JPS6011262B2 - Electronically controlled automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electronically controlled variable transmission in which each gear stage can be obtained by electronically controlling the drive of a shift solenoid.

When driving downhill with a hydraulically controlled variable transmission with its manual valve in the automatic shift (D) range, the furthest gear remains selected, and engine braking can hardly be expected, especially when driving down a steep slope. In order to avoid having to use the foot brake frequently when going down a long distance downhill, the driver should change the manual valve from the D range to the 2nd gear fixed range or the 1st far fixed range, and adjust the manual valve each time to ensure that the engine brake is effective. It is necessary to perform the above manual operation. In this respect, the conventional electronically controlled Mesardine transmission was similar, but in order to eliminate this complexity, the Subaru transmission automatically shifted to the furthest distance even if it remained in the ○ range when the brake pedal was depressed. An electronically controlled variable transmission has been developed that shifts down from one gear to the immediately preceding low gear. However, with such an electronically controlled shift transmission, each time the brake pedal is stepped on to brake the vehicle, the downshift is performed even when the vehicle is not actually requiring engine braking, causing discomfort to the occupants. The reality was that the driver felt a sense of deceleration every time he braked, which seriously impaired the driving feeling. From this point of view, the present invention provides, in a driving state where the acceleration of the vehicle is equal to or higher than a set value,
In addition, only when the driver takes his foot off the accelerator pedal and depresses the brake pedal, that is, only when driving downhill when engine braking is really required, will the system automatically downshift and apply engine braking appropriately. This is an improved version of the electronically controlled variable transmission.

However, with this improved electronically controlled transmission, when the vehicle acceleration exceeds a set value after taking your foot off the accelerator pedal and pressing the brake pedal, it automatically reduces the speed to apply engine braking. For vehicles that shift, if you take your foot off the accelerator pedal and step on the brake pedal immediately after sudden acceleration while driving on a flat road, the vehicle acceleration may be affected by the sudden acceleration during this brake operation. Since the set acceleration may be exceeded, in this case as well, even though there is no need for engine braking as the vehicle is actually traveling on flat ground, the system downshifts from the furthest gear to the immediately preceding lower gear due to the satisfaction of the above three conditions. It was confirmed that it was not possible to completely prevent the deterioration of the driving feeling.

Therefore, the present invention provides an accelerator pedal release signal, which is one of the engine brake conditions, only when the accelerator pedal release signal continues to be output for a certain period of time, and if it is assumed that the engine brake condition related to this signal is satisfied, then the brake pedal is released during the certain period of time. Since the vehicle decelerates when the driver depresses the pedal, there is no pointless downshifting in the above-mentioned flat road driving condition, and accurate engine braking is obtained without any deterioration of the driving feeling. This is a concrete embodiment of this idea from the perspective of being able to do the following.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows a power transmission system of a typical automatic transmission, in which power is input from an input shaft 1, and this power is transmitted to an intermediate shaft 3 via a torque converter 2. The intermediate shaft 3 can drive and engage the sun gears 8 and 9 of the front planetary gear set 6 and the rear planetary gear set 7 via the front clutch 4, and also engages with the internal gears 10' of the front planetary gear set 6 via the rear clutch 5. It is also possible to engage the drive. The sun gears 8 and 9 can be further fixed by a band brake 11, and the carrier 13 supporting the pinion 12 of the front planetary gear set 6 and the internal gear 14 of the rear planetary gear set 7 are fixed to the output shaft 1, respectively.
5 so that power can be output from this output shaft. The pinion 16 of the rear planetary gear set 7 is supported by a carrier 17, which can be fixed by a low and reverse brake 18 and can rotate only in one direction via a one-way clutch 19. This transmission system includes a torque converter 2 and a front clutch 4.
, the rear clutch 5, the band brake 11, and the gear train portion including the friction elements of the low and reverse brake 18 are housed in a converter cover 20 and a transmission case 21, respectively, shown in FIG. An extension 22 is provided.

FIG. 2 generally shows the electronic control system of the automatic transmission of the present invention, and this electronic control system includes a cutback solenoid 23, 1-2
Shift solenoid 24 and 2-3 shift solenoid 25
, a far-vehicle sensor 26 , a throttle opening sensor 27 ,
As an idle detection means that detects when the accelerator pedal 28 is released in conjunction with the accelerator pedal 28, the idle detection means detects when the accelerator pedal 28 is released.
N'Konaru idle switch 29 and brake pedal 3
A brake switch 31 that is turned on when the brake pedal 30 is depressed is used as a brake operation detection means that detects when the brake pedal 30 is depressed in conjunction with the brake switch 31 as shown in the second figure.
It is constructed in correlation with 2. In addition, the idle switch 29
, a switch that compares the outputs of the brake switch 31 and the throttle relationship sensor 27 with a predetermined value using a comparator and responds to the output of the comparator, and a switch that operates when the depression force on the brake pedal 30 exceeds a predetermined value, respectively, as necessary. Can be used. The computer 32 processes various information as described later and controls the 1-2 shift solenoid 24 and the 2-3 shift solenoid 25 to turn on and off as shown in the following table, thereby depending on the manual valve selection position of the automatic transmission. , each of the friction elements described above can be selectively operated by a well-known and desired hydraulic circuit. (The circles in the following table indicate which friction elements are selectively activated.) In the present invention, in order to perform such ON/OFF control of the 1-2 shift solenoid 24 and the 2-3 shift solenoid 25 in Table 1, The computer 32 is configured as shown in FIG.

This computer 32 includes a throttle relationship detection circuit 33 to which a signal from the throttle opening sensor 27 is input, and a vehicle distance detection circuit 34 to which a signal from the vehicle speed sensor 26 is input.
These circuits each process the input signals and output a signal TH corresponding to the throttle function and a signal V corresponding to the distance of the vehicle. The throttle opening signal TH is the 1-2 shift determination circuit 35 for the ○ range and the 2-3 shift determination circuit 36 for the D range.
The vehicle speed signal V is input to the 1-2 shift determination circuit 35 for the ○ range, the 2-3 shift determination circuit 36 for the D range, the 1-2 shift determination circuit 37 for the 1st fixed range, and the 2-2 shift determination circuit 37 for the 2nd far fixed range. The signal is input to the third gear shift determining circuit 38. Shift determination circuit 3
5,36 also has a manual valve for the automatic transmission.
D range switch 39 that closes when range is selected
When the power supply +V is connected through the D range switch 39 and the power supply voltage is input, the speed change determining circuits 35 and 36 are activated, but otherwise the speed determining circuits 35 and 36 are inactive and the circuit NAND gate 42 via 40 and 41
, 43 output high (H) level signals.

Further, the shift determining circuits 35 and 36 store the required 1-2 shift pattern and 2-3 shift pattern, respectively, and when the switch 39 is closed, these shift patterns are input. Throttle related signal T
It is assumed that the driving state is determined by comparing H and the distance signal V, and an H level or low (L) level signal is output to circuits 40 and 41 as described later. speed change determination circuit 37,
A power supply +V is connected to 38 via the 1st selection range switch 44 and the 2nd far range switch 45, which are closed when the manual valve of the automatic transmission selects the 1st far fixed range and the 2nd far fixed range, respectively, and the gear shift is determined. The circuits 37 and 38 are connected to the 1st range switch 44 and the 2nd range switch 4, respectively.
5 is closed and a power supply voltage is input, but is otherwise inactive and outputs an H level signal to NAND gates 42 and 43 via circuits 46 and 47. Further, the shift determining circuits 37 and 38 store the vehicle far position when the engine reaches the upper limit of the allowable rotation speed at the first far and second far gears, respectively, and when the switches 44 and 45 are closed, these values are stored. Comparing the vehicle distance and the input vehicle speed signal V,
It is assumed that it is determined whether the vehicle speed is such that the engine overruns or not, and an H level or L level signal is output to circuits 46 and 47 as described later. In addition, NAND
The aforementioned 1-2 shift solenoids 24 and 2-3 shift solenoids 25 are connected to the output terminals of the gates 42 and 43, respectively, and these solenoids are turned ON when an H level signal is output to the corresponding NAND gate. It is assumed that the circuit is turned off when an L level signal is output. In the present invention, the following circuit for automatically applying engine braking is added to the above-mentioned speed change control circuit.

In addition to the idle switch 29 as idle detection means and the brake switch 31 as brake operation detection means, this circuit also includes acceleration determination means consisting of an acceleration detection circuit 48, an acceleration setting circuit 49, and a comparator 51, and a timer circuit 50. and a NOR gate 53 as an engine brake command means. The acceleration detection circuit 48 receives the signal from the vehicle speed sensor 26, continuously detects the increase or decrease in this signal at fixed time intervals, and calculates the acceleration of the vehicle by calculating the increase or decrease within a unit time of the vehicle distance. The value (acceleration signal) G is supplied to one input terminal of the comparator 51. Further, the acceleration setting circuit 49 supplies a signal GH regarding the set speed to the other input terminal of the comparator 51, and this set acceleration signal GH corresponds to the lower limit acceleration of the acceleration range in which the vehicle requires engine braking. The comparator 51 determines that the acceleration signal G is the set acceleration signal G.
When the acceleration signal G is larger than the set acceleration signal GH, the signal is at the L level.
It is assumed that the input signal is input to the OR gate 53.

One of the other two input terminals of the NOR gate 53 is connected to the power supply +V through the timer circuit 50 and the resistor 54 in sequence, and the other is connected to the power supply +V through the resistor 55.
and the timer circuit 50 are grounded via the idle switch 29, and the terminal of the resistor 55 far from the power supply +V is grounded via the brake switch 31.

Thus, when the idle switch 29 is turned off, the resistance 5
4 and the timer circuit 50 to the corresponding input terminal of the NOR gate 53, and when ON, the resistor 5 is connected to the corresponding input terminal of the NOR gate 53.
4, an L level signal (accelerator pedal release signal) can be input, and when the brake switch 31 is OFF, the voltage of the power supply +V (day level signal) can be input to the corresponding input terminal of the NOR gate 53 via the resistor 55. ), and an L level signal (brake pedal depression signal) can be input to the input terminal of the NOR gate 53 in the presence of the resistor 55 when it is ON. Timer circuit 5: When the accelerator pedal is released, the idle switch 29 is turned on and the NOR signal is activated as described above.
When an L level signal (accelerator pedal release signal) goes to the corresponding input terminal of the gate 53, this signal starts to be supplied to the corresponding input terminal of the NOR gate 53 after a certain period of time, and when the accelerator pedal is depressed, the idle switch is activated. 29 becomes OFH and a signal at H level is sent to the NOR gate 53, this signal can be immediately supplied to the corresponding input terminal of the NOR gate 53 without the above-mentioned time delay. The circuit from the timer circuit 50 to the corresponding input terminal of the NOR gate 53 is also connected to the set input terminal S of the flip-flop circuit 56.
The output terminal of the NOR gate 53 is connected to the reset input terminal R of the
Connected to one input terminal of ND gate 43.

The flip-flop circuit 56 outputs an H level signal from the terminal Q when an H level signal is input to the set input terminal S, and outputs an L level signal from the terminal Q when an H level signal is input to the reset input terminal R. In addition to outputting a signal, this L level signal is held until an H level signal is input to the set input terminal S. The electronic control circuit of the automatic transmission of the present invention configured as described above operates as described below. When the driver desires to start the vehicle and puts the manual valve in the D range, the switch 39 is closed and the shift determining circuits 35 and 36 start operating.

At this time, the throttle relation signal TH and vehicle distance signal V are low, and the shift determining circuits 35 and 36 compare the shift patterns stored in these signals with the above-mentioned signals TH and V. It is determined that there is one, and an L level signal is supplied to NAND gates 42 and 43 via circuits 40 and 41. As a result, the NAND gates 42 and 43 each accept an H level signal as 1 regardless of other input signals.
- Output to the 2nd shift solenoid 24 and 2-3rd shift solenoid 25, and turn these solenoids ON' to bring the automatic transmission into a state where the first far gear is selected, as is clear from Table 1 above. . Thus, the driver can start the vehicle at the first distance by depressing the accelerator pedal. After that, when the vehicle is sufficiently accelerated, the shift determination circuit 3
5 determines whether the throttle related signal TH or the vehicle signal V or both signals have entered the 2nd speed range by comparison with the 1-2 shift pattern stored therein;
The NAND gate 42 is switched to output an H level signal via the circuit 40.

On the other hand, since the switch 44 is open while driving in the D range, the shift determination circuit 37 is connected to the NAND signal via the circuit 46.
An H level signal is supplied to the gate. Therefore, N.A.
The ND gate 42 is switched to output an L level signal to the 1-2 shift solenoid 24, and the solenoid is switched to O.
Make it FF. By the way, since the signal from the shift determining circuit 36 remains at the L level, the NAND gate 43 continues to output an H level signal to the 2-3 shift solenoid 25, and this solenoid remains ON. Therefore, the automatic transmission selects the second farthest gear by turning both solenoids 24 and 25 OFF and ON, as is clear from Table 1 above.
An upshift from the first far gear to the second gear is performed. As the vehicle accelerates further, the shift determination circuit 36 also
By comparing this with the 2-3 shift pattern stored in this, it is determined that the throttle relation signal TH and the vehicle distance signal V, or both, have entered the 3-way range, and the H signal is sent to the NAND gate 43 via the circuit 41. Switch to output a level signal.

On the other hand, since the switch 45 is open while driving in the D range, the shift determination circuit 38 is connected to the NAND signal via the circuit 47.
An H level signal is supplied to the gate 43. Also, during this acceleration, the driver continues to press the accelerator pedal 28 (see FIG. 2), and the idle switch 29 is opened, and an H level signal is sent to the set input terminal S of the flip-flop circuit 56.
The flip-flop circuit 56 inputs an H level signal to the NANTD gate 43 from the output terminal Q. Therefore, since H level signals are input to all input terminals of the NAND gate 43, the NAND gate 43 is switched to supply an L level signal to the 2-3 shift solenoid 25, turning this solenoid OFF. By the way, NAN
The input signal of the D gate 42 remains unchanged even after the shift up to the second far position, and the 1-2 shift solenoid 24 remains OFF even after the shift up. Therefore, by turning off both solenoids 24 and 25, the automatic transmission selects the third far gear stage as shown in Table 1 above, and a shift-up from the second far to the third far gear is performed. When the manual valve is set to the 2 far fixed range, the switch 45 closes and the shift determination circuit 38 is activated, and the switches 39 and 44 are opened and the shift determination circuits 35 to 37 are inactivated. 37 are inactive, so they supply H level signals to the input terminals of the corresponding NAND gates 42 and 43 via circuits 40, 41 and 46, respectively.Also, when these two far fixed ranges are selected, When the driver intentionally uses engine braking,
Since the vehicle is rarely in an acceleration state, the comparator 51 determines G or GM and supplies an H level signal to the NOR gate 53, which outputs an L level signal to the reset input terminal R of the flip-flop circuit 56. A signal is input to the flip-flop circuit 56 from the output terminal Q to the NAND gate 4.
3 to perform an operation of continuously outputting a daily level signal. Furthermore, even if the vehicle were to accelerate,
This state occurs only when the driver depresses the accelerator pedal greatly. In this case, when the idle switch 29 is turned OFF, an H level signal is input to the NOR gate 53, and in any case, the flip-flop circuit 56 outputs a NAND signal from the output terminal Q. An H level signal is supplied to the gate 43. Then, when the manual valve is set to the 2nd speed fixed range as described above, if the vehicle speed signal V is greater than the vehicle speed setting stored in the shift determination circuit 38, the shift determination circuit 38 outputs a signal to the NAND gate 43 via the circuit 47. Provides H-bell signal. Therefore, in this case, the NAND gates 42 and 43 are all input with daily level signals, and each outputs an L level signal to turn off the 1-2 shift solenoid 24 and the 2-3 shift solenoid 25. Therefore, the automatic transmission is 2
As is clear from Table 1, engine overrun can be prevented when the third gear is selected in the fixed speed range and switched to the second fixed range when the vehicle is high. However, in the same state, if the vehicle speed is lower than the set vehicle distance stored in the shift determination circuit 38, the shift determination circuit 38 compares the set vehicle distance with the vehicle distance signal V and outputs an L level to the NAND gate 43 via the circuit 47. This signal is supplied to the NAND gate to output an H level signal, and the 2-3 shift solenoid 2
5 is turned ON, the automatic transmission can be fixed at the second far gear as is clear from Table 1 above, in addition to the 1-2 shift solenoid 24 being turned OFF as described above. .

When the manual valve of the automatic transmission is set to the 1st speed fixed range, the switch 44 closes and the gear change determination circuit 37 is activated, and the switches 39 and 45 open and the gear change determination circuit 35,
36 and 38 are made inactive.

At this time, since the speed change determining circuits 36, 36, and 38 are inactive, the corresponding NAND
An H level signal is supplied to the input terminals of gates 42 and 43. Also, at this time, the flip-flop circuit 56 supplies an H level signal from the output terminal Q to the NAND gate 43 for the same reason as explained when the second speed fixed range is selected. At this time, the shift determining circuit 37 inputs an H level signal to the NAND gate 42 via the circuit 46 if the vehicle speed signal V is greater than the vehicle distance setting stored therein. Therefore, in this case, the NAND gates 42 and 43 are all input with daily level signals, and each outputs an L level signal to turn off the 1-2 shift solenoid 24 and the 2-3 shift solenoid 25. Therefore, the automatic transmission selects the second far gear stage even though it is in the first speed fixed range, as shown in Table 1 above, and can prevent engine overrun when switching to the first far fixed range at high vehicle speeds. However, in the same state, if the vehicle speed is lower than the set vehicle speed stored in the shift determination circuit 37, the shift determination circuit 37 compares the set vehicle distance with the vehicle distance signal V and outputs the NAN signal via the circuit 46.
An L level signal is supplied to the D gate 42, and this NAND
By outputting an H level signal to the gate and turning on the 1-2 shift solenoid 24, the automatic transmission is turned off as described above, and from Table 1 above, the 2-3 shift solenoid 25 is turned OFF. As is clear, it can be fixed at the first far gear.

Next, the control mode of the engine brake will be explained.

While the vehicle is running in the third range with the manual valve of the automatic transmission in the D range, the vehicle shifts to downhill running, and the driver takes his foot off the accelerator pedal 28 (see FIG. 2) and presses the brake pedal 30. (See FIG. 2), if the vehicle receives acceleration due to a slope that requires engine braking, the acceleration signal G becomes larger than the set acceleration signal GH.

Therefore, the comparator 51 inputs an L level signal (high acceleration determination signal) to the NOR gate 53. In this driving state, the accelerator pedal is released and the brake pedal is depressed as described above, so both the idle switch 29 and the brake switch 31 are turned on. Idle switch 2
9 is turned on, the timer circuit 50 operates, and during the set time, it continues to supply H level signals to the corresponding input terminals of the NOR gate 53 and the set input terminal of the flip-flop circuit 56, and the 2-3 shift solenoid 25
OFF and the third farthest gear remains selected, but after the set time has elapsed, the timer circuit 50 supplies an L level signal (accelerator pedal release signal) to both terminals. On the other hand, when the brake switch 31 is turned ON, an L level signal (brake pedal depression signal) is input to the remaining input terminal of the NOR gate 53, and an H level signal is input to the reset input terminal R of the flip-flop circuit 56. Supplies a level signal (engine brake command).
Therefore, the flip-flop circuit 56 is
An L level signal is supplied to the AND gate 43. As a result, the NAND gate 43 supplies an H level signal to the 2-3 shift solenoid 25, which had been in the OFF state while driving in the 3rd gear in the D range, in order to turn on the 2-3 shift solenoid 25. As a result, the automatic transmission is automatically downshifted from the selected gear position 3rd far to the low speed 2nd far, and engine braking can be applied appropriately while remaining in the D range. Even if the driver takes his foot off the brake pedal, the idle switch 29 is turned off by pressing the accelerator pedal.
This will continue unless it becomes FF.

That is, in this case, when the idle switch 29 is turned off, an H level signal passes through the timer circuit 50 and is output to the NOR gate 5.
3 and the set input terminal S of the flip-flop circuit 56. In this case, since the timer circuit 50 does not operate as described above, this H level signal is supplied to the corresponding terminal at the same time as the idle switch 29 is turned off. At this time, the flip-flop circuit 56
is switched to output an H level signal from the output terminal Q to the NAND gate 43, and as is clear from the above, this NAND gate continues to receive the H level signal from the speed change determining circuits 36 and 38. Correspondingly, an L level signal is input to the 2-3 shift solenoid 25 to turn this solenoid OFF. Therefore, since the 1-2 shift solenoid 24 continues to be OFF during this time, the automatic transmission selects the third gear,
Engine brake can be automatically released. Note that when releasing the engine brake, the timer circuit 50 supplies the H level signal generated when the idle switch 29 is turned off to the corresponding terminal without any delay, as described above, so that the engine brake is released at the same time as the accelerator pedal is depressed. An upshift to third gear is performed, allowing smooth acceleration. In this way, since the automatic transmission of the present invention has its electronic control section configured as described above, it automatically changes from the third range to the second range even when driving in the third range when the D range is set as explained above.
It is possible to downshift far to apply engine braking, and this engine braking is applied only when it is really necessary, that is, when the driver takes his foot off the accelerator pedal and depresses the brake pedal, and when the vehicle is driving downhill. Since it is applied only when the acceleration received exceeds the set value, the driver does not have to downshift unnecessarily every time the brake is applied, which would cause the occupants to feel an unpleasant deceleration, and improve the driving feeling. can be improved.

Furthermore, by installing the timer 50, it is possible to delay the downshift for engine braking by the set time. For example, when driving on a flat road, immediately after accelerating suddenly, you take your foot off the accelerator pedal and press the brake pedal. Even if the vehicle acceleration exceeds the set acceleration due to sudden acceleration during this braking operation, as in the case of a brake operation, unnecessary downshifts will not be performed while driving on flat ground.
It is possible to completely prevent the driving feeling from becoming worse. Furthermore, once the above-mentioned downshift is performed, engine braking can be obtained as long as necessary by holding the second shift until the driver depresses the accelerator pedal in order to accelerate the vehicle; When the engine brake is no longer required by pressing the button, the second speed is immediately released, and the speed change determining circuits 35 and 36 automatically shift up to, for example, the third speed, thereby allowing normal automatic speed change driving. FIG. 4 shows a modification of the acceleration determining means in FIG. 3, and in this example, two acceleration setting circuits 49 are used.
a, 49b are provided, and vehicle far range discrimination circuits 57 and 58 are provided so that these acceleration setting circuits can be used properly for each vehicle far range. The far-vehicle area discrimination circuits 57 and 58 include comparators 59, 60, 61, and 62 to which signals from the far-vehicle sensor 26 are input, and AND gates 63 and 64. In the low vehicle speed range, the comparator 59 outputs an H level signal above the lower limit value, the comparator 60 outputs an H level signal above the upper limit value, and the AND gate 63 outputs an H level signal. , the vehicle far range discrimination circuit 57 discriminates the low vehicle far range and transmits the shift determination circuit 49a.
Activate. On the other hand, in the high vehicle far range, the vehicle far discrimination circuit 58 discriminates the high vehicle far range by the simultaneous actions of the comparators 61, 62 and the AND gate 64, and operates the acceleration setting circuit 49b. Therefore, the acceleration setting circuits 49a and 49b are used for low vehicle speed ranges and high vehicle distance ranges, and the setting acceleration signals GH' and GH'' of these acceleration setting circuits 49a and 49b are set to those suitable for the corresponding vehicle long range ranges. When the acceleration setting circuit 49a is operated at a low vehicle speed, the set acceleration signal GH' is sent to the comparator 51, and when the acceleration setting circuit 49b is operated at a high vehicle speed, the set acceleration signal GH'' is sent to the comparator 51. The signal is selectively input to the comparator 51. According to the electronic control unit of this example with such a configuration, engine braking can be applied as desired in any driving range, for example, even under conditions that require engine braking, such as when driving downhill on an expressway. , it is possible to detect slight acceleration, downshift accurately, and apply engine braking.

In this case, it is desirable that the set acceleration GH'' in the high vehicle far range be a smaller value than the set acceleration GH' in the low vehicle far range. By changing the number and characteristics of 49b, it is possible to freely change the downshift timing and freely obtain engine braking characteristics that best suit the vehicle.Furthermore,
According to the present invention, the embodiment illustrated in FIG. 4 is configured as a digital circuit, and instead of the acceleration setting circuits 49a and 49b, setting values are stored in a ROM (Read Only Memory), and settings corresponding to the distant area of each vehicle are set. It is clear from the above-mentioned gist of the present invention that it is possible to extract and compare values. It goes without saying that in the configuration of this example as well, the same effect as in the above-mentioned example can be obtained by simply changing the set acceleration for each distance region of the vehicle, and the desired effect can be achieved. stomach.

[Brief explanation of drawings]

Fig. 1 is a general gear train schematic diagram of an automatic transmission, Fig. 2 is an electronic control system diagram of the automatic transmission of the present invention, Fig. 3 is a block diagram showing the electronic control section of the automatic transmission of the present invention, and Fig. 4 is a schematic diagram of a general gear train of an automatic transmission. This figure is a block diagram showing a modification of the electronic control section shown in FIG. 3. 1...Input shaft, 2...Torque converter,
3...Intermediate shaft, 4...Front clutch, 5...Rear clutch, 6...Front planetary gear set, 7...Rear planetary gear set,
8, 9... Sun gear, 10, 14... Internal gear, 11... Band brake, 12, 16...
...Pinion, 13, 17...Carrier, 15.
...Output shaft, 18...Low and reverse brake, 19...One-way clutch, 20...Converter cover, 21...Transmission case, 22...Rear extension, 23...Cut back solenoid,
24...1-2 shift solenoid, 25...2-3 shift solenoid, 26...vehicle speed sensor, 27...
... Throttle opening sensor, 28 ... Accelerator pedal, 29 ... Idle switch, 30 ... Brake pedal, 31 ... Brake switch, 32 ... Computer, 33 ... Throttle relationship detection circuit , 34...
...Vehicle speed detection circuit, 35...1-2 for D range
Shift determination circuit, 36...2-3 shift decision circuit for D range, 37...1-2 shift decision circuit for 1st speed fixed range,
38...2 2-3 speed change determination circuit for far fixed range, 3
9...D range switch, 42, 43...NAND gate, 44...1 far range switch, 45...
...2 Far range switch, 48... Acceleration detection circuit, 49, 49a, 49b... Acceleration setting circuit, 5
0...Timer circuit, 51, 59-62...Comparator,
53...NOR Gade, 54, 55...
・Resistance, 56...Flip-flop circuit, 57,5
8...Vehicle long range discrimination circuit, 63, 64...A
ND Gate 8 Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. In an electronically controlled automatic transmission that changes gears by electronically controlling the drive of a shift solenoid, there is an idle detection means for detecting release of the accelerator pedal, and an accelerator pedal release signal from the idle detection means for a set time. a timer that outputs an output for the first time after the brake operation is completed, a brake operation detection means that detects when the brake pedal is depressed, an acceleration determination means that detects when the acceleration of the vehicle exceeds a set value, and the timer, the brake operation detection means, and the acceleration determination means. and engine brake command means for issuing an engine brake command when an accelerator pedal release signal, a brake pedal depression signal, and a high acceleration determination signal are all received, and the engine brake command drives the shift solenoid to shift from the selected gear. An electronically controlled automatic transmission characterized by being configured to automatically downshift to a low gear.