JPH0242149B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a control device for an automatic transmission, and more particularly to a control device for an automatic transmission used in a traveling vehicle such as an automobile. BACKGROUND OF THE INVENTION Automatic transmissions commonly used today are constructed by combining a torque converter and a multi-stage gear type transmission mechanism having a gear mechanism such as a planetary gear mechanism. A hydraulic mechanism is normally used for speed change control of such automatic transmissions, and the hydraulic circuit is switched using a mechanical or electromagnetic switching valve, thereby reducing the friction of the brakes, clutches, etc. associated with the multi-gear type transmission mechanism. The engine power transmission system is switched by operating elements as appropriate to obtain the desired gear position.
When switching the hydraulic circuit using an electromagnetic switching valve, an electronic device detects when the vehicle's running state exceeds a predetermined shift line, and a signal from this device is used to switch the electromagnetic switching valve. It is common practice to selectively operate the hydraulic circuit and thereby change the speed by switching the hydraulic circuit. In conventional systems, the above-mentioned shift line is determined using vehicle speed-engine load characteristics as a control parameter, but since vehicle speed is a control parameter via the transmission, a different pattern is created for each gear. Therefore, control becomes complicated. In addition, since the engine load is detected by detecting the throttle opening, which is normally set in stages, if the above-mentioned shift line is made into a step shape, the difference between this step-shaped shift line and the engine There are parts where the deviation between the rotational speed and torque characteristics, that is, the engine characteristics, becomes quite large. This is particularly noticeable when the quantized data used is coarse. In order to eliminate the above-described drawbacks of the conventional apparatus, Japanese Patent Publication No. 56-44312 and other publications propose a system that uses the turbine speed-engine load characteristic as the parameter for determining the shift line. In this way, the turbine speed-engine load characteristic is used as a control parameter.
Since data via the transmission is not used, only one shift line is required, and even if the throttle opening changes, etc.
Turbine rotation is stable with relatively little fluctuation, so there is little hysteresis between the shift-up line, the down-shift line, and the lock-up cut line, and there is no limit line such as a stall line, so it is difficult to set the shift line. It has the advantage of having a large degree of freedom. Purpose of the Invention The present invention provides a control device for an automatic transmission of the type that uses the turbine speed-engine load characteristic as a control parameter, which can set gears so that the vehicle can always operate in a region with good accelerator response. An object of the present invention is to provide a control device for an automatic transmission that can improve performance. Development of the Invention and Structure of the Invention Figure 1 shows that the output shaft torque of the engine is 0.1Kg・m, 2Kg・m, 3Kg・m when the engine is rotated without applying any load.
Figure 1 shows the engine speed vs. throttle opening characteristic when the engine speed is held constant. When the throttle opening is high, there is a region where the throttle opening does not increase as the throttle opening increases. Therefore, there is a high throttle opening range in which the generated power does not increase. That is, the second
The figure is a graph showing the turbine rotation speed vs. throttle opening characteristic when the power generated by the engine with the torque characteristics shown in Figure 1 is constant at 0.5KW, 10KW, 15KW, etc. As shown, each equal power line has an inflection point, and at lower rotations than the power inflection line P connecting these inflection points (second
In the upper left zone of the power curve P in the diagram), no matter how much the throttle opening is increased, the generated power does not increase and remains constant, resulting in poor accelerator response. Therefore, as shown in FIG. 2, the present invention calculates a power inflection curve P, which is a line connecting the inflection curves of each equal power characteristic curve of engine output, and
Shift control is performed based on this power variation curve P. That is, as shown in FIG. 3, the automatic transmission control device according to the present invention includes a torque converter connected to the output shaft of the engine, a speed change gear mechanism connected to the output shaft of the torque converter,
A speed change switching means for switching the power transmission path of the speed change gear mechanism to perform a speed change operation, and an electromagnetic means for controlling the supply of pressure fluid to a hydraulic actuator that operates the speed change switching means, the electromagnetic means being driven and controlled to perform a speed change operation. In an automatic transmission that performs In each equal power characteristic curve, which connects points where the generated power is equal for each output level, there is a line that connects the inflection point where the ratio of change in engine generated power to changes in engine load changes from a large state to a small state. Calculated based on the downshift line and the difference in gear ratio between adjacent gears, which is set to define a region where the engine power increases and a region where it does not increase as the engine load increases. a shift line setting means that stores a shift up shift line that has a width larger than a rotation speed fluctuation range of the output shaft of the torque converter and is set on a higher rotation side than the shift down shift line; and the turbine rotation speed sensor. and the output signal of the engine load sensor, and compare these output signals with the downshift shift line stored in the shift line setting means, so that the operating state represented by both signals is determined to be the downshift shift line. a shift-down determining means for issuing a shift-down command signal when it is determined that the generated power on the low rotation or high load side is within an operating range in which it does not increase; an output signal of the turbine rotation speed sensor and an engine load sensor; Upon receiving the output signals, these output signals are compared with the shift-up shift line stored in the shift line setting means, and it is determined whether the operating state represented by the two output signals is on the higher rotation or lower load side than the shift-up shift line. a shift-up discriminator that issues a shift-up command signal when determining that the shift-up is within the operating range; and a shift-up discriminator that receives a shift-down command signal from the shift-down discriminator and a shift-up command signal from the shift-up discriminator, and based on these two command signals; The present invention is characterized in that it includes a drive means that automatically changes speed by driving and controlling the electromagnetic means. Effects of the Invention In the automatic transmission control device of the present invention configured as described above, the downshift line is expressed based on the turbine rotational speed and the engine load, and the point where the engine generated power is equal is determined for each output level. It corresponds substantially to the line connecting the inflection points of the equal power characteristic curves where the ratio of the change in turbine speed to the change in engine load changes from a large state to a small state, and the engine speed increases as the engine load increases. Shift down control is performed using a shift line that is set to delineate areas where the generated power increases and areas where it does not increase, so when you press the accelerator, the generated power always increases in proportion to the amount of pedal depression. It is possible to drive in a region with increased accelerator response, and it is possible to improve driving performance. In addition,
In a high speed gear, for example, 3rd speed, the shift-up shift line is limited to the low rotation side by the 3rd speed running resistance line A, so it is necessary to correct the shift-down shift line accordingly. Embodiments Hereinafter, a control device for an automatic transmission according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 4 is a diagram showing a cross section of a mechanical part of an automatic transmission incorporating a control device according to an embodiment of the present invention and a hydraulic control circuit. Structure of Automatic Transmission The automatic transmission includes a torque converter 10, a multi-stage gear transmission mechanism 20, and an overdrive planetary gear transmission mechanism 50 disposed between the torque converter 10 and the multi-stage gear transmission mechanism 20. has been done. The torque converter 10 includes a pump 11 coupled to an engine output shaft 1, a turbine 12 disposed opposite the pump 11, and a stator 13 disposed between the pump 11 and the turbine 12. A converter output shaft 14 is coupled to the converter output shaft 14 . Converter output shaft 14 and pump 1
A lock-up clutch 15 is provided between the lock-up clutch 1 and the lock-up clutch 15. This lockup clutch 15 is
The clutch 1 is constantly pushed in the engagement direction by hydraulic oil pressure circulating within the torque converter 10.
5 is maintained in the open state by the opening hydraulic pressure supplied from the outside. The multi-stage gear transmission mechanism 20 includes a front planetary gear mechanism 2
1 and a rear planetary gear mechanism 22, and a sun gear 23 of the front planetary gear mechanism 21 and a rear planetary gear mechanism 22.
It is connected to the sun gear 24 by a connecting shaft 25. The input shaft 26 of the multi-stage gear transmission mechanism 20 is connected to the connecting shaft 25 via a front clutch 27 and to the internal gear 29 of the front planetary gear mechanism 21 via a rear clutch 28, respectively. The connecting shaft 25, that is, the sun gear 23,
24 and the transmission case is the front brake 30.
is provided. The planetary carrier 31 of the front planetary gear mechanism 21 and the internal gear 33 of the rear planetary gear mechanism 22 are connected to an output shaft 34, and a rear brake 36 is connected between the planetary carrier 35 of the rear planetary gear mechanism 22 and the transmission case.
A one-way clutch 37 is provided. The overdrive planetary gear transmission mechanism 50 is
A planetary carrier 52 that rotatably supports a planetary gear 51 is connected to the output shaft 14 of the torque converter 10, and a sun gear 53 is connected to an internal gear 55 via a direct coupling clutch 54. An overdrive brake 56 is provided between the sun gear 53 and the transmission case, and the internal gear 55 is connected to the input shaft 26 of the multi-gear transmission mechanism 20. The multi-gear transmission mechanism 20 is of a conventionally known type and has three forward speeds and one reverse speed.
28 and the brakes 30 and 31 as appropriate, a desired gear stage can be obtained. The overdrive planetary gear transmission mechanism 50 is
When the direct coupling clutch 54 is engaged and the brake 56 is released, the shafts 14 and 26 are coupled in direct coupling, and when the brake 56 is engaged and the clutch 54 is released, the shafts 14 and 26 are coupled in overdrive. Hydraulic Control Circuit The automatic transmission described above is equipped with a hydraulic control circuit as shown in FIG. This hydraulic control circuit includes an oil pump 100 driven by an engine output shaft 1.
The pressure of the hydraulic oil discharged into the pressure line 101 is regulated by the pressure regulating valve 102 and the pressure is adjusted by the select valve 1.
Guided to 03. The select valve 103 has 1, 2,
The pressure line 101 has shift positions D, N, R, and P, and the pressure line 101 communicates with ports a, b, and c of the valve 103 when the select valve is in the 1, 2, and P positions. Port a is connected to an actuator 104 for actuating the rear clutch 28, which is held engaged when the valve 103 is in the position described above. Port a is also connected near the left end of the 1-2 shift valve 110, pushing its spool to the right in the figure. port a
is further connected to the right end of the 1-2 shift valve 110 via the first line L1 and to the 2-2 shift valve 110 via the second line L2.
The right end of the 3-shift valve 120 is connected to the upper end of the 3-4 shift valve 130 via the third line L3. From the first, second and third lines L1, L2 and L3, the first, second and third lines L1, L2 and L3 respectively
Second and third drain lines D1, D2 and D
3 are branched, and these drain lines D1,
D2, D3 have these drain lines D1, D2,
First, second, and third solenoid valves SL1, SL2, and SL3 are connected to open and close D3. The above solenoid valves SL1, SL2, SL3 are connected to line 101.
When the drain lines D1, D2, and D3 are energized while communicating with the port a, the drain lines D1, D2, and D3 are closed, thereby increasing the pressure in the first, second, and third lines. Port b is also connected to second lock valve 105 via line 140, and this pressure acts to force the spool of valve 105 downward in the figure. When the spool of the valve 105 is in the lower position, lines 140 and 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 second lock valve 1
05, and this pressure acts to push the spool of the valve 105 upward. Further, port c is connected to a 2-3 shift valve 120 via a pressure line 106. This line 106
is the solenoid valve SL2 of the second drain line D2
is energized to increase the pressure in the second line L2, and when this pressure moves the spool of the 2-3 shift valve 120 to the left, the line 107
communicate with. The line 107 is connected to the release side pressure chamber of the front brake actuator 108, and when hydraulic pressure is introduced into the pressure chamber, the actuator 108 moves the brake 3
0 in the release direction. Also, line 107
The pressure of actuator 1 of front clutch 27 is
09, and this clutch 27 is engaged. Select valve 103 has a port d that communicates with pressure line 101 in the 1 position, which port d communicates with 1-2 shift valve 110 via line 112.
Rear brake 3 is reached and passes through line 113.
6 actuator 114. 1-2
When the solenoid valves SL1 and SL2 are energized by a predetermined signal, the shift valves 110 and 2-3 shift valves 120 move the spools to switch lines, thereby actuating a predetermined brake or clutch. -2 and 2-3 speed change operations are performed. In addition, a pressure regulating valve 102 is included in the hydraulic control circuit.
Cutback valve 11 that stabilizes the oil pressure from
5. 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 back-up valve 117 that assists the throttle valve 116 are provided.
Furthermore, the hydraulic control circuit of this example includes a 3-4 shift valve 1 to control a clutch 54 and a brake 56 of an overdrive planetary gear transmission mechanism 50.
30 and an actuator 132 are provided. The engagement side pressure chamber of the actuator 132 is connected to the pressure line 101.
The brake 56 is pushed in the engaging direction by the pressure. This 3-4 shift valve is also 1-2, 2-3 above.
Similar to the shift valves 110 and 120, solenoid valves
When SL3 is energized, the spool 13 of the valve 130
1 moves downward, pressure line 101 and line 1
22 is shut off and line 122 is drained. This eliminates the hydraulic pressure acting on the release side pressure chamber of the actuator 132 of the brake 56, causing the brake 56 to operate in the engaging direction and the actuator 134 of the clutch 54 acting to release the clutch 54. Further, the hydraulic control circuit of this example is provided with a lock-up control valve 133, which is connected to the select valve 1 via a line L4.
It is connected to port a of 03. This line L
A drain line D4 is branched from the drain line D4 and is provided with a solenoid valve SL4, similar to the drain lines D1, D2, and D3. Lockup control valve 13
3, when the solenoid valve SL4 is energized, the drain line D4 is closed, and the pressure in the line L4 increases, the spool blocks the lines 123 and 124, and the line 124 is drained. The lock-up clutch 15 is moved in the connecting direction. In the above configuration, the operational relationship between each gear, the lockup, and each solenoid, and the operational relationship between each gear and the clutch and brake are shown in the following table.

【table】

【table】

【table】

[Table] Electronic control circuit using a microcomputer Next, referring to FIG. 5, an electronic control circuit 200 for controlling the operation of the hydraulic control circuit will be described. The electronic control circuit 200 includes an input/output device 201, a random access memory 202 (hereinafter referred to as RAM), and a central processing unit 203 (hereinafter referred to as CPU). The input/output device 201 includes a load sensor 207 that detects the engine load from the opening degree of a throttle valve 206 provided in the intake passage 205 of the engine 204 and outputs a load signal SL, and a rotation of the converter output shaft 14. Sensors for detecting running conditions, such as a turbine rotation speed sensor 209 that detects the number of rotations and outputs a turbine rotation speed signal ST, are connected, and the above-mentioned signals and the like are inputted from these sensors. The input/output device 201 processes the load signal SL and turbine rotation speed signal ST received from the sensor, and
Supplied to RAM202. The RAM 202 stores these signals SL and ST, and also stores the signals SL and ST.
These signals SL, ST in response to commands from 203
Or other data is supplied to the CPU 203.
The CPU 203 outputs the turbine rotation speed signal ST according to a program that is compatible with the speed change control of the present invention.
For example, the fifth
Based on the 1-2 shift-up transmission line Lu1, 2-3 and 3-4 shift-up transmission line Lu2, and the shift-down transmission line Ld determined based on the turbine rotation speed-engine load characteristics as shown in Figure A. , performs a calculation as to whether or not the gear should be changed. The above-mentioned downshift shift line Ld is expressed based on the turbine rotation speed and engine load as described above. It is determined based on the line P in FIG. 2 that connects inflection points where the rate of change in the turbine rotational speed changes from a large state to a small state. In other words, as mentioned above, the shift-up line is limited by the 3rd speed running resistance line A at a throttle opening of about 60% or more, and the throttle opening at an extremely low load of about 10%.
In zones other than the following zones, the line P
The downshift line Ld is made to match. In addition, the shift-up speed change lines Lu1 and Lu2 are the rotational speed fluctuation range H of the output shaft of the torque converter 10 calculated according to the difference in gear ratio between each adjacent gear stage of the speed change gear mechanism [H=Tnd・Am/ Gn, where Tnd = turbine rotational speed at the downshift point, Gn: gear ratio of nth gear, Am: difference in gear ratio between nth gear and the adjacent lower gear]. It is set on the higher rotation side than the gear shift line. Therefore, the turbine rotational speed after the shift does not change from the downshift zone to the upshift zone or from the upshift zone to the downshift zone, and the shift can be performed without hunting caused by repeated upshifts and downshifts. Note that the speed change map shown in FIG. 5A is 1-
2 shift up transmission lines Lu1, 2-3 and 3-
However, as shown in FIG. 5B, the map used in the present invention has a 2-2 shift-up line Lu1 instead of a 1-2 shift-up line Lu1.
-1 shift down shift line Ld1 may be provided. This 2-1 shift down shift line Ld
1 is 2-3 and 3-4 shift up transmission line
The rotation speed is set to be lower than Lu2 by the rotation speed fluctuation range H. The calculation results of the CPU 203 are sent to the input/output device 201
and the 1-2 shift valve 11, which is the speed change control valve described with reference to FIG. 4, via the drive circuit 211.
0, 2-3 shift valve 120, 3-4 shift valve 13
0 and is given as a signal to control the excitation of the solenoid valve group 211 that operates the lock-up control valve 133. This solenoid valve 211 includes solenoid valves SL1, SL2, SL3, and SL4 of a 1-2 shift valve 110, a 2-3 shift valve 120, a 3-4 shift valve 130, and a lock-up control valve 133. An example of control of an automatic transmission by the electronic control circuit 200 will be described below. Electronic control circuit 200
It is preferable that the electronic control circuit 200 is configured by a microcomputer, and a program installed in the electronic control circuit 200 is executed according to, for example, the flowchart shown in FIG. 6 and subsequent figures. FIG. 6 shows an overall flowchart of the shift control, and as can be seen from this figure, the shift control is first performed from initialization settings. This initialization setting is performed by first initializing the ports of each control valve that switches the hydraulic control circuit of the automatic transmission and the necessary counters, and then starting the gear transmission mechanism 20.
is set to first gear, and the lock-up clutch 15 is set to released. Thereafter, various working areas of the electronic control circuit 200 are initialized to complete the initialization settings. After this initialization setting, a step is performed to read the position of the select valve 103, that is, the shift range. Next, it is determined whether the read shift range is the D range. When this determination is No, it is determined whether the shift range is 2 ranges or not. When this determination is YES, that is, when the shift range is 2nd range, a signal is generated to control the shift valve so as to release the lockup and fix the gear transmission mechanism 20 at the 2nd speed. On the other hand, when the above judgment of 2nd range is No, the shift range is 1st range, so first release the lockup, then calculate whether the engine will overrun when downshifting to 1st gear. . After this, based on this calculation, it is determined whether or not overrun will occur, and if this determination is No, the gear is shifted to 1st gear,
When this determination is YES, the gear is shifted to the second speed. On the other hand, when the determination as to whether the vehicle is in the D range is YES, a shift and lockup map including a shift change control line and a lockup control line is set. Next, shift-up speed change control including a shift-up determination is performed. This shift-up speed change control is executed according to the shift-up speed change control subroutine shown in FIG. In this embodiment, shifting of the multi-stage gear transmission 20 to the reverse, neutral, and parking states is performed by switching the hydraulic circuit by operating the select valve 103. Shift-up speed change control As shown in FIG. 7, this shift-up speed change control first reads out the gear position, that is, the position of the gear transmission mechanism 20, and then, based on this read gear position, determines whether or not it is currently in the fourth gear. It starts with doing. This judgment
When YES, flag 1 and flag 2 cannot be shifted up any further.
is reset, that is, to 0, and the control is terminated. Flag 1 and flag 2 are set when a one-stage shift up and a skip shift up are executed, respectively, and are used to store the shift up state. On the other hand, if the determination as to whether the vehicle is in fourth gear is No, it is determined whether flag 1 is in the reset state, that is, in the "0" state, and if this determination is YES,
A determination is made as to whether or not the vehicle is in the first speed. When this judgment is YES, the 1-2 shift up shift line Lu1 (see Fig. 8) for shifting up from 1st speed to 2nd speed is selected and read out.On the other hand, when this judgment is No, the From 2nd gear to 3rd gear,
In addition, the 2-3 and 3-4 shift up transmission lines Lu2 are used to shift up from 3rd speed to 4th speed.
(See Figure 8) and read out. Next, the turbine rotation speed (Tsp) is read out, and this turbine rotation speed is applied to the 1st shift up transmission line read above.
Lu1 or Lu2 [Storing the data of the shift-up points set on the shift-up shift lines Lu1 and Lu2 in Fig. 5A (for example, using the throttle opening θ as an address and storing the corresponding turbine rotation speed N)
], it is determined whether the turbine rotation speed is smaller than the set turbine rotation speed indicated by the first-stage shift-up transmission line Lu1 or Lu2 in relation to the throttle opening. This judgment is No
If this is the case, control is completed as is, and this judgment is
If YES, flag 1 is set and a command to shift up by one gear is issued. If the determination of flag 1 = 0 is No, read the 1st gear up shift line Lu1, multiply this shift line Lu1 by 0.8 to 0.95, and create a new shift line with hysteresis (not shown). Form. Next, the actual turbine rotation speed Tsp is read out, and it is determined whether or not this turbine rotation speed Tsp is smaller than the above-mentioned new shift line in relation to the throttle opening. If this determination is YES, flag 1 and flag 2 are reset to complete the control, while if this determination is NO, it is determined whether flag 2 is 0 or not. When this judgment is YES,
Next, it is determined whether the current gear position is the second gear. When this determination is YES, the 2-4 skip shift up shift line Lu for performing a skip shift up from 2nd speed to 4th speed is set.
3 is selected and read out. On the other hand, when this determination is No, a 1-3 skip shift up shift line Lu4 for performing a skip shift up from the first speed to the third speed is selected and read out. Next, the turbine rotation speed Tsp read out is compared with the 2-4 skip shift up transmission line Lu3 or the 1-3 skip shift up transmission line Lu4, and the turbine rotation speed Tsp is determined in relation to the throttle opening. Skip shift up line
It is determined whether or not the turbine rotation speed is greater than the set turbine rotation speed indicated by Lu3 or Lu4. If this judgment is No, control is completed as is;
If YES, flag 2 is set and a command for two-stage shift up is issued. If the determination of flag 2 = 0 is No, 1-4 skip shift up shift line Lu5 for 3-speed skip shift up from 1st speed to 4th speed.
Select and read. Next, it is determined whether or not the read turbine rotation speed Tsp is larger than the set turbine rotation speed indicated by the shift line Lu5 in relation to the throttle opening. This judgment
If the determination is No, the control is completed as is, while if the determination is YES, a command to shift up to 4th gear is issued. When the command for upshifting is issued, it is then determined whether a command for upshifting to fourth gear is included. When this judgment is No, the control is completed as is, while when this judgment is YES, the engine state is
It is determined whether the vehicle is in a state suitable for upshifting to a higher speed. This determination is made by first reading the engine cooling water temperature, and then determining whether or not this cooling water temperature is low. This judgment
If YES, the engine has not yet warmed up sufficiently, so a command is issued to prohibit upshifting to 4th gear, and control is completed. On the other hand, if the determination as to whether the temperature is low is No, a fourth speed flag indicating that the gear is shifted up to fourth speed is set, and the control is completed. With the above steps, all subroutines for shift-up speed change control are completed. Downshift Control The downshift control is executed according to the downshift control subroutine shown in FIG. This shift-down speed change control is performed by first reading out the gear position, as in the case of shift-up speed change control. Next, based on this read gear position, it is determined whether or not the vehicle is currently in the first gear. If this judgment is YES,
Since no further downshift can be performed, flag A and flag B are reset, that is, set to 0, and the control is terminated. Flag A and flag B are set to "1" when a one-stage downshift and a skip downshift are executed, respectively, to store the upshift state. On the other hand, if the determination as to whether the vehicle is in the first gear is No, it is determined whether the flag A is in the reset state, that is, in the "0" state, and if this determination is YES,
To perform a 1st gear downshift, store the data of the shift down point set by the 1st gear downshift line Ld1 in Figure 10 (the downshift line Ld in Figure 5A (for example, use the throttle opening θ as an address). , the corresponding turbine rotational speed N is stored) and read out. Next, the turbine rotation speed (Tsp) is read out, and this turbine rotation speed is compared with the first-stage downshift shift line Ld1 read above, and the turbine rotation speed is shown on the first-stage downshift shift line Ld1 in relation to the throttle opening. It is determined whether or not the turbine rotation speed is smaller than the set turbine rotation speed. When this determination is No, the control is completed as is, and when this determination is Yes, flag A is set, a command for downshifting by one stage is issued, and the control is completed. If the determination as to whether the flag A=0 is No, read the 1st gear downshift shift line Ld1, multiply this shift line Ld1 by 1.05 or 1.2, and create a new shift with hysteresis as shown by the broken line. forming a line (not shown). Next, the actual turbine rotation speed Tsp is read out, and this turbine rotation speed
It is determined whether Tsp is larger than the new shift line in relation to the throttle opening. If this determination is YES, flag A and flag B are reset to complete the control, while if this determination is NO, it is determined whether flag B is 0 or not. If this determination is YES, then it is determined whether the current gear position is the third gear. When this determination is No, the 4-2 skip shift down shift line Ld2 for performing a skip shift down from 4th gear to 2nd gear is selected and read out, while when this determination is YES, 3rd gear to 1st gear
3- for performing a skip shift down to speed
Select and read out the 1-skip downshift shift line Ld3. Next, the turbine rotation speed Tsp read out is compared with the 4-2 skip shift down shift line Ld2 or the 3-1 skip shift down shift line Ld3, and the turbine rotation speed Tsp is determined in relation to the throttle opening. Skip shift downshift line
It is determined whether or not the turbine rotation speed is smaller than the set turbine rotation speed indicated by Ld2 or Ld3. If this judgment is No, control is completed as is;
If YES, flag B is set and a command for two-stage downshift is issued. When the determination of flag B=0 is No, 4-1 skip shift down shift line Ld4 for 3-speed skip shift down from 4th gear to 1st gear
Select and read. Next, it is determined whether or not the read turbine rotation speed Tsp is smaller than the set turbine rotation speed indicated by the shift line Ld4 in relation to the throttle opening. This judgment
If the determination is No, the control is completed as is, while if the determination is YES, a command for downshifting to the first speed is issued and the control is completed. In addition, in the shift-up speed change control and shift-down speed change control explained above, when no speed change is performed, the hysteresis is created by multiplying the map's speed change line by a constant value to form a new speed change line, which is due to the turbine rotation speed. When is at the critical stage of shifting,
This is to prevent chattering caused by frequent gear changes. Upshift and downshift control has been explained above according to the control device according to the embodiment of the present invention, and now lockup control will be briefly explained. Lock-up control This lock-up control is a shift down shift line.
Using Ld as the lock-up ON/OFF control lines Le and Le', the above-mentioned lock-up is basically performed using the current turbine rotation speed Tsp in relation to the current throttle opening.
This is performed based on the ON/OFF control lines Le, Le', and a determination as to whether or not this turbine rotation speed is greater than the set turbine rotation speed indicated by the control lines. In principle, when this determination is NO, control is performed to turn lockup OFF, and when this determination is YES, control is performed to turn lockup ON. The reason why the control lines Le and Le' are set is to add hysteresis to the lock-up determination and prevent hunting. However, for example, if the current gear position is the first gear, if the warm-up state of the engine is too low to be suitable for lock-up, or if the engine is already in the lock-up state, lock-up ON control is not performed.

[Brief explanation of the drawing]

Figure 1 is a graph showing the engine speed vs. throttle opening characteristic when the engine is rotated without any load and the output shaft torque of this engine is constant at each value. FIG. 3 is a graph showing the turbine rotation speed-throttle opening characteristic when the power generated by the input and output shafts is constant at each value in the torque converter; FIG. 3 is a block diagram showing the configuration of the automatic transmission control device of the present invention; FIG. 4 is a diagram showing a cross section of a mechanical part and a hydraulic control circuit of an automatic transmission incorporating a control device according to an embodiment of the present invention, and FIG. 5 is a schematic diagram showing an electronic control circuit of the automatic transmission. 5A and 5B are diagrams showing a shift-up shift line, a shift-down shift line, and a lock-up ON/OFF control line, and FIGS. 6, 7, and 9 are flowcharts of shift control according to the present invention. , FIG. 8, and FIG. 10 are explanatory diagrams of a shift up map and a shift down map, respectively. a... Torque converter, b... Speed change gear mechanism, c... Speed change switching means, e... Electromagnetic means, f...
...Turbine rotation speed sensor, g...Engine load sensor, h...Storage means, i...Shift down discrimination means, j...Shift up discrimination means, k...Driving means, 10...Torque converter, 11...Pump , 12...Turbine, 100...Hydraulic pump,
103...Select valve, 200...Electronic control circuit, 207...Load sensor, 209...Turbine rotation speed sensor.

Claims (1)

[Claims] 1. A torque converter connected to the output shaft of the engine, a speed change gear mechanism connected to the output shaft of the torque converter, a speed change switching means for switching the power transmission path of the speed change gear mechanism to perform a speed change operation, and operating the speed change switching means. An automatic transmission includes an electromagnetic means for controlling the supply of pressure fluid to a hydraulic actuator, and the electromagnetic means is driven and controlled to perform a gear shifting operation. An engine load sensor detects the load, and each equal power characteristic curve is expressed based on the turbine rotation speed and engine load, and connects points where the engine generated power is equal for each output level. It is set to substantially correspond to the line connecting the inflection points where the rate of change changes from a state where the rate of change is large to a state where it is small, and to define a region in which the power generated by the engine increases and a region in which it does not increase as the engine load increases. The shift down shift line has a width larger than the rotational speed fluctuation range of the output shaft of the torque converter calculated according to the gear ratio difference between adjacent gears, and the rotation speed is higher than the shift down shift line. A torque converter output shaft that stores one shift-up shift line set on each side and calculates the difference in gear ratio between adjacent gears with respect to at least one of these shift lines. a storage means for storing a plurality of shift lines of the other of the shift-down shift line and the shift-up shift line set to have a width larger than the rotation speed fluctuation width of the engine; an output signal of the turbine rotation speed sensor; Upon receiving the output signals of the load sensor, these output signals are compared with one downshift shift line read out from the storage means in light of the current gear stage, and the operating state represented by the two output signals is determined. a shift-down determining means for issuing a shift-down command signal when determining that the generated power on the lower rotation side of the shift-down shift line is within an operating range in which no increase occurs; an output signal of the turbine rotation speed sensor; and an engine load sensor. 1, which receives the output signals of
Shift-up determining means that issues a shift-up command signal when it is determined that the operating state represented by the two output signals is in an operating region on the higher rotation side than the shift-up shift line in comparison with the actual shift-up shift line; and a drive means that receives a shift-down command signal from the shift-down determining means and a shift-up command signal from the shift-up determining means, and drives and controls the electromagnetic means based on these two command signals to automatically shift gears. Automatic transmission control device with