JP5050774B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a control device for a vehicle in which an engine (internal combustion engine) and an automatic transmission are mounted, and more specifically, for a vehicle in which an automatic transmission having a fluid transmission device (torque converter) with a lock-up clutch is mounted. The present invention relates to a control device.

  In a vehicle equipped with an engine, the gear ratio between the engine and the drive wheel is automatically set optimally as a transmission that properly transmits the torque and rotation speed generated by the engine to the drive wheel according to the running state of the vehicle. Automatic transmissions are known.

  As an automatic transmission mounted on a vehicle, for example, a planetary gear type transmission that sets a gear stage using a clutch and brake and a planetary gear device, or a belt type continuously variable transmission that adjusts a gear ratio steplessly. (CVT: Continuously Variable Transmission).

  In a vehicle equipped with a planetary gear type automatic transmission, a shift map having a shift line (gear stage switching line) for obtaining an optimum gear stage according to the vehicle speed and the throttle opening degree (or the accelerator opening degree). Is stored in an ECU (Electronic Control Unit) or the like, a target gear stage is calculated with reference to a shift map based on the vehicle speed and the throttle opening, and a clutch that is a friction engagement element is calculated based on the target gear stage. The gear stage (shift stage) is automatically set by engaging or releasing the brake and the one-way clutch in a predetermined state.

  Belt type continuously variable transmissions have a belt wound around a primary pulley (input pulley) and a secondary pulley (output pulley) that have pulley grooves (V grooves), and the width of the pulley groove of one pulley is increased. At the same time, by narrowing the width of the pulley groove of the other pulley, the belt winding radius (effective diameter) for each pulley is continuously changed to set the transmission ratio steplessly. ing.

  A vehicle equipped with such an automatic transmission is provided with a shift lever operated by a driver, and by operating the shift lever, the shift position of the automatic transmission is set to, for example, a P position (parking). Range), R position (reverse travel range), N position (neutral range), D position (forward travel range), and the like. In recent years, an automatic transmission with a manual transmission function (so-called automatic transmission with a sequential mode) has been put into practical use, and it is possible to arbitrarily switch the shift stage of the automatic transmission by operating the shift lever. ing.

  Further, in a vehicle equipped with an automatic transmission, a torque converter is disposed in a power transmission path from the engine to the automatic transmission. A torque converter includes, for example, a pump connected to an engine output shaft (crankshaft), a turbine connected to an input shaft of an automatic transmission, and a stator provided between the pump and the turbine via a one-way clutch. The pump rotates with the rotation of the engine output shaft, and the turbine rotates by the hydraulic oil discharged from the pump to transmit the engine output torque to the input shaft of the automatic transmission. Device. Further, torque converters having a lock-up clutch are widely used, and the fuel is obtained by engaging (lock-up ON) or releasing (lock-up OFF) the lock-up clutch according to the driving state. Improvement of consumption rate (hereinafter referred to as fuel efficiency) is being attempted.

  By the way, in an automatic transmission having a torque converter with a lock-up clutch, if the control at the time of vehicle deceleration from the lock-up ON state is a control based on steady characteristics according to the normal vehicle speed or the like, the lock-up can be released. There is a possibility that engine stall (hereinafter referred to as engine stall) may occur. In consideration of this point, a control for forcibly releasing the lock-up state when the vehicle deceleration becomes a certain value (fixed value) or more is performed (for example, see Patent Document 1).

  However, in such lock-up release control, the deceleration determination threshold used for lock-up release determination is a fixed value, so that lock-up may be released earlier depending on the state of the vehicle. The corresponding release does not function effectively, and the lockup release may be delayed and an engine stall may occur. As a technique for solving such a problem, there is a technique described in Patent Document 2 below.

In the technique described in Patent Document 2, the deceleration determination threshold is set in consideration of the danger of engine stall based on the slip ratio of the lockup clutch or the gear ratio of the automatic transmission. Specifically, in areas where there is a high risk of engine stall (low gear (speed ratio for low speed), where the slip ratio of the lockup clutch is small), the deceleration determination threshold is reduced and lockup release is determined early. It is supposed to be.
JP 59-117950 A JP-A-11-223263

  By the way, in sports driving such as circuit driving, the vehicle deceleration during braking is large and the frequency of sudden deceleration is high. For this reason, if the lock-up release determination is performed based on the same standard (deceleration determination threshold) as during normal travel (other than sport travel), the lock-up is frequently released. Further, in sport running, the rate of change of deceleration is large, and it may be erroneously determined as sudden deceleration even when it is not sudden deceleration. In this case, the lockup is released. Thus, when the lock-up is frequently released during sports running and the converter state is established, the direct feeling (driving force controllability by the accelerator) like a manual transmission is lost, and the merchantability as a sports car is reduced.

  During sports running, the majority of the driving is low gear (speed ratio for low speed), and there is a case where control for reducing the slip ratio is employed to improve the direct feeling. When such control is employed, a threshold value for setting the deceleration determination threshold value to be small when the slip ratio of the low gear (low speed gear ratio) or the lockup clutch is small as in the technique described in Patent Document 2 described above. If the setting is made, the lock-up is frequently released during sports running.

  The present invention has been made in view of such circumstances, and in a vehicle equipped with an automatic transmission having a fluid transmission device (torque converter) with a lock-up clutch, a direct feeling (driving force by an accelerator) during sports running The purpose is to realize control capable of achieving both controllability) and engine stall resistance during normal driving.

In order to achieve the above object, the present invention is premised on a vehicle control device equipped with an engine, an automatic transmission, and a fluid transmission device disposed between the engine and the automatic transmission. In such a vehicle control apparatus, the manual transmission means that allows the driver to arbitrarily select a shift stage or a shift range of the automatic transmission, and the fluid transmission apparatus when a lock-up condition is satisfied. A lockup control means for executing a lockup that directly connects the input side and the output side of the vehicle, a deceleration detection means for detecting the deceleration of the vehicle, and a deceleration detected by the deceleration detection means is a threshold value. Lock-up releasing means for releasing the lock-up in the above case, sports running determination means for judging that the vehicle is in sports driving when manual shifting is being performed by the manual shifting means, and accelerator ON / OFF an accelerator detection means for detecting a disposed, when the sport travel determining means determines that the sport running, not sports cars Compared to case is set larger the deceleration determination threshold value, when the detection result of the accelerator detecting means is accelerator ON is characterized by the larger the deceleration determination threshold value as compared with the case of the accelerator OFF.

  According to the present invention, it is possible to perform a lockup release determination with different deceleration determination thresholds during sports driving and during normal driving (other than sports driving), and reduce the frequency of lockup cancellation during sports driving. It is possible to secure a direct feeling during sports running.

Specifically, when the sport travel determination means determines that the sport travel is performed, the deceleration determination threshold is set larger than when the sport travel is not performed so that it is difficult to determine whether to release the lockup. Even if braking is performed, it is possible to prevent the lock-up from being released and the converter state being entered. As a result, lock-up control (engagement of the lock-up clutch) can be continued during sport running, and direct feeling (driving force controllability by the accelerator) is improved. Furthermore, in consideration of the fact that the risk of engine stall is less when the accelerator is ON than when the accelerator is OFF, the accelerator ON is set when the deceleration determination threshold is set according to the determination of whether or not the vehicle is a sport run. In such a case, a configuration is adopted in which the deceleration determination threshold value is set larger than in the case where the accelerator is OFF, making it difficult to determine whether to release the lockup.

  In addition, during normal driving (other than sports driving), it is possible to determine lock-up release using a small deceleration determination threshold that takes into account the danger of engine stall, so when sudden braking is performed during normal driving The lockup can be reliably released. As a result, engine stall resistance during normal travel can be ensured.

  As described above, according to the present invention, it is possible to achieve both a direct feeling (driving force controllability by an accelerator) during sports running and an engine stall resistance during normal running.

  Here, in the present invention, the deceleration determination threshold value set during normal driving is, for example, a predetermined margin (engine stall) with respect to deceleration (deceleration during sudden braking) that occurs during normal driving (other than sports driving). The deceleration determination threshold value set during sport running is a value greater than the deceleration determination threshold value during normal running. The deceleration determination threshold value set during sports running is a value that takes into account the danger of engine stall and direct feeling (continuation of lockup control) during sports running.

  In the present invention, when the deceleration determination threshold is set according to whether or not it is a sport running, when the input rotation speed or vehicle speed of the automatic transmission is low, there is a risk of engine stall compared to when it is large. Considering the point of increasing, even when the input speed of the automatic transmission is small, it may be configured to make the determination of lockup release easier by setting the deceleration determination threshold value smaller than when it is large Good.

  Note that the deceleration determination threshold value may be set in consideration of the determination result as to whether or not the vehicle is traveling in the sport and the two conditions of the input speed of the automatic transmission and the accelerator ON / OFF.

  According to the present invention, since the lock-up release determination is performed with different deceleration determination thresholds during sports driving and during normal driving (other than sports driving), direct feeling (driving force controllability by accelerator) during sports driving and Both the engine stall resistance during normal driving can be achieved.

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

  A vehicle power train including the control device of the present invention will be described with reference to FIG.

  The power train of the vehicle in this example includes an engine 1, a torque converter 2, an automatic transmission 3, and an ECU 100, and a vehicle control device is realized by a program executed by the ECU 100.

  Next, each part of engine 1, torque converter 2, automatic transmission 3, and ECU 100 will be described below.

-Engine-
The engine 1 generates driving force by burning an air-fuel mixture in which air sucked from outside and fuel injected from an injector 14 (see FIG. 4) are mixed at an appropriate ratio. A crankshaft 11 that is an output shaft of the engine 1 is connected to an input shaft of the torque converter 2. The rotational speed of the crankshaft 11 (engine rotational speed) is detected by an engine rotational speed sensor 201.

  The amount of air taken into the engine 1 is adjusted by an electronically controlled throttle valve 12. The throttle valve 12 can electronically control the throttle opening independently of the driver's accelerator pedal operation, and the opening (throttle opening) is detected by the throttle opening sensor 202.

  The throttle opening of the throttle valve 12 is driven and controlled by the engine ECU 101. More specifically, the optimum intake air amount (target) according to the operating state of the engine 1 such as the engine speed detected by the engine speed sensor 201 and the accelerator pedal depression amount (accelerator opening) of the driver. The throttle opening of the throttle valve 12 is controlled so that the intake amount) is obtained. More specifically, the actual throttle opening of the throttle valve 12 is detected using the throttle opening sensor 202, and the actual throttle opening becomes the throttle opening (target throttle opening) at which the target intake air amount is obtained. The throttle motor 13 of the throttle valve 12 is feedback controlled so as to match.

-Torque converter, automatic transmission-
As shown in FIG. 1, the torque converter 2 includes a pump impeller 21 on the input shaft side, a turbine impeller 22 on the output shaft side, a stator 23 that exhibits a torque amplification function, and a one-way clutch 24. Power is transmitted between the impeller 21 and the turbine impeller 22 via a fluid.

  The torque converter 2 is provided with a lockup clutch 25 that directly connects the input side and the output side. By completely engaging the lockup clutch 25, the pump impeller 21 and the turbine impeller 22 Rotate together. Further, by engaging the lock-up clutch 25 in a predetermined slip state, the turbine impeller 22 rotates following the pump impeller 21 with a predetermined slip amount during driving. The torque converter 2 and the automatic transmission 3 are connected by a rotating shaft. The turbine speed Nt of the torque converter 2 is detected by the turbine speed sensor 203.

  Engagement / release of the lockup clutch 25 of the torque converter 2 is controlled by a hydraulic control circuit 300 and an ECT_ECU (Electronic Controlled Automatic Transmission_ECU) 102.

  As shown in FIG. 1, the automatic transmission 3 includes a first planetary gear device 31 of a double pinion type, a second planetary gear device 32 of a single pinion type, and a third planetary gear device 33 of a single pinion type. It is a planetary gear type transmission.

  The sun gear S1 of the first planetary gear unit 31 is selectively coupled to the input shaft 30 via the clutch C3. The sun gear S1 is selectively coupled to the housing via the one-way clutch F2 and the brake B3, and is prevented from rotating in the reverse direction (the direction opposite to the rotation of the input shaft 30). The carrier CA1 of the first planetary gear unit 31 is selectively connected to the housing via the brake B1, and is always prevented from rotating in the reverse direction by the one-way clutch F1 provided in parallel with the brake B1. The ring gear R1 of the first planetary gear device 31 is integrally connected to the ring gear R2 of the second planetary gear device 32, and is selectively connected to the housing via the brake B2.

  The sun gear S2 of the second planetary gear device 32 is integrally connected to the sun gear S3 of the third planetary gear device 33, and is selectively connected to the input shaft 30 via the clutch C4. The sun gear S2 is selectively connected to the input shaft 30 via the one-way clutch F0 and the clutch C1, and is prevented from rotating in the opposite direction relative to the input shaft 30.

  The carrier CA2 of the second planetary gear device 32 is integrally connected to the ring gear R3 of the third planetary gear device 33, is selectively connected to the input shaft 30 via the clutch C2, and via the brake B4. And selectively coupled to the housing. The carrier CA2 is always prevented from rotating in the reverse direction by the one-way clutch F3 provided in parallel with the brake B4. The carrier CA3 of the third planetary gear device 33 is integrally connected to the output shaft 34. The rotational speed of the output shaft 34 is detected by the output shaft rotational speed sensor 204.

  The power output from the automatic transmission 3 is transmitted to the pair of drive wheels 6L and 6R via the differential gear unit (final reduction gear) 5 and the pair of axles.

  The operation table of FIG. 2 shows the engagement / release states of the clutches C1 to C4, the brakes B1 to B4, and the one-way clutches F0 to F3 of the automatic transmission 3 described above. In the operation table of FIG. 2, “◯” represents “engaged”, and “blank” represents “released”. Further, “を” represents “engagement during engine braking”, and “Δ” represents “engagement not related to power transmission”.

  As shown in FIG. 2, in the automatic transmission 3 of this example, at the first speed (1st) of the forward gear stage, the clutch C1 is engaged and the one-way clutches F0 and F3 are operated. In the second speed (2nd) of the forward gear stage, the clutch C1 and the third brake B3 are engaged, and the one-way clutches F0, F1, and F2 are operated.

  At the third forward speed (3rd), the clutches C1 and C3 are engaged, the brake B3 is engaged, and the one-way clutches F0 and F1 are operated. At the fourth forward speed (4th), the clutches C1, C2, and C3 are engaged, the brake B3 is engaged, and the one-way clutch F0 is operated.

  At the fifth forward speed (5th), the clutches C1, C2, C3 are engaged, and the brakes B1, B3 are engaged. At the sixth forward speed (6th), the clutches C1 and C2 are engaged, and the brakes B1, B2, and B3 are engaged.

  On the other hand, in the reverse gear stage (R), the clutch C3 is engaged, the brake B4 is engaged, and the one-way clutch F1 is operated.

  As described above, in the automatic transmission 3 of this example, the clutches C1 to C4, the brakes B1 to B4, the one-way clutches F0 to F3, which are friction engagement elements, are engaged or released in a predetermined state. Thus, the gear stage (shift stage) is set. Engagement / release of the clutches C1 to C4 and the brakes B1 to B4 is controlled by the hydraulic control circuit 300 and the ECT_ECU 102.

  On the other hand, a shift device 4 as shown in FIG. 3 is arranged in the vicinity of the driver's seat of the vehicle. The shift device 4 is provided with a shift lever 41 that can be displaced. The shift device 4 is set with a reverse range (R range), a neutral range (N range), a drive range (D range), and a sequential range (S range). The shift lever 41 can be displaced. Each shift range of these R range, N range, D range, and S range (including the following “+” range and “−” range) is detected by a shift position sensor 206 (see FIG. 4).

  Hereinafter, the situation in which these shift ranges are selected and the operation mode of the automatic transmission 3 at that time will be described for each shift range (“N range”, “R range”, “D range”, “S range”). .

  The “N range” is a range selected when the connection between the input shaft 30 and the output shaft 34 of the automatic transmission 3 is disconnected. When the shift lever 41 is operated to the “N range”, the automatic transmission All the three clutches C1 to C4, the brakes B1 to B4, and the one-way clutches F0 to F3 are released (see FIG. 2).

  The “R range” is a range selected when the vehicle is moved backward, and when the shift lever 41 is operated to the R range, the automatic transmission 3 is switched to the reverse gear.

  The “D range” is a range that is selected when the vehicle moves forward. When the shift lever 41 is operated to the D range, a plurality of forward gear stages of the automatic transmission 3 are selected according to the driving state of the vehicle. (Sixth forward speed) is automatically subjected to shift control.

  The “S range” is a range (manual range) that is selected when the driver manually performs a shift operation of a plurality of forward gears (six forward speeds). And a “+” range. The “+” range is a range where the shift lever 41 is operated during a manual upshift, and the “−” range is a range where the shift lever 41 is operated during a manual downshift. When the shift lever 41 is in the S range and the shift lever 41 is operated to the “+” range or the “−” range with the S range as the neutral range, the forward gear of the automatic transmission 3 is increased or decreased. Is done. Specifically, the gear stage is increased by one stage for each operation to the “+” range (for example, 1st → 2nd →... → 6th). On the other hand, the gear stage is lowered by one stage (for example, 6th → 5th →... → 1st) for each operation to the “−” range.

-ECU-
The ECU 100 that controls the above power train includes an engine ECU 101 that controls the engine 1 and an ECT_ECU 102 that controls the torque converter 2 and the automatic transmission 3.

  The engine ECU 101 is an electronic control unit mainly composed of a microcomputer, and includes a CPU, a ROM, a RAM, a backup RAM, and the like. The ROM stores various programs including a program for executing control related to engine operation. The CPU executes arithmetic processing based on various control programs and maps stored in the ROM. The RAM is a memory that temporarily stores calculation results from the CPU, data input from each sensor, and the like. The backup RAM is a non-volatile memory that stores data to be saved when the engine 1 is stopped. is there.

  As shown in FIG. 4, the engine ECU 101 is connected with sensors for detecting the operating state of the engine 1, such as an engine speed sensor 201 and a throttle opening sensor 202, and output signals from the sensors are input. . The engine ECU 101 controls each part of the engine 1 such as the throttle motor 13 of the throttle valve 12 and the injector 14 based on the output signals of the sensors.

  The engine ECU 101 and the ECT_ECU 102 are connected in a state where data communication is possible, and data such as the throttle opening and the engine speed is transmitted from the engine ECU 101 to the ECT_ECU 102. In addition, data related to operation control of the engine 1 is transmitted from the ECT_ECU 102 to the engine ECU 101.

  The ECT_ECU 102 is an electronic control unit mainly composed of a microcomputer, and includes a CPU, a ROM, a RAM, a backup RAM, and the like. In the ROM, in addition to the control related to the basic driving of the vehicle, the shift control for setting the gear stage of the automatic transmission 3 according to the traveling state of the vehicle, and the engagement control of the lock-up clutch 25 of the torque converter 2 ( Various programs including a program for executing (lock-up control) are stored. Specific contents of the shift control and lockup control will be described later. The CPU executes arithmetic processing based on various control programs and maps stored in the ROM. The RAM is a memory that temporarily stores calculation results in the CPU, data input from sensors, and the like, and the backup RAM is a nonvolatile memory.

  As shown in FIG. 4, the ECT_ECU 102 includes a turbine speed sensor 203, an output shaft speed sensor 204, an accelerator position sensor 205 that detects the accelerator pedal position, a shift position sensor 206, a brake pedal sensor 207, and a vehicle speed sensor. 208 and an acceleration sensor 209 for detecting longitudinal acceleration of the vehicle are connected, and signals from these sensors are input.

  Then, the ECT_ECU 102 outputs a solenoid control signal (hydraulic command signal) for setting the gear position of the automatic transmission 3 to the hydraulic control circuit 300. On the basis of this solenoid control signal, excitation / non-excitation of the linear solenoid valve and on / off solenoid valve of the hydraulic control circuit 300 is controlled, and automatic shift is performed so as to constitute a predetermined shift gear stage (1st to 6th gears). The clutches C1 to C4, the brakes B1 to B4, the one-way clutches F0 to F3, etc. of the machine 3 are engaged or released in a predetermined state.

  Further, the ECT_ECU 102 outputs a lockup clutch control signal (hydraulic command signal) to the hydraulic control circuit 300. On the basis of this lockup clutch control signal, excitation / non-excitation of the lockup solenoid valve of the hydraulic control circuit 300 is controlled, and the lockup clutch 25 of the torque converter 2 is engaged or released.

  The above “shift control” and “lock-up control”, and “deceleration lock-up release control” executed by the ECT_ECU 102 will be described below.

-Shift control-
A shift map used for the shift control of this example will be described with reference to FIG.

  The shift map shown in FIG. 5 uses the vehicle speed and the throttle opening as parameters, and a plurality of areas for determining an appropriate gear stage (gear stage that provides optimum fuel efficiency) is set according to the vehicle speed and the throttle opening. This map is stored in the ROM of the ECT_ECU 102. Each region of the shift map is partitioned by a plurality of shift lines (gear stage switching lines).

  In the shift map shown in FIG. 5, the upshift line (shift line) is indicated by a solid line, and the downshift line (shift line) is indicated by a broken line. In addition, each switching direction of upshifting and downshifting is indicated using numerals and arrows in the figure.

  Next, the basic operation of the shift control will be described.

  The ECT_ECU 102 calculates the vehicle speed from the output signal of the vehicle speed sensor 208 (or the output signal of the output shaft speed sensor 204), calculates the throttle opening from the output signal of the throttle opening sensor 202, and determines the vehicle speed and the throttle opening. Based on this, the target gear stage is calculated with reference to the shift map of FIG. 5, and the target gear stage is compared with the current gear stage to determine whether or not a shift operation is necessary.

  According to the determination result, when there is no need for shifting (when the target gear stage and the current gear stage are the same and the gear stage is set appropriately), a solenoid control signal (hydraulic command Signal) to the hydraulic control circuit 300 of the automatic transmission 3.

  On the other hand, when the target gear stage and the current gear stage are different, shift control is performed. For example, when the driving state of the vehicle changes from the state where the gear stage of the automatic transmission 3 is running at the “5-speed” state, for example, the point a changes to the point b shown in FIG. Since the change occurs across the shift line [5 → 4], the target gear stage calculated from the shift map is “fourth speed”, and the solenoid control signal (hydraulic command signal) for setting the fourth gear stage is hydraulically controlled. Output to the circuit 300 to perform a shift (5 → 4 down shift) from the fifth gear to the fourth gear.

  When the S range (manual range) is selected, as described above, the gear stage is increased by one for each operation to the “+” range, and for each operation to the “−” range. The gear stage is lowered by one stage.

-Lock-up control-
An engagement map used for the lock-up control of this example will be described with reference to FIG.

  The engagement map shown in FIG. 6 uses the vehicle speed and the throttle opening as parameters, and areas for determining engagement / release of the lockup clutch 25 according to the vehicle speed and throttle opening (ON area, OFF area). Is set, and is stored in the ROM of the ECT_ECU 102.

  In the engagement map shown in FIG. 6, the engagement switching line from the release (OFF) to the engagement (ON) of the lockup clutch 25 is indicated by a solid line, and the engagement (ON) to the release (OFF) of the lockup clutch 25 is shown. The release switching line is indicated by a broken line. These engagement switching lines (solid lines) and release switching lines (broken lines) are set with a predetermined hysteresis. The reason for providing the hysteresis in this way is to prevent hunting. Further, in the map shown in FIG. 6, the engagement switching line (OFF → ON) and the release switching line (ON → OFF) are set so that the fuel consumption is optimized according to the vehicle speed and the throttle opening.

  Then, the ECT_ECU 102 calculates the engagement map of FIG. 6 based on the actual vehicle speed and throttle opening obtained from the output signals of the vehicle speed sensor 208 (or the output shaft rotational speed sensor 204) and the throttle opening sensor 202. Referring to, the engagement / release of the lockup clutch 25 is switched.

  Specifically, from when the lockup clutch 25 is in the released (OFF) state, the vehicle speed changes to the high vehicle speed side, or the throttle opening changes to the low throttle opening side and the engagement switching line (solid line). Is turned off (OFF → ON), a lockup clutch control signal for engaging the lockup clutch 25 is output to the hydraulic control circuit 300 to switch the lockup clutch 25 to the engaged (ON) state.

  On the other hand, since the lockup clutch 25 is in the engaged (ON) state, the vehicle speed has changed to the low vehicle speed side, or the throttle opening has changed to the high throttle opening side and has crossed the release switching line (broken line). In the case (ON → OFF), a lockup clutch control signal for releasing the lockup clutch 25 is output to the hydraulic control circuit 300 to switch the lockup clutch 25 to the released (OFF) state.

−Deceleration lockup release control−
In the deceleration lock-up release control in this example, it is determined whether or not the vehicle is in sports driving, and when it is determined as sports driving, a large deceleration determination threshold ( It is characterized in that determination of lockup release is performed by setting a vehicle deceleration threshold). The specific control will be described with reference to FIG.

  FIG. 7 is a flowchart showing an example of deceleration lockup release control. The control routine of FIG. 7 is repeatedly executed by the ECT_ECU 102 every predetermined time.

  First, in step ST1, it is determined whether or not lockup control (engagement of the lockup clutch 25) is being executed from the lockup clutch control signal (engagement / release signal) described above. If the determination is negative, the process returns.

  When the determination result of step ST1 is affirmative (that is, when lockup control is being executed), the process proceeds to step ST2. In step ST2, the vehicle deceleration (unit: G) is detected based on the output signal of the acceleration sensor 209.

  Next, in step ST3, it is determined whether or not the sport running. Specifically, when the position of the shift lever 41 detected by the shift position sensor 206 is in the S range (manual range), it is determined (affirmative determination) that it is “during sports running”, and other positions (D If it is (range), it is determined (negative determination) that it is “normal driving (other than sports driving)”. If the determination result in step ST3 is affirmative, the process proceeds to step ST4. If the determination result is negative, the process proceeds to step ST7.

  In step ST4, with reference to the deceleration determination threshold value calculation map shown in FIG. 8, a deceleration determination threshold value (0.5G) during sports running (manual range) is calculated.

  Next, in step ST5, it is determined whether or not the vehicle deceleration detected in step ST2 is greater than the deceleration determination threshold (0.5G) calculated in step ST4.

  If the determination result in step ST4 is affirmative (vehicle deceleration> deceleration determination threshold), a lock-up clutch control signal (release signal) is output to the hydraulic control circuit 300 in order to prevent engine stall during sports running. Thus, the lockup clutch 25 of the torque converter 2 is released (lockup release) (step ST6). If the determination result in step ST5 is negative (vehicle deceleration ≦ deceleration determination threshold), the process returns and lockup control (engagement of the lockup clutch 25) is continued.

  In the deceleration determination threshold value calculation map of FIG. 8, the deceleration determination threshold value during normal driving is predetermined with respect to the deceleration at which engine stall occurs during normal driving (other than sports driving) (deceleration during sudden braking), for example. The deceleration determination threshold during sports driving is set to be larger than the deceleration determination threshold during normal driving ([sport driving: 0.5G]. > [Normal driving: 0.3 G] Further, the deceleration determination threshold value during sports driving is set in consideration of the danger of engine stall and the direct feeling (continuation of lock-up control) during sports driving.

  On the other hand, if the determination result in step ST3 is negative, that is, “normal driving (other than sports driving)”, the deceleration determination threshold calculation map shown in FIG. A determination threshold value (0.3G) is calculated (step ST7).

  Next, in step ST5, it is determined whether or not the vehicle deceleration detected in step ST2 is greater than the deceleration determination threshold (0.3G) calculated in step ST7.

  If the determination result in step ST5 is affirmative (vehicle deceleration> deceleration determination threshold), a lockup clutch control signal (release signal) is output to the hydraulic control circuit 300 to prevent engine stall during normal travel. Then, the lockup clutch 25 of the torque converter 2 is released (lockup release) (step ST6). If the determination result in step ST5 is negative (vehicle deceleration ≦ deceleration determination threshold), the process returns and lockup control (engagement of the lockup clutch 25) is continued.

  As described above, according to the lockup release control during deceleration of this example, the deceleration determination threshold when it is determined that the vehicle is running in sport is the deceleration determination threshold (0. 3G) is set to a larger value (0.5G), making it difficult to determine whether to release the lockup. Therefore, even if sudden braking is performed during sports driving, the lockup is released and the converter state is entered. Can be suppressed. As a result, engagement of the lockup clutch 25 can be continued, and a direct feeling (driving force controllability by the accelerator) during sports running is improved.

  In addition, during normal driving (other than sports driving), a small deceleration determination threshold value (for example, 0.3 G) that takes into account the danger of engine stall is set to make it easier to determine lockup release. When sudden braking is performed at, lockup can be reliably released. As a result, engine stall resistance during normal travel can be ensured.

  As described above, in the deceleration lock-up release control of this example, it is possible to achieve both a direct feeling during sports running (driving force controllability by the accelerator) and an engine stall resistance during normal running.

-Other embodiments-
In the above example, the deceleration determination threshold is calculated with reference to the deceleration determination threshold calculation map of FIG. 8 based on the detection information of the shift range position. However, the deceleration determination is performed by adding other parameters to the shift range position information. A threshold value may be calculated.

  For example, when the turbine rotation speed Nt of the torque converter 2 (input rotation speed of the automatic transmission 3) is small, considering that the danger of engine stall is higher than when it is large, as shown in FIG. A deceleration determination threshold value calculation map using the range position and the turbine rotation speed Nt as parameters is created, the position of the shift lever 41 (manual range or D range) detected by the shift position sensor 206, and the turbine rotation speed sensor Based on the turbine rotation speed Nt (rpm) detected by 203, the deceleration determination threshold value may be calculated with reference to the deceleration determination threshold map shown in FIG. In the deceleration determination threshold map of FIG. 9, when the turbine speed Nt is smaller than 2000 rpm, the deceleration determination threshold is set smaller than when it is large (Nt ≧ 2000 rpm).

  Further, considering that the risk of engine stall is less when the accelerator is ON than when the accelerator is OFF, the shift range position, the turbine speed Nt, and the accelerator ON / OFF are parameters as shown in FIG. A deceleration determination threshold value calculation map (deceleration determination threshold value when the accelerator is ON> deceleration determination threshold value when the accelerator is OFF) is prepared, and the position of the shift lever 41 detected by the shift position sensor 206 (manual range or D range) Based on the turbine rotation speed Nt (rpm) detected by the turbine rotation speed sensor 203 and the accelerator ON / OFF information obtained from the accelerator opening sensor 205, the deceleration determination threshold map shown in FIG. A determination threshold value may be calculated.

  Note that the deceleration determination threshold value may be calculated using a deceleration determination threshold value calculation map in which only the accelerator ON / OFF condition is added to the shift range position information.

  In the above example, the deceleration of the vehicle is detected from the output signal of the acceleration sensor. Instead of this, the vehicle speed is determined from the rate of change per unit time of the engine speed or the output shaft speed of the automatic transmission 3. Deceleration may be obtained.

  In the above example, when the shift position is in the manual range, it is determined as “sport driving”, but it may be determined by other methods whether or not it is sports driving. Specific examples are listed below.

  (1) At the time of sports driving, paying attention to the fact that the vehicle speed and the rate of change of the vehicle speed are larger than those during normal driving (other than sports driving), the vehicle speed is detected using a vehicle speed sensor, and the vehicle speed detected by the vehicle speed sensor, And when the rate of change per unit time of the vehicle speed is equal to or higher than the determination value, it is determined that the vehicle is traveling in sport.

  In this case, the determination value set for the vehicle speed and the change rate of the vehicle speed is obtained, for example, by experiment / calculation of the vehicle speed and the change rate of the vehicle speed during sports running and the vehicle speed and the change rate of the vehicle speed during normal running. A value that can discriminate between sport running and normal running based on the result may be obtained and set empirically.

  (2) At the time of sports driving, paying attention to the fact that the input speed of the automatic transmission and the rate of change of the input speed are larger than those during normal driving (other than sports driving), the input speed of the automatic transmission, that is, the torque converter If the turbine speed is detected using a turbine speed sensor, and the turbine speed detected by the turbine speed sensor and the rate of change of the turbine speed per unit time are equal to or higher than the judgment value, sports running It is determined that

  In this case, the determination value set for the turbine rotation speed and the change rate of the turbine rotation speed includes, for example, the turbine rotation speed and the turbine rotation speed change rate during sports running, and the turbine rotation speed and turbine rotation speed during normal running. The rate of change of the number may be obtained by experiments / calculations, and a value that can discriminate between sport running and normal running based on the result is obtained and set empirically.

  (3) At the time of sports driving, paying attention to the fact that the engine speed and the rate of change of the engine speed are larger than those during normal driving (other than sports driving), the engine speed is detected using an engine speed sensor; If the engine speed detected by the engine speed sensor and the rate of change of the engine speed per unit time are greater than or equal to the determination value, it is determined that the sport running.

  In this case, the determination values set for the engine speed and the engine rotation speed change rate are, for example, the engine rotation speed and engine rotation speed change rate during sports running, and the engine speed and engine rotation speed during normal driving. The rate of change of the number may be obtained by experiments / calculations, and a value that can discriminate between sport running and normal running based on the result is obtained and set empirically.

  (4) Focusing on the fact that the number of times of shifting operation during sports driving is greater than that during normal driving (other than sports driving), the number of shifting operations within a predetermined time is detected by the shifting operation number detecting means, and the shifting operation is detected. When the number of speed change operations detected by the number of times detection means is equal to or greater than a determination value, it is determined that the sport running.

  In this case, for example, the determination value set for the number of shift operations is an experiment of the number of shift operations operated within a predetermined time during sports running and the number of shift operations operated within a predetermined time during normal running. A value obtained by empirically obtaining and setting a value that can discriminate between sport running and normal running based on the result may be obtained.

  (5) When the driver has a switch for arbitrarily switching the control of the vehicle according to the driving environment such as snow mode, power (sport) mode, normal mode, etc., a mode that emphasizes sportiness by operating the switch ( When the (power mode) is selected, it is determined that the sport running.

  (6) When a navigation device is provided, if it is determined that the circuit and the winding road are running from the navigation information output by the navigation device, it is determined that the vehicle is a sports run.

  (7) Provided with a lockup mode selection switch capable of selecting a sports lockup mode (lockup clutch engagement control during sports driving) according to the driver's intention, and the lockup mode selection switch is operated (ON) The method of determining that it is sport running when it is done.

  In the above example, an example in which the present invention is applied to control of a vehicle equipped with an automatic transmission with a forward six-speed shift is shown, but the present invention is not limited to this, and planets of other arbitrary shift speeds. The present invention can also be applied to control of a vehicle equipped with a gear type automatic transmission.

  In the above example, an example in which the present invention is applied to control of a vehicle equipped with a planetary gear type transmission that sets a gear ratio using a clutch and a brake and a planetary gear device is shown. Without being limited thereto, the present invention can also be applied to control of a vehicle equipped with a belt type continuously variable transmission (CVT) having a torque converter with a lockup clutch.

  In the above example, an example in which the present invention is applied to control of a vehicle equipped with an automatic transmission having a torque converter as a fluid transmission device has been described. However, the present invention is not limited to this, and fluid coupling (locking) It can also be applied to control of a vehicle equipped with an automatic transmission having an up-clutch.

  In the above example, the example in which the present invention is applied to the control of a vehicle equipped with a gasoline engine has been shown. However, the present invention is not limited to this, and the present invention is also applicable to the control of a vehicle equipped with another engine such as a diesel engine. Applicable.

  Furthermore, the present invention is not limited to an FR (front engine / rear drive) type vehicle, but can also be applied to control of an FF (front engine / front drive) type vehicle or a four-wheel drive vehicle.

1 is a diagram illustrating a schematic configuration diagram of a vehicle to which the present invention is applied and a block diagram of a control system. FIG. It is an operation | movement table | surface of the automatic transmission shown in FIG. It is a perspective view which shows the structure of the shift lever part of a shift apparatus. It is a block diagram which shows the structure of control systems, such as ECU. It is a figure which shows an example of the shift map used for shift control. It is a figure which shows an example of the engagement map used for lockup control. It is a flowchart which shows an example of the lockup cancellation | release control at the time of deceleration. It is a figure which shows an example of the deceleration determination threshold value calculation map. It is a figure which shows the other example of a deceleration determination threshold value calculation map. It is a figure which shows another example of the deceleration determination threshold value calculation map.

Explanation of symbols

1 Engine 2 Torque Converter 25 Lockup Clutch 3 Automatic Transmission 4 Shift Device 41 Shift Lever 100 ECU
101 engine ECU
102 ECT_ECU
DESCRIPTION OF SYMBOLS 201 Engine rotational speed sensor 202 Throttle opening degree sensor 203 Turbine rotational speed sensor 204 Output shaft rotational speed sensor 205 Accelerator opening degree sensor 206 Shift position sensor 208 Vehicle speed sensor 209 Acceleration sensor 300 Hydraulic control circuit

Claims (2)

A vehicle control device equipped with an engine, an automatic transmission, and a fluid transmission device disposed between the engine and the automatic transmission,
Manual transmission means that allows the driver to arbitrarily select a shift stage or shift range of the automatic transmission, and the input side and the output side of the fluid transmission device are directly connected when a lockup condition is satisfied Lock-up control means for executing the lock-up, deceleration detection means for detecting the deceleration of the vehicle, and release of the lock-up when the deceleration detected by the deceleration detection means is equal to or greater than a deceleration determination threshold. A lock-up releasing unit; a sports travel determination unit that determines that the vehicle is in a sports mode when the manual shift is being performed by the manual transmission unit; and an accelerator detection unit that detects accelerator ON / OFF. ,
When it is determined that the sport running determination means is sport running, the deceleration determination threshold is set larger than that when the sport running determination is not performed, and when the detection result of the accelerator detecting means is accelerator ON, the accelerator OFF is set. A vehicle control apparatus characterized in that the deceleration determination threshold value is set larger than in the case. The vehicle control device according to claim 1,
Input speed detection means for detecting the input speed of the automatic transmission is provided, and when the input speed detected by the input speed detection means is small, the deceleration determination threshold is made smaller than when the input speed is high. A control apparatus for a vehicle, characterized in that the setting is performed .

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