JP4624028B2 - Control device for continuously variable transmission - Google Patents

Description

  The present invention relates to a control device for a continuously variable transmission, and more particularly to a technique for ensuring power performance in response to an acceleration request.

  As a continuously variable transmission used for a vehicle such as an automobile, there are a belt type and a toroidal type. A belt-type continuously variable transmission has an input-side primary pulley provided on an input shaft, an output-side secondary pulley provided on an output shaft, and a power transmission element such as a belt or a chain spanned between these pulleys. Then, by changing the groove width of each pulley and changing the winding diameter of the power transmission element, the transmission ratio is changed steplessly, and the rotation of the input shaft is controlled to be transmitted to the output shaft and transmitted. can do.

  Such a speed change control device for a continuously variable transmission has a memory in which a steady speed change characteristic map is stored, and refers to the steady speed change characteristic map based on parameters indicating operating conditions such as throttle opening and vehicle speed. Thus, the target rotational speed of the primary pulley is set, and the follow-up control is performed so that the actual primary pulley rotational speed converges on the target rotational speed. For example, when the accelerator pedal is depressed slowly to accelerate the vehicle speed, the target rotational speed of the primary pulley is controlled so that the target gear ratio corresponding to the throttle opening, that is, the gear shift line is obtained. Here, the throttle opening may be realized by replacing at least one of the accelerator pedal opening, the intake air amount, and the intake pipe pressure.

  On the other hand, as a control method for the transmission ratio of the continuously variable transmission when the driver depresses the accelerator pedal quickly and rapidly in order to accelerate the vehicle rapidly, the transmission ratio is gradually reduced after setting the transmission ratio to the maximum value. There is a method of controlling so that the gear ratio is gradually reduced when the engine speed increases to some extent. Further, as described in Patent Document 1, when rapid acceleration is required, the gear ratio is changed stepwise so as to increase the vehicle speed while repeating the gradual increase and decrease of the engine speed, and the engine speed There is a control system in which the minimum number of revolutions when the vehicle is decelerated is set higher as the vehicle speed increases.

Further, when it is determined that the driver has stepped on the accelerator pedal to request rapid acceleration, the speed ratio is fixed and the engine speed is increased after reaching the predetermined upper limit speed. There has been proposed a control method in which the rotation speed reduction control for reducing the rotation speed, that is, the upshift control is repeated, and the amount of decrease in the engine rotation speed is changed in accordance with the vehicle speed and the accelerator opening.
JP-A-5-332426

  However, it is not possible to ensure power performance according to the degree of acceleration requested by depressing the accelerator pedal only by changing the gear ratio stepwise when sudden acceleration is required as in the prior art. In particular, when a large acceleration request is required when a heavy load is applied to the vehicle, for example, when traveling on an uphill, the driving force is insufficient with the conventional control method, and acceleration is continued. There is a problem that can not be.

  It is an object of the present invention to ensure power performance in response to acceleration requests.

A control device for a continuously variable transmission according to the present invention includes an input-side rotator driven by an engine and an output-side rotator driven by a power transmission element by the input-side rotator and continuously changing a gear ratio. comprising a continuously variable transmission for changing the acceleration request detecting means for detecting an acceleration request of the driver, a vehicle speed detecting means for detecting a vehicle speed, and a load calculating means for calculating the amount of running resistance and the external load of the vehicle the control device for a continuously variable transmission has, previous SL accelerate request to set the transmission mode to the variable transmission mode when the above first setting value, the acceleration request is more larger second set value than the first set value Shift mode switching determining means for setting the shift mode to the driving force priority mode, and when the step shift mode is set, the throttle opening, the accelerator pedal opening, the intake air amount, and the intake pipe pressure At least A rotation speed range setting means for setting the upper limit rotation speed and lower limit rotation speed of the input side rotating member rotation speed in accordance with the one with the vehicle speed, when the phase shift mode is set, the input-side rotary member When the rotational speed reaches the upper limit rotational speed, the transmission gear ratio is changed so as to be the lower limit rotational speed, and when the driving force priority mode is set, the input side rotational body rotational speed is set to the upper limit rotational speed. Shift control means for changing the gear ratio toward the highest maximum shift line .

Control device for a continuously variable transmission of the present invention, the is a load amount calculated by the load calculating means is equal to or higher than a predetermined value, if there is either One acceleration request, the upper limit rotational speed after reaching the upper limit rotational speed It is characterized in that the transmission ratio is maintained.

Control device for a continuously variable transmission of the present invention, the variable transmission mode, said the upper limit rotational speed after reaching the upper limit rotational speed is maintained to prohibit to stepwise shift to the lower limit rotational speed Features.

The control device for a continuously variable transmission according to the present invention maintains the step shift mode when a deceleration request is made by an engine brake during the step shift mode, and decelerates while maintaining the speed ratio until the lower limit rotational speed is reached. It is characterized by that.

  The control device for a continuously variable transmission according to the present invention is characterized in that the upper limit rotational speed and the lower limit rotational speed are increased when the load amount tends to increase during traveling.

  The control device for a continuously variable transmission according to the present invention is characterized in that the upper limit rotational speed and the lower limit rotational speed are decreased when the load amount tends to decrease.

  The control device for a continuously variable transmission according to the present invention is characterized in that the gear ratio is increased when the load amount tends to increase.

  The control device for a continuously variable transmission according to the present invention is characterized in that the speed ratio is increased when the road surface gradient is a downward gradient and no acceleration request is detected.

The control device for a continuously variable transmission according to the present invention is characterized in that when the road surface gradient is a downward gradient, the lower limit rotational speed is increased in accordance with a load amount.

  The control device for a continuously variable transmission according to the present invention has lateral G detection means for detecting acceleration applied to the vehicle in the vehicle width direction, and the shift mode switching determination means is the lateral G detected by the lateral G detection means. The shift mode is switched to the step shift mode when the magnitude of the absolute value becomes a predetermined value or more.

A control device for a continuously variable transmission according to the present invention has an input-side rotator driven by an engine and an output-side rotator driven by a power transmission element by the input-side rotator and continuously changes the gear ratio. A continuously variable transmission to be changed, a lateral G detecting means for detecting an acceleration applied to the vehicle in the vehicle width direction, a vehicle speed detecting means for detecting a vehicle speed, and a load calculating means for calculating a running resistance of the vehicle and an external load amount Shift mode switching determining means for switching between a continuously variable transmission mode that changes the transmission ratio steplessly according to the lateral G and a stepped transmission mode that changes the transmission ratio stepwise, and the throttle opening in the stepped transmission mode A rotation speed range for setting an upper limit rotation speed and a lower limit rotation speed of the input side rotation body according to at least one of the accelerator pedal opening, the intake air amount, and the suction pipe pressure and the vehicle speed. Setting means, and shift control means for controlling stepwise between the upper limit speed and the lower limit speed set by the speed range setting means in the step shift mode to a speed ratio determined according to the vehicle speed. In the continuously variable transmission control apparatus, the shift mode switching determination means sets the shift mode to a step shift mode when the magnitude of the absolute value of the lateral G detected by the lateral G detection means is a predetermined value or more. together with the shift control means is characterized in that the input side rotating body speed that the speed ratio is varied so that the lower limit engine speed reaches the maximum rotation speed.

  The control device for a continuously variable transmission according to the present invention is characterized in that when the lateral G absolute value increases, the upper limit rotational speed and the lower limit rotational speed are increased.

  When the lateral G absolute value is equal to or greater than a predetermined value, the continuously variable transmission control device according to the present invention calculates the upper limit rotational speed while holding a peak value of an accelerator opening value that sets the upper limit rotational speed. It is characterized by.

Control device for a continuously variable transmission of the present invention, the lateral G absolute value is at the predetermined value or more, the to maintain the upper limit rotational speed after reaching the upper limit rotational speed, a stepping manner shifting to the lower limit rotational speed It is characterized by prohibiting.

  According to the present invention, the vehicle can be driven at the highest possible engine speed in response to the acceleration request, so that power performance can be ensured. Since the gear ratio does not fluctuate due to the accelerator operation in the step shifting mode, it is easier to adjust the vehicle speed and to drive the vehicle with high horsepower when acceleration demand is high by using even higher engine speeds. Can be made.

  When the load amount is equal to or greater than the predetermined value and there is a further acceleration request, the speed ratio that corresponds to the lower limit speed set by the throttle opening is obtained by setting the speed ratio to maintain the upper limit speed. It is possible to prevent the rotational speed from decreasing and the driving force from becoming insufficient, and it is possible to continue acceleration while maintaining a high driving force continuously. In addition, when the load is heavy, such as when traveling on an uphill, the lower limit rotational speed is suddenly stepped, that is, an unnecessary upshift occurs, resulting in sudden lack of driving force and poor traveling performance. Can be prevented.

  When the load amount tends to increase, by increasing the upper and lower rotation speeds, a higher torque can be maintained even at the same vehicle speed than when the gear ratio is simply changed by the vehicle speed.

  When the load amount tends to decrease, by reducing the upper and lower speeds, the driving feeling is improved by using a lower engine speed during driving that requires less driving force when accelerating. And the deterioration of fuel consumption can be prevented.

  When the load amount tends to increase, the drive torque of the drive wheels can be increased by increasing the gear ratio, and a sufficient drive force can be obtained.

  When the road surface gradient tends to descend, sufficient engine braking can be obtained by increasing the gear ratio.

  If the step shifting mode is maintained during sports driving represented by cornering driving, the gear ratio is fixed at a constant vehicle speed, and the gear ratio according to the accelerator operation does not increase or decrease. It is easy to carry out the running. In addition, the acceleration and deceleration feeling of the vehicle with respect to the accelerator operation becomes one-to-one, a linear feeling and a direct feeling are obtained, an operational feeling like a manual transmission is obtained, and a running feeling is improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a drive system of a vehicle equipped with a belt-type continuously variable transmission as an example of an automatic transmission. In this continuously variable transmission, the torque of a crankshaft 2 of an engine 1 serves as a fluid transmission mechanism. A drive-side primary shaft 5 transmitted via the converter 3 and the forward / reverse switching device 4 and a driven-side secondary shaft 6 parallel to the drive-side primary shaft 5 are provided.

  The primary shaft 5 is provided with a primary pulley 7 as an input side rotating body. The primary pulley 7 is a fixed pulley 7a integrated with the primary shaft 5, and a ball spline or the like on the primary shaft 5 opposite thereto. The movable pulley 7b is mounted so as to be slidable in the axial direction, and the cone surface interval of the pulley, that is, the pulley groove width is variable. The secondary shaft 6 is provided with a secondary pulley 8 as an output-side rotating body. The secondary pulley 8 is a fixed pulley 8 a integrated with the secondary shaft 6, and a movable pulley 7 b on the secondary shaft 6 facing this. And a movable pulley 8b that is slidably mounted in the axial direction, and the pulley groove width is variable.

  A belt 9 as a power transmission element is stretched between the primary pulley 7 and the secondary pulley 8, and the ratio of the winding diameter of the belt 9 to each pulley is changed by changing the groove width of both pulleys 7 and 8. Is changed, the rotation of the primary shaft 5 is steplessly changed and transmitted to the secondary shaft 6. If the winding diameter of the drive belt 9 around the primary pulley 7 is Rp and the winding diameter around the secondary pulley 8 is Rs, the gear ratio, i.e., the pulley ratio i is i = Rs / Rp.

  The rotation of the secondary shaft 6 is transmitted to the drive wheels 11a and 11b via a gear train having a reduction gear and a differential device 10. In the case of front wheel drive, the drive wheels 11a and 11b are front wheels.

  In order to change the groove width of the primary pulley 7, a plunger 12 is fixed to the primary shaft 5, and a primary cylinder 13 slidably contacting the outer peripheral surface of the plunger 12 is fixed to the movable pulley 7b. A driving oil chamber 14 is formed by the primary cylinder 13 and the primary cylinder 13. On the other hand, in order to change the groove width of the secondary pulley 8, a plunger 15 is fixed to the secondary shaft 6, and a secondary cylinder 16 slidably contacting the outer peripheral surface of the plunger 15 is fixed to the movable pulley 8b. The plunger 15 and the secondary cylinder 16 form a drive oil chamber 17. Each groove width is set by adjusting the primary pressure Pp introduced into the primary side drive oil chamber 14 and the secondary pressure Ps introduced into the secondary side drive oil chamber 17.

  The torque converter 3 has a pump-side shell 18 as an input element connected to the crankshaft 2 and a turbine runner 20 as an output element connected to the torque converter output shaft 19. A lockup clutch 22 that engages with a front cover 21 fixed to the side shell 18 is attached.

  FIG. 2 is a schematic diagram showing a speed change control device for a continuously variable transmission. The drive oil chambers 14 and 17 are supplied with hydraulic oil in an oil pan by an oil pump 23 driven by an engine or an electric motor. It has become. The secondary pressure path 24 connected to the discharge port of the oil pump 23 is communicated with the drive oil chamber 17 and is communicated with the secondary pressure port of the secondary pressure regulating valve 25. The secondary pressure Ps supplied to the drive oil chamber 17 by the secondary pressure adjusting valve 25 is adjusted to a pressure commensurate with the transmission capacity required for the belt 9.

  The secondary pressure passage 24 is connected to the secondary pressure port of the primary pressure adjustment valve 26 via a communication oil passage 27, and the primary pressure port of the primary pressure adjustment valve 26 is connected to the primary side drive oil chamber via the primary pressure passage 28. 14. The primary pressure adjusting valve 26 adjusts the primary pressure Pp to a value corresponding to the target gear ratio, the vehicle speed, etc., and the groove width of the primary pulley 7 is changed to control the gear ratio. The secondary pressure adjustment valve 25 and the primary pressure adjustment valve 26 are proportional solenoid valves, respectively, and the secondary pressure Ps and the primary pressure are controlled by controlling the current values supplied from the transmission control unit 30 to the solenoid coils 25a and 26a. Pp is adjusted.

  The transmission control unit 30 has a primary pulley rotation speed sensor 31 as an input side rotation speed detection means for detecting the rotation speed of the primary pulley 7 and a detection from a secondary pulley rotation speed sensor 32 for detecting the rotation speed of the secondary pulley 8. A signal is input. The engine speed sensor 33 as an engine speed detection means, a throttle opening sensor 34 for detecting the opening of the throttle valve, a vehicle speed sensor 35 for detecting the traveling speed of the vehicle, and a control lever operated by the driver are selected. Detection signals from a range detection sensor 36 that detects the travel range and an accelerator opening sensor 37 that detects depression of the accelerator pedal are input to the transmission control unit 30. Further, detection signals from a lateral G sensor 38 that detects lateral acceleration applied to the vehicle when the vehicle turns, a steering angle sensor 39 that detects the steering angle of the front wheels when the vehicle turns, and a tilt angle sensor 40 that detects the road surface gradient. Is input to the transmission control unit 30. The two sensors 38 and 39 both constitute a lateral G detecting means for detecting a lateral acceleration applied to the vehicle when the vehicle is turning, and the lateral G may be detected by either one of them. The lateral G may be detected by a wheel speed sensor that detects the wheel speed of the four wheels. The inclination angle sensor 40 is used to detect a road surface gradient and calculate a load applied to the vehicle. In order to calculate a road surface gradient and a load, engine torque, auxiliary torque, and loss torque between the engine and driving wheels are used. Alternatively, it may be obtained by calculation using the generated driving force of the vehicle obtained using the efficiency, the gear ratio, and the gear ratio, the rolling resistance, the air resistance, and the acceleration resistance of the vehicle.

  The transmission control unit 30 includes a microprocessor CPU that calculates control signals for the solenoid coils 25a and 26a based on signals from the respective sensors, control data such as tables, maps, and arithmetic expressions, and control programs. ROM, a RAM for temporarily storing data, an input / output port, and the like.

  The speed change control device according to the present invention has a steady speed change mode set when the driver requests gentle acceleration, a step speed change mode set when the driver requests sudden acceleration, and the accelerator pedal is almost fully open. And a driving force priority mode for increasing the upper limit rotational speed of the engine when the engine is fully depressed. The steady transmission mode and the driving force priority mode are continuously variable transmission modes that change the transmission ratio steplessly, whereas the stepped transmission mode has a plurality of shift stages like a stepped automatic transmission. This is a shift mode. The driving force priority mode is set via the step shifting mode, and the driving force priority mode is set to the steady shifting mode via the step shifting mode. The shift mode is switched to the step shift mode when the acceleration request becomes greater than or equal to a predetermined value due to depression of the accelerator pedal, and when the lateral G size exceeds the predetermined value. When traveling is repeated, the step shift mode is set.

  The transmission control unit 30 includes a load calculation unit 41 that calculates a vehicle running load from actual engine torque based on detection signals from the engine speed sensor 33 and the throttle opening sensor 34, and the three modes described above. A shift mode switching determination unit 42 for setting any mode, a rotation speed range setting unit 43 for setting a rotation speed range, and a shift control unit 44 for controlling a gear ratio are provided. However, for convenience, the functional configuration provided in the transmission control unit 30 is shown as a block. The travel load may be calculated by detecting the road surface gradient by the inclination angle sensor 40 and calculating the load applied to the vehicle. Also, the engine torque, the auxiliary machine torque, the loss torque and efficiency between the engine and driving wheels, the speed change, It may be obtained by calculation using the generated driving force of the vehicle obtained by using the ratio and the gear ratio, rolling resistance, air resistance, and acceleration resistance of the vehicle.

  FIG. 3 is a shift control characteristic diagram showing the relationship between the target rotational speed Np of the primary pulley 7 and the vehicle speed V in the continuously variable transmission shown in FIGS. 1 and 2. In FIG. 3, the line passing through the points A and B shows the characteristic line of the low RL where the transmission ratio is the maximum transmission ratio, and the line connecting the points C and D of the overdrive RO where the transmission ratio is the minimum transmission ratio. A characteristic line is shown. A line connecting the B point and the E point indicates a maximum shift line when the accelerator opening is fully open, and a line connecting the A point and the C point indicates a minimum shift line. Further, in FIG. 3, a plurality of thin solid lines between the maximum speed ratio between the points AB and the minimum speed ratio between the points CD are characteristics indicating the relationship between the target rotational speed and the vehicle speed when the speed ratio is constant. A plurality of shift lines indicated by a broken line between a maximum shift line between points BE and a minimum shift line between points AC are shift characteristic diagrams corresponding to the steady shift mode, each of which is a predetermined shift line. The relationship between the vehicle speed V corresponding to the throttle opening and the target rotational speed Np of the primary pulley 7 is shown. Here, the shift characteristic diagram may be set by replacing at least one of the accelerator pedal opening, the intake air amount, and the intake pipe pressure instead of the throttle opening.

  When the vehicle is traveling, the gear ratio is set within the range indicated by the thick line in FIG. 3 according to the traveling state. In the steady transmission mode, for example, the accelerator pedal is set by the driver so that the throttle opening indicated by TH1 in FIG. Is depressed, the transmission ratio is controlled by the transmission characteristic indicated by the transmission line passing therethrough. This steady shift mode is set when the accelerator pedal is depressed slowly, that is, when sudden acceleration is not required, and is set not only during low speed and medium speed but also during high speed cruise. Map data corresponding to the mode is stored in a memory such as a ROM in the transmission control unit 30.

  On the other hand, for example, when the driver depresses the accelerator pedal quickly and reaches the throttle opening indicated by TH2 under the vehicle speed indicated by point F and the target rotational speed Np, Switch to step shifting mode. In this mode, first, the gear ratio is downshifted until the target rotational speed Np reaches the initial rotational speed Npin indicated by the point G, and then the target rotational speed between the upper limit rotational speed NPH and the lower limit rotational speed NPL according to the throttle opening. The vehicle is accelerated while gradually increasing and decreasing the rotational speed. The upper limit speed NPH and the lower limit speed NPL may be set by at least one of the accelerator pedal opening, the intake air amount, and the intake pipe pressure instead of the throttle opening. In addition, driving information such as a gentle depression or sudden depression of the accelerator pedal may be substituted for these signals. When the target rotational speed is gradually increased, the gear ratio is kept constant, and when the target rotational speed is suddenly decreased, an upshift is performed. For example, as shown in FIG. 3, the gear ratio is fixed from point G and the target speed is increased at a constant speed ratio, and the speed ratio is increased when the target speed Np reaches the upper limit speed NPH at point H. The target rotational speed Np is rapidly decreased to the lower limit rotational speed NPL indicated by point I by shifting. Next, the target speed Np is increased to the upper limit speed NPH indicated by the point J with the speed ratio kept constant, and the speed change control is performed at points K to M in FIG. 3 until the vehicle speed corresponds to the accelerator opening. As described above, in the step shift mode, the vehicle is accelerated by repeating acceleration with a constant gear ratio and a rapid decrease in the target rotational speed Np. However, in order to suppress an unnecessary increase in engine speed, the gear ratio is gradually up-shifted according to the vehicle speed in the step shift mode, and the vehicle speed reaching the upper limit speed NPH is adjusted to a higher vehicle speed position (H '). You may do it. In order to suppress the shock caused by the sudden decrease in the target rotational speed Np, when the speed is reduced to the lower limit rotational speed NPL, the target rotational speed Np is limited to the amount of change over time to reach I ′, so that sudden reduction is avoided. good.

  When the accelerator pedal is returned under this step shift mode and when the brake is depressed simultaneously with the return of the accelerator pedal, the target rotational speed Np is reduced while maintaining the step shift mode without switching to the steady shift mode. . For example, when the accelerator pedal is returned under the state of point L in FIG. 3, a gear shifting operation is performed from K to I along the lower limit rotational speed NPL. As a result, during the step shift, a moderate engine brake can be applied even during deceleration, and the running feeling can be improved.

  On the other hand, when the accelerator pedal is fully depressed or nearly fully opened, the driving force priority mode is set after first switching to the step shift mode. For example, when the driver depresses the accelerator pedal rapidly until the throttle opening indicated by TH3 is fully opened under the vehicle speed indicated by point F and the target rotation speed, the maximum speed remains constant while passing through point H. The target rotational speed Np is increased to the point P reaching the speed change line. It may be detected by a kick-down switch that the accelerator pedal is fully depressed or nearly fully opened. For the step shift mode and the driving force priority mode, map data corresponding to each mode is stored in a memory such as a ROM in the transmission control unit 30. Similarly to the above, in order to suppress unnecessary increase in engine rotation, it may be adjusted so as to reach the P ′ point by upshifting according to the vehicle speed.

  The three types of modes described above are determined by the shift mode switching determination unit 42 based on detection signals from the throttle opening sensor 34 and the like, and control signals are sent from the transmission control unit 30 to the solenoid coils 25a and 26a. A control signal is sent to an electronic control throttle for adjusting the engine speed, and the engine speed is automatically set. At this time, instead of the throttle opening sensor signal, at least one of the accelerator pedal opening, the intake air amount, and the intake pipe pressure signal may be substituted.

  The travel load during vehicle travel is calculated by calculating the detection signal from the tilt angle sensor 40 and the actual engine torque, and when the load amount is equal to or greater than a predetermined value and acceleration is requested, the step shift mode When the target rotational speed Np reaches the upper limit rotational speed NPH, the target rotational speed is maintained at the upper limit rotational speed NPH without being rapidly reduced stepwise. For example, if the load amount is equal to or higher than a predetermined value and the acceleration request is continued when the upper limit rotational speed NPH indicated by point H in FIG. The number Np is maintained, and the target rotational speed Np is rapidly reduced stepwise as indicated by a broken line when the load amount becomes a predetermined value or less. As described above, when the upper limit rotational speed NPH is maintained, the target rotational speed Np can be suddenly decreased stepwise toward the lower limit rotational speed NPL using the speed ratio at the upper limit rotational speed NPH as the upper speed ratio. Since it is prohibited, the gear ratio is controlled so that when the vehicle decelerates, the speed ratio is changed to the speed ratio determined according to the vehicle speed toward the lower limit rotational speed NPL.

  As described above, when the load amount is equal to or greater than the predetermined value and there is an acceleration request, if the gear ratio is controlled so as to maintain the upper limit rotation speed NPH, a stepwise sudden decrease is not made. It becomes possible to prevent the engine speed from decreasing and drive power from becoming insufficient due to the gear ratio corresponding to the set lower limit speed NPL, and to continue acceleration while maintaining a high drive power continuously. In addition, when the load is large, such as uphill, suddenly suddenly decreases to the lower limit rotation speed NPL, that is, unnecessary upshift control is prohibited. Is prevented and the running performance is improved. Here, the throttle opening may be substituted with at least one of the accelerator pedal opening, the intake air amount, and the intake pipe pressure.

  Further, in the step shift mode, for example, in FIG. 3, at points I, K, and M, the lower limit rotational speed NPL is rapidly decreased and reached, but after reaching each, the speed ratio that maintains the lower limit rotational speed NPL is set as the lower limit speed ratio. The vehicle is accelerated according to the vehicle speed toward the upper limit rotation speed NPH while maintaining the gear ratio.

  FIG. 4A is a characteristic diagram showing the relationship between the upper limit rotational speed NPH and the vehicle speed when the accelerator pedal is depressed and the throttle opening changes in accordance with the traveling load of the vehicle, and FIG. Similarly, FIG. 4C is a characteristic diagram showing the relationship between the lower limit rotational speed NPL and the vehicle speed when a load is applied, and FIG. 4C is a graph when the upper limit rotational speed NPH and the lower limit rotational speed NPL are changed in this way. FIG. 6 is a characteristic diagram showing a relationship between a target rotational speed Np and a vehicle speed in the step shift mode. Here, these shift maps based on the throttle opening may be substituted by at least one of the accelerator pedal opening, the intake air amount, and the intake pipe pressure.

  As shown in FIG. 4, both the upper limit rotational speed NPH and the lower limit rotational speed NPL are increased when the throttle opening is increasing, and both are decreased when the throttle opening is decreasing. For example, acceleration control is performed from point Q to point R when the throttle opening is 80%, and acceleration control is performed from point S to point T when the throttle opening is 40%. At this time, the load applied to the vehicle that can be detected by the inclination angle sensor or the like is controlled so as to correct both NPH and NPL in FIGS. 4A and 4B in the increasing direction.

  When the lateral G absolute value detected by the lateral G sensor 38 is not less than a predetermined value as well as an increase in the load applied to the vehicle, both the upper limit rotational speed NPH and the lower limit rotational speed NPL shown in FIG. During intense sports driving, the driving force can be increased at a higher rotational speed. When the lateral G absolute value is equal to or greater than the predetermined value, the upper limit rotational speed NPH is maintained as in the case where the load amount is equal to or greater than the predetermined value. Since the target speed Np is suddenly decreased stepwise toward the lower limit speed NPL with the upper speed ratio as the upper speed change ratio, when the vehicle turns, the speed is suddenly decreased and driven. The lack of power is prevented. Also, when the lateral G absolute value becomes greater than or equal to the predetermined value during the step shift mode, the speed ratio that maintains the lower limit speed NPL after reaching the lower limit speed NPL is reduced to the lower limit speed ratio. While maintaining, the vehicle is accelerated according to the vehicle speed toward the upper limit rotation speed NPH. As a result, the lower limit rotational speed increases when the lateral G absolute value increases, so that the vehicle can travel while maintaining a high rotational speed, and when the vehicle speed increases, the lower rotational speed is moved away from the lower limit rotational speed to the upper limit rotational speed. Thus, a transition is made at the speed ratio obtained.

  Further, when the lateral G absolute value becomes greater than or equal to a predetermined value during the step shift mode, the upper limit engine speed is calculated while holding the peak value of the accelerator opening value for setting the upper engine speed. An unnecessarily upshift is prevented when the engine is restored, and an engine brake that is large enough for sports driving can be obtained.

  Further, in the step shifting mode, when the inclination angle sensor 40 detects that the road surface gradient is a downward gradient and no acceleration request is detected, the shift control is performed so as to increase the gear ratio. Furthermore, when the road surface gradient is a downward gradient, the lower limit rotational speed is controlled so as to increase in accordance with the load, and a larger engine brake can be obtained by coasting on a downhill.

  FIG. 5 is a flowchart showing a main routine of the shift control by the above-described shift control device, FIG. 6 is a flowchart showing a subroutine of driving force priority mode determination in FIG. 5, and FIG. 7 is a step shift mode determination in FIG. It is a flowchart which shows a subroutine.

  As shown in FIG. 5, in step S1, it is determined whether or not the condition for setting the driving force priority mode is satisfied. When the condition for setting the driving force priority mode is satisfied, the driving force priority mode flag DF is turned on and the release condition is set. When established, the flag DF is turned off. In step S2, it is determined whether or not the condition for the step shift mode is satisfied. When the condition for the step shift mode is satisfied, the step shift mode flag SF is turned on, and when the release condition is satisfied, the flag SF is turned off. If it is determined in step S3 that the condition for setting the stepped speed change mode is not satisfied, the target speed is calculated based on the steady speed change mode in step S4, and the target speed ratio is calculated from the target speed in step S5. Shift control is then performed (step S6).

  On the other hand, if it is determined in step S7 that the condition for setting the driving force priority mode is not satisfied, the target rotational speed Np of the step shift mode is calculated in step S8. On the other hand, when the condition for setting the driving force priority mode is established and it is determined in step S9 that the target rotational speed Np is higher than the upper limit rotational speed NPH in the step shift mode, the driving power priority mode is determined in step S10. The target rotational speed Np is calculated. On the other hand, if it is determined as NO in step S9, step S8 is executed. As described above, the driving force priority mode is set when the condition for setting the step shift mode is established in step S3 and the condition for setting the driving force priority mode is satisfied in step S9. When a request for rapid acceleration is determined from the amount of pedal operation, the step shift mode is set first, and when the amount of depression of the accelerator pedal is fully open or close to it, the driving force priority mode is set.

  As shown in FIG. 6, in step S11, it is determined whether or not the accelerator pedal depression amount Pd is smaller than the first set value Pdl. In step S12, the accelerator pedal depression amount Pd is larger than the second set value Pdh. It is determined whether or not. However, the second set value Pdh is set to a value larger than the first set value Pdl (Pdh> Pdl), and the second set value Pdh is set to a value when the accelerator pedal is fully opened or almost fully opened. Is set. When the accelerator pedal depression amount Pd is smaller than the first set value Pdl, the driving force priority mode flag DF is turned off at step S13, and when the accelerator pedal depression amount Pd is larger than the second set value Pdh, at step S14. The driving force priority mode flag DF is turned on. If the depression amount Pd is an intermediate value between the two set values (Pdl <Pd <Pdh), the mode at that time is maintained, and if the drive priority mode is set at that time, that mode is selected in step S15. maintain. Therefore, the stepping amount when switching from the step shifting mode to the driving force priority mode is different from the stepping amount when switching from the driving force priority mode to the step shifting mode. Is set.

  As shown in FIG. 7, it is determined in step S21 whether or not the driving force priority mode flag DF is set. When the driving force priority mode is released, that is, off (DF = 0), there are a steady transmission mode and a step transmission mode, and the step transmission mode is set. When the conditions of steps S22 and S23 are satisfied, the step shift mode flag SF is turned off in step S24 to release the step shift mode. First, in step S22, it is determined whether a release condition for the step shift mode based on the lateral G is satisfied. This determination condition is determined by whether or not the state in which the lateral G absolute value is equal to or less than the predetermined value Ga (| G | ≦ Ga) continues for a predetermined time. Establish.

  Further, in step S23, it is determined whether or not a release condition for the step shift mode based on the opening degree is satisfied, and it is determined that the release condition is satisfied when any of the following three conditions is satisfied. The first condition is when the accelerator pedal depression amount Pd is not less than the predetermined value Pdl1 and not more than the predetermined value Pdl2 and the acceleration / deceleration ΔV is not more than the predetermined value ΔV1 for a predetermined time. That is, this is a case where Pdl1 ≦ Pd ≦ Pdl2 and ΔV ≦ ΔV1 continues for a predetermined time. The second condition is when the accelerator pedal depression amount Pd is equal to or less than a predetermined value Pdl3 and the vehicle speed V is equal to or less than a predetermined vehicle speed V1. That is, Pd ≦ Pdl3 and V ≦ V1. The third condition is when the accelerator pedal is released and the target rotational speed Np is equal to or lower than the initial rotational speed Npin in the step shift mode. That is, Pd = 0 and Np ≦ Npin.

  Thus, when the release condition based on the lateral G absolute value is satisfied in step S22 and the release condition based on the opening degree is satisfied in step S23, step S24 is executed and the step shift mode flag SF is turned off. The step shift mode is canceled.

  When it is determined in step S21 that the driving force priority mode flag DF is turned on, and even if the driving force priority mode flag DF is turned off, the step shift mode release condition is satisfied in either step S22 or S23. If it is determined that there is not, step S25 is executed. If YES is determined in any of steps S25 to S27, stepped shift mode flag SF is turned on in step S28. That is, when traveling in the driving force priority mode and when the condition for releasing the step shift mode is not satisfied, the step shift mode flag SF is turned on and set to this mode if a predetermined condition is satisfied.

  First, in step S25, it is determined whether an opening speed determination condition is satisfied. The opening speed determination condition is that the depression amount Pd becomes equal to or greater than the predetermined value Pd4 within a predetermined time after detecting that the accelerator pedal depression speed ΔPd has reached the predetermined value ΔPd1, and the vehicle speed V is equal to or higher than the predetermined vehicle speed V2. Is the case. That is, it is a case where Pd ≧ Pd4 or more and V ≧ V2 within a predetermined time from detection of ΔPd ≧ ΔPd1. When this condition is satisfied, step S28 is executed to switch to the step shift mode. As described above, when the acceleration request becomes equal to or higher than the predetermined value when the vehicle speed is equal to or higher than the predetermined value, the step shift mode is switched.

  In step S26, it is determined again whether or not the driving force priority mode flag DF is turned on. If it is turned on, step S28 is executed. In step S27, the state where the lateral G absolute value has reached the predetermined value Gb continues for a predetermined time and the vehicle speed V is equal to or higher than the predetermined value V3. That is, it is determined whether or not G ≧ Gb continues for a predetermined time and V ≧ V3. When this condition is satisfied, step S28 is executed. As described above, when it is determined in any of steps S25 to S27 that the condition for switching to the step shift mode is satisfied, the step shift mode is set, and in step S25, it is determined that the opening speed determination condition is not satisfied. Even so, if it is determined in step S26 that the driving force priority mode flag DF is turned on, step S28 is executed. Even if NO is determined in step S26, the lateral G determination condition is satisfied in step S27. If it is determined that there is, step S28 is executed. When it is determined NO in steps S25 to S27, step S29 is executed and the current step shift mode is maintained.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, although the continuously variable transmission shown in FIG. 1 is a belt type, a toroidal in which a power roller is disposed as a power transmission element between an input side disk as an input side rotating body and an output side disk as an output side rotating body. The present invention may be applied to control of a continuously variable transmission.

It is the schematic which shows the drive system of the vehicle provided with the belt-type continuously variable transmission as an example of an automatic transmission. It is the schematic which shows the transmission control apparatus of a continuously variable transmission. FIG. 6 is a shift control characteristic diagram showing a relationship between a target speed of a primary pulley and a vehicle speed in a continuously variable transmission. (A) is a characteristic diagram showing the relationship between the upper limit rotational speed and the vehicle speed when the accelerator pedal is depressed and the throttle opening is changed in accordance with the traveling load of the vehicle, and (B) is similarly applied with a load. FIG. 6C is a characteristic diagram showing the relationship between the lower limit rotational speed and the vehicle speed when the upper limit rotational speed and the lower limit rotational speed are changed. FIG. It is a flowchart which shows the main routine of the shift control by a shift control apparatus. It is a flowchart which shows the subroutine of driving force priority mode determination in FIG. It is a flowchart which shows the subroutine of step shift mode determination in FIG.

Explanation of symbols

1 Engine 7 Primary pulley 8 Secondary pulley 9 Belt 30 Transmission control unit 31 Primary pulley rotational speed sensor 32 Secondary pulley rotational speed sensor 33 Engine rotational speed sensor 34 Throttle opening sensor 35 Vehicle speed sensor 36 Range detection sensor 37 Accelerator opening sensor 38 Lateral G sensor 39 Steering angle sensor 40 Inclination angle sensor 41 Load calculation unit (load calculation means)
42 Shift mode switching determination unit (shift mode switching determination means)
43 Rotational speed range setting section (Rotational speed range setting means)
44 Shift control unit (shift control means)

Claims (14)

A continuously variable transmission having an input-side rotator driven by an engine and an output-side rotator driven by a power transmission element by the input-side rotator and continuously changing a gear ratio, and driver acceleration an acceleration request detecting means for detecting a request, vehicle speed detecting means for detecting a vehicle speed, the control device of the continuously variable transmission that includes a load calculating means for calculating the amount of running resistance and the external load of the vehicle,
Before Symbol acceleration request sets the shift mode to the variable transmission mode when the above first setting value, the acceleration request is the driving force priority mode the shift mode in the case of more than larger second set value than the first set value Shift mode switching determining means to be set to
When the step shift mode is set, the upper limit rotational speed of the input-side rotating body rotational speed according to at least one of the throttle opening, the accelerator pedal opening, the intake air amount, and the intake pipe pressure and the vehicle speed And a rotation speed range setting means for setting the lower limit rotation speed,
When the step shift mode is set , the gear ratio is changed so that the lower limit rotation speed is reached when the input-side rotation speed reaches the upper limit rotation speed, and the driving force priority mode is set. In this case, the control device for the continuously variable transmission includes shift control means for changing a gear ratio toward a maximum speed change line in which the input side rotor speed is higher than the upper limit speed . The control device for a continuously variable transmission according to claim 1, and the load calculated by the load calculating means is equal to or higher than a predetermined value, if there is either One acceleration request, the upper limit after reaching the upper limit rotational speed A control device for a continuously variable transmission, characterized in that the speed ratio is maintained to maintain the rotational speed. The control device for a continuously variable transmission according to claim 2, wherein the variable transmission mode, the maximum rotation speed to maintain after reaching the upper rotational speed is prohibited to stepwise shift to the lower limit rotational speed A control device for a continuously variable transmission. The continuously variable transmission control device according to any one of claims 1 to 3 , wherein when the deceleration request by the engine brake is made during the step shift mode, the step shift mode is maintained and the lower limit rotational speed is set. A control device for a continuously variable transmission, characterized in that the vehicle is decelerated while maintaining a gear ratio until the speed reaches . The control device for a continuously variable transmission according to any one of claims 1 to 4 , wherein the upper limit rotation speed and the lower limit rotation speed are increased when the load amount tends to increase during traveling. A control device for a continuously variable transmission. The continuously variable transmission control device according to any one of claims 1 to 5 , wherein when the load amount tends to decrease, the upper limit rotational speed and the lower limit rotational speed are decreased. Transmission control device. The continuously variable transmission control device according to any one of claims 1 to 6 , wherein the gear ratio is increased when the load amount tends to increase. The continuously variable transmission control device according to any one of claims 1 to 7 , wherein the speed ratio is increased when a road surface gradient is a downward gradient and an acceleration request is not detected. Machine control device. The continuously variable transmission control device according to any one of claims 1 to 8 , wherein when the road surface gradient is a downward gradient, the lower limit rotational speed is increased in accordance with a load amount. Machine control device. The continuously variable transmission control device according to any one of claims 1 to 9 , further comprising a lateral G detection unit that detects an acceleration applied to the vehicle in a vehicle width direction, wherein the shift mode switching determination unit includes: A control device for a continuously variable transmission, wherein the shift mode is switched to a step shift mode when the magnitude of the absolute value of the lateral G detected by the lateral G detection means exceeds a predetermined value. A continuously variable transmission having an input-side rotator driven by an engine and an output-side rotator driven by the input-side rotator via a power transmission element and continuously changing a gear ratio; Lateral G detection means for detecting acceleration applied to the direction, vehicle speed detection means for detecting vehicle speed, load calculation means for calculating the running resistance of the vehicle and the amount of external load, and stepless speed change according to the lateral G A shift mode switching determination means for switching between a continuously variable transmission mode for changing the ratio and a stepped transmission mode for changing the transmission ratio stepwise, and in the stepped transmission mode, the throttle opening, the accelerator pedal opening, the intake air amount, and the intake A rotation speed range setting means for setting an upper limit rotation speed and a lower limit rotation speed of the input-side rotation speed according to at least one of the tube pressures and the vehicle speed; and the step shift mode A continuously variable transmission comprising: a speed change control means for stepwise controlling a speed ratio determined according to the vehicle speed between an upper limit speed and a lower limit speed set by the speed range setting means; In the control device,
The shift mode switching determination means sets the shift mode to a step shift mode when the magnitude of the lateral G absolute value detected by the lateral G detection means is equal to or greater than a predetermined value,
The shift control means, the control device for a continuously variable transmission, wherein the input side rotating member rotation speed changes the transmission ratio such that the lower limit engine speed reaches the maximum rotation speed. 12. The continuously variable transmission control device according to claim 11 , wherein when the lateral G absolute value increases, the upper limit rotational speed and the lower limit rotational speed are increased. 12. The control device for a continuously variable transmission according to claim 11 , wherein when the lateral G absolute value is greater than or equal to a predetermined value, a peak value of an accelerator opening value that sets the upper limit rotational speed is held and the upper limit rotational speed is calculated. A control device for a continuously variable transmission. The control device for a continuously variable transmission according to claim 11, when the lateral G absolute value is above a predetermined value, the aforementioned maximum rotation speed to maintain after reaching the upper limit rotation speed, stepwise to the lower limit rotational speed A control device for a continuously variable transmission, which prohibits shifting.

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