JP6752506B2 - Control device for continuously variable transmission for vehicles - Google Patents

Description

The present invention relates to a control device for a continuously variable transmission mechanism for a vehicle, which is arranged between an engine and a drive wheel and includes a primary pulley, a secondary pulley and a belt.

Conventionally, the belt capacity is increased based on the release of the accelerator pedal. As a result, when the brake pedal is depressed after the accelerator pedal is released, the control of the continuously variable transmission for vehicles that prevents the belt capacity from being insufficient with respect to the input torque from the drive wheels to the belt and prevents the belt from slipping. The device is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 11-0827707

However, in the conventional device, when the belt capacity of the secondary pulley is increased based on the release of the accelerator pedal, the capacity balance of both pulleys is lost, so that an unintended shift occurs. Therefore, in order to suppress unintended shifting, it is necessary to increase the belt capacity of the primary pulley as well as the belt capacity of the secondary pulley.
At this time, due to hydraulic pressure variation or operation delay, the hydraulic pressure supply to the secondary pulley may be delayed, and the increase in the belt capacity of the secondary pulley may be delayed. In this case, the difference in belt capacity between the two pulleys is reduced and an upshift occurs. This also occurs when the belt capacity of the primary pulley increases faster. Further, even in the form in which both pulleys are controlled by electric control instead of hydraulic pressure, the difference in belt capacity may be reduced due to the operation delay.

As described above, when the belt capacities of both pulleys are increased in order to suppress belt slippage and unintended shifting based on the release of the accelerator pedal, an unintended upshift may occur. Due to this upshift, the CVT input speed is lowered, that is, the engine speed is lowered, so that the lockup clutch arranged between the engine and the variator is released in order to prevent the engine stall. Therefore, there is a problem that the fuel cut cannot be performed and the fuel consumption cannot be improved in the subsequent coast running.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for a continuously variable transmission mechanism for a vehicle, which improves fuel efficiency by expanding a driving scene in which fuel cutting can be performed during coastal driving. To do.

In order to achieve the above object, the present invention includes a continuously variable transmission mechanism, a torque converter, and control means.
The continuously variable transmission mechanism is arranged between the engine and the drive wheels and includes a primary pulley, a secondary pulley and a belt.
The torque converter is provided between the engine and the continuously variable transmission mechanism and includes a lockup clutch whose engagement / release is controlled.
The control means controls the belt capacity when the pulley thrust that presses the belt by the primary actual pressure supplied to the primary pulley and the secondary actual pressure supplied to the secondary pulley is called the belt capacity.
A control device for a vehicle continuously variable transmission mechanism, the control means during coasting by the accelerator releasing operation to the accelerator opening becomes zero, the belt capacity at the secondary pulley, CVT accelerator opening is at zero The input torque to is increased above the minimum value of the belt capacity required to prevent the belt from slipping.
The belt capacity of the primary pulley is increased so as to suppress the change in the gear ratio due to the increase of the belt capacity of the secondary pulley.
When increasing the belt capacity in the primary pulley and the secondary pulley, the increase in the belt capacity in the primary pulley is slower than the increase in the belt capacity in the secondary pulley.

Thus, during coasting by the accelerator releasing operation to the accelerator opening is zero, because the belt capacity at the secondary pulley, the accelerator opening with respect to the input torque to the continuously variable transmission mechanism at zero, belt slippage does not occur It can be increased above the minimum required belt capacity. The belt capacity of the primary pulley is increased so as to suppress the change in the gear ratio due to the increase of the belt capacity of the secondary pulley. Then, when increasing the belt capacity in both pulleys, the increase in the belt capacity in the primary pulley is slower than the increase in the belt capacity in the secondary pulley.
That is, even if the continuously variable transmission mechanism varies or delays in operation while the belt capacity is increasing, the difference in belt capacity between the two pulleys keeps the relationship (belt capacity in the secondary pulley)> (belt capacity in the primary pulley). It will be secured. By securing the belt capacity difference in this way, it is possible to prevent the continuously variable transmission mechanism from shifting in the upshift direction when the belt capacity is increased. This upshift prevention suppresses the release of the lockup clutch due to the decrease in engine speed, and expands the driving scene in which the engine can be fuel-cut.
As a result, fuel efficiency can be improved by expanding the driving scene in which fuel cutting can be performed during coastal driving.

FIG. 3 is an overall configuration diagram showing an engine vehicle equipped with a continuously variable transmission with an auxiliary transmission to which the control device of the first embodiment is applied. It is a block diagram which shows the internal structure of the transmission controller of Example 1. FIG. It is a shift map diagram which shows an example of the shift map stored in the storage device of the transmission controller of Example 1. FIG. It is a flowchart which shows the flow of the pulley pressure control processing at the time of coast running executed by the transmission controller of Example 1. Accelerator opening, brake, SEC indicated pressure, SEC actual pressure, PRI indicated pressure, PRI actual pressure, target gear ratio, actual gear ratio, target balance thrust ratio, actual balance, which represent pulley pressure control during coast driving in the comparative example. It is a time chart which shows each characteristic of a thrust ratio. Accelerator opening, brake, SEC indicated pressure, SEC actual pressure, PRI indicated pressure, PRI actual pressure, target gear ratio, actual gear ratio, target balance thrust ratio, actual, which represent pulley pressure control during coast running in Example 1. It is a time chart which shows each characteristic of a balance thrust ratio. It is a flowchart which shows the flow of the pulley pressure control processing at the time of coast running executed by the transmission controller of Example 2. Accelerator opening, brake, SEC indicated pressure, SEC actual pressure, PRI indicated pressure, PRI actual pressure, target gear ratio, actual gear ratio, target balance thrust ratio, actual, which represent pulley pressure control during coast running in Example 2. It is a time chart which shows each characteristic of a balance thrust ratio. It is a flowchart which shows the flow of the pulley pressure control processing at the time of coast running executed by the transmission controller of Example 3. Accelerator opening, brake, SEC indicated pressure, SEC actual pressure, PRI indicated pressure, PRI actual pressure, target gear ratio, actual gear ratio, target balance thrust ratio, actual, which represent pulley pressure control during coast running in Example 3. It is a time chart which shows each characteristic of a balance thrust ratio.

Hereinafter, the best mode for realizing the control device for the continuously variable transmission mechanism for a vehicle of the present invention will be described with reference to Examples 1 to 3 shown in the drawings.

First, the configuration will be described.
The control device in the first embodiment is applied to an engine vehicle equipped with a transmission called a continuously variable transmission with an auxiliary transmission. Hereinafter, the configuration of the control device for the engine vehicle variator in the first embodiment will be described separately for "overall system configuration", "shift control configuration based on the shift map", and "pulley pressure control processing configuration during coast running".

[Overall system configuration]
FIG. 1 shows the overall configuration of an engine vehicle equipped with a continuously variable transmission with an auxiliary transmission to which the control device of the first embodiment is applied, and FIG. 2 shows an internal configuration of a transmission controller. Hereinafter, the overall system configuration will be described with reference to FIGS. 1 and 2.
In the following description, the "gear ratio" of a certain transmission mechanism is a value obtained by dividing the input rotation speed of the transmission mechanism by the output rotation speed of the transmission mechanism. Further, the "lowest gear ratio" means the maximum gear ratio of the gear shifting mechanism, and the "highest gear ratio" means the minimum gear ratio of the gear shifting mechanism.

The engine vehicle shown in FIG. 1 includes an engine 1 having a starter motor 15 for starting an engine as a traveling drive source. The output rotation of the engine 1 is a torque converter 2 having a lockup clutch 9, a reduction gear pair 3, a continuously variable transmission 4 with an auxiliary transmission (hereinafter referred to as "automatic transmission 4"), a final gear pair 5, and an end. It is transmitted to the drive wheels 7 via the speed reducing device 6. The final gear pair 5 is provided with a parking mechanism 8 that mechanically locks the output shaft of the automatic transmission 4 so that it cannot rotate when parked. As a hydraulic pressure source, a mechanical oil pump 10 driven by the power of the engine 1 and an electric oil pump 50 driven by the power of the motor 51 are provided. Then, the hydraulic control circuit 11 that regulates the discharge pressure from the mechanical oil pump 10 or the electric oil pump 50 and supplies it to each part of the automatic transmission 4, the transmission controller 12 that controls the hydraulic control circuit 11, and the integrated controller. 13 and an engine controller 14 are provided. Hereinafter, each configuration will be described.

The automatic transmission 4 includes a belt-type continuously variable transmission mechanism (hereinafter referred to as "variator 20") and an auxiliary transmission mechanism 30 provided in series with the variator 20. Here, "provided in series" means that the variator 20 and the auxiliary transmission mechanism 30 are provided in series in the power transmission path. The auxiliary transmission mechanism 30 may be directly connected to the output shaft of the variator 20 as in this example, or may be connected via another transmission or power transmission mechanism (for example, a gear train).

The variator 20 is a belt-type continuously variable transmission mechanism including a primary pulley 21, a secondary pulley 22, and a V-belt 23 that is hung between the pulleys 21 and 22. The pulleys 21 and 22 are arranged with the fixed conical plate and the sheave surface facing the fixed conical plate, respectively, and form a V-groove between the fixed conical plate and the movable conical plate. A primary hydraulic cylinder 23a and a secondary hydraulic cylinder 23b provided on the back surface of the plate to displace the movable conical plate in the axial direction are provided. When the hydraulic pressure supplied to the primary hydraulic cylinder 23a and the secondary hydraulic cylinder 23b is adjusted, the width of the V groove changes, the contact radius between the V belt 23 and the pulleys 21 and 22 changes, and there is no gear ratio of the variator 20. It changes in stages.

The auxiliary transmission mechanism 30 is a transmission mechanism having two forward speeds and one reverse speed. The auxiliary transmission mechanism 30 is connected to a rabbit-type planetary gear mechanism 31 that connects two planetary gear carriers and a plurality of rotating elements constituting the rabbit-type planetary gear mechanism 31, and a plurality of frictions that change their linkage states. It includes fastening elements (low brake 32, high clutch 33, reverse brake 34).

The speed change stage of the auxiliary transmission mechanism 30 is changed by adjusting the hydraulic pressure supplied to the friction fastening elements 32 to 34 and changing the fastening / releasing state of the friction fastening elements 32 to 34. For example, if the low brake 32 is engaged and the high clutch 33 and the reverse brake 34 are released, the shift stage of the auxiliary transmission mechanism 30 becomes the forward 1st gear (hereinafter referred to as "low speed mode"). When the high clutch 33 is engaged and the low brake 32 and the reverse brake 34 are released, the shift stage of the auxiliary transmission mechanism 30 becomes the forward second gear (hereinafter referred to as "high speed mode") having a gear ratio smaller than that of the first gear. .. Further, if the reverse brake 34 is fastened and the low brake 32 and the high clutch 33 are released, the shift stage of the auxiliary transmission mechanism 30 becomes the reverse gear. If all of the low brake 32, the high clutch 33, and the reverse brake 34 of the auxiliary transmission mechanism 30 are released, the driving force transmission path to the drive wheels 7 is cut off. The low brake 32 and the high clutch 33 are hereinafter referred to as "forward clutch Fwd / C".

As shown in FIG. 2, the transmission controller 12 includes a CPU 121, a storage device 122 composed of a RAM / ROM, an input interface 123, an output interface 124, and a bus 125 connecting them to each other. .. The transmission controller 12 controls the gear ratio of the variator 20 and replaces a plurality of friction engaging elements (low brake 32, high clutch 33, reverse brake 34) of the auxiliary transmission mechanism 30 to change a predetermined shift stage. Achieve.

The input interface 123 includes an output signal of the accelerator opening sensor 41 that detects the depression opening of the accelerator pedal (hereinafter referred to as "accelerator opening APO"), and an input rotation speed of the automatic transmission 4 (= primary pulley rotation). The output signal of the rotation speed sensor 42 that detects the speed (hereinafter referred to as "primary rotation speed Npri"), the output signal of the vehicle speed sensor 43 that detects the traveling speed of the vehicle (hereinafter referred to as "vehicle speed VSP"), and automatic transmission. The output signal of the line pressure sensor 44 that detects the line pressure of the machine 4 (hereinafter referred to as "line pressure PL"), the output signal of the inhibitor switch 45 that detects the position of the select lever, and the brake switch 46 that detects the braking state. Output signals, etc. are input. Further, an output signal of the CVT oil temperature sensor 48 for detecting the temperature of the transmission hydraulic oil is input to the input interface 123.

The storage device 122 stores a shift control program for the automatic transmission 4 and a shift map (FIG. 3) used in the shift control program. The CPU 121 reads and executes a shift control program stored in the storage device 122, performs various arithmetic processes on various signals input via the input interface 123 to generate a shift control signal, and generates a shift control signal. The control signal is output to the hydraulic control circuit 11 via the output interface 124. Various values used by the CPU 121 in the calculation process and the calculation results are appropriately stored in the storage device 122.

The hydraulic control circuit 11 is composed of a plurality of flow paths and a plurality of hydraulic control valves. The hydraulic pressure control circuit 11 controls a plurality of hydraulic pressure control valves to switch the hydraulic pressure supply path based on the shift control signal from the transmission controller 12.

The integrated controller 13 performs integrated management of a plurality of vehicle-mounted controllers so that transmission control by the transmission controller 12 and engine control by the engine controller 14 are appropriately ensured. The integrated controller 13 is connected to an in-vehicle controller such as a transmission controller 12 or an engine controller 14 so that information can be exchanged via a CAN communication line 25.

The engine controller 14 performs fuel cut control of the engine 1 at the time of accelerator release operation, engine start control of starting the engine 1 by using the starter motor 15, and the like. The output signal of the engine rotation speed sensor 47 that detects the rotation speed of the engine 1 (hereinafter, referred to as "engine rotation speed Ne") is input to the engine controller 14.

[Shift control configuration using shift map]
FIG. 3 shows an example of a shift map stored in the storage device of the transmission controller. Hereinafter, a shift control configuration using a shift map will be described with reference to FIG.

The operating point of the automatic transmission 4 is determined based on the vehicle speed VSP and the primary rotation speed Npri on the shift map shown in FIG. The inclination of the line connecting the operating point of the automatic transmission 4 and the zero point in the lower left corner of the shift map is the overall ratio obtained by multiplying the gear ratio vRatio of the automatic transmission 4 by the gear ratio subRatio of the auxiliary transmission mechanism 30. The gear ratio of, hereinafter referred to as "through gear ratio").
In this shift map, a shift line is set for each accelerator opening APO as in the shift map of the conventional belt-type continuously variable transmission, and the shift of the automatic transmission 4 is selected according to the accelerator opening APO. It is done according to the transmission line. For simplicity, FIG. 3 shows the full load line F / L (shift line when the accelerator opening APO = 8/8) and the partial line P / L (shift when the accelerator opening APO = 4/8). Line) and coast line C / L (shift line when accelerator opening APO = 0) are shown.

When the automatic transmission 4 is in the low speed mode, the automatic transmission 4 is obtained by minimizing the low speed mode lowest line LL / L obtained by maximizing the gear ratio vRatio of the variator 20 and minimizing the gear ratio vRatio of the variator 20. It is possible to shift between the high speed line LH / L and the low speed mode. At this time, the operating point of the automatic transmission 4 moves in the A region and the B region. On the other hand, when the automatic transmission 4 is in the high-speed mode, the automatic transmission 4 obtains the highest speed mode lowest line HL / L obtained by maximizing the gear ratio vRatio of the variator 20 and the minimum gear ratio vRatio of the variator 20. It is possible to shift between the highest speed line HH / L and the high speed mode. At this time, the operating point of the automatic transmission 4 moves in the B region and the C region.

The gear ratio of each gear of the auxiliary transmission mechanism 30 is such that the gear ratio corresponding to the low speed mode highest line LH / L (low speed mode highest gear ratio) corresponds to the high speed mode lowest line HL / L ( It is set to be smaller than the highest gear ratio in high-speed mode. As a result, the low speed mode ratio range LRE, which is the range of the through gear ratio ratio of the automatic transmission 4 that can be taken in the low speed mode, and the high speed mode ratio range, which is the range of the through gear ratio ratio of the automatic transmission 4 that can be taken in the high speed mode. HRE and partially overlap. When the operating point of the automatic transmission 4 is in the B region (overlapping region) sandwiched between the high-speed mode highest line HL / L and the low-speed mode highest line LH / L, the automatic transmission 4 is in the low-speed mode and high-speed mode. Both modes can be selected.

The transmission controller 12 sets the through gear ratio Ratio corresponding to the vehicle speed VSP and the accelerator opening APO (driving state of the vehicle) as the reached through gear ratio D Ratio with reference to this shift map. This reached through gear ratio D Ratio is a target value that the through gear ratio Ratio should finally reach in the operating state. Then, the transmission controller 12 sets a target through gear ratio tRatio, which is a transient target value for causing the through gear ratio Ratio to follow the reached through gear ratio DRatio with a desired response characteristic, and the through gear ratio Ratio is the target. The variator 20 and the auxiliary transmission mechanism 30 are controlled so as to match the through gear ratio tRatio.

On the shift map, the mode switching up shift line MU / L (1 → 2 up shift line of the auxiliary transmission mechanism 30) for upshifting the auxiliary transmission mechanism 30 is abbreviated on the high speed mode highest line LH / L. It is set to overlap. The through gear ratio Ratio corresponding to the mode switching up shift line MU / L is substantially equal to the low speed mode highest line LH / L (low speed mode highest gear ratio). Further, on the shift map, the mode switching down shift line MD / L (2 → 1 down shift line of the auxiliary transmission mechanism 30) that performs the down shift of the auxiliary transmission mechanism 30 is on the lowest line HL / L in the high speed mode. It is set to almost overlap. The through gear ratio Ratio corresponding to the mode switching down shift line MD / L is substantially equal to the high speed mode lowest gear ratio (high speed mode lowest gear HL / L).

Then, when the operating point of the automatic transmission 4 crosses the mode switching up shift line MU / L or the mode switching down shift line MD / L, that is, the target through gear ratio tRatio of the automatic transmission 4 is the mode switching gear ratio mRatio. The transmission controller 12 performs mode switching shift control when the change is made across the above and when the mode switching gear ratio matches the mRatio. In this mode switching shift control, the transmission controller 12 shifts the auxiliary transmission mechanism 30 and changes the gear ratio vRatio of the variator 20 in the direction opposite to the direction in which the gear ratio subRatio of the auxiliary transmission mechanism 30 changes. In this way, "cooperative control" is performed to coordinate the two shifts.

In the "coordinated control", when the target through gear ratio tRatio of the automatic transmission 4 crosses the mode switching up shift line MU / L from the B region side toward the C region side, or when the mode switching up shifting is performed from the B region side. When it matches the line MU / L, the transmission controller 12 issues a 1 → 2 up shift determination, changes the shift stage of the auxiliary transmission mechanism 30 from 1st gear to 2nd gear, and changes the gear ratio vRatio of the variator 20. Change from the highest gear ratio to the low gear ratio. Conversely, when the target through gear ratio tRatio of the automatic transmission 4 crosses the mode switching down transmission line MD / L from the B region side toward the A region side, or when the mode switching down transmission line MD / L from the B region side If the result is the same, the transmission controller 12 issues a 2 → 1 down shift determination, changes the shift stage of the auxiliary transmission mechanism 30 from 2nd gear to 1st gear, and changes the gear ratio vRatio of the variator 20 from the lowest gear ratio. Change to the high gear ratio side.

The reason for performing "cooperative control" to change the gear ratio vRatio of the variator 20 during the mode switching up shift or the mode switching down shift is the change in the input rotation speed caused by the step of the through gear ratio ratio of the automatic transmission 4. This is because it is possible to suppress the driver's discomfort due to the above and to alleviate the shift shock of the auxiliary transmission mechanism 30.

Further, in the shift map shown in FIG. 3, the first target pramari rotation speed Npri1 (first target rotation speed) by the coast line C / L set when the accelerator opening APO is zero (APO = 0/8) is the accelerator. The opening APO is higher than the second target rotational speed Npri2 (second target rotation speed) by the drive line D / L set at the extremely low opening (APO = 1/8). That is, when the accelerator release operation is performed from the low load state, the target plasma rotation speed Npri2 increases to the target plasma rotation speed Npri1 and the target gear ratio is changed in the downshift direction.

[Pulley pressure control processing configuration during coast running]
FIG. 4 shows the flow of the pulley pressure control processing configuration during coast running executed by the transmission controller 12 of the first embodiment (control means). Hereinafter, each step of FIG. 4 showing the pulley pressure control processing configuration during coast running will be described.

In step S1, it is determined whether or not the accelerator release operation is performed during traveling with the engine 1 as the traveling drive source and the forward clutch Fwd / C (low brake 32 or high clutch 33) engaged. If YES (accelerator OFF), the process proceeds to step S2, and if NO (accelerator ON), the determination in step S1 is repeated.
Here, whether or not the accelerator release operation has been performed is determined by the accelerator opening signal from the accelerator opening sensor 41, and when the accelerator opening = 0, it is determined that the coast is running by the accelerator release operation. To do. The belt capacity set when the accelerator opening APO is zero is the belt required to prevent the V-belt 23 from slipping with respect to the input torque to the variator 20 when the accelerator opening APO is zero. This is the minimum capacity.

In step S2, following the determination that the accelerator is off in step S1, the SEC instruction pressure and the PRI instruction pressure are inclined to increase the instruction pressure, and the process proceeds to step S3.
Here, the SEC instruction pressure increase timing for increasing the belt capacity of the secondary pulley 22 and the PRI instruction pressure increase timing for increasing the belt capacity of the primary pulley 21 are set to the same accelerator OFF determination timing. The rising gradient θsec of the SEC indicated pressure on the secondary pulley 22 is set to the maximum value of the increasing gradient that the actual hydraulic pressure can follow with respect to the change in the SEC indicated pressure. Further, the rising gradient θpri of the PRI indicated pressure in the primary pulley 21 is the rising gradient θsec (>) of the SEC indicated pressure in the secondary pulley 22 so as to suppress the change in the gear ratio in the variator 20 even if there is a difference in hydraulic responsiveness. It is smaller than θpri). The predetermined value of the difference between the ascending gradient θsec and the ascending gradient θpri is determined so that the SEC actual pressure reaches the target increasing pressure before the PRI actual pressure, assuming the maximum variation in hydraulic responsiveness.

In step S3, following the increase in the slope of the SEC indicated pressure and the PRI indicated pressure in step S2, it is determined whether or not the SEC indicated pressure has reached the SEC indicated pressure target value. If YES (reached the SEC indicated pressure target value), the process proceeds to step S4, and if NO (not reached the SEC indicated pressure target value), the determination in step S3 is repeated.
Here, for the "SEC indicated pressure target value", the amount of increase for increasing the belt capacity in the primary pulley 21 and the secondary pulley 22 during the accelerator release operation is determined in advance, and the belt capacity is increased to the SEC indicated pressure at the start of the increase. The value shall be the value obtained by adding the instruction pressure to obtain a large amount.

In step S4, following the determination that the SEC indicated pressure target value in step S3 has been reached, the rise of the SEC indicated pressure to the secondary pulley 22 is stopped, and the process proceeds to step S5.
Here, "stop rising SEC indicated pressure" maintains the SEC indicated pressure when stopped until the next change to the new target gear ratio.

In step S5, following the stoppage of the increase in the EC indicated pressure in step S4, it is determined whether or not the PRI indicated pressure has reached the PRI indicated pressure target value. If YES (reached the PRI indicated pressure target value), the process proceeds to step S6, and if NO (not reached the PRI indicated pressure target value), the determination in step S5 is repeated.
Here, for the "PRI indicated pressure target value", the amount of increase in which the belt capacity of the primary pulley 21 and the secondary pulley 22 is increased during the accelerator release operation is determined in advance, and the belt capacity is increased to the PRI indicated pressure at the start of the increase. The value shall be the value obtained by adding the instruction pressure to obtain a large amount.

In step S6, following the determination that the PRI instruction pressure target value in step S5 has been reached, the increase in the PRI instruction pressure to the primary pulley 21 is stopped, and the process proceeds to the end.
Here, "stop rising PRI instruction pressure" maintains the PRI instruction pressure at the time of stopping until the next change to the new target gear ratio.

Next, the action will be described.
The actions of the engine vehicle variator control device of the first embodiment are described as "pulley pressure control processing action during coast running", "pulley pressure control action during coast running", and "characteristic action of pulley pressure control during coast running". The explanation will be divided into.

[Pulley pressure control processing action during coast running]
The pulley pressure control processing action during coast running of the first embodiment will be described with reference to the flowchart shown in FIG.

First, when the accelerator release operation is performed while the engine 1 is used as the traveling drive source and the forward clutch Fwd / C is engaged, the process proceeds to step S1 → step S2 → step S3 in the flowchart of FIG. In step S2, the indicated pressure increase in which the SEC indicated pressure and the PRI indicated pressure are inclined is started at the same accelerator OFF determination timing, and the indicated pressure increases until the SEC indicated pressure and the PRI indicated pressure reach their respective target values. Is continued. When the indicated pressure rises, the rising gradient θsec of the SEC indicated pressure to the secondary pulley 22 is set to the maximum value of the increasing gradient that the actual hydraulic pressure can follow with respect to the change in the SEC indicated pressure. On the other hand, the rising gradient θpri of the PRI indicated pressure in the primary pulley 21 is made smaller than the rising gradient θsec of the SEC indicated pressure in the secondary pulley 22.

Then, after the SEC instruction pressure and the PRI instruction pressure are inclined and start to rise, if it is determined that the SEC instruction pressure has reached the SEC instruction pressure target value first, the process from step S3 to step S4 → step S5. move on. In step S4, the increase in the SEC instruction pressure to the secondary pulley 22 is stopped, and then the increased SEC instruction pressure is maintained.

After the SEC indicated pressure reaches the SEC indicated pressure target value, if it is determined that the PRI indicated pressure has reached the PRI indicated pressure target value with a delay, the process proceeds from step S5 to step S6. In step S6, the increase in the PRI instruction pressure to the primary pulley 21 is stopped, and then the increased PRI instruction pressure is maintained.

As described above, in the first embodiment, when the start timing of the indicated pressure increase is the same, the PRI instruction pressure is increased in order to suppress the change in the gear ratio in the variator 20, particularly the change in the gear ratio to the upshift side. The gradient θpri and the rising gradient θsec of the SEC indicated pressure are different.

[Pulley pressure control action during coast driving]
The pulley pressure control action during coast running of Example 1 will be compared and described based on the time charts shown in FIGS. 5 (Comparative Example) and 6 (Example 1).

The purpose of increasing the belt capacity with the accelerator release operation is to prevent the belt from slipping due to insufficient belt capacity with respect to the input torque from the drive wheels to the belt when the brake pedal is depressed after the accelerator release operation. To do. Therefore, when increasing the PRI instruction pressure and the SEC instruction pressure so as to increase the belt capacities of the primary pulley and the secondary pulley based on the accelerator release operation, the instruction pressure increase start timing is the same, and both are stepwise. A comparative example is one that raises the indicated pressure.

In the case of this comparative example, as shown in FIG. 5, when the PRI indicated pressure and the SEC indicated pressure are increased stepwise at time t1, the hydraulic pressure supply to the secondary pulley is delayed due to hydraulic pressure variation and operation delay, and the secondary pulley The increase in belt capacity may be delayed. That is, the actual PRI pressure reaches the PRI target actual pressure at time t3, while the SEC actual pressure reaches the SEC target actual pressure at time t4. This also occurs when the belt capacity of the primary pulley increases faster. In this case, the difference between the belt capacities of both pulleys decreases or disappears, as the actual SEC pressure and the actual PRI pressure may match around the time t3 in FIG. That is, even though the target gear ratio is changed to the downshift direction at time t2, as shown in the actual gear ratio characteristics in the frame indicated by the arrow D in FIG. 5, the target gear ratio is after time t2. Upshift occurs in the opposite direction.

In recent years, the drive line D / L at low load (APO = extremely low opening) has been set low to improve fuel efficiency, and the coast at coast (APO = 0) has been set to prevent engine stalls and increase the regenerative capacity during coasting. There is a shift map (Fig. 3) in which the coast line C / L is set to a higher rotation speed than the drive line D / L when the load is low by setting the line C / L higher. When such a shift map is used, the target gear ratio is changed in the downshift direction when the accelerator is released from a low load, but an upshift occurs as described above.

In this way, if the balance thrust ratio collapses due to the difference in hydraulic responsiveness and an upshift occurs in which the belt capacity of the primary pulley increases and the belt winding diameter on the primary pulley side increases, the upshift causes the CVT input rotation. The number decreases, that is, the engine speed decreases. Therefore, the lockup clutch arranged between the engine and the variator to prevent the engine stall is released, for example, at the time t5 in FIG. Therefore, in the coastal running until the brake operation is started, the fuel cut cannot be performed and the fuel consumption cannot be improved. That is, in the case of the comparative example, the fuel cut permitted section is from the accelerator release operation time t1 to the lockup clutch release time t5, and the fuel cut prohibition section is from the lockup clutch release time t5 to the brake operation start time t6.

On the other hand, in the first embodiment, the instruction pressure increase in which the SEC instruction pressure and the PRI instruction pressure are inclined is started at the same accelerator OFF determination timing, and the SEC instruction pressure increase gradient θsec and the PRI instruction pressure increase gradient are started. The relationship of θpri is set to θsec> θpri.
Here, in FIG. 6, time t1 is the accelerator OFF time, time t2 is the target gear ratio change time, time t3 is the SEC actual pressure target value arrival time, time t4 is the PRI actual pressure target value arrival time, and time t5 is. This is the brake operation start time.

In the case of the first embodiment, as shown in FIG. 6, when the PRI indicated pressure and the SEC indicated pressure are increased with an inclination at time t1, the SEC actual pressure reaches the SEC target actual pressure at time t3. On the other hand, the actual PRI pressure reaches the PRI target actual pressure at time t4. That is, the time t3 at which the SEC actual pressure due to the hydraulic pressure supply to the secondary pulley 22 reaches the SEC target actual pressure precedes, and the time t4 at which the PRI actual pressure due to the hydraulic pressure supply to the primary pulley 21 reaches the PRI target actual pressure is delayed. .. In this case, looking at the relationship between the actual SEC pressure and the actual PRI pressure between the time t1 and the time t4 in FIG. 6, the relationship of SEC actual pressure> PRI actual pressure is maintained, and both pulleys 21 and 22 have the relationship. The difference in belt capacity is secured. That is, when the target gear ratio is changed in the downshift direction at time t2 (point E → point F in FIG. 3), as shown in the actual gear ratio characteristics in FIG. 6, the target is targeted from time t2 toward time t4. A downshift occurs in which the gear shift gradually progresses along the gear ratio.

As described above, even if there is a difference in hydraulic responsiveness between the primary pulley 21 and the secondary pulley 22, the balance thrust ratio is increased from time t2 to time t4 as shown in the actual balance thrust ratio characteristic of FIG. It is stable as it changes with a gentle gradient. Then, the CVT input rotation speed (Npri) increases, that is, the engine rotation speed increases due to a slight downshift in which the belt winding diameter on the secondary pulley side increases. Therefore, the engagement of the lockup clutch 9 arranged between the engine 1 and the variator 20 is maintained. Therefore, the fuel cut of the engine 1 can be performed in the coastal running until the brake operation is started, and the fuel consumption can be improved. That is, in the case of the first embodiment, the fuel cut permission section is from the accelerator release operation time t1 to the brake operation start time t5.

[Characteristic action of pulley pressure control during coast driving]
In the first embodiment, at least when the accelerator opening APO becomes zero, the belt capacity of the primary pulley 21 is increased so as to suppress the change in the gear ratio accompanying the increase of the belt capacity of the secondary pulley 22. Then, when the belt capacity of both pulleys 21 and 22 is increased, the increase of the belt capacity of the primary pulley 21 is made slower than the increase of the belt capacity of the secondary pulley 22.
Here, the belt capacity increase control of the first embodiment is performed between the time when the accelerator opening APO becomes zero and the time when the braking force is generated by depressing the brake pedal.
That is, even if the variator 20 varies or delays in operation while the belt capacity is increasing, the belts of both pulleys 21 and 22 maintain the relationship of (belt capacity in the secondary pulley 22)> (belt capacity in the primary pulley 21). The capacity difference is secured. By securing the belt capacity difference in this way, it is possible to prevent the variator 20 from shifting in the upshift direction when the belt capacity is increased. By this upshift prevention, the release of the lockup clutch 9 due to the decrease in the engine speed Ne is suppressed, and the driving scene in which the fuel cut of the engine 1 can be performed is expanded.
As a result, fuel efficiency is improved by expanding the driving scene in which fuel cut can be performed while driving on the coast by releasing the accelerator.

In the first embodiment, the increase gradient of the belt capacity in the primary pulley 21 is made smaller than the increase gradient of the belt capacity in the secondary pulley 22.
Therefore, by making the increase gradient of the belt capacity of both pulleys 21 and 22 different, it is possible to prevent the increase of the belt capacity of the primary pulley 21 from becoming faster than the increase of the belt capacity of the secondary pulley 22.

In the first embodiment, the instruction hydraulic pressure start timing for increasing the belt capacity in the primary pulley 21 and the secondary pulley 22 is set to the same timing. The ascending gradient θpri of the PRI instruction pressure to the primary pulley 21 is made smaller than the ascending gradient θsec to the secondary pulley 22.
For example, by delaying the increase timing of the belt capacity in the primary pulley 21 from the increase timing of the belt capacity in the secondary pulley 22, the increase in the PRI actual pressure can be delayed from the increase in the SEC actual pressure. However, in this case, a timer or the like for measuring the delay time is required. On the other hand, the instruction hydraulic pressure start timing is the same, and the PRI instruction pressure ascending gradient θpri and the SEC instruction pressure ascending gradient θsec of both pulleys 21 and 22 are only different.
Therefore, a simple configuration prevents the actual PRI pressure in the primary pulley 21 from increasing faster than the actual SEC pressure in the secondary pulley 22.

In the first embodiment, the rising gradient θsec of the SEC indicated pressure on the secondary pulley 22 is set to the maximum value of the rising gradient that the SEC actual pressure can follow the change of the SEC indicated pressure.
That is, if the increasing gradient of the SEC indicated pressure on the secondary pulley 22 is made too large, a difference will occur between the SEC indicated pressure and the SEC actual pressure due to the operation delay of the SEC actual pressure. This increases as the increasing gradient increases. Since the SEC actual pressure of the secondary pulley 22 at this time cannot be grasped, the primary pulley 21 is controlled on the assumption that the SEC actual pressure is generated according to the SEC indicated pressure. With this, the intended shift cannot be performed.
Therefore, by setting the SEC actual pressure to an increasing gradient that can follow the SEC instruction pressure, the intended shift can be performed. Further, by setting the maximum value of the increasing gradient that can be followed, it is possible to shift gears as quickly as possible.

Next, the effect will be described.
In the control device for the engine vehicle variator of the first embodiment, the effects listed below can be obtained.

(1) A continuously variable transmission mechanism (variator 20) arranged between the engine 1 and the drive wheels 7 and provided with a primary pulley 21, a secondary pulley 22, and a belt 23.
A torque converter 2 having a lockup clutch 9 arranged between the engine 1 and the continuously variable transmission mechanism (variator 20) and whose engagement / release is controlled, and
A control means (transmission controller 12) that increases the belt capacity in the secondary pulley 22 from the belt capacity set when the accelerator opening APO is zero, at least based on the fact that the accelerator opening APO becomes zero.
It is a control device of a continuously variable transmission mechanism (variator for engine vehicles) for vehicles equipped with.
The control means (transmission controller 12) increases the belt capacity of the primary pulley 21 so as to suppress the change in the gear ratio due to the increase of the belt capacity of the secondary pulley 22.
When increasing the belt capacity of the primary pulley 21 and the secondary pulley 22, the increase of the belt capacity of the primary pulley 21 is made slower than the increase of the belt capacity of the secondary pulley 22.
Therefore, it is possible to improve fuel efficiency by expanding the driving scene in which fuel cutting can be performed during coastal driving.

(2) The control means (transmission controller 12) makes the increase gradient of the belt capacity in the primary pulley 21 smaller than the increase gradient of the belt capacity in the secondary pulley 22.
Therefore, in addition to the effect of (1), by making a difference in the increase gradient of the belt capacity of both pulleys 21 and 22, the increase of the belt capacity in the primary pulley 21 is faster than the increase of the belt capacity in the secondary pulley 22. It can be prevented from becoming.

(3) The control means (transmission controller 12) sets the instruction hydraulic pressure start timing (time t1) for increasing the belt capacity in the primary pulley 21 and the secondary pulley 22 to the same timing.
The ascending gradient θsec of the indicated hydraulic pressure (SEC indicated pressure) to the secondary pulley 22 is set to the maximum value of the ascending gradient that the actual hydraulic pressure (SEC actual pressure) can follow the change of the indicated hydraulic pressure (SEC indicated pressure). The ascending gradient θpri of the indicated hydraulic pressure (PRI indicated pressure) to the primary pulley 21 is made smaller than the ascending gradient θsec to the secondary pulley 22.
Therefore, in addition to the effect of (2), it is possible to prevent the increase in the actual PRI pressure in the primary pulley 21 from becoming faster than the increase in the actual pressure in the SEC in the secondary pulley 22 by a simple configuration.

(4) The control means (transmission controller 12) sets an ascending gradient θsec of the indicated hydraulic pressure (SEC indicated pressure) to the secondary pulley 22 with respect to a change in the indicated hydraulic pressure (SEC indicated pressure) by the actual hydraulic pressure (SEC actual pressure). Set to the maximum value of the ascending gradient that can be followed.
Therefore, in addition to the effect of (3), the intended shift is performed by setting the actual hydraulic pressure (SEC actual pressure) to the maximum value of the increasing gradient that can follow the change of the indicated hydraulic pressure (SEC indicated pressure). At the same time, it is possible to shift gears with good response.

The second embodiment is an example in which the instruction hydraulic pressure start timing for increasing the belt capacity in both pulleys 21 and 22 is different, and the ascending gradient of the indicated hydraulic pressure to both pulleys 21 and 22 is the same.

First, the configuration will be described.
Of the configurations of the control device for the engine vehicle variator in the second embodiment, the "overall system configuration" and the "shift control configuration by the shift map" are the same as those in FIGS. 1 to 3 of the first embodiment, and are therefore illustrated and described. Is omitted. Hereinafter, “Pulley pressure control processing configuration during coast running” of Example 2 will be described.

[Pulley pressure control processing configuration during coast running]
FIG. 7 shows the flow of the pulley pressure control processing configuration during coast running executed by the transmission controller 12 of the second embodiment (control means). Hereinafter, each step of FIG. 7 showing the pulley pressure control processing configuration during coast running will be described.

In step S21, it is determined whether or not the accelerator release operation is performed during traveling with the engine 1 as the traveling drive source and the forward clutch Fwd / C (low brake 32 or high clutch 33) engaged. If YES (accelerator OFF), the process proceeds to step S22, and if NO (accelerator ON), the determination in step S21 is repeated.

In step S22, following the determination that the accelerator is off in step S21, the SEC instruction pressure is tilted to increase the instruction pressure, and the process proceeds to step S23.
Here, the rising gradient θsec of the SEC indicated pressure on the secondary pulley 22 is set to the maximum value of the increasing gradient that the actual hydraulic pressure can follow with respect to the change in the SEC indicated pressure.

In step S23, following the increase in the SEC indicated pressure in step S22 or the determination that the delay timer ≤ the predetermined value in step 24, the delay timer until the increase in the PRI indicated pressure is counted, and the process proceeds to step S24.

In step S24, following the delay timer count in step S23, it is determined whether or not the delay timer exceeds a predetermined value. If YES (delay timer> predetermined value), the process proceeds to step S25, and if NO (delay timer ≤ predetermined value), the process returns to step S23.
Here, the delay time, which is a predetermined value of the delay timer, is the time when the SEC actual pressure due to the hydraulic pressure supply to the secondary pulley 22 reaches the SEC target actual pressure even if there is a hydraulic pressure variation or an operation delay. PRI Set to a time that precedes the time when the target actual pressure is reached.

In step S25, following the determination that the delay timer> the predetermined value in step S24, the PRI instruction pressure is tilted to increase the instruction pressure, and the process proceeds to step S26.
Here, the rising gradient θpri of the PRI instruction pressure to the primary pulley 21 is set to be the same as the rising gradient θsec of the SEC instruction pressure to the secondary pulley 22.

In step S26, following the increase in the PRI indicated pressure in step S25, it is determined whether or not the SEC indicated pressure has reached the SEC indicated pressure target value. If YES (reaching the SEC indicated pressure target value), the process proceeds to step S27, and if NO (not reaching the SEC indicated pressure target value), the determination in step S26 is repeated.

In step S27, following the determination that the SEC indicated pressure target value in step S26 has been reached, the rise of the SEC indicated pressure to the secondary pulley 22 is stopped, and the process proceeds to step S28.

In step S28, following the stoppage of the increase in the EC indicated pressure in step S27, it is determined whether or not the PRI indicated pressure has reached the PRI indicated pressure target value. If YES (reached the PRI indicated pressure target value), the process proceeds to step S29, and if NO (not reached the PRI indicated pressure target value), the determination in step S28 is repeated.

In step S29, following the determination that the PRI instruction pressure target value in step S28 has been reached, the increase in the PRI instruction pressure to the primary pulley 21 is stopped, and the process proceeds to the end.

Next, the action will be described.
The actions of the engine vehicle variator control device of the second embodiment are described as "pulley pressure control processing action during coast running", "pulley pressure control action during coast running", and "characteristic action of pulley pressure control during coast running". The explanation will be divided into.

[Pulley pressure control processing action during coast running]
The pulley pressure control processing action during coast running of the second embodiment will be described with reference to the flowchart shown in FIG.

First, when the accelerator release operation is performed while the engine 1 is used as the traveling drive source and the forward clutch Fwd / C is engaged, the process proceeds to step S21 → step S22 → step S23 → step S24 in the flowchart of FIG. .. In step S22, the instruction pressure increase in which the SEC instruction pressure is inclined is started at the accelerator OFF determination timing, and the instruction pressure increase is continued until the SEC instruction pressure reaches the target value. While the SEC instruction pressure is rising, the delay timer is counted in step S23, and in step 24, it is determined whether or not the delay timer> a predetermined value.

In step 24, when it is determined that the delay timer> the predetermined value, the process proceeds from step S24 to step S25, and in step S25, the indicated pressure increase with the PRI indicated pressure tilted is delayed from the start of the increase in the SEC indicated pressure. It will start with a delay of time. After that, the increase in the PRI instruction pressure is continued until the target value is reached.

Then, after the SEC indicated pressure and the PRI indicated pressure are inclined with the same gradient and increased at different ascending start timings, it is determined that the SEC indicated pressure has reached the SEC indicated pressure target value first, and then step S25. From step S26 to step S27. In step S27, the increase in the SEC instruction pressure to the secondary pulley 22 is stopped, and then the increased SEC instruction pressure is maintained.

After the SEC indicated pressure reaches the SEC indicated pressure target value, if it is determined that the PRI indicated pressure has reached the PRI indicated pressure target value with a delay, the process proceeds from step S28 to step S29. In step S29, the increase in the PRI instruction pressure to the primary pulley 21 is stopped, and then the increased PRI instruction pressure is maintained.

As described above, in the second embodiment, when the ascending gradient θpri of the PRI indicated pressure and the ascending gradient θsec of the SEC indicated pressure are the same, the change in the gear ratio in the variator 20, particularly the change in the gear ratio to the upshift side. The timing at which the SEC instruction pressure starts to rise and the timing at which the PRI instruction pressure starts to rise are different.

[Pulley pressure control action during coast driving]
The pulley pressure control action during coast running of the second embodiment will be described with reference to the time chart shown in FIG.

In the second embodiment, the relationship between the rising gradient θsec of the SEC indicated pressure and the rising gradient θpri of the PRI indicated pressure is set to θsec = θpri, and the indicated pressure rise with the slope of the SEC indicated pressure and the PRI indicated pressure is set at different timings. Has started.
Here, in FIG. 8, time t1 is the accelerator OFF & SEC indicated pressure increase start time, time t2 is the target gear ratio change time, time t3 is the PRI indicated pressure increase start time, and time t4 is the SEC actual pressure target value arrival time and time. t5 is the time when the target value of PRI actual pressure is reached, and time t6 is the time when the brake operation is started.

In the case of the second embodiment, as shown in FIG. 8, the SEC indicated pressure is inclined to start the increase at time t1, and the PRI indicated pressure is inclined to start the increase at time t3. That is, the time t1 to the time t3 is the delay time for the start of the indicated pressure rise. The actual SEC pressure reaches the SEC target actual pressure at time t4, while the PRI actual pressure reaches the PRI target actual pressure at time t5. That is, the time t4 at which the SEC actual pressure due to the hydraulic pressure supply to the secondary pulley 22 reaches the SEC target actual pressure precedes, and the time t5 at which the PRI actual pressure due to the hydraulic pressure supply to the primary pulley 21 reaches the PRI target actual pressure is delayed. .. In this case, looking at the relationship between the SEC actual pressure and the PRI actual pressure between the time t1 and the time t5 in FIG. 8, the relationship of SEC actual pressure> PRI actual pressure is maintained, and both pulleys 21 and 22 The difference in belt capacity is secured. That is, when the target gear ratio is changed in the downshift direction at time t2 (point E → point F in FIG. 3), as shown in the actual gear ratio characteristics in FIG. 8, the target is targeted from time t2 toward time t5. A downshift occurs in which the gear shift gradually progresses along the gear ratio.

In this way, even if there is a difference in hydraulic responsiveness between the primary pulley 21 and the secondary pulley 22, the balanced thrust ratio increases from time t2 to time t3 as shown in the actual balance thrust ratio characteristics of FIG. It is stable as it changes with a gentle gradient. Then, the CVT input rotation speed (Npri) increases, that is, the engine rotation speed increases due to a slight downshift in which the belt winding diameter on the secondary pulley side increases. Therefore, the engagement of the lockup clutch 9 arranged between the engine 1 and the variator 20 is maintained. Therefore, the fuel cut of the engine 1 can be performed in the coastal running until the brake operation is started, and the fuel consumption can be improved. That is, in the case of the second embodiment, the fuel cut permission section is from the accelerator release operation time t1 to the brake operation start time t6.

[Characteristic action of pulley pressure control during coast driving]
In the second embodiment, the belt capacity increase start timing of the primary pulley 21 is delayed from the belt capacity increase start timing of the secondary pulley 22.
Therefore, by providing a time lag between the belt capacity increase start timings of both pulleys 21 and 22, it is possible to prevent the belt capacity increase in the primary pulley 21 from becoming faster than the belt capacity increase in the secondary pulley 22.

In the second embodiment, the time when the accelerator release operation is determined is set as the instruction hydraulic pressure start timing to the secondary pulley 22, and the timing when the delay time is provided from the instruction hydraulic pressure start time to the secondary pulley 22 is the instruction hydraulic pressure start timing to the primary pulley 21. And. Then, the rising gradients of the PRI instruction pressure and the SEC instruction pressure of the primary pulley 21 and the secondary pulley 22 are set to the same gradient.
For example, when there is a difference between the rising gradient θpri of the PRI indicated pressure and the rising gradient θsec of the SEC indicated pressure of both pulleys 21 and 22, if there is an unintended delay in hydraulic response, it may not be possible to deal with this. On the other hand, if a sufficient delay time is provided, it becomes possible to cope with an unintended delay in hydraulic response.
Therefore, it is surely prevented that the increase in the PRI actual pressure in the primary pulley 21 becomes faster than the increase in the SEC actual pressure in the secondary pulley 22.

Next, the effect will be described.
In the control device of the engine vehicle variator of the second embodiment, the effects listed below can be obtained.

(5) The control means (transmission controller 12) delays the start timing of increasing the belt capacity of the primary pulley 21 from the start timing of increasing the belt capacity of the secondary pulley 22.
Therefore, in addition to the effect of (1) or (2), the increase in the belt capacity in the primary pulley 21 is increased by giving a time difference to the start timing of the increase in the belt capacity of both pulleys 21 and 22, and the belt in the secondary pulley 22 is increased. It is possible to prevent the capacity from increasing faster than the increase.

(6) In the control means (transmission controller 12), the time when the accelerator release operation is determined is set as the instruction hydraulic pressure start timing to the secondary pulley 22, and the timing when the delay time is provided from the instruction hydraulic pressure start time to the secondary pulley 22 is the primary. As the instruction hydraulic pressure start timing to the pulley 21,
The rising gradients of the respective indicated hydraulic pressures (PRI indicated pressure, SEC indicated pressure) in the primary pulley 21 and the secondary pulley 22 are the same gradient.
Therefore, in addition to the effect of (5), it is possible to reliably prevent the increase in the belt capacity (PRI actual pressure) in the primary pulley 21 from becoming faster than the increase in the belt capacity (SEC actual pressure) in the secondary pulley 22. it can.

The third embodiment is an example in which the instruction hydraulic pressure start timing for increasing the belt capacity in both pulleys 21 and 22 is different, and the ascending gradient of the indicated hydraulic pressure to both pulleys 21 and 22 is given by the step characteristic.

First, the configuration will be described.
Of the configurations of the control device for the engine vehicle variator in the third embodiment, the "overall system configuration" and the "shift control configuration by the shift map" are the same as those in FIGS. 1 to 3 of the first embodiment, and are therefore illustrated and described. Is omitted. Hereinafter, “Pulley pressure control processing configuration during coast running” of Example 3 will be described.

[Pulley pressure control processing configuration during coast running]
FIG. 9 shows the flow of the pulley pressure control processing configuration during coast running executed by the transmission controller 12 of the third embodiment (control means). Hereinafter, each step of FIG. 9 showing the pulley pressure control processing configuration during coast running will be described.

In step S31, it is determined whether or not the accelerator release operation is performed during traveling with the engine 1 as the traveling drive source and the forward clutch Fwd / C (low brake 32 or high clutch 33) engaged. If YES (accelerator OFF), the process proceeds to step S32, and if NO (accelerator ON), the determination in step S31 is repeated.

In step S32, following the determination that the accelerator is off in step S31, the SEC instruction pressure is increased by the step characteristic, and the process proceeds to step S33.
Here, the SEC instruction pressure increase characteristic to the secondary pulley 22 is a characteristic that suddenly rises from the SEC instruction pressure at the time of determining the accelerator OFF to the SEC instruction pressure target value.

In step S33, following the step increase of the SEC instruction pressure in step S32 or the determination that the delay timer ≤ predetermined value in step 34, the delay timer until the step increase of the PRI instruction pressure is counted, and step S34 Proceed to.

In step S34, following the delay timer count in step S33, it is determined whether or not the delay timer exceeds a predetermined value. If YES (delay timer> predetermined value), the process proceeds to step S35, and if NO (delay timer ≤ predetermined value), the process returns to step S33.
Here, the delay time, which is a predetermined value of the delay timer, is the time when the SEC actual pressure due to the hydraulic pressure supply to the secondary pulley 22 reaches the SEC target actual pressure even if there is a hydraulic pressure variation or an operation delay. PRI Set to a time that precedes the time when the target actual pressure is reached.

In step S35, following the determination that the delay timer> the predetermined value in step S34, the PRI instruction pressure is increased by the step characteristic and proceeds to the end.
Here, the PRI instruction pressure increase characteristic for the secondary pulley 22 is a characteristic for raising the PRI instruction pressure from the PRI instruction pressure when the delay time elapsed condition of step S34 is satisfied to the PRI instruction pressure target value at once.

Next, the action will be described.
The actions in the control device of the engine vehicle variator of Example 3 are "pulley pressure control processing action during coast running", "pulley pressure control action during coast running", and "characteristic action of pulley pressure control during coast running". The explanation will be divided into.

[Pulley pressure control processing action during coast running]
The pulley pressure control processing action during coast running of the third embodiment will be described with reference to the flowchart shown in FIG.

First, when the accelerator release operation is performed while the engine 1 is used as the traveling drive source and the forward clutch Fwd / C is engaged, the process proceeds to step S31 → step S32 → step S33 → step S34 in the flowchart of FIG. .. In step S32, the SEC instruction pressure is stepwise increased at the accelerator OFF determination timing, and the SEC instruction pressure reaches the target value at once. After that, the delay timer is counted in step S33 until the actual SEC pressure starts to rise based on the SEC indicated pressure, and in step 34, it is determined whether or not the delay timer> a predetermined value.

In step 34, when it is determined that the delay timer> the predetermined value, the process proceeds from step S34 to step S35, and in step S35, the stepwise increase in the PRI indicated pressure changes from the stepwise increase in the SEC indicated pressure to the delay time. It is done only with a delay, and the indicated pressure reaches the target value at once.

As described above, in the third embodiment, when the ascending gradient θpri of the PRI instruction pressure and the ascending gradient θsec of the SEC instruction pressure are set to the same 90 degrees, the change in the gear ratio in the variator 20, particularly the shift to the upshift side. In order to suppress the ratio change, the stepwise rise timing of the SEC instruction pressure and the stepwise rise timing of the PRI instruction pressure are different.

[Pulley pressure control action during coast driving]
The pulley pressure control action during coastal travel of Example 3 will be described with reference to the time chart shown in FIG.

In the third embodiment, the relationship between the rising gradient θsec of the SEC indicated pressure and the rising gradient θpri of the PRI indicated pressure is set to θsec = θpri = 90 degrees, and the output timings of the SEC indicated pressure and the PRI indicated pressure due to the step characteristics are different. I'm letting you.
Here, in FIG. 10, time t1 is the accelerator OFF & SEC indicated pressure output time, time t2 is the target gear ratio change time, time t3 is the PRI indicated pressure output time, time t4 is the SEC actual pressure target value arrival time, and time t5 is. The target value arrival time of PRI actual pressure, time t6 is the brake operation start time.

In the case of the third embodiment, as shown in FIG. 10, the SEC indicated pressure due to the stepped characteristic is output at time t1, and the PRI indicated pressure due to the stepped characteristic is output at time t3. That is, the time t1 to the time t3 is the delay time of the indicated pressure output. The actual SEC pressure reaches the peak pressure at time t4 and then converges to the SEC target actual pressure, whereas the actual PRI pressure reaches the peak pressure at time t5 and then converges to the PRI target actual pressure. .. That is, the time t4 at which the SEC actual pressure due to the hydraulic pressure supply to the secondary pulley 22 reaches the peak pressure precedes, and the time t5 at which the PRI actual pressure due to the hydraulic pressure supply to the primary pulley 21 reaches the peak pressure is delayed. In this case, looking at the relationship between the SEC actual pressure and the PRI actual pressure between the time t1 and the time t5 in FIG. 10, the relationship of SEC actual pressure> PRI actual pressure is maintained, and both pulleys 21 and 22 The difference in belt capacity is secured wider than in Examples 1 and 2. That is, when the target gear ratio is changed in the downshift direction at time t2 (point E → point F in FIG. 3), as shown in the actual gear ratio characteristics in FIG. 10, the target is targeted from time t2 toward time t5. A downshift occurs in which the gear shift progresses with good response toward the gear ratio. This point is clear from the fact that the balance thrust ratio changes with a slightly steep gradient from time t2 to time t4, as shown in the actual balance thrust ratio characteristic of FIG.

Then, a downshift in which the belt winding diameter on the secondary pulley side becomes large occurs promptly, so that the CVT input rotation speed (Npri) increases, that is, the engine rotation speed increases. Therefore, the engagement of the lockup clutch 9 arranged between the engine 1 and the variator 20 is maintained. Therefore, the fuel cut of the engine 1 can be performed in the coastal running until the brake operation is started, and the fuel consumption can be improved. That is, in the case of the second embodiment, the fuel cut permission section is from the accelerator release operation time t1 to the brake operation start time t6.

[Characteristic action of pulley pressure control during coast driving]
In the third embodiment, the PRI instruction pressure and the SEC instruction pressure of the primary pulley 21 and the secondary pulley 22 are given as stepped characteristics.
That is, by applying the PRI instruction pressure and the SEC instruction pressure in a stepped characteristic, the belt capacity of the primary pulley 21 and the belt capacity of the secondary pulley 22 can be rapidly increased.
Therefore, when the belt capacities of the primary pulley 21 and the secondary pulley 22 are increased, the downshift is promoted while surely preventing the upshift.

In the third embodiment, in the variator 20, the first target primary rotation speed Npri1 set when the accelerator opening APO is zero is higher than the second target primary rotation speed Npri2 set when the accelerator opening APO is extremely low. It is controlled by the shift map (Fig. 3).
That is, when the SEC actual pressure and the PRI actual pressure are increased with the accelerator release operation, the downshift from the second target primary rotation speed Npri2 to the first target primary rotation speed Npri1 in the shift map as shown in FIG. A request occurs. At this time, downshifting is performed in response to the downshift request by increasing the difference between the belt capacity of the secondary pulley 22 and the belt capacity of the primary pulley 21.

Next, the effect will be described.
In the control device of the engine vehicle variator of the third embodiment, the following effects can be obtained.

(7) The control means (transmission controller 12) gives the indicated hydraulic pressures (PRI indicated pressure, SEC indicated pressure) of the primary pulley 21 and the secondary pulley 22 in a stepped characteristic.
Therefore, in addition to the effect of (6), when the belt capacities of the primary pulley 21 and the secondary pulley 22 are increased, the downshift can be promoted while surely preventing the upshift.

(8) In the continuously variable transmission mechanism (variator 20), the first target rotation speed (Npri1) set when the accelerator opening APO is zero is set, and the second target rotation is set when the accelerator opening APO is extremely low. It is controlled by a shift map (Fig. 3) higher than the speed (Npri2).
Therefore, in addition to the effects of (1) to (7), the difference between the belt capacity of the secondary pulley 22 and the belt capacity of the primary pulley 21 is increased to meet the downshift request generated by the accelerator release operation. be able to.
Here, it is possible to increase the difference in belt capacity between the pulleys 21 and 22 by any of the controls of Examples 1 to 3. Of these, as in Example 3, when the belt capacity of the secondary pulley 22 is increased, if the SEC indicated pressure is given as a step-like characteristic, the downshift can be further advanced due to the increase due to the overshoot of the SEC actual pressure. it can.

The control device for the continuously variable transmission mechanism for a vehicle of the present invention has been described above based on Examples 1 to 3, but the specific configuration is not limited to these Examples, and claims are made. Design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim of the scope.

In the first embodiment, as a control means, an example is shown in which the start timing of the indicated hydraulic pressure for increasing the belt capacity in both pulleys 21 and 22 is the same, and the ascending gradient of the indicated hydraulic pressure to both pulleys 21 and 22 is different. In the second embodiment, as a control means, an example is shown in which the start timing of the indicated hydraulic pressure for increasing the belt capacity in both pulleys 21 and 22 is different, and the ascending gradient of the indicated hydraulic pressure to both pulleys 21 and 22 is the same. However, as the control means, an example may be obtained in which the first and second embodiments are combined, the start timing of the indicated hydraulic pressure for increasing the belt capacity in both pulleys is different, and the ascending gradient of the indicated hydraulic pressure to both pulleys is different. ..

In the first embodiment, an example is shown in which the rising gradient θpri of the PRI instruction pressure to the primary pulley 21 and the rising gradient θsec of the SEC instruction pressure to the secondary pulley 22 are given at predetermined predetermined values. However, the ascending gradient θpri and the ascending gradient θsec may be given as initial values and then corrected by learning correction. In this learning correction, specifically, when the downshift is slow, the ascending gradient θpri is increased or / and the ascending gradient θsec is decreased with respect to the intended downshift. If the downshift is fast, the ascending gradient θpri is reduced or / and the ascending gradient θsec is increased.

In Examples 2 and 3, an example in which the delay time is given by a predetermined time is shown. However, the delay time may be given as an initial value and then corrected by learning correction. In this learning correction, specifically, when the downshift is slow with respect to the intended downshift, the correction is performed to lengthen the delay time and delay the increase timing in the primary pulley. If the downshift is early, a correction is made to shorten the delay time, and the increase timing in the primary pulley is accelerated.

In the first embodiment, an example is shown in which the control device of the continuously variable transmission mechanism for a vehicle of the present invention is applied to an engine vehicle equipped with a continuously variable transmission with an auxiliary transmission. However, the control device of the present invention may be applied to a vehicle or the like equipped with a continuously variable transmission that does not have an auxiliary transmission.

1 Engine 2 Torque converter 3 Reduction gear vs. 4 Automatic transmission 5 Final gear vs. 6 Final reduction gear 7 Drive wheel 9 Lockup clutch 10 Mechanical oil pump 11 Hydraulic control circuit 12 Transmission controller (control means)
13 Integrated controller 20 Variator (continuously variable transmission)
21 Primary pulley 22 Secondary pulley 23 V-belt (belt)
30 Sub-transmission mechanism 31 Rabbinyo type planetary gear mechanism 32 Low brake 33 High clutch 34 Reverse brake 41 Accelerator opening sensor 43 Vehicle speed sensor 46 Brake switch

Claims (8)

A continuously variable transmission mechanism located between the engine and drive wheels and equipped with a primary pulley, a secondary pulley and a belt.
A torque converter arranged between the engine and the continuously variable transmission mechanism and provided with a lockup clutch whose engagement / release is controlled.
When the pulley thrust that presses the belt by the primary actual pressure supplied to the primary pulley and the secondary actual pressure supplied to the secondary pulley is called the belt capacity, the control means for controlling the belt capacity and
It is a control device of a continuously variable transmission mechanism for a vehicle equipped with
Wherein, during the coasting by the accelerator releasing operation to the accelerator opening becomes zero, the belt capacity in the secondary pulley, with respect to the accelerator opening is at zero input torque to the continuously variable transmission mechanism, the belt Increased from the minimum belt capacity required to prevent slippage,
The belt capacity in the primary pulley is increased so as to suppress the change in the gear ratio due to the increase in the belt capacity in the secondary pulley.
When increasing the belt capacity in the primary pulley and the secondary pulley, the increase in the belt capacity in the primary pulley is slower than the increase in the belt capacity in the secondary pulley. Control device. In the control device for the continuously variable transmission mechanism for a vehicle according to claim 1.
The control means is a control device for a continuously variable transmission mechanism for a vehicle, characterized in that the increase gradient of the belt capacity in the primary pulley is made smaller than the increase gradient of the belt capacity in the secondary pulley. In the control device for the continuously variable transmission mechanism for a vehicle according to claim 2.
The control means sets the instruction hydraulic pressure start timing for increasing the belt capacity in the primary pulley and the secondary pulley to the same timing.
A control device for a continuously variable transmission mechanism for a vehicle, characterized in that the ascending gradient of the indicated hydraulic pressure to the primary pulley is made smaller than the ascending gradient to the secondary pulley. In the control device for the continuously variable transmission mechanism for a vehicle according to claim 3.
The control means is a continuously variable transmission mechanism for a vehicle, wherein the ascending gradient of the indicated hydraulic pressure to the secondary pulley is set to the maximum value of the ascending gradient that the actual hydraulic pressure can follow the change of the indicated hydraulic pressure. Control device. In the control device for the continuously variable transmission mechanism for a vehicle according to claim 1 or 2.
The control means is a control device for a continuously variable transmission mechanism for a vehicle, characterized in that the timing for starting the increase in belt capacity in the primary pulley is later than the timing for starting the increase in belt capacity in the secondary pulley. In the control device for the continuously variable transmission mechanism for a vehicle according to claim 5.
The control means sets the time when the accelerator release operation is determined as the instruction hydraulic pressure start timing to the secondary pulley, and the timing when the delay time is provided from the instruction hydraulic pressure start time to the secondary pulley is the instruction hydraulic pressure start timing to the primary pulley. age,
A control device for a continuously variable transmission mechanism for a vehicle, characterized in that the ascending gradients of the indicated hydraulic pressures of the primary pulley and the secondary pulley have the same gradient. In the control device for the continuously variable transmission mechanism for a vehicle according to claim 6.
The control means is a control device for a continuously variable transmission mechanism for a vehicle, characterized in that the indicated hydraulic pressures of the primary pulley and the secondary pulley are given in stepped characteristics. In the control device for the continuously variable transmission mechanism for a vehicle according to any one of claims 1 to 7.
In the continuously variable transmission mechanism, the first target rotation speed of the primary pulley set when the accelerator opening is zero is higher than the second target rotation speed of the primary pulley set when the accelerator opening is extremely low. A control device for a continuously variable transmission mechanism for vehicles, which is characterized by being controlled by a shift map.