JP2014113004A - Control device for power transmission device - Google Patents

Abstract

In a power transmission device in which a rotor shaft is connected to a gear mechanism, the progress of wear of the rotor shaft is suppressed without providing a new member.
A transaxle control device includes a bearing that rotatably supports a rotor shaft of a motor generator MG2, and the rotor shaft is coupled to a sun gear of a reduction mechanism. The rotor shaft has a diameter-expanded portion formed with a contact surface facing the inner race of the bearing in the axial direction. The ECU is configured to increase the frequency of performing the motor torque reduction control for reducing the motor torque as the motor torque of the motor generator MG2 is larger when the motor generator MG2 is regenerated than when the motor torque is small.
[Selection] Figure 7

Description

  The present invention relates to a vehicle control device, and more particularly to a power transmission device control device in which a rotor of a motor generator is connected to a gear mechanism.

  As for the connection of the planetary gear mechanism in the power transmission device, there are various connection relations. For example, the sun gear is connected to the rotor shaft of the motor generator, the ring gear is connected to the output shaft, and the carrier is connected and fixed to the case. A transmission device is conventionally known (for example, Patent Document 1).

JP 2005-308094 A

  By the way, in a power transmission device for a vehicle, a helical gear (helical gear) whose engagement noise is smaller than that of a spur gear (spur gear) is often used. However, since the helical gear is a gear that generates a thrust force in the axial direction when transmitting power, for example, the sun gear generates a thrust force in the axial direction due to the meshing of the gear in the planetary gear mechanism. It will be.

  For this reason, in the thing of the said patent document 1, in order to suppress that a rotor shaft moves to an axial direction by the thrust force which a sun gear produced, it is supported by the said bearing on the rotor shaft supported rotatably by a bearing. In addition to the portion, a portion is provided in which a bearing race and an opposing surface that are opposed in the axial direction are formed. Accordingly, when a thrust force that moves the rotor shaft to the bearing side is generated in the rotor shaft due to the meshing of the gear in the planetary gear mechanism, the opposing surface hits (contacts) the bearing race, so that the shaft The movement of the rotor shaft in the direction is limited.

  However, if the rotor shaft and the bearing race rotate in a state where the opposing surface of the rotor shaft and the bearing race are in contact with each other, the following problems occur. That is, the rotor shaft and the bearing race basically rotate together, but a slight slip (rotational difference) in the rotational direction may occur between them. In addition, raw materials are generally used for the rotor, whereas the bearing race is usually quenched, so that the bearing race has higher hardness than the rotor. Therefore, if a minute slip in the rotational direction occurs between the opposed surface of the rotor shaft and the bearing race, the rotor shaft having a lower hardness than the bearing race will be worn. Furthermore, such wear of the rotor shaft tends to progress faster as the motor torque of the motor generator increases.

  In order to avoid the rotor shaft from being pressed against the bearing, it is conceivable to provide a plate or the like for suppressing the movement of the rotor due to the thrust force. However, if a plate or the like is separately provided in the power transmission device, there arises a new problem that the cost is increased and a space for installing the plate or the like must be secured.

  The present invention has been made in view of such a point, and an object of the present invention is to wear the rotor shaft without providing a new member in a power transmission device in which the rotor shaft of the motor generator is connected to the gear mechanism. It is in providing the technique which suppresses progress of this.

  In order to achieve the above object, the power transmission device control device according to the present invention does not provide a new member, but the rotor shaft wear is suppressed so as to suppress the progress of the wear of the rotor shaft by the operation control of the power transmission device. The motor torque is reduced more frequently as it progresses more easily.

  Specifically, the present invention is directed to a control device for a power transmission device that includes a bearing that rotatably supports a rotor shaft of a motor generator, and the rotor shaft is coupled to a gear mechanism.

  In addition to the portion supported by the bearing, the rotor shaft in this power transmission device has a portion where a bearing race of the bearing and a facing surface facing the rotor axial direction are formed.

  The control device includes control means for performing motor torque reduction control for reducing the motor torque of the motor generator, and the control means pushes the opposing surface against the bearing race by meshing of the gear in the gear mechanism. When a thrust force acting on the rotor shaft is generated on the rotor shaft, the motor torque reduction control is performed more frequently as the motor torque of the motor generator is larger than when the motor torque is smaller. It is configured.

  According to this configuration, when a thrust force that acts to press the opposing surface of the rotor shaft against the bearing race is generated on the rotor shaft, the opposing surface of the rotor shaft hits the bearing race, so that The movement of the rotor shaft is limited.

  However, if the rotor shaft rotates in a state where the opposing surface of the rotor shaft and the bearing race are in contact with each other, and a minute slip (rotational difference) occurs in the rotational direction, the rotor shaft having a lower hardness than the bearing race is worn. Thus, the progress of the wear tends to become faster as the motor torque of the motor generator increases.

  Therefore, the control means is configured to increase the frequency of performing the motor torque reduction control as the motor torque of the motor generator is larger than when the motor torque is small. As a result, the motor torque is more easily reduced as the rotor shaft wears more easily, so that the progress of the wear of the rotor shaft can be suppressed without providing a new member.

  Preferably, the power transmission device has a structure in which the thrust force is generated during regeneration of the motor generator, and the control means is configured such that the larger the regeneration torque of the motor generator is, the smaller the regeneration torque is. In comparison, the motor torque reduction control is performed more frequently.

  In this configuration, during regeneration of the motor generator, a thrust force that acts to press the opposite surface of the rotor shaft against the bearing race is generated, but control that always reduces the regenerative torque regardless of the degree of progress of wear of the rotor shaft. If it is performed, it will be difficult to sufficiently recover the regenerative energy.

  Therefore, the control means is configured to increase the frequency of performing the motor torque reduction control as the regenerative torque of the motor generator is larger than when the regenerative torque is small. Thereby, progress of wear of the rotor shaft during regeneration can be suppressed while recovery of regenerative energy is intended.

  By the way, when the motor generator is regenerated, for example, there is deceleration (accelerator off) or braking (brake on). However, since regeneration with the accelerator off is difficult to generate large regenerative torque in the first place. The progress of wear of the rotor shaft is not a problem.

  Therefore, preferably, the control means performs the motor torque reduction control when the motor generator is regenerated when the brake pedal is operated, as compared with a case where the regenerative torque is smaller as the regenerative torque of the motor generator is larger. The motor torque reduction control is executed by adjusting the brake pressure.

  In this configuration, since the motor torque reduction control is executed by adjusting the brake pressure, it is possible to reliably reduce the regenerative torque of the motor generator and reliably suppress the progress of wear of the rotor shaft during regeneration. .

  Preferably, the power transmission device is further driven by an engine rotational output and further includes an oil pump for supplying oil to the bearing, and the control means drives the engine when the motor generator is powered. It is configured as follows.

  By the way, in a power transmission device provided with an oil pump that is driven by the rotation output of the engine, for example, when the engine is stopped at the time of deceleration or braking and the motor generator is regenerated, the oil pump is not driven. The shaft and bearing are not lubricated. Further, the engine is stopped even during power running, and the oil pump is not driven, so that the rotor shaft and the bearing are not lubricated. Therefore, when regeneration is performed immediately after power running, regeneration of the motor generator is started in a state where the opposed surface of the rotor shaft and the bearing race are not lubricated by oil, so that the rotor shaft wears out. There is a risk of progress.

  Therefore, in this configuration, in preparation for the subsequent regeneration of the motor generator, the engine is intentionally driven even when the motor generator is powered. In this way, by driving the engine during the power running of the motor generator, the oil pump operates even during the power running, so that oil is supplied to the opposing surface of the rotor shaft and the bearing, Lubrication, cooling, and cleaning will be performed. As a result, in regeneration immediately after power running, lubrication of the opposing surface of the rotor shaft during power running and motor torque reduction control during regeneration are combined to further suppress the progress of wear of the rotor shaft. be able to.

  Preferably, the control means acquires a count value every predetermined time during regeneration of the motor generator, and performs the motor torque reduction control when a total value of the acquired count values becomes equal to or greater than a predetermined value. In addition, the count value is weighted so that the operating point with the larger motor torque becomes heavier.

  According to this configuration, the count value is weighted so that the operating point with a larger motor torque becomes heavier. Therefore, the greater the motor torque, the more easily the total value of the count values becomes equal to or greater than a predetermined value. Accordingly, the motor torque is more easily reduced as the rotor wear progresses more easily, so that the progress of the rotor wear can be more reliably suppressed.

  As described above, according to the control device for a power transmission device according to the present invention, the motor torque reduction control is performed as the motor torque of the motor generator increases, that is, as the rotor shaft wears more easily. Since it becomes easy, it can suppress that abrasion of a rotor shaft advances, without providing a new member.

1 is a schematic diagram illustrating a configuration of a hybrid vehicle according to an embodiment of the present invention. 1 is a skeleton diagram of a transaxle of a hybrid vehicle. It is sectional drawing which shows a transaxle roughly. It is a figure which expands and shows a rotor shaft. It is a figure explaining the braking force sharing by the cooperative control of a hydraulic brake and a regenerative brake. It is a map figure in which the relationship between the rotation speed of a motor and motor torque referred in ECU was prescribed | regulated. It is a flowchart which shows the control which ECU performs.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

-Overall configuration-
FIG. 1 is a schematic diagram illustrating a configuration of a hybrid vehicle according to the present embodiment. The hybrid vehicle 2 is an FF (front engine / front drive) hybrid vehicle, and includes a transaxle (power transmission device) including a motor generator MG1 mainly functioning as a generator, a motor generator MG2 mainly functioning as an electric motor, and the like. ) 1 is provided.

  Hybrid vehicle 2 exchanges electric power with motor generators MG1 and MG2 via inverter 8 and 9 in addition to transaxle 1, engine 7, inverters 8 and 9 for driving motor generators MG1 and MG2. The battery 10, a brake actuator 92 for controlling the brakes of the drive wheels 52, 53 and driven wheels (not shown), and an electronic control unit (hereinafter referred to as ECU (Electronic Control Unit)) for controlling the entire hybrid vehicle 2. 70).

  Various controls of the engine 7, for example, fuel injection control, ignition timing control, intake air amount adjustment control, and the like are performed by an engine electronic control unit (hereinafter also referred to as engine ECU) 24. The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 7, while the engine ECU 24 sends a throttle valve, a fuel injection valve, a spark plug, a variable valve timing mechanism, and the like (not shown). A drive control signal is output. The engine ECU 24 communicates with the ECU 70 and controls the operation of the engine 7 in accordance with a control signal from the ECU 70, and outputs data relating to the operating state of the engine 7 to the ECU 70 as necessary.

  Motor generator MG1 mainly supplies electric power for driving to motor generator MG2 by generating electric power and charges battery 10, and also controls the amount of power generation to change the rotational speed of rotor 12 (see FIG. 2). Thus, it also functions as a continuously variable transmission of the transaxle 1. On the other hand, the motor generator MG2 functions as an auxiliary power source for the engine 7 so as to assist smooth start and acceleration by functioning mainly as an electric motor, and also converts the kinetic energy of the vehicle into electric energy when the regenerative brake is operated. The battery 10 is charged. The configuration of motor generators MG1 and MG2 will be described later.

  Drive control of motor generators MG1 and MG2 is performed by a motor electronic control unit (hereinafter also referred to as motor ECU) 25. The motor ECU 25 detects, for example, a signal related to the rotational position of the rotors 12 and 22 (see FIG. 2) of the motor generators MG1 and MG2 detected by the rotational position sensors 13 and 14 and a current sensor (not shown). Signals necessary for driving and controlling motor generators MG1 and MG2, such as signals relating to phase current values applied to motor generators MG1 and MG2 are input. On the other hand, the motor ECU 25 outputs a switching control signal to the inverters 8 and 9. The motor ECU 25 is in communication with the ECU 70 and drives and controls the motor generators MG1 and MG2 in accordance with a control signal from the ECU 70, and outputs data related to the operating state of the motor generators MG1 and MG2 to the ECU 70 as necessary. Motor ECU 25 calculates the rotational speed of motor generators MG1 and MG2 based on signals from rotational position sensors 13 and 14.

  The battery 10 is controlled by a battery electronic control unit (hereinafter referred to as a battery ECU) 15. In the battery ECU 15, for example, the voltage value between terminals from the voltage sensor 16 installed between the terminals of the battery 10, the charge / discharge current value from the current sensor 17 attached to the output terminal on the positive electrode side of the battery 10, A signal necessary for controlling the battery 10 such as a signal related to a battery temperature from a temperature sensor 18 attached to the battery 10 is input. The battery ECU 15 communicates with the ECU 70 and outputs data related to the state of the battery 10 to the ECU 70 as necessary. Further, the battery ECU 15 calculates the remaining capacity (SOC) of the battery 10 based on the integrated value of the charging / discharging current detected by the current sensor 17, or the input of the battery 10 based on the calculated remaining capacity and the battery temperature. Calculate the output limit value.

  The brake actuator 92 is driven by a braking torque corresponding to the share of the brake in the required braking force set based on the pressure (master cylinder pressure) of the brake master cylinder 90 generated by the depression operation of the brake pedal 85 and the vehicle speed. The hydraulic pressures of the brake wheel cylinders 86 and 87 are adjusted so as to act on the wheels 52 and 53 and the driven wheels. In the following description, a case where a braking force is applied to the drive wheels 52 and 53 and the driven wheel by the operation of the brake actuator 92 is referred to as a hydraulic brake.

  The brake actuator 92 is controlled by a brake electronic control unit (hereinafter also referred to as a brake ECU) 94. The brake ECU 94 communicates with the ECU 70 and controls the drive of the brake actuator 92 according to a control signal from the ECU 70, and outputs data related to the brake actuator 92 to the ECU 70 as necessary. In FIG. 1, the brake wheel cylinder corresponding to the driven wheel is not shown.

  The ECU 70 includes a CPU (Central Processing Unit) 72, a ROM (Read Only Memory) 74, and a RAM (Random Access Memory) 76. The ROM 74 stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU 72 executes various arithmetic processes based on various control programs and maps stored in the ROM 74. The RAM 76 is a memory that temporarily stores calculation results in the CPU 72, data input from each sensor, and the like.

  The ECU 70 includes an ignition switch 80 for turning on and off the main power supply of the hybrid vehicle 2, a shift position sensor 82 for detecting the operation position of the shift lever 81, an accelerator pedal position sensor 84 for detecting the depression amount of the accelerator pedal 83, and a brake pedal. Various sensors and switches such as a brake pedal position sensor 89 and a vehicle speed sensor 88 for detecting the depression amount of 85 are connected. Then, the ECU 70 receives an ignition signal, a shift position signal, an accelerator opening signal, a brake pedal position signal, a vehicle speed, and the like from these various sensors and switches. Further, as described above, the ECU 70 exchanges various control signals and data with the engine ECU 24, the motor ECU 25, the brake ECU 94, and the battery ECU 15. The ECU 70, the engine ECU 24, the motor ECU 25, the brake ECU 94, and the battery ECU 15 correspond to the control means in the present invention.

-Transaxle configuration-
FIG. 2 is a skeleton diagram of a transaxle of a hybrid vehicle, and FIG. 3 is a cross-sectional view schematically showing the transaxle. In addition to motor generators MG 1 and MG 2, transaxle 1 includes a power split mechanism 30, a reduction mechanism 40, a differential 50, and an oil pump 60 that is driven by the rotational output of the engine 7.

  Motor generators MG1 and MG2 include stators 11 and 21 and rotors 12 and 22, respectively. The stators 11 and 21 are wound around a three-phase winding and are fixed to the transaxle case 3. The rotors 12 and 22 include permanent magnets and are rotatably supported by the transaxle case 3.

  More specifically, the rotor 12 of the motor generator MG1 has a rotor shaft 35 rotatably supported on the transaxle case 3 via radial bearings 26 and 27. In the center hole of the rotor shaft 35, the input shaft 4 to which the crankshaft 23 is connected is inserted through a radial bearing (not shown) so as to be relatively rotatable. On the other hand, the rotor 22 of the motor generator MG2 has a rotor shaft 36 rotatably supported by the transaxle case 3 via radial bearings 28 and 29. An oil pump drive shaft 5 is inserted into the center hole of the rotor shaft 36 so as to be relatively rotatable.

  As shown in FIGS. 3 and 4, the rotor shaft 36 of the motor generator MG2 has a pipe-shaped first supported portion 37 supported by a radial bearing 28 on the engine 7 side, and an inner diameter and an outer diameter of the first supported portion 37. A pipe-like second supported portion 38 that is larger than the support portion 37 and supported by a radial bearing 29 on the opposite side of the engine 7, and the radially outer sides of the first and second supported portions 37, 38. And an enlarged-diameter portion 39 provided on the surface. The enlarged diameter portion 39 is formed with an abutting surface (opposing surface) 39a that opposes the inner race (bearing race) 28a of the radial bearing 28 in the rotor axial direction. In the transaxle 1 of the present embodiment, as will be described later, a thrust force that acts to pull the rotor shaft 36 toward the engine 7 side may be generated by the meshing of the gear in the reduction mechanism 40. Hitting the inner race 28a restricts the movement of the rotor 22 in the rotor axial direction.

  The power split mechanism 30 is a single pinion gear type planetary gear mechanism, and includes a sun gear 31 formed of a helical external gear, a ring gear 32 formed of a helical internal gear, and a helical external gear. A plurality of pinion gears 33 and a carrier 34 are provided.

  The ring gear 32 is disposed concentrically with the sun gear 31 on the outer diameter side of the sun gear 31. The plurality of pinion gears 33 are arranged between the sun gear 31 and the ring gear 32 so as to be engaged with each other. The carrier 34 is interposed between the radially opposed sun gear 31 and the ring gear 32 so as to support the plurality of pinion gears 33 in a rotatable manner and to rotate through the revolution of the pinion gears 33.

  Sun gear 31 is connected to the inner diameter side of rotor 12 of motor generator MG1 so as to be integrally rotatable, for example, by spline fitting, and is arranged to be relatively rotatable on the outer diameter side of input shaft 4. The ring gear 32 is rotatably supported by the transaxle case 3 via a radial bearing (reference number omitted), and a counter drive gear 45 is integrally provided on the outer periphery thereof. The carrier 34 is attached to the inner end outer diameter side of the input shaft 4 so as to be integrally rotatable.

  As the operation of the power split mechanism 30, the driving force output from at least one of the engine 7 and the motor generator MG2 input through the input shaft 4 is used as a counter drive gear 45, a counter driven gear 46, a differential drive gear 47, a final ring gear. This is transmitted to the drive wheels 52 and 53 via 51 and the differential 50.

  The reduction mechanism 40 is a single pinion gear type planetary gear mechanism, and includes a sun gear 41 formed of a helical external gear, a ring gear 42 formed of a helical internal gear, and a plurality of helical gears. The pinion gear 43 and the carrier 44 are provided.

  The ring gear 42 is disposed concentrically with the sun gear 41 on the outer diameter side of the sun gear 41. The plurality of pinion gears 43 are disposed between the sun gear 41 and the ring gear 42 so as to be engaged with each other. The carrier 44 is interposed between the sun gear 41 and the ring gear 42 facing each other in the radial direction so as to support the plurality of pinion gears 43 so as to rotate and to rotate through the revolution of the pinion gears 43.

  Sun gear 41 is connected to the outer diameter side of rotor shaft 36 of motor generator MG2 so as to be integrally rotatable, for example, by spline fitting. The ring gear 42 is integrally connected so as to be side by side with the ring gear 32 of the power split mechanism 30. The carrier 44 is attached to the transaxle case 3 while being prevented from rotating, and is arranged side by side on the same axis as the input shaft 4 via a radial bearing 71. The radial bearing 71 regulates the movement of the carrier 44 in the axial direction, and prevents the non-rotating carrier 44 from directly contacting the input shaft 4 and causing rotational resistance of the input shaft 4. .

  As the operation of the reduction mechanism 40, the driving force output from at least one of the engine 7 and the motor generator MG2 is decelerated at an appropriate reduction ratio, and the reduced power is supplied to the counter drive gear 45, the counter driven gear 46, and the differential drive gear. 47, and transmitted to the left and right drive wheels 52 and 53 via the final ring gear 51 and the differential 50.

  The differential 50 is of a two-pinion type, and distributes and transmits the power input from the final ring gear 51 to the left and right drive wheels 52 and 53 as necessary. The final ring gear 51 of the differential 50 lifts up the oil in the transaxle case 3 as it rotates, and each part in the transaxle case 3 that requires lubrication or cooling (gear meshing portion, sliding contact portion, bearing, etc.) ).

  The oil pump 60 is a trochoid pump, and includes a drive rotor 61, a driven rotor 62, an oil pump cover 63, and the like. The oil pump 60 can be a gear pump or the like. The drive rotor 61 is coupled to the outer diameter side of the oil pump drive shaft 5 so as to be integrally rotatable. The driven rotor 62 is fixedly fixed to the transaxle case 3. The oil pump drive shaft 5 is coaxially connected to the inner end of the input shaft 4 so as to be integrally rotatable by, for example, spline fitting.

  As the operation of the oil pump 60, when the engine torque is transmitted to the input shaft 4 through the crankshaft 23 and the coil spring type damper 6, the oil pump drive shaft 5 that rotates synchronously with the input shaft 4 The drive rotor 61 is rotationally driven. In this way, when the drive rotor 61 is driven to rotate, the oil pump 60 sucks the oil enclosed in the transaxle case 3, and the sucked oil is inside the oil pump drive shaft 5 and the input shaft 4. Is discharged radially outward through an axial hole (reference numeral omitted) and a radial hole (reference numeral omitted). The released oil is supplied to, for example, the meshing part of the power split mechanism 30 and the reduction gear 40, the meshing part of the sun gears 31, 41, the pinion gears 33, 43, and the ring gears 32, 42, the sliding contact part, etc. These are supplied to the sliding contact portion in the transaxle case 3 and the radial bearings 26, 27, 28, 29, etc., and are used for lubrication, cooling and cleaning.

-Engine and motor generator operation control-
In the hybrid vehicle 2 configured as described above, a required torque to be output to the drive wheels 52 and 53 is calculated based on the accelerator opening and the vehicle speed corresponding to the depression amount of the accelerator pedal 83 by the driver. The engine 7, the motor generator MG1, and the motor generator MG2 are operated and controlled so that the required power corresponding to the required torque is output to the drive wheels 52 and 53.

  For example, the hybrid vehicle 2 stops the operation of the engine 7 and starts running (EV running) by controlling the power generation of the motor generator MG2 at the time of starting and running at a light load at a low vehicle speed.

  In addition, the hybrid vehicle 2 travels using the engine 7 as a main power source during steady traveling, etc., and regeneratively controls the motor generator MG1, and supplements the motor generator MG2 with electrical energy obtained by the regenerative control. Power running control.

  Furthermore, the hybrid vehicle 2 drives the engine 7 during acceleration, etc., and travels by driving the motor generator MG2 with the electric energy obtained by regenerative control of the motor generator MG1 and the electric energy of the battery 10. Do.

  In addition, when the hybrid vehicle 2 moves backward, the motor generator MG2 performs power running control in the reverse rotation direction with respect to when moving forward.

  On the other hand, in this hybrid vehicle 2, when the brake pedal 85 is depressed, a required braking force to be applied to the hybrid vehicle 2 is set based on the master cylinder pressure (braking force) and the vehicle speed, as shown in FIG. In addition, the brake actuator 92 and the motor generator MG2 are controlled so that the required braking force acts on the hybrid vehicle 2 through cooperation between the hydraulic brake and the regenerative brake. Specifically, the brake actuator 92 is controlled so that the braking torque according to the share of the hydraulic brake acts on the drive wheels 52 and 53 and the driven wheel, and the brake torque according to the share of the regenerative brake is applied to the drive wheel 52. , 53 to regeneratively control motor generator MG2. In the hybrid vehicle 2, the motor generator MG2 is regeneratively controlled even when the accelerator is off.

-Control during regeneration and power running of motor generator MG2-
By the way, since the helical gear is a gear that generates a thrust force in the axial direction when transmitting power, in the reduction mechanism 40 of the transaxle 1 described above, the sun gear 41 formed of a helical external gear is used. As a result of the meshing with the plurality of pinion gears 43 made of helical external gears, the sun gear 41 generates a thrust force in its axial direction (vehicle width direction). In particular, the transaxle 1 of the present embodiment causes the abutment surface 39a of the rotor shaft 36 of the motor generator MG2 to become the inner side of the radial bearing 28 on the engine 7 side by the meshing of gears in the reduction mechanism 40 during regeneration of the motor generator MG2. A thrust force acting so as to press against the race 28 a is generated in the rotor shaft 36.

  Here, the rotor shaft 36 and the inner race 28a basically rotate together, but a slight slip in the circumferential direction (rotation direction) may occur between them. In addition, raw materials are generally used for the rotor 22, whereas the inner race 28 a is usually quenched, so that the inner race 28 a has higher hardness than the rotor 22.

  Therefore, the abutting surface 39a of the rotor shaft 36 is pressed against the inner race 28a by the thrust force of the sun gear 41, and rotates while the abutting surface 39a and the inner race 28a are in contact with each other. If this occurs, the rotor shaft 36 having a lower hardness than the inner race 28a will be worn. Further, the progress of the wear of the rotor shaft 36 tends to be faster as the regenerative torque of the motor generator MG2 is larger.

  In order to solve such a problem, in order to prevent the rotor shaft 36 from being pressed against the inner race 28a, it is conceivable to provide a plate or the like for suppressing the movement of the rotor 22 due to the thrust force. If the is separately provided on the transaxle 1, there arises a problem that the cost increases and a problem that an installation space such as a plate must be secured.

  Therefore, in the hybrid vehicle 2 of the present embodiment, a new member such as a plate is not provided, but the progress of wear of the rotor shaft 36 is suppressed by operation control of the transaxle 1. Specifically, the ECU 70 generates a thrust force on the rotor shaft 36 that acts to press the contact surface 39a of the rotor shaft 36 against the inner race 28a due to the meshing of the gear in the reduction mechanism 40, that is, the motor At the time of regeneration of the generator MG2, the greater the regenerative torque of the motor generator MG2, the higher the frequency of performing the motor torque reduction control for reducing the regenerative torque as compared with the case where the regenerative torque is small.

  More specifically, when ECU 70 determines that the driving state of hybrid vehicle 2 is during regeneration of motor generator MG2 when brake pedal 85 is depressed, ECU 70 acquires a preset count value every predetermined time, Sum the acquired count values. Although motor generator MG2 regenerates not only when braking (when brake is on) but also when decelerating (when accelerator is off), it is difficult to generate a large regenerative torque at the time of regeneration when accelerator is off. In this embodiment, regeneration due to the accelerator being off is excluded from the control target.

  Here, ECU 70 weights the count value so that the greater the regenerative torque of motor generator MG2, the faster the progress of wear of rotor shaft 36, so that the operating point with a higher motor torque becomes heavier. It is configured as follows. Specifically, the ECU 70 refers to the map shown in FIG. 6 stored in the ROM 74 and detects which of the region A, the region B, and the region C has the operating point at a certain time. . Thus, the counter value is weighted in advance so as to increase in the order of region C → region B → region A, and the ECU 70 acquires a count value corresponding to the operating point at a certain time.

  For example, assuming that the counter value corresponding to the area A is 10, the counter value corresponding to the area B is 5, and the counter value corresponding to the area C is 1, the corresponding operating point is always obtained while the count value is acquired 10 times. If it is in the region A, the total value of the count values is 100, and if the corresponding operating point is always in the region C, the total value of the count values is 10. If the corresponding operation point is in the region A while the count value is acquired five times and then the corresponding operation point is moved to the region B, the total value of the count values can be obtained by acquiring the count value five more times. Becomes 75.

  Thus, the ECU 70 is configured to perform motor torque reduction control when the total value of the count values exceeds a predetermined value in one regeneration. Accordingly, the more the count value is acquired when the operating point is in the region where the motor torque is large, the more easily the total value of the count values becomes equal to or greater than the predetermined value. Therefore, the motor torque is increased as the regenerative torque of the motor generator MG2 is increased. The frequency of performing the reduction control is increased. Thereby, the progress of wear of the rotor shaft 36 during regeneration can be suppressed without providing a new member.

  On the other hand, when the regeneration is completed without the total value of the count values reaching the predetermined value, the ECU 70 resets the totaled count value without performing motor torque reduction control. As a result, when the regenerative torque of motor generator MG2 is small and the progress of wear of the rotor shaft is slow, the frequency of performing the motor torque reduction control is reduced, so that the regenerative energy can be recovered efficiently.

  Here, the motor torque reduction control for reducing the regenerative torque is to reduce the share of the regenerative brake in the required braking force acting on the hybrid vehicle 2 by the cooperation of the hydraulic brake and the regenerative brake by adjusting the hydraulic pressure. Realized. Specifically, the brake ECU 94 drives and controls the brake actuator 92 in accordance with a control signal from the ECU 70, adjusts the hydraulic pressure of the brake wheel cylinders 86 and 87, and increases the share of the hydraulic brake in the required braking force. It is realized with.

  When the motor generator MG2 is powered, a thrust force is generated so as to press the sun gear 41 against the inner race 28a. However, since the sun gear 41 is normally quenched similarly to the inner race 28a, Even if a slight slip occurs between the two in contact with each other, the wear of the sun gear 41 does not proceed.

  Thus, in the hybrid vehicle 2 of the present embodiment, the progress of wear of the rotor shaft 36 is suppressed during regeneration of the motor generator MG2, but the engine 7 is stopped during regeneration of the motor generator MG2. For this reason, the oil pump 60 does not operate and oil is not supplied to the radial bearing 28. If the contact surface 39a of the rotor shaft 36 and the inner race 28a are not lubricated with oil, the wear of the rotor shaft 36 may be accelerated.

  Here, if the motor generator MG2 is regenerated by depressing the brake pedal 85 from steady running or the like, the engine 7 is driven during steady running before regeneration, and therefore the oil pump 60 is activated. Therefore, regeneration of the motor generator MG2 is started in a state where the contact surface 39a of the rotor shaft 36 and the inner race 28a are lubricated with oil.

  However, when the motor generator MG2 is regenerated by depressing the brake pedal 85 from EV travel, the engine 7 is stopped during powering before regeneration, and therefore the oil pump 60 is not operating. There is a possibility that regeneration of the motor generator MG2 may be started in a state where the contact surface 39a of the rotor shaft 36 and the inner race 28a are not lubricated by oil.

  Therefore, in the hybrid vehicle 2 of this embodiment, the ECU 70 is configured to drive the engine 7 in preparation for the subsequent regeneration of the motor generator MG2 even when the motor generator MG2 is powered. Thus, by driving the engine 7 during the power running of the motor generator MG2, the oil pump 60 operates during the power running, so that oil is supplied to the contact surface 39a of the rotor shaft 36 and the inner race 28a. The contact surface 39a of the rotor shaft 36 is lubricated, cooled, and cleaned. Thereby, the progress of wear of the rotor shaft 36 can be suppressed during regeneration after power running.

  Next, an example of control according to the present embodiment will be described with reference to the flowchart of FIG.

  First, in step S1, ECU 70 determines whether or not motor generator MG2 is being regenerated when brake pedal 85 is depressed (during braking). Here, the ECU 70 determines the brake pedal position signal from the brake pedal position sensor 89, the accelerator opening signal from the accelerator pedal position sensor 84, the vehicle speed input from the vehicle speed sensor 88, and the motor generator MG2 calculated by the motor ECU 25. Whether the motor generator MG2 is regenerating or not is determined based on the rotational speed of the motor.

  If the determination in step S1 is NO, for example, during regeneration of the motor generator MG2 during deceleration (due to accelerator off), EV travel, steady travel, acceleration, reverse travel, etc. Proceed to step S10. On the other hand, if the determination in step S1 is YES, that is, if the motor generator MG2 is being regenerated during braking, the process proceeds to step S2.

  In the next step S2, the ECU 70 acquires a count value set in advance according to the operating point. More specifically, the ECU 70 refers to the map (see FIG. 6) stored in the ROM 74, and in which of the regions A, B, and C the operating point at the time of acquiring the count value is located. Is detected. Thus, the ECU 70 acquires a counter value set so as to increase in the order of the region C → the region B → the region A according to the region where the operating point exists.

  In the next step S3, the ECU 70 adds the newly acquired count value. More specifically, the ECU 70 acquires the count value every predetermined time. When the newly acquired count value is the second count value, the ECU 70 acquires the newly acquired count value in step S2. When the newly acquired count value is the nth (n is an integer of 3 or more) count value, the total value of the first to (n-1) th count values is added to the newly acquired count value. Add the acquired count value.

  Next, in step S4, the ECU 70 determines whether or not the total count value is equal to or greater than a predetermined value. If the determination in step S4 is NO, that is, if the total value of the count values is less than the predetermined value, the process proceeds to step S5, where it is determined whether regeneration of the motor generator MG2 is still continuing. If the determination in step S5 is YES, that is, if regeneration of the motor generator MG2 continues, the process returns to step S3 again, and the count value determined to be less than the predetermined value in step S4 is newly added. Is added to the acquired count value, and the process proceeds again to step S4. On the other hand, if the determination in step S5 is NO, that is, if regeneration of the motor generator MG2 has been completed, the process proceeds to step S6, the total value of the count values is reset (set to 0), and then the process proceeds to step S10. move on.

  On the other hand, if the determination in step S4 is YES, that is, if the total value of the count values is greater than or equal to a predetermined value, the process proceeds to step S7, where ECU 70 executes regenerative torque reduction control (motor torque reduction control) of motor generator MG2. To do.

  In this regenerative torque reduction control, the ECU 70 increases the braking torque (brake torque) for the share of the hydraulic brake in the required braking force, and decreases the braking torque (regeneration torque) for the share of the regenerative brake in the required braking force. Therefore, a control signal is transmitted to the brake ECU 94. The brake ECU 94 that has received the control signal from the ECU 70 controls the brake actuator 92 to adjust the hydraulic pressures of the brake wheel cylinders 86 and 87 so that the brake torque increases.

  In the next step S8, it is determined whether or not the regeneration of the motor generator MG2 is still continuing. If the determination in step S8 is YES, that is, if the regeneration of the motor generator MG2 is continuing, the process returns to step S7 and the execution of the regeneration torque reduction control is continued. On the other hand, if the determination in step S8 is NO, that is, if the regeneration of the motor generator MG2 has ended, the process proceeds to step S9, the total value of the count values is reset (set to 0), and then the process proceeds to step S10. move on.

  In step S6 and step S9, the total count value is reset for the following reason. That is, in the hybrid vehicle 2 of the present embodiment, a situation occurs in which the engine 7 is always driven (the oil pump 60 is operated) between the regeneration of the motor generator MG2 and the next regeneration, and the contact surface of the rotor shaft 36 This is because it is considered that the count value counted in the previous regeneration should not be taken over in the next regeneration because the new lubrication, cooling, and cleaning of 39a are performed.

  As described above, if it is determined in step S1 that the motor generator MG2 is not being regenerated during braking, or if it is determined in step S5 or step S8 that regeneration of the motor generator MG2 has been completed, step S10 is performed. Proceed to

  In step S10, ECU 70 determines whether or not motor generator MG2 is powering. If the determination in step S10 is YES, the process proceeds to step S11, and the ECU 70 dares to start the engine 7 even during the power running of the motor generator MG2 in preparation for the subsequent regeneration of the motor generator MG2. As a result, the oil pump 60 operates even during powering, so that oil is supplied to the contact surface 39a of the rotor shaft 36 and the inner race 28a, and the contact surface 39a is lubricated, cooled, and cleaned. The progress of wear of the rotor shaft 36 can be suppressed during regeneration after power running. On the other hand, if the determination in step S10 is NO, for example, during steady running or acceleration, the engine 7 is originally driven, and oil is supplied to the contact surface 39a of the rotor shaft 36 and the inner race 28a. Since lubrication, cooling, and cleaning of the contact surface 39a are performed, END is performed as it is.

(Other embodiments)
The present invention is not limited to the embodiments, and can be implemented in various other forms without departing from the spirit or main features thereof.

  In the above embodiment, the control device according to the present invention is applied to suppress the progress of the wear of the rotor shaft 36 in the motor generator MG2. However, the present invention is not limited to this, for example, by the meshing of gears in the power split mechanism 30. The control device according to the present invention can also be applied when wear of the rotor shaft 35 of the motor generator MG1 proceeds.

  In the above-described embodiment, the control device according to the present invention is a transaxle having a structure in which a thrust force is generated that acts to press the contact surface 39a of the rotor shaft 36 against the inner race 28a during regeneration of the motor generator MG2. However, the present invention is not limited to this, and may be applied to a transaxle having a structure in which a similar thrust force is generated when the motor generator MG2 is not regenerating.

  Furthermore, in the above-described embodiment, regeneration due to accelerator off is excluded from the control target. However, the present invention is not limited to this, and regeneration due to accelerator off may be the control target.

  In the above embodiment, when the total value of the count values is equal to or greater than the predetermined value, the motor torque reduction control of the motor generator MG2 is executed. However, the present invention is not limited to this. For example, the count acquired from the predetermined value The motor torque reduction control of the motor generator MG2 may be executed when the value is subtracted and the subtracted value becomes negative.

  Furthermore, in the said embodiment, although the control apparatus which concerns on this invention was applied to the hybrid vehicle 2, it is not restricted to this, For example, about regenerative torque reduction control, you may apply to EV vehicle.

  In the above embodiment, the control device according to the present invention is applied to the transaxle 1 in which the rotor shaft 36 is connected to the sun gear 41 of the planetary gear mechanism 40. However, the rotor shaft 36 is used as a bearing race by the meshing of the gears. The present invention is not limited to this as long as a thrust force acting so as to be pressed is generated, and the control device according to the present invention is applied to the transaxle 1 in which the rotor shaft 36 is connected to a gear different from the sun gear 41. Also good. Further, the gear mechanism is not limited to the planetary gear mechanism as long as it has a structure that generates a thrust force that presses the rotor shaft 36 against the bearing race by the meshing of the gears.

  As described above, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  According to the present invention, as the motor torque of the motor generator increases, it becomes easier to reduce the motor torque as compared with the case where the motor torque is small. Therefore, the progress of wear of the rotor shaft is suppressed without providing a new member. Therefore, the present invention is extremely useful when applied to a control device for a power transmission device in which a rotor of a motor generator is connected to a gear mechanism.

1 Transaxle (power transmission device)
2 Hybrid vehicle 7 Engine 15 Battery ECU (control means)
24 engine ECU (control means)
25 Motor ECU (control means)
28 Radial bearing 28a Inner race (bearing race)
36 rotor shaft 37 first supported portion (supported portion)
39 Diameter-expanded part (part where the opposing surface is formed)
39a Contact surface (opposite surface)
40 Reduction mechanism (gear mechanism)
60 Oil pump 70 ECU (control means)
85 Brake pedal 94 Brake ECU (control means)
MG2 motor generator

Claims (5)

A control device for a power transmission device having a bearing that rotatably supports a rotor shaft of a motor generator, wherein the rotor shaft is coupled to a gear mechanism,
Control means for performing motor torque reduction control for reducing the motor torque of the motor generator,
In addition to the portion supported by the bearing, the rotor shaft has a portion where a bearing race of the bearing and a facing surface facing the rotor axial direction are formed.
When the thrust force that acts to press the opposed surface against the bearing race is generated in the rotor shaft due to the meshing of the gear in the gear mechanism, the control means increases the motor torque of the motor generator. A control device for a power transmission device, characterized in that the motor torque reduction control is performed more frequently than when the motor torque is small. In the control device of the power transmission device according to claim 1,
The power transmission device has a structure in which the thrust force is generated during regeneration of the motor generator,
The control means is configured to increase the frequency at which the motor torque reduction control is performed as the regenerative torque of the motor generator is larger than when the regenerative torque is small. Control device. In the control device for the power transmission device according to claim 2,
The control means increases the frequency of performing the motor torque reduction control when the motor generator is regenerated when the brake pedal is operated, as the regenerative torque of the motor generator is larger than when the regenerative torque is small. Is configured as
The motor torque reduction control is executed by adjusting a brake pressure. In the control device for a power transmission device according to claim 2 or 3,
The power transmission device is further driven by the rotational output of the engine and further includes an oil pump that supplies oil to the bearing.
The control device for a power transmission device, wherein the control means is configured to drive the engine when the motor generator is powered. In the control device for a power transmission device according to any one of claims 2 to 4,
The control means is configured to acquire a count value every predetermined time during regeneration of the motor generator, and to perform the motor torque reduction control when a total value of the acquired count values becomes equal to or greater than a predetermined value. And a control device for the power transmission device, wherein the count value is weighted so that the weight of the operating point with a larger motor torque becomes heavier.

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