JP2000179663A - Control device for automatic transmission - Google Patents

Abstract

(57) Abstract: a plurality of gear stages (third speed, fifth speed, reverse gear) equipped with a hydraulic engaging element C3 that is shared, electromagnetic the regulating valve 6 ₃ the hydraulic pressure supplied to said element C3 in those pressure regulating according to a signal pressure from the valve 7 _3, reducing the charge at big shift torque ( "N" → "R" gear state which is depressing immediate accelerator during) the shift shock. A connecting accumulator 19 to the oil passage L6 between the hydraulic engaging elements C3 Doo regulating valve 6 _3. "D"
The oil passage L2 connected to the hydraulic pressure source 4 in the “M” range and opened to the atmosphere in the “R” range is connected to the back pressure chamber 1 of the accumulator 19.
9a to prevent the accumulator 19 from accumulating pressure in the "D" and "M" ranges. When stepping immediate accelerator when "R" in-gear, switched to fully open pressure regulating valve 6 _3, to buffer the hydraulic pressure rise in the hydraulic engaging elements C3 in the accumulator action of the accumulator 19.

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 mounted on a vehicle.

[0002]

2. Description of the Related Art Conventionally, in a planetary gear type automatic transmission, a hydraulic coupling element shared by a plurality of gears is provided, and each gear is selected by coupling the common hydraulic coupling element with another hydraulic coupling element. It is being established. Here, the ratio of the torque shared by the shared hydraulic coupling element to the input shaft torque generally differs at each shift speed.

By the way, in order to reduce the shift shock,
It is necessary to gradually shift the hydraulic connection element from the released state to the connected state during gear shifting. Therefore, conventionally, an accumulator is connected to an oil passage connected to the hydraulic connection element to buffer a sudden rise in the hydraulic pressure of the hydraulic connection element. A direct control system in which a pressure regulating valve controlled by an electromagnetic valve such as a solenoid valve is interposed and the hydraulic pressure supplied to the hydraulic connection element is regulated by the pressure regulating valve in accordance with the signal pressure from the electromagnetic valve has become mainstream.

[0004]

By the way, the first and the second
A hydraulic coupling element shared by at least two of the gears, wherein the ratio of the torque that the hydraulic coupling element bears to the input shaft torque is set to be greater in the first gear than in the second gear. When the shift is established to establish the second gear, the hydraulic coupling element starts to be connected in a relatively low pressure range because the bearing torque is relatively small. On the other hand, when the gear is established to establish the first gear, Due to the change in input shaft torque due to the engine load, the bearing torque changes significantly.When the load is low, the hydraulic connection elements start to connect in a relatively low pressure range, but when the load is high, the hydraulic connection elements connect in a relatively high pressure range. start.

In order to reduce the shift shock by the direct control method, it is necessary to improve the pressure regulation accuracy in a coupling start region where the hydraulic coupling element starts to be coupled. The width of the hydraulic range in which pressure can be applied cannot be secured as wide as the left, and the first hydraulic pressure range during the shift to the second shift stage or in the low load state
Although the shock at the time of shifting to the first shift speed can be reduced, when shifting to the first shift speed under a high load state, the hydraulic connection element starts to be connected in a hydraulic range higher than the hydraulic range with good pressure adjustment accuracy. As a result, a shift shock occurs.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a control device capable of reducing a shift shock at any shift.

[0007]

Means for Solving the Problems In order to solve the above problems,
The present invention includes a hydraulic coupling element shared by at least two of the first and second shift speeds, wherein the ratio of the torque that the hydraulic coupling element bears to the input shaft torque is the second at the first shift speed.
A control device for an automatic transmission set to be larger than the gear stage, wherein the control device includes a pressure regulating valve that regulates a hydraulic pressure supplied to the hydraulic coupling element in accordance with a signal pressure from an electromagnetic valve. An accumulator connected to an oil passage between a hydraulic connection element and the pressure regulating valve; and a shift for preventing the accumulator from accumulating during the shift for establishing the second shift stage and establishing the first shift stage. In some cases, the apparatus includes first switching means for enabling the accumulator to accumulate pressure, and second switching means for switching the pressure regulating valve to a fully open state.

The accumulator is set so as to perform a pressure accumulating operation in a relatively high pressure range.
If the pressure regulating valve is switched to the fully open state when the gear is established and the engine load is equal to or higher than the predetermined value, the connection start area of the hydraulic connection element becomes relatively high. At the time of shifting to the first shift stage with the engine under a high load, the hydraulic pressure of the hydraulic connection element is quickly increased to the connection start area by switching the pressure regulating valve to the fully open state, and then the connection start area is accumulated by the accumulator. Thus, the increase in the hydraulic pressure at the time is buffered, so that the shift shock can be reduced without deteriorating the response of the shift.

At the time of shifting to the second shift speed, the pressure accumulating operation of the accumulator is blocked, so that the hydraulic pressure regulated by the pressure regulating valve is supplied to the hydraulic coupling element without being affected by the accumulator, and the hydraulic coupling is performed. The shift shock can be reduced by appropriately controlling the rise of the oil pressure in the connection start region of the elements by the pressure regulating valve. In addition, when shifting to the first speed, the accumulator can accumulate the pressure. However, when the engine is under a low load, the connection start area of the hydraulic connection element is lower than the accumulator start pressure. The hydraulic pressure in the range can be controlled by the pressure regulating valve without being affected by the accumulator, and the shift shock can be reduced as in the case of shifting to the second shift speed.

In the embodiment described later, the third clutch C3 shared by the third speed, the fifth speed, and the reverse speed corresponds to the hydraulic connection element, and the reverse speed corresponds to the first speed. The third gear, the third gear, and the fifth gear correspond to the second gear. Also, to correspond to the pressure regulating valve and the solenoid valve is the third shift control valve 6 ₃ and the third solenoid valve 7 _3, to correspond to the first switching means is a manual valve 5, the first What corresponds to the second switching means 6 solenoid valve 7 ₆ and the on-off valve 2
It is one.

By the way, even if a hydraulic connection element establishes only a predetermined gear position, if the connection start pressure of the hydraulic connection element greatly changes according to the engine load, the hydraulic connection element and the hydraulic connection element as described above are used. An oil path between the pressure regulating valve and an accumulator that performs a pressure accumulating operation only when the hydraulic pressure supplied to the hydraulic connection element is equal to or more than a predetermined value is connected. And, by providing a switching means for switching the pressure regulating valve to a fully open state when the engine load is equal to or more than a predetermined value, it is possible to reduce an increase in the hydraulic pressure in the connection start area of the hydraulic connection element during a gear shift under a low engine load state. Appropriate control is performed by the pressure regulating valve, and during gear shifting under a high engine load state, an increase in the hydraulic pressure in the connection start region of the hydraulic connection element can be buffered by the accumulator operation.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 1 denotes an automatic transmission for a vehicle. The transmission 1 has an input shaft 1a connected to an engine (not shown) via a fluid torque converter and a vehicle. Output shaft 1 connected to the driving wheels of the vehicle through a differential gear (not shown)
b between the first and third planetary gears 2 ₁ , 2 ₂ , 2 ₃
, And a planetary gear type transmission that performs six forward speeds and one reverse speed.

Each of the planetary gears 2 ₁ , 2 ₂ , 2 ₃ comprises a sun gear 2 a
When a ring gear 2b, both gears 2a, a pinion 2c which meshes with 2b, is constituted by a carrier 2d for supporting the pinion 2c, connecting the first planetary gear 2 ₁ sun gear 2a on the input shaft 1a together, and it connects the third planetary gear 2 ₃ carriers 2d to the output shaft 1b. Further, the first planetary gear 2 ₁ of the ring gear 2b of the transmission 1 casing 1c
And the sun gears 2a, 2a of the second and third planetary gears 2 ₂ , 2 ₃ are connected to each other.
The second planetary gear 2 ₂ carrier 2d of the third planetary gear 2 ₃ ring gear 2b connected, are connected via a one-way clutch 3 as a reaction force receiving the ring gear 2b to the casing 1c.

The transmission 1 has an input as a hydraulic connection element.
The shaft 1a is connected to the second and third planetary gears 2 _Two, 2_ThreeSun gear 2
a, 2a and the first clutch C1 connected to the input shaft 1a.
2nd planetary gear 2_TwoThe second clutch connected to the carrier 2d
C2 and the first planetary gear 2₁Carrier 2d to the second planet
Gear 2_TwoClutch C3 connected to the ring gear 2b
And the second planetary gear 2_TwoRing gear 2b to casing 1
c and the third planetary gear 2_Threeof
Second brake connecting ring gear 2b to casing 1c
Key B2.

With the above configuration, the first gear is established when the first clutch C1 and the second brake B2 are connected.
The second gear is established when the first clutch C1 and the first brake B1 are engaged, and the third gear is established when the first clutch C1 and the third clutch C3 are engaged. The fourth gear is established when the second clutch C2 is engaged, and the fifth gear is established when the second clutch C2 and the third clutch C3 are engaged, and the second clutch C2 and the first brake B1 are engaged. 6th gear is established when
The reverse gear is established when the third clutch C3 and the second brake B2 are connected.

The operation of these clutches C1, C2, C3 and brakes B1, B2 is controlled by a hydraulic circuit shown in FIG. The hydraulic circuit includes a hydraulic source 4 and a manual valve 5.
And each clutch C1, C2, C3 and each brake B1, B2
5 and five shift control valves 6 _{1 through 65} of the first through fifth individually controlling the supply and discharge oil of the first through fifth control each shift control valve 6 _{through 65} individually to number of the electromagnetic valves 7 ₁ to 7 ₅ are provided.

The manual valve 5 is interlocked with the operation of a select lever (not shown) to operate the "P" position as a parking range, the "R" position as a reverse range, and the "N" position as a neutral range (positions shown). And a "D" position, which is an automatic transmission range for forward traveling, and an "M" position, which is a manual transmission range for forward traveling, for a total of five positions. At the “D” position and the “M” position, the oil passage L1 connected to the hydraulic pressure source 4 is connected to the oil passage L2, and the pressure oil adjusted to a predetermined line pressure by the regulator 8 is supplied to the oil passage L2, with oil is supplied constantly to the second shift control valve 6 ₂ for the second clutch C2 via the oil passage L2, the oil path L connected through a fail-safe valve 9 to be described later in detail to the oil passage L2
3, a first transmission control valve 6 for the first clutch C1
_1, a first fourth shift control valve 6 ₄ for the brake B1, second
Oil is supplied to the fifth shift control valve 6 ₅ for the brake B2.
Incidentally, the third shift control valve 6 ₃ for the third clutch C3 is fueling regardless constantly the manual valve 5 via the oil passage L1.

The first to third clutches C1, C2, C
3 and the oil passages L4, L5 connected to the first brake B1, respectively.
L6 and L7 are the first to fourth speed change control valves 6 ₁ , 6 ₂ , 6 ₃ ,
6 ₄ are directly connected, but the selective oil passage L8 leading to the second brake B2 via the shuttle valve 10 to an oil passage L9 leading to the oil passage L8a and the manual valve 5 continuing to the fifth shift control valve 6 ₅ Is to be connected to. Oil passage L9 is connected to the oil passage L1 in the "R" position of the manual valve 5, and thus, in the "R" position, the second brake B2 is always connected, by refueling from the third shift control valve 6 ₃ The reverse gear is established by the connection of the third clutch C3.

[0019] Each shift control valve 6 _{through 65,} an oil chamber 6a for pressing the respective shift control valves 6 _{through 65} to the oil supply position side of the left, oil discharge position on the right side (the illustrated position) An oil chamber 6b pressed to the side;
And a spring 6c for accommodating the oil chamber 6b, respective solenoid valves 7 ₁ to the signal pressure from the solenoid valves 7 ₁ to 7 ₅ corresponding to the oil chamber 6a of the shift control valve 6 _{through 65} each oil passage L10 which is communicated with the 7 ₅
And inputs via the ～L14, the shift control valve 6 ₁
6 ₅ oil chamber 6b enter the downstream side of the oil pressure of the respective shift control valves 6 _{through 65,} the downstream side of the shift control valve 6 _{through 65} hydraulic, i.e., the hydraulic engaging element C1, C2 , C3, B1, the oil pressure of B2 is configured on the pressure regulating valve may by regulating in response to the signal pressure from the solenoid valves 7 ₁ to 7 _5.

[0020] each of the electromagnetic valve 7 _{1-7 5,} the solenoid 7a
And a linear solenoid valve that outputs a signal pressure corresponding to a current value supplied to the solenoid valves 7 _{1 to} 7 ₅ by an electronic control circuit 11 including an on-board computer.
a is controlled. Note that each the electromagnetic valves 7 ₁ to 7 ₅ are input modulator pressure from the modulator valve 12 connected to the oil passage L1 (a constant pressure lower than the line pressure), the signal pressure output in the fully open state modulator Pressure.

[0021] In the "D" position and "M" position of the manual valve 5 allows lubrication to all the shift control valve 6 _{through 65,}
Higher signal pressure from the first solenoid valves 7 ₁ 5, 7 _5, refueling the first and fifth shift control valves 6 _1, 6 ₅ first clutch C1 via the second brake B2 When the first gear is established and the signal pressure from the first and fourth solenoid valves 7 ₁ and 7 ₄ is increased, the first clutch is connected via the first and fourth shift control valves 6 ₁ and 6 _4. C1 and refueling has been second speed to the first brake B1 is established, the higher the first and third solenoid valves 7 _1, 7 ₃ signal pressure, the first and third shift control valves 6 _1, 6 ₃ are the first and third clutches C1, oil is supplied to the C3 and the third speed is established through, increasing the first and second electromagnetic valves 7 _1, 7 ₂ of the signal pressure, the first and second Via the _second shift control valve 6 ₁ , 6 ₂
When the fourth speed stage is fueling the second clutches C1, C2 are established, the higher the second and third solenoid valves 7 _2, 7 ₃ signal pressure, second and third shift control valves 6 ₂ , second and refueling has been fifth speed is established in the third clutch C2, C3 through 6 _3, the higher the second and fourth solenoid valves 7 _2, 7 ₄ signal pressure, and the second The oil is supplied to the second clutch C2 and the first brake B1 via the fourth shift control valves 6 ₂ and 6 ₄ to establish the sixth speed.

In the "D" position, the electronic control circuit 1
1 by controlling the respective solenoid valves 7 ₁ to 7 ₅ according to the running state of the vehicle, performs automatic speed changing of the first speed through the sixth speed, the "M" position, in an unshown upshift switch and downshift switch Each solenoid valve 7 _{1 is} operated by the electronic control circuit 11 via the electronic control circuit 11.
To 7 ₅ to control, performs upshift or downshift every time the up-shift switch and a downshift switch is turned on. Further, at the time of shifting, the pressure increase of the hydraulic connecting element connected at the time of shifting and the decrease of the hydraulic pressure of the hydraulic connecting element which is disconnected at the time of shifting are appropriately controlled by corresponding solenoid valves so as not to cause a shift shock. .

Here, the first, fourth and fifth solenoid valves 7 ₁ , 7
_4, 7 ₅ at establishment of each gear position of the normally closed, with the second and third solenoid valves 7 _2, 7 ₃ are configured to normally open, "D" position and "M" position solenoid valve 7 _1-7 turn-on states of the _fifth solenoid 7a and the hydraulic coupling elements C1 to C3, when showing the connection state of the B1, B2, becomes as in FIG. In the drawings, the symbol “〇” indicates that the hydraulic connection element is connected, and the symbol “x” indicates that the hydraulic connection element is released.

By the way, even when three or more hydraulic connection elements are connected at the same time, or when two hydraulic connection elements are connected at the same time, when the third clutch C3 and the first brake B1 are connected, the meshing And the transmission 1 is locked, and when the third clutch C3 and the second brake B2 are connected during forward traveling, the reverse gear is established, and the transmission 1
And the engine takes too much.

[0025] Therefore, in this embodiment, first to fifth one gear shift control valve 6 _{through 65} of a predetermined, for example, 5
A first group of second and third shift control valves 6 ₂ , 6 ₃ corresponding to the second and third clutches C 2, C 3 for establishing the speed stage, and other continuous pressure connection elements C 1, B 1, B 2 Are divided into a second group consisting of _first , _fourth , and fifth shift control valves 6 ₁ , 6 ₄ , 6 ₅ , and the second group of shift control valves 6 ₁ , 6 ₄ , 6 ₅ A continuous oil passage L3 and an oil passage L serving as a fuel supply passage
In the event of a failure in which a plurality of hydraulic connection elements that must not be connected at the same time are provided with a fail-safe valve 9 interposed between the transmission control valve 2 and the second group of shift control valves 6 ₁ ,
6 ₄ stops the oil supply to 6 _5, and to be able to prevent the above problem.

The fail-safe valve 9 includes an oil passage L2 and an oil passage L
3 can be switched between a left open position for connecting the valve 3 and a right closed position (the position shown) for disconnecting the connection, and the line pressure from the oil passage L1 is applied to the oil chamber 9a at the right end of the fail-safe valve 9. And presses the fail-safe valve 9 to the open position side. Further, the fail-safe valve 9 is provided with four oil chambers 9b, 9c, 9d, 9e for pressing the same toward the closed position.
b, the oil pressure of the third clutch C3 from the oil passage L6, the oil pressure of the first brake B1 from the oil passage L7 to the oil chamber 9c, and the oil pressure of the second brake B2 from the oil passage L8a to the oil chamber 9d. The line pressure from the oil passage L1 is input to 9e via a combined signal valve 13, which will be described in detail later, and the fail-safe valve 9 is urged toward the closed position by a spring 9f. When the oil pressure input to any two of the oil chambers 9b, 9c, 9d, and 9e becomes equal to or higher than a predetermined pressure, the resultant force of the pressing force by these oil pressures and the urging force of the spring 9f becomes oil. The failsafe valve 9 is switched to the closed position by exceeding the pressing force due to the line pressure input to the chamber 9a. The combined signal valve 13 is switchable between a right open position (position shown) for connecting the oil passage L1 to the oil chamber 9e and a left closed position for disconnecting this connection. Oil chamber 13a
The line pressure from the oil passage Ll is input to the valve to press the valve 13 toward the open position, and further, the combined signal valve 13 is provided with two oil chambers 13b and 13c that press the valve toward the closed position. Oil chamber 13
b, the oil pressure of the second clutch C2 from the oil passage L5 and the oil chamber 13c.
The hydraulic pressure of the first clutch C1 is input from the oil passage L4, and the combined signal valve 13 is urged toward the closed position by the spring 13d to connect the first and second clutches C1 and C2 together ( When the vehicle is in the fourth gear stage), the oil chambers 13b, 13
The composite signal valve 13 is switched to the open position when the combined force of the pressing force by the hydraulic pressure input to c and the urging force of the spring 13d exceeds the pressing force by the line pressure input to the oil chamber 13a.

Thus, the first and second clutches C1, C
2 are connected together, the line pressure is input to the oil chamber 9e of the fail-safe valve 9, and in this state, the other hydraulic connection elements C
When any one of 3, B1, B2 is refueled, the failsafe valve 9 is switched to the closed position, and only one of the first and second clutches C1, C2 is connected, or Even when both clutches C1 and C2 are disengaged and no line pressure is input to oil chamber 9e, if oil is supplied to two or more of the other hydraulic connection elements C3, B1, and B2,
The failsafe valve 9 switches to the closed position. When the fail-safe valve 9 is switched to the closed position, the oil passages L2 and L
3 Connection between is cut off, after all, at the time of failure oil supply to shift control valve 6 _1, 6 _4, 6 ₅ in the second group is stopped, the hydraulic coupling elements C1, B1, B2 corresponding is released.

An oil passage L15 connected to the oil passage L2 through the valve 9 at the closed position of the fail-safe valve 9 is provided, and an oil passage connected to the third clutch C3 is provided in the oil chamber 9b of the fail-safe valve 9. and L6 and the oil passage L15 together are connected via a shuttle valve 14 _1, to the oil chamber 9c of the fail-safe valve 9,
An oil passage L7 and the oil passage L15 communicating with the first brake B1 are connected through a shuttle valve 14 _2. Thus, once the fail-safe valve 9 is switched to the closed position during a failure,
The line pressure from the oil passage L2 is input to the oil chambers 9b, 9c via the oil passage L15, and the second group of shift control valves 6 ₁ , 6 ₄ ,
Hydraulic engaging elements C1 addressed in fueling stops to 6 _5, B1, B
Even if the oil pressure of 2 falls, the fail-safe valve 9 is kept in the closed position, and chattering of the fail-safe valve 9 is prevented.

Even if the fail-safe valve 9 is switched to the closed position at the time of a failure, the second transmission control valve 6 _{2 of} the first group can be used.
When the third shift control valve 6 _3, respectively, the oil supply passage serving oil passage L
2 and the oil passage L1, the second clutch C
The fifth speed can be established by connecting the second and third clutches C3. However, if not be switched to the second shift control valve 6 ₂ and the third shift control valve 6 ₃ to the oil supply position side a control failure of the second solenoid valve 7 ₂ and the third electromagnetic valve 7 _3, i.e., serving as normally open When the second, can not be output pressure signal pressure from these solenoid valves 7 _2, 7 ₃ at the third electromagnetic valve 7 _2, 7 ₃ oN failure (failure continues to be energized to the solenoid), the second and third clutches C2 ,
C3 cannot be refueled and the fifth gear cannot be established.

Therefore, in the present embodiment, the second and third shift control valves 6 ₂ and 6 ₃ are pressed toward the refueling position by the second shift control valves 6 ₂ and 6 ₃ .
And the oil passage L15 is connected to the oil chamber 6d. When the fail-safe valve 9 is in the closed position, the line pressure from the oil passage L2 as the oil supply passage is applied to the oil chamber 6d via the oil passage L15. The shift control valves 6 ₂ , 6 ₃ are forcibly switched to the refueling position and input to be input. Thus, when the fail-safe valve 9 is switched to the closed position at the time of a failure, both the second and third clutches C2 and C3 are forcibly refueled, and the fifth gear is reliably established.

Further, when energization to all of the solenoid valves 7 ₁ to 7 ₅ with system-down due to disconnection or the like is stopped, normally open serving second and third two solenoid valves 7 _2, 7 ₃ signal pressure only increases, second and third two shift control valves 6 _2, 6 ₃ and the second through the third two clutches C2, oil is supplied to the C3 and fifth speed is established. However, starting and low-speed traveling becomes difficult only with the fifth gear, so when the system is down, the fifth gear is established in the “D” position, and the gear lower than the fifth gear, for example, 3 gears in the “M” position. It is desired to establish a gear position so that the gear can be shifted to the fifth speed and the third speed by the range switching operation between "D" and "M". For this purpose, the second clutch C2 is set to the "M" position. Instead, it is necessary to connect the first clutch C1.

Therefore, in the present embodiment, the second solenoid valve 7_Two
The oil passage L11 connected to the second speed change control valve 6_TwoOil chamber 6a
First shift control valve 6₁To selectively connect to the oil chamber 6a
A replacement valve 15 is provided, and when the system is down, at the “D” position,
The oil passage L11 is connected to the second shift control valve 6 _TwoOil chamber 6a,
Second solenoid valve 7_TwoThe second shift control valve with a high signal pressure from
6 _TwoTo the refueling position to connect the second clutch C2.
In the “M” position, the oil passage L11 is connected to the first transmission control valve 6.₁
Of the first speed change control valve 6₁The refueling position
And the first clutch C1 is engaged.
You.

The switching valve 15, the oil passage L10 and the second electromagnetic valve 7 respectively and oil passage L11 which is communicated with the ₂ s first shift control valve 6 ₁ oil chamber 6a and the second shift control leading to the first solenoid valve 7 ₁ first switching position of the right to be connected to the oil chamber 6a of the valve 6 ₂ (the illustrated position)
And disconnect the oil passage L11 so that the first transmission control valve 6
_It can be switched to the left second switching position connected to the _first oil chamber 6a, and the switching valve 15 is urged toward the first switching position by a spring 15a. Further, the switching valve 15 is provided with a left-end oil chamber 15b for pressing the switching valve 15 toward the first switching position and a right-end oil chamber 15c for pressing the switching valve 15 toward the second switching position. Connected to the oil passage L1 at the “D” position,
With connecting oil passage L16 which is opened to the atmosphere in the "M" position, and inputs the signal pressure from the oil chamber second solenoid valve 7 via the oil passage L17 which is branched from the oil passage L11 to 15c _2. Thus, in the "D" position, the line pressure from the oil passage L1 to the oil chamber 15b is input, even if the signal pressure from the second solenoid valve 7 ₂ in system down becomes maximum pressure (modulator pressure), switching Although the valve 15 is held in the first switching position, the "M" position, the oil chamber 15b is opened to the atmosphere via the oil passage L16, the signal pressure from the second solenoid valve 7 ₂ in system down top becomes the high pressure, the switching valve 15 is switched to the second changeover position, the first shift control valve 6 ₁ as described above is connected first clutch C1 is switched to the oil supply position, the third speed ratio is established.

By the way, if the system is down and downshifted to the third speed stage during high-speed running at the fourth speed stage or higher at the "M" position, there is a possibility that the engine will overrun. Therefore, in the present embodiment, the oil passage L1
An opening / closing valve 16 is provided at 7 so as to be switchable between a right open position (position shown) for opening the oil passage L17 and a left closed position for closing the oil passage L17. And the on-off valve 16
Is pressed toward the open position by a spring 16a.
Is connected to an oil passage L7 connected to the first brake B1 that is engaged when the second speed is established, for example, when the second speed is established, and the first brake B1 is engaged when the second speed is established. B
The on / off valve 16 is switched to the closed position against the spring 16a by the hydraulic pressure of 1. An annular groove 16c communicating with the oil passage L2 at the closed position is formed in the on-off valve 16, and the land diameter on the left side of the annular groove 16c is made larger than the land diameter on the right side, and the on-off valve 16 is closed once. When the position is switched to the position, the line pressure input from the oil passage L2 to the annular groove 16c exerts a pressing force to the left of the difference between the left and right land diameters, and the pressing force affects the hydraulic pressure of the first brake B1. Regardless, the on-off valve 16 is kept at the closed position.

According to the above configuration, when the vehicle starts at the "D" position and the "M" position and the second speed is established, the on-off valve 16 is switched to the closed position, and thereafter the "D" position and the "M" The on-off valve 16 is kept in the closed position as long as the
Signal pressure from the second solenoid valve 7 ₂ to the oil chamber 15c of the switching valve 15 is not input. Thus, even if the system goes down at the "M" position, the switching valve 15 does not switch to the second switching position. When the system goes down, the fifth speed is established, and when the system goes down during high-speed traveling, the system goes down to the third speed. There is no shift. Also, even if the on-off valve 16 is switched to the closed position,
If it is set to the “N” position, the oil passage L2 is open to the atmosphere,
The on-off valve 16 returns to the open position by the urging force of the spring 16a.
Thus, when the system is down, once the position is changed to the "N" position and then to the "M" position, the switching valve 15 is switched to the second switching position, and the third gear is established as described above. M "
The gear can be shifted to the fifth speed and the third speed by the range switching operation.

The "R" position, the second brake B2 as described above is connected at all times, the reverse stage is established by connecting the third clutch C3 by oil from the third shift control valve 6 _3.

The third clutch C3 is shared by the third speed, the fifth speed, and the reverse speed.
3.4118 in the first gear, 1.9344 in the second gear, 1.4109 in the third gear, 1.0000 in the fourth gear, 0.7 in the fifth gear
239, 0.6126 at 6th gear, 3.9819 at reverse gear
When the planetary gears 2 ₁ , 2 ₂ , 2 ₃ are configured so that
The ratio of the torque assigned to the third clutch C3 to the input shaft torque (torque input to the input shaft 1a) is 0.3 at the third speed.
6815, 0.4579 at 5th gear, 2.518 at reverse gear
It becomes 5. Therefore, the hydraulic pressure range (connection start range) where the third clutch C3 starts to be engaged during the gear shift is considerably longer than when shifting to the third speed or the fifth speed when the accelerator is immediately depressed when switching to the "R" position. Get higher. The hydraulic pressure of the third clutch C3 is
In response to a signal pressure from the third solenoid valve 7 ₃ as described above but is pressed third regulated by a shift control valve 6 _3, the third solenoid valve 7 ₃ To ensure by pressure adjustment precision over the high pressure zone There is no choice but to make it very large.

[0038] Therefore, in this embodiment, the accumulator 19 while interposed in an oil passage L6 between the third shift control valve 6 ₃ and the third clutch C3, the orifice 17 and the oil discharge check valve 18 in parallel And an oil passage L2 is connected to the back pressure chamber 19a of the accumulator 19. Also,
The oil pressure from the oil passage L2 is input to the regulator 8 as the oil pressure that presses the oil pressure to the leak side. At the “R” position where the oil passage L2 is opened to the atmosphere, the line pressure is changed to the “D” position and the “M” position. Is set to a value PLR that is higher than the value PLF at. Here, the accumulator 19 has risen to a value exceeding the combined force of the hydraulic pressure of the oil passage L6 and the biasing force of the back pressure spring 19b arranged in a state where the internal pressure of the back pressure chamber 19a is pre-compressed in the back pressure chamber 19a. Sometimes, the piston 19c of the accumulator 19 retreats and the pressure accumulating action is started. In the “D” position and the “M” position, the back pressure chamber 1
Since the line pressure PLF is input to 9a via the oil passage L2, the accumulation start pressure becomes a value obtained by adding the oil pressure PS for the initial urging force of the back pressure spring 19b to the PLF, and the oil pressure in the oil passage L6 is equal to or higher than PLF. Accumulator 1
9 is blocked. On the other hand, at the "R" position, the back pressure chamber 19a is opened to the atmosphere via the oil passage L2 and the manual valve 5, so that the accumulation start pressure becomes the hydraulic pressure PS corresponding to the initial urging force of the back pressure spring 19b. The hydraulic pressure of L6 is PS
When the above occurs, the pressure accumulating action is performed according to the characteristic shown by the line a in FIG. If the received torque of the third clutch C3 is small when the engine is in a low load state when switching to the "R" position, the connection start area of the third clutch C3 is relatively low in pressure, and the PS is higher than the connection start area. Is pre-compressed so as to increase the pressure.

In this embodiment, the third shift control valve 6
_The oil passage L18 branched from the oil passage L9 into the oil chamber 6d of No. 3
And the oil passage L15 via a shuttle valve 20,
Via the oil passage L18 when the line pressure is input to the oil chamber 6d, the third shift control valve 6 ₃ is to be switched to the serving fully opened oil supply position in the "R" position. Oil passage L1
An opening / closing valve 21 which is switchable between a right open position to open the oil passage L18 and a left closed position (the position shown) to shut off the oil passage L18 is provided at 8. And on-off valve 2
1 is pressed toward the closed position by a spring 21a, and the on-off valve 2
1 the left end oil chamber 21b, connects the oil passage L19 on the output side of the sixth solenoid valve 7 ₆ openable to enter Mojireta pressure. Sixth solenoid valve 7 ₆ is normally closed, the electronic control circuit 11
By the time you open the sixth solenoid valve 7 ₆ by energizing the solenoid 7a, closing valve 21 is input the modulator pressure to the oil chamber 21b is switched to the open position, the third shift control valve 6 ₃ fully open Is switched.

The control mode at the "R" position includes:
As shown in FIG. 5, normally open second solenoid valve 7 ₂ of energized all closed current and a third electromagnetic valve 7 _3, the hydraulic engaging elements other than the second brake B2 C1, C2, C3, B1 to and inhibitor mode for stopping the fuel supply, and a third solenoid valve 7 ₃ oil pressure regulating pressure regulating pressure mode of the third clutch C3 by controlling the current supplied to while energizing all closed current second solenoid valve 7 ₂ , there is a line pressure mode for opening this sixth by energizing the solenoid valve 7 ₆ while energizing all closed current second solenoid valve 7 _2, 6
These modes are selected according to the program shown in FIG.

To describe this in detail, first, at step S1, it is determined whether or not the vehicle is at the "R" position. If the vehicle is not at the "R" position, the process proceeds to step S2 and the vehicle speed V is increased to a predetermined value YV ( For example, if V ≧ YV, the inhibitor flag FINH is set to 1 in step S3, and if V <YV, FINH is determined in step S4.
Is reset to 0. Further, the process proceeds from step S3 or S4 to step S5 to reset the line pressure flag FPL to 0, and then sets the remaining time TM of the subtraction timer to a predetermined time YTM (for example, 5 seconds) in step S6. ,
One process ends.

If it is determined in step S1 that the position is the "R" position, the flow advances to step S7 to determine whether FINH has been reset to 0.
In step S8, it is determined whether or not the vehicle speed V is equal to or higher than YV.
If <YV, FINH is reset to 0 in step S9, and the process proceeds to step S10. If it is determined in step S7 that FINH = 0, the process directly proceeds to step S10.

In step S10, it is determined whether or not the throttle opening TH as an engine load is equal to or greater than a predetermined value YTH. YTH is set to a value (for example, an opening degree) such that the engagement start area of the third clutch C3 becomes equal to or higher than the above PS when the output torque of the engine increases. And TH ≧ YT
If H, the line pressure flag FPL is set in step S11.
Is set to 1, and the process proceeds to step S12. Also, S
When it is determined in step 8 that V ≧ YV, or when it is determined in step S10 that TH <YTH, the process directly proceeds to step S12.
Proceed to step.

In step S12, it is determined whether or not FINH has been reset to 0. If FINH = 0, the process proceeds to step S13, where it is determined whether or not FPL has been reset to 0. If it is 0, S14
To determine whether or not the remaining time TM of the timer has become 0, that is, a predetermined time Y from the point of time of switching to the "R" position.
It is determined whether or not TM has elapsed, and if not, S
Proceed to step 15 to select the pressure regulation mode. Also,
When it is determined in step S13 that FPL = 1,
If TM = 0 is determined in step 14, the flow proceeds to step S16 to select the line pressure mode. If FINH = 1 is determined in step S12, the flow proceeds to step S17 to select the inhibitor mode. .

Thus, when switching to the "R" position, V≥YV
If so, the inhibitor mode is selected until V <YV, and refueling of the third clutch C3, that is, establishment of the reverse gear, is prevented. This is to prevent the transmission from being damaged due to the establishment of the reverse gear during forward traveling with V ≧ YV or more.

[0046] becomes V <YV, and, if made from the point of time of switching to the "R" position to TH <YTH, pressure regulating mode is selected, the third shift control valve 6 ₃ by the third solenoid valve 7 ₃ , The hydraulic pressure of the third clutch C3 is adjusted in accordance with the signal pressure. Here, if TH <YTH, the connection start area of the third clutch C3 becomes lower than the pressure accumulation start pressure PS of the accumulator 19, and the "D" position and the "M" position where the accumulation operation of the accumulator 19 is prevented. Like the time of shifting to the third speed and the fifth speed in the hydraulic pressure rise in the connection start region of the third clutch C3 the third shift control valve 6 ₃ controls without being affected by the accumulator 19, the shift Shock can be reduced.

[0047] becomes V <YV, and, at the TH ≧ YTH, is line pressure mode is selected and the third shift control valve 6 ₃ fully opened by opening the on-off valve 21 according to the opening of the sixth solenoid valve 7 ₆ The state is switched to the state, and the pressure oil of the line pressure is supplied to the oil passage L6. Here, when TH ≧ YTH, the third clutch C
The connection start area of No. 3 is the accumulation start pressure PS of the accumulator 19.
And the oil pressure of the third clutch C3 is quickly increased up to the accumulation start pressure PS, and thereafter, the increase in the oil pressure in the connection start region is buffered by the accumulation operation of the accumulator 19, thereby deteriorating the shift response. Shift shocks are reduced without occurring.

Even if TH <YTH, the line pressure mode is selected when the elapsed time from the point of switching to the "R" position reaches YTM. Thus, the third shift control valve 6 ₃ In the third solenoid valve 7 ₃ ON failure by the pressure regulating mode
Even if refueling via the control unit becomes impossible, the third clutch C3 can be refueled by establishing the reverse speed by switching to the line pressure mode.

In the above-described embodiment, the line pressure is input from the manual valve 5 to the back pressure chamber 19a of the accumulator 19 via the oil passage L2 at the "D" position and the "M" position, so that the accumulator 19 stores the pressure. I tried to prevent it,
The accumulator 19 is connected to the oil passage L6 via the on-off valve, the on-off valve is closed at the "D" position and the "M" position to prevent the accumulator 19 from accumulating pressure, and the on-off valve is opened at the "R" position to open the accumulator. It is also possible to have 19 accumulating actions. However, in the above embodiment, the pressure accumulation operation of the accumulator 19 is prevented at the “D” position and the “M” position,
Since the manual valve 5 can also be used as switching means for enabling the accumulator 19 to accumulate pressure at the "R" position, a special valve for the switching means is not required, which is advantageous in cost.

[0050]

As is apparent from the above description, according to the present invention, the increase of the hydraulic pressure in the connection start area of the hydraulic connection element is
Control is performed by a pressure regulating valve during a shift in which the connection start area is low, and is controlled by an accumulator during a shift in which the connection start area is high, so that shift shock can be reduced in any shift.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of an example of a transmission to which the device of the present invention is applied.

FIG. 2 is a hydraulic circuit diagram of an example of the device of the present invention.

FIG. 3 is a diagram showing a connection state of a hydraulic connection element and an energized state of a solenoid valve when each forward speed is established.

FIG. 4 is a graph showing a pressure accumulation characteristic of an accumulator.

FIG. 5 is a diagram showing an energized state of a solenoid valve in each reverse control mode.

FIG. 6 is a flowchart showing a reverse control program.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Automatic transmission C3 3rd clutch (hydraulic connection element) 5 Manual valve (1st switching means) 6 ₃ 3rd transmission control valve (pressure regulating valve) 7 ₃ 3rd solenoid valve (solenoid valve) 7 ₆ 6th solenoid valve (Second switching means) 19 Accumulator (second switching means) 21 On-off valve (second switching means)

Claims (2)

[Claims] An oil pressure coupling element shared by at least two first and second gears is provided, and a ratio of a torque received by the oil pressure coupling element to an input shaft torque is set to a second value in the first gear. A control device for an automatic transmission set to be higher than a shift speed, comprising a pressure regulating valve that regulates a hydraulic pressure supplied to the hydraulic connection element according to a signal pressure from an electromagnetic valve, wherein the hydraulic pressure is An accumulator connected to an oil passage between a connection element and the pressure regulating valve; and a shift that establishes the second shift stage, prevents a pressure accumulation operation of the accumulator, and performs a shift that establishes the first shift stage. A control device for an automatic transmission, comprising: first switching means for enabling the accumulator to accumulate pressure; and second switching means for switching the pressure regulating valve to a fully open state. 2. A control device for an automatic transmission including a predetermined hydraulic connection element for establishing a predetermined gear position, wherein the control apparatus adjusts a hydraulic pressure supplied to the hydraulic connection element in accordance with a signal pressure from a solenoid valve. An accumulator that is connected to an oil passage between the hydraulic connection element and the pressure regulating valve, and that performs a pressure accumulation operation only when a hydraulic pressure supplied to the hydraulic connection element becomes a predetermined value or more, Switching means for switching the pressure regulating valve to a fully open state at the time of gear shifting for establishing the gear position and when the engine load is equal to or more than a predetermined value.