JP4830914B2 - Shift control device for continuously variable transmission - Google Patents

Description

  The present invention relates to a transmission control device for a continuously variable transmission, and more particularly to a transmission control device for a belt-type continuously variable transmission such as a CVT.

  Conventionally, a belt type continuously variable transmission (CVT) is known. In this belt type continuously variable transmission, a belt is wound around a primary pulley on the driving side and a secondary pulley on the driven side having a V-shaped pulley groove, and at the same time the width of the pulley groove of one pulley is increased. By narrowing the width of the pulley groove of each pulley, the belt winding radius (effective diameter) with respect to each pulley is continuously changed to set the transmission ratio steplessly.

  The torque transmitted in this belt-type continuously variable transmission is a torque corresponding to the load acting in the direction in which the belt and pulley are brought into contact with each other. Therefore, the belt is clamped by the pulley so as to apply tension to the belt. ing.

  Further, as described above, the speed change is configured to be performed by enlarging / reducing the width of the pulley groove. Specifically, each pulley is configured by a fixed sheave and a movable sheave. Is shifted by moving it back and forth in the axial direction by a hydraulic actuator provided on the back side thereof.

  In such a continuously variable transmission, the pulley width of the primary pulley is small (the pulley diameter is large), and the pulley width of the secondary pulley is large (the pulley diameter is small). When the speed is higher than the rotation speed, it is called speed increase. When the pulley width of the primary pulley is large (pulley diameter is small) and the pulley width of the secondary pulley is small (pulley diameter is large), the rotation speed of the secondary pulley is primary. A case where the rotational speed is lower than the number of rotations of the pulley is called deceleration.

  In the speed change of the continuously variable transmission having such a configuration, the target input rotational speed NINT of the primary pulley is calculated based on the accelerator opening and the vehicle speed, and the actual input rotational speed of the primary pulley is calculated based on the target input rotational speed NINT. Shift control is performed to match NIN.

  For example, when the traveling load decreases and the vehicle speed increases to increase the engine speed, the target input speed NINT of the primary pulley is set to be low, and the actual input speed NIN of the primary pulley is set to the target value of the primary pulley. Shift control is performed so that the input rotational speed is NINT. Conversely, when the engine rotational speed decreases due to an increase in running resistance, the target input rotational speed NINT of the primary pulley is set to be high, and the actual input rotational speed of the primary pulley is set. Shift control is performed so that the number NIN becomes the target input rotational speed NINT of the primary pulley.

  However, in an operating state in which the gear is shifted up to a gear stage having a small gear ratio, when the accelerator pedal is decelerated, the upshifting is promoted and the engine braking effect may be deteriorated.

In order to eliminate such a problem, at the time of deceleration when the accelerator pedal is released, the gear ratio corresponding to the actual engine speed immediately before the gear shift is held for a certain period of time, and the shift up is prohibited. Therefore, there is one that effectively performs engine braking (see, for example, Patent Document 1).
JP 61-119473 A

  However, in such a conventional transmission control device for a continuously variable transmission, at the time of deceleration at which the accelerator pedal is released, the actual speed ratio according to the actual engine speed immediately before the speed change is maintained for a certain period of time. That is, since the shift control is performed based on the actual input rotational speed NIN of the primary pulley when the accelerator is released, the actual input rotational speed NIN of the primary pulley is lower than the target input rotational speed NINT. Depending on the driving state of the vehicle, the speed change control may be performed on the high speed side as compared with the case where the speed ratio is controlled based on the target input speed NINT.

  Specifically, when the accelerator pedal is suddenly depressed, the target input rotational speed NINT is set high. Therefore, immediately after the accelerator pedal is suddenly depressed, the accelerator pedal is released and deceleration is started. The initial value of the input rotation speed NINT is higher than the actual input rotation speed NIN. For this reason, the shift control is performed so that the actual input rotation speed NIN matches the target input rotation speed NINT on the high rotation side, so that a transient deceleration state is temporarily achieved and the deceleration can be performed smoothly. This will make the driver feel uncomfortable.

  On the other hand, it is conceivable that the shift control is performed based on the target input speed NINT when the accelerator pedal is released, but the above-described case is also applied when the target input speed NINT is higher than the actual input speed NIN. Thus, the shift control is performed so that the actual input rotation speed NIN matches the target input rotation speed NINT on the high rotation side. For this reason, it becomes a transient deceleration state temporarily, and cannot decelerate smoothly, and gives a driver uncomfortable feeling.

  The present invention has been made to solve the conventional problems, and is a continuously variable transmission that can smoothly decelerate at the time of deceleration of the vehicle so that the driver does not feel uncomfortable. An object of the present invention is to provide a transmission control device.

In the continuously variable transmission control device according to the present invention, (1) a target input rotational speed of a continuously variable transmission connected to an internal combustion engine is set based on driving conditions of the vehicle, and the target input rotational speed is set to the target input rotational speed. Deceleration request determination for determining the driver's deceleration request in a transmission control device for a continuously variable transmission that controls the transmission ratio of the continuously variable transmission so that the actual input rotation speed of the continuously variable transmission matches. Means, a target input rotational speed setting means for setting a target input rotational speed based on a driving condition of the vehicle when the deceleration request determination means determines that the deceleration request is required, and the absence of the deceleration request determination start time. The target input rotational speed of the step transmission is compared with the actual input rotational speed, and the input rotational speed on the side where the input rotational speed of the continuously variable transmission becomes lower among the target input rotational speed and the actual input rotational speed. To the initial value of the target input speed And a one and a shift control means for performing shift control by.
With this configuration, when sudden deceleration is performed after sudden acceleration, the gear ratio is not controlled so that the actual input rotational speed matches the target input rotational speed set on the high rotational side as in the prior art. .

  Specifically, when sudden deceleration is performed after rapid acceleration, the initial value of the target input rotational speed at the start of deceleration is set to the high rotational speed side, so the actual input rotational speed is temporarily high after the deceleration starts. Shift control is performed to match the target input rotational speed on the side, and the engine brake is increased. For this reason, when the vehicle starts to decelerate, the vehicle is in a transient decelerating state, and the decelerating cannot be performed smoothly, giving the driver an uncomfortable feeling.

  In the present invention, when there is a deceleration request from the driver, the target input rotational speed of the continuously variable transmission at the start of the deceleration request determination is compared with the actual input rotational speed, and the target input rotational speed and the actual input rotational speed are compared. Since the speed change control is performed by setting the input speed at which the input speed of the continuously variable transmission becomes lower among the speeds to the initial value of the target input speed, the target input speed at the start of deceleration The initial value of the number can be set on the low rotation side.

  For this reason, it is possible to perform speed change control for quickly displacing the actual input rotational speed to the low speed side regardless of the magnitude relationship between the target input rotational speed at the start of deceleration and the actual input rotational speed. As a result, the vehicle can be smoothly decelerated and the driver can be prevented from feeling uncomfortable.

  Further, in the transmission control device for a continuously variable transmission according to the present invention, in (1), (2) the shift control means is configured such that the target input rotational speed and the actual input rotational speed at the start of the determination of the deceleration request. When the deviation is equal to or higher than a preset deviation rotational speed, the shift control is performed based on the actual input rotational speed, and the target input rotational speed and the actual input rotational speed at the start of the determination of the deceleration request When the deviation is less than a preset rotational speed, the shift control is performed based on the target input rotational speed.

  With this configuration, when the deviation between the target input rotational speed at the start of deceleration request determination and the actual input rotational speed is greater than or equal to a preset rotational rotational speed, shift control is performed based on the actual input rotational speed. The actual input rotational speed at the start of deceleration can be set to the initial value of the target input rotational speed, and the target input rotational speed can be set to the low rotational side. As a result, it is possible to perform shift control for quickly displacing the actual input rotational speed to the low speed side.

  Also, when the deviation between the target input speed at the start of the deceleration request determination and the actual input speed is less than the preset deviation speed, the shift control is performed based on the target input speed, so deceleration starts. The initial value of the target input rotation speed at the time can be set to the low rotation side. As a result, it is possible to perform shift control for quickly displacing the actual input rotational speed to the low speed side.

  Further, in the transmission control device for a continuously variable transmission according to the present invention, in (1) and (2), (3) the deceleration request determination means includes an accelerator operation amount sensor that detects an opening degree of an accelerator pedal, It is comprised from what determines the presence or absence of the deceleration request | requirement based on the detection information from an accelerator operation amount sensor.

  With this configuration, it is possible to determine whether or not a driver's shift request is made according to the opening of the accelerator pedal, and thus it is possible to reliably detect the driver's direct deceleration request.

  The present invention can provide a transmission control device for a continuously variable transmission that can smoothly decelerate when the vehicle is decelerated so that the driver does not feel uncomfortable.

Embodiments of a transmission control device for a continuously variable transmission according to the present invention will be described below with reference to the drawings.
FIGS. 1-8 is a figure which shows one Embodiment of the transmission control apparatus of the continuously variable transmission which concerns on this invention.
First, the configuration will be described. In FIG. 1, a power transmission device 1 including a belt type continuously variable transmission 2 provided in a vehicle is suitably employed in, for example, a laterally mounted FF (front engine / front drive) drive vehicle. An engine 3 is provided as an engine.

  The output of the engine 3 is transmitted from the torque converter 4 to the differential gear device 7 via a forward / reverse switching device 5, a belt-type continuously variable transmission (hereinafter simply referred to as CVT) 2, and a reduction gear 6, and left and right drive wheels. 8L and 8R are distributed. That is, the CVT 2 is provided in a power transmission path from the engine 3 to the left and right drive wheels (for example, front wheels) 8L and 8R.

  The torque converter 4 is non-rotating via a one-way clutch with a pump impeller 9p connected to the crankshaft of the engine 3 and a turbine impeller 9t connected to the forward / reverse switching device 5 via the turbine shaft 10. A fixed impeller 9s rotatably supported by the member is provided to transmit power through a fluid.

  Further, between the pump impeller 9p and the turbine impeller 9t, the pump impeller 9p and the turbine impeller 9t are integrally connected so that they can be integrally rotated with each other. Clutch) 11 is provided.

  The forward / reverse switching device 5 is composed of a double pinion type planetary gear device. The turbine shaft 10 of the torque converter 4 is connected to the sun gear 12s, and the input shaft 13 of the CVT 2 is connected to the carrier 12c.

  When the forward clutch 14 disposed between the carrier 12c and the sun gear 12s is engaged, the forward / reverse switching device 5 is integrally rotated to directly connect the turbine shaft 10 to the input shaft 13 and move forward. The driving force is transmitted to the driving wheels 8L and 8R.

  When the reverse brake 16 disposed between the ring gear 12r and the housing 15 is engaged and the forward clutch 14 is released, the input shaft 13 is rotated in the reverse direction with respect to the turbine shaft 10 to move in the reverse direction. Is transmitted to the drive wheels 8L and 8R.

  On the other hand, the CVT 2 is formed in each of the primary pulley 17 having a variable effective diameter provided in the input shaft 13, the secondary pulley 19 having a variable effective diameter provided in the output shaft 18, and the primary pulley 17 and the secondary pulley 19. And a transmission belt 20 wound around the V-groove, and the transmission belt 20 functioning as a power transmission member is subjected to a frictional force between inner walls of the V-grooves of the primary pulley 17 and the secondary pulley 19. Power transmission is performed.

  Specifically, the primary pulley 17 includes a movable sheave 17A and a fixed sheave 17B that are opposed to each other and form a V-groove by opposing surfaces, and the transmission belt 20 is wound around the V-groove of the movable sheave 17A and the fixed sheave 17B. It is hung.

  The secondary pulley 19 includes a movable sheave 19A and a fixed sheave 19B that are opposed to each other and form a V-groove by an opposing surface. A transmission belt 20 is wound around the V-groove of the movable sheave 19A and the fixed sheave 19B. Yes.

  The primary pulley 17 and the secondary pulley 19 have respective V-groove widths, that is, an input-side hydraulic cylinder 17a formed on the movable sheave 17A for changing the engagement diameter of the transmission belt 20, and an output-side hydraulic cylinder formed on the movable sheave 19A. 19a, and the flow rate of the hydraulic oil supplied to or discharged from the input side hydraulic cylinder 17a of the movable sheave 17A is controlled by a shift control valve device 32 in the hydraulic control circuit 31 (see FIG. 3). As a result, the V-groove widths of the primary pulley 17 and the secondary pulley 19 are changed to change the engagement diameter (effective diameter) of the transmission belt 20, and the gear ratio γ (= actual input rotational speed NIN / actual output rotational speed). NOUT) can be continuously changed.

  The hydraulic pressure PB in the output side hydraulic cylinder 19a of the movable sheave 19A corresponds to the clamping pressure of the secondary pulley 19 against the transmission belt 20 and the tension of the transmission belt 20, respectively. Since it is closely related to the pressing force of the primary pulley 17 and the secondary pulley 19 of the transmission belt 20 against the inner wall surface of the V-groove, it can also be called a belt tension control pressure, a belt clamping pressure control pressure, or a belt pressing force control pressure. In addition, pressure is regulated by the clamping pressure control valve 33 in the hydraulic control circuit 31 so that the transmission belt 20 does not slip.

  2 and 3 are diagrams showing an example of the hydraulic control circuit 31. FIG. 2 shows a circuit related to the adjustment operation of the belt tension control pressure, and FIG. 3 shows a circuit related to the gear ratio control. In FIG. 2, the hydraulic oil returned to the oil tank 34 is directly connected to the engine 3 and driven to rotate by the engine 3. For example, the hydraulic oil is pumped by a gear-type hydraulic pump 35 and is not shown by a line pressure regulating valve (not shown). After the pressure is adjusted to the line pressure PL, the pressure is supplied to the linear solenoid valve 36 and the clamping pressure control valve 33 as a source pressure.

  The linear solenoid valve 36 is continuously controlled by the excitation current output from the electronic control unit 100 (see FIG. 4), so that it corresponds to the excitation current from the hydraulic pressure of the hydraulic oil supplied from the hydraulic pump 35. A control pressure PS having a magnitude is generated and supplied to the clamping pressure control valve 33.

  The clamping pressure control valve 33 generates a hydraulic pressure PB that is increased as the control pressure PS increases, and supplies the hydraulic pressure PB to the output hydraulic cylinder 19a of the movable sheave 19A, so that the transmission belt 20 does not slip. Thus, the clamping pressure on the transmission belt 20, that is, the tension of the transmission belt 20 is made small. As the hydraulic pressure PB increases, the belt clamping pressure, that is, the friction force between the primary pulley 17 and the secondary pulley 19 and the transmission belt 20 increases.

  The linear solenoid valve 36 is provided with an oil chamber 36a to which the control pressure PS output from the cutback valve 37 is supplied when the cutback valve 37 is turned on, while the linear solenoid valve 36 is turned off when the cutback valve 37 is turned off. The supply of the control pressure PS to the oil chamber 36a is cut off and the oil chamber 38a is opened to the atmosphere. When the cutback valve 37 is turned on, the control pressure PS characteristic is switched to a lower pressure than when it is off. It is supposed to be.

  Further, the cutback valve 37 is switched on when a signal pressure PON is supplied from an electromagnetic valve (not shown) when the lockup clutch 11 of the torque converter 4 is turned on (engaged).

  In FIG. 3, the shift control valve device 32 controls the shift speed in the up direction by supplying the hydraulic oil of the line pressure PL exclusively to the input side hydraulic cylinder 17a of the movable sheave 17A and controlling the flow rate of the hydraulic oil. The up-shift control valve 41 and the down-shift control valve 42 that controls the shift speed in the down direction by controlling the flow rate of hydraulic fluid discharged from the input side hydraulic cylinder 17a of the movable sheave 17A.

  The upshift control valve 41 has an input port 41a that communicates with a line oil passage L that guides the line pressure PL, a spool valve 43 that opens and closes between the line oil passage L and the input side hydraulic cylinder 17a, and a spool valve 43 And a control oil chamber 46 that guides the control pressure output from the up-side electromagnetic valve 45.

  The down shift control valve 42 includes a spool valve 47 that opens and closes between the drain oil passage D and the input side hydraulic cylinder 17a, a spring 48 that biases the spool valve 47 in the valve closing direction, and a down side solenoid valve 49. And a control oil chamber 50 for guiding a control pressure output from the control oil chamber.

  The up-side solenoid valve 45 and the down-side solenoid valve 49 are duty-driven by the electronic control unit 100 to supply continuously changing control pressure to the control oil chamber 46 and the control oil chamber 50, and the transmission ratio of the CVT 2. γ is continuously changed to the up side (side where the gear ratio decreases) or down (side where the gear ratio increases).

  A pressure regulating valve 51 is connected to the input port 42a of the downshift control valve 42. In the pressure regulating valve 51, an input port 54 to which a line pressure PL is supplied is formed on the front side of the piston 52 pressed by a spring 53, and an output port 55 communicated with the front side and the back side of the piston 52. The output port 55 communicates with the input port 42a of the downshift control valve 42.

  Further, the line pressure PL is supplied to the input port 54 through a double orifice 56 having a small opening area. That is, the pressure regulating valve 51 regulates the line pressure PL so as to obtain a hydraulic pressure having a pressure obtained by subtracting the elastic force of the spring 53 from the line pressure PL, and the regulated line pressure PL is output to the output port 55, that is, the downshift. It is configured to occur at the input port 42a of the control valve 42.

  FIG. 4 shows an electronic control device 100 provided in the vehicle of the present embodiment. The electronic control device 100 includes a shift lever operation position sensor 102, an accelerator operation amount sensor 103, an engine speed sensor 104, a throttle sensor 105, a primary speed sensor 106, a secondary speed sensor 107, a pressure sensor 108, and a clamping pressure control. A valve 33 and a shift control valve device 32 are connected.

  The shift lever operation position sensor 102 detects the operation position Psh of the shift lever 101 provided in the vehicle interior and outputs a signal corresponding to the operation position Psh to the electronic control unit 100.

  The accelerator operation amount sensor 103 detects the opening degree pap of the accelerator pedal 63 (see FIG. 1) and outputs a signal corresponding to the accelerator opening degree pap to the electronic control unit 100.

The electronic control unit 100 determines whether or not the driver has requested deceleration based on a signal corresponding to the accelerator opening pap output from the accelerator operation amount sensor 103. When the corresponding signal is equal to or smaller than the threshold value, it is determined that the request is for deceleration. In the present embodiment, the electronic control unit 100 and the accelerator operation amount sensor 103 constitute a deceleration request determination unit.
The engine speed sensor 104 detects the speed Ne of the engine 3 and outputs a signal corresponding to the engine speed Ne to the electronic control unit 100.

  The throttle sensor 105 detects the opening degree θth of the throttle valve 62 (see FIG. 1) driven by the throttle actuator 61 and outputs a signal corresponding to the throttle opening degree θth to the electronic control unit 100.

  The primary rotational speed sensor 106 detects the actual rotational speed of the input shaft 13 of the primary pulley 17 and outputs a signal corresponding to the actual input rotational speed NIN of the primary pulley 17 to the electronic control unit 100. ing.

  The secondary rotation speed sensor 107 outputs a signal corresponding to the actual rotation speed NOUT of the secondary pulley 19 to the electronic control device 100 by detecting the rotation speed of the output shaft 18 of the secondary pulley 19. The electronic control unit 100 detects the vehicle speed based on the actual output rotational speed NOUT of the secondary rotational speed sensor 107.

  The pressure sensor 108 detects an internal pressure of the output side hydraulic cylinder 19a of the movable sheave 19A, that is, an actual belt clamping pressure control pressure, and outputs a hydraulic pressure signal PB to the electronic control unit 100.

  The electronic control unit 100 includes a microcomputer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), an input / output interface, and the like, and uses a temporary storage function of the RAM. However, by performing signal processing in accordance with a shift control program stored in advance in the ROM, the shift control of the CVT 2 is executed so as to obtain a suitable feeling of deceleration and fuel consumption.

  With reference to FIG. 5, description will be given based on the shift map of the shift mode of CVT2. The shift map shown in FIG. 5 is a map in which the horizontal axis is the vehicle speed, the vertical axis is the target input rotational speed of the primary pulley 17, and the parameter is the accelerator opening, and this map is stored in the ROM of the electronic control unit 100. ing.

  As shown in FIG. 5, with the accelerator opening as a parameter, the vehicle speed and the target input of the primary pulley 17 for each accelerator opening within the range from the minimum gear ratio (γmin) to the maximum state (γmax) of CVT2. A relationship with the rotational speed NINT (target value) is defined.

  This shift map determines the target engine output required by the driver from the accelerator opening and the vehicle speed, and the primary pulley 17 determined so that the determined target engine output can be realized on the optimum fuel consumption line of the engine 3. The target input rotational speed NINT is set so that the speed ratio is changed from the minimum state to the maximum state as the accelerator opening increases.

  In the shift control of the CVT 2, the target input rotation speed NINT of the primary pulley 17 is set so that an optimal gear ratio and shift speed can be realized based on information on the accelerator opening and the vehicle speed.

  At this time, the electronic control device 100 is connected to the shift control valve device 32 and the clamping pressure control valve 33 so that the target input rotation speed NINT of the primary pulley 17 and the actual input rotation speed NIN obtained from the primary rotation speed sensor 106 coincide with each other. A control signal is output to optimize the gear ratio, and control is performed so that the actual input rotational speed NIN obtained from the primary rotational speed sensor 106 becomes the target input rotational speed NINT. In the present embodiment, the electronic control unit 100 constitutes a target input rotation speed setting unit and a shift control unit.

  On the other hand, the electronic control unit 100 determines whether or not the value is in accordance with the driver's deceleration request based on the signal indicating the accelerator opening degree pap from the accelerator operation amount sensor 103. The determination of the deceleration request is made when there is a driver's deceleration request when a signal indicating the accelerator opening degree pap is equal to or smaller than a predetermined threshold, for example, when a corresponding signal is input when the accelerator pedal 63 is off. To do.

  When there is a deceleration request from the driver, the electronic control unit 100 determines the target engine output required by the driver based on the accelerator opening and the vehicle speed, that is, based on the driving state of the vehicle. The target input rotational speed NINT of the primary pulley 17 is set so that the engine output can be realized on the optimum fuel consumption line of the engine 3 based on the shift map shown in FIG.

  Then, the target input rotational speed NINT of the primary pulley 17 at the time when the accelerator pedal 63 is turned off, that is, when the deceleration request determination start time is compared with the actual input rotational speed NIN, and the target input rotational speed NINT and the actual input rotational speed are compared. Of the NIN, the input rotational speed on the side where the input rotational speed of the primary pulley 17 is lowered is set to the initial value of the target input rotational speed NINT to perform the shift control.

  If the deviation between the target input speed NINT and the actual input speed NIN is greater than or equal to the set value, the initial value of the target input speed NIN is set to the input speed NIN, and the target input speed NINT and the actual input speed are set. If the deviation of the rotational speed NIN is less than or equal to the set value, the initial value of the target input rotational speed is set to the target input rotational speed NINT.

  Next, the shift control processing of the present embodiment is based on the flowchart shown in FIG. 6 and the timing chart showing the transition of the target input rotational speed of the primary pulley 17 and the actual input rotational speed shown in FIG. explain.

  The flowchart in FIG. 6 is a shift control program stored in the ROM of the electronic control device 100, and this shift control program is executed by the CPU.

  First, it is determined whether or not there is a deceleration request (step S1). In this process, the CPU determines that there is a deceleration request when the accelerator pedal 63 is turned off based on detection information from the accelerator operation amount sensor 103. That is, in this embodiment, since it is determined that there is a deceleration request when the accelerator pedal 63 is turned off, the time point when the accelerator pedal 63 is turned off is the determination start point of the deceleration request.

  Next, the target input rotational speed NINT is calculated based on the vehicle speed and the accelerator opening degree pap, that is, based on the driving state of the vehicle (step S2). In this process, the CPU of the electronic control device 100 calculates the basic target input rotational speed NINC and the target input rotational speed NINT based on the vehicle speed and the accelerator opening degree pap.

  Specifically, using the shift map shown in FIG. 5, the basic target input is based on the signal corresponding to the accelerator opening pap output from the accelerator operation amount sensor 103 and the secondary rotation speed sensor 107 and the vehicle speed signal at that time. A target rotational speed NINT is obtained by setting the rotational speed NINC and subjecting the basic target input rotational speed NINC to a first-order lag smoothing process. This target input rotation speed NINT can be calculated by the following equation (1).

NINT (i) = NINT (i−1) + K1 × {NINC (i) −NINT (i−1)} + K2 (1)
However, (i) means the (i) -th period in the execution period of the control routine, that is, this time, and (i-1) means the previous time. In the above equation (1), “K1” is an annealing constant, and “K2” is a feedback coefficient.

  In this way, the target input speed NINT having an inclination is set until the basic target input speed NINC is reached when deceleration is started. Therefore, the basic input rotation speed in the present embodiment is the basic input rotation speed NINT at which the first-order lag smoothing process is performed.

  Next, the target input rotational speed NINT at the start of deceleration is compared with the actual input rotational speed NIN of the primary pulley 17 (step S3), and the deviation rotational speed between the target input rotational speed NINT and the actual input rotational speed NIN is set to a set value N. In the case of (Nrpm) or more, the initial value of the target input speed is set to the input speed NIN (step S4), and the deviation speed between the target input speed NINT and the actual input speed NIN is less than the set value N or If they are the same, the initial value of the target input speed is set to the target input speed NINT (step S5). The initial value is the target input rotational speed at the start of deceleration control (when the accelerator pedal 63 is off).

  Next, the transition of the target input rotational speed of the primary pulley 17 and the actual input rotational speed will be described with reference to FIGS.

  As shown in FIG. 7, in the acceleration control in which the accelerator pedal 63 is depressed at a predetermined opening for a predetermined time, the target input rotational speed NINT is set to be high when the accelerator pedal 63 is depressed.

  At this time, the control signal is output from the electronic control unit 100 to the transmission control valve device 32 and the clamping pressure control valve 33 to optimize the transmission ratio, and the actual input of the primary pulley 17 obtained from the primary rotation speed sensor 106 is obtained. Shift control is performed so that the rotational speed NIN becomes the target input rotational speed NINT.

  Next, when the accelerator pedal 63 is turned off, the target input rotational speed NINT is set to be low. At this time, the target input rotational speed NINT is compared with the actual input rotational speed NIN.

  When acceleration control is performed for a certain time, since the deviation rotational speed between the target input rotational speed NINT and the actual input rotational speed NIN is smaller than the set value N, the initial value of the target input rotational speed NINT is set to the target input rotational speed. Shift control is performed by setting to NINT.

On the other hand, as shown in FIG. 8, when the accelerator pedal 63 is suddenly depressed and then released rapidly, the target input rotational speed NINT is set to be high when the accelerator pedal 63 is depressed. However, before the actual input rotational speed NIN matches the target input rotational speed NINT, the shift to the deceleration control is performed.
However, since the initial value Y of the target input speed NINT is set high during the deceleration rotation, if the shift control is performed so that the actual input speed NIN matches the target input speed NINT as it is, as indicated by NINA. Shift control is performed such that the actual input rotational speed NINA is increased. For this reason, as shown by V, a large engine brake occurs, resulting in a transient deceleration state, which gives the driver an uncomfortable feeling.

  In FIG. 8, since the deviation rotational speed between the target input rotational speed NINT and the actual input rotational speed NIN when the accelerator pedal 63 is off is equal to or greater than the set value N, the initial value of the target input rotational speed NINT is represented by Y1. Set to the actual input speed NIN. The first-order lag smoothing process of the target input rotational speed NINT at this time can be executed by changing the smoothing constant “K1” in the above equation (1).

  Therefore, the shift control is performed so that the actual input rotational speed NINA coincides with the optimum target input rotational speed NINT when sudden deceleration is performed after the rapid acceleration. For this reason, as shown by V1, it can decelerate smoothly and it can prevent giving a driver uncomfortable feeling.

  As described above, in the present embodiment, the target input rotational speed NINT of the primary pulley 17 when the accelerator pedal 63 is turned off is compared with the actual input rotational speed NIN of the primary pulley 17, and the target input rotational speed NINT and the actual input rotational speed are compared. Since the input rotational speed on the side where the input rotational speed of the primary pulley 17 is reduced among the rotational speeds NIN is set to the initial value of the target input rotational speed NINT, when performing rapid deceleration after rapid acceleration, Thus, it is possible to prevent the gear ratio from being controlled so that the actual input rotational speed NIN of the primary pulley 17 matches the target input rotational speed NINT set on the high rotational side.

  Therefore, regardless of the magnitude relationship between the target input rotational speed NINT at the start of deceleration and the actual input rotational speed NIN, it is possible to perform shift control that quickly displaces the actual input rotational speed NIN to the low speed side. As a result, a transitional deceleration state after the start of deceleration can be prevented, the deceleration can be performed smoothly, and the driver can be prevented from feeling uncomfortable.

  Further, in the present embodiment, when the deviation between the target input rotational speed NINT at the start of the deceleration request and the actual input rotational speed NIN is greater than or equal to a set value, shift control is performed based on the actual input rotational speed NIN. Therefore, the actual input rotation speed at the time of starting deceleration can be set to the initial value of the target input rotation speed NINT, and the target input rotation speed NINT can be set to the low rotation side. As a result, it is possible to perform shift control for quickly displacing the actual input rotational speed NIN to the low speed side.

  Further, when the deviation between the target input speed NINT at the start of the deceleration request and the actual input speed NINT is less than the set value, the shift control is performed based on the target input speed NINT. The initial value of the input rotation speed NINT can be set to the low rotation side. As a result, it is possible to perform shift control for quickly displacing the actual input rotational speed NIN to the low speed side.

  In the present embodiment, the electronic control unit 100 determines whether or not there is a deceleration request based on the detection information from the accelerator operation amount sensor 103 that detects the opening degree of the accelerator pedal 63. Therefore, the opening degree of the accelerator pedal 63 is determined. Accordingly, it is possible to determine whether or not a driver's shift request is made, and it is possible to reliably detect the driver's direct deceleration request.

  In the present embodiment, as means for determining the driver's deceleration request, the accelerator operation amount sensor 103 detects the opening degree pap of the accelerator pedal 63, and when the accelerator pedal 63 is turned off, there is a deceleration request. However, the present invention is not limited to this, and the throttle sensor 105 detects the opening degree θth of the throttle valve 62, and when the throttle valve 62 is fully closed, it is determined that the deceleration request is made. good.

  In addition, the embodiment disclosed this time is illustrative in all respects and is not limited to this embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

  As described above, the speed change control device for a continuously variable transmission according to the present invention can smoothly decelerate when the vehicle decelerates so that the driver does not feel uncomfortable. And is useful as a shift control device for a belt-type continuously variable transmission such as a CVT.

1 is a diagram showing an embodiment of a transmission control device for a continuously variable transmission according to the present invention, and is a schematic configuration diagram of a vehicle power transmission device including the continuously variable transmission. It is a figure which shows the hydraulic control circuit of one Embodiment of the transmission control apparatus of the continuously variable transmission which concerns on this invention, and is a figure which shows the part relevant to belt tension control. It is a figure which shows the hydraulic control circuit of one Embodiment of the transmission control apparatus of the continuously variable transmission which concerns on this invention, and is a figure which shows the part relevant to gear ratio control. It is a figure which shows the circuit structure of one Embodiment of the transmission control apparatus of the continuously variable transmission which concerns on this invention. It is a figure which shows the transmission map of one Embodiment of the transmission control apparatus of the continuously variable transmission which concerns on this invention. It is a figure which shows the flowchart of the transmission control process of one Embodiment of the transmission control apparatus of the continuously variable transmission which concerns on this invention. 3 is a timing chart showing a transition of a target input rotational speed and an actual input rotational speed during normal acceleration / deceleration in an embodiment of a transmission control device for a continuously variable transmission according to the present invention. 3 is a timing chart showing a transition of a target input rotational speed and an actual input rotational speed at the time of sudden acceleration / deceleration in an embodiment of a speed change control device for a continuously variable transmission according to the present invention.

Explanation of symbols

2 CVT (continuously variable transmission)
3 Engine (Internal combustion engine)
100 Electronic control unit (deceleration request determination means, target input rotation speed setting means, shift control means)
103 Accelerator operation amount sensor (deceleration request determination means)

Claims (3)

A target input rotational speed of a continuously variable transmission connected to an internal combustion engine is set based on a driving condition of the vehicle, and the continuously variable transmission is made to match the actual input rotational speed of the continuously variable transmission with the target input rotational speed. In a transmission control device for a continuously variable transmission that controls a transmission ratio of a transmission,
Deceleration request determination means for determining a deceleration request of the driver;
Target input rotation speed setting means for setting a target input rotation speed based on the driving condition of the vehicle when the deceleration request determination means determines that it is a deceleration request;
The target input rotational speed of the continuously variable transmission at the start of determination of the deceleration request is compared with the actual input rotational speed, and the target input rotational speed and the actual input rotational speed are compared with each other. A speed change control device for a continuously variable transmission, comprising: a speed change control means for performing speed change control by setting an input speed at which the input speed becomes lower to an initial value of the target input speed. The shift control means shifts based on the actual input rotational speed when the deviation between the target input rotational speed at the start of the deceleration request determination and the actual input rotational speed is equal to or greater than a preset rotational rotational speed. Control
When the deviation between the target input rotation speed at the start of the deceleration request determination and the actual input rotation speed is less than a preset deviation rotation speed, shift control is performed based on the target input rotation speed. The speed change control device for a continuously variable transmission according to claim 1. The deceleration request determining means includes an accelerator operation amount sensor for detecting an opening degree of an accelerator pedal, and determines whether or not there is a deceleration request based on detection information from the accelerator operation amount sensor. The transmission control device for a continuously variable transmission according to claim 2.

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