JP4134977B2 - Mode change control device for hybrid transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve fuel consumption by suppressing the change of driving force at the time of switching from a series hybrid mode to a parallel hybrid mode and reducing the power loss. <P>SOLUTION: In a series hybrid mode to t1, a motor/generator MG1 (revolution Nm1)is driven at fixed velocity by an engine ENG (revolution Ne) so as to generate electricity, and a motor/generator MG2 is driven to generate torque Tm2 with power from it thereby running a vehicle. The transition to a parallel hybrid mode is performed by breaking MG1 and ENG and fastening an engine clutch E/C. The fastening capacity Tc is raised so that it may be the fastening capacity required to keep E/C fastened, at t1 when the difference (Ne-Nc) of revolution before and after it becomes approximately zero with the progress of fastening of E/C. At or after t1, MG1 torque Tm1 is started to drop, and MG2 torque Tm2 is started to drop synchronously with it. The drop of MG1 torque Tm1 is controlled according to the rise of the fastening torque Tc of E/C. At t2 when the fastening capacity Tc of E/C becomes sufficient and MG 1 torque Tm1 becomes 0 Nm, the transition to the parallel hybrid mode is completed. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention interconnects the main power source, the two motor / generators, and the output to the drive system via a differential device that determines the rotational state of the other elements when the rotational state of the two elements is determined, The present invention relates to a mode switching control device for a hybrid transmission capable of performing a continuously variable transmission by a differential device.

  As the hybrid transmission, a series hybrid transmission that determines the output to the drive system by driving the other motor / generator with the electric power obtained by the electric power generated by one motor / generator driven by the main power source, A parallel hybrid transmission that determines the output to the drive system based on the power from the main power source and the power from the two motors / generators (there may be only power from one motor / generator). There is.

  On the other hand, a hybrid transmission which can selectively use both of these types is considered. In this case, the main power source and one motor / generator can be connected / disconnected by a clutch, and the main power source and the differential device can be connected. The corresponding rotating members of the main power source and one of the motor / generators are coupled by fastening the corresponding clutch, and the corresponding rotating members of the main power source and the differential device are associated with each other. A series hybrid mode that determines the output to the drive system by driving the other motor / generator with the electric power obtained by generating power from one motor / generator driven by the main power source by disengaging the clutch by releasing it, Disconnect the main power source and one motor / generator by releasing the corresponding clutch By connecting the power source and the corresponding rotating member of the differential device by fastening the corresponding clutch, the output to the drive system is determined by the power from the main power source and the power from at least one motor / generator And a parallel hybrid mode.

  The series hybrid mode is mainly used when the vehicle starts or when the required driving force is small, and the motor / generator and the main power source are coupled by engaging the corresponding clutch, The corresponding rotating members of the moving device are disconnected by releasing the corresponding clutch, and one motor / generator is driven at a constant rotational speed with torque from the main power source, and the generated power is used to drive the drive system. The vehicle is driven by driving the other motor / generator attached to the vehicle.

After the vehicle speed rises or when the required driving force becomes large, the required driving force cannot be realized in the series hybrid mode, so the transition to the parallel hybrid mode is performed.
At the time of transition to the parallel hybrid mode, the main power source and one of the motors / generators are disconnected by releasing the corresponding clutch, and the main power source and the corresponding rotating member of the differential device are connected by engaging the corresponding clutch. In this way, in the parallel hybrid mode, the vehicle can be driven with a large driving force by the power from the main power source and the power from both motors / generators or one of these motors / generators.

In the transition from the series hybrid mode to the parallel hybrid mode, the mode switching technology between the high-side shift mode and the low-side shift mode of the hybrid transmission described in Patent Document 1 is used. Immediately after engaging the clutch between the corresponding rotating members of the moving device, the clutch between the main power source and one of the motors / generators is released to cause a transition from the series hybrid mode to the parallel hybrid mode. It is common.
JP 2004-150627 A

However, the transition operation from the series hybrid mode to the parallel hybrid mode causes the following problems.
That is, in the series hybrid mode, as shown in FIG. 11, one motor / generator (MG1) generates a negative torque Tm1 that absorbs the torque Te of the main power source (engine), and the main power source (engine) At the instant when the difference between the rotation speed Ne (= MG1 rotation speed Nm1) and the output system clutch rotation speed Nc becomes zero, that is, at the instant t1 when the transition to the parallel hybrid mode is completed, one motor / generator MG1 and the other The motor / generator MG2 generates torque so as to cancel each other.
In this state, as shown in FIG. 11, when control is performed to reduce only the torque Tm1 of one motor / generator MG1 to 0 by releasing the clutch, the torque Te from the main power source (engine) is transmitted to the axle, and FIG. The vehicle driving force F increases rapidly as in the instant t1 to t2, and the vehicle is accelerated rapidly.

To solve this problem, even if the torque of the main power source (engine) and the torque of one motor / generator MG1 are coordinated and controlled, the main power source (engine) and the motor / generators MG1, MG2 Since the torque response differs greatly, it should be considered that perfect synchronization of torque control is hardly expected and the synchronization fails. In this case, there is a problem that the torque transmitted to the axle fluctuates and becomes uncomfortable.
If the motor / generator MG1 and MG2 continue to cancel each other's torque, the other motor / generator MG2 is driven using the power generated by one motor / generator MG1 to generate torque. Therefore, an extra power loss is generated by the amount of torque generated when both motors / generators MG1 and MG2 cancel each other's torque, and the fuel efficiency of the vehicle deteriorates.

Also, as shown in FIG. 12, when the torque Tm1 of one motor / generator MG1 is rapidly removed at the instant t1 when the difference between the engine speed Ne and the clutch input speed Nc of the output shaft system becomes zero, the main power source As is apparent from the change in the rotational speed Ne of the main power source (engine) between the instants t1 and t2 in FIG. 12, the clutch engagement capacity between the (engine) and the corresponding rotating member of the differential device is insufficient. The clutch will slide out again.
For this reason, there is a problem that transmission of torque Te of the main power source (engine) becomes unstable and disturbance of vehicle behavior occurs, and a problem that the wear amount of the clutch increases and the clutch life is reduced.

  In order to prevent the slipping of the clutch, if the time for holding the torque of one motor / generator MG1 is lengthened after absorbing the rotation of the clutch, the motor / generator MG1 absorbs the torque generated by the other motor / generator MG2. The electric power loss of the motor / generators MG1 and MG2 increases and the fuel consumption of the vehicle deteriorates.

  According to the present invention, when the canceling of the torques of the motors / generators is coordinated and canceled, the vehicle driving force increases rapidly (the vehicle suddenly accelerates without causing the above-mentioned problem related to the deterioration of fuel consumption due to electric loss). In view of the fact that the problem relating to) can be solved, it is an object of the present invention to propose a mode change control device for a hybrid transmission that embodies this idea.

For this purpose, a mode change control device for a hybrid transmission according to the present invention is constructed as described in claim 1.
First of all, the premise hybrid transmission is
When the rotational state of the two elements is determined, the outputs to the main power source, the two motors / generators, and the drive system are interconnected via a differential that determines the rotational state of the other elements.
The main power source and one motor / generator can be connected / disconnected by a clutch, and the corresponding rotary member of the main power source / differential device can be connected / disconnected by a clutch,
The main power source and one of the motors / generators are coupled by fastening the corresponding clutch, and the main power source and the corresponding rotating member of the differential device are disconnected by releasing the corresponding clutch, thereby being driven by the main power source. A series hybrid mode that determines the output to the drive system by driving the other motor / generator with the electric power generated by one motor / generator.
The main power source and one of the motor / generators are disconnected by releasing the corresponding clutch, and the main power source and the corresponding rotating member of the differential device are coupled by the engagement of the corresponding clutch. And a parallel hybrid mode that determines the output to the drive system by the power from at least one motor / generator.

The mode switching control device of the present invention is such a hybrid transmission,
When switching from the series hybrid mode to the parallel hybrid mode, the torque of the one motor / generator that generates torque so as to absorb the torque generated by the main power source during the series hybrid mode is changed to the main power source and the differential device. Control to 0 after completion of clutch engagement between corresponding rotating members of
In this configuration, the torque of the other motor / generator is reduced by the amount of fluctuation of the torque of the one motor / generator.

According to the mode change control device for a hybrid transmission according to the present invention, when the mode is switched from the series hybrid mode to the parallel hybrid mode, torque is generated so as to absorb the generated torque of the main power source during the series hybrid mode. The torque of one motor / generator is controlled to be 0 after completion of engagement of the clutch between the corresponding rotating members of the main power source and the differential device, and the other motor is controlled by the amount of torque fluctuation of the one motor / generator. / To reduce the generator torque,
To cancel the torque cancellation of both motors / generators in a coordinated manner, and to solve the problem related to rapid increase in vehicle driving force (sudden acceleration of the vehicle) without causing the above-mentioned problem related to deterioration of fuel consumption due to electric loss. Can do.

  In addition, since the two motors / generators have close torque responses, the torque control of these motors / generators is easy to synchronize. Since this synchronization is not reliable, the transmission torque to the axle fluctuates, which makes it uncomfortable. Can also be resolved.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 illustrates a power train of a vehicle equipped with a hybrid transmission to which the mode switching control device of the present invention can be applied.
In this power train, a first motor / generator MG1 is attached to the engine ENG, and a second motor / generator MG2 is attached to the engine side end of the speed change mechanism 10 constituting the main part of the hybrid transmission. A clutch 11 exists between MG1 and MG2, and the output of the speed change mechanism 10 is transmitted to the drive wheel 12 to generate the driving force of the vehicle.

FIG. 2 shows another power train of a vehicle equipped with a hybrid transmission to which the mode switching control device of the present invention can be applied.
In this power train, the first motor / generator MG1 is attached to the engine ENG, the second motor / generator MG2 is attached to the output side end of the transmission mechanism 10, and the first motor / generator MG1 and the transmission mechanism 10 A clutch 11 exists between the engine side end, and the output of the speed change mechanism 10 is transmitted to the drive wheel 12 to generate the driving force of the vehicle.

FIG. 3 shows still another power train of a vehicle equipped with a hybrid transmission to which the mode switching control device of the present invention can be applied.
In this power train, the transmission mechanism 10 is coupled to the engine ENG, the first motor / generator MG1 and the second motor / generator MG2 are attached to the transmission mechanism 10, and all the friction elements such as clutches are included in the transmission mechanism 10. And the output of the speed change mechanism 10 is transmitted to the drive wheels 12 to generate the driving force of the vehicle.

  The power train of a vehicle equipped with a hybrid transmission to which the mode switching control device of the present invention can be applied is not limited to that shown in FIGS. It includes all the powertrains of a vehicle with a hybrid transmission of the type that can be performed.

However, in this embodiment, the case where the power train is as shown in FIG. 3 will be described in detail below.
As shown in FIG. 4, the speed change mechanism 10 of FIG. 3 that forms the main part of the hybrid transmission is arranged in the middle of its axial direction (left-right direction in the figure), and is provided with a first simple planetary gear set G1. A second simple planetary gear set G2 is provided on the right side (rear end far from the engine ENG), and a third planetary gear set G3 is provided on the left side (front end near the engine ENG).

These planetary gear sets G1, G2, G3 are arranged coaxially with the engine ENG, respectively, and the first motor / generator MG1 and the second motor / generator are coaxially arranged between the planetary gear sets G1, G2, G3 and the engine ENG. Install MG2.
The planetary gear set G1, G2, G3 has three elements, which are sun gears S1, S2, S3, ring gears R1, R2, R3, and carriers C1, C2, C3 as rotating members. Thus, the two-degree-of-freedom differential device according to the present invention is configured.

The carrier C1 and the ring gear R2 are coupled to each other, and these combinations are connected to an input shaft 21 (indicated as an input In in the collinear diagram of FIG. 5) through which the engine ENG rotates, via an engine clutch E / C. Can be combined.
An output shaft 22 (shown as output Out in the collinear diagram of FIG. 5) is connected to the carrier C2 coaxially with the input shaft 21.

The sun gear S2 and the ring gear R3 are coupled to each other, and the ring gear R1 can be coupled to the first motor / generator MG1 by the motor / generator clutch MG1 / C and can be fixed by the high & low brake HL / B.
Further, the input shaft 21 and the first motor / generator MG1 can be coupled by a series clutch S / C.
The sun gears S1 and S2 are coupled to each other, and the combination is coupled to the second motor / generator MG2.
The carrier C3 can be fixed by the low brake L / B and can be coupled to the sun gear S3 by the high clutch H / C.

The hybrid transmission of FIG. 4 configured as described above is represented by a collinear diagram as shown in FIG. 5. The order of rotation speed of the rotating members in the first planetary gear set G1 is as follows: ring gear R1, carrier C1, and sun gear S1. The order of rotational speed of the rotating members in the second planetary gear set G2 is the ring gear R2, the carrier C2, and the sun gear S2.
An intermediate carrier C1 in the order of the rotational speed in the first planetary gear set G1 and a ring gear R2 in the first position in the order of the rotational speed in the second planetary gear set G2 are coupled to each other, and the second planetary gear set G2 The ring gear R3 and the sun gear S3 in the third planetary gear set G3 are coupled to the third gear sun gear S2 in the order of rotation speed and the third gear sun gear S1 in the order of rotation speed in the first planetary gear set G1, respectively. To do.

Further, a low brake L / B for fixing the carrier C3 of the third planetary gear set G3 is provided, and the carrier C3 and the sun gear S3 of the third planetary gear set G3 are coupled to each other, resulting in the sun gears S1, S2 A high clutch H / C that rotates the unit integrally is provided.
The ring gear R1 of the first planetary gear set G1 can be coupled to the first motor / generator MG1 by the motor / generator clutch MG1 / C and can be fixed by the high & low brake HL / B.

The input EN from the engine ENG can be coupled to the carrier C1 of the first planetary gear set G1 and the ring gear R2 of the second planetary gear set G2 via the engine clutch E / C. The engine ENG and the first motor / generator MG1 can be connected to each other by series clutch S / C.
An output Out to the wheel drive system is coupled to the carrier C2 of the second planetary gear set G2, and the second motor / generator is connected to the sun gear S1 of the first planetary gear set G1 and the sun gear S3 of the third planetary gear set G3. Join MG2.
The horizontal axis in FIG. 5 represents the distance ratio between the rotating members determined by the gear ratio of the planetary gear sets G1, G2, and G3, and the vertical axis represents the rotating speed of the rotating member (upward is the forward rotating speed and 0 Represents the reverse rotation speed).

  The hybrid transmission represented by the collinear diagram of FIG. 5 described above engages the engine clutch E / C so that the engine rotation is input to the carrier C1 and the ring gear R2, and releases the series clutch S / C. In the parallel hybrid mode in which the motor / generator MG1 is disconnected from the engine ENG and the motor / generator clutch MG1 / C is engaged and the motor / generator MG1 is coupled to the ring gear R1, the following operation is performed.

When the carrier C3 and the sun gear S3 of the planetary gear set G3 are coupled by the engagement of the high clutch H / C, all the rotating members of the planetary gear set G3 are rotated together, so that the collinear line in FIG. In the figure, the sun gear S2 coincides with the sun gears S1 and S3.
In this case, the lever G2 in FIG. 3 rides on the lever G1, and the gear train constituted by the planetary gear sets G1 and G2 provides a speed change state represented by a straight line of four elements and two degrees of freedom, and the rotational speed of the rotating member. In this order, the arrangement is motor / generator MG1, input In from engine ENG, output Out to wheel drive system, and motor / generator MG2.
Accordingly, the rotation of the output Out (carrier C2) becomes higher than that in the shift state of FIG. 5, and the shift in the high gear ratio range can be performed.

When the carrier C3 is fixed by engaging the low brake L / B, the sun gear S3 of the planetary gear set G3 rotates positively and the ring gear R3 rotates negatively as illustrated in the collinear diagram of FIG. A shift state in which the sun gear S1 rotates forward and the sun gear S2 rotates negatively is provided.
Accordingly, the rotation of the output Out (carrier C2) becomes a lower turning point than the rotation in the shift state when the high clutch H / C is engaged, and the shift in the low gear ratio range can be performed.

  In the parallel hybrid mode described above, the power from the engine ENG and the power from one or both of the motor / generators MG1 and MG2 are used both when shifting in the high gear ratio range and when shifting in the low gear ratio range. Is determined by the output Out to the drive system.

The hybrid transmission represented by the collinear diagram in FIG. 5 releases the engine clutch E / C, disconnects the engine ENG from the carrier C1 and the ring gear R2, and engages the series clutch S / C to connect the motor / generator MG1 to the engine. In the series hybrid mode, which is driven by ENG and the motor / generator clutch MG1 / C is released and the motor / generator MG1 is disconnected from the ring gear R1, it operates as follows.
In other words, the motor / generator MG1 is driven at a constant rotational speed (see FIG. 10) by the torque from the engine ENG to generate power, and the generated power is used, and if necessary, the battery power is used to output the output side. The vehicle is driven by driving the motor / generator MG2.
Therefore, in the series hybrid mode, the output Out to the drive system is determined only by the power from the motor / generator MG2.

At the time of transition from the series hybrid mode to the parallel hybrid mode, the engine clutch E / C is switched from the released state to the engaged state, and the series clutch S / C is switched from the engaged state to the released state. The control system shown in Fig. 6 is used.
This control system controls the engine ENG and motor / generators MG1 and MG2 for normal shift control in addition to the above-described state switching of the engine clutch E / C and series clutch S / C for mode switching. Shall.

The control system shown in FIG. 6 includes a hybrid controller 31. The hybrid controller 31 obtains a target engine torque and commands the engine controller 32. The engine controller 32 controls the opening degree of the throttle valve 33 and the fuel injection by the fuel injection device 34. The engine ENG is controlled by the amount control and the ignition timing control by the ignition device 35 so that the target engine torque is achieved.
The hybrid controller 31 further calculates the target torque of the motor / generators MG1 and MG2 and instructs the corresponding motor controllers 36 and 37 from the battery 40 via the corresponding inverters 38 and 39. By controlling the power supply amount, the motor / generators MG1 and MG2 are controlled to achieve their target torques.

The hybrid controller 31 obtains the above various target values based on the vehicle speed VSP, the accelerator opening APO, and the battery storage state SOC (carryable power) from the battery controller 41. The battery controller 41 determines the battery voltage, current consumption, Based on information such as the battery temperature, the state of the battery 40 is detected to obtain the chargeable / dischargeable power of the battery, and this is input to the hybrid controller 31 as the battery storage state SOC (capable power to be taken out).
Further, the hybrid controller 31 gives predetermined clutch engagement torque capacity commands to the clutches when the engine clutch E / C and the series clutch S / C are switched, and the clutch is controlled by current control of a solenoid valve (not shown). The corresponding required oil pressure is supplied to the clutch.

On the other hand, the engine clutch E / C and the series clutch S / C are provided with a clutch switch and a hydraulic pressure sensor for detecting the engaged state, and information from this is input to the hybrid controller 31 to switch the clutch described later. It shall be used for control.
The clutch switch outputs from 0 V to 5 V when the engagement hydraulic pressure in the corresponding clutch reaches the specified hydraulic pressure, and outputs from 5 V to 0 V when the hydraulic pressure falls below the specified hydraulic pressure. Based on the information from the clutch switch. In addition, the hybrid controller 31 can determine whether or not the clutch engagement hydraulic pressure has reached the set hydraulic pressure.
On the other hand, the hydraulic pressure sensor converts the clutch engagement hydraulic pressure into voltage and continuously detects the actual hydraulic pressure. Similarly, the hybrid controller 31 determines whether the clutch engagement hydraulic pressure has reached the set hydraulic pressure based on information from the hydraulic switch. It can be determined whether or not.
It is also possible to provide a temperature sensor as necessary, measure the temperature of the clutch hydraulic oil, and use it for clutch switching control.

The calculation process of the hybrid controller 31 will be described below with reference to FIGS.
FIG. 7 shows the main routine. In step S1, the vehicle target driving force requested by the driver is calculated from the vehicle speed VSP and the accelerator opening APO based on the planned target driving map.
Next, in step S2, the optimum driving mode (series hybrid mode, parallel hybrid mode) for the current driving state is determined from the target driving force, the vehicle speed VSP, and the battery storage state SOC (carryable power). The clutch engagement hydraulic pressure necessary to realize the determined mode is determined.

In step S3, the optimum driving mode determined as described above, the engagement state of the clutch, and the like are taken into consideration, and the optimum target engine speed for realizing the aforementioned target driving force is determined based on these.
In step S4, the optimum target engine torque is determined in consideration of the optimum traveling mode, the clutch engagement state, and the target engine speed.
In step S5, the required motor torques of the motors / generators MG1 and MG2 necessary for realizing the target driving force in step S1 are calculated in consideration of the target engine speed and the target engine torque.

FIG. 8 shows a subroutine related to switching control from the series hybrid mode to the parallel hybrid.
In step S11, it is checked whether or not it was the previous series hybrid mode, and if it is not the previous series hybrid mode, the parallel hybrid mode is being requested. Therefore, normal control in the parallel hybrid mode is performed in step S12.
When it is determined in step S11 that the previous series hybrid mode has been selected, it is determined in step S13 whether or not there has been a request for transition to the current parallel hybrid mode during traveling in the series hybrid mode.
If there is no transition request, the continuation of the series hybrid mode is requested. Therefore, in step S14, a counter for measuring the time described later is initialized, and then in step S15, normal control in the series hybrid mode is performed.

When it is determined in step S13 that there is a request for transition from the series hybrid mode to the parallel hybrid mode, it is determined in step S16 whether or not the torque Tm1 of the motor / generator MG1 is zero.
If the torque Tm1 of the motor / generator MG1 is 0, the above-mentioned problem does not occur even when the clutch is switched from the series hybrid mode to the parallel hybrid mode, so that the normal control in the parallel hybrid mode is performed in step S12. Make it.

However, when it is determined in step S16 that the torque Tm1 of the motor / generator MG1 is not 0, the motor / generator MG1 is set as follows until Tm1 = 0 in order to solve the above problem. Torque (Tm1) target value is calculated.
First, at step S17, it is determined whether or not the slip rotation amount of the engine clutch E / C, that is, the difference in rotation speed between the engine-side rotation speed Ne of the engine clutch E / C and the output-system rotation speed Nc is less than a set value. To check.
If the slip rotation amount of the engine clutch E / C is greater than or equal to the set value, the clutch rotation has not been absorbed and the mode switching conditions are not met, so in steps S18 and S19, a request for transition to the parallel hybrid mode is issued. The counter that measures the elapsed time from when the engine clutch E / C rotation absorption has ended (when the mode switching conditions are met) is initialized (the counter in step S14 is the same), and the normal in the series hybrid mode Continue control.

If it is determined in step S17 that the engine clutch E / C slip rotation amount (Ne−Nc) has become less than the set value (instant t1 in FIG. 10), the engine clutch E / C rotation absorption is over and the mode switching condition is Thus, in step S20, the engagement capacity torque command value for the engine clutch E / C is determined to be equal to or greater than the clutch engagement torque necessary for the engine clutch E / C to continue to be engaged in the parallel hybrid mode.
In step S21, whether or not the clutch switch that responds to the engagement hydraulic pressure of the engine clutch E / C is turned on, that is, the engagement hydraulic pressure of the engine clutch E / C reaches the specified hydraulic pressure and the output of the engine clutch switch is It is determined whether or not 0V → 5V (ON).

  When the clutch switch output determination is 0V → 5V (ON), in step S22, the time measured by the counter initialized in step S18 (step S14), that is, the rotation of the engine clutch E / C The clutch switch ON time from when the absorption is finished (momentary t1 in FIG. 10 when the mode switching conditions are met) until the output of the engine clutch switch changes from 0V to 5V (ON) is stored. An average process with past data relating to the ON time is performed, and the result is used as a learning value for the clutch switch ON time, and the control proceeds to step S23.

While it is determined in step S21 that the clutch switch output is not 0V → 5V (ON), the process in step S22 is skipped and the control proceeds to step S23.
In step S23, the engine clutch E / C engagement torque capacity gain is calculated by map search from the learned value of the clutch switch ON time, the elapsed time from the start of engagement of the engine clutch E / C, and the clutch hydraulic oil temperature. To do.
In step S24, a clutch engagement torque capacity estimation value Tc of the engine clutch E / C is obtained by multiplying the engagement torque capacity gain and the engagement request torque.

In the next step S25, a command value related to the torque Tm1 of the motor / generator MG1 is obtained by subtracting the engine torque Te from the clutch engagement torque capacity estimation value Tc of the engine clutch E / C. / Used to control generator MG1.
In step S26, from the command value related to the torque Tm2 of the motor / generator MG2 necessary for realizing the target driving force of the vehicle in the series hybrid mode, the command value related to the torque Tm1 of the motor / generator MG1 (the shaft of the motor / generator MG2) The current command value related to the torque Tm2 of the motor / generator MG2 is obtained by subtracting the value (converted to torque) and used for control of the motor / generator MG2.
The above processing is continued until the moment t2 in FIG. 10 when the torque Tm1 of the motor / generator MG1 becomes 0, and then step S16 advances the control to step S12, so that the transition from the series hybrid mode to the parallel hybrid mode is performed. The control is terminated and normal control in the parallel hybrid mode is performed.

The above control is as shown in FIG.
In the series hybrid mode up to the instant t1, the motor / generator MG1 (rotation speed Nm1) is driven at a constant speed by the engine ENG (rotation speed Ne).
In this state, the engine ENG generates torque Te in the positive direction, and the motor / generator MG1 works to absorb the torque and stabilize the rotation.
Therefore, since the motor / generator MG1 has a negative torque Tm1, it absorbs rotational energy and generates electric power.
The driving force of the vehicle is generated by the motor / generator MG2 driven by the electric power generated by the motor / generator MG1 or the electric power from the battery 40 (see FIG. 6).

When a mode transition request from the series hybrid mode to the parallel hybrid mode occurs, the engagement of the engine clutch E / C is advanced.
As the engine clutch E / C is engaged, the engine clutch E / C is engaged when the rotational synchronization instant t1 at which the forward / backward rotation difference (rotational slip amount) of the engine clutch E / C becomes less than the set value near 0 is reached. Increase the engagement capacity of the engine clutch E / C so that the engagement capacity is enough to continue. (Step S20)
In this state, the engine torque Te is still absorbed by the motor / generator MG1, and the vehicle is running with the torque Tm2 generated by the motor / generator MG2.

The motor / generator MG1 torque Tm1 starts to decrease and synchronizes after the rotation synchronization instant t1, when the engine clutch E / C engagement progresses and the rotational slip amount of the engine clutch E / C becomes less than the set value near 0. Then, the torque Tm2 of the motor / generator MG2 is started to decrease.
Since motor / generator MG1 generates torque in the negative direction and motor / generator MG2 generates torque in the positive direction, when torque Tm1 of motor / generator MG1 is decreased toward 0 Nm (step S25) The torque Tm2 of the motor / generator MG2 is also reduced toward 0 Nm (step S26).

On the other hand, the decrease in the torque Tm1 of the motor / generator MG1 is controlled in accordance with the rising (step S24) of the engagement torque Tc of the engine clutch E / C.
At this time, if the torque value generated in the series hybrid mode system exceeds the engagement capacity Tc of the engine clutch E / C, the engine clutch E / C slips, so the clutch of the engine clutch E / C is engaged. The torque Tm1 of the motor / generator MG1 is controlled so as to leave the torque capacity Tc.
The transition to the parallel hybrid mode is completed at the instant t2 when the engagement capacity Tc of the engine clutch E / C becomes sufficient and the torque Tm1 of the motor / generator MG1 becomes 0 Nm.

According to the hybrid transmission mode switching control according to the above-described embodiment,
When the mode is switched from the series hybrid mode to the parallel hybrid mode, the torque Tm1 of the motor / generator MG1 that generates torque so that the engine absorbs the generated torque Te during the series hybrid mode is completely engaged with the engine clutch E / C. In order to reduce the torque Tm2 of the motor / generator MG2 by the amount of torque fluctuation of the motor / generator MG1,
The cancellation of the torques Tm1 and Tm2 of both motors / generators MG1 and MG2 is canceled in a coordinated manner as during the instant t1 to t2 in FIG. The problem relating to the sudden increase in vehicle driving force (rapid acceleration of the vehicle) described with reference to FIGS. 11 and 12 can be solved.

  In addition, since the motors / generators MG1 and MG2 having close torque responses are coordinated, it is easy to synchronize the torque control of these motors / generators. Since this synchronization is not reliable, the torque transmitted to the axle fluctuates and it feels strange. This problem can be solved.

Further, in this embodiment, when the torque Tm1 of the motor / generator MG1 is controlled to decrease toward 0 Nm when switching from the series hybrid mode to the parallel hybrid mode, this torque Tm1 determines the engagement capacity Tc of the engine clutch E / C. Since it was made not to exceed (step S25),
As shown in FIG. 12, the engine clutch E is generated when the torque Tm1 of the motor / generator MG1 is rapidly removed at the instant t1 when the difference between the engine speed Ne and the clutch input speed Nc of the output shaft system becomes zero. The clutch starts to slip due to insufficient C / C engagement capacity, resulting in instability of engine torque Te transmission and disturbance of vehicle behavior, and a decrease in clutch life due to increased wear on the engine clutch. Can be avoided.

In this embodiment, furthermore, the engagement capacity Tc of the engine clutch E / C is estimated (step S24), and the torque reduction amount of the motor / generator MG1 is determined according to the clutch engagement capacity estimation value Tc.
The above-mentioned effects can be further ensured by more reliably avoiding the slippage caused by the insufficient engagement capacity of the engine clutch E / C, and the torque change time of the motor / generator MG1, MG2 can be shortened. Thus, fuel efficiency can be improved by shortening the series hybrid mode time with large power loss.

In the above embodiment, the engagement progress state of the engine clutch E / C is determined by turning on the clutch switch. However, as described above, a hydraulic sensor capable of directly detecting the clutch engagement hydraulic pressure instead of the clutch switch. When using
The control program for the mode switching control corresponding to FIG. 8 is as shown in FIG. 9, and the learning process in steps S21 to S24 in FIG. 8 is not necessary, and step S31 is set instead of these steps S21 to S24. Just do it.
Then, in step S31, the clutch is engaged based on the planned map from the engagement hydraulic pressure of the engine clutch E / C detected by the hydraulic sensor and, if necessary, the hydraulic oil temperature of the engine clutch E / C detected by the oil temperature sensor. The torque capacity estimation value Tc is obtained by searching.

  Even in this embodiment, only the method of obtaining the clutch engagement torque capacity estimation value Tc is different, and other than that, since it is the same as the above-described embodiment, it goes without saying that the various functions and effects described above can be produced similarly. Yes.

It is a basic diagram which shows the power train of the vehicle carrying the hybrid transmission which can apply the mode switching control apparatus by this invention. It is a basic diagram which shows the other example of the power train for vehicles carrying the hybrid transmission which can apply the mode switching control apparatus by this invention. It is a basic diagram which shows the further another example of the power train for vehicles carrying the hybrid transmission which can apply the mode switching control apparatus by this invention. FIG. 4 is a schematic diagram of the hybrid transmission in FIG. FIG. 6 is an alignment chart when the hybrid transmission is in a low gear ratio selection state. It is a block diagram according to function which shows the control system of the hybrid transmission. It is a flowchart which shows the main routine of the control program which the hybrid controller in the same control system performs. It is a flowchart which shows the subroutine regarding the mode switching control which the hybrid controller performs. It is a flowchart which shows the other example of the subroutine regarding the mode switching control. It is an operation | movement time chart of the mode switching control. It is an operation | movement time chart of the mode switching control at the time of applying the conventional method. It is an operation | movement time chart of the mode switching control at the time of applying the other conventional method.

Explanation of symbols

ENG engine (main power source)
10 Transmission mechanism
11 Clutch
12 driving wheels
MG1 First motor / generator (one motor / generator)
MG2 Second motor / generator (the other motor / generator)
21 Input shaft
22 Output shaft
Out2 2nd output shaft
G1 First planetary gear set (differential gear)
G2 2nd planetary gear set (differential gear)
G3 3rd planetary gear set (differential gear)
S1, S2, S3 Sun gear
R1, R2, R3 ring gear
C1, C2, C3 carrier
H / C high clutch
L / B Low brake
E / C engine clutch
S / C series clutch
MG1 / C motor / generator clutch
31 Hybrid controller
32 Engine controller
33 Throttle valve
34 Fuel injector
35 Ignition system
36 Motor controller
37 Motor controller
38 Inverter
39 Inverter
40 battery
41 Battery controller

Claims (3)

When the rotational state of the two elements is determined, the outputs to the main power source, the two motors / generators, and the drive system are interconnected via a differential that determines the rotational state of the other elements.
The main power source and one motor / generator can be connected / disconnected by a clutch, and the corresponding rotary member of the main power source / differential device can be connected / disconnected by a clutch,
The main power source and one of the motors / generators are coupled by fastening the corresponding clutch, and the main power source and the corresponding rotating member of the differential device are disconnected by releasing the corresponding clutch, thereby being driven by the main power source. A series hybrid mode that determines the output to the drive system by driving the other motor / generator with the electric power generated by one motor / generator.
The main power source and one of the motor / generators are disconnected by releasing the corresponding clutch, and the main power source and the corresponding rotating member of the differential device are coupled by the engagement of the corresponding clutch. And a hybrid transmission having a parallel hybrid mode that determines the output to the drive system by the power from at least one motor / generator,
When switching from the series hybrid mode to the parallel hybrid mode, the torque of the one motor / generator that generates torque so as to absorb the torque generated by the main power source during the series hybrid mode is changed to the main power source and the differential device. Control to 0 after completion of clutch engagement between corresponding rotating members of
A mode switching control device for a hybrid transmission, wherein the torque of the other motor / generator is reduced by the amount of fluctuation of the torque of the one motor / generator. In the hybrid transmission mode switching control device according to claim 1,
When the torque of one motor / generator is controlled to decrease toward zero when switching from the series hybrid mode to the parallel hybrid mode, the torque is applied to the clutch between the main power source and the corresponding rotating member of the differential device. A mode change control device for a hybrid transmission, characterized in that the capacity is not exceeded. In the hybrid transmission mode switching control device according to claim 1 or 2,
Estimate the engagement capacity of the clutch between the main power source and the corresponding rotating member of the differential,
A mode switching control device for a hybrid transmission, characterized in that the torque reduction amount of the one motor / generator is determined in accordance with the estimated clutch engagement capacity value.

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