JP3887917B2 - Control device for automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for an automatic transmission configured to determine a gear position from a throttle opening and a vehicle speed.
[0002]
[Prior art]
In a control device for an automatic transmission for a vehicle, generally, a shift map is prepared in advance, and when traveling, the shift map is searched from the throttle opening and the vehicle speed to determine the shift stage.
By the way, for example, if you are approaching a curve while driving on an uphill road at the 3rd speed, take your foot off the accelerator pedal before entering the curve, enter the curve in a decelerating state, and then depress the accelerator pedal near the exit of the curve. The operation of accelerating at is generally performed.
[0003]
In such a case, in the shift speed determination method described above, when the foot is released from the accelerator pedal, the throttle opening becomes smaller and passes through the upshift line from the third speed to the fourth speed. Next, when the accelerator is depressed, the throttle opening increases and passes through the downshift line from the 4th speed to the 3rd speed, causing a downshift to the 3rd speed. To do.
[0004]
As described above, in the conventional shift speed determination method, a busy shift in which up-shifting and down-shifting are performed in response to the return and depression of the accelerator pedal is likely to occur, and a sense of discomfort may be felt and drivability is not good.
[0005]
As a technique for solving the problem of busy shift, there is a technique disclosed in Japanese Patent Laid-Open No. 4-36662. This is because when an operation that suddenly decreases the throttle opening (such as an operation that removes the foot from the accelerator pedal) is performed, the gear position is changed using a predetermined alternative opening instead of the actual throttle opening. Is to control. Therefore, as shown in FIG. 13, by setting the alternative opening larger than the actual throttle opening, it is possible to avoid the up-shifting when an operation for suddenly reducing the throttle opening is performed. . In FIG. 13, Su represents a shift-up line from the third speed to the fourth speed, and Sd represents a shift-down line from the fourth speed to the third speed.
[0006]
Then, by changing the actual throttle opening to the gear position using the alternative opening, the period until the actual throttle opening exceeds the alternative opening is used, so that the throttle is suddenly closed. When the throttle is opened again for acceleration, shift control that meets the driver's request is performed.
[0007]
[Problems to be solved by the invention]
However, in the technique of the above publication, the period for determining the gear position using the alternative opening instead of the actual throttle opening is the period until the actual throttle opening exceeds the alternative opening. If you want to drive up by aggressively shifting up by releasing your foot and accelerating at the shifted gear, it takes a long time to shift up, resulting in poor responsiveness .
[0008]
As an example of a driving mode in which the responsiveness of the shift is a problem, there is an economy (high fuel consumption) driving in an urban area. For example, when starting a vehicle that has stopped, the accelerator pedal is depressed to accelerate, and accordingly, the gear position is shifted up from the first speed to the second speed, and from the second speed to the third speed. Then, when the vehicle speed reaches a certain level at the third speed, the foot is lifted from the accelerator pedal, and the operation is actively performed over the upshift line from the third speed to the fourth speed to shift up to the fourth speed. Thereafter, if the vehicle is gradually accelerated at the fourth speed, the travel distance per liter becomes longer, resulting in an economy operation.
[0009]
However, in the technique of the above publication, when the foot is released from the accelerator pedal at time T1 in FIG. 13, the alternative opening is adopted from that time. No matter how much the throttle pedal is depressed so that the throttle opening exceeds the alternative opening (see the broken line A in FIG. 13) until the time T2 when the upshift line to the 4th speed is exceeded, the 4th speed is shifted up. First, when the accelerator pedal is depressed after the time T2 so that the actual slot opening exceeds the alternative opening, the shift from the third speed to the fourth speed is performed. Therefore, if T time does not elapse after the accelerator pedal is returned, it is not possible to shift up to the fourth speed, it takes a long time to shift up, the accelerator pedal is returned, and then the accelerator pedal is depressed immediately to accelerate. However, this is not possible, but the problem is that it is inferior in responsiveness.
[0010]
The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the problem of busy shift and to improve responsiveness to actively shifting to a predetermined gear position. It is in providing the control apparatus of an automatic transmission.
[0011]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention
  A torque converter connected to the output shaft of the engine;
  A gear transmission mechanism connected to the output side of the torque converter and having a plurality of power transmission paths;
  Road surface gradient detecting means for detecting the gradient of the traveling road;
  Control means for determining a gear position from the throttle opening and the vehicle speed and switching the power transmission path of the gear transmission mechanism to the determined gear position;
  The control means includesWhen it is detected that the road surface gradient detecting means is traveling on an uphill road, the throttle has changed in the closing direction at a change rate exceeding a predetermined value until the throttle becomes less than a predetermined opening,The throttle operation state is in the predetermined return stateIt was judged thatWhen to the predetermined gearShift upIs adopted. (Claim 1).
[0012]
  According to the above configuration,When the control means changes in the closing direction at a change rate exceeding a predetermined value until the throttle becomes less than the predetermined opening,The throttle operation state is in the predetermined return stateIt is judged that. Then, when the vehicle is traveling on an uphill road, if the operation of returning the accelerator pedal is performed in a certain state, the throttle operation state is determined to be the predetermined return state, and a predetermined gear position, for example, from the third speed to the fourth speed is determined. Even if the upshift line is exceeded, the upshift to the fourth speed is prohibited.
  If you are not driving uphill,Prohibition of upshifting to a predetermined gear position, for example, 4th speed is not performed, and aggressively moving to 4th speed by returning the accelerator pedalShift upCan be performed.
[0017]
  Furthermore, in the present invention, a brake operation detection means is provided,
  The control means detects when the brake operation detecting means detects a brake operation within a predetermined time after detecting that the throttle operation state is in a predetermined return state.Shift upIt is possible to adopt a configuration that executes control for prohibiting2).
[0018]
  When configured in this way,When driving uphill,Even if the throttle opening is less than the predetermined opening after the foot is released from the throttle operating state, only when the brake operation is performed within the predetermined time,Shift upIs prohibited. Therefore, if the brake operation is not performed,Shift upIf a brake operation is performed, a predetermined gear positionShift upIs prohibited.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, an engine 1 mounted on a vehicle is connected to drive wheels 4 via an automatic transmission 2 and a differential gear 3.
The intake pipe 5 for sending air into the cylinder of the engine 1 is provided with an air cleaner, a throttle valve 6, a fuel supply device 7 for supplying fuel to the air sent into the cylinder of the engine 1, and the like. ing.
[0020]
The throttle valve 6 is connected to the accelerator pedal 8 via a wire 9 and opens and closes according to the depression amount of the accelerator pedal 8. The throttle valve 6 may be replaced with an electronically controlled throttle that detects the depression amount of the accelerator pedal 8 and controls the air flow rate.
[0021]
The engine 1 is controlled by an engine control computer (not shown) as engine control means. The engine control computer includes a throttle opening degree sensor 10 as a throttle opening degree detecting means for detecting the opening degree of the throttle valve 6, an intake air amount sensor 11 for detecting the intake air amount of the intake pipe 5, and an output shaft of the engine 1. An engine speed sensor 13 as an engine speed detecting means for detecting the speed of a certain crankshaft 12, and a transmission output speed sensor as a transmission output speed detecting means for detecting the speed of the output shaft 14 of the automatic transmission 2 Various signals from 15 are input. Since the vehicle speed is detected based on various signals from the transmission output shaft rotation sensor 15, the sensor functions as a vehicle speed sensor. The engine control computer determines the fuel injection amount based on these input signals to drive the fuel injection device 7 and outputs an ignition signal to operate an ignition device (not shown). The engine 1 is controlled so that fuel supply and combustion are performed in accordance with the rotation.
[0022]
The automatic transmission 2 includes a torque converter 16 and a gear transmission mechanism (hereinafter simply referred to as a transmission mechanism) 17. As is well known, the torque converter 16 includes an input-side pump impeller 18 connected to the crankshaft 12 of the engine 1, an output-side turbine impeller 19, and a stator impeller 20 between the two impellers 18 and 19. It has. A shaft (hereinafter referred to as a turbine shaft) 21 of the turbine impeller 20 that is an output shaft of the torque converter 16 is connected to an input shaft of the transmission mechanism 17.
[0023]
The torque converter 16 includes a lockup clutch 22. When hydraulic oil is supplied to an actuator 24 from a control valve 23 as an oil passage control element, the lock-up clutch 22 frictionally engages the turbine shaft 21 on the pump impeller 18 side that is the input side and The crankshaft 12 and the turbine shaft 21 are directly connected. At this time, the frictional engagement strength of the lockup clutch 22 with respect to the pump impeller 18 side can be adjusted by changing the pressure of hydraulic oil supplied to the actuator 24.
[0024]
The transmission mechanism 17 includes, for example, a plurality of gear trains of four forward stages and one reverse stage as a plurality of power transmission paths. Then, the rotation given to the input shaft from the torque converter 16 is increased / decreased according to the selected gear stage and transmitted to the output shaft 14, and further from the output shaft 14 to the drive wheel 4 via the differential gear 3. Reach and drive the car.
[0025]
Although not shown, the speed change mechanism 17 is provided with various friction engagement elements such as a friction clutch and a friction brake that determine a power transmission path (speed stage). As is well known, these friction engagement elements are fastened and released by an actuator driven by supply of hydraulic oil. Supply of hydraulic oil to the actuator of each friction engagement element is controlled as a hydraulic control element. This is done by valves 25 and 26. At this time, by changing the opening degree of the control valves 25 and 26, the supply amount of hydraulic oil to the actuator can be adjusted to adjust the engagement / release speed of the friction engagement element. Further, in order to change the pressure of the hydraulic oil, a control valve 27 different from the control valves 25 and 26 is provided, thereby changing the pressure of the hydraulic oil supplied to the actuator in accordance with the traveling load or the like. The fastening strength of the frictional engagement element can be adjusted.
[0026]
Here, the hydraulic oil supplied to the actuator of each of the friction engagement elements described above is obtained by filtering the lubricating oil stored in the oil pan of the transmission mechanism 17 with a filter. The hydraulic oil is supplied to the control valves 23 and 25 to 27 by a pump (not shown).
[0027]
The control valves 23 and 25 to 27 of the automatic transmission 2 are controlled by a shift control computer 28 as control means. The shift control computer 28 is a CPU 29, an operation program to be executed by the CPU 29, various maps such as a shift map to be described later, a ROM 30 in which data is stored, and various data for temporarily storing data during calculation. It comprises a RAM 31, an input circuit 32, an output circuit 33, and the like.
[0028]
In addition to the throttle opening sensor 10, the engine rotation sensor 13, and the transmission output rotation sensor 15, the input circuit 32 of the shift control computer 28 includes the rotation speed of the turbine shaft 21 that is the output shaft of the torque converter 16. A turbine rotation sensor 34 as a torque converter output rotation speed detection means to detect, an oil temperature sensor 35 to detect the oil temperature in the oil pan of the transmission mechanism 17, and a brake to detect that the brake has been operated by depressing the brake pedal 36. A signal from a brake sensor 37 as an operation detecting means is input. The CPU 29 is configured to execute arithmetic processing based on these various input signals and operation programs, and to control the control valves 23 and 25 to 27 via the output circuit 33 to switch the gear position. Yes.
[0029]
Next, operation | movement of this control apparatus is demonstrated using the flowchart of FIGS.
When the ignition key of the vehicle is operated and the engine 1 is started, the CPU 29 of the shift control computer 28 starts to operate. First, variables are initialized in step S1 of the main routine shown in FIG. Thereafter, the steps S2 to S7 are repeatedly executed every predetermined time. The variable is a variable for determining the hydraulic pressure to be supplied to the actuator 24 of the lockup clutch 22, a variable for determining the gear position of the transmission mechanism 17, and the like, and by initialization of the variable in step S1, the lockup clutch 22 is the release, and the first speed is selected as the gear position of the speed change mechanism 17.
[0030]
After the variable initialization, the CPU 29 inputs detection signals from the various sensors 10, 13, 15, 34, 35, and 37 in the next step S2, stores them in the RAM 31, and proceeds to step S3. A target gear position determining operation is executed. This target gear position determination routine is shown as a subroutine in FIG. 3. When the CPU 29 enters this target gear position determination routine, first, in step SA1, the CPU 29 calculates from the detection signal of the transmission output rotation sensor 15. Using the obtained vehicle speed and the throttle opening obtained from the detection signal of the throttle opening sensor 10, it is determined which gear range the current operating state falls in the shift map of FIG. To decide.
[0031]
Incidentally, the vehicle speed can be obtained by multiplying the output rotational speed of the speed change mechanism 17 obtained from the transmission output rotation sensor 15 by the speed ratio of the differential gear 3, the diameter of the drive wheel 4, and the circumferential ratio.
In the shift map of FIG. 9, the upshift is a solid line in the shift from the nth speed to the (n + 1) th speed (shift up) and the shift from the mth speed to the (m−1) th speed (shift down). The downshift is indicated by a broken line, and the judgment line between the two is shifted to avoid a busy shift near the shift point.
[0032]
Next, the CPU 29 executes an upshift flag changing routine in step SA2. This routine is shown in FIG. 4. First, in step SB1, it is determined whether or not the target shift speed exceeds the current shift speed. If the target shift speed exceeds the current shift speed, “YES” is determined in the step SB1, and the upshift flag is turned on in the next step SB2 to return. On the contrary, if both are the same gear stage or the target gear stage is lower, “NO” is determined in the step SB1, and the upshift flag is turned off in the next step SB3, and the process returns.
[0033]
When the execution of the upshift flag change routine is completed, the CPU 29 enters the throttle change flag change routine of step SA3. The contents of this routine are shown in FIG. 5. First, in step SC1, the CPU 29 changes the change rate of the throttle opening at -α, that is, changes at a change rate exceeding the predetermined value α in the direction in which the opening becomes smaller. Judge whether or not. If “YES” in the step SC1, the process proceeds to the next step SC2, where the throttle change flag is set to “2” and the process returns.
[0034]
If the throttle opening does not change at a rate of change exceeding α in the direction of decreasing, “NO” is determined in step SC1, and the rate of change of the throttle opening exceeds “0” in the next step SC3. That is, it is determined whether the throttle opening is changing in the opening direction. If the throttle opening has changed in the opening direction, “YES” is determined in the step SC3, the process proceeds to a step SC4, the throttle change flag is set to “1”, and the process returns.
[0035]
Further, if the throttle opening is not changing in the opening direction (slot opening is constant), “NO” is set in step SC3, the slot change flag is set to “0” in the next step SC5, and the process returns. .
[0036]
When the throttle change flag change routine is completed, the CPU 29 next executes a throttle off flag change routine in step SA4. The routine is shown in FIG. 6, and the CPU 29 first determines in step SD1 whether or not the throttle opening is less than β. Here, the throttle opening β is set to an opening slightly larger than the opening 0.
[0037]
When the throttle opening is less than β, the CPU 29 determines “YES” in step SD1, turns on the throttle off flag in the next step SD2, and returns. When the throttle opening is equal to or larger than β, “NO” is determined in step SD1, the throttle off flag is turned off in the next step SD3, and the process returns.
[0038]
Next, the CPU 29 executes a control mode change routine of step SA5. This control mode determination is performed by applying various flag states to the control mode map shown in FIG. In this control mode map, the upshift prohibition flag uses the flag state set in the upshift prohibition flag change routine in step SA6 when the previous target shift speed determination subroutine of FIG. 3 was executed. The on / off state of the flag set in the previous upshift prohibition flag changing routine is changed when step SA6 is executed in the current target gear position determining subroutine.
[0039]
In this control mode determination, for example, if the upshift flag is on, the upshift prohibition flag is off, the throttle change flag is “2”, and the throttle off flag is on, the control mode is “1”. If the upshift flag is on, the upshift prohibition flag is on, the throttle change flag is “1”, and the throttle off flag is off, the control mode is “2”.
[0040]
When the control mode determination is completed, the CPU 29 executes an upshift prohibition flag changing routine in step SA6. This upshift prohibition flag changing routine is shown in FIG. 7. When the routine is entered, the CPU 29 first determines whether or not the control mode determined in step SA5 in step SE1 is “1”. . When the control mode is “1”, “YES” is determined in the step SE1, the upshift prohibition flag is turned on in the next step SE2, and the process returns.
[0041]
If the control mode is other than “1”, “NO” is determined in step SE1, and it is further determined in step SE2 whether the control mode is any one of “0”, “3”, and “4”. To do. If the control mode is any of “0”, “3” and “4”, “YES” is set in step SE3, the upshift prohibition flag is turned off in step SE4, and “0”, “3” and “4” are set. Otherwise, it becomes “NO” in step SE3, and the process returns with the upshift prohibition flag left as it is.
[0042]
When the upshift prohibition flag changing routine is completed, the CPU 29 executes a final target gear position determining routine in step SA7. This final target gear position determination routine is shown in FIG. 8. When the routine starts, the CPU 29 first determines whether the control mode determined in step SA5 is “1” or “2” in step SF1. Judge whether or not. When the control mode is “1” or “2”, “YES” is determined in step SF1, and the final target shift speed is determined as the current shift speed in the next step SF2, and the process returns. If the control mode is other than “1” and “2”, “NO” is determined in step SF1, and the final target shift speed is determined to be the target shift speed determined in step SA1 in the next step SF3. Returns.
[0043]
When the final target shift speed is determined as described above, the CPU 29 returns to the main routine of FIG. 2, and the oil path for switching the shift speed to the determined final target shift speed, in other words, the control. The on / off states of the valves 25 and 26 are determined (step S4). Next, the CPU 29 determines the hydraulic pressure to be supplied to the switching oil passage through the control valves 25 and 26 (step S5), and further locks for controlling the hydraulic pressure supplied to the actuator 24 of the lockup clutch 22 through the control valve 23. The up control amount is determined (step S6), and then the control valves 25 and 26 are turned on / off as determined in step S4, and the pressure of the hydraulic oil supplied to the switching oil passage is controlled to be the pressure determined in step S5. In addition to controlling the valve 27, the opening degree of the control valve 23 is controlled so that hydraulic oil having a pressure corresponding to the control amount determined in step S6 is supplied to the actuator 24 of the lockup clutch 22 (step S7). ).
[0044]
As a result, the transmission mechanism 17 is switched to the final target shift stage, and the lockup clutch 22 is controlled. Thereafter, the CPU 29 returns to step S2 of the main routine of FIG. 2, and thereafter repeatedly executes the operations of steps S2 to S7 as described above every predetermined short time.
[0045]
In the shift speed determination method as described above, when the vehicle is currently traveling on the uphill road at the third speed and approaches a curve, the throttle valve 6 is operated to be in a predetermined return state before the curve. That is, for example, it is assumed that an operation of releasing the accelerator pedal 8 and returning the throttle opening suddenly to less than β is performed. As shown in FIG. 11, it is assumed that the shift-up line Su from the third speed to the fourth speed of the shift map is exceeded at time t1 during the return operation of the throttle valve 6.
[0046]
Then, the current gear position is the third speed, the target gear position is the fourth speed, the upshift flag is turned on (“YES” in step SB1, step SB2), and the throttle change flag is “2” (“SC” in step SC1. YES ”, step SC2), the throttle-off flag is off (“ NO ”in step SD1, step SD3), and the upshift prohibition flag is currently“ off ”. Therefore, in the control mode change routine of step SA5, By applying the above flag state to the 10 control mode map, the control mode is determined to be “2”, and the upshift prohibition flag remains “off” in the upshift prohibition flag change routine of the next step SA6. (“NO” in step SE1, “NO” in step SE3). In step SA7, the final target shift speed is kept at the third speed, which is the current shift speed ("YES" in step SF1, step SF2). This state continues until time t2 when the throttle opening is less than β.
[0047]
When the throttle opening is less than β at time t2, the throttle-off flag is changed to “ON” (“YES” in step SD1, step SD2). Therefore, at time t2, the upshift flag is on, the upshift prohibition flag is “on”, the throttle change flag is “2”, and the throttle off flag is on. Therefore, in the control mode change routine of step SA5, the control mode Is determined to be “1”, and the upshift prohibition flag is turned “ON” in the next upshift prohibition flag change routine in step SA6 (“YES” in step SE1, step SE2). In step SA7, the final target shift speed is kept at the third speed, which is the current shift speed ("YES" in step SF1, step SF2).
[0048]
Thereafter, when the throttle opening is kept at a constant opening less than β (for example, when the foot is released from the accelerator pedal 8), the throttle change flag is “0” (“NO” in step SC1 and “NO” in step SC3. NO ", step Sc5), so the upshift flag is on, the upshift prohibition flag is" on ", the throttle change flag is" 0 ", and the throttle off flag is on, so in the control mode change routine of step SA5 Therefore, the control mode is determined to be “2”, and therefore the shift speed is maintained at the third speed, which is the current shift speed.
[0049]
Depress the accelerator pedal 8 to escape from the curve. As a result of this depression, it is assumed that the throttle opening becomes equal to or greater than β at time t3 in FIG. Then, the throttle change flag is changed to “1” (“NO” in step SC1, “YES” in step SC3, step SC4), and the throttle off flag is changed to OFF (“NO” in step SD1), step SD3). For this reason, in the control mode change routine of step SA5, the control mode is determined to be “2”, and the shift speed is maintained at the third speed, which is the current shift speed, as described above.
[0050]
Then, since the upshift line from the third speed to the fourth speed passes to the third speed side at time t4 in FIG. 11 (the current shift speed and the target shift speed are the same), the upshift flag is turned off. Therefore, regardless of the other flag states, the control mode is set to “3” and the shift speed remains at the third speed, which is the current speed change stage. Retained.
[0051]
As described above, when the throttle operation state is a predetermined return state, that is, when an operation that decreases rapidly until the throttle opening becomes less than β, a gear shift higher than the gear stage at the time of starting the operation is performed. Since shifting to the gear is prohibited, it is possible to prevent a busy shift when the foot is released from the accelerator pedal 8 while traveling on an uphill road.
[0052]
On the other hand, in order to start a vehicle that has been stopped while traveling in an urban area, the accelerator pedal is depressed to accelerate, and accordingly, the gear position is changed from the first speed to the second speed, and from the second speed to the third speed. And shift up in order. Then, when the vehicle speed reaches a certain level at the third speed (indicated by ta in FIG. 12), the accelerator is pushed to the extent that the throttle opening exceeds the shift-up line from the third speed to the fourth speed but does not become less than β. Assume that the pedal 8 is returned.
[0053]
Then, when the throttle opening exceeds the shift-up line Su from the third speed to the fourth speed (at time tb in FIG. 12), the current shift speed is the third speed and the target shift speed is the fourth speed. The upshift flag is “on”, the upshift prohibition flag is “off”, the throttle change flag is “2”, the throttle off flag is “off”, and the control mode is “2”. Then, the upshift prohibition flag remains “OFF” (“NO” in step SE1 and “NO” in step SE3), and the final target shift speed is held at the third speed, which is the current shift speed (step SF1). "Yes")
[0054]
Thereafter, when the throttle opening is kept constant at the time indicated by tc in FIG. 12 or the throttle opening is opened, the throttle change flag becomes “0” or “1” (“NO” in step SC1) "YES" in step SC3, "NO" in step SC4 or step SC1, "NO" in step SC3, step SC4). Therefore, the upshift flag remains on, the upshift prohibition flag remains off, the throttle change flag is “0” or “1”, and the throttle off flag is off, so the control mode is “0”.
[0055]
Therefore, the upshift flag remains on, and the final target shift speed is determined to be the fourth speed that is the target shift speed (“NO” in step SF1, step SF3), and the shift speed is changed from the third speed to the fourth speed. And shift.
[0056]
As described above, when the throttle operation state is not the predetermined return state, that is, even if an operation for rapidly decreasing the throttle opening is performed, if the opening does not become less than β, the current gear position is increased. When shifting to a shift stage is performed, for example, when an economy operation is performed in an urban area, the shift to the high shift stage side is responded to the operation of releasing the foot from the accelerator pedal 8 (throttle opening decreasing operation). The speed can be changed with good performance.
[0057]
The present invention is not limited to the embodiments described above and shown in the drawings, and can be expanded or changed as follows.
In the present invention, when the throttle operation state is a predetermined return state, the prohibited shift speed may be a shift speed other than the current shift speed. Therefore, for example, when the current state is the second speed, the shift to the first speed may be prohibited, and the shift to the first speed and the third speed may be prohibited.
[0058]
Further, when the throttle operation state is a predetermined return state, the shift speed to be prohibited may be higher than the current shift speed. For example, at the current third speed, the prohibited speeds may be both the third speed and the fourth speed, only the third speed, or only the fourth speed. A configuration may be adopted in which shifting to the fourth speed, which is the highest gear position, is prohibited when the speed is at any one of the speeds.
[0059]
In the present invention, in addition to the throttle operation state being a predetermined return state, when the brake device is being braked (when the brake pedal 36 is depressed), a shift to a predetermined shift stage is prohibited. You may do it. The operation of decreasing the throttle opening while traveling on an uphill road is usually for deceleration and involves a brake operation. In other cases, the majority of operations are based on the intention to change the gear position. In this configuration, it is possible to individually respond to such a request.
[0060]
  In the present invention, a slope estimating means for estimating the slope of the traveling road is provided, and the slope estimating meansThe roadWhen it is detected that the vehicle is traveling, when the throttle operation state is a predetermined return state,Shift upIt can be configured to execute control for prohibiting the above. As gradient estimation means in this case, a gear ratio is calculated from the input rotation speed and the output rotation speed of the torque converter 16, the torque capacity coefficient and the torque ratio of the torque converter 16 are obtained using the gear ratio, and the torque converters are calculated. 16, the transmission torque to the transmission 17 side is obtained from the input rotational speed, the torque capacity coefficient, and the torque ratio. Subsequently, the transmission gear ratio of the current gear stage of the transmission 17, the transmission gear ratio of the differential gear 3, and the diameter of the drive wheel 4 The driving force is obtained from the vehicle speed, the running resistance is obtained from the vehicle speed, the acceleration resistance is obtained from the vehicle weight and the acceleration, and the running load is obtained by subtracting the running resistance and the acceleration resistance from the driving force. It is conceivable to estimate the slope of the road.
[0061]
Further, as another gradient estimation means, an engine rotation sensor detected from a map using the pressure (negative pressure) of the intake pipe 5 of the engine 1 or the intake amount of the engine 1 and the rotation speed or throttle opening of the engine 1 is used. 13 is used to obtain the output torque of the engine 1, and the input torque of the torque converter 16 is obtained from the engine output torque by contrasting the load torque of the alternator and the compressor. The output torque of the torque converter 16 (transmission torque to the transmission 17) is obtained using the characteristic map of FIG. 8, and subsequently, the transmission gear ratio of the current gear stage of the transmission 17 and the transmission gear ratio of the differential gear 3, The driving force is determined from the diameter of the driving wheel 4, the running resistance is determined from the vehicle speed, and the acceleration is performed from the vehicle weight and acceleration. Anti look, and obtains the running load by subtracting the acceleration resistance and the running resistance from the driving force may be configured to estimate the slope of the road from the running load.
[0062]
  The vehicle speed sensor is not limited to the transmission output shaft rotation sensor 15, and may be a sensor that detects the rotation speed of the axle of the drive wheel 4.
  On the uphill road,When the throttle operation state is the predetermined return state,Shift upThe shift speed forbidden may be other than the fourth speed, and may be determined as necessary.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a control device for an automatic transmission for a vehicle according to an embodiment of the present invention.
FIG. 2 is a main flowchart showing the control contents of the control means.
FIG. 3 is a flowchart showing a target gear position determination routine used in the flowchart of FIG. 2;
4 is a flowchart showing an upshift flag change routine used in the flowchart of FIG. 3;
FIG. 5 is a flowchart showing a throttle change flag changing routine used in the flowchart of FIG. 3;
6 is a flowchart showing a throttle flag change routine used in the flowchart of FIG. 3;
7 is a flowchart showing an upshift prohibition flag change routine used in the flowchart of FIG. 3;
FIG. 8 is a flowchart showing a final target gear position determination routine used in the flowchart of FIG. 3;
FIG. 9 is a shift map used in the flowchart of FIG.
FIG. 10 is a control mode map used in the flowchart of FIG.
FIG. 11 is a diagram of change in throttle opening for explaining the operation, part 1
FIG. 12 is a throttle opening change diagram 2 for explaining the operation;
FIG. 13 is a diagram showing a change in throttle opening for explaining a conventional problem.
[Explanation of symbols]
In the figure, 1 is an engine, 2 is an automatic transmission, 3 is a differential gear, 4 is a drive wheel, 6 is a throttle valve, 8 is an accelerator pedal, 10 is a throttle opening sensor, 12 is a crankshaft, and 13 is an engine rotation sensor. , 14 is an output shaft, 15 is a transmission mechanism output rotation sensor, 16 is a torque converter, 17 is a gear transmission mechanism, 18 is a pump impeller, 19 is a turbine impeller, 21 is a turbine shaft (output shaft of the torque converter), 23 , 25 to 27 are control valves, 28 is a shift control computer (control means), and 34 is a turbine rotation sensor.

Claims (2)

A torque converter connected to the output shaft of the engine;
A gear transmission mechanism connected to the output side of the torque converter and having a plurality of power transmission paths;
Road surface gradient detecting means for detecting the gradient of the traveling road;
Control means for determining a gear position from the throttle opening and the vehicle speed and switching the power transmission path of the gear transmission mechanism to the determined gear position;
When the control means detects that the road surface gradient detection means is traveling on an uphill road , the control means has changed in the closing direction at a rate of change exceeding a predetermined value until the throttle becomes less than a predetermined opening degree. Accordingly, when the throttle operating condition is determined to be the predetermined return condition, the control apparatus for an automatic transmission and inhibits the upshift to a predetermined shift stage. Brake operation detection means
The control means prohibits upshifting to the predetermined gear position when the brake operation detecting means detects a brake operation within a predetermined time after determining that the throttle operation state is in the predetermined return state. The control apparatus for an automatic transmission according to claim 1, wherein the control is performed .

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