JPH0712210A - Shift control device of automatic transmission - Google Patents

Abstract

PURPOSE:To prevent racing of an engine due to simultaneous release of both frictional elements at speed change of up-shift, in an automatic transmission in which the fastening pressure of a frictional element for selecting a low speed step is applied on the release side of a frictional element for selecting a high speed step in order to prevent interlock. CONSTITUTION:At speed change of 2 3 up-shift performed by changeover from a second brake S/B to a band brake B/B, a controller 60 delays removal of low speed step selecting pressure PS/B due to OFF of a solenoid valve 38, until a moment in which high speed step selecting pressure PB/B reaches the setting value and a pressure switch 62 is ON. Hereby, after slidingly fastening of the band brake B/B, the second brake S/B is released, and hence the period of simultaneous release of both brakes can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic gear shift, which is adapted to appropriately perform the shift change at the time of an upshift shift by changing the engagement of a low speed gear selecting friction element to a high speed gear selecting friction element. The present invention relates to a shift control device for a machine.

[0002]

2. Description of the Related Art An automatic transmission selects a predetermined gear stage by selectively hydraulically operating (engaging) various friction elements (clutch, brake, etc.), and changes the friction element to be engaged to change to another gear stage. It is configured to shift.

Therefore, depending on the type of gear shifting, it is necessary to disengage one of the low speed gear selection friction element and the high speed gear selection friction element, and at the same time, engage the other so-called friction element change.

By the way, in order to simplify the shift control hydraulic circuit, an automatic transmission in which the operating pressure of each friction element is supplied and discharged by individual valves to perform a predetermined shift is an A604E manufactured by Chrysler, Inc. of the United States. It has been developed as found in automatic transmissions.

However, when the friction elements to be replaced during gear shifting are engaged together as described above, the gear transmission mechanism of the automatic transmission is interlocked together with the fastening and holding of other friction elements. When adopting a shift control system similar to that of the above-mentioned A604E type automatic transmission manufactured by US Chrysler Co., Ltd. in such an automatic transmission, the control system of the valve is a friction element for selecting a low speed stage and a selection for a high speed stage. There is a risk of failure that must be avoided, such as fastening both friction elements.

[0006] Therefore, RL4 under development and practical use by the present applicant.
It is conceivable that the circuit configuration shown in FIG. 4 is made by using the simultaneous engagement prevention circuit technology for the high clutch and the band brake in the F02 type automatic transmission. In this figure, L
/ F is a friction element for selecting a low speed stage, L / V is a working pressure supply / discharge valve for the friction element, H / F is a friction element for selecting a high speed stage, and H / V is a working pressure supply / discharge valve for the friction element. . Supply / discharge valve L / V, H /
V is electronically controlled, and the line pressure is supplied to the corresponding friction elements as operating pressures P ₁ and P ₂ to the circuits L / K and H / K. Then, the friction element for selecting the low speed stage L /
The working pressure P ₁ of F provided to contact the circuit R / K for feeding to the friction element H / F for the high speed stage selected, the tie circuit R / operation from K pressure P ₁ of the high-speed stage selection for the friction element H / It acts on F in the opposite direction to the working pressure P ₂ .

According to this structure, the low speed stage can be selected by supplying the operating pressure P ₁ from the valve L / V to the friction element L / F and engaging the friction element. In this low speed stage selected state, even if the operating pressure P ₁ reaches the friction element H / F and the valve H / V supplies the operating pressure P ₂ to the friction element H / F, a friction is generated. It is possible to prevent the element H / F from being fastened and thus prevent an interlock state in which both friction elements are fastened simultaneously.

[0008]

However, in such a speed change control device, both friction elements are shown in FIG. 5 in the upshift speed change performed by changing over from the low speed gear selection friction element to the high speed gear selection friction element. May be controlled to change.

That is, at the time of this gear shift, the low speed stage selection pressure P
₁ is eliminated and the high-speed stage selection pressure P ₂ is generated, but the low-stage stage selection pressure P ₁ is eliminated before the engagement of the friction element H / F by the high-stage stage selection pressure P ₂ is started. This may cause the release of the friction element L / F. In this case, there will be a period when both friction elements are released at the same time,
During this period, the engine is idling as is apparent from the change in the engine speed Ne, which causes a large shift shock as apparent from the waveform of the transmission output torque To.

According to the present invention, while monitoring the operating pressure of the high speed stage selecting friction element, the release of the low speed stage selecting friction element is delayed until the operating pressure reaches a predetermined value so that both friction elements are released. The purpose is to eliminate the above-mentioned problem by ensuring that there is no such period.

[0011]

To this end, the speed change control device of the present invention comprises a low speed gear selecting friction element and a high speed gear selecting friction element, and the operating pressures of these friction elements are supplied and discharged by individual valves. It is possible to fasten the friction element for selecting the low speed stage by operating pressure from the corresponding valve, and to select the low speed stage by compensating the released state of the friction element for selecting the high speed stage by the operating pressure to prevent interlock. The high-speed stage selecting friction element is fastened by the operating pressure from the corresponding valve, and the low-speed stage selecting friction element is released by removing the operating pressure associated with the state switching of the corresponding low-speed stage. In an automatic transmission adapted to perform an upshift shift from a high speed to a high speed, a high speed selection pressure detecting means for detecting an operating pressure of the friction element for selecting a high speed and a high speed selection detected by the means. To the working pressure of the friction element reaches the set value, is provided with a low-speed stage selection excluder dividing delaying means for delaying the status switching of the valve.

[0012]

In the automatic transmission, the friction element for selecting the low speed stage is engaged by the operating pressure from the corresponding valve, and the operating pressure compensates the released state of the friction element for selecting the high speed stage to prevent the interlock. Is selected and the friction element for selecting the high speed stage is engaged by the operating pressure from the corresponding valve, and the friction element for selecting the low speed stage is released by eliminating the operating pressure associated with the state switching of the corresponding valve to release the low speed stage to the high speed stage. Can be upshifted to.

During the upshift, the high speed stage selection pressure detecting means detects the operating pressure of the high speed stage selecting friction element, and the low speed stage selecting pressure eliminating delay means detects the high speed stage selecting friction element detected by the means. The state switching of the valve is delayed until the operating pressure reaches the set value. Therefore, it is possible to eliminate the period when both friction elements are released at the same time,
It is possible to prevent idling of the engine speed and a large shift shock accompanying this.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 and 2 show a gear shift mechanism and a shift hydraulic circuit of an automatic transmission including a shift control device according to an embodiment of the present invention.

First, to explain the gear shift mechanism of FIG. 2,
It has input / output shafts I and O coaxially, and three planetary gear sets 3, 4, and 5 are coaxially interposed between these input / output shafts. The planetary gear set 3 is a simple planetary gear set including a sun gear 3S, a ring gear 3R, a plurality of pinions 3P meshed with these gears, and a carrier 3C that rotatably supports the pinions, and the planetary gear sets 4 and 5 are also respectively Sun gear 4S, 5
S, ring gears 4R, 5R, a plurality of pinions 4P, 5
A simple planetary gear set including P and carriers 4C and 5C.

As a frictional element that determines the power transmission paths of the above-mentioned three planetary gear sets, that is, the gears, 2 will be described below.
Provide 1 clutch and 3 brakes. Of the two clutches, the low clutch L / C is the sun gear 4S, 5
It is assumed that the rotating member serving as the connection of S is properly connected to the input shaft I, and the high clutch H / C is appropriately connected to the carrier 4C to the input shaft I. The input shaft I is attached to the sun gear 3S and the output shaft O is attached to the carrier 5C.

Of the three brakes, the band brake B / B corresponds to the friction element for selecting a high speed stage in the present invention, the ring gear 3R is appropriately fixed to the transmission case 6, and the second brake S / B is. A rotating member, which corresponds to the friction element for selecting a low speed stage in the present invention and serves as a coupling between the carrier 3C and the ring gear 4R, is appropriately fixed to the transmission case 6, and the reverse brake R / B is a coupling between the carrier 4C and the ring gear 5R. The rotating member to be mounted is appropriately fixed to the transmission case 6. In addition, the rotating member serving as the coupling between the carrier 4C and the ring gear 5R is further correlated with the transmission case 6 so as to be prevented from rotating in the direction opposite to the input rotation by the low one-way clutch L / OWC.

The above-described gear speed change mechanism selectively moves the friction elements in accordance with the logical table shown in the figure to perform the engaging operation (the circle indicates the operation), so that the forward drive speed is changed in the forward automatic speed change travel (D) range. The first to fifth speeds can be selected, and the reverse gear can be selected in the reverse travel (R) range. In addition, N and P in this table represent the neutral range and the parking range in which power transmission is not performed.

Next, the shift control hydraulic circuit shown in FIG. 2 for controlling the shift of the gear shift mechanism in accordance with the engagement logic of FIG. 1 will be described.

Reference numeral 11 denotes an oil pump, which converts the hydraulic oil from this to a predetermined line pressure and outputs it to the line pressure circuit 12.
On the other hand, the line pressure of the circuit 12 is reduced to a constant converter pressure by the torque converter regulator valve 13 and output to the circuit 14. The converter pressure of the circuit 14 is controlled by the lock-up control valve 15 in the flow direction toward the torque converter T / C, while it is supplied to the lubrication section 17 via the oil cooler 16, and further the electromagnetic switching lubrication control valve 18 is supplied.
It is supplied to the lubrication parts 19 and 20 under the flow rate control by.

The torque converter T / C is inserted between the input shaft I of the gear transmission mechanism shown in FIG. 1 and an engine (not shown) to transmit engine power to the input shaft I. The torque converter T / C has an AP and a release chamber RL, and when the lock-up control valve 15 is in the state shown in the drawing, the converter pressure of the circuit 14 flows in a direction from the former apply chamber AP to the latter release chamber RL.
Is in a lock-up state in which its input and output elements are directly connected, and the converter pressure in the circuit 14 is changed from the release chamber RL to the apply chamber A when the lock-up control valve 15 is in a state opposite to that shown in the drawing.
When flowing in the reverse direction toward P, the torque converter T / C is assumed to be in the converter state where the direct connection between its input and output elements is released.

On the other hand, the line pressure of the circuit 12 is reduced to a constant pilot pressure by the pilot valve 21, and the circuit 22
Is output to the lockup control valve 1
5 and the electromagnetic proportional lockup gain control valve 23. The lock-up gain control valve 23 regulates the pilot pressure of the circuit 22 and applies it to the lock-up control valve 15 as appropriate, and thereby the lock-up control valve 15 is added.
Shall cause the above-mentioned state changes.

The line pressure of the circuit 12 further reaches a manual valve 30, which is manually operated by the driver to a range corresponding to a desired driving mode. Here, as the range, a parking (P) range, a reverse running (R) range, a neutral (N) range, a forward automatic running (D) range, and a second speed engine brake (2) range are set. .

The manual valve 30 is 30 in the P and N ranges.
-P, 30-N ports are connected, all output circuits of the D range circuit 31, the 2 range circuit 32, and the R range circuit 33 are drained, and the R range is in the 30-R port connection state. , D range circuit 31 and 2 range circuit 3
2 is drained, the line pressure of the circuit 12 is supplied to the R range circuit 33, the port is connected to 30-D in the D range, and the line pressure of the circuit 12 is supplied to the D range circuit 31. The range circuit 32 and the R range circuit 33 are drained, the ports 30-2 are connected in two ranges, the line pressure of the circuit 12 is supplied to the D range circuit 31 and the 2 range circuit 32, and the R range circuit 3
Drain 3

The circuit 31 includes a duty solenoid valve 34.
Is inserted into the circuit 35, the circuit 37 in which the duty solenoid valve 36 is inserted, and the circuit 39 in which the duty solenoid valve 38 is inserted. Each of the duty solenoid valves has a friction element operating hydraulic pressure that increases in proportion to the drive duty. Shall be output. The circuit 35 passes through the shuttle valve 40 and the circuit 41 together with the circuit 32, and the low clutch L / C.
It is connected to the 1st speed apply chamber 1A. The low clutch L / C has a 5th speed release chamber 5R in addition to the 1st speed apply chamber 1A and is engaged when pressure is supplied to the 1st speed apply chamber 1A. When the pressure is also supplied to the fifth-speed release chamber 5R while being supplied, the low clutch L / C is released due to the pressure receiving area of both.

The circuits 37 and 38 are connected to an electromagnetic switching type 2-4 shift valve 42, which is OFF.
In the normal state, the circuits 43 and 44 are connected to the circuit 37,
Although the circuit 45 is connected to the circuit 39 and the circuit 45 is drained, the circuits 43 and 44 are respectively drained and the circuit 45 is connected to the circuit 39 in the ON state.

On the one hand, the circuit 43 is connected to the fifth clutch release chamber 5R of the low clutch L / C via the orifice 46 and on the other hand to the high clutch H / C together with the circuit 44 via the orifice 47 and the shuttle valve 48. In addition, the shuttle valve 49 is connected to the 5th speed / reverse apply chamber 5RA of the band brake B / B. The circuit 45 is also connected to the second brake S / B.

The band brake B / B has the third speed apply chambers 3A and 2 in addition to the fifth speed / reverse apply chamber 5RA.
There are 24th and 4th speed release chambers, and each apply chamber 5R
It is assumed that the fastening operation is performed by the pressure supply to A and 3A, and the engagement is released by the pressure supply to the release chamber 24R in place of these. The third speed apply chamber 3A is connected to a circuit 51 extending from the line pressure circuit 12 and having a duty solenoid valve 50 inserted therein.
It is assumed that 0 outputs the friction element hydraulic fluid pressure that increases in proportion to the drive duty. Further, the second and fourth speed release chambers 24R are connected to the circuit 52 branched from the circuit 39.

The reverse circuit 33 is the NR accumulator valve 5.
While connecting to the reverse brake R / B via 3,
The band brake B / B is connected to the fifth speed / reverse apply chamber 5RA via the orifice 54 and the shuttle valve 49.

Capacity control of oil pump 11, ON / OFF control of lubrication control valve 18, lock-up gain control valve 2
3 and duty solenoid valves 34, 36, 38, 5
0 duty control, 2-4 shift valve 42 ON, OF
The F control is executed by the controller 60 serving as the low speed stage selective pressure elimination delay means in the present invention, and therefore, the controller 60 has the selection range, the engine throttle opening degree, the vehicle speed, etc. necessary for the normal shift control. In addition to inputting input information 61 such as, the band brake engagement pressure (high speed stage selection pressure) P _{B / B} supplied to the chamber 3A of the band brake _{B / B} is detected particularly for the shift control according to the present invention. A signal from a pressure switch (high speed stage selection pressure detecting means) 62 which is turned on when this becomes a set value P _S (see FIG. 3) is input.

The shifting operation of the above embodiment will be described below. The P (N) range driver wishes to park or stop, and the manual valve 30
This valve drains all of the output circuits 31, 32, and 33 while the controller is in the P range or the N range, and the controller 60 sets the drive duty of the duty solenoid valve 50 to 0% to set the pressure of the circuit 51 to 0. I have to. Therefore, all the friction elements are deactivated, and as is clear from the logical table of FIG. 1, the gear transmission mechanism of the same figure is in a neutral state in which power is not transmitted, and a parking / stopping state can be obtained as desired. it can.

When the D range driver desires forward automatic shifting, the manual valve 3
While the 0 is in the D range, this valve outputs the line pressure of the circuit 12 only to the circuit 31.

(First speed) Here, the controller 60 is
When it is determined from the input information 61 that the first speed should be selected, the drive duty of the duty solenoid valve 34 is set to a predetermined value, and the corresponding operating pressure is passed through the circuit 35, the shuttle valve 40, and the circuit 41 to the chamber of the low clutch L / C. Supply to 1A.

Therefore, the controller 60 sets the drive duty of the duty solenoid valves 36, 38, 50 to 0%.
Then, the pressure of the circuits 37, 39, 51 is set to 0, and 2-4
The shift valve 42 is off. Therefore, no pressure is supplied to the chamber 5R of the low clutch L / C, and of course no pressure is supplied to the high clutch H / C, the second brake S / B, or the band brake B / B. Further, since the manual valve 30 drains the circuit 33, no pressure is supplied to the reverse brake R / B.

Therefore, only the low clutch L / C is engaged, and as is clear from the logical table of FIG. 1, the gear shift mechanism of the same figure has a low one-way clutch L / OW.
In combination with the engagement of C, the first speed can be selected and the power transmission at this gear can be performed.

By the way, when the selection of the first speed is accompanied by the switching of the manual valve 30 from the N range to the D range, the controller 60 gradually increases the drive duty of the duty solenoid valve 34 during the gear shift to set the low speed to the low level. The engagement shock of the clutch L / C, that is, the N → D select shock is reduced.

After the shift is completed, the driving duty ratio of the duty solenoid valve 34 is set to 100% to set the operating pressure of the low clutch L / C to the maximum value equal to the line pressure to prevent the clutch from slipping. .

(Second speed) When the controller 60 determines from the input information 61 that the second speed should be selected, the drive duty of the duty solenoid valve 34 is maintained at 100% and the low clutch L / C is engaged. As it is, the 2-4 shift valve 42 is switched to ON, the circuits 43 and 44 are drained, respectively, and the circuit 45 is connected to the circuit 39. At the same time, the drive duty of the duty solenoid valve 38 is gradually increased, The second brake S / B is gradually engaged as the pressure (low speed stage selection pressure) P _{S / B} rises.

The engagement of the second brake S / B is as follows.
In combination with maintaining the engaged state of the low clutch L / C, FIG.
As is clear from the logical table of,
Switch to the selected state and change the automatic transmission from first speed to second speed
And upshift can be shifted. Also, this strange
At high speed, drive duty of the duty solenoid valve 38
Gradually increase the pressure in the circuits 39 and 45.
Therefore, gradually engage the second brake S / B.
Therefore, shift shock can be reduced. Change
In the second speed selection state, the low speed stage selection pressure P in the circuit 45 is
_{S / B}Through the circuit 52, the release of the band brake B / B
24R, the solenoid valve 50 drive
The application room of the band brake B / B due to the occurrence of a utility
Pressure P to 3A _{B / B}Even if the band is supplied
Make sure that the brake B / B is not engaged. Or
The second clutch with the low clutch L / C engaged.
Both the brake S / B and band brake B / B are fastened together.
Prevents the gear shifting mechanism of FIG. 1 from interlocking
can do.

(Third speed) When the controller 60 determines from the input information 61 that the third speed should be selected, the drive duty of the duty solenoid valve 34 is maintained at 100% and the low clutch L / C is in the engaged state. As it is, again 2-4
While the ON state of the shift valve 42 is maintained, the drive duty of the duty solenoid valve 38 is set to 0% to switch the second brake S / B to release, and at the same time, the drive duty of the duty solenoid valve 50 is gradually increased by the circuit 51. From band brake B / B apply room 3
The band brake B / B is gradually engaged by increasing the pressure (high speed stage selection pressure) P _{B / B} to A.

This switching from the second brake S / B to the band brake B / B is combined with the holding of the engaged state of the low clutch L / C, as is clear from the logical table of FIG. Switch the gear shift mechanism to the third speed selection state,
The automatic transmission can be upshifted from the second speed to the third speed. At the time of this shift, the drive duty of the duty solenoid valve 50 is gradually increased so that the circuit 51
The pressure inside is gradually increased, so the band brake B /
Since B is gradually engaged, shift shock can be reduced.

Incidentally, in this 2 → 3 upshift,
As shown in FIG. 3, the controller 60 uses the high-speed stage selection pressure P
_{B / B}Is the set value P_SAnd the pressure switch 62 is turned on.
Instant t ₁ To low speed stage by turning off solenoid valve 38
Selective pressure P_{S / B}Delay the elimination of. Because of this, the conclusion of the figure
As shown in the force waveform, P_{B / B}= P_SBecome a band breaker
Second brake S / B after key B / B is slip-joined
Will be released and both brakes will be released
It is possible to eliminate the period of stay. Therefore, the engine of the figure
From the waveforms of the engine speed Ne and the transmission output torque To.
As you can see, the engine is running dry and the gear shifting
You can avoid Kock.

(Fourth speed) When the controller 60 determines from the input information 61 that the fourth speed should be selected, the drive duty of the duty solenoid valve 34 is maintained at 100% and the low clutch L / C is engaged. As it is, the drive duty of the duty solenoid valve 50 is set to 0% and the band brake B / B is switched to the release state, at the same time, the 2-4 shift valve 42 is switched to the OFF state, and the drive duty of the duty solenoid valve 38 is gradually increased. , Circuit 3
By increasing the pressure from 9,44 to the high clutch H / C, the high clutch H / C is gradually engaged.

The changeover from the band brake B / B to the high clutch H / C in combination with the holding of the engaged state of the low clutch L / C is apparent from the logical table of FIG. The gear shift mechanism can be switched to the fourth speed selection state, and the automatic transmission can be upshifted from the third speed to the fourth speed. At the time of this shift, the drive duty of the duty solenoid valve 38 is gradually increased so that the circuits 39, 4
The pressure in 4 is gradually increased, so that the high clutch H /
Since C is gradually engaged, shift shock can be reduced.

(Fifth speed) When the controller 60 determines from the input information 61 that the fifth speed should be selected, the above-mentioned fourth speed is selected.
In the speed selection state, the drive duty of the duty solenoid valve 38 is set to 0% and the drive duty of the duty solenoid valve 36 is gradually increased. The drive duty of the duty solenoid valve 38 is 0% when the circuits 39 and 44 are
From the high clutch H / C to the high clutch H / C, the increase in the drive duty of the duty solenoid valve 36 causes the high clutch H / C from the circuits 37 and 43 and the orifice 47.
Since the operating pressure is newly supplied to C, the high clutch H / C maintains the engaged state.

On the other hand, the pressures of the circuits 37 and 43 are supplied to the release chamber 5R of the low clutch L / C via the orifice 46 and the band brake B via the shuttle valve 49.
Reach 5RA of the apply chamber of / B. Here, the low clutch L / C continues to be supplied with pressure to the apply chamber 1A, but the pressure receiving area in the release chamber 5R is larger than the pressure receiving area in the apply chamber 1A.
It is released by the pressure of. In addition, band brake B / B
Are fastened by the pressure reaching the apply chamber 5RA.

Therefore, the low clutch L / C is released and the band brake B / B is engaged while the high clutch H / C is maintained in the engaged state. The change to / B coupled with maintaining the engaged state of the high clutch H / C,
As is clear from the logical table of FIG. 1, the gear transmission mechanism of the same figure is switched to the fifth speed selection state, and the automatic transmission is changed from the fourth speed to the fifth speed.
It is possible to shift upshift to high speed. During this shift, the drive duty of the duty solenoid valve 36 is gradually increased to gradually increase the pressure in the circuits 37 and 43, and thus the band brake B / B is gradually engaged, so that shift shock is reduced. be able to.

When the R range driver desires backward traveling and sets the manual valve 30 to the R range, the circuits 31 and 32 are drained, and the line pressure of the circuit 12 is output only to the circuit 33. Circuits 31, 32
Drains are low clutch L / C, high clutch H / C,
And the second brake S / B is released to release them, and the line pressure to the circuit 33 is set to the NR accumulator valve 5
After reaching the reverse brake R / B via 3 and engaging and actuating the reverse brake R / B, the reverse brake R / B is reached through the N-R accumulator valve 53 and the orifice 54 to the apply chamber 5RA of the band brake B / B and the band brake B / B is engaged. Activate.

As for the engagement of the reverse brake R / B and the band brake B / B, as is apparent from the logic table of FIG. 1, the gear transmission mechanism of FIG.
The vehicle can be run backwards. At this time, N-
The R accumulator valve 53 can gradually increase the engagement pressure of the reverse brake R / B and the band brake B / B, and reduce these engagement shocks, that is, NR select shocks.

In any case, according to the structure of the above embodiment, the shift valve is only one of the 2-4 shift valves 42, and the reliability of the shift control system can be improved.
The control valve can be downsized, and the use of the duty solenoid valve 34 for the engagement control of the low clutch L / C can improve the accuracy of the low pressure operation of the clutch.

[0051]

As described above, the shift control device of the present invention is defined by claim 1.
As described in (1), a low speed gear selection friction element (second brake S / B in the illustrated example) and a high speed gear selection friction element (band brake B / B in the illustrated example) are provided, and the operating pressure (P _{S / B} , P _{B / B} ) can be supplied / discharged by individual valves (solenoid valves 38, 50 in the illustrated example), and the low speed stage selecting friction element (S / B) from the corresponding valve (38). working pressure (P S _{/ B)} by the working pressure (P S _{/ B)} interlock preventing the high speed stage selected friction element (B / B) low speed stage to compensate for the released state together with fastening (shown example Then, the second speed) is selected, the high speed selection friction element (B / B) is engaged by the operating pressure (P _{B / B} ) from the corresponding valve (50), and the low speed selection friction element ( _{B / B} ) is connected. the S / B) the elimination of the hydraulic pressure caused by the state switching of said corresponding valves _{(38) (P S / B} ) Upon release to perform upshift from the low speed stage (second speed) to a high-speed gear (third speed), detects the operating pressure of the high-speed stage selection friction element (B / B) (P B / B) Then, since the state switching of the valve (38) is delayed until it reaches the set value (P _S ), the low speed stage is selected after the high speed stage selecting friction element (B / B) is slip-engaged. Since the selection frictional element (S / B) is released, the period in which both of these frictional elements are released can be eliminated, and idling of the engine and shift shock associated therewith can be avoided.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a gear shift mechanism of an automatic transmission including a shift control device according to an embodiment of the present invention.

FIG. 2 is a shift control hydraulic circuit diagram of the same automatic transmission.

FIG. 3 is a 2 → 3 shift operation time chart generated by shift control executed by the controller of FIG. 2;

FIG. 4 is a hydraulic circuit diagram showing a conventional shift control device.

FIG. 5 is an operation time chart of the conventional shift control device.

[Explanation of symbols] I Input shaft O Output shaft L / C Low clutch H / C High clutch B / B Band brake (Friction element for high speed selection) S / B Second brake (Friction element for low speed selection) R / B Reverse brake 3 Planetary gear set 4 Planetary gear set 5 Planetary gear set 11 Oil pump 13 Torque converter regulator valve 15 Lockup control valve 18 Lubrication control valve 21 Pilot valve 23 Lockup gain control valve 30 Manual valve 34 Duty solenoid valve 36 Duty solenoid valve Valve 38 Duty solenoid valve 42 2-4 Shift valve 50 Duty solenoid valve 53 NR accumulator valve 60 Controller (low speed stage selection pressure elimination delay means) 62 Pressure switch (high stage selection pressure detection means)

Claims (1)

[Claims] 1. A valve comprising a low speed stage selecting friction element and a high speed stage selecting friction element, wherein the operating pressures of these friction elements can be supplied and discharged by individual valves, and the low speed stage selecting friction element corresponds to said valve. The high pressure stage friction element is engaged with the high pressure stage friction element for compensating the release state of the high speed stage selection friction element to prevent interlock by the operation pressure, and the high speed stage selection friction element is used as a corresponding valve. The automatic shift is performed by engaging the operating pressure from the above and releasing the friction element for selecting the low speed stage by eliminating the operating pressure associated with the switching of the state of the corresponding valve to perform the upshift shift from the low speed stage to the high speed stage. In the machine, a high speed stage selection pressure detecting means for detecting the operating pressure of the high speed stage selecting friction element, and the valve state until the operating pressure of the high speed stage selecting friction element detected by the means reaches a set value. Shift control device for an automatic transmission, characterized in that a low-speed stage selection excluder dividing delaying means for delaying the switching.