JPH07111217B2 - Shift control device for automatic transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to shift control in a vehicle automatic transmission.

[0002]

2. Description of the Related Art An automatic transmission has a plurality of power transmission gear trains between input and output shafts, and these gear trains are selectively switched by engagement control of engagement elements such as clutches and brakes to shift gears. The engagement control of this engagement element is automatically performed by the hydraulic actuator, and the automatic shift is performed. In such a gear shift, the engagement element (previous stage engagement element) that has been engaged until then is released, and the engagement element for the shift stage (next stage engagement element) to be set by the shift is engaged. Let

In this case, if the disengagement timing of the preceding stage engagement element is too early or the engagement timing of the next stage engagement element is delayed, none of the engagement elements will be engaged and the engine The problem arises that the air blows up. Further, if the release timing of the preceding stage engagement element is delayed or the engagement timing of the next stage engagement element is too early, both engagement elements will be in a meshed state and a large deceleration shock will occur. Therefore, various control means have been conventionally proposed in order to prevent such a problem by adjusting the release timing of the front stage engagement element and the engagement timing of the next stage engagement element.

For example, an orifice is provided in the oil passage for supplying the operating oil pressure to the engaging element to adjust the engaging timing, or the difference between the operating oil pressure of the preceding engaging element and the operating oil pressure of the next engaging element is set. It is well known in the art to adjust the engagement timing by using a valve that operates in response to the difference and forcibly reduces the hydraulic pressure of the preceding stage engagement element when the difference becomes equal to or larger than a predetermined value. However, this timing adjustment is performed by appropriately setting the orifice diameter, the valve pressure receiving area, the spring load, and the like, and there is a problem that the timing often shifts due to manufacturing errors (variations) and changes over time. .

From the above, Japanese Patent Laid-Open No. 62-246
Japanese Patent No. 653 discloses controlling the engagement force of the preceding stage engagement element so that the rotation of the input shaft of the transmission coincides with a target rotation speed that is higher by a predetermined value than the input shaft rotation speed immediately before the gear shift command, at the time of gear shifting. At the same time, in parallel with this, the engagement control of the next-stage engagement element is also performed, and when the effective gear shift is started by the engagement of the next-stage engagement element, the rate of change of the rotation of the input shaft matches the target rate of change. Thus, there is disclosed a shift control device that controls the engagement force of the next-stage engagement element.

Further, US Pat. 4,938,10
2, the same No. 4,947,329 and the same No. 4, 9
51, 200 discloses a shift control method for performing engagement control of engagement elements based on engine rotation, output rotation of a torque converter, and the like. If this gear shift control device is used, engagement control of the engagement elements is performed based on engine rotation, transmission input shaft rotation, and the like, so the above-described variations in manufacturing, variations over time, and the like pose problems. There are few things.

Further, in Japanese Unexamined Patent Publication No. 1-261559, the shift operation period is divided into a torque phase period and an inertia phase period, and feedback control and feedforward control are performed respectively to shift from the torque phase to the inertia phase. Discloses a shift control method of controlling based on a change in output torque. JP-A-2-
In the 3770 publication, in the downshift from the 3rd speed to the 2nd speed, the engaging torque of the engaging means for the 3rd speed is gradually reduced, and when the slip of the engaging means exceeds the first reference value, the hydraulic pressure is changed. A shift control method is disclosed in which the gear is held as it is and the downshift is performed by engaging the engagement means when the slip of the second speed engagement means falls below a reference value.

[0008]

In such a control device and method, it is determined whether or not the effective gear shift is started by the engagement of the next stage engagement element so that the gear shift type can be appropriately controlled. Whether or not the input shaft rotational speed, which was controlled to reach the target rotational speed by the engagement control of the preceding stage engagement element, has decreased to the input shaft rotational speed immediately before the gear shift command is detected. I am supposed to do it. Theoretically, if the input shaft rotation speed reaches the input shaft rotation speed immediately before the gear shift command, the previous stage engagement element is released and the engagement of the next stage engagement element is started to allow smooth gear shifting. You can

However, in the actual control device, it is inevitable that a time delay will occur until the hydraulic pressure actually changes from the control command and the engagement element operates, and as described above, the input shaft rotation speed changes. If the control shifts to the next control when the input shaft rotational speed immediately before the command is reduced, there is a problem that the next control (that is, the release control of the preceding stage engagement element and the engagement control of the next stage engagement element) is delayed. . Therefore, in the case of the shift control disclosed in the above publication, the release feeling of the front stage engagement element may be delayed, the engagement of the next stage engagement element may be abruptly performed, and the shift feeling may be impaired. There's a problem.

Further, in the gear shift control device of the above publication, when the gear shift command is output, the pre-stage control is performed so that the rotation of the input shaft coincides with the target rotation speed which is higher than the input shaft rotation speed immediately before the gear shift command by a predetermined value. The engagement force of the coupling element is controlled, and the engagement force control of the next-stage engagement element is performed from the time when effective gear shift is started by the engagement of the next-stage engagement element. Such shift control is suitable for a shift-up shift in a power-on state (that is, a state where the accelerator pedal is depressed), but a kick-down shift (that is, a shift-down shift in a para-on state). In the case of, there is a problem that it cannot be used.

In the case of a shift-up shift, the input shaft speed after the shift is reduced as long as the vehicle speed remains the same. Therefore, if the front-stage engaging element is released during the shift, the power-on state is established, and therefore the input driven by the engine is changed. The shaft rotation tries to rise. If the input shaft rotation increases, it is separated from the input shaft rotation after the gear shift. Therefore, it is necessary to control the input shaft rotation to the predetermined rotation by the engagement control of the preceding stage engagement element as described above. However, in the case of kickdown gear shifting, the input shaft rotation after gear shifting increases as long as the vehicle speed remains the same. Therefore, when shifting, the input shaft speed is not maintained at the speed immediately before shifting, but is increased as it is, and when the input shaft rotation increases to the speed corresponding to the gear ratio of the next stage, the next stage engagement element is set. It is most desirable to perform engagement control, which allows smooth and delay-free shifting.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an automatic vehicular vehicle capable of smoothly performing a shift-up shift and a shift-down shift not only in the power-on state but also in the power-off state. An object of the present invention is to provide a shift control device for a transmission.

[0013]

To achieve such an object, in the present invention, the engagement control means releases the front-stage engagement element and engages the next-stage engagement element to move from the front stage to the next stage. Is performed, the disengagement engaging force change characteristic of the front stage engagement element at each shift is set by a plurality of front stage control stages arranged continuously and in order,
Also, the engagement force change characteristic for engagement of the next-stage engagement element is set by a plurality of next-stage control stages that are continuously and sequentially arranged, and the front-stage control stage and the next-stage control stage are set according to the rotation change of the input shaft. It is executed in parallel to shift from the previous stage to the next stage. At this time, the previous control stage and the next control stage are continuously executed in the order of all stages or selected stages.

In this control device, a combination of a pre-stage control stage and a next-stage control stage that can be simultaneously executed,
A combination of the previous control stage and the next control stage that cannot be executed at the same time is set, and the previous control stage and the next control stage are executed in parallel by using only the combinations that can be executed simultaneously. To shift to. Note that the configuration of the plurality of front stage control stages and the plurality of next stage control stages that are respectively arranged continuously and in sequence in this way differs depending on whether the shift is a shift-up shift or a shift-down shift.

When the shift from the previous stage to the next stage is a shift-up shift, the engagement control means receives the shift-up shift command, and after waiting for a predetermined time, sets the engagement hydraulic pressure of the preceding stage engagement element to a predetermined level. Move to the preceding control stage that performs control to reduce in proportion, and at the same time, concurrently execute the next control stage that sets the engagement hydraulic pressure of the next stage engagement element to the hydraulic pressure that maintains the state immediately before engagement, The rotation speed of the input shaft corresponds to the vehicle speed when the preceding engagement element is engaged (hereinafter, this is referred to as the shift-up reference rotation speed NU0).
When the threshold value NU1 'becomes higher by a predetermined number of revolutions, the control proceeds to the next preceding control stage and the next control stage, and the input shaft rotation speed is higher than the threshold value NU1'. Feedback control of the engagement hydraulic pressure of the preceding stage engagement element is performed so as to match the number NU1, and at the same time control is performed to gradually increase the engagement hydraulic pressure of the next stage engagement element.

When the shift from the previous stage to the next stage is a shift down shift, in response to this shift down shift command,
The engagement control means determines the rotation speed of the input shaft as the input shaft rotation speed (hereinafter, referred to as the rotation speed of the input shaft corresponding to the vehicle speed when the next-stage engagement element is engaged).
This is referred to as a shift down reference rotational speed ND0), and a pre-stage control stage for controlling the engaging force of the pre-stage engaging element is executed so as to match the first shift-down target rotational speed ND1 at a higher rotational speed, and this control is performed. In parallel with the execution of the next-stage control stage that gradually increases the engagement force of the next-stage engagement element,
When the rotation speed of the input shaft is equal to or lower than the second downshift target rotation speed ND2 (ND0 <ND2 <ND1) which is higher than the downshift reference rotation speed ND0 and lower than the first downshift target rotation speed ND1. The engagement control means reduces the engagement force of the preceding stage engagement element so that the rotation speed of the input shaft is higher than the downshift reference rotation speed ND0 and the second downshift target rotation speed N.
Third downshift target rotation speed ND3 (ND0 lower than D2)
When <ND3 <ND2) or less, the process moves to the next pre-stage control stage and the next-stage control stage to minimize the engagement force of the pre-stage engagement element and maximize the engagement force of the next-stage engagement element. Take control.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a power transmission system of an automatic transmission equipped with a shift control device according to the present invention.
This transmission includes a torque converter 10 connected to an engine output shaft 9 and a transmission having a transmission input shaft 8a connected to a turbine of the torque converter 10.

This transmission has first, second and third planetary gear trains G1, G arranged in parallel on the transmission input shaft 8a.
2 and G3. Each planetary gear train has first to third sun gears S1, S2, and S3 located at the center, and first to third planetary pinions that revolve while rotating around the first to third sun gears S1, S2, and S3. P1, P2, P
3 and the first to third carriers C1, C2, C3 that rotatably hold the pinion and rotate in the same manner as the revolution of the pinion.
And first to third ring gears R1, R2 and R3 having internal teeth that mesh with the pinion. The first planetary gear train G1 and the second planetary gear train G2 are double pinion type planetary gear trains, and the first pinion P1 and the second pinion P2 are respectively two pinion gears P11, P12 and P21, P22 as shown. Composed of.

The first sun gear S1 is always connected to the input shaft 1, and the first carrier C1 is always fixed. The first ring gear R1 is connected to the second sun gear S via the third clutch K3.
The second sun gear S2 can be fixedly held by the first brake B1. Second carrier C
2 is directly connected to the third carrier C3 and the output gear 8
The rotation of the second carrier C2 and the third carrier C3, which are connected to b, serve as the output rotation of the transmission. The second ring gear R2 is directly connected to the third ring gear R3, and these two ring gears R2, R3 can be integrally fixedly held by the second brake B2 and engaged with the transmission input shaft 8a via the second clutch K2. It is detachably connected. Third
The sun gear S3 is detachably connected to the transmission input shaft 8a via the first clutch K1. A one-way brake B3 is arranged in parallel with the second brake B2.

As described above, each element (first to third sun gears S1 to S3, first to third carriers C1 to C3 and first to third ring gears S1 to S3), transmission input shaft 8a.
In the transmission configured by connecting the output gear 8b and the output gear 8b, the engagement and disengagement control of the first to third clutches K1 to K3 and the first and second brakes B1 and B2 is performed, thereby setting the shift speed and performing the shift control. It can be carried out. Specifically, as shown in Table 1 below, if engagement / disengagement control is performed, the forward movement 5
Speed (1ST, 2ND, 3RD, 4TH and 5TH),
Reverse speed 1 (REV) can be set. The speed reduction ratio (ratio) in each speed range changes depending on the number of teeth of each gear, and Table 1 shows an example of this ratio for reference.

In Table 1, the second brake B2 in 1ST is shown in parentheses, but the one-way brake B3 is used even if the second brake B2 is not engaged.
This is because the drive-side power transmission is performed by. That is, if the first clutch K1 is engaged, the second brake B
Even if 2 is not engaged, drive-side power transmission with a gear ratio of 1ST is possible, and 1ST is set. However, power cannot be transmitted in the opposite direction to the drive side. Therefore, 1ST where the second brake B2 is disengaged is a speed stage where the engine brake does not work, and if the second brake B2 is engaged, the engine brake It becomes an effective speed stage.

[0022]

[Table 1]

Next, a control device for controlling engagement / disengagement of the first to third clutches K1 to K3 and the first and second brakes B1 and B2 will be described with reference to FIGS. 2 to 4. In addition,
2 to 4 show respective parts of the control device, and these three figures constitute one control device. In addition,
Of the oil passages in each figure, the circled alphabet (A
Those with ~ I) indicate that they are connected to oil passages with the same circled alphabet in other figures. Further, in the figure, the mark x indicates that the port is open to the drain.

The operation control of the brakes and clutches for shift control is carried out by utilizing the hydraulic pressure of the hydraulic oil supplied from the tank 90 by the pump 91. Pump 91 to oil passage 1
The hydraulic fluid discharged to 01 acts on the regulator valve 20 via the oil passage 101a and is regulated to a predetermined line pressure P1. The hydraulic oil having the line pressure P1 is supplied to the oil passage 101 in FIG. A part of the oil discharged from the pump 91 is supplied to the oil passage 101 in this way, but the rest is sent from the regulator valve 20 to the oil passage 151. The hydraulic oil sent to the oil passage 151 is divided into oil passages 151a and 151b, the hydraulic oil flowing to the oil passage 151a is supplied to a torque converter (not shown), and the hydraulic oil flowing to the oil passage 151b is the first oil. After being supplied to the lubrication part L1 to lubricate this part, it is returned to the tank 90.

Oil passage 101 adjusted to the line pressure P1
The hydraulic oil of is supplied to the portion composed of FIGS. 3 and 4 for the shift control of the transmission. In this portion, a manual valve 25 connected to a shift lever on the driver's seat and operated by a driver's manual operation, five solenoid valves SA to SE, four hydraulically operated valves 30,
35, 40, 45 and four accumulators 51-54
And five hydraulic pressure sensors PS are provided. The solenoid valves SA and SC are normally open type valves and are opened when the solenoid is off, whereas the solenoid valves SB, SD and SE are normally closed type valves and are closed when the solenoid is off. . The valve 30
Is referred to as a first hydraulic relief valve, the valve 35 is referred to as a second hydraulic relief valve, the valve 40 is referred to as a brake relief valve, and the valve 45 is referred to as a switching valve.

Each of these valves is operated in response to the operation of the manual valve 25 and the operation of the solenoid valves SA to SE, and shift control and operation control of the lockup clutch of the torque converter are performed. The relationship between the operation of each solenoid valve SA to SE and the speed stage set in accordance with this operation in this case is as shown in Table 2 below. In addition, ON and OFF in Table 2 represent ON and OFF of the solenoid. In this table, turn on the solenoid
Although shown to be turned off, each solenoid valve is a duty control solenoid valve, and control is performed based on the duty ratio so that a desired gear shift characteristic can be obtained at the time of gear shift.

[0027]

[Table 2]

The above control will be described below. First, consider a case where the D range is set by the shift lever and the spool 26 of the manual valve 25 moves to the D position. In FIG. 3, the spool 26 is at the N position, and the right end hook portion is moved to the position indicated by D to the right so that the spool 26 is located at the D position. By this movement, the oil passage 1
The oil passage 102 branched from 01 communicates with the oil passage 103, and the working oil having the line pressure P1 is sent to the oil passage 103.

The hydraulic oil having the line pressure P1 also flows into the oil path 101 which branches off from the oil path 101, and further branches off from the oil path 110 into an oil path 115 and an oil path 111. Oil passage 115
Is further branched into an oil passage 116 connected to the solenoid SA and an oil passage 117 connected to the solenoid SC, and the line pressure P1 always acts on both solenoids SA and SC.
In addition, oil passages 111a and 11 branching from the oil passage 111
1b is the first and second hydraulic relief valves 3 respectively
0, 35 is connected to the right end, the oil passage 111 is connected to the right end of the brake relief valve 40, and the oil passage 112 is further connected.
It is also connected to the right end of the switching valve 45 via.
Therefore, the spools of these valves 30, 35, 40, 45 are constantly pressed to the left by receiving the line pressure P1.

When the D range is set, the speed stage is determined in accordance with the relationship between the engine load and the vehicle speed, and each solenoid valve SA to S is obtained to obtain this speed stage.
The operation of E is controlled as shown in Table 2. Therefore, the operation of the clutch and brake associated with the operation of the solenoid valve at each speed stage will be described.

First, consider the case where the first speed stage (1ST) is set as the speed stage. In this case, as shown in Table 2, only the solenoid valve SC is on and the other four are off. Therefore, at this time, the solenoid valve SA
Only the solenoids are opened and the other solenoids are closed. However,
The solenoid valve SE is used for engine brake operation control at the first speed, and is turned on when operating the engine brake. Since the line pressure P1 acts on the solenoid valve SA from the oil passage 116, the hydraulic oil having the line pressure P1 flows to the oil passage 120 through the solenoid valve SA. The oil passage 120 is connected to the manual valve 25, and when the manual valve 25 is in the D position, the oil passage 120 communicates with the oil passage 121.
Therefore, the hydraulic oil having the line pressure P1 is supplied to the first clutch K1 through the oil passage 121, and the first clutch K1
Are connected. The first accumulator 51 and the hydraulic sensor PS are connected to the oil passage 120. The line pressure P1 acts on the left end of the first hydraulic relief valve 30 via the oil passage 121a connected to the oil passage 121. However, the difference in pressure receiving area causes the oil pressure acting via the oil passage 111a to be predominant. The spool 31 of the valve 30 is in the state of leftward movement as shown in the figure.

On the other hand, the oil passage 12 connected to the second clutch K2
5 is connected to the solenoid valve SB, but since the solenoid valve SB is closed, the oil passage 125
Is connected to the drain through the valve SB, and the second clutch K2 is in the released state. The oil passage 130 connected to the third clutch K3 is connected to the oil passage 131 or 133 via the shuttle valve 57. The oil passage 131 is connected to the manual valve 25 via the oil passage 132, and when the manual valve 25 is at the D position, the oil passage 132 communicates with the drain. On the other hand, the oil passage 133 is also connected to the manual valve 25, and is also connected to the oil passage 134 at the D position. The oil passage 134 is connected to the solenoid valve SC, but since the solenoid valve SC is off, the oil passage 134 is connected to the drain through the valve SC.
Therefore, the third clutch K3 is also released. The oil passage 140 connected to the first brake B1 is a solenoid valve SD.
However, since the solenoid valve SD is closed, the oil passage 140 is connected to the drain through the valve SD, and the first brake B1 is also released.

The oil passage 167 connected to the second brake B2 is connected to the oil passage 166 or 170 via the shuttle valve 56. The oil passage 166 is connected to the solenoid valve SE via the brake relief valve 40, the oil passage 165, the switching valve 45, and the oil passage 163 in this order. Therefore, the engagement of the second brake B2 can be controlled by the solenoid valve SE, and thus the operation control of the engine brake at the first speed can be performed. Ie 1
In the speed stage, the operation control of the engine brake can be performed by controlling the operation of the solenoid valve SE. The oil passage 170 is connected to the oil passage 171 or 172 via the shuttle valve 58, and both the oil passages 171 and 172 are connected to the drain via the manual valve 25.

Next, consider the case of shifting to the second speed. In this case, only the solenoid valve SD is switched from off to on. When this state is compared with the state of the first speed stage, the only difference is that the solenoid valve SD is opened. Therefore, the first clutch K1 remains engaged. When the solenoid valve SD is opened, the oil passage 145
The hydraulic oil having the line pressure P1 is supplied to the first brake B1 via the and is engaged. As a result, the first clutch K1 and the first brake B1 are engaged and the second speed is set.

When the solenoid valve SD is opened, the hydraulic oil having the line pressure P1 also acts on the brake relief valve 40 and the switching valve 45 via the oil passages 140, 141 and 142, and this hydraulic pressure P1 causes both valves to operate. The spools 41 and 46 of 40 and 45 are pressed to the right. As described above, the line pressure P1 also acts on the right ends of the spools 41 and 46, but the spools 41 and 46 are both moved to the right due to the difference in pressure receiving area. By the right movement of the spools 41 and 46, the solenoid valve SE and the second brake B2, which were connected at the first speed, are connected.
The oil passage 16 that is disconnected from the communication with the second brake B2
6 is connected to the drain via the brake relief valve 40. Therefore, in the second gear, the second brake B2 is always released.

Next, consider the case of shifting to the third speed. In this case, only the solenoid valves SC and SD are switched from on to off, and all the solenoid valves are turned off. As a result, the solenoid valve SC is opened and the solenoid valve SD is closed from the second gear. Since the solenoid valve SA is thus open, the first clutch K1 remains engaged. When the solenoid valve SD is closed, the oil passage 145
The oil pressure is not supplied to the oil passage 145, and the oil passage 145 communicates with the drain via the solenoid valve SD. Therefore, the twelfth brake B1 is released. At the same time, the oil passages 140, 141
And 142, the hydraulic pressure acting on the brake relief valve 40 and the switching valve 45 also becomes zero, and the spool 4 of both valves 40 and 45 is caused by this hydraulic pressure.
There is no pressing force on 1,46.

On the other hand, when the solenoid valve SC is opened, the hydraulic oil having the line pressure P1 is supplied to the oil passage 134. Since the oil passage 134 is connected to the oil passage 133 via the manual valve 25, the hydraulic oil having the line pressure P1 is supplied from the shuttle valve 57 to the third clutch K3 and the third clutch K3 is engaged. In this way, the first clutch K1 and the third clutch K3 are engaged and
The speed is set.

Next, consider the case of shifting from the third speed to the fourth speed. In this case, only the solenoid valves SB and SC are switched from off to on. As a result, the solenoid valve SB is opened from the state of the third gear,
The solenoid valve SC is closed. Since the solenoid valve SA is thus opened, the first clutch K
1 remains engaged. When the solenoid valve SC is closed, contrary to the case of the third speed, the supply of the line pressure P1 to the third clutch K3 is cut off and released. At the same time, the supply of the line pressure P1 to the left side of the first and second hydraulic relief valves 30, 35 and the switching valve 45 via the oil passages 175, 176, 177 is also cut off, and the oil passage 104a is passed through the oil passage 178. The supply of the line pressure P1 to the left side of all the brake relief valves 40 is also cut off.

For this reason, the spool 31 of the first hydraulic relief valve 30 is moved to the left again as shown in the figure, so that the hydraulic oil having the line pressure P1 is passed from the oil passage 103 through the first hydraulic relief valve 30 to the oil passage. 107 is supplied to the second clutch K2 via the oil passage 125 from the opened solenoid valve SB, and the second clutch K2 is connected. In this way, the first clutch K3 and the second clutch K2 are engaged to set the fourth speed.

Next, consider the case of shifting from the fourth speed to the fifth speed. In this case, the solenoid valve SA is switched from off to on and the solenoid valve SC is switched from on to off. As a result, from the state of the fourth gear,
Solenoid valve SA is closed and solenoid valve S
C is released. When the solenoid valve SA is closed, the supply of the line pressure P1 via the oil passages 120 and 121 is cut off, and the first clutch K1 is released. Further, the hydraulic pressure in the oil passage 121a becomes zero due to the closing of the solenoid valve SA, and the spool 31 of the first hydraulic pressure relief valve 30 remains left-moving. At the same time, since the solenoid valve SB remains on, the second clutch K2 is maintained in the engaged state.

On the other hand, when the solenoid valve SC is opened, as described above, the hydraulic oil having the line pressure P1 is supplied to the oil passage 134, and the manual valve 2
5, the oil is supplied to the third clutch K3 via the oil passage 133 and the oil passage 130, and the third clutch K3 is engaged. In this way, the second clutch K2 and the third clutch K3 are engaged to set the fifth speed.

As described above, in the shift control in the D range, the solenoid valve SE is set at 1ST (low speed stage).
The hydraulic fluid controlled and output by the solenoid valve SE is supplied to the second brake B2 through the switching valve 45 and the brake relief valve 40, but is output from the solenoid valve SE at 2ND to 5TH (middle and high speed stages). The oil is supplied to the torque converter via the oil passages 160 and 164 and used for controlling the lockup clutch operation. That is, in this example, the solenoid valve SE is used for controlling the operation of the second brake B2 when 1ST is set as the speed stage,
When the speed stage is set from 2ND to 5TH, it is used for controlling the operation of the lockup clutch.

The shift control in the D range has been described above. Next, consider the case where the N range is set. In this case, the clutches K1, K2, K3 and the brakes B1, B2 are connected to the drain via the manual valve 25, and all of them are released to be in a neutral state.

Next, consider the case where the R range is set. In this case, the spool 26 of the manual valve 25
Is moved to the left, and hydraulic oil having a line pressure P1 is supplied from the oil passage 102 to the oil passage 132. Further, all solenoid valves SA to SE are turned off. Therefore, the first clutch K
The oil passage 121 connected to 1 is connected to the drain in the manual valve 25 to release the first clutch K1, and the oil passage 125 connected to the second clutch K2 is connected to the solenoid valve SB.
The second clutch K2 is also released by communicating with the drain from.

The oil passage 130 connected to the third clutch K3 is connected to the oil passage 132 via the shuttle valve 57 and the oil passage 131.
Hydraulic fluid supplied to the oil passage 132 is supplied to the third clutch K3, and the third clutch K3 is engaged. The oil passage 145 connected to the first brake B1 communicates with the drain from the solenoid valve SD, and the first brake B1 is released.

On the other hand, the oil passage 16 connected to the second brake B2
7 is connected to the oil passage 171 or the oil passage 172 from the shuttle valve 56 via the oil passage 170 and the shuttle valve 58. The oil passage 171 is connected to the oil passage 120 from the manual valve 25.
Is connected to the solenoid valve SA via the oil passage 172, and the oil passage 172 is connected to the solenoid valve SC from the manual valve 25 via the oil passage 134. Both solenoid valves SA, SC
Are both normally open types. Therefore, the hydraulic oil having the line pressure P1 flows through the oil passages 171 and 172, and the second brake B2 is engaged. In this way, the third clutch K3 and the second brake B2 are engaged to set the reverse gear.

As described above, as shown in Table 1, the setting of each shift speed is such that each clutch K1 to K3 and each brake B1, B is set.
2 (that is, the engagement element) can be controlled by controlling the engagement, and this engagement control can be performed by controlling the operation of each solenoid valve SA to SE as shown in Table 2. Therefore, the shift control in this automatic transmission is performed by controlling the operation of each solenoid valve SA-SE. As shown in FIG. 5, the shift control device for this automatic transmission controls each solenoid valve SA-SE. It has a shift control controller 200 that outputs an operation signal.
The shift control controller 200 includes an accelerator opening sensor 201 that detects a depression amount (accelerator opening) of an accelerator pedal, and an input rotation sensor 202 that detects a transmission input shaft rotation speed (or a turbine shaft rotation speed of a torque converter). , An output rotation sensor 203 for detecting the vehicle speed (or the output shaft speed of the transmission), a shift position sensor 204 for detecting the shift lever position, etc. are connected, and a shift determination is made based on detection signals from these sensors. According to the determination, a shift command is output to each solenoid valve SA to SE to perform a predetermined shift.

The shift control performed by this shift control device will be described. As shown in Table 1, each shift stage has a plurality of engaging elements (the clutches K1 to K3 and the brake B1,
It is set by engaging two engaging elements of B2), but when shifting between adjacent gears, one engaging element is released and another one is newly engaged. It is done by combining. In this case, the released engagement element (clutch or brake) is referred to as a front stage engagement element, and the newly engaged engagement element is referred to as a next stage engagement element.

This shift control is performed according to the flow shown in FIG. First, the detected value from each of the above-mentioned sensors is input to determine the shift (steps S1 and S2). And
When shifting is performed, it is determined whether the shifting is upshifting or downshifting (step S3). In the case of upshift, the process proceeds to step S4, and in the case of downshift, the process proceeds to step S5 to perform the corresponding shift control. When the command output signal to the solenoid valve is set in this shift control, this signal is output to the solenoid valve (step S6), and the gear shift operation is actually performed.

First, shift up control (step S4)
Will be described with reference to the flow of FIG. 7. As described above, the shift-up is also performed by releasing the front-stage engagement element and engaging the next-stage engagement element. Therefore, in the shift-up control, these are controlled in parallel. As this parallel control, the disengagement execution stage of the preceding stage engagement element is determined in step S11, and the engagement execution stage of the next stage engagement element is determined in step S16.
The output is set for each stage according to the above, and the output hydraulic pressure is set based on the output setting (steps S12, 13, 14 and steps S17, 18, 19).

The respective stages are configured as shown in Tables 3 and 4 below. Table 3 shows the contents of each stage, and Table 4
Indicates possible combinations of each stage. In Table 4, ◯ indicates a combination of the preceding control stage and the next control stage that can occur simultaneously (that is, executable) in the shift control, and x indicates a combination that cannot occur (inexecutable) at the same time. In each shift control for both the front control stage and the next control stage, control is continuously performed in the order of stage numbers shown in Table 3, and control for returning to the stage is not performed in each shift control. Depending on the type of gear shift, some stages may be skipped, that is, stages may be selected and controlled, instead of controlling all stages. However, even in this case, control is performed in order from the smallest stage number.

[0052]

[Table 3]

[0053]

[Table 4]

Regarding the output hydraulic pressure setting for each of these stages, first, in the case of power-on / upshift,
This will be described with reference to FIG. In this figure, the time of the transmission input shaft speed Ni, the engagement hydraulic pressure Pp of the preceding stage engagement element and the engagement hydraulic pressure Pn of the next stage engagement element in the case of a typical power-on upshift is shown. Shows. When the shift-up gear shift command is output, both the front-stage and next-stage engagement elements move to stage ST0. ST0 is a standby stage, and both stand by for a predetermined time.

The engagement hydraulic pressure Pp of the preceding stage engagement element shifts to the stage ST1 after waiting in the stage ST0 and reduces the engagement hydraulic pressure at a predetermined speed. As a result, the engagement force of the front-stage engagement element decreases, and when this falls below the engine torque equivalent value transmitted to the input shaft, the front-stage engagement element begins to slip. The input shaft rotation speed Ni corresponding to the vehicle speed when the front-stage engagement element is engaged is referred to as a shift-up reference rotation speed NU0. At this time, since the power is on, the input shaft rotation speed Ni starts to increase. When the input shaft rotational speed Ni reaches a threshold value NU1 'higher than the shift-up reference rotational speed NU0 by a predetermined rotational speed (30RPM), the stage ST2 is entered, and the input shaft rotational speed is set to the first value higher than the shift-up reference rotational speed NU0. Engagement force feedback control of the preceding stage engagement element is performed so as to match the first shift-up target rotation speed NU1 that is higher by a predetermined rotation speed (40 RPM).
By this feedback control, the engagement hydraulic pressure Pp of the preceding stage engagement element is set as Pp (1). Although Pp (1) is linear in this figure, it is the hydraulic pressure that fluctuates up and down due to feedback control.

In parallel with this, the engagement hydraulic pressure P of the next-stage engagement element
n control is also performed, and after waiting for a short time (stage ST0), the hydraulic pressure Pn (1) required to close the clearance of this engagement element is set at stage ST1. This hydraulic pressure Pn (1) moves the piston of the next-stage engagement element by the clearance of the friction plate or the like, and brings the next-stage engagement element into the state immediately before the engagement. At this time, the hydraulic pressure P
When n (1) is too high and the engagement of the next-stage engagement element starts, the input shaft rotation speed Ni decreases due to the intermeshing state. Is slightly decreased to set the clearance closing hydraulic pressure Pn (2) at the stage ST3.

Then, as described above, the preceding stage engagement element shifts to the stage ST2, and at the same time, the next stage engagement element shifts to the stage ST4 to gradually increase the hydraulic pressure Pn (3) of the next stage engagement element. During this period, the front-stage engagement element is feedback-controlled to keep the input shaft rotation speed Ni at the first shift-up target rotation speed NU1, but the oil pressure Pn (3) of the next-stage engagement element gradually increases. When the lever engaging force increases, the input shaft rotation speed Ni decreases. Due to this decrease, when the input shaft rotation speed Ni becomes lower than the second shift-up rotation speed NU2 (however, NU2 <NU1) higher than the reference rotation speed NU0 by the second predetermined rotation speed (20RPN), the preceding stage engagement element The engagement hydraulic pressure Pp is reduced to Pp (2), and the stage shifts to stage ST3. As a result, the engagement of the front-stage engagement element is almost released.

The stage ST2 in this front stage engagement element
Is a control such as engagement in an engagement element having a one-way clutch, so this is referred to as one-way clutch control (OWC control). This one-way clutch control is specifically performed as shown in the flow charts of FIGS. In this control S20, the transmission input shaft rotation speed Ni and the transmission output shaft rotation speed No are read,
Based on this, the second shift-up target rotational speed NU2 is calculated (steps S21, 22, 23). When the transmission input shaft rotation speed Ni is higher than the second shift-up target rotation speed NU2, feedback control for matching the transmission input shaft rotation speed Ni with the first shift-up target rotation speed NU1 (this is called slip control Is called (step S)
30), when the transmission input shaft rotation speed Ni becomes smaller than the second shift-up target rotation speed NU2, the grip change control for lowering the oil pressure of the preceding stage engagement element is performed (step S4).
0).

In the slip control S30, the shift-up reference rotation speed NU0 is calculated and the rotation speed NU0 is calculated.
And the actual input shaft rotation speed Ni are calculated, and the target input shaft rotation speed angular acceleration is calculated according to this deviation (step S
31-S33). This angular acceleration is an acceleration for bringing the actual input shaft rotation speed Ni close to the reference rotation speed NU0, and is set to a larger value as the deviation is larger. Then, the deviation between this target angular acceleration and the actual input shaft rotation angular acceleration is calculated, and the hydraulic pressure correction amount of the preceding stage engagement element is calculated so as to obtain the target angular acceleration. If the solenoid output in step S6 is performed based on the calculated correction amount, the input shaft rotation Ni is controlled to match the first shift-up target rotation speed NU1. Further, as described above, the grip change control S40 is started at the same time when the engagement of the next-stage engagement element is started, and the transition (release of the previous-stage engagement element to the engagement of the next-stage engagement element) is performed. This is a control for smoothly performing the gripping of the composite element). Therefore, the hydraulic pressure reduction rate of the front stage engagement element is set, and the hydraulic pressure is corrected so as to obtain this pressure reduction rate (steps S41 and S42).

When this grip change control is performed, the next-stage engagement element has started engagement as described above, so the input shaft rotation speed Ni continues to decrease. Then, when the third shift-up target rotation speed NU3 lower than the reference rotation speed NU0 by the third predetermined rotation speed (20 RPM) is reached, the stage ST5 is entered and the engagement hydraulic pressure Pn (3 of the next-stage engagement element is set. ) Is stopped and the oil pressure Pn at that time is increased.
It is held in (4). As a result, the input shaft rotation speed Ni decreases at a predetermined reduction rate, and this decreases from the rotation speed Nn corresponding to the vehicle speed when the next-stage engagement element is engaged to the predetermined rotation speed (30
RPN), the stage S
At T6, the engagement hydraulic pressure is reduced to Pn (5) to reduce the reduction rate of the input shaft rotation speed Ni. As a result, the engagement of the next-stage engagement element can be smoothly completed. When the input shaft rotation speed Ni matches the rotation speed Nn, the hydraulic pressure of the next-stage engagement element is set to the maximum value Pn (MAX).
And the power-on shift-up shift is completed.

Next, the power off / shift up shift will be described with reference to FIG. In this figure, the time of the transmission input shaft speed Ni, the engagement hydraulic pressure Pp of the preceding stage engagement element, and the engagement hydraulic pressure Pn of the next stage engagement element in the case of a typical power-off / upshift are shown. Shows. When the shift-up gear shift command is output, both the front-stage and next-stage engagement elements move to stage ST0. ST0 is a standby stage, and both stand by for a predetermined time.

The engagement hydraulic pressure Pp of the preceding stage engagement element shifts to the stage ST1 after waiting for a predetermined time in the stage ST0, and reduces the engagement hydraulic pressure at a predetermined speed. As a result, the engagement force of the front-stage engagement element decreases, and when this falls below the engine torque equivalent value transmitted to the input shaft, the front-stage engagement element begins to slip. It should be noted that the input shaft rotation speed Ni corresponding to the vehicle speed when the preceding stage engagement element is in the engaged state
Is referred to as a shift-up reference rotation speed NU0. At this time, since the power is off, the input shaft rotation speed Ni starts to decrease.

In parallel with this, the engagement hydraulic pressure P of the next-stage engagement element
n control is also performed, and after waiting for a short time (stage ST0), the hydraulic pressure Pn (1) required to close the clearance of this engagement element is set at stage ST1. This hydraulic pressure Pn (1) moves the piston of the next-stage engagement element by the clearance of the friction plate or the like, and brings the next-stage engagement element into the state immediately before the engagement. At this time, the hydraulic pressure P
When n (1) is too high and the engagement of the next-stage engagement element starts, the input shaft rotation speed Ni decreases due to the intermeshing state. Is slightly decreased to set the clearance closing hydraulic pressure Pn (2) at the stage ST3.

On the other hand, as described above, the input rotation Ni starts to decrease, and this is the third shift-up target rotation speed NU which is lower than the reference rotation speed NU0 by the third predetermined rotation speed (20 RPM).
When the pressure is reduced to 3, the stage ST5 is entered and the engagement hydraulic pressure of the next-stage engagement element is increased to a predetermined hydraulic pressure Pn (4) required to engage the engagement element to some extent. On the other hand, at this time, at the same time, the engagement hydraulic pressure Pp of the preceding engagement element shifts to the stage ST3 and is reduced to the minimum value.

As a result, the input shaft rotational speed Ni decreases as it is, and this decreases to a rotational speed NU4 higher by a predetermined rotational speed (30 RPN) than the rotational speed Nn corresponding to the vehicle speed when the next-stage engaging element is engaged. At this time, the engagement oil pressure Pn of the next-stage engagement element shifts to the stage ST6 to change the engagement oil pressure Pn to Pn.
The amount of decrease in the input shaft rotation speed Ni is reduced by slightly decreasing the amount to (5). As a result, the engagement of the next-stage engagement element can be smoothly completed.

The input shaft rotation speed Ni is the above-mentioned rotation speed N.
When it matches n, the hydraulic pressure of the next-stage engagement element is set to the maximum value Pn (M
AX) to complete this power-on upshift. In this way, in the case of power-off / upshift, the stage ST2 of the preceding stages in Table 3 is
The stage ST4 of the latter stages is not used, and stages other than these stages are selected and controlled. However, even in this case, the control is performed in the order of the numbers in Table 3, and the control is performed based on the executable combinations indicated by the circles in Table 4.

Since the control contents differ depending on whether the power is on or off as described above, in the present control,
In the gear shift determination in step S2, which state is detected. This detection is performed by detecting the throttle opening θTH and the vehicle speed V and determining whether the corresponding points are in the ON region or the OFF region shown in FIG.

Next, shift down control (step S5)
This will be described with reference to the flow of FIG. Downshifting is also performed by releasing the front stage engagement element and engaging the next stage engagement element. Therefore, even in the downshift control, these are controlled in parallel, the release execution stage determination of the front stage engagement element is performed in step S51, and the step S51 is performed.
At step 56, the engagement execution stage of the next-stage engagement element is determined, and the stage number of each stage. Output is set for each stage according to the above, and the output hydraulic pressure is set based on the output setting (steps S52, 53, 54 and steps S57, 58, 5).
9).

Each stage is constructed as shown in Tables 5 and 6 below. Table 5 shows the contents of each stage.
Indicates possible combinations of each stage. In Table 5, ◯ indicates a combination of the preceding control stage and the next control stage that can occur simultaneously in the shift control, and x indicates a combination that cannot occur simultaneously.

[0070]

[Table 5]

[0071]

[Table 6]

Regarding the output oil pressure setting for each of these stages, first, the case of power-on and down-shift is shown in FIG.
This will be described with reference to FIG. This figure shows the transmission input shaft speed N in the case of a typical power-on downshift.
i, the engagement hydraulic pressure Pp of the preceding stage engagement element and the engagement hydraulic pressure Pn of the next stage engagement element are shown with time. When the downshift command is output, both the front-stage and next-stage engagement elements move to stage ST0. ST0 is a standby stage, and both stand by for a predetermined time.

The engagement hydraulic pressure Pp of the preceding stage engagement element shifts to the stage ST1 after waiting in the stage ST0, and reduces the engagement hydraulic pressure at a predetermined speed. As a result, the engagement force of the front-stage engagement element decreases, and when this falls below the engine torque equivalent value transmitted to the input shaft, the front-stage engagement element begins to slip. At this time, since the power is on, this slip causes the input shaft speed Ni to start increasing. When the input shaft rotational speed Ni becomes larger than the first judgment value ND 'which is larger than the input shaft rotational speed Np at the start of gear shifting by a predetermined value (20 RPM), the stage ST2 is entered, and the input shaft rotational speed N is reached.
Engagement force control of the preceding stage engagement element is performed such that i is increased at a predetermined increase rate. This control is, for example, the same control as the slip control shown in FIG. 9, and at this time, the hydraulic pressure of the front stage engagement element is Pp (1).

In the downshift control, the input shaft rotational speed corresponding to the vehicle speed when the next-stage engaging element is engaged is set as the downshift reference rotational speed ND0. The input shaft rotation speed increases due to the control at the stage ST2, and the predetermined rotation speed (80 RPM) from the downshift reference rotation speed ND0.
When the threshold value ND ″ becomes higher than that, the stage shifts to ST3 so that the input shaft speed matches the first downshift target speed ND1 which is higher than the downshift reference speed ND0 by the first predetermined speed (100 RPM). Engagement force feedback control of the preceding stage engagement element is performed, and the engagement hydraulic pressure Pp of the preceding stage engagement element is Pp (2) by this feedback control.
Is set as follows. Although Pp (2) is linear in this figure, it is the hydraulic pressure that fluctuates up and down due to feedback control.

In parallel with this, the engagement hydraulic pressure P of the next-stage engagement element
n control is also performed, and after waiting for a short time (stage ST0), the hydraulic pressure Pn (1) required to close the clearance of this engagement element is set at stage ST1. This hydraulic pressure Pn (1) moves the piston of the next-stage engagement element by the clearance of the friction plate or the like, and brings the next-stage engagement element into the state immediately before the engagement. This hydraulic pressure Pn
(1) is too high, causing co-engagement, and the input shaft speed Ni
When the increase rate of
As shown in, the hydraulic pressure Pn (2) decrease control is performed.

Then, as described above, the front stage engagement element shifts to the stage ST3, and at the same time, the rear stage engagement element shifts to the stage ST3 to increase the hydraulic pressure Pn (3) of the rear stage engagement element at a predetermined increase rate. During this period, the front-stage engagement element is subjected to feedback control in which the input shaft rotation speed Ni is maintained at the first downshift target rotation speed ND1, but the hydraulic pressure Pn (3) of the rear-stage engagement element increases and this relationship is increased. When the resultant force increases, the input shaft rotation speed Ni decreases. This drop causes
The second shift-down speed ND2 in which the input shaft speed Ni is higher than the reference speed ND0 by a second predetermined speed (60 RPN).
(However, when it becomes lower than ND2 <ND1), the engagement hydraulic pressure Pp (2) of the preceding stage engagement element is reduced to Pp (3), and the process proceeds to stage ST4. As a result, the engagement of the front-stage engagement element is almost released. Since the stage ST3 in the preceding stage engagement element is also control like engagement in the engagement element having the one-way clutch, this is also referred to as one-way clutch control (OWC control). This one-way clutch control is also specifically performed as shown in the flows of FIGS.

When the engagement of the former stage engagement element is released in this way, the latter stage engagement element has started the engagement as described above, and therefore the input shaft rotational speed Ni continuously decreases. . Then, a third downshift target rotation speed ND3 which is higher than the reference rotation speed NU0 by a third predetermined rotation speed (20 RPM).
(However, when it falls to ND3 <ND2), the stage S
After shifting to T4, the engagement oil pressure of the latter-stage engagement element is the maximum oil pressure Pn.
While increasing to (MAX), the oil pressure of the front-stage engagement element is gradually released as indicated by Pp (3). As a result, the engagement of the rear-stage engagement element is smoothly completed, and the downshift is completed.

Next, the case of power-off / downshift will be described with reference to FIG. When the downshift command is output, both the front-stage and next-stage engagement elements move to stage ST0. ST0 is a waiting stage,
Both stand by for a predetermined time. The engagement hydraulic pressure Pp of the former stage engagement element is
The process proceeds to the stage ST1 and the engagement hydraulic pressure is reduced at a predetermined speed. As a result, the engagement force of the front-stage engagement element decreases, and when this falls below the engine torque equivalent value transmitted to the input shaft, the front-stage engagement element begins to slip.

At this time, since the power is off, this slip causes the input shaft speed Ni to decrease, and the input shaft speed Ni is smaller than the input shaft speed Np at the start of gear shifting by a predetermined value (20 RPM). When the judgment value ND 'is reached, the process proceeds to stage ST3, and the engagement force control of the preceding stage engagement element is performed so as to increase the input shaft rotation speed Ni at a predetermined increase rate. In the downshift control, the input shaft rotation speed corresponding to the vehicle speed when the next-stage engagement element is engaged is set as the downshift reference rotation speed ND0.

In parallel with this, the engagement hydraulic pressure P of the next-stage engagement element
n control is also performed, and after waiting for a short time (stage ST0), the hydraulic pressure Pn (1) required to close the clearance of this engagement element is set at stage ST1. This hydraulic pressure Pn (1) moves the piston of the next-stage engagement element by the clearance of the friction plate or the like, and brings the next-stage engagement element into the state immediately before the engagement. This hydraulic pressure Pn
(1) is too high, causing co-engagement, and the input shaft speed Ni
When the increase rate of
As shown in, the hydraulic pressure Pn (2) decrease control is performed.

Then, as described above, the front stage engagement element shifts to the stage ST3, and at the same time, the rear stage engagement element shifts to the stage ST3 to increase the hydraulic pressure Pn (3) of the rear stage engagement element at a predetermined increase rate. That is, during this period, the engaging force of the rear-stage engaging element and the front-stage engaging element is feedback-controlled to increase the input shaft rotation speed Ni at a predetermined increase rate.

As a result of this increase, when the input shaft rotation speed Ni becomes higher than the downshift rotation speed ND3 which is higher than the reference rotation speed ND0 by the second predetermined rotation speed (20RPN), the engagement hydraulic pressure Pp (2 of the preceding stage engagement element is obtained. ) Is reduced to Pp (3), and the process proceeds to stage ST4. As a result, the engagement of the front-stage engagement element is almost released. Since the stage ST3 in the preceding stage engagement element is also control like engagement in the engagement element having the one-way clutch, this is also referred to as one-way clutch control (OWC control). This one-way clutch control is also specifically performed as shown in the flows of FIGS.

At this time, at the same time, the engagement hydraulic pressure P of the latter-stage engagement element is set.
n also shifts to the stage ST4, and the engagement hydraulic pressure of the latter-stage engagement element is increased to the maximum hydraulic pressure Pn (MAX). As a result, the engagement of the rear-stage engagement element is smoothly completed, and the downshift is completed.

As described above, according to the present invention, the disengagement engagement force change characteristic of the front stage engagement element is set by a plurality of front stage control stages arranged continuously and in sequence when shifting from the front stage to the next stage. In addition, the engaging force change characteristic for engagement of the next-stage engagement element is also set by a plurality of next-stage control stages arranged continuously and in sequence, and the front-stage control stage and the next-stage control stage are set according to the rotation change of the input shaft. Are executed in parallel to shift from the previous stage to the next stage. At this time, the previous control stage and the next control stage are executed continuously in the order of all stages or selected stages, respectively. To do. Therefore, optimal shift control can be performed for each shift, and each shift can be performed smoothly and without delay.

In this control device, a combination of the previous control stage and the next control stage which can be executed simultaneously,
A combination of the previous control stage and the next control stage that cannot be executed at the same time is set, and the previous control stage and the next control stage are executed in parallel by using only the combinations that can be executed simultaneously. Since the shift to the shift is performed, it is easy to perform the optimum control for each shift.
In order to optimally control each shift, a configuration of a plurality of front stage control stages and a plurality of next stage control stages that are continuously and sequentially arranged is a case where the shift is a shift up shift and a shift down shift. It depends on the case.

When the shift from the previous stage to the next stage is the shift-up shift, the engagement control means receives the shift-up shift command, and after waiting for a predetermined time, the engagement hydraulic pressure of the preceding stage engagement element is changed. Move to the previous stage control stage that performs control to reduce at a predetermined rate, and concurrently execute the next stage control stage that sets the engagement hydraulic pressure of the next stage engagement element to the hydraulic pressure that holds the state immediately before engagement in parallel with this. However, the rotational speed of the input shaft is higher than the input shaft rotational speed (hereinafter, referred to as shift-up reference rotational speed NU0) corresponding to the vehicle speed when the preceding engagement element is engaged by a predetermined rotation speed. When the threshold value NU1 'is reached, the process proceeds to the next control stage and the next control stage, so that the input shaft speed matches the shift-up target speed NU1 higher than the threshold value NU1'. Engagement hydraulic pressure of the former stage engagement element Performs feedback control, performs control to increase at the same time gradually the engagement oil pressure of the next engaging element, thereby it is possible to perform optimum shift-up control.

Further, when the shift from the previous stage to the next stage is the shift down shift, the engagement control means receives the shift up shift command and changes the rotational speed of the input shaft by the engagement element of the next stage. Input shaft rotation speed corresponding to the vehicle speed when the vehicle is running (hereinafter referred to as shift-down reference rotation speed ND0)
The pre-stage control stage that controls the engagement force of the pre-stage engagement element is executed so as to match the first rotation speed downshift target speed ND1 of higher rotation, and the engagement of the next-stage engagement element is performed in parallel with this control. The next control stage that gradually increases the resultant force is executed, and the rotation speed of the input shaft is the downshift reference rotation speed N.
The second shift-down target speed ND2 (ND0 <ND2 <which is higher than D0 and lower than the first shift-down target speed ND1
When it becomes ND1) or less, the engagement control means reduces the engagement force of the preceding stage engagement element, the rotation speed of the input shaft is higher than the downshift reference rotation speed ND0, and the second downshift target rotation speed. Third downshift target rotation speed N lower than ND2
When D3 (ND0 <ND3 <ND2) or less is reached, the process moves to the next pre-stage control stage and the next-stage control stage to minimize the engagement force of the previous stage engagement element and reduce the engagement force of the next stage engagement element. The control that maximizes the shift is performed, and the optimum downshift control can be performed.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing a power transmission path of an automatic transmission in which shift control is performed by a shift control device according to the present invention.

FIG. 2 is a hydraulic circuit diagram showing a shift control device for the automatic transmission.

FIG. 3 is a hydraulic circuit diagram showing a shift control device of the automatic transmission.

FIG. 4 is a hydraulic circuit diagram showing a shift control device of the automatic transmission.

FIG. 5 is a schematic block diagram showing the configuration of the shift control device.

FIG. 6 is a flowchart showing the contents of shift control by this shift control device.

FIG. 7 is a flowchart showing the contents of shift-up shift control by this shift control device.

FIG. 8 is a flowchart showing the content of shift control by this shift control device.

FIG. 9 is a flowchart showing the content of shift control by this shift control device.

FIG. 10 is a flowchart showing the content of shift control by this shift control device.

FIG. 11 is a graph showing changes over time in the input shaft rotation speed, the hydraulic pressure of the preceding stage engagement element and the hydraulic pressure of the next stage engagement element in the power-on / upshift control.

FIG. 12 is a graph showing changes over time in the input shaft rotation speed, the hydraulic pressure of the preceding stage engagement element, and the hydraulic pressure of the next stage engagement element in the power-off / upshift control.

FIG. 13 is a graph showing a power on / off determination map corresponding to throttle opening and vehicle speed.

FIG. 14 is a flowchart showing the contents of shift-down shift control by the shift control device.

FIG. 15 is a graph showing changes over time in the input shaft rotation speed, the hydraulic pressure of the preceding stage engagement element, and the hydraulic pressure of the next stage engagement element in the power-on / downshift control.

FIG. 16 is a graph showing the changes over time in the input shaft speed, the hydraulic pressure of the preceding stage engagement element, and the hydraulic pressure of the next stage engagement element in the power-off / downshift control.

[Explanation of symbols]

 10 Torque Converter 20 Regulator Valve 25 Manual Valve 30 First Hydraulic Relief Valve 35 Second Hydraulic Relief Valve 40 Brake Relief Valve 45 Switching Valve SA-SE Solenoid Valve K1-K3 Clutch B1, B2 Brake

Claims (5)

[Claims] 1. An input shaft for receiving a driving force from an engine, an output shaft for transmitting the driving force to a wheel, a plurality of power transmission paths formed between the input shaft and the output shaft, and these power transmission paths. It has a plurality of engagement elements that are selectively set and engagement control means that controls the engagement force of these engagement elements, and this engagement control means causes the preceding stage engagement element of the plurality of engagement elements. In a shift control device for an automatic transmission that shifts the power transmission path by engaging the next-stage engagement element and switching the power transmission path, and releasing the front-stage engagement element at each shift. The engaging force change characteristic for use by a plurality of front-stage control stages that are continuously and sequentially arranged, and the engaging force change characteristic for engagement of the next-stage engaging element is also set to a plurality of next-stage stages that are continuously and sequentially arranged. Set by the control stage, The preceding control stage and the next control stage are executed in parallel according to the change in the rotation of the shaft to shift the speed from the preceding stage to the next stage. Execution of the preceding control stage and the next control stage Is a gear shift control device for an automatic transmission, which continuously executes all stages or selected stages in that order. 2. A combination of the preceding control stage and the next control stage that can be executed simultaneously and a combination of the preceding control stage and the next control stage that cannot be executed at the same time are set. The automatic transmission according to claim 1, wherein the preceding control stage and the next control stage are executed in parallel using a possible combination so as to shift from the preceding stage to the next stage. Shift control device. 3. The configuration of the plurality of continuous and sequentially arranged front stage control stages and the plurality of continuously and sequentially arranged next stage control stages is a shift-up shift and a shift-down shift. The shift control device for an automatic transmission according to claim 1 or 2, wherein the shift control device is different from that in one case. 4. The shift from the preceding stage to the next stage is a shift-up shift, and in response to this shift-up shift command, the engagement control means, after waiting for a predetermined time, engages the preceding stage engagement element. The next-stage control stage shifts to the previous-stage control stage that performs control to reduce the hydraulic pressure at a predetermined rate, and at the same time, sets the engagement hydraulic pressure of the next-stage engagement element to a hydraulic pressure that maintains the state immediately before the engagement. The input shaft rotation speed is a predetermined rotation from the input shaft rotation speed (hereinafter, referred to as a shift-up reference rotation speed NU0) corresponding to the vehicle speed when the preceding engagement element is engaged. When the threshold value NU1 'for high rotation is reached, the process proceeds to the next control stage and the next control stage, and the input shaft rotation speed is higher than the threshold value NU1' for the shift-up target rotation speed NU1. The front stage engagement required to match Engagement performed the hydraulic pressure feedback control, the shift control system for an automatic transmission of claim 1 wherein, characterized in that performs control of increasing at the same time gentle engagement oil pressure of the next stage engaging elements. 5. The shift from the preceding stage to the next stage is a shift down shift, and in response to this shift down shift command, the engagement control means sets the rotational speed of the input shaft to the next stage engagement element. The first rotation speed higher than the input shaft rotation speed (hereinafter referred to as the shift-down reference rotation speed ND0) corresponding to the vehicle speed when the vehicle is engaged.
A pre-stage control stage that controls the engagement force of the preceding stage engagement element is executed so as to match the shift-down target rotational speed ND1, and the engagement force of the next stage engagement element is moderated in parallel with this control. The next control stage to increase is executed, and the rotation speed of the input shaft is the downshift reference rotation speed N.
A second shift-down target rotation speed ND2 (ND0 <N which is higher than D0 and lower than the first shift-down target rotation speed ND1)
When D2 <ND1) or less, the engagement control means
The engagement force of the preceding stage engagement element is reduced, and the rotation speed of the input shaft is equal to the downshift reference rotation speed N.
A third shift-down target rotation speed ND3 (ND0 <N which is higher than D0 and lower than the second shift-down target rotation speed ND2)
When D3 <ND2) or less, the process proceeds to the next front stage control stage and the next stage control stage to minimize the engagement force of the front stage engagement element and maximize the engagement force of the next stage engagement element. The shift control device for an automatic transmission according to claim 1, wherein the shift control device is configured to perform the control.