JP2014121225A - Speed control device and speed control method for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed control device and a speed control method for electric vehicles which reduce the synchro time for synchronizing an electric motor and reduce abnormal sounds due to back-lash between gears.SOLUTION: A speed control device for electric vehicles includes present shift stage clutch release means 82, synchro control means 83 and target shift stage clutch engagement means 85. The synchro control means 83 has a gain adjustment portion 83a adjusting the PI control gain used in controlling the revolution speed of an electric motor on the basis of a vehicle speed detected by vehicle speed detection means and a revolution speed detected by revolution speed detection means.

Description

  The present invention relates to a shift control device and a shift control method for an electric vehicle that changes the number of rotations of an electric motor and transmits it to a wheel, and more particularly to a technique for shortening a synchronization time for synchronizing an electric motor and reducing abnormal noise.

  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 transmission, and a differential (differential). For example, a two-way roller clutch is used for switching the gear position of the transmission.

  When this vehicle motor drive device is used, it is possible to use the electric motor in a highly efficient rotational speed and torque region during driving and regeneration by switching the transmission gear ratio according to the running conditions. . In addition, by setting an appropriate gear ratio, the rotational speed of the rotating member of the transmission during high-speed traveling can be reduced, and the power loss of the transmission can be reduced to improve the energy efficiency of the vehicle. An electric vehicle using such a vehicle motor drive device has been proposed (Japanese Patent Application No. 2011-227666).

JP 2004-116467 A

Positive direction: The direction in which the roller clutch is fastened when the electric motor is driven.
Negative direction: When the electric motor is regenerated, the roller clutch is engaged.
Synchro: An approach operation for making the rotation speed of the electric motor coincide with the rotation speed of the target gear by increasing or decreasing the output of the electric motor.

In the above-described prior art, the electric motor is synchronized after the clutch at the current shift stage is released during the shift. Therefore, in order to shorten the synchronization time, it is necessary to rapidly accelerate and decelerate the electric motor.
Shift down: The electric motor needs to be accelerated rapidly.
Shift up: The electric motor must be decelerated rapidly.
In the synchronization of the electric motor, the PI gain (P: Proportional, I: Integral) used for controlling the rotational speed of the electric motor is a constant. For this reason, if the PI gain is set to be large, a phenomenon occurs in which the rotational speed of the target gear stage (the target rotational speed of the synchro) is exceeded. This phenomenon is called overshoot. The overshoot has a problem that abnormal noise is generated due to backlash between the gears. Since the PI gain is set low in order to avoid the overshoot phenomenon, there is a problem that the synchronization time increases.

As another conventional technique, a feedback control PID gain adjustment method has been proposed in a feedback control system for an engine variable nozzle turbine (VNT) (Patent Document 1). This method is a method of changing the feedback PID gain obtained from the deviation to a smaller value when the actual overshoot value with respect to the target value exceeds a predetermined value.
Although this method can suppress overshoot more appropriately, it cannot avoid overshoot.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a shift control device and a shift control method for an electric vehicle capable of shortening a sync time for synchronizing an electric motor and reducing noise caused by backlash between gears. is there.

The shift control apparatus for an electric vehicle according to the present invention includes a plurality of gear stages LA and LB having different gear 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 clutches 16A and 16B of each gear stage that are respectively interposed between the gear trains LA and LB of each gear stage and can be switched intermittently, and the gear shift that performs switching of the clutches 16A and 16B. A transmission 5 having a ratio switching mechanism 40;
The gear ratio switching mechanism 40 is a mechanism that switches between contact and separation of the rotating friction plates 35A and 35B connected to the retainers 21A and 21B with the outer rings 23A and 23B by the shift member 45 being advanced and retracted. is there,
A shift control device for an electric vehicle,
In response to a shift command to the target shift stage, the shift switching actuator 47 operates the shift member 45 to unload the torque of the electric motor 3 and disengage the clutches 16A and 16B at the current shift stage. Current gear stage clutch release means 82,
After the engagement of the clutches 16A and 16B at the current shift stage is released by the current shift stage clutch release means 82, the outer ring 23A of the clutches 16A and 16B at the target shift stage is controlled by controlling the rotational speed of the electric motor 3. , 23B and the synchronization control means 83 for synchronizing so that the rotation speeds of the inner rings 18A, 18B are synchronized,
Target gear stage clutch engagement in which the target gear stage clutches 16A and 16B are engaged by bringing the target gear stage friction plates 35A and 35B into contact with the outer wheels 23A and 23B and controlling the rotational speed of the electric motor 3. Means 85;
Have
Vehicle speed detection means 94 for detecting the vehicle speed, and rotation speed detection means 66 for detecting the rotation speed of the electric motor 3,
The sync control means 83 controls the rotation speed of the electric motor 3 by PI control or PID control based on the vehicle speed detected by the vehicle speed detection means 94 and the rotation speed detected by the rotation speed detection means 66. It is characterized by having a gain adjustment section 83a for adjusting the PI control gain used when controlling the rotational speed.

  According to this configuration, after releasing the engagement of the clutches 16A and 16B at the current gear stage, the sync control means 83 controls the rotation speed of the electric motor 3 to thereby control the outer wheels 23A and 23B of the clutches 16A and 16B at the target gear stage. And synchronize so that the rotational speeds of the inner rings 18A and 18B are synchronized. When synchronizing the electric motor 3, the gain adjustment unit 83 a of the synchronization control means 83 is based on the vehicle speed detected by the vehicle speed detection means 94 and the rotation speed of the electric motor 3 detected by the rotation speed detection means 66. The PI control gain used when controlling the rotation speed of the motor 3 is adjusted. In this way, by optimally setting the PI control gain based on the vehicle speed and the motor speed that change from moment to moment, the overshoot phenomenon of the electric motor 3 is avoided, the synchronization time is shortened, and backlash between the gears is achieved. It is possible to reduce abnormal noise caused by noise.

  A shift ECU 61 is provided that performs a shift determination based on an input signal and issues a command to the shift switching actuator 47 of the transmission 5. The shift ECU 61 defines the PI control gain according to the vehicle speed and the rotational speed. Recording means 84 in which a PI gain control table 84a is recorded, and the gain adjusting unit 83a takes in a PI control gain from the PI gain control table 84a recorded in the recording means 84, and the electric motor 3 may be controlled. By recording the PI gain control table 84a in the recording means 84, the PI control gain can be optimally set based on the vehicle speed and the motor rotation speed. Further, the PI control gain can be easily rewritten as necessary.

The PI gain control table 84a is set for downshifting and upshifting, and each PI gain control table 84a is set with an absolute value of the deviation between the actual rotational speed of the electric motor 3 and the target rotational speed. It may be provided at every interval. By finely setting the PI gain control table 84a in this way, it is possible to further shorten the synchro time regardless of downshifting or upshifting, and to further reduce abnormal noise caused by backlash.
The PI gain control table 84a may be provided at intervals determined with respect to the vehicle speed.
The PI gain control table 84a may be provided at equal intervals or divided into a low speed region, a medium speed region, and a high speed region over the entire vehicle speed.

  The PI gain control table 84a reduces the integral gain as the absolute value of the deviation between the actual rotational speed of the electric motor 3 and the target rotational speed is smaller, and simultaneously decreases the proportional gain, and the larger the absolute value of the deviation is. The integral gain may be increased, and the proportional gain may be increased at the same time. The PI gain control table 84a is optimally set as described above, for example, based on the result of an actual vehicle test or the like, thereby avoiding the overshoot phenomenon of the electric motor 3, reducing the synchronization time and backlash between the gears. The resulting abnormal noise can be further reduced.

The gain adjustment unit 83a may use the adjustment value of the proportional gain in the PI gain control table 84a, and may not use the adjustment value of the integral gain in the PI gain control table 84a. In this case, it is possible to reduce the calculation processing load of the synchronization control means 83.
The gain adjusting unit 83a provides a limit value for each gain operation amount for operating the proportional gain or the integral gain, and when the limit value is exceeded, the gain adjusting unit 83a uses the limit value as the upper limit value. It is also good.

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 type clutch for each gear stage that is interposed between the trains and can be switched intermittently, and a gear ratio switching mechanism that switches the intermittent state of each clutch;
Each of the clutches is engaged when an engagement element is interposed in each wedge-shaped space provided between the cam surface of the inner ring and the outer ring, and each engagement element engages with a narrow portion of the wedge-shaped space. It is configured to be in a cut state by positioning the ligature in the spreading 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.
A shift control method for an electric vehicle,
In response to a shift command to the target shift stage, the shift member is operated by the shift switching actuator, the torque of the electric motor is unloaded, and the engagement of the clutch of the current shift stage is released. Process,
After releasing the engagement of the clutch of the current shift stage in the process of releasing the current shift stage clutch, the rotation speed of the outer ring and the inner ring of the clutch of the target shift stage is synchronized by controlling the rotation speed of the electric motor. The synchro control process to synchronize
A target gear stage clutch engagement process for engaging a clutch of the target gear stage by bringing the friction plate of the target gear stage into contact with the outer ring and controlling the rotational speed of the electric motor;
Have
Vehicle speed detection means for detecting the vehicle speed, and rotation speed detection means for detecting the rotation speed of the electric motor,
The sync control process includes a gain for adjusting a PI control gain used when controlling the rotational speed of the electric motor based on the vehicle speed detected by the vehicle speed detecting means and the rotational speed detected by the rotational speed detecting means. It has an adjustment process.

  According to this method, in the current shift stage clutch release process, the shift member is operated by the shift switching actuator in response to a shift command to the target shift stage. As a result, the torque of the electric motor is unloaded and the engagement of the current gear stage clutch is released. After the current gear stage clutch release process, in the synchro control process, the electric motor is controlled so as to synchronize so that the rotational speeds of the outer and inner rings of the clutch of the target gear stage are synchronized. Thereafter, in the target shift stage clutch engagement process, the target shift stage clutch is brought into contact with the outer ring and the electric motor is controlled in rotational speed to engage the target shift stage clutch.

When synchronizing the electric motor, in the gain adjustment process in the synchronization control process, the rotational speed of the electric motor is controlled based on the vehicle speed detected by the vehicle speed detecting means and the rotational speed of the electric motor detected by the rotational speed detecting means. Adjust the PI control gain used sometimes. Thus, by optimally setting the PI control gain based on the vehicle speed and the motor speed, the overshoot phenomenon of the electric motor can be avoided, the synchronization time can be shortened, and the abnormal noise caused by the backlash between the gears can be reduced. Reduction can be achieved.
The shift control method may be applied to an electric vehicle of a vehicle motor drive device that drives either one of the front and rear wheels of the vehicle or both of the front and rear wheels.
One of the front and rear wheels of the vehicle may be driven by an engine, and the other wheel may be driven by a vehicle motor drive device including a shift control device that implements the shift control method.

  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 type clutch of each gear stage that can be switched intermittently, and a gear ratio switching mechanism that performs switching of the intermittent state of each of the clutches. The mechanism is a gear shift control device for an electric vehicle, which is a mechanism for switching between contact and separation of the rotating friction plate connected to the cage with the shift member by the shift switching actuator. In response to the shift command, the shift member is operated by the shift switching actuator to unload the torque of the electric motor and disengage the clutch of the current shift step. After releasing the engagement of the clutch at the current shift stage by the latch release means and the current shift stage clutch release means, the rotation of the outer and inner rings of the clutch at the target shift stage is controlled by controlling the rotation speed of the electric motor. Synchronization control means for synchronizing the numbers so as to synchronize with each other, and a target shift stage for engaging the clutch of the target shift stage by contacting the friction plate and the outer ring of the target shift stage and controlling the rotation speed of the electric motor. A vehicle speed detecting means for detecting a vehicle speed, and a rotation speed detecting means for detecting the rotation speed of the electric motor, wherein the sync control means is configured to detect the vehicle speed detected by the vehicle speed detecting means. And the rotational speed of the electric motor is controlled by PI control or PID control based on the rotational speed detected by the rotational speed detection means. Having a gain adjustment section that adjusts the PI control gain to be used. For this reason, it is possible to shorten the synchronization time for synchronizing the electric motor, and to reduce noise caused by backlash between the gears.

  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. And a transmission having a two-way type clutch for each gear stage that can be switched intermittently and a gear ratio switching mechanism for switching the intermittent state of each of the clutches. In addition, an engagement element is interposed in each wedge-shaped space provided between the cam surface of the inner ring and the outer ring, and each engagement element engages with a narrowed portion of the wedge-shaped space, so that each engagement element is connected to the wedge-shaped space by a cage. The gear ratio switching mechanism is configured to be in a disconnected state by being positioned in a widened portion of the gear. Cut by A shift control method for an electric vehicle, which is a mechanism for changing, in response to a shift command to a target shift stage, the shift switching actuator is operated by the shift switching actuator to unload the torque of the electric motor. By releasing the engagement of the clutch of the current speed stage, and releasing the engagement of the clutch of the current speed stage in the current gear stage clutch releasing process, and then controlling the rotational speed of the electric motor. A synchronization control process in which the outer ring and the inner ring of the clutch at the target shift stage are synchronized so as to synchronize, and the friction plate and the outer ring of the target shift stage are brought into contact with each other to control the rotation speed of the electric motor. A target gear stage clutch engaging process for engaging a target gear stage clutch, and detecting a vehicle speed detecting means for detecting a vehicle speed and a rotational speed of the electric motor. A rotational speed detection means, and the synchro control process is configured to perform PI control or PID control on the electric motor based on the vehicle speed detected by the vehicle speed detection means and the rotational speed detected by the rotational speed detection means. The rotation speed control is performed, and a gain adjustment process for adjusting a PI control gain used when the rotation speed control is performed is provided. For this reason, it is possible to shorten the synchronization time for synchronizing the electric motor, and to reduce noise caused by backlash between the gears.

1 is a schematic diagram of an electric vehicle to which a shift control device and a shift control method according to an embodiment of the present invention are applied. It is the schematic of the hybrid vehicle to which the same shift control apparatus and the shift control method 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 gear ratio switching mechanism of the motor drive apparatus for vehicles. It is a block diagram which shows schematically the gear shift 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 apparatus of the motor drive apparatus 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 | summary of the speed-change control method. It is a figure which shows the general characteristic of the torque which drives an electric motor at the time of the speed change in the speed change control apparatus and the speed change control method, and each operation time. It is a figure which shows the rotation speed change of the electric motor in the case of performing a downshift using a prior art. It is a figure which shows the rotation speed change of the electric motor in the case of performing a downshift using the transmission control apparatus and transmission control method which concern on one Embodiment of this invention. It is a figure which shows the rotation speed change of the electric motor in the case of performing a shift up using a prior art. It is a figure which shows the rotation speed change of the electric motor in the case of shifting up using the transmission control apparatus and transmission control method which concern on one Embodiment of this invention. It is a figure which shows the example of the table for PI gain control used with the speed-change control apparatus and the speed-change 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 gear ratio switching mechanism of FIG. 4.

  Hereinafter, a shift control device and a shift control method for an electric vehicle according to embodiments of the present invention will be described. 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 shift control device and the shift control method 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 clutches 16A and 16B for each gear stage that can be switched intermittently by interposing the input shaft 7 connected to the motor shaft 4 as a shaft and the gear trains LA and LB for the respective gear stages, respectively, And a gear ratio switching mechanism 40 for switching on and off of the clutches 16A and 16B. As the clutches 16A and 16B, a roller clutch using a roller as an engagement element is applied, but a sprag type clutch using a sprag as an engagement element may be applied. In this example, the clutches 16A and 16B will be described as roller clutches 16A and 16B, respectively.

  The transmission 5 and the transmission ratio switching mechanism 40 will be briefly described here within a range necessary for understanding the transmission control method and the transmission control device, and will be described in detail after the description of the transmission control method and the transmission control 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 each formed of a flat cam surface 19 and an outer ring 23B on the outer periphery of the inner ring 18B having a polygonal outer peripheral surface, 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 transmission ratio switching mechanism 40 is configured to contact and separate the annular friction plates 35 </ b> A and 35 </ b> B connected to the retainers 21 </ b> A and 21 </ b> B of the roller clutches 16 </ b> A and 16 </ b> B from the outer rings 23 </ b> A and 23 </ b> B. This is a mechanism for switching by the shift fork 45, which is a shift member, by the shift switching 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 surfaces of the clutch outer rings 23A and 23B (output gears 10A and 10B). Thus, when the inner rings 18A, 18B with cam surfaces and the outer rings 23A, 23B rotate relative to each other, a frictional force (torque) acts between the friction plates 35A, 35B and the outer rings 23A, 23B, and the cage 21A. , 21B, the roller 20 can be pushed into the narrow 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. 17) allow the center of the cam surface 19 (FIG. 17) 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 rolling between the three members 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 integrated ECU 60 and various signals directly input to the shift ECU 61. The shift ECU 61 performs shift determination based on various input signals, Commands are sent to the gear change actuator 47 and the inverter device 62 of the machine 5.

The transmission ECU 61 has the following functions (1) to (7).
(1) The vehicle speed sensor (vehicle speed detector) 94 and the acceleration sensor 95 receive the vehicle speed and vehicle acceleration / deceleration detection signals, receive the accelerator opening signal from the integrated ECU 60, and determine automatic shift.
(2) When it is determined that the brake is sudden, new automatic shift control and regenerative control are not performed.
(3) If it is determined that the steering wheel is sudden, a new automatic shift is not performed.
(4) The position signal of the shift lever 93 is received from the integrated ECU 60 and the creep control of the electric motor 3 is performed.

(5) A manual transmission function is provided.
(6) 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 rotational speed of the electric motor 3 from the inverter are provided.
(7) 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 control device and the shift control method of this embodiment relate to control in each shift mode of the automatic shift mode and the manual shift mode by the shift ECU 61. The speed change ECU 61 has various function achievement means shown in FIG. 9, which will be described later.

  In FIG. 5, an inverter device 62 is supplied with a direct current from a battery 69 to supply AC motor drive 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 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. When the driver manually operates the shift lever 93, as in the known example, P (parking), R (reverse), N (neutral), D (drive), 2nd speed (second), 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 rotational 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 inverter control circuit 72 acquires an accelerator signal (torque command) and the electric motor rotation number, and generates 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. 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 comparison unit 109 obtains the difference between the speed command of the speed command unit 106 and the actual electric motor rotation number calculated by the speed calculation unit 108, and the control unit 107 performs PID control (proportional integral derivative control) for 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 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 8 to which the shift control method of the above embodiment is applied.
This shift control device for an electric vehicle is a device that implements the shift control method of the above-described embodiment. The shift ECU 61 includes a shift command generation means 81, a current shift speed clutch release means 82, a sync control means 83, a target shift speed. A clutch engaging means 85, a rotation speed / torque control switching means 86, and a ROM 84 as a recording means are provided. The shift ECU 61 outputs a torque command to the inverter control device 62 as torque control for control of the electric motor 3 other than during automatic shift, and switches between torque control and rotation speed control during shift.

The shift command generation means 81 generates a shift command to the target shift stage according to a predetermined rule from the accelerator opening signal, the detected vehicle speed value, and the vehicle acceleration / deceleration. The shift ECU 61 issues this shift command.
In response to the shift command to the target shift stage, the current shift stage clutch release means 82 operates the shift member 45 by the shift switching actuator 47 to contact the friction plates 35A, 35B of the current shift stage and the outer wheels 23A, 23B. Is released, the torque of the electric motor 3 is unloaded by torque control, and the engagement of the roller clutches 16A and 16B at the current gear stage is released.

The sync control means 83 controls the electric motor 3 so as to synchronize so that the rotation speeds of the outer wheels 23A and 23B and the inner rings 18A and 18B of the roller clutches 16A and 16B at the target gear stage are synchronized.
The target gear stage clutch engagement means 85 brings the target gear stage roller clutches 16A and 17B into contact with the target gear stage friction plates 35A and 35B and the outer wheels 23A and 23B, and controls the rotation speed of the electric motor 3. Engage.
The rotational speed / torque control switching means 86 switches the control of the electric motor 3 from rotational speed control to torque control and inputs the torque of the electric motor 3.

  In the ROM 84, a PI gain control table 84a, which will be described later, and other limit values necessary for calculation are recorded in a rewritable manner. The sync control means 83 takes in the PI control gain used for the rotation speed control of the electric motor 3 from the PI gain control table 84a and controls the rotation speed of the electric motor 3 when synchronizing the electric motor 3. That is, the sync control means 83 includes a gain adjustment section 83a, which is a rotation speed detection means for detecting the vehicle speed detected by the vehicle speed sensor 94, which is a vehicle speed detection means, and the rotation speed of the electric motor 3. Based on the rotation speed detected by a certain rotation angle sensor 66, the PI control gain used when the rotation speed of the electric motor 3 is controlled is adjusted.

These shift command generation means 81, current shift speed clutch release means 82, synchro control means 83, target shift speed clutch engagement means 85, and rotation speed / torque control switching means 86 are arranged in steps S1, S2, S3 of FIG. , S4, and S5.
FIG. 10 is a flowchart showing an outline of the shift control method. The execution procedure will be described.
For example, this processing is started by turning on an ignition switch or the like of the vehicle. After the start of this processing, in step S1, the accelerator opening degree, the vehicle speed, and the acceleration / deceleration of the vehicle are detected, and the shift ECU 61 issues a shift command to the target shift stage. Next, the process proceeds to step S2, and in response to the shift command to the target shift stage, the shift member 45 is operated by the shift switching actuator 47, the torque of the electric motor 3 is unloaded, and the roller clutch of the current shift stage. The engagement between 16A and 16B is released (current shift stage clutch release process).

After releasing the engagement of the roller clutches 16A and 16B at the current shift stage in the current shift stage clutch release process, the PI control gain used when controlling the rotation speed of the electric motor 3 at step S3 is set to the vehicle speed. And adjustment based on the motor speed (synchronization control process, gain adjustment process).
Next, in step S4, the friction plates 35A, 35B at the target gear stage and the outer ring 23 are brought into contact with each other, and the rotational speed of the electric motor 3 is controlled to engage the roller clutches 16A, 16B at the target gear stage (target). (Gear stage clutch engagement process). Thereafter, in step S5, the rotational speed / torque control switching means 86 switches the control of the electric motor 3 from rotational speed control to torque control.

FIG. 11 is a diagram showing a schematic characteristic of the torque for driving the electric motor 3 and each operation time during a shift in the shift control device and the shift control method. The shift ECU 61 makes an automatic shift determination when the vehicle travels in the D range (FIG. 7) and issues a command to the shift switching actuator 47 and the inverter device 62 of the transmission 5.
In the shift control method for an electric vehicle in this shift control apparatus, the operation for driving the electric motor 3 is mainly the following operation (1) → operation (5).

The output state of the electric motor torque in the operation (1) → the operation (5) will be described.
Between t0 and t1 (operation (1)): The vehicle is traveling at the current shift stage traveling torque.
The electric motor 3 is driven by torque control in a state where the roller clutch at the current gear stage is engaged in the forward direction. At this time, the torque of the electric motor 3 is transmitted to the drive wheels via the transmission 5 and the differential 6.

Between t1 and t2 (operation (2)): The current gear stage clutch release means 82 in the shift ECU 61 releases the clutch at the current gear stage.
Between t2 and t3 (operation (3)): The sync control means 83 in the speed change ECU 61 synchronizes the electric motor 3.
Between t3 and t4 (operation (4)): The target gear stage clutch engaging means 85 in the speed change ECU 61 engages the clutch of the target speed stage.
t4 → (Operation (5)): The vehicle is traveling at the target shift stage traveling torque.
The electric motor 3 is driven by torque control in a state where the roller clutch of the target gear stage is engaged in the forward direction. At this time, the torque of the electric motor 3 is transmitted to the drive wheels via the transmission 5 and the differential 6.

FIG. 12 is a diagram illustrating a change in the rotational speed of the electric motor when downshifting is performed using the conventional technology. In operation (3) of FIG. 11, it is a change figure of the rotation speed of an electric motor in the case of synchronizing an electric motor by a prior art.
t0 → t1: The number of rotations before the electric motor is synchronized, and the electric motor is rotated at the number of rotations at the current gear position corresponding to the vehicle speed.
t1 → t2: In order to make the rotation speed of the electric motor coincide with the rotation speed of the target gear, the rotation speed of the electric motor is increased by rotation speed control. In order to shorten the synchronization time, the gain of the PI control used for the rotational speed control is set large (the PI gain is a constant). Since the operation increases the rotation speed of the electric motor, the torque command value becomes positive.
t2 → t3: By setting the PI control gain large, the rotational speed of the electric motor exceeds the target rotational speed of the target gear (overshoot). Due to fluctuations in the rotational speed of the electric motor after overshooting, abnormal noise due to backlash between the gears is likely to occur.

FIG. 13 is a diagram illustrating a change in the rotation speed of the electric motor when downshifting is performed using the shift control device and the shift control method according to the embodiment. FIG. 12 is a change diagram of the number of revolutions of the electric motor when the electric motor is synchronized by the transmission control device and the transmission control method according to this embodiment in the operation (3) of FIG. 11.
t0 → t1: The number of rotations before the electric motor is synchronized, and the electric motor is rotated at the number of rotations at the current gear position corresponding to the vehicle speed.
t1 → t2: An operation for shortening the synchronization time by adjusting the PI control gain based on the vehicle speed and the difference rotational speed between the rotational speed of the electric motor and the rotational speed of the target gear.
At t2: The synchronization of the electric motor is completed without overshooting, and the electric motor is rotated at the same rotational speed as the target gear stage. By not overshooting, fluctuations in the number of revolutions of the electric motor are suppressed, and abnormal noise caused by backlash between gears is less likely to occur.

FIG. 14 is a diagram illustrating a change in the rotational speed of the electric motor when the upshift is performed using the conventional technique. In operation (3) of FIG. 11, it is a change figure of the rotation speed of an electric motor in the case of synchronizing an electric motor by a prior art.
t0 → t1: The number of rotations before the electric motor is synchronized, and the electric motor is rotated at the number of rotations at the current gear position corresponding to the vehicle speed.
t1 → t2: In order to make the rotation speed of the electric motor coincide with the rotation speed of the target gear, the rotation speed of the electric motor is decreased by rotation speed control. In order to shorten the synchronization time, the gain of the PI control used for the rotational speed control is set large (the PI gain is a constant). The operation is negative as the torque command value in order to reduce the rotation speed of the electric motor.
t2 → t3: When the PI control gain is set to be large, the rotational speed of the electric motor exceeds the target rotational speed of the target shift stage and overshoots. Due to fluctuations in the rotational speed of the electric motor after overshooting, abnormal noise due to backlash between the gears is likely to occur.

FIG. 15 is a diagram illustrating a change in the rotational speed of the electric motor when the upshift is performed using the shift control device and the shift control method according to the embodiment. FIG. 12 is a change diagram of the number of revolutions of the electric motor when the electric motor is synchronized by the transmission control device and the transmission control method according to this embodiment in the operation (3) of FIG. 11.
t0 → t1: The number of rotations before the electric motor is synchronized, and the electric motor is rotated at the number of rotations at the current gear position corresponding to the vehicle speed.
t1 → t2: An operation for shortening the synchronization time by adjusting the PI control gain based on the vehicle speed and the difference rotational speed between the rotational speed of the electric motor and the rotational speed of the target gear.
At t2: The synchronization of the electric motor is completed without overshooting, and the electric motor is rotated at the same rotational speed as the target gear stage. By not overshooting, fluctuations in the number of revolutions of the electric motor are suppressed, and abnormal noise caused by backlash between gears is less likely to occur.

FIG. 16 is a diagram illustrating an example of a PI gain control table used in the shift control device and the shift control method according to the embodiment. In the operation (3) of FIG. 11, it is necessary to rapidly accelerate and decelerate the electric motor.
Shift down: The electric motor needs to be accelerated rapidly.
Shift up: The electric motor must be decelerated rapidly.
The following contents are for preventing the overshoot phenomenon of the electric motor by PI control.

A normal offset (steady deviation from the target value) is generated only by the P control. For this reason, in order to eliminate the offset of P control, I control is added and the electric motor is controlled until the deviation between the actual measurement value and the target value is eliminated.
Manipulation amount: PI = P + I
Deviation in the number of revolutions of the electric motor: E_ROT = O_ROT−A_ROT
(O_ROT: target rotation speed of electric motor; A_ROT: actual rotation speed of electric motor)
P manipulated variable: P = Kp × E_ROT
I operation amount: I = I + Ki × E_ROT

PI control gain adjustment rules:
1. The integral gain Ki and the proportional gain Kp are decreased as the absolute value | E_ROT | of the deviation between the actual rotational speed of the electric motor and the target rotational speed is smaller.
2. Conversely, the integral gain Ki and the proportional gain Kp are increased as the absolute value | E_ROT | of the deviation between the actual rotational speed of the electric motor and the target rotational speed is larger.
The PI gain control table is created based on the actual vehicle test results according to this adjustment rule.

Two types of PI gain control tables are provided for each of upshifting and downshifting. Each PI gain control table sets PI control gains at regular intervals (for example, 500 rpm, 1000 rpm, 1500 rpm, etc.) of the absolute value | E_ROT | of the deviation between the actually measured rotational speed and the target rotational speed. Further, a table is provided for each vehicle speed at regular intervals (for example, 5 km / h, 10 km / h, 15 km / h, etc.).
Here, in a table in which values are set at regular intervals, at an intermediate | E_ROT | in which the set value is not determined and the vehicle speed, a PI control gain is calculated and determined by linear interpolation from the table set values on both sides. These tables are recorded in the ROM 84.
Further, in this example, the gain adjusting unit 83a sets limit values for the gain operation amount (P operation amount) for operating the proportional gain and the gain operation amount (I operation amount) for operating the integral gain. When the gain adjustment unit 83a exceeds the limit values of the P operation amount and the I operation amount, the gain adjustment unit 83a uses the limit values as upper limit values.

Next, the details of the vehicle motor drive device shown in FIGS. 3 and 4 will be described together with FIGS. 3 and 4 and 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. 17 to 19, 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 has 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 2-speed retainer 21B for holding the roller 20, and a 2-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, the cam surface 19 faces the cylindrical surface 17 as shown in FIG. It is a flat surface.

  As shown in FIGS. 4 and 22, the 2-speed retainer 21 </ b> B includes a cylindrical portion 24 in which a plurality of pockets 21 a that store 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. 18, 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 10 </ 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 10B and the output shaft 8 via the roller 20. Reverse direction torque It is possible to transfer.

  As shown in FIGS. 19 and 22, 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 switch spring accommodating recess 28 which is an annular groove formed in the axial end surface of the second-speed cam member 18B, and the pair of extending portions 27 and 27 are shafts of the second-speed cam member 18B. It is inserted in a radial groove 29 formed in the direction end face.

  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. 19, the position of the notch 30 with respect to the radial groove 29 is shifted in the circumferential direction. 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 22 </ b> B are formed on the inner surface of the radial groove 29 by the elastic restoring force. The inner surface of the notch 30 is 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. As shown in FIG. 17, 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. As shown in FIG. 4, the first speed cam member 18 </ b> A and the second speed cam member 18 </ b> B are not movable in the axial direction by a pair of retaining rings 31 fitted to the outer periphery of the output shaft 8. As shown in FIG. 17, 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 transmission mechanism 33 for transmission.
The transmission mechanism 33 for shifting is provided with a shift ring 34 that is movably provided in the axial direction between the first-speed output gear 10A (the portion not shown in cross section is not shown in FIG. 21) and the second-speed output gear 10B. A first-speed output gear 10 </ b> A and a second-speed friction plate 35 </ b> B incorporated between the shift ring 34 are included.

  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 where it contacts the side surface of the second-speed output gear 10B and a position where it is separated, while being stopped.

  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 through the spacer 32 in a state where the second speed friction plate 35B is in a position separated from the side surface of the second speed output gear 10B. Thus, the second-speed friction plate 35B is prevented from rotating around the output shaft 8, and at this time, the second-speed retainer 21B that 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 obtained by the elastic restoring force of the second speed separation spring 39B. 35B is biased 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 of the second speed separating spring 39B engages with the protruding piece 36 of the second speed friction plate 35B via the second speed washer 90B. Is supported by the axial end surface of the second speed cam member 18B. The 2-speed washer 90B 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. 20 and 21, the shift mechanism 41 includes a shift sleeve 43 that rotatably supports a shift ring 34 (FIG. 4) via a rolling bearing 42, and an annular shape provided on the outer periphery of the shift sleeve 43. A bifurcated shift fork 45 that engages with the groove 44, a shift rod 46 to which the shift fork 45 is fixed, a shift switching actuator 47 that is a shift motor, and the rotation of the shift switching actuator 47 into a linear motion of the shift rod 46. And a motion conversion mechanism 48 (feed screw mechanism or the like) for conversion.

  As shown in FIG. 21, the shift rod 46 is arranged parallel to the output shaft 8 at a distance, 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 transferred to the shift ring 34 (see FIG. 4), the shift ring is moved in the axial direction.

  As shown in FIG. 17, 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. It has a pinion shaft 55 fixed to the differential case 53 in a perpendicular direction, a pair of pinions 56 rotatably supported by the pinion shaft 55, and a 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. 17, 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. 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. 17 is moved toward the first-speed output gear 10A, the first-speed friction plate 35A comes into contact with 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. Therefore, the roller 20 held by the first-speed holder 21A is pushed into the narrowed portion of the wedge-shaped space S (FIG. 18) between the cylindrical surface 17 and the cam surface 19 to engage. Combined state.

  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 (FIG. 18) 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 shift switching actuator 47 are controlled by the shift control device shown in FIGS. 8 and 9, and the first-speed two-way roller clutch 16A or the second-speed two-way roller is controlled by this control. The reliability of the operation when releasing the engagement of the clutch 16B is ensured.

  According to the speed change control apparatus and speed change control method described above, after the clutches 16A and 16B at the current speed are disengaged, the sync control means 83 controls the speed of the electric motor 3 to control the clutch at the target speed. The 16A and 16B outer rings 23A and 23B and the inner rings 18A and 18B are synchronized so that the rotation speeds are synchronized. When synchronizing the electric motor 3, the gain adjusting unit 83 a of the synchronization control unit 83 rotates the electric motor 3 based on the vehicle speed detected by the vehicle speed sensor 94 and the motor rotation speed detected by the rotation angle sensor 66. The PI control gain used when performing numerical control is adjusted. In this way, by optimally setting the PI control gain based on the vehicle speed and the motor speed that change from moment to moment, the overshoot phenomenon of the electric motor 3 is avoided, the synchronization time is shortened, and backlash between the gears is achieved. It is possible to reduce abnormal noise caused by noise.

The gain adjustment unit 83 a takes in the PI control gain from the PI gain control table 84 a recorded in the ROM 84 and controls the electric motor 3. Thus, by recording the PI gain control table 84a in the ROM 84, the PI control gain can be optimally set based on the vehicle speed and the motor rotation speed. Further, the PI control gain can be easily rewritten as necessary.
The PI gain control table 84a is set for each of the downshift and the upshift, and each PI gain control table 84a has a predetermined interval between absolute values of deviations between the actual rotational speed of the electric motor 3 and the target rotational speed. Provided for each. By finely setting the PI gain control table 84a in this way, it is possible to further shorten the synchro time regardless of downshifting or upshifting, and to further reduce abnormal noise caused by backlash.

The PI gain control table 84a may be provided at equal intervals over the entire vehicle speed or divided into a low speed region, a medium speed region, and a high speed region.
The gain adjustment unit 83a may use only the adjustment value of the proportional gain in the PI gain control table 84a, and may not use the adjustment value of the integral gain in the PI gain control table 84a. In this case, it is possible to reduce the calculation processing load of the synchronization control means 83.

DESCRIPTION OF SYMBOLS 3 ... Electric motor 4 ... Motor shaft 5 ... Transmission 7 ... Input shaft 16A, 16B ... Clutch 18A, 18B ... Inner ring 19 ... Cam surface 20 ... Roller (engagement element)
21A, 21B ... Retainer 23A, 23B ... Outer ring 35A, 35B ... Friction plate 40 ... Gear ratio switching mechanism 45 ... Shift fork (shift member)
47... Gear change switching actuator 66... Rotation angle sensor (rotational speed detection means)
82 ... Current gear stage clutch release means 83 ... Synchro control means 83a ... Gain adjustment section 84 ... ROM (recording means)
84a ... PI gain control table 85 ... target gear stage clutch engaging means 94 ... vehicle speed sensor (vehicle speed detecting 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 And a transmission having a two-way clutch for each shift stage capable of shifting, and a gear ratio switching mechanism for switching between on and off of each clutch,
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.
A shift control device for an electric vehicle,
In response to a shift command to the target shift stage, the shift member is operated by the shift switching actuator, the torque of the electric motor is unloaded, and the engagement of the clutch of the current shift stage is released. Means,
After releasing the clutch of the current gear stage with the current gear stage clutch release means, the rotation speed of the outer ring and the inner ring of the clutch of the target gear stage is synchronized by controlling the rotation speed of the electric motor. Synchronization control means for synchronizing to,
Target gear stage clutch engagement means for engaging the clutch of the target gear stage by bringing the friction plate of the target gear stage into contact with the outer ring and controlling the rotational speed of the electric motor;
Have
Vehicle speed detection means for detecting the vehicle speed, and rotation speed detection means for detecting the rotation speed of the electric motor,
The synchronization control means controls the rotational speed of the electric motor by PI control or PID control based on the vehicle speed detected by the vehicle speed detection means and the rotational speed detected by the rotational speed detection means. A shift control device for an electric vehicle comprising a gain adjustment unit for adjusting a PI control gain used when controlling the rotational speed.   2. The shift control apparatus for an electric vehicle according to claim 1, further comprising a shift ECU that performs a shift determination based on an input signal and issues a command to the shift switching actuator of the transmission. Recording means for recording a PI gain control table that defines the PI control gain in accordance with the number, and the gain adjustment unit is configured to obtain a PI control gain from the PI gain control table recorded in the recording means. And an electric vehicle shift control device for controlling the electric motor.   3. The shift control apparatus for an electric vehicle according to claim 2, wherein the PI gain control table is set for downshifting and upshifting, and the PI gain control table is set for the actual rotational speed and target of the electric motor. A speed change control device for an electric vehicle, which is provided at predetermined intervals of an absolute value of a deviation in rotational speed.   4. The shift control device for an electric vehicle according to claim 2, wherein the PI gain control table is provided at intervals determined with respect to a vehicle speed.   5. The shift control device for an electric vehicle according to claim 4, wherein the PI gain control table is provided at equal intervals or divided into a low speed region, a medium speed region, and a high speed region over the entire vehicle speed.   6. The shift control apparatus for an electric vehicle according to claim 2, wherein the PI gain control table has a smaller absolute value of a deviation between the actual rotational speed of the electric motor and the target rotational speed. 7. A shift control apparatus for an electric vehicle that decreases an integral gain, simultaneously decreases a proportional gain, increases the integral gain as the absolute value of the deviation increases, and simultaneously increases the proportional gain.   The shift control apparatus for an electric vehicle according to any one of claims 2 to 6, wherein the gain adjustment unit uses an adjustment value of a proportional gain in the PI gain control table to control the PI gain. A shift control apparatus for an electric vehicle that does not use the adjustment value of the integral gain in the table.   The shift control device for an electric vehicle according to any one of claims 1 to 7, wherein a limit value is provided for each gain operation amount for operating a proportional gain or an integral gain by the gain adjusting unit, and the limit value is set. If the value exceeds the upper limit, the gain adjustment unit uses the limit value as the upper limit value.

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