JP4572858B2 - Shift-by-wire range switching device - Google Patents

Description

  The present invention relates to a shift-by-wire range switching device, and more particularly to a shift-by-wire range switching device that can reliably pull a drive shaft into a range valley of a detent mechanism.

  Conventionally, as described in Patent Document 1, a range switching device for a shift-by-wire automatic transmission is known. This range switching device includes a range selection means for selecting a shift range by a driver, a motor controlled by a control signal based on an input signal from the range selection means, and a transmission means for transmitting the rotation of the motor to the range switching means. And position detecting means for detecting the position of the range switching means.

  In this type of range switching device, a detent mechanism is used to position and hold the range switching means switched to the position corresponding to the shift range selected by the range selection means at the switching position. A detent lever and an engaging member biased by a detent spring are provided, and the detent lever is provided with a range groove corresponding to four switching positions (P position, R position, N position, D position) of the range switching means. The engaging members are engaged with the range grooves to hold the switching position of the switching means.

  The position detecting means is generally composed of a potentiometer or the like, and detects the rotation angle of the manual shaft. When the shift range is changed to the P position, D position, etc. due to the rotation of the manual shaft, it can be detected by the output of a potentiometer or the like. May cause the N point of the potentiometer to deviate from the N point of the manual shaft, and the shift position may deviate slightly from the design value due to variations in the accuracy of the potentiometer itself.

For this reason, as described in Patent Document 2, the learning means learns the relationship between each shift position and the output value of the potentiometer, and this learning function absorbs the assembled play and the like of the potentiometer itself. There has also been proposed a system that can perform an accurate shift regardless of accuracy variations.
JP 2005-69295 A JP 2002-48230 A

  However, in the thing of the above-mentioned patent document 2, since learning of each shift position is performed only at the time of shift execution, there is a problem that it cannot cope with changes in sensor characteristics due to temperature drift after the shift or the like. . Furthermore, even if the manual shaft is securely pulled into the recess of the detent mechanism by the shift operation, the manual shaft may be displaced from the recess of the detent mechanism due to the influence of vibration or the like. Switching to an unintended shift position or the starting angle of the motor at the next shift execution is different from the original angle. For this reason, the time from the start of the motor to the start of braking becomes longer, shorter, or fluctuates, and the shift switching accuracy may be lowered.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a shift-by-wire range switching device that can reliably pull the drive shaft into the range valley of the detent mechanism. is there.

In order to solve the above-mentioned problem, the invention according to claim 1 drives a motor based on an electric signal from a range selection means capable of selecting a plurality of shift ranges, and rotates the motor via a transmission mechanism. In the range switching device, wherein the detent mechanism detects the switching position of the range switching means, the position detecting means for detecting the switching position of the range switching means. mechanism have a engaging member that engages with the detent lever and the range valleys plurality of range valleys are formed corresponding to the shift range, the motor is driven based on the electric signal from the range selection means after stopping, after a predetermined time has elapsed from the stop of the motor, the engaging portion to the range valley of the detent lever, based on the switching position Has a pull-determining means for determining whether is retracted,
Based on the determination result of the pull-in determination unit, the motor has a pull-in execution unit that outputs a torque smaller than the torque generated from the urging force acting on the engagement member to rotate the motor forward or backward. It is characterized by.

According to a second aspect of the present invention, in the first aspect , the pull-in determination means compares the switching position before and after the motor is rotated forward or reverse, and the engaging member is pulled into the range valley. It is characterized by determining whether or not it is rare.

According to a third aspect of the present invention, in the first or second aspect , the pull-in execution unit rotates the motor forward or reverse until the switching position does not change.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the learning function for learning the switching position based on the switching position before and after the execution of the valley position drawing means. It is characterized by having.

According to a fifth aspect of the present invention, in the fourth aspect , the learning function is configured to execute the valley position drawing means when a difference between the switching position before and after the execution of the valley position drawing means is equal to or less than a predetermined value. The previous switching position is updated based on the switching position after execution of the valley position retracting means, and the motor is driven based on the updated switching position.

The invention described in claim 6 is characterized in that, in claim 5 , the learning function updates only the switching position executed by the valley position drawing means.

According to a seventh aspect of the present invention, in the fifth aspect , the learning function updates the switching position where the valley position drawing means is not executed based on the switching position where the valley position drawing means is executed. It is characterized by this.

According to the first aspect of the present invention, the pull-in determination means for determining whether or not the engaging member is pulled into the range valley of the detent lever based on the switching position after a predetermined time has elapsed from the stop of the motor, and the pull-in determination Since it has a pulling execution means for rotating the motor forward or backward based on the determination result of the means, it is possible to accurately determine whether or not the drive shaft is pulled into the range valley of the detent mechanism, and it is pulled into the range valley If not, it can be reliably pulled into the range valley.
Moreover, since the motor is rotated forward or reverse by a torque smaller than the torque generated from the biasing force acting on the engagement member for a predetermined time in the forward rotation direction and the reverse rotation direction, It can be reliably operated only in the direction of pulling into the range valley of the detent lever.

According to the invention of claim 2 , the switching position before and after the motor is rotated forward or reverse is compared, and it is determined whether or not the engaging member is pulled into the range valley. Therefore, it is possible to easily and surely determine whether or not it is drawn into the range valley by the change in the position signal of the position detecting means.

According to the invention of claim 3 , since the motor is rotated forward or reverse until the switching position does not change, the engagement member can be reliably engaged with the range valley of the detent lever.

According to the fourth aspect of the present invention, since the learning function for learning the switching position based on the switching position before and after the execution of the valley position pulling means is provided, the accuracy characteristics of the position detecting means and the change over time Regardless of this, accurate range switching can be performed.

According to the fifth aspect of the present invention, when the difference between the switching positions before and after the execution of the valley position drawing means is equal to or less than the predetermined value, the switching position before the execution of the valley position drawing means is set after the execution of the valley position drawing means. Since the update is performed based on the switching position, erroneous learning can be prevented when the position detecting means is out of order.

According to the invention of claim 6 , since only the switching position where the valley position drawing means is executed is updated, the relative relationship between the valley positions of each range in the position detection means changes due to temperature drift or the like. In the case of a sensor, accurate range switching can be performed without affecting the sensor learning value at the valley position of another range.

According to the seventh aspect of the invention, since the switching position where the valley position drawing means is not executed is also updated based on the switching position where the valley position drawing means is executed, the valley of each range in the position detection means. In the case of a sensor in which the relative relationship between positions does not change, accurate range switching can be performed without executing valley position pull-in determination in other ranges.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of a shift-by-wire range switching device 10, and FIG. 2 shows a control block of the shift-by-wire range switching device 10. 1 and 2, a shift-by-wire range switching device 10 includes a shift lever 11 as a range selection unit, a vehicle speed sensor 12, a control unit 13, a motor 14, a power transmission unit 15 as a transmission mechanism, and a range switching unit. It comprises a manual valve 16 and a position sensor 17 as position detecting means.

  The shift lever 11 has a P range (parking range) for requesting parking of the vehicle, an R range (reverse range) for requesting reverse travel, an N range (neutral range) for requesting stop, and a D range (requesting forward travel). Characters (P, R, N, D) representing drive range) are displayed. When the driver operates the shift lever 11, one required range is selected, and a shift signal S1 corresponding to the selected required range is input to the control unit 13 configured as described later. In the present embodiment, the shift lever 11 is used as the range selection means. However, if the shift signal S1 corresponding to the requested range selected by the driver can be generated, for example, a selector switch, It may be a shift button, a voice input device, or the like.

  The vehicle speed sensor 12 detects the vehicle speed of the vehicle, and the detected vehicle speed signal V 1 is input to the control unit 13. Further, the position signal P <b> 1 from the position sensor 17 is input to the control unit 13. Based on the shift signal S1, the vehicle speed signal V1, and the position signal P1, the control unit 13 outputs a control signal C1 for controlling the rotation direction of the motor 14 and the timing of starting / stopping the rotation to the motor 14.

  The motor 14 is attached to the outside of the casing 18, and its output shaft is inserted into the casing 18. A DC motor is used as the motor 14 and is driven and controlled by a control signal C 1 output from the control unit 13.

  The power transmission means 15 includes a speed reduction mechanism 20, a ball screw mechanism 21, an arm 23, a manual shaft 24 as a drive shaft, and a detent mechanism 25. The manual shaft 24 is rotatably supported by the casing 18. The reduction mechanism 20 includes a small-diameter spur gear 20 a fixed to the output shaft of the motor 14 and a large-diameter spur gear 20 b that meshes with the spur gear 20 a, and the large-diameter spur gear 20 b is a ball of the ball screw mechanism 21. The screw shaft 26 is fixed. A ball nut 27 of the ball screw mechanism 21 is screwed onto the ball screw shaft 26, and the rotation of the ball nut 27 is restricted by the arm 23. Thus, the rotation of the motor 14 is decelerated by the speed reduction mechanism 20 and transmitted to the ball screw shaft 26, and the rotation of the ball screw shaft 26 is converted into an axial movement of the ball nut 27 by the ball screw mechanism 21.

  The ball nut 27 is engaged with a bifurcated portion of an arm 23 that is integrally fitted to the manual shaft 24, and the arm 23 is integrated with the manual shaft 24 around the manual shaft 24 by the axial movement of the ball nut 27. Rocks.

  The speed reduction mechanism 20, the ball screw mechanism 21 and the arm 23 are accommodated in the casing 18. The manual shaft 24 is housed in the casing 18 at one end and protrudes from the casing 18 at the other end. In the present embodiment, the rotation of the motor 14 is decelerated by the speed reduction mechanism 20 including the spur gears 20a and 20b, but instead of this, for example, a planetary gear or a worm gear may be used.

  The manual valve 16 as a range switching means is disposed in the valve body 30 and is fitted so as to be movable in the axial direction (directions of arrows A and B). More specifically, the manual valve 16 can move to a P position corresponding to the P range, an R position corresponding to the R range, an N position corresponding to the N range, and a D position corresponding to the D range. When the manual valve 16 moves in the axial direction, the oil passage formed in the hydraulic circuit of the automatic transmission is switched, so that a predetermined required range selected by the shift lever 11 serving as the range selection means. Is set to be A hook portion 16a bent in an L shape is provided on the proximal end side of the manual valve 16, and the hook portion 16a is connected to a part of a detent lever 31 of a detent mechanism 25 described later, and the detent lever 31 is rotated. Thus, the manual valve 16 is moved in the axial direction.

  The position sensor 17 is housed in the casing 18, and one end of a manual shaft 24 is connected to the position sensor 17. The position sensor 17 is a range state detection unit that detects the position of the manual valve 16 that is a range switching unit, that is, a state of a shift range of the automatic transmission. For example, a potentiometer can be used as the position sensor 17, and a voltage corresponding to the rotation angle of the manual shaft 24 is output from the potentiometer. Therefore, the range position (P position, R position, N position, D position) can be detected as a zone having a predetermined width based on the voltage level output from the potentiometer. Further, a release bar 35 capable of manual range switching is provided with one end protruding from the casing 18.

  The detent mechanism 25 includes a detent lever 31, a detent spring 32 and an engagement roller 33. The detent lever 31 has a plate shape, and a rectangular engagement hole 37 is formed in the lower part. The other end of the manual shaft 24 is fitted in the engagement hole 37. Thereby, the detent lever 31 can be rotated in the directions of arrows C and D integrally with the manual shaft 24 with the manual shaft 24 as the rotation center. Further, an arm portion 38 is formed in the lower right portion of the detent lever 31, and an engagement hole 39 that is engaged with the proximal end side of the manual valve 16 is formed in the arm portion 38.

  As shown in FIG. 3, concave range grooves a, c, e, and g are provided in the upper portion of the detent lever 31 as four switching regions in order from the right in the drawing. Further, convex portions, that is, convex crest portions b, d, and f are formed between the range grooves a, c, e, and g. Range valley positions a1, c1, e1, and g1, which are the range valleys of the respective range grooves a, c, e, and g, correspond to the P position, R position, N position, and D position of the manual valve 16, respectively.

  As shown in FIG. 1, the detent spring 32 is formed of an elongated plate-like member, and its rear end is fixed to the valve body 30 of the hydraulic control device of the automatic transmission. Further, the tip of the detent spring 32 is divided into two forks, and the engagement roller 33 is rotatably supported between the forks. The detent spring 32 acts as a plate spring as a whole, and the urging force presses the engaging roller 33 against the range valley positions a1, c1, e1, and g1 of the detent lever 31 so that the detent lever 31 is positioned and held with high accuracy. It has become. FIG. 3 shows a state where the engagement roller 33 of the detent mechanism 25 is engaged with the rightmost range valley position a1, that is, a state where the automatic transmission is in the P range.

  When the shift signal S1 based on the selection operation of the shift lever 11 by the driver is input to the control unit 13, the control unit 13 is based on the shift signal S1. A motor control output signal C1 is output to the motor 14 to control the range switching device 10.

  Specifically, as shown in the control block diagram of FIG. 2, the control unit 13 receives a shift signal S1, and sets a target angle A0 according to the input shift signal S1, A position signal (voltage signal) P1 of the position sensor 17 is input, and a voltage-angle conversion unit 42 that converts the position signal P1 into a current angle A1 corresponding thereto, a target angle setting unit 41, and a voltage-angle conversion unit 42, respectively. A signal is input, a control unit 43 that calculates the angle difference between the target angle A0 and the current angle A1 to determine whether there is a shift request, and a voltage (current) signal corresponding to the angle difference signal from the control unit 43 is transmitted to the motor. The motor drive unit 44 outputs the control output signal C1.

  The range switching operation of the range switching device 10 will be described with reference to FIG. 3 taking an example of switching from the P range to the R range. In the P range, the engagement roller 33 of the detent mechanism 25 is engaged and held at the range valley position a1 in the range groove a. When the shift lever 11 is switched from the P range to the R range by the driver, a shift signal S1 corresponding to this is input to the control unit 13. The control unit 13 outputs to the motor 14 a control signal C1 corresponding to the deviation between the requested range position based on the shift signal S1 and the current range position detected by the position sensor 17.

  As a result, the motor 14 is driven in a predetermined drive direction, and the rotational motion of the output shaft of the motor 14 is decelerated by the speed reduction mechanism 20 and converted into the axial motion of the ball nut 27 by the ball screw mechanism 21. 23 is rotated integrally with the manual shaft 24 around the manual shaft 24 which is a drive shaft. With the rotation of the manual shaft 24, that is, the drive shaft, the detent lever 31 is rotated in the direction of arrow C in FIGS. 1 and 3, and the manual valve 16 is moved in the direction of arrow B.

  The control unit 13 stops the rotation of the motor 14 when the output voltage of the position sensor 17 reaches a value corresponding to the convex portion (peak portion) b in front of the R range position. When the rotation of the motor 14 is stopped, the detent lever 31 is rotated by the urging force of the engagement roller 33 based on the elastic force of the detent spring 32. In this way, the engagement roller 33 is engaged and held at the predetermined range valley position c1, and the manual valve 16 in the P position is switched to the R position. The same applies to other range switching operations.

  However, in such range switching, if there is an error in the output of the position sensor 17 that detects the angle of the manual shaft 24, braking of the motor 14 cannot be started from the original target angle, and reliable range switching is performed. There is a risk that it will not be possible.

  Therefore, according to the present invention, when the motor 14 is stopped, that is, in a state where the rotation of the manual shaft 24 is stopped, the engaging roller 33 is moved in the forward and reverse directions as will be described later, whereby the engaging roller 33 is moved to the detent lever 31. The range valley positions a1, c1, e1, and g1 can be reliably retracted.

  Hereinafter, a method for driving the motor 14 will be specifically described. As shown in FIG. 4, the motor 14 is driven in a state where the rotation of the manual shaft 24 is stopped, alternately in a predetermined extremely short time Ton in the P → D direction and the D → P direction every predetermined time Toff. Therefore, control is performed so as to give a predetermined amount of driving force To, -To. Here, the output on time (Ton) is the time when the output is continuously given, and then the motor 14 is turned off. After the engaging roller 33 is pulled into the range valley position of the detent lever 31, the detent lever 31 and the like The inertia is set to a very short time so as not to overshoot, and the output off time (Toff) is determined from the state where the detent lever 31 is stopped at an angle other than the range valley position. The time is set so that the rotation can be reliably generated.

  On the other hand, the driving forces To and -To applied to the motor 14 are driven when the detent lever 31 is positioned at the range valley position by the engaging roller 33 urged by the detent spring 32. However, the torque is such that the manual shaft 24 rotates slightly. In this case, when the motor 14 is driven and the manual shaft 24 rotates slightly, even if the manual shaft 24 is rotated by the torque generated by the motor 14, the engagement roller 33 biased by the detent spring 32 is detented. It means that it rotates to such an extent that it does not switch to a range valley different from the range valley formed on the lever 31 (to the extent that it does not exceed the convex portion, ie, the peak). The torque is set as follows so that the manual shaft 24 does not rotate even when the motor 14 is driven. That is, the torque generated from the urging force urged by the engagement roller 33 provided by the detent spring 32 at the range valley position causes the output shaft of the motor 14 to pass through the detent lever 31, the manual shaft 24 and the range switching device 10. The motor 14 is set to generate a torque smaller than or substantially equal to the transmitted torque.

  Accordingly, for example, as shown in FIG. 5, when the detent lever 31 is stopped at an angle other than the range valley position c1, and there is play G with respect to the P → D direction, the motor 14 is moved in the D → P direction. The detent lever 31 is not rotated even when driven, but when the motor 14 is driven in the P → D direction, the detent lever 31 is rotated in the arrow D direction by the amount of play G, whereby the engaging roller 33 is moved to the detent lever. The detent lever 31 is not rotated after the engagement roller 33 is drawn into the range valley position c1 of the detent lever 31.

  FIG. 6 is a flowchart for executing the processing of the shift-by-wire range switching device 10. When the ignition switch of the vehicle is turned on, power is supplied to the control unit 3 and the program shown in FIG. 6 is executed. In the program, first, in step S100, a subroutine for initialization processing when the ignition switch is ON (IG-ON) is executed. In step S200, the shift-by-wire (SBW) control processing subroutine is continued while the ignition switch is ON. When the ignition switch is turned off, a subroutine for processing at the time of ignition switch OFF (IG-OFF) in step S300 is executed.

  Next, each subroutine will be described. FIG. 7 shows an initialization process in the ECU on the vehicle side of the subroutine IG-ON initialization subroutine S100, and FIG. 8 shows an initialization process in the shift control unit (SCU) on the automatic transmission side. When the initialization process on the vehicle side shown in FIG. 7 is started, the accessory (ACC) is turned on in step S111, and power is supplied to the accessory. Next, in step S112, it is checked whether the ID of the vehicle key whose ignition switch is turned on matches the vehicle-side ID set in advance for the vehicle. If they match (YES), the process proceeds to step S113, and the ID flag is turned ON in step S113. If they do not match (N0), it is determined that the ignition switch has been turned on improperly, the process proceeds to step S114, and the ID flag is turned off in step S104. In step S115, an ID flag is transmitted to the shift control unit (SCU), and the initialization process on the vehicle side ends.

  On the other hand, when the initialization process on the SCU side shown in FIG. 8 is started, the ID flag transmitted from the vehicle side in step S115 described above is received in step S121, and then the ID flag is turned ON in step S122. It is determined whether or not. If the ID flag is ON (YES), the process proceeds to step S123 to receive the engine speed from the vehicle side, and then, in step S124, it is determined whether or not the received engine speed is greater than a predetermined value. Is done. If the engine speed is greater than the predetermined value (YES), the process proceeds to step S125, and the shift permission flag is turned on in step S125. Next, in step S126, a shift permission flag is transmitted to the control unit (TCU) of the automatic transmission, and in step S127, the shift-by-wire control flag is turned ON, and the initialization process on the SCU side ends.

  On the other hand, if the determination result in step S122 is NO (ID flag is OFF), or if the determination result in step S124 is NO (engine speed is less than a predetermined value), the engine is not running. In step S128, the shift permission flag is turned off. In step S129, the shift-by-wire control flag is turned off. In this case, the TCU may be notified that the shift-by-wire control is not executed. In this way, the initialization process on the SCU side is completed.

  A case where the shift permission flag is turned on in step S125 and normal SBW control is executed will be described based on a flowchart. FIG. 9 shows the shift request determination processing of the subroutine SBW control processing S200, and FIGS. 10 and 11 show the range switching command setting processing and the actual range position switching control processing. When the SBW control is executed, the shift request determination process shown in FIG. 9 is started. First, in step S211, it is determined whether or not there is a shift request, that is, whether or not the range has been switched by operating the shift lever 11. When the range is not switched (there is no shift request), the range signal S1 from the shift lever 11 and the actual range detected by the position sensor 17 are the same. It can be judged by comparing. If there is no shift request (YES), the process proceeds to step S212. In step S212, the range switching request flag is turned OFF. If there is a shift request (NO), the process proceeds to step S213, and in step S213, the range switching request flag is set. ON, and the shift request determination process ends.

  When the shift request determination process ends, the range switching command setting process shown in FIG. 10 is started. First, in step S221, it is checked whether or not the range switching request flag is ON. If it is ON (YES), the process proceeds to step S222. In step S222, the range signal S1 from the shift lever 11 is shifted to the shift command. When the range switching request flag is not ON (NO), the range switching command setting process is terminated without changing the shift command. The shift command here is a command to the motor 14 of the range switching device 10.

  When the range switching command setting process is completed, the actual range position switching control process shown in FIG. 11 is started. In step S231, it is determined whether or not the shift command set in step S222 is different from the actual range. When the shift command is equal to the actual range (NO), the range switching is not necessary, and after jumping to step S240 for performing the valley position drawing process described later, the actual range position switching control process is terminated.

  In step S231, when the shift command and the actual range are different (YES), the process proceeds to step S232, and it is checked whether or not the actual range is not being switched. Whether or not the actual range is being switched, that is, whether or not the manual valve has been switched to the range switching position corresponding to the shift range selected by the shift lever 11 is determined by the motor. Whether the control signal C1 is output from the control unit 13 to the motor 14 is determined.

  If the actual range is not being switched (YES), the process proceeds to step S233 to start the actual range switching. If the actual range is being switched (NO), the process proceeds to step S236. In step S233, the pull-in completion flag is turned OFF, and then in step S234, a brake point (BP) of the motor 14 is set based on the shift command. The brake point (BP) is a position (angle) corresponding to the shift command among the positions (angles) of the convex portions (peaks) b, d, and f of the detent lever 31. Subsequently, in step S235, the control signal C1 is output to the motor 14 in accordance with the shift command, and the motor 14 is driven.

  As a result, the rotational movement of the output shaft of the motor 14 is decelerated by the speed reduction mechanism 20 and converted into the axial movement of the ball nut 27 by the ball screw mechanism 21, and the manual shaft 24 and the detent lever 31 are passed through the arm 23. Is rotated in the direction of arrow C in FIGS. 1 and 3, and the manual valve 16 as the switching means is moved. The rotation angle of the manual shaft 24 is detected by the position sensor 17.

  In step S236, whether or not the sensor angle detected by the position sensor 17 matches the angle of a predetermined brake point (BP), that is, whether or not the motor 14 has reached the brake point (BP). Is judged. Specifically, it is determined whether or not the output voltage of the position sensor 8 has become a value corresponding to an angle corresponding to the shift command among the convex portions (peaks) b, d, and f of the detent lever 20. When the motor 14 reaches the brake point (BP) (YES), the process proceeds to step S237, where the drive of the motor 14 is stopped and the rotation of the manual shaft 24 is stopped in step S237. As a result, the manual shaft 24 is positioned at an angular position where the engagement roller 33 is engaged with a predetermined range valley position of the detent lever 31. Thereafter, the process proceeds to the above-described step S240 (valley position drawing process).

  In addition, after shifting to step S240 (valley position drawing process), the actual range position switching control process ends, but the actual range position switching control process is executed every short time to reach the brake point (BP). The driving of the motor 14 is continued until this time.

  As a result, the engaging roller 33 is engaged with the predetermined valley position of the detent lever 31 by the elastic force of the detent spring 32, and the manual valve 16 is switched to the required predetermined switching position. The range can be switched to the range corresponding to the shift command.

  FIG. 12 shows the valley position pull-in process. When the valley position pull-in process is started, a pull-in determination process shown in FIG. 13 described later is executed in step S250. In the subsequent step S241, the pull-in completion flag is OFF. In addition, it is checked whether or not the fail flag is OFF. If both the pull-in completion flag and the fail flag are OFF (YES), the process proceeds to step S260, and a pull-in execution process shown in FIG. 14 described later is executed in step S260. . However, if the determination result in step S241 is NO, that is, if at least one of the pull-in completion flag and the fail flag is ON, the pull-in execution process in step S260 is not performed, and the valley position pull-in process is terminated. Return to the shift-by-wire control program.

  When the pull-in determination process shown in FIG. 13 is started, it is checked in step S251 whether or not the pull-in completion flag is OFF. If not (NO), the process proceeds to step S252, and the pull-in completion flag is OFF. In the case (YES), it is determined that there is no need to perform the pull-in determination process, and the pull-in determination process is terminated. In step S252, it is determined whether or not a predetermined time (t1) has elapsed after completion of the shift. If the predetermined time has not elapsed (NO) after completion of the shift (NO), the sensor angle is determined in the next step S253. It is determined whether or not there is a deviation greater than or equal to a predetermined value from the range valley value to be performed. If there is no deviation greater than or equal to the predetermined value (NO), in a next step S254, a predetermined time (t2) or more from the previous pull-in determination is performed. It is determined whether or not a predetermined time has elapsed (NO). If the conditions for performing the pull-in determination process are not satisfied, the pull-in determination process is terminated.

  On the other hand, if any one of the determination results in steps S252 to S254 is YES, the process proceeds to step S255, the pull-in completion flag is turned off, and preparation for performing a pull-in execution process described later is made. In the state, the pull-in determination process ends.

  The pull-in determination means shown in FIG. 13 constitutes the pull-in determination means in the claims, and the pull-in determination means and the pull-in execution means described later constitute the valley position pull-in means in the claims. Yes.

  When the pull-in execution process shown in FIG. 14 is started, the motor operation counter is set to 0 in step S261. The motor operation counter counts the number of times the motor 14 has been rotated in the same direction. As will be described later, the motor operation counter determines that a failure has occurred if the count exceeds a predetermined count. Next, in step S262, the valley determination counter is set to zero. The valley determination counter counts the number of times that a state in which there is no change in the output (sensor angle) of the position sensor 17 when the motor 14 is driven for pull-in determination, and also switches the motor drive direction. It is what is used. Subsequently, in step S280, drive direction determination processing shown in FIG. 15 described later is executed, and the process proceeds to step S263.

  In step S263, the current sensor angle detected by the position sensor 17 (hereinafter referred to as the current angle) is defined as an angle before executing the above-described pull-in determination process (hereinafter referred to as an angle before execution of determination). Then, in step S264, based on the content of the drive direction flag set by the drive direction determination process in step S280, the motor 14 is rotated for a predetermined rotation direction, for example, P → D direction (or D → P) for Ton time. Direction). Next, in step S265, after the motor 14 waits for the Toff time, it is determined in step S266 whether or not the difference between the pre-determination angle and the current angle is equal to or less than a predetermined value. If it is equal to or smaller than the predetermined value (YES), the process proceeds to step S267. If it is equal to or larger than the predetermined value (NO), the process proceeds to step S270.

  In step S267, the valley determination counter is incremented, and then in step S268, it is determined whether or not the content of the valley determination counter has reached a set value, for example, 2 or more. ) Proceeds to step S269, reverses the drive direction flag, returns to the above step S263, executes step S263 and subsequent steps, and moves the motor 14 in the rotation direction opposite to the above, for example, the D → P direction (or P (→ D direction) It is controlled to drive for Ton time.

  In step S268, when the content of the valley determination counter becomes equal to or larger than the set value (2) and the determination result is YES, the process proceeds to step S274, the pull-in completion flag is turned on, and in step S275, the failure is determined. Turn off the flag. Next, in step S290, a valley position learning process shown in FIG. 16 described later is executed, and the pull-in execution process is ended.

  However, when the process proceeds to step S270 described above, the motor operation counter is incremented in step S270, and then in step S271, it is determined whether or not the content of the motor operation counter has reached a predetermined number of times. If the content exceeds the predetermined number of times (YES), the process proceeds to step S272. If the content is not the predetermined number of times (NO), the process returns to step S262 described above, and step S262 and subsequent steps are executed. In step S272, since it is predicted that some abnormality has occurred due to the content of the motor operation counter reaching the predetermined number of times, the fail flag is turned on to determine that a failure has occurred, and then in step S273, learning is performed in the past. The design value preset in each range is registered as a range valley learning value (hereinafter referred to as the range valley learning value), and the pull-in execution process is terminated.

  The pulling execution process shown in FIG. 14 constitutes the pulling execution means in the claims, and the pulling execution means and the pulling determination means constitute the valley position pulling means in the claims.

  The drive direction determination process 280 described above determines the drive direction of the motor 14, and can determine the drive direction of the motor 14 according to a range valley learning value learned as described later, for example. That is, as shown in FIG. 15, when the drive direction determination process is started, it is determined whether or not the current angle and the range valley learning value are equal in step S281. When the roller 33 is engaged and held at a predetermined valley position of the detent lever 31, it is determined that the valley position drawing process is unnecessary, and the valley position drawing process is terminated.

  However, when it is determined that the engagement roller 33 has an angle deviation (ΔA) of a predetermined angle or more from the predetermined valley position of the detent lever 31 and the current angle is not equal to the range valley learning value (NO). Next, in step S282, it is determined whether or not the current angle is on the P side with respect to the range valley learned value. If it is on the P side (YES), the process proceeds to step S283, and in step S283, the driving direction flag is determined. Is set in the P → D direction and is not on the P side, that is, when it is on the D side (NO), the process proceeds to step S284, and in step S284, the drive direction flag is set in the D → P direction, and the valley position is set. End the pull-in process.

  In this way, by setting the initial drive direction of the motor 14 according to the deviation direction of the current angle with respect to the range valley learning value, the engagement roller 33 is moved by the detent lever 31 by the first drive of the motor 14. The direction of engagement with the predetermined valley position can be controlled, and the number of times the motor 14 is driven for the valley position drawing process can be reduced. However, regardless of the current angle deviation direction with respect to the range valley learning value, the motor 14 may be first driven in the forward direction for the Ton time, and after the Toff time has elapsed, the motor 14 may be set to be driven in the reverse direction for the Ton time. it can.

  When the valley position learning process shown in FIG. 16 is started, it is determined in step S291 whether or not the current angle is within a predetermined range corresponding to the range. If the current angle is within the predetermined range (YES), Proceeding to step S292, the current angle is registered as the range valley learning value, and the valley position learning process is terminated. On the other hand, when the determination result in step S291 is NO (not within the predetermined range), the process proceeds to step S293 to set a predetermined design value as the range valley learning value, and the valley position learning process is performed. finish.

  FIG. 17 shows an end process in the ECU on the vehicle side of the subroutine S300 for IG-OFF processing, and FIG. 18 shows an end process in the shift control unit (SCU) on the automatic transmission side. When the termination process on the vehicle side shown in FIG. 17 is started, in step S311, it is checked whether or not the ignition switch is turned off. If it is turned off (YES), the process proceeds to step S312 and the ignition flag (IG Flag) is turned OFF, and then the content of the IG flag is transmitted to the shift control unit (SCU) in step S313, and the termination process on the vehicle side is terminated. On the other hand, if the determination result in step S311 is NO (not turned off), the process proceeds to step S314, the ignition flag (IG flag) is turned on, and then the process proceeds to step S313.

  On the other hand, when the termination processing on the SCU side shown in FIG. 18 is started, the contents of the IG flag transmitted in step S313 described above are received in step S321, and then in step S322, the IG flag is OFF and It is determined whether or not the actual range is the P range. If the IG flag is OFF and the actual range is the P range (YES), the process proceeds to step S323, and the SBW control flag is set to OFF. If the determination result in step S322 is NO (IG flag is OFF) If the actual range is not the P range, the process proceeds to step S323, a request signal for switching to the P range is transmitted to the vehicle side, and the termination process on the SCU side is terminated.

  Next, a specific example of valley position pull-in processing in the shift-by-wire range switching device 10 will be described based on the time chart of FIG. In the figure, the ON / OFF state of the pull-in completion flag, the position signal of the position sensor 17, and the driving torque of the motor 14 are also shown.

  In FIG. 19, it is assumed that the P range of the shift lever 11 is selected at time T0 and the vehicle is parked.

  At time T1, when the shift lever 11 is switched from, for example, the P range to the R range by the driver, a range signal S1 corresponding to the R range is input to the control unit 13, and the requested range (R range) and actual range (P range) ), That is, the difference between the target angle A0 set by the target angle setting unit 41 and the current angle A1 converted by the voltage-angle conversion unit 42, it is recognized that a shift request has been made. The motor 14 is driven to rotate.

  The rotational motion of the motor 14 is decelerated by the speed reduction mechanism 20 and converted into the axial motion of the ball nut 27 by the ball screw mechanism 21, and the manual shaft 24 and the detent lever 31 are moved via the arm 23, as shown in FIGS. 3 is rotated in the direction of arrow C. The rotation angle of the manual shaft 24 is detected by the position sensor 17, and based on the sensor signal from the position sensor 17, the manual shaft 24 is rotated to an angular position that reaches the set brake point BP (time T2). The motor 14 is stopped. Thereby, at time T3, the engagement roller 33 is engaged with the range valley position c1 corresponding to the R range of the detent lever 31, and the manual valve 16 as the range switching means is positioned at the R range position. In this manner, the actual range is switched from the P range to the R range, and the switching control to the actual range position is completed.

  When the predetermined time t1 has elapsed and the time T4 has elapsed after the end of the actual range position switching control, the valley position pull-in process starts, and the motor 14 rotates in the forward direction (or reverse direction) for an extremely short Ton time as shown in FIG. After the predetermined time Toff has elapsed, the motor 14 is driven in the reverse rotation direction (or the normal rotation direction) for a very short Ton time, and then the pull-in completion flag is turned on at time T5.

  By such pull-in processing by forward / reverse drive of the motor 14, the engagement roller 32 is accurately engaged and held at the range valley position c1 corresponding to the R range of the detent lever 31 in the actual range position switching control described above. Even if there is not, the engaging roller 33 can be reliably positioned at the range valley position c1 corresponding to the R range of the detent lever 31.

  That is, for example, due to an error in the output of the position sensor 17 that detects the angle of the manual shaft 24, the drive start position Ta of the motor 14 varies as shown in FIG. The brake point (BP) is not properly set, and the brake point (BP) is shifted from the original Ta1 to Ta2. For this reason, an angle deviation ΔA occurs in switching to the target actual range. However, when the motor 14 is stopped, the engagement roller 33 is moved to the detent lever by performing a trough position pull-in process by forward / reverse rotation of the motor 14. Even when the engagement roller 33 is not retracted to the predetermined range valley position c1 of 31, the engagement roller 33 can be reliably retracted to the range valley position c1 of the detent lever 31.

  That is, for example, in the actual range position switching control described above, the angular deviation ΔA occurs as shown by the solid line in FIG. 5 with respect to the range trough position c1 corresponding to the R range of the detent lever 31. Assuming that the switching control to the actual range position is finished in the state, the driving force of the motor 14 has a predetermined magnitude for each predetermined time Toff for a predetermined extremely short time Ton in the P → D direction or the D → P direction. When control is performed so that To and -To are alternately applied, when the motor 14 is driven in the P → D direction (forward rotation direction), the detent lever 31 is moved by the detent spring 32 due to the limitation of the driving force of the motor 14. Although it cannot be rotated against the elastic force of the engagement roller 33, when the motor 14 is driven in the D → P direction (reverse rotation direction), the engagement roller 33 and the detent The detent lever 31 is rotated in the D → P direction by the gap with respect to the range valley position c1 of the lever 31. As the detent lever 31 rotates, the engagement roller 33 is reliably positioned at the range valley position c1 of the detent lever 31. Be drawn into. After the engagement roller 33 is pulled into the range valley position c1 of the detent lever 31, the detent lever 31 is not further rotated due to the limitation of the driving force of the motor 14 described above.

  In this way, by executing the valley position pull-in process after the end of the actual range position switching control, the engagement roller 33 is reliably pulled into the range valley position c1 of the R range of the detent lever 31, and the next actual range is reached. In the position switching control, it is possible to reliably avoid a situation where the brake point (BP) is not properly set.

  The forward / reverse rotation of the motor 14 in the valley position pull-in process may theoretically be at least once. However, as shown in step S266 and the like, if it is performed until the fluctuation of the position sensor 17 is eliminated, a more reliable actual range. Can be switched.

  Further, as shown in step S282, if the direction of the current angle detected in advance by the position sensor 17 is determined to be the P side or the D side and the driving direction of the motor 14 is determined, the motor 14 is determined. It becomes possible to switch to the actual range by at least one forward or reverse rotation.

  In the time chart of FIG. 19 again, the sensor signal of the position sensor 17 deviates by a predetermined value or more (ΔA) despite the fact that the actual range position has not been changed due to, for example, temperature drift after the time T6 has elapsed. If it is confirmed (see step S253), the pull-in completion flag is turned off, and based on this, the pull-in execution process is executed again under the condition that the fail flag is turned off.

  In this case, since the range valley position of the detent lever 31 with respect to the engagement roller 33 is not shifted, the relative positional relationship between the engagement roller 33 and the detent lever 31 is not changed even if the pull-in execution process is performed. The sensor signal of the position sensor 17 is only updated as a new range valley position. When the update of the range valley position is completed (time T7), the pull-in completion flag is turned ON again.

  Furthermore, in the case where the same actual range, particularly the D range state continues for a long time, it is expected that the valley position of the detent lever 31 with respect to the engagement roller 33 is shifted due to vibration or the like. When the use is continued for a predetermined time t2 (several tens of minutes) (time T8), that is, when a predetermined time or more has elapsed since the previous execution of the pull-in determination (see step S254), the pull-in completion flag is turned off. A pull-in execution process similar to that described above is executed.

  As is apparent from the above description, according to the above-described embodiment, after a predetermined time has elapsed since the motor 14 was stopped, the motor 14 is rotated forward or reversely so that the engagement member (engagement roller) 33 is placed in the range valley. Since the trough position retracting means is provided, the drive shaft (manual shaft) 24 can be securely held at the position retracted into the range trough of the detent mechanism 25, and range switching in the shift-by-wire range switching device 10 can be performed. Reliability can be improved.

  According to the above-described embodiment, according to the second aspect of the invention, when the switching position when the motor is stopped and the switching position after the motor stop are different, the motor 14 is rotated at least in the normal direction or reversely and is engaged with the range valley. Since the valley position pulling means for pulling the combined member (engagement roller) 33 is provided, when the switching position different from the switching position from the range selecting means is detected when the motor 14 is stopped, the range is switched after the range switching due to vibration or the like. Even if a change from the valley occurs, the pulling into the range valley can be reliably performed, and the reliability of the range switching in the shift-by-wire range switching device 10 can be improved.

  According to the above-described embodiment, the valley position drawing means includes a drawing determination means that determines whether or not the engagement member (engagement roller) 33 is drawn in the range valley of the detent lever 31, and the drawing determination means. The drive shaft (manual shaft) 24 is detented because the motor 14 is rotated forward or backward based on the determination result and the engaging member (engaging roller) 33 is pulled into the range valley of the detent lever 31. Whether or not the mechanism 25 is drawn into the range valley can be accurately determined. When the mechanism 25 is not drawn into the range valley, the drawing into the range valley can be reliably performed.

  According to the above-described embodiment, the trough position retracting means is a retract determining means for determining whether or not the engaging member (engaging roller) 33 is retracted into the range trough of the detent lever 31 based on the switching position. The drive shaft (manual shaft) 24 is constituted by the pulling execution means for pulling the engaging member (engaging roller) 33 into the range valley by rotating the motor 14 forward or backward based on the determination result of the pulling determining means. Whether or not the detent mechanism 25 is drawn into the range valley can be accurately determined, and when the detent mechanism 25 is not drawn into the range valley, the drawing into the range valley can be reliably performed.

  According to the above-described embodiment, the switching position before and after the motor 14 is rotated forward or backward is compared, and it is determined whether or not the engaging member (engaging roller) 33 is pulled into the range valley. Therefore, it is possible to easily and surely determine whether or not it is drawn into the range valley by the change in the position signal of the position detecting means (position sensor) 17.

  According to the above-described embodiment, the motor 14 is rotated forward or backward by a driving force smaller than the torque received from the urging force of the engagement member (engagement roller) 33 for a predetermined time in the forward rotation direction and the reverse rotation direction. Thus, the detent lever 31 can be reliably operated only in the direction in which the engagement member (engagement roller) 33 engages the range valley.

  According to the above-described embodiment, the motor 14 is rotated forward or reverse until the switching position does not change, so that the engagement member (engagement roller) 33 is engaged with the range valley of the detent lever 31. It can be done reliably.

  According to the above-described embodiment, based on the shift range before and after being selected by the range selection, it is determined by the drive direction determination process that determines the drive direction of the motor 14 by setting the forward or reverse rotation of the motor 14. Since the motor 14 is driven in the motor driving direction different from the motor driving direction determined by the driving direction determination process after the motor 14 is rotated forward or reverse based on the motor driving direction thus set. Regardless of the switching position, it is possible to quickly pull into the range valley.

  According to the above-described embodiment, since the learning function for learning the switching position based on the switching position before and after the execution of the valley position retracting means is provided, the accuracy characteristic of the position detecting means (position sensor) 17 is obtained. Regardless of the change over time, the range can be accurately switched.

  FIG. 21 shows another embodiment of the valley position learning process. In step S301, the difference between the range valley learning value and the current sensor angle is calculated. Then, in step S302, the current (past) current value is used as a temporary learning value for each range valley (P range to D range). A value obtained by adding the above difference to the learning value is temporarily registered. Subsequently, in step S303, it is checked whether or not the P range provisional learning value is within a predetermined range. If it is within the predetermined range (YES), then in step S304, it is checked whether or not the provisional learning value of the R range is within the predetermined range. If it is within the predetermined range (YES), then in step S305, it is checked whether or not the temporary learning value of the N range is within the predetermined range. If it is within the predetermined range (YES), it is further checked in step S306 whether the provisional learning value of the D range is within the predetermined range. If it is within the predetermined range (YES), the process proceeds to step S307, the temporary learning value learned in step S302 is registered as a new learning value for each range valley, and the valley position learning process is terminated.

  However, if it is determined that the temporary learning value of each range is not within the predetermined range even in one of the above-described steps S303 to S306 (NO), the process proceeds to step S308, and learning of each range valley is performed in step S308. A preset design value is set as a value, and the valley position learning process is terminated.

  As described above, in another embodiment shown in FIG. 21, after a value obtained by adding the current learning value to the difference between the range valley learning value and the current sensor angle is temporarily registered as a temporary learning value in each range. The temporary learning values are registered as new learning values only when the temporary learning values are within a predetermined range in each range and only when they are within the predetermined range in all ranges. .

  FIG. 22 shows still another embodiment of the valley position learning process. In FIG. 22, in steps S311 and S312, the range valley learning value and the current value are displayed in the same manner as in the above embodiment shown in FIG. While calculating the difference with the sensor angle, a value obtained by adding the above difference to the current (past) learning value is temporarily registered as a temporary learning value for the valley in each range (P range to D range), and then step S313 (1), it is confirmed whether or not the provisional learning value of each range valley is within a predetermined range. In step S314, the learning value is updated with the provisional learning value only for the range within the predetermined range. In step S315, the range outside the predetermined range is updated with the design value corresponding to the range and step S314. The learning value is corrected based on the positional relationship with the learning value.

  According to another embodiment described above, when the difference between the switching position before and after the execution of the valley position drawing means is equal to or less than a predetermined value, the switching position before the execution of the valley position drawing means is set to the execution of the valley position drawing means. Since the update is performed based on the later switching position, erroneous learning can be prevented when the position detecting means (position sensor) 17 is out of order.

  Further, according to another embodiment described above, since only the switching position where the valley position drawing means is executed is updated, the valley of each range in the position detection means (position sensor) 17 is caused by temperature drift or the like. In the case of a sensor in which the relative relationship between positions changes, accurate range switching can be performed without affecting the sensor learning values at the valley positions of other ranges.

  In the above-described embodiment, after temporarily registering the value obtained by adding the current learning value to the difference between the range valley learning value and the current sensor angle as the temporary learning value in each range, the temporary learning value is stored in each range. The temporary learning value is registered as the learning value only in the range within the predetermined range, but the difference between the range valley learning value in one range and the current sensor angle is On the basis of the estimation that it also occurs in this range, the switching position where the valley position drawing means is not executed may be collectively updated based on the switching position where the valley position drawing means is executed. According to this, in the case of a sensor in which the relative relationship between valley positions of each range in the position detection means (position sensor) 17 does not change, accurate range switching is performed without performing valley position pull-in determination in other ranges. Can do.

  Note that the flowchart showing the pull-in determination process in FIG. 13 or the flowchart showing the pull-in execution process in FIG. 14 is merely an example of the present invention, and is not limited to this. Various embodiments can be adopted without departing from the scope.

  Further, in the above-described embodiment, the engagement roller 33 rotatably supported at the tip of the detent spring 32 is engaged with the range groove of the detent lever 31, but the engagement with the range groove is not necessarily related. For example, an engaging member made of a low friction material may be integrally provided at the tip of the detent spring 32.

  In the above-described embodiment, the driving direction of the motor 14 is determined according to whether or not the current angle is on the P side with respect to the range valley learning value, and the angle before the pull-in determination is performed and the current angle The example in which it is confirmed that the engagement roller 33 is reliably engaged with the range valley of the detent lever 31 by continuing the forward / reverse rotation operation of the motor 14 until the difference between and the predetermined value or less has been described. Regardless of whether or not the current angle is on the P side with respect to the range valley learning value, the detent lever can be simply driven once in the forward direction and in the reverse direction as shown in FIG. The engagement roller 33 can be engaged with 31 range valleys.

  Thus, the specific configuration described in the above embodiment is merely an example of the present invention, and the present invention is not limited to such a specific configuration. Of course, various embodiments can be employed without departing from the scope.

1 is a schematic diagram of a shift-by-wire range switching device showing an embodiment of the present invention. It is a figure which shows the control block of a shift-by-wire range switching apparatus. It is a figure which shows a detent lever. It is a figure which shows an example of the drive form of a motor. It is a figure which shows the engagement state of a detent lever and an engagement member (engagement roller). It is a flowchart which shows the program of a shift-by-wire type range switching apparatus. It is a flowchart which shows the initialization process by the side of the vehicle of the initialization process at the time of IG-ON in FIG. It is a flowchart which shows the initialization process by the side of the SCU of the initialization process at the time of IG-ON in FIG. It is a flowchart which shows the shift request determination process of the SBW control process in FIG. It is a flowchart which shows the range switching command setting process of the SBW control process in FIG. It is a flowchart which shows the real range position switching control process of the SBW control process in FIG. It is a flowchart which shows the valley position drawing-in process in FIG. 13 is a flowchart showing a pull-in determination process in FIG. It is a flowchart which shows the drawing execution process in FIG. It is a flowchart which shows the drive direction determination process in FIG. It is a flowchart which shows an example of the valley position learning process in FIG. It is a flowchart which shows the completion | finish process by the side of the vehicle of the process at the time of IG-OFF in FIG. It is a flowchart which shows the completion | finish process by the side of SCU of the process at the time of IG-OFF in FIG. It is a figure which shows the time chart of a shift-by-wire type range switching apparatus. It is explanatory drawing explaining the shift | offset | difference of a range valley position. It is a flowchart which shows another embodiment of the valley position learning process shown in FIG. It is a flowchart which shows another embodiment of the valley position learning process shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Range switching device, 11 ... Shift lever, 12 ... Vehicle speed sensor, 13 ... Control unit, 14 ... Motor, 15 ... Transmission mechanism (power transmission means), 16 ... -Range switching means (manual valve), 17 ... Position detecting means (position sensor), 20 ... Deceleration mechanism, 21 ... Ball screw mechanism, 24 ... Drive shaft (manual shaft), 25 ... Detent mechanism 31 ... Detent lever 32 ... Detent spring 33 ... Engagement member (engagement roller), a, c, e, g ... Range groove, b, d, f ..Protrusions (mountains), a1, c1, e1, g1... Range valley (range valley position).

Claims (7)

A motor is driven based on an electrical signal from a range selection means capable of selecting a plurality of shift ranges, and the rotation of the motor is transmitted to a drive shaft linked to the range switching means via a transmission mechanism, and the drive shaft In the range switching device that is positioned by the detent mechanism,
Having position detecting means for detecting a switching position of the range switching means;
The detent mechanism may have a engaging member that engages with the detent lever and the range valleys plurality of range valleys are formed corresponding to the shift range,
After the motor is driven and stopped based on the electrical signal from the range selection means, the engagement member is moved to the range valley of the detent lever based on the switching position after a predetermined time has elapsed since the motor stopped. Has a retraction determination means for determining whether or not
Based on the determination result of the pull-in determination means, the motor has a pull-in execution means for outputting a torque smaller than the torque generated from the urging force acting on the engagement member to cause the motor to rotate forward or reverse.
A shift-by-wire range switching device characterized by that. 2. The pull-in determination unit according to claim 1 , wherein the pull-in determination unit compares the switching position before and after the motor is rotated forward or reverse and determines whether or not the engaging member is pulled into the range valley. A shift-by-wire range switching device characterized by that. 3. The shift-by-wire range switching device according to claim 1 , wherein the pull-in execution unit rotates the motor forward or reverse until the switching position does not change. 4. The shift-by-wire system according to claim 1 , further comprising: a learning function that learns the switching position based on the switching position before and after the execution of the valley position drawing means. 5. Range switching device. 5. The learning function according to claim 4 , wherein when the difference between the switching position before and after execution of the valley position drawing means is equal to or smaller than a predetermined value, the switching position before execution of the valley position drawing means is determined as the valley position. A shift-by-wire range switching device, which is updated based on a switching position after execution of the pull-in means, and wherein the motor is driven based on the updated switching position. 6. The shift-by-wire range switching device according to claim 5 , wherein the learning function updates only the switching position executed by the valley position drawing means. 6. The shift-by-wire range according to claim 5 , wherein the learning function also updates the switching position not executed by the valley position drawing means based on the switching position executed by the valley position drawing means. Switching device.

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