JP2013053732A - Automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic transmission that includes a fuel safe function of suppressing driving torque of a prime mover when a clutch is determined to be in failure.SOLUTION: The automatic transmission includes: a clutch failure determination part (S106) which determines that the clutch 20 is in failure, if a rotation of a drive shaft 12 of the prime mover 11 cannot be synchronized with a rotation of an input shaft 31 of a transmission 17, when an actuator 25 is positioned where the maximum torque can be transmitted; and a torque suppression control part (S112 and S114) for reducing the driving torque of the prime mover, when the clutch failure determination part determines that the clutch is in failure.

Description

  The present invention relates to an automatic transmission that controls engagement / disengagement of a clutch provided between a prime mover and a transmission with a clutch actuator, and more particularly to an automatic transmission having a fail-safe function when a clutch is abnormal.

  Conventionally, in a vehicle using an engine as a drive source, for example, as described in Patent Document 1, an actuator is attached to an existing manual transmission, and a shift operation (clutch connection / disconnection is performed depending on the driver's intention or the vehicle state). , Gear shift, and select) automatically (hereinafter referred to as AMT (Automated Manual Transmission)), for example, as described in Patent Document 2, two clutches and two input shafts are provided. A dual clutch automatic transmission (DCT) having a pre-shift is known.

  In this type of DCT or AMT, when the clutch is engaged, in order to synchronize the engine speed Ne and the input shaft speed Nt of the automatic transmission, the clutch torque Tc is set by the clutch actuator as shown in FIG. As shown in FIG. 4, the engine torque Te is controlled to be larger by + α than the engine torque Te.

JP 2008-75814 A JP 2010-196745 A

  However, if any abnormality occurs in the clutch or the clutch system, even if the clutch actuator is stroked by a predetermined amount due to, for example, foreign matter biting or wear of the clutch disc, the clutch torque Tc remains the target as shown in FIG. The clutch torque Tct is not increased, and only a torque Tcz smaller than the engine torque Te can be obtained. For this reason, the engine speed Ne cannot be synchronized with the input shaft speed Nt as indicated by the solid line in FIG.

  In such a case, in order to increase the clutch torque Tc to the target torque, the operation of the clutch actuator is continued and an unreasonable weighting operation is repeated. In such a state, when shifting and running are performed. The clutch may be damaged.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide an automatic transmission having a fail-safe function for suppressing the driving torque of a prime mover when it is determined that a clutch abnormality has occurred. Is.

  In order to solve the above-mentioned problem, a feature of the invention according to claim 1 is that the motor is mounted on the vehicle, and the rotation of the input shaft rotated by the driving shaft of the motor is shifted to a gear ratio of a plurality of stages to change the vehicle. A transmission for transmitting to the drive wheels, a clutch for engaging and disengaging the drive shaft of the prime mover and the input shaft of the transmission, a clutch actuator for controlling the clutch torque of the clutch, and the clutch actuator for transmitting maximum torque. When the rotation of the drive shaft of the prime mover and the rotation of the input shaft of the transmission cannot be synchronized when in a position where they can be, the clutch abnormality determination unit that determines that the clutch is abnormal and the clutch abnormality determination unit A torque suppression control unit that reduces the driving torque of the prime mover when it is determined to be abnormal.

  According to a second aspect of the present invention, in the first aspect, the torque suppression control unit is configured to reduce the driving torque of the prime mover to a value lower than a torque that the clutch cannot transmit and less than a torque that the clutch can transmit. It is that.

  According to a third aspect of the present invention, in the first or second aspect, the torque suppression control unit gradually decreases the driving torque of the prime mover by a predetermined amount until a slip amount of the clutch becomes a predetermined amount or less. It is like that.

  According to a fourth aspect of the present invention, in the first or second aspect, when the clutch abnormality determining unit determines that the clutch is abnormal, the clutch can transmit based on the speed change speed of the prime mover. By having a transmittable torque calculation unit for calculating a transmittable torque, the driving torque of the prime mover is reduced by the torque suppression control unit to less than the transmittable torque calculated by the transmittable torque calculation unit. is there.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the clutch transmits the driving torque of the prime mover to a first input shaft connected to the odd-numbered speed side. This is constituted by a dual clutch including a first clutch and a second clutch that is transmitted to a second input shaft connected to the even-numbered speed side.

  According to the first aspect of the invention, when the clutch actuator is at a position where the maximum torque can be transmitted, if the rotation of the drive shaft of the prime mover and the rotation of the input shaft of the transmission cannot be synchronized, it is determined that the clutch is abnormal. And a torque suppression control unit that reduces the driving torque of the prime mover when the clutch abnormality determination unit determines that the clutch is abnormal.

  With this configuration, a fail-safe function that suppresses and controls the drive torque of the prime mover is demonstrated in the event of a clutch abnormality, and the engine speed can be synchronized with the input shaft speed without causing the clutch to break down. Even at times, the vehicle can be driven safely.

  According to the second aspect of the present invention, the torque suppression control unit reduces the driving torque of the prime mover to less than the torque that can be transmitted by the clutch lower than the torque at which the clutch cannot transmit torque. By reducing the torque to below the torque that can be transmitted by the clutch, the engine speed can be reliably synchronized with the input shaft speed.

  According to the third aspect of the present invention, the torque suppression control unit gradually decreases the driving torque of the prime mover by a predetermined amount until the slip amount of the clutch becomes a predetermined amount or less. While monitoring, the driving torque of the prime mover can be accurately reduced to a required level.

  According to the fourth aspect of the present invention, the transmittable torque calculating unit that calculates the transmittable torque that can be transmitted by the clutch based on the speed change speed of the prime mover when the clutch abnormality determining unit determines that the clutch is abnormal. Since the drive torque of the prime mover is reduced by the torque suppression control unit to less than the transmittable torque calculated by the transmittable torque calculation unit, the drive torque of the prime mover can be reduced to less than the transmittable torque by simple control. It can be quickly reduced.

  According to the fifth aspect of the present invention, the clutch includes a first clutch that transmits the driving torque of the prime mover to the first input shaft that is coupled to the odd-numbered speed side, and a second input that is coupled to the even-numbered speed side. Since it is constituted by a dual clutch comprising a second clutch that transmits to the shaft, it is possible to accurately cope with an abnormality in the first clutch and the second clutch in the dual clutch type automatic transmission.

1 is a diagram showing a vehicle equipped with an automatic transmission according to an embodiment of the present invention. It is a skeleton figure which shows the whole structure of a dual clutch type automatic transmission. It is a figure which shows the torque transmission characteristic of a clutch. It is a flowchart which shows engine torque suppression control when clutch abnormality generate | occur | produces. It is a modification of the flowchart which shows engine torque suppression control. It is a figure which shows the time chart at the time of the clutch engagement in the past.

  Hereinafter, an automatic transmission according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram in which a dual clutch type automatic transmission (DCT) 10 as an example of an automatic transmission is applied to an FF (front engine / front drive) type vehicle. In addition to the dual clutch automatic transmission 10, the vehicle includes an engine 11 driven by combustion of gasoline, which is an example of a prime mover, a differential (differential) 13, left and right drive shafts 15a and 15b, and drive wheels. Left and right front wheels 16a and 16b.

  The rotational speed Ne of the engine 11 is detected by an engine rotational speed sensor 90 provided close to the drive shaft 12 of the engine 11. The accelerator operation amount when the accelerator pedal 91 is depressed is detected by the accelerator opening sensor 92 as the accelerator opening. An ECU (Engine Control Unit) 14 that controls the operation of the engine 11 receives information on the engine speed Ne, information on the accelerator opening, and various types of information from a TCU (Transmission Control Unit) 23 that controls the shift of the automatic transmission 10. The engine control unit 14a controls the engine torque Te and the engine speed Ne by acquiring and controlling the accelerator opening and the fuel injection amount based on the information.

  The automatic transmission 10 is disposed on a power transmission path between the engine 11 and the differential device 13, and the first and second input shafts 31 a and 31 b (hereinafter collectively referred to as 31 a and 31 b are simply referred to as input shafts). 31) and a clutch 20 that engages and disengages the drive shaft 12 of the engine 11 and the input shaft 31 of the transmission 17. It has. The clutch 20 is a dual clutch having a first clutch 20a that transmits the drive torque of the drive shaft 12 output from the engine 11 to the first input shaft 31a and a second clutch 20b that transmits the second input shaft 31b. It is configured.

  The rotational speed Nt of the first input shaft 31a and the second input shaft 31b is detected by the first input shaft rotational speed sensor 93a and the second input shaft rotational speed sensor 93b, respectively. The wheel speeds of the left and right front wheels 16a and 16b and the left and right rear wheels (not shown) are detected by wheel speed sensors 94a and 94b, and these pieces of information are sent to the TCU 23. A vehicle speed (vehicle speed) is calculated based on the rotational speed of each wheel detected by the wheel speed sensors 94a and 94b.

  When the driver operates the shift lever 95, the shift position information is detected by the shift position sensor 96. The ECU 14 and the TCU 23 can exchange information with each other by CAN (Controller Area Network) communication. The shift control unit 23a of the TCU 23 switches a plurality of shift gears based on information on the shift position detected by the shift position sensor 96, a shift command from the ECU 14, acquired vehicle information, and the like. The second clutch 20b is engaged and disengaged, and the shift control of the automatic transmission 10 is performed.

  The first and second clutches 20a and 20b of the dual clutch 20 are dry friction clutches. The engagement of the first clutch 20a is controlled by a first clutch actuator 25a having a motor as a drive source, and the second clutch 20b is engaged by a second clutch actuator 25b having a motor as a drive source. Are controlled together. First and second clutch actuators 25a and 25b (hereinafter collectively referred to as 25a and 25b are simply referred to as clutch actuators 25) are stroke sensors 26a and 26b (hereinafter referred to as clutch actuators 25) that detect the stroke amount S of the clutch actuator 25, respectively. , 26a, and 26b are collectively referred to as a stroke sensor 26). The clutch torque Tc of the first and second clutches 20 a and 20 b is controlled according to the stroke amount S of the clutch actuator 25.

  As shown in FIG. 2, the dual clutch type automatic transmission 10 includes a forward gear 7 and a reverse gear 1. The dual clutch type automatic transmission 10 includes a dual clutch 20, a first input shaft 31 a and a second input shaft 31 b, a first counter shaft 35 and a second counter shaft 36. The first input shaft 31a has a rod shape, and the second input shaft 31b has a cylindrical shape and is coaxially arranged to be rotatable. The left side of the first input shaft 31a in the drawing is connected to the first clutch 20a of the dual clutch 20, and the left side of the second input shaft 31b in the drawing is connected to the second clutch 20b of the dual clutch 20. The first input shaft 31a and the second input shaft 31b are independently transmitted with torque and can be rotated at different rotational speeds. The first countershaft 35 is arranged on the lower side in the figure in parallel with the input shaft 31 (first and second input shafts 31a and 31b), and the second countershaft 36 is in parallel with the input shaft 31. It is arranged on the upper side in the figure.

  On the first input shaft 31a, a plurality of odd-speed drive gears, such as a first speed drive gear 51, a third speed drive gear 53, a fifth speed drive gear 55, and a seventh speed drive gear 57, are formed directly or fixed separately. Is provided. The second input shaft 31b is provided with a plurality of even-speed drive gears 52, a second speed drive gear 52 and a 4-6 speed drive gear 54, which are directly formed or separately fixed.

  The first countershaft 35 is provided with first, third, and fourth-speed driven gears 61, 63, and 64, respectively, so that the first-speed driven gear 61 and the third-speed driven gear 63 can rotate. Is meshed with the third speed drive gear 53, and the fourth speed driven gear 64 is meshed with the 4-6 speed drive gear 54, respectively.

  The second countershaft 36 is provided with second, fifth, sixth and seventh speed driven gears 62, 65, 66 and 67 so as to be freely rotatable, and the second speed driven gear 62 is connected to the second speed drive gear 52, The 5-speed driven gear 65 is engaged with the 5-speed drive gear 55, the 6-speed driven gear 66 is engaged with the 4-6-speed drive gear 54, and the 7-speed driven gear 67 is engaged with the 7-speed drive gear 57, respectively.

  The first countershaft 35 is provided with a reverse gear 70 so as to be freely rotatable, and the reverse gear 70 is always meshed with the small-diameter gear 62 b of the second speed driven gear 62.

  On the first countershaft 35 and the second countershaft 36, first, second, third, and fourth gear shift clutches 71 to 74 having a synchromesh function are provided. These gear shift clutches 71 to 74 are connected to the TCU 23. It is selectively operated by a shift control unit.

  The first gear shift clutch 71 is provided on the first countershaft 35 and is disposed between the synchro gear portion of the first speed driven gear 61 and the synchro gear portion of the third speed driven gear 63. By sliding the sleeve of the first gear shift clutch 71 in the axial direction, one of the first-speed driven gear 61 and the third-speed driven gear 63 and the first countershaft 35 are connected so as not to rotate relative to each other. The gears 61 and 63 are configured to be in a neutral state where they are not connected.

  Similarly, the second gear shift clutch 72 provided on the first countershaft 35 is disposed between the synchro gear portion of the 4-speed driven gear 64 and the synchro gear portion of the reverse gear 70, and the second gear shift clutch. By sliding the sleeve 72 in the axial direction, one of the fourth speed driven gear 64 and the reverse gear 70 and the first countershaft 35 are connected so as not to be relatively rotatable. The third gear shift clutch 73 provided on the second countershaft 36 is disposed between the synchro gear portion of the seventh-speed driven gear 67 and the synchro gear portion of the fifth-speed driven gear 65. By sliding the sleeve in the axial direction, one of the seventh speed driven gear 67 and the fifth speed driven gear 65 and the second countershaft 36 are connected so as not to be relatively rotatable. Further, the fourth gear shift clutch 74 provided on the second countershaft 36 is disposed between the synchro gear portion of the 6th speed driven gear 66 and the synchro gear portion of the 2nd speed driven gear 62, and the fourth gear shift clutch. By sliding the sleeve 74 in the axial direction, one of the sixth speed driven gear 66 and the second speed driven gear 62 and the second countershaft 36 are connected so as not to be relatively rotatable.

  The first and third gear shift clutches 71 and 73 described above constitute a first shift mechanism that shifts the rotational driving force transmitted to the first input shaft 31 to establish an odd gear, and the second and fourth gear shifts. The clutches 72 and 74 constitute a second shift mechanism that shifts the rotational driving force transmitted to the second input shaft 32 to establish an even-numbered shift stage.

  A final reduction drive gear 58 and a final reduction drive gear 59 are fixed to the first countershaft 35 and the second countershaft 36, respectively. These final reduction drive gears 58 and 59 are connected to the differential device 13 (see FIG. 1). It is always meshed with the reduction driven gear 80 on the connected shaft 33. Accordingly, the left and right front wheels 16a and 16b are driven via the final reduction drive gear 58 and the final reduction drive gear 59.

  FIG. 3 is a diagram illustrating an example of torque transmission characteristics of the clutch 20 (first and second clutches 20a and 20b), in which the horizontal axis indicates the stroke S of the clutch actuator 25, and the vertical axis indicates the transmittable clutch torque Tc. Yes. The clutch 20 is a clutch that is disengaged when the stroke S = 0, and has a characteristic that the clutch torque Tc increases as the stroke S increases.

  The relationship between the stroke S of the clutch actuator 25 and the clutch torque Tc is set in advance in the clutch 20 so as to become a characteristic diagram A1 in FIG. 3, and stored in the TCU 23 as a characteristic map, for example. When the target clutch torque Tc is determined, the stroke S required for the clutch torque Tc is calculated based on the characteristic diagram A1, and the maximum stroke Smax is larger than the required transmission torque Tr. A clutch torque Tc1 is obtained.

  However, when foreign matter is caught in the clutch 20 or the clutch actuator 25 or the clutch disk is worn more than necessary, the relationship between the stroke S and the clutch torque Tc changes as shown in the characteristic diagram A2, for example. Even when the actuator 25 is operated by the maximum stroke Smax, a state in which only a clutch torque Tc2 smaller than the necessary transmission torque Tr can be obtained occurs. In this state, the slip amount of the clutch 20 when the clutch is engaged (the rotational difference between the drive shaft 12 of the engine 11 and the input shaft 31 of the transmission 17) increases, and as shown in FIG. Ne and the input shaft rotational speed Nt cannot be rotated synchronously.

  Therefore, even if the clutch actuator 25 is stroked to a position where the maximum torque can be transmitted, the initial clutch torque Tc cannot be obtained. For this reason, the engine speed Ne and the input shaft speed Nt can be synchronized. If not, it is determined that the clutch is abnormal as will be described later.

  Note that the clutch abnormality includes cases such as the above-described foreign matter biting and clutch disk wear as well as abnormalities in the system for controlling the clutch 20 and the clutch actuator 25.

  When such a clutch abnormality occurs, as shown in FIG. 6, in order to synchronize the engine speed Ne and the input shaft speed Nt, a clutch torque Tc larger than the engine torque Te by a predetermined amount α is applied. Since the scheduled clutch torque Tc cannot be obtained even if the clutch actuator 25 is controlled, the engine speed change speed ΔNe shown in FIG. 6 fluctuates, and the engine speed Ne and the input shaft speed Nt are synchronized. Cannot rotate.

  Next, a control program for suppressing and controlling the engine torque Te when a clutch abnormality occurs will be described based on the flowchart of FIG.

  First, in step S100, it is determined whether the vehicle is starting or shifting. If the vehicle is starting or shifting (Y), the control program is returned, and if the vehicle is not starting or shifting (N), the process proceeds to step S102. In step S102, the difference between the engine rotational speed Ne and the rotational speed Nt of the input shaft 31 (the first input shaft 31a or the second input shaft 31b) is smaller than a predetermined rotational speed difference (for example, 200 rpm). It is determined whether or not.

  If the difference between the engine rotational speed Ne and the input shaft rotational speed Nt is 200 rpm (predetermined rotational speed difference) or less (Y), the clutch (first clutch 21) has hardly slipped, so the routine proceeds to step S104. Then, normal control is executed. That is, by controlling the clutch torque Tc to be + α of the engine torque Te by the clutch actuator 25, as shown by the two-dot chain line in FIG. 6, the engine rotational speed Ne is reduced and the input shaft rotational speed Nt. Is rotated synchronously.

  On the other hand, when the difference between the engine speed Ne and the input shaft speed Nt is 200 rpm or more (N), that is, the clutch torque Tc cannot absorb the engine torque Te, and the clutch 20 slips more than necessary. If yes, the process proceeds to step S106. In step S106, it is determined whether or not the clutch actuator 25 has reached the stroke end. If the clutch actuator 25 has not yet reached the stroke end (N), in step S108, to reduce the slip of the clutch 20, The clutch actuator 25 is controlled so as to increase the clutch torque Tc by a predetermined amount, and then the process proceeds to step S104.

  On the other hand, if the determination result in step S106 is Y (the clutch actuator 25 has reached the stroke end (Smax)), in step S110, an abnormality warning is given to the driver that a clutch abnormality has occurred. The Subsequently, in step S112 and subsequent steps, a fail safe process for suppressing the engine torque Te is executed.

  In other words, in step S112, a command for reducing the engine torque Te by a predetermined torque is issued to the ECU 14, and the accelerator opening and the fuel injection amount are controlled by the engine control unit 14a. Control for reducing Te by a predetermined torque is executed. Subsequently, in step S114, it is determined whether or not the difference between the engine rotational speed Ne and the input shaft rotational speed Nt is smaller than a predetermined rotational speed difference (for example, 200 rpm), and the engine rotational speed Ne and the input shaft rotational speed are determined. If the difference from Nt is not smaller than the predetermined rotation difference, the process returns to step S112 and the control for further reducing the engine torque Te by the predetermined torque is continued.

  In this way, until the difference between the engine speed Ne and the input shaft speed Nt becomes smaller than the predetermined speed difference, in other words, lower than the torque that the clutch 20 cannot transmit, and less than the torque that the clutch 20 can transmit. Until the engine torque Te is reached, control for decreasing the engine torque Te is executed, and the engine torque Te is suppressed. In step S114, if it is determined that the difference between the engine speed Ne and the input shaft speed Nt is smaller than the predetermined speed difference, the process proceeds to step S116, and the vehicle is evacuated to a safe position. The evacuation travel command to be issued is issued.

  Thus, while monitoring the slip amount of the clutch 20, the engine torque Te is gradually decreased by a predetermined amount until the slip amount of the clutch 20 becomes a predetermined value or less, so that the drive torque of the engine 11 is reduced to a necessary level. It becomes possible to reduce accurately.

  In this case, instead of suppressing the engine torque Te until the difference between the engine rotational speed Ne and the input shaft rotational speed Nt becomes smaller than the predetermined rotational speed difference in step S114, the engine torque Te is more than 50% of the output. The engine torque Te may be controlled to be suppressed until it decreases.

  Such engine torque Te suppression control makes it impossible to fully exhibit the performance of the engine 11, but the engine 20 is retracted to a safe place without causing the clutch 20 in an abnormal state to be damaged. A fail-safe function for synchronizing the rotational speed Ne with the input shaft rotational speed Nt is exhibited, and the vehicle can be driven safely.

  The above-described step S106 constitutes a clutch abnormality determination unit that determines that the clutch 20 is abnormal, and step S112 and step S114 constitute a torque suppression control unit that reduces the drive torque of the engine 11.

  Thus, in the present embodiment, the slip amount of the clutch 20 (the difference between the engine speed Ne and the input shaft speed Nt) is determined in advance even though the clutch actuator 25 has reached the stroke end. If the engine rotational speed Ne cannot be synchronized with the input shaft rotational speed Nt at the time of shifting, it is determined that the clutch is abnormal. If it is determined that the clutch is abnormal, the engine speed Ne can be obtained without damaging the clutch 20 by fail-safe that suppresses the engine torque Te until the slip amount of the clutch 20 becomes smaller than a predetermined value. The input shaft rotation speed Nt can be rotated synchronously, and the vehicle can travel safely.

  FIG. 5 shows a modification of the present invention. The difference from the above-described embodiment is that the engine torque Te when the clutch is abnormal is calculated based on the engine speed change speed ΔNe (see FIG. 6). This is to suppress even the transmittable torque.

  That is, when the clutch is normal, as shown in the characteristic diagram A1 of FIG. 3, if the stroke of the clutch actuator 25 detected by the stroke sensor 26 is, for example, S1, the clutch torque Tc should be the torque Tca. It is. However, when the clutch is abnormal, the clutch torque Tc is, for example, Tcb smaller than the torque Tc1 although the stroke of the clutch actuator 25 is S1.

  Therefore, from the relational expression “Tc−Te = Ie · ΔNe” between the clutch torque Tc and the engine torque Te (where Ie is the inertia torque of the engine 11 and ΔNe is the engine speed change speed obtained by differentiating the engine speed). The actual clutch torque Tc is calculated based on the engine speed change speed ΔNe during clutch operation (Tc = Ie · ΔNe + Te). Assuming that the calculated clutch torque Tc is the torque Tcb as shown in FIG. 3, by obtaining the difference between the theoretical torque Tca and the actual Tcb, the characteristic diagram of the clutch 20 becomes A1 in FIG. From FIG. 5, it can be seen that the distance is changed to A2 translated in the direction of the arrow by the Sa amount.

  As a result, the maximum clutch torque at the maximum stroke Smax, that is, the transmittable torque Tc2 that can be transmitted by the clutch 20 can be calculated based on the characteristic diagram A2. Therefore, by suppressing the engine torque Te to be less than the transmittable torque Tc2 calculated based on the engine speed change speed ΔNe, it is possible to prevent the clutch 20 from being damaged as described in the above embodiment. become.

  Specifically, as shown in the flowchart of FIG. 5, when a clutch abnormality is warned in step S200, then, in step S202, as described above, based on the engine speed change speed ΔNe, the clutch 20 is disengaged. Transmittable transmittable torque Tc2 is calculated, and in subsequent step S204, the engine torque Te is controlled to be less than the calculated transmittable torque Tc2. Thereafter, in step S206, a retreat travel command for retreating the vehicle to a safe position is issued.

  According to the above-described modification, the transmittable torque Tc2 that can be transmitted by the clutch 20 is calculated based on the rotational speed change speed ΔNe of the engine 11 when the clutch is abnormal, and the engine torque Te of the engine 11 is calculated up to the transmittable torque Tc2. As a result, the engine 11 can be quickly controlled to the required engine torque Te.

  In the above-described embodiment, the automatic transmission 10 is applied to a dual clutch automatic transmission (DCT), so that the dual clutch 20 (the first and second clutches 20a and 20b) can be appropriately handled when an abnormality occurs. However, the automatic transmission 10 is not limited to a dual-clutch automatic transmission, and can be applied to an automatically controlled manual transmission (AMT). Moreover, it can also be applied to a transmission in which only the clutch operation of a conventional manual transmission is automated.

  In the embodiment, the automatic transmission 10 applied to an FF type vehicle has been described as an example. However, the automatic transmission 10 may be mounted on an FR type (front engine / rear drive) type vehicle. .

  Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various modifications can be made without departing from the spirit of the present invention described in the claims. Of course there is.

  An automatic transmission according to the present invention is controlled by a transmission that shifts the rotation of an input shaft rotated by a drive shaft of a prime mover to a plurality of speed ratios and transmits the transmission to a drive wheel of a vehicle, and a clutch actuator. It is suitable for use in a vehicle having a clutch that engages and disengages the drive shaft and the input shaft of the transmission.

DESCRIPTION OF SYMBOLS 10 ... Automatic transmission, 11 ... Motor | power_engine (engine), 16a, 16b ... Drive wheel (right-and-left front wheel), 17 ... Transmission, 20 ... Clutch, 25 ... Clutch actuator, 31 ... Input shaft, S106 ... Clutch abnormality judgment part, S112, S114 ... Torque suppression control unit, Te ... engine torque, Tc ... clutch torque, Ne ... engine speed, Nt ... input shaft speed.

Claims (5)

A prime mover mounted on the vehicle,
A transmission for shifting the rotation of the input shaft rotated by the drive shaft of the prime mover to a plurality of speed ratios and transmitting it to the drive wheels of the vehicle;
A clutch for engaging and disengaging the drive shaft of the prime mover and the input shaft of the transmission;
A clutch actuator for controlling the clutch torque of the clutch;
A clutch abnormality determining unit that determines that the clutch is abnormal when the rotation of the drive shaft of the prime mover and the rotation of the input shaft of the transmission cannot be synchronized when the clutch actuator is in a position where maximum torque can be transmitted; ,
A torque suppression control unit that reduces the driving torque of the prime mover when the clutch abnormality determination unit determines that the clutch is abnormal;
An automatic transmission comprising:   2. The automatic transmission according to claim 1, wherein the torque suppression control unit reduces the driving torque of the prime mover to a torque lower than a torque that the clutch cannot transmit and lower than a torque that the clutch can transmit.   3. The automatic transmission according to claim 1, wherein the torque suppression control unit gradually decreases the driving torque of the prime mover by a predetermined amount until a slip amount of the clutch becomes a predetermined amount or less.   3. The transmittable torque calculation according to claim 1, wherein when the clutch abnormality determining unit determines that the clutch is abnormal, a transmittable torque that can be transmitted by the clutch is calculated based on a speed change speed of the prime mover. An automatic transmission that reduces the driving torque of the prime mover to less than the transmittable torque calculated by the transmittable torque calculator by the torque suppression control unit. 5. The clutch according to claim 1, wherein the clutch transmits a driving torque of the prime mover to a first input shaft connected to an odd-numbered shift stage and an even-numbered shift stage. An automatic transmission configured by a dual clutch including a second clutch that transmits to a second input shaft to be connected.

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