JP2013181655A - Speed change control device for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed change control device for a continuously variable transmission with which a belt return failure in a pulley is eliminated.SOLUTION: In a speed change control device for a continuously variable transmission, a belt 30 is wound on a pair of pulleys 10, 20, a groove width of a primary pulley 10 is changed to set a transmission ratio, and a groove width of a secondary pulley 20 is narrowed by an axial thrust to generate a force for clamping the belt, wherein an auxiliary transmission mechanism 50 for generating another thrust acting to narrow the groove width of the secondary pulley 20 based on a torque of a motor 51 is provided to be coupled with the secondary pulley 20, a connection/disconnection mechanism 90 for connecting/disconnecting another thrust is further provided, and when a request to quickly increase a transmission ratio is generated, the connection/disconnection mechanism 90 is brought into an engagement state to drive the motor 51.

Description

  In the present invention, a dry belt is wound around a driving pulley and a driven pulley to transmit power, and the gear ratio is continuously changed by continuously changing the winding diameter of the belt. The present invention relates to a shift control device for a step transmission.

  A belt-type continuously variable transmission continuously changes speed by winding an endless belt around a belt winding groove formed on a pair of pulleys and changing the belt winding diameter by changing the width of the V groove. It has a configuration to do. Specifically, the belt-type continuously variable transmission transmits the output of the power source by frictional engagement between each pulley and the belt, and approaches a fixed sheave integrated with a rotating shaft. Alternatively, a movable sheave that is slidable in the axial direction so as to be separated is provided, and a continuous gear ratio is obtained by sliding the movable sheave in the axial direction by a mechanism for changing the groove width of the pulley.

  As a mechanism for causing the pulley to generate a force for changing the groove width of the pulley and pinching the belt, for example, based on a mechanism including a hydraulic chamber to which hydraulic oil is supplied or power transmitted from the power source by the machine. The mechanism that operates is well known.

  Further, in a dry belt type continuously variable transmission using a so-called dry belt, since a lubricating liquid film is not formed in a portion where the pulley and the belt are frictionally engaged, the leaked oil is not A mechanism configured so as not to reach the frictional engagement portion or a mechanism capable of sliding and controlling the movable sheave in the axial direction by a mechanical force is used.

  For example, in Patent Document 1, when belt return is caused by deceleration, the line pressure is increased in order to quickly change the speed ratio to the maximum value required at the start or a value close thereto. A configured device is described. Patent Document 2 describes a belt-type continuously variable transmission for a vehicle that includes an engine and a motor generator as driving sources, and the CVT gear ratio is not greater than a predetermined gear ratio that can be started. Discloses that the vehicle is started by the driving force of the motor generator to solve the shortage of the driving force when the belt return failure occurs. Furthermore, Patent Document 3 discloses a belt-type continuously variable transmission that suppresses belt slip by reducing clutch pressure when a belt return failure occurs.

JP-A-6-109121 JP 2006-234043 A JP 2007-177832 A

  The continuously variable transmissions described in the above-mentioned patent documents are so-called wet continuously variable transmissions that allow oil to intervene between the belt and the pulley, and thus set the transmission ratio. A hydraulic chamber is provided not only on the primary pulley but also on the secondary pulley side.

  However, this type of wet continuously variable transmission has problems such as the need for high hydraulic pressure, and so-called dry-type continuously variable transmissions have been developed to solve this problem. In the dry continuously variable transmission, the hydraulic pressure is not used as much as possible. For example, the thrust for sandwiching the belt with the secondary pulley is transmitted between the movable sheave in the secondary pulley and the secondary shaft. It is comprised so that it may produce based on a torque.

  Therefore, when the accelerator pedal is returned and the vehicle is decelerating, the torque that is the source of the thrust becomes small. Even if sudden deceleration is required in this state and the gear ratio is changed toward the maximum value, the belt wrapping diameter at the secondary pulley is quickly increased because the force to pinch the belt at the secondary pulley is small. There is a possibility that a so-called belt return failure occurs without increasing, resulting in insufficient acceleration at the time of reacceleration after sudden deceleration or at the time of restart, that is, the acceleration of starting.

  The present invention has been made paying attention to the above technical problem, and even if the vehicle is suddenly decelerated, the belt return failure can be eliminated, and accordingly the start acceleration can be improved. An object of the present invention is to provide a transmission control device for a continuously variable transmission.

  In order to achieve the above object, in the invention according to claim 1, the belt is wound around at least a pair of pulleys capable of changing the groove width of the belt winding groove, and the groove width of the primary pulley sets the transmission ratio. In a transmission control device for a continuously variable transmission, the groove width of the secondary pulley is reduced so that the groove width of the secondary pulley is reduced by an axial thrust so as to generate a force for pinching the belt. An auxiliary transmission mechanism for generating another thrust acting on the motor based on the torque of the motor is provided in connection with the secondary pulley, and a connecting / disconnecting mechanism for connecting / disconnecting the other thrust is further provided to speed up the gear ratio. It is configured to drive the motor with the connection / disconnection mechanism engaged when a request to increase is generated. .

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the auxiliary speed change mechanism includes a rotation propulsion member that is formed with a screw portion and rotates by the torque of the motor and moves back and forth in the axial direction. A speed change control device for a continuously variable transmission.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the stepless connection mechanism is configured to be in an engaged state when the brake pedal force is equal to or greater than a threshold value. A transmission control apparatus for a transmission.

  According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, when the vehicle speed is less than or equal to a threshold value, the connection / disconnection mechanism is configured to be in an engaged state. A shift control device.

  According to the first aspect of the present invention, when a request for rapidly increasing the gear ratio occurs, the torque of the motor can be transmitted to the auxiliary transmission mechanism by engaging the connection / disconnection mechanism, and the groove width of the secondary pulley is changed. Therefore, the belt return failure can be solved and the start acceleration can be improved. That is, drivability can be improved. In addition, the groove width of the secondary pulley can be controlled, and the connection / disconnection mechanism can be released when the control is unnecessary, so that loss can be reduced. Further, since the transmission is shifted by transmitting the thrust by connecting the machine, the speed ratio can be increased quickly, so that the responsiveness is improved.

  According to the second aspect of the present invention, since the auxiliary transmission mechanism includes the rotation propulsion member having the threaded portion, the torque of the motor transmitted to the rotation propulsion member can be reliably converted into thrust in the axial direction. , Loss can be reduced.

  According to the invention of claim 3, when the brake pedal force is larger than the threshold value, for example, at the time of sudden braking, the start acceleration performance at the time of re-acceleration after deceleration or at the time of restart is improved.

  According to the fourth aspect of the present invention, even when the torque that can be started is increased below the predetermined vehicle speed, the vehicle can be started and the acceleration performance can be improved.

It is the skeleton figure which showed typically an example of the transmission control apparatus of the continuously variable transmission in one Embodiment of this invention. It is the flowchart which showed an example of the shift control process in a secondary pulley. 4 is a time chart showing a relationship among a vehicle speed, a brake pedal force, a gear ratio of a belt type continuously variable transmission, and an operating state of an auxiliary transmission mechanism.

  Hereinafter, the present invention will be described based on specific examples. First, referring to FIG. 1, a description will be given of a transmission control device for a continuously variable transmission according to an embodiment of the present invention. FIG. 1 is a skeleton diagram schematically showing a belt-type continuously variable transmission 5 that is shifted by a transmission control device for a continuously variable transmission according to this embodiment. The belt type continuously variable transmission 5 is disposed on a power transmission path from a power source of a vehicle to a drive wheel, and has a pair of primary pulleys 10 and secondary pulleys 20 and an endless shape wound around the pulleys 10 and 20. Belt 31 and continuously changing the gear ratio to increase / decrease torque and transmit power.

  The power source of the vehicle is mainly composed of an internal combustion engine such as a gasoline engine or a diesel engine or a motor, and is configured to control power output based on an output operation such as an accelerator operation by a driver. ing.

  The power output from the power source of the vehicle is transmitted to a transmission mechanism such as a torque converter or a forward / reverse switching mechanism via the output shaft of the power source. For example, when the transmission mechanism is a forward / reverse switching mechanism, the forward / reverse direction of the rotational direction of the power is switched by switching the rotational direction of the rotating element constituting the forward / reverse switching mechanism to forward / reverse. A primary shaft 4 that is a rotation shaft on the input side of the belt-type continuously variable transmission 5 is connected to the output side of the transmission mechanism, and the belt-type continuously variable transmission via the primary shaft 4 from the output side of the transmission mechanism. Power is transmitted to the machine 5.

  The belt type continuously variable transmission 5 includes a pair of a primary shaft 4 and a secondary shaft 6 that are parallel to each other. The primary shaft 4 is provided with a primary pulley 10 that rotates integrally with the primary shaft 4. The secondary shaft 6 is provided with a secondary pulley 20 that rotates integrally with the secondary shaft 6. Further, an endless belt 31 is wound around a belt winding groove formed on each of the pulleys 10 and 20 on a pair of pulleys including the primary pulley 10 and the secondary pulley 20.

  The belt 31 is a so-called dry belt, a dry composite belt, a metal belt, a resin rubber belt, or the like. For example, a metal belt composed of a plurality of elements and laminated rings, a dry composite belt composed of a tension band having a core wire as a resin power transmission member (tensile member) and an element, and resin power For example, a rubber belt having a core wire as a transmission portion.

  Further, a thrust applying mechanism 30 that generates axial thrust for changing the groove width of the belt winding groove of the primary pulley 10 is provided. Based on the thrust, the groove width of the primary pulley 10 is changed to set the transmission ratio. That is, the belt winding diameter of the primary pulley 10 is changed.

  Here, the primary pulley 10 and the thrust applying mechanism 30 will be specifically described. The primary pulley 10 includes a fixed sheave 11 that is integrated with the primary shaft 4 and a movable sheave 12 that is splined to the primary shaft 4 and configured to be slidable in the axial direction. The inclined surface 11a of the fixed sheave 11 and the inclined surface 12a of the movable sheave 12 face each other to form a belt winding groove (V groove) having a V-shaped cross section.

  When the primary pulley 10 around which the belt 31 is wound around the V-groove is rotated, the inclined surfaces 11a and 12a of the sheaves 11 and 12 are frictionally engaged by contact with the belt 31 to generate a frictional force. Power is transmitted to the belt 31 based on the force. That is, power is transmitted from the primary shaft 4 to the belt 31 via the primary pulley 10 by the frictional force.

  On the back side opposite to the inclined surface 12 a of the movable sheave 12, a rotation propelling member 34 that generates axial thrust is provided. The rotation propelling member 34 is configured to be provided in the thrust applying mechanism 30, and the thrust applying mechanism 30 applies a thrust that slides toward the fixed sheave 11 to the movable sheave 12.

  The thrust applying mechanism 30 is configured to generate axial thrust based on power transmitted from a power source different from the power source of the vehicle described above. Specifically, the thrust applying mechanism 30 rotates based on the motor 31 that is a power source for changing the groove width of the primary pulley 10 and the torque output by the motor 31 and linearly moves in the axial direction. And a rotation propelling member 34. That is, the rotation propelling member 34 converts the rotational force (torque) output from the motor 31 into axial thrust. The generated thrust is transmitted to the movable sheave 12. In addition, the motor 31 is provided at an axis center different from the axis center of the primary shaft 4, is supplied with electric power from a battery (not shown), and is controlled by the electronic control device 100.

  A transmission member that increases or decreases the output torque of the motor 31 and increases or decreases the number of revolutions may be provided in a power transmission path from the motor 31 to the rotation propulsion member 34 in the thrust applying mechanism 30. That is, the output torque of the motor 31 is increased and transmitted to the rotation propelling member 34 via the transmission member. For example, as the transmission member, one or a plurality of intermediate shafts are provided so as to be parallel to the output shaft 31a and the primary shaft 4 of the motor 31, and the same intermediate shaft is formed with different radii and intermediate. A plurality of input / output elements that rotate integrally with the shaft are provided.

  Specifically, the first transmission member 32 provided on the motor 31 side in the power transmission path includes a first intermediate shaft 32a, and the second transmission member 33 provided on the rotation propulsion member 34 side is the second. An intermediate shaft 33a is provided. The intermediate shafts 32a and 33a are provided in parallel with each other, and are rotatably held by bearings (not shown) connected to the belt-type continuously variable transmission 5 or a housing that houses the motor 31, respectively.

  The first intermediate shaft 32a has a driven gear 32b that meshes with a drive gear 31b that is connected so as to rotate integrally with the output shaft 31a of the motor 31, and a second intermediate shaft that has a smaller diameter than the driven gear 32b. The drive gear 32c meshing with the driven gear 33b of 33a is connected so as to rotate integrally.

  The second intermediate shaft 33 has a driven gear 33a that meshes with the drive gear 32b of the first intermediate shaft 32a, and a drive that has a smaller diameter than the driven gear 33a and meshes with the driven gear 34a of the rotary propulsion member 34. The gear 33b is connected to rotate integrally. The driven gear 33b and the drive gear 34a are configured to be slidable in the axial direction. The axial length of either of the gears 33b and 34a is formed to be equal to or longer than the distance that the rotary propelling member 34 slides in the axial direction. The drive gear 31b of the motor 31 and the driven gear 34a of the rotation propelling member 34 may mesh with each other without providing the transmission member as described above.

  The rotation propulsion member 34 includes a driven gear 34a that protrudes radially outward from the hollow cylindrical portion 34b, and a screw portion 34c formed in the cylindrical portion 34b. That is, the radius of the driven gear 34a of the rotation propelling member 34 is formed larger than the radius of the threaded portion 34c. Further, the threaded portion 34c is formed in multiple lines, and the length in the axial direction is longer than the distance that the rotation propelling member 34 slides in the axial direction.

  On the back side of the movable sheave 12, a fixing member (not shown) fixed to a housing that houses the primary pulley 10 is provided. The fixing member is provided with a screw portion that is screwed with the screw portion 34 c of the rotation propelling member 34. Further, the threaded portion of the fixing member is formed in multiple lines, and the length in the axial direction is longer than the distance that the rotation propelling member 34 slides in the axial direction. Note that either the screw portion 34c of the rotation propelling member 34 or the screw portion of the fixing member may be a male screw or a female screw.

  Therefore, the rotational motion of the rotation propelling member 34 is converted into a linear motion in the axial direction by the screw portion 34c of the rotation propelling member 34 and the screw portion of the fixing member. That is, the rotational force of the rotation propelling member 34 is converted into axial thrust. Then, the thrust of the rotation propelling member 34 that slides in the axial direction toward the back surface of the movable sheave 12 is transmitted to the movable sheave 12 to change the groove width of the primary pulley 10. In other words, the groove width of the primary pulley 10 is configured to be changed so as to set the gear ratio.

  In other words, the fixing member is configured to rotate relative to the rotation propelling member 34. The rotation propelling member 34 that moves back and forth in the axial direction while rotating, and the fixing member that is screwed to the rotation propelling member 34 function as a so-called feed screw.

  Further, the rotation propelling member 34 is held by a bearing 61 provided in the cylindrical portion of the movable sheave 12. Therefore, the movable sheave 12 and the rotation propelling member 34 are configured to be relatively rotatable. The bearing 61 moves back and forth integrally with the movable sheave 12 in the axial direction. The bearing 61 may move back and forth integrally with the rotation propelling member 34 in the axial direction or may not move back and forth integrally. That is, when the thrust of the rotation propelling member 34 is transmitted to the movable sheave 12, the rotation propelling member 34 and the back surface of the movable sheave 12 may be transmitted in contact with each other, or may be transmitted via the bearing 61.

  Next, the secondary pulley 20, the thrust applying mechanism 40, and the auxiliary transmission mechanism 50 that are connected to the secondary shaft 6 will be described in detail. In the secondary pulley 20, an inclined surface 21 a of a fixed sheave 21 integrated with the secondary shaft 6 and an inclined surface 22 a of a movable sheave 22 configured to be slidable in the axial direction on the secondary shaft 6 face each other. Thus, a V groove around which the belt 31 is wound is formed.

  The secondary pulley 20 includes a fixed sheave 21 that is integrated with the secondary shaft 6 and a movable sheave 22 that is fitted to the secondary shaft 6 and configured to be slidable in the axial direction. The inclined surface 21a of the fixed sheave 21 and the inclined surface 22a of the movable sheave 22 are opposed to each other to form a so-called V groove having a V-shaped cross section.

  Therefore, when the belt 31 operates based on the rotational movement of the primary pulley 10, the secondary pulley 20 rotates. Specifically, the inclined surfaces 21a and 22a of the sheaves 21 and 22 of the secondary pulley 20 are frictionally engaged by contact with the belt 31 to generate a frictional force, and power is transmitted from the belt 31 based on the frictional force. The secondary pulley 20 thus rotated rotates. That is, the groove width of the secondary pulley 20 is narrowed by the axial thrust so as to generate a force (belt clamping pressure) for clamping the belt 31. Therefore, power is transmitted from the belt 31 to the secondary shaft 6 through the secondary pulley 20 by the frictional force.

  On the back side of the movable sheave 22 opposite to the inclined surface 22a, there are provided a thrust applying mechanism 40 and an auxiliary transmission mechanism 50 that generate thrust in the axial direction for generating a force with which the secondary pulley 20 clamps the belt 31. ing. Further, the thrust generated by the thrust applying mechanism 40 and the auxiliary transmission mechanism 50 is configured to be applied to the secondary pulley 20. That is, based on the thrust generated by the thrust applying mechanism 40 and the auxiliary transmission mechanism 50, the groove width of the secondary pulley 20 is narrowed to generate a force for pinching the belt 31. Therefore, the secondary pulley 20 generates a belt clamping pressure based on the thrust and generates a tension of the belt 31.

  Here, the thrust imparting mechanism 40 will be specifically described. The thrust applying mechanism 40 includes a torque cam mechanism. The torque cam mechanism includes a pair of rotating members including an input cam member to which power transmitted from a power source of the vehicle is input and an output cam member to which power is transmitted from the input cam member. . Moreover, it is comprised so that relative rotation is possible based on the torque transmitted from the motive power source of the vehicle, and the rotational force is converted into the thrust of an axial direction by the relative rotation. Therefore, a torque cam mechanism is provided in the power transmission path from the power source of the vehicle to the drive wheels. When the input cam member is the movable sheave 22, the output cam member is fixed in the axial direction.

  For example, the input side cam member is fitted to the secondary shaft 6 so as to be relatively rotatable, and the output side cam member is fitted to the secondary shaft 6 by spline. In this case, the power transmitted from the belt 31 to the secondary pulley 20 is transmitted to the secondary shaft 6 via the fixed sheave 21 and also transmitted to the secondary shaft 6 via the input side cam member and the output side cam member. .

  The input cam member and the output cam member are formed with cam surfaces that are inclined at a predetermined cam angle from the circumferential direction and are opposed in the axial direction. In other words, the cam surface is formed in an uneven shape that is continuous in the circumferential direction.

  When the cam surfaces of the circumferentially facing portions are frictionally engaged with each other based on the rotational motion of the torque cam mechanism, the cam surfaces are friction surfaces, and the circumferential tangential direction acting on the friction engaging portion The rotational force is decomposed into a component force in the axial direction by a cam surface having a predetermined cam angle to generate a thrust. That is, a part of the rotational force transmitted from the power source of the vehicle by the torque cam mechanism is converted into thrust in the axial direction. The thrust generated by the torque cam mechanism, that is, the thrust generated by the thrust applying mechanism 40 is transmitted to the secondary pulley 20. Note that a torque cam mechanism configured to convert a rotational force into a thrust force by inserting a friction rolling element, a so-called friction roller, between cam surfaces may be used.

  In addition, the thrust applying mechanism 40 may include an elastic member that generates a thrust for generating belt clamping pressure in the secondary pulley 20 in an initial state where power is not transmitted from the power source of the vehicle to the secondary pulley 20. . The elastic member has a shape elasticity property that changes its shape by an external force in the axial direction. For example, a coil spring disposed so as to be elastically deformed in the axial direction can be used. In this case, the thrust in the axial direction in which the coil spring is generated is configured to be applied to the secondary pulley 20.

  Next, the auxiliary transmission mechanism 50 will be described. The auxiliary speed change mechanism 50 is configured to generate axial thrust based on the output torque of a power source different from the power source of the vehicle. In other words, the auxiliary transmission mechanism 50 is a rotational propulsion that rotates based on the power source for shifting for changing the groove width of the secondary pulley 20 and the torque output from the power source for shifting, and linearly moves in the axial direction. And a member 54.

  As a power source for shifting the auxiliary transmission mechanism 50, a motor provided for driving another device mounted on the vehicle can be used in combination. For example, a motor 51 for driving an electric oil pump 71 that supplies lubricating oil to a lubricating portion 73 that requires lubricating oil via an oil passage 72 is used as a power source for shifting the auxiliary transmission mechanism 50. The motor 51 is supplied with electric power from a battery (not shown) and is controlled by the electronic control unit 100. The motor 51 and the electric oil pump 71 are configured to be able to transmit power via a transmission member 51 c, and the transmission member 51 c is the same rotational axis as the output shaft 51 a of the motor 51.

  Further, the power transmission path of the auxiliary transmission mechanism 50 from the motor 51 to the rotation propelling member 54 is provided with a transmission member that forms the power transmission path and a connection / disconnection mechanism 90 that connects or disconnects the power transmission path. It has been. The connection / disconnection mechanism 90 is controlled by the electronic control unit 100, and when a request for rapidly increasing the gear ratio occurs, the connection or disconnection (connection / disconnection) between the motor 51 and the rotation propelling member 54 is automatically performed. It is configured to be able to. As the connection / disconnection mechanism 90 in this embodiment, a clutch 52 whose operation is controlled by the electronic control unit 100 via an actuator 91 is provided. The request for rapidly increasing the gear ratio is, for example, when the brake pedal or the like is suddenly depressed, that is, when the vehicle is suddenly braked.

  The clutch 52 which is the connection / disconnection mechanism 90 is configured to be engaged by frictionally engaging the transmission members, for example. That is, the engagement state is switched to the release state by releasing the frictional engagement. Specifically, the clutch 52 is a cylinder in which a transmission member 51b connected so as to rotate integrally with the output shaft 51a of the motor 51 and a drive gear 53a meshing with the driven gear 54a of the rotation propelling member 54 are formed. It is comprised so that it may engage or release with the transmission member 53 of a shape.

  Accordingly, the clutch 52 frictionally engages the rotating transmission members. For example, a dry clutch, a wet clutch, a single-plate clutch, a multi-plate clutch, an electromagnetic clutch, etc. To communicate.

  When the clutch 51 is engaged and the motor 51 is driven, the transmission member 53 that rotates integrally with the output shaft 51a of the motor 51 rotates the rotation propelling member 54 that meshes with the drive gear 53a. That is, the output torque of the motor 51 can be transmitted to the rotation propelling member 54. Furthermore, the driven gear 53a and the drive gear 54a are configured to be slidable in the axial direction. The axial length of either one of the gears 53a and 54a is formed to be equal to or longer than the distance that the rotary propelling member 54 slides in the axial direction.

  The rotation propelling member 54 to which the output torque of the motor 51 is transmitted functions as an output member in the auxiliary transmission mechanism 50. The rotation propelling member 54 is configured to convert the rotational force transmitted from the motor 51 into an axial thrust.

  Specifically, the rotation propelling member 54 includes a driven gear 54a that protrudes radially outward from the hollow cylindrical portion 54b and a screw portion 54c formed in the cylindrical portion 54b. That is, the radius of the driven gear 54a of the rotation propelling member 54 is formed larger than the radius of the screw portion 54c. Further, the threaded portion 54c is formed in multiple lines, and the length in the axial direction is longer than the distance that the rotation propelling member 54 slides in the axial direction.

  On the back side of the movable sheave 22 of the secondary pulley 20, a fixing member (not shown) that is fixed to a housing that houses the secondary pulley 20 is provided. The fixing member is provided with a screw portion that is screwed with the screw portion 54c of the rotation propelling member 54. Further, the threaded portion of the fixing member is formed in multiple lines, and the length in the axial direction is longer than the distance that the rotation propelling member 54 slides in the axial direction. Note that either the screw portion 54c of the rotation propelling member 54 or the screw portion of the fixing member may be a male screw or a female screw.

  Therefore, the rotational motion of the rotation propelling member 54 is converted into a linear motion in the axial direction by the screw portion 54c of the rotation propelling member 54 and the screw portion of the fixing member. That is, the rotational force of the rotation propelling member 54 is converted into axial thrust. Then, the thrust of the rotation propelling member 54 that slides in the axial direction toward the back surface of the movable sheave 22 is transmitted to the movable sheave 22 to change the groove width of the secondary pulley 20. That is, the groove width of the secondary pulley 20 is changed to change the transmission gear ratio.

  In other words, the fixing member is configured to rotate relative to the rotation propelling member 54. The rotation propelling member 54 that moves back and forth in the axial direction while rotating, and the fixing member that is screwed to the rotation propelling member 54 function as a so-called feed screw.

  Further, the rotation propelling member 54 is held by a bearing 63 provided in the cylindrical portion of the movable sheave 22 of the secondary pulley 20. Therefore, the movable sheave 22 and the rotation propelling member 54 are configured to be relatively rotatable. The bearing 63 moves back and forth integrally with the movable sheave 22 in the axial direction. The bearing 63 may move back and forth integrally with the rotary propelling member 54 in the axial direction or may not move back and forth integrally in the axial direction. That is, when the thrust of the rotation propelling member 54 is transmitted to the movable sheave 22, the rotation propelling member 54 and the back surface of the movable sheave 22 may or may not contact each other. That is, the thrust of the auxiliary transmission mechanism 50 may be transmitted to the secondary pulley 20 via the bearing 61.

  The belt-type continuously variable transmission 5 configured as described above increases or decreases the torque transmitted to the primary shaft 4 and transmits it to the output-side secondary shaft 6. And the secondary shaft 6 is connected with the drive wheel through the differential gear and drive shaft which are not shown in figure. In other words, the transmission torque output from the belt type continuously variable transmission 5 is transmitted to the drive wheels via the secondary shaft 6 and the drive shaft, and generates a driving force in the drive wheels.

  Further, an electronic control device 100 is provided as a controller for controlling the belt type continuously variable transmission 5. The electronic control device 100 is composed of a processing unit (CPU), a storage device (RAM and ROM), and a microcomputer mainly including an input / output interface.

  For the electronic control unit 100, the engine speed, the vehicle speed V, the vehicle acceleration, the accelerator pedal operation state, the brake pedal operation state, the brake pedaling force B, the primary shaft 4 rotation speed, and the secondary shaft 6 rotation speed. A sensor signal for detecting the rotational speed of the drive shaft, the rotational speed of the drive wheel, and the like is input. In addition, the vehicle speed V may be calculated | required based on the rotation speed of the secondary shaft 6, or the rotation speed of a drive shaft, or the rotation speed of a drive wheel. Further, the brake depression force B may be obtained based on the operation state of the brake pedal.

  Various data are stored in the storage device of the electronic control device 100 together with various control programs. Therefore, based on the signal input to the electronic control device 100 and stored data, a signal for controlling the belt type continuously variable transmission 5 from the electronic control device 100, for example, a signal is output to the actuator 91.

  Next, the shift control in this embodiment will be described with reference to FIGS. FIG. 2 is a flowchart showing an example of shift control by the electronic control unit 100. FIG. 3 is a time chart for explaining the shift control. In FIG. 3, the vehicle speed V, the brake pedal force B, the transmission gear ratio γ of the belt type continuously variable transmission 5, and the operating state of the auxiliary transmission mechanism 50 are shown by solid lines. Further, in order to explain the shift control, it is assumed that the vehicle is traveling in a state of steady traveling, that is, the groove width of the secondary pulley 20 is changed only by the thrust of the thrust applying mechanism 40 (before time t1). Then, from the steady running state, the vehicle starts to decelerate based on the operation of the brake pedal or the like at time t1.

  First, in the shift control process in this embodiment, the electronic control unit 100 determines whether or not the vehicle speed V is equal to or less than a predetermined threshold value Vc (step S1). If the vehicle speed V is greater than the threshold value Vc as a result of the vehicle speed determination (No in step S1), the shift control process is terminated. Therefore, when the vehicle speed V is equal to or higher than the threshold value Vc (before time t2), the secondary pulley 20 generates the belt clamping pressure based only on the thrust generated by the thrust applying mechanism 40. That is, the groove width of the secondary pulley 20 is changed only by the thrust generated by the thrust applying mechanism 40. In other words, the secondary pulley 20 shifts in a so-called manner.

  On the other hand, as a result of the vehicle speed determination, if the vehicle speed V is less than or equal to the threshold value Vc (Yes in step S1), it is determined whether or not the brake pedal force B is greater than or equal to a predetermined threshold value Bc (step S2). As a result of the pedaling force determination, if the brake pedaling force B is smaller than the threshold value Bc (No in step S2), the shift control process is terminated.

  Accordingly, when the brake pedal force B is equal to or less than the threshold value Bc (before time t3), the secondary pulley 20 generates the belt clamping pressure based only on the thrust generated by the thrust applying mechanism 40. That is, the groove width of the secondary pulley 20 is changed only by the thrust generated by the thrust applying mechanism 40. In other words, the secondary pulley 20 shifts in a so-called manner.

  On the other hand, as a result of the pedaling force determination, if the brake pedaling force B is equal to or greater than the threshold Bc (Yes in step S2), the clutch 52 is engaged and the power transmission path in the auxiliary transmission mechanism 50 is connected (step S3). .

  That is, at time t3 when the brake pedal force B becomes equal to or greater than the threshold value Bc, the clutch 52 is engaged, and other thrust generated by the auxiliary transmission mechanism 50 is coupled to the secondary pulley 20 so as to be transmitted. In other words, the power transmission path of the auxiliary transmission mechanism 50 is connected by the engaged clutch 52, and the output torque of the motor 51 can be transmitted to the rotation propelling member 54.

  It should be noted that the engagement or release of the clutch 52 is excellent in responsiveness because it is the fastening (friction engagement) of the machine. Therefore, the power transmission path is connected in a very short time after the brake pedal force B becomes equal to or greater than the threshold value Bc. For example, when the clutch 52 is an electromagnetic clutch, the response is improved compared to a hydraulic actuator that operates by signal pressure because it is an instruction output and engagement operation by electricity.

  In the engaged state of the clutch 52, the electronic control unit 100 instructs the motor 51 connected to the secondary pulley 20 to drive the motor 51 to drive the speed ratio γ of the belt type continuously variable transmission 5. Is made not less than the threshold value γc (step S4).

  That is, the motor 51 is driven based on an output instruction signal from the electronic control device 100 and outputs motor torque. The output torque from the motor 51 is transmitted to the rotation propelling member 54 via the transmission path connected by the engagement of the clutch 52, specifically via the clutch 52 and the transmitting member, and rotates the rotation propelling member 54. Let

  Further, since the rotation propelling member 54 functions as a feed screw, the rotational motion of the rotation propelling member 54 is converted into a linear motion in the axial direction, that is, the motor torque is converted into thrust in the axial direction. Accordingly, the thrust generated by the auxiliary transmission mechanism 50 is applied to the secondary pulley 20. That is, the thrust generated by the auxiliary transmission 50 is applied to the secondary pulley 20 in addition to the thrust generated by the thrust applying mechanism 40. In other words, the thrust generated by the auxiliary transmission mechanism 50 is referred to as another thrust.

  Therefore, the secondary pulley 20 generates belt clamping pressure based on the thrust (other thrust) generated by the auxiliary transmission mechanism 50, and the groove width of the secondary pulley 20 is changed to set the transmission ratio. Specifically, since the thrust acts so as to slide the movable sheave 22 of the secondary pulley 20 toward the fixed sheave 21 in the axial direction, the V groove width of the secondary pulley 20 is narrowed, and the belt winding diameter of the secondary pulley 20 is reduced. Becomes larger. Therefore, since the ratio between the belt winding diameter of the primary pulley 10 and the belt winding diameter of the secondary pulley 20 changes, the speed ratio γ of the belt type continuously variable transmission 5 changes.

  Then, the gear ratio γ of the belt-type continuously variable transmission 5 is set to a predetermined threshold value γc or more with the motor 51 being driven (time t4). The threshold value γc is, for example, a gear ratio of the belt-type continuously variable transmission 5 that can output transmission torque that can start the vehicle. Therefore, the thrust generated by the auxiliary transmission mechanism 50 until the speed ratio γ of the belt-type continuously variable transmission 5 becomes a speed ratio (for example, speed ratio γc) at which the vehicle can start after the brake pedal force B becomes equal to or greater than the threshold value Bc. Shift control is performed based on

  Therefore, by operating the auxiliary transmission mechanism 50 to control the transmission, the belt-type continuously variable transmission can achieve a transmission ratio that cannot be achieved in the final transmission state, for example, a transmission ratio that can start the vehicle or a transmission ratio that can exhibit acceleration. A gear ratio γ of 5 can be reached. Furthermore, the responsiveness when forming the transmission path by fastening the machine and the responsiveness of the operation instruction by the electric signal can reduce the time (between t3 and t4) during the speed change control to improve the responsiveness. . Then, the electronic control unit 100 sets the speed ratio γ of the continuously variable transmission 5 to a predetermined speed ratio at which the vehicle can start, and then ends this speed change control process.

  DESCRIPTION OF SYMBOLS 4 ... Primary shaft, 5 ... Belt type continuously variable transmission, 6 ... Secondary shaft, 20 ... Secondary pulley, 21 ... Fixed sheave, 22 ... Movable sheave, 31 ... Belt, 40 ... Thrust imparting mechanism, 50 ... Auxiliary transmission mechanism, DESCRIPTION OF SYMBOLS 51 ... Motor, 52 ... Clutch, 53 ... Transmission member, 54 ... Rotation propulsion member, 90 ... Connection / disconnection mechanism, 91 ... Actuator, 100 ... Electronic control apparatus.

Claims (4)

The belt is wound around at least a pair of pulleys capable of changing the groove width of the belt winding groove, the groove width of the primary pulley is changed to set the transmission ratio, and the groove width of the secondary pulley sandwiches the belt. In a transmission control device for a continuously variable transmission that is narrowed by thrust in the axial direction so as to generate an attaching force,
An auxiliary speed change mechanism that generates another thrust that acts to narrow the groove width of the secondary pulley based on the torque of the motor is provided in connection with the secondary pulley, and a connection and disconnection mechanism that connects and disconnects the other thrust. Further provided,
A transmission control device for a continuously variable transmission, wherein the motor is driven with the connection / disconnection mechanism engaged when a request for rapidly increasing a gear ratio occurs. 2. The continuously variable transmission according to claim 1, wherein the auxiliary transmission mechanism includes a rotation propulsion member that is formed with a screw portion and that rotates by the torque of the motor and moves back and forth in the axial direction. Shift control device.   The transmission control device for a continuously variable transmission according to claim 1 or 2, wherein when the brake pedal force is greater than or equal to a threshold value, the connection / disconnection mechanism is configured to be in an engaged state.   4. The transmission control device for a continuously variable transmission according to claim 3, wherein when the vehicle speed is less than or equal to a threshold value, the connection / disconnection mechanism is configured to be in an engaged state.

Images