JP6912339B2 - Hybrid vehicle power unit - Google Patents

Description

The present invention relates to a power unit of a hybrid vehicle including an engine and a motor generator (electric motor) as a driving force source.

In recent years, a hybrid electric vehicle (HEV) capable of effectively improving the fuel consumption rate (fuel efficiency) of a vehicle by using an engine and a motor / generator (electric motor) in combination has been widely put into practical use. By the way, as such a hybrid electric vehicle, various types such as series HEV, parallel HEV, strong HEV and mild HEV have been conventionally used, depending on the number of motor generators, the combination method and switching method of the engine and the motor generator, and the like. A format has been proposed and developed.

Here, Patent Document 1 includes a series HEV driving function in which an engine, two motors, and a generator are provided, and the motor is driven by the electric power generated by the engine (generator) to run, and both the engine and the motor are used. A hybrid vehicle having a parallel HEV traveling function for driving a vehicle and an EV traveling function for stopping an engine and traveling only with a motor is disclosed.

More specifically, in the hybrid vehicle described in Patent Document 1, the power of the engine and the motor (motor) is individually transmitted to the output shaft on the drive wheel side, and the power of the engine is also transmitted to the generator (generator). It has a transaxle. This transaxle has a first path for power transmission from the engine to the drive wheels, a second path for power transmission from the motor to the drive wheels, and a third path for power transmission from the engine to the generator. It is provided. An engine and a motor are connected in parallel to the drive wheels via a transaxle. Further, a generator and drive wheels are connected in parallel to the engine via a transaxle.

A hydraulic clutch that connects and disconnects the power transmission is interposed in the middle of the first path described above. The hydraulic clutch is engaged when the traveling speed of the vehicle is equal to or higher than a predetermined vehicle speed (during high-speed traveling). The engine is driven when the clutch is engaged, and the driving force is transmitted to the drive wheels via the first path. On the other hand, when the traveling speed of the vehicle is less than the predetermined vehicle speed (during medium / low speed traveling), the clutch is disengaged and the engine is disengaged.

The motor has both a function of assisting the driving force of the engine (parallel HEV running function) and a power running function (EV running function). When the vehicle starts or runs at low speed when the clutch is disengaged, the vehicle runs only by the driving force of the motor (EV running). Further, when the traveling speed of the vehicle becomes equal to or higher than a predetermined vehicle speed (during high-speed traveling), the driving force of the motor is added to the driving force of the engine according to the traveling state (parallel HEV traveling). As described above, the third path is a power transmission path connecting the crankshaft of the engine and the rotation shaft of the generator, and transmits power at the time of starting the engine and power transmission at the time of power generation (series HEV) by the engine. Carry.

As described above, the hybrid vehicle described in Patent Document 1 uses both the engine and the motor as the driving force source, and the series HEV traveling function that travels by using the motor as the driving force source while causing the generator to generate power by utilizing the engine output of the engine. It has a parallel HEV traveling function for traveling and an EV traveling function for traveling with a motor as a driving force source while the engine is stopped.

Japanese Unexamined Patent Publication No. 2013-180680

However, the hybrid vehicle having the above-described configuration has the following problems. That is, during medium- and low-speed running, when the hydraulic clutch is released, the engine is disengaged, and the motor runs (during series HEV running or EV running), a drag loss of the hydraulic clutch occurs.

Here, for example, when a clutch that mechanically interrupts each element is used instead of the hydraulic clutch (without using hydraulic pressure), the above-mentioned drag loss can be eliminated. However, when such a clutch is used, it is necessary to synchronize the rotation speed of each element when switching (engaging) the clutch. Therefore, for example, if the axle rotation speed (wheel rotation speed) changes when the traveling mode is switched (when the clutch is engaged), the elements constituting the clutch are contacted and fitted at different rotation speeds. If this is repeated, the durability of the clutch or the like may be deteriorated or damaged.

The present invention has been made to solve the above problems, and is a power unit of a hybrid vehicle including an engine and two motor generators, and having a series HEV driving mode, a parallel HEV driving mode, and an EV driving mode. The purpose of the present invention is to provide a power unit of a hybrid vehicle that can eliminate the drag loss when the engine is disengaged (when the clutch is released) and can smoothly switch the traveling mode without causing deterioration of the durability of the clutch. do.

The power unit of the hybrid vehicle according to the present invention includes an engine, a first motor generator, and a first spline that is connected to the output shaft of the engine so as to be able to transmit torque in the power unit of the hybrid vehicle including the second motor generator. , The second spline that is connected to the rotating shaft of the first motor generator so that torque can be transmitted, and the axle that transmits torque between the rotating shaft of the second motor generator and the drive wheels are connected so that torque can be transmitted. It has a spline formed so as to be matable with the first spline, the second spline, and the third spline, and the connection state of the first spline, the second spline, and the third spline depending on the position. The sleeve that switches between the two, the actuator that slides the sleeve, and the first spline and the second spline are connected in the series HEV driving mode, and the first spline, the second spline, and the third spline are connected in the parallel HEV driving mode. , A control means for controlling the drive of the actuator is provided so as to connect the second spline and the third spline in the EV driving mode, and the rotation speed of the axle changes when the control means requests to switch the traveling mode. Is less than the predetermined number of revolutions and the accelerator opening is less than the predetermined opening, the motor is controlled to switch the traveling mode, and the above condition is not satisfied. Controls the second motor generator so as to suppress the change in the number of rotations of the axle, and then determines again whether or not the above conditions are satisfied, and if the above conditions are satisfied, the actuator. The driving mode is switched by controlling the above, and if the above conditions are not satisfied, the switching of the driving mode is prohibited.

According to the power unit of the hybrid electric vehicle according to the present invention, the first spline connected to the output shaft of the engine so as to be able to transmit torque, and the second spline connected to the rotating shaft of the first motor generator so as to be able to transmit torque, It has a third spline that is connected to the rotating shaft and drive wheels of the second motor generator so that torque can be transmitted, and a spline that is formed so that it can be fitted with the first spline, the second spline, and the third spline. A sleeve for switching the connection state of the first spline, the second spline, and the third spline is provided accordingly, and the first spline and the second spline are connected in the series HEV driving mode, and the first spline in the parallel HEV driving mode. The second spline and the third spline are connected, and the couturer is controlled so that the second spline and the third spline are connected in the EV traveling mode, and the sleeve is moved. That is, the dog clutch is composed of the spline formed on the sleeve, the first spline, the second spline, and the third spline, and the dog clutch is engaged / released (that is, the spline formed on the sleeve and the first spline, By switching the second spline and the mated state with the third spline), the series HEV running mode, the parallel HEV running mode, and the EV running mode can be switched. Therefore, during EV traveling in which the engine is separated (the first spline is separated), a drag loss such as that of a hydraulic clutch does not occur.

Further, according to the power unit of the hybrid vehicle according to the present invention, when there is a request to switch the traveling mode, the change in the rotation speed of the axle is less than the predetermined rotation speed, and the accelerator opening is less than the predetermined opening degree. When the conditions are satisfied, the actuator is controlled (sleeve is slid) to switch the traveling mode. On the other hand, if the above conditions are not satisfied, it is determined again whether or not the above conditions are satisfied after the second motor generator is controlled (driven) so as to suppress the change in the rotation speed of the axle. Will be done. Then, when the above conditions are satisfied, the actuator is controlled to switch the traveling mode. On the other hand, if the above conditions are not satisfied again, the switching of the traveling mode is prohibited (sliding of the sleeve is prohibited). Therefore, when switching the dog clutch (driving mode), the traveling mode can be switched only when the change in the axle rotation speed and the accelerator opening are less than the preset threshold values (predetermined rotation speed and predetermined opening). Will be executed. Therefore, it is possible to prevent the elements constituting the dog clutch from being contacted and fitted at different rotation speeds. As a result, the drag loss when the engine is disengaged (when the clutch is released) can be eliminated, and the traveling mode can be smoothly switched without causing deterioration of the durability of the clutch.

In the power unit of the hybrid vehicle according to the present invention, the control means is a parallel in which the first spline, the second spline, and the third spline are connected from the series HEV driving mode in which the first spline and the second spline are connected. When switching the driving mode to the HEV driving mode, if the condition that the change in the rotation speed of the axle is less than the predetermined rotation speed and the accelerator opening is less than the predetermined opening is satisfied, the actuator is controlled. Then, the driving mode is switched, and if the above conditions are not satisfied, the second motor generator is controlled so as to suppress the change in the rotation speed of the axle, and then whether or not the above conditions are satisfied again. When the above conditions are satisfied, it is preferable to control the actuator to switch the traveling mode, and when the above conditions are not satisfied, it is preferable to prohibit the switching of the traveling mode.

By the way, for example, in a situation where the opening degree of the accelerator pedal changes greatly or the rotation speed of the axle changes greatly due to a change in the road surface, from the series HEV driving mode in which the first spline and the second spline are connected. If the driving mode is switched to the parallel HEV driving mode in which the first spline, the second spline, and the third spline are connected, each element constituting the dog clutch may be contacted and fitted at different rotation speeds. .. On the other hand, in this case, the above-mentioned switching control is executed when the traveling mode is switched from the series HEV traveling mode to the parallel HEV traveling mode. That is, when the traveling mode is switched, the change (fluctuation) in the rotation speed of the axle is suppressed by the second motor generator as necessary. Therefore, it becomes easy to synchronize the rotation of each element constituting the dog clutch, and it becomes possible to switch the traveling mode more smoothly.

The power unit of the hybrid vehicle according to the present invention includes an engine, a first motor generator, and a first spline that is connected to the output shaft of the engine so as to be able to transmit torque in the power unit of the hybrid vehicle including the second motor generator. , The second spline that is connected to the rotating shaft of the first motor generator so that torque can be transmitted, and the axle that transmits torque between the rotating shaft of the second motor generator and the drive wheels are connected so that torque can be transmitted. It has a spline formed so as to be matable with the first spline, the second spline, and the third spline, and the connection state of the first spline, the second spline, and the third spline depending on the position. The sleeve that switches between the two, the actuator that slides the sleeve, and the first spline and the second spline are connected in the series HEV driving mode, and the first spline, the second spline, and the third spline are connected in the parallel HEV driving mode. , A control means for controlling the drive of the actuator is provided so as to connect the second spline and the third spline in the EV driving mode, and the rotation speed of the axle changes when the control means requests to switch the traveling mode. Is less than the first predetermined rotation speed and the first condition that the accelerator opening is less than the first predetermined opening is satisfied, the actuator is controlled to switch the traveling mode, and the first If the condition is not satisfied, whether or not the second condition that the change in the axle rotation speed is less than the second predetermined rotation speed and the accelerator opening is less than the second predetermined opening degree is satisfied. When the above-mentioned second condition is satisfied, the second motor / generator is controlled so as to suppress the change in the rotation speed of the axle, and then the actuator is controlled to switch the traveling mode. When the conditions are not satisfied, the switching of the traveling mode is prohibited.

According to the power unit of the hybrid vehicle according to the present invention, as described above, the first spline connected to the output shaft of the engine so as to be able to transmit torque, and the rotating shaft of the first motor generator are connected to be able to transmit torque. A second spline, a third spline that is connected to the rotating shaft and drive wheels of the second motor generator so as to be able to transmit torque, and a spline that is formed so as to be matable with the first spline, the second spline, and the third spline. It has a sleeve that switches the connection state of the first spline, the second spline, and the third spline according to the position, and the first spline and the second spline are connected in the series HEV driving mode, and the parallel HEV driving mode. Sometimes the first spline, the second spline, and the third spline are connected, and the couturer is controlled to move the sleeve so that the second spline and the third spline are connected in the EV driving mode. That is, the dog clutch is composed of the spline formed on the sleeve, the first spline, the second spline, and the third spline, and the dog clutch is engaged / released (that is, the spline formed on the sleeve and the first spline, By switching the second spline and the mated state with the third spline), the series HEV running mode, the parallel HEV running mode, and the EV running mode can be switched. Therefore, during EV traveling in which the engine is separated (the first spline is separated), a drag loss such as that of a hydraulic clutch does not occur.

Further, according to the power unit of the hybrid vehicle according to the present invention, when there is a request to switch the traveling mode, the change in the rotation speed of the axle is less than the first predetermined rotation speed, and the accelerator opening degree is the first predetermined opening degree. When the first condition of less than is satisfied, the actuator is controlled (sleeve is slid) and the traveling mode is switched. On the other hand, when the first condition is not satisfied, the second condition that the change in the rotation speed of the axle is less than the second predetermined rotation speed and the accelerator opening is less than the second predetermined opening is satisfied. It is judged whether or not it is done. When the second condition is satisfied, the actuator is controlled after the second motor / generator is controlled (driven) so as to suppress the change in the rotation speed of the axle, and the traveling mode is switched. On the other hand, if the second condition is not satisfied, switching of the traveling mode is prohibited (sliding of the sleeve is prohibited). Therefore, when switching the dog clutch (driving mode), when the change in the rotation speed of the axle and the accelerator opening are less than the preset threshold values (first predetermined rotation speed and first predetermined opening), the driving mode Switching is executed. Therefore, it is possible to prevent the elements constituting the dog clutch from being contacted and fitted at different rotation speeds. As a result, the drag loss when the engine is disengaged (when the clutch is released) can be eliminated, and the traveling mode can be smoothly switched without causing deterioration of the durability of the clutch. In this case, when the above-mentioned second condition is not satisfied (for example, when it is presumed that the second motor generator cannot suppress the rotation change, or when it is not appropriate to suppress it), the rotation speed change is changed. Since the suppression process is not executed, it is possible to prevent unnecessary suppression operation.

In the power unit of the hybrid vehicle according to the present invention, the control means is a parallel in which the first spline, the second spline, and the third spline are connected from the series HEV driving mode in which the first spline and the second spline are connected. When the driving mode is switched to the HEV driving mode, the first condition that the change in the rotation speed of the axle is less than the first predetermined rotation speed and the accelerator opening is less than the first predetermined opening is satisfied. When the first condition is not satisfied, the change in the number of revolutions of the axle is less than the second predetermined number of revolutions and the accelerator opening is the second predetermined number. It is determined whether or not the second condition of less than the opening degree is satisfied, and if the second condition is satisfied, the second motor generator is controlled so as to suppress the change in the rotation speed of the axle. After that, it is preferable to control the actuator to switch the traveling mode, and if the second condition is not satisfied, the switching of the traveling mode is prohibited.

As described above, for example, in a situation where the opening degree of the accelerator pedal changes significantly or the number of revolutions of the axle changes significantly due to a change in the road surface, the series HEV in which the first spline and the second spline are connected is connected. If the driving mode is switched from the driving mode to the parallel HEV driving mode in which the first spline, the second spline, and the third spline are connected, the elements constituting the dog clutch are contacted and fitted at different rotation speeds. There is a risk. On the other hand, in this case, the above-mentioned switching control is executed when the traveling mode is switched from the series HEV traveling mode to the parallel HEV traveling mode. That is, when the traveling mode is switched, the change (fluctuation) in the rotation speed of the axle is suppressed by the second motor generator as necessary. Therefore, it becomes easy to synchronize the rotation of each element constituting the dog clutch, and it becomes possible to switch the traveling mode more smoothly.

In the power unit of the hybrid vehicle according to the present invention, the control means is a parallel in which the first spline, the second spline, and the third spline are connected from the series HEV driving mode in which the first spline and the second spline are connected. When switching the driving mode to the HEV driving mode, the engine rotation speed is adjusted to the rotation speed at which the sleeve and the third spline can be fitted, and then the actuator is driven to drive the first spline, the second spline, and the second spline. 3 It is preferable to move the sleeve so that it is connected to the spline.

In this case, when the driving mode is switched from the series HEV driving mode in which the first spline and the second spline are connected to the parallel HEV driving mode in which the first spline, the second spline, and the third spline are connected, the driving mode is switched. After the engine speed is adjusted to a speed at which the sleeves (first and second splines) and the third spline can be fitted, the actuator is driven to drive the first, second and third splines. The sleeve is moved so that it is connected to the spline. That is, after the rotation change (fluctuation) of the axle is suppressed and the rotation speeds of the third spline (axle) and the sleeve (first spline and second spline (engine and first motor generator)) are adjusted ( That is, after the rotational deviation is reduced), the sleeve is moved so that the first and second splines and the third spline are connected. Therefore, it is possible to switch the driving mode from the series HEV driving mode to the parallel HEV driving mode while suppressing the shock.

In the power unit of the hybrid vehicle according to the present invention, the first spline, the second spline, the third spline, and the sleeve are arranged coaxially, and the sleeve is the outer periphery of the first spline, the second spline, and the third spline. It is preferable that the upper part is slidable in the axial direction.

In this case, the first spline, the second spline, the third spline, and the sleeve are arranged coaxially, and the sleeve slides axially on the outer periphery of the first spline, the second spline, and the third spline. It is configured to be movable. That is, the dog clutch is formed by the spline formed on the sleeve, the first spline, the second spline, and the third spline, and by moving the sleeve in the axial direction, the dog clutch is engaged / released (that is, formed on the sleeve). By switching between the spline and the first spline, the second spline, and the third spline), it is possible to switch between the series HEV running mode, the parallel HEV running mode, and the EV running mode.

Further, in the power unit of the hybrid vehicle according to the present invention, each of the first spline, the second spline, and the third spline are outer splines formed on the outer periphery of a shaft that can rotate relative to each other, and the sleeve is the first spline. It is preferable that an inner spline that is formed into a cylindrical shape that can be fitted onto the second spline and the third spline and extends in the axial direction along the inner peripheral surface is formed.

In particular, in this case, each of the first spline, the second spline, and the third spline is an outer spline formed on the outer circumference of a shaft that can rotate relative to each other, and the sleeve is the first spline, the second spline, and the third spline. It is formed in a cylindrical shape that can be fitted to the outside, and an inner spline extending in the axial direction is formed on the inner peripheral surface thereof. Therefore, a dog clutch in which three elements can be intermittently configured by an inner spline formed on a cylindrical sleeve and a first spline, a second spline, and a third spline composed of outer splines (that is, by a relatively simple configuration) is formed. Can be done.

Further, in the power unit of the hybrid vehicle according to the present invention, the total gear ratio of the torque transmission path transmitted from the second motor generator to the drive wheels is driven from the engine via the first spline, the sleeve, and the third spline. It is preferable that the gear is set to low gear rather than the total gear ratio of the torque transmission path transmitted to the wheels.

In general, electric motors can be used at higher speeds than engines. In this case, the total gear ratio of the torque transmission path transmitted from the second motor generator to the drive wheels is set to a lower gear than the total gear ratio of the torque transmission path transmitted from the engine to the drive wheels. Therefore, the engine and the second motor / generator can be operated efficiently.

According to the present invention, in a power unit of a hybrid vehicle including an engine and two motor generators and having a series HEV driving mode, a parallel HEV driving mode, and an EV driving mode, dragging when the engine is disengaged (when the clutch is released). The loss can be eliminated, and the traveling mode can be smoothly switched without causing deterioration of the durability of the clutch.

It is a skeleton diagram which shows the structure of the power unit of the hybrid vehicle which concerns on embodiment, and is a block diagram which shows the structure of the control system. It is a figure which shows the torque transmission path (thick line) through a dog clutch in a series HEV running mode. It is a figure which shows the torque transmission path (thick line) through a dog clutch in a parallel HEV running mode. It is a figure which shows the torque transmission path (thick line) through a dog clutch in an EV traveling mode. It is a flowchart which shows the processing procedure of the traveling mode switching processing (first control mode) by the power unit of the hybrid vehicle which concerns on embodiment. It is a flowchart which shows the processing procedure of the traveling mode switching processing (second control mode) by the power unit of the hybrid vehicle which concerns on embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are used for the same or corresponding parts. Further, in each figure, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

First, the configuration of the power unit 1 of the hybrid vehicle according to the embodiment will be described with reference to FIG. FIG. 1 is a skeleton diagram showing the configuration of the power unit 1 of the hybrid vehicle, and a block diagram showing the configuration of the control system thereof.

The hybrid vehicle includes an engine 10, a first motor generator 21, and a second motor generator 22 as a driving force source for the vehicle. The engine 10 may be of any type, and for example, an engine in which the thermal efficiency is improved by increasing the compression ratio by a high expansion ratio cycle is preferably used. The engine 10 is controlled by an engine control unit (hereinafter referred to as "ECU") 81.

Various sensors such as a crank angle sensor 96 that detects the rotation position (engine rotation speed) of the crankshaft are connected to the ECU 81. Based on these various acquired information and control information from the hybrid electric vehicle / control unit (hereinafter referred to as "HEV-CU") 80 described later, the ECU 81 determines the fuel injection amount, ignition timing, electronically controlled throttle valve, and the like. The engine 10 is controlled by controlling various devices of the above. Further, the ECU 81 transmits various information such as the engine speed to the HEV-CU80 via the CAN (Control Area Network) 100.

The output shaft 12 is connected to the crankshaft 10a of the engine 10 (corresponding to the output shaft described in the claims) via a flywheel damper 11 that absorbs rotational fluctuations of the engine 10. A first spline 31 is formed on the outer peripheral surface of the end of the output shaft 12. That is, the crankshaft 10a of the engine 10 is connected to the first spline 31 via the flywheel damper 11 and the output shaft 12 so as to be able to transmit torque.

The first motor generator 21 and the second motor generator 22 have both a function as a motor that converts the supplied electric power into mechanical power and a function as a generator that converts the input mechanical power into electric power. It is configured as a synchronous generator motor. That is, each of the first motor generator 21 and the second motor generator 22 operates as a motor that generates drive torque when the vehicle is driven, and operates as a generator when the vehicle is regenerated. The first motor generator 21 mainly operates as a generator, and the second motor generator 22 mainly operates as a motor.

The rotation shaft (input / output shaft) 21a of the first motor generator 21 is connected to the output shaft 24 via a pair of gears 23 (drive gear 23a and driven gear 23b). A second spline 32 is formed on the outer peripheral surface of the end of the output shaft 24. That is, the rotating shaft 21a of the first motor generator 21 is connected to the second spline 32 via the gear 23 and the output shaft 24 so as to be able to transmit torque.

The rotation shaft (input / output shaft) 22a of the second motor generator 22 is connected to the front drive shaft 40 (front wheel output shaft) via a pair of gears 25 (drive gear 25a and driven gear 25b). A hollow output shaft 27 is connected to the front drive shaft 40 via a pair of gears 26 (drive gear 26a and driven gear 26b). A third spline 33 is formed on the outer peripheral surface of the end of the output shaft 27. The output shaft 24 described above is rotatably arranged in the hollow portion (internal space) of the output shaft 27. That is, the rotating shaft 22a of the second motor generator 22 is connected to the third spline 33 via the gear 25, the front drive shaft 40, the gear 26, and the output shaft 27 so as to be able to transmit torque.

The front drive shaft 40 transmits torque between the front wheels (corresponding to the drive wheels described in the claims) and the front differential (front differential) 42 connected to the front wheels. That is, the front wheels are connected to the second motor generator 22 via the front drive shaft 40 and the gear 25 so as to be able to transmit torque, and the third spline is connected via the front drive shaft 40, the gear 26, and the output shaft 27. It is connected to 33 so that torque can be transmitted.

Therefore, the torque of the second motor generator 22 and the like transmitted to the front drive shaft 40 is transmitted to the front differential (front differential) 42. The front differential 42 is, for example, a bevel gear type differential device. The torque from the front differential 42 is transmitted to the left front wheel (not shown) via the left front wheel drive shaft and to the right front wheel (not shown) via the right front wheel drive shaft.

A propeller shaft (rear wheel output shaft) 60 is connected to the front drive shaft 40 via a pair of gears 28 (drive gear 28a and driven gear 28b). The propeller shaft 60 transmits torque between the rear wheels (corresponding to the drive wheels) and the rear differential (rear differential) 62 connected to the rear wheels (corresponding to the drive wheels).

The propeller shaft 60 is interposed with a transfer clutch 61 that adjusts the torque transmitted to the rear wheel side. The transfer clutch 61 controls the fastening force (that is, the torque distribution ratio to the rear wheels) according to the driving state of the four wheels (for example, the slip state of the front wheels) and the driving torque. Therefore, the torque transmitted to the propeller shaft 60 of the second motor generator 22 and the like is distributed according to the fastening force of the transfer clutch 61 and is also transmitted to the rear wheel side.

The torque transmitted to the propeller shaft 60 and adjusted (distributed) by the transfer clutch 61 is transmitted to the rear differential (rear differential) 62. A left rear wheel drive shaft and a right rear wheel drive shaft (not shown) are connected to the rear differential 62. The driving force from the rear differential 62 is transmitted to the left rear wheel (not shown) via the left rear wheel drive shaft and to the right rear wheel (not shown) via the right rear wheel drive shaft.

As described above, each of the first spline 31, the second spline 32, and the third spline 33 is an outer spline formed on the outer peripheral surface of a shaft (output shaft 12, output shaft 24, output shaft 27) that can rotate relative to each other. Is. The first spline 31 (output shaft 12), the second spline 32 (output shaft 24), and the third spline 33 (output shaft 27) are arranged coaxially.

Then, on the outer periphery (outside) of the first spline 31, the second spline 32, and the third spline 33, a spline 34a formed so as to be matable with the first spline 31, the second spline 32, and the third spline 33 is provided. A sleeve 34 is provided to switch the connection state of the first spline 31, the second spline 32, and the third spline 33 according to the position of the spline 34a. That is, the dog clutch 30 is composed of the first spline 31, the second spline 32, the third spline 33, and the sleeve 34.

Here, the sleeve 34 is formed in a cylindrical shape that can be externally fitted to the first spline 31, the second spline 32, and the third spline 33, and the inner spline 34a extending in the axial direction along the inner peripheral surface is formed. .. That is, the sleeve 34 is provided so as to be slidable (movable) in the axial direction on the outer periphery of the first spline 31, the second spline 32, and the third spline 33.

The sleeve 34 is slid by the actuator 75. The actuator 75 switches between the series HEV travel mode, the parallel HEV travel mode, and the EV travel mode by moving the sleeve 34 and switching the connection state of the first spline 31, the second spline 32, and the third spline 33. .. The actuator 75 moves the sleeve 34 to connect the first spline 31 and the second spline 32 in the series HEV travel mode, and the first spline 31, the second spline 32, and the third spline 33 in the parallel HEV travel mode. And, in the EV traveling mode, the second spline 32 and the third spline 33 are connected.

More specifically, the sleeve 34 is gripped by the shift fork 36 and slides in the axial direction as the shift fork 36 moves. The actuator 75 is connected to the shift fork 36, and the shift fork 36 (that is, the sleeve 34) is moved in the axial direction by the actuator 75, and the traveling mode is switched as described above. As the actuator 75, for example, an electric motor or the like is preferably used. The actuator 75 is driven and controlled by the HEV-CU 80 described later.

Here, the total gear ratio of the torque transmission path transmitted from the second motor generator 22 to the front wheels (front differential 42) or the rear wheels (rear differential 62) is the first spline 31, the sleeve 34, and the third spline 33. The gear is set to a lower gear than the total gear ratio of the torque transmission path transmitted from the engine 10 to the front wheels (front differential 42) or the rear wheels (rear differential 62).

Further, as a fail-safe measure, the dog clutch 30 (or the actuator 75) is connected to the second spline 32 and the third spline 33 when an abnormality (fail) occurs in the actuator 75 that drives the sleeve 34. A return spring 35 for urging the sleeve 34 (that is, returning the sleeve 34) is provided in the direction from the EV traveling mode state to the series HEV traveling mode state in which the first spline 31 and the second spline 32 are connected. ing.

Therefore, when an abnormality (fail) occurs in the actuator 75, the sleeve 34 is automatically returned to the series HEV traveling mode state (default position) in which the first spline 31 and the second spline 32 are connected. Here, the abnormality of the actuator 75 is a state in which the actuator 75 cannot generate a driving force, and examples thereof include a disconnection, a short circuit, and a drive circuit failure. Further, the abnormality of the actuator 75 can be determined based on, for example, the deviation between the indicated value (control value) and the actual value (actual current value, actual operation amount, etc.).

Further, the power supply system for supplying electric power to the actuator 75 is a dual system. More specifically, the power supply system lowers the voltage from a high-voltage battery 70 of about several hundred V, which supplies power to the first motor generator 21 and the second motor generator 22, to 12 V via a DC / DC converter 71. A dual system having a first power supply path 73 for supplying the supplied power and a second power supply path 74 for supplying power from the low voltage battery 72 whose output terminal voltage is lower than that of the high voltage battery 70 (for example, 12 V). It is said that. Then, when an abnormality (fail) occurs in one of the first power supply path 73 and the second power supply path 74 (for example, the second power supply path 74) (for example, when a disconnection occurs). ), The power is supplied from the other power supply path (for example, the first power supply path 73) (that is, the power supply path is switched).

The engine 10, the second motor generator 22, and the first motor generator 21, which are the driving force sources of the vehicle, are comprehensively controlled by the HEV-CU 80. The HEV-CU 80 also controls the drive of the actuator 75 (sleeve 34).

The HEV-CU80 includes a microprocessor that performs calculations, a ROM that stores programs for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, and a backup RAM that holds the stored contents. It is configured to have an input / output I / F and the like.

The HEV-CU80 includes, for example, an accelerator pedal sensor 91 that detects the amount of depression of the accelerator pedal, a throttle opening sensor 92 that detects the opening degree of the throttle valve, and a G sensor (acceleration sensor) that detects the front-rear and left-right acceleration of the vehicle. ) 93, a vehicle speed sensor 94 that detects the speed of the wheels, a rotation speed sensor 95 that detects the rotation speed of the front drive shaft 40, a resolver 97 that detects the rotation position (rotation speed) of the first motor generator 21. 2 Various sensors including a resolver 98 that detects the rotation position (rotation speed) of the motor generator 22 and a temperature sensor 99 that detects the temperature of the first and second motor generators 21 and 22 are connected. In addition, the HEV-CU80 interacts with the ECU 81 that controls the engine 10 via the CAN 100, the vehicle dynamic control unit (hereinafter referred to as "BDCU") 85 that suppresses skidding of the vehicle and improves the running stability, and the like. Is connected so that it can communicate with. The HEV-CU80 receives various information such as the engine speed and the brake operation amount from the ECU 81 and the VDCU85 via the CAN100.

Based on these various acquired information, the HEV-CU 80 comprehensively controls the drive of the engine 10, the second motor generator 22, and the first motor generator 21, and drives the actuator 75 (sleeve 34). Then, the driving mode is switched between the series HEV driving mode, the parallel HEV driving mode, and the EV driving mode. The HEV-CU 80 requests the engine 10 based on, for example, the accelerator pedal opening (driver's required driving force), the operating state of the vehicle, the charging state (SOC) of the high-voltage battery 70, the BSFC of the engine 10, and the like. The output, the torque command value of the second motor generator 22 and the first motor generator 21 are obtained and output, and the drive command value (control target value) of the actuator 75 is output.

The ECU 81 adjusts, for example, the opening degree of the electronically controlled throttle valve based on the required output. Further, the power control unit (hereinafter referred to as “PCU”) 82 drives the second motor generator 22 and the first motor generator 21 via the inverter 82a based on the torque command value. Here, the inverter 82a converts the DC power of the high-voltage battery 70 into three-phase AC power and supplies it to the second motor generator 22 and the first motor generator 21. On the other hand, the inverter 82a charges the high-voltage battery 70 by converting the AC voltage generated by the second motor generator 22 (and / or the first motor generator 21) into a DC voltage at the time of regeneration or the like.

The HEV-CU 80 functionally has a switching control unit 80a for driving an actuator 75 (sleeve 34) to switch a traveling mode between a series HEV traveling mode, a parallel HEV traveling mode, and an EV traveling mode. ing. In the HEV-CU80, the function of the switching control unit 80a is realized by executing the program stored in the ROM or the like by the microprocessor. The switching control unit 80a functions as the control means described in the claims.

The switching control unit 80a performs switching control of the traveling mode mainly based on the required driving force and the vehicle speed. More specifically, the switching control unit 80a selects, for example, an EV traveling mode in which the engine is stopped and the vehicle travels with the driving force of the first motor generator 21 and / or the second motor generator 22 at the time of starting. do. Further, the switching control unit 80a uses the electric power generated by the first motor generator 21 to drive the second motor when the SOC of the high voltage battery 70 is low or when the vehicle is running at a low speed (during a low load). The series HEV driving mode in which the generator 22 is driven to run is selected. Further, the switching control unit 80a is a parallel HEV that travels by the driving force of the first motor generator 21 and / or the second motor generator 22 and the driving force of the engine 10 when the vehicle speed is higher than a predetermined vehicle speed. Select the driving mode.

When selecting the series HEV travel mode, the switching control unit 80a controls (drives) the actuator 75 (sleeve 34) so as to connect the first spline 31 and the second spline 32. Further, when the parallel HEV traveling mode is selected, the switching control unit 80a controls (drives) the actuator 75 (sleeve 34) so as to connect the first spline 31, the second spline 32, and the third spline 33. Further, when the EV traveling mode is selected, the switching control unit 80a controls (drives) the actuator 75 (sleeve 34) so as to connect the second spline 32 and the third spline 33.

By being configured as described above, the power unit 1 of the hybrid vehicle according to the present embodiment is an EV traveling with the engine stopped and traveling with the driving force of the first motor generator 21 and / or the second motor generator 22. Function, series HEV running function that drives and runs the second motor generator 22 using the power generated by the first motor generator 21, the driving force of the first motor generator 21 and / or the second motor generator 22 It exhibits a parallel HEV running function that runs by the driving force of the engine 10 and the engine 10.

Here, FIG. 2 shows a torque transmission path (indicated by a thick line) via the dog clutch 30 in the series HEV driving mode. Similarly, FIG. 3 shows a torque transmission path (indicated by a thick line) via the dog clutch 30 in the parallel HEV driving mode. Further, FIG. 4 shows a torque transmission path (indicated by a thick line) via the dog clutch 30 in the EV traveling mode.

As shown by the thick line in FIG. 2, in the series HEV driving mode, the sleeve 34 is slid toward the left side of the drawing (from the center position) to connect the first spline 31 and the second spline 32. That is, the engine 10 and the first motor generator 21 are connected via the first spline 31, the sleeve 34, and the second spline 32. On the other hand, the second motor generator 22 is connected to the axle (front drive shaft 40 and propeller shaft 60). Therefore, the first motor generator 21 is driven by the engine 10 to operate as a generator, and the second motor generator 22 is driven by the electric power generated by the first motor generator 21 to drive the driving wheels (vehicle). Is driven. In this case, since the axles (front drive shaft 40 and propeller shaft 60) are shut off without using the hydraulic clutch, the clutch drag loss does not occur.

In the parallel HEV traveling mode, as shown by the thick line in FIG. 3, the sleeve 34 is slid to the center position to connect the first spline 31, the second spline 32, and the third spline 33. That is, the engine 10, the first motor generator 21, the second motor generator 22, and the axle (front drive shaft 40 and propeller shaft 60) are connected. Therefore, the drive wheels (vehicles) are driven by the engine 10, the second motor generator 22, and / or the first motor generator 21. In this case, since the three elements (first spline 31, second spline 32, third spline 33) are fastened without using the hydraulic clutch, the loss due to flood control (oil pump loss, sealing friction, etc.) Does not occur.

In the EV traveling mode, as shown by the thick line in FIG. 4, the sleeve 34 is slid to the right side of the drawing (from the center position) to connect the second spline 32 and the third spline 33. That is, the first motor generator 21, the second motor generator 22, and the axle (front drive shaft 40 and propeller shaft 60) are connected. Therefore, the drive wheels (vehicles) are driven by the second motor generator 22 and / or the first motor generator 21. In this case, since the engine 10 is shut off without using the hydraulic clutch, the clutch drag loss does not occur. Further, in addition to the second motor generator 22, the first motor generator 21 can also be used for EV drive, so that powerful EV traveling becomes possible.

Further, the HEV-CU80 (switching control unit 80a) is a parallel HEV running mode in which the first spline, the second spline, and the third spline are connected from the series HEV running mode in which the first spline and the second spline are connected. When the traveling mode is switched to the mode, it has a function (first control mode and second control mode) of smoothly switching the traveling mode without causing deterioration of the durability of the dog clutch 30.

(First control mode)
Therefore, first, the first control mode will be described. In the switching control unit 80a, the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60) is less than a predetermined number of revolutions (for example, the change in the number of revolutions corresponding to the vehicle acceleration / deceleration of 0.2 G), and the accelerator opening degree. It is determined whether or not the condition (switching condition) that the (required driving force) is less than a predetermined opening degree (for example, 50%) is satisfied. Here, when the above conditions are satisfied, the switching control unit 80a controls the actuator 75 (sliding the sleeve 34) to switch the traveling mode from the series HEV traveling mode to the parallel HEV traveling mode.

When switching the traveling mode from the series HEV traveling mode to the parallel HEV traveling mode, the switching control unit 80a sets the rotation speed of the engine 10 (or the first motor / generator 21) to the sleeve 34 (first spline 31). After adjusting the second spline 32) and the third spline 33 to a matable rotation speed (after adjusting the rotation speed), the actuator 75 is driven to drive the first spline 31 and the second spline 32 and the second spline 32. It is preferable to move the sleeve 34 so as to connect the three splines 33.

On the other hand, when the above conditions are not satisfied, the switching control unit 80a controls (drives) the second motor generator 22 so as to suppress the change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60). do. More specifically, the switching control unit 80a switches the traveling mode in a situation where the rotation speed of the axle (wheel) changes (fluctuations), for example, on an uphill road, a downhill road, or an uneven road surface. At that time, the drive torque of the second motor / generator 22 is adjusted (increased / decreased) according to the change (fluctuation) in the rotation speed of the axle (wheel) to suppress the change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60). do.

After that (after controlling the second motor generator 22 so as to suppress the change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60)), the switching control unit 80a again satisfies the above conditions. To judge. That is, in the switching control unit 80a, the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60) is less than the predetermined number of revolutions (for example, the change in the number of revolutions corresponding to the vehicle acceleration / deceleration of 0.2 G). , It is determined whether or not the condition that the accelerator opening degree (required driving force) is less than a predetermined opening degree (for example, 50%) is satisfied. Then, when the above conditions are satisfied, the switching control unit 80a controls the actuator 75 (sliding the sleeve 34) to switch the traveling mode from the series HEV traveling mode to the parallel HEV traveling mode.

On the other hand, if the above conditions are not yet satisfied even after suppressing the change in the rotation speed, the switching control unit 80a prohibits the switching of the traveling mode (prohibits the sliding of the sleeve 34). Therefore, when the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60) cannot be suppressed by the second motor / generator 22, for example, when the driver's accelerator depression amount is very large, or when the road surface μ When the number of rotations of the wheels (axles) changes significantly due to a sudden change, switching from the series HEV driving mode to the parallel HEV driving mode is prohibited.

(Second control mode)
Next, the second control mode will be described. In this control mode, the vehicle travels from the series HEV travel mode in which the first spline 31 and the second spline 32 are connected to the parallel HEV travel mode in which the first spline 31, the second spline 32, and the third spline 33 are connected. When switching the mode, first, in the switching control unit 80a, the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60) is the first predetermined number of revolutions (for example, the change in the number of revolutions corresponding to the vehicle acceleration / deceleration of 0.2 G). ), And it is determined whether or not the first condition that the accelerator opening degree (required driving force) is less than the first predetermined opening degree (for example, 50%) is satisfied. Then, when the first condition is satisfied, the switching control unit 80a controls the actuator 75 (sliding the sleeve 34) to switch the traveling mode.

As described above, when the switching control unit 80a switches the traveling mode from the series HEV traveling mode to the parallel HEV traveling mode, the rotation speed of the engine 10 (or the first motor / generator 21) is set to the sleeve 34 (the first). After adjusting the rotation speeds of the 1st spline 31 and the 2nd spline 32) and the 3rd spline 33 to a matable rotation speed (after adjusting the rotation speeds), the actuator 75 is driven to drive the 1st spline 31 and the 2nd spline. It is preferable to move the sleeve 34 so that the spline 32 and the third spline 33 are connected.

On the other hand, when the first condition is not satisfied, the switching control unit 80a changes the rotation speed of the axle (front drive shaft 40 / propeller shaft 60) to the second predetermined rotation speed (for example, 0.5 G vehicle adjustment). It is determined whether or not the second condition that the accelerator opening (required driving force) is less than the second predetermined opening (for example, 50%) is satisfied. .. Here, each value (threshold value) is set so that the first predetermined rotation speed ≦ the second predetermined rotation value and the first predetermined opening ≦ the second predetermined opening. Further, the second predetermined rotation speed and the second predetermined opening degree determine whether or not the rotation change of the axle (front drive shaft 40 / propeller shaft 60) can be suppressed by the second motor generator 22 and the rotation change is suppressed. It is set in consideration of whether or not it is appropriate to do so. In this control mode, the first predetermined opening degree = the second predetermined opening degree, but the first predetermined opening degree may be less than the second predetermined opening degree.

When the second condition is satisfied, the switching control unit 80a controls (drives) the second motor generator 22 so as to suppress the change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60). do. That is, the switching control unit 80a adjusts (increases / decreases) the drive torque of the second motor / generator 22 according to the change (fluctuation) in the rotation speed of the axle (wheel), and adjusts (increases / decreases) the drive torque of the axle (front drive shaft 40 / propeller shaft 60). Suppress changes in rotation speed. After that, the actuator 75 is controlled (sliding the sleeve 34) to switch the traveling mode from the series HEV traveling mode to the parallel HEV traveling mode. On the other hand, if the second condition is not satisfied, the switching control unit 80a prohibits switching of the traveling mode (prohibits sliding of the sleeve 34).

Next, the operation of the power unit 1 of the hybrid vehicle will be described with reference to FIGS. 5 and 6. FIG. 5 is a flowchart showing a processing procedure of the traveling mode switching process (first control mode) by the power unit 1 of the hybrid vehicle. FIG. 6 is a flowchart showing a processing procedure of the traveling mode switching process (second control mode) by the power unit 1 of the hybrid vehicle. This process is repeatedly executed at a predetermined timing mainly in the HEV-CU80. Here, a process for switching the driving mode from the series HEV driving mode to the parallel HEV driving mode will be described.

First, the processing procedure of the first control mode will be described. In step S100, the running mode is changed from the series HEV running mode in which the first spline 31 and the second spline 32 are connected to the parallel HEV running mode in which the first spline 31, the second spline 32, and the third spline 33 are connected. Judgment is made as to whether or not there is a request (command) to switch. Here, if there is no request to switch the driving mode from the series HEV driving mode to the parallel HEV driving mode, the process is temporarily exited. On the other hand, when there is a request to switch the traveling mode from the series HEV traveling mode to the parallel HEV traveling mode, the process shifts to step S102.

In step S102, the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60) is less than the predetermined number of revolutions (for example, the change in the number of revolutions corresponding to the vehicle acceleration / deceleration of 0.2 G), and the accelerator opening (request). It is determined whether or not the condition (predetermined switching condition) that the driving force) is less than a predetermined opening degree (for example, 50%) is satisfied. Here, if the above conditions are satisfied, the process proceeds to step S104. On the other hand, when the above conditions are not satisfied, the process shifts to step S106.

In step S104, the rotation speed of the engine 10 (or the first motor generator 21) is adjusted to the rotation speed at which the sleeve 34 (first spline 31 and the second spline 32) and the third spline 33 can be fitted. After that (after the rotation speed adjustment is performed), the actuator 75 is driven to move the sleeve 34 so that the first spline 31, the second spline 32, and the third spline 33 are connected. Therefore, the driving mode is switched from the series HEV driving mode to the parallel HEV driving mode. After that, the process is temporarily exited.

On the other hand, in step S106, the second motor generator 22 is controlled (driven) so as to suppress the change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60). That is, the drive torque of the second motor / generator 22 is adjusted (increased / decreased) according to the change (fluctuation) in the rotation speed of the axle (wheel), and the change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60) is suppressed. NS. Then, in step S108, it is determined again whether or not the above conditions are satisfied. That is, the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60) is less than the predetermined number of revolutions (for example, the change in the number of revolutions corresponding to the vehicle acceleration / deceleration of 0.2 G), and the accelerator opening (required driving force). ) Is less than a predetermined opening degree (for example, 50%), it is determined whether or not the condition is satisfied.

Here, if the above conditions are satisfied, the process proceeds to step S104 described above. Then, as described above, the rotation speed of the engine 10 (or the first motor generator 21) becomes the rotation speed at which the sleeve 34 (the first spline 31 and the second spline 32) and the third spline 33 can be fitted. After the adjustment, the actuator 75 is driven to move the sleeve 34 so that the first spline 31, the second spline 32, and the third spline 33 are connected. Therefore, the driving mode is switched from the series HEV driving mode to the parallel HEV driving mode. After that, the process is temporarily exited. On the other hand, if the above conditions are not satisfied again, the process proceeds to step S110.

In step S110, switching of the traveling mode from the series HEV traveling mode to the parallel HEV traveling mode is prohibited (sliding of the sleeve 34 is prohibited). That is, the traveling mode is maintained (held) as the series HEV mode. After that, the process is temporarily exited.

Next, the processing procedure of the second control mode will be described. First, in step S200, the series HEV driving mode in which the first spline 31 and the second spline 32 are connected is changed to the parallel HEV driving mode in which the first spline 31, the second spline 32, and the third spline 33 are connected. A judgment is made as to whether or not there is a request (command) for switching the traveling mode. Here, if there is no request to switch the driving mode from the series HEV driving mode to the parallel HEV driving mode, the process is temporarily exited. On the other hand, when there is a request to switch the traveling mode from the series HEV traveling mode to the parallel HEV traveling mode, the process shifts to step S202.

In step S202, the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60) is less than the first predetermined number of revolutions (for example, the change in the number of revolutions corresponding to the vehicle acceleration / deceleration of 0.2 G), and the accelerator opening degree. It is determined whether or not the first condition (first switching condition) that the (required driving force) is less than the first predetermined opening degree (for example, 50%) is satisfied. Here, if the first condition is satisfied, the process proceeds to step S204. On the other hand, when the first condition is not satisfied, the process shifts to step S206.

In step S204, the rotation speed of the engine 10 (or the first motor generator 21) is adjusted to the rotation speed at which the sleeve 34 (first spline 31 and the second spline 32) and the third spline 33 can be fitted. After that (after the rotation speed adjustment is performed), the actuator 75 is driven to move the sleeve 34 so that the first spline 31, the second spline 32, and the third spline 33 are connected. Therefore, the driving mode is switched from the series HEV driving mode to the parallel HEV driving mode. After that, the process is temporarily exited.

On the other hand, in step S206, the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60) is less than the second predetermined number of revolutions (for example, the change in the number of revolutions corresponding to the vehicle acceleration / deceleration of 0.5 G) and the accelerator. It is determined whether or not the second condition (second switching condition) that the opening degree (required driving force) is less than the second predetermined opening degree (for example, 50%) is satisfied. Here, if the second condition is satisfied, the process proceeds to step S208. On the other hand, when the second condition is not satisfied, the process shifts to step S210.

In step S208, the second motor generator 22 suppresses the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60). That is, the drive torque of the second motor / generator 22 is adjusted (increased / decreased) according to the change (fluctuation) in the rotation speed of the axle (wheel), and the change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60) is suppressed. NS. After that, the process shifts to step S204 described above, and the rotation speed of the engine 10 (or the first motor generator 21) causes the sleeve 34 (first spline 31 and second spline 32) and the third spline 33 to move. After being adjusted to a matable rotation speed, the actuator 75 is driven to move the sleeve 34 so that the first spline 31, the second spline 32, and the third spline 33 are connected. Therefore, the driving mode is switched from the series HEV driving mode to the parallel HEV driving mode. After that, the process is temporarily exited.

On the other hand, in step S210, switching of the traveling mode from the series HEV traveling mode to the parallel HEV traveling mode is prohibited (sliding of the sleeve 34 is prohibited). That is, the traveling mode is maintained (held) as the series HEV mode. After that, the process is temporarily exited.

As described in detail above, according to the present embodiment, torque can be transmitted to the first spline 31 connected to the output shaft 10a of the engine 10 so as to be able to transmit torque, and to the rotating shaft 21a of the first motor generator 21. The second spline 32 connected to the second spline 32, the third spline 33 connected to the rotating shaft 22a of the second motor generator 22 and the drive wheel so as to be able to transmit torque, and the first spline 31, the second spline 32, and the third spline. It has a spline 34a formed so as to be matable with the 33, and includes a sleeve 34 for switching the connection state of the first spline 31, the second spline 32, and the third spline 33 according to the position. Then, the first spline 31 and the second spline 32 are connected in the series HEV driving mode, the first spline 31, the second spline 32, and the third spline 33 are connected in the parallel HEV driving mode, and the first spline 33 is connected in the EV driving mode. The actuator 75 is controlled so that the two splines 32 and the third spline 33 are connected, and the sleeve 34 is moved. That is, the dog clutch 30 is formed by the spline 34a formed on the sleeve 34, the first spline 31, the second spline 32, and the third spline 33, and is formed in the engaged / released state of the dog clutch 30 (that is, the sleeve 34). By switching the spline 34a and the mated state of the first spline 31, the second spline 32, and the third spline 33), the series HEV travel mode, the parallel HEV travel mode, and the EV travel mode can be switched. Therefore, during EV traveling in which the engine 10 is separated (the first spline 31 is separated), a drag loss such as that of a hydraulic clutch does not occur.

Further, according to the present embodiment (first control mode), when there is a request to switch the traveling mode, the rotation speed change of the axle (front drive shaft 40 / propeller shaft 60) is less than a predetermined rotation speed, and When the condition that the accelerator opening degree is less than the predetermined opening degree is satisfied, the actuator 75 is controlled (sleeve 34 is slid) to switch the traveling mode. On the other hand, if the above conditions are not satisfied, the second motor generator 22 is controlled (driven) so as to suppress the change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60), and then again. It is determined whether or not the above conditions are satisfied. Then, when the above conditions are satisfied, the actuator 75 is controlled to switch the traveling mode. On the other hand, if the above conditions are not satisfied again, the switching of the traveling mode is prohibited (sliding of the sleeve 34 is prohibited). Therefore, when switching the dog clutch 30 (driving mode), the vehicle travels only when the change in the rotation speed of the axle (wheel) and the accelerator opening are less than the preset threshold values (predetermined rotation speed and predetermined opening). Mode switching is performed. Therefore, it is possible to prevent the elements constituting the dog clutch 30 from being contacted and fitted at different rotation speeds. As a result, the drag loss when the engine is disengaged (when the clutch is released) can be eliminated, and the traveling mode can be smoothly switched without causing deterioration in the durability of the dog clutch 30.

Similarly, according to the present embodiment (second control mode), when there is a request to switch the traveling mode, the rotation speed change of the axle (front drive shaft 40 / propeller shaft 60) is less than the first predetermined rotation speed. If there is and the first condition that the accelerator opening is less than the first predetermined opening is satisfied, the actuator 75 is controlled (sleeve 34 is slid) to switch the traveling mode. On the other hand, when the above first condition is not satisfied, the change in the number of revolutions of the axle (front drive shaft 40 / propeller shaft 60) is less than the second predetermined number of revolutions, and the accelerator opening is the second predetermined open. It is determined whether or not the second condition of less than the degree is satisfied. When the second condition is satisfied, the actuator is controlled (driven) after the second motor generator 22 is controlled (driven) so as to suppress the change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60). 75 is controlled and the traveling mode is switched. On the other hand, if the second condition is not satisfied, switching of the traveling mode is prohibited (sliding of the sleeve 34 is prohibited). Therefore, when the dog clutch 30 (running mode) is switched, the change in the rotation speed of the axle (wheel) and the accelerator opening are less than the preset threshold values (first predetermined rotation speed and first predetermined opening). Then, the traveling mode is switched. Therefore, it is possible to prevent the elements constituting the dog clutch 30 from being contacted and fitted at different rotation speeds. As a result, the drag loss when the engine is disengaged (when the clutch is released) can be eliminated, and the traveling mode can be smoothly switched without causing deterioration in the durability of the dog clutch 30. In this case, when the second condition is not satisfied (for example, when it is presumed that the second motor / generator 22 cannot suppress the rotation change, or when it is not appropriate to suppress it), the rotation speed change. Since the process of suppressing is not executed, it is possible to prevent unnecessary suppression operation.

Further, according to the present embodiment, the parallel HEV in which the first spline 31, the second spline 32, and the third spline 33 are connected from the series HEV driving mode in which the first spline 31 and the second spline 32 are connected. When the travel mode is switched to the travel mode, the above-mentioned switching control is executed. That is, when the traveling mode is switched, the rotation speed change (fluctuation) of the axle (front drive shaft 40 / propeller shaft 60) is suppressed by the second motor generator 22 as necessary. Therefore, it becomes easy to synchronize the rotation of each element constituting the dog clutch 30, and the traveling mode can be switched more smoothly.

Further, according to the present embodiment, the parallel HEV in which the first spline 31, the second spline 32, and the third spline 33 are connected from the series HEV traveling mode in which the first spline 31 and the second spline 32 are connected. When the driving mode is switched to the driving mode, the rotation speed of the engine 10 is adjusted to the rotation speed at which the sleeve 34 (first spline 31 and the second spline 32) and the third spline 33 can be fitted, and then the rotation speed is adjusted. The actuator 75 is driven to move the sleeve 34 so that the first spline 31, the second spline 32, and the third spline 33 are connected. That is, the rotational fluctuation of the axle (front drive shaft 40 / propeller shaft 60) is suppressed, and the third spline 31 (axle) and sleeve 34 (first spline 31 and second spline 32 (engine 10 and first motor generator 21) are suppressed. )), The sleeve 34 is moved so as to connect the first spline 31, the second spline 32, and the third spline 33 after the rotation number is adjusted (that is, after the rotation deviation is reduced). Therefore, it is possible to switch the driving mode from the series HEV driving mode to the parallel HEV driving mode while suppressing the shock.

According to the present embodiment, the first spline 31, the second spline 32, the third spline 33, and the sleeve 34 are arranged coaxially, and the sleeve 34 is the first spline 31, the second spline 32, It is configured to be slidable in the axial direction on the outer periphery of the third spline 33. That is, the dog clutch 30 is composed of the spline 34a formed on the sleeve 34, the first spline 31, the second spline 32, and the third spline 33, and the dog clutch 30 is fastened and released by moving the sleeve 34 in the axial direction. By switching the state (that is, the mating state of the spline 34a formed on the sleeve 34 and the first spline 31, the second spline 32, and the third spline 33), the series HEV running mode, the parallel HEV running mode, and the EV It is possible to switch the driving mode.

Further, according to the present embodiment, each of the first spline 31, the second spline 32, and the third spline 33 is formed on the outer periphery of a shaft (output shaft 12, output shaft 24, output shaft 27) that can rotate relative to each other. The outer spline, the sleeve 34 is formed in a cylindrical shape that can be fitted into the first spline 31, the second spline 32, and the third spline 33, and the inner spline 34a is formed on the inner peripheral surface along the axial direction. ing. Therefore, three elements can be intermittently connected (that is, by a relatively simple configuration) by the inner spline 34a formed on the cylindrical sleeve 34 and the first spline 31, the second spline 32, and the third spline 33 composed of the outer spline. Dog clutch 30 can be configured.

According to the present embodiment, the total gear ratio of the torque transmission path transmitted from the second motor generator 22 to the drive wheels is lower than the total gear ratio of the torque transmission path transmitted from the engine 10 to the drive wheels. Is set to. Therefore, each of the engine 10 and the second motor generator 22 can be operated efficiently.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified in various ways. For example, in the above embodiment, the engine 10 is started by the first motor generator 21, but a starter (or starter generator) for starting the engine 10 may be separately provided. Further, the configuration of the drive system composed of a plurality of gears and shafts is not limited to the above embodiment.

In the above embodiment, an electric actuator is used as the actuator 75 for moving the sleeve 34, but a hydraulic actuator may be used instead of the electric actuator, for example. Further, the drive control of the actuator 75 (sleeve 34) may be performed by another ECU instead of the HEV-CU80.

In the above embodiment, the case where the present invention is applied to an AWD vehicle (all-wheel drive vehicle) has been described as an example, but the present invention can also be applied to, for example, a 2WD vehicle (FF vehicle or FR vehicle).

Further, when suppressing a change in the rotation speed of the axle (front drive shaft 40 / propeller shaft 60), the wheel speed (vehicle speed) is used in place of or in addition to the rotation speed of the axle (front drive shaft 40 / propeller shaft 60). It may be configured to be controlled by using. Further, in addition to the above configuration, a synchro mechanism for synchronizing the rotation of the third spline 33 and the sleeve 34 may be provided between the second spline 32 and the third spline 33.

In addition to the above-described configuration, the drive gear 26a constituting the gear 26, that is, arranged between the drive wheels and the third spline 33, transmits torque from the third spline 33 to the drive wheels, while transmitting torque from the third spline 33 to the drive wheels. A one-way clutch that shuts off the torque from the drive wheels without transmitting the torque to the third spline 33 (that is, the engine 10 and the first motor generator 21 side) may be further provided. In this way, even when the third spline 33 and the second spline 32 are connected (EV traveling mode), the torque input from the drive wheels is not transmitted to the first motor generator 21 side. , The first motor generator 21 is not forcibly rotated by the torque input from the drive wheels. Therefore, the rotation speed of the first motor generator 21 can be adjusted (controlled) to an arbitrary rotation speed lower than the rotation speed of the axle. That is, the rotation speed of the first spline 31 (engine 10) and the rotation speed of the second spline 32 (first motor generator 21) can be matched. As a result, by moving the sleeve 34 to connect the first spline 31 and the second spline 32, it is possible to restart the engine 10 even in the EV traveling mode. Since the torque from the drive wheels is transmitted to the second motor generator 22, the regenerative operation can be performed by the second motor generator 22.

Further, in this case, in addition to the one-way clutch, it is preferable to provide a synchro mechanism 37 between the first spline 31 and the second spline 32 to synchronize the rotation of the first spline 31 and the sleeve 34. By doing so, when the sleeve 34 fitted with the second spline 32 is fitted with the first spline 31, even if the rotation speeds of the sleeve 34 and the first spline 31 are different, even if the rotation speeds of the sleeve 34 and the first spline 31 are different. The sleeve 34 and the first spline 31 can be connected more smoothly.

Further, in this case, when the HEV-CU 80 (switching control unit 80) restarts the stopped engine 10 while the vehicle is running on EV, the first motor generator 21 (second spline 32) After reducing the rotation speed to a rotation speed at which the sleeve 34 and the first spline 31 can be fitted, the actuator 75 is driven to connect the sleeve 34 so that the first spline 31 and the second spline 32 are connected. It is preferable to have a configuration that moves. In this case, after the rotation speeds of the first spline 31 (engine 10), the second spline 32, and the sleeve 34 (first motor generator 21) are adjusted (after the rotation deviation is reduced), the first spline The sleeve 34 is moved so that the 31 and the second spline 32 are connected. Therefore, the running mode can be switched and the engine 10 can be restarted while suppressing the shock.

1 Hybrid vehicle power unit 10 Engine 21 1st motor generator 22 2nd motor generator 30 Dog clutch 31 1st spline 32 2nd spline 33 3rd spline 34 Sleeve 34a Spline 35 Return spring (return mechanism)
37 Synchro mechanism 40 Front drive shaft (front wheel output shaft)
42 Front differential 50 One-way clutch 60 Propeller shaft (rear wheel output shaft)
61 Transfer Clutch 70 High Voltage Battery 71 DC-DC Converter 72 Low Voltage Battery 73 1st Power Supply Path 74 2nd Power Supply Path 75 Actuator 80 HEV-CU
80a Switching control unit 81 ECU
82 PCU
85 VDCU
91 Accelerator pedal sensor 92 Throttle opening sensor 93 G sensor (accelerometer)
94 Vehicle speed sensor (wheel speed sensor)
95 rpm sensor 100 CAN

Claims (8)

In the power unit of a hybrid vehicle including an engine, a first motor generator, and a second motor generator.
A first spline that is connected to the output shaft of the engine so that torque can be transmitted,
A second spline that is connected to the rotating shaft of the first motor generator so that torque can be transmitted,
A rotation shaft of the second motor / generator, an axle that transmits torque between the drive wheels, and a third spline that is connected so as to be able to transmit torque.
It has a spline formed so as to be matable with the first spline, the second spline, and the third spline, and depending on the position, the connection state of the first spline, the second spline, and the third spline can be changed. With a switching sleeve,
An actuator that slides the sleeve and
The first spline and the second spline are connected in the series HEV driving mode, the first spline, the second spline, and the third spline are connected in the parallel HEV driving mode, and the second spline is connected in the EV driving mode. A control means for controlling the drive of the actuator so as to connect the spline and the third spline is provided.
When there is a request to switch the traveling mode, the control means
When the condition that the change in the rotation speed of the axle is less than the predetermined rotation speed and the accelerator opening is less than the predetermined opening is satisfied, the actuator is controlled to switch the traveling mode, and the condition is described. If the above is not satisfied, the second motor / generator is controlled so as to suppress the change in the rotation speed of the axle.
After that, it is determined again whether or not the condition is satisfied, and if the condition is satisfied, the actuator is controlled to switch the traveling mode, and if the condition is not satisfied, the traveling mode is switched. A power unit for hybrid vehicles, which is characterized by prohibiting switching of driving modes. The control means travels from a series HEV travel mode in which the first spline and the second spline are connected to a parallel HEV travel mode in which the first spline, the second spline, and the third spline are connected. When switching modes
When the condition that the change in the rotation speed of the axle is less than the predetermined rotation speed and the accelerator opening is less than the predetermined opening is satisfied, the actuator is controlled to switch the traveling mode, and the condition is described. If the above is not satisfied, the second motor / generator is controlled so as to suppress the change in the rotation speed of the axle.
After that, it is determined again whether or not the condition is satisfied, and if the condition is satisfied, the actuator is controlled to switch the traveling mode, and if the condition is not satisfied, the traveling mode is switched. The power unit of a hybrid vehicle according to claim 1, wherein switching of a traveling mode is prohibited. In the power unit of a hybrid vehicle including an engine, a first motor generator, and a second motor generator.
A first spline that is connected to the output shaft of the engine so that torque can be transmitted,
A second spline that is connected to the rotating shaft of the first motor generator so that torque can be transmitted,
A rotation shaft of the second motor / generator, an axle that transmits torque between the drive wheels, and a third spline that is connected so as to be able to transmit torque.
It has a spline formed so as to be matable with the first spline, the second spline, and the third spline, and depending on the position, the connection state of the first spline, the second spline, and the third spline can be changed. With a switching sleeve,
An actuator that slides the sleeve and
The first spline and the second spline are connected in the series HEV driving mode, the first spline, the second spline, and the third spline are connected in the parallel HEV driving mode, and the second spline is connected in the EV driving mode. A control means for controlling the drive of the actuator so as to connect the spline and the third spline is provided.
When there is a request to switch the traveling mode, the control means
When the first condition that the change in the rotation speed of the axle is less than the first predetermined rotation speed and the accelerator opening is less than the first predetermined opening is satisfied, the actuator is controlled to travel. When the mode is switched and the first condition is not satisfied, the change in the rotation speed of the axle is less than the second predetermined rotation speed, and the accelerator opening is less than the second predetermined opening. Judge whether the conditions are satisfied and
When the second condition is satisfied, the second motor generator is controlled so as to suppress the change in the rotation speed of the axle, and then the actuator is controlled to switch the traveling mode, and the second condition is satisfied. A hybrid vehicle power unit characterized in that switching of the driving mode is prohibited if the vehicle is not satisfied. The control means travels from a series HEV travel mode in which the first spline and the second spline are connected to a parallel HEV travel mode in which the first spline, the second spline, and the third spline are connected. When switching modes
When the first condition that the change in the rotation speed of the axle is less than the first predetermined rotation speed and the accelerator opening is less than the first predetermined opening is satisfied, the actuator is controlled to travel. When the mode is switched and the first condition is not satisfied, the change in the rotation speed of the axle is less than the second predetermined rotation speed, and the accelerator opening is less than the second predetermined opening. Judge whether the conditions are satisfied and
When the second condition is satisfied, the second motor generator is controlled so as to suppress the change in the rotation speed of the axle, and then the actuator is controlled to switch the traveling mode, and the second condition is satisfied. The power unit of the hybrid vehicle according to claim 3, wherein the switching of the traveling mode is prohibited when the above is not satisfied. The control means travels from a series HEV travel mode in which the first spline and the second spline are connected to a parallel HEV travel mode in which the first spline, the second spline, and the third spline are connected. When switching the mode, the engine speed is adjusted to a speed at which the sleeve and the third spline can be fitted, and then the actuator is driven to the first spline and the second spline. The power unit of a hybrid vehicle according to claim 2 or 4, wherein the sleeve is moved so as to be connected to the third spline. The first spline, the second spline, the third spline, and the sleeve are coaxially arranged.
The sleeve according to any one of claims 1 to 5, wherein the sleeve is configured to be slidable in the axial direction on the outer periphery of the first spline, the second spline, and the third spline. The power unit of the hybrid vehicle described. Each of the first spline, the second spline, and the third spline is an outer spline formed on the outer circumference of a shaft that can rotate relative to each other.
The sleeve is formed in a cylindrical shape that can be fitted onto the first spline, the second spline, and the third spline, and is characterized in that an inner spline extending in the axial direction along the inner peripheral surface is formed. The power unit of the hybrid vehicle according to any one of claims 1 to 6. The total gear ratio of the torque transmission path transmitted from the second motor generator to the drive wheels is transmitted from the engine to the drive wheels via the first spline, the sleeve, and the third spline. The power unit of a hybrid vehicle according to any one of claims 1 to 7, wherein the gear ratio is set to a lower gear than the total gear ratio of the torque transmission path.

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