JP4016822B2 - Shift control device for continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shift control device for a vehicle including a continuously variable transmission.
[0002]
[Prior art]
In conventional transmission control of a continuously variable transmission, a shift pattern according to the vehicle speed and the amount of accelerator operation is stored as a map of the target input shaft speed, and the target speed ratio is determined from the target input shaft speed according to the driving state. (See Japanese Patent Laid-Open No. 4-54371).
[0003]
In this conventional example, even if a kick-down operation is performed to increase the accelerator operation amount suddenly with the intention of sudden acceleration from a steady running state where the vehicle is traveling at a substantially constant vehicle speed with a relatively small accelerator operation amount, the accelerator operation amount at this time is reduced. Since it takes some time for the actual gear ratio to reach the corresponding target gear ratio, the driving force does not increase despite the engine speed increasing immediately, and the engine seems to be blown in the meantime. The driver feels uncomfortable. That is, the shift map is set as shown in FIG. 9B because the shift line is set for each accelerator operation amount so that good acceleration can be obtained at the start as shown in FIG. 9A. At the time of re-acceleration such as a simple kick-down operation, the amount of downshift becomes excessive, and a time lag occurs until the acceleration expected by the driver is obtained only by excessively increasing the engine speed.
[0004]
As a countermeasure, it is conceivable to suppress a change in the gear ratio when the acceleration request is large. For example, there is proposed a method in which the gear ratio is fixed when the throttle opening exceeds a threshold value (Japanese Patent No. 2593432). ). This means that the fixed gear ratio is determined by the gear ratio on the shift map when the throttle opening is the threshold value. In this way, by fixing the gear ratio before reaching a large gear ratio, an increase in engine rotation causes an increase in driving force quickly, so the time delay from when the throttle increases until a feeling of acceleration is obtained is shortened. As a result, the uncomfortable feeling is reduced and the acceleration response in the sense of sensation is improved.
[0005]
[Patent Document 1]
JP-A-4-54371
[Patent Document 2]
Japanese Patent No. 2593432
[0006]
[Problems to be solved by the invention]
However, in the latter conventional example (Japanese Patent No. 2593432), the speed ratio is kept constant unless the throttle opening is returned from the threshold value and the hysteresis setting, and the driver's initial acceleration intention is satisfied. Since there will be no change in the gear ratio after that, it will cause a sense of incongruity. In other words, in order to generate a change in the gear ratio, an operation to intentionally return the accelerator pedal to a large value is required, which causes a problem that drivability is lowered.
[0007]
As a countermeasure against this, it is conceivable to control the trajectory of the target input shaft speed with a time constant. However, during re-acceleration such as kick-down acceleration, the additional point increase at the initial stage of shifting is different for each driving condition. It is practically difficult to define the amount of increase in the target input shaft speed at the time, and since it is a function of time, it is extremely difficult to correspond to the increase in the vehicle speed and the increase in the input shaft speed.
[0008]
Therefore, the present invention has been made in view of the above problems, and it is possible to reliably provide an increase in the vehicle speed according to the driver's intention to accelerate even during re-acceleration such as kick-down acceleration as in start acceleration. Objective.
[0009]
[Means for Solving the Problems]
  The first invention is a driving state detecting means for detecting a driving state of a vehicle including a vehicle speed and an accelerator operation amount, a speed ratio determining means for determining a gear ratio according to the vehicle speed and the accelerator operation amount, and the determined And a control unit for controlling the transmission ratio of the continuously variable transmission based on the transmission gear ratio. A kickdown acceleration request determining unit for determining kickdown acceleration based on the accelerator operation amount. And an acceleration transmission characteristic determining means for determining a downshift transmission characteristic and an upshift transmission characteristic based on the accelerator operation amount and a vehicle speed, and a target determined by the transmission ratio determination means based on the downshift transmission characteristic. Downshift target value calculating means for calculating a downshift target speed ratio that is suppressed from the speed ratio, and an upshift target based on the upshift speed characteristics. Upshift target value calculating means for calculating a gear ratio, and after downshifting to the downshift target gear ratio of the downshift target value calculating means, upshifting according to the upshift target gear ratio of the upshift target value calculating means A virtual shift line generating means for calculating a virtual shift line to be output, and a kick that outputs a gear ratio according to the virtual shift line of the virtual shift line generating means instead of the speed ratio determining means when the kickdown acceleration is determined With control switching means during down accelerationThe acceleration shift characteristic determining means sets a plurality of shift lines in which a vehicle speed and a gear ratio or a target input shaft rotational speed are associated with each of the accelerator operation amounts for each of the downshift shift characteristic and the upshift shift characteristic, The downshift transmission characteristic is set so that the downshift amount decreases as the accelerator operation amount decreases, and the upshift transmission characteristic is set so that the upshift amount increases as the accelerator operation amount decreases.
[0012]
  The second2The invention of the above1In the invention, the acceleration shift characteristic determining means sets the downshift shift characteristic so that the downshift amount increases as the accelerator operation amount increases, and the upshift shift characteristic increases as the accelerator operation amount increases. Set the amount of upshift to be small.
[0013]
  The second3The invention of1st or 2ndDepartureClearlyThe acceleration shift characteristic determining means sets the downshift characteristic so that the downshift amount decreases as the vehicle speed increases.
[0014]
  The second4The first to the second inventions3In any one of the inventions, the kick-down acceleration request determination means detects an accelerator operation speed based on an accelerator operation amount, obtains a reference value corresponding to a preset vehicle speed and an accelerator operation amount, and When the operation speed exceeds the reference value, it is determined that the request is for kickdown acceleration.
[0015]
  The second5The invention of1st or 2ndDepartureClearlyThe downshift target value calculation means obtains a downshift target gear ratio by interpolation calculation according to the plurality of shift lines, the vehicle speed and the accelerator operation amount, and the upshift target value calculation means The upshift target gear ratio is obtained by interpolation according to the line, the vehicle speed, and the accelerator operation amount.
[0016]
【The invention's effect】
Therefore, the first invention is
When there is no kickdown acceleration request, the gear ratio determining means performs gearshift control at a gear ratio determined according to the vehicle speed and the accelerator operation amount. When there is a kickdown acceleration request, the downshift gear shift characteristic and the upshift gear shift characteristic are used. The upshift is performed after the downshift is performed by the virtual shift line calculated according to the driving state (accelerator operation amount and vehicle speed).
[0017]
As a result, after downshifting at the downshift target speed ratio with the suppressed downshift speed characteristics, the engine speed during acceleration is increased by upshifting to the speed ratio with the upshift target speed ratio according to the upshift speed characteristics. Suppressing an excessive increase in speed and a decrease in vehicle acceleration, balancing the rising and falling of the vehicle acceleration, can surely obtain the vehicle acceleration according to the driver's intention to accelerate, and is used in normal shift control Regardless of the speed change characteristics of the gear ratio determining means, the ideal speed change characteristics achieve acceleration response and acceleration extension during kickdown operation, maintaining a sense of acceleration according to the driver's acceleration intention, and further improving When shifting, it is possible to give an optimal change in the amount of upshifting to changes in the driver's accelerator operation, driving acceleration acceleration It from becoming possible to realize the intended manner.
[0018]
  Also, DaSince there are multiple shift lines that associate the vehicle speed, the gear ratio, or the target input shaft rotation speed for each accelerator operation amount for the downshift transmission characteristics and upshift transmission characteristics, the optimal transmission characteristics regardless of the accelerator operation amount or vehicle speed Thus, kickdown acceleration can be realized without being restricted by the speed change characteristics of the speed ratio determining means used in the normal speed change control.
[0019]
  AlsoASince the downshift amount is set to be small and the upshift amount is set to be large as the operation amount of the accelerator is small, it is possible to perform quiet kickdown acceleration with less noise by suppressing an increase in engine rotation speed.
[0020]
  The second2In the invention, the larger the accelerator operation amount is set, the more the downshift amount is set, and the upshift amount is set so as to be reduced. Therefore, the vehicle acceleration is quickly increased with a high driving force, and the engine speed is increased. And the vehicle speed can be increased together to continue the acceleration feeling according to the driver's intention to accelerate.
[0021]
  The second3In this invention, by setting the amount of downshift to be smaller as the vehicle speed is higher, it is possible to prevent an excessive increase in engine rotation speed and to suppress an increase in noise due to kickdown acceleration at high vehicle speeds. .
[0022]
  The second4According to the invention, the accelerator operation speed based on the accelerator operation amount is compared with a reference value corresponding to the preset vehicle speed and the accelerator operation amount, and when the accelerator operation speed exceeds the reference value, the kickdown acceleration is determined. The driver's acceleration intention can be accurately detected while preventing erroneous determination.
[0023]
  The second5According to the invention, even when there is no shift characteristic corresponding to the detected accelerator operation amount, it is possible to calculate an optimal shift characteristic by interpolation calculation and to generate a virtual shift line suitable for the driving state.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[0025]
FIG. 1 shows a schematic configuration of a vehicle to which the present invention is applied. An engine 11 is connected to a continuously variable transmission 10 provided with a torque converter 12 to an engine 11 so that an optimum driving state is obtained in accordance with a running state. The controller 1 which controls the output of 11 and the gear ratio of the continuously variable transmission 10 is provided. As the continuously variable transmission mechanism of the continuously variable transmission 10, a V-belt type or a toroidal type can be adopted.
[0026]
The controller 1 performs fuel injection amount control, ignition timing control, and the like of the engine 11 according to the operating state, and controls the speed ratio steplessly according to the operating state. The controller 1 is an integrated control device having both engine control means and shift control means.
[0027]
The controller 1 includes an accelerator sensor 5 that detects an accelerator pedal operation amount APO (or an accelerator operation amount), a vehicle speed sensor 4 that detects a traveling speed of the vehicle (hereinafter referred to as a vehicle speed VSP), and an engine rotation that detects a rotational speed Ne of the engine 11. The sensor 2 and the input shaft rotation sensor 3 for detecting the input shaft rotation speed Nt of the continuously variable transmission 10 are connected to detect the driving state of the vehicle. Here, the vehicle speed sensor 4 detects the output shaft rotational speed OutRev of the continuously variable transmission 10, and multiplies it by a constant (ratio of tire radius, etc.) according to the final reduction ratio and the vehicle specifications. And
[0028]
FIG. 2 is a block diagram showing the main configuration of the speed change control unit of the controller 1, in which the vehicle speed VSP from the vehicle speed sensor 4 and the accelerator operation amount APO from the accelerator sensor 5 are used to determine the driver's intention to reaccelerate. The operation determination unit 102, the mapless transmission unit 110, and the map transmission unit 120 are each input to the accelerator operation speed dAPO, which is a differential value of the accelerator operation amount APO, and is input to the kick-down operation determination unit 102.
[0029]
The kick-down operation determination unit 102 is a means for selecting whether the mapless transmission unit 110 or the map transmission unit 120 performs the shift control of the continuously variable transmission 10, and the accelerator operation speed dAPO is determined based on the vehicle speed VSP and the accelerator operation. If the predetermined value dAPOL determined by the amount APO is exceeded, it is determined that the driver has performed the kick-down operation, and the shift control by the mapless transmission unit 110 is selected. The shift control by the unit 120 is selected.
[0030]
First, the map transmission unit 120 searches for a target input shaft rotation speed (or target transmission ratio) according to the vehicle speed VSP and the accelerator operation amount APO based on the normal transmission map 121, and uses the target input shaft rotation speed as a command unit. Send to 130. The command unit 130 performs a speed change operation by driving the actuator of the continuously variable transmission 10 based on the input target input shaft speed.
[0031]
On the other hand, the mapless transmission unit 110 that controls the kickdown operation includes a downshift amount regulation map 111 in which a plurality of downshift amounts (downshift characteristics) corresponding to the vehicle speed VSP are set for each accelerator operation amount APO, and an accelerator. Upshift amount regulation map 112 in which a plurality of upshift amounts (upshift characteristics) corresponding to the vehicle speed VSP are set for each operation amount APO, and the downshift amount and upshift by interpolation calculation from the inputs to these two maps 111 and 112 The shift line interpolation calculation unit 113 that calculates the amount is mainly configured.
[0032]
In the interpolation calculation unit 113, since the downshift amount defining map 111 and the upshift amount defining map 112 are set for each accelerator operation amount APO, the downshift amount or the upshift amount corresponding to the input accelerator operation amount APO. If there is no value, a value is calculated by interpolation calculation from the preceding and following maps, and the downshift amount at the time of the kickdown operation is obtained from the downshift amount defining map 111, and after the downshift is completed, from the upshift amount defining map 112 The upshift amount from the time point of the kickdown operation is calculated, and the target input shaft rotational speed (or gear ratio) corresponding to the downshift amount or the upshift amount is output to the command unit 120. Then, the speed change characteristic at the time of the kick down operation becomes a locus indicated by the virtual speed change line 114. Note that the virtual shift line 114 at the time of the kick-down operation shows the output result of the interpolation calculation unit 113 as a locus corresponding to the elapsed time.
[0033]
Next, FIG. 3 is a flowchart showing an example of the shift control according to the present invention, which is periodically executed by the microcomputer of the controller 1 (for example, every several tens of milliseconds).
[0034]
In this control, the shift map 121 is displayed when a map shift mode in which the gear ratio is variably controlled so as to trace the shift map 121 of the map shift unit 120 and a predetermined acceleration condition (re-acceleration such as kickdown operation) is satisfied. The mapless speed change mode in which the speed is changed by the control of the mapless speed change unit 110 without tracing is switched.
[0035]
Although not explicitly shown in the figure, in the background of this flowchart, detection processing of the accelerator operation amount APO and the vehicle speed VSP is performed as the driving state. In the following description, numerals indicated by reference sign S correspond to the processing steps in FIG.
[0036]
First, in step S1, it is determined whether the previous control mode is the map shift mode or the mapless shift mode with reference to the control flag F, and if the previous control mode is the map shift mode, the step On the other hand, if the previous control mode is the mapless shift mode, the process proceeds to step S20 to determine whether or not the release condition for the mapless shift mode is satisfied. The control flag F indicates, for example, a mapless shift mode when it is 1, and a map shift mode when it is 0.
[0037]
In step S2, it is determined whether or not the driver's operation is a kick-down operation. First, the accelerator operation speed dAPO is obtained from the difference between the detected accelerator operation amount APO and the previous value of the accelerator operation amount APO.
[0038]
Then, based on the current vehicle speed VSP and the accelerator operation amount APO, a reference value dAPOL serving as a threshold value for the accelerator operation speed dAPO is obtained from the map shown in FIG. 4, and if the accelerator operation speed dAPO exceeds the reference value dAPOL, If it is determined that the operation is a kick-down operation, the process proceeds to step S4. If the accelerator operation is other than the kick-down operation, the process proceeds to step S30 to control the map shift mode.
[0039]
Note that the map of the accelerator operation speed reference value dAPOL corresponding to the accelerator operation amount APO and the vehicle speed VSP in FIG. 4 divides the accelerator operation amount APO into a plurality of ranges, and also partitions the vehicle speed VSP into a plurality of ranges. The reference value dAPOL is set for each range of the accelerator operation amount APO and the range of the vehicle speed VSP.
[0040]
Next, in step S4, which is determined to be a kick-down operation, the current vehicle speed VSP is set as the vehicle speed V0 at the time of the kick-down operation, and the control flag F = 1 is set, and then the process proceeds to step S6.
[0041]
In step S6, with reference to the mode flag Mf, it is determined whether or not the downshift mode is switched to the upshift mode in the mapless shift mode.
[0042]
When the mode flag Mf is 0, switching from the downshift mode to the upshift mode has not been completed, so it is determined that there is a mode transition, and when the mode flag Mf = 1, the mode is changed from the downshift mode. Since the transition to the upshift mode has been completed, it is determined that there is no mode transition. If there is a mode transition, the process proceeds to step S7, whereas if there is no mode transition, the process proceeds to step S10.
[0043]
In step S7, it is determined whether the downshift mode or the upshift mode.
[0044]
Here, the downshift speed ratio DW_ratio (0) is not set, or the actual speed ratio (input shaft rotational speed impRev / output shaft rotational speed OutRev) has reached the downshift speed ratio DW_ratio (0). If not, it is determined as the downshift mode and the process proceeds to step S8.
[0045]
On the other hand, if the actual speed ratio has reached the downshift speed ratio DW_ratio (0), it is determined that the mode is the upshift mode, and 1 is added to the mode flag Mf before the process proceeds to step S9.
[0046]
In step S8 of the downshift mode, the downshift amount is obtained from the vehicle speed VSP (V0) at the time of kickdown operation and the current accelerator operation amount APO from the downshift amount defining map 111 shown in FIG.
[0047]
Here, the downshift amount regulation map 111 in FIG. 5A shows the accelerator operation amount APO in angle, from 10 ° (1/8) fully closed to 80 ° (8/8) fully open. An example is shown in which eight shift lines (shift characteristics) are set every 10 °, and the downshift amount obtained from the accelerator operation amount APO and the vehicle speed VSP indicates the shift amount from the Hi-side gear ratio.
[0048]
In this map, if there is no shift line corresponding to the current accelerator operation amount APO, interpolation calculation is performed from the upper and lower shift lines to obtain the downshift speed ratio DW_ratio (0) corresponding to the vehicle speed V0 and the accelerator operation amount APO. Remember.
[0049]
Note that the number of shift lines set in the downshift amount regulation map 111 is appropriately set according to the disassembly capability of the accelerator sensor 5 and the capacity of the storage means (storage medium such as ROM) of the controller 1.
[0050]
Thereafter, the process proceeds to step S11, and the target speed ratio Dratio is calculated from the following equation.
[0051]
Dratio = DW_ratio (0) −UP_ratio (0) + UP_ratio (n) (1)
However, UP_ratio (0) is the initial value of the upshift amount, and UP_ratio (n) is the correction amount of the elapsed upshift amount (shift amount to the lower side of the gear ratio) according to the increase in the vehicle speed.
[0052]
Note that at the time of proceeding from step S8 to step S11, the upshift amount initial value UP_ratio (0) and the elapsed upshift amount UP_ratio (n) are both 0, and the target gear ratio Datio = DW_ratio (0).
[0053]
Next, in step S12, the target input shaft rotational speed DsrRev is set to
DsrRev = Dratio × OutRev (2)
The process proceeds to step S13 to output the target input shaft rotational speed DsrREv and control the speed ratio of the continuously variable transmission 10.
[0054]
On the other hand, in step S9, which is determined to be the upshift mode in the determination of step S7, the vehicle speed VSP (V0) at the time of the kickdown operation and the current accelerator operation are determined from the upshift amount regulation map 112 shown in FIG. The initial value UP_ratio (0) of the upshift amount is obtained from the amount APO and stored.
[0055]
Here, the upshift amount regulation map 112 in FIG. 5B shows the accelerator operation amount APO by an angle, and it is every 10 ° from 10 ° (1/8) to 80 ° (8/8) fully opened. 8 shows an example in which eight shift lines (shift characteristics) are set, and this upshift amount is the change amount of the shift ratio from the downshift gear ratio DW_ratio (0) to the upshift side (or the target input shaft rotational speed). DsrRev change amount).
[0056]
If there is no shift line corresponding to the current accelerator operation amount APO, interpolation calculation is performed from the upper and lower shift lines, and the downshift speed ratio DW_ratio (0) corresponding to the vehicle speed V0 and the accelerator operation amount APO is obtained and stored.
[0057]
Note that the number of shift lines set in the downshift amount regulation map 112 is appropriately set according to the disassembly capability of the accelerator sensor 5 and the capacity of the storage means (storage medium such as ROM) of the controller 1.
[0058]
Then, the process proceeds to step S11, the target gear ratio Dratio is calculated from the above equation (1), the target input shaft rotational speed DsrRev is obtained in step S12, and the target input shaft rotational speed is output in S13. However, at the time of proceeding from step S9 to step S11, the elapsed upshift amount UP_ratio (n) is 0 and the target gear ratio Datio = DW_ratio (0) −UP_ratio (0).
[0059]
Next, in step S10, in which it is determined in step S6 that there is no mode transition, the upshift according to the current accelerator operation amount APO and the current vehicle speed VSP from the upshift amount regulation map 112 of FIG. 5B. The shift amount is obtained as the elapsed upshift amount UP_ratio (n).
[0060]
Similarly to the upshift amount initial value UP_ratio (0), the elapsed upshift amount UP_ratio (n) is interpolated from the upper and lower shift lines when there is no shift line corresponding to the accelerator operation amount APO.
[0061]
In the next and subsequent times, this elapsed upshift amount UP_ratio (n) is updated, the process proceeds to step S11, the target speed ratio Datio is calculated from the above equation (1), and the target input shaft rotational speed is calculated from the above equation (2) in step S12. DsrRev is obtained, and the target input shaft rotational speed DsrRev is output in step S13.
[0062]
Next, in step S20 which proceeds when the previous control mode is the mapless shift mode in the determination of step S1, after the mapless shift mode is set, the accelerator operation amount APO is a predetermined value such as 0/8. If the predetermined time has elapsed since the return to the following and the mapless speed change mode has been entered, the mapless speed change mode is canceled and the process proceeds to step S20 to control the map speed change mode. When canceling the mapless speed change mode, the control flag F, the mode flag Mf, the downshift speed ratio DW_ratio (0), the upshift amount initial value UP_ratio (0), and the elapsed upshift amount UP_ratio (n) are respectively set. Reset to zero.
[0063]
In the map shift mode control in step S30, the target input shaft rotational speed DsrRev is obtained from the current vehicle speed VSP and the accelerator operation amount APO based on the shift map 121 in FIG. 2, and then output in step S13.
[0064]
On the other hand, if it is determined in step S20 that the accelerator operation amount APO is maintained at a predetermined value or more, it is determined that the driver intends to continue the kickdown acceleration, and the process proceeds to step S6, where the mapless speed change mode is set. Continue control.
[0065]
With the above control, in the map shift mode during normal travel, the shift is performed at the target input shaft rotational speed DsrRev according to the vehicle speed VSP and the accelerator operation amount APO based on the shift map 121 of FIG. When the driver performs a kick-down operation in which the accelerator operation speed dAPO exceeds the reference value dAPOL with the intention of kick-down acceleration, a down-shift amount defining map 111 that defines the shift characteristics of the down-shift and an up-shift On the basis of the upshift amount defining map 112 that defines the shift characteristics, kickdown acceleration is realized while calculating the shift characteristics according to the current driving state.
[0066]
When the accelerator is depressed and the accelerator operation speed dAPO exceeds the reference value dAPOL in FIG. 4 while traveling in the map shift mode, the mode shifts to the mapless shift mode. First, in the first control, the mode flag Mf = 0. Therefore, in step S8, the downshift speed ratio DW_ratio (0) is set.
[0067]
Here, the downshift speed ratio DW_ratio (0) is set to a downshift amount corresponding to the vehicle speed VSP for each accelerator operation amount APO as shown in the downshift amount regulation map 111 of FIG. Different shift characteristics are set according to the magnitude of the accelerator operation amount APO. Here, it is assumed that the amount of downshift from the highest Hi speed ratio (or target input shaft rotational speed DsrRev) of the normal speed change map 121 is shown.
[0068]
As shown in FIG. 6A, the downshift amount regulation map 111 is set so that the downshift amount becomes small when the accelerator operation amount APO is small (low opening in the figure). Is set so that the downshift amount increases when the vehicle speed is large (high opening in the figure), and further, the downshift amount is set to decrease as the vehicle speed VSP increases. Prevents excessive engine noise due to acceleration. In FIG. 6A, the representative maximum value (accelerator operation amount APO = 8/8 = 80 °) and minimum among the shift lines of the downshift amount regulation map 111 shown in FIG. Two values (accelerator operation amount APO = 1/8 = 10 °) are shown.
[0069]
Further, the downshift amount (target input shaft rotational speed change amount) of the downshift amount defining map 111 is lower in the change amount of the target input shaft rotational speed DsrRev than the downshift amount under the same conditions as the normal shift map 121. Suppressed and set to the small side (Hi side) of the gear ratio.
[0070]
For example, in FIG. 5A, when the accelerator operation amount APO is large (in the drawing, APO = 8/8 at a high opening), the downshift amount at the vehicle speed V0 (change in the gear ratio from the Hi-side gear ratio). (Amount) is (2) in the figure, and when converted to the input shaft rotational speed DsrRev according to the vehicle speed V0, point B in the figure corresponds to the downshift speed ratio DW_ratio (0) on the normal shift map 121 in FIG. Value.
[0071]
On the other hand, in the normal shift map 121, when the accelerator operation amount APO = 8/8 and the vehicle speed is V0, it is a point D in the figure where the shift line of APO = 8/8 is traced. The set downshift amount is set to a value that is suppressed to the Hi side (the smaller side of the gear ratio) as compared to the normal shift map 121.
[0072]
Next, the upshift amount after shifting to the downshift speed ratio DW_ratio (0) corresponds to the vehicle speed VSP for each accelerator operation amount APO as shown by the upshift amount regulation map 112 in FIG. An upshift amount is set, and different shift characteristics are set according to the magnitude of the accelerator operation amount APO.
[0073]
As shown in FIG. 6B, the upshift amount regulation map 112 is set so that the upshift amount increases with an increase in the vehicle speed VSP when the accelerator operation amount APO is small (low opening in the figure). Therefore, it is possible to perform quiet kickdown acceleration with less noise by suppressing an increase in engine rotation speed.
[0074]
Further, when the accelerator operation amount APO is large (high opening in the figure), the upshift amount with respect to the increase in the vehicle speed VSP is set to be small, and both the engine rotation speed and the vehicle speed are increased to meet the driver's intention to accelerate. Continue to feel acceleration.
[0075]
Further, the speed change characteristic is set such that the amount of upshift with respect to the increase in the vehicle speed VSP increases as the vehicle speed VSP decreases, so that the engine acceleration is prevented quickly and the vehicle acceleration is quickly increased.
[0076]
Next, an example of kickdown acceleration will be described with reference to FIGS.
[0077]
First, when the vehicle is traveling at point A on the shift map 121 in the map shift mode in FIG. 7, the kick-down operation is performed by stepping up to the high opening (accelerator operation amount APO = 8/8) in FIG. 6 (A). Then, the shift to the mapless speed change mode is made, and (2) in FIG. 6 (A) is set as the downshift amount, and the downshift amount (2) is added from the point A (highest Hi speed ratio) in FIG. The B point becomes the target input shaft rotational speed DsrRev (target speed ratio Dratio), and the downshift is started.
[0078]
When the actual gear ratio reaches point B, the upshift amount initial value UP_ratio (0) of the accelerator operation amount APO = 8/8 at the vehicle speed V0 at the time of the kickdown operation is determined from the upshift amount defining map 112 in FIG. Is set and the mode shifts to the upshift mode.
[0079]
In the upshift mode, the elapsed upshift amount UP_ratio (n) is updated for each control cycle in accordance with the increase in the vehicle speed VSP, and the elapsed upshift amount UP_ratio (n) at the vehicle speed V (n) in FIG. And upshift amount initial value UP_ratio (0),
Upshift amount = UP_ratio (0) −UP_ratio (n)
As a result, the shift amount of (4) in the figure is obtained as the upshift amount.
[0080]
Then, this upshift amount (4) is the same as the broken line (target gear ratio Datio) shifted to the Hi side by the upshift amount (4) from the downshift gear ratio DW_ratio (0) passing through point B in FIG. The point C corresponding to V (n) is set as a new target input shaft rotational speed DsrRev, and upshifting is performed.
[0081]
Thereafter, as the vehicle speed VSP increases, a new elapsed upshift amount UP_ratio (n) is set from the map of FIG. 6B, and the locus of the target input shaft rotational speed in the mapless shift mode is shown in FIG. It becomes like a virtual shift line 114a indicated by a thick solid line, and after downshifting, the predetermined engine speed upper limit value is reached while gradually shifting to the Hi side, and when the accelerator operation amount APO is large, the downshift amount is suppressed. However, since the amount of upshift is restricted to be small, as shown in FIG. 8, it is possible to prevent the engine speed from excessively increasing ((1) in the figure) and to quickly increase the vehicle acceleration. (<3> 'in the figure), and then the engine speed continues to increase without being constrained by the shift line of the shift map 121 due to the small upshift amount corresponding to the increase in the vehicle speed VSP. ((2) 'in the figure) prevents the acceleration from falling after the vehicle acceleration reaches its peak ((4)' in the figure), and maintains the acceleration feeling according to the driver's intention to accelerate. It becomes possible.
[0082]
The kickdown acceleration is similar to the kickdown operation when the accelerator operation amount APO is small. Similarly, when a kickdown acceleration with a low opening is performed from the point A in FIG. The downshift amount {circle around (1)} is obtained from the downshift amount regulation map 111. In FIG. 7, the point b at which the gear shifts from the point A to the Lo side by the downshift amount {circle around (1)} And a downshift is performed.
[0083]
When the actual gear ratio reaches the point b, the mode shifts to the upshift mode, and in FIG. 6B, the value obtained from the vehicle speed V0 at the time of the kickdown operation and the low opening shift line is the upshift amount initial value UP_ratio ( 0), and thereafter, the elapsed upshift amount UP_ratio (n) is updated every control cycle in accordance with the increase in the vehicle speed VSP, and the elapsed upshift amount UP_ratio at the vehicle speed V (n) in FIG. 6B. From (n) and the initial upshift amount UP_ratio (0),
Upshift amount = UP_ratio (0) −UP_ratio (n)
As a result, the shift amount of (3) in the figure is obtained as the upshift amount.
[0084]
The upshift amount {circle around (3)} is obtained by dividing the downshift speed ratio DW_ratio (0) passing through point b in FIG. 7 by the upshift amount {circle around (3)} to the Hi side (target speed ratio Datio) and the vehicle speed. The point c corresponding to V (n) is set as a new target input shaft rotational speed DsrRev, and an upshift is performed.
[0085]
Thus, in the kickdown acceleration with the low opening degree, the increase in the engine rotation speed is suppressed along the virtual shift line 114b in the drawing and the increase in noise is prevented without being restricted by the shift line of the shift map 121 in the map shift mode. In addition, the vehicle acceleration can be raised quietly and quickly, and a drop in the acceleration after the vehicle acceleration reaches the peak can be prevented to maintain the acceleration feeling according to the driver's acceleration intention.
[0086]
Further, in the upshift mode, when the accelerator operation amount APO fluctuates due to the fact that the driver has stepped on or loosened the accelerator, a plurality of shift lines are set for each accelerator operation amount APO as shown in FIG. Therefore, even if there is no shift line corresponding to the detected accelerator operation amount APO, it is possible to set an ideal elapsed upshift amount UP_ratio (n) corresponding to the change in the accelerator operation amount APO, and to accelerate the driver. It is possible to continue the kickdown acceleration while reflecting the intention faithfully.
[0087]
As described above, according to the present invention, at the time of kick-down operation, the downshift amount of the virtual shift line corresponding to the accelerator operation amount APO is controlled by the downshift amount defining map 111 while suppressing an excessive increase in engine speed. After the shift, the upshift amount of the virtual shift line corresponding to the vehicle speed VSP and the accelerator operation amount APO is updated every control cycle based on the upshift amount regulation map 112, so that the upshift is gradually performed. Realizes acceleration response and acceleration acceleration during kickdown operation to achieve a sense of acceleration according to the driver's intention to accelerate, with ideal shift characteristics without being limited by the shift lines of the conventional shift map 121 Furthermore, in the upshift mode, it is possible to give an optimal change in the amount of upshifting to changes in the driver's accelerator operation , It is possible to realize the elongation of the acceleration in the acceleration intention of the driver.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a continuously variable transmission according to an embodiment of the present invention.
FIG. 2 is a block diagram of a shift control unit of the controller.
FIG. 3 is a flowchart illustrating an example of shift control performed by a controller.
FIG. 4 is a map of a reference value dAPOL of an accelerator operation speed dAPO corresponding to an accelerator operation amount APO and a vehicle speed VSP.
FIG. 5 is a shift characteristic of a kickdown operation according to the accelerator operation amount APO and the vehicle speed VSP, (A) is a downshift amount regulation map for determining the downshift amount for each accelerator operation amount APO corresponding to the vehicle speed VSP; B) shows an upshift amount defining map for determining an upshift amount for each accelerator operation amount APO corresponding to the vehicle speed VSP.
FIG. 6 is an explanatory diagram of a shift characteristic of a kickdown operation according to an accelerator operation amount APO and a vehicle speed VSP, and FIG. A shift amount regulation map (B) is an upshift amount regulation map showing a part of the upshift amount for each accelerator operation amount APO corresponding to the vehicle speed VSP.
FIG. 7 is a comparative graph showing characteristics of a mapless shift mode on a shift map of the map shift mode.
FIG. 8 is a graph showing a relationship between an accelerator operation amount, an engine rotation speed, vehicle acceleration (front and rear G in the figure), and elapsed time.
9A and 9B show a conventional example, in which FIG. 9A is a shift map showing the state of start acceleration, and FIG. 9B is a shift map showing kickdown acceleration, showing the relationship between the vehicle speed and the target input shaft rotation speed according to the accelerator operation amount. Show.
[Explanation of symbols]
1 Controller
2 Engine rotation sensor
3 Input shaft rotation sensor
4 Vehicle speed sensor
5 Accelerator sensor
10 continuously variable transmission
11 Engine

Claims (5)

Driving state detection means for detecting the driving state of the vehicle including the vehicle speed and the amount of accelerator operation;
Gear ratio determining means for determining a gear ratio according to the vehicle speed and the accelerator operation amount;
A transmission control device for a continuously variable transmission, comprising control means for controlling the transmission ratio of the continuously variable transmission based on the determined transmission ratio;
Kickdown acceleration request determining means for determining kickdown acceleration based on the accelerator operation amount;
Acceleration shift characteristic determining means for determining the shift characteristic of the downshift and the shift characteristic of the upshift based on the accelerator operation amount and the vehicle speed,
Downshift target value calculating means for calculating a downshift target speed ratio that is suppressed from a target speed ratio determined by the speed ratio determining means based on the downshift speed characteristics;
Upshift target value calculation means for calculating an upshift target gear ratio based on the upshift transmission characteristics;
Virtual shift line generating means for calculating a virtual shift line for upshifting according to the upshift target speed ratio of the upshift target value calculating means after downshifting to the downshift target speed ratio of the downshift target value calculating means; ,
When the kickdown acceleration is determined, a kickdown acceleration control switching unit that outputs a gear ratio corresponding to the virtual transmission line of the virtual transmission line generation unit instead of the transmission ratio determination unit ,
The acceleration shift characteristic determining means sets a plurality of shift lines in which a vehicle speed and a gear ratio or a target input shaft rotation speed are associated with each of the accelerator operation amounts for the downshift shift characteristic and the upshift shift characteristic, The downshift transmission characteristic is set so that the downshift amount decreases as the accelerator operation amount decreases, and the upshift transmission characteristic is set so that the upshift amount increases as the accelerator operation amount decreases. A transmission control device for a continuously variable transmission.   The acceleration shift characteristic determining means includes:
  The downshift transmission characteristic is set so that the amount of downshift increases as the accelerator operation amount increases.
  2. The transmission control device for a continuously variable transmission according to claim 1, wherein the upshift transmission characteristic is set so that the upshift amount decreases as the accelerator operation amount increases.   The acceleration shift characteristic determining means includes:
  3. The transmission control device for a continuously variable transmission according to claim 1, wherein the downshift characteristics are set such that the amount of downshift decreases as the vehicle speed increases.   The kick down acceleration request determination means detects an accelerator operation speed based on an accelerator operation amount, obtains a reference value corresponding to a preset vehicle speed and an accelerator operation amount, and the accelerator operation speed exceeds a reference value The shift control device for a continuously variable transmission according to any one of claims 1 to 3, wherein it is determined that the request is for kick-down acceleration.   The downshift target value calculating means obtains a downshift target gear ratio by interpolation calculation according to the plurality of shift lines, the vehicle speed and the accelerator operation amount,
  3. The continuously variable transmission according to claim 1, wherein the upshift target value calculation means obtains an upshift target gear ratio by interpolation calculation according to the plurality of shift lines, a vehicle speed, and an accelerator operation amount. Shift control device.

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