JP2014098464A - Speed change control device of continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed change control device of a continuously variable transmission that can reduce the uncomfortable feeling of a driver to the execution timing of step-down.SOLUTION: In this speed change control device, an accelerator opening Asft for speed change control is set by using an actual accelerator opening A, and the continuously variable transmission is controlled on the basis of the accelerator opening Asft for speed change control. Then, the accelerator opening Asft for speed change control is maintained until the actual accelerator opening A reaches a down-line (speed change threshold) D, and every time the actual accelerator opening A is raised and reaches the down-line D, the accelerator opening Asft for the speed control is updated to a high-opening side stepwise, and the down-line D is raised to a prescribe amount ΔDa. Then, a vehicle speed change amount ΔV from the time of the updating to a present time t is acquired, and the down-line D is further raised as the vehicle speed change amount ΔV is large (that is, the acceleration intention of the driver is small).

Description

  The present invention relates to a transmission control device that controls a continuously variable transmission that can continuously change the rotational speed of an engine.

  In Patent Document 1, the accelerator opening for shift control is set according to the actual accelerator opening, a dead zone (hysteresis) is provided between the actual accelerator opening and the accelerator opening for shift control, and the actual accelerator opening is Disclosed is a technology that fixes the accelerator opening for shift control until it increases by the hysteresis, and linearly increases the accelerator opening for shift control according to the actual accelerator opening after the actual accelerator opening increases by the hysteresis. Has been.

JP 2010-112397 A

  However, in Patent Document 1, after the actual accelerator opening increases by the amount of hysteresis, the shift control accelerator opening increases linearly according to the actual accelerator opening, so that a direct acceleration feeling when the accelerator is depressed is given to the driver. There is a problem that can not be given to.

  In order to solve this problem, every time the actual accelerator opening increases by the hysteresis, the shift control accelerator opening is updated to the same value (that is, stepped) as the actual accelerator opening (that is, the downshift is stepped). Technology (proposed technology) that gives the driver a direct acceleration feeling when the accelerator is depressed has been proposed.

  However, in this proposed technique, since the hysteresis is fixed, the step-down (ie, step-like downshift) can be performed at the same timing regardless of the driver's accelerator operation (for example, the accelerator is depressed quickly or slowly). Done. For this reason, there is a problem that the driver feels uncomfortable with respect to the step-down execution timing.

  Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a transmission control device for a continuously variable transmission that can reduce a driver's uncomfortable feeling with respect to a step-down execution timing.

  In order to solve the above problems, a transmission control device for a continuously variable transmission according to the present invention is a transmission control device that controls a continuously variable transmission mounted on a vehicle, and is used for shift control using an actual accelerator opening. A control device that sets an accelerator opening and controls the continuously variable transmission based on the accelerator opening for shift control; and the control device increases the threshold value for shifting each time the actual accelerator opening increases. In addition, the shift control accelerator opening is updated stepwise to the high opening side, the shift threshold is increased by a predetermined amount, and the predetermined amount is set larger as the driver's acceleration intention is smaller. To do.

  According to the above configuration, every time the actual accelerator opening increases and reaches the shift threshold, the shift control accelerator opening is updated stepwise on the high opening side (that is, step down is performed). The driver can be given a direct acceleration feeling when the accelerator is depressed.

  Further, the threshold for shifting is increased by a predetermined amount together with the update, and the predetermined amount is set to be larger as the driver's acceleration intention is smaller, so that the step down execution timing can be delayed as the driver's acceleration intention is smaller, A driver's uncomfortable feeling with respect to the execution timing of the step-down can be reduced.

  Further, the continuously variable transmission shift control device according to the present invention is the shift control device for the continuously variable transmission described above, wherein the control device increases the amount of change in the vehicle speed as the vehicle speed change amount increases. It is determined that the acceleration intention is small.

  According to the above configuration, as the vehicle speed change amount of the vehicle is larger, it is determined that the driver's intention to accelerate is smaller. Therefore, it is possible to accurately determine the magnitude of the driver's intention to accelerate. That is, since the amount of change in the vehicle speed is unlikely to change suddenly, the magnitude of the driver's intention to accelerate can be determined more accurately than the amount of change in the actual accelerator opening that is likely to change suddenly.

  A continuously variable transmission shift control device according to the present invention is the above-described continuously variable transmission shift control device, wherein the control device increases a vehicle speed change amount to a predetermined threshold value. The shift threshold value is increased by a certain amount each time the shift is reached.

  According to the above configuration, the shift threshold value is increased by a certain amount each time the vehicle speed change amount of the vehicle increases and reaches a predetermined threshold value, so that the shift threshold value can be increased stepwise according to the vehicle speed change amount.

  A transmission control device for a continuously variable transmission according to the present invention is the transmission control device for a continuously variable transmission described above, wherein the control device is configured to change the actual accelerator opening or the actual accelerator opening. It is determined that the driver's intention to accelerate is larger as the change rate of the vehicle is larger.

  According to the above configuration, the greater the amount of change in the actual accelerator opening or the rate of change in the actual accelerator opening, the greater the driver's intention to accelerate, so the amount of change in the actual accelerator opening or the actual accelerator The degree of acceleration intention of the driver can be determined using the change rate of the opening degree.

  According to the transmission control device for a continuously variable transmission according to the present invention, it is possible to reduce the driver's uncomfortable feeling with respect to the step-down execution timing.

1 is a schematic configuration diagram of a vehicle equipped with a transmission control device for a continuously variable transmission according to an embodiment of the present invention. 1 is a schematic configuration diagram of a transmission control device for a continuously variable transmission according to an embodiment of the present invention. It is the figure which showed an example of the time change of each physical quantity V, (DELTA) V, A, Asft, and NINtag. It is a figure explaining the time change of the physical quantity A of FIG. 3 in detail. It is a flowchart explaining the main operation | movement of the speed control apparatus of the continuously variable transmission which concerns on embodiment of this invention. It is a figure explaining each operation | movement at the time of accelerator early depressing (a) and the accelerator slow depressing (b) of the speed control apparatus of the continuously variable transmission which concerns on embodiment of this invention. It is a figure explaining the operation | movement at the time of accelerator stepping of a proposal apparatus slowly.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Description of configuration>
FIG. 1 is a schematic configuration diagram of a vehicle equipped with a continuously variable transmission control device according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a transmission control device for a continuously variable transmission according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of a time change of each physical quantity V, ΔV, A, Asft, and NINtag. FIG. 4 is a diagram for explaining in detail the time change of the physical quantity A in FIG.

  A continuously variable transmission control device 1 according to this embodiment controls a continuously variable transmission 17 mounted on a vehicle 3 as shown in FIGS. 1 and 2. As shown in FIG. 3, when the actual accelerator opening A increases and reaches the down line (shift threshold) D, the shift control device 1 performs step down and sets the down line D to the first predetermined amount ΔDa. The down line D is further raised as the vehicle speed change amount ΔV from the time of implementation (for example, time t1) to the current time t is larger (that is, the driver's intention to accelerate is smaller). Thereby, this transmission control apparatus 1 controls the execution timing of a step-down according to a driver | operator's intention of acceleration.

  Here, the relationship between the driver's intention to accelerate and the vehicle speed change amount ΔV will be described. Since the vehicle 3 is generally heavy, the vehicle speed V of the vehicle 3 does not change immediately when the accelerator is depressed. Therefore, when the accelerator is depressed quickly (that is, when the driver intends to accelerate), the vehicle speed change amount ΔV with respect to the change amount ΔA of the actual accelerator opening A becomes small. On the other hand, when the accelerator is depressed slowly (that is, when the driver's intention to accelerate is small), the vehicle speed change amount ΔV with respect to the change amount ΔA of the actual accelerator opening A increases. Accordingly, the greater the vehicle speed change amount ΔV during the accelerator operation, the smaller the driver's intention to accelerate.

  Here, in order to determine the driver's intention to accelerate, the vehicle speed change amount ΔV is used without using the change amount ΔA of the actual accelerator opening A. This is because the actual accelerator opening A changes in a short time and is not stable, so it is difficult to grasp the driver's intention to accelerate. However, since the vehicle speed change amount ΔV is less likely to change suddenly, This is because it is more suitable for grasping.

  As shown in FIGS. 1 and 2, the vehicle 3 of this embodiment includes an engine 5, drive wheels 7L and 7R, and a power transmission mechanism 9 that transmits the driving force of the engine 5 to the drive wheels 7L and 7R. A control device 11 for controlling the engine 5 and the power transmission mechanism 9 is provided.

  The engine 5 is a known internal combustion engine that outputs power by burning a fuel such as a gasoline engine or a diesel engine in a combustion chamber. The driving force of the engine 5 is output as a rotational force that rotates the crankshaft 5a. The engine 5 includes an electronically controlled throttle valve 5b that adjusts the intake air amount, a fuel injection device 5c that performs fuel injection of the engine 5, and an ignition device 5d that performs ignition of the engine 5.

  The power transmission mechanism 9 includes a torque converter 13 that transmits the driving force of the engine 5, a forward / reverse clutch 15 that switches the rotation direction of the driving force output from the torque converter 13 to a forward direction or a reverse direction, and a forward / reverse clutch 15. A continuously variable transmission 17 capable of steplessly changing the speed ratio γ when the output driving force is output to the subsequent stage, a reduction gear 19 that decelerates the driving force output from the continuously variable transmission 17, and a reduction gear And a differential gear 21 that distributes the driving force output from 19 to the driving wheels 7L and 7R.

  The torque converter 13 includes a pump impeller 13a connected to the crankshaft 5a of the engine 5, a turbine runner 13c connected to the forward / reverse clutch 15 via the turbine shaft 13b, and oil filled in the torque converter 13 (illustrated). And a lock-up clutch 13d that directly couples / releases the pump impeller 13a and the turbine runner 13c.

  In the torque converter 13, when the lock-up clutch 13d is released, the rotation of the pump impeller 13a is transmitted to the turbine runner 13c via oil, so that the driving force from the crankshaft 5a is transmitted to the forward / reverse clutch 15. . Further, when the lockup clutch 13d is in the directly connected state, the rotation of the pump impeller 13a is transmitted to the turbine runner 13c in the directly connected state without oil, so that the driving force from the crankshaft 5a is transmitted to the forward / reverse clutch 15. .

  The forward / reverse clutch 15 is configured as, for example, a double pinion type planetary gear mechanism. The forward / reverse clutch 15 includes a sun gear 15a connected to the turbine shaft 13b of the torque converter 13, a carrier 15b connected to the input shaft 17a of the continuously variable transmission 17, a ring gear 15c, the sun gear 15a, and the carrier 15b. A forward clutch 15d for engaging / releasing and a reverse brake 15e for engaging / releasing the ring gear 15c and the housing of the forward / reverse clutch 15 are provided.

  In the forward / reverse clutch 15, when the forward clutch 15d is engaged and the reverse brake 15e is released, the driving force from the torque converter 13 is rotated in the forward direction and output to the continuously variable transmission 17. When the forward clutch 15d is released and the reverse brake 15e is engaged, the driving force from the torque converter 13 is rotated in the reverse direction and output to the continuously variable transmission 17. Further, when the forward clutch 15 d is released and the reverse brake 15 e is released, the driving force from the torque converter 13 is cut off and is not output to the continuously variable transmission 17.

  The continuously variable transmission 17 is configured as, for example, a belt-type continuously variable transmission. The continuously variable transmission 17 includes an input shaft 17a connected to the carrier 15b of the forward / reverse clutch 15, an output shaft 17b connected to the reduction gear 19, a primary pulley 17c connected to the input shaft 17a, and an output shaft 17b. A secondary pulley 17d connected to each other, and a transmission belt 17e wound between the pulleys 17c and 17d.

  In this continuously variable transmission 17, the transmission belt 17e circulates and rotates the secondary pulley 17d by the rotation of the primary pulley 17c. As a result, the driving force output from the forward / reverse clutch 15 is output to the reduction gear 19. At that time, the groove widths of the pulleys 17c and 17d are controlled according to the control of the control device 11, and the engagement diameter of the transmission belt 17e is changed. As a result, the gear ratio γ (= the rotational speed NIN of the input shaft 17a / the rotational speed NOUT of the output shaft 17b) is continuously changed.

  For example, a vehicle speed sensor S1, an accelerator opening sensor S2, a shift position sensor S3, and an output shaft rotation speed sensor S4 are connected to the control device 11 as various sensors.

  The vehicle speed sensor S <b> 1 detects the vehicle speed V of the vehicle 3. The accelerator opening sensor S2 detects an accelerator opening (amount of accelerator depression by the driver) A. Hereinafter, the detected value of the accelerator opening sensor S2 is referred to as an actual accelerator opening A. The shift position sensor S3 detects the operation position P of the shift lever operated by the driver. The output shaft rotational speed sensor S4 detects the rotational speed of the output shaft 17b (that is, the rotational speed of the secondary pulley 17d) NOUT. Detection values of the sensors S1 to S4 are output to the control device 11.

  The control device 11 controls the engine 5, the torque converter 13, the forward / reverse clutch 15 and the continuously variable transmission 17 based on the detection values of the sensors S1 to S4. The control device 11 includes an engine control unit 23 that controls the engine 5, a torque converter control unit 25 that controls the torque converter 13, a forward / reverse clutch control unit 27 that controls the forward / reverse clutch 15, and a continuously variable transmission 17. And a shift control unit 29 for controlling.

  The torque converter control unit 25 controls the direct connection / release of the lockup clutch 13d of the torque converter 13 based on the vehicle speed V, for example. Further, the forward / reverse clutch 15 controls the engagement / release of each of the forward clutch 15d and the reverse brake 15e of the forward / backward clutch 15 based on the operation position P of the shift lever, for example.

  Based on the vehicle speed V and the actual accelerator opening A, the engine control unit 23 performs the opening control of the electronic control throttle valve 5b, the fuel injection control of the fuel injection device 5c, and the ignition control of the ignition device 5d. Control the driving force.

  More specifically, the engine control unit 23 uses the actual accelerator opening A to set the throttle control accelerator opening Ath. Here, the engine control unit 23 sets the actual accelerator opening A as it is to the throttle control accelerator opening Ath. Thus, the throttle opening Ath for throttle control changes in the same manner as the actual accelerator opening A.

  Further, the engine control unit 23 controls the electronic control throttle valve 5b so that the opening degree of the electronic control throttle valve 5b (hereinafter referred to as the throttle opening degree θ) becomes an opening degree corresponding to the throttle opening degree Ax for throttle control. Control. Thus, the throttle opening θ is increased according to the accelerator depression amount by the driver.

  The shift control unit 29 sets the shift control accelerator opening Asft using the actual accelerator opening A, and controls the gear ratio γ based on the shift control accelerator opening Asft.

  Note that the shift control unit 29 includes, for example, a power mode switch (not shown), a continuously variable transmission mode for continuously changing the speed ratio γ based on the optimum fuel consumption line, and a stepped speed change for the speed ratio γ. The stepped transmission mode to be selected is set to be selectable. The shift control unit 29 performs the following operation when, for example, the power mode switch is on and the stepped shift mode is selected.

  That is, as shown in FIG. 3, the shift control unit 29 initially sets the shift control accelerator opening Asft and defines the update timing of the shift control accelerator opening Asft (that is, the step-down execution timing). The down line D is initialized (for example, time t0). The initial set value of the shift control accelerator opening Asft is, for example, the same value as the actual accelerator opening A at the time of initial setting (for example, time t0).

  Further, the shift control unit 29 maintains the shift control accelerator opening Asft as it is until the actual accelerator opening A increases and reaches the down line D (for example, time t0 to t1). Further, the shift control unit 29 sets the shift control accelerator opening Asft to the same value as the actual accelerator opening A (for example, every time the actual accelerator opening A increases and reaches the down line D (for example, times t1 and t7). That is, it is updated stepwise on the high opening side.

  Further, the shift control unit 29 raises the down line D by the first predetermined amount ΔDa (that is, stepwise) with the update (that is, the value of the down line D is changed from D to D + ΔDa). Further, the shift control unit 29 obtains the vehicle speed change amount ΔV of the vehicle 3 from the time of the update (for example, time t1) to the current time t based on the vehicle speed V, and the larger the vehicle speed change amount ΔV is (that is, the acceleration of the driver). As the intention decreases, the down line D at the current time t is further raised with respect to the down line D at the time when the first predetermined amount ΔDa is increased at the latest (for example, time t1). That is, the shift control unit 29 increases the difference (second predetermined amount) ΔDb between the value of the down line D at the current time t and the value of the down line D when the most recent first predetermined amount ΔDa increases as the vehicle speed change amount ΔV increases. The down line D at the present time t is raised so that becomes larger. As a result, the value of the down line D at the current time t becomes D + ΔDa + ΔDb.

  In other words, the shift control unit 29 raises the down line D by a predetermined amount (ΔDa + ΔDb (for example, ΔDb = 0 at the time of this update)) along with the update, and the greater the vehicle speed change amount ΔV is (that is, the driver's intention to accelerate is smaller). By setting the second predetermined amount ΔDb to a large value, the predetermined amount (ΔDa + ΔDb) is set to a large value.

  More specifically, the shift control unit 29 is set with a plurality of threshold values U1 to UN (where U1 <U2 <... <UN). Here, the number of threshold values Un is plural, but may be one. As shown in FIG. 4, the shift control unit 29 keeps the down line D constant every time the vehicle speed change amount ΔV increases and reaches each of the threshold values U1 to UN (that is, every time the driver's acceleration intention is slightly reduced). Increase the amount ΔDc. In this case, the total sum of the constant amounts ΔDc raised from the most recent update time to the current time t becomes the second predetermined amount ΔDb at the current time. As a result, as the vehicle speed change amount ΔV is larger, the down line D at the current time t is further increased with respect to the down line D at the time when the first predetermined amount ΔDa is recently increased.

  In this manner, the shift control unit 29 sets the shift control accelerator opening Asft using the actual accelerator opening A. Then, the shift control unit 29 sets a target value (hereinafter referred to as a target input shaft rotational speed) NINtag of the input shaft rotational speed NIN using the shift control accelerator opening Asft. Here, as shown in FIG. 3, the shift control unit 29 sets the target input shaft rotational speed NINtag to a larger value as the shift control accelerator opening Asft is larger. Specifically, the shift control unit 29 sets the target input shaft rotational speed NINtag using Equation 1, for example.

NINtag = Nbase + ΔN (Asft) + ΔN (NOUT)... Formula 1
Note that Nbase in Equation 1 is a fixed value that serves as a base for the target input shaft rotational speed NINtag. ΔN (Asft) is a correction value for changing the target input shaft rotational speed NINtag in accordance with the change in the shift control accelerator opening Asft. ΔN (NOUT) is set so that the speed ratio γ does not change while the speed control accelerator opening Asft does not change, or the speed ratio γ changes (for example, increases or decreases) while the speed control accelerator opening Asft does not change. This is a correction value for adjusting the target input shaft rotational speed NINtag in accordance with the change in the vehicle speed V (that is, the output shaft rotational speed NOUT).

  That is, the shift control unit 29 obtains a correction value ΔN (Asft) corresponding to the shift control accelerator opening Asft using a preset map, and also calculates a correction value ΔN (NOUT corresponding to the output shaft rotational speed NOUT. ) Then, the shift control unit 29 obtains the target input shaft rotational speed NINtag by substituting the correction values ΔN (Asft) and ΔN (NOUT) into Equation 1.

  Further, the shift control unit 29 controls the continuously variable transmission 17 so that the input shaft rotational speed NIN matches the target input shaft rotational speed NINtag. Here, as shown in FIG. 3, since the shift control accelerator pedal opening Asft is changed in a step shape, the target input shaft rotational speed NINtag is also changed in a step shape. As a result, the gear ratio γ is also changed stepwise. That is, a downshift (switching from a high speed stage to a low speed stage) is performed in a step-like manner (this step-like downshift is called a step-down).

  Here, the shift control device 1 includes at least a vehicle speed sensor S1, an accelerator opening sensor S2, a control device 11, and a continuously variable transmission 17.

<Description of operation>
Next, the main operation of the speed change control device 1 (that is, the action of the speed change control unit 29) will be described with reference to FIG. FIG. 5 is a flowchart for explaining the main operation of the shift control apparatus 1.

  In the following description, for convenience of explanation, it is assumed that the vehicle speed V at the time of accelerator operation always increases (that is, the vehicle speed change amount ΔV always increases). The symbol n is an identification number of the threshold value Un (n = 1 to N) to be determined, and is initially set to n = 1.

  In step T1, the shift control unit 29 determines whether or not the actual accelerator opening A has increased to reach the down line D (that is, whether A ≧ D). If the determination result is affirmative (Yes), the process proceeds to step T2. On the other hand, if the determination result is negative (No), the process returns to step T1.

  In step T2, the shift control unit 29 performs step-down. That is, the shift control unit 29 updates the shift control accelerator opening Asft to, for example, the same value as the actual accelerator opening A (that is, stepped). Then, the shift control unit 29 obtains the target input shaft rotational speed NINtag based on the updated shift control accelerator opening degree Asft so that the input shaft rotational speed NIN matches the obtained target input shaft rotational speed NINtag. The continuously variable transmission 17 is controlled. As a result, the gear ratio γ changes stepwise. Then, the process proceeds to step T3.

  In step T3, the shift control unit 29 stores the vehicle speed V and the actual accelerator opening A when the step-down of step T2 is performed (that is, when the shift control accelerator opening Asft is updated) in a predetermined storage unit. Then, the process proceeds to step T4.

  In step T4, the shift control unit 29 raises the down line D by the first predetermined amount ΔDa along with the step down of step T2. As a result, the value of the down line D is changed from D to D + ΔDa. Here, the down line D is raised to the value obtained by raising the first predetermined amount ΔDa with respect to the actual accelerator opening A stored in step T3.

  In step T5, the shift control unit 29 obtains the vehicle speed change amount ΔV of the vehicle 3 from the time when the step down in step T2 is performed to the present time. Specifically, the shift control unit 29 calculates the difference between the vehicle speed V stored in step T3 and the current vehicle speed V to obtain the vehicle speed change amount ΔV. Then, the shift control unit 29 determines whether or not the vehicle speed change amount ΔV increases and reaches the threshold value Un (that is, whether ΔV ≧ Un, that is, whether the driver's acceleration intention is slightly reduced). If the determination result is negative (No), the process proceeds to step T6. On the other hand, if the determination result is affirmative (Yes), the process proceeds to step T8.

  In step T6, the shift control unit 29 maintains the down line D as it is. Then, the process proceeds to step T7.

  In step T7, the shift control unit 29 determines whether or not the actual accelerator opening A has increased and has reached the down line D (that is, A ≧ D). If the determination result is negative (No), the process returns to step T5. On the other hand, if the determination result is affirmative (Yes), the process proceeds to step T12.

  In step T8, the shift control unit 29 raises the down line D by a certain amount ΔDc. As a result, the value of the down line D becomes D + ΔDa + n × ΔDc. Then, the process proceeds to step T9.

  In step T9, the shift control unit 29 determines whether or not the actual accelerator opening A has increased and has reached the down line D (that is, whether A ≧ D). If the determination result is negative (No), the process proceeds to step T10. On the other hand, if the determination result is affirmative (Yes), the process proceeds to step T12.

  In step T10, when the identification number n of the current threshold value Un to be determined is N (Yes), the process returns to step T9. On the other hand, if the current identification number n is not N (No), the process proceeds to step T11, and the identification number n is changed to n + 1. Then, the process returns to step T5.

  In step T12, the identification number n of the current threshold value Un to be determined is reset to 1. And a process returns to step T2 and the next step down is implemented.

  Thus, in this transmission control device 1, the down line D is raised by the first predetermined amount ΔDa when the step down is performed (step T4). Further, every time the vehicle speed change amount ΔV from the time of the step down to the present time increases and reaches each threshold value Un (n = 1, 2,...) (That is, every time the driver's acceleration intention decreases little by little). ), The down line D is raised by a certain amount ΔDc (step T8). Thus, the down line D is further increased as the vehicle speed change amount ΔV is larger (that is, as the driver's intention to accelerate is smaller) after the first predetermined amount ΔDa is increased during the step-down. Thus, as the vehicle speed change amount ΔV is larger, the actual accelerator opening A becomes less likely to reach the down line D, the step-down execution timing is delayed, and the number of step-down executions is suppressed.

  Next, the time change of the down line D of FIG. 4 will be described based on the flowchart of FIG.

  When the time t is t0 ≦ t <t1, since the actual accelerator opening A does not reach the down line D, step T1 is repeated. Therefore, the step-down is not performed, and the down line D is maintained at the value D as it is. The identification number n of the threshold value Un to be determined during this time is n = 1.

  When the actual accelerator opening A increases and reaches the down line D at time t = t1, the process proceeds in the order of steps T1, T2, T3, and T4, the step down is performed, and the down line D is the first place. The fixed amount ΔDa is increased (that is, the value of the down line D is changed from D to D + ΔDa).

  Further, when the time t is t1 ≦ t <t2, since the vehicle speed change amount ΔV from the time t1 when the step down is performed to the current time t is less than the threshold value U1, the process is repeated in the order of steps T5 → T6 → T7 → T5. The down line D is maintained at the same value (D + ΔDa).

  At time t = t2, the vehicle speed change amount ΔV from the time t1 when the step-down is performed to the current time t increases to reach the threshold value U1 (that is, the driver's intention to accelerate slightly decreases). As a result, the process proceeds in the order of steps T5 → T8 → T9 → T10 → T11 → T5, and the down line D is increased by a certain amount ΔDc (that is, the value of the down line D is changed to D + ΔDa + ΔDc). The identification number n of the threshold value Un is incremented by 1 and changed to 2.

  When the time t is t2 ≦ t <t3, since the vehicle speed change ΔV from the time t1 when the step down is performed to the current time t is less than the threshold value U2, the process is repeated in the order of steps T5 → T6 → T7 → T5. The line D is maintained as it is (D + ΔDa + ΔDc).

  Thereafter, at times t = t3, t4, t5, and t6, the vehicle speed change ΔV from the step-down execution time t1 to the current time t increases to reach the threshold values U2, U3, U4, and U5, respectively. As a result, as in the case of time t1, the process proceeds in the order of steps T5 → T8 → T9 → T10 → T11 → T5, the down line D is increased by a certain amount ΔDc, and the identification number n of the threshold value Un to be determined is determined. Is changed to n + 1.

  Further, when the time t is t3 ≦ t <t4, t4 ≦ t <t5, t5 ≦ t <t6, the vehicle speed change amount ΔV from the step-down execution time t1 to the current t is less than the threshold values U3, U4, U5, respectively. Therefore, as in the case of t2 ≦ t <t3, the process is repeated in the order of steps T5 → T6 → T7 → T5, and the down line D is maintained at the same value.

  In this way, every time the vehicle speed change ΔV from the time t1 when the step-down is performed to the current time t increases and reaches each threshold value Un (n = 1, 2,...) (That is, the driver's acceleration intention decreases little by little). Every time, the down line D is raised by a certain amount ΔDc. Thus, after the down line D is increased by the first predetermined amount ΔDa, the down line D is further increased as the vehicle speed change amount ΔV is larger (that is, the driver's intention to accelerate is smaller). Thus, as the vehicle speed change amount ΔV is larger, the actual accelerator opening A becomes less likely to reach the down line D, the step-down execution timing is delayed, and the number of times of step dyne is suppressed.

  When the actual accelerator opening A increases and reaches the down line D at time t7, the process proceeds in the order of steps T9 → T12 → T2 → T3 → T4. Thereby, the identification number n of the threshold value Un to be determined is reset to 1. Then, as in the case of time t1, step down is performed and the down line D is raised by the first predetermined amount ΔDa. Thereafter, the same processing is repeated.

  FIG. 6 is a diagram for explaining the operation of the shift control device 1 when the accelerator is depressed early (a) and when the accelerator is depressed slowly (b). FIG. 7 is a diagram for explaining the operation of the proposed device when the accelerator is slowly depressed. In FIG. 6 and FIG. 7, the step-down is performed at each time t10, t11, t12, t13, t14, t18, t19, t20.

  In this speed change control device 1, when the vehicle speed change amount ΔV is relatively small, such as when the driver depresses the accelerator early (that is, when the driver intends to accelerate), as shown in FIG. The down line D is hardly raised until the next down step is performed after the first predetermined amount ΔDa is raised when the step down is performed. Thereby, the execution timing of the step-down is not delayed, and a direct acceleration feeling can be given to the driver.

  On the other hand, in this speed change control device 1, when the vehicle speed change amount ΔV is relatively large as in the case where the driver slowly depresses the accelerator (that is, when the driver's intention to accelerate is small), FIG. 6B shows. As described above, the down line D is further increased as the vehicle speed change amount ΔV increases after the first predetermined amount ΔDa is increased when the step down is performed and until the next down step is performed. As a result, the greater the vehicle speed change amount ΔV (that is, the smaller the driver's intention to accelerate) is, the later the step down execution timing is delayed, and the driver's discomfort with respect to the step down execution timing is reduced. Furthermore, it is possible to suppress giving the driver a feeling of shifting busy. Furthermore, it is possible to avoid a sudden step-down that is not expected for the driver, and to improve the driver's acceleration feeling.

  On the other hand, in the proposed apparatus, the down line D is increased by the first predetermined amount ΔDa at the time of step down and then the next step down regardless of the driver's intention to accelerate (that is, regardless of the vehicle speed change amount ΔV). The value is maintained as it is until the time of implementation.

  Therefore, in the proposed device, even when the vehicle speed change amount ΔV is relatively large as in the case where the driver slowly depresses the accelerator, as shown in FIG. The step-down is performed at the same actual accelerator opening A). As a result, the driver feels uncomfortable with the timing of the step-down, gives the driver a busy feeling of shifting, and causes a sudden step-down that the driver does not expect, impairing the driver's acceleration feeling. There is.

<Main effects>
According to the shift control device 1 configured as described above, every time the actual accelerator opening A rises and reaches the down line (shift threshold) D, the shift control accelerator opening Asft is set to the high opening side. Since it is updated stepwise (ie, step down is performed), the driver can be given a direct acceleration feeling when the accelerator is depressed.

  In addition, the down line D is increased by a predetermined amount (ΔDa + ΔDb (ΔDb = 0 at the time of update)) with the update, and the predetermined amount (ΔDa + ΔDb) is set larger by increasing, for example, ΔDb as the driver's intention to accelerate is smaller. Therefore, as the driver's intention to accelerate is smaller, the step-down execution timing can be delayed, and the driver's discomfort with respect to the step-down execution timing can be reduced.

  Further, since the driver's intention to accelerate is determined to be smaller as the vehicle speed change amount ΔV of the vehicle 3 is larger, the magnitude of the driver's intention to accelerate can be accurately determined. That is, since the vehicle speed change amount ΔV is unlikely to change suddenly, it is possible to accurately determine the magnitude of the driver's intention to accelerate compared to the change amount ΔA of the actual accelerator opening A that is likely to change suddenly.

  Further, every time the vehicle speed change amount ΔV of the vehicle 3 increases and reaches a predetermined threshold value Un (n = 1, 2,...), The down line D is increased by a certain amount ΔDc. Down line D can be stepped up (depending on the person ’s intention to accelerate).

  In this embodiment, the shift control unit 29 further reduces the down line D by a certain amount ΔDc every time the vehicle change amount ΔV falls below each threshold value Un (that is, every time the driver's acceleration intention slightly increases). May be. Accordingly, it is possible to cope with the case where the vehicle speed V during the accelerator operation does not always increase (that is, when the vehicle speed change amount ΔV does not always increase).

  Further, in this embodiment, the magnitude of the driver's intention to accelerate may be determined using the change amount ΔA of the actual accelerator opening A or the change rate of the actual accelerator opening A instead of the vehicle speed change amount ΔV. That is, it may be determined that the driver's intention to accelerate is larger as the change amount ΔA of the actual accelerator opening A or the change rate of the actual accelerator opening A is larger. The change amount ΔA of the actual accelerator opening A is, for example, the change amount of the actual accelerator opening A from the latest update time to the current time. The change rate of the actual accelerator opening A is the change rate of the actual accelerator opening A at each time point. Thereby, the magnitude of the driver's intention to accelerate can be determined using the change amount of the actual accelerator opening or the change rate of the actual accelerator opening.

<Modification>
In the above embodiment, the first predetermined amount ΔDa is a constant value, but may be a variable value. That is, when the down line D is increased by the first predetermined amount ΔDa, the first predetermined value ΔDa is set to, for example, the vehicle speed V (for example, the vehicle speed V at the time of the increase) and / or the vehicle speed change amount ΔV (for example, the previous first The vehicle speed change amount ΔV) from when the predetermined amount ΔDa increases to the current first predetermined amount ΔDa may be changed. In this case, the first predetermined amount ΔDa may be increased or decreased as the vehicle speed V is increased and as the vehicle speed change amount ΔV is increased.

  In the above embodiment, the constant value ΔDc is a constant value but may be a variable value. That is, when the down line D is increased by a constant value ΔDc, the constant value ΔDc is set, for example, by a vehicle speed change amount ΔV (that is, a vehicle speed change amount ΔV from the most recent first predetermined value ΔDa rise time to the present time) and a first predetermined amount. ΔDa (for example, when the first predetermined amount ΔDa is a variable value, the first predetermined amount ΔDa when the down line D is next raised by the first predetermined amount ΔDa) is divided (for example, ΔV / ΔDa (ie, driver acceleration) Based on the intention)). In this case, the constant value ΔDc may be increased or decreased as ΔV / ΔDa increases.

<Attachment>
As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to such an example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. It is understood.

  The present invention is most suitable for application to a shift control device that controls a continuously variable transmission capable of continuously changing the rotational speed of an engine.

DESCRIPTION OF SYMBOLS 1 Shift control apparatus 3 Vehicle 11 Control apparatus 17 Continuously variable transmission A Actual accelerator opening Asft Shift control accelerator opening D Down line (shift threshold)
S1 vehicle speed sensor S2 accelerator opening sensor Un threshold V vehicle speed ΔDa first predetermined amount ΔDc constant amount ΔV vehicle speed change amount

Claims (4)

A shift control device for controlling a continuously variable transmission mounted on a vehicle,
A shift control accelerator opening is set using an actual accelerator opening, and the continuously variable transmission is controlled based on the shift control accelerator opening;
The control device updates the shift control accelerator opening in a stepped manner to the high opening side and increases the shift threshold by a predetermined amount each time the actual accelerator opening increases and reaches the shift threshold. The shift control device for a continuously variable transmission, wherein the predetermined amount is set to be larger as the driver's intention to accelerate is smaller. A transmission control device for a continuously variable transmission according to claim 1,
The said control apparatus determines that the driver | operator's intention of acceleration is so small that the variation | change_quantity of the vehicle speed of the said vehicle is large, The transmission control apparatus of the continuously variable transmission characterized by the above-mentioned. A transmission control device for a continuously variable transmission according to claim 1 or 2,
The control device increases the shift threshold value by a certain amount each time the vehicle speed change amount of the vehicle increases and reaches a predetermined threshold value. A transmission control device for a continuously variable transmission according to claim 1,
The control device determines that the driver's intention to accelerate is larger as the change amount of the actual accelerator opening or the change rate of the actual accelerator opening is larger. .

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