JPS63270961A - Controller for automatic transmission - Google Patents

Abstract

PURPOSE:To make favolable accelerability securable at time of driving over highland by installing a shift pattern altering device which alters a shift pattern to the highland pattern set in a direction of checking the shift-up to the maximum speed at time of highland travel. CONSTITUTION:When a fact that a running ground is of highland is detected by a highland travel detecting device D, shift speed will not come to be shifted up to the maximum speed especially by a shift pattern altering device E. Accordingly, in spite of a shortage of engine output due to a drop in atmospheric pressure, the required driving force comes to be secured. With this constitution, favorable accelerability comes to be securable even at time of highland travel.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for an automatic transmission mounted on a vehicle.

(Prior Art) Generally, in an automatic transmission, a shift pattern is set in advance using vehicle speed and engine load as parameters, and this shift pattern and actual driving conditions are determined in advance. 9 (vehicle speed and load) and whether or not to shift up the gear.
Alternatively, it is determined whether or not to downshift or not, and the gear position is controlled according to the result of the determination. has been shown to change. This is achieved by using a pattern in which each shift line is shifted to a higher speed side than the normal shift pattern when driving at high altitudes, where engine output generally decreases due to a drop in atmospheric pressure. According to this, the lack of engine output is compensated for by the transmission, and acceleration and drivability when driving at high altitudes are improved.

(Problems to be Solved by the Invention) By the way, the method disclosed in the above publication only changes the shift pattern to shift the shift line to a higher vehicle speed side when driving at high altitudes. The only difference is that the upshift is delayed, and as the speed increases, the gears are sequentially shifted up to the highest gear, as in the conventional case. Therefore, when driving at high altitudes, the gear may be shifted up to the highest speed such as overdrive, and in such a case, a problem arises in that the driving force is insufficient and the required acceleration cannot be obtained.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a vehicle equipped with an automatic transmission that upshifts or downshifts gears according to a shift pattern, and prevents upshifting to the highest gear when driving at high altitudes, especially when accelerating. It is an object of the present invention to provide a structure in which a required driving force is ensured regardless of a lack of engine output, thereby providing good acceleration performance even when driving at high altitudes.

(Means for Solving the Problems) In order to achieve the above object, an automatic transmission control device according to the present invention is characterized in that it is configured as follows.

That is, as shown in FIG. 1, a shift control means C controls the gear position by comparing the operating state such as the vehicle speed and engine load detected by the operating state detection means B with a preset shift pattern. The equipped automatic transmission A includes a high-altitude traveling detection means for detecting whether or not the vehicle is traveling on a highland, and when the detecting means detects that the vehicle is traveling on a highland, the above-mentioned The present invention is characterized by comprising a shift pattern changing means E for changing the shift pattern to a high altitude pattern set in a direction to prevent upshifting to the highest gear. The above-mentioned high-altitude pattern may be one that completely prevents the use of the highest gear, but in low-load areas where acceleration is not required, upshifting to the highest speed is allowed to improve fuel efficiency. It may be configured to do so.

(Function) According to the above configuration, when driving at high altitudes, especially when accelerating at high altitudes, the gear position is not shifted up to the highest gear position, and therefore, the gear position is not shifted up to the highest gear position, even though the engine output is insufficient due to a decrease in atmospheric pressure. First, the required driving force is ensured. As a result, good acceleration performance can be obtained even when driving at high altitudes.

(Example) Examples of the present invention will be described below. This embodiment relates to an automatic transmission applied to an engine equipped with a throttle valve control device that electrically controls the opening degree of the throttle valve in accordance with the amount of accelerator depression.

As shown in FIG. 2, in the engine 1 according to this embodiment, the throttle valve 3 provided in the intake passage 2 is
It is designed to be opened and closed by an actuator 4 such as a motor. Further, the automatic transmission 5 coupled to the engine 1 has a plurality of shift solenoids 61, 6□, 63 and a lock-up solenoid 7. The combination of ON and OFF switches the hydraulic circuit and selectively engages a plurality of hydraulic engagement elements, thereby switching the transmission mechanism to a plurality of gear stages. A lock-up clutch (not shown) in the torque converter is engaged or released by turning ON or OFF.

Then, the actuator 4 for driving the throttle valve, and the solenoids 61 to 63, 7 for shifting and locking up.
A controller 10 outputs a throttle control signal a, a shift control signal and a lock-up control signal C, respectively.
The controller 10 includes an accelerator sensor 11 that detects the amount of depression of the accelerator pedal, a vehicle speed sensor 12 that detects the vehicle speed, and a gear position sensor 13 that detects the gear position (gear stage) of the transmission 5. Output signals d, e, f, g, h from the atmospheric pressure sensor 14 that detects atmospheric pressure and the mode lever 15 that sets the operation mode
is now entered. Here, the mode lever 15 is used to set or change the driving mode stepwise or steplessly between an economy mode that emphasizes fuel efficiency and a power mode that emphasizes output performance. It is designed to output a signal with a value corresponding to the selected mode.

Next, the operation of this embodiment will be explained according to a flowchart showing the operation of the controller 10.

As shown in FIG. 3, this controller 10 performs a predetermined system initialization at the start of operation, and then controls the opening degree of the throttle valve 3 via the actuator 4 based on the signal a. , c control the gear position of the automatic transmission 5 and the lock-up clutch via the solenoids 61 to 6° and 7.

Specifically, the throttle control described above is performed according to the flowchart shown in FIG. In other words, controller 10
First, the accelerator pedal depression amount α, vehicle speed ■, gear position G, atmospheric pressure P, and driving mode M are determined based on signals d to h from each sensor 11 to 14 and mode lever 15 shown in FIG. Input the above accelerator depression amount α
Calculate the temporal rate of change α' (steps 81 to S6)
.

Then, the controller 10 determines the value of a flag F indicating whether the driving area at the time of the previous control was a lowland or a highland. It is determined whether or not is less than a first predetermined value P1 (for example, 0.7 atmospheres).

If the running area has moved to a highland at the time of the current control, p<p, so the flag F is set to "1" (steps S to S9).

Further, the value of the flag F at the time of the previous control is "1", and the atmospheric pressure P measured this time is the second predetermined value P2.
(for example, 0.8 atm) or lower, that is, if high-altitude driving continues, keep the flag F at "1" and
When the atmospheric pressure P exceeds the second predetermined value P2, that is, when the driving area changes from a highland to a lowland, the flag F is reset to "0" (step Slo, 5tt) *This causes the current driving area to change. If it is a lowland, F=0, if it is a highland, F=1.

Next, the controller 10 determines a function value f(α), which is the basis of the throttle opening based on the accelerator depression amount α, according to the characteristics shown in FIG. 5 (step 512). This characteristic is determined for each gear position G. The map is set in advance so that the function value f(α) increases as the accelerator depression amount α increases, and the function value f( α) is set to be large.

Then, the controller 10 determines the value of the flag F, and when F=O, that is, when driving on a low land, the controller 10 determines the accelerator depression amount based on the rate of change α' of the accelerator depression amount α, the vehicle speed V, and the driving mode M. Find the throttle opening gain (throttle gain) K with respect to α (step 51318
14) As shown in FIG. 6, this throttle gain has a value of, for example, 1.0 to 1.2 relative to the integrated value ((2'
It is set linearly within the range of . In other words, the output is required as the values of the above-mentioned depression amount change rate α', vehicle speed V, and driving mode M increase, and by increasing the throttle gain K according to the multiplicative product of these values, , the throttle opening degree is increased for the same accelerator depression amount α, and the correction is made so that the required output can be obtained.

On the other hand, when the flag F is "1", that is, when driving at high altitudes, the throttle gain K is unconditionally set to the maximum value ■a
x(1,2) (step 515), and
Using the throttle gain K thus obtained, the function value f(
α), the throttle opening θ (=KXf(α)) according to the accelerator depression amount α is calculated, and the throttle valve 3
A control signal a is output to the actuator 4 shown in FIG. 2 so that the opening degree θ becomes the opening degree θ (step S16+31
7).

As described above, the throttle opening θ is controlled with respect to the accelerator depression amount α, but as mentioned above, when driving at high altitudes, the throttle gain K is always at the maximum value K.
+*ax, so even if the engine output generally decreases, good acceleration can be obtained without requiring extreme depression of the accelerator pedal.

On the other hand, automatic shift control fi5 is performed according to the flowchart shown in FIG.

In this control as well, the controller 10 first inputs the accelerator depression amount α and the vehicle speed V (steps /Tl, T
2), and this accelerator depression amount α and vehicle speed V,
By comparing the upshift line and downshift line in a shift pattern set in advance using these as parameters, it is determined whether the gear position should be shifted up or down.

Furthermore, by comparing the accelerator depression amount α and vehicle speed V with a lock-up pattern using these as parameters, it is determined whether or not to engage the lock-up clutch, and the gear position is adjusted according to the results of these determinations. In order to shift up or down, and to engage or release the lock-up clutch, control signals s and c are output to the shift solenoids 61 to 63 and the lock-up solenoid 7 shown in FIG. 2, respectively. (StempT, ~T6).

Specifically, the above-described determination of upshifting is performed as follows according to the flowchart of FIG.

That is, the controller 10 first determines the current gear position G of the automatic transmission 5 based on the signal f from the gear position sensor 13 (steps T1' to T,'). Then, in the case of 4th speed (G = 4), which is the highest speed, no upshift judgment is performed, and in the case of 3rd speed (G = 3), step T
4' to T9', step Tt in the case of 2nd speed (G=2).

In accordance with steps T19' to T18', and in the case of 1st speed (G=1), shift door/yp determination is performed in accordance with steps T19' to Too', respectively.

In any of these upshift determinations, the value of the flag F used in the throttle control is first determined (step T4', Tro').

T19'), and when F=O, that is, when driving on low ground, each shift up of 1-2, 2-3 shown by the solid line in the shift pattern in which the accelerator depression amount and vehicle speed are variables as shown in FIG. Driving region R (α
, ■). In other words, in the case of 3rd gear, if the region R (α, ■) is on the high vehicle speed side of the normal 3-4 shift up line L34, it will shift up to 4th gear, and if it is on the low vehicle speed side, it will shift up to 3rd gear. It is determined that it should be retained (step T', Ts'). In addition, in the case of 2nd speed, if the region R (α, V) is on the high vehicle speed side of the normal 3-4 shift up line L34, it will shift up to 4th speed, and if it is on the low vehicle speed side of the line L34. , 2-3 shift up If the vehicle speed is on the high vehicle speed side of line L2B, shift up to 3rd gear, and if the vehicle speed is on the low vehicle speed side of line L2B, shift up to 3rd gear.
It is determined that it should be held quickly (step T13',
T16', T1゜'), furthermore, in the case of 1st speed, the region R (α, V) is the normal 3-4 shift up line L3
If the vehicle speed is on the high vehicle speed side of line L34, the vehicle shifts up to 4th gear, and if the vehicle speed is on the low vehicle speed side of line L34, and the vehicle speed is on the high vehicle speed side of 2-3 shift up line L23, the vehicle shifts up to 3rd gear. If it is on the low vehicle speed side of line L2S and on the high vehicle speed side of 1-2 shift up line L12, it will shift up to 2nd gear, and if it is on the low vehicle speed side of line L12, it will shift up to 2nd gear.
It is determined that it should be held quickly (step T22'・T
25', T28', T29').

On the other hand, when the flag F is "1", that is, when traveling at high altitude, the controller 10 changes the speed change pattern shown in FIG. Read the 3-4 shift up line L'34 for highland driving shown in (steps T9', T18', T
,,'), the operating region R(α, ■) is the line L'3
4, the gear position G is shifted up to 4th speed only when the vehicle speed is on the high speed side (low accelerator depression amount side). In that case, this 3-4 shift up line L'34 for high altitude driving
is set so that the 4th speed region partitioned by the normal 3-4 shift up line L34 becomes the 3rd speed region except for the low load region (shaded area) where the accelerator depression amount α is 1/8 or less. This means that when driving at high altitudes, the gear will not be shifted up to 4th speed when the accelerator depression amount α is 1/8 or more. As a result, when driving at high altitudes where the engine output decreases, upshifting of the gear position G is basically limited to 3rd speed, thereby ensuring the required driving force. Even when driving at high altitudes, upshifting to 4th gear is permitted in low load areas (1/8 or less of the accelerator pedal depression) where no driving force is required, such as during deceleration. This avoids the problem of unnecessarily deteriorating fuel efficiency, which would occur if the engine is always prevented.

Here, since the engine output decreases as the atmospheric pressure decreases (as the altitude increases), it is necessary to set a region that prevents upshifting to 4th gear in response to this decrease in engine output, depending on the atmospheric pressure. is possible. In other words, as shown by the chain line in Fig. 9, as a 3-4 shift up line in the shift pattern, there is a gap between the normal (low altitude) line L34 and the high altitude lines L' and 4 depending on the altitude. A plurality of lines L''34+L'''34 are provided, and the fourth speed range becomes narrower as the altitude increases. In this way, the range in which upshifts are restricted to 3rd gear will be expanded as the engine output decreases as the altitude increases, and the 4th gear range will be made narrower than necessary while always ensuring the required driving force. Deterioration of fuel efficiency will be avoided.

Incidentally, the downshift determination at step T4 in FIG. 7 is as follows:
Specifically, this is carried out according to the flowchart shown in FIG. That is, as in the case of the above-mentioned shift-up determination, the gear position G is first determined (steps T1'' to T3
''), and in the case of 1st gear (G = 1), which is the lowest gear, no downshift determination is performed, and in the case of 2nd gear (G = 2), 3rd gear (G =3)
In the case of 4th gear (G
= 4), the upshift determination is performed according to steps T15'' to T24'', and these upshift determinations are all performed in accordance with 4-3.3 of the shift pattern shown in FIG.
-2.2-1 each shift down line'+43+J
32. This is done by comparing J 21 with the actual driving range R (α, ■). In other words, in the case of 2nd speed, the region R (α, V) is the 2-1 shift down line fI2
If the vehicle speed is on the low vehicle speed side of 1, it is determined that the shift is down to the first speed, and if the vehicle speed is on the high vehicle speed side, it is determined that the second speed should be maintained (steps T6'', T7''). In addition, in the case of 3rd speed, area R
If (α, ■) is on the low vehicle speed side of the 2-1 shift down line 121, the shift is down to 1st gear, and the line J21 is shifted down to 1st gear.
on the high road side, and the 3-2 shift down line β, 2
If the vehicle speed is on the low vehicle speed side of line ρ32, it is determined that the shift is down to 2nd gear, and if the vehicle speed is on the high vehicle speed side of line ρ32, it is determined that 3rd gear should be maintained (step Tl.

, T13'', TI4''), and in the case of 4th speed, region R
If (α, ■) is on the low vehicle speed side of the 2-1 shift down line f21, the shift is down to 1st gear, and the corresponding line ρ21
on the high vehicle speed side of 3-2 shift down lines 1 and 2.
If the vehicle speed is on the low vehicle speed side of line ρ32, it is shifted down to 2nd gear, and if the vehicle speed is on the high vehicle speed side of line ρ32 and the vehicle speed is on the low vehicle speed side of 4-3 shift down line -043, it is shifted down to 3rd gear. If the vehicle speed is on the high vehicle speed side of the line ρ4°, it is determined that 4th gear should be maintained (steps T17'', T2O
"r723", 724").

(Effects of the Invention) As described above, according to the present invention, it is possible to prevent the automatic transmission from shifting up to the highest speed when driving at high altitudes, especially when accelerating at high altitudes. Even if the engine output is insufficient due to a drop in atmospheric pressure, the gear position is maintained at a low gear position, and the required driving force is ensured. As a result, good acceleration performance can be obtained even when driving at high altitudes.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of the present invention, Figs. 2 to 11 show embodiments of the invention, Fig. 2 is a control system diagram, Fig. 3 is a flowchart showing the overall control operation, and Fig. 4 is a flowchart showing the overall control operation. The figure is a flowchart showing the throttle control operation, Fig. 5 is a characteristic diagram showing the characteristics of the basic value of the throttle opening with respect to the amount of accelerator depression used in this throttle control, and Fig. 6 is the characteristic used in calculating the throttle gain. 7 is a flowchart showing the shift control operation, FIG. 8 is a flowchart showing the shift-up determination operation in this shift control operation, and FIG. 9 is a shift pattern diagram showing the shift-up line used in this determination operation. , FIG. 10 is a flowchart showing a downshift determination operation in the above-mentioned shift control operation, and FIG. 11 is a shift pattern diagram showing a downshift line used in this determination operation. 5... Automatic transmission, 10... Speed change control means, speed change pattern changing means (controller), 14... High altitude driving detection means (atmospheric pressure sensor).

Claims (1)

[Claims] (1) A control device for an automatic transmission that is equipped with a shift control means that switches gears according to a predetermined shift pattern according to driving conditions, and that detects whether the vehicle is traveling on a high ground. Travel detection means; and a shift pattern change for changing the shift pattern to a high altitude pattern set in a direction to prevent upshifting to the highest gear when the detection means detects that the location is high. 1. A control device for an automatic transmission, comprising: means.