JP2007170595A - Vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt type continuously variable transmission capable of precisely controlling a gear ratio. <P>SOLUTION: Differential thrust between a driving pulley and a driven pulley is calculated from a feedback controlled variable based on a difference between a target gear ratio and an actual gear ratio. A correction coefficient is set in accordance with detected supercharging pressure for correcting the gear ratio feedback differential thrust. A gear ratio feedback pulley thrust difference is calculated by multiplying the gear ratio feedback differential thrust by the correction coefficient. Thereby, minimum hydraulic pressure rises to suppress a change in the gear ratio resulting from a change in input torque with supercharging pressure fluctuations while securing hydraulic pressure required to hold the gear ratio and achieve the target gear ratio, resulting in no shifting failure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  Vehicles, particularly vehicles having a belt-type continuously variable transmission that enables stepless shifting by changing the groove width of each pulley based on the thrust of a driving pulley and a driven pulley over which a belt is stretched It is.

  In the belt type continuously variable transmission, since power is transmitted by a belt stretched between a driving pulley and a driven pulley, it is important to prevent the belt from slipping. Therefore, in the conventional belt type continuously variable transmission, the target driven pulley pressure is obtained from the target gear ratio and the input torque, the target driven pulley pressure is calculated from the target driven pulley pressure and the speed change speed, and the target drive pulley is calculated. When the pressure is equal to or lower than the belt slip lower limit pressure, the target driven pulley pressure is calculated backward from the drive pulley side belt slip lower limit pressure. In this way, the target drive pulley pressure and the target driven pulley pressure are calculated to prevent the belt from slipping (see, for example, Patent Document 1).

  In this prior art, when shifting is performed by reducing the drive pulley pressure during downshifting, the drive pulley pressure may reach the belt slip lower limit pressure, which may cause belt slip.

  In order to solve this problem, the present applicant has determined that the pulley thrust corresponding to the pulley pressure is the lower limit thrust that does not cause belt slippage and the torque capacity securing thrust that is necessary for maintaining the actual gear ratio. Japanese Patent Application No. 2005-202178 discloses a control for reducing required hydraulic pressure while preventing belt slippage by using either primary pulley thrust or secondary pulley thrust as thrust according to the gear ratio. Have been filed. In this control, when the speed ratio is changed, the thrust difference between the pulleys is feedback controlled based on the difference between the actual speed ratio and the target speed ratio.

In addition, in a belt-type continuously variable transmission connected to an engine with a turbocharger, a safety factor is set according to the turbocharger supercharging pressure, this safety factor is maintained to maintain the gear ratio, and the belt does not slip. There is a technology that multiplies the standard minimum narrow pressure and presses the belt with the corrected standard minimum narrow pressure, thereby performing shift control and preventing belt slip due to an increase in input torque that increases due to an increase in supercharging pressure. (See Patent Document 2).
JP 2000-018347 A JP 2004-011837 A

  However, in the belt-type continuously variable transmission described in Patent Document 2, although belt slip is eliminated, in order to correct by multiplying the standard minimum narrow pressure considering the pressure necessary for maintaining the transmission ratio by multiplying by the safety factor, There is a problem that it is difficult to apply this technique to Japanese Patent Application No. 2005-202178 which divides this technology into torque capacity securing thrust and actual transmission ratio maintaining thrust and reduces the required hydraulic pressure.

  The present invention has been made in view of these facts, and an engine having a turbocharger and a belt connected to the engine and capable of reducing a necessary oil pressure while ensuring a pulley pressure that does not cause the belt to slip. An object of the present invention is to provide a vehicle equipped with a continuously variable transmission.

  The present invention relates to an engine equipped with a turbocharger, a supercharging pressure detecting means for detecting a supercharging pressure by the turbocharger, and a belt type connected to the engine and shifting the rotational speed of the engine in accordance with a predetermined gear ratio. A continuously variable transmission; and input torque calculating means for calculating a torque input to the continuously variable transmission according to an accelerator opening, wherein the belt-type continuously variable transmission is provided between a drive pulley and a driven pulley. A driving pulley thrust generating means for generating a target driving pulley thrust for realizing a target gear ratio by sandwiching the belt between the belt and the driving pulley; and a target gear shifting by clamping the belt to the driven pulley. Driven pulley thrust generating means for generating a target driven pulley thrust for realizing the ratio; and setting the target gear ratio to set the drive pulley thrust generating means and the driven pulley thrust. In a vehicle comprising a controller that controls the generating means, the controller calculates a driving torque capacity securing pulley thrust that the driving pulley holds without slipping the belt according to the input torque. Means, driven torque capacity ensuring pulley thrust calculating means for calculating according to the input torque, driven torque capacity securing pulley thrust that the driven pulley pinches without sliding the belt, and based on the detected supercharging pressure. Correction coefficient setting means for setting a correction coefficient for correcting the driving torque capacity securing pulley thrust, and a target driving torque capacity securing pulley that calculates the target driving torque capacity securing pulley thrust by multiplying the driving torque capacity securing pulley thrust and the correction coefficient Thrust calculation means and the drive variable required to maintain the current actual gear ratio Driving gear ratio holding pulley thrust calculating means for calculating the ratio holding pulley thrust based on the target driving torque capacity securing pulley thrust, and the driven gear ratio holding pulley thrust required to maintain the current actual gear ratio And a driven gear ratio maintaining pulley thrust calculating means for calculating based on the capacity securing pulley thrust.

  The present invention detects a supercharging pressure by a turbocharger, sets a correction coefficient based on the detected supercharging pressure, and calculates the correction coefficient according to an input torque based on an accelerator opening. In order to calculate the target driving torque capacity securing pulley thrust by multiplying the driving torque capacity securing pulley thrust that holds without slipping, the torque capacity securing hydraulic pressure is corrected by the correction coefficient according to the fluctuation of the supercharging pressure, and the appropriate The target drive torque capacity securing pulley thrust can be controlled to suppress the minimum hydraulic pressure rise to prevent belt slip.

  In addition, since the drive / driven pulley thrust necessary for achieving the target speed ratio and maintaining the speed ratio can be ensured, it is possible to prevent the possibility of poor transmission.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows a V-belt continuously variable transmission according to the present invention. This V-belt continuously variable transmission 1 has a primary pulley 2 and a secondary pulley 3 arranged so that their V-grooves are aligned, The V belt 4 is wound around the V grooves of the pulleys 2 and 3. The primary pulley (drive pulley) 2 has a coaxially arranged engine 5 having a turbocharger (hereinafter referred to as turbo) (not shown), and between the engine 5 and the primary pulley 2, a lockup torque converter 6 and The forward / reverse switching mechanism 7 is sequentially arranged.

  The rotation to the primary pulley 2 is transmitted to the secondary pulley (driven pulley) 3 via the V-belt 4, and the rotation of the secondary pulley 3 is then applied to a wheel (not shown) via the output shaft 8, the gear set 9 and the differential gear device 10. It reaches.

  Among the flanges forming the V-grooves of the primary pulley 2 and the secondary pulley 3 in order to change the rotational transmission ratio (hereinafter referred to as “speed ratio”) between the primary pulley 2 and the secondary pulley 3 during the power transmission. One is a fixed flange 2a, 3a, and the other flange 2b, 3b is a movable flange displaceable in the axial direction. These movable flanges 2b and 3b are respectively supplied with a primary pulley pressure Ppri and a secondary pulley pressure Psec, which are produced using a line pressure controlled as described later as a source pressure, to the primary pulley chamber 2c and the secondary pulley chamber 3c, respectively. The thrust toward the fixed flanges 2a and 3a is generated, and the V-belt 4 is sandwiched between the pulley flanges to enable the power transmission between the primary pulley 2 and the secondary pulley 3.

  However, when shifting, the V grooves of both pulleys 2 and 3 are changed by the differential pressure between the primary pulley pressure Ppri and the secondary pulley pressure Psec generated corresponding to the target gear ratio, as will be described later. The target gear ratio is realized by continuously changing the winding arc diameter of the V belt 4 with respect to the pulleys 2 and 3.

  Outputs of the primary pulley pressure Ppri and the secondary pulley pressure Psec are controlled by a shift control hydraulic circuit 11, and the shift control hydraulic circuit 11 is controlled in response to a signal from the transmission controller 12. Therefore, the transmission controller 12 has a signal from the primary pulley rotation sensor 13 that detects the primary pulley rotation speed Npri, a signal from the secondary pulley rotation sensor 14 that detects the secondary pulley rotation speed Nsec, and the depression of the accelerator pedal. A selection mode from a manual shift switch 17 that detects a signal from an accelerator pedal stroke sensor 16 that detects a stroke and a manual shift mode that prioritizes a shift by a driving operation or an automatic shift mode according to a shift command from the transmission controller 12 A fuel consumption request signal from an economy mode switch 19 for requesting driving with a focus on fuel consumption, a signal, a selection range signal from the inhibitor switch 17, a brake switch 18 for detecting depression of the brake pedal A pressure sensor 30 that detects a signal (engine speed, fuel injection time, etc.) related to the transmission input torque Ti from the engine controller 20 that controls the engine 5 and an intake pressure (= supercharging pressure during turbo operation). The signal from is input.

  FIG. 2 is a system diagram showing the transmission control hydraulic circuit 11 and the transmission controller 12. First, the transmission control hydraulic circuit 11 will be described. The circuit 11 includes an oil pump 21 that is driven by an engine. The hydraulic oil from the pump 21 to the oil passage 22 is used as a medium, and the pressure is adjusted to a predetermined line pressure PL by a pressure regulator valve 23.

  One of the line pressures PL of the oil passage 22 is adjusted as the primary pulley pressure Ppri by the pressure reducing valve 24 and supplied to the primary pulley chamber 2c, and the other is adjusted as the secondary pulley pressure Psec by the pressure reducing valve 25 and adjusted to the secondary pulley chamber 3c. To be supplied. However, the pressure regulator valve 23 controls the line pressure PL by the driving duty to the solenoid 23a, and the pressure reducing valves 24 and 25 control the primary pulley pressure Ppri and the secondary pulley pressure Psec by the driving duty to the solenoids 24a and 25a, respectively. To do.

  Further, the solenoid drive duty of the pressure regulator valve 23 and the solenoid drive duty of the pressure reducing valves 24 and 25 are determined by the transmission controller 12. That is, the transmission control hydraulic circuit 11 and the transmission controller 12 correspond to the drive pulley thrust generation means and the driven pulley thrust generation means.

  As will be described later, the transmission controller 12 determines the target gear ratio I from a map (not shown) from the accelerator pedal depression stroke and the vehicle speed VSP (here, the secondary pulley Nsec is multiplied by a predetermined constant). Ask. Then, an actual transmission ratio i is obtained from the primary pulley rotation speed Npri and the secondary pulley rotation speed Nsec, and a target transmission speed V (() using a map set in advance from the deviation between the target transmission ratio I and the actual transmission ratio i is used. I) is calculated. Further, the transmission controller 12 calculates a feedback control amount using a known PI feedback control or the like so as to eliminate the deviation between the target speed ratio I and the actual speed ratio i.

  FIG. 3 is a flowchart showing an example of hydraulic control executed by the transmission controller 12. This flowchart is repeatedly executed every predetermined time, for example, several tens of msec after the engine start is detected by turning on the ignition key or the like. The

  First, in step S1, the target primary torque capacity securing pulley thrust Fpri (f1) that the primary pulley 2 clamps without sliding the V-belt 4 and the target secondary torque capacity securing pulley that the secondary pulley 3 clamps without sliding the V-belt 4 The thrust Fsec (f1) is calculated from the transmission input torque Ti, the actual transmission ratio i, and the friction coefficient of the oil used.

  In the subsequent step S2, gear ratio holding pulley thrusts Fpri (f2) and Fsec (f2) of each pulley necessary for maintaining the current actual gear ratio are calculated. The transmission ratio maintaining pulley thrusts Fpri (f2) and Fsec (f2) are balanced hydraulic pressures that are actual transmission ratios based on the torque capacity securing pulley thrust F (f1) calculated in step S1, the current actual transmission ratio i, and the pulley ratio. Is calculated by subtracting the target torque capacity securing pulley thrust F (f1) from the balance hydraulic pressure.

  Next, in step S3, a shift speed pulley thrust difference F (v) required to achieve the target shift speed V (I) determined based on the driving state is calculated. That is, step S3 corresponds to a shift speed pulley thrust difference calculation means. The transmission speed pulley thrust difference F (v) may be calculated using, for example, a subroutine shown in FIG.

  In step S4, a gear ratio feedback pulley thrust difference F (fb) in the primary pulley 2 or the secondary pulley 3 is calculated based on the difference between the target gear ratio I and the actual gear ratio i. That is, step S4 corresponds to gear ratio feedback pulley thrust difference calculation means. Note that the gear ratio feedback pulley thrust difference F (fb) is calculated using, for example, a subroutine shown in FIG.

  In step S5, the transmission speed pulley thrust difference F (v) calculated in step S3 and the transmission ratio feedback pulley thrust difference F (fb) calculated in step S4 are added to obtain a transmission thrust F (th). Is calculated.

  Here, the shift thrust in the direction in which the gear ratio decreases the pulley ratio (upshift) is set to positive (+), and the shift thrust in the direction to increase the pulley ratio (downshift) is set to negative (-).

  In subsequent step S6, the shift thrust F (th) and the predetermined value F are compared. Specifically, the predetermined value F = 0 is set, and it is determined whether or not the shift thrust F (th) exceeds the predetermined value F = 0.

  Therefore, if it is determined in step S6 that the shift thrust F (th)> 0 and the upshift is being performed, in step S7, the target primary torque capacity securing pulley thrust Fpri (f1) calculated in step S1 is determined. And the gear shift thrust F (th) calculated in step S5 and the primary gear ratio maintaining pulley thrust Fpri (f2) calculated in step S2 are added to calculate the target drive pulley thrust Fpri (o). In step S8, the target secondary torque capacity securing pulley thrust Fsec (f1) calculated in step S1 is directly used as the target driven pulley thrust Fsec (o) (= Fsec (f1)).

  If it is determined in step S6 that the shift thrust F (th) ≦ 0 and a downshift is being performed, in step S9, the target primary torque capacity securing pulley thrust Fpri (f1) calculated in step S1 is used as the target. The driving pulley thrust Fpri (= Fpri (f1)) is assumed. In step S10, the target secondary torque capacity securing pulley thrust Fsec (f1) calculated in step S1, the absolute value | F (th) | Is added to the absolute value | Fsec (f2) | to calculate the target driven pulley thrust Fsec (o).

  In step S11, the target drive pulley pressure Ppri (o) to be regulated by the pressure reducing valve 24 is calculated based on the target drive pulley thrust Fpri (o) calculated in step S7 or 9. Specifically, the target drive pulley pressure Ppri (o) is calculated by dividing the target drive pulley thrust Fpri (o) by the pressure receiving area Spri of the primary pulley chamber 2c. In step S12, the target driven pulley pressure Psec (o) to be regulated by the pressure reducing valve 25 is calculated based on the target driven pulley thrust Fsec (o) calculated in step S8 or 10. Specifically, the target drive pulley pressure Psec is calculated by dividing the target drive pulley thrust Fsec by the pressure receiving area Ssec of the secondary pulley chamber 3c.

  Note that the relationship between the shift direction set in step S6 and the shift thrust may be set in reverse. That is, the shift thrust in the direction in which the gear shift direction decreases the pulley ratio (upshift) is set to negative (−), and the shift thrust in the direction to increase the pulley ratio (downshift) is set to positive (+). In this case, the determination in step S6 is control in which the shift thrust F (th) is less than 0 and the process proceeds to step S7, and when it is 0 or more, the process proceeds to step S9.

  Hereinafter, the calculation method used in step S1, step S3, and step S4 will be exemplified.

  4 shows a target primary torque capacity securing pulley thrust Fpri (f1) that the primary pulley 2 that is executed in step S1 of the flowchart shown in FIG. 3 does not slide the V belt 4, and the secondary pulley 3 uses the V belt 4. It is a subroutine which illustrates the calculation method with the target secondary torque capacity ensuring pulley thrust Fsec (f1) clamped without slipping.

  Referring to FIG. 4, first, in step S15, engine torque is calculated from the accelerator opening, gear ratio, etc., and in step S16, input torque to the primary pulley 2 is calculated using the calculated engine torque. In step S17, a primary torque capacity securing pulley thrust, which is a lower limit thrust for preventing belt slippage, is calculated based on the input torque calculated in step S16.

  On the other hand, in step S18, the boost pressure is detected using the pressure sensor 30, and in step S19, a feedback correction coefficient (correction coefficient ≧ 1) is set based on the detected boost pressure. The feedback correction coefficient is set according to the turbocharging pressure of the turbo provided in the engine. Specifically, the higher the supercharging pressure, the larger the feedback correction coefficient, and the smaller the lower the correction correction coefficient.

  In step S20, the target primary torque capacity securing pulley thrust Fpri (f1) is calculated by multiplying the correction coefficient set in step S19 by the primary torque capacity securing thrust calculated in step S17. The secondary torque capacity securing pulley thrust is set to the target secondary torque capacity securing pulley thrust Fsec (f1) calculated in step S17. The torque capacity securing pulley thrust is controlled by being converted into a hydraulic pressure (torque capacity securing hydraulic pressure).

  FIG. 5 is a subroutine illustrating a method for calculating the speed change pulley thrust difference F (v) executed in step S3.

  Referring to FIG. 5, first, in step S21, the target shift speed V (I) is determined based on the driving state such as the vehicle speed VSP, the selection range signal, the selection mode signal, and the accelerator pedal stroke amount obtained from the secondary pulley rotation speed Nsec. calculate. Next, in step S22, using the conversion magnification calculation map shown in FIG. 6, the conversion magnification mg (= Vp / V (I)) corresponding to the actual pulley ratio ip is obtained based on this map, and this conversion magnification mg. Is multiplied by the target shift speed V (I) in step S23 to calculate the pulley axial change speed Vp (= mg × V (I)).

  Then, in step S24, a shift speed pulley thrust difference F (v) is obtained based on the pulley change speed Vp calculated in step S23 using the shift speed pulley thrust difference calculation map shown in FIG. In the map of this embodiment, when the target pulley ratio Ip is large (in the negative (−) direction at the time of downshift), the shift pulley pulley thrust difference F (v) is equal to the secondary pulley thrust Fsec. When the target pulley ratio Ip is set to be large (the direction is positive (+) at the time of upshift), the shift speed pulley thrust difference F (v) is the primary pulley thrust Fpri. Is set to be large. In the map of FIG. 7, the side on which the target pulley ratio Ip becomes larger, that is, the secondary pulley thrust Fsec, among the gear shift speed thrust thrust difference F (v), achieves the target gear shift speed V (I) calculated in step S21. It is set to a value obtained by adding a predetermined margin or margin ratio to the shift speed pulley thrust difference necessary for this.

  FIG. 8 is a subroutine illustrating a method for calculating the gear ratio feedback pulley thrust difference F (fb) executed in step S4 of the flowchart shown in FIG.

  Referring to FIG. 8, first, in step S15, the actual speed ratio i is subtracted from the target speed ratio I to calculate the deviation between the target speed ratio I and the actual speed ratio i, and this deviation is used in step S16. The previous value of the integral deviation of the transmission system is added and updated to a new integral deviation. In step S17, the proportional compensation amount is calculated by multiplying the deviation calculated in step S15 by the proportional gain of the transmission system. Similarly, in step S18, an integral compensation amount is calculated by multiplying the integral deviation calculated in step S16 by the integral gain of the transmission system. In step S19, the gear ratio feedback pulley thrust difference F (fb) that is added to the primary pulley 2 or the secondary pulley 3 by adding the proportional compensation amount calculated in step S17 and the integral compensation amount calculated in step S18. Is calculated. In this embodiment, the PI control has been described. However, any control method itself such as PID control may be used as long as it controls feedback control.

  Next, a specific operation of this embodiment will be described with reference to time charts shown in FIGS. The control conditions described in this time chart are as follows. The target speed ratio is constant, and the speed ratio deviation between the actual speed ratio and the target speed ratio is always constant during feedback control. Therefore, the speed ratio feedback difference thrust is also constant. The case of a constant value will be described.

  First, the conventional control content shown in FIG. 10 will be described.

  Conventionally, a torque capacity securing hydraulic pressure that is a lower limit hydraulic pressure for preventing belt slippage is set according to the accelerator opening, the secondary pulley pressure Psec is controlled by this torque capacity securing hydraulic pressure, and the primary pulley pressure Ppri is a torque It is controlled by a hydraulic pressure obtained by adding a hydraulic pressure corresponding to a transmission ratio feedback differential thrust (a constant value in this figure) for maintaining the transmission ratio to the capacity ensuring hydraulic pressure. Here, the primary pulley pressure Ppri is set larger than the minimum pressing pressure calculated by multiplying the torque capacity securing hydraulic pressure by the safety factor set according to the supercharging pressure, and it is considered that no belt slip occurs. However, after the time T3, if the minimum pressing pressure is ensured, the oil pressure necessary for the shift, that is, the oil pressure corresponding to the gear ratio feedback differential thrust cannot be secured, and a shift failure may occur.

  Next, the control content of this embodiment is demonstrated using FIG.

  First, until the time T1, the supercharging pressure is approximately zero, and the primary pulley 3 has the target torque capacity securing hydraulic pressure calculated in step S20 and the gear ratio feedback in the supercharging pressure approximately zero calculated in step S4. The oil pressure corresponding to the pulley thrust force difference F (fb) is added and acts, and only the target torque capacity securing oil pressure acts on the secondary pulley 4. Here, the feedback correction coefficient for calculating the target torque capacity securing hydraulic pressure in the state of supercharging pressure≈0 is 1, that is, the torque capacity securing hydraulic pressure calculated based on the accelerator opening is the target torque capacity securing hydraulic pressure. Set to

  At time T1, the driver depresses the accelerator pedal, the estimated value of the input torque increases, and the target torque capacity securing hydraulic pressure is set to a larger value than before time T1 as the torque capacity securing hydraulic pressure increases. Therefore, the primary pulley pressure Ppri and the secondary pulley pressure Psec rise as the torque capacity securing hydraulic pressure increases (time T1 to T2).

  Then, the boost pressure starts to rise with a predetermined time lag from the time T1 when the accelerator opening is opened (time T2), and the feedback correction coefficient increases as the boost pressure increases. As the feedback correction coefficient increases, the target torque capacity securing hydraulic pressure further increases. For this reason, the primary pulley pressure Ppri and the secondary pulley pressure Psec increase with an increase in the target torque capacity securing hydraulic pressure due to an increase in the feedback correction coefficient.

  In the case of the present embodiment, the target primary torque capacity securing hydraulic pressure (pulley thrust) is multiplied by the torque capacity securing hydraulic pressure (pulley thrust) calculated according to the accelerator opening and the correction coefficient set according to the supercharging pressure. Because it is set, the torque capacity securing hydraulic pressure is corrected by the correction coefficient according to the fluctuation of the input torque due to the supercharging pressure fluctuation, and it is controlled to the appropriate target primary torque capacity securing hydraulic pressure to minimize the belt slippage. It is possible to suppress the hydraulic pressure from rising. As a result, the operating load of the hydraulic pump that supplies the hydraulic pressure to each pulley can be reduced, and the fuel consumption can be improved. Further, since the transmission ratio feedback pulley thrust difference F (fb) necessary for maintaining the transmission ratio can be set according to the input torque calculated based on the accelerator opening, the transmission ratio can always be maintained reliably. There will be no defects.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

It is the schematic of the V belt type continuously variable transmission which is one form of this invention. FIG. 2 is a system diagram showing a shift control hydraulic circuit and a transmission controller in the same form. 4 is a flowchart illustrating an example of hydraulic control executed by a transmission controller in the same form. 4 is a subroutine illustrating a method for calculating a torque capacity securing pulley thrust executed in step S1 of FIG. 4 is a subroutine illustrating a method for calculating a pulley thrust difference for speed change executed in step S3 of FIG. Fig. 6 is a conversion magnification calculation map used in step S22 of Fig. 5. 6 is a pulley speed difference calculation map for shift speed used in step S24 of FIG. 4 is a subroutine illustrating a method for calculating a gear ratio feedback pulley thrust difference executed in step S4 of FIG. 3. It is a time chart which illustrates operation | movement of this form. It is a time chart which illustrates the conventional operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 V belt type continuously variable transmission 2 Primary pulley 2a Fixed flange 2b Movable flange 2c Primary pulley chamber 3 Secondary pulley 3a Fixed flange 3b Movable flange 3c Secondary pulley chamber 4 V belt 5 Engine 11 Transmission control hydraulic circuit 12 Transmission controller 13 Primary Pulley rotation sensor 14 Secondary pulley rotation sensor 16 Accelerator pedal stroke sensor 17 Manual shift switch 17a Inhibitor switch 18 Brake switch 19 Economy mode switch 20 Engine controller 23 Pressure regulator valve 24 Primary pulley side pressure reducing valve 25 Secondary pulley side pressure reducing valve 30 Pressure sensor

Claims (2)

An engine with a turbocharger,
Supercharging pressure detecting means for detecting the supercharging pressure by the turbocharger;
A belt-type continuously variable transmission that is connected to the engine and changes the speed of the engine according to a predetermined gear ratio;
Input torque calculating means for calculating the torque input to the continuously variable transmission according to the accelerator opening;
The belt type continuously variable transmission is
A drive pulley thrust generating means for generating a target drive pulley thrust for realizing a target gear ratio by passing a belt between the drive pulley and the driven pulley and sandwiching the belt with the drive pulley;
Driven pulley thrust generating means for generating a target driven pulley thrust for realizing a target gear ratio by sandwiching the belt with the driven pulley;
In a vehicle comprising a controller that sets the target gear ratio and controls the driving pulley thrust generating means and the driven pulley thrust generating means,
The controller is
A driving torque capacity ensuring pulley thrust calculating means for calculating a driving torque capacity ensuring pulley thrust that the driving pulley holds without slipping the belt according to the input torque;
Driven torque capacity securing pulley thrust calculating means for calculating a driven torque capacity securing pulley thrust that the driven pulley pinches without sliding the belt according to the input torque;
Correction coefficient setting means for setting a correction coefficient for correcting the drive torque capacity securing pulley thrust based on the detected supercharging pressure;
A target driving torque capacity securing pulley thrust calculating means for calculating a target driving torque capacity securing pulley thrust by multiplying the driving torque capacity securing pulley thrust and the correction coefficient;
Drive gear ratio holding pulley thrust calculating means for calculating a drive gear ratio holding pulley thrust required to maintain the current actual gear ratio based on the target drive torque capacity securing pulley thrust;
Driven gear ratio holding pulley thrust calculating means for calculating the driven gear ratio holding pulley thrust required to maintain the current actual gear ratio based on the driven torque capacity securing pulley thrust;
A vehicle equipped with a belt-type continuously variable transmission.   2. The correction coefficient is set such that the thrust of the primary pulley changes according to a torque fluctuation that occurs when the target drive torque capacity securing pulley thrust is generated in response to supercharging of the turbocharger. Vehicle described in.

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