JP2008309229A - Stepped shift control device for continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stepped shift control device for a continuously variable transmission, enabling to transmit power through a wide-range contact point even when continuously operating the continuously variable transmission in "a stepped shift mode". <P>SOLUTION: When operating the belt type continuously variable transmission in "the stepped shift mode", three gear ratio lines different in shift property are previously set in each gear ratio line group. To equalize the working frequencies of the gear ratio lines, the working gear ratio lines are changed over in sequence each time of shift operation to the shift stage. Thus, stepped shift operation is performed while using the belt holding face of a pulley over a wide range. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for causing a continuously variable transmission mounted in an automobile or the like to perform a stepped speed change operation. In particular, the present invention relates to a measure for realizing an operation capable of improving the durability of a continuously variable transmission.

  Conventionally, as disclosed in, for example, Patent Document 1 below, a belt-type continuously variable transmission is known as a transmission mounted on the output side of an automobile engine.

  This belt-type continuously variable transmission includes a metal belt and a pair of pulleys, and is configured to realize continuous continuously variable transmission by changing the effective diameter of the pulleys by hydraulic pressure. That is, the endless metal belt is wound around the input pulley (primary pulley) attached to the input shaft and the output pulley (secondary pulley) attached to the output shaft. The primary pulley and the secondary pulley are each provided with a pair of sheaves whose groove width can be changed steplessly. By changing the groove width, the winding radius of the endless metal belt around the primary pulley and the secondary pulley, respectively. Thus, the rotational speed ratio between the input shaft and the output shaft, that is, the gear ratio can be continuously changed continuously.

  Specifically, as a control operation of this type of transmission, an ECU (Electronic Control Unit) that controls the continuously variable transmission determines a target engine output required by the driver from the accelerator opening and the vehicle speed. Then, the target rotational speed of the primary pulley is determined so that the target engine output can be realized on the optimum fuel consumption line of the engine. The ECU controls the hydraulic circuit of the continuously variable transmission so as to perform a stepless shift so that the actual rotation speed of the primary pulley detected by the primary pulley rotation speed sensor becomes the target rotation speed. The ECU that controls the engine determines the target engine torque based on the target engine output and the engine speed, and controls the engine by controlling the throttle opening. Since such a control operation is performed, in an automobile equipped with this type of continuously variable transmission, it is possible to efficiently extract the engine output and improve the fuel consumption and the driving performance. Speed change operation can be realized.

  As a type of continuously variable transmission, a toroidal continuously variable transmission is also known in addition to the above-described belt-type continuously variable transmission (see, for example, Patent Document 2 below).

  By the way, as this type of continuously variable transmission, in addition to the above-described “continuously variable transmission mode” in which continuous continuously variable transmission is performed, the vehicle speed or accelerator is selected from a plurality of predetermined gear ratios (speeds). There is also known one equipped with a “stepped transmission mode” in which one transmission ratio is selected in accordance with the opening degree or the like.

  For example, as disclosed in Patent Document 3 and Patent Document 4 below, an automatic transmission mode and a manual (manual) transmission mode are provided, and when the automatic transmission mode is selected, the continuously variable transmission is referred to as “ On the other hand, when the manual transmission mode is selected, the continuously variable transmission is operated in the “stepless transmission mode”. For example, in this manual shift mode, the gear ratio (shift stage) of the continuously variable transmission is changed according to the shift operation of the shift lever (operation at the sequential shift position, etc.), regardless of the vehicle speed or throttle opening. The driver can select a desired gear position.

  As shown in FIG. 9, when viewed in a coordinate system in which the input shaft rotational speed of the continuously variable transmission is the vertical axis and the output shaft rotational speed (or vehicle speed) is the horizontal axis, The gear ratio as indicated by the gear ratio line ABC in the figure changes steplessly and is upshifted. Further, for example, the gear ratio such as the gear ratio line CD is changed steplessly and downshifted.

  On the other hand, as shown in FIG. 10, in the “stepped speed change mode”, a plurality of speed stages (for example, the first speed: R1 to the sixth speed: R6) are shown in advance as indicated by the speed ratio lines R1 to R6 in the figure. ) Is set, and the gear position is switched to the upshift side or the downshift side one by one between these preset gear positions according to the shift operation of the shift lever by the driver. At the time of upshifting, for example, a gear ratio such as a point LMMNO-... -P on the gear ratio line in the figure is switched stepwise. Further, at the time of downshifting, for example, a gear ratio such as a point PQR-... -S on the gear ratio line in the figure is switched in a stepwise manner (see the arrow indicated by a broken line in the figure). ). In FIGS. 9 and 10, γmax is the maximum deceleration line (the limit for setting the largest reduction ratio, and in FIG. 10 substantially matches the transmission ratio line at the first speed (R1). Γmin indicates the maximum speed increasing line (limit when setting the speed reduction ratio to the minimum).

Note that there is a continuously variable transmission that operates in the “stepped transmission mode” not only when the manual transmission mode is selected but also when the automatic transmission mode is selected.
Japanese Patent Laid-Open No. 9-217819 JP 2005-180483 A JP 2004-190833 A JP 2004-346991 A

  By the way, when this type of continuously variable transmission is continuously operated in the “stepped transmission mode”, the belt wrapping position around each pulley does not change at each shift stage, and the belt in each pulley does not change. The belt travels at a specific position on the contact surface (hereinafter also referred to as a belt clamping surface). For this reason, only a part of the entire belt clamping surface of each pulley is in a situation where the contact time with the belt becomes extremely long.

  For example, as shown in FIG. 10, in the case of a continuously variable transmission in which a six-speed step-variable transmission from the first speed to the sixth speed is performed as the “stepped speed change mode”, 6 of the belt clamping surfaces in each pulley. The contact time with the belt becomes extremely long only at the points.

  In such a situation, there is a concern that the amount of wear in the portion where the contact time with the belt is long in each pulley is larger than in other portions. For this reason, in order to ensure sufficient durability, it is necessary to take measures such as configuring the belt contact surface of each pulley with a highly wear-resistant material, which may lead to an increase in manufacturing cost. there were.

  This problem is not limited to the belt-type continuously variable transmission described above, but also occurs when a step-variable shifting operation is performed in the toroidal-type continuously variable transmission. That is, the contact time with the power roller is extremely limited only at a specific portion of the power roller contact surfaces (surfaces that transmit power to and from the power roller) of the input disk and output disk of the toroidal-type continuously variable transmission. This is a problem caused by the fact that it becomes longer.

  The present invention has been made in view of the above points, and an object of the present invention is to transmit power even when the continuously variable transmission is continuously operated in the “stepped transmission mode”. A continuously variable transmission control device for a continuously variable transmission capable of extending a wide range of contact points (where the belt contacts the belt surface (belt clamping surface) in the case of a belt type continuously variable transmission) There is.

-Solving principle-
The solution principle of the present invention taken to achieve the above object is that when the continuously variable transmission is operated in the “stepped transmission mode”, the output shaft rotational speed with respect to the input shaft rotational speed of the continuously variable transmission. When the change of the output shaft speed with respect to the change of the input shaft speed is expressed in the coordinate system of the input shaft speed and the output shaft speed of the continuously variable transmission, A plurality of different lines) are set in advance as one gear. Then, by making the frequency of use of each gear ratio line belonging to the same gear stage substantially uniform, a contact point for power transmission (in the case of a belt-type continuously variable transmission, a belt contact point on the surface of the pulley) ) Is used over a wide range so that stepped speed change operation can be performed.

-Solution-
Specifically, the present invention relates to a continuously variable transmission in which a continuously variable transmission configured to be capable of continuously changing the output rotation of a drive source is changed stepwise between a plurality of preset gears. Assumes a step-variable transmission control device for a machine. With respect to this stepped transmission control device, even if the ratio of the increase amount of the output shaft rotation speed to the increase amount of the input shaft rotation speed of the continuously variable transmission is substantially the same, the output shaft A plurality of shift characteristics having different rotational speeds are set as the same shift stage. Then, during the shift operation to the shift stage having the plurality of shift characteristics, the shift characteristic is selected so that the frequency of use of each of the plurality of shift characteristics is substantially equal, and the shift operation to the shift stage is executed. Characteristic selection means is provided.

  Due to this specific matter, when a stepped speed change operation is performed by the continuously variable transmission, for example, a predetermined speed is selected according to the vehicle speed, the accelerator opening, etc., and the selected speed is If it is different from the gear position, a shift operation to the selected gear position is performed. In this case, the shift stage to be shifted (the shift stage after the shift operation is performed) has the plurality of shift characteristics (the increase amount of the output shaft rotation speed relative to the increase amount of the input shaft rotation speed of the continuously variable transmission). The ratios of the output shaft rotation speeds are different from each other even if the ratios of the input shaft rotation speeds are substantially the same. Of these, a shift characteristic that is less frequently used (less frequently used than the other shift characteristics) is selected, and a shift stage switching operation is performed so that the shift characteristic is achieved. For this reason, power transmission from the input shaft to the output shaft is performed with a different speed change characteristic for each speed change operation to this speed change stage (a speed change stage having a plurality of speed change characteristics). The belt can be contacted over a wide range while changing the contact location (in the case of a belt-type continuously variable transmission, the location where the belt contacts on the surface of the pulley (belt clamping surface)). Therefore, the concern that only a part of the contact portion is worn can be eliminated.

  In particular, in the case of this solution, as a plurality of shift characteristics belonging to the same shift stage, an operation of maintaining a constant ratio of the increase amount of the output shaft rotation speed to the increase amount of the input shaft rotation speed while changing the speed ratio. Can be done. That is, the speed ratio line indicating the change in the output shaft speed with respect to the change in the input shaft speed is represented as a straight line that does not pass through the origin in the coordinate system. In this case, for example, in a belt-type continuously variable transmission, the input shaft rotation speed and the output shaft are changed while the effective diameters of the secondary and primary pulleys are changing, that is, the belt winding position with respect to each pulley is changing. It becomes the situation where the number of revolutions changes. Accordingly, the shifting operation and the changing operation of the input shaft rotation speed and the output shaft rotation speed are performed while using the wide range of the belt clamping surface of the pulley substantially evenly, so only a part of the contact portion is performed. Thus, it is possible to reliably avoid the situation in which the wear occurs, and to improve the durability of the continuously variable transmission.

  In the above solution, only a part of the plurality of shift stages may have a plurality of shift characteristics, or all the shift stages each have a plurality of shift characteristics. It may be configured.

  In addition, as a specific configuration for making the use frequency of each speed change characteristic substantially equal by the speed change characteristic selecting means, the following can be cited. In other words, each time the shift characteristic selection means performs a shift operation to a shift stage having a plurality of shift characteristics, the plurality of shift characteristics are selected in order, and the shift is performed so that the selected shift characteristics are used. It is configured to execute the operation.

  For example, when the first to third types of shift characteristics are set for the third speed as the shift speed, the shift operation to the third speed (the shift-up operation from the second speed to the third speed, Each time a shift-down operation from the fourth speed to the third speed is performed, the first speed change characteristic, the second speed change characteristic, the third speed change characteristic, and the first speed change characteristic are selected. Change the shift characteristics in order. According to this, it is possible to equalize the frequency of use of each of the plurality of speed change characteristics by a relatively simple control operation, and reliably avoid a situation where only a part of the contact portion for power transmission is worn. can do.

  Specific examples of the plurality of shift characteristics belonging to the same shift stage include the following two types. First, each of the plurality of shift characteristics set as the same shift stage has a gear ratio that changes as the output shaft speed increases as the input shaft speed of the continuously variable transmission increases. Set as.

  Further, in one shift characteristic among a plurality of shift characteristics set as the same shift stage, the shift when the output shaft rotation speed increases with the increase of the input shaft rotation speed of the continuously variable transmission. While the ratio is kept constant, other speed change characteristics are set such that the speed ratio changes when the output shaft speed increases as the input shaft speed of the continuously variable transmission increases. .

  Of these two types, regardless of which of the plurality of shift characteristics belonging to the same shift stage is selected in the former, for example, in a belt-type continuously variable transmission, each of the secondary and primary pulleys is effective. It is possible to realize a situation in which the input shaft rotation speed and the output shaft rotation speed change while the diameter changes, that is, the belt winding position on each pulley changes. In other words, in the case of this solution, the speed ratio line indicating the change in the output shaft speed relative to the change in the input shaft speed is expressed as a straight line that does not pass through the origin in the coordinate system regardless of the speed change characteristic. (See FIG. 4). For this reason, the shifting operation and the changing operation of the input shaft rotation speed and the output shaft rotation speed are performed while using the wide range of the belt clamping surface of the pulley substantially evenly.

  On the other hand, in the latter case, when one specific shift characteristic among a plurality of shift characteristics belonging to the same shift stage is selected, for example, in a belt type continuously variable transmission, each of the secondary and primary pulleys While the effective diameter is kept constant, that is, without changing the belt winding position around each pulley, the input shaft rotation speed and the output shaft rotation speed change. In other words, in this speed change characteristic, the speed ratio line indicating the change in the output shaft speed with respect to the change in the input shaft speed is represented as a straight line passing through the origin in the coordinate system (one in FIG. 7). The gear ratio line (see the gear ratio line located in the center in each gear group) with the portion indicated by a broken line). When other speed change characteristics are selected, the input shaft rotation speed and output are changed while the effective diameters of the secondary and primary pulleys are changed, that is, the belt winding position with respect to each pulley is changed. The shaft rotation speed will change. That is, this speed change characteristic is such that a speed ratio line indicating a change in output shaft speed with respect to a change in input shaft speed is represented as a straight line that does not pass through the origin in the coordinate system (only a solid line in FIG. 7). The gear ratio lines shown (see gear ratio lines located on both outer sides in each gear group). Thus, in this solution, the conventional power transmission mode (power transmission mode in a state where the effective diameter of each pulley is maintained constant) and the new power transmission mode (the effective diameter of each pulley is changed). In this way, a stepped speed change operation that has never been achieved can be realized.

  As the continuously variable transmission, specifically, a belt type continuously variable transmission can be applied. That is, the continuously variable transmission is configured such that an endless belt is wound around the input pulley and the output pulley, and the gear ratio can be changed by changing the effective diameter of each pulley.

  In the present invention, when a continuously variable transmission is subjected to a stepped transmission, the use frequency of each shift characteristic belonging to the same shift stage is made substantially uniform so that a contact location for power transmission can be used over a wide range. I am doing so. For this reason, it is possible to eliminate the concern that only a part of the contact portion is worn.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment demonstrates the case where this invention is applied to the belt-type continuously variable transmission (what is called CVT: Continuously Variable Transmission) for motor vehicles. In the following embodiments, a belt type continuously variable transmission mounted on an FF (front engine / front drive) vehicle will be described.

-First embodiment-
First, the first embodiment will be described. In this embodiment, as the shifting operation of the belt-type continuously variable transmission, both “automatic (automatic) shifting mode” and “manual (manual) shifting mode” are “stepped shifting (in the case of this embodiment, from the first speed). An example in which a speed change operation is performed by “stepped speed change between the seventh speed” will be described.

(Overall structure of transaxle)
First, the overall configuration of a transaxle equipped with a belt type continuously variable transmission will be described.

  FIG. 1 is a skeleton diagram of a transaxle when a belt type continuously variable transmission is applied to an FF vehicle. In FIG. 1, reference numeral 1 denotes an engine as a vehicle drive source, and the type thereof is not particularly limited. In the following description, a case where a gasoline engine is used as the engine 1 will be described for convenience.

  A transaxle 3 is provided on the output side of the engine 1. The transaxle 3 includes a transaxle housing 4 attached to the output side (side of the vehicle) of the engine 1, and the engine in the transaxle housing 4. 1 has a transaxle case 5 attached to the opening end opposite to 1 and a transaxle rear cover 6 attached to the opening end opposite to the transaxle housing 4 in the transaxle case 5 in this order. . A torque converter (T / C) 7 is provided in the transaxle housing 4, and a forward / reverse switching mechanism 8, a belt type continuously variable transmission (inside the transaxle case 5 and the transaxle rear cover 6). CVT) 9, a final reduction gear 10 having a differential mechanism, and the like are provided.

  An input shaft 11 is provided on the same axis as the crankshaft 2 inside the transaxle housing 4, and a turbine runner 13 of the torque converter 7 is attached to an end of the input shaft 11 on the engine 1 side. It has been. On the other hand, a front cover 15 is connected to the end of the crankshaft 2 via a drive plate 14, and a pump impeller 16 is connected to the front cover 15. The turbine runner 13 and the pump impeller 16 are arranged to face each other, and a stator 17 is provided inside the turbine runner 13 and the pump impeller 16. An oil pump 20 is provided between the torque converter 7 and the forward / reverse switching mechanism 8.

  As the operation of the torque converter 7, as the crankshaft 2 is rotated by driving the engine 1, the pump impeller 16 rotates via the drive plate 14 and the front cover 15, and the flow of hydraulic fluid supplied from the oil pump 20 As a result, the turbine runner 13 starts to be dragged. When the rotational speed difference between the pump impeller 16 and the turbine runner 13 is large, the stator 17 converts the flow of hydraulic fluid into a direction that assists the rotation of the pump impeller 16.

  When the vehicle speed reaches a predetermined speed after the vehicle starts, the lockup clutch 18 provided in the torque converter 7 is operated, and the power transmitted from the engine 1 to the front cover 15 is mechanically and mechanically applied to the input shaft 11. It will be transmitted directly. Further, the fluctuation of the torque transmitted from the front cover 15 to the input shaft 11 is absorbed by the damper mechanism 19.

  The forward / reverse switching mechanism 8 is provided in a power transmission path between the input shaft 11 and the belt type continuously variable transmission 9. The forward / reverse switching mechanism 8 has a double pinion type planetary gear mechanism 24. The planetary gear mechanism 24 includes a sun gear 25 provided on the input shaft 11, a ring gear 26 disposed concentrically with the sun gear 25 on the outer peripheral side of the sun gear 25, and an inner pinion gear 27 meshed with the sun gear 25. The outer pinion gear 28 meshed with the inner pinion gear 27 and the ring gear 26, the pinion gears 27, 28 are supported so as to be capable of rotating, and the pinion gears 27, 28 can be integrally revolved around the sun gear 25. And the carrier 29 held in the above. The carrier 29 is connected to a primary shaft (transmission input shaft) 30 to be described later of the belt type continuously variable transmission 9. A forward clutch CL for connecting / disconnecting a power transmission path between the carrier 29 and the input shaft 11 and a reverse brake BR for controlling rotation / fixation of the ring gear 26 are provided. By controlling the forward clutch CL and the reverse brake BR, the power transmission path can be changed to switch between forward rotation power (forward rotation direction) and reverse rotation power (reverse rotation direction).

  The belt type continuously variable transmission 9 includes a primary shaft (drive side shaft) 30 disposed on the same axis as the input shaft 11, and a secondary shaft (driven side shaft) 31 disposed in parallel to the primary shaft 30. have. The primary shaft 30 is rotatably supported by bearings 32 and 33, and the secondary shaft 31 is rotatably supported by bearings 34 and 35, respectively.

  A primary pulley (driving side pulley) 36 is provided on the primary shaft 30 side, and a secondary pulley (driven pulley) 37 is provided on the secondary shaft 31 side.

  The primary pulley 36 has a fixed sheave 38 formed integrally with the primary shaft 30 and a movable sheave 39 configured to be movable in the axial direction of the primary shaft 30. A V-shaped groove 40 is formed between the opposed surfaces of the fixed sheave 38 and the movable sheave 39.

  Further, a hydraulic actuator 41 is provided for moving the movable sheave 39 in the axial direction of the primary shaft 30 to bring the movable sheave 39 and the fixed sheave 38 closer to or away from each other. In other words, the movable sheave 39 is moved forward and backward with respect to the fixed sheave 38 by applying a predetermined hydraulic pressure to the working hydraulic chamber formed in the hydraulic actuator 41.

  On the other hand, the secondary pulley 37 similarly has a fixed sheave 42 formed integrally with the secondary shaft 31 and a movable sheave 43 configured to be movable in the axial direction of the secondary shaft 31. A V-shaped groove 44 is formed between the surfaces facing the movable sheave 43. Further, a hydraulic actuator 45 that moves the movable sheave 43 and the fixed sheave 42 closer to and away from each other by operating the movable sheave 43 in the axial direction of the secondary shaft 31 is provided. That is, the movable sheave 43 is moved forward and backward with respect to the fixed sheave 42 by applying a predetermined hydraulic pressure to a working hydraulic chamber formed in the hydraulic actuator 45.

  A belt 46 is wound around the groove 40 of the primary pulley 36 and the groove 44 of the secondary pulley 37. The belt 46 is configured as a so-called push-type metal belt having a number of metal pieces (also referred to as elements and blocks) and a plurality of steel rings (also referred to as hoops and bands). (See, for example, Japanese Patent Application Laid-Open Nos. 2000-220697 and 2002-257200).

  The belt 46 is configured such that the winding position of the pulleys 36 and 37 is changed in accordance with the forward and backward movement of the movable sheaves 39 and 43, and power transmission (torque transmission) is performed while obtaining a predetermined gear ratio. .

  A counter drive gear 47 is fixed to the secondary shaft 31 and supported by bearings 48 and 49. Further, the bearing 35 is provided on the transaxle rear cover 6 side, and a parking gear PG is provided between the bearing 35 and the secondary pulley 37.

  Further, an intermediate shaft 50 parallel to the secondary shaft 31 is disposed in a power transmission path between the counter drive gear 47 and the final reduction gear 10 with bearings 51 and 52 supported. The intermediate shaft 50 is provided with a counter driven gear 53 that meshes with the counter drive gear 47 and a final drive gear 54.

  On the other hand, the final speed reducer 10 has a hollow differential case 55 rotatably supported by bearings 56 and 57, and a final ring gear 58 that meshes with the final drive gear 54 is provided on the outer periphery of the differential case 55. A pinion shaft 59 to which two pinion gears 60 and 60 are attached is disposed inside the differential case 55. Two side gears 61 and 61 are meshed with the pinion gear 60 and are connected to wheels 63 via left and right drive shafts 62 and 62, respectively.

  Further, reference numerals 71 and 72 in the figure denote rotation speed sensors for detecting the rotation speeds of the primary pulley 36 and the secondary pulley 37, respectively.

  The hydraulic pressure generated by the oil pump 20 is controlled and supplied to the hydraulic actuator 41 of the primary pulley 36 and the hydraulic actuator 45 of the secondary pulley 37 via the hydraulic control circuit 200. Here, reference numerals 73 and 74 denote hydraulic sensors that detect control hydraulic pressures Ppri and Psec supplied to the hydraulic actuator 41 of the primary pulley 36 and the hydraulic actuator 45 of the secondary pulley 37, respectively.

  More specifically, the hydraulic oil sucked from the oil pan and discharged from the oil pump 20 is regulated by a duty-regulated pressure regulating valve and controlled as a line pressure PL. The hydraulic oil having the line pressure PL is set to the above-described control hydraulic pressure Ppri by the duty-controlled primary side pressure reducing valve and supplied to the primary side hydraulic actuator 41. Further, the hydraulic oil having the line pressure PL is similarly duty-controlled and controlled by the secondary-side pressure reducing valve to the control hydraulic pressure Psec, and is supplied to the secondary-side hydraulic actuator 45.

  1 is a CVT electronic control unit (hereinafter referred to as CVT • ECU) for controlling the transaxle 3, and 400 is an engine electronic control unit (hereinafter referred to as E / G • ECU) for controlling the engine 1. Each of which is composed of an arithmetic processing unit (CPU or MPU), a storage unit (RAM and ROM), and a microcomputer mainly including an input / output interface.

  For the CVT / ECU 300, in addition to the signals from the rotation speed sensors 71 and 72 and the hydraulic pressure sensors 73 and 74, various parameters indicating the state of the transaxle 3, such as the torque ratio of the torque converter 7 and the vehicle speed. Information such as V is input. On the other hand, the E / G • ECU 400 receives various parameters indicating the operating state of the engine 1, for example, information on the engine rotation speed, accelerator opening, throttle opening, etc. Are input to the CVT / ECU 300. In this way, the CVT / ECU 300 stores various information such as the rotational speed Np of the primary shaft 30 and the rotational speed Ns of the secondary shaft 31 by the rotational speed sensors 71 and 72, and further information such as the vehicle speed V and the accelerator opening. In order to obtain the required gear ratio γ (= Np / Ns) and the belt clamping pressure based on a map or the like that is input as a calculation result signal and obtained in advance through experiments or the like, Psec is formed. The control map stored in the CVT / ECU 300 will be described later.

  Further, a shift device 80 shown in FIG. 2 is arranged in the vicinity of the driver's seat of the vehicle according to this embodiment on which the above-described transaxle 3 is mounted. The shift device 81 is provided with a shift lever 81 so that it can be displaced. In addition, a reverse (R) position, a neutral (N) position, a drive (D) position, and a sequential (S) position are set in the shift device 80, and the driver moves the shift lever 81 to a desired shift position. Can be displaced. Each shift position of the reverse (R) position, neutral (N) position, drive (D) position, and sequential (S) position (including the following “+” position and “−” position) is detected by a shift position sensor. It has come to be.

  In a state where the shift lever 81 is operated to the “drive (D) position”, the “automatic shift mode” is set, and a shift stage is selected according to a shift map described later to perform a stepped shift operation.

  On the other hand, when the shift lever 81 is operated to the “sequential (S) position”, the “manual transmission mode” is set. Before and after the S position, a “+” position and a “−” position are provided. The “+” position is a position where the shift lever 81 is operated during a manual upshift, and the “−” position is a position where the shift lever 81 is operated during a manual downshift. When the shift lever 81 is in the S position and the shift lever 81 is operated to the “+” position or the “−” position with the S position as a neutral position, the shift stage of the belt type continuously variable transmission 9 is increased. Or down. Specifically, the gear position is increased by one step for each operation to the “+” position (for example, 1st → 2nd → ·· → 7th). On the other hand, the gear stage is lowered by one stage (for example, 7th → 5th →... → 1st) for each operation to the “−” position.

-Shift map-
Next, a shift map used for selecting a gear position in the “automatic shift mode” will be described. FIG. 3 is a shift map for stepped shift control when the belt-type continuously variable transmission 9 according to the present embodiment is set to the “automatic shift mode”.

  This shift map is a map in which a vehicle speed and an accelerator opening are used as parameters, and a plurality of areas for obtaining an appropriate gear stage are set according to the vehicle speed and the accelerator opening, and the ROM of the CVT / ECU 300 Is stored within. Each region of the shift map is partitioned by a plurality of shift lines (shift stage switching lines).

  In the shift map shown in FIG. 3, the upshift line (shift line) is indicated by a solid line, and the downshift line (shift line) is indicated by a broken line. Also, each switching direction of upshifting and downshifting is shown using numerals and arrows in the figure.

-Gear ratio line map-
Next, the rotation speed Np (input shaft rotation speed) of the primary shaft 30 and the rotation speed Ns (output shaft rotation speed) of the secondary shaft 31 when the belt-type continuously variable transmission 9 is operated at “stepped transmission”. A gear ratio line map showing the relationship will be described with reference to FIG.

  Each speed ratio line in this speed ratio line map indicates a speed change operation to another speed stage when the belt type continuously variable transmission 9 is set to a certain speed stage (speed change according to the above speed change map (FIG. 3)). The relationship between the rotational speed Np of the primary shaft 30 and the rotational speed Ns of the secondary shaft 31 at that gear position is determined until an operation or a manual shift operation by operating the shift lever 81 is performed. That is, a line that sets the relationship between the increase or decrease in the rotational speed Np of the primary shaft 30 and the increase or decrease in the rotational speed Ns of the secondary shaft 31 so as to be a constant relationship. The numbers Np and Ns change along this line.

  The belt type continuously variable transmission 9 according to the present embodiment performs a stepped transmission between the first speed and the seventh speed. As one of the features of the present embodiment, the speed ratio line map includes seven types from the first speed speed ratio line group (first speed group) to the seventh speed speed ratio line group (seventh speed group). A transmission ratio line group is set, and each transmission ratio line group includes three transmission ratio lines having different transmission characteristics.

  Hereinafter, each speed ratio line included in the speed ratio line group will be described. Here, in order to facilitate understanding, the third speed gear ratio line group and the fourth speed gear ratio line group are extracted from the seven types of gear ratio line groups.

  FIG. 5 is a gear ratio line map showing the third speed gear ratio line group and the fourth speed gear ratio line group.

  As described above, the three speed ratio lines having different speed characteristics are set in the third speed ratio line group and the fourth speed ratio line group. In these three gear ratio lines, the ratio of the increase amount of the rotation speed (output shaft rotation speed) Ns of the secondary shaft 31 to the increase amount of the rotation speed (input shaft rotation speed) Np of the primary shaft 30 is the same. In addition, even if the rotation speed Np of the primary shaft 30 is the same, the rotation speed Ns of the secondary shaft 31 is different from each other. That is, the three transmission ratio lines belonging to the same transmission ratio line group are set as parallel lines having the same inclination angle on the transmission ratio line map (see FIG. 5), and have different transmission characteristics. Have. Further, each speed ratio line in the present embodiment is set as a straight line that does not pass through the origin of the speed ratio line map of FIG.

  Here, for convenience, the three gear ratio lines constituting the third speed gear ratio line group are referred to as “3-1 gear ratio line (indicated by 3-1 in the figure)”, “3-2 gear ratio line”. (Shown as 3-2 in the figure) "," 3-3 speed ratio line (shown as 3-3 in the figure) ", and the three speed ratio lines constituting the fourth speed ratio line group, “4-1th gear ratio line (indicated by 4-1 in the figure)”, “4-2th gear ratio line (indicated by 4-2 in the figure)”, “4-3 speed ratio line (indicated by 4 in the figure) -3)) ".

  The relationship among the three gear ratio lines constituting the third speed gear ratio line group in the one shown in FIG. 5 is as follows. First, the rotation speed Ns of the secondary shaft 31 increases with respect to the increase amount of the rotation speed Np of the primary shaft 30. The quantity ratios are the same. And even if the rotation speed Np of the primary shaft 30 is the same, the rotation speed Ns of the secondary shaft 31 is “the 3rd-1 gear ratio line”, “the 3-2 gear ratio line”, “the 3rd gear ratio line”. It is set so as to increase in the order of “3 gear ratio line”. For example, the relationship is set so as to increase by about 3 km / h in terms of vehicle speed. The same applies to other gear ratio line groups.

  Since the belt-type continuously variable transmission 9 is controlled according to the gear ratio line map in which each gear ratio line group is set in this way, the speed change can be performed regardless of which gear ratio line is controlled. The ratio of the increase amount of the rotation speed Ns of the secondary shaft 31 to the increase amount of the rotation speed Np of the primary shaft 30 is maintained constant while the ratio is gradually changed. That is, when the effective diameters of the primary pulley 36 and the secondary pulley 37 are changed, the rotation position Np of the primary shaft 30 and the rotation speed Ns of the secondary shaft 31 are changed while the winding position of the belt 46 around the pulleys 36 and 37 is changed. Will change.

  Specifically, in the case of the gear ratio line map shown in FIG. 4, regardless of which gear ratio line is selected, each pulley 36, as the rotational speed Np of the primary shaft 30 increases. The effective diameter of 37 gradually changes to the side where the gear ratio increases. That is, as the rotational speed Np of the primary shaft 30 increases, the winding radius of the belt 46 around the primary pulley 36 gradually decreases, and the winding radius of the belt 46 relative to the secondary pulley 37 gradually increases, thereby increasing the linear shape. It follows the transmission ratio line. This is because each speed ratio line is a straight line that does not pass through the origin of the speed ratio line map of FIG. 4, and on the horizontal axis (coordinate axis of the output shaft rotation speed) in FIG. This is because it is set as a line passing through. Therefore, the speed ratio line is a straight line that does not pass through the origin of the speed ratio line map of FIG. 4 and passes on the left side (negative side) of the origin on the horizontal axis (coordinate axis of the output shaft rotational speed) in FIG. When set as a line, as the rotation speed Np of the primary shaft 30 increases, the effective diameters of the pulleys 36 and 37 gradually change toward the side where the gear ratio becomes smaller. . That is, as the rotational speed Np of the primary shaft 30 increases, the winding radius of the belt 46 with respect to the primary pulley 36 gradually increases, and the winding radius of the belt 46 with respect to the secondary pulley 37 gradually decreases, so that a linear shape is obtained. Along the gear ratio line.

  Since each gear ratio line is set in this manner, for example, when the third speed is selected and the vehicle accelerates, any gear ratio line in the third speed gear ratio line group is selected. Even if (any of the above-mentioned “3-1 gear ratio line”, “3-2 gear ratio line”, “3-3 gear ratio line” is selected), the rotational speed Np of the primary shaft 30 Since the ratio of the increase amount of the rotation speed Ns of the secondary shaft 31 to the increase amount (the inclination angle of the speed ratio line in FIG. 5) is the same and constant, the vehicle is accelerated with the same acceleration. Become. Further, as described above, the ratio of the increase amount of the rotation speed Ns of the secondary shaft 31 to the increase amount of the rotation speed Np of the primary shaft 30 is gradually changed regardless of which speed ratio line is selected. It will be kept constant.

  In the above description, only the third speed gear ratio line group and the fourth speed gear ratio line group have been described, but other speed ratio line groups (first speed gear ratio line group, second speed gear ratio line group, The same applies to the fifth speed gear ratio line group to the seventh speed gear ratio line group.

  Another feature of the present embodiment is that any of the three gear ratio lines constituting the gear ratio line group of the gear stage is selected during the gear shift operation to the gear stage selected during the stepped gear shift operation. The speed ratio line is selected, that is, the speed ratio line is changed according to which speed ratio line is set. Specifically, the one with the lowest use frequency (number of uses) of each speed ratio line in each speed ratio line group is used for the current speed change operation. More specifically, the three gear ratio lines constituting the gear ratio line group are used in order each time the gear ratio is set, so that the number of uses of each gear ratio line is substantially matched. The shift operation is controlled (shift operation by shift characteristic selection performed by the shift characteristic selecting means).

  Hereinafter, the selection operation of the gear ratio line will be described with reference to the flowchart of FIG. The routine (stepped gear change execution routine) shown in FIG. 6 is executed every several milliseconds, for example.

  First, in step ST1, it is determined whether or not it is time to execute a shift operation. For example, when the “automatic shift mode” is set, the running state of the vehicle changes while the shift control is performed according to the shift map for stepped shift control (FIG. 3). If the change is over the upshift line or the change is over the downshift line, Yes is determined in step ST1. On the other hand, when the “manual shift mode” is set, the shift lever 81 is operated to the “sequential (S) position”, the operation to the “+” position (manual upshift), “ If an operation to a “−” position (manual downshift) is performed, a Yes determination is made in step ST1.

  If it is not the timing at which the speed change operation is executed and the determination in step ST1 is No, this routine ends.

  On the other hand, it is the timing at which the shift operation is executed, and if the determination in step ST1 is Yes, the process proceeds to step ST2. In this step ST2, information on the number of times of selection of the gear stage to be shifted (the gear position after the shift operation is performed) is read from the RAM of the CVT / ECU 300. Specifically, the gear stage Ni (i is any one of 1 to 7) and the number-of-selections information (j) at the gear stage, that is, the information on the number of selections (j) of the gear stage (Ni). To get.

  Then, in step ST3, it is determined whether or not the number of selections (j) at this gear position (Ni) is “1”. This determination operation determines whether or not it is the first shift after the number of times information (j) of the gear to be shifted is reset (after being reset to “1” in step ST11 described later). To do. As will be described later, the number of times of selection (j) repeats counting between “1” and “3” every time the gear position (Ni) is selected.

  If it is determined in step ST3 that the number-of-times information (j) is “1”, the process proceeds to step ST4 to set the first gear ratio line. The first gear ratio line is the “3-1 gear ratio line” in the above-described third speed gear ratio line group, and the “first gear ratio line” in the fourth speed gear ratio line group. "4-1 transmission ratio line". The same applies to the other gear ratio line groups.

  On the other hand, if the number information (j) is not “1” but No is determined in step ST3, the process proceeds to step ST5, and whether or not the number of selections (j) at this gear position (Ni) is “2”. Determine. This determination operation determines whether or not it is the second shift after the shift stage number information (j) to be shifted is reset (after being reset to “1” in step ST11 described later). To do.

  If it is determined in step ST5 that the number-of-times information (j) is “2”, the process proceeds to step ST6 to set the second gear ratio line. The second gear ratio line is the “third to second gear ratio line” in the third speed gear ratio line group described above, and the “second gear ratio line” in the fourth speed gear ratio line group. 4-2 gear ratio line ". The same applies to the other gear ratio line groups.

  If the number information (j) is not “2” but No is determined in step ST5, the process proceeds to step ST7, and it is determined whether or not the number of selections (j) in this gear (Ni) is “3”. To do. This determination operation determines whether or not it is the third shift after the number of times information (j) of the gear stage to be shifted is reset (after being reset to “1” in step ST11 described later). To do.

  If it is determined in step ST7 that the number-of-times information (j) is “3”, the process proceeds to step ST8 to set the third gear ratio line. The third gear ratio line is the “third to third gear ratio line” in the third speed gear ratio line group described above, and the “third gear ratio line” in the fourth speed gear ratio line group. 4-3 gear ratio line ". The same applies to the other gear ratio line groups.

  After the transmission gear ratio line (first transmission gear ratio line, second transmission gear ratio line or third transmission gear ratio line) is selected as described above, the process proceeds to step ST9, and the selected transmission gear ratio line is transferred to step ST9. A speed change operation is performed. For example, when a shift-up instruction is given during traveling at the second speed and the first speed ratio line of the third speed speed ratio line group is selected (when determined Yes in step ST3), the above “ The gear shift operation toward the “3-1 gear ratio line” is executed. Similarly, for example, when a downshift instruction is given during traveling at the fourth speed and the third speed ratio line of the third speed ratio line group is selected (when YES is determined in step ST7). Then, the gear shift operation toward the “3-3rd gear ratio line” is executed.

  After the speed change operation to the speed ratio line selected as described above is executed, the process proceeds to step ST10, the selection number information (j) is counted up (j ← j + 1), and the process returns. For this reason, when there is an instruction to shift to the same gear stage next time, a speed ratio line different from the previous speed ratio line is selected and the speed change operation is executed.

  On the other hand, if the number of times information (j) is not “1”, “2”, or “3” and a NO determination is made in step ST7, the process proceeds to step ST11, where the number of times selected (j) ) Is reset to “1”. That is, the next time when there is a shift instruction to the same shift stage, the first shift ratio line in the shift ratio line group is selected and the shift operation is executed.

  The above operation is repeated. In other words, the gear ratio line is selected and the speed change operation is executed while the number of times information (j) is repeated in the order of “1”, “2”, and “3”. For this reason, the three speed ratio lines constituting each speed ratio line group are used in order every time the speed ratio is set, and the speed change operation is performed so that the number of times of use of each speed ratio line is substantially matched. Can be controlled.

  For example, in a situation where the vehicle accelerates while the gear stage of the belt type continuously variable transmission 9 is alternately switched between the third speed and the fourth speed, as shown by a broken line arrow in FIG. "3-1 gear ratio line"-> "4-1 gear ratio line"-> "3-2 gear ratio line"-> "4-2 gear ratio line"-> "3-3 gear ratio line" The speed change operation is executed while the speed ratio lines are selected in the order of “4-3rd speed ratio line” → “3-1th speed ratio line”.

  As a result, it is possible to make the frequency of use of each gear ratio line belonging to the same gear stage substantially uniform, and power transmission is performed while using the belt clamping surfaces of the primary pulley 36 and the secondary pulley 37 over a wide range. In other words, it is possible to avoid a situation in which only a part is worn.

-Second Embodiment-
Next, a second embodiment will be described. The three gear ratio lines constituting each gear ratio line group in the first embodiment described above are all set as straight lines that do not pass through the origin of the gear ratio line map. In this embodiment, instead of this, one of the three gear ratio lines constituting each gear ratio line group (a total of seven gear ratio lines) is a straight line passing through the origin of the gear ratio line map. Is set as

  FIG. 7 shows a gear ratio line map in the present embodiment. As shown in FIG. 7, in the gear ratio line map in this embodiment, the center gear ratio line (second gear ratio line) among the three gear ratio lines constituting each gear ratio line group is the gear ratio. It is set as a straight line passing through the origin of the line map (see the gear ratio line partially shown in FIG. 7), and the other gear ratio lines (first gear ratio line and third gear ratio line) are: It is set as a straight line that is parallel to the transmission ratio line passing through the origin and does not pass through the origin of the transmission ratio line map.

  That is, when the second gear ratio line is selected, in the belt-type continuously variable transmission 9, the effective diameters of the secondary and primary pulleys 36 and 37 are maintained constant, that is, each pulley 36 , 37, the rotation speed Np of the primary shaft 30 and the rotation speed Ns of the secondary shaft 31 change without changing the position where the belt 46 is wound around.

  When other speed change characteristics (first speed ratio line and third speed ratio line) are selected, as in the case of the first embodiment, the secondary and primary pulleys 36, The rotational speed Np of the primary shaft 30 and the rotational speed Ns of the secondary shaft 31 change while the effective diameter of the belt 37 changes, that is, the position where the belt 46 is wound around the pulleys 36 and 37 changes. .

  Thus, in this embodiment, the conventional power transmission mode (power transmission mode in a state where the effective diameter of each pulley 36, 37 is maintained constant) and the new power transmission mode (of each pulley 36, 37). A stepped speed change operation using the power transmission mode in a state where the effective diameter changes can be realized.

  In the present embodiment, the central transmission ratio line (second transmission ratio line) among the three transmission ratio lines constituting each transmission ratio line group is a straight line passing through the origin of the transmission ratio line map. It was set, but it is not limited to this. For example, the first speed ratio line is set to be a straight line passing through the origin of the speed ratio line map, and the other speed ratio line is set to be a straight line not passing through the origin of the speed ratio line map, or the third speed ratio line is set. May be set to be a straight line passing through the origin of the transmission ratio line map, and the other transmission ratio line may be set to be a straight line not passing through the origin of the transmission ratio line map.

-Third embodiment-
Next, a third embodiment will be described. In the first embodiment and the second embodiment described above, both the “automatic transmission mode” and the “manual transmission mode” are the speed change operations of the belt-type continuously variable transmission 9 by “stepped speed change”. Was described as an example. In the present embodiment, instead of this, in the “automatic transmission mode”, the transmission operation is performed by “stepless transmission”, and in the “manual transmission mode”, the transmission operation is performed by “stepped transmission”. The “stepped shift” in the “manual shift mode” is performed in the same manner as in each of the above-described embodiments. Therefore, here, only the “stepless shift” performed in the “automatic shift mode” is simply described. explain.

  This “automatic shift mode” is a mode in which the gear ratio γ is automatically and continuously changed according to the driving state of the vehicle when the shift lever 81 is operated to the “drive (D) position”. As shown in FIG. 8, the target rotational speed NINT on the input side is determined from an automatic shift map determined in advance using the accelerator operation amount θACC representing the driver's required output amount and the vehicle speed V (corresponding to the output shaft rotational speed) as parameters. And the shift control of the belt-type continuously variable transmission 9 according to the deviation, specifically, the electromagnetic switching of the hydraulic control circuit 200, so that the actual input shaft rotational speed NIN matches the target rotational speed NINT. Feedback control of the valve and the like is performed to control the supply and discharge of hydraulic oil to and from the hydraulic actuator 41 of the primary pulley 36. The automatic shift map shown in FIG. 8 corresponds to a shift condition, and a target rotational speed NINT that sets a larger speed ratio γ as the vehicle speed V is smaller and the accelerator operation amount θACC is larger is set. Further, since the vehicle speed V corresponds to the output shaft rotational speed, the target rotational speed NINT, which is the target value of the input shaft rotational speed NIN, corresponds to the target speed ratio, and the minimum speed ratio γmin and the maximum of the belt type continuously variable transmission 9 are maximized. It is determined within the range of the gear ratio γmax. The automatic shift map is stored in advance in the CVT / ECU 300ROM.

  In the present embodiment, the speed change operation is performed by “stepped speed change” only in the “manual speed change mode”, and as a result, the primary pulley 36 and the secondary pulley 37 are changed in the same manner as in the first and second embodiments described above. It is possible to avoid a situation in which power is transmitted while using the belt clamping surface over a wide range and only a part of the belt is worn. The speed ratio line map used in the “stepped transmission” in the third embodiment may be that of the first embodiment (FIG. 4) or that of the second embodiment (FIG. 7). ).

-Other embodiments-
In each of the embodiments described above, the case where the present invention is applied to the belt-type continuously variable transmission 9 capable of the seven-speed step-change between the first speed to the seventh speed has been described. The present invention is not limited to this, and can also be applied to a belt-type continuously variable transmission capable of a step-variable transmission of 6 speeds or less and a belt-type continuously variable transmission capable of a step-change of 8 speeds or more. . Further, the continuously variable transmission is not limited to the belt type, and the present invention can be applied to other methods, for example, a toroidal type continuously variable transmission.

  In each of the above-described embodiments, three speed ratio lines having different speed characteristics are set in each speed ratio line group. The present invention is not limited to this. For each gear ratio line group, two gear ratio lines with different gear shifting characteristics are set, or four or more gear ratio lines with different gear shifting characteristics are set. It may be. Further, the number of transmission ratio lines set in each transmission ratio line group need not necessarily be the same. For example, in a case where a seven-speed shift is performed, two gear ratio lines are used in the first gear ratio line group and the second gear ratio line group, and three gear ratios are used in the third gear ratio line group and the fourth gear ratio line group. In the fifth gear ratio line group to the seventh gear ratio line group, various settings are possible, such as setting four gear ratio lines.

  Further, in each of the above-described embodiments, the number of times of selection (the number of times of use) coincides with the frequency of use of each speed ratio line in each speed ratio line group. The present invention is not limited to this, and the usage time of each gear ratio line in each gear ratio line group (the time during which the vehicle has traveled in each gear ratio line) is measured, and this usage time becomes equal. In this way, the gear ratio line selection operation may be performed.

  Further, in each of the above-described embodiments, the shift operation in the “manual shift mode” is performed by the shift lever 81 provided in the center console as the shift device 80. The present invention can also be applied to a device in which a shift operation in the “manual shift mode” is performed by a paddle shift type shift device provided with the above.

It is a skeleton figure which shows the transaxle in embodiment. It is a perspective view which shows a shift apparatus. It is a figure which shows the step map for stepped transmission control used by "automatic transmission mode" of 1st Embodiment. It is a figure which shows the gear ratio line map used when performing the stepped transmission of 1st Embodiment. It is a figure which shows the 3rd speed gear ratio line group and the 4th speed gear ratio line group on the gear ratio line map in 1st Embodiment. It is a flowchart figure which shows the procedure of selection operation | movement of the gear ratio line in 1st Embodiment. It is a figure which shows the gear ratio line map used when performing the stepped transmission of 2nd Embodiment. It is a figure which shows the automatic transmission map used when performing continuously variable transmission of 3rd Embodiment. It is a figure which shows an example of the change of each rotation speed of input / output at the time of performing a continuously variable transmission in a prior art example. It is a figure which shows the gear ratio line map used when performing stepped transmission in a prior art example.

Explanation of symbols

1 Engine (drive source)
9 Belt type continuously variable transmission (continuously variable transmission)
30 Primary shaft (input shaft)
31 Secondary shaft (output shaft)

Claims (5)

In a continuously variable transmission control device for a continuously variable transmission in which a continuously variable transmission configured to continuously change the output rotation of a drive source is shifted between a plurality of preset gears. ,
The ratio of the increase amount of the output shaft rotation speed to the increase amount of the input shaft rotation speed of the continuously variable transmission is substantially the same, and the output shaft rotation speeds are different from each other even when the input shaft rotation speed is the same. Are set as the same gear position,
A shift characteristic selection for performing a shift operation to the shift stage by selecting the shift characteristic so that the frequency of use of each of the shift characteristics is substantially equal during the shift operation to the shift stage having the plurality of shift characteristics. A step-variable transmission control apparatus for a continuously variable transmission, characterized by comprising: In the stepped transmission control device for a continuously variable transmission according to claim 1,
The shift characteristic selection means sequentially selects the plurality of shift characteristics each time a shift operation to a shift stage having a plurality of shift characteristics is performed, and performs the shift operation so as to use the selected shift characteristics. A continuously variable transmission control device for a continuously variable transmission, characterized by being configured to execute. In the stepped transmission control device for a continuously variable transmission according to claim 1 or 2,
Each of the plurality of shift characteristics set as the same shift stage has a gear ratio that changes as the output shaft speed increases as the input shaft speed of the continuously variable transmission increases. A continuously variable transmission control device for a continuously variable transmission. In the stepped transmission control device for a continuously variable transmission according to claim 1 or 2,
One of the plurality of shift characteristics set as the same shift stage has a constant gear ratio when the output shaft speed increases as the input shaft speed of the continuously variable transmission increases. On the other hand, the other speed change characteristic is characterized in that the speed change ratio when the output shaft speed increases with the increase of the input shaft speed of the continuously variable transmission changes. A stepped shift control device for a stepped transmission. In the continuously variable transmission control device for a continuously variable transmission according to any one of claims 1 to 4,
The continuously variable transmission is a belt type continuously variable transmission in which an endless belt is wound around an input pulley and an output pulley, and the gear ratio can be changed by changing the effective diameter of each pulley. A continuously variable transmission control device for a continuously variable transmission.

Images