JP4162090B2 - Control device for continuously variable transmission for vehicle - Google Patents

Description

  The present invention relates to a control device for a continuously variable transmission for a vehicle capable of continuously changing the output of an internal combustion engine.

  As a conventional control device for this type of continuously variable transmission, for example, one disclosed in Patent Document 1 is known. This continuously variable transmission is a belt type applied to an internal combustion engine (hereinafter referred to as “engine”), and the width of the pulley groove of the driving pulley and the driven pulley around which the belt is wound is changed steplessly by hydraulic pressure. As a result, the gear ratio is changed steplessly. Further, this control device has an automatic transmission mode and a manual transmission mode as the transmission modes of the continuously variable transmission, and both the transmission modes are switched according to the operation position of the shift lever. In the automatic speed change mode, the target speed ratio is set in a stepless manner according to the vehicle speed and the like, and the speed ratio of the continuously variable transmission is controlled in a stepless manner so as to become the target speed ratio. On the other hand, in the manual speed change mode, the target speed change ratio is set to one of a plurality of predetermined speed change ratios based on the driver's designation, and the speed change ratio of the continuously variable transmission is stepped to be the target speed change ratio. It is controlled by.

  Specifically, in this control device, the change in the rotation ratio is based on the deviation between the set target gear ratio and the actual rotation ratio of both pulleys calculated from the detected rotation speeds of the drive pulley and the driven pulley. By determining the speed and outputting a control signal based on a value obtained by adding the change speed to the actual rotation ratio to the continuously variable transmission, feedback control is performed so that the speed ratio becomes the target speed ratio. In addition, this change speed is set to a larger value in the manual transmission mode than in the automatic transmission mode, so that in the manual transmission mode, the speed ratio of the continuously variable transmission is set to the driver. By quickly changing to the intended gear ratio, the drivability is improved.

  As described above, in this conventional continuously variable transmission control device, the change speed of the gear ratio, that is, the gain for feedback control of the gear ratio to the target gear ratio is greater in the manual gear shift mode than in the automatic gear shift mode. Is also set to a large value. For this reason, although the responsiveness of the control of the gear ratio in the manual transmission mode is improved, the convergence to the target gear ratio and the maintainability are lowered, and control hunting is likely to occur. Further, during the manual transmission mode, the speed of change of the transmission ratio is always set to a large value, so that the hydraulic pressure for controlling the transmission ratio must be kept high, leading to a reduction in fuel consumption. On the other hand, in order to solve such a problem, when the change speed of the gear ratio in the manual gear shift mode is set to a smaller value, the gear ratio is set particularly when the gear position is shifted in the manual gear shift mode. Drive the vehicle equipped with a continuously variable transmission with a stepped feeling because it cannot be quickly changed to the target gear ratio of the shift destination gear stage, and it takes a long time to shift the gear step, and it feels as if it is stiff. The advantage of the manual transmission mode is lost. In particular, in the recent automobile market, there is an increasing demand for more sporty driving of vehicles equipped with continuously variable transmissions, and conventional control devices cannot meet such demands.

  The present invention has been made to solve such problems, and in the stepped speed change mode, the speed change operation at the time of shifting the speed stage while maintaining good convergence of the speed ratio to the target speed ratio. An object of the present invention is to provide a control device for a continuously variable transmission for a vehicle that can improve the responsiveness of the vehicle.

JP-A-8-178000

In order to achieve this object, the invention according to claim 1 of the present application controls the gear ratio of the continuously variable transmission 40 capable of continuously changing the output of the internal combustion engine 2, and As one of the transmission modes, a stepped transmission in which the transmission ratio of the continuously variable transmission 40 is set to one of a plurality of predetermined transmission stages (first to seventh speeds in the embodiment (hereinafter the same in this section)). A control device for a continuously variable transmission for a vehicle having a mode (MT mode, AT mode), and when the transmission mode of the continuously variable transmission 40 is a stepped transmission mode, a plurality of transmission stages of the continuously variable transmission 40 are provided. Gear shift means (ECU 3, steps 24 and 25 in FIG. 6) for shifting from one of the predetermined gears to the other, and a target gear ratio (basic rotational speed NTIPHIL) according to the shifted gear Target gear ratio setting means (ECU3, Step 31 8, and 9), and the gear ratio control means for feedback control so that the target speed ratio of the transmission ratio is set in the continuously variable transmission 40 (ECU 3, the hydraulic control valve 46b), gear shift stage shift means The change speed control means for controlling the change speed of the speed ratio of the continuously variable transmission 40 to the target speed ratio when the gear position is shifted by the shift so as to be larger than the change speed when the gear speed is not shifted. (ECU 3, rotational speed correction amount NTIPUD, step 33 in FIG. 8, steps 46, 47, 50, and FIG. 11 in FIG. 10), and the changing speed control means is shifted when the shift speed is shifted. The target gear ratio set by the target gear ratio unit according to the selected gear stage is corrected to the decreasing side when the shift is shifted to the high speed stage side, and is increased when the shift is shifted to the low speed stage side. Target gear ratio correcting means for correcting the (ECU 3, step 33 in FIG. 8, step 10 46,47,50, 11), characterized in that a.

The control device for a continuously variable transmission for a vehicle has a stepped transmission mode in which the gear ratio is set to one of a plurality of predetermined gears as one of the transmission modes of the continuously variable transmission. In this stepped speed change mode, when the shift speed is shifted, the target speed ratio is set according to the shifted speed, and the speed ratio of the continuously variable transmission is set to the set target speed ratio. Feedback controlled. Further, the speed of change of the speed ratio of the continuously variable transmission to the target speed ratio when the shift speed is shifted is controlled to be larger than the speed of change when the speed speed is not shifted.

As described above, when the gear stage is shifted in the stepped transmission mode, the speed of change of the gear ratio to the target gear ratio is controlled to be larger, so that the gear ratio can be quickly adjusted to the target gear ratio of the shift destination gear stage. It is possible to improve the responsiveness of the speed change operation at the time of shifting the gear position, thereby obtaining a sporty step-like driving feeling. On the other hand, when the shift speed is not shifted in the stepped speed change mode, the speed change ratio is controlled to be smaller, so that the convergence of the speed ratio to the target speed change ratio can be maintained well. Stable gear ratio control can be realized while preventing this.
In addition, when the shift speed is shifted in the stepped shift mode, the target gear ratio set according to the shift speed after the shift is corrected to a lower side in the case of an upshift, and in the case of a downshift. Is corrected to the increasing side. In other words, the target gear ratio is corrected to be further decreased than usual in the case of upshifting and is further increased to be increased in the case of downshifting at the time of shifting the shift stage. The actual speed of change of the gear ratio when it is controlled to be the gear ratio can be increased by an amount corresponding to the increase / decrease correction of the target gear ratio compared to the non-shift state.

According to a second aspect of the present invention, in the control device 1 for a continuously variable transmission for a vehicle according to the first aspect, the input side rotational speed for detecting the input side rotational speed (drive pulley rotational speed NDRW) of the continuously variable transmission 40. Detection means (drive pulley rotational speed sensor 11) is further provided, and the target gear ratio correction means corrects the target gear ratio according to the detected input side rotational speed (rotation speed correction amount NTIPUD) and correction period. (Steps 47, 50, 54 to 56 in FIG. 10, FIG. 11) .

According to this configuration, the correction amount and the correction period for correcting the target gear ratio when the gear position is shifted in the stepped transmission mode are changed according to the detected input side rotational speed of the continuously variable transmission. Is done.

According to a third aspect of the present invention, in the control device 1 for a continuously variable transmission for a vehicle according to the first or second aspect, the target gear ratio correction means is configured to shift the shift destination when the gear stage is shifted to the high speed stage side. The target gear ratio is corrected only when the number of shift stages is a shift stage (second speed and third speed) equal to or less than a predetermined number of stages (FIG. 11).

According to this configuration, the stepped shift mode, when the shift stage is shifted to the high speed stage side, only when the shift destination gear is less than the shift speed predetermined number, execution correction of the target gear ratio Is done.

It is a figure which shows the structure of the vehicle drive system containing an internal combustion engine and a continuously variable transmission. It is a figure which shows roughly the control apparatus of the continuously variable transmission by this invention. It is a figure which shows the shift range and shift position of a shift lever. It is a figure which shows MT switch and a gear stage change switch. It is a flowchart which shows the setting process of transmission mode. It is a flowchart which shows the setting process of target rotation speed. It is a figure which shows an example of the gear stage table for setting a gear stage in AT mode. It is a flowchart which shows the setting process of target rotation speed NTIPSFT. It is a figure which shows an example of the NTIPHIL map used by the process of FIG. It is a flowchart which shows the calculation process of rotation speed correction amount NTIPUD. FIG. 11 is a diagram showing an example of an NTIPUDUP table and an NTIPUDDN table used in the processing of FIG. 10. It is a figure which shows an example of the DNTIPUDUP table for the time of upshift used by the process of FIG. It is a figure which shows an example of the TMTIPUDUP table for the time of upshift used by the process of FIG. It is a figure which shows an example of the DNTIPUDDN table for the time of downshift used by the process of FIG. It is a figure which shows an example of the TMTIPUDDN table for the time of downshift used by the process of FIG. It is a figure which shows the operation example at the time of the upshift obtained by the process of FIG. It is a figure which shows the operation example at the time of the downshift obtained by the process of FIG. It is a flowchart which shows the calculation process of drive current amount ICMDHC. It is a figure which shows an example of the KPHREVT table for the time of non-shift used by the process of FIG. It is a figure which shows an example of the KPHREVUP table for the time of upshift used by the process of FIG. It is a figure which shows an example of the KPHREVDN table for the time of downshift used by the process of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. 1 and 2 show a schematic configuration of a vehicle drive system including a control device 1 for a continuously variable transmission for a vehicle and an internal combustion engine 2 according to the present invention.

  An internal combustion engine (hereinafter referred to as “engine”) 2 is a gasoline engine and is mounted on a vehicle V. The engine 2 is connected to drive wheels 7 and 7 through a flywheel 4, an automatic transmission 5, a differential gear mechanism 6, and the like, and the torque of the engine 2 is driven through these elements 4 to 6. It is transmitted to the wheels 7 and 7.

  The flywheel 4 is connected to the crankshaft 2a of the engine 2, and transmits the torque of the engine 2 to the automatic transmission 5 in a state where the fluctuation is reduced and the torsional vibration is attenuated.

  The automatic transmission 5 includes a forward / reverse switching mechanism 30, a continuously variable transmission 40, a starting clutch 50, and the like. The forward / reverse switching mechanism 30 includes an input shaft 31 and a planetary gear device 32 attached to the input shaft 31. One end of the input shaft 31 is coupled to the flywheel damper 4 and penetrates through the hollow main shaft 41 in a freely rotatable manner. The planetary gear device 32 includes a sun gear 32a, a carrier 32d that rotatably supports a plurality of (for example, four) pinion gears 32b that mesh with the sun gear 32a, a ring gear 32c that meshes with each pinion gear 32b, and the like.

  The sun gear 32a is provided integrally with the input shaft 31, and a portion of the input shaft 31 closer to the engine 2 than the sun gear 32a is connected to the clutch inner 33a of the forward clutch 33. The clutch outer 33b includes a ring gear 32c and It is connected to the main shaft 41. Connection and disconnection of the forward clutch 33 are controlled by an ECU 3 described later. A reverse brake 34 is connected to the carrier 32d. The operation of the reverse brake 34 is also controlled by the ECU 3.

  With the configuration of the forward / reverse switching mechanism 30 described above, when the vehicle V moves forward, the reverse brake 34 is released and the forward clutch 33 is connected, whereby the input shaft 31 and the main shaft 41 are directly connected, and the input shaft 31 rotates. Is transmitted to the main shaft 41 as it is, and each pinion gear 32b does not rotate around its axis, and the carrier 32d rotates integrally with the input shaft 31 in the same direction. As described above, when the vehicle moves forward, the main shaft 41 rotates in the same direction as the input shaft 31 at the same rotational speed. On the other hand, when the vehicle V travels backward, contrary to the above, the forward clutch 33 is disconnected and the reverse brake 34 is engaged, whereby the carrier 32d is locked. As a result, the rotation of the input shaft 31 is transmitted to the ring gear 32c via the sun gear 32a and the pinion gear 32b, whereby the ring gear 32c and the main shaft 41 connected thereto rotate in the opposite direction to the input shaft 31. Thus, the main shaft 41 rotates in the direction opposite to the input shaft 31 when the vehicle is moving backward.

  The continuously variable transmission 40 is of a belt type and includes the main shaft 41, the drive pulley 42, the counter shaft 43, the driven pulley 44, and the like.

  The drive pulley 42 includes a frustoconical movable portion 42a and a fixed portion 42b. The movable portion 42a is attached to the main shaft 41 so as to be movable in the axial direction and non-rotatable. The fixed portion 42b is fixed to the main shaft 41 and faces the movable portion 42a. In addition, the surfaces of the movable portion 42a and the fixed portion 42b that face each other are formed in a slope shape, whereby a V-shaped belt groove 42c is formed by the movable portion 42a, the fixed portion 42b, and the main shaft 41. Has been.

  The driven pulley 44 is configured in the same manner as the drive pulley 42, and has a frustoconical movable portion 44a and a fixed portion 44b. The movable portion 44a is attached to the countershaft 43 so as to be movable in the axial direction and non-rotatable. The fixed portion 44b is fixed to the countershaft 43 and faces the movable portion 44a. Moreover, the mutually opposing surfaces of the movable portion 44a and the fixed portion 44b are each formed in a slope shape, and a V-shaped belt groove 44c is formed by the movable portion 44a, the fixed portion 44b, and the counter shaft 43.

  A metal belt 45 is wound between the belt grooves 42c and 44c of the pulleys 42 and 44. The movable portions 42a and 44a are provided with pulley width variable mechanisms 46 and 46 for moving them in the axial direction, respectively. Each pulley width variable mechanism 46 includes an oil chamber 46a provided on the back side of the movable portions 42a and 44a, a hydraulic control valve 46b for controlling the hydraulic pressure supplied to the oil chamber 46a, and the like. The hydraulic control valve 46b is configured by an electromagnetic valve, and its opening degree is controlled according to the amount of drive current supplied under the control of the ECU 3.

  With the configuration of the continuously variable transmission 40, the opening degree of the hydraulic control valve 46b is controlled by the ECU 3, whereby the hydraulic pressure of the oil chamber 46a is controlled, and the movable parts 42a and 44a are positioned at positions corresponding to the hydraulic pressure. Is done. Thereby, the distance between the movable parts 42a, 44a and the fixed parts 42b, 44b, that is, the widths of the belt grooves 42c, 44c are set steplessly, so that the distance between the main shaft 41 and the counter shaft 43 is increased. , That is, the speed ratio of the continuously variable transmission 40 can be controlled steplessly.

As will be described later, the speed change mode of the continuously variable transmission 40 is set to one of the following three speed change modes by the control device 1.
1. A continuously variable automatic transmission mode (hereinafter referred to as “CVT mode”) in which the gear ratio is set in a stepless manner in accordance with the driving state of the vehicle V.
2. A stepped automatic transmission mode (hereinafter referred to as “AT mode”) in which the transmission ratio is set to one of a plurality of predetermined transmission ratios according to the driving state of the vehicle V.
3. A stepped manual transmission mode (hereinafter referred to as “MT mode”) in which the transmission ratio is set to one of a plurality of predetermined transmission ratios in accordance with the driver's intention to change the transmission.
Thus, in the present embodiment, the stepped speed change mode (hereinafter referred to as “TIP mode” as appropriate) is configured by the AT mode and the MT mode.

  The starting clutch 50 connects and disconnects the gear 43a rotatably provided on the countershaft 43 and the countershaft 43, and its operation is controlled by the ECU 3. The gear 43a meshes with the gear 6a of the differential gear mechanism 6 via large and small idler gears 51a and 51b provided on the idler shaft 51. With the above configuration, when the start clutch 50 is connected, the rotation of the counter shaft 43 is transmitted to the drive wheels 7 and 7 through these gears 43a, 51a, 51b and 6a, whereby the vehicle V starts. Is done.

  FIG. 3 shows the shift range and shift position of the shift lever operated by the driver. As the shift range of the shift lever, parking (P), reverse (R), neutral (N), drive (D), sport (S), low (L) ranges are set, and the shift position is in that order. Are lined up. In this sports range, the gear ratio of the continuously variable transmission 40 is set to a higher side in order to use the engine in a higher rotation state. Further, the shift lever is provided with a shift position sensor 20 for detecting the shift position. The ECU 3 responds to the detection signal to the forward clutch 33, the reverse brake 34, the pulley width variable mechanism 46 and the start. The operation of the clutch 50 is controlled.

  As shown in FIG. 4, the handle H is provided with an MT switch 21 and shift speed change switches 22, 22. The shift speed change switches 22, 22 are on the left and right of the handle H, and the MT switch 21 is The switch 22 is disposed below the right switch 22. The MT switch 21 is operated by the driver in order to start or end the MT mode as the speed change mode of the continuously variable transmission 40. A signal representing the operation state of the MT switch 21 is output to the ECU 3, and the ECU 3 sets the speed change mode of the continuously variable transmission 40 in accordance with the operation signal as described later.

  Each gear change switch 22 is operated by the driver to shift the gear of the continuously variable transmission 40 during the MT mode, and includes an up switch 22a and a down switch 22b. A signal representing the operation state of the gear change switch 22 is output to the ECU 3, and the ECU 3 increases the gear by one step from the current gear every time the up switch 22a is operated during the MT mode and Each time the switch 22b is operated, the gear position is lowered by one.

  Further, the CRK signal is output from the crank angle sensor 10 to the ECU 3. This CRK signal is a pulse signal output at every predetermined crank angle as the crankshaft 2a of the engine 2 rotates. The ECU 2 calculates the rotational speed NE of the engine 2 based on this CRK signal. Further, the ECU 2 sends a detection signal indicating the rotational speed of the drive pulley 42 (hereinafter referred to as “drive pulley rotational speed”) NDRW from the drive pulley rotational speed sensor 11 to the speed of the vehicle V (hereinafter referred to as “vehicle speed”). )) And a detection signal representing an opening degree of an accelerator pedal (not shown) (hereinafter referred to as “accelerator opening degree”) AP is output from the accelerator opening degree sensor 13.

  In this embodiment, the ECU 3 constitutes a gear shift means, a target speed ratio setting means, a speed ratio control means, a change speed control means, a target speed ratio correction means, and a feedback gain setting means, and has an I / O interface. The microcomputer is composed of a CPU, RAM, ROM and the like. Detection signals from the sensors 10 to 13 and the switches 21 to 22 are input to the CPU after A / D conversion is performed by the I / O interface. In response to these detection signals, the CPU sets the transmission mode of the continuously variable transmission 40 to one of the CVT mode, the AT mode, or the MT mode according to a control program stored in the ROM and the set transmission mode. Accordingly, the gear ratio of the continuously variable transmission 40 is controlled.

  FIG. 5 is a flowchart showing a shift mode setting process for setting the shift mode of the continuously variable transmission 40. This process is executed when the shift range is set to the drive range or the sports range. First, in step 1 (illustrated as “S1”, the same applies hereinafter), it is determined whether or not a failure of the continuously variable transmission 40 has already been detected.

  If the answer is YES and a failure of the continuously variable transmission 40 is detected, the AT mode execution flag F_AT and the MT mode execution flag F_MT are set to “0” (steps 2 and 3), and this program ends. . On the other hand, if the answer to step 1 is NO, it is determined whether or not the MT mode execution flag F_MT and the AT mode execution flag F_AT are “1” (steps 4 and 5).

  When both of these answers are NO and F_MT = 0 and F_AT = 0, that is, when the shift mode is set to the CVT mode, it is determined whether or not the MT switch 21 has been operated (step 6). If the answer is NO and the MT switch 21 is not operated during the CVT mode, the program is terminated as it is and the CVT mode is maintained.

  If the answer to step 6 is YES and the MT switch 21 is operated during the CVT mode, the AT mode execution flag F_AT is set to “1” (step 7), and the transmission mode is set to the AT mode. As described above, when the MT switch 21 is operated during the CVT mode, the shift mode is not immediately switched to the MT mode but temporarily set to the AT mode. Since the answer to step 5 becomes YES by executing step 7, it is determined whether or not the MT switch 21 has been operated (step 8).

  If the answer is YES and the MT switch 21 is operated during the AT mode, the AT mode execution flag F_AT is set to “0” (step 9), and the shift mode is set to the CVT mode. With such a setting, when the MT switch 21 is erroneously operated during the CVT mode and thus the mode is shifted to the AT mode, the gear change mode is immediately returned to the CVT mode by operating the MT switch 21 again. Can be made.

  If the answer to step 8 is NO and the MT switch 21 is not operated during the AT mode, it is determined whether or not the up switch 22a or the down switch 22b of the gear position change switch 22 is operated (step 10). . If the answer is no and there is no such operation, the program is terminated as it is and the AT mode is maintained.

  If the answer to step 10 is YES and the upshift operation or downshift operation of the gear change switch 22 is performed during the AT mode, the operation of the MT switch 21 during the CVT mode is not an erroneous operation, and the driver The AT mode execution flag F_AT is set to “0” (step 11) and the MT mode execution flag F_MT is set to “1” (step 12), so that the transmission mode is changed from the AT mode to the MT mode. Switch to mode. By executing step 12, the answer to step 4 is YES. In this case, it is determined whether or not the MT switch 21 has been operated (step 13). If the answer is no, the program is terminated as it is and the MT mode is maintained.

  If the answer to step 13 is YES and the MT switch 21 is operated during the MT mode, the MT mode execution flag F_MT is set to “0” (step 14) to switch the shift mode from the MT mode to the CVT mode. End this program.

  FIG. 6 is a flowchart showing a target rotation speed setting process. In this process, the gear ratio or the gear position is set according to the shift mode set as described above and the driving state of the vehicle V, and the target rotation speed of the drive pulley rotation speed NDRW is set.

  In this process, first, in steps 21 and 22, it is determined whether or not the MT mode execution flag F_MT and the AT mode execution flag F_AT are “1”. When the answer to both steps is NO and the speed change mode is set to the CVT mode, the target rotational speed in the CVT mode is set (step 23), and this program is terminated. This target rotational speed is set according to the vehicle speed VP and the accelerator pedal opening AP based on a table (not shown). In this table, the target rotational speed is set to a larger value as the vehicle speed VP is larger and the accelerator pedal opening AP is larger. As described above, in the CVT mode, the gear ratio of the continuously variable transmission 40 is set steplessly by setting the target rotational speed steplessly in accordance with the vehicle speed VP and the accelerator pedal opening AP.

  On the other hand, if the answer to step 21 is YES and the shift mode is set to MT mode, the shift stage is set to one of the first to seventh stages according to the operation state of the shift stage change switch 22. (Step 24). Specifically, when the shift mode is switched from the AT mode to the MT mode, the shift stage is increased or decreased by one from the shift stage in the AT mode immediately before the switching, and then the shift stage change switch 22 is operated. Each time the speed is changed, the gear position is increased or decreased by one. Thus, in the MT mode, the gear position of the continuously variable transmission 40 is set to one of the first to seventh speeds according to the operation state of the gear position change switch 22 by the driver.

  When the answer to step 22 is YES and the speed change mode is set to the AT mode, the speed of the continuously variable transmission 40 is determined based on the speed table shown in FIG. (Step 25).

  This shift speed table is set separately for upshift (solid line) and downshift (dotted line), and the first to seventh shift speed regions are defined by boundary lines L12 to L67 and L21 to L76. They are divided and set so as to have a large hysteresis. Specifically, the setting / change of the gear position is performed as follows. Immediately after switching from the CVT mode to the AT mode, the gear position corresponding to the upshift region including the vehicle speed VP and the accelerator pedal opening AP is set. Further, for example, when the shift speed is set to the first speed, the boundary line L12 between the first speed and the second speed for the upshift is obtained when the accelerator pedal opening AP is constant and the vehicle speed VP is increased. Is exceeded, the shift speed is changed from the first speed to the second speed. Further, when the shift speed is set to the second speed, when the vehicle speed VP exceeds the downshift boundary L21 due to the decrease in the vehicle speed VP, the shift speed is changed from the second speed to the first speed. Be changed. As described above, in the AT mode, the gear position of the continuously variable transmission 40 is set to one of the first to seventh speeds according to the vehicle speed VP and the accelerator pedal opening AP.

  As described above, when the gear position is set in the MT mode or the AT mode, the gear position number TIPNO representing the set gear position is set. Specifically, the gear stage number TIPNO is set to a value of 1 to 7 when the gear stage is the first to seventh speeds, and is set to a value of 0 when the CVT mode is not set.

  Next, in step 26 following step 24 or 25, the target rotational speed NTIPSFT in the MT mode or AT mode, that is, the stepped transmission mode (TIP mode) is set according to the gear set as described above. End this program.

  The target rotational speed NTIPSFT is set according to the subroutine of FIG. In this process, first, the basic rotational speed NTIPHIL is obtained by searching the NTIPHIL map of FIG. 9 according to the gear position and vehicle speed VP set in step 24 or 25 (step 31). This NTIPHIL map defines the basic relationship of the target rotational speed with respect to the vehicle speed VP for each of the first to seventh speed gears, and its inclination corresponds to the gear ratio. For this reason, the basic rotational speed NTIPHIL is set such that the gradient with respect to the vehicle speed VP decreases as the gear position increases.

  Next, the rotational speed correction amount NTIPUD is calculated (step 32). This rotational speed correction amount NTIPUD is applied to increase the speed of change of the gear ratio when the gear position is shifted during the TIP mode, and is calculated by a calculation subroutine of FIG. 10 described later.

  Next, the target rotational speed NTIPSFT in the TIP mode is finally set by adding the rotational speed correction amount NTIPUD calculated in step 32 to the basic rotational speed NTIPHIL obtained in step 31 (step 33). Exit. Therefore, in the TIP mode, by controlling the continuously variable transmission 40 so that the drive pulley rotational speed NDRW becomes the target rotational speed NTIPSFT set as described above, the gear ratio of the continuously variable transmission 40 is set to the target rotational speed. It is controlled to a target gear ratio corresponding to several NTIPSFT.

  Next, the calculation process of the rotational speed correction amount NTIPUD executed in step 32 will be described with reference to FIG. In this process, first, it is determined whether or not the previous value TIPNO1 of the gear stage number TIPNO is a value 0 (step 41). When the answer is YES, that is, when this time is a loop immediately after the transition from the CVT mode to the TIP mode, a correction return amount DNTIPUD and a correction return delay time TMTIPUD, which will be described later, are respectively reset to 0 (steps 42 and 43). At the same time, the rotational speed correction amount NTIPUD is reset to 0 (step 44).

  On the other hand, if the answer to step 41 is NO and this time is the second and subsequent loops in which the transition from the CVT mode to the TIP mode is made, it is determined whether or not the gear stage number TIPNO is equal to the previous value TIPNO1 (step 45). . If the answer is YES and the shift stage is not shifted between the previous time and the current time, the routine proceeds to step 53 described later.

  If the answer to step 45 is NO and the gear position is shifted between the previous time and this time, it is determined whether or not the gear number TIPNO is larger than the previous value TIPNO1 (step 46). When this answer is YES, that is, when the shift of the current shift stage is an upshift, the rotation for upshift is performed by searching the NTIPUDUP table of FIG. 11 according to the shift stage number TIPNO and the drive pulley rotational speed NDRW. The number correction amount NTIPUDUP is obtained and set as the rotation number correction amount NTIPUD (step 47).

  As shown in the figure, this NTIPUDUP table is composed of two tables for the second and third speeds and for the fourth to seventh speeds. Among these, in the NTIPUDUP table for the second and third speeds, the rotational speed correction amount NTIPUDUP is set to a negative value, and when the drive pulley rotational speed NDRW is equal to or less than a first predetermined value NDRW (for example, 3000 rpm), The absolute value is set to increase linearly as the NDRW value increases. This is because the basic rotational speed NTIPHIL is set as shown in FIG. 9, and the higher the drive pulley rotational speed NDRW, the larger the rotational speed difference to be reduced at the time of upshifting. This is because sometimes the rotational speed correction amount NTIPUDUP for increasing the speed of change of the gear ratio also needs to be increased. Further, the rotational speed correction amount NTIPUDUP is set to a predetermined limit value NTIPUDUPLMT (for example, −300 rpm) regardless of the NDRW value so that it does not become an excessive value when the NDRW value is larger than the first predetermined value NDRW. .

  On the other hand, in the NTIPUDUP table for the fourth to seventh speeds, the rotational speed correction amount NTIPUDUP is set to 0 regardless of the drive pulley rotational speed NDRW. That is, in the case of upshifting to the fourth speed or higher, the correction using the rotation speed correction amount NTIPUD is not performed. This is because in the case of upshifting between middle and high gears, the difference in rotational speed that should be reduced during shifting is inherently small, so there is little need to increase the speed of change of the gear ratio during shifting. .

  Returning to FIG. 10, in step 48 following step 47, the correction return amount DNTIPUDUPn for the upshift is obtained by searching the table of FIG. 12 according to the gear stage number TIPNO, and set as the correction return amount DNTIPUD. . This correction return amount DNTIPUD is for gradually decreasing the rotational speed correction amount NTIPUD calculated at the time of shifting of the gear position (see FIG. 16A). As shown in FIG. 12, in this table, the correction return amount DNTIPUDUPn is set to −0.5 rpm when the shift destination gear is the second and third speeds, and is rotated when the fourth to seventh speeds. Since the correction by the number correction amount NTIPUD is not performed, the value is set to 0.

  Next, in step 49 following step 48, a correction return delay time TMTIPUDUPn for upshift is obtained by searching the table of FIG. 13 according to the gear stage number TIPNO, and is set as the correction return delay time TMTIPUD. Set to a count timer (not shown). This correction return delay time TMTIPUD determines the delay time until the rotation speed correction amount NTIPUD starts to be reduced by the correction return amount DNTIPUD after the shift stage is shifted (see FIG. 16A). As shown in FIG. 13, in this table, the correction return delay time TMITIPUDUPn is set to 500 ms when the shift destination gear stage is the second and third speeds, and the rotational speed correction when the fourth to seventh speeds. The value 0 is set because no correction is made by the amount NTIPU.

  On the other hand, when the answer to step 46 is NO and TIPNO <TIPNO1, that is, when the shift of the current shift stage is downshift, in steps 50 to 52, the same as in steps 47 to 49, for downshift The rotation speed correction amount NTIPUD, the correction return amount DNTIPUD, and the correction return delay time TMTIPUD are set. First, in step 50, the NTIPUDDN table in FIG. 11 is searched according to the gear stage number TIPNO and the drive pulley rotational speed NDRW to obtain the rotational speed correction amount NTIPUDDN for downshift and set as the rotational speed correction amount NTIPUD. To do. In this NTIPUDDN table, the rotational speed correction amount NTIPUDDN is set to a positive value, and when the drive pulley rotational speed NDRW is equal to or lower than a second predetermined value NDRW (for example, 5000 rpm), the rotational speed correction amount NTIPUDUP for upshifting For the same reason, it is set to increase linearly as the NDRW value increases. Further, when the NDRW value is larger than the second predetermined value NDRW, the rotation speed correction amount NTIPUDDN is set to a predetermined limit value NTIPUDDNLMT (for example, −250 rpm) regardless of the NDRW value.

  In step 51, the correction return amount DNTIPUDDNn for downshift is obtained by searching the table of FIG. 14 according to the gear stage number TIPNO, and is set as the correction return amount DNTIPUD. In this table, the correction return amount DNTIPUDDNn is set to 2 rpm when the shift destination gear stage is the first and second speeds, and to a smaller 0.5 rpm when the third to sixth speeds are set. This is because in TIP mode, the lower the gear position, the greater the slope of the basic rotational speed NTIPHIL with respect to the vehicle speed VP. Therefore, the rotational speed difference that should be increased during downshifting is inherently large. This is because it is necessary to increase the rotational speed correction amount NTIPUD for increasing the speed of change of the gear ratio.

  In step 52, the correction return delay time TMTIPUDDNn for downshift is obtained by searching the table of FIG. 15 according to the gear stage number TIPNO, set as the correction return delay time TMTIPUD, and set in the timer. In this table, the correction return delay time TMTIPUDDNn is set to a fixed value of 500 ms regardless of the shift speed of the shift destination.

  In step 53 following step 45, 49 or 52, it is determined whether or not the value of the timer set with the correction return delay time TMTIPUD is zero. When this answer is NO, the program is terminated as it is. That is, the rotational speed correction amount NTIPUD is held at the value set in step 47 or 50 until the correction return delay time TMTIPUD elapses after the shift stage is shifted.

  On the other hand, if the answer to step 53 is YES and the correction return delay time TMTIPUD has elapsed after shifting the gear position, it is determined whether or not the absolute value of the rotational speed correction amount NTIPUD is larger than the absolute value of the correction return amount DNTIPUD. A determination is made (step 54). If the answer is YES and | NTIPUD |> | DNTIPUD |, a value obtained by subtracting the correction return amount DNTIPUD from the rotational speed correction amount NTIPUD is set as a new rotational speed correction amount NTIPUD (step 55). finish. On the other hand, if the answer to step 54 is NO and | NTIPUD | ≦ | DNTIPUD | is satisfied, the rotational speed correction amount NTIPUD is set to 0 (step 56), and this program ends.

  As a result of the calculation process as described above, the rotational speed correction amount NTIPUD is used for upshifting immediately after the upshift (time point t1) as shown in FIG. Is set to a negative NTIPUDUP value (step 47), and is thereafter held at that value until the correction return delay time TMTIPUD elapses (between t1 and t2). By subtracting the correction return amount DNTIPUD of the value (step 55), the absolute value gradually decreases, and when the absolute value becomes equal to or smaller than the absolute value of the correction return amount DNTIPUD, the value becomes zero (t3). Is set. Note that, as described above, the calculation of the rotational speed correction amount NTIPUD is performed only in the case of upshifting to the second speed or the third speed, and the upshifting to the fourth speed or higher speed stage is performed. Not done in case.

  As described above, the target rotational speed NTIPSFT is calculated as the sum of the basic rotational speed NTIPHIL obtained from the map of FIG. 9 and the rotational speed correction amount NTIPUD. Therefore, as shown in FIG. 16 (b), the target rotational speed NTIPSFT is set immediately after the upshift as the rotational speed correction amount NTIPUD is set as described above. The third rotation speed) is corrected to a value reduced by the rotation speed correction amount NTIPUD from the basic rotation speed NTIPHIL, and then the correction return amount DNTIPUD is subtracted after the correction return delay time TMTIPUD has elapsed. It is gradually returned to NTIPHIL.

  Further, when the shift stage is downshifted, the rotational speed correction amount NTIPUD is set to a positive NTIPUDDN value for the downshift immediately after the downshift (time point t4), as shown in FIG. It is set (step 50), the value is held until the correction return delay time TMTIPUD elapses (between t4 and t5), and after that (after t5), the positive correction return amount DNTIPUD is subtracted. (Step 55), the value is gradually reduced, and is set to a value of 0 at a time point (t6) when it becomes equal to or less than the correction return amount DNTIPUD.

  Accordingly, as shown in FIG. 17 (b), the target rotational speed NTIPSFT is immediately after the downshift, and the rotational speed correction amount is higher than the basic rotational speed NTIPHIL of the shift speed stage (the fourth speed in this example). After the correction return delay time TMTIPUD has elapsed, the correction return amount DNTIPUD is subtracted to gradually return to the basic rotational speed NTIPHIL.

  As described above, at the time of the upshift of the gear position, the target rotational speed NTIPSFT is corrected to the decrease side by the rotational speed correction amount NTIPUD from the basic rotational speed NTIPHIL. Therefore, at the time of upshifting, the actual decrease speed of the drive pulley rotation speed NDRW when being controlled toward the target rotation speed NTIPSFT of the shift destination gear is increased by an amount corresponding to the decrease of the target rotation speed NTIPSFT. Thus, the speed of change of the gear ratio during upshifting can be made larger than that during non-shifting. Similarly, the target rotational speed NTIPSFT is corrected to an increase side by the rotational speed correction amount NTIPUD with respect to the basic rotational speed NTIPHIL when the shift stage is downshifted, so that the actual increase speed of the drive pulley rotational speed NDRW during the downshift is reduced. Therefore, the speed can be increased by an amount corresponding to the increase in the target rotational speed NTIPSFT, and the speed of change of the gear ratio during downshifting can be made larger than that during non-shifting.

  Therefore, it is possible to improve the responsiveness of the shift operation at the time of shifting the shift stage, thereby obtaining a sporty step-like driving feeling. On the other hand, when the gear position is not shifted in the TIP mode, the basic speed NTIPHIL is used as the target speed NTIPSFT, so that the speed change rate of the speed ratio is controlled to be smaller than that at the time of shifting. The ratio convergence can be maintained satisfactorily, whereby stable gear ratio control can be realized while preventing control hunting.

  Further, since the value of the rotational speed correction amount NTIPUD is held during the correction return delay time TMTIPUD after the shift, the effect of increasing the speed change rate by the rotational speed correction amount NTIPUD can be reliably obtained. Further, since the rotational speed correction amount NTIPUD is gradually returned by the correction return amount DNTIPUD and the target rotational speed NTIPSFT is gradually brought close to the basic rotational speed NTIPHIL, the gear ratio is set to the original target gear ratio that the shift destination gear stage should have. It can be returned smoothly.

  18 and 19 show a second embodiment of the present invention. In the present embodiment, the gain of the control term when the drive current amount ICMDHC to the hydraulic control valve 46b of the continuously variable transmission 40 is feedback-controlled so that the drive pulley rotational speed NDRW becomes the target rotational speed is set in the TIP mode. The change speed of the gear ratio is controlled by changing the gear ratio at the time of shifting the shift speed.

  FIG. 18 shows a calculation process of the drive current amount ICMDHC executed in the TIP mode. In this process, first, in step 61, a deviation (= NDRCMD-NDRW) between the target rotation speed NDRCMD and the drive pulley rotation speed NDRW is calculated and calculated as a rotation speed deviation NDRERR. In this case, the target rotational speed NDRCMD is equal to the basic rotational speed NTIPHIL obtained from the map of FIG. Next, a gain KPH of the P term (proportional term) of feedback control is obtained by searching a table (not shown) according to the drive pulley rotational speed NDRW (step 62).

  Next, it is determined whether or not the previous value TIPNO1 of the gear stage number TIPNO is 0 (step 63). If the answer is YES and this time is a loop immediately after the transition from the CVT mode to the TIP mode, the high rotation gain KPHREV (gain) of the P term (control term) is set to a predetermined initial value YKPHREV1 (step 64). Then, the process proceeds to step 70 described later.

  When the answer to step 63 is NO and this time is the second and subsequent loops in which the transition from the CVT mode to the TIP mode is performed, it is determined whether or not the gear position number TIPNO is larger or smaller than the previous value TIPNO1. (Steps 65 and 66). When both of these answers are NO, that is, when the shift stage is not shifted between the previous time and the current time, by searching the table of FIG. 19 according to the rotational speed deviation NDRERR calculated in step 61, A high rotation gain KPHREVT for non-shifting is obtained and set as the high rotation gain KPHREV (step 67). In this table, the high rotation gain KPHREVT is set to a larger value as the rotation speed deviation NDRERR is larger.

  If the answer to step 65 is YES and the gear position is upshifted between the previous time and this time, a high rotation gain for upshifting is obtained by searching the table of FIG. 20 according to the rotational speed deviation NDRERR. KPHREVUP is obtained and set as the high rotation gain KPHREV (step 68). In this table, the high rotation gain KPHREVUP is set to a larger value as the rotation speed deviation NDRERR is larger, and is set to a value larger than the value KPHREVT for non-shifting. In this table, the high rotation gain KPHREVUP is set to a smaller value as the gear position is higher. This is because the higher the gear position, the closer the hydraulic pressure supplied to the oil chamber 46a of the continuously variable transmission 40 approaches the limit value on the low gear ratio side. This is because if the change is made to the gear ratio side, the supply hydraulic pressure is further changed toward the limit value side, the supply hydraulic pressure has no margin, and the change speed of the gear ratio is more limited.

  On the other hand, if the answer to step 66 is YES and the gear position is downshifted, a high rotation gain KPHREVDN for downshifting is obtained by searching the table of FIG. 21 according to the rotation speed deviation NDRERR. The high rotation gain KPHREV is set (step 69). Also in this table, the high rotation gain KPHREVDN is set to a larger value as the rotation speed deviation NDRERR is larger, and is set to a value larger than the non-shift value KPHREVT. In this table, the high rotation gain KPHREVDN is set to a smaller value as the gear position is lower, contrary to that for upshifting. In the case of a downshift, contrary to the case of an upshift, the lower the gear position, the more the hydraulic pressure supplied to the oil chamber 46a is shifted from a state closer to the limit value on the high gear ratio side to a limit value side. This is because the speed of change of the gear ratio is more limited.

  Next, at step 70, the P-term PEH is calculated by multiplying the rotational speed deviation NDRERR by the gain KPH obtained at step 62 and the high rotation gain KPHREV obtained at step 64, 67, 68 or 69. .

  In the next step 71, the I term (integral term) SEHW is calculated from the rotational speed deviation NDRERR and the I term gain. Then, the drive current amount ICMDHC is calculated by adding the P term PEH and the I term SEHW to the basic current amount ICMDFF calculated based on the target gear ratio and the input torque from the engine 2 (step 72). Exit the program. By supplying the calculated drive current amount ICMDHC to the hydraulic control valve 46b of the continuously variable transmission 40, feedback control is performed so that the drive pulley rotational speed NDRW becomes the target rotational speed NDRCMD.

  As described above, according to the present embodiment, during the TIP mode, the high rotation gain KPHREV of the P term PEH of the drive current amount ICMDHC for performing feedback control so that the drive pulley rotation speed NDRW becomes the target rotation speed NDRCMD. At the time of upshifting and downshifting of the shift stage, it is set to a larger value than at the time of non-shifting. Therefore, when the shift speed is shifted, the speed of change of the gear ratio of the continuously variable transmission 40 is increased to increase the control responsiveness to the target speed ratio, and at the time of non-shift, the speed ratio to the target speed ratio. The effects of the first embodiment described above can be obtained in the same manner, such as maintaining good convergence.

  In addition, this invention can be implemented in various aspects, without being limited to the described embodiment. For example, in order to increase the speed of change of the gear ratio at the time of shifting the gear position, the first embodiment corrects the target rotational speed NTIPSFT by the rotational speed correction amount NTIPUD, and the second embodiment sets the target rotational speed NDRCMD. Although the setting of the high rotation gain KPHREV of the P-term PEH of the target feedback control is changed, this may be performed using other appropriate control parameters. For example, the gain of the hydraulic pressure supplied to the oil chamber 46a of the continuously variable transmission 40 can be changed.

  In the first embodiment, in the case of an upshift, the target rotational speed is corrected only when shifting to the second and third speeds. Sometimes you can go. Furthermore, in the first embodiment, the execution period of the correction of the target rotational speed is basically determined by time. For example, the end of the shift operation is determined, and the correction is ended according to the determination result. May be. The values of the rotational speed correction amount NTIPUD, the correction return amount DNTIPUD, and the correction return delay time TMTIPUD shown in the first embodiment are merely examples, and other values can be set as appropriate. Furthermore, in the second embodiment, the setting of the high rotation gain KPHREV of the P term PEH is changed only immediately after the shift stage is shifted, but this is performed for a predetermined time after the shift or until the shift operation is completed. It may be performed during this time.

  Further, the embodiment is an example in which the AT mode is provided in addition to the MT mode as the stepped transmission mode of the continuously variable transmission. However, in the case where only the MT mode is provided, the present invention is applied when shifting the gear stage. Of course, you may. In addition, it is possible to appropriately change the detailed configuration within the scope of the gist of the present invention.

Explanation of symbols

1 control device 2 engine (internal combustion engine)
3 ECU (speed stage shift means, target speed ratio setting means, speed ratio control means,
Change speed control means, target gear ratio correction means and feedback gain setting means)
40 continuously variable transmission 40b hydraulic control valve (speed ratio control means)
NTIPHIL Basic speed (target gear ratio)
NTIPUD rotation speed correction amount (change speed control means, target gear ratio correction means)
NTIPSFT Target speed PEHP P term (control term)
KPHREV High rotation gain (gain)
NDRCMD target speed (target gear ratio)

Claims (3)

The transmission ratio of the continuously variable transmission capable of continuously changing the output of the internal combustion engine is controlled, and as one of the transmission modes of the continuously variable transmission, the transmission ratio of the continuously variable transmission is set to a plurality of speed ratios. A control device for a continuously variable transmission for a vehicle having a stepped transmission mode set to one of predetermined gears,
Shift stage shifting means for shifting the shift stage of the continuously variable transmission from one of the plurality of predetermined shift stages to another when the shift mode of the continuously variable transmission is the stepped shift mode; ,
Target gear ratio setting means for setting a target gear ratio according to the shifted gear position;
Transmission ratio control means for performing feedback control so that the transmission ratio of the continuously variable transmission becomes the set target transmission ratio;
When the gear stage is not shifted, the speed change rate of the continuously variable transmission to the target gear ratio when the gear stage is shifted by the gear stage shifting means during the stepped transmission mode. Change rate control means for controlling the change rate to be greater than the change rate of
When the shift speed is shifted, the change speed control means is configured to change the target speed ratio set by the target speed ratio means according to the shifted speed speed to the shift speed to the high speed speed side. A control device for a continuously variable transmission for a vehicle, characterized in that it is a target gear ratio correcting means that corrects to a decrease side at times and corrects to an increase side when the shift is a shift to a low speed stage side. An input side rotational speed detection means for detecting an input side rotational speed of the continuously variable transmission;
2. The vehicle nothing according to claim 1, wherein the target gear ratio correction unit changes a correction amount and a correction period for correcting the target gear ratio in accordance with the detected input side rotational speed. Control device for step transmission. The target gear ratio correction means corrects the target gear ratio only when the gear position is shifted to a high speed side, and only when the gear position to be shifted is a gear position of a predetermined number or less. The control device for a continuously variable transmission for a vehicle according to claim 1, wherein:

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