JP2019120266A - Control device of transmission - Google Patents

Abstract

To provide a control device of a transmission capable of improving followability in shift change control.SOLUTION: A control pressure according to a deviation E between a target change gear ratio and an actual change gear ratio of CVT, is determined. A hydraulic pressure of the control pressure is supplied to a movable sheave of a primary pulley and a movable sheave of a secondary pulley, so that the actual change gear ratio can approach the target of the change gear ratio. A dischargeable pressure of an oil pump for making a hydraulic circuit generate an original pressure, is estimated, and an upper limit of the control pressure is limited to the dischargeable pressure. Thus a guard control pressure as a control pressure after limitation by the dischargeable pressure is limited to a smaller value in accordance with decrease of the dischargeable pressure. A wind-up amount obtained by subtracting the guard control pressure from the control pressure is increased, and an I control value calculated by integration operation of the deviation between a multiplication value obtained by multiplying the deviation by an I gain Ki and an amplification value of the wind-up amount output by an amplification portion 129, is decreased, in accordance with increase of the difference between the control pressure and the guard control pressure.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control device for a transmission.

  As a transmission mounted on a vehicle, CVT (Continuously Variable Transmission) is widely known.

  The CVT has a configuration in which an endless belt is wound around a primary pulley on the input side and a secondary pulley on the output side. When torque from a drive source such as an engine is input to the primary pulley, the frictional force between the primary pulley and the belt transmits torque from the primary pulley to the belt, and the frictional force between the secondary pulley and the belt Torque is transmitted from the belt to the secondary pulley.

  Both the primary pulley and the secondary pulley are fixed sheaves, movable sheaves disposed opposite to the fixed sheave with the belt interposed therebetween, and on the opposite side of the movable sheaves with respect to the movable sheaves. And a piston that forms a piston chamber (oil chamber) with the movable sheave. By controlling the hydraulic pressure acting on the movable sheaves of the primary pulley and the secondary pulley, the distance between the fixed sheave and the movable sheave is changed. Along with this, the winding diameter of the belt with respect to the primary pulley changes, the distance between the fixed sheave and the movable sheave of the secondary pulley changes, and the winding diameter of the belt with respect to the secondary pulley changes. As a result, the transmission ratio (pulley ratio) changes steplessly and continuously.

JP, 2004-176890, A

  In CVT shift control, a gear ratio target is set, and a control pressure corresponding to the deviation between the gear ratio target and the actual gear ratio that is the actual gear ratio, that is, acting on the movable sheaves of the primary and secondary pulleys. The hydraulic pressure command value is set. Then, the operation of the valve included in the hydraulic circuit is controlled so that the control pressure acts on each movable sheave of the primary pulley and the secondary pulley.

  However, there is room for various improvements in the conventional shift control, and improvement in followability is desired.

  An object of the present invention is to provide a control device for a transmission that can improve the follow-up performance of shift control.

  In order to achieve the above object, a control device of a transmission according to the present invention is endless on a pulley provided with a movable sheave whose distance from the fixed sheave is changed by the hydraulic pressure supplied from the hydraulic circuit to the oil chamber. Control device for a transmission having a configuration in which the belt is wound, the hydraulic pressure for controlling the position of the movable sheave, according to the deviation between the transmission gear ratio target and the actual transmission gear ratio Control pressure setting means for setting the control pressure, and dischargeable pressure estimation means for estimating the dischargeable pressure of the oil pump that generates the original pressure in the hydraulic circuit in consideration of the volume change of the oil chamber due to the movement of the movable sheave And control pressure limiting means for limiting the control pressure set by the control pressure setting means based on the dischargeable pressure estimated by the dischargeable pressure estimation means.

  According to this configuration, the control pressure is set in accordance with the deviation between the target of the transmission gear ratio of the transmission and the actual gear ratio. By supplying the hydraulic pressure of this control pressure to the movable sheave, the actual gear ratio can be brought close to the target of the gear ratio.

  There is an upper limit to the control pressure because there is a limit to the ability of the oil pump to generate the source pressure of the hydraulic circuit. When the control pressure is set to exceed the upper limit, the deviation between the target of the gear ratio and the actual gear ratio is not reduced, and when the setting of the control pressure includes integral calculation (integral control), the deviation is accumulated. Increase.

  Therefore, the dischargeable pressure of the oil pump that causes the hydraulic circuit to generate the original pressure is estimated, and the control pressure is limited based on the dischargeable pressure. Thus, even if the setting of the control pressure includes an integral operation for securing the followability of the control, it is possible to suppress the accumulation of the deviation between the target of the gear ratio and the actual gear ratio. Therefore, the followability of the shift control can be improved.

  According to the present invention, it is possible to improve the followability of the shift control.

It is a skeleton diagram showing composition of a drive system of vehicles. It is a block diagram showing composition of a control system concerning one embodiment of the present invention. It is a block diagram showing composition of a sheave shift controller. It is a block diagram which shows the structure of the upper limit guard amount setting part. It is a flowchart which shows the flow of the process performed by a sheave shift controller. It is a figure which shows an example of the time change of I control value, control pressure, and real gear ratio.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

<Drive system of vehicle>
FIG. 1 is a skeleton diagram showing a configuration of a drive system of a vehicle 1.

  The vehicle 1 is an automobile having an engine 2 as a drive source.

  The engine 2 is provided with an electronic throttle valve for adjusting the amount of intake air to the combustion chamber of the engine 2, an injector (fuel injection device) for injecting fuel to intake air, and an ignition plug for generating an electric discharge in the combustion chamber. It is done. The engine 2 is additionally provided with a starter for starting it. The power of the engine 2 is transmitted to the differential gear 5 via the torque converter 3 and a belt type CVT (Continuously Variable Transmission) 4, and from the differential gear 5 via the left and right drive shafts 6L and 6R. It is transmitted to the left and right drive wheels 7L and 7R, respectively.

  The torque converter 3 is a torque converter with a lockup mechanism, and includes a front cover 11, a pump impeller 12, a turbine runner 13 and a lockup clutch (lockup piston) 14. The crankshaft of the engine 2 is connected to the front cover 11, and the front cover 11 rotates integrally with the crankshaft. The pump impeller 12 is disposed on the opposite side of the front cover 11 to the engine side. The pump impeller 12 is provided integrally rotatably with the front cover 11. The turbine runner 13 is disposed between the front cover 11 and the pump impeller 12 and rotatably provided about a common rotation axis with the front cover 11. The lockup clutch 14 is disposed between the front cover 11 and the turbine runner 13.

  The lockup clutch 14 is a differential pressure between the oil pressure of the release side oil chamber 15 between the lockup clutch 14 and the front cover 11 and the oil pressure of the engagement side oil chamber 16 between the lockup clutch 14 and the pump impeller 12. Are engaged / released. That is, in the state where the oil pressure of the release side oil chamber 15 is higher than the oil pressure of the engagement side oil chamber 16, the lockup clutch 14 is separated from the front cover 11 by the differential pressure, and the lockup clutch 14 is released. It is in the up-off state (released state). In a state where the oil pressure of the engagement side oil chamber 16 is higher than the oil pressure of the release side oil chamber 15, the lockup clutch 14 is pressed against the front cover 11 by the differential pressure, and the lockup clutch 14 is engaged. It will be in the on state (fastening state).

  In the lockup off state, when the E / G output shaft is rotated, the pump impeller 12 is rotated. As the pump impeller 12 rotates, a flow of oil from the pump impeller 12 toward the turbine runner 13 occurs. The flow of oil is received by the turbine runner 13 and the turbine runner 13 rotates. At this time, an amplification action of the torque converter 3 occurs, and a power larger than the power (torque) of the E / G output shaft is generated in the turbine runner 13.

  In the lockup on state, when the E / G output shaft is rotated, the E / G output shaft, the pump impeller 12 and the turbine runner 13 rotate together.

  An oil pump 8 is provided between the torque converter 3 and the CVT 4. The oil pump 8 is a mechanical oil pump, and a pump shaft is provided so as to rotate integrally with the pump impeller 12 of the torque converter 3. Thus, when the pump impeller 12 is rotated by the power of the engine 2, the pump shaft of the oil pump 8 is rotated, and the oil pump 8 generates an oil pressure.

  The CVT 4 transmits the power input from the torque converter 3 to the differential gear 5. The CVT 4 includes an input shaft (input shaft) 21, an output shaft (output shaft) 22, a belt transmission mechanism 23, and a forward / reverse switching mechanism 24.

  The input shaft 21 is connected to the turbine runner 13 of the torque converter 3 and provided integrally rotatably around the same rotation axis as the turbine runner 13.

  The output shaft 22 is disposed in parallel with the input shaft 21. An output gear 25 is supported by the output shaft 22 so as not to be relatively rotatable.

  The belt transmission mechanism 23 includes a primary shaft 31 and a secondary shaft 32. The primary shaft 31 and the secondary shaft 32 are disposed on the same axis as the input shaft 21 and the output shaft 22, respectively.

  The belt transmission mechanism 23 has a configuration in which an endless belt 35 is wound around a primary pulley 33 supported by the primary shaft 31 and a secondary pulley 34 supported by the secondary shaft 32.

  Primary pulley 33 is disposed opposite to fixed sheave 41 fixed to primary shaft 31 and fixed sheave 41 with belt 35 interposed therebetween, and movable sheave supported on primary shaft 31 so as to be movable in the axial direction and to be relatively non-rotatable. And 42 are provided. A piston 43 fixed to the primary shaft 31 is provided on the opposite side of the movable sheave 42 with respect to the fixed sheave 41, and a piston chamber (oil chamber) 44 is formed between the movable sheave 42 and the piston 43 There is.

  Secondary pulley 34 is disposed opposite to fixed sheave 45 fixed to secondary shaft 32 and fixed sheave 45 with belt 35 interposed therebetween, and is supported movably in the axial direction of secondary shaft 32 and is not relatively rotatable. A movable sheave 46 is provided. A piston 47 fixed to the secondary shaft 32 is provided on the opposite side of the movable sheave 46 with respect to the fixed sheave 45, and a piston chamber 48 is formed between the movable sheave 46 and the piston 47.

  Due to the movement of the movable sheave 42 of the primary pulley 33, the groove width which is the distance between the fixed sheave 41 and the movable sheave 42 changes continuously. The movement of the movable sheave 46 of the secondary pulley 34 continuously changes the groove width which is the distance between the fixed sheave 45 and the movable sheave 46. By continuously changing the groove widths of the primary pulley 33 and the secondary pulley 34, it is possible to change the winding diameter of the belt 35 to the primary pulley 33 and the secondary pulley 34, and the transmission ratio (pulley ratio) is continuously variable. Can be changed continuously.

  Although not shown, a bias spring for interposing an initial clamping pressure (initial thrust) on the belt 35 is interposed between the movable sheave 46 and the piston 47. The elastic force of the bias spring biases the movable sheave 46 and the piston 47 away from each other.

  The forward / reverse switching mechanism 24 is interposed between the input shaft 21 and the primary shaft 31 of the belt transmission mechanism 23. The forward / reverse switching mechanism 24 includes a planetary gear mechanism 51, a clutch C1 and a brake B1.

  The planetary gear mechanism 51 includes a carrier 52, a sun gear 53 and a ring gear 54.

  The carrier 52 is fitted on the input shaft 21 so as to be relatively rotatable. The carrier 52 rotatably supports the plurality of pinion gears 55. The plurality of pinion gears 55 are disposed circumferentially.

  The sun gear 53 is supported by the input shaft 21 so as not to be relatively rotatable, and is disposed in a space surrounded by the plurality of pinion gears 55. The gear teeth of the sun gear 53 mesh with the gear teeth of each pinion gear 55.

  The ring gear 54 is provided such that its rotational axis coincides with the axis of the primary shaft 31. The primary shaft 31 of the belt transmission mechanism 23 is connected to the ring gear 54. The gear teeth of the ring gear 54 are formed to collectively surround the plurality of pinion gears 55, and mesh with the gear teeth of each pinion gear 55.

  The clutch C1 is switched by hydraulic pressure to an engaged state (on) in which the carrier 52 and the sun gear 53 are directly coupled (integrally rotatably coupled) and a released state (off) in which the direct coupling is released.

  The brake B1 is provided between the carrier 52 and the transmission case accommodating the torque converter 3 and the CVT 4 and is engaged (on) for braking the carrier 52 by hydraulic pressure and in the released state (allowing rotation of the carrier 52). Can be switched off and on.

  A shift lever (select lever) is disposed in the interior of the vehicle 1 at a position where the driver can operate. In the movable range of the shift lever, for example, a P (parking) position, an R (reverse) position, an N (neutral) position and a D (drive) position are provided in line in this order.

  When the shift lever is in the P position, both the clutch C1 and the brake B1 are released, and the parking lock gear (not shown) is fixed, whereby the P range, which is one of the CVT 4 shift ranges, is configured. Be done. When the shift lever is in the N position, both the clutch C1 and the brake B1 are released, and the parking lock gear is not fixed. Thus, an N range, which is one of the CVT 4 shift ranges, is formed. When both the clutch C1 and the brake B1 are released, the input shaft 21 and the sun gear 53 idle, and the power of the engine 2 is not transmitted to the drive wheels 7L and 7R.

  When the shift lever is at the D position, the brake B1 is engaged and the clutch C1 is released, whereby the forward range, which is one of the shift ranges of the CVT 4, is configured. In the forward range, when the power of the engine 2 is input to the input shaft 21, the sun gear 53 rotates integrally with the input shaft 21 with the carrier 52 stationary. Therefore, the rotation of the sun gear 53 is reversely and deceleratedly transmitted to the ring gear 54. As a result, the ring gear 54 rotates, and the primary shaft 31 and the primary pulley 33 of the belt transmission mechanism 23 rotate integrally with the ring gear 54. The rotation of the primary pulley 33 is transmitted to the secondary pulley 34 via the belt 35 to rotate the secondary pulley 34 and the secondary shaft 32. Then, the output shaft 22 and the output gear 25 rotate integrally with the secondary shaft 32. The output gear 25 meshes with the differential gear 5 (the input gear of the differential gear 5). When the output gear 25 rotates, the drive shafts 6L and 6R extending leftward and rightward from the differential gear 5 rotate and the drive wheels 7L and 7R rotate, whereby the vehicle 1 advances.

  When the shift lever is at the R position, the brake B1 is released, and the clutch C1 is engaged, whereby an R range, which is one of the transmission ranges of the CVT 4, is configured. In the R range, when the power of the engine 2 is input to the input shaft 21, the carrier 52 and the sun gear 53 rotate integrally with the input shaft 21. Therefore, the rotation of the sun gear 53 is transmitted to the ring gear 54 without being reversed in the rotational direction. As a result, the ring gear 54 rotates, and the primary shaft 31 and the primary pulley 33 of the belt transmission mechanism 23 rotate integrally with the ring gear 54. The rotation of the primary pulley 33 is transmitted to the secondary pulley 34 via the belt 35 to rotate the secondary pulley 34 and the secondary shaft 32. Then, the output shaft 22 and the output gear 25 rotate integrally with the secondary shaft 32. When the output gear 25 rotates, the drive shafts 6L and 6R extending leftward and rightward from the differential gear 5 rotate and the drive wheels 7L and 7R rotate, whereby the vehicle 1 travels backward.

<Control system of vehicle>
FIG. 2 is a block diagram showing a configuration of a control system of the vehicle 1.

  The vehicle 1 is provided with an ECU (Electronic Control Unit) having a configuration including a microcomputer (micro controller unit). The microcomputer incorporates, for example, a CPU, a non-volatile memory such as a flash memory, and a volatile memory such as a dynamic random access memory (DRAM). Although only one ECU 101 for controlling the torque converter 3 and the CVT 4 is shown in FIG. 2, the vehicle 1 is equipped with a plurality of ECUs having the same configuration as the ECU 101 in order to control each part. ing. The plurality of ECUs including the ECU 101 are connected so as to enable two-way communication by a CAN (Controller Area Network) communication protocol. Further, a sensor necessary for control, for example, a pressure sensor 102 for detecting the hydraulic pressure (actual pressure) supplied to the movable sheave 42 of the primary pulley 33 and the movable sheave 47 of the secondary pulley 34 is connected to the ECU 101 .

  The ECU 101 functions as a sheave shift controller for shift control that controls the transmission ratio of the CVT 4. In other words, the ECU 101 has a function as a sheave shift controller that controls the transmission ratio of the CVT 4.

  In the shift control by this function, first, a target rotation number corresponding to the accelerator opening degree and the vehicle speed is set based on the shift diagram. The shift map is a map that defines the relationship between the accelerator opening degree and the vehicle speed and the target rotational speed, and is stored in, for example, a non-volatile memory of the ECU 101. Information on the accelerator opening degree and the vehicle speed is transmitted from the engine ECU that controls the engine 2 to the ECU 101, for example. When the target rotational speed is set, a target of the gear ratio is set to make the rotational speed input to the input shaft 21 coincide with the target rotational speed.

  Next, a deviation E between the target gear ratio and the actual gear ratio, which is the actual gear ratio, is determined, and control pressures for the primary pulley 33 and the secondary pulley 34 according to the deviation E are set. The valves included in the hydraulic circuit 111 for supplying hydraulic pressure to the torque converter 3 and each part of the CVT 4 so that those control pressures act on the movable sheave 42 of the primary pulley 33 and the movable sheave 46 of the secondary pulley 34 It is controlled.

  The actual gear ratio can be obtained, for example, by dividing the number of rotations of primary pulley 33 by the number of rotations of secondary pulley 34. The rotational speed of the primary pulley 33 is calculated from a detection signal of a primary rotation sensor that outputs a pulse signal synchronized with the rotation of the primary shaft 31 as a detection signal. Further, the number of rotations of the secondary pulley 34 is calculated from a detection signal of a secondary rotation sensor that outputs a pulse signal synchronized with the rotation of the secondary shaft 32 as a detection signal.

<Sieve shift controller>
FIG. 3 is a block diagram showing the configuration of the sheave shift controller.

  The sheave shift controller calculates deviation (control deviation) E between the gear ratio target and the actual gear ratio, and P control according to deviation E by P operation (proportional operation) with P (Proportional) gain Kp. A P control unit 122 that outputs a value, an I control unit 123 that outputs an I control value according to the deviation E by an I operation (integral operation) with an I (Integral) gain Ki, and a D (differential) gain Kd. A D control unit 124 that outputs a D control value according to the deviation E by a D operation (differentiation operation), and a control pressure output unit 125 that outputs the sum of the P control value, the I control value, and the D control value as a control pressure The upper limit limiting unit 126 that limits the upper limit of the control pressure output by the control pressure output unit 125 and outputs the guard control pressure whose upper limit is limited, and the control pressure upper limit guard used for limitation by the upper limit limiting unit 126 On setting the amount It has substantially a guard amount setting unit 127.

  Furthermore, the sheave shift controller subtracts the guard control pressure output from the upper limit limiting unit 126 from the control pressure output from the control pressure output unit 125, and outputs the subtraction value as a windup amount, and The apparatus substantially comprises an amplification unit 129 that amplifies the windup amount output by the windup amount calculation unit 128 with a predetermined windup gain. Then, the I control value is calculated by integrating the deviation between the multiplication value obtained by multiplying the deviation E by the I gain Ki and the amplification value of the windup amount output by the amplification part 129 in the I control part 123.

<Upper limit guard setting unit>
FIG. 4 is a block diagram showing the configuration of the upper limit guard amount setting unit 127. As shown in FIG.

  The upper limit guard amount setting unit 127 estimates a source pressure of the hydraulic circuit 111 from the actual pressure detected by the pressure sensor 102 and outputs an estimated value (source pressure estimated value) and an actual gear ratio Limit value calculation unit 132 that calculates a limit value according to the volume change amount of each piston chamber (oil chamber) 44, 48 of primary pulley 33 and secondary pulley 34 from the change amount of By subtracting the limit value calculated by the limit value calculation unit 132 from the pump shaft rotational speed of the oil pump 8 and outputting the subtraction value to the primary pulley 33 and the secondary pulley 34 (movable sheaves 42, 46) A pump dischargeable pressure estimation unit 134 that estimates the dischargeable pressure of the oil pump 8 from the oil temperature of the supplied hydraulic oil and the subtraction value output from the subtraction unit 133; A minimum value selection unit 135 which selects and outputs the minimum value of the source pressure estimated value output by the pressure estimation unit 131 and the dischargeable pressure estimated by the pump dischargeable pressure estimation unit 134; According to the determination result of the windup determination unit 136 which determines whether the windup amount is greater than 0 by comparing the windup amount output by 3) with 0, and the determination result of the windup determination unit 136 Accordingly, one of the dischargeable pressure output by the pump dischargeable pressure estimation unit 134 and the minimum value output by the minimum value selection unit 135 is selected, and the selection output unit 137 configured to output as the upper limit guard amount substantially Have.

  If the hydraulic pressure (actual pressure) supplied to the movable sheaves 42 and 46 does not follow the control pressure due to a decrease in the original pressure due to a disturbance or the like, the actual pressure detected by the pressure sensor 102 decreases. Therefore, the source pressure estimation unit 131 can estimate the source pressure from the hydraulic pressure detected by the pressure sensor 102.

  The limit value calculation unit 132 calculates a fluid inflow amount dQpri / dt, which is the inflow amount of hydraulic oil into the piston chamber 44 of the primary pulley 33, according to the following equation (1).

ただし、Apri：プライマリプーリ３３の可動シーブ４２の受圧面積
dPpri/dt：プライマリプーリ３３の可動シーブ４２の移動速度

However, Apri: Pressure receiving area of movable sheave 42 of primary pulley 33
dPpri / dt: moving speed of the movable sheave 42 of the primary pulley 33

  Since the position of the movable sheave 42 corresponds to the rotational speed ratio between the primary pulley 33 and the secondary pulley 34, that is, the transmission ratio, the moving speed dPpri / dt of the movable sheave 42 corresponds to each rotational speed of the primary pulley 33 and the secondary pulley 34 It can be calculated from

ただし、Qpump：オイルポンプ８の単位回転数あたりの吐出能力 Then, the pump rotational speed dNpri / dt necessary to generate the fluid inflow dQpri / dt is calculated according to the following equation (2).

However, Qpump: Discharge capacity per unit number of revolutions of oil pump 8

  Further, the limit value calculation unit 132 calculates the fluid inflow amount dQsec / dt, which is the inflow amount of the hydraulic oil to the piston chamber 48 of the secondary pulley 34, according to the following equation (3).

ただし、Asec：セカンダリプーリ３４の可動シーブ４６の受圧面積
dPsec/dt：セカンダリプーリ３４の可動シーブ４６の移動速度

However, Asec: pressure receiving area of the movable sheave 46 of the secondary pulley 34
dPsec / dt: moving speed of the movable sheave 46 of the secondary pulley 34

  Since the position of the movable sheave 46 corresponds to the rotational speed ratio between the primary pulley 33 and the secondary pulley 34, that is, the transmission ratio, the moving speed dPsec / dt of the movable sheave 46 corresponds to each rotational speed of the primary pulley 33 and the secondary pulley 34 It can be calculated from

  Then, the pump rotational speed dNsec / dt necessary to generate the fluid inflow dQsec / dt is calculated according to the following equation (2).

  Therefore, the pump shaft rotational speed (pump rotational speed) dN / dt required when the hydraulic pressure supplied to the movable sheaves 42 and 46 is changed by the shift control described below is expressed by the following equation (5) Thus, the sum of the pump rotational speed dNpri / dt necessary for the volume change due to the movement of the movable sheave 42 of the primary pulley 33 and the pump rotational speed dNsec / dt required for the volume change due to the movement of the movable sheave 46 of the secondary pulley 34 It becomes a value.

  Then, the pump shaft rotational speed dN / dt is set as the limit value according to the volume change of the primary pulley 33 and the secondary pulley 34, and the pump dischargeable pressure estimating unit 134 determines the pump shaft rotational speed of the oil pump 8 Since the dischargeable pressure of the oil pump 8 is estimated based on the value obtained by subtracting the limit value, the dischargeable pressure of the oil pump 8 can be estimated accurately. As understood from the above equations (1) and (3), the volume change on the hydraulic fluid outflow side does not affect the ability of the oil pump 8, so the limit value (pump shaft rotation speed dN not taken into account.

<Speed change control>
FIG. 5 is a flow chart showing the flow of processing executed by the sheave shift controller.

  The process shown in FIG. 5 is executed for each predetermined control cycle by the ECU 101 functioning as a sheave change controller for shift control.

  In this process, first, the P control value by the P operation with the P gain Kp, the I control value by the I operation with the I gain Ki, and the D control value by the D operation with the D gain Kd are set. The control pressure is calculated by adding the value, the I control value and the D control value (step S1).

  Next, it is determined whether or not the windup amount (previous windup amount) calculated at the time of control one cycle before the current control cycle is a value larger than 0. (Step S2).

  If the previous windup amount is larger than 0 (YES in step S2), the upper limit guard amount setting unit 127 causes the upper limit guard amount to be the minimum value output by the minimum value selection unit 135, that is, the source pressure estimation unit 131 The smaller one of the source pressure estimated value, which is the value of the source pressure to be estimated, and the dischargeable pressure estimated by the pump dischargeable pressure estimation unit 134 is determined (step S3). If the previous windup amount is greater than 0, the control pressure calculated at the time of control one cycle before the current control cycle exceeds the upper limit guard amount, and the control pressure is saturated. .

  On the other hand, if the previous windup amount is 0 or less (NO in step S2), the control pressure calculated during control one cycle before the current control cycle does not exceed the upper limit guard amount, and the control pressure Is not saturated. In this case, the upper limit guard amount setting unit 127 sets the upper limit guard amount to the dischargeable pressure estimated by the pump dischargeable pressure estimation unit 134 (step S4).

  After setting the upper limit guard amount, the upper limit limiting portion 126 compares the set upper limit guard amount with the control pressure output by the control pressure output portion 125, and the smaller one of them is used as the guard control pressure. It is output (step S5).

  After that, the windup amount is calculated by the windup amount calculation unit 128 for use in processing in the next control cycle (step S6).

  Then, the windup amount output from the windup amount calculation unit 128 is fed back to the I operation (step S7), and the series of processing is ended.

<Function effect>
As described above, the control pressure corresponding to the deviation E between the target of the CVT 4 gear ratio and the actual gear ratio is set. By supplying the hydraulic pressure of this control pressure to the movable sheave 42 of the primary pulley 33 and the movable sheave 46 of the secondary pulley 34, the actual gear ratio can be made closer to the target of the gear ratio.

  Since there is a limit to the ability of the oil pump 8 to generate the source pressure of the hydraulic circuit 111, the control pressure has an upper limit. If the control pressure is set beyond the upper limit, the deviation E between the target of the gear ratio and the actual gear ratio is not reduced, and the product of the deviation E and the I gain Ki is used to calculate the I control value by I operation. That is, when used for integration, the deviation E accumulates and increases.

  Therefore, the source pressure generated in the hydraulic circuit 111 and the dischargeable pressure of the oil pump 8 generating the source pressure in the hydraulic circuit 111 are estimated, and the upper limit of the control pressure is limited to the source pressure estimated value or the dischargeable pressure. Therefore, as the source pressure estimated value or the dischargeable pressure is smaller, the guard control pressure which is the control pressure after the limitation based on the source pressure estimated value or the dischargeable pressure is limited to a smaller value. Then, the larger the difference between the control pressure and the guard control pressure, the larger the windup amount obtained by subtracting the guard control pressure from the control pressure, and the multiplication value obtained by multiplying the deviation E by the I gain Ki The I control value calculated by the integral calculation of the deviation from the amplified value of the windup amount output by the V.sub.2 becomes a small value. Thereby, as understood by comparing the solid line shown in FIG. 6 with the broken line and the alternate long and two short dashes line, the configuration in which the windup amount is not fed back to the I operation for calculating the I control value (no anti windup) and control The I-control value can be suppressed to a small value in the above-described configuration of the sheave shift controller, as compared with the configuration in which the windup amount obtained by subtracting the fixed upper limit amount from the pressure is fed back to the I operation. As a result, the restriction of the control pressure can be intensified, the accumulation of the deviation E between the target of the gear ratio and the actual gear ratio can be suppressed, and the followability of the gear control can be improved.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, in the above-mentioned embodiment, ECU101 which controls CVT4 was taken up. However, the transmission to be controlled by the ECU 101 is not limited to the CVT 4 and may be a power split type continuously variable transmission. A power split type continuously variable transmission includes, for example, a belt type continuously variable transmission mechanism that continuously changes the power by changing the gear ratio, and splits the power into two paths between the input shaft and the output shaft. Transmission that can be transmitted.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

4: CVT (transmission)
8: Oil pump 33: Primary pulley (pulley)
35: Belt 41: Fixed sheave 42: Movable sheave 101: ECU (control device)
111: Hydraulic circuit 121: Deviation operation unit (control pressure setting means)
122: P control unit (control pressure setting means)
123: I control unit (control pressure setting means)
124: D control unit (control pressure setting means)
125: Control pressure output unit (control pressure setting means)
126: Upper limit limiting unit (control pressure limiting means)
134: Pump dischargeable pressure estimation unit (dischargeable pressure estimation means)

Claims (1)

A control device for a transmission having a configuration in which an endless belt is wound around a pulley provided with a fixed sheave and a movable sheave whose distance from the fixed sheave is changed by hydraulic pressure supplied to an oil chamber from a hydraulic circuit. ,
Control pressure setting means for setting a control pressure according to a deviation between a target of the transmission gear ratio of the transmission and an actual transmission gear ratio, which is a hydraulic pressure for controlling the position of the movable sheave;
Dischargeable pressure estimation means for estimating the dischargeable pressure of the oil pump that causes the hydraulic circuit to generate the original pressure in consideration of the volume change of the oil chamber due to the movement of the movable sheave;
A control pressure limiting unit configured to limit the control pressure set by the control pressure setting unit based on the dischargeable pressure estimated by the dischargeable pressure estimation unit.

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