JP2015232345A - Continuously variable transmission controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuously variable transmission controller for controlling transition to a kick-down mode without making a driver feel a discomfort.SOLUTION: It is determined whether kick-down is requested (S16, S22, S24) in accordance with a kick-down determination condition set from a vehicle velocity detected in response to a determination result as to whether it is time of starting a vehicle (S12, S18) and an accelerator operation parameter including at least an accelerator opening, a transmission gear ratio of a continuously variable transmission is controlled so that an input revolving speed from a driving source matches a kick-down-time target revolving speed on the basis of the detected vehicle velocity and the detected accelerator opening, and the kick-down determination condition is configured so that the accelerator operation parameter is set to make it more difficult to determine that the kick-down is requested if it is determined that it is the time of starting the vehicle than if it is determined that it is not the time of starting the vehicle (S16, S22, S24, S26).

Description

  The present invention relates to a control device for a continuously variable transmission, and more specifically to a control device for a continuously variable transmission configured to shift to a kick down mode under a predetermined condition.

  2. Description of the Related Art Conventionally, there is known a continuously variable transmission control device that determines whether or not to shift to a kick down (KD) mode (a mode in which a transmission is controlled to cause kick down) based on an accelerator opening. (For example, Patent Document 1). The technique described in Patent Document 1 is characterized in that it is not determined whether to shift to the kick-down mode based solely on the accelerator opening, but is determined in consideration of the road surface gradient of the running road surface. Yes, so that the driver can kick down at an appropriate timing intended by the driver.

JP 2003-172446 A

  By the way, in the control device for a continuously variable transmission, when the engine is shifted to the kick-down mode and kick-down is performed, the engine speed is increased for the purpose of improving the response to the accelerator opening (to obtain a linear feeling). It is customary to control the rise to be suppressed for a certain period.

  However, since the increase in the engine speed is suppressed, particularly when the vehicle starts, it is difficult to experience the feeling of acceleration of the vehicle and the feeling of vehicle speed, which may give the driver a sense of incongruity. That is, although the acceleration and the vehicle speed actually appear, there is a disadvantage that the driver cannot feel the acceleration feeling or the feeling of the vehicle speed because the increase in the engine speed is suppressed.

  Accordingly, an object of the present invention is to provide a control device for a continuously variable transmission that solves the above-described problems and controls the transition to the kick-down mode so as not to give the driver a sense of incongruity.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a continuously variable transmission that inputs a rotation of a drive source mounted on a vehicle and changes continuously, and a vehicle speed that indicates a traveling speed of the vehicle. Vehicle speed detecting means for detecting, accelerator opening detecting means for detecting an accelerator opening indicating an amount of depression of an accelerator pedal disposed in a driver seat of the vehicle, and at the time of starting the vehicle for determining whether or not the vehicle is in starting When the determination result of the determination means and the determination result of the vehicle start time determination means that the vehicle is at the start, the start map is selected as the shift map, and when it is determined that the vehicle is not at the start, the shift is selected. As a map, a normal map having a target rotational speed set lower than the starting map is selected, and the input rotational speed from the drive source is determined based on the detected vehicle speed and accelerator opening. In a continuously variable transmission control device comprising: a gear ratio control means for controlling a gear ratio of the continuously variable transmission so as to coincide with the target rotational speed retrieved from the selected shift map; Determining whether or not kickdown is requested by the driver of the vehicle according to a kickdown determination condition set from the detected vehicle speed and an accelerator operation parameter including at least the accelerator opening according to the determination result of the determination means Kick-down determination means, and when the kick-down determination means determines that the kick-down is requested by the kick-down determination means, based on the detected vehicle speed and accelerator opening, And controlling the transmission ratio of the continuously variable transmission so that the input rotational speed of the engine matches the target rotational speed at the time of kickdown, and the kickdown The fixed condition is that the accelerator operation parameter is set so that it is difficult to determine that the kick-down is requested when it is determined that the vehicle is at the start, compared to when it is determined that the vehicle is not at the start. It was configured as follows.

  In the control device for a continuously variable transmission according to claim 2, the gear ratio control means determines that the kick down is requested by the kick down determination means, and determines that the vehicle is in a starting state. In this case, the kick-down target rotational speed is determined based on the target rotational speed retrieved from the normal map.

  The control device for the continuously variable transmission according to claim 3 is configured such that the accelerator operation parameter is the accelerator opening.

  The control device for the continuously variable transmission according to claim 4 is configured such that the accelerator operation parameter is the accelerator opening and its change amount.

  In the continuously variable transmission control device according to claim 1, the continuously variable transmission control device is set from a vehicle speed detected in accordance with a determination result of whether or not the vehicle is starting and an accelerator operation parameter including at least an accelerator opening. It is determined whether or not a kick-down is requested by the driver of the vehicle according to the kick-down determination condition. When it is determined that the kick-down is requested, the input from the driving source is based on the detected vehicle speed and the accelerator opening. The gear ratio of the continuously variable transmission is controlled so that the rotation speed matches the target rotation speed at the time of kickdown, and the kickdown determination condition determines that the vehicle is not at the start when it is determined that the vehicle is at the start The accelerator operation parameters are set so that it is difficult to determine that a kick down is required compared to the case where the vehicle is started. It becomes possible difficult, it is possible to suppress the phenomenon such as elongation sense acceleration feeling and the vehicle speed of the vehicle can not be obtained. In other words, the accelerator operation parameter is set so that it is difficult to determine that the kick-down is requested when the vehicle is starting, so the transition to the kick-down mode is controlled so as not to give the driver a sense of incongruity. be able to.

  In the continuously variable transmission control device according to claim 2, when it is determined that the kick-down is requested and it is determined that the vehicle is in a starting state, based on the target rotational speed retrieved from the normal map. Since it is configured to determine the target rotational speed at the time of kickdown, in addition to the above-described effect, when shifting to the kickdown mode, the engine rotational speed (input rotational speed from the drive source) is suddenly increased (feeling of rising) Response deterioration can be prevented.

  That is, when the target speed at kickdown is determined based on the target speed searched from the start map, the target speed searched from the start map is higher than the target speed searched from the normal map. Since it is set, the target speed during kickdown is also set to a high speed. However, if the target engine speed during kickdown is set to a high engine speed, the engine speed is made to follow the target engine speed during kickdown set to a high engine speed. Impress the driver. In addition, as the target speed at kickdown is set to a higher speed, the time until the actual engine speed reaches the target speed at kickdown becomes longer and the response is worsened.

  However, even when the start map is selected as in the present invention, the target speed at the time of kickdown is determined based on the target speed searched from the normal map, not from the start map. Thus, the target rotational speed at the time of kickdown can be suppressed to a lower rotational speed, so that it is possible to prevent a feeling of engine blow-up and a deterioration in response.

  In the continuously variable transmission control device according to claim 3, since the accelerator operation parameter is configured to be the accelerator opening, in addition to the above-described effects, it is determined whether or not the driver has requested kickdown. Can be judged well.

  In the continuously variable transmission control device according to claim 4, since the accelerator operation parameter is configured to be the accelerator opening and the amount of change thereof, in addition to the above-described effect, has the driver requested kickdown? Whether or not can be determined with higher accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an overall control device for a continuously variable transmission according to an embodiment of the present invention. It is explanatory drawing explaining the characteristic of the shift map used with the shift controller shown in FIG. It is a flowchart which shows operation | movement of the shift controller shown in FIG. FIG. 3 is an explanatory diagram for explaining a start-time KD determination threshold value and a normal time KD determination threshold value in the flowchart of FIG. 3. FIG. 3 is a sub-routine flow chart showing processing in a kick-down mode of the flow chart of FIG. 6 is a time chart for explaining the processing of the flowcharts of FIGS. 3 and 5. 7 is a time chart similar to FIG. 6 for explaining a part of the processing of the flow charts of FIGS. 3 and 5. 7 is an explanatory diagram for explaining in more detail the target rotational speed at the time of kickdown of the time chart.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment for implementing a continuously variable transmission control device according to the invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing the overall control device of a continuously variable transmission according to an embodiment of the present invention.

  In FIG. 1, reference numeral 10 denotes an engine (an internal combustion engine (drive source)). The engine 10 is mounted on a vehicle 14 provided with drive wheels 12 (the vehicle 14 is partially indicated by the drive wheels 12 and the like).

  The throttle valve 16 disposed in the intake system of the engine 10 is disconnected from the accelerator pedal 18 disposed on the floor surface of the vehicle driver's seat and the DBW (Drive By Wire) mechanism 20 including an actuator such as an electric motor is disconnected. And is opened and closed by the DBW mechanism 20.

  The intake air metered by the throttle valve 16 flows through an intake manifold (not shown) and is mixed with fuel injected from an injector (not shown) near the intake port of each cylinder to form an air-fuel mixture. When an intake valve (not shown) is opened, it flows into the combustion chamber of each cylinder. In the combustion chamber, the air-fuel mixture is ignited and burned by a spark plug (not shown), and after driving the piston and rotating the output shaft 22 connected to the crankshaft (not shown), it becomes exhaust and becomes an engine. 10 is discharged to the outside.

  The rotation of the output shaft 22 is input to a continuously variable transmission (hereinafter referred to as “CVT”) 26 via a torque converter 24.

  The output shaft 22 is connected to the pump / impeller 24a of the torque converter 24, while the turbine runner 24b disposed opposite to the pump shaft and the impeller 24a is connected to the main shaft (input shaft) MS. The torque converter 24 includes a lockup clutch 24c.

  The CVT 26 is a main shaft MS, more precisely, a drive pulley 26a disposed on the outer peripheral side shaft, and a counter shaft (output shaft) CS parallel to the main shaft MS, more precisely, a driven disposed on the outer peripheral side shaft. A pulley 26b and a power transmission element composed of an endless flexible member hung between the pulley 26b, for example, a metal belt 26c.

  The drive pulley 26a is fixed to the stationary pulley half 26a1 which is disposed so as not to be rotatable relative to the outer peripheral shaft of the main shaft MS and is not movable in the axial direction, and to the fixed pulley half 26a1 which is not rotatable relative to the outer peripheral shaft of the main shaft MS. A movable pulley half 26a2 that is relatively movable in the axial direction and a side of the movable pulley half 26a2, and when hydraulic pressure is supplied, presses the movable pulley half 26a2 toward the fixed pulley half 26a1. And a hydraulic actuator 26a3.

  The driven pulley 26b includes a fixed pulley half 26b1 that is not rotatable relative to the outer peripheral shaft of the counter shaft CS and is not movable in the axial direction, and an axial direction relative to the fixed pulley half 26b1 that is not rotatable relative to the counter shaft CS. A movable pulley half 26b2 that is relatively movable to the movable pulley half 26b2, and a hydraulic actuator 26b3 that is provided on the side of the movable pulley half 26b2 and presses the movable pulley half 26b2 toward the fixed pulley half 26b1 when hydraulic pressure is supplied. With.

  The CVT 26 is connected to the engine 10 via a forward / reverse switching mechanism 28. The forward / reverse switching mechanism 28 includes a forward clutch 28a that allows the vehicle 14 to travel in the forward direction, a reverse brake clutch 28b that allows the vehicle 14 to travel in the reverse direction, and a planetary gear mechanism 28c disposed therebetween.

  In the planetary gear mechanism 28c, the sun gear 28c1 is fixed to the main shaft MS, and the ring gear 28c2 is fixed to the fixed pulley half 26a1 of the drive pulley 26a via the forward clutch 28a.

  A pinion 28c3 is disposed between the sun gear 28c1 and the ring gear 28c2. Pinion 28c3 is connected to sun gear 28c1 by carrier 28c4. When the reverse brake clutch 28b is operated, the carrier 28c4 is fixed (locked) thereby.

  The rotation of the countershaft CS is transmitted from the secondary shaft (intermediate shaft) SS to the drive wheels 12 via a gear. That is, the rotation of the counter shaft CS is transmitted to the secondary shaft SS via the gears 30a and 30b, and the rotation is transmitted from the differential 32 to the left and right drive wheels (only the right side) via the drive shaft (drive shaft) 34 via the gear 30c. (Shown)

  A disc brake 36 is disposed in the vicinity of four wheels including a driving wheel (front wheel) 12 and a driven wheel (rear wheel, not shown), and a brake pedal 40 is disposed on the vehicle driver's seat floor. .

  In the forward / reverse switching mechanism 28, the forward clutch 28a and the reverse brake clutch 28b are switched by the driver operating a range selector 44 provided in the vehicle driver's seat to select one of the ranges such as P, R, N, and D. It is done by selecting. The range selection by the driver's operation of the range selector 44 is transmitted to the manual valve of the hydraulic pressure supply mechanism 46.

  Although not shown, the hydraulic pressure supply mechanism 46 includes a hydraulic pump that is driven by the engine 10 to pump hydraulic oil from a reservoir and discharge it to the oil passage, and various control valves and electromagnetic valves arranged in the oil passage. The hydraulic pressure obtained by adjusting the pressure of the hydraulic oil thus supplied is supplied to the lockup clutch 24c of the torque converter 24, and the lockup clutch 24c is engaged / released.

  The hydraulic pressure supply mechanism 46 supplies hydraulic pressure to the piston chambers of the hydraulic actuators 26a3 and 26b3 of the movable pulley halves 26a2 and 26b2, and moves the movable pulley halves 26a2 and 26b2 in the axial direction. As a result, the pulley width between the pulleys 26a and 26b changes, the winding radius of the belt 26c changes, and the transmission ratio (ratio) for transmitting the rotation of the engine 10 to the drive wheels 12 is changed steplessly. In this way, the CVT 26 receives the rotation of the engine 10 and shifts continuously.

  Further, the hydraulic pressure supply mechanism 46 supplies hydraulic pressure to the forward clutch 28a of the forward / reverse switching mechanism 28 or the piston chamber of the reverse brake clutch 28b via a manual valve that operates according to the position of the range selector 44 operated by the driver. The vehicle 14 can travel in the forward direction or the reverse direction.

  A crank angle sensor 50 is provided at an appropriate position such as near the cam shaft (not shown) of the engine 10 and outputs a signal indicating the engine speed NE for each predetermined crank angle position of the piston. In the intake system, an absolute pressure sensor 52 is provided at an appropriate position downstream of the throttle valve 16 and outputs a signal proportional to the intake pipe absolute pressure (engine load) PBA.

  The actuator of the DBW mechanism 20 is provided with a throttle opening sensor 54, which outputs a signal proportional to the throttle valve opening TH through the rotation amount of the actuator.

  Further, an accelerator opening sensor (accelerator opening detecting means) 56 is provided in the vicinity of the accelerator pedal 18, and is proportional to the accelerator opening AP corresponding to the amount of depression (accelerator pedal operation amount) by the driver of the accelerator pedal 18. Output a signal. A brake switch 58 is provided in the vicinity of the brake pedal 40 and outputs an ON signal in response to the driver's operation of the brake pedal 40.

  The output of the crank angle sensor 50 and the like described above is sent to the engine controller 66. The engine controller 66 includes a microcomputer including a CPU, a ROM, a RAM, an I / O, and the like. The engine controller 66 controls the operation of the DBW mechanism 20 based on the sensor output, and injects fuel by an injector (not shown), spark plugs, and the like. Controls the ignition timing.

  The main shaft MS is provided with an NT sensor (rotational speed sensor) 70. The rotational speed of the turbine runner 24b, specifically the rotational speed NT of the main shaft MS, more specifically, the transmission input shaft rotational speed (and so on). A pulse signal indicating the input shaft rotation speed of the forward clutch 28a is output.

  An NDR sensor (rotational speed sensor) 72 is provided at an appropriate position in the vicinity of the drive pulley 26a of the CVT 26 to output a pulse signal corresponding to the rotational speed NDR of the drive pulley 26a, in other words, the output shaft rotational speed of the forward clutch 28a. To do.

  An NDN sensor (rotational speed sensor) 74 is provided at an appropriate position in the vicinity of the driven pulley 26b, and the rotational speed NDN of the driven pulley 26b, specifically, the rotational speed of the counter shaft CS, more specifically, the transmission output shaft. A pulse signal indicating the rotational speed is output.

  Further, a vehicle speed sensor (rotation speed sensor; vehicle speed detection means) 76 is provided in the vicinity of the gear 30b of the secondary shaft SS, and a pulse signal (specifically, the vehicle speed V) indicating the rotation speed and rotation direction of the secondary shaft SS. Pulse signal).

  Further, a range selector switch 80 is provided in the vicinity of the range selector 44, and outputs a signal corresponding to a range such as R, N, or D selected by the driver.

  A hydraulic pressure sensor 82 is disposed in the oil passage of the hydraulic pressure supply mechanism 46 and outputs a signal corresponding to the hydraulic pressure supplied to the piston chamber of the hydraulic actuator 26b3 of the driven pulley 26b.

  The output from the NT sensor 70 and the like described above is sent to the shift controller 90. The shift controller 90 also includes a microcomputer including a CPU, ROM, RAM, I / O, and the like, and is configured to be communicable with the engine controller 66.

  The shift controller 90 controls the forward / reverse switching mechanism 28, the CVT 26, and the torque converter 24 by exciting / de-energizing the electromagnetic valve of the hydraulic pressure supply mechanism 46 based on the detected values.

  FIG. 2 is an explanatory diagram for explaining the characteristics of the shift map used in the shift controller 90.

  As shown in FIG. 2, the shift controller 90 searches the shift map from the detected vehicle speed V and the accelerator pedal opening AP and searches for the target engine speed of the engine 10, more specifically, the engine speed NDR input to the CVT 26. Target value (hereinafter referred to as “target NDR”). Further, the shift controller 90 reduces (matches) a deviation between the target NDR and the actual rotational speed of the engine 10, more specifically, a detected value of the rotational speed NDR (hereinafter referred to as "real NDR") input to the CVT 26. The gear ratio is controlled as follows.

  The shift map includes a start map (shown by a broken line) that is used until the vehicle speed V reaches a predetermined speed after the vehicle 14 starts, that is, when the vehicle 14 is starting, and a normal time ( At least two types of normal maps (indicated by solid lines) used when shifting to normal driving are prepared.

  As shown in the figure, the start map is set so that the target NDR is higher than the normal map for the same vehicle speed V and accelerator opening AP. This is because when the vehicle 14 is started, the driver intends to accelerate the vehicle 14 by depressing the accelerator pedal 18 to some extent. Therefore, when the vehicle 14 starts, the start map in which the target NDR is set higher than normal is set. This is for the driver to experience a sense of acceleration when starting the vehicle.

  FIG. 3 is a flowchart showing the operation of the shift controller 90. The illustrated program is executed by the shift controller 90 every predetermined time.

  More specifically, in S10, the vehicle speed V, the accelerator opening AP, and the accelerator opening change amount ΔAP are detected (calculated) from the outputs of the vehicle speed sensor 76 and the accelerator opening sensor 56 (S: processing step).

  Next, in S12, it is determined (determined) whether or not the vehicle 14 is starting. This is determined by determining whether or not the detected vehicle speed V is less than a predetermined speed and the accelerator pedal opening AP is equal to or greater than a specified value.

  When the result in S12 is affirmative and it is determined that the vehicle is at the start, the process proceeds to S14, and the above-described start map is selected as the shift map.

  Next, the process proceeds to S16, where a start KD determination threshold value used for a kickdown determination condition for determining whether or not kickdown (KD) is requested by the driver at the start is selected (set). The KD determination threshold value is the threshold value (AP threshold value) of the accelerator opening AP (AP threshold value) searched based on the vehicle speed V and the threshold value (ΔAP value) of the accelerator opening change amount (depressing speed of the accelerator pedal 18). (Accordingly, the kickdown determination condition is set from the vehicle speed V, the AP threshold value, the ΔAP threshold value, the accelerator opening AP, and the accelerator opening change amount ΔAP (from these four parameters). It is determined whether kickdown is requested)). In this specification, the accelerator opening AP and the accelerator opening change amount ΔAP are referred to as “accelerator operation parameters”.

  On the other hand, when the result in S12 is negative, the program proceeds to S18, in which it is determined whether or not a predetermined condition is satisfied after the vehicle 14 has started. This is determined by determining whether the vehicle speed V is equal to or higher than the predetermined speed and the accelerator opening is less than the specified value.

  When it is determined negative in S18 and it is determined that the predetermined condition is not satisfied, it is determined that the vehicle 14 is still at the start, and the process proceeds to S12 to select a start map, whereas when the determination is YES in S18, the vehicle 14 is at the start. It is determined that the process has shifted to the normal time, and the process proceeds to S20 to select the normal map described above.

  Next, the process proceeds to S22, and the normal time KD determination threshold value is selected (set) as in S16.

  FIG. 4 is an explanatory diagram for explaining the start-time KD determination threshold value and the normal time KD determination threshold value.

  As shown in the figure, the starting KD determination threshold and the normal KD determination threshold are set differently. That is, for the same vehicle speed V, the KD determination threshold is set such that the value at start (characteristics A and A ′) is larger than the value at normal time (characteristics B and B ′). Further, the KD determination threshold value is set so that both the value at the start and the value at the normal time become smaller as the vehicle speed V increases.

  Note that only the AP threshold value (characteristics A and B) or only the ΔAP threshold value (characteristics A ′ and B ′) may be used as the KD determination threshold value. One or both may be fixed values that are the same for the vehicle speed V.

  Returning to the description of the flow chart of FIG. 3, the process then proceeds to S24, where the accelerator opening AP and the accelerator opening change amount ΔAP detected in S10 are searched from the same vehicle speed V in the characteristics shown in FIG. It is determined whether or not the AP threshold value (selected in S16 or S22) and the ΔAP threshold value (KD determination threshold value) or more.

  When the result in S24 is negative, the process skips S26, while when the result is positive, the process proceeds to S26 and shifts to a kick down (KD) mode (described later). The kick down mode means a mode for controlling the CVT 26 so as to cause a kick down as described above.

  Next, the process proceeds to S28, and shift control is performed based on the target NDR. That is, the gear ratio of the CVT 26 is controlled so that the actual NDR matches the target NDR retrieved from the start map or the normal map.

  FIG. 5 is a sub-routine flowchart showing the processing in the kick-down mode in S26 of FIG. 3, and FIG. 6 is a time chart for explaining the processing of the flowcharts of FIGS.

  As will be described below, it is determined whether or not the currently selected shift map is a start map in S100. If the determination is affirmative, the process proceeds to S102 and kicks down based on the target NDR searched from the normal map instead of from the start map. The target rotational speed (target NDR at the time of kick down; hereinafter referred to as “KD target NDR”) is calculated (determined).

  On the other hand, when the result in S100 is negative, the program proceeds to S104, where the KD target NDR is calculated (determined) based on the target NDR retrieved from the currently selected shift map (normal map in this embodiment). When there are two types of shift maps, the start map and the normal map, as in this embodiment, the processing contents of S102 and S104 are substantially the same.

  As shown in the time chart of FIG. 6, the KD target NDR calculated in S102 and S104 is a value that is decreased by multiplying the target NDR searched from the normal map by a predetermined ratio, for example, the target searched from the normal map. It is calculated to a value of about 60% to 70% of NDR.

  Next, in S106, the CVT 26 is shift-controlled based on the calculated KD target NDR. That is, as described above, the gear ratio of the CVT 26 is controlled so that the actual NDR matches the KD target NDR.

  In the time chart of FIG. 6, the processing from time t1 to t2 corresponds to that. As shown in the figure, during this period, the target NDR during KD has a steep value, so that the actual NDR is also increased accordingly.

  Next, in S108, control is performed so that the KD target NDR, which has been reduced compared to the target NDR, is increased at a constant slope. In the time chart of FIG. 6, the processing from time t2 to t3 corresponds to that. As disclosed, the actual NDR is also raised following the KD target NDR.

  Next, in S110, it is determined whether or not the KD target NDR exceeds the target NDR by α. If the determination is negative, the process returns to S108 and the above processing is continued.

  On the other hand, when the result in S110 is affirmative, it is determined that the kick-down mode has ended, and the process proceeds to S112, and the actual NDR is searched from the start map or the normal map as in the process of S28 in the flowchart of FIG. The gear ratio of the CVT 26 is controlled so as to match.

  Here, the processing of the flowcharts of FIGS. 3 and 5 will be described. In the flowchart of FIG. 3, a value larger than the normal KD determination threshold value is selected as the start KD determination threshold value in S16, and S24 is performed. Whether or not the kickdown is requested by comparing the accelerator opening AP or the accelerator opening change amount ΔAP detected in step 1 with the selected start KD determination threshold value (accelerator operation parameter retrieved based on the vehicle speed V). Therefore, when it is determined that the vehicle 14 is at the time of starting, it is more difficult to shift to the kick-down mode than when the vehicle 14 is determined not to be at the time of starting (normal time) (kick It is difficult to determine that a down is requested.

  In addition, since both the starting KD determination threshold and the normal KD determination threshold are set to increase as the vehicle speed decreases, the lower the vehicle speed, the more difficult it is to shift to the kick-down mode.

  Next, the processing of the flowchart of FIG. 5 will be described with reference to FIGS. FIG. 7 is a time chart for explaining a part of the processing of the flow charts of FIG. 3 and FIG. 5, and FIG. 8 is an explanatory view for explaining the KD target NDR of the time chart of FIG.

  As shown as a reference example (characteristic C) in FIG. 7, it is conceivable to immediately shift to the kick-down mode when the condition is satisfied when the vehicle 14 starts (time t01). Until the time t1, even if the accelerator pedal 18 is depressed, the actual NDR does not increase, and the driver cannot feel the acceleration feeling of the vehicle 14 or the feeling of elongation of the vehicle speed V.

  In contrast, in this embodiment, as described above, it is difficult to shift to the kick-down mode when the vehicle 14 is started, and as shown in the characteristic D, the accelerator opening AP determined by the vehicle speed V at time t01 or The accelerator opening change amount ΔAP is configured not to shift to the kick-down mode (S16 and S24 in the flowchart of FIG. 3). As a result, the actual NDR increases in accordance with the amount of depression of the accelerator pedal 18 from time t01 to t1, so that it is possible to give the driver a feeling of acceleration of the vehicle 14 and a feeling of elongation of the vehicle speed V. The transition to the kick down mode at time t1 is as described above.

  However, as shown in the characteristic E of FIG. 8, when the target NDR at KD is set (calculated) based on the target NDR searched by the start map (the target NDR at KD is 60% of the target NDR searched by the start map) Since the target NDR searched by the start map is originally set higher, the target NDR during KD also corresponds to the target NDR of the start map set higher. Higher rotation speed. For this reason, when kicking down, the actual NDR rises rapidly, and there is an inconvenience that gives the driver a feeling of blowing up the engine 10.

  In addition, when the KD target NDR is set to a high rotational speed, it takes time for the actual NDR to reach the KD target NDR, and the driver is given an impression that the response deteriorates accordingly.

  In view of that point, as described with reference to FIG. 5, in this embodiment, as shown in the characteristic F of FIG. 8, even when the start map is selected when kickdown is requested, Rather than calculating the KD target NDR based on the target NDR searched on the start map, the KD target NDR is calculated based on the target NDR searched on the normal map (60 of the target NDR searched on the normal map) Shifting control is performed by calculating the target NDR during KD as a rotational speed of about 70% to 70% (S100 to S106 in the flowchart of FIG. 5).

  That is, since the target NDR searched for in the normal map is set to a lower rotational speed than the target NDR searched for in the start map, the KD target NDR calculated based on the target NDR searched in the normal map is also , It becomes lower than the target NDR at the time of KD calculated based on the target NDR searched in the start map, and the occurrence of the feeling of blowing up of the engine 10 as in the case of using the target NDR at KD based on the start map is eliminated. be able to.

  Furthermore, since the shift control is performed on the KD target NDR based on the target NDR searched by the normal map, the actual NDR can reach the KD target NDR earlier, and the feeling of response given to the driver is also improved. Can be made.

  Thus, in this embodiment, when the vehicle 14 is starting, it is difficult to shift to the kick-down mode, so that the acceleration feeling of the vehicle 14 and the increase in the vehicle speed V corresponding to the depression amount of the accelerator pedal 18 are achieved. On the other hand, when the accelerator pedal 18 is further depressed, a response intended by the driver is realized by shifting to the kick-down mode and kicking down.

  As described above, in this embodiment, the continuously variable transmission (CVT) 26 that inputs the rotation of the drive source (engine) 10 mounted on the vehicle 14 to change continuously, and the traveling speed of the vehicle A vehicle speed detecting means (vehicle speed sensor S10) 76 for detecting a vehicle speed V indicating an accelerator opening degree detecting means (accelerator position detecting means (accelerator position detecting means) for detecting an accelerator opening degree AP indicating an amount of depression of an accelerator pedal 18 disposed in a driver seat of the vehicle Opening degree sensor S10) 56, vehicle start time determination means (S12, S18) for determining whether or not the vehicle is at the start, and the determination result of the vehicle start time determination means that the vehicle is at the start When it is determined, the start map is selected as the shift map, while when it is determined that the vehicle is not at the start, the target rotation speed (target ND) is set as the shift map rather than the start map. ) Is set to a low value, and the input rotational speed (actual NDR) from the drive source is searched from the selected shift map based on the detected vehicle speed and accelerator opening. In a continuously variable transmission control device (shift controller) 90 comprising speed ratio control means (S14, S20, S28) for controlling the speed ratio of the continuously variable transmission so as to coincide with a target rotational speed, the vehicle Whether kick-down is requested by the driver of the vehicle according to a kick-down determination condition set based on the detected vehicle speed and an accelerator operation parameter including at least the accelerator opening according to the determination result of the starting time determination means Kickdown determination means (S16, S22, S24) for determining whether the gear ratio control means is controlled by the kickdown determination means. When it is determined that the kick-down is requested, the input rotational speed from the drive source matches the target rotational speed at kick-down (target NDR at KD) based on the detected vehicle speed and accelerator opening. And the kickdown determination condition is greater than when the vehicle is at the start and when the vehicle is at the start, the kickdown determination condition is Since the accelerator operation parameters are set so that it is difficult to determine that the down is requested (S16, S22, S24, S26, S100 to S110), the vehicle 14 is unlikely to be kicked down when the vehicle 14 starts. Thus, it is possible to suppress such an event that a feeling of acceleration or a feeling of elongation of the vehicle speed V cannot be obtained. That is, when the vehicle 14 is at the start, the accelerator operation parameter is set so that it is difficult to determine that the kick down is requested, so the transition to the kick down mode is controlled so as not to give the driver a sense of incongruity. can do.

  The gear ratio control means is based on a target rotational speed searched from the normal map when it is determined that the kick down is requested by the kick down determination means and the vehicle is in a starting state. (S26, S100, S102, S106), in addition to the effects described above, when the engine is shifted to the kickdown mode, the engine 10 feels up and the response is deteriorated. Can be prevented.

  That is, when the KD target NDR is determined based on the target NDR searched from the start map, the target NDR searched from the start map is set to a higher rotational speed than the target NDR searched from the normal map. , KD target NDR is also set to a high rotational speed. However, when the KD target NDR is set to a high rotational speed, the actual NDR is caused to follow the KD target NDR set to a high rotational speed, so that the driver feels as if the engine 10 has been blown up. . Further, as the KD target NDR is set to a higher rotational speed, the time until the actual NDR reaches the KD target NDR becomes longer, and the response is also worsened.

  However, even when the start map is selected as in the present invention, the KD time target NDR is determined based on the target NDR searched from the normal map, not from the start map, so that the KD time The target NDR can be suppressed to a lower rotational speed, and the feeling of the engine 10 blowing up and the deterioration of the response can be prevented.

  Further, since the accelerator operation parameter is configured to be the accelerator opening, in addition to the above-described effects, it can be accurately determined whether or not the driver has requested kickdown.

  Further, since the accelerator operation parameter is configured to be the accelerator opening and its change amount, in addition to the above-described effects, it can be more accurately determined whether or not the driver has requested kick-down.

  In the above, as shown in FIG. 6, after kicking down, the KD target NDR is controlled to increase with a predetermined inclination. However, this inclination may be any value, It is not limited to inclination.

  Further, the target NDR at the time of KD is set to the rotational speed of about 60% to 70% of the target NDR searched by the start map or the normal map, but this numerical value is an example and is not limited.

  Moreover, although the specific speed was also shown with the specific numerical value, this numerical value is also an illustration and is not limited.

  Further, although the metal belt 26c is disclosed as the power transmission element of the CVT 26, it is not limited thereto, and may be a chain type, for example.

  DESCRIPTION OF SYMBOLS 10 engine (internal combustion engine, drive source), 12 drive wheel, 14 vehicle, 18 accelerator pedal, 20 DBW mechanism, 24 torque converter, 26 continuously variable transmission (CVT), 28 forward / reverse switching mechanism, 46 hydraulic supply mechanism, 56 Accelerator opening sensor (accelerator opening detecting means), 66 engine controller, 72 NDR sensor, 76 vehicle speed sensor (vehicle speed detecting means), 90 shift controller

Claims (4)

  A continuously variable transmission that inputs a rotation of a drive source mounted on a vehicle to change continuously, vehicle speed detecting means for detecting a vehicle speed indicating the traveling speed of the vehicle, and an accelerator disposed in a driver seat of the vehicle Accelerator opening degree detecting means for detecting an accelerator opening degree indicating the depression amount of the pedal, vehicle starting time determining means for determining whether or not the vehicle is at the start, and the determination result of the vehicle starting time determining means, When it is determined that the vehicle is starting, a start map is selected as a shift map. On the other hand, when it is determined that the vehicle is not starting, a normal map in which the target speed is set lower than the start map as the shift map. And the target rotational speed at which the input rotational speed from the drive source is retrieved from the selected shift map based on the detected vehicle speed and accelerator opening. In a control device for a continuously variable transmission comprising a gear ratio control means for controlling the gear ratio of the continuously variable transmission so as to match, the vehicle speed detected according to the determination result of the vehicle start time determination means The gear ratio control means comprises kick down determination means for determining whether or not a kick down is requested by a driver of the vehicle according to a kick down determination condition set from an accelerator operation parameter including at least the accelerator opening. When the kickdown determination means determines that the kickdown is requested, the input rotational speed from the drive source matches the target rotational speed at the time of kickdown based on the detected vehicle speed and accelerator opening. As described above, the gear ratio of the continuously variable transmission is controlled, and the kick-down determination condition is determined when the vehicle is determined to start. , Compared to a case where the vehicle is determined not at the time of starting, the control device for a continuously variable transmission the accelerator operation parameters as difficult to be determined with the kick-down is requested, characterized in that it is set.   The speed ratio control means determines that the kick down is requested by the kick down determination means, and when the vehicle is determined to be in a start, based on the target rotational speed retrieved from the normal map, 2. The control device for a continuously variable transmission according to claim 1, wherein the target rotational speed at the time of kickdown is determined.   3. The continuously variable transmission control device according to claim 1, wherein the accelerator operation parameter is the accelerator opening.   3. The continuously variable transmission control device according to claim 1 or 2, wherein the accelerator operation parameter is the accelerator opening and its change amount.

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