JP2005308046A - Speed change controller for continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speed change controller for a continuously variable transmission capable of restraining frequent switching of speed change ratios caused by delicate changes of speed of a vehicle displayed on a displaying device. <P>SOLUTION: In the speed change controller, the controller can select a target input number of rotation on the basis of operation of an operating device and a target input number of rotation on the basis of an operating state of the vehicle, and controls a speed change ratio so as to make a real input number of rotation of the continuously variable transmission approximate the target input number of rotation, and also have the displaying device displaying speed change ratios. When the target input number of rotation is changed by operation of the operating device or the target input number of rotation of the continuously variable transmission is approximately controlled at a constant level on the basis of a braking demand of the vehicle, the controller comprises a first displaying means (step S26) for displaying the speed change ratio in response to the target input number of rotation on the displaying device, and a second displaying means (step S28) for displaying the speed change ratio in response to the target input number of rotation on the displaying device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmission control device for a continuously variable transmission capable of continuously controlling a gear ratio.

  2. Description of the Related Art Conventionally, there has been known a control in which an operating state of an engine is brought close to an optimum state by providing a continuously variable transmission on the output side of the engine and controlling a speed ratio of the continuously variable transmission continuously. As such a continuously variable transmission, a continuously variable transmission having a belt-type continuously variable transmission, a toroidal continuously variable transmission, an electric motor, and a planetary gear mechanism is known. Among these, an example of a power train of a vehicle having a belt type continuously variable transmission is described in Patent Document 1 below. In the power train described in Patent Document 1, the torque output from the engine is transmitted to the drive wheels via the starting clutch, the forward / reverse switching device, the belt-type continuously variable transmission, and the final reduction gear. It has become. The belt-type continuously variable transmission has a primary pulley, a secondary pulley, and a belt. By controlling the hydraulic pressure supplied to the hydraulic chamber of the primary pulley with a shift control actuator, the speed of the belt-type continuously variable transmission is changed. Control takes place.

  On the other hand, when performing the shift control of the continuously variable transmission, the automatic shift mode and the manual shift mode can be selected. Specifically, the automatic transmission mode is selected when the select lever provided in the console box in the vehicle interior is set in the drive range. On the other hand, it can be selected by moving the select lever to a manual transmission slot provided beside the drive range, and at this time, the manual switch is turned on. The manual transmission slot is provided with an upshift position and a downshift position, and an upshift switch according to the upshift position and a downshift switch according to the downshift position. The meter panel provided in the driver's seat is provided with a shift speed display means for displaying the shift speed in the manual shift mode.

  Furthermore, the gear ratio, which is the ratio between the input rotation speed and the output rotation speed in the manual shift mode, is divided into six speed stages and stored in the transmission control device. When the manual transmission mode is selected, the target gear ratio corresponding to the gear set by the driver is set based on the ON signal of the upshift switch or the downshift switch, and the input rotation speed and output rotation speed are set. The gearshift control actuator is controlled so that the actual gear ratio, which is the ratio between the two, converges to the target gear ratio. In addition, when the input speed is below the lower limit of the allowable shift range, it is automatically downshifted to the first gear, and automatically when the input speed reaches the overspeed range that is the upper limit of the allowable shift range. Upshifted to

On the other hand, the actual speed ratio is calculated based on the input speed and the output speed, the actual speed ratio is compared with a preset fixed ratio for each gear position, and the actual speed ratio is any fixed speed ratio. When it is within the permissible width, the shift stage corresponding to this fixed gear ratio is displayed on the shift display means. Furthermore, even when it is determined that the driving wheel is in a locked state by a sudden braking operation, the vehicle body is moved by inertial force. Therefore, even if the manual transmission mode is selected, the pseudo vehicle speed is obtained from the output rotational speed and the deceleration, the target speed ratio is set based on the pseudo speed, and the continuously variable transmission of the continuously variable transmission is set based on the target speed ratio. The gear ratio is downshifted, and the gear position corresponding to the pseudo vehicle speed is displayed on the gearshift display means. The invention relating to the display device for displaying the shift state of the automatic transmission is also described in Patent Document 2 and Patent Document 3.
JP 10-318367 A JP-A-11-157354 JP 2002-147605 A

  However, in the gear position display device described in Patent Document 1, since the pseudo vehicle speed is obtained based on the output rotation speed and the deceleration, the pseudo vehicle speed is changed when the output rotation speed is changed due to slipping of the drive wheels. Corresponding to the above, there is a possibility that the gear position displayed by the gear shift display means is frequently switched.

  The present invention has been made against the above circumstances, and is displayed on a display device due to a subtle change in the vehicle speed when the vehicle is decelerated at a low vehicle speed and the gear ratio of the continuously variable transmission is increased. An object of the present invention is to provide a transmission control device for a continuously variable transmission that can suppress frequent switching of the transmission gear ratio.

  In order to achieve the above object, the invention of claim 1 is directed to a continuously variable transmission that is obtained based on a target input rotational speed of a continuously variable transmission that is obtained based on an operation of an operating device and a driving state of a vehicle. It is possible to selectively switch between the target input speed and the input speed and output speed of the continuously variable transmission so that the actual input speed of the continuously variable transmission approaches the selected target input speed. In the transmission control device for a continuously variable transmission having a display device for displaying the transmission ratio of the continuously variable transmission, the operation device is operated to change the target input rotational speed. Or when a braking request for a vehicle is generated without operating the operating device and the target input rotational speed of the continuously variable transmission is controlled to be substantially constant, the gear ratio according to the target input rotational speed Is displayed on the display device. When the target input rotational speed of the continuously variable transmission is increased when the vehicle is not operated, the vehicle braking request is not generated, and the vehicle travels at a low vehicle speed, And second display means for smoothing and displaying the gear ratio in accordance with the target input rotational speed and displaying it on the display device.

  In the invention of claim 2, in addition to the configuration of claim 1, when the target input rotational speed requested by the operation of the operating device is outside the allowable range, the target input rotational speed within the allowable range is selected, In addition, the display device further includes third display means for displaying on the display device that the requested target rotational speed is outside the allowable range.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the display device further includes fourth display means for displaying a speed ratio corresponding to the target input rotation speed on the display device. It is what.

  According to the first aspect of the invention, when the operation device is operated to change the target input rotation speed, or the operation device is not operated and a braking request for the vehicle is generated, the target input rotation speed of the continuously variable transmission. Is controlled to be substantially constant, a gear ratio corresponding to the target input rotational speed is displayed on the display device. On the other hand, when the target input speed of the continuously variable transmission is to be increased in order to travel at a low vehicle speed without operating the operating device and without requiring braking of the vehicle, the target input speed The speed change ratio corresponding to is smoothed and displayed on the display device. Therefore, when the vehicle is decelerated at a low vehicle speed, frequent switching of the gear ratio displayed on the display device can be suppressed even if the vehicle speed slightly changes.

  According to the invention of claim 2, in addition to obtaining the same effect as that of the invention of claim 1, the occupant of the vehicle recognizes that the target input rotational speed requested by operating the operating device is outside the allowable range. Can be made.

  According to the invention of claim 3, in addition to obtaining the same effect as that of the invention of claim 1 or 2, the gear ratio corresponding to the target input rotational speed is displayed on the display device. This eliminates the delay in changing the gear ratio and avoids the driver's uncomfortable feeling.

  Next, an embodiment of the present invention will be described with reference to the drawings. First, FIG. 2 shows an example of a power train of a vehicle to which the present invention can be applied and a control system of the vehicle. A vehicle Ve shown in FIG. 2 has an engine 1 as a power source. The engine 1 can be an internal combustion engine, more specifically, a gasoline engine, a diesel engine, an LPG engine, or the like. The engine 1 is a known one having an electronic throttle valve (not shown). The power of the engine 1 is configured to be transmitted to the wheels 2, and the power transmission path from the engine 1 to the wheels 2 includes a fluid transmission device 3, a lockup clutch 4, a forward / reverse switching mechanism 5, a belt type continuously variable. A transmission 6 and the like are provided.

  The fluid transmission device 3 and the lockup clutch 4 are provided in a power transmission path between the engine 1 and the forward / reverse switching mechanism 5, and the fluid transmission device 3 and the lockup clutch 4 are arranged in parallel to each other. Has been. The fluid transmission device 3 is a device that transmits power by the kinetic energy of the fluid, and the lockup clutch 4 is a device that transmits power by a frictional force. The forward / reverse switching mechanism 5 is a device provided for selectively switching the rotation direction of the output member relative to the input member.

  The belt-type continuously variable transmission 6 is provided in a power transmission path between the forward / reverse switching mechanism 5 and the wheel 2, and the belt-type continuously variable transmission 6 has an input rotation speed (input rotation speed) and an output rotation. This is a transmission capable of controlling a speed ratio, which is a ratio to a speed (output rotational speed), in a stepless manner (continuously). This belt type continuously variable transmission 6 has a primary shaft 7 and a secondary shaft 8 arranged in parallel to each other. The primary shaft 7 is provided with a primary pulley 9, and the secondary shaft 8 is provided with a secondary pulley 10. The primary pulley 9 has a fixed sheave 11 fixed to the primary shaft 7 and a movable sheave 12 configured to be movable in the axial direction of the primary shaft 7. A groove M <b> 1 is formed between the fixed sheave 11 and the movable sheave 12.

  Further, a hydraulic servo mechanism 13 is provided for moving the movable sheave 12 in the axial direction of the primary shaft 7 so that the movable sheave 12 and the fixed sheave 11 approach and separate from each other. The hydraulic servo mechanism 13 includes a hydraulic chamber 19 and a piston (not shown) that operates in the axial direction of the primary shaft 7 according to the amount of hydraulic oil in the hydraulic chamber 19 and is connected to the movable sheave 12. ing.

  On the other hand, the secondary pulley 10 has a fixed sheave 14 fixed to the secondary shaft 8 and a movable sheave 15 configured to be movable in the axial direction of the secondary shaft 8. A V-shaped groove M <b> 2 is formed between the fixed sheave 14 and the movable sheave 15.

  In addition, a hydraulic servo mechanism 16 is provided that moves the movable sheave 15 in the axial direction of the secondary shaft 8 to bring the movable sheave 15 and the fixed sheave 14 closer to or away from each other. The hydraulic servo mechanism 16 includes a hydraulic chamber 100 and a piston (not shown) that operates in the axial direction of the secondary shaft 8 by the hydraulic pressure of the hydraulic chamber 100 and is connected to the movable sheave 15. An endless belt 17 is wound around the primary pulley 9 and the secondary pulley 10 configured as described above.

  On the other hand, a hydraulic control device 18 having a function of controlling the hydraulic servo mechanisms 13 and 16 and the lockup clutch 4 and the forward / reverse switching mechanism 5 of the belt type continuously variable transmission 6 is provided. Further, an electronic control device 52 as a controller for controlling the engine 1, the lockup clutch 4, the forward / reverse switching mechanism 5, the belt type continuously variable transmission 6, and the hydraulic control device 18 is provided. An arithmetic processing unit (CPU or MPU), a storage unit (RAM and ROM), and a microcomputer mainly including an input / output interface are included.

  The electronic control unit 52 includes an operation state of the shift position selection device 50, an operation state of the transmission mode selection device 51, an operation state of the transmission ratio selection device 53, an engine speed, an acceleration request (for example, an operation state of an accelerator pedal, an idle state) Detection signals such as a switch on / off), a braking request (for example, an operating state of a brake pedal), an opening degree of a throttle valve, a rotation speed of the primary shaft 7, and a rotation speed of the secondary shaft 8 are input. As the shift position selection device 50, various configurations such as a lever type, a push button type, a touch panel type, and a rotary knob type can be used. Further, the shift position selecting device 50 may have either a structure operated with a foot or a structure operated with a hand. By operating the shift position selection device 50 by a passenger of the vehicle Ve, a parking (P) position, a reverse (R) position, a neutral (N) position, a drive (D) position, and the like can be selectively switched. .

  Here, when the reverse position is selected, the gear ratio of the belt-type continuously variable transmission 6 is fixed, and when the drive position is selected, the gear ratio of the belt-type continuously variable transmission 6 can be fixed or changed. It is. In order to control the gear ratio of the belt-type continuously variable transmission 6, the automatic transmission mode or the manual transmission mode is selected by operating the transmission mode selection device 51. When the automatic transmission mode is selected, a signal input to the electronic control unit 52, for example, a driving state of the vehicle Ve, more specifically, a signal such as a vehicle speed, an acceleration request, a braking request, and the like, and the electronic control unit 52 It is possible to control the belt type continuously variable transmission 6 based on the data stored in. In the manual transmission mode, the belt-type continuously variable transmission 6 can be controlled based on the operation state of the transmission ratio selection device 53 and data stored in the electronic control device 52.

  The gear ratio selecting device 53 can use various configurations such as a lever type, a push button type, a touch panel type, and a rotary knob type. Here, description will be made assuming that the gear ratio selection device 53 has a downshift lever 53A and an upshift lever 53B. On the other hand, from the electronic control unit 52, a signal for controlling the engine 1, a signal for controlling the belt-type continuously variable transmission 6, a signal for controlling the forward / reverse switching mechanism 5, a signal for controlling the lock-up clutch 4, a hydraulic control unit 18 And a signal for controlling the display device (indicator) 54 are output. The display device 54 has a function of displaying the shift position selected by the shift position selection device 50 and displaying the gear ratio of the belt type continuously variable transmission 6. The display device 54 can output the shift position and the gear ratio by a buzzer, a speaker, a lamp, a liquid crystal device, a light emitting diode, or the like.

  When the engine 1 is operated in the vehicle Ve configured as described above, the engine torque is transmitted to the belt type continuously variable transmission via the fluid transmission device 3 or the lockup clutch 4 and the forward / reverse switching mechanism 5. 6 to the primary shaft 7. Torque transmitted to the primary shaft 7 is transmitted to the secondary shaft 8 via the primary pulley 9, the belt 17, and the secondary pulley 10. Then, torque is transmitted from the secondary shaft 8 to the wheel 2 to generate driving force.

  On the other hand, various data are stored in the electronic control device 52, and the engine 1, the belt type continuously variable transmission 6, based on the signal input to the electronic control device 52 and the stored data. The forward / reverse switching mechanism 5, the lockup clutch 4, the hydraulic control device 18 and the like are controlled. The hydraulic control device 18 includes a hydraulic circuit (not shown) and a solenoid valve (not shown). By controlling the solenoid valve, the hydraulic oil in the hydraulic circuit is supplied to the hydraulic chambers 19 and 100. In addition, pressure oil is discharged from the hydraulic chambers 19 and 100.

  First, the shift control of the belt-type continuously variable transmission 6 will be described. By controlling the flow rate of the pressure oil supplied to the hydraulic chamber 19, the thrust for moving the movable sheave 12 of the primary pulley 9 in the axial direction is adjusted. Is done. In addition, the hydraulic pressure in the hydraulic chamber 100 is controlled to adjust the thrust that moves the movable sheave 15 of the secondary pulley 10 in the axial direction. In the belt-type continuously variable transmission 6, the width of the groove M <b> 1 of the primary pulley 9 and the groove M <b> 2 of the secondary pulley 10 depend on the correspondence between the thrust applied to the movable sheave 12 and the thrust applied to the movable sheave 15. , And the ratio between the winding radius of the belt 17 in the primary pulley 9 and the winding radius of the belt 17 in the secondary pulley 10 changes. In this way, the transmission gear ratio, which is the ratio between the rotation speed (input rotation speed) of the primary shaft 7 and primary pulley 9 and the rotation speed (output rotation speed) of the secondary shaft 8 and secondary pulley 10, is controlled, and The torque capacity of the belt type continuously variable transmission 6 is controlled.

  Next, a mode for controlling the belt type continuously variable transmission 6 will be described. First, when the drive position is selected and the automatic transmission mode is selected, basically, the gear ratio of the belt type continuously variable transmission 6 is controlled so that the operating state of the engine 1 becomes the optimum fuel consumption state. Is done. For example, the required driving force in the vehicle Ve is obtained based on the vehicle speed and the accelerator opening, and the target engine output corresponding to the required driving force, that is, the rotation speed and the torque are obtained. Then, when the actual engine output is brought close to the target engine output, the target engine speed is obtained based on the optimum fuel consumption map stored in the electronic control unit 52, and the actual engine speed is made closer to the target engine speed. Is executed. Specifically, the gear ratio of the belt-type continuously variable transmission 6 is controlled based on the shift map stored in the electronic control unit 52, and the engine speed is controlled. In parallel with this engine speed control, control is performed to bring the actual engine torque closer to the target engine torque by controlling the electronic throttle valve and the like.

  On the other hand, when the manual transmission mode is selected, the driver can arbitrarily control the transmission ratio of the belt type continuously variable transmission 6 under conditions different from those used in the automatic transmission mode. It is. Here, the “condition different from the condition used in the automatic transmission mode” includes the operation state of the transmission ratio selection device 53. For example, when the downshift lever 53A is operated, a downshift, that is, a shift that increases the gear ratio of the belt type continuously variable transmission 6 is executed. On the other hand, when the upshift lever 53B is operated, an upshift, that is, a shift that reduces the gear ratio of the belt type continuously variable transmission 6 is executed.

  Further, when the manual shift mode is selected, a step shift operation and a continuous shift operation can be executed. The step shift operation means that the downshift lever 53A or the upshift lever 53B is operated for a short time that is a predetermined time or less. The continuous shift operation means that the downshift lever 53A or the upshift lever 53B is operated for a long time exceeding a predetermined time. Thus, when the manual transmission mode is selected, the target transmission ratio of the belt-type continuously variable transmission 6 can be controlled by operating the transmission ratio selection device 53.

  When the step shift operation is executed, a plurality of shift speeds set in advance in the electronic control unit 52 as the target gear ratio of the belt-type continuously variable transmission 6, for example, the first to seventh shift speeds, for example. Either of these can be selected. The first to seventh speed gears are terms that divide different gear ratios in stages. A mode in which control (sequential shift) is performed to bring the actual speed ratio of the belt-type continuously variable transmission 6 closer to the target speed ratio selected by the step speed change operation is referred to as a step speed change mode.

  Here, the speed ratio corresponding to the first speed is larger than the speed ratio corresponding to the second speed, the speed ratio corresponding to the second speed is larger than the speed ratio corresponding to the third speed, and the third speed The gear ratio corresponding to the fourth speed is larger than the gear ratio corresponding to the fourth speed, the gear ratio corresponding to the fourth speed is larger than the gear ratio corresponding to the fifth speed, and the gear ratio corresponding to the fifth speed is The gear ratio corresponding to the sixth speed is larger than the gear ratio corresponding to the seventh speed.

  As described above, when the step shift operation is executed, one of the respective shift stages is selected as the target transmission ratio of the belt-type continuously variable transmission 6, and the step shift mode is executed. Here, in the shift control based on the step shift operation, the belt-type continuously variable transmission is set to a gear ratio (intermediate gear ratio) corresponding to a gear ratio (reference gear ratio) corresponding to a preset gear position. The gear ratio of the machine 6 is not fixed.

  On the other hand, when a continuous speed change operation is executed, it is possible to select a speed ratio corresponding to each speed stage from the first speed to the seventh speed as the target speed ratio of the belt-type continuously variable transmission 6. In addition, it is possible to select a gear ratio corresponding to the gear ratios corresponding to the first to seventh gears as the target gear ratio. A mode in which the speed ratio of the belt-type continuously variable transmission 6 is controlled based on the continuous speed change operation is referred to as a continuous speed change mode. In this embodiment, when the manual transmission mode is selected, the shift control of the belt type continuously variable transmission 6 is executed based on a condition different from the operation of the downshift lever 53A and the upshift lever 53B. There is. This control will be described later.

  Next, an example of the shift control of the belt type continuously variable transmission 6 and the display control of the display device 54 will be described based on a control routine divided and shown in FIGS. 1, 3, and 4. First, as shown in FIG. 3, when the control is started, the flag (FLAG) 1 is turned off (step S1). The meaning of this flag will be described later. Following this step S1, it is determined whether or not the manual transmission mode is selected (step S2). If the determination in step S2 is affirmative, it is determined whether or not the continuous transmission mode is selected (step S3). If a negative determination is made in step S3 or step S2, the control routine is terminated.

  On the other hand, when a positive determination is made in step S3, it is determined whether or not the downshift lever 53A or the upshift lever 53B is operated (step S4). If the determination in step S4 is affirmative, it is determined whether or not the downshift lever 53A or the upshift lever 53B was operated when this control routine was executed last time (step S5). When a negative determination is made in step S5, the input rotational speed KNINSTEP calculated based on the operation of the downshift lever 53A or the upshift lever 53B is set as the target input rotational speed NINT of the belt type continuously variable transmission 6. The selection process is executed (step S6).

  In step S6, the target input rotation speed is selected based on the data stored in the electronic control unit 52. For example, the degree of increase in the target input rotational speed is determined based on the operation of the downshift lever 53A, and the input rotational speed KNINSTEP calculated when the downshift operation is executed is determined according to the downshift operation. Means the input rotation speed to be increased stepwise. On the other hand, the degree of decrease in the target input rotational speed is determined based on the operation of the upshift lever 53B. The input rotational speed KNINSTEP calculated when the upshift operation is performed means an input rotational speed that should be decreased stepwise in accordance with the upshift operation. The routine that proceeds from step S5 to step S6 as described above is step shift control in the initial stage of the continuous shift mode.

  Here, FIG. 5 shows an example of a map used for obtaining the target input rotation speed in this embodiment. In the map shown in FIG. 5, the abscissa indicates the vehicle speed, and the ordinate indicates the target input rotation speed of the belt type continuously variable transmission 6. In FIG. 5, with the target input rotational speed of the belt-type continuously variable transmission 6 and the vehicle speed as parameters, the shift line A1 corresponding to the first speed, the shift line A2 corresponding to the second speed, and the third speed are supported. A shift line A3, a shift line A4 corresponding to the fourth speed, a shift line A5 corresponding to the fifth speed, a shift line A6 corresponding to the sixth speed, and a shift line A7 corresponding to the seventh speed are shown. Each shift line has a characteristic that the target input rotational speed increases as the vehicle speed increases. Then, when a shift operation is executed in the step shift mode, the shift lines A1 to A7 shown in FIG. 5 are selectively switched, and the belt-type continuously variable transmission 6 is based on the shift lines A1 to A7. Target input speed is selected.

  In FIG. 5, a line segment B1 corresponds to the maximum rotation speed guard NINMAX of the target input rotation speed, and a line segment B2 corresponds to the minimum rotation speed guard NINMIN of the target input rotation speed. The maximum engine speed guard NINMAX is set to prevent the engine speed from increasing above a predetermined engine speed, and the minimum engine speed guard NINMIN is used to prevent the engine engine speed from decreasing below a predetermined engine speed. Set to The maximum speed guard NINMAX and the minimum speed guard NINMIN are set to a substantially constant speed regardless of the vehicle speed. The target input speed indicated by the shift line A1 corresponds to the maximum speed ratio γmax guard, and the target input speed indicated by the speed line A7 corresponds to the minimum speed ratio γmin guard.

  Here, the maximum transmission gear ratio and the minimum transmission gear ratio of the belt type continuously variable transmission 6 are determined based on the effective inner and outer diameters of the primary pulley 9 and the secondary pulley 10. Further, a region surrounded by the shift line A1, the shift line A7, the line segment B1, and the line segment B2 is the shiftable region X1, and the outside of the shiftable region X1 is the non-permitted region X2. When the above-described continuous shift operation is executed, the target input rotation speed of the belt type continuously variable transmission 6 can be controlled corresponding to each shift line A1 to shift line A7. In the map of FIG. 5, it is also possible to set the target input rotation speed between the respective shift lines as long as it is within the shift possible region X1.

  Subsequent to step S6, the flag 1 is turned on (step S7), and the process proceeds to step S8 in FIG. On the other hand, if the determination in step S5 is affirmative, the target input rotational speed NINT calculated during the previous routine execution and the rotational speed KCONTINUE according to the continuous operation of the downshift lever 53A or the upshift lever 53B And a process of substituting a value obtained by dividing the new target input speed NINT by the actual output speed NOUT as the target gear ratio γT. (Step S9), the process proceeds to Step S7.

  On the other hand, if the processing of steps S5, S6, and S7 as described above is executed, and then this control routine is terminated and the negative determination is made in step S4 when the next control routine is executed, braking is performed. It is determined whether there is a request (step S10). The determination in step S10 can be executed based on, for example, on / off of the brake switch. If the brake switch is turned on and a positive determination is made in step S10, it is determined whether or not the brake switch was turned on when the previous control routine was executed (step S11). If the brake switch is switched from OFF to ON between the previous execution of the control routine and the execution of the current control routine, a negative determination is made in step S11 and the process proceeds to step S12. In step S12, a process is performed in which the actual input rotation speed NINT at the time when the brake switch is switched from OFF to ON is handled as the target input rotation speed NINTBKON for turning on the brake switch, and the process proceeds to step S13. If the determination in step S11 is affirmative, the process proceeds to step S13 without executing the process in step S12.

  In step S13, a process of substituting the target input speed NINTBKON for the target input speed NINT and a value obtained by dividing the target input speed NINT by the actual output speed NOUT is set as the target speed ratio γT. Substitution processing is executed. That is, the target gear ratio γT is controlled so as to maintain the actual input rotational speed NINT when the brake switch is switched from OFF to ON. That is, even if the vehicle speed decreases, the target input rotational speed is controlled to be substantially constant. When the process of step S13 is executed, the process proceeds to step S7.

  By the way, when the control routine is finished through step S11 and step S13 and the process proceeds to step S10 again and a negative determination is made, the target gear ratio γT at the time when the brake switch is switched from OFF to ON is set. Then, the control for obtaining the target input rotational speed NINT by multiplying the actual output rotational speed NOUT is executed (step S14). By the process of step S14, the target gear ratio γT at the time when the brake switch is switched from OFF to ON is maintained, and the process proceeds to step S8.

  As described above, when the gear ratio selection device 53 is operated, or when the gear ratio selection device 53 is not operated and there is a braking request, the routine proceeds to step S7 and the flag 1 is turned on. On the other hand, in the routine in which the gear ratio selection device 53 is not operated and there is no braking request and the process goes through step S14, the flag 1 is kept off.

  The process when the process proceeds to step S8 as described above will be described. In this step S8, it is determined whether or not the target input rotational speed NINT calculated in any of the steps described above exceeds the maximum rotational speed guard NINMAX of the target input rotational speed. If the determination in step S8 is affirmative, the process of substituting the maximum input speed guard NINMAX for the target input speed as the final target input speed NINT and the maximum speed guard NINMAX for the input speed are: FIG. 5 shows a process of substituting the speed ratio calculated by dividing the actual output speed NOUT into the target speed ratio γT, and the target input speed NINT before substituting the maximum speed guard NINMAX of the target input speed. In step S15, the process proceeds to step S16, in which the display device 54 displays that it is in the non-permission area (reject area) X2.

  On the other hand, if a negative determination is made in step S8, the value obtained by multiplying the maximum speed ratio γmax of the belt type continuously variable transmission 6 by the actual output speed NOUT is less than the target input speed NINT. It is determined whether or not there is (step S17). If the determination in step S17 is affirmative, the value obtained by multiplying the maximum speed ratio γmax and the actual output speed NOUT is substituted as the final target input speed NINT, and this target A process of substituting the maximum speed ratio γmax corresponding to the guard value of the input rotational speed into the target speed ratio γT is executed (step S18), and the process proceeds to step S16. In step S18, the target input speed NINT before substituting the value obtained by multiplying the maximum speed ratio γmax and the actual output speed NOUT as the final target input speed NINT is not permitted. A process of displaying the fact that it is in X2 by the display device 54 is executed.

  Further, when a negative determination is made in step S17, it is determined whether or not a value obtained by multiplying the minimum speed ratio γmin and the actual output rotational speed NOUT exceeds the target input rotational speed NINT ( Step S19). If the determination in step S19 is affirmative, processing for substituting a value obtained by multiplying the minimum speed ratio γmin and the actual output speed NOUT into the final target input speed NINT, and the minimum speed ratio The process of substituting γmin into the target gear ratio γT is executed (step S20), and the process proceeds to step S16. In step S20, the target input speed NINT before the value obtained by multiplying the minimum speed ratio γmin and the actual output speed NOUT into the final target input speed NINT is a non-permitted area. A process of displaying the fact that it is in X2 by the display device 54 is executed.

  Further, if a negative determination is made in step S19, it is determined whether or not the target input rotational speed NINT calculated in the step upstream from step S8 is less than the minimum rotational speed guard NINMIN of the target input rotational speed. (Step S21). If the determination in step S21 is affirmative, a process of substituting the minimum input speed guard NINMIN for the target input speed shown in the map of FIG. 5 as the final target input speed NINT, and the minimum speed A process of substituting the speed ratio calculated by dividing the guard NINMIN by the actual output speed NOUT into the target speed ratio γT, and the target input speed NINT before substituting the minimum speed guard NINMIN of the target input speed However, the process which displays that it exists in the non-permission area | region X2 by the display apparatus 54 is performed (step S22), and it progresses to step S16. If a negative determination is made in step S21, the process proceeds to step S16 without executing the process in step S22. In this step S16, the process shown by the following mathematical formula is executed, and a predetermined gear stage (n = SFT) in the following mathematical formula is calculated.

  NINSS (n) <NINT <NINSS (n + 1)

  Here, “NINSS” is a target input rotational speed corresponding to one of the gear positions shown in the map of FIG. 5, “NINT” is a target input rotational speed currently selected, and “n + 1”. Is a gear position one speed higher than the predetermined gear speed “n”. That is, the current target input rotational speed NINT is higher than the target input rotational speed NINSS corresponding to the predetermined shift speed n, and the target corresponding to the shift speed one stage higher than the predetermined shift speed n. When the rotational speed is lower than the input rotational speed NINSS, a predetermined gear stage n on the low speed side is obtained. For example, if the current target input speed is between the target input speed corresponding to the third speed and the target input speed corresponding to the fourth speed, the third speed is a predetermined shift speed. .

  Subsequent to step S16, the process of step S23 of FIG. 1 is executed. In this step S23, at the current vehicle speed Vn, a target input rotational speed A corresponding to a predetermined gear stage (n) and a target input rotational speed B corresponding to a high speed side gear stage (n + 1) are obtained. When the target input rotational speed corresponding to the predetermined gear stage (n) and the target input rotational speed corresponding to the high speed side gear stage (n + 1) are both the minimum rotational speed guard corresponding to the line segment B2. In step S23, the vehicle speed Va at the intersection of the line segment corresponding to the predetermined gear stage (n) and the line segment B1 is obtained, and the line segment corresponding to the high speed gear stage (n + 1) and the line The vehicle speed Vb at the intersection with the minute B1 is obtained. Following this step S23, the processing of the following mathematical formula is executed (step S24).

  DSFT = (NINT-A) / (BA) * 100 (%)

  Here, DSFT is the ratio of the intermediate gear ratio between the respective gears, and the duty value corresponding to the ratio of the intermediate gear ratio is calculated. As described above, the target input rotation speed corresponding to the predetermined shift speed (n) and the target input rotation speed corresponding to the high speed shift speed (n + 1) are both the minimum rotation corresponding to the line segment B2. If it is a number guard, the processing of the following equation is executed in step S24.

  DFST = (Vn−Va) / (Vb−Va) * 100 (%)

  Following the step S24, it is determined whether or not the flag 1 described above is turned on (step S25). If the determination in step S25 is affirmative, the data stored in the RAM of the display device 54 is as follows. This control routine is terminated after being obtained by mathematical formula (step S26).

  SFTing = SFT, DSFTing = DSFT

  Here, “ing” means storing various data in the RAM for the display device 54. On the other hand, if a negative determination is made in step S25, it is determined whether or not a condition for executing the automatic downshift in the belt type continuously variable transmission 6 is satisfied (step S27). For example, when the gear ratio operation device 53 is not operated, and the vehicle Ve is decelerated at a low vehicle speed without causing a braking request for the vehicle Ve, and the vehicle Ve stops, an automatic downshift, that is, a belt-type continuously variable transmission. A downshift that increases the gear ratio of the machine 6 is executed. This is because this automatic downshift is executed even when the gear ratio selection device 53 is not operated in order to suppress deficiency in driving force when the vehicle Ve starts after the vehicle Ve stops. If the determination in step S27 is affirmative, various data stored in the RAM of the display device 54 are calculated (step S28), and the control routine is terminated. In step S28, the processing of the mathematical formulas (1) to (4) is executed.

  SFTALL = SFT * 100 + DSFT (1)

  SFTALL (i) = SFTALL (i−1) + (SFTALL−SFTALL (i−1)) m (2)

  SFTing = SFTALL (i) / 100 (3)

  DSFTing = SFTALL (i) −SFTing * 100 (4)

  In the above mathematical formula (1), “SFTALL” represents the intermediate gear ratio and each gear stage in terms of the ratio between the gear stages, and the processing of “SFT * 100” represents a predetermined gear stage. This is a process for expressing the ratio between gears. In Formula (2), “SFTALL (i)” is a current value indicating the sum of the gear ratios, and “SFTALL (i−1)” is a previous value indicating the sum of the gear ratios. Where “m” is a coefficient of the annealing process. Further, the above formula (3) is a process for returning the shift speed represented by the ratio to the original fixed shift speed, and the process of the formula (4) is calculated from the sum of the ratios of the shift speeds. This is a process for extracting the intermediate ratio.

  On the other hand, if a negative determination is made in step S27, the data stored in the RAM of the display device 54 is obtained by the following equation (step S29), and this control routine is terminated.

  SFTing = SFTing previous value

  DSFTing = DSFTing previous value

  As described above, according to the control examples of FIGS. 1, 3, and 4, when the gear ratio selection device 53 is operated and the target input rotational speed is changed, or the gear ratio selection device 53 is not operated. When a braking request for the vehicle Ve is generated and the routine is to go through step S7 as in the case where the target input rotational speed of the belt type continuously variable transmission 6 is controlled to be substantially constant, the routine proceeds to step S26, where the target input A predetermined shift speed or a gear ratio between the shift speeds corresponding to the rotational speed is displayed on the display device 54 without being subjected to a smoothing process.

  On the other hand, the gear ratio selection device 53 is not operated and the vehicle Ve is not requested to be braked, and the vehicle proceeds to step S27 via step S14 as in the case where the vehicle travels at a low vehicle speed. If the determination in step S27 is affirmative, the process proceeds to step S28, and the shift speed corresponding to the target input rotation speed and the gear ratio between the shift speeds are smoothed and displayed on the display device 54. Therefore, when the vehicle Ve travels at a low vehicle speed and slips when the wheel 2 gets over a step or the like, even if the vehicle speed slightly changes, the gear ratio displayed on the display device 54 is frequently switched. (Hunting) can be suppressed. Further, in steps S15, S18, S20, and S22, it is possible to make the occupant of the vehicle Ve recognize that the requested target input rotational speed is in the non-permitted region X2.

  By the way, when the gear ratio selection device 53 is operated, for example, a change with time of the target input speed and the actual input speed when downshifting will be described with reference to the time chart of FIG. Before the time t1, the target input rotational speed and the actual input rotational speed are the same, and the downshift operation is executed at the time t1, and the target input rotational speed is higher than the target input rotational speed before the time t1. Yes. On the other hand, since the gear ratio of the belt type continuously variable transmission 6 changes according to the flow rate of the pressure oil in the hydraulic chamber 19, a response delay of the actual input rotational speed is inevitable with respect to the operation of the gear ratio selection device 53. To occur. For example, the actual input rotation speed starts increasing after time t2. On the other hand, in this control example, when calculating the data to be stored in the RAM of the display device 54, the target input rotation speed is used instead of the actual input rotation speed as in steps S16 and S24. For this reason, it is possible to avoid a delay in changing the gear position or the gear ratio displayed on the display device 54 with respect to the operation of the gear ratio selecting device 53, and to eliminate the discomfort of the occupant.

  Here, if the correspondence between the functional means shown in FIG. 1, FIG. 3 and FIG. 4 and the configuration of the present invention is described, the process proceeds to step S25 via step 7, and affirmative in step S25. The routine that executes the process of step S26 after the determination is made corresponds to the first display means of the present invention, and the routine that proceeds to step S28 via steps S14 and S27 is the second display means of the present invention. Steps S15, S18, S20, and S22 correspond to the third display means of the present invention, and steps S26, S28, and S29 correspond to the fourth display means of the present invention. Further, the speed changeable region X1 corresponds to the allowable region of the present invention, and the non-permitted region X2 corresponds to the outside of the allowable region of the present invention. Furthermore, the gear ratio displayed on the display device includes a number indicating each gear, a gear ratio corresponding to each gear, a gear ratio corresponding between the gears, and the like. The “operation of the operation device” of the present invention includes a case where the gear ratio selection device 53 is operated and a case where the gear ratio selection device 53 is not operated. The “vehicle driving state” of the present invention includes vehicle speed, acceleration request, and braking request, and is premised on that the operating device is not operated.

  Further, in FIG. 2 showing the power train of the vehicle Ve, a belt type continuously variable transmission 6 is cited as a continuously variable transmission, but other continuously variable transmissions such as a toroidal continuously variable transmission are provided. It is also possible to apply this invention to a vehicle. This toroidal-type continuously variable transmission is a transmission having an input disk and an output disk having toroidal surfaces, and a power roller in contact with each disk. The input disk is connected to the input rotating member, and the output disk is connected to the output rotating member. Lubricating oil is present on the contact surface between each disk and the power roller. Then, the gear ratio between the input rotating member and the output rotating member is controlled by adjusting the contact radius between the power roller and each disk. Moreover, the capacity | capacitance of the torque transmitted between an input rotation member and an output rotation member is controlled by adjusting the contact surface pressure of each disk and a power roller.

  Furthermore, the continuously variable transmission according to the present invention includes a continuously variable transmission including an electric motor and a planetary gear mechanism having three rotational elements capable of differential rotation. In this case, the first rotation element becomes an input element, the second rotation element becomes an output element, and the third rotation element becomes a reaction force element. Then, an electric motor is connected to the third rotating element, and the speed ratio between the first rotating element and the second rotating element can be changed steplessly (continuously) by controlling the rotation speed of the electric motor. ) It is possible to control. Such a continuously variable transmission having an electric motor and a planetary gear mechanism can be used, for example, in a hybrid vehicle having a plurality of driving force sources.

  As a configuration example of the power train of such a hybrid vehicle, an engine that is a first power source is connected to a first rotating element, and a motor / generator that is a second power source is connected to the second rotating element. Power trains. The continuously variable transmission having the electric motor and the planetary gear mechanism is configured to be able to switch between the automatic transmission mode and the manual transmission mode, and in the manual transmission mode, there is no transmission ratio as intended by the driver. It is possible to configure so that the input rotation speed and the gear ratio of the step transmission can be controlled. As an actuator for controlling the continuously variable transmission, an electric actuator, a pneumatic actuator, or the like can be used in addition to the hydraulic control actuator.

It is a flowchart which shows a part of example of control which can be performed by this invention. It is a conceptual diagram which shows the power train and control system of the vehicle used as the object of the example of control of this invention. It is a flowchart which shows a part of example of control which can be performed by this invention. It is a flowchart which shows a part of example of control which can be performed by this invention. It is a figure which shows an example of the transmission map of the belt-type continuously variable transmission shown by FIG. 3 is a time chart showing changes with time of a target input rotational speed and an actual input rotational speed in the belt-type continuously variable transmission shown in FIG. 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 6 ... Belt type continuously variable transmission, 18 ... Hydraulic control device, 50 ... Shift position selection device, 51 ... Transmission mode selection device, 52 ... Electronic control device, 53 ... Transmission ratio selection device, 54 ... Display device, Ve ... Vehicle .

Claims (3)

It is possible to selectively switch between the target input rotational speed of the continuously variable transmission determined based on the operation of the operating device and the target input rotational speed of the continuously variable transmission determined based on the driving state of the vehicle. The transmission ratio between the input rotation speed and the output rotation speed of the continuously variable transmission is controlled so that the actual input rotation speed of the transmission approaches the selected target input rotation speed, and the continuously variable transmission In a transmission control device for a continuously variable transmission having a display device for displaying a transmission ratio of
When the operation device is operated to change the target input rotation speed, or the operation device is not operated and a vehicle braking request is generated, and the target input rotation speed of the continuously variable transmission is controlled to be substantially constant. If so, first display means for displaying a gear ratio according to the target input rotation speed on the display device;
When the operation device is not operated, a vehicle braking request is not generated, and the target input rotational speed of the continuously variable transmission is increased when traveling at a low vehicle speed, the target input rotation Second display means for smoothing and displaying the gear ratio according to the number on the display device;
A speed change control device for a continuously variable transmission.   When the target input rotational speed requested by the operation of the operating device is outside the allowable range, the target input rotational speed within the allowable range is selected, and the requested target input rotational speed is out of the allowable range. The transmission control device for a continuously variable transmission according to claim 1, further comprising a third display means for displaying the information on the display device.   The transmission control device for a continuously variable transmission according to claim 1 or 2, further comprising fourth display means for displaying a gear ratio corresponding to the target input rotational speed on the display device. .

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