JPS60237257A - Control device for automatic speed change gear - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for an automatic transmission, and more particularly to control when changing gears of an auxiliary transmission.

BACKGROUND ART In order to improve driving performance, there is an automatic transmission that is equipped with an auxiliary transmission that can be manually switched between a high speed gear and a low speed gear. In such automatic transmissions, the auxiliary transmission is located on the output side of the main transmission that can automatically change gears, in order to reduce the number of changes required for automatic transmissions without an auxiliary transmission, which is advantageous in terms of manufacturing. It is often set up in

In this case, even though the serial shooter had switched the operating position of the auxiliary transmission from a high gear position (high gear) to a low gear position (low gear) in order to increase the drive torque, the main gear shift due to this switching The main transmission may be upshifted due to the increase in the machine output shaft rotational speed, and the driving force intended by the driver may not be obtained. Conversely, even though the driver has switched the operating position of the auxiliary transmission from the low gear position to the high gear position, the main transmission is unable to operate due to the decrease in the output shaft rotational speed of the main transmission caused by the switching. If the engine is downshifted, the engine rotational speed may not decrease, resulting in discomfort and shift shock. In particular, even when an auxiliary transmission is added, the vehicle speed sensor detects the rotational speed of the output shaft of the main transmission, and therefore the rotational speed of the input shaft of the auxiliary transmission. Since the rotational speed of the output shaft of the main transmission significantly increases and decreases by switching to a high speed gear, the main transmission is likely to shift in a direction opposite to the driver's intention.

In the transmission disclosed in Japanese Patent Publication No. 56-73251, a manual transmission and an automatic transmission are connected in series, and when the manual transmission is in a low gear, that is, when the torque fluctuation of the engine is large, Automatic transmissions are prohibited from shifting to avoid excessive shift shock. Also, special public service 1986-1973
In the transmission disclosed in Publication No. 252, a manual transmission and an automatic transmission are similarly connected in series, and when the engine speed is above a predetermined value, downshifting of the automatic transmission is prohibited to prevent engine overrun. It's being defended.

However, neither publication mentions special control of the gear position of the automatic transmission when the gear position of the manual transmission is manually changed.

OBJECTS OF THE INVENTION An object of the present invention is to provide an automatic transmission in which a sub-transmission capable of manually changing gears is provided on the output side of the main transmission. An object of the present invention is to provide a control device that prevents inappropriate gear shifting.

Means for Accomplishing the Object In order to achieve the object, the present invention provides a main transmission having a plurality of gears and capable of automatically changing gears at least in relation to vehicle speed, and a main transmission. In a control device for an automatic transmission equipped with an auxiliary transmission connected to the output side and capable of switching between a high gear and a low gear by manual operation, the operation position for determining the gear of the auxiliary transmission is from the high gear position. A limiting means is provided for limiting upshifting of the main transmission when the gear is switched to a low gear position.

Further, according to the present invention, there is provided a main transmission having a plurality of gears and capable of automatically switching gears at least in relation to the vehicle speed, and a main transmission connected to the output side of the main transmission and switching between a high gear and a low gear. In a control device for an automatic transmission equipped with an auxiliary transmission that can be changed manually, when the operating position that determines the gear position of the auxiliary transmission changes from a low gear position to a high gear position, the main transmission It is equipped with a restriction means for restricting download software.

Functions and Effects of the Invention When the driver switches the operating position from the high gear position to the low gear position, the auxiliary transmission changes from the high gear to the low gear, and as a result, the vehicle speed detected by the vehicle speed sensor increases, but there is a limit. Since the means restricts upshifting of the main transmission despite the increase in vehicle speed, it is possible to prevent the main transmission from shifting gears contrary to the driver's intention and to obtain an appropriate driving torque. Wear.

Also, when the driver switches the operating position from the low gear position to the high gear position, the sub-transmission changes from the low gear to the high gear.
As a result, the vehicle speed detected by the vehicle speed sensor decreases, but the limiting means restricts downshifting of the main transmission despite the decrease in vehicle speed, causing a shift in the main transmission that is contrary to the driver's intention. This prevents the discomfort of an increase in engine rotational speed and avoids the need to change gears.

If the vehicle speed sensor is on the output shaft of the sub-transmission,
Although it is necessary to provide a separate shift pattern for H, even in such a case, if the shift pattern after manual shifting is adopted at the same time as the H-)L or L-)H operation, a jump shift of two or more gears will occur. do.

Preferably, the limiting means maintains the gear position of the main transmission immediately before the operation position is changed, or prohibits shifting to a gear position that is two or more gears away from the current gear position. When upshifting to the high speed side by two or more gears is prevented and upshifting to only one gear is allowed, it is possible to prevent engine overrun and appropriately suppress a decrease in drive torque.

The limiting means for limiting upshifts of the main transmission may maintain the main transmission at the lowest gear position at which engine overrun can be avoided.

Example The present invention will be explained with reference to the embodiments shown in the drawings.

Figure 1 shows an automatic transmission and its control device.
Engine 10. fluid torque converter 12, main transmission 14,
and an auxiliary transmission fi16 are provided in series in the power transmission path of the engine. A lock-up clutch 18 is provided in parallel with the fluid torque converter 12 and is connected to the main transmission 14.
has first to fourth gears that are automatically switched depending on the vehicle speed and throttle opening, etc., and the sub-transmission 1
6 has a high speed gear and a low gear that can be switched by manual operation. The shift position sensor 20 is set to D (drive), N (neutral), and R selected by the driver.
Detects shift positions such as (reverse) range,
The L/H position sensor 22 detects L (low gear) and H (high gear) of the sub-transmission 16 selected by the driver, the throttle opening 24 detects the intake throttle opening, and the pattern select switch 26 detects the intake throttle opening. detects the driving pattern such as economy (economical driving) and power (acceleration driving) selected by the driver, the water temperature sensor 28 detects the engine cooling water temperature, the brake switch 30 detects depression of the foot brake, Vehicle speed sensor 32 detects the rotational speed of output shaft 34 of main transmission 14, and therefore the vehicle speed. CPU
36 is a solenoid valve 42, 44 of a main transmission control hydraulic circuit 38 and an auxiliary transmission control hydraulic circuit 4° based on input signals from these sensors, switches, etc.
The solenoid valves 42 and 44 that control the lock-up clutches 46 and 48 are used to control the first to fourth speeds of the main transmission 14, and the solenoid valves 46
8, and the solenoid valve 48 is used to control the high speed gear and the low speed gear of the auxiliary transmission 16.

FIG. 2 is a flowchart of a shift control routine when the operating position of the auxiliary transmission 16 is changed from H (high gear: high gear) to H (low gear: fI gear). As soon as the ignition switch is turned on (step 60), a flag F indicating a change in H-+L is assigned 0 as an initial value (step 62).

In the main routine of step 64, the gear position of the main transmission 14 is subtracted as the commanded gear position based on the intake throttle opening θ and the vehicle speed V.

1(-+ If there is no change in L, it is determined to be F-0 in step 66, and H- is determined in step 70.
) Since L is determined to be NO, step 86 is executed without correcting the indicated gear position calculated in step 64, and even though the main transmission 14 is set to that gear position, if there is a change in H-+L. , before the change from H→L, the indicated gear position calculated in step 64 is substituted into Ml (
Step 68) and flag F is set (Step 72).
), the commanded gear position is calculated again in the main routine of step 64.

1 (→1. The indicated gear position calculated after the change is assigned to M2 (step 74), and the indicated gear position M2 after the H→L change is
is less than or equal to the designated gear position before the H-+L change (M2≦M+ in step 76), that is, the main transmission 14
If a downshift instruction is given, change the indicated gear to M.
2 (step 82), reset the flag F (step 84), and execute step 86. However, if an instruction to upshift the main transmission 14 is issued even after the H→■− change (M2>old in step 76), the commanded gear is changed to Ml, which is the gear before the H→L change. Step 86 is executed. Indicated gear =
M1 is held until the upshift permission condition is satisfied (YES in step 8o). The upshift permission conditions include, for example, that the driver has switched the operation position of the sub-transmission 16 from ■ to H, that the vehicle speed is OK m/h, and that the intake throttle opening has suddenly decreased. .

FIG. 3 shows a partially modified version of the routine shown in FIG.

If there is a change of H-+L, the main shift P is two or more gears higher than the gear before the change from H to L! 14 upshifts are prohibited. Since upshifting of only one gear is allowed, engine overrun can be appropriately suppressed. That is, M2 and old +1 are compared in step 76b, and if M2>old +1, M]+] is set as the designated gear in step 78b, but if M2≦old+1, M2 is set as the designated gear in step 82. Assign to .

FIG. 4 shows another embodiment of the shift routine when H4L changes. When flag F is set in step 72c, the process proceeds to step 66 without calculating the designated gear position again in step 64. ■When there is a change from 1 to L, upshifting of the main transmission is prohibited until the upshift permission condition of 4 is satisfied (YES at step 80), but when engine overrun is unavoidable. allows upshifts to the lowest gear that avoids overrun.

That is, the rotational speed Nou of the output shaft 34 of the main transmission 14
t (step 94), and calculate the coefficient Ki related to the gear ratio corresponding to the indicated gear (step 92.96).
, calculate the engine rotational speed Ne occurring at the indicated gear (step 98), and if Ne is greater than or equal to the overrun rotational speed Nc (in step 100, Ne>NC).
), the commanded gear is set to a higher speed by one gear (step 102), and the lowest gear where Ne<Nc is set.

The gear position corresponding to I thus determined is set as the designated gear position (step 104), and the routine of step 86 is executed.

FIG. 5 shows the operating position of the sub-transmission I6 at 1. 12 is a flowchart of a shift control routine when switching from to II. Explanation of steps common to the routine of FIG. 2 will be omitted, and important points will be described. Note that the flag F is L.
-+ Used to indicate that there has been a change in H.

If there is a change in L-+H (YE in step 70d)
S), flag F is set (step 72), then L
-+ l (The indicated gear position after the change is assigned to M2 (
Step 74). The indicated gear M2 after changing from L to H is L-
+1 (if it is equal to or higher than the commanded gear position before the change (M2≧old in step 76d), that is, if an instruction to upshift the main transmission 14 has been issued, the commanded gear position is set to M2 (step 82) , if the command to downshift the main transmission 14 is issued even after the change in L-+H (M2<old in step 76d), the commanded gear is set to the old gear before the change from I4 to 11. The indicated gear position = M1 is held until the downshift permission condition is met (YES in step 80d). The intake throttle valve is fully opened, and a predetermined time has elapsed after the change from L to H.

FIG. 6 shows a partially modified version of the routine shown in FIG.

If there is a change in L - + l, the main transmission 14 is prohibited from downshifting to a lower gear by two or more gears than the gear before the change from L to H. In other words, in step 76e, M2 and old -1, and if t12≧M1-1, the instructed gear stage is set to M2 in step 82;
If <Ml~1, Ml-1 is substituted for the designated gear position in step 78e.

Although the present invention has been described with reference to embodiments, it will be obvious to those skilled in the art that various modifications can be made without departing from the spirit of the invention.

[Brief explanation of drawings]

Figure 1 is an overall diagram of an automatic transmission and its control device. Figures 2, 3, and 4 show the operating position of the auxiliary transmission in H.
Flowcharts of various shift control routines for the main transmission when switching from L to L; FIGS. 5 and 6 show various shift control routines for the main transmission when switching the operating position of the auxiliary transmission from L to H It is a flowchart of a routine. 14... Main transmission, +6... Sub-transmission, 22...
L-H position sensor, 32...Vehicle speed sensor, 36
...cpu 0

Claims (1)

[Scope of Claims] 1. A main transmission having a plurality of gears and capable of automatically switching gears at least in relation to the vehicle speed, and a main transmission connected to the output side of the main transmission and switching between a high gear and a low gear. In a control device for an automatic transmission equipped with an auxiliary transmission that can be changed manually, when the operating position that determines the gear position of the auxiliary transmission changes from a high gear position to a low gear position, the main transmission 1. A control device for an automatic transmission, comprising: limiting means for limiting upshifts. 2. The control device according to claim 1, wherein the limiting means is a means for holding the gear position of the main transmission immediately before the operation position is changed from the high gear position to the low gear position. 3. The restricting means is a means for prohibiting upshifting to a gear position two or more gears higher than the gear position of the main transmission immediately before the operation position changes from the high gear position to the low gear position. A control device according to claim 1. 4. The control device according to claim 1, wherein the limiting means maintains the main transmission at the lowest gear position at which engine overrun can be avoided. 5. A main transmission that has a plurality of gears and can automatically change gears at least in relation to the vehicle speed, and a main transmission that is connected to the output side of the main transmission and that can be switched between high and low gears by manual operation. In a control device for an automatic transmission equipped with an auxiliary transmission, the downshift of the main transmission is restricted when the operating position that determines the gear position of the auxiliary transmission changes from a low gear position to a high gear position. A control device for an automatic transmission, comprising: limiting means. 6. The control device according to claim 5, wherein the limiting means is means for holding the gear position of the main transmission immediately before the operation position is changed from the low gear position to the high gear position. 7. The limiting means is a means for prohibiting a downshift to a gear position two or more gears lower than the gear position of the main transmission immediately before the operation position is changed from the low gear position to the high gear position. A control device according to claim 5.