JP2023005065A - Control device of transmission for vehicle - Google Patents

Abstract

To engage a dog clutch by easily eliminating so-called top face stop of the dog clutch even in a state of releasing an input clutch.SOLUTION: When driving-side dog teeth and driven-side dog teeth are axially relatively moved to be engaged with each other in a state of releasing an input clutch, a control device of a transmission for a vehicle starts control to engage the driving-side dog teeth and the driven-side dog teeth (step S2), and then, performs detection of a state of the driving-side dog teeth and the driven-side dog teeth in contact with each other not to be engaged with each other (step S3), and if not detecting completion of the engagement, changes torque of the driven-side dog teeth by a separate shaft drive mechanism for changing the torque of the driven-side dog teeth (step S6).SELECTED DRAWING: Figure 3

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling gear shifting in a transmission mounted on a vehicle, and more particularly to a device capable of selectively interrupting transmission of torque from a driving force source to the transmission and engaging or disengaging a dog clutch. The present invention relates to a control device for a transmission configured to set gears.

Patent Document 1 describes a control device for a transmission having a dog clutch. A dog clutch is an engagement mechanism configured to transmit torque by meshing dog teeth arranged in a circumferential direction, and configured to engage or disengage by moving the dog teeth in the direction of the rotation axis. It is Therefore, when the dog teeth are brought closer to each other so as to mesh with each other, if the phases of the dog teeth are the same, the top surfaces (tips) of the dog teeth will collide with each other and the dog teeth will be meshed. can't In the device described in Patent Literature 1, in order to eliminate such inconvenience when the dog clutch is engaged, the dog teeth are moved by a motor provided on the input side of the dog clutch or a motor as a driving force source. is configured to cause a difference in the phases of For example, when the top surfaces of the dog teeth collide with each other and the dog clutch is not engaged, the torque of the motor provided on the input side is changed to shift the phases of the dog teeth.

Further, since torque is transmitted in the dog clutch by the tooth flanks of the dog teeth that are in mesh with each other, a large surface pressure is applied to each tooth flank if the dog teeth are in mesh. Therefore, when the dog teeth are moved in the axial direction to release the dog clutch, if the surface pressure on the tooth flanks is high, the frictional force on the tooth flanks is large, and the dog clutch may not be released. In the device described in Patent Document 2, when the dog teeth are strongly meshed with each other and cannot be disengaged from each other, the contact pressure (surface pressure) between the dog teeth is reduced to reduce the contact pressure between the dog teeth. I'm trying to get out of engagement. Specifically, when the device described in Patent Document 2 turns off the motor and releases the dog clutch, if the release of the dog clutch is not detected, torque generated by the motor provided on the input side of the dog clutch is is applied to the dog clutch to reduce the frictional force on the tooth surface.

JP 2020-104671 A JP-A-11-91389

In the device described in Patent Document 1, when the dog clutch cannot be engaged because the top surfaces of the dog teeth are in contact with each other when engaging the dog clutch, a motor provided on the input side of the dog clutch engages the dog clutch. The teeth are out of phase with each other. Further, in the device described in Patent Document 2, when the dog clutch cannot be released due to a large contact pressure or frictional force between the dog teeth, a motor provided on the input side of the dog clutch disengages the dog teeth. It reduces the frictional force between Thus, conventionally, the torque of the motor provided on the input side of the dog clutch is used to change the phase between the dog teeth or reduce the frictional force when engaging or disengaging the dog clutch. are doing. On the other hand, vehicles equipped with a transmission are equipped with a clutch that can selectively cut off torque on the input side of the transmission, depending on the structure of the transmission. There are also vehicles configured to perform In this type of vehicle, when the gear ratio is changed by engaging the dog clutch (when shifting gears), the top surfaces of the dog teeth of the dog clutch that is about to be engaged for gear shifting collide with each other to engage the dog clutch. Even if the dog clutch cannot be released due to a situation where it cannot be engaged or the friction force between the dog teeth is large, the clutch will not be released and torque will not be transmitted to the transmission. However, it is not possible to change the phase of the dog teeth or the frictional force at the point of contact, and eventually, it may not be possible to easily resolve the above-mentioned state of being unable to engage or disengage.

The present invention has been made in view of the above-mentioned technical problems, and provides a state of disengagement due to abutment of the so-called top surface of a dog clutch incorporated in the transmission on the input side of the transmission. It is an object of the present invention to provide a control device capable of easily disengaging and engaging a dog clutch even when a clutch that is engaged is disengaged.

In order to achieve the above objects, a transmission that engages a dog clutch to set a predetermined gear stage is connected to a driving force source via an input clutch that selectively transmits and interrupts torque. The dog clutch has drive-side dog teeth to which torque is transmitted via the input clutch, and driven-side dog teeth that mesh with the drive-side dog teeth to transmit torque. In the control device for a vehicle transmission, the driven side dog teeth are relatively moved in the rotation center axis direction to engage the driving side dog teeth and the driven side dog teeth, wherein the driven side dog teeth are It further comprises a separate shaft drive mechanism that changes torque of the side dog teeth, and a controller that controls torque generated by the separate shaft drive mechanism, wherein the controller controls the driving side dog teeth and the driven side dog teeth in a state in which the input clutch is released. When the side dog teeth are moved relative to each other in the axial direction for engagement, after starting the control for engaging the driving side dog teeth and the driven side dog teeth, the driving side dog teeth and the driven side dog teeth are engaged. It is characterized in that it is detected that the dog tooth abuts and does not engage, and if the engagement is not detected, the torque of the driven side dog tooth is changed by the separate shaft drive mechanism.

In the present invention, when control is performed to engage the dog clutch in a state in which the input clutch is released and torque from the driving force source cannot be input to the transmission, the dog teeth on the driving side and the dog teeth on the driven side come into contact with each other. When a disengaged state occurs, the separate shaft drive mechanism changes the torque of the dog teeth on the driven side. In this case, the drive-side dog teeth are in contact with the driven-side dog teeth, so that the drive-side dog teeth tend to rotate together with the driven-side dog teeth. On the other hand, even if the drive side dog tooth is disconnected from the driving force source by disengaging the input clutch and the torque of the driving force source does not act, torque due to inertia torque and friction will be applied to the driving side dog tooth. Therefore, when the torque of the driven side dog teeth changes, relative rotation occurs between the driven side dog teeth and the driving side dog teeth, and as a result, the phases of the driven side dog teeth and the driving side dog teeth deviation occurs. That is, since contact between the top surfaces of the driven side dog teeth and the drive side dog teeth is eliminated, even when the driven side dog teeth and the drive side dog teeth are engaged and the input clutch is released, It is possible to easily engage the dog clutch by eliminating the so-called abutment of the top surfaces of the dog teeth.

1 is a block diagram schematically showing an example of a vehicle to which the present invention can be applied; FIG. It is a figure which shows an example of the dog clutch typically. 4 is a flowchart for explaining an example of control executed in an embodiment of the present invention; FIG. 5 is a schematic time chart for explaining changes when control is performed to eliminate top surface stoppage by torque of another shaft; FIG. FIG. 5 is a schematic time chart for explaining changes when control is performed to eliminate top surface stoppage by torque on the input side; FIG.

Next, a specific example of carrying out the present invention will be described. It should be noted that the specific example described below is merely an example of the present invention, and does not limit the present invention.

First, a vehicle to which the present invention can be applied is schematically shown in FIG. The vehicle shown here is a hybrid vehicle (electric vehicle) that uses an internal combustion engine and a motor (or motor generator) as driving force sources. It is mounted toward the rear of the vehicle, and a first motor (MG1) 2 having a power generation function is connected to its output side. Furthermore, a transmission (T/M) 4 is connected to the output side of the first motor 2 via an input clutch 3 .

The input clutch 3 is a clutch that selectively cuts off torque transmission between the transmission 4 and a so-called main driving force source consisting of the engine 1 and the first motor 2, and is, for example, a friction clutch. The transmission 4 is a transmission mechanism that appropriately sets the rotation speed ratio (gear ratio) between the input shaft 5 and the output shaft 6, and is a torque transmission path composed of a plurality of gear trains (not shown). are switched according to the engagement/disengagement states of a plurality of dog clutches to set a predetermined gear ratio. The transmission 4 may be a vehicle transmission having a conventionally known configuration.

A dog clutch is an engagement mechanism that transmits torque by meshing dog teeth. and spline teeth are formed on the outer peripheral portions of the driving side member and the driven side member that are adjacently arranged on the same rotation center axis line, and are engaged with those spline teeth. A sleeve having spline teeth (that is, dog teeth) formed on the inner peripheral surface is provided movably in the rotation center axis direction, and the sleeve connects the drive-side member and the driven-side member so as to be integrated in the rotation direction. configuration clutch. An example of the former dog clutch 7 is schematically shown in FIG. A driving side dog tooth 10 and a driven side dog tooth 11) are provided. The driving side member 8 is configured to transmit torque from, for example, the input shaft 5 described above, and the driven side member 9 is configured to transmit torque to the output shaft 6 described above. Further, one of the driving side member 8 and the driven side member 9 (for example, the driven side member 9) is configured to move back and forth in the direction of the rotation center axis to approach or separate from the other. The shift fork 12 is engaged with the member (for example, the driven side member 9).

An output shaft 6 of the transmission 4 is connected to a differential gear 13 which is a final reduction gear, and is configured to transmit driving force from the differential gear 13 to left and right rear wheels 14 .

On the other hand, a second motor (MG2) 15 corresponding to the separate shaft drive mechanism in the embodiment of the invention is provided. The second motor 15 is a motor (that is, a motor/generator) having a power generation function like the first motor 2 described above, and is configured to output driving force to the left and right front wheels 17 via a differential gear 16. It is Each of the motors 2 and 15 is connected to a power storage device (BATT) 18, and operates as a motor using the power of the power storage device 18 to output torque, or is driven by an external force to generate power, which is then stored as power. It is configured to charge the device 18 .

An electronic control unit (ECU) 19 is provided for controlling the engine 1, the motors 2 and 15, the input clutch 3 and the transmission 4 (especially the dog clutch 7). The electronic control unit 19 is mainly composed of a microcomputer, performs calculations using signals (data) input from various sensors (not shown) and pre-stored data, and controls the results of the calculations. It is configured to output as a command signal. Examples of data input from the sensor include a stroke signal corresponding to engagement/disengagement of the dog clutch 7 or a dog tooth position signal corresponding to the stroke amount, the rotation speed of the input shaft 5, the rotation speed of the output shaft 6, These include the remaining charge (SOC) of the power storage device 18, the temperature of the power storage device 18, the vehicle speed, the accelerator opening corresponding to the required driving force, and the like. The control command signals to be output are engagement/disengagement of the dog clutch 7, engagement/disengagement of the input clutch 3, start/stop and torque (positive torque and negative torque) of the motors 2 and 15, and gear shift instructions. .

The gear ratio set by the transmission 4 described above is determined mainly based on the vehicle speed, accelerator opening, and a pre-stored gear shift map, and gear shift control is executed to achieve the gear ratio. The gear shift is executed by disengaging one of a plurality of dog clutches and engaging any other dog clutch. In order to disconnect, the input clutch 3 is released. When any one of the dog clutches is to be engaged, in the example described here, the driven side member 9 (driven side dog tooth 11) is stroked toward the drive side member 8 (drive side dog tooth 10). When the positions (that is, phases) of the teeth 10 and 11 in the rotational direction match or substantially match, the tip surfaces (top surfaces) of the dog teeth 10 and 11 collide with each other, and the driven side member 9 cannot move any further. Do not stroke. In other words, a so-called top surface stop occurs, and a state in which the dog clutch 7 is not engaged occurs. In this state, the input clutch 3 is disengaged and no torque is applied to the driving side member 8 from the input side, so the driving side member 8 rotates together with the driven side member 9, and engagement does not progress as it is. . The control device according to the embodiment of the present invention is configured to execute the control shown in FIG. 3 in order to eliminate such a so-called top stop state and engage the dog clutch.

FIG. 3 is a flowchart for explaining an example of the control, which is executed by the electronic control unit 19 described above, and therefore the electronic control unit 19 corresponds to the controller in the embodiment of the present invention. The routine shown in FIG. 3 is executed in a state in which it is determined that the gear ratio should be changed, and the input clutch 3 is released accordingly. Specifically, it is determined whether or not the determination to issue a gear shift instruction has been established (whether ON), that is, whether or not the determination of gear shift has been established (step S1). If the determination in step S1 is negative, the routine of FIG. 3 is terminated without performing any particular control. Conversely, if the determination is affirmative, an instruction to execute a gear change (that is, an instruction to change gears) is issued (step S2). This is an instruction for control to release the dog clutch that sets the current gear stage and to engage the dog clutch for setting the gear stage after the gear shift.

As described above, the dog clutch is engaged by stroking one dog tooth toward the other dog tooth and meshing the two. In this case, if the phases of the dog teeth match or substantially match, the so-called abutment between the top surfaces prevents engagement. In step S3, it is determined whether or not such a state in which the top surfaces abut and do not engage, ie, a top surface stop occurs. This determination can be made based on a signal from a sensor that detects the stroke amount of the dog clutch. Specifically, it may be determined whether or not the detected value is insufficient for the stroke amount required for engagement of the dog clutch, or whether or not the stroke amount is the top surface stop stroke amount.

If the determination in step S3 is negative, that is, if the dog clutch is engaged, the routine of FIG. 3 is terminated without performing any particular control. Conversely, if the determination in step S3 is affirmative, it is determined whether or not the vehicle is running (step S4). This determination can be made based on the detected vehicle speed, or based on the selected shift range and vehicle speed.

If the result of step S4 is affirmative because the vehicle is running, it is determined whether or not another axle can be used (step S5). Here, the use of the separate shaft means using the torque of the second motor 15 as the separate shaft drive mechanism shown in FIG. The second motor 15 is supplied with electric power from the power storage device 18 and functions as a motor to output torque. The power storage device 18 is charged with the generated power. Therefore, when the discharge power from the power storage device 18 is limited by the remaining charge (SOC), the temperature, or the like, or when the charging power is limited, the positive or negative torque is generated by the second motor 15. Output may not be possible. In step S5, it is determined that there is no such restriction on the second motor 15.

If the determination in step S5 is affirmative, a torque for applying differential rotation is output from another shaft (step S6). This control is control to change the torque (positive torque or negative torque) of the second motor 15 . 1 can independently drive the rear wheels 14 and the front wheels 17. When the transmission 4 is used to shift gears, the input clutch 3 is released, so that the driving force of the rear wheels 14 is reduced. descend. On the other hand, by increasing the driving force of the front wheels 17 by the second motor 15, the driving force of the vehicle as a whole is ensured before and after the shift. Therefore, if the output torque of the second motor 15 is increased or decreased, the vehicle is accelerated or decelerated and the torque applied to the rear wheels 14 is changed. changes, and its rpm changes. When the dog clutch is stopped at the top surface, for example, the driving side member 8 and the driven side member 9 shown in FIG. In this state, when the rotational speed of the driven member 9 changes due to changes in the torque of the driven member 9 , torque corresponding to the rotational acceleration and moment of inertia is generated between the driven member 9 and the driving member 8 . If the torque generated in this manner is greater than the frictional force between the drive-side member 8 and the driven-side member 9, slippage will occur between the drive-side member 8 and the driven-side member 9, changing their phases. do. Such a phase shift between the driving side member 8 and the driven side member 9 is the differential rotation, and in step S6, a torque that causes such a differential rotation is output.

Next, it is determined whether or not a predetermined time has elapsed (whether or not a timeout has occurred) (step S7). Here, the predetermined time is a time determined by design as a length longer than the time normally required for the differential rotation to occur and shorter than the allowable time for shifting. Therefore, immediately after the torque is output from the other shaft in step S6, or when the timeout has not occurred, a negative determination is made in step S7. In that case, the process returns to step S3 to determine whether or not the top surface is stopped.

If the top stop has not been resolved because the torque has just been output from the other shaft or because the torque of the other shaft has not yet increased sufficiently, a positive determination is made in step S3. In that case, the control from step S4 to step S7 is repeated. In this case, if the predetermined time has not yet passed, the process returns to step S3 to determine whether or not the top surface is stopped. After the torque is output from another shaft, if the torque becomes sufficiently large or the amount of differential rotation becomes an amount that deviates from the top surface stop, the top surface stop is canceled and the dog clutch is engaged, so in step S3. judged negatively. In that case, the routine shown in FIG. 3 is once terminated. That is, gear shifting is completed.

On the other hand, if the predetermined time elapses without resolving the top surface stoppage (timeout), affirmative determination is made in step S7. In this case, even if the torque of another shaft is output, the top surface stop cannot be eliminated, that is, the dog clutch cannot be engaged, so another engagement control is executed. The engagement control in this case is control using torque from the input side, so first, the dog clutch is returned to neutral (step S8). This is to cut off torque transmission in the transmission 4 so that the driving force of the vehicle does not change due to the torque from the input side. Then, the input clutch 3 is re-engaged (step S9). This is for rotating the driving side member 8 of the dog clutch to be engaged.

After the input clutch 3 is re-engaged, it is determined whether or not the differential rotation has reached or exceeded a predetermined value (step S10). This determination can be made based on the number of revolutions of the input shaft 5 and the number of revolutions of the output shaft 6 . The input clutch 3 is engaged until an affirmative determination is made in step S10, that is, until a relative phase shift occurs between the driving-side dog teeth 10 and the driven-side dog teeth 11 . After that, the input clutch 3 is released (step S11).

In this manner, the relative phase between the driving side dog tooth 10 and the driven side dog tooth 11 in the dog clutch that has been stopped at the top surface is shifted, and then the process returns to step S2 to execute the shift again. After the control of steps S8 to S11 is performed, a relative phase shift occurs between the driving side dog tooth 10 and the driven side dog tooth 11, and the top surfaces thereof face each other in the direction of the rotation axis. has been eliminated, the dog clutch is engaged by performing gear shifting (gear change) again. That is, affirmative determination is made in step S3.

If the vehicle is stopped and the determination in step S4 is negative, the process immediately proceeds to step S8 to execute engagement control using torque on the input side. Similarly, if the second motor 15 cannot be sufficiently controlled and the determination in step S5 is negative, the process immediately proceeds to step S8 to execute engagement control using torque on the input side. .

The position (stroke) and rotation of the dog teeth when the dog clutch is engaged by performing the control up to step S7, that is, when the torque of another shaft is used to cancel the top surface stop and the dog clutch is engaged FIG. 4 shows an example of changes in the number and the torque of another axis. The example shown here is an example of an upshift. When the shift from Lo (low gear) to Hi (high gear) starts (at time t1), gear change starts, so the input shaft 5 decreases toward the synchronous rotation speed on the Hi side at a predetermined decreasing gradient. Along with this, the dog teeth begin to stroke toward the engagement position. When the top surfaces of the dog teeth come into contact with each other (time t2), the input clutch 3 is released and the input shaft 5 and the drive side member 8 connected thereto are dragged by the driven side member 9 and rotated. Therefore, the input shaft rotation speed becomes the Hi synchronous rotation speed.

When the dog teeth do not stroke to the engagement position, the determination of the top surface stop is established (time t3), and accordingly the torque of the other shaft (the torque of the second motor 15 in the above example) causes the differential rotation described above. The torque produced can be varied. In the example shown in FIG. 4, the torque is reduced. Therefore, each synchronous rotation speed (Hi synchronous rotation speed and Lo synchronous rotation speed), which is the rotation speed of the output shaft 6, decreases as the torque of the other shaft decreases. On the other hand, since the input shaft 5 and the drive-side member 8 connected thereto try to maintain the previous number of rotations due to their moment of inertia, the number of rotations is maintained at about the previous Hi synchronous number of rotations. .

In this manner, relative rotation (differential rotation) occurs between the dog teeth on the drive side and the driven side in the dog clutch to be engaged. are out of phase with each other, and these dog teeth 10 and 11 mesh with each other. That is, the dog clutch is engaged (time t4). Then, the input shaft rotation speed becomes the Hi synchronous rotation speed that has decreased as the torque of the other shaft decreases (time t5).

In addition, because the vehicle is stopped, or because it is not possible to engage with the torque of another shaft, control ( FIG. 5 shows an example of changes in the position (stroke) of the dog teeth, the rotational speed, and the engagement/disengagement of the input clutch 3 when the control of steps S8 to S11 described above is performed. The example shown in FIG. 5 is an example of an upshift, in which shifting from the Lo gear to the Hi gear is started (time t11), and as a result of this control, a top surface stop occurs (time t12). Judgment of surface stop is established (time t13). As a result of this determination, the dog clutch is returned to neutral (N) (time t14), and then the input clutch 3 is re-engaged (time t15).

Since the input clutch 3 is a friction clutch, when its transmission torque capacity gradually increases to a predetermined value, the input shaft rotation speed increases toward the Lo synchronous rotation speed before the shift start. As the input shaft rotation speed increases to the Lo synchronous rotation speed (time t16), the input clutch 3 is disengaged, and its transmission torque capacity gradually decreases. As the input clutch 3 is almost completely released, the input shaft rotation speed gradually decreases toward the Hi synchronization rotation speed. Until then, the dog clutch is maintained in neutral, and with the input clutch 3 almost completely disengaged and the input shaft rotation speed sufficiently reduced, the speed change control involving the gear change is executed again (at t17). point in time). As described above, in this case, since the top surfaces of the dog teeth are out of phase with each other, the dog clutch is engaged (at time t18) and the shift is completed.

In the control examples shown in FIGS. 4 and 5 described above, the rotation speed of the driven side member and the rotation speed of the drive side member in the dog clutch are changed by a separate shaft drive mechanism, an input side motor, etc., and the phase changes accordingly. Although this is an example in which the top surface stopping state is resolved by change, the relative phase of the dog teeth that should be meshed with each other may be changed by a change in the number of revolutions due to friction or the like. For example, the dog clutch (or the transmission 4) is brought into the neutral state while the input clutch 3 is released. In this way, the input shaft 5 and the driving side member 8 connected thereto are cut off from the driving force source such as the motor and the driving wheels, and are in a so-called free state. In this case, since the inevitable frictional force due to the bearings, lubricating oil, etc. acts, the rotational speed of the free-state input shaft 5 and the drive-side member 8 decreases due to the frictional force. Such a change in the number of revolutions may cause a relative phase shift between the driving-side dog tooth 10 and the driven-side dog tooth 11 to eliminate the so-called top stop state.

1 engine 2 motor 3 input clutch 4 transmission 5 input shaft 6 output shaft 7 dog clutch 8 drive side member 9 driven side member 10 drive side dog tooth 11 driven side dog tooth 12 shift fork 14 rear wheel 15 motor 17 front wheel 19 electronic control device

Claims (1)

A transmission that engages a dog clutch to set a predetermined gear stage is connected to a driving force source via an input clutch that selectively transmits and interrupts torque, and the dog clutch receives torque via the input clutch. and driven-side dog teeth that mesh with the drive-side dog teeth to transmit torque, and the drive-side dog teeth and the driven-side dog teeth are arranged relative to each other in the direction of the rotation axis. A control device for a vehicle transmission configured to engage the driving side dog teeth and the driven side dog teeth by moving the
a separate shaft drive mechanism that changes the torque of the driven side dog teeth;
further comprising a controller that controls the torque generated by the separate axis drive mechanism,
The controller is
When the drive-side dog teeth and the driven-side dog teeth are relatively moved in the axial direction and engaged with the input clutch released,
detecting that the drive-side dog tooth and the driven-side dog tooth are in contact with each other and do not engage after starting control for engaging the drive-side dog tooth and the driven-side dog tooth,
A control device for a vehicular transmission, wherein when the engagement is not detected, the torque of the driven side dog tooth is changed by the separate shaft drive mechanism.

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