JP2013225955A - Variable speed control method and variable speed control device for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable speed control method and a variable speed control device for an electric vehicle, capable of reducing torsional vibration between an electric motor and a transmission or the transmission and a tire when switching between creep control and regenerative control, irrespective of engagement or disengagement a roller clutch at the current gear position.SOLUTION: A variable speed control method includes: a creep control process of performing creep control for driving an electric motor at a determined threshold when a torque command value to the electric motor becomes lower than the threshold; a regenerative control process S1 of performing regenerative control for performing the regeneration of the electric motor; and a switching process of alternately switching between the creep control and the regenerative control. When switching from the creep control to the regenerative control, for example, the switching process includes a gradual load removing process S2 of gradually removing torque of the electric motor to a determined torque threshold in terms of a load from when a regenerative control command is issued.

Description

  The present invention relates to a shift control method and a shift control apparatus for an electric vehicle that shifts the rotation of an electric motor and transmits it to a wheel, and relates to a technique that can reduce vehicle torsional vibration when switching between creep control and regenerative control.

  As a drive device for an electric vehicle, there is a vehicle motor drive device that transmits power to drive wheels via an electric motor, a two-stage transmission, and a differential (differential). Several speed change control systems on this drive device have been proposed (for example, Japanese Patent Application No. 2011-123433 (Prior Art (1)), Japanese Patent Application No. 2012-13656 (Prior Art (2)), Patent Document 1 ).

  In the prior arts (1) and (2), in the shift control system, the electric motor is driven by torque control while the roller clutch at the current shift stage is engaged in the forward direction (this state is referred to as “ When switching from "power running" to regeneration, it is necessary to move the roller clutch of the current gear stage from the driving side to the non-driving side by rotational speed control. On the other hand, when switching from regeneration to power running, it is also necessary to move the roller clutch at the current gear stage from the non-drive side to the drive side.

  In Patent Document 1, a torque reaction force and a running resistance torque from the drive shaft to the transmission are estimated as disturbances, and a disturbance canceling torque is calculated based on the estimated disturbances. Then, the drive shaft torsional vibration is suppressed by generating the target torque and driving the electric motor.

JP 2006-50750 A

In the prior arts (1) and (2), if the electric motor suddenly loses torque while the roller clutch is moving from the engaged side to the neutral position, torsional vibration is generated between the electric motor and the reducer or between the reducer and the tire. In addition, abnormal noise due to backlash between the electric motor and the speed reducer or between the speed reducer and the tire is likely to occur.
In Patent Document 1, it is effective only when the clutch at the current shift stage is engaged. When the clutch is released, the proposed method cannot be used. That is, when the clutch is released, the electric motor is in a no-load state, and even if the electric motor is controlled, it is not possible to generate torque that cancels the disturbance.

  An object of the present invention is to reduce torsional vibration between an electric motor and a transmission or between a transmission and a tire when switching between creep control and regenerative control regardless of whether the roller clutch of the current gear stage is engaged or not. It is an object to provide a shift control method and a shift control apparatus for an electric vehicle.

The speed change control method for an electric vehicle according to the present invention includes a plurality of gear stages LA and LB having different speed ratios, and an input shaft 7 connected to a motor shaft 4 that is an output shaft of the electric motor 3 for traveling. The two-way roller clutches 16A and 16B of each gear stage that are interposed between the gear trains LA and LB of the respective gear stages and can be switched intermittently, and the intermittent switching of these roller clutches 16A and 16B. A transmission 5 having a transmission ratio switching mechanism 40 for performing,
Each of the roller clutches 16A and 16B has a roller 20 interposed in each wedge-shaped space S provided between the cam surfaces 19 of the inner rings 18A and 18B and the outer rings 23 and 23, and each roller 20 is engaged with a narrow portion of the wedge-shaped space S. It is a configuration in which it is in a connected state by being combined, and it is in a disconnected state by positioning each roller 20 in the expanded portion of the wedge-shaped space S by the cages 21A and 21B.
The gear ratio switching mechanism 40 is a mechanism that switches the contact and separation of the friction plates 35A and 35B connected to the retainers 21A and 21B to and from the outer rings 23 and 23 by the shift switching actuator 47 moving forward and backward. is there,
In a shift control method for an electric vehicle,
A creep control process for performing creep control for driving the electric motor 3 at the threshold when a torque command value to the electric motor 3 falls below a predetermined threshold;
A regenerative control process for performing regenerative control for regenerating the electric motor 3;
A switching process for switching the creep control and the regeneration control to each other;
Including
In the switching process, when switching from the creep control to the regenerative control or from the regenerative control to the creep control, the torque of the electric motor 3 is set to a predetermined torque from the time when a command for regenerative control or creep control is issued. A gradual unloading process of gradually unloading to a threshold value is included.

  According to this configuration, in the creep control process, when the torque command value for the electric motor 3 falls below a predetermined threshold value, the creep control for driving the electric motor 3 at the threshold value is performed. In the regeneration control process, regeneration control for performing regeneration of the electric motor 3 is performed. In the switching process, the creep control and the regeneration control are switched to each other. The switching process includes a gradual unloading process, and this gradual unloading process determines the torque of the electric motor 3, that is, the driving torque from the time when the regenerative control command is issued when switching from creep control to regenerative control. Gradually unload to torque threshold. In the gradual unloading process, when switching from regenerative control to creep control, the torque of the electric motor 3, that is, the regenerative torque is gradually unloaded to a predetermined torque threshold from the time when the command for creep control is issued. The “torque threshold value” is arbitrarily determined by, for example, simulation, actual vehicle running test, or the like. As described above, by gradually unloading the drive torque or regenerative torque of the electric motor 3, in other words, by unloading the motor torque step by step without unloading the motor torque at once, the current gear stage The torsional vibration between the electric motor 3 and the transmission 5 or between the transmission 5 and the tire can be reduced regardless of whether the roller clutches 16A and 16B are engaged or not.

  The switching process may be executed when any one of a drive range, a second speed range, and a first speed range is selected as the shift range of the shift operation member of the vehicle. While one of the ranges is selected, vehicle torsional vibration that may occur when the vehicle is running under torque control, for example, when the accelerator pedal 63 is switched between ON and OFF can be reduced.

The switching process includes a roller clutch moving process for moving the roller clutches 16A and 16B of the current gear stage from the driving side to the non-driving side by rotation speed control when switching from the creep control to the regenerative control. During the movement process, the electric motor 3 is set so that the target rotational speed of the electric motor 3 is obtained by subtracting a certain rotational speed threshold from the rotational speed obtained by multiplying the output shaft rotational speed by the speed reduction ratio of the current gear. It may be driven.
The roller clutch movement process may include a torque gradual output process for gradually outputting the torque of the electric motor 3 to a predetermined torque threshold. In this way, the motor torque is output stepwise over time until reaching the torque threshold, so that the roller clutches 16A and 16B at the current gear stage are moved from the driving side to the non-driving side by the rotational speed control. Vehicle torsional vibration can be reduced during the clutch movement process.

The switching process includes a roller clutch moving process for moving the roller clutches 16A and 16B of the current gear stage from the non-driving side to the driving side by rotation speed control when switching from the regeneration control to the creep control. During the movement process, the electric motor 3 is set so that the target rotational speed of the electric motor 3 is the rotational speed obtained by multiplying the output shaft rotational speed by the reduction gear ratio of the current gear and a certain rotational speed threshold value. It may be driven.
The roller clutch movement process may include a torque gradual output process for gradually outputting the torque of the electric motor 3 to a predetermined torque threshold. In this way, the motor torque is output stepwise over time until reaching the torque threshold, so that the roller clutches 16A and 16B at the current gear stage are moved from the non-driving side to the driving side by the rotational speed control. Vehicle torsional vibration can be reduced during the clutch movement process.

Switching from the regeneration control to the creep control is performed when the vehicle speed is equal to or higher than the first vehicle speed threshold, and switching from the creep control to the regeneration control is performed when the vehicle speed is equal to or lower than the second vehicle speed threshold. May be implemented. In this case, the hunting phenomenon of regenerative control and creep control can be avoided. The “hunting phenomenon” refers to a phenomenon in which a certain operation is frequently repeated.
The first vehicle speed threshold value may be greater than the second vehicle speed threshold value.

The shift control apparatus for an electric vehicle according to the present invention includes a gear train of a plurality of shift stages having different gear ratios, an input shaft connected to a motor shaft that is an output shaft of a traveling electric motor, and a gear of each of the shift stages. A transmission having a two-way roller clutch of each gear stage that is interposed between each row and can be switched intermittently, and a gear ratio switching mechanism that switches between the intermittent states of each of the roller clutches,
Each roller clutch is in a connected state when a roller is interposed in each wedge-shaped space provided between the cam surface of the inner ring and the outer ring, and each roller engages with a narrowed portion of the wedge-shaped space. It is configured to be in a cut state by being positioned in the spread part of the wedge-shaped space,
The transmission ratio switching mechanism is a mechanism that switches contact and separation of a rotating friction plate connected to a retainer with an outer ring by advancing and retreating a shift member by a transmission switching actuator.
In a shift control device for an electric vehicle,
A creep control means for performing creep control for driving the electric motor at the threshold value when a torque command value to the electric motor falls below a predetermined threshold value;
Regenerative control means for performing regenerative control for regenerating the electric motor;
Switching means for switching the creep control and the regeneration control to each other;
Including
When the switching means switches from the creep control to the regenerative control or from the regenerative control to the creep control, the switching means sets the torque of the electric motor from a predetermined torque threshold value when a command for regenerative control or creep control is issued. And gradually unloading means for unloading.

  According to this configuration, when the torque command value for the electric motor falls below a predetermined threshold value, the creep control means performs creep control for driving the electric motor at the threshold value. The regeneration control means performs regeneration control that performs regeneration of the electric motor. The switching means switches between creep control and regenerative control. The switching means includes a gradual unloading means. When the gradual unloading means is switched from the creep control to the regenerative control, the torque of the electric motor, that is, the driving torque is set to a predetermined torque from the time when the regenerative control command is issued. Gradually unload to the threshold. In addition, the gradual unloading means gradually unloads the torque of the electric motor, that is, the regenerative torque from the time when the command for creep control is issued when switching from the regeneration control to the creep control. Thus, the torsional vibration of the vehicle can be reduced by unloading the driving torque or the regenerative torque of the electric motor at a time without unloading it step by step.

The shift control method for an electric vehicle according to the present invention includes a gear train of a plurality of shift stages having different gear ratios, an input shaft connected to a motor shaft that is an output shaft of a traveling electric motor, and a gear of each of the shift stages. A transmission having a two-way roller clutch of each gear stage that is interposed between each row and capable of switching between on and off, and a gear ratio switching mechanism that switches between on and off of each of the roller clutches, The roller clutch is in a connected state when a roller is interposed in each wedge-shaped space provided between the cam surface of the inner ring and the outer ring, and each roller engages with a narrow portion of the wedge-shaped space. The gear ratio switching mechanism is configured to shift the contact and separation of the rotating friction plate connected to the retainer to the outer ring with a shift switching actuator. A mechanism for switching by the advance and retreat, in the shift control method in an electric vehicle,
A creep control process for performing creep control for driving the electric motor at the threshold value when a torque command value for the electric motor falls below a predetermined threshold value; and a regeneration control process for performing regenerative control for regenerating the electric motor; A switching process for switching the creep control and the regeneration control to each other, and the switching process is a command for regeneration control or creep control when switching from the creep control to the regeneration control or from the regeneration control to the creep control. From the point in time when the electric motor is issued, it includes a gradual unloading process of gradually unloading the torque of the electric motor to a predetermined torque threshold. Therefore, the torsional vibration between the electric motor and the transmission or between the transmission and the tire can be reduced when switching between the creep control and the regenerative control regardless of whether the roller clutch at the current gear stage is engaged or not.

The shift control apparatus for an electric vehicle according to the present invention includes a gear train of a plurality of shift stages having different gear ratios, an input shaft connected to a motor shaft that is an output shaft of a traveling electric motor, and a gear of each of the shift stages. A transmission having a two-way roller clutch of each gear stage that is interposed between each row and capable of switching between on and off, and a gear ratio switching mechanism that switches between on and off of each of the roller clutches, The roller clutch is in a connected state when a roller is interposed in each wedge-shaped space provided between the cam surface of the inner ring and the outer ring, and each roller engages with a narrow portion of the wedge-shaped space. The gear ratio switching mechanism is configured to shift the contact and separation of the rotating friction plate connected to the retainer to the outer ring with a shift switching actuator. A mechanism for switching by the advance and retreat, the shift control system of an electric vehicle,
A creep control means for performing creep control for driving the electric motor at the threshold value when a torque command value for the electric motor falls below a predetermined threshold; and a regeneration control means for performing regeneration control for regenerating the electric motor; Switching means for switching the creep control and the regeneration control to each other, and the switching means commands the regeneration control or creep control when switching from the creep control to the regeneration control or from the regeneration control to the creep control. From the point in time when the electric motor is issued, it gradually includes unloading means for gradually unloading the torque of the electric motor to a predetermined torque threshold value. Therefore, the torsional vibration between the electric motor and the transmission or between the transmission and the tire can be reduced when switching between the creep control and the regenerative control regardless of whether the roller clutch at the current gear stage is engaged or not.

1 is a schematic diagram of an electric vehicle to which a shift control method and a shift control apparatus according to an embodiment of the present invention are applied. It is the schematic of the hybrid vehicle to which the same shift control method and shift control device are applied. It is sectional drawing of the motor drive device for vehicles of the vehicle shown in FIG. 1, FIG. It is sectional drawing of the reduction ratio switching mechanism of the motor drive device for vehicles. It is a schematic block diagram of the transmission control system which controls the motor drive device for vehicles. It is a block diagram of the inverter apparatus of the motor drive apparatus for vehicles. It is explanatory drawing of the lever operation panel of the vehicle. It is a block diagram of the inverter control apparatus of the motor drive device for vehicles. It is a block diagram which shows the conceptual structure of the transmission control apparatus of the motor drive device for vehicles. It is a flowchart which shows the outline of the control method which switches from creep control to regenerative control in the transmission control method. It is a flowchart which shows the outline of the control method which switches from regeneration control to creep control in the transmission control method. FIG. 5 is a partial enlarged cross-sectional view of FIG. 4. It is sectional drawing along the AA line of FIG. It is sectional drawing along the BB line of FIG. It is sectional drawing along CC line of FIG. It is sectional drawing which shows the shift mechanism of the motor drive device for vehicles. FIG. 5 is an exploded perspective view of a roller clutch and the like in the reduction ratio switching mechanism of FIG. 4.

  Hereinafter, a shift control method for an electric vehicle according to an embodiment of the present invention will be described. The following description also includes a description of the shift control device. FIG. 1 shows an electric vehicle EV in which a pair of left and right front wheels 1 are drive wheels driven by a vehicle motor drive device A, and a pair of left and right rear wheels 2 are driven wheels.

  FIG. 2 shows a hybrid vehicle HV in which a pair of left and right front wheels 1 are main drive wheels driven by an engine E, and a pair of left and right rear wheels 2 are auxiliary drive wheels driven by a vehicle motor drive device A. The hybrid vehicle HV is provided with a transmission T for shifting the rotation of the engine E and a differential D for distributing the rotation output from the transmission T to the left and right front wheels 1. The speed change control method and speed change control device of this embodiment are applied to the vehicle motor drive device A shown in FIGS.

  As shown in FIG. 3, the vehicle motor drive device A includes a traveling electric motor 3, a transmission 5 that shifts and outputs the rotation of the output shaft 4 of the electric motor 3, and an output from the transmission 5. The differential 6 is distributed to the pair of left and right front wheels 1 of the electric vehicle EV shown in FIG. 1 or to the pair of left and right rear wheels 2 of the hybrid vehicle shown in FIG.

  The transmission 5 has two gear stages, and as shown in FIG. 3, a plurality of gear trains LA and LB (two trains in this example) having different gear ratios, and the output of the electric motor 3. Two-way type roller clutches 16A and 16B for each gear stage, which are respectively connected to the gear shaft LA and LB of each gear stage and can be switched intermittently. And a gear ratio switching mechanism 40 for switching the on / off state of the roller clutches 16A and 16B.

  The transmission 5 and the gear ratio switching mechanism 40 will be briefly described here within a range necessary for understanding the shift control method / device, and will be described in detail after the description of the shift control method / device.

  The transmission 5 includes an input shaft 7 to which the rotation of the motor shaft 4 is input, an output shaft 8 disposed in parallel to the input shaft 7 at a distance from each other, and a parallel having the gear trains LA and LB. It is a shaft always meshing transmission. The input gear 9A of the first gear train LA and the input gear 9B of the second gear train LB are integrally provided on the input shaft, and the output gear 10A of the first gear train LA and the output gear 10B of the second gear train LB are output shafts. 8 is rotatably installed on the outer periphery. The roller clutches 16A and 16B are interposed between the output gears 10A and 10B and the output shaft 8.

  The roller clutches 16A and 16B are respectively formed of a flat cam surface 19 and an outer ring 23 on the outer periphery of the inner ring 18B whose outer peripheral surface is a polygonal shape, as described in the example of the two-speed roller clutch 16B shown in FIG. A roller 20 is interposed in each wedge-shaped space S provided between the inner circumferential cylindrical surfaces. In the wedge-shaped space S, both sides in the circumferential direction are narrowed, and the center in the circumferential direction is an expanded portion. The roller clutches 16A and 16B are connected when the rollers 20 are engaged with the narrowed portions of the wedge-shaped space S, and are disconnected when the rollers 20 are positioned at the expanded portions of the wedge-shaped space S by the cage 21B. It is the composition which becomes.

  As shown in FIG. 4, the gear ratio switching mechanism 40 switches between contact and separation of the annular friction plates 35A and 35B, which are connected to the cages 21A and 21B of the roller clutches 16A and 16B and rotate, with the outer ring 23. This is a mechanism that is switched by the advancement and retraction of the shift fork 45 that is a shift member by the actuator 47. The shift mechanism 41 is a mechanism part that operates the friction plates 35 </ b> A and 35 </ b> B in the speed ratio switching mechanism 40, and includes a speed change switching actuator 47 and a shift fork 45.

  The shift switching actuator 47 is an electric motor for shifting. The rotation of the output shaft 47a is converted into a linear motion of the shift rod 46 by the feed screw mechanism 48, and the shift fork 45 attached to the shift rod 46 is axially moved. Move to. As the shift fork 45 moves, the shift sleeve 43 and the shift ring 34 move. The shift ring 34 presses the friction plates 35A and 35B against the side surface of the crack outer ring 23 (output gears 10A and 10B). As a result, when the inner rings 18A, 18B with cam surfaces and the outer ring 23 rotate relative to each other, a frictional force (torque) acts between the friction plates 35A, 35B and the outer ring 23 via the cages 21A, 21B. Thus, the roller 20 can be pushed into the narrowed portion of the wedge-shaped space S.

  The cages 21A and 21B are rotatable with respect to the inner rings 18A and 18B. However, the switch springs 22A and 22B (FIG. 12) allow the center of the cam surface 19 (FIG. 12) of the inner rings 18A and 18B, that is, a wedge-shaped space. The neutral position where S is spread and the center of the pocket 21a in the circumferential direction are biased. The friction plates 35A and 35B are connected to the switch springs 22A and 22B so as to be rotatable together with the cages 21A and 21B.

  FIG. 5 is a block diagram showing a control system for controlling the vehicle motor drive device A. As shown in FIG. This control system has an integrated ECU 60, a transmission ECU 61, and an inverter device 62. Signal transfer among the three units of the integrated ECU 60, the shift ECU 61, and the inverter device 62 is performed by CAN communication (controller area network).

  The integrated ECU 60 is an electronic control device that performs cooperative control among all on-vehicle electronic control devices, and includes an accelerator opening sensor 63a of the accelerator pedal 63, a brake opening sensor 91a of the brake pedal 91, and a steering angle sensor 92a of the steering wheel 92. The shift lever 93 is connected to a lever position sensor 93a for manually switching the gear position. The integrated ECU 60 shifts the accelerator position sensor 63a, the brake position sensor 91a, the steering angle sensor 92a, the accelerator position signal detected by the lever position sensor 93a, the brake position signal, the steering angle signal, and the lever position signal. A function to transmit to the ECU 61 and a function to perform the cooperative control by these four types of signals and signals from various other sensors and the like are provided.

  The shift ECU 61 is an electronic control device that controls automatic shift based on various signals transmitted from the ECU 60 and various signals directly input to the shift ECU 61. The shift ECU 61 performs shift determination based on the various input signals. 5 and a command to the inverter device 62.

The transmission ECU 61 includes the following functions (1) to (8).
(1) The vehicle speed sensor 94 and the acceleration sensor 95 receive vehicle speed and vehicle acceleration / deceleration detection signals, the accelerator opening signal is received from the integrated ECU 60, and automatic shift determination is performed.
(2) If it is determined that the brake is sudden, automatic shift is not performed.
(3) If it is determined that the steering wheel is a sudden handle, automatic shifting is not performed.
(4) A position signal of the shift lever 93 is received from the integrated ECU 60, and creep control of the electric motor is performed.

(5) Control according to operation of the 1st-3rd operation switch 96-98 operated by the driver | operator is performed.
First operation switch 96: an automatic / manual shift switching toggle switch.
Second operation switch 97: This is a tact switch, and is effective only when the first operation switch 96 is set by manual shifting. When the second operation switch 97 is pressed, an upshift is performed.
Third operation switch 98: a tact switch, which is valid only when the first operation switch 96 is set by manual shifting. When the third operation switch 98 is pressed, a downshift is performed.

(6) The vehicle speed, electric motor rotation speed, torque command value, etc. are displayed on the display unit 99. The display unit 99 is a device that displays an image, such as a liquid crystal display device, or a device that displays a pointer.
(7) A function of detecting the shift position of the shift switching actuator 47 from a shift position sensor 68 attached to the transmission 5 and a function of acquiring the rotation speed of the electric motor 3 from the inverter are provided.
(8) A function of transmitting a torque command or a rotational speed command and a shift command to the inverter device 62 and a function of driving a shift switching actuator 47 attached to the transmission 5 are provided.

The shift ECU 61 is programmed with shift modes of an automatic shift mode and a manual shift mode, and the automatic shift mode and the manual shift mode are switched by the operation of the first operation switch 96 by the driver.
The speed change control method and speed change control device of this embodiment relate to control in the automatic speed change mode by the speed change ECU 61. The transmission ECU 61 has various function achievement means and the like (81, 82, 83, 87) shown in FIG. 9, which will be described later.

  In FIG. 5, the inverter device 62 is supplied with DC power from the battery 69, supplies AC motor driving power to the electric motor 3, and controls the supplied power based on a signal from the transmission ECU 61. A signal indicating the number of rotations of the electric motor 3 is input to the inverter device 62 from a rotation angle sensor 66 that is a rotation detection device provided in the electric motor 3.

  The inverter device 62 has a function of driving the electric motor 3 and a function of obtaining a rotation angle signal of the electric motor 3 from the rotation angle sensor 66. As shown in FIG. 6, the inverter device 62 includes an inverter 71 and an inverter control circuit 72 that controls the inverter 71. Each phase of the electric motor 3 (at the connection point of the inverter 71, U, V, W phase upper arm switching elements Up, Vp, Wp and U, V, W phase lower arm switching elements Un, Vn, Wn) U, V, W phase) terminals are connected. To the inverter 71, an open / close command is given to each switching element Up, Vp, Wp, Un, Vn, Wn from the inverter control circuit 72 so as to output three-phase AC power.

  The electric motor 3 performs commutation by energization of three phases. A large current is required to drive the electric motor 3.

  FIG. 7 shows the configuration of the shift lever operation panel 75. As the driver manually operates the shift lever (shift operation member) 93, P (parking), R (reverse), N (neutral), D (drive), 2nd speed (second) Each range of 1st speed (low) can be switched. The shift lever operation panel 75 is a display device indicating which range is currently switched in this way. Range selection information on the shift lever operation panel 75 is input to the integrated ECU 60. The first speed range is the first speed state. The shift lever operation panel 75 may serve as a touch panel type input means and may be an operation means operated by a driver instead of the shift lever 93.

  FIG. 8 shows a block diagram of the electric motor 3, inverter torque control, and inverter rotation speed control. The inverter control circuit 72 can be controlled by switching between torque control and rotation speed control. Both torque control and rotation speed control are feedback control and vector control. Torque control and rotation speed control are performed at the time of shifting, and torque control is performed at times other than shifting. Detailed description is omitted.

The configuration of the inverter control circuit 72 shown in the figure will be described together with an outline of the torque control method.
The control circuit 72 acquires an accelerator signal (torque command) and the electric motor rotation number, and creates a current command value in the current command unit 101. At the time of torque control, the current command unit 101 receives a torque command generated by the torque command unit 110 of the speed change ECU 61 from the accelerator signal. Note that the torque command unit 110 and the speed command unit 106 of the transmission ECU 61 in FIG. 8 collectively indicate means for outputting the torque command and the speed command among the components of the transmission ECU 61.

  The power converter 62a performs PWM control of the inverter 71 according to the PWM duties Vu, Vv, and Vw, and drives the electric motor 3.

The rotation speed control by the inverter control circuit 72 of FIG.
The speed command unit 106 is a means for giving a speed command to the inverter control circuit 72 and is provided in the speed change ECU 61. The speed command unit 106 calculates a target rotational speed of the electric motor 3 based on the vehicle speed at the time of shifting and the speed ratio of the selected target shift stage. The calculated target rotational speed is instructed to the inverter control circuit 72 of the inverter device 62 as a speed command.

Further, the rotor angle of the electric motor 3 is acquired from the rotation angle sensor 66, and the actual rotation speed of the electric motor 3 is calculated by the speed calculation unit 108. The difference between the speed command of the speed command unit 106 and the actual electric motor rotation speed calculated by the speed calculation unit 108 is obtained by the comparison unit 109, and the control unit 107 performs PID control (proportional integral derivative control), in association with the difference. Alternatively, PI control (proportional integral control) is performed, and the control amount is input to the current command unit 101 as a torque command. During the rotation speed control, a torque command based on the speed command from the speed calculation unit 108 is input to the current command unit 101 instead of the torque command from the torque command unit 110.
In the rotational speed control, the target rotational speed of the electric motor 3 is calculated at a constant interval (for example, 1 msec), and even if the vehicle speed changes suddenly during the shift, the target rotational speed of the shift can follow the change in the vehicle speed. It has. Thereby, the shift shock can be reduced.

In FIG. 8, the inverter control circuit 72 is described separately for a speed control unit 73 and a torque control unit 74.
The torque control unit 74 is a part of the inverter control circuit 72 that performs the function of controlling the electric motor 3 by torque control. The current command unit 101, the current PI control unit 102, and the two-phase / three-phase changing unit shown in FIG. 103, a three-phase / two-phase change unit 104, a speed calculation unit 108, and a prediction unit 111.
The speed control unit 73 is a part of the inverter control circuit 72 that performs the function of controlling the electric motor 3 by speed control. The speed control unit 73 includes a comparison unit 109 and a control unit 107. A torque command is given to the unit 101, and the subsequent control is performed by the torque control unit 74.

Next, a shift control device for a vehicle motor drive device in an electric vehicle will be described with reference to the block diagram of FIG. The electric vehicle to be controlled is the electric vehicle described above with reference to FIGS. 1 to 7 to which the shift control method of the above embodiment is applied.
This shift control device for an electric vehicle is a device that performs the shift control method of the above embodiment, and the shift ECU 61 is provided with a shift control means 80 that is a means for performing basic control of shift. The shift ECU 61 outputs a torque command to the inverter control circuit 72 by the shift control means 80 as a torque control for the control of the electric motor 3 other than during the automatic shift, and switches between the torque control and the rotational speed control during the shift. The shift ECU 61 is provided with the following creep control means 81, regeneration control means 82, switching means 87, and memory 83. The memory 83 is composed of a ROM or the like, for example, and a storage area 83a of the memory 83 stores threshold values, a rotation speed threshold value, a torque threshold value, and first and second vehicle speed threshold values which will be described later.

When the torque command value for the electric motor 3 falls below a predetermined threshold value, the creep control means 81 performs creep control for driving the electric motor 3 with the threshold value. The torque command value when performing this creep control is positive.
The regeneration control unit 82 performs regeneration control for performing regeneration of the electric motor 3. The regenerative control means 82 performs regenerative control when the accelerator is turned off for the control to make the accelerator opening signal equal to or greater than the threshold value when the accelerator opening signal falls below the threshold value during traveling by torque control. If it falls below the threshold value for time, the negative torque of the threshold value for regeneration is input, and the rollers 20 of the roller clutches 16A and 16B are always moved to the non-driving side. The vehicle speed at which this regenerative control is performed is preferably set to a predetermined vehicle speed or higher.

  The switching unit 87 is a unit that switches between creep control and regenerative control, and when the shift lever 93 of the vehicle selects any one of the drive range, the second speed range, and the first speed range, It is configured to be controllable. The switching means 87 includes a gradual unloading means 88. When the gradual unloading means 88 switches from the creep control to the regenerative control, the torque of the electric motor 3, that is, the drive torque, from the time when the regenerative control command is issued, Gradually unload to the specified torque threshold. In addition, the gradual unloading means 88 gradually unloads the torque of the electric motor 3, that is, the regenerative torque from the time when the command for the creep control is issued when switching from the regeneration control to the creep control.

FIG. 10 is a flowchart showing an outline of a control method for switching from creep control to regenerative control in the shift control method according to this embodiment. During the creep control of the electric motor 3 by the creep control means 81, the switching means 87 starts this processing.
Step 1: Accelerator pedal opening and vehicle speed are detected and a regeneration control command is issued.
Step 2: Gradual unloading means 88 in switching means 87 gradually unloads the drive torque of electric motor 3 by torque control.

Step 3: The torque control is switched to the rotational speed control, and the roller clutches 16A and 16B at the current gear stage are moved from the driving side to the non-driving side by the rotational speed control.
Step 4: The control of the electric motor 3 is switched from the rotational speed control to the torque control, and thereafter, the regenerative control means 82 gives the regenerative torque value of the electric motor 3 by n-time interpolation control. Since this interpolation control is n-time interpolation, the interpolation value can always track the signal of the regeneration command. In the tracking process in which the error between the interpolation value and the signal of the regenerative command value is reduced, if the error falls within a certain threshold, the tracking operation is completed and the n-time interpolation control is also completed.

FIG. 11 is a flowchart showing an outline of a control method for switching from regenerative control to creep control in the shift control method according to this embodiment. While the electric motor 3 is being regeneratively controlled by the regenerative control means 82, the switching means 87 starts this processing.
Step 1: Accelerator pedal opening and vehicle speed are detected and a creep control command is issued.
Step 2: Gradual unloading means 88 in switching means 87 gradually unloads the regenerative torque of electric motor 3 by torque control.

Step 3: The torque control is switched to the rotation speed control, and the roller clutches 16A and 16B at the current gear stage are moved from the non-drive side to the drive side by the rotation speed control.
Step 4: The control of the electric motor 3 is switched from the rotation speed control to the torque control, and thereafter, the creep control means 81 gives the drive torque value of the electric motor 3 by n-time interpolation control. Since this interpolation control is performed n times, the interpolation value can always track the signal of the creep control command. If the error falls within a certain threshold during the tracking process for reducing the error with the creep control command value, the tracking operation is completed and the interpolation control is completed n times.

Next, details of the vehicle motor drive device shown in FIGS. 3 and 4 will be described with reference to FIGS.
In FIG. 3, the motor shaft 4 is coaxially arranged in series with the input shaft 7, and is rotationally driven by a stator 12 of the electric motor 3 fixed to the housing 11. The input shaft 7 is rotatably supported by a pair of opposed bearings 13 incorporated in the housing 11, and the shaft end of the input shaft 7 is connected to the motor shaft 4 by spline fitting. The output shaft 8 is rotatably supported by a pair of opposed bearings 14 incorporated in the housing 11.

  The first-speed input gear 9 </ b> A and the second-speed input gear 9 </ b> B are arranged at an interval in the axial direction, and are fixed to the input shaft 7 so as to rotate integrally with the input shaft 7 about the input shaft 7. The first-speed output gear 10A and the second-speed output gear 10B are also arranged at intervals in the axial direction.

  As shown in FIG. 4, the first-speed output gear 10 </ b> A is formed in an annular shape that penetrates the output shaft 8, and is supported by the output shaft 8 via a bearing 15, and the output shaft 8 is centered on the output shaft 8. And can be rotated. Similarly, the second speed output gear 10 </ b> B is also rotatably supported by the output shaft 8 via the bearing 15.

  The first speed input gear 9A and the first speed output gear 10A mesh with each other, and rotation is transmitted between the first speed input gear 9A and the first speed output gear 10A. The 2nd speed input gear 9B and the 2nd speed output gear 10B are also meshed, and rotation is transmitted between the 2nd speed input gear 9B and the 2nd speed output gear 10B by the meshing. The reduction ratio between the second speed input gear 9B and the second speed output gear 10B is smaller than the reduction ratio between the first speed input gear 9A and the first speed output gear 10A.

  Between the first-speed output gear 10A and the output shaft 8, a first-speed two-way roller clutch 16A that incorporates torque transmission and switching between the first-speed output gear 10A and the output shaft 8 is incorporated. Further, a 2-speed 2-way roller clutch 16B is incorporated between the 2-speed output gear 10B and the output shaft 8 to switch torque transmission and interruption between the 2-speed output gear 10B and the output shaft 8. .

  Since the first-speed two-way roller clutch 16A and the second-speed two-way roller clutch 16B have the same symmetrical configuration, the second-speed two-way roller clutch 16B will be described below. The parts corresponding to the 2-speed 2-way roller clutch 16B are denoted by the same reference numerals or the reference numerals in which the alphabet B at the end is replaced with A, and the description thereof is omitted.

  As shown in FIGS. 12 to 14, the two-speed two-way roller clutch 16 </ b> B includes a cylindrical surface 17 provided on the inner periphery of the second-speed output gear 10 </ b> B and an annular second gear that is prevented from rotating on the outer periphery of the output shaft 8. It comprises a cam surface 19 formed on the cam member 18B, a roller 20 incorporated between the cam surface 19 and the cylindrical surface 17, a second speed holder 21B for holding the roller 20, and a second speed switch spring 22B. The cam surface 19 is a surface that forms a wedge-shaped space S that gradually narrows from the center in the circumferential direction toward both ends in the circumferential direction with the cylindrical surface 17. For example, as shown in FIG. 13, the cam surface 19 faces the cylindrical surface 17. It is a flat surface.

  As shown in FIGS. 4 and 17, the 2-speed retainer 21 </ b> B includes a cylindrical portion 24 in which a plurality of pockets 21 a for accommodating the rollers 20 are formed at intervals in the circumferential direction, and a radial direction from one end of the cylindrical portion 24. And an inward flange portion 25 extending inward. The radially inner end of the inward flange portion 25 is supported so as to be slidable in the circumferential direction on the outer periphery of the second-speed cam member 18B, and the second-speed cage 21B causes the cam surface 19 and the cylindrical surface 17 to slide. Between the engagement position where the roller 20 is engaged and the neutral position where the engagement of the roller 20 is released, rotation relative to the output shaft 8 is possible. Further, the inward flange portion 25 of the second-speed cage 21B is restricted from moving in the axial direction, thereby making the second-speed cage 21B immovable in the axial direction.

  As shown in FIG. 13, each cam surface 19 is formed symmetrically with respect to a virtual plane including the center of rotation, so that the rollers 20 arranged between each cam surface 19 and the cylindrical surface 17 can rotate forward. The engagement is possible in both the direction and the reverse direction. That is, when the vehicle is advanced by the torque generated by the electric motor 3, the roller 20 held by the second-speed cage 21B is rotated by rotating the second-speed cage 21B in the normal rotation direction with respect to the output shaft 8. Is engaged with a space narrowing portion on the forward rotation direction side between the cam surface 19 and the cylindrical surface 17, and torque in the forward rotation direction is transmitted between the second speed output gear 9 </ b> B and the output shaft 8 via the roller 20. On the other hand, when the vehicle is moved backward by the torque generated by the electric motor 3, the second speed retainer 21B is rotated relative to the output shaft 8 in the reverse rotation direction to maintain the second speed. The roller 20 held by the vessel 21B is engaged with the space narrowing portion on the reverse direction side between the cam surface 19 and the cylindrical surface 17, and between the second-speed output gear 9B and the output shaft 8 via the roller 20. Transmit torque in reverse direction It is possible to be.

  As shown in FIGS. 14 and 17, the two-speed switch spring 22 </ b> B includes a C-shaped annular portion 26 in which a steel wire is wound in a C shape, and a pair extending radially outward from both ends of the C-shaped annular portion 26. Extending portions 27, 27. The C-shaped annular portion 26 is fitted into a circular switch spring accommodating recess 28 formed on the axial end surface of the second-speed cam member 18B, and the pair of extending portions 27 and 27 are axial end surfaces of the second-speed cam member 18B. It is inserted in the radial groove 29 formed in.

  The radial groove 29 is formed so as to extend radially outward from the inner peripheral edge of the switch spring accommodating recess 28 and reach the outer periphery of the second-speed cam member 18B. The extension portion 27 of the second speed switch spring 22B protrudes from the radially outer end of the radial groove 29, and the protruding portion of the extension portion 27 from the radial groove 29 is the cylindrical portion of the second speed cage 21B. 24 is inserted into a notch 30 formed at the end in the axial direction. The radial groove 29 and the notch 30 are formed to have the same width.

  The extending portions 27, 27 are in contact with the inner surface facing the circumferential direction of the radial groove 29 and the inner surface facing the circumferential direction of the notch 30, respectively, and 2 by the circumferential force acting on the contact surface. The speed holder 21B is elastically held in the neutral position.

  That is, when the second-speed cage 21B is rotated relative to the output shaft 8 and moved in the circumferential direction from the neutral position shown in FIG. 17, the position of the radial groove 29 and the position of the notch 30 are shifted in the circumferential direction. Therefore, the C-shaped annular portion 26 is elastically deformed in the direction in which the distance between the pair of extending portions 27, 27 is narrowed, and the pair of extending portions 27, 27 of the two-speed switch spring 22B are caused to be radially grooved 29 by the elastic restoring force. The inner surface of the notch 30 and the inner surface of the notch 30 are pressed, and a force in a direction to return the second-speed cage 21B to the neutral position is applied by the pressing.

  As shown in FIG. 4, the first-speed cam member 18A and the second-speed cam member 18B are prevented from rotating with respect to the output shaft 8 by spline fitting. The cam surface 19 of the first speed cam member 18A and the cam surface 19 of the second speed cam member 18B have the same number and the same phase. Further, the first speed cam member 18 </ b> A and the second speed cam member 18 </ b> B are non-movable in the axial direction by a pair of retaining rings 31 fitted to the outer periphery of the output shaft 8. A spacer 32 is incorporated between the first speed cam member 18A and the second speed cam member 18B.

  The first-speed two-way roller clutch 16A and the second-speed two-way roller clutch 16B can be selectively engaged by the speed change actuator 33.

  As shown in FIG. 12, the speed change actuator 33 includes a shift ring 34 provided so as to be movable in the axial direction between the first speed output gear 10A and the second speed output gear 10B, and the first speed output gear 10A and the shift ring 34. A first-speed friction plate 35A incorporated in between, and a second-speed friction plate 35B incorporated between the second-speed output gear 10B and the shift ring 34.

  Here, since the first-speed friction plate 35A and the second-speed friction plate 35B have the same configuration with left-right symmetry, the second-speed friction plate 35B will be described below, and the first-speed friction plate 35A corresponds to the second-speed friction plate 35B. Parts are denoted by the same reference numerals or reference numerals in which the alphabet B at the end is replaced with A, and description thereof is omitted.

  The second-speed friction plate 35B is provided with a projecting piece 36 that engages with the notch 30 of the second-speed retainer 21B. The engagement between the projecting piece 36 and the notch 30 causes the second-speed friction plate 35B to hold the second speed. The rotation is stopped by the vessel 21B. The notch 30 of the second-speed retainer 21B accommodates the projecting piece 36 of the second-speed friction plate 35B so as to be slidable in the axial direction. By this sliding, the second-speed friction plate 35B rotates around the second-speed retainer 21B. It can move in the axial direction with respect to the second-speed retainer 21B between a position in contact with the side surface of the second-speed output gear 10B and a position away from the second-speed output gear 10B.

  A recess 37 is formed at the tip of the projecting piece 36 of the second speed friction plate 35 </ b> B, and a protrusion 38 that engages with the recess 37 is formed on the outer periphery of the spacer 32. The concave portion 37 and the convex portion 38 are engaged with the concave portion 37 and the convex portion 38 in a state where the second speed friction plate 35B is located away from the side surface of the second speed output gear 10B. Is prevented from rotating around the output shaft 8 via the spacer 32. At this time, the second-speed retainer 21B, which is prevented from rotating by the second-speed friction plate 35B, is held in the neutral position. Further, in a state where the second speed friction plate 35B is in a position in contact with the side surface of the second speed output gear 10B, the engagement between the concave portion 37 and the convex portion 38 is released to release the rotation prevention of the second speed friction plate 35B. It has become so.

  Between the second speed friction plate 35B and the second speed cam member 18B, a second speed separation spring 39B is incorporated in an axially compressed state, and the second speed friction plate is generated by the elastic restoring force of the second speed separation spring 39B. 35B is urged in a direction away from the side surface of the second-speed output gear 10B.

  The second speed separating spring 39B is a coil spring wound along the outer periphery of the spacer 32, and one end thereof is supported by the end face in the axial direction of the second speed cam member 18B via the second speed washer 39B. The 2-speed washer 39B is formed in an annular shape so as to cover the radial groove 29 on the axial end surface of the 2-speed cam member 18B.

  The shift ring 34 presses the first-speed friction plate 35A to contact the side surface of the first-speed output gear 10A and the first-speed shift position SP1f to press the second-speed friction plate 35B to contact the side surface of the second-speed output gear 10B. The second-speed shift position SP2f is supported so as to be movable in the axial direction. Further, a shift mechanism 41 that moves the shift ring 34 in the axial direction between the first-speed shift position SP1f and the second-speed shift position SP2f is provided. The shift mechanism 41 constitutes a part of the gear ratio switching mechanism 40 as described above.

  As shown in FIGS. 15 and 16, the shift mechanism 41 is related to a shift sleeve 43 that rotatably supports the shift ring 34 via a rolling bearing 42 and an annular groove 44 provided on the outer periphery of the shift sleeve 43. The two-forked shift fork 45, the shift rod 46 to which the shift fork 45 is fixed, the shift switching actuator 47 that is a shift motor, and the motion conversion that converts the rotation of the shift switching actuator 47 into the linear motion of the shift rod 46. It consists of a mechanism 48 (feed screw mechanism or the like).

  As shown in FIG. 16, the shift rod 46 is arranged parallel to the output shaft 8 with a space therebetween, and is supported by a pair of sliding bearings 49 incorporated in the housing 11 so as to be slidable in the axial direction. . The rolling bearing 42 incorporated between the shift ring 34 and the shift sleeve 43 is assembled so as to be immovable in the axial direction with respect to both the shift ring 34 and the shift sleeve 43.

  In the shift mechanism 41, the rotation of the shift switching actuator 47 is converted into a linear motion by the motion conversion mechanism 48 and transmitted to the shift fork 45, and the linear motion of the shift fork 45 is transmitted to the shift ring 34 via the rolling bearing 42. By doing so, the shift ring 34 is moved in the axial direction.

  As shown in FIG. 12, a preload spring 50 that is compressible in the axial direction is incorporated in the axial clearance on both sides between the shift fork 45 and the annular groove 44. Thus, when the first speed friction plate 35A is pressed by the shift ring 34 and brought into contact with the side surface of the first speed output gear 10A, the preload spring 50 is adjusted by adjusting the relative position in the axial direction of the shift fork 45 with respect to the shift sleeve 43. Thus, it is possible to adjust the friction force between the contact surfaces of the first speed friction plate 35A and the first speed output gear 10A. Further, also when the second speed friction plate 35B is pressed by the shift ring 34 and brought into contact with the side surface of the second speed output gear 10B, the frictional force between the contact surfaces of the second speed friction plate 35B and the second speed output gear 10B is adjusted. Is possible.

  As shown in FIG. 3, a differential drive gear 51 that transmits the rotation of the output shaft 8 to the differential 6 is fixed to the output shaft 8.

  The differential 6 includes a differential case 53 rotatably supported by a pair of bearings 52, a ring gear 54 that is fixed to the differential case 53 coaxially with the rotational center of the differential case 53, and meshes with the differential drive gear 51, and the rotational center of the differential case 53. The pinion shaft 55 is fixed to the differential case 53 in a perpendicular direction, the pair of pinions 56 is rotatably supported by the pinion shaft 55, and the pair of left and right side gears 57 that mesh with the pair of pinions 56. The left side gear 57 is connected to the shaft end portion of the axle 58 connected to the left wheel, and the right side gear 57 is connected to the shaft end portion of the axle 58 connected to the right wheel. When the output shaft 8 rotates, the rotation of the output shaft 8 is transmitted to the differential case 53 via the differential drive gear 51, and the rotation of the differential case 53 is distributed to the left and right wheels via the pinion 56 and the side gear 57.

Below, the operation example of the motor drive apparatus A for vehicles is demonstrated.
First, as shown in FIG. 12, when the first speed friction plate 35A is separated from the side surface of the first speed output gear 10A and the second speed friction plate 35B is also separated from the side surface of the second speed output gear 10B, the first speed holding is performed. 21A is held in the neutral position by the elastic force of the first speed switch spring 22A, and the second speed holder 21B is also held in the neutral position by the elastic force of the second speed switch spring 22B. The engagement of the roller 20 is released, and the 2-speed 2-way roller clutch 16B is also released from the engagement of the roller 20.

  In this state, even if the input shaft 7 is rotated by driving the electric motor 3 shown in FIG. 3, transmission of rotation is interrupted by the first-speed two-way roller clutch 16A and the second-speed two-way roller clutch 16B. The first speed output gear 10 </ b> A and the second speed output gear 10 </ b> B idle, and the rotation of the input shaft 7 is not transmitted to the output shaft 8.

  Next, when the shift mechanism 41 is operated and the shift ring 34 shown in FIG. 12 is moved toward the first-speed output gear 10A, the first-speed friction plate 35A contacts the side surface of the first-speed output gear 10A. The first-speed friction plate 35A rotates relative to the output shaft 8 by the frictional force between the surfaces, and the first-speed retainer 21A that is prevented from rotating by the first-speed friction plate 35A resists the elastic force of the first-speed switch spring 22A. The roller 20 held by the first-speed holder 21A is pushed into the narrowed portion of the wedge-shaped space S between the cylindrical surface 17 and the cam surface 19 and engaged. Become.

  In this state, the rotation of the first-speed output gear 10A is transmitted to the output shaft 8 via the first-speed two-way roller clutch 16A, and the rotation of the output shaft 8 is transmitted to the axle 58 via the differential 6. As a result, in the electric vehicle EV shown in FIG. 1, the front wheels 1 as drive wheels are rotationally driven, and in the hybrid vehicle HV shown in FIG. 2, the rear wheels 2 as auxiliary drive wheels are rotationally driven.

  Next, when the shift ring 34 is moved in the axial direction from the first speed shift position to the second speed shift position by the operation of the shift mechanism 41, the frictional force between the contact surfaces of the first speed friction plate 35A and the first speed output gear 10A. Therefore, the first-speed retainer 21A is moved from the engagement position to the neutral position by the elastic force of the first-speed switch spring 22A, and the first-speed two-way roller clutch 16A is engaged by the movement of the first-speed retainer 21A. Is released.

  When the shift ring 34 reaches the 2nd speed shift position, the 2nd speed friction plate 35B is pressed by the shift ring 34 and comes into contact with the side surface of the 2nd speed output gear 10B. The second-speed retainer 21B that rotates relative to the output shaft 8 and is prevented from rotating by the second-speed friction plate 35B moves from the neutral position to the engagement position against the elastic force of the second-speed switch spring 22B. The roller 20 held by the speed holder 21 </ b> B is pushed into and engaged with the narrowed portion of the wedge-shaped space S between the cylindrical surface 17 and the cam surface 19.

  In this state, the rotation of the 2-speed output gear 10B is transmitted to the output shaft 8 via the 2-speed 2-way roller clutch 16B, and the rotation of the output shaft 8 is transmitted to the axle 58 via the differential 6.

  Similarly, by shifting the shift ring 34 in the axial direction from the 2nd gear shift position to the 1st gear shift position, the engagement of the 2nd gear 2 way roller clutch 16B is released and the 1st gear 2 way roller clutch 16A is engaged. Can be combined.

  When the first-speed two-way roller clutch 16A is disengaged, if torque is transmitted via the first-speed two-way roller clutch 16A, the torque causes the roller 20 to move between the cylindrical surface 17 and the cam surface 19. Acting to push into the narrowed portion of the wedge-shaped space S between the two, the disengagement of the first-speed two-way roller clutch 16A is prevented. Therefore, when the shift ring 34 starts to move in the axial direction from the first speed shift position SP1f to the second speed shift position SP2f by the operation of the shift mechanism 41, the first speed friction plate 35A is moved to the side surface of the first speed output gear 10A. There is a possibility that the engagement of the first-speed two-way roller clutch 16A is not released even though it has already separated from the initial position.

  Therefore, in order to reliably disengage the first-speed two-way roller clutch 16A, not only the first-speed friction plate 35A is separated from the side surface of the first-speed output gear 10A by the operation of the shift mechanism 41, but also the electric It is necessary to change the torque transmitted between the input shaft 7 and the output shaft 8 by controlling the output of the motor 3. The same applies when the second-speed two-way roller clutch 16B is disengaged.

  Therefore, in the above control system, the electric motor 3 and the gear change actuator 47 are controlled by the gear change control device shown in FIG. 9, and the engagement of the first-speed two-way roller clutch 16A or the second-speed two-way roller clutch 16B is controlled by this control. The reliability of the operation when releasing the connection is secured.

According to the speed change control method described above, the drive torque or regenerative torque of the electric motor 3 is gradually unloaded, in other words, the motor torque is not unloaded at once, but unloaded in stages over time. The torsional vibration between the electric motor 3 and the transmission 5 or between the transmission 5 and the tire can be reduced regardless of whether the roller clutches 16A and 16B at the current gear stage are engaged or not.
The switching process is executed when the shift range of the shift operation member of the vehicle is selected from any one of a drive range, a second speed range, and a first speed range. In this case, it is possible to reduce the torsional vibration of the vehicle that may occur, for example, when the accelerator pedal 63 is switched between ON and OFF while the vehicle is running under torque control with any range selected.

  The roller clutch moving process includes a torque gradually outputting process for gradually outputting the torque of the electric motor 3 to a predetermined torque threshold. In this way, the motor torque is output stepwise over time until reaching the torque threshold, so that the roller clutches 16A and 16B at the current gear stage are moved from the driving side to the non-driving side by the rotational speed control. Vehicle torsional vibration can be reduced during the clutch movement process.

The switching process includes a roller clutch moving process for moving the roller clutches 16A and 16B of the current gear stage from the non-driving side to the driving side by rotation speed control when switching from the regeneration control to the creep control. During the movement process, the electric motor 3 is set so that the target rotational speed of the electric motor 3 is the rotational speed obtained by multiplying the output shaft rotational speed by the reduction gear ratio of the current gear and a certain rotational speed threshold value. To drive.
The roller clutch moving process includes a torque gradually outputting process for gradually outputting the torque of the electric motor 3 to a predetermined torque threshold. In this way, the motor torque is output stepwise over time until reaching the torque threshold, so that the roller clutches 16A and 16B at the current gear stage are moved from the non-driving side to the driving side by the rotational speed control. Vehicle torsional vibration can be reduced during the clutch movement process.

  Switching from the regeneration control to the creep control is performed when the vehicle speed is equal to or higher than the first vehicle speed threshold, and switching from the creep control to the regeneration control is performed when the vehicle speed is equal to or lower than the second vehicle speed threshold. May be implemented. In this case, the hunting phenomenon of regenerative control and creep control can be avoided.

DESCRIPTION OF SYMBOLS 3 ... Electric motor 4 ... Motor shaft 5 ... Transmission 7 ... Input shaft 16A, 16B ... Roller clutch 18A, 18B ... Inner ring 19 ... Cam surface 20 ... Roller 21A, 21B ... Cage 23 ... Outer ring 35A, 35B ... Friction plate 40 ... gear ratio switching mechanism 45 ... shift member 47 ... gear change switching actuator 81 ... creep control means 82 ... regeneration control means 87 ... switching means 88 ... gradually unloading means LA, LB ... gear train S ... wedge-shaped space

Claims (8)

Intermittent switching between a gear train of a plurality of gear stages having different gear ratios, an input shaft connected to a motor shaft that is an output shaft of an electric motor for traveling, and a gear train of each gear stage A two-way roller clutch for each gear stage capable of shifting, and a transmission having a gear ratio switching mechanism for switching between on and off of each roller clutch,
Each roller clutch is in a connected state when a roller is interposed in each wedge-shaped space provided between the cam surface of the inner ring and the outer ring, and each roller engages with a narrowed portion of the wedge-shaped space. It is configured to be in a cut state by being positioned in the spread part of the wedge-shaped space,
The transmission ratio switching mechanism is a mechanism that switches contact and separation of a rotating friction plate connected to a retainer with an outer ring by advancing and retreating a shift member by a transmission switching actuator.
In a shift control method for an electric vehicle,
A creep control process for performing creep control for driving the electric motor at the threshold when the torque command value to the electric motor is below a predetermined threshold;
A regenerative control process for performing regenerative control for regenerating the electric motor;
A switching process for switching the creep control and the regeneration control to each other;
Including
In the switching process, when switching from the creep control to the regenerative control or from the regenerative control to the creep control, the torque of the electric motor is set to a predetermined torque threshold from the time when a command for regenerative control or creep control is issued. A shift control method for an electric vehicle characterized by including a gradual unloading process of gradually unloading until the vehicle is unloaded.   2. The electric vehicle according to claim 1, wherein the switching process is executed when the shift range of the shift operation member of the vehicle is selected from any one of a drive range, a second speed range, and a first speed range. Shift control method.   3. The roller clutch moving process according to claim 1, wherein the switching process is such that when switching from the creep control to the regenerative control, the roller clutch of the current gear stage is moved from the driving side to the non-driving side by rotation speed control. In this roller clutch movement process, the target rotational speed of the electric motor is set to a rotational speed obtained by subtracting a constant rotational speed threshold from a rotational speed obtained by multiplying the output shaft rotational speed by the reduction ratio of the current gear stage, A shift control method for an electric vehicle for driving the electric motor.   4. The shift control method for an electric vehicle according to claim 3, wherein the roller clutch moving process includes a torque gradually outputting process in which the torque of the electric motor is gradually output to a predetermined torque threshold.   5. The switching process according to claim 1, wherein when the regenerative control is switched to the creep control, the switching clutch moves the roller clutch of the current gear stage from the non-driving side to the driving side by rotation speed control. In this roller clutch movement process, a constant rotation speed threshold is added to the rotation speed obtained by multiplying the target rotation speed of the electric motor by the output shaft rotation speed and the reduction ratio of the current gear stage. An electric vehicle speed change control method for driving the electric motor as the number of rotations.   6. The shift control method for an electric vehicle according to claim 5, wherein the roller clutch moving process includes a torque gradually outputting process in which the torque of the electric motor is gradually output to a predetermined torque threshold.   The switching from the regeneration control to the creep control is performed when the vehicle speed is equal to or higher than a first vehicle speed threshold, and the creep control is switched to the regeneration control. The switching is a shift control method for an electric vehicle that is performed when the vehicle speed is equal to or lower than a second vehicle speed threshold. Intermittent switching between a gear train of a plurality of gear stages having different gear ratios, an input shaft connected to a motor shaft that is an output shaft of an electric motor for traveling, and a gear train of each gear stage A two-way roller clutch for each gear stage capable of shifting, and a transmission having a gear ratio switching mechanism for switching between on and off of each roller clutch,
Each roller clutch is in a connected state when a roller is interposed in each wedge-shaped space provided between the cam surface of the inner ring and the outer ring, and each roller engages with a narrowed portion of the wedge-shaped space. It is configured to be in a cut state by being positioned in the spread part of the wedge-shaped space,
The transmission ratio switching mechanism is a mechanism that switches contact and separation of a rotating friction plate connected to a retainer with an outer ring by advancing and retreating a shift member by a transmission switching actuator.
In a shift control device for an electric vehicle,
A creep control means for performing creep control for driving the electric motor at the threshold value when a torque command value to the electric motor falls below a predetermined threshold value;
Regenerative control means for performing regenerative control for regenerating the electric motor;
Switching means for switching the creep control and the regeneration control to each other;
Including
When the switching means switches from the creep control to the regenerative control or from the regenerative control to the creep control, the switching means sets the torque of the electric motor from a predetermined torque threshold value when a command for regenerative control or creep control is issued. A shift control apparatus for an electric vehicle, characterized by comprising gradually unloading means for gradually unloading until the vehicle is unloaded.

Images