JP6120319B2 - Control device for continuously variable transmission - Google Patents

Description

  The present invention relates to a control device for a continuously variable transmission that controls a clamping force for preventing slippage of a power transmission member such as a power roller or a metal belt in a toroidal type continuously variable transmission or a belt type continuously variable transmission.

  A toroidal continuously variable transmission that changes the gear ratio steplessly by tilting a power roller clamped between the input disk and the output disk, or a drive pulley and drive pulley connected by an endless belt. In a belt-type continuously variable transmission that changes the gear ratio steplessly by changing the effective radius of the pulley, when the continuously variable transmission enters the neutral state, the clamping pressure for clamping the power roller or the endless belt is clamped. It is known from Patent Document 1 below that the driving energy of the hydraulic pump that generates the clamping pressure is reduced by reducing the clamping pressure.

JP 2001-200904 A

  By the way, in a toroidal type continuously variable transmission, for example, the input disk is biased toward the output disk by the hydraulic pressure supplied to the oil chamber, thereby preventing the power roller slipped between the input disk and the output disk from slipping. The clamping pressure is set according to the input torque input from the engine to the toroidal continuously variable transmission.

  However, when the oil pressure acting on the oil chamber increases or decreases, the wall section that partitions the oil chamber elastically deforms due to the oil pressure, and the volume of the oil chamber increases or decreases, so the oil pressure that is set according to the input torque simply acts on the oil chamber. If this is done, the clamping pressure generated by the hydraulic pressure will change as much as the volume of the oil chamber changes, the clamping pressure will be insufficient, the power roller will slip, or the clamping pressure will be excessive and the oil pump will be driven. There was a problem that the driving force was wasted.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to generate an appropriate clamping pressure for clamping a power transmission member by compensating for a volume change of an oil chamber of a continuously variable transmission.

In order to achieve the above object, according to the first aspect of the present invention, a power transmission member is clamped between a pair of clamping members of a continuously variable transmission with a predetermined clamping pressure, and the pair of clamping members And a continuously variable transmission control device that changes a gear ratio by changing a contact position of the power transmission member, wherein the clamping pressure control means for controlling the clamping pressure is an actual input to the continuously variable transmission. Reference clamping pressure setting means for setting a reference clamping pressure for preventing slip from occurring between the pair of clamping members and the power transmission member based on torque, and to the continuously variable transmission according to a driver's request degree Target input torque calculating means for calculating the target input torque, target speed ratio calculating means for calculating the target speed ratio of the continuously variable transmission according to the degree of demand of the driver, the target input torque and the target speed ratio Based on the target input And a required clamping pressure calculation means for calculating a required clamping pressure required when the torque and the target gear ratio are reached, and an actual speed of the continuously variable transmission based on the input rotational speed and the output rotational speed of the continuously variable transmission. It calculates the actual gear ratio calculating means for calculating a speed ratio, the required clamping force, on the basis of the target speed ratio and the actual gear ratio, the volumetric change due to elastic deformation of the wall of the oil chamber to generate a clamping force A volume change amount calculating means; and a pinching pressure correcting means for correcting the reference pinching pressure based on the volume change amount , wherein the pinching pressure correction means is configured such that when the volume of the oil chamber increases, A control device for a continuously variable transmission is proposed, in which the pressure is corrected so as to increase, and when the volume of the oil chamber decreases, the reference clamping pressure is corrected so as to decrease .

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the continuously variable transmission includes an input disk that is the pressing member that rotates together with the input shaft, and a relative rotation with respect to the input shaft. An output disk that is freely supported by the clamping member, a power roller that is the power transmission member that is clamped between the input disk and the output disk, a trunnion that supports the power roller, and the trunnion And driving the trunnion in the trunnion axis direction with the hydraulic actuator, and swinging the power roller about the trunnion axis to change the position of the contact point between the input disk and the output disk. Thus, a control device for a continuously variable transmission is proposed in which the speed ratio is changed.

  The input disk 15, the output disk 16, the drive pulley 115, and the driven pulley 117 according to the embodiment correspond to the pinching member of the present invention, and the power roller 19 and the metal belt 119 according to the embodiment are the power transmission member of the present invention. The first oil chamber 27 and the second oil chamber 28 of the embodiment correspond to the oil chamber of the present invention, and the adding means M9 of the embodiment corresponds to the clamping pressure correcting means of the present invention. The toroidal type continuously variable transmission T and the belt type continuously variable transmission of the form correspond to the continuously variable transmission of the present invention, and the electronic control unit U of the embodiment corresponds to the clamping pressure control means of the present invention.

According to the configuration of the first aspect, the reference clamping pressure setting means sets the reference clamping pressure for preventing the slip between the pair of clamping members and the power transmission member based on the actual input torque to the continuously variable transmission. Then, the target input torque calculation means calculates the target input torque to the continuously variable transmission according to the driver's request degree, and the target gear ratio calculation means calculates the continuously variable transmission of the continuously variable transmission according to the driver's request degree. The target transmission ratio is calculated, and the required clamping pressure calculation means calculates the required clamping pressure required when the target input torque and the target transmission ratio are reached based on the target input torque and the target transmission ratio, The ratio calculation means calculates the actual transmission ratio of the continuously variable transmission based on the input rotation speed and the output rotation speed of the continuously variable transmission, and the volume change amount calculation means calculates the required clamping pressure, the target transmission ratio, and the actual transmission speed. based on the ratio, the oil for generating the clamping force Volume of calculating the volumetric change due to elastic deformation of the wall, the clamping force compensation unit, the so corrects the reference clamping pressure based on the volumetric change, even the volume of the oil chamber is changed by hydraulic pressure, the oil chamber By correcting the reference clamping pressure by feed-forward control so as to compensate for the change, it is possible to generate a clamping pressure without excess or deficiency to prevent the power transmission member from slipping and to reduce the driving force for generating hydraulic pressure. can not only improve the efficiency of the continuously variable transmission, the heating value reduction, can contribute to improvement of durability.

In addition, the clamping pressure correction means corrects the reference clamping pressure to increase when the volume of the oil chamber increases, and corrects the reference clamping pressure to decrease when the volume of the oil chamber decreases. Even if the volume of the oil chamber changes, an appropriate clamping pressure can be generated.

According to the second aspect of the present invention, the continuously variable transmission includes an input disk that is a pressing member that rotates together with the input shaft, an output disk that is a pressing member that is rotatably supported by the input shaft, and an input disk. Since the toroidal continuously variable transmission includes a power roller that is a power transmission member sandwiched between the disks, a trunnion that supports the power roller, and a hydraulic actuator that drives the trunnion, the trunnion is driven by the hydraulic actuator. The gear ratio can be changed by driving in the direction of the trunnion axis and swinging the power roller around the trunnion axis to change the position of the contact point between the input disk and the output disk. Toroidal-type continuously variable transmissions have a high speed ratio changing speed, so there is a problem that the responsiveness decreases when feedback control is performed on the clamping pressure. Even a fast toroidal-type continuously variable transmission can follow the clamping pressure without delaying the change in the gear ratio.

The skeleton figure of a toroidal type transmission mechanism. (First embodiment) The principal part enlarged view of FIG. (First embodiment) FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. (First embodiment) The block diagram of the control system of clamping pressure. (First embodiment) The graph which shows the relationship between pinching pressure and the volume of an oil chamber. (First embodiment) The skeleton figure of a belt type continuously variable transmission. (Second Embodiment)

First embodiment

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, the toroidal-type continuously variable transmission T for an automobile includes an input shaft 13 connected to a crankshaft 11 of an engine E via a damper 12. The first continuously variable transmission mechanism 14F and the second continuously variable transmission mechanism 14R having substantially the same structure are supported. The first continuously variable transmission mechanism 14F includes a substantially cone-shaped input disk 15 fixed to the input shaft 13, and a substantially cone-shaped output disk 16 supported on the input shaft 13 so as to be relatively rotatable and axially slidable. , A pair of trunnions 17 and 17 disposed so as to sandwich the input shaft 13, a pair of crank-shaped pivot shafts 18 and 18 rotatably supported at one end by the trunnion 17, and the other ends of the pivot shafts 18 and 18 And a pair of power rollers 19, 19 that can be rotatably supported by the input disc 15 and the output disc 16.

  Opposing surfaces of the input disk 15 and the output disk 16 are formed by toroidal curved surfaces. When the pair of trunnions 17 and 17 move in the opposite directions along the trunnion shafts 21 and 21, the pair of power rollers 19 and 19 are It tilts around the trunnion shafts 21 and 21, and the contact points of the power rollers 19 and 19 with the input disk 15 and the output disk 16 change.

  The second continuously variable transmission mechanism 14R is disposed substantially in plane symmetry with the first continuously variable transmission mechanism 14F across the drive gear 22, and the output disks of the first and second continuously variable transmission mechanisms 14F and 14R. 16, 16 and the drive gear 22 are integrally formed. However, the input disk 15 of the first continuously variable transmission mechanism 14F is fixed to the input shaft 13, whereas the input disk 15 of the second continuously variable transmission mechanism 14R is not rotatable relative to the input shaft 13 and moves in the axial direction. They are spline-coupled so as to be urged in the axial direction by the hydraulic loader 23.

  The hydraulic loader 23 protrudes from the input disk 15 in the axial direction, a cylinder 24 fixed to the input shaft 13, a first piston 25 slidably supported on the cylinder 24 and the input shaft 13, respectively. An annular cylinder portion 15a contacting the first piston 25, a second piston 26 whose outer periphery is slidably supported by the cylinder portion 15a and whose inner periphery is locked to the input shaft 13, the cylinder 24 and the first A first oil chamber 27 defined between the pistons 25 and a second oil chamber 28 defined between the input disk 15 and the second piston 26 are provided.

  Accordingly, in FIG. 2, the hydraulic pressure supplied to the first oil chamber 27 drives the first piston 25 in the right direction with respect to the cylinder 24 and urges the input disk 15 of the second continuously variable transmission mechanism 14R to the right. The hydraulic pressure supplied to the second oil chamber 28 urges the input disk 15 of the second continuously variable transmission mechanism 14R to the right with respect to the second piston 26. As a result, the power rollers 19, 19 are clamped between the input disk 15 and the output disk 16 of the second continuously variable transmission mechanism 14R, and the power between the input disk 15 and the output disk 16 of the first continuously variable transmission mechanism 14F. The rollers 19 and 19 are pinched, and a pinching pressure that suppresses slippage between the input disks 15 and 15 and the output disks 16 and 16 and the power roller 19 can be generated.

  The first continuously variable transmission mechanism 14F (or the second continuously variable transmission mechanism 14R) includes a pair of hydraulic actuators 33 and 33 provided in the hydraulic control blocks 31 and 32. Each hydraulic actuator 33 is formed integrally with the lower part of the trunnion 17, and is supported on the lower support plate 29 via roller bearings 30, 30 so as to be rotatable and slidable up and down, and to the hydraulic control block 31. The formed cylinder 35, the piston 36 that is integrally formed with the piston rod 34 and slidably fits into the cylinder 35, the speed increasing oil chamber 37 that is partitioned on the upper and lower sides of the piston 36, and the piston 36 And a speed reducing oil chamber 38 partitioned on the other upper and lower sides.

  The upper ends of a total of four trunnions 17 are pivotally supported at the four corners of the upper support plate 40 through spherical joints 39, respectively. The two trunnions 17 and 17 are moved up to the other two trunnions. When 17, 17 moves downward, the movement is synchronized.

  The hydraulic pressure generated by the oil pump 41 is regulated by the hydraulic control circuit 42 and supplied to the hydraulic actuators 33. When a high pressure is supplied to the speed increasing oil chamber 37 and a low pressure is supplied to the deceleration oil chamber 38, the piston 36 and the piston rod 34 move in one direction in the vertical direction, and conversely, the high pressure is supplied to the speed reducing oil chamber 38. When a low pressure is supplied to the speed increasing oil chamber 38, the piston 36 and the piston rod 34 move in the other direction in the vertical direction.

  For example, when the pair of trunnions 17 and 17 of the first continuously variable transmission mechanism 14F are driven in opposite directions by the hydraulic actuators 33 and 33, the power rollers 19 and 19 are tilted in the direction of arrow a in FIG. And the contact point with the output disk 16 moves radially inward with respect to the input shaft 13, so that the rotation of the input disk 15 increases. The transmission ratio of the toroidal-type continuously variable transmission T is continuously reduced. On the other hand, when the power rollers 19, 19 tilt in the direction of arrow b in FIG. 1, the contact point with the input disk 15 moves radially inward with respect to the input shaft 13, and the contact point with the output disk 16 becomes the input point. Since it moves radially outward with respect to the shaft 13, the rotation of the input disk 15 is decelerated and transmitted to the output disk 16, and the gear ratio of the toroidal continuously variable transmission T is continuously increased.

  The operation of the second continuously variable transmission mechanism 14R is the same as that of the first continuously variable transmission mechanism 14F described above, and the first and second continuously variable transmission mechanisms 14F and 14R perform a transmission operation in synchronization. Accordingly, the driving force input from the crankshaft 11 of the engine E to the input shaft 13 is steplessly shifted at an arbitrary speed ratio within the speed ratio range of the toroidal transmission mechanism T and output from the drive gear 22. .

  The hydraulic pressure adjusted in the hydraulic control circuit 42 is also supplied to the hydraulic loader 23 and used for slip suppression control of the power rollers 19.

  Next, based on FIG. 4, the configuration of the electronic control unit U for controlling the hydraulic pressure supplied to the hydraulic loader 23, that is, the clamping pressure for clamping the power roller 19 between the input disks 15 and 15 and the output disks 16 and 16, and The operation will be described.

  The electronic control unit U includes a reference clamping pressure setting means M1, a target input torque calculation means M2, a target transmission ratio calculation means M3, a required clamping pressure calculation means M4, an actual transmission ratio calculation means M5, and a volume change calculation. Means M6, volume change-clamping pressure conversion means M7, oil temperature correction means M8, and addition means M9 are provided.

  Based on the input torque currently input from the engine E to the toroidal continuously variable transmission T, the reference clamping pressure setting means M1 is provided between the input disks 15, 15 and the output disks 16, 16 and the power roller 19. Set the reference clamping pressure to prevent slippage. The conventional toroidal type continuously variable transmission T supplies the reference clamping pressure to the hydraulic loader 23 as it is to suppress the slip of the power roller 19. The input torque input to the toroidal type continuously variable transmission T is equal to the output torque of the engine E, and the output torque of the engine E can be calculated based on the intake negative pressure of the engine E and the engine speed.

  The target input torque calculation means M2 calculates the target input torque of the toroidal continuously variable transmission T based on the driver's request degree, for example, the opening degree of the accelerator pedal (accelerator pedal opening degree) operated by the driver. .

  The target gear ratio calculation means M3 calculates the target gear ratio of the toroidal type continuously variable transmission T based on the driver's request degree, for example, the opening degree of the accelerator pedal operated by the driver (accelerator pedal opening degree). .

  Based on the target input torque calculated by the target input torque calculation means M2 and the target speed ratio calculated by the target speed ratio calculation means M3, the required clamping pressure calculation means M4 is configured so that the toroidal continuously variable transmission T receives the target input. A required clamping pressure, which is a clamping pressure required when the torque and the target gear ratio are reached, is calculated.

  The actual gear ratio calculating means M5 calculates the actual gear ratio by dividing the rotation speed (input rotation speed) of the input shaft 13 of the toroidal type continuously variable transmission T by the rotation speed (output rotation speed) of the drive gear 22. .

  The volume change amount calculation means M6 calculates the volume change amounts of the first oil chamber 27 and the second oil chamber 28 of the hydraulic loader 23 based on the required clamping pressure. When hydraulic pressure acts on the first oil chamber 27 of the hydraulic loader 23, the cylinder 24 constituting the wall surface is elastically deformed by the hydraulic pressure, so that the volume of the first oil chamber 27 is expanded. Similarly, when the hydraulic pressure acts on the second oil chamber 28 of the hydraulic loader 23, the second piston 26 constituting the wall surface is elastically deformed by the hydraulic pressure, so that the volume of the second oil chamber 28 is expanded. FIG. 5 shows the relationship between the oil pressure and the volume of the first and second oil chambers 27 and 28, and it can be seen that the volume increases as the oil pressure increases at any gear ratio. Therefore, if the target gear ratio and the required clamping pressure are determined, it is possible to know the amount of increase in the volume of the first and second oil chambers 27 and 28 when the target gear ratio and the required clamping pressure are reached.

  As described above, when the volumes of the first and second oil chambers 27 and 28 increase, even if the hydraulic pressure corresponding to the reference clamping pressure is supplied, the clamping pressure decreases by the increase in volume, and the clamping pressure is insufficient. The power rollers 19, 19 may slip, but the slip of the power rollers 19, 19 is corrected by correcting the reference clamping pressure in the increasing direction in anticipation of an increase in the volume of the first and second oil chambers 27, 28. It is possible to generate a clamping pressure capable of preventing

  Further, the volume change amount calculation means M6 calculates a target shift speed based on the difference between the actual gear ratio and the target gear ratio, and synchronizes with the target shift speed to determine the volume of the first and second oil chambers 27, 28. Calculate the rate of increase.

  The volume change amount-clamping pressure conversion means M7 corrects the clamping pressure of the hydraulic loader 23 that can compensate for the volume change amount (volume change speed) of the first oil chamber 27 and the second oil chamber 28 of the hydraulic loader 23. Convert to quantity.

  The oil temperature correction means M8 corrects the correction amount of the clamping pressure of the hydraulic loader 23 based on the oil temperature of the toroidal type continuously variable transmission T. Specifically, since the oil viscosity is high at low temperatures and the pinching pressure is difficult to increase, the correction amount of the pinching pressure is corrected in the increasing direction. Conversely, at high temperatures, the oil viscosity is low and the pinching pressure tends to increase. The correction amount of the clamping pressure is corrected in the decreasing direction.

  The adding means M9 uses the volume change amounts of the first oil chamber 27 and the second oil chamber 28 calculated by the volume change amount calculating means M6 as the reference clamping pressure set by the reference clamping pressure setting means M1 as the correction amount of the clamping pressure. Convert and correct by adding the value corrected by the oil temperature. The hydraulic pressure control circuit 42 outputs the hydraulic pressure corresponding to the target clamping pressure to the hydraulic loader 23 so that the hydraulic loader 23 generates the final target clamping pressure output by the adding means M9.

  As a result, even if the volumes of the first oil chamber 27 and the second oil chamber 28 change due to the hydraulic pressure, the input discs 15 and 15 are corrected by correcting the reference clamping pressure by feedforward control so as to compensate for the volume change. In addition, it is possible not only to generate a pinching force for pinching the power roller 19 between the output disks 16 and 16 but also to reduce the driving force of the oil pump 41 while preventing the slippage of the power roller 19. This can contribute to improving the efficiency of the type continuously variable transmission T, reducing the amount of heat generated, and improving the durability. At this time, when the volumes of the first oil chamber 27 and the second oil chamber 28 increase, correction is made to increase the reference clamping pressure, and the volumes of the first oil chamber 27 and the second oil chamber 28 decrease. Since the correction is made to reduce the reference clamping pressure, an appropriate clamping pressure can be generated regardless of how the volume of the oil chamber changes.

  In addition, since the toroidal type continuously variable transmission T has a high speed change ratio, there is a possibility that the pinching pressure cannot follow the gear ratio even if the pinching pressure is feedback-controlled, but by feedforward control of the pinching pressure, Even in the toroidal type continuously variable transmission T in which the speed of change of the gear ratio is fast, it is possible to follow the clamping pressure without delaying the change of the gear ratio.

Second embodiment

  The first embodiment relates to the toroidal type continuously variable transmission T, while the second embodiment relates to the belt type continuously variable transmission T.

  As shown in FIG. 6, the belt type continuously variable transmission T for an automobile includes a drive shaft 111 and a driven shaft 112 arranged in parallel, and the left end of the crankshaft 113 of the engine E is driven via a damper 114. Connected to the right end of the shaft 111.

  A cylindrical outer shaft 140 is fitted to the outer periphery of the drive shaft 111 so as to be relatively rotatable, and a drive pulley 115 supported by the outer shaft 140 is a fixed pulley half formed integrally with the outer shaft 140. 141 and a movable pulley half 142 that is slidable in the axial direction with respect to the fixed pulley half 141. The groove width between the movable pulley half 142 and the fixed pulley half 141 is variable by the hydraulic pressure acting on the oil chamber 116. The driven pulley 117 supported by the driven shaft 112 includes a stationary pulley half 143 formed integrally with the driven shaft 112 and a movable pulley half slidable in the axial direction with respect to the stationary pulley half 143. A body 144. The groove width between the movable pulley half 144 and the fixed pulley half 143 is variable by the hydraulic pressure acting on the oil chamber 118. A metal belt 119 is wound around the drive pulley 115 and the driven pulley 117.

  A forward clutch 120 is engaged with the left end of the drive shaft 111 when the forward shift stage is established to transmit the rotation of the drive shaft 111 to the outer shaft 140 in the same direction, and is engaged when the reverse shift stage is established. A forward / reverse switching mechanism 122 comprising a single pinion planetary gear mechanism is provided, which includes a reverse brake 121 that transmits the rotation of the drive shaft 111 to the outer shaft 140 in the reverse direction. The sun gear 137 of the forward / reverse switching mechanism 122 is fixed to the drive shaft 111, the planetary carrier 138 can be restrained to the casing by the reverse brake 121, and the ring gear 139 can be coupled to the outer shaft 140 by the forward clutch 120.

  A starting clutch 123 provided at the right end of the driven shaft 112 couples the first intermediate gear 124 supported by the driven shaft 112 so as to be rotatable relative to the driven shaft 112. A second intermediate gear 126 that meshes with the first intermediate gear 124 is provided on an intermediate shaft 125 that is arranged in parallel with the driven shaft 112. The third intermediate gear 130 provided on the intermediate shaft 125 meshes with the input gear 129 provided on the gear box 128 of the differential gear 127. The pair of pinions 132 and 132 supported on the gear box 128 via the pinion shafts 131 and 131 are engaged with the side gears 135 and 136 provided at the front ends of the left axle 133 and the right axle 134 that are supported relatively rotatably on the gear box 128. To do. Drive wheels W and W are connected to the ends of the left axle 133 and the right axle 134, respectively.

  Therefore, when the forward range is selected by the select lever, the forward clutch 120 to which the oil pressure from the oil pump 41 is transmitted via the oil pressure control circuit 42 is engaged. As a result, the drive shaft 111 is driven via the outer shaft 140 to the drive pulley. 115 is integrally coupled. Subsequently, the starting clutch 123 is engaged, and the torque of the engine E passes through the drive shaft 111, the outer shaft 140, the drive pulley 115, the metal belt 119, the driven pulley 117, the driven shaft 112, and the differential gear 127 to drive wheels W, W. The vehicle starts moving forward. When the reverse range is selected with the select lever, the reverse brake 121 is engaged and the outer shaft 140 and the drive pulley 115 are driven in the direction opposite to the rotational direction of the drive shaft 111. Start backward.

  When the vehicle starts in this manner, the hydraulic pressure supplied to the oil chamber 116 of the drive pulley 115 by the hydraulic control circuit 42 increases, and the movable pulley half 142 of the drive pulley 115 approaches the fixed pulley half 141. As the effective radius increases, the hydraulic pressure supplied to the oil chamber 118 of the driven pulley 117 decreases, the movable pulley half 144 of the driven pulley 117 moves away from the fixed pulley half 143, and the effective radius decreases. Thus, the ratio of the belt type continuously variable transmission T continuously changes from the LOW side to the OD side.

  In such a belt type continuously variable transmission T, hydraulic pressure is supplied to the oil chamber 116 of the drive pulley 115 to urge the movable pulley half 142 against the fixed pulley half 141, and the driven pulley 117. By supplying hydraulic pressure to the oil chamber 118 and urging the movable pulley half 144 against the fixed pulley half 143, the metal belt 119 is prevented from slipping with respect to the drive pulley 115 and the driven pulley 117. Also in this case, the volume of the oil chamber 116 of the drive pulley 115 and the oil chamber 118 of the driven pulley 117 is increased by the hydraulic pressure. Therefore, even if the prescribed hydraulic pressure is applied, the increase in the volume of the oil chamber 118 is increased. There is a possibility that the clamping pressure is lowered and the metal belt 119 slips.

  However, according to the present embodiment, as in the first embodiment described above, the forward pressure control of the sandwiching pressure of the metal belt 119 in anticipation of an increase in the volume of the oil chambers 116 and 118 due to the hydraulic pressure, It is possible to reduce the driving force of the oil pump 41 while preventing the metal belt 119 from slipping by generating an excessive and insufficient clamping pressure, and improving the efficiency of the belt-type continuously variable transmission T, reducing the heat generation amount, and durability. It can contribute to improvement.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the toroidal-type continuously variable transmission T according to the embodiment includes the first oil chamber 27 and the second oil chamber 28, but may include only a single oil chamber.

  The toroidal transmission mechanism T of the embodiment is of a double cavity type, but may be of a single cavity type.

13 Input shaft 15 Input disc (clamping member)
16 Output disk (clamping member)
17 trunnion 19 power roller (power transmission member)
21 trunnion shaft 27 first oil chamber (oil chamber)
28 Second oil chamber (oil chamber)
33 Hydraulic actuator 115 Drive pulley (clamping member)
116 Oil chamber 117 Driven pulley (clamping member)
118 Oil Chamber 119 Metal Belt (Power Transmission Member)
M1 Reference clamping pressure setting means M2 Target input torque calculation means M3 Target transmission ratio calculation means M4 Required clamping pressure calculation means M5 Actual transmission ratio calculation means M6 Volume change amount calculation means M9 Addition means (clamping pressure correction means)
T Toroidal continuously variable transmission, belt type continuously variable transmission (continuously variable transmission)
U Electronic control unit (clamping pressure control means)

Claims (2)

The power transmission member (19, 119) is clamped between the pair of clamping members (15, 16, 115, 117) of the continuously variable transmission (T) with a predetermined clamping pressure, and the pair of clamping members (15, 16, 115, 117) and a control device for a continuously variable transmission that changes a gear ratio by changing a contact position of the power transmission member (19, 119),
A clamping pressure control means (U) for controlling the clamping pressure;
A reference for preventing slippage between the pair of clamping members (15, 16, 115, 117) and the power transmission member (19, 119) based on the actual input torque to the continuously variable transmission (T). Reference clamping pressure setting means (M1) for setting the clamping pressure;
Target input torque calculating means (M2) for calculating a target input torque to the continuously variable transmission (T) according to a driver's request level;
Target gear ratio calculating means (M3) for calculating a target gear ratio of the continuously variable transmission (T) in accordance with a driver's request level;
A required clamping pressure calculating means (M4) for calculating a required clamping pressure required when the target input torque and the target gear ratio are reached based on the target input torque and the target gear ratio; and the continuously variable transmission An actual speed ratio calculating means (M5) for calculating an actual speed ratio of the continuously variable transmission based on the input speed and the output speed of (T);
The request clamping pressure based on said target speed ratio and the actual speed ratio, the volume change amount calculating a volumetric change due to elastic deformation of the wall of the clamping pressure oil chamber to generate a (27,28,116,118) A calculation means (M6);
A clamping pressure correcting means (M9) for correcting the reference clamping pressure based on the volume change amount ;
The clamping pressure correction means (M9) corrects the reference clamping pressure to be increased when the volume of the oil chamber (27, 28, 116, 118) increases, and the oil chamber (27, 28, 116, 118) When the volume of 116,118) decreases, it correct | amends so that the said reference clamping pressure may be decreased , The control apparatus of the continuously variable transmission characterized by the above-mentioned . Before SL continuously variable transmission (T) includes an input disc said a press member which rotates with the input shaft (13) (15), said pressing members of said relatively rotatably supported on the input shaft (13) An output disk (16), a power roller (19) as the power transmission member sandwiched between the input disk (15) and the output disk (16), and the power roller (19) A trunnion (17) and a hydraulic actuator (33) for driving the trunnion (17) are provided. The hydraulic actuator (33) drives the trunnion (17) in the direction of the trunnion shaft (21), and the power roller ( 19) is swung around the trunnion shaft (21) to contact points of the input disk (15) and the output disk (16). And changes the speed ratio by changing the location, the control device for a continuously variable transmission according to claim 1.

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