JPH0763256A - Speed change controller of vehicular automatic transmission - Google Patents

Abstract

PURPOSE:To prevent any interlock to be generated when a second frictional engaging element is engaged, so as to make a shift feeling good by changing the engagement starting time when the engaging operation of the second frictional engagement element is started according to the elapsed time after providing a speed changing means and detecting the speed change command by means of a speed change command detecting means. CONSTITUTION:In a vehicular automatic transmission, when the traveling state of a vehicle is the 3-4 upshift in high speed more than the specific speed, if engagement of a rear clutch 28 and a front clutch 24 is to be released, centrifugal oil pressure remains in respective pistons of the rear clutch 28 and the front clutch 24, thereby the engagement releasing of the rear clutch 28 and the front clutch 24, perpendicularly, the rear clutch 28, is delayed. Thereby, the engagement starting time of a kick down brake 30 is delayed from the 3-4 speed change command time by the specific time T, so as to prevent brake feeling by interlock from being generated in engaging of the kick down brake 30, and also so as to make a shift feeling good.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission for a vehicle, and more particularly to a shift control device for controlling execution of 3-4 upshift in a power-on state immediately after 4-3 downshift.

[0002]

2. Description of the Related Art An automatic transmission mounted on an automobile is constructed by providing a plurality of friction engagement means such as a hydraulic multi-plate clutch and a hydraulic brake. When the controller switches, the shift change of the automatic transmission is carried out.

For example, when the automatic transmission is upshifted from the third speed to the fourth speed, the controller first follows a predetermined program to establish a third speed clutch for establishing the third speed, that is, a rear clutch. Disengage and then disengage the front clutch and
The 4th-speed brake that establishes the speed, that is, the kickdown brake is engaged, and the grip change operation between each clutch and the brake is performed.

Therefore, in order to solve such a problem,
At high speed, the engagement start point of the kick down brake is delayed by a predetermined time T from the time of the shift command from the third speed to the fourth speed. That is, the interlock is prevented by providing the hydraulic pressure zero time T for waiting for the disengagement of the rear clutch and the front clutch in the engagement control of the kickdown brake.

On the other hand, when downshifting the automatic transmission from the fourth speed to the third speed, the controller releases the engagement of the kickdown brake for establishing the fourth speed according to a predetermined program, and The front clutch that establishes the third speed is engaged, and the brake and clutch are replaced. Then, the controller engages the rear clutch at the time when the grip change is completed.

[0006]

However, immediately after the automatic transmission downshifts from the fourth speed to the third speed, when the driving state of the engine is in the power-on state,
An upshift from fourth to fourth may be induced. In this case, when the rear clutch that establishes the third speed is in the process of being engaged, the amount of oil filled in the piston is small, so that the rear clutch takes less time than the normal 3-4 upshift. The hydraulic pressure is removed from and the engagement is released. Even in this case, at high speed,
The conventional hydraulic zero time T is set by the time the kickdown brake starts to be engaged, and the kickdown brake starts to be delayed. Therefore, when the rear clutch is disengaged, the torque is reduced. The only friction element that takes charge is the front clutch that is in the middle of disengagement, and this clutch begins to slip and the engine blows up. After that, when the kick down brake is engaged, there is a problem that the engagement becomes abrupt and a large shift shock occurs.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to prevent the engine from blowing up when the engine is in a driving state or when the engine is upshifted at a high speed, and furthermore, the shift is prevented. An object of the present invention is to provide a shift control device for a vehicle automatic transmission that can prevent the occurrence of shock.

[0008]

In order to achieve the above object, the present invention relates to a first gear shift stage achieved by engaging a first friction engagement element and a second friction engagement element. In a shift control device for an automatic transmission for a vehicle, which is achieved by combining the first shift stage and a second shift stage adjacent to the first shift stage, the shift control from the second shift stage to the first shift stage is completed. A shift end determination unit for determining, a shift command detection unit for detecting a shift command from the first shift stage to the second shift stage, and an elapsed time from the shift end determination to the shift command detection. A change for changing the engagement start time point from the time when the shift command detecting means detects the shift command to when the engagement operation of the second frictional engagement element is started according to the elapsed time. And means.

Preferably, the operating state of the vehicle is a state in which the engine mounted on the vehicle drives the automatic transmission, or a driven state in which the automatic transmission drives the engine side. A drive determination means for determining whether or not there is is provided. Then, when the drive determination means determines that the driving state of the vehicle is in the drive state, the engagement start time point is changed according to the elapsed time.

Preferably, the engagement start time point is changed stepwise or continuously according to the elapsed time. Preferably, a vehicle speed detecting means for detecting the traveling speed of the vehicle is provided. Then, when it is determined by the vehicle speed detection means that the vehicle is in a driving state below a predetermined vehicle speed,
The time when the shift command is detected is the time when the engagement starts.

[0011]

According to the shift control device for an automatic transmission for a vehicle of the present invention, the changing means performs the engaging operation of the second friction engagement element after the shift command detecting means detects the shift command. The engagement start time until the start is changed according to the elapsed time. Further, when the drive determination unit determines that the driving state of the vehicle is in the drive state, the engagement start time point is changed according to the elapsed time. Further, the engagement start time point is changed stepwise or continuously according to the elapsed time. Further, when the vehicle speed detection means determines that the vehicle is in a driving state at a predetermined vehicle speed or less, the time when the shift command is detected is the engagement start time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an example of an automatic transmission for a vehicle. In the figure, reference numeral 2 indicates an engine 2 that serves as a power source of the vehicle, and a crankshaft 4 of the engine 2 is directly connected to a pump 8 of a torque converter 6. The torque converter 6 includes a pump 8, a turbine 10, and a stator 1.
2. Connected to the case 16 via the one-way clutch 14. The stator 12 has a one-way clutch 14
Due to this, rotation in the same direction as the crankshaft 4 is permitted, but rotation in the opposite direction is blocked.

The torque transmitted to the turbine 10 is transmitted to the input shaft 20 and is then transmitted from the input shaft 20 to the input shaft 2.
0 is transmitted to the gear transmission 22 arranged at the rear part of the transmission.
Here, the gear transmission 22 has a structure that achieves four forward gears and one reverse gear. The gear transmission 22 is
Three sets of clutches 24, 26, 28, two sets of brakes 3
0, 32, a set of one-way clutches 34, and a set of Ravigneaux type planetary gear mechanisms 36.

The planetary gear mechanism 36 is composed of a ring gear 38, a long pinion gear 40, a short pinion gear 42, and a carrier 48 that rotatably supports both of these pinion gears 40 and 42 and is also rotatable. The ring gear 38 is connected to the output shaft 50, and the front sun gear 44 is connected to the kickdown drum 5.
2. It is connected to the input shaft 20 via the front clutch 24. On the other hand, the rear sun gear 46 is connected to the input shaft 20 via the rear clutch 26. The carrier 48 includes a low reverse brake 32 and a one-way clutch 34, which are functionally arranged in parallel.
And the input shaft 20 via an end clutch 28 arranged at the rear end of the transmission 22.

Here, the kick down drum 52 is
The kick down brake 30 can be fixedly connected to the case 16. The torque transmitted via the planetary gear mechanism 36 is transmitted to the output gear 60 fixed to the output shaft 50 so as to rotate integrally with the output shaft 50. Then, the output gear 60 passes through the idle gear 62 and the driven gear 64.
Is further transmitted to the differential gear unit 72 to which the drive shaft 70 of the drive wheel is connected via the transfer shaft 66 and the helical gear 68 fixed to the driven gear 64.

Each of the clutches and brakes, which are frictional engagement elements, is included in a frictional engagement device provided with an engagement piston device, a servo device, or the like. This frictional engagement device is included in the torque converter 6. By being connected to the pump 8, the discharge pressure from an oil pump (not shown) driven by the engine 2 is operated by the hydraulic pressure adjusted by a regulator valve (not shown).
This hydraulic pressure is selectively supplied to each clutch and brake according to various operating states by a hydraulic control device described later. One gear is achieved. It should be noted that, in Table 1, the mark ◯ indicates the engagement state of each clutch or brake, and the mark ● indicates the carrier 4 by the action of the one-way clutch 34 immediately before the low reverse brake 32 is engaged during gear shifting.
It is shown that the rotation of 8 is stopped.

[0017]

[Table 1] Next, in the gear transmission 22 shown in FIG. 1, an electronic hydraulic control device for achieving the gear stages shown in Table 1 will be described with reference to FIG. It should be noted that FIG. 2 shows only the hydraulic control element portions that operate the front clutch 24 and the kickdown brake 30, respectively. The overall structure and operation of this electronic hydraulic control device is disclosed in Japanese Patent Laid-Open No. 58-462
Since it is already known from No. 58, etc., description of other hydraulic control elements for brakes and clutches will be omitted.

The kickdown servo 31 as a reciprocating hydraulic actuator for controlling the operation of the kickdown brake 30 is slidably fitted in the housing defining the stepped cylinder hole 80 and the stepped cylinder hole 80. And a piston rod extending from the piston 59 to the outside of the housing, that is, an actuator rod 79. The tip of the actuator rod 79 is a kickdown brake 30, that is, an actuator rod 79. The brake shoe wound around the peripheral surface of the kick down drum 52 can be brought into contact with and engaged with the brake shoe. And, the piston 59 has the stepped cylinder hole 8
The first and second pressure chambers 81 and 82 are defined by being divided into 0, and as is clear from FIG. 2, the first pressure chamber 81 is
It is defined between the step surface of the piston 59 and the step surface of the stepped cylinder hole 80.

A first shift valve 33 is connected to the first pressure chamber 81 of the kickdown servo 31 via an oil passage 35, and the 1-2 shift valve 33 further includes:
A hydraulic control valve 37 is connected via an oil passage 41. The oil pressure control valve 37 is connected to the oil passage 61 at the left end thereof as seen in FIG. 2 and also to the oil passage 63. Into the oil passage 61, a pilot pressure whose pressure is regulated by the regulator valve and whose hydraulic pressure is further reduced by a regulation racing valve (not shown) is introduced, and the oil passage 61 is opened and closed in the middle thereof. An electromagnetic valve 67 for controlling the pressure of pilot pressure supplied through the hydraulic control valve 37 is inserted. The solenoid valve 67 is electrically connected to a controller (ECU) 65, and the controller 65 controls the switching operation of the solenoid valve 67 by duty control.

The line pressure regulated by the regulator valve described above is supplied to the oil passage 63. The pilot pressure in the oil passage 61 is controlled by the solenoid valve 67 that opens and closes according to the duty ratio, so that the hydraulic pressure according to the duty ratio acts on the left end surface of the spool 69 of the shift control valve 37. In this embodiment, a normally-closed type solenoid valve that reduces the pilot pressure in the oil passage 61 as the duty ratio increases is used. For this reason, the hydraulic control valve 37 regulates the line pressure from the oil passage 63 and changes the hydraulic pressure according to the duty ratio, that is, the hydraulic pressure that gradually decreases as the duty ratio increases to the oil passage 41.
Will occur. The solenoid valve 67 may be a normally open type.

An oil passage 83 is branched from the middle of the oil passage 35, and the orifice 9 is provided in the middle of the oil passage 83.
2 is arranged and connected to the 3-4 shift valve 84.
The 3-4 shift valve 84 is further connected to bifurcated oil passages 85 and 86. One of these two oil passages 85 is the second oil passage 85 of the kickdown servo 31.
It is connected to the pressure chamber 82, and the other oil passage 86
Is connected to the front clutch 24 described above.
Note that, in FIG. 2, the front clutch 24 is only schematically illustrated.

Here, the 1-2 shift valves 33 and 3-4
The shift valve 84 is a spool-type on-off valve that is opened and closed by the pressure supplied to the operation control ports 87 and 88, and the pressure to the operation control ports 87 and 88 is specifically the regulator valve described above. It is also guided from a shift control valve (not shown).

The controller 65 not only controls the opening and closing of the solenoid valve 67, but also incorporates a gear shift command output device which outputs a gear shift command based on the operating state of the vehicle. Also,
The controller 65 has a built-in storage device such as ROM and RAM (not shown), a central processing unit (CPU), a counter used as a timer, and the like. This controller 4
On the input side of 0, various sensors, for example, No sensor 1
00, θt sensor 102, turbine speed sensor Nt1
01 and the like are electrically connected.

The counter is capable of outputting time data while the controller 65 is operating. The No sensor 100 is a transfer drive gear rotation speed sensor that detects a rotation speed No of a transfer drive gear (not shown). The controller 65 uses this rotation speed No.
The vehicle speed V can be calculated based on

The θt sensor 102 is a throttle valve opening sensor for detecting a valve opening θt of a throttle valve arranged in the intake passage of the engine 2 (not shown). Each of these sensors 100 and 102 supplies a detection signal to the controller 65 in a predetermined control cycle. Note that FIG.
Reference numeral 93 indicates a kick down switch. The kick down switch 93 is configured such that the piston 59 is moved leftward in FIG. 2 together with the actuator rod 79, and the actuator rod 79 causes
When the piston 59 is moved to the reference position to the extent that the brake shoe play in the kick down brake 30 is eliminated, a detection signal is supplied to the controller 65.

Further, the controller 65 carries out a shift change of the automatic transmission according to a program stored in the storage device. That is, the controller 65 continues to monitor the signals from the No sensors, the θt sensor, and the like, and determines the shift speed suitable for the traveling state of the vehicle based on these signals. The shift change between the third speed and the fourth speed will now be described.

The engagement elements (first friction engagement elements) that achieve the third speed (first speed) are the front clutch 24, the rear clutch 26, and the end clutch 28. Each engagement element (second friction engagement element) that achieves the shift speed (second shift speed) to the fourth speed is the kickdown brake 30.
And the end clutch 28. In the shift change between the third speed and the fourth speed, the end clutch 28 is always engaged, and the 1-2 shift valve 33 moves to the right as shown in FIG. It is kept displaced.

First, description will be made regarding the case where the gear position is the fourth speed (second gear position). At the fourth speed, the spool 55 of the 1-2 shift valve 33 is in the state shown in FIG. 2, and therefore the oil passage 35 is communicated with the oil passage 41. At this time, the solenoid valve 67 has a duty ratio of 0%, that is, it is non-excited, and the spool 69 of the hydraulic control valve 37 moves right in FIG. Road 4
Connect with 1. This allows the kick down servo 31
The first pressure chamber 81 is connected to the high pressure side.

At this time, the shift control pressure is not supplied to the 3-4 shift valve 84 through the operation control port 88, and the spool 89 is displaced to the left end as shown in FIG. is there. Therefore, in this case, the oil passage 86 leading to the front clutch 24 has three
The -4 shift valve 84 is in a state of being connected to the drain side through the oil drain port 90, whereby the front clutch 2
4 has been disengaged.

In this case, since the oil passages 85 and 86 are always communicated with each other, the second pressure chamber 80 in the kickdown servo 31 is also connected to the discharge side. Therefore, when the pressure liquid is supplied to the first pressure chamber 81 of the kickdown servo 31 through the oil passages 41 and 35, the piston 59, that is, the actuator rod 79, moves leftward to move the kickdown brake 30. Are engaged.

Next, a description will be given of the case where the gear shift stage is changed from the fourth speed to the third speed by the 4-3 shift signal. In this case, the 1-2 shift valve 33 is
Although the switching position shown in the figure is still maintained, the 3-4 shift valve 84 is in the switching position where the spool is moved to the right because the shift control pressure is supplied to the port 88. The oil passage 83 and the oil passages 85 and 86 are communicated with each other via the 3-4 shift valve 84, and the oil discharge port 90 thereof is closed. In this case, 1
The pressure liquid supplied to the oil passage 83 through the -2 shift valve 33 is supplied to the front clutch 24 through the 3-4 shift valve 84 and also through the oil passage 86. 24 is in the engaged state.

On the other hand, in the kick down servo 31, since the oil passages 86 and 85 are always in communication with each other, the pressure liquid supplied to the front clutch 24 is also supplied to the second pressure chamber 82 thereof. At the same time, the same pressure liquid is supplied to the first pressure chamber 81 through the oil passage 35. In this case, since the piston 59 of the kick-down servo 31 is a stepped piston as described above, the piston 59 is displaced to the right along with the actuator rod 79 due to the difference in the pressure receiving areas at both ends thereof. The kick down brake 30 is disengaged.

However, the hydraulic pressure is still supplied to the first pressure chamber 81 via the 1-2 shift valve 33. Then, after this, the rear clutch 26 is engaged and the third clutch is engaged.
A fast gear is established. A case will be described in which after the completion of the 4-3 downshift, the shift signal for the fourth speed is output again, and the shift speed is changed from the third speed to the fourth speed.

In this case, first, the rear clutch 26 is disengaged, and then the front clutch 24 is replaced with the kickdown brake 30. That is, when the 3-4 shift command is output, the 3-4 shift valve 84 becomes the switching position shown in FIG.
4 and the second pressure chamber 82 of the kick down brake 30 through the oil discharge port 90 and the orifice 91.

At this time, as described above, the first pressure chamber 8
Since the hydraulic pressure is supplied to 1, the piston 59 and the actuator rod 79 tend to be displaced in the direction in which the kick down brake 30 is engaged at the same time when the hydraulic pressure is released from the second pressure chamber 82. The solenoid valve 67
To drive the hydraulic pressure in the first pressure chamber 81 to zero once,
The displacement is prohibited.

Thus, the delay in releasing the front clutch 24 and the rear clutch 28 due to the action of the centrifugal hydraulic pressure described as the prior art is prevented from causing the interlock due to the engagement of the kick down brake 30. Next, the present invention will be specifically described with reference to the flows of FIGS. Note that FIG. 3 and FIG.
The procedure of the -4 upshift routine is shown, and the controller 65 repeatedly executes this procedure.

First, in step S103 of FIG. 3, the front clutch 24 is gripped from the kick down brake 30 based on the 4-3 shift command from the controller 65, and then the rear clutch 28 is engaged. Control the brake. Next, step S1
At 04, it is determined whether or not there is a 4-3 shift end determination signal (shift end determination means). In step S104, if the determination result is positive (Yes), that is, if the 4-3 shift end determination signal is detected, step S10.
If the determination is No (No), that is, if the 4-3 shift end determination signal is not detected, the process proceeds to step S103.
Return to.

Specifically, the controller 65 is 4-3.
If a shift is performed, the kickdown brake 30
The 4-3 shift end determination signal is detected at the time point when the gripping of the front clutch 24 with the front clutch 24 is completed, that is, at the time point a in FIG. At the time when the 4-3 shift end determination signal is detected, the rear clutch 2
6 is not yet fully engaged.

For example, the determination result of step S104 becomes positive (YES), and the controller 65 causes step S1 to proceed.
Proceed to 06. In step S106, the controller 65
Starts the k timer. That is, the k timer starts reading the time from the above-mentioned counter to the timer number k. In FIG. 5, the counting of the k timer is started from the time point a on the time axis.

Next, in step S108, it is determined whether or not there is a 3-4 shift command (shift command detection means). In step S108, if the determination is positive (Yes), that is, if the 3-4 shift command is detected, the process proceeds to step S110. Conversely, if not (No), that is, if the 3-4 shift command is not detected, The determination in step S108 is repeatedly executed until the determination becomes positive (Yes). During this time, the timer variable k is integrated with time.

Specifically, the controller 65 is 3-4
The shift command is discriminated based on the signals from the respective No sensors, θt sensor, etc., and, for example, at the time point b in FIG.
The -4 shift command is detected, the determination in step S108 becomes positive (Yes), and the process proceeds to step S110. In step S110, the k timer is stopped. Therefore, the timer variable k of the k timer is set to step S10.
The time from when it is determined to be positive (Yes) in 4 to when it is determined to be positive (Yes) in step S108, that is, 4-
The time from the 3rd shift end determination to the 3-4 shift command detection is read. Then, the controller 65 proceeds to step S112.

In step S112, the timer variable k is substituted into the variable K, and the timer variable k is reset to 0.
Then, the controller 65 proceeds to step S114.
In step S114, it is determined whether the operating state of the vehicle engine is the power-on state or the power-off state based on the determination condition (θt> θo) (drive determination means). That is, the throttle opening θt is equal to the predetermined opening θo.
If the determination result is positive (Yes), it is determined that the operating state of the vehicle engine is the power-on state (driving state), and step S
Proceed to 116. Conversely, when the determination result is negative (No), it is determined that the operating state of the vehicle engine is the power-off state (driven state), and the routine proceeds to step S128 via step S130.

For example, if the determination in step S114 is positive (Yes) and it is determined that the power is on, the controller 65 proceeds to step S116. In step S116, the determination condition (No> 3850 rpm)
Based on the rotational speed No of the transfer drive gear read from the No sensor, it is determined whether the vehicle is running at a high speed. That is, when the determination result is positive (Yes) by determining whether the rotation speed No is higher than 3850 (rpm), the controller 6
No. 5 judges that the traveling state of the vehicle is the high speed state, and proceeds to step S118, and conversely, the judgment result is negative (No).
If it is, it is determined that the running state of the vehicle is equal to or lower than the medium speed state, and the process proceeds to step S128 via step S130.

The determination conditions in step S116 are
Since the value varies depending on the automatic transmission, the numerical value of the determination condition may be changed to another numerical value as long as it can be determined that the traveling state of the vehicle is high speed. When the determination result of step S116 is positive (Yes) and it is determined that the traveling state of the vehicle is the high speed state, the controller 65 proceeds to step S118.

In step S118, the discrimination condition (K ≧
Based on 1), the controller 65 determines the length of the count time from the 4-3 shift end determination to the 3-4 shift command detection. That is, the value of the variable K, that is,
It is determined whether the K time is 1 (second) or more. Then, if the determination result is positive (Yes), the controller 65 sets the value 71 to the variable α in step S120 and proceeds to step S124. On the contrary, if not (No), in step S122. The value α is set to the variable α and the process proceeds to step S124.

For example, from the time of determination of the 4-3 shift end, 3
-4 If it takes more than 1 (second) to detect the shift command,
The controller 65 proceeds to step S120 and sets α to 7
Set to 1, and the process proceeds to step S124. Step S1
In 24, the controller 65 uses the arithmetic expression T = (No / 3
The number of revolutions N based on (8.14−α) × 5 × 10 −3 (seconds)
The T time is calculated using o and α as variables. Then, the controller 65 proceeds to step S126, outputs T time, and proceeds to step S128.

The time T is a hydraulic pressure zero time from when the 3-4 shift command is detected to when the engagement control of the kick down brake 30 is started, and according to FIG. 5, it is a section from time b to time c. . The controller 65 sets the duty ratio of the solenoid valve 67 that controls the operating oil pressure of the kick down brake 30 to 100% during this T time, and removes the oil pressure from the first pressure chamber 81 of the kick down brake 30 for the T time. . Then, after the lapse of this T time, the controller 65 sets the duty ratio of the solenoid valve 67 to 0%, supplies the hydraulic pressure to the first pressure chamber 81 of the kickdown brake 30 again, and starts the engagement. This completes the 3-4 upshift routine.

In the automatic transmission for a vehicle, in the 3-4 upshift when the vehicle is running at a high speed equal to or higher than a predetermined speed, even if the rear clutch 28 and the front clutch 24 are disengaged, the rear clutch 28 and the front clutch 24 are disengaged. Since centrifugal oil pressure remains in each piston of the front clutch 24, the disengagement of the rear clutch 28 and the front clutch 24, particularly the rear clutch 28, is delayed. For this reason,
At a high speed, the engagement start point of the kick down brake 30 is delayed by a predetermined time T from the time of the 3-4 shift command to prevent a brake feeling due to interlock when the kick down brake 30 is engaged, and to shift the shift. Make the feeling good.

On the other hand, from the time of determining the 4-3 shift end, 3-4
The elapsed time may be short until the shift command is detected. For example, when the elapsed time, that is, the K time is shorter than 1 (second), the controller 65 determines NO (No) in step S118, proceeds to step S120, and sets α
To 95. Then, the controller 65 proceeds from step S124 to step S128.

In this case, as the value of T calculated in step S124, α is 7 when the rotation speed No is the same value.
It is set shorter than the case of 1. Immediately after the automatic transmission downshifts from the fourth speed to the third speed, an upshift from the third speed to the fourth speed may be induced when the engine is in the power-on state. In this case,
When the rear clutch 26 that establishes the third speed is in the middle of engagement, the amount of oil filled in the piston is small, so that the hydraulic pressure from the rear clutch 26 is reduced in a shorter time than in the normal 3-4 upshift. Are discharged and the engagement is released. Therefore, in this case, the hydraulic pressure zero time T until the start of engagement of the kick down brake 30 is set to be short so that the start of engagement of the kick down brake 30 is not delayed from the disengagement of the rear clutch 26. It suppresses the occurrence of shift shock when the kick down brake is engaged. Therefore, in the power-on state, the front clutch 24, which is in the middle of disengagement, does not start slipping up and the kickdown brake 30 is not engaged abruptly, which causes a large shift shock. It can be prevented.

On the other hand, in step S104, when the determination result is negative (No), that is, when the 4-3 shift end determination is not made, the 4-3 downshift control is continued. Further, when the determination result is NO in step S114 and step S116, the T time is set to 0 (second) in step 130. Therefore, the controller 65 does not set the hydraulic pressure zero time after detecting the 3-4 shift command, and immediately starts the shift change.

In the above description, when the elapsed time, that is, the value of K time is 1 (seconds) or more, α is set to 71, otherwise, that is, the value of K time is smaller than 1 (seconds). At this time, α was set to 95, but the value of α was changed stepwise according to K time (for example, α = 71, 73, 7).
5 ,. ． ． ． It goes without saying that a more stable shift change can be performed if it is possible to change continuously.

In this embodiment, when the output value of the turbine rotation speed sensor Nt101 becomes substantially equal to the turbine rotation speed (Nt3) at the third speed, it is determined that the 4-3 shift has ended (Fig. When the 3-4 upshift is detected before the turbine speed reaches Nt3, that is, when the 3-4 upshift is detected during the 4-3 downshift, the 3-4 upshift signal ends the 4-3 downshift. It may be regarded as a signal. In this case, the 4-3 shift end signal overlaps with the 3-4 shift command, and in step S106 of FIG.
At the moment when the timer is started, the determination is positive (Yes) in step S108, and the k timer is stopped in step S110.

[0054]

Since the present invention is constructed as described above, it has the following effects. The change means is provided, and the engagement start time point at which the engagement operation of the second friction engagement element is started after the shift command detection means detects the shift command is changed according to the elapsed time. Therefore, it is possible to prevent the occurrence of interlock at the time of engaging the second frictional engagement element, and it is possible to improve the shift feeling.

Further, when the drive determination means determines that the driving state of the vehicle is in the drive state, the second frictional engagement can be performed by changing the engagement start time point according to the elapsed time. When the elements are engaged, the engaging elements do not slide out, the engine can be prevented from blowing up, and the shift shock at the time of engagement can be prevented. Furthermore, if the engagement start point is changed stepwise or continuously according to the elapsed time, a smoother shift change can be performed.

Further, when the vehicle speed detecting means determines that the vehicle is in a driving state below a predetermined vehicle speed, if the time when the shift command is detected is the engagement start time point, a quick shift change can be performed.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing a schematic internal configuration of an automatic transmission.

FIG. 2 is a diagram showing a hydraulic circuit around a kickdown servo and a front clutch.

FIG. 3 is a diagram showing a flowchart of a 3-4 upshift routine immediately after a 4-3 shift.

FIG. 4 is a diagram showing a flowchart of a 3-4 upshift routine immediately after a 4-3 shift.

FIG. 5 is a graph showing a relationship between a change in duty ratio of a solenoid valve and time.

[Explanation of symbols]

 2 engine 6 torque converter 22 gear transmission 24 front clutch 26 rear clutch 28 end clutch 30 kick down brake 31 kick down servo 37 shift control valve 65 controller 67 solenoid valve 84 3-4 shift valve 100 No sensor 102 θt sensor

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shoji Nakamura 5-3-8 Shiba, Minato-ku, Tokyo Within Mitsubishi Motors Corporation (72) Inventor Masakazu Kinoshita 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Automobile Industry Co., Ltd. (72) Inventor Koichi Yamagoku 5-3-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Industry Co., Ltd.

Claims (4)

[Claims] 1. A first gear shift stage which is achieved by engaging a first friction engagement element and a second gear shift stage which is achieved by engaging a second friction engagement element and is adjacent to the first gear shift stage. A shift control device for an automatic transmission for a vehicle, comprising two shift stages, a shift end determination means for determining a shift end from the second shift stage to the first shift stage, and the first shift stage to the first shift stage. A gear shift command detecting means for detecting a gear shift command to the second gear stage, a time measuring means for measuring an elapsed time from the gear shift end determination to the gear shift command detection, and the gear shift command detecting means detects the gear shift command And a changing means for changing the engagement start time from when the engagement operation of the second friction engagement element is started to the second friction engagement element according to the elapsed time. Shift control device. 2. The operating state of the vehicle is a state in which the engine mounted on the vehicle drives the automatic transmission, or a driven state in which the automatic transmission drives the engine side. And a driving determination unit that determines whether the driving state of the vehicle is in a driving state, and changes the engagement start time point according to the elapsed time. A shift control device for an automatic transmission for a vehicle according to claim 1. 3. The shift of the vehicular automatic transmission according to claim 1, wherein the engagement start time point is changed stepwise or continuously in accordance with the elapsed time. Control device. 4. A vehicle speed detecting means for detecting a traveling speed of the vehicle is provided, and when the vehicle speed detecting means determines that the vehicle is in a driving state at a predetermined vehicle speed or less, the operation of detecting the shift command is performed by the operator. The shift control device for an automatic transmission for a vehicle according to any one of claims 1 to 3, characterized in that the shift start time is the start time.