator 2 increases. As a result, the front wheels 104a, 10a
4b does not exceed the driving force at which the so-called slip occurs (the driving force at which the front wheels and the rear wheels slip) in the figure, thereby stabilizing the vehicle 100 when traveling on the low friction coefficient road as described above. Nature is secured.

Next, the third control means of the auxiliary driving device 1 will be described. The third control means performs field control according to the rotation speed of the first generator 2 so that the generated voltage of the first generator 2 becomes a predetermined constant value, and the output voltage of the inverter 3 becomes the target motor voltage. The output voltage control is performed so as to be equal to.

FIG. 9 shows a control flow of the third control means. At the same time that the vehicle 100 starts running, the field determination unit 53 estimates the running state, the running environment, and the like of the vehicle 100 (Step 1), and selects the third control unit based on the estimation (Step 2). ). And the first generator 2
An optimum power generation voltage (hereinafter referred to as a target power generation voltage) is determined according to the rotation speed of the motor, and a field method for determining that the power generation voltage of the first generator 2 becomes equal to the target power generation voltage is determined.
Then, in the field control unit 6, the switch 62 is set to A in FIG.
(Step 3), and the voltage applied to the field coil 23 becomes the power generation voltage of the first generator 2.

Further, the motor torque determining section 50 calculates a target motor torque and outputs this to the motor current determining section 51 (step 4). The motor current determining unit 51 calculates a target motor current and outputs this to the motor voltage determining unit 52 (Step 5). The motor voltage determining unit 52 calculates a target motor voltage and outputs the calculated target motor voltage to the field determining unit 53 and the inverter 3 (Step 6).

In the field control section 6, a comparator (not shown) in the transistor control circuit 60 compares the generated voltage of the first generator 2 with the target generated voltage, thereby generating an ON / OFF operation signal. Is done. In response, the field current control transistor 63 sets the field coil 23
(Step 7). From the above,
The generated voltage of the first generator 2 becomes equal to the target generated voltage.

Here, an example of a method for determining the target power generation voltage will be described. In the motor 4, the maximum torque generated (hereinafter, referred to as the maximum torque) and the applied voltage at this time (hereinafter, referred to as the maximum torque)
The maximum applied voltage is generally determined by the number of rotations. Therefore, if the target power generation voltage is set to a value slightly higher than the maximum applied voltage, for example, (maximum applied voltage × 2 / 1.73), the applied voltage of the inverter 3 is suppressed to the minimum necessary voltage, and as necessary. The maximum torque can be generated in the motor 4. As described above, the target power generation voltage is determined.

It should be noted that the target power generation voltage is not necessarily determined only as described above, but can be arbitrarily determined according to the power generation characteristics of the first generator 2, the electric characteristics of the motor 4, and the like.

Next, in the inverter 3, elements such as transistors (not shown) in the inverter 3 are switched based on the pulse width modulation method, and output voltage control is performed so that the output voltage of the inverter 3 becomes equal to the target motor voltage. Is performed (step 8 ').

As described above, since the three-phase AC voltage corresponding to the target motor voltage is applied to the motor 4, the target motor current flows through the motor 4, and the target motor torque is generated (step 9).

The magnitude of the torque generated by the motor 4 based on the third control means is converted by the driving force transmission unit 103 and transmitted to the rear wheels 105a and 105b. As a result, the driving force or the braking force of the rear wheels 105a and 105b is maximized or optimized. Therefore, even when the vehicle 100 travels on a road with a low friction coefficient, the vehicle 100 starts or stops.
Stability can be ensured. Also, the front wheel 104
a, 104b and the rear wheels 105a, 105b are relatively large in total driving force, so that it is possible to travel on an inclined uphill where a mechanical front-rear wheel drive vehicle cannot travel, and the vehicle 100 at the time of start or stop Stability can be ensured.

In the third control means, even when the target motor voltage changes due to the change in the target motor torque, the voltage generated by the first generator 2, that is, the voltage applied to the inverter 3, is maintained at the target voltage. As a result, the voltage applied to the inverter 3 can be suppressed to the minimum necessary voltage.
As compared with the case where a relatively high constant voltage is constantly applied, the voltage jump that occurs when an element such as a transistor (not shown) in the inverter 3 is switched can be suppressed low. As a result, the withstand voltage performance of the inverter 3 is relaxed, so that the size and cost of the inverter 3 can be reduced. Further, since the loss at the time of switching is reduced, the heat resistance is improved, and the reliability of the inverter 3 can be improved.

Further, since the applied voltage of the motor 4 is kept low and the power factor is improved, the loss of the motor 4 is reduced. Thus, the torque of the engine 101 that drives the first generator 2 to rotate is reduced, so that the fuel efficiency of the vehicle 100 can be improved.

Further, even if the voltage generated by the first generator 2, that is, the voltage applied to the inverter 3 has a ripple,
Accordingly, since the appropriate switching is performed in the inverter 3 based on the pulse width modulation method, the output voltage of the inverter 3, that is, the applied voltage of the motor 4 can follow the target motor voltage at high speed. This allows
Since the torque response performance of the motor 4 is improved, the vehicle 100
The motor 4 can be optimally rotated in accordance with the traveling state, traveling environment, and the like of the vehicle.

As described above, the third control means is an effective control method that allows the torque of the motor 4 to follow the target motor torque at high speed. Therefore, if it is determined that there is a possibility of downshifting the transmission 102 based on information on the driver's acceleration request obtained from an engine control unit (not shown) during traveling, By switching the control means of the auxiliary drive device 1 from, for example, the first control method to the third control method,
When the torque of the motor 4 is controlled at a high speed by the third control means, whereby the driving force of the rear wheels 105a, 105b rises rapidly, so that the driving force of the rear wheels 105a, 105b is required transiently. Of the vehicle 100 is secured. Further, in some cases, downshifting is avoided, so that so-called slippage of the front wheels 104a, 104b is avoided.

FIG. 10B shows an example of a time chart of the voltage applied to the inverter 3 and the output voltage of the motor 4 based on the third control means, for example, when the target motor torque reaches the maximum torque during traveling. ing. The time chart of the target motor torque at this time is shown in FIG.
Shown in From these, the optimal target generation voltage is determined,
Since the applied voltage of the inverter 3 is controlled based on this, it is understood that the applied voltage of the motor 4 is increased to the maximum applied voltage even if the target motor torque becomes the maximum torque. As a result, the motor 4 is optimally rotated and driven according to the traveling state, traveling environment, and the like of the vehicle 100 as described above.

As described above, in the auxiliary driving device 1 of the present embodiment, the field control for adjusting the method and amount of the field,
A first control means, a second control means, which uses output voltage control for adjusting the output voltage thereof by switching the inverter 3;
And the third control means can be realized, and by appropriately selecting and applying them according to the traveling state of the vehicle 100, the traveling environment, etc., the motor 4 can be optimally Can be driven, which allows wet roads,
The stability of the vehicle 100 when traveling on a snowy road, a frozen road, or the like can be ensured.

The auxiliary driving device 1 is used as a means for controlling the applied voltage of the motor 4 using both the field control and the output voltage control.
There is a fourth control means. In this method, the field control is performed so that the generated voltage of the first generator 2 becomes an optimum voltage according to the target motor voltage, and the output voltage is controlled so that the output voltage of the inverter 3 becomes equal to the target motor voltage. is there. Specifically, the field control is performed in steps 3 'and 7' in the second control means in FIG. 6, and the output voltage control is performed in step 8 in the first control means in FIG.

As described above, the first control means, the second control means, and the third control means are appropriately selected and applied in accordance with the traveling state of the vehicle 100, the traveling environment, and the like.
Although the stability of the vehicle 100 can be ensured, the stability can be further improved by adding and applying the fourth control means.

The auxiliary drive device 1 of the present embodiment is mounted on a front-wheel drive vehicle (not shown), which may constitute a front-rear-wheel drive vehicle 100. Therefore, as compared to the mechanical front-wheel drive vehicle, a chassis (not shown) constituting the vehicle 100 can be shared with the front wheel drive vehicle, the number of parts can be reduced, and the stability of the vehicle 100 at the time of starting and stopping can be improved. Thus, the cost and performance of the vehicle 100 can be reduced.

The auxiliary driving device 1 of the present embodiment is
A motor generator (not shown) functioning as a motor and a generator is provided in the vicinity of the engine 101, and may be mounted on the vehicle 100 that performs a so-called idle stop, which stops the engine 101 when the vehicle 100 stops. . Therefore, in the vehicle 100, in order to avoid so-called slippage of the front wheels 104a and 104b due to restart of the engine 101 from idling stop on a low friction coefficient road, the engine 101 is not started during low-speed running, and the motor 4 is not driven. The rear wheels 105a and 105b are rotationally driven by the rotational driving force, and the vehicle 100 can be started only by this driving force. As a result, the driving force of the rear wheels 105a and 105b is maximized or optimized, so that the stability of the vehicle 100 at the time of starting can be ensured even when traveling on a road with a low friction coefficient. Further, in the vehicle 100, since the idle stop is performed, the fuel efficiency is improved.

In the auxiliary drive device 1 according to the present embodiment, the motor 4 is rotationally driven by the power generated by the first generator 2.
As long as the vehicle is traveling, the required electric power can be supplied to the motor 4. Therefore, compared to a case where the motor 4 is driven to rotate by using a battery (not shown) as a power source, necessary electric power can be supplied to the motor 4 regardless of the charge amount of the battery. The motor 4 can be efficiently rotated and driven by
Since there is no need to mount a battery, there are advantages that the cost of the vehicle 100 can be reduced and maintainability can be improved.

Further, in the auxiliary driving device 1 of the present embodiment, as shown in FIG.
A converter 111 is connected, and a low-voltage battery 11
2 can be connected. As a result, when the vehicle 100 decelerates, the regenerative electric power generated by the motor 4 is supplied to the second DC /
The voltage is changed by the DC converter 111 and the low-voltage battery 11
2 can be charged. Thereby, the second generator 1
Since there is no need to rotationally drive the engine 10, the engine 10
1 is reduced, and the fuel efficiency of the vehicle 100 is improved. The voltage of the low-voltage battery 112 is about 12
V.

Further, the second generator 11 plays a role of charging the low-voltage battery 112 and supplying power to the low-voltage load 113.
Since the supply source of the charging power can be arbitrarily selected according to the power generation efficiency of each of the first and second generators 2, the low-voltage battery 112 can be charged efficiently, and the fuel efficiency of the vehicle 100 can be improved.

Further, in the auxiliary drive device 1 of the present embodiment, the first generator 2 and the field control section 6 can be integrated. As a result, power cables, signal cables, and the like (not shown) are shortened, so that copper loss generated by these can be reduced. Further, the size of the field control unit 6 is reduced,
Cost reduction can be achieved.

Further, in the front and rear wheel drive vehicle 100 equipped with the auxiliary drive device 1 of the present embodiment, the driving force transmitting section 103
Can be constituted by a clutch and a differential gear, not shown. This makes it possible to mechanically separate the rear wheels 105a and 105b from the motor 4 when the motor 4 does not need to be rotationally driven. as a result,
Since the rotor (not shown) constituting the motor 4 does not act as a load, the torque of the engine 101 is reduced,
The fuel efficiency of the vehicle 100 will be improved.
Since the high-speed rotation of the rotor is suppressed even when the motor 00 runs at a high speed, the size and cost of the motor 4 can be reduced. As the clutch, any of an electromagnetic clutch, a pneumatic clutch, a hydraulic clutch and the like may be used.

In the auxiliary drive device 1 according to the present embodiment, a so-called AC servomotor such as a synchronous servomotor, a switched reluctance motor, and an induction motor is used as the motor 4. Excellent in heat resistance, brush maintainability, etc. As a result, the size and cost of the motor 4 can be reduced.

Next, FIG. 11 shows a first embodiment of the present invention.
FIG. 2 is a sectional view of the generator 2. In FIG. 11, for example, a substantially cylindrical housing 8 formed by a die casting method is used.
5, the stator coil 22 is attached to the stator core 81.
Is fitted by, for example, shrink fitting, press fitting, or the like. At both ends of the housing 85,
The brackets 89a and 89b are fitted respectively,
It is fixed to the housing 85 by bolts not shown. A rotor 82 in which the field coil 23 is wound around two rotor cores 84 a and 84 b fitted at positions substantially opposite to the inner peripheral surface of the stator 80 of the shaft 83 is disposed inside the stator 80. ing. A pulley 90 is fitted to an end of the rotor 82 projecting from the bracket 89a, and is fixed by a bolt (not shown).

A plurality of in-wall cooling passages 86a and 86b are formed in the wall of the housing 85, and are formed by a plurality of side cooling passages 87a and 87b formed by the housing 85 and brackets 89a and 89b. And a predetermined cooling channel is formed. In-wall cooling channels 86a, 86
The cooling water 88 is filled in b and the side cooling channels 87a and 87b, and the cooling water 88 is circulated by a cooling water pump (not shown). The side cooling passages 87a,
The three-phase full-wave rectifier 21 and the like are arranged in the vicinity of 87b.

In the first generator 2 according to the present embodiment,
The relatively low-temperature cooling water 88 is supplied to the in-wall cooling passages 86a and 86.
b, by circulating through the side cooling passages 87a and 87b, the stator core 81 and the stator coil 2 which are main heat sources
Since the two- and three-phase full-wave rectifiers 21 and the like are effectively cooled,
The power generation output can be greatly increased. This allows
Since necessary electric power can be reliably supplied according to the output of the motor 4, the motor 4 can be optimally rotated.

The housing 85 and the bracket 89
a, 89b, etc., the inside is completely sealed, and the intrusion of water, dust, etc. is completely prevented.
There is no restriction on the location when mounting the device.

(Embodiment 2) FIG. 12 shows Embodiment 2 of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, a battery 7 such as a battery or a capacitor is connected to the inverter 3, and the power source of the motor 4 is switched by a switch (not shown) to either the first generator 2 or the battery 7 for convenience of control or the like. It is configured so that it can be switched between crabs.

With this configuration, the power source of the motor 4 is switched to the battery 7 when the power output of the first generator 2 is small, irrespective of the control means in the first embodiment. Necessary electric power can be reliably supplied according to the output of the motor 4, and the motor 4 can be optimally rotated.

Further, when the running speed of the vehicle 100 is low and the rotation speed of the engine 101 is low, for example, in a running state where the generated voltage of the first generator 2 is lower than the target motor voltage, in a running environment, the motor 4 Is switched to the battery 7, the output voltage of the inverter 3 is controlled based on the first control means, the second control means, or the third control means. Since the voltage is applied to the motor 4, stability of the vehicle 100 at the time of starting or stopping when traveling on a road with a low friction coefficient is ensured.

When the vehicle 100 decelerates, the motor 4
The battery 7 is charged with the regenerative electric power generated in the step (1), so that necessary electric power can be reliably supplied according to the output of the motor 4, and the motor 4 can be optimally rotated.

[0089]

As described above, according to the present invention,
Since the drive of the motor can be controlled to an optimum state according to the traveling state and traveling environment of the vehicle, the stability of the vehicle when traveling on wet roads, snowy roads, frozen roads and the like can be ensured.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an auxiliary drive device and a front-rear wheel drive vehicle according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a configuration of a first generator and a field control unit.

FIG. 3 is a diagram showing a control flow of a first control means.

FIG. 4 is a diagram showing a time chart based on a first control means.

FIG. 5 is a diagram showing a time chart of an applied voltage of an inverter based on a first control means and an applied voltage of an element such as a transistor in the inverter.

FIG. 6 is a diagram showing a control flow of a second control means.

FIG. 7 is a diagram illustrating an example of power generation characteristics of a first generator.

FIG. 8 is a diagram showing a time chart based on a second control means.

FIG. 9 is a diagram showing a control flow of a third control means.

FIG. 10 is a diagram showing a time chart based on a third control means.

FIG. 11 is a longitudinal sectional view of the first generator.

FIG. 12 is an overall configuration diagram of an auxiliary drive device and front and rear wheel drive vehicles according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Auxiliary drive device 2 1st generator 3 Inverter 4 Motor 5 Motor control unit 6 Field control unit 7 Battery 20 3-phase AC generator 21 3-phase full-wave rectifier 22 Stator coil 23 Field coil 24a, 24b Slip ring 40 Rotation sensor 50 Motor torque determiner 51 Motor current determiner 52 Motor voltage determiner 53 Field determiner 60 Transistor control circuit 61 First DC / DC converter 62 Switch 63 Field current control transistor 80 Stator 81 Stator core 82 Rotor 83 Shaft 84a, 84b Rotor Iron core 85 Housing 86a, 86b In-wall cooling passage 87a, 87b Side cooling passage 88 Cooling water 89a, 89b Bracket 90 Pulley 100 Front and rear wheel drive vehicle 101 Engine 102 Transmission 103 Driving force transmission unit 104a, 10 b wheel 105a, 105b rear wheel 106a, 106b, 106c 106d wheel speed sensor 107 vehicle speed sensor 108 crankshaft 110 second generator 111 first 2DC / DC converter 112 a low voltage battery 113 low voltage load.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Toshiyuki Inami, Hitachi, Ibaraki Pref. 5H115 PA01 PA08 PA12 PC06 PG04 PI13 PI24 PI29 PO02 PO06 PO17 PU01 PU09 PU10 PU24 PU25 PV02 PV07 PV09 PV23 QE04 QE10 QI04 QN23 RB08 RB22 SE04 SE05 SE08 TB03 TO12 TR05 TU05 5H576A15 BB06 CC02 CC06 DD02 DD04 DD05 DD09 EE11 EE18 EE19 GG02 GG04 HA02 HB01 JJ06 JJ08 JJ22 JJ25 LL01 LL22 LL24 LL38 LL41 PP01 5H590 AA02 AA15 AB01 CA07 CA23 CC01 CC18 CC24 CD01 CD03 FC04 FA07 EB12 FC04 EB07 EB12 EB04 GA02 HA02 HA11 HA27

Claims (7)

[Claims] 1. A generator, which is mounted on a vehicle driven by an engine and driven by a motor, one of a front wheel and a rear wheel, and driven by the engine to generate electric power. An inverter that converts power and outputs the electric power to the motor, a motor control unit that controls the rotational driving force of the motor, and a field control unit that controls the field of the generator, wherein the motor control unit includes the generator An auxiliary drive device for controlling the voltage applied to the motor by using both the control for adjusting the power generation amount and the control for adjusting the output voltage of the inverter. 2. A generator, one of a front wheel and a rear wheel, which is driven by an engine and the other is mounted on a vehicle driven by a motor, wherein the generator is driven by the engine to generate power, and the generated power of the generator is An inverter that converts power and outputs the electric power to the motor, a motor control unit that controls the rotational driving force of the motor, and a field control unit that controls the field of the generator, wherein the motor control unit includes the generator Control to adjust the amount of power generated by the generator by intermittent current flowing through the field coil;
An auxiliary drive device for controlling an applied voltage of the motor, together with a control for adjusting an output voltage of the inverter based on a pulse amplitude modulation method. 3. A generator mounted on a vehicle driven by an engine and driven by a motor, one of a front wheel and a rear wheel, wherein the generator is driven by the engine to generate power, and the power generated by the generator is An inverter that converts power and outputs the electric power to the motor, a motor control unit that controls the rotational driving force of the motor, and a field control unit that controls the field of the generator, wherein the motor control unit includes the generator Control to adjust the amount of power generated by the generator by adjusting the voltage applied to the field coil, and control to adjust the output voltage of the inverter based on a pulse width modulation method, An auxiliary drive device characterized by controlling. 4. A generator mounted on a vehicle driven by an engine and driven by a motor, one of a front wheel and a rear wheel, wherein the generator is driven by the engine to generate power, and the power generated by the generator is An inverter that converts power and outputs the electric power to the motor, a motor control unit that controls the rotational driving force of the motor, and a field control unit that controls the field of the generator, wherein the motor control unit includes the generator Control to adjust the amount of power generated by the generator by intermittent current flowing through the field coil;
An auxiliary driving device for controlling the applied voltage of the motor, together with control for adjusting the output voltage of the inverter based on a pulse width modulation method. 5. A generator, one of a front wheel and a rear wheel, which is driven by an engine and the other is mounted on a vehicle driven by a motor, wherein the generator is driven by the engine to generate power, and the generated power of the generator is An inverter that converts power and outputs the electric power to the motor, a motor control unit that controls the rotational driving force of the motor, and a field control unit that controls the field of the generator, wherein the motor control unit includes the generator The control applied to adjust the amount of power generated by the generator by adjusting the voltage applied to the field coil and the control used to adjust the output voltage of the inverter based on a pulse amplitude modulation method are used together to reduce the applied voltage of the motor. An auxiliary drive device characterized by controlling. 6. A generator mounted on a vehicle driven by an engine and driven by a motor, one of a front wheel and a rear wheel, wherein the generator is driven by the engine to generate power, and the generated power of the generator is An inverter that converts power and outputs the electric power to the motor; a motor control unit that controls the rotational driving force of the motor; and a field control unit that controls the field of the generator. The control of the applied voltage of the motor is controlled by using both the control for adjusting the power generation amount of the generator by the intermittent current flowing through the field coil and the control for adjusting the output voltage of the inverter based on a pulse amplitude modulation method. A first control unit, a control for adjusting a power generation amount of the generator by adjusting a voltage applied to a field coil of the generator, and the input based on a pulse width modulation method. Second control means for controlling the voltage applied to the motor in combination with control for adjusting the output voltage of the motor, and adjusting the power generation amount of the generator by intermittent current flowing through a field coil of the generator. Third control means for controlling the voltage applied to the motor by using both control and control for adjusting the output voltage of the inverter based on a pulse width modulation method; and An auxiliary drive device comprising: a first control unit, a selection unit that selects one of the second control unit and the third control unit. 7. A front-rear wheel drive vehicle equipped with the auxiliary drive device according to claim 1.