JPH0468500B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electronically controlled automatic transmission, and more particularly to an electronically controlled automatic transmission used in a traveling vehicle such as an automobile. Automatic transmissions commonly used today include a torque converter connected to the output shaft of the engine,
It is connected to the output shaft of the torque converter and is configured in combination with a multi-stage gear type transmission mechanism having a gear mechanism such as a planetary gear mechanism. A hydraulic mechanism is normally used for speed change control of such automatic transmissions, and the hydraulic circuit is switched using a mechanical or electromagnetic switching valve, thereby reducing the friction of the brakes, clutches, etc. associated with the multi-gear type transmission mechanism. The engine power transmission system is switched by operating elements as appropriate to obtain the desired gear position. When switching a hydraulic circuit using an electromagnetic switching valve, for example,
As shown in No. 53-79159, the vehicle driving condition indicated by the engine speed, turbine speed, or vehicle speed and engine load, i.e., throttle opening, exceeds a predetermined shift line. Normally, the detection is performed by an electronic device equipped with a microcomputer, and the electromagnetic switching valve is selectively operated in response to an output signal from the electronic device, thereby switching the hydraulic circuit and shifting the speed. Such an electronically controlled automatic transmission can automatically perform gear change control according to the driving condition of the vehicle, and can drive in a desired gear position.
Since the above-mentioned shift line is fixed, the shift is not necessarily carried out under optimal conditions with few shift shocks due to variations in the engine and vehicle weight of each vehicle. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electronically controlled automatic transmission that can correct the shift line for each vehicle, thereby allowing the vehicle to shift in the most desirable state with the smallest shift shock. That is. That is, the present invention provides a torque converter connected to the output shaft of an engine, a speed change gear mechanism connected to the output shaft of the torque converter, and a speed change switching means for switching the power transmission path of the speed change gear mechanism to perform a speed change operation. , a hydraulic actuator for operating this speed change switching means, an electromagnetic means for controlling the supply of pressure fluid to this hydraulic actuator, and a rotation for detecting any one of engine rotation speed, turbine rotation speed, and vehicle speed. A number of sensors, an engine load sensor that detects the size of the engine load, an output signal of the rotation speed sensor, and an output signal of the engine load sensor are input, and these output signals are compared with a pre-stored shift line. In an electronically controlled automatic transmission equipped with a control means that determines whether or not to perform a gear shift and controls the electromagnetic means based on this determination to perform an automatic gear shift, the problem occurs during a gear shift. Based on a shift shock sensor that detects a shift shock, and an output signal from this shift shock sensor, the shift line stored in the control means is moved in the direction of the engine rotation speed, turbine rotation speed, or vehicle speed where the shift shock becomes smaller. The present invention is characterized in that it includes a shift line shifting means for shifting the shift line. In the electronically controlled automatic transmission of the present invention having the above configuration, the shift line shifting means biases the shift line stored in the control means based on an output signal indicating a shift shock from the shift shock sensor. Since the shift line can be shifted, the optimum shift line for the vehicle can be obtained, and therefore the shift operation can be performed under optimal conditions with fewer shift shocks. DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronically controlled automatic transmission according to a preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a cross section of a mechanical part and a hydraulic control circuit of an electronically controlled automatic transmission according to an embodiment of the present invention. 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. The torque converter 10 includes a pump 11 coupled to an engine output shaft 1, a turbine 12 disposed opposite the pump 11, and a stator 13 disposed between the pump 11 and the turbine 12. A converter output shaft 14 is coupled to the converter output shaft 14 . Converter output shaft 14 and pump 1
A lock-up clutch 15 is provided between the lock-up clutch 1 and the lock-up clutch 15. This lockup clutch 15 is
The clutch 1 is constantly pushed in the engagement direction by hydraulic oil pressure circulating within the torque converter 10.
5 is maintained in the released state by release hydraulic pressure supplied from the outside. The multi-stage gear transmission mechanism 20 includes a front planetary gear mechanism 2
1 and a rear planetary gear mechanism 22, and a sun gear 23 of the front planetary gear mechanism 21 and a rear planetary gear mechanism 22.
It is connected to the sun gear 24 by a connecting shaft 25. The input shaft 26 of the multi-stage gear transmission mechanism 20 is connected to the connecting shaft 25 via a front clutch 27 and to the internal gear 29 of the front planetary gear mechanism 21 via a rear clutch 28, respectively. The connecting shaft 25, that is, the sun gear 23,
24 and the transmission case is the front brake 30.
is provided. The planetary carrier 31 of the front planetary gear mechanism 21 and the internal gear 33 of the rear planetary gear mechanism 22 are connected to an output shaft 34, and a rear brake 36 is connected between the planetary carrier 35 of the rear planetary gear mechanism 22 and the transmission case.
A one-way clutch 37 is provided. The overdrive planetary gear transmission mechanism 50 is
A planetary carrier 52 that rotatably supports a planetary gear 51 is connected to the output shaft 14 of the torque converter 10, and a sun gear 53 is connected to an internal gear 55 via a direct coupling clutch 54. An overdrive brake 56 is provided between the sun gear 53 and the transmission case, and the internal gear 55 is connected to the input shaft 26 of the multi-gear transmission mechanism 20. The multi-gear transmission mechanism 20 is of a conventionally known type and has three forward speeds and one rear speed.
28 and the brakes 30 and 31 as appropriate, a desired gear stage can be obtained. The overdrive planetary gear transmission 50 connects the shafts 14 and 26 in a direct connection state, when the direct coupling clutch 54 is engaged and the brake 56 is released, and when the brake 56 is engaged and the clutch 54 is released. Shafts 14 and 26 are coupled in overdrive. The automatic transmission described above includes a hydraulic control circuit as shown in FIG. This hydraulic control circuit includes an oil pump 100 driven by an engine output shaft 1.
The pressure of the hydraulic oil discharged into the pressure line 101 is regulated by the pressure regulating valve 102 and the pressure is adjusted by the select valve 1.
Guided to 03. The select valve 103 has 1, 2,
The pressure line 101 has shift positions D, N, R, and P, and 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. Port a is connected to an actuator 104 for actuating the rear clutch 28, which is held engaged when the valve 103 is in the position described above. Port a is also connected near the left end of the 1-2 shift valve 110, pushing its spool to the right in the figure. port a
is further connected to the right end of the 1-2 shift valve 110 via the first line L1 and to the 2-2 shift valve 110 via the second line L2.
The right end of the 3-shift valve 120 is connected to the right end of the 3-4 shift valve 130 via the third line L3. From the first, second and third lines L1, L2 and L3, the first, second and third lines L1, L2 and L3 respectively
Second and third drain lines D1, D2 and D
3 are branched, and these drain lines D1,
D2, D3 have these drain lines D1, D2,
First, second, and third solenoid valves SL1, SL2, and SL3 are connected to open and close D3. The above solenoid valves SL1, SL2, SL3 are connected to line 101.
When the drain lines D1, D2, and D3 are energized while communicating with the port a, the drain lines D1, D2, and D3 are closed, thereby increasing the pressure in the first, second, and third lines. Port b is also connected to second lock valve 105 via line 140, and this pressure acts to force the spool of valve 105 downward in the figure. When the spool of the valve 105 is in the lower position, lines 140 and 141 communicate with each other, and hydraulic pressure is introduced into the engagement side pressure chamber of the actuator 108 of the front brake 30 to hold the front brake 30 in the operating direction. Port c is second lock valve 1
05, and this pressure acts to push the spool of the valve 105 upward. Further, port c is connected to a 2-3 shift valve 120 via a pressure line 106. This line 106
is the solenoid valve SL2 of the second drain line D2
is energized to increase the pressure in the second line L2, and when this pressure moves the spool of the 2-3 shift valve 120 to the left, the line 107
communicate with. The line 107 is connected to the release side pressure chamber of the front brake actuator 108,
When hydraulic pressure is introduced into the pressure chamber, the actuator 108 operates the brake 30 in the releasing direction against the pressure in the engagement side pressure chamber. Also, line 10
7 of pressure is also directed to the actuator 109 of the forward clutch 27, causing it to engage. The select valve 103 has a port d leading to the pressure line 101 in one position, and this port d
passes through line 112 to the 1-2 shift valve 110, and further passes through line 113 to the rear brake 36.
is connected to the actuator 114 of. When the solenoid valves SL1 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 and 2-3 are performed, respectively. The hydraulic control circuit also includes a cutback valve 115 that stabilizes the hydraulic pressure from the pressure regulating valve 102;
Vacuum throttle valve 11 that changes the line pressure from the pressure regulating valve 102 according to the magnitude of intake negative pressure
6. A throttle backup valve 117 is provided to assist the throttle valve 116. Further, the hydraulic control circuit of this example includes a 3-4 shift valve 1 for controlling a clutch 54 and a brake 56 of an overdrive planetary gear transmission 50.
30 and an actuator 132 are provided. The engagement side pressure chamber of the actuator 132 is connected to the pressure line 101.
The brake 56 is pushed in the engaging direction by the pressure. This 3-4 shift valve is also 1-2, 2-3 above.
Similar to the shift valves 110 and 120, solenoid valves
When SL3 is energized, the spool 13 of the valve 130
1 moves downward, pressure line 101 and line 1
22 are in communication, and hydraulic pressure is introduced into the line 122. The hydraulic pressure introduced into the line 122 acts on the release side pressure chamber of the actuator 132 of the brake 56, actuating the brake 56 in the release direction and causing the actuator 132 of the clutch 54 to engage the clutch 54. Further, the hydraulic control circuit of this example is provided with a lock-up control valve 133, which is connected to the select valve 1 via a line L4.
It is connected to port a of 03. This line L
A drain line D4 is branched from the drain line D4 and is provided with a solenoid valve SL4, similar to the drain lines D1, D2, and D3. Lockup control valve 13
3, when the solenoid valve SL4 is energized, the drain line D4 is closed, and the pressure in the line L4 increases, the spool connects the lines 123 and 124, and the lock-up clutch 15
is designed to move in the direction of release. In the above configuration, the operational relationship between each gear position, lockup, and each solenoid, and the operational relationship between each gear position, clutch, and brake are shown in the following table.

【table】

【table】

[Table] Next, an electronic control circuit 200 for controlling the operation of the hydraulic control circuit will be described with reference to FIG. The electronic control circuit 200 includes an input/output device 201, a random access memory 202 (hereinafter referred to as RAM), and a central processing unit 203 (hereinafter referred to as CPU). The input/output device 201 includes a load sensor 2 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 S _L.
07, and an engine rotation speed sensor 208 that detects the rotation speed of the engine output shaft 1 and outputs an engine rotation speed signal S _E , and an engine rotation speed sensor 208 that detects the rotation speed of the converter output shaft 14 and outputs a turbine rotation speed signal S _T. A sensor that detects the driving state, such as a turbine rotation speed sensor 209 that detects the vehicle speed, or a vehicle speed sensor (not shown) that detects the vehicle speed and outputs a vehicle speed signal, is connected, and the above-mentioned signals, etc. are input from these sensors. It's getting old. The input/output device 201 processes the load signal S _L , engine speed signal S _E , turbine speed signal S _T , and vehicle speed signal received from the sensor and supplies them to the RAM 202 . The RAM 202 receives these signals S _L ,
It stores the signals S _E and _ST and supplies these signals S _L , S _E , _ST or other data to the CPU 203 in response to instructions from the CPU 203 . CPU20
3 is the engine rotation speed - engine load obtained by reading out the engine rotation speed signal S _E , the turbine rotation speed signal _ST or the vehicle speed signal according to the load signal S _L according to the shift control program compatible with the present invention. The shift line is determined based on the characteristics, turbine speed-engine load characteristics, or vehicle speed-engine load characteristics (Figure 3 shows the one based on engine speed and turbine speed). and performs operations for lockup. The calculation results of the CPU 203 are sent to the input/output device 201
1-2 shift valve 110 and 2-3 shift valve 12, which are the speed change control valves 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, 3-4 shift valve 130 and the lock-up control valve 133, thereby performing speed change or lock-up control. The solenoid valve group 211 includes solenoid valves SL1, SL of the 1-2 shift valve 110, 2-3 shift valve 120, 3-4 shift valve 130, and lock-up control valve 133.
2, SL3, and SL4 are included. The input/output device 201 of the electronic control device 200 further detects a shift shock and outputs a shock signal S _s
The shift shock sensor 210, which is a G meter etc. that outputs the output torque, detects the output torque and outputs the torque signal
A torque sensor 211 that outputs S _p is connected. The electronic control device 200 receives the above-mentioned shock signal S _s
Based on the relationship between the shock signal S _s and the torque signal S _p , the above shift line is shifted as shown by the broken line in Fig. 3, and the shift line when the shift shock is the smallest during the shift operation is determined. Since the shift line is detected and the shift control is performed based on this shift line, shift shocks that occur during shift operations can be reduced. An example of control of the automatic transmission AT by the electronic control circuit 200 will be described below. Electronic control circuit 2
00 is preferably constituted by a microcomputer, and a program incorporated in this electronic control circuit 200 is executed, for example, according to the flowchart shown in FIG. 4 and subsequent figures. FIG. 4 shows an overall flowchart of the shift control, and as can be seen from this figure, the shift control is first performed from initialization settings. This initialization setting is executed according to the initialization subroutine shown in FIG. This subroutine initializes the ports of each control valve for switching the hydraulic control circuit of the automatic transmission and necessary counters to set the gear transmission mechanism 20 to first gear and the lock-up clutch 15 to release. Thereafter, various working areas of the electronic control circuit 200 are initialized, and the execution of the initialization subroutine is completed. Next, after applying a delay of, for example, 50 msec., a preset timer value T is read, and after subtracting "1" from this value, the select valve 103 is
Read the position, that is, the shift range. Next, it is determined whether the read shift range is the 2nd range. When the shift range is the 2nd range, the shift valve is controlled so as to release the lockup and fix the gear transmission mechanism 20 at the 2nd speed. If the shift range is not the 2nd range, it is determined whether the shift range is the 1st range. If the shift range is 1 range, then it is determined whether the gear transmission mechanism is currently in the 1st speed.
If it is the first speed, the above routine is repeated. On the other hand, if it is not the 1st gear, the lockup is released and then the shift line corresponding to the 1st gear is read out. Note that this shift line is determined according to the turbine rotation-engine load characteristics.
Next, the turbine rotation speed (T _sp ) is detected, this turbine rotation speed is compared with the shift line read above, and if the turbine rotation speed does not exceed the above shift line, it is fixed at first gear, and it is In this case, first the second speed is set, and if the above conditions are satisfied, the first speed is fixed. This is to prevent gear shifting shock. In determining whether or not the shift range is in the 1st range, if the shift range is not in the 1st range, this indicates that the shift range is in the D range after all, and in this case, shift-up speed change control including a shift-up determination is first performed. This shift-up speed change control is executed according to the shift-up speed change control subroutine shown in FIG. This shift-up speed change control is performed by first reading out the gear position, that is, the position of the gear transmission mechanism 20. Next, based on this read gear position, it is determined whether or not the vehicle is currently in fourth gear. When it is in 4th gear, it returns and re-does the control, while when it is not in 4th gear, it reads out the current throttle opening and then changes the gears at once to two gears according to the read mode and throttle opening. Reads the skip shift up map. Next, read out the actual engine speed (E _sp ), compare this engine speed with the shift line shown in the shift up map read out above, for example M _su in Figure 3, and compare the engine speed with the throttle opening. It is determined whether or not the engine speed is greater than the set engine speed indicated by the shift line M _su in the relationship. When the actual engine speed is smaller than the set engine speed in relation to the throttle opening, a 1st shift up map corresponding to the current throttle opening is read out. Next, compare the actual engine speed E _sp with the shift line indicated by M _fu in FIG. 3 of the above shift up map,
It is determined whether or not this actual engine speed E _sp is larger than the set engine speed indicated by this shift line M _su in relation to the throttle opening degree. If this determination is NO, the control routine is restarted by returning to the start, while if the determination is YES, a one-step upshift is performed. Next, map correction control according to the present invention is performed. This map correction control is performed according to the map correction control subroutine shown in FIG. This map correction control is performed by first reading out the output shaft torque immediately after the shift. Next, by reading out the maximum value S _nax of the shift shock that occurred in one second after this shift, and reading out the shock/torque mode changeover switch,
The shock/torque mode k, which will be explained in detail later, is read out. Thereafter, an index _Kl for determining whether or not the shift point is the optimum one is calculated from the formula _Kl =kT/S _nax . Here, k indicates the torque shock mode as described above, weights the output torque with respect to the shock, and takes a value of, for example, 1/10 to 1/1. Thereafter, it is determined whether or not this is the first time a gear change operation is being performed at the engine speed _Esp and throttle opening. When this judgment is YES, the index K _l
is stored as an index k _1l for the next map correction control. Next, add, for example, 100 rpm to the shift line of the current shift map (shown by the broken line in Figure 3).
is set as a new shift map, stored, and control is completed in preparation for the next shift control. On the other hand, if the above determination is NO, that is, if it is not the first time that the gear change is being performed at the engine speed _Esp and the throttle opening, it is determined whether or not an end flag, which will be described later, is set. This judgment
When YES, the control is completed and the next shift control is prepared. On the other hand, when this judgment is NO, the index K _l calculated above is used as the index K l calculated and stored in the previous map correction control. It is determined whether it is equal to _1l . If this determination is YES, an end flag is set, the control is completed, and preparations are made for the next shift control. If the above judgment of K _l = K _1l is NO, then K _l > K _1l
Make a judgment. If this judgment is YES,
Set a new shift map by adding 100 rpm to the shift line of the current shift map, and store it. Thereafter, it is determined whether this new shift map is smaller than the positive limit value MAP _linit of the shift map. This limit value MAP _linit
should be between 200 and 300 rpm based on the map at the design stage. If this judgment is NO, the limit value
Set MAP _linit as a new shift map, store it, complete control, and prepare for the next shift control. When the above determination of MAP>MAP _linit is YES, _Kl is set and stored as _K1l , the control is completed, and the next control is prepared. On the other hand, when the determination of K _l > K _1l is NO, the appropriate shift map is likely to be on the low speed side rather than the high speed side as described above, so subtract 100 rpm from the current speed change map. Store the settings as a new shift map. After this, this new shift map is set to the negative limit value of the shift map.
It is determined whether it is greater than MAP _linit . This limit value MAP _linit is obtained from the map at the design stage.
It should be between 200 and 300 rpm. This judgment is NO
In this case, the limit value MAP _linit is set as a new shift map, this is stored, an end flag is set, the control is completed, and the next shift control is prepared.
If the above MAP > MAP _linit judgment is YES,
Set and store K _l as K _1l to complete the control and prepare for the next control. By repeating the above map correction control together with the shift control, it is possible to obtain the most desirable shift line for each vehicle. When the first determination of MAP<E _sp in the shift-up speed change control shown in FIG. After that, map correction control shown in FIG. 7 is performed in the same manner as above, and all shift-up speed change control is completed. The downshift control is executed according to the downshift control subroutine shown in FIG. This downshift control, like the upshift control, is performed by first reading out the gear position and then determining whether or not the gear is currently in the first gear based on the read out gear position. If it is not the first speed, the current throttle opening is read out, and then a skip shift down map corresponding to the read throttle opening is read out. Next, read out the actual turbine rotation speed T _sp , and apply this turbine rotation speed to the skip shift down map read out above, for example in Figure 3.
In light of the skip shift-down transmission indicated by M _sd , determine whether the turbine rotation speed T _sp is smaller than the set turbine rotation speed indicated by the skip shift-down transmission line M _sd in relation to the throttle opening. judge. When this determination is NO, a shift down map for downshifting by one stage according to the throttle opening degree is read out. Next, the actual turbine speed
T _sp is compared with the downshift line M _fd of the shift down map read above (see Figure 3), and the turbine rotation speed T _sp is shown on the down shift line M _fd in relation to the throttle opening. Determine whether the rotation speed is smaller than the set turbine rotation speed. This judgment
If NO, return to start and resume control.
When YES, downshifts one gear. After performing this one-stage downshift, map correction control shown in FIG. 7 is performed in the same way as in the case of shift-up speed change control. When the above first judgment of MAP>T _sp is YES, the engine speed has decreased enough to perform a skip shift down, so a skip shift down operation is performed, and then Similarly to the above, the map correction control shown in FIG. 7 is performed to complete the downshift control.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a cross section of a mechanical part and a hydraulic control circuit of an electronically controlled automatic transmission according to an embodiment of the present invention, and FIG. 2 is a diagram showing an electronic control circuit of the electronically controlled automatic transmission described above. A schematic diagram, FIG. 3 is a diagram showing an example of a shift map, FIG. 4, FIG. 5, FIG. 6,
FIGS. 7 and 8 are flowcharts of speed change control according to the present invention. 10...Torque converter, 11...Pump,
12...Turbine, 100...Hydraulic pump, 10
3...Select valve, 200...Electronic control circuit, 2
07... Load sensor, 208... Engine rotation speed sensor, 209... Turbine rotation speed sensor, 21
0...Shift shock sensor, 211...Torque sensor.

Claims (1)

[Claims] 1. A torque converter connected to the output shaft of an engine, a speed change gear mechanism connected to the output shaft of the torque converter, a speed change switching means for switching a power transmission path of the speed change gear mechanism to perform a speed change operation, and this speed change switching means a hydraulic actuator for operating the hydraulic actuator; an electromagnetic means for controlling the supply of pressure fluid to the hydraulic actuator; a rotational speed sensor for detecting any one of engine rotational speed, turbine rotational speed, and vehicle speed; The engine load sensor that detects the magnitude of the load, the output signal of the rotation speed sensor, and the output signal of the engine load sensor are input, and these output signals are compared with a pre-stored shift line to perform gear shifting. In an electronically controlled automatic transmission equipped with a control means for automatically shifting, a gear shift shock occurring during gear shifting is detected by determining whether or not the transmission is false and controlling the electromagnetic means based on this determination. A shift shock sensor, and a shift line that, based on an output signal from the shift shock sensor, shifts the shift line stored in the control means in the direction of engine rotation speed, turbine rotation speed, or vehicle speed where the shift shock becomes smaller. An electronically controlled automatic transmission characterized by being provided with a shifting means.