JP2006097789A - Shift control device for continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a driver to recognize automatic release of temporary manual shift mode and switch to automatic shift mode satisfactorily without giving sense of incongruity to the driver. <P>SOLUTION: This shift control device for the continuously variable transmission has the automatic shift mode for setting a change gear ratio i of the continuously variable transmission automatically and the temporary manual shift mode for selecting a plurality of fixed change gear ratios set in advance during running in the automatic shift mode by operating a shift switch. When release conditions for the temporary manual shift mode are satisfied to switch to the automatic shift mode, final target number of revolutions of an engine Neo is set (S15) based on an operation condition. The change gear ratio i is changed per computation cycle by variation Δi of change gear ratio being a small value (S18) to converge into the final target number of revolutions of the engine Neo to control so that the number of revolutions of the engine Ne is gradually converged into the final target number of revolutions of the engine Neo. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmission control device for a continuously variable transmission that includes an automatic transmission mode and a temporary manual shift mode that temporarily switches to a manual shift during operation in the automatic transmission mode.

  In general, a continuously variable transmission mounted on a vehicle refers to a shift schedule map using the throttle opening and the vehicle speed as parameters, and determines the final target engine speed (or the final target turbine speed of the torque converter) and continuously variable speed. The final target value such as the final target speed ratio of the transmission is set, and the current engine speed (or turbine speed of the torque converter), the speed ratio of the continuously variable transmission, etc. are converged to the final target value. Gear ratio change restriction control is performed to change the gear ratio at a preset time change rate.

  By the way, in a vehicle equipped with a normal automatic transmission that employs a multi-stage transmission such as a planetary gear mechanism, the driver operates a manual switch provided separately from the select lever or the select lever, so that a normal automatic transmission is performed. There are some that are equipped with a manual shift mode that allows the driver to arbitrarily select a gear position, such as a manual transmission (MT) vehicle.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 10-141485), a sub-select gate is provided beside the main select gate for sliding the select lever, and when the select lever is tilted to the sub-select gate side, the mode detection switch is selected. When the lever is detected, the shift mode is switched to the manual shift mode. And, by tilting the select lever back and forth in the sub-select gate and selectively turning on the upshift switch and the downshift switch, the technology can shift the shift stage up or down according to the driver's intention. It is disclosed. In this case, when the select lever is returned to the main select gate, the movement is detected by the mode detection switch, and the manual shift mode can be canceled.

  On the other hand, in the manual shift mode adopted for continuously variable transmissions, the shift control is switched to manual shift mode by tilting the select lever, and the gear ratio is changed stepwise like a normal multi-stage transmission. A fixed gear ratio to be fixed is set. When the select lever is returned from this state, the manual shift mode is canceled and the gear ratio is changed by the gear ratio change restriction control to return to the gear ratio in the automatic gear shift mode set according to the current operating state. It is.

  By the way, in a vehicle equipped with a normal automatic transmission, an upshift switch or a downshift switch provided on a steering handle or the like is pushed in a state in which the selection lever is selected without tilting the select lever. Thus, there are some which have a so-called temporary manual shift mode in which the shift stage is temporarily downshifted or upshifted.

  In such a temporary manual shift mode, it is impossible to clearly indicate the driver's intention to cancel by returning the select lever as in the above-described manual shift mode. Therefore, the cancellation condition is based on the parameter indicating the driving state. Is determined.

The release condition is, for example, that acceleration / deceleration operation at a predetermined acceleration or lower than the deceleration has continued for a certain period of time. There are cases where a predetermined time or more has elapsed since then, or the vehicle speed has become a predetermined vehicle speed or less, and one or a plurality of these release conditions are employed in combination. Then, when one of the adopted release conditions is satisfied, control for automatically returning to the D range mode is performed.
Japanese Patent Laid-Open No. 10-141485

  However, when the above-described temporary manual shift mode is adopted for a continuously variable transmission, the release condition is determined from driving parameters such as acceleration / deceleration, accelerator operation, and vehicle speed as described above. Even if the temporary manual shift mode is canceled and the D range mode is automatically restored, the driver cannot recognize that the mode has been shifted to the D range mode. For this reason, the driver feels uncomfortable as if the gear ratio is rapidly changed at a timing not intended by the driver.

  In view of the above circumstances, the present invention allows the driver to recognize that the temporary manual shift mode has been automatically released even when the so-called temporary manual shift mode is adopted in the continuously variable transmission. An object of the present invention is to provide a transmission control device for a continuously variable transmission that does not give the driver a sense of discomfort when switching to an automatic transmission mode.

  To achieve the above object, the present invention provides an automatic transmission mode for automatically setting a transmission ratio of a continuously variable transmission based on an operating state, and a plurality of fixed transmission ratios preset during execution of the automatic transmission mode. Mode-specific shift control means having a temporary manual shift mode that can be selected by the operation, a release condition determining means for determining a release condition for the temporary manual shift mode according to the operating state, and when the release condition is satisfied Steplessly provided with a gear ratio change limiting means for setting a final target value of the gear ratio based on the driving state and changing the gear ratio at a gear ratio change amount every calculation cycle so as to converge to the final target value. In the transmission control device of the transmission, the transmission ratio change limiting means automatically changes the transmission ratio change amount from the manual shift mode by manual operation. Set at less than the value to return to the over-de, the transmission ratio is characterized in that a longer time to converge to the final target speed ratio.

  According to the present invention, even when a so-called temporary manual shift mode is adopted for a continuously variable transmission, the driver can be made aware that the temporary manual shift mode has been automatically released, and It is possible to improve the switching from the temporary manual shift mode to the automatic transmission mode without giving the driver an uncomfortable feeling when switching to the transmission mode.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 5 show a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a continuously variable transmission.

  Reference numeral 1 in FIG. 1 denotes an engine, and an output shaft of the engine 1 is connected to a forward / reverse switching device 4 provided in the continuously variable transmission 3 via a starting clutch 2 such as an electromagnetic clutch or a torque converter.

  The forward / reverse switching device 4 is connected to a pulley input shaft 5b that supports the primary pulley 5a of the continuously variable transmission 3, and is connected to a pulley output shaft 5c arranged in parallel to the pulley input shaft 5b. A pulley 5d is attached to the shaft, and a drive belt 5e is wound around the pulleys 5a and 5d.

  Further, the pulley output shaft 5c is connected to the differential device 6b through the reduction gear group 6a of the final reduction device 6, and the drive shaft 7 is attached to the differential device 6b so that the front wheels or the rear drive wheels 7a are attached to the differential device 6b. Has been.

  In the continuously variable transmission 3, the pulley groove width is set by the primary pressure supplied to the primary hydraulic chamber 5f provided in the primary pulley 5a. Moreover, tension required for torque transmission is applied to the secondary pulley 5d by the secondary pressure supplied to the secondary hydraulic chamber 5g provided in the secondary pulley 5d. The primary pressure and the secondary pressure are set based on the engine operation state in a transmission control unit (TCU) 21 to be described later, and the groove widths of both pulleys 5a and 5d provided in the continuously variable transmission 3 are set in an inversely proportional state. The gear ratio is obtained.

  The TCU 21 is mainly composed of a computer such as a microcomputer, and has an engine speed sensor 31 for detecting the speed Ne of the engine 1 (engine speed) Ne and an opening degree of a throttle valve (not shown) on its input side. A throttle opening sensor 32 for detecting the throttle opening) θ, a primary pulley rotational speed sensor 33 for detecting the rotational speed (primary rotational speed) Np of the primary pulley 5a of the continuously variable transmission 3, and the rotational speed of the secondary pulley 5d (secondary A secondary pulley rotation speed sensor 34 for detecting the rotation speed) Ns, and an upshift switch 35a, a downshift switch 35b, and a D range switch 27 as a shift switch described later are connected.

  Further, a line pressure control solenoid valve 15a and a primary pressure control solenoid valve 15b constituting a shift control actuator 15 for controlling the hydraulic pressure of the continuously variable transmission 3 are connected to the output side of the TCU 21, and A gear position display means 29 is connected.

  The D range switch 27 is disposed in the range operation unit 24 provided in the console box in the vehicle interior, and is turned on when the driver sets the select lever 25 to the drive (D) range. The gear position display means 29 is disposed on a meter panel 28 provided on the driver's seat side. Further, as shown in FIG. 2, the upshift switch 35 a and the downshift switch 35 b are provided on the driver's hand side, such as the steering handle 26.

  In the TCU 21, the shift mode is automatically set to an automatic shift mode (also referred to as a D range mode) and a temporary manual shift mode according to the select position of the select lever 25 and the ON / OFF of the upshift switch 35a and the downshift switch 35b. Switch on.

  The automatic transmission mode is selected by setting the select lever 25 to the drive (D) range and turning on the D range switch 27. The temporary manual shift mode is selected by turning on the upshift switch 35a or the downshift switch 35b with the select lever 25 set to the D range, that is, with the D range switch 27 turned on.

  As shown in FIG. 3A, when the automatic transmission mode is selected, the throttle opening sensor 32 is within a range in which the relationship between the primary rotational speed Np and the vehicle speed V is surrounded by a solid line according to the running state of the vehicle. The gear ratio i (i = Np / Ns) is set so as to be an optimum value determined by the throttle opening θ detected in step (b).

  Also, as shown in FIG. 6B, when the driver turns on the upshift switch 35a or the downshift switch 35b while operating in the automatic shift mode while operating the steering handle 26, the shift mode is set to the temporary manual shift mode. Switch to At this time, a shift stage set when the upshift switch 35a or the downshift switch 35b is turned on is displayed on the meter panel 28 provided on the driver's seat side.

  Next, the hydraulic circuit of the continuously variable transmission 3 will be described. Reference numeral 11 in the drawing denotes an engine-driven or electric oil pump. A discharge port of the oil pump 11 is communicated with a line pressure control valve 13 via a line pressure oil passage 12. Furthermore, the line pressure control valve 13 is a line constituting a secondary hydraulic chamber 5g, a primary pressure control valve 14, and a shift control actuator 15 provided in the secondary pulley 5d of the continuously variable transmission 3 via the line pressure oil passage 12. The pressure control solenoid valve 15a and the primary pressure control solenoid valve 15b are communicated with each other through an orifice 16.

  The line pressure control solenoid valve 15a and the primary pressure control solenoid valve 15b are controlled by a control signal such as a duty ratio from the TCU 21, and are transferred from the line pressure control solenoid valve 15a to the line pressure control valve 13 through the oil passage 17. The line operating pressure is supplied, and the primary operating pressure is supplied from the primary pressure control solenoid valve 15b to the primary pressure control valve 14 via the oil passage 18.

  The line pressure control valve 13 sets the line pressure Ps based on the speed ratio i and the engine torque T by the line operating pressure. Further, the primary pressure control valve 14 is provided in the primary pressure control valve 14 upstream of the primary pressure control valve 14 and the primary pulley 5a of the continuously variable transmission 3 according to the balance between the primary pressure and the line pressure Ps. The primary hydraulic chamber 5f is switched by switching between an oil supply position that connects the oil passage 19 communicating with the primary hydraulic chamber 5f and an oil discharge position that shuts off the oil passages 12 and 19 and drains the oil passage 19. Shift control is performed by controlling the hydraulic pressure supplied to the motor.

  Further, as shown in FIG. 2B, when the temporary manual shift mode is selected, the gear ratio i is a value that is fixed in a stepwise manner as in an ordinary multi-stage transmission (for example, a seventh gear). Fixed gear ratio). When the driver turns on the upshift switch 35a in the automatic transmission mode, the fixed transmission ratio closest to the upshift side is set from the current transmission ratio. When the downshift switch 35b is turned on, the fixed gear ratio closest to the downshift side from the current gear ratio is set. Then, when the upshift switch 35a or downshift switch 35b is further turned on from that state, the driver upshifts from the seven speed ratio characteristics shown in (1) to (7) in FIG. Each time the switch 35a or the downshift switch 35b is turned on, the fixed gear ratio is sequentially upshifted or downshifted. Note that the seven-speed shift shown in FIG. 3B is merely an example, and in addition to the seven-speed shift, a fixed gear ratio corresponding to another multi-speed shift such as a five-speed shift or a six-speed shift may be set. .

  When the driver turns on the upshift switch 35a or the downshift switch 35b to switch to the temporary manual shift mode while traveling in the automatic transmission mode, the TCU 21 turns on the upshift switch 35a or the downshift switch 35b. In accordance with the operation, manual shift control for upshifting or downshifting the fixed gear ratio is performed, and a release condition for returning the shift mode to the automatic shift mode is determined based on a parameter indicating an operation state. When the release condition is satisfied, the shift mode is automatically returned to the automatic shift mode.

  The shift mode switching control and temporary manual shift mode release condition determination processing executed by the TCU 21 are specifically performed according to the flowcharts shown in FIGS.

  FIG. 4 shows a shift mode switching control routine. This routine is executed at predetermined intervals after the engine is started. First, in step S1, it is determined from the output of the D range switch 27 whether or not the select lever 25 is set to the D range. If YES in step S3, the flow advances to step S2. If not in the D range, the routine is exited.

  When it is determined that the select lever 25 is set to the D range and the process proceeds to step S2, the upshift switch 35a or the downshift switch 35b provided on the driver's hand side such as the steering handle 26 is turned on. If either of the shift switches 35a and 35b is turned on, the process proceeds to step S3 to check whether or not the temporary mode determination flag Ftem is cleared, and Ftem = 0 is cleared. If so, the process proceeds to step S5, the normal automatic transmission mode is executed, and the routine is exited. In the automatic transmission mode, the relationship between the primary rotational speed Np and the vehicle speed V is determined by the throttle opening θ detected by the throttle opening sensor 32 within the range surrounded by the solid line in FIG. The speed ratio i (i = Np / Ns) is automatically controlled so as to be an optimum value determined.

Further, when the temporary mode determination flag Ftem is set to Ftem = 1, either of the shift switches 35a and 35b is once turned on at the time of execution of the routine before the previous time, and the temporary manual shift mode is continued. It jumps to step S6. The initial value of the temporary mode determination flag Ftem is 0, which is set in step S4, which will be described later, and cleared in step S21 shown in FIG. 5, while either of the shift switches 35a, 35b is selected in step S2. When turned ON, the process proceeds to step S4, the temporary mode determination flag Ftem is set (Ftem ← 1), and the process proceeds to step S6.

  When the process proceeds from step S3 or S4 to step S6, after executing the temporary manual shift mode, the routine is exited. The temporary manual shift mode executed in step S6 is processed according to the temporary manual shift mode control routine shown in FIG.

  In this routine, first, in step S11, the temporary manual shift mode release condition is referred to. The release condition is, for example, when acceleration / deceleration operation at a predetermined acceleration or lower than deceleration is continued for a certain time or longer, when the accelerator pedal is released for a predetermined time or longer, kick-down acceleration is detected by depressing the accelerator pedal. In some cases, a predetermined time or more has elapsed since the start of the vehicle, or the vehicle speed has become a predetermined vehicle speed or less.

  Subsequently, it progresses to step S12 and the presence or absence of cancellation | release conditions is determined. If all of the release conditions are not satisfied, it is determined that the release conditions are not satisfied, the process proceeds to step S13, manual shift control is executed, and the routine is exited. In the manual shift control, the gear ratio i (i = Np / Ns) based on the primary rotational speed Np and the secondary rotational speed Ns is fixed in a stepwise manner as in an ordinary multi-stage transmission. In the first routine that shifts from the automatic transmission mode to the manual shift control, when the upshift switch 35a is turned on, the fixed transmission ratio closest to the upshift side is set from the current transmission ratio i. When the downshift switch 35b is turned on, the fixed gear ratio closest to the downshift side from the current gear ratio i is set. In the second and subsequent routine executions, the upshift or downshift is sequentially performed each time the upshift switch 35a or the downshift switch 35b is turned on.

  If at least one of the release conditions is satisfied in step S12, it is determined that the release condition is satisfied, and the process proceeds to step S14. In step S14 and subsequent steps, shift control for shifting to the automatic shift mode is executed.

  First, in step S14, the shift speed displayed on the shift speed display means 29 is turned off, and in step S15, the final target engine speed Neo as a final target value for shifting to the automatic shift mode is set.

  The final target engine speed Neo is set based on the throttle opening θ and the vehicle speed V by referring to a shift schedule map (not shown) or by calculation. In this case, instead of the final target engine speed Neo, a final target gear ratio is set, or in a vehicle employing a torque converter as the starting clutch 2, the final target turbine speed of the torque converter is set. Also good.

  Next, the process proceeds to step S16, where the current speed ratio i (i = Np / Ns) is read, and in step S17, the speed ratio change amount Δi for each calculation cycle is set. This gear ratio change amount Δi is obtained when the driver intentionally returns to the automatic transmission mode from the normal manual shift mode, that is, after the manual switch mode (not shown) is turned on to execute the normal manual shift mode, the select lever It is set to a smaller value than the gear ratio change amount set when 25 is returned. Further, the gear ratio change amount Δi is a fixed value in this embodiment, but is a variable value that is set with reference to a map that uses, for example, the engine speed Ne and the throttle opening θ, or is set by calculation. Alternatively, the transmission ratio change amount Δi may be a variable value that is set by referring to the map or by calculation based on the final target engine speed Neo.

  Thereafter, the process proceeds to step S18, the speed ratio change amount Δi is added to the speed ratio i read in step S16 to set the target speed ratio is, and the process proceeds to step S19, where the actual speed ratio i is the target speed ratio is. So that the primary pressure control solenoid valve 15b provided in the shift control actuator 15 is controlled to supply the primary operating pressure to the primary pressure control valve 14 via the oil passage 18. Then, the primary pressure supplied from the primary pressure control valve 14 to the primary hydraulic chamber 5f is controlled, and gear ratio change restriction control is performed so that the gear ratio i converges to the target gear ratio is.

  Next, in step S20, whether or not the absolute value (| Neo−Ne |) of the difference between the final target engine speed Neo and the engine speed Ne detected by the engine speed sensor 31 is within the set range Nes. If | Neo−Ne |> Nes is not satisfied, the process returns to step S15, and the final target engine speed Neo is set again.

  On the other hand, if | Neo−Ne | ≦ Nes and the engine speed Ne falls within the predetermined range (Nes) with respect to the final target engine speed Neo, the process proceeds to step S21, and the temporary mode determination flag Ftem is cleared ( Ftem ← 0), exit the routine.

  At this time, since the gear ratio change amount Δi is set to a smaller value than the gear ratio change amount when the driver intentionally returns to the automatic gear shift mode from the normal manual shift mode, the engine speed Ne. Becomes longer until it converges to the final target engine speed Neo. Since the transition time to the automatic transmission mode is relatively long, the driver can easily recognize that the temporary manual shift mode is canceled and the automatic transmission mode is entered.

  Thereafter, when the shift mode switching control routine shown in FIG. 4 is executed, since Ftem ← 0 in step S3, the process proceeds to step S5, and the automatic shift mode is executed. At that time, since the driver is aware of the shift to the automatic transmission mode, there is no sense of incongruity that the gear ratio has been changed rapidly, and the switching from the temporary manual shift mode to the automatic transmission mode is excellent. Become.

  In addition, since the change in the gear ratio i is gentle when shifting from the temporary manual shift mode to the automatic shift mode, there is no sudden change in the driving force, and the shift can be performed smoothly.

  Further, the range operation unit 24 is operated by operating the up switch or the down switch after tilting the select lever and turning on the manual switch as disclosed in, for example, JP-A-10-318367. In a vehicle equipped with a so-called manual shift mode that shifts or downshifts, the manual switch is turned off when the driver returns the select lever, and the manual shift mode is released. In this case, since the release of the manual shift mode is performed by the driver's intention, the speed ratio change amount set at this time is set to the speed ratio change amount Δi set when the above-described temporary manual shift mode is released. Even if the transition time to the automatic transmission mode is shortened by setting a larger value than this, since the time to transition from the temporary manual shift mode to the automatic transmission mode is relatively gradual, switching can be performed without a sense of incongruity. As a result, when shifting from the manual shift mode to the automatic transmission mode, an acceleration feeling similar to that of the upshift after the kickdown acceleration can be obtained depending on the driver's operation.

  In this embodiment, in steps S16 to S18 of the routine shown in FIG. 5, the target gear ratio is set for each calculation cycle is limited based on the gear ratio change amount Δi. Limiting the amount of change in the normal gear ratio when the driver intentionally returns to the automatic transmission mode from the shift mode with a limiter, gain, etc. The target speed ratio is may be set based on the above.

  6 and 7 show a shift mode switching control routine according to the second embodiment of the present invention. The configuration of the continuously variable transmission 3 according to this embodiment and its peripheral devices is the same as that of the first embodiment. Therefore, the same components are denoted by the same reference numerals as those shown in FIG. Description is omitted.

  In this embodiment, when kick-down acceleration is set as a release condition for the temporary manual shift mode, when releasing the temporary manual shift mode, after performing a downshift once, the same release operation as in the first embodiment is performed. It is a thing.

  First, in step S31, the temporary manual shift mode release condition is referred to. As for the release condition, in addition to the release condition described in the first embodiment, the presence or absence of kickdown acceleration is determined. The presence or absence of kickdown acceleration is determined from, for example, a change in the throttle opening θ (or accelerator pedal), and if the amount of change in the throttle opening θ (or accelerator pedal) per unit time is large, the kick Judge as down acceleration.

  In step S32, it is determined whether a release condition is satisfied. If all of the set release conditions are not satisfied, it is determined that the release conditions are not satisfied, the process proceeds to step S33, manual shift control is executed, and the routine is exited. Since this manual shift control is the same as step S13 shown in FIG. 5 of the first embodiment, description thereof is omitted.

  If at least one of the release conditions is satisfied in step S32, the process proceeds to step S34, and shift control for shifting to the automatic shift mode is executed in step S34 and subsequent steps.

  First, in step S34, the gear stage displayed on the gear stage display means 29 is turned off, and in step S35, it is checked whether or not the determination condition for establishing the release condition includes kickdown acceleration. If not, the process proceeds to step S36. If not included, the process jumps to step S37. In step S36, the gear position A is set to a value obtained by downshifting the current gear position A by one gear (A ← A-1). Next, the primary pressure provided in the shift control actuator 15 is set so that the gear ratio i corresponding to the downshifted gear stage A is set as the target gear ratio is and the actual gear ratio i converges to the target gear ratio is. The control solenoid valve 15b is controlled to control the primary pressure supplied to the primary hydraulic chamber 5f of the primary pulley 5a.

  Then, the process proceeds from step S35 or S36 to step S37. Steps S37 to S43 correspond to steps S15 to S21 shown in FIG.

  As described above, in this embodiment, when kickdown acceleration is applied as a release condition for the temporary manual shift mode and the release condition is satisfied due to the kickdown acceleration, when the temporary manual shift mode is released, Is shifted down by one step, and then the release operation similar to that of the first embodiment is performed, so that in addition to the effect of the first embodiment, an acceleration feeling of kick-down acceleration can be obtained. In addition, after the kickdown acceleration, the change in the gear ratio i is moderate when shifting from the temporary manual shift mode to the automatic transmission mode, so that a stronger acceleration feeling can be obtained. In step S36, the gear is downshifted by one step, but may be a plurality of steps, or may be a variable value set based on the gear ratio and the vehicle speed at the time of kickdown determination.

  FIG. 8 shows a shift mode switching control routine according to the third embodiment of the present invention. The configuration of the continuously variable transmission 3 according to this embodiment and its peripheral devices is the same as that of the first embodiment. Therefore, the same components are denoted by the same reference numerals as those shown in FIG. Description is omitted.

  In this embodiment, when the temporary manual shift mode is released, the gear ratio i is temporarily shifted to the overdrive side at a constant rate, so that the temporary manual shift mode is automatically released due to insufficient driving force for the driver. It is made to recognize that it shifts to shift mode.

  Steps S51 to S53 of this routine are the same as steps S11 to S13 shown in FIG. 5 of the first embodiment. In step S52, it is determined that the temporary manual shift mode release condition is satisfied, and the process proceeds to step S54. The current shift speed A is read, and in step S55, the shift speed Am when release is established is updated with the read speed shift A (Am ← A).

  Next, the process proceeds to step S56, and the gear stage displayed on the gear stage display means 29 is turned off as in step S14 shown in FIG. 5 of the first embodiment, and the current gear ratio i is read in step S57. Then, the process proceeds to step S58, where the target speed ratio is is set by subtracting the speed ratio change amount Δio as a preset change amount from the speed ratio i read in step S57 (is ← i−). Δio).

  Thereafter, the process proceeds to step S59 where the primary pressure control solenoid valve 15b provided in the shift control actuator 15 is controlled so that the actual speed ratio i converges to the target speed ratio is, and the primary hydraulic pressure of the primary pulley 5a is controlled. The primary pressure supplied to the chamber 5f is controlled. Then, control for shifting the gear ratio i to the target gear ratio is, that is, control for gradually shifting to the overdrive side is performed.

  Next, the process proceeds to step S60, the count value C of the timer counter that measures the elapsed time is incremented (C ← C + 1), and the process proceeds to step S61, whether or not the count value C has reached the set value Co corresponding to the set time. If C <Co, it has not been reached, so the process returns to step S57. When the set time of C = Co has been reached, that is, when the gear ratio i has shifted to the overdrive side in a predetermined manner, the process proceeds to step S62.

  Thus, when releasing the temporary manual shift mode, first, the gear ratio i is shifted to the overdrive side at a constant rate, so that the driver feels a slight lack of driving force. It can be recognized that the temporary manual shift mode is canceled and the shift to the automatic transmission mode is made due to insufficient power.

  The gear ratio change amount Δio and the set value Co corresponding to the set time may be fixed values, or may be variable values set based on the gear ratio i or the vehicle speed V when the release condition is satisfied. In this case, the gear ratio change amount Δio and the set value Co are set in accordance with values that make the driver feel deficient in driving force and minimize the change in vehicle behavior.

  In step S62, the speed ratio i corresponding to the release established speed Am stored in step S55 is set as the target speed ratio is, and the process proceeds to step S63, where the actual speed ratio i converges to the target speed ratio is. Thus, the primary pressure supplied to the primary hydraulic chamber 5f of the primary pulley 5a is controlled.

  Thereafter, the final target engine speed Neo for shifting to the automatic transmission mode is set. These controls are performed in steps S37 to S43 shown in FIG. 7 of the second embodiment (or shown in FIG. 5 of the first embodiment). Since this is the same as steps S15 to S21), the description is omitted.

  As described above, in the present embodiment, when the temporary manual shift mode is canceled, the gear ratio i is first shifted to the overdrive side. Therefore, the shift to the automatic shift mode is performed as compared with the first mode. It can be recognized more reliably.

Schematic configuration diagram of a continuously variable transmission according to the first embodiment Same perspective view of steering handle and meter panel around driver's seat (A) is a shift characteristic diagram showing the relationship between the rotation speed of the primary pulley of the continuously variable transmission and the vehicle speed in the automatic transmission mode, and (b) is a similar shift characteristic diagram in the manual shift mode and the temporary manual shift mode. Same as above, a flowchart showing a shift mode switching control routine The flowchart showing the temporary manual shift mode control routine Flowchart showing a temporary manual shift mode control routine according to the second embodiment (part 1) Flowchart showing the temporary manual shift mode control routine (part 2) The flowchart which shows the temporary manual shift mode control routine by 3rd form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine, 3 ... Continuously variable transmission, 5a ... Primary pulley, 5d ... Secondary pulley, 5f ... Primary hydraulic chamber, 5g ... Secondary hydraulic chamber, 15 ... Transmission control actuator, 21 ... Transmission control unit (TCU), 24 ... Range operation section 29. Shift stage display means 35a. Upshift switch 35b Downshift switch .DELTA.i Speed change ratio .DELTA.io Speed change ratio .theta. Throttle opening A A Speed stage Am ... shift stage when release is established, Ftem ... temporary mode determination flag, Ne ... engine speed, Neo ... final target engine speed, Nes ... set range, Np ... primary speed, Ns ... secondary speed, Ps ... line pressure, T ... engine torque, V ... vehicle speed, i ... speed ratio, is ... target speed ratio

Agent Patent Attorney Susumu Ito

Claims (5)

An automatic transmission mode that automatically sets the transmission ratio of the continuously variable transmission based on the driving state, and a temporary manual shift mode that allows a plurality of preset transmission ratios to be selected during operation of the automatic transmission mode by operating a shift switch. A mode-specific transmission control means comprising:
Cancellation condition determination means for determining the cancellation condition of the temporary manual shift mode according to the driving state;
When the release condition is satisfied, a final target value of the gear ratio is set based on the driving state, and the gear ratio is changed at a gear ratio change amount for each calculation cycle so as to converge to the final target value. In a transmission control device for a continuously variable transmission comprising a limiting means,
In the gear ratio change limiting means, the gear ratio change amount is set to a value smaller than a value when returning from the manual shift mode to the automatic gear shift mode by manual operation, and a time for the gear ratio to converge to the final target gear ratio is set. A speed change control device for a continuously variable transmission characterized in that it is lengthened. 2. The speed change control device for a continuously variable transmission according to claim 1, wherein the speed ratio change amount is set based on a rotation speed and a throttle opening of a primary pulley provided in the continuously variable transmission. . The shift control means for each mode is provided with a manual shift mode for selecting a plurality of preset fixed gear ratios by switching from the automatic shift mode.
The speed ratio change limiting means limits the speed ratio change amount that is set when the release condition is satisfied, and the normal speed ratio change amount that is set when the manual shift mode is returned to the automatic speed change mode. The transmission control device for a continuously variable transmission according to claim 1, wherein the transmission control device is set as follows. The release condition determining means has a kickdown acceleration by depressing an accelerator pedal as a release condition for the temporary manual shift mode.
4. In the temporary manual shift mode, when the release condition determining means determines that the release condition is satisfied by detecting the kickdown acceleration, the fixed gear ratio is first downshifted. A transmission control device for a continuously variable transmission according to any one of the above. In the temporary manual shift mode, when the release condition determining means determines that the release condition is satisfied, the speed ratio is first shifted from the current fixed speed ratio to the overdrive side by a set change amount. Item 5. A transmission control device for a continuously variable transmission according to any one of Items 1 to 4.

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