JP4816330B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control apparatus, and more particularly to a technique for controlling a vehicle including an automatic transmission that engages a friction engagement element to form a gear stage.

  Conventionally, a vehicle equipped with an automatic transmission that engages a friction engagement element to form a gear stage is known. In such an automatic transmission, the friction engagement element may not be engaged at the timing as controlled. In this case, the gear stage can be formed by engaging the friction engagement element after the neutral state is temporarily reached during the shift. Therefore, the friction engagement element can be engaged after the output shaft rotational speed of the drive source, that is, the input shaft rotational speed of the automatic transmission, becomes excessive during the neutral state. Therefore, the shock generated when the friction engagement elements are engaged increases. Thus, a technique for suppressing the occurrence of a large shock has been proposed.

  Japanese Patent Laying-Open No. 2003-232438 (Patent Document 1) is supplied to a speed change mechanism to which rotation from an engine is input, a starting friction engagement element that is engaged when starting a vehicle, and a solenoid valve. Disclosed is a control device for an automatic transmission that includes a hydraulic servo device that engages and disengages a friction engagement element by supplying and discharging an output hydraulic pressure corresponding to an electrical signal and an engine load detection device that detects a load state of the engine. . When determining that the output hydraulic pressure according to the command for engaging the friction engagement element is not supplied, the control device determines whether or not the engine is in a predetermined high load state, and the predetermined high load state is determined. In this case, a control device is included that sends a command to release the frictional engagement element, and sends a command to engage the frictional engagement element when the high load state changes to a predetermined low load state.

According to the control device described in this publication, when a command to engage the starting frictional engagement element is sent, the solenoid valve is activated and the hydraulic servo device sends the output hydraulic pressure to the hydraulic drive unit of the frictional engagement element. The friction engagement element is engaged by supplying and discharging. At this time, if the valve body of the solenoid valve sticks, for example, and the hydraulic servo device does not output the output hydraulic pressure and the friction engagement element for starting does not engage, the engine speed increases and the friction engagement element The input side speed increases. In this state, when the stick of the valve body of the solenoid valve is released and the hydraulic servo device supplies the hydraulic pressure to the hydraulic drive unit of the friction engagement element, the friction engagement element is suddenly engaged and a large shock is generated. Therefore, when the output hydraulic pressure corresponding to the command for engaging the starting frictional engagement element is not supplied, and the engine is in a predetermined high load state, a command for releasing the frictional engagement element is sent out. For this reason, it is possible to prevent a large shock from being generated due to sudden engagement of the starting frictional engagement element when the engine is in a high load state.
Japanese Patent Laid-Open No. 2003-232438

  By the way, in an automatic transmission, when the friction engagement element cannot be engaged as controlled, that is, when a gear stage cannot be formed, hydraulic pressure that is not regulated by, for example, a solenoid valve is supplied to the friction engagement element. In some cases, fail-safe for forcibly engaging the friction engagement element is performed. Even when the friction engagement element is engaged by performing fail-safe, a shock may occur during the engagement. Therefore, it is conceivable to apply the control device described in Japanese Patent Application Laid-Open No. 2003-232438 to fail-safe so that fail-safe is not performed at high load but fail-safe is performed at low load. However, in fail-safe, the hydraulic pressure may be supplied to the friction engagement element without being regulated, so that a large shock may occur even if fail-safe is performed at low load.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle control device that can suppress occurrence of a large shock.

  A vehicle control device according to a first aspect of the present invention is a vehicle control device including a power source and an automatic transmission that is connected to the power source and forms a gear stage by engaging a friction engagement element. . The control device includes means for determining a failure in which the frictional engagement element is not engaged in the automatic transmission, means for determining whether or not the first condition regarding the load of the power source is satisfied, If it is determined that the above condition is satisfied, a means for permitting fail-safe for engaging the frictional engagement element when a failure is determined and fail-safe when fail-safe is permitted A means for controlling the automatic transmission, a means for determining whether or not the second condition relating to the torque input to the automatic transmission is satisfied, and an elapsed time after the fail safe is permitted is predetermined. Means for controlling the automatic transmission to stop fail-safe when it is determined that the second condition is satisfied in a state shorter than the given time.

  According to the first aspect of the present invention, it is determined that the frictional engagement element is not engaged in the automatic transmission. It is determined whether or not the first condition regarding the load of the power source is satisfied. For example, the operating amount of the adjusting mechanism that adjusts the amount of air taken into the internal combustion engine as a power source is smaller than a predetermined operating amount, and the rotational speed of the internal combustion engine is lower than the predetermined rotational speed. It is determined whether or not a condition, that is, a condition that the load of the power source is low can be satisfied. When it is determined that the first condition is satisfied, fail-safe for engaging the friction engagement element when the failure is determined is permitted. Fail-safe is performed when fail-safe is permitted. As a result, the gear stage can be formed by performing fail-safe in a state where the load of the power source is low. Further, it is determined whether or not the second condition regarding the torque input to the automatic transmission is satisfied. For example, the condition that the accelerator opening is larger than a predetermined opening and the input shaft rotation speed of the automatic transmission is higher than the synchronous rotation speed when the gear stage is formed, that is, input to the automatic transmission. It is determined whether or not a condition that can be said to be large is applied. It is determined that the second condition is satisfied in a state in which an elapsed time after the fail safe is permitted is shorter than a predetermined time, for example, a time from when the fail safe is permitted until the friction engagement element is engaged. If this happens, failsafe is canceled. Thereby, it can suppress that fail safe is performed in the state where the torque input into an automatic transmission is large. Therefore, it can suppress that a big shock generate | occur | produces when a friction engagement element engages. As a result, it is possible to provide a vehicle control device that can suppress the occurrence of a large shock.

  In the vehicle control device according to the second invention, in addition to the configuration of the first invention, the predetermined time is a time from when the fail safe is permitted until the friction engagement element is engaged.

  According to the second invention, when it is determined that the second condition is satisfied in a state shorter than the time from when the fail safe is permitted until the friction engagement element is engaged, the fail safe is stopped. Thereby, it can suppress that a big shock generate | occur | produces when a friction engagement element engages in the state where the torque input into a dynamic transmission is large.

  In the vehicle control apparatus according to the third invention, in addition to the configuration of the first or second invention, the power source is an internal combustion engine. The first condition is that the operating amount of the adjusting mechanism that adjusts the amount of air taken into the internal combustion engine is smaller than the predetermined operating amount, and the rotational speed of the internal combustion engine is lower than the predetermined rotational speed. It is a condition. The second condition is that the accelerator opening is larger than a predetermined opening, and the input shaft rotational speed of the automatic transmission is higher than the synchronous rotational speed when the gear stage is formed.

  According to the third invention, the operation amount of the adjustment mechanism for adjusting the amount of air taken into the internal combustion engine as the power source is smaller than the predetermined operation amount, and the rotation speed of the internal combustion engine is predetermined. If it is determined that the condition that the load of the power source is low, that is, the condition that the load of the power source is low, the fail safe is permitted. The condition that the accelerator opening is larger than a predetermined opening and the input shaft rotational speed of the automatic transmission is higher than the synchronous rotational speed when the gear stage is formed, that is, input to the automatic transmission. If it is determined that the condition that the torque can be said to be large is satisfied, the fail safe is stopped. Thereby, fail safe can be performed only when the load of the power source is low and the torque input to the automatic transmission is small. Therefore, it can suppress that a big shock generate | occur | produces when a friction engagement element engages.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A vehicle equipped with a control device according to an embodiment of the present invention will be described with reference to FIG. This vehicle is an FR (Front engine Rear drive) vehicle. A vehicle other than FR may be used.

  The vehicle includes an engine 1000, an automatic transmission 2000, a torque converter 2100, a planetary gear unit 3000 that forms part of the automatic transmission 2000, a hydraulic circuit 4000 that forms part of the automatic transmission 2000, a propeller shaft 5000, A differential gear 6000, a rear wheel 7000, and an ECU (Electronic Control Unit) 8000 are included. The control device according to the present embodiment is realized by executing a program recorded in a ROM (Read Only Memory) 8002 of ECU 8000, for example.

  Engine 1000 is an internal combustion engine that burns a mixture of fuel and air injected from an injector (not shown) in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated. The auxiliary power 1004 such as an alternator and an air conditioner is driven by the driving force of the engine 1000. A motor may be used as a power source instead of or in addition to engine 1000.

  Automatic transmission 2000 is connected to engine 1000 via torque converter 2100. Automatic transmission 2000 changes the rotational speed of the crankshaft to a desired rotational speed by forming a desired gear stage.

  The driving force output from automatic transmission 2000 is transmitted to left and right rear wheels 7000 via propeller shaft 5000 and differential gear 6000.

  The ECU 8000 includes a position switch 8006 for the shift lever 8004, an accelerator opening sensor 8010 for the accelerator pedal 8008, a pedaling force sensor 8014 for the brake pedal 8012, a throttle opening sensor 8018 for the electronic throttle valve 8016, and an engine speed sensor 8020. The input shaft rotational speed sensor 8022, the output shaft rotational speed sensor 8024, the oil temperature sensor 8026, and the water temperature sensor 8028 are connected via a harness or the like.

  The position (position) of shift lever 8004 is detected by position switch 8006, and a signal representing the detection result is transmitted to ECU 8000. Corresponding to the position of the shift lever 8004, the gear stage of the automatic transmission 2000 is automatically formed. Further, a manual shift mode in which the driver can select an arbitrary gear stage may be selected according to the driver's operation.

  Accelerator opening sensor 8010 detects the opening of accelerator pedal 8008 and transmits a signal representing the detection result to ECU 8000. The pedaling force sensor 8014 detects the pedaling force of the brake pedal 8012 (the force with which the driver steps on the brake pedal 8012), and transmits a signal representing the detection result to the ECU 8000.

  The throttle opening sensor 8018 detects the opening of the electronic throttle valve 8016 whose opening is adjusted by the actuator, and transmits a signal representing the detection result to the ECU 8000. Electronic throttle valve 8016 adjusts the amount of air taken into engine 1000 (output of engine 1000).

  Instead of or in addition to the electronic throttle valve 8016, the amount of air drawn into the engine 1000 can be reduced by changing the lift amount of the intake valve (not shown) or the exhaust valve (not shown) and the opening / closing phase. You may make it adjust.

  Engine rotation speed sensor 8020 detects the rotation speed of the output shaft (crankshaft) of engine 1000 and transmits a signal representing the detection result to ECU 8000. Input shaft rotational speed sensor 8022 detects input shaft rotational speed NI of automatic transmission 2000 (turbine rotational speed NT of torque converter 2100), and transmits a signal representing the detection result to ECU 8000. Output shaft rotational speed sensor 8024 detects output shaft rotational speed NO of automatic transmission 2000 and transmits a signal representing the detection result to ECU 8000.

  Oil temperature sensor 8026 detects the temperature (oil temperature) of oil (ATF: Automatic Transmission Fluid) used for the operation and lubrication of automatic transmission 2000, and transmits a signal indicating the detection result to ECU 8000.

  Water temperature sensor 8028 detects the temperature (water temperature) of cooling water for engine 1000 and transmits a signal representing the detection result to ECU 8000.

  The ECU 8000 includes a position switch 8006, an accelerator opening sensor 8010, a pedal effort sensor 8014, a throttle opening sensor 8018, an engine speed sensor 8020, an input shaft speed sensor 8022, an output shaft speed sensor 8024, an oil temperature sensor 8026, and a water temperature sensor. Based on a signal sent from 8028 or the like, a map stored in the ROM 8002, and a program, the devices are controlled so that the vehicle is in a desired running state.

  In the present embodiment, ECU 8000 has the forward 1st to 8th gears when the shift lever 8004 is in the D (drive) position and the D (drive) range is selected as the shift range of automatic transmission 2000. Automatic transmission 2000 is controlled so that one of these gears is formed. The automatic transmission 2000 can transmit a driving force to the rear wheel 7000 by forming any one of the first to eighth forward gears. In the D range, it may be possible to form a higher gear than the eighth gear. The gear stage to be formed is determined based on a shift diagram created in advance by experiments or the like using the vehicle speed and the accelerator opening as parameters.

  In addition, ECU 8000, when shift lever 8004 is in the R (reverse) position and R (reverse) range is selected as the shift range of automatic transmission 2000, either reverse 1st gear or 2nd gear is selected. The automatic transmission 2000 is controlled so that the following gears are formed. The number of reverse gears is not limited to two.

  As shown in FIG. 1, ECU 8000 includes an engine ECU 8100 that controls engine 1000 and an ECT (Electronic Controlled Transmission) _ECU 8200 that controls automatic transmission 2000.

  Engine ECU 8100 and ECT_ECU 8200 are configured to be able to transmit and receive signals to and from each other. In the present embodiment, engine ECU 8100 transmits a signal representing the accelerator opening to ECT_ECU 8200. ECT_ECU 8200 transmits to engine ECU 8100 a signal representing a torque request amount determined as torque to be output by engine 1000.

  The planetary gear unit 3000 will be described with reference to FIG. Planetary gear unit 3000 is connected to a torque converter 2100 having an input shaft 2102 coupled to the crankshaft.

  The planetary gear unit 3000 includes a front planetary 3100, a rear planetary 3200, a C1 clutch 3301, a C2 clutch 3302, a C3 clutch 3303, a C4 clutch 3304, a B1 brake 3311, a B2 brake 3312, and a one-way clutch (F). 3320.

  The front planetary 3100 is a double pinion type planetary gear mechanism. Front planetary 3100 includes a first sun gear (S1) 3102, a pair of first pinion gears (P1) 3104, a carrier (CA) 3106, and a ring gear (R) 3108.

  The first pinion gear (P1) 3104 meshes with the first sun gear (S1) 3102 and the first ring gear (R) 3108. The first carrier (CA) 3106 supports the first pinion gear (P1) 3104 so that it can revolve and rotate.

  First sun gear (S1) 3102 is fixed to gear case 3400 so as not to rotate. First carrier (CA) 3106 is coupled to input shaft 3002 of planetary gear unit 3000.

  The rear planetary 3200 is a Ravigneaux type planetary gear mechanism. The rear planetary 3200 includes a second sun gear (S2) 3202, a second pinion gear (P2) 3204, a rear carrier (RCA) 3206, a rear ring gear (RR) 3208, a third sun gear (S3) 3210, a third Pinion gear (P3) 3212.

  Second pinion gear (P2) 3204 meshes with second sun gear (S2) 3202, rear ring gear (RR) 3208, and third pinion gear (P3) 3212. Third pinion gear (P3) 3212 meshes with third sun gear (S3) 3210 in addition to second pinion gear (P2) 3204.

  The rear carrier (RCA) 3206 supports the second pinion gear (P2) 3204 and the third pinion gear (P3) 3212 so that they can revolve and rotate. Rear carrier (RCA) 3206 is coupled to one-way clutch (F) 3320. The rear carrier (RCA) 3206 becomes non-rotatable when driving the first gear (when traveling using the driving force output from the engine 1000). Rear ring gear (RR) 3208 is coupled to output shaft 3004 of planetary gear unit 3000.

  The one-way clutch (F) 3320 is provided in parallel with the B2 brake 3312. That is, the outer race of the one-way clutch (F) 3320 is fixed to the gear case 3400, and the inner race is connected to the rear carrier (RCA) 3206.

  FIG. 3 shows an operation table showing the relationship between each gear position and the operation state of each clutch and each brake. By operating the brakes and the clutches in the combinations shown in the operation table, a forward 1st to 8th gear and a reverse 1st and 2nd gear are formed.

  The main part of the hydraulic circuit 4000 will be described with reference to FIG. The hydraulic circuit 4000 is not limited to the one described below.

  The hydraulic circuit 4000 includes an oil pump 4004, a primary regulator valve 4006, a manual valve 4100, a solenoid modulator valve 4200, an SL1 linear solenoid (hereinafter referred to as SL (1)) 4210, and an SL2 linear solenoid (hereinafter referred to as “the solenoid valve”). SL2 (described as SL (4)) 4220, SL3 linear solenoid (hereinafter referred to as SL (3)) 4230, SL4 linear solenoid (hereinafter referred to as SL (4)) 4240, and SL5 linear solenoid (hereinafter referred to as SL (3)). , SL (5)) 4250 and SLT linear solenoid (hereinafter referred to as SLT) 4300.

  The hydraulic circuit 4000 further includes a B2 control valve 4500, an SLU linear solenoid 4502, a C4 control valve 4510, and an SL solenoid 4512.

  Oil pump 4004 is connected to the crankshaft of engine 1000. As the crankshaft rotates, the oil pump 4004 is driven to generate hydraulic pressure. The hydraulic pressure generated by the oil pump 4004 is regulated by the primary regulator valve 4006 to generate a line pressure.

  Primary regulator valve 4006 operates using the throttle pressure regulated by SLT 4300 as a pilot pressure. The line pressure is supplied to the manual valve 4100 via the line pressure oil passage 4010.

  Manual valve 4100 includes a drain port 4105. From the drain port 4105, the oil pressure in the D range pressure oil passage 4102 and the R range pressure oil passage 4104 is discharged. When the spool of the manual valve 4100 is in the D position, the line pressure oil passage 4010 and the D range pressure oil passage 4102 are communicated, and hydraulic pressure is supplied to the D range pressure oil passage 4102. At this time, the R range pressure oil passage 4104 and the drain port 4105 are communicated, and the R range pressure of the R range pressure oil passage 4104 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the R position, the line pressure oil passage 4010 and the R range pressure oil passage 4104 are communicated, and the oil pressure is supplied to the R range pressure oil passage 4104. At this time, the D range pressure oil passage 4102 and the drain port 4105 are communicated, and the D range pressure in the D range pressure oil passage 4102 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the N position, both the D range pressure oil passage 4102 and the R range pressure oil passage 4104 are connected to the drain port 4105, and the D range pressure and R of the D range pressure oil passage 4102 are communicated. The R range pressure of the range pressure oil passage 4104 is discharged from the drain port 4105.

  The hydraulic pressure supplied to the D range pressure oil path 4102 is finally supplied to the C1 clutch 3301, the C2 clutch 3302, and the C3 clutch 3303. The hydraulic pressure supplied to the R range pressure oil passage 4104 is finally supplied to the B2 brake 3312.

  The solenoid modulator valve 4200 adjusts the hydraulic pressure (solenoid modulator pressure) supplied to the SLT 4300 to a constant pressure using the line pressure as the original pressure.

  SL (1) 4210 regulates the hydraulic pressure supplied to the C1 clutch 3301. SL (2) 4220 regulates the hydraulic pressure supplied to C2 clutch 3302. SL (3) 4230 regulates the hydraulic pressure supplied to the C3 clutch 3303. SL (4) 4240 regulates the hydraulic pressure supplied to C4 clutch 3304. SL (5) 4250 regulates the hydraulic pressure supplied to the B1 brake 3311.

  The SLT 4300 adjusts the solenoid modulator pressure in accordance with a control signal from the ECU 8000 based on the accelerator opening detected by the accelerator opening sensor 8010, and generates a throttle pressure. The throttle pressure is supplied to the primary regulator valve 4006 via the SLT oil passage 4302. The throttle pressure is used as a pilot pressure for the primary regulator valve 4006.

  SL (1) 4210, SL (2) 4220, SL (3) 4230, SL (4) 4240, SL (5) 4250, and SLT 4300 are controlled by a control signal transmitted from ECU 8000.

  The B2 control valve 4500 selectively supplies hydraulic pressure from one of the D range pressure oil passage 4102 and the R range pressure oil passage 4104 to the B2 brake 3312. A D range pressure oil passage 4102 and an R range pressure oil passage 4104 are connected to the B2 control valve 4500. The B2 control valve 4500 is controlled by the hydraulic pressure supplied from the SLU linear solenoid 4502 and the biasing force of the spring.

  When the SLU linear solenoid 4502 is on, the B2 control valve 4500 is in the left side state in FIG. In this case, the B2 brake 3312 is supplied with the hydraulic pressure adjusted from the D range pressure using the hydraulic pressure supplied from the SLU linear solenoid 4502 as a pilot pressure.

  When the SLU linear solenoid 4502 is off, the B2 control valve 4500 is in the state on the right side in FIG. In this case, the R range pressure is supplied to the B2 brake 3312.

  C4 control valve 4510 selectively supplies hydraulic pressure from one of SL (4) 4240 and R range pressure oil passage 4104 to C4 clutch 3304. SL (4) 4240 and R range pressure oil passage 4104 are connected to C4 control valve 4510. C4 control valve 4510 is controlled by the hydraulic pressure supplied from SL solenoid 4512 and the biasing force of the spring.

  When the SL solenoid 4512 is on, the C4 control valve 4510 is in the left side state in FIG. In this case, the hydraulic pressure regulated by SL (4) 4240 is supplied to the C4 clutch 3304.

  When the SL solenoid 4512 is off, the C4 control valve 4510 is in the state on the right side in FIG. In this case, the R range pressure is supplied to the C4 clutch 3304.

  In this embodiment, when the reverse gear stage is formed, the SL (4) 4240 or the SLU linear solenoid 4502 is out of order and the C4 clutch 3304 or the B2 brake 3312 cannot be engaged. Then, fail safe is performed by turning off the SL solenoid 4512 and engaging the C4 clutch 3304. The gear stage formed by fail-safe is not limited to the reverse gear stage. Further, the friction engagement element engaged by fail-safe is not limited to the C4 clutch 3304.

  The ECU 8000 will be further described with reference to FIG. The functions of ECU 8000 described below may be realized by hardware or may be realized by software.

  Engine ECU 8100 of ECU 8000 includes a torque control unit 8110. The torque control unit 8110 receives the torque request amount output from the ECT_ECU 8200, and the throttle opening of the electronic throttle valve 8016 and the ignition timing by the ignition plug so that the torque corresponding to the torque request amount is output from the engine 1000. To control.

  The ECT_ECU 8200 of the ECU 8000 includes a torque request unit 8210, a vehicle speed detection unit 8220, a shift control unit 8230, a failure determination unit 8240, a first condition determination unit 8250, a permission unit 8252, a fail safe execution unit 8260, and a measurement. Unit 8270, elapsed time determination unit 8272, second condition determination unit 8280, and failsafe stop unit 8282.

  Torque requesting unit 8210 sets a torque request amount that is a torque required for engine 1000 based on the accelerator opening and the like.

  The vehicle speed detector 8220 calculates (detects) the vehicle speed from the output shaft rotational speed NO of the automatic transmission 2000.

  As shown in FIG. 6, the shift control unit 8230 performs an upshift or a downshift according to a shift diagram using the vehicle speed and the accelerator opening as parameters. In the shift diagram, an upshift line and a downshift line are set for each type of shift (combination of the gear stage before the shift and the gear stage after the shift). When the gear shift is performed, the friction engagement elements are normally engaged with the combinations described in the operation table of FIG. 3 described above.

  Whether or not the failure determination unit 8240 is a neutral failure in which the C4 clutch 3304 or the B2 brake 3312 cannot be engaged because the SL (4) 4240 or the SLU linear solenoid 4502 has failed when forming the reverse gear. Judge whether or not.

  Failure determination unit 8240 has a value obtained by subtracting the product of output shaft rotational speed NO and gear ratio, that is, the synchronous rotational speed, from input shaft rotational speed NI (turbine rotational speed NT) of automatic transmission 2000, and threshold value ΔN (1 ) Greater than), a neutral fault is determined. Note that the method for determining whether or not there is a neutral failure is not limited to this.

  First condition determination unit 8250 is a condition that the throttle opening is smaller than threshold value THA (0) and engine speed NE is lower than threshold value NE (0), that is, engine 1000 is at a low load. It is determined whether or not a condition that can be said is satisfied.

  Allowing unit 8252 satisfies the condition that the throttle opening is smaller than threshold value THA (0) and engine speed NE is lower than threshold value NE (0) in a state where it is determined that a neutral failure has occurred. When it is determined, fail-safe to engage the C4 clutch 3304 by turning off the SL solenoid 4512 is permitted.

  Fail-safe execution unit 8260 performs fail-safe when fail-safe is permitted. That is, control is performed so that the SL solenoid 4512 is turned off.

  The measuring unit 8270 has a condition that the elapsed time after failsafe is permitted, that is, the throttle opening is smaller than the threshold value THA (0) and the engine speed NE is lower than the threshold value NE (0). Measure the elapsed time since being satisfied.

  The elapsed time determination unit 8272 determines whether or not the elapsed time after failsafe is permitted is shorter than the threshold value T (0). The threshold value T (0) is the time from when the fail safe is permitted until the C4 clutch 3304 is engaged. The threshold value T (0) is determined in advance by measuring the time until the C4 clutch 3304 is engaged after fail-safe is permitted by experiment or simulation. Note that the method for determining the threshold value T (0) is not limited to this.

  Second condition determining unit 8280 has a condition that the accelerator opening is larger than threshold value PA (0) and the value obtained by subtracting synchronous rotational speed from turbine rotational speed NT is larger than threshold value ΔN (2). Then, it is determined whether or not a condition that the input torque of automatic transmission 2000 is large is satisfied.

  Fail-safe stop unit 8282 has an accelerator opening larger than threshold PA (0) and a turbine rotational speed NT in a state where the elapsed time after fail-safe is permitted is shorter than threshold T (0). When it is determined that the condition that the value obtained by subtracting the synchronous rotation speed is larger than the threshold value ΔN (2) is satisfied, the fail safe is stopped. That is, control is performed so that the SL solenoid 4512 is turned on.

  A control structure of a program executed when ECU 8000 serving as the control device according to the present embodiment forms the reverse gear will be described with reference to FIGS. 7 and 8. Note that the program described below is repeatedly executed at a predetermined cycle.

  In step (hereinafter, step is abbreviated as S) 100, ECU 8000 detects turbine rotation speed NT (input shaft rotation speed NI) based on the signal transmitted from input shaft rotation speed sensor 8022, and rotates the output shaft. Based on the signal transmitted from the number sensor 8024, the output shaft rotational speed NO is detected.

  In S102, ECU 8000 determines whether or not there is a neutral failure. If it is a neutral failure (YES in S102), the process proceeds to S110. Otherwise (NO in S102), this process ends.

  In S110, ECU 8000 detects the throttle opening based on the signal transmitted from throttle opening sensor 8018, and detects the engine speed NE based on the signal transmitted from engine speed sensor 8020.

  In S112, ECU 8000 determines whether or not a condition that the throttle opening is smaller than threshold value THA (0) and the engine speed NE is lower than threshold value NE (0) is satisfied.

  If the condition that the throttle opening is smaller than threshold value THA (0) and engine speed NE is lower than threshold value NE (0) (YES in S112), the process proceeds to S120. Otherwise (NO in S112), this process ends.

  At S120, ECU 8000 permits fail-safe for turning off SL solenoid 4512 and engaging C4 clutch 3304. In S122, ECU 8000 starts measuring the elapsed time after fail-safe is permitted. In S124, ECU 8000 starts fail-safe.

  In S130, ECU 8000 determines whether or not the elapsed time after fail safe is permitted is shorter than threshold value T (0). If the elapsed time is shorter than threshold value T (0) (YES in S130), the process proceeds to S132. Otherwise (NO at S130), this process ends.

  At S132, ECU 8000 determines the accelerator opening based on the signal transmitted from accelerator opening sensor 8010, turbine rotational speed NT based on the signal transmitted from input shaft rotational speed sensor 8022, and output shaft rotational speed sensor. Based on the signal transmitted from 8024, the output shaft rotational speed NO is detected.

  In S134, ECU 8000 satisfies the condition that the accelerator opening is larger than threshold value PA (0) and that the value obtained by subtracting synchronous rotational speed from turbine rotational speed NT is larger than threshold value ΔN (2). Judge whether or not.

  If the condition that the accelerator opening is larger than threshold PA (0) and the value obtained by subtracting synchronous rotational speed from turbine rotational speed NT is larger than threshold ΔN (2) (YES in S134), The process proceeds to S140. If not (NO in S134), the process returns to S130. In S140, ECU 8000 stops fail-safe.

  The operation of ECU 8000 serving as the control device according to the present embodiment based on the structure and flowchart as described above will be described.

  When the reverse gear is formed, the turbine rotational speed NT is detected based on the signal transmitted from the input shaft rotational speed sensor 8022, and the output shaft rotational speed is based on the signal transmitted from the output shaft rotational speed sensor 8024. NO is detected (S100).

  If the product of the output shaft rotational speed NO and the gear ratio, that is, the value obtained by subtracting the synchronous rotational speed is larger than the threshold value ΔN (1) from the turbine rotational speed NT, the reverse gear stage is not formed, and the automatic transmission 2000 can be said to be in a neutral state. In this case, it is determined that there is a neutral failure (YES in S102).

  If it is a neutral failure (YES in S102), the throttle opening is detected based on the signal transmitted from the throttle opening sensor 8018, and the engine speed NE is determined based on the signal transmitted from the engine speed sensor 8020. Is detected (S110).

  When the throttle opening is smaller than the threshold value THA (0) and the engine speed NE is lower than the threshold value NE (0), it can be said that the load on the engine 1000 is low. Therefore, even if fail safe is executed and the C4 clutch 3304 is engaged, it can be said that the generated shock is small.

  Therefore, if the condition that the throttle opening is smaller than threshold value THA (0) and engine speed NE is lower than threshold value NE (0) (YES in S112), SL solenoid 4512 is turned off. Fail-safe for engaging the C4 clutch 3304 is permitted (S120). Then, measurement of the elapsed time after fail safe is permitted is started (S124). Also, fail safe is started (S124).

  By the way, even if the load of the engine 1000 at the time when the fail safe is started is low, the input of the automatic transmission 2000 when the C4 clutch 3304 is actually engaged by the accelerator operation after the start of the fail safe is performed. Torque may increase. In this case, since the shock increases, it is preferable to stop the fail safe.

  Therefore, if the elapsed time after failsafe is permitted is shorter than threshold value T (0) (YES in S130), that is, if C4 clutch 3304 is not engaged, the magnitude of input torque is determined. Therefore, the accelerator opening, the turbine speed NT, and the output shaft speed NO are detected (S132).

  If the accelerator opening is larger than the threshold PA (0) and the value obtained by subtracting the synchronous rotational speed from the turbine rotational speed NT is larger than the threshold ΔN (2), it can be said that the input torque of the automatic transmission 2000 is large. .

  Therefore, if the condition that the accelerator opening is larger than threshold PA (0) and the value obtained by subtracting synchronous rotational speed from turbine rotational speed NT is larger than threshold ΔN (2) (YES in S134) ), Fail-safe is canceled (S140). Thereby, it can suppress that a big shock generate | occur | produces.

  As described above, according to ECU 8000 serving as the control device according to the present embodiment, when the neutral failure occurs, the throttle opening is smaller than threshold value THA (0), and engine speed NE is equal to threshold value NE (0 ) If the condition of lower is satisfied, fail-safe to engage the C4 clutch by turning off the SL solenoid is permitted. When fail-safe is permitted, fail-safe is started. A value obtained by subtracting the synchronous engine speed from the turbine speed NT and the accelerator opening is greater than the threshold value PA (0) in a state where the elapsed time since the fail safe is permitted is shorter than the threshold value T (0). However, if the condition that the value is larger than the threshold value ΔN (2) is satisfied, the fail safe is stopped. Thereby, it can suppress that C4 clutch is engaged in the state in which the input torque to an automatic transmission is large. Therefore, it can suppress that a big shock generate | occur | produces.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic block diagram which shows the power train of a vehicle. It is a skeleton figure which shows the planetary gear unit of an automatic transmission. It is a figure which shows the operation | movement table | surface of an automatic transmission. It is a figure which shows the hydraulic circuit of an automatic transmission. It is a functional block diagram of ECU. It is a figure which shows a shift map. It is FIG. (1) which shows the control structure of the program which ECU performs. It is FIG. (2) which shows the control structure of the program which ECU performs.

Explanation of symbols

  1000 Engine, 2000 Automatic transmission, 2100 Torque converter, 3000 Planetary gear unit, 3301 C1 clutch, 3302 C2 clutch, 3303 C3 clutch, 3304 C4 clutch, 3311 B1 brake, 3312 B2 brake, 4000 Hydraulic circuit, 4510 C4 control valve, 4512 SL Solenoid, 8000 ECU, 8002 ROM, 8004 shift lever, 8006 position switch, 8008 accelerator pedal, 8010 accelerator opening sensor, 8012 brake pedal, 8014 pedal force sensor, 8016 electronic throttle valve, 8018 throttle opening sensor, 8020 engine speed sensor , 8022 Input shaft speed sensor, 8024 output Shaft speed sensor, 8026 Oil temperature sensor, 8028 Water temperature sensor, 8100 Engine ECU, 8110 Torque control unit, 8200 ECT_ECU, 8210 Torque request unit, 8220 Vehicle speed detection unit, 8230 Shift control unit, 8240 Failure judgment unit, 8250 Condition judgment unit , 8252 permission unit, 8260 fail safe execution unit, 8270 measurement unit, 8272 elapsed time determination unit, 8280 condition determination unit, 8282 fail safe stop unit.

Claims (3)

A vehicle control device comprising: a power source; and an automatic transmission that is connected to the power source and forms a gear stage by engaging a friction engagement element.
Means for determining a failure in which the friction engagement element is not engaged in the automatic transmission;
Means for determining whether or not a first condition relating to a load of the power source is satisfied;
Means for allowing failsafe to engage the frictional engagement element when the failure is determined when it is determined that the first condition is satisfied;
Means for controlling the automatic transmission to perform the fail safe when the fail safe is permitted;
Means for determining whether or not a second condition relating to torque input to the automatic transmission is satisfied;
When it is determined that the second condition is satisfied in a state in which an elapsed time since the fail safe is permitted is shorter than a predetermined time, the automatic transmission is controlled to stop the fail safe. And a vehicle control device.   The vehicle control device according to claim 1, wherein the predetermined time is a time from when the fail safe is permitted until the friction engagement element is engaged. The power source is an internal combustion engine,
The first condition is that an operation amount of an adjustment mechanism that adjusts an amount of air taken into the internal combustion engine is smaller than a predetermined operation amount, and the rotation speed of the internal combustion engine is higher than a predetermined rotation speed. Is also low,
The second condition is that the accelerator opening is larger than a predetermined opening, and the input shaft rotational speed of the automatic transmission is higher than the synchronous rotational speed when the gear stage is formed. The vehicle control device according to claim 1 or 2, wherein

Images