JP4436381B2 - Automatic transmission - Google Patents

Description

  The present invention relates to a failure part specifying control when a failure occurs in a friction element of a stepped automatic transmission.

  The stepped automatic transmission has a planetary gear mechanism and a plurality of friction elements, and switches the shift stage by switching the engagement state of each friction element so as to achieve a desired shift stage.

  In such an automatic transmission, when a release failure or a fastening failure occurs in a friction element, it is known to perform control for specifying the failed friction element in order to ensure traveling performance.

For example, characteristic data when a friction element has failed is stored in advance for each shift stage, and the friction element that has failed based on the stored data and the actual gear ratio, and whether it is a release failure or a fastening failure. A technique for specifying a failure mode is disclosed in Patent Document 1.
JP-A-11-280886

  In the conventional technique, when a friction element abnormality is determined, a gear ratio other than the gear stage in which the gear ratio abnormality has occurred is sequentially experienced while fail-safe is executed, and the gear ratio at each gear stage is The failed friction element is specified based on the combination of the abnormality and the normality / abnormality of the lockup when the lockup control is executed. Therefore, it takes a lot of time to identify the faulty part, and the traveling performance is deteriorated accordingly, and there is a possibility that an interlock or a neutral abnormality is further generated.

  It is an object of the present invention to identify a faulty part in a short time after a fault occurs and to suppress deterioration in running performance as much as possible.

The present invention provides an automatic transmission that includes a planetary gear and a plurality of friction elements, achieves a command shift stage by switching the engagement and release states of the plurality of friction elements, and includes a plurality of shift stages as the command shift stage. Detecting means for detecting whether a release failure that cannot be engaged even when a fastening command is output or a fastening failure that cannot be released despite a release command being generated has occurred in the friction element And when the occurrence of a failure is detected by the failure detection means, the failure part specifying control means for starting the control for specifying the failed friction element, and the faulty friction element being specified by the failure part specifying control means are specified. A limp home control means for determining a usable gear position based on the friction element and performing a gear shift control using only the usable gear speed, and a vehicle operating state. Failure identification prohibition determining means for determining whether or not it is prohibited to specify a friction element that has failed by specifying the failure part, and the failure part specifying control means has one of a plurality of shift stages as a command shift stage. Control is performed so as to identify the failed friction element while sequentially shifting the selected shift stage, and when it is determined that the identification of the failed friction element is prohibited, the failed friction element is Control is performed to specify the failed friction element while sequentially shifting the shift speed from the command shift speed at the time of stopping specifying the failed friction element when the prohibition is canceled The limp home control means is selected when the failed friction element cannot be identified even when the command gear stage is shifted to all of the gear stages selected by the failure part identification control means. Performing shift control using only the gear position has.
Further, the present invention provides an automatic transmission that includes a planetary gear and a plurality of friction elements, achieves a command shift stage by switching the engagement and release states of the plurality of friction elements, and includes a plurality of shift stages as the command shift stage. In the machine, failure detection that detects whether there is a release failure that cannot be engaged even when a fastening command is output or a fastening failure that cannot be released even if a release command is output. When the occurrence of a failure is detected by the means, the failure detection means, a failure part specifying control means for starting control for specifying the failed friction element, and a faulty friction element specified by the failure part specifying control means are specified. It is to determine the available shift stage on the basis of the friction element, and the limp home control means for performing shift control using only the usable gear position, the shift lever And a lever position detecting means for detecting the work position, the failure site specific control means, as instructed speed, select a portion of the gear of the plurality of shift speeds, while sequentially shifts the selected gear When control is performed to identify the defective friction element, and it is detected that the operation position of the shift lever is outside the forward travel range, the identification of the defective friction element is stopped and the operation position of the shift lever is changed to the forward travel range. When returning, the command shift stage is sequentially shifted from the first shift stage of the selected one or more shift stages, and control is performed so as to specify the failed friction element. If the failed friction element cannot be identified even if the command shift stage is shifted to all the selected shift stages by means, the shift control is performed using only the selected shift stage.

According to the present invention, when a failure of the friction element is detected, a part of the plurality of shift stages is selected as the command shift stage, and the failed friction element is selected while sequentially shifting the selected shift stage. When the specified friction control element is used and the failed friction element cannot be identified even after shifting to all the selected shift speeds, the shift control is performed using only the selected shift speed. Can be ensured to some extent, it is not necessary to experience all the gears in order to identify the failed friction element, and limp home control can be started earlier, so that deterioration in running performance can be minimized.
In addition, when it is determined that the identification of the defective friction element is prohibited, the command shift at the time when the identification of the defective friction element is stopped when the identification of the defective friction element is stopped when the prohibition is canceled. Since the control is performed so that the failed friction element is identified while sequentially shifting from the gear position to the gear position, the identification of the friction element is temporarily prohibited. Therefore, it is possible to identify a friction element that has failed earlier.
Furthermore, when it is detected that the shift lever operation position is outside the forward travel range, the identification of the defective friction element is stopped, and when the shift lever operation position returns to the forward travel range, the command shift stage is selected. Since the control is performed so as to sequentially identify the failed friction element from the first one of the one or more shift stages, the range position is other than the forward travel range due to a temporary failure of the friction element. Thus, when the failure is resolved, the result of the specific control of the friction element performed so far can be reset, and deterioration in running performance can be suppressed without performing excessive control.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a skeleton diagram showing the configuration of the automatic transmission according to this embodiment. The automatic transmission in the present embodiment is a stepped automatic transmission with 7 forward speeds and 1 reverse speed, and the driving force of the engine Eg is input from the input shaft Input via the torque converter TC, and the four planetary gears and 7 The rotational speed is shifted by the two friction elements and output from the output shaft Output. An oil pump OP is provided coaxially with the pump impeller of the torque converter TC, and is rotationally driven by the driving force of the engine Eg to pressurize the oil.

  In addition, an engine controller (ECU) 10 that controls the drive state of the engine Eg, an automatic transmission controller (ATCU) 20 that controls the shift state of the automatic transmission, and the hydraulic pressure of each fastening element based on the output signal of the ATCU 20 And a control valve unit (CVU) 30 for controlling the control. The ECU 10 and the ATCU 20 are connected via a CAN communication line or the like, and share sensor information and control information with each other by communication.

  Connected to the ECU 10 are an APO sensor 1 that detects the amount of accelerator pedal operation by the driver, an engine speed sensor 2 that detects the engine speed, and a throttle sensor 7 that detects the throttle opening. The ECU 10 controls the fuel injection amount and the throttle opening based on the engine rotation speed and the accelerator pedal operation amount, and controls the rotation speed and torque of the engine.

  The ATCU 20 detects the first turbine rotation speed sensor 3 that detects the rotation speed of the first carrier PC1, the second turbine rotation speed sensor 4 that detects the rotation speed of the first ring gear R1, and the shift lever operation state of the driver. Inhibitor switch 6 is connected to select an optimum command shift speed based on vehicle speed Vsp and accelerator pedal operation amount APO in the D range, and a control command for achieving the command shift speed is output to control valve unit CVU.

  Next, a transmission gear mechanism that transmits the rotation of the input shaft Input to the output shaft Output while shifting the speed will be described. In the transmission gear mechanism, a first planetary gear set GS1 and a second planetary gear set GS2 are arranged in order from the input shaft Input side to the axial output shaft Output side. Further, a plurality of clutches C1, C2, C3 and brakes B1, B2, B3, B4 are arranged as friction elements, and a plurality of one-way clutches F1, F2 are further arranged.

  The first planetary gear G1 is a single pinion planetary gear having a first sun gear S1, a first ring gear R1, and a first carrier PC1 that supports a first pinion P1 meshing with both gears S1 and R1. The second planetary gear G2 is a single pinion planetary gear having a second sun gear S2, a second ring gear R2, and a second carrier PC2 that supports a second pinion P2 that meshes with both the gears S2, R2. The third planetary gear G3 is a single pinion planetary gear having a third sun gear S3, a third ring gear R3, and a third carrier PC3 that supports a third pinion P3 that meshes with both gears S3 and R3. The fourth planetary gear G4 is a single pinion type planetary gear having a fourth sun gear S4, a fourth ring gear R4, and a fourth carrier PC4 that supports a fourth pinion P4 that meshes with both the gears S4 and R4.

  The input shaft Input is connected to the second ring gear R2, and inputs the rotational driving force from the engine Eg via the torque converter TC or the like. The output shaft Output is connected to the third carrier PC3, and transmits the output rotational driving force to the driving wheels via a final gear or the like.

  The first connecting member M1 is a member that integrally connects the first ring gear R1, the second carrier PC2, and the fourth ring gear R4. The second connecting member M2 is a member that integrally connects the third ring gear R3 and the fourth carrier PC4. The third connecting member M3 is a member that integrally connects the first sun gear S1 and the second sun gear S2.

  The first planetary gear set GS1 is composed of four rotating elements, in which the first planetary gear G1 and the second planetary gear G2 are connected by a first connecting member M1 and a third connecting member M3. The second planetary gear set GS2 is composed of five rotating elements by connecting the third planetary gear G3 and the fourth planetary gear G4 by the second connecting member M2.

  In the first planetary gear set GS1, torque is input from the input shaft Input to the second ring gear R2, and the input torque is output to the second planetary gear set GS2 via the first connecting member M1. In the second planetary gear set GS2, torque is directly input to the second connecting member M2 from the input shaft Input, and is input to the fourth ring gear R4 via the first connecting member M1, and the input torque is the third torque. The signal is output from the carrier PC3 to the output shaft Output.

  The input clutch C1 is a clutch that selectively connects and disconnects the input shaft Input and the second connecting member M2. The direct clutch C2 is a clutch that selectively connects and disconnects the fourth sun gear S4 and the fourth carrier PC4.

  The H & LR clutch C3 is a clutch that selectively connects and disconnects the third sun gear S3 and the fourth sun gear S4. A second one-way clutch F2 is disposed between the third sun gear S3 and the fourth sun gear S4. Thus, when the H & LR clutch C3 is released and the rotation speed of the fourth sun gear S4 is higher than that of the third sun gear S3, the third sun gear S3 and the fourth sun gear S4 generate independent rotation speeds. Therefore, the third planetary gear G3 and the fourth planetary gear G4 are connected via the second connecting member M2, and each planetary gear achieves an independent gear ratio.

  The front brake B1 is a brake that selectively stops the rotation of the first carrier PC1. A first one-way clutch F1 is disposed in parallel with the front brake B1. The low brake B2 is a brake that selectively stops the rotation of the third sun gear S3. The 2346 brake B3 is a brake that selectively stops the rotation of the third connecting member M3 that connects the first sun gear S1 and the second sun gear S2. The reverse brake B4 is a brake that selectively stops the rotation of the fourth carrier PC4.

  Next, the hydraulic circuit of the CVU 30 will be described with reference to FIG. FIG. 2 is a circuit diagram showing a hydraulic circuit of the CVU.

  The hydraulic circuit includes an oil pump OP as a hydraulic source driven by the engine, a manual valve MV for switching an oil passage for supplying the line pressure PL in conjunction with a driver's shift lever operation, and a predetermined line pressure. A pilot valve PV for reducing the pressure to a constant pressure is provided.

  Further, a first pressure regulating valve CV1 for regulating the engagement pressure of the low brake B2, a second pressure regulating valve CV2 for regulating the engagement pressure of the input clutch C1, a third pressure regulating valve CV3 for regulating the engagement pressure of the front brake B1, A fourth pressure regulating valve CV4 that regulates the engagement pressure of the H & RL clutch C3, a fifth pressure regulation valve CV5 that regulates the engagement pressure of the 2346 brake B3, and a sixth pressure regulation valve CV6 that regulates the engagement pressure of the direct clutch C2 are provided. .

  Further, the first switching valve SV1 that switches only one of the supply oil passages to the low brake B and the input clutch C1 and the supply oil passage for the D range pressure and the R range pressure with respect to the direct clutch C2. Of these, the second switching valve SV2 that switches only one of them to the communication state and the hydraulic pressure supplied to the reverse brake B4 are switched between the hydraulic pressure supplied from the sixth pressure regulating valve CV6 and the hydraulic pressure supplied from the R range pressure. A third switching valve SV3 and a fourth switching valve SV4 that switches the hydraulic pressure output from the sixth pressure regulating valve CV6 between the oil passage 123 and the oil passage 122 are provided.

  Further, based on a control signal from the ATCU 20, a first solenoid valve SOL1 that outputs a pressure regulating signal to the first pressure regulating valve CV1, and a second solenoid valve SOL2 that outputs a pressure regulating signal to the second pressure regulating valve CV2; The third solenoid valve SOL3 that outputs a pressure regulating signal to the third pressure regulating valve CV3, the fourth solenoid valve SOL4 that outputs the pressure regulating signal to the fourth pressure regulating valve CV4, and the pressure regulated to the fifth pressure regulating valve CV5 A fifth solenoid valve SOL5 that outputs a signal, a sixth solenoid valve SOL6 that outputs a pressure regulating signal to the sixth pressure regulating valve CV6, and a first signal that outputs a switching signal to the first switching valve SV1 and the third switching valve SV3. 7 solenoid valve SOL7.

  The discharge pressure of the oil pump OP driven by the engine is adjusted to the line pressure and then supplied to the oil passage 101 and the oil passage 102. The oil passage 101 includes an oil passage 101a connected to a manual valve MV that operates in conjunction with the driver's shift lever operation, an oil passage 101b that supplies the original pressure of the fastening pressure of the front brake B1, and an H & LR clutch C3. An oil passage 101c that supplies the original pressure of the fastening pressure is connected.

  The manual valve MV is connected to an oil passage 105 and an oil passage 106 that supplies an R range pressure selected during reverse travel, and switches between the oil passage 105 and the oil passage 106 in accordance with a shift lever operation.

  In the oil passage 105, there are an oil passage 105a that supplies the original pressure of the engagement pressure of the low brake B2, an oil passage 105b that supplies the original pressure of the engagement pressure of the input clutch C1, and an original pressure of the engagement pressure of the 2346 brake B3. The oil passage 105c to be supplied, the oil passage 105d for supplying the original pressure of the engagement pressure of the direct clutch C2, and the oil passage 105e for supplying the switching pressure of the second switching valve SV2 described later are connected.

  In the oil passage 106, an oil passage 106a that supplies the switching pressure of the second switching valve SV2, an oil passage 106b that supplies the original pressure of the engagement pressure of the direct clutch C2, and an oil passage that supplies the engagement pressure of the reverse brake B4. 106c is connected.

  An oil passage 103 for supplying pilot pressure is connected to the oil passage 102 via a pilot valve PV. The oil passage 103 has an oil passage 103a for supplying pilot pressure to the first solenoid valve SOL1, an oil passage 103b for supplying pilot pressure to the second solenoid valve SOL2, and an oil for supplying pilot pressure to the third solenoid valve SOL3. A passage 103c, an oil passage 103d for supplying pilot pressure to the fourth solenoid valve SOL4, an oil passage 103e for supplying pilot pressure to the fifth solenoid valve SOL5, and an oil passage 103f for supplying pilot pressure to the sixth solenoid valve SOL6 And an oil passage 103g for supplying pilot pressure to the seventh solenoid valve SOL7.

  Next, the operation of the transmission gear mechanism will be described with reference to FIGS. FIG. 3 is a fastening table showing a fastening state of each fastening element for each gear position. A circle indicates that the fastening element is in a fastening state, and a circle indicates that the range position where the engine brake operates is selected. It shows that the said fastening element will be in a fastening state when being done. FIG. 4 is a collinear diagram showing the rotation state of each rotary member at each shift stage.

  In the first speed, only the low brake B2 is engaged, and the first one-way clutch F1 and the second one-way clutch F2 are engaged. When the engine brake is applied, the front brake B1 and the H & LR clutch C3 are further engaged.

  Since the rotation of the first carrier PC1 is stopped by the engagement of the first one-way clutch F1, the rotation input to the second ring gear R2 from the input shaft Input is decelerated by the first planetary gear set GS1, This rotation is output from the first connecting member M1 to the fourth ring gear R4. Further, since the rotation of the third sun gear S3 and the fourth sun gear S4 is restrained by engaging the second brake F2 and engaging the second one-way clutch F2, the rotation input to the fourth ring gear R4 is It is decelerated by the second planetary gear set GS2 and output from the third carrier PC3.

  That is, as shown in the nomogram of FIG. 4, the rotation of the input shaft Input is decelerated by the first planetary gear set GS1, further decelerated by the second planetary gear set GS2, and output from the output shaft Output.

  In the second speed, the low brake B2 and the 2346 brake B3 are engaged, and the second one-way clutch F2 is engaged. Further, the H & LR clutch C3 is further engaged when the engine brake is applied.

  When the 2346 brake B3 is engaged, the rotation of the first sun gear S1 and the second sun gear S2 is stopped. Therefore, the rotation input to the second ring gear R2 from the input shaft Input is only performed by the second planetary gear G2. The speed is reduced, and this rotation is output from the first connecting member M1 to the fourth ring gear R4. Further, since the rotation of the third sun gear S3 and the fourth sun gear S4 is restrained by engaging the second brake F2 and engaging the second one-way clutch F2, the rotation input to the fourth ring gear R4 is It is decelerated by the second planetary gear set GS2 and output from the third carrier PC3.

  That is, as shown in the nomogram of FIG. 4, the rotation of the input shaft Input is decelerated by the first planetary gear set GS1, further decelerated by the second planetary gear set GS2, and output from the output shaft Output.

  In the third speed, the low brake B2, the 2346 brake B3, and the direct clutch C2 are engaged.

  When the 2346 brake B3 is engaged, the rotation of the first sun gear S1 and the second sun gear S2 is stopped. Therefore, the rotation input to the second ring gear R2 from the input shaft Input is decelerated by the second planetary gear G2. This rotation is output from the first connecting member M1 to the fourth ring gear R4. Further, as the direct clutch C2 is engaged, the fourth planetary gear G4 rotates integrally. Therefore, the fourth planetary gear G4 is involved in torque transmission but not in deceleration. Further, since the rotation of the third sun gear S3 is stopped when the low brake B2 is engaged, the third ring is rotated from the fourth carrier PC4 rotating integrally with the fourth ring gear R4 via the second connecting member M2. The rotation input to the gear R3 is decelerated by the third planetary gear G3 and output from the third carrier PC3.

  That is, as shown in the nomogram of FIG. 4, the rotation of the input shaft Input is decelerated by the first planetary gear set GS1, and further decelerated by the third planetary gear G3 of the second planetary gear set GS2, and the output shaft Output is output. Is output from.

  At the fourth speed, 2346 brake B3, direct clutch C2, and H & LR clutch C3 are engaged.

  When the 2346 brake B3 is engaged, the rotation of the first sun gear S1 and the second sun gear S2 is stopped. Therefore, the rotation input to the second ring gear R2 from the input shaft Input is only performed by the second planetary gear G2. The speed is reduced, and this rotation is output from the first connecting member M1 to the fourth ring gear R4. Since the second planetary gear set GS2 rotates as a result of engaging the direct clutch C2 and the H & LR clutch C3, the rotation input to the fourth ring gear R4 is directly output from the third carrier PC3. .

  That is, as shown in the nomogram of FIG. 4, the rotation of the input shaft Input is decelerated by the first planetary gear set GS1, and is output from the output shaft Output without being decelerated by the second planetary gear set GS2.

  In the fifth speed, the input clutch C1, the direct clutch C2, and the H & LR clutch C3 are engaged.

  As the input clutch C1 is engaged, the rotation of the input shaft Input is directly input to the second connecting member M2. Further, since the second planetary gear set GS2 rotates as a result of engaging the direct clutch C2 and the H & LR clutch C3, the rotation of the input shaft Input is directly output from the third carrier PC3.

  That is, as shown in the collinear diagram of FIG. 4, the rotation of the input shaft Input is output as it is from the output shaft Output without being decelerated by the first planetary gear set GS1 and the second planetary gear set GS2.

  In the sixth speed, the input clutch C1, the H & LR clutch C3, and the 2346 brake B3 are engaged.

  When the input clutch C1 is engaged, the rotation of the input shaft Input is input to the second ring gear and directly to the second connecting member M2. Since the rotation of the first sun gear S1 and the second sun gear S2 is stopped when the 2346 brake B3 is engaged, the rotation of the input shaft Input is decelerated by the second planetary gear G2, and the first connecting member M1 Output to the fourth ring gear R4.

  In addition, since the third sun gear S3 and the fourth sun gear S4 rotate as a result of the H & LR clutch C3 being engaged, the second planetary gear set GS2 rotates the fourth ring gear R4 and the second connecting member M2. The rotation defined by the rotation is output from the third carrier PC3.

  That is, as shown in the nomogram of FIG. 4, a part of the rotation of the input shaft Input is decelerated in the first planetary gear set GS1 and accelerated in the second planetary gear set GS2, and output from the output shaft Output. Is done.

  In the seventh speed, the input clutch C1, the H & LR clutch C3, and the front brake B1 are engaged, and the first one-way clutch F1 is engaged.

  When the input clutch C1 is engaged, the rotation of the input shaft Input is input to the second ring gear R2 and directly to the second connecting member M2. Further, since the rotation of the first carrier PC1 is stopped by fastening the front brake B1, the rotation of the input shaft Input is decelerated by the first planetary gear set GS1, and this rotation is transmitted from the first connecting member M1. It is output to the 4-ring gear R4.

  In addition, since the third sun gear S3 and the fourth sun gear S4 rotate as a result of the H & LR clutch C3 being engaged, the second planetary gear set GS2 rotates the fourth ring gear R4 and the second connecting member M2. The rotation defined by the rotation is output from the third carrier PC3.

  That is, as shown in the nomogram of FIG. 4, a part of the rotation of the input shaft Input is decelerated in the first planetary gear set GS1 and accelerated in the second planetary gear set GS2, and output from the output shaft Output. Is done.

  At the reverse speed, the H & LR clutch C3, the front brake B1, and the reverse brake B4 are engaged.

  Since the rotation of the first carrier PC1 is stopped by engaging the front brake B1, the rotation of the input shaft Input is decelerated by the first planetary gear set GS1, and this rotation is transmitted from the first connecting member M1 to the fourth ring. It is output to the gear R4.

  Further, when the H & LR clutch C3 is engaged, the third sun gear S3 and the fourth sun gear S4 rotate integrally, and when the reverse brake B4 is engaged, the rotation of the second connecting member M2 is stopped. In the second planetary gear set GS2, the rotation of the fourth ring gear R4 is transmitted to the fourth sun gear S4, the third sun gear S3, and the third carrier PC3 while being inverted, and is output from the third carrier PC3.

  That is, as shown in the nomogram of FIG. 4, the rotation of the input shaft Input is decelerated in the first planetary gear set GS1, reversed in the second planetary gear set GS2, and output from the output shaft Output.

  The automatic transmission is configured as described above, and is switched to a desired gear position between 1st speed and 7th speed according to a shift line set based on the vehicle speed and the throttle opening. At this time, if any one of the friction elements breaks down, the desired shift speed cannot be achieved, and the running performance deteriorates. Therefore, the control performed in the ATCU 20 when the friction element fails will be described with reference to the flowchart of FIG.

  FIG. 5 is a flowchart showing the control of the automatic transmission according to this embodiment. This control specifies the failed friction element when any of the friction elements of the automatic transmission fails, and specifies whether the failure is a release failure or a fastening failure. Accordingly, limp home control is performed. A release failure is a failure in which the friction element that outputs the engagement command remains released without being completely engaged, and an engagement failure is a failure in which the friction element that outputs the release command remains engaged without being released. It is.

  In step S1 (failure detection means), it is determined whether any one of an interlock failure, a gear ratio abnormality, a neutral abnormality, and an overspeed is detected. If any abnormality is detected, the process proceeds to step S2, and if none is detected, step S1 is executed again.

  The interlock failure refers to a state in which the rotation of the input shaft Input or the output shaft Output of the transmission is locked when an unnecessary friction element that is not commanded is fastened with respect to the friction element fastening command. It is detected that an interlock failure has occurred when the deceleration of the vehicle during non-operation exceeds a predetermined value.

  Neutral abnormality refers to a state in which the power of the input shaft is not transmitted to the output shaft because part of the commanded friction element is not engaged with the friction element engagement command. On the other hand, when the actual gear ratio is greater than a predetermined value, it is detected that a neutral abnormality has occurred.

  The gear ratio abnormality refers to a state where the engagement capacity of the friction element is insufficient with respect to the engagement command of the friction element, or a state where an excess friction element not commanded has an engagement capacity. When the actual gear ratio deviates from the gear ratio by a predetermined value or more, and it is not determined that the neutral abnormality is present, it is detected that the gear ratio abnormality has occurred.

  Excessive rotation means a state in which the rotational speeds of the rotating members other than the input shaft Input and the output shaft Output are increased to a rotational speed that cannot be obtained when the command gear stage is normally achieved. The rotation speed of the member is detected directly or indirectly, and when this rotation speed exceeds a predetermined value, it is detected that over-rotation has occurred.

  In step S2, provisional limp home is performed according to the failure or abnormality detected in step S1. The temporary limp home is performed, for example, by fixing the gear stage to a gear stage other than the gear stage when a failure or abnormality is detected.

  In step S3, it is determined whether the vehicle has stopped. If the vehicle has stopped, it will progress to step S4, and if it has not stopped, step S3 will be performed again. Whether or not the vehicle has stopped is determined by whether or not the vehicle speed has become a predetermined vehicle speed (for example, 5 km / h) or less.

  In step S4 (failure part specifying control means), it is determined whether or not the failure detected in step S1 is a neutral abnormality and the command shift stage at the time of detection is the first to third speeds. If the condition is satisfied, the process proceeds to step S5 (limp home control means), and shift control is performed using the fourth, fifth and sixth speeds as the main limp home. If there is no neutral abnormality or if the command shift speed is not 1st to 3rd, the process proceeds to step S6.

  If the detected failure is a neutral abnormality and the command gear position at the time of detection is 1st to 3rd gear, it is estimated that a release failure of the low brake B2 that is always engaged in the 1st to 3rd gears has occurred. Therefore, the shift control is performed using the fourth, fifth and sixth gears while avoiding the first to third gears using the low brake B2.

  In the control described below, the command shift stage is experienced from the first speed to the third speed, and the search control is performed so as to identify the failure portion depending on whether or not the actual shift stage shows a normal value with respect to the command shift stage. .

  In step S6, the command shift speed is set to the first speed. Here, the command shift speed is set to the first speed regardless of the vehicle speed and the throttle opening. Similarly, in steps S17 and S28, which will be described later, the second and third speeds are respectively fixed. That is, it is prohibited to shift up or down based on the vehicle speed or the throttle opening during the execution of the steps after this step.

  In step S7, whether or not the signals of the output shaft rotational speed sensor 5, the first turbine rotational speed sensor 3, the second turbine rotational speed sensor 4, the throttle sensor 7, the engine rotational speed sensor 2 and the inhibitor switch 6 are normal. Determine. If the signal is normal, the process proceeds to step S9. If the signal is abnormal, the process proceeds to step S8 to fix the command shift speed to the first speed, and thereafter, the vehicle continues to travel at the first speed.

  Here, when the command shift speed is the first speed, an engagement command is issued to the low brake B2, and in this state, even if other friction elements are engaged and failed, the actual gear ratio will only be other than the gear ratio corresponding to the first speed. Thus, there will be no further malfunction such as interlock. Therefore, in situations where the signal is abnormal and the faulty part cannot be accurately identified, fixing the command gear to the first speed will cause incorrect limp home, resulting in poor running performance and frictional elements. Prevent excessive wear from occurring.

  In step S9 (failure identification prohibition judging means), whether the vehicle speed Vsp is higher than a predetermined speed, whether the rotational speed TbnREV of the turbine runner is higher than a predetermined speed, and whether the throttle valve opening Tvo is larger than the predetermined opening. It is determined whether or not a value Ne−Nt obtained by subtracting the rotational speed of the turbine runner from the engine rotational speed is greater than a predetermined value. If all the conditions are satisfied, the process proceeds to step S10, and if none is satisfied, the process returns to step S7.

  Since the gear ratio cannot be accurately detected unless the output shaft Output of the transmission is rotated, the predetermined speed is set to a value that can determine that the vehicle speed is such that the gear ratio can be accurately detected. . Similarly, since the gear ratio cannot be accurately detected unless the input shaft Input of the transmission is rotating, it is determined that the turbine runner is rotating to such an extent that the predetermined rotation can accurately detect the gear ratio. It is set to a value that allows it. Further, the predetermined opening and the predetermined value are set so that it can be determined that the driving force of the engine Eg is transmitted from the input shaft Input of the transmission to the output shaft Output, that is, the drive state instead of the coast state. Is done.

  In step S10 (lever position detection means), it is determined whether or not the range signal is other than P, R, and N. If the range signal is other than P, R, N, that is, if it is a forward travel range, the process proceeds to step S11, and if the range signal is P, R, N, the process returns to step S7.

  The friction element often causes a fastening failure due to a valve stick by causing contamination or the like between the spool of the pressure regulating valve that regulates the hydraulic pressure of the friction element and the bore of the valve body. When such a failure occurs, if the range is changed from the forward travel range to the P, R, or N range, the hydraulic pressure is discharged from the manual port. As a result, the spool may come off from the valve body and the fastening failure may be eliminated. Therefore, when the range is changed from the forward travel range to the P, R, or N range during the execution of this control, the previous data is reset and the control is performed again.

  In step S11, an actual gear ratio is detected. The actual gear ratio is calculated by dividing the rotational speed of the output shaft Output from the rotational speed of the input shaft Input of the transmission.

  In step S12, it is determined whether or not a predetermined time has elapsed since the command gear is set to the first speed. The predetermined time is a time sufficient to exclude the case where the condition of step S9 is temporarily satisfied, and is set to 2 s, for example.

  In step S13 (failure part specifying control means), it is determined whether or not the actual gear ratio is equivalent to 1.5 speed. If the actual gear ratio is equivalent to 1.5 speed, the process proceeds to step S14 (Limp home control means), and gear shift control is performed using the third, fourth, and fifth speeds as the main limp home, and the actual gear ratio is 1.5 speed. If not, the process proceeds to step S15. Here, the actual gear ratio corresponds to the 1.5th speed when the low brake B2, the first one-way clutch F1, and the direct clutch C2 are engaged according to the alignment chart of FIG. Since the current command shift speed is the first speed and the engagement command is output only to the low brake B2, it can be determined that the direct clutch C2 is in failure. Therefore, the shift control is performed using only the third, fourth, and fifth gear speeds for engaging the direct clutch C2.

  In step S15 (failure part specifying control means), it is determined whether or not the actual gear ratio is equivalent to the second speed. If the actual gear ratio is equivalent to the second speed, the process proceeds to step S16 (Limp home control means), and the second, third, and fourth speeds are used as the main limp home, and if the actual gear ratio is other than the second speed, the step is performed. Proceed to S17. Here, the actual gear ratio is equivalent to the second speed even though the command shift speed is the first speed. The comparison of the first speed and the second speed in the engagement table of FIG. Since this is the case, the shift control is performed using only the second, third, and fourth speeds among the shift speeds at which the 2346 brake is engaged.

  In step S17, the command shift speed is set to the second speed.

  In step S18, whether or not the signals of the output shaft rotational speed sensor 5, the first turbine rotational speed sensor 3, the second turbine rotational speed sensor 4, the throttle sensor 7, the engine rotational speed sensor 2, and the inhibitor switch 6 are normal. Determine. If the signal is normal, the process proceeds to step S20, and if the signal is abnormal, the process proceeds to step S19 to fix the command shift speed to the first speed.

  In step S20 (failure identification prohibition judging means), whether the vehicle speed Vsp is higher than a predetermined speed, whether the turbine runner rotation speed TbnREV is higher than a predetermined rotation, or whether the throttle valve opening Tvo is larger than a predetermined opening. It is determined whether or not a value Ne−Nt obtained by subtracting the rotational speed of the turbine runner from the engine rotational speed is greater than a predetermined value. If all the conditions are satisfied, the process proceeds to step S21, and if none is satisfied, the process returns to step S18.

  In step S21 (lever position detecting means), it is determined whether or not the range signal is other than P, R, and N. If the range signal is other than P, R, N, that is, if it is the forward travel range, the process proceeds to step S22, and if the range signal is P, R, N, the process returns to step S6.

  As described in step S10 above, the engagement failure of the friction element may be eliminated by changing the range from the forward travel range to the P, R, or N range. If the following control is continued while maintaining the result obtained by the failure part specifying control in steps S6 to S16 performed as the first speed, the running performance may deteriorate due to excessive control. Therefore, when the range is changed from the forward travel range to the P, R, or N range, the command shift stage is set to the 1st speed again and the failure part specifying control is re-executed from the beginning.

  In step S22, the actual gear ratio is detected.

  In step S23, it is determined whether or not a predetermined time has elapsed since the command shift speed was set to the second speed. If the predetermined time has elapsed, the process proceeds to step S24, and if the predetermined time has not elapsed, the process returns to step S18.

  In step S24 (failure part specifying control means), it is determined whether or not the actual gear ratio is equivalent to the first speed. If the actual gear ratio is equivalent to the 1st speed, the process proceeds to step S25 (Limp home control means) to perform the shift control using the 1st, 5th and 7th speeds as the main limp home, and if the actual gear ratio is other than the 1st speed. Proceed to step S26. Here, the fact that the actual gear ratio is equivalent to the first speed even though the command gear stage is the second speed is that the 2346 brake is disengaged when comparing the first speed and the second speed in the engagement table of FIG. Since this is the case, the shift control is performed using only the first, fifth and seventh speeds, which are the gear stages for releasing the 2346 brake.

  In step S26 (failure part specifying control means), it is determined whether or not the actual gear ratio is a gear ratio (ILK) equivalent to an interlock. If the actual gear ratio is a gear ratio equivalent to the interlock, the process proceeds to step S27 (Limp home control means), and shifts are performed using 1, 2.5, and 7th speeds as the main limp home, and the actual gear ratio is interlocked. If the gear ratio is not an appropriate one, the process proceeds to step S28. Of the interlock failures, the gear ratio is small when the input shaft is locked, and the gear ratio is large when the output shaft is locked. Therefore, when the gear ratio is larger than the gear ratio equivalent to the first speed or equivalent to the second speed. When the gear ratio is smaller than that, it is determined that the gear ratio is equivalent to the interlock.

  When the command shift speed is the second speed, an engagement command is output to the low brake B2 and the 2346 brake B3 as shown in the collinear diagram of FIG. Since the rotation of the carrier PC1 is stopped, an interlock failure occurs in which the input shaft Input is locked. Therefore, the shift control is performed using only the first, second, and fifth gears that are the gears for engaging the front brake B1.

  In step S28, the command shift speed is set to the third speed.

  In step S29, whether or not the signals of the output shaft rotational speed sensor 5, the first turbine rotational speed sensor 3, the second turbine rotational speed sensor 4, the throttle sensor 7, the engine rotational speed sensor 2 and the inhibitor switch 6 are normal. Determine. If the signal is normal, the process proceeds to step S31, and if the signal is abnormal, the process proceeds to step S30 to fix the command shift speed to the first speed.

  In step S31 (failure identification prohibition judging means), whether the vehicle speed Vsp is higher than a predetermined speed, whether the rotational speed TbnREV of the turbine runner is higher than a predetermined speed, or whether the throttle valve opening Tvo is larger than the predetermined opening. It is determined whether or not a value Ne−Nt obtained by subtracting the rotational speed of the turbine runner from the engine rotational speed is greater than a predetermined value. If all the conditions are satisfied, the process proceeds to step S32, and if none is satisfied, the process returns to step S29.

  In step S32 (lever position detection means), it is determined whether or not the range signal is other than P, R, and N. If the range signal is other than P, R, N, that is, if it is the forward travel range, the process proceeds to step S33, and if the range signal is P, R, N, the process returns to step S6.

  In step S33, the actual gear ratio is detected.

  In step S34, it is determined whether or not a predetermined time has elapsed since the command gear is set to the third speed. If the predetermined time has elapsed, the process proceeds to step S35, and if the predetermined time has not elapsed, the process returns to step S29.

  In step S35 (failure part specifying control means), it is determined whether or not the actual gear ratio is equivalent to the second speed. If the actual gear ratio is equivalent to the 2nd speed, the process proceeds to step S36 (Limp home control means) to perform the speed change control using the 1st and 2nd speeds as the main limp home. Proceed to Here, the actual gear ratio is equivalent to the second gear even though the command gear is the third gear. The comparison between the second gear and the third gear in the engagement table of FIG. Therefore, the shift control is performed using only the first and second speeds among the shift speeds at which the direct clutch C2 is released.

  In step S37 (failure part specifying control means), it is determined whether or not the actual gear ratio is a gear ratio equivalent to an interlock. If the actual gear ratio is a gear ratio equivalent to the interlock, the process proceeds to step S38 (Limp home control means), and gear shift is performed using the fourth, fifth, sixth and seventh speeds as the main limp home, and the actual gear ratio is interlocked. If the gear ratio is not an appropriate one, the process proceeds to step S39.

  When the command speed is 3rd speed, the engagement command is output to the direct clutch C2, the low brake B2, and the 2346 brake B3 as shown in the collinear diagram of FIG. 8, but when the H & LR clutch C3 fails in this state Since the rotation of the fourth carrier PC4 is stopped, an interlock failure occurs in which the output shaft Output is locked. Therefore, the shift control is performed using only the fourth, fifth, sixth and seventh speeds, which are the shift speeds at which the H & LR clutch C3 is engaged.

  In step S39 (limp home control means), the speed is changed using only the first, second and third speeds as the main limp home. The failure was estimated from the actual gear ratio detected at each command shift stage while experiencing the first to third speeds, but this step is executed if none of the conditions correspond, so it is estimated Possible failures include engagement failure and release failure of the input clutch C1, and release failure of the H & LR clutch C3. Therefore, shift control is performed using the first, second, and third speeds that do not affect any of the above failures.

  As described above, in the present embodiment, when a failure of the friction element is detected, control is performed to identify the failed friction element while sequentially shifting the command shift speed from the first speed to the third speed, and from the first speed to the third speed. If the failed friction element cannot be specified even after shifting to the first gear, the gear shift control is performed using the first gear to the third gear as the limp home control, so that a certain degree of traveling performance can be secured. In this case, it is not necessary to experience all the shift speeds in order to identify the failed friction element, and the limp home control can be started earlier, so that deterioration in running performance can be minimized. Correspondence).

In addition, because the failed friction element is identified based on the command shift speed and the actual shift speed estimated from the actual gear ratio, it is determined for all shift speeds that the gear ratio is deviated from the command shift speed. Therefore, it is possible to identify the friction element that failed early (corresponding to claim 3 ).

Further, when the failed friction element can be identified, the limp home control is performed without shifting to the next selected shift stage. Therefore, after the failed friction element can be identified, the command shift stage is sequentially shifted. Unnecessary control can be omitted, and deterioration in running performance can be further suppressed (corresponding to claim 4 ).

Furthermore, since the command shift stage is sequentially shifted every predetermined time, it is possible to shift the shift stage more reliably regardless of the running state as compared with the case where a shift instruction is issued based on the vehicle speed and the throttle opening, and earlier. The friction element can be specified. In particular, in the event of a failure, the driver does not depress the accelerator pedal very much, so if the command shift stage is shifted depending on the vehicle speed and throttle opening, it will take a lot of time to switch the command shift stage. According to the form, the friction element can be identified earlier (corresponding to claim 5 ).

Furthermore, since the command shift stage is sequentially shifted every predetermined time and downshift is prohibited, the command shift stage can be surely shifted to the selected shift stage, and the malfunctioning element identified early. (Corresponding to claim 6 ).

Further, whether or not the vehicle speed Vsp is higher than a predetermined speed, whether or not the turbine runner rotational speed TbnREV is higher than a predetermined speed, whether or not the throttle valve opening Tvo is larger than a predetermined opening, When the condition Ne-Nt obtained by subtracting the rotational speed of N is not greater than a predetermined value, the specification of the friction element is stopped. When the above condition is satisfied, the specification of the friction element is stopped. Since the identification of the friction element is resumed from the commanded gear stage when it was stopped, if the condition is satisfied again after the above condition is temporarily not satisfied, the commanded gear stage that has already been experienced is not experienced again, and more It is possible to identify the friction element that failed early (corresponding to claim 1 ).

When it is detected that the range signal is P, R, N, the identification of the failed friction element is stopped, and when the range signal is other than P, R, N, the command shift speed is returned to the first speed first. Since the specific control of the failed friction element is redone, the temporary failure of the friction element, and when the failure is resolved by changing the range position from the forward travel range to the P, R, N range, The result of the specific control of the friction element performed so far can be reset, and the deterioration of running performance can be suppressed without performing excessive control (corresponding to claim 2 ).

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea.

It is a skeleton figure which shows the structure of the automatic transmission in this embodiment. It is a circuit diagram showing the hydraulic circuit of CVU. It is a fastening table | surface which shows the fastening state of each fastening element for every gear stage. It is an alignment chart which shows the rotation state of each rotation member in each gear stage. It is a flowchart which shows control of the automatic transmission in this embodiment. It is an alignment chart which shows the rotation state of each rotating member in 1st speed and 1.5 speed. It is a collinear diagram which shows the rotation state of each rotation member in 2nd speed. It is a collinear diagram which shows the rotation state of each rotation member in 3rd speed.

Explanation of symbols

G1 1st planetary gear G2 2nd planetary gear G3 3rd planetary gear G4 4th planetary gear B1 Front brake B2 Low brake B3 2346 Brake B4 Reverse brake C1 Input clutch C2 Direct clutch C3 H & LR clutch 20 ATCU

Claims (6)

In an automatic transmission that includes a planetary gear and a plurality of friction elements, achieves a command shift stage by switching a fastening and releasing state of the plurality of friction elements, and includes a plurality of shift stages as the command shift stage,
In the friction element, a failure detection means for detecting whether a release failure that cannot be engaged even when a fastening command is output or a fastening failure that cannot be released despite a release command being output has occurred. ,
When detecting the occurrence of a failure by the failure detection means, a failure part specifying control means for starting control for specifying a failed friction element;
A limp home that determines a usable gear stage based on the identified friction element when the malfunctioning friction element is identified by the malfunctioning part identifying control means, and performs gearshift control using only the usable gear stage Control means;
Failure identification prohibition determining means for determining whether to prohibit the identification of a friction element that has failed due to the failure site identification based on the driving state of the vehicle,
The failure part specifying control means performs control so that a part of the plurality of shift stages is selected as the command shift stage, and the failed friction element is specified while sequentially shifting the selected shift stage. When it is determined that the identification of the failed friction element is prohibited, the command shift stage when the identification of the failed friction element is stopped when the identification of the failed friction element is stopped when the prohibition is canceled Control to identify the failed friction element while sequentially shifting the gear position from
The limp home control means, if the failed friction element cannot be identified even when the command shift speed is shifted to all of the selected speeds by the failure part specifying control means, the selected speed change control means. An automatic transmission characterized by performing shift control using only a stage. In an automatic transmission that includes a planetary gear and a plurality of friction elements, achieves a command shift stage by switching a fastening and releasing state of the plurality of friction elements, and includes a plurality of shift stages as the command shift stage,
In the friction element, a failure detection means for detecting whether a release failure that cannot be engaged even when a fastening command is output or a fastening failure that cannot be released despite a release command being output has occurred. ,
When detecting the occurrence of a failure by the failure detection means, a failure part specifying control means for starting control for specifying a failed friction element;
A limp home that determines a usable gear stage based on the identified friction element when the malfunctioning friction element is identified by the malfunctioning part identifying control means, and performs gearshift control using only the usable gear stage Control means;
Lever position detecting means for detecting the operation position of the shift lever,
The failure part specifying control means performs control so that a part of the plurality of shift stages is selected as the command shift stage, and the failed friction element is specified while sequentially shifting the selected shift stage. When the operation position of the shift lever is detected to be outside the forward travel range, the identification of the defective friction element is stopped, and when the operation position of the shift lever returns to the forward travel range, the command shift speed is changed. Sequentially shifting from the first gear of the selected one or more gears to control to identify the failed friction element;
The limp home control means, if the failed friction element is not specified even if the command gear stage is shifted to all of the selected gear stages by the failure part specifying control means, An automatic transmission characterized by performing shift control using only a stage. The failure part specifying control means specifies a failed friction element on the basis of a command shift speed and an actual shift speed estimated from an actually achieved gear ratio. Automatic transmission as described. 4. The failure part specifying control unit, when a failed friction element can be specified, shifts to the limp home control unit without shifting to the next selected gear stage. The automatic transmission according to any one of the above. 5. The automatic transmission according to claim 1, wherein the failure part specifying control unit sequentially shifts the command shift stage to the selected shift stage at predetermined time intervals. 6. . The automatic transmission according to any one of claims 1 to 5, wherein downshifting is prohibited when the command gear stage is sequentially shifted by the failure part specifying control means.

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