JP3992002B2 - Shift control device for hybrid transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shift control device for a hybrid transmission capable of avoiding a problem wherein state switching of a low brake becomes difficult when switching shift modes. <P>SOLUTION: A first enlargement EIVT-LB mode area is set by enlarging the EIVT-LB mode area to the EIVT mode area at a low vehicle speed and large driving force area shown in (a) where the EIVT mode area between the EV-LB mode area and the EIVT-LB mode area is narrow and the state switching of the low brake is difficult. When operation moving an action point as shown by line A is performed, at arrival at point A1, an engine clutch is slip-bonded for preventing engine stop while the fastening state of the low brake is maintained for switching from the EV-LB mode shown by a solid line on a common figure (b) to the first enlargement EIVT-LB mode area shown by a broken line on the same common figure. At arrival at point A2 from the first enlargement EIVT-LB mode area, the engine clutch in the slip-bonding state is completely fastened while the fastening state of the low brake is maintained for switching from the first enlargement EIVT-LB mode shown by the broken line on the common figure to the EIVT-LB mode shown by the solid line on the common figure. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to a hybrid transmission useful for a hybrid vehicle equipped with a main power source such as an engine and a motor / generator, and in particular, a continuously variable transmission operation is performed by a differential device between the main power source and the motor / generator. The present invention relates to a shift control device useful for a hybrid transmission that can be operated, particularly when driving at a low vehicle speed and a large driving force.

As this kind of hybrid transmission, for example, as described in Patent Document 1, a two-degree-of-freedom differential device constituted by a planetary gear set is provided, and an engine that is a main power source is provided to each rotary member of the differential device. The main power source which is a driving force generation source by connecting the two motors / generators to each other, enabling the continuously variable transmission by combining the two motors / generators, and further allowing the predetermined rotating member to be appropriately fixed by the low brake. Also known are those that can amplify torque from a motor / generator.
JP 2000-094973 A

  In such a hybrid transmission, both the motor / generator with the low brake engaged and the EV mode in which the output to the drive system is determined only by the power from the motor / generator without using the power from the main power source. The EV-LB mode that determines the output to the drive system based only on the power from the engine, the EIVT mode that determines the output to the drive system based on the power from the main power source and the power from both motors / generators, and low brake In this state, it is conceivable to set four operation modes including the EIVT-LB mode in which the output from the main power source and the power from both motors / generators are used to determine the output to the drive system.

By the way, each operation mode is not useful in all areas, but there are areas that each is good at, depending on the vehicle speed VSP, the required driving force F, and the state of charge SOC (power that can be taken out) of the motor / generator battery. And useful areas are determined.
For example, when the EV mode region is shown on the two-dimensional coordinates of the vehicle speed VSP and the required driving force F, it is as shown in FIG. 9, and the EV-LB mode region is shown on the two-dimensional coordinates of the vehicle speed VSP and the required driving force F. FIG. 10 shows the EIVT mode region as shown in FIG. 11 on the two-dimensional coordinates of the vehicle speed VSP and the required driving force F, and the EIVT-LB mode region shows the two-dimensional vehicle speed VSP and the required driving force F. When shown on the coordinates, it is as shown in FIG.

  The above four shift operation mode regions are collectively shown in FIG. 13 on the same two-dimensional coordinates of the vehicle speed VSP and the required driving force F, and the vehicle speed VSP is less than VSP1 and the required driving force F is F1 or more. In the low vehicle speed and large driving force region, there is a narrow EIVT mode region between the EV-LB mode region and the EIVT-LB mode region, and any shift operation mode in the large driving force region than the narrow EIVT mode region. In some cases, a blank area EM that does not belong to the case may occur.

The narrow EIVT mode region between the EV-LB mode region and the EIVT-LB mode region, and the low vehicle speed and large driving force region including the blank region EM are enlarged and conceptually shown as shown in FIG. When the battery storage state SOC (power that can be taken out) is large, as shown by the solid line in FIG. The LB mode area becomes wider, and the EIVT mode area and the blank area EM become narrow accordingly.
Conversely, when the battery charge state SOC (power that can be taken out) is small, as shown by the broken line in the figure, the area where the EV-LB mode in which electric driving is performed only by the motor / generator becomes narrower, and accordingly, the EIVT The mode area and the blank area EM are widened.

However, in any case, in the above-mentioned low vehicle speed and large driving force region, an operation was performed in which the operating point ● is moved as illustrated by lines A and B on FIG. 15 similar to the solid line of FIG. At this time, the shift mode is switched at the point ◯ on the region boundary line.
In line A, when the A1 point is reached from the EV-LB mode area, the low brake is released and the main power source clutch is engaged to switch from the EV-LB mode to the EIVT mode. When the A2 point is reached, the low brake is engaged again to switch from the EIVT mode to the EIVT-LB mode.

By the way, in the low vehicle speed and large driving force region, the EIVT mode region is narrow, and the low brake state switching necessary for the above-described sequential switching between the EV-LB mode, the EIVT mode, and the EIVT-LB mode can be performed. Have difficulty.
As described above with reference to FIG. 14, this tendency is large in the battery storage state SOC (power that can be taken out), the EV-LB mode area in which electric driving is performed only by the motor / generator is widened, and the EIVT mode area is narrowed accordingly. It becomes noticeable.

  Next, referring to line B in FIG. 15, when the point B1 is reached from the EV-LB mode region, the low brake is released and the clutch of the main power source is engaged for switching from the EV-LB mode to the EIVT mode. When the B2 point is reached from the EIVT mode area, no shift mode is selected because it enters the blank area EM. When the B3 point is reached from the blank area EM, the low brake is applied to select the EIVT-LB mode. Re-engage and re-engage the main power source clutch.

In this case, because the EIVT mode area and the blank area EM are narrow, the blank area EM is in addition to the same problem as described above that it is difficult to switch the state of the low brake required for the sequential switching between the shift modes. The following problems arise from passing through
That is, in the low vehicle speed and large driving force region where the blank region EM exists, it is necessary to quickly start the vehicle with a large driving force from the vehicle speed VSP = 0, or to quickly complete the approach to the highway. Is an important area including cases,
This low vehicle speed and large driving force area may become a blank area that does not belong to any speed change operation mode. Until the vehicle speed VSP increases to the EIVT-LB mode lower limit vehicle speed VSP1, This makes it impossible to accelerate the vehicle and prevents a quick start and entry to the highway.

  To solve this problem, the lower limit vehicle speed VSP1 of the EIVT-LB mode region can be reduced to reduce the blank region EM. However, in this EIVT-LB mode, the vehicle speed VSP and the main power source (engine) speed are reduced. And the main power source (engine) has a lower limit (for example, 800 rpm) and an upper limit (for example, 8000 rpm), and the main power source (engine) has a lower limit (for example, 800 rpm). ), The lower limit vehicle speed VSP1 in the EIVT-LB mode region cannot be reduced.

  The present invention eliminates the need to switch the state of the low brake when entering the EIVT mode area from the EV-LB mode area or the EIVT-LB mode area, so that at least the EIVT mode area or this area and the blank area EM Therefore, it is an object of the present invention to propose a shift control device for a hybrid transmission that can avoid the former problem that it is difficult to switch the state of the low brake when the shift mode is switched.

For this purpose, the shift control device for a hybrid transmission according to the present invention is constructed as described in claim 1.
First of all, the premised hybrid transmission has a plurality of rotating members as rotating members arranged on the nomograph, and when the rotating state of two of these rotating members is determined, the rotating state of the other members A two-degree-of-freedom differential device, wherein one of the two rotating members located on the inner side of the collinear diagram is input from the main power source via a clutch, and the other is a drive system. The two motor / generators are respectively coupled to the two rotating members positioned on the outer side of the nomogram, and the rotator to which the outputs are coupled is shared on the nomogram. The low brake is connected to the rotating member between the rotating member combined with the output side motor / generator close to the output on the diagram ,
EIVT-LB mode that determines the power to the output using the power from the main power source and the power from both motors / generators via the clutch in a state where the low brake is engaged,
EV-LB mode that determines the power to the output using only the power from the motors / generators with the low brake engaged,
It has at least an EIVT mode in which the power to the output is determined using the power from the main power source and the power from both motors / generators via the clutch with the low brake released.

Based on such a hybrid transmission, in the present invention,
Low vehicle speed with a narrow EIVT mode area, which requires sequential switching between the EV-LB mode, EIVT mode, and EIVT-LB mode, making it difficult to switch the state of the low brake required for the mode switching. When the driving state enters the EIVT mode area during driving with a large driving force, the EIVT-LB mode area is expanded to the EIVT mode area to form the first extended EIVT-LB mode area. In the extended EIVT-LB mode region, the clutch is slip-coupled so that the rotational speed of the main power source is maintained at the operable rotational speed even at the low vehicle speed.

In the above-described shift control apparatus for a hybrid transmission according to the present invention,
Sequential switching between EV-LB mode, EIVT mode, and EIVT-LB mode is required, and the low-speed, When the driving state enters the EIVT mode area during driving force operation, the EIVT-LB mode area is extended to this EIVT mode area to form the first extended EIVT-LB mode area. This first extended EIVT-LB mode In order to make the clutch slip-coupled so that the rotational speed of the main power source is maintained at the operable rotational speed even at the low vehicle speed in the region,
As described above, when the driving state enters the EIVT mode area during driving at low vehicle speed and large driving force, the EIVT mode area is the first extension where the low brake should be switched from engagement to release for the EIVT mode area. By adopting the EIVT-LB mode area, this low brake will be held in the engaged state, and this difficulty can be avoided even if low brake state switching control is difficult due to the narrow EIVT mode area. .

By the way, in the first extended EIVT-LB mode region, since it is basically the EIVT-LB mode, the vehicle speed and the main power source rotational speed are in a proportional relationship, and the main power source rotational speed is related to the current vehicle speed. Is uniquely determined.
Since the vehicle speed is currently low as described above, the rotational speed of the main power source may be lower than the operable speed, but in the present invention, the rotational speed of the main power source is also in such a case. Since the clutch is slip-coupled so that the engine speed is maintained at an operable speed, the change from the EIVT mode region to the first EIVT-LB mode region may cause the main power source to become inoperable. Absent.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 illustrates a hybrid transmission to which a shift control apparatus according to an embodiment of the present invention can be applied, and this is configured as a transaxle for a front-wheel drive vehicle (FF vehicle) in this embodiment.
In the figure, reference numeral 1 denotes a transmission case, in which a Ravigneaux type planetary gear set 2 is incorporated on the left side in the axial direction (left and right direction in the figure) of the transmission case 1, and a composite current two-layer motor 3 is incorporated on the right side in the figure.
On the further left side of the Ravigneaux type planetary gear set 2, an engine (main power source) ENG is arranged coaxially, which is outside the transmission case 1.

The Ravigneaux type planetary gear set 2 and the composite current two-layer motor 3 are coaxially arranged on the main axis of the hybrid transmission and mounted in the transmission case 1. The transmission case 1 is further offset from the main axis. The counter shaft 6 and the differential gear device 7 arranged in parallel are also incorporated,
The left and right drive wheels 8 are drivingly coupled to the differential gear device 7.

The Ravigneaux type planetary gear set 2 is a combination of a single pinion planetary gear set 4 and a double pinion planetary gear set 5 that share the long pinion P2 and the ring gear R2. Place on the side close to ENG.
Single pinion planetary gear set 4 has a structure in which long pinion P2 is engaged with sun gear S2 and ring gear R2, respectively.
The double pinion planetary gear set 5 has, in addition to the shared pinion P2, a sun gear S1 and a ring gear R1, and a large-diameter short pinion P1 meshed with the sun gear S1, and a structure in which the short pinion P1 is meshed with the shared pinion P2. .
All the pinions P1 and P2 of the planetary gear sets 4 and 5 are rotatably supported by a common carrier C.

The Ravigneaux-type planetary gear set 2 having the above-described configuration mainly includes five rotating members of the sun gear S1, the sun gear S2, the ring gear R1, the ring gear R2, and the carrier C. Of these five members, two members are included. When the rotational speed is determined, a two-degree-of-freedom differential device in which the rotational speed of the other members is determined is configured.
The rotational speed order of the five rotating members is the order of the sun gear S1, the ring gear R2, the carrier C, the ring gear R1, and the sun gear S2, as shown in the alignment chart of FIGS.

The composite current two-layer motor 3 includes an inner rotor 3ri and an annular outer rotor 3ro that surrounds the inner rotor 3ri so as to be coaxially rotatable in the transmission case 1 and between the inner rotor 3ri and the outer rotor 3ro. An annular stator 3s arranged coaxially in the annular space is fixed to the transmission case 1.
The annular coil 3s and the inner rotor 3ri constitute a first motor / generator MG1 as an inner motor / generator, and the annular coil 3s and the outer rotor 3ro constitute a second motor / generator MG2 as an outer motor / generator. Configure.
Here, each of the motor / generators MG1 and MG2 is rotated in an individual direction according to the supply current and at an individual speed (including stop) according to the supply current when the composite current is supplied as a load on the motor side. It functions as a motor that outputs, and functions as a generator that generates electric power according to rotation by an external force when the generator side applies a composite current as a load.

  The five rotating members of the Ravigneaux planetary gear set 2 are shown in the order of rotational speed, that is, in the collinear charts of FIGS. 2 to 5, but the sun gear S1, the ring gear R2, the carrier C, the ring gear R1, and the sun gear S2. The first motor / generator MG1, the input from the engine ENG as the main power source, the output to the wheel drive system (Out), the low brake L / B, and the second motor / generator MG2 are coupled in order.

This coupling will be described in detail below with reference to FIGS. 2 to 5. In order to use the ring gear R2 as an input element for inputting the engine rotation as described above, the engine ENG crankshaft is connected to the ring gear R2 via the engine clutch 9. Join.
The sun gear S1 is coupled to the first motor / generator MG1 (inner rotor 4ri) via a hollow shaft 11 extending rearward opposite to the engine ENG, and the motor / generator MG1 and the hollow shaft 11 are loosely fitted. The sun gear S2 is coupled to the second motor / generator MG2 (outer rotor 4ro) via the central shaft 12.
A low brake L / B is provided between the ring gear R1 and the transmission case 1, and the ring gear R1 can be fixed by the low brake L / B.

In order to use the carrier C as an output element that outputs rotation to the wheel drive system as described above, the output gear 14 is coupled to the carrier C via a hollow connecting member (output shaft) 13, and this is connected to the Ravigneaux type planetary gear set. 2 and a composite current two-layer motor 3 and is rotatably supported in the transmission case 1.
The output gear 14 meshes with the counter gear 15 on the counter shaft 6, and the transmission output rotation from the output gear 14 passes through the counter gear 15 and then reaches the differential gear device 7 through the counter shaft 6. It is assumed that the differential gear device distributes the left and right drive wheels 8 to form a wheel drive system.

The hybrid transmission configured as described above can be represented by collinear charts as shown in FIGS. 2 to 5, and the horizontal axis of these collinear charts represents the distance between the rotating members determined by the gear ratio of the planetary gear sets 4 and 5. , That is, the ratio of the distance between the sun gear S1 and the ring gear R2 when the distance between the ring gear R2 and the carrier C is 1, and the distance between the carrier C and the sun gear S2 is denoted by β. The distance between R1 is indicated by γ.
The vertical axis of the nomograph shows the rotational speed of each rotating member, that is, the engine speed Ne to the ring gear R2, the speed N1 of the sun gear S1 (motor / generator MG1), and the output (Out) speed No from the carrier C. , And the rotation speed N2 of the sun gear S2 (motor / generator MG2) and the rotation speed of the ring gear R1 that can be fixed by the low brake L / B, and the other two rotations if the rotation speeds of the two rotation members are determined The rotation speed of the member is determined.

The shift operation of the hybrid transmission will be described below with reference to the collinear charts of FIGS. 2 to 5. As the shift operation at the time of forward (forward) rotation output, the EV mode of FIG. 2, the EV-LB mode of FIG. There are four modes, the EIVT mode in FIG. 4 and the EIVT-LB mode in FIG. 5, and there is a REV speed change operation (not shown) for reverse (reverse) rotation output.
In the EV mode of FIG. 2, the engine clutch 9 is disengaged (engine speed Ne = 0) and the low brake L / B is also disengaged as shown in FIG. The output (Out) rotational speed No to the drive system is determined only by the power from both motors / generators MG1, MG2 (or one motor / generator) without using the power from the motor.

  The EV-LB mode in FIG. 3 uses both motors / generators MG1, MG2 (without using the power from the engine ENG (clutch 9) in the state where the low brake L / B is engaged as shown in FIG. Alternatively, in the mode in which the output (Out) rotational speed No. to the drive system is determined only by the power from one motor / generator), the lever accompanying the engagement of the low brake L / B as exemplified by the lever in FIG. Larger torque than EV mode can be output depending on the ratio.

In the EIVT mode of FIG. 4, the engine clutch 9 is engaged and the low brake L / B is released as shown in FIG. 6, and as shown by the lever of FIG. The output (Out) rotation speed No to the drive system is determined by the power from both motors / generators MG1, MG2 (or one motor / generator).
In the EIVT-LB mode shown in FIG. 5, the power from the engine ENG (clutch 9) and both motors / generators MG1, MG2 (or one of them) as in the EIVT mode with the low brake L / B engaged as shown in FIG. This is a mode in which the output (Out) rotation speed No. to the drive system is determined by the power from the motor / generator). As shown in the lever of FIG. Can output a larger torque.

  The REV speed change operation for the reverse (reverse) rotation output is not shown, but the motor / generator MG1 does not depend on the power from the engine ENG (clutch 9) and the motor / generator MG1 does not depend on the low brake L / B released state. This is a shift state in which reverse rotation is output from the carrier C to the output Out by rotation, reverse rotation of the motor / generator MG2, or both.

In the EV mode that uses only the power from the motor / generator MG1, MG2 without the low brake L / B engaged, the torque T1, T2 and the rotation speed N1, N2 of the motor / generator MG1, MG2 are the transmission output torque. It can be obtained by the following equation using To (proportional to the required driving force F) and transmission output speed No (proportional to the vehicle speed VSP).
N2 = {1 / (1 + α)} {− βN1 + (1 + α + β) No} (1)
T1 = {β / (1 + α + β)} To (2)
T2 = {(1 + α) / (1 + α + β)} To (2)
From these equations (1) and (2) and the characteristics of the motor / generators MG1, MG2 and the battery, the EV mode region is set on the two-dimensional coordinates of the vehicle speed VSP and the required driving force F as shown in FIG. Is done.

In the EV-LB mode where the same shifting operation as the EV mode is performed with the low brake L / B engaged, the torques T1, T2 and the rotation speeds N1, N2 of the motor / generators MG1, MG2 are the transmission output torque To and It can be obtained by the following equation using the transmission output speed No. (T _L is the torque of low brake L / B)
N1 = {(1 + α + γ) / γ} No (3)
N2 = {(γ-β) / γ} No (3)
T2 = {1 / (β-γ)} {(1 + α + γ) T1-γTo} (4)
T _L = To-T1-T2 (4)
From these equations (3) and (4) and the characteristics of the motor / generators MG1, MG2 and the battery, the EV-LB mode region is shown on the two-dimensional coordinates of the vehicle speed VSP and the required driving force F as shown in FIG. Set to

In the EIVT mode that uses both the power from the engine ENG (torque Te, rotation speed Ne) and the power from the motor / generator MG1, MG2 without the low brake L / B engaged, the torque of the motor / generator MG1, MG2 T1, T2 and rotation speeds N1, N2 can be obtained by the following equations using transmission output torque To, transmission output rotation speed No, engine torque Te, and engine rotation speed Ne.
N1 = -αNo + (1 + α) Ne (5)
N2 = (1 + β) No-βNe (5)
T1 = {1 / (1 + α + β)} {βTo− (1 + β) Te} (6)
T2 = To-T1-Te (6)
From these formulas (5) and (6) and the characteristics of the motor / generators MG1, MG2 and the battery and the engine ENG, the EIVT mode region is the vehicle speed VSP, the required driving force F, and the battery storage state SOC (power that can be taken out) ) And is represented on the two-dimensional coordinates of the vehicle speed VSP and the required driving force F, for example, as shown in FIG.

In the EIVT-LB mode, which performs the same shifting operation as the EIVT mode with the low brake L / B engaged, the motor / generators MG1, MG2 rotation speeds N1, N2 and engine rotation speed Ne are the transmission output rotation speed No. represented by the following equation (7) using a torque T1, T2 of the motor / generators MG1, MG2, and the transmission output torque to, the engine torque Te, between the torque T _L of the low brake L / B Holds the relationship of the following equation (8).
N1 = {(1 + α + γ) / γ} No (7)
N2 = {(β-γ) / γ} No (7)
Ne = {(1 + γ) / γ} No (7)
T _L = To-T1-T2-Te (8)
T2 = {1 / (β-γ)} {− γTo− (1 + α + γ) T1 + (1 + γ) Te} (8)
The EIVT-LB mode region is determined according to the vehicle speed VSP, the required driving force F, and the battery storage state SOC (carryable power), and can be represented on the two-dimensional coordinates of the vehicle speed VSP and the required driving force F, for example, as shown in FIG. Specially set.

  As is apparent from FIG. 13 in which the above four modes are represented on the same two-dimensional coordinates, in a low vehicle speed and large driving force region where the vehicle speed VSP is less than VSP1 and the required driving force F is F1 or more, EV- A narrow EIVT mode region exists between the LB mode region and the EIVT-LB mode region, and a blank region EM that does not belong to any speed change operation mode may occur in a driving force region larger than the region.

The narrow EIVT mode region between the EV-LB mode region and the EIVT-LB mode region, and the low vehicle speed and large driving force region including the blank region EM are enlarged and conceptually shown as shown in FIG. When the battery storage state SOC (power that can be taken out) is large, as shown by the solid line in FIG. The LB mode area becomes wider, and the EIVT mode area and the blank area EM are narrowed accordingly.
Conversely, when the battery charge state SOC (power that can be taken out) is small, as shown by the broken line in the figure, the area where the EV-LB mode in which electric driving is performed only by the motor / generator becomes narrower. The EIVT mode area and the blank area EM are widened.

However, in any case, in the above-mentioned low vehicle speed and large driving force region, an operation was performed in which the operating point ● is moved as illustrated by lines A and B on FIG. 15 similar to the solid line of FIG. At this time, the shift mode is switched at the point ◯ on the region boundary line.
The line A will be described with reference to FIGS. 16 (a) and 16 (b). When the point A1 is reached from the EV-LB mode region as shown in FIG. 16 (a), the alignment chart of FIG. 16 (b) is obtained. In order to switch from the EV-LB mode illustrated by the solid line above to the EIVT mode illustrated by the broken line on the same collinear diagram, the low brake L / B is released and the engine clutch 9 is engaged, FIG. 16 (a) When point A2 is reached from the EIVT mode area as shown in Fig. 16, switching from the EIVT mode illustrated by the broken line on the collinear diagram of Fig. 16 (b) to the EIVT-LB mode illustrated by the solid line on the same collinear diagram Therefore, fasten the low brake L / B again.
Even when the operating point follows a path opposite to the above along the line A, the low brake L / B state switching similar to the above occurs.

By the way, as described above, in the low vehicle speed and large driving force region, the EIVT mode region between the EV-LB mode region and the EIVT-LB mode region is narrow, and the EV-LB mode, EIVT mode, and EIVT-LB mode It is difficult to switch the state of the low brake L / B necessary for the above-described sequential switching between the two.
As described above with reference to FIG. 14, this tendency is large in the battery storage state SOC (power that can be taken out), and the EV-LB mode area where only the motor / generators MG1 and MG2 are used for electric travel is widened. The smaller the area, the more prominent.

Next, the line B in FIG. 15 will be described with reference to FIGS. 20A and 20B. As shown in FIG. 20A, when the point B1 is reached from the EV-LB mode region, FIG. In order to switch from the EV-LB mode illustrated by the solid line to the EIVT mode indicated by the broken line on the same nomogram, the low brake L / B is released and the engine clutch 9 is engaged, as shown in FIG. As shown in FIG. 20 (a), when the point B2 is reached from the EIVT mode area, no shift mode is selected because it enters the blank area EM, and when the point B3 is reached from the blank area EM, FIG. In order to select the EIVT-LB mode exemplified by the solid line, the low brake L / B is engaged again and the engine clutch 9 is engaged.
Even when the operating point follows the path opposite to the above along the line B, the state switching of the low brake L / B similar to the above occurs.

In this case, because the EIVT mode area and the blank area EM are narrow, in addition to the same problem as described above that it is difficult to switch the state of the low brake L / B necessary for the above-described sequential switching between the shift modes, The following problem arises from passing through the blank area EM.
That is, in the low vehicle speed and large driving force region where the blank region EM exists, it is necessary to quickly start the vehicle with a large driving force from the vehicle speed VSP = 0, or to quickly complete the approach to the highway. Is an important area including cases,
There is a possibility that such a low vehicle speed and large driving force region may become a blank region EM that does not belong to any shift operation mode. As the vehicle speed VSP increases to the EIVT-LB mode lower limit vehicle speed VSP1, as requested. There is a problem that the vehicle cannot be accelerated, and a quick start and an approach to a highway are prevented.

In this embodiment, the low brake L / B state switching is not required when the vehicle enters the EIVT mode region from the EV-LB mode region or the EIVT-LB mode region in the low vehicle speed and large driving force region. The EIVT mode area and the blank area EM are narrow, so that the former problem that it becomes difficult to switch the state of the low brake L / B at the time of the shift mode switching is avoided,
The latter problem due to the presence of the blank area EM, that is, until the vehicle speed VSP rises to the lower limit vehicle speed VSP1 of the EIVT-LB mode area, the vehicle cannot be accelerated as requested, and quick start and high speed The problem that the entry to the road is hindered can also be solved.

  For this reason, in this embodiment, sequential switching between the EV-LB mode, the EIVT mode, and the EIVT-LB mode is required, and it is difficult to switch the state of the low brake L / B necessary for the mode switching. As shown in FIG. 17 (a) corresponding to FIG. 16 (a), when the driving state enters the EIVT mode region during the low vehicle speed and large driving force operation where the EIVT mode region is narrow, as shown in FIG. As shown in FIG. 21A corresponding to a), the EIVT-LB mode area is extended to the EIVT mode area to become the first extended EIVT-LB mode area, and the EIVT-LB mode is also extended to the blank area EM. The area is expanded to become the second extended EIVT-LB mode area.

By the way, these extended EIVT-LB modes are basically EIVT-LB modes, and in this EIVT-LB mode, the vehicle speed VSP and the engine speed Ne are in a proportional relationship.
Since the engine speed Ne has a lower limit value (for example, 800 rpm) and the engine cannot be operated at a lower speed than the lower limit speed (for example, 800 rpm), the lower limit vehicle speed in the EIVT-LB mode region. VSP1 is automatically determined, and the hybrid transmission cannot be operated in the EIVT-LB mode in the first and second extended EIVT-LB mode regions.
Therefore, in this embodiment, in the extended EIVT-LB mode region, the engine speed difference between the input speed of the transmission corresponding to the vehicle speed and the lower limit value of the engine speed is determined so as to match the low vehicle speed of the area. The engine clutch 9 is slip-coupled so that the clutch 9 absorbs, thereby enabling the operation in the EIVT-LB mode without the engine ENG speed Ne being less than the lower limit speed. EIVT-LB mode area can be established.

Shift control in the above-described low vehicle speed and large driving force range, that is, the setting of the first and second extended EIVT-LB mode regions, and the slip coupling of the clutch 9 in these first and second extended EIVT-LB mode regions The shift control system of the hybrid transmission that performs shift control is configured as shown in FIG.
Reference numeral 21 denotes a hybrid controller that controls integrated control of the engine ENG and the hybrid transmission. The hybrid controller 21 relates to a command related to the target torque tTe and target rotational speed tNe of the engine ENG, and to the target torque tTc and target rotational speed tNc of the engine clutch 9. Commands and low brake L / B ON / OFF (engaged, released) commands are supplied to the engine controller 22.
The engine controller 22 operates the engine ENG so that the target values tTe and tNe are achieved, and controls the coupling force of the engine clutch 9 so that the target torque tTc and the target rotational speed tNc are achieved, and the low brake L / B Is controlled ON / OFF (fastened / released) as commanded.

The hybrid controller 21 further supplies a command signal regarding the target torques tT1 and tT2 and the target rotational speeds tN1 and tN2 of the motor / generators MG1 and MG2 to the motor controller 23.
The motor controller 23 controls the motor / generators MG1 and MG2 by the inverter 24 and the battery 25 so that the target torques tT1 and tT2 and the target rotational speeds tN1 and tN2 are achieved.

For this reason, the hybrid controller 21 receives a signal from the accelerator opening sensor 26 that detects the accelerator opening APO from the accelerator pedal depression amount, and a signal from the vehicle speed sensor 27 that detects the vehicle speed VSP (proportional to the output rotational speed No). Then, a signal from the engine rotation sensor 28 for detecting the engine speed Ne is input.
The hybrid controller 21 performs a mode selection and a selection mode so as to realize a driving state desired by the driver based on the required driving force F, the vehicle speed VSP, and the storage state SOC (carryable power) of the battery 25 determined from these input information. The above-described target engine torque tTe and target motor / generator torques tT1, tT2 are determined and commanded by executing the shift control according to the above.
The rotational speed information input to the hybrid controller 21 is not limited to the engine rotational speed Ne and the vehicle speed VSP (output rotational speed No) described above, and the differential device configured by the Ravigneaux type planetary gear set 2 has two degrees of freedom. Therefore, any two rotational speeds of the rotating members in the Ravigneaux planetary gear set 2 may be input to the hybrid controller 21.

FIG. 8 shows a shift control program executed by the hybrid controller 21 at a low vehicle speed and a large driving force range. This control program is a condition for performing a shift at a low vehicle speed and a large drive force range as shown in FIG. It is started when the system is ready, and is repeatedly executed at regular time intervals dt during the operation state in the region.
First, in step S1, it is checked whether or not the operating point is within the EV-LB mode area of FIG.

If the driving state is within the EV-LB mode region, in step S2, the operation is performed on a line representing the maximum driving force Fmax (EV-LB) for each vehicle speed VSP that can be realized in the EV-LB mode as shown in FIG. It is checked whether or not the point is on the board, that is, whether or not the operating point is at a position such as A1 or B1.
If the vehicle is not on the vehicle, the vehicle is still operating in the EV-LB mode region, and the gear shift control targeted by the present invention is unnecessary.

When it is determined in step S2 that the operating point is on the maximum driving force Fmax (EV-LB) line as shown in A1 and B1 of FIG. 15, this time, in step S3, the current vehicle speed VSP is in the EIVT-LB mode region. It is determined whether the vehicle speed is lower than the lower limit vehicle speed VSP1 (see FIG. 15).
If VSP ≧ VSP1, it is the EIVT-LB mode region as apparent from FIG. 15, and the control is terminated as it is because the speed change control targeted by the present invention is unnecessary.
If VSP <VSP1, as is clear from FIG. 15, the operating point in the EV-LB mode region is on the maximum driving force Fmax (EV-LB) line as shown by A1 and B1 in FIG. Since the shift control targeted by the present invention is necessary, the control proceeds to step S4.

In step S4, the timer t for measuring the elapsed time from when the operating point is on the maximum driving force Fmax (EV-LB) line is incremented (incremented) by the aforementioned calculation cycle dt, and the EIVT mode of FIG. The region and the blank region EM are set as a first extended EIVT-LB mode region and a second extended EIVT-LB mode region, respectively, as shown in FIGS. 17 (a) and 21 (a).
These extended EIVT-LB mode areas are set by extending the EIVT-LB mode area adjacent to the high vehicle speed side, and are basically the same as the EIVT-LB mode.

However, in this EIVT-LB mode, the vehicle speed VSP and the engine speed Ne are in a proportional relationship, and at a low vehicle speed lower than the EIVT-LB mode region lower limit vehicle speed VSP1, the engine speed Ne decreases to the inoperable speed. In the second extended EIVT-LB mode region, the hybrid transmission cannot be operated in the EIVT-LB mode that also uses the engine output.
Therefore, in the present embodiment, in the first and second extended EIVT-LB mode regions, the difference in the engine speed between the transmission input engine speed corresponding to the low vehicle speed and the operable lower limit value of the engine engine speed is determined. Thus, the engine clutch 9 is slip-coupled so as to absorb the engine ENG, so that the operation in the EIVT-LB mode is possible even if the engine speed NE of the engine ENG is not less than the operable lower limit speed.

Then, as described above, the EIVT-LB mode area is expanded to the EIVT mode area and the blank area EM, and the first extended EIVT-LB mode area and second area are expanded as shown in FIGS. By setting the extended EIVT-LB mode area, the following effects can be obtained.
That is, as described in the case where the operation point ● is moved as illustrated by the line A in FIG. 17A, when the point A1 is reached from the EV-LB mode region, the operation shown in FIG. Keeping the low brake L / B engaged in order to switch from the EV-LB mode illustrated by the solid line on the alignment chart to the first extended EIVT-LB mode area illustrated by the broken line on the same alignment chart The engine clutch 9 is slip-coupled,
As shown in FIG. 17 (a), when the point A2 is reached from the first extended EIVT-LB mode region, the same values are obtained from the first extended EIVT-LB mode illustrated by broken lines on the alignment chart of FIG. 17 (b). In order to switch to the EIVT-LB mode exemplified by the solid line on the diagram, the engine clutch 9 in the slip coupling state is completely engaged while maintaining the engagement state of the low brake L / B.

If the first extended EIVT-LB mode area is not set in the EIVT mode area in the low vehicle speed and large driving force area, the EIVT mode area is narrow and is between EV-LB mode, EIVT mode, and EIVT-LB mode. Although it is difficult to switch the state of the low brake L / B required for sequential mode switching in
According to this embodiment, since the first extended EIVT-LB mode region is set in the EIVT mode region, the low brake L / B can be kept engaged as described above, and the state of the low brake L / B can be maintained. The problem that switching becomes difficult can be avoided.
In addition, since the engine clutch 9 is not fully engaged and slip-coupled in the first extended EIVT-LB mode, the engine speed does not decrease to an inoperable speed even at a low vehicle speed, and the first extended EIVT- The LB mode area can be established.

Next, in the case where the operation of moving the operating point ● is performed as illustrated by the line B on FIG. 21 (a), when the point B1 is reached from the EV-LB mode region, In order to switch from the EV-LB mode illustrated by the solid line on the diagram to the first extended EIVT-LB mode illustrated by the broken line on the same collinear diagram, the engine clutch 9 is maintained with the low brake L / B engaged. Slip-join and
As shown in FIG. 21 (a), after reaching the point B2 from the first extended EIVT-LB mode area, the control is the same as the control in the first extended EIVT-LB mode area since it enters the second extended EIVT-LB mode area. When control is performed and the point B3 is reached from the second extended EIVT-LB mode region, the second extended EIVT-LB mode illustrated by a broken line on the alignment chart of FIG. 21 (b) is a solid line on the same alignment chart. In order to switch to the EIVT-LB mode exemplified in (1), the engine clutch 9 is completely engaged with the low brake L / B engaged.

When the first extended EIVT-LB mode region and the second extended EIVT-LB mode region are not set in the EIVT mode region and the blank region EM in the low vehicle speed and large driving force region, the EIVT mode region and the blank region EM are narrow. While it is difficult to switch the state of the low brake L / B required for sequential mode switching between EV-LB mode, EIVT mode, no control mode without shift mode, and EIVT-LB mode,
According to this embodiment, in order to set the first extended EIVT-LB mode area in the EIVT mode area and the second extended EIVT-LB mode area in the blank area EM, the low brake L / B is engaged as described above. The state can be maintained, and the problem that it becomes difficult to switch the state of the low brake L / B can be avoided.
In addition, since the engine clutch 9 is not completely engaged in the first and second extended EIVT-LB modes and is slip-coupled, the engine speed does not decrease to the inoperable speed even at a low vehicle speed. An extended EIVT-LB mode area can be established.

In the present embodiment, the following effects can also be achieved by setting the second extended EIVT-LB mode area in the blank area EM.
In other words, the low vehicle speed and large driving force region where the blank region EM exists is used when the vehicle is started quickly with a large driving force from the vehicle speed VSP = 0, or when the entry to the expressway needs to be completed promptly. Are important areas including
In such a low vehicle speed and large driving force region, which is a blank region EM that does not belong to any shift operation mode, the vehicle is accelerated as required until the vehicle speed VSP rises to the EIVT-LB mode region lower limit vehicle speed VSP1. And the problem of impeding prompt start and entry to the highway.
However, in this embodiment, since the second extended EIVT-LB mode area is set in the blank area EM, the control similar to the EIVT-LB mode (slip coupling of the engine clutch 9 for preventing engine stall) is performed in this area as described above. Until the vehicle speed VSP increases to the lower limit vehicle speed VSP1 of the EIVT-LB mode, the vehicle cannot be accelerated as required due to the uncontrolled state. It is possible to eliminate the problem of impeding entry to the highway.

When it is determined in step S1 of FIG. 8 that the vehicle is not in the EV-LB mode region, whether or not the EIVT-LB mode is selected in step S5, and in step S6, the vehicle speed VSP is set to the EIVT-LB mode. Check whether the vehicle speed is below the lower limit vehicle speed VSP1.
When it is determined in step S5 that the EIVT-LB mode is being selected and it is determined in step S6 that the vehicle speed VSP is greater than or equal to the EIVT-LB mode region lower limit vehicle speed VSP1, it is ensured that the EIVT-LB is surely shown in FIG. Since there is an operation state in the mode region, which is different from the speed change targeted by the present invention, the control is terminated as it is.

However, even if it is determined in step S5 that the EIVT-LB mode is selected, if it is determined in step S6 that the vehicle speed VSP is less than the EIVT-LB mode region lower limit vehicle speed VSP1, the current required driving force F is determined in step S7. 15, whether or not it is equal to or higher than the maximum driving force Fmax (EV-LB) for each vehicle speed VSP that can be realized in the EV-LB mode as shown in FIG. 15, that is, as is clear from FIG. Check if there is an operating condition in area EM.
When it is determined in step S7 that F ≧ Fmax (EV-LB) (when it is the EIVT mode region or the blank region EM in FIG. 15), the shift control according to the present invention is required. The second extended EIVT-LB mode area is set, and the same operation as described above with reference to FIGS. 17 and 21 is executed to obtain the intended effect.
When it is determined in step S7 that F <Fmax (EV-LB) (in the EV-LB mode region of FIG. 15), the shift control according to the present invention is unnecessary, and the control is terminated as it is.

If it is determined in step S5 that a mode other than the EIVT-LB mode is selected, it is determined in step S8 whether the first or second extended EIVT-LB mode is selected.
If none of these extended EIVT-LB modes is selected, the control is terminated as it is. However, if any one of the extended EIVT-LB modes is selected, the engine clutch 9 is slip-coupled as described above in this mode. Therefore, there are concerns about temperature problems due to heat generation and problems regarding durability of the clutch.

Therefore, if it is determined in step S8 that any of the extended EIVT-LB modes is selected, the control proceeds to step S9, and the extended EIVT-LB mode selection time at which measurement is started in step S4 (for convenience, this time It is checked whether or not (indicated by the same symbol t as the timer for measuring) is equal to or longer than the set time τ.
Here, the set time τ is set to the lower limit value of the time when the amount of heat generated by the slip coupling of the engine clutch 9 becomes a problem.

  While it is determined in step S9 that the extended EIVT-LB mode selection time t is less than the set time τ, the amount of heat generated by slip coupling of the engine clutch 9 does not matter, so the control is terminated as it is. If it is determined that the EIVT-LB mode selection time t has exceeded the set time τ, the amount of heat generated by slip coupling of the engine clutch 9 starts to become a problem. 9 slip coupling is terminated.

In step S10, is the operating point (operating state) in the first extended EIVT-LB mode region as indicated by A3 in FIG. 18 or in the second extended EIVT-LB mode region as indicated by B4 in FIG. Check.
When it is determined in step S10 that the region is the first extended EIVT-LB mode region, that is, as shown in FIG. 18, a long time longer than the set time τ is required for the operating point to reach the current A3 from A1 on the line A. In the meantime, if the amount of heat generated by the engine clutch 9 to be slip-coupled begins to become a problem, the control proceeds to step S11, the extended EIVT-LB mode selection time measurement timer t is reset to 0, and as shown in FIG. The first extended EIVT-LB mode area is returned to the EIVT mode area, and the second extended EIVT-LB mode area is returned to the blank area EM.
Thus, by returning the first extended EIVT-LB mode region to the EIVT mode region, the shift control is switched to the control based on the EIVT mode, and the engine clutch 9 is released, so that the above heat generation problem can be avoided. .

In this embodiment, the blank area EM is made the second extended EIVT-LB mode area in step S4, and the second extended EIVT-LB mode area is returned to the blank area EM in step S11. Even if the blank area EM is permanently set as the second extended EIVT-LB mode area, there is no problem in terms of control.
Rather, it is more convenient to eliminate the blank area EM and make it the second extended EIVT-LB mode area permanently, not only for control, but also to avoid the above-mentioned problem of insufficient driving force in the area. .

When it is determined in step S10 that the region is the second extended EIVT-LB mode region, that is, as shown in FIG. 22, there is a long time longer than the set time τ for the operating point on the line B from B1 to the current B4. In the meantime, if the amount of heat generated by the engine clutch 9 to be slip-coupled starts to become a problem, the control is advanced to step S12 and thereafter.
In step S12, it is necessary to generate the maximum driving force under the current vehicle speed VSP (at the operating point B4 in FIG. 22) based on the reference map of FIG. 15 before setting both extended EIVT-LB mode regions. To obtain the correct mode mode-max.

Incidentally, the maximum driving force generation mode mode-max corresponding to the current operating point indicated by B4 in FIG. 22 is an EIVT mode corresponding to the EIVT mode area (see FIG. 15) before becoming the first extended EIVT-LB mode area. is there.
If the current operating point is located near the boundary between the EV-LB mode region and the second extended EIVT-LB mode region in FIG. 22, the maximum driving force generation mode mode-max is the EV-LB mode. EV-LB mode corresponding to the area.

In the next step S13, it is checked whether the maximum driving force generation mode mode-max obtained in step S12 is the EIVT mode or the EV-LB mode.
When the maximum driving force generation mode mode-max is the EIVT mode, the same processing as step S11 is performed in step S14, the extended EIVT-LB mode selection time measurement timer t is reset to 0, and as shown in FIG. The first extended EIVT-LB mode area is returned to the EIVT mode area, and the second extended EIVT-LB mode area is returned to the blank area EM.

However, since the operating point B4 is located in the blank area EM just by returning the first extended EIVT-LB mode area to the EIVT mode area in this way, it is important that the problem related to the heat generation of the engine clutch 9 is solved. The above-mentioned problem relating to insufficient output cannot be solved.
In step S15, the target driving force F is reduced from the value corresponding to the current operating point B4 to the maximum driving force Fmax (EIVT) obtained in the EIVT mode under the current vehicle speed VSP. The operating point is moved from B4 in the blank area EM to B5 in the EIVT mode area while minimizing.
By shifting the operating point to the EIVT mode region, the shift control is switched to the control based on the EIVT mode, and the engine clutch 9 is released, so that the above heat generation problem can be avoided, and the output is insufficient due to stopping in the blank region EM. Can be avoided.

In this embodiment, the blank area EM is made the second extended EIVT-LB mode area in step S4, and the second extended EIVT-LB mode area is returned to the blank area EM in step S14. Therefore, even if the blank area EM is permanently set as the second extended EIVT-LB mode area without such switching, there is no problem in control.
Rather, it is more convenient to eliminate the blank area EM and make it the second extended EIVT-LB mode area permanently, not only for control, but also to avoid the above-mentioned problem of insufficient driving force in the area. .

  If it is determined in step S13 that the maximum driving force generation mode mode-max is the EV-LB mode, the same process as in step S11 is performed in step S16, and the extended EIVT-LB mode selection time measurement timer t is reset to zero. At the same time, as shown in FIG. 23, the first extended EIVT-LB mode area is returned to the EIVT mode area, and the second extended EIVT-LB mode area is returned to the blank area EM.

However, if the first extended EIVT-LB mode area is simply returned to the EIVT mode area, the operating point is located in the blank area EM as in the case described above, so the problem related to the heat generation of the engine clutch 9 is solved. However, it is impossible to solve the above-mentioned problem related to the insufficient output.
Therefore, in step S17, the target driving force F is reduced from the value corresponding to the current operating point to the maximum driving force Fmax (EV-LB) (see FIG. 23) obtained in the EV-LB mode under the current vehicle speed VSP. As a result, the operating point is moved from the blank area EM to the EV-LB mode area while minimizing the decrease in driving force.
By shifting the operating point to the EV-LB mode region, the shift control is switched to the control based on the EV-LB mode, and the engine clutch 9 is completely engaged, so that the above heat generation problem can be avoided and the blank region EM It is possible to avoid the situation where the output stops and the output is insufficient.

In this embodiment, the blank area EM is made the second extended EIVT-LB mode area in step S4, and the second extended EIVT-LB mode area is returned to the blank area EM in step S16. Therefore, even if the blank area EM is permanently set as the second extended EIVT-LB mode area without such switching, there is no problem in control.
Rather, it is more convenient to eliminate the blank area EM and make it the second extended EIVT-LB mode area permanently, not only for control, but also to avoid the above-mentioned problem of insufficient driving force in the area. .

  By the way, the control program of FIG. 8 is a shift control in consideration of the case where the operating state is changed so that the operating point moves from the left side of the drawing to the right along the line A or B of FIG. Needless to say, even when the driving state is changed so as to move in the reverse direction along the line A or B, it is possible to construct a shift control based on the same concept, and the same operational effect can be obtained thereby. .

1 is a diagrammatic configuration diagram of a hybrid transmission to which a shift control device according to the present invention can be applied. FIG. 3 is a collinear diagram when the hybrid transmission is in an EV mode. FIG. 3 is a collinear diagram for the hybrid transmission in an EV-LB mode. FIG. 3 is a collinear diagram when the hybrid transmission is in an EIVT mode. FIG. 3 is a collinear diagram for the hybrid transmission in an EIVT-LB mode. It is explanatory drawing which shows the relationship between the combination of engagement and releasing of the engine clutch and low brake in the hybrid transmission, and a shift control mode. It is a block diagram which shows the control system of the hybrid transmission. 5 is a flowchart of a shift control program executed by the hybrid controller in the control system at a low vehicle speed and a large driving force range. It is an area diagram showing an EV mode area. It is an area diagram showing an EV-LB mode area. It is an area diagram showing an EIVT mode area area. It is an area diagram showing an EIVT-LB mode area. FIG. 13 is an area diagram in a case where the four-mode area shown in FIGS. 9 to 12 is displayed on the same drawing and a blank area is generated. FIG. 14 is an enlarged schematic diagram of a region diagram in a low vehicle speed and large driving force region around a blank region in FIG. 13. It is a diagram which shows the example of a change of the driving | running state in which the speed change made into a control object generate | occur | produces on the same diagram as FIG. 15A and 15B are diagrams for explaining a change state of a shift operation mode that is normally performed when there is a change in the driving state indicated by A. FIG. 15A is a region diagram similar to FIG. 15, and FIG. FIG. 6 is a collinear diagram similar to FIGS. 15A and 15B are diagrams for explaining a change state of the shift operation mode by the shift control of the present invention when there is a change in the driving state indicated by A. FIG. 15A is a region diagram similar to FIG. ) Is a collinear diagram similar to FIGS. FIG. 18 is a region diagram similar to FIG. 15 used to explain a situation in which heat generation of the engine clutch becomes a problem as a result of the shift control according to the present invention shown in FIG. 17. FIG. 16 is a region diagram similar to FIG. 15 showing shift control for avoiding the heat generation problem of the engine clutch. 15A and 15B are diagrams for explaining a change state of a shift operation mode that is normally performed when there is a change in an operation state indicated by B. FIG. 15A is a region diagram similar to FIG. 15, and FIG. FIG. 6 is a collinear diagram similar to FIGS. 15A and 15B are diagrams for explaining a change state of the shift operation mode by the shift control of the present invention when there is a change in the operation state indicated by B. FIG. 15A is a region diagram similar to FIG. ) Is a collinear diagram similar to FIGS. FIG. 16 is a region diagram similar to FIG. 15 used to explain a situation in which heat generation of the engine clutch becomes a problem as a result of the shift control according to the present invention shown in FIG. 21. FIG. 16 is a region diagram similar to FIG. 15 showing shift control for avoiding the heat generation problem of the engine clutch.

Explanation of symbols

1 Transmission case 2 Ravigneaux type planetary gear set (differential device)
3 Composite current 2-layer motor
ENG engine (main power source)
4 Single pinion planetary gear set 5 Double pinion planetary gear set 6 Countershaft 7 Differential gear unit 8 Drive wheel 9 Engine clutch
14 Output gear
MG1 1st motor / generator
MG2 Second motor / generator
S1 sun gear
S2 sun gear
P1 short pinion
P2 Long pinion
R1 ring gear
R2 ring gear
C career
L / B Low brake
21 Hybrid controller
22 Engine controller
23 Motor controller
24 inverter
25 battery
26 Accelerator position sensor
27 Vehicle speed sensor
28 Engine rotation sensor

Claims (7)

A two-degree-of-freedom differential device having a plurality of rotating members as rotating members arranged on the nomograph, and determining the rotating state of the other members when the rotating state of two members is determined among these rotating members Of the rotating members, one of the two rotating members located on the inner side of the collinear diagram is coupled to the input from the main power source via the clutch, and the other is coupled to the output to the drive system. Two motors / generators are coupled to each of the two rotating members positioned on the outer side of the diagram, and on the collinear diagram, the rotating member coupled with the output and an output close to the output on the nomographic diagram A low brake is connected to the rotating member between the rotating member combined with the side motor / generator,
EIVT-LB mode that determines the power to the output using the power from the main power source and the power from both motors / generators via the clutch in a state where the low brake is engaged,
EV-LB mode that determines the power to the output using only the power from the motors / generators with the low brake engaged,
In a hybrid transmission having at least an EIVT mode that determines power to the output using power from a main power source and power from both motors / generators via the clutch in a state where the low brake is released,
Low vehicle speed with a narrow EIVT mode area, which requires sequential switching between the EV-LB mode, EIVT mode, and EIVT-LB mode, making it difficult to switch the state of the low brake required for mode switching. When the driving state enters the EIVT mode area during driving with a large driving force, the EIVT-LB mode area is expanded to the EIVT mode area to form the first extended EIVT-LB mode area. A shift control apparatus for a hybrid transmission, characterized in that the clutch is slip-coupled so that the rotational speed of the main power source is maintained at an operable speed even at the low vehicle speed in an extended EIVT-LB mode region.   2. The shift control apparatus according to claim 1, wherein when the clutch slip coupling in the first extended EIVT-LB mode region continues for a set time or longer, the first extended EIVT-LB mode region is returned to the EIVT mode region. A shift control apparatus for a hybrid transmission, characterized in that it is configured.   The shift control device according to claim 1, wherein the driving state is changed from the first extended EIVT-LB mode area to a blank area between which the EV-LB mode area and the EIVT-LB mode area are not set. When entering, the EIVT-LB mode area is expanded into this blank area to form a second extended EIVT-LB mode area, and the rotational speed of the main power source is reduced in the second extended EIVT-LB mode area. A shift control apparatus for a hybrid transmission, characterized in that the clutch is slip-coupled so as to maintain a drivable speed even at a vehicle speed.   4. The shift control apparatus according to claim 3, wherein the blank area is permanently defined as a second extended EIVT-LB mode area.   5. The shift control device according to claim 3, wherein when the clutch slip coupling in the second extended EIVT-LB mode region continues for a set time or longer, the first extended EIVT-LB mode region is changed to the EIVT mode region. Shifting the hybrid transmission characterized in that the driving state is changed to the operating point in the EIVT mode region or EV-LB mode region where a large driving force can be obtained at the current vehicle speed. Control device.   6. The shift control apparatus according to claim 5, wherein the change of the driving state is performed by changing the required driving force, and the required driving force is changed in the selected EIVT mode or EV-LB mode based on the current vehicle speed. A shift control device for a hybrid transmission, characterized in that it is configured to correspond to the maximum driving force that can be obtained.   The hybrid control device according to any one of claims 2, 5, and 6, wherein the set time is set to a lower limit value of a time at which a heat generation amount due to slip coupling of the clutch becomes a problem. A transmission control device for a transmission.

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