Vehicle transmission control device

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

[Technical field]

[0001] The present invention relates to a device for controlling gear changes in a transmission mounted on a vehicle, and in particular to a transmission control device configured to selectively cut off the transmission of torque from a driving force source to the transmission and to set gear stages by engaging or releasing a dog clutch. [Background technology]

[0002] A control device for a transmission equipped with a dog clutch is described in Patent Document 1. The dog clutch is an engagement mechanism configured to transmit torque by meshing dog teeth arranged in a circumferential direction, and is configured to move the dog teeth in the direction of the rotation axis to engage or release them. Therefore, when the dog teeth are brought close to each other so as to mesh with each other, if the phases of the dog teeth are the same, the top surfaces (tip portions) of the dog teeth will abut against each other and the dog teeth will not be able to mesh with each other. In the device described in Patent Document 1, in order to eliminate such inconveniences when engaging the dog clutch, 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 phase between the dog teeth. For example, when the top surfaces of the dog teeth abut against each other and the dog clutch does not engage, the torque of the motor provided on the input side is changed to shift the phase between the dog teeth.

[0003] In addition, since the torque is transmitted through the tooth surfaces of the dog teeth that are meshed with each other, when the dog teeth are meshed with each other, a large surface pressure is applied to each tooth surface. Therefore, when the dog teeth are moved in the axial direction to release the dog clutch, if the surface pressure of the tooth surfaces is high, the frictional force on the tooth surfaces 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 released from the meshing of the dog teeth, the contact pressure (surface pressure) between the dog teeth is reduced to release the meshing of the dog teeth. Specifically, the device described in Patent Document 2 is configured to turn off the motor and, when the release of the dog clutch is not detected, to apply torque from a motor provided on the input side of the dog clutch to the dog clutch to reduce the frictional force of the tooth surfaces. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-104671 A [Patent Document 2] Japanese Patent Application Publication No. 11-91389 Summary of the Invention [Problem to be solved by the invention]

[0005] In the device described in Patent Document 1, when the top surfaces of the dog teeth come into contact with each other when the dog clutch is engaged and the dog clutch cannot be engaged, the phase of the dog teeth is made different by a motor provided on the input side of the dog clutch. In addition, in the device described in Patent Document 2, when the contact pressure or frictional force between the dog teeth is large and the dog clutch cannot be released, the frictional force between the dog teeth is reduced by a motor provided on the input side of the dog clutch. In this way, in the past, the torque of a motor provided on the input side of the dog clutch is used to change the phase of the dog teeth or reduce the frictional force when the dog clutch is engaged or released. On the other hand, some vehicles equipped with a transmission are provided with a clutch that can selectively cut off torque on the input side of the transmission depending on the structure of the transmission, and the gear shift is performed with the clutch released to cut off the input torque. In this type of vehicle, when engaging a dog clutch to change the gear ratio (when changing gears), if the top faces of the dog teeth of the dog clutch that is to be engaged for the gear change butt against each other and the dog clutch cannot be engaged, or if the frictional force between the dog teeth is too great and the dog clutch cannot be released, the clutch is not released to transmit torque to the transmission, so the phase of the dog teeth or the frictional force of the dog clutch cannot be changed, and ultimately it may not be possible to easily resolve the above-mentioned inability to engage or release.

[0006] The present invention has been made in consideration of the above-mentioned technical problems, and aims to provide a control device that can easily resolve an inengageable state of a dog clutch built into a transmission caused by, for example, contact of the so-called top surface thereof, and can engage the dog clutch, even when a clutch provided on the input side of the transmission is released. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a control device for a vehicle transmission, in which a transmission which sets a predetermined gear stage by engaging a dog clutch is connected to a driving force source via an input clutch which selectively transmits and interrupts torque, the dog clutch has driving side dog teeth to which torque is transmitted via the input clutch and driven side dog teeth which mesh with the driving side dog teeth to transmit torque, and is configured to relatively move the driving side dog teeth and the driven side dog teeth in the direction of a rotation center axis to bring the driving side dog teeth into engagement with each other, The drive shaft driving mechanism further includes a separate shaft drive mechanism that changes the torque of a driven side dog tooth, and a controller that controls the torque by the separate shaft drive mechanism, and when the drive side dog tooth and the driven side dog tooth are moved relatively in the axial direction to engage with each other with the input clutch released, the controller detects whether the drive side dog tooth and the driven side dog tooth are in contact and not engaged after starting control to engage the drive side dog tooth and the driven side dog tooth, and if the engagement is not detected, changes the torque of the driven side dog tooth by the separate shaft drive mechanism. Effect of the Invention

[0008] In the present invention, when the input clutch is released and control is performed to engage the dog clutch in a state in which torque from the driving force source cannot be input to the transmission, if the driving side dog tooth and the driven side dog tooth come into contact and are not engaged, the torque of the driven side dog tooth is changed by the separate shaft drive mechanism. In this case, the driving side dog tooth comes into contact with the driven side dog tooth, so that the driving side dog tooth tends to rotate together with the driven side dog tooth. On the other hand, even if the input clutch is released and the driving side dog tooth is separated from the driving force source and the torque of the driving force source does not act on it, inertia torque and torque due to friction act on the driving side dog tooth, so that the change in the torque of the driven side dog tooth causes relative rotation between the driven side dog tooth and the driving side dog tooth, resulting in a phase shift between the driven side dog tooth and the driving side dog tooth. In other words, the contact between the top surfaces of the driven side dog teeth and the driving side dog teeth is released, so that even when the driven side dog teeth and the driving side dog teeth are engaged and the input clutch is released, the so-called contact between the top surfaces of the dog teeth is released and the dog clutch can be easily engaged. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a schematic diagram of an example of a vehicle to which the present invention can be applied; [Diagram 2] FIG. 2 is a diagram showing a schematic diagram of an example of the dog clutch. [Diagram 3] 4 is a flowchart illustrating an example of control executed in the embodiment of the present invention. [Figure 4] 13 is a schematic time chart for explaining changes that occur when control is performed to eliminate top surface stoppage by using torque on another axis. [Diagram 5] 11 is a schematic time chart for explaining changes that occur when control is performed to eliminate top surface stoppage by using input torque. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, a specific example of the present invention will be described. Note that the specific example described below is merely one example of the present invention and does not limit the present invention.

[0011] First, a vehicle that can be the subject of the present invention is shown in Fig. 1. The vehicle shown here is a hybrid vehicle (electric vehicle) that uses an internal combustion engine and a motor (or a motor generator) as driving power sources, with an internal combustion engine (Eng., hereafter referred to as engine) 1 mounted at the front of the vehicle facing the rear, and a first motor (MG1) 2 having a power generating function 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.

[0012] The input clutch 3 is a clutch that selectively interrupts torque transmission between the so-called main driving force source consisting of the engine 1 and the first motor 2 and the transmission 4, and is configured, for example, as a friction clutch. The transmission 4 is a power transmission mechanism that appropriately sets the ratio of the rotational speeds (gear ratio) between the input shaft 5 and the output shaft 6, and is configured to set a predetermined gear ratio by switching a torque transmission path consisting of a plurality of gear trains (not shown) according to the engaged / disengaged states of a plurality of dog clutches. This transmission 4 may be a vehicle transmission of a conventionally known configuration.

[0013] A dog clutch is an engagement mechanism that transmits torque by meshing dog teeth. It may be a dog clutch configured such that a driving member and a driven member are arranged opposite to each other in the direction of the rotation central axis and dog teeth are provided on their opposing surfaces, or a clutch configured such that spline teeth are formed on the outer periphery of a driving member and a driven member arranged adjacent to each other on the same rotation central axis, a sleeve having spline teeth (i.e., dog teeth) formed on its inner periphery that engage with the spline teeth is provided movably in the direction of the rotation central axis, and the driving member and the driven member are connected to be integrated in the rotation direction by the sleeve. FIG. 2 shows a schematic example of the former dog clutch 7, in which a driving member 8 and a driven member 9 are arranged opposite to each other on the same rotation central axis and dog teeth (driving side dog teeth 10 and driven side dog teeth 11) are provided on the opposing surfaces of each member. The driving member 8 is configured to transmit torque from, for example, the input shaft 5 described above, and the driven member 9 is configured to transmit torque to the output shaft 6 described above. Furthermore, 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 move away from the other, and a shift fork 12 is engaged with the one of the members (for example, the driven side member 9).

[0014] The 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 this differential gear 13 to left and right rear wheels 14.

[0015] On the other hand, there is provided a second motor (MG2) 15 which corresponds to the separate shaft drive mechanism in the embodiment of the present invention. This second motor 15 is a motor with a power generating function (i.e. a motor generator) similar to the above-mentioned first motor 2, and is configured to output driving force to left and right front wheels 17 via a differential gear 16. Each of the motors 2, 15 is connected to an electricity storage device (BATT) 18, and is configured to operate as a motor using the power of the electricity storage device 18 to output torque, or to be driven by an external force to generate power and charge the power storage device 18.

[0016] An electronic control unit (ECU) 19 is provided to control the engine 1, the motors 2, 15, the input clutch 3, and the transmission 4 (especially the dog clutch 7). The electronic control unit 19 is mainly configured with a microcomputer, and is configured to perform calculations using signals (data) input from various sensors (not shown) and pre-stored data, and to output the results of the calculations as control command signals. Examples of data input from the sensors include a stroke signal corresponding to the engagement / release of the dog clutch 7 or a dog tooth position signal corresponding to the amount of the stroke, the rotation speed of the input shaft 5, the rotation speed of the output shaft 6, the state of charge (SOC) of the power storage device 18, the temperature of the power storage device 18, the vehicle speed, and an accelerator opening corresponding to a required driving force. The control command signals to be output include engagement / release of the dog clutch 7, engagement / release of the input clutch 3, start / stop and torque (positive torque and negative torque) of the motors 2, 15, and a gear shift command.

[0017] The gear ratio set by the transmission 4 described above is determined mainly based on the vehicle speed, the 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 releasing one of the dog clutches provided and engaging one of the other dog clutches, and therefore, during the gear shift process, the input clutch 3 is released to cut off the torque from the engine 1 or the first motor 2. When engaging one of the dog clutches, in the example described here, the driven member 9 (driven dog teeth 11) is stroked toward the driving member 8 (driving dog teeth 10), but if the positions (i.e., phases) of the dog teeth 10, 11 in the rotation direction are the same or nearly the same, the tip surfaces (top surfaces) of the dog teeth 10, 11 butt against each other, and the driven member 9 does not stroke any further. That is, a state 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 released and no torque is applied to the driving member 8 from the input side, so the driving member 8 rotates together with the driven member 9 and engagement does not progress if this continues. The control device in the embodiment of the present invention is configured to execute the control shown in Figure 3 in order to eliminate this so-called top surface stop state and engage the dog clutch.

[0018] FIG. 3 is a flow chart 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 where the judgment of the shift to switch the gear ratio is established and the input clutch 3 is released accordingly. Specifically, it is judged whether the judgment to issue a shift instruction is established (ON or not), that is, whether the judgment of the shift is established or not (step S1). If the judgment in this step S1 is negative, the routine in FIG. 3 is temporarily terminated without performing any particular control. On the contrary, if the judgment is positive, an instruction to execute the shift (i.e., an instruction to change gears) is issued (step S2). This is an instruction to control the release of the dog clutch that sets the current gear and the engagement of the dog clutch for setting the gear after the shift.

[0019] As described above, the engagement of the dog clutch is performed by stroking one dog tooth toward the other dog tooth to mesh them together. In this case, if the phases of the dog teeth match or are nearly matched, the dog teeth will not engage due to the abutment of the top faces as described above. In step S3, it is determined whether or not such a state in which the top faces abut and do not engage, that is, the top face stop, has occurred. This determination can be made based on a signal from a sensor that detects the stroke amount of the dog clutch. Specifically, it is sufficient to determine whether or not the detected value is insufficient for the stroke amount required for engagement of the dog clutch, or whether or not it is the stroke amount for the top face stop.

[0020] If the answer to step S3 is negative, i.e., if the dog clutch is engaged, the routine of Fig. 3 is terminated without performing any particular control. On the other hand, if the answer to step S3 is positive, it is determined whether the vehicle is moving (step S4). This determination can be made based on the detected vehicle speed, or based on the selected shift range and vehicle speed.

[0021] If the vehicle is traveling and the answer is YES in step S4, it is determined whether the separate shaft 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. 1 as the torque for canceling the above-mentioned top surface stop state of the dog clutch. The second motor 15 receives power from the power storage device 18 and functions as a motor to output torque, and conversely, is rotated by the torque input from the front wheels 17 and functions as a generator, charging the generated power to the power storage device 18. Therefore, if the discharge power from the power storage device 18 is limited due to the state of charge (SOC) or temperature, or if the charge power is limited, the second motor 15 may not be able to output positive or negative torque. In step S5, it is determined that there is no such limitation on the second motor 15.

[0022] If the answer in step S5 is affirmative, a torque for generating a differential rotation is output from another shaft (step S6). This control is a control for changing the torque (positive torque or negative torque) of the second motor 15. The vehicle having the configuration shown in FIG. 1 can drive the rear wheels 14 and the front wheels 17 independently, and when the transmission 4 is used for shifting, the input clutch 3 is released, so that the driving force of the rear wheels 14 is reduced. In contrast, the driving force of the front wheels 17 is increased by the second motor 15, so that the overall driving force of the vehicle is secured before and after the shifting. 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 changes, so that the torque of the output shaft 6 of the transmission 4 and the torque of the driven member of the dog clutch change, and the rotation speed changes. When the dog clutch is stopped at the top surface, for example, the driving member 8 and the driven member 9 shown in FIG. 2 rotate together due to the frictional force at the top surfaces that are in contact with each other. In this state, when the rotation speed of the driven member 9 changes due to a change in the torque of the driven member 9, a 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 thus generated is greater than the frictional force between the driving member 8 and the driven member 9, slippage occurs between the driving member 8 and the driven member 9, causing a change in their phase. This shift in phase between the driving member 8 and the driven member 9 is called differential rotation, and in step S6, a torque that generates this differential rotation is output.

[0023] Next, it is determined whether a predetermined time has elapsed (whether a timeout has occurred) (step S7). Here, the predetermined time is a time determined by design as a length that is equal to or longer than the time normally required for the above-mentioned differential rotation to occur and equal to or shorter than the time allowable for gear shifting. Therefore, if it is immediately after torque is output from another shaft in step S6 or if a timeout has not occurred, a negative determination is made in step S7. In that case, the process returns to the above-mentioned step S3 to determine whether the top surface has stopped.

[0024] If the top surface stop has not been released because the torque has just been output from another shaft or the torque of the other shaft has not yet increased sufficiently, the answer is affirmative in step S3. In that case, the control of steps S4 to S7 is repeated. In that case, if the predetermined time has not yet elapsed, the process returns to step S3 again to determine whether the top surface stop state has been reached. If the torque is output from another shaft and the torque becomes large enough or the amount of differential rotation becomes an amount that deviates from the top surface stop state, the top surface stop is released and the dog clutch is engaged, so the answer is negative in step S3. In that case, the routine shown in FIG. 3 is temporarily terminated. That is, the shift is completed.

[0025] On the other hand, if the predetermined time has elapsed without the top surface stop being released (if a timeout occurs), a positive determination is made in step S7. In this case, the top surface stop cannot be released even if torque is output from another shaft, that is, the dog clutch cannot be engaged, so another engagement control is executed. The engagement control in this case is a control that utilizes the torque from the input side, and therefore, first, the dog clutch is returned to neutral (step S8). This is to interrupt the 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. Next, the input clutch 3 is re-engaged (step S9). This is to rotate the drive side member 8 of the dog clutch that should be engaged.

[0026] After the input clutch 3 is re-engaged, it is determined whether the differential rotation has reached a predetermined value or more (step S10). This determination can be made based on the rotation speed of the input shaft 5 and the rotation speed of the output shaft 6. The input clutch 3 is engaged until a positive determination is made in step S10, that is, until a shift in the relative phase occurs between the drive side dog teeth 10 and the driven side dog teeth 11. Then, the input clutch 3 is released (step S11).

[0027] In this way, a shift is generated in the relative phase between the driving dog tooth 10 and the driven dog tooth 11 in the dog clutch whose top faces have been stopped, and then the process returns to step S2 to execute the gear shift again. After the control of steps S8 to S11 is performed, a shift is generated in the relative phase between the driving dog tooth 10 and the driven dog tooth 11, and the state in which the top faces of the driving dog tooth 10 and the driven dog tooth 11 face each other in the direction of the rotation axis is eliminated, so that the dog clutch is engaged by performing the gear shift again (changing gears). In other words, the answer is affirmative in step S3.

[0028] If the vehicle is stopped and the answer to step S4 is negative, the process immediately proceeds to step S8, where engagement control is performed using the torque on the input side. Similarly, if the second motor 15 cannot be sufficiently controlled and the answer to step S5 is negative, the process immediately proceeds to step S8, where engagement control is performed using the torque on the input side.

[0029] An example of the change in the position (stroke) of the dog teeth, the rotation speed, and the torque of the other shaft when the dog clutch is engaged by performing the control up to step S7 described above, that is, when the top surface stop is eliminated by using the torque of another shaft to engage the dog clutch, is shown in Figure 4. The example shown here is an example of an upshift, and when the shift from Lo (low gear) to Hi (high gear) starts (time t1), the gear change starts, so the rotation speed of the input shaft 5 decreases toward the synchronous rotation speed on the Hi side at a predetermined decreasing gradient. At the same time, the dog teeth start stroking 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 driving side member 8 connected thereto are rotated by being dragged by the driven side member 9, so the input shaft rotation speed becomes the Hi synchronous rotation speed.

[0030] Since the dog teeth do not stroke to the engagement position, the top surface stop is determined (at time t3), and the torque of the other shaft (the torque of the second motor 15 in the above example) is changed to a torque that generates the differential rotation described above. In the example shown in FIG. 4, the torque is reduced. Therefore, the synchronous rotation speeds (Hi synchronous rotation speed and Lo synchronous rotation speed), which are the rotation speeds of the output shaft 6, are reduced with the reduction in the torque of the other shaft. In contrast, the input shaft 5 and the driving side member 8 connected thereto attempt to maintain their previous rotation speeds due to their moment of inertia, so their rotation speeds are maintained at about the previous Hi synchronous rotation speed.

[0031] In this way, in the dog clutch to be engaged, relative rotation (differential rotation) occurs between the dog teeth on the driving side and the driven side, so the relative phase of the driving side dog tooth 10 and the driven side dog tooth 11, whose top faces are abutted, shifts, and these dog teeth 10, 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, which has decreased with the decrease in the torque of the other shaft (time t5).

[0032] FIG. 5 shows an example of the change in the dog tooth position (stroke), the rotation speed, and the engagement / disengagement of the input clutch 3 when the control (the control of steps S8 to S11 described above) is performed to change the input torque instead of the torque of the other shaft to eliminate the top surface stop because the vehicle is stopped or the torque of the other shaft cannot be used to engage the clutch 3. The example shown in FIG. 5 is an example of an upshift, in which a shift from the Lo gear to the Hi gear is started (time t11), a top surface stop occurs as a result of the control (time t12), and as a result, the determination of the top surface stop is established (time t13). As a result of the establishment of the determination, the dog clutch is returned to neutral (N) (time t14), and then the input clutch 3 is re-engaged (time t15).

[0033] Since the input clutch 3 is a friction clutch, its transmission torque capacity gradually increases until it reaches a predetermined value, and the input shaft rotation speed accordingly increases toward the Lo synchronous rotation speed before the start of the shift. As the input shaft rotation speed increases to the Lo synchronous rotation speed (time t16), the input clutch 3 is released, 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 synchronous rotation speed. Until then, the dog clutch is maintained in neutral, and when the input clutch 3 is almost completely released and the input shaft rotation speed has sufficiently decreased, the shift control involving gear switching is executed again (time t17). As described above, in this case, the relative phases of the top surfaces of the dog teeth are shifted, so the dog clutch is engaged (time t18), and the shift is completed.

[0034] In the above-mentioned control examples shown in FIG. 4 and FIG. 5, the rotation speed of the driven side member and the rotation speed of the driving side member in the dog clutch are changed by a separate shaft drive mechanism or an input side motor, etc., and the top surface stop state is eliminated by the associated phase change. However, the relative phase of the dog teeth that should mesh with each other may be changed by a change in rotation speed due to friction or the like. For example, the dog clutch (or the transmission 4) is put into a neutral state with the above-mentioned input clutch 3 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 a motor and the driving wheels, and are in a so-called free state. In that case, unavoidable frictional forces due to bearings, lubricating oil, etc. act, and the rotation speed of the input shaft 5 and the driving side member 8 in the free state is reduced by the frictional force or the like. Such a change in rotation speed may cause a shift in the relative phase between the driving side dog teeth 10 and the driven side dog teeth 11 to eliminate the so-called top surface stop state. [Explanation of symbols]

[0035] 1 Engine 2 Motors 3 Input clutch 4-speed 5 Input shaft 6 Output shaft 7 Dog clutch 8 Driving side member 9 Driven side member 10 Drive side dog teeth 11 Driven side dog teeth 12 Shift fork 14 Rear wheel 15 Motor 17 Front wheel 19 Electronic control device

Claims

[Claim 1] A control device for a vehicle transmission, wherein a transmission which sets a predetermined gear stage by engaging a dog clutch is connected to a driving force source via an input clutch which selectively transmits and interrupts torque, the dog clutch has driving side dog teeth to which torque is transmitted via the input clutch and driven side dog teeth which mesh with the driving side dog teeth to transmit torque, and is configured to relatively move the driving side dog teeth and the driven side dog teeth in a rotation axis direction to bring the driving side dog teeth into engagement with each other, a separate shaft drive mechanism that changes the torque of the driven dog teeth; A controller for controlling a torque by the separate shaft drive mechanism, The controller: When the driving side dog tooth and the driven side dog tooth are relatively moved in the axial direction to be engaged with each other while the input clutch is released, after starting control to engage the driving side dog teeth with the driven side dog teeth, detecting whether the driving side dog teeth and the driven side dog teeth are in contact with each other and not engaged with each other; When the engagement is not detected, the torque of the driven dog tooth is changed by the separate shaft drive mechanism. A control device for a vehicle transmission comprising:

Images