JP5010932B2 - Shift control device for automatic transmission - Google Patents

Description

  The present invention relates to a shift control device for an automatic transmission, and more particularly to a shift control device for kickdown shift.

  In an automatic transmission for a vehicle, when the shift stage changes at more than one stage, such as during kickdown, the two or more shift valves of the hydraulic control circuit operate in an associated manner. Shift stages may be set, and shift shocks may increase.

  For example, when changing from the third forward speed to the first forward speed, two or more shift valves change, but it is possible that the fourth forward speed is set in the middle of the shift and changes from the third forward speed to the fourth speed → the first speed, There was a case where the shift shock was increased and the ride comfort was impaired.

  In order to solve such a problem, Japanese Patent Publication No. 61-58697 has a means for determining whether or not the step difference between the target shift speed and the current shift speed is 2 or more. In the case of down, an automatic transmission that first downshifts to one lower gear, holds that gear until the time determined by the timer that has been started elapses, and then downshifts to the final gear A shift control apparatus is disclosed.

  According to this speed change control device, since the intermediate speed is maintained for a predetermined time by the timer control and then the speed is changed to the final speed, it is avoided that the speed ratio is greatly changed and the engine speed increases rapidly. As a result, a large frictional force is prevented from instantaneously acting on the friction element of the friction engagement device for shift control, thereby ensuring its durability and avoiding overrun of the engine. The

  However, according to the speed change control device disclosed in the above publication, when kicking down two or more speeds, the engine speed increases rapidly by changing the speed speed by one speed at a predetermined time. The engine is not overrun, but the time held in the intermediate stage is fixed, so there is a slight time delay before switching to the final stage, and acceleration performance may be reduced. There is a problem.

  Further, it is first determined whether to shift to the target stage at a stroke or to shift one stage at a time according to the throttle opening, and then the contents of the shift control process are varied depending on whether the shift step is 2 or more. Yes. Therefore, there is a problem that a means for determining whether or not the shift step is 2 or more is necessary and that the shift control process is complicated.

As a technique for solving this problem, Japanese Patent Publication No. 8-15853 discloses a gearshift shock reduction and a gearshift control by constantly shifting gears in the order according to the gear ratio regardless of the throttle opening. In order to simplify the process, and when downshifting more than two stages, the time to be held in the intermediate stage can be changed based on the throttle opening, so that when the throttle opening is almost fully open up to the final stage A shift control device for an automatic transmission is disclosed that enables shifting in a short time and ensures acceleration performance.
Japanese Patent Publication No. 61-58697 Japanese Patent Publication No. 8-15853

  However, in the speed change control device described in Patent Document 2, in order to make a downshift determination based on the vehicle speed and the accelerator opening regardless of the driver's original intention, when the accelerator pedal is depressed deeply by an inadvertent operation, An excessive acceleration force may be generated by downshifting more than necessary, and there is a problem that drivability is deteriorated without smooth operation. In addition, fuel consumption may be deteriorated due to high rotation operation.

  The present invention has been made in view of the above points, and an object of the present invention is to generate smooth driving by generating optimal driving force characteristics for various driving operations of the driver. It is providing the shift control apparatus of the automatic transmission which becomes.

According to the present invention, in a shift control device for an automatic transmission that performs shift control using a shift map in which a plurality of upshift lines and a plurality of downshift lines are set according to a vehicle speed and an engine load, a step difference from a high shift stage. Kick-down detection means for detecting a downshift command to two or more low gears, and down based on the shift map to an intermediate gear that is one gear higher than the low gear in response to the downshift command An intermediate downshift permitting means for permitting a shift; a timer operating means for operating a timer for measuring a predetermined time when kickdown is detected by the kickdown detecting means; and after the timer counts the predetermined time , If the shift stage is the low shift stage, the shift to the low shift stage is permitted, and if the shift stage on the shift map is the intermediate shift stage, Shift control device for an automatic transmission, characterized by comprising a final gear-determining means for determining a final gear position so as to maintain the setting of the intermediate shift speed without allowing the shift to the low gear position, the Is provided.

  According to the present invention, when performing a kickdown operation of two or more stages, in order to allow a downshift to the final shift stage once the downshift to the intermediate shift stage and when the intention to accelerate continues after a predetermined period of time, Optimal driving force characteristics can be generated for various driving operations of the driver, and drivability can be improved.

  FIG. 1 is a schematic system configuration diagram of a shift control device for a vehicle automatic transmission according to an embodiment of the present invention. In FIG. 1, reference numeral 12 denotes an engine, and reference numeral 14 denotes an automatic transmission. The output of the engine 12 is transmitted to driving wheels (not shown) via the automatic transmission 14.

  The automatic transmission 14 includes a torque converter 16 and a multi-stage transmission gear mechanism 18. The torque converter 16 includes a lockup clutch (not shown), and the lockup clutch is turned on (engaged) and turned off (released) by controlling the solenoid 20 for lockup.

  In the present embodiment, the multi-speed transmission gear mechanism 18 has six forward speeds, and, as is well known, by changing the combination of excitation and demagnetization of a plurality of speed change solenoids 22 as speed change operation means, a desired speed stage can be achieved. Is set. Of course, each of the solenoids 20 and 22 switches the operation mode of the hydraulic actuator for lock-up or speed change.

  Reference numeral 24 denotes a control unit (ECU) using a microcomputer, and signals from a throttle opening sensor 26, a vehicle speed sensor 28 and a gear position sensor 30 are input to the control unit 24.

  The throttle opening sensor 26 detects the opening of the throttle valve 32, that is, the throttle opening. The vehicle speed sensor 28 detects the vehicle speed, and the gear position sensor 30 detects the current gear position of the automatic transmission 14, that is, the gear position.

  Reference numeral 34 indicates a shift position of the shift lever. As is well known, P is a parking range, R is a reverse range, and N is a neutral range. D is a drive range, and when the shift lever is in the D range, the automatic shift mode in which a shift operation or a gear ratio to be determined is determined on the basis of the running state and a shift operation is performed. S is a sport range or a manual shift range, and enables manual-like running in an automatic transmission.

  The control unit 24 further receives a shift lever position 34 and a signal from a brake switch 36 that detects the operation of the brake. The control unit 24 outputs a control signal for turning on / off the lockup clutch to the solenoid 20, and outputs a shift control signal to the solenoid 22.

  The control unit 24 basically includes a CPU, a ROM, a RAM, a clock (soft timer), an A / D converter or a D / A converter, and an input / output interface. Since it is a known configuration for use, its description is omitted.

  FIG. 2 shows a principle block diagram of the present invention. The kick-down detection means 40 detects a downshift command from a high gear to a low gear having two or more steps. When the kick-down detection means 40 detects a downshift command having a level difference of 2 or more, the intermediate downshift permission means 42 downshifts to an intermediate gear position between the high gear position and the low gear position according to the downshift command. Allow.

  The timer operating unit 44 operates a timer that measures a predetermined time when the kick down detecting unit 40 detects the kick down. The final shift speed determining means 46 determines the final shift speed according to the shift map after the timer counts a predetermined time.

  That is, when the timer counts a predetermined time, if the shift map is in the low shift stage, it is determined that the intention to accelerate continues, and the final shift stage determining means 46 permits the shift to the low shift stage. .

  On the other hand, when the timer counts the predetermined time, if the shift map is an intermediate shift stage, it is determined that the intention to accelerate is not continued due to inadvertent depression of the accelerator pedal, and the final shift stage determining means 46 determines the intermediate shift stage. Keep the stage.

  Next, the operation of the shift control device for an automatic transmission according to the embodiment of the present invention will be described with reference to the flowchart of FIG. First, in step S10, it is determined whether or not the kickdown is from the fourth, fifth or sixth gear. If the determination is affirmative, the process proceeds to step S11 and the timer A is set to a predetermined time.

  Next, in step S12, it is determined whether or not the timer A has elapsed a predetermined time. If it has not elapsed, the process proceeds to step S13 to determine whether or not the shift map is 2ND. If the determination is affirmative, the process proceeds to step S14 to permit kick-down to 3RD, and if the determination is negative, the process ends.

  When it is determined in step S12 that the timer A has elapsed, the process proceeds to step S15 to determine whether or not the shift map is 2ND. If the determination is affirmative, the process proceeds to step S16 to permit kick-down to 2ND, and if the determination is negative, 3RD in which downshift is permitted in step S14 is maintained.

  That is, in this embodiment, when there is a downshift instruction from 4th, 5th or 6th speed to 2ND, if the intention to accelerate continues after a predetermined time counted by the timer once downshifted to 3RD If the downshift to 2ND and the intention to accelerate is not continued, 3RD is maintained.

  By controlling in this way, optimal driving force characteristics can be generated for various driving operations of the driver, smooth driving is possible, and drivability can be improved.

  Next, the kick-down delay control of the present invention will be further described with reference to the time charts of FIGS. In the time chart of FIG. 4, if kickdown from the fifth speed to the second speed is made at time t1, first, a gear shift instruction to the third speed is made. In response to this, the actual gear ratio is downshifted from the fifth speed to the third speed, and the timer A is set at a time t2 delayed by a certain time from the time t1.

  At the time t3 when the timer A has elapsed for a predetermined time, the gear position on the shift map remains at the second speed, so that at time t3, a gear shift instruction to the second speed is issued and the actual gear ratio is downshifted to the second speed. .

  Therefore, in the time chart of FIG. 4, it is determined that the intention to accelerate continues after a predetermined delay time set by the timer A, and the downshift to the second speed is permitted.

  On the other hand, in the case of the time chart of FIG. 5, the kickdown from the fifth speed to the second speed is performed at the time t1, and the timer A is set at the time t2, as in the time chart of FIG. At a time t2 ′ when the timer A does not elapse for a predetermined time, the shift stage on the shift map is upshifted from the second speed to the third speed, and at the time t3 when the predetermined time elapses, the third speed is maintained on the shift map. Yes.

  Therefore, in the case of this time chart, at time t3 when the timer A has elapsed for a predetermined time, it is determined that the intention to accelerate is not continued, and the third speed is maintained without allowing the downshift to the second speed. .

  Next, the kick-down delay control according to the present invention will be described more specifically with reference to the shift maps (shift maps) shown in FIGS. These shift maps are shift maps for a six-speed automatic transmission. In each shift map, the solid line indicates an upshift line, and the alternate long and short dash line indicates a downshift line.

  Upshift lines indicated by solid lines are a 1-2 upshift line, a 2-3 upshift line, a 3-4 upshift line, a 4-5 upshift line, and a 5-6 upshift line in order from the left. Downshift lines indicated by alternate long and short dash lines are a 6-5 downshift line, a 5-4 downshift line, a 4-3 downshift line, a 3-2 downshift line, and a 2-1 downshift line in order from the right. .

  In the case shown in FIG. 6, the kickdown from the fifth speed to the second speed was made, but first, the downshift to the third speed is permitted, and the 3-2 downshift is pending. When the predetermined time set by the delay timer elapses, it is in the second speed region, and at this time, 3-2 downshift is permitted.

  On the other hand, in the case shown in FIG. 7, the kickdown from the fifth speed to the second speed was made as in the case of FIG. 6, but the accelerator pedal was returned to the third speed after a predetermined time after the delay timer passed. Therefore, 3rd speed is maintained without allowing 3-2 downshift.

  In other words, in this case, the 5-2 kickdown is once performed, but it is determined that the intention to accelerate is not continued after a predetermined time after the delay timer has elapsed, and the downshift to the second speed is not permitted. The third speed is maintained to prevent excessive acceleration force against the driver's intention.

  In the case shown in FIG. 8, the kickdown from the fourth speed to the second speed has been made, but first, the downshift to the third speed is permitted and the 3-2 downshift is pending. After the predetermined time set by the delay timer has elapsed, since the shift map is in the second speed, it is determined that the intention to accelerate continues, and the downshift to the second speed is permitted.

  On the other hand, in the case shown in FIG. 9, the kickdown from the 4th speed to the 2nd speed was made as in the case shown in FIG. 8, but the accelerator pedal returned after a predetermined delay time set by the delay timer. Since it is in the third speed region on the shift map, it is determined that the intention to accelerate is not continued, and the third speed is maintained without allowing downshift to the second speed.

1 is a schematic system configuration diagram of a shift control device for an automatic transmission according to an embodiment of the present invention. It is a principle block diagram which shows the principle of this invention. It is a flowchart which shows the effect | action of the transmission control apparatus of this invention embodiment. It is a time chart of the embodiment of the present invention (the 1). It is a time chart of embodiment of this invention (the 2). It is a shift map explaining the 5-2 kickdown of embodiment of this invention. FIG. 7 is a shift map similar to FIG. 6 but illustrating that 3-2 downshift is not allowed after a predetermined delay time. It is a shift map explaining 4-2 kickdown of this invention embodiment. FIG. 9 is a shift map similar to FIG. 8 but illustrating that 3-2 downshift is not allowed after a predetermined delay time.

Explanation of symbols

12 Engine 14 Automatic transmission 24 Control unit (ECU)
26 Throttle opening sensor 28 Vehicle speed sensor 30 Gear position sensor 36 Brake switch 40 Kick down detection means 42 Intermediate down shift permission means 44 Timer operation means 46 Final gear stage determination means

Claims (1)

In a shift control device for an automatic transmission that performs shift control using a shift map in which a plurality of upshift lines and a plurality of downshift lines are set according to a vehicle speed and an engine load,
Kick-down detection means for detecting a downshift command from a high gear to a low gear having two or more steps;
An intermediate downshift permission means for permitting a downshift based on the shift map to an intermediate shift speed that is one shift speed higher than the low shift speed in response to the downshift command;
Timer actuating means for actuating a timer for measuring a predetermined time when kick down is detected by the kick down detecting means;
After the timer counts the predetermined time , if the shift stage on the shift map is the low shift stage, the shift to the low shift stage is permitted, and the shift stage on the shift map is the intermediate shift stage. A final shift speed determining means for determining a final shift speed so as to maintain the setting of the intermediate shift speed without allowing a shift to the low shift speed ;
A shift control device for an automatic transmission, comprising: