JPH0481064B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an automatic transmission that transmits power from an engine to driving wheels to drive a vehicle, and particularly relates to an electronically controlled automatic transmission. (Prior art) An automatic transmission is constructed to select a predetermined gear ratio by shifting according to the main vehicle speed and throttle opening according to the standard pattern shown by the solid line in FIG. In the case of an automatic transmission, a power pattern in which a part of the gear shift line is shifted to the high vehicle speed side, as shown by the dotted line in Fig. 7, is selected and used, especially when climbing a hill or accelerating. It can be configured to change gears along the following lines. In fact, the applicant has already introduced this type of electronically controlled automatic transmission in "Nitsun Service Bulletin" No. 484, published in June 1988. As described on pages 225 to 227 of the above-mentioned document, this automatic transmission can be used when climbing hills or accelerating with the driver turning off the power shift switch to automatically switch between the standard pattern and the power pattern. The vehicle is configured so that the power pattern is selectively used during driving that requires power, and the standard pattern is selectively used during other normal driving. Then, the return from the power pattern to the standard pattern is performed by releasing the accelerator pedal.
Even if you release the accelerator pedal once before a curve when climbing a hill, there is a slight time lag before it returns, assuming that you want to accelerate again immediately. (Problem to be solved by the invention) However, with such a slight time lag, when driving on a winding road, curves in one direction continue for a relatively long time, or curves to the left alternate in succession. , while driving through continuous turns on a road with many curves, if you release the accelerator pedal before the curve and hold it there, the power pattern will switch from the standard pattern in the middle of the curve, and the automatic transmission will shift up to reduce the reduction in driving force. Then, when the accelerator pedal is pressed after passing a curve, the standard pattern returns to the power pattern, causing unnecessary gear shifting and impairing driveability, just as an automatic transmission downshifts and generates a sudden increase in driving force. The problem was that it got worse. (Means for Solving the Problem) The present invention provides a system in which a vehicle enters a road with many curves, such as a winding road, and the driver releases the accelerator pedal while the automatic transmission is automatically selecting a power pattern. In addition, when a steering operation is performed to increase the steering angle or the steering frequency, the shift control based on the power pattern is maintained, thereby solving the above-mentioned problems. That is, as shown in FIG. 1, the present invention transmits the power from the engine to the driving wheels by changing the speed appropriately,
An automatic transmission that causes the vehicle to travel and performs the gear shift based on a predetermined shift pattern, wherein the shift pattern includes a first shift pattern and a shift point on a higher vehicle speed side than the first shift pattern. an automatic transmission comprising a shift pattern automatic switching means 2 that holds a certain second shift pattern and automatically switches between the first shift pattern and the second shift pattern according to the accelerator opening of the vehicle. 1, continuous turning detection for detecting that the accelerator pedal is released and the steering angle or steering frequency is greater than or equal to a set value indicating continuous turning based on the accelerator opening and steering operation of the vehicle; Means 3
and, while the automatic shift pattern switching means automatically selects the second shift pattern, if the continuous turning detection means detects that the vehicle is running in the continuous turning, the automatic shift pattern is automatically selected. The present invention is characterized by being provided with turning shift pattern maintaining means 4 for causing the switching means to maintain the second shift pattern for a set time sufficient to complete the continuous turning travel. (Function) In such an automatic transmission, while the shift pattern automatic switching means 2 automatically selects the second pattern, the continuous turning running detection means 3 detects a change in speed based on the accelerator opening and steering operation of the vehicle. , the accelerator pedal is released, and the steering angle or steering frequency is
If it is detected that the value is equal to or higher than the set value indicating that continuous turning is being performed, the turning shift pattern maintaining means 4 causes the automatic speed change pattern switching means 2 to change the second shift pattern to end the continuous turning. It is maintained for a set period of time sufficient to ensure that the Therefore, according to the automatic transmission of the present invention, while the vehicle is traveling in the second shift pattern, the vehicle may be traveling around a relatively long curve or several consecutive small curves on a winding road, etc. If the driver releases the accelerator pedal and performs an operation to increase the steering angle or steering frequency to the above set value or more after the continuous turning operation has started, the continuous turning operation will continue until the continuous turning operation is substantially completed. During the continuous turning, the second shift pattern in which the shift point is on the relatively high vehicle speed side is maintained and the shift point is prevented from shifting to the low vehicle speed side. Even if the accelerator pedal is continued, no unnecessary upshifts will occur, and therefore, even if the accelerator pedal is subsequently depressed, unnecessary downshifts will not occur, and only the second shift pattern will be used. This prevents unexpected gear shifts and sudden changes in driving force, and enables responsive re-acceleration at the end of a turn, improving drivability and increasing the product value of automatic transmissions. . (Example) Hereinafter, an example of the present invention will be described in detail based on the drawings. FIG. 2 is a schematic diagram showing an embodiment of the present invention, in which 10 is an electronically controlled automatic transmission, 11 is a valve body for controlling the speed change, 12 to 14 are shift solenoids, and 12 is 1- 2 shift solenoid, 13 is 2-3 shift solenoid, 14 is 3-
It is a 4 shift solenoid. In addition, automatic transmission 1
0 is a 4-speed automatic transmission, and by switching the 1-2 shift solenoid 12 ON and OFF, the gear is shifted 1←→2, and by switching the 2-3 shift solenoid 13 ON and OFF, the gear is shifted 2←→, and the gear is shifted 3-4. 3←→4 gears are changed by switching the solenoid 14 ON and OFF, and 1st to 4th speeds are selected by the combinations of ON and OFF of these shift solenoids shown in the table below. Since this is not related to the invention, the explanation will be omitted.

[Table] The shift solenoids 12 to 14 are individually controlled ON and OFF by the controller 15, and the controller 15 is configured to turn ON when the driver desires a power pattern as the second shift pattern, and to control the power pattern and the first shift pattern. A signal S _P from the pattern switch 16, which is turned OFF when automatic pattern switching between standard patterns as a speed change pattern is desired, and a signal from the throttle opening sensor 17, which detects the engine throttle opening TH. , a signal from the vehicle speed sensor 18 that detects the vehicle speed V, and a signal from the steering angle sensor 19 that emits a pulse signal at every fixed rotation angle of the steering wheel.
S _S , and an inhibitor switch 20 that detects the forward travel range of the automatic transmission, that is, the forward automatic shift travel (D) range, the 2nd speed engine brake travel () range, and the 1st speed engine brake travel () range.
Input the signals S _R from the respective terminals. The controller 15 is constituted by a microcomputer, and based on the input information, executes the control programs shown in FIGS. 3 to 5 to select a pattern, and also performs automatic gear shifting in accordance with the selected pattern. The standard pattern here is also the same as the conventional pattern shown by the solid line in Figure 7.
The shift point is on the relatively low vehicle speed side and corresponds to normal driving, and the power pattern here is similar to that of the conventional vehicle shown by the broken line in FIG.
The gear shift point is located on the relatively high vehicle speed side and corresponds to driving under predetermined conditions such as when climbing a hill or accelerating. FIG. 3 shows the main routine, which is repeatedly executed during engine operation, and first, in step 30, the power flag POWFLG is checked. As will be described later, this power flag is set to 1 while the power pattern is selected when the driver turns off the pattern switch 16 and desires automatic switching between the standard pattern and the power pattern; In other words, it is reset to 0 during standard pattern selection or power pattern selection with pattern switch 16 turned on. If POWFLG = 0, check whether the pattern switch 16 is ON or OFF from the signal S _P in step 31, and if it is OFF, the throttle opening TH is determined in step 32.
In step 33, the vehicle speed V is sequentially read. In the next step 34, from the table data of the set throttle opening increment (dTH/dt) _Ref , which is the criterion for pattern switching set by the combination of throttle opening TH and vehicle speed V, the current throttle opening increment ( dTH/dt) Pulls up _{the Ref} table. In the next step 35, the rate of change of the throttle opening TH (dTH/dt) is calculated and it is determined whether or not this is greater than or equal to the set speed (dTH/dt) _Ref . If it is greater than the set speed (dTH/dt) Ref, it is determined that the vehicle is accelerating suddenly or climbing a slope. After setting the power flag POWFLG to 1 in step 36, a power pattern is selected in step 37, and if not, a standard pattern is selected in step 38. In addition,
If you want to determine that the power pattern is desired by turning on the pattern switch 16 in step 31,
By executing step 37, the power pattern is selected unconditionally. Therefore, the controller 15 performs these steps.
By executing steps 31 to 38, the automatic shift pattern switching means 2 is configured. When determining POWFLG=1 in step 30,
In other words, if the power pattern is automatically selected, the control proceeds to step 39 and the idle flag is set.
Check IDLFLG. This idol flag
IDLFLG is set to 01 or 10 when the throttle opening TH is fully closed as described later, and is set to 00 after the set time T ₁ or T ₂ .
shall be returned to. If IDLFLG=00, the throttle opening TH is read in step 40, and in the next step 41 it is determined whether this is a fully closed accelerator pedal release state or not. If the accelerator pedal is not released, proceed to step 37 to continue selecting the power pattern; if the accelerator pedal is released, proceed to step 37.
At 42, the number N of steering pulses is read out. The number N of steering pulses is determined by reading and storing the count value of a counter that counts up the pulse signal S _S from the steering angle sensor 19 (see FIG. 2) using the regular interrupt routine shown in FIG.
It is assumed that this count value is obtained by reading out this count value when executing 42. The interrupt routine shown in FIG. 4 is repeatedly executed every fixed time ΔT. First, the power flag POWFLG is checked in step 60, and if the standard pattern is 0 or the power pattern is being manually selected, the counter is cleared in step 61. Then, in step 62, control is returned to the main routine shown in Fig. 3, and only during automatic power pattern selection with POWFLG = 1, the count value of the above counter is read and stored in step 63, and then step 63 is executed.
Control proceeds to 61 and 62. By the way, when traveling in a straight line as shown in Fig. 6 a and b, the interrupt interval ΔT of the routine shown in Fig. 4 is
During continuous turning on roads with continuous _curves such as winding roads, the frequency of steering is high or the steering angle is large, that is, the amount of steering operation is large, so the interruption interval ΔT is low. There are many pulse signals S _S in . Therefore, the count value read in step 63 in FIG.
That is, the number N of steering pulses read out in step 42 in FIG.
It is possible to determine whether the vehicle is continuously turning or not based on whether or not there are many. In the next step 43 in FIG. 3, it is determined whether the number of steering pulses N is greater than or equal to a set value N _R indicating continuous turning, that is, whether or not the vehicle is turning. If not, step 44 is performed. idol flag
After setting IDLFLG to 01, reset the idle timer in step 45, and if N≧N _R , proceed to step 46.
After setting the idle flag IDLFLG to 10 in step 47, the idle timer is reset. From step 45 or 47, control advances to step 37 to continue selecting the power pattern. After IDLFLG becomes 01 or 10 as described above, step 39 selects step 48 to check whether the above-mentioned timer or timer indicates the post-reset set time T ₁ or T ₂ or not. If , check the timer, if 10, check about the timer. Note that the set time T ₁ is the delay time for switching from the power pattern to the standard pattern when not running in continuous turns, so it is about the time lag described above, but the set time T ₂ is the delay time for switching the pattern when running in continuous turns. , the length is set to be relatively long enough to complete one relatively long curve or several successive small curves. While it is determined in step 48 that timer≠ _T1 or timer≠ _T2 ,
After incrementing the corresponding timer in step 49, the power pattern continues to be selected in step 37, and when timer = T ₁ or timer = T ₂ , the idle flag IDLFLG and After resetting the power flags POWFLG to 00 and 0, respectively, the pattern is switched to the standard pattern in step 38. Therefore, the controller 15 performs the above step 40.
Continuous turning running detection means 3 by executing ~47
The turning control continuation means 4 is constructed by further executing steps 30, 38, 48 to 51 described above. In step 52, based on the standard pattern selected in step 18 or the power pattern selected in step 37, the automatic transmission is controlled by executing the control program shown in FIG. That is, first, in step 70, the throttle opening TH and vehicle speed V are read, and in the next step 71, it is determined from the signal S _R whether or not the vehicle is in the D range.
For D range, step 72, shift solenoid 1
The currently selected gear position is read from the ON/OFF combinations 2 to 14, and in the next step 73, the throttle opening and the upshift vehicle speed are changed from the current gear position to V ₁₂ (in 1st gear) based on the aforementioned selection pattern. , V ₂₃ (Second
V ₃₄ (at 3rd gear) and downshift vehicle speeds V ₄₃ (at 4th gear), V ₃₂ (at 3rd gear), and V ₂₁ (at 2nd gear) are table-picked up. Steps 74, 75, and 76 determine whether the current gear is 4th, 3rd, or 2nd. The control proceeds to step 79, and the control proceeds to step 76.
When the first speed is determined to be N ₀ , the control proceeds to step 80. In step 77, it is determined whether V≦V ₄₃ ,
If not, shift solenoids 12 to 14 are turned ON and OFF so that 4th gear is held in step 81.
If so, in step 82, the shift solenoids 12 to 14 are commanded to be turned on or off so that a downshift to third gear is performed. step
At step 78, it is determined whether V≧V ₃₄ or not, and if so, at step 81, shift solenoids 12 to 14 are turned on so that an upshift to 4th gear is performed.
Command OFF, otherwise turn V in step 83.
Determine whether ≧V ₃₂ . If V≦V ₃₂ , step
At step 84, the shift solenoids 12 to 14 are commanded to be turned on and off so that a downshift to the second gear is performed, and if V≦V ₃₂ , the shift solenoids 12 to 14 are commanded to maintain the third gear at step 82. 14 of
Command ON and OFF. In step 79, V≧V ₂₃
If so, the third step is performed in step 82.
The shift solenoids 12 to 14 are commanded to be turned on and off so that an upshift to a higher speed is performed, and if not, it is determined in step 85 whether or not V≦V ₂₁ . The shift solenoid 12 is such that if V≦V ₂₁ , a downshift to first gear is performed in step 86.
- 14 are commanded to turn on and off, and if V≦V ₂₁ does not hold, the shift solenoids 12 to 14 are commanded to be turned on and off so that the second speed is maintained at step 84.
In step 80, it is determined whether V≧V ₁₂ or not, and if so, in step 84, shift solenoids 12 to 14 are turned ON so as to perform an upshift to the second speed.
Shift solenoid 12 to OFF, otherwise first gear is held at step 86.
Command 14 to turn on and off. Shift solenoid for steps 81, 82, 84 or 86
The ON and OFF commands are outputted to the corresponding shift solenoids 12 to 14 in step 87, and the automatic transmission can be controlled to shift to a state where the gear position according to the command is selected. By the way, the standard pattern and power pattern on which this shift control is based are selected as described above with reference to FIG. By increasing the frequency, if it is determined that the vehicle is making continuous turns, it will switch to the standard pattern for the set period of time.
Since this is carried out after T ₂ has elapsed, the power pattern is substantially maintained during the continuous turning. Therefore, during continuous turning, the shift point is prevented from shifting from the high vehicle speed side to the low vehicle speed side, so even if the accelerator pedal is released for a certain period of time, the automatic transmission will not be required to upshift due to a decrease in vehicle speed. Therefore, even if the accelerator pedal is subsequently depressed, an unnecessary downshift will not occur, and the power pattern at the start of the turn will be maintained until the end of the turn, which is contrary to the driver's wishes. Inadvertent gear shifts and changes in driving force are prevented, and re-acceleration at the end of a turn can be performed with good response, improving drivability and increasing the commercial value of automatic transmissions. Furthermore, if the accelerator pedal is depressed when the timer reaches _T2 and the process advances from step 51 to step 38 and the power pattern is switched to the standard pattern, an upshift will be performed as shown in Figure 7. Since the program enters the next cycle without stopping and switches to the power pattern again, the power pattern can be continued even after the turn is completed. Next, if it is determined in step 71 that the vehicle is not in the D range, it is determined in step 88 whether or not it is in the range from the signal S _R. limit value
V Determine whether it is _1M or more, and if so, step
2nd speed is selected in the range by steps 84 and 87 to prevent engine overspeed, and only when this is not the case is the first speed fixed in steps 86 and 87. When selecting a range that is determined to be out of range in step 88, the vehicle speed V is set to the second range in step 90.
Limit value V _2M that causes engine overspeed at speed
If so, step 82,
87 selects third speed in the range to prevent engine overspeed, otherwise steps 84 and 87 fix it to second speed. In addition, in the above-mentioned embodiment, the case where the power pattern shown in FIG. 7 is also used as the second shift pattern was explained as an example, but it goes without saying that the second shift pattern is only used for continuous turning when the shift point is on the relatively high vehicle speed side. You may also set a pattern. (Effects of the Invention) As described above, according to the automatic transmission of the present invention, while the vehicle is traveling in the second shift pattern, the vehicle is traveling on a relatively long curve or several consecutive curves on a winding road, etc. If the driver releases the accelerator pedal and performs an operation to increase the steering angle or steering frequency to a set value or more after the vehicle enters a continuous turning operation that involves traveling around a small curve, the continuous turning operation will be stopped. The second shift pattern, in which the shift point is on the relatively high vehicle speed side, is maintained until the end of the continuous turning, and the shift of the shift point to the low vehicle speed side is prevented. , even if the accelerator pedal is released for a certain period of time, an unnecessary upshift will not occur, and even if the accelerator pedal is subsequently depressed, an unnecessary downshift will not occur, and only the second shift pattern will be used. This prevents accidental gear shifts and sudden changes in driving force that do not meet the driver's wishes, and also makes it possible to re-accelerate after turning with good response, improving drivability and improving automatic transmission performance. Product value can be increased.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of the automatic transmission of the present invention, Fig. 2 is a system diagram showing an embodiment of the present invention, Figs. FIG. 6 is a time chart showing that the steering pulses are different when traveling on a straight road and when traveling in a corner, and FIG. 7 is a shift pattern diagram showing a standard pattern and a power pattern. 1... Automatic transmission, 2... Turning detection means,
3... Normal speed change control means, 4... Turning speed change control means, 5... Switching means, 10... Electronically controlled automatic transmission, 11... Valve body, 12... 1-
2 shift solenoid, 13...2-3 shift solenoid, 14...3-4 shift solenoid, 15
...Controller, 16...Pattern switch,
17...Throttle opening sensor, 18...Vehicle speed sensor, 19...Steering angle sensor, 20...Inhibitor switch.

Claims (1)

[Scope of Claims] 1. An automatic transmission that appropriately changes the speed of power from an engine to transmit power to the drive wheels to drive the vehicle, and that changes the speed based on a predetermined speed change pattern, wherein the speed change pattern is: A first shift pattern and a second shift pattern in which the shift point is on the higher vehicle speed side than the first shift pattern are maintained, and the first shift pattern and the second shift pattern are changed by changing the accelerator of the vehicle. In an automatic transmission equipped with means for automatically switching gear shift patterns according to the opening degree of the vehicle, based on the accelerator opening degree and steering operation of the vehicle,
continuous turning detection means for detecting that the accelerator pedal is released and the steering angle or steering frequency is equal to or higher than a set value indicating continuous turning; If the continuous turning detecting means detects that the vehicle is in the continuous turning while automatically selecting the pattern, the automatic shift pattern switching means changes the second shift pattern to the continuous turning. An automatic transmission characterized by comprising: means for maintaining a shift pattern during turning for a set time sufficient for the shift pattern to be completed.