JP2926083B2 - Shift control device for automatic transmission for vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission, and more particularly to a shift control device for an automatic transmission for a vehicle which may execute a clutch-to-clutch shift.

[0002]

BACKGROUND OF THE INVENTION In order to achieve a particular shift in an automatic transmission, it is often necessary to simultaneously engage and disengage two frictional engagement devices (a so-called clutch-to-clutch shift). In this case, if the synchronization and disengagement of the respective friction engagement devices are not properly synchronized, the gear train of the automatic transmission instantaneously becomes rigid or neutral, and the output shaft torque is reduced. There is a possibility of a sudden descent or an engine blow-up.

For this reason, when such control is conventionally performed, a one-way clutch having a function substantially equivalent to the function of one of the friction engagement devices is provided to prevent such a problem from occurring. ing.

However, the method of synchronizing the respective friction engagement devices by using the one-way clutch as described above has problems such as an increase in weight and an occupation of a housing space due to the provision of the one-way clutch. In addition, there is also a problem that the cost is increased accordingly. Therefore, for example, a clutch-to-clutch shift may be intentionally executed in a truck or the like (for example, General Motors, Allison type automatic transmission 540 in the United States).

[0005]

However, the automatic transmission for executing the clutch-to-clutch shift naturally has a problem that the shift shock increases. This is because the timing control of each clutch is extremely difficult as described above. For this reason, using an orifice control valve or a shift timing valve, for example, the oil pressure of the friction engagement device on the drain side and the oil pressure of the friction engagement device on the supply side are skillfully controlled to adjust the timing of the two friction engagement devices. Attempts to synchronize may be made,
It is not possible to cope with variations in engine output, etc., and the actual situation is that a considerable amount of shock has occurred.

The present invention has been made in view of such a conventional problem, and in consideration of practicality, a predetermined gear-to-clutch shift is executed only when it is really required. It is an object of the present invention to minimize the need to execute clutch-to-clutch shifting in a range where there is no problem while securing the gear ratio of the ratio, thereby minimizing the occurrence of shift shock while maintaining low cost. .

[0007]

SUMMARY OF THE INVENTION As shown in FIG. 1, the present invention relates to a shift control device for an automatic transmission for a vehicle which can execute at least one clutch-to-clutch shift. And when the accelerator opening is smaller than a predetermined value, the shift is executed using a gear sequence higher than the speed at which at least one clutch-to-clutch shift is avoided, and the accelerator opening is set to a predetermined value. When the value is equal to or more than the value, the above-mentioned problem is solved by providing a means for executing a shift using a gear train including a gear achieved by executing the clutch-to-clutch shift. .

[0008]

In the present invention, the accelerator opening (a parameter corresponding to the accelerator opening, for example, including the concept of the throttle opening) is detected, and when the accelerator opening is smaller than a predetermined value, clutch-to-clutch shifting is avoided. The shift is executed by using a gear train on a higher speed side than the gear speed to be changed, and when the accelerator opening is equal to or more than a predetermined value, a gear train including a gear speed achieved by executing a clutch-to-clutch shift is set. I use it to shift gears.

For example, when the shift between the first speed and the second speed is a clutch-to-clutch shift, the clutch-to-clutch shift is avoided during a so-called normal running in which the accelerator opening is equal to or less than a predetermined value. The shift is executed by using the gear stage, that is, the gear stage higher than the second speed stage. That is, the first
No gear is used. As a result, since the clutch-to-clutch shift itself does not occur, a large shift shock naturally does not occur.

On the other hand, when the accelerator opening is greater than a predetermined value,
For example, when the driver desires a sudden start, or when the driver has to start from a steep ascending road with a load, the gear position achieved by executing the clutch-to-clutch shift (in the above example). In this case, the shift is executed by using the gear train including the first speed. In such a case, since the driver needs a large driving force, it is important to secure a predetermined gear ratio, and it is understood that some shift shock is allowed. The "predetermined value" may be different between the upshift side and the downshift side.

Since the present invention has such an effect,
As a result, it is possible to rationally balance the securing of the predetermined gear ratio and the avoidance of the shift shock due to the clutch-to-clutch shift.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is an overall schematic view of an integrated control device for an automatic transmission and an engine to which the present invention is applied.

The engine 1 has an injection valve 19 by an engine control computer 7.
And the ignition timing at the distributor 20 are controlled, and an engine output corresponding to the accelerator opening (operating amount) of the accelerator pedal 22 and the engine speed is obtained.

That is, a throttle valve 26 that opens and closes in conjunction with the movement of the accelerator pedal 22 is disposed in the intake pipe 24 of the engine 1 so that the accelerator operation amount and the engine output correspond in a predetermined relationship. Has become.

The automatic transmission 2 is controlled by the automatic transmission control computer 8 to operate the solenoid valves S1 to S1 of the hydraulic control device 3.
S4 is controlled, and as a result of the change of the oil passage in the hydraulic control device 3, the engagement state of each friction engagement device is selectively changed,
The shift speed corresponding to the vehicle speed and the accelerator opening can be obtained.

The engine control computer 7 includes an engine rotation speed detected by an engine rotation sensor 9, an intake air amount detected by an intake air amount sensor 10, and an intake air temperature sensor 1.
1, the accelerator opening by the accelerator opening sensor 12, the vehicle speed by the vehicle speed sensor 13, the engine water temperature by the engine water temperature sensor 14, the brake switch 1
5 are input.

The engine control computer 7 determines the fuel injection amount and the ignition timing based on these signals.

On the other hand, the automatic transmission control computer 8 includes the accelerator opening sensor 12 and the vehicle speed sensor 1.
3. In addition to the signals from the engine water temperature sensor 14, the brake switch 15, etc., the position of the shift lever by the shift position sensor 16, the pattern select switch 17
A driving selection pattern such as fuel-conservation-oriented traveling or power-performance-oriented traveling, and a signal for permitting a shift to overdrive by the overdrive switch 18 are input to obtain a speed corresponding to the vehicle speed and the accelerator opening. The solenoid valves S1 to S4 are ON-OFF controlled.

FIG. 3 is a skeleton diagram showing a specific example of the automatic transmission 2 described above. The automatic transmission 2 includes a torque converter 111, an auxiliary transmission unit 112, and a main transmission unit 113.

The torque converter 111 has a lock-up clutch 124. The lock-up clutch 124 is provided between a front cover 127 integrated with the pump impeller 126 and a member (hub) 129 integrally mounted with the turbine runner 128.

A crankshaft (not shown) of the engine 1 is connected to a front cover 127. The input shaft 130 connected to the turbine runner 128 is connected to the overdrive planetary gear mechanism 13
And one carrier 132.

In the planetary gear mechanism 131, a clutch C0 and a one-way clutch F0 are provided between the carrier 132 and the sun gear 133. The one-way clutch F0 is engaged when the sun gear 133 rotates forward relative to the carrier 132 (rotation in the rotation direction of the input shaft 130).

On the other hand, a brake B0 for selectively stopping the rotation of the sun gear 133 is provided. Further, a ring gear 134 which is an output element of the auxiliary transmission section 112 is connected to an intermediate shaft 135 which is an input element of the main transmission section 113.

When the clutch C0 or the one-way clutch F0 is engaged, the auxiliary transmission portion 112
Since the whole of the shaft 31 rotates integrally, the intermediate shaft 135 is rotated.
Rotate at the same speed as the input shaft 130. When the brake B0 is engaged and the rotation of the sun gear 133 is stopped, the ring gear 134 is rotated forward with the speed increased with respect to the input shaft 130. That is, the subtransmission unit 112 can set high-low two-stage switching.

The main transmission section 113 has three sets of planetary gear mechanisms 140, 150 and 160, and these gear mechanisms 140, 150 and 160 are connected as follows.

That is, the sun gear 141 of the first planetary gear mechanism 140 and the sun gear 151 of the second planetary gear mechanism 150 are integrally connected to each other, and the ring gear 143 of the first planetary gear mechanism 140 and the sun gear 151 of the second planetary gear mechanism 150 are connected. Carrier 1
52 and the carrier 162 of the third planetary gear mechanism 160 are connected. The output shaft 170 is connected to the carrier 162 of the third planetary gear mechanism 160. Further, a ring gear 153 of the second planetary gear mechanism 150 is connected to a sun gear 161 of the third planetary gear mechanism 160.

In the gear train of the main transmission portion 113, one reverse speed and four forward speeds can be set, and a clutch and a brake for that purpose are provided as follows.

That is, the ring gear 153 of the second planetary gear mechanism 150 and the sun gear 161 of the third planetary gear mechanism 160
A clutch C1 is provided between the intermediate shaft 135 and the sun gear 141 of the first planetary gear mechanism 140 and a sun gear 151 of the second planetary gear mechanism 150.

A brake B1 for stopping rotation of the sun gears 141 and 151 of the first planetary gear mechanism 140 and the second planetary gear mechanism 150 is provided. In addition, these sun gears 1
A one-way clutch F1 and a brake B2 are arranged in series between 41, 151 and the casing 171.

Carrier 142 of first planetary gear mechanism 140
A brake B3 is provided between the motor and the casing 171. A brake B4 and a one-way clutch F2 are provided in series between the carrier 142 and the casing. Further, the ring gear 163 of the third planetary gear mechanism 160
A brake B5 is arranged as an element for stopping the rotation of the brake B5.

FIG. 4 shows an engagement operation table of each clutch and brake for setting the gear position in the automatic transmission 2 described above. In FIG. 4, 印 indicates the engaged state, () indicates the engaged state during engine braking, and ブ レ ー キ indicates the engaged state but no torque transmission.

In this embodiment, the shift between the first speed and the second speed is a clutch-to-clutch shift.

The shift control device shown in FIG. 2 has a predetermined shift map as a storage content of the automatic transmission control computer 8, and among them, a shift map used in the D range is shown in FIG. Such a shift map is provided.

As is apparent from FIG. 5, this shift map shows that there is no room for using the first speed stage when the accelerator opening is equal to or less than θ1 in the case of an upshift. Also, the clutch-to-clutch upshift from the first gear to the second gear does not occur. According to the shift map, the vehicle starts from the second speed stage when the vehicle starts normally (the accelerator opening is θ1 or less).

On the other hand, in the case of a downshift, the first speed is established only when the accelerator opening is equal to or larger than θ2. That is, when the accelerator opening is equal to or smaller than θ2, the first speed is not used, so there is no room for a downshift from the second speed, which is a clutch-to-clutch shift, to the first speed.

As a result, if the accelerator pedal is slightly depressed in so-called normal running, a downshift of 2 → 1 does not occur, and the second speed is maintained, and clutch-to-clutch shift is prevented. You. On the other hand, a downshift of 2 → 1 occurs only when the accelerator pedal is depressed greatly, and a downshift to the first speed stage ensures a predetermined gear ratio.

In this automatic transmission, only a shift between the first speed and the second speed is a clutch-to-clutch shift, and a one-way clutch is interposed in other shifts, so that a smooth shift can be achieved. Is to be executed.

However, in the present invention, it is not always required that the one-way clutch be interposed in all the shifts at the second speed and higher.

As is apparent from FIG. 4, in this automatic transmission, the reverse (reverse) is performed by the clutch C2 and the brake B3.
Is achieved by the combination of This is because the torque distribution of the brake B3 at the time of reverse can be small, and the brake can be downsized. Of course, if space permits, reverse can also be achieved with a combination of clutches C2 and B5. However, the problem that the output shaft torque becomes very large remains. In order to change the speed between the first speed and the second speed to a one-way clutch-to-clutch, a one-way clutch is provided between the ring gear 163 of the third planetary gear mechanism 160 and the casing 171 in parallel with the brake B5. In this case, it is impossible to achieve the reverse gear by the combination of the clutch C2 and the brake B3. Therefore, this configuration can be said to be an ancillary effect of shifting the speed between the first speed and the second speed to the clutch-to-clutch speed. Since the reverse stage having a relatively small output shaft torque can be achieved in this manner, a so-called garage shift such as raising the sub-transmission portion 112 at the time of reverse as in the prior art, or cut control of engine output, and measures against failure And so on can be omitted. Also, as shown in FIG.
In the case of starting at the first gear, when the oil temperature of the oil (ATF) in the transmission is low, when the engine is warmed up,
When it is difficult to control the clutch-to-clutch shift, for example, when a predetermined sensor has failed, the start by the first gear is prohibited (stopped) even when the accelerator opening is equal to or more than a predetermined value.
You may make it start by 2nd gear.

In this embodiment, the shift between the first speed and the second speed is a clutch-to-clutch shift. At this time, the clutch C0 is temporarily drained and the one-way clutch F0 is once engaged. A technique of utilizing the engagement of the one-way clutch F0 at the end of shifting and shifting (see Japanese Patent Publication No.
35773) can also be employed. in this case,
Since this technology tends not to provide a sufficient effect at a low vehicle speed and a low opening, in this regard, the technology and the technology of the present invention are combined at a low vehicle speed and a low opening with a clutch-to-clutch. It is very effective and rational in the sense that shifting is avoided.

When the present embodiment is executed, it is more preferable to add a vehicle speed failure determination routine. This is to prevent a shock from being generated by downshifting to the first gear and applying a sudden engine brake even if the vehicle speed sensor fails while the accelerator pedal is depressed. Specifically, it is detected that the vehicle speed sensor has failed by any method, and when it is determined that the vehicle speed sensor has failed, the downshift to the first speed is prohibited regardless of the accelerator opening. What is necessary is just to make a flow.

[0043]

As described above, according to the present invention,
It is possible to obtain an excellent effect that a predetermined gear ratio can be secured by executing the clutch-to-clutch shift, which tends to cause a large shift shock, when most of the travel is performed, while avoiding the shift during most of the travel. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the present invention.

FIG. 2 is a schematic block diagram showing an embodiment of the present invention.

FIG. 3 is a skeleton diagram showing a gear train of the apparatus of the embodiment.

FIG. 4 is a diagram showing an operation state of the friction engagement device of the gear train.

FIG. 5 is a shift map in which the vehicle speed-accelerator opening is used as a parameter, which is employed in the above-described embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Automatic transmission, 7 ... Engine control computer, 8 ... Automatic transmission control computer, 12 ... Accelerator opening sensor, 13 ... Vehicle speed sensor.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Hojo 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (72) Inventor Masahiro Hayabuchi 10 Takane Fujii Town, Anjo City, Aichi Prefecture Aisin AW Inside (72) Inventor Masahiko Ando 10 Takane, Fujii-machi, Anjo, Aichi Prefecture Inside Aisin AW Co., Ltd. (72) Inventor Kazuma Tsukamoto 10 Takane, Fujii-machi, Anjo, Aichi Aisin Ai JP-A-2-225874 (JP, A) JP-A-3-134362 (JP, A) JP-A-3-61759 (JP, A) JP-A-62-283534 (JP) JP-A-2-261958 (JP, A) JP-A-2-292568 (JP, A) JP-A-2-124357 (JP, U) (58) Fields studied (Int. Cl. ⁶ , DB Name) F16 H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (1)

(57) [Claims] A shift control device for an automatic transmission for a vehicle which may execute at least one clutch-to-clutch shift, means for detecting an accelerator opening, and at least when the accelerator opening is smaller than a predetermined value. Shifting is performed using a shift stage higher than the shift stage where one clutch-to-clutch shift is avoided, and when the accelerator opening is greater than or equal to a predetermined value, the shift is achieved by executing the clutch-to-clutch shift. And means for performing a shift using a gear train including a gear stage of the vehicle.