JP5287788B2 - Automatic transmission range switching device - Google Patents

Description

  The present invention establishes one of a parking range (P range), a reverse range (R range), a neutral range (N range), and a drive range (D range) in an automatic transmission mounted on a vehicle such as an automobile. The present invention relates to a shift-by-wire range switching device.

  For example, in a configuration using a planetary gear mechanism or a friction engagement element (clutch, brake) or the like as a transmission mechanism portion of an automatic transmission, a hydraulic control circuit for engaging or releasing a clutch or brake necessary for establishing a required range The required range is established by supplying hydraulic pressure to the solenoid valve via a hydraulic path selectively formed by a manual valve of a hydraulic control circuit.

  The shift-by-wire range switching device includes a detent mechanism for positioning the manual valve spool and a parking rod of the parking mechanism in stages, an electric actuator for operating the detent mechanism, and the actuator And a control device (ECU: Electronic Control Unit).

  The control device recognizes a range requested by a driver's shift lever operation based on an output signal from a switch or a sensor and establishes the requested range by operating a detent mechanism by an actuator according to the recognition result. Let

  The actuator includes a motor and a deceleration mechanism that decelerates the output of the motor and transmits it to the output shaft. The detent mechanism includes a detent plate for pushing and pulling the spool and the parking rod by being rotated by a predetermined angle by the actuator, a detent spring for positioning and holding the attitude of the detent plate, and the like. A manual shaft connected to the output shaft of the motor is attached to the detent plate. The detent plate is provided with a corrugated portion including a plurality of valleys corresponding to the P, R, N, and D ranges and a mountain between the valleys, and a roller of the detent spring is engaged with any one of the valleys of the corrugated portion. Combined.

  Here, when the P range is selected by the shift lever, the detent plate is rotated by a predetermined angle, and in conjunction with the rotation of the detent plate, the parking rod of the parking mechanism is pushed to the back, and the automatic transmission Set the output shaft to the non-rotatable locked state.

  When the R range, N range, or D range is selected, the detent plate is rotated by a predetermined angle, and the parking rod is pulled forward in conjunction with the rotation of the detent plate, so that the output shaft of the automatic transmission is And the manual valve spool is displaced in the axial direction so that the frictional engagement elements such as the appropriate clutch and brake provided in the transmission mechanism of the automatic transmission are engaged or released. As a result, the requested range is established.

  The control device drives the motor by setting a target rotation angle (target count value of the encoder) of the motor output shaft corresponding to the required range selected by the shift lever, and the actual rotation angle of the motor is absolute It is detected by an encoder that is a relative position sensor that is not a position sensor, and the motor is feedback controlled so that the motor is stopped at a position where the detected actual rotation angle (actual count value) matches the target rotation angle.

  By the way, when switching to the P range or D range, if the detent plate is rotated and the roller is pressed against the P wall or D wall across the P range valley or D range valley of the detent plate, the detent spring Is excessively deformed, so that the durability of the detent spring is lowered as the number of range switching increases, which is not preferable. In order to suppress such a decrease in durability of the detent spring, it is desired to control the motor so that the detent spring is not excessively deformed.

  Therefore, a self-propelled start range that is widened by a predetermined angle (empirically set by experiment) from each bottom position of the P, R, N, and D range valleys on the detent plate is set, and the encoder count is set when the range is switched. When the value enters the self-running start range, it is determined that range switching is complete. The self-running start range is a range determination range at the time of range switching. When the requested range is established, the encoder count values at the bottom positions of the P, R, N, and D range valleys are stored as actual range data in a backup memory of the control device (for example, a memory that can retain the stored contents even after power is turned off). .

  In this case, it is necessary to set the position of the P wall or the position of the D wall in the detent plate as the reference position for the bottom positions of the P, R, N, and D range valleys and the left and right critical positions of the free-running start range. However, in consideration of the fact that the position of the P wall or the position of the D wall varies depending on the manufacturing tolerance of the detent plate or changes due to wear over time, the position of the P wall or the position of the D wall is more appropriate than storing the data as fixed data. It is preferable to detect and grasp at the timing.

  Therefore, a process for detecting both the actual P wall position and the D wall position, that is, a process for measuring the movable rotation range from the P wall position to the D wall position is performed, for example, at the time of factory shipment or a predetermined number of trips. I do it every time. Note that one trip is from when the power is turned on until it is turned off.

  The wall position detection process is performed in a state where the roller of the detent spring is engaged with the bottom of the P range valley or the D range valley of the detent plate. Then, the detent plate is rotated from this position to bring the P wall or D wall into contact with the roller, and when the state continues for a predetermined time, it is determined that the detent plate has stopped, and the encoder count value (motor output shaft Is detected as a P-side reference position or a D-side reference position in motor control. The P wall position and the D wall position detected by such a wall position detection process are stored in the buffer memory of the control device (memory in which the stored content disappears after the power is turned off), and are rewritten for each process.

  By the way, if there is a phenomenon in which the power supply to the control device is momentarily interrupted for some reason (instantaneous interruption), the data stored in the buffer memory (for example, the encoder count of the P wall position and the D wall position) Value etc.) will be lost. In addition, depending on the occurrence of the instantaneous interruption, stored data (for example, an actual range encoder count value) in the backup memory may be lost.

  Here, if a sensor that detects an absolute position is used instead of the encoder that is a relative position sensor as described above, when the control device is restarted after the instantaneous interruption, the P wall position, the D wall position, and the actual position are detected. Although it is possible to recognize the range, this absolute position sensor is expensive.

  For example, Patent Document 1 describes that in a shift-by-wire range switching device, an actual range can be grasped after a momentary interruption while using a relatively inexpensive relative position sensor.

  In Patent Document 1, for example, when the control device is restarted from an instantaneous interruption, the motor is not driven before the instantaneous interruption, and the output shaft position (encoder count relating to the actual range) stored in the backup memory with the instantaneous interruption. When the (value) is not destroyed (disappeared), the actual range is determined based on the output shaft position. When the control unit is restarted from a momentary interruption, the motor is not driven before the momentary interruption, and the output shaft position (encoder count value for the actual range) stored in the backup memory is destroyed due to the momentary interruption ( If it is lost, the actual range is determined based on the range request value output from the range setting means after returning from the instantaneous interruption.

Japanese Patent No. 4320648 (Japanese Patent Laid-Open No. 2006-336840)

  In the conventional example according to Patent Document 1, although it is possible to grasp the actual range after the control device is restarted from an instantaneous interruption, there is room for improvement in the following points.

  If the reference position (P wall position data and D wall position data) for determining the motor control amount by instantaneous interruption disappears, even if the control apparatus is restarted from the instantaneous interruption, the control apparatus Since it becomes impossible to grasp the position, when switching from the R range or N range to the P range or D range is requested, there is a high possibility that the range will not be switched correctly. There is a concern that there is a high possibility that motor control that avoids excessive deformation cannot be performed. For this reason, until the wall position detection process is performed on the next trip, the above-described excessive deformation of the detent spring is inevitably caused every time the range is switched, leading to a decrease in durability of the detent spring.

  However, when the actual range is the R range or N range, and there is no request to switch to the P range or D range, the wall position detection process is performed immediately. The possibility of malfunction will increase. That is, for example, when the actual range is the R range, if the P wall position detection process is performed, the P range may be obtained after the process is completed, and the D wall position detection process is performed. In this case, there is a risk that the D range is reached after the processing is completed.

  By the way, in the prior art document (Japanese Patent Laid-Open No. 2005-69406), in the shift-by-wire range switching device that switches between the parking range and the non-parking range, the power supply to the control device is interrupted. It is described that when the power supply is started again, the P wall position (reference position) where the rotation of the motor is stopped by the P wall is detected again. However, since this prior art document is different from a shift-by-wire range switching device that switches between four positions of the P range, R range, N range, and D range, the above-described problems do not occur. That is, this prior art document is presented as a reference example, not as a conventional example.

  In view of such circumstances, the present invention relates to a shift-by-wire range switching device for establishing any of the parking range, reverse range, neutral range and drive range of an automatic transmission. The purpose is to make it possible to take appropriate measures according to the estimation result of the actual range.

  A range switching device for an automatic transmission according to the present invention is for establishing any of a parking range, a reverse range, a neutral range, and a drive range by operating a manual valve or a parking mechanism of a hydraulic control circuit of the automatic transmission. A detent member, a motor for rotating the detent member, a detent spring for holding the detent member at the rotation stop position, an encoder for outputting a pulse signal corresponding to the rotation angle of the detent member, and the motor are controlled. And the detent member has a corrugated portion composed of valleys arranged in a line corresponding to the four ranges and peaks between the valleys, and the detent spring is engaged with any one of the valleys. And has an engaging portion that is pressed against the valley bottom. The control device, in addition to perform a range-switching process and the wall position detecting process described below, performs address that follows when a short break occurs.

  In the range switching process, a self-running start range (encoder target count value) of the roller in the valley of the detent member corresponding to the requested range in response to the range switching request is positioned at one end side in the rotation direction of the detent member. The actual count output from the encoder by driving the motor after setting the P wall outside the valley or the D wall outside the drive range valley located at the other end in the rotational direction of the detent member as a reference position. The required range is established by feedback-controlling the motor so that the motor is stopped when the value enters the self-running start range.

  The wall position detection process detects an encoder count value when the detent member stops rotating due to the P wall or D wall contacting the roller by rotating the detent member at a preset timing. The detected value is stored as data of the reference position in the first memory in which the stored contents disappear after the power is turned off.

  As a countermeasure against the instantaneous interruption, when the control device is restarted from an instantaneous interruption of the power supply, when it is estimated that the actual range is the reverse range or the neutral range, a request for switching to the parking range or the drive range is received. After that, the wall position detection process is performed.

  The present invention is premised on a range switching device that uses an encoder that is a relatively inexpensive relative position sensor without using an expensive sensor for detecting an absolute position.

  In such a range switching device, if there is a phenomenon in which the power supply to the control device is momentarily interrupted due to some factor (instantaneous interruption), the contents stored in the first memory (for example, in motor control) The P wall position data and the D wall position data, which are the reference positions, are lost.

  Therefore, in the present invention, when the control device is restarted from a momentary interruption, when it is estimated that the actual range is the R range or the N range, the range switching request is issued without immediately executing the wall position detection process. It is dealt with so that wall position detection processing is executed for the first time after receiving. In other words, the wall position detection process is performed with conditions.

  As a result, the actual range before the instantaneous interruption is kept as it is, and the actual range is changed to a different range by detecting the wall position even though the actual range is the R range or the N range as in the conventional example. It becomes possible to avoid the occurrence of malfunctions such as switching. In addition, while there is no range switching request, the actual range before the momentary interruption is held as it is, so that the driver does not feel uncomfortable.

  Preferably, the control device further includes a process of storing the actual count value output from the encoder as actual range data in a second memory capable of retaining stored contents even after the power is turned off when the required range is established. When the system is restarted from the instantaneous interruption, the actual range data is read from the second memory, and the actual range is estimated based on the actual range data.

  Here, since the actual range data is stored in the second memory, the possibility that the actual range data can be read from the second memory when the control device is restarted from a momentary interruption increases. The possibility that the actual range can be estimated increases.

  Incidentally, as the second memory, for example, a rewritable volatile memory such as an SRAM is used, and the stored contents are retained by supplying a backup current (dark current) after the power is turned off to the SRAM. be able to. In that case, when the instantaneous interruption occurs, the stored data may be lost depending on the occurrence situation.

  Preferably, when the control device is restarted after a momentary power interruption, when the real range is estimated to be a parking range or a drive range, the control device performs a wall position detection process corresponding to the real range. .

  With this configuration, it can be said that the wall position detection process can be performed immediately in an optimal situation, so that the motor control can be accurately performed when the next range switching is requested. As a result, the required range can be established accurately, and excessive deformation of the detent spring can be avoided, which is advantageous in improving durability.

  Preferably, when the control device is restarted from a momentary power interruption and determines that the actual range cannot be estimated, the control device performs a process of setting the automatic transmission to the neutral range, and then requests the next range switching. To wait.

  This configuration is advantageous in avoiding malfunctions such as switching to a range different from the actual range by inadvertently performing wall position detection processing even though the actual range cannot be estimated as in the conventional example. Become. Moreover, since the transmission of the driving force from the output shaft of the automatic transmission to the drive wheels is cut off by setting the automatic transmission to the neutral range, it is ensured that the vehicle moves in a direction that the driver does not expect. Can be prevented.

  When the control device is restarted from a momentary interruption, the automatic transmission range switching device according to the present invention is requested to switch to the parking lever or the drive range when the actual range is estimated to be the reverse range or the neutral range. After that, the wall position detection process is performed. This makes it possible to avoid malfunctions such as switching to a range different from the actual range as in the conventional example, and to maintain the actual range before the momentary interruption as long as there is no range switching request. Therefore, the driver does not have to feel uncomfortable.

It is a schematic block diagram of the range change apparatus of the automatic transmission which concerns on this invention. FIG. 2 is a skeleton diagram of the automatic transmission shown in FIG. 1. 3 is an operation table of the automatic transmission shown in FIG. 2. FIG. 3 is a schematic configuration diagram showing a part of a hydraulic control circuit of the automatic transmission shown in FIG. 2. It is a perspective view which shows schematic structure of the range switching apparatus of FIG. It is a perspective view which shows typically the shift gate of the shift lever of FIG. It is a front view which shows the detent plate of FIG. It is a figure which shows the mode in the P wall position detection process of the detent plate of FIG. It is a figure which shows the mode in the D wall position detection process of the detent plate of FIG. It is a flowchart which shows the example of control by the control apparatus of FIG.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

  1 to 10 show an embodiment of the present invention. In this embodiment, an FF (front engine / front drive) type power train is taken as an example. In the figure, 1 is an engine (internal combustion engine), 2 is a torque converter, 3 is an automatic transmission, 4 is a hydraulic control circuit for the automatic transmission 3, 5 is a shift-by-wire range switching device, and 80 is an ECU as a control device. (Electronic Control Unit). These configurations are described in detail below.

  A crankshaft (not shown), which is an output shaft of the engine 1, is connected to the torque converter 2, and the output of the engine 1 is transmitted from the torque converter 2 to the differential gear device 6 via the automatic transmission 3 or the like. And distributed to the left and right drive wheels 7,7.

-Engine-
The engine 1 is a multi-cylinder gasoline engine, for example. The amount of intake air taken into the engine 1 is adjusted by an electronically controlled throttle valve 11. The ECU 80 uses the throttle opening sensor 101 so as to obtain an optimal intake air amount (target intake air amount) corresponding to the operating state of the engine 1 such as the engine speed and the accelerator pedal depression amount (accelerator opening amount). The actual throttle opening of the throttle valve 11 is detected, and the throttle motor 12 of the throttle valve 11 is feedback-controlled so that the actual throttle opening coincides with the throttle opening (target throttle opening) at which the target intake air amount is obtained. To do. The throttle valve 11 can electronically control the throttle opening independently of the driver's accelerator pedal operation.

-Torque converter-
As shown in FIG. 2, the torque converter 2 includes a pump impeller 21, a turbine runner 22, a stator 23, a one-way clutch 24, a lock-up clutch 25, and the like, and hydraulic oil is provided between the pump impeller 21 and the turbine runner 22. Power transmission is performed via (ATF).

-Automatic transmission-
As shown in FIG. 2, the automatic transmission 3 includes a front planetary 33, a rear planetary 34, a plurality of clutches C1 and C2, a plurality of brakes B1 to B3, a one-way clutch F1, and the like. The gear stage can be selected.

  Since the automatic transmission 3 and the torque converter 2 are substantially symmetrical with respect to the center line, the lower half of the center line is omitted in FIG. Reference numeral 35 denotes a drive gear meshed with the driven gear 6 a of the differential gear device 6, and 36 denotes a case of the automatic transmission 3.

  The front planetary 33 is a single pinion type planetary gear mechanism, and includes a sun gear S1, a ring gear R1, a pinion gear P1, a carrier CA1, and the like.

  The rear planetary 34 is a Ravigneaux type planetary gear mechanism, and includes a small-diameter sun gear S2, a large-diameter sun gear S3, a ring gear R2, a plurality of short pinion gears PS, a plurality of long pinion gears PL, a carrier CA2, and the like. .

  Note that. The first clutch C1, the second clutch C2, the first brake B1, the second brake B2, and the third brake B3 are all friction engagement elements that are engaged or released by hydraulic pressure. By selecting the power transmission path of the front planetary 33 and the rear planetary 34 by engaging or releasing the clutches C1 and C2 and the brakes B1 to B3 in a predetermined state, an appropriate gear stage (first speed to 6th gear) is set.

  FIG. 3 is an engagement table for explaining the engagement operation of the clutches C1 and C2 and the brakes B1 to B3 for establishing each gear stage of the automatic transmission 3, wherein “◯” indicates engagement and “×”. Represents each release.

  The rotational speed (turbine rotational speed) of the input shaft 31 of the automatic transmission 3 is detected by the input shaft rotational speed sensor 102. Further, the rotational speed of the output shaft 32 of the automatic transmission 3 is detected by an output shaft rotational speed sensor 103. Based on the rotation speed ratio (output rotation speed / input rotation speed) obtained from the output signals of the input shaft rotation speed sensor 102 and the output shaft rotation speed sensor 103, the current gear stage of the automatic transmission 3 can be determined. it can.

-Hydraulic control circuit-
As shown in FIG. 4, the hydraulic control circuit 4 of the automatic transmission 3 includes an oil pump 401, a primary regulator valve 403, a secondary regulator valve 404, a modulator valve 405, a manual valve 410, a linear solenoid (SLT) 406, a linear solenoid ( SLU) 407, solenoid (SL) 408, linear solenoid (SL1) 411, linear solenoid (SL2) 412, linear solenoid (SL3) 413, linear solenoid (SL4) 414, B2 control valve 415, and the like.

  The oil pump 401 is driven by the rotation of the crankshaft of the engine 1 and sucks hydraulic oil (ATF) stored in the oil pan 402 to generate hydraulic pressure. The hydraulic pressure generated by the oil pump 401 is adjusted by the primary regulator valve 403 to generate the line pressure PL.

  The primary regulator valve 403 operates using the throttle pressure PSLT adjusted by the linear solenoid (SLT) 406 as a pilot pressure. The line pressure PL is supplied to the manual valve 410 through the first line pressure oil passage 421. The line pressure PL is adjusted by a linear solenoid (SL4) 414 and supplied to the hydraulic servo of the third brake B3.

  The secondary regulator valve 404 operates using the throttle pressure PSLT adjusted by the linear solenoid (SLT) 406 as a pilot pressure. The secondary regulator valve 404 adjusts the hydraulic pressure in the second line pressure oil passage 422 into which excess hydraulic oil that flows out (discharges) from the primary regulator valve 403 flows. Secondary pressure is generated by the secondary regulator valve 404.

  When the spool 410a of the manual valve 410 is in the D range position, the first line pressure oil passage 421 and the D range pressure oil passage 424 communicate with each other, and hydraulic pressure is supplied to the D range pressure oil passage 424. When the spool 410a of the manual valve 410 is in the R range position, the first line pressure oil passage 421 and the R range pressure oil passage 425 communicate with each other, and hydraulic pressure is supplied to the R range pressure oil passage 425. When the spool 410a of the manual valve 410 is in the N range position, the D range pressure oil passage 424 is shut off, the R range pressure oil passage 425 and the drain port 410b communicate with each other, and the R range pressure of the R range pressure oil passage 425 is increased. It is discharged from the drain port 410b.

  The hydraulic pressure supplied to the D range pressure oil passage 424 is finally supplied to the hydraulic servos of the first brake B1, the second brake B2, the first clutch C1, and the second clutch C2. The hydraulic pressure supplied to the R range pressure oil passage 425 is finally supplied to the hydraulic servo of the second brake B2.

  The modulator valve 405 adjusts the line pressure to a constant pressure. The hydraulic pressure (solenoid modulator pressure) PM adjusted by the modulator valve 405 is supplied to a linear solenoid (SLT) 406, a linear solenoid (SLU) 407, and a solenoid (SL) 408.

  The linear solenoid (SL1) 411 generates a first hydraulic pressure PC1 for controlling the engagement state of the first clutch C1 using the D range pressure PD output from the manual valve 410 as a base pressure, and the first hydraulic pressure PC1 is generated. Supply to the hydraulic servo of the first clutch C1.

  The linear solenoid (SL2) 412 generates a second hydraulic pressure PC2 for controlling the engagement state of the second clutch C2 using the D range pressure PD as a source pressure, and uses the second hydraulic pressure PC2 as a hydraulic servo for the second clutch C2. To supply.

  The linear solenoid (SL3) 413 generates a third hydraulic pressure PB1 for controlling the engagement state of the first brake B1 using the D range pressure PD as a source pressure, and uses the third hydraulic pressure PB1 as a hydraulic servo for the first brake B1. To supply.

  The linear solenoid (SL4) 414 generates a fourth hydraulic pressure PB3 for controlling the engagement state of the third brake B3 using the line pressure PL as a source pressure, and the fourth hydraulic pressure PB3 is used as a hydraulic servo for the third brake B3. Supply.

  The linear solenoid (SLT) 406 adjusts the solenoid modulator pressure PM in accordance with a control signal from the ECU 80 based on the throttle opening TAP detected by the throttle opening sensor 101, and generates the throttle pressure PSLT. The throttle pressure PSLT is supplied to the primary regulator valve 403 via the SLT oil passage 423. The throttle pressure PSLT is used as a pilot pressure for the primary regulator valve 403.

  The linear solenoid (SLT) 406, linear solenoid (SLU) 407, solenoid (SL) 408, linear solenoid (SL1) 411, linear solenoid (SL2) 412, linear solenoid (SL3) 413, linear solenoid (SL4) 414 are It is controlled by a control signal transmitted from the ECU 80.

  A D range pressure oil passage 424 and an R range pressure oil passage 425 are connected to the B2 control valve 415. The B2 control valve 415 selectively supplies hydraulic pressure from one of the D range pressure oil passage 424 and the R range pressure oil passage 425 to the second brake B2. The B2 control valve 415 is controlled by hydraulic pressures PSLU and PSL supplied from the linear solenoid (SLU) 407 and the solenoid (SL) 408 and the urging force of the spring 415a.

  When the solenoid (SL) 408 is OFF and the linear solenoid (SLU) 407 is ON, the B2 control valve 415 is in the state on the left side in FIG. In this case, the hydraulic servo of the second brake B2 is supplied with the hydraulic pressure adjusted from the D range pressure PD using the hydraulic pressure supplied from the linear solenoid (SLU) 407 as the pilot pressure. On the other hand, when the solenoid (SL) 408 is ON and the linear solenoid (SLU) 407 is OFF, the B2 control valve 415 is in the state on the right side in FIG. In this case, the R range pressure PR is supplied to the hydraulic servo of the second brake B2.

-Range switching device-
The range switching device 5 is a shift-by-wire system, and as shown in FIGS. 1 and 5, an operation input unit (a parking switch 61, a shift lever 62, etc.), a parking mechanism 51, a detent mechanism 52, an electric actuator 53, etc. It has.

  The operation of the range switching device 5 is controlled by the ECU 80. The ECU 80 recognizes the required range (P, R, N, D) by manually operating the parking switch 61 and the shift lever 62, operates the detent mechanism 52 by the actuator 53, and the parking mechanism 51 by the detent mechanism 52. Further, the required range is established by operating the manual valve 410 of the hydraulic control device 4.

  The parking switch 61 and the shift lever 62 are provided in a shift gate 60 installed near the driver's seat, for example, as shown in FIG. The parking switch 61 is a push switch or the like that alternately inputs a request signal for the P range and a request signal for canceling the P range to the ECU 80 every time a manual operation is performed by the driver. When the parking switch 61 selects the P range or the P range release, the ECU 80 displays this on a display unit (not shown) to notify the driver. As shown in FIG. 6, the shift lever 62 can be displaced from the home position (H) in the shift gate 60 to the N range position, R range position, D range position, and engine brake position (B). And automatically returns to the home position H after the operation.

  When the shift lever 62 is operated by the driver, the range position sensor 111 inputs an N range request signal, an R range request signal, a D range request signal, an engine brake request signal, and the like to the ECU 80. The ECU 80 displays the range selected by the shift lever 62 on a display unit (not shown) to notify the driver.

  The parking mechanism 51 switches between a parking state in which the output shaft 32 of the automatic transmission 1 is locked in a non-rotatable state or a parking release state in which the output shaft 32 is rotatably unlocked. As shown in FIG. A pole 512, a parking rod 513, and the like are provided.

  The detent mechanism 52 positions the parking rod 513 of the parking mechanism 51 and the spool 410a of the manual valve 410 by pushing and pulling in stages. As shown in FIG. 5, the detent mechanism 521, the manual shaft (support shaft) 522, detent spring 523, and the like.

  As shown in FIG. 5, the actuator 53 includes a motor 531 that serves as a drive source for the detent mechanism 52, a speed reduction mechanism 532, and the like.

  The motor 531 is a synchronous motor such as a switched reluctance motor (SR motor). The motor 531 is provided with an encoder 112 for detecting the rotation angle of the rotor. The encoder 112 is, for example, a magnetic rotary encoder, and outputs a pulse signal to the ECU 80 in synchronization with the rotation of the rotor of the motor 531.

  The rotation shaft of the detent plate 521 is fixed to the detent plate 521 so as to be integrally rotatable with the manual shaft 522 passing therethrough. The spool 410a of the manual valve 410 is connected to the detent plate 521, and a parking rod 513 is provided. It is fixed.

  One end of the manual shaft 522 in the axial direction is, for example, spline-coupled to the output shaft of the motor 531 or the rotation shaft of the speed reduction mechanism 532 so as to be coaxial and integrally rotatable. In addition, the other axial end of the manual shaft 522 is supported by the case 36 of the automatic transmission 3 so as to be rotatable, although not shown. Thus, when the detent plate 521 is rotated by the actuator 53, the spool 410a of the manual valve 410 and the parking rod 513 of the parking mechanism 51 are pushed and pulled.

  The outer shape of the detent plate 521 is formed in a fan shape, and corrugated portions (consisting of four valleys 521a to 521d and peaks between the valleys) are formed in a predetermined region thereof.

  The detent spring 523 is supported by the manual valve 410 in a cantilever state. The roller 524 rotatably attached to the free end side of the detent spring 523 is engaged with any one of the four valleys 521a to 521d of the detent plate 521, so that the detent plate 521 stops rotating. When this happens, the detent plate 521 is held almost stationary, and the spool 410a of the manual valve 410 is held almost stationary at the stop position (P range position, R range position, N range position, D range position). Yes.

  On the other hand, the parking lock pole 512 moves up and down around the support shaft 515 according to the position of the cam 514 mounted on the parking rod 513, and the vertical movement causes the lock pawl 512a of the parking lock pole 512 to move automatically. The rotation of the parking gear 511 is locked or unlocked by engaging with a parking gear 511 that is integrally formed with or fixed to the output shaft 32 of the No. 3 or by disengaging the lock claw 512a from the parking gear 511.

  The operation of such a range switching device 5 will be briefly described. First, when the P range is requested, the parking rod 513 is pushed in the direction approaching the parking lock pole 512, and the large-diameter portion of the cam 514 pushes up the parking lock pole 512 to lock the parking lock pole 512. 512a fits into the parking gear 511 and locks the parking gear 511 and the output shaft 32 of the automatic transmission 3 so that they cannot rotate. This state is a parking state.

  On the other hand, when a range other than the P range (R range, N range, D range) is requested, the parking rod 513 is pulled away from the parking lock pole 512, and the small diameter portion of the cam 514 contacts the parking lock pole 512. Since it comes into contact, the parking lock pole 512 is lowered. As a result, the lock pawl 512a of the parking lock pole 512 is disengaged from the parking gear 511, and the parking gear 511 and the output shaft 32 of the automatic transmission 3 are in an unlocked state. This state is a parking release state.

-ECU-
The ECU 80 has a known configuration including a central processing unit 81 and a storage device 82. When the ignition switch 110 is turned on, power is supplied and the ECU 80 is activated. The storage device 82 includes at least a program memory, a buffer memory 83, a backup memory 84, and the like (not shown).

  The buffer memory 83 is a memory in which data can be rewritten and the stored content disappears after the power is turned off, and is used for temporarily storing data. The buffer memory 83 is an NRAM, for example. The backup memory 84 is a memory that can rewrite data and can retain stored contents even after the power is turned off. As one of the backup memories 84, in this embodiment, for example, a known SRAM (memory whose stored contents are lost after the power is turned off) is used, and a backup current (dark current) is supplied to the SRAM after the power is turned off. Therefore, the stored contents are used in the form of holding.

  As shown in FIG. 1, an input interface (not shown) of the ECU 80 includes a throttle opening sensor 101, an input shaft speed sensor 102 of the automatic transmission 3, an output shaft speed sensor 103 of the automatic transmission 3, an accelerator opening. A degree sensor 104, a brake pedal sensor 105, an ignition switch 110 for turning on / off the power, a parking switch 61, a range position sensor 111, an encoder 112, and the like are connected.

  Connected to the output interface (not shown) of the ECU 80 are a throttle motor 12 of the engine 1, a hydraulic control circuit 4, a driver of the motor 531 (not shown), an injector (not shown), an ignition plug igniter, and a display device. Has been. The objects connected to the input interface and the output interface here are only those directly related to the present invention.

  When the ECU 80 recognizes the required range based on the signal selected by the shift lever 62 and input from the range position sensor 111, the ECU 80 executes a range switching process.

  In this range switching process, the target rotation angle (target count value of the encoder 112) of the output shaft of the motor 531 is set in accordance with the requested range, and then the motor 531 is driven, and the actual rotation angle of the motor 531 is converted into the encoder. The motor 531 is feedback-controlled so that the motor 531 is stopped at a position where the detected actual rotation angle (actual count value) coincides with the target rotation angle. When the required range is established in this way, the actual rotation angle (actual count value) is stored in the backup memory 84 as actual range data, but is rewritten each time the processing is executed.

  The ECU 80 controls an appropriate linear solenoid or the like of the hydraulic control circuit 4 so as to establish a transmission gear stage (6 forward speeds and 1 reverse speed) suitable for the driving situation when traveling in the D range. Thus, the first and second clutches C1 and C2 and the first to third brakes B1 to B3 of the automatic transmission 3 are engaged or released.

  By the way, when switching to the P range or the D range, the detent plate 521 is rotated so that the roller 524 is pressed against the P wall 521P or the D wall 521D beyond the P range valley 521a or the D range valley 521d of the detent plate 521. If so, the detent spring 523 is excessively deformed, so that the durability of the detent spring 523 decreases as the number of range switching increases, which is not preferable.

  Therefore, in this embodiment, the motor 531 is controlled so as not to excessively deform the detent spring 523 in order to suppress a decrease in the durability of the detent spring 523. Therefore, the control method of the motor 531 is described with reference to FIG. explain.

  First, the angle from the position of the P wall 521P located outside the P range valley 521a in the detent plate 521 to the position of the D wall 521D located outside the D range valley 521d is the movable rotation range of the motor 531. It becomes.

  Then, in each of the P, R, N, and D range troughs 521a to 521d, self-running start ranges (or sliding-in ranges) XP, XR, XN, and XD that serve as a guide for the roller 524 to reliably engage are set. Control is performed to stop the rotation of the motor 531 when the roller 524 enters the self-running start range XP, XR, XN, XD after rotating the detent plate 521 by rotating the 531. That is, the target rotation angle for establishing the required range is set to the self-running start range XP, XR, XN, XD of the roller 524 in the valley of the detent plate 521 corresponding to the required range.

  This free-running starting range XP, XR, XN, XD is a predetermined angle (empirically by experiment) from the respective bottom positions θP, θR, θN, θD of the P, R, N, D range valleys 521a to 521d in the rotational direction. It is set by setting).

  The left and right critical positions of the bottom positions θP, θR, θN, θD and the free-running start ranges XP, XR, XN, XD (see the two-dot chain line in FIG. 7) are the positions of the P wall 521P in the detent plate 521 or the D wall 521D. Is set as a reference position. Therefore, by associating the position of the P wall 521P and the position of the D wall 521D with the count value of the encoder 112 (the rotation angle of the detent plate 521 or the rotation angle of the output shaft of the motor 531), each bottom position θP, θR, θN , ΘD and the right and left critical positions of the free-running start ranges XP, XR, XN, and XD can be recognized by the ECU 80. Therefore, the motor 531 can be stopped when the actual count value output from the encoder 112 when the motor 531 is driven enters the free-running start range XP, XR, XN, XD. Accordingly, the free-running start ranges XP, XR, XN, and XD are the range determination ranges.

  By the way, regarding the position of the P wall 521P and the position of the D wall 521D, considering that there is a solid difference due to manufacturing tolerances of the detent plate 521 and changes due to wear over time, the data is stored in the memory as fixed data. However, it is preferable to detect and grasp at an appropriate timing.

  The process for detecting both the actual P wall position and the D wall position, that is, the process for measuring the movable rotation range from the P wall position to the D wall position is performed, for example, at the time of factory shipment or every predetermined number of trips. Like to do. Note that one trip is from when the power is turned on by the ignition key 110 until it is turned off.

  This wall position detection process basically includes a state where the roller 524 of the detent spring 523 is engaged with the bottom θP of the P range trough 521a of the detent plate 521 or the bottom θD of the D range trough 521d (P range or D range). ).

  In the P wall position detection process, for example, the detent plate 521 is rotated in the clockwise direction in FIG. 7 from the position where the roller 524 is engaged with the bottom θP of the P range valley 521a of the detent plate 521 (see the one-dot chain line in FIG. 8). Then, the P wall 521P is brought into contact with the roller 524 (see the solid line in FIG. 8), and when the state continues for a predetermined time, it is determined that the detent plate 521 has stopped, and the count value of the encoder 112 (the output of the motor 531) The rotation angle of the shaft is detected as the P-side reference position for motor control.

  Further, in the D wall position detection process, for example, the detent plate 521 is rotated counterclockwise in FIG. 7 from the position where the roller 524 is engaged with the bottom θD of the D range trough 521d of the detent plate 521 (see the dashed line in FIG. 9). And the D wall 521D is brought into contact with the roller 524 (see the solid line in FIG. 9), and the detent plate 521 is stopped when the state continues for a predetermined time. The rotation angle of the shaft is detected as the D-side reference position for motor control.

  The detected value of the P wall position and the detected value of the D wall position (the count value of the encoder 112) detected by these processes are stored in the buffer memory 83 of the ECU 80, but are rewritten every time the process is executed.

  When the motor 531 is stopped to finish the P wall position detection process or the D wall position detection process, the roller 524 is moved from the P wall 521P or D wall 521D to the P range valley 521a or D by the elastic force of the detent spring 523. It slips into the bottoms θP and θD of the range valley 521d (self-running phenomenon).

  Incidentally, if a phenomenon (instant interruption) in which the power supply to the ECU 80 is momentarily interrupted for some reason occurs, the stored data in the buffer memory 83 (for example, the encoder count of the P wall position and the D wall position). Value etc.) will be lost. Further, depending on the occurrence state of the instantaneous interruption, the stored data (for example, an actual range encoder count value) in the backup memory 84 may be lost. This embodiment deals with such an instantaneous interruption as follows, and will be described in detail.

-Control of ECU80-
Next, an example of control executed by the ECU 80 will be described with reference to FIG. The flowchart shown in FIG. 10 is started every predetermined time (several milliseconds) after the power is turned on by the ignition switch 110.

  First, in step S1, the real range data (actual count value of the encoder 112) stored in the backup memory 84 is read, and the P wall position data and D wall position data (wall position detection) stored in the buffer memory 83 are read. The actual count value of the encoder 112 detected by the processing) is read out.

  Thereafter, in step S2, it is checked whether or not the power supply is momentarily interrupted. For example, when there is a momentary interruption, at least the contents stored in the buffer memory 83 are lost. That is, in this step S2, it is possible to determine whether or not the instantaneous interruption has occurred by checking whether or not the P wall position data and the D wall position data have been read from the buffer memory 83 in step S1. .

  Therefore, if an affirmative determination is made in step S2, that is, if the stored contents of the buffer memory 83 have disappeared, it is determined that an instantaneous interruption has occurred, and the process proceeds to the subsequent step S3. In step S3, the actual range is estimated based on the actual range data read from the backup memory 84.

  On the other hand, if a negative determination is made in step S2, that is, if the stored contents of the buffer memory 83 are not lost, it is determined that no instantaneous interruption has occurred, and the process skips step S3 and proceeds to step S4. .

  In step S4, it is checked whether or not the wall position detection process has not been performed. When the P wall position detection process and the D wall position detection process are executed, the P wall position detection flag and the D wall position detection flag are set to “1”. Whether or not the position detection process is performed can be determined.

  If a negative determination is made in step S4, that is, if a wall position detection process is being performed, this flowchart ends. However, if an affirmative determination is made in step S4, that is, if the wall position detection process is not performed, the flow proceeds to the following steps S5 to S10.

  First, in step S5, it is determined whether or not the actual range estimated in step S3 is the P range or the D range.

  If an affirmative determination is made in step S5, that is, if it is determined that the range is the P range or the D range, the wall position detection process is executed in step S6, and then this flowchart ends. If it is determined in step S5 that it is in the P range, P wall position detection processing is performed in step S6. If it is estimated in step S5 that it is in the D range, it is determined in step S6. D wall position detection processing is performed.

  On the other hand, if a negative determination is made in step S5, that is, if it is determined that the range is not the P range or the D range, it is determined in step S7 whether the range is the R range or the N range.

  If an affirmative determination is made in step S7, that is, if it is determined that the range is the R range or the N range, it is determined in step S8 whether there is a request for switching to the P range or the D range.

  If a negative determination is made in step S8, that is, if there is no switching request, this flowchart is terminated. On the other hand, if an affirmative determination is made in step S8, that is, if there is a switching request, in step S9, the range switching process requested for switching is performed, and this flowchart ends. In this range switching process, when the required range is the P range, the P wall position detection process is performed, and then the motor 531 is driven so that the P range is continuously established. On the other hand, if the required range is the D range, the D wall position detection process is performed, and then the motor 531 is driven so that the D range is continuously established.

  By the way, if a negative determination is made in step S7, that is, if it is determined that the current range is not the R range or the N range, this corresponds to a situation where the actual range cannot be estimated. By setting the range, the transmission of the driving force from the output shaft 32 of the automatic transmission 3 to the driving wheel 7 is cut off, and then the process proceeds to step S8.

  As described above, in the embodiment to which the features of the present invention are applied, the following effects can be obtained.

  (1) When the ECU 80 is restarted from an instantaneous interruption, when it is estimated that the actual range is the R range or the N range (Yes determination in step S7), the P wall position detection process or the D wall position detection process is immediately performed. The P wall position detection process or the D wall position detection process is executed only after receiving a range switching request without executing the above. In other words, P wall position detection processing or D wall position detection processing is performed under certain conditions.

  In this case, it can be said that the actual range before the momentary interruption is held as it is, and it is waited until the situation becomes appropriate for performing the P wall position detection process or the D wall position detection process. As a result, malfunctions such as switching to the P range or the D range by performing the P wall position detection process or the D wall position detection process even though the actual range is the R range or the N range as in the conventional example. Occurrence can be avoided. In addition, while there is no range switching request, the actual range before the momentary interruption is held as it is, so that the driver does not feel uncomfortable.

  (2) When the ECU 80 is restarted from an instantaneous interruption, if it is estimated that the actual range is the P range or the D range (positive determination in step S5), the P wall position detection process or the D wall position detection process is performed. I am doing so.

  In this case, it is possible to quickly detect the wall position corresponding to the actual range while maintaining the actual range before the instantaneous interruption, and to detect the wall position serving as the reference position for motor control. This means that the P wall position detection process or the D wall position detection process can be performed immediately in an optimal situation, so that the motor control is performed accurately when the next range change is requested. Is possible. Therefore, the required range can be established accurately, and excessive deformation of the detent spring 523 can be avoided, which is advantageous in improving durability.

  (3) When the actual range cannot be estimated when the ECU 80 restarts from a momentary interruption (both negative determinations in steps S5 and S7), the automatic transmission is not performed without performing the P wall position detection process and the D wall position detection process. 3 is set to the N range (step S10).

  In this case, malfunctions such as switching to a range different from the actual range by performing P wall position detection processing or D wall position detection processing carelessly even though the actual range cannot be estimated as in the conventional example. This is advantageous in avoiding the occurrence. Moreover, since the transmission of the driving force from the output shaft 32 of the automatic transmission 3 to the drive wheels 7 is cut off by setting the automatic transmission 3 to the N range, the vehicle moves in a direction unexpected by the driver. Can be surely prevented.

  In addition, this invention is not limited only to the said embodiment, All the deformation | transformation and application included in the range equivalent to the claim and the said range are possible. Examples are given below.

  (1) In the above embodiment, an FF (front engine / front drive) type power train is taken as an example. However, the present invention is not limited to this, and for example, FR (front engine / rear drive). It can also be applied to a power train of a type and a four-wheel drive type.

  (2) In the above embodiment, the planetary gear type automatic transmission 3 is taken as an example. However, the present invention is not limited to this, and for example, a belt-type continuously variable gear that continuously adjusts the gear ratio. It can also be applied to a transmission (CVT: Continuously Variable Transmission).

  (3) In the above embodiment, when the ECU for monitoring the range switching device 5 is provided, the same data as the actual range data stored in the backup memory 84 of the ECU 80 is also stored in the backup memory of the monitoring ECU. When the ECU 80 performs processing for estimating the actual range after the instantaneous interruption has occurred, the actual range data may be transmitted from the backup memory of the monitoring ECU. Is possible. In this case, there is a high possibility that the actual range can be estimated.

1 engine
2 Torque converter
3 Automatic transmission
4 Hydraulic control circuit 410 Manual valve 410a Manual valve spool
5 Range Changeover Device 51 Parking Mechanism 52 Detent Mechanism 521 Detent Plate 521a P Range Valley 521b R Range Valley 521c N Range Valley 521d D Range Valley 521P P Wall 521D D Wall 522 Manual Shaft 523 Detent Spring 524 Roller 53 Actuator 531 Motor 61 Parking Switch 62 Shift lever 80 ECU
83 Buffer memory 84 Backup memory 110 Ignition switch 111 Range position sensor 112 Encoder

Claims (4)

A detent member for establishing one of a parking range, a reverse range, a neutral range and a drive range by operating a manual valve or a parking mechanism of a hydraulic control circuit of an automatic transmission, and a motor for rotating the detent member A detent spring for holding the detent member at the rotation stop position, an encoder for outputting a pulse signal corresponding to the rotation angle of the detent member, and a control device for controlling the motor,
The detent member has a corrugated portion composed of valleys arranged in a line corresponding to the four ranges and a mountain between the valleys, and the detent spring has an engaging portion engaged with any one of the valleys. And having the engagement portion pressed against the valley bottom,
In response to the range switching request, the control device sets the free-running start range (the target count value of the encoder) of the roller in the valley of the detent member corresponding to the requested range to the parking range valley located on one end side in the rotation direction of the detent member. The actual count value output from the encoder by driving the motor after setting the outer P wall or the D wall outside the drive range valley located on the other end side in the rotational direction of the detent member as a reference position A range switching process that establishes a required range by feedback controlling the motor to stop the motor when entering the self-running start range;
By rotating the detent member at a preset timing, the encoder count value is detected when the detent member stops rotating due to the P wall or D wall coming into contact with the roller. In addition to executing wall position detection processing for storing the detected value as data of the reference position in the disappearing first memory,
The control device detects the wall position after receiving a request for switching to a parking range or a drive range when it is estimated that the actual range is a reverse range or a neutral range when restarted from a momentary power interruption. A range switching device for an automatic transmission, characterized in that processing is performed. In the automatic transmission range switching device according to claim 1,
The control device further performs a process of storing the actual count value output from the encoder as actual range data in the second memory that can retain the stored contents even after the power is turned off when the required range is established,
A range switching device for an automatic transmission, which, when restarted from the momentary interruption, reads actual range data from the second memory and estimates the actual range based on the actual range data. In the automatic transmission range switching device according to claim 1 or 2,
When the control device is restarted after a momentary power interruption, and the actual range is estimated to be a parking range or a drive range, the control device is adapted to perform wall position detection processing corresponding to the actual range. The automatic transmission range switching device. In the range change device of the automatic transmission according to any one of claims 1 to 3,
When the control device is restarted from a momentary power interruption and determines that the actual range cannot be estimated, the control device performs processing for setting the automatic transmission to the neutral range and then waits for the next range switching request. A range switching device for an automatic transmission, characterized by coping with it.

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