JP6434345B2 - Transfer clutch control device - Google Patents

Description

  The present invention relates to a transfer clutch control device, and more particularly to a transfer clutch control device for an AWD vehicle (all-wheel drive vehicle) equipped with an automatic transmission having a parking mechanism that locks an output shaft.

  Generally, driving force output from an engine is input to an automatic transmission via a torque converter, converted by the automatic transmission, and then driven via a power transmission system including gears, a drive shaft, and the like. Transmitted to the wheel. Therefore, for example, when the shift position is in the D range (forward travel position) or R range (reverse travel position) and the brake pedal is depressed and the vehicle is stopped, the engine torque input via the torque converter As a result, the drive shaft constituting the power transmission system is twisted.

  On the other hand, in the automatic transmission, when the P range (parking position) is selected, the parking gear fitted to the output shaft of the automatic transmission is locked (that is, the output shaft is fixed). Therefore, when the parking gear is locked in a state where the drive shaft and the like constituting the power transmission system are twisted as described above, the twisted state of the drive shaft and the like constituting the power transmission system is maintained. Become. Then, when shifting from the P range to another range (for example, the D range), the parking gear is unlocked, and when the held torsion is released, the accumulated torsion torque is used. When the parking gear, the drive shaft, and the like rotate, shock, vibration, or abnormal noise may occur, which may cause the passenger to feel uncomfortable.

  In order to solve such a problem, Patent Document 1 discloses an automatic transmission control device provided with a lock unit that mechanically stops the rotation of the output shaft when the P range is selected. And a means for gradually releasing the engagement of the friction engagement member when shifted from the P range to another range. A control device for an automatic transmission is disclosed. According to this automatic transmission control device, the friction engagement member is gradually released when the lock means is shifted from the P range to another range, so that the output shaft is not released immediately. As a result, even if torsional torque is accumulated in the power transmission system including the output shaft, the output shaft does not rotate suddenly, and shocks and vibrations caused by the torsional torque can be prevented. .

Japanese Patent Laid-Open No. 9-152031

  As described above, according to the technique described in Patent Document 1, it is possible to prevent shocks and noises associated with the release of torsional torque accumulated as torsional deformation. However, in the technique of Patent Document 1, when the P range is selected (when the parking gear is locked) in a state where the drive shaft and the like constituting the power transmission system are twisted, the parking gear and the parking pole No consideration is given to the abnormal noise caused by the contact with.

  That is, when the P range is selected and the parking gear fitted to the output shaft of the automatic transmission is locked in a state where the drive shaft and the like constituting the power transmission system are twisted as described above. For example, until the forward clutch is released and the parking gear and the parking pawl are fitted, the twist of the drive shaft constituting the power transmission system is released, the parking gear rotates, the parking gear and the parking pole A rattling noise (abnormal noise) may occur due to contact.

  However, in the technology described in Patent Document 1, it is not considered to prevent such rattling noise caused by contact between the parking gear and the parking pole. Could not be prevented.

  The present invention has been made to solve the above problems, and is a control device for a transfer clutch of an AWD vehicle equipped with an automatic transmission having a parking mechanism that locks an output shaft. Another object of the present invention is to provide a transfer clutch control device capable of reducing rattling noise (abnormal noise) between a parking gear and a parking pole.

  A transfer clutch control device according to the present invention is a transfer clutch control device for an all-wheel drive vehicle equipped with an automatic transmission having a parking mechanism that includes a parking gear and a parking pole and locks an output shaft. A vehicle speed detecting means for detecting speed, a brake operation detecting means for detecting an operation state of a brake for braking the vehicle, and a driving force transmitted from the speed change mechanism constituting the automatic transmission to the drive system on the driven wheel side is adjusted. And a transfer clutch control means for controlling the fastening force of the transfer clutch based on the driving state of the vehicle, wherein the transfer clutch control means is operated by a brake and the speed of the vehicle is a predetermined speed. Release the transfer clutch when: It has been characterized by fastening the transfer clutch when the speed of the vehicle is zero.

  According to the transfer clutch control device of the present invention, when the speed of the vehicle becomes equal to or lower than a predetermined speed (for example, extremely low vehicle speed just before stopping) in a state where the brake is operated (the vehicle is braked). That is, the transfer clutch is temporarily released immediately before the vehicle is stopped by operating the brake and the drive shaft of the power transmission system can be twisted. After that, when the vehicle is stopped while the brake is operated (the vehicle is braked), the transfer clutch is re-engaged. Therefore, when the brake is operated and the vehicle is stopped by this series of operations, the drive shaft and the like constituting the power transmission system between the automatic transmission and the transfer clutch are twisted. A state in which no torsion is generated is created in the drive shaft and the like constituting the power transmission system between the clutch and the drive wheel. Therefore, when the P (parking) range is subsequently selected and the parking gear is locked, the automatic transmission and the automatic transmission are controlled by the shaft rigidity of the drive shaft that constitutes the power transmission system between the transfer clutch and the drive wheels. The rotation of the parking gear caused by releasing the twist of the drive shaft and the like between the transfer clutch and the transfer clutch is suppressed. As a result, it is possible to reduce rattling noise (abnormal noise) between the parking gear and the parking pole when the parking range is selected. In this case, since the transfer clutch is once released before the vehicle completely stops and the transfer clutch is re-engaged when the vehicle stops, the driver selects the P range immediately after the vehicle stops. In addition, the rattling noise between the parking gear and the parking pole can be reduced.

  In the transfer clutch control device according to the present invention, the predetermined speed is zero, and the transfer clutch control means once releases the transfer clutch when the brake is operated and the vehicle speed becomes zero. After that, it is preferable to fasten again.

  In this case, when the brake is operated (brake) and the vehicle stops, the transfer clutch is once released and then re-engaged. Therefore, as described above, the drive shaft and the like constituting the power transmission system between the automatic transmission and the transfer clutch are twisted, but the power transmission system between the transfer clutch and the drive wheel is configured. A state in which the drive shaft or the like is not twisted is created. Therefore, when the P (parking) range is selected and the parking gear is locked, the automatic transmission and the automatic transmission are controlled by the shaft rigidity of the drive shaft and the like constituting the power transmission system between the transfer clutch and the drive wheels. The rotation of the parking gear caused by releasing the twist of the drive shaft and the like between the transfer clutch and the transfer clutch is suppressed. As a result, it is possible to reduce rattling noise (abnormal noise) between the parking gear and the parking pole when the parking range is selected.

  In the transfer clutch control device according to the present invention, it is preferable that the transfer clutch control means prohibits the release and re-engagement of the transfer clutch when the shift range of the automatic transmission is the neutral range.

  When the shift range of the automatic transmission is the neutral range, no driving force is applied, so that the drive shaft and the like constituting the power transmission system are not twisted. Therefore, when the parking gear is locked, no rattling noise is generated between the parking gear and the parking pole. Therefore, in such a case, it is possible to prevent unnecessary operations from being performed by prohibiting the release and re-engagement of the transfer clutch.

  A transfer clutch control device according to the present invention receives an operation for selecting a shift range of an automatic transmission, outputs selection information according to the operation, and automatically selects the output according to the selection information output by the selection unit. Switching means for switching the shift range of the transmission, and when the operation for selecting the parking range is accepted by the selection means, the transfer clutch control means automatically applies to the switching means after the transfer clutch is re-engaged. It is preferable to allow the shift range of the transmission to be switched to the parking range.

  In this case, the transfer clutch is once released and then re-engaged, and then the shift range of the automatic transmission is switched to the parking range. Therefore, for example, even if the P (parking) range is selected at the same time as the vehicle stops or immediately before the vehicle stops, the rattling noise between the parking gear and the parking pole can be reliably reduced. Is possible.

  According to the present invention, in an AWD vehicle (all-wheel drive vehicle) equipped with an automatic transmission having a parking mechanism that locks an output shaft, a rattling noise (abnormal noise) between a parking gear and a parking pole when a parking range is selected. ) Can be reduced.

1 is a block diagram illustrating a configuration of a transfer clutch control device according to an embodiment, and a power train and a driving force transmission system of an AWD vehicle in which the control device is mounted. It is a figure which shows the structure of the parking mechanism of a continuously variable transmission. It is a flowchart which shows the process sequence of the transfer clutch control (tooth rattling sound reduction control) by the control apparatus of the transfer clutch which concerns on embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Moreover, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  First, the configuration of the transfer clutch 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 transfer clutch control device 1 and the power train and driving force transmission system of an AWD (All Wheel Drive) vehicle equipped with the control device. FIG. 2 is a diagram showing a configuration of the parking mechanism 110 of the continuously variable transmission (CVT) 30. In the present embodiment, a 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 is, for example, a horizontally opposed four-cylinder gasoline engine. The output shaft (crankshaft) 21 of the engine 20 is a continuously variable that converts and outputs the driving force from the engine 20 via a torque converter 22 having a clutch function and a torque amplification function and a forward / reverse switching mechanism 27. A transmission (corresponding to the automatic transmission described in the claims) 30 is connected.

  The torque converter 22 mainly includes a pump impeller 23, a turbine liner 24, and a stator 25. A pump impeller 23 connected to the output shaft 21 generates an oil flow, and a turbine liner 24 disposed facing the pump impeller 23 receives the power of the engine 20 via the oil to drive the output shaft. The stator 25 located between them rectifies the exhaust flow (return) from the turbine liner 24 and reduces it to the pump impeller 23 to generate a torque amplifying action. The torque converter 22 has a lock-up clutch 26 that directly connects the input and the output. The torque converter 22 amplifies the torque of the driving force of the engine 20 and transmits it to the continuously variable transmission 30 when in the non-lock-up state, and directly transmits the driving force of the engine 20 to the continuously variable transmission 30 during the lock-up. .

  The forward / reverse switching mechanism 27 switches between forward rotation and reverse rotation (vehicle forward and reverse) of 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). 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 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, whereby the rotation of the turbine shaft 31 is directly transmitted to the primary shaft 32 described later. The vehicle can be moved forward. On the other hand, when the R (reverse) range is selected, the planetary gear train can be operated to reverse the rotation direction of the primary shaft 32 by releasing the forward clutch 28 and engaging the reverse brake 29. It becomes possible to drive the vehicle backward.

  Further, when the N (neutral) range or the P (parking) range is selected, the turbine shaft 31 and the primary shaft 32 are disconnected by releasing the forward clutch 28 and the reverse brake 29, and the forward / reverse switching mechanism 27 is A neutral state in which power is not transmitted to the primary shaft 32 is established. The operations of the forward clutch 28 and the reverse brake 29 are controlled by a transmission control device (hereinafter also referred to as “TCU”) 50 and a valve body (control valve) 60 which will be described later.

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

  A chain 36 that transmits driving force is stretched between the primary pulley 34 and the secondary pulley 35. By changing the groove width of the primary pulley 34 and the secondary pulley 35 and changing the ratio of the winding diameter of the chain 36 to the pulleys 34 and 35 (pulley ratio), the transmission ratio is changed steplessly.

  Here, a hydraulic chamber 34c is formed in the primary pulley 34 (movable pulley 34b). On the other hand, a hydraulic chamber 35c is formed in the secondary pulley 35 (movable pulley 35b). The groove width of each of the primary pulley 34 and the secondary pulley 35 is 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. Is done.

  The secondary shaft 37 of the speed change mechanism 33 is connected to a counter shaft 39 via a reduction gear 38 made up of a pair of gears (a reduction drive gear and a reduction driven gear), and the driving force converted by the speed change mechanism 33 is reduced. It is transmitted to the counter shaft 39 via 38. A parking gear 114 is attached to the counter shaft 39.

  Here, the parking mechanism 110 of the continuously variable transmission 30 will be described with reference to FIG. The parking mechanism 110 is a mechanism that locks the rotation inside the continuously variable transmission so that the wheel 10 does not rotate when the P (parking) range is selected. A detent plate 111 is attached to an output shaft of an SBW actuator 81 (for example, an electric motor) driven by a shift-by-wire control unit (hereinafter referred to as “SBW-CU”) 80 described later. A parking rod 112 is connected to the detent plate 111 so as to be movable 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. The parking pole 113 is swingably provided so as to be able to mesh with the parking gear 114.

  When the P (parking) range is selected, when the SBW actuator 81 (electric motor) is rotated, the detent plate 111 swings and the parking rod 112 advances in the axial direction. Then, the parking pole 113 is pushed from the back by the taper portion of the parking rod 112 and swings to engage with the parking gear 114. Thereby, rotation of continuously variable transmission 30 is locked.

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

  On the other hand, a transfer clutch 41 that adjusts the driving force transmitted to the rear differential 50 is interposed downstream of the counter gear 40 (counter drive gear) on the counter shaft 39 described above. The transfer clutch 41 is changed to a fastening force (that is, rear wheels 10RL, 10RR (corresponding to the sub-driven wheels in the claims)) according to the driving state of the four wheels (for example, the slip state of the front wheels 10FL, 10FR) and the engine torque. Torque distribution ratio) is controlled. Therefore, the driving force transmitted to the counter shaft 39 is distributed according to the fastening force of the transfer clutch 41 and is also transmitted to the rear wheels 10RL and 10RR side.

  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 including 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 is also transmitted 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) of the vehicle. A range switch 54 is connected to the shift lever 55 so as to move in conjunction with the shift lever 55 and detects a 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. That is, the shift lever 55 and the range switch 54 function as selection means described in the claims. The shift lever 55 has five shift ranges, that is, a parking range (parking (P) range), a reverse travel range (reverse (R) range), a neutral range (neutral (N) range), and a forward travel range (drive). (D) range) and manual range (manual (M) range) can be selectively switched.

  As described above, the driving force transmission system of the power train is configured. 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 continuously variable. 30 primary shafts 32 are input. 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. Then, the driving force is distributed to the left and right by the front differential 44 and transmitted to the left and right front wheels 10FL, 10FR. Therefore, the left and right front wheels 10FL, 10FR are always driven when the vehicle 4 is in a traveling 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, the 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, the function as an FF-based part-time AWD vehicle is exhibited.

  The hydraulic pressure for shifting the continuously variable transmission 30, that is, the primary hydraulic pressure and the secondary hydraulic pressure described above are controlled by a valve body (control valve) 60. 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 (solenoid valve) that moves the spool valve, The oil 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 moves forward by adjusting 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. Hydraulic pressure for engaging / disengaging each clutch is supplied to the clutch 28, the reverse brake 29, and the transfer clutch 41.

  Shift control of the continuously variable transmission 30 is executed by the 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) constituting the valve body 60 described above. The gear ratio of the continuously variable transmission 30 is changed. Similarly, the TCU 50 controls the drive of the solenoid valve that constitutes the valve body 60 described above, thereby adjusting the hydraulic pressure supplied to the forward clutch 28 and the reverse brake 29 to switch forward and backward, and supply it to the transfer clutch 41. The distribution ratio of the driving force transmitted to the rear wheels 10RL and 10RR is adjusted by adjusting the hydraulic pressure to be applied.

  Here, the TCU 50 is connected to a vehicle dynamic control unit (hereinafter referred to as “VDCU”) 70, an SBW-CU 80, and the like via a CAN (Controller Area Network) 100.

  Connected to the VDCU 70 are a brake switch 71 that detects whether or not the brake pedal is depressed, and a brake fluid pressure sensor 72 that detects the master cylinder pressure (brake hydraulic pressure) of the brake actuator 74. The brake switch 71 and the brake fluid pressure sensor 72 function as a brake operation detection unit described in the claims. In addition, a wheel speed sensor 73 that detects the rotational speed (vehicle speed) of each wheel of the vehicle is connected to the VDCU 70.

  The VDCU 70 drives the brake actuator 74 in accordance with the operation amount (depression amount) of the brake pedal to brake the vehicle, and various vehicle behaviors (for example, a wheel speed sensor 73, a steering angle sensor, an acceleration sensor, a yaw rate sensor, etc.) ), The brake control by the automatic pressurization and the torque control of the engine 20 suppress the side slip and ensure the vehicle stability at the time of turning.

  The VDCU 70 transmits the detected brake switch 71, braking information (brake operation information) such as brake fluid pressure, wheel speed (vehicle speed), and the like to the TCU 50 via the CAN 100. Note that the VDCU 70 automatically drives the brake actuator 74 to brake the vehicle when receiving automatic braking (automatic braking / pre-crash braking) request information from a driving support device having a pre-crash safety function, for example. To do. At that time, the VDCCU 70 also transmits such braking information (brake operation information) to the TCU 50 via the CAN 100. Therefore, the “brake operation state” described in the claims includes not only the depression of the brake pedal by the driver but also the operation state of automatic braking (automatic braking).

  The SBW-CU 80 generates and outputs a control signal (motor drive signal) based on various information including the shift range received from the TCU 50 via the CAN 100 and drives the SBW actuator 81. The SBW actuator 81 switches the shift range of the continuously variable transmission 30 by moving the manual valve of the continuously variable transmission 30 in accordance with a control signal from the SBW-CU 80. That is, the SBW-CU 80 and the SBW actuator 81 function as switching means described in the claims. Note that the SBW-CU 80 and the SBW actuator 81 may be configured integrally.

  Note that, when the P (parking) range is selected, the SBW-CU 80 may perform the parking lock after receiving the information indicating that the parking lock is permitted from the TCU 50. However, at that time, if a predetermined time (about several seconds) has elapsed after the P range is selected, it is preferable to perform parking lock regardless of the presence or absence of permission information.

  The TCU 50 is attached in the vicinity of the output shaft (secondary shaft 37) of the continuously variable transmission 30, and detects the rotational speed of an output shaft rotation sensor (vehicle speed sensor) 52 that detects the rotational speed of the output shaft, and the primary pulley 34. A primary pulley rotation sensor 53 is connected. In addition, a range switch 54 that detects a selection position of the shift lever 55 is connected to the TCU 50. Further, the TCU 50 receives information such as the brake information (brake operation information) such as the brake switch 71 and the brake fluid pressure, and the wheel speed (vehicle speed) described above via the CAN 100.

  The TCU 50 stores the stored contents by a microprocessor that performs calculations, a ROM that stores programs for causing the microprocessor to execute each process and a shift map, a RAM that stores various data such as calculation results, and a 12V battery. A backup RAM, an input / output I / F, and the like.

  The TCU 50 automatically shifts the gear ratio steplessly in accordance with the driving state of the vehicle (for example, accelerator pedal opening, vehicle speed, or engine speed) according to the shift map. The shift map is stored in the ROM in the TCU 50.

  The TCU 50 executes transfer clutch control (AWD control) based on various information acquired from the various sensors described above. Further, the TCU 50 has a function of controlling the hydraulic pressure of the transfer clutch 41 so as to reduce the rattling noise (abnormal noise) between the parking gear 114 and the parking pole 113 when the P (parking) range is selected (parking lock). Have. Therefore, the TCU 50 functionally includes the transfer clutch control unit 51. In the TCU 50, the function of the transfer clutch control unit 51 is realized by the program stored in the ROM being executed by the microprocessor.

  The transfer clutch control unit 51 determines in real time the fastening force of the transfer clutch 41 (that is, the driving force distribution ratio to the rear wheels 10RL, 10RR) based on the driving state of the vehicle (for example, the driving state of the four wheels, the engine torque, etc.). To control. That is, the transfer clutch control unit 51 functions as transfer clutch control means described in the claims.

  In particular, the transfer clutch control unit 51 transfers the transfer clutch when the brake pedal is depressed (the vehicle is being braked) and the vehicle speed is equal to or lower than a predetermined speed (for example, an extremely low vehicle speed just before stopping). 41 is released once. Then, the transfer clutch control unit 51 restarts the transfer clutch 41 when the speed of the vehicle becomes zero (when the vehicle is stopped) when the brake pedal is depressed (the vehicle is braked). Conclude.

  The transfer clutch control unit 51 once (temporarily) releases the transfer clutch 41 when the brake pedal is depressed (the vehicle is braked) and the vehicle speed becomes zero. You may make it fasten again.

  By such disengagement and re-engagement of the transfer clutch 41, the drive shafts (for example, the turbine shaft 31, the primary shaft 32, the secondary shaft 37, the counter shaft 39, which constitute a power transmission system between the torque converter 22 and the transfer clutch 41). , The front drive shaft 43, the left front wheel drive shaft 45L, and the right front wheel drive shaft 45R are twisted, and drive shafts that constitute a power transmission system between the transfer clutch 41 and the rear wheels 10RL, 10RR (for example, The propeller shaft 46, the left rear wheel drive shaft 48L, and the right rear wheel drive shaft 48R) are not twisted.

  Therefore, when the P (parking) range is subsequently selected and the parking gear 114 is locked, the shaft rigidity of the drive shaft that constitutes the power transmission system between the transfer clutch 41 and the rear wheels 10RL and 10RR is determined. The rotation of the parking gear 114 caused by releasing the forward clutch 28 and releasing the twist of the drive shaft between the torque converter 22 and the transfer clutch 41 is suppressed. As a result, rattling noise (abnormal noise) between the parking gear 114 and the parking pole 113 when the P (parking) range is selected is reduced.

  Note that when the shift position of the continuously variable transmission 30 is in the N (neutral) range, no driving force is applied to the drive shaft constituting the power transmission system, and the drive shaft does not twist. The clutch control unit 51 prohibits the release and re-engagement of the transfer clutch 41.

  In addition, the transfer clutch control unit 51 sends information indicating that the SBW-CU 80 is allowed to switch the shift range of the continuously variable transmission 30 to the P (parking) range after the transfer clutch 41 is re-engaged. You may make it transmit via.

  Next, the operation of the transfer clutch control device 1 will be described with reference to FIG. FIG. 3 is a flowchart showing a processing procedure of transfer clutch control (tooth rattling noise reduction control) by the transfer clutch control device 1. This process is mainly repeatedly executed at a predetermined timing in the TCU 50.

  In step S100, it is determined whether or not the shift range of the continuously variable transmission 30 is the D (drive) range or the R (reverse) range. Here, when the shift position is the D range or the R range, the process proceeds to step S102. On the other hand, when the shift position is not in the D range or R range, that is, in the N (neutral) range, the process is temporarily exited.

  In step S102, it is determined whether or not the brake pedal is depressed (braking) and the vehicle speed is equal to or lower than a predetermined value (for example, an extremely low vehicle speed immediately before stoppage or zero vehicle speed). If both conditions are satisfied, the process proceeds to step S104. On the other hand, when both the conditions are not satisfied, or when either one of the conditions is not satisfied, the process is temporarily exited.

  In step S104, the transfer clutch 41 is released. Thereafter, in step S106, a determination is made as to whether or not the vehicle speed is zero (whether or not the vehicle has been stopped by depressing the brake pedal). If the vehicle speed is zero, the process proceeds to step S108. On the other hand, when the vehicle speed is not zero, the process proceeds to step S104, and the processes of steps S104 and S106 are repeatedly executed until the vehicle speed becomes zero (until the vehicle stops).

  In step S108, the transfer clutch 41 is re-engaged. Thereby, the drive shaft (turbine shaft 31, primary shaft 32, secondary shaft 37, counter shaft 39, front drive shaft 43, left front wheel drive shaft 45L, which constitutes a power transmission system between the torque converter 22 and the transfer clutch 41, And the right front wheel drive shaft 45R) are twisted, and drive shafts (propeller shaft 46, left rear wheel drive shaft 48L, and right rear wheel) constituting a power transmission system between the transfer clutch 41 and the rear wheels 10RL and RR. The drive shaft 48R) is created with no twist.

  Thereafter, when the P (parking) range is selected, the parking gear 114 and the parking pole 113 are engaged and the parking gear 114 is locked (step S110).

  As described above in detail, according to the present embodiment, the speed of the vehicle is equal to or lower than a predetermined speed (for example, an extremely low vehicle speed immediately before stopping) in a state where the brake pedal is depressed (the vehicle is braked). In other words, when the brake pedal is depressed, the vehicle stops, and immediately before the drive shaft of the power transmission system can be twisted, the transfer clutch 41 is once released. After that, when the vehicle stops with the brake pedal depressed (while the vehicle is braked), the transfer clutch 41 is re-engaged. Therefore, by this series of operations, when the brake pedal is depressed and the vehicle stops, the drive shaft and the like that constitute the power transmission system between the torque converter 22 and the transfer clutch 41 are twisted. A state in which no torsion is generated is created in the drive shaft and the like constituting the power transmission system between the clutch 41 and the rear wheels 10RL and 10RR. Therefore, after that, when the P (parking) range is selected and the parking gear 114 is locked, the shaft rigidity of the drive shaft or the like constituting the power transmission system between the transfer clutch 41 and the rear wheels 10RL and 10RR is determined. The rotation of the parking gear 114 caused by releasing the forward clutch 28 and releasing the torsion of the drive shaft between the torque converter 22 and the transfer clutch 41 is suppressed. As a result, it is possible to reduce rattling noise (abnormal noise) between the parking gear 114 and the parking pole 113 when the P (parking) range is selected. In this case, since the transfer clutch 41 is once released before the vehicle is completely stopped, and the transfer clutch 41 is re-engaged when the vehicle stops, the driver selects the P range immediately after the vehicle stops. Even if it does, the rattling noise of the parking gear 114 and the parking pole 113 can be reduced.

  According to the present embodiment, when the vehicle stops with the brake pedal depressed (brake state), the transfer clutch 41 can be once released and then re-engaged. Even in this case, although the drive shaft and the like constituting the power transmission system between the torque converter 22 and the transfer clutch 41 are twisted, the power transmission between the transfer clutch 41 and the rear wheels 10RL and 10RR is performed. A state in which the drive shaft and the like constituting the system are not twisted is created. Therefore, when the P (parking) range is selected and the parking gear 114 is locked, the forward clutch 28 is released by the shaft rigidity of the power transmission system between the transfer clutch 41 and the rear wheels 10RL and 10RR. Thus, the rotation of the parking gear 114 caused by releasing the twist between the torque converter 22 and the transfer clutch 41 is suppressed. As a result, it is possible to reduce rattling noise between the parking gear 114 and the parking pole 113 when the P (parking) range is selected.

  According to this embodiment, when the shift range of the continuously variable transmission 30 is the N (neutral) range, the release and re-engagement of the transfer clutch 41 is prohibited. When the shift range of the continuously variable transmission 30 is the N (neutral) range, no drive force is applied to the drive shaft and the like constituting the power transmission system, and thus the drive shaft and the like are not twisted. Therefore, when the parking gear 114 is locked, the rattling noise between the parking gear 114 and the parking pole 113 does not occur. Therefore, in such a case, it is possible to prevent unnecessary operations from being performed by prohibiting the release and re-engagement of the transfer clutch 41.

  According to the present embodiment, when an operation for selecting the P (parking) range is accepted, the shift range of the continuously variable transmission 30 is set to the SBW-CU 80 after the transfer clutch 41 is re-engaged. It can also be controlled to permit switching to the P (parking) range. By doing so, the transfer clutch 41 is once released and then re-engaged, and then the shift range of the continuously variable transmission 30 is switched to the P (parking) range. Therefore, for example, even if the P (parking) range is selected at the same time as the vehicle stops or immediately before the vehicle stops, the rattling noise between the parking gear 114 and the parking pole 113 is reliably reduced. It becomes possible to do.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above embodiment, the present invention is applied to a chain type continuously variable transmission (CVT). However, instead of the chain type continuously variable transmission, for example, a belt type continuously variable transmission, a toroidal type It can also be applied to a continuously variable transmission or the like. Moreover, it can apply also to a stepped automatic transmission (AT) instead of a continuously variable transmission.

  In the above embodiment, a hydraulic clutch is used as the transfer clutch 41, but an electromagnetic solenoid clutch may be used.

  The above-described configuration of the driving force transmission system (for example, arrangement of gears, shafts, etc.) is an example, and is not limited to the above embodiment.

  Furthermore, in the above-described embodiment, the TCU 50, the VDCU 70, and the SBW-CU 80 are connected to each other by the CAN 100 so that they can communicate with each other. However, the system configuration is not limited to such a form. It can be arbitrarily changed in consideration of the above. In that case, in the said embodiment, although control of the transfer clutch 41 was performed by TCU50, it is good also as a structure controlled by the dedicated AWD controller independent of TCU50.

  In the above embodiment, the case where the present invention is applied to the SBW type continuously variable transmission 30 has been described as an example. However, the present invention may be applied to a wire type conventional continuously variable transmission.

  In the above-described embodiment, the case where the shift is mainly performed from the D (drive) range to the P (parking) range has been described as an example. However, when the shift is performed from the R (reverse) range to the P (parking) range, Similarly, by controlling the transfer clutch 41, it is possible to reduce rattling noise (abnormal noise) during parking lock.

DESCRIPTION OF SYMBOLS 1 Transfer clutch control apparatus 10FL Left front wheel 10FR Right front wheel 10RL Left rear wheel 10RR Right rear wheel 20 Engine 22 Torque converter 27 Forward / reverse switching mechanism 28 Forward clutch 29 Reverse brake 30 Continuously variable transmission 33 Transmission mechanism 41 Transfer clutch 50 TCU
51 Transfer Clutch Control Unit 52 Output Shaft Rotation Sensor 53 Primary Pulley Rotation Sensor 54 Range Switch 55 Shift Lever 60 Valve Body 70 VDCU
71 Brake switch 72 Brake fluid pressure sensor 73 Wheel speed sensor 74 Brake actuator 80 SBW-CU
81 SBW actuator 100 CAN
110 Parking mechanism 113 Parking pole 114 Parking gear

Claims (4)

In a control device for a transfer clutch of an all-wheel drive vehicle equipped with an automatic transmission having a parking mechanism that includes a parking gear and a parking pole and locks an output shaft,
Vehicle speed detection means for detecting the speed of the vehicle;
Brake operation detecting means for detecting an operation state of a brake for braking the vehicle;
A transfer clutch for adjusting a driving force transmitted from the speed change mechanism constituting the automatic transmission to the drive system on the driven wheel side;
Transfer clutch control means for controlling the fastening force of the transfer clutch based on the driving state of the vehicle,
The transfer clutch control means releases the transfer clutch when the brake is operated and the speed of the vehicle falls below a predetermined speed, and then the brake is operated and the speed of the vehicle becomes zero. In this case, the transfer clutch control device is configured to fasten the transfer clutch. The predetermined speed is zero;
2. The transfer according to claim 1, wherein the transfer clutch control means releases the transfer clutch once when the brake is operated and the speed of the vehicle becomes zero, and then re-engages the transfer clutch. Control device for clutch.   The transfer clutch control means according to claim 1 or 2, wherein the transfer clutch control means prohibits the release and re-engagement of the transfer clutch when the shift range of the automatic transmission is a neutral range. apparatus. A selector that receives an operation of selecting a shift range of the automatic transmission and outputs selection information corresponding to the operation;
Switching means for switching the shift range of the automatic transmission according to the selection information output by the selection means,
When the operation for selecting the parking range is accepted by the selection means, the transfer clutch control means sets the shift range of the automatic transmission to the switching range after the transfer clutch is re-engaged. The transfer clutch control device according to any one of claims 1 to 3, wherein the switching clutch is permitted.

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