JP6851699B2 - Automatic transmission clutch slip diagnostic device and clutch slip diagnostic method - Google Patents

Description

The present invention relates to a clutch slip diagnosis device and a clutch slip diagnosis method for an automatic transmission that determines that a pseudo-D state occurs when a clutch rotation difference of a predetermined value or more occurs in a traveling clutch during selection of a traveling range.

Conventionally, in the D range selected state, if the deviation between the indicated clutch torque and the estimated clutch torque is larger than the predetermined value, or the relative rotation speed difference is larger than the predetermined rotation speed, the automatic transmission is determined to be in the pseudo D state. A control device for the machine is known (see, for example, Patent Document 1).
Here, the "pseudo-D state" means that the traveling clutch, which should be in the engaged state while traveling in the traveling range (referring to the D range, the R range, the L range, etc.), unintentionally enters the clutch slip engaged state. Say that.

International Japanese Patent Application Laid-Open No. WO2014 / 034280

In the above-mentioned conventional device, the D range selection condition and the clutch differential rotation condition are used as the determination conditions for determining the pseudo D state. Therefore, there is a problem that if an abnormality occurs in the rotation sensor even though the traveling clutch is in the engaged state, it may be erroneously determined to be in the pseudo-D state due to the establishment of the pseudo-D determination condition.

For example, assume that the engine vehicle has a belt-type continuously variable transmission in which the engine → torque converter → traveling clutch → primary pulley → belt → secondary pulley are arranged from the upstream side of the drive system. In this case, if the traveling clutch is in the released state or the sliding engaged state during drive driving by depressing the accelerator, the rotation difference is Nt (= turbine speed)> Npri (= primary speed), and the rotation difference where Nt <Npri is Does not occur. However, in the clutch difference rotation condition of the pseudo D determination, since the rotation difference is equal to or greater than a predetermined value, for example, even if Nt <Npri due to a functional abnormality of the rotation sensor, it is erroneously determined that the pseudo D state is satisfied when the condition is satisfied.

The present invention has been made by paying attention to the above problem, and an object of the present invention is to prevent erroneous determination that the traveling clutch is in a pseudo D state when a differential rotation occurs in the traveling clutch in a state where the traveling range is selected. ..

In order to achieve the above object, the present invention determines that a pseudo D state is obtained when a clutch rotation difference of a predetermined value or more occurs between the automatic transmission, the traveling clutch, and the traveling range. It has a part and.
In the clutch slip diagnosis device of this automatic transmission, a drive source side rotation sensor and a drive wheel side rotation sensor for detecting the clutch rotation difference of the traveling clutch are provided.
When a rotation difference of a predetermined value or more occurs between the detected values from the two rotation sensors, the clutch slip diagnosis unit determines the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values. If it is determined that it corresponds to the torque transmission mode by the operation, it is determined that it is in the pseudo D state.

For example, during the selection of the traveling range, if a rotation difference of a predetermined value or more occurs between the detected values from the two rotation sensors, it is determined that the pseudo D state is obtained. However, since the pseudo-D determination is a determination using the detected value, even if the traveling clutch is not in the slip-engaged state, it is in the pseudo-D state when the rotation sensor has a functional abnormality that raises or lowers the detected value. Is erroneously determined.
Focusing on this point, by adding the judgment of the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship of the two rotation speed detection values to the pseudo D judgment condition, the pseudo D state and the rotation sensor function abnormality can be determined. Distinguishing, pseudo D erroneous judgment due to rotation sensor function abnormality was eliminated.
As a result, when a differential rotation occurs in the traveling clutch while the traveling range is selected, it is possible to prevent an erroneous determination that the traveling clutch is in the pseudo D state.

FIG. 5 is an overall system diagram showing a drive system and a control system of an engine vehicle to which the clutch slip diagnosis device and the clutch slip diagnosis method of the automatic transmission of the first embodiment are applied. It is a shift schedule diagram which shows an example of the D range stepless shift schedule used when the stepless shift control in an automatic shift mode is executed by a variator. It is a main part block diagram which shows the clutch slip diagnostic apparatus of Example 1. FIG. FIG. 1 is a flowchart 1 showing a flow of a pseudo-D determination process and a rotation sensor function abnormality diagnosis process executed by the clutch slip diagnosis unit of the CVT control unit of the first embodiment. FIG. 2 is a flowchart 2 showing a flow of a pseudo D determination process and a rotation sensor function abnormality diagnosis process executed by the clutch slip diagnosis unit of the CVT control unit of the first embodiment. It is a threshold map diagram which shows an example of the pseudo D judgment threshold value and the sensor function abnormality judgment threshold value when the vertical axis is the vehicle speed, and the clutch difference rotation of a turbine rotation speed and a primary rotation speed is a horizontal axis. It is a relational characteristic figure which shows the magnitude relation and the time-dependent change gradient relation between two rotation speed detection values when there is no rotation sensor function abnormality in the case of making pseudo D determination during drive running or coast running. In the relationship characteristic diagram showing the magnitude relationship of the three detected values and the aging gradient relationship when the turbine rotation sensor is malfunctioning when shifting from the pseudo D judgment to the rotation sensor function abnormality diagnosis during drive driving or coast driving. is there. In the relationship characteristic diagram showing the magnitude relationship of the three detected values and the aging gradient relationship when the primary rotation sensor is dysfunctional when shifting from the pseudo D judgment to the rotation sensor function abnormality diagnosis during drive driving or coast driving. is there.

Hereinafter, the best mode for realizing the clutch slip diagnosis device and the clutch slip diagnosis method for the automatic transmission of the present invention will be described with reference to Example 1 shown in the drawings.

First, the configuration will be described.
The clutch slip diagnosis device and the clutch slip diagnosis method in the first embodiment are an engine vehicle equipped with a belt-type continuously variable transmission (an example of an automatic transmission) composed of a torque converter, a forward / backward switching mechanism, a variator, and a final deceleration mechanism. It is applied to. Hereinafter, the configuration of the first embodiment will be described separately as "overall system configuration", "clutch slip diagnosis device configuration", and "pseudo-D determination processing and rotation sensor function abnormality diagnosis processing configuration".

[Overall system configuration]
FIG. 1 shows a drive system and a control system of an engine vehicle to which the clutch slip diagnosis device and the clutch slip diagnosis method of the automatic transmission of the first embodiment are applied. Hereinafter, the overall system configuration will be described with reference to FIG.

As shown in FIG. 1, the drive system of the engine vehicle includes an engine 1, a torque converter 2, a forward / backward switching mechanism 3, a variator 4, a final deceleration mechanism 5, and drive wheels 6 and 6. There is.
Here, the belt-type continuously variable transmission CVT is configured by incorporating a torque converter 2, a forward / backward switching mechanism 3, a variator 4, and a final deceleration mechanism 5 in a transmission case (not shown).

The engine 1 can control the output torque by an engine control signal from the outside, in addition to controlling the output torque by operating the accelerator by the driver. The engine 1 has an output torque control actuator 10 that controls torque by opening / closing a throttle valve, cutting fuel, or the like.

The torque converter 2 is a starting element by a fluid coupling having a torque increasing function and a torque fluctuation absorbing function. It has a lockup clutch 20 capable of directly connecting the engine output shaft 11 (= torque converter input shaft) and the torque converter output shaft 21 when the torque increasing function and the torque fluctuation absorbing function are not required. The torque converter 2 is provided with a pump impeller 23 connected to the engine output shaft 11 via a converter housing 22, a turbine runner 24 connected to the torque converter output shaft 21, and a one-way clutch 25 in the case. The stator 26 is a component.

The forward / backward switching mechanism 3 is a mechanism that switches the input rotation direction to the variator 4 between a forward rotation direction during forward travel and a reverse rotation direction during reverse travel. The forward / backward switching mechanism 3 includes a double pinion type planetary gear 30, a forward clutch 31 with a plurality of clutch plates, and a reverse brake 32 with a plurality of brake plates. The forward clutch 31 is hydraulically engaged by the forward clutch pressure Pfc when a forward traveling range such as the D range is selected. The reverse brake 32 is hydraulically engaged by the reverse brake pressure Prb when the reverse travel range such as the R range is selected. The forward clutch 31 and the reverse brake 32 are both released by draining the forward clutch pressure Pfc and the reverse brake pressure Prb when the N range (neutral range) is selected.

The variator 4 has a primary pulley 42, a secondary pulley 43, and a pulley belt 44, and steplessly changes the gear ratio (ratio of variator input rotation to variator output rotation) by changing the belt contact diameter. It has a shifting function. The primary pulley 42 is composed of a fixed pulley 42a and a slide pulley 42b arranged coaxially with the variator input shaft 40, and the slide pulley 42b slides by the primary pressure Ppri guided to the primary pressure chamber 45. The secondary pulley 43 is composed of a fixed pulley 43a and a slide pulley 43b arranged coaxially with the variator output shaft 41, and the slide pulley 43b slides by a secondary pressure Psec guided to the secondary pressure chamber 46. The pulley belt 44 is hung on the V-shaped sheave surface of the primary pulley 42 and the V-shaped sheave surface of the secondary pulley 43. The pulley belt 44 is formed of two sets of laminated rings in which a large number of annular rings are stacked from the inside to the outside and a punched plate material, and a large number of ring-shaped laminated rings are attached by sandwiching the two sets of laminated rings. It is composed of elements. The pulley belt 44 may be a chain type belt in which a large number of chain elements arranged in the pulley traveling direction are connected by pins penetrating in the pulley axial direction.

The final deceleration mechanism 5 is a mechanism that decelerates the variator output rotation from the variator output shaft 41, gives a differential function, and transmits the differential function to the left and right drive wheels 6 and 6. As a reduction gear mechanism, the final reduction gear 5 includes an output gear 52 provided on the variator output shaft 41, an idler gear 53 and a reduction gear 54 provided on the idler shaft 50, and a final gear provided at the outer peripheral position of the differential case. It has a gear 55 and. Then, as the differential gear mechanism, it has a differential gear 56 interposed between the left and right drive shafts 51 and 51.

As shown in FIG. 1, the control system of the engine vehicle includes a hydraulic control unit 7 representing a hydraulic control system and a CVT control unit 8 representing an electronic control system.

The hydraulic control unit 7 applies a primary pressure Ppri guided to the primary pressure chamber 45, a secondary pressure Psec guided to the secondary pressure chamber 46, a forward clutch pressure Pfc to the forward clutch 31, a reverse brake pressure Prb to the reverse brake 32, and the like. It is a unit that regulates pressure. The hydraulic control unit 7 includes an oil pump 70 that is rotationally driven by an engine 1 that is a driving drive source for traveling, and a hydraulic control circuit 71 that regulates various control pressures based on the discharge pressure from the oil pump 70. .. The hydraulic control circuit 71 includes a line pressure solenoid valve 72, a primary pressure solenoid valve 73, a secondary pressure solenoid valve 74, a select solenoid valve 75, and a lockup pressure solenoid valve 76. The solenoid valves 72, 73, 74, 75, 76 adjust to each command pressure according to the control command value output from the CVT control unit 8.

The line pressure solenoid valve 72 adjusts the discharge pressure from the oil pump 70 to the commanded line pressure PL according to the line pressure command value output from the CVT control unit 8. This line pressure PL is the original pressure when adjusting various control pressures, and is a flood control that suppresses belt slip and clutch slip with respect to the torque transmitted to the drive system.

The primary pressure solenoid valve 73 adjusts the pressure reduction to the commanded primary pressure Ppri with the line pressure PL as the original pressure according to the primary pressure command value output from the CVT control unit 8. The secondary pressure solenoid valve 74 adjusts the pressure reduction to the secondary pressure Psec commanded with the line pressure PL as the main pressure according to the secondary pressure command value output from the CVT control unit 8.

The select solenoid valve 75 adjusts the pressure reduction to the forward clutch pressure Pfc or the reverse brake pressure Prb commanded with the line pressure PL as the main pressure according to the forward clutch pressure command value or the reverse brake pressure command value output from the CVT control unit 8. To do.

The lockup pressure solenoid valve 76 adjusts the lockup control pressure PL / U for engaging / slip engaging / releasing the lockup clutch 20 according to the lockup pressure command value output from the CVT control unit 8.

The CVT control unit 8 performs line pressure control, shift control, forward / backward switching control, lockup control, and the like. In the line pressure control, a command value for obtaining a target line pressure according to a throttle opening or the like is output to the line pressure solenoid valve 72. In shift control, when the target gear ratio (target primary rotation Npri ^* ) is determined, a command value for obtaining the determined target gear ratio (target primary rotation Npri ^* ) is output to the primary pressure solenoid valve 73 and the secondary pressure solenoid valve 74. In the forward / backward switching control, a command value for controlling engagement / release of the forward clutch 31 and the reverse brake 32 is output to the select solenoid valve 75 according to the selected range position. In the lockup control, a command value for controlling the lockup control pressure PL / U that engages / engages / releases the lockup clutch 20 is output to the lockup pressure solenoid valve 76.

The CVT control unit 8 includes a primary rotation sensor 80, a vehicle speed sensor 81, a secondary pressure sensor 82, an oil temperature sensor 83, an inhibitor switch 84, a brake switch 85, an accelerator opening sensor 86, a primary pressure sensor 87, and a turbine rotation sensor 89. Sensor information and switch information from the secondary rotation sensor 90 and the like are input. Further, sensor information from the engine rotation sensor 12 is input to the engine control unit 88. For example, the CVT control unit 8 inputs engine torque information from the engine control unit 88 and outputs an engine torque request to the engine control unit 88.

FIG. 2 shows an example of a D-range continuously variable transmission schedule used when the variator 4 executes continuously variable transmission control in the automatic shift mode when the D-range is selected.

The "D range shifting mode" is an automatic shifting mode in which the gear ratio is automatically and steplessly changed according to the driving state of the vehicle. The shift control in the "D range shift mode" is performed by the operating point on the D range continuously variable transmission schedule of FIG. 2 specified by the vehicle speed VSP (vehicle speed sensor 81) and the accelerator opening APO (accelerator opening sensor 86). VSP, APO) determines the target primary rotation speed Npri ^* . Then, the primary rotation speed Npri from the primary rotation speed sensor 80 is controlled by the pulley hydraulic control to match the ^{target primary rotation speed Npri *.}

That is, as shown in FIG. 2, the D-range stepless shift schedule used in the "D-range shift mode" has a gear ratio range of the lowest gear ratio and the highest gear ratio according to the operating point (VSP, APO). It is set to change the gear ratio steplessly within the range. For example, when the vehicle speed VSP is constant, when the accelerator is depressed, the target primary rotation speed Npri ^* rises and shifts in the downshift direction, and when the accelerator is returned, the target primary rotation speed Npri ^* decreases and rises. Shift in the shift direction. When the accelerator opening APO is constant, the gear shifts in the upshift direction when the vehicle speed VSP increases, and shifts in the downshift direction when the vehicle speed VSP decreases.

[Clutch slip diagnostic device configuration]
FIG. 3 shows the clutch slip diagnostic device of the first embodiment. Hereinafter, the configuration of the clutch slip diagnostic device will be described with reference to FIG.

As shown in FIG. 3, the clutch slip diagnosis device includes a forward clutch 31 (traveling clutch), a reverse brake 32 (traveling clutch), a select solenoid valve 75, and a clutch slip diagnosing unit 8a. Then, as the main sensors and switches that provide input information to the clutch slip diagnosis unit 8a, the engine rotation sensor 12, the primary rotation sensor 80, the inhibitor switch 84, the turbine rotation sensor 89, the secondary rotation sensor 90, and the like. It has.

The forward clutch 31 and the reverse brake 32 are provided in parallel with the forward / backward switching mechanism 3 arranged between the torque converter 2 and the variator 4. The forward clutch 31 is engaged when the forward traveling range (D range, L range) is selected by the select lever 91, and is released when another range (P range, R range, N range) is selected. The reverse brake 32 is engaged when the reverse travel range (R range) is selected by the select lever 91, and is released when another range (P range, N range, D range, L range) is selected.

The select solenoid valve 75 controls engagement / release of the forward clutch 31 and the reverse brake 32 in conjunction with a select operation on the select lever 91 for selecting the range position of the belt-type continuously variable transmission CVT. In the case of the first embodiment, since the forward clutch 31 and the reverse brake 32 are not engaged at the same time, one select solenoid valve 75 having a three-way linear solenoid valve structure is used to control the engagement / release of the two traveling clutches. It is performed by one select solenoid valve 75.

The clutch slip diagnosis unit 8a is provided in the CVT control unit 8 which is an electronic control device of the belt-type continuously variable transmission, and performs pseudo-D determination processing and rotation sensor function abnormality diagnosis processing. In the pseudo-D determination process, when a rotation difference of a predetermined value or more occurs between the detected values from the turbine rotation sensor 89 and the primary rotation sensor 80, the magnitude relationship between the two rotation speed detection values and the aging gradient relationship are determined by the accelerator operation. It is determined whether or not there is a correspondence relationship with the torque transmission mode. Then, when it is determined that the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values correspond to the torque transmission mode by the accelerator operation, it is determined that the state is a pseudo D state. ..

Here, the "torque transmission mode by accelerator operation" is defined as
(A) A mode in which torque is transmitted from the engine 1 to the drive wheels 6 during drive acceleration running by accelerator depression operation or drive constant speed running by accelerator fixing operation.
(B) A mode in which torque is transmitted from the engine 1 to the drive wheels 6 during drive deceleration running by the accelerator return operation.
(C) A mode in which torque is transmitted from the drive wheels 6 to the engine 1 during coast running (inertial running) by releasing the accelerator foot, which is classified into three types.

The rotation sensor function abnormality diagnosis process is performed immediately when the clutch slip diagnosis unit 8a determines that the temporal change gradient relationship of the two detected values does not correspond to the torque transmission mode by the accelerator operation during the pseudo D determination process. Is started. When executing the rotation sensor function abnormality diagnosis, one rotation detection value is used by using three or more rotation detection values obtained by adding the detection values indicating the rotation of at least one of the drive source side and the drive wheel side to the two detection values. When the change gradient of is different from the change gradient of the other two or more rotation detection values, it is diagnosed that the rotation sensor having a different relationship is dysfunctional. The rotation sensor function abnormality diagnosis process includes a process of diagnosing a function abnormality of the turbine rotation sensor 89 and a process of diagnosing a function abnormality of the primary rotation sensor 80.

The inhibitor switch 84 detects the range position (P range, R range, N range, D range, L range) selected by the select lever 91, and outputs a range position signal according to the range position. The select operation by the driver is detected by monitoring the range position signal from the inhibitor switch 84. The select operation by the driver includes not only the operation by the select lever 91 but also the operation by the select switch or the like.

The turbine rotation sensor 89 is a sensor that detects the turbine rotation speed Nt, which is the rotation of the torque converter output shaft 21 connected to the turbine runner 24 of the torque converter 2, by the pulse count number, which is the count number of pulse wave signals. This turbine rotation speed Nt corresponds to the clutch input rotation speed of the traveling clutch.

The primary rotation sensor 80 is a sensor that detects the primary rotation speed Npri, which is the rotation of the variator input shaft 40 connected to the primary pulley 42, by the pulse count number, which is the count number of pulse wave signals. This primary rotation speed Npri corresponds to the clutch output rotation speed of the traveling clutch.

The engine rotation sensor 12 is a sensor that detects the engine rotation speed Ne, which is the rotation of the crankshaft of the engine 1, by the pulse count number, which is the count number of pulse wave signals. This engine speed Ne becomes a speed proportional to the clutch input speed of the traveling clutch at the time of lockup / off.

The secondary rotation sensor 90 is a sensor that detects the secondary rotation speed Nsec, which is the rotation of the variator output shaft 41 connected to the secondary pulley 43, by the pulse count number, which is the count number of pulse wave signals. A calculated value corresponding to the output rotation speed of the traveling clutch can be obtained by converting the secondary rotation speed Nsec into the input rotation speed of the variator 4 using the gear ratio RATIO of the variator 4.

[Pseudo D judgment processing and rotation sensor function abnormality diagnosis processing configuration]
4 and 5 show the flow of the pseudo-D determination process and the rotation sensor function abnormality diagnosis process executed by the clutch slip diagnosis unit 8a of the CVT control unit 8 of the first embodiment. Hereinafter, each step of FIGS. 4 and 5 showing the pseudo-D determination process and the rotation sensor function abnormality diagnosis process configuration will be described.

In step S1, it is determined whether or not the traveling range (D range, L range, R range) is selected. If YES (selecting a traveling range), the process proceeds to step S2, and if NO (selecting a non-traveling range), the determination in step S1 is repeated.

In step S2, following the determination that the traveling range is being selected in step S1, it is determined whether or not the vehicle speed VSP acquired by the vehicle speed sensor 81 is equal to or greater than the vehicle speed threshold value. If YES (vehicle speed VSP ≥ vehicle speed threshold value), the process proceeds to step S3, and if NO (vehicle speed VSP <vehicle speed threshold value), the process returns to step S1.

Here, the "vehicle speed threshold" is set to the lower limit value of the vehicle speed VSP in which the clutch difference rotation based on the absolute difference between the turbine rotation speed Nt and the primary rotation speed Npri is larger than the variation width between the turbine rotation sensor 89 and the primary rotation sensor 80. Will be done. This is because when the vehicle speed VSP is less than the vehicle speed threshold value, the pseudo D determination cannot be accurately executed.

In step S3, following the determination that the vehicle speed VSP ≥ the vehicle speed threshold value in step S2, it is determined whether or not the accelerator opening APO is driving driving with APO> 0. If YES (APO> 0: drive driving), the process proceeds to step S4, and if NO (APO = 0: coast driving), the process proceeds to step S14.

In step S4, following the determination that APO> 0 in step S3, whether or not the clutch differential rotation due to the difference between the turbine rotation speed Nt and the primary rotation speed Npri is equal to or less than the first differential rotation speed threshold ΔN1. to decide. If YES (Nt−Npri ≦ 1st differential rotation threshold ΔN1), the process proceeds to step S5, and if NO (Nt−Npri> 1st differential rotation threshold ΔN1), the process proceeds to step S8.

Here, the clutch difference rotation is calculated by (Nt-Npri) because the torque transmission direction is driving from the engine 1 to the drive wheels 6, so the magnitude relationship between the turbine rotation speed Nt and the primary rotation speed Npri is. By becoming Nt> Npri. As shown in FIG. 6, the “first differential rotation threshold value ΔN1” is set to the lower limit value (for example, about 500 rpm) of the pseudo D determination range on the drive side.

In step S5, following the determination that Nt−Npri ≦ the first differential rotation threshold value ΔN1 in step S4, the pseudo D control flag F indicates that F = 0 (the pseudo D control during traveling is not executed). ) Is determined. If YES (F = 0), the process proceeds to step S7, and if NO (F = 1), the process proceeds to step S6.

In step S6, following the determination in step S5 that F = 1 (representing the execution of pseudo D control during traveling), the pseudo D control flag F is rewritten from F = 1 to F = 0, and the step is taken. Proceed to S7.

In step S7, following the determination that F = 0 in step S5 or the rewriting of step S6 to F = 0, the normal state control is executed, and the process proceeds to return.
Here, the normal control means, for example, engine control that does not regulate torque when the D range is selected, normal lockup control based on the lockup schedule, and stepless control based on the D range continuously variable transmission schedule shown in FIG. It means to perform shift control. When the pseudo D control during running is switched to the normal control, the lockup-off control and engine torque regulation control executed as belt protection control during the running pseudo D control are stopped, and then the normal control is started. Transition.

In step S8, following the determination in step S4 that Nt-Npri> the first differential rotation threshold value ΔN1, the time-dependent gradient relationship of the values detected from the turbine rotation sensor 89 and the primary rotation sensor 80 corresponds to the drive driving scene. Determine if you are doing it. If YES (with correspondence), the process proceeds to step S9, and if NO (no correspondence), the process proceeds to step S11. The details of determining whether or not the time-dependent gradient relationship of the values detected from the turbine rotation sensor 89 and the primary rotation sensor 80 corresponds to the drive driving scene will be described later.

In step S9, following the determination that there is a correspondence relationship in step S8, it is determined whether or not the clutch differential rotation due to the difference between the turbine rotation speed Nt and the primary rotation speed Npri is equal to or less than the second differential rotation speed threshold ΔN2. .. If YES (Nt−Npri ≦ 2nd differential rotation threshold ΔN2), the process proceeds to step S10, and if NO (Nt−Npri> 2nd differential rotation threshold ΔN2), the process proceeds to step S12.

Here, the "second differential rotation threshold value ΔN2" is a value in the maximum range that is possible as the clutch differential rotation that separates the pseudo D range from the rotation sensor function abnormality range, and as shown in FIG. 6, the pseudo D on the drive side. It is set to the upper limit of the judgment range (for example, about 1000 rpm).

In step S10, following the determination in step S9 that Nt−Npri ≦ the second differential rotation threshold value ΔN2, the pseudo D control flag F is set to F = 1, pseudo D control during traveling is executed, and the process proceeds to return.

Here, the "pseudo-D control during running" regulates the release control of the lockup clutch 20 executed for the purpose of protecting the belt when the clutch of the running clutch slips, and the upper limit value of the engine torque output from the engine 1. It is called torque regulation control.

In step S11, following the determination that there is no correspondence in step S8, one detected value is added to the detected values from the turbine rotation sensor 89 and the primary rotation sensor 80, and the three values change with time. It is determined whether or not one value has an out-of-group relationship, that is, whether or not the change gradient of one rotation detection value has a different relationship from the change gradient of another rotation detection value. If YES (there is a relationship of being out of friends), the process proceeds to step S12, and if NO (there is no relationship of being out of friends), the process returns to step S1. In addition, one detected value is added to the detected values from the turbine rotation sensor 89 and the primary rotation sensor 80, and the detailed judgment contents as to whether or not one value is out of the group in the aging gradient relationship of the three values is described. It will be described later.

In step S12, following the determination in step S9 that Nt-Npri> the second differential rotation threshold value ΔN2, the determination in step S11 that there is a relationship of being out of the group, or the determination that the ignition is ON in step S13. The abnormality protection control is executed, and the process proceeds to step S13.

Here, the "abnormality protection control" means the release control of the lockup clutch 20 executed for the purpose of protecting the unit and the engine torque upper limit value of the engine 1 while notifying the driver when the rotation sensor function abnormality is diagnosed. It is called torque regulation control to regulate. In addition, when the turbine rotation sensor 89 is diagnosed as malfunctioning, the detection value from the turbine rotation sensor 89 is stopped to be used, and the turbine rotation speed Nt is replaced with the primary rotation speed Npri. When the primary rotation sensor 80 is diagnosed as having a malfunction, the value detected from the primary rotation sensor 80 is stopped to be used, and the primary rotation speed Npri is replaced with the turbine rotation speed Nt.

In step S13, following the execution of the abnormality protection control in step S12, it is determined whether or not the ignition switch is OFF. If YES (ignition OFF), the process proceeds to the end, and if NO (ignition ON), the process returns to step S12.

In step S14, following the determination that APO = 0 in step S3, whether or not the clutch differential rotation due to the difference between the primary rotation speed Npri and the turbine rotation speed Nt is equal to or less than the third differential rotation speed threshold ΔN3. to decide. If YES (Npri−Nt ≦ 3rd differential rotation threshold ΔN3), the process proceeds to step S15, and if NO (Npri−Nt> 3rd differential rotation threshold ΔN3), the process proceeds to step S18.

Here, the clutch difference rotation was calculated by (Npri-Nt) because the torque transmission direction is running on the coast from the drive wheels 6 to the engine 1, so the magnitude relationship between the turbine rotation speed Nt and the primary rotation speed Npri is By becoming Nt <Npri. As shown in FIG. 6, the “third differential rotation threshold value ΔN3” is set to the lower limit value (for example, about 150 rpm) of the pseudo D determination range on the coast side. The reason why the lower limit of the pseudo D judgment range on the coast side is set to the difference rotation speed smaller than the lower limit of the pseudo D judgment range on the drive side is that the expansion of the clutch difference rotation when the sliding engagement is started is the drive. This is because it is smaller while driving on the coast than when driving.

In step S15, following the determination in step S14 that Npri−Nt ≦ the third differential rotation threshold value ΔN3, the pseudo D control flag F indicates that F = 0 (pseudo D control during traveling is not being executed). ). If YES (F = 0), the process proceeds to step S17, and if NO (F = 1), the process proceeds to step S16.

In step S16, following the determination in step S15 that F = 1 (representing the execution of the pseudo D control during traveling), the pseudo D control flag F is rewritten from F = 1 to F = 0, and the step is taken. Proceed to S17.

In step S17, following the determination that F = 0 in step S15 or the rewriting of step S16 to F = 0, the normal state control is executed, and the process proceeds to return. The “normal control” is the same as in step S7.

In step S18, following the determination in step S14 that Npri-Nt> the third differential rotation threshold value ΔN3, the aging gradient relationship of the values detected from the turbine rotation sensor 89 and the primary rotation sensor 80 corresponds to the coast running scene. Determine if you are doing it. If YES (with correspondence), the process proceeds to step S19, and if NO (no correspondence), the process proceeds to step S21. The details of determining whether or not the time-dependent gradient relationship of the values detected from the turbine rotation sensor 89 and the primary rotation sensor 80 corresponds to the coastal driving scene will be described later.

In step S19, following the determination that there is a correspondence relationship in step S18, it is determined whether or not the clutch differential rotation due to the difference between the primary rotation speed Npri and the turbine rotation speed Nt is equal to or less than the second differential rotation speed threshold ΔN2. .. If YES (Npri−Nt ≦ 2nd differential rotation threshold ΔN2), the process proceeds to step S20, and if NO (Npri−Nt> 2nd differential rotation threshold ΔN2), the process proceeds to step S22.

Here, the "second differential rotation threshold value ΔN2" is a value in the maximum range that is possible as the clutch differential rotation that separates the pseudo D range from the rotation sensor function abnormality range, and as shown in FIG. 6, the pseudo D on the coast side. It is set to the upper limit of the judgment range (for example, about 1000 rpm). The upper limit of the pseudo-D determination range is the same on both the coast side and the drive side.

In step S20, following the determination in step S19 that Npri−Nt ≦ the second differential rotation threshold value ΔN2, the pseudo D control flag F is set to F = 1, pseudo D control during traveling is executed, and the process proceeds to return. The "pseudo-D control during traveling" is the same as in step S10.

In step S21, following the determination that there is no correspondence in step S18, one detected value is added to the detected values from the turbine rotation sensor 89 and the primary rotation sensor 80, and the three values change with time. Determine if the two values are out of sync. If YES (there is a relationship of being out of friends), the process proceeds to step S22, and if NO (there is no relationship of being out of friends), the process returns to step S1. In addition, one detected value is added to the detected values from the turbine rotation sensor 89 and the primary rotation sensor 80, and the detailed judgment contents as to whether or not one value is out of the group in the aging gradient relationship of the three values is described. It will be described later.

In step S22, following the determination in step S19 that Npri-Nt> the second differential rotation threshold value ΔN2, the determination in step S21 that there is a relationship of being out of the group, or the determination that the ignition is ON in step S23. The abnormality protection control is executed, and the process proceeds to step S23. The "abnormality protection control" is the same as in step S12.

In step S23, following the execution of the abnormality protection control in step S22, it is determined whether or not the ignition switch is OFF. If YES (ignition OFF), the process proceeds to the end, and if NO (ignition ON), the process returns to step S22.

Next, the action will be described.
The actions of Example 1 are "pseudo D judgment processing action and rotation sensor function abnormality diagnosis processing action", "pseudo D judgment action", "turbine rotation sensor function abnormality diagnosis action", and "primary rotation sensor function abnormality diagnosis action". Will be explained separately.

[Pseudo D judgment processing action and rotation sensor function abnormality diagnosis processing action]
The pseudo-D determination processing action and the rotation sensor function abnormality diagnosis processing action will be described with reference to FIGS. 4 and 5.

When the forward clutch 31 is maintained in the fully engaged state during the drive running with the D range selected, Nt−Npri ≦ the first differential rotation threshold value ΔN1. Therefore, the flow of step S1 → step S2 → step S3 → step S4 → step S5 → step S7 → return is repeated. Therefore, in step S7, normal control is executed.

After that, while driving with the D range selected, the forward clutch 31 shifts to the slip-engaged state due to insufficient clutch oil pressure to the forward clutch 31 or fluctuations in the input torque to the drive system, and Nt-Npri> first differential rotation. It is assumed that the threshold value ΔN1 is reached. In this case, the process proceeds from step S1 → step S2 → step S3 → step S4 → step S8. In step S8, the cause of Nt-Npri> first differential rotation threshold value ΔN1 is the transition of the forward clutch 31 to the slip-engaged state, so that the values detected from the turbine rotation sensor 89 and the primary rotation sensor 80 change with time. It is judged that the gradient relationship corresponds to the driving scene. Therefore, while the sliding engagement state of the forward clutch 31 continues, the flow of step S8 → step S9 → step S10 → return is repeated. Therefore, in step S10, the execution of the running pseudo-D control that protects the pulley belt 44 in the sliding engaged state of the forward clutch 31 is continued.

After that, when the forward clutch 31 returns from the slip-engaged state to the completely engaged state, the process proceeds in the order of step S1 → step S2 → step S3 → step S4 → step S5 → step S6 → step S7 → return. Therefore, in step S7, the control return from the execution of the pseudo D control during traveling to the execution of the normal control is realized.

On the other hand, while the drive is running with the D range selected, the forward clutch 31 is maintained in a completely engaged state, but due to a malfunction of the turbine rotation sensor 89 and the primary rotation sensor 80, Nt-Npri> first differential rotation threshold value. Suppose that it becomes ΔN1. In this case, the process proceeds from step S1 → step S2 → step S3 → step S4 → step S8. In step S8, the cause of Nt-Npri> first differential rotation threshold value ΔN1 is an abnormality in the rotation sensor function, and the time-dependent gradient relationship of the values detected from the turbine rotation sensor 89 and the primary rotation sensor 80 is the drive driving scene. It is judged that it does not correspond to. Therefore, the process proceeds from step S8 to step S11, and the rotation sensor function abnormality diagnosis is started.

In step S11, one detected value is added to the detected values from the turbine rotation sensor 89 and the primary rotation sensor 80, and when it is determined that one value is out of the group in the aging gradient relationship of the three values, the step is taken. The process proceeds from S11 to step S12. In step S12, the protection control at the time of abnormality due to the turbine rotation sensor function abnormality or the primary rotation sensor function abnormality is executed.

Further, during the drive running with the D range selected, Nt-Npri> the first differential rotation threshold value ΔN1 due to a malfunction of the turbine rotation sensor 89 and the primary rotation sensor 80, and the time-dependent gradient relationship between the two detected values. Remains determined to correspond to the driving scene. In this case, the flow of step S1 → step S2 → step S3 → step S4 → step S8 → step S9 → step S10 → return is repeated. If it is determined in step S9 in the middle of this that Nt-Npri> the second differential rotation threshold value ΔN2, the process proceeds from step S9 to step S12, and in step S12, the protection control at the time of abnormality is executed.

When the forward clutch 31 is maintained in the fully engaged state during coast running with the D range selected, Npri−Nt ≦ the third differential rotation threshold value ΔN3. Therefore, the flow of step S1 → step S2 → step S3 → step S14 → step S15 → step S17 → return is repeated. Therefore, in step S17, normal control is executed.

After that, while traveling on the coast with the D range selected, the forward clutch 31 shifts to the slip-engaged state due to insufficient clutch oil pressure to the forward clutch 31 or fluctuations in the input torque to the drive system, and Npri-Nt> third differential rotation. It is assumed that the threshold value ΔN3 is reached. In this case, the process proceeds from step S1 → step S2 → step S3 → step S14 → step S18. In step S18, the cause of Npri-Nt> the third differential rotation threshold value ΔN3 is the transition of the forward clutch 31 to the slip-engaged state, so that the values detected from the turbine rotation sensor 89 and the primary rotation sensor 80 change with time. It is judged that the gradient relationship corresponds to the coast driving scene. Therefore, while the sliding engagement state of the forward clutch 31 continues, the flow of step S18 → step S19 → step S20 → return is repeated. Therefore, in step S20, the execution of the running pseudo-D control that protects the pulley belt 44 in the sliding engagement state of the forward clutch 31 is continued.

After that, when the forward clutch 31 returns from the slip-engaged state to the completely engaged state, the process proceeds in the order of step S1 → step S2 → step S3 → step S14 → step S15 → step S16 → step S17 → return. Therefore, in step S17, the control return from the execution of the pseudo-D control during traveling to the execution of the normal control is realized.

On the other hand, while the forward clutch 31 is in a completely engaged state while traveling on the coast with the D range selected, due to a malfunction of the turbine rotation sensor 89 and the primary rotation sensor 80, Npri-Nt> the third differential rotation threshold value. Suppose that it becomes ΔN3. In this case, the process proceeds from step S1 → step S2 → step S3 → step S14 → step S18. In step S18, the cause of Npri-Nt> the third differential rotation threshold value ΔN3 is a rotation sensor function abnormality, and the time-dependent gradient relationship of the detected values from the turbine rotation sensor 89 and the primary rotation sensor 80 is the coast running scene. It is judged that it does not correspond to. Therefore, the process proceeds from step S18 to step S21, and the rotation sensor function abnormality diagnosis is started.

In step S21, one detected value is added to the detected values from the turbine rotation sensor 89 and the primary rotation sensor 80, and when it is determined that one value is out of the group in the aging gradient relationship of the three values, the step is taken. The process proceeds from S21 to step S22. In step S22, the protection control at the time of abnormality due to the turbine rotation sensor function abnormality or the primary rotation sensor function abnormality is executed.

Further, during coastal driving with the D range selected, Npri-Nt> the third differential rotation threshold value ΔN3 due to a malfunction of the turbine rotation sensor 89 and the primary rotation sensor 80, and the time-dependent gradient relationship between the two detected values. Remains determined to correspond to the coastal driving scene. In this case, the flow of step S1 → step S2 → step S3 → step S14 → step S18 → step S19 → step S20 → return is repeated. If it is determined in step S19 in the middle of this that Npri-Nt> the second differential rotation threshold value ΔN2, the process proceeds from step S19 to step S22, and in step S22, the protection control at the time of abnormality is executed.

As described above, in the first embodiment, the rotation difference between the turbine rotation speed Nt and the primary rotation speed Npri from the two rotation sensors 89 and 80 is equal to or larger than a predetermined value (first difference rotation threshold ΔN1 or third difference rotation threshold ΔN3). If it occurs, the following judgment conditions are added, and it is determined that the state is a pseudo D state.
(a) The magnitude relationship between the turbine rotation speed Nt and the primary rotation speed Npri, which are the two detected values, corresponds to the torque transmission mode by the accelerator operation (S4, S14).
(b) The relationship between the two detected values, the turbine speed Nt and the primary speed Npri over time, corresponds to the torque transmission mode by accelerator operation (YES in S8 and YES in S18).

That is, when the present inventors determine that a pseudo-D state occurs when a rotation difference of a predetermined value or more occurs between the detected values from the two rotation sensors during the selection of the traveling range, the rotation sensor raises or lowers the detected value. We paid attention to the fact that when there is a functional abnormality such as, it is erroneously determined as a pseudo D state.

Therefore, by adding the judgment of the magnitude relation between the two rotation speed detection values and the temporal change gradient relation to the pseudo D judgment condition, the pseudo D state and the rotation sensor function abnormality can be distinguished, and the pseudo D erroneous judgment due to the rotation sensor function abnormality can be made. I tried to eliminate. As a result, when a differential rotation occurs in the traveling clutch while the traveling range is selected, it is possible to prevent an erroneous determination that the traveling clutch is in the pseudo D state.

In the first embodiment, when a rotation difference of a predetermined value (first difference rotation threshold ΔN1 or third difference rotation threshold ΔN3) or more occurs between the turbine rotation speed Nt and the primary rotation speed Npri from the two rotation sensors 89 and 80. If the above judgment condition (b) is not satisfied, the rotation sensor function abnormality diagnosis is executed.

That is, without the judgment condition (b), the execution of the pseudo D control during traveling is continued when the rotation sensor has a functional abnormality that raises or lowers the detected value. Therefore, while the running pseudo-D control is being executed, the rotation sensor function abnormality diagnosis process is not started, and the transition to the rotation sensor function abnormality diagnosis is delayed. On the other hand, the judgment condition (b) is set as a condition for distinguishing between the pseudo D state and the rotation sensor function abnormality. Therefore, when the rotation sensor function abnormality is recognized, the rotation sensor is immediately determined from the pseudo D judgment. Move to dysfunction diagnosis. As a result, when the rotation sensor has a functional abnormality that raises or lowers the detected value, the rotation sensor function abnormality diagnosis process is started without delay.

[Pseudo D judgment action]
FIG. 7 shows the magnitude relationship and the aging gradient relationship between the two rotation speed detection values when there is no rotation sensor function abnormality when the pseudo D determination is performed during drive driving or coast driving. Hereinafter, the pseudo-D determination action will be described with reference to FIG. 7.

When determining the pseudo-D, when determining the magnitude relationship of the detected values and the temporal change gradient relationship in the situation where the clutch differential rotation condition is satisfied, at least two detected values of the turbine rotation speed Nt and the primary rotation speed Npri are used. .. Then, the driving scene is divided into a driving driving scene (accelerator ON & torque up, accelerator ON & torque down) and a coast driving scene by accelerator operation. Here, the turbine rotation change gradient ΔNt acquires the detected value from the turbine rotation sensor 89 by differential calculation processing (difference per unit time). Similarly, the primary rotation change gradient ΔNpri acquires the detected value from the primary rotation sensor 80 by differential calculation processing (difference per unit time).

In the case of drive acceleration driving scene (accelerator ON & torque up), when the traveling clutch is fully engaged, Nt = Npri as shown in the upper left frame of FIG. 7, and both change gradients ΔNt and ΔNpri rise to the right. It becomes a gradient. On the other hand, when the slip is engaged due to the disengagement of the traveling clutch, the engine 1 blows up, and as shown in the upper right frame of FIG. 7, the upward-sloping gradient angle of the turbine rotation change gradient ΔNt becomes large. On the other hand, the primary rotation change gradient ΔNpri has a smaller upward-sloping gradient angle.

Therefore, in the drive acceleration driving scene (accelerator ON & torque up), when the traveling clutch starts slipping at time t1 and the clutch differential rotation reaches the first differential rotation threshold value ΔN1 at time t2, Nt> Npri and , ΔNt> ΔNpri> 0 (positive gradient). In this case, the magnitude relationship between the turbine rotation speed Nt and the primary rotation speed Npri and the aging gradient relationship correspond to the drive acceleration driving scene. That is, since the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values correspond to the torque transmission mode by the accelerator operation, it is determined to be in the pseudo D state.

For example, when a functional abnormality occurs in which the turbine rotation speed Nt from the turbine rotation sensor 89 decreases, the turbine rotation change gradient ΔNt becomes a downward-sloping gradient. Therefore, when the clutch differential rotation reaches the first differential rotation threshold value ΔN1, if the relationship is Nt <Npri and ΔNt <0 (negative gradient), it does not correspond to the drive acceleration traveling scene. That is, since the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values do not correspond to the torque transmission mode by the accelerator operation, the pseudo D is not determined and the rotation sensor function abnormality diagnosis is performed. Transition.

Even in the case of a constant-speed drive scene in which the accelerator opening APO is kept constant, the engine 1 blows up when the clutch is disengaged due to the disengagement of the traveling clutch, and the turbine rotation change gradient ΔNt has a large upward slope angle. Therefore, the pseudo D state can be determined.

In the case of drive deceleration driving scene (accelerator ON & torque down), when the traveling clutch is fully engaged, Nt = Npri as shown in the middle left frame of FIG. 7, and both change gradients ΔNt and ΔNpri decrease to the right. It becomes a gradient. On the other hand, when the slip is engaged due to the disengagement of the traveling clutch, the engine 1 blows up, and as shown in the central right frame of FIG. 7, the downward slope angle of the turbine rotation change gradient ΔNt becomes smaller. On the other hand, the primary rotation change gradient ΔNpri has a large downward-sloping gradient angle.

Therefore, in the drive deceleration driving scene (accelerator ON & torque down), when the traveling clutch starts slipping at time t1 and the clutch differential rotation reaches the first differential rotation threshold value ΔN1 at time t2, Nt> Npri and , 0> ΔNpri> ΔNt (negative gradient). In this case, the magnitude relationship between the turbine rotation speed Nt and the primary rotation speed Npri and the aging gradient relationship correspond to the drive deceleration running scene. That is, since the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values correspond to the torque transmission mode by the accelerator operation, it is determined to be in the pseudo D state.

For example, when a functional abnormality occurs in which the turbine rotation speed Nt increases from the turbine rotation sensor 89, the turbine rotation change gradient ΔNt becomes an upward slope to the right. Therefore, when the clutch differential rotation reaches the first differential rotation threshold value ΔN1, if the relationship is Nt> Npri and ΔNt> 0 (positive gradient), it does not correspond to the drive deceleration running scene. That is, since the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values do not correspond to the torque transmission mode by the accelerator operation, the pseudo D is not determined and the rotation sensor function abnormality diagnosis is performed. Transition.

In the case of a coast running scene by releasing the accelerator foot, when the running clutch is fully engaged, Nt = Npri as shown in the lower left frame of FIG. 7, and both change gradients ΔNt and ΔNpri are gradual downward to the right. Gradient. On the other hand, the engine 1 does not blow up even if the clutch is disengaged due to the disengagement of the traveling clutch, and the turbine rotation change gradient ΔNt maintains a gentle downward-sloping gradient angle as shown in the lower right frame of FIG. .. On the other hand, in the primary rotation change gradient ΔNpri, the downward-sloping gradient angle gradually decreases.

Therefore, in the coast deceleration driving scene, when the traveling clutch starts sliding at time t1 and the clutch differential rotation reaches the third differential rotation threshold value ΔN3 at time t2, Npri> Nt and 0> ΔNpri> ΔNt. It becomes a (negative gradient) relationship. In this case, the magnitude relationship between the turbine rotation speed Nt and the primary rotation speed Npri and the aging gradient relationship correspond to the coast deceleration running scene. That is, since the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values correspond to the torque transmission mode by the accelerator operation, it is determined to be in the pseudo D state.

For example, when a functional abnormality occurs in which the turbine rotation speed Nt increases from the turbine rotation sensor 89, the turbine rotation change gradient ΔNt becomes an upward slope to the right. Therefore, when the clutch differential rotation reaches the third differential rotation threshold value ΔN3, if the relationship is Nt> Npri and ΔNt> 0 (positive gradient), it does not correspond to the coastal driving scene. That is, since the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values do not correspond to the torque transmission mode by the accelerator operation, the pseudo D is not determined and the rotation sensor function abnormality diagnosis is performed. Transition.

[Diagnosis of abnormal function of turbine rotation sensor]
FIG. 8 shows the magnitude relationship and the aging gradient relationship of the three detected values when the turbine rotation sensor 89 is malfunctioning when the pseudo-D judgment is shifted to the rotation sensor function abnormality diagnosis during drive driving or coast driving. Shown. Hereinafter, the function abnormality diagnosis action of the turbine rotation sensor 89 will be described with reference to FIG.

When it is determined in the pseudo-D judgment that the change gradient does not correspond to each driving scene and the function abnormality diagnosis of the turbine rotation speed sensor 89 is executed, at least the turbine rotation speed Nt, the primary rotation speed Npri, and the engine rotation speed Ne (gradient characteristics) Is similar to Nt). Then, as in the pseudo-D determination, the driving scene is divided into a driving driving scene (accelerator ON & torque up, accelerator ON & torque down) and a coast driving scene by accelerator operation.

In the case of drive acceleration driving scene (accelerator ON & torque up), when the function of the turbine rotation sensor 89 is normal, as shown in the upper left frame of FIG. 8, the engine rotation change gradient ΔNe, the turbine rotation change gradient ΔNt, and the primary rotation change gradient ΔNpri Has the same upward slope. On the other hand, when the turbine rotation speed Nt from the turbine rotation sensor 89 gradually decreases due to water entry or the like, the turbine rotation change gradient ΔNt changes from an upward-sloping gradient to a downward-sloping gradient as shown in the upper left frame of FIG. Transition. That is, the characteristic of the turbine rotation speed (Nt) shown by the broken line in the upper left frame of FIG. 8 shifts to the characteristic of the turbine rotation speed Nt shown by the fine solid line in the upper left frame of FIG.

Therefore, of the turbine speed Nt, the primary speed Npri, and the engine speed Ne, the turbine speed change gradient ΔNt is different from the other two change gradients ΔNe and ΔNpri. (Relationship different from the gradient of the rotation speed detection value). Then, the turbine rotation change gradient ΔNt moves in the opposite direction to the engine rotation change gradient ΔNe. Therefore, the turbine rotation sensor 89, which has a different relationship, is diagnosed as having a malfunction.

In the case of drive deceleration running scene (accelerator ON & torque down), when the function of the turbine rotation sensor 89 is normal, as shown in the middle right frame of FIG. 8, the engine rotation change gradient ΔNe, the turbine rotation change gradient ΔNt, and the primary rotation change gradient ΔNpri Has the same downward slope. On the other hand, when the turbine rotation speed Nt from the turbine rotation sensor 89 gradually increases due to pulse cracking or the like, the turbine rotation change gradient ΔNt changes from a downward-sloping gradient to an upward-sloping gradient as shown in the central right frame of FIG. Transition. That is, the characteristic of the turbine rotation speed (Nt) shown by the broken line in the central right frame of FIG. 8 shifts to the characteristic of the turbine rotation speed Nt shown by the fine solid line in the central right frame of FIG.

Therefore, of the turbine speed Nt, the primary speed Npri, and the engine speed Ne, the turbine speed change gradient ΔNt is different from the other two change gradients ΔNe and ΔNpri. Then, the turbine rotation change gradient ΔNt moves in the opposite direction to the engine rotation change gradient ΔNe. Therefore, the turbine rotation sensor 89 is diagnosed as having a malfunction.

In the case of a coast running scene by releasing the accelerator foot, when the function of the turbine rotation sensor 89 is normal, the engine rotation change gradient ΔNe, the turbine rotation change gradient ΔNt, and the primary rotation change gradient ΔNpri are the same as shown in the lower right frame of FIG. It becomes a downward slope. On the other hand, when the turbine rotation speed Nt from the turbine rotation sensor 89 gradually increases due to pulse cracking or the like, the turbine rotation change gradient ΔNt changes from a downward-sloping gradient to an upward-sloping gradient as shown in the lower right frame of FIG. Transition. That is, the characteristic of the turbine rotation speed (Nt) shown by the broken line in the lower right frame of FIG. 8 shifts to the characteristic of the turbine rotation speed Nt shown by the fine solid line in the lower right frame of FIG.

Therefore, of the turbine speed Nt, the primary speed Npri, and the engine speed Ne, the turbine speed change gradient ΔNt is different from the other two change gradients ΔNe and ΔNpri. And, in the coast running scene by the accelerator foot release operation, the turbine rotation speed Nt does not increase. Therefore, the turbine rotation sensor 89 is diagnosed as having a malfunction.

[Diagnosis of functional abnormality of primary rotation sensor]
FIG. 9 shows the magnitude relationship and the aging gradient relationship of the three detected values when the primary rotation sensor 80 is dysfunctional when shifting from the pseudo D judgment to the rotation sensor function abnormality diagnosis during drive driving or coast driving. Shown. Hereinafter, the function abnormality diagnosis action of the primary rotation sensor 80 will be described with reference to FIG.

When it is determined in the pseudo-D determination that the change gradient does not correspond to each driving scene and the functional abnormality diagnosis of the primary rotation sensor 80 is executed, at least the turbine rotation speed Nt, the primary rotation speed Npri, and the primary calculation rotation speed Npri # ( The three values of gradient characteristics (similar to Npri) are used. Then, as in the pseudo-D determination, the driving scene is divided into a driving driving scene (accelerator ON & torque up, accelerator ON & torque down) and a coast driving scene by accelerator operation. The primary calculated rotation speed Npri # is obtained by converting the secondary rotation speed Nsec from the secondary rotation sensor 90 into the input rotation speed of the variator 4 using the gear ratio RATIO of the variator 4.

In the case of drive acceleration driving scene (accelerator ON & torque up), when the function of the primary rotation sensor 80 is normal, as shown in the upper left frame of FIG. 9, the primary calculation rotation change gradient ΔNpri #, the turbine rotation change gradient ΔNt, and the primary rotation change Gradient ΔNpri has the same upward slope. On the other hand, when the primary rotation speed Npri from the primary rotation sensor 80 gradually decreases due to water entry or the like, the primary rotation change gradient ΔNpri changes from an upward-sloping gradient to a downward-sloping gradient as shown in the upper left frame of FIG. Transition. That is, the characteristic of the primary rotation speed (Npri) shown by the broken line in the upper left frame of FIG. 9 shifts to the characteristic of the primary rotation speed Npri shown by the alternate long and short dash line in the upper left frame of FIG.

Therefore, of the turbine rotation speed Nt, the primary rotation speed Npri, and the primary operation rotation speed Npri #, the primary rotation change gradient ΔNpri is different from the other two change gradients ΔNt and ΔNpri #. Then, the primary rotation change gradient ΔNpri moves in the opposite direction to the primary operation rotation change gradient ΔNpri #. Therefore, the primary rotation sensor 80 is diagnosed as having a malfunction.

In the case of drive deceleration running scene (accelerator ON & torque down), when the function of the primary rotation sensor 80 is normal, as shown in the central right frame of FIG. 9, the primary calculation rotation change gradient ΔNpri #, the turbine rotation change gradient ΔNt, and the primary rotation change Gradient ΔNpri has the same downward slope. On the other hand, when the primary rotation speed Npri from the primary rotation sensor 80 gradually increases due to pulse cracking or the like, the primary rotation change gradient ΔNpri changes from a downward-sloping gradient to an upward-sloping gradient as shown in the central right frame of FIG. Transition. That is, the characteristic of the primary rotation speed (Npri) shown by the broken line in the central right frame of FIG. 9 shifts to the characteristic of the primary rotation speed Npri indicated by the alternate long and short dash line in the central right frame of FIG.

Therefore, of the turbine rotation speed Nt, the primary rotation speed Npri, and the primary operation rotation speed Npri #, the primary rotation change gradient ΔNpri is different from the other two change gradients ΔNt and ΔNpri #. Then, the primary rotation change gradient ΔNpri moves in the opposite direction to the primary operation rotation change gradient ΔNpri #. Therefore, the primary rotation sensor 80 is diagnosed as having a malfunction.

In the case of a coast running scene by releasing the accelerator foot, when the function of the primary rotation sensor 80 is normal, as shown in the lower right frame of FIG. 9, the primary calculation rotation change gradient ΔNpri #, the turbine rotation change gradient ΔNt, and the primary rotation change gradient ΔNpri Has the same downward slope. On the other hand, when the primary rotation speed Npri from the primary rotation sensor 80 gradually increases due to pulse cracking or the like, the primary rotation change gradient ΔNpri changes from a downward-sloping gradient to an upward-sloping gradient as shown in the lower right frame of FIG. Transition. That is, the characteristic of the primary rotation speed (Npri) shown by the broken line in the lower right frame of FIG. 9 shifts to the characteristic of the primary rotation speed Npri shown by the one turning chain line in the lower right frame of FIG.

Therefore, of the turbine rotation speed Nt, the primary rotation speed Npri, and the primary operation rotation change gradient ΔNpri #, the primary rotation change gradient ΔNpri is different from the other two change gradients ΔNt and ΔNpri #. Then, the primary rotation speed Npri does not increase in the coast running scene due to the accelerator foot release operation. Therefore, the primary rotation sensor 80 is diagnosed as having a malfunction.

Next, the effect will be described.
In the clutch slip diagnosis device and the clutch slip diagnosis method of the belt type continuously variable transmission CVT of the first embodiment, the effects listed below can be obtained.

(1) The automatic transmission (belt type continuously variable transmission CVT) arranged between the driving drive source (engine 1) and the drive wheels 6 for traveling and the automatic transmission are provided by the driver in the traveling range (D range). , L range, R range) is engaged with the traveling clutch (forward clutch 31, reverse brake 32), and when the traveling clutch is selected, if a clutch rotation difference of a predetermined value or more occurs between the traveling clutches, it is simulated. The D state (pseudo-D state) means that the traveling clutch, which should be in the engaged state during traveling in the traveling range, that is, the D range, the R range, the L range, or the like, unintentionally enters the clutch slip engaged state. ) Is provided with a clutch slip diagnosis unit 8a.
In the clutch slip diagnosis device of this automatic transmission (belt type continuously variable transmission CVT), a drive source side rotation sensor (turbine rotation sensor 89) and a drive wheel side rotation sensor (primary rotation sensor) for detecting the clutch rotation difference of the traveling clutch. 80) is provided.
The clutch slip diagnosis unit 8a determines the magnitude relationship between the two rotation speed detection values and 2 when a rotation difference of a predetermined value or more occurs between the detection values (turbine rotation speed Nt, primary rotation speed Npri) from the two rotation speed sensors. When it is determined that the temporal change gradient relationship of the two rotation speed detection values corresponds to the torque transmission mode by the accelerator operation, it is determined that the pseudo-D state is satisfied.
Therefore, when a differential rotation occurs in the traveling clutch (forward clutch 31, reverse brake 32) with the traveling range (D range, L range, R range) selected, the differential rotation occurs due to a malfunction of the rotation sensor. It is possible to provide a clutch slip diagnosis device that prevents an erroneous determination that the above is a pseudo D state.

(2) The clutch slip diagnosis unit 8a has a predetermined value (first difference rotation threshold ΔN1) or more in the detected values (turbine rotation speed Nt, primary rotation speed Npri) from the two rotation sensors during the drive running by depressing the accelerator. When a rotation difference occurs, the drive source side rotation detection value (turbine rotation speed Nt) is larger than the drive wheel side rotation detection value (primary rotation speed Npri), and the change gradients ΔNt and ΔNpri of the two detection values are the ascending gradients. If there is a relationship, it is determined that the state is a pseudo D state.
Therefore, in addition to the effect of (1), in the drive acceleration driving scene, it is possible to eliminate the erroneous determination due to the rotation sensor function abnormality and perform the pseudo D determination with high accuracy.

(3) The clutch slip diagnosis unit 8a has a predetermined value (first difference rotation threshold ΔN1) or more in the detected values (turbine rotation speed Nt, primary rotation speed Npri) from the two rotation sensors during the drive running by the accelerator return operation. When a rotation difference occurs, the drive source side rotation detection value (turbine rotation speed Nt) is larger than the drive wheel side rotation detection value (primary rotation speed Npri), and the change gradients ΔNt and ΔNpri of the two detection values are the downward slopes. If there is a relationship, it is determined that the state is a pseudo D state.
Therefore, in addition to the effect of (1) or (2), it is possible to eliminate the erroneous determination due to the rotation sensor function abnormality in the drive deceleration running scene and perform the pseudo D determination with high accuracy.

(4) The clutch slip diagnosis unit 8a has a predetermined value (third difference rotation threshold ΔN3) or more in the detected values (turbine rotation speed Nt, primary rotation speed Npri) from the two rotation sensors during coast running by releasing the accelerator foot. When the rotation difference of is generated, the rotation detection value on the drive wheel side (primary rotation speed Npri) is larger than the rotation detection value on the drive source side (turbine rotation speed Nt), and the change gradients ΔNt and ΔNpri of the two detection values are downward gradients. If there is a relationship of, it is determined that the state is a pseudo D state.
Therefore, in addition to the effects of (1) to (3), it is possible to eliminate the erroneous determination due to the rotation sensor function abnormality in the coastal driving scene and perform the pseudo D determination with high accuracy.

(5) The clutch slip diagnosis unit 8a rotates at a value (first difference rotation threshold ΔN1 or third difference rotation threshold ΔN3) or more than the values detected from the two rotation sensors (turbine rotation speed Nt, primary rotation speed Npri). If there is a difference, if it is determined that the relationship between the two detected values over time and the gradient relationship does not correspond to the torque transmission mode by accelerator operation, the rotation sensor (turbine rotation sensor 89, primary rotation sensor 80) malfunctions. Rotation sensor function error diagnosis is performed.
Therefore, in addition to the effects of (1) to (4), when the rotation sensor (turbine rotation sensor 89, primary rotation sensor 80) has a function abnormality that raises or lowers the detected value, the rotation sensor function abnormality without delay. The diagnostic process can be started.

(6) When the clutch slip diagnosis unit 8a executes the functional abnormality diagnosis of the rotation sensor (turbine rotation sensor 89, primary rotation sensor 80), the drive source is set to two detected values (turbine rotation speed Nt, primary rotation speed Npri). When three or more rotation detection values including the detection values indicating the rotation of at least one of the side and the drive wheel side are used, and the change gradient of one rotation detection value is different from the change gradient of the other rotation detection value. , The rotation sensor of a different relationship (turbine rotation sensor 89 or primary rotation sensor 80) is diagnosed as malfunctioning.
Therefore, in addition to the effect of (5), at least three rotation detection values are used, and it is only necessary to judge whether or not the gradient of one detection value is out of the group with the other detection values. Accurate diagnosis of sensor function abnormality can be performed.

(7) An automatic transmission (belt type continuously variable transmission CVT) arranged between the driving drive source (engine 1) and the drive wheels 6 and
The automatic transmission includes a traveling clutch (forward clutch 31, reverse brake 32) that is engaged in a state where the traveling range (D range, L range, R range) is selected by the driver.
In this automatic transmission, a clutch slip diagnosis method for determining a pseudo-D state when a clutch rotation difference of a predetermined value or more occurs in a traveling clutch (forward clutch 31, reverse brake 32) while selecting a traveling range. The clutch rotation difference of the traveling clutch (forward clutch 31, reverse brake 32) is detected from the rotation speed detection value on the drive source side for traveling and the rotation speed detection value on the drive wheel side.
When the clutch rotation difference is equal to or greater than a predetermined value, it is determined that the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values correspond to the torque transmission mode by the accelerator operation. , It is determined that the state is a pseudo D state.
Therefore, when a differential rotation occurs in the traveling clutch (forward clutch 31, reverse brake 32) with the traveling range (D range, L range, R range) selected, the differential rotation occurs due to a malfunction of the rotation sensor. It is possible to provide a clutch slip diagnosis method for preventing an erroneous determination that the above is a pseudo D state.

The clutch slip diagnosis device and the clutch slip diagnosis method for the automatic transmission of the present invention have been described above based on the first embodiment. However, the specific configuration is not limited to the first embodiment, and design changes and additions are permitted as long as the gist of the invention according to each claim is not deviated from the claims.

In Example 1, when the magnitude relationship and the time-dependent change gradient relationship are determined using two detected values (Nt, Npri) as a pseudo-D determination, the time-dependent change gradient relationship is determined using the change gradients ΔNt and ΔNpri. showed that. However, as a pseudo-D judgment, the detection values (calculated values) on the clutch input side and the clutch output side are increased in addition to the two detected values, and the temporal change gradient relationship is replaced with the magnitude relation of the detected values (calculated values) for the judgment. You may do so.

In the first embodiment, as the rotation sensor function abnormality diagnosis, there is a case where the function abnormality of the turbine rotation sensor 89 is diagnosed using three detection values (Nt, Npri, Ne), and two detection values (Nt, Npri) and one. An example of diagnosing a functional abnormality of the primary rotation sensor 80 using one calculated value (Npri #) is shown. However, as the rotation sensor function abnormality diagnosis, regardless of whether the turbine rotation sensor function abnormality diagnosis or the primary rotation sensor function abnormality diagnosis, three detected values (Nt, Npri, Ne) and one calculated value (Npri #) are used. A total of four values may be used to diagnose the malfunction of the turbine rotation sensor or the primary rotation sensor.

In Example 1, an example is shown in which the clutch slip diagnosis device and the clutch slip diagnosis method of the present invention are applied to an engine vehicle equipped with a belt-type continuously variable transmission CVT as an automatic transmission. However, the clutch slip diagnosis device of the present invention may be applied as an automatic transmission to a vehicle equipped with a stepped transmission called a step AT, a vehicle equipped with a continuously variable transmission with an auxiliary transmission, or the like. Further, the applicable vehicle is not limited to an engine vehicle, but can also be applied to a hybrid vehicle in which an engine and a motor are mounted as a driving drive source, an electric vehicle in which a motor is mounted as a driving drive source, and the like. Here, when applied to a vehicle equipped with a stepped transmission called a step AT, the starting clutch engaged during the N → D select operation or the N → R select operation is treated as a traveling clutch.

1 Engine (driving drive source)
CVT belt type continuously variable transmission (automatic transmission)
2 Torque converter 3 Forward / backward switching mechanism 31 Forward clutch (traveling clutch)
32 Reverse brake (running clutch)
4 Variator 5 Final deceleration mechanism 6 Drive wheel 7 Hydraulic control unit 8 CVT control unit 8a Clutch slip diagnosis unit 12 Engine rotation sensor 80 Primary rotation sensor 84 Inhibita switch 89 Turbine rotation sensor 90 Secondary rotation sensor 91 Select lever

Claims (7)

An automatic transmission located between the driving source for driving and the driving wheels,
A traveling clutch that is possessed by the automatic transmission and is engaged in a state where the traveling range is selected by the driver.
During the selection of the traveling range, a clutch slip diagnosis unit that determines that the traveling clutch is in a pseudo-D state when a clutch rotation difference of a predetermined value or more occurs.
In the clutch slip diagnostic device of an automatic transmission equipped with
A drive source side rotation sensor and a drive wheel side rotation sensor for detecting the clutch rotation difference of the traveling clutch are provided.
When a rotation difference of a predetermined value or more occurs between the detection values from the two rotation sensors, the clutch slip diagnosis unit determines the magnitude relationship between the two rotation speed detection values and the time-dependent change of the two rotation speed detection values. A clutch slip diagnostic device for an automatic transmission, characterized in that when it is determined that the gradient relationship corresponds to a torque transmission mode by accelerator operation, it is determined to be in a pseudo-D state. In the clutch slip diagnostic apparatus of the automatic transmission according to claim 1,
When the clutch slip diagnosis unit is driving while driving by depressing the accelerator, when a rotation difference of a predetermined value or more occurs between the detection values from the two rotation sensors, the rotation detection value on the drive source side is based on the rotation detection value on the drive wheel side. A clutch slip diagnostic device for an automatic transmission, characterized in that, when the change gradients of the two detected values are in an ascending gradient relationship, it is determined that the state is a pseudo D state. In the clutch slip diagnostic apparatus of the automatic transmission according to claim 1 or 2.
When the clutch slip diagnosis unit is driving while driving by the accelerator return operation, when a rotation difference of a predetermined value or more occurs between the detection values from the two rotation sensors, the rotation detection value on the drive source side is based on the rotation detection value on the drive wheel side. A clutch slip diagnostic device for an automatic transmission, characterized in that, when the change gradients of the two detected values are in a downward gradient relationship, it is determined that the state is a pseudo D state. In the clutch slip diagnostic apparatus of the automatic transmission according to any one of claims 1 to 3, the present invention
When the clutch slip diagnosis unit is traveling on the coast by releasing the accelerator foot and a rotation difference of a predetermined value or more occurs between the detection values from the two rotation sensors, the rotation detection value on the drive wheel side is the rotation detection value on the drive source side. A clutch slip diagnostic device for an automatic transmission, which is larger than the above and determines that it is in a pseudo-D state when the change gradients of the two detected values are in a downward gradient relationship. In the clutch slip diagnostic apparatus of the automatic transmission according to any one of claims 1 to 4.
In the clutch slip diagnosis unit, when a rotation difference of a predetermined value or more occurs between the detected values from the two rotation sensors, the temporal change gradient relationship of the two detected values does not correspond to the torque transmission mode by the accelerator operation. A clutch slip diagnostic device for an automatic transmission, which is characterized by executing a rotation sensor function abnormality diagnosis for diagnosing a rotation sensor function abnormality when it is determined. In the clutch slip diagnostic apparatus of the automatic transmission according to claim 5.
When executing the functional abnormality diagnosis of the rotation sensor, the clutch slip diagnosis unit has three or more rotations obtained by adding a detection value indicating rotation of at least one of the drive source side and the drive wheel side to the two detection values. When the change gradient of one rotation detection value is different from the change gradient of another rotation detection value using the detected value, the rotation sensor having a different relationship diagnoses the malfunction. Clutch slip diagnostic device. An automatic transmission located between the driving source for driving and the driving wheels,
In an automatic transmission including the traveling clutch which is provided in the automatic transmission and is engaged in a state where a traveling range is selected by a driver.
It is a clutch slip diagnosis method of an automatic transmission that determines that it is in a pseudo-D state when a clutch rotation difference of a predetermined value or more occurs in the traveling clutch during the selection of the traveling range.
The clutch rotation difference of the traveling clutch is detected from the rotation speed detection value on the drive source side for traveling and the rotation speed detection value on the drive wheel side.
When the clutch rotation difference is equal to or greater than a predetermined value, it is determined that the magnitude relationship between the two rotation speed detection values and the temporal change gradient relationship between the two rotation speed detection values correspond to the torque transmission mode by the accelerator operation. A method for diagnosing clutch slip of an automatic transmission, which determines that the vehicle is in a pseudo-D state.

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