JP2007315429A - Control device for continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a continuously variable transmission capable of preventing the uneven wear of a variable pulley when a driver uses a stepped speed change mode and not giving the sense of incongruity on operation. <P>SOLUTION: The control device for a continuously variable transmission capable of selecting one of stepless speed change mode control and stepped speed change mode control is provided with a use frequency information acquisition means acquiring the use frequency of a selected speed change step when the stepped speed change mode is selected, a condition determination means determining whether a use condition exceeds a predetermined condition or not based on use frequency information acquired by the use frequency information acquisition means, a changed speed change ratio establishing means establishing a changed speed change ratio which is different from a speed change ratio corresponding to a selected speed change step position and makes a ratio of the change of engine speed same as the change of vehicle speed in a speed change ratio corresponding to the selected speed change step position when the condition determination means determines that the predetermined condition is satisfied, and a speed change ratio control means controlling a speed change ratio of the continuously variable transmission consistent with the changed speed change ratio established by the changed speed change ratio establishing means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a continuously variable transmission control device, and more particularly to a continuously variable transmission control device capable of switching between a continuously variable transmission mode and a stepped transmission mode (manual mode).

  2. Description of the Related Art Conventionally, there is known a control device for a continuously variable transmission that continuously changes the number of revolutions of an engine and transmits it to a drive wheel, and has a switch that manually switches between a continuously variable transmission mode and a stepped transmission mode. It has been. For example, see Patent Document 1.

  This Patent Document 1 discloses a continuously variable transmission having mode selection means for manually selecting one of a continuously variable transmission mode and a stepped transmission mode, and the continuously variable transmission mode is selected by the mode selection means. In this case, the transmission ratio of the continuously variable transmission is controlled so that the engine rotation speed matches the target rotation speed. On the other hand, when the stepped speed change mode is selected by the mode selection means, the speed change ratio is used discretely, and one of the discrete speed change ratios is selected as a target value according to the traveling state, and the selected discrete speed change mode is selected. The gear ratio of the continuously variable transmission is controlled by the gear ratio control means so as to coincide with the gear ratio.

  In the continuously variable transmission mode, in order to drive the vehicle along the minimum fuel consumption rate line, the gear ratio should be set so that the required driving force determined by the accelerator opening and vehicle speed at that time can be extracted most efficiently. Is controlled steplessly. In the stepped speed change mode, the gear ratio is discretely selected and fixed in the same manner as a normal stepped (automatic) transmission. Therefore, since the engine speed basically changes corresponding to the vehicle speed within the selected discrete gear ratio, for example, even when the accelerator pedal is frequently operated, such as during a traffic jam, the engine speed is It does not fluctuate significantly, and during acceleration, the engine speed increases as the vehicle speed increases, so driving with less discomfort can be achieved.

  However, in the one disclosed in Patent Document 1, when the driver continues to use the stepped speed change mode, only a specific portion of the belt contact surface of the variable pulley of the belt type continuously variable transmission, that is, the contact raceway surface is detected. As a result, the variable pulley is subjected to uneven wear, and as a result, there is a problem in that belt slip occurs at the time of shifting and the durability of the belt decreases.

  Therefore, in order to solve such a problem, in Patent Document 2, when the stepped transmission mode is selected by the mode selection unit, the transmission ratio is used discretely, and any one of the discrete transmission modes is selected according to the traveling state. In a continuously variable transmission control device having a gear ratio control means for selecting a gear ratio as a target value and controlling a gear ratio of the continuously variable transmission so as to coincide with the selected discrete gear ratio, a stepped transmission mode Discloses a control device for a continuously variable transmission comprising discrete gear ratio changing means for automatically changing a discrete gear ratio, which is a target value of the gear ratio control means, based on a predetermined determination result. Has been.

JP-A 63-145138 Japanese Patent Laid-Open No. 10-30715

  Here, in the continuously variable transmission control device disclosed in Patent Document 2, when the stepped transmission mode is selected, the discrete transmission ratio that is the target value of the transmission ratio control means is automatically changed as appropriate. Therefore, only a portion of the variable pulley related to a specific gear ratio is not used, and uneven wear of the pulley can be prevented or suppressed. However, when the stepped transmission mode is selected, the discrete transmission ratio, which is the target value of the transmission ratio control means, is automatically changed as appropriate, so the transmission ratio may be different before and after this change. . As a result, for example, even if the vehicle is traveling at a gear ratio equivalent to the third speed, the gear ratio can be changed to a gear ratio equivalent to the fourth speed by appropriately changing the discrete gear ratio. The engine output shaft torque may be insufficient during driving on the road, and the increase in engine speed may slow down.In such a case, the expected acceleration of the vehicle cannot be obtained, causing the driver to feel uncomfortable. there were.

  Therefore, the present invention has been made to solve such a conventional problem, and prevents uneven wear of the variable pulley when the driver uses the stepped transmission mode, and causes an uncomfortable feeling in driving. It is an object of the present invention to provide a control device for a continuously variable transmission without any problem.

  A control device for a continuously variable transmission according to an embodiment of the present invention that solves the above problems is a control device for a continuously variable transmission that can select either one of a continuously variable transmission mode control or a stepped transmission mode control. When the stepped transmission mode is selected, a usage amount information acquisition unit that acquires usage amount information of the selected gear stage, and a usage status based on the usage amount information obtained by the usage amount information acquisition unit A condition determining means for determining whether or not a predetermined condition is exceeded, and a change gear ratio different from the gear ratio corresponding to the selected gear position when the condition determining means determines that the predetermined condition is satisfied. The change gear ratio setting means for setting the change gear ratio at which the ratio of the change in the engine speed to the change in the vehicle speed in the gear ratio corresponding to the selected gear stage is the same, and the change gear ratio setting means Characterized in that it and a transmission ratio control means for controlling the transmission ratio of the continuously variable transmission so as to coincide with the change gear ratio.

  Here, the change gear ratio setting means overlaps the contact track surface between the belt and the pulley at the gear ratio corresponding to the selected gear position, and the contact surface between the belt and the pulley at the set change gear ratio. It is preferable to set the change gear ratio so as not to occur.

  Further, the contact raceway surface between the belt and the pulley is preferably a contact raceway surface in a pulley having a relatively small winding radius.

  According to the control device for a continuously variable transmission according to one aspect of the present invention, when the stepped transmission mode is selected, the selected gear stage is selected based on the usage amount information obtained by the usage amount information acquisition unit. When it is determined by the condition determining means that the usage state of the vehicle does not exceed the predetermined condition, the transmission ratio is fixedly controlled to the gear ratio corresponding to the selected gear position. Therefore, in this state, the engine rotation speed basically changes in correspondence with the vehicle speed. Therefore, at the time of acceleration, the engine rotation speed increases with the increase of the vehicle speed, and the operation with less uncomfortable feeling can be performed. On the other hand, when the condition determining means determines that the usage status of the selected gear exceeds the predetermined condition based on the usage information obtained by the usage information acquiring means, the change gear ratio setting means selects The change gear ratio is different from the gear ratio corresponding to the selected gear speed, and the change gear ratio corresponding to the selected gear speed is set to the change gear ratio at which the ratio of the engine speed change to the vehicle speed change is the same. The speed ratio of the continuously variable transmission is controlled by the speed ratio control means so as to coincide with the set change speed ratio. Therefore, only the contact raceway surface, which is a part related to a specific gear ratio of the variable pulley, is not used, and uneven wear of the pulley is prevented, and the engine speed increases as the vehicle speed increases. You can drive less.

  Here, the change gear ratio setting means does not overlap the contact track surface between the belt and the pulley at the gear ratio corresponding to the selected gear position, and the contact surface between the belt and the pulley at the set change gear ratio. According to the configuration in which the changed gear ratio is set as described above, uneven wear on the contact raceway surface between the belt and the pulley at the gear ratio corresponding to the selected gear stage can be suppressed.

  Furthermore, according to the configuration in which the contact raceway surface between the belt and the pulley is a contact raceway surface in the pulley having a relatively small winding radius, uneven wear on the contact raceway surface having a large surface pressure is surely prevented. In addition, the amount of change from the gear ratio corresponding to the selected gear position can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing an outline of a control device for a belt type continuously variable transmission to which the present invention is applied. In FIG. 1, this belt-type continuously variable transmission 10 is of a horizontal type and is preferably employed in an FF (front engine / front drive) type vehicle, and is an engine as an internal combustion engine used as a driving power source. 12 is provided. The output of the engine 12 is transmitted from the torque converter 14 to the differential gear device 22 via the forward / reverse switching device 16, the belt-type continuously variable transmission mechanism (CVT) 18, and the reduction gear mechanism 20, and the left and right drive wheels 24L, 24R. Distributed to.

  The engine 12 includes an electronically controlled throttle valve 30 that electrically adjusts the amount of intake air, and is electronically controlled by an electronic control unit (ECU) 100 in accordance with an accelerator operation amount that represents a driver's required output amount. By performing engine output control such as opening / closing control of the throttle valve 30 and fuel injection control, the output of the engine 12 is controlled to increase or decrease. Further, the engine 12 is provided with an engine speed sensor 32 for detecting the engine speed Ne based on a signal from an ignition circuit or the like.

  The torque converter 14 includes a pump impeller 14p connected to the crankshaft of the engine 12 and a turbine runner 14t connected to the forward / reverse switching device 16 via the turbine shaft 34, and transmits power via a fluid. It is like that. Further, a lock-up clutch 26 is provided between the pump impeller 14p and the turbine runner 14t so that they can be integrally connected and integrally rotated. The pump impeller 14p has a mechanical oil pump 28 for generating a hydraulic pressure for controlling the shift of the belt-type continuously variable transmission mechanism 18, generating a belt clamping pressure, or supplying lubricating oil to each part. Is provided.

  The forward / reverse switching device 16 is constituted by a double pinion type planetary gear device, the turbine shaft 34 of the torque converter 14 is connected to the sun gear 16s, and the input shaft 36 of the belt type continuously variable transmission mechanism 18 is connected to the carrier 16c. It is connected. Then, when the direct coupling clutch 38 disposed between the carrier 16c and the sun gear 16s is engaged, the forward / reverse switching device 16 is rotated integrally, and the turbine shaft 34 is directly coupled to the input shaft 36. The driving force is transmitted to the driving wheels 24R and 24L. On the other hand, when the reaction force brake 40 disposed between the ring gear 16r and the housing is engaged and the direct coupling clutch 38 is released, the input shaft 36 is rotated in the reverse direction with respect to the turbine shaft 34 to move backward. The driving force in the direction is transmitted to the drive wheels 24R and 24L. When both the direct coupling clutch 38 and the reaction force brake 40 are released, the power transmission between the engine 12 and the belt-type continuously variable transmission mechanism 18 is cut off, and a neutral state is obtained. Each of the direct coupling clutch 38 and the reaction force brake 40 is a hydraulic friction engagement device, and corresponds to an intermittent device capable of interrupting power transmission between the engine 12 and the belt type continuously variable transmission mechanism 18.

  The belt type continuously variable transmission mechanism 18 includes a primary variable pulley 42 provided on the input shaft 36 and having a variable V groove width, a primary variable pulley 42 provided on the output shaft 44 and having a variable V groove width, and the like. The transmission belt 48 is wound around the variable pulleys 42 and 46, and power is transmitted through a frictional force between the variable pulleys 42 and 46 and the transmission belt 48. The variable pulleys 42 and 46 are configured to include hydraulic cylinders as actuators that change the V-groove width. By appropriately controlling the hydraulic pressures of the hydraulic cylinders of both the variable pulleys 42 and 46, both the variable pulleys 42, The width of the V-groove 46 is changed, the winding diameter (effective diameter) of the transmission belt 48 is changed, and the gear ratio γ (= input shaft rotational speed Nin / output shaft rotational speed Nout) is continuously changed.

  In the vicinity of the primary variable pulley 42 and the secondary variable pulley 46 of the belt type continuously variable transmission mechanism 18, an input shaft rotational speed sensor 60 and an output shaft for detecting rotational speeds of the input shaft 36 and the output shaft 44, respectively. A rotation speed sensor 62 is provided. The rotation speed Nout of the output shaft 44 obtained from the output shaft rotation speed sensor 62 is converted and used as a vehicle speed V described later.

  Further, a shift lever mechanism 64 provided in the vicinity of the driver's seat in the passenger compartment has a shift for detecting operation positions such as P (parking), R (reverse), N (neutral), and D (forward). A position sensor is provided. The stepless speed change mode and the stepped speed change mode are manually selected and operated, and the operation is performed when an arbitrary speed change (speed ratio) is selected by the shift lever mechanism 64 in the stepped speed change mode. The selection switch is provided.

  Signals from the various sensors and switches described above are sent to the ECU 100, and as is well known, the hydraulic pressures of the hydraulic cylinders of the primary side variable pulley 42 and the secondary side variable pulley 46 are controlled, whereby both variable pulleys 42, 46 are controlled. , The winding diameter (effective diameter) of the transmission belt 48 is changed, and the speed ratio γ is changed continuously or discretely.

  Here, the continuously variable transmission mode is a belt-type continuously variable speed so that the target input shaft rotational speed determined to operate the engine 12 on, for example, the minimum fuel consumption rate curve and the actual input shaft rotational speed coincide with each other. This is a mode for continuously controlling the speed ratio of the speed change mechanism 18. On the other hand, the stepped transmission mode is a belt-type continuously variable transmission mechanism 18 that determines a transmission gear ratio corresponding to the selected transmission gear and sets the transmission gear ratio to be the same as the shift control in the conventional automatic transmission. This is a mode for fixedly controlling the transmission ratio.

  Hereinafter, one form of control of the belt-type continuously variable transmission mechanism 18 in the continuously variable transmission mode and the stepped transmission mode (hereinafter referred to as manual mode) according to the present embodiment will be described. The main control of the belt type continuously variable transmission mechanism 18 in the present embodiment is executed in accordance with a control routine shown in the flowchart of FIG. This control is executed at a predetermined cycle.

  In step 201 of the flowchart of FIG. 2, it is determined which of the continuously variable transmission mode and the manual mode is selected based on a signal from the selection switch. If it is determined in step S201 that the continuously variable transmission mode is selected, the process proceeds to the next step S202, and a normal continuously variable transmission control process is performed. That is, for example, based on the actual throttle valve opening, or based on the actual throttle valve opening and the vehicle speed, the target input shaft rotation speed is determined from the continuously variable transmission mode map, and this and the actual input shaft rotation Based on the speed Nin, control is performed to achieve a desired gear ratio.

  On the other hand, if it is determined in step S201 that the manual mode is selected, the process proceeds to step S203, where the usage amount information at the speed n selected in the manual mode is acquired, and the acquired usage amount is acquired. Based on the information, it is determined whether or not the usage status exceeds a predetermined condition.

  Here, the usage amount information is, for example, cumulative usage time information at a speed ratio γn corresponding to the speed n selected in the stepped speed change mode, and the continuously variable transmission 10 is mounted on the vehicle. The accumulated usage time at the gear ratio γn corresponding to the gear stage n since the start of use. The accumulated usage time is accumulated for each selected shift speed, and is stored and stored in a memory in the ECU 100 as the accumulated usage time for each shift speed. Whether or not the usage condition exceeds a predetermined condition is determined, for example, by the wear (unevenness of the contact raceway surface on the cone surface forming the V groove of the two variable pulleys 42 and 46 around which the transmission belt 48 is wound. It is determined by whether the (wear) state is within an allowable range. The predetermined condition can be set in consideration of abrasion resistance depending on materials used for the variable pulleys 42 and 46 and the transmission belt 48.

  Therefore, when it is determined in step S203 that the usage status does not exceed the predetermined condition, that is, it is determined that the accumulated usage time at the gear ratio γn corresponding to the selected gear stage n does not exceed the allowable usage time. Then, the gear ratio changing control described later is performed so that the gear ratio γn corresponding to the selected gear stage n is obtained.

  Further, when it is determined in step S203 that the usage status exceeds a predetermined condition, that is, it is determined that the accumulated usage time at the speed ratio γn corresponding to the selected gear stage n exceeds the allowable usage time, step S205. Then, it is determined whether or not the selected shift stage is the same n stage in the previous routine cycle. Here, when the selected gear stage is the same n stage as the previous routine cycle, the process proceeds to step S204, and as described above, the gear ratio γn corresponding to the selected gear stage n is obtained. The gear ratio is controlled. This is because the manual mode is selected in a state where the usage condition does not exceed the predetermined condition, and the gear ratio γn corresponding to the selected gear stage n is changed accordingly (step S204), but the manual mode is continuing. In order to avoid this situation, when the control in step S205, which will be described later, is performed when the usage situation exceeds a predetermined condition, an unintended change in the gear ratio occurs and the driver feels uncomfortable. It is. As a result, once the manual mode is selected and changed to the gear ratio γn corresponding to the selected gear stage n, the operation with the gear ratio γn continues unless the manual mode is canceled. Is done. In this way, in order to prevent the operation with the gear ratio γn from being continued unless the manual mode is released by the driver, for example, the stepless speed change is performed when the accelerator pedal is released. You may make it return to mode.

  On the other hand, in step S205, when the selected gear stage is not the same n stage as the previous routine cycle, that is, the gear stage n is selected first by selecting the manual mode, or the gear stage n from another gear stage is selected. In the case of the first routine cycle when the accumulated usage time at the gear ratio γn corresponding to the selected gear stage n exceeds the allowable usage time, as in the case where the selected gear is selected, the process proceeds to step S206. The change gear ratio is controlled so that the change gear ratio γn ′ corresponding to the stage n is obtained.

  Here, in the above-described step S204, the flow chart of FIG. 3 and the shift speed of FIG. 5 will be described with respect to one mode of the speed ratio control performed so as to be the speed ratio γn corresponding to the speed n as selected in the manual mode. Further description will be given with reference to a diagram map.

  The flowchart of FIG. 3 is executed as a subroutine of step S204. First, in step S301, the vehicle speed and the engine speed at the time when the manual mode is selected during traveling in the predetermined continuously variable transmission mode are the engine speed, respectively. It is obtained based on input signals from the sensor 32 and the output shaft rotational speed sensor 62. If this point is represented as Pm in the shift map of FIG. 5, the vehicle speed at this time is V0 and the engine speed is Ne0. Then, the process proceeds to the next step S302, and in order to change only the engine speed without changing the vehicle speed so as to eliminate the uncomfortable feeling in driving, the speed ratio γn line corresponding to the selected gear stage n and the vehicle speed V0 The target engine speed Ne · n at the intersection Pn is obtained from the shift diagram map of FIG. In step S303, the gear ratio γn is controlled to be changed based on the actual input shaft rotational speed Nin so that the calculated target engine speed Ne · n is obtained. Thus, by controlling the hydraulic pressures of the hydraulic cylinders of the primary variable pulley 42 and the secondary variable pulley 46, the gear ratio is fixed to the gear ratio γn corresponding to the selected gear stage n.

  In the above description, the case where the shift speed n is selected in the manual mode has been representatively described. However, for example, the shift speeds 1, 2, 3, 4 and the shift speed n are set as selectable shift speeds. If so, the gear ratios corresponding to these are γ1, γ2, γ3, γ4, and γn, as shown in FIG. Therefore, for example, when the shift stage 3 is selected, the speed ratio γ3 is fixed in the shift diagram map of FIG.

  On the other hand, when the accumulated usage time at the gear ratio γn corresponding to the selected gear stage n in step S206 described above exceeds the allowable usage time, the changed gear ratio γn ′ corresponding to the gear stage n is obtained. One form of the change gear ratio control performed in the above will be further described with reference to the flowchart of FIG. 4 and the shift diagram map of FIG.

  The flowchart of FIG. 4 is executed as a subroutine of step S206. First, in step S401, as in the case described above, the vehicle speed V0 and the engine speed Ne0 at the point Pm when the manual mode is selected are respectively determined by the engine speed sensor. 32 and an input signal from the output shaft rotational speed sensor 62. Then, the process proceeds to the next step S402, and the target engine speed Ne · n ′ at the point Pn ′ at which the vehicle speed V0 is not changed at the change gear ratio γn ′ corresponding to the selected gear stage n is the shift diagram map of FIG. It is requested from. In step S403, the speed change ratio γn ′ is controlled based on the actual input shaft rotational speed Nin so that the calculated target engine speed Ne · n ′ is obtained. Thus, the hydraulic pressures of the hydraulic cylinders of the primary side variable pulley 42 and the secondary side variable pulley 46 are controlled, so that the speed ratio changes along the changed speed ratio γn ′ corresponding to the selected speed stage n. To be controlled. As a result, as the vehicle speed V changes, the contact surface positions of the cone surfaces of the pulleys 42 and 46 and the belt 48 are shifted without taking the same locus, so that uneven wear is suppressed.

  Here, the change gear ratio γn ′ described above is tested in advance so that the ratio of the change in the engine speed with respect to the change in the vehicle speed, that is, the change rate in the gear ratio γn corresponding to the selected gear stage n is the same. The ECU 100 is stored in the ECU 100 in the form of the shift map of FIG. In the above description, the case where the shift speed n is selected and the change gear ratio γn ′ is set in the manual mode is representatively described. For example, when the shift speed 3 is selected, the corresponding change gear shift is selected. The ratio γ3 ′ is not shown, but is the same as the rate of change of the speed ratio γ3, in the same way that the changed speed ratio γn ′ is represented as a line substantially parallel to the speed ratio γn in the speed map of FIG. Then, it is represented as a line parallel to the speed ratio γ3.

  By the way, the changed speed ratio γn ′ represented as a line parallel to the speed ratio γn corresponding to the speed stage n thus selected is theoretically the maximum speed ratio γmax side and the minimum speed ratio with respect to the speed ratio γn. There can be a plurality of each on the γmin side. Therefore, it is a problem to consider which of the plurality of change gear ratios γn ′ is set. In this regard, in the present embodiment, the contact raceway surface between the belt 48 and the pulleys 42 and 46 at the speed ratio γn corresponding to the selected gear stage n, and the belt 48 and both pulleys at the set change speed ratio γn ′. The change gear ratio γn ′ is set so that the contact surfaces with 42 and 46 do not overlap. This is because the change gear ratio γn ′ is set so that the contact surface is displaced by an amount corresponding to the thickness of the belt 48 in consideration of the thickness. In this way, uneven wear on the contact raceway surface between the belt 48 and the pulleys 42 and 46 at the speed ratio γn corresponding to the selected gear stage n can be reliably prevented.

  Further, the contact raceway surface between the belt 48 and the pulleys 42 and 46 to be taken into account when setting the above-described changed transmission gear ratio γn ′ is a contact raceway surface in a pulley having a relatively small winding radius. . For example, when the selected gear stage n is near the maximum gear ratio γmax, the primary-side variable pulley 42 having a relatively small winding radius, and when the selected gear stage n is near the minimum gear ratio γmin, The change gear ratio γn ′ is set so that the contact raceway surface of the secondary variable pulley 46 having a small wrapping radius does not overlap the contact surface between the belt 48 and the pulleys 42 and 46 at the set change gear ratio γn ′. Is set. In this way, it is possible to reliably prevent uneven wear on the contact raceway surface having a large surface pressure, and to reduce the amount of change from the gear ratio γn corresponding to the selected gear stage n. Because.

It is a block diagram showing the outline of the control apparatus of the continuously variable transmission to which this invention was applied. It is a flowchart which shows an example of the control routine of the belt-type continuously variable transmission mechanism in embodiment of this invention. It is a flowchart which shows an example of the gear ratio control subroutine in embodiment of this invention. It is a flowchart which shows an example of the change gear ratio control subroutine in embodiment of this invention. An example of the shift map map in embodiment of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Belt type continuously variable transmission 12 Engine 18 Belt type continuously variable transmission mechanism 32 Engine speed sensor 42 Primary side variable pulley 46 Secondary side variable pulley 48 Transmission belt 64 Shift lever mechanism 100 ECU

Claims (3)

In a continuously variable transmission control device capable of selecting either one of continuously variable transmission mode control and stepped transmission mode control,
Usage amount information acquisition means for acquiring usage amount information of the selected gear position when the stepped transmission mode is selected;
Condition determining means for determining whether or not the usage status exceeds a predetermined condition based on the usage amount information obtained by the usage amount information acquiring means;
When it is determined that the predetermined condition is satisfied by the condition determining means, the change gear ratio is different from the gear ratio corresponding to the selected gear, and the vehicle speed at the gear ratio corresponding to the selected gear is changed. A change gear ratio setting means for setting a change gear ratio at which the rate of change of the engine speed relative to the change is the same;
Transmission ratio control means for controlling the transmission ratio of the continuously variable transmission so as to coincide with the changed transmission ratio set by the changed transmission ratio setting means;
A control device for a continuously variable transmission.   The change gear ratio setting means prevents the contact track surface between the belt and the pulley at the gear ratio corresponding to the selected gear position from overlapping with the contact surface between the belt and the pulley at the set change gear ratio. 2. The continuously variable transmission control device according to claim 1, wherein a change gear ratio is set. 3. The continuously variable transmission control device according to claim 2, wherein a contact raceway surface between the belt and the pulley is a contact raceway surface in a pulley having a relatively small winding radius.

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