JPH09210190A - Controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accomplish the suppression of increased load when the load to the differential gear is heavy. SOLUTION: The turbine revolution Trev in the normal travel is shown as curve 24. If one of driven wheels slips, the absolute value of the difference of the revolution of both left and right driven wheels |NR-NL| will be as shown in curve 21 attained to higher revolution in short period of time, to enter in the zone 22 where the load to the differential gear is too heavy. Then by prohibiting shifting up and engaging in second speed, the turbine revolution will be as shown in curve 25, the absolute value of difference |NR-NL| also is prevented from entering in the zone 22, as shown in curve 23. Thereby the damage to the differential gear caused by the heavy load of the differential gear will be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vehicle, and more particularly to a control device for an automatic transmission of an automobile, which is a typical vehicle.

[0002]

2. Description of the Related Art The spread of automatic transmission vehicles (hereinafter referred to as AT vehicles) in automobiles has been remarkable, and due to their comfortable operability, they are being installed in commercial vehicles such as buses and trucks. Particularly in recent years, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-159459, various gear shifting operations can be performed more smoothly than in the past due to the progress of electronic control regarding the running state and the progress of the hydraulic system circuit of the speed change mechanism. AT vehicles are being developed. This technology enables anyone to drive a car relatively easily regardless of the driving environment.

[0003]

However, let us consider a case where the drive wheels of an AT vehicle as described above slip on a bad road such as a snowy road or an unpaved road. At this time, the driving wheels increase their wheel speeds in a short time. Then, as the wheel speed increases, the control device for the automatic transmission sequentially shifts up based on the vehicle speed map stored in advance. For this reason, when only one side of the drive wheels is slipping, the vehicle speeds of the left and right wheels are significantly different, so that the load on the differential gear becomes large, and the good operation of the differential gear cannot be obtained. there is a possibility.

Therefore, an object of the present invention is to provide a control device for an automatic transmission which can suppress an increase in load when the differential gear is heavily loaded.

[0005]

In order to achieve the above object, a control device for an automatic transmission according to the present invention is characterized by the following configuration.

That is, load detecting means for detecting a value related to the load on the differential gear provided between the left and right drive wheels, and a load for suppressing an increase in the load on the differential gear based on the value related to the load. And a suppressing means. This prevents an increase in the load on the differential gear and ensures good operation of the differential gear.

Further preferably, the load detecting means is capable of detecting a difference in rotational speed between the left and right drive wheels, and the load suppressing means has a first predetermined difference in rotational speed between the left and right drive wheels. Is larger than the value of, the increase in the load on the differential gear is suppressed. By detecting the difference between the rotational speeds of the right drive wheel and the left drive wheel and comparing them with the first predetermined value, it is detected that the load on the differential gear is excessive. Accordingly, particularly in the case of a wheel provided with an antilock brake system (hereinafter, ABS), the wheel speed sensor can be shared between the system of the present invention and the ABS, which is advantageous in terms of cost.

Further preferably, the load detecting means is capable of detecting a variation amount of the turbine rotational speed for driving the drive wheels per unit time, and the load suppressing means is capable of detecting the variation amount per unit time. When it is larger than the second predetermined value, an increase in the load on the differential gear is suppressed. By detecting the rate of increase of the turbine speed and comparing it with a second predetermined value, it is possible to detect that the load on the differential gear is excessive, so that a wheel speed sensor is not required, and a turbine speed sensor Since it can be shared with the vehicle speed sensor, it is advantageous in terms of cost.

More preferably, the load suppressing means includes a shift time detecting means for detecting a time required for shifting from a predetermined gear position to a gear position higher than the gear position, and the load suppressing means has the predetermined time. Less than the time of
It is characterized in that an increase in load on the differential gear is suppressed. By detecting the time interval of the gear shifting operation and comparing it with a predetermined time, it is detected that the load on the differential gear is excessive, so that a new sensor is not required, which is advantageous in terms of cost.

More preferably, throttle opening detecting means for detecting a value related to throttle opening, turbine rotational speed detecting means for detecting a value related to turbine rotational speed,
Based on the shift map that determines the shift speed based on the detection results of the throttle opening detection means and the turbine rotation speed detection means, based on the throttle opening detection means and the turbine rotation speed detection means, and the shift map A predetermined time period determining means for determining the predetermined time period. As a result, the predetermined time is appropriately set, and accurate control without erroneous determination can be obtained.

More preferably, the vehicle further comprises a vehicle speed detecting means for detecting a value relating to the vehicle speed, wherein the gear shift time detecting means stores the value relating to the vehicle speed in advance. The measurement of the required time is started when it is larger than the third predetermined value. Thereby, the determination is performed with high accuracy. Furthermore,
Specifically, it comprises a detection means for detecting a value related to the amount of change in vehicle speed per unit time, and starts measuring the required time when the value related to the amount of change is larger than a fourth predetermined value stored in advance. Is characterized by. As a result, it is possible to deal with the case where the drive wheels idle while traveling at a certain vehicle speed.

The suppressing means of the control device for the automatic transmission described above prohibits shifting (shifting up) to a high speed position or shifting (shifting down) to a low speed position by the automatic transmission. The means is released when the vehicle speed of the vehicle reaches 0 or a predetermined vehicle speed stored in advance, or after a predetermined time stored in advance has elapsed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. First, the configuration of the present invention will be briefly described.

FIG. 1 is a block diagram showing the configuration of the present invention. The control device for an automatic transmission according to the present invention first determines the load detected by the negative detection unit for the differential gear by the load determination unit in the subsequent stage, and based on the result of the determination, the negative suppression unit for the differential gear sets the differential. The automatic transmission is shifted so that the load on the gears is suppressed.

Next, an outline of a control device for an automatic transmission mounted on an automobile to which the present invention is applied will be described with reference to FIG.

FIG. 2 is a block diagram of an automatic transmission as an embodiment of the present invention.

In the figure, reference numeral 1 is a control device for an automatic transmission mounted on an automobile. Reference numeral 2 is an inhibitor switch for restricting the position of the select lever by which the driver selects the traveling mode of the AT vehicle. Reference numeral 3 denotes a turbine sensor that detects the rotation speed of the turbine on the output side of the torque converter included in the automatic transmission mechanism (not shown). Reference numeral 4 denotes a throttle sensor that detects the opening degree of the accelerator pedal depressed by the driver. Reference numeral 5 is a sensor for detecting the number of rotations of the right drive wheel in order to calculate the vehicle speed. A sensor 6 detects the number of rotations of the left driving wheel to calculate the vehicle speed.

The control device 1 includes a CPU 1 for controlling gear shifting.
0, a ROM 11 for storing fixed parameters and control programs represented by a shift map, and a RAM 12 used as a temporary storage of variable parameters and a working area of the CPU 10. The CPU 10 receives the detection signal PS of the inhibitor switch 2 and the turbine sensor 3 which are input.
Detection signal Trev of the throttle sensor 4
VO, detection signal NR of right drive wheel rotation speed sensor 5, and detection signal NL of left drive wheel rotation speed sensor 6 and ROM 11
The calculation is performed based on the data and the like, and the control signal SOL is output as the calculation result. By this control signal SOL, the shift solenoid 8 included in the automatic transmission mechanism (not shown) is operated to perform upshift / downshift.

<First Embodiment> Next, with reference to a flow chart, a process for suppressing an increase in the load on the differential gear when the idle wheels of the drive wheels according to the present invention of the automatic transmission having the above-described structure occur will be described. To do.

FIG. 3 is a flow chart showing the flow of processing according to the first embodiment of the present invention.

In the figure, in step S1, the present turbine speed Trev (rpm) and right drive wheel speed NR
(Rpm), gear position DI, and left drive wheel speed NL
(Rpm) is detected and input to the CPU 10, and the vehicle speed VSP (km / km / m) is calculated from the right drive wheel rotation speed NR and the left drive wheel rotation speed NL.
Calculate h). In step S2, the turbine rotation speed Trev is smaller than a predetermined first-speed allowable maximum rotation speed Trev1 stored in advance in the ROM 11, the detection signal PS of the inhibitor switch 2 is the first speed, and the vehicle speed VS.
P is a predetermined speed VSP1 previously stored in the ROM 11
Is less than. If this condition is not satisfied, it can be regarded as not the first speed (high speed or N speed) and the process returns to step S1 to repeat the loop. On the other hand, if the above conditions are satisfied, it is considered that the vehicle is in the first speed and is equal to or lower than the predetermined vehicle speed, and the process proceeds to step S3. In step S3, the counter CNT is reset to 0. Step S4
, The detection signal PS of the inhibitor switch 2 is the first speed, and the turbine rotation speed Trev is the ROM 11 in advance.
It is determined whether or not it is larger than the predetermined shift rotation speed Trev2 stored in (for example, Trev2 is set to 0, and if the turbine rotation speed Trev is not 0, it is determined to start). If this condition is not satisfied, the process returns to step S3 to repeat the loop. On the other hand, if the conditions are satisfied, step S
The process proceeds to step 5 and starts counting by the counter CNT. In step S6, the count value of the counter CNT and the throttle opening TVO1 when the shift signal from the first speed to the second speed is generated.
Is detected and stored in the RAM 12. At this point, the automatic transmission shifts up to the second speed regardless of the processing of this flowchart. In step S7, RO
CNT1 (msec) is calculated from the throttle opening TVO1 by referring to the table stored in M11. This table is shown in FIG.

FIG. 4 is a diagram showing a table stored in advance as the first embodiment of the present invention.

Then, in step S8, step S
CNT stored in 6 is CNT1 calculated in step S7
Determine if smaller. That is, the idling of the drive wheels is detected by detecting whether or not the shift from the first speed to the second speed is performed within a short time that does not occur in normal traveling. If this condition is not satisfied, the process ends because it can be regarded as normal traveling. On the other hand, if the conditions are satisfied, it is determined that the drive wheels are idling, and the process proceeds to step S9. In step S9, the CPU 10 shifts from the second speed to the third speed.
Prohibit shifting from third speed to fourth speed. As a result, further idling of the drive wheels is suppressed, and an increase in the load on the differential gear when only one of the left and right wheels is idling is suppressed. In step S10, the current turbine rotation speed Trev is smaller than the shift rotation speed Trev3 to the predetermined third speed stored in the ROM 11 in advance, or the vehicle speed VSP is the predetermined speed VS stored in the ROM 11 in advance.
It is smaller than P2, or the detection signal PS of the inhibitor switch 2 is in the L range (first speed fixed range), or the vehicle speed VSP.
It is determined whether = 0. If this condition is not satisfied, the process returns to step S9 to repeat the loop. On the other hand, if the conditions are satisfied, the process proceeds to step S11 to release the prohibition of the shift from the second speed to the third speed and from the third speed to the fourth speed, and the process ends.

<First Modification of First Embodiment> The present modification is characterized in that when idle rotation of the drive wheels is detected, the gear is shifted to a lower gear ratio. The description of the same processing as that of the first embodiment is omitted.

FIG. 5 is a flow chart showing the flow of processing as a first modified example of the first embodiment of the present invention.

In the figure, steps S21 to S28
The processing of step S1 to step S8 in FIG.
Is the same as the processing of In step S29, since it is determined in step S28 that idling has occurred, the CPU 10
Prohibits the shift to the high speed stage and shifts down the shift stage DI to 1, that is, the first speed and fixes it. Then, in step S30, as in step S10, the current turbine rotation speed Trev is smaller than the shift rotation speed Trev3 to the predetermined third speed stored in the ROM 11 in advance, or the vehicle speed VSP is stored in the ROM 11 in advance. It is smaller than the speed VSP2, or the detection signal PS of the inhibitor switch 2 is in the L range (first speed fixed range), or the vehicle speed V.
It is determined whether SP = 0. If this condition is not satisfied, the process returns to step S29 to repeat the loop. On the other hand, if the conditions are satisfied, the process proceeds to step S31, the prohibition of shifting to the high speed stage is released, and the process ends.

<Second Modification of First Embodiment> This modification is characterized in that the shift prohibiting process is canceled in time when idling is detected. The description of the same processing as that of the first embodiment is omitted.

FIG. 6 is a flow chart showing the flow of processing as a second modification of the first embodiment of the present invention.

In the figure, steps S41 to S48
The processing of step S1 to step S8 in FIG.
Is the same as the processing of In step S49, shifting from the second speed to the third speed and from the third speed to the fourth speed is prohibited, and
The counter CNTD is reset, and counting is started in step S50. In step S51, the counter C
The NTD stores a predetermined time C stored in the ROM 11 in advance.
It is determined whether it is greater than NT2 or the vehicle speed VSP = 0. If the condition is not satisfied, the loop is repeated to measure the upshift inhibition processing. On the other hand, if the conditions are satisfied, the process proceeds to step S52 and step S1 in FIG.
Similarly to 1, the shift-up prohibition process is canceled and the process ends.

The first embodiment described above realizes the suppression of an increase in the load on the differential gear by lowering or fixing the gear position when the drive wheels run idle. It should be noted that if the gear position DI or the setting of the fixed vehicle speed and the fixed gear position in the drive wheel idling determination process are changed, the present embodiment is limited to the case where the idling is determined when shifting from the first speed to the second speed. It goes without saying that the present invention can be applied to other gear positions without any need. Needless to say, the vehicle speed may be calculated by detecting the turbine speed. Further, the application of the present invention may be applied to railcars.

<Second Embodiment> Next, as a second embodiment, a method of determining that one side of the drive wheel has caused idle rotation and suppressing an increase in the load on the differential gear will be described. In the present embodiment, the difference between the rotations of both drive wheels is detected using the detection signal NR of the right drive wheel rotation speed sensor 5 and the detection signal NL of the left drive wheel rotation speed sensor 6, and the above-described shift-up prohibition process is performed. To do. The process flow of this embodiment will be described with reference to the flowchart. The configuration of the automatic transmission in this case has the same configuration as the block diagram shown in FIG.

FIG. 7 is a flow chart showing the flow of processing according to the second embodiment of the present invention.

In step S101 in the figure, the current detection signal NR of the right drive wheel rotation speed sensor 5 and the current detection signal NL of the left drive wheel rotation speed sensor 6 are input to the CPU 10. In step S102, the absolute value of the difference between the two detected signals input in step S101, that is, the absolute value of the difference between the rotational speeds of the left and right driving wheels is calculated and stored in advance in the ROM1.
It is determined whether or not it is larger than the predetermined value N1 stored in 1. If this condition is not satisfied, it is determined that the vehicle is running normally and the process returns to step S101. On the other hand, when the conditions are satisfied, it is determined that the drive wheel on one side is idling and the load on the differential gear is increasing, and the process proceeds to step S103. In step S103, the upshift is prohibited or the gear position DI is fixed at 2 (second speed fixed range). In step S104, the absolute value of the difference between the rotational speeds of the left and right driving wheels is calculated and is smaller than the predetermined value N2 stored in the ROM 11 in advance, or the L range (1
It is determined whether the fixed speed range) is selected or NR = NS = 0. If this condition is not satisfied, it is determined that the drive wheel on one side is still spinning, and step S10 is performed.
Return to 3. On the other hand, if the conditions are satisfied, step S1
Go to 05. In step S105, the shift-up prohibition process is canceled and the process ends.

<Modification of Second Embodiment> This modification is characterized in that the idling of the drive wheels is detected by the rate of increase in the rotation of the turbine.

FIG. 8 is a flow chart showing the flow of processing as a modification of the second embodiment of the present invention.

In the figure, in step S111, the present turbine rotation speed Trev and turbine rotation increase rate VTr are shown.
ev and the gear position DI are input to the CPU 10. In step S112, the rate of increase in turbine rotation VTr
ev is a function f (DI, Trev) of the gear shift stage DI and the turbine speed Trev stored in the ROM 11 in advance.
It is determined whether it is larger than the first threshold value calculated from If this condition is not satisfied, it is determined that the vehicle is running normally and the process returns to step S111. On the other hand, if the conditions are satisfied, it is determined that one side of the drive wheels is spinning and the load on the differential gear is increasing, and the process proceeds to step S113. In step S113, upshifting is prohibited or the gear position DI is fixed at 2 (second speed fixed range). In step S114, the rate of increase in turbine rotation VTr
ev is a function g (DI, Trev) of the gear position DI and the turbine speed Trev stored in the ROM 11 in advance.
Is smaller than the second threshold value calculated from, or the driver has selected the L range (first speed fixed range),
Alternatively, it is determined whether NR = NS = 0. If this condition is not satisfied, it is determined that the drive wheel on one side is still idling, and the process returns to step S113. on the other hand,
If the conditions are satisfied, it is determined that the vehicle is in a normal traveling state, and the process proceeds to step S115. In step S115, since it is determined in step S114 that the vehicle is in the normal traveling state, the upshift inhibition process is canceled and the process ends.

It should be noted that the first threshold value calculated from the function f (DI, Trev) and the second threshold value calculated from the function g (DI, Trev) so that the processing can be smoothly performed in the actual operation. The relationship with the threshold value is (first threshold)
> (Second threshold value) is preferable. Further, it goes without saying that the rate of increase in turbine rotational speed in the present embodiment can be detected jointly by the rate of increase in wheel speed of the slipping drive wheels, but in that case, wheel-side detection means is required.

The effect of suppressing an increase in the load on the differential gear when the shift-up prohibition process described in the second embodiment is performed will be described with reference to FIG. The first gear ratio is 2.8, the second gear ratio is 1.54, the third gear ratio is 1.00, the fourth gear ratio is 0.7, and the final gear ratio is 4.06.

FIG. 9 is a diagram for explaining the effect of the shift-up prohibition process in each embodiment of the present invention.

In the figure, the horizontal axis represents time (sec), and the vertical axis represents the absolute value of the difference between the rotations of the left and right drive wheels when idling | NR-N.
L│ (rpm) and turbine speed Trev (rpm)
Represents Reference numeral 22 represents a zone in which a large load is applied to the differential gear and good operation may not be obtained. Reference numeral 24 is a curve showing a change in turbine speed during normal running when shifting up from the first speed to the fourth speed. In the conventional case, if the drive wheel spins for some reason, one side of the drive wheel should rotate abnormally high as shown by the curve 21 while shifting up in a short time. The 2nd speed is fixed by the shift-up prohibition process described in the second embodiment.
Therefore, the turbine rotation speed is 25, and the absolute value of the difference between the rotations of the left and right drive wheels can be prevented from entering the zone 22 in which good operation may not be obtained as indicated by 23. Further, as described above, in general, the driver does not depress the accelerator so much that he or she actually draws 25 curves.

In the second embodiment described above, the increase in the load on the differential gear is suppressed by detecting the rotation difference between the left and right drive wheels and fixing the gear position to the second speed. It is needless to say that the invention is not limited to the form, and can be fixed to another gear stage if necessary. Further, similarly to the first embodiment, the gear position may be downshifted.

[0042]

As described above, according to the present invention,
It is possible to provide a control device for an automatic transmission that can suppress an increase in load when the load on the differential gear is large.

[0043]

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a block diagram of an automatic transmission as an embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of processing according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a table stored in advance as the first embodiment of the present invention.

FIG. 5 is a flowchart showing a processing flow as a first modified example of the first embodiment of the present invention.

FIG. 6 is a flowchart showing a flow of processing as a second modified example of the first embodiment of the present invention.

FIG. 7 is a flowchart showing a processing flow as a second embodiment of the present invention.

FIG. 8 is a flowchart showing a processing flow as a modified example of the second exemplary embodiment of the present invention.

FIG. 9 is a diagram illustrating an effect of shift-up prohibition processing according to each embodiment of the present invention.

[Explanation of symbols]

 1 Automatic Transmission Control Device 2 Inhibitor Switch 3 Turbine Sensor 4 Throttle Sensor 5 Right Drive Wheel Rotation Speed Detection Sensor 6 Left Drive Wheel Rotation Speed Detection Sensor 8 Shift Solenoid 10 CPU 11 ROM 12 RAM

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Claims (9)

[Claims] 1. A load detection means for detecting a value related to a load on a differential gear provided between the left and right drive wheels, and a load for suppressing an increase in the load on the differential gear based on the value related to the load. A control device for an automatic transmission, comprising: a suppressing means. 2. The load detecting means is capable of detecting a difference in the rotational speeds of the left and right drive wheels, and the load suppressing means has a first predetermined difference in the rotational speeds of the left and right drive wheels. The control device for an automatic transmission according to claim 1, wherein an increase in load on the differential gear is suppressed when the value is larger than the value. 3. The load detecting means is capable of detecting the amount of change in the turbine rotational speed for driving the drive wheels per unit time, and the load suppressing means is configured to detect the amount of change in the unit time per unit time. The control device for an automatic transmission according to claim 1, wherein an increase in a load on the differential gear is suppressed when the value is larger than a predetermined value of 2. 4. A shift time detecting means for detecting a time required to shift from a predetermined gear position to a gear position higher than the gear position, wherein the load suppressing means has the predetermined time. The control device for an automatic transmission according to claim 1, wherein an increase in a load on the differential gear is suppressed when the time is less than the time. 5. A throttle opening detection means for detecting a value related to throttle opening, a turbine rotation speed detection means for detecting a value related to turbine rotation speed, the throttle opening detection means and the turbine rotation speed detection. A shift map for determining a shift position based on a detection result of the means, a throttle opening detection means, a turbine speed detection means, and a predetermined time determination means for determining the predetermined time based on the shift map. The control device for an automatic transmission according to claim 4, further comprising: 6. A vehicle speed detecting means for detecting a value relating to a vehicle speed is provided, wherein the gear shift time detecting means is such that the gear position is a predetermined gear position stored in advance and the value relating to the vehicle speed is
The control device for an automatic transmission according to claim 4 or 5, wherein the measurement of the required time is started when it is larger than a third predetermined value stored in advance. 7. A detection means for detecting a value related to a change amount of vehicle speed per unit time, wherein the required time is measured when the value related to the change amount is larger than a fourth predetermined value stored in advance. 5. The process according to claim 4, wherein the process is started.
Alternatively, the control device for the automatic transmission according to claim 5. 8. The load suppressing means suppresses an increase in load on the differential gear by prohibiting an upshift, and the load suppressing means suppresses an increase in load on the differential gear.
The control device for the automatic transmission according to claim 1. 9. The automatic transmission according to claim 1, wherein the load suppressing unit suppresses an increase in the load on the differential gear by performing downshifting. Control device.