JP6653946B2 - Control device for continuously variable transmission - Google Patents

Description

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

  As a transmission mounted on a vehicle, a continuously variable transmission (CVT) 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. Both the primary pulley and the secondary pulley are disposed opposite to each other with the fixed sheave, the fixed sheave sandwiching the belt, and a movable sheave provided movably in the facing direction, and on the opposite side of the movable sheave from the fixed sheave. And an oil chamber to which hydraulic oil for moving the movable sheave is supplied. In the CVT, for example, the distance between the fixed sheave and the movable sheave of the primary pulley is changed by controlling the amount of oil supplied to the oil chamber of the primary pulley with a ratio control valve (flow control valve). Along with this, the winding diameter of the belt around 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 around the secondary pulley changes. Thus, the speed ratio (pulley ratio) continuously changes in a stepless manner.

  The hydraulic circuit of the CVT is provided with an upshift solenoid valve and a downshift solenoid valve in order to control the amount of oil supplied from the ratio control valve to the oil chamber of the primary pulley. The upshift solenoid valve and the downshift solenoid valve generate a signal pressure corresponding to the duty ratio. The upshift signal pressure generated by the upshift solenoid valve and the downshift signal pressure generated by the downshift solenoid valve are input to the ratio control valve, and the upshift signal pressure and the downshift signal pressure are input to the ratio control valve. Is supplied from the ratio control valve to the oil chamber of the primary pulley.

  In such a configuration, since there is individual variation in the solenoid valves for shifting (the solenoid valve for up-shifting and the solenoid valve for down-shifting), there is a problem that even if the same accelerator operation is performed, variation occurs in shifting responsiveness. That is, there is a variation in the relationship between the duty ratio and the signal pressure among the individual solenoid valves for shifting. In the shift control of the CVT, a target input rotation speed (target engine rotation speed) is set according to the accelerator opening, and the shift solenoid is set so that the actual input rotation speed (actual engine rotation speed) matches the target input rotation speed. The duty ratio of the valve is controlled. However, since there is individual variation in the relationship between the duty ratio of the transmission solenoid valve and the signal pressure, the variation in the amount of oil supplied to the oil chamber of the primary pulley occurs even if the same accelerator operation is performed.

  The gain of the shift control is set to an intermediate value in consideration of the occurrence of hunting in which the actual input speed oscillates before and after the target input speed and the ability of the actual input speed to follow the target input speed, Therefore, a satisfactory shift response to the accelerator operation may not be obtained.

JP-A-8-82354

  An object of the present invention is to provide a control device for a continuously variable transmission that can improve shift response.

  In order to achieve the above object, a control device for a continuously variable transmission according to the present invention includes a movable sheave and a movable sheave in which an endless belt is wound around a primary pulley and a secondary pulley, and is movable in a direction to sandwich the belt. A continuously variable solenoid valve provided with an oil chamber to which the hydraulic oil to be moved is supplied, and a shift solenoid valve for outputting a hydraulic pressure for controlling the flow rate of the hydraulic oil supplied to the oil chamber in accordance with the input duty ratio A control device used for a transmission, wherein a target input rotation speed is set in accordance with at least an accelerator opening and a vehicle speed, and a shift is performed so that an actual input rotation speed input to a primary pulley matches the target input rotation speed. Command value output means for outputting a control command value for setting the duty ratio of the solenoid valve for transmission, and output oil for the duty ratio of the solenoid valve for shifting. And at least one of a predetermined value included as at least a part of the control instruction value output from the control instruction value output means with respect to the predetermined shift instruction and the actual input rotation speed with respect to the predetermined shift instruction. A characteristic storage unit that stores the relationship, and a control instruction value output unit that, while the control instruction value is being output, obtains a predetermined value from the control instruction value and / or obtains an actual input rotation speed. Characteristic estimating means for estimating the characteristic of the shift solenoid valve from the stored relationship.

  According to this configuration, in the shift control of the continuously variable transmission, the target input rotational speed according to the accelerator opening and the vehicle speed is set, and the actual input rotational speed input to the primary pulley matches the target input rotational speed. , The duty ratio of the gearshift solenoid valve is set. A control instruction value is output from the control instruction value output means for setting the duty ratio.

  During the shift control, a predetermined value is obtained from the control instruction value output by the control instruction value output means in response to the predetermined shift instruction, or a predetermined value is added to the predetermined value or instead of the predetermined value. An actual input rotation speed corresponding to the shift instruction is obtained. The predetermined value is a value included as at least a part of the control instruction value, and may be the control instruction value itself or a control term (proportional term, integral term) included in the control instruction value. . On the other hand, the characteristic storage means stores the relationship between the characteristic of the output oil pressure with respect to the duty ratio of the shift solenoid valve and at least one of the predetermined value and the actual input rotational speed. When the predetermined value and / or the actual input speed is obtained, the characteristics of the shift solenoid valve according to the predetermined value and / or the actual input speed are estimated based on the relationship stored in the characteristic storage means. .

  By estimating the characteristics of the shift solenoid valve, it is possible to add a correction corresponding to the estimated characteristics to the control instruction value. A duty ratio is set in accordance with the corrected control instruction value, and the shift solenoid valve is controlled by the duty ratio, so that a variation in shift responsiveness due to an individual variation of the shift solenoid valve is reduced. As a result, a favorable shift response in accordance with the accelerator opening and the vehicle speed can be obtained, and the shift feeling and fuel efficiency can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, shift response can be improved and shift feeling and fuel consumption can be improved.

FIG. 2 is a skeleton diagram showing a configuration of a drive system of the vehicle. It is a block diagram showing composition of CVTTECU concerning one embodiment of the present invention. It is an example of a shift diagram. It is a figure which shows the time change of a vehicle speed, an input rotation speed (target input rotation speed, actual rotation speed), and a control instruction value. It is a figure which shows the characteristic of the output oil pressure with respect to the input duty ratio of the solenoid valve for speed change. FIG. 4 is a diagram illustrating a relationship between a control instruction value and a characteristic value corresponding to a characteristic of a shift solenoid valve. It is a figure showing the contents of a conversion map.

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

<Configuration of CVT>

  FIG. 1 is a skeleton diagram showing a configuration of a drive system of the vehicle 1.

  The vehicle 1 is an automobile using an engine (E / G) 2 as a power source. The vehicle 1 has a torque converter 3 and a CVT 4 mounted thereon.

  The engine 2 has an E / G output shaft 21. The E / G output shaft 21 is rotated by power generated by the engine 2.

  The torque converter 3 includes a pump impeller 31, a turbine runner 32, and a lock-up clutch 33. The E / G output shaft 21 is connected to the pump impeller 31, and the pump impeller 31 is provided so as to be integrally rotatable about the same rotation axis as the E / G output shaft 21. The turbine runner 32 is provided rotatable about the same rotation axis as the pump impeller 31. The lock-up clutch 33 is provided for directly connecting / disconnecting the pump impeller 31 and the turbine runner 32. When the lock-up clutch 33 is engaged, the pump impeller 31 and the turbine runner 32 are directly connected. When the lock-up clutch 33 is released, the pump impeller 31 and the turbine runner 32 are separated.

  When the E / G output shaft 21 is rotated in a state where the lock-up clutch 33 is released, the pump impeller 31 rotates. When the pump impeller 31 rotates, oil flows from the pump impeller 31 to the turbine runner 32. This oil flow is received by the turbine runner 32, and the turbine runner 32 rotates. At this time, an amplification action of the torque converter 3 occurs, and a torque larger than the torque of the E / G output shaft 21 is generated in the turbine runner 32.

  In a state where the lock-up clutch 33 is engaged, when the E / G output shaft 21 is rotated, the E / G output shaft 21, the pump impeller 31, and the turbine runner 32 rotate integrally.

  An oil pump 5 is provided between the torque converter 3 and the CVT 4. The pump shaft of the oil pump 5 is provided so as to be able to rotate integrally with the pump impeller 31. Thus, when the pump impeller 31 is rotated by the power of the engine 2, the pump shaft of the oil pump 5 rotates, and oil is discharged from the oil pump 5.

  The CVT 4 includes an input shaft 41, an output shaft 42, a belt transmission mechanism 43, and a forward / reverse switching mechanism 44.

  The input shaft 41 is connected to the turbine runner 32 of the torque converter 3, and is provided so as to be integrally rotatable about the same rotation axis as the turbine runner 32.

  The output shaft 42 is provided in parallel with the input shaft 41. An output gear 45 is supported by the output shaft 42 so as not to rotate relatively. The output gear 45 meshes with the ring gear 7 of the differential gear 6.

  The belt transmission mechanism 43 includes a primary shaft 51 connected to the input shaft 41, a secondary shaft 52 provided in parallel with the primary shaft 51, a primary pulley 53 supported by the primary shaft 51 so as not to rotate relatively, and a secondary shaft 51. The secondary pulley 54 includes a secondary pulley 54 supported so as to be relatively non-rotatable, and a belt 55 wound around the primary pulley 53 and the secondary pulley 54.

  The primary pulley 53 is opposed to a fixed sheave 61 fixed to the primary shaft 51 with a belt 55 interposed between the fixed sheave 61 and a movable sheave supported on the primary shaft 51 so as to be movable in its axial direction and relatively non-rotatable. 62. A piston 63 fixed to the primary shaft 51 is provided on a side opposite to the fixed sheave 61 with respect to the movable sheave 62, and an oil chamber 64 is formed between the movable sheave 62 and the piston 63.

  The secondary pulley 54 is opposed to a fixed sheave 65 fixed to the secondary shaft 52 and a fixed sheave 65 with a belt 55 interposed therebetween, and is a movable sheave supported on the secondary shaft 52 so as to be movable in its axial direction and relatively non-rotatable. 66. A piston 67 fixed to the secondary shaft 52 is provided on the opposite side of the movable sheave 66 from the fixed sheave 61, and an oil chamber 68 is formed between the movable sheave 66 and the piston 67.

  The forward / reverse switching mechanism 44 is interposed between the input shaft 41 and the primary shaft 51 of the belt transmission mechanism 43. The forward / reverse switching mechanism 44 includes a planetary gear mechanism 71, a reverse clutch C1, and a forward brake B1.

  The planetary gear mechanism 71 includes a carrier 72, a sun gear 73, and a ring gear 74.

  The carrier 72 is supported by the input shaft 41 so as to be relatively rotatable. The carrier 72 rotatably supports a plurality of pinion gears 75. The plurality of pinion gears 75 are arranged on the circumference.

  The sun gear 73 is supported by the input shaft 41 so as not to rotate relatively, and is arranged in a space surrounded by the plurality of pinion gears 75. The gear teeth of the sun gear 73 mesh with the gear teeth of each pinion gear 75.

  The ring gear 74 is provided such that its rotation axis coincides with the axis of the primary shaft 51. The primary shaft 51 of the belt transmission mechanism 43 is connected to the ring gear 74. The gear teeth of the ring gear 74 are formed so as to enclose the plurality of pinion gears 75 collectively, and mesh with the gear teeth of each pinion gear 75.

  The reverse clutch C1 is provided between the carrier 72 and the sun gear 73.

  Forward brake B1 is provided between carrier 72 and a transmission case accommodating torque converter 3 and CVT4.

  When the vehicle 1 moves forward, the reverse clutch C1 is released and the forward brake B1 is engaged. When the power of the engine 2 is input to the input shaft 41, the sun gear 73 rotates integrally with the input shaft 41 with the carrier 72 stationary. Therefore, the rotation of the sun gear 73 is transmitted to the ring gear 74 in the reverse direction and at a reduced speed. Accordingly, the ring gear 74 rotates, and the primary shaft 51 and the primary pulley 53 of the belt transmission mechanism 43 rotate integrally with the ring gear 74. The rotation of the primary pulley 53 is transmitted to the secondary pulley 54 via the belt 55, and rotates the secondary pulley 54 and the secondary shaft 52. Then, the output shaft 42 and the output gear 45 rotate integrally with the secondary shaft 52. When the rotation of the output gear 45 is transmitted to the ring gear 7 of the differential gear 6, the drive shafts 81 and 82 extending left and right from the differential gear 6 rotate, and the drive wheels (not shown) rotate, so that the vehicle moves forward. I do.

  On the other hand, when the vehicle 1 is moving backward, the reverse clutch C1 is engaged, and the forward brake B1 is released. When the power of the engine 2 is input to the input shaft 41, the carrier 72 and the sun gear 73 rotate integrally with the input shaft 41. Therefore, the rotation of the sun gear 73 is transmitted to the ring gear 74 without the rotation direction being reversed. As a result, the ring gear 74 rotates in a direction opposite to the direction in which the vehicle 1 advances, and the primary shaft 51 and the primary pulley 53 of the belt transmission mechanism 43 rotate integrally with the ring gear 74. The rotation of the primary pulley 53 is transmitted to the secondary pulley 54 via the belt 55, and rotates the secondary pulley 54 and the secondary shaft 52. Then, the output shaft 42 and the output gear 45 rotate integrally with the secondary shaft 52. When the rotation of the output gear 45 is transmitted to the ring gear 7 of the differential gear 6, the drive shafts 81 and 82 extending left and right from the differential gear 6 rotate in the opposite direction to the forward movement, and the drive wheels (not shown) rotate. As a result, the vehicle moves backward.

  In the CVT 4, the oil pressure supplied to the oil chamber 64 of the primary pulley 53 and the oil chamber 68 of the secondary pulley 54 is controlled, and the groove ratio of the primary pulley 53 and the secondary pulley 54 is changed, so that the gear ratio is continuously changed. It is changed steplessly.

  Specifically, when the gear ratio is reduced, the hydraulic pressure supplied to oil chamber 64 of primary pulley 53 is increased. As a result, the movable sheave 62 of the primary pulley 53 moves toward the fixed sheave 61, and the distance (groove width) between the fixed sheave 61 and the movable sheave 62 decreases. Along with this, the winding diameter of the belt 55 around the primary pulley 53 increases, and the distance (groove width) between the fixed sheave 65 and the movable sheave 66 of the secondary pulley 54 increases. As a result, the pulley ratio between the primary pulley 53 and the secondary pulley 54 decreases, and the speed ratio decreases.

  When the gear ratio is increased, the hydraulic pressure supplied to oil chamber 64 of primary pulley 53 is reduced. As a result, the thrust of the secondary pulley 54 on the belt 55 becomes larger than the thrust of the primary pulley 53 on the belt 55, the distance between the fixed sheave 65 and the movable sheave 66 of the secondary pulley 54 becomes smaller, and the fixed sheave 61 and the movable sheave The distance from the gap 62 increases. As a result, the pulley ratio between the primary pulley 53 and the secondary pulley 54 increases, and the gear ratio increases.

  On the other hand, the thrust of the primary pulley 53 and the secondary pulley 54 needs to be large enough to prevent slippage between the primary pulley 53 and the secondary pulley 54 and the belt 55. Therefore, the hydraulic pressure supplied to the oil chamber 64 of the primary pulley 53 and the oil chamber 68 of the secondary pulley 54 is controlled so that a thrust according to the magnitude of the torque input to the input shaft 41 is obtained.

<Control device>

  FIG. 2 is a block diagram showing a configuration of the CVT ECU 101 according to one embodiment of the present invention.

  The vehicle 1 includes a plurality of ECUs (electronic control units) each including a CPU and a memory (a ROM, a RAM, a flash memory, an EEPROM, or the like). The ECU includes a CVT ECU 101 for controlling the CVT 4. The plurality of ECUs are connected so as to be capable of bidirectional communication using a CAN (Controller Area Network) communication protocol.

  An input speed sensor 102 and an output speed sensor 103 are connected to the CVT ECU 101.

  The input rotation speed sensor 102 inputs a pulse signal synchronized with the rotation of the input shaft 41 to the CVT ECU 101. The CVT ECU 101 converts the frequency of the pulse signal input from the input speed sensor 102 into an actual input speed, which is the speed of the input shaft 41.

  The output rotation speed sensor 103 inputs a pulse signal synchronized with the rotation of the output shaft 42 to the CVT ECU 101. The CVT ECU 101 converts the frequency of the pulse signal input from the output speed sensor 103 into an actual output speed, which is the speed of the output shaft 42. Further, the CVT ECU 101 calculates the vehicle speed of the vehicle 1 from the output rotation speed based on the final gear ratio and the like.

  The CVT ECU 101 receives information on the accelerator opening from another ECU, for example, an engine ECU that controls the engine 2.

  The CVT ECU 101 controls the amount of oil supplied to the oil chamber 64 of the primary pulley 53 for the shift control of the CVT 4 based on the actual input speed, the actual output speed, and the accelerator opening. Specifically, a hydraulic circuit for supplying hydraulic pressure to each section of the CVT 4 is provided with a ratio control valve (not shown) for controlling the amount of oil supplied to the oil chamber 64 of the primary pulley 53. An upshift solenoid valve 104 and a downshift solenoid valve 105 are provided to control the ratio control valve. The up-shift solenoid valve 104 and the down-shift solenoid valve 105 are duty solenoid valves that generate a signal pressure (oil pressure) according to the duty ratio. The upshift signal pressure generated by the upshift solenoid valve 104 and the downshift signal pressure generated by the downshift solenoid valve 105 are input to the ratio control valve, and the upshift signal pressure and the downshift signal pressure are generated. Hydraulic oil at a flow rate according to the relative relationship of the signal pressure is supplied from the ratio control valve to the oil chamber 64 of the primary pulley 53.

  The CVT ECU 101 includes a target input rotation speed setting unit 111, a PID (Proportional-Integral-Derivative) controller unit 112, a steady state determination unit 113, a sheave moving speed calculation unit 114, a solenoid characteristic estimation unit 115, A target characteristic storage unit 116, a learning correction unit 117, and a duty setting unit 118 are substantially provided. These processing units are realized by software by program processing or realized by hardware such as a logic circuit.

  The target input speed setting unit 111 sets a target input speed in accordance with the throttle opening and the vehicle speed based on the shift diagram shown in FIG. The shift diagram is mapped and stored in the memory of the CVT ECU 101.

  The deviation between the target input speed set by the target input speed setting unit 111 and the actual speed is input to the PID controller 112. The PID controller 112 outputs a control instruction value according to a deviation between a target input rotation speed and an actual rotation speed by a proportional operation, an integral operation, and a differential operation.

  The accelerator opening, the target input rotation speed set by the target input rotation speed setting unit 111, and the control instruction value output from the PID controller unit 112 are input to the steady state determination unit 113.

  FIG. 4 is a diagram showing changes over time of the vehicle speed, the input rotation speed (target input rotation speed, actual rotation speed), and the control instruction value.

  While the vehicle 1 is traveling at a vehicle speed higher than the predetermined speed α, the depression of the accelerator pedal is released from the depressed state, and then the vehicle 1 continues coasting without depressing the accelerator pedal. The change over time of the input rotation speed and the control instruction value will be described.

  When the accelerator opening decreases to 0%, an upshift is started, the target input rotation speed is reduced, and the vehicle speed and the actual input rotation speed begin to decrease (time T1). During the upshift, the target input rotational speed is set to a predetermined rotational speed according to the accelerator opening and the vehicle speed, and a control instruction value is output from the PID controller 112 in order to follow the actual input rotational speed. At the beginning of the upshift, the control instruction value decreases with the lapse of time (time T1-T2), and as the upshift proceeds, the time change of the control instruction value decreases (time T2). Thereafter, when the target input rotation speed decreases to the predetermined rotation speed, the target input rotation speed is maintained at the predetermined rotation speed, and the control instruction value decreases as time elapses (time T3-T4).

  When the vehicle speed decreases to the predetermined speed α, a downshift is started (time T4). During the downshift, the target input speed is maintained at a predetermined speed. At the beginning of the downshift, the control instruction value increases with the passage of time (time T4 to T5), and as the downshift proceeds, the time change of the control instruction value decreases (time T5). The state where the time change of the value is small continues.

  The steady state determination unit 113 determines that the accelerator opening is 0%, the target input speed decreases with time, and the control instruction value has a small time change, that is, the time T2 shown in FIG. The state at -T3 is determined to be a steady state at the time of the upshift. Further, the accelerator opening is 0%, the target input rotational speed is constant, and the time variation of the control instruction value is small, that is, the state after time T5 shown in FIG. Judge as the state.

  The actual input rotation speed and the actual output rotation speed are input to the sheave moving speed calculation unit 114, as shown in FIG. The sheave moving speed calculation unit 114 calculates a gear ratio from the actual input rotational speed and the actual output rotational speed, and calculates the gear speed of the gear ratio as the sheave moving speed.

  The control instruction value output from the PID controller 112, the determination result by the steady state determination unit 113, and the sheave moving speed calculated by the sheave moving speed calculation unit are input to the solenoid characteristic estimation unit 115.

  FIG. 5 is a diagram showing characteristics of output hydraulic pressure with respect to input duty ratios of the upshift solenoid valve 104 and the downshift solenoid valve 105.

  The upshift solenoid valve 104 and the downshift solenoid valve 105 (hereinafter collectively referred to as “shift solenoid valves 104 and 105”) have individual variations in the characteristics of the output hydraulic pressure with respect to the input duty ratio.

  Specifically, the characteristics of the shift solenoid valves 104 and 105 vary between a lower limit characteristic indicated by a two-dot chain line and an upper limit characteristic indicated by a one-dot chain line. The lower limit characteristic has a larger duty ratio when the output hydraulic pressure rises than the central characteristic indicated by the solid line. Therefore, the transmission solenoid valves 104 and 105 having characteristics closer to the lower limit characteristic have smaller output oil pressures for the same duty ratio than the transmission solenoid valves 104 and 105 having central characteristics. The upper limit characteristic has a smaller duty ratio when the output hydraulic pressure rises than the central characteristic. Therefore, the shift solenoid valves 104 and 105 having characteristics close to the upper limit characteristic have a larger output oil pressure for the same duty ratio than the shift solenoid valves 104 and 105 having central characteristics.

  FIG. 6 is a diagram showing a relationship between the control instruction value and a characteristic value corresponding to the characteristics of the shift solenoid valves 104 and 105.

  By assigning a numerical range having a predetermined lower limit and upper limit to the characteristics of the shift solenoid valves 104 and 105 between the lower limit characteristic and the upper limit characteristic shown in FIG. The characteristic of 105 is quantified as a characteristic value corresponding to each characteristic. Then, the relationship between the characteristic value and the control instruction value is determined in advance, and the relationship is stored in the memory of the CVT ECU 101.

  During an upshift, the solenoid characteristic estimating unit 115 outputs the control instruction value while the steady state determining unit 113 determines that the vehicle is in the steady state, provided that the target gear ratio (target pulley ratio) is at the upshift end. Then, a characteristic value corresponding to the control instruction value is obtained from the relationship shown in FIG. Also, during downshifting, the solenoid characteristic estimating unit 115 acquires the control instruction value while the steady state determining unit 113 determines that the vehicle is in the steady state, for example, on condition that the sheave moving speed is constant or monotonically increasing. Then, the characteristic value corresponding to the control instruction value is obtained from the relationship shown in FIG.

  The target characteristic storage unit 116 is configured by a memory, and stores a target characteristic value that is a characteristic value corresponding to the target characteristic of the shift solenoid valves 104 and 105.

  The deviation between the target characteristic value stored in the target characteristic storage unit 116 and the characteristic value obtained by the solenoid characteristic estimating unit 115 is input to the learning correction unit 117. The learning correction unit 117 sets a correction value of the control instruction value output from the PID controller 112 so that the input deviation approaches 0, and stores the set correction value in the memory as a learning value.

  The control instruction value output from the PID controller unit 112 and the learning value read from the memory by the learning correction unit 117 are input to the duty setting unit 118.

  FIG. 7 is a diagram showing the contents of the conversion map.

  The memory of the CVT ECU 101 stores a conversion map that defines the correspondence between the control instruction value and the duty ratio to be input to the shift solenoid valves 104 and 105. In the conversion map, even if the control instruction value is 0, the minimum value of the duty ratio is set to 0 so that the duty ratio input to the shift solenoid valves 104 and 105 is set to a value larger than 0. Offset.

  The duty setting unit 118 adds the learning value read from the memory by the learning correction unit 117 to the control instruction value output from the PID controller unit 112, and sets a duty ratio according to the added value according to the conversion map. The duty ratio set in accordance with the added value of the control instruction value and the learning value is different from the duty ratio set in accordance with the control instruction value with respect to the gear ratio as shown by the two-dot chain line in FIG. The value is corrected in accordance with the target characteristics of the solenoid valves 104 and 105. The duty setting unit 118 inputs the set duty ratio to the shift solenoid valves 104 and 105.

  When a duty ratio is input to the up-shift solenoid valve 104, a hydraulic pressure corresponding to the duty ratio is output from the up-shift solenoid valve 104 as an up-shift signal pressure, and the up-shift signal pressure is input to the ratio control valve. Is done. When the duty ratio is input to the down-shift solenoid valve 105, a hydraulic pressure corresponding to the duty ratio is output from the down-shift solenoid valve 105 as a down-shift signal pressure, and the down-shift signal pressure is input to the ratio control valve. Is done. Then, by supplying hydraulic oil from the ratio control valve to the oil chamber 64 of the primary pulley 53, the speed ratio of the CVT 4 is shifted so that the actual output speed matches the target input speed.

<Effects>

  As described above, in the shift control of the CVT 4, the target input rotation speed is set according to the accelerator opening and the vehicle speed, and the actual input rotation speed input to the primary pulley 53 is adjusted to match the target input rotation speed. The duty ratio of the solenoid valves 104 and 105 is set. A control instruction value is output from the PID controller 112 for setting the duty ratio.

  During the shift control, a control instruction value output from the PID controller unit 112 is obtained. On the other hand, the memory of the CVT ECU 101 stores a relationship between the control instruction value and a characteristic value corresponding to the characteristics of the shift solenoid valves 104 and 105. When the control instruction value is obtained, a characteristic value corresponding to the control instruction value is obtained based on the relationship stored in the memory.

  Then, the control command value output from the PID controller unit 112 is corrected according to a characteristic value corresponding to the characteristics of the shift solenoid valves 104 and 105. A duty ratio according to the corrected control instruction value is set, and the solenoid valves 104 and 105 for shifting are controlled by the duty ratio. Thus, the variation in the shift response due to the individual variation of the shift solenoid valves 104 and 105 is reduced. As a result, a favorable shift response in accordance with the accelerator opening and the vehicle speed can be obtained, and the shift feeling and fuel efficiency can be improved.

  Further, since the correction value corresponding to the characteristics of the shift solenoid valves 104 and 105 is unique to each individual, there is no need to perform learning correction for each engine torque range. Therefore, the program for the learning correction is simple.

<Modification>

  As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented in another form.

  For example, in the above-described embodiment, the memory of the CVT ECU 101 stores the relationship between the control instruction value and the characteristic value corresponding to the characteristics of the shift solenoid valves 104 and 105, and based on the relationship, the PID controller unit. It is assumed that a characteristic value corresponding to the control instruction value output from 112 is obtained.

  However, the relationship between the proportional term (deviation) included in the control instruction value and the characteristic value corresponding to the characteristics of the shift solenoid valves 104 and 105 is obtained in advance, and the relationship is stored in the memory of the CVT ECU 101. Therefore, a proportional term (deviation) is obtained from the control instruction value output from the PID controller unit 112, and a characteristic value corresponding to the proportional term (deviation) is obtained based on the relationship stored in the memory. Good.

  In addition, the relationship between the integral term included in the control instruction value and the characteristic value corresponding to the characteristics of the shift solenoid valves 104 and 105 is obtained in advance, and the relationship is stored in the memory of the CVT ECU 101. , An integral term may be obtained from the control instruction value output from, and a characteristic value corresponding to the integral term may be obtained based on the relationship stored in the memory.

  In addition, the relationship between the actual input rotation speed and the characteristic value corresponding to the characteristics of the shift solenoid valves 104 and 105 with respect to a predetermined shift instruction (for example, shift at a duty ratio of 50%) is obtained in advance, and the relationship is determined. The actual input rotational speed is stored in the memory of the CVT ECU 101, is obtained from the output signal of the input rotational speed sensor 102 during the output of the predetermined shift instruction, and is based on the relationship stored in the memory. A corresponding characteristic value may be obtained.

  In the above-described embodiment, one of the conditions for determining the steady state at the time of an upshift and at the time of a downshift includes a condition that the time change of the control instruction value is small. However, normally, when a predetermined time elapses from the start of the upshift and the downshift, the time change of the control instruction value becomes small. Instead of the condition that the time change of the value is small, a condition that a predetermined time has elapsed from the start of the upshift and the downshift may be included.

  In the above-described embodiment, the correction value of the control instruction value output from the PID controller unit 112 is set, and the correction value is stored in the memory as the learning value. Is stored in the memory as a learning value, and the PID controller is controlled so that the deviation between the characteristic value stored in the memory and the target characteristic value stored in the target characteristic storage unit 116 approaches zero. A correction value of the control instruction value output from unit 112 may be set.

  Further, the configuration provided with the PID controller unit 112 for executing the proportional operation, the integral operation and the differential operation is taken as an example. However, instead of the PID controller unit 112, the target input rotation speed and the actual A controller may be provided that outputs a control instruction value according to a deviation from the rotation speed, or a controller that outputs a control instruction value according to a deviation between the target input rotation speed and the actual rotation speed only by proportional operation. A unit may be provided.

  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 (Continuously variable transmission)
53 Primary pulley 54 Secondary pulley 55 Belt 61 Fixed sheave 62 Movable sheave 64 Oil chamber 101 CVT ECU (Vehicle control device)
104 Upshift solenoid valve (shift solenoid valve)
105 Downshift solenoid valve (shift solenoid valve)
111 Target input rotation speed setting unit (control instruction value output means)
112 PID controller unit (control instruction value output means)
115 Solenoid characteristic estimation unit (characteristic storage means, characteristic estimation means)

Claims (1)

An endless belt is wound around a primary pulley and a secondary pulley, and a movable sheave movable in a direction to sandwich the belt and an oil chamber to which hydraulic oil for moving the movable sheave is supplied are provided. A control device used in a continuously variable transmission provided with a shift solenoid valve that outputs a hydraulic pressure for controlling a flow rate of hydraulic oil supplied to the oil chamber in accordance with the
At least a target input rotation speed according to the accelerator opening and the vehicle speed is set, and a duty ratio of the shift solenoid valve is set such that an actual input rotation speed input to the primary pulley matches the target input rotation speed. Control instruction value output means for outputting a control instruction value for performing
And characteristics of the output hydraulic pressure with respect to the duty ratio of the speed-change solenoid valves, said with respect to the control command value control instruction value you and the predetermined shift instruction outputted from the output means to a predetermined gear change command actual input revolution speed of at least Characteristic storage means for storing a relationship with any one of them,
While the vehicle equipped with the continuously variable transmission is running and performing shift control, and while the control instruction value is being output from the control instruction value output means, the control instruction value is acquired and / or the actual input value is obtained. A control unit for a continuously variable transmission, comprising: a characteristic estimating unit configured to acquire a rotational speed and estimate the characteristic of the shift solenoid valve from the relationship stored in the characteristic storing unit.

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