JP2006211740A - Drive unit and automobile mounted with the same, and control method of drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a torque shock that may be generated when switching a variable shift of a change gear, in a device whose drive shaft is connected, via the change gear, to a motor whose maximum power to be outputted is lowered when the number of revolutions of the motor is increased. <P>SOLUTION: Gear states of the change gear are switched with a vehicle speed Vm as a reference, in which maximum torque from the motor that acts on the drive shaft when the change gear is in a Lo-gear state, and maximum torque from the motor that acts on the drive shaft when the change gear is in a Hi-state, coincide with each other. By this, even if the gear states are switched, the shock that may be generated when switching the gear states of the change gear, is suppressed while outputting the maximum torque from the motor MG3 whose maximum power to be outputted is lowered as the number of revolutions of the motor is increased. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive device, an automobile equipped with the drive device, and a method for controlling the drive device.

Conventionally, this type of drive device is a device that is mounted on an automobile together with a power output device that outputs power from an engine to the front wheel side via a transmission. What outputs to the ring | wheel side is proposed (for example, refer patent document 1). In this device, the motor is prevented from over-rotating by reducing the reduction ratio of the transmission as the vehicle speed increases.
JP-A-11-240351

  If a motor that reduces the maximum output power (for example, a synchronous reluctance motor) is used as a motor of such a drive device, a torque shock may occur when shifting the transmission. Since the maximum power that can be output from the motor decreases as the rotation speed increases, if the motor speed changes as the transmission shifts, the maximum power that can be output from the motor changes abruptly and this is output to the rear wheels. Torque shock occurs.

  The drive device according to the present invention, the vehicle equipped with the drive device, and the drive device control method include a gear shifter in a device in which an electric motor having a maximum output power that decreases as the rotational speed increases is output to the drive shaft via the transmission. One of the purposes is to suppress a torque shock that may occur when the stage is switched. In addition, the drive device of the present invention, the automobile equipped with the drive device, and the drive device control method include: a transmission in a device in which an electric motor whose maximum output power decreases as the rotational speed increases is output to the drive shaft via the transmission; One of the purposes is to smoothly switch the gears.

  In order to achieve at least a part of the above-described object, the drive device, the automobile equipped with the drive device, and the drive device control method of the present invention employ the following means.

The drive device of the present invention is
A drive device for driving a drive shaft,
An electric motor in which the maximum power that can be output decreases as the rotational speed increases;
Shift transmission means for shifting and transmitting power between the rotating shaft of the electric motor and the drive shaft with at least two shift stages;
The speed change is based on the coincidence rotation speed, which is the rotation speed of the drive shaft with which the maximum power output from the electric motor to the drive shaft through the shift transmission means before and after the shift stage of the shift transmission means is switched. Shift control means for controlling the shift transmission means so that the gear position of the transmission means is switched;
It is a summary to provide.

  In the drive device of the present invention, the maximum transmission power that can be output decreases as the rotational speed increases, and transmission is performed by shifting the power with at least two speeds between the rotation shaft of the motor and the drive shaft. The shift speed of the means is switched on the basis of the coincidence rotation speed, which is the rotation speed of the drive shaft with which the maximum power output from the electric motor to the drive shaft via the shift transmission means before and after the shift speed switching. Thereby, even if the shift stage of the shift transmission means is switched while outputting the maximum power from the electric motor, it is possible to suppress a torque shock that may occur when the shift stage is switched. As a result, it is possible to smoothly switch the shift speed of the shift transmission means. Here, as the electric motor, for example, a synchronous reluctance motor can be used.

  In such a driving apparatus of the present invention, the shift control means is a means for controlling the shift of the shift transmission means to be substantially finished at the coincidence rotational speed when the electric motor is driven at the maximum power. It can also be. By so doing, it is possible to effectively suppress torque shock that may occur when the shift stage of the shift transmission means is switched while outputting the maximum power from the electric motor.

  The drive device of the present invention further includes a rotation speed detection means for detecting the rotation speed of the drive shaft, and the shift control means is configured to switch the shift speed of the shift transmission means from the low speed side to the high speed stage. Controlling the shift transmission means so that the shift stage is switched when the detected rotation speed increases and reaches a first low-high switching speed that is smaller than the coincidence rotation speed, and the shift stage is switched, When the shift speed of the shift transmission means is switched from the high speed side to the low speed side, the detected speed is reduced and the shift is started when the first high / low switching speed greater than the coincidence speed is reached. Thus, the shift transmission means can be controlled so that the gear position can be switched. By doing so, the switching of the gear position of the transmission means can be completed in the vicinity of the coincidence rotational speed. In this case, it is possible to provide a switching speed setting means for setting the first low / high switching speed and the first high / low switching speed based on the detected change in the rotational speed. By so doing, it is possible to complete the switching of the gear position of the transmission transmission means at a rotational speed closer to the coincident rotational speed.

  Further, in the driving apparatus of the present invention, the shift control means is detected after the detected rotation speed increases and reaches the first low-high switching rotation speed and the shift speed of the shift transmission means is switched. When the detected rotational speed decreases before reaching the first rotational speed equal to or higher than the first high / low switching rotational speed, the detected rotational speed reaches a second high / low switching rotational speed that is smaller than the first low / high switching rotational speed. The shift transmission means is controlled so that the gear position of the shift transmission means is switched to the low speed stage side, and the detected rotation speed decreases to reach the first high / low switching rotation speed, so that the shift speed of the shift transmission means is reached. When the detected rotational speed increases before reaching the second rotational speed equal to or lower than the first low-high switching rotational speed after the engine is switched, the detected rotational speed is larger than the first high-low switching rotational speed. 2 Low-high switching rotation Gear position of the transmission mechanism can also be assumed to be a means for controlling the speed change transmission means to be switched to the high speed stage side when reached. In this way, it is possible to suppress frequent changes in the gear position in a short time and maintain the state where the speed is switched to the high speed side even though the rotational speed of the drive shaft is reduced, Even when the rotational speed of the drive shaft is increased, it is possible to avoid maintaining the state of being switched to the low speed stage side.

  The automobile of the present invention is the driving apparatus of the present invention according to any one of the above-described aspects, that is, basically a driving apparatus that drives the driving shaft, and the maximum power that can be output as the rotational speed increases. A lowering motor, shift transmission means for shifting and transmitting power between the rotating shaft of the motor and the drive shaft with at least two shift stages, and before and after switching of the shift stage of the shift transmission means The shift transmission means so that the shift stage of the shift transmission means is switched on the basis of the coincidence rotation speed that is the rotation speed of the drive shaft with which the maximum power output from the electric motor to the drive shaft via the shift transmission means coincides. And a shift control means for controlling the vehicle. The gist is that the axle is connected to the drive shaft.

  In this automobile of the present invention, the drive device of the present invention according to any one of the above-described aspects is mounted. Therefore, the effects exhibited by the drive device of the present invention, for example, the gear stage of the shift transmission means while outputting the maximum power from the electric motor. Even if the switching is performed, it is possible to achieve the same effects as the effect of suppressing the torque shock that may occur when switching the gear position and the effect of smoothly switching the gear position of the gear transmission means.

  In such an automobile of the present invention, a power output device capable of outputting traveling power to the axle or an axle different from the axle may be mounted. Further, the shift control means may be a means for controlling using the vehicle speed instead of the rotational speed of the drive shaft.

The method for controlling the drive device of the present invention includes:
A motor in which the maximum power that can be output decreases as the number of rotations increases, and transmission transmission means that shifts and transmits power between the rotating shaft and the drive shaft of the motor with at least two or more shift stages; A method for controlling a drive device comprising:
The speed change is based on the coincidence rotation speed, which is the rotation speed of the drive shaft with which the maximum power output from the electric motor to the drive shaft through the shift transmission means before and after switching the shift speed of the shift transmission means. The gist is to control the transmission means so that the gear position of the transmission means can be switched.

  In the control method of the drive device of the present invention, the maximum power that can be output decreases as the rotational speed increases, and the power is shifted and transmitted between the rotation shaft of the motor and the drive shaft with at least two shift stages. The shift speed of the shift transmission means is switched based on the coincidence rotation speed, which is the rotation speed of the drive shaft that matches the maximum power output from the electric motor to the drive shaft before and after the shift speed switching. . Thereby, even if the shift stage of the shift transmission means is switched while outputting the maximum power from the electric motor, it is possible to suppress a torque shock that may occur when switching the shift stage. As a result, it is possible to smoothly switch the shift speed of the shift transmission means. Here, as the electric motor, for example, a synchronous reluctance motor can be used.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As illustrated, the hybrid vehicle 20 of the embodiment includes a front wheel drive device 21 that drives the front wheels 39a and 39b, a rear wheel drive device 41 that drives the rear wheels 39c and 39d, a front wheel drive device 21 and a rear wheel drive device. The battery 50 which exchanges electric power with 41, and the electronic control unit 70 which controls the whole vehicle are provided.

  The front wheel drive device 21 has a ring gear connected to an engine 22 that outputs power using hydrocarbon fuel such as gasoline, a carrier connected to the crankshaft of the engine 22 and a drive shaft 28 connected to the front wheels 39a and 39b. The planetary gear 30, the motor MG 1 connected to the sun gear of the planetary gear 30 and exchanging electric power with the battery 50 via the inverter 25, and exchanging electric power with the battery 50 via the inverter 26 and driving power to the drive shaft 28. And a front wheel drive electronic control unit (hereinafter referred to as a front wheel drive ECU) 24 for controlling the front wheel drive device 21. The front-wheel drive device 21 converts the torque from the engine 22 by the planetary gear 30 and the two motors MG1 and MG2 with the charging and discharging of the battery 50 and outputs the torque to the drive shaft 28. The front wheel drive ECU 24 communicates with the electronic control unit 70 and transmits information regarding the front wheel drive device 21 to the electronic control unit 70 as necessary.

  The rear wheel drive device 41 has a synchronous reluctance motor (hereinafter abbreviated as a motor) MG3 in which the maximum power that can be output decreases as the rotational speed increases, and the power of the motor MG3 is shifted in two stages to rear wheel 39c. , 39d, a transmission 60 that is transmitted to the drive shaft 46, and a motor MG3 through the inverter 42, and a rear wheel drive electronic control unit for controlling the transmission 60 (hereinafter, rear wheel drive). ECU) 44). The transmission 60 includes two planetary gears (not shown) and two brakes that can fix two of the rotating elements to the case, respectively. By combining the on and off of the two brakes, the transmission 60 has a relatively large reduction ratio. A state in which the power of the motor MG3 is transmitted to the drive shaft 46 (hereinafter referred to as Lo gear state), a state in which the power is transmitted at a smaller reduction ratio (hereinafter referred to as Hi gear state), and a drive shaft 46 of the motor MG3. Toggles the state of disconnection from the. If both brakes are turned on, the rotation shaft of the motor MG3 and the drive shaft 46 can be fixed to the case. The rear wheel drive ECU 44 communicates with the electronic control unit 70 and transmits information regarding the rear wheel drive device 41 to the electronic control unit 70 as necessary.

  The electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and a communication port (not shown), Is provided. The electronic control unit 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator opening Acc, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the electronic control unit 70 transmits and receives various control signals and data to and from the front wheel drive ECU 24 and the rear wheel drive ECU 44 via the communication port.

  The hybrid vehicle 20 configured in this manner travels with power from only the front wheel drive device 21 or travels with power from only the rear wheel drive device 41 in accordance with the driver's operation and environmental conditions such as road gradient. The vehicle travels by four wheels by power from both the front wheel drive device 21 and the rear wheel drive device 41. Note that the switching of the driving mode and the distribution of power to the front and rear wheels during four-wheel drive driving do not form the core of the present invention, and thus detailed description thereof is omitted.

  Next, switching of the gear state of the transmission 60 will be described. FIG. 2 is an explanatory diagram showing an example of the relationship between the maximum torque output from the motor MG3 to the drive shaft 46 via the transmission 60 and the gear state of the transmission 60. In the drawing, the broken line A indicates the maximum torque output to the drive shaft 46 when in the Lo gear state, the broken line B indicates the maximum torque output to the drive shaft 46 when in the Hi gear state, and the broken line C shows an equal power curve. Since the motor MG3 is a synchronous reluctance motor in which the maximum power that can be output decreases as the rotational speed increases, the maximum power decreases as the vehicle speed V increases as indicated by the broken solid line A and the broken solid line B. Thus, when the transmission 60 is in the Lo gear state, the maximum torque when the transmission 60 is in the Lo gear state and the maximum speed when the transmission 60 is in the Hi gear state are greater than the vehicle speed Vm. The maximum torque is smaller than the maximum torque when the transmission 60 is in the Hi gear state. Therefore, when the transmission 60 is switched from the Lo gear state to the Hi gear state after the vehicle speed V exceeds the vehicle speed Vm while the maximum torque is being output from the motor MG3, the torque output to the drive shaft 46 is Hi. When it is switched to gear, it increases rapidly and gives a torque shock to the driver. In order to switch the transmission 60 from the Lo gear state to the Hi gear state without causing such a torque shock, the gear state may be switched when the vehicle speed V is the vehicle speed Vm. In general, a stepped transmission requires a certain amount of time for shifting. Therefore, when the vehicle speed V is the vehicle speed Vm, in order to end the switching of the gear state, the shifting is performed at a vehicle speed Vl1 smaller than the vehicle speed Vm at which the shifting is started. Just start. The vehicle speed Vl1 can be determined such that, for example, when a single passenger is accelerating on a flat road with maximum acceleration, the switching of the gear state of the transmission 60 is completed at just the vehicle speed Vm. Thus, when the vehicle speed Vl1 for switching from the Lo gear state to the Hi gear state is determined, the switching from the Hi gear state to the Lo gear state becomes a vehicle speed lower than the vehicle speed Vl1 in consideration of hunting, In consideration of acceleration performance at high speed, it is preferable to switch to the Lo gear state as soon as possible. Therefore, the vehicle speed Vh1 is determined so that the vehicle speed for switching from the Hi gear state to the Lo gear state is symmetrical to the vehicle speed Vl1 for switching from the Lo gear state to the Hi gear state across the vehicle speed Vm. Now, when the driver depresses the accelerator pedal 83 greatly, the vehicle speed V exceeds the vehicle speed V11 while outputting the maximum torque from the motor MG3, and the transmission 60 is switched from the Lo gear state to the Hi gear state. Consider the case where the accelerator pedal 83 is returned before the vehicle speed V reaches the vehicle speed Vh1 and the vehicle speed V decreases. At this time, since the transmission 60 is maintained in the Hi gear state even when the vehicle speed V is less than the vehicle speed Vl1, it is necessary to switch the gear state of the transmission 60 to the Lo gear state. In order to prevent frequent switching from the Hi gear state to the Lo gear state as opposed to switching from the Lo gear state to the Hi gear state, the Hi gear state is changed to the Lo gear state. The vehicle speed V to be switched may be set to a vehicle speed Vl2 smaller than the vehicle speed Vl1. At this time, if a torque close to the maximum torque is output from the motor MG3, a torque shock occurs when switching from the Hi gear state to the Lo gear state, but when the vehicle speed V decreases in this way, the accelerator pedal 83 becomes large. Since the motor MG3 is not depressed, only a relatively small torque is output from the motor MG3, and no torque shock occurs when switching from the Hi gear state to the Lo gear state. Next, the driver returns the accelerator pedal 83 or depresses the brake pedal 85 while the transmission 60 is operating at high speed in the Hi gear state, so that the vehicle speed V falls below the vehicle speed Vh1 and the transmission 60 becomes Hi. A case will be considered in which the state is switched from the gear state to the Lo gear state, and immediately after that, before the vehicle speed V reaches the vehicle speed Vl1, the accelerator pedal 83 is depressed to increase the vehicle speed V. At this time, since the transmission 60 is maintained in the Lo gear state even when the vehicle speed V becomes equal to or higher than the vehicle speed Vh1, it is necessary to switch the gear state of the transmission 60 to the Hi gear state. In order to prevent frequent switching from the Lo gear state to the Hi gear state as opposed to switching from the Hi gear state to the Lo gear state, the Lo gear state is changed to the Hi gear state. The vehicle speed V to be switched may be set to a vehicle speed Vh2 larger than the vehicle speed Vh1. At this time, since the driver depresses the accelerator pedal 83, a relatively large torque is output from the motor MG3, and a torque shock occurs when switching from the Lo gear state to the Hi gear state. However, this torque shock is masked by the behavior associated with the transition of the vehicle from the deceleration state to the acceleration state, and thus does not cause a great sense of discomfort to the driver.

  As can be understood from the above description, the gear state of the transmission 60 is switched from the Lo gear state to the Hi gear state at the vehicle speed V11 during acceleration, and from the Hi gear state to the Lo gear state at the vehicle speed Vh1 during deceleration. What is necessary is just to switch to the state of a gear. In addition, when the vehicle speed V decreases before reaching the vehicle speed Vh1 after switching from the Lo gear state to the Hi gear state at the vehicle speed Vl1, the Hi gear state is changed from the Hi gear state to the vehicle speed Vl2 that is smaller than the vehicle speed Vl1. When the vehicle speed V increases before reaching the vehicle speed Vl1 after switching from the Hi gear state to the Lo gear state at the vehicle speed Vh1, from the Lo gear state at a vehicle speed Vh2 greater than the vehicle speed Vh1. Switching to the Hi gear state may be performed. Here, after switching from the Lo gear state to the Hi gear state at the vehicle speed Vl1, the state in which the vehicle speed V falls within the range of the vehicle speed Vl2 to the vehicle speed Vh2 is a transition state from the Lo gear state to the Hi gear state. (Hereinafter referred to as the Lo-Hi transition state), and the vehicle speed V falls within the range from the vehicle speed Vl2 to the vehicle speed Vh2 after switching from the Hi gear state to the Lo gear state at the vehicle speed Vh1. If the state is defined as a transition state from the Hi gear state to the Lo gear state (hereinafter referred to as a Hi-Lo transition state), the transmission 60 passes from the Lo gear state through the Lo-Hi transition state. It can be said that the state is switched to the Hi gear state and switched from the Hi gear state to the Lo gear state through the Hi-Lo transition state. FIG. 3 shows an example of this as a shift process routine executed by the rear wheel drive ECU 44 in the flowchart. Hereinafter, the shift process routine will be briefly described.

When the shift process routine is executed, the rear wheel drive ECU 44 first inputs data necessary for control such as the vehicle speed V from the vehicle speed sensor 88, state flags Fh and Fl, and the gear state Gs of the transmission 60 (step). S100). Here, the state flag Fh is a state before the vehicle speed V reaches the vehicle speed Vh1 after being switched from the Lo gear state to the Hi gear state at the vehicle speed Vl1 (in the embodiment, the vehicle speed V has not reached the vehicle speed Vh2). ), That is, a flag indicating whether or not the Lo-Hi transition state is set. The value 1 is set by this routine when the Lo-Hi transition state is set, and the value 0 is set by the routine when the Lo-Hi transition state is not set. Is done. The state flag Fl is a state before the vehicle speed V reaches the vehicle speed Vl1 after being switched from the Hi gear state to the Lo gear state at the vehicle speed Vh1 (in the embodiment, the vehicle speed V has not reached the vehicle speed Vl2). That is,
This is a flag indicating whether or not it is in the Hi-Lo transition state. The value 1 is set by this routine when it is in the Hi-Lo transition state, and the value 0 is set when it is not in the Hi-Lo transition state. The gear state Gs of the transmission 60 is set when the gear state of the transmission 60 is switched from this routine.

  When the data is input in this way, the gear state Gs of the transmission 60 is determined (step S110), and when it is in the Lo gear state, the state flag Fl is checked (step S200). When the state flag Fl is 0, when this routine was executed last time, it was determined that the vehicle speed V was not in the Hi-Lo transition state and the vehicle speed V was less than the vehicle speed Vl2 and did not reach the vehicle speed Vl1. The vehicle speed V is compared with the vehicle speed Vl1 (step S210). When the vehicle speed V has not reached the vehicle speed Vl1, it is determined that the gear state does not need to be switched, and this routine ends. When the vehicle speed V reaches the vehicle speed Vl1, the Lo gear state is switched to the Hi gear state, and the Hi gear state is set to the gear state Gs of the transmission 60 (step S220), and the Lo-Hi transition state is reached. The value 1 is set to the status flag Fh (step S230), and this routine is terminated.

  When the Hi gear state is set in the gear state Gs of the transmission 60 and the value 1 is set in the state flag Fh, it is determined in Step S110 that the state is the Hi gear state, and in Step S300, the state flag Fh is set to the value 1. And is determined to be in the Lo-Hi transition state. At this time, it is determined whether or not the vehicle speed V is in a range between the vehicle speed Vl2 and the vehicle speed Vh2 (step S340). When the vehicle speed V is in the range between the vehicle speed Vl2 and the vehicle speed Vh2, it is determined that the Lo-Hi transition state is still present and it is not necessary to switch the gear state, and this routine is terminated. When the vehicle speed V is equal to or higher than the vehicle speed Vh2, it is determined that the Lo-Hi transition state has been exceeded, a value 0 is set in the state flag Fh (step S350), and this routine is terminated. When the vehicle speed V is less than or equal to the vehicle speed Vl2, it is determined that the Lo-Hi transition state has returned to the Lo gear state, the transmission 60 is switched from the Hi gear state to the Lo gear state, and the gear state Gs of the transmission 60 is obtained. Is set to the state of the Lo gear (step S360), the value 0 is set to the state flag Fh (step S370), and this routine is terminated.

  When the transmission 60 is switched to the Hi gear state and exceeds the Lo-Hi transition state, the state flag Fh is determined to be 0 in step S300. At this time, the vehicle speed V is compared with the vehicle speed Vh1 (step S310). When the vehicle speed V is greater than the vehicle speed Vh1, it is determined that the gear state is not changed, and this routine is terminated. When the vehicle speed V reaches the vehicle speed Vh1 or less, the transmission 60 is switched from the Hi gear state to the Lo gear state, and the Lo gear state is set to the gear state Gs of the transmission 60 (step S320), Hi-Lo. Since the transition state has been reached, the value 1 is set to the state flag Fl (step S330), and this routine is terminated.

  When the Lo gear state is set in the gear state Gs of the transmission 60 and the value 1 is set in the state flag Fl, it is determined in Step S110 that the state is the Lo gear state. In Step S200, the state flag Fl is set to the value 1. And is determined to be in the Hi-Lo transition state. At this time, it is determined whether or not the vehicle speed V is in a range between the vehicle speed Vl2 and the vehicle speed Vh2 (step S240). When the vehicle speed V is in the range between the vehicle speed Vl2 and the vehicle speed Vh2, it is determined that the state is still in the Hi-Lo transition state and switching of the gear state is not necessary, and this routine is terminated. When the vehicle speed V is less than or equal to the vehicle speed Vl2, it is determined that the Hi-Lo transition state has been exceeded, a value 0 is set in the state flag Fl (step S250), and this routine is terminated. When the vehicle speed V is equal to or higher than the vehicle speed Vh2, it is determined that the Hi-Lo transition state has returned to the Hi gear state, the transmission 60 is switched from the Lo gear state to the Hi gear state, and the gear state Gs of the transmission 60 is obtained. Is set to the state of the Hi gear (step S260), the value 0 is set to the state flag Fl (step S270), and this routine is terminated.

  According to the hybrid vehicle 20 of the embodiment described above, shifting is performed with reference to the vehicle speed Vm at which the maximum torque when the transmission 60 is in the Lo gear state matches the maximum torque when the transmission 60 is in the Hi gear state. Since the gear state of the transmission 60 is switched, even if the gear state of the transmission 60 is switched while outputting the maximum torque from the motor MG3 in which the maximum power that can be output decreases as the rotational speed increases, the transmission 60 Torque shock that may occur when the gear state is switched can be suppressed. In addition, since the switching of the gear state of the transmission 60 is started at the vehicle speed Vl1 or the vehicle speed Vh2 so that the switching of the gear state of the transmission 60 is completed at the vehicle speed Vm, the gear state of the transmission 60 is switched. Torque shock that may occur is further suppressed. In addition, since the gear state of the transmission 60 is switched in consideration of the Lo-Hi transition state and the Hi-Lo transition state, frequent switching of the gear state of the transmission 60 can be suppressed. At the same time, it is possible to prevent the transmission 60 from being maintained in the Hi gear state even when the vehicle speed V has decreased, or to maintain the transmission 60 in the Lo gear state even though the vehicle speed V has increased.

  In the embodiment, the Lo-Hi transition state is defined as a state in which the vehicle speed V falls within the range from the vehicle speed Vl2 to the vehicle speed Vh2 after switching from the Lo gear state to the Hi gear state at the vehicle speed Vl1, but the vehicle speed Vl1. Therefore, the upper limit of this range may be any vehicle speed that is greater than the vehicle speed Vh1 after the vehicle speed V exceeds the vehicle speed Vh1 after switching from the Lo gear state to the Hi gear state. It may be used. Further, although the Hi-Lo transition state is defined as a state in which the vehicle speed V falls within the range of the vehicle speed Vl2 to the vehicle speed Vh2 after switching from the Hi gear state to the Lo gear state at the vehicle speed Vh1, the Hi-Lo transition state is defined as Hi. Since the vehicle speed V should be within the range until the vehicle speed V falls below the vehicle speed Vl1 after switching from the gear state to the Lo gear state, the lower limit of this range is any vehicle speed that is less than the vehicle speed Vl1. It is good.

  In the hybrid vehicle 20 of the embodiment, the vehicle speed Vl1 is determined so that the switching of the gear state of the transmission 60 is completed at just the vehicle speed Vm when a single passenger is accelerating at a maximum acceleration on a flat road. However, when the vehicle speed or acceleration is detected and the vehicle speed Vl1 is determined as the vehicle speed Vl1 based on the vehicle speed or acceleration, the vehicle speed Vm at which the switching of the gear state of the transmission 60 is completed is reached. Switching of the gear state of the transmission 60 may be started. By so doing, it is possible to further suppress torque shock that may occur when the gear state of the transmission 60 is switched.

  In the hybrid vehicle 20 of the embodiment, a synchronous reluctance motor is used as the motor MG3. However, any motor may be used as the motor MG3 as long as the maximum power that can be output decreases as the rotational speed increases. .

  In the hybrid vehicle 20 of the embodiment, the transmission 60 is configured as a two-stage stepped transmission in the Lo gear state and the Hi gear state. However, the transmission 60 is assumed to use a stepped transmission of three or more stages. Also good.

  In the hybrid vehicle 20 of the embodiment, the front wheel drive device 21 including the engine 22, the planetary gear 30, and the two motors MG1 and MG2 is mounted. However, the front wheel drive device 21 can output power to the front wheel side. Any drive device or power output device may be used if possible. Further, since the rear wheel drive device 41 may be mounted, the vehicle may not be equipped with the front wheel drive device 21.

  In the hybrid vehicle 20 of the embodiment, a front wheel drive device 21 including an engine 22, a planetary gear 30, and two motors MG1 and MG2 is connected to front wheels 39a and 39b, and a rear wheel drive device 41 including a motor MG3 and a transmission 60 is provided. The front wheel drive device 21 may be connected to the rear wheels 39c and 39d and the rear wheel drive device 41 may be connected to the front wheels 39a and 39b. .

  In the embodiment, the driving device including the motor MG3 and the transmission 60 is mounted on the automobile. However, the driving apparatus may be mounted on a moving body such as a vehicle other than the automobile, a ship, and an aircraft, or may be incorporated in equipment. It may be a thing. In this case, the gear state of the transmission 60 may be switched using the rotation speed of the drive shaft 46 instead of the vehicle speed V. That is, the gear state of the transmission 60 is switched using the rotational speeds Nl1, Nl2, Nh1, Nh2 of the drive shaft 46 corresponding to the vehicle speeds Vl1, Vl2, Vh1, Vh2.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention can be used in the manufacturing industry of driving devices and automobiles equipped with the same.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. FIG. 6 is an explanatory diagram showing an example of the relationship between the maximum torque output from the motor MG3 to the drive shaft 46 via the transmission 60 and the gear state of the transmission 60. It is a flowchart which shows an example of the shift process routine performed by the rear-wheel drive ECU44 of an Example.

Explanation of symbols

20 hybrid vehicle, 21 front wheel drive device, 22 engine, 24 engine ECU, 25 drive shaft, 30 power distribution and integration mechanism, 39a, 39b front wheel, 39c, 39d rear wheel, 41 rear wheel drive device, 42 inverter, 43 rotational position detection Sensor, 44 Rear wheel drive ECU, 46 Drive shaft, 50 Battery, 70 Electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position Sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, MG1, MG2 motor, MG3 synchronous reluctance motor (motor).

Claims (10)

A drive device for driving a drive shaft,
An electric motor in which the maximum power that can be output decreases as the rotational speed increases;
Shift transmission means for shifting and transmitting power between the rotating shaft of the electric motor and the drive shaft with at least two shift stages;
The speed change is based on the coincidence rotation speed, which is the rotation speed of the drive shaft with which the maximum power output from the electric motor to the drive shaft through the shift transmission means before and after the shift stage of the shift transmission means is switched. Shift control means for controlling the shift transmission means so that the gear position of the transmission means is switched;
A drive device comprising:   2. The drive device according to claim 1, wherein the shift control means is a means for controlling the shift of the shift transmission means to be substantially finished at the coincidence rotational speed when the electric motor is driven at maximum power. The drive device according to claim 1 or 2,
A rotation speed detecting means for detecting the rotation speed of the drive shaft;
When the shift control means switches the shift speed of the shift transmission means from the low speed side to the high speed side, the detected rotational speed increases and reaches a first low-high switching rotational speed smaller than the coincident rotational speed. The shift transmission means is controlled so that the shift stage is switched when the shift stage is started, and the detected rotational speed decreases when the shift stage of the shift transmission means is switched from the high speed stage side to the low speed stage side. Then, when the first high / low switching speed greater than the coincidence rotational speed is reached, the shift transmission means is controlled so that the shift stage is switched and the shift stage is switched.   4. The drive device according to claim 3, further comprising switching speed setting means for setting the first low / high switching speed and / or the first high / low switching speed based on the detected change in the rotational speed.   The shift control means increases the detected rotational speed to reach the first low / high switching rotational speed, and the detected rotational speed is switched to the first high / low switching speed after the shift stage of the shift transmission means is switched. When the detected rotational speed reaches a second high / low switching rotational speed that is smaller than the first low / high switching rotational speed when the rotational speed decreases before reaching the first rotational speed that is equal to or higher than the rotational speed, the shift stage of the shift transmission means The shift transmission means is controlled so as to be switched to the low speed stage side, and the detected speed is reduced and reaches the first high / low switching speed to change the speed stage of the shift transmission means. When the rotational speed increases before reaching the second rotational speed equal to or lower than the first low / high switching rotational speed, the detected rotational speed reaches a second low / high switching rotational speed that is greater than the first high / low switching rotational speed. Sometimes the shift transmission means Speed stage driving apparatus according to claim 3 is a means for controlling the speed change transmission means to be switched to the high speed stage side.   6. The driving apparatus according to claim 1, wherein the electric motor is a synchronous reluctance motor.   An automobile comprising the drive device according to any one of claims 1 to 6 and an axle connected to the drive shaft.   The automobile according to claim 7, wherein a power output device capable of outputting power for traveling is mounted on the axle or an axle different from the axle.   The automobile according to claim 7 or 8, wherein the shift control means is a means for controlling by using a vehicle speed instead of the rotational speed of the drive shaft. An electric motor whose maximum power that can be output decreases as the number of rotations increases, and a transmission transmission means that shifts and transmits power between the rotating shaft and the drive shaft of the electric motor with at least two speeds. A drive device control method comprising:
The speed change is based on the coincidence rotation speed, which is the rotation speed of the drive shaft with which the maximum power output from the electric motor to the drive shaft through the shift transmission means before and after switching the shift speed of the shift transmission means. A control method for a driving device, wherein the transmission means is controlled so that the gear position of the transmission means is switched.

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