JP7231478B2 - Gear control device for continuously variable transmission - Google Patents

Description

The present invention relates to a shift control device for a continuously variable transmission mounted on a vehicle.

2. Description of the Related Art In recent years, belt-type continuously variable transmissions (CVTs) have been widely put into practical use as automatic transmissions for vehicles, which are capable of steplessly changing the gear ratio, eliminating gear shift shock, and improving fuel efficiency. Here, the belt-type continuously variable transmission has a primary pulley (drive pulley) provided on the input shaft, a secondary pulley (driven pulley) provided on the output shaft, and a belt stretched over these pulleys. , the gear ratio is changed steplessly by changing the groove width of each pulley to change the winding diameter of the belt. Belts include, for example, chains, metal belts, and dry composite belts.

In such a continuously variable transmission, for example, a target gear ratio is set according to parameters indicating the operating state of the vehicle, such as accelerator opening and vehicle speed (or engine speed), and the gear ratio is controlled. At that time, the deviation (error) between the target gear ratio and the actual gear ratio is subjected to, for example, proportional processing and integral processing, and feedback (F/B) control is performed so that the actual gear ratio matches the target gear ratio. .

By the way, strictly speaking, continuously variable transmissions have variations in hardware for each individual, and there are physically possible full overdrive (full OD: lower limit of gear ratio) and full low (full Low: upper limit of gear ratio). is different, for example, if integral F/B is performed up to the theoretical full OD, F/B control is continued despite the physical limit (transmission ratio limit), and the value of the integral term is unnecessarily increased It may accumulate, for example, causing a problem such as a shift delay occurring when downshifting.

In order to solve such a problem, for example, in Patent Document 1, when the gear ratio shifts to near full OD or full Low, integration processing is prohibited to prevent the accumulation of integral values. A technique (shift control method for a continuously variable transmission) for preventing the integral value from becoming an abnormal value has been disclosed.

More specifically, in the shift control method for a continuously variable transmission described in Patent Document 1, the error between the target engine speed and the actual engine speed is proportionally and integrally processed to change the gear ratio. The control means prohibits integration processing when the actual gear ratio shifts to the vicinity of the gear ratio limit value in the intermediate gear ratio region defined by the gear ratio limit value set in advance by the control means. Shift control is performed to change the gear ratio, and when shifting the actual gear ratio near the gear ratio limit value to the intermediate gear ratio region side, shift control is performed to allow integration processing and change the gear ratio.

JP-A-3-249464

By the way, as described above, in the technique described in Patent Document 1, integration F/B is prohibited in the vicinity of the gear ratio limit value in order to avoid accumulation of unnecessary integral terms. , the gear ratio is set to prohibit integral F/B with a margin in accordance with the worst case (individual with the largest variation). A state where the full OD cannot be used may occur.

The present invention has been made to solve the above problems. To provide a shift control device for a continuously variable transmission that enables shifting to (that is, enabling shifting to full OD and/or full Low that each individual can physically take) With the goal.

A gear shift control device for a continuously variable transmission according to the present invention performs feedback control based on a deviation between a target gear ratio and an actual gear ratio, controls the actual gear ratio to match the target gear ratio, and controls the actual gear ratio. Accumulation of an integral term that adjusts the control value in response to the time integral of the deviation between the target transmission ratio and the actual transmission ratio when the ratio is between the target transmission ratio limit value and the integral F/B stop transmission ratio. shift control means for stopping the operation; learning condition determination means for determining that the learning condition is established when the actual gear ratio reaches the integral F/B stop gear ratio; and the learning condition is established. is determined, the target gear ratio is requested to be changed further toward the target gear ratio limit value side than the integral F/B stop gear ratio, and the actual gear ratio is changed toward the target gear ratio limit value side. a learning value acquisition means for acquiring the actual gear ratio when the gear ratio is lost, changing the integral F/B stop gear ratio based on the actual gear ratio, and acquiring the integral F/B stop gear ratio after learning; and the shift control means controls the execution or stop of the integration term accumulation operation using the learned integral F/B stop gear ratio.

According to the shift control device for a continuously variable transmission according to the present invention, when the actual gear ratio has reached the integral F/B stop gear ratio, it is determined that the learning condition is established, and the learning condition is established. If it is determined that the target gear ratio is determined as An actual gear ratio at the time when it is lost is acquired, and based on the actual gear ratio, the integral F/B stop gear ratio is changed, and the integral F/B stop gear ratio after learning is acquired. Then, execution or stop of the operation of accumulating the integral term is controlled using the learned integral F/B stop gear ratio. That is, by learning the integral F/B prohibition gear ratio in accordance with the individual (continuously variable transmission), the integral F/B is adjusted to the limit gear ratio of the individual (that is, in accordance with the variation of each individual). Since the B stop gear ratio can be set (corrected), accumulation of unnecessary integral terms can be prevented and the physical limit gear ratio of each individual can be used up. As a result, irrespective of the hardware variation of each individual continuously variable transmission, each individual can shift to the OD side and/or the Low side up to the hardware limit (that is, each individual physically takes). full OD and/or shifting to full Low).

In the shift control device for a continuously variable transmission according to the present invention, the target gear ratio limit value is a lower limit value of the target gear ratio and/or an upper limit value of the target gear ratio, and the integral F/B stop gear ratio is set for each target transmission ratio lower limit value and/or target transmission ratio upper limit value.

In this case, since the integral F/B stop gear ratio is set for each of the target gear ratio lower limit (full OD) and/or the target gear ratio upper limit (full Low), the full OD and/or Alternatively, the integrated F/B stop gear ratio can be learned and set for each full Low. Therefore, it is possible to shift to full OD and/or full Low.

In the shift control device for a continuously variable transmission according to the present invention, the integral F/B stop gear ratio is set according to the target secondary pulley pressure and the input torque of the continuously variable transmission, and the learning value acquisition means is , acquire the actual gear ratio, target secondary pulley pressure, and input torque when the actual gear ratio no longer changes toward the target gear ratio limit value side, and based on the actual gear ratio, target secondary pulley pressure, and input torque, It is preferable to change the integral F/B stop gear ratio to obtain the learned integral F/B stop gear ratio.

In this case, the integral F/B stop gear ratio is set according to the target secondary pulley pressure of the continuously variable transmission and the input torque, and the actual gear ratio when the actual gear ratio stops changing to the target gear ratio limit value side is set. Gear ratio, target secondary pulley pressure, and input torque are acquired, and based on the actual gear ratio, target secondary pulley pressure, and input torque, integral F/B stop gear ratio is changed, and integrated F/B stop after learning is performed. A gear ratio is obtained. Therefore, it is possible to obtain and learn the integral F/B stop gear ratio appropriately according to parameters such as the actual gear ratio, the target secondary pulley pressure, and the input torque.

Further, a shift control device for a continuously variable transmission according to the present invention is an integral F/B stop shift that defines a relationship between a target secondary pulley pressure of the continuously variable transmission, an input torque, and an integral F/B stop gear ratio. Storage means for storing the ratio map is further provided, and the integral F/B obtained by searching the integral F/B stop gear ratio map using the target secondary pulley pressure and the input torque obtained by the learning value obtaining means. The difference between the stop gear ratio and the acquired actual gear ratio is used as the learning value of the integral F/B stop gear ratio, and the learned value is used as the offset value for the map search value of the integral F/B stop gear ratio during normal control. , to obtain the integrated F/B stop gear ratio after learning.

In this case, an integral F/B stop gear ratio map that defines the relationship between the target secondary pulley pressure of the continuously variable transmission, the input torque, and the integral F/B stop gear ratio is stored. The difference between the integral F/B stop gear ratio obtained by retrieving the integral F/B stop gear ratio map using the pulley pressure and the input torque and the obtained actual gear ratio is the integral F/B A learned value of the stop gear ratio is added as an offset value to the map search value of the integral F/B stop gear ratio during normal control to obtain the integral F/B stop gear ratio after learning. Therefore, the map can be used to obtain the integral F/B stop gear ratio, and the learned value can be reflected in the integral F/B stop gear ratio.

In the shift control device for a continuously variable transmission according to the present invention, the learning condition determination means determines that the actual gear ratio has reached the integral F/B stop gear ratio, and that the vehicle speed and the oil temperature of the continuously variable transmission , the input torque, and the secondary pulley pressure are within a first predetermined range, and the fluctuation width of the parameter is within a second predetermined range Also, it is preferable to determine that the learning condition is satisfied.

In this case, in addition to the fact that the actual gear ratio has reached the integral F/B stop gear ratio, at least one of the vehicle speed, the oil temperature of the continuously variable transmission, the input torque, and the secondary pulley pressure is within a first predetermined range and the fluctuation width of the parameter is within a second predetermined range, it is determined that the learning condition is satisfied. Therefore, it is possible to more accurately determine whether or not the learning condition is satisfied (that is, whether or not the learning process can be executed).

According to the present invention, irrespective of hardware variations among individuals of continuously variable transmissions, it is possible to shift gears to the OD side and/or to the Low side up to the hardware limit of each individual (i.e., the physical possible shifts to full OD and/or full Low).

1 is a block diagram showing the configuration of a shift control device for a continuously variable transmission according to an embodiment together with the configuration of the continuously variable transmission; FIG. It is a figure which shows the gear ratio setting of the continuously variable transmission which concerns on embodiment. It is a figure which shows an example of the shift line (transition of a target gear ratio) before learning, and a shift line after learning. FIG. 5 is a diagram showing an overview of a target gear ratio lower limit value (OD side limit value) map; FIG. 4 is a diagram showing an overview of an integral F/B stop gear ratio (OD side) map; 4 is a flow chart showing a processing procedure of learning processing by the shift control device for a continuously variable transmission according to the embodiment; FIG. 4 is a control block diagram for acquiring/reflecting a learning value;

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Further, in each figure, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

First, with reference to FIG. 1, the configuration of a speed change control device 1 for a continuously variable transmission according to an embodiment will be described. FIG. 1 is a block diagram showing the configuration of a transmission control device 1 for a continuously variable transmission and a continuously variable transmission 30 to which the transmission control device 1 is applied.

The continuously variable transmission 30 is a continuously variable transmission that automatically and steplessly shifts the gear ratio according to the operating state of the vehicle. The continuously variable transmission 30 is connected to the output shaft 15 of the engine 10, converts the driving force from the engine 10, and outputs it.

The continuously variable transmission 30 includes a primary shaft 32 connected to the output shaft 15 of the engine 10 via a torque converter 20 having a clutch function and a torque amplifying function and a reduction gear 31, and arranged parallel to the primary shaft 32. and a secondary shaft 37 .

A primary pulley 34 is provided on the primary shaft 32 . The primary pulley 34 has a fixed sheave 34a joined to the primary shaft 32, and a movable sheave 34b facing the fixed sheave 34a and slidably mounted in the axial direction of the primary shaft 32. It is configured such that the distance between the cone surfaces of the pulleys 34a and 34b, that is, the pulley groove width can be changed. On the other hand, the secondary shaft 37 is provided with a secondary pulley 35 . The secondary pulley 35 has a fixed sheave 35a joined to the secondary shaft 37 and a movable sheave 35b slidably mounted in the axial direction of the secondary shaft 37 so as to face the fixed sheave 35a. It is configured so that the width can be changed.

A chain 36 for transmitting driving force is stretched between the primary pulley 34 and the secondary pulley 35 . By changing the groove widths of the primary pulley 34 and the secondary pulley 35 to change the ratio of the winding diameter of the chain 36 to the pulleys 34 and 35 (pulley ratio), the gear ratio can be changed steplessly. Here, if the winding diameter of the chain 36 around the primary pulley 34 is Rp and the winding diameter of the chain 36 around the secondary pulley 35 is Rs, the gear ratio i is expressed as i=Rs/Rp. Therefore, the gear ratio i is obtained by dividing the primary pulley rotation speed Np by the secondary pulley rotation speed Ns (i=Np/Ns).

A hydraulic chamber 34c is formed in the primary pulley 34 (movable sheave 34b). On the other hand, a hydraulic chamber 35c is formed in the secondary pulley 35 (movable sheave 35b). The groove widths of the primary pulley 34 and the secondary pulley 35 are set and changed by adjusting the primary hydraulic pressure introduced into the hydraulic chamber 34c of the primary pulley 34 and the secondary hydraulic pressure introduced into the hydraulic chamber 35c of the secondary pulley 35. be done.

A valve body (control valve) 50 controls the hydraulic pressure for shifting the continuously variable transmission 30 , that is, the primary hydraulic pressure and the secondary hydraulic pressure described above. The valve body 50 adjusts the hydraulic pressure discharged from the oil pump by opening and closing an oil passage formed in the valve body 50 using a spool valve and a solenoid valve (electromagnetic valve) that moves the spool valve. It is supplied to the hydraulic chamber 34 c of the primary pulley 34 and the hydraulic chamber 35 c of the secondary pulley 35 . The valve body 50 also supplies hydraulic pressure to, for example, a forward/reverse switching mechanism that switches the vehicle between forward and reverse.

Shift control of continuously variable transmission 30 is performed by a transmission control unit (hereinafter referred to as “TCU”) 40 . That is, the TCU 40 adjusts the hydraulic pressure supplied to the hydraulic chamber 34c of the primary pulley 34 and the hydraulic chamber 35c of the secondary pulley 35 by controlling the driving of the solenoid valves that constitute the valve body 50 described above. , to change the gear ratio of the continuously variable transmission 30 .

Here, the TCU 40 is connected to an engine control unit (hereinafter referred to as "ECU") 60 for comprehensively controlling the engine 10, for example, through a CAN (Controller Area Network) 100 so as to be able to communicate with each other.

The ECU 60 is connected to an accelerator pedal sensor 62 that detects the depression amount (operation amount) of the accelerator pedal, that is, the opening degree of the accelerator pedal. The ECU 60 also includes various sensors such as a crank angle sensor 12 that detects the rotational position of the crankshaft, an air flow meter 61 that detects the amount of intake air, a water temperature sensor that detects the temperature of cooling water for the engine 10, and an air-fuel ratio sensor. It is connected.

Here, the ECU 60 determines the cylinder from the output of the cam angle sensor and obtains the engine speed from the output of the crank angle sensor 12 . Further, the ECU 60 acquires various information such as the amount of intake air, the degree of opening of the accelerator, the air-fuel ratio of the air-fuel mixture, and the water temperature of the engine 10 based on the detection signals input from the various sensors described above. Then, the ECU 60 comprehensively controls the engine 10 by controlling various devices such as fuel injection amount, ignition timing, electronically controlled throttle valve, etc. based on the acquired various information. Further, the ECU 60 acquires the engine torque from, for example, the intake air amount and the engine speed. The ECU 60 transmits information such as engine speed, accelerator opening, engine torque (input torque of the continuously variable transmission 30) to the TCU 40 via the CAN 100.

On the other hand, the TCU 40 includes an output shaft rotation sensor 58 attached near the output shaft (secondary shaft 37) of the continuously variable transmission 30 to detect the rotation speed of the output shaft (the rotation speed of the secondary pulley 35), the primary pulley 34, and the output shaft rotation sensor 58. A primary pulley rotation speed sensor 57 for detecting the rotation speed of the torque converter 20, a turbine rotation speed sensor 56 for detecting the turbine rotation speed of the torque converter 20, and the like are connected.

Here, a shift lever (select lever) 51 is provided on the vehicle floor or the like for receiving an operation by the driver to selectively switch between an automatic transmission mode (“D” range) and a manual transmission mode (“M” range). is provided. A range switch 59 is attached to the shift lever 51 so as to move in conjunction with the shift lever 51 to detect the selected position of the shift lever 51 . The range switch 59 is connected to the TCU 40 , and the detected selected position of the shift lever 51 is read into the TCU 40 . In addition to the "D" range and "M" range, the shift lever 51 can be selectively switched between the parking "P" range, the reverse "R" range, and the neutral "N" range.

The shift lever 51 is turned on when the shift lever 51 is positioned on the "M" range side, i.e., when the manual shift mode in which the gear ratio is switched according to the shift operation of the driver is selected, and the shift lever 51 is turned on. An M range switch 52 is incorporated that is turned off when positioned on the "D" range side, that is, when an automatic transmission mode is selected in which the transmission gear ratio is automatically changed according to the operating conditions of the vehicle. M range switch 52 is also connected to TCU 40 .

On the other hand, on the rear side of the steering wheel 53, a plus (+) paddle switch 54 and a minus (-) paddle switch 55 are provided for accepting a shift operation (shift request) by the driver in the manual shift mode ( Hereinafter, the plus paddle switch 54 and the minus paddle switch 55 may be collectively referred to as "paddle switches 54 and 55"). The plus paddle switch 54 is used for manual upshifting, and the minus paddle switch 55 is used for manual downshifting. The positive paddle switch 54 and the negative paddle switch 55 are connected to the TCU 40 , and switch signals of the paddle switches 54 and 55 output from the paddle switches 54 and 55 are read into the TCU 40 .

The TCU 40 includes a microprocessor that performs calculations, an EEPROM that stores programs for causing the microprocessor to execute various processes, a shift map (target gear ratio map), and the like, a RAM that stores various data such as calculation results, and a battery. It is configured with a backup RAM that retains memory contents, an input/output I/F, and the like.

When the automatic shift mode is selected, the TCU 40 automatically and steplessly shifts the gear ratio in accordance with the shift map and according to the operating conditions of the vehicle, such as the throttle opening and the vehicle speed (or engine speed). A shift map corresponding to the automatic shift mode is stored in the EEPROM or the like in the TCU 40. FIG. Here, FIG. 2 shows a shift characteristic diagram showing the relationship between the engine speed and the vehicle speed. In FIG. 2, the horizontal axis is the vehicle speed (km/h) and the vertical axis is the engine speed (rpm). Each of the eight solid lines indicates the relationship between the engine speed and the vehicle speed when the gear ratio is kept constant (that is, the gear ratio characteristics in the manual shift mode). In the automatic shift mode, any gear ratio between 1st (low) and 8th (overdrive) shown in FIG. automatically set according to On the other hand, when the manual shift mode is selected, the TCU 40 controls the gear ratio based on the shift operation accepted by the paddle switches 54,55.

In particular, the TCU 40 shifts to the OD side and/or the Low side up to the hardware limit of each individual (that is, the physical It has a function that enables shifting to full OD and/or full Low that can be taken practically). Therefore, the TCU 40 functionally includes a shift control section 41 , a learning condition determination section 42 , a learning value acquisition section 43 and a storage section 44 . In the TCU 40, programs stored in an EEPROM or the like are executed by the microprocessor, thereby realizing the functions of the shift control section 41, the learning condition determination section 42, the learning value acquisition section 43, and the storage section 44. .

The shift control unit 41 sets a target gear ratio of the continuously variable transmission 30 based on, for example, the accelerator opening and the vehicle speed (or engine speed), and controls the gear ratio. At that time, the shift control unit 41 performs feedback control based on the deviation between the target gear ratio and the actual gear ratio, and controls the actual gear ratio to match the target gear ratio. That is, the shift control section 41 functions as shift control means described in the claims.

In this embodiment, a PI control (Proportional-Integral Controller) is applied to control the gear ratio. That is, the shift control unit 41 changes the gear ratio based on a proportional term (P term) proportional to the deviation between the actual gear ratio and the target gear ratio and an integral term (I term) corresponding to the time integral of the residual deviation. control the control value (for example, target duty or target current value) of the solenoid valve that regulates the hydraulic pressure for In addition to the proportional term (P term) and the integral term (I term), a derivative term (D term) according to the magnitude of the change in the deviation may be used (that is, PID control may be applied). good).

Here, the integral term (I term) accumulates the residual deviation through integration and reflects it in the control value of the solenoid valve. If the F/B control is continued in spite of this, the value of the integral term may be accumulated unnecessarily. Therefore, when the actual gear ratio is between the target gear ratio limit value and the integral F/B stop gear ratio, the shift control unit 41 calculates the time integral of the deviation between the target gear ratio and the actual gear ratio. temporarily suspends the accumulation of the integral term that adjusts the control value.

More specifically, the shift control unit 41 determines whether the actual gear ratio is a target gear ratio lower limit value (full OD) and an integral F/B stop gear ratio (OD side ), stop accumulating the integral term. Similarly, the shift control unit 41 determines whether the actual gear ratio is the target gear ratio upper limit value (full Low) and the integral F/B stop gear ratio (Low side) set for the target gear ratio upper limit value. Stops the action of accumulating the integral term if it is between . In the following, the case of learning the integral F/B stop gear ratio on the full OD side will be mainly described as an example. The integral F/B stop gear ratio on the full Low side can also be learned in the same manner.

The learning condition determination unit 42 determines that the actual gear ratio has reached the integral F/B stop gear ratio (that is, the OD state), and that the vehicle speed, the oil temperature of the continuously variable transmission 30, the input torque, and the secondary If the value of at least one or more parameters of the pulley pressure is within a first predetermined range, and the fluctuation range of the parameter is within a second predetermined range for a certain period of time or more (that is, approximately In the case of a constant speed), for example, when traveling on a flat straight road at a constant speed, it is determined that the learning condition for the integral F/B stop gear ratio is established. That is, the learning condition determination unit 42 functions as learning condition determination means described in the claims. The result of determination as to whether or not the learning condition is satisfied is output to the learning value acquiring section 43 .

When it is determined that the learning condition is established, the learning value acquiring unit 43 changes the target gear ratio further toward the target gear ratio limit value side (full OD side) than the integration F/B stop gear ratio. (that is, to increase the primary pulley pressure) to the shift control unit 41 . After that, the learned value acquiring unit 43 acquires and stores the actual gear ratio, the target secondary pulley pressure, and the input torque when the actual gear ratio no longer changes toward the target gear ratio limit value side (full OD side). . That is, the learning value acquisition unit 43 gradually decreases the target gear ratio when the above-described predetermined learning condition is established, and when the actual gear ratio reaches the minimum value (physical limit value), the actual gear ratio is reduced. Acquire gear ratio, target secondary pulley pressure, and input torque. Then, the learned value acquiring unit 43 changes (corrects) the integral F/B stop gear ratio based on the acquired actual gear ratio, target secondary pulley pressure, and input torque, and calculates the post-learning integral F/B stop gear ratio. Get the ratio. In other words, the learned value acquisition unit 43 functions as a learned value acquisition unit recited in the claims.

More specifically, the integral F/B stop gear ratio is set according to the target secondary pulley pressure of the continuously variable transmission 30 and the input torque, and the learning value acquisition unit 43 determines the acquired target secondary pulley pressure and Learning the integral F/B stop gear ratio and the learned value is added as an offset value to the map search value of the integrated F/B stop gear ratio during normal control to obtain the integrated F/B stop gear ratio after learning.

More specifically, as shown in FIG. 7 , first, the learning value acquiring unit 43 uses the acquired input torque and target secondary pulley pressure to search the integral F/B stop gear ratio map, thereby obtaining the integral Find the F/B stop gear ratio. Next, the learned value obtaining unit 43 subtracts the obtained gear ratio from the obtained integral F/B stop gear ratio to obtain the learned value (correction value) of the integral F/B stop gear ratio. On the other hand, the learning value acquiring unit 43 retrieves the integral F/B stop gear ratio (learned previous/default). Then, the learned value acquisition unit 43 adds the learned value (correction value) of the integral F/B stop gear ratio to the integral F/B stop gear ratio (before learning), and calculates the integral F/B stop gear ratio after correction. Get gear ratio. It should be noted that the integrated F/B inhibition gear ratio after learning is output to the shift control section 41 .

Here, an integral F/B stop gear ratio (OD side) map that defines the relationship between the target secondary pulley pressure of the continuously variable transmission 30, the input torque, and the integral F/B stop gear ratio (OD side) are stored in a storage unit 44 such as an EEPROM. The storage unit 44 also stores a target gear ratio lower limit value (OD side) map that defines the relationship between the target secondary pulley pressure of the continuously variable transmission 30, the input torque, and the target gear ratio lower limit value (OD side). ing. That is, the storage unit 44 functions as storage means described in the claims.

Here, FIG. 4 shows an overview of the target gear ratio lower limit value (OD side) map. FIG. 5 shows an overview of the integrated F/B stop gear ratio (OD side) map. In FIG. 4, the horizontal axis is the input torque (Nm), and the vertical axis is the target secondary pulley pressure (MPa). In the target gear ratio lower limit value (OD side) map, the target gear ratio lower limit value is given for each combination (lattice point) of the input torque and the target secondary pulley pressure. Similarly, in FIG. 5, the horizontal axis is the input torque (Nm) and the vertical axis is the target secondary pulley pressure (MPa). In the integral F/B stop gear ratio (OD side) map, an integral F/B stop gear ratio is given for each combination (lattice point) of input torque and target secondary pulley pressure. Note that the target gear ratio lower limit value (OD side) map is set so that the value of each grid point is smaller than the integral F/B stop gear ratio (OD side) map.

After the learning is performed as described above, the shift control unit 41 uses the learned integral F/B stop gear ratio to control the execution or stop of the accumulation operation of the integral term. That is, when the actual gear ratio is between the target gear ratio limit value (lower limit value) and the post-learning integrated F/B stop gear ratio (OD side), the gear shift control unit 41 determines whether the gear ratio is equal to the target gear ratio. The operation of accumulating the integral term for adjusting the control value according to the time integral of the deviation from the actual gear ratio is stopped.

Here, FIG. 3 shows an example of a shift line before learning (transition of the target gear ratio) and an example of a shift line after learning. The horizontal axis of FIG. 3 is the vehicle speed (km/h), and the vertical axis is the engine speed (rpm). In FIG. 3, the target gear ratio limit value (lower limit) is indicated by a thin solid line, the integral F/B stop gear ratio before learning is indicated by a thin dashed line, and the integral F/B stop gear ratio after learning is indicated by a thin single point. The shift line before learning is shown by a dashed line, the shift line before learning is shown by a thick dashed line, and the shift line after learning is shown by a thick solid line.

As shown in FIG. 3, the area on the target gear ratio limit side (full OD side) of the integral F/B stop gear ratio is the area where the integral F/B correction is stopped. In the unlearned state, as indicated by the thin dashed line, the integral F/B stop gear ratio is set at the upper limit of the variation in accordance with the worst case. Therefore, as indicated by the thick dashed line, full OD cannot be used. On the other hand, as the learning progresses, the integrated F/B stop gear ratio (OD side) decreases and approaches the hardware limit, expanding the usable range, as indicated by the dashed line. This allows up to full OD to be used, as indicated by the thick solid line.

Next, the operation of the speed change control device 1 for the continuously variable transmission will be described with reference to FIG. FIG. 6 is a flow chart showing a processing procedure of learning processing by the speed change control device 1 for a continuously variable transmission. This process is repeatedly executed in the TCU 40 every predetermined time (for example, every 10 ms). Here, the case of learning the integral F/B inhibition gear ratio on the OD side will be described as an example. The integral F/B stop gear ratio on the full Low side can also be learned in the same manner.

First, in step S100, it is determined whether or not the actual gear ratio has reached the integration F/B stop gear ratio (whether or not the actual gear ratio has reached OD). Here, if the actual gear ratio has not reached the integration F/B stop gear ratio, this processing is temporarily exited. On the other hand, when the actual gear ratio has reached the integration F/B stop gear ratio, the process proceeds to step S102.

Next, in step S102, it is determined whether or not the learning condition for the integral F/B stop gear ratio is satisfied. For example, in step S102, the value of at least one of the vehicle speed, the oil temperature of the continuously variable transmission 30, the input torque, and the secondary pulley pressure is within a first predetermined range, and , a determination is made as to whether or not the fluctuation range of the parameter is within a second predetermined range for a predetermined period of time or more. Here, if the learning condition is not satisfied, the process exits from this process. On the other hand, when all the learning conditions are met (when the vehicle is running stably at OD), the process proceeds to step S104.

When the learning condition is satisfied, in step S104, the primary pulley pressure of the continuously variable transmission 30 is increased (the UP-Duty is increased), and the gear ratio is controlled to be gradually changed to the OD side. is executed. That is, control is performed so as to change the actual gear ratio to the target gear ratio limit value (lower limit) side from the integral F/B stop gear ratio.

After that, in step S106, it is determined whether or not the gear ratio has decreased, that is, whether or not the actual gear ratio has moved toward the OD side. Here, if the gear ratio does not decrease even if the primary pulley pressure is increased, this processing is temporarily exited after the increase in the primary pressure is stopped. That is, the learning process ends. On the other hand, when the gear ratio decreases due to the increase in the primary pulley pressure, the process proceeds to step S108.

In step S108, the actual gear ratio, target secondary pulley pressure, and input torque are saved. Then, in step S110, using the stored target secondary pulley pressure and input torque, the integrated F/B stop gear ratio obtained by searching the integrated F/B stop gear ratio map, and the stored The difference from the actual gear ratio is used as the learned value of the integral F/B stop gear ratio, and the learned value is added as an offset value to the map search value of the integral F/B stop gear ratio during normal control. is obtained. Details of how to obtain the learned value and how to obtain the integral F/B stop gear ratio after learning are as described above, and detailed description thereof will be omitted here.

As described in detail above, according to the present embodiment, when it is determined that the learning condition is satisfied, the target gear ratio is set to the target gear ratio limit value even higher than the integral F/B stop gear ratio. When a request is made to change to the side of the target gear ratio limit value, the actual gear ratio is acquired, and based on the actual gear ratio, the integral F/B stop gear shift is performed. The ratio is changed to obtain the integral F/B stop gear ratio after learning. Then, execution or stop of the operation of accumulating the integral term is controlled using the learned integral F/B stop gear ratio. That is, by learning the integral F/B prohibition gear ratio in accordance with the individual (continuously variable transmission 30), the integral F Since the /B stop gear ratio can be set (corrected), accumulation of unnecessary integral terms can be prevented, and the physical limit gear ratio of each individual can be used up. As a result, irrespective of individual hardware variations of the continuously variable transmission 30, each individual can shift to the OD side and/or the Low side up to the hardware limit (that is, each individual physically possible full OD and/or shift to full Low). In particular, since full OD can be used up to the physical limit of each individual, the rotation speed of the engine 10 can be lowered, and fuel consumption can be improved and noise can be reduced.

According to this embodiment, the integral F/B stop gear ratio is set for each of the target gear ratio lower limit (full OD) and/or the target gear ratio upper limit (full Low). Integral F/B stop gear ratios can be learned and set for OD and/or Full Low respectively. Therefore, it is possible to shift to full OD and/or full Low.

According to this embodiment, the integral F/B stop gear ratio is set according to the target secondary pulley pressure of the continuously variable transmission 30 and the input torque, and the actual gear ratio changes toward the target gear ratio limit value. The actual gear ratio, the target secondary pulley pressure, and the input torque are acquired, and the integral F/B stop gear ratio is changed based on the actual gear ratio, the target secondary pulley pressure, and the input torque, and after learning An integral F/B stop gear ratio is obtained. Therefore, it is possible to obtain and learn the integral F/B stop gear ratio appropriately according to parameters such as the actual gear ratio, the target secondary pulley pressure, and the input torque.

According to the present embodiment, the integral F/B stop gear ratio map that defines the relationship between the target secondary pulley pressure of the continuously variable transmission 30, the input torque, and the integral F/B stop gear ratio is stored. The difference between the integral F/B stop gear ratio obtained by searching the integral F/B stop gear ratio map using the acquired target secondary pulley pressure and input torque and the acquired actual gear ratio is , the learned value of the integral F/B stop gear ratio, the learned value is added as an offset value to the map search value of the integral F/B stop gear ratio during normal control, and the integral F/B stop gear ratio after learning is calculated. A ratio is required. Therefore, the map can be used to obtain the integral F/B stop gear ratio, and the learned value can be reflected in the integral F/B stop gear ratio.

According to this embodiment, in addition to the fact that the actual gear ratio has reached the integral F/B stop gear ratio, at least one of the vehicle speed, the oil temperature of the continuously variable transmission 30, the input torque, and the secondary pulley pressure The learning condition is established when the value of any one or more parameters is within a first predetermined range and the fluctuation width of the parameter is within a second predetermined range for a certain period of time or more. is determined. Therefore, it is possible to more accurately determine whether or not the learning condition is satisfied (that is, whether or not the learning process can be executed).

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible. For example, in the above embodiments, the present invention is applied to a chain-type continuously variable transmission (CVT), but instead of the chain-type continuously variable transmission, it is also applicable to, for example, a metal belt-type continuously variable transmission. can do.

Further, in the above embodiment, the full OD side integral F/B stop gear ratio is mainly learned, but the full Low side integral F/B stop gear ratio can be learned in the same manner. can be done. Furthermore, the learning condition for the integral F/B stop gear ratio described above is an example, and the learning condition is not limited to the above embodiment, and can be arbitrarily set according to requirements and the like.

In the above embodiment, for example, the engine torque (CVT input torque) is calculated on the ECU 60 side and received via the CAN 100, but it may be calculated on the TCU 40 side. Further, in the above embodiment, the TCU 40 that controls the continuously variable transmission 30 and the ECU 60 that controls the engine 10 are configured as separate pieces of hardware, but they may be configured as one piece of hardware.

1 Transmission Control Device for Continuously Variable Transmission 10 Engine 12 Crank Angle Sensor 20 Torque Converter 30 Continuously Variable Transmission 34 Primary Pulley 35 Secondary Pulley 36 Chain 40 TCU
41 shift control unit 42 learning condition determination unit 43 learning value acquisition unit 44 storage unit 56 turbine rotation speed sensor 57 primary pulley rotation speed sensor 58 output shaft rotation speed sensor 59 range switch 60 ECU
61 air flow meter 62 accelerator pedal sensor 100 CAN

Claims (5)

Feedback control is performed based on the deviation between the target gear ratio and the actual gear ratio to control the actual gear ratio to coincide with the target gear ratio, and the actual gear ratio is equal to the target gear ratio limit value and the integral F /B stop gear ratio, shift control means for stopping the operation of accumulating an integral term for adjusting the control value according to the time integral of the deviation between the target gear ratio and the actual gear ratio;
learning condition determination means for determining that a learning condition is established when the actual gear ratio has reached the integral F/B stop gear ratio;
When it is determined that the learning condition is established, the target gear ratio is requested to be changed further to the target gear ratio limit value side than the integral F/B stop gear ratio, and the actual gear ratio is no longer changed toward the target gear ratio limit value side, the integral F/B stop gear ratio is changed based on the actual gear ratio, and the learned integral F/ learning value acquiring means for acquiring the B stop gear ratio;
The integral F/B stop gear ratio is set according to the target secondary pulley pressure of the continuously variable transmission and the input torque,
The learning value acquiring means acquires the actual gear ratio, the target secondary pulley pressure, and the input torque when the actual gear ratio does not change toward the target gear ratio limit value side, and obtains the actual gear ratio, the target secondary pulley pressure, and , changing the integral F/B stop gear ratio based on the input torque to obtain the learned integral F/B stop gear ratio;
The speed change control device for a continuously variable transmission, wherein the speed change control means uses the learned integral F/B stop speed ratio to control the execution or stop of the operation of accumulating the integral term. The target gear ratio limit value is a lower limit value of the target gear ratio and/or an upper limit value of the target gear ratio,
The continuously variable transmission according to claim 1, wherein the integral F/B stop gear ratio is set for each of the target gear ratio lower limit value and/or the target gear ratio upper limit value. gear control device. further comprising storage means for storing an integral F/B stop gear ratio map that defines the relationship between the target secondary pulley pressure of the continuously variable transmission, the input torque, and the integral F/B stop gear ratio;
The learning value acquiring means uses the acquired target secondary pulley pressure and the input torque to obtain an integrated F/B stop gear ratio obtained by searching the integrated F/B stop gear ratio map, and an acquired The difference from the actual gear ratio is used as a learned value for the integral F/B stop gear ratio, and the learned value is added as an offset value to the map search value of the integral F/B stop gear ratio during normal control, and learned. 3. A speed change control device for a continuously variable transmission according to claim 1, wherein a post-integral F/B stop gear ratio is obtained. Feedback control is performed based on the deviation between the target gear ratio and the actual gear ratio to control the actual gear ratio to coincide with the target gear ratio, and the actual gear ratio is equal to the target gear ratio limit value and the integral F /B stop gear ratio, shift control means for stopping the operation of accumulating an integral term for adjusting the control value according to the time integral of the deviation between the target gear ratio and the actual gear ratio;
learning condition determination means for determining that a learning condition is established when the actual gear ratio has reached the integral F/B stop gear ratio;
When it is determined that the learning condition is established, the target gear ratio is requested to be changed further to the target gear ratio limit value side than the integral F/B stop gear ratio, and the actual gear ratio is no longer changed toward the target gear ratio limit value side, the integral F/B stop gear ratio is changed based on the actual gear ratio, and the learned integral F/ learning value acquiring means for acquiring the B stop gear ratio;
In addition to the fact that the actual gear ratio has reached the integral F/B stop gear ratio, the learning condition determination means determines whether the vehicle speed, the oil temperature of the continuously variable transmission, the input torque, or the secondary pulley pressure , when the value of at least one or more parameters is within a first predetermined range and the fluctuation range of the parameter is within a second predetermined range, the learning condition is established. judge,
The speed change control device for a continuously variable transmission, wherein the speed change control means uses the learned integral F/B stop speed ratio to control the execution or stop of the operation of accumulating the integral term. In addition to the fact that the actual gear ratio has reached the integral F/B stop gear ratio, the learning condition determination means determines whether the vehicle speed, the oil temperature of the continuously variable transmission, the input torque, or the secondary pulley pressure , when the value of at least one or more parameters is within a first predetermined range and the fluctuation range of the parameter is within a second predetermined range, the learning condition is established. 4. A shift control device for a continuously variable transmission according to any one of claims 1 to 3 , characterized in that it determines.

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