JPS59222653A - Control device in automatic transmission - Google Patents

Abstract

PURPOSE:To make it possible to carry out the control of smooth speed change, by carrying out the control of speed change in accordance with a speed changing curve corresponding to a curve interpolating flection points of an equi-power characteristic curve, in consideration with a range of variations in the rotational speed of a torque converter output shaft, which is obtained in accordance with the difference between gear ratios of adjacent speed shift stages. CONSTITUTION:Output signals from a turbine rotational speed sensor (b) and an engine load sensor (g) are compared with a shift-up speed changing curve Lu and a shift-down speed changing curve Ld which are set based upon a turbine rotational speed v.s. engine load characteristic curve substantially corresponding to a curve P that interporates flection points of an engine output equi-power characteristic curve, and a range H of variations in rotational speed of a torque converter (a), which is calculated in accordance with the difference between gear ratios of adjacent speed shift stages. Thereby, whether shift-up or shift-down is necessary or not is determined. When judgement is made that it is necessary, a shift-up means (j) or a shift-down means (i) delivers an instruction signal to operate a drive means (k).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention 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 the hydraulic circuit is switched using a mechanical or electromagnetic switching valve, thereby controlling frictional elements such as brakes and clutches associated with the multi-gear type transmission mechanism. It is designed to operate appropriately to switch the engine power transmission system and obtain the required gear.

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
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 the conventional device, the above-mentioned shift line is determined using the vehicle speed-engine load characteristic as a control parameter, but since the vehicle speed is a control parameter via the transmission,
A different pattern of shift line is required for each gear stage, which makes control complicated. In addition, since the detection of engine speed is performed by detecting the throttle opening which is normally set in stages, if the above-mentioned shift line is made into a step shape, this step-shaped shift line and the engine 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 is coarse.

In order to eliminate the above-described drawbacks of the conventional apparatus, Japanese Patent Publication No. 56-44312 and other publications propose using the turbine speed-engine load characteristic as the parameter for determining the shift line. in this way,
Those that use the turbine rotation speed-engine load characteristic as a control parameter do not use data via the transmission, so only one shift line is required, and even if the throttle opening etc. change, the turbine rotation will not fluctuate. Relatively little (because it is stable, there is only small hysteresis between the shift amplifier shift line, shift down shift line, and lockup cut line, and there is no limit line such as a stall line, so there is more freedom when setting the shift line) It has the advantage of having a large degree.

OBJECTS 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 is capable of setting gears so as to always operate in a region with good accelerator response. The object of the present invention is to provide a control device for an automatic transmission that can improve sexual performance.

Development of the invention and structure of the invention FIG. 1 shows that when the engine is at rest, that is, when the engine is rotated without applying any load, the output shaft torque of the engine is 0.1 kg-m, 2 kg-ms 3 k ,,H
This figure shows the engine speed vs. throttle opening characteristic when the engine speed is held constant at m... As can be seen from this figure, the output shaft torque of the engine is, 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 slot noddle opening range in which the generated power does not increase.

That is, Fig. 2 shows that the power generated by the engine with the torque characteristics shown in Fig. 1 is 0.5 KW, 10 KW, 15
This is a graph showing the turbine rotation speed vs. throttle opening characteristic when constant at KW... As shown in this equal power diagram, each equal power line has an inflection point, and this inflection point At rotations lower than the power inflection line P connecting the points (the upper left zone from the power inflection line P in Figure 2), the generated power does not increase and remains constant, no matter how much the throttle opening is increased, and the accelerator Poor responsiveness. Therefore, as shown in FIG. 2, the present invention determines a power inflection line P, which is a line connecting the inflection lines of the equal power characteristic curves of the engine output, and shifts the speed based on this power inflection line (■). It is designed to perform 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 fluid type actuator for operating this speed change switching means; In an automatic transmission that performs speed change operation under drive control, a turbine rotation speed sensor f detects the output shaft rotation speed of a torque converter a, an engine load sensor g detects the engine load, and an inflection of each equal power characteristic curve of the engine output. It is set based on the turbine rotation speed-engine load characteristic that substantially corresponds to the line connecting the points, and the rotation speed fluctuation range of the output shaft of the torque converter, which is calculated according to the difference in gear ratio between adjacent transmission sections. Shift-up line and shift-down line, 1
A storage means h storing at least one continuous line each, receives an output signal of the turbine rotation speed sensor f and an output signal of the engine load sensor g, and compares these output signals from the storage means with the current gear stage. The output signal of the turbine rotation speed sensor f is used as a shift-down determination means that compares the read one shift-down shift line to determine whether or not a down-shift is required, and issues a shift-down command signal if necessary. and engine load sensor g, and compares these output signals with one shift amplifier shift line read out from the storage means in light of the current gear position to determine whether a shift amplifier is required. a shift-up determining means j that makes a determination and issues a shift-up command signal when necessary; and receiving the shift-down command signal of the shift-down determining means i and the shift-up command signal of the shift-up determining means j;
The present invention is characterized in that it includes a driving means k that automatically changes speed by driving and controlling the electromagnetic means e based on two command signals.

In the automatic transmission control device of the present invention, which has a configuration exceeding the effects of the invention, the shift line is a turbine rotation speed-engine load line that substantially corresponds to a line connecting the inflection points of each equal power characteristic curve of the engine output. Shift control is performed using a shift line set based on characteristics, so when you step on the accelerator, you can always drive in a region with good accelerator response, where the power generated increases almost in proportion to the amount of pedal depression, improving driving performance. It is possible to improve the Furthermore, in the present invention, the shift-up shift line and the shift-down shift line are determined by taking into account the range of rotational speed fluctuation of the output shaft of the torque converter, which is calculated according to the difference in gear ratio between adjacent gears. For example, a downshift shift line is determined based on the line connecting the above-mentioned inflection points, and 1st speed - 1st speed - shift down shift line is set on the high rotation side from this downshift shift line in accordance with each of the rotational speed fluctuation widths. Set the 2nd speed shift amplifier speed change line, 2nd speed - 3rd speed and 3rd speed - 4th speed shift amplifier speed change line, and perform speed change control based on these speed change lines, or set the shift amplifier speed change line and downshift speed change. The line should be at least 1 in each case, taking into account the rotation speed fluctuation range of the output shaft of the torque converter, which is calculated according to the difference in gear ratio between adjacent gear ratios.
With this setting, for example, a downshift shift line is determined based on the line connecting the above inflection points, and a shift from 1st to 2nd gear is performed to a lower rotation side than this upshift shift line in response to each of the above rotational speed fluctuation widths. A downshift line, 2nd speed - 3rd speed and 3rd speed - 4th speed downshift line are set, and the shift control is performed based on these shift lines, so that particularly smooth shift operation can be performed. I can do it. Note that in a high speed gear, for example, third speed, the upshift shift line is limited to the low rotation side by the three stray running resistance lines, so it is necessary to correct the downshift shift line accordingly.

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 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
A lock-up clutch 15 is provided between the pump 11 and the pump 11. ,,). ,7. A, 77 1, 7, i5. Yo, 1. .

The clutch converter 15 is constantly pushed in the engaging direction by the pressure of hydraulic fluid circulating in the clutch converter 10, and is held in the open state by the opening hydraulic pressure supplied to the clutch converter 15 from the outside.

The multi-stage gear transmission mechanism 20 has a front planetary gear mechanism 21 and a rear planetary gear mechanism 22, and a sun gear 23 of the front planetary gear mechanism 21 and a sun gear 24 of the rear planetary gear mechanism 22 are connected by a connecting shaft 25. Multi-stage gear transmission mechanism 20
The input shaft 26 is connected to the connecting shaft 25 via the front clutch 27.
In addition, the front planetary gear mechanism 2 is connected via the rear clutch 28.
1 internal gear 29, respectively. A front brake 30 is provided between the connecting shaft 25, that is, the sun gear 23, 24, and the transmission case. Planetary carrier 31 of the front stage planetary gear mechanism 21
and the internal gear 33 of the rear planetary gear mechanism 22.
is connected to the output shaft 34, and a rear brake 36 and a one-way clutch 37 are provided between the planetary carrier 35 of the rear planetary gear mechanism 22 and the transmission case.

The overdrive planetary gear transmission 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 10, and the sun gear 53 is connected to an internal gear 55 via a direct coupling clutch 54. Between the sun gear 53 and the transmission case, there is an overdrive bureniki 5
6 is provided, 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, and a desired speed can be obtained by appropriately operating the clutches 27, 28 and brakes 30, 31.

In the overdrive planetary gear transmission 50, when the direct coupling clutch 54 is engaged and the brake 56 is released, the shaft 14
．． 26 are connected in a direct connection, and when the brake 56 is engaged and the clutch 54 is released, the shaft 14.26 is connected 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 has an oil pump 100 driven by an engine output shaft 1, and the hydraulic oil discharged from this oil pump 100 into a pressure line 101 is reduced to a pressure by a pressure regulating valve 102 and then sent to a select valve 103. guided by. The select valve 103 is 1
, 2, D, N, R, P, and when the select valve is in the 1.2 and P positions, the pressure line 101
communicates with ports a, , b, and C of the valve 103.

Boat a has an actuator 1 for operating the rear clutch 28.
04, and when the valve 103 is in the above position, the rear clutch 28 is held engaged. PONIT A is also connected to the vicinity of the left end of the 1-2 shift valve 110 and pushes its spool to the right in the figure. The bow 1-a is further connected to the right end of the 1-2 shift valve 110 via the first line Ll 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. First, second and third drain lines D1, D2 and D3 are branched from the first, second and third lines L1, L2 and L3, respectively, and these drain lines D1, D2 and D3 are connected to is this drain line D1
, D2, D3 are connected to the first, second, and third solenoid valves SLI, SL2, and SL3. Ten solenoid valves SLI, SL2, SL3 are connected to line 101
When the drain line DI, D2, and D3 are energized while communicating with the port a, the drain lines DI, 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 valve 105 is in the lower blade position, line 140 and line 1
41 and the hydraulic pressure is introduced into the maintenance side pressure chamber of the actuator 108 of the front brake 30.
hold 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. Additionally, port 1-c is connected to a 2-3 shift valve 120 via pressure line 106. This line 106 is the second drain line D2
Solenoid valve 5L2p is energized,
When the pressure in the second line L2 is increased and this pressure moves the spool of the 2-3 shift valve 120 to the left, it communicates with the 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 operates the brake 30 in the release direction against the pressure of the engagement side pressure chamber. . Also, the pressure in line 107 is
Also guided to the actuator 109 of the front clutch 27,
This clutch 27 is engaged. The select valve 103 is
It has a port d that communicates with the pressure line 101 at the position (2), which reaches the l-2 shift valve 110 via a line 112 and is further connected via a line 113 to the actuator 114 of the rear brake 36.

When the solenoid valves SLI and SL2 are excited by a predetermined signal, the 1-2 shift valve 110 and the 2-3 shift valve 120 move the spool to switch lines, thereby operating a predetermined brake or clutch. , 1-2, 2-3 speed change operations are performed, respectively. In addition, the hydraulic pressure control circuit includes a cantback valve 115 that stabilizes the hydraulic pressure from the pressure regulating valve 102, and a pressure regulating valve 115 that stabilizes the hydraulic pressure from the pressure regulating valve 102.
A vacuum throttle valve 116 that changes the line pressure from 02, and a throttle backup valve 117 that assists this throttle valve 116 are provided. Slowly,
The hydraulic control circuit of this example includes a 3-4 shift valve 130 and an actuator 132 to control the clutch 54 and brake 56 of the overdrive planetary gear transmission 50.
is provided. The engagement side pressure chamber of the actuator 132 is connected to the pressure line 101.
The brake 56 is pushed in the engagement direction by a pressure of 1. This 3-4 shift valve also has the above 1-2.2-3 shift valve 1.
Similarly to 10.120, when the solenoid valve SL3 is energized, the spool 13 of the valve 1.30 moves downward, the pressure line 101 and the line 122 are cut 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, 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, and this lock-up control valve 133 is connected to port a of the select valve 103 via line L4. From this line L4, drain line Di
Similar to D2 and D3, a drain line D4 is provided with a solenoid valve SL4. The lock-up control valve 133 is configured such that when the solenoid valve SL4 is energized, the drain line D4 is closed, and the pressure in the line 4 increases, the spool blocks the lines 123 and 124, and the line 124 is drained. This moves the lock amplifier clutch 15 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 table below.

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 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 receives a load signal S from the sensor.
L, processes the turbine rotation speed signal ST and stores it in the RAM 202
supply to. RAM 202 stores these signals SL and S'F, and supplies these signals SL, ST or other data to CPU 203 in response to instructions from CPU 203. CP [J 2' 03
In accordance with a program compatible with the shift control of the present invention,
1-2 determined based on the turbine rotation speed-engine load characteristic as shown in FIG. 5A, for example, where the turbine rotation speed signal ST is read out in response to the load signal SL.
A calculation is made as to whether or not a shift should be made in reference to the shift-up shift line Lu1, the 2-3 shift-up shift line Lu2, and the shift-down shift line Ld. The downshift line Ld is determined based on the line P in FIG. 2, which connects the inflection points of the equal power characteristic curves of the engine output shaft, as described above. In other words, as mentioned above, the shift 1-up gear shift is restricted by the 3 stray running resistance line A, except for the zone above the throttle opening of about 60% and the zone of throttle opening lθ% 12T with extremely low negative fit. The line P and down/shift line Ld are made to coincide with each other at the position. In addition, the shift 1 up speed change coefficients Lu1 and Lu2 are the turbine rotational speed at the turn point calculated according to the difference in gear ratio between each adjacent speed change gear mechanism of the speed change gear mechanism,
G n ; The gear ratio of the n-speed is set at a higher rotation side than the above-mentioned downshift shift line in accordance with at least the difference in gear ratio between the Amen speed and the adjacent lower gear.

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 causing hunting caused by repeated upshifts and downshifts.

The shift map shown in FIG. 5A was equipped with a 1-2 shift amplifier shift line Lu1, a 2-3 and 3-4 shift up shift line Lu2, and a shift down shift line Ld. The map used in FIG. 5B may include a 2-1 downshift shift line Ldl instead of the 1, + 1-2 shift amplifier shift line Lul. This 2-1 downshift shift line Ldl is set to a lower rotation side than the 2-3 and 3-4 shift amplifier shift lines Lu2 by the rotation speed fluctuation width H'.

The calculation result of the CPU 203 is transmitted via the input/output bag W2O1 and the drive circuit 211 to the 1-2 shift valve 110, which is the speed change control valve described with reference to FIG. 4, and the 2-3 shift valve 12.
It is given as a signal to control the excitation of the solenoid valve group 211 that operates the 0, 3-4 shift valve 130 and the lock-up control valve 133. This solenoid valve group 211 includes ■
-2 shift valve 110.2-3 shift valve 120.3-4 shift valve 130, lock-up control valve 133 each solenoid valve SL1. ．． Includes SL2, 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 constituted by a microcomputer, and a program installed in the electronic control circuit 200 is executed, for example, according to the flowcharts shown in FIGS. 6 and subsequent figures.

Figure 6 shows an overall flowchart of shift control, and as can be seen from this figure, shift control is first performed from initialization settings. In this initialization setting, first, the boats and necessary counters of each control valve that switches the hydraulic control circuit of the automatic transmission are initialized, and the gear transmission mechanism 20 is set to first speed 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, 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. 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, the judgment of the above 2 ranges is N.
When the shift range is set to lunge, it is calculated whether or not the engine will overrun when the lock-up is first released and the gear is then downshifted to the first gear.

Thereafter, based on this calculation, it is determined whether or not an overrun will occur, and if this determination is NO, the gear is shifted to the first gear, and if this determination is YES, the gear is shifted to the second gear.

On the other hand, if 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 amplifier speed change control including a shift-up determination is performed. This shift-up speed change control is executed according to the shift amplifier speed change control subroutine shown in FIG. Note that in this embodiment, the multi-stage gear transmission 200
Shifting to the reverse, neutral, or parking state is executed by switching the hydraulic circuit by operating the select valve 103.

Shift-up speed change control This shift amplifier speed change control first reads the gear position, that is, the position of the gear transmission mechanism 20, and based on the read gear position, determines whether or not it is currently in the fourth gear. You can start from This judgment is YES
In this case, since no further upshift can be performed, flag 1 and flag 2 are reset, that is, set to 0, and the control is terminated. This flag 1 and flag 2
are set when the one-stage shift amplifier and skip shift amplifier are executed, respectively, and are used to store the shift amplifier status.

On the other hand, if the above determination as to whether the vehicle is in the first gear is NO, it is determined whether the flag l is in a reset state, that is, in the "0" state, and if this determination is YES, it is determined whether the flag is in the first gear or not. A determination is made. If this judgment is YES, the first
Select and read out the 1-2 shift door/knob shift line Lu1 (see Figure 8) for performing the shift amplifier from 2nd speed to 2nd speed.On the other hand, if this judgment is NO, shift from 2nd speed to 3rd speed. , °′ Yoyo-th, speed 1. 4th gear x (
D.7. A. Select and read out the 2-3.3-4 shift amplifier speed change line Lu2 (see FIG. 8) for performing step 7. Next, the turbine rotation speed (TSp) is read out, and this turbine rotation speed is applied to the first-stage shift up transmission line Lul or Lu2 which is read out above.
In light of the stored data of the shift up points set for ul and Lu2 (for example, the throttle/nottle opening degree θ is used as an address and the corresponding turbine rotation speed N is stored),
The turbine rotation speed is 1 in relation to the throttle opening.
It is determined whether or not the turbine rotation speed is smaller than the set turbine rotation speed indicated by the stage shift amplifier transmission line Lu1 or Lu2. If this judgment is No, the control is completed and this judgment is Y.
When it is ES, flag 1 is set and a command to shift up by one gear is issued.

When the determination as to whether the flag 1=0 is NO, the above-mentioned 1st gear upshift shift line Lul is read out, and this shift line Lul is
is multiplied by 0.8 to 0.95 to form a new shift line (not shown) with hysteresis. Next, the actual turbine rotation speed 1'sp 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/nottle opening degree. This judgment is Y
When ES is determined, control is completed by resetting flag l and flag 2. On the other hand, when this determination is NO, flag 2 is reset.
Determine whether or not is O. 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, select and read the 2-4 skip shift up transmission line Lu3 for performing skip shift amplifier from 2nd speed to 4th speed;
On the other hand, if this determination is No, the 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 rotational speed T sp read out above is applied to the 2-4 skip shift up shift line Lu2 or 1-
3. In light of the skip shift up transmission line Lu3, determine whether the turbine rotation speed 1"sp is larger than the set turbine rotation speed indicated on the skip shift up transmission line Lu2 or Lu3 in relation to the throttle opening. do.

When this determination is No, the control is completed as is, while when this determination is YES, flag 2 is set and a command for two-stage upshift is issued.

When the determination as to whether the flag 2=0 is NO, the 1-4 skip shift up shift line Lu5 for the 3-speed skip shift up from the 1st speed to the 4th speed is selected and read out.

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 Lu4 in relation to the throttle opening. When this determination is No, the control is completed as is, while when this determination is YES, a command to shift up to the 4th speed is issued.

When the command for the shift amplifier is issued, it is then determined whether a command for the shift amplifier to the fourth speed is included. If this determination is NO, the control is completed as is, while if this determination is YES, it is determined whether the engine condition is suitable for shifting up 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 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 amplifier speed change control are completed.

Downshift control The downshift control is executed according to the downshift control subroutine shown in FIG. This downshift control is performed by first reading out the gear position, as in the case of upshift control.

Next, based on the read gear position, it is determined whether or not the vehicle is currently in the first gear. If this determination is YES, it means that no further downshifts can be performed, so flag A and flag B are reset, that is, set to 0, and the control is terminated.
Flag B and flag B are set to 71, that is, "1", when the shift amplifier is shifted down by one stage and when the shift amplifier is skipped, respectively, and is 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 A 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 second gear. A determination is made. When this determination is YES, the data of the shift down point set by the 1st gear downshift line Ldi in Figure 1O (the downshift line Ld in Figure 5A) to perform the 1st gear downshift is stored ( For example, the throttle opening degree θ is used as an address, and the corresponding turbine rotation 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 shift down shift line Ldl read above to determine whether the turbine rotation speed is in relation to the throttle opening.
9. It is determined whether or not the turbine rotation speed is smaller than the set turbine rotation speed indicated by the downshift line Ldl. 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.

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 Ldl is read out.
is multiplied by 1.05 to 1.2 to form a new shift line (not shown) with hysteresis as shown by the broken line. Next, the actual turbine rotational speed 'l''sp is read out, and it is determined whether or not this turbine rotational speed T''sp is larger than the above-mentioned new shift line in relation to the throttle opening. When this judgment is YES, flag A and flag B are reset and control is completed, while this judgment is N.
If o, it is determined whether flag B is 0.

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 No
When , the 4-2 skip shift down shift line L for performing skip shift amplifier from 4th gear to 2nd gear
d2 is selected and read out. On the other hand, when this determination is YES, a 3-1 skip shift down shift line Ld3 for carrying out a skip shift amplifier from the third speed to the first speed is selected and read out.

Next, the above-mentioned read turbine rotation speed T s p is applied to the above-mentioned 4-2 skimp shift down shift line L'd2 or 3.
-1 With reference to the skip shift down shift line Ld3, it is determined whether the turbine rotation speed Tsp is smaller than the set turbine rotation speed indicated by the skip shift down shift line Ld2 or Ld3 in relation to the throttle opening.

When this determination is No, the control is completed as is, while when this determination is YES, flag B is set and a command for two-stage downshift is issued.

When the determination as to whether the flag B=0 is NO, the 4-1 skip shift down shift line Ld4 for the 3-stage skip shift amplifier from 4th speed to 1st speed is selected and read out.

Next, it is determined whether or not the read turbine rotation speed T'sp is smaller than the set turbine rotation speed indicated by the shift line Ld4 in relation to the throttle opening.

When this determination is No, the control is completed as it is, while when this determination is YES, a command is issued to shift up to the 4th speed and the control is completed.

In addition, in the shift-up speed change control and shift-down speed change control explained above, when a speed change is not performed,
The reason for creating hysteresis by multiplying the map's shift line by a certain value to form a new shift line is to prevent chuck ring from occurring due to frequent gear changes when the turbine rotational speed is at the critical speed. This is to prevent this.

The upshift and downshift control according to the control device according to the embodiment of the present invention has been described above, and now the lockup control will be briefly described.

Lock-up control This lock-up control connects the downshift shift line Ld to the lock amplifier 0N-OFF control line L e s, I
Basically, the current turbine rotation speed TPS is compared with the lock-up ON/OFF control line LesLe' in relation to the current throttle opening, and this turbine rotation speed is set as shown in the control line. This is performed based on a determination as to whether or not the rotation speed is greater than the turbine rotation speed. In principle, when this determination is ON, lock-up OFF control is performed, and when YES, lock-up No. control is performed. Note that the control line LesLe
The purpose of setting ′ is to add hysteresis to the lockup judgment 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 control is not performed.

[Brief explanation of the drawing]

Figure 1 is a graph showing the engine speed vs. throttle opening characteristic when the output shaft torque of this engine is constant at each value when the engine is rotated without applying a load. The figure 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. 3rd rA shows the composition of the control device of the automatic transmission of the present invention. A block diagram; 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; FIG. 5 is a diagram showing an electronic control circuit of the automatic transmission. Schematic diagrams, FIGS. 5A and 5B are diagrams showing a shift-up shift line, a shift-down shift line, and a lock-up ON/OFF control line; FIGS. 6, 7, and 9 are diagrams showing the shift control according to the present invention. 8 and 10 are explanatory diagrams of the shift up map and the shift down map, respectively. a... Torque converter, b... Speed change gear mechanism, C
・・・Speed changeover means, e...Electromagnetic means, ``...Turbine rotation speed sensor, g...Engine 9 sensor, h...
...Shift down discrimination means, i...Shift up discrimination means, j...Driving means, 10...Torque converter, 11...Pump, 12...Turbine, 100...
Hydraulic pump, 103...Select valve, 200...Electronic control circuit, 207...9 Load sensor, 209...Turbine rotation speed sensor. Patent applicant: Toyo Kogyo Co., Ltd. Figure 6 Turbine

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 The shift-up shift line and storage means storing at least one shift-on-down shift line, receiving an output signal from the turbine rotation speed sensor and an output signal from the engine load sensor;
These output signals are compared with the one downshift shift line read out from the above-mentioned means ↑ in light of the current gear position, it is determined whether or not a downshift is required, and the shift is performed if necessary. a shift-down determining means for issuing a down command signal, a signal receiving the output signal of the engine rotation speed sensor and the output signal of the engine load sensor, and reading out these output signals from the storage means in light of the current gear position; a shift-up determination means for determining whether or not a shift-up is required by comparing the shift-up shift line with a shift-up shift line, and issuing a shift amplifier command signal if necessary; and a shift-down command signal of the shift-down determination means and the shift-up A control device for an automatic transmission comprising a drive means that receives a shift-up command signal from an amplifier determination means and drives and controls the electromagnetic means based on these two command signals to automatically change gears.