JPH074513A - Controller for automatic transmission - Google Patents

Abstract

PURPOSE:To effectively suppress the eruption of engine revolution, speed change shock, etc., at the time of speed change by properly setting the changeover timing for a friction element. CONSTITUTION:The controller for automatic transmission is one which has a friction element such as, for example, a 2-4 brake, provided to a speed-change gear mechanism and used to change over the power transmission path thereof, and an oil pressure control circuit 60 for controlling supply/discharge of operational oil pressure with respect to this friction element. Between a 3-4 shift valve 66 for controlling supply/discharge of oil pressure with respect to the friction element and this friction element there are provided a pressure control circuit 79 for supplying to the friction element the oil pressure controlled to a specified pressure at the beginning stage of speed change operation, a line pressure circuit 76 for supplying a line pressure to the friction element at the ending stage of speed change operation, and a selection/changeover means composed of a 2-3 timing valve 78 and the like, for selecting of the circuits 79, 76 and communicating this selected circuit to the friction element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission that appropriately controls the operation timing of a friction element during gear shifting.

[0002]

2. Description of the Related Art Generally, an automatic transmission mounted on a vehicle is
By combining a torque converter and a speed change gear mechanism and selectively actuating a plurality of friction elements such as clutches and brakes, the power transmission path of the speed change gear mechanism is switched to automatically change speed. This type of automatic transmission is provided with a hydraulic control circuit that controls the supply and discharge of hydraulic pressure to and from the actuators of the friction elements.

The above hydraulic control circuit is disclosed in, for example, Japanese Patent Laid-Open No. 62-62.
As disclosed in Japanese Patent No. 246652, a pressure regulator valve for adjusting a line pressure, a manual valve for switching a range by manual operation, and a plurality of friction elements are selectively operated by switching an oil passage leading to each actuator. A shift valve and a solenoid valve that receives a control signal according to an operating state and drives each shift valve are provided.

In such an automatic transmission, the operating state of each friction element may be set to be switched by supplying the operating oil pressure to each of at least two specific friction elements during a predetermined gear shift. That is, the automatic transmission includes a 3-4 clutch that is engaged in the 3rd and 4th speeds and a 2-4 brake that is engaged in the 2nd and 4th speeds, and is in the 2-3 speed (from the 2nd speed to the 3rd speed). (When shifting to high speed), 3-
The engagement hydraulic pressure is supplied to the 4 clutch to switch the 3-4 clutch from the released state to the engaged state, and 2
The shift is executed by supplying the releasing hydraulic pressure to the -4 brake and switching the 2-4 brake from the engaged state to the released state.

[0005]

SUMMARY OF THE INVENTION As described above, in the one configured so as to switch the operating state of each specific friction element by supplying the hydraulic pressure to each of the at least two specific friction elements at the time of the predetermined gear shift, one friction element is used. If the timing at which is switched and the timing at which the other friction element is switched are not properly adjusted, smooth gear shifting cannot be performed. That is,
In the above example, if the 2-4 brake releasing operation is relatively early with respect to the 3-4 clutch engaging operation during the 2-3 gear shift, the transmission mechanism temporarily becomes in the neutral state and the engine speed is reduced. If the releasing operation of the 2-4 brake is too late, a shift shock due to a drop in rotation occurs.

Therefore, during the predetermined gear shift as described above,
It is necessary to adjust the supply timing of the operating hydraulic pressure to each friction element in order to perform a smooth gear shift, but since the hydraulic pressure supply timing to each friction element was only adjusted individually, one friction element Correspondence between the switching timing of No. 1 and the switching timing of the other frictional element is not necessarily adjusted optimally, and the above-mentioned rotation up may occur.

Therefore, in order to solve the above problem, an orifice is provided in an oil passage communicating with each actuator provided in each friction element, and bypass passages bypassing these orifices are provided so as to extend over these bypass passages. It has been practiced to install a timing valve (Japanese Patent Laid-Open No. 2-76968). With such a configuration, the timing valve and its control means adjust the supply / discharge timing of the hydraulic pressure at the time of the predetermined gear shift in combination with the action of the orifice provided in each oil passage.

However, in the control device having the above structure, it is necessary to provide a control means for controlling the operation timing of the timing valve, and the structure is complicated, and the timing of switching the friction elements is likely to deviate. There's a problem.

The present invention has been made to solve the above-mentioned problems, and effectively sets the switching timing of the friction elements to effectively prevent the engine rotation from rising during a gear shift and the occurrence of a gear shift shock. It is an object of the present invention to provide a control device for an automatic transmission that can perform the operation.

[0010]

The invention according to claim 1 is
What is claimed is: 1. A control device for an automatic transmission, comprising: a friction element that is provided in a speed change gear mechanism and switches a power transmission path thereof; and a hydraulic control circuit that controls a hydraulic pressure supplied to the friction element. A pressure adjusting circuit for supplying a hydraulic pressure adjusted to a predetermined pressure to the friction element between the shift valve for discharging and the friction element, and a line pressure for the friction element in the latter stage of the speed change. A line pressure circuit and selection switching means for selectively communicating the line pressure circuit and the pressure adjusting circuit with the friction element are provided.

According to a second aspect of the present invention, in the control device for an automatic transmission according to the first aspect, a suppressing means for suppressing the drain of the pressure adjusting circuit is provided in the latter stage of gear shifting.

According to a third aspect of the present invention, there is provided a plurality of friction elements provided in the speed change gear mechanism and switching the power transmission path thereof, and a hydraulic control circuit for controlling the hydraulic pressure supplied to these friction elements. A control device for an automatic transmission configured to supply hydraulic pressure to a plurality of friction elements at a predetermined speed to switch the operating state of each friction element, and a shift valve for supplying / discharging the hydraulic pressure to / from each friction element. , A pressure adjusting circuit for supplying a hydraulic pressure adjusted to a predetermined pressure to a specific friction element in the initial stage of gear shifting, and a line pressure for supplying a line pressure to the specific friction element in the latter stage of gear shifting. A circuit and selection switching means for selectively communicating the line pressure circuit and the pressure adjusting circuit with the friction element,
Second selection switching means for supplying hydraulic pressure to other friction elements in the latter stage of gear shift, and a drain control line for supplying hydraulic pressure for drain suppression to the pressure regulating circuit according to the operation of the second selection switching means. It is provided.

According to a fourth aspect of the present invention, in the control device for an automatic transmission according to the first aspect, a connecting line for supplying the hydraulic pressure of the pressure regulating circuit to a friction element composed of a coast clutch is provided, and the coast clutch is provided. The hydraulic pressure adjusted to a predetermined pressure by the pressure adjusting circuit during operation is supplied to the coast clutch via a connecting line.

[0014]

According to the invention described in claim 1, after the hydraulic pressure adjusted to a predetermined pressure by the pressure regulating circuit is supplied to the friction element in the initial stage of the speed change and the friction element is in the state immediately before the operation, the speed change is performed. By supplying the line pressure from the line pressure circuit to the friction element in the latter stage, the friction element shifts to the operating state.

According to the second aspect of the present invention, the drain of the pressure regulating circuit is suppressed in the latter stage of the shift when the hydraulic pressure supply circuit for the friction element is switched from the pressure regulating circuit to the line pressure circuit. As a result, it is possible to suppress the waste of the driving force of the hydraulic pump that supplies the hydraulic pressure to each part.

According to the invention described in claim 3, when the second selection switching means is activated in the latter stage of the gear shift, the pressure adjusting circuit is responsive to the hydraulic pressure supplied from the drain control line to the pressure adjusting circuit. The drain will be suppressed.

According to the invention described in claim 4, when the coast clutch is operated during a predetermined downshift, the oil pressure in the coast clutch is predetermined according to the oil pressure supplied to the coast clutch through the connecting line. After the pressure is adjusted, the coast clutch is engaged.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows an example of a mechanical structure of an automatic transmission to which the present invention is applied. The automatic transmission 10 includes a torque converter 20, a multi-stage transmission gear mechanism 30 connected to the output side thereof, and the transmission gear mechanism 3
A plurality of friction elements 41 to 46 such as clutches and brakes for switching the power transmission path of 0 and the one-way clutch 5
1 and 52.

The torque converter 20 includes a pump 22 fixed in a case 21 connected to the output shaft 1 of the engine, and a turbine which is arranged so as to face the pump 22 and is driven through hydraulic oil. 23 and the pump 2
2 and the turbine 23, and a stator 25 that increases the torque by being supported by the transmission case 11 via a one-way clutch 24.

The rotational force of the turbine 23 is transmitted to the speed change gear mechanism 30 via the turbine shaft 27. Further, the torque converter 20 is provided with a lockup clutch 26 that directly connects the input side and the output side of the torque converter 20. A pump shaft 12 penetrating the turbine shaft 27 is connected to the engine output shaft 1, and the pump shaft 12 drives an oil pump 13 mounted at the rear end of the automatic transmission. ing.

The speed change gear mechanism 30 is composed of a Ravigneaux type planetary gear device arranged on the turbine shaft 27. This planetary gear device includes a small-diameter sun gear 31 loosely fitted in a turbine shaft 27, and a turbine shaft 2 which is located behind the small-diameter sun gear 31.
A large-diameter sun gear 32 loosely fitted in 7, a plurality of short pinion gears 33 meshing with the small-diameter sun gear 31;
A long pinion gear 34 whose front half engages with the short pinion gear 33 and whose rear half engages with the large-diameter sun gear 32, a carrier 35 which rotatably supports the short pinion gear 33 and the long pinion gear 34, and an engagement with the long pinion gear 34. And a ring gear 36. The output gear 14 is connected to the ring gear 36.

A forward clutch 41 and a first one-way clutch 51 are provided in series between the turbine shaft 27 and the small-diameter sun gear 31, and a coast clutch 42 is provided in parallel with these clutches 41, 51. Has been done. In addition, the turbine shaft 27 and the carrier 3
A 3-4 clutch 43 is interposed between the 5 and 5.
A reverse clutch 44 is provided between the turbine shaft 27 and the large-diameter sun gear 32.

Between the large-diameter sun gear 32 and the reverse clutch 44, a 2-4 brake 45 which is a band brake for fixing the large-diameter sun gear 32 is provided.
Further, a second one-way clutch 52 that receives the reaction force of the carrier 35 and a low / reverse brake 46 that fixes the carrier 35 are provided in parallel between the carrier 35 and the transmission case 11.

The speed change mechanism 30 moves forward 4 by itself.
It has a gear position of one shift speed and one reverse speed, and the clutches 41 to 44 and the brakes 45 and 46 are appropriately operated based on the selection operation for selecting the range and the control according to the operating state, so that the D range 1st to 4th speed and 2 ranges
-3rd speed, 1st-2nd speed in the 1st range, and reverse speed in the R range are obtained.

Here, the relationship between the operating states of the clutches 41 to 44, the brakes 45 and 46, and the one-way clutches 51 and 52 and the shift speed will be described. First, in the first speed, while the forward clutch 41 is engaged,
The first and second one-way clutches 51 and 52 are locked, and the output rotation of the torque converter 20 is transmitted from the turbine shaft 27 to the forward clutch 41 and the first clutch.
The small-diameter sun gear 31 through the one-way clutch 51.
Entered in.

Then, with the carrier 35 fixed by the action of the second one-way clutch 52, the rotation is transmitted from the small-diameter sun gear 31 to the ring gear 36 via the short pinion gear 33 and the long pinion gear 34. As a result, the small-diameter sun gear 31 and the ring gear 36 are
Thus, the first speed state with a large reduction ratio corresponding to the ratio of the diameters of and is obtained.

Next, in the second speed, in addition to the state of the first speed, the 2-4 brake 45 is engaged, the large-diameter sun gear 32 is fixed, and the second one-way clutch 52 is in the idling state. Therefore, the rotation transmitted from the turbine shaft 27 to the small diameter sun gear 31 is transmitted to the long pinion gear 34 via the short pinion gear 33, and the long pinion gear 34 revolves on the large diameter sun gear 32. Rotates. As a result, the rotation of the ring gear 36 is accelerated by the amount of rotation of the carrier 35 as compared with the 1st speed state, and the 2nd speed state in which the reduction ratio is smaller than that in the 1st speed is obtained.

In the 3rd speed, the 2nd speed is changed to the 2nd speed.
At the same time as the -4 brake 45 is released, the 3-4 clutch 43 is engaged. Therefore, the turbine shaft 27
Is input to the small-diameter sun gear 31 via the forward clutch 41 and the first one-way clutch 51, and at the same time, the carrier 35 via the 3-4 clutch 43.
Will also be entered. As a result, the speed change gear mechanism 3
The entire 0 gear rotates integrally, and the third gear state in which the ring gear 36 rotates at the same speed as the turbine shaft 27 is obtained.

In the 4th speed, the 2-4 brake 45, which was once released in the 3rd speed, is reengaged.
Therefore, the rotation of the turbine shaft 27 is input to the carrier 35 from the 3-4 clutch 43, and the long pinion gear 34 is revolved. The large-diameter sun gear 32 meshed with the long pinion gear 34 causes the rotation of the 2-4.
Since it is fixed by the brake 45, the long pinion gear 34 revolves around the carrier 35 while revolving. As a result, the ring gear 36 meshing with the long pinion gear 34 is rotationally driven by being rotated by the rotation of the carrier 35 by the amount of rotation of the long pinion gear 34, whereby the fourth speed in the overdrive state is obtained.

Further, at the reverse speed, the reverse clutch 44 and the low reverse brake 46 are engaged,
The rotation of the turbine shaft 27 is input to the large-diameter sun gear 32, and the carrier 35 causes the body case 1 to rotate.
It is fixed at 1. Therefore, the rotation is transmitted from the large-diameter sun gear 32 via the long pinion gear 34 to the ring gear 36 via a fixed gear train, and a reduction ratio corresponding to the diameter ratio between the large-diameter sun gear 32 and the ring gear 36 is obtained. When the ring gear 36 is obtained,
Rotate in the direction opposite to 7.

Since the first one-way clutch 51 that transmits rotation at the 1st to 3rd speeds and the second one-way clutch 52 that receives a reaction force at the 1st speed idles during coasting, the engine brake operates at these gears. I'm not going to do that, but it's D range 3rd speed, 2 range 2 and 3
In the 1st speed and the 1st speed in the 1st range, the coast clutch 42 in parallel with the first one-way clutch 51 is engaged.
At the first speed in the range, the low / reverse brake 46 in parallel with the second one-way clutch 52 is engaged, so that engine braking can be obtained at these shift speeds.

Table 1 below summarizes the relationship between the operation of each of the friction elements 41 to 46 and the one-way clutches 51, 52 and the shift speed.

[0033]

[Table 1]

Main parts of the hydraulic control circuit 60 for supplying and discharging hydraulic pressure to the actuators of the friction elements 41 to 46 will be described with reference to FIG. Here, among the above actuators, the hydraulic actuator of the 2-4 brake 45 comprises a servo piston having a servo release chamber 61 and a servo apply chamber (not shown), and the hydraulic pressure is supplied only to the servo apply chamber. If the 2-4 brake 45 is engaged, otherwise, the 2-4 brake 45 is engaged.
Is configured to release. Further, the actuators of the other friction elements 41 to 44, 46 are composed of normal hydraulic pistons, and fasten the friction elements when hydraulic pressure is supplied.

The hydraulic control circuit 60 has, as main components, a pressure regulator valve 63 for adjusting the pressure of the hydraulic oil discharged from the oil pump 13 to the main line 62 to a predetermined line pressure (PL pressure), and a manual pressure regulator valve 63. Manual valve 64 for selecting the range by operation
And 1-2 shift valves (not shown) for performing hydraulic pressure supply / discharge to / from the friction elements 41 to 46 by operating according to the shift speed, and 2-3 shift valves 65 and 3-4 shift valves 66. And a valve is provided.

The manual valve 64 has an input port e through which a line pressure is introduced from the main line 62, and a first port
To fourth output ports a to d, the input port e corresponds to the first and second output ports a and b in the D range and the second range, and the first and first output ports in the first range according to the movement of the spool 62a. The three output ports a and c, and in the R range, the fourth output port d, respectively. First to fourth output lines are connected to the output ports a to d, respectively.

Further, the above 2-3, 3-4 shift valve 6
5 and 66, spools 65a and 66a are biased to the right side in the drawing by springs (not shown), and pilot ports 65b and 66b are provided on the right side of the spools 65a and 66a. The second and third pilot lines 67 and 68 branched from the first output line are connected to the pilot ports 65b and 66b of the 2-3 shift valve and 3-4 shift valves 65 and 66, respectively. In addition, the pilot line 6
7 and 68, the second and third solenoid valves 6 respectively
9, 70 are provided.

The second and third solenoid valves 69, 7
0 is pilot line 67,6 when each is ON
8 is drained to discharge the pilot pressure in the pilot ports 65b and 66b.
a, 66a on the right side of the figure, and when it is OFF, the pilot line 67, 68 to the pilot port 65
By introducing pilot pressure into b and 66b, the spools 65a and 66a are positioned on the left side of the drawing.

The second and third solenoid valves 69, 7
0 and the first solenoid valve provided in the pilot line of the 1-2 shift valve (not shown) are controls output from the control circuit based on a map preset corresponding to the vehicle speed and the throttle opening of the engine. O according to the signal
N and OFF control is performed, and each shift valve is operated accordingly, so that the friction elements 41 to 46 are engaged and disengaged so as to obtain a shift speed according to the operating state. ON, O of first to third solenoid valves
The relationship with the FF combination pattern is set as shown in Table 2 below.

[0040]

[Table 2]

Of the first to fourth output lines connected to the output ports a to d of the manual valve 62, the second output line 72 communicating with the main line 62 in the D and 2 ranges is 2-3 shifts. Guided by the valve 65, the second solenoid valve 69 is turned off (spool 65
a becomes the left position), the second output line 7
2 communicates with the 3-4 clutch line 73. This 3-4
The clutch line 73 reaches the 3-4 clutch 43 via the one-way orifice 74. Therefore, the hydraulic pressure is supplied to the 3-4 clutch 43 in the 3rd and 4th speeds of the D range and the 3rd speed of the 2nd range in which the second solenoid valve 69 is turned off.

The second solenoid valve 69 is turned on during 3-2 downshift, 4-2 downshift, 3-1 downshift, or 4-1 downshift.
Therefore, the spool 65a of the 2-3 shift valve 65 is located on the left side, so that the hydraulic pressure in the 3-4 clutch line 73 is drained. Reference numeral 75 is an accumulator that acts as a shock absorber when the 3-4 clutch operates.

The second solenoid valve 69 branches off from the 3-4 clutch line 73 and turns off (spool 64a
Is located on the left side), the branch line 73a communicating with the second output line 72 is guided to the 3-4 shift valve 66, and the third solenoid valve 70 is turned off (spool 6).
When 6a is in the left position), it is communicated with the servo release line 77 via a selection switching means including a first line 76 and a 2-3 timing valve 78 described later.
This servo release line 77 is 2-4 brake 45
Is connected to the release port 45b.

Further, the 3-4 shift valve 66 and the 2
-3 between the timing valve 78 and the pressure regulating valve 79
Is provided in parallel with the first line 76, and the hydraulic pressure adjusted to a predetermined pressure by the pressure regulating valve 79 at the initial stage of 2-3 gear shift described later is the servo release line 77. It is configured to be supplied to the release port 45b via the. That is,
The pressure adjusting valve 80 exerts the pressure adjusting function by adjusting the opening ratio of the drain port according to the throttle modulator pressure (PM pressure) supplied from the throttle modulator valve 88 described later. Is configured to.

A branch line 81, which branches from the servo release line 77, is provided on the downstream side of the 2-3 timing valve 78. The branch line 81 communicates with the coast clutch line 86 via the second selection switching means including the coast timing valve 83, the one-way orifice 84 and the ball valve 85, and reaches the coast clutch 42. On the other hand, one end portion 80b of the spool 80a of the pressure regulating valve 80 is branched to the branch line 81 from the downstream side of the coast timing valve 83.
A drain control line 87 communicating with the above is provided.

Further, the hydraulic pressure control circuit 60 has a throttle modulator valve 88 for controlling the pressure regulator valve 63 by applying a throttle modulator pressure (PM pressure) to the pressure increasing port of the pressure regulator valve 63. It is provided. The throttle modulator valve 88 is configured to generate a throttle modulator pressure according to the duty ratio of the duty solenoid valve. The duty ratio is set according to the throttle opening of the engine,
Throttle modulator pressure corresponding to this throttle opening is applied to the pressure regulator valve 63.

In addition to the above configuration, the hydraulic pressure control circuit 60 has a release port 45b for the 3-4 clutch 43 and the 2-4 brake 45 at the time of 2-3 upshifting.
A bypass valve 89 for adjusting the operation timing of the 3-4 clutch 43 when the hydraulic pressures are respectively supplied to and to engage the 3-4 clutch 43 and release the 2-4 brake 45.
Is provided. This bypass valve 89 is 3-4
It is provided in a bypass line 90 that bypasses the one-way orifice 74 provided in the clutch line 73. The oil pressure on the downstream side of the one-way orifice 73 is introduced into one end of the spool 89a, and the other end of the spool 89a is introduced. , Throttle modulator valve 8
A throttle modulator pressure (PM pressure) of 8 is introduced.

The bypass line 90 is cut off when the hydraulic pressure in the 3-4 clutch line 73 rises above a predetermined value and the spool 89a of the bypass valve 89 moves to the left. Therefore, 3-
When the 4-clutch 43 is switched from the disengaged state to the engaged state, the hydraulic pressure is quickly supplied by the bypass line 90 at the start of the hydraulic pressure supply to the 3-4 clutch 43. The supply of the hydraulic pressure is slowed by the orifice 74, and thus the engagement timing of the 3-4 clutch 43 at the time of the 2-3 shift-up shift is adjusted.

A spool 78a of the 2-3 timing valve 78 provided on the servo release line 77 is also provided.
A line 91 communicating with the 3-4 clutch line 73 is connected to one end portion 78b of the above, and a throttle modulator pressure (PM pressure) is introduced into the other end portion 78c.
Then, either the first line 76 or the second line 79 is actuated by the servo release line 77 by the action of the control oil pressure and the throttle modulator pressure, which are the oil pressure in the 3-4 clutch line 73 introduced through the line 91. And the servo release pressure is adjusted.

That is, the above 3-4 clutch line 73
In the initial stage of 2-3 gear shift in which the hydraulic pressure inside is low, the spool 78a of the 2-3 timing valve 78 is at the one end portion 78b side (left side) in accordance with the throttle modulator pressure.
The second line 79 is located at the servo release line 77.
The hydraulic pressure adjusted to a predetermined pressure by the pressure adjusting valve 80 is supplied to the servo release chamber 45a via the second line 79 by communicating with the servo release chamber 45a.

When the hydraulic pressure in the 3-4 clutch line 73 becomes high in the latter stage of the 2-3 gear shift, the spool 7 of the 2-3 timing valve 78 is corresponding to the hydraulic pressure.
8a is displaced to the other end 78c side (right side), and the first line 7
By connecting 6 to the servo release line 77,
The high line pressure in the second output line 72 is supplied to the servo release chamber 45a via the first line 76.

When the line pressure is supplied into the servo release chamber 45a and the 2-4 brake 45 is released, the hydraulic pressure in the servo release line 77 is transferred to the coast clutch line 86 via the branch line 81. When the coast clutch 42 is supplied, the coast clutch 42 enters the engaged state. After that, the hydraulic pressure in the branch line 81 is changed to the drain control line 8
One end 8 of the spool 80a of the pressure regulating valve 80 via
By being supplied to 0b, the operation of the pressure regulating valve 80 is prohibited and the hydraulic drain is stopped.

As described above, the 3-4 shift valve 66 which controls the supply and discharge of the hydraulic pressure to the servo release line 77 at the time of the 2-3 shift, and the 2-3 timing valve which controls the timing of the hydraulic pressure supply to the servo release line 77. 78 and the first line 76 for supplying line pressure
And a pressure regulating circuit consisting of a second line 79 provided with a pressure regulating valve 80 are provided in parallel, and a predetermined pressure is regulated by the pressure regulating circuit 79 having the pressure regulating valve 80 at the initial stage of 2-3 gear shift. After the supplied hydraulic pressure is supplied to the servo release line 77, the line pressure circuit 76 is supplied from the line pressure circuit 76 to the servo release circuit 77 by the selection switching means composed of 2-3 timing valves in the latter stage of the shift. Since it is configured, a smooth gear shift can be performed without causing a gear shift shock.

That is, as shown in FIG. 3, in the conventional example in which the servo release pressure is increased from 0 to the engagement pressure at a time T2 when a predetermined time has elapsed from the time T1 of shifting, the above-mentioned 2 -4 brake 45
Cannot be moved to the released state promptly,
As a result, it was not possible to prevent the occurrence of a retraction shock in which the drop in the acceleration (G waveform) of the vehicle is temporarily increased.

On the other hand, as shown in FIG. 4, the hydraulic pressure adjusted to the set pressure immediately before the release of the 2-4 brake 45 by the pressure control valve 80 of the pressure control circuit at the shift start time T1 is used as the servo release pressure. After the action, the above 3-4
When the hydraulic pressure of a predetermined pressure is supplied from the clutch line 73 to the 3-4 clutch 43, the engagement time T3 of the 3-4 clutch 43
According to the present invention configured to supply the line pressure to the servo release chamber 45b by connecting the line pressure circuit including the first line 76 to the servo release line 77, the servo release pressure can be quickly applied. It is possible to prevent the occurrence of the pull-in shock because it can be raised up to.

In the above embodiment, the D range 2-3
In the hydraulic control circuit 60 including the coast clutch 42 that operates together with the 2-4 brake 45 at the time of shifting,
As shown in FIG. 2, the branch line 81 for supplying the hydraulic pressure to the coast clutch 42 is provided with the drain control means of the pressure control valve 80, which includes the drain control line 87 communicating with the one end 80a of the pressure control valve 80. In the latter stage of gear shifting during the 2-3 gear shift, the pressure regulating valve 80 is responsive to the hydraulic pressure supplied from the drain control means when the second selection switching means including the coast timing valve 83 is operated.
Is fixed to the drain prohibited state.

According to the above configuration, the drain of the pressure regulating valve 80 is reliably prevented from being continued when it is unnecessary without providing a solenoid valve or the like, and the driving force of the oil pump 13 is wasted with a simple configuration. Can be effectively suppressed.

Instead of the drain control line 87, as shown in FIG. 5, the spool 80 of the pressure regulating valve 80 is used.
A drain control line 93 having a fifth solenoid valve 92 is provided at one end 80b of a, and the fifth solenoid valve 92 is turned off at a later stage of the 2-3 shift, thereby making the pressure regulating valve 80 May be fixed to the drain prohibited state.

Further, in the example shown in FIG. 5, the third line 94 for connecting the second line 79 located downstream of the pressure regulating valve 80 and the coast timing valve 83 is provided. Then, the 2-4 brake 45 is shifted from the engaged state to the released state, and the coast clutch 42
During a 4-3 gear shift that shifts from the released state to the engaged state,
The hydraulic pressure in the second line 79 is supplied to the coast timing valve 83 via the third line 94, and the operating state of the pressure regulating valve 80 provided in the second line 79 is controlled by the fifth solenoid 92. Thus, the coasting down shock at the time of engaging the coast clutch 42 is effectively prevented.

That is, in the conventional example shown in FIG. 6, a predetermined time has elapsed from the shift start time Ta and the operation time T of the coast clutch 42 at which the servo release pressure has risen to the set pressure.
In b, since the coast clutch 42 is configured to shift to the engaged state at once by starting the supply of the line pressure to the coast clutch 42, the coasting down shock is prevented from occurring when the coast clutch 42 is engaged. You can do things you couldn't do.

On the other hand, in the above embodiment, as shown in FIG. 7, the servo release line 77 is used during the 4-3 shift.
The hydraulic pressure supplied to the servo release chamber 45b via the hydraulic pressure rises to the operating pressure and the 2-4 brake is moved to the released state at the operating time point Tb of the coast clutch 42, which is adjusted to a predetermined pressure by the pressure regulating valve 80. The hydraulic pressure in the second line 79 is transferred to the coast clutch line 8 via the third line 94.
6, after the coast pressure rises to the predetermined pressure, the line pressure introduced into the second line 79 is applied to the coast clutch at the gear shift end time Tc when the fifth solenoid 92 is turned off. The coast clutch 42 is supplied to the line 86 and shifts to the engaged state.

Further, in the control hydraulic circuit 60 provided with the fifth solenoid 92 for controlling the operating state of the pressure regulating valve 80, as shown in FIG. -4 control valve 95
With this 3-4 control valve 95
And a connection line formed of a fourth line 96 that connects the drain control line 93 having the fifth solenoid 92 to each other.

In this case, as shown in Table 3 below,
In the 3-4 clutch 43 through the 3-4 control valve 95, an intermediate shift region is provided in which the fifth solenoid 92 is temporarily turned on during the 4-1 shift, the 3-1 shift, or the 2-1 shift. By arranging to discharge the hydraulic pressure, it is possible to improve the shift responsiveness during the downshift and effectively prevent the occurrence of shift shock.

[0064]

[Table 3]

[0065]

As described above, according to the present invention, between the shift valve for controlling the supply and discharge of the hydraulic pressure to the friction element at the time of shifting and the friction element, the hydraulic pressure adjusted to the predetermined pressure in the initial stage of the shifting is provided. Is provided in parallel with a line pressure circuit for supplying a line pressure to the friction element in the latter stage of gear shift, and both circuits are selectively communicated with the friction element by the selection switching means. With this configuration, the line pressure is applied to the friction element via the line pressure circuit at a predetermined time in a state in which the hydraulic pressure adjusted to the set pressure just before the operation by the pressure adjusting circuit is applied to the friction element at the start of gear shifting. By supplying, the friction element can be activated early. Therefore, there is an advantage that it is possible to effectively prevent the occurrence of a pull-in shock in which the acceleration of the vehicle body sharply decreases at the time of shifting, and it is possible to perform a smooth shift without causing a shift shock.

Further, when the drain restraining means for restraining the drain of the pressure regulating circuit is provided in the latter stage of the shift, the line communicating with the friction element is switched from the pressure regulating circuit to the line pressure circuit. Therefore, it is possible to effectively suppress the waste of the driving force of the oil pump, which is caused by the above-mentioned pressure adjusting circuit being kept in the operating state and the drain being continued.

In particular, in a control device for an automatic transmission configured to supply hydraulic pressure to a plurality of friction elements at a predetermined speed change, a predetermined pressure of hydraulic pressure is supplied to a specific friction element such as a 2-4 brake. Operation of the second selection switching means including a coast timing valve for controlling the hydraulic pressure supply to another friction element such as a coast clutch, which is provided with a pressure regulating circuit and a drain control line for suppressing drainage of the pressure regulating circuit. Accordingly, in the case where the oil pressure for drain suppression is supplied to the pressure adjusting circuit via the drain control line in the latter stage of gear shift, the oil pump of a simple structure can be provided without providing a solenoid valve or the like. It is possible to prevent the driving force from being consumed.

Further, a connecting line for supplying the oil pressure of the pressure adjusting circuit to the coast clutch is provided, and when the coast clutch operates, the oil pressure of the predetermined pressure adjusted by the pressure adjusting circuit is supplied to the coast clutch. In this case, it is possible to effectively prevent the occurrence of coasting down shock during shift down gear shifting.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram showing an overall structure of an automatic transmission to which a control device according to the present invention is applied.

FIG. 2 is a circuit configuration diagram showing a main part of the control device.

FIG. 3 is a time chart showing a hydraulic pressure control state during 2-3 shifts in a conventional example.

FIG. 4 is a time chart showing a hydraulic pressure control state during 2-3 shifts in the embodiment of the present invention.

FIG. 5 is a circuit configuration diagram showing another embodiment of the control device.

FIG. 6 is a time chart showing a control state of hydraulic pressure at the time of 4-3 shift in the conventional example.

FIG. 7 is a time chart showing a hydraulic pressure control state during a 4-3 shift in the embodiment shown in FIG.

FIG. 8 is a circuit configuration diagram showing yet another embodiment of the control device.

[Explanation of symbols]

 10 Automatic Transmission 30 Shift Gear Mechanism 42 Coast Clutch (Friction Element) 43 3-4 Clutch (Friction Element) 45 2-4 Brake (Friction Element) 60 Hydraulic Control Circuit 65 2-3 Shift Valve 66 3-4 Shift Valve 78 2-3 Timing valve (selection switching means) 76 First line (line pressure circuit) 79 Pressure regulating valve 80 Second line (pressure regulation circuit) 83 Coast timing valve (second selection switching means) 87, 93 Drain control line ( Drain suppression means) 96 4th line (connection line)

Claims (4)

[Claims] 1. A control device for an automatic transmission, comprising: a friction element provided in a speed change gear mechanism for switching a power transmission path thereof; and a hydraulic control circuit for controlling a hydraulic pressure supplied to the friction element. Between the shift valve for supplying / discharging hydraulic pressure to / from the element and the friction element, a pressure adjusting circuit for supplying the hydraulic pressure adjusted to a predetermined pressure to the friction element in the initial stage of gear shift, and the line pressure in the latter stage of gear shift are described above. A control device for an automatic transmission, comprising: a line pressure circuit for supplying the friction element; and a selection switching means for selectively communicating the line pressure circuit and the pressure adjusting circuit with the friction element. 2. The control device for an automatic transmission according to claim 1, further comprising a suppressing means for suppressing drainage of the pressure adjusting circuit in the latter stage of gear shifting. 3. A plurality of friction elements provided in a speed change gear mechanism and switching a power transmission path thereof, and a hydraulic control circuit controlling a hydraulic pressure supplied to these friction elements, wherein a plurality of friction elements are provided at a predetermined speed change. A control device for an automatic transmission configured to supply hydraulic pressure to an element to switch the operating state of each friction element, comprising a shift valve for supplying / discharging hydraulic pressure to / from each friction element and each friction element. In the meantime, a pressure adjusting circuit that supplies the hydraulic pressure adjusted to a predetermined pressure to a specific friction element in the initial stage of gear shifting, a line pressure circuit that supplies a line pressure to the specific friction element in the latter stage of gear shifting, and the line pressure A selection switching means for selectively connecting the circuit and the pressure regulating circuit to the friction element, and a second selection switching means for supplying hydraulic pressure to another friction element in the latter stage of gear shifting; and the second selection switching means. To the operation of Accordingly, a drain control line for supplying hydraulic pressure for drain suppression to the pressure adjusting circuit is provided. 4. A connecting line for supplying the hydraulic pressure of the pressure regulating circuit to a friction element composed of a coast clutch is provided, and the hydraulic pressure adjusted to a predetermined pressure by the pressure regulating circuit when the coast clutch is operated is connected through the connecting line. The control device for an automatic transmission according to claim 1, wherein the control device is configured to supply the power to a coast clutch.