JP2016070439A - Control device of power split type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a power split type continuously variable transmission, capable of improving travel fuel economy and drivability in a power split mode.SOLUTION: When a vehicle travels on an intermittently uphill road, a power transmission mode of a power split type continuously variable transmission does not change from a belt node to a split mode. Therefor, the split mode is changed to the belt mode while the vehicle travels on an intermittently uphill road, or the vehicle comes to an intermittently uphill road while traveling in the belt mode, and after that, until the vehicle passes through the intermittently uphill road, the belt mode is kept.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control device for a power split type continuously variable transmission.

  As a transmission mounted on a vehicle such as an automobile, a continuously variable transmission mechanism that continuously changes engine power, a gear mechanism that transmits engine power without going through a continuously variable transmission mechanism, and a continuously variable transmission mechanism There has been proposed a planetary gear mechanism for synthesizing the power from the gear and the power from the gear mechanism. In this transmission, the power from the engine can be divided into a continuously variable transmission mechanism and a gear mechanism, and the divided powers can be combined by the planetary gear mechanism and transmitted to the wheels.

Japanese Patent No. 4552376

  The present applicant has also proposed a transmission capable of dividing and transmitting the power of the drive source into two systems as a power split type continuously variable transmission.

  The power split type continuously variable transmission according to the proposal includes a continuously variable transmission mechanism that continuously changes power by changing a transmission ratio, a constant transmission mechanism that changes power at a constant transmission ratio, and a continuously variable transmission mechanism. And a synthesizing gear mechanism including a planetary gear mechanism for synthesizing the motive power from and the power from the constant speed change mechanism. The power (rotation) output from the continuously variable transmission mechanism is input to the sun gear of the synthesizing gear mechanism. An output shaft is connected to the ring gear of the synthesizing gear mechanism. The rotation of the output shaft is transmitted to the differential gear, and is transmitted from the differential gear to the left and right drive wheels.

  In this power split type continuously variable transmission, the belt mode in which power is transmitted to the synthesizing gear mechanism only through the continuously variable transmission mechanism, and the synthesizing gear via the continuously variable transmission mechanism and the constant transmission mechanism. The mode is switched to the split mode transmitted to the mechanism.

  In the belt mode, the sun gear and the ring gear of the synthesizing gear mechanism are directly connected, and the carrier of the synthesizing gear mechanism is brought into a free state. Therefore, the sun gear and the ring gear rotate integrally with the power output from the continuously variable transmission mechanism, and the output shaft rotates integrally with the ring gear. Therefore, in the belt mode, the gear ratio of the power split continuously variable transmission matches the gear ratio of the continuously variable transmission mechanism.

  When the speed ratio of the continuously variable transmission mechanism is changed to a constant speed ratio, the belt mode is switched to the split mode. In the split mode, the power from the constant speed change mechanism is input to the carrier of the synthesizing gear mechanism. Since the gear ratio of the constant speed change mechanism is constant and unchanged, if the rotational speed input to the power split continuously variable transmission is constant, the rotational speed of the carrier is kept constant. Therefore, when the gear ratio of the continuously variable transmission mechanism is increased from the minimum gear ratio and the rotation speed of the sun gear of the synthesizing gear mechanism is decreased, the rotation speed of the output gear connected to the ring gear and the ring gear of the synthesizing gear mechanism is reduced. As a result, the gear ratio of the power split type continuously variable transmission decreases. Therefore, in the split mode, the gear ratio of the power split type continuously variable transmission can be lowered as compared with the belt mode, and the running fuel consumption of the vehicle is improved.

  However, in the split mode, since the gear ratio is small, the torque transmitted to the drive wheels is small. Further, due to the gear ratio of the synthesizing gear mechanism (planetary gear mechanism), the speed change rate of the power split continuously variable transmission is lower than the speed change rate of the continuously variable transmission mechanism. Therefore, when the vehicle travels in the split mode, the acceleration of the vehicle with respect to the accelerator operation is slow depending on the traveling state, and the driver may need to frequently repeat the accelerator operation with a relatively large operation amount.

  An object of the present invention is to provide a control device for a power split type continuously variable transmission that can achieve both improvement in driving fuel efficiency and driveability in a power split mode (split mode).

  In order to achieve the above object, a control device for a power split type continuously variable transmission according to the present invention includes a continuously variable transmission mechanism for continuously changing power input to an input shaft by changing a transmission ratio, and an input shaft. And a synthesizing gear mechanism including a constant speed change mechanism for shifting the input power at a constant speed ratio, and a planetary gear mechanism for synthesizing the power from the continuously variable speed change mechanism and the power from the constant speed change mechanism. A continuously variable transmission mode in which the power input to the shaft is transmitted to the synthesizing gear mechanism via the continuously variable transmission mechanism, and the power input to the input shaft is combined via the continuously variable transmission mechanism and the constant transmission mechanism. For a vehicle equipped with a power split continuously variable transmission configured to be able to switch to a power split mode that shifts the power that is transmitted to the gear mechanism and input to the input shaft with a smaller speed ratio than the continuously variable speed mode. Applied power split continuously variable transmission A control device for determining whether or not the vehicle is traveling on the uphill intermittent road where the uphill road is intermittent, and the determination means determines that the vehicle is traveling on the uphill intermittent road And a prohibiting means for prohibiting switching from the continuously variable transmission mode to the power split mode.

  According to this configuration, when the vehicle is traveling on an uphill intermittent road where the uphill road is intermittent (a road on which an uphill road and a downhill road or a flat road are repeated), the power transmission mode of the power split type continuously variable transmission Cannot be switched from the continuously variable transmission mode to the power split mode. Therefore, if the vehicle is switched from the power split mode to the continuously variable transmission mode while traveling on the uphill intermittent road, or if the vehicle approaches the uphill intermittent road while traveling in the continuously variable transmission mode, the vehicle is The continuously variable transmission mode is maintained until the intermittent path is exited. This allows the vehicle to be accelerated with good responsiveness to the driver's accelerator operation while the vehicle is traveling on an uphill break, and the driver must frequently repeat the accelerator operation with a relatively large amount of operation. Can be eliminated. As a result, it is possible to improve drivability on an uphill intermittent road where the uphill road is intermittent.

  On the other hand, when the vehicle is traveling on a road other than an uphill intermittent road, the power transmission mode travels from the continuously variable transmission mode to the power split mode, so that the fuel consumption of the vehicle can be improved.

  Therefore, it is possible to achieve both improved driving fuel efficiency and improved drivability in the power split mode.

  According to the present invention, it is possible to achieve both improvement in driving fuel consumption and improvement in drivability in the power split mode.

It is a skeleton figure which shows the structure of the drive system of the vehicle to which the control apparatus which concerns on one Embodiment of this invention is applied. It is a figure which shows the state of the high brake, reverse brake, and low clutch at the time of advance of a vehicle, and reverse drive. It is a collinear diagram which shows the relationship of the rotation speed of the sun gear of a synthetic | combination gear mechanism, a carrier, and a ring gear. It is a block diagram which shows the principal part of the electrical structure of a vehicle. It is a flowchart which shows the flow of a split mode prohibition process.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a skeleton diagram showing a configuration of a drive system of a vehicle 1 to which a control device according to an embodiment of the present invention is applied.

  The vehicle 1 is an automobile that uses an engine (E / G) 2 as a power source. The vehicle 1 is equipped with a torque converter 3 and a power split type continuously variable transmission 4.

  The torque converter 3 includes a torque converter input shaft 11, a torque converter output shaft 12, a pump impeller 13, a turbine runner 14, and a lockup clutch 15. The torque converter input shaft 11 and the torque converter output shaft 12 are provided so as to be rotatable about the same rotational axis as the output shaft 16 of the engine 2 (hereinafter referred to as “E / G output shaft 16”). An E / G output shaft 16 is connected to the torque converter input shaft 11. A torque converter input shaft 11 is connected to the center of the pump impeller 13, and the pump impeller 13 is provided to be rotatable integrally with the torque converter input shaft 11. The torque converter output shaft 12 is connected to the center of the turbine runner 14, and the turbine runner 14 is provided to be rotatable integrally with the torque converter output shaft 12. When the lockup clutch 15 is engaged, the pump impeller 13 and the turbine runner 14 are directly connected, and when the lockup clutch 15 is released, the pump impeller 13 and the turbine runner 14 are separated.

  When power is input from the E / G output shaft 16 to the torque converter input shaft 11 in a state where the lockup clutch 15 is released, the torque converter input shaft 11 and the pump impeller 13 rotate. When the pump impeller 13 rotates, an oil flow from the pump impeller 13 toward the turbine runner 14 is generated. This oil flow is received by the turbine runner 14 and the turbine runner 14 rotates. At this time, the amplifying action of the torque converter 3 occurs, and the turbine runner 14 generates a power larger than the power (torque) input to the torque converter input shaft 11. The power of the turbine runner 14 is output from the torque converter output shaft 12.

  In a state where the lock-up clutch 15 is engaged, when power is input from the E / G output shaft 16 to the torque converter input shaft 11, the torque converter input shaft 11, the pump impeller 13, and the turbine runner 14 rotate together. . The power generated by the rotation of the turbine runner 14 is output from the torque converter output shaft 12.

  The power split type continuously variable transmission 4 transmits the power output from the torque converter 3 to the differential gear 5. The power split type continuously variable transmission 4 includes a T / M input shaft 21, a T / M output shaft 22, a continuously variable transmission mechanism 23, a constant transmission mechanism 24, and a synthesizing gear mechanism 25.

  The torque converter output shaft 12 is connected to the T / M input shaft 21.

  The T / M output shaft 22 is provided in parallel with the T / M input shaft 21.

  The continuously variable transmission mechanism 23 has the same configuration as a known belt-type continuously variable transmission (CVT). Specifically, the continuously variable transmission mechanism 23 is supported by the primary shaft 31 connected to the T / M input shaft 21, the secondary shaft 32 provided in parallel with the primary shaft 31, and the primary shaft 31 so as not to be relatively rotatable. A primary pulley 33, a secondary pulley 34 supported so as not to rotate relative to the secondary shaft 32, and a belt 35 wound around the primary pulley 33 and the secondary pulley 34.

  The constant speed change mechanism 24 includes a planetary gear mechanism 41, a split drive gear 42, a split driven gear 43, and an idle gear 44.

  The planetary gear mechanism 41 includes a carrier 45, a sun gear 46, and a ring gear 47. The carrier 45 is supported by the T / M input shaft 21 so as not to be relatively rotatable. The carrier 45 supports a plurality of pinion gears 48 so as to be rotatable. The plurality of pinion gears 48 are arranged at equiangular intervals on the circumference. The sun gear 46 is externally fitted to the T / M input shaft 21 so as to be relatively rotatable, and meshes with each pinion gear 48 from the inside in the rotational radial direction of the T / M input shaft 21. The ring gear 47 has an annular shape surrounding the carrier 45, and meshes with each pinion gear 48 from the outside in the rotational radial direction of the T / M input shaft 21.

  The split drive gear 42 is provided so as to be able to rotate integrally with the sun gear 46.

  The split driven gear 43 is provided on the outer periphery of the carrier 51 of the synthesizing gear mechanism 25 described below so as to be able to rotate integrally with the carrier 51.

  The idle gear 44 meshes with the split drive gear 42 and the split driven gear 43.

  The synthesizing gear mechanism 25 has a configuration of a planetary gear mechanism. That is, the synthesizing gear mechanism 25 includes a carrier 51, a sun gear 52, and a ring gear 53. The secondary shaft 32 of the continuously variable transmission mechanism 23 is inserted into the center of the carrier 51 so as to be relatively rotatable. The carrier 51 rotatably supports a plurality of pinion gears 54. The plurality of pinion gears 54 are arranged at equal angular intervals on the circumference. The sun gear 52 is supported by the secondary shaft 32 so as not to be relatively rotatable, and meshes with each pinion gear 54 from the inner side in the rotational radial direction of the secondary shaft 32. The ring gear 53 has an annular shape that surrounds the periphery of the carrier 51, and meshes with each pinion gear 54 from the outside in the rotational radial direction of the secondary shaft 32. One end of the T / M output shaft 22 is connected to the center of the ring gear 53, and the ring gear 53 is provided so as to be able to rotate integrally with the T / M output shaft 22. An output gear 55 is supported at the other end of the T / M output shaft 22 so as not to be relatively rotatable.

  The rotation of the output gear 55 is transmitted to the differential gear 5 via the idle gear mechanism 6. The idle gear mechanism 6 includes an idle shaft 61 provided in parallel with the T / M output shaft 22, and a first idle gear 62 and a second idle gear 63 that are supported by the idle shaft 61 so as not to rotate relative to each other. . The first idle gear 62 meshes with the output gear 55. The second idle gear 63 meshes with a ring gear 64 provided in the differential gear 5.

  The power split type continuously variable transmission 4 includes a high brake HB, a reverse brake RB, and a low clutch LC.

  The high brake HB is switched between an engaged state (on) in which the ring gear 47 is braked and a released state (off) in which the ring gear 47 is allowed to rotate.

  The reverse brake RB is switched between an engaged state (on) in which the split drive gear 42 (sun gear 46) is braked and a released state (off) in which the split drive gear 42 is allowed to rotate.

  The low clutch LC is switched between an engaged state (ON) in which the T / M output shaft 22 and the secondary shaft 32 are directly connected, and a released state (OFF) in which the direct connection is released.

  FIG. 2 is a diagram illustrating states of the high brake HB, the reverse brake RB, and the low clutch LC when the vehicle 1 is moving forward and backward.

  In FIG. 2, “◯” indicates that the high brake HB, the reverse brake RB, and the low clutch LC are engaged.

  The power split type continuously variable transmission 4 has a belt mode (continuously variable transmission mode) and a split mode (power split mode) as power transmission modes when the vehicle 1 moves forward.

  In the belt mode, the high brake HB and the reverse brake RB are released. Then, the low clutch LC is engaged. Thereby, the T / M output shaft 22 and the secondary shaft 32 are directly connected.

  The power input to the T / M input shaft 21 is transmitted to the primary shaft 31 of the continuously variable transmission mechanism 23 to rotate the primary shaft 31 and the primary pulley 33. The rotation of the primary pulley 33 is transmitted to the secondary pulley 34 via the belt 35 and rotates the secondary pulley 34 and the secondary shaft 32. Since the low clutch LC is engaged, the T / M output shaft 22 rotates integrally with the secondary shaft 32. The rotation of the T / M output shaft 22 is transmitted to the ring gear 64 of the differential gear 5 through the output gear 55, the first idle gear 62, the idle shaft 61 and the second idle gear 63. Thereby, the drive shafts 71 and 72 of the vehicle 1 rotate in the forward direction.

  Switching from the belt mode to the split mode is performed in a state where the transmission ratio of the continuously variable transmission mechanism 23 matches the transmission ratio of the constant transmission mechanism 24. The transmission ratio of the constant transmission mechanism 24 is set to the same transmission ratio as the minimum transmission ratio of the continuously variable transmission mechanism 23, for example.

  In the split mode, the high brake HB is engaged, and the reverse brake RB and the low clutch LC are released. When the high brake HB is engaged, the ring gear 47 of the constant speed change mechanism 24 is braked. Further, when the low clutch LC is released, the direct connection between the T / M output shaft 22 and the secondary shaft 32 is released.

  The power input to the T / M input shaft 21 is transmitted to the primary shaft 31 of the continuously variable transmission mechanism 23 to rotate the primary shaft 31 and the primary pulley 33. The rotation of the primary pulley 33 is transmitted to the secondary pulley 34 via the belt 35 and rotates the secondary pulley 34 and the secondary shaft 32. As the secondary shaft 32 rotates, the sun gear 52 of the synthesizing gear mechanism 25 rotates.

  Further, since the ring gear 47 of the constant speed change mechanism 24 is braked, the power input to the T / M input shaft 21 causes the carrier 45 of the constant speed change mechanism 24 to revolve and the pinion gear held by the carrier 45. 48 is rotated. As the pinion gear 48 rotates, power is input from the pinion gear 48 to the sun gear 46. As a result, the pinion gear 48 and the split drive gear 42 rotate. The rotation of the split drive gear 42 is transmitted to the split driven gear 43 via the idle gear 44 of the constant speed change mechanism 24 to rotate the split driven gear 43 and the carrier 51.

  Since the switching from the belt mode to the split mode is performed in a state where the transmission ratio of the constant transmission mechanism 24 matches the transmission ratio of the continuously variable transmission mechanism 23, immediately after the switching, the carrier 51 of the synthesizing gear mechanism 25, The sun gear 52 and the ring gear 53 rotate at the same speed. Then, the T / M output shaft 22 rotates integrally with the ring gear 53. The rotation of the T / M output shaft 22 is transmitted to the ring gear 64 of the differential gear 5 through the output gear 55, the first idle gear 62, the idle shaft 61 and the second idle gear 63. Thereby, the drive shafts 71 and 72 of the vehicle 1 rotate in the forward direction.

  Since the speed ratio of the constant speed change mechanism 24 is constant and unchanged (fixed), in the split mode, if the power input to the T / M input shaft 21 is constant, the rotation of the carrier 51 of the synthesizing gear mechanism 25 is prevented. It is held at a constant speed. When the transmission ratio of the continuously variable transmission mechanism 23 is increased and the rotational speed of the sun gear 52 of the synthesizing gear mechanism 25 decreases as shown in FIG. 3, the ring gear 53 (T / M output shaft of the synthesizing gear mechanism 25). 22) the rotational speed is increased and the gear ratio of the power split type continuously variable transmission 4 is decreased. Conversely, when the speed ratio of the continuously variable transmission mechanism 23 is lowered and the rotational speed of the sun gear 52 is increased, the rotational speed of the ring gear 53 (T / M output shaft 22) is decreased, and the power split type continuously variable transmission 4 The gear ratio increases. Therefore, the power split type continuously variable transmission 4 can have a large speed ratio width.

  Further, during reverse travel, the high brake HB and the low clutch LC are released. Then, the reverse brake RB is engaged. Thereby, the split drive gear 42 (sun gear 46) is braked. Due to the braking of the split drive gear 42, the idle gear 44 of the constant speed change mechanism 24 becomes non-rotatable, and the split driven gear 43 and the carrier 51 become non-rotatable.

  The power input to the T / M input shaft 21 is transmitted to the primary shaft 31 of the continuously variable transmission mechanism 23 to rotate the primary shaft 31 and the primary pulley 33. The rotation of the primary pulley 33 is transmitted to the secondary pulley 34 via the belt 35 and rotates the secondary pulley 34 and the secondary shaft 32. As the secondary shaft 32 rotates, the sun gear 52 of the synthesizing gear mechanism 25 rotates. Since the carrier 51 cannot rotate, when the sun gear 52 rotates, the ring gear 53 rotates in the opposite direction to the sun gear 52. The rotation direction of the ring gear 53 is opposite to the rotation direction of the ring gear 53 in the belt mode and the split mode. Then, the T / M output shaft 22 rotates integrally with the ring gear 53. The rotation of the T / M output shaft 22 is transmitted to the ring gear 64 of the differential gear 5 through the output gear 55, the first idle gear 62, the idle shaft 61 and the second idle gear 63. Thereby, the drive shafts 71 and 72 of the vehicle 1 rotate in the reverse direction.

  FIG. 4 is a block diagram showing a main part of the electrical configuration of the vehicle 1.

  The vehicle 1 is equipped with a plurality of ECUs (electronic control units). Each ECU has a configuration including, for example, a CPU and a memory, and is connected so as to be capable of bidirectional communication using a CAN (Controller Area Network) communication protocol. The plurality of ECUs include an ECU 81 for controlling the drive system.

  An ECU 81, an engine speed sensor 83, a turbine speed sensor 83, a vehicle speed sensor 84, and a G sensor 85 are connected to the ECU 81.

  The engine speed sensor 82 inputs a pulse signal synchronized with the rotation of the engine 2 (E / G output shaft 16, torque converter input shaft 11) to the ECU 81. The ECU 81 converts the frequency of the pulse signal input from the engine speed sensor 82 into the engine speed.

  The turbine rotation speed sensor 83 inputs a pulse signal synchronized with the rotation of the turbine runner 14 (torque converter output shaft 12) of the torque converter 3 to the ECU 81. The ECU 81 converts the frequency of the pulse signal input from the turbine speed sensor 83 into the turbine speed.

  The vehicle speed sensor 84 inputs, for example, a pulse signal synchronized with the rotation of the ring gear 64 of the differential gear 5 to the ECU 81. The ECU 81 converts the frequency of the pulse signal input from the vehicle speed sensor 84 into the vehicle speed.

  The G sensor 85 employs a sensor that outputs a signal corresponding to the displacement of the weight as a detection signal corresponding to the acceleration of the vehicle. When the vehicle speed and / or the road surface gradient change, the weight is displaced, and a signal corresponding to the displacement is output from the G sensor 85. The ECU 81 calculates the acceleration of the vehicle from the detection signal of the G sensor 85.

  The engine speed sensor 82, the turbine speed sensor 83, the vehicle speed sensor 84, and the G sensor 85 may be connected to an ECU different from the ECU 81. In that case, the engine speed, turbine speed, vehicle speed, and acceleration may be calculated by the other ECU, and the calculated engine speed, turbine speed, vehicle speed, and acceleration may be input to the ECU 81.

  The ECU 81 is connected with a plurality of solenoid valves 86 for controlling the hydraulic pressure supplied to each part of the torque converter 3 and the power split continuously variable transmission 4 as a control target. The solenoid valve 86 includes, for example, a solenoid valve that controls the hydraulic pressure for engaging / releasing the lockup clutch 15 of the torque converter 3, the high brake HB, the reverse brake RB, and the low clutch of the power split continuously variable transmission 4. A solenoid valve for controlling the hydraulic pressure for LC engagement / release is included.

  The ECU 81 controls the solenoid valve for the lock-up clutch 15 to release the lock-up clutch 15 when the engine speed is higher than the turbine speed. When the engine speed and the turbine speed match, the ECU 81 The up clutch 15 is engaged.

  In addition, the ECU 81 controls the solenoid valve for the high brake HB, the solenoid valve for the reverse brake RB, and the solenoid valve for the low clutch LC in order to switch between the belt mode and the torque mode and to switch between forward / reverse. The engagement / release of the high brake HB, reverse brake RB and low clutch LC is switched. Switching between the belt mode and the split mode is controlled based on, for example, the engine speed and the vehicle speed.

  FIG. 5 is a flowchart showing the flow of split mode prohibition processing.

  While the vehicle 1 is traveling, the ECU 81 repeatedly executes the split mode prohibiting process shown in FIG.

  In the split mode prohibition process, first, it is determined whether or not the power transmission mode of the power split type continuously variable transmission 4 is the belt mode (step S1).

  If the power transmission mode is not the belt mode (NO in step S1), the split mode prohibition process is terminated.

  If the power transmission mode is the belt mode (YES in step S1), it is next determined whether the traveling path of the vehicle 1 is an uphill road, a downhill road, or a flat road (step S2).

  The acceleration acquired from the detection signal of the G sensor 85 includes an acceleration component due to a change in the vehicle speed and an acceleration component due to the gradient of the traveling road. On the other hand, the acceleration obtained by differentiating the vehicle speed acquired from the output signal of the vehicle speed sensor 84 is only the acceleration component due to the change in the vehicle speed. Therefore, by obtaining the difference between the acceleration obtained from the detection signal of the G sensor 85 and the differential value of the vehicle speed, an acceleration component due to the gradient of the traveling road can be obtained. Can be estimated. If the slope value is positive when the slope is an upward slope and the slope value is negative when the slope is a downward slope, for example, if the slope is a positive positive value or more, the traveling road is an uphill road. If the slope is greater than or equal to a certain negative value, it can be determined that the traveling road is a downhill road. Further, if the absolute value of the gradient is less than a certain value, it can be determined that the traveling road is a flat road.

  Next, it is determined whether or not the vehicle 1 is traveling on an uphill intermittent road (step S3). The uphill intermittent road is a traveling road where the uphill road is intermittently repeated by repeating the uphill road and the downhill road or the flat road. For example, when the vehicle 1 approaches an uphill road and it is determined that the traveling road is an uphill road, it may be determined that the vehicle 1 is traveling on an uphill intermittent road. In addition, when the determination of the travel path is repeatedly performed a plurality of times during a predetermined time, and it is intermittently determined that the travel path is an uphill road more than once, the vehicle 1 is traveling on the uphill intermittent road. May be determined.

  When the vehicle 1 is not traveling on the uphill intermittent path (NO in step S3), the split mode prohibition flag is reset to “0” (step S5), and the split mode prohibition process is terminated.

  When the vehicle 1 is traveling on the uphill intermittent road (YES in step S3), “1” is set to the split mode prohibition flag (step S4).

  The split mode prohibition flag is a flag indicating whether switching from the belt mode to the split mode is prohibited. The state in which the split mode prohibition flag is reset (off) to “0” indicates that switching from the belt mode to the split mode is possible, and “1” is set (on) to the split mode prohibition flag. Indicates that switching from the belt mode to the split mode is prohibited. In the state where the split mode prohibition flag is set to “1”, even if the switching condition based on the engine speed and the vehicle speed is satisfied, the switching from the belt mode to the split mode is not performed.

  When the split mode prohibition flag is set to “1”, the travel path is determined again (step S2), and it is determined whether or not the vehicle 1 is still traveling on the uphill intermittent path (step S3). ).

  When it is determined that the vehicle 1 has passed the uphill intermittent road and the vehicle 1 is not traveling on the uphill intermittent road (NO in step S3), the split mode prohibition flag is reset to “0” (step S5). The split mode prohibition process is terminated.

  As described above, the power transmission mode of the power split type continuously variable transmission 4 cannot be switched from the belt mode to the split mode when the vehicle 1 is traveling on the uphill intermittent road. Therefore, if the vehicle 1 is switched from the split mode to the belt mode while traveling on the uphill intermittent route, or if the vehicle 1 reaches the uphill intermittent route while traveling in the belt mode, then the vehicle 1 is subsequently connected to the uphill intermittent route. The belt mode is maintained until exiting. As a result, while the vehicle 1 is traveling on the uphill intermittent road, the vehicle 1 can be accelerated with good response to the driver's accelerator operation, and the driver frequently performs the accelerator operation with a relatively large operation amount. The need to repeat can be eliminated. As a result, it is possible to improve drivability on an uphill intermittent road where the uphill road is intermittent.

  On the other hand, when the vehicle 1 is traveling on a road other than an uphill intermittent road, the power transmission mode is switched from the belt mode to the split mode, so that the traveling fuel consumption of the vehicle 1 can be improved.

  Therefore, it is possible to achieve both improvement in driving fuel consumption and improvement in drivability in the split mode.

  As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, in the determination of the traveling road, an example is described in which the gradient of the traveling road is estimated, and whether the traveling road is an uphill road, a downhill road, or a flat road is determined from the gradient. The operation amount and the vehicle speed may be detected, and it may be determined whether the traveling road is an uphill road, a downhill road, or a flat road from a comparison between a change in the operation amount of the accelerator pedal and a change in the vehicle speed.

  In the split mode prohibition process, the determination (step S1) whether or not the power transmission mode of the power split type continuously variable transmission 4 is the belt mode may be omitted. In this case, when the vehicle 1 reaches the uphill intermittent path while the vehicle 1 is traveling in the split mode, the belt mode is maintained until the vehicle 1 is switched from the split mode to the belt mode and the vehicle 1 exits the uphill intermittent path. May be.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 4 Power split type continuously variable transmission 21 T / M input shaft 23 Continuously variable transmission mechanism 24 Constant transmission mechanism 25 Combining gear mechanism 81 ECU (control device, determination means, prohibition means)

Claims (1)

From a continuously variable transmission mechanism that changes the power input to the input shaft steplessly by changing the transmission ratio, a constant transmission mechanism that shifts the power input to the input shaft at a constant transmission ratio, and the continuously variable transmission mechanism And a combining gear mechanism including a planetary gear mechanism for combining the power of the constant transmission mechanism and the constant transmission mechanism, and the power input to the input shaft is transmitted to the combining gear via the continuously variable transmission mechanism. The continuously variable transmission mode transmitted to the mechanism and the power input to the input shaft are transmitted to the synthesizing gear mechanism via the continuously variable transmission mechanism and the constant transmission mechanism. The power split type continuously variable transmission is applied to a vehicle equipped with a power split type continuously variable transmission configured to be switched to a power split mode for shifting power input to the input shaft with a small speed ratio. Control device to control Te,
Determining means for determining whether or not the vehicle is traveling on an uphill intermittent road where the uphill road is intermittent;
A power split type continuously variable, including prohibiting means for prohibiting switching from the continuously variable transmission mode to the power split mode when the determination means determines that the vehicle is traveling on the uphill intermittent road. Transmission control device.

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