JPS59222651A - Control device in automatic transmission - Google Patents

Abstract

PURPOSE:To enhance fuel consumption, by carrying out the control of shift-down in accordance with a speed changing curve with which the torque ratio of input and output shafts of a torque converter becomes one, and as well by carrying out the control of shift-up in accordance with a speed curve based upon the rotational speed variation range of the torque converter output shaft. CONSTITUTION:Whether shift-down is necessary or not is determined by comparing output signals from a turbine rotational speed sensor (b) and an engine load sensor (g), with a shift-down speed changing curve Ld which is set and stored in accordance with a turbine rotational speed and an engine load that allow the torque ratio of input and output shafts of the torque converter (a) to become substantial one. Further, whether shift-up is necessary or not is determined by comparing the output signals from the turbine rotational speed sensor (b) and the engine load sensor (g), with a shift-up speed changing curve Lu set on the high rotational speed side higher than the shift-down speed changing curve Ld, corresponding to rotational speed variation ranges H, H' of the output shaft of a torque converter (a) which is calculated in accordance with the difference between gear ratios of adjacent speed shift stages.

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION 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 currently in common use are constructed by combining a torque converter and a multi-gear type transmission mechanism having a gear mechanism such as a planetary gear mechanism. A hydraulic mechanism is usually used for speed change control of such automatic transmissions, and 111 hydraulic paths are switched using mechanical or electromagnetic switching valves.
As a result, frictional elements such as brakes and clutches attached to the multi-gear transmission mechanism are actuated as appropriate to switch the engine power transmission system and obtain the desired gear position. When switching the hydraulic circuit using an electromagnetic switching valve, an electric device detects when the vehicle's running state exceeds a predetermined shift line, and this device
Normally, an electromagnetic switching valve is selectively operated in response to a signal, and the hydraulic circuit is thereby switched to change the speed. In conventional devices, 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 used for each gear. A transmission line is required,
This makes control complicated. In addition, since the engine load is detected by detecting the elottor opening degree, which is normally set in stages, if the above-mentioned shift line is stepped, this step-shaped shift line and the engine rotation speed - There are parts where the deviation between the torque characteristics, that is, the engine characteristics, becomes quite large. This is particularly noticeable when the quantized data used are contradictory. In order to eliminate the above-mentioned drawbacks of the conventional device, a device was proposed in Japanese Patent Publication No. 56-44312 (for example, a device using the turbine speed to engine load characteristics as the above-mentioned parameters for determining the shift line). In this way, the system that uses the turbine speed vs. engine load characteristic as a control parameter does not use data via the transmission, so there is only one shift line, and even if the throttle opening etc. change, Turbine rotation is stable with relatively little fluctuation, so there is little hysteresis between the upshift line, the downshift line, and the lock-up cut line, and there is no limit line such as a stall line, so it is easy to shift. The present invention has the advantage that there is a large degree of freedom when setting the torque converter.Object of the InventionThe present invention provides a control system for an automatic transmission of the type that uses the turbine speed-engine load characteristic as a control parameter. 10J
It is an object of the present invention to provide a control device for an automatic transmission that can set gears so that the vehicle can be operated in a low range and can improve fuel efficiency. Development of the Invention and Structure of the Invention Figure 1 shows the performance of the torque converter, with the horizontal axis representing the speed ratio between the engine speed and the turbine speed, and the edge axis representing the torque ratio of the input/output shaft of the torque converter. This is a graph. As can be seen from FIG. 1, the torque ratio has a characteristic that it decreases as the speed ratio increases. In other words, the torque converter has an automatic speed change function in which the torque increases greatly when the turbine rotation speed is slower than the pump rotation speed, and the torque increase decreases as the turbine rotation speed approaches the pump rotation speed. However, for example, in the torque converter whose performance is shown in FIG. 1, when the speed ratio becomes 0.8 or more, the torque ratio becomes 1 or less, resulting in torque loss. Therefore, as shown in FIG. 2, the present invention determines a turbine rotation speed-throttle opening characteristic curve that provides a predetermined speed ratio where the torque ratio is 1, and based on this characteristic curve. It is designed to perform speed change control. That is, as shown in FIG. 3, the present invention includes a torque converter a connected to the output shaft of an engine, and a speed change gear mechanism b connected to the output shaft of the torque converter a.
, an electromagnetic means e for controlling the supply of pressure fluid to a hydraulic actuator that operates this speed change switching means; In an automatic transmission in which the torque converter a is drive-controlled and performs gear shifting operations, the torque converter
A turbine rotation speed sensor f1 detects the output shaft rotation speed of the engine, an engine negative force sensor g detects the load of the engine, receives an output signal of the turbine rotation speed sensor f and an output signal of the engine load sensor g, and receives these output signals. , determine whether or not a downshift is required by comparing with a stored downshift shift line based on the turbine rotation speed and engine load at which the torque ratio of the input and output shafts of the torque converter a becomes substantially 1; and a downshift determining means h that issues a downshift command signal when necessary, an output signal of the turbine rotation speed sensor f, and an engine load sensor g.
, and convert these output signals into the downshift shift line corresponding to at least the rotational speed shift width of the output shaft of torque converter a, which is calculated according to the difference in gear ratio between adjacent shift gears. Whether a shift amplifier is required or not by comparing with a predetermined shift amplifier shift line selected from among a plurality of shift up shift lines set on the higher rotation side based on the current gear position. Determine,
a shift-up determining means i that issues a shift amplifier command signal when necessary; and a shift-down command signal from the shift-down determining means and the shift amplifier determining means i
The present invention is characterized in that it includes a drive means j that receives a shift amplifier command signal and controls the electromagnetic means e based on these two command signals to automatically change gears. Effects of the Invention In the automatic transmission control device of the present invention having the second configuration, 1. Downshift control is performed using a shift line set based on the turbine rotation speed-engine load characteristics where the torque ratio of the input and output shafts of the torque converter is essentially 1, so it is always operated with a torque ratio of 1 or more. Therefore, driving efficiency is improved and fuel efficiency is improved. Further, in the present invention, the shift amplifier speed change line is changed from the shift down speed change line in accordance with at least the range of rotational speed fluctuation of the output shaft of the torque converter calculated according to the difference in gear ratio between adjacent speed change legs. A plurality of lines are set on the rotation side, corresponding to the above-mentioned rotation speed fluctuation ranges, 1st speed - 2nd speed shift up shift line, 2nd speed - 3rd speed and 3rd speed - 4th speed shift amplifier. Since shift lines are set and all upshift control is performed based on these shift lines, particularly smooth shift amplifier operation can be achieved. In addition, in the operating range where the torque ratio is 1 or more, the turbine rotational speed approaches the pump rotational speed, so lock amplifier control that directly connects the pump and turbine can be performed, and from this point of view, it is even more efficient. It is possible to improve fuel efficiency. EXAMPLE 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 is composed of a torque converter 1o, 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. 1-Lux converter'-10, a pump 11 coupled to the engine output shaft 1, a turbine 12 disposed opposite the pump 11, and a stator 13 disposed between the pump 11 and the turbine 2. In other words, a converter output shaft 14 is coupled to the turbine 12 . A lock-up clutch 15 is provided between the converter output shaft load 4 and the pump 11. This lock-up clutch I5
The clutch 15 is constantly pushed in the engaging direction by the hydraulic pressure circulating within the torque comparator 10, and is held in the open state by the releasing hydraulic pressure supplied to the clutch 15 from the outside. The multi-stage float transmission mechanism 20 has a front planetary gear mechanism 21 and a rear planetary tooth + mechanism 22, and the sun gear 23 of the front planetary tooth i1j mechanism 21 and the sun gear 24 of the rear planetary gear mechanism 22 are connected by a connecting shaft 25. There is. The input shaft 26 of the multi-stage float transmission mechanism 20 is connected to the connecting shaft 25 via the front clutch 27 and to the internal gear 29 of the front planetary gear mechanism 21 via the rear clutch 28. Connecting shaft 25 or sun gear 23.2
A front brake 30 is provided between the transmission case 4 and the transmission case. 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 the planetary gear mechanism 22 of the rear planetary gear mechanism 22
A rear brake 36 and a one-way clamp 37 are provided between the planetary gear 1 rear 35 and the transmission case. The overdrive planetary gear ten liquid speed mechanism 50 includes a planetary carrier 5 that rotatably supports a planetary gear 51.
2 is connected to the output shaft 14 of the torque converter 0, and the 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 has multi-stage teeth +
It is connected to the input shaft 26 of the transmission mechanism 20. The multi-gear transmission mechanism 20 is of a conventionally known type and has three forward speeds and one reverse speed, and the required speed can be obtained by appropriately operating the crankshaft 27, 28 and the brake 30, 31. can. In the overdrive M star gear transmission 50, when the direct coupling clutch 54 is engaged and the brake 56 is not released, the shaft 1
4.26 is directly coupled, the brake 56 is engaged,
When the crutch 54 is released, it connects the shaft 14.26 in overdrive. Hydraulic Control Circuit The automatic transmission described above is equipped with a hydraulic control circuit as shown in FIG. This oil) mo control + t + 1 Raku is,
It has a mail pump 100 that is driven by the engine output shaft 1, and this oil pump

The pressure of the hydraulic oil discharged from 00 to the pressure line 10 is regulated by a pressure regulating valve 102 and guided to a select valve 103. The select valve 103 has shift positions of 1.2, ■), N, . %
Connects to C. Boat a has an actuator 1 for operating the rear clutch 28.
04, and when the valve 103 is in the above position, 1. The f&way clutch 28 is held in the engaged state. Boat a is also connected to the left side of the 1-2 shift valve llO, and its spool is pushed to the right as shown in the figure.
To the right end of the 2-3 shift valve 110 via the second line L2, to the right end of the 2-3 shift valve 12 () via the third line L3, and to the 4-man end of the 3-4 shift valve 130 via the third line L3. It is connected. The first, second and third lines L1, L
First, second, and third drain lines D1, D2, and D3 are branched from the drain lines D1, D2, and D3, respectively. 1st, 2nd, 3rd
Solenoid valves SLI, SL2, and SL3 are connected. When the solenoid valves SLI, SL2, and SL3 are energized while the line 101 and the boat a are in communication, they close the respective drain lines D1, D2, and D3, and as a result, the first, second, and third lines It is designed to increase the internal pressure. Boat b is also connected to second lock valve 105 via line 14Q, and this pressure acts to push the spool of valve 105 downward in the figure. When the spool of valve 105 is in the down position, lines 140 and 1
4 and 1 are in communication 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. Boat C is connected to second lock valve 105, and this pressure acts to push the spool of valve 1()5 upward. Additionally, boat C is connected to a 2-3 shift valve 120 via pressure line 106. In this line 106, the solenoid valve SL2 of the second drain line D2 is energized to increase the pressure in the second line L2, and this pressure moves the spool of the 2-3 shift valve 120 to the left. When,
It communicates with line 107. The line 107 is connected to the release side pressure chamber of the actuator 108 of the front brake, and when hydraulic pressure is introduced into the pressure chamber, the actuator 108
actuates the brake 30 in the release 1 deceleration direction against the pressure in the engagement side pressure chamber. The pressure in line 107 is also directed to actuator 109 of forward clutch 27, causing this clutch 27 to engage. Pressure line 10 at position ■ if select 1-interval
1, and this port d leads to line 1
12 ]-2 Silito valve 110 is reached and further line l
Actuator j1 of the rear brake 36 via l3
Connected to 4. The 1-2 shift valve llO and the 2-3 shift valve 120 are operated by the solenoid valve SLI,
When SL2 is excited/1, move the spool to switch the line,
This allows the predetermined brake 1. or the clutch operates,
1-2, 2-3 speed change operations are performed, respectively. The hydraulic control circuit also includes a cutback valve 115 that stabilizes 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 this throttle valve 116. An auxiliary throttle backup valve 117 is provided. Further, the hydraulic control circuit of this example is provided with a 3-4 shift I valve 130 and an actuator 132 in order to control the cloft 54 and brake 56 of the over-I-live planetary gear transmission 50. Actuator 132
The engagement side pressure chamber of is connected to the pressure line 101,
The brake 56 is pushed in the direction of the engagement force by the pressure in the line 101. This 3-4 shift valve also has the above 1-2.2-
Similar to the 3 shift valves 110 and 120, the solenoid valve SL3
When the spool 13 of the valve 130 is energized, the spool 13 of the valve 130 moves downward, and the pressure line 122 is shut off,
Line 122 is trained. As a result, the hydraulic pressure acting on the release side pressure chamber of the actuator 132 of the brake 56 disappears, and the brake 56 is actuated in the engaging direction, and the actuator 134 of the clutch 54 acts to release the clutch 54. Furthermore, the hydraulic control circuit of this example includes a lock-up control valve 13.
3 is provided, and this lock-up control valve 133 is communicated with the bow 1-a of the select valve 103 via a line L4. A drain line D4, which is provided with a solenoid valve SL4, branches off from this line L4, similar to the drain lines DI, D2, and D3. The lock-up control valve 133 shuts off the spool line 124 when the solenoid valve SL4 is energized, the drain line D4 is closed, and the pressure in the line L4 is full, and the line 124 is drained. The long assop clutch 15 is moved in the connecting direction. In the above configuration, the operational relationship between each gear, the lock amplifier, and each solenoid, and the operational relationship between each gear and the clutch and brake are shown in the following table. Table 1 Table 2 Electronic control circuit using 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
It includes an access memory 202 (hereinafter referred to as ΔM) and a central processing unit 203 (hereinafter referred to as CPU). Above input/output values! , 201 has engine 2
Throttle valve 20 provided in the intake passage 205 of 04
A load sensor 207 that detects the engine load from the opening degree of 6 and outputs a load signal SL, and a converter output shaft 1
Sensors for detecting running conditions such as a turbine rotation speed sensor 209 which detects the rotation speed of 4 and outputs a turbine rotation speed signal s''r are connected, and the above-mentioned signals etc. are inputted from these sensors. The input/output value W2O1 is the load signal S received from the above sensor.
L, processes the turbine rotation speed signal ST, and stores it in the RAM20.
Supply to 2. RAM 202 stores these signals SL and ST, and supplies these signals 5LSST or other data to CPU 203 in response to instructions from CPU 203. The CPU 203 reads out the turbine rotational speed signal ST according to the load f/bar number SL, for example, according to the program adapted to the speed change control of the present invention. Turbine speed as shown in figure A -
Calculate whether or not to shift based on the l-2 shift amplifier shift line Lul, 2-3 and 3-4 shifts)' Tsubu shift line Lu2, and downshift shift line Ld determined based on engine pre-meal characteristics. The above downshift shift line Ld to be performed
As described above, is determined based on the line L in FIG. 2 where the torque ratio of the input and output shafts of the torque converter 10 is 1. That is, the kickdown zone where the throttle opening is, for example, 88% or more, and the kickdown zone where the throttle opening is, for example, 1
The downshift line Ld is aligned with the line L in zones other than the extremely low load zone of 0% or less. In addition, the shift amplifier speed change lines Lu1 and Lu2 are calculated according to the difference in gear ratio between each adjacent speed change gear mechanism of the speed change gear mechanism.The rotation speed fluctuation range H of the output shaft of the torque converter
1 continuation H' (H=T n d -a, - However, T n d
- Set to a higher rotation side than the above-mentioned downshift shift line in accordance with at least the difference in the turbine rotation speed at the downshift point, the gear ratio of the GnHn speed, and the gear ratio between adjacent lower gears of the Amen speed. . Therefore, the turbine rotational speed after the shift does not change from the downshift zone to the shift amplifier zone or from the shift up zone to the downshift zone, and the shift can be performed without causing hunting caused by repeated amplifier shifts and downshifts. The above downshift line is the OF of the lock amplifier.
Lock-up OFF control line L e for performing F control
Also used as I. The calculation result of the CPU 203 is
The 1-2 shift valve 11, which is the speed change control valve described with reference to FIG.
It is given as a signal to control the excitation of the solenoid valve group 211 that operates the 0.2-3 shift valve 120, the 3-4 shift valve 130 and the lock amplifier control valve 133. This solenoid valve group 211 includes a "-2 shift valve 110.2-
3 shift valve 120, 3-4 shift valve 13o. Each solenoid valve SLI, S of the lock amplifier control valve 133
Includes L2, SL3, and SL4. An example of control of an automatic transmission by the electronic control circuit 200 will be described below. The electronic control circuit 200 is preferably configured by a microcomputer, and a program installed in the electronic control circuit 200 is executed, for example, according to the flowcharts 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. In this initialization setting, first initialize the boats and necessary counters of each control valve that switches the hydraulic control circuit of the automatic transmission, and set the one-wheel transmission mechanism 2° to series and the lock-up clutch 15 to release. . After this, various working areas of the electronic control circuit 200 are initialized to complete the initialization settings. , After this initialization setting, the select valve 103
A step of reading the position or shift range is performed. 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. Is this judgment Y? : When S, that is, shift range is 2
When in the 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 second speed. On the other hand, if the above 2-range determination is No, the shift range is Lunge, so
First, the lock-up is released, and then it is calculated whether or not the engine will overrun when shifting down to first gear. After this, after getting bored with this calculation, it is determined whether or not there will be an overrun, and if this determination is No, the first
If this determination is YES, the gear is shifted to second speed. On the other hand, if the determination as to whether the vehicle is in the D range is YES, a shift change control line and a lockup control line including a shift change control line and a lockup control line are set. Next, upshift speed change control including shift amplifier determination is performed. This shift amplifier speed change control is executed according to the shift up speed change control subroutine shown in FIG. Shift amplifier speed change control This shift up speed change control starts by first reading the gear position, that is, the position of the gear transmission mechanism 20, and then determining whether or not the gear is currently in fourth gear based on the read gear position. It will be done. This judgment is YES
In this case, since no further shift amplification can be performed, flag 1 and flag 2 are reset, that is, set to 0, and the control is terminated. This flag l and flag 2
are set when the one-stage shift amplifier and the skip shift amplifier are executed, respectively, and are used to store the state of the shift amplifier. On the other hand, if the above determination as to whether the gear is in the first gear is No, it is determined whether the flag 1 is in the reset state, that is, in the "0" state, and if this determination is YES, it is determined whether or not the gear is in the first gear. A determination will be made. If this judgment is YES, the first
Select and read out the 1-2 shift up shift line Lu1 (see Figure 8) for performing shift amplification from speed to second speed. , and 2-3.3-4 shift up transmission line Lu2 (8th gear) for performing shift amplifier from 3rd gear to 4th gear
(see figure) and read it out. Next, the turbine rotation speed (Tsp) is read, and this turbine rotation speed is applied to the first shift up shift line 1. ul or Lu2 Store the data of the shift amplifier points set on the shift amplifier shift lines Lu-1 and Lu2 in Fig. 5A (for example, C17), use the small opening θ as an address, and store the corresponding turbine rotation speed N) In light of that, the turbine rotation speed is
It is determined whether or not the rotational speed of the turbine is smaller than the set turbine rotational speed indicated by the first-stage upshift line Lu1 or Lu2 in relation to the throttle opening. When this judgment is No, 1i1JfJl is completed □, and when this judgment is YES, flag 1 is set and a command for the 1-stage shift amplifier is issued. When the determination as to whether the flag is l-0 is No, the first gear upshift shift line Lui is read out, and this shift line Lu
is multiplied by 0.8 to 0.95 to form a new shift line (not shown) with hysteresis. Next, the actual turbine rotation speed Tsp is read out, and it is determined whether or not this turbine rotation speed "I'sp" is smaller than the above-mentioned new shift line in relation to the throttle opening.
If ES, flag 1 and flag 2 are reset to complete the control, and if this judgment is No, flag 2 is reset.
Determine whether or not is 0. If this determination is YES, then a determination is made as to whether or not the current gear position is the second gear. When this determination is YES, the 2-4 gearshift shift line L1λ3 for performing a skip shift up from 2nd gear to 4th gear is selected and read out. On the other hand, when this determination is No, from 1st gear to 4th gear The 1-3 skid/1 lift-up shift line Lu4 for performing a skip shift up to 3rd speed is selected and read out. Next, the turbine rotation speed Tsp read out is set to 2 above.
-4 Skip shift up shift line Lu2 or i-3 In light of skip shift up shift line Lu3, skip shift up shift line Lu2 or It is determined whether or not the turbine rotation speed is higher than the set turbine speed indicated in Lu3. If this determination is No, the control is completed as is. On the other hand, if this determination is YES, flag 2 is set and the second-stage upshift is started. If the determination of the above flag 2-0 is No, select the 1-4 skim shift ambulation shift line L + a 5 for a 3-speed skip shift up from 1st speed to 4th speed. Next, the turbine rotation speed Ts read out above is read out.
p is the above-mentioned shift line L in relation to the opening degree
It is determined whether or not the turbine rotation speed is greater than the set turbine rotation speed indicated by u4. When this determination is No, the control is completed as is, while when this determination is YES, a command for shift amplifier to the 4th speed is issued. When the command for the shift amplifier is issued, it is then determined whether a command to shift up to fourth gear is included. When this determination is NO, the control is completed as is, while when this determination is YES, it is determined whether the engine condition is suitable for upshifting to the fourth gear. This determination is made by first reading the engine cooling water temperature, and then determining whether or not this cooling water temperature is low. If this determination is YES, the engine has not yet been sufficiently warmed up, so a command is issued to prohibit the shift amplifier to the fourth gear, and the control is completed. On the other hand, if the determination as to whether the temperature is low is No, a fourth speed flag is set indicating that the gear is shifted to fourth speed and the control is completed. With the above steps, all subroutines for shift amplifier speed change control are completed. Downshift control The downshift control is executed according to the downshift control subroutine shown in FIG. This downshift speed change control is performed by first reading out the gear position, as in the case of shift amplifier speed change control. Next, based on the read gear position, it is determined whether or not the vehicle is currently in the first gear. This judgment is YES
In this case, since no further downshift can be performed, flag A and flag B are reset, that is, to 0, and the control is terminated. This flag A and flag B
is used to store the upshift state when a one-speed downshift and a skip downshift are executed, respectively. When the determination is NO, it is determined whether the flag A is in the reset state, that is, in the "0'' state. When this determination is YES, it is determined whether the gear is in the second gear. If this judgment is YES, 1
1-stage downshift shift line Ldl in FIG. 10 (shift-down shift line L in FIG. 5A)
Describe the data of the downshift point set by d, q
(For example, the throttle opening θ is used as an address and the corresponding turbine rotation speed N is stored.). Then,
The turbine rotation speed (Tsp) was read, and this turbine rotation speed was compared with the first-stage downshift shift line Ldl read above, and the turbine rotation speed was shown on the first-stage downshift shift line Ldl in relation to the throttle opening. It is determined whether the rotation speed is smaller than the set turbine rotation speed. If this judgment is No, the control is completed, and this judgment is YES.
In this case, flag A is set, a command is issued to downshift by one stage, and the control is completed. When the determination as to whether the flag A=0 is No, the first gear downshift shift line Ldl is read out, and this shift line L d
1 is multiplied by 1.05 to 1.2 to form a new shift line (not shown) with hysteresis as shown by the broken line. Then, the actual turbine rotation speed ′r 3 I
I) is read, and it is determined whether or not this turbine rotational speed Tsp is larger than the above-mentioned new shift line in relation to the throttle opening. If this judgment is YES, flag A
and flag 1. B is reset to complete the control, and on the other hand, if this judgment is No, flag B is set to ().
Determine whether If this determination is YES, then a determination is made as to whether or not the current gear position is the third gear. This judgment is N.
0, the 4-2 skip shift down shift line Ld2 for performing a skip shift up from 4th gear to 2nd gear is selected and read out, and on the other hand, this determination is YF,
When S, the 3-1 skip shift down shift line Ld3 for performing the skip shift up from the third gear to the first gear is selected and read out. Next, the turbine rotation speed TSp is compared with the 4-2 skip shift down shift line, d2 or 3-1 skip shift down shift line Ld3, and the turbine rotation speed TSp is determined based on the throttle opening. It is determined whether or not the turbine rotation speed is smaller than the set turbine rotation speed indicated by the skimp shift down shift line Ld2 or Ld3. When this judgment is No, the control is completed as is, and when this judgment is Yes, flag B is set and a command for two-stage soft down is issued. If the determination of flag B = 0 is No, 4-1 for 7 degrees of 3-speed skimp shift from 4th gear to 1st gear.
Select and read the skip shift down shift line Ld4. Next, in relation to the throttle opening degree, the turbine rotation speed T s p read above is determined by the shift line Ld4 shown in FIG.
It is determined whether or not the turbine rotation speed is smaller than the set turbine rotation speed shown in . If this judgment is No, the control is completed as is,
On the other hand, if this determination is YES, a command to shift up to the fourth speed is issued and the control is completed. The shift amplifier and downshift shift control according to the control device according to the embodiment of the present invention have been described above.
Next, lock amplifier control will be briefly explained. Lock-up control This lock-up control is basically based on the lock-up ON/OFF control line L shown in FIG.
The determination is made based on whether or not the rotational speed of the turbine is larger than the set turbine rotational speed indicated by the control lines Le and Le', with reference to e- and Le'. In principle, when this determination is No, control is performed to turn off the lock amplifier, and when this determination is YES, control is performed to turn on lock amplifier. The above control lines Le and Le" are set in order to add hysteresis to the lock-up judgment and prevent hunting. However, for example, if the current gear position is 1st gear, the warm-up state of the engine is not suitable for lock-up. If the voltage is too low, or if the lockup condition is already present, lockup control will not be performed.

[Brief explanation of drawings]

Fig. 1 is a graph explaining the performance of the torque converter; Fig. 2 is a graph showing the turbine rotation speed-throttle opening characteristic at a predetermined gear ratio where the torque ratio of the input and output shafts is 1 in torque converter; FIG. 3 is a block diagram showing the configuration of a control device for an automatic transmission according to the present invention, and FIG. 4 is a cross section of a mechanical part of an automatic transmission incorporating a control device according to an embodiment of the present invention and hydraulic control. FIG. 5 is a schematic diagram showing the electronic control circuit of the automatic transmission; FIG. 5A is a diagram showing a shift-up shift line, a shift-down shift line, and a date-up ON/OFF control line. , FIG. 6, FIG. 7, and FIG. 9 are flowcharts 1 of shift control according to the present invention, and FIG. 8 and FIG. 10 are explanatory diagrams of a shift amplifier map and a shift down control, 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...Shift down, discrimination means, i...Shift amplifier discrimination means, j...-driving means, 10...Torque converter, 11...Pump, 12...Turbine, 10
0...Hydraulic pump, 103...Select valve, 200
...Electronic control circuit, 207...Load sensor, 209
...Turbine rotation speed sensor. Figure 1: Return ratio Figure 2: Figure 5A

Claims (1)

[Claims] 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 fluid type 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 , compare these output signals with a downshift shift line set and stored based on the turbine rotation speed and engine load at which the torque ratio of the input/output shaft of the torque converter becomes substantially 1, and determine whether a downshift is required. A shift-down determining means receives the output signal of the engine rotation speed sensor and the output signal of the engine load sensor, and transmits these output signals to each adjacent gear shift crotch. The current shift-up shift line is selected from among a plurality of shift-up shift lines set on the higher rotation side than the shift-down shift line, corresponding at least to the range of revolution speed fluctuation of the output shaft of the torque converter calculated according to the difference in gear ratios. Shift-up determining means for determining whether or not an up-shift is required by comparing the shift line with one predetermined shift amplifier shift line selected based on the gear stage of the shift-up, and issuing a shift-amp command signal if necessary; and a drive means for automatically shifting gears by receiving a shift down command signal from the shift down determining means and a shift amplifier command signal from the shift amplifier determining means and driving and controlling the electromagnetic means based on these two command signals. Automatic transmission control device with