JP3322112B2 - Hydraulic control device for continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control device for a continuously variable transmission in a vehicle, and more particularly to a control device suitable for controlling the operating pressure in a belt type continuously variable transmission. .

[0002]

2. Description of the Related Art Continuously variable transmissions, such as a V-belt type continuously variable transmission and a toroidal type continuously variable transmission, include a continuously variable transmission having a transmission mechanism capable of continuously controlling a gear ratio. As a hydraulic control device for a type of continuously variable transmission, the present applicant has previously proposed a hydraulic control technology for controlling the operating pressure in such a continuously variable transmission according to Japanese Patent Application Laid-Open No. 61-105347 (Document 1). are doing.

[0003]

According to the above-mentioned proposal, taking a V-belt type continuously variable transmission as an example, a V-belt type continuously variable transmission that performs lock-up control, that is, a transmission system Lock-up that allows the torque converter inserted in the lock-up to be in a lock-up state in which the input and output elements of the torque converter are directly connected under the vehicle operating condition in the lock-up region where the torque increasing function and the torque fluctuation absorbing function are unnecessary. The minimum value of the line pressure used for the hydraulic pressure of the V-belt transmission mechanism can be matched with the required minimum value of the fluid transmission device by the torque converter, even in the operation pressure (line pressure) control of the continuously variable transmission of the formula, It is possible to reduce the load on the oil pump, etc., and to provide effective means for improving the efficiency of the continuously variable transmission (FIGS. 2 and 3 of Document 1).

By the way, such a proposal is useful in the above point. However, considering the following aspects, the line pressure control has a problem in optimizing the line pressure at the time of lock-up ON. There is still room for improvement.

FIG. 3 is a diagram which will be referred to also in the following description.
(Throttle opening) This is a characteristic diagram in the vicinity of the shift line, and shows how an inertia torque occurs due to a decrease in engine speed when switching to lock-up ON. In the case of a vehicle equipped with a continuously variable transmission in which lock-up control is introduced, when lock-up is turned on by the lock-up control, the engine speed drops. At that time, an inertia torque occurs for the rotation. Therefore, when the lock-up is on, the hydraulic pressure tends to be insufficient. On the other hand, in a hydraulically operated V-belt transmission mechanism in a V-belt type continuously variable transmission, a V-belt is wound around both input and output pulleys to realize a continuously variable transmission by changing a pulley transmission ratio. As described above, when the hydraulic pressure at the time of lock-up is slightly insufficient, the belt may easily slip. Slip in a speed change mechanism such as a V-belt transmission mechanism in a continuously variable transmission also affects power transmission and the like.

Therefore, if it is not possible to cope with the occurrence of the inertia torque due to the engine rotation drop when the lock-up is on, the continuously variable transmission incorporating the lock-up control ensures the optimum line pressure. Although it is difficult, the above-mentioned proposal does not have a function such as optimizing the operating pressure in the case of lock-up on such lock-up control, and considers such a point of lock-up on. It has not been.

The present invention has been improved in view of the above, and in controlling the operating pressure of a belt-type continuously variable transmission having lock-up control, an optimum operating pressure can be obtained even when lock-up is on. It is an object of the present invention to realize an operating pressure control of a continuously variable transmission that can prevent the occurrence of slippage or the like in a transmission mechanism. Another object is to perform an operating pressure increase correction control for increasing the operating pressure by a correction value corresponding to an inertia torque generated at the time of lock-up,
An object of the present invention is to provide a hydraulic control device for a continuously variable transmission in which further improvements and improvements are added so as to be able to be executed more effectively and to appropriately realize the above.

[0008]

According to the present invention, the following hydraulic control apparatus for a continuously variable transmission is provided. That is, the lock-up clutch can control the lock-up state in which the input / output elements are directly connected, and can control the operating pressure used for the hydraulic operation of the speed change mechanism capable of continuously controlling the speed ratio. A hydraulic control device for a step transmission, comprising: means for determining switching to lock-up on in the lock-up control; and means for performing correction correction control of the operating pressure when lock-on is determined by the means. The operating pressure increase correction is performed by increasing the operating pressure with a correction value corresponding to an inertia torque generated by a decrease in the engine speed when the lock-up is turned on. It is.

In the above, the control for increasing the working pressure is performed by applying a correction torque value for correcting an inertia torque to an estimated engine torque value obtained from the engine operation parameters. This is performed by obtaining a required operating pressure value corresponding to the estimated input torque value obtained as a result. In the control for increasing the operating pressure, a correction value to be applied is:
It can be changed according to the throttle opening or its equivalent value.

[0010] Further, there is further provided a means for controlling the control for increasing the operating pressure until a predetermined time has elapsed after the lock-up ON, and after the predetermined time has elapsed,
The operating pressure increase correction control is prohibited.
It is characterized by the following. Further, the speed change mechanism of the continuously variable transmission controls a speed ratio by changing a pulley transmission ratio by a belt transmission mechanism.

[0011]

According to the present invention, in the lock-up control of the continuously variable transmission, the lock-up clutch can be controlled to a lock-up state in which the input / output elements are directly connected to each other, and the lock-up is turned on. Can continuously control this by the speed change mechanism, and the operating pressure used for the hydraulic operation of the speed change mechanism is controlled. When switching to lock-up ON in lock-up control is determined, and lock-on is determined, control for increasing the operating pressure is performed. Here, the correction of the increase of the operating pressure is performed by increasing the operating pressure with a correction value corresponding to an inertia torque generated by a decrease in the engine speed when the lock-up is turned on. Therefore,
When the lock-up clutch is switched to lock-up on, where the lock-up that directly connects the input and output elements is performed, if there is no such control for increasing the operating pressure, the hydraulic pressure tends to be insufficient when the lock-up is on, resulting in continuously variable transmission. Slip can easily occur in the transmission mechanism of the machine, but this can be prevented, the operating pressure can be increased, and even if the lock-up is turned on by lock-up control, slip occurs in the transmission mechanism properly, An improved hydraulic control device for a continuously variable transmission that can prevent the accompanying effects from occurring beforehand and can obtain an optimal operating pressure even when lock-up is on in controlling the operating pressure of a continuously variable transmission having lock-up control. Can be realized. Further, when it is determined that the lock-up is on, when performing the increase correction control of the operating pressure, the increase of the operating pressure is corrected by a correction corresponding to an inertia torque generated by a decrease in the engine speed when the lock-up is on. If the operating pressure is increased with the value, the engine speed drops during lock-up ON, and even if an inertia torque occurs for that rotation at that time, it is possible to appropriately respond to this and the inertia torque is generated due to the rotation drop. Therefore, the working pressure can be increased, and the working pressure can be reliably increased by the amount of inertia torque.

In this case, preferably, the control for increasing the operating pressure is performed by estimating the operating pressure from an engine operating parameter such as an engine speed, a throttle opening, or a corresponding value thereof. A configuration in which a correction torque value for inertia torque correction is applied to the estimated engine torque value obtained as a result, and a required operating pressure value corresponding to the estimated input torque value obtained by the correction is obtained. The present invention can be implemented, and the above can be similarly realized. In this case, the operating pressure increase correction control for increasing the operating pressure by the correction value corresponding to the inertia torque generated at the time of lock-up ON can be executed more effectively, and further improvement and improvement can be achieved.

[0013] Preferably, as set forth in claim 3,
In the control for increasing the operating pressure, the correction value to be applied is:
The present invention can be implemented so as to be variable according to the throttle opening or its equivalent value, and the above can be realized similarly. In this case, it is also possible to control the increase in the operating pressure to be increased in accordance with the magnitude of the throttle opening at that time, thereby achieving more fine-grained correction control and further optimizing the operating pressure control. it can.
In a preferred embodiment, the engine torque is estimated by using the engine speed or its equivalent value and the throttle opening or its equivalent value, and the estimated engine torque is changed according to the throttle opening degree or the equivalent value obtained as a correction amount. With the correction mode in which the corrected torque is applied, the operating pressure increase control for correcting the lock-up on inertia torque can be performed as a simple and more suitable control.

Further, according to the present invention, the control for increasing the operating pressure is performed until the predetermined time elapses after the lock-up is turned on. The present invention can be suitably implemented as a configuration including the above, and the same can be realized similarly. In this case, the operating pressure increase correction control is a temporary operation when the lock-up is turned on, and the correction is applied only for the predetermined period. It is possible to control to release and prohibit, to respond to the occurrence of inertia torque due to engine rotation drop at lock-up on, and to properly increase the necessary operating pressure appropriately and properly,
It can be made more effective and further improvement and improvement can be achieved. Further, as described in claim 5, the present invention provides:
The transmission mechanism of the continuously variable transmission can be suitably applied to a belt-type continuously variable transmission that controls a gear ratio by changing a pulley transmission ratio by a belt transmission mechanism, and can realize the above in a similar manner. it can. In this case, even if the speed change mechanism of the continuously variable transmission that controls the speed ratio in a stepless manner is a belt transmission mechanism using such belts and pulleys, the belt tends to slip when the lock-up is on. The belt transmission can be reliably prevented, and when belt slippage occurs with this belt transmission mechanism, the effect on power transmission etc.
This is advantageous in that this can be reliably avoided.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an example in which a hydraulic control device according to an embodiment of the present invention is applied to, for example, a V-belt type continuously variable transmission (CVT). Here, the continuously variable transmission can be controlled to a lockup state in which the input / output elements are directly connected by a lockup clutch,
The present invention is a belt-type continuously variable transmission capable of controlling an operating pressure used for hydraulic operation of a V-belt transmission mechanism as a transmission mechanism capable of continuously controlling a gear ratio. In FIG. 1, the present belt-type continuously variable transmission includes a primary pulley 1 as an input pulley on the drive side to which engine rotation is transmitted, and a secondary pulley 2 as an output pulley that outputs rotation after shifting. Pulley 1 and secondary pulley 2
A transmission system (V
Belt transmission mechanism).

Although not shown, the transmission system of the transmission further includes a torque converter of a fluid transmission device for transmitting rotation from an engine of the vehicle, and a forward / reverse switching mechanism.
It is assumed that the rotation from the forward / reverse switching mechanism is input to the primary pulley 1 through the torque converter and the forward / reverse switching mechanism in order. The torque converter (T / C) has a hydraulically actuated lock-up clutch whose engagement and release is controlled by operating pressure. When the clutch is engaged, the torque converter (T / C) shifts from a fluid transmission state (converter state) to a state between the input and output elements. Directly connected transmission state (lockup state)
Shall be switched to

For this control, a known lock-up solenoid using a duty-controlled lock-up solenoid, a lock-up control valve (hydraulic control valve), or the like can be used, and the lock-up control system includes these lock-up solenoids, It can be configured to include a lock-up control valve and a hydraulic control system of a lock-up clutch.

The V-belt transmission mechanism includes a primary pulley 1
Is transmitted to the secondary pulley 2 via the V-belt 3. The V-belt continuously variable transmission has two pulleys 1,
By changing the diameter of the winding arc of the V belt 3 with respect to 2, the transmission ratio between pulleys, that is, the gear ratio can be changed steplessly. Here, primary pulley 1 and secondary pulley 2
The V-belt 3 wound around the V belt 3
If the working pressure acting on the belt transmission mechanism is appropriate, the V-belt 3 will not slip and therefore the primary pulley 1
Power is transmitted from the side to the secondary pulley side via the V-belt 3 at a predetermined gear ratio under gear change control.

In order to enable such a continuously variable transmission, the primary pulley 1 enables the movable flange 1b which forms the pulley V-groove to face the fixed flange 1a to be displaceable in the axial direction. The movable flange 2b which forms the pulley V-groove opposite to 2a can be displaced in the axial direction. Then, by the action of the shift control pressure P _S in the direction toward the stationary flange 1a to the movable flange 1b, by applying a line pressure P _L in a direction towards the fixing flange 2a to the movable flange 2b, the shift control pressure P _S and the line The stepless speed change is performed by changing the diameter of the arc around which the V belt 3 is wound around both the pulleys 1 and 2 steplessly in accordance with the pressure difference from the pressure P _L.

[0020] Here, in explaining the shift control system, which includes a shift control valve 21 for determining the shift control pressure P _S, the shift link 22 is constituted by a step motor 23. The speed change link 22 has one end connected to the primary pulley movable flange 1.
The other end is connected to a shifter 24 which is displaced together with b, the other end is connected to be rotated by a step motor 23, and the both ends are pivotally connected to the spool 21 a of the shift control valve 21. Here, the shift control valve 21 is intended to produce a shift control pressure P _S in the circuit 25 the circuit 26 the line pressure P _L from the (line pressure circuit) in vacuo (shift control pressure circuit) as the working pressure circuit, when the spool 21a is raised in the figure, when increasing the speed change control pressure P _S through the shift control pressure circuit 26 to the line pressure circuit 25 is lowered in FIG spool 21a, the shift control pressure circuit 26
To the drain port 21b to reduce the shift control pressure P _S, and the stroke of the spool 21a is controlled by the step motor 23 via the shift link 22. The rotational position of the step motor 23 is determined by the controller 17, and the speed change control is thereby executed.

On the other hand, the line pressure control system for controlling the line pressure P _L provided for shifting as described above,
This has the following configuration. The line pressure control system supplies the pressure source 11 and the hydraulic oil to be supplied to the line pressure P _L
And a pressure regulator valve 12 for regulating the pressure. Also it has a pressure modifier valve 13 for supplying the modifier pressure P _m of the line pressure control to the pressure regulator valve 12. Then, it provided the line pressure solenoid 14 for controlling such pressure modifier valve 13, a pilot valve 15 for supplying a constant pressure P _C (lower pressure than the line pressure) to the solenoid (solenoid valve).

The pressure regulator valve 12 has a pressure
Leakage of hydraulic fluid from source 11 into circuit 16
While draining from drain port 12a as necessary,
Fire pressure P_mLine pressure P according to_LAdjust the pressure. So
The pilot valve 15 keeps the oil leaking from the circuit 16 constant.
Pressure P_CAnd supply it to the line pressure solenoid 14,
The pressure solenoid 14 has a constant pressure P_CTo the drive duty D
Duty pressure P_DAnd mark the modifier valve 13
Add. The modifier valve 13 detects oil leaking from the circuit 16.
Is the duty pressure P_DAnd therefore the line pressure solenoid 14
Modifier according to drive duty (DUTY) D
Pressure P_mTo the pressure regulator valve 12.
Apply and line pressure P_LTo the above control. Therefore,
In pressure P _LIs the drive duty of the line pressure solenoid 14
D can be controlled by increasing or decreasing D.
Dynamic duty D must be determined by controller 17
And

The step motor 23, the line pressure solenoid 14, and the T / C lock-up (L /
U) The lock-up solenoid for control is electronically controlled by a controller 17, which has a signal from a vehicle speed sensor 18 for detecting a vehicle speed VSP,
A signal from a throttle (TH) opening sensor 19 for detecting the engine throttle opening TVO is input. Also,
The controller 17 includes an engine (ENG) here.
A signal from the ENG rotation sensor 41 for detecting the rotation speed Ne, a signal from the Pri rotation sensor 42 for detecting the primary (Pri) rotation speed Npri on the primary pulley 1 side, and the like are input.

The controller 17 controls the motor 23, the line pressure solenoid 14, and the lock-up solenoid to drive control signals (step motor drive command, line pressure control command, L
/ U control command) or the like, and based on the input information, executes shift control via the step motor 23 and L / U control by engaging and disengaging the lock-up clutch. Line pressure solenoid 1
The control for the line pressure is executed via the control unit 4 and the control for the correction of the line pressure under a certain condition.

As for the shift control, the controller 17 controls the line pressure of the transmission by driving the line pressure solenoid 14 in accordance with the solenoid drive duty D determined as will be described later. I do. In the shift control, the controller 17 uses, for example, a map (see FIG. 3) corresponding to a predetermined shift control characteristic to input a target input from the vehicle speed VSP and the throttle opening TVO from the sensors 18 and 19. The number of rotations N is obtained, and the target rotation position of the step motor 23 corresponding to this is instructed to the motor 23 as a step motor command value.
Here, the step motor 23 is driven to the target rotation position described above, whereby the step motor 23
Is rotated around the shifter 24 to move the shift control valve spool 21a to the corresponding position. As a result, the shift control valve 21 changes the shift control pressure P _S ,
The gear ratio is brought to a gear ratio corresponding to the target input rotation speed N by displacing the two movable flanges 1b and 2b.

As the shift progresses, the movable flange 1b of the primary pulley 1 rotates the shift link 22 via the shifter 24 around the step motor 23 to return the shift control valve spool 21a to the original stroke position.
When the speed ratio reaches the speed ratio corresponding to the target input rotation speed N, the speed change control ends, and the speed ratio can be maintained.

For the lock-up control, for example, the control region is determined to be in operation in a lock-up region where a torque increasing function or the like is unnecessary or in a converter region where it is necessary. Drive control of the lock-up solenoid according to the T / C in the lock-up area
Can be controlled so as to bring the T / C into the converter state (UNL / U) by releasing this in the converter area (L / U on) and releasing it in the converter area (L / U off). .

In controlling the line pressure P _L ,
The controller 17 basically obtains a target line pressure P _L value based on a preset line pressure control characteristic according to the gear ratio and the throttle opening TVO, and sets a drive duty D corresponding to the target line pressure P _L to a target value. By instructing the solenoid 14 as a pressure control command value, line pressure control can be executed. In this case, the line pressure solenoid 14
It is applied to the modifier valve 13 and the duty pressure P _D and constant pressure P _C in accordance with the drive duty D from the pilot valve 15, modifier valve 13 pressure regulator modifier pressure P _m corresponding to the duty D Apply to valve 12. Thus, the pressure regulator valve 12, the hydraulic oil from the pressure source 11, by regulating the line pressure P _L corresponding to the designated drive duty D, thereby the line pressure P _L along a predetermined line pressure control characteristics Controlled. Further, in the line pressure control, the controller 17 also executes a line pressure correction control so as to correct (increase) the line pressure P _L so as to appropriately compensate for the lack of hydraulic pressure at the time of L / U ON. .

FIG. 2 is a block diagram showing an example of the functions of the system of the embodiment shown in FIG. 1 for controlling the line pressure and making such a correction. The controller 17
The line pressure control including the correction process is executed by the process represented by the functional block diagram or by executing a corresponding program. In the figure, a to g are T / C speed ratio calculations, T / C
C torque ratio calculation, ENG torque estimation, actual gear ratio calculation, input torque estimation, required line pressure calculation, and means for converting line pressure (P _L ) -DUTY (line pressure solenoid drive duty D), respectively. i represents a means for line pressure increase correction control.

In the processing of the controller 17, in this example, the throttle (TH) opening data TVO, the ENG rotation speed Ne, the Pri rotation speed Npri, the secondary (Sec) rotation speed Nsec on the secondary pulley 2 side, and L / U It is assumed that a flag or the like is used as input information, and a process of reading these is included. The information on the Sec rotation speed can be obtained by having a Sec rotation sensor and inputting a signal from the Sec rotation sensor to the controller 17, but the Sec rotation speed may be based on information from the vehicle speed sensor 18. The L / U flag is flag information indicating the ON / OFF state of the L / U in the L / U control separately executed in the controller 17, and includes an input torque estimating unit e and a correction control unit i. Is input to

The T / C speed ratio calculation unit a calculates the ENG rotation speed N
From the e and Pri rotation speed Npri, the T / C speed ratio is calculated by the speed ratio = Ne / Npri. Then, the T / C torque ratio calculation unit b obtains a torque ratio corresponding to the calculated speed ratio based on a characteristic map as exemplified in the figure. On the other hand, the ENG torque estimating unit c estimates and obtains the ENG torque by calculation based on the engine operating parameters. Here, the ENG rotation speed Ne is calculated based on a map corresponding to a characteristic illustrated in the figure. And the ENG torque is estimated from the TH opening data TVO (0/8 to 8/8). Further, the parameters used here may be equivalent values other than those.

Then, the input torque estimating unit e determines the value of the T / C torque ratio and the estimated ENG torque obtained as described above, furthermore, the L / U flag information of the L / U control, and the N / A The input torque is obtained as follows based on the information indicating that the vehicle is in the range (neutral range). That is, the input torque is UNL / U (L / UOF).
F) If T / C is in the converter state, input torque = E
NG torque × torque ratio
When T / C is in the L / U state at the time of U (L / UON), input torque = ENG torque is obtained, and in the case of N range, input torque = 0.

The required line pressure calculating section f calculates the required line pressure value from the actual gear ratio and the input torque value. Basically, the required line pressure value and the input determined and given by the engine torque estimating section c are basically used. The required line pressure value to be targeted is calculated from the torque value. Here, the actual speed ratio (the transmission ratio between the pulleys) is calculated by the actual speed ratio calculation unit d in the Pri rotation speed Np.
speed ratio = Nsec / N from ri and Sec rotation speed Nsec
It shall be calculated by pri. The required line pressure calculating unit f calculates the required line pressure from the calculated speed ratio value and the input torque value based on a line pressure control characteristic map as illustrated in the figure defined by the speed ratio and the input torque. Is calculated, and a line pressure-DUTY conversion unit g calculates a DUTY value corresponding to a given line pressure value in accordance with a conversion characteristic as shown in the figure, and determines this as a drive duty D for instructing the line pressure solenoid 14. Thus, the line pressure can be controlled.

Here, in the present embodiment, the above-described line pressure increase correction further applied to the line pressure control is estimated by the input torque estimating unit e as described above as shown in FIG. An example is shown in which the input torque value applied to the calculation by the calculation unit f is corrected by the correction control unit i. The correction control unit i is L
/ UON for inertia torque correction.
As shown in the example, when the lockup for directly connecting the input / output elements is performed by engaging the lockup clutch of T / C,
Although ENG rotating drops, in which the revolution inertia torque causes a correspondingly line pressure P _L up to occur at that time.

In the line pressure increase control, the correction control unit i obtains a necessary correction amount such that the line pressure P _L is correspondingly increased in oil pressure. In this example, a correction torque as a control amount applied to the input torque correction is obtained, and a correction torque is obtained from the engine throttle opening TVO at that time based on a predetermined characteristic map as illustrated in the figure. This is for determining the torque value. Here, the value for the L / UON inertia torque correction is based on the TVO value, and the magnitude of the correction torque is set in accordance with the magnitude of the throttle opening TVO. Therefore, here, the correction torque value to be applied is read out based on the detected throttle opening TVO and according to the map data of the characteristic tendency. And
The sum of this and the estimated input torque value from the input torque estimating unit e is applied to the calculation in the required line pressure calculating unit f.

As a result, in this case, when correcting the line pressure,
In the required line pressure calculation unit f, the estimated input torque when the T / C is in the L / U state = the estimated ENG torque component (E
NG torque estimation unit c) as a basic value, and an input torque value corrected by adding a correction torque value of the above inertia torque correction to the basic value.

## EQU00001 ## Based on the input torque value obtained from the corrected input torque value = basic value + correction amount = estimated ENG torque value + corrected torque value, the line pressure value is calculated using the map. Thus, in the line pressure-DUTY conversion unit g, the drive duty D corresponding to the calculated line pressure value is instructed to the line pressure control solenoid 14, and even though the inertia torque is generated due to the rotation drop. Corresponding line pressure P _L
Can be increased.

Therefore, when the line pressure control at the time of switching to L / UON is not considered, the hydraulic pressure at the time of L / UON tends to be insufficient, as described above, and therefore, the V-belt transmission mechanism However, in this line pressure control, even if the transmission mechanism of the continuously variable transmission is the V-belt transmission mechanism, the line pressure P _{L is} surely secured by the amount of inertia torque as described above. And the slippage of the V-belt 3 between the pulleys 1 and 2 can be appropriately prevented even during L / U ON.

Further, such a line pressure increase correction control according to the present invention is carried out so that, for example, a necessary correction is applied to the calculated line pressure value obtained by the required line pressure calculation unit f at the control amount stage. This can be executed in a mode in which the line pressure P _L can be increased by correcting the control amount. However, as in the present embodiment, the ENG rotation speed N
e and the estimated ENG torque from the throttle opening TVO,
By applying a correction torque corresponding to the throttle opening TVO obtained as a correction amount to this to perform line pressure increase control for L / UON inertia torque correction, a simpler and more preferable one is obtained. Becomes The correction torque value itself, when there was set up to vary depending on the size of the throttle opening TVO, increase also controls the time of the throttle opening TVO of the line pressure to also be up to match the magnitude P _L As a result, finer correction control can be realized, the line pressure control can be further optimized, and further improvements and improvements can be made to those proposed above.

Preferably, the line pressure increase correction control is performed temporarily at the time of L / UON, and the correction amount (correction torque value or the like) is set at a predetermined time t1 after inputting the L / UON signal.
(For example, for about 1 second) and then apply L
This correction control is performed to prohibit such correction even during the continuation of the / U state. In the present example, this is also the case, and the correction control unit i obtains the period of the predetermined time t1 from the timing of switching to L / UON based on the L / U flag in the correction torque-TVO map of the illustrated characteristics. Outputs the correction value, otherwise outputs a value of zero.

FIG. 4 shows an L / U which can be executed by the controller 17 and includes the above-described prohibition control.
7 is an example of a program flowchart of a correction amount calculation routine for correcting an inertia torque component in the ON-time line pressure increase control. In the figure, in step S101, L / UON is checked. Here, in this step, the content of monitoring whether or not switching to L / UON can be performed using the L / U flag.

If the result of the check in step S101 is No, in this example of the program, the following L /
The timer for measuring the elapsed time after the UON switching is reset, the correction amount is set to a value of 0, and the routine ends (steps S106 and S107). Here, in the case where the line pressure control including the correction control is based on the example of FIG. 2 described above, the input torque value itself obtained by the input torque estimating unit e is applied to the necessary line pressure calculating unit f. hand,
The line pressure control will be executed (normal line pressure control).

Then, the answer in step S101 is Yes.
, It is determined that L / UON has occurred. In this case, in step S102, for example, first, a correction torque is calculated based on the correction torque-TVO map of FIG.
A correction amount for N inertia torque is obtained, and in step S103, L / UON is compared with the timer value.
Thereafter, it is monitored whether or not a predetermined time t1 has elapsed.
If it has not elapsed, the correction amount is set to the correction torque value obtained in step S102, and the routine ends (step S104). On the other hand, in the line pressure control, the correction amount can be read out in step S104 and the correction control can be executed. As a result, in this case, the correction torque of the map data is displayed in the second term on the right side of the equation. the value is applied, therefore, as described above, it is possible to perform the line pressure control is up the line pressure P _L as intended (L / U
ON-time line pressure increase correction control).

On the other hand, if it is determined that the predetermined time t1 has elapsed, thereafter, step S103 is executed at step S103.
The 105 side is selected, the correction amount is set to a value of 0, the step S104 is executed, and this routine ends. In this case, in the line pressure control, the value 0 is applied to the second term on the right side of the equation. As a result, in the subsequent L / U state, in the necessary line pressure calculation unit f, the input torque = the estimated ENG torque itself is applied, and the required line pressure value that conforms to this is calculated. The pressure control can be executed without hindrance (line pressure increase correction control prohibition control).

Thus, this line pressure increase correction control can be performed only for a predetermined period of, for example, about 1 second after switching to L / UON, and thereafter the correction is canceled and prohibited. Control. By doing so, it is possible to cope with the occurrence of an inertia torque due to a drop in ENG rotation during L / UON, and to appropriately increase the necessary line pressure in accordance with the inertia torque. Become.

The present invention is not limited to the above embodiment and the like. For example, although a V-belt type continuously variable transmission as shown in FIG. 1 is taken as an example, the present invention is not limited to this, and may be applied to a toroidal type or the like. Further, the method of controlling the line pressure as the operating pressure is not limited to the method shown in FIG.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a shift control system, a line pressure control system, and the like of a V-belt continuously variable transmission including a hydraulic control device according to an embodiment of the present invention;
It is a system diagram showing an example of an L / U control system and the like.

FIG. 2 is a functional block diagram illustrating an example of line pressure control including control of line pressure correction in the same example.

FIG. 3 is a characteristic diagram for describing generation of inertia torque due to a drop in ENG rotation speed Ne.

FIG. 4 is a flowchart illustrating an example of a correction amount setting program executed by a controller for correcting an inertia torque when a lock-up is ON.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary pulley 1b Movable flange 2 Secondary pulley 2b Movable flange 3 V belt 11 Pressure source 12 Pressure regulator valve 13 Pressure modifier (PMF) valve 14 Line pressure solenoid 15 Pilot valve 17 Controller 18 Vehicle speed sensor 19 Throttle opening sensor 21 Shift control Valve 22 Transmission link 23 Step motor 24 Shifter 25 Line pressure circuit (operating pressure circuit) 26 Transmission control pressure circuit 41 Engine (ENG) rotation sensor 42 Primary (Pri) rotation sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (5)

(57) [Claims] An operating pressure used for hydraulic operation of a transmission mechanism that can be controlled to a lockup state in which an input / output element is directly connected by a lockup clutch and that can control a gear ratio steplessly. A hydraulic control device for a continuously variable transmission, comprising: means for judging switching to lock-up ON in the lock-up control; and Means for performing an increase in the operating pressure, wherein the operating pressure is increased with a correction value corresponding to an inertia torque generated by a decrease in the engine speed when the lock-up is turned on. Hydraulic control device for a continuously variable transmission. 2. The control for increasing the operating pressure includes a correction torque value for correcting an inertia torque component with respect to an estimated engine torque value obtained by estimating from an engine operation parameter including a throttle opening or a corresponding value thereof. The hydraulic control device for a continuously variable transmission according to claim 1, wherein the control is performed by obtaining a required operating pressure value corresponding to an estimated input torque value obtained by performing the correction. 3. In the control for increasing the operating pressure,
The hydraulic control device for a continuously variable transmission according to claim 1 or 2, wherein the correction value to be applied can be changed according to the throttle opening or its equivalent value. 4. A control device for controlling the operation pressure to be increased until a predetermined time has elapsed after lock-on, and after the predetermined time has elapsed, the operation pressure increase correction control is performed. The hydraulic control device for a continuously variable transmission according to any one of claims 1 to 3, wherein the hydraulic pressure control is prohibited. 5. The speed change mechanism according to claim 1, wherein the speed change mechanism of the continuously variable transmission controls a speed ratio by changing a pulley transmission ratio by a belt transmission mechanism. Hydraulic control device for step transmission.