JP7139070B2 - Gear control device for continuously variable transmission - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed change control device for a continuously variable transmission that is applied to a drive system of a vehicle and controls a speed ratio steplessly.

Conventionally, a control device used in a vehicle equipped with a continuously variable transmission capable of steplessly changing the power of an input shaft and transmitting it to an output shaft, and controlling the continuously variable transmission,
The gear ratio is changed between a plurality of stepwise fixed gear ratios in response to the shift operation in an automatic gear shift mode in which the gear ratio is changed without depending on the shift operation and a manual gear shift mode in which the gear ratio is selectively switched. manual transmission means;
rotation speed guard means for setting a minimum rotation speed of the input shaft in the manual shift mode and changing a gear ratio so that the rotation speed of the input shaft does not fall below the minimum rotation speed;
determining means for determining whether or not an acceleration request for accelerating the vehicle has been input;
A technique is disclosed that includes correction means that corrects to increase the minimum rotation speed when the acceleration request is input (see, for example, Patent Document 1).

JP 2016-102566 A

In the prior art, when the driver performs a shift-down request operation after the driver takes his foot off the accelerator pedal from the driving state, the input speed is set as the downshift amount by the unique rotation step due to the preset fixed gear ratio line. raise. As a result, when a downshift request operation is performed immediately after the accelerator foot is released, if the rotational step (downshift amount) is small, the driver's deceleration request may not be met if the driver desires deceleration by engine braking. There is a problem that a response feeling of deceleration cannot be obtained. On the other hand, if the rotation step (downshift amount) is large, when the driver wants to reaccelerate immediately after taking his/her foot off the accelerator pedal, there is the problem that the feeling of reacceleration that responds to the driver's request for reacceleration cannot be obtained. there were.

The present invention has been made with a focus on the above-mentioned problems, and achieves both a feeling of re-acceleration in response to the driver's request for re-acceleration and a feeling of deceleration in response to the driver's deceleration request in the transition scene from driving to accelerator pedal release. intended to

In order to achieve the above object, a shift control apparatus for a continuously variable transmission of the present invention includes a variator mounted in a drive system from a drive source for traveling to drive wheels, and a shift controller for controlling the gear ratio of the variator.
When the manual shift mode is selected, the shift controller has a predetermined rotational step with respect to the input rotational speed of the variator at the time of the shift request operation based on the shift request operation by the driver instead of a plurality of preset fixed gear ratios. It has a flexible manual shift control section that performs gear ratio control to shift the gear ratio of the variator to the target input speed.
When the flexible manual shift control unit detects an accelerator foot release operation in a driving state, the rotation step set by the downshift request operation before a predetermined time has passed since the detection is performed after the predetermined time has passed. Set smaller than the rotation step set by the downshift request operation.

That is, the flexible manual shift control section can flexibly set the rotational step of the input rotational speed to be increased by downshifting without being restricted by a fixed gear ratio. Taking advantage of this flexibility, when shifting from driving to accelerator pedal release, the rotation step in response to the driver's shift down request operation is set differently immediately after the transition and after a predetermined time has elapsed from the transition. Therefore, in the scene of transition from driving to accelerator pedal release operation, both the feeling of reacceleration in response to the driver's request for reacceleration and the deceleration feeling in response to the driver's deceleration request can be achieved.

1 is an overall system diagram showing a drive system and a control system of an engine vehicle equipped with a belt-type continuously variable transmission to which the shift control device of Embodiment 1 is applied; FIG. 1 is a schematic system diagram showing a shift control device for a belt-type continuously variable transmission applied to an engine vehicle; FIG. FIG. 4 is a shift map diagram showing an example of a D-range continuously variable shift map used by a continuously variable shift control section when selecting a continuously variable shift mode in the D range; FIG. 4 is a shift map diagram showing an example of a manual shift map used by a flexible manual shift control section when a manual shift mode is selected; 5 is a flow chart showing the flow of flexible manual shift control processing that is executed in the flexible manual shift control section of the shift controller when the driver performs a downshift request operation while the accelerator is off. FIG. 10 is a shift map diagram showing an example of a D-range manual stepped shift map used when selecting a manual shift mode in the background art; FIG. 10 is a problem explanatory diagram showing a problem in the background art when a driver performs a downshift request operation immediately after the accelerator foot is released and a problem when the driver performs a downshift request operation after a predetermined time has passed since the accelerator foot is released; 5 is a time chart showing a manual downshift operation when a select operation is performed by the driver immediately after the accelerator foot is released, and the select operation and downshift request operation are performed twice after the coasting judgment is performed in the first embodiment. Effect explanatory diagram showing the movement of the driving point in the manual downshift when the select operation is performed by the driver immediately after the accelerator foot is released in the first embodiment, and the select operation and the downshift request operation are performed twice after the coasting judgment is performed in the first embodiment. is.

MODES FOR CARRYING OUT THE INVENTION A mode for implementing a shift control device for a continuously variable transmission according to the present invention will be described below based on a first embodiment shown in the drawings.

The shift control device for a continuously variable transmission according to the first embodiment is applied to an engine vehicle equipped with a belt-type continuously variable transmission comprising a torque converter, a forward/reverse switching mechanism, a variator, and a final reduction mechanism. Hereinafter, the configuration of the first embodiment will be described by dividing it into "overall system configuration", "system configuration of shift control device", and "flexible manual shift control processing configuration".

[Overall system configuration]
FIG. 1 shows the drive system and control system of an engine vehicle to which the shift control device of the first embodiment is applied. The overall system configuration will be described below with reference to FIG.

As shown in FIG. 1, the drive system of the engine vehicle includes an engine 1, a torque converter 2, a forward/reverse switching mechanism 3, a variator 4, a final reduction mechanism 5, and drive wheels 6 and 6. there is Here, the belt-type continuously variable transmission CVT is configured by incorporating the torque converter 2, the forward/reverse switching mechanism 3, the variator 4, and the final reduction mechanism 5 into a transmission case (not shown).

The engine 1 can control the output torque by an engine control signal from the outside, in addition to the control of the output torque by the driver's accelerator operation (normal control). The engine 1 has an output torque control actuator 10 that performs torque reduction control in cooperation with the transmission. Note that in the torque down control, the engine torque is restricted so as not to exceed the upper limit torque by means of ignition timing retard control, throttle valve closing control, etc. of the engine 1 .

The torque converter 2 is a starting element with a fluid coupling having a torque amplifying function and a torque fluctuation absorbing function. It has a lockup clutch 20 that can directly connect the engine output shaft 11 (=torque converter input shaft) and the torque converter output shaft 21 when the torque amplifying function and the torque fluctuation absorbing function are not required. The torque converter 2 includes a pump impeller 23, a turbine runner 24, and a stator 26 provided on a case via a one-way clutch 25 as constituent elements.

The forward/reverse switching mechanism 3 is a mechanism for switching the input rotational direction to the variator 4 between the forward rotation direction during forward travel and the reverse rotation direction during reverse travel. The forward/reverse switching mechanism 3 has a double pinion planetary gear 30 , a forward clutch 31 , and a reverse brake 32 . The forward clutch 31 is hydraulically engaged by a forward clutch pressure Pfc when a forward travel range such as the D range is selected. The reverse brake 32 is hydraulically engaged by a reverse brake pressure Prb when a reverse travel range such as the R range is selected. The forward clutch 31 and the reverse brake 32 are both released by draining the forward clutch pressure Pfc and the reverse brake pressure Prb when the N range (neutral range) is selected.

The variator 4 has a primary pulley 42, a secondary pulley 43, and a pulley belt 44, and steplessly changes the gear ratio (the ratio of the variator input rotation to the variator output rotation) by changing the belt contact diameter. It is a transmission mechanism.

The primary pulley 42 is composed of a fixed pulley 42 a and a slide pulley 42 b coaxially arranged on the variator input shaft 40 , and the slide pulley 42 b is slid by the primary pressure Ppri guided to the primary pressure chamber 45 .

The secondary pulley 43 is composed of a fixed pulley 43 a and a slide pulley 43 b which are coaxially arranged on the variator output shaft 41 .

The pulley belt 44 is stretched over the V-shaped sheave surface of the primary pulley 42 and the V-shaped sheave surface of the secondary pulley 43 . The pulley belt 44 is formed of two sets of laminated rings in which a large number of annular rings are superimposed from the inside to the outside, and a punched plate material. Consists of elements. The pulley belt 44 may be a chain-type belt in which a large number of chain elements arranged in the pulley advancing direction are connected by pins penetrating in the pulley axial direction.

The final reduction gear mechanism 5 is a mechanism that reduces the speed of the variator output rotation from the variator output shaft 41 and provides a differential function to transmit it to the left and right driving wheels 6 , 6 . The final reduction mechanism 5 includes, as reduction gear mechanisms, an output gear 52 provided on the variator output shaft 41, an idler gear 53 and a reduction gear 54 provided on the idler shaft 50, and a final gear provided on the outer periphery of the differential case. a gear 55; A differential gear 56 interposed between the left and right drive shafts 51, 51 is provided as a differential gear mechanism.

The control system of the engine vehicle includes a hydraulic control unit 7 as a hydraulic control system, a CVT control unit 8 as an electronic control system, and an engine control unit 9, as shown in FIG. The CVT control unit 8 and the engine control unit 9 are connected by a CAN communication line 13 so that information can be exchanged.

The hydraulic control unit 7 controls the primary pressure Ppri guided to the primary pressure chamber 45, the secondary pressure Psec guided to the secondary pressure chamber 46, the forward clutch pressure Pfc to the forward clutch 31, the reverse brake pressure Prb to the reverse brake 32, and the like. It is a unit that regulates pressure. The hydraulic control unit 7 includes a hydraulic pressure source 70 that is provided by at least one of a mechanical oil pump that is rotationally driven by the engine 1 and an electric oil pump that is rotationally driven by an electric motor. and a hydraulic control circuit 71 for adjusting the control pressure.

The hydraulic control circuit 71 has a line pressure solenoid valve 72 , a primary pressure solenoid valve 73 , a secondary pressure solenoid valve 74 , a select solenoid valve 75 and a lockup pressure solenoid valve 76 . Each solenoid valve 72 , 73 , 74 , 75 , 76 regulates the command pressure according to the solenoid command value output from the CVT control unit 8 .

The line pressure solenoid valve 72 adjusts the discharge pressure from the hydraulic source 70 to the commanded line pressure PL according to the line pressure command value output from the CVT control unit 8 . This line pressure PL is a source pressure for regulating various control pressures, and is a hydraulic pressure that suppresses belt slippage and clutch slippage with respect to the torque transmitted through the drive system. The other solenoid valves 73, 74, 75, 76 reduce and adjust the line pressure PL to the commanded hydraulic pressure using the line pressure PL as the original pressure.

The CVT control unit 8 performs line pressure control, shift control, forward/reverse switching control, lockup control, and the like. In the line pressure control, a command value for obtaining a target line pressure corresponding to the accelerator opening APO or the like is output to the line pressure solenoid valve 72 . In shift control, once a target gear ratio (target primary rotation Npri ^* ) is determined, a command value for obtaining the determined target gear ratio (target primary rotation Npri ^* ) is output to primary pressure solenoid valve 73 and secondary pressure solenoid valve 74 . In the forward/reverse switching control, a command value for controlling engagement/disengagement of the forward clutch 31 and the reverse brake 32 is output to the select solenoid valve 75 according to the selected range position. In the lockup control, a command value for controlling the lockup control pressure PL/U for engaging/slipping/releasing the lockup clutch 20 is output to the lockup pressure solenoid valve 76 .

Information from a primary rotation sensor 80 , a vehicle speed sensor 81 , a secondary rotation sensor 82 , an oil temperature sensor 83 , an inhibitor switch 84 , a brake switch 85 and a turbine rotation sensor 86 is input to the CVT control unit 8 . Further, information from the shift mode selection switch 87, the shift operation switch 88, etc. is input. Information is input to the engine control unit 9 from an accelerator opening sensor 90, an engine rotation sensor 91, and the like.

[System configuration of transmission control device]
FIG. 2 shows a shift control device for a belt-type continuously variable transmission CVT applied to an engine vehicle. The system configuration of the shift control device will be described below with reference to FIGS. 2 to 4. FIG.

As shown in FIG. 3, the drive system of the engine vehicle includes an engine 1 (driving source for running), a belt-type continuously variable transmission CVT (torque converter 2, forward/reverse switching mechanism 3, variator 4, final reduction mechanism 5). and drive wheels 6.

The torque converter 2 of the belt-type continuously variable transmission CVT has a lockup clutch 20 that directly connects the engine output shaft 11 (=torque converter input shaft) and the torque converter output shaft 21 by engagement. The forward/reverse switching mechanism 3 has a forward clutch 31 engaged by selecting a forward traveling range (D range, L range, etc.) and a reverse brake 32 engaged by selecting a reverse traveling range (R range) in parallel. have. The variator 4 (continuously variable transmission mechanism) has a primary pulley 42 , a secondary pulley 43 , and a pulley belt 44 stretched over both pulleys 42 and 43 .

The hydraulic control system of the shift control device includes a hydraulic source 70, a hydraulic control circuit 71, a primary pressure solenoid valve 73, and a secondary pressure solenoid valve 74, as shown in FIG.

The primary pressure solenoid valve 73 uses, as a source pressure, the line pressure adjusted based on the discharge pressure from the hydraulic pressure source 70 in the hydraulic control circuit 71 during shift hydraulic control, and the primary pressure solenoid valve 73 receives a primary pressure control command from the CVT control unit 8. Adjust the primary pressure Ppri. The regulated primary pressure Ppri is then guided to the primary pressure chamber 45 of the primary pulley 42 of the variator 4 .

The secondary pressure solenoid valve 74 uses, as the source pressure, the line pressure adjusted based on the discharge pressure from the hydraulic pressure source 70 in the hydraulic control circuit 71 during shift hydraulic control, and the secondary pressure control command from the CVT control unit 8 Adjust the secondary pressure Psec. Then, the regulated secondary pressure Psec is guided to the secondary pressure chamber 46 of the secondary pulley 43 of the variator 4 .

As shown in FIG. 2, the electronic control system of the transmission control device is provided with a CVT control unit 8. The CVT control unit 8 includes a primary rotation sensor 80, a vehicle speed sensor 81, an inhibitor switch 84, a transmission mode selection switch 87, a shift Information is input from the operation switch 88, the accelerator opening sensor 90, and the like.

Here, the primary rotation sensor 80 detects the actual primary rotation speed Npri of the primary pulley 42 . A vehicle speed sensor 81 detects a vehicle speed VSP. The inhibitor switch 84 detects the range position (R range, N range, P range, D range, L range, etc.) selected by the driver. An accelerator opening sensor 90 detects an accelerator opening APO (a driver's accelerator operation amount) and supplies information on the accelerator opening APO to the CVT control unit 8 via the CAN communication line 13 .

The speed change mode selection switch 87 is a switch for selecting either a "continuously variable speed mode" or a "manual speed change mode" by driver operation, and outputs a continuously variable speed mode selection signal and a manual speed change mode selection signal. do.

When the "manual gear shift mode" is selected, the shift operation switch 88 outputs a shift-up request signal by a driver's operation intended to shift up, and outputs a shift-down request signal by a driver's operation intended to shift down. Note that the driver operation includes, for example, a lever operation on an upshift/downshift operation lever, a button operation on an upshift/downshift operation button, or a switch operation on an upshift/downshift seesaw switch. Say.

As shown in FIG. 2, the CVT control unit 8 includes a shift controller 800 that shares the shift control function of the variator 4 of the belt-type continuously variable transmission CVT. The shift controller 800 has a shift mode selection section 801 , a stepless shift control section 802 , a flexible manual shift control section 803 and a solenoid command output section 804 .

The shift mode selection unit 801 receives switch signals from the inhibitor switch 84 and the shift mode selection switch 87 . When it is in the D range and in the "continuously variable transmission mode", the continuously variable transmission control process by the continuously variable transmission control unit 802 is selected. On the other hand, when it is in the D range and in the "manual shift mode", manual shift control processing by flexible manual shift control section 803 is selected.

When the "continuously variable transmission mode" is selected, the continuously variable transmission control unit 802 uses the D-range continuously variable transmission map M1 shown in FIG. , is executed. Continuously variable transmission control unit 802 outputs target primary rotation speed Npri(C) ^* to solenoid command output unit 804 as a result of continuously variable transmission control processing.

When the "manual shift mode" is selected, the flexible manual shift control unit 803 uses the manual shift map M2 shown in FIG. Execute control processing. Flexible manual shift control unit 803 sends solenoid command output unit 804 based on the shift request operation by the driver and the driving state of the vehicle. Output the primary rotation speed Npri(M) ^* . The reason why the flexible manual shift control unit 803 is used here is that the manual shift map M2 does not have a fixed gear ratio line, and is highly flexible in that it can draw an infinite number of fixed gear ratio lines according to the driving situation. This is due to the fact that it is a manual shift control section based on a control law. For example, if the driver requests an upshift, the target primary rotation speed Npri(C) ^* is set by subtracting the input rotation speed difference ΔNup from the actual primary rotation speed Npri, and the upshift is performed. . Also, if there is a downshift request operation by the driver, the target primary rotation speed Npri(C) ^* is set by adding the rotation step ΔNdwn of the input rotation speed to be increased by downshifting to the actual primary rotation speed Npri, and the downshift is performed. .

Solenoid command output unit 804 receives target primary rotation speed Npri(C) ^* from continuously variable transmission control unit 802 when the "continuously variable transmission mode" is selected. Then, a primary pressure control command and a secondary pressure control command for converging the actual primary rotation speed Npri to the target primary rotation speed Npri(C) ^* are calculated. On the other hand, when the “manual shift mode” is selected, the target primary rotation speed Npri(M) ^* is input from flexible manual shift control section 803 . Then, a primary pressure control command and a secondary pressure control command for converging the actual primary rotation speed Npri to the target primary rotation speed Npri(M) ^* are calculated. The calculated primary pressure control command is output to the primary pressure solenoid valve 73 and the secondary pressure control command is output to the secondary pressure solenoid valve 74 .

Next, the details of the continuously variable transmission control section 802 will be described. FIG. 3 shows an example of a D-range continuously variable transmission map M1 used by the continuously variable transmission control section when selecting the continuously variable transmission mode in the D range. In the D-range continuously variable transmission map M1, the lowest gear ratio line, the highest gear ratio line, and the coast gear ratio line are written on a two-dimensional coordinate plane in which the vertical axis is the target primary rotation speed Npri ^* and the horizontal axis is the vehicle speed VSP. It is a gear shift map. Note that when the lockup clutch 20 of the torque converter 2 and the forward clutch 31 of the forward/reverse switching mechanism 3 are engaged while the vehicle is traveling forward, the actual primary rotation speed Npri, which is the input rotation speed to the variator 4, is It becomes the engine rotation speed Ne as it is.

Continuously variable transmission control using the D-range continuously variable transmission map M1 is performed at the position of the operating point (VSP, APO) within the hatched area surrounded by the lowest gear ratio line, the highest gear ratio line, and the coast gear ratio line. It is executed by determining the target primary rotation speed Npri ^* accordingly. As is clear from the lowest gear ratio line and the highest gear ratio line of the D-range continuously variable transmission map M1, the gear ratio is the slope of the fixed gear ratio line (=equivalent gear ratio line) drawn from the zero operating point. is represented by Determining the target primary rotation speed Npri ^* based on the position of the operating point (VSP, APO) is equivalent to determining the target gear ratio of the variator 4 from the relationship with the secondary rotation speed Nsec (=vehicle speed VSP).

For example, when the vehicle speed VSP is constant, when the accelerator is depressed, the target primary rotation speed Npri ^* increases due to the increase in the accelerator opening APO, and the gear shifts in the downshift direction. For example, when the vehicle speed VSP is constant, when the accelerator pedal is released, the target primary rotation speed Npri ^* decreases due to the decrease in the accelerator opening APO, and the gear shifts in the upshift direction. For example, when the accelerator opening APO is constant, when the vehicle speed VSP increases, the gear shifts toward the highest gear ratio line in the upshift direction, and when the vehicle speed VSP decreases, the gear shifts toward the lowest gear ratio line in the downshift direction.

Next, the details of flexible manual shift control section 803 will be described. FIG. 4 shows an example of the manual shift map M2 used by the flexible manual shift control section 803 when the manual shift mode is selected. The manual shift map M2 is plotted on a two-dimensional coordinate plane with the target primary rotation speed Npri ^* on the vertical axis and the vehicle speed VSP on the horizontal axis. It is a shift map in which a number line and a downshift upper limit rpm line are written. That is, although it is a manual shift map, it does not have a fixed speed ratio line, and the greatest feature is that an infinite number of fixed speed ratio lines can be drawn. Then, gear ratio control is performed based on the map position of the operating point (VSP, APO) in the manual shift map M2 and the shift request operation (shift-up request operation, shift-down request operation) by the driver.

Here, the minimum engine speed line defines the minimum engine speed that must be maintained to prevent engine stall as the input engine speed to the variator 4 (=actual primary engine speed Npri=engine engine speed Ne). This is the rpm line. Therefore, when the operating point (VSP, APO) shifts to the minimum rotation speed line in the manual shift map M2, the flexible manual shift control unit 803 performs stepless shift control of the variator 4 according to changes in the vehicle speed VSP. Maintain a minimum number of revolutions.

The upshift upper limit rotation speed line of the manual shift map M2 is the primary rotation speed line that defines the maximum input rotation speed of the variator 4 when the driver requests an upshift. The downshift upper limit rotation speed line of the manual shift map M2 is a primary rotation speed line that defines the maximum input rotation speed of the variator 4 when the driver requests a downshift. Therefore, the upper limit rotation speed in upshift control by flexible manual shift control section 803 is limited by the upshift upper limit rotation speed, and the upper limit rotation speed in downshift control is limited by the downshift upper limit rotation speed. As a countermeasure against busy shifts that prevent frequent repetition of upshifts and downshifts, the upshift upper limit rpm line is set to a transmission input rpm range that is higher than the downshift upper limit rpm line. It has hysteresis.

For example, when the accelerator is released at operating point A in FIG. 4 while the "manual shift mode" is selected, coasting deceleration is performed along the fixed gear ratio line determined by operating point A, and the operation of FIG. Suppose that the minimum rotation speed line is reached at point B. In this case, from the operating point B, the fixed gear ratio control is shifted to the continuously variable transmission control in the downshift direction so as to maintain the minimum engine speed. Then, when the accelerator depression operation is performed at the operating point C during the stepless speed change, the control to maintain the gear ratio at the time of the accelerator depression operation (the fixed gear ratio determined by the operating point C) is executed.

That is, when the accelerator is depressed during the stepless speed change that maintains the minimum engine speed, the stepless speed change control is shifted to the fixed gear ratio control determined by the operating point (VSP, APO) at the timing of the accelerator stepping operation. In other words, regardless of the position of the operating point (VSP, APO) at the accelerator depression operation timing, a fixed gear ratio line passing through the operating point (VSP, APO) and the zero operating point is drawn. Similarly, during an upshift while the "manual shift mode" is selected, the operating point (VSP, APO) at the end of the upshift when the input speed has decreased by a predetermined upshift amount and the zero operating point. A fixed transmission ratio line is drawn. In addition, when downshifting while the "manual gear shift mode" is selected, the operating point (VSP, APO) at the end of the downshift when the input speed increases by a predetermined amount of downshifting and a fixed point that passes through the zero operating point. A gear ratio line is drawn.

The flexible manual shift control unit 803 adjusts the rotation step (re-acceleration waiting rotation step ΔNreacc) of the input rotation speed to be increased by the downshift due to the downshift request operation immediately after the shift from driving to the accelerator foot release operation. It is set to be smaller than the rotation step (coast-down rotation step ΔNCD) due to the shift-down request operation after a predetermined time has passed since the transition to .

That is, the rotation step in the transition scene from the driving to the accelerator foot release operation has a relationship of (re-acceleration waiting rotation step ΔNreacc)<(coast down rotation step ΔNCD).

Here, "driving running" means driving running while transmitting the driving force from the driving power source for overcoming the running resistance to the drive wheels by depressing the accelerator. Note that "coasting" refers to inertia running in which the vehicle travels according to vehicle inertia while the drive wheels receive drive system load resistance when the accelerator pedal is released. In other words, the running mode of the vehicle is divided into two running modes (drive running and coasting) that are handled differently in shift control depending on whether or not the accelerator is operated by the driver.

Flexible manual shift control unit 803 regards a select operation by the driver from the "continuously variable shift mode" to the "manual shift mode" as a downshift request operation.

In other words, the driver's downshift request operation in the "manual shift mode" or the driver's select operation to the "manual shift mode" is treated as a downshift request operation.

The flexible manual shift control unit 803 sets the coast determination time for the continuation of the foot release state from the start of the accelerator release when the accelerator is released during driving. Then, if there is a shift down request operation while the elapsed time from the start of accelerator foot release is less than the coasting determination time, the shift down request operation in the re-acceleration standby mode is performed. When a downshift request operation is performed after the elapsed time from the start of releasing the accelerator foot becomes equal to or longer than the coast determination time, the downshift request operation is performed in the coast down mode.

That is, before and after the shift down request operation immediately after the transition from driving to the accelerator foot release operation and the shift down request operation after the lapse of a predetermined time from the transition to the accelerator foot release operation, with the coast determination time as the boundary condition. Separated by timing.

Flexible manual shift control section 803 sets the rotation step difference due to the downshift request operation in the re-acceleration standby mode as the re-acceleration standby rotation step difference ΔNreacc. Then, the re-acceleration standby rotation step ΔNreacc is set to a value of a downshift amount capable of assisting re-acceleration in preparation for the driver's request for re-acceleration after releasing the accelerator pedal.

That is, the "downshift amount capable of assisting re-acceleration" refers to a rotational step that provides an increase in the engine speed Ne for assisting re-acceleration while suppressing the effectiveness of engine braking due to downshifting.

Flexible manual shift control section 803 sets the rotation step difference due to the shift down request operation in the coast down mode as coast down rotation step difference ΔNCD. Then, the coast down rotation step ΔNCD is set to a value of a downshift amount that can assist the deceleration of the vehicle in response to the deceleration request of the driver.

That is, the "downshift amount capable of assisting the deceleration of the vehicle" is the engine brake (load resistance force) acting on the drive wheels, and the engine brake is highly effective enough to assist the deceleration of the vehicle by the coast downshift. It means a step.

Flexible manual shift control unit 803 sets the coast-down rotational step difference ΔNCD_1 resulting from the first shift-down request operation in the coast-down mode to the value of the downshift amount that provides engine braking toward vehicle deceleration. The coast down rotation steps ΔNCD_2, ΔNCD_3, .

Flexible manual shift control section 803 maintains the gear ratio determined by the map position of the operating point (VSP, APO) at the end of the downshift when the downshift based on the downshift request operation by the driver is completed.

[Flexible manual shift control processing configuration]
FIG. 5 shows the flow of flexible manual shift control processing executed by the flexible manual shift control section 803 of the shift controller 800 when the driver performs a downshift request operation with the accelerator foot released. Each step in FIG. 5 will be described below. It should be noted that the flexible manual shift control process of FIG. 5 is repeatedly executed at a predetermined control cycle.

In step S1, it is determined whether or not the driver has released the accelerator pedal during running following the start. In the case of YES (accelerator OFF), the process proceeds to step S2, and in the case of NO (accelerator ON), the process proceeds to step S16. Here, the accelerator foot release operation by the driver is determined by the accelerator opening sensor value from the accelerator opening sensor 90 being a value indicating the accelerator opening=0.

In step S2, following the determination in step S1 that the accelerator is OFF, a timer for measuring the duration of the accelerator OFF is counted up, and the process proceeds to step S3.

In step S3, following the timer count-up in S2, it is determined whether or not the timer value after the count-up is equal to or greater than a predetermined value. If YES (timer value≧predetermined value), proceed to step S9. If NO (timer value<predetermined value), proceed to step S4. Here, the "predetermined value" is a coast determination threshold value for determining whether coasting is caused by the driver's accelerator pedal release operation based on the duration of the accelerator OFF.

In step S4, following the judgment in S3 that the timer value<predetermined value, the mode is changed to the re-acceleration standby mode, and the process proceeds to step S5.

In step S5, following the transition to the re-acceleration standby mode in S4, it is determined whether or not the operation is a D→M select operation or a downshift operation. If YES (D→M select or shift down operation), proceed to step S6, and if NO (not D→M select or shift down operation), proceed to END.

In step S6, following the determination in step S5 of the D→M select or shift down operation, it is regarded as an operation to prepare for re-acceleration, and the re-acceleration standby rotation step ΔNreacc is reduced as a downshift amount so that acceleration can be assisted. shift, and proceed to step S7.

Here, the re-acceleration standby rotational step ΔNreacc is set to a value of a downshift amount capable of assisting re-acceleration in preparation for a driver's request for re-acceleration after releasing the accelerator pedal. In other words, when the "re-acceleration standby rotational speed difference ΔNreacc" is given as a variable value, re-acceleration can be assisted regardless of factors that change the effectiveness of the engine braking (for example, the gear ratio of the variator 4, the vehicle speed VSP, the road surface gradient, etc.). Calculate the downshift amount value. Note that the "re-acceleration standby rotation step ΔNreacc" may be given as a fixed value that is preset based on a large number of experimental data. ΔNCD_1”.

In step S7, following execution of the downshift control in the "manual shift mode" in S6, S11, or S14, whether or not the actual primary rotation speed Npri has reached the rotation speed increase end point up to the target rotation step at that time. to judge whether In the case of YES (the end point of the increase in the rotation speed has been reached), the process proceeds to step S8, and in the case of NO (the end point of the increase in the rotation speed has not been reached), the determination in step S7 is repeated.

In step S8, following the determination in step S7 that the rotational speed increase end point has been reached, the fixed gear ratio determined by the straight line connecting the zero operating point and the rotational speed increase end point (VSP, APO) is set as the target gear ratio, Execute fixed gear ratio control of the variator 4 to maintain the target gear ratio, and proceed to the end.

In step S9, following the judgment in S3 that the timer value≧predetermined value, the mode is changed to the coast down mode, and the process proceeds to step S10.

In step S10, following the transition to the coast down mode in S9, it is determined whether or not it is the first D→M select operation or the first shift down operation. If YES (first D→M select operation or first downshift operation), proceed to step S11; if NO (not first D→M select operation or first downshift operation), step S12. proceed to

In step S11, following the determination in step S10 that this is the first D→M select operation or downshift operation, the first time is regarded as an engine brake request operation for deceleration, and the coast down rotation step ΔNCD_1 is the amount of downshift. downshift as much as possible. From step S11, the process proceeds to step S7.

Here, the "coast down rotation step ΔNCD_1" is the rotation step of the input rotation speed to be increased by the downshift due to the first shift down request operation, and based on the driver's engine brake request, the downshift that provides the engine brake toward the vehicle deceleration. Set to the amount value. That is, when the "coast-down rotation step difference ΔNCD_1" is given by a variable value, the engine braking toward vehicle deceleration is applied regardless of the variable factors of the feeling of engine braking deceleration (for example, the gear ratio of the variator 4, the vehicle speed VSP, the road surface gradient, etc.). Calculate the amount of downshift to give. Therefore, the higher the gear ratio of the variator 4, the larger the calculated value. As the vehicle speed VSP increases, a larger value is calculated. A larger value is calculated as the slope of the downhill road increases. It should be noted that the "coast-down rotation step ΔNCD_1" may be given as a fixed value preset based on a large number of experimental data. set to a value higher than the coast-down rotation step ΔNCD_3, . . .

In step S12, following the determination in S10 that the D→M select operation or the downshift operation is not the first time, it is determined whether or not the "manual shift mode" has been selected. If YES (selection of "manual speed change mode"), proceed to step S13, and if NO (selection of "continuously variable speed mode"), proceed to step S15.

In step S13, following the determination in S12 that the "manual shift mode" has been selected, it is determined whether or not there has been a second or subsequent downshift operation. If YES (there is a second or subsequent downshift operation), the process proceeds to step S14, and if NO (the second or subsequent downshift operation is not performed), the process proceeds to END.

In step S14, following the determination in step S13 that there is a downshift operation after the second time, the second and subsequent downshift operations are regarded as enjoying or for fine adjustment of the engine brake, and the coast down is smaller than the first time. The rotational steps ΔNCD_2, ΔNCD_3, . . . are downshifted by small amounts. From step S14, the process proceeds to step S7.

Here, the "coast-down rotation steps ΔNCD_2, ΔNCD_3, . is set to the value of the amount of downshift to be fine-tuned. That is, when the "coast-down rotation steps ΔNCD_2, ΔNCD_3, . Set to a value lower than the step ΔNCD_1”. It should be noted that the "coast-down rotation steps ΔNCD_2, ΔNCD_3, . ratio, vehicle speed VSP, road slope, etc.) to calculate the amount of downshift to fine-tune the engine brake.

In step S15, following the determination in S12 that the "continuously variable speed mode" was selected, the counter value of the down operation frequency counter is reset, and the process proceeds to END.

In step S16, following the determination in step S1 that the accelerator is ON, the timer for measuring the duration of the accelerator OFF is cleared to zero (reset), and the process proceeds to step S15.

Next, "Background technology and problem-solving measures" will be explained. The operation of the first embodiment will be described separately for "flexible manual shift control processing operation" and "manual downshift operation during accelerator foot release".

[Background technology and problem-solving measures]
A manual stepped shift map used in the background art "manual shift mode" has, for example, a plurality of manual shift speeds (for example, M1 speed to M5 speed) by fixed speed ratio lines, as shown in FIG. Use shift map. When there is a shift-up request by the driver's shift operation (lever operation, switch operation, etc.), the manual gear stage that is one higher than the manual gear stage selected at that time is selected. Also, when there is a shift-down request by the driver's shift operation, the manual gear stage that is one lower than the manual gear stage selected at that time is selected.

For example, when the M2 speed is selected and the operating point D is operated by the driver to request an upshift, the operating point D is shifted to the operating point E and the M3 speed is selected. On the other hand, when the M4 speed is selected and the operating point F is operated by the driver to request a shift down, the operating point moves from the operating point F to the operating point G and the M3 speed is selected.

In this background art, when shifting from drive driving to accelerator foot release operation, the same rotational step occurs when the shift down request operation is performed immediately after the transition and when the shift down request operation is performed after a predetermined time has elapsed from the transition. A downshift is executed. In other words, regardless of whether the operation timing of the downshift request after shifting from driving to accelerator foot release operation is early or late, a preset fixed gear ratio line (for example, M1 speed line to M5 speed line) line) is used as a downshift amount to increase the input rotation speed.

For example, in the background art, as shown by the thick solid line in FIG. 7, when the drive operation by selecting the "continuously variable speed mode" shifts to the accelerator foot release operation, the operation point J1 in the drive operation is shifted from the operating point J1 on the minimum rotation speed line. Move to J2. Immediately after that, when there is a select operation to the "manual shift mode" at the operating point J3, if there is a request to downshift to the M3 speed stage, the input rotation speed increases from the operating point J3 to the operating point J4, and then , and M3 while maintaining the gear ratio.

In this way, when there is a shift down request operation immediately after the shift to the accelerator foot release operation, a large rotation step from the operating point J3 to the operating point J4 is set as the rotation step, and the downshift in the coast state causes the engine Raise the rpm significantly. As a result, the effectiveness of the engine braking becomes stronger, and when the driver requests reacceleration by depressing the accelerator after the downshift, the feeling of reacceleration that responds to the reacceleration request cannot be obtained.

On the other hand, in the background art, as shown by the thick dashed line in FIG. 7, when the driving operation by selecting the "continuously variable speed mode" shifts to the accelerator foot release operation, the operating point J1 in the driving operation is shifted from the operating point J1 on the minimum rotation speed line. Move to J2. Then, when there is a select operation to the "manual shift mode" at the operating point J5 after a predetermined time has elapsed since the shift to the operating point J2, it is determined that the request is for a shift down to the M3 speed stage, and the operating point J5 The input speed increases up to the operating point J6, and then the speed is reduced while maintaining the gear ratio of the M3 speed stage. Further, when a shift down request operation to the M2 speed stage is performed at the operating point J7, the input rotation speed increases from the operating point J7 to the operating point J8, and then decelerates while maintaining the gear ratio of the M2 speed stage. . Further, when a shift down request operation to the M1 speed stage is performed at the operating point J9, the input rotation speed increases from the operating point J9 to the operating point J10, and then decelerates while maintaining the gear ratio of the M1 speed stage.

In this way, when there is a shift-down request operation after a predetermined time has elapsed since the shift to the accelerator foot release operation, small rotation steps between the operating points J5 to J6, J7 to J8, and J9 to J10 are set as the rotation steps. be. Therefore, even if the downshift request operation is repeated multiple times, the amount of increase in the engine speed due to the downshift in the coasting state can be kept low. Therefore, the effect of the engine braking cannot be expected, and the feeling of deceleration that meets the engine brake deceleration request by the driver's downshift cannot be obtained.

As a result, in the background art, when a downshift request operation is performed immediately after the accelerator foot is released, the rotation step (downshift amount) becomes large, and the feeling of reacceleration that responds to the driver's reacceleration request cannot be obtained. . On the other hand, when a shift-down request operation is performed after a predetermined time has passed since the accelerator foot is released, the rotational step (downshift amount) becomes small, and there is a problem that the deceleration feeling that responds to the driver's deceleration request cannot be obtained. rice field.

In order to solve the above problem, the inventors of the present invention can regard the shift-down request operation immediately after the shift to the accelerator foot release operation as an operation to prepare for re-acceleration. On the other hand, attention was focused on the fact that a shift-down request operation after a predetermined time has passed since the transition to the accelerator foot release operation can be regarded as an engine brake request operation for deceleration. Based on this focus, a transmission control device for a belt-type continuously variable transmission CVT has a variator 4 mounted in a drive system from the engine 1 to the drive wheels 6 and includes a transmission controller 800 that controls the transmission gear ratio of the variator 4 . When the "manual shift mode" is selected, the shift controller 800 uses the manual shift map M2 that does not have a fixed gear ratio line to set the gear ratio based on the map position of the operating point (VSP, APO) and the shift request operation by the driver. It has a flexible manual shift control section 803 for control. The flexible manual shift control unit 803 adjusts the re-acceleration standby rotation difference ΔNreacc of the input rotation speed to be increased by the downshift due to the downshift request operation immediately after the transition from the driving to the accelerator foot release operation from the transition to the accelerator foot release operation. A countermeasure to solve the problem is adopted, which is set to be smaller than the coast-down rotational step ΔNCD caused by the shift-down request operation after the lapse of a predetermined time.

That is, when using the manual shift map M2 that does not have a fixed gear ratio line when the "manual gear shift mode" is selected, the rotation step of the input rotation speed to be increased by downshifting can be flexibly changed without being restricted by the fixed gear ratio line. Can be set. The flexible manual shift control unit 803 utilizes this flexibility in setting the rotation step, and when shifting from driving to accelerator pedal release operation, the rotation step in response to the downshift request operation by the driver is changed immediately after the transition and from the transition. It is set differently after a predetermined time has elapsed. Focusing on the point that the shift-down request operation immediately after the shift can be regarded as an operation to prepare for re-acceleration, the re-acceleration standby rotation step ΔNreacc is set smaller than the coast-down rotation step ΔNCD. On the other hand, focusing on the fact that a shift down request operation after a predetermined time has passed since the shift can be regarded as an engine brake request operation for deceleration, the coast down rotation step difference ΔNCD is set larger than the re-acceleration standby rotation step difference ΔNreacc. ing.

Therefore, in the downshift in response to the downshift request operation immediately after the transition from driving to the accelerator pedal release operation, the reacceleration standby rotational difference ΔNreacc (downshift amount) becomes small, and a feeling of reacceleration in response to the driver's reacceleration request is obtained. be done. On the other hand, in the downshift in response to the downshift request operation after a predetermined time has passed since the transition from driving to the accelerator pedal release operation, the coast down rotation step ΔNCD (downshift amount) increases, and the deceleration feeling that responds to the driver's deceleration request is increased. can get. Therefore, in the scene of transition from driving to accelerator pedal release operation, both the feeling of reacceleration in response to the driver's request for reacceleration and the deceleration feeling in response to the driver's deceleration request can be achieved.

[Flexible manual shift control processing action]
Flexible manual shift control processing performed by the flexible manual shift control unit 803 when the driver requests a downshift while the accelerator is released will be described with reference to the flowchart shown in FIG.

First, when the driver starts releasing the accelerator pedal during driving, S1→S2→S3→S4→S5→End while the timer value representing the duration from the start of the accelerator pedal releasing operation is less than a predetermined value. The flow is repeated. In S4, a transition is made to a re-acceleration standby mode. In S5, it is determined whether the operation is a D→M select operation or a downshift operation.

In S5, if it is determined that the operation is a D→M select operation or a downshift operation, the process proceeds from S5 to S6→S7. In S6, it is regarded as an operation for preparing for reacceleration, and shift control is executed to downshift by reducing the reacceleration standby rotation step difference ΔNreacc as a downshift amount so as to assist the acceleration. In S7, it is determined whether or not the actual primary rotation speed Npri has reached the rotation speed increase end point to the target rotation step (=re-acceleration standby rotation step ΔNreacc) at that time.

In S7, when it is determined that the end point of increasing the rotational speed has been reached, the process proceeds from S7 to S8→end. In step S8, a fixed gear ratio determined by a straight line connecting the zero operating point and the operating point (VSP, APO) at which the rotational speed increases is set as the target gear ratio, and fixed gear ratio control of the variator 4 is executed to maintain the target gear ratio. be.

On the other hand, when the timer value indicating the duration from the start of the accelerator foot release operation reaches or exceeds a predetermined value, the process proceeds to S1→S2→S3→S9→S10. In S9, a transition is made to the coast down mode. In S10, it is determined whether or not the D→M select operation or the downshift operation is performed for the first time.

In S10, when it is determined that the D→M select operation or the first shift down operation is performed, the process proceeds from S10 to S11→S7. In S11, the first time is regarded as an engine brake request operation for deceleration, and the speed change control is executed to perform a large downshift using the coast down rotation step difference ΔNCD_1 as the downshift amount. In S7, it is determined whether or not the actual primary rotation speed Npri has reached the rotation speed increase end point due to the target rotation step (=coast-down rotation step ΔNCD_1) at that time.

If it is determined in S7 that the rotational speed increase end point has been reached, the process proceeds from S7 to S8→END. In S8, the fixed gear ratio determined by the straight line connecting the zero operating point and the operating point (VSP, APO) at which the rotational speed is increasing is set as the target gear ratio, and the fixed gear ratio control of the variator 4 is executed to maintain the target gear ratio. be done.

Then, after the first downshift control in the coast down mode is executed and while the second and subsequent downshift operations are not performed, S1→S2→S3→S9→S10→S12→S13→end. The flow to progress is repeated. After that, when the second shift down operation is performed, the process proceeds from S13 to S14→S7. In S14, the second and subsequent downshift operations are regarded as an operation for enjoying the downshift operation or an operation for fine adjustment of the engine brake, and shift control is executed in which the coast down rotational step difference ΔNCD_2 is set to be a downshift amount smaller than that of the first shift. In S7, it is determined whether or not the actual primary rotation speed Npri has reached the rotation speed increase end point due to the target rotation step (=coast-down rotation step ΔNCD_2) at that time.

If it is determined in S7 that the rotational speed increase end point has been reached, the process proceeds from S7 to S8→end. In S8, the fixed gear ratio determined by the straight line connecting the zero operating point and the operating point (VSP, APO) at which the rotational speed is increasing is set as the target gear ratio, and the fixed gear ratio control of the variator 4 is executed to maintain the target gear ratio. be done.

When the third downshift operation is performed, the process proceeds from S13 to S14→S7. In S14, the second and subsequent downshift operations are regarded as enjoying the downshift operation or as an operation for fine adjustment of the engine brake, and the coast down rotation step difference ΔNCD_3 is made smaller than the first downshift amount. In S7, it is determined whether or not the actual primary rotation speed Npri has reached the rotation speed increase end point due to the target rotation step (=coast-down rotation step ΔNCD_3) at that time.

If it is determined in S7 that the rotational speed increase end point has been reached, the process proceeds from S7 to S8→end. In S8, the fixed gear ratio determined by the straight line connecting the zero operating point and the operating point (VSP, APO) at which the rotational speed is increasing is set as the target gear ratio, and the fixed gear ratio control of the variator 4 is executed to maintain the target gear ratio. be done.

When the fourth and subsequent downshift operations are performed, similarly to the case of the second and third downshift operations, the primary rotation speed Npri at that time has a rotation step difference ΔNCD_4, . . . (<ΔNCD_1). is executed.

In this way, the flexible manual shift control that is executed when the vehicle shifts from driving to accelerator pedal release and the driver performs a downshift request operation in the accelerator pedal release state has the following characteristics.
・The rotation step (re-acceleration waiting rotation step ΔNreacc) to be increased by the downshift due to the downshift request operation immediately after the transition from driving to the accelerator foot release operation is set for a predetermined time after the transition to the accelerator foot release operation. It is set to be smaller than the rotation step (coast down rotation step ΔNCD) due to the subsequent downshift request operation (S6, S11).
・The selection operation by the driver from the "continuously variable speed mode" to the "manual speed change mode" is regarded as a downshift request operation (S5, S10).
When the accelerator foot is released during driving, a coast determination time is set for the continuation of the foot-released state from the start of the accelerator foot release (S3).
If there is a shift-down request operation while the elapsed time from the start of accelerator foot release is less than the coasting determination time, the shift-down request operation is performed in the re-acceleration standby mode (S4).
If there is a shift-down request operation after the elapsed time from the start of accelerator foot release is equal to or longer than the coast determination time, the shift-down request operation is performed in the coast down mode (S9).
・The rotation step due to the downshift request operation in the re-acceleration standby mode is set as the re-acceleration standby rotation step ΔNreacc, and the re-acceleration standby rotation step ΔNreacc can be used to assist the re-acceleration in preparation for the driver's request for re-acceleration after the accelerator pedal is released. It is set to the value of the downshift amount (S6).
・The rotation step caused by the shift down request operation in the coast down mode is set as the coast down rotation step ΔNCD, and the coast down rotation step ΔNCD is set to a value of the downshift amount that can assist the deceleration of the vehicle in response to the driver's deceleration request ( S11, S14).
- The coast down rotation step difference ΔNCD_1 resulting from the first shift down request operation in the coast down mode is set to the value of the downshift amount that provides the engine brake for decelerating the vehicle (S11).
The coast-down rotational steps ΔNCD_2, ΔNCD_3, .
When the downshift based on the downshift request operation by the driver is completed, the gear ratio determined by the map position of the operating point (VSP, APO) at the end of the downshift is maintained (S7→S8).

[Manual downshift action during accelerator foot release]
The manual downshift operation when the driver performs the select operation immediately after the accelerator is released and the driver performs the select operation and the downshift request operation twice after coasting determination will be described with reference to FIGS. 8 and 9. FIG.

A section from time 0 to time t1 in FIG. 8 is a driving section in which the vehicle is driven while maintaining the vehicle speed VSP and the target primary rotation speed Npri ^* while the "continuously variable speed mode" is selected. A driving section (0 to t1) corresponds to the operating point H0 in FIG.

Time t1 in FIG. 8 is the accelerator foot release operation time at which the target primary rotation speed Npri ^* is reduced to the minimum rotation speed while maintaining the vehicle speed VSP. The accelerator foot release operation time t1 corresponds to the movement from the operating point H0 to the operating point H1 in FIG.

A section from time t1 to time t2 in FIG. 8 is a coast deceleration section in which the target primary rotation speed Npri ^* is kept at the minimum rotation speed by the stepless speed change of the variator 4 and coast deceleration travel is performed. The coast deceleration zone (t1 to t2) corresponds to movement from the operating point H1 to the operating point H2 in FIG.

Time t2 in FIG. 8 is the time of selection operation to the "manual shift mode", and the re-acceleration standby mode in which the target primary rotation speed Npri ^* based on the minimum rotation speed is increased by the downshift amount of the re-acceleration standby rotation step ΔNreacc. manual downshift time. The manual downshift time t2 in this re-acceleration standby mode corresponds to the movement from the operating point H2 to the operating point H3 in FIG.

The section from time t2 to time t4 in FIG. 8 is a coast deceleration running section in which the gear ratio of the variator 4 is maintained at the gear ratio at the end of the downshift after the manual downshift in the re-acceleration standby mode is completed. is. The coasting deceleration zone (t2 to t4) corresponds to the movement from the operating point H3 to the operating point H4 in FIG. It is the connecting line. Note that time t3 in the course of the coasting deceleration zone (t2 to t4) is the coast determination time when the accelerator foot is released for a predetermined period of time from the accelerator foot release operation time t1.

Time t4 in FIG. 8 is the select operation time from the "manual transmission mode" to the "continuously variable transmission mode", and the target primary rotation speed Npri ^* is reduced to the minimum rotation speed corresponding to coasting. Time. This coast deceleration return time t3 corresponds to the movement from the operating point H4 to the operating point H5 in FIG.

A section from time t4 to time t5 in FIG. 8 is a coast deceleration section in which the target primary rotation speed Npri ^* is kept at the minimum rotation speed by the stepless speed change of the variator 4 and coast deceleration travel is performed. The coast deceleration zone (t4 to t5) corresponds to movement from operating point H5 to operating point H6 in FIG.

Time t5 in FIG. 8 is the select operation time to the "manual shift mode", and the target primary rotation speed Npri ^* at the minimum rotation speed is increased by the downshift amount of the coastdown rotation step ΔNCD_1 in the coast down mode. This is the first manual downshift time. The first manual downshift time t5 in the coast down mode corresponds to the movement from the operating point H6 to the operating point H7 in FIG.

A section from time t5 to time t6 in FIG. 8 is a coast deceleration section in which the gear ratio of the variator 4 is maintained at the gear ratio at the end of the downshift after the first manual downshift. The coasting deceleration zone (t5 to t6) corresponds to the movement from the operating point H7 to the operating point H8 in FIG. It is the connecting line.

Time t6 in FIG. 8 is the shift-down request operation time by the driver in the "manual gear shift mode", and the second manual shift is performed to increase the primary rotation speed Npri ^* at that time by the downshift amount of the coast-down rotation step ΔNCD_2. Downshift time. The second manual downshift time t3 in the coast down mode corresponds to the movement from the operating point H8 to the operating point H9 in FIG.

A section from time t6 to time t7 in FIG. 8 is a coast deceleration section in which the gear ratio of the variator 4 is maintained at the gear ratio at the end of the downshift after the second manual downshift. The coasting deceleration zone (t6 to t7) corresponds to the movement from the operating point H9 to the operating point H10 in FIG. It is the connecting line.

Time t7 in FIG. 8 is the time when the driver performs a downshift request operation in the "manual shift mode", and the third manual downshift at which the primary rotation speed Npri ^* at that time is increased by the downshift amount of the rotation step ΔNCD_3. Time. The third manual downshift time t7 in the coast down mode corresponds to the movement from the operating point H10 to the operating point H11 in FIG.

A section after time t7 in FIG. 8 is a coast deceleration section in which the gear ratio of the variator 4 is maintained at the gear ratio at the end of the downshift after the third manual downshift. The coasting deceleration zone (from t7) corresponds to movement along the fixed gear ratio line α4 from the operating point H11 in FIG. A line that connects the points.

Thus, when the driver performs a select operation from the "continuously variable speed mode" to the "manual speed change mode" at time t2, the select operation is regarded as a downshift request operation in the re-acceleration standby mode. Therefore, in preparation for a reacceleration request by the driver depressing the accelerator after the select operation, a manual downshift is executed by downshifting the reacceleration standby rotation step ΔNreacc to a small downshift amount so as to assist reacceleration.

On the other hand, when the driver performs a select operation from the "continuously variable speed mode" to the "manual speed change mode" at time t5, the select operation is regarded as the first shift down request operation in the coast down mode. Therefore, in response to the driver's request for deceleration, a manual downshift is executed to increase the coast down rotation step ΔNCD_1 as a downshift amount so as to increase the effectiveness of the engine brake and assist the deceleration.

In the coast down mode, the coast down rotation step ΔNCD_1 of the input rotation speed to be increased by the downshift due to the first downshift request operation is set to the downshift amount that gives the engine brake toward vehicle deceleration based on the driver's engine brake request. set to a value. That is, as shown in FIG. 9, the coast-down rotational step ΔNCD_1 is set to a rotational step that can be obtained with a large gear ratio width in the first downshift from the fixed gear ratio line α1 to the fixed gear ratio line α2.

Therefore, in response to the first shift-down request operation during coasting deceleration, the engine speed Ne is increased at once by the width of the rotation step ΔNCD_1 to increase the load resistance of the engine 1, thereby securing the effectiveness of the engine braking. . Therefore, it is possible to produce a feeling of a stepped downshift by a certain action and a certain reaction to the first downshift request operation.

Furthermore, in the coast down mode, the engine brake is slightly reduced based on the driver's request for a shift down operation feeling request for the coast down rotation step ΔNCD_2, ΔNCD_3, etc. of the input rotation speed to be increased by the downshift due to the second and subsequent downshift request operations. It is set to the value of the downshift amount to be adjusted. That is, as shown in FIG. 9, the coast-down rotation step ΔNCD_2 is set to a rotation step obtained with a gear ratio width narrower than that of the first downshift from the fixed gear ratio line α2 to the fixed gear ratio line α3. there is As shown in FIG. 9, the coast-down rotation step ΔNCD_3 is set to a rotation step obtained from a fixed gear ratio line α3 to a fixed gear ratio line α4 with a gear ratio width narrower than that of the first downshift.

Therefore, during coast deceleration in which a feeling of coasting deceleration is obtained by the first downshift, the engine speed Ne is increased by the range of the rotation step ΔNCD_2 and the rotation step ΔNCD_3 for the second and subsequent downshift request operations, and the engine 1 By slightly increasing the load resistance of the engine, the amount of fine adjustment of the emblem is secured. Therefore, the engine brake fine adjustment that occurs each time a downshift request operation suppresses the performance of the stepped downshift feeling compared to the first downshift request operation, so that the driver's request for a downshift operation feeling can be met.

In addition, by making the amount of downshifting different between the first and second downshift requests made by the driver, deceleration control that matches the driver's intentions can be achieved depending on the number of times the driver performs a downshift request, increasing the sense of driving enjoyment. can also enjoy

As described above, the shift control device for the belt-type continuously variable transmission CVT of the first embodiment provides the following effects.

(1) A continuously variable transmission (belt type continuously variable transmission) equipped with a variator 4 in the drive system from the driving source (engine 1) to the driving wheels 6 and equipped with a shift controller 800 for controlling the gear ratio of the variator 4 CVT) transmission control device,
When the manual shift mode is selected, the shift controller 800 selects not a plurality of fixed gear ratios set in advance, but based on the shift request operation by the driver. has a flexible manual shift control unit 803 that performs gear ratio control to shift the gear ratio of the variator 4 to the target input rotation speed having
When the flexible manual shift control unit 803 detects an accelerator foot release operation in a driving state, the rotation step difference (re-acceleration waiting rotation step difference ΔNreacc) set by the downshift request operation before a predetermined time has passed since the detection is It is set to be smaller than the rotation step (coast-down rotation step ΔNCD) set by the shift-down request operation after the lapse of a predetermined time.
Therefore, in the scene of transition from driving to accelerator pedal release operation, both the feeling of reacceleration in response to the driver's request for reacceleration and the deceleration feeling in response to the driver's deceleration request can be achieved.

(2) The flexible manual shift control unit 803 regards the selection operation by the driver from the "continuously variable shift mode" to the "manual shift mode" as a downshift request operation.
For this reason, if the driver selects the "manual transmission mode" with the intention of reaccelerating immediately after shifting from driving in the "continuously variable transmission mode" to releasing the accelerator pedal, the input rotation speed will increase and the driver will You can get the feeling of acceleration intended by Also, during coast deceleration by selecting the "continuously variable transmission mode", if you select the "manual transmission mode" with the intention of downshifting deceleration, the engine brake will work and the driver will get the feeling of deceleration that the driver intended. can.

(3) The flexible manual gear shift control unit 803 sets a coast determination time by the continuation of the foot release state from the start of the accelerator release when the accelerator foot is released during driving,
If there is a shift-down request operation while the elapsed time from the start of accelerator foot release is less than the coasting determination time, the shift-down request operation is performed in the re-acceleration standby mode,
When a downshift request operation is performed after the elapsed time from the start of releasing the accelerator foot becomes equal to or longer than the coast determination time, the downshift request operation is performed in the coast down mode.
Therefore, immediately after the transition from driving to the accelerator foot release operation and after a predetermined time has elapsed from the transition can be divided into sections before and after the coast determination time as a reference.

(4) The flexible manual shift control unit 803 sets the rotation step difference due to the downshift request operation in the re-acceleration standby mode as the re-acceleration standby rotation step difference ΔNreacc,
The re-acceleration standby rotation step ΔNreacc is set to a value of a downshift amount capable of assisting re-acceleration in preparation for the driver's request for re-acceleration after releasing the accelerator pedal.
Therefore, by appropriately setting the re-acceleration standby rotation step ΔNreacc, the control increases the input rotation speed (=engine rotation speed Ne) while suppressing vehicle deceleration, resulting in good response when the driver requests re-acceleration. You can feel the acceleration.

(5) The flexible manual shift control unit 803 sets the rotation step difference due to the shift down request operation in the coast down mode as the coast down rotation step difference ΔNCD,
The coast down rotation step difference ΔNCD is set to a value of a downshift amount that can assist the deceleration of the vehicle in response to the driver's deceleration request.
Therefore, by appropriately setting the coast-down rotation step ΔNCD, the load on the drive source (engine 1) increases as the coast rotation speed rises, thereby promoting vehicle deceleration and providing a sense of deceleration that meets the driver's deceleration request. be able to.

(6) having an engine 1 as a drive source for running;
The flexible manual shift control unit 803 sets the coast-down rotational step difference ΔNCD_1 resulting from the first shift-down request operation in the coast-down mode to the value of the downshift amount that provides engine braking toward vehicle deceleration,
The coast down rotation steps ΔNCD_2, ΔNCD_3, .
Therefore, in the coast down mode, it is possible to give the driver a feeling of deceleration in response to the engine brake request for the first shift down request operation. In addition, it is possible to give the driver a feeling of deceleration that meets the downshift operation feeling request for the second and subsequent downshift request operations.

(7) When the downshift based on the downshift request operation by the driver is completed, the flexible manual shift control section 803 maintains the gear ratio determined by the operating point (VSP, APO map position) at the time of completion of the downshift.
Therefore, when the manual downshift is completed, the fixed gear ratio line passing through the operating point (VSP, APO) at the end is drawn on the manual gear shift map (manual gear shift map M2), and the control immediately shifts to the control that maintains the fixed gear ratio. can do.

The shift control device for a continuously variable transmission according to the present invention has been described above based on the first embodiment. However, the specific configuration is not limited to this first embodiment, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim of the scope of claims.

In the first embodiment, an example of having the "continuously variable speed mode" and the "manual speed change mode" is shown as the speed change mode. However, as long as at least the "manual shift mode" is included in the shift mode, even if the "continuously variable shift mode" is divided into the eco shift mode and the sports shift mode as other shift modes. good.

Embodiment 1 shows an example in which the shift control device of the present invention is applied to an engine vehicle equipped with a belt-type continuously variable transmission composed of a torque converter, a forward/reverse switching mechanism, a variator, and a final reduction mechanism. However, the shift control device of the present invention is not limited to a belt-type continuously variable transmission using only a variator, but is applicable to vehicles equipped with a belt-type continuously variable transmission with a sub-transmission in which a variator and a sub-transmission are connected in series. You can

1 engine (driving source for running)
CVT belt type continuously variable transmission (continuously variable transmission)
2 torque converter 3 forward/reverse switching mechanism 4 variator 5 final reduction mechanism 6 drive wheel 8 CVT control unit 800 shift controller 801 shift mode selector 802 stepless shift controller 803 flexible manual shift controller 804 solenoid command output unit 80 primary rotation sensor 81 vehicle speed sensor 84 inhibitor switch 87 shift mode selection switch 88 shift operation switch 9 engine control unit 90 accelerator opening sensor 91 engine rotation sensor M2 manual shift map

Claims (7)

A speed change control device for a continuously variable transmission, which is equipped with a variator in a drive system from a drive source for running to driving wheels, and includes a speed change controller for controlling a gear ratio of the variator,
When the manual shift mode is selected, the shift controller does not use a plurality of fixed gear ratios set in advance, but based on the shift request operation by the driver. a flexible manual shift control unit that performs gear ratio control to shift the gear ratio of the variator to a target input rotation speed having
When the flexible manual shift control unit detects an accelerator foot release operation in a driving state, the rotation step set by the shift down request operation before a predetermined time has passed since the detection is performed after the predetermined time has passed. A speed change control device for a continuously variable transmission, characterized in that the speed difference is set to be smaller than the speed difference set by the downshift request operation. In the shift control device for a continuously variable transmission according to claim 1,
A shift control device for a continuously variable transmission, wherein the flexible manual shift control unit regards a select operation by a driver from a continuously variable shift mode to the manual shift mode as the downshift request operation. In the shift control device for a continuously variable transmission according to claim 1 or 2,
The flexible manual shift control unit sets a coast determination time by continuing the foot release state from the start of the accelerator release when the accelerator foot is released during driving,
If there is a downshift request operation while the elapsed time from the accelerator foot release start is less than the coast determination time, the downshift request operation is performed in the re-acceleration standby mode,
Shift control for a continuously variable transmission, characterized in that if a downshift request operation is performed after the elapsed time from the start of releasing the accelerator pedal is equal to or greater than the coast determination time, the shift down request operation is performed in a coast down mode. Device. In the shift control device for a continuously variable transmission according to claim 3,
The flexible manual shift control unit treats a rotational step caused by a shift-down request operation in the re-acceleration standby mode as a re-acceleration standby rotational step,
A speed change control device for a continuously variable transmission, wherein the re-acceleration standby rotation step is set to a value of a downshift amount capable of assisting re-acceleration in preparation for a driver's re-acceleration request after releasing the accelerator pedal. In the shift control device for a continuously variable transmission according to claim 3 or 4,
The flexible manual shift control unit treats a rotation step caused by a shift down request operation in the coast down mode as a coast down rotation step,
A shift control device for a continuously variable transmission, wherein the coast down rotation step is set to a value of a downshift amount capable of assisting deceleration of a vehicle in response to a driver's deceleration request. In the shift control device for a continuously variable transmission according to claim 5,
Having an engine as the drive source for running,
The flexible manual shift control unit sets a coast-down rotation step due to a first shift-down request operation in the coast-down mode to a value of a downshift amount that provides engine braking toward vehicle deceleration,
A speed change control device for a continuously variable transmission, characterized in that a coast-down rotation step due to a second or subsequent shift-down request operation in the coast-down mode is set to a value of a downshift amount for finely adjusting an engine brake. In the shift control device for a continuously variable transmission according to any one of claims 1 to 6,
The flexible manual shift control unit maintains a gear ratio determined by a map position of an operating point at the end of the downshift when the downshift based on the downshift request operation by the driver is completed. gear control device.

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