JP6911519B2 - Control device for automatic transmission - Google Patents

Description

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

Conventionally, various automatic transmissions that shift gears by re-grabbing a plurality of friction fastening elements have been known. For example, a first clutch (friction engaging element) provided between the engine and the odd-stage gear train and a second clutch (friction engaging element) provided between the engine and the even-stage gear train are provided. A dual clutch transmission (DCT) that transmits a driving force from an engine to the output side via a first clutch or a second clutch is known. In addition, it is equipped with a clutch (friction fastening element) that stops the relative rotation of the elements that make up the planetary gear, and a brake (friction fastening element) that stops the rotation of the element, and the driving force from the engine is transmitted via the planetary gear. An automatic transmission (AT) that transmits to the output side is known.

Re-grabbing a plurality of friction fastening elements in these automatic transmissions, that is, releasing one friction fastening element and fastening the other friction fastening element in parallel with each other generates frictional heat at each friction fastening element. .. Excessive frictional heat generation damages the friction fastening elements. Therefore, some kind of heat measures are required. On the other hand, it is not desirable to give the driver an unpredictable acceleration / deceleration feeling at the time of shifting because it reduces drivability.

Therefore, inventions have been proposed in which both prevention of damage to the friction fastening element and drivability at the time of re-grasping the friction fastening element are achieved.

For example, Patent Document 1 discloses an invention relating to a shift control method for a DCT vehicle. The method is described as "a shift command confirmation stage for confirming whether or not a shift-up shift command is generated during the start control of the DCT vehicle; A slip determination stage for determining whether the rotation speed difference between the rotation speed of the input shaft to be synchronized and the engine rotation speed is within a predetermined reference rotation speed; When the difference between the number and the engine speed is within the reference speed order, the control conversion step of ending the start control and switching to the shift control ”(claim 1) is included.

Japanese Unexamined Patent Publication No. 2014-556666

According to the method described in Patent Document 1, as shown in FIG. 3 of Patent Document 1, the rotation speed of the input shaft of the transmission in the clutch to be released continues to increase through before and after the grip change. That is, the vehicle continues to accelerate even during the shift as before the shift. This means that the friction fastening element has a relatively high torque capacity even at the time of re-grasping. Therefore, the temperature of the friction fastening element may rise excessively during shifting.

The present invention has been made in view of such a situation, and provides a control device for an automatic transmission capable of preventing excessive heat generation of the friction fastening element when re-grasping the friction fastening element. Is the subject.

The control device for an automatic transmission according to the present invention includes a determination unit for determining whether or not a shift execution condition for reducing the output torque of the automatic transmission is satisfied prior to re-grabbing a plurality of friction fastening elements. When it is determined by the determination unit that the execution condition of the shift is satisfied , the output torque of the automatic transmission is reduced prior to the grip change, and then the output torque of the automatic transmission is passed through the grip change step. Is provided with an execution unit that executes the shift so as to maintain the torque below the driver required engine torque according to the accelerator opening.

According to the present invention, it is possible to provide a control device for an automatic transmission capable of preventing excessive heat generation of the friction fastening element when the friction fastening element is re-grasped.

Schematic configuration diagram showing a vehicle to which the control device of the automatic transmission according to the present invention is applied. Functional block diagram of the control device for the automatic transmission according to the present invention. Flow chart showing the flow of control by the control device of the automatic transmission according to the present invention. Time chart when upshifting is performed by normal shifting Time chart when upshifting is performed by protective shifting Time chart when downshifting is performed by normal shifting Time chart when downshifting is performed by protective shifting

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment described below is an example, and the present invention is not limited to this embodiment.

First, the overall configuration of the vehicle will be described with reference to FIG. As shown in FIG. 1, the vehicle 1 includes an engine 10, a DCT2 (automatic transmission) including a first clutch 20, a second clutch 30, a transmission unit 40, and a hydraulic circuit 90, and a control device 50. .. A drive wheel is connected to the output side of the DCT2 via a propeller shaft and a differential gear (not shown) so that power can be transmitted.

The engine 10 is, for example, a diesel engine. The output rotation speed (hereinafter referred to as "engine rotation speed") and output torque of the engine 10 are controlled based on the accelerator opening Acc of the accelerator pedal detected by the accelerator opening sensor 101. Further, the engine output shaft 11 is provided with an engine speed sensor 102 that detects the engine speed.

The first clutch 20 is a hydraulically operated wet multi-plate clutch having a plurality of first input side clutch plates 21 and a plurality of first output side clutch plates 22. The first input side clutch plate 21 rotates integrally with the engine output shaft 11 rotated by the engine 10. The first output side clutch plate 22 rotates integrally with the first input shaft 41 of the transmission unit 40.

The first clutch 20 is urged in the disconnection direction by a return spring (not shown), and the first piston 23 is moved by the clutch operating hydraulic pressure supplied from the hydraulic circuit 90 to move the first input side clutch plate 21 and the first clutch plate 20. 1 The output side clutch plate 22 is brought into contact by pressure contact. When the first clutch 20 is engaged, the power of the engine 10 is transmitted to the first input shaft 41. The engagement and disengagement of the first clutch 20 is controlled by the control device 50. The first clutch 20 may be a dry single plate clutch.

The second clutch 30 is a hydraulically operated wet multi-plate clutch having a plurality of second input side clutch plates 31 and a plurality of second output side clutch plates 32. The second input side clutch plate 31 rotates integrally with the engine output shaft 11. The second output side clutch plate 32 rotates integrally with the second input shaft 42 of the transmission unit 40.

The second clutch 30 is urged in the disconnection direction by a return spring (not shown), and the second piston 33 is moved by the clutch operating hydraulic pressure supplied from the hydraulic circuit 90 to move the second input side clutch plate 31 and the second clutch plate 31. 2 The clutch plate 32 on the output side is brought into contact by pressure contact. When the second clutch 30 is engaged, the power of the engine 10 is transmitted to the second input shaft 42. The engagement and disengagement of the second clutch 30 is controlled by the control device 50. The second clutch 30 may be a dry single plate clutch. Hereinafter, if necessary, the first input side clutch plate 21, the second input side clutch plate 31, the first output side clutch plate 22, and the second output side clutch plate 32 are simply referred to as "clutch plates".

The second clutch 30 is provided on the outer peripheral side of the first clutch 20. Further, the first input shaft 41 is provided with a lubricating oil passage (not shown) including an axial oil passage and one or a plurality of radial oil passages, and lubricating oil is radially injected from the first input shaft 41. By doing so, each clutch plate of the first clutch 20 is cooled, and further, each clutch plate of the second clutch 30 is cooled. The lubricating oil that has cooled each clutch plate of the second clutch 30 flows out from the outer diameter side of the second clutch 30, and returns to an oil pan (not shown) provided in the hydraulic circuit 90. In this embodiment, the case where the second clutch 30 is provided on the outer peripheral side of the first clutch 20 will be described as an example, but the arrangement relationship between the first clutch 20 and the second clutch 30 is based on this. Not limited. Specifically, for example, the second clutch 30 may be arranged on the rear side of the first clutch 20.

The transmission unit 40 includes a first input shaft 41 connected to the output side of the first clutch 20, and a second input shaft 42 connected to the output side of the second clutch 30. Further, the transmission unit 40 includes a sub-shaft 43 arranged in parallel with the first input shaft 41 and the second input shaft 42, and an output shaft 44 arranged coaxially with the first input shaft 41 and the second input shaft 42. And have. Further, a vehicle speed sensor 103 for detecting the vehicle speed V, which is the speed of the vehicle 1, is provided on the rear end side of the output shaft 44.

The speed change unit 40 includes a first speed change unit 60, a second speed change unit 70, and a forward / reverse advance switching unit 80. The first transmission unit 60 includes a first high-speed gear train 61, a first low-speed gear train 62, and a first connection mechanism 63.

The first high-speed gear train 61 is provided so as to mesh with the first input gear 61a provided so as to be rotatable relative to the first input shaft 41 and to rotate integrally with the sub-shaft 43. It is composed of a first sub gear 61b.

The first low-speed gear train 62 is provided so as to mesh with the second input gear 62a provided so as to be rotatable relative to the first input shaft 41 and the second input gear 62a so as to rotate integrally with the sub-shaft 43. It is composed of a second auxiliary gear 62b.

The first connecting mechanism 63 selectively selects the first input gear 61a and the second input gear 62a by moving the first sleeve 63a in the axial direction (left-right direction in FIG. 1) by a gear shift actuator (not shown). 1 Rotate integrally with the input shaft 41.

The second transmission unit 70 includes a second high-speed gear train 71, a second low-speed gear train 72, and a second connecting mechanism 73. The second high-speed gear train 71 is provided so as to mesh with the third input gear 71a provided so as to be rotatable relative to the second input shaft 42 and the third input gear 71a so as to rotate integrally with the sub-shaft 43. It is composed of a third auxiliary gear 71b.

The second low-speed gear train 72 is provided so as to mesh with the fourth input gear 72a provided so as to be rotatable relative to the second input shaft 42 and the fourth input gear 72a and rotate integrally with the sub-shaft 43. It is composed of a fourth auxiliary gear 72b.

The second connecting mechanism 73 selectively rotates the third input gear 71a and the fourth input gear 72a integrally with the second input shaft 42 by moving the second sleeve 73a in the axial direction by a gear shift actuator (not shown). Let me.

The forward / backward switching unit 80 includes a forward gear row 81, a reverse gear row 82, and a third connecting mechanism 83. The forward gear train 81 meshes with the first output gear 81a provided so as to be rotatable relative to the output shaft 44 and the first output gear 81a, and is provided so as to rotate integrally with the auxiliary shaft 43. It consists of a gear 81b.

The reverse gear train 82 is provided so as to mesh with the second output gear 82a provided so as to be rotatable relative to the output shaft 44 via the second output gear 82a and the idler gear 82c so as to rotate integrally with the auxiliary shaft 43. It is composed of the 6th auxiliary gear 82b.

The third connecting mechanism 83 selectively rotates the first output gear 81a and the second output gear 82a integrally with the output shaft 44 by moving the third sleeve 83a in the axial direction by a gear shift actuator (not shown).

Here, the power transmission path in DCT2 will be briefly described. In the first speed, the second input gear 62a and the first input shaft 41 are connected by the first connecting mechanism 63, the first output gear 81a and the output shaft 44 are connected by the third connecting mechanism 83, and the first clutch. It is established by connecting 20. As a result, the power of the engine 10 is transmitted from the first clutch 20 in the order of the first input shaft 41, the first low speed gear train 62, the sub shaft 43, the forward gear train 81, and the output shaft 44.

In the second speed, the fourth input gear 72a and the second input shaft 42 are connected by the second connecting mechanism 73, the first output gear 81a and the output shaft 44 are connected by the third connecting mechanism 83, and the second clutch. It is established by making 30 a contact. As a result, the power of the engine 10 is transmitted from the second clutch 30 in the order of the second input shaft 42, the second low speed gear train 72, the sub shaft 43, the forward gear train 81, and the output shaft 44.

In the third speed, the first input gear 61a and the first input shaft 41 are connected by the first connecting mechanism 63, the first output gear 81a and the output shaft 44 are connected by the third connecting mechanism 83, and the first clutch. It is established by connecting 20. As a result, the power of the engine 10 is transmitted from the first clutch 20 in the order of the first input shaft 41, the first high-speed gear train 61, the sub shaft 43, the forward gear train 81, and the output shaft 44.

In the 4th speed, the 3rd input gear 71a and the 2nd input shaft 42 are connected by the 2nd connecting mechanism 73, the 1st output gear 81a and the output shaft 44 are connected by the 3rd connecting mechanism 83, and the 2nd clutch. It is established by making 30 a contact. As a result, the power of the engine 10 is transmitted from the second clutch 30 in the order of the second input shaft 42, the second high-speed gear train 71, the sub shaft 43, the forward gear train 81, and the output shaft 44.

The control device 50 includes a CPU 51, a memory 52, and an interface (not shown) that is connected to various sensors and devices to send and receive signals. The CPU 51 controls the engine 10 by executing the program stored in the memory 52, and also controls the DCT2 through the control of the hydraulic circuit 90. Specifically, by executing the program stored in the memory 52, the CPU 51 executes a shift condition establishment determination unit 53 and a protective shift execution determination unit 54 (corresponding to the determination unit in the present invention) as shown in FIG. ) And the execution unit 55.

The shift condition establishment determination unit 53 determines whether or not the shift condition for upshift or downshift is satisfied based on the accelerator opening degree Acc, the vehicle speed V, the shift map stored in the memory 52, and the like.

The protective shift execution determination unit 54 determines whether or not the shift execution condition for reducing the output torque of the DCT2 is satisfied prior to re-grabbing the first clutch 20 and the second clutch 30 (a plurality of friction engaging elements). do. Hereinafter, such a shift will be referred to as a "protective shift" as necessary.

The execution unit 55 executes the protection shift when it is determined by the protection shift execution determination unit 54 that the execution condition of the protection shift is satisfied.

Further, when the execution unit 55 determines that the shift condition is satisfied by the shift condition establishment determination unit 53, but the protection shift execution determination unit 54 determines that the protection shift execution condition is not satisfied, the execution unit 55 determines that the protection shift execution condition is not satisfied. Performs a shift different from the protective shift. The shift performed at this time is a shift in which the output torque of the DCT2 is not reduced prior to the replacement of the first clutch 20 and the second clutch 30. Hereinafter, such a shift will be referred to as a "normal shift" as necessary.

The execution unit 55 engages and disengages the first clutch 20 and disengages the second clutch 30 via the hydraulic circuit 90, and moves the first sleeve 63a, the second sleeve 73a, and the third sleeve 83a. Performs an upshift or a downshift in either the protective shift or the normal shift.

It should be noted that it is not necessary that all of the functional units described above are realized by the control device 50, and any one or more of the functional units described above is another control device different from the control device 50. May be realized by. For example, the control device 50 may be configured to function as a protective shift execution determination unit 54 and an execution unit 55. Further, it goes without saying that any one of the above-described functional units may be configured to also serve as the function of the other functional unit.

Subsequently, the shift control by the control device of the transmission according to the present embodiment will be described in detail with reference to the flowchart of FIG.

First, the shift condition establishment determination unit 53 determines whether or not the shift condition for upshift or downshift is satisfied (S1). While it is determined that the shift condition is not satisfied (NO in S1), the determination of whether or not the shift condition is satisfied is repeated until it is determined that the shift condition is satisfied (YES in S1).

When it is determined that the shift condition is satisfied, the protection shift execution determination unit 54 determines whether or not the protection shift execution condition is satisfied (S2). The execution condition of the protective shift is, for example, the temperature at the start of the shift of the clutch on the side of the first clutch 20 and the second clutch 30 that is engaged by gripping, or the estimated temperature at the completion of the shift of the clutch. It can be set to be equal to or higher than a predetermined threshold value.

When the protection shift execution determination unit 54 determines that the protection shift execution condition is satisfied (YES in S2), the execution unit 55 executes the protection shift of upshift or downshift (S3). On the other hand, when the protection shift execution determination unit 54 determines that the protection shift execution condition is not satisfied (NO in S2), the execution unit 55 executes an upshift or downshift normal shift (S4).

Before explaining the protective shift, the normal shift will be described with reference to FIG. 4, which shows a time chart of the normal shift. Here, the case where the upshift is performed from the 3rd speed to the 4th speed will be described as an example.

When the normal shift is started, first, as shown in the chart in the middle stage, the execution unit 55 reduces the torque capacity (transmissible torque) of the first clutch 20 to the engine torque. At this time, the engine torque matches the driver-required engine torque.

Subsequently, the execution unit 55 gradually increases the torque capacity of the second clutch 30 while gradually reducing the torque capacity of the first clutch 20. That is, the clutch is re-grasped.

As a result, as shown in the lower chart, the output torque of the first clutch system, which is the torque transmitted to the output shaft 44 via the first clutch 20 and the first transmission unit 60, gradually decreases. Further, the output torque of the second clutch system, which is the torque transmitted to the output shaft 44 via the second clutch 30 and the second transmission unit 70, gradually increases. The transmission output torque (DCT2 output torque), which is the torque output from the output shaft 44, is the sum of the first clutch system output torque and the second clutch system output torque. At the time of normal shift execution, the execution unit 55 controls the torque capacity of each clutch so that the transmission output torque matches the driver required output torque before and after the grip change.

When the output torque of the first clutch system becomes 0 and the output torque of the transmission becomes equal to the output torque of the second clutch system, the execution unit 55 performs control as follows. That is, as shown in the middle chart, the execution unit 55 maintains the torque capacity of the second clutch 30 at the same value as the engine torque when the clutch is being re-grasped for a predetermined time, and the engine. The torque is reduced by a predetermined amount. As a result, as shown in the upper chart, the engine speed changes from the speed of the first input shaft 41 to the speed of the second input shaft 42. When the engine speed matches the speed of the second input shaft 42, no slippage occurs in any of the clutches.

When the engine speed matches the speed of the second input shaft 42, the execution unit 55 increases the torque capacity of the second clutch 30 by a predetermined amount so as not to cause slippage, as shown in the middle chart. As a result, the 4th speed is achieved and the normal shift is completed.

During normal shifting, the transmission output torque matches the driver-required output torque. Therefore, it is unlikely that the driver will feel uncomfortable while shifting gears are being executed. However, as a result of the relatively high transmission output torque, the energy absorbed by each clutch at the time of re-grasping also becomes relatively large, so that the temperature of each clutch tends to rise.

Next, the protection shift will be described with reference to FIG. 5, which shows a time chart of the protection shift. Here, it is assumed that the upshift from the 3rd speed to the 4th speed is performed.

When the protective shift is started, first, as shown in the lower chart, the execution unit 55 reduces the transmission output torque from the driver required output torque to a predetermined output torque. Specifically, as shown in the middle chart, the execution unit 55 reduces the engine torque to a predetermined value and reduces the torque capacity of the engaged clutch, the first clutch 20, to the predetermined value. ..

The predetermined output torque is predetermined based on the experimental results, how the vehicle 1 is used, the vehicle type, and the like. Further, it can be determined based on the temperature at the start of shifting of the clutch on the side engaged by gripping, or the difference between the estimated temperature at the completion of shifting of the clutch and a predetermined threshold value.

In any case, the predetermined output torque is preferably zero acceleration output torque, which is a torque capable of maintaining the vehicle speed at the start of the protective shift, or a torque larger than that. By doing so, even if the execution unit 55 reduces the transmission output torque, the vehicle 1 can travel without decelerating. For example, even when the protective shift is performed while traveling on an uphill road, the vehicle 1 can continue traveling without stalling. The zero acceleration output torque can be obtained from the following equation 1.

In Equation _{1, T} 0acc0 zero acceleration output torque, _{r w} is the tire radius, _{i f} the final gear ratio, symbol ^ with _{F aero} air resistance estimation value, the symbol ^ with _{F roll} is rolling estimate, g is the gravitational Acceleration, m with the symbol ^ is the vehicle weight, and θ with the symbol ^ is the slope estimation value. Each parameter on the right side of Equation 1 can be determined in advance or can be obtained by a method known at the time of filing the application of the present application. Therefore, detailed description will be omitted.

Further, it is preferable to reduce the transmission output torque from the driver required output torque to the predetermined output torque so as not to give the driver a sense of discomfort. That is, the reduction of the transmission output torque prior to the re-grabbing of the two clutches is performed at a changing speed so that the jerk of the vehicle 1 during the reduction does not become a value that gives the driver a sense of discomfort. Is preferable. For example, the execution unit 55 reduces the transmission output torque so as to satisfy the following formula 2. The jerk referred to here is a forward jerk, which is a jerk in the traveling direction of the vehicle 1.

In Equation 2, the symbol ... means the first-order time derivative, and the symbol ... means the second-order time derivative. _Toi is the transmission output torque. Therefore, _{the first-order time derivative value of Toi} means the rate of change of the transmission output torque. Further, v _x is the forward speed of the vehicle 1. Therefore, the second-order time derivative means the forward jerk of the vehicle 1. The other symbols are the same as those in Equation 1.

As _{a suitable value range of the second-order time derivative value of v x} (front jerk of vehicle 1), a range of values that the driver does not feel uncomfortable is experimentally obtained in advance and stored in the memory 52. Therefore, by substituting such a value into Equation 2 and changing the transmission output torque at a change speed within the numerical range obtained, the transmission output can be performed prior to re-grabbing the clutch without giving a sense of discomfort to the driver. The torque can be reduced.

Subsequently, as shown in the middle chart, the execution unit 55 gradually increases the torque capacity of the second clutch 30 while gradually reducing the torque capacity of the first clutch 20. That is, the clutch is re-grasped.

As a result, as shown in the lower chart, the output torque of the first clutch system, which is the torque transmitted to the output shaft 44 via the first clutch 20 and the first transmission unit 60, gradually decreases. Further, the output torque of the second clutch system, which is the torque transmitted to the output shaft 44 via the second clutch 30 and the second transmission unit 70, gradually increases. The transmission output torque, which is the torque output from the output shaft 44, is the sum of the first clutch system output torque and the second clutch system output torque. During the protection shift execution, the execution unit 55 controls the torque capacity of each clutch while maintaining a state in which the transmission output torque is less than the driver required output torque and equal to or more than the zero acceleration output torque before and after the grip change. ..

When the output torque of the first clutch system becomes 0 and the output torque of the transmission becomes equal to the output torque of the second clutch system, the execution unit 55 controls the torque capacity of the second clutch 30 as follows. That is, as shown in the middle chart, the execution unit 55 maintains the torque capacity of the second clutch 30 at the engine torque when the clutch is being re-grasped for a predetermined time, and determines the engine torque. Quantitative reduction. As a result, as shown in the upper chart, the engine speed changes from the speed of the first input shaft 41 to the speed of the second input shaft 42. When the engine speed matches the speed of the second input shaft 42, no slippage occurs in any of the clutches.

When the engine speed matches the speed of the second input shaft 42, the execution unit 55 sets the torque capacity of the second clutch 30 to the torque capacity of the first clutch 20 before the start of shifting, as shown in the middle chart. Increase to be equal to. It also restores the engine torque to the driver-required engine torque. As a result, the 4th speed is achieved and the protective shift is completed.

During the protective shift execution, the first clutch 20 and the second clutch 30 are slipping in the step of re-grabbing the first clutch 20 and the second clutch 30. Further, in the transition process of the engine speed, the second clutch 30 is slipping. However, the torque capacity of each clutch is reduced through these steps as compared with the time when the normal shift is executed. Therefore, the energy absorbed by each clutch is reduced, and the amount of heat generated by each clutch is smaller than that during normal shifting. That is, excessive heat generation in each clutch can be prevented by performing the protective shift. Moreover, since the clutch re-grabbing step and the engine speed transition step are performed in a state where the transmission output torque, which is the output torque of the DCT2, is reduced, the amount of heat generated in each clutch can be reduced more reliably.

The protective shift according to the present invention can also be applied to the case of downshift. FIG. 6 is a time chart when the downshift from the 3rd speed to the 2nd speed is executed by the normal shift. Further, FIG. 7 is a time chart in the case where the downshift from the 3rd speed to the 2nd speed is executed by the protective shift.

As is clear from these time charts, when the downshift is executed by the protective shift, the transmission output torque is increased in the transition process of the engine speed and the gripping process of the first clutch 20 and the second clutch 30. It has been reduced. That is, the torque capacity of each clutch is reduced through these steps. Therefore, the amount of heat generated by each clutch is smaller than that during normal shifting. That is, excessive heat generation in each clutch can be prevented by performing the protective shift.

The automatic transmission may be a DCT having a larger number of gear trains and capable of shifting in more stages, a clutch that stops the relative rotation of the elements constituting the planetary gear, and a clutch that stops the rotation of the elements. It may be an automatic transmission provided with a braking brake.

According to the present invention, it is possible to provide a control device for an automatic transmission capable of preventing excessive heat generation of the friction fastening element when the friction fastening element is re-grasped. Therefore, its industrial applicability is enormous.

1 vehicle 2 DCT
10 Engine 11 Engine output shaft 20 1st clutch 21 1st input side clutch plate 22 1st output side clutch plate 23 1st piston 30 2nd clutch 31 2nd input side clutch plate 32 2nd output side clutch plate 33 2nd piston 40 Transmission 41 1st input shaft 42 2nd input shaft 43 Sub shaft 44 Output shaft 50 Control device 51 CPU
52 Memory 53 Shift condition establishment judgment unit 54 Protective shift execution judgment unit 55 Execution unit 60 1st transmission unit 61 1st high speed gear train 61a 1st input gear 61b 1st auxiliary gear 62 1st low speed gear train 62a 2nd input gear 62b 2nd auxiliary gear 63 1st connection mechanism 63a 1st sleeve 70 2nd transmission 71 2nd high speed gear row 71a 3rd input gear 71b 3rd auxiliary gear 72 2nd low speed gear row 72a 4th input gear 72b 4th auxiliary gear 73 2nd connecting mechanism 73a 2nd sleeve 80 Forward / backward switching part 81 Forward gear row 81a 1st output gear 81b 5th auxiliary gear 82 Reverse gear row 82a 2nd output gear 82b 6th auxiliary gear 82c Idler gear 83 3rd connecting mechanism 83a Third sleeve 101 Accelerator opening sensor 102 Engine speed sensor 103 Vehicle speed sensor 90 Hydraulic circuit

Claims (3)

A judgment unit that determines whether or not the execution conditions for shifting, in which the output torque of the automatic transmission is reduced prior to re-grabbing multiple friction fastening elements, are satisfied.
When it is determined by the determination unit that the execution condition of the shift is satisfied , the output torque of the automatic transmission is reduced prior to the grip change, and then the output torque of the automatic transmission is passed through the grip change step. A control device for an automatic transmission, comprising an execution unit that executes the shift so as to maintain the torque below the driver required engine torque according to the accelerator opening. During the execution of the shift, the execution unit maintains the output torque of the automatic transmission at a torque that can maintain the vehicle speed when the determination unit determines that the execution condition of the shift is satisfied.
The control device for an automatic transmission according to claim 1. The execution unit is the automatic transmission at a speed at which the jerk of the vehicle during the reduction is within a predetermined range predetermined so that the driver of the vehicle does not feel uncomfortable. The control device for an automatic transmission according to claim 1 or 2, which reduces the output torque of the automatic transmission.

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