JP2014185716A - Continuously variable transmission and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuously variable transmission which can improve the fuel economy of an engine.SOLUTION: A continuously variable transmission 5 which has an annular band body 12 having a groove 12a engaged with movable teeth arranged at a second pulley 11, and energization means 41 for energizing the movable teeth 40 to the radial outside of a shaft part 13 comprises: engagement determination means 20 which determines whether or not the groove 12a of the band body 12 is engaged with the movable teeth 40; and oil pressure control means 20 which lowers the oil pressure of a second oil chamber 11c when it is determined that the groove 12a of the band body 12 is engaged with the movable teeth 40.

Description

  The present invention relates to a continuously variable transmission.

  Conventionally, movable teeth urged radially outward by a spring are provided on the shaft portion of the pulley, a meshing groove is provided on the endless chain link, and the meshing groove is made movable when the gear ratio is, for example, the highest gear ratio. Patent Document 1 discloses a continuously variable transmission that meshes.

JP 2010-014269 A

  In the above continuously variable transmission, when a part of the endless chain link comes into contact with the movable tooth, the movable tooth is pushed radially inward by the endless chain link, and a biasing force radially outward by the spring is generated. If the gear ratio is to be further changed to the highest side, this biasing force must be resisted, so that there arises a problem that gear shifting becomes difficult.

  The present invention has been invented in order to solve such problems, and has an object to smooth the speed change after the meshing groove of the endless chain link comes into contact with the movable tooth.

  A continuously variable transmission according to an aspect of the present invention includes a first pulley having a first fixed conical plate and a first movable conical plate that moves in an axial direction in accordance with hydraulic pressure supplied to and discharged from the first oil chamber, 2 fixed conical plates, a second movable conical plate that moves in the axial direction according to the hydraulic pressure supplied to and discharged from the second oil chamber, a second pulley having movable teeth that can move in the radial direction of the shaft portion, and a first pulley An annular belt member that is wound between the first pulley and the second pulley, transmits power between the first pulley and the second pulley, and has a groove that engages with the movable teeth on the inner peripheral surface, and is movable. A continuously variable transmission comprising: an urging means for urging teeth radially outward of the shaft portion; and an oil pump that is driven by a power source and supplies hydraulic pressure to the first oil chamber and the second oil chamber, Engagement determining means for determining whether the groove of the belt is engaged with the movable tooth, and the groove of the belt is engaged with the movable tooth by the engagement determining means. If it is determined that, and a hydraulic pressure control means for reducing the pressure in the second oil chamber.

  The control method according to another aspect of the present invention includes a first pulley having a first movable conical plate and a first movable conical plate that moves in an axial direction in accordance with hydraulic pressure supplied to and discharged from the first oil chamber, and a second pulley. A second pulley having a fixed conical plate, a second movable conical plate that moves in the axial direction according to the hydraulic pressure supplied to and discharged from the second oil chamber, a movable tooth that is movable in the radial direction of the shaft portion, and a first pulley; An annular belt member that is wound between the second pulley and transmits power between the first pulley and the second pulley and meshes with the movable tooth, and has a groove formed on the inner peripheral surface, and the movable tooth Method for controlling a continuously variable transmission comprising: an urging means for urging the shaft portion radially outward of the shaft portion; and an oil pump driven by a power source and supplying hydraulic pressure to the first oil chamber and the second oil chamber. Then, it was determined whether the belt groove engaged with the movable teeth, and it was determined that the belt groove engaged with the movable teeth. The case, reducing the hydraulic pressure of the second oil chamber.

  According to these aspects, when it is determined that the groove of the belt body is meshed with the movable tooth, the radial outward force that the belt body receives from the second pulley is reduced by reducing the hydraulic pressure of the second oil chamber. Becomes smaller. For this reason, for example, when shifting the gear ratio to the highest side, the belt member comes into contact with the movable tooth, the movable tooth is pushed radially inward by the belt member, and a biasing force to the radially outer side by the spring is generated. However, it is easy to further change the gear ratio to the highest side by the amount of the radial outward force received by the belt from the second pulley. Thereby, when changing a gear ratio further to the highest side after a belt | band | zone contact | connects a movable tooth, it can suppress that it becomes difficult to carry out a gear shift.

It is a schematic block diagram of the continuously variable transmission of this embodiment. It is the schematic of the secondary pulley which removed the chain. It is a schematic perspective view of the output shaft part of a secondary pulley. It is the schematic sectional drawing which cut | disconnected the secondary pulley along the axial direction of an output shaft. It is a figure which shows the state which a movable cone plate moves in FIG. 4 to the movable cone plate side. It is a schematic block diagram of a spring. It is a conceptual diagram of the hydraulic control unit and CVT control unit of an embodiment. It is a flowchart explaining the shift control of this embodiment. It is a flowchart explaining the shift control of this embodiment. It is a flowchart explaining the shift control of this embodiment. It is a map which shows the relationship between a target gear ratio and a step motor position. It is a map which shows the relationship between target line pressure and a line pressure solenoid command value. It is a map which shows the relationship between a target primary pulley pressure and a primary pulley pressure solenoid command value. It is a map which shows the relationship between a deviation and the secondary pulley pressure reduction amount. It is a map which shows the relationship between a target secondary pulley pressure and a secondary pulley pressure solenoid command value.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the “speed ratio” is a value obtained by dividing the input rotational speed of a chain type continuously variable transmission (hereinafter referred to as a continuously variable transmission) by the output rotational speed. The continuously variable transmission becomes higher as the gear ratio is smaller. FIG. 1 is a schematic configuration diagram of a continuously variable transmission.

  The continuously variable transmission 5 is connected to the engine 1 via a torque converter 2 having a lock-up clutch and a forward / reverse switching mechanism 4. The continuously variable transmission 5 includes a primary pulley 10 to which driving force is transmitted from the engine 1, a secondary pulley 11 connected to the output shaft 13, and an endless chain link that is wound around the primary pulley 10 and the secondary pulley 11. (Hereinafter referred to as a chain) 12. The output shaft 13 is connected to the differential 6 via an idler gear 14.

  The chain 12 is a band formed by connecting a large number of links with link pins to form an annular shape. As shown in FIG. 4, a meshing groove 12 a that can mesh with a tooth portion 53 of a movable tooth 40 described later is formed on the inner peripheral surface of the chain 12. The meshing refers to a state in which the meshing groove 12 a and the tooth portion 53 overlap in the radial direction of the output shaft 13 and power is transmitted between the meshing groove 12 a and the tooth portion 53. Since the meshing groove 12 a meshes with the movable tooth 40, it is possible to suppress the occurrence of slip between the chain 12 and the secondary pulley 11.

  The primary pulley 10 includes a fixed conical plate 10b that rotates integrally with the input shaft, and a movable conical plate 10a that is disposed to face the fixed conical plate 10b and forms a V-shaped pulley groove. The movable conical plate 10a is displaced in the axial direction of the input shaft when primary pulley pressure is supplied to and discharged from the primary pulley cylinder chamber 10c.

  The secondary pulley 11 includes a fixed conical plate 11 b that rotates integrally with the output shaft 13, a movable conical plate 11 a that is disposed opposite to the fixed conical plate 11 b to form a V-shaped pulley groove, and a shaft of the output shaft 13. A movable tooth 40 formed along the direction and a spring 41 that urges the movable tooth 40 outward in the radial direction of the output shaft 13 are provided. The secondary pulley 11 will be described in detail with reference to FIGS. FIG. 2 is a schematic view of the secondary pulley 11 with the chain 12 removed. FIG. 3 is a schematic perspective view of the output shaft 13 portion of the secondary pulley 11. FIG. 4 is a schematic cross-sectional view of the secondary pulley 11 cut along the axial direction of the output shaft 13.

  The movable tooth 40 is movable in the radial direction of the output shaft 13 in each of a plurality of movable tooth guide grooves 42 provided on the outer peripheral surface of the output shaft 13 at equal intervals in the circumferential direction and along the axial direction. It is provided as follows. The movable tooth 40 rotates integrally with the output shaft 13.

  The movable tooth 40 includes a base 50 extending in the axial direction of the output shaft 13, a first stopper 51 projecting radially outward from the end of the base 50 on the fixed conical plate 11 b side, and a movable cone in the base 50. A second stopper 52 projecting radially outward of the output shaft 13 from the end on the plate 11a side, and a tooth projecting radially outward of the output shaft 13 from the base 50 between the first stopper 51 and the second stopper 52 Part 53.

  The movable tooth 40 is pushed outward in the radial direction of the output shaft 13 by a spring 41 provided between the base 50 and the output shaft 13. The movable tooth 40 moves in the radial direction of the output shaft 13 according to the elastic force of the spring 41 and the pressing force generated when the meshing groove 12 a of the chain 12 meshes with the movable tooth 40. When there is no pressing force or when the elastic force is larger than the pressing force, the first stopper 51 contacts the inner peripheral surface 11d of the fixed conical plate 11b, and the second stopper 52 is the inner peripheral surface of the movable conical plate 11a. 11e. In this way, the first stopper 51 contacts the inner peripheral surface 11d of the fixed conical plate 11b, and the second stopper 52 contacts the inner peripheral surface 11e of the movable conical plate 11a. Movement to the outside in the radial direction is restricted. When the pressing force is larger than the elastic force, the movable tooth 40 moves to the output shaft 13 side and is held at a position where the elastic force and the pressing force are balanced.

  The tooth portion 53 is formed along the axial direction of the output shaft 13 and is formed according to the shape of the meshing groove 12 a of the chain 12. The tooth tip of the tooth portion 53 is formed so as not to protrude outward in the radial direction of the output shaft 13 from the inner peripheral surfaces 11d and 11e. Therefore, the movable conical plate 11a can move in the axial direction of the output shaft 13 without interfering with the tooth portion 53, as shown in FIG. FIG. 5 is a diagram illustrating a state in which the movable conical plate 11a moves to the fixed conical plate 11b side in FIG.

  As shown in FIG. 6, the spring 41 is configured by arranging linear U-shaped elements 60 and linear connecting elements 61 alternately on the same circumference. FIG. 6 is a schematic configuration diagram of the spring 41. In the present embodiment, as shown in FIG. 4, the three springs 41 are arranged in the axial direction of the output shaft 13.

  The connecting element 61 engages with a groove 13a provided in the circumferential direction of the output shaft 13, and movement of the output shaft 13 inward in the radial direction is restricted by a groove bottom 13b.

  The U-shaped element 60 is provided such that a U-shaped bottom portion 60 a is positioned on the radially outer side of the output shaft 13 with respect to the connecting element 61, and the bottom portion 60 a abuts on the movable tooth 40. The elastic force of the spring 41 increases as the movable tooth 40 is pushed radially inward of the output shaft 13. The U-shaped elements 60 are provided in the same number as the movable teeth 40, and the elastic force that each movable tooth 40 receives from the U-shaped elements 60 varies depending on the contact state between each movable tooth 40 and the chain 12.

  The movable conical plate 11a is displaced in the axial direction of the output shaft 13 when the secondary pulley pressure is supplied to and discharged from the secondary pulley cylinder chamber 11c.

  The continuously variable transmission 5 changes speed by changing the balance between the primary pulley pressure and the secondary pulley pressure.

  The transmission ratio of the continuously variable transmission 5 and the thrust of the pulleys 10 and 11 are controlled by a hydraulic control unit 100 that responds to a command from the CVT control unit 20. The CVT control unit 20 determines and controls the target gear ratio and thrust based on engine output torque information output from the engine control unit 21 that controls the engine 1 and signals output from sensors and the like described later.

  The driving torque generated in the engine 1 is input to the primary pulley 10 of the continuously variable transmission 5 via the torque converter 2 and the forward / reverse switching mechanism 4 and is transmitted from the primary pulley 10 to the secondary pulley 11 via the chain 12. . By moving the movable conical plate 10a of the primary pulley 10 and the movable conical plate 11a of the secondary pulley 11 in the axial direction, the primary pulley 10 and the chain 12 and the contact radius between the secondary pulley 11 and the chain 12 are changed. And the gear ratio in the secondary pulley 11 is continuously changed.

  As shown in FIG. 7, the hydraulic control unit 100 includes a regulator valve 32, a shift control valve 37, a pressure reducing valve 30, and a pressure reducing valve 34. FIG. 7 is a conceptual diagram of the hydraulic control unit 100 and the CVT control unit 20.

  The regulator valve 32 includes a solenoid 33 that regulates the pressure of oil discharged from an oil pump 36 that is driven by transmission of part of the driving torque generated in the engine 1. The regulator valve 32 adjusts the pressure of the oil discharged from the oil pump 36 to a predetermined line pressure corresponding to the operating state in accordance with a command (for example, a duty signal) from the CVT control unit 20.

  The pressure reducing valve 30 includes a solenoid 31 that regulates the line pressure. The pressure reducing valve 30 adjusts the line pressure to a predetermined primary pulley pressure in accordance with a command (for example, a duty signal) from the CVT control unit 20. The primary pulley pressure is supplied to and discharged from the primary pulley cylinder chamber 10c.

  The pressure reducing valve 34 includes a solenoid 35 that regulates the line pressure. The pressure reducing valve 34 adjusts the line pressure to a predetermined secondary pulley pressure in accordance with a command (for example, a duty signal) from the CVT control unit 20. The secondary pulley pressure is supplied to and discharged from the secondary pulley cylinder chamber 11c.

  The shift control valve 37 is a control valve that controls the primary pulley pressure in the primary pulley cylinder chamber 10c to be a desired target pressure. The shift control valve 37 is connected to a servo link 70 constituting a mechanical feedback mechanism, is driven by a step motor 71 connected to one end of the servo link 70, and is connected to the other end of the servo link 70. The groove width, that is, feedback of the actual gear ratio is received from the movable conical plate 10a. The speed change control valve 37 adjusts the primary pulley pressure so as to achieve the target speed ratio commanded at the drive position of the step motor 71 by sucking and discharging the hydraulic pressure to the primary pulley cylinder chamber 10c by the displacement of the spool 37a. When the shift is completed, the spool 37a is held in the valve closing position in response to the displacement from the servo link 70.

  The CVT control unit 20 includes a signal from the inhibitor switch 22, a signal from the accelerator pedal sensor 23, a signal from the primary pulley rotational speed sensor 24, a signal from the secondary pulley rotational speed sensor 25, a signal from the brake pedal sensor 26, a primary Based on the signal from the pulley pressure sensor 27, the signal from the secondary pulley pressure sensor 28, the signal from the engine control unit 21, etc., the gear ratio and the like are controlled. The engine control unit 21 sends information such as engine rotation speed and engine output torque based on a signal from the engine rotation speed sensor 29.

  In the continuously variable transmission 5, when changing the gear ratio to High side, for example, the highest level, a part of the meshing groove 12 a of the chain 12 starts to mesh with the movable teeth 40 before the gear ratio becomes the highest level. A part of the movable teeth 40 is pushed inward in the radial direction of the output shaft 13 by the chain 12. Even when a part of the meshing groove 12 a of the chain 12 meshes with the movable tooth 40, the other part of the meshing groove 12 a of the chain 12 does not mesh with the movable tooth 40, and the chain 12 moves to the movable tooth 40. Is pushed inward in the radial direction of the output shaft 13. Therefore, after the gear ratio becomes the gear ratio at which the meshing groove 12a of the chain 12 starts to mesh with the movable teeth 40, the elastic force by the spring 41 acts on the chain 12, and the elastic force by the spring 41 is taken into consideration. You have to change the speed.

  The speed change control of the present embodiment facilitates the change to the speed change ratio at which the meshing groove 12a of the chain 12 meshes with the movable teeth 40 by adjusting the secondary pulley pressure in the above situation.

  Next, the shift control in this embodiment will be described with reference to the flowcharts of FIGS.

  In step S100, the CVT control unit 20 determines whether or not a failure determination flag described later in detail is “1”. The process proceeds to step S138 when the failure determination flag is “1”, and proceeds to step S101 when the failure determination flag is “0”.

  In step S101, the CVT control unit 20 calculates the target gear ratio from the vehicle speed, the engine speed, the throttle opening, and the position of the select lever. The vehicle speed is detected based on a signal from a wheel speed sensor (not shown). As for the engine speed, a signal from the engine speed sensor 29 is transmitted to the engine control unit 21 and is transmitted from the engine control unit 21 to the CVT control unit 20 as information. The throttle opening is detected based on a signal from the accelerator pedal sensor 23. The position of the selector lever is detected based on a signal from the inhibitor switch 22.

  In step S102, the CVT control unit 20 calculates the step motor position from the map shown in FIG. 11 based on the target gear ratio.

  In step S103, the CVT control unit 20 drives the step motor 71 based on the calculated step motor position. Thereby, the shift control valve 37 is controlled.

  In step S <b> 104, the CVT control unit 20 receives input torque information from the control unit 21.

  In step S105, the CVT control unit 20 calculates a minimum thrust limit value, a basic primary pulley thrust, and a basic secondary pulley thrust based on the target gear ratio and the input torque.

  In step S106, the CVT control unit 20 calculates a target line pressure based on the basic primary pulley thrust and the basic secondary pulley thrust.

  In step S107, the CVT control unit 20 calculates a line pressure solenoid command value from the map shown in FIG. 12 based on the target line pressure.

  In step S108, the CVT control unit 20 controls the solenoid 33 of the regulator valve 32 based on the line pressure solenoid command value to adjust the line pressure.

  In step S109, the CVT control unit 20 calculates the target primary pulley pressure and the target secondary pulley pressure by thrust distribution control based on the basic secondary pulley thrust and the minimum thrust limit value.

  In step S110, the CVT control unit 20 calculates a primary pulley pressure solenoid command value from the map shown in FIG. 13 based on the target primary pulley pressure.

  In step S111, the CVT control unit 20 controls the solenoid 31 of the pressure reducing valve 30 based on the primary pulley pressure solenoid command value, and adjusts the primary pulley pressure supplied to the speed change control valve 37.

  In step S112, the CVT control unit 20 detects the actual primary pulley pressure based on the signal from the primary pulley pressure sensor 27.

  In step S113, the CVT control unit 20 determines whether the actual primary pulley pressure and the target primary pulley pressure are equal. The process proceeds to step S123 when the actual primary pulley pressure and the target primary pulley pressure are equal, and proceeds to step S114 when the actual primary pulley pressure and the target primary pulley pressure are not equal.

  In step S114, the CVT control unit 20 determines whether the actual primary pulley pressure is lower than the target primary pulley pressure. The process proceeds to step S115 when the actual primary pulley pressure is higher than the target primary pulley pressure, and proceeds to step S123 when the actual primary pulley pressure is lower than the target primary pulley pressure.

  In step S115, the CVT control unit 20 detects the primary pulley rotation speed based on the signal from the primary pulley rotation speed sensor 24.

  In step S116, the CVT control unit 20 detects the secondary pulley rotational speed based on the signal from the secondary pulley rotational speed sensor 25.

  In step S117, the CVT control unit 20 calculates the actual gear ratio by dividing the primary pulley rotational speed by the secondary pulley rotational speed (step S117 constitutes a gear ratio calculating means).

  In step S118, the CVT control unit 20 determines whether or not the actual gear ratio is equal to or less than a predetermined gear ratio. The predetermined gear ratio is a gear ratio at which it can be determined that the meshing groove 12a of the chain 12 meshes with the movable tooth 40 and the actual primary pulley pressure is equal to or higher than the predetermined pressure. The predetermined pressure is a pressure at which the chain 12 can be determined to be urged radially outward of the output shaft 13 by the elastic force of the spring 41. The predetermined pressure is set in consideration of an error of a sensor or the like, and as the input torque increases. growing. The predetermined pressure is a pressure that is 110% higher than the target primary pulley pressure. The process proceeds to step S119 when the actual speed ratio is equal to or less than the predetermined speed ratio, and proceeds to step S123 when the actual speed ratio is greater than the predetermined speed ratio.

  In step S119, the CVT control unit 20 determines whether or not the actual primary pulley pressure is equal to or higher than a predetermined pressure (step S119 constitutes a meshing determination unit). The predetermined pressure is the same value as the predetermined pressure in step S118. Here, it is determined whether the actual primary pulley pressure is actually equal to or higher than a predetermined pressure. If there is no abnormality in any of the movable teeth 40, the spring 41, and the chain 12, the urging force of the movable teeth 40 acts on the chain 12, and the actual primary pulley pressure increases accordingly and becomes a predetermined value or more. ing. The process proceeds to step S120 when the actual primary pulley pressure is equal to or higher than the predetermined pressure, and proceeds to step S121 when the actual primary pulley pressure is lower than the predetermined pressure.

  In step S120, the CVT control unit 20 sets the secondary pulley reduction instruction flag to “1”. The secondary pulley reduction instruction flag is set to “0” as an initial value.

  In step S121, the CVT control unit 20 determines whether or not the secondary pulley reduction instruction flag is “1”. The process proceeds to step S124 when the secondary pulley reduction instruction flag is “1”, and proceeds to step S122 when the secondary pulley reduction instruction flag is “0”.

  In step S122, the CVT control unit 20 sets the failure determination flag to “1”. The failure determination flag is set to “0” as an initial value.

  In step S123, the CVT control unit 20 determines whether or not the secondary pulley reduction instruction flag is “1”. The process proceeds to step S124 if the secondary pulley reduction instruction flag is “1”, and proceeds to step S136 if the secondary pulley reduction instruction flag is “0”.

  In step S124, the CVT control unit 20 determines whether or not a secondary pulley pressure reduction learning flag for an estimated input torque, which will be described in detail later, is “1”. The process proceeds to step S125 when the secondary pulley pressure reduction learning flag is “1”, and proceeds to step S126 when the secondary pulley pressure reduction learning flag is “0”.

  In step S125, the CVT control unit 20 sets a learning value, which will be described later in detail, as a target secondary pulley pressure based on the actual gear ratio. Here, the current target secondary pulley pressure is overwritten by the learned value.

  In step S126, the CVT control unit 20 calculates the deviation between the actual primary pulley pressure and the target primary pulley pressure.

  In step S127, the CVT control unit 20 calculates the secondary pulley pressure reduction amount from the map shown in FIG. 14 based on the deviation. The amount of secondary pulley pressure reduction increases as the deviation increases. The secondary pulley pressure reduction amount is calculated so as to reduce the tension of the chain 12 that increases on the secondary pulley 11 side by the elastic force of the spring 41. Thereby, even when the meshing groove 12a of the chain 12 meshes with the movable tooth 40, it becomes possible to perform a shift without increasing the primary pulley pressure.

  In step S128, the CVT control unit 20 subtracts the secondary pulley pressure reduction amount from the target secondary pulley pressure to calculate a post-reduction secondary pulley pressure.

  In step S129, the CVT control unit 20 calculates the minimum secondary pulley pressure based on the basic secondary pulley thrust and the minimum thrust limit value.

  In step S130, the CVT control unit 20 determines whether the post-reduction secondary pulley pressure is equal to or greater than the minimum secondary pulley pressure. The process proceeds to step S131 when the post-reduction secondary pulley pressure is greater than or equal to the minimum secondary pulley pressure, and proceeds to step S132 when the post-reduction secondary pulley pressure is lower than the minimum secondary pulley pressure.

  In step S131, the CVT control unit 20 sets the post-reduction secondary pulley pressure as the target secondary pulley pressure. Here, the current target secondary pulley pressure is overwritten by the post-reduction secondary pulley pressure.

  In step S132, the CVT control unit 20 sets the minimum secondary pulley pressure command value as the target secondary pulley pressure. Here, the current target secondary pulley pressure is overwritten by the minimum secondary pulley pressure command value.

  The target secondary pulley pressure overwritten in step S131 and step S132 is temporarily stored in CVT control unit 20 in accordance with each actual gear ratio.

  In step S133, the CVT control unit 20 determines whether or not the actual gear ratio has reached the highest level. The process proceeds to step S134 when the actual gear ratio is the highest, and proceeds to step S136 when the actual gear ratio is not the highest.

  In step S134, the CVT control unit 20 memorize | stores the target secondary pulley pressure memorize | stored with respect to an actual gear ratio as a learning value (step S134 comprises a learning means). Note that the temporarily stored target secondary pulley pressure is deleted. Further, the target secondary pulley pressure that is temporarily stored is also deleted when the actual gear ratio is changed from the previous control to the low gear ratio.

  In step S135, the CVT control unit 20 sets the secondary pulley pressure learning flag to “1”. The secondary pulley pressure learning flag is set to “0” as an initial value. The secondary pulley pressure learning flag is set for each input torque.

  In step S136, the CVT control unit 20 calculates a secondary pulley pressure solenoid command value from the map shown in FIG. 15 based on the target secondary pulley pressure.

  In step S137, the CVT control unit 20 controls the solenoid 35 of the pressure reducing valve 34 based on the secondary pulley pressure solenoid command value, and regulates the secondary pulley pressure (step S137 constitutes a hydraulic pressure control means).

  If it is determined in step S100 that the failure determination flag is “1”, in step S138, the CVT control unit 20 determines that the other abnormality determination flag, for example, the gear ratio is the meshing groove 12a of the chain 12 and the movable teeth 40. It is determined whether or not an abnormality has occurred in the continuously variable transmission 5 based on a flag indicating that slip has occurred at a transmission gear ratio lower than the first transmission gear ratio (step S138 is an abnormality determination means). Configure.). The process proceeds to step S139 if another abnormality has occurred in the continuously variable transmission 5, and proceeds to step S140 if no other abnormality has occurred in the continuously variable transmission 5.

  In step S139, the CVT control unit 20 executes the safe mode. In the safe mode, for example, when the vehicle is traveling, the gear ratio is maintained at the current gear ratio, and after the vehicle stops, the gear ratio is limited to the lowest level.

  In step S140, the CVT control unit 20 limits the gear ratio so that the meshing groove 12a of the chain 12 and the movable tooth 40 do not mesh (step S140 constitutes a limiting means). Further, the CVT control unit 20 may notify the driver by turning on a warning lamp indicating that any one of the movable teeth 40, the spring 41, and the chain 12 is abnormal (step S140). Constitutes notification means.)

  The effect of the embodiment of the present invention will be described.

  When the gear ratio is changed to a gear ratio at which the meshing groove 12a of the chain 12 meshes with the movable teeth 40, the secondary pulley pressure is reduced when the meshing groove 12a of the chain 12 meshes with the movable teeth 40. Thereby, when changing a gear ratio to the highest, for example, a speed change can be performed smoothly (effect corresponding to Claims 1 and 11). Further, if the gear ratio is changed to the High side against the force that the movable tooth 40 tries to push the chain 12 back to the Low side without lowering the secondary pulley pressure, further differential thrust is obtained. Therefore, the primary pulley pressure must be increased, but since the secondary pulley pressure is reduced, the increase in the primary pulley pressure is suppressed, and the primary pulley pressure is lowered even after the gear ratio is changed to the highest level. The fuel consumption of the engine 1 that operates the oil pump 36 can be improved. In addition, the oil pump 36 can be reduced in size by suppressing the increase in the primary pulley pressure, and the fuel consumption of the engine 1 can also be improved. In other words, if the increase in the primary pulley pressure cannot be suppressed, the hydraulic pressure required for gear shifting increases correspondingly, and the oil pump 36 increases in size accordingly. As a result, the energy for driving the engine also increases, resulting in deterioration of fuel consumption.

  When the gear ratio is a predetermined gear ratio at which the meshing groove 12a of the chain 12 meshes with the movable tooth 40, and when the primary pulley pressure reaches a predetermined pressure, it is determined that the meshing groove 12a of the chain 12 is meshed with the movable tooth 40; Reduce secondary pulley pressure. When the meshing groove 12a of the chain 12 and the movable tooth 40 mesh with each other, the gear must be shifted against the elastic force of the spring 41, and the primary pulley pressure increases according to the elastic force. In this embodiment, by determining that the meshing groove 12a of the chain 12 and the movable tooth 40 are meshed based on the primary pulley pressure, the meshing state of the meshing groove 12a of the chain 12 and the movable tooth 40 is accurately determined. (Effect corresponding to claim 2).

  As the primary pulley pressure increases, the secondary pulley pressure reduction amount is increased. Thereby, the secondary pulley pressure can be reduced according to the elastic force of the spring 41. The magnitude of the elastic force of the spring 41 has a correlation with the meshing state of the meshing groove 12a and the movable tooth 40. For this reason, if the secondary pulley pressure is reduced in accordance with the elastic force of the spring 41, the shortage of the secondary pulley 11 due to excessive reduction of the secondary pulley pressure can be suppressed, and the secondary pulley pressure can be reduced. Therefore, it is possible to suppress the occurrence of slippage between the chain 12 and the secondary pulley 11 and improve the fuel efficiency of the engine 1 that operates the oil pump 36 (effect corresponding to claim 3). For example, even if the meshing groove 12a of the chain 12 is meshed with the movable tooth 40, the energizing force of the movable tooth 40 is lost if the pinching pressure of the secondary pulley 11 decreases and the torque that the movable tooth 40 takes becomes too large. As a result, the movable teeth 40 are retracted radially inward, and slippage may occur between the chain 12 and the secondary pulley 11, but this can be suppressed.

  The secondary pulley pressure reduction amount is learned, and the secondary pulley pressure is reduced based on the learned value from the next shift control. As a result, the calculation of the deviation between the actual primary pulley pressure and the target primary pulley pressure is not performed from the next shift control, and the increase in the primary pulley pressure is suppressed based on the learning value, and the gear ratio is changed to the highest level. (Effect corresponding to claim 4).

  When the post-reduction secondary pulley pressure is lower than the minimum secondary pulley pressure, the minimum secondary pulley pressure is set as the target secondary pulley pressure. Thereby, it can suppress that a slip generate | occur | produces between the chain 12 and the secondary pulley 11 (effect corresponding to Claim 5).

  Even if the actual gear ratio is the gear ratio at which the meshing groove 12a of the chain 12 meshes with the movable tooth 40, the actual primary pulley pressure does not exceed the predetermined value, and the meshing groove 12a of the chain 12 meshes with the movable tooth 40. If it is determined that it is not, it is determined that an abnormality has occurred in at least one of the movable teeth 40, the spring 41, and the chain 12. Thereby, it is possible to detect the occurrence of an abnormality in the movable tooth 40, the spring 41, and the chain 12 (effect corresponding to claim 6).

  Even if the actual gear ratio is the gear ratio at which the meshing groove 12a of the chain 12 meshes with the movable teeth 40, the actual primary pulley pressure is lower than the predetermined hydraulic pressure when the meshing groove 12a of the chain 12 meshes with the movable teeth 40 In addition, it is determined that the meshing groove 12 a of the chain 12 is not meshed with the movable tooth 40. By determining the occurrence of an abnormality in the movable tooth 40, the spring 41, and the chain 12 based on the actual primary pulley pressure that is increased when the meshing groove 12a of the chain 12 and the movable tooth 40 are engaged, the movable tooth 40, the spring 41, The occurrence of an abnormality in the chain 12 can be detected (effect corresponding to claim 7).

  When it is determined that an abnormality has occurred in at least one of the movable teeth 40, the spring 41, and the chain 12, the gear ratio is limited to a gear ratio at which the meshing groove 12a of the chain 12 and the movable teeth 40 do not mesh. Thereby, it can suppress that the state of the movable tooth 40 in which abnormality generate | occur | produced, the spring 41, and the chain 12 deteriorates further (the effect corresponding to Claim 8).

  When it is determined that an abnormality has occurred in at least one of the movable teeth 40, the spring 41, and the chain 12, a warning lamp is turned on. Thus, it is possible to notify the driver that an abnormality has occurred (effect corresponding to claim 10).

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  In the above embodiment, it is determined whether the meshing groove 12a of the chain 12 and the movable tooth 40 are meshed based on the primary pulley pressure, but the position of the movable conical plate 11a of the secondary pulley 11, the chain 12 and the movable tooth 40, and so on. You may determine based on the sound, vibration, etc. which generate | occur | produce when hit.

  In the above embodiment, it is determined that an abnormality has occurred in at least one of the movable teeth 40, the spring 41, or the chain 12 based on the primary pulley pressure, and the meshing groove 12a of the chain 12 and the movable teeth 40 are not meshed. However, the determination may be made based on oil vibration, sound, or the like.

  In the above embodiment, the engine 1 is used as a power source, but a motor or an engine and a motor may be used as the power source.

  In the above embodiment, the chain 12 is used as the power transmission part (band body) of the continuously variable transmission 5. However, a power transmission part that transmits power on the pull side, for example, a rubber belt that can mesh with the movable teeth 40 may be used. Good.

  In the above embodiment, the movable teeth 40 are provided on the secondary pulley 11, but the movable teeth 40 may be provided on the primary pulley 10.

  In the above embodiment, the gear ratio is limited when any one of the movable teeth 40, the spring 41, and the chain 12 is abnormal. However, the gear ratio is not limited, and the meshing groove 12a of the chain 12 and the movable teeth 40 are not limited. The secondary pulley pressure may not be reduced when the two mesh with each other. Thereby, it can suppress that a slip generate | occur | produces between the chain 12 and the secondary pulley 11 (effect corresponding to Claim 9).

  In the above embodiment, the continuously variable transmission 5 using the step motor 71 and the shift control valve 37 has been described. However, the above control is applied to a continuously variable transmission using only the pressure reducing valve 30 without using the step motor 71 or the like. can do.

1 Engine (Power source)
5 Continuously variable transmission 10 Primary pulley (first pulley)
11 Secondary pulley (second pulley)
12 Chain
12a Meshing groove (groove)
20 CVT control unit (meshing judging means, hydraulic control means, gear ratio calculating means, learning means, abnormality judging means, limiting means, notification means)
27 Primary pulley pressure sensor (hydraulic pressure detecting means)
36 Oil pump 40 Movable teeth 41 Spring (biasing means)

Claims (11)

A first pulley having a first movable conical plate that moves in the axial direction in accordance with the hydraulic pressure supplied to and discharged from the first fixed conical plate and the first oil chamber;
A second fixed conical plate, a second movable conical plate that moves in the axial direction according to the hydraulic pressure supplied to and discharged from the second oil chamber, and a second pulley having movable teeth that are movable in the radial direction of the shaft portion;
A groove that is wound between the first pulley and the second pulley to transmit power between the first pulley and the second pulley and engage with the movable teeth is formed on the inner peripheral surface. An annular belt,
Urging means for urging the movable teeth radially outward of the shaft portion;
A continuously variable transmission that includes an oil pump that is driven by a power source and supplies hydraulic pressure to the first oil chamber and the second oil chamber;
Meshing determining means for determining whether or not the groove of the belt is meshed with the movable tooth;
Steplessly characterized by comprising: a hydraulic control means for lowering the hydraulic pressure of the second oil chamber when the engagement determining means determines that the groove of the belt body is engaged with the movable tooth. transmission. The continuously variable transmission according to claim 1,
Gear ratio calculating means for calculating a gear ratio between the first pulley and the second pulley;
Oil pressure detecting means for detecting the oil pressure of the first oil chamber;
In the meshing determination means, the gear ratio becomes a predetermined gear ratio at which the groove meshes with the movable tooth, and the hydraulic pressure of the first oil chamber detected by the hydraulic pressure detection means is input to the first pulley. A continuously variable transmission that determines that the groove meshes with the movable tooth when the hydraulic pressure is greater than or equal to a predetermined hydraulic pressure calculated based on an input torque. The continuously variable transmission according to claim 2,
The continuously variable transmission, wherein the hydraulic pressure control means increases a hydraulic pressure drop amount of the second pulley as the hydraulic pressure of the first oil chamber detected by the hydraulic pressure detection means increases. The continuously variable transmission according to claim 3,
Learning means for learning a hydraulic pressure drop amount of the second pulley;
The continuously variable transmission, wherein the hydraulic control means reduces the hydraulic pressure of the second pulley based on the hydraulic pressure reduction amount learned by the learning means. A continuously variable transmission according to any one of claims 1 to 4,
The continuously variable transmission, wherein the hydraulic control means does not lower the hydraulic pressure of the second oil chamber below a lower limit hydraulic pressure. A continuously variable transmission according to any one of claims 1 to 5,
When the gear ratio is a predetermined gear ratio at which the groove meshes with the movable tooth and the mesh determination means determines that the groove does not mesh with the movable tooth, the movable tooth, the attachment A continuously variable transmission comprising: an urging means; and an abnormality determining means for determining that an abnormality has occurred in at least one of the belts. The continuously variable transmission according to claim 6,
A hydraulic pressure detecting means for detecting the hydraulic pressure of the first oil chamber;
The meshing determination means has the gear ratio as the predetermined gear ratio, and the hydraulic pressure of the first oil chamber detected by the hydraulic pressure detection means is a hydraulic pressure when the groove meshes with the movable tooth, A continuously variable transmission that determines that the groove is not engaged with the movable tooth when the hydraulic pressure is lower than a predetermined hydraulic pressure calculated based on an input torque input to one pulley. The continuously variable transmission according to claim 6 or 7,
When the abnormality determining means determines that an abnormality has occurred in at least one of the movable teeth, the urging means, and the belt, the gear ratio is meshed with the movable teeth. A continuously variable transmission, characterized by comprising limiting means for limiting to a non-performing gear ratio. The continuously variable transmission according to claim 6 or 7,
The hydraulic pressure control unit determines the hydraulic pressure of the second oil chamber when it is determined by the abnormality determination unit that an abnormality has occurred in at least one of the movable teeth, the biasing unit, and the belt. A continuously variable transmission characterized by not lowering the speed. A continuously variable transmission according to any one of claims 6 to 9,
And a notification means for notifying the occurrence of an abnormality when the abnormality determination means determines that an abnormality has occurred in at least one of the movable tooth, the biasing means, and the belt. Continuously variable transmission. A first pulley having a first movable conical plate that moves in the axial direction in accordance with the hydraulic pressure supplied to and discharged from the first fixed conical plate and the first oil chamber;
A second fixed conical plate, a second movable conical plate that moves in the axial direction according to the hydraulic pressure supplied to and discharged from the second oil chamber, and a second pulley having movable teeth that are movable in the radial direction of the shaft portion;
A groove that is wound between the first pulley and the second pulley to transmit power between the first pulley and the second pulley and engage with the movable teeth is formed on the inner peripheral surface. An annular belt,
Urging means for urging the movable teeth radially outward of the shaft portion;
A control method for controlling a continuously variable transmission that is driven by a power source and includes an oil pump that supplies hydraulic pressure to the first oil chamber and the second oil chamber,
Determining whether the groove of the belt is engaged with the movable tooth;
A control method characterized by lowering the hydraulic pressure of the second oil chamber when it is determined that the groove of the belt is engaged with the movable tooth.

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