JP2004183854A - Transmission controller for continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably increase the vehicle speed according to the intention of acceleration of a driver even in re-acceleration such as a kick-down acceleration imaginarily similar to the start acceleration. <P>SOLUTION: A controller 1 to installation the transmission ratio of a continuously variable transmission 10 based on the transmission ration determined according to vehicle speed VSP and accelerator pedal operation APO operates the target down-shift transmission ratio suppressed below the regular target transmission ratio based on the down-shift transmission characteristic of an acceleration-transmission characteristic determining means to respectively determine the down-shift transmission characteristic and the up-shift transmission characteristic based on the accelerator pedal operation APO and the vehicle speed VSP if the kick-down acceleration is requested based on the accelerator pedal operation APO, operates the target up-shift transmission ratio based on the up-shift transmission characteristic, and performs the transmission control along the imaginary transmission curve to be up-shifted according to the target up-shift transmission ratio of the target up-shift value operating means after down-shifting to the target down-shift ratio. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a shift control device for a vehicle having a continuously variable transmission.
[0002]
[Prior art]
In the shift control of a conventional continuously variable transmission, a shift pattern corresponding to a vehicle speed and an accelerator operation amount is stored as a map of a target input shaft speed, and a target speed ratio is determined from the target input shaft speed according to a driving state. (See JP-A-4-54371).
[0003]
In this conventional example, even if a kick-down operation for rapidly increasing the accelerator operation amount with the intention of rapid acceleration is performed from a steady running state in which the vehicle travels 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 rising immediately, and during that time, the engine seems to be blowing. It gives a strange feeling to the driver. That is, as shown in FIG. 9A, the shift map is set for each accelerator operation amount so as to obtain good acceleration at the time of starting, as shown in FIG. 9A. At the time of re-acceleration such as a kick-down operation, the downshift amount becomes excessively large, 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 against this, it is conceivable to suppress a change in the gear ratio when the acceleration demand is large. For example, a method has been proposed in which the gear ratio is fixed to a constant value when the throttle opening exceeds a threshold value (Japanese Patent No. 25933432). ). This means that the method of determining the constant speed ratio is the speed ratio on the speed change map when the throttle opening is a threshold value. As described above, by fixing the gear ratio before the gear ratio becomes large, an increase in engine rotation quickly increases the driving force, so that a time delay from the increase in the throttle to the feeling of acceleration is reduced. Accordingly, the uncomfortable feeling is reduced and the acceleration responsiveness on the bodily sensation is improved.
[0005]
[Patent Document 1]
JP-A-4-54371
[Patent Document 2]
Patent No. 2593432
[0006]
[Problems to be solved by the invention]
However, in the latter conventional example (Japanese Patent No. 2593432), the constant gear ratio is maintained as long as the throttle opening is not returned from the threshold and the hysteresis setting, thereby satisfying the driver's initial acceleration intention. Since the change of the gear ratio does not occur after that, it causes a sense of incongruity. In other words, in order to generate a change in the gear ratio, an operation of intentionally returning the accelerator pedal to a large value is required, and there has been a problem that drivability is reduced.
[0007]
As a countermeasure, it is conceivable to control the trajectory of the target input shaft rotation speed by a time constant.However, during re-acceleration such as kick-down acceleration, the amount of additional point at the beginning of gear shifting differs for each operating condition. There is a problem that it is practically difficult to define the amount of increase in the target input shaft rotation speed at the time, and it is extremely difficult to cope with an increase in vehicle speed and an increase in the input shaft rotation speed because it is a function of time.
[0008]
Accordingly, the present invention has been made in view of the above-described problems, and it is an object of the present invention to reliably provide a vehicle speed increase according to the driver's acceleration intention at the time of re-acceleration such as kick down acceleration as well as at the time of start acceleration. Aim.
[0009]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a driving state detecting unit that detects a driving state of a vehicle including a vehicle speed and an accelerator operation amount, a gear ratio determining unit that determines a gear ratio according to the vehicle speed and an accelerator operation amount, Control means for controlling the speed ratio of the continuously variable transmission based on the speed ratio.
Kick-down acceleration request determining means for determining kick-down acceleration based on the accelerator operation amount; and acceleration shift characteristic determination for determining a down-shift speed characteristic and an up-shift speed characteristic based on the accelerator operation amount and the vehicle speed, respectively. Means, a downshift target value calculating means for calculating a downshift target gear ratio suppressed from a target gear ratio determined by the gear ratio determining means based on the downshift gear characteristics, and a downshift target value calculating means based on the upshift gear characteristics. Upshift target value calculating means for calculating an upshift target gear ratio, and after downshifting to the downshift target gear ratio of the downshift target value calculating means, according to the upshift target gear ratio of the upshift target value calculating means. Virtual shift line generating means for calculating a virtual shift line to be upshifted, and the kick down When the speed is determined, and a kickdown acceleration control switching means for outputting a gear ratio corresponding to the imaginary shift line of a virtual shift line generation means on behalf of the gear ratio determining means.
[0010]
In a second aspect based on the first aspect, the speed change characteristic for acceleration is determined by associating the downshift speed characteristic with a vehicle speed and a speed ratio or a target input shaft rotation speed for each accelerator operation amount. A plurality of shift lines are set, and a plurality of shift lines in which the vehicle speed and the speed ratio or the target input shaft rotation speed are associated with each other for the accelerator operation amount are set in the upshift speed change characteristics.
[0011]
In a third aspect based on the second aspect, the acceleration shift characteristic determining means sets the downshift shift characteristic such that the smaller the accelerator operation amount, the smaller the downshift amount. The shift shift characteristic is set so that the upshift amount increases as the accelerator operation amount decreases.
[0012]
In a fourth aspect based on the second aspect, the acceleration shift characteristic determining means sets the downshift shift characteristic such that the downshift amount increases as the accelerator operation amount increases, and the upshift amount changes. The shift characteristic is set so that the upshift amount decreases as the accelerator operation amount increases.
[0013]
In a fifth aspect based on any one of the first to fourth aspects, the speed change characteristic for acceleration is determined such that the downshift speed change characteristic decreases as the vehicle speed increases. Set to.
[0014]
In a sixth aspect based on any one of the first to fifth aspects, the kick-down acceleration request determination means detects an accelerator operation speed based on an accelerator operation amount and sets a predetermined vehicle speed. And a reference value according to the accelerator operation amount, and when the accelerator operation speed exceeds the reference value, it is determined that the request is for a kickdown acceleration.
[0015]
In a seventh aspect based on any one of the second to fourth aspects, the downshift target value calculation means performs a downshift by interpolation calculation according to the plurality of shift lines, vehicle speed, and accelerator operation amount. A shift target gear ratio is obtained, and the upshift target value calculating means obtains an upshift target gear ratio by interpolation calculation according to the plurality of shift lines, vehicle speed, and accelerator operation amount.
[0016]
【The invention's effect】
Therefore, the first invention is:
When there is no request for kickdown acceleration, the gear ratio control means performs gearshift control at a speed ratio determined according to the vehicle speed and the accelerator operation amount. An upshift is performed after a 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 performing a downshift at the downshift target gear ratio of the suppressed downshift gear characteristic, and performing an upshift to the gear ratio at the upshift target gear ratio by the upshift gear characteristic, the engine speed during acceleration is reduced. Excessive increase in speed and decrease in vehicle acceleration are suppressed, and the rise and fall of vehicle acceleration are balanced to ensure that vehicle acceleration according to the driver's acceleration intention is obtained. Rather than being constrained by the shifting characteristics of the gear ratio determining means, the ideal shifting characteristics enable the acceleration response and the acceleration of the kick-down operation to be maintained, maintaining the feeling of acceleration according to the driver's acceleration intention and further improving During a shift, an optimal change in the upshift amount can be given to a change in the driver's accelerator operation. It from becoming possible to realize the intended manner.
[0018]
According to the second aspect of the present invention, the downshift characteristics and the upshift characteristics are set to a plurality of shift lines each corresponding to the vehicle speed and the gear ratio or the target input shaft rotation speed for each accelerator operation amount. It is possible to obtain the optimal shift characteristics regardless of the vehicle speed and the vehicle speed, and realize the kickdown acceleration without being restricted by the shift characteristics of the speed ratio determining means used in the normal shift control.
[0019]
According to the third aspect of the present invention, the downshift amount is set to be smaller and the upshift amount is set to be larger as the accelerator operation amount is smaller. It can be carried out.
[0020]
According to the fourth aspect of the present invention, the downshift amount is set to be larger as the accelerator operation amount is larger, and the upshift amount is set to be smaller, so that the vehicle acceleration can be quickly started with a high driving force. By increasing both the engine rotation speed and the vehicle speed, it is possible to continue the feeling of acceleration according to the driver's acceleration intention.
[0021]
According to the fifth aspect of the present invention, by setting the downshift amount to be smaller as the vehicle speed is higher, an increase in the engine rotation speed is prevented from being excessively increased, and noise is increased by kickdown acceleration at a high vehicle speed. To suppress.
[0022]
According to a sixth aspect of the present invention, the accelerator operation speed based on the accelerator operation amount is compared with a reference value corresponding to a preset vehicle speed and an accelerator operation amount, and the kick-down acceleration is performed when the accelerator operation speed exceeds the reference value. Is determined, erroneous determination can be prevented, and the driver's intention to accelerate can be accurately detected.
[0023]
Further, according to the seventh aspect, 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 and generate a virtual shift line suitable for the driving state.
[0024]
BEST MODE FOR CARRYING OUT 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, in which an engine 11 is connected to a continuously variable transmission 10 having a torque converter 12 so that an optimal driving state is obtained according to a driving state. The controller 1 controls the output of the transmission 11 and the gear ratio of the continuously variable transmission 10. The continuously variable transmission mechanism of the continuously variable transmission 10 may be a V-belt type or a toroidal type.
[0026]
The controller 1 performs fuel injection amount control, ignition timing control, and the like of the engine 11 according to the operation state, and controls the speed ratio steplessly according to the operation 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 for detecting an accelerator pedal operation amount APO (or an accelerator operation amount), a vehicle speed sensor 4 for detecting a running speed of a vehicle (hereinafter, a vehicle speed VSP), and an engine rotation for detecting a rotation speed Ne of the engine 11. A sensor 2, an input shaft rotation sensor 3 for detecting an input shaft rotation speed Nt of the continuously variable transmission 10 and the like are connected, and detect as a driving state of the vehicle. Here, the vehicle speed sensor 4 detects the output shaft rotation speed OutRev of the continuously variable transmission 10 and multiplies it by a final reduction ratio or a constant (such as a tire radius) according to the vehicle specification to obtain a vehicle speed VSP. And
[0028]
FIG. 2 is a block diagram showing a main configuration of a shift control unit of the controller 1. The vehicle speed VSP from the vehicle speed sensor 4 and the accelerator operation amount APO from the accelerator sensor 5 are kicked down to determine the driver's intention to re-accelerate. The accelerator operation speed dAPO, which is input to the operation determination unit 102, the mapless transmission unit 110, and the map transmission unit 120, and is a differential value of the accelerator operation amount APO, is input to the kick down operation determination unit 102.
[0029]
The kick-down operation determination unit 102 is a unit that selects whether the shift control of the continuously variable transmission 10 is controlled by the mapless transmission unit 110 or the map transmission unit 120. The accelerator operation speed dAPO is determined by the vehicle speed VSP and the accelerator operation. If it exceeds a predetermined value dAPOL determined by the amount APO, it is determined that the driver has performed a 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 retrieves 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 this target input shaft rotation speed as a command unit. Send to 130. The command unit 130 drives the actuator or the like of the continuously variable transmission 10 based on the input target input shaft rotation speed to perform a shift operation.
[0031]
On the other hand, the mapless transmission unit 110 that performs control at the time of the kick-down operation includes a downshift amount defining 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; An upshift amount defining 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 a downshift amount and an upshift by interpolation calculation from inputs to these two maps 111 and 112. The shift line interpolation calculation unit 113 that calculates the amount is mainly configured.
[0032]
Since the interpolation calculation unit 113 sets the downshift amount defining map 111 and the upshift amount defining map 112 for each accelerator operation amount APO, the downshift amount or the upshift amount corresponding to the input accelerator operation amount APO is set. If there is no, a value is calculated by interpolation from the preceding and following maps, 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, the value is calculated from the upshift amount defining map 112. An upshift amount from the time of the kickdown operation is calculated, and a target input shaft rotation speed (or gear ratio) corresponding to the downshift amount or the upshift amount is output to the command unit 120. Then, the shift characteristic at the time of the kick down operation is a locus indicated by the virtual shift line 114. The virtual shift line 114 at the time of the kick down operation indicates the output result of the interpolation calculation unit 113 as a trajectory according 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 executed periodically (for example, every several tens of msec) by the microcomputer of the controller 1.
[0034]
In this control, the map shift mode in which the shift ratio is variably controlled so as to trace the shift map 121 of the map shift unit 120 and the shift map 121 when a predetermined acceleration condition (re-acceleration such as a kick-down operation) is satisfied. The mode is switched to a mapless shift mode in which the shift is performed under the control of the mapless shift unit 110 without tracing.
[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 addition, in the following description, the numbers indicated by reference symbols 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. If the previous control mode is the map shift mode, the process proceeds to step S1. While the process proceeds to the kick down operation determination in S2, if the previous control mode is the mapless shift mode, the process proceeds to step S20 to determine whether or not the release condition of the mapless shift mode is satisfied. The control flag F indicates, for example, 1 when the mapless shift mode is set, and 0 when the control flag F indicates the map shift mode.
[0037]
In step S2, it is determined whether the driver's operation is a kick down operation. First, an accelerator operation speed dAPO is obtained from a 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 which is a threshold value of the accelerator operation speed dAPO is obtained from the map shown in FIG. 4. If the accelerator operation speed dAPO exceeds the reference value dAPOL, It is determined that the operation is a kick down operation, and 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 amount APO and the reference value dAPOL of the accelerator operation speed according to the vehicle speed VSP in FIG. 4 divides the accelerator operation amount APO into a plurality of ranges, and divides the vehicle speed VSP into a plurality of ranges. The reference value dAPOL is set for each of the range of the accelerator operation amount APO and the range of the vehicle speed VSP.
[0040]
Next, in step S4 in which it is determined that the kick-down operation is performed, 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 is set to 1, and then the process proceeds to step S6.
[0041]
In step S6, it is determined with reference to the mode flag Mf whether or not to switch from the downshift mode to the upshift mode in the mapless shift mode.
[0042]
When the mode flag Mf is 0, it is determined that there is a mode shift because the switching from the downshift mode to the upshift mode has not been completed, and when the mode flag Mf = 1, the mode is switched from the downshift mode to the upshift mode. Since the shift to the upshift mode has been completed, it is determined that there is no mode shift. If there is a mode transition, the process proceeds to step S7, and if there is no mode transition, the process proceeds to step S10.
[0043]
In step S7, it is determined whether the mode is 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 rotation speed impRev / output shaft rotation speed OutRev) has reached the downshift speed ratio DW_ratio (0). If not, it is determined that the mode is the downshift mode, and the process proceeds to step S8.
[0045]
On the other hand, if the actual gear ratio has reached the downshift gear ratio DW_ratio (0), it is determined that the upshift mode has been set, and 1 is added to the mode flag Mf before proceeding to step S9.
[0046]
In step S8 in the downshift mode, the downshift amount is obtained from the vehicle speed VSP (V0) at the time of the kickdown operation and the current accelerator operation amount APO from the downshift amount defining map 111 shown in FIG.
[0047]
Here, the downshift amount defining map 111 of FIG. 5A shows the accelerator operation amount APO by an angle, from 10 degrees (1/8) of fully closed to 80 degrees (8/8) of fully opened. An example is shown in which eight shift lines (shift characteristics) are set at intervals of 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, an interpolation operation is performed from the upper and lower shift lines to obtain the vehicle speed V0 and the downshift speed ratio DW_ratio (0) corresponding to the accelerator operation amount APO. To remember.
[0049]
The number of shift lines set in the downshift amount defining map 111 is appropriately set according to the resolution of the accelerator sensor 5 and the capacity of storage means (a storage medium such as a 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]
Ratio = DW_ratio (0) −UP_ratio (0) + UP_ratio (n) (1)
Here, UP_ratio (0) is the initial value of the upshift amount, and UP_ratio (n) is the correction amount of the elapsed upshift amount (the shift amount to a smaller gear ratio) according to the increase in the vehicle speed.
[0052]
When the process proceeds 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 Dratio = DW_ratio (0).
[0053]
Next, in step S12, the target input shaft rotation speed DsrRev is
DsrRev = Dratio × OutRev (2)
The process proceeds to step S13 to output the target input shaft rotation speed DsrREv, and controls the speed ratio of the continuously variable transmission 10.
[0054]
On the other hand, in step S9 in which the upshift mode is determined in the determination in step S7, the vehicle speed VSP (V0) at the time of the kick down operation and the current accelerator operation are obtained from the upshift amount defining map 112 shown in FIG. An upshift amount initial value UP_ratio (0) is obtained from the amount APO and stored.
[0055]
Here, the upshift amount defining map 112 of FIG. 5B shows the accelerator operation amount APO by an angle, and every 10 ° from 10 ° (1/8) to 80 ° (8/8) of full opening. The figure shows an example in which eight shift lines (shift characteristics) are set, and the upshift amount is a shift ratio change amount (or target input shaft rotation speed) from the downshift speed ratio DW_ratio (0) to the upshift side. DsrRev change amount).
[0056]
If there is no shift line corresponding to the current accelerator operation amount APO, an interpolation calculation is performed from the upper and lower shift lines to obtain and store the vehicle speed V0 and the downshift speed ratio DW_ratio (0) corresponding to the accelerator operation amount APO.
[0057]
Note that the number of shift lines set in the downshift amount defining map 112 is appropriately set according to the resolution of the accelerator sensor 5 and the capacity of the storage means (a storage medium such as a ROM) of the controller 1.
[0058]
Then, the process proceeds to step S11, where the target gear ratio Dratio is calculated from the above equation (1), the target input shaft rotation speed DsrRev is obtained in step S12, and the target input shaft rotation speed is output in S13. However, when the process proceeds from step S9 to step S11, the elapsed upshift amount UP_ratio (n) is 0, and the target speed ratio Dratio = DW_ratio (0) -UP_ratio (0).
[0059]
Next, in step S10, in which it is determined in step S6 that there is no mode shift, in step S10, an up-shift according to the current accelerator operation amount APO and the current vehicle speed VSP is obtained from the up-shift amount defining map 112 in FIG. The shift amount is obtained as a lapsed upshift amount UP_ratio (n).
[0060]
Similarly to the upshift amount initial value UP_ratio (0), when the shift line corresponding to the accelerator operation amount APO does not exist, the elapsed upshift amount UP_ratio (n) performs the interpolation calculation from the upper and lower shift lines.
[0061]
From the next time on, the elapsed upshift amount UP_ratio (n) is updated, and the process proceeds to step S11, where the target speed ratio Dratio is calculated from the above equation (1), and in step S12, the target input shaft rotational speed is calculated using the above equation (2). DsrRev is obtained, and a target input shaft rotation 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 in step S1, the accelerator operation amount APO is set to a predetermined value such as 0/8 after the mapless shift mode is set. If the process returns to the following, and if a predetermined time has elapsed since the shift to the mapless shift mode, the mapless shift mode is canceled, and the process proceeds to step S20 to control the map shift mode. When the mapless shift mode is canceled, 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 rotation 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 equal to or greater than the predetermined value, the driver determines that the driver intends to continue kickdown acceleration, and proceeds to step S6 to execute the mapless shift mode. Control is continued.
[0065]
According to the above control, in the map shift mode during normal running, shifting is performed at the target input shaft rotation speed DsrRev based on the vehicle speed VSP and the accelerator operation amount APO based on the shift map 121 in 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 down-shift speed characteristics, and an up-shift Kick-down acceleration is realized while calculating the shift characteristics according to the current driving state based on the upshift amount defining map 112 that defines the shift characteristics of the vehicle.
[0066]
If the accelerator operation speed dAPO exceeds the reference value dAPOL shown in FIG. 4 while the accelerator pedal is depressed during 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, as shown in the downshift amount defining map 111 in FIG. 5A, the downshift speed ratio DW_ratio (0) is set to the downshift amount corresponding to the vehicle speed VSP for each accelerator operation amount APO, and Different shift characteristics are set according to the magnitude of the accelerator operation amount APO. Here, the downshift amount from the maximum Hi speed ratio (or the target input shaft rotation speed DsrRev) of the normal shift map 121 is shown.
[0068]
As shown in FIG. 6A, the downshift amount defining map 111 is set so that when the accelerator operation amount APO is small (low opening in the figure), the downshift amount is small, and the accelerator operation amount APO Is large (high opening in the figure), the downshift amount is set to increase, and the downshift amount is set to decrease as the vehicle speed VSP increases, and kickdown at high vehicle speed is performed. Prevent engine noise from becoming excessive due to acceleration. In FIG. 6A, a representative maximum value (accelerator operation amount APO = 8/8 = 80 °) and a minimum value in the shift lines of the downshift amount defining map 111 shown in FIG. Two values (accelerator operation amount APO = 1/8 = 10 °) are shown.
[0069]
The downshift amount (target input shaft rotation speed change amount) of the downshift amount definition map 111 is smaller than the change amount of the target input shaft rotation speed DsrRev as compared with the downshift amount under the same conditions as the normal shift map 121. The speed ratio is set to a small side (Hi side).
[0070]
For example, in FIG. 5A, the downshift amount (change in gear ratio from the Hi-side gear ratio) at the vehicle speed V0 on the shift line when the accelerator operation amount APO is large (APO = 8/8 at high opening in the figure). The amount is (2) in the figure, and when converted into the input shaft rotation speed DsrRev corresponding to the vehicle speed V0, the 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 is 8/8 and the vehicle speed is V0, this is point D in the figure where the shift line of APO = 8/8 is traced. The set downshift amount is set to be a value suppressed to the Hi side (smaller gear ratio side) than the normal shift map 121.
[0072]
Next, the upshift amount after shifting to the downshift speed ratio DW_ratio (0) depends on the vehicle speed VSP for each accelerator operation amount APO as shown in the upshift amount defining map 112 in FIG. The 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, when the accelerator operation amount APO is small (low opening in the figure), the upshift amount defining map 112 is set so that the upshift amount increases with an increase in the vehicle speed VSP. Thus, it is possible to suppress a rise in the engine rotation speed and perform quiet kickdown acceleration with less noise.
[0074]
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 small, and both the engine rotation speed and the vehicle speed are increased to meet the driver's acceleration intention. Continue to accelerate.
[0075]
Further, the shift characteristic is set such that the upshift amount with respect to the increase in the vehicle speed VSP increases as the vehicle speed VSP decreases, and the vehicle acceleration is quickly increased by preventing the engine from running idle.
[0076]
Next, an example of kickdown acceleration will be described with reference to FIGS.
[0077]
First, when the vehicle is traveling at the point A of the shift map 121 in the map shift mode in the map shift mode in FIG. 7, the kick-down operation is performed by further stepping up to the high opening degree (accelerator operation amount APO = 8/8) in FIG. Then, the mode shifts to the mapless shift mode, (2) in FIG. 6A is set as the downshift amount, and only the downshift amount (2) is added from the point A (the highest Hi speed ratio) in FIG. At point B becomes the target input shaft rotation speed DsrRev (target speed ratio Dratio), and the downshift is started.
[0078]
When the actual gear ratio reaches the 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 obtained from the upshift amount defining map 112 of 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 every 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 the upshift amount initial value UP_ratio (0),
Upshift amount = UP_ratio (0) −UP_ratio (n)
As a result, the shift amount (4) in the figure is obtained as the upshift amount.
[0080]
The upshift amount {circle around (4)} corresponds to the dashed line (target speed ratio Ratio) obtained by shifting the downshift speed 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 rotation speed DsrRev, and an upshift is performed.
[0081]
Thereafter, according to the increase of the vehicle speed VSP, a new elapsed upshift amount UP_ratio (n) is set from the map of FIG. 6B, and the locus of the target input shaft rotation speed in the mapless shift mode is shown in FIG. The virtual shift line 114a shown by a bold solid line is obtained. After the downshift, the engine shift speed is gradually shifted to the Hi side and reaches a predetermined engine rotational speed upper limit. When the accelerator operation amount APO is large, the downshift amount is suppressed. However, as shown in FIG. 8, it is possible to prevent the engine rotational speed from excessively increasing ((1) 'in the figure) and quickly increase the vehicle acceleration as shown in FIG. (3 ′ ′ in the figure), and thereafter, the engine speed is increased without being bound by the shift line of the shift map 121 by a small upshift amount corresponding to the increase of the vehicle speed VSP. Since it can be continued ((2) 'in the figure), it is necessary to prevent a drop in the acceleration after the vehicle acceleration reaches the peak ((4)' in the figure) and maintain the feeling of acceleration according to the driver's intention to accelerate. It becomes possible.
[0082]
This kick-down acceleration is the same as the kick-down operation when the accelerator operation amount APO is small. Similarly, when the kick-down acceleration with a low opening is performed from the point A in FIG. 7, first, FIG. The downshift amount (1) is obtained from the downshift amount defining map 111. In FIG. 7, the point b at which the gear is shifted from the point A to the Lo side by the downshift amount (1) is the target input shaft rotation speed DsrRev (target speed ratio Dratio). And a downshift is performed.
[0083]
When the actual speed ratio reaches 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 kick-down operation and the shift line with a low opening 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. (N) and the upshift amount initial value UP_ratio (0),
Upshift amount = UP_ratio (0) −UP_ratio (n)
As a result, the shift amount (3) in the figure is obtained as the upshift amount.
[0084]
The upshift amount {circle around (3)} corresponds to the dashed line (target gear ratio Ratio) obtained by shifting the downshift speed 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 rotation speed DsrRev, and an upshift is performed.
[0085]
Thus, in the kick-down acceleration with a low opening, the increase in the engine rotational speed is suppressed along the virtual shift line 114b in the figure without being restricted by the shift line of the shift map 121 in the map shift mode, thereby preventing an increase in noise. In addition, the vehicle acceleration can be started quietly and quickly, and the acceleration after the vehicle acceleration reaches the peak can be prevented from dropping, so that the acceleration feeling according to the driver's acceleration intention can be maintained.
[0086]
Further, in the upshift mode, when the accelerator operation amount APO fluctuates due to the driver stepping on or loosening 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 a change in the accelerator operation amount APO, and to accelerate the driver. It is possible to continue kickdown acceleration by faithfully reflecting the intention.
[0087]
As described above, according to the present invention, at the time of the kick down operation, the down shift amount is defined by the down shift amount defining map 111 while suppressing the excessive increase in the engine rotational speed by the down shift amount of the virtual shift line corresponding to the accelerator operation amount APO. After the shift is performed, 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 defining map 112, so that the upshift is performed gradually. With the ideal shift characteristic without being restricted by the shift line of the conventional shift map 121, the acceleration response and the acceleration increase at the time of the kick down operation are realized, and the acceleration feeling according to the driver's acceleration intention is realized. In the upshift mode, it is possible to give the optimal change in the upshift amount to the change 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 according to an accelerator operation amount APO and a vehicle speed VSP.
FIG. 5 is a shift characteristic of a kick down operation according to an accelerator operation amount APO and a vehicle speed VSP. FIG. 5A is a downshift amount defining map for determining a downshift amount for each accelerator operation amount APO corresponding to a 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 kick down operation according to an accelerator operation amount APO and a vehicle speed VSP. FIG. 6A is a down view showing a part of a downshift amount for each accelerator operation amount APO corresponding to a vehicle speed VSP. The shift amount defining map (B) is an upshift amount defining map showing a part of the upshift amount for each accelerator operation amount APO corresponding to the vehicle speed VSP.
FIG. 7 is a comparison graph showing characteristics of a mapless shift mode on a shift map in a map shift mode.
FIG. 8 is a graph showing a relationship between an accelerator operation amount, an engine rotation speed, a vehicle acceleration (front and rear G in the figure) and an elapsed time.
9A and 9B show a conventional example, wherein FIG. 9A is a shift map showing a state of start acceleration, and FIG. 9B is a shift map showing kickdown acceleration, showing a relationship between a vehicle speed and a target input shaft rotation speed according to an 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 (7)

Driving state detecting means for detecting a driving state of the vehicle including a vehicle speed and an accelerator operation amount;
Speed ratio determining means for determining a speed ratio according to the vehicle speed and the accelerator operation amount,
Control means for controlling the speed ratio of the continuously variable transmission based on the determined speed ratio.
Kickdown acceleration request determination means for determining kickdown acceleration based on the accelerator operation amount,
An acceleration shift characteristic determining unit that determines a shift characteristic of a downshift and a shift characteristic of an upshift based on the accelerator operation amount and the vehicle speed, respectively.
Downshift target value calculating means for calculating a downshift target gear ratio suppressed from a target gear ratio determined by the gear ratio determining means based on the downshift gear characteristics;
Upshift target value calculating means for calculating an upshift target gear ratio based on the upshift gear characteristic,
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; ,
Kick down acceleration control switching means for outputting a gear ratio according to a virtual shift line of a virtual shift line generating means in place of the gear ratio determining means when the kick down acceleration is determined. Transmission control device for a continuously variable transmission. The acceleration shift characteristic determining means includes:
A plurality of shift lines in which the vehicle speed and the gear ratio or the target input shaft rotation speed are associated with each other for each accelerator operation amount are set in the downshift shift characteristic,
2. The shift control of the continuously variable transmission according to claim 1, wherein 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 other for each accelerator operation amount are set in the upshift shift characteristic. apparatus. The acceleration shift characteristic determining means,
The downshift speed change characteristic is set so that the downshift amount decreases as the accelerator operation amount decreases,
The shift control device for a continuously variable transmission according to claim 2, wherein the upshift speed change characteristic is set such that the upshift amount increases as the accelerator operation amount decreases. The acceleration shift characteristic determining means,
The downshift speed change characteristic is set so that the downshift amount increases as the accelerator operation amount increases,
The shift control device for a continuously variable transmission according to claim 2, wherein the upshift speed change characteristic is set so that the upshift amount decreases as the accelerator operation amount increases. The acceleration shift characteristic determining means,
5. The shift control device for a continuously variable transmission according to claim 1, wherein the downshift speed change characteristic is set such that the downshift amount decreases as the vehicle speed increases. The kickdown acceleration request determination means detects an accelerator operation speed based on an accelerator operation amount, obtains a reference value according to a preset vehicle speed and an accelerator operation amount, and when 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 5, wherein it is determined that the request is for kickdown acceleration. The 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,
5. The upshift target gear ratio according to claim 2, wherein the upshift target value calculating means obtains an upshift target gear ratio by interpolation based on the plurality of shift lines, the vehicle speed, and the accelerator operation amount. 3. The shift control device for a continuously variable transmission according to claim 1.

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