JP3085030B2 - Transmission control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission in which upshifting is appropriately performed at the time of upshifting by switching from a low speed gear selecting element to a high 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 by selectively operating various friction elements (clutches, brakes, etc.) with hydraulic pressure (engagement), and changes to another gear by changing the friction element to be engaged. It is configured to perform a shift.

Therefore, depending on the type of gear shifting, it is necessary to replace a so-called friction element in which one of the friction element for selecting the low-speed gear and the friction element for selecting the high-speed gear is released and the other is fastened.

In order to simplify the shift control hydraulic circuit, an automatic transmission which performs a predetermined shift by supplying and discharging the operating pressure of each friction element by an individual valve is known as A604E manufactured by Chrysler, USA. It has been developed as seen in type automatic transmissions.

[0005] However, if the friction elements to be changed during the gear shift are fastened together as described above, the gear transmission mechanism of the automatic transmission may be interlocked together with the holding of the other friction elements. In the case where such an automatic transmission adopts the same shift control method as that of the above-mentioned A604E type automatic transmission manufactured by Chrysler Co., Ltd., the control system of the valve includes a friction element for selecting a low-speed gear and a friction element for selecting a high-speed gear. There is a risk that a failure that must be avoided, such as fastening both friction elements, may occur.

Accordingly, the applicant of the present invention has been developing and using the RL4.
It is conceivable that the circuit configuration shown in FIG. 4 is made by using a simultaneous clutch prevention circuit technology of 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 gear, L / V is a working pressure supply / discharge valve for the friction element, H / F is a friction element for high speed gear selection, 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 circuits L / K and H / K as operating pressures P ₁ and P ₂ to the corresponding friction elements as appropriate. Then, the friction element 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 / F acts in the opposite direction to the operating pressure P ₂ .

[0007] According to such a configuration, it is possible to select the low speed stage by supplying the operating pressure P ₁ from the valve L / V to friction elements L / F is entered into the friction element. In this low speed stage selection state, the operating pressure P ₁ also reaches the friction element H / F, and even if a failure occurs in which the valve H / V supplies the operating pressure P ₂ to the friction element H / F, the friction pressure is maintained. By preventing the elements H / F from being fastened, it is possible to prevent an interlock state in which the two friction elements are fastened simultaneously.

[0008]

However, in such a shift control device, when the upshift is performed by switching from the low speed gear selecting element to the high gear selecting friction element, both friction elements are shown in FIG. Switching control may be performed as follows.

That is, at the time of this shift, the low-speed stage selection pressure P
Eliminating the _1, but will be generated fast stage selection pressure P _2, even as long as to raise the interlock preventing action because the high speed stage selection pressure P ₂ of the low-speed stage selection pressure P ₁ is remaining friction since the fastening elements H / F can not be started normally performs first elimination of the low-speed stage selection pressure P _1, as shown in FIG. 5, then allow progress shifting raises the high speed stage selection pressure P ₂ Exercising. Therefore, before the engagement of the friction element H / F by the high-speed gear selection pressure P ₂ is started, the low-speed gear selection pressure P
₁ may be eliminated and cause release of the friction element L / F. In this case, there is a period during which both friction elements are simultaneously released, as is apparent from the fastening force waveform in FIG. 3, and during this period, the engine runs idle as is apparent from the change in the engine speed Ne. This causes a large shift shock as apparent from the waveform of the transmission output torque To. In order to solve this problem, the low-speed stage selection pressure P _{1 that} is changed by eliminating the preceding low-speed stage selection pressure P _1.
The monitor, which is believed to increase the high-speed stage selection pressure P ₂ when reduced to the set pressure, but the friction elements L / F
The set pressure for causing the release of the frictional force and the engagement of the friction element H / F to be performed at exactly the right timing is extremely limited, and setting is extremely difficult. Then, when the set pressure becomes lower than the preferable value due to the variation of the automatic transmission or a change over time, the friction element H / F is engaged after the friction element L / F is released. If the intended purpose cannot be achieved due to engine idling and the above set pressure becomes higher than a suitable value, the low speed stage selection pressure P
_{Since the value of 1} is high, the engagement of the friction element H / F cannot proceed even with the increase of the high speed stage selection pressure P ₂ , and the low speed stage selection pressure P ₁
There when reduced to some extent, while also stretch is engaged elevated continued high speed stage selection pressure P ₂ which is higher friction element H / F, to cause the generation of a new shift shock.

The present invention provides a low speed gear selecting friction element while monitoring the operating pressure of a high gear selecting friction element to be engaged, until the pressure reaches a value that allows the high speed gear selecting friction element to be slidably coupled. It is an object of the present invention to solve the above-mentioned problem by delaying the release of the friction element so that there is no period during which both friction elements are released.

[0011]

SUMMARY OF THE INVENTION To this end, a shift control device according to the present invention includes a friction element for selecting a low gear and a friction element for selecting a high gear, and the operating pressure of these two friction elements is supplied and discharged by individual valves. It is possible to fasten the friction element for selecting the low speed gear by the operating pressure from the corresponding valve and select the low gear by compensating the released state of the friction element for selecting the high gear to prevent interlock with the operating pressure. The high-speed gear selecting element is fastened by operating pressure from the corresponding valve, and the low-speed gear selecting friction element is released by removing the operating pressure accompanying the switching of the state of the corresponding valve to release the low-speed gear. High-speed gear selection pressure detecting means for detecting the operating pressure of the high-speed gear selection friction element, and high-speed gear selection detected by the means. A low-speed stage selection pressure elimination delay that delays the switching of the state of the valve corresponding to the low-speed stage selection friction element until the operating pressure of the friction element reaches a set value that enables the high-speed stage selection friction element to slide. Means.

[0012]

In the automatic transmission, the low speed gear is selected by operating the friction element for selecting the low gear, and the operating pressure is used to compensate the released state of the friction element for selecting the high gear to prevent interlock. And fastens the friction element for selecting the high-speed gear by the operating pressure from the corresponding valve, and releases the friction element for selecting the low-speed gear by eliminating the operating pressure accompanying the switching of the state of the corresponding valve to release the friction element from the low gear to the high gear. Upshift can be performed.

During the upshift, the high-speed gear selection pressure detecting means detects the operating pressure of the high-speed gear selection friction element, and the low-speed gear selection pressure elimination delay means detects the high-speed gear friction element detected by the above means. The switching of the state of the valve corresponding to the low-speed-selection friction element is delayed until the operating pressure reaches a set value that enables the high-speed-selection friction element to slip. It is therefore possible to compensate for the elimination of the operating pressure of the low speed gear selecting friction element after the operating pressure of the high gear selecting friction element reaches a set value that enables the high speed gear selecting friction element to be slidably coupled. Can be. By the way, as long as the operating pressure of the friction element for selecting the low-speed stage exists (before the operating pressure of the friction element for selecting the low-speed stage is eliminated), the operating pressure of the friction element for selecting the high-speed stage can be reduced due to the above-described interlock preventing action. Even when the above-mentioned set value is reached, the high-speed gear selection friction element is not slip-coupled, and therefore the timing at which the high-speed gear selection friction element actually starts to slip-couple is determined by the low-speed gear selection friction element. It can be governed by the elimination of the operating pressure, and when the friction element for selecting the low-speed gear is released by the elimination of the operating pressure, a sliding connection of the friction element for selecting the high-speed gear can be reliably produced. Therefore, it is possible to reliably eliminate the period in which the two friction elements are simultaneously released, and to prevent the engine speed from idling and the accompanying large shift shock from occurring. In particular, since the operating pressure of the friction element for selecting the high-speed gear to be fastened is monitored and the operating pressure of the friction element for selecting the low-speed gear is removed after reaching the set value, the set pressure is strict. It is not necessary that, as described above, as long as the value is such that the frictional element for high-speed step selection can be slip-coupled, the above-mentioned effects can be reliably achieved,
The trouble associated with the set pressure described above when monitoring the operating pressure of the low speed gear selecting element can be eliminated.

[0014]

Embodiments of the present invention will be described below 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, the gear transmission mechanism shown in FIG. 2 will be described.
This has input and output shafts I and O coaxially, and three planetary gear sets 3, 4, and 5 are coaxially interposed between the input and 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 rotatably supporting the pinions. Sun gear 4S, 5
S, ring gears 4R, 5R, plural pinions 4P, 5
A simple planetary gear set including P and carriers 4C and 5C.

As a power transmission path of the three planetary gear sets, that is, as a friction element for determining a shift speed, the following two components will be described.
There are three clutches and three brakes. Of the two clutches, the low clutch L / C is connected to the sun gears 4S, 5
It is assumed that the rotating member that becomes the connection of S is appropriately connected to the input shaft I, and the high clutch H / C appropriately connects the carrier 4C to the input shaft I. The input shaft I is connected to the sun gear 3S, and the output shaft O is connected to the carrier 5C.

Of the three brakes, the band brake B / B corresponds to a friction element for selecting a high-speed gear in the present invention, and 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 a friction element for selecting a low speed gear in the present invention and which connects the carrier 3C and the ring gear 4R is appropriately fixed to the transmission case 6, and the reverse brake R / B is connected to the carrier 4C and the ring gear 5R. Is appropriately fixed to the transmission case 6. It is to be noted that the rotating member forming the connection between the carrier 4C and the ring gear 5R is further correlated with the transmission case 6 so that the rotation in the opposite direction to the input rotation is prevented by the low one-way clutch L / OWC.

The above-described gear transmission mechanism selectively engages the friction elements according to the logical table shown in FIG. 1 (operations are indicated by circles), thereby enabling the automatic transmission in the forward automatic transmission (D) range. First to fifth speeds can be selected, and the reverse gear can be selected in the reverse travel (R) range. Note that N and P in this table represent a neutral range and a parking range in which power is not transmitted.

Next, a shift control hydraulic circuit shown in FIG. 2 for shifting the gear transmission mechanism according to the engagement logic shown in FIG. 1 will be described.

Reference numeral 11 denotes an oil pump which converts hydraulic oil to be supplied to a predetermined line pressure and outputs it to a 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 flow of the converter pressure in the circuit 14 is controlled by the lock-up control valve 15 to flow to the torque converter T / C while being supplied to the lubricating unit 17 via the oil cooler 16 and further to the electromagnetic open / close lubrication control valve 18.
Is supplied to the lubricating units 19 and 20 under the flow rate control by the controller.

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

On the other hand, the line pressure of the circuit 12 is reduced to a constant pilot pressure by the pilot valve 21 so that the circuit 22
Is output to the lock-up control valve 1
5 and an electromagnetic proportional lock-up gain control valve 23. The lock-up gain control valve 23 regulates the pilot pressure of the circuit 22 and appropriately applies the pilot pressure to the lock-up control valve 15, whereby the lock-up control valve 15 is controlled.
The above state change is caused.

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 the desired driving mode. Here, as the ranges, a parking (P) range, a reverse traveling (R) range, a neutral (N) range, an automatic forward traveling (D) range, and a second speed engine brake (2) range are set. .

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

The circuit 31 includes a duty solenoid valve 34
, A circuit 37 in which a duty solenoid valve 36 is inserted, and a circuit 39 in which a 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 is connected to the low clutch L / C via the shuttle valve 40 and the circuit 41 together with the circuit 32.
To the first-speed apply chamber 1A. The low clutch L / C has a fifth-speed release chamber 5R in addition to the first-speed apply chamber 1A, and is engaged when pressure is supplied to the first-speed apply chamber 1A. When the pressure is also supplied to the fifth-speed release chamber 5R while the low clutch L / C is released, the low clutch L / C is released due to the pressure receiving area of the two.

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

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

It should be noted that the band brakes B / B are provided in the third speed apply chambers 3A and 3A in addition to the fifth speed / reverse apply chamber 5RA.
It has a high-speed / four-speed release room 24R, and each application room 5R
The fastening operation is performed by the pressure supply to A and 3A, and is released by the pressure supply to the release chamber 24R instead. The third-speed apply chamber 3A is connected to a circuit 51 which extends from the line pressure circuit 12 and into which a duty solenoid valve 50 is inserted.
0 is assumed to output a friction element working fluid pressure that increases in proportion to the drive duty. The second-speed / fourth-speed release chamber 24R is connected to a circuit 52 branched from the circuit 39.

The retraction circuit 33 includes the NR accumulator valve 5
3 and connected to the reverse brake R / B
The orifice 54 and the shuttle valve 49 are connected to the fifth-speed / reverse apply chamber 5RA of the band brake B / B.

The displacement control of the oil pump 11, the ON / OFF control of the lubrication control valve 18, the 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 selection pressure elimination delay means in the present invention. Therefore, the controller 60 provides the controller 60 with a selection range necessary for normal shift control, an engine throttle opening, a vehicle speed, and the like. In addition to the input of the input information 61 such as, for example, for the shift control according to the present invention, the band brake engagement pressure (high-speed gear selection pressure) P _{B / B} supplied to the chamber 3A of the band brake _{B / B} is detected. A signal is inputted from a pressure switch (high-speed stage selection pressure detecting means) 62 which is turned on when this reaches a set value P _S (see FIG. 3) which enables the sliding coupling of the band brakes B / B.

The shifting operation of the above embodiment will now be described. When the P (N) range driver wants to park or stop, the manual valve 30
While the valve is in the P range or the N range, this valve drains all of the output circuits 31, 32, and 33, and the controller 60 sets the drive duty of the duty solenoid valve 50 to 0%, thereby reducing 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 FIG. it can.

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

(First speed) Here, the controller 60
If 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 applied to the low clutch L / C chamber via the circuit 35, the shuttle valve 40, and the circuit 41. 1A.

The controller 60 sets the drive duty of the duty solenoid valves 36, 38, 50 to 0%.
To set the pressure of the circuits 37, 39 and 51 to 0, and 2-4
The shift valve 42 is turned off. Therefore, no pressure is supplied to the chamber 5R of the low clutch L / C, and, of course, no pressure is supplied to any of the high clutch H / C, the second brake S / B, and 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 apparent from the logic table of FIG. 1, the gear transmission of FIG.
In conjunction with the engagement of C, the first speed can be selected, and power can be transmitted at this speed.

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 shift, and The engagement shock of the clutch L / C, that is, the N → D select shock is reduced.

After the shift is completed, the drive duty of the duty solenoid valve 34 is set to 100%, the operating pressure of the low clutch L / C is set to the same maximum value as the line pressure, and slip of the clutch is prevented. .

(Second speed) When the controller 60 determines that the second speed should be selected from the input information 61, the drive clutch of the duty solenoid valve 34 is maintained at 100% and the low clutch L / C is engaged. While the 2-4 shift valve 42 is turned ON, the circuits 43 and 44 are respectively drained, 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 applied by increasing the pressure (low-speed stage selection pressure) P _{S / B.}

The engagement of the second brake S / B is as follows.
In conjunction with maintaining the engaged state of the low clutch L / C, FIG.
As can be seen from the logical table of FIG.
Switch to the selected state and change the automatic transmission from first gear to second gear
And upshifting. Also, this change
At high speed, the drive duty of the duty solenoid valve 38
The pressure in the circuits 39 and 45 is gradually increased by gradually increasing the pressure.
Therefore, gradually apply the second brake S / B.
Therefore, the shift shock can be reduced. Change
In the second speed selection state, the low-speed stage selection pressure P
_{S / B}Is the release of the band brake B / B via the circuit 52
To the closing chamber 24R.
Applying room for band brake B / B
Pressure P to 3A _{B / B}Even if the band is supplied
The brake B / B is not applied. Or
When the low clutch L / C is engaged, the second
Brake S / B and band brake B / B are fastened together
To prevent the gear transmission mechanism of Fig. 1 from interlocking.
can do.

(Third speed) When the controller 60 determines that the third speed should be selected from the input information 61, the drive clutch of the duty solenoid valve 34 is kept at 100% and the low clutch L / C is engaged. While keeping the 2-4 shift valve 42 in the ON state, the drive duty of the duty solenoid valve 38 is set to 0% to switch the second brake S / B to release under the timing control described later, and the duty solenoid is switched. The drive duty of the valve 50 is gradually increased, and the circuit 51 applies the band brake B / B to the apply chamber 3.
By increasing the pressure (high-speed stage selection pressure) P _{B / B} to A, the band brake B / B is gradually engaged.

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

In this 2 → 3 upshift, the controller 60 sets the high-speed gear selection pressure P as shown in FIG.
_The instant t when B / B reaches the set value P _S enabling the band brake B / B to slide and the pressure switch 62 is turned on.
Low speed selection pressure P by turning off solenoid valve 38 until ₁
Delay _{S / B} elimination. Therefore, the high-speed stage selection pressure P _{B / B}
There can be compensated for low-speed stage selection pressure P _{S / B} is eliminated after reaching the set value P _S to enable sliding coupling of the band brake B / B. By the way, the low speed stage selection pressure P _{S / B}
(Low speed stage selection pressure P _{S / B} Before excluded there is initiated) because the above interlock preventing action, high speed stage selection pressure P _{B / B} band even reached the set value P _S insofar but present The timing at which the brakes B / B are not slip-coupled and therefore the band brakes B / B actually start to slip-lock can be governed by the elimination of the low speed selection pressure PS _{/ B} , and the second brake S / B is the low-speed stage selection pressure P
_When released by the elimination of the _{S / B} , the sliding connection of the band brakes B / B can be reliably generated. In other words, as shown by the waveform in FIG. 3, after the high speed gear selection pressure P _{B / B} becomes the set pressure P _S that enables the sliding coupling of the band brakes B / B, the low gear gear selection pressure P _{S / B} is eliminated. Then, the second brake S / B is released, and the band brake B / B is slid by the high speed selection pressure P _{B / B which} has reached the set value P _S. As a result, as apparent from the fastening force waveform of FIG. 3, the period in which the band brake B / B and the second brake S / B are simultaneously released can be reliably eliminated, and the engine speed Ne and the transmission shown in FIG. As is apparent from the waveform of the output torque To, it is possible to prevent the idling of the engine speed and the occurrence of a large shift shock associated therewith.

(Fourth speed) When the controller 60 determines that the fourth speed should be selected from the input information 61, the drive clutch of the duty solenoid valve 34 is kept at 100% and the low clutch L / C is engaged. At the same time, the drive duty of the duty solenoid valve 50 is set to 0%, the band brake B / B is switched to release, and 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 switching from the band brake B / B to the high clutch H / C, together with the holding of the engaged state of the low clutch L / C, as shown in the logical table of FIG. By switching the gear transmission mechanism to the fourth speed selection state, 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
4, the pressure in the high clutch H /
Since C is gradually engaged, shift shock can be reduced.

(Fifth speed) When the controller 60 determines that the fifth speed should be selected from the input information 61, the controller 60
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%.
, The pressure to the high clutch H / C disappears, but the increase in the drive duty of the duty solenoid valve 36 causes the high clutch H / C to be output 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 pressure of the circuits 37 and 43 is 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.
/ B reaches the application chamber 5RA. 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.
Released by the pressure of In addition, band brake B / B
Is fastened by the pressure that has reached the apply chamber 5RA.

Accordingly, the low clutch L / C is released and the band brakes B / B are engaged while the engaged state of the high clutch H / C is maintained, and the band clutch B / B is released from the low clutch L / C. / B, in conjunction with maintaining the engaged state of the high clutch H / C,
As is clear from the logic table of FIG. 1, the gear transmission shown in FIG. 1 is switched to the fifth speed selection state, and the automatic transmission is shifted from the fourth speed to the fifth speed.
Upshifting to high speed is possible. 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 to gradually apply the band brakes B / B, thereby reducing shift shock. be able to.

When the R range driver sets the manual valve 30 to the R range in order to reverse, 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
Drain of 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 reduced by the NR accumulator valve 5.
3, the reverse brake R / B is reached and actuated, and at the same time, it reaches the apply chamber 5RA of the band brake B / B via the NR accumulator valve 53 and the orifice 54, and the band brake B / B is engaged. Activate.

When the reverse brake R / B and the band brake B / B are engaged, as shown in the logic table of FIG. 1, the gear transmission mechanism of FIG.
The vehicle can travel backward. In this case, N-
The R accumulator valve 53 gradually increases the engagement pressure of the reverse brake R / B and the band brake B / B, and can reduce these engagement shocks, that is, the NR select shock.

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

[0051]

Thus, the transmission control apparatus according to the present invention is described in claim 1.
, A low speed gear selecting friction element (second brake S / B in the illustrated example) and a high speed gear selecting friction element (band brake B / B in the illustrated example) are provided, and the operating pressure (P) of these two friction elements is provided. _{S / B} , P _{B / B} ) can be supplied / discharged by individual valves (in the illustrated example, solenoid valves 38, 50), and the friction element (S / B) for selecting the low-speed gear can be supplied 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 In this case, the second speed) is selected, and the high speed gear selecting element (B / B) is fastened by the operating pressure (P _{B / B} ) from the corresponding valve (50), and the low speed gear selecting element (B / B) is engaged. 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, this is configured to delay the switching of the state of the valve (38) until it reaches a set value (P _s ) that enables the sliding engagement of the high speed stage selecting friction element (B / B). Friction element (B /
After the operating pressure (P _{B / B} ) of _B ) reaches a set value (P _S ) that enables the high-speed gear selecting element (B / B) to slip-couple, the low-speed gear selecting friction element (S / B). B) operating pressure (P
_{S / B} ) can be compensated for. Therefore, as is apparent from the above description of the operation, the timing at which the high-speed stage selecting friction element (B / B) actually starts slidingly coupling is determined by the operating pressure (PS _/ ) of the low-speed stage selecting friction element (S / B). _B ) can be governed by the elimination, and when the low-speed gear element (S / B) is released by the elimination of the operating pressure (PS _{/ B} ), the high-speed gear element (B /
The sliding connection of B) can be caused. Therefore, it is possible to reliably eliminate the period in which the high-speed gear selecting element (B / B) and the low-speed gear selecting element (S / B) are released, and it is possible to reduce the number of engine revolutions, It is possible to prevent the accompanying large shift shock from occurring. In particular, the operating pressure (P _{B / B} ) of the high-speed gear selection friction element (B / B) to be engaged is monitored, and after this reaches a set value (P _S ), the low-speed gear selection friction element (S / _B ) is monitored. Since the operating pressure (P _{S / B} ) of _B ) was excluded, the set pressure (P
_It is not necessary for _S ) to be strict, and as described above, the above-mentioned effects can be reliably achieved if the frictional element for high-speed gear selection can be slidably coupled. It is possible to eliminate the annoyance of the set pressure described above, which occurs when the operating pressure (PS _{/ B} ) of ( _{S / B} ) is monitored.

[Brief description of the drawings]

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

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

FIG. 3 is a time chart of a 2 → 3 shift operation caused by a 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 a 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 selecting high-speed gear) S / B Second brake (friction element for selecting low-speed gear) 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 Lock-up control valve 18 Lubrication control valve 21 Pilot valve 23 Lock-up gain control valve 30 Manual valve 34 Duty solenoid valve 36 Duty solenoid 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 speed stage selection pressure detection means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48 B60K 41 / 00-41/28

Claims (1)

(57) [Claims] 1. A low-speed gear selecting element and a high-speed gear selecting friction element, wherein the operating pressure of these two friction elements can be supplied and discharged by individual valves, and the low-speed gear selecting friction element corresponds to the low-speed gear selecting element. The high-speed gear selection element is engaged with the high-speed gear selection element, and the low-speed gear is selected by compensating the released state of the high-speed gear selection friction element to prevent interlock. Automatic shifting that is engaged by operating pressure from the vehicle and releases 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 an upshift from the low-speed stage to the high-speed stage. A high-speed gear selection pressure detecting means for detecting an operating pressure of the high-speed gear selection friction element; and an operating pressure of the high-speed gear selection friction element detected by the high-speed gear selection element detects slippage of the high-speed gear selection friction element. Gear shift control for an automatic transmission, characterized in that there is provided low speed stage selection pressure elimination delay means for delaying the switching of the state of the valve corresponding to the low speed stage selection friction element until a set value enabling the low speed stage selection is reached. apparatus.