JPH0765671B2 - Automatic transmission control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for an automatic transmission that reduces shift shock during downshifting and enhances shift responsiveness.

(Prior Art) Generally, as an automatic transmission, a combination of a torque converter and a multistage gear type speed change mechanism having a gear mechanism such as a planetary gear mechanism is widely used. A hydraulic mechanism is usually employed for shift control in such an automatic transmission, and a hydraulic circuit is switched by an electromagnetic switching valve,
As a result, a friction element such as a brake or a clutch as a fluid type actuator associated with the multi-stage gear type speed change mechanism is appropriately operated to switch the transmission system of engine power to obtain a required speed stage. Then, in order to switch the hydraulic circuit by the electromagnetic switching valve, it is detected by the electronic control unit that the running state of the vehicle exceeds the predetermined shift line, and the electromagnetic signal is sent by the shift up signal or the shift down signal from this unit. It is customary to selectively actuate the directional control valve, thereby switching the hydraulic circuit and shifting.

In an automatic transmission having this torque converter,
Since the slippage of the torque converter cannot be avoided, a lockup mechanism for directly connecting the engine output shaft and the output shaft of the torque converter is often provided for improving fuel efficiency. This lock-up mechanism is designed to perform lock-up (direct connection) or lock-up release by controlling the supply of hydraulic pressure to the associated hydraulic actuator by means of the lock-up electromagnetic means. This lockup or lockup release is performed by the electronic control device by outputting a lockup signal or a lockup release signal to the lockup electromagnetic means based on a predetermined lockup characteristic. It is usually done.

As described above, in the automatic transmission having the lock-up mechanism, in order to avoid a large shock caused by shifting in the lock-up state, the lock-up mechanism is in the lock-up state, as shown in JP-A-56-39354. Even if there is a shift, control is generally performed so that the lockup is temporarily released during the shift and the torque fluctuation (engine speed difference) accompanying the shift is absorbed by the torque converter. In such a case, as seen in the above publication, in order to more sufficiently reduce the shift shock when the downshift is performed, after first outputting the lockup release signal,
The shift-down signal is output later than the lock-up release signal output. To elaborate on this point,
Downshifts are often performed during deceleration, but in this case, in order to further reduce shift shock, it is preferable that the engine speed difference before and after downshifts is small. Therefore, by performing lockup release. It is preferable to reduce the engine load, increase the engine speed, and perform downshifting after the engine speed increases. Since it takes a certain amount of time for the engine speed to rise due to the lockup release, the shift down signal output is performed later than the lockup release signal output.

However, when the shift-down signal output is delayed from the lock-up release signal output as described above, the shift responsiveness inevitably deteriorates (the time until completion of the shift-down becomes long), and the driver's sense may be felt depending on the driving mode. There may be cases where they do not match. In other words, while downshifting is usually performed during deceleration, there are also cases in which a large acceleration is desired, such as kickdown.
In such a case, the shift-down response delay described above does not match the driver's feeling.

(Object of the Invention) The present invention has been made in consideration of the above circumstances.
Provided is a control device for an automatic transmission, which is more excellent in shift feeling, by surely alleviating unpleasant shift shock that is not predicted or expected by the driver at the time of downshifting, while enhancing the shift responsiveness as much as possible. The purpose is to

(Structure of the Invention) According to the present invention, even when the same downshift is performed, when the downshift is performed in a state where the driver wants to accelerate, the driver can predict the shift shock in advance or rather feel a power. Focusing on the fact that it is possible to know whether or not it is in the operating region where an unpleasant unpleasant gear shift shock occurs by looking at the state of change in engine speed during downshifting, taking into consideration that there is even a desirable tendency to feel. It was done by. That is, when the engine speed, which tends to cause an uncomfortable shift shock, is decreasing, the shift-down signal output is delayed from the lock-up release signal output in order to positively alleviate the shift shock. When the engine speed, which is unlikely to cause shift shock, tends to rise, the lockup release signal is output in order to improve the shift responsiveness, taking into consideration the fact that even if a shift shock occurs, it does not pose a problem as described above. And the shift-down signal output are synchronized with each other.

Specifically, as shown in FIG. 1, a torque converter connected to an engine output shaft, a gear type speed change mechanism connected to the output shaft of the torque converter, an engine output shaft and an output shaft of the torque converter. A lock-up mechanism for connecting and disconnecting the lock-up mechanism, a solenoid for speed change that controls the supply of pressure fluid to the fluid-type actuator that performs a shift operation of the gear-type transmission mechanism, and a pressure for a fluid-type actuator that performs an intermittent operation of the lock-up mechanism A lock-up electromagnetic means for controlling the supply of the fluid; a shift control means for outputting a shift-up signal or a shift-down signal to the shift electromagnetic means based on a predetermined shift characteristic; Based on the lockup characteristic, the lockup signal is transmitted to the lockup electromagnetic means. No. or lockup control means for outputting a lockup release signal, rotation speed detection means for detecting the rotation speed of the engine output shaft, and when a downshift signal is output to the shifting electromagnetic means in a lockup state, On the basis of the signal from the rotation speed detection means, when the rotation speed of the engine output shaft tends to increase, the shift down signal and the lockup release signal are output in synchronization, and the rotation speed of the engine output shaft is When there is a downward tendency, output timing adjusting means for outputting the lockup release signal and outputting the downshift signal after the lockup release signal is output is provided.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 2 showing a cross section of a mechanical portion of an electronically controlled automatic transmission and a hydraulic control circuit, an automatic transmission AT includes a torque converter 10, a multi-stage gear transmission mechanism 20, a torque converter 10, a multi-stage gear transmission mechanism 20. And a planetary gear speed change mechanism 50 for overdrive arranged between the two.

The torque converter 10 includes a pump 11 connected to the engine output shaft 1 and a turbine 1 arranged to face the pump 11.
2 and a stator 13 arranged between the pump 11 and the turbine 12, and the turbine 12 has a converter output shaft 14
Are combined. A lockup clutch 15 is arranged between the converter output shaft 14 and the pump 11. The lockup clutch 15 is constantly urged by the hydraulic oil pressure circulating in the torque converter 10 in a direction in which the engine output shaft 1 and the torque converter output shaft 14 are locked up (directly connected), and at the same time, externally. It is held in an open state by the opening hydraulic pressure supplied from.

The multi-stage gear speed change mechanism 20 has a front stage planetary gear mechanism 21 and a rear stage planetary gear mechanism 22. There is. The input shaft 26 of the multi-stage gear transmission 20 is connected to the connecting shaft 25 via the front clutch 27 and the rear clutch 28.
Are connected to the internal gear 29 of the front planetary gear mechanism 21 via. A front brake is provided between the connecting shaft 25 or the sun gear 23, 24 and the transmission case.
30 are provided. Planetary carrier 31 of front stage planetary gear mechanism 21 and internal gear 33 of rear stage planetary gear mechanism 22
Are connected to the output shaft 34, and a rear brake is provided between the planetary carrier 35 of the rear planetary gear mechanism 22 and the transmission case.
A 36 and a one-way clutch 37 are provided.

In the overdrive planetary gear speed change mechanism 50, the planetary carrier 52 that rotatably supports the planetary gear 51 is connected to the output shaft 14 of the torque converter 10, and the sun gear 53 is connected to the internal gear 55 via the direct coupling clutch 54. It has become so. An overdrive brake 56 is provided between the sun gear 53 and the transmission case,
The internal gear 55 is the input shaft of the multi-stage gear transmission 20.
It is connected to 26.

The multi-stage gear speed change mechanism 20 has a conventionally known type having three forward speeds and one reverse speed, and a desired speed can be obtained by appropriately operating the clutches 27 and 28 and the brakes 30 and 36. Is. In the overdrive planetary gear speed change mechanism 50, the direct coupling clutch 54 is engaged to brake 56.
When the clutch is released, the shafts 14 and 26 are directly connected, while the brake 56 is engaged, and when the clutch 54 is released, the shafts 14 and 26 are overdriven.

The automatic transmission AT described above includes the hydraulic control circuit CK as shown in FIG. The hydraulic control circuit CK has an oil pump 100 driven by the engine output shaft 1. The hydraulic oil discharged from the oil pump 100 to the pressure line 101 is adjusted in pressure by a pressure regulating valve 102 and selected by a select valve 103. Be led to. Select valve 103 has 1, 2, D,
It has N, R, and P shift positions, and the select valve 103
Is in the 1, 2 and D positions, the pressure line 101 communicates with the ports a, b, c of the select valve 103. Port a
Is connected to the actuator 104 for actuating the rear clutch 28, and the rear clutch 28 is held in the engaged state when the valve 103 is in the position described above. Port a is also 1-2
It is also connected near the left end of the shift valve 110, and the spool thereof is pressed to the right in the figure. The port a is further connected to the right end of the 1-2 shift valve 110 via the first line L1, to the right end of the 2-3 shift valve 120 via the second line L2, and via the third line L3. It is connected to the right end of each of the 3-4 shift valves 130.

From the first, second and third lines L1, L2 and L3, the first, second and third drain lines DL1, D are respectively provided.
L2 and DL3 are branched, and these drain lines DL
First, second, and third solenoid valves SL1, SL2, SL for opening and closing the drain lines DL1, DL2, DL3 are connected to 1, DL2, DL3.
3 is connected. Above solenoid valves SL1, SL2, SL3
Is excited when the line 101 and the port a are in communication, the drain lines DL1, DL2, DL3 are closed, and as a result, the pressure in the first, second, and third lines is increased. There is.

Port b is also connected to the second lock valve 105 via line 140, and this pressure acts to push the spool of the second lock valve 105 downward in the figure. When the spool of the second lock valve 105 is in the lower position, the line 140 and the line 141 communicate with each other, and hydraulic pressure is introduced into the engagement side pressure chamber of the actuator 108 of the front brake 30 to hold the front brake 30 in the operating direction. . Port c is connected to a second lock valve 105 whose pressure acts to push the spool of valve 105 upwards. Further, the port c is connected to the 2-3 shift valve 120 via the pressure line 106. In this line 106, when the solenoid valve SL2 of the second drain line DL2 is excited, the pressure in the second line L2 is increased, and this pressure causes the spool of the 2-3 shift valve 120 to move to the left. , Communicate with line 107. The line 107 is connected to the release side pressure chamber of the actuator 108 of the front brake 30, and when hydraulic pressure is introduced into the pressure chamber,
The actuator 108 operates the brake 30 in the releasing direction against the pressure of the engagement side pressure chamber. The pressure in the line 107 is also guided to the actuator 109 of the front clutch 27 and engages the clutch 27.

The select valve 103 has in one position a port d leading to the pressure line 101, this port d reaching the 1-2 shift valve 110 via line 112 and further connecting via line 113 to the actuator 114 of the rear brake 36. To be done. 1-2
When the solenoid valves SL1 and SL2 are excited by a predetermined signal, the shift valve 110 and the 2-3 shift valve 120 move the spool to switch the line, thereby operating a predetermined brake or clutch, and each of them is set to 1 -2, 2-
The gear shifting operation of No. 3 is performed. Further, the hydraulic control circuit CK has a cutback valve 115 for stabilizing the hydraulic pressure from the pressure regulating valve 102,
A vacuum throttle valve 116 that changes the line pressure from the pressure regulating valve 102 according to the magnitude of the intake negative pressure, and a throttle backup valve 117 that assists the throttle valve 116 are provided.

Further, the hydraulic control circuit CK of this example is provided with a 3-4 shift valve 130 and an actuator 132 for controlling the clutch 54 and the brake 56 of the planetary gear speed change mechanism 50 for overdrive. The engagement side pressure chamber of the actuator 132 is connected to the pressure line 101, and the line 101
The brake 56 is pushed in the engagement direction by the pressure. This 3-4 shift valve is also the above 1-2, 2-3 shift valve 11
When the solenoid valve SL3 is excited as in the case of 0 and 120, the 3-
The spool 131 of the 4-shift valve 130 moves downward, the pressure line 101 and the line 122 are shut off, and the line 122 is drained. As a result, the hydraulic pressure acting on the release side pressure chamber of the actuator 132 of the brake 56 disappears, the brake 56 is actuated in the engaging direction, and the actuator 134 of the clutch 54 acts so as to release the clutch 54.

Furthermore, the hydraulic control circuit CK of this example includes a lockup control valve.
133 is provided, and this lockup control valve 133 is connected to the port a of the select valve 103 via the line L4. From this line L4, drain lines DL1, DL2, DL
Drain line DL4 equipped with solenoid valve SL4 similar to 3
Is branched. When the solenoid valve SL4 is excited and the drain line DL4 is closed to increase the pressure in the line L4, the lockup control valve 133 has its spool moved to the line 12
3 and the line 124 are cut off, the line 124 is drained, and the lockup clutch 15 is moved in the operating direction.

The following Tables 1 to 3 show the operational relationship between each shift speed and lockup and each solenoid, and the operational relationship between each shift speed, clutch and brake in the above configuration.

FIG. 3 shows an example of a control device for the automatic transmission AT according to the present invention, which is configured to control the hydraulic control circuit CK associated with the above-mentioned automatic transmission AT to perform shift control and lockup control. , With the engine EN incorporating the automatic transmission AT.

In FIG. 3, the control unit 200 is an automatic transmission A.
A lockup control circuit 201 for performing lockup control for T and a shift control circuit 202 for performing shift control are included. Further, the rotation speed of the output shaft 14 of the torque converter 10 of the automatic transmission AT, that is, the turbine rotation speed TSP is detected by a turbine rotation speed sensor TS attached thereto, and a throttle valve 204 of a throttle valve 204 provided in an intake passage 203 of the engine EN is detected. The throttle opening TH is detected by the engine load sensor LS.

The turbine speed signal St obtained from the turbine speed sensor TS is output to the change state detection circuit 205, the lockup control circuit 201 and the shift control circuit 202, and the throttle opening signal Sn obtained from the engine load sensor LS. But,
It is supplied to the lockup control circuit 201 and the shift control circuit 202. Here, the turbine speed TSP is treated as information corresponding to the vehicle speed, and the throttle opening TH is treated as information corresponding to the engine load, but it is necessary to set a delay condition from the lockup release signal output to the shift down signal output. The engine speed (the rising tendency of the engine speed) is determined by at least the engine speed of the lockup clutch 15. That is, the rotational speed itself of the engine output shaft 1 when the lockup is released is checked.

In the embodiment, the change state detection circuit 205 detects, on the basis of the turbine rotation speed signal St, whether the turbine rotation speed when the downshift signal is output, that is, the engine rotation speed tends to increase or decreases. In the example,
It is assumed that the change rate of the turbine speed TSP dTSP / dT ≧ 0 indicates an upward trend, and that the dTSP / dT <0 indicates a downward trend, the signal Sp indicating the upward trend or the downward trend. Is output to the shift control circuit 202.

The shift control circuit 202 of the control unit 200 is obtained from the turbine rotation speed signal St from the turbine rotation speed sensor TS, the throttle opening signal Sn from the engine load sensor LS, and a traveling mode sensor (not shown) that detects a traveling mode. Information, for example, turbine speed shown in FIG.
Based on the engine load characteristic, the shift map is compared with the shift-up shift line and the shift-down shift line determined in advance to calculate whether or not to shift. And
Depending on the result of this calculation, the shift-up signal Cp or the shift-down signal Cp 'is output to the first, second, and third solenoid valves SL1, SL2, SL3 of the hydraulic control circuit CK, and the first and second solenoid valves SL1, SL2, SL3 are output.
In the mode shown in the table, excitation is selectively performed to control the shift stage of the automatic transmission AT to shift to a higher shift stage (shift up) or a lower shift stage (shift down), and a shift down signal Cp A signal Sr indicating that this output is performed is output to the lockup control circuit 201 prior to the output of '.

Further, in the lockup control circuit 201 of the control unit 200, as in the case of the shift control circuit 202 described above, the turbine rotation speed St from the turbine rotation speed sensor TS, the throttle opening signal Sn from the engine load sensor LS, and the traveling The information provided by the mode signal is compared with the lock-up operation line and the lock-up release line of the shift map which is predetermined based on, for example, the turbine speed-engine load characteristic as shown in FIG. Calculate whether or not the lockup should be released. Then, according to the result of this calculation, the lockup operation signal Cq or the lockup release signal Cq 'is output to the fourth solenoid valve SL4 of the hydraulic control circuit CK.

As described above, the shift-up is performed based on the shift-up signal Cp and the shift-down is performed based on the shift-down signal Cp ′, and the lock-up operation is changed to the lock-up release signal Cq ′ based on the lock-up operation signal Cq. The lock-up is released based on the lock-up release signal.
It is characterized by the output timing with q ', and this point will be described in detail below.

Now, in the state where the lock-up operation is performed according to the lock-up operation line in FIG. 4, it is assumed that the turbine rotational speed TSP 'with respect to the throttle opening TH' at that time exceeds the shift-down gear shift line shown in FIG. In this case, the shift control circuit 202 outputs the signal Sr to the lockup control circuit 201 and immediately outputs the lockup release signal Cq ′ to the fourth solenoid valve SL4 of the hydraulic control circuit CK, and The shift down signal Cp ′ is output at the timing described later with respect to the output of the up release signal Cq ′.
Is the first, second and third solenoid valves AS of the hydraulic control circuit CK
Output to L1, SL2, SL3.

When a signal indicating that the engine speed is in a downward trend (dTSP / dt <0) is output from the change state detection circuit 205 to the shift control circuit 202 at the time of downshifting, it is shown in FIG. As described above, first, the lockup control circuit 201 outputs the lockup release signal Cq ′ for the fourth solenoid valve SL4, and the lockup release signal Cq ′ is output.
The shift-down signal Cp ′ is output at a time t ₂ which is delayed from the time t ₁ at which is output. The delay of the shift-down signal output is set until the engine speed ESP of the engine output shaft 1 tends to increase so that a shift shock is unlikely to occur. As a result, unpleasant shift shock is more reliably prevented.

In addition, the above engine speed tends to increase (dTSP / dt ≧ 0)
When in, as shown in FIG. 14, in 'the down-shifting signal Cp' the lock-up release signal Cq and is synchronized (at time t ₁₎ is output. As a result, the downshift is quickly performed (completed), and the shift responsiveness becomes good. Of course, in this case, since the engine speed tends to increase, the shift shock is not likely to occur originally or is small even if it occurs, and as described above, the shift shock itself does not tend to be uncomfortable for the driver. Therefore, the shift feeling is improved as much as the shift responsiveness is improved.

Note that both the case of both rising or downward trend of the engine speed is returned to the lock-up operating state again when it becomes time t _3.

The control unit 200 that performs the above-described control can be configured by, for example, a microcomputer,
The operation program of the microcomputer constituting the control unit 200 is executed according to the flowcharts shown in FIGS. 5 to 12, for example. The flowchart will be sequentially described below.

Overall Control FIG. 5 shows an overall flowchart of the shift control, and the shift control is first performed from the initialization setting in step S1 as can be seen from this figure. This initialization setting initializes the port of each control valve for switching the hydraulic control circuit of the automatic transmission and the necessary counter to set the gear transmission mechanism 20 to the first speed and the lockup clutch.
Set 15 to release respectively. After this, the control unit 20
Completed by initializing 0 working areas.

Next, in step S2, the position of the select valve 103, that is, the shift range is read. Then, in step S3, it is determined whether or not the read shift range is "1 range". When the shift range is "1 range", the lockup is released in step S4, and then 1 in step S5.
Shift down to speed and calculate if the engine overruns. When it is determined in step S6 that the vehicle is overrun, the shift valve is controlled so that the gear transmission 20 is shifted to the second speed in step S7. When it is determined that the vehicle will not overrun, the gear is shifted to the first speed in step S8 to prevent a shift shock.

If the shift range is not "1 range" in step S3, it is determined in step S9 whether the shift range is "2 range". When the shift range is "2 range", the lockup is released in step S10, and then the gear is shifted to the second speed in step S11. On the other hand, if it is determined in step S9 that the shift range is not "2 range", it means that the shift range is eventually in the D range. In this case, the shift-up control in step S12 and step S13 will be described later. The shift-down control in step S14 and the lock-up control in step S14 are sequentially performed.

When steps S7, S8, S11 and S14 are completed as described above, the process returns to step S2 and the above-described routine is repeated.

Shift-up control Next, the shift-up control (step S1 in FIG. 5)
2) will be described in detail with reference to FIG.

First, the gear position, that is, the position of the gear shift mechanism 20 is read out. Next, based on the read gear position, it is determined in step S21 whether the vehicle is currently in fourth gear. If it is not the fourth speed, the current throttle opening TH 'is read in step S22, and the shift-up map data TSP ₁ corresponding to the throttle opening is read in step S23. Seventh example of this shift map
Shown in the figure. Next, at step S24, the current turbine speed TS
P'is read out and this present turbine speed TSP 'is
Light of the data TSP ₁ upshift map read above, whether the current turbine speed TSP 'is set greater than the turbine speed TSP ₁ shown in shift line MFU ₁ in relation to the throttle opening degree at Step S25 To judge.

When the current turbine rotational speed TSP 'is larger than the set turbine rotational speed TSP _{1 in} relation to the throttle opening TH, the flag 1 for upshifting by one step is read out in step S26, and this is read out. Flag 1 is 0 or 1
That is, it is determined whether it is in the reset state or the set state. The flag 1 is changed from 0 to 1 when the 1-step shift-up is executed. When the flag 1 which stores the 1-step shift-up state is in the reset state, after the flag 1 is set to 1 in step S27 , Upshift is performed in step S87, and the 1-step upshift control is completed.

When it is determined in step S26 whether the flag 1 in the one-stage upshift control system is 1 or not,
The control is completed as it is.

Also, when it is determined that the vehicle is in the 4th speed in the first stage, the control is completed as it is. Further steps
At S25, the current turbine speed TSP 'is the throttle opening TH
When it is determined that the turbine rotation speed TSP ₁ indicated by the shift line Mfu ₁ is not greater than
In step S29, TSP ₁ is multiplied by 0.8, for example, to set a new set turbine speed TSP ₂ on the new shift line Mfu ₂ shown by the broken line in FIG. Next, at step S30, it is determined whether or not the current turbine speed TSP 'is larger than the set turbine speed TSP ₂ indicated by the speed change Mfu ₂ and TSP'.
If TSP ₂ is larger than TSP ₂ , flag 1 is reset in step S31 to prepare for the next cycle, and conversely TSP '.
If TSP ₂ is not greater than this, then shift down control is performed.

Shift Down Control The shift down control (step S13 in FIG. 5) is executed according to the shift down shift control subroutine shown in FIG. This downshift control is performed by first reading out the gear position, as in the upshift control. Next, based on the read gear position, it is determined in step S41 whether the vehicle is currently in the first speed. If it is not the first speed, the throttle opening TH is read in step S42, and then the downshift map data TSP ₁ corresponding to the read throttle opening TH is read in step S43. An example of this shift down map is shown in FIG. Next, in step S44, the current turbine speed TSP 'is read and this turbine speed TSP' is
In light of the set turbine speed TSP ₁ which is the data of the read downshift map, the current turbine speed TSP 'is related to the throttle opening TH, and the set turbine speed TSP indicated by the downshift transmission line Mfd ₁ is shown. It is determined in step S45 whether it is smaller than ₁ .

When the current turbine speed TSP 'is smaller than the set turbine speed TSP ₁ reads the flag 2 for 1 downshifting in step S46. The flag 2 is changed from 0 to 1 when downshifting one step.

Next, it is determined whether this flag 2 is 0 or 1, that is, whether it is in the reset state or the set state. When the flag 2 is in the reset state, the flag 2 is set to 1 in step S47, the 1-step downshift is performed in step S48, and the 1-step downshift control is completed.

When it is determined in step S46 that the flag 2 is in the set state, downshifting is impossible, so the control is completed as it is.

In step S45, the current turbine speed TS
When it is determined that P'is not less than the set turbine speed TSP ₁ shown on the _1st downshift transmission line Mfd ₁ ,
A shift-down map corresponding to the current throttle opening is read out, and in step S49, the set turbine speed TSP ₁ shown on the shift line Mfd ₁ of this map is multiplied by, for example, 1 / 0.8,
New setting on a new shift line Mfd ₂ turbine speed TSP ₂
To set. Then, when the current turbine speed TSP 'is smaller than the set turbine speed TSP ₂ shown above shift line Mfd ₂ in step S50, it completes the control,
If it is not smaller, the flag 2 is reset to 0 in step S51, the control is completed, and then the lockup control is performed.

In the above-described shift-up shift control and shift-down shift control, when gear shifting is not performed,
It is the engine speed that creates a new shift line by multiplying the shift line on the map by 0.8 or 1 / 0.8 to create hysteresis.
This is to prevent chattering from occurring due to frequent gear shifts when the turbine speed is at the critical gear shift.

Lockup Control Next, the lockup control will be described with reference to FIG. 10 (step S14 in FIG. 5).

First, in the lockup control, the current throttle opening TH ′ is read in step S61, and then in step S62, the lockup OFF map, that is, the shift used for the control for turning the lockup to the OFF (release) state. Line Moff (No.
From the map shown in (Fig. 11), the set turbine speed TSP ₁ corresponding to the throttle opening is read. Next, in step S63, the current turbine speed TSP 'is read, and in step S64, the read current turbine speed TS is read.
By comparing P ′ with the lockup OFF map, it is determined whether or not the present turbine speed TSP ′ is larger than the set turbine speed TSP ₁ shown on the shift line MOFF. The current turbine speed TSP 'is the set turbine speed TSP ₁
If it is smaller than the above, the lockup is released in step S65 and the process ends.

On the other hand, if the current turbine speed TSP 'is larger than the set turbine speed TSP ₁ , the lockup ON map, that is, the lockup is turned ON (operation) in step S66.
Another set turbine speed TSP ₂ corresponding to the throttle opening TH is read from the map showing the shift line Mon (see FIG. 11) used for the control to bring the state into the state, and then at step S67, the current turbine speed TSP ₂ is read. whether turbine speed TSP 'is greater than the set turbine speed TSP ₂ is determined. Then, TSP 'when people from the TSP ₂ is large, while ending by operating the lock-up at step S68, TSP'
If TSP ₂ is not larger than TSP ₂ , the process ends.

Lock-up control during shift-down The output timing of the shift-down signal and the lock-up release signal when the shift-down signal is output during the lock-up operation is adjusted by the subroutine shown in FIG.

First, in step S81, the contents of step S48 (see FIG. 8) are read. Next, in step S82, it is determined whether or not the read content in step S81 is downshift, and if not downshift, the control ends as it is. On the other hand, if it is determined in step S82 that the gear is downshifted, it is determined in step S83 whether or not it is in the lockup operating state, and if it is determined that it is not in the lockup operating state, the control is terminated and the lock is performed. If it is determined that the lockup operation is being performed, the lockup release signal Cq ′ is output in step S84.

After that, in step S85, it is determined whether or not the engine speed is increasing, that is, dTSP / dt ≧ 0. If the engine speed is increasing, that is, if dTSP / dt ≧ 0, the downshift signal Cp ′ is output in step S86. Further, if dTSP / dt ≧ 0, that is, if the engine speed tends to decrease, the engine speed ESP in step S87 (the engine speed in this step S87 is not substituted by the turbine speed) tends to increase. Wait until it becomes, and if ESP tends to increase with this engine speed, step S86
Then, the shift down signal Cp 'is output.

Thus, when the engine speed is increasing, the shift-down signal output and the lock-up release signal Cq 'are output in synchronization, and when the engine speed is decreasing, the engine speed ESP is increased. The shift-down signal Cp 'is output later than the output of the lock-up release signal Cq' until the time point when the signal has a rising tendency.

Although the embodiments have been described above, when the electronic control circuit 200 is configured by a microcomputer, it can be configured by either a digital type or an analog type. In order to know whether the engine speed is increasing or decreasing, it is possible to look at the acceleration obtained by further differentiating dTSP / dt. In this case, the engine speed increases. It is possible to know the time when the tendency or the downward tendency is shifted, which is preferable for improving the responsiveness. Furthermore, as the engine load,
It can be detected by an appropriate means such as the intake pressure and the amount of depression of the accelerator pedal.
It can be detected by the number of revolutions of the engine output shaft itself or the number of revolutions of the output shaft of the gear type speed change mechanism 20 in addition to the number of revolutions of the turbine.

(Effects of the Invention) As is apparent from the above description, the present invention is capable of enhancing the gear shift responsiveness while more reliably preventing unpleasant gear shift shocks during downshifts, and is extremely excellent in gear shifting feeling. Is obtained.

Further, the control for preventing the shift shock and improving the shift responsiveness is performed depending on whether the engine speed is increasing or decreasing, in other words, the shift is performed such that an uncomfortable shift shock is generated. Since it is possible to directly know whether or not, it is possible to obtain a preferable one for ensuring the accuracy of control.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of the present invention. FIG. 2 is a view showing a cross section of a mechanical portion of an automatic transmission and a hydraulic circuit thereof. FIG. 3 is an overall system diagram showing an embodiment of the present invention. FIG. 4 is a diagram showing an example of a shift diagram. FIG. 5, FIG. 6, FIG. 8, FIG. 10, and FIG. 12 are flowcharts showing an example of the control contents of the present invention. FIG. 7 is a diagram showing an example of a shift-up map. FIG. 9 is a diagram showing an example of a shift-down map. FIG. 11 is a diagram showing an example of a lockup map. FIG. 13 is a diagram showing the output timings of the lock-up release signal and the shift-down signal when the engine speed tends to decrease in the relationship between the engine speed and the turbine speed. FIG. 14 is a diagram showing the output timings of the lock-up release signal and the shift-down signal when the engine speed is on the rise in relation to the engine speed and the turbine speed. 1: Engine output shaft 10: Torque converter 14: Torque converter output shaft 15: Lockup clutch 20: Multi-stage gear shifting mechanism 200: Control unit 201: Lockup control circuit 202: Shift control circuit 205: Change state detection circuit EN: Engine SL1 to SL4: Solenoid valve ESP: Engine speed TSP: Turbine speed

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiji Yashiki No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) References JP-A-57-76359 (JP, A) JP-A-57- 6151 (JP, A)

Claims (1)

[Claims] 1. A torque converter connected to an engine output shaft, a gear type speed change mechanism connected to the output shaft of the torque converter, and a lockup mechanism for connecting and disconnecting the engine output shaft and the output shaft of the torque converter. An electromagnetic means for shifting which controls the supply of a pressure flow pair to a fluid type actuator which carries out a gear shifting operation of the gear type gear shifting mechanism; and a supply of pressure fluid to a fluid type actuator which carries out an intermittent operation of the lockup mechanism. Based on the lock-up electromagnetic means, a shift control means for outputting a shift-up signal or a shift-down signal to the shift electromagnetic means on the basis of a predetermined shift characteristic, and on the basis of a predetermined lock-up characteristic. , A lockup signal or lock for the lockup electromagnetic means Lockup control means for outputting a lockup release signal, rotation speed detection means for detecting the rotation speed of the engine output shaft, and the rotation speed when a downshift signal is output to the shifting electromagnetic means in the lockup state. On the basis of the signal from the number detecting means, when the engine output shaft rotational speed tends to increase, the downshift signal and the lockup release signal are output in synchronization, and the engine output shaft rotational speed tends to decrease. Control means for outputting the lockup release signal and an output timing adjusting means for outputting the downshift signal after the lockup release signal is output. .