JP2007198510A - Hydraulic pressure controller of toroidal type continuous transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic pressure controller of a toroidal type continuous transmission, which controller can easily and accurately control hydraulic pressure even when initial pressure varies. <P>SOLUTION: The hydraulic pressure controller of the toroidal type continuous transmission supplies working oil to an actuator by controlling the specified initial pressure according to a control command, wherein the controller comprises a command value setting means for setting the control command based on the difference between a target value and an actual value, and based on a predetermined reference initial pressure, and further comprises a correcting means (step S2 to S4) for correcting the control command determined by the command value setting means according to the degree of the change when the initial pressure has been changed from the reference initial pressure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toroidal-type continuously variable transmission that transmits torque between disks via a power roller sandwiched between an input disk and an output disk, and changes the gear ratio by tilting the power roller. In particular, the present invention relates to a toroidal-type continuously variable transmission that performs hydraulic pressure control for clamping a power roller and shift control for displacing the power roller.

  The toroidal type continuously variable transmission is configured so that a power roller is sandwiched between an input disk and an output disk, and torque is transmitted between the power roller and each disk via traction oil. . If the tangential speed of the power roller at the contact point (or contact area) between the power roller and each disk matches the tangential speed at the contact point radius of each disk, this is the neutral position. The force that tilts the power roller, that is, the tilting force does not occur. When the power roller is displaced (offset) from the neutral position, the tangential speed at the contact point between the power roller and each disk is different, so that a so-called side slip occurs, and the so-called tilt that tilts the power roller is caused. Power is generated.

  Therefore, the torque that can be transmitted by the toroidal-type continuously variable transmission is determined by the contact pressure between each disk and the power roller, that is, the clamping pressure with which each disk clamps the power roller. In the device described in Patent Document 1 in order to set the transmission torque capacity, the clamping pressure (contact force) is generated by a hydraulic pressing device, and when the torque to be transmitted changes, the pressing force by the pressing device is changed. The pressure is controlled to be a pressure corresponding to the torque.

  Moreover, in the apparatus of Patent Document 1, the control for offsetting the power roller from the neutral position and the control for returning to the neutral position are performed by electrically controlling the pressure oil supplied to and discharged from the hydraulic cylinder. Further, Patent Document 2 describes a toroidal continuously variable transmission configured to feedback control the hydraulic pressure supplied to and discharged from an actuator for offsetting a power roller. The device described in Patent Document 2 Therefore, the feedback gain is determined from a four-dimensional map of oil pressure, oil temperature, vehicle speed, and input shaft speed. Patent Document 3 describes a toroidal continuously variable transmission that sets a line pressure based on the higher one of the clutch required hydraulic pressure and the transmission hydraulic pressure.

JP 2003-194208 A JP-A-11-141670 JP 2001-99292 A

  Since the shift control in the toroidal-type continuously variable transmission is executed by tilting the power roller by displacing the power roller, it is necessary to accurately control the movement amount and position of the power roller. Therefore, in the device described in Patent Document 2, the gain used for feedback control of the so-called shift hydraulic pressure is based on a four-dimensional map using four parameters of oil pressure, oil temperature, gear ratio, and input rotation speed as parameters. I try to decide. For this reason, the amount of data to be obtained by experiments or the like increases, and the man-hours and labor required to create a map may increase. This is the same even when feedback control is performed on the clamping pressure described in Patent Document 1 described above.

  The present invention has been made paying attention to the above technical problem, and is a toroidal continuously variable transmission hydraulic control device capable of easily and accurately controlling pressure oil even when the original pressure changes. Is intended to provide.

  In order to achieve the above object, the invention of claim 1 is directed to a hydraulic control device for a toroidal continuously variable transmission that controls a predetermined source pressure in accordance with a control command value and supplies the actuator to the actuator. Command value setting means for setting the value based on the deviation between the target value and the actual value and a predetermined reference source pressure, and when the source pressure is changed from the reference source pressure, depending on the degree of change A hydraulic control apparatus comprising: a correction unit that corrects the control command value set by the command value setting unit.

  According to a second aspect of the present invention, in the first aspect of the invention, the toroidal continuously variable transmission includes a first actuator that generates a clamping pressure for sandwiching the power roller between the input disk and the output disk, and A second actuator that displaces the power roller from a neutral position, and the original pressure is set based on a higher hydraulic pressure of a hydraulic pressure required by the first actuator and a hydraulic pressure required by the second actuator. A hydraulic control device for a toroidal-type continuously variable transmission, characterized in that the line pressure is the same.

  According to a third aspect of the present invention, in the invention of the second aspect, the correction means includes a means for correcting a flow control command value of pressure oil supplied to and discharged from the second actuator. This is a hydraulic control device for a transmission.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the correction means includes means for correcting a gain for obtaining a flow rate control command value of the pressure oil supplied to or discharged from any of the actuators. This is a hydraulic control device for a toroidal type continuously variable transmission.

  According to the first aspect of the present invention, when the predetermined source pressure is controlled based on the control command value and supplied to the actuator, the control command value is a deviation between the target value to be achieved by the actuator and the actual value. It is set based on a predetermined reference source pressure. Therefore, since the source pressure that is a factor for determining the control command value is a fixed value, the variation factor in determining the control command value is reduced, and the control command value can be easily set. On the other hand, the flow rate or hydraulic pressure, which is a control value obtained as a result of control based on the control command value, is affected by the source pressure, but if the source pressure has been changed from the reference source pressure, the change is made. Since the control command value is corrected according to the degree, control according to the source pressure is finally possible.

  According to the invention of claim 2, a so-called clamping pressure for clamping the power roller and a so-called thrust for displacing (stroke) the power roller are respectively set by the oil pressure, and the original pressure is based on the higher one of the oil pressures. Is set as the line pressure. For this reason, there is no excess or deficiency in the source pressure, and the source pressure can be easily set.

  According to the third aspect of the present invention, the flow rate of the pressure oil supplied and discharged by the second actuator is controlled, and the control command value is corrected as described above. Therefore, the displacement amount (stroke amount) from the neutral position of the power roller ) Can be controlled accurately and without delay. Since the shift is executed by displacing the power roller, accurate shift control can be performed without causing a shift delay or a shift error.

  According to the invention of claim 4, since the gain used for the flow control of the pressure oil supplied to and discharged from any of the actuators is corrected as described above, the gain setting for performing the control in accordance with the original pressure is performed. Becomes easier.

  Next, the present invention will be described more specifically. The toroidal type continuously variable transmission targeted by the present invention has an input side disk and an output side disk facing each other, and a rotation center axis between these disks is a rotation center axis of each disk. Is a continuously variable transmission that is configured such that a power roller is disposed and sandwiched so as to be substantially orthogonal to the disk, and torque is transmitted between the disks via the power roller. In particular, it is a continuously variable transmission in which the opposing surface of each disk forms a toroidal surface, and the so-called half toroidal type in which the center of curvature of the opposing toroidal surface is near or outside the outer peripheral edge of each disk, Any of the types in which the center of curvature is inside the outer peripheral edge of each disk may be used. Further, the present invention is not limited to a so-called single cavity type continuously variable transmission including a pair of disks, and may be a double cavity type continuously variable transmission including two pairs of disks. The power rollers sandwiched between the input-side disk and the output-side disk need only be provided at equal intervals in the circumferential direction of the disk, and are not limited to a configuration including a pair of power rollers.

  Further, the toroidal type continuously variable transmission targeted by the present invention may be configured to generate a so-called clamping pressure for clamping the power roller by hydraulic pressure. Alternatively, the power roller may be displaced from the neutral position, and the operation of returning to the neutral position may be performed by hydraulic pressure. In this case, the pressure oil is directly feedback controlled without using a mechanical feedback mechanism.

  2 and 3 schematically show an example of a double-cavity half-toroidal continuously variable transmission, in which the input disk 1 and the output disk 2 with the toroidal surfaces facing each other are two pairs, the same shaft. It is arranged on the line. In the examples shown in these drawings, the input disks 1 are arranged at both the left and right ends in the axial direction, the output disks 2 are arranged in a so-called back-to-back manner, and an output member between these output disks 2 is used as an output member. An output gear 3 is arranged.

  The input shaft 4 passes through the center of each of the disks 1 and 2 and the output gear 3, and each input disk 1 is attached to the input shaft 4 so as to rotate integrally and move in the axial direction. Yes. On the other hand, the output disk 2 and the output gear 3 are rotatably fitted to the input shaft 4, and each output disk 2 and the output gear 3 are connected so as to rotate together. Yes. A lock nut 5 as a lock member for preventing the input disk 1 from coming off is attached to one end of the input shaft 4 (the left end in FIG. 2). A hydraulic cylinder 6 corresponding to the first actuator of the present invention is attached to the opposite end (the right end in FIG. 2). The hydraulic cylinder 6 is a clamping pressure generating mechanism for generating a clamping pressure that presses each pair of the input disk 1 and the output disk 2 toward each other, and the cylinder 7 is fixed to the input shaft 4. In addition, a piston 8 accommodated in the cylinder 7 so as to be movable in the axial direction is brought into contact with the back surface of the input disk 1. Accordingly, by supplying hydraulic pressure between the cylinder 7 and the piston 8, the piston 8 presses one input disk 1 toward the input disk 1 disposed on the opposite side. Has been.

  A plurality of power rollers 9 are sandwiched between each pair of input disk 1 and output disk 2. These power rollers 9 are so-called transmission members that mediate the transmission of torque between the input disk 1 and the output disk 2, have a substantially disk shape, and between the input disk 1 and the output disk 2, The disks 1 and 2 are arranged at equal intervals in the circumferential direction. Each power roller 9 is held by a trunnion 10 so as to rotate as the disks 1 and 2 rotate, and to tilt (tilt) between the disks 1 and 2.

  Each trunnion 10 is for holding the power roller 9 so as to rotate and tilt freely, and trunnion shafts 12 extend on both upper and lower sides of a holding portion 11 having a flat surface facing the center. Yes. The upper trunnion shaft 12 in FIG. 3 is fitted to the upper yoke 13 via a bearing, and the lower trunnion shaft 12 in FIG. 3 is fitted to the lower yoke 14 via a bearing. Accordingly, the trunnions 10 are connected to each other by the yokes 13 and 14 so as to be rotatable about the trunnion shaft 12. Therefore, the central axis of the trunnion shaft 12 is the tilt axis.

  Each power roller 9 is rotatably held by a pivot shaft 15 attached to the holding portion 11 in each trunnion 10, and a thrust bearing 16 is interposed between each power roller 9 and each trunnion 10. . The trunnion 10, the pivot shaft 15, the thrust bearing 16, and the like are so-called holding members.

  The lower trunnion shaft 12 in FIG. 3 in each trunnion 10 is connected to an actuator that performs a linear longitudinal operation. The actuator is composed of a fluid pressure cylinder, an electric cylinder that outputs torque by changing it into thrust, and a hydraulic cylinder 17 is employed in the example shown in the figure. The hydraulic cylinder 17 corresponds to the second actuator of the present invention. Specifically, the trunnion shaft 12 is connected to a piston 18 of a hydraulic cylinder 17 provided corresponding to each power roller 9. These hydraulic cylinders 17 are configured to move one power roller 9 upward in FIG. 3 and simultaneously move the other power roller 9 downward in FIG. 3. For example, the hydraulic chamber above the piston 18 in the left hydraulic cylinder 17 in FIG. 3 is a high oil chamber 17H for shifting to a high speed side with a small gear ratio, and the lower hydraulic chamber opposite to this is shifted. The low oil chamber 17L is used for shifting to a low speed side having a large ratio. In addition, the hydraulic chamber above the piston 18 in the right hydraulic cylinder 17 in FIG. 3 is a low oil chamber 17L for shifting to a low speed side with a large gear ratio, and the lower hydraulic chamber opposite to this is shifted. The high oil chamber 17H is used for shifting to a high speed side with a small ratio. The high oil chambers 17H and the low oil chambers 17L communicate with each other.

  The mechanism for shifting the power roller 9 from the neutral position to the upshift side or the downshift side will be described. The mechanism is configured to operate an actuator such as the hydraulic cylinder 17. In the example shown in the figure, the mechanism is constituted by a duty-controlled electromagnetic valve 19. In addition, this type of control valve may be provided with two valves, a valve for controlling supply / discharge of hydraulic pressure to the high-side oil chamber 17H and a valve for controlling supply / discharge of hydraulic pressure to the low-side oil chamber 17L, Or you may comprise so that supply and discharge of the hydraulic_pressure | hydraulic with respect to each oil chamber 17H and 17L may be controlled simultaneously with one control valve.

  The electromagnetic valve 19 shown in the figure includes a high side port 20 communicating with the high oil chamber 17H, a low side port 21 communicating with the low oil chamber 17L, an input port 22 to which line pressure is input, and two drains. Ports 23 and 24, and a spool 27 that is moved in the axial direction by a solenoid 25 and a spring 26 disposed on the opposite side thereof to switch the communication state of these ports. The spool 27 closes the input port 22 and the drain ports 23 and 24 with respect to both the high-side port 20 and the low-side port 21, and simultaneously connects the input port 22 to the high-side port 20. An upshift state in which the low-side port 21 communicates with the drain port 24, and a downshift state in which the low-side port 21 communicates with the input port 22 and the high-side port 20 communicates with the drain port 23. It is configured to switch to.

  The shift control using the electromagnetic valve 19 is electrically executed. That is, a stroke sensor 28 is provided to detect the position of each power roller 9 as the position or displacement of the trunnion 10. As an example, the stroke sensor 28 is attached to the trunnion shaft 12 of one trunnion 10, and is configured to electrically detect the amount of displacement in the axial direction and output it as a detection signal. Here, the amount of displacement is the amount of movement in the direction of the tilting axis from the neutral position where no side slip force or tilting force acts on the power roller 9.

  In addition, a tilt angle sensor 29 is provided on any trunnion shaft 12. In the example shown in the figure, a tilt angle sensor 29 is attached to another trunnion shaft 12 on the same axis as the trunnion shaft 12 to which the stroke sensor 28 is attached. The tilt angle sensor 29 electrically detects the rotation angle of the trunnion shaft 12 and outputs a signal. For example, the rotation speed of the input disk 1 and the output disk 2 is equal, that is, the gear ratio is “ The angle of the trunnion shaft 12 in the “1” state is set to “0”, the rotation angle of the trunnion shaft 12 from this state is detected as the tilt angle, and an electrical signal corresponding to the tilt angle is output. It has become.

  Further, an input rotational speed sensor 30 that detects the rotational speed of any one of the input disks 1 and outputs an electrical signal, and an output that detects the rotational speed of any one of the output disks 2 and outputs an electrical signal. A rotation speed sensor 31 is provided. Therefore, the actual gear ratio can be obtained based on the respective rotational speeds detected by these rotational speed sensors 30 and 31.

  Each of these sensors 28, 29, 30, 31 is electrically connected to an electronic control unit (ECU) 32 for controlling the transmission ratio and the aforementioned clamping pressure. The electronic control device 32 is mainly composed of a microcomputer, and performs various calculations according to an input signal, data stored in advance and a program, and outputs a control command signal based on the calculation result. It is configured to output. The toroidal-type continuously variable transmission can be mounted on a vehicle, and in this case, the electronic control unit 32 includes an accelerator opening in addition to the signals from the sensors 28, 29, 30, 31. Various detection signals such as vehicle speed, engine speed, etc. are input.

  A description will be given of torque transmission and shifting by the toroidal-type continuously variable transmission. When torque is input to the input disk 1 from a power source such as an engine, the torque is transmitted to the power roller 9 that is in contact with the input disk 1 via traction oil, and from the power roller 9 to the output disk 2. Torque is transmitted through the traction oil. In that case, the traction oil undergoes glass transition by being pressurized, and torque is transmitted by the accompanying large shearing force, so that each disk 1, 2 seems to generate a pressure corresponding to the input torque with the power roller 9. Pressed.

  Further, since the peripheral speed of the power roller 9 and the peripheral speed at the torque transmission point of each of the disks 1 and 2 (the point where the power roller 9 is in contact via the traction oil) are substantially the same, the power roller 9 Of each of the disks 1 and 2 according to the radius from the rotation center axis of the torque transmission point to the input disk 1 and the radius from the rotation center of the torque transmission point to the output disk 2. The rotational speed (rotational speed) is different, and the ratio of the rotational speed (rotational speed) is the gear ratio.

  The tilting of the power roller 9 that sets the gear ratio in this way is caused by moving the power roller 9 in the vertical direction in FIG. For example, when the solenoid valve 19 is controlled to supply pressure oil to the high oil chamber 17H of the hydraulic cylinder 17, the left power roller 9 in FIG. 3 moves downward and the right power roller 9 in FIG. Move up. As a result, a force (side slip force) that tilts each power roller 9 is generated between the disks 1 and 2, and each power roller 9 tilts. The amount of displacement of the power roller 9 is controlled based on the deviation between the actual tilt angle and the target tilt angle. Therefore, when the power roller 9 tilts gradually and matches the target tilt angle, the power roller 9 Is returned to its neutral position and its tilting stops. As a result, a target gear ratio is set.

  The electronic control device 32 obtains a tilt angle corresponding to a target gear ratio based on a required drive amount represented by a throttle opening or the like, a vehicle speed, and the like, and a solenoid valve so as to achieve the tilt angle. A command signal is output to 19. The target tilt angle can be achieved by causing the power roller 9 to stroke with the trunnion 10, so that the stroke amount of the power roller 9 is detected by the stroke sensor 28, and the deviation between the detected stroke amount and the stroke command amount is detected. A command signal (for example, duty ratio) for the electromagnetic valve 19 is feedback controlled as a control deviation.

  The above basic shift control is conceptually shown in a block diagram in FIG. In FIG. 5, first, a deviation between the target tilt angle φo corresponding to the target gear ratio and the actual tilt angle φ is obtained. The calculation of the target gear ratio and the tilt angle corresponding to the target gear ratio can be performed in the same way as conventionally performed in the shift control in the toroidal type continuously variable transmission. For example, the required driving force is calculated based on the required driving amount represented by the accelerator opening and the vehicle speed, and the target output is obtained from the required driving force and the vehicle speed, and the target output is achieved with the minimum fuel consumption. The rotational speed of the internal combustion engine is obtained, and the target gear ratio and the target tilt angle φo are obtained so that the input rotational speed of the continuously variable transmission becomes a rotational speed corresponding to the rotational speed of the internal combustion engine.

  The deviation is processed with a predetermined gain K1 to determine the stroke amount of the power roller 9 (for example, the stroke amount from the neutral point) X0. The deviation between the stroke amount X0 and the actual stroke amount X is processed by a predetermined gain K2, and a command signal (for example, duty ratio) is obtained for the solenoid valve 19, and the hydraulic pressure output by the solenoid valve 19 is obtained. When the power roller 9 is displaced and the power roller 9 is tilted accordingly, the continuously variable transmission (CVT) performs a speed change operation.

  The torque transmitted from the input disk 1 to the output disk 2 as described above is limited by the pressing force (indirect contact pressure) via the traction oil between the disks 1 and 2 and the power roller 9. . Therefore, in the toroidal-type continuously variable transmission described above, the thrust in the axial direction of the input shaft 4 is generated by the hydraulic cylinder 6 to control the clamping pressure for clamping the power roller 9 between each input disk 1 and output disk 2. ing. Further, when shifting, the power roller 9 is displaced by controlling the flow rate of the pressure oil supplied to and discharged from the hydraulic cylinder 17.

  The pressure oil supplied to and discharged from these hydraulic cylinders 6 and 17 is controlled using the line pressure as a source pressure, and an example of a hydraulic control circuit for that purpose is shown in a schematic block diagram in FIG. An oil pump 33 that is driven by an engine that is a driving force source and a motor (not shown) separately provided to generate hydraulic pressure is provided. A primary regulator valve 34 for adjusting the hydraulic pressure discharged from the oil pump 33 to the line pressure is connected to the discharge side of the oil pump 33. As the primary regulator valve 34, a line pressure regulating valve used in a conventional automatic transmission for a vehicle can be employed. For example, a control signal is provided at one end of a spool (not shown) as a valve body. The pressure is applied, the spring force and the feedback pressure are applied to the other end, and the hydraulic pressure that balances the control signal pressure, the spring force, and the feedback pressure appears as a line pressure at the output port. .

  The line pressure needs to be a sufficient hydraulic pressure to set a torque capacity capable of reliably transmitting the torque acting on the toroidal type continuously variable transmission, and is sufficient to generate a thrust force that displaces the power roller 9. It is necessary to use a proper hydraulic pressure. Therefore, in the above-described toroidal continuously variable transmission according to the present invention, based on the higher one of the hydraulic pressure required to set the required transmission torque capacity and the hydraulic pressure required for the shift control. Line pressure is set.

  The line pressure can be controlled by the control signal pressure described above, and an electromagnetic valve 35 for outputting the control signal pressure is provided. The electromagnetic valve 35 is a valve that outputs a hydraulic pressure corresponding to an electric signal such as a current or a duty ratio, and is controlled by the electronic control device 32. As a general tendency, the line pressure is controlled to increase as the output of a driving force source such as an engine increases.

  The line pressure is supplied to the hydraulic cylinder 6 through the clamping pressure control valve 36. The clamping pressure control valve 36 is a pressure regulating valve that regulates the line pressure to a target pressure and supplies the pressure to the hydraulic cylinder 6, and is configured such that the pressure regulation level is changed by the electronic control device 32, or The pressure regulation level is changed by a signal pressure output from an electromagnetic valve (not shown) controlled by the electronic control device 32.

  Further, the line pressure is supplied to the hydraulic cylinder 17 for shifting through the electromagnetic valve 19. That is, by controlling the flow rate of the pressure oil supplied to and discharged from the high oil chamber 17H and the low oil chamber 17L in the hydraulic cylinder 17 with the solenoid valve 19, the power roller 9 is offset from the neutral position and is returned to the neutral position. It is like that.

  When controlling the flow rate of the pressure oil, the flow rate varies depending on the pressure difference between the hydraulic pressure at the supply target location and the supplied hydraulic pressure, and the larger the pressure difference, the greater the flow rate. Therefore, when the solenoid valve 19 is duty-controlled and pressure oil is supplied and discharged, the hydraulic pressure that appears on the output side of the solenoid valve 19 differs depending on the line pressure that is the original pressure. This is schematically shown in FIG. In other words, the duty ratio at which the input hydraulic pressure appears on the output side is almost constant regardless of the input hydraulic pressure. Therefore, the output hydraulic pressure according to the duty ratio in the process of reaching the duty ratio is Varies depending on the side oil pressure (ie line pressure). In other words, if the control command value is constant, the amount of control such as the flow rate of hydraulic oil and the hydraulic pressure varies due to the change in the original pressure. On the other hand, the line pressure, which is the original pressure, varies depending on the required driving force expressed by the amount of depression of the accelerator pedal as described above.

  Therefore, in the hydraulic control apparatus according to the present invention, the relationship between the control command value (for example, duty ratio) and the controlled variable (for example, generated hydraulic pressure) is obtained for a predetermined line pressure reference value, and the actual line pressure is determined based on the line pressure reference value. When the value is different from the value, the control command value is corrected according to the change amount (change amount) of the line pressure. An example thereof will be described with reference to FIG. 6. The highest line pressure I that can be set is set as a line pressure reference value, and a control gain for shift control is set based on this. Therefore, the duty ratio, which is a control command value for obtaining the predetermined oil pressure P0, is “D1”. On the other hand, if the actual line pressure at the time of performing the shift control is a line pressure III lower than the line pressure reference value I, the duty ratio, which is a control command value for obtaining a predetermined oil pressure P0, is “D4”. In FIG. 6, the value of the inclined portion of the line indicating the line pressure I and the value of the inclined portion of the line indicating the line pressure III are in a fixed relationship such as a proportional relationship. A similar relationship is also established between the respective duty ratios D1 and D4. Therefore, by arithmetically correcting the duty ratio D1 obtained based on the line pressure reference value, a control command value corresponding to the actual line pressure is obtained. A certain duty ratio D4 can be obtained.

  The control gain can be determined in advance as a map according to the oil temperature, the input rotation speed, the gear ratio, etc., with the line pressure fixed at the above-described line pressure reference value, and based on the control gain. The duty ratio is obtained as described with reference to FIG.

  An example of the above-described line pressure setting and duty ratio correction and setting for shift control is shown in the flowchart of FIG. First, the line pressure is set (step S1). This is the higher pressure of the necessary clamping pressure calculated based on the required driving force represented by the accelerator opening and the necessary shifting pressure required to displace the power roller 9 for shifting. Based on. The line pressure is set by the so-called Max Select. The necessary transmission pressure can be calculated based on the input torque and the transmission ratio, or can be determined in advance as a map. The line pressure can be obtained by multiplying the high direction pressure by a predetermined coefficient. Next, the line pressure set in step S1 is compared with the above-described line pressure reference value (step S2). This is an operation for obtaining the ratio or difference between the two, and corresponds to an operation for obtaining the degree of change of the original pressure or the line pressure.

  On the other hand, the hydraulic pressure (that is, the standby pressure) of the hydraulic cylinder 17 in a state where the power roller 9 is maintained at the neutral position is compared with the transmission pressure required to execute the transmission (step S3). Specifically, an increase in hydraulic pressure for shifting or a duty ratio corresponding to the increase is obtained as a value based on the line pressure reference value. Accordingly, the duty ratio is, for example, “D1” shown in FIG.

  Then, the increase in hydraulic pressure or the corresponding duty ratio is corrected according to the degree of change in the original pressure or line pressure (step S4). Specifically, the correction is performed by multiplying the change rate of the line pressure obtained in step S2 by an increase in hydraulic pressure or a corresponding duty ratio for shifting.

  The oil pressure increase or duty ratio obtained in this way is, for example, “D4” shown in FIG. 6, which is added to the standby pressure or the corresponding duty ratio, and the corrected transmission oil pressure or the corresponding duty ratio. Is obtained (step S5).

  Therefore, by controlling the shift oil pressure as shown in FIG. 1, the shift in a state where the line pressure changes from the line pressure reference value is executed in the same manner as the shift at the line pressure reference value. That is, the occurrence of a slow speed in the supply and discharge of the pressure oil to and from the hydraulic cylinder 17 is suppressed, and an accurate shift can be achieved. Also, since the line pressure is used to correct the duty ratio, which is a control command value, when mapping the control gain or control command value for determining the shift hydraulic pressure, the line pressure may be removed from the map parameters. As a result, the man-hours and labor required to create a map for the control gain or control command value can be reduced.

  The example shown in FIG. 1 or FIG. 6 described above is an example of correcting the duty ratio. In the present invention, the control command value may be corrected according to the degree of change in the line pressure. Therefore, the control command value may be corrected as a result by correcting the control gain. Further, the control command value targeted in the present invention is not limited to the transmission hydraulic pressure, and may be a control command value for the hydraulic pressure for setting the clamping pressure.

  Here, the relationship between the specific example described above and the present invention will be briefly described. The functional means for executing the control shown in FIG. 4 corresponds to the command value setting means of the present invention, and steps S2 to S2 shown in FIG. The functional means of step S4 corresponds to the correcting means of this invention.

3 is a flowchart for explaining a control example of correction of shift hydraulic pressure executed by the hydraulic control apparatus according to the present invention. It is a figure which shows typically an example of the toroidal type continuously variable transmission made into object by this invention. It is typical sectional drawing which shows the state which cut | disconnected one cavity of the toroidal type continuously variable transmission by the plane which passes through the center part. It is a control block diagram for demonstrating an example of basic shift control by the transmission which concerns on this invention. It is a block diagram which shows typically a part of hydraulic circuit for controlling pinching pressure and transmission hydraulic pressure. It is a diagram which shows typically the relation between the duty ratio for every line pressure, and oil pressure.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Input disc, 2 ... Output disc, 3 ... Output gear, 4 ... Input shaft, 9 ... Power roller, 10 ... Trunnion, 12 ... Trunnion shaft, 17 ... Hydraulic cylinder, 19 ... Solenoid valve, 29 ... Tilt angle sensor , 30: input rotation speed sensor, 31: output rotation speed sensor, 32: electronic control unit (ECU), 33: oil pump, 34: primary regulator valve, 36: clamping pressure control valve.

Claims (4)

In a hydraulic control device for a toroidal continuously variable transmission that controls a predetermined source pressure according to a control command value and supplies the actuator to an actuator,
Command value setting means for setting the control command value based on a deviation between a target value and an actual value and a predetermined reference source pressure;
And a correction means for correcting the control command value set by the command value setting means according to the degree of change when the original pressure is changed from the reference original pressure. Hydraulic control device for toroidal type continuously variable transmission. The toroidal continuously variable transmission has a first actuator that generates a clamping pressure for clamping the power roller between the input disk and the output disk, and a second actuator that displaces the power roller from the neutral position. And
2. The line pressure set according to claim 1, wherein the original pressure is a line pressure set based on a high hydraulic pressure among a hydraulic pressure required by the first actuator and a hydraulic pressure required by the second actuator. Hydraulic control device for toroidal type continuously variable transmission.   The hydraulic control device for a toroidal continuously variable transmission according to claim 2, wherein the correction means includes means for correcting a flow rate control command value of pressure oil supplied to and discharged from the second actuator.   4. The toroidal type non-rotating device according to claim 1, wherein the correcting means includes means for correcting a gain for obtaining a flow control command value of pressure oil supplied to or discharged from any one of the actuators. Hydraulic control device for step transmission.

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