JP2800387B2 - Transmission control device for automatic transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling a shift in an automatic transmission for a vehicle.

2. Description of the Related Art It is a major issue how to reduce a shock at the time of shifting in an automatic transmission, and it is well known that various technologies have been conventionally developed. Shift shock is caused by a large change in output shaft torque due to fluctuations in the rotation of the rotating member including the engine before and after the shift, and therefore, generally, the inertial energy of the rotating member during shifting is reduced by clutches and brakes. Absorption by the frictional engagement means smoothes the change in the output shaft torque, thereby reducing shift shock. In addition, the amount of energy to be absorbed at the time of shifting is naturally reduced if the torque input to the automatic transmission is small.
Japanese Patent Application Laid-Open No. 62-184935 discloses a technique for reducing a shift shock by reducing an engine torque by, for example, delaying an ignition timing of an engine during a shift.

Problems to be Solved by the Invention By the way, in addition to reducing shift shocks, there is a demand for automatic transmissions that shift control is easy and that the number of shifts is small, so that shift shock is improved by reducing engine torque. If possible, it is effective to perform a shift control that can satisfy other demands including a factor that increases shift shock as a method of shifting in the automatic transmission. That is, for example, in an automatic transmission including a gear train having a plurality of types of engagement / disengagement combinations (engagement / release patterns) of the friction engagement means for setting a predetermined gear position, improvement of shift response and control are performed. In order to simplify the procedure, an engagement / disengagement pattern in which the number of times of switching of the friction engagement means is minimized is selected as an engagement / disengagement pattern for setting the gear position. It is effective to eliminate the influence on the shift shock due to the increase in the variable rotational speed of the rotating member by reducing the engine torque.

However, when the engine is not sufficiently warmed up or when an abnormality occurs in the engine torque reduction control mechanism, the engine torque cannot be reduced during gear shifting. If an engagement / disengagement pattern having a large variable rotation speed is selected, problems such as deterioration of shift shock and deterioration of durability of the friction engagement means occur.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a shift control method that can reduce shift shock even when engine torque reduction control cannot be performed.

Means for Solving the Problems In order to achieve the above object, the present invention provides a torque transmission path by switching a connection state of a plurality of rotating members in accordance with a combination of engagement and release of friction engagement means. There are a plurality of combinations in which the rotational speed of any of the rotating members is different from each other as a combination of engagement and disengagement of the friction engagement means for setting the speed by changing the speed and setting any speed. In a shift control device for an automatic transmission having a gear train and having a function of reducing engine torque at the time of shifting, means for detecting that engine torque reduction control cannot be performed, and that engine torque reduction control cannot be performed When the gear is shifted to the predetermined gear in a state where is detected, engagement of the friction engagement means for setting the gear is performed.
Means for selecting a combination having a small amount of change in the number of revolutions before and after the speed change of the rotating member as a combination of disengagement.

The automatic transmission targeted by the present invention has a plurality of types of combinations of engagement and disengagement of the friction engagement means for setting a predetermined gear position, and any one of them has a rotational speed of a rotating member. The second embodiment is different from the first embodiment in that control for reducing the engine torque during gear shifting can be performed. Therefore, since the shift shock can be reduced by reducing the engine torque, when the combination of engagement and disengagement of the friction engagement means is selected, even if the rotational speed of the rotating member increases, the number of shifts or It is possible to select a combination in which the number of switching of the friction engagement means is small. In such a case, when the engine torque and the reduction control cannot be performed, the combination of engagement / disengagement of the friction engagement means for setting the predetermined gear position is changed to one in which the rotating speed of the rotating member is small. As a result, the inertia torque at the time of shifting is reduced, so that shifting shock is improved, or deterioration of shifting shock is prevented.

EXAMPLE Next, an apparatus of the present invention will be described based on an example.

An example of control by the control device of the present invention is shown in a flowchart in FIG. 1. In the automatic transmission targeted by this method, a predetermined shift speed can be set by a plurality of types of engagement / disengagement patterns, and FIG. 2 is a block diagram showing one example. That is, the automatic transmission A is connected to the engine E via the torque converter T, and the transmission control device 10 receives the throttle opening θ, the vehicle speed V, the brake signal, the coolant temperature, the pattern select signal, and other signals. Then, based on such information, a gear position to be set and an engagement / disengagement pattern for setting the gear position are selected and a signal is output to the hydraulic control device C. Further, the shift control device 10 is an engine control device.
The engine control device 11 is connected to the engine control device 11 and outputs a shift signal from the speed change control device 10 to the engine control device 11 so that the engine control device 11 performs control for reducing the engine torque (for example, changing the ignition retard angle). When it is impossible, the signal is output to the shift control device 10.

The above-mentioned automatic transmission A is provided with a gear train having a plurality of types of engagement / disengagement patterns for setting a predetermined gear position. An example of the gear train is shown in FIG.

This gear train is configured by using three sets of single pinion type planetary gear mechanisms 1, 2, and 3, and includes a carrier 1C of the first planetary gear mechanism 1 and a ring gear 3R of the third planetary gear mechanism 3. Are connected so as to rotate integrally, and the ring gear 2R of the second planetary gear mechanism 2 and the carrier 3C of the third planetary gear mechanism 3 are connected so as to rotate integrally. The sun gear 1S of the first planetary gear mechanism 1 is connected to the carrier 2C of the second planetary gear mechanism 2 via the second clutch means K2, while the sun gear of the second planetary gear mechanism 2 is connected via the fourth clutch means K4. Connected to 2S and second
The carrier 2C of the planetary gear mechanism 2 is connected to the sun gear 3S of the third planetary gear mechanism 3 via fifth clutch means K5.

In addition, as a connection structure of the above-described components, a connection structure employed in a general automatic transmission such as a hollow shaft, a solid shaft, or an appropriate connecting drum can be employed.

The input shaft 4 is connected to an engine (not shown) via a power transmission means (not shown) such as a torque converter and a fluid coupling, and the input shaft 4 and the ring gear 1R of the first planetary gear mechanism 1 are connected to each other. In between, the first to selectively connect the two
A clutch means K1 is provided, and a third clutch means K3 for selectively connecting the input shaft 4 and the sun gear 1S of the first planetary gear mechanism 1 is provided between the input means 4 and the sun gear 1S. In practical use, there are restrictions on the arrangement of each component,
As a matter of course, an appropriate intermediate member such as a connecting drum can be interposed as a connecting member for each clutch means K1, K2, K3, K4, K5.

In addition, the third planetary gear mechanism 3 serves as brake means for preventing rotation of the rotating members in the planetary gear mechanisms 1, 2, and 3 described above.
The first brake means B1 for selectively blocking the rotation of the sun gear 3S, the second brake means B2 for selectively blocking the rotation of the carrier 2C of the second planetary gear mechanism 2, and the sun gear of the second planetary gear mechanism 2 Third brake means B3 for selectively preventing rotation of 2S and fourth brake means B4 for selectively preventing rotation of sun gear 1S of first planetary gear mechanism 1 are provided. In practical use, these brake means B
An appropriate connecting member is interposed between 1, B2, B3, B4 and each element to be fixed by these braking means B1, B2, B3, B4 or between a transmission case (hereinafter simply referred to as a case) 6. Obviously you can get it.

An output shaft 5 for transmitting rotation to a propeller shaft and a counter gear (not shown) is connected to a ring gear 2R of the second planetary gear mechanism 2 and a carrier 3C of the third planetary gear mechanism 3 connected to each other. ing.

In the automatic transmission having the configuration shown in FIG.
The first reverse speed is the main shift speed, which includes the second forward speed and the third forward speed.
So-called 2.2th, 2.5th, and 2.7th speeds are added between the first and second speeds, and so-called 3.2th and 3.5th speeds are added between the third and fourth speeds. In principle, it is possible to set 10 speeds and 1 reverse speed.
At other shift speeds except the 2.7th, 3.2th and 3.5th speeds, there are a plurality of combinations of engagement / disengagement of clutch means and brake means (so-called engagement / release patterns) for setting the shift speed. There is a set, and if this is shown as an operation table, it is as shown in Table 1. Table 2 shows the rotational speeds of the rotating members in each of the planetary gear mechanisms 1, 2, and 3 at each shift speed.
In Table 1, a circle indicates that the vehicle is engaged, a blank indicates that the vehicle is released, and an asterisk (*) indicates that the vehicle may be engaged. The gear ratio and the rotation state do not change even when released, such as the five-clutch means K5 and the first brake means B1, but if the clutch is released like the first brake means B1 in the pattern in the column b of the fourth speed, The gear ratio does not change, but the rotation state changes.
The fourth clutch means K4 and the third clutch
Includes those in which the gear ratio and the rotation state do not change even if the other * means such as the brake means B3 are engaged, even if released. In Tables 1 and 2, the second speed,
In the third, fourth, fifth, and reverse gears, the columns labeled a, b, c, etc. indicate the rotation of the planetary gear mechanism in the engagement / disengagement pattern for setting the gear. .. Indicate the engagement / disengagement pattern although the rotation speeds of the elements are different, and the symbols,... Represent the types of the engagement / release patterns although the rotation speeds of the rotation elements of the planetary gear mechanism are not different. Furthermore, the values shown in Table 2 are for each planetary gear mechanism 1, 2,
3 gear ratio (ratio of the number of teeth of sun gear and ring gear)
The ratio is shown when ρ1 = 0.450, ρ2 = 0.405, ρ3 = 0.405, and the input rotation speed is “1”.

In the automatic transmission A equipped with the gear train having the configuration shown in FIG. 3, it is possible to set the forward gear and the reverse gear as described above. , 1st, 2nd, 3rd, 4th
Speed and the fifth speed are set as the forward gears. Further, in the automatic transmission A, since the control for reducing the engine torque is performed simultaneously at the time of the shift, at the shift speed having a plurality of types of engagement / disengagement patterns, the fact that the number of shifts is small is primarily considered. Select the engagement / release pattern. As a specific example, in the normal case where the engine torque reduction control is performed, the second speed is set by the engagement / disengagement pattern in the column b shown in Table 1 and the third speed is set in the engagement / disengagement pattern in the column c. Set in the release pattern. Therefore, the shift from the second speed to the third speed is performed by engaging the second clutch means K2 or the third clutch means K3 and releasing the third brake means B3 or the fourth brake means B4. If the third speed is set by the engagement / disengagement pattern in the column c, the shift to the fourth speed can be achieved by engaging the fifth clutch means K5 and releasing the first brake means B1. Therefore, the speed from the second speed to the fourth speed via the third speed can be quickly increased. When switching from the engagement / disengagement pattern in the second speed column b to the engagement / disengagement pattern in the third speed column c, as shown in Table 2, the rotation speed of the sun gear 2S of the second planetary gear mechanism 2 is changed. Changes from "0.00" to "1.00", the rotation speed of the carrier 2C changes from "0.44" to "1.00", and these fluctuation rotation speeds set the third speed in the engagement / disengagement pattern in the b column. However, since the engine torque is reduced at the same time as the shift, the shift shock is not so large as to be problematic.

The above-described shift control from the second speed to the third speed is control performed simultaneously with control for reducing engine torque.
The engine torque reduction control cannot be executed when the engine is not sufficiently warmed up or when there is an abnormality in the signal system or mechanism. In this case, the shift control described below is performed in the present invention.

That is, taking an upshift from the second speed to the second speed as an example, the second shift in the flowchart of FIG.
When the shift from the third speed to the third speed is determined (step 1),
It is determined whether the engine torque control is prohibited (step 2). In a normal state, such as when the engine is sufficiently warmed up and there is no abnormality in the device, the determination result is “NO”, and the engagement / disengagement pattern (2-b pattern) in the column “b” for setting the second speed is set. The gear shift is executed by outputting a command signal for changing to the engagement / disengagement pattern (3-c pattern) in column c for setting the third speed (step 3). When the engine temperature is low or when there is some abnormality and the engine torque control is prohibited, the determination result of step 2 is “yes”, and in this case, the third speed is set in the pattern in the column b (3-b pattern ) To execute a shift to the third speed (step 4). Therefore, the rotation fluctuation of the sun gear 2S of the second planetary gear mechanism 2 accompanying the shift from the second speed to the third speed is "0" as is clear from Table 2, and the rotation of the carrier 2C is "0.35". From "0.51", and the variable rotation speed is "0.16". This is obviously smaller than the case where the third speed is set by the engagement / disengagement pattern in the column c. Therefore, even if the engine torque cannot be reduced, the inertia torque of the sun gear 2S and the carrier 2C becomes small. Shift shock does not worsen.

In this case, in order to avoid a so-called simultaneous shift of simultaneously switching to three or more friction engagement means when shifting to the fourth speed, after temporarily switching to the engagement / release pattern in column c,
The shift to the fourth speed is executed.

The control device according to the present invention can be applied to an automatic transmission having a plurality of types of engagement / disengagement patterns of friction engagement means for setting a predetermined gear position. FIG. 4 shows that the ring gear 2R of the second planetary gear mechanism 2 in the configuration shown in FIG. The shaft 5 is connected only to the carrier 3C of the third planetary gear mechanism 3, and the other configuration is the same as the configuration shown in FIG.

Table 3 shows the entire operation table, and Table 4 shows the number of rotations of each rotating member when the number of rotations of the input shaft 4 is "1". Note that the gear ratio of each planetary gear mechanism 1, 2, 3 is ρ1 =
0.450, ρ2 = 0.569, and ρ3 = 0.405.

Accordingly, even in the automatic transmission having the gear train shown in FIG. 4, the shift from the second speed to the second speed is performed in the normal state where the reduction control of the engine torque is possible, as shown in Table 3 at 2-b.
The shift is performed by switching from the pattern to the 3-c pattern. If the engine torque reduction control cannot be performed, the shift from the second speed to the third speed is performed by switching from the 2-b pattern to the 3-b pattern. I do. As a result, as can be seen from Table 4, the sun gear 2S of the second planetary gear mechanism 2
Is normally "1.00", but becomes "0.00" when low-speed engine torque control is not possible.
As for C, the fluctuation speed of “0.44” decreases to “0.16”,
Even if the engine torque cannot be reduced, the shift shock does not particularly deteriorate.

The present invention can be applied not only to the case of shifting from the second speed to the third speed shown in each of the above embodiments,
Of course, the same can be applied to the case where another shift is executed. In addition to the above-described automatic transmission having a gear train, the present invention is also applicable to a Japanese Patent Application No. Hei.
No. 5151, Japanese Patent Application No. 1-185152, Japanese Patent Application No. 1-186991, Japanese Patent Application No. 1-186999, Japanese Patent Application No. 1-205478, Japanese Patent Application No. 1-28
The present invention can be similarly applied to an automatic transmission having a configuration described in the specification and drawings such as No. 0957.

Effect of the Invention As described above, according to the method of the present invention, in a state where the engine torque cannot be reduced, the speed of the rotating member generated inside the automatic transmission due to the speed change can be reduced. Even if the input torque to the machine is large, the inertia torque of the rotating member can be reduced, and shift shock can be reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining an example of control by the control device of the present invention, FIG. 2 is a block diagram showing an example of an automatic transmission to which the method is applied, and FIG. 3 is a skeleton showing an example of the gear train. FIG. 4 is a skeleton diagram showing another gear train. 1, 2, 3 ... planetary gear mechanism, 4 ... input shaft, 5 ... output shaft, 10 ... shift control device, 11 ... engine control device, A
... automatic transmission, C ... hydraulic control device, E ... engine.

Claims (1)

(57) [Claims] 1. A gear transmission stage is set by changing a connection state of a plurality of rotating members in accordance with a combination of engagement and disengagement of frictional engagement means to change a torque transmission path. Engagement of friction engagement means for setting
A shift control device for an automatic transmission, comprising: a gear train having a plurality of types of combinations in which the rotational speeds of any of the rotating members are different from each other as a combination of disengagement; and having a function of reducing engine torque during shifting. Means for detecting that the reduction control of the engine cannot be performed, and friction engagement means for setting the gear when the gear is shifted to the predetermined gear in a state in which the control for reducing the engine torque cannot be performed. Means for selecting a combination having a small amount of change in the number of revolutions of the rotating member before and after shifting as a combination of engagement and disengagement.