JPH07158728A - Gear ratio control device of automatic transmission - Google Patents

Abstract

PURPOSE:To make proper gear ratio control in accordance with the stamping motion for an accel. pedal with an automatic transmission equipped with a supply/exhaust adjusting means which is to adjust the supply/exhaust timing for the oil pressure to be supplied and exhausted through an oil hydraulic circuit for engagement and disengagement of a friction element. CONSTITUTION:An automatic transmission has a friction element, for example a 2-4 brake, and an accum. cut valve 73 is installed between a line 117 leading to an apply port 45b provide at a servo piston 45a of this friction element and an accumulator 74. At the time for example of 4-3 gear shifting, the 2-4 brake is disengaged by exhausting the oil pressure from the apply port 45b. Therein the stamping speed of an accel. pedal is sensed by a sensor to serve for controlling the valve 73 with a controller. That is, the valve 73 is set in the position in which the accumulator 74 and line 117 are in connection when the stamping speed remains small. When it is large, the valve 73 is switched to the position in which the accumulator 74 is shut off from the line 117.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed change control device for an automatic transmission, and more particularly to a hydraulic circuit for supplying / discharging the engaging hydraulic pressure to / from a predetermined friction element for adjusting the timing of supplying / discharging the engaging hydraulic pressure of an orifice or an accumulator. The present invention relates to control at the time of a shift in which the friction element is released at the time of downshifting to a predetermined shift speed in an automatic transmission provided with a hydraulic pressure supply / discharge adjusting means for use.

[0002]

2. Description of the Related Art Generally, an automatic transmission mounted on an automobile is a combination of a torque converter and a speed change mechanism, and a power transmission path of the speed change mechanism is switched by selectively engaging a plurality of friction elements such as clutches and brakes. , Which is configured to automatically shift to a predetermined shift stage, and is provided with a hydraulic control circuit for selectively engaging these friction elements. In this type of automatic transmission,
There is one in which a gear stage is downshifted by releasing a predetermined friction element during a predetermined gear shift. For example, in an automatic transmission that is capable of automatic transmissions of 1st to 4th gears, if a predetermined friction element is configured to be engaged at 2nd gears and 4th gears, downshifting from 4th gears to 3rd gears is possible. When shifting, the predetermined friction element is released. In that case, the actuator of the predetermined friction element has a fastening chamber and a release chamber, and is in a fastening state when the hydraulic pressure is supplied only to the fastening chamber, and when the hydraulic pressure is not supplied to both chambers and In some cases, a chamber configured to be in a released state when hydraulic pressure is supplied is used. According to this structure, when the engagement hydraulic pressure is discharged from the engagement chamber during the 4-3 downshift, for example, the friction element is released and the engagement element that achieves the third speed is provided. When the gears are engaged, the shift speed is switched from the 4th speed to the 3rd speed.

By the way, in this type of automatic transmission, it is important that the timing of supplying / discharging the hydraulic pressure to / from the friction element is appropriately adjusted. If an unpleasant shock is generated at the time of release, and conversely the supply and discharge of the hydraulic pressure is too slow, the shift operation time becomes unduly long and the shift feeling deteriorates.

To address the problem of the hydraulic pressure supply / discharge timing with respect to the friction elements at the time of gear shifting, for example, an oil passage communicating with each friction element is provided with an orifice having an appropriately set diameter to supply / discharge the hydraulic pressure. Is adjusted, or an orifice and an accumulator are used together to form a so-called shelf pressure state in which the pressure change is gentle, and the timing of hydraulic pressure supply and discharge is adjusted.

Further, for example, Japanese Examined Patent Publication No. 58-29420.
As disclosed in Japanese Patent Publication, a switching valve (shift timing valve) for connecting and disconnecting the connection between an oil passage leading to a friction element and an accumulator is provided, and a hydraulic pressure is gently supplied when the friction element is engaged. On the other hand, there is a structure in which the hydraulic pressure is quickly discharged when the friction element is released.

[0006]

By the way, the shift control in the automatic transmission of this type is provided with a shift map in which, for example, the vehicle speed and the engine load are set as parameters, and the operation state (vehicle speed and engine load) is the above-mentioned shift. When the gear shift line forming the map is passed, the gears are up-shifted or up-shifted by switching the engagement state of the friction elements. As a form of down-shift, there is a so-called torque demand shift. This is configured to downshift the shift stage when the engine load passes through the shift line for downshift shifting due to the driver's depression operation of the accelerator pedal. Therefore, gear change control having different characteristics is required between when the vehicle is rapidly stepped on and when it is slowly stepped on.

That is, since the driver has a clear intention to accelerate when the accelerator pedal is rapidly depressed, for example, at the time of overtaking acceleration, a shift control with better responsiveness than suppression of shock is required. It On the other hand, the gradual depression of the accelerator pedal, for example, when driving in the flow of a car, or in response to an increase in engine load,
Since it is often performed unconsciously in the middle, smooth shift control with less shock is required.

In the above example, assuming that the accumulator is connected to the engaging oil passage of the predetermined friction element that is released during the 4-3 downshift, the action of the accumulator causes the operation of discharging the engaging hydraulic pressure. Due to the delay, it is not possible to sufficiently satisfy the demand for sudden depression.

To this end, by applying the conventional technique described in the above publication, a switching valve for connecting and disconnecting the accumulator and the oil passage is installed to disconnect the oil passage when the friction element is released. It is possible to configure In this case, it is expected that the predetermined frictional element will be released early after the start of the shift control, and the above problems at the time of sudden depression will be solved. Inconvenience may occur.

That is, at the time of gentle depression, there may be a time lag from the start of the depression operation of the accelerator pedal until the driving state passes through the shift line. In such a case, acceleration at the 4th speed is required. After the state continues for a while, the predetermined friction element is released rapidly, which causes the driver to feel an uncomfortable shock. In that case, 3
If the fastening element that realizes the high speed is not engaged, not only the acceleration force decreases and the driver feels a kind of pull-in, but especially when the fastening element that realizes the third speed is a one-way clutch, A new shock will be generated when the clutch is engaged.

Even if the release hydraulic pressure is supplied to the predetermined friction element during the 4-3 downshift, the same problem as described above will still occur when the pedal is gently depressed.

According to the present invention, a hydraulic circuit for supplying / discharging the engaging hydraulic pressure to / from a predetermined friction element is provided with an engaging hydraulic pressure supply / discharge adjusting means for adjusting the timing of supplying / discharging the engaging hydraulic pressure such as an orifice or an accumulator. It is an object of the present invention to deal with the above-mentioned problem in an aircraft, and to perform an appropriate shift control according to a depression operation of an accelerator pedal by a driver.

[0013]

That is, the invention according to claim 1 of the present application (hereinafter referred to as the first invention) is a fastening hydraulic pressure supply / discharge means for supplying / discharging a fastening hydraulic pressure to / from a predetermined friction element, and the supply / discharging means. A fastening hydraulic pressure supply / discharge adjusting means for adjusting the timing of supplying / discharging the fastening hydraulic pressure by the discharging means is provided, and the predetermined frictional element is released during downshifting to a predetermined shift speed. In the automatic transmission, a switching means for switching the engagement hydraulic pressure supply / discharge adjusting means between a state in which the supply / discharge timing of the engaging hydraulic pressure can be adjusted and a state in which the adjusting operation of the timing is suppressed, and an accelerator pedal depression speed. When the accelerator pedal depression speed detected by the depression speed detecting means is low at the time of downshifting to the predetermined shift speed, The switching means is set to a state in which the timing for supplying and discharging the fastening hydraulic pressure by the fastening hydraulic pressure supply and discharge adjusting means can be adjusted, and when the stepping speed is high, the switching means is set to the fastening hydraulic pressure by the fastening hydraulic pressure supply and discharge adjusting means. And a control means for switching to a state in which the adjustment operation of the supply / discharge timing is suppressed.

The invention according to claim 2 of the present application (hereinafter,
In a second invention), the fastening hydraulic pressure supply / discharge adjusting means in the first invention is constituted by an accumulator connected to a fastening oil passage leading to a predetermined friction element, and the switching means is fastened to the accumulator. It is composed of a switching valve that switches between a position where the oil passage is connected and a position where the connection state between the two is cut off, and the control means is the stepping speed detection means at the time of downshifting to the predetermined gear. When the detected pedaling speed of the accelerator pedal is low, the switching valve is set to a position where the accumulator and the connecting oil passage are connected, and when the pressing speed is high, the switching valve is connected to the accumulator and the connecting oil passage. It is characterized in that it is configured so as to switch to a position where it is cut off.

The invention according to claim 3 of the present application (hereinafter referred to as the third invention) is a one-way clutch when the predetermined friction element is disengaged at the predetermined shift speed which is the object of the first and second inventions. It is characterized in that it is a gear stage that is achieved by the engagement of.

Further, the invention according to claim 4 of the present application (hereinafter referred to as the fourth invention) is characterized in that the switching valve in the second invention is operated by the operation of a solenoid valve.

In the invention according to claim 5 of the present application (hereinafter referred to as the fifth invention), an orifice is provided in the engaging oil passage of the predetermined friction element, and a bypass valve that bypasses this orifice is provided. In the configuration, a solenoid valve for controlling the bypass valve is also used as the solenoid valve in the fourth invention.

On the other hand, the invention according to claim 6 of the present application (hereinafter,
A sixth invention) includes a fastening chamber and a release chamber, is provided with a predetermined friction element that is in a fastening state when hydraulic pressure is supplied only to the fastening chamber, and releases the friction element from the release chamber. Release hydraulic pressure supply / discharge means for supplying / discharging hydraulic pressure, fastening hydraulic pressure supply / discharge means for similarly supplying / discharging fastening hydraulic pressure to / from the fastening chamber, and fastening for adjusting the timing of supplying / discharging the fastening hydraulic pressure by the supply / discharge means An automatic transmission, which is provided with a hydraulic pressure supply / discharge adjusting means and is configured to release the friction element at the time of downshifting to a predetermined shift stage, detects a stepping speed of an accelerator pedal. And a releasing hydraulic pressure by the releasing hydraulic pressure supply / discharge means when the accelerator pedal depressing speed detected by the depressing speed detecting means is low during downshifting to the predetermined shift speed. The fastening hydraulic pressure supply / discharge means performs the fastening hydraulic pressure discharge operation while the supply operation is stopped, and the release hydraulic pressure supply / discharge means performs the release hydraulic pressure supply operation when the stepping speed is high. A control means is provided.

[0019]

According to the above construction, in any of the first to sixth aspects of the invention, the fastening hydraulic pressure supply / discharge means for supplying / discharging the fastening hydraulic pressure to / from the predetermined friction element and the supply / discharging of the fastening hydraulic pressure by the supply / discharge means. Since the fastening hydraulic pressure supply / discharge adjusting means for adjusting the drain timing is provided, the fastening shock is alleviated when the friction element is fastened by the fastening hydraulic pressure supply.

According to the first to fifth aspects of the invention, the engagement hydraulic pressure supply / discharge adjusting means is provided in a state in which the engagement hydraulic pressure supply / discharge timing can be adjusted and in a state in which the timing adjustment operation is suppressed. A switching means for switching is provided, and when the depression speed of the accelerator pedal is low, this switching means is set in a state in which the supply / discharge timing of the engaging hydraulic pressure can be adjusted by the engaging hydraulic pressure supply / discharge adjusting means. At the time of downshifting to the predetermined shift stage in which the friction element is released, the engagement hydraulic pressure is gently discharged,
When the accelerator pedal is gently depressed, a smooth gear shift operation with less shock is performed.

On the other hand, when the accelerator pedal is stepped on at a high speed, the switching means is switched to a state in which the operation for adjusting the supply / discharge timing of the engaging hydraulic pressure by the engaging hydraulic pressure supply / discharge adjusting means is suppressed. The engaging hydraulic pressure for is rapidly exhausted, and the responsiveness of the shift at the time of sudden depression is also secured.

Further, according to the second aspect of the invention, the above-mentioned action is obtained by connecting the accumulator and the fastening oil passage to each other in a position where the accumulator is connected to the fastening oil passage leading to the predetermined friction element. It will be realized by operating the switching valve that switches the connection state of 1 to the position where it is cut off.

Further, according to the third invention, the above-mentioned operation is
Since it is obtained at the time of downshifting to the shift stage that is achieved by engaging the one-way clutch when releasing the predetermined frictional element, the shift shock particularly at the time of gentle depression is effectively suppressed.

Further, according to the fourth aspect of the invention, since the switching valve which constitutes the switching means of the second aspect of the invention is configured to operate by the operation of the solenoid valve, the exhaust pressure of the engaging hydraulic pressure to the friction element is discharged. Since it can be performed at an optimum timing by electrical control, and particularly according to the fifth aspect of the invention, a solenoid valve for a bypass valve is used as the solenoid valve, so that the control at the time of discharging the hydraulic pressure is performed. The solenoid valve will be effectively used.

On the other hand, according to the sixth aspect of the invention, when the predetermined friction element is a friction element which has the engagement chamber and the release chamber and is in the engagement state when the hydraulic pressure is supplied only to the engagement chamber, When the accelerator pedal depressing speed is low, the engaging hydraulic pressure supplying / discharging means performs the engaging hydraulic pressure discharging operation while the releasing hydraulic pressure supplying / discharging means stops the releasing hydraulic pressure supply operation. When the value is large, the releasing hydraulic pressure supply / discharge means is caused to perform the releasing hydraulic pressure supply operation, so that the same operation as the first aspect of the invention can be obtained.

[0026]

EXAMPLES Examples of the present invention will be described below.

First, the mechanical structure of the automatic transmission 10 according to this embodiment will be described with reference to FIG.
Is a torque converter 20 as a main component,
Transmission mechanism 30 driven by the output of the converter 20
And a plurality of friction elements 41 to 46 such as clutches and brakes for switching the power transmission path of the mechanism 30 and one-way clutches 51 and 52, by which the D, S, L and R ranges as a travel range are provided. And 1 to 4 speeds in the D range, 1 to 3 speeds in the S range, and 1 in the L range
You can get 2nd speed.

The torque converter 20 is a pump 2 fixed in a case 21 connected to the engine output shaft 1.
2 and the pump 22 disposed so as to face the pump 22.
A turbine 23 driven by hydraulic oil by means of a hydraulic fluid, and a stator 25 interposed between the pump 22 and the turbine 23 and supported by the transmission case 11 via a one-way clutch 24 to perform a torque increasing action. , Case 2 above
1 and the turbine 23, and is constituted by a lockup clutch 26 that directly connects the engine output shaft 1 and the turbine 23 via the case 21. The rotation of the turbine 23 is output to the transmission mechanism 30 side via the turbine shaft 27.

A pump shaft 12 penetrating the turbine shaft 27 is connected to the engine output shaft 1. The shaft 12 drives an oil pump 13 provided at the end of the transmission 10 on the side opposite to the engine. It is supposed to be done.

On the other hand, the transmission mechanism 30 is composed of a Ravigneaux type planetary gear device, and the turbine shaft 27
Small-diameter small sun gear 31 loosely fitted adjacent to the upper side
And a large diameter large sun gear 32 and a plurality of short pinion gears 33 meshed with the small sun gear 31.
And a long pinion gear 34 that is meshed over the short pinion gear 33 and the large sun gear 32.
A carrier 35 that rotatably supports the long pinion gear 34 and the short pinion gear 33, and a ring gear 36 meshed with the long pinion gear 34.

A forward clutch 41 and a first one-way clutch 51 are provided in series between the turbine shaft 27 and the small sun gear 31, and a coast clutch 42 is arranged in parallel with these clutches 41 and 51. The turbine shaft 2 is installed
A 3-4 clutch 43 is interposed between 7 and the carrier 35, and a reverse clutch 44 is interposed between the turbine shaft 27 and the large sun gear 32.

Between the large sun gear 32 and the reverse clutch 44, a 2-4 brake 45, which is a band brake for fixing the large sun gear 32, is provided, and the carrier 35 and the transmission case 11 are connected to each other. 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 them. The ring gear 36 is connected to the output gear 14, and the rotation is transmitted from the output gear 14 to the left and right wheels (not shown) via a differential device.

Here, the friction elements 41 to 46 such as the above-mentioned clutches and brakes and the one-way clutches 51 and 52.
Table 1 below summarizes the relationship between the operating state and the gear position.

[0034]

[Table 1] Next, referring to FIG. 2, a hydraulic control circuit 60 that supplies and discharges hydraulic pressure to and from the actuators of the friction elements 41 to 46 will be described. Here, of the above actuators,
The hydraulic actuator 45a of the 2-4 brake 45, which is a band brake, is composed of a servo piston having an apply port 45b and a release port 45c, and when hydraulic pressure is supplied only to the apply port 45b, 2-
When the 4 brake 45 is engaged and no oil pressure is supplied to both ports 45b and 45c,
2-4 Brake 4 when hydraulic pressure is supplied to both c
5 is released. The actuators of the other friction elements 41 to 44, 46 are composed of ordinary hydraulic pistons, and fasten the friction elements when hydraulic pressure is supplied.

The hydraulic control circuit 60 has, as main components, a regulator valve 61 for adjusting the pressure of the hydraulic oil discharged from the oil pump 13 shown in FIG. 1 to the main line 110 to a predetermined line pressure, and a manual operation. A manual valve 62 for selecting a range by means of each of the friction elements (actuators) 41 to 4 which operates in accordance with a gear position.
First, second, and third shift valves 63, 64, and 65 for supplying and discharging hydraulic pressure to and from the engine 6 are provided.

The manual valve 62 includes D, S, L
Each forward range, R range, N range, and P range can be set. In the forward range, the main line 110 is connected to the forward line 111, and in the R range, it is connected to the backward line 112. It has become.

The first, second, and third shift valves 63, 64, 65 each have a control port 63 at one end.
a, 64a, 65a are provided. And the first,
Control ports 63a, 6 of the second shift valves 63, 64
4a is connected to the first and second control source pressure lines 113 and 114 respectively branched from the forward line 111, and the control port 65a of the third shift valve 65 is connected to the reducer from the main line 110. The third control source pressure line 115 guided through the single valve 66 is connected, and these control source pressure lines 113, 1 are connected.
14 and 115, the first, second, and third for shifting, respectively.
ON-OFF solenoid valves 67, 68, 69 are provided.

Of these, the first and second ON-OFF solenoid valves 67 and 68 discharge the control pressures of the corresponding control ports 63a and 64a when they are ON, and the first and second shift valves 63 and 64. Of the control port 63a, 64 when the spool of the
A control pressure is introduced from the first and second control source pressure lines 113 and 114 to a, and the spool is positioned on the right side against the biasing force of the spring. Further, when the third ON-OFF solenoid valve 69 is ON, the third control source pressure line 115 is shut off and the control pressure of the control port 65a of the third shift valve 65 is discharged, so that the spool of the valve 65 is closed. It is located on the right side in the drawing, and when it is off, a control pressure is introduced from the third control source pressure line 115 to the control port 65a to position the spool on the left side against the biasing force of the spring. .

Here, these ON-OFF solenoid valves 67 to 69 are turned on based on a map preset according to the vehicle speed of the vehicle and the throttle opening degree of the engine in response to a signal from a controller described later. O
FF control is performed, and accordingly, each shift valve 63-65
The position of the spool of the friction elements 41 to 46 is changed.
By switching the oil passage leading to, the friction elements 41 to 46 are fastened in the combinations shown in Table 1 above, whereby the shift speed can be switched according to the operating state. In that case, each shift stage in the forward range of D, S, L and each ON-OFF solenoid valve 6
The relationship with the ON / OFF combination pattern (solenoid pattern) of 7 to 69 is set as shown in Table 2 below.

[0040]

[Table 2] On the other hand, when the manual valve 62 is set to each forward range of D, S, and L, a line 116 is branched from the forward line 111 that communicates with the main line 110, and the line 116 serves as a forward clutch line.
One-way orifice 70 and ND accumulator 7
It is guided to the forward clutch 41 via 1. Therefore, in the D, S, and L ranges, the forward clutch 4
1 will always be concluded.

Further, the forward line 111 is guided to the first shift valve 63, the first ON-OFF solenoid valve 67 is turned on, and when the spool of the shift valve 63 is positioned on the left side, the forward apply line 117 is fed to the servo apply line 117. Servo piston 45a communicating with each other through the orifice 72
To the Apply port 45b. Therefore, the first ON
-OFF When the solenoid valve 67 is ON, that is, 2nd, 3rd and 4th speeds in the D range, 2nd and 3rd speeds in the S range and L
At the second speed in the range, the operating pressure (servo apply pressure) is introduced to the apply port 45b, and the release port 45b
The 2-4 brake 45 is engaged when the operating pressure (servo release pressure) is not introduced to c.

The servo apply line 117 is provided with a 1-2 accumulator 74 via a line 118 branched from the line 117 on the downstream side of the orifice 72 and an accumulation cut valve 73 installed on the line 118. It is connected.

The forward line 111 is also guided to the second shift valve 64, the second ON-OFF solenoid valve 68 is OFF, and the spool of the second shift valve 64 is located on the right side, the 3-4 clutch line 119. Communicate with. This line 119 reaches the 3-4 clutch 43 via the 3-4 control valve 75. Therefore, the second ON-OFF solenoid valve 68 is turned off.
, That is, 3rd and 4th speed of D range and 3rd of S range
The 3-4 clutch 43 is engaged at high speed.

Further, the above 3-4 clutch line 119
The line 120 branched from is led to the third shift valve 65, and the third ON-OFF solenoid valve 69 is turned off.
At F, when the spool of the shift valve 65 is located on the left side, it communicates with the servo release line 121 that communicates with the release port 45c of the servo piston 45a. Therefore, the second and third ON-OFF solenoid valves 68,
When both 69 are OFF, that is, in the 3rd speed of the D range and the 3rd speed of the S range, the servo release pressure is introduced into the release port 45c of the servo piston 45a, and the 2-4 brake 45 is released.

The forward line 111 is also guided to the third shift valve 65, the third ON-OFF solenoid valve 69 is OFF, and the coast clutch line 12 is when the spool of the shift valve 65 is located on the left side.
Connect to 2. This coast clutch line 122 is
The coast clutch 42 is reached via the coast control valve 76 and the one-way orifice 77. Therefore, the third ON-OFF solenoid valve 69 is turned off.
At this time, that is, the third clutch of the D range, the second and third speeds of the S range, and the first and second speeds of the L range, the coast clutch 42 is engaged.

Further, a line 123 is branched from the forward line 111, and this line 123 is also led to the second shift valve 64. This line 123
Is the second ON-OFF solenoid valve 68 is ON,
When the spool of the second shift valve 64 is located on the left side, it communicates with the line 124 leading to the first shift valve 63. On the other hand, the first shift valve 63 has a first ON-OF
When the F solenoid valve 67 is OFF and the spool of the valve 63 is located on the right side, a line 125 communicating with the line 124 is connected, and the line 125 is connected via a low reducing valve 78, a ball valve 79 and a line 126. Are led to the third shift valve 65.

Then, the line 126 is the third ON-
When the OFF solenoid valve 69 is OFF and the spool of the third shift valve 65 is located on the left side, it communicates with the low reverse brake line 127 that communicates with the low reverse brake 46. Therefore, the first, second and third ON
-OFF solenoid valves 67 to 69 are OF
When F, ON, or OFF, that is, at the first speed in the L range, the low reverse brake 46 is engaged.

Here, the operation of the coast control valve 76 will be described. When the second ON-OFF solenoid valve 68 is ON and the spool of the second shift valve 64 is located on the left side, the line 123 is passed to the forward line 111. A line 128 is branched from the line 124 that communicates with the pressure control port 76a of the coast control valve 76, and the main line 11 is connected to the back pressure port 76b at one end of the valve 76.
Line pressure is always supplied from 0.

Therefore, when the second ON-OFF solenoid valve 68 is ON among the 3rd speed in the D range, the 2nd and 3rd speeds in the S range, and the 1st and 2nd speeds in the L range, in which the coast clutch 42 is engaged, that is, in the S range. At the second speed range and the first and second speed ranges of the L range, the coast control valve 76 has a main line 110 of the back pressure port 76b.
In addition to the line pressure from the forward line 111, the line pressure from the forward line 111 is supplied to the pressure reduction limiting port 76a, and the pressure reduction of the coast clutch pressure is suppressed accordingly, and the torque capacity of the coast clutch 42 is reduced. Will be increased.

Then, the third speed and the S in the other D range
In the third speed range, the above coast control valve 7
Since the line pressure is not supplied to the depressurization limiting port 76a of No. 6, the depressurization limiting state of the coast control valve 76 is alleviated, the coast clutch pressure is reduced, and the torque capacity of the coast clutch 42 is reduced.

On the other hand, a line 129 is branched from the retreat line 112 communicating with the main line 110 in the R range, and is led to the ball valve 79 through the one-way orifice 80. And this line 129
When the third ON-OFF solenoid valve 69 is OFF and the spool of the third shift valve 65 is located on the left side, the third shift valve 65 is connected to the low reverse brake line 127 via the line 126.

The reverse line 112 serves as a reverse clutch line 130 and reaches the reverse clutch 44 via the check valve 81. Therefore, in the R range, the low reverse brake 46 is engaged while the third ON-OFF solenoid valve 69 is OFF, while the reverse clutch 44 is always engaged. An NR accumulator 82 is connected to the line 131 branched from the line 129 between the one-way orifice 80 and the ball valve 79.

Further, the hydraulic control circuit 60 has a configuration shown in FIG.
The lockup shift valve 83 for controlling the lockup clutch 26 in the torque converter 20 shown in FIG.
And a lock-up control valve 84.

A converter line 132 led from the regulator valve 61 is branched and connected to the lockup shift valve 83 and the lockup control valve 84, and a control port 83a at one end of the lockup shift valve 83 is connected. On the main line 1
The control source pressure line 133 branched from 10 is connected,
Further, a fourth ON-OFF solenoid valve 85 for lockup control is provided.

When the fourth ON-OFF solenoid valve 85 is OFF, the spool of the lockup shift valve 83 is located on the left side, so that the converter line 132 communicates with the lockup release chamber 26a in the torque converter 20. It communicates with the release line 134, which releases the lockup clutch 26. Here, the converter line 132 has a line 1
A converter relief valve 86 is connected via 35.

Further, the fourth ON-OFF solenoid valve 85 is turned on, and the lockup shift valve 8
When the spool No. 3 moves to the right, the converter line 132 communicates with the engagement line 136 that communicates with the lockup engagement chamber 26b in the torque converter 20, thereby engaging the lockup clutch 26. And
At this time, the release line 134 communicates with the lockup control valve 84 through the intermediate line 137,
The operating pressure adjusted by the control valve 84 is supplied to the lockup release chamber 26a as lockup release pressure.

That is, the control source pressure line 138 led from the reducing valve 66 is connected to the control port 84a at one end of the lockup control valve 84.
Is connected to the pressure regulation prevention port 84b at the other end.
A pressure regulation blocking line 139 branched from the forward line 111 is connected to the valve via a bypass valve 87.

A first duty solenoid valve 89 for lockup control is installed downstream of the orifice 88 provided in the control source pressure line 138.
This first duty solenoid valve 89 controls the control port 84 of the lockup control valve 84.
When the line pressure is not supplied from the pressure regulating line 139 to the pressure regulating port 84b at the other end by adjusting the control pressure supplied to a, the intermediate line 137, the lockup shift valve 83, and the release. The release pressure supplied to the lockup release chamber 26a via the line 134 is adjusted, and the lockup clutch 26 is controlled to a predetermined slip state.

The lock-up control valve 8
4 to the pressure regulating prevention port 84b.
When the line pressure is supplied via the, the spool of the control valve 84 is fixed in a state of being positioned on the left side. Therefore, the lock-up release chamber 26a
The operating pressure is discharged from the lockup control valve 84 via the release line 134, the lockup shift valve 83 and the intermediate line 137, and the lockup clutch 26 is completely engaged.

Further, the hydraulic pressure control circuit 60 includes a throttle modulator valve 90 and a second duty solenoid valve 91 for operating the valve for controlling the line pressure adjusted by the regulator valve 61.
Is provided.

A control source pressure reduced to a predetermined pressure by the reducing valve 66 is introduced to the throttle modulator valve 90 through a line 140, and
The duty control pressure adjusted by the second duty solenoid valve 91 is introduced into the control port 90a at one end. Then, by adjusting the control source pressure derived from the line 140 according to the control pressure, a throttle modulator pressure according to, for example, the throttle opening of the engine is generated, and this is generated via the line 141 by the regulator. By being introduced into the first pressure increasing port 61a of the valve 61, the line pressure adjusted by the valve 61 is increased in accordance with an increase in the throttle opening.

The line 142 branched from the retreat line 112 is connected to the second pressure increasing port 61b of the regulator valve 61, so that the line pressure is further increased in the R range.

The duty control pressure generated by the first duty solenoid valve 89 for controlling the lockup clutch 26 is also supplied to the control port 92a of the accumulation control valve 92. The accumulation control valve 92 adjusts the line pressure supplied from the main line 110 through the line 143 according to the duty control pressure generated by the first duty solenoid valve 89, and the line 144
The pressure is supplied to the back pressure chamber 82a of the N-R accumulator 82 via.

A line 145 branched from the line 144 is a line 3 on the 3-4 clutch line 119.
-4 is connected to the control port 75a of the control valve 75. Therefore, the first duty solenoid valve 89 controls the operating pressure (3-4 clutch pressure) adjusted by the 3-4 control valve 75.

Also, this 3-4 control valve 75
Is provided with a pressure regulation blocking port 75b for blocking a pressure regulation (pressure reduction) operation at one end thereof, and is guided to the pressure regulation blocking port 75b from the main line 110 via a line 146 and a lock valve 93. Pressure regulation prevention line 1
47 is connected. Then, the lock valve 93
When the line 146 and the pressure regulation prevention line 147 communicate with each other, the line pressure from the main line 110 becomes 3-
4 is supplied to the pressure regulation blocking port 75b of the control valve 75 to block the pressure regulation operation of the control valve 75.

The lock valve 93 has a control port 93a at one end and an orifice 88 in the control source pressure line 138 and a first duty solenoid valve 89.
A line 148 branched from between and is connected,
A line 14 branched from the control source pressure line 138 upstream of the orifice 88 to the balance port 93b at the other end.
9 is connected. When the duty control pressure generated by the first duty solenoid valve 89 is equal to or higher than a predetermined value, the spool is located on the left side of the drawing so that the pressure regulation blocking line 147 communicates with the line 146 or the main line 110. It has become.

Further, the lock valve 93 is connected to a line 150 which communicates with the pressure regulation blocking line 147 when the spool is located on the right side. The line 150 is guided to the lock-up shift valve 83, and communicates with the line 151 branched from the main line 110 when the spool of the shift valve 83 is located on the right side. That is, the fourth ON-OFF solenoid valve 85 is ON, and the lockup shift valve 8
When the engagement force of the lockup clutch 26 is controllable because the spool of No. 3 is located on the right side in the drawing, the line pressure from the main line 110 causes the line 151, the lockup shift valve 83, and the line 15 to be controlled.
It is guided to the pressure regulation blocking line 147 via 0, and the pressure regulation operation of the 3-4 clutch pressure by the 3-4 control valve 75 is blocked.

Further, the lock valve 93 has a first
The drain line 15 communicating with the servo apply line 117 with the spool of the shift valve 63 positioned on the right side.
2 is connected. By the movement of the spool of the lock valve 93, the drain line 152 is selectively communicated with two drain ports having different throttle amounts, whereby the discharge speed of the servo apply pressure is changed to the first duty solenoid valve 89. It will be switched by the control of.

On the other hand, a line 153 is branched from the pressure regulation prevention line 147 and guided to the first shift valve 63, and the first ON-OFF solenoid valve 67 is ON,
When the spool of the first shift valve 63 is located on the left side, the first shift valve 63 communicates with the line 154, and the 1-2 accumulator 7
4 to the first back pressure chamber 74a. In addition, the line pressure is constantly introduced from the main line 110 into the second back pressure chamber 74b of the accumulator 74, and therefore, when the line pressure is supplied to the pressure regulation blocking line 147, the first ON-OFF solenoid valve. When 67 is ON,
The line pressure is introduced into both the first and second back pressure chambers 74a and 74b of the 1-2 accumulator 74, and the back pressure of the accumulator 74 increases.

The accumulator valve 73 branched from the servo apply line 117 and installed on the line 118 leading to the 1-2 accumulator 74 has a first control port 73a at one end thereof and a 3-4 control valve. 3-4 clutch line 11 downstream of 75
The line 155 branched from 9 is connected to the second control port 73b provided in the intermediate portion, and the low reducing valve 78, the ball valve 79, and the line 126 are connected to the second control port 73b.
A line 156 branched from the line 125 leading to the low reverse brake line 127 is connected via the third shift valve 65. Further, a pressure regulation blocking line 139 for regulating pressure regulation of the lock-up control valve 84 includes a line 157, a ball valve 94, and a line 158 at the accumulation cut prevention port 73c provided at the other end of the accumulation cut valve 73. Connected through.

When the operating pressure is introduced into the above-mentioned accumulation cut-off port 73c, the spool of the accumulation cut valve 73 is located on the right side, so that the line between the servo apply line 117 and the 1-2 accumulator 74 is moved. Although 118 is communicated, when the operating pressure is not introduced into the accumulation cut prevention port 73c, the first control port 73a or the second control port 73
When the operating pressure (3-4 clutch pressure or low reverse brake pressure) is introduced to b, the spool is located on the left side so that the accumulator 74 side of the line 118 communicates with the drain port. .

A line 159 led from the lock valve 93 is connected to the accumulation cut prevention port 73c of the accumulation cut valve 73 through the ball valve 94 and the line 158.

On the other hand, the above-described bypass valve 87 bypasses the orifice 72 on the servo apply line 117 and the second bypass line 160 bypasses the check valve 81 on the reverse clutch line 130.
The bypass line 161 and the pressure regulation blocking line 139 guided to the lockup control valve 84 are installed so as to straddle the control port 87a at one end.
Control source pressure line 16 branched from the main line 110
2 is connected, and a fifth ON-OFF solenoid valve 95 is provided, and the ON / OFF control of the solenoid valve 95 switches the spool position of the bypass valve 87, so that the first and second bypass lines are connected. The pressure control lines 160 and 161 and the pressure regulation prevention line 139 are connected or disconnected.

That is, when the fifth ON-OFF solenoid valve 95 is OFF and the spool of the bypass valve 87 is located on the right side of the drawing, the first bypass line 160 and the pressure regulation blocking line 139 are connected to each other. The second bypass line 161 is cut off. Conversely, the fifth ON-OFF solenoid valve 95 turns O
When the spool of the bypass valve 87 moves to the left at N, the first bypass line 160 and the pressure regulation blocking line 13
9 is cut off, and the second bypass line 161 is connected.

Further, as shown in FIG. 3, the automatic transmission 10 includes first to third ON-OFF solenoid valves 67 to 69 for gear shift control and a fourth O for lockup control.
A controller 200 for controlling the operation of the N-OFF solenoid valve 85, the first duty solenoid valve 89, the fifth ON-OFF solenoid valve 95 for controlling the bypass valve 87, and the second duty solenoid valve 91 for adjusting the line pressure is provided. ing.

The controller 200 outputs a signal from a vehicle speed sensor 201 for detecting the vehicle speed of the vehicle, and a throttle opening sensor 202 for detecting the opening of a throttle valve of an engine which is interlocked with an accelerator pedal operated by a driver. A signal, a signal from a shift position sensor 203 for detecting the position (range) of a shift lever included in the automatic transmission 10 and the like are input, and the above-mentioned signals are output in accordance with the driving state indicated by these signals and the driver's request. Controls the operation of each solenoid valve.

Although the automatic transmission 10 according to the present embodiment has the above-described structure, the shift control during the 4-3 shift is
When the accelerator pedal is suddenly depressed and when the accelerator pedal is gently depressed, it is properly performed as follows.

Next, the shift operation at the time of the 4-3 shift will be described with reference to the flowcharts of FIGS. 4 and 5 showing the operation of the controller 200.

First, in the fourth speed state, the controller 20
0 is 0 for the first to third ON-OFF solenoid valves 67 to 69 in step S1 of the flowchart of FIG.
The control signal is output so that the solenoid pattern for the third speed of N, OFF, and ON is obtained. Note that the fifth ON-OFF solenoid valve 95 is normally OFF, and is turned ON if necessary.

At this time, in the hydraulic control circuit 60,
As shown in FIG. 6, the spool of the first shift valve 63 is located on the left side of the drawing, and communicates the advance line 111 with the servo apply line 117. Therefore, the servo apply pressure is applied to the apply port 45b of the servo piston 45a. Is being supplied. In addition, the second shift valve 64
Is located on the right side and connects the forward line 111 to the 3-4 clutch line 119, and therefore the 3-4 clutch 43 is connected to the 3-4 clutch 43 via the 3-4 control valve (see FIG. 2) 75. Clutch pressure is being supplied. Furthermore, since the spool of the third shift valve 65 is located on the right side and the servo release line 121 is communicated with the drain port 65b, the servo piston 4
The servo release pressure is discharged from the release port 45c of 5a. Therefore, 2-4 brakes 45 and 3
Both of the -4 clutches 43 are engaged.

In this case, since the fifth ON-OFF solenoid valve 95 is OFF and the spool of the bypass valve 87 is located on the right side, on the lock-up control pressure regulation blocking line 139 branched from the forward line 111, The downstream sides 139a and 139b are communicated with each other, and the line pressure is introduced into the accumulation cut prevention port 73c on the left side of the accumulation cut valve 73 through the line 139, the line 157, the ball valve 94 and the line 158. The 3-4 clutch pressure is introduced into the first control port 73a on the right side of the accumulation cut valve 73 by the line 155 branched from the 3-4 clutch line 119, but as described above, the accumulation cut prevention port 73c.
The line pressure is introduced into the spool, so that the spool of the accumulation cut valve 73 is located on the right side, so that the servo apply line 117 is connected to the line 118 via the line 118.
The -2 accumulator 74 is in a connected state.

This is mainly due to 2 at the time of 1-2 shift.
The engagement shock of the -4 brake 45 is mitigated by introducing the servo apply pressure to the 1-2 accumulator 74, and the servo apply pressure is introduced to the accumulator 74 even in the fourth speed.

When a 4-3 shift command is input in step S2 of the flow chart of FIG. 4, the controller 20
0 indicates that the change amount (hereinafter referred to as throttle change amount) Δθ of the throttle opening θ indicated by the signal from the throttle opening sensor 202 per unit time is smaller than the predetermined value α by executing step S3 next. Or not. That is, it is determined whether or not the depressing speed of the accelerator pedal interlocking with the throttle valve indicates a slow acceleration state.

The controller 200 executes the above step S3.
When it is determined that the throttle change amount Δθ is smaller than a predetermined value, that is, when it is determined that the accelerator pedal is in the gentle depression state, the first timer is set to the predetermined time T1 in step S4, and then in step S5, A control signal is output so that the solenoid patterns of the first to third ON-OFF solenoid valves 67 to 69 become a first intermediate pattern of OFF, OFF, and ON, and the control is performed by the first timer in step S6. Continue until it is determined that it is up. Here, the predetermined time T1 set in the first timer is previously determined by an experiment or the like so that the shift operation is surely completed.

Therefore, the first ON-OFF solenoid valve 67 is switched from ON to OFF, and the spool of the first shift valve 63 moves to the right as shown in FIG. As a result, the servo apply line 117 communicates with the drain line 152 via the first shift valve 63, and this line 152 leads to the drain port of the lock valve 93 shown in FIG. 2, and therefore, in the servo piston 45a. The servo apply pressure is discharged from the apply port 45b.

In this case, since the spool of the bypass valve 87 is held in the right position, the spool of the accumulation cut valve 73 is connected to the line 118 connecting the servo apply line 117 and the 1-2 accumulator 74. As a result, the servo apply pressure discharged from the apply port 45b of the servo piston 45a is moderated by the action of the 1-2 accumulator 74. Will be exhausted (see the symbol a in FIG. 8).
reference).

Therefore, the 2-4 brake 45 is released gently, the shock at the time of release is reduced, and the decrease in acceleration during the shift operation is reduced (see reference numeral b in FIG. 8). It is also possible to prevent the driver from feeling a drag. Moreover, since the release operation of the 2-4 brake 45 progresses gently, the first one-way clutch 51 in the idling state is engaged immediately after or at the end of the release operation period of the brake 45. Will also be reduced.

When the controller 200 determines in step S6 of the flowchart that the first timer has timed out, the controller 200 proceeds to step S7 and sets a predetermined time T2 in the second timer, and then executes step S8 to execute the first to first steps. 3O
A control signal is output so that the solenoid pattern of the N-OFF solenoid valves 67 to 69 becomes a second intermediate pattern of OFF, OFF, and OFF, and this control is executed until the time-out of the second timer is determined in step S9. To do.

Therefore, the spool of the third shift valve 65 moves from the right side position shown in FIG. 7 to the left side, and the servo release line 121 communicates with the line 120 branched from the 3-4 clutch line 119. Therefore, the servo release pressure is supplied to the release port 45c of the servo piston 45a (see reference numeral c in FIG. 8).

When the controller 200 determines in step S9 of the flowchart that the second timer has timed out, it executes step S10 to execute the first
~ Control signals are output so that the solenoid patterns of the third ON-OFF solenoid valves 67 to 69 are ON, OFF, and OFF third speed patterns.

In the third speed pattern, the first ON-OFF solenoid valve 67 is OF in comparison with the second intermediate pattern.
Therefore, the spool of the first shift valve 63 is moved from the position on the right side shown in FIG. 7 to the left side to supply the servo apply pressure.

As a result, the servo apply pressure is supplied again from the forward line 111 to the apply port 45b of the servo piston 45a via the first shift valve 63 and the servo ply line 117. Then, at this time, the spool of the bypass valve 87 is located on the right side, and from the forward line 111 to the accumulation cut prevention port 73c of the accumulation cut valve 73 via the pressure regulation prevention line 139, the line 157, the ball valve 94 and the line 158. Since the line pressure is supplied, the spool of the accumulation cut valve 73 is located on the right side. Therefore, the servo apply pressure is also introduced into the 1-2 accumulator 74 via the line 118 branched from the servo apply line 117.

In this case, in the 1-2 accumulator 74, the hydraulic oil is discharged and the piston is returned to the initial position when the solenoid pattern shown in FIG. 7 is the first intermediate pattern. A pressure accumulating operation is performed when the servo apply pressure is re-supplied in accordance with the switching operation to the third speed pattern, and the servo apply pressure is gently supplied (see reference numeral d in FIG. 8).

On the other hand, the controller 200 determines the throttle change amount Δ in step S3 of the flowchart of FIG.
When θ is not smaller than the predetermined value, that is, when it is determined that the vehicle is in the sudden depression state, the process proceeds to step S11 in the flowchart of FIG.
After setting 1), in steps S12,
A control signal is output so that the solenoid pattern of the third ON-OFF solenoid valves 67 to 69 becomes the first intermediate pattern of OFF, OFF, ON, and step S13.
Then, an ON signal is output to the fifth ON-OFF solenoid valve 95, and these controls are continued until it is determined in step S14 that the first timer has timed out.

That is, as shown in FIG. 9, first the first ON
By switching the -OFF solenoid valve 67 from ON to OFF, the spool of the first shift valve 63 is moved to the right side, and at the same time, by switching the fifth ON-OFF solenoid valve 95 from OFF to ON, the spool of the bypass valve 87 is moved to the left side. Move to.

As a result, the servo apply line 117
Communicates with the drain line 152 via the first shift valve 63, and the servo apply pressure is discharged from the apply port 45b of the servo piston 45a.

At this time, the spool of the bypass valve 87 moves to the left side as described above, so that the downstream side 139b of the pressure regulation blocking line 139 communicates with the drain port 87b of the bypass valve 87, so that the accumulation cut is performed. Accumulation cut prevention port 7 of valve 73
The control pressure in 3c is discharged from the drain port 87b of the bypass valve 87 via the line 158, the ball valve 94, the line 157 and the downstream side 139b of the line 139.

In this case, the accumulation cut valve 7
3 to the first control port 73a, as described above, the line 1
Since the 3-4 clutch pressure is supplied from 55 as the control pressure, the spool of the valve 73 moves to the left side, above the line 118 branched from the servo apply line 117 to the 1-2 accumulator 74, and on the downstream side. 118
The a and 118b are shut off, and the downstream side 118b communicates with the drain port 73d of the accumulation cut valve 73.

As a result, when the servo apply pressure is discharged from the apply port 45b of the servo piston 45a, the 1-2 accumulator 74 disconnects the servo apply line 117, resulting in the apply of the servo piston 45a. The servo apply pressure discharged from the port 45b is quickly discharged (see reference numeral e in FIG. 10).

Therefore, in this case, the 2-4 brake 45 is quickly released, and a good gear shift response is obtained.

When it is determined in step S14 of the flowchart of FIG. 5 that the first timer has timed out, the controller 200 proceeds to step S15 to output an OFF signal to the fifth ON-OFF solenoid valve 95, and then to the second step in step S16. After setting a predetermined time T2 in the timer, step S17 is executed, and the first to third ON-OFF
The solenoid pattern of the solenoid valves 67-69 is O
A control signal is output so as to form a second intermediate pattern of FF, OFF, and OFF, and this control is performed in step S18.
Then, it is executed until it is determined that the second timer is up.

Therefore, the spool of the bypass valve 87 moves from the left side position to the right side shown in FIG. 9, the spool of the third shift valve 65 moves from the right side position to the left side, and the servo release line 121 becomes 3-positioned. It communicates with the line 120 branched from the 4-clutch line 119.
Therefore, the release port 45 of the servo piston 45a
Servo release pressure is supplied to c (Fig. 10).
(See symbol f).

When the controller 200 determines in step S18 of the flowchart that the second timer has timed out, it executes step S19, and the solenoid patterns of the first to third ON-OFF solenoid valves 67 to 69 are turned on and off. , A control signal is output so as to form a 3-speed pattern of OFF.

As described above, at the time of the 4-3 shift in the sudden depression of the accelerator pedal, the accumulation cut valve 73 is operated to disconnect the 1-2 accumulator 74 from the servo apply line 117. The 2-4 brake 45 is released promptly, and good gear shift responsiveness is obtained.

On the other hand, during the 4-3 gear shift with the accelerator pedal gently depressed, the accumulation cut valve 7
Since 3 is in an inoperative state and the 1-2 accumulator 74 is always connected to the servo apply line 117, the 2-4 brake 45 is released gently, and a smooth shift operation with less shock is performed. Will be done.

These controls are performed, for example, by electrically controlling the bypass valve 87 provided by bypassing the orifice 72 on the servo apply line 117 by turning on and off the fifth ON-OFF solenoid valve 95. Since it is performed, both the reduction of the shift shock at the time of gentle depression and the shift response at the time of sudden depression are achieved at a high level, and the hydraulic control circuit 60 is provided.
The configuration will be simplified.

Next, another embodiment of the 4-3 shift control will be described.

In this embodiment, the release port 45 of the servo piston 45a is used when the accelerator pedal is suddenly depressed.
It is configured to release the 2-4 brake 45 by supplying the servo release pressure to c. The 4-3 shift control in this case is specifically performed as follows according to the flowchart of FIG. .

That is, when the controller 200 inputs the 4-3 shift command in step T1 of the flowchart, it executes step T2 so that the throttle change amount Δθ is smaller than the predetermined value α based on the throttle opening θ. Determine whether or not.

The controller 200 executes the above step T2.
When it is determined that the throttle change amount Δθ is smaller than the predetermined value, that is, when the accelerator pedal is slowly depressed, the first timer is set to the predetermined time T1 in step T3, and then in step T4, The control signal is output so that the solenoid patterns of the first to third ON-OFF solenoid valves 67 to 69 become the first intermediate pattern of OFF, OFF, and ON, and at the time of this control, the first timer is timed out. Continue until it is determined.

When the controller 200 determines that the time of the first timer has expired, the controller 200 proceeds to step T6 to set the predetermined time T2 in the second timer and then executes step T7 to execute the first to third ON-OFF solenoid valves. 67-
A control signal is output so that the solenoid pattern of 69 becomes a second intermediate pattern of OFF, OFF, and OFF, and this control is executed until it is determined at step T8 that the time of the second timer is up.

When the controller 200 determines that the time of the second timer has expired, the controller 200 executes step T9, and the first to third ON-OFF solenoid valves 67 are executed.
The control signal is output so that the solenoid patterns of ~ 69 are ON, OFF, and OFF third speed patterns.

On the other hand, when the controller 200 determines in step T4 that the throttle change amount Δθ is not smaller than the predetermined value, that is, it is in the rapid depression state, it skips steps T3 to T8 and immediately executes step T9. , The solenoid patterns of the first to third ON-OFF solenoid valves 67 to 69 are ON, OFF, and O.
The control signal is output so as to form the 3-speed pattern of the FF.

Next, the operation of this embodiment will be described.

That is, when the accelerator pedal is suddenly depressed, the solenoid pattern is immediately switched from the fourth speed pattern to the third speed pattern. Therefore, as shown in FIG. 12, the spools of the first to third shift valves 63 to 65 are arranged. Are located on the left side, the right side, and the left side, respectively.
That is, the spool of the third shift valve 65 moves from the right side to the left side as compared with the state of the fourth speed, and the servo release line 121 communicates with the line 120 branched from the 3-4 clutch line 119. Therefore, the servo release pressure is supplied to the release port 45c of the servo piston 45a (see reference numeral g in FIG. 10). As a result, the 2-4 brake 45 is immediately released, and the shift speed is rapidly shifted to the 3rd speed.

The control operation in the state where the accelerator pedal is gently stepped on is the same as that of the above-mentioned embodiment, and therefore its explanation is omitted.

As described above, in this embodiment, during the 4-3 shift when the accelerator pedal is suddenly depressed,
By switching the solenoid pattern from the fourth speed pattern to the third speed pattern when the 4-3 shift command is generated,
Since the servo release pressure is supplied to the release port 45c of the servo piston 45a, the 2-4 brake 45 is released promptly, and good gear shift responsiveness is obtained.

On the other hand, at the time of the 4-3 gear shift in the state where the accelerator pedal is gently stepped on, when the accumulation cut valve 73 is in the non-actuated state as in the above embodiment,
-2 Accumulator 74 to servo apply line 117
Since it is always connected to 2-4 brake 4
Since 5 is released gently, smooth shift operation with less shock is performed.

[0119]

As described above, according to the present invention, the fastening hydraulic pressure supply / discharge means for supplying / discharging the fastening hydraulic pressure to / from the predetermined friction element and the fastening for adjusting the supply / discharge timing of the fastening hydraulic pressure by the supply / discharge means. And a hydraulic pressure supply / discharge adjusting means for use, in which the fastening hydraulic pressure supply / discharge adjusting means is switched between a state in which the timing for supplying and discharging the fastening hydraulic pressure can be adjusted and a state in which the timing adjusting operation is suppressed. Means is provided to set the switching means in a state in which the timing for supplying / discharging the engaging hydraulic pressure can be adjusted by the engaging hydraulic pressure supply / discharge adjusting means when the accelerator pedal depression speed is low. When the gear is downshifted to the predetermined gear position where the elements are released, the engagement hydraulic pressure is gently exhausted, and a smooth gearshift operation with less shock is performed when the pedal is gently depressed. That.

On the other hand, when the accelerator pedal is depressed at a high speed, the switching means is switched to a state in which the operation for adjusting the supply / discharge timing of the engaging hydraulic pressure by the engaging hydraulic pressure supply / discharge adjusting means is suppressed. The engaging hydraulic pressure for is rapidly exhausted, and the responsiveness of the shift at the time of sudden depression is also secured.

Further, according to the third aspect of the invention, the shift shock at the time of downshifting to the shift stage, which is achieved by engaging the one-way clutch at the time of releasing the predetermined friction element, effectively suppresses the shift shock particularly at the time of gentle depression. Will be done.

Further, according to the fourth aspect of the invention, since the switching valve which constitutes the switching means of the second aspect of the invention is configured to operate by the operation of the solenoid valve, the discharge pressure of the engaging hydraulic pressure to the friction element is discharged. Since it can be performed at an optimum timing by electrical control, and particularly according to the fifth aspect of the invention, a solenoid valve for a bypass valve is used as the solenoid valve, so that the control at the time of discharging the hydraulic pressure is performed. By effectively utilizing this solenoid valve, the above effect can be achieved while suppressing the complexity of the structure of the hydraulic control circuit.

On the other hand, according to the sixth aspect of the invention, when the predetermined friction element is a friction element which has the engagement chamber and the release chamber and is in the engagement state when the hydraulic pressure is supplied only to the engagement chamber, When the accelerator pedal depressing speed is low, the engaging hydraulic pressure supplying / discharging means performs the engaging hydraulic pressure discharging operation while the releasing hydraulic pressure supplying / discharging means stops the releasing hydraulic pressure supplying operation. When the accelerator pedal is released, the release hydraulic pressure supply / discharge means performs the release hydraulic pressure supply operation to ensure the shift responsiveness when the accelerator pedal is suddenly depressed, and the smooth shift operation with less shock when the accelerator pedal is gently depressed. Will be done.

[Brief description of drawings]

FIG. 1 is a skeleton diagram of an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a hydraulic control circuit of the automatic transmission according to the embodiment.

FIG. 3 is a control system diagram for each solenoid valve in the hydraulic control circuit of FIG.

FIG. 4 is a flowchart showing a part of shift control at the time of 4-3 shift in the embodiment.

FIG. 5 is a flowchart showing a part of shift control at the time of 4-3 shift in the embodiment.

FIG. 6 is an enlarged view of a main part of a hydraulic control circuit showing a state before a gear shift in the 4-3 gear shift.

FIG. 7: 4-3 in a state where the accelerator pedal is gently depressed
FIG. 3 is an enlarged view of a main part of a hydraulic control circuit showing a state during shifting during shifting.

FIG. 8 is a time chart showing a change in hydraulic pressure when the accelerator pedal is gently depressed.

FIG. 9 is a state in which the accelerator pedal is suddenly depressed 4-3.
FIG. 3 is an enlarged view of a main part of a hydraulic control circuit showing a state during shifting during shifting.

FIG. 10 is a time chart diagram similarly showing a change in hydraulic pressure when the accelerator pedal is suddenly depressed.

FIG. 11 is a flowchart showing another embodiment of 4-3 shift control.

FIG. 12 is an enlarged view of an essential part of the hydraulic control circuit, similarly showing a state during shifting during the 4-3 shift when the accelerator pedal is suddenly depressed.

FIG. 13 is a time chart showing a change in hydraulic pressure when the accelerator pedal is suddenly depressed.

[Explanation of symbols]

 10 Automatic Transmission 45 2-4 Brake 45b Fastening Chamber 45c Release Chamber 72 Orifice 73 Accumulation Cut Valve 74 Accumulator 87 Bypass Valve 95 Solenoid Valve 200 Controller 202 Throttle Opening Sensor

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yuji Nakahara No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Inventor Gen. Nakano No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Corporation (72) Inventor Toshihisa Maruesue 3-1, Fuchu-cho Shinchi, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Hiroyuki Matsumoto 3-1-1 Shinchu, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd.

Claims (6)

[Claims] 1. A fastening hydraulic pressure supply / discharge means for supplying / discharging a fastening hydraulic pressure to / from a predetermined friction element, and a fastening hydraulic pressure supply / discharge adjusting means for adjusting a timing of supplying / discharging the fastening hydraulic pressure by the supply / discharge means. In addition, there is provided a shift control device for an automatic transmission configured to release the predetermined friction element at the time of downshifting to a predetermined shift speed, wherein the fastening hydraulic pressure supply / discharge adjusting means is used to control the fastening hydraulic pressure. Switching means for switching between a state in which the supply / discharge timing can be adjusted and a state in which the timing adjustment operation is suppressed, a stepping speed detecting means for detecting the stepping speed of the accelerator pedal, and a shift down shift to the predetermined shift stage. At the time, when the stepping speed of the accelerator pedal detected by the stepping speed detecting means is small,
The switching means is set to a state in which the timing for supplying / discharging the fastening hydraulic pressure by the hydraulic pressure supply / discharge adjusting means for fastening can be adjusted, and when the stepping speed is high, the switching means is used for fastening the hydraulic pressure supply / discharge adjusting means for fastening. A shift control device for an automatic transmission, comprising: a control unit that switches to a state in which an adjustment operation of a hydraulic pressure supply / discharge timing is suppressed. 2. The fastening hydraulic pressure supply / discharge adjusting means is an accumulator connected to a fastening oil passage communicating with a predetermined friction element, and the switching means is a position connecting the accumulator and the fastening oil passage, The control means is composed of a switching valve for switching the connection state of the both to a position in which the connection state is cut off, and the control means controls the pedaling speed of the accelerator pedal detected by the pedaling speed detecting means during downshifting to the predetermined speed. When is small, the switching valve is set to a position where the accumulator and the connecting oil passage are connected, and when the stepping speed is high, the switching valve is switched to a position where the accumulator and the connecting oil passage are cut off. The shift control device for an automatic transmission according to claim 1, wherein the shift control device is configured. 3. The automatic transmission according to claim 1, wherein the predetermined shift speed is a shift speed achieved by engaging a one-way clutch when the predetermined friction element is released. Shift control device. 4. The shift control device for an automatic transmission according to claim 2, wherein the switching valve is configured to operate by actuation of a solenoid valve. 5. A solenoid valve is for controlling this bypass valve in a configuration in which an orifice is provided in a fastening oil passage of a predetermined friction element and a bypass valve which bypasses this orifice is provided. The shift control device for an automatic transmission according to claim 4, wherein: 6. A predetermined friction element, which has a fastening chamber and a release chamber, is brought into a fastening state when hydraulic pressure is supplied only to the fastening chamber, and a releasing hydraulic pressure of the friction element with respect to the release chamber is provided. Release hydraulic pressure supply / discharge means for supplying / discharging, fastening hydraulic pressure supplying / discharging means for supplying / discharging fastening hydraulic pressure to / from the fastening chamber, and fastening hydraulic pressure supplying / discharging timing for adjusting fastening hydraulic pressure by the supply / discharge means. A shift control device for an automatic transmission, which is provided with a discharge adjusting means and is configured to release the friction element at the time of downshifting to a predetermined shift stage, and detects a stepping speed of an accelerator pedal. When the depression speed of the accelerator pedal detected by the depression speed detecting means is low at the time of downshifting to the predetermined shift speed, the release hydraulic pressure supply / discharge means releases the pedal. With the hydraulic pressure supply / discharging means for fastening, the hydraulic pressure supply / discharging means for fastening is discharged, and when the stepping speed is high, the hydraulic pressure supply / discharging means for release is supplied with hydraulic fluid for release. A shift control device for an automatic transmission, comprising: