JP2012091643A - Driving force distribution device for four-wheel drive vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving force distributing device for a four-wheel drive vehicle, which avoids shift operation caused during the operation of a friction clutch.SOLUTION: A control device 70 performs shift operation and transmission torque adjustment by controlling normal or reverse rotation of a motor on the basis of a signal from a position detection unit 65. The control device 70 performs voltage-time integration when a motor applying voltage is a voltage in a shift direction, and makes a current flow in a friction clutch driving direction in a motor 61, when its voltage-time integration value exceeds a predetermined threshold, and thereby, a motor rotation direction is reversed, and the voltage-time integration value is reset to zero, when there is a change exceeding the predetermined threshold in the signal from the position detection unit 65.

Description

  The present invention relates to a driving force distribution device suitably used for a four-wheel drive vehicle.

  As an example of the driving force distribution device, for example, a driving force distribution device for a four-wheel drive vehicle that controls switching of the sub-transmission and clutch pressing force of the friction clutch with a single actuator has been proposed (for example, Patent Documents). 1).

  The driving force distribution device for a four-wheel drive vehicle described in Patent Document 1 includes an action plate that moves in the axial direction of the first output shaft via a conversion mechanism that converts the rotational motion of the actuator into linear motion. The transmission torque of the friction clutch is controlled by the pressing operation of the action plate.

JP 2004-249974 A

  In this type of driving force distribution device for a four-wheel drive vehicle, the deviation between the current actuator rotation position where the rotation position of one actuator is detected by a pulse sensor and the actuator rotation position corresponding to the torque to be transmitted by the friction clutch. In general, the pressing load of the friction clutch is controlled based on the deviation. When this driving force distribution control is, for example, in the four-wheel drive auto mode, if the pulse change from the pulse sensor cannot be recognized and the torque command from the vehicle becomes smaller than the current torque, the friction clutch is not operated. The direction in which the torque is reduced, that is, the actuator continues to rotate in the reverse rotation direction. If this state continues, a shift operation occurs during the operation of the friction clutch. Therefore, it is necessary to avoid this abnormal state.

  An object of the present invention is to provide a driving force distribution device for a four-wheel drive vehicle that can avoid a shift operation that occurs during operation of a friction clutch.

[1] The present invention relates to a sub-transmission mechanism that transmits power to the input shaft to at least two stages of high speed and low speed and transmits the power to the main output shaft, and a friction clutch that transmits power of the main output shaft to the sub-output shaft. An actuator composed of a motor and a speed reducer, and a rotation drive member that selectively performs a shift operation for switching the sub-transmission mechanism or a transmission torque adjustment of the friction clutch by continuous rotation of the actuator. A position detector for detecting the rotational position of the motor, and controlling the forward / reverse rotation of the motor based on a signal from the position detector, whereby the shift operation and the transmission torque are transmitted via the rotational drive member. A control device that performs adjustment, the control device performs time integration of the voltage of the motor, and the voltage of the motor is adjusted while the friction clutch is operating. When the voltage is in the shift direction of the speed mechanism and the time integral value of the voltage exceeds a predetermined threshold value, a current in the friction clutch driving direction is passed through the motor to reverse the rotation direction of the motor. A four-wheel drive vehicle driving force distribution device is characterized in that when the signal from the position detector changes beyond a predetermined threshold, the time integral value of the voltage is reset to zero.
[2] In the invention described in [1], an evaluation function formed as a function of a magnitude of a voltage in the reverse rotation direction of the motor with respect to the application time of the motor is provided, and the voltage applied to the motor is evaluated. It is characterized by time integration after conversion by a function.
[3] In the invention described in [2] above, the evaluation function lowers the evaluation with respect to a minute reverse voltage.
[4] In the invention described in [1] or [2] above, when the time integration value of the voltage exceeds the predetermined threshold before the signal from the position detector reaches the predetermined threshold In addition, the shift operation and the transmission torque adjustment are performed by adjusting the motor current, and backup control is performed.
[5] In the invention described in [4] above, a motor current setting map formed as a function representing a correspondence relationship between the transmission torque of the friction clutch and a motor current is provided, and the motor current setting map is referred to. Then, the motor current to be supplied based on the target transmission torque is obtained, and the motor current is adjusted so as to flow to the motor.
[6] In the invention described in [5] above, the relationship between the transmission torque of the friction clutch and the motor current has a different relationship between when the target torque is in the increasing direction and when the target torque is in the decreasing direction. To do.
[7] In the invention according to the above [4], the backup control is configured such that the current in the friction clutch driving direction is once passed for a predetermined time, then the current in the shift direction is supplied for a predetermined time, and then again in the friction clutch driving direction. The shift operation is performed by flowing a current of.

  According to the present invention, it is possible to efficiently control with high accuracy to avoid the shift operation that occurs during the operation of the friction clutch.

It is sectional drawing which shows schematically the internal structure of the transfer for four-wheel drive vehicles which is typical embodiment concerning this invention. It is a block block diagram for demonstrating the control system comprised by the control apparatus of FIG. It is a block block diagram of the clutch controller of FIG. It is a figure for demonstrating operation | movement of the clutch controller of FIG. It is a block block diagram of the motor controller of FIG. It is a figure for demonstrating operation | movement of the motor controller of FIG. It is a figure for demonstrating other operation | movement of the clutch controller of FIG. It is a figure for demonstrating an example of the processing content of a backup operation function.

  Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

(Overall configuration of transfer)
In FIG. 1, reference numeral 1 indicating the whole schematically shows the overall configuration of a typical transfer according to this embodiment. The transfer 1 according to the illustrated example is applied to, for example, a four-wheel drive (4WD) vehicle based on an FR (front engine, rear drive) system.

  As shown in FIG. 1, the transfer 1 has a transfer case including a front case 2 and a rear case 3. An input shaft 4 for inputting rotation from an engine (not shown) via an automatic transmission or a manual transmission (not shown) is fixedly supported by a front portion of the front case 2 via a bearing 5 so as to be rotatable. Yes. A rear wheel output shaft 6, which is a main output shaft coaxially disposed in the rear case 3, is directly connected to the input shaft 4 via an auxiliary transmission 20 coaxially disposed in the front case 2. Yes.

  As shown in FIG. 1, a front wheel output shaft 7 serving as a sub output shaft with respect to the main output shaft is provided at a portion parallel to the rear wheel output shaft 6 of the transfer case. A drive sprocket gear 8 is provided on the same axis of the rear wheel output shaft 6. A driven sprocket gear 9 for the drive sprocket gear 8 is provided on the same axis of the one front wheel output shaft 7. An annular chain 10 is wound around the drive sprocket gear 8 and the driven sprocket gear 9.

  As shown in FIG. 1, the sub-transmission 20 switches the driving speed of the engine input to the input shaft 4 between a high speed stage H and a low speed stage L by a shift device 30. The shift device 30 is connected to the clutch sleeve 11 for HL switching arranged coaxially with the planetary gear mechanism of the auxiliary transmission 20.

  As shown in FIG. 1, this planetary gear mechanism meshes with the high speed gear (sun gear) 21 formed on the outer periphery of the input shaft 4, the ring gear 22 fixed to the front case 2, and the outer periphery of the sun gear 21. , 23 are provided with a plurality of pinion gears (planetary gears) 23 that mesh with the inner periphery of the ring gear 22. The plurality of pinion gears 23 are fixedly supported so as to be capable of rotating on a circular carrier case 25 via a support shaft 24 arranged with the same phase difference. The carrier case 25 is fixedly supported around the input shaft 4 so as to be rotatable relative to the sun gear 21. A circular ring body 26 having an inner spline (tooth portion) 26 a is integrally fixed to the rear end portion of the carrier case 25, and both ends of the support shaft 24 are connected to the carrier case 25 and the circular ring body 26. The support is fixed.

  In the low speed state, the spline of the clutch sleeve 11 is detached from the high speed gear 21 so that the spline of the clutch sleeve 11 is spline engaged with the inner spline 26a of the ring body 26, and the rotational power transmitted from the pinion gear 23 is It is transmitted to the rear wheel output shaft 6 as a low-speed rotational driving force.

  On the other hand, in the high speed state shown in FIG. 1, the spline of the clutch sleeve 11 and the high speed gear 21 are engaged with each other, and the rotational driving force of the input shaft 4 is converted from the input shaft 4 as a high speed rotational driving force. It is transmitted to the rear wheel output shaft 6 via the drive sprocket gear 8, the front wheel drive chain 10, and the driven sprocket gear 9.

  On the same axis of the rear wheel output shaft 6, as shown in FIG. 1, a friction clutch device 40 that constitutes a driving force distribution device that performs distribution control of front and rear wheel driving force in the 4WD mode is provided. The transfer case is provided with a single actuator 60 serving as a drive source for controlling the operation of the shift device 30 of the auxiliary transmission 20 and the operation of the friction clutch device 40 that functions as a torque distribution clutch. The actuator 60 includes a motor 61 and a speed reducer 62 that amplifies the motor torque.

  The rotation drive by the actuator 60 is performed by rotating the rotation drive member 56 that individually rotates and drives the shift cam 32 that linearly moves the shift device 30 along the shift rod 31 and the plate cam 55 that changes the clutch pressing force of the friction clutch 41. To the shift device 30 and the friction clutch device 40. According to the illustrated example, a drive command signal is output to the motor 61 in response to controlling the motor forward / reverse rotation, so that the shift operation of the shift device 30 and the friction clutch device 40 are The disconnection operation is executed individually.

(Configuration of shift device)
As shown in FIG. 1, the shift device 30 is mainly configured by two members in which an HL fork main body 33 and a sliding holder 34 for HL switching are relatively movable via a coil spring 35. One side of the HL fork main body 33 is inserted and supported by the shift rod 31 so as to be movable. A bifurcated fork engaged with the clutch sleeve 11 for HL switching is extended on the other side of the HL fork main body 33. A pair of elongate columnar spring load receiving portions 33a and 33a bulging inward are formed on both sides in the shift rod axial direction on the inner surface of the standing side wall facing both sides in the width direction of the HL fork main body 33, respectively. Yes.

  As shown in FIG. 1, one sliding holder 34 is provided so as to be movable relative to the HL fork main body 33 through a pair of sliding legs 34 a and 34 a that are inserted and supported coaxially with the shift rod 31. It has been. The sliding leg portion 34 a is set to be smaller than the interval between the spring load receiving portions 33 a of the HL fork main body 33. The distance between the pair of sliding leg portions 34 a is set to be approximately equal to the distance between the pair of spring load receiving portions 33 a on both sides in the length direction of the HL fork main body 33.

  As shown in FIG. 1, a pair of circular washers 36, 36 are arranged coaxially with the shift rod 31 on the opposed inner surfaces of the pair of sliding legs 34 a. The washer 36 is formed to have a larger diameter than the distance between the pair of spring load receiving portions 33 a on both sides in the width direction of the HL fork main body 33. The pair of sliding legs 34 a and the washer 36 have both a spring holding function for holding both ends of the coil spring 35 and a spring operating function for operating the coil spring 35. A waiting mechanism for accumulating the shift operation force is formed by the compressive force and restoring force of the coil spring 35 generated by relative movement between the spring load receiving portion 33a of the HL fork main body 33 and the sliding leg portion 34a of the sliding holder 34. .

  As shown in FIG. 1, an arm portion 34 b extending along the shift rod 31 is integrally formed at one end portion of the sliding holder 34 in the length direction. A cylindrical shifter pin 34c protrudes and is supported at the tip of the arm portion 34b. The shifter pin 34c is loosely fitted with a predetermined gap in a slidable manner in a cam groove 32a that converts the rotational motion of the shift cam 32 into a linear motion of the shift device 30. The shifter pin 34c is configured to be disposed closer to the shift cam 32 than the HL fork main body 33 via the arm portion 34b.

  The rotational movement of the shift cam 32 is transmitted to the sliding holder 34 via the shifter pin 34c that moves along the inclined portion of the cam groove 32a, and is converted into a linear movement of the sliding holder 34. This linear motion causes the HL fork main body 33 to linearly move along the shift rod 31 via the coil spring 35. The linear movement of the HL fork main body 33 shifts the clutch sleeve 11 for connecting / disconnecting the driving force between the sun gear 21 and the pinion gear 23 of the sub-transmission 20, thereby switching between high speed and low speed.

(Configuration of friction clutch device)
As shown in FIG. 1, the friction clutch device 40 performs multi-plate friction clutch 41 for intermittently connecting the rear wheel output shaft 6 and the front wheel output shaft 7, and presses and releases the friction clutch 41. A clutch pressing member 42 and a ball cam mechanism 50 that converts the rotational motion of the actuator 60 into a linear motion are provided.

  As shown in FIG. 1, the friction clutch 41 has a large number of clutch plates that transmit torque. The clutch plate is axially movable in a first annular space formed between a clutch drum 43 fixed to the drive sprocket gear 8 and a clutch hub 44 fixed to the outer periphery of the rear wheel output shaft 6. It is supported by. The clutch pressing member 42 is biased in the opening direction of the friction clutch 41 by a return spring 45 provided in the second annular space between the clutch drum 43 and the clutch hub 44, and the shaft is driven by the rotation of the actuator 60. It is moved in the direction.

  As shown in FIG. 1, the ball cam mechanism 50 is composed of a ball cam that adjusts the clutch fastening force of the friction clutch 41 steplessly. The ball cam includes a driving cam plate 51 on the driving side and a reaction cam plate 52 on the reaction force side. The drive cam plate 51 is disposed on the clutch pressing member 42 via a thrust bearing 53 and is rotatably supported on the outer periphery of the rear wheel output shaft 6. A cam follower 54 pivotally supported at the front end portion of the drive cam plate 51 is always in contact with the cam surface of the plate cam 55, and the rotational drive of the actuator 60 is transmitted to the ball cam mechanism 50.

  As shown in FIG. 1, one reaction force cam plate 52 is disposed on a fixing member 57 via a thrust bearing 58 and is rotatably supported on the outer periphery of the rear wheel output shaft 6. A plurality of cam grooves each having an inclined groove shape with a predetermined phase difference are formed on the same circumference with the rotation center as a center on the cam surfaces where the cam plates 51 and 52 face each other. A ball 59 is rotatably held in the cam groove.

  When the friction clutch 41 is fastened, the cam follower 54 of the drive cam plate 51 rotates on the cam surface of the plate cam 55 so that the drive cam plate 51 is driven to rotate with respect to the reaction force cam plate 52. When the drive cam plate 51 is moved in the axial direction of the rear wheel output shaft 6 while being pressed by the ball 59 in the cam groove, the clutch pressing member 42 is pushed forward in the axial direction of the rear wheel output shaft 6 to cause friction. Press the clutch 41. On the other hand, when releasing the engagement of the friction clutch 41, the actuator 60 is rotationally driven in the reverse direction, so that the operation opposite to the above operation is performed. Thereby, the clutch pressing member 42 moves in the axial direction opposite to the above operation.

(Overall configuration of integrated controller)
The main basic configuration according to this embodiment is an integrated controller 70 (hereinafter also referred to as “control device 70”) that controls the shift device 30 and the friction clutch device 40. Therefore, it is needless to say that the present invention is not limited to the components of the transfer 1 configured as described above.

  Referring to FIG. 2, FIG. 2 illustrates a configuration example of a control system of a typical control device 70 according to this embodiment. The control device 70 controls the friction clutch device 40 by applying a voltage in the forward direction of the motor via the motor drive circuit 64 to drive the motor 61 in the forward direction, and applies a voltage in the reverse direction of the motor. Thus, the shift device 30 is controlled by driving the motor 61 in the reverse direction.

  As shown in FIG. 2, the control device 70 includes a clutch controller 72, an auxiliary transmission controller 73, and a motor controller 90. These controllers 70, 72, 73, and 90 are configured to include a microcomputer including a CPU, a RAM, a ROM, an input / output unit 71, and the like, and are stored in the temporary storage function of the backup RAM and the ROM. Signal processing is performed according to the control program.

  As shown in FIG. 2, an up-down rotary encoder 65 that detects rotational driving of the motor 61 is electrically connected to the control device 70. The rotary encoder 65 is a position detector that detects a rotation direction, a rotation position (rotation angle), a rotation speed (number of rotations), and the like. For example, an optical rotary encoder or a magnetic rotary encoder is used.

  The rotary encoder 65 outputs two pulse signals of phase A and phase B that are out of phase with the output shaft 63 of the actuator 60 to the control device 70. Since the phase difference (advance / delay) of the two phases is converted into an up / down pulse and output, the output timing is reversed between the forward rotation and the reverse rotation of the motor 61 so that the rotation direction of the motor 61 can be determined. It has become.

  The driving force distribution ratio to the rear wheel output shaft 6 and the front wheel output shaft 7 by the transfer 1 shown in FIG. 1 is determined by a clutch controller 72 as shown in FIG. The clutch controller 72 inputs information from the operation switch 100 operated by the occupant, various vehicle state sensors 200, and the like, and sets a current (voltage) command value of the motor 61 in response to a torque command from the control device 70. To achieve this, the clutch engagement command value of the friction clutch device 40 is output.

  The vehicle state sensor 200 includes, for example, a steering angle sensor that detects the steering angle of the steering, a vehicle speed sensor that detects the speed of the vehicle, an acceleration sensor that detects lateral acceleration of the vehicle, a front wheel rotation sensor that detects the rotational speed of the front wheels, A rear wheel rotation sensor that detects the rotation speed of the rear wheel, a throttle sensor that detects the throttle opening degree in the engine, an engine rotation sensor that detects the rotation speed of the engine, and the like. As an example of the mode input to the operation switch 100, there are three modes, for example, a 2WD mode, a 4WD auto mode, and a 4WD lock mode.

  When the 2WD mode is selected by the operation switch 100, the transfer 1 is controlled such that all driving force is transmitted to the rear wheel output shaft 6 and no driving force is transmitted to the front wheel output shaft 7. On the other hand, when the 4WD lock mode is selected by the operation switch 100, the transfer 1 is controlled so that the driving force is transmitted to the rear wheel output shaft 6 and the front wheel output shaft 7 at a ratio of, for example, 50:50. . When the 4WD auto mode is selected by the operation switch 100, the distribution of the driving force transmitted to the rear wheel output shaft 6 and the front wheel output shaft 7 is adjusted according to the vehicle state of the vehicle state sensor 200. Transfer 1 is controlled.

  As shown in FIG. 3, the clutch controller 72 has a target torque calculation unit 81, a pulse detection unit 82, a transmission torque estimation unit 83, an addition / subtraction unit 84, and a PID (Proportional Integral Differential) control unit 85. is doing. As shown in FIGS. 3 and 4, the target torque calculator 81 calculates target torques required for the rear wheel output shaft 6 and the front wheel output shaft 7 based on signals from the operation switch 100 and the vehicle state sensor 200. Calculation is performed (step S1 shown in FIG. 4). The pulse detector 82 holds a signal related to the current position information of the motor 61 acquired from the rotary encoder 65 (step S2 in FIG. 4).

  As shown in FIGS. 3 and 4, the transmission torque estimation unit 83 holds a current torque estimation map formed as a function of the estimated torque value with respect to the number of pulses representing the current position information. The transmission torque estimation unit 83 obtains an estimated torque value with respect to the number of pulses by inputting the estimated torque value from the pulse detection unit 82 and referring to the current torque estimation map (step S3 in FIG. 4), and the friction clutch 41 Is output to the minus side of the addition / subtraction unit 84.

  The adder / subtractor 84 obtains a deviation between the target torque of the target torque calculator 81 and the estimated torque of the estimated torque calculator 83 (step S4 in FIG. 4). The PID control unit 85 controls the estimated torque to match the target torque based on the deviation from the addition / subtraction unit 84. In this PID control unit 85, for example, when the target torque-estimated torque is positive, that is, when the deviation is positive, a drive pulse signal is sent to the motor drive circuit 64 to drive the motor 61 in the forward rotation, and when the deviation is negative. Sends a drive pulse signal to the motor drive circuit 64 so as to drive the motor 61 in reverse rotation (step S5 in FIG. 4). The drive and rotation directions of the motor 61 are controlled via the motor drive circuit 64 by the drive pulse signal from the PID control unit 85.

  The sub-transmission controller 73 shown in FIG. 1 receives the control signal from the control device 70, and achieves the current (voltage) command value of the motor 61 with respect to the shift command from the control device 70. The high-speed and low-speed switching command values of the auxiliary transmission 20 are output via

(Pulse abnormality detection and shift prevention emergency processing)
As shown in FIGS. 2 and 5, one motor controller 90 constantly monitors the motor 61 and the up-down rotary encoder 65, and determines an abnormality that determines the state of the motor 61 and the state of the rotary encoder 65. It has a judgment means. This abnormality determination means recognizes the rotation speed, rotation direction, and the like of the motor 61 while the friction clutch device 40 is operating, and determines whether or not an unintended shift operation has occurred based on the recognition result. ing.

  Referring to FIG. 5, a typical motor controller 90 according to this embodiment includes a voltage conversion unit 91 that converts an applied voltage into an evaluation value every predetermined time, and a time integration calculation that performs a time integration calculation process on the evaluation value. And a voltage state determination unit 93 that determines whether or not the time integration value is abnormal as compared with a predetermined threshold value. The voltage conversion unit 91, the time integration calculation unit 92, and the voltage state determination unit 93 constitute a first abnormality determination unit.

  The voltage conversion unit 91 holds a predetermined evaluation function formed as a function of the magnitude of the voltage in the motor reverse rotation direction (shift direction of the auxiliary transmission 20) with respect to the motor application time. When the applied voltage signal is acquired by the voltage converter 91, the voltage in the reverse motor rotation direction (hereinafter referred to as “reverse voltage”) supplied to the motor 61 is evaluated by referring to this evaluation function.

  When the reverse voltage is evaluated using this evaluation function, a weighting process is performed so as to include a function that decreases the evaluation for a minute reverse voltage. In this weighting process for the evaluation function, the function is defined so that the evaluation is low when the reverse voltage is smaller than a predetermined voltage in the reverse rotation direction of the motor. can do. Thereby, it is possible to improve the evaluation of the evaluation function while eliminating a minute reverse voltage, and it is possible to prevent erroneous detection due to the detection of the minute reverse voltage.

  As shown in FIG. 5, the voltage conversion unit 91 converts the reverse voltage detected every predetermined time according to a predetermined evaluation function into an evaluation value, and outputs the evaluation value to the time integration calculation unit 92. The time integration calculation unit 92 performs time integration calculation of the evaluation value in the voltage conversion unit 91 and outputs the result to the voltage state determination unit 93.

  As shown in FIGS. 5 and 6, the voltage state determination unit 93 determines that the time integral value of the reverse voltage in the time integration calculation unit 92 is, for example, an allowable rotation angle for reverse rotation of the motor 61 during operation of the friction clutch (for example, It is determined whether or not a predetermined threshold value (for example, 0.5) corresponding to 20 ° has been exceeded (step S11 shown in FIG. 6).

  As a result of the determination in the voltage state determination unit 93, if the time integral value of the reverse voltage in the time integration calculation unit 92 exceeds a predetermined threshold value, the motor 61 reversely rotates so that the sub-transmission 20 can perform the shift operation. The motor 61 is energized with a predetermined voltage (current) in the forward rotation direction (for example, a positive current of 0.5 A).

  If it is detected by the monitoring control that performs the shift prevention emergency processing that the motor 61 is reversely driven in the shift direction while the friction clutch is operating, the motor 61 is immediately in the friction clutch pressing direction (forward rotation direction). The motor 61 is reversed by applying a current (voltage). The motor 61 is supplied with a current (voltage) necessary for the shift device 30 to keep within a permissible range of the motor rotation angle at which the shift operation does not occur. In order to suppress the heating of the motor 61 by continuous energization, it is preferable to reduce the current (voltage) as the energization time elapses.

  As shown in FIG. 5, the motor controller 90 further includes an integration value reset unit 94 that resets the time integration value of the time integration calculation unit 92, and a pulse counter 95 that counts the two-phase pulses input from the rotary encoder 65. And a pulse number determination unit 96 that monitors the number of pulses based on the change in the number of counts from the pulse counter 95. The integral value reset unit 94, the pulse counter 95, and the pulse number determination unit 96 constitute a second abnormality determination unit that monitors whether the function of detecting a signal from the rotary encoder 65 is normal. .

  This second abnormality determination means occurs at least when the pulse detection function is normal based on the transition of the level of the two pulse signals of phase A and phase B output with a phase difference from the rotary encoder 65. If there is a change equal to or greater than the pulse change (threshold value), it is determined that the rotational displacement of the motor 61 is normal, and the time abnormality calculation unit 92 forcibly resets the time integration value to zero, thereby first abnormality determination means. To prevent it from working.

  As shown in FIGS. 5 and 6, the pulse counter 95 counts the number of pulses of the pulse signal output from the rotary encoder 65 and outputs it to the pulse number determination unit 96. The pulse number determination unit 96 determines whether or not the number of pulses of the pulse signal from the pulse counter 95 has reached a predetermined threshold (for example, a count of 3 or more) (step S12 shown in FIG. 6).

  As a result of the determination by the pulse number determination unit 96, when the pulse number exceeds a predetermined threshold value, that is, when a pulse change equal to or greater than the predetermined threshold value can be recognized, it is determined that the pulse detection function is normal. Based on the determination result, the integration value reset unit 94 forcibly resets the time integration value of the time integration calculation unit 92 to zero (step S13 in FIG. 6). At the same time, the pulse counter 95 is reset to zero (step S14 in FIG. 6), and the number of pulses of the pulse signal is counted again. As a result, when the pulse detection function is normal, the first abnormality determination means prevents erroneous determination.

  On the contrary, if the number of counted pulses does not reach the predetermined threshold value, it cannot be determined that the pulse detection function is normal, so the time integration value of the time integration calculation unit 92 is forcibly reset to zero. Therefore, the abnormality is determined by the determination of the first abnormality determination means. Based on the determination result, backup control of the auxiliary transmission 20 and the friction clutch 40 is performed via the rotation drive member 56 that is linked to the motor 61.

(Backup control)
If the reverse voltage integrated value of the first abnormality determination means exceeds the threshold before the pulse signal from the rotary encoder 65 exceeds the predetermined threshold, the shift prevention emergency process is performed (step shown in FIG. 7). S21) If a predetermined time has elapsed (step S22 in FIG. 7), backup control is performed by adjusting the motor current (step S23 in FIG. 7).

  The clutch controller 72 has a command current setting map (motor current setting map) formed as a function of the motor current with respect to the command torque, as shown in FIG. 8, for backup control when an abnormality occurs in the pulse detection function. 86 is held. This command current setting map 86 has a different relationship between when the friction clutch transmission torque and the motor current are in the torque increasing direction and when in the torque decreasing direction, and the target current representing the target current when the command torque increases. It is basically constituted by a current line T1 and a target current line T2 representing a motor current when the command torque decreases. According to this command current setting map 86, when the command torque increases, the first motor command current is estimated and calculated on the target current line T1, and when the command torque decreases, the second motor current is calculated on the target current line T2. The motor command current is estimated and calculated.

  Adjustment is made so that a current corresponding to the motor command current flows to the motor 61 via the motor drive circuit 64. A shift operation for switching the sub-transmission 20 and a transmission torque adjustment of the friction clutch device 40 are performed via a rotation drive member 56 that is linked to the motor 61.

  When a shift operation is performed by this backup control, a current (voltage) is flowed in the pressing direction (motor rotation direction) of the friction clutch 41 for a predetermined time, and then the shift direction (motor reverse rotation direction) in the auxiliary transmission 20 is performed. ) For a predetermined time. Again, this is achieved by passing a current in the direction of pressing the friction clutch.

(Effect of embodiment)
In the control device 70 according to the embodiment configured as described above, the following effects can be obtained.
(1) When a reverse voltage (voltage that rotates the motor 61 in the shift direction) is applied to the motor 61 while the friction clutch 41 is in operation, the motor 61 is always driven in reverse and the number of rotations is proportional to the voltage. It is characterized by a highly efficient mechanical system. Based on this characteristic, the motor rotation in the shift direction of the auxiliary transmission 20 is grasped by monitoring the magnitude of the reverse voltage and the time integral value of the application time (proportional to the motor rotation angle). If the time integration value of the time integration calculation unit 92 exceeds a threshold value (corresponding to the allowable rotation angle of the motor) while the friction clutch 41 is operating and the motor 61 is rotating in the reverse direction and the pulse remains unchanged. For example, it is determined that there is an abnormal situation, and the motor 61 is immediately forced to flow the current in the driving direction of the friction clutch 41 to reverse the rotation of the motor 61 to reliably prevent the shift operation during the friction clutch operation. can do.
(2) When the friction clutch 41 is in operation, it reacts quickly when a high reverse voltage is applied to the motor 61, and reacts with a time margin when the reverse voltage is low.
(3) By resetting the time integral value (reverse voltage integral value) of the time integral calculation unit 92 to zero every time a pulse change can be confirmed, it is ensured that the reverse voltage integral value exceeds the threshold when the pulse is normal. Can be prevented.
(4) By integrating only a reverse voltage that is greater than or equal to a predetermined value via a predetermined evaluation function in the voltage conversion unit 91, it is possible to prevent erroneous detection that occurs by integrating a minute voltage.

  Although the driving force distribution device for a four-wheel drive vehicle according to the present invention has been described based on the above-described embodiment, the present invention is not limited to the above-described embodiment and illustrated examples, and various modifications can be made without departing from the scope of the invention. It is possible to implement in the embodiment. In the present invention, other embodiments as shown below are possible.

  In the above embodiment, the configuration for detecting the displacement of the motor 61 has been exemplified. However, the present invention is not limited to this, and for example, the rotational position of the speed reducer 62 may be detected.

  In the above embodiment, as the ball cam mechanism 50 that converts the rotational motion of the motor 61 into a linear motion, the cam follower 54 that is rotatably supported at the tip portion of the drive cam plate 51 always contacts the cam surface of the plate cam 55. However, instead of this, for example, a structure in which a gear formed at the tip portion of the drive cam plate and a pinion gear fixed on the actuator output shaft are engaged with each other may be used.

  In the above-described embodiment, the 3WD mode includes a 2WD mode in which only the front wheels or only the rear wheels are driven, a 4WD auto mode in which the driving force between the front and rear wheels is automatically controlled according to the vehicle state, and a 4WD lock mode in which the maximum driving force is maintained. However, the present invention is not limited to this. For example, a configuration having at least a 4WD auto mode or a configuration capable of switching to two modes of 4WD auto mode and 4WD lock mode. It can also be applied to things.

  In the above embodiment, the configuration for controlling the driving force between the front and rear wheels in the FR type 4WD vehicle is exemplified, but the present invention is not limited to this. The present invention is, for example, configured to control the driving force between left and right front wheels or between left and right rear wheels in an FR type 4WD vehicle, between front and rear wheels, between left and right front wheels, or between left and right rear wheels in an FF type 4WD vehicle. The present invention can also be applied to a configuration for controlling the driving force.

  In the above-described embodiment, the case where the control device 70 is applied to the transfer 1 has been described. However, the present invention is not limited to this, and may be provided on various drive transmission paths such as a differential, for example. The control device 70 can be used effectively.

  Each component of the control device 70 is realized by an arbitrary combination of hardware and software centering on an ECU, a memory, a control program for realizing each component, a storage unit for storing the control program, and an external connection interface. Is. As those methods and apparatuses, those skilled in the art will understand that various conventional methods and apparatuses can be used, and are not limited to the above-described embodiments and illustrated examples.

  As is apparent from the above description, the present invention is not limited to the above-described embodiments and illustrated examples, and various design changes can be made within the scope described in each claim. The present invention can also be applied to various vehicles such as work vehicles such as agricultural machinery, construction engineering machinery, and transport machinery, and four-wheel traveling vehicles (ATV) for rough terrain. Can be achieved.

DESCRIPTION OF SYMBOLS 1 Transfer 2 Front case 3 Rear case 4 Input shaft 5 Bearing 6 Rear wheel output shaft 7 Front wheel output shaft 8 Drive sprocket gear 9 Driven sprocket gear 10 Chain 11 Clutch sleeve 20 Sub transmission 21 High speed gear (sun gear)
22 Ring gear 23 Pinion gear (planetary gear)
24 Support shaft 25 Carrier case 26 Ring body 26a Inner spline 30 Shift device 31 Shift rod 32 Shift cam 32a Cam groove 33 HL fork main body 33a Spring load receiving portion 34 Sliding holder 34a Sliding leg portion 34b Arm portion 34c Shifter pin 35 Coil spring 36 Washer 40 Friction clutch device 41 Friction clutch 42 Clutch pressing member 43 Clutch drum 44 Clutch hub 45 Return spring 50 Ball cam mechanism 51 Drive cam plate 52 Reaction force cam plate 53 Thrust bearing 54 Cam follower 55 Plate cam 56 Rotation drive member 57 Fixing member 58 Thrust bearing 59 Ball 60 Actuator 61 Motor 62 Reducer 63 Output shaft 64 Motor drive circuit 65 Rotary encoder 70 Controller 71 Input / output unit 72 Clutch controller 73 Sub-transmission controller 81 Target torque calculation unit 82 Pulse detection unit 83 Transmission torque estimation unit 84 Addition / subtraction unit 85 PID control unit 86 Motor current setting map 90 Motor controller 91 Voltage conversion unit 92 Time integration calculation unit 93 Voltage state determination unit 94 Integration Value reset unit 95 Pulse counter 96 Pulse number determination unit 100 Operation switch 200 Vehicle state sensor

Claims (7)

A sub-transmission mechanism for switching the power to the input shaft to at least two stages of high speed and low speed and transmitting it to the main output shaft;
A friction clutch for transmitting the power of the main output shaft to the sub output shaft;
One actuator composed of a motor and a reducer;
A rotation drive member that selectively performs a shift operation for switching the sub-transmission mechanism or a transmission torque adjustment of the friction clutch by continuous rotation of the actuator;
A position detector for detecting the rotational position of the motor;
A control device for controlling the forward / reverse rotation of the motor based on a signal from the position detector, and performing the shift operation and the transmission torque adjustment via the rotation driving member;
The control device performs time integration of the voltage of the motor, and when the voltage of the motor is a voltage in the shift direction of the auxiliary transmission mechanism during operation of the friction clutch, the time integration value of the voltage is predetermined. When the current in the friction clutch driving direction is caused to flow through the motor when the threshold value is exceeded, the rotation direction of the motor is reversed, and when the signal from the position detector exceeds a predetermined threshold value A zero-reset of the time integral value of the voltage is a four-wheel drive vehicle driving force distribution device. An evaluation function formed as a function of the magnitude of the voltage in the reverse direction of the motor with respect to the application time of the motor,
2. The driving force distribution device for a four-wheel drive vehicle according to claim 1, wherein the applied voltage to the motor is converted by the evaluation function and then integrated over time.   The driving force distribution device for a four-wheel drive vehicle according to claim 2, wherein the evaluation function lowers the evaluation for a minute reverse voltage.   If the time integral value of the voltage exceeds the predetermined threshold before the signal from the position detector reaches the predetermined threshold, the shift operation and the transmission torque are adjusted by adjusting the motor current. 3. The driving force distribution device for a four-wheel drive vehicle according to claim 1, wherein adjustment is performed and backup control is performed. A motor current setting map formed as a function representing a correspondence relationship between the transmission torque of the friction clutch and the motor current;
5. The four-wheel drive vehicle according to claim 4, wherein the motor current to be supplied based on a target transmission torque is obtained by referring to the motor current setting map and adjusted so that the motor current flows to the motor. Drive power distribution device.   6. The driving force distribution for a four-wheel drive vehicle according to claim 5, wherein the relationship between the transmission torque of the friction clutch and the motor current has a different relationship between when the target torque is in the increasing direction and when the target torque is in the decreasing direction. apparatus.   In the backup control, after the current in the friction clutch driving direction is supplied for a predetermined time, the current in the shift direction is supplied for a predetermined time, and the current in the friction clutch driving direction is supplied again to perform the shift operation. 5. The driving force distribution device for a four-wheel drive vehicle according to claim 4,

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