JPS59219568A - Lock-up controller of automatic transmission - Google Patents

Abstract

PURPOSE:To improve the effect of engine brake, by a method wherein a lock-up control line, which, based on the number of revolutions of a turbine in a condition, wherein the output of an engine can be considered to be zero, and an engine load, is set only in a region in which the number of revolutions of the turbine is decreased to below a given value. CONSTITUTION:A lock-up means (d) is disengaged by controlling an electromagnetic means (e) through a control means (j) by means of the output of a lock-up deciding means (i). The deciding means (i) stores a first control line h1 in a condition in which a ratio of the output torque of an engine (a) to the output torque of a torque converter can be considered to be 1, a second control line h2 in a condition in which the output of an engine can be considered to be zero, and a third control line h3 serving as a boundary line in which operation of the lock- up means (d) is allowable. The second control line h2 is set only in a region in which the number of revolutions of a turbine is decreased to below a given value, and on and from a point, where the number of revolutions attains a given value, the line extends to a point where the opening of a throttle valve is brought to zero as the given value remains unchanged.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for an automatic transmission, and more particularly to a control device for a lock-up mechanism that directly connects the input and output shafts of a torque converter.

(Prior Art) A torque converter usually includes a pump impeller, a turbine runner, and a stator disposed between them, and circulates hydraulic oil from the pump impeller driven by an engine, and circulates hydraulic oil from the turbine runner. Using the stator at an appropriate angle, the oil is smoothly introduced from a direction that does not interfere with the rotation of the pump impeller, and by repeating this operation without reducing the speed of the circulating hydraulic oil, the reaction force of the turbine runner can be reduced. In a torque converter, when the rotational speed of the turbine is slower than the rotational speed of the pump, the increase in torque is large, and when the rotational speed of the turbine approaches the rotational speed of the pump (
However, it has the drawback that the power transmission efficiency decreases due to slip between the pump and the turbine, resulting in poor fuel efficiency. In order to eliminate this slip (and reduce the power transmission efficiency) and improve fuel efficiency, recently, a direct coupling mechanism or lock-up mechanism that directly connects the input shaft and output shaft of the torque converter, that is, a direct coupling clutch or lock, has been developed. It has been proposed to provide a lock-up clutch and perform lock-up control in which the pump and turbine are directly connected by the lock-up clutch under operating conditions in which the turbine rotation speed approaches the pump rotation speed.

This lock-up control is, for example,
As described in Publication No. 59, a rotation speed sensor detects the rotation speed of the output shaft of the engine or a shaft driven by the engine, and detects the rotation speed signal and the negative pressure in the intake pipe. The load signal from the load sensor that detects
``When the relationship between the rotation speed signal and the load signal, that is, the coordinates determined by the two signals, is in a lock-up operation zone on the higher rotation side than the lock-up control line, the lock-up mechanism is activated to perform lock-up, On the other hand, when the coordinates are in a lockup release zone on the lower rotation side than the lockup control line, the operation of the lockup mechanism is stopped and lockup is released.

In the lock-up control described in the above-mentioned patent publication, the activation and release of the lock-up mechanism of the torque converter can be automatically controlled under desirable conditions according to the operating state of the engine, and it is possible to improve fuel efficiency. can. However, in this lock-up control, even when the throttle is fully closed, the relationship between the rotation speed signal and the load signal, that is, the coordinates determined by these two signals, is
When the lock-up control line is in the lock-up activation zone on the high rotation side, the lock-up mechanism operates and the input shaft and output shaft of the torque converter are locked up. However, when the throttle is fully closed, the engine output is unstable, so the lock-up mechanism is activated. If it is operating, vibration may occur.

Therefore, for example, in JP-A No. 56-39353,
A lock-up control method A1 has been proposed in which lock-up is released when the throttle is fully closed or in the vicinity thereof, regardless of the relationship between the engine speed and the engine load and the lock-up control line.

However, this lock-up control method in which the lock-up is simply released when the throttle is fully closed or in the vicinity thereof has the following three drawbacks.

First disadvantage The first drawback is that it is disadvantageous in terms of fuel consumption.

Figure 1 shows that the output shaft torque of the engine is 0.0 when the engine is rotated without applying any load. 2. 3. This shows the engine speed vs. throttle opening characteristic when the engine speed is constant at 4 to 14.5 kg/m.As can be seen from Figure 1, the engine speed when the engine's output shaft torque is zero. -The throttle opening characteristic is shown by a line rising to the right, and as the throttle opening increases, the engine speed also increases.

Next, Figure 2 shows a throttle opening of 10 degrees.

20 degrees, 30 degrees, 40 degrees, 501 units - 60 #, full) Engine speed-output torque characteristics (dashed line) when open and constant, and fuel consumption rate 2 degrees 4.6, 8, 10,
This figure shows the engine rotation speed-output torque characteristic (solid line) when it is kept constant at 121/1-1. As can be seen from the engine speed vs. output torque characteristic shown by the solid line in Fig. 2, f(, for the same output torque, the lower the engine speed, the better the fuel efficiency. The rotational speed-fuel flow rate characteristic is particularly shown in FIG. 2A.

Next, in Fig. 3, a torque converter is connected to the engine output shaft, and the throttle opening is set to 0/8 (fully closed) and 1/
8. 3/8. Turbine speed vs. engine speed characteristics (dashed line) when kept constant at 8/8 (fully open), and throttle opening at O/8 (fully closed), 1/8.2/8°3
/8.4/8.5'/8.6/8.7/8° Turbine rotation speed vs. turbine output shaft torque characteristics (solid line) when held constant at 8/8 (fully open). Next, Fig. 4 shows that the turbine output shaft torque is 0.2,3.
・・・・・・・It shows the turbine rotation speed - throttle opening characteristic when constant at 1.8 kg・m.As can be seen from this figure 4, this turbine rotation speed - throttle opening characteristic The characteristics are almost the same as the engine speed-throttle opening characteristics shown in FIG. 1 above.

Based on the characteristics of the engine and torque converter as explained above, as shown in Figure 5, the horizontal axis shows the turbine and engine speed (rpm) ft, and the vertical axis shows the throttle opening. On the coordinates, draw lines ■ and O that indicate the turbine speed-throttle opening characteristic when the turbine output torque is zero (and also draw the engine speed-throttle opening characteristic when the turbine speed is 200 rpm and 4000 rpm). Showing line T, 2
000 and I, 4000 respectively. In this figure, the engine speed-throttle opening characteristic when the turbine speed is 200 rpm will be analyzed with reference to line L2ooo. In this way, increase the turbine speed to 200
If the throttle opening is 0% to 100% as orpm, the engine speed is approximately 1.70Orpm to 270
Orpm, and when the throttle opening is about 8%, or about 7 degrees and 2 minutes, it reaches 200 Orpm, which is the same as the turbine rotation speed.
pm, and if the throttle opening is greater than that, the rotational speed will exceed the turbine rotational speed, and if the throttle opening is less than that, the rotational speed will be less than the turbine rotational speed. That is, the engine speed has a characteristic that it increases or decreases relative to the turbine speed, with the boundary at the point where the torque generated by the output shaft of the turbine becomes zero.

Considering the lock-up control characteristics of the lock-up control device for an automatic transmission described in the above-mentioned Japanese Patent Application Laid-Open No. 56-39353 under the characteristics of the engine and torque converter as described above, it is found that in this conventional lock-up control device, As mentioned above, the lock-up is released only when the throttle opening becomes zero, so the line I, which shows the turbine rotation speed-throttle opening characteristic when the output shaft torque of the turbine is zero, is o (see Figure 5), for example, when the turbine rotation speed is 200 rpm, the lock-up mechanism is activated even when the throttle opening is approximately 8% to 0% as described above. Although the engine speed must actually be lower than the turbine speed, the engine speed is raised to the turbine speed due to the lock-up operation. As can be seen from Figure 2A, the engine speed is raised to the turbine speed in this way.
This results in more fuel being consumed than necessary, which goes against the purpose of using the lock-up mechanism to improve fuel efficiency.

Second Disadvantage The second disadvantage is that a considerable torque shock occurs when lock-up is released when the throttle opening becomes zero.

This is because in the conventional lock-up control device mentioned above,
As described above, even when the throttle opening degree decreases beyond the line LO shown in FIG. 5, the lock-up mechanism continues to be maintained in the operating state, so in this case, the engine is rather rotated by the turbine. Kneading is a state in which the engine is generating negative output torque, so to speak.
In other words, it can be said that the load of the engine is being applied to the turbine. In this conventional lock-up control mechanism, lock-up is released only when the throttle opening further decreases to zero, so the turbine is subjected to severe load fluctuations at this time and a large torque shock occurs. .

Third Disadvantage The third disadvantage is that when driving a car on a slope, the engine braking force does not correspond to the accelerator opening, that is, the throttle opening.
This means that a sudden turning point in the engine braking force occurs.

FIG. 6 is a graph showing how the driving force changes when the accelerator opening degree is gradually lowered in the conventional device. When the accelerator opening degree decreases with the driving force being zero, if the lock amplifier mechanism is not operating, the driving force changes as shown by the broken line. However, when the lock-up mechanism is in operation, the driving force is forcibly lowered as shown by the solid line, so that it is less than 1 driving force when the lock-up is not in operation, as shown by the broken line. Under such circumstances,
When the accelerator opening is fully closed and the lock-up is released, the driving force is rapidly increased to the driving force when the lock-up is not activated, as shown by the broken line, and a shock occurs at this time.

On the other hand, when the accelerator is gradually opened from a fully closed position, the process is almost reverse to that described above, and therefore, the driving force decreases rapidly at the start of the lock-up operation, causing a shock.

In view of the three drawbacks mentioned above, a proposal has been made to release the lockup at the zero line of the engine output, instead of releasing the lockup when the throttle opening reaches zero. Shown in Figure 6A-
j45 is the relationship between the engine throttle opening degree and the turbine rotation speed of the torque converter [Oi (, the 10th pull-up control line h1 indicating the point where the ratio of the input/output torque of the torque converter (l/ru ratio) is 1; The lock-up area (Fig. A proposal has been made to improve the above-mentioned three drawbacks by activating the lock-up in the shaded region in the middle. In this range, the output torque of the torque converter becomes smaller than the engine output torque, and the torque amplification effect disappears, so the function as a torque converter becomes unnecessary.For this reason, on the right side of the 10th pull-up control line ht, the lock-up is activated to directly transmit engine output to the transmission, thereby eliminating power loss caused by the torque converter and improving fuel efficiency. is h2
In a smaller range, as shown in the first drawback above, if the lockup is left in operation, the engine rotational power will be pulled up by the turbine rotation and fuel consumption will increase, so in this range, the lockup can be released to improve fuel efficiency. On the other hand, the 30th pull-up control line h3 releases the lock-up when the turbine speed falls below a predetermined value, and even if the turbine speed decreases due to the action of the torque converter, the engine speed remains above the predetermined value. It is set to keep the engine/stator at tl-8.

On the other hand, when a vehicle is equipped with an automatic transmission that uses a torque converter, the lockup does not operate and power is transmitted only by the torque converter (i.e., the 6th A
Due to the characteristics of the torque converter, the effectiveness of the engine brake may be insufficient when descending or decelerating. %, it may be strongly desired that engine braking force be applied at high speeds.

(Object of the Invention) In view of the above requirements, the present invention operates a lock-up clutch to ensure that engine braking is applied when exiting or decelerating at high speed, thereby increasing the engine braking force at high speed. It is an object of the present invention to provide a lock-up control device for an automatic transmission that prioritizes transmission.

(Structure of the Invention) As shown in FIG. 7, the lock-up control device for an automatic transmission of the present invention includes a torque converter b connected to the output shaft of an engine a, and a torque converter b connected to the output shaft of the torque converter b. transmission gear mechanism C1 said torque converter b
lock-up means d for connecting and disconnecting the input shaft and output shaft of the converter to switch the power transmission path; electromagnetic means e for controlling the supply of pressure fluid to the lock-up means d for operation of the lock-up means d; and the torque converter b. Turbine rotation speed sensor f1 that detects the number of output shaft rotations of engine a; Engine load sensor g1 that detects the magnitude of the load on the engine a;
The output signal of the turbine rotation speed sensor and the output signal of the engine load sensor are input, and these two output signals are connected to the preset and stored lockup control lines old and h.
2 and 113, lockup on/off
Lockup judgment means that generates an OFF signal! , and a control means J for receiving the lockup on/off signal and driving and controlling the electromagnetic means based on the on/off signal to control activation/release of the lockup means d, and a lockup determination means I cover. , the ratio of the output torque of engine a to the output torque of torque converter b can be considered to be 1, and the tenth pull-up control line h1, which is preset based on the turbine rotation speed and engine load of torque converter b, and the engine output. i or the 20th pull-up control line hz (for example, the 4th
(Use the line of the turbine rotation speed-throttle opening characteristic when the generated torque is zero shown in the figure) and the lower limit of the turbine rotation speed as the allowable boundary line for the operation of the lock-up means d. A plurality of 30th pickup control lines h3 preset for each gear stage are stored, and the 20th pickup control line h2 is set in a region where the turbine rotation speed is below a predetermined value, and when the turbine rotation speed reaches the predetermined value. The line extends downward in the figure from the point where the turbine rotation speed remains at a predetermined value to the point where the throttle opening becomes zero, and the 20th pull-up control line is not provided in the region where the turbine rotation speed exceeds the predetermined value. It is something to do.

(Effects of the Invention) In the lock-up control device for an automatic transmission according to the present invention configured as described above, the turbine rotational speed remains at a predetermined value even if the throttle opening is lower than the level at which the engine output can be considered as zero. When it exceeds the lockup will be activated,
For example, when the vehicle speed exceeds a predetermined speed when exiting the vehicle, or when the vehicle speed exceeds a predetermined speed and the accelerator pedal is released to decelerate, the engine brake can be applied sufficiently, and the engine braking force is relatively small. When the vehicle speed is below a predetermined value, the lock-up is activated and released in a state where the engine output can be considered to be zero, thereby improving fuel efficiency and reducing shock during lock-up.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 8 is a diagram showing a cross section of a mechanical part and a hydraulic control circuit of an electronically controlled automatic transmission incorporating a lockup control device according to an embodiment of the present invention.

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.

The torque converter 1o includes a pump 11 coupled to an engine output shaft 1vc, a turbine 12 disposed opposite the pump 11, and a stator 13 disposed between the pump 11 and the turbine 12. is connected to the converter output shaft 14. Converter output shaft 1
4 and the pump 11 is a lock-up clutch 15.
is provided. This lock-up clutch 15 is
The clutch 15 is constantly pushed in the engagement direction by hydraulic oil pressure circulating within the l/lux converter 10, and is held in the released state by the release hydraulic pressure supplied to the clutch 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 3o is provided between the connecting shaft 25, that is, the sun gears 23 and 24, and the transmission case. Planetary carrier 31 of the front stage planetary gear mechanism 21
The internal gear 33 of the rear planetary gear mechanism 22 is connected to an 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. An overdrive brake 5 is provided between the sun gear 53 and the transmission case.
6 is provided, and the internal gear 55 is connected to the multi-stage gear transmission mechanism 200A power shaft 26.

The multi-gear transmission mechanism 20 is of a conventionally known type and has 3 forward speeds and 71 forward speeds, and the desired speed can be obtained by operating the clutches 27, 28 and brakes 30, 31'& as appropriate. can. In the overdrive planetary gear transmission 50, a direct coupling clutch 54 is engaged and a brake 56 is engaged.
When the shafts 14, 26' are released, the shafts 14, 26' are connected in a direct connection, the brake 56 is engaged, and when the clutch 54 is released, the shafts 14, 26' are connected in an overdrive state.

The automatic transmission described above is equipped with a hydraulic control circuit as shown in FIG. This hydraulic control circuit has 100 oil pumps driven by the engine output shaft 1, and a pressure line 10.11C from the oil pump 100.
The pressure of the discharged hydraulic oil is adjusted by the pressure regulating valve 102 and guided to the select valve 1.03K.

The select valve 103 has 1, 2 . D.N.R.

P shift positions, and the select valve has 1°2 and P shift positions.
When in position, pressure line 101 communicates with ports a, b, and c of valve 103.

Bow) a is connected to the actuator 104 for operating the rear clutch 28, and when the valve 103 is in the above-mentioned position, the rear clutch 28 is held in the stopped state. Port a is also connected near the left end of the 1-2 shift I valve 110, pushing its spool to the right in the figure. Baud) a further connects 1-2 via the first line L11.
It is connected to the right end of the shift valve 110, to the right end of the 2-3 shift valve 120 via the second line T and 2q, and to the right end of the 3-4 shift valve 130 via the third line L3i. There is. The first, second and third lines Ll.

From L2 and L3 respectively first, second and third drain lines D1. D2 and D3 are branched,
These drain lines DI.

D2. D3 has this drain line DI, D2゜D
1st, 2nd, and 3rd solenoid valves SLI that open and close 3
, SL2. SL3 is connected. The above solenoid valve S L 1. S L 2. SL3 is line 101
When the drain line DI is energized while the port A is in communication with the drain line DI.

D2. D3 is 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 down position, lines 140 and 1
41 and hydraulic pressure is introduced into the engagement 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, this pressure acts to push the spool of the branch piece 105 upward. Further, the pressure line 106 is connected to a 2-3 shift valve 120 via a pressure line 106. This line 106 is the second drain line D2
The solenoid valve SL2 is energized to increase the pressure in the second line L2, and this pressure causes the 2-3 shift valve 12 to be activated.
When spool 0 is moved to the left, line 10
7r is connected. 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 moves the brake 30 in the release direction against the pressure of the engagement side pressure chamber. Activate. Also, the pressure in line 107 is
This clutch 27 is also guided to the actuator 109 of
engage.

The select valve 103 is connected to the pressure line 101 in one position.
and has a port d leading to line 11
2 to reach the 1-2 shift valve 110, and further line 11
3 to the actuator 114 of the rear brake 36. The 1-2 shift valve 110 and the 2-3 shift valve 120 operate solenoid valves SLI and SL in response to a predetermined signal.
When 2 is energized, the spooler is moved to switch the line, thereby operating a predetermined brake or clutch and performing a 1-"-2 and 2-3 speed change operation. Also, the hydraulic control circuit has a A cutback valve 115 that stabilizes the oil 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 intake negative pressure, and a throttle backup valve 117 that assists this throttle valve 116. is provided.

Further, the hydraulic control circuit of this example is provided with 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. The engagement side pressure chamber of the actuator 132 is connected to the pressure line 101, and the pressure of the line 101 pushes the brake 56 in the engagement direction. This 3-4 shift valve is similar to the 1-2.2-3 shift valve 110120 described above, when the solenoid valve S L 3 is energized, the spool 131 of the branch piece 130 moves downward, and the pressure line 101 and line 122 are When shut off, 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 is provided, and this lock-up control valve 133 is communicated with port a of the select valve 103 via line L4y. This line L4 is the drain line DI.

D2. Similar to D3, a drain line D4 is provided with a solenoid valve SL4 and branches off.

The lock-up control valve 133 is a solenoid valve S L 4
is excited, drain line D4 is closed, and line L
When the pressure inside 4 increases, the spool moves to line 1.
23 and the line 124, and the line 124 is further drained, thereby moving the lock-up clutch 15 in the connecting direction.

In the above configuration, the operational relationship between each gear stage, lock amplifier, and each solenoid, and the operational relationship between each gear stage, clutch, and brake are shown in the following table.

Table 1 Table 2 - 31 - Electronic Control Circuit Next, with reference to FIG. 9, an electronic control circuit 200 for controlling the operation of the hydraulic control circuit described in "2" will be described.

The electronic control circuit 200 includes a shift solenoid 206 consisting of solenoid valves SLI, ST-, 2, and SL3 of the 1-2 shift valve 110, 2-3 shift valve 120, 3-4 shift valve 130 in the hydraulic control circuit. A speed change control circuit 201. and lock-up solenoid S L
4'& lock-up control circuit 202 for control
It is equipped with The shift control circuit 201 and lock-up control circuit 202 include a throttle opening sensor 204 that detects the engine load from the opening of a throttle valve 206 provided in the intake passage of the engine, and a throttle opening sensor 204 that detects the rotation speed of the torque converter output shaft. Turbine rotation speed sensor 20
3, and a gear position sensor 205 that detects the state of the gear position.
are connected to each other, and each detection signal is inputted from these sensors. The electronic control circuit 200 converts the signals from each sensor into a shift-up shift line Lu, a shift-down shift line Ld, and a shift-down shift line Ld, which are determined based on the turbine speed-engine load characteristics as shown in FIG. 9A, for example. Lockup control line h+, h2゜11
3. Judgment on gear shifting and lock-up is made based on the following criteria:
Depending on this determination, the shift solenoid 206 and the lock-up solenoid 207 are controlled. Note that the 10th pickup control line h1 is based on the position where the input/output torque ratio of the torque converter is approximately 1, and the 20th pickup control line h2 is based on the position when the turbine rotation speed is below a predetermined value (in this example, approximately 250OR, PM). (at the following times) is based on the line where the engine's output torque is zero, and when the turbine rotation speed is a predetermined value, it is based on the line that descends vertically from the point where the engine's output torque is zero until the throttle opening becomes zero. I'm trying to set it up. Therefore, the 20th pickup control line 1]2 does not exist in a region where the turbine rotational speed exceeds a predetermined value. In this case, the predetermined value of the turbine rotation speed (approximately 250 OR, PM in this example) is set to be larger than the lower limit value (approximately 1800 RPM) of the shift-up control line Lu, and when the throttle opening is near fully closed, When the turbine rotational speed exceeds a predetermined value, it is preferable that an upshift is performed to reach the fourth speed, which is the highest speed. By doing this, lock-up occurs only in 4th gear when the throttle opening is close to fully closed, such as when exiting or decelerating. The engine braking force can be increased only at high speeds. Furthermore, the 30th pickup control line h3
is set based on the lower limit of the turbine rotation speed within a range that does not cause engine stall, taking into consideration the response delay of the lock-up hydraulic system during braking.

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. 10 and subsequent figures.

FIG. 10 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, the ports of each control valve that switches the hydraulic control circuit of the automatic transmission and necessary counters are initialized, and the gear transmission mechanism 20 is set to first speed and the lock-up clutch 15 is set to released. After this, the electronic control circuit 200
Initialize the various working areas and complete the initialization settings.

Next, set the speed at which this flowchart is executed.
Subtract 1 from the value of timer 2 T and set that value as Tvc.
replace. This means that, for example, if the initial value T = 20, the timer T will be reset by performing the flow 20 times, and if the timer is reset every second, then the timer T will be reset every second. The program based on this flowchart is executed 20 times.

After this, a step of reading the position of the select valve 103, that is, the shift range is performed.

Next, it is determined whether the read shift range is lunge. 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 the 2nd range, a signal is generated to control the shift valve so as to release the lockup and shift the gear transmission mechanism 20 to the second speed, and then the process proceeds to step 81. On the other hand, when the above-mentioned determination of two ranges is No, the shift range is the D range, so a shift and lock-up map including a shift change control line and a lock-up 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. 11, and then the shift-down speed change control according to the shift-down speed change control subroutine shown in FIG.
Lockup control is performed in this order according to the lockup control subroutine shown in the figure, and the process advances to step S1.

Also, when it is determined that the shift range is lunge,
First, the lockup is released, and then it is calculated whether or not the engine will overrun when shifting down to first gear. Thereafter, based on this calculation, it is determined whether or not 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.

After this, the process advances to step SIN.

In step SIN, a delay of one fixed time is created in order to determine the speed at which this flowchart is executed. After creating a time delay of, for example, 50 msec, the flowchart is re-executed. This time delay in step S1 is related to the timer T. For example, if the initial value of the timer T is '&T=20, the time delay of 50 msec is repeated 20 times, resulting in a time delay of 1 second, so the timer T will be set every second.

Shift-up speed change control This shift-up speed change control is performed by first reading the gear position, that is, the position of the gear transmission mechanism 20, as shown in FIG.
The process starts by determining whether or not the current gear position is the fourth gear based on the read gear position. This judgment is Y
In the case of ES, no further upshifts can be performed, so the upshift speed change control is ended.

On the other hand, if the determination as to whether or not it is 4th speed is No, the throttle opening is read by the throttle opening sensor 204, and the map for upshifting shown in FIG. 12, for example, corresponds to the read throttle opening. Turbine speed: Read TSP (MAP). That is, the first
In Fig. 2, the turbine rotation speed corresponding to the throttle opening is read on the shift-up shift line Lu (solid line).Next, at turbine speed 1, the actual turbine rotation speed: TSP4 is detected by the sensor 203. Then, compare it with the turbine rotation speed of MAP 2: TSP (MAP).

When TSP≦TSP(MAP), that is, when the actual turbine speed is on the lower side (left (111I)) than the upshift line Lu (solid line) in Fig.
P(MAP)Xo, 2nd shift up shift line L which is 8
Set u' (dashed line) and compare TSP(MAP)Xo,8 and TSP. TSP)TSP(MAP)X08
When , that is, when the TSP is located on the higher rotation side than the second upshift line Lu' (broken line), the upshift control is ended.

When TSP≦TSP(MAP)xo, 8, that is, the second
Lower rotation side [T
When SP is located, the flag is set to 1-0 and the upshift speed change control is ended. This flag 1 is set when an upshift is executed, and is used to store the upshift state.

TSP)TSP(MAP), that is, when TSP is on the higher rotation side than the upshift line Lu in FIG. 12, it is determined whether the flag is 1-1 or not, and the
When this happens, it indicates that an upshift has already been performed, and the upshift speed change control ends as it is. When the flag is 1-00, the flag is set to 1-1 and then an upshift is performed. At this time, a lock-up release timer is activated at the same time as the shift-up to release the lock-up for a predetermined period of time to perform a smooth shift, and the shift-up shift control is completed.

When the upshift speed change control is completed as described above, the downshift speed change control shown in FIG. 13 is then executed.

Shift-down speed change control This shift-down speed change control first reads the gear position, that is, the position of the gear transmission mechanism 20, and based on this read gear position, it is determined whether or not it is currently in the first gear. You can start. This judgment is YES
In this case, no further downshifts can be performed, so the downshift control is ended.

On the other hand, when the determination as to whether or not the first gear is in the first speed is NO, the throttle opening is read by the throttle opening sensor 204, and for example, in the shift I/down map shown in FIG. 14, the turbine corresponding to the throttle opening is Speed =
Read TSP (MAP). That is, in FIG. 14, the turbine rotation speed corresponding to the throttle opening at the shift down shift line Ld (solid line) is read. Next, the actual turbine rotation speed: T S P is detected by the turbine rotation speed sensor 203 and compared with the turbine rotation speed: TSP (MAP) on the map.

When TSP≧TSP(MAP), that is, when the actual turbine speed is on the higher side (right side) than the downshift shift line Ld (solid line) in FIG.
) xl, 25 is set, and the second downshift line Ld/(broken line) is set, and TSP (MAP) Xl, 25 is compared with TSP. TSP (TSP(MAP)Xl, 2
5, that is, when the TSP is located on the lower rotation side than the second downshift line Ld/ (broken line), the downshift control is ended.

When TSP≧TSP(MAP)Xl, 25, that is, when TSP is located on the higher rotation side than the second downshift line Ld/ (broken line), the flag 2-0 is set and the downshift control is ended. This flag 2 is set when a downshift is executed and is used to store the downshift state.

When TSP (TSP (MAP)), that is, when there is KTSP on the lower rotation side than the downshift shift line Ld in Fig. 14, it is determined whether the flag is 2-1 or not. The flag indicates that the downshift is not being performed, and the downshift control is ended as is.Flag 2
When the flag is -0, the flag is set to 2-1, and then a downshift is performed. At this time, a lock-up release timer is activated at the same time as the downshift to release the lock amplifier for a predetermined period of time to allow a smooth shift, and the downshift shift control is completed.

When the downshift control is completed as described above, the lockup control shown in FIG. 15 is executed next.

Lock-up control This lock-up control first reads the lock-up release timer, and when the lock-up release timer is operating, that is, when the determination of whether or not the timer is 0 is NO, the lock-up is released and this flow ends. Conversely, if the determination as to whether the timer is 0 is YES, a preset lockup release map (1) is read out. This lockup release map (1) is shown by a broken line in FIG. 16A, and consists of a 10th pickup control line and a 30th pickup control line. Then, the turbine rotation speed: TSP (MAP) on the lock-up release map (1) corresponding to the throttle opening at this point is read, and this is compared with the actual turbine rotation speed TSP read by the turbine rotation speed sensor 203. . TSP≦TSP(MA
P), that is, in Figure 1.6A, the release map (
When the actual turbine rotation speed is lower than the broken line in 1), the lockup is released and the lockup control is terminated. When TSP≧TSP(M A P ), the first
Turbine rotation speed T S P / (M A
P ) is read. In this case, when the throttle opening is large, there is no corresponding turbine rotation speed, but at this time, the TS
P/(MAP) - Assuming that the throttle opening is small, two corresponding turbine rotational speeds will appear, and the smaller of these will be taken as TSP/(MAP). Next, the actual turbine rotation speed TSP4 is read and this TSP is compared with the above TSP' (MAP).

TSP) TSP/(MAP), the lock-up release setting turbine rotation speed: TSP (1) shown by the vertical line in the lock-up release map (2) is read and compared with the actual turbine rotation 1TSP. TSP (TSP
In case (1), the lockup is released and this flow ends.

”, when it is determined that TSP≦TSP/(MAP) or when it is determined that TSP≧TSP (1), the preset lock-up operation map (1
) (Fig. 16A), and after reading the turbine rotational speed TSP (MAP) corresponding to the actual throttle opening on this operation map (1), detect the actual turbine rotational speed TSP, and Compare. TSP
If it is determined that ≦TSI)(MAP), the lockup is maintained as it is and the flow ends. T.S.
P) When it is determined that TS, P (MAP), the preset lock-up operation map (2) (Fig. 16B) is read, and on this operation map (2), the turbine corresponding to the actual throttle opening is Rotation speed TSP' (MAP)
Read. In this case, the throttle opening is large (if there is no turbine rotation speed corresponding to the cono throttle opening, the TS
P/(MAP)-■, and when the throttle opening is small and there are two turbine rotational speeds corresponding to the throttle opening, the smaller turbine rotational speed is T S P/ (MAP
).

Next, read the actual turbine rotation speed TSP, and this TSP
and the above TSP/(MAP). TSP (TS
When it is determined that P/(MAP), lockup is activated and this control flow is ended. Also, TSP≦TSP
'(MAP), read the lock-up operation setting turbine rotation speed: TSP (2) shown by the vertical line on the lock-up operation map (2) and compare it with the actual turbine rotation speed: TSP. .

TSP) When it is determined that TSP(2), the lockup is activated, and when it is determined that TSP≦TSP (2), the lockup is maintained as it is and the control flow is terminated.

[Brief explanation of drawings]

The first graph shows the output torque characteristics when the engine is rotated without load, and the second graph shows the engine rotation speed when changing the throttle opening and fuel consumption.
Figure 2A is a graph showing output torque characteristics, Figure 2A is a graph showing engine no-load before fuel consumption, Figure 3 is a graph showing engine turbine complete full throttle and partial load performance, Figure 4 is a turbine torque map. 5 is a graph showing the engine speed at each throttle opening. FIG. 6 is a graph showing the driving force characteristics of an automatic transmission incorporating a conventional lock-up control device. Throttle opening indicating lock-up area -
7 is a block diagram showing the structure of a lock-up control device for an automatic transmission according to an embodiment of the present invention, and FIG. 8 is a graph of turbine rotation speed characteristics. FIG. 9 is a block diagram showing an electronic control circuit of the automatic transmission; FIG. 9A is a diagram showing a shift up map, a shift down map, and a lock up map; 10, 11, 13, and 15 are flowcharts of shift and lock-up control according to the present invention, and FIGS. 12, 14, 16A, and 16B are
FIG. 3 is a diagram showing a shift-up map, a shift-down map, and a lock-up map, respectively. a・・・・・・・・・・・・Engine b・・・・・・
......Turbine C......Transmission gear mechanism d...Lockup means e...
・・・・・・・・・・・・Electromagnetic means f・・・・・・
・Turbine rotation speed sensor g...Load sensor
Lock-up determination means J...
...... Control means 1o...
・・・・・・＋Luc converter 11・・・・・・・・・Po
12...Turbine 100...
...Hydraulic pump 103...Song/Select valve 200...Electronic control circuit 203...Turbine rotation speed sensor 204...Throttle opening sensor 205...Song... Gear position sensor -525- F/,, recorded) Fuji? Piro iJ-Island 5 Itshikiku-ku, -I-X-2 ¥2 1<mouth>work 2nd 2

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 lock-up means for connecting and disconnecting the input shaft and the peak shaft of the torque converter to switch the power transmission path, an electromagnetic means for controlling the supply of pressure fluid to the lock-up means for operating the lock-up means, and an output of the torque converter. A turbine rotation speed sensor that detects the shaft rotation speed, an engine load sensor that detects the magnitude of the load on the engine, an output signal of the turbine rotation speed sensor, and an output signal of the engine load sensor are input, and these two output signals are input. lock-up determination means for generating a lock-up on/off signal by comparing the lock-up control line with a lock-up control line set and stored in advance, and receiving the lock-up on/off signal and driving the electromagnetic means based on the on/off signal. control means for controlling activation/release of the lock-up means, the lock-up determining means:
a tenth pull-up control line preset based on the turbine rotational speed of the torque converter and the load of the engine in a state where the ratio of the output torque of the engine to the output torque of the torque converter can be considered to be 1; The 20th pull-up control line is preset based on the turbine rotation speed and the engine load in a state where the output can be considered to be zero, and at least the lower limit of the turbine rotation speed is used as a boundary line that allows the operation of the lock-up means. 30th preset based on the rotation speed
The 20th pull-up control line is provided only in a region where the turbine rotation speed is equal to or less than the predetermined value, and from the point where the turbine rotation speed reaches the predetermined value, the 20th pull-up control line is A lock-up control device for an automatic transmission, characterized in that the throttle opening is rotated to a point where the throttle opening becomes zero.