JP2022147857A - shift control device - Google Patents

Abstract

To provide a shift control device which can suppress the wear of a parking gear and a parking wheel caused by ratchetting at which a claw of a parking pole is repeatedly flipped by teeth of the parking gear.SOLUTION: An SBW-CU 80 determines whether or not there occurs ratchetting at which a claw of a parking pole 113 is repeatedly flipped by teeth of a parking gear 114 when switching a shift range of a continuously variable transmission 30 to a parking range, and when it is determined that the ratchetting occurs, switches the shift range of the continuously variable transmission 30 to a neutral range. When an average value of a secondary-shaft rotation number per unit time in a prescribed time of a rotation variation is equal to or larger than a prescribed threshold, the SBW-CU 80 determines that the ratchetting occurs.SELECTED DRAWING: Figure 1

Description

The present invention relates to a shift control device for an automatic transmission.

Conventionally, an automatic transmission mounted on a vehicle has a parking gear and a parking pole provided on an output shaft, and when the parking (P) position is selected, the parking pole is engaged with the parking gear. A parking mechanism is used that locks the rotation of the automatic transmission and puts the automatic transmission in a parking state (parking range) (see, for example, Patent Document 1).

In such a parking mechanism, when the select lever is operated to the parking (P) position while the vehicle is running, the claws of the parking pole are repeatedly flipped by the teeth of the parking gear when the vehicle speed is higher than the engagement speed of the parking gear. , a so-called ratcheting state is established, and the parking gear and the parking pole are prevented from meshing.

JP-A-9-152031

However, if the ratcheting state is repeated, the parking gear, the parking pole, and the like will be worn, which will be a factor in deteriorating the durability of the parking mechanism. In addition, contamination occurs due to wear of parking gears, parking poles, and the like, which may, for example, accelerate wear of other members and cause valve sticking. It should be noted that when the vehicle speed is higher than a predetermined set value, even if the parking (P) position is selected, it does not switch to the parking range. Transmissions are also known, but even such automatic transmissions can experience ratcheting if the parking inhibit function fails.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The object is to provide a control device.

A shift control device according to an aspect of the present invention includes a selection means for receiving an operation for selecting a shift range of an automatic transmission and outputting selection information according to the operation; a control unit for switching the shift range of the automatic transmission; a parking gear; and a parking pole. The control unit determines whether ratcheting, in which the pawl of the parking pole is repeatedly flipped by the teeth of the parking gear, occurs when the shift range of the automatic transmission is switched to the parking range. and switching the shift range of the automatic transmission to the neutral range when it is determined that ratcheting has occurred.

According to the present invention, it is possible to suppress wear of the parking gear and the parking pole due to ratcheting in which the pawl of the parking pole is repeatedly repelled by the teeth of the parking gear.

1 is a block diagram showing a configuration of a shift control device according to an embodiment, and a powertrain and drive force transmission system of an AWD vehicle equipped with the shift control device; FIG. It is a figure which shows the structure of the parking mechanism of a continuously variable transmission. 4 is a flow chart showing a processing procedure of shift range (parking range) switching processing by the shift control device according to the embodiment; FIG. 11 is a flow chart showing a processing procedure of shift range (parking range) switching processing by a shift control device according to a modification; FIG.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Further, in each figure, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

First, the configuration of the shift control device 1 according to the embodiment will be described with reference to FIGS. 1 and 2 together. FIG. 1 is a block diagram showing the configuration of a shift control device 1, and a power train and driving force transmission system of an AWD (All Wheel Drive) vehicle equipped with the shift control device 1. As shown in FIG. FIG. 2 is a diagram showing the construction of the parking mechanism 110 of the continuously variable transmission (CVT) 30. As shown in FIG. In this embodiment, an FF (front engine front drive) based part-time AWD vehicle equipped with a shift-by-wire (SBW) continuously variable transmission 30 will be described as an example.

The engine 20 may be of any type, but is, for example, a horizontally opposed direct injection four-cylinder gasoline engine. In the engine 20, air taken in from an air cleaner (not shown) is throttled by an electronically controlled throttle valve (hereinafter simply referred to as "throttle valve") provided in the intake pipe, passes through the intake manifold, and enters the engine 20. It is sucked into each formed cylinder. Here, the air flow meter 71 detects the amount of air sucked from the air cleaner. Further, the throttle valve is provided with a throttle opening sensor 72 for detecting the opening of the throttle valve. Each cylinder is equipped with an injector that injects fuel. Each cylinder is equipped with an ignition plug that ignites the air-fuel mixture, and an igniter built-in coil that applies a high voltage to the ignition plug. In each cylinder of the engine 20, a mixture of intake air and fuel injected by an injector is ignited by a spark plug and combusted. Exhaust gas after combustion is discharged through an exhaust pipe.

In addition to the airflow meter 71 and the throttle opening sensor 72 described above, a cam angle sensor for discriminating the cylinders of the engine 20 is attached near the camshaft of the engine 20 . A crank angle sensor 75 for detecting the position of the crankshaft is attached near the crankshaft of the engine 20 . These sensors are connected to an engine control unit (hereinafter referred to as "ECU") 70, which will be described later. Also connected to the ECU 70 are various sensors such as an accelerator pedal sensor 73 that detects the amount of depression of the accelerator pedal, that is, the degree of opening of the accelerator pedal, and a water temperature sensor 74 that detects the temperature of the cooling water of the engine 20 .

A continuously variable transmission 30 ( (corresponding to the automatic transmission described in the claims) is connected.

The torque converter 22 mainly consists of a pump impeller 23 , a turbine liner 24 and a stator 25 . A pump impeller 23 connected to the crank 21 generates a flow of oil, and a turbine liner 24 arranged opposite the pump impeller 23 receives the power of the engine 20 via oil to drive the turbine shaft 31 . A stator 25 positioned between the two rectifies the exhaust flow (return) from the turbine liner 24 and returns it to the pump impeller 23 to generate a torque amplification effect.

The torque converter 22 also has a lockup clutch 26 that directly connects the input and the output. When the lockup clutch 26 is not engaged (in a non-lockup state), the torque converter 22 amplifies the driving force of the engine 20 and transmits it to the continuously variable transmission 30 so that the lockup clutch 26 is engaged. When it is on (during lockup), the driving force of the engine 20 is directly transmitted to the continuously variable transmission 30 . The rotation speed (turbine rotation speed) of the turbine liner 24 that constitutes the torque converter 22 is detected by a turbine rotation sensor 56 . The detected turbine speed is output to a transmission control unit (hereinafter referred to as "TCU") 50, which will be described later.

The forward/reverse switching mechanism 27 switches the drive wheels 10 (the left front wheel 10FL, the right front wheel 10FR, the left rear wheel 10RL, and the right rear wheel 10RR) between forward and reverse rotation (forward and reverse of the vehicle). The forward/reverse switching mechanism 27 mainly includes a double pinion planetary gear train, a forward clutch 28 and a reverse brake 29 . The forward/reverse switching mechanism 27 is configured to be able to switch the transmission path of the engine driving force by controlling the respective states of the forward clutch 28 and the reverse brake 29 .

More specifically, when the D (drive) range is selected, the forward clutch 28 is engaged and the reverse brake 29 is released, so that the rotation of the turbine shaft 31 is directly transmitted to the primary shaft 32, which will be described later. , the vehicle can be driven forward. On the other hand, when the R (reverse) range is selected, the forward clutch 28 is released and the reverse brake 29 is engaged to operate the planetary gear train and reverse the rotation direction of the primary shaft 32. , the vehicle can be driven backward.

Further, when the N (neutral) range or the P (parking) range is selected, the forward clutch 28 and the reverse brake 29 are released so that the turbine shaft 31 and the primary shaft 32 are separated (transmission of the engine driving force is stopped). is blocked), and the forward/reverse switching mechanism 27 enters a neutral state in which no power is transmitted to the primary shaft 32 . The operations of the forward clutch 28 and the reverse brake 29 are controlled by the TCU 50 and the valve body (control valve) 60.

A transmission mechanism (variator) 33 of the continuously variable transmission 30 includes a primary shaft 32 connected to a turbine shaft 31 of the torque converter 22 via a forward/reverse switching mechanism 27 and a secondary shaft 32 arranged parallel to the primary shaft 32 . and an axis 37 . A primary pulley 34 is provided on the primary shaft 32 . The primary pulley 34 has a fixed sheave 34a joined to the primary shaft 32, and a movable sheave 34b facing the fixed sheave 34a and slidably mounted in the axial direction of the primary shaft 32. The configuration is such that the cone surface interval of the sheaves 34a and 34b, that is, the pulley groove width can be changed. On the other hand, the secondary shaft 37 is provided with a secondary pulley 35 . The secondary pulley 35 has a fixed sheave 35a joined to the secondary shaft 37 and a movable sheave 35b slidably mounted in the axial direction of the secondary shaft 37 so as to face the fixed sheave 35a. It is configured so that the width can be changed.

A chain 36 for transmitting driving force is stretched between the primary pulley 34 and the secondary pulley 35 . By changing the groove widths of the primary pulley 34 and the secondary pulley 35 to change the ratio of the winding diameter of the chain 36 to the pulleys 34 and 35 (pulley ratio), the gear ratio can be changed steplessly.

A hydraulic chamber 34c is formed in the primary pulley 34 (movable sheave 34b). On the other hand, a hydraulic chamber 35c is formed in the secondary pulley 35 (movable sheave 35b). The groove widths of the primary pulley 34 and the secondary pulley 35 are set and changed by adjusting the primary hydraulic pressure introduced into the hydraulic chamber 34c of the primary pulley 34 and the secondary hydraulic pressure introduced into the hydraulic chamber 35c of the secondary pulley 35. be done.

A secondary shaft 37 of the transmission mechanism 33 is connected to a counter shaft 39 via a reduction gear 38 consisting of a pair of gears (a reduction drive gear and a reduction driven gear). 38 to the counter shaft 39 . A parking gear 114 that constitutes a parking mechanism 110 is attached to the counter shaft 39 . That is, the secondary shaft 37 and the counter shaft 39 correspond to output shafts described in claims.

Here, the parking mechanism 110 of the continuously variable transmission 30 will be described with reference to FIG. 2 . The parking mechanism 110 is a mechanism that locks rotation inside the continuously variable transmission so that the wheels 10 do not rotate when the P (parking) range is selected. A detend plate 111 is attached to the output shaft of an SBW actuator 85 (for example, an electric motor) driven by a shift-by-wire control unit (hereinafter referred to as "SBW-CU") 80, which will be described later. A parking rod 112 is connected to the detend plate 111 so as to move back and forth in the axial direction. On the other hand, as described above, the parking gear 114 is spline-fitted to the counter shaft 39 of the continuously variable transmission 30 . Also, a parking pole 113 is swingably provided so as to engage with the parking gear 114 .

When the P (parking) range is selected, the SBW actuator 85 (electric motor) is rotated to swing the detend plate 111 and advance the parking rod 112 in the axial direction. The tapered portion of the parking rod 112 pushes the parking pole 113 from the rear side to swing and mesh with the parking gear 114 . Thereby, the rotation of the continuously variable transmission 30 is locked. The parking mechanism 110 is configured such that the parking pole 113 is repelled by the parking gear 114 when the vehicle speed exceeds a predetermined speed, and the parking pole 113 and the parking gear 114 cannot mesh with each other.

Returning to FIG. 1, the counter shaft 39 is connected to a front drive shaft 43 via a counter gear 40 consisting of a pair of gears (counter drive gear, counter driven gear). The driving force transmitted to the counter shaft 39 is transmitted to a front differential (hereinafter also referred to as “front differential”) 44 via a counter gear 40 and a front drive shaft 43 . The front differential 44 is, for example, a bevel gear differential. The driving force from the front differential 44 is transmitted to the front left wheel 10FL via a front left wheel drive shaft 45L and to the front right wheel 10FR via a front right wheel drive shaft 45R.

On the other hand, a transfer clutch 41 for adjusting the driving force transmitted to the rear differential 47 is interposed at the rear stage of the counter gear 40 (counter drive gear) on the counter shaft 39 described above. The transfer clutch 41 controls the engagement force (that is, the torque distribution ratio to the rear wheels 10RL and 10RR) according to the drive state of the four wheels (for example, the slip state of the front wheels 10FL and 10FR) and the engine torque. Therefore, the driving force transmitted to the counter shaft 39 is distributed according to the engagement force of the transfer clutch 41, and is also transmitted to the rear wheels 10RL and 10RR.

More specifically, the rear end of the counter shaft 39 is connected to a propeller shaft 46 extending rearward of the vehicle via a transfer gear 42 consisting of a pair of gears (transfer drive gear, transfer driven gear). Therefore, the driving force transmitted to the counter shaft 39 and adjusted (distributed) by the transfer clutch 41 is transmitted from the transfer gear 42 (transfer driven gear) to the rear differential 47 via the propeller shaft 46 .

A left rear wheel drive shaft 48L and a right rear wheel drive shaft 48R are connected to the rear differential 47 . The driving force from the rear differential 47 is transmitted to the left rear wheel 10RL via the left rear wheel drive shaft 48L and to the right rear wheel 10RR via the right rear wheel drive shaft 48R.

A shift lever 55 for receiving a shift operation by the driver is provided on the floor (center console) or the like of the vehicle. A range switch 54 is attached to the shift lever 55 so as to move in conjunction with the shift lever 55 to detect the selected position of the shift lever 55 . The range switch 54 is connected to the TCU 50 , and the detected selected position of the shift lever 55 is read into the TCU 50 . In other words, the shift lever 55 and the range switch 54 function as selecting means described in the claims. The shift lever 55 has five shift ranges: parking range (parking (P) range), reverse travel range (reverse (R) range), neutral range (neutral (N) range), and forward travel range (drive range). (D) range) and manual range (manual (M) range) can be selectively switched.

By configuring the driving force transmission system of the power train as described above, for example, when the shift lever 55 is operated to the D range, the forward clutch 28 is engaged and the engine driving force is transferred to the continuously variable transmission. 30 is input to the primary axis 32 . The driving force converted by the continuously variable transmission 30 is output from the secondary shaft 37 and transmitted to the front drive shaft 43 via the reduction gear 38 , the counter shaft 39 and the counter gear 40 . Driving force is distributed to the left and right by the front differential 44 and transmitted to the left and right front wheels 10FL and 10FR. Therefore, the left and right front wheels 10FL and 10FR are always driven when the vehicle 4 is in the running state.

On the other hand, part of the driving force transmitted to the counter shaft 39 is transmitted to the propeller shaft 46 via the transfer clutch 41 and the transfer gear 42 . Here, when a predetermined clutch torque is applied to the transfer clutch 41 , driving force distributed according to the clutch torque is output to the propeller shaft 46 . The driving force is also transmitted to the rear wheels 10RL and 10RR via the rear differential 47. As a result, it functions as a FF-based part-time AWD vehicle.

A valve body (control valve) 60 controls the hydraulic pressure for shifting the continuously variable transmission 30 , that is, the primary hydraulic pressure and the secondary hydraulic pressure described above. The valve body 60 adjusts the hydraulic pressure discharged from the oil pump by opening and closing an oil passage formed in the valve body 60 using a spool valve and a solenoid valve (electromagnetic valve) that moves the spool valve. It is supplied to the hydraulic chamber 34 c of the primary pulley 34 and the hydraulic chamber 35 c of the secondary pulley 35 . Similarly, the valve body 60 adjusts the hydraulic pressure discharged from the oil pump by opening and closing an oil passage formed in the valve body 60 using a spool valve and a solenoid valve that moves the spool valve, thereby moving forward. Hydraulic pressure is supplied to the clutch 28, the reverse brake 29, and the transfer clutch 41 to engage and disengage the clutches.

Transmission control of continuously variable transmission 30 is performed by TCU 50 . That is, the TCU 50 adjusts the hydraulic pressure supplied to the hydraulic chamber 34c of the primary pulley 34 and the hydraulic chamber 35c of the secondary pulley 35 by controlling the driving of the solenoid valve (electromagnetic valve) that constitutes the valve body 60 described above. , to change the gear ratio of the continuously variable transmission 30 . Similarly, the TCU 50 adjusts the hydraulic pressure supplied to the transfer clutch 41 by controlling the driving of the solenoid valves forming the valve body 60 described above, and the distribution ratio of the driving force transmitted to the rear wheels 10RL and 10RR. adjust the

In addition, the TCU 50 controls the drive of the clutch linear solenoid 60a that constitutes the valve body 60, thereby adjusting the hydraulic pressure supplied to the forward clutch 28 or the reverse brake 29 to engage or release the forward clutch 28 or the reverse brake 29. I do. A manual valve (not shown) that operates in conjunction with the detend plate 111 determines whether the hydraulic pressure (oil) regulated by the clutch solenoid 60a is supplied to the forward clutch 28 side or the reverse brake 29 side. switched by

Here, the TCU 50 is communicably connected to an ECU 70 that comprehensively controls the engine 20, an SBW-CU 80, a meter control unit (hereinafter referred to as "MCU") 90, etc., via a CAN (Controller Area Network) 100. It is

The ECU 70 determines the cylinder from the output of the cam angle sensor and obtains the engine speed from the change in rotational position of the crankshaft detected by the output of the crank angle sensor 75 . Further, the ECU 70 acquires various types of information such as the amount of intake air, the opening degree of the accelerator pedal, the air-fuel ratio of the air-fuel mixture, and the water temperature based on the detection signals input from the various sensors described above. Then, the ECU 70 comprehensively controls the engine 20 by controlling the fuel injection amount, the ignition timing, and various devices such as the throttle valve based on the acquired various information.

The ECU 70 also calculates the engine shaft torque (output torque) of the engine 20 based on the amount of intake air detected by the airflow meter 71 . Then, the ECU 70 transmits information such as engine water temperature (cooling water temperature), engine shaft torque, engine speed, and accelerator pedal opening through the CAN 100 .

The TCU 50 includes an output shaft rotation sensor 52 (corresponding to the rotation sensor described in the claims) attached near the secondary shaft 37 of the continuously variable transmission 30 to detect the rotation speed of the secondary shaft 37, and a primary pulley. A primary pulley rotation sensor 53 for detecting the number of revolutions of 34 is connected. As the output shaft rotation sensor 52 and the primary pulley rotation sensor 53, for example, a magnetic pickup, an MR element, or the like is preferably used. A range switch 54 for detecting a selected position (shift position) of a shift lever 55 is connected to the TCU 50 . Further, the TCU 50 is also connected with the above-described turbine rotation sensor 56 and an oil temperature sensor 57 for detecting the oil temperature of the continuously variable transmission 30 .

The TCU 50 includes a microprocessor that performs calculations, an EEPROM that stores programs and various maps for causing the microprocessor to execute various processes, a RAM that stores various data such as calculation results, and a battery that holds the stored contents. It is configured with a backup RAM, an input/output I/F, and the like.

The TCU 50 automatically and steplessly shifts the gear ratio in accordance with the shift map and according to the operating conditions of the vehicle (for example, accelerator pedal position, vehicle speed, or engine speed). Note that the shift map is stored in the EEPROM or the like in the TCU 50. FIG. In addition, the TCU 50 executes transfer clutch control (AWD control) based on various information obtained from various sensors and the like described above. The TCU 50 transmits various kinds of information such as the shift position and the rotation speed of the secondary shaft to the SBW-CU 80 via the CAN 100 .

The SBW-CU 80 receives various information such as the shift position and output shaft rotation speed via the CAN 100 . The SBW-CU 80 generates and outputs a control signal (motor drive signal) to drive the SBW actuator 85 based on the received various information including the shift position. SBW-CU 80 functions as a control unit described in the claims. The SBW-CU 80 also transmits information indicating that ratcheting is occurring (details will be described later) to the MCU 90 via the CAN 100 .

SBW actuator 85 moves a manual valve (not shown) interlocking with detend plate 111 in response to a control signal from SBW-CU 80 to switch the shift range of continuously variable transmission 30 . Note that the SBW-CU 80 and the SBW actuator 85 may be configured integrally. An electric motor, for example, is preferably used as the SBW actuator 85 .

In particular, the SBW-CU 80 has a function of suppressing wear of the parking gear 114 and the parking pole 113 due to ratcheting in which the pawl of the parking pole 113 is repeatedly flipped by the teeth of the parking gear 114 . In the SBW-CU 80, the functions described above are realized by executing a program stored in an EEPROM or the like by a microprocessor.

The SBW-CU 80 determines whether ratcheting occurs in which the pawl of the parking pole 113 is repeatedly flipped by the teeth of the parking gear 114 when the shift range of the continuously variable transmission 30 is switched to the parking range while the vehicle is running. (Detect the occurrence of ratcheting). When the SBW-CU 80 determines that ratcheting has occurred (detects the occurrence of ratcheting), the SBW-CU 80 automatically switches the shift range of the continuously variable transmission 30 to the neutral range.

More specifically, the SBW-CU 80 first obtains the rotation fluctuation (rotation fluctuation rate) of the rotation speed of the secondary shaft 37 per unit time (for example, each sampling period) based on the following equation (1).
Rotational speed fluctuation rate = {(current value - previous value)/previous value}*100 (1)

Then, the SBW-CU 80 performs ratcheting when the rotation fluctuation (rotation fluctuation rate) of the rotation speed of the secondary shaft 37 per unit time (for each sampling period) is equal to or greater than a predetermined threshold value (for example, 20%). is determined to occur. In particular, the SBW-CU 80 determines that ratcheting is occurring when the average value of rotation fluctuations (rotation fluctuation rate) in a predetermined time period (eg, 1 second) is equal to or greater than a predetermined threshold value (eg, 20%). judge.

In such a ratcheting determination method (detection method), in a ratcheting state in which the parking pole 113 continuously hits the parking gear 114, the output signal of the output shaft rotation sensor 52 is affected by gear backlash. This is based on the knowledge that noise-like whisker-like waveforms appear in

Note that the SBW-CU 80 preferably varies the predetermined time according to the vehicle speed. The SBW-CU 80 shortens the predetermined time, for example, as the vehicle speed increases. This is because the higher the vehicle speed, the shorter the period of appearance of the above-described whisker-like waveform. The predetermined time and threshold can be arbitrarily set according to, for example, the backlash of the shaft and the specifications of the operation system parts.

Information (abnormality information) indicating that the ratcheting described above has occurred and information indicating that the shift range has been automatically switched to the neutral range are sent to the MCU 90 via the CAN 100 . The MCU 90 is connected to, for example, a display unit 91 having an LCD display or the like arranged in a meter or on the upper part of a dashboard, and drives the display unit 91 to display, for example, the vehicle, the engine 20, or the vehicle. The state of the stepped transmission 30 and various information are presented to the driver.

In particular, the MCU 90 issues a warning to the driver when ratcheting is detected or when the shift range is automatically switched to the neutral range. That is, the MCU 90 and the display section 91 function as a presentation section described in the claims. At that time, the MCU 90 drives the display unit 91 to, for example, turn on a warning light, or display characters such as "ratcheting is occurring" and "shift range has been switched to neutral". preferably. Also, a warning sound may be output at the same time.

Next, the operation of the shift control device 1 will be described with reference to FIG. FIG. 3 is a flowchart showing a processing procedure of shift range (parking range) switching processing by the shift control device 1 . SBW-CU 80 mainly repeats this process at a predetermined timing.

In step S100, information such as the secondary shaft rotation speed and vehicle speed is read.

Next, in step S102, it is determined whether or not the P range has been selected (whether or not there is a request to switch to the P range) while the vehicle is running (for example, at a vehicle speed of 10 km/h or more). to P range or from R range to P range. Here, when the P range is not selected, this processing is temporarily exited. On the other hand, when the P range is selected, the process proceeds to step S104.

At step S104, the switching operation to the P range is started. That is, the driving of the SBW actuator 85 (parking pole 113) is started.

Subsequently, in step S106, a determination is made as to whether or not ratcheting has occurred. The method for determining whether or not ratcheting has occurred is as described above, and detailed description thereof will be omitted here. Here, if ratcheting does not occur, this processing is temporarily exited. On the other hand, when ratcheting occurs, the process proceeds to step S108.

At step S108, the shift range of the continuously variable transmission 30 is automatically switched to the neutral range. Then, in subsequent step S110, information indicating that ratcheting is occurring (abnormal information) and information indicating that the shift range has been automatically switched to the neutral range are presented. After that, this processing is temporarily exited.

As described in detail above, according to the present embodiment, the shift range is automatically switched to the neutral range when occurrence of ratcheting is detected. Ratcheting is thereby eliminated. As a result, for example, even if the parking range is selected during driving by an erroneous operation, it is possible to suppress wear of the parking gear 114 and the parking pole 113 due to ratcheting.

According to the present embodiment, the rotation fluctuation (rotation fluctuation rate) of the number of rotations of the secondary shaft per unit time (for each sampling period) is obtained, and the rotation fluctuation (rotation fluctuation rate) is averaged over a predetermined period of time (for example, one second). Ratcheting is determined to be occurring when the value is greater than or equal to a predetermined threshold (eg, 20%). Therefore, ratcheting can be accurately detected while preventing erroneous determination (erroneous detection).

According to the present embodiment, when it is determined that ratcheting is occurring or when the shift range is automatically switched to the neutral range, information indicating that ratcheting is occurring (abnormal information) Alternatively, the driver or the like is presented with information indicating that the shift range has been automatically switched to the neutral range. Therefore, the driver or the like can be made to recognize (recognize) that ratcheting is occurring or that the gear has been switched to neutral.

According to the present embodiment, the predetermined time (the predetermined time for determining whether or not ratcheting occurs) for obtaining the average value of the rotation fluctuation (rotation fluctuation rate) of the secondary shaft rotation speed is The faster it gets, the shorter it gets. Therefore, it is possible to detect the occurrence of ratcheting more quickly while preventing erroneous detection.

According to this embodiment, the occurrence of ratcheting can be detected using the output shaft rotation sensor 52 that detects the rotation speed of the secondary shaft 37 of the continuously variable transmission 30 (the rotation speed of the secondary pulley 35). That is, an existing rotation sensor can be used (appropriated). Therefore, there is no need to provide a new rotation sensor, and an increase in cost and man-hours can be suppressed.

Next, shift range (parking range) switching processing when the shift control device has a parking inhibit function will be described with reference to FIG. FIG. 4 is a flowchart showing a procedure of shift range (parking range) switching processing by a shift control device (shift control device according to a modification) having a parking inhibit function.

In step S200, information such as the secondary shaft rotation speed and vehicle speed is read.

Next, in step S202, it is determined whether or not the P range has been selected (whether or not there is a request to switch to the P range) while the vehicle is running (for example, at a vehicle speed of 10 km/h or more). to P range or from R range to P range. Here, when the P range is not selected, this processing is temporarily exited. On the other hand, when the P range is selected, the process proceeds to step S204.

In step S204, a determination is made as to whether the parking inhibit function has failed (whether it is out of order). Here, if the parking inhibit function has failed, the process proceeds to step S206. On the other hand, when the parking inhibit function is normal, switching to the parking range is prohibited in step S214, after which the process exits.

At step S206, the switching operation to the P range is started. That is, the driving of the SBW actuator 85 (parking pole 113) is started.

Subsequently, in step S208, a determination is made as to whether or not ratcheting has occurred. The method for determining whether or not ratcheting has occurred is as described above, and detailed description thereof will be omitted here. Here, if ratcheting does not occur, this processing is temporarily exited. On the other hand, when ratcheting occurs, the process proceeds to step S210.

In step S210, the shift range of continuously variable transmission 30 is automatically switched to the neutral range. Then, in subsequent step S212, information indicating that ratcheting is occurring (abnormal information) and information indicating that the shift range has been automatically switched to the neutral range are presented. After that, this processing is temporarily exited.

In this way, even if the parking inhibit function fails, it is possible to suppress wear of the parking gear 114 and the parking pole 113 due to ratcheting.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible. For example, in the above embodiments, the present invention is applied to a chain-type continuously variable transmission (CVT), but instead of the chain-type continuously variable transmission, for example, a belt-type continuously variable transmission or a toroidal-type continuously variable transmission It can also be applied to a continuously variable transmission and the like. Further, it can be applied to a stepped automatic transmission (step AT) instead of the continuously variable transmission. Further, in the above embodiment, an AWD vehicle was used as an example, but the present invention can also be applied to, for example, an FF vehicle. Furthermore, the present invention is applicable to HEV (hybrid vehicle), PHEV (plug-in hybrid vehicle), EV (electric vehicle), FCV (fuel cell vehicle), and the like.

In the above embodiment, the TCU 50, the ECU 70, the SBW-CU 80, and the MCU 90 are connected to each other via the CAN 100 so as to be able to communicate with each other. It can be arbitrarily changed in consideration of requirements, costs, and the like. For example, the SBW-CU 80 and SBW actuator 85 may be integrated, or the TCU 50 and SBW-CU 80 may be integrated into one unit. Further, in the above embodiment, the SBW-CU 80 detects ratcheting, etc., but the TCU 50 may be used.

In the above-described embodiment, the output shaft rotation sensor 52 provided on the secondary shaft 37 is used to detect ratcheting. good too. For example, a rotation speed sensor that detects the rotation speed of the counter shaft 39, a primary pulley rotation sensor 53 that detects the rotation speed of the primary pulley 34, or the like may be used.

Further, the configuration of the driving force transmission system described above (for example, arrangement of gears, shafts, etc.) is an example, and is not limited to the above embodiment. For example, in the above embodiment, the forward/reverse switching mechanism 27 is arranged on the upstream side of the transmission mechanism (variator) 33 , but it may be arranged on the downstream side of the transmission mechanism 33 .

1 shift control device 20 engine 22 torque converter 27 forward/reverse switching mechanism 28 forward clutch 29 reverse brake 30 continuously variable transmission 33 transmission mechanism 37 secondary shaft 39 counter shaft 41 transfer clutch 50 TCU
52 Output shaft rotation sensor 53 Primary pulley rotation sensor 54 Range switch 55 Shift lever 56 Turbine rotation sensor 57 Oil temperature sensor 60 Valve body 70 ECU
80 SBW-CU
85 SBW actuator 90 MCU
91 display unit 100 CAN
110 parking mechanism 113 parking pole 114 parking gear

Claims (5)

selecting means for receiving an operation for selecting a shift range of an automatic transmission and outputting selection information according to the operation;
a control unit that switches the shift range of the automatic transmission according to selection information output by the selecting means;
a parking mechanism having a parking gear and a parking pole, wherein the parking pole engages the parking gear to lock the rotation of the automatic transmission and set the shift range of the automatic transmission to the parking range;
When the shift range of the automatic transmission is switched to the parking range, the control unit determines whether or not ratcheting occurs in which the pawl of the parking pole is repeatedly flipped by the teeth of the parking gear. A shift control device that switches the shift range of the automatic transmission to a neutral range when it is determined that a shift occurs. A rotation sensor for detecting the rotation speed of the output shaft of the automatic transmission provided with the parking gear,
2. The control unit according to claim 1, wherein the control unit determines that ratcheting occurs when a rotation fluctuation of the number of rotations of the output shaft per unit time is equal to or greater than a predetermined threshold value. shift control device. 3. The control unit according to claim 1, wherein the control unit determines that ratcheting occurs when an average value of the rotational fluctuations for a predetermined period of time is equal to or greater than the predetermined threshold value. Shift control device. 4. The shift control device according to claim 3, wherein the control unit varies the predetermined time according to vehicle speed. 5. The apparatus according to any one of claims 1 to 4, further comprising a presentation unit that presents that ratcheting is occurring when the control unit determines that ratcheting is occurring. A shift control device as described.

Images