JP2018004066A - Control device of power transmission device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a power transmission device for a vehicle which suppresses a loss of a drive force of a drive electric motor in the power transmission device for the vehicle which is transmitted to wheels, and suppresses noise which is generated when the backlash of a gear arranged in the power transmission device for the vehicle is clogged.SOLUTION: When a difference between a rotational speed Vm of an electric motor 18 and an average rotational speed Va of rear wheels 20L, 20R is larger than a backlash-clogging determination value Vc, that is, when the backlash of a gear arranged in a rear-wheel power transmission device 10b is clogged, a load A is imparted to a side gear 56R by driving a clutch member 60 by a second thrust force F2 which is larger than a first thrust force F1 for moving the clutch member 60 to an engagement position, a force by which the side gear 56R pre-pressurizes a pinion 58 is thereby raised, and differential preload torque Td is increased. By this constitution, noise which is generated when the gear arranged in the rear-wheel power transmission device 10b is clogged can be suitably suppressed.SELECTED DRAWING: Figure 7

Description

  The present invention provides a vehicle power transmission comprising a differential device that transmits a driving force of a driving motor to driving wheels, and a connection / disconnection clutch that connects / disconnects a power transmission path between the driving motor and a pinion of the differential device. The present invention relates to a technique for suitably suppressing an abnormal noise generated when a backlash of a gear provided in the vehicle power transmission device is clogged.

  There is known a vehicle power transmission device including a differential device that transmits a driving force of a driving motor to driving wheels, and a connection / disconnection clutch that connects / disconnects a power transmission path between the driving motor and a pinion of the differential device. ing. For example, the power transmission device for vehicles described in patent document 1 is it. For example, in the vehicle power transmission device of Patent Document 1, a rear driving differential device that transmits the driving force of the driving motor to the rear wheels, a speed reduction mechanism that transmits the driving force of the driving motor to the differential device, and A connection / disconnection clutch for connecting / disconnecting a power transmission path between the speed reduction mechanism and the pinion of the differential device is provided.

JP 2010-202190 A

  By the way, in the vehicle power transmission device as described above, in a state where the drive motor and the pinion of the differential device are connected by the connection / disconnection clutch, for example, by input from the drive wheel side, When the backlash of the gear provided in the vehicle power transmission device suddenly clogs and the impact of the clogging is transmitted to the input shaft of the driving motor, the input shaft moves in the thrust direction and the power for the vehicle A collision with the case of the transmission device, coupled with the relatively large mass of the rotor of the driving motor connected to the input shaft, causes a relatively large noise when the input shaft collides with the case. There was a problem that occurred.

  Further, in order to suppress abnormal noise when the input shaft collides with the case, the differential gear is preloaded to the pinion side to increase the differential preload torque, and the power transmission device has a relatively large backlash. It is conceivable that the backlash between the side gear and the pinion having the above is suitably reduced, but the drive motor transmitted to the drive wheels in the vehicle power transmission device by increasing the differential preload torque There is a problem that the loss of driving force increases.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to suppress the loss of the driving force of the driving motor transmitted to the driving wheels in the vehicle power transmission device, and Another object of the present invention is to provide a control device for a vehicle power transmission device that suppresses an abnormal noise that occurs when a backlash of a gear provided in the vehicle power transmission device is clogged.

  The gist of the first invention is that: (a) a differential case that houses a pair of side gears coupled to a pair of drive wheels and is driven to rotate around a rotation center line by a drive motor; and the differential case An annular pinion support member that is housed so as to be relatively rotatable about the rotation center line and rotatably supports a pinion that meshes with the pair of side gears via a pinion pin, and a relative rotation about the rotation center line on the differential case An engagement position provided so as to be impossible and movable in a direction parallel to the rotation center line, and meshing with the annular pinion support member by a clutch actuator to make the annular pinion support member relatively unrotatable and the annular pinion support The rotation of the annular pinion support member is released from engagement with the member. A control device for a vehicle power transmission device, comprising: a clutch member that is moved between a release position that allows relative rotation around a center line; and a return spring that biases the clutch member toward the release position. (B) To apply a load toward the pinion to the side gear when the clutch member is moved to the meshing position side against the biasing force of the return spring by the clutch actuator. (C) When driving the driving wheel by the driving motor, the clutch actuator is driven by the clutch actuator with a thrust that is large enough to reach the meshing position. When the difference between the rotational speed of the drive motor and the rotational speed of the drive wheel is greater than a predetermined value, the clutch Wood and by driving the clutch member at a greater thrust than the thrust that has moved to the engagement position is to impart a load to the side gears.

  According to the first invention, when the clutch member is moved to the meshing position side against the urging force of the return spring by the clutch actuator, a load toward the pinion is applied to the side gear. When the driving wheel is driven by the driving motor, the clutch actuator is driven by the clutch actuator with a thrust force that reaches the meshing position. When the difference between the rotational speed of the drive motor and the rotational speed of the drive wheel is greater than a predetermined value, the clutch member is driven with a thrust larger than the thrust that has moved the clutch member to the meshing position. A load is applied to the side gear. For this reason, when the difference between the rotational speed of the drive motor and the rotational speed of the drive wheel is larger than a predetermined value, that is, a state where the backlash of the gear provided in the vehicle power transmission device is packed. In this case, since the clutch member is driven with a thrust larger than the thrust that has moved the clutch member to the meshing position and a load is applied to the side gear, the force with which the side gear preloads the pinion is increased. The differential preload torque is increased. As a result, an abnormal noise that occurs when the backlash of the gear provided in the vehicle power transmission device is clogged is suitably suppressed. In addition, since the differential preload torque is temporarily increased only when the backlash of the gear provided in the vehicle power transmission device is packed, for example, the side gear always has a pinion to suppress the noise. The loss of the driving force of the driving motor transmitted to the driving wheels in the vehicle power transmission device can be suitably suppressed as compared with the one that increases the preload force and constantly increases the differential preload torque. it can.

1 is a skeleton diagram schematically illustrating a configuration of a four-wheel drive vehicle to which the present invention is preferably applied. It is a figure explaining the structure of the power transmission device for rear wheels provided in the four-wheel drive vehicle of FIG. FIG. 3 is a cross-sectional view illustrating a rear differential device, a connection / disconnection clutch, and a clutch actuator provided in the rear wheel power transmission device of FIG. 2. FIG. 4 is an enlarged view of FIG. 3, showing a state where the clutch member of the connection / disconnection clutch is moved to the meshing position by the clutch actuator. It is a functional block diagram explaining the principal part of the control function with which the electronic control apparatus provided in the four-wheel drive vehicle of FIG. 1 was equipped. 6 is a flowchart illustrating an example of a control operation of thrust control of thrust applied from an electromagnetic coil of a clutch actuator to a clutch member after switching from a two-wheel drive state to a four-wheel drive state in the electronic control device of FIG. 5. . It is a time chart at the time of performing the control action shown to the flowchart of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a skeleton diagram schematically illustrating a configuration of a four-wheel drive vehicle 12 provided with a power transmission device (vehicle power transmission device) 10 to which the present invention is preferably applied. In FIG. 1, a power transmission device 10 includes a front wheel power transmission device 10a (front transaxle) that transmits the driving force of the engine 14 to the front wheels 16L and 16R using an engine 12 as a drive source, and an electric motor (drive motor). A rear wheel power transmission device 10b (rear transaxle) that transmits the driving force of the electric motor 18 to the rear wheels (drive wheels) 20L and 20R using 18 (see FIG. 2) as a drive source is provided.

  As shown in FIG. 1, the front wheel power transmission device 10 a includes a front differential device 22 that transmits the driving force of the engine 14 to the front wheels 16 </ b> L and 16 </ b> R, and a power transmission path between the front differential device 22 and the engine 14. An automatic transmission 23 provided, and axles 24L and 24R provided in a power transmission path between the front differential device 22 and the rear wheels 16L and 16R are provided. In the front wheel power transmission device 10a, the driving force of the engine 14 is transmitted to the rear wheels 16L and 16R via the automatic transmission 23, the front differential device 22, the axles 24L and 24R, and the like.

  As shown in FIG. 2, the rear wheel power transmission device 10b includes a rear differential device 26 that transmits the driving force of the electric motor 18 to the rear wheels 20L and 20R, and a pinion 58 of the electric motor 18 and the rear differential device 26. A connecting / disconnecting clutch 28 for connecting / disconnecting the power transmission path between the motor, a counter shaft 30 provided in the power transmission path between the electric motor 18 and the rear differential device 26, a rear differential device 26, and the rear wheels 20L, 20R. And axles 32L and 32R provided in the power transmission path between the two. In the rear wheel power transmission device 10b, when the power transmission path between the electric motor 18 and the pinion 58 of the rear differential device 26 is connected by the connection / disconnection clutch 28, the driving force of the electric motor 18 is changed to the counter shaft 30, It is transmitted to the rear wheels 20L, 20R via the rear differential device 26, the axles 32L, 32R, and the like.

  In the two-wheel drive state of the four-wheel drive vehicle 12 configured as described above, the driving force transmitted from the engine 14 via the automatic transmission 23 is transmitted to the left and right through the front differential device 22 and the left and right axles 24L and 24R. It is transmitted to the front wheels 16L and 16R. In the two-wheel drive state, the power transmission path between the electric motor 18 and the pinion 58 of the rear differential device 26 is interrupted by the connection / disconnection clutch 28, and the driving force of the electric motor 18 is transmitted to the rear wheels 20L and 20R. It is gone. In the four-wheel drive state, in addition to the two-wheel drive state, the power transmission path between the electric motor 18 and the pinion 58 of the rear differential device 26 is connected by the connection / disconnection clutch 28, and the counter shaft The driving force transmitted through 30 is transmitted to the left and right rear wheels 20L and 20R through the rear differential device 26 and the left and right axles 32L and 32R.

  As shown in FIG. 2, the electric motor 18 includes a cylindrical stator 18a fixed in a container-like case 34, and a cylindrical input shaft 18b at the center with a predetermined gap inside the stator 18a. The rotor 18c is rotatably supported around a first rotation center line (rotation center line) C1 by a cylindrical rotor 18c fixed integrally therewith and a pair of first bearings 36, 38 provided in the case 34. An input shaft 18b is provided.

  As shown in FIG. 2, the counter shaft 30 is supported by a pair of second bearings 40 and 42 provided in the case 34 so as to be rotatable around a second rotation center line C2 parallel to the first rotation center line C1. The countershaft 30 is formed at the end of the countershaft 30 on the electric motor 18 side, and meshes with the meshing teeth 18d formed on the input shaft 18b. A small-diameter gear portion 30b is formed which has a smaller diameter than 30a and is formed at the end of the countershaft 30 opposite to the electric motor 18 side. The outer peripheral teeth of the large-diameter gear portion 30a, the engaging teeth 18d of the input shaft 18b meshing with the large-diameter gear portion 30a, the outer peripheral teeth of the small-diameter gear portion 30b, and the ring gear 50 described later that meshes with the small-diameter gear portion 30b are, for example, inclined teeth. is there.

  As shown in FIGS. 2 and 3, the rear differential device 26 houses a pair of side gears 56 </ b> L and 56 </ b> R connected to the pair of rear wheels 20 </ b> L and 20 </ b> R via axles 32 </ b> L and 32 </ b> R. A differential case 48 that is rotationally driven around one rotation center line C1, a pinion pin 54 that is supported at both ends by an annular pinion support member 52, which will be described later, and a pinion pin 54 that are opposed to each other. A pair of side gears 56L, 56R rotatably supported around the first rotation center line C1 by 48 and a pair of side gears 56L, 56R supported by the pinion pin 54 so as to be rotatable by passing through the pinion pin 54. And a pair of pinions 58 that respectively mesh with them. . A ring gear 50 that meshes with the small-diameter gear portion 30 b of the counter shaft 30 is integrally provided on the outer peripheral portion of the differential case 48. The differential case 48 is supported by a pair of third bearings 44 and 46 provided in the case 34 so as to be rotatable around the first rotation center line C1.

  2 and 3, the connection / disconnection clutch 28 is housed in a differential case 48 so as to be relatively rotatable about the first rotation center line C1, and a pinion 58 that meshes with a pair of side gears 56L, 56R is pinion pins. An annular pinion support member 52 that is rotatably supported via 54, and a differential case 48 that is relatively non-rotatable about the first rotation center line C1 and is movable in a direction parallel to the first rotation center line C1, A meshing position and a pinion support member that engage with the first meshing teeth 52a of the pinion support member 52 by a clutch actuator 62, which will be described later, so that the pinion support member 52 cannot rotate relative to the differential case 48 around the first rotation center line C1. 52 is released from meshing with the first meshing teeth 52 a of the pinion support member 52. File and the clutch member 60 is moved is provided between the release position for allowing the relative rotation of the first around the rotation center line C1 with respect Ren Shall case 48. A first meshing tooth 52 a is formed on the side surface of the pinion support member 52 on the clutch member 60 side, and a first meshing tooth 60 a is formed on the side surface of the clutch member 60 on the pinion support member 52 side. In addition, the clutch member 60 is moved to the pinion 58 side in the first rotation center line C1 direction by the clutch actuator 62 so that the first meshing teeth 60a of the clutch member 60 are engaged with the first meshing position of the pinion support member 52. The pinion support member 52, i.e., the pinion pin 54 rotates integrally with the differential case 48 around the first rotation center line C <b> 1 at the meshing position so that the electric motor 18 and the rear differential device 26 are engaged with each other. A power transmission path to and from the pinion 58 is connected. In the release position, the clutch member 60 is moved to the side opposite to the pinion 58 side in the first rotation center line C1 direction by the clutch actuator 62, and the first meshing teeth 60a of the clutch member 60 are moved to the pinion support member 52. The pinion support member 52, that is, the pinion pin 54 rotates relative to the differential case 48 around the first axis C <b> 1 at the release position, so that the electric motor 18 and the rear differential are not engaged with each other. The power transmission path between the device 26 and the pinion 58 is interrupted.

  As shown in FIG. 3, the clutch member 60 is disposed in the differential case 48 so as not to be relatively rotatable around the first rotation center line C1 and to be movable in a direction parallel to the first rotation center line C1. An annular annular portion 60b formed with meshing teeth 60a and a hole 48a formed in the differential case 48 through a portion of the annular portion 60b are inserted into the magnetic plunger 66 side of the clutch actuator 62 which is fixed in position. A protrusion 60c and an inward flange portion (load applying portion) 60d protruding from the annular portion 60b in a direction approaching the first rotation center line C1 are provided. When the clutch member 60 is moved to the meshing position by the clutch actuator 62, the inward flange portion 60d of the clutch member 60 comes into contact with the back surface 56a of the side gear 56R, and the load A toward the pinion 58 side (see FIG. 4) is given.

  The clutch actuator 62 drives the clutch member 60 with a thrust F (see FIG. 4) having a predetermined magnitude, and moves the clutch member 60 to the meshing position and the release position. As shown in FIG. 3, the clutch actuator 62 includes a cylindrical magnetic plunger 66 provided on a frame 64 fixed to the case 34 so as to be movable in a direction parallel to the first rotation center line C1, and its An electromagnetic coil 68 that applies thrust F to the magnetic plunger 66 and a disc spring (return spring) 70 that urges the clutch member 60 toward the release position are provided. The disc spring 70 is a disc-shaped plate member 72 fixed to the side surface 60e of the clutch member 60 on the electromagnetic coil 68 side, and the relative movement of the clutch member 60 in a direction parallel to the first rotation center line C1. Is disposed between the outer periphery of the clutch member 60 and the cylindrical spacer 74. The magnetic plunger 66 of the clutch actuator 62 includes a cylindrical cylindrical portion 76a disposed between the magnetic plunger 66 and the differential case 48, and an end portion of the cylindrical portion 76a on the clutch member 60 side. A sliding metal 76 having a flange 76b protruding in a direction away from the first rotation center line C1 is provided via a cylindrical non-magnetic plunger 77.

  In the clutch actuator 62 configured as described above, when the thrust F is applied to the magnetic plunger 66 by the electromagnetic coil 68 as shown in FIG. It is moved to the meshing position against the urging force of 70. When the thrust F is no longer applied from the electromagnetic coil 68 to the magnetic plunger 66, the clutch member 60 is moved to the release position by the elastic return force of the disc spring 70. Note that, when the thrust F is applied to the magnetic plunger 66 by the electromagnetic coil 68, the thrust F is applied to the clutch member 60 via the sliding metal 76, but the clutch member 60 is moved to the meshing position. Then, a load A toward the pinion 58 is applied to the side gear 56R by the inward flange portion 60d of the clutch member 60.

  FIG. 5 is a functional block diagram illustrating a main part of the control function provided in the electronic control device (control device) 78 provided in the four-wheel drive vehicle 12. As shown in FIG. 5, the electronic control unit 78 is supplied with various input signals detected by each sensor provided in the four-wheel drive vehicle 12. For example, a signal representing the rotational speed Vm (rpm) of the rotor 18c of the electric motor 18 detected by the motor rotational speed sensor 80, the rotational speeds Vl and Vr (rpm) of the rear wheels 20L and 20R detected by the wheel speed sensor 82 , And a signal indicating the position of the plate member 72 detected by the stroke sensor 84 (see FIG. 3), that is, the position of the clutch member 60 to which the plate member 72 is fixed, in the first rotation center line C1 direction. Is done.

  Various output signals are supplied from the electronic control device 78 to each device provided in the four-wheel drive vehicle 12. For example, a first current I1 supplied to the electromagnetic coil 68 of the clutch actuator 62 to engage the connection / disconnection clutch 28, and a second current I2 supplied to the electric motor 18 to drive the electric motor 18 are electronic It is supplied from the control device 78 to each part.

  The 4WD switching determination unit 90 shown in FIG. 5 starts from the two-wheel drive travel mode in which the two-wheel drive state in which the driving force is transmitted from the engine 14 to the left and right front wheels 16L and 16R is performed, and from the electric motor 18 to the left and right rear wheels 20L. , 20R is determined whether or not the four-wheel drive state in which the four-wheel drive state for transmitting the driving force is executed, that is, whether or not the rear wheels 20L and 20R are driven by the electric motor 18 is determined. For example, in the 4WD switching determination unit 90, the driving state of the four-wheel drive vehicle 12 is any one of four wheels of vehicle start-up travel, wheel slip, understeer, turning travel, acceleration travel, high-load travel, and deceleration travel. By satisfying the drive start condition, it is determined whether or not the two-wheel drive travel mode should be switched to the four-wheel drive travel mode.

  The thrust control unit 96 controls the first current I1 supplied to the electromagnetic coil 68 of the clutch actuator 62, whereby the thrust F (N (N) applied from the electromagnetic coil 68 to the clutch member 60 via the magnetic plunger 66. ) To control the size. The thrust control unit 96 is applied to the clutch member 60 from the electromagnetic coil 68 via the magnetic plunger 66 when it is determined by the 4WD switching determination unit 90 to switch from the two-wheel drive travel mode to the four-wheel drive travel mode. The magnitude of the thrust F is controlled so that the thrust F becomes the first thrust F1 having a preset magnitude. The first thrust F1 is a thrust that generates a load necessary to reach (move) the clutch member 60 to the meshing position against the biasing force of the disc spring 70. In the electronic control unit 78, for example, when the 4WD switching determination unit 90 determines that the two-wheel drive travel mode is switched to the four-wheel drive travel mode during the two-wheel drive travel, for example, the drive motor 18 causes the pinion support member 52 to The thrust F applied to the clutch member 60 from the electromagnetic coil 68 through the magnetic plunger 66 by the thrust controller 96 is synchronized with the rotational speed of the clutch member 60 so as to become the first thrust F1. The magnitude of thrust F is controlled.

  When the 4WD switching completion determining unit 90 determines that the 4WD switching determining unit 90 switches from the two-wheel drive travel mode to the four-wheel drive travel mode, the connection / disengagement clutch 28 causes the electric motor 18 and the pinion 58 of the rear differential device 26 to In other words, it is determined whether the clutch member 60 is moved to the meshing position by the clutch actuator 62 and switched from the two-wheel drive state to the four-wheel drive state. For example, in the 4WD switching completion determination 98, when the stroke sensor 86 detects that the clutch member 60 has moved to the meshing position, it is determined that the two-wheel driving state has been switched to the four-wheel driving state.

  The motor control unit 92 controls the second current I2 supplied to the electric motor 18 when the 4WD switching completion determination unit 98 determines that the two-wheel drive state has been switched to the four-wheel drive state, whereby the electric motor The driving force output from 18 to the rear wheels 20L and 20R is controlled. When the motor torque output determination unit 92a provided in the motor control unit 92 determines that the 4WD switching completion determination unit 98 has switched from the two-wheel drive state to the four-wheel drive state, the electric motor 18 changes to the rear wheel 20L. , 20R is determined based on whether the second current I2 is supplied to the electric motor 18, for example.

  The backlash determination unit 100 determines that the 4WD switching completion determination unit 98 has switched from the two-wheel drive state to the four-wheel drive state, and the motor torque output determination unit 92a changes from the electric motor 18 to the rear wheels 20L and 20R. If it is determined that the driving force is output, it is determined whether or not the backlash between the gears provided in the rear wheel power transmission device 10b is being stuffed. For example, in the backlash determination unit 100, a difference between the rotation speed Vm (rpm) of the electric motor 18 and the average rotation speed Va (rpm) of the rear wheels 20L and 20R is determined in advance. If it is greater than Vc (rpm), it is determined that the gears provided in the rear wheel power transmission device 10b are loosely packed. Since the electric motor 18 at the time of starting the four-wheel drive has been in a driven state until then, the electric motor 18 rotates at a speed exceeding the average rotational speed Va of the rear wheels 20L and 20R to close the backlash between the gears. The backlash determination value Vc is a value set experimentally in advance in order to determine such a state. The average rotation speed Va is an average ((Vl + Vr) / 2) of the rotation speed Vl (rpm) of the rear wheel 20L and the rotation speed Vr (rpm) of the rear wheel 20R.

  The thrust control unit 96 determines that the backlash between the gears provided in the rear wheel power transmission device 10b is not being backlashed by the backlash determination unit 100, and the electromagnetic plunger 68 to the magnetic plunger 66 are determined. The thrust F applied to the clutch member 60 via the first is the first thrust F1 that moves the clutch member 60 to the engagement position and generates a differential preload torque Td that is smaller than the abnormal noise countermeasure threshold L2 when loosening. However, if it is determined by the backlash determination unit 100 that backlash between the gears provided in the rear wheel power transmission device 10b is being closed, the clutch member is connected from the electromagnetic coil 68 via the magnetic plunger 66. The thrust F applied to 60 is controlled to increase to a second thrust F2 that is larger than the first thrust F1. The second thrust F2 is generated when the load A of the side gear 56R toward the pinion 58 by the inward flange portion 60d of the clutch member 60 is loosened in the gear provided in the rear wheel power transmission device 10b. A value set in advance to suppress abnormal noise, that is, the differential preload torque Td generated in the side gear 56R, is generated when the backlash of the gear provided in the rear wheel power transmission device 10b is reduced. This is the magnitude of the thrust F applied from the electromagnetic coil 68 to the clutch member 60 so as to be larger than the noise reduction threshold L2 that is set in advance so as to suitably suppress abnormal noise. The differential preload torque Td is a torque that the side gear 56R rotates with the differential case 48 as the differential case 48 rotates about the first rotation center line C1.

  6 shows the thrust F (N) applied from the electromagnetic coil 68 to the clutch member 60 after the electronic control device 78 is switched from the two-wheel drive state to the four-wheel drive state (time t1 in FIG. 7). It is a flowchart explaining an example of the action | operation of thrust control. FIG. 7 is a time chart when the control operation shown in the flowchart of FIG. 6 is executed. Note that the time chart of FIG. 7 is a diagram showing a state at the time of starting in a four-wheel drive state, for example.

  First, in step (hereinafter, step is omitted) S1 corresponding to the function of the motor torque output determination unit 92a, it is determined whether or not driving power is being output from the electric motor 18 to the rear wheels 20L and 20R. When the determination of S1 is negative, this routine is terminated, but when the determination of S1 is affirmative, S2 corresponding to the function of the looseness determination unit 100 is executed. In S2, whether or not the difference between the rotation speed Vm (rpm) of the electric motor 18 and the average rotation speed Va (rpm) of the rear wheels 20L and 20R is larger than the backlash determination value Vc (rpm), that is, the power for the rear wheels. It is determined whether or not the backlash between the gears provided in the transmission device 10b is being filled.

  When the determination in S2 is negative, the thrust F applied to the clutch member 60 from the electromagnetic coil 68 through the magnetic plunger 66 in S4 is set to the first thrust F1. However, when the determination of S2 is affirmative (time t2 in FIG. 7), S3 corresponding to the function of the thrust control unit 96 is executed. In S3, the thrust F applied to the clutch member 60 from the electromagnetic coil 68 via the magnetic plunger 66 is changed to a second thrust F2 that is larger than the first thrust F1 that has moved the clutch member 60 to the meshing position. Controlled to increase.

  At time t1 in the time chart of FIG. 7, for example, when an accelerator operation is performed at the start of the vehicle, switching from two-wheel drive to four-wheel drive and powering (torque output) of the electric motor 18 is started, the electromagnetic coil The thrust F applied to the clutch member 60 from 68 becomes the first thrust F1, and the connecting / disconnecting clutch 28 is engaged, and an increase in the vehicle speed is started. In this process, the rotational speed Vm of the electric motor 18 increases from the average rotational speed Va of the rear wheels 20L and 20R, and the backlash between the gears provided in the rear wheel power transmission device 10b in S2 of FIG. If it is determined that the stuffing is in progress, the thrust F applied from the electromagnetic coil 68 to the clutch member 60 is increased so as to be a second thrust F2 that is larger than the first thrust F1, thereby the differential preload torque Td. Will increase. Thus, when it is determined that the backlash between the gears is finished at time t3, the thrust F is returned from the second thrust F2 to the first thrust F1, and the differential preload torque Td is, for example, a one-dot chain line L1 in FIG. As shown, the thrust F applied to the clutch member 60 from the electromagnetic coil 68 remains the first thrust F1 even in a state in which the backlash of the gear provided in the rear wheel power transmission device 10b is packed. Compared with a motor that does not increase the torque Td, an abnormal noise that is generated when the backlash of the gear provided in the rear wheel power transmission device 10b is clogged is suitably suppressed. Further, as shown in FIG. 7, the thrust F applied from the electromagnetic coil 68 to the clutch member 60 is increased so as to become the second thrust F2, that is, the differential preload torque Td is increased later. This is only when the gear provided in the wheel power transmission device 10b is being loosened. For this reason, for example, as shown by a two-dot chain line representing the noise countermeasure threshold L2 in FIG. 7, in order to suppress the noise, the side gear always increases the force that preloads the pinion and constantly increases the differential preload torque Td. Compared to the above, the loss of the driving force of the electric motor 18 transmitted to the rear wheels 20L, 20R in the rear wheel power transmission device 10b can be suitably suppressed.

  As described above, according to the electronic control unit 78 of the power transmission device 10 of the present embodiment, the clutch member 60 is moved to the meshing position side by the clutch actuator 62 against the urging force of the disc spring 70. When the rear wheels 20L and 20R are driven by the electric motor 18, the clutch gear 62 causes the clutch to move to the side gear 56R when an inward flange portion 60d for applying a load A toward the pinion 58 is provided. When the member 60 is driven with the first thrust F1 having a magnitude that reaches the meshing position, and the difference between the rotational speed Vm of the electric motor 18 and the average rotational speed Va of the rear wheels 20L and 20R is larger than the backlash determination value Vc. The clutch member 60 is driven by the second thrust F2 that is larger than the first thrust F1 that has moved the clutch member 60 to the meshing position. To the load A applied to the side gears 56R is. Therefore, when the difference between the rotational speed Vm of the electric motor 18 and the average rotational speed Va of the rear wheels 20L and 20R is larger than the backlash determination value Vc, that is, a gear provided in the rear wheel power transmission device 10b. In this case, the clutch member 60 is driven by the second thrust F2 that is larger than the first thrust F1 that has moved the clutch member 60 to the meshing position, and the load A is applied to the side gear 56R. Therefore, the force with which the side gear 56R preloads the pinion 58 is increased, and the differential preload torque Td is increased. As a result, an abnormal noise that occurs when the backlash of the gear provided in the rear wheel power transmission device 10b is clogged is suitably suppressed. In addition, since the differential preload torque Td is temporarily increased only when the backlash of the gear provided in the rear wheel power transmission device 10b is packed, for example, in order to suppress the noise, the side gear is always used. Compared to the one that increases the preload force of the pinion and constantly increases the differential preload torque, the loss of the driving force of the electric motor 18 transmitted to the rear wheels 20L and 20R in the rear wheel power transmission device 10b is preferably Can be suppressed.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the clutch actuator 62 of the above-described embodiment, the thrust F is applied to the clutch member 60 by the electromagnetic coil 68. For example, instead of the electromagnetic coil 68, a pneumatic cylinder, a hydraulic cylinder, a motor actuator, or the like is used. May be. That is, any device may be used as long as it applies a thrust F to the clutch member 60.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

10: Power transmission device (vehicle power transmission device)
18: Electric motor (drive motor)
20L, 20R: Rear wheels (drive wheels)
48: Differential case 52: Pinion support member 54: Pinion pins 56L, 56R: Side gear 58: Pinion 60: Clutch member 60d: Inward flange portion (load applying portion)
62: Clutch actuator 70: Belleville spring (return spring)
78: Electronic control device (control device)
92a: Motor torque output determination unit 96: Thrust control unit 98: 4WD switching completion determination unit 100: Jittering determination unit A: Load C1: First rotation center line (rotation center line)
F: Thrust Vc: Backlash determination value (predetermined value)

Claims (1)

A pair of side gears connected to a pair of drive wheels, a differential case that is driven to rotate around a rotation center line by a drive motor; and a differential case that is rotatably accommodated around the rotation center line in the differential case; An annular pinion support member that rotatably supports a pinion that meshes with the pair of side gears via a pinion pin, and the differential case cannot be relatively rotated about the rotation center line and can move in a direction parallel to the rotation center line. The annular pinion support member is released from the engagement between the meshing position of the annular pinion support member and the annular pinion support member which is engaged with the annular pinion support member and makes the annular pinion support member relatively unrotatable by the clutch actuator. A solution that allows relative rotation of the member around the center of rotation. A clutch member to be moved between a position, the vehicle power transmission device including a return spring which urges said clutch member to said release position, and a control device,
The clutch member includes a load applying portion for applying a load toward the pinion to the side gear when the clutch member is moved to the meshing position side against the urging force of the return spring by the clutch actuator. And
When driving the drive wheels by the drive motor, the clutch actuator is used to drive the clutch member with a thrust that is large enough to reach the meshing position, and the rotational speed of the drive motor and the drive wheels When the difference from the rotational speed is larger than a predetermined value, the clutch member is driven with a thrust larger than the thrust that has moved the clutch member to the meshing position, and a load is applied to the side gear. A control device for a vehicle power transmission device.

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