JP6155211B2 - Vehicle drive device and vehicle drive method - Google Patents

Description

  The present invention relates to a vehicle drive device and a vehicle drive method.

  In a hybrid vehicle, when a differential unit having a differential mechanism connected between an engine and a drive wheel and a motor connected to the differential mechanism so as to be able to transmit power can no longer operate normally, A configuration is known that switches to a differential state and changes the gear ratio of the automatic transmission unit to reduce the increase in driving torque generated at the time of switching or the increase in driven torque (see, for example, Patent Document 1). ). With such a configuration, an increase in torque when the differential unit is switched to the non-differential state is reduced, and the driver can be prevented from feeling uncomfortable.

JP 2010-070170 A

For example, a failure of the vehicle includes a state in which a clutch mechanism that transmits engine power is fastened and fixed. In the hybrid vehicle, when the clutch mechanism is in a fixed state, the engine remains connected without being disconnected from the drive wheels even when the engine running by the engine power is switched to the motor running by the motor power.
In this way, when the motor travel is performed with the engine connected to the driving wheel, the rotational speed of the driving unit such as the engine is excessively increased, and an excessive load is applied to the driving unit. There is.

  The present invention has been made in view of such circumstances, and an object of the present invention is to reduce the load on the drive unit when the clutch mechanism is switched to motor running with the clutch mechanism fixed.

According to the first aspect of the present invention, a main power output unit (10, 15) including an internal combustion engine (10), an auxiliary power output unit (55) different from the main power output unit, and an output by the main power output unit. A continuously variable transmission (20) that continuously transmits the transmitted power to the driving wheel side, and a fastening portion (50) that brings the continuously variable transmission and the driving wheel into a fastening state or a releasing state, When the fastening state detecting unit (82) for detecting the state of the fastening part and the fastening state detecting part detect that the fastening of the fastening part is in a fixed state that cannot be released , the rotational speed of the internal combustion engine is A vehicle drive device (1) comprising: a gear ratio control unit (83) that controls the continuously variable transmission so that a gear ratio of the continuously variable transmission becomes equal to or greater than a predetermined value.

  According to a second aspect of the present invention, in the first aspect of the invention, the transmission ratio control unit causes the vehicle to travel with the power output from the auxiliary power output unit, not the power output from the main power output unit. When shifting to the auxiliary power travel mode, when it is detected by the engagement state detection unit that the locked state is detected, the continuously variable transmission is controlled so as to have a gear ratio of a certain value or more.

  According to a third aspect of the present invention, in the second aspect of the present invention, in the state where the gear ratio control unit is controlled so that the gear ratio of the continuously variable transmission is greater than a certain value, the auxiliary power output unit is A torque control unit (84) for controlling the inflow inertia torque acting on the continuously variable transmission according to the output power so as not to exceed the transmission transmittable torque that can be transmitted by the continuously variable transmission. It is.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the torque control unit derives the transmission-transmittable torque based on a state of the continuously variable transmission, and a control state of the auxiliary power output unit. And the vehicle specifications based on the torque of the auxiliary power output unit when the inflow inertia torque is changed so as to substantially match the transmission-transmittable torque. The command motor torque to be applied to the auxiliary power output unit is determined, and control is performed so that the determined command motor torque is applied to the auxiliary power output unit.

  The invention according to claim 5 is the invention according to claim 4, wherein the torque control unit derives a driver request motor torque as a control state of the auxiliary power output unit based on an accelerator opening and a vehicle speed. It is.

  According to a sixth aspect of the present invention, in the fourth or fifth aspect of the invention, the torque control unit determines the command motor torque within a range that is less than or equal to an allowable maximum motor torque allowed to be applied to the auxiliary power output unit. To do.

According to a seventh aspect, in the invention of any one of claims of claims 1 to 6, the continuously variable transmission, in which a toroidal type continuously variable transmission.

According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, the continuously variable transmission is controlled so that a gear ratio of the continuously variable transmission is maximized. .
According to the ninth aspect of the present invention, the main power output unit including the internal combustion engine, the auxiliary power output unit different from the main power output unit, and the power output by the main power output unit are continuously shifted and driven. A control computer for a vehicle drive device, comprising: a continuously variable transmission that transmits to a wheel side; and a fastening part that puts the continuously variable transmission and the drive wheel into a fastening state or a releasing state, detects a state of the fastening part. When the fastening portion is detected to be in a non-releasable fixed state, the vehicle drive is controlled so that the speed ratio of the continuously variable transmission is greater than or equal to a certain value so that the rotational speed of the internal combustion engine is reduced. Is the method.

  According to the first aspect of the present invention, when it is detected that the fastening of the fastening portion is in a non-releasable fixed state, the speed change ratio of the continuously variable transmission is controlled to be a certain level or more, so the fastening portion It is possible to reduce the load on the drive unit when the motor is switched to the motor running in a state where the is fixed.

  According to the second aspect of the present invention, when shifting to the auxiliary power travel mode, when it is detected that the fastening portion is in the fixed state, the transmission ratio of the continuously variable transmission is controlled to be a certain level or more. Therefore, it is possible to reduce the load on the engine by suppressing the rotation of the engine in the auxiliary power travel mode.

  According to the third aspect of the present invention, the inflow inertia torque of the continuously variable transmission does not exceed the transmission-transmittable torque that can be transmitted by the continuously variable transmission when the transmission gear ratio of the continuously variable transmission is greater than a certain value. Thus, the burden on the continuously variable transmission due to the inflow inertia torque can be suppressed.

  According to the fourth aspect of the present invention, the instruction motor to be given to the auxiliary power output unit based on the torque of the auxiliary power output unit when the inflow inertia torque is changed to substantially match the transmission-transmittable torque. Since the torque is determined, it is possible to appropriately control the inflow inertia torque so as not to exceed the transmission possible torque.

  According to the fifth aspect of the present invention, since the driver request motor torque is derived as the control state of the auxiliary power output unit, the inflow inertia torque can be derived appropriately.

  According to the sixth aspect of the present invention, the command motor torque is determined in a range equal to or less than the allowable maximum motor torque allowed to be given to the auxiliary power output unit. The command motor torque can be determined.

It is a figure which shows the structural example of the vehicle drive device 1 which concerns on embodiment. It is sectional drawing which shows an example of a structure of the continuously variable transmission 20 which is a toroidal type continuously variable transmission. 6 is a cross-sectional view showing another example of the configuration of the continuously variable transmission 20. FIG. 6 is a cross-sectional view showing another example of the configuration of the continuously variable transmission 20. FIG. It is a figure which shows an example of the change characteristic of the transmission possible torque according to the gear ratio of the continuously variable transmission 20, and a hydraulic pressure. It is a figure which shows the example of a transition of the driving modes in the vehicle drive device. It is a flowchart which shows an example of the flow of the process which hybrid ECU80 performs in order to transfer to engine driving mode from engine driving mode. 4 is a flowchart showing an example of a flow of instruction motor torque determination processing executed by a hybrid ECU 80. It is a figure for demonstrating the parameter used in the process of FIG.

  Hereinafter, embodiments of a vehicle drive device and a vehicle drive method of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration example of a vehicle drive device 1 according to the embodiment. The vehicle drive device 1 includes, for example, an engine 10, a first motor 15, a continuously variable transmission 20, an oil pump 45, a hydraulic sensor 47, a clutch mechanism 50, a second motor 55, a battery 60, A wheel (drive wheel) 70, a hybrid ECU (Electronic Control Unit) 80, and a transmission ECU 90 are provided.

The engine 10 burns hydrocarbon-based fuel such as gasoline, and thereby outputs driving power for a vehicle on which the vehicle drive device 1 is mounted.
The first motor 15 has a function in which an output shaft is connected to a crankshaft that is an output shaft of the engine 10, a function of starting the engine 10 to raise it to a desired rotational speed, and a function of generating electric power using the power output from the engine 10. Have.

The continuously variable transmission 20 continuously shifts the power output from the engine 10 and transmits it to the wheel (drive wheel) 70 side. The continuously variable transmission 20 of the present embodiment is, for example, a toroidal continuously variable transmission.
FIG. 2 is a cross-sectional view showing an example of the configuration of a continuously variable transmission 20 that is a toroidal type continuously variable transmission. The continuously variable transmission 20 includes a pair of input-side disks 22a and 22b around a portion near both ends of the input rotation shaft 21, and the input rotation shaft 21 in a state where inner surfaces each of which is a toroidal curved surface face each other. Supports the rotation synchronized with.
The continuously variable transmission 20 supports an output cylinder 23 around the intermediate portion of the input rotary shaft 21 so as to be rotatable with respect to the input rotary shaft 21. Further, the continuously variable transmission 20 has an output gear 24 fixed at the center in the axial direction on the outer peripheral surface of the output cylinder 23, and a pair of output side disks 25a and 25b are spline-engaged at both ends in the axial direction. Thus, the rotation synchronized with the output cylinder 23 is supported.
The inner side surfaces of the output side disks 25a and 25b are toroidal curved surfaces, which are opposed to the inner side surfaces of the input side disks 22a and 22b, respectively.

Further, the continuously variable transmission 20 includes a plurality of powers each having a spherical convex surface between the input side disk 22a and the output side disk 25a and between the input side disk 22b and the output side disk 25b. The roller 26 is sandwiched.
Each power roller 26 is rotatably supported by a trunnion 27, and rotates with the rotation of the input side disks 22a and 22b, and power is supplied from the input side disks 22a and 22b to the output side disks 25a and 25b. introduce. That is, during operation of the continuously variable transmission 20, the input side disk 22 a (left side in FIG. 2) is rotated by the drive shaft 28 via the pressing device 29.
As a result, the pair of input-side disks 22a and 22b supported at both ends of the input rotating shaft 21 rotate synchronously while being pressed toward each other. Then, this rotation is transmitted to the output side disks 25 a and 25 b through the respective power rollers 26 and is taken out from the output gear 24.

Further, the continuously variable transmission 20 is provided with preload springs 30a and 30b at positions where the input side disks 22a and 22b are sandwiched from both axial sides in the vicinity of both ends of the input rotary shaft 21, respectively. Even when the pressing device 29 is not operated (when the drive shaft 28 is stopped), the rolling contact portion between the peripheral surface of each power roller 26 and the inner surfaces of the input side disks 22a and 22b and the output side disks 25a and 25b. The surface pressure of (traction part) is ensured only to the minimum necessary. Therefore, these rolling contact portions start power transmission without causing excessive slip immediately after the start of operation of the continuously variable transmission 20.
In addition, the elasticity for ensuring the necessary minimum surface pressure is obtained by the preload spring 30 a disposed on the inner diameter side of the pressing device 29. The elasticity of the preload spring 30a can be adjusted by the tightening amount of the loading nut 31 screwed to the tip end portion of the input rotary shaft 21.
The preload spring 30b disposed between the loading nut 31 screwed to the tip end portion of the input rotating shaft 21 and the outer surface of the input side disk 22b reduces the impact applied when the pressing device 29 is suddenly operated. It can be omitted. In the case where the preload spring 30b is provided, it is preferable to provide a sufficiently large elasticity (so as not to be completely crushed even when a large torque is transmitted).

The continuously variable transmission 20 may have the configuration shown in FIG. FIG. 3 is a cross-sectional view showing another example of the configuration of the continuously variable transmission 20 (hereinafter referred to as a continuously variable transmission 20a).
In the continuously variable transmission 20a, a locking groove 32 is formed on the outer peripheral surface of the tip end portion of the input rotary shaft 21a over the entire circumference, and a locking ring 33 is locked in the locking groove 32. In the continuously variable transmission 20a, the inner surface (the left side surface in FIG. 3) of the locking ring 33 is brought into contact with the outer surface of the input side disk 22b. When the hydraulic pressing device 29a is not in operation, the minimum necessary surface pressure of the rolling contact portion between the peripheral surface of each power roller 26 and the inner surfaces of the input side disks 22a and 22b and the output side disks 25a and 25b is secured. For this purpose, adjustment of the elasticity of the disc spring 30a can be achieved by selecting a locking ring 33 having an appropriate axial thickness dimension.
In the continuously variable transmission 20a, the retaining ring 34 provided at the tip of the input rotary shaft 21a prevents the locking ring 33 from coming out of the locking groove 32. The locking ring 33 includes an annular portion 35 and a cylindrical portion 36, and the annular portion 35 is externally fitted to the distal end portion of the input rotation shaft 21 a, and the inner peripheral surface of the cylindrical portion 36 is connected to the locking ring 33. It is in contact with or close to the outer peripheral surface. Such a locking ring 33 is prevented from being displaced in the axial direction by a retaining ring 37 that is locked to the tip of the input rotary shaft 21a.

The continuously variable transmission 20 may have the configuration shown in FIG. FIG. 4 is a cross-sectional view showing another example of the configuration of the continuously variable transmission 20 (hereinafter referred to as a continuously variable transmission 20b).
In the continuously variable transmission 20b, the locking ring 33a is formed into an annular shape by combining a plurality of elements each having a partial arc shape. The locking ring 33a includes a locking portion 40 that is locked to a locking groove 32 formed on the outer peripheral surface of the distal end portion of the input rotation shaft 21b in a state where these elements are combined, and an axial direction of the locking portion 40 And a fitting tube portion 41 formed in a state protruding in the axial direction from the end surface (the right side surface in FIG. 4). When the locking ring 33a is assembled to the toroidal-type continuously variable transmission, the locking portion 40 is locked in the locking groove 32 while displacing each element radially inward. The inner side surface of 40 (the left side surface in FIG. 4) is brought into contact with the outer side surface of the input side disk 22b. In the above state, the inner peripheral surface of the fitting cylinder portion 41 abuts or is close to the apex of each spline tooth constituting the male spline formed on the outer peripheral surface of the tip end portion of the input rotation shaft 21b.
The inner peripheral surface of the fitting tube portion 41 may be a simple cylindrical surface, but may be a female spline that is spline-engaged with the male spline. In any case, the fitting cylinder portion 41 fitted on the tip end portion of the input rotating shaft 21b is strongly suppressed by the single cylindrical holding ring 42 (the fitting cylinder portion 41 is provided on the inner diameter side of the holding ring 42). Press fit). Thereby, each element is prevented from being displaced radially outward, the fitting cylinder portion 41 is fitted and fixed to the tip end portion of the input rotation shaft 21b, and the locking ring 33a is supported by the input rotation shaft 21b. Fix it.
In the continuously variable transmission 20b, when the pressing device 29 (see FIGS. 2 to 3) is not operated, the peripheral surface of each power roller 26 (see FIG. 2), the input side disks 22a and 22b, and the output side disk 25a, The adjustment of the elasticity of the disc spring 30a (see FIG. 3) in order to ensure the necessary minimum surface pressure of the rolling contact portion with the inner surface of 25b, the thickness of the locking portion 40 is appropriate as the locking ring 33a. This can be achieved by selecting an appropriate item.

  In the continuously variable transmission 20b, the locking ring 33a is supported and fixed to the tip of the input rotary shaft 21b, and the portion between the inner peripheral surface of the locking portion 40 and the bottom surface of the locking groove 32 is provided. A radial gap 43 is provided. Further, in the continuously variable transmission 20b, the outer peripheral surface of the restraining ring 42 is an inner ring raceway of a radial needle bearing for rotatably supporting the input rotary shaft 21b in the casing.

  The oil pump 45 supplies oil (lubricating oil) to the continuously variable transmission 20 (or 20a, 20b; hereinafter the same) having the structure illustrated in FIGS. The oil pump 45 is connected to, for example, a crankshaft that is an output shaft of the engine 10, and sends oil into the continuously variable transmission 20 in conjunction with the rotation of the crankshaft. The oil pressure sensor 47 measures the oil pressure of the oil sent from the oil pump 45 to the continuously variable transmission 20 and outputs it to the hybrid ECU 80.

  The clutch mechanism 50 switches the output shaft of the continuously variable transmission and the wheel 70 so as to rotate in an interlocked state (fastened state) or in a disconnected state (released state). The state of the clutch mechanism 50 is controlled by the hybrid ECU 80, for example.

  The second motor 55 outputs a driving force for traveling to the axle connected to the wheel 70 or generates (regenerates) power using the power input from the axle. The electric power consumed or generated by the first motor 15 and the second motor 55 is supplied or stored from the battery 60.

  The hybrid ECU 80 has, for example, a configuration in which a storage unit 85 that stores various information including a program executed by a processor such as a CPU (Central Processing Unit), a communication interface, and the like are connected via a bus. As the storage unit 85, a ROM (Read Only Memory), a RAM (Random Access Memory), a flash memory, an HDD (Hard Disk Drive), or the like is used.

  The hybrid ECU 80 includes, for example, a travel mode control unit 81, a fastening state detection unit 82, a transmission ratio control unit 83, and a torque control unit 84 as functional units that function when the processor executes a program. Some or all of these functions may be hardware function units such as LSI (Large Scale Integration) and ASIC (Application Specific Integrated Circuit). The hybrid ECU 80 also includes a storage unit 85.

The travel mode control unit 81 switches the travel mode. In the present embodiment, the travel mode is first divided into an engine travel mode (main power travel mode) and a motor travel mode (auxiliary power travel mode).
The engine travel mode is a travel mode in which the vehicle travels with power including power output from the engine 10. The engine travel mode is further divided into a single engine travel mode and a combined engine travel mode.
The single engine travel mode is an engine travel mode in which the vehicle travels by power from only the engine 10 and the first motor 15. The combined engine travel mode is an engine travel mode in which the vehicle travels with power output from both the engine 10, the first motor 15, and the second motor 55.

  The motor travel mode is a mode in which the vehicle travels with the power output from the second motor 55 without depending on the power output from the engine 10.

The engaged state detection unit 82 detects the state of the clutch mechanism 50. That is, the engagement state detection unit 82 can detect whether the clutch mechanism 50 is in the engagement state or the release state.
In addition, the engagement state detection unit 82 can detect that the clutch mechanism 50 is in a fixed state that cannot be released while the clutch mechanism 50 is engaged. The fixed state in which the clutch mechanism 50 remains engaged and cannot be released is one of the states in which the clutch mechanism 50 has failed. Hereinafter, such a failure state is also referred to as a clutch stick. That is, the engagement state detection unit 82 of the present embodiment can detect the engagement state and the release state of the clutch in the normal state, and can also detect the occurrence of a failure due to the clutch stick.

For example, the engagement state detection unit 82 can detect the occurrence of a clutch stick as follows. That is, the engagement state detection unit 82 starts detecting the clutch pressure in the clutch mechanism 50 in response to a release request for releasing the engagement state of the clutch mechanism 50. The clutch pressure is a pressure corresponding to the pressing force of the clutch mechanism 50.
For example, when a clutch release request is issued, it is instructed that the clutch pressure should be zero. For example, when the clutch mechanism 50 is a hydraulic type, the engagement state detection unit 82 can detect the clutch pressure based on the measured value of the hydraulic pressure.
The engaged state detection unit 82 compares the detected clutch pressure with a predetermined clutch pressure threshold value. The engaged state detection unit 82 determines that a clutch stick has occurred when a state where the clutch pressure is higher than the clutch pressure threshold value continues for a predetermined time period or longer.

The gear ratio control unit 83 controls the gear ratio of the continuously variable transmission 20. In addition, the gear ratio control unit 83 determines that the gear ratio of the continuously variable transmission 20 is greater than or equal to a certain level when the engagement state detection unit 82 detects that the clutch stick is in the state of transition to the motor travel mode. Control to be.
For example, if the gear ratio is small when the engine travel mode is switched from the engine travel mode to the motor travel mode under the state where the clutch stick is generated, the engine 10 is excessive in response to the rotation of the second motor 55. There is a possibility of rotating at a high speed. If the engine 10 rotates at an excessively high speed as described above, an excessive load is applied to the engine 10.

Therefore, the gear ratio control unit 83 of the present embodiment sets the gear ratio of the continuously variable transmission 20 to a certain level or more when it is detected that the clutch stick is in the state when shifting to the motor travel mode.
When the gear ratio is greater than or equal to a certain value, the rotational speed of the engine 10 is reduced with respect to the rotational speed of the second motor 55, and the burden on the engine 10 is reduced. Moreover, vibration noise (NV) is also suppressed by reducing the rotation speed of the engine 10.
In the following, a case where the speed ratio is maximized will be described as an example of a speed ratio of a certain level or more.

  The torque control unit 84 is configured so that the inflow inertia torque of the continuously variable transmission 20 exceeds the transmission possible torque when the transmission ratio control unit 83 is controlled to maximize the transmission ratio of the continuously variable transmission 20. Control to not.

The transmission-transmittable torque is torque that can be transmitted from the wheel 70 (driving wheel) side to the engine 10 side in the continuously variable transmission 20.
FIG. 5 shows an example of a change characteristic of the transmission possible torque according to the transmission ratio of the continuously variable transmission 20 and the hydraulic pressure. In the figure, the vertical axis represents the transmission-transmittable torque, and the horizontal axis represents the transmission ratio.
A curve CV1 shown in the figure indicates a transmission-transmittable torque corresponding to a transmission ratio under a condition where the hydraulic pressure of the continuously variable transmission 20 is the lowest. A curve CV2 represents a transmission-transmittable torque according to a gear ratio under a condition where the hydraulic pressure of the continuously variable transmission 20 is the highest. The transmission-transmittable torque changes in a range between the curve CV1 and the curve CV2 according to the oil pressure, as exemplified by the arrow A, under the same gear ratio.

When the clutch stick is generated, the clutch mechanism 50 is not released even under the motor travel mode, so the engine 10 is in a state of rotating with the rotation of the second motor 55.
Therefore, an inertia torque is generated in the engine 10 according to the inertia (inertia moment) and the rate of change of the rotational speed. In addition, the first motor 15 other than the engine 10, the wheels 70, the clutch mechanism 50, the continuously variable transmission 20, and the like generate inertia torques corresponding to the respective inertia and the rate of change of the rotational speed.
Then, the inertia torque of each of the components (the first motor 15, the engine 10, the wheel 70, the clutch mechanism 50, the continuously variable transmission 20 itself) flows into the continuously variable transmission 20. Thus, the total amount of inertia torque flowing into the continuously variable transmission 20 from each component is the inflow inertia torque. That is, the inflow inertia torque is a torque that acts on the continuously variable transmission 20 according to the power output from the second motor 55.

As described above, when the motor travel mode is in the clutch stick state, the gear ratio control unit 83 controls the continuously variable transmission 20 so that the gear ratio becomes maximum. Point P in FIG. 4 shows an example of transmission-transmittable torque according to the hydraulic pressure when the transmission ratio of continuously variable transmission 20 is controlled to the maximum as described above.
At this time, in a state where the rotation speed of the component is large, there is a possibility that the inflow inertia torque of the continuously variable transmission 20 becomes large and exceeds the transmission possible torque. Thus, when the inflow inertia torque becomes larger than the transmission-transmittable torque, an excessive amount of the inflow inertia torque with respect to the transmission-transmittable torque places an excessive burden on the continuously variable transmission 20.

Therefore, the torque control unit 84 of the present embodiment performs control so that the inflow inertia torque does not exceed the transmission possible torque. Thereby, an excessive load applied to the continuously variable transmission 20 can be reduced, and the continuously variable transmission 20 can be protected.
In controlling the inflow inertia torque as described above, the torque control unit 84 derives transmission-transmittable torque based on the state of the continuously variable transmission 20 (for example, the gear ratio and hydraulic pressure described in FIG. 5). .
Further, as described above, the torque control unit 84 derives the inflow inertia torque based on the control state of the second motor 55 and the vehicle specifications.
More specifically, the torque control unit 84 determines the driver requested motor torque based on the accelerator opening detected by the accelerator opening sensor 86 and the vehicle speed detected by the vehicle speed sensor 87 as the control state of the second motor 55. Is derived. The driver request motor torque is a control value for the motor torque of the second motor 55 obtained in accordance with the accelerator opening degree at the current speed.
In addition, the torque control unit 84 calculates the inertia torque of each component in the vehicle drive device 1 in order to calculate the inflow inertia torque. The torque control unit 84 calculates the inertia torque of each component based on the inertia (vehicle specification) of each component and the rotation speed change rate corresponding to the driver request motor torque. The torque control unit 84 can calculate the inflow inertia torque by integrating the inertia torque for each component calculated as described above.

  Then, the torque control unit 84 provides the instruction motor torque to be given to the second motor 55 based on the torque of the second motor 55 when the inflow inertia torque is changed to match the transmission possible torque. decide. Then, the torque control unit 84 performs control so that the instruction motor torque determined as described above is applied to the second motor 55.

As can be understood from the above description, the designated motor torque determined as described above is applied to the second motor 55 under a state in which the gear ratio of the continuously variable transmission 20 is controlled to be maximum. Control is performed to give.
By controlling the torque of the second motor 55 in this manner, the inflow inertia torque flowing into the continuously variable transmission 20 is limited so as not to exceed the transmission possible torque. As a result, the burden on the continuously variable transmission 20 is reduced, and the continuously variable transmission 20 is protected.

Next, a travel mode transition example of the vehicle drive device 1 in the present embodiment will be described with reference to FIG.
In the motor travel mode MD1, the hybrid ECU 80 executes control corresponding to motor travel (step S10). In the motor travel mode MD1, the engine is controlled so as to be stopped.
In transition from the motor travel mode MD1 to the engine travel mode, an engine start request is generated in the hybrid ECU 80. In response to the engine start request, the hybrid ECU 80 transitions to the engine travel transition mode MD2. The engine travel transition mode MD2 is a mode in which a preparation operation for transitioning to the engine travel mode is performed.

In the engine travel transition mode MD2, the hybrid ECU 80 increases the rotational speed of the engine 10 (step S20). Further, the hybrid ECU 80 controls the continuously variable transmission 20 so as to achieve a gear ratio according to conditions such as the current speed, for example (step S22).
In the motor travel mode MD1, the clutch mechanism 50 is in a released state. Therefore, the hybrid ECU 80 fastens the clutch mechanism 50 (step S24).
Then, the hybrid ECU 80 executes torque replacement control so that the torque applied to the wheels 70 is switched from the second motor 55 side to the engine 10 side (step S26).
When the processing as the engine travel transition mode MD2 is completed in this way, the transition to the engine travel mode MD3 is performed.

  In the engine travel mode MD3, the hybrid ECU 80 executes control corresponding to engine travel (step S30).

  When shifting from the engine travel mode to the motor travel mode, the hybrid ECU 80 outputs a motor travel request. In response to the motor travel request, the hybrid ECU 80 transitions to the motor travel transition mode MD4. The motor travel transition mode MD4 is a mode in which a preparation operation for transitioning to the motor travel mode is performed.

In the motor travel transition mode MD4, the hybrid ECU 80 executes control to release the clutch mechanism 50 that has been engaged so far (step S40).
Next, the hybrid ECU 80 determines whether or not a clutch stick is generated from the state of the clutch mechanism 50 according to the control in step S40 (step S42). If the clutch stick is not generated, the hybrid ECU 80 stops the engine 10 (step S44).
When the processing as the motor travel mode MD4 is completed in this way, the transition to the motor travel mode MD1 is performed.

When the clutch stick has occurred, the hybrid ECU 80 shifts to the clutch stick-compatible motor travel mode MD5.
In the clutch stick compatible motor travel mode MD5, the hybrid ECU 80 executes control for the clutch stick compatible motor travel (step S50).
In addition, when shifting from the clutch stick-compatible motor travel mode MD5 to the engine travel mode MD3, the hybrid ECU 80 generates an engine start request.
In response to the engine start request, the hybrid ECU 80 transitions to the engine travel mode MD3. That is, in the clutch stick-compatible motor travel mode MD5, the clutch mechanism 50 remains engaged. Therefore, in this case, it is only necessary to make a transition to the engine travel mode MD3 without going through the engine travel transition mode MD2 including the engagement control of the clutch mechanism 50.

FIG. 7 is a flowchart illustrating an example of a flow of processing executed by the hybrid ECU 80 in order to shift from the engine travel mode to the motor travel mode.
First, the traveling mode control unit 81 of the hybrid ECU 80 determines whether or not an engine stop request has been generated (step S100). The engine stop request corresponds to the motor travel request described in FIG.
If it is determined that an engine stop request has not occurred, the processing shown in FIG. That is, in this case, the conventional engine running mode is maintained.

  On the other hand, when the engine stop request is generated, the traveling mode control unit 81 generates a clutch release request (step S102). In response to the clutch release request, the clutch mechanism 50 is controlled so that the engaged state so far is released. The clutch release control in step S40 in FIG. 6 corresponds to step S102.

After the clutch release request, the engaged state detection unit 82 determines whether or not a clutch stick is generated (step S104). The determination on the clutch stick in step S42 in FIG. 6 corresponds to step S104.
As described above, the engagement state detection unit 82 detects that the clutch stick is generated when the state where the clutch pressure is higher than the clutch pressure threshold value continues for a predetermined time or more. On the other hand, if the state where the clutch pressure is lower than the clutch pressure threshold is maintained above a certain level, the engagement state detection unit 82 determines that no clutch stick is generated.

  When the clutch stick is not generated, the hybrid ECU 80 executes a process for shifting to the normal motor travel mode as follows. The normal motor travel mode here corresponds to the motor travel mode MD1 of FIG.

First, the travel mode control unit 81 executes torque replacement control from engine travel to motor travel (step S106). That is, the traveling mode control unit 81 switches from a state in which the wheels 70 are driven by the power output from the engine 10 to a state driven by the power output from the second motor 55.
Next, the gear ratio control unit 83 outputs a gear ratio change request stepwise until the gear ratio of the continuously variable transmission 20 reaches the gear ratio according to the stop of the engine 10 (step S108). At this time, the travel mode control unit 81 determines whether or not the change up to the gear ratio according to the stop of the engine 10 has been completed each time the change request to the gear ratio is output stepwise (step S110). .

When the change to the gear ratio according to the stop of the engine 10 is completed as described above, the torque control unit 84 attenuates the torque of the first motor 15 until it is determined that the engine 10 has stopped (step S114). The request is repeatedly executed (step S112). The processing from step S108 to S114 corresponds to the engine stop control in step S44 of FIG.
And if it determines with the engine 10 having stopped, it will be in the state by which driving | running | working by normal motor driving mode is performed after that.

On the other hand, when it is determined in step S104 that a clutch stick has occurred, the hybrid ECU 80 executes a process for making a transition to a motor travel mode corresponding to the clutch stick as follows.
First, the gear ratio control unit 83 generates a gear ratio request for maximizing the gear ratio of the continuously variable transmission 20 (step S116), and performs control so that the gear ratio of the continuously variable transmission 20 is maximized. To do.
Next, the travel mode control unit 81 executes torque replacement control from engine travel to motor travel (step S118).
Next, the torque control unit 84 executes a process (instruction motor torque determination process) for determining a torque (instruction motor torque) to be applied to the second motor 55 (step S120).

  FIG. 8 is a flowchart showing an example of the flow of instruction motor torque determination processing as step S120 of FIG. The parameters shown in FIG. 9 are used in the instruction motor torque determination process in FIG.

  The parameters shown in FIG. 9 are the transmission-transmittable torque Ttm, the transmission ratio Ract, the transmission hydraulic pressure Poil, the inflow inertia torque Tiner, the component inertia Icomp (i), the component rotational speed change rate dNcomp (i), and the driver request motor torque. Tmot_drv, corrected motor torque Tmot_mod, instruction motor torque Tmot, and allowable maximum motor torque Tmot_max.

The transmission-transmittable torque Ttm is a torque that can be transmitted from the wheel 70 (drive wheel) side to the engine 10 side in the continuously variable transmission 20 as described above.
The speed ratio Ract is the speed ratio of the continuously variable transmission 20.
The transmission hydraulic pressure Poil is a hydraulic pressure applied to the continuously variable transmission 20.
As described above, the inflow inertia torque is the total amount of inertia torque that flows from each component (first motor 15, engine 10, wheel 70, clutch mechanism 50, continuously variable transmission 20 itself) into the continuously variable transmission 20. is there.
Component inertia Icomp (i) is the inertia of the i-th component among the plurality of components.
The component rotational speed change rate dNcomp (i) is the rotational speed change rate of the i-th component among the plurality of components.
As described above, the driver request motor torque Tmot_drv is the torque of the second motor 55 obtained according to the accelerator opening degree under the current speed.
The corrected motor torque Tmot_mod is the torque of the second motor 55 when the inflow inertia torque is changed to match the transmission possible torque.
The instruction motor torque Tmot is a torque to be applied to the second motor 55.
The allowable maximum motor torque Tmot_max is a maximum value of torque that is allowed to be applied to the second motor 55. The allowable maximum motor torque Tmot_max is determined in advance based on the specifications of the second motor 55 and the like.

  In FIG. 8, first, the torque control unit 84 calculates (derived) the driver request motor torque Tmot_drv (step S200). As described above, the torque control unit 84 uses the accelerator opening detected by the accelerator opening sensor 86 and the vehicle speed detected by the vehicle speed sensor 87 in calculating the driver request motor torque Tmot_drv.

Further, the torque control unit 84 calculates a transmission-transmittable torque Ttm (step S202). As described with reference to FIG. 5, the transmission-transmittable torque Ttm is uniquely obtained based on the state (speed ratio and hydraulic pressure) of the continuously variable transmission 20.
That is, the torque control unit 84 can obtain the transmission-transmittable torque Ttm from the function f ₁ using the transmission ratio Ract and the transmission hydraulic pressure Poil as parameters, as shown in the following Expression 1.
Ttm ← f ₁ (Ract, Poil) Equation 1

Further, the torque controller 84 calculates an inflow inertia torque Tiner (step S204). The torque control unit 84 obtains the inflow inertia torque Tiner from the function f ₂ using the component inertia Icomp (i) and the component rotational speed change rate dNcomp (i) as parameters as shown in the following Expression 2. it can.
Tiner = f ₂ (Icomp (i), dNcomp (i)) Equation 2

  Depending on the component inertia Icomp (i) and the component rotational speed change rate dNcomp (i), the inertia torque of the i-th component can be obtained. The function f2 is a function for obtaining the inflow inertia torque Tiner by integrating the inertia torque of each component.

  Next, the torque control unit 84 changes the inflow inertia torque Tiner so as to match the transmission-transmittable torque Ttm, and obtains the torque of the second motor 55 at this time as the corrected motor torque Tmot_mod (step S206).

  The inflow inertia torque Tiner changes according to the component rotational speed change rate dNcomp (i) as understood from the equation (2). Therefore, the torque control unit 84 changes the component rotation speed change rate dNcomp (i) to change the inflow inertia torque Tiner to coincide with the transmission-transmittable torque Ttm. The torque controller 84 obtains the torque of the second motor 55 corresponding to the component rotational speed change rate dNcomp (i) when the inflow inertia torque Tiner coincides with the transmission transferable torque Ttm as the corrected motor torque Tmot_mod.

It should be noted that in deriving the corrected motor torque Tmot_mod as described above, the torque of the second motor 55 corresponding to the component rotational speed change rate dNcomp (i) is obtained.
For this purpose, for example, the storage unit 85 in the hybrid ECU 80 may store a table showing the correspondence between the torque of the second motor 55 and the component rotational speed change rate for each component.
In step S206, the torque control unit 84 refers to the table every time the driver request motor torque Tmot_drv is changed (corrected). The torque control unit 84 may acquire a torque value associated with the component rotational speed change rate dNcomp (i) when the inflow inertia torque Tiner matches the transmission transferable torque Ttm from the table.
Alternatively, the torque control unit 84 may obtain the component rotation speed change rate for each component from the driver request motor torque Tmot_drv by calculation using a predetermined function.
For example, the torque control unit 84 treats the state where the inflow inertia torque Tiner falls within a certain range based on the transmission-transmittable torque Ttm, as if the inflow inertia torque Tiner matches the transmission-transmittable torque Ttm. May be.

  Next, the torque control unit 84 determines whether or not the corrected motor torque Tmot_mod derived in step S206 is smaller than the driver request motor torque Tmot_drv calculated in step S200 (step S208).

  When the corrected motor torque Tmot_mod is smaller than the driver request motor torque Tmot_drv, the corrected motor torque Tmot_mod may be given as it is. Therefore, the torque control unit 84 in this case substitutes the value of the corrected motor torque Tmot_mod derived in step S206 for the instruction motor torque Tmot as the first instruction motor torque determination process (step S210).

On the other hand, when the corrected motor torque Tmot_mod is equal to or greater than the driver request motor torque Tmot_drv, the torque control unit 84 sets the driver request motor torque calculated in step S200 to the instruction motor torque Tmot as the first instruction motor torque determination process. Tmot_drv is substituted (step S212).
For example, when the control is actually performed with the corrected motor torque Tmot_mod larger than the driver request motor torque Tmot_drv as the instruction motor torque Tmot as it is, the vehicle speed becomes higher than the speed that should be obtained according to the driver's accelerator operation. Will change.
Therefore, in the present embodiment, the value of the driver request motor torque Tmot_drv is applied as the instruction motor torque Tmot in step S212 described above. By doing so, the instruction motor torque Tmot does not exceed the driver request motor torque Tmot_drv, and the above-described problems are avoided.

After executing the primary instruction motor torque determination process in step S210 or step S212, the torque control unit 84 executes the secondary instruction motor torque determination process (step S214).
As the second instruction motor torque determination process, the torque control unit 84 determines the smaller one of the instruction motor torque Tmot and the allowable maximum motor torque Tmot_max determined in step S210 or step S212 as the instruction motor torque Tmot. To do.
Thus, the torque control unit 84 determines the command motor torque within a range that is equal to or less than the allowable maximum motor torque Tmot_max. Thus, the instruction motor torque Tmot is appropriately limited so as not to exceed the allowable maximum motor torque Tmot_max.

  Returning to FIG. After the command motor torque determination process in step S120 described with reference to FIG. 8, the torque control unit 84 performs control so that the command motor torque Tmot determined in step S120 is applied to the second motor 55 (step S122). ).

In addition, the travel mode control unit 81 performs control for reducing the torque of the first motor 15 to 0 and control for stopping fuel supply to the engine 10. At this time, the state in which the speed ratio of the continuously variable transmission 20 controlled according to step S116 is maximum is maintained thereafter (step S124).
As described above, when the control in step S124 is executed, the engine 10 is rotated at a sufficiently low speed with almost no torque in accordance with the driving of the wheel 70 by the power from the second motor 55. The state to do is obtained. As described above, in the present embodiment, the engine 10 is protected in a state where the motor travel is switched under the state of the clutch stick.

  The above-described hybrid ECU 80 is configured by recording a program for realizing the functions of the above-described hybrid ECU 80 on a computer-readable recording medium, causing the computer system to read and execute the program recorded on the recording medium. You may perform the process of. Here, “loading and executing a program recorded on a recording medium into a computer system” includes installing the program in the computer system. The “computer system” here includes an OS and hardware such as peripheral devices. Further, the “computer system” may include a plurality of computer devices connected via a network including a communication line such as the Internet, WAN, LAN, and dedicated line. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. As described above, the recording medium storing the program may be a non-transitory recording medium such as a CD-ROM. The recording medium also includes a recording medium provided inside or outside that is accessible from the distribution server in order to distribute the program. The code of the program stored in the recording medium of the distribution server may be different from the code of the program that can be executed by the terminal device. That is, the format stored in the distribution server is not limited as long as it can be downloaded from the distribution server and installed in a form that can be executed by the terminal device. Note that the program may be divided into a plurality of parts, downloaded at different timings, and combined in the terminal device, or the distribution server that distributes each of the divided programs may be different. Furthermore, the “computer-readable recording medium” holds a program for a certain period of time, such as a volatile memory (RAM) inside a computer system that becomes a server or a client when the program is transmitted via a network. Including things. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  As mentioned above, although the form for implementing this invention was demonstrated using embodiment, this invention is not limited to such embodiment at all, and various deformation | transformation and substitution are within the range which does not deviate from the summary of this invention. Can be added.

DESCRIPTION OF SYMBOLS 1 ... Vehicle drive device 10 ... Engine (internal combustion engine, main power output part)
15 ... 1st motor (main power output part)
20 ... Continuously variable transmission 45 ... Oil pump 47 ... Hydraulic pressure sensor 50 ... Clutch mechanism (fastening part)
55. Second motor (auxiliary power output unit)
60 ... Battery 70 ... Wheel 81 ... Traveling mode control unit 82 ... Engagement state detection unit 83 ... Gear ratio control unit 84 ... Torque control unit 85 ... Storage unit 86 ... Accelerator opening sensor 87 ... Vehicle speed sensor

Claims (9)

A main power output unit including an internal combustion engine;
An auxiliary power output unit different from the main power output unit;
A continuously variable transmission that continuously shifts the power output by the main power output unit and transmits the power to the drive wheels;
A fastening portion for fastening the continuously variable transmission and the drive wheel to a fastening state or a releasing state;
A fastening state detection unit for detecting a state of the fastening unit;
When the fastening state detection unit detects that the fastening portion is in a non-releasable fixed state, the transmission ratio of the continuously variable transmission is greater than or equal to a certain value so that the rotational speed of the internal combustion engine is reduced. A transmission ratio control unit for controlling
A vehicle drive device comprising: The transmission ratio control unit
When the state is shifted to the auxiliary power traveling mode in which the vehicle is driven by the power output from the auxiliary power output unit regardless of the power output from the main power output unit, the fastening state detection unit is in the fixed state. The vehicle drive device according to claim 1, wherein, when detected, control is performed so that a gear ratio of the continuously variable transmission becomes a certain level or more. Inflow inertia that acts on the continuously variable transmission according to the power output by the auxiliary power output unit in a state where the gear ratio of the continuously variable transmission is controlled to be a certain level or more by the speed ratio control unit. The vehicle drive device according to claim 2, further comprising a torque control unit that controls the torque so as not to exceed a transmission-transmittable torque that can be transmitted by the continuously variable transmission. The torque control unit
Deriving the transmission-transmittable torque based on the state of the continuously variable transmission,
Deriving the inflow inertia torque based on the control state of the auxiliary power output unit and the specifications of the vehicle,
Determining an instruction motor torque to be applied to the auxiliary power output unit based on the torque of the auxiliary power output unit when the inflow inertia torque is changed to substantially match the transmission-transmittable torque;
The vehicle drive device according to claim 3, wherein control is performed such that the determined instruction motor torque is applied to the auxiliary power output unit. The torque control unit
The vehicle drive device according to claim 4, wherein a driver request motor torque as a control state of the auxiliary power output unit is derived based on an accelerator opening and a vehicle speed. The torque control unit
The vehicle drive apparatus according to claim 4 or 5, wherein the command motor torque is determined in a range equal to or less than an allowable maximum motor torque allowed to be applied to the auxiliary power output unit. The continuously variable transmission is a toroidal type continuously variable transmission,
The vehicle drive device according to any one of claims 1 to 6. The transmission ratio control unit
  Control so that the gear ratio of the continuously variable transmission is maximized.
  The vehicle drive device according to any one of claims 1 to 7. A main power output unit including an internal combustion engine, an auxiliary power output unit different from the main power output unit, and a continuously variable transmission that continuously shifts the power output by the main power output unit and transmits it to the drive wheel side. A control computer for a vehicle drive device comprising: a machine, and a fastening portion that puts the continuously variable transmission and the drive wheel into a fastened state or a released state;
Detecting the state of the fastening portion;
When it is detected that the fastening portion is in a non-releasable fixed state, control is performed so that the gear ratio of the continuously variable transmission is equal to or greater than a certain value so that the rotational speed of the internal combustion engine is reduced. .

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