JP2008115975A - Control device of automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To start inertia phase control in a state of generating a sufficient engaging force by a frictional engaging element, even under a condition of causing reduction in the input shaft rotating speed of a shift gear mechanism during shift control. <P>SOLUTION: A driven state and an undriven state of an engine are determined based on an engine control parameter (such as engine torque or a throttle opening) during the shift control, and the determination of an inertial phase is prohibited by setting an inertial phase determination permitting flag to an off-state at a time t2 when the determination of the engine driving state is switched to the undriven state. The determination of the inertial phase is permitted by setting the inertial phase determination permitting flag to an on-state at a time t3 when a count value of a timer for counting an elapsed time after starting the shift control reaches a predetermined time. Thereafter, a phase is determined whether it is the inertial or a non-inertial phase depending on whether or not an input shaft rotating speed Nt (or the gear ratio) is lower than an inertial phase determining threshold. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automatic transmission control device having a function of determining an inertia phase in which an input shaft rotation speed of a transmission gear mechanism changes in accordance with an engagement operation of a friction engagement element of a transmission gear mechanism of an automatic transmission. It is invention regarding.

  An automatic transmission for an automobile transmits the driving force of an engine to an input shaft of a transmission gear mechanism through a torque converter, shifts the transmission gear mechanism to transmit it to an output shaft, and rotationally drives the drive wheels. ing. Generally, a transmission gear mechanism has a plurality of gears arranged between an input shaft and an output shaft, and a plurality of power transmission paths having different speed ratios are formed between the input shaft and the output shaft. Friction engagement elements such as clutches and brakes are provided inside, and the hydraulic pressure applied to each friction engagement element is individually controlled in response to a gear change request, thereby engaging and releasing each friction engagement element. By selectively switching, the power transmission path between the input and output shafts is switched to switch the gear ratio.

  In such a shift control of an automatic transmission, hydraulic fluid is rapidly applied to the engagement-side friction engagement element until the engagement-side friction engagement element is in a state immediately before the engagement force is generated at the initial stage of the shift control. After controlling the rapid filling phase to be filled, the filling phase is controlled to maintain the hydraulic pressure (standby hydraulic pressure) increased by the rapid filling phase control, and then the torque sharing of each friction engagement element is changed. Through the torque phase control, the process shifts to inertia phase control, which is a stage where the ratio of the rotational speed between the input and output shafts of the transmission gear mechanism (that is, the gear ratio) changes (see FIG. 4). At this time, in the torque phase control, sweep control for increasing the hydraulic pressure in a feed forward manner is executed, and in the subsequent inertia phase control, the hydraulic pressure is feedback controlled based on the input shaft rotation speed of the transmission gear mechanism.

  In this inertia phase, torque (inertia torque) is generated due to a change in inertial force of the rotating system in the transmission gear mechanism, and a shift shock may occur due to a change in output shaft torque due to this inertia torque. Since it is known that the shift shock generated in the inertia phase depends on the change rate of the input shaft rotation speed, the change rate of the input shaft rotation speed follows the target value (or the input shaft rotation speed) in the inertia phase. The shift shock in the inertia phase is reduced by performing the inertia phase control for feedback control of the hydraulic pressure (so that the speed follows the target input shaft rotation speed).

  The conventional inertia phase start point determination method is described in Patent Document 1 (Japanese Patent Laid-Open No. 11-118032), in order to take into account the acceleration of the vehicle, the input shaft rotation speed of the transmission gear mechanism. The shift progress degree evaluation value F is calculated by the following equation (1) using Nt, the output shaft rotational speed No, and the gear ratio gr before the shift, and when F ≧ 0, it is determined that the inertia phase starts. I have to.

No × gr−Nt = F (1)
Actually, in order to consider the fluctuation of the rotation sensor signal for detecting the input shaft rotational speed Nt and the output shaft rotational speed No and the influence of noise, F ≧ Δn (Δn is a determination threshold greater than 0). In this case, that is, when the following equation (2) is satisfied, it is determined that the inertia phase starts.
No.gr-Nt ≧ Δn (2)
However, the equation (2) may be satisfied even before the inertia phase starts. This is because a phenomenon occurs in which the input shaft rotational speed Nt decreases.

  This phenomenon is caused by shifting from a shift stage having a one-way clutch, shifting the accelerator that was stepped on and shifting past the shift line (especially power-off upshift), or manual up operation with the accelerator fully closed. To do. At this time, the input shaft rotation speed Nt decreases due to the engine braking effect.

  When the starting point of the inertia phase is determined by the above equation (2) under the condition that the input shaft rotational speed Nt is reduced in this way, the inertia phase starts even before the filling phase ends. This results in erroneous determination. Due to the erroneous determination of the starting point of the inertia phase, the inertia phase control (feedback control) will start even though the state of the shift clutch is still in the filling phase, and the hydraulic pressure is insufficient and the input shaft The movement of the rotational speed Nt cannot be adjusted appropriately, the shift is delayed, or the hydraulic pressure command value at the moment when the frictional engagement element generates the engagement force becomes high and the actual hydraulic pressure overshoot occurs, Problems such as shift shocks may occur.

  As a countermeasure, it can be considered that the determination threshold value Δn of the equation (2) for detecting the start point of the inertia phase is set to a sufficiently large value. However, in this method, the detection of the start of the inertia phase is delayed. Therefore, there is a problem that the shift shock cannot be sufficiently reduced.

In order to solve this problem, in the technique of Patent Document 1, when the start of the inertia phase is first detected, the inertia phase control is started immediately, and after a predetermined time has elapsed from the start of the inertia phase control, It is determined whether or not the inertia phase is progressing, and if the inertia phase is not progressing, the inertia phase control is stopped.
Japanese Patent Laid-Open No. 11-118032

  However, in the technique of Patent Document 1, since the inertia phase control is started immediately after the start of the inertia phase is detected for the first time, the inertia phase control is erroneously performed during the torque phase due to the phenomenon of a decrease in the input shaft rotational speed Nt. It may start. As described above, in the torque phase hydraulic control (sweep control), control is performed to increase the hydraulic pressure in a feed-forward manner, and therefore inertia phase control (feedback control) is erroneously started during this torque phase. Inertia phase control (feedback control) is started before the required hydraulic pressure is increased, and the hydraulic pressure is insufficient, so that the movement of the input shaft rotational speed Nt cannot be adjusted properly, and a problem such as a delay in shifting occurs. .

  As a countermeasure against this, the present inventor is researching a technique for preventing erroneous determination of inertia phase start (see the specification of Japanese Patent Application No. 2006-038103). According to the research result of the present inventor, an erroneous determination of the inertia phase due to the phenomenon of a decrease in the input shaft rotation speed Nt is likely to occur during a power-off upshift (during an upshift when the engine is not driven). At the time of upshifting, the inertia phase is determined when the engine rotational speed is equal to or lower than the engine rotational speed for determining the engine driving state set by the map according to the input torque of the transmission gear mechanism.

  However, creating a map that accurately sets the engine rotation speed for determining the engine driving state requires a lot of labor and time for the calibration work, which not only increases costs but also increases the accuracy of the map. It is difficult to prevent misjudgment of inertia phase start.

  The present invention has been made in view of such circumstances. Therefore, the object of the present invention is to perform hydraulic control of the filling phase even under conditions where a reduction in the input shaft rotational speed of the transmission gear mechanism occurs during the shift control. It is an object of the present invention to provide a control device for an automatic transmission capable of starting inertia phase control in a state where a sufficient engagement force is generated by a friction engagement element.

  In order to achieve the above object, an invention according to claim 1 is directed to a control device for an automatic transmission in which a driving force of an engine is shifted by a transmission gear mechanism and transmitted to a wheel side. Inertia phase determining means for determining an inertia phase in which the input shaft rotation speed of the transmission gear mechanism changes in accordance with the engaging operation, and the friction engagement element in the inertia phase based on a determination result of the inertia phase determining means Inertia phase control means for performing inertia phase control for feedback control of hydraulic pressure applied to the engine, engine drive state determination means for determining the drive state / non-drive state of the engine, and the engine not driven by the engine drive state determination means When the state is determined, the inertia phase determination by the inertia phase determination means is prohibited until a predetermined determination prohibition period elapses. It is obtained by a structure in which an erroneous determination prevention means.

  In short, an erroneous determination of the inertia phase due to a decrease in the input shaft rotation speed is likely to occur during a power-off upshift (when the engine is in an undriven state), so in the present invention, the engine is in a non-driven state. The determination of the inertia phase is prohibited until a predetermined determination prohibition period elapses. By setting this determination prohibition period to a time required for the friction engagement element to generate a sufficient engagement force, erroneous determination of the inertia phase can be prevented in advance, and the transmission gear mechanism can be used during the shift control. The inertia phase control can be started in a state in which the frictional engagement element generates a sufficient engagement force by the hydraulic control of the filling phase even under the condition that the input shaft rotation speed decreases.

  In this case, as in claim 2, there is provided driving force information detecting means for detecting driving force of the engine or information correlated therewith (hereinafter collectively referred to as “driving force information”). The detected driving force information may be compared with a determination threshold value to determine the engine driving state / non-driving state. If this determination threshold value is set to an engine driving force that ensures that the engine driving state is in the non-driving state, erroneous determination of the non-driving state can be prevented.

  Further, as in claim 3, the determination prohibition period may be variably set according to the engine speed. Since the time required for the frictional engagement element to generate a sufficient engagement force varies depending on the engine rotation speed, if the determination prohibition period is variably set according to the engine rotation speed, the determination prohibition period is set to a predetermined constant value. The determination prohibition period can be set shorter depending on the engine speed than when the time is set, so that the inertia phase determination can be started earlier.

  According to a fourth aspect of the present invention, the determination prohibition period is the elapsed time from the end of the rapid filling phase control in which the frictional engagement element on the engagement side is rapidly filled with hydraulic oil after the start of the shift control or the rapid filling phase control. The time may be set based on the elapsed time from the end of the filling phase control for maintaining the hydraulic pressure that has increased. In this way, the determination prohibition period can be set without being affected by the rapid filling time. Further, if the filling phase is executed for a set time, it is considered that the friction engagement element is generating an engagement force. Therefore, if a predetermined time (may be 0 seconds) is set as the determination prohibition period from that point, the friction is caused. It is possible to reliably prevent the engagement element from erroneously shifting to the inertia phase before generating a sufficient engagement force.

  Further, as in claim 5, the determination threshold value used for determining whether the engine is driven or not may be variably set according to the engine rotational speed or the input shaft rotational speed of the transmission gear mechanism. Even if the engine driving force is the same, whether or not the reduction in the input shaft rotational speed occurs depends on the engine rotational speed and the like. Therefore, if the determination threshold is variably set according to the engine rotational speed, The accuracy of determination of the non-driving state can be increased. The same effect can be obtained by using the input shaft rotational speed (or output shaft rotational speed × gear ratio) of the transmission gear mechanism instead of the engine rotational speed.

  Further, even if the engine driving force is the same, whether the reduction of the input shaft rotation speed of the transmission gear mechanism occurs depends on the output shaft rotation speed of the transmission gear mechanism, the gear stage before the shift, and the shift type. As in item 6, the determination threshold is variably set according to the output shaft rotational speed of the transmission gear mechanism and the gear stage before the shift, or as in claim 7, the determination threshold is set to the transmission gear. You may make it variably set according to the output-shaft rotational speed of a mechanism, and the speed change type. In either case, the accuracy of determination of the engine driving state / non-driving state can be further increased.

  Further, as in claim 8, the throttle opening or the accelerator opening may be detected as the driving force information. Thereby, even when there is no engine driving force signal, the inertia phase determination can be performed without error.

  Hereinafter, seven examples 1 to 7 embodying the best mode for carrying out the present invention will be described.

A first embodiment of the present invention will be described with reference to FIGS.
First, a schematic configuration of the automatic transmission 11 will be described with reference to FIGS. 1 and 2.
As shown in FIG. 2, an input shaft 13 of the torque converter 12 is connected to an output shaft of an engine (not shown), and a hydraulically driven transmission gear mechanism 15 is connected to the output shaft 14 of the torque converter 12. Has been. Inside the torque converter 12, a pump impeller 31 and a turbine runner 32 constituting a fluid coupling are provided to face each other, and a stator 33 for rectifying the flow of oil is provided between the pump impeller 31 and the turbine runner 32. It has been. The pump impeller 31 is connected to the input shaft 13 of the torque converter 12, and the turbine runner 32 is connected to the output shaft 14 of the torque converter 12.

  The torque converter 12 is provided with a lock-up clutch 16 for engaging or disengaging between the input shaft 13 side and the output shaft 14 side. The output torque of the engine is transmitted to the transmission gear mechanism 15 via the torque converter 12, is shifted by a plurality of gears (such as planetary gears) of the transmission gear mechanism 15, and is transmitted to the drive wheels (front wheels or rear wheels) of the vehicle. Is done.

  The transmission gear mechanism 15 is provided with a plurality of clutches C0, C1, C2 and brakes B0, B1, which are friction engagement elements for switching a plurality of shift stages. As shown in FIG. The gear ratio is switched by switching engagement / release of C1 and C2 and the brakes B0 and B1 with hydraulic pressure and switching a combination of gears for transmitting power.

  FIG. 3 shows a combination of engagement of the clutches C0, C1, C2 and the brakes B0, B1 of the four-speed automatic transmission. The circles are held in the engaged state (torque transmission state) at that gear stage. The clutch and brake are shown, and the unmarked state shows the released state. For example, when downshifting from the 3rd speed to the 2nd speed, one of the two clutches C0 and C2 held in the engaged state at the 3rd speed is released, and the brake B1 is engaged instead. By combining, downshift to 2nd speed. In addition, when upshifting from the 3rd speed to the 4th speed, one of the two clutches C0 and C2 held in the engaged state at the 3rd speed is released, and the brake B1 is engaged instead. By combining, upshift to 4th gear.

  As shown in FIG. 1, the transmission gear mechanism 15 is provided with a hydraulic pump 18 driven by engine power, and a hydraulic control circuit 17 is provided in an oil pan (not shown) for storing hydraulic oil (oil). Is provided. The hydraulic control circuit 17 includes a line pressure control circuit 19, an automatic transmission control circuit 20, a lock-up control circuit 21, a manual switching valve 26, and the like. The hydraulic oil pumped up from the oil pan by the hydraulic pump 18 is line pressure controlled. This is supplied to the automatic transmission control circuit 20 and the lockup control circuit 21 via the circuit 19. The line pressure control circuit 19 is provided with a hydraulic pressure control valve (not shown) for controlling the hydraulic pressure from the hydraulic pump 18 to a predetermined line pressure. The automatic transmission control circuit 20 has a transmission gear mechanism. A plurality of shift hydraulic control valves (not shown) for controlling the hydraulic pressure supplied to the 15 clutches C0, C1, C2 and the brakes B0, B1 are provided. The lockup control circuit 21 is provided with a lockup control hydraulic control valve (not shown) for controlling the hydraulic pressure supplied to the lockup clutch 16.

  A manual switching valve 26 that is switched in conjunction with the operation of the shift lever 25 is provided between the line pressure control circuit 19 and the automatic transmission control circuit 20. When the shift lever 25 is operated to the neutral range (N range) or the parking range (P range), even if the energization to the hydraulic control valve of the automatic transmission control circuit 20 is stopped (OFF), The hydraulic pressure supplied to the transmission gear mechanism 15 by the manual switching valve 26 is switched so that the transmission gear mechanism 15 is in a neutral state.

  On the other hand, the engine is provided with an engine rotation speed sensor 27 for detecting the engine rotation speed, and the transmission gear mechanism 15 detects the input shaft rotation speed Nt of the transmission gear mechanism 15 (the output shaft rotation speed of the torque converter 12). An input shaft rotational speed sensor 28 for detecting the output shaft rotational speed No. of the transmission gear mechanism 15 is provided.

  Output signals of these various sensors are input to an automatic transmission electronic control circuit (hereinafter referred to as “AT-ECU”) 30. The AT-ECU 30 is mainly composed of a microcomputer, and executes each shift control routine stored in a built-in ROM (storage medium), whereby the shift gear mechanism 15 shifts according to a preset shift pattern. To each hydraulic control valve of the automatic transmission control circuit 20 in response to a shift request (shift stage switching request) generated according to the operating position of the shift lever 25 and the operating conditions (throttle opening, vehicle speed, etc.). As shown in FIG. 3, the clutches C0, C1, C2 and the brakes B0, B1 are controlled by controlling the energization of the clutches C0, C1, C2 and the brakes B0, B1, respectively. The gear ratio of the transmission gear mechanism 15 is switched by switching the engagement / release of each brake B0, B1 and switching the combination of gears that transmit power. Obtain. In the following description, the clutches C0, C1, C2 and the brakes B0, B1 are collectively referred to as “friction engagement elements”.

  The AT-ECU 30 performs a filling control for filling the friction engagement element that switches from the released state to the engaged state in the shift control for switching the gear position of the transmission gear mechanism 15, and the friction that switches from the engaged state to the released state. Discharge control for discharging hydraulic oil from the engagement element is performed.

  In this shift control, as shown in FIG. 4, hydraulic fluid is rapidly applied to the engagement-side friction engagement element until the engagement-side friction engagement element is in a state immediately before the engagement force is generated at the initial stage of the shift control. After controlling the rapid filling phase for charging the filling phase, the filling phase is controlled to maintain the hydraulic pressure (standby hydraulic pressure) increased by the rapid filling phase control, and then the torque sharing of each friction engagement element changes. After passing through the torque phase which is a stage, the phase shifts to the inertia phase where the ratio of the rotational speed between the input and output shafts of the transmission gear mechanism 15 (that is, the gear ratio) changes. At this time, in the torque phase control, a sweep control for increasing the hydraulic pressure in a feed-forward manner is executed, and in the subsequent inertia phase control, the hydraulic pressure is feedback-controlled based on the input shaft rotational speed Nt of the transmission gear mechanism 15.

  In this inertia phase, torque (inertia torque) is generated due to a change in the inertial force of the rotating system in the transmission gear mechanism 15, and a change shock may occur due to a change in the output shaft torque of the transmission gear mechanism 15 due to this inertia torque. . Since it is known that the shift shock generated in the inertia phase depends on the change rate of the input shaft rotation speed Nt, the change rate of the input shaft rotation speed Nt follows the target value (or input) in the inertia phase. The shift shock in the inertia phase is reduced by performing the inertia phase control for feedback control of the hydraulic pressure so that the shaft rotation speed Nt follows the target input shaft rotation speed. The function of the AT-ECU 30 performing inertia phase control corresponds to inertia phase control means in the claims.

  As described above, when the start point of the inertia phase is determined under the condition that the input shaft rotation speed Nt decreases during the shift control, the start of the inertia phase is started even before the actual start of the inertia phase. May be misjudged. Due to the erroneous determination of the starting point of the inertia phase, the inertia phase control (feedback control) will start even though the state of the shift clutch is still in the filling phase, and the hydraulic pressure is insufficient and the input shaft The movement of the rotational speed Nt cannot be adjusted appropriately, the shift is delayed, or the hydraulic pressure command value at the moment when the frictional engagement element generates the engagement force becomes high and the actual hydraulic pressure overshoot occurs, Problems such as shift shocks may occur.

  As a countermeasure against this, the AT-ECU 30 determines a driving state (power on) / non-driving state (power off) of the engine during the shift control by executing a shift control routine of FIG. Is determined until the predetermined time (determination prohibition period) elapses from the start of the shift control. In short, an erroneous determination of the inertia phase due to a decrease in the input shaft rotation speed Nt is likely to occur during a power-off upshift (when the engine is in an undriven state), so in the first embodiment, the engine is in an undriven state. In this case, inertia phase determination is prohibited until a predetermined determination prohibition period (predetermined time) elapses. By setting the determination prohibition period to a time necessary for the friction engagement element to generate a sufficient engagement force, erroneous determination of the inertia phase can be prevented in advance.

  Hereinafter, the processing content of each routine of FIG.5 and FIG.6 which AT-ECU30 performs is demonstrated. The shift control routine of FIG. 5 is executed at a predetermined cycle during engine operation. When this routine is started, first, at step 101, it is determined whether or not the shift control is being performed (a period from when the requested shift stage is switched until the shift is completed). This routine is terminated without performing the above process.

  On the other hand, if it is determined in step 101 that the shift control is being performed, the process proceeds to step 102, where it is determined whether or not it is the first calculation cycle (at the start of this routine) after the shift control is started. If it is the first calculation cycle after the start, the process proceeds to step 103 and the timer is reset to 0. If it is not the first calculation cycle after the shift control is started, the process proceeds to step 104 and the timer is counted up. Thereby, the elapsed time after the start of the shift control is counted by the timer.

  Thereafter, the process proceeds to step 105, and it is determined whether or not the engine is in a non-driving state based on an engine control parameter related to the engine driving force. Here, the “non-driving state” means a state in which the engine generates negative torque (a deceleration state in which the engine brake is working). The process of step 105 serves as engine drive state determination means in the claims. If it is determined in step 105 that the engine is not in the non-driving state, the process proceeds to step 107, where the inertia phase determination permission flag is set to ON to permit inertia phase determination.

  On the other hand, if it is determined in step 105 that the engine is in a non-driving state, the process proceeds to step 106, and whether or not the count value of the timer (elapsed time after the start of the shift control) is equal to or longer than a predetermined time. If the count value of the timer is less than the predetermined time, the routine proceeds to step 108, where the inertia phase determination permission flag is set to OFF and the inertia phase determination is prohibited. Thus, inertia phase determination is prohibited until a predetermined time (determination prohibition period) elapses from the start of the shift control. The processing in these steps 106 and 108 serves as an erroneous determination prevention means in the claims.

  In this case, the predetermined time (determination prohibition period) may be set to a predetermined time, but the predetermined time (determination prohibition period) may be variably set according to the operating conditions. FIG. 7 shows an example in which the predetermined time (determination prohibition period) is variably set according to the engine speed. In the example of FIG. 7, the predetermined time (determination prohibition period) is set shorter as the engine speed increases. Since the time required for the frictional engagement element to generate a sufficient engagement force varies depending on the engine speed, if the predetermined time (determination prohibited period) is variably set according to the engine rotational speed, the predetermined time (determination prohibited) The predetermined period (determination prohibition period) can be set shorter depending on the engine speed than when the predetermined period is set to a predetermined period, and the inertia phase determination can be started earlier. .

  When it is determined in step 106 that the count value of the timer (elapsed time after the start of the shift control) has reached a predetermined time, the routine proceeds to step 107, where the inertia phase determination permission flag is set to ON to determine the inertia phase. Allow.

  Thereafter, the routine proceeds to step 109, where the inertia phase determination routine of FIG. 6 is executed. The inertia phase determination routine of FIG. 6 serves as inertia phase determination means in the claims. When this routine is started, first, in step 201, it is determined whether the inertia phase determination permission flag is ON (permitted). If the inertia phase determination permission flag is OFF (prohibited), the subsequent processing is performed. This routine is terminated without performing it.

  On the other hand, if it is determined in step 201 that the inertia phase determination permission flag is ON (permitted), the process proceeds to step 202 where the current input shaft rotational speed Nt (or gear ratio) is read and the next step 203 is performed. It is determined whether or not the current input shaft rotation speed Nt (or gear ratio) is lower than the inertia phase determination threshold, and the current input shaft rotation speed Nt (or gear ratio) gear ratio is determined as the inertia phase. If it is greater than or equal to the threshold value, it is determined that the inertia phase has not yet started (torque phase or filling phase), and this routine is immediately terminated.

  On the other hand, if it is determined in step 203 that the current input shaft rotation speed Nt (or gear ratio) is lower than the inertia phase determination threshold value, the process proceeds to step 204 to determine the inertia phase.

  FIG. 8 shows an example of the shift control according to the first embodiment. In the example of FIG. 8, at the time t1 when the required shift speed is switched from the first speed to the second speed and the shift control is started, a timer counting operation is started and the elapsed time after the start of the shift control is counted. During this shift control, at the time t2 when the determination of the engine driving state is switched to the non-driving state, the inertia phase determination permission flag is set to OFF and the inertia phase determination is prohibited.

  Thereafter, at a time t3 when the count value of the timer (elapsed time after the start of the shift control) exceeds a predetermined time (determination prohibition period), the inertia phase determination permission flag is set to ON and the inertia phase determination is permitted. Thereafter, whether or not the phase is the inertia phase is determined based on whether or not the input shaft rotation speed Nt (or the gear ratio) is lower than the inertia phase determination threshold value. In this example, the input shaft rotational speed Nt (or gear ratio) is already lower than the inertia phase determination threshold at the time t3 when the count value of the timer (elapsed time after the start of the shift control) reaches a predetermined time. Therefore, the inertia phase is immediately determined (the inertia phase flag is set to ON).

  According to the first embodiment described above, in consideration of the fact that erroneous determination of the inertia phase is likely to occur during a power-off upshift (when the engine is not driven), the engine is controlled during the shift control. It is determined whether or not the engine is in the non-driving state, and in the non-driving state, the inertia phase determination is prohibited until a predetermined time (determination prohibition period) has elapsed since the start of the shift control. The determination can be prevented in advance, and the friction engagement element can provide sufficient engagement force by the hydraulic control of the filling phase even under the condition that the decrease of the input shaft rotational speed Nt of the transmission gear mechanism 15 occurs during the shift control. Inertia phase control can be started in the generated state, and shift shocks and shift delays can be prevented.

  Next, Embodiment 2 of the present invention will be described with reference to FIGS. In the second embodiment, the engine torque, which is the driving force of the engine, is compared with a predetermined determination threshold value to determine the engine driving state / non-driving state.

  The speed change control routine of FIG. 9 executed in the second embodiment is simply the processing of step 105 in the speed change control routine of FIG. 5 described in the first embodiment is changed to the process of step 105a. The process is the same.

  In the shift control routine of FIG. 9, the elapsed time after the start of shift control is counted by a timer in the processing of steps 101 to 104, and then the routine proceeds to step 105a, where is the current engine torque less than or equal to a predetermined determination threshold value? If not, it is determined whether or not the engine is in a non-driven state. At this time, the engine torque may be calculated based on the current engine operating conditions (engine rotational speed, load factor, etc.). Alternatively, the required engine torque used for engine torque control may be used.

  Further, the determination threshold value is 0 or a little larger than it, and may be a predetermined threshold value. However, even if the engine torque is the same, the input shaft rotation of the transmission gear mechanism 15 Whether or not the decrease in the speed Nt occurs depends on the engine speed or the like. For example, the determination threshold value of the engine torque may be variably set according to the engine speed using the map of FIG. Thereby, the accuracy of determination of the driving state / non-driving state of the engine can be improved. The characteristics of the map of FIG. 10 are set so that the engine torque determination threshold value increases as the engine speed increases.

  Further, instead of the engine rotation speed, the engine torque determination threshold value is variably set according to the input shaft rotation speed Nt (or output shaft rotation speed No × gear ratio) of the transmission gear mechanism 15 using the map of FIG. You may make it do. The characteristics of the map of FIG. 11 are set such that the engine torque determination threshold value increases as the input shaft rotational speed Nt of the transmission gear mechanism 15 increases.

  Further, whether or not the input shaft rotational speed Nt of the transmission gear mechanism 15 decreases even when the engine torque is the same depends on the output shaft rotational speed No of the transmission gear mechanism 15, the gear stage before the shift, and the shift type. Therefore, the determination threshold value of the engine torque may be variably set according to the output shaft rotational speed No of the transmission gear mechanism 15 and the gear stage before the shift using the map of FIG. 12, or the map of FIG. May be used to variably set the engine torque determination threshold according to the output shaft rotational speed and speed change type of the transmission gear mechanism 15, and in any case, determination of the engine drive state / non-drive state Accuracy can be further increased.

  The characteristics of the map of FIG. 12 indicate that the engine torque determination threshold increases stepwise as the output shaft rotational speed of the transmission gear mechanism 15 increases and the engine torque increases as the shift speed before the shift increases. The determination threshold is set to be small.

  The characteristics of the map of FIG. 13 are gear shifts to the stage side where the determination threshold value of the engine torque increases stepwise and the shift type is higher as the output shaft rotational speed of the transmission gear mechanism 15 increases. The engine torque determination threshold is set to be smaller.

  If it is determined in step 105a that the current engine torque is greater than the determination threshold value, it is determined that the engine is in a driving state, and the process proceeds to step 107, where the inertia phase determination permission flag is set to ON. Allow inertia phase judgment.

  On the other hand, if it is determined in step 105a that the current engine torque is equal to or less than the determination threshold value, it is determined that the engine is in a non-driving state, the process proceeds to step 106, and the timer count value ( If the timer count value is less than the predetermined time, the process proceeds to step 108, the inertia phase determination permission flag is set to OFF, and the inertia is determined. Prohibit phase judgment.

  Thereafter, when it is determined that the count value of the timer (elapsed time after the start of the shift control) has reached a predetermined time, the routine proceeds to step 107, where the inertia phase determination permission flag is set to ON and the inertia phase determination is permitted. . Other processes are the same as those in the shift control routine of FIG. 5 described in the first embodiment.

  FIG. 14 shows an example of shift control according to the second embodiment. In the example of FIG. 14, at the time t1 when the required shift speed is switched from the first speed to the second speed and the shift control is started, the timer starts counting, and the elapsed time after the start of the shift control is counted. In this example, since the engine torque is already equal to or less than the determination threshold value at the time t1 when the shift starts, it is determined that the engine is in a non-driving state, the inertia phase determination permission flag is set to OFF, and the inertia phase Judgment is prohibited.

  Thereafter, at a time t2 when the count value of the timer (elapsed time after the start of the shift control) exceeds a predetermined time (determination prohibition period), the inertia phase determination permission flag is set to ON and the inertia phase determination is permitted. Thereafter, whether or not the phase is the inertia phase is determined based on whether or not the input shaft rotation speed Nt (or the gear ratio) is lower than the inertia phase determination threshold value. In this example, the input shaft rotational speed Nt (or gear ratio) has already become lower than the inertia phase determination threshold at the time t2 when the count value of the timer (elapsed time after the start of the shift control) reaches a predetermined time. Therefore, it is immediately determined as an inertia phase.

  In the second embodiment described above, the same effect as that of the first embodiment can be obtained.

  In the third embodiment of the present invention, the shift control routine of FIG. 15 is executed. The shift control routine of FIG. 15 is the same as the process of step 102a except that the process of step 102 of the shift control routine of FIG. 9 described in the second embodiment is changed to the process of step 102a. .

  In the shift control routine of FIG. 15, if it is determined in step 101 that the shift control is being performed, the process proceeds to step 102a to determine whether it is before the end of the rapid filling phase. The process proceeds to step 103, the timer is reset to 0, and if it is not before the rapid filling phase, the process proceeds to step 104 and the timer is counted up. Thereby, the elapsed time after the end of the rapid filling phase is counted by the timer.

  Thereafter, the process proceeds to step 105a, where it is determined whether or not the engine is in a non-driven state based on whether or not the current engine torque is equal to or less than a predetermined determination threshold value. In Step 106, it is determined whether the timer count value (elapsed time after the end of the rapid filling phase) is equal to or greater than a predetermined time. If the timer count value is less than the predetermined time, the process proceeds to Step 108. The inertia phase determination permission flag is set to OFF to prohibit inertia phase determination.

  Thereafter, when it is determined that the count value of the timer (elapsed time after the end of the rapid filling phase) has reached a predetermined time, the routine proceeds to step 107, where the inertia phase determination permission flag is set to ON and the inertia phase determination is permitted. To do.

  FIG. 16 shows an example of shift control according to the third embodiment. In the example of FIG. 16, the control of the rapid filling phase is started at the time t1 when the required shift speed is switched from the first speed to the second speed and the shift control is started, and the time t2 when the control of the rapid filling phase is finished. Thus, the timer count operation is started and the elapsed time after the end of the rapid filling phase is counted. In this example, since the engine torque is already equal to or less than the determination threshold value at the time t1 when the shift starts, it is determined that the engine is in a non-driving state, the inertia phase determination permission flag is set to OFF, and the inertia phase Judgment is prohibited.

  Thereafter, at time t3 when the count value of the timer (elapsed time after the end of the rapid filling phase) exceeds a predetermined time (determination prohibition period), the inertia phase determination permission flag is set to ON and the inertia phase determination is permitted. Thereafter, whether or not the phase is the inertia phase is determined based on whether or not the input shaft rotation speed Nt (or the gear ratio) is lower than the inertia phase determination threshold value. In this example, the input shaft rotational speed Nt (or gear ratio) is already lower than the inertia phase determination threshold at time t3 when the count value of the timer (elapsed time after the end of the rapid filling phase) reaches a predetermined time. Therefore, it is immediately determined as an inertia phase.

  In the third embodiment described above, the same effect as in the first embodiment can be obtained, and the inertia phase determination prohibition period (predetermined time) is set as the elapsed time after the end of the rapid filling phase. Therefore, the determination prohibition period can be set without being affected by the time of the rapid filling phase.

  In the fourth embodiment of the present invention, the shift control routine of FIG. 17 is executed. In the shift control routine of FIG. 17, only the process of step 102a of the shift control routine of FIG. 15 described in the third embodiment is changed to the process of step 102b, and the processes of the other steps are the same. .

  In the shift control routine of FIG. 17, if it is determined in step 101 that the shift control is being performed, the process proceeds to step 102b, and is it before the end of the filling phase for maintaining the hydraulic pressure (standby hydraulic pressure) increased in the rapid filling phase? If not, the process proceeds to step 103, where the timer is reset to 0. If not, the process proceeds to step 104, where the timer is counted up. Thereby, the elapsed time after the completion of the filling phase is counted by the timer.

  Thereafter, the process proceeds to step 105a, where it is determined whether or not the engine is in a non-driven state based on whether or not the current engine torque is equal to or less than a predetermined determination threshold value. In Step 106, it is determined whether the count value of the timer (elapsed time after the end of the filling phase) is equal to or greater than a predetermined time (may be 0 seconds), and if the count value of the timer is less than the predetermined time, Proceeding to step 108, the inertia phase determination permission flag is set to OFF and the inertia phase determination is prohibited.

  Thereafter, when it is determined that the count value of the timer (elapsed time after completion of the filling phase) has reached a predetermined time, the routine proceeds to step 107, where the inertia phase determination permission flag is set to ON and the inertia phase determination is permitted. .

  FIG. 18 shows an example of shift control according to the fourth embodiment. In the example of FIG. 18, the control of the rapid filling phase is started at the time t1 when the required shift speed is switched from the first speed to the second speed and the shift control is started, and the time t2 when the control of the rapid filling phase is finished. Then, the control shifts to the control of the filling phase. Thereafter, at the time point t3 when the control of the filling phase is completed, the timer starts counting, and the elapsed time after the completion of the filling phase is counted. In this example, since the engine torque is already equal to or less than the determination threshold value at the time t1 when the shift starts, it is determined that the engine is in a non-driving state, the inertia phase determination permission flag is set to OFF, and the inertia phase Judgment is prohibited.

  Thereafter, at time t4 when the count value of the timer (elapsed time after the end of the filling phase) exceeds a predetermined time (determination prohibition period), the inertia phase determination permission flag is set to ON and the inertia phase determination is permitted. Thereafter, whether or not the phase is the inertia phase is determined based on whether or not the input shaft rotation speed Nt (or the gear ratio) is lower than the inertia phase determination threshold value. In this example, the input shaft rotational speed Nt (or gear ratio) is already lower than the inertia phase determination threshold at the time t4 when the count value of the timer (elapsed time after the end of the filling phase) reaches a predetermined time. Therefore, it is immediately determined as an inertia phase.

  In this case, if the filling phase is executed for a set time, it is considered that the friction engagement element generates an engagement force. Therefore, as in the fourth embodiment, a predetermined time (may be 0 second) from the end of the filling phase. Is set as the determination prohibition period, it is possible to reliably prevent the friction engagement element from erroneously shifting to the inertia phase before generating a sufficient engagement force.

  Next, Embodiment 5 of the present invention will be described with reference to FIGS. In the fifth embodiment, the throttle opening, which is information correlated with the driving force of the engine, is compared with a predetermined determination threshold value to determine the driving state / non-driving state of the engine.

  The shift control routine of FIG. 19 executed in the fifth embodiment is merely the processing of step 105a of the shift control routine of FIG. 9 described in the second embodiment changed to the process of step 105b. The process is the same.

  In the shift control routine of FIG. 19, the elapsed time after the start of the shift control is counted by a timer by the processing of steps 101 to 104, and then the routine proceeds to step 105b, where the current throttle opening is equal to or less than a predetermined determination threshold value. Whether or not the engine is in a non-driven state. At this time, the throttle opening may be a value detected by a throttle opening sensor. Alternatively, a required throttle opening (target throttle opening) used for electronic throttle control may be used.

  Further, the determination threshold value is 0 (throttle fully closed) or a value slightly larger than that, and may be a predetermined determination threshold value. Since whether or not the input shaft rotational speed Nt of the mechanism 15 is reduced depends on the engine rotational speed and the like, for example, the determination threshold value of the throttle opening is variably set according to the engine rotational speed using the map of FIG. This may improve the accuracy of determination of the engine driving state / non-driving state. The characteristics of the map of FIG. 20 are set such that the determination threshold value of the throttle opening increases as the engine speed increases.

  In addition, the threshold value for determining the throttle opening is set as the input shaft rotational speed Nt (or output shaft rotational speed No.times.gear ratio) of the transmission gear mechanism 15 increases using the map of FIG. 21 instead of the engine rotational speed. You may make it enlarge. Alternatively, the determination threshold value of the throttle opening may be increased as the output shaft rotational speed No of the transmission gear mechanism 15 increases using the map of FIG.

  Further, even if the engine torque is the same, whether or not the input shaft rotation speed Nt of the transmission gear mechanism 15 is reduced depends on the gear stage before the gear shift and the gear type. The determination threshold value of the throttle opening is variably set according to the output shaft rotational speed No of the mechanism 15 and the gear position before the shift, or the output shaft of the transmission gear mechanism 15 is used using the map of FIG. The determination threshold value of the throttle opening may be variably set according to the rotational speed No and the shift type, and in either case, the accuracy of determination of the driving state / non-driving state of the engine can be further increased. .

  The map characteristics of FIG. 23 show that the throttle opening determination threshold increases stepwise as the output shaft rotational speed No of the transmission gear mechanism 15 increases, and the throttle opening increases as the gear stage before the shift increases. Is set so that the determination threshold of the degree becomes small.

  The characteristics of the map of FIG. 24 are that the determination threshold value of the throttle opening increases stepwise as the output shaft rotational speed No of the transmission gear mechanism 15 increases, and the gear shift toward the higher gear is performed. The threshold value is set so that the threshold value for determining the throttle opening becomes smaller.

  If it is determined in step 105b that the current throttle opening is larger than the determination threshold value, it is determined that the engine is in a driving state, the process proceeds to step 107, and the inertia phase determination permission flag is set to ON. Permit inertia phase judgment.

  On the other hand, if it is determined in step 105b that the current throttle opening is equal to or smaller than the determination threshold value, it is determined that the engine is in a non-driving state, and the process proceeds to step 106, where the count value of the timer is determined. It is determined whether (elapsed time after the start of the shift control) is equal to or longer than a predetermined time. If the count value of the timer is less than the predetermined time, the process proceeds to step 108, and the inertia phase determination permission flag is set to OFF. Inertia phase judgment is prohibited. Other processes are the same as those in the shift control routine of FIG. 9 described in the second embodiment.

  In the fifth embodiment described above, the same effect as that of the second embodiment can be obtained.

  In the sixth embodiment of the present invention, the shift control routine of FIG. 25 is executed. In the shift control routine of FIG. 25, only the processing of step 102 of the shift control routine of FIG. 19 described in the fifth embodiment is changed to the processing of step 102a, and the processing of other steps is the same. .

  In the shift control routine of FIG. 25, if it is determined in step 101 that the shift control is being performed, the process proceeds to step 102a, where it is determined whether or not it is before the end of the rapid filling phase. The process proceeds to step 103, the timer is reset to 0, and if it is not before the rapid filling phase, the process proceeds to step 104 and the timer is counted up. Thereby, the elapsed time after the end of the rapid filling phase is counted by the timer.

  Thereafter, the process proceeds to step 105b, where it is determined whether or not the engine is in a non-driven state based on whether or not the current throttle opening is equal to or smaller than a predetermined determination threshold value (see FIG. 16). If it is determined that there is, the process proceeds to step 106, where it is determined whether or not the timer count value (elapsed time after the end of the rapid filling phase) is equal to or greater than a predetermined time. In step 108, the inertia phase determination permission flag is set to OFF to prohibit the inertia phase determination.

  Thereafter, when it is determined that the count value of the timer (elapsed time after the end of the rapid filling phase) has reached a predetermined time, the routine proceeds to step 107, where the inertia phase determination permission flag is set to ON and the inertia phase determination is permitted. To do.

  Also in the sixth embodiment described above, the same effect as in the third embodiment can be obtained.

  In the seventh embodiment of the present invention, the shift control routine of FIG. 26 is executed. The shift control routine of FIG. 26 is the same as the process of step 102b except that the process of step 102a of the shift control routine of FIG. 26 described in the sixth embodiment is changed to the process of step 102b. .

  In the shift control routine of FIG. 26, if it is determined in step 101 that the shift control is being performed, the process proceeds to step 102b, where it is determined whether or not it is before the end of the filling phase. The process proceeds to 103, the timer is reset to 0, and if it is not before the filling phase, the process proceeds to step 104 and the timer is counted up. Thereby, the elapsed time after the completion of the filling phase is counted by the timer.

  Thereafter, the process proceeds to step 105b, where it is determined whether or not the engine is in a non-driven state based on whether or not the current throttle opening is equal to or less than a predetermined determination threshold value (see FIG. 18). If it is determined that there is, the routine proceeds to step 106, where it is determined whether or not the count value of the timer (elapsed time after completion of the filling phase) is equal to or longer than a predetermined time (may be 0 seconds). If it is less than the time, the routine proceeds to step 108, where the inertia phase determination permission flag is set to OFF and the inertia phase determination is prohibited.

  Thereafter, when it is determined that the count value of the timer (elapsed time after completion of the filling phase) has reached a predetermined time, the routine proceeds to step 107, where the inertia phase determination permission flag is set to ON and the inertia phase determination is permitted. .

Also in the seventh embodiment described above, the same effect as in the fourth embodiment can be obtained.
Needless to say, the present invention is not limited to a four-speed automatic transmission, but can be applied to an automatic transmission having three or less speeds or five or more speeds.

It is a schematic block diagram of the whole automatic transmission in Example 1 of this invention. It is a figure which shows typically the mechanical structure of an automatic transmission. It is a figure which shows the combination of engagement / release of clutch C0-C2 and brake B0, B1 of each gear stage. It is a time chart for demonstrating the phase transition during transmission control. 6 is a flowchart illustrating a process flow of a shift control routine according to the first embodiment. 6 is a flowchart illustrating a flow of processing of an inertia phase determination routine according to the first embodiment. It is a figure which shows an example of the map which variably sets predetermined time according to an engine speed. 3 is a time chart for explaining an example of shift control according to the first embodiment. 6 is a flowchart illustrating a flow of processing of a shift control routine according to a second embodiment. It is a figure which shows the map (example 1) of the determination threshold value of an engine torque. It is a figure which shows the map (example 2) of the determination threshold value of an engine torque. It is a figure which shows the map (example 3) of the determination threshold value of an engine torque. It is a figure which shows the map (example 4) of the determination threshold value of an engine torque. 6 is a time chart for explaining an example of shift control in Examples 2 and 5; 12 is a flowchart illustrating a flow of processing of a shift control routine according to a third embodiment. 6 is a time chart for explaining an example of shift control according to third and sixth embodiments. 10 is a flowchart showing a flow of processing of a shift control routine according to a fourth embodiment. 6 is a time chart for explaining an example of shift control in Examples 4 and 7. FIG. 10 is a flowchart showing a flow of processing of a shift control routine according to a fifth embodiment. It is a figure which shows the map (example 1) of the determination threshold value of throttle opening. It is a figure which shows the map (example 2) of the determination threshold value of throttle opening. It is a figure which shows the map (example 3) of the determination threshold value of throttle opening. It is a figure which shows the map (example 4) of the determination threshold value of throttle opening. It is a figure which shows the map (example 5) of the determination threshold value of throttle opening. FIG. 18 is a flowchart illustrating a process flow of a shift control routine according to a sixth embodiment. FIG. 18 is a flowchart illustrating a process flow of a shift control routine according to a seventh embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Automatic transmission, 12 ... Torque converter, 15 ... Transmission gear mechanism, 17 ... Hydraulic control circuit, 18 ... Hydraulic pump, 19 ... Line pressure control circuit, 20 ... Automatic transmission control circuit, 21 ... Lock-up control circuit, 30 ... AT-ECU (Inertia phase determination means, inertia phase control means, engine drive state determination means, erroneous determination prevention means, drive force information detection means), C0 to C2 ... Clutch (friction engagement element), B0, B1 ... Brake (Friction engagement element)

Claims (8)

In a control device for an automatic transmission that shifts the driving force of an engine with a transmission gear mechanism and transmits it to a wheel side,
Inertia phase determination means for determining an inertia phase in which the input shaft rotation speed of the transmission gear mechanism changes in accordance with the engagement operation of the friction engagement element of the transmission gear mechanism;
An inertia phase control means for performing an inertia phase control for feedback control of a hydraulic pressure applied to the friction engagement element in the inertia phase based on a determination result of the inertia phase determination means;
Engine driving state determination means for determining the driving state / non-driving state of the engine;
Erroneous determination prevention means for prohibiting the inertia phase determination by the inertia phase determination means until a predetermined determination prohibition period elapses when the engine drive state determination means determines that the engine is in a non-drive state. A control device for an automatic transmission. A driving force information detecting means for detecting the driving force of the engine or information related thereto (hereinafter collectively referred to as “driving force information”);
2. The engine driving state determination unit compares the driving force information detected by the driving force information detection unit with a determination threshold value to determine a driving state / non-driving state of the engine. The automatic transmission control device described.   The control apparatus for an automatic transmission according to claim 1 or 2, wherein the erroneous determination preventing means variably sets the determination prohibition period according to an engine speed.   The misjudgment prevention means is configured to determine whether the judgment prohibition period is an elapsed time from the end of the rapid filling phase control in which hydraulic fluid is rapidly filled in the friction engagement element on the engagement side after the start of the shift control or the rapid filling phase control. 4. The control device for an automatic transmission according to claim 1, wherein the automatic transmission control device is set based on an elapsed time from the end of the filling phase control for maintaining the hydraulic pressure increased by.   The engine drive state determination means variably sets the determination threshold value used for determination of the drive state / non-drive state of the engine according to an engine rotation speed or an input shaft rotation speed of the transmission gear mechanism. The control device for an automatic transmission according to any one of claims 1 to 4.   The engine drive state determination means variably sets the determination threshold value used for determination of the drive state / non-drive state of the engine according to the output shaft rotational speed of the transmission gear mechanism and the gear stage before the shift. The control apparatus for an automatic transmission according to any one of claims 1 to 4.   The engine drive state determination means variably sets the determination threshold value used for determination of the drive state / non-drive state of the engine in accordance with an output shaft rotational speed and a shift type of the transmission gear mechanism. The control device for an automatic transmission according to any one of claims 1 to 4.   The control device for an automatic transmission according to claim 2, wherein the driving force information detecting means detects a throttle opening or an accelerator opening as the driving force information.

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