JP7136051B2 - Control device for planetary gear type automatic transmission - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control device for a planetary gear type automatic transmission in which gear shifting is performed, which suppresses the shock caused by rattling caused by clogging of play in the automatic transmission during gear shifting, and lengthens the time required for gear shifting. It relates to a technology for suppressing becoming.

2. Description of the Related Art There is known a control device for a planetary gear type automatic transmission that shifts gears by switching the operating state of a predetermined frictional engagement device out of a plurality of frictional engagement devices. For example, a control device for a planetary gear type automatic transmission described in Patent Document 1 is one of them. In Patent Document 1, when the gear shifting operation is performed by the automatic transmission, the gear shifting operation of the automatic transmission is performed when there is no backlash, that is, play in the mechanical parts constituting the drive system of the vehicle. The engagement pressure of the engagement-side frictional engagement device that is engaged by is lowered for a predetermined time from the start of engagement from the normal time, so that the engagement-side frictional engagement device is gently engaged. It is disclosed that the shock at the time of hitting due to the tightness of the backlash is suppressed. However, if the engagement pressure of the engagement-side frictional engagement device is reduced in order to suppress the shock at the time of rattling as in Patent Document 1, the time required for the gear shift becomes longer, that is, the progress of the gear shift becomes stagnant. there's a possibility that.

JP 2004-347066 A

On the other hand, the engagement pressure of the reaction force friction engagement device connected to a predetermined rotating element responsible for the reaction force associated with the engagement of the engagement side friction engagement device is temporarily changed during the shift transition. By setting the standby pressure to be lower than the engagement pressure of the reaction force friction engagement device before the shift, the reaction force friction engagement device is caused to slip when the backlash is struck, and the shock at the time of the backlash is favorably reduced. It is conceivable to suppress With this method, since it is not necessary to lower the engagement pressure of the engagement-side frictional engagement device from the start of engagement during gear shifting, it is possible to suitably suppress the time required for gear shifting from becoming longer. be able to.

By the way, when the torque capacity of the reaction force friction engagement device changes due to, for example, aging, the reaction force friction engagement device suppresses the shock caused by the backlash and shortens the time required for the gear shift. There is a problem that it becomes impossible to suppress the lengthening. In other words, when the torque capacity of the reaction force friction engagement device is relatively high, the reaction force friction engagement device is less likely to slip when the backlash is struck, and the shock generated when the backlash is struck can be released favorably. When the torque capacity of the reaction force friction engagement device is relatively low, the reaction force friction engagement device becomes close to the released state, and the time required for the shift increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to suppress the shock caused by rattling and to suppress the length of time required for gear shifting. An object of the present invention is to provide a control device for a transmission.

As a result of various investigations, the inventor has arrived at the following fact. That is, when the engagement pressure of the reaction force friction engagement device is temporarily reduced to the standby pressure, the rotational speed of the input shaft of the automatic transmission is reduced from the rotational speed of the input shaft at the start of shifting to the above-mentioned It changes until the backlash inside the automatic transmission is eliminated, but after the backlash inside the automatic transmission is eliminated, the rotation speed of the input shaft temporarily stops changing, and the automatic transmission at the start of the shift. When the torque capacity of the frictional engagement device for reaction force is relatively low However, it was found that the torque capacity of the reaction force friction engagement device is relatively high. When the standby pressure of the reaction force friction engagement device is changed according to the rotation speed change amount, that is, when the rotation speed change amount is relatively large, the reaction force friction engagement device By reducing the standby pressure and increasing the standby pressure of the reaction force friction engagement device when the rotation speed change amount is relatively small, the shock at the time of rattling can be suppressed and the time required for shifting can be reduced. I discovered that I could suppress the lengthening. The present invention has been made based on such findings.

The gist of the first invention is that (a) the engaged state of the reaction force frictional engagement device connected to a predetermined rotating element that bears the reaction force associated with gear shifting is different from the predetermined rotating element. (b) the frictional engagement device for reaction force is set to a standby pressure temporarily lower than the engagement pressure before the gear shift during the transition of the gear shift; Learning is performed according to the amount of change in rotational speed from the rotational speed of the input shaft when the internal play of the automatic transmission is reduced.

According to the first aspect of the invention, (b) the reaction force friction engagement device is set to a standby pressure temporarily lower than the engagement pressure before the gear shift during the transition of the gear shift, and (c) the standby pressure is Learning is performed according to the rotation speed change amount between the rotation speed of the input shaft of the automatic transmission at the start of the shift and the rotation speed of the input shaft when the backlash inside the automatic transmission is eliminated. For this reason, the standby pressure is learned in accordance with the amount of change in the rotation speed so as to suppress the shock caused by rattling and to suppress the time required for shifting from becoming longer. can be suppressed, and an increase in the time required for the shift can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a schematic configuration of a vehicle to which the present invention is applied, and is a diagram for explaining main parts of a control system and control functions for various controls in the vehicle; 1 is a skeleton diagram illustrating an example of an automatic transmission; FIG. 4 is an operation chart for explaining the relationship between the shift operation of the automatic transmission and the combination of the operations of the engagement devices used therein. FIG. 4 is a diagram illustrating torque acting on each rotating element in the N range of the automatic transmission; FIG. 4 is a collinear diagram showing the state of the rotational speed of each rotating element in the N range of the automatic transmission; FIG. 4 is a diagram illustrating torque acting on each rotating element in the R range of the automatic transmission; FIG. 4 is a nomographic diagram showing the state of the rotational speed of each rotating element in the R range of the automatic transmission; 4 is a flowchart for explaining an example of control operation of shift control for switching from N range to R range while the vehicle is stopped in the electronic control unit; FIG. 9 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 8 is executed; FIG. 9 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 8 is executed, and is a diagram showing a case where the rotation speed change amount of the turbine rotation speed is larger than a preset target change amount upper limit value. FIG. 9 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 8 is executed, and is a diagram showing a case where the rotation speed change amount of the turbine rotation speed is smaller than a preset target change amount lower limit value.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining a schematic configuration of a vehicle 10 to which the present invention is applied, and is a diagram for explaining main parts of a control system for various controls in the vehicle 10. As shown in FIG. As shown in FIG. 1, the vehicle 10 includes an engine 12 as a driving force source, drive wheels 14, and a power transmission device 16 provided in a power transmission path between the engine 12 and the drive wheels 14. ing. The power transmission device 16 includes a torque converter 20 and an automatic transmission (planetary gear type automatic transmission) 22 disposed within a case 18 as a non-rotating member attached to the vehicle body. The power transmission device 16 also includes a propeller shaft 24 , a differential gear 26 and a drive shaft 28 . The propeller shaft 24 is coupled to a transmission output shaft 30, which is an output rotating member of the automatic transmission 22, so as to be able to transmit power. The differential gear 26 is connected to the propeller shaft 24 so as to be able to transmit power. The drive shaft 28 is connected to the differential gear 26 so as to be able to transmit power.

The torque converter 20 is arranged in a power transmission path between the engine 12 and the automatic transmission 22. The torque converter 20 is a hydrodynamic transmission device including a pump impeller 20p and a turbine impeller 20t. . The pump impeller 20p is an input rotating member of the torque converter 20, and is connected to the crankshaft 32 of the engine 12 so as to be able to transmit power. The turbine wheel 20t is an output rotary member of the torque converter 20, and is coupled to a transmission input shaft (input shaft) 34, which is an input rotary member of the automatic transmission 22, so as to be able to transmit power. The power transmission device 16 includes a mechanical oil pump 36 coupled to the pump impeller 20p so as to be able to transmit power. The oil pump 36 is rotationally driven by the engine 12 to discharge working oil for use in shift control of the automatic transmission 22 and for supplying lubricating oil to each part of the power transmission device 16 . That is, the hydraulic oil pumped up by the oil pump 36 is supplied as the source pressure of the hydraulic control circuit 50 provided in the vehicle 10 .

FIG. 2 is a skeleton diagram illustrating an example of the automatic transmission 22. As shown in FIG. As shown in FIG. 2, the automatic transmission 22 includes a plurality of sets of planetary gear trains including a first planetary gear train 38, a second planetary gear train 40, a third planetary gear train 42, and a fourth planetary gear train 44; A plurality of engaging devices for a first clutch C1, a second clutch C2, a third clutch C3, a fourth clutch C4, a first brake B1, and a second brake B2 are provided. In this embodiment, these plurality of engaging devices are simply referred to as engaging devices CB unless otherwise distinguished.

The engagement device CB is a hydraulic friction engagement device including a multi-plate or single-plate clutch or brake that is pressed by a hydraulic actuator, a band brake that is tightened by a hydraulic actuator, or the like. The engagement device CB is controlled by each engagement hydraulic pressure PRcb as each engagement pressure of the engagement device CB that is regulated and output from a solenoid valve or the like in the hydraulic control circuit 50, and the engagement torque, which is the torque capacity of each engagement device CB, is generated. By changing Tcb, the operating states such as the engaged state and the disengaged state are switched. Input torque input to, for example, the automatic transmission 22 between the transmission input shaft 34 and the transmission output shaft 30 without slipping the engagement device CB, i.e., without causing a differential rotation speed in the engagement device CB. In order to transmit the AT input torque Ti, a torque capacity (=engagement torque Tcb) is required to obtain the transmission torque required for each of the engagement devices CB to handle the AT input torque Ti. become. The above-mentioned transmission torque is a shared torque of the engagement device CB.

In the automatic transmission 22, each rotating element of a plurality of sets of planetary gear devices 38, 40, 42, 44 are directly or indirectly connected to each other via an engagement device CB. It is connected to the input shaft 34 , the case 18 or the transmission output shaft 30 . The rotating elements of the first planetary gear device 38 are the first sun gear S1, the carrier RCA, and the ring gear RR. Each rotating element of the second planetary gear device 40 is a second sun gear S2, a carrier RCA, and a ring gear RR. Each rotating element of the third planetary gear device 42 is a third sun gear S3, a third carrier CA3, and a third ring gear R3. Each rotating element of the fourth planetary gear device 44 is a fourth sun gear S4, a fourth carrier CA4, and a fourth ring gear R4. The first planetary gear device 38 and the second planetary gear device 40 are of a so-called Ravigneau type in which the carrier is configured by the common carrier RCA and the ring gear is configured by the common ring gear RR.

The automatic transmission 22 selectively engages the engagement device CB to selectively form a plurality of gear stages having different gear ratios γ (=AT input rotation speed Ni/AT output rotation speed No). It is a stepped transmission. The AT input rotation speed Ni is the input rotation speed of the automatic transmission 22, which is the rotation speed of the transmission input shaft 34, and can be represented by the turbine rotation speed Nt. The AT output rotation speed No is the output rotation speed of the automatic transmission 22 which is the rotation speed of the transmission output shaft 30 . The gear ratio γ of the automatic transmission 22 corresponding to each gear is the gear ratio (=number of teeth of the sun gear/number of teeth of the ring gear) ρ1, ρ2, ρ3 , ρ4 as appropriate. A gear ratio is synonymous with a gear ratio, and a gear stage is synonymous with a gear stage.

The automatic transmission 22 has 10 forward gear stages ("1st" to "10th" ), and one reverse gear stage (see "Rev" in the figure) are selectively formed. Further, the automatic transmission 22 may be placed in a neutral state by releasing both of the engagement devices CB, for example. It is in a neutral state (see "N" in the figure). A neutral state of the automatic transmission 22 is a state in which power transmission in the automatic transmission 22 is interrupted, that is, a state in which the automatic transmission 22 cannot transmit power. The gear ratio γ is greatest at the first gear stage, and decreases toward the tenth gear stage, which is on the high side. The engagement operation table in FIG. 3 summarizes the relationship between each gear stage formed in the automatic transmission 22 and each operation state of the engagement device CB. A blank indicates a released state.

The automatic transmission 22 is controlled by an electronic control device (control device) 100 (see FIG. 1), which will be described later, in accordance with the driver's accelerator operation, vehicle speed V, etc. is switched, the gear shift is performed. For example, when the electronic control unit 100 upshifts from the first gear to the second gear, as shown in the engagement operation table of FIG. A so-called clutch-to-clutch shift is performed by disengaging and engaging the first brake B1, which is the engagement-side frictional engagement device. At this time, the release transitional hydraulic pressure of the second clutch C2 and the engagement transitional hydraulic pressure of the first brake B1 are regulated. A predetermined engagement device among the engagement devices CB is an engagement device involved in shifting of the automatic transmission 22 . The disengagement-side frictional engagement device is an engagement device among predetermined engagement devices that is in an engaged state before the shift of the automatic transmission 22, and is switched to the disengaged state when the automatic transmission 22 shifts the shift. That is, the engagement device controlled from the engaged state toward the disengaged state when the automatic transmission 22 shifts. The engagement-side friction engagement device is an engagement device that is in a disengaged state before shifting of the automatic transmission 22 among predetermined engagement devices, and is brought into an engaged state when the automatic transmission 22 shifts. It is an engagement device that can be switched, that is, an engagement device that is controlled from a disengaged state to an engaged state when the automatic transmission 22 shifts.

Returning to FIG. 1, the vehicle 10 includes an electronic control device 100 as a controller including control devices related to shift control of the automatic transmission 22, for example. The electronic control unit 100 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, and an input/output interface. Various controls of the vehicle 10 are executed by performing signal processing.

The electronic control unit 100 includes various signals (for example, An operation position POSsh of a shift lever 52 as a provided shift operation member, an AT input rotation speed Ni (=turbine rotation speed Nt), an AT output rotation speed No corresponding to the vehicle speed V, etc.) are supplied respectively.

Various command signals (eg, hydraulic control command signal Sat for controlling the operating state of the engagement device CB) are sent from the electronic control unit 100 to each device (eg, the hydraulic control circuit 50) provided in the vehicle 10. are supplied respectively. This hydraulic control command signal Sat is, for example, a command signal for driving each solenoid valve or the like in the hydraulic control circuit 50 for regulating each engagement hydraulic pressure PRcb supplied to each hydraulic actuator of the engagement device CB. This hydraulic control command signal Sat is also a command signal for controlling the shift of the automatic transmission 22 . The electronic control unit 100 sets an instruction hydraulic pressure corresponding to the value of each engagement hydraulic pressure PRcb supplied to each hydraulic actuator in order to obtain the target engagement torque Tcb of the engagement device CB. The drive current or drive voltage thus obtained is output to the hydraulic control circuit 50 .

The shift lever 52 is an operating device for manually selecting a plurality of types of shift ranges in the automatic transmission 22 . The shift lever 52 is operated by the driver to the operating position POSsh corresponding to the shift range of the automatic transmission 22 . The operating position POSsh includes, for example, P, R, N, and D operating positions.

The P operating position is a parking operating position that selects a parking mode (=P range) of the automatic transmission 22, in which the automatic transmission 22 is in a neutral state and rotation of the transmission output shaft 30 is mechanically prevented. . The R operation position is a reverse travel operation position for selecting a reverse travel mode (=R range) of the automatic transmission 22 that enables the vehicle 10 to travel in reverse. The N operating position is a neutral operating position for selecting the neutral mode (=N range) of the automatic transmission 22 in which the automatic transmission 22 is in the neutral state. The D operation position is a forward travel operation position for selecting a forward travel mode (=D range) of the automatic transmission 22 that allows the vehicle 10 to travel forward.

The electronic control unit 100 includes shift control means, that is, a shift control section 110 in order to implement various controls in the vehicle 10 . Shift control unit 110 executes shift control of automatic transmission 22 . For example, the shift control unit 110 outputs to the hydraulic control circuit 50 a hydraulic control command signal Sat for switching the operating state of the engagement device CB so as to switch the shift range of the automatic transmission 22 based on the operating position POSsh. In the case of the D range, shift control unit 110 uses a predetermined relationship, such as a shift map, to determine whether or not it is necessary to change the gear stage of automatic transmission 22, and shifts to that gear stage. When it is determined that switching is necessary, the hydraulic control command signal Sat for switching the operating state of the engagement device CB is output to the hydraulic control circuit 50 so as to switch the gear stage of the automatic transmission 22. do.

By the way, inside the automatic transmission 22, there is backlash (also referred to as backlash), which is a gap between two mutually acting parts in the rotational direction. Depending on the difference in the shift range of the automatic transmission 22 and the difference in the gear position of the automatic transmission 22, the same parts may be loose in different directions or may not be loose. Therefore, during shift control of the automatic transmission 22, the direction in which the backlash is formed between certain parts changes, or the state in which the backlash is not clogged changes to the state in which the backlash is clogged. At this time, there is a possibility that a shock will occur due to the torque generated by rattling (=tooth striking) due to clogging of backlash. As for the direction in which backlash is created, for example, when the forward rotation direction of the vehicle 10 is assumed to be forward rotation, the backlash in which backlash is created by torque acting in the forward rotation direction is defined as the positive side. In addition, in this embodiment, the shock caused by hitting with looseness is referred to as hitting shock.

On the other hand, in the shift control of the automatic transmission 22, the instructed oil pressure for the engagement-side frictional engagement device is, for example, a value corresponding to the AT input torque Ti, and is a value that takes into account the suppression of shift shock and shift time. set. In this embodiment, the indicated hydraulic pressure set to such a value is referred to as a normal indicated hydraulic pressure. At the time of shift control of the automatic transmission 22, for example, by increasing the instructed hydraulic pressure more slowly than the normal instructed hydraulic pressure to gently engage the engagement-side frictional engagement device, the rattling shock as described above is suppressed. can be considered. However, if the engagement-side frictional engagement device is loosely engaged, there is a possibility that progress of gear shifting will be stagnant, leading to deterioration of drivability.

In the present embodiment, during shift control of the automatic transmission 22, instead of gently engaging the engagement-side frictional engagement device, the instructed hydraulic pressure of the engagement-side frictional engagement device is kept at the normal instructed hydraulic pressure. Then, by temporarily reducing the torque capacity of an engagement device other than the engagement-side frictional engagement device, rattling shock is suppressed. The control will be described in detail below.

FIG. 4 is a diagram for explaining the torque acting on each rotating element in the N range of the automatic transmission 22. As shown in FIG. FIG. 5 is a nomographic diagram showing the state of the rotational speed of each rotating element in the N range of the automatic transmission 22. As shown in FIG. FIG. 6 is a diagram for explaining torque acting on each rotating element in the R range of the automatic transmission 22. As shown in FIG. FIG. 7 is a collinear diagram showing the state of the rotational speed of each rotating element in the R range of the automatic transmission 22. As shown in FIG. 4 to 7, in the case where the automatic transmission 22 alone is in a state where there is no load from the road surface such as the vehicle weight, the AT input torque Ti is applied so as to maintain a constant AT input rotation speed Ni ( "Input" in the figure) is exemplified.

In FIGS. 4 and 6, the arrows on the skeleton diagram of the automatic transmission 22 indicate the direction of torque acting on each rotating element. The direction of the clockwise arrow is the positive side. 4 and 6, the lower half of the axis of the transmission input shaft 34 is omitted from the skeleton diagram of the automatic transmission 22 shown in FIG.

The nomographic charts shown in FIGS. 5 and 7 respectively represent the relative relationship between the rotational speeds of the rotating elements in the automatic transmission 22 . 5 and 7, nine vertical lines Y1-Y9 correspond to the nine rotating elements of the automatic transmission 22. As shown in FIG. A vertical line Y1 is an axis representing the rotation speed of the first sun gear S1 corresponding to the first rotation element RE1. A vertical line Y2 is an axis representing the rotational speed of the carrier RCA corresponding to the second rotational element RE2. A vertical line Y3 is an axis representing the rotation speed of the ring gear RR corresponding to the third rotation element RE3. A vertical line Y4 is an axis representing the rotation speed of the second sun gear S2 corresponding to the fourth rotation element RE4. A vertical line Y5 is an axis representing the rotation speed of the third ring gear R3 corresponding to the fifth rotation element RE5. A vertical line Y6 is an axis representing the rotation speed of the third carrier CA3 corresponding to the sixth rotation element RE6. A vertical line Y7 is an axis representing the rotational speed of the interconnected third sun gear S3 and fourth sun gear S4 corresponding to the seventh rotating element RE7. A vertical line Y8 is an axis representing the rotational speed of the fourth carrier CA4 corresponding to the eighth rotational element RE8. A vertical line Y9 is an axis representing the rotation speed of the fourth ring gear R4 corresponding to the ninth rotation element RE9. The second rotating element RE2 and the eighth rotating element RE8 are connected to the transmission input shaft 34 (see "in" in the drawing), and the sixth rotating element RE6 is connected to the transmission output shaft 30. (See "out" in the figure). Further, the third rotating element RE3 and the seventh rotating element RE7 are selectively connected via the first clutch C1, and the fourth rotating element RE4 and the seventh rotating element RE7 are connected via the second clutch C2. The third rotating element RE3 and the fifth rotating element RE5 are selectively connected via the third clutch C3, and the sixth rotating element RE6 and the ninth rotating element RE9 are selectively connected via the fourth clutch C3. C4, the first rotating element RE1 is selectively connected to the case 18 via the first brake B1, and the fifth rotating element RE5 is selectively connected to the case 18 via the second brake B2. selectively coupled.

4 and 5, in the N range of the automatic transmission 22, the second clutch C2 and the second brake B2 are engaged. In the automatic transmission 22, even if the second clutch C2 and the second brake B2 are engaged, the N range is established if the first clutch C1 or the third clutch C3 is disengaged. In the N range of the automatic transmission 22, the second clutch C2 and the second brake B2 are engaged in advance in preparation for forming the first gear stage or the reverse gear stage, for example. In the N range of the automatic transmission 22 as described above, if there is no load from the road surface, the drag of the engagement device in the disengaged state generates a torque for forward rotation of the transmission output shaft 30 . Therefore, the backlash at the spline fitting portion between the second brake B2 and the case 18 is on the positive side.

On the other hand, in FIGS. 6 and 7, in the R range of the automatic transmission 22, the second clutch C2, the third clutch C3, and the second brake B2 are engaged. In the R range of the automatic transmission 22, the backlash at the spline fitting portion between the second brake B2 and the case 18 is reduced to the negative side by the torque acting on each rotating element. Accordingly, during shift control for switching the automatic transmission 22 from the N range to the R range, the direction of backlash is reversed from the positive side to the negative side, and backlash occurs. In the R range, the engagement of the third clutch C3 makes the third rotating element RE3 and the fifth rotating element RE5 integral, so the inertia coupled to the case 18 increases due to the engagement of the second brake B2. Therefore, when the automatic transmission 22 is controlled to switch from the N range to the R range, there is a possibility that a large rattling shock may occur.

When the electronic control unit 100 performs shift control to switch the automatic transmission 22 from the N range to the R range while the vehicle is stopped, the electronic control unit 100 controls the engagement pressure of the second brake B2 that is in the engaged state, that is, the pressure of the second brake B2. The instructed hydraulic pressure Pb2 is temporarily set to a release standby pressure (standby pressure) Pr lower than the instructed hydraulic pressure Pb2 before the shift control (before the shift) during a shift transition, and the second brake B2 is placed in a slip state (=half-engaged state). do. As a result, transmission of torque generated by rattling is reduced, and rattling shock can be suppressed. In the shift control for switching the automatic transmission 22 from the N range to the R range while the vehicle is stopped, the instructed oil pressure Pc3 of the third clutch C3 is a value corresponding to, for example, the AT input torque Ti. is set to a value that considers As a result, it is possible to prevent stagnation of gear shifting caused by a delay in switching to the engaged state of the third clutch C3. That is, the electronic control unit 100 temporarily releases the instructed oil pressure Pb2 of the engaged second brake B2 during shift control to switch the automatic transmission 22 from the N range to the R range while the vehicle is stopped. In order to lower the standby pressure Pr, the shift control unit 110 includes an NR switching determination unit 112, a first hydraulic control unit 114, a backlash determination unit 116, a storage unit 118, a second hydraulic control unit 120, and a learning control unit 122 .

The NR switching determination unit 112 determines whether or not shift control has been started to switch the automatic transmission 22 from the N range to the R range while the vehicle is stopped. For example, the NR switching determination unit 112 determines that the vehicle speed V [km/h] detected by the output rotation speed sensor 106 is zero and the operation position POSsh detected by the operation position sensor 102 is changed from the N operation position to the R operation. When it is switched to the position, it is determined that shift control has started to switch the automatic transmission 22 from the N range to the R range while the vehicle is stopped.

When the NR switching determination unit 112 determines that the shift control for switching from the N range to the R range is started while the vehicle is stopped, the shift control unit 110 controls the fifth rotating element (predetermined rotating element ) in the engaged state of the second brake (frictional engagement device for reaction force) B2 and the second clutch C2 connected to RE5, the third rotating element (another rotating element) RE3 different from the fifth rotating element RE5 In order to engage the coupled third clutch (engagement side frictional engagement device) C3, the indicated hydraulic pressure Pb2 [Pa] for the second brake B2, the indicated hydraulic pressure Pc2 [Pa] for the second clutch C2, and the 3 control the command oil pressure Pc3 [Pa] of the clutch C3. Note that in shift control for switching from the N range to the R range while the vehicle is stopped, the indicated hydraulic pressure Pc2 for the second clutch C2 is constant, for example, from before the shift to after the shift.

When the NR switching determination unit 112 determines that shift control for switching from the N range to the R range is started while the vehicle is stopped, the first hydraulic pressure control unit 114 controls the instructed hydraulic pressure Pc3 [Pa] of the third clutch C3. . For example, as shown in FIG. 9, when the NR switching determination unit 112 determines that shift control for switching from the N range to the R range has started while the vehicle is stopped, the first hydraulic control unit 114 switches the third clutch C3. A quick fill is executed to temporarily increase the instructed hydraulic pressure Pc3 to the preset first instructed hydraulic pressure Pc3A [Pa]. Further, when the quick fill is completed, the first hydraulic pressure control unit 114 causes the command hydraulic pressure Pc3 of the third clutch C3 to wait at the preset second command hydraulic pressure Pc3B [Pa] for a predetermined time tA [sec]. Further, after the predetermined time tA has elapsed, the first hydraulic pressure control unit 114 increases the instructed hydraulic pressure Pc3 for the third clutch C3 from the second instructed hydraulic pressure Pc3B at a predetermined rate of increase.

When the NR switching determination section 112 determines that shift control for switching from the N range to the R range is started while the vehicle is stopped, the backlash determining section 116 determines whether or not backlash has occurred. For example, as shown in FIGS. 9 to 11, the backlash determining unit 116 determines that the input rotation speed Turbine rotation speed Nt [rpm] detected by sensor 104, that is, turbine rotation speed N0 [rpm] decreases, and it is determined that the lowered turbine rotation speed Nt is constant for preset time tB [sec]. Then, it is determined that rattling has occurred. It should be noted that the time tB [sec] is determined, for example, by an experiment or the like. The time is set to be sufficiently shorter than the time in which the turbine rotation speed Nt [rpm] temporarily stops changing after the backlash is eliminated. That is, as shown in FIGS. 9 to 11, the turbine rotational speed Nt [rpm] when backlash occurs (at time t2) and when the backlash determining unit 116 determines that backlash has occurred (at time t3) ) is the same as the turbine rotation speed Nt [rpm].

The storage unit 118 stores a preset release standby pressure Pr [Pa]. When the NR switching determination unit 112 determines that shift control for switching from the N range to the R range has started while the vehicle is stopped, the second hydraulic pressure control unit 120 controls the instructed hydraulic pressure Pb2 [Pa] of the second brake B2. . For example, when the NR switching determination unit 112 determines that shift control for switching from the N range to the R range has started while the vehicle is stopped, the second hydraulic control unit 120 switches the second brake B2 as shown in FIG. The instructed hydraulic pressure Pb2 is obtained from the instructed hydraulic pressure (engagement pressure) Pb2A [Pa] of the second brake B2 before the shift control is started (before the shift), that is, the instructed hydraulic pressure (engagement pressure) Pb2A [Pa]. Pa], and the instructed hydraulic pressure Pb2 for the second brake B2 is kept at the release standby pressure Pr. Further, when the backlash determination unit 116 determines that backlash has occurred in a state in which the instructed hydraulic pressure Pb2 of the second brake B2 is kept at the release standby pressure Pr, the second hydraulic pressure control unit 120 determines backlash. After a predetermined time tC [sec] has passed since it was determined that backlash has occurred in the unit 116, the instructed oil pressure Pb2 for the second brake B2 is increased from the release standby pressure Pr at a predetermined rate of increase before the shift control is started. The hydraulic pressure is increased to the indicated hydraulic pressure Pb2A [Pa] for the second brake B2.

The learning control unit 122 is provided with a rotation change amount calculation unit 122a. When the backlash determination unit 116 determines that backlash has occurred, the rotation change amount calculation unit 122a calculates the rotational speed of the transmission input shaft 34 at the start of shift control for switching from the N range to the R range while the vehicle is stopped. and the rotation speed of the transmission input shaft 34 when the backlash of the spline fitting portion between the second brake B2 and the case 18 is eliminated. For example, the rotation change amount calculation unit 122a calculates the turbine rotation speed detected by the input rotation speed sensor 104 when the NR switching determination unit 112 determines that shift control for switching from the N range to the R range has started while the vehicle is stopped. From the difference (N0-NG) between N0 [rpm] and the turbine rotation speed NG [rpm] detected by the input rotation speed sensor 104 when the backlash determination unit 116 determines that backlash has occurred, A rotation speed change amount ΔNt [rpm] of the turbine rotation speed Nt is calculated.

When the rotation speed change amount ΔNt [rpm] of the turbine rotation speed Nt is calculated by the rotation change amount calculation unit 122a, the learning control unit 122 stores in the storage unit 118 according to the calculated rotation speed change amount ΔNt. The value Pr _N [Pa] of the release standby pressure Pr is learned, that is, changed. Note that the learning control unit 122, for example, when the command hydraulic pressure Pb2 of the second brake B2 is increased from the release standby pressure Pr by the second hydraulic control unit 120, or after the gear shift is completed, the learning control unit 122 controls the release standby pressure stored in the storage unit 118. The value Pr _N [Pa] of the pressure Pr is learned.

For example, as shown in FIG. 10, the learning control unit 122 determines that the rotation speed change amount ΔNt [rpm] calculated by the rotation change amount calculation unit 122a is greater than a preset target change amount upper limit value ΔNt_tg_max [rpm] (ΔNt >ΔNt_tg_max), and the value _PrN of the standby release pressure Pr stored in the storage unit 118 is learned, that is, changed so that the value _PrN of the standby release pressure Pr stored in the storage unit 118 becomes smaller. Note that the target change amount upper limit value ΔNt_tg_max is the rotation speed change amount measured when the rattling shock at the time of rattling is suppressed and the time required for shifting is suppressed, for example, by experiment or the like. This is the upper limit value of ΔNt [rpm], and is a determination value for determining whether or not the torque capacity of the second brake B2 is relatively high when the instructed oil pressure Pb2 is lowered to the release standby pressure Pr [Pa]. . That is, as shown in FIG. 10, when the rotation speed change amount ΔNt is greater than the target change amount upper limit value ΔNt_tg_max, the learning control unit 122 calculates the learning value Prl[ Pa], and subtracts the learning value Prl from the value _PrN of the standby release pressure Pr stored in the storage unit 118 to learn the value PrN of the standby release pressure Pr to the value _{PrN +1} (PrN ₊₁ = _PrN -Prl) or change. Note that the value Pr _N is the value of the standby release pressure Pr pre-stored in the storage unit 118, and the value Pr _N+1 is the value of the standby release pressure Pr after learning. Further, "G" shown in Equation (1) is a conversion coefficient, which is set in advance by experiment or the like, for converting the rotation speed change amount ΔNt [rpm] to the learned value Prl [Pa].
Prl=ΔNt×G (1)

Further, for example, the learning control unit 122 controls that the rotation speed change amount ΔNt [rpm] calculated by the rotation change amount calculation unit 122a is smaller than a preset target change amount lower limit value ΔNt_tg_min [rpm] as shown in FIG. (ΔNt<ΔNt_tg_min) and the value Pr _{N [Pa] of the standby release pressure Pr stored in the storage unit 118 is learned, that is, changed so that the value Pr N [} Pa] of the standby pressure for release stored in the storage unit 118 increases. Note that the target change amount lower limit value ΔNt_tg_min is the rotation speed change amount measured when the rattling shock at the time of rattling is suppressed and the length of time required for shifting is suppressed, for example, by experiment or the like. This is the lower limit value of ΔNt [rpm], and is a determination value for determining whether or not the torque capacity of the second brake B2 is relatively low when the instructed oil pressure Pb2 is lowered to the release standby pressure Pr [Pa]. That is, when the rotation speed change amount ΔNt is smaller than the target change amount lower limit value ΔNt_tg_min as shown in FIG. The learning value Prl is added to the value _PrN of the release standby pressure Pr stored in the storage unit 118, and the value _PrN of the release standby pressure Pr is learned to the value PrN ₊₁ (PrN ₊₁ = _PrN +Prl), that is, changed. 10 and 11, the turbine rotation speed Nt indicated by the dashed line L is the turbine rotation speed Nt when the backlash impact is suppressed and the length of time required for shifting is suppressed. It is a line which virtually shows the behavior of the rotation speed Nt.

Further, for example, the learning control unit 122 determines that the rotation speed change amount ΔNt [rpm] calculated by the rotation change amount calculation unit 122a is equal to or less than the target change amount upper limit value ΔNt_tg_max [rpm] and the target change amount lower limit value ΔNt_tg_min [rpm]. ] or more (ΔNt≦ΔNt_tg_max, ΔNt≧ΔNt_tg_min), the value _PrN of the release standby pressure Pr stored in the storage unit 118 is not changed. That is, the learning control unit 122 calculates that the learning value Prl [Pa] is zero when the rotation speed change amount ΔNt is equal to or less than the target change amount upper limit value ΔNt_tg_max and is equal to or more than the target change amount lower limit value ΔNt_tg_min (Prl= 0), and the learning value Prl, that is, zero is added to the value _PrN of the standby release pressure Pr stored in the storage unit 118 to learn the value PrN of the standby release pressure Pr to the value _{PrN +1} (PrN ₊₁ = _PrN +Prl) ie change.

FIG. 8 is a flowchart for explaining an example of a control operation of shift control for switching from the N range to the R range while the vehicle is stopped, for example, in the electronic control unit 100 . 9 to 11 are examples of time charts when the control operation shown in the flowchart of FIG. 8 is executed. Further, at time t1 shown in FIG. 9, the NR switching determination unit 112 determines that shift control for switching the automatic transmission 22 from the N range to the R range has started while the vehicle is stopped.

First, in step S10 corresponding to the function of the second hydraulic control unit 120 (step will be omitted hereinafter), the instructed hydraulic pressure Pb2 of the second brake B2 is reduced to the release standby pressure Pr stored in the storage unit 118. Next, in S20 corresponding to the function of the first hydraulic pressure control section 114, the instructed hydraulic pressure Pc3 for the third clutch C3 is temporarily increased to the first instructed hydraulic pressure Pc3A. is kept on standby at the second command oil pressure Pc3B. Next, in S30 corresponding to the function of the first hydraulic control unit 114, the instructed hydraulic pressure Pc3 for the third clutch C3 is increased from the second instructed hydraulic pressure Pc3B at a predetermined rate of increase.

Next, in S40 corresponding to the function of the backlash determining section 116, it is determined whether or not backlash has occurred. If the determination in S40 is negative, S40 is executed again, but if the determination in S40 is positive (time t3 in FIGS. 9 to 11), the function of the rotation change amount calculation unit 122a is performed. S50 is executed. 9 to 11 is when the spline fitting portion between the second brake B2 and the case 18 is tightened and rattling occurs. In S50, a rotation speed change amount ΔNt of the turbine rotation speed Nt is calculated.

Next, in S60 corresponding to the function of the learning control unit 122, it is determined whether or not the rotation speed change amount ΔNt calculated in S50 is greater than the target change amount upper limit value ΔNt_tg_max. If the determination in S60 is affirmative, that is, if the rotation speed change amount ΔNt is greater than the target change amount upper limit value ΔNt_tg_max, S70 corresponding to the function of the learning control unit 122 is executed. If the determination in S60 is negative, S80 corresponding to the function of the learning control section 122 is executed. At S70, a learning value Prl is calculated from the rotation speed change amount ΔNt calculated at S50. Next, in S90 corresponding to the function of the learning control unit 122, the learning value Prl is subtracted from the value _PrN of the release standby pressure Pr stored in the storage unit 118, and the value _PrN of the release standby pressure Pr becomes the value Pr. _N+1 is trained (Pr _N+1 =Pr _N -Prl).

In S80, it is determined whether or not the rotation speed change amount ΔNt calculated in S50 is smaller than the target change amount lower limit value ΔNt_tg_min. If the determination in S80 is affirmative, that is, if the rotation speed change amount ΔNt is smaller than the target change amount lower limit value ΔNt_tg_min, S100 corresponding to the function of the learning control unit 122 is executed. If the determination in S80 is negative, that is, if the rotation speed change amount ΔNt is equal to or less than the target change amount upper limit value ΔNt_tg_max and is equal to or more than the target change amount lower limit value ΔNt_tg_min, S110 corresponding to the function of the learning control unit 122 is executed. executed.

At S100, a learning value Prl is calculated from the rotation speed change amount ΔNt calculated at S50. Next, in S120 corresponding to the function of the learning control unit 122, the learning value Prl is added to the value _PrN of the release standby pressure Pr stored in the storage unit 118, and the value _PrN of the release standby pressure Pr becomes the value Pr. _N+1 is trained (Pr _N+1 =Pr _N +Prl).

At S110, the learning value Prl is calculated from the rotation speed change amount ΔNt calculated at S50, that is, the learning value Prl is calculated to be zero (Prl=0) from the rotation speed change amount ΔNt calculated at S50. Next, in S130 corresponding to the function of the learning control unit 122, the value _PrN of the standby release pressure Pr is obtained by adding the learning value Prl, that is, zero to the value _PrN of the standby release pressure Pr stored in the storage unit 118. The value Pr _N+1 is learned (Pr _N+1 =Pr _N +Prl).

As described above, according to the electronic control device 100 of the automatic transmission 22 of the present embodiment, the second brake B2 is applied to the pre-shift control during the transition of the shift control from the N range to the R range while the vehicle is stopped. A release standby pressure Pr that is temporarily lower than the instructed hydraulic pressure Pb2A is set, and the release standby pressure Pr is determined by the turbine rotational speed N0 of the transmission input shaft 34 of the automatic transmission 22 at the start of the shift and the internal pressure of the automatic transmission 22. Learning is performed according to the rotation speed change amount ΔNt from the turbine rotation speed NG of the transmission input shaft 34 when the backlash is reduced. Therefore, the release standby pressure Pr is learned in accordance with the rotation speed change amount ΔNt so as to suppress the shock at the time of rattling and to suppress the time required for shifting from becoming long. It is possible to suppress the time shock and to suppress the increase in the time required for the speed change.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is also applicable to other aspects.

For example, in the above-described embodiment, the automatic transmission 22 has 10 forward gear stages, but the present invention is not limited to this aspect. For example, the automatic transmission 22 may be an automatic transmission in which a plurality of gear stages are selectively formed.

Further, in the above-described embodiment, the engine 12 is illustrated as the driving force source of the vehicle 10, but the present invention is not limited to this aspect. For example, the driving force source may employ another prime mover such as an electric motor alone or in combination with the engine 12 . Further, although the power of the engine 12 is transmitted to the automatic transmission 22 via the torque converter 20 as a hydrodynamic transmission device, the present invention is not limited to this aspect. For example, instead of the torque converter 20, another hydrodynamic transmission such as a hydrocoupling that does not amplify torque may be used. Alternatively, this hydrodynamic transmission may not necessarily be provided.

It should be noted that what has been described above is just one embodiment, and the present invention can be implemented in aspects with various modifications and improvements based on the knowledge of those skilled in the art.

22: Automatic transmission (planetary gear type automatic transmission)
34: Transmission input shaft (input shaft)
100: Electronic control device (control device)
112: NR switching determination unit 116: backlash determination unit 120: second hydraulic control unit 122: learning control unit 122a: rotation change amount calculation unit B2: second brake (friction engagement device for reaction force)
C3: Third clutch (engagement side friction engagement device)
NG, N0: Turbine rotation speed (rotation speed)
Pb2A: Command oil pressure (engagement pressure)
Pr: release standby pressure (standby pressure)
RE3: Third rotating element (another rotating element)
RE5: fifth rotating element (predetermined rotating element)
ΔNt: Amount of rotation speed change

Claims (1)

In the engaged state of the reaction force frictional engagement device connected to a predetermined rotating element that bears the reaction force associated with gear shifting, the engagement side frictional engagement connected to another rotating element different from the predetermined rotating element A control device for a planetary gear type automatic transmission in which the speed change is performed by engaging a device,
The reaction force friction engagement device is set to a standby pressure temporarily lower than the engagement pressure before the gear shift during the transition of the gear shift,
The standby pressure is determined according to the rotational speed change amount between the rotational speed of the input shaft of the automatic transmission at the start of the shift and the rotational speed of the input shaft when the internal play of the automatic transmission is eliminated. A control device for a planetary gear type automatic transmission characterized by being made to learn.

Images