JP4241664B2 - Hybrid vehicle mode transition control device - Google Patents

Description

  The present invention has a mode transition control of a hybrid vehicle having a driving force synthesis transmission having a differential device to which an engine and at least two motors are connected as a power source and to which the engine and the motor and a drive output member are connected. Relates to the device.

Conventionally, a four-element two-degree-of-freedom planetary gear mechanism in which four input / output elements are arranged on a collinear diagram is configured, and one of the two elements arranged on the inner side of the input / output elements is supplied from the engine. There is known a hybrid drive device in which an input is assigned to an output to the drive system on the other side, and a first motor generator and a second motor generator are connected to two elements arranged on both outer sides of the inner element, respectively. ing. A hybrid vehicle equipped with this drive device has, as travel modes, an electric vehicle travel mode using only a motor generator as a drive source and a hybrid vehicle travel mode using an engine and a motor generator as drive sources, depending on the drive source. Have. And in both driving modes, it has a continuously variable gear ratio mode for obtaining a continuously variable gear ratio and a fixed gear ratio mode for obtaining a fixed gear ratio according to the difference in gear ratio (see, for example, Patent Document 1).
JP 2003-32808 A

  In the conventional hybrid vehicle described above, the rotating element to which the first motor generator is connected is fixed to the case by the brake, and is supported by the transmission torque of the brake. At the time of the mode transition to the continuously variable transmission ratio mode to be supported, if the torque rise response of the first motor generator that outputs the support torque is delayed with respect to the release of the brake in which the support torque is reduced, the driving force is lost. There is a problem.

And even if it waits for the torque of the first motor generator to rise and then the brake is disconnected, the problem is that the generated torque of the first motor generator is limited in consideration of mechanically determined limits and heat generation. Therefore, when the torque generated by the first motor generator cannot exceed the brake torque, the transmission torque by the brake cannot be replaced with the first motor generator torque, and the brake slips and drives. Power loss cannot be reliably prevented.

  The present invention has been made paying attention to the above-mentioned problem, and reliably prevents the occurrence of driving force loss, including when the motor generated torque is limited during the mode transition from the fixed gear ratio mode to the continuously variable gear ratio mode. An object of the present invention is to provide a hybrid vehicle mode transition control device.

In order to achieve the above object, the present invention includes a driving force combining transmission having an engine and at least two motors as power sources, and having a differential device to which these engines and motors are connected to a drive output member. In hybrid vehicles,
The driving force combining transmission has at least one continuously variable transmission ratio mode for obtaining a continuously variable transmission ratio and at least one fixed transmission ratio mode for obtaining a fixed transmission ratio by controlling engagement / release of the frictional engagement element. And
Motor output possible torque calculating means for calculating a motor output possible torque connected to a rotating element fixed by a brake in the fixed gear ratio mode;
At the time of mode transition from the fixed gear ratio mode to the continuously variable gear ratio mode, in the fixed gear ratio mode, the transmission torque of the brake is applied to the rotating element fixed by the brake so as to be equal to or less than the motor output possible torque. Mode transition control that corrects the torque of the torque generating means other than the connected motor, waits for the torque of the motor connected to the rotating element fixed by the brake to rise, disconnects the brake, and transitions to the continuously variable transmission ratio mode Means,
Is provided.

  Therefore, in the hybrid vehicle mode transition control device of the present invention, the motor output possible torque calculation means calculates the output possible torque of the motor connected to the rotating element fixed by the brake in the fixed gear ratio mode. The In the mode transition from the fixed gear ratio mode to the continuously variable gear ratio mode, the mode transition control means is connected to the rotating element fixed by the brake so that the brake transmission torque is less than the motor output possible torque. The torque of the torque generating means other than the motor is corrected and the brake is disconnected after the torque of the motor connected to the rotating element fixed by the brake rises, and the mode is changed to the continuously variable transmission ratio mode. That is, the torque of the torque generating means other than the motor connected to the rotating element fixed by the brake is corrected so that the brake transmission torque is equal to or less than the motor output possible torque before the brake is disconnected. The motor can output a torque corresponding to the transmission torque of the brake even when the outputable torque of the motor is a limited value. As a result, at the time of mode transition from the fixed gear ratio mode to the continuously variable gear ratio mode, it is possible to reliably prevent the occurrence of driving force loss, including when the motor generated torque is limited.

  Hereinafter, the best mode for realizing a mode transition control device for a hybrid vehicle of the present invention will be described based on Example 1 shown in the drawings.

First, the configuration of the drive system of the hybrid vehicle will be described.
FIG. 1 is an overall system diagram showing a drive system of a hybrid vehicle to which the mode transition control device of Embodiment 1 is applied. As shown in FIG. 1, the drive system of the hybrid vehicle of the first embodiment includes an engine E, a first motor generator MG1 (motor), a second motor generator MG2 (motor), and an output shaft OUT (drive output member). And a driving force composite transmission having a differential device (first planetary gear PG1, second planetary gear PG2, third planetary gear PG3) to which these input / output elements E, MG1, MG2, and OUT are coupled. I have.

The friction engagement elements whose engagement and disengagement are controlled by the control hydraulic pressure from the hydraulic control device 5 to be described later according to the selected travel mode include a high clutch HC (first clutch) and an engine clutch EC (second clutch). ), A series clutch SC (third clutch) , a motor generator clutch MGC (fourth clutch) , a low brake LB (first brake), and a high / low brake HLB (second brake).

  The engine E is a gasoline engine or a diesel engine, and the opening degree of a throttle valve and the like are controlled based on a control command from an engine controller 1 described later.

  The first motor generator MG1 and the second motor generator MG2 are synchronous motor generators having a rotor in which permanent magnets are embedded and a stator around which a stator coil is wound. Based on this, the three-phase alternating current generated by the inverter 3 is independently controlled by applying it to each stator coil.

  The first planetary gear PG1, the second planetary gear PG2, and the third planetary gear PG3 serving as the differential devices are all single-pinion type planetary gears having two degrees of freedom. The first planetary gear PG1 includes a first sun gear S1, a first pinion carrier PC1 that supports the first pinion P1, and a first ring gear R1 that meshes with the first pinion P1. The second planetary gear PG2 includes a second sun gear S2, a second pinion carrier PC2 that supports the second pinion P2, and a second ring gear R2 that meshes with the second pinion P2. The third planetary gear PG3 includes a third sun gear S3, a third pinion carrier PC3 that supports the third pinion P3, and a third ring gear R3 that meshes with the third pinion P3.

  The first sun gear S1 and the second sun gear S2 are directly connected by a first rotating member M1, the first ring gear R1 and the third sun gear S3 are directly connected by a second rotating member M2, and the second pinion carrier PC2 The third ring gear R3 is directly connected by a third rotating member M3. Accordingly, the three planetary gears PG1, PG2, and PG3 include the first rotating member M1, the second rotating member M2, the third rotating member M3, the first pinion carrier PC1, the second ring gear R2, and the third pinion carrier PC3. It has 6 rotating elements.

The connection relationship between the power sources E, MG1, MG2, the output shaft OUT, and the respective engaging elements LB, HC, HLB, EC, SC, MGC for the six rotating elements of the differential device will be described.
A second motor generator MG2 is connected to the first rotating member M1 (S1, S2).
The second rotating member M2 (R1, R3) is not connected to any input / output element.
An engine E is connected to the third rotating member M3 (PC2, R3) via an engine clutch EC. Further, the first motor generator MG1 is connected via the engine clutch EC and the series clutch SC. That is, the engine E and the first motor generator MG1 are connected via the series clutch SC.
A second motor generator MG2 is connected to the first pinion carrier PC1 via a high clutch HC. Further, it is connected to the transmission case TC via a low brake LB.
A first motor generator MG1 is connected to the second ring gear R2 via a motor generator clutch MGC. Further, it is connected to the transmission case TC via a high / low brake HLB.
An output shaft OUT is connected to the third pinion carrier PC3. A driving force is transmitted from the output shaft OUT to the left and right driving wheels via a propeller shaft, a differential, and a drive shaft (not shown).

  Due to the above connection relationship, the first motor generator MG1 (R2), the engine E (PC2, R3), the output shaft OUT (PC3), and the second motor generator MG2 (S1, S2) on the alignment chart shown in FIG. A rigid lever model that is arranged in order and can easily express the dynamic operation of the planetary gear train (the first planetary gear PG1 lever (1), the second planetary gear PG2 lever (2), the third planetary gear PG3 lever) (3)) can be introduced. Here, the “collinear diagram” is a velocity diagram used in a simple and easy-to-understand method of drawing instead of the method of obtaining by equation when considering the gear ratio of the differential gear, Take the number of rotations (rotation speed) of the rotating elements, take each rotating element such as ring gear, carrier, sun gear, etc. on the horizontal axis, and set the interval between each rotating element to the collinear lever ratio (α , Β, δ).

  The high clutch HC is a multi-plate friction clutch that is fastened by hydraulic pressure, and is disposed at a position that coincides with the rotational speed axis of the second motor generator MG2 on the alignment chart of FIG. As shown in the nomograph, the “two-speed fixed transmission ratio mode”, the “high-side continuously variable transmission ratio mode”, and the “high gear fixed transmission ratio mode” that share the high-side transmission ratio by engagement are realized.

  The engine clutch EC is a multi-plate friction clutch that is engaged by hydraulic pressure, and is disposed at a position that coincides with the rotational speed axis of the engine E on the alignment chart of FIG. Is input to the third rotation member M3 (PC2, R3) which is an engine input rotation element.

  The series clutch SC is a multi-plate friction clutch that is fastened by hydraulic pressure, and is arranged at a position where the engine E and the first motor generator MG1 are connected on the alignment chart of FIG. 1 Motor generator MG1 is connected.

  The motor generator clutch MGC is a multi-plate friction clutch that is fastened by hydraulic pressure, and is disposed at a position connecting the first motor generator MG1 and the second ring gear R2 on the alignment chart of FIG. Release the engagement between MG1 and the second ring gear R2.

  The low brake LB is a multi-plate friction brake that is fastened by hydraulic pressure, and is disposed on the outer side of the rotational speed axis of the second motor generator MG2 on the alignment chart of FIG. As shown in the diagram, the "low gear fixed transmission ratio mode" and the "low side continuously variable transmission ratio mode" that share the low side transmission ratio by engagement are realized.

  The high / low brake HLB is a multi-plate friction brake fastened by hydraulic pressure, and is arranged at a position coincident with the rotational speed axis of the first motor generator MG1 on the alignment chart of FIG. As shown in the nomograph, the gear ratio is set to the "low gear fixed gear ratio mode" on the underdrive side by engaging with the low brake LB, and the gear ratio is set to "high gear fixed" on the overdrive side by engaging with the high clutch HC. “Speed change ratio mode”.

Next, the control system of the hybrid vehicle will be described.
As shown in FIG. 1, the hybrid vehicle control system in the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a hydraulic control device 5, an integrated controller 6, and an accelerator opening. a sensor 7, a vehicle speed sensor 8, an engine speed sensor 9, includes a first motor generator rotational speed sensor 10, a second motor generator rotational speed sensor 11, a third ring gear rotational speed sensor 12, the configuration Has been.

  The engine controller 1 responds to an engine operating point (Ne) according to a target engine torque command or the like from an integrated controller 6 that inputs an accelerator opening AP from an accelerator opening sensor 7 and an engine speed Ne from an engine speed sensor 9. , Te), for example, is output to a throttle valve actuator (not shown).

  The motor controller 2 responds to a target motor generator torque command from the integrated controller 6 that inputs motor generator rotation speeds N1 and N2 from both motor generator rotation speed sensors 10 and 11 by a resolver, and the motor of the first motor generator MG1. A command for independently controlling the operating point (N1, T1) and the motor operating point (N2, T2) of the second motor generator MG2 is output to the inverter 3. The motor controller 2 outputs information on the battery S.O.C representing the state of charge of the battery 4 to the integrated controller 6.

  The inverter 3 is connected to the respective stator coils of the first motor generator MG1 and the second motor generator MG2, and generates an independent three-phase alternating current according to a command from the motor controller 2. The inverter 3 is connected to a battery 4 that is discharged during power running and charged during regeneration.

  The hydraulic control device 5 includes a high clutch HC, an engine clutch EC, a series clutch SC, a motor generator clutch MGC, a low brake LB, and a high / low brake HLB based on a hydraulic command from the integrated controller 6. The fastening hydraulic pressure control and the opening hydraulic pressure control are performed. The engagement hydraulic pressure control and the release hydraulic pressure control include a half-clutch control based on a slip engagement control and a slip release control.

  The integrated controller 6 includes an accelerator opening AP from the accelerator opening sensor 7, a vehicle speed VSP from the vehicle speed sensor 8, an engine speed Ne from the engine speed sensor 9, and a first motor generator speed sensor 10. Information of the first motor generator rotational speed N1, the second motor generator rotational speed N2 from the second motor generator rotational speed sensor 11, the driving force combined transmission input rotational speed Ni from the third ring gear rotational speed sensor 12, etc. Is input and a predetermined calculation process is performed. Then, a control command is output to the engine controller 1, the motor controller 2, and the hydraulic control device 5 according to the calculation processing result.

  The integrated controller 6 and the engine controller 1 and the integrated controller 6 and the motor controller 2 are connected by bidirectional communication lines 14 and 15 for information exchange, respectively.

Next, the travel mode of the hybrid vehicle will be described.
The travel modes include a low gear fixed gear ratio mode (hereinafter referred to as “Low mode”), a low-side continuously variable gear ratio mode (hereinafter referred to as “Low-iVT mode”), and a second speed fixed gear ratio mode ( (Hereinafter referred to as “2nd mode”), a high-side continuously variable transmission ratio mode (hereinafter referred to as “High-iVT mode”), and a high gear fixed transmission ratio mode (hereinafter referred to as “High mode”). There are 5 driving modes.

  Regarding the five driving modes, an electric vehicle mode (hereinafter referred to as “EV mode”) in which only the motor generators MG1 and MG2 are driven without using the engine E, and an engine E and both motor generators MG1 and MG2 are used. And a hybrid vehicle mode (hereinafter referred to as “HEV mode”).

Therefore, as shown in FIG. 2 (five driving modes related to EV mode) and FIG. 3 (five driving modes related to HEV mode), the combination of “EV mode” and “HEV mode” is “10 driving modes”. Will be realized.
Here, Fig. 2 (a) is an alignment chart of "EV-Low mode", Fig. 2 (b) is an alignment chart of "EV-Low-iVT mode", and Fig. 2 (c) is "EV-2nd mode". 2D is an alignment chart of “EV-High-iVT mode”, and FIG. 2E is an alignment chart of “EV-High mode”. Fig. 3 (a) is a nomogram for "HEV-Low mode", Fig. 3 (b) is a nomogram for "HEV-Low-iVT mode", and Fig. 3 (c) is "HEV-2nd mode". FIG. 3D is a collinear diagram of “HEV-High-iVT mode”, and FIG. 3E is a collinear diagram of “HEV-High mode”.

  In the “Low mode”, as shown in the collinear diagram of FIGS. 2 (a) and 3 (a), the low brake LB is engaged, the high clutch HC is released, the high / low brake HLB is engaged, and the series clutch is engaged. This is a low gear fixed gear ratio mode obtained by opening the SC and engaging the motor generator clutch MGC.

  In the "Low-iVT mode", as shown in the collinear diagram of FIG. 2 (b) and FIG. 3 (b), the low brake LB is engaged, the high clutch HC is released, the high / low brake HLB is released, This is a low-side continuously variable transmission ratio mode obtained by opening the series clutch SC and engaging the motor generator clutch MGC.

  In the “2nd mode”, as shown in the collinear diagram of FIG. 2 (c) and FIG. 3 (c), the low brake LB is engaged, the high clutch HC is engaged, the high / low brake HLB is released, and the series clutch is engaged. This is a two-speed fixed gear ratio mode obtained by opening the SC and engaging the motor generator clutch MGC.

  In the “High-iVT mode”, the low brake LB is released, the high clutch HC is engaged, the high / low brake HLB is released, as shown in the collinear diagram of FIG. 2 (d) and FIG. 3 (d). This is a high-side continuously variable gear ratio mode obtained by opening the series clutch SC and engaging the motor generator clutch MGC.

  In the “High mode”, as shown in the collinear diagram of FIGS. 2 (e) and 3 (e), the low brake LB is released, the high clutch HC is engaged, the high / low brake HLB is engaged, and the series clutch is engaged. This is a high gear fixed gear ratio mode obtained by opening the SC and engaging the motor generator clutch MGC.

  Then, the mode transition control of the “10 travel modes” is performed by the integrated controller 6. That is, the integrated controller 6 is provided with the “10 travel modes” as shown in FIG. 4, for example, in a three-dimensional space by the required driving force Fdrv (determined by the accelerator opening AP), the vehicle speed VSP, and the battery SOC. The allocated travel mode map is set in advance. When the vehicle travels, the travel mode map is searched based on the detected values of the required driving force Fdrv, the vehicle speed VSP, and the battery SOC, and is determined by the required driving force Fdrv and the vehicle speed VSP. The optimum travel mode is selected according to the vehicle operating point and the battery charge amount. FIG. 4 is an example of a travel mode map that is represented in two dimensions by the required driving force Fdrv and the vehicle speed VSP by cutting out the three-dimensional travel mode map at a value with a sufficient capacity range of the battery S.O.C.

  Further, as a result of adopting the series clutch SC and the motor generator clutch MGC, in addition to the above “10 driving modes”, as shown in FIG. "S-Low mode") is added. This “S-Low mode” is obtained by engaging the low brake LB and the high / low brake HLB, releasing the engine clutch EC, the high clutch HC, and the motor generator clutch MGC, and engaging the series clutch SC.

  That is, the “10 travel mode” is a travel mode as a parallel type hybrid vehicle, but the “S-Low mode” which is a series low gear fixed gear ratio mode, as shown in FIG. 1 motor generator MG1 is separated from the collinear diagram, the first motor generator MG1 is driven by the engine E to generate electric power, the electric power generated by the first motor generator MG1 is received and charged, and the battery 4 is charged It can be said that this is a travel mode as a series hybrid vehicle in which the second motor generator MG2 is driven using electric power.

  When the mode transition is performed between the “EV mode” and the “HEV mode” by selecting the travel mode map, as shown in FIG. 5, the engine E is started and stopped, and the engine clutch EC is engaged. Control to release is executed. Further, when mode transition between the five modes of the “EV mode” and mode transition between the five modes of the “HEV mode” are performed, they are performed according to the ON / OFF operation table shown in FIG.

Next, the operation will be described.
[Mode transition control from “fixed gear ratio mode” to “continuously variable gear ratio mode”]
In the first embodiment, the mode transition pattern from the “fixed gear ratio mode” to the “continuously variable gear ratio mode” in the “HEV mode” or “EV mode” is as follows:
(1) From “Low mode” to “Low-iVT mode” (High-low brake HLB released)
(2) “2nd mode” to “High-iVT mode” (low brake LB release)
(3) “High mode” to “High-iVT mode” (low brake LB release)
And three mode transition patterns.

  In the integrated controller 6, during the mode transition according to the above pattern (1), in the “fixed gear ratio mode (Low mode)” before the mode transition, the transmission torque of the high / low brake HLB is transmitted to the first motor generator MG1. Torque of torque generating means (second motor generator MG2 and engine E) other than the first motor generator MG1 connected to the rotating element (second ring gear R2) fixed by the high / low brake HLB so that the torque can be output or less Correct.

  In addition, during the mode transition according to the patterns (2) and (3) above, in the “fixed gear ratio mode (2nd mode, High mode)” before the mode transition, the transmission torque of the low brake LB is the second motor generator MG2. Torque generating means (with the first motor generator MG1) other than the second motor generator MG2 connected to the rotating elements (the first sun gear S1 and the second sun gear S2) fixed by the low brake LB so as to be less than the output possible torque. Correct the torque of the engine E).

  When a mode transition request according to the above pattern (1) is issued, the high / low brake HLB is disconnected after waiting for the torque of the first motor generator MG1 connected to the rotating element fixed by the high / low brake HLB to rise. Transition to “speed gear ratio mode (Low-iVT mode)”.

  When a mode transition request according to the above patterns (2) and (3) is issued, the low brake LB waits for the torque of the second motor generator MG2 connected to the rotating element fixed by the low brake LB to rise. Is switched to “continuously variable transmission ratio mode (High-iVT mode)”.

  Hereinafter, of these mode transition patterns, the mode transition from the “HEV-Low mode” to the “HEV-Low-iVT mode” will be described as a representative example, and the mode transition control operation of the first embodiment will be described.

[Mode transition control processing]
FIG. 7 is a flowchart showing a flow of the mode transition control process at the time of the mode transition from the “HEV-Low mode” to the “HEV-Low-iVT mode” executed by the integrated controller 6 according to the first embodiment. Steps will be described (mode transition control means). This process is started when the “HEV-Low mode” is selected.

  In step S401, the vehicle state is detected. Accelerator opening APO, vehicle speed VSP, battery S.O.C, etc. are detected. Based on these parameters, the target driving force F of the vehicle is determined, and the process proceeds to step S402.

In step S402, following the detection of each parameter and determination of the target driving force F in step S401, the engine torque Te and the second motor generator torque T2 are determined in consideration of the vehicle state, the accelerator operation of the driver, fuel consumption, and the like. The process proceeds to step S403.
First, the engine torque Te is determined according to the target driving force F and the battery SOC. In addition, the control law of “HEV-Low mode” shown below,
T2 = k1F + k2Te (1)
Thus, the second motor generator torque T2 is determined.

In step S403, following the determination of the engine torque Te and the second motor generator torque T2 in step S402, the first motor generator connected to the second ring gear R2 fixed by the high / low brake HLB in the “HEV-Low mode”. The torque upper limit value that MG1 can output mechanically, and the torque upper limit value that the first motor generator MG1 connected to the second ring gear R2 fixed by the high / low brake HLB in the “HEV-Low mode” does not generate heat, The maximum torque that can be output in the range where no heat is generated by the select low is set to the first motor generator output possible torque T1max, and the process proceeds to step S404 (motor output possible torque calculating means).
Here, when determining the “torque upper limit value that does not generate heat”, the time required for mode transition can be predicted by experiment or simulation, and the time can be determined by using, for example, a table as shown in FIG. good.

In step S404, following the calculation of the first motor generator output possible torque T1max in step S403, the transmission torque TB of the high / low brake HLB is estimated from the following relational expression between the engine torque Te and the second motor generator torque T2. The process proceeds to step S405.
TB = k3F + k4Te + k5T2 (2)

  In step S405, following the estimation of the transmission torque TB of the high / low brake HLB in step S404, it is determined whether or not the high / low brake transmission torque TB is larger than the first motor generator output possible torque T1max. Since a driving force loss sometimes occurs, the process proceeds to step S406, and in the case of NO, a driving force loss does not occur at the time of mode transition, and the process proceeds to step S407.

In step S406, following the determination of TB> T1max in step S405, the engine torque Te and the second motor generator torque T2 are redistributed so that the high / low brake transmission torque TB is equal to or lower than the first motor generator output possible torque T1max. By doing so, the process proceeds to step S407.
Here, in order to set the high / low brake transmission torque TB to be equal to or less than the first motor / generator output possible torque T1max, it is understood from the equation (2) that the following relationship is satisfied.
T1max ≧ k3F + k4Te + k5T2 (3)
The engine torque Te and the second motor generator torque T2 satisfying both the expressions (3) and (1) are determined.

  In step S407, following the determination of Tb ≦ T1max in step S405 or the T2, Te torque correction control in step S406, it is determined whether or not there is a mode transition request to the “HEV-Low-iVT mode”. If YES, the process proceeds to step S408, and if NO, the process returns to step S401.

  In step S408, following the determination in step S407 that there is a mode transition request to the “HEV-Low-iVT mode”, a torque command is output to the first motor generator MG1, and the process proceeds to step S409.

  In step S409, it is determined whether the first motor generator torque T1 has been generated following the torque command to the first motor generator MG1 in step S408. If YES, the process proceeds to step S410. If NO, step S410 is performed. Repeat the determination of S409.

  In step S410, following the determination that the first motor generator torque T1 is generated in step S409, a release command for the high / low brake HLB is output, and the process proceeds to step S411.

  In step S411, following the release command of the high / low brake HLB in step S410, the process waits until the transmission torque TB by the high / low brake HLB becomes zero, and then shifts to the “HEV-Low-iVT mode”.

[Mode transition control action]
In describing the mode transition control operation from the “HEV-Low mode” to the “HEV-Low-iVT mode” in the first embodiment, the first torque without correcting the engine torque Te and the second motor generator torque T2 is used. The mode transition control operation when the high / low brake HLB is disconnected after waiting for the motor generator torque T1 to rise will be described.

In FIG. 9, the second ring gear R2 to which the first motor generator MG1 is connected is fixed to the transmission case TC by the high / low brake HLB, and the high / low brake HLB is supported by the transmission torque of the high / low brake HLB. When the second ring gear R2 is switched to the rotation state supported by the first motor / generator torque T1, the first time from the time k1 is the first to prevent the driving force from being lost due to the response delay of the first motor / generator torque T1. The start of the motor generator torque T1 is started, the rise is confirmed, and the high / low brake HLB is disconnected.
The sequence control, the first motor-generator torque T1 is no more torque transmitted by the high low brake HLB before reaching the target value, the lack of torque high low brake HLB is supported, to prevent the driving force comes out.
However, the first motor generator torque T1 has a mechanically determined limit and a limit in consideration of heat generation. Due to this limitation, as shown in FIG. 9, when the high / low brake transmission torque TB exceeds the first motor generator output possible torque T1max, the transmission torque by the high / low brake HLB between times k2 and k3 is changed to the first motor generator. The torque T1 cannot be sufficiently replaced, and the high / low brake HLB may slip, resulting in loss of driving force.

On the other hand, the mode transition control device of the first embodiment exhibits a mode transition control action as shown in FIG.
That is, before the time k1, it is the “HEV-Low mode”, and the engine torque Te and the second motor generator torque T2 are distributed according to the driving operation of the driver and the vehicle state.
From time k1 to time k3 is a mode transition phase, and control as shown in FIG. 7 is performed. After the time k3, it is the “HEV-Low-iVT mode”, and the engine torque Te, the first motor generator torque T1, and the second motor generator torque T2 are distributed according to the driving operation of the driver and the vehicle state.
Between time k1 and time k3, the relationship shown in the following equation is established by the control shown in the flowchart of FIG.
TB ≦ T1max… (5)
As a result, the high / low brake transmission torque TB becomes zero between the time k2 when the first motor generator torque T1 reaches the target torque and the time k3 when the control of the “HEV-Low-iVT mode” starts, and the high / low brake HLB Slip can be prevented. Thus, even when the high / low brake transmission torque TB exceeds the first motor generator output possible torque T1max, it is possible to reliably prevent the driving force from being lost.

Next, the effect will be described.
In the hybrid vehicle mode transition control apparatus of the first embodiment, the following effects can be obtained.

  (1) A driving force combining transmission having an engine E and at least two motor generators MG1 and MG2 as a power source and having a differential device to which the engine E and motor generators MG1 and MG2 are connected to a drive output member In the hybrid vehicle having the above, the driving force synthesizing transmission has at least one “continuously variable transmission ratio mode” for obtaining a continuously variable transmission ratio and at least one for obtaining a fixed transmission ratio by controlling engagement / release of the frictional engagement element. Motor output possible torque calculating means (step for calculating output possible torque of a motor generator connected to a rotating element fixed by a brake in the “fixed speed ratio mode”. S403) and at the time of the mode transition from the “fixed gear ratio mode” to the “continuously variable gear ratio mode”, the transmission of the brake is performed in the “fixed gear ratio mode”. The torque of the torque generating means other than the motor generator connected to the rotating element fixed by the brake is corrected so that the reached torque is less than the motor output possible torque (step S406), and the rotating element fixed by the brake And a mode transition control means (FIG. 7) which waits for the torque of the motor generator connected to the motor to rise and disconnects the brake to change the mode to the “continuously variable gear ratio mode”. At the time of the mode transition to the “continuously variable speed ratio mode”, it is possible to reliably prevent the occurrence of missing driving force including the case where the motor generated torque is limited.

  (2) The motor output possible torque calculating means (step S403) calculates a torque upper limit value that can be mechanically output by the motor generator connected to the rotating element fixed by the brake in the “fixed gear ratio mode”. Therefore, the motor generator torque does not exceed the mechanical torque range, and it is possible to reliably avoid the occurrence of driving force loss.

  (3) The motor output possible torque calculating means (step S403) calculates a torque upper limit value at which the motor generator connected to the rotating element fixed by the brake at the “fixed gear ratio mode” does not generate heat. Heat generation of the generator can be suppressed, and as a result, a decrease in motor generator output and an increase in cost due to a high performance motor generator cooler can be suppressed.

  (4) Since the motor output possible torque calculating means (step S403) predicts the time required for mode transition and calculates the torque upper limit value of the motor generator, it is possible to reliably suppress the heat generation of the motor generator when the brake is released. it can.

  (5) The differential device includes a single pinion type first planetary gear PG1, a second planetary gear PG2, and a third planetary gear PG3, and the driving force combining transmission includes the first sun gear S1 and the second sun gear. S2 is directly connected by the first rotating member M1, the first ring gear R1 and the third sun gear S3 are directly connected by the second rotating member M2, and the second pinion carrier PC2 and the third ring gear R3 are connected by the third rotating member M3. Directly connected, and having six rotating elements of the first rotating member M1, the second rotating member M2, the third rotating member M3, the first pinion carrier PC1, the second ring gear R2, and the third pinion carrier PC3, A second motor generator MG2 is connected to the first rotating member M1, an engine E is connected to the third rotating member M3 via an engine clutch EC, and a first motor generator is connected via an engine clutch EC and a series clutch SC. Is connected to the first pinion carrier PC1 via the high clutch HC and to the transmission case TC via the low brake LB, and to the second ring gear R2. Since the first motor generator MG1 is connected via the motor generator clutch MGC and the transmission case TC is connected via the high / low brake HLB, and the drive output shaft OUT is connected to the third pinion carrier PC3, “Low In the three mode transition patterns from “Mode” to “Low-iVT mode”, “2nd mode” to “High-iVT mode”, and “High mode” to “High-iVT mode”, (1) to (4) The described effects can be enjoyed.

  As mentioned above, although the mode transition control apparatus of the hybrid vehicle of this invention has been demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, Each claim of a Claim Design changes and additions are allowed without departing from the gist of the invention.

  For example, in the first embodiment, the mode transition from “HEV-Low mode” to “HEV-Low-iVT mode” is an example of mode transition from “continuously variable gear ratio mode” to “fixed gear ratio mode”. As described above, in the case of mode transition from “EV-Low mode” to “EV-Low-iVT mode”, in the case of mode transition from “HEV-2nd mode” to “HEV-High-iVT mode”, “EV In the case of mode transition from "-2nd mode" to "EV-High-iVT mode", in the case of mode transition from "HEV-High mode" to "HEV-High-iVT mode", from "EV-High mode" to " Of course, the present invention can also be applied to the mode transition to the “EV-High-iVT mode”.

  The mode transition control device of the first embodiment has been described as an example applied to a hybrid vehicle equipped with a driving force synthesis transmission having a differential gear constituted by three single pinion type planetary gears. As described in Japanese Patent Publication No. -32808, etc., the present invention can also be applied to a hybrid vehicle equipped with a driving force combining transmission having a differential gear constituted by Ravigneaux planetary gears. Further, the power source includes an engine and at least two motors, and includes a driving force combining transmission having a differential device to which the engine and the motor and a drive output member are connected, and at least one “ The present invention can also be applied to other hybrid vehicles having “continuously variable gear ratio mode” and “fixed gear ratio mode”.

1 is an overall system diagram illustrating a hybrid vehicle to which a mode transition control device according to a first embodiment is applied. FIG. 6 is a collinear diagram showing five driving modes in an electric vehicle mode in a hybrid vehicle equipped with the mode transition control device of the first embodiment. FIG. 5 is a collinear diagram showing five travel modes in a hybrid vehicle mode in a hybrid vehicle equipped with the mode transition control device of the first embodiment. It is a figure which shows an example of the driving mode map used for selection of driving mode in the hybrid vehicle carrying the mode transition control apparatus of Example 1. 4 is an operation table of an engine, an engine clutch, a motor generator, a low brake, a high clutch, a high-low brake, a series clutch, and a motor generator clutch in “10 driving modes” in the hybrid vehicle equipped with the mode transition control device of the first embodiment. . It is a collinear diagram which shows the relationship with each engagement element in the hybrid vehicle carrying the mode transition control apparatus of Example 1. FIG. 6 is a flowchart showing a flow of mode transition control processing at the time of mode transition from “HEV-Low mode” to “HEV-Low-iVT mode”, which is executed by the integrated controller according to the first embodiment. It is a figure which shows an example of the 1st motor generator output possible torque table with respect to the time which the mode transition of Example 1 requires. Mode transition requirement characteristics, brake transmission torque characteristics, 1st motor generator torque characteristics, and 1st time during mode transition from "HEV-Low mode" to "HEV-Low-iVT mode" without performing high-low brake transmission torque correction It is a time chart which shows 1 motor generator rotation speed characteristic and driving force characteristic, respectively. Mode transition requirement characteristics, brake transmission torque characteristics, first motor generator torque characteristics, first motor generator rotation speed characteristics during mode transition from "HEV-Low mode" to "HEV-Low-iVT mode" in the first embodiment -It is a time chart which shows a driving force characteristic, respectively.

Explanation of symbols

E engine
MG1 1st motor generator (motor)
MG2 Second motor generator (motor)
OUT Drive output shaft (drive output member)
PG1 1st planetary gear
PG2 2nd planetary gear
PG3 3rd planetary gear
HC high clutch (first clutch)
EC engine clutch (second clutch)
SC series clutch (3rd clutch)
MGC motor generator clutch (4th clutch)
LB Low brake (1st brake)
HLB High / Low brake (2nd brake)
DESCRIPTION OF SYMBOLS 1 Engine controller 2 Motor controller 3 Inverter 4 Battery 5 Hydraulic control apparatus 6 Integrated controller 7 Accelerator opening sensor 8 Vehicle speed sensor 9 Engine speed sensor 10 First motor generator speed sensor 11 Second motor generator speed sensor 12 Third ring gear Rotational speed sensor

Claims (4)

In a hybrid vehicle including a driving force combining transmission having an engine and at least two motors as a power source and having a differential device to which the engine and the motor and a drive output member are connected,
The driving force combining transmission has at least one continuously variable transmission ratio mode for obtaining a continuously variable transmission ratio and at least one fixed transmission ratio mode for obtaining a fixed transmission ratio by controlling engagement / release of the frictional engagement element. And
Motor output possible torque calculating means for calculating a motor output possible torque connected to a rotating element fixed by a brake in the fixed gear ratio mode;
At the time of mode transition from the fixed gear ratio mode to the continuously variable gear ratio mode, in the fixed gear ratio mode, the transmission torque of the brake is applied to the rotating element fixed by the brake so as to be equal to or less than the motor output possible torque. Mode transition control that corrects the torque of the torque generating means other than the connected motor, waits for the torque of the motor connected to the rotating element fixed by the brake to rise, disconnects the brake, and transitions to the continuously variable transmission ratio mode Means,
A mode transition control device for a hybrid vehicle, comprising: In the hybrid vehicle mode transition control device according to claim 1,
The motor output possible torque calculating means calculates a torque upper limit value that can be mechanically output by a motor connected to a rotating element fixed by a brake in the fixed gear ratio mode, and mode transition of the hybrid vehicle Control device. In the hybrid vehicle mode transition control device according to claim 1,
The motor output possible torque calculation means predicts the time required for mode transition, and the longer this prediction time , the smaller the torque upper limit value of the motor connected to the rotating element fixed by the brake in the fixed gear ratio mode. A hybrid vehicle mode transition control device. In the hybrid vehicle mode transition control device according to any one of claims 1 to 3 ,
The differential is composed of a single pinion type first planetary gear, a second planetary gear, and a third planetary gear,
In the driving force combining transmission, the first sun gear and the second sun gear are directly connected by the first rotating member, the first ring gear and the third sun gear are directly connected by the second rotating member, and the second pinion carrier and the third ring gear are connected. Are connected directly by a third rotating member, and have six rotating elements of the first rotating member, the second rotating member, the third rotating member, the first pinion carrier, the second ring gear, and the third pinion carrier,
A second motor generator is connected to the first rotating member, an engine is connected to the third rotating member via a second clutch, and a first motor generator is connected to the third rotating member via a second clutch and a third clutch. A second motor generator is connected to the first pinion carrier via a first clutch and a transmission case is connected via a first brake; a first motor is connected to the second ring gear via a fourth clutch. A mode transition control apparatus for a hybrid vehicle, characterized in that a generator is connected to a transmission case via a second brake, and the drive output member is connected to the third pinion carrier.

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