JP2017155779A - Controller of vehicular automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller of a vehicular automatic transmission capable of suppressing an excessive rotation state of an internal member of the vehicular automatic transmission in a case where a solenoid valve of the vehicular automatic transmission is broken.SOLUTION: When an input shaft rotational frequency Nin is below an input shaft abnormal rotational frequency threshold NA set on a lower rotational frequency side than a normal input shaft rotational frequency Nin0 in a case where a transmission ratio corresponding to a predetermined shift stage is obtained, supply of engagement hydraulic pressure from all solenoid valves is stopped to make a vehicular automatic transmission 22 into a neutral state, thereby suppressing an excessive rotation state of an internal member in a vehicular automatic transmission 22.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a control device for an automatic transmission for a vehicle in which a plurality of gear stages are selectively formed by engaging a hydraulic friction engagement device.

  In a vehicular automatic transmission having a plurality of hydraulic friction engagement devices to which engagement hydraulic pressures are respectively supplied from a plurality of solenoid valves, a predetermined gear stage is controlled by controlling a predetermined number of solenoid valves among the plurality of solenoid valves. There is known a control device for an automatic transmission for a vehicle in which is established selectively. For example, this is the control device for an automatic transmission for a vehicle described in Patent Document 1.

JP 2011-106656 A

  In the technique of the above-mentioned Patent Document 1, a failure detection unit that detects a broken solenoid valve among a plurality of solenoid valves is provided in a control device for an automatic transmission for a vehicle, and when a broken solenoid valve is detected, Shifting to a gear stage formed by a solenoid valve other than the solenoid valve. At this time, if there is a possibility of sudden deceleration, the vehicle automatic transmission is kept in a neutral state (neutral state) until the vehicle speed drops to a predetermined value. However, in Patent Document 1, since the vehicle automatic transmission is shifted after the failure detection unit detects the failure of the solenoid valve, the input shaft rotational speed and output of the vehicle automatic transmission due to the failure of the solenoid valve. An automatic speed change for a vehicle is caused by an excessively high speed state in which the rotational speed difference occurs in the shaft rotational speed and the input shaft rotational speed is higher than the synchronous rotational speed or an excessively low rotational speed in which the input shaft rotational speed is lower than the synchronous rotational speed. When an internal member of the machine, for example, an internal member such as a pinion is over-rotated, if the internal member over-rotation is caused by an increase in the input shaft rotational speed, an engine fuel cut is performed to stop fuel supply. By suppressing the input shaft rotational speed to a normal rotational speed, it is possible to avoid over-rotation of the internal member. However, when the overspeed of the internal member is caused by the decrease of the input shaft speed, the overspeed cannot be avoided even if the engine fuel cut is executed. Such over-rotation of the internal member can affect the durability of the automatic transmission.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to provide an over-rotation state of an internal member of a vehicle automatic transmission when a solenoid valve of the vehicle automatic transmission fails. It is providing the control apparatus of the automatic transmission for vehicles which suppresses.

  The gist of the present invention is that: (a) in an automatic transmission for a vehicle having a plurality of hydraulic friction engagement devices to which engagement hydraulic pressures are respectively supplied from a plurality of solenoid valves, A control device for an automatic transmission for a vehicle that controls a predetermined number of solenoid valves to selectively establish a predetermined shift speed, and (b) an input for calculating an input shaft rotational speed of the automatic transmission for the vehicle A shaft rotation number calculation unit, (c) an output shaft rotation number calculation unit for calculating an output shaft rotation number of the vehicle automatic transmission, and (d) a gear ratio corresponding to the predetermined gear stage is obtained. An input shaft abnormal rotational speed setting unit for setting an input shaft abnormal rotational speed threshold value set in advance on the lower rotational speed side than the input shaft rotational speed based on the output shaft rotational speed; and (e) calculating the input shaft rotational speed. The input shaft rotation speed calculated by the unit An abnormality determination unit that determines whether or not the input shaft is below the abnormal rotational speed; and (f) when the abnormality determination unit determines that the input shaft rotational speed is less than the input shaft abnormal rotational speed. Is provided with an abnormal-time control unit that disengages all of the plurality of hydraulic friction engagement devices that establish the gear position at that time.

  In this case, the input shaft rotational speed is set to a lower rotational speed side than the normal input shaft rotational speed when the gear ratio corresponding to the predetermined shift speed is obtained. When the abnormality determination unit determines that the vehicle speed is less than the threshold value, all of the hydraulic friction engagement devices that establish the gear position at that time are disengaged, and thus the vehicle automatic transmission is Since it is in the neutral state, over-rotation of the internal member of the vehicle automatic transmission can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the schematic structure of the vehicle to which this invention is applied, and is a figure explaining the principal part of the control system in a vehicle. It is a skeleton diagram explaining a torque converter and an automatic transmission for vehicles. It is an operation | movement chart explaining the combination of the instruction | indication of the engagement to the solenoid valve at the time of forming the gear stage of the automatic transmission for vehicles, and the combination of the action | operation of an engagement apparatus. It is a circuit diagram which shows an example of the principal part of the hydraulic control circuit regarding the linear solenoid valve etc. which control the action | operation of each hydraulic actuator of a clutch and a brake. It is the schematic which shows the relationship between input-shaft rotational speed and output-shaft rotational speed. It is a flowchart explaining the control operation | movement for suppressing the overspeed state, when the principal part of the control action of an electronic controller, ie, the internal member in the automatic transmission for vehicles, will be in the overspeed state.

  An embodiment of the present invention will be described below with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and a diagram illustrating a main part of a control system in the vehicle 10. In FIG. 1, a vehicle 10 includes an engine 12 such as a gasoline engine or a diesel engine that functions as a driving power source for traveling, a driving wheel 14, and a power transmission device 16 provided between the engine 12 and the driving wheel 14. And. The power transmission device 16 is connected to a known torque converter 20 and a torque converter 20 as a fluid transmission device connected to the engine 12 in a transmission case 18 (hereinafter referred to as a case 18) as a non-rotating member attached to the vehicle body. A connected vehicle automatic transmission 22 (hereinafter referred to as an automatic transmission 22), a propeller shaft 26 connected to an output shaft 24 which is an output rotating member of the automatic transmission 22, and a differential connected to the propeller shaft 26. A gear unit (differential gear) 28 and a pair of axles 30 connected to the differential gear unit 28 are provided. In the power transmission device 16 configured as described above, the power (or torque) of the engine 12 is 1 through the torque converter 20, the automatic transmission 22, the propeller shaft 26, the differential gear device 28, the axle 30 and the like in order. It is transmitted to the pair of drive wheels 14.

  FIG. 2 is a skeleton diagram illustrating the torque converter 20 and the automatic transmission 22. The torque converter 20, the automatic transmission 22 and the like are substantially symmetrical with respect to the center line (axial center RC), and the lower half of the center line is omitted in FIG. 2 is a rotational axis of the engine 12 and the torque converter 20.

  In FIG. 2, the torque converter 20 is disposed concentrically with the shaft center RC, and is connected to a pump impeller 20 p connected to the engine 12 and a transmission input shaft 32 that is an input rotating member of the automatic transmission 22. The turbine impeller 20t is provided. A mechanical oil pump 34 is connected to the pump impeller 20p. As a result, the mechanical oil pump 34 is rotationally driven by the engine 12 to control the shift of the automatic transmission 22 and to supply lubricating oil to each part of the power transmission path of the power transmission device 16. Generate hydraulic pressure.

  The automatic transmission 22 constitutes a part of a power transmission path from the engine 12 to the drive wheels 14, and a gear ratio (transmission ratio) is obtained by selectively engaging one of a plurality of friction engagement devices. It is a planetary gear type multi-stage transmission that functions as a stepped automatic transmission in which a plurality of different gear stages (shift stages) are formed. For example, it is a stepped transmission that performs a so-called clutch-to-clutch shift that is often used in known vehicles. The automatic transmission 22 includes a single pinion type first planetary gear unit 36, a single pinion type second planetary gear unit 38 and a double pinion type third planetary gear unit 40 configured in a Ravigneaux type, A pinion type fourth planetary gear device 42 is provided on the same axis (on the axis RC), and the rotation of the input shaft 32 is shifted and output from the output shaft 24.

  As is well known, the first planetary gear device 36, the second planetary gear device 38, the third planetary gear device 40, and the fourth planetary gear device 42 are a sun gear (S1, S2, S3, S4), a pinion gear. (P1, P2, P3, P4) are supported by a carrier (CA1, CA2, CA3, CA4) that supports rotation and revolution, and a ring gear (R1, R2, R3, R4) that meshes with the sun gear via a pinion gear. A rotating element (rotating member) is configured. Each of these three rotating elements is partly mutually or directly (or selectively) via frictional engagement devices (clutches C1, C2, C3, C4 and brakes B1, B2). It is connected to the transmission input shaft 32, the case 18, or the output shaft 24.

  The clutches C1, C2, C3, and C4 and the brakes B1 and B2 (hereinafter referred to simply as the clutch C, the brake B, or the engaging device unless otherwise distinguished) are known in a known automatic transmission for vehicles. A hydraulic friction engagement device that is often used, and includes a wet multi-plate clutch and brake pressed by a hydraulic actuator, a band brake tightened by a hydraulic actuator, and the like. The clutch C and the brake B configured in this way have their torque capacities depending on the hydraulic pressure from the linear solenoid valves SL1-SL6 and the like included in the hydraulic control circuit 50 (see FIGS. 1 and 4) provided in the automatic transmission 22. (Ie, engagement force) is changed to switch between engagement and release.

  By controlling the engagement and disengagement of the clutch C and the brake B by the hydraulic control circuit 50, as shown in the operation chart of FIG. 3, each of the 10 forward speeds according to the accelerator operation of the driver, the vehicle speed V, etc. A gear stage is formed. “1st” − “10th” in FIG. 3 means the first gear to the tenth gear as the forward gears, respectively, and the gear ratio γ of the automatic transmission 22 corresponding to each gear (= The transmission input shaft rotational speed Nin / output shaft rotational speed Nout) is the gear ratio of the first planetary gear device 36, the second planetary gear device 38, the third planetary gear device 40, and the fourth planetary gear device 42 (= The number of teeth of the sun gear / the number of teeth of the ring gear). “Rev” means reverse gear.

  The operation chart of FIG. 3 summarizes the relationship between the gears and solenoid instructions for the linear solenoid valves SL1 to SL6, and the relationship between the gears and the operating states of the engagement devices. In FIG. 3, “◯” indicates the output of the engagement command signal for operating (turning on) the linear solenoid valves SL1-SL6 and the engagement of the engagement device, and the blank indicates the non-output of the engagement command signal and the engagement device. Represents non-engagement (release). As described above, the automatic transmission 22 is engaged with the predetermined engagement device by supplying the engagement hydraulic pressure to the predetermined engagement device by the operation of the predetermined linear solenoid valves SL1-SL6 and the like. This is an automatic transmission in which gear stages are formed alternatively (selectively).

  Returning to FIG. 1, the vehicle 10 is provided with an electronic control unit 80 including a control unit for the automatic transmission 22 related to, for example, shift control of the automatic transmission 22. Therefore, FIG. 1 is also a diagram showing an input / output system of the electronic control device 80, and is a functional block diagram for explaining a main part of a control function by the electronic control device 80. The electronic control unit 80 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like, and the CPU uses a temporary storage function of the RAM according to a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 80 is configured to execute output control of the engine 12, shift control of the automatic transmission 22, and the like, and an electronic control unit for engine output control, an electronic control unit for hydraulic control, and the like as necessary. It is divided into two parts.

  The electronic control unit 80 includes various actual values (for example, engine rotational speed Ne) based on detection signals from various sensors (for example, various rotational speed sensors 70, 72, 74, accelerator opening sensor 76, throttle sensor 78, etc.) provided in the vehicle 10. (Rpm), transmission input shaft rotational speed Nin (rpm) which is turbine rotational speed Nt (rpm), output shaft rotational speed Nout (rpm) corresponding to vehicle speed V, accelerator opening θacc (%), throttle valve opening θth (%), etc.) are respectively supplied. The electronic control unit 80 also outputs an engine output control command signal Se for output control of the engine 12, a hydraulic control command signal Sp for hydraulic control related to the shift of the automatic transmission 22, and the like. The hydraulic control command signal Sp is, for example, an engagement command signal for engaging a predetermined engagement device, and the engagement hydraulic pressures Pc1, Pc2 supplied to the hydraulic actuators ACT1-ACT6 of the clutch C and the brake B, for example. , Pc3, Pc4, Pb1, and Pb2 are engagement command signals for operating the respective linear solenoid valves SL1-SL6, and are output to the hydraulic control circuit 50 (that is, the predetermined linear solenoid valves SL1-SL6).

  FIG. 4 is a circuit diagram showing a main part of the hydraulic control circuit 50 related to the linear solenoid valves SL1-SL6 and the like that control the operation of the hydraulic actuators ACT1-ACT6 of the clutch C and the brake B. In FIG. 4, the hydraulic control circuit 50 includes a hydraulic pressure supply device 52 and linear solenoid valves SL1-SL6.

  The hydraulic pressure supply device 52 adjusts the line hydraulic pressure PL using the hydraulic pressure generated by the oil pump 34 as a source pressure, for example, a relief type primary regulator valve 54, and an engine load (for example, engine torque Te) expressed by a throttle valve opening θth and the like. And the linear hydraulic valve SLT for supplying the signal pressure Pslt to the primary regulator valve 54 in order to adjust the line hydraulic pressure PL in accordance with the transmission hydraulic input torque Tat and the like, and the modulator hydraulic pressure PM is constant with the line hydraulic pressure PL as the source pressure. A modulator valve 56 for adjusting the pressure to a value and a manual valve 58 for switching the oil path mechanically or electrically in conjunction with the switching operation of the shift lever 60 are provided. The manual valve 58 outputs the input line oil pressure PL as the forward oil pressure (D range pressure) PD when the shift lever 60 is in the forward travel operation position D, and when the shift lever 60 is in the reverse travel operation position R, The input line oil pressure PL is output as a reverse oil pressure (R range pressure) PR. Further, when the shift lever 60 is in the neutral operation position N or the parking operation position P, the manual valve 58 cuts off the hydraulic pressure output and guides the forward hydraulic pressure PD and the reverse hydraulic pressure PR to the discharge side. Thus, the hydraulic pressure supply device 52 outputs the line hydraulic pressure PL, the modulator hydraulic pressure PM, the forward hydraulic pressure PD, and the reverse hydraulic pressure PR.

  The hydraulic actuators ACT1, ACT4, and ACT5 of the clutches C1, C4, and the brake B1 are supplied with engagement hydraulic pressures Pc1, Pc4, and Pb1 that are regulated by the linear solenoid valves SL1, SL4, and SL5, respectively, using the forward hydraulic pressure PD as a source pressure. Is done. Further, the hydraulic actuators ACT2, ACT3, ACT6 of the clutches C2, C3, B2 have engagement hydraulic pressures Pc2, Pc3, Pb2 regulated by the linear solenoid valves SL2, SL3, SL6, respectively, using the line hydraulic pressure PL as a source pressure. Supplied. The linear solenoid valves SL1 to SL6 basically have the same configuration, and are individually excited, de-energized, and controlled by the electronic control unit 80.

  Returning to FIG. 1, the electronic control unit 80 includes an input shaft rotational speed calculation unit, that is, an input shaft rotational speed calculation unit 82, an output shaft rotational speed calculation unit, that is, an output shaft rotational speed calculation unit 84, an input shaft abnormal rotational speed threshold setting unit, An input shaft abnormal rotation speed threshold setting unit 86, an abnormality determination unit, that is, an abnormality determination unit 88, an abnormal time control unit, that is, an abnormal time control unit 90, and a shift control unit, that is, a shift control unit 92 are functionally provided.

  The shift control unit 92 applies the actual vehicle speed V and the accelerator opening Acc to a predetermined relationship (shift map, shift diagram) with the vehicle speed V and the accelerator opening Acc as variables normally (normally). A hydraulic pressure control command signal Sp (engagement command signal) is used as a shift command for engaging the engagement device involved in the shift of the automatic transmission 22 so as to obtain the determined predetermined forward gear stage. Output to the control circuit 50. In accordance with the hydraulic control command signal Sp, the linear solenoid valves SL1 to SL6 in the hydraulic control circuit 50 are driven (actuated) so that the shift of the automatic transmission 22 is executed. The hydraulic actuators ACT1-ACT6 are actuated.

  The input shaft rotational speed calculation unit 82 calculates the input shaft rotational speed Nin (rpm) of the input shaft 32 at a predetermined gear position based on the pulse signal output from the input shaft rotational speed sensor 72 provided in the vehicle 10. The output shaft rotational speed calculation unit 84 calculates the output shaft rotational speed Nout (rpm) of the output shaft 24 at a predetermined gear position based on the pulse signal output from the output shaft rotational speed sensor 74 provided in the vehicle 10.

  The input shaft abnormal rotation speed threshold value setting unit 86 sets the input shaft abnormal rotation speed threshold value NA to a predetermined value, for example, a value greater than the synchronous rotation speed when the gear ratio corresponding to the current vehicle speed is obtained, that is, the normal input shaft rotation speed Nin0. It is set in advance to the low rotation speed side of about 10% of the synchronous rotation speed or 1000 rpm. For example, at the shift stage “1st”, an abnormal rotation threshold map A1 (not shown) when SL1 fails, an abnormal rotation threshold map A2 (not shown) when SL2 fails, and an abnormal rotation threshold map (not shown) when SL6 fails Use A6. In each abnormal rotation threshold map, an area indicating an abnormal state is set in the relationship between the input shaft rotation speed Nin and the output shaft rotation speed Nout, and if an abnormality occurs at the shift stage “1st”, an abnormality is generated. A threshold that is determined as an abnormal state in any map by adding the rotation threshold maps A1, A2, and A6 is defined as an abnormality determination threshold. Then, an abnormality determination threshold when the input shaft rotational speed Nin is on the lower rotational speed side than the normal input shaft rotational speed Nin0 is set as the input shaft abnormal rotational speed threshold NA.

  FIG. 5 is a schematic diagram showing the relationship between the input shaft rotational speed Nin and the output shaft rotational speed Nout at a predetermined gear position. The vertical axis in FIG. 5 represents the input shaft rotational speed Nin, and the horizontal axis represents the output shaft rotational speed Nout. The gear speed synchronous speed shown in FIG. 5 is obtained when the ratio (Nin / Nout) between the input shaft speed Nin and the output shaft speed Nout matches the speed ratio of the predetermined speed, that is, the normal input. The relationship between the shaft rotational speed Nin0 and the output shaft rotational speed Nout0 is shown. The two regions indicated by hatching in FIG. 5 indicate internal member over-rotation regions where internal members such as pinions in the automatic transmission 22 are determined to be in an over-rotation state exceeding the allowable range at a predetermined gear position. Yes. Here, the input shaft abnormal rotation speed threshold value NA is represented by a boundary between the internal member over-rotation region on the side lower than the gear speed synchronous rotation speed and the region where no abnormality occurs in the internal member of the vehicle automatic transmission 22.

  When the input shaft abnormal rotational speed threshold NA is calculated, the input shaft abnormal rotational speed threshold setting unit 86 outputs the output shaft rotational speed calculated by the output shaft rotational speed calculating unit 84 based on the input shaft abnormal rotational speed threshold NA. From Nout, an input shaft abnormal rotational speed NAd for determining an abnormality in the input shaft rotational speed at the actual vehicle speed and gear position is calculated.

  The abnormality determination unit 88 determines whether or not the input shaft rotational speed Nin calculated by the input shaft rotational speed calculation unit 82 is less than the input shaft abnormal rotational speed NAd calculated by the input shaft abnormal rotational speed threshold setting unit 86. To do. That is, the abnormality determination unit 88 determines whether or not the input shaft rotational speed Nin is less than the input shaft abnormal rotational speed NAd and the internal member in the vehicle automatic transmission 22 is in an abnormal state in which it is overrotating. Yes.

  When the abnormality determining unit 88 determines that the input shaft rotational speed Nin is less than the input shaft abnormal rotational speed NAd, the abnormal-time control unit 90 establishes a plurality of hydraulic frictional units that establish the gear stage at that time. In order to disengage the combined device, control is performed to stop the supply of the engagement hydraulic pressure to the hydraulic friction engagement device for all of the plurality of linear solenoid valves that supply the engagement hydraulic pressure to them. Here, when a failure occurs in any of the linear solenoid valves SL1 to SL6 that supply the engagement hydraulic pressure to the hydraulic friction engagement device, the engagement hydraulic pressure is supplied from the failed linear solenoid valve to the hydraulic friction engagement device. Accordingly, the vehicle automatic transmission 22 is not in a normal engagement state but is in an abnormal engagement state. For example, as shown in FIG. 5, when the input shaft rotation speed Nin of the vehicle automatic transmission 22 becomes less than the input shaft abnormal rotation speed threshold value NA due to a failure of the linear solenoid valve, the interior of the vehicle automatic transmission 22 such as a pinion The member is over-rotated. In order to avoid this state, the abnormality control unit 90 releases all of the plurality of linear solenoid valves that supply the engagement hydraulic pressure to the plurality of hydraulic friction engagement devices that establish the gear stage at that time. The instruction is executed to stop the supply of the engagement hydraulic pressure to the hydraulic friction engagement device, and the vehicle automatic transmission 22 is set to the neutral state. When the overspeed state of the internal member in the vehicular automatic transmission 22 is avoided by setting the vehicular automatic transmission 22 to the neutral state, the abnormal time control unit 90 stops executing the OFF instruction to the linear solenoid valve. To do.

  FIG. 6 is a flowchart for explaining a control operation for suppressing the overspeed state when the main part of the control operation of the electronic control unit 80, that is, when the internal member of the vehicle automatic transmission 22 is in the overspeed state. Yes, it is executed repeatedly.

  In a step (hereinafter, step is omitted) S10 corresponding to the input shaft rotational speed calculation unit 82, the input shaft rotational speed Nin of the input shaft 32 is calculated based on the pulse signal from the input shaft rotational speed sensor 72 provided in the vehicle 10. Is done. Subsequently, in S20 corresponding to the output shaft rotational speed calculation unit 84, the output shaft rotational speed Nout of the output shaft 24 is calculated based on the pulse signal from the output shaft rotational speed sensor 74 provided in the vehicle 10.

  Next, in S30 corresponding to the input shaft abnormal rotation speed threshold value setting unit 86, the input shaft rotation speed Nin0 at the normal time corresponding to the actual gear speed ratio, that is, lower than the gear speed synchronous rotation speed, for example, by about 1000 rpm. Among the values on the rotation speed side, an input shaft abnormal rotation speed threshold value NA set to a value corresponding to the current vehicle, that is, the output shaft rotation speed Nout is set. Based on the input shaft abnormal rotational speed threshold value NA, the input shaft abnormal rotational speed NAd in an abnormal state is calculated from the output shaft rotational speed Nout calculated by the output shaft rotational speed calculation unit 84.

  Next, in S40 corresponding to the abnormality determination unit 88, it is determined whether or not the input shaft rotational speed Nin calculated in S10 is less than the input shaft abnormal rotational speed NAd calculated in S30. When the input shaft rotational speed Nin is not less than the input shaft abnormal rotational speed NAd, this routine is terminated. However, if the input shaft rotational speed Nin is less than the input shaft abnormal rotational speed NAd, S50 is executed.

  In S50 corresponding to the abnormal time control unit 90, a plurality of engagement hydraulic pressures are supplied to a plurality of hydraulic friction engagement devices that establish a shift stage when the input shaft rotational speed Nin is less than the input shaft abnormal rotational speed NAd. Control for stopping the supply of the engagement hydraulic pressure to the hydraulic friction engagement device is performed for all the linear solenoid valves. Specifically, when it is determined that the input shaft rotational speed Nin is less than the input shaft abnormal rotational speed NAd, that is, when it is determined that the internal member in the vehicle automatic transmission 22 is in the overspeed state, the abnormal time control unit When the vehicle automatic transmission 22 performs an OFF instruction to release all of the plurality of linear solenoid valves that supply the engagement hydraulic pressure to the plurality of hydraulic friction engagement devices that establish the gear stage at that time, the vehicle automatic transmission 22 Neutral state. When the over-rotation state of the internal member in the vehicle automatic transmission 22 is avoided, the OFF instruction to the linear solenoid valve is stopped. Thereafter, this routine is terminated.

  Thus, according to the present embodiment, the input shaft rotational speed Nin is on the lower rotational speed side than the normal input shaft rotational speed Nin0, that is, the synchronous rotational speed when the gear ratio corresponding to the predetermined gear stage is obtained. When the abnormality determination unit 88 determines that the input shaft abnormal rotation speed threshold NAd is less than the set input shaft abnormal rotation speed threshold NAd, a plurality of engagement hydraulic pressures are supplied to the hydraulic friction engagement device that establishes the gear stage at that time. The supply of engagement hydraulic pressure from all the linear solenoid valves is stopped by the abnormality control unit 90, so that the vehicle automatic transmission 22 is brought into a neutral state, whereby the internal member in the vehicle automatic transmission 22 is over-rotated. And the durability of the vehicle automatic transmission 22 is ensured.

  As mentioned above, although the Example of this invention was described based on drawing, this invention is applied also to another aspect.

  For example, in the above-described embodiment, the engagement hydraulic pressure is applied to the plurality of hydraulic friction engagement devices that establish the shift stage when the input shaft rotational speed Nin is less than the input shaft abnormal rotational speed NAd in the abnormality control unit 90. However, the present invention is not limited to this, and an OFF instruction for releasing all the linear solenoid valves SL1 to SL6 included in the hydraulic control circuit 50 may be issued.

  It should be noted that the above description is merely an embodiment, and other examples are not illustrated. However, the present invention is implemented in variously modified and improved modes based on the knowledge of those skilled in the art without departing from the spirit of the present invention. Can do.

10: Vehicle 22: Vehicle automatic transmission 82: Input shaft rotational speed calculation unit 84: Output shaft rotational speed calculation unit 86: Input shaft abnormal rotational speed threshold value setting unit 88: Abnormality determination unit 90: Control unit during abnormality Nin: Input Shaft rotational speed Nout: Output shaft rotational speed NA: Input shaft abnormal rotational speed threshold NAd: Input shaft abnormal rotational speed

Claims (1)

In a vehicular automatic transmission having a plurality of hydraulic friction engagement devices to which engagement hydraulic pressures are respectively supplied from a plurality of solenoid valves, a predetermined number of solenoid valves among the plurality of solenoid valves are controlled to achieve a predetermined speed change. A control device for an automatic transmission for a vehicle in which a stage is selectively established,
An input shaft rotational speed calculation unit for calculating an input shaft rotational speed of the vehicle automatic transmission;
An output shaft rotational speed calculation unit for calculating the output shaft rotational speed of the vehicle automatic transmission;
An input shaft abnormality in which an input shaft abnormal rotation speed threshold value set in advance on the lower rotation speed side than the input shaft rotation speed when a gear ratio corresponding to the predetermined gear stage is obtained is set based on the output shaft rotation speed. A rotation speed setting section;
An abnormality determination unit that determines whether or not the input shaft rotation number calculated by the input shaft rotation number calculation unit is less than the input shaft abnormal rotation number;
When the abnormality determining unit determines that the input shaft rotational speed is less than the input shaft abnormal rotational speed, all of the plurality of hydraulic friction engagement devices that establish the gear stage at that time are disengaged. An abnormal time control unit,
A control device for an automatic transmission for a vehicle, comprising:

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