JP2000046173A - Line pressure control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a line pressure control device for automatic transmissions that effects engine-speed-based line pressure switching control establishing compatibility between noise/vibration and hydraulic performance. SOLUTION: The line pressure of a continuously variable transmission(CVT) is determined according to the higher one of a CVT-required oil pressure PCVT and a clutch-required oil pressure PCLU for low engine speed and according to the highest one of the CVT-required oil pressure PCVT, the clutch-required oil pressure PCLU and a lubrication-required oil pressure PLUB for high engine speed. These required oil pressures are basically determined in dependence upon input torque, and the line pressure is determined, for low engine speed, in consideration of the CVT- and clutch-required oil pressures PCVT and PCLU, not the lubrication-required oil pressure PLUB causing an unnecessary increase in noise and vibration, and for middle and high engine speed, in consideration of the lubrication-required oil pressure PLUB to establish compatibility between noise/vibration and hydraulic performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line pressure control device for controlling a line pressure in an automatic transmission including a continuously variable transmission.

[0002]

2. Description of the Related Art Including a continuously variable transmission (CVT) represented by a V-belt type continuously variable transmission and a toroidal type continuously variable transmission.
In an automatic transmission mounted on a vehicle, a hydraulic source (pressure source) including a line pressure control system such as an oil pump and a pressure regulating valve is:
Various elements that require oil supply in the transmission mechanism,
Supply the required oil (including lubricating oil) to the mechanism.

[0003]

In such a line control system, when setting the line pressure, a hydraulic pressure is generated to correspond to the input torque of the transmission, and the line pressure is increased in accordance with the input torque. An apparatus has been proposed (for example, JP-A-8-28646 (Document 1)).
According to this, it is possible to set the line pressure corresponding to the input torque. Even in the case of a toroidal type continuously variable transmission in which the supply of lubricating oil to the transmission mechanism is also an important factor, it is possible to realize a line pressure control device compatible with input torque by applying this.

By the way, in the case of the line pressure setting corresponding to the input torque, when the line pressure is set, the vehicle (automobile)
Considering the aspects of sound and vibration that affect the quietness and comfort of the vehicle, the following can be said.

FIG. 6 is a consideration diagram referred to also in an embodiment of the present invention, which shows the relationship between input torque, line pressure (line pressure corresponding to input torque), and pump noise (oil pump noise of the unit). According to this, when depending on the method of setting the line pressure in accordance with the input torque, the line pressure can be set higher as the transmission input torque is larger, while the line pressure and the pump noise are not shown. Because of the relationship, as the line pressure is set higher, pump noise (sound vibration) increases.

When the line pressure is set to be low in terms of sound vibration, it is possible to satisfy the requirement of reducing the pump noise. But,
The line pressure is controlled to be low, and as a result, it is difficult to satisfy the requirement in terms of required hydraulic pressure (hydraulic performance) such that a higher transmission torque is required to be higher in accordance with the transmission input torque. .

[0007] In particular, in the case of a toroidal continuously variable transmission described in Patent Document 1, for example, where importance is attached to necessary and appropriate supply of lubricating oil and line pressure control is required in accordance therewith,
It is difficult to achieve both the sound vibration and the hydraulic performance including the supply of the lubricating oil, and the higher the set hydraulic pressure is, the more difficult it is to deal with.

Therefore, it is desirable that both sound vibration and hydraulic performance be compatible. Desirable is also the line pressure control in a transmission unit having a high set hydraulic pressure, which enables the above-described correspondence, or the line pressure control in a continuously variable transmission in which an appropriate supply of lubricating oil is particularly important. In addition, it is possible to achieve both sound vibration and hydraulic performance, or the feature of the line pressure setting corresponding to the input torque is to make sound vibration and hydraulic performance compatible while utilizing this.

SUMMARY OF THE INVENTION The present invention is based on the above-mentioned considerations and the following considerations, and seeks to make improvements in these respects. The present invention provides an automatic vibration control system capable of achieving both sound vibration and hydraulic performance. It is an object of the present invention to provide a transmission line pressure control device. Another object of the present invention is to provide a line pressure control device capable of achieving both sound vibration and hydraulic performance even in line pressure control in a continuously variable transmission in which an appropriate supply of lubricating oil is particularly important.

[0010]

According to the present invention, there is provided the following automatic transmission line pressure control apparatus. That is, the present invention is a control device that controls a line pressure in an automatic transmission that has a transmission mechanism and is configured to include a hydraulically actuated friction element, and that shifts and transmits rotational power from an engine, A determining means for determining whether the engine speed is in a low rotation range lower than the predetermined value or in a high rotation range higher than the predetermined value; and A means for controlling the line pressure based on the determination result, in the case of the high rotation range, considering lubricating oil to be used for lubrication of the transmission mechanism,
The first required oil pressure determined as the required lubricating oil pressure required to supply the lubricating oil is compared with at least the second required oil pressure determined as the friction element required oil pressure required for the hydraulic operation of the friction element. , Set the line pressure according to the higher required hydraulic pressure, when the low rotation range,
A line pressure control unit including a line pressure determination unit for determining a line pressure so that the line pressure can be set according to the request for the second required oil pressure irrespective of the first required oil pressure. Of the automatic transmission.

When the speed change mechanism is a continuously variable transmission mechanism, and the line pressure control means determines that the engine speed is in the low rotational speed range, the line pressure control means controls the continuously variable transmission by the continuously variable transmission mechanism. The third required hydraulic pressure required as the hydraulic pressure required to be supplied as the control pressure to be supplied to the second hydraulic pressure is compared with the third required hydraulic pressure, and the line pressure is set according to the higher required hydraulic pressure. Means for determining a line pressure, wherein in the case of the high rotation speed range, the third required hydraulic pressure is further applied as a comparison target, and the first required hydraulic pressure, the second required hydraulic pressure, Comparing the third required oil pressure with the third required oil pressure and determining the line pressure so as to set the line pressure in accordance with the highest required oil pressure. is there.

The determining means uses a first predetermined value and a second predetermined value which is larger than the first predetermined value as the predetermined value for the determination. A line pressure setting characteristic set in a low first engine speed range in which the engine speed is equal to or lower than the first predetermined value, and a line pressure setting characteristic set in a high engine speed range in which the engine speed is equal to or higher than the second predetermined value. In contrast to the line pressure setting characteristic, the line pressure set in the third engine rotation range where the engine speed is between the first predetermined value and the second predetermined value does not rapidly change the line pressure control characteristic. A line pressure control device for an automatic transmission, further comprising means for determining a line pressure so as to set the line pressure.

In the third engine speed range, the line pressure is set such that the line pressure control characteristic is not suddenly changed. Applying an interpolation value obtained by a linear interpolation operation using each set value of the line pressure set value set in the second engine speed range, the first engine speed range and the second engine speed range A line pressure control device for an automatic transmission, wherein a line pressure between the lines is set.

Further, all or a part of the required hydraulic pressure to be set for the line pressure is a hydraulic pressure obtained by obtaining a required hydraulic pressure value in accordance with a transmission input torque. Machine line pressure control device.

[0015]

According to the line pressure control device of the present invention, the control range is divided into the low engine speed range and the high engine speed range, and the line pressure switching control according to the present invention is performed, thereby achieving both sound vibration and hydraulic performance. , Line pressure switching control based on the engine speed can be realized.

According to the first aspect, in the case of a high rotation range higher than a predetermined engine speed, the required oil pressure (first required oil pressure) determined as the oil pressure required for lubrication in consideration of the lubricating oil, and at least the friction element By comparing the required hydraulic pressure (second required hydraulic pressure) obtained as the required hydraulic pressure, the line pressure can be set in accordance with the higher required hydraulic pressure, and the required hydraulic performance in this area can be secured. In the low rotation range, regardless of the required lubrication required oil pressure, without unnecessarily increasing the noise and vibration, and when the friction element required oil pressure is required, the necessary line pressure is also adjusted accordingly. Make it possible to set it reliably.

Here, when setting the line pressure, lubrication is not taken into consideration in the low rotation speed range. However, when the engine is running at a low speed (for example, about 2000 rpm or less), little heat is generated in the transmission mechanism to which lubricating oil is supplied. Therefore, even if the required lubrication oil pressure is low, there are fewer problems compared to high rotation speeds, and
In view of the above-described considerations, the present invention more advantageously works on the effect of the reduction of the sound vibration when viewed from the relationship between the line pressure and the sound vibration (oil pump noise of the unit). According to the present invention, it is possible to easily cope with line pressure control in a transmission unit having a high set hydraulic pressure, and it is suitable for application to any of a stepped automatic transmission and a continuously variable transmission.

In this case, according to the second aspect, the continuously variable transmission which can achieve both sound vibration and hydraulic performance even in line pressure control in a continuously variable transmission in which appropriate supply of lubricating oil is particularly important. That is suitable for the line pressure control can be realized. In this case, if it is determined that the engine speed is in the low rotation range, the required hydraulic pressure (third required hydraulic pressure) determined as the required hydraulic pressure to be supplied as the control pressure used for the control of the continuously variable transmission and the friction element In comparison with the required oil pressure, the line pressure can be appropriately determined so that the line pressure is set according to the higher required oil pressure. As a result of a comparison between the three required oil pressures (the first required oil pressure, the second required oil pressure, and the third required oil pressure) of the lubrication required oil pressure and the friction element required oil pressure, according to the highest required oil pressure among them The line pressure can be appropriately determined to set the line pressure, and the sound vibration and hydraulic performance (the first required hydraulic pressure, the second required hydraulic pressure,
(The required hydraulic pressure) and the third required hydraulic pressure).

In particular, in the case of a toroidal type transmission unit having a power roller and an input / output cone disk, the power roller needs to pinch the input / output cone disk with a strong force, and a power that frictionally contacts the input / output cone disk. The roller is required to supply a necessary and appropriate lubricating oil, but the required hydraulic performance including the supply of the lubricating oil is also smaller than that of the roller not adopting the present invention, and the line pressure corresponding to the engine rotation speed according to the present invention is improved. By adopting variable control, it is also possible to achieve a balance between sound vibration and altitude.

In the case of the third aspect, the engine rotation range between the first predetermined value and the second predetermined value for the discrimination (the third rotation speed) is determined.
In the engine rotation range, the line pressure can be controlled by setting the line pressure so that the line pressure control characteristic does not suddenly change, and a stepwise change in the sound and vibration characteristics can be avoided. In addition, it is possible to set the line pressure control characteristics according to the engine speed, and it is possible to achieve a higher degree of compatibility between sound vibration and hydraulic performance.

In this case, according to the present invention, the sound and vibration characteristics are not changed stepwise, and, for example, as shown on a straight line connecting the points a and b illustrated in FIG. And a line pressure control characteristic that changes linearly, thereby making it possible to achieve a more effective one.

According to the fifth aspect, the required oil pressure can be basically determined by the input torque of the transmission, and the characteristics of the line pressure setting corresponding to the input torque can be utilized to achieve both sound vibration and hydraulic performance. Therefore, for example, in the case of a continuously variable transmission, at the time of low engine rotation, the line pressure originally required by the friction element required hydraulic pressure and the required hydraulic pressure for the continuously variable transmission control can be appropriately changed according to the input torque. .

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1, 2 and 3 illustrate an automatic transmission having a line pressure control device according to an embodiment of the present invention, and FIG. 1 is a system configuration diagram. In FIG. 1, 100
Denotes an engine of the vehicle, 200 denotes a transmission to which power is input via a torque converter, and 250 denotes an output shaft.

When the transmission 200 is a continuously variable transmission, it includes a torque converter 201, a forward / reverse switching mechanism including a forward / reverse clutch as a friction element,
The control unit 210 includes a toroidal continuously variable transmission mechanism and the like.
May include a hydraulic circuit having a line pressure solenoid 215 for line pressure control according to the present invention, in addition to a shift control valve, an actuator, and the like constituting shift control means.

FIG. 2 is a vertical sectional side view of an applicable toroidal type continuously variable transmission, and FIG. 3 is a vertical sectional front view of the same.
Although not shown in FIG. 2, a forward / reverse switching mechanism is disposed on the right side in the figure as a front stage, and a torque converter 201 is further disposed at a front stage thereof. Engine power is supplied to the torque converter 201 and the forward / backward switching mechanism. It is transmitted in order.

First, a toroidal transmission unit, which is a main part of the continuously variable transmission, will be described. The toroidal transmission unit has an input shaft 20 to which rotation from the engine 100 is transmitted, and this input shaft is clearly shown in FIG. An end remote from the engine 100 is rotatably supported in a transmission case 21 via a bearing 22, and a center portion is mounted in an intermediate wall 23 of the transmission case 21.
4 and a hollow output shaft 25 so as to be rotatable. The input and output cone disks 1 and 2 are rotatably supported on the input shaft 20, and the input and output cone disks are arranged such that the toroidal curved surfaces 1a and 2a face each other.
A pair of power rollers 3 disposed on both sides of the input shaft 20 with the input shaft 20 interposed therebetween are interposed between the opposed toroid curved surfaces of the input and output cone disks 1 and 2, and these power rollers are interposed between the input and output cone disks 1 and 2. The following configuration is adopted for clamping.

That is, a loading nut 26 is screwed into the end of the bearing (22) of the input shaft 20, and a cam disk 27 which is locked by the loading nut and is rotationally engaged with the input shaft 20; A loading cam 28 is interposed between the first toroidal curved surface 1a and the end surface far from the toroidal curved surface 1a, and rotation from the input shaft 20 to the cam disk 27 is transmitted to the input cone disk 1 via this loading cam. Here, input cone disk 1
Is transmitted to the output cone disk 2 via the rotation of both power rollers 3, and during this transmission, the loading cam 28 generates a thrust proportional to the transmission torque, and moves the power roller 3 between the input and output cone disks 1 and 2. Compress pressure to enable the above power transmission.

That is, the power roller 3 is pinched between the input and output cone disks 1 and 2, and the oil film is sheared between the power roller 3 and the input and output cone disks 1 and 2 so that the power roller 3 is Power transmission between 1 and 2 is performed. Since the power transmission is performed by the shearing of the oil film between the input and output cone disks 1 and 2 and the power roller 3, the power roller 3
Requires a pinching force between the input and output cone disks 1 and 2 with a large force corresponding to the transmission torque to be transmitted basically, and is necessary and appropriate for the power roller 3 which comes into frictional contact with the input and output cone disks 1 and 2. Supply of lubricating oil is required, and the supply of such lubricating oil is performed by the lubrication system 205 by controlling line pressure as described later.

The output cone disk 2 is wedge-mounted on an output shaft 25, and an output gear 29 is fitted on the output shaft 25 so as to rotate integrally. The output shaft 25 is further rotatably supported in an end cover 31 of the transmission case 21 via a radial and thrust bearing 30, and a radial and thrust bearing 3 is separately provided in the end cover 31.
2, the input shaft 20 is rotatably supported. here,
The radial and thrust bearings 30 and 32 butt against each other via a spacer 33 so that they cannot approach each other, and the corresponding output gear 29 and the input shaft 20 have an axial line so that they cannot be displaced relative to each other. Make contact in the direction.
Thus, the thrust acting between the input and output cone disks 1 and 2 by the loading cam 28 becomes an internal force that sandwiches the spacer 33 and does not act on the transmission case 21.

Each power roller 3 is, as shown in FIG.
The trunnions 41 are rotatably supported by trunnions 41. The trunnions are rotatable and swingable at both ends at both ends of an upper link 43 by a spherical joint 42, and are rotatable at both ends of a lower link 45 by a spherical joint 44 at a lower end. Swivel to connect. Then, the upper link 43 and the lower link 45
The center is supported by the spherical joints 46 and 47 on the transmission case 21 so as to be vertically swingable, so that the two trunnions 41 can be vertically moved synchronously in opposite directions.

A shift control device for shifting gears by moving the two trunnions 41 up and down in synchronization with each other in the opposite direction will now be described with reference to FIG. Each trunnion 41 is provided with a piston 6 for individually moving the trunnions 41 in the vertical direction. Upper and lower chambers 51, 52 and lower chambers 53, 54 are defined on both sides of the pistons 6, respectively. In order to control the strokes of the pistons 6 in opposite directions, the shift control valve 5 is installed. Here, the shift control valve 5 includes a spool-type inner valve element 5a and a sleeve-type outer valve element 5b which are slidably fitted to each other, and the outer valve element 5b is connected to the valve outer casing 5.
c so as to be slidably fitted.

The transmission control valve 5 has the input port 5d connected to the pressure source 55, one communication port 5e connected to the piston chambers 51 and 54, and the other communication port 5f connected to the piston chambers 52 and 53, respectively. I do. And the inner valve element 5a
And a cam surface of the precess cam 7 fixed to the lower end of one of the trunnions 41 via a bell-crank type shift lever 8, and the outer valve body 5b is connected to a step motor 4 as a shift actuator by a rack and pinion type. Drive engagement.

The operation command of the shift control valve 5 is given by the actuator (step motor) 4 responsive to the actuator drive position command Asstep (step position command) to the outer valve body 5b as a stroke via a rack and pinion. By this operation command, the outer valve body 5b of the transmission control valve 5
When the shift control valve 5 is opened by displacing the shift control valve 5 from the neutral position to the position shown in FIG. 3 with respect to the inner valve body 5a, the fluid pressure (line pressure P _L ) from the pressure source 55 is supplied to the chambers 52 and 53. On the other hand, when the other chambers 51 and 54 are drained, and the outer valve body 5b of the transmission control valve 5 is displaced in the opposite direction from the neutral position relative to the inner valve body 5a to open the transmission control valve 5. The fluid pressure from the pressure source 55 is supplied to the chambers 51 and 54, while the other chambers 52 and 53 are drained, and the two trunnions 41 are mutually moved in the corresponding vertical direction through the piston 6 by the fluid pressure. It shall be displaced in the opposite direction. As a result, both power rollers 3 have their rotation axis O ₁
Is offset (offset amount y) from the illustrated position intersecting the rotation axis O ₂ of the power roller 3. Tilt (tilt angle φ) around the swing axis O ₃ that is orthogonal to ₁ enables a continuously variable transmission.

During this shift, the precess cam 7 connected to the lower end of the one trunnion 41 shifts the above-described vertical movement (offset amount y) and tilt angle φ of the trunnion 41 and the power roller 3 via the speed change link 8. Feedback is mechanically fed back to the inner valve body 5a of the control valve 5 as indicated by x. When the speed ratio command value corresponding to the actuator drive position command Astep to the step motor 4 is achieved by the above-described stepless speed change, the mechanical feedback via the precess cam 7 is applied to the inner valve body of the speed change control valve 5. 5a
The was, is returned to a relatively initial neutral position with respect to the outer valve member 5b, at the same time, both the power roller 3, the rotation axis O ₁ intersects the rotation axis O ₂ of the input and output cone discs 1 and 2 shown By returning to the position, the state of achievement of the speed ratio command value can be maintained.

The controller 61 determines the actuator drive position command Asstep to the step motor 4. Since the aim of the control is to make the power roller tilt angle φ a value corresponding to the gear ratio command value, the precess cam 7 basically only needs to feed back the power roller tilt angle φ. Here, the reason why the power roller offset amount y is also fed back is to provide a damping effect of preventing the shift control from becoming vibratory, thereby avoiding the hunting phenomenon of the shift control.

The pressure source 55 is a hydraulic source including a line pressure control system including an oil pump, a pressure regulator valve (line pressure regulating valve), a line pressure solenoid 215, and the like. A configuration provided in a circuit can be employed. Here, the hydraulic source configured in this manner is controlled by considering the lubricating oil supplied to the transmission unit including the power roller and the input / output cone disk of the toroidal type continuously variable transmission (CVT) illustrated in FIGS. And preferably, in addition to this,
Line pressure control is also performed for the CVT hydraulic pressure and the clutch hydraulic pressure.

That is, in the case of the control example for lubricating oil pressure, CVT oil pressure, and clutch oil pressure, a pair of the input and output cone disks 1 and 2 A shift control pressure (CVT oil pressure) used for control of a continuously variable shift performed by hydraulically operating the power roller 3 via the piston 6, and a hydraulic friction element in the forward / reverse switching mechanism for the forward / reverse switching system 202. Considering the pressure acting as the operating pressure (fastening pressure) (forward or reverse clutch oil pressure), and the pressure of the lubricating oil (lubricating oil pressure) used for lubrication of the power roller 3 and the like by the lubrication system 205. By the duty drive control of the line pressure solenoid 215 of the line pressure control system,
Pressure regulation shall be performed.

The step motor 4 and the line pressure solenoid 215 are controlled by a controller 61. The controller 61 has a signal from a throttle opening sensor 62 for detecting an engine throttle opening TVO and a vehicle speed VSP as shown in FIG. From the vehicle speed sensor 63 for detecting
An engine rotation sensor 68 for detecting an engine speed N _e
Signals from, and other signals from sensors, for example, a signal from an input rotation sensor for detecting the rotational speed N _i input cone disc 1 (or the engine speed N _e), the rotational speed of the output cone disc 2 signal from the output rotation sensor for detecting the N _o, the signal from an oil temperature sensor for detecting a transmission working oil temperature TMP, detects the line pressure P _L from the hydraulic pressure source 55 (the line pressure P _L by the controller 61 A signal from a line pressure sensor (which is detected from an internal signal of the controller 61 because of control) is input.

The controller 61 includes a microcomputer. Here, the controller 61 has functions such as shaping input signal waveforms from various sensors and the like, and A / D converting an analog signal value into a digital signal value. An input detection circuit, an arithmetic processing circuit (CPU), and a storage circuit for storing various control programs executed by the arithmetic processing circuit, such as a shift control program and a line pressure control program, as well as operation results and other information. RAM, ROM)
And an output circuit for sending a control signal for driving (a shift command value, a line pressure control command value, etc.) to the step motor 4, the line pressure solenoid 215, and the like.

The shift control is basically performed by a shift control program (not shown) based on the above-mentioned various input information so as to calculate a target shift ratio and set the shift ratio to the target value. Step motor 4
The shift control can be performed by determining the actuator drive position command Asstep (shift command value).

Then, the line pressure P_LIn the control of
FIG. 4 and FIG. 5 show an example of the controller 61.
Line to be set according to the program shown in the chart
Pressure P _LValue and write the corresponding drive duty
Command to the line pressure solenoid 215 as the pressure control command value
Thus, the line pressure control is performed. in this case
In the control program example shown below,
Based on the speed VSP information, the throttle opening TVO information
Line pressure P at high vehicle speeds_LRaise
Control to secure the amount of lubricating oil at high vehicle speed
Pressure UP (increase) control) and the engine speed.
N_eBased on the information, the line pressure P_LAnd CVT at low rotation
Required hydraulic pressure (P_CVT) And clutch required hydraulic pressure (P_CLU) Key
Required for lubrication (P_LUB) Upon request
Control to achieve both sound vibration and hydraulic performance (engine
Line pressure switching control by the number of turns).

Hereinafter, a more specific description will be given, including FIGS. Here, FIG. 6 shows the input torque, the line pressure,
FIG. 7 is a diagram showing the relationship between pump noise (sound vibration) and FIG.
FIG. 4 is a diagram showing the relationship between the required oil pressures of the required oil pressure for lubrication, the required oil pressure for CVT, and the required oil pressure for the clutch. Further, FIG. 8 is the input rotational speed represents the basic principle of the engine speed corresponding variable line pressure control - line pressure P _L characteristic diagram, Fig. 9 is the engine speed showing an example of the content of a suitable set hydraulic N _e - line it is a characteristic diagram of the pressure P _L. FIG. 10 shows a preferred example of the control range of the line pressure increase control at high vehicle speed.
Area Figure by the throttle opening TVO, FIG. 11 is a characteristic diagram of the vehicle speed VSP- line pressure P _L showing an example of the content of a suitable set hydraulic pressure. FIG. 12 is an explanatory diagram of a comparative example shown in comparison with FIG.

[0043] In FIG. 4, in this example program, first in step S101, executes the computation of the setting processing for the line pressure P _L switching control by the engine speed N _e.

The purpose of this line pressure P _L switching control is to achieve both sound vibration (oil pump noise of the transmission unit) and hydraulic performance (here, required oil pressure required for lubrication, required oil pressure for CVT, required oil pressure for clutch). . In particular, as shown in the consideration diagrams of FIGS.
When each required hydraulic pressure of the clutch required hydraulic pressure is determined by the transmission input torque as illustrated in FIG. 7, the relationship shown in FIG. 6 between the three elements of the transmission input torque, the line pressure, and the pump noise. The aim is to achieve both sound vibration and hydraulic performance.

According to these figures, the relationship (-) in FIG.
As shown in (1), when the method simply depends on the method of setting the line pressure according to the input torque, the line pressure can be set higher as the input torque is larger. Because of the relationship shown in FIG. 6, as the line pressure is set higher, the pump noise (sound vibration) also increases (,). On the other hand, if the line pressure is set higher, the line pressure is reduced in terms of sound vibration. When set,
Even though the pump noise can be reduced, the line pressure is controlled to be low, so that the transmission torque must be adjusted according to the input torque of the transmission. The hydraulic pressure (FIG. 7) cannot be satisfied, and in particular, the higher the set hydraulic pressure, the more difficult it is to cope with that point.

In this example of the program, these points are compatible with each other as follows. FIG. 5 shows a subroutine of the line pressure variable control corresponding to the engine speed for that purpose. In steps S201 to S203 of FIG. 5, three kinds of required oil pressures, that is, the required oil pressure P _LUB and the required CVT oil pressure P
Calculate _CVT and clutch required oil pressure _PCLU . Here, each target required hydraulic pressure P _LUB , which is a target of the line pressure setting,
P _CVT and P _CLU are hydraulic pressures obtained by obtaining respective required hydraulic pressure values according to the transmission input torque.

That is, the required lubricating oil pressure P _LUB is given by

P _LUB = Input torque Ti × Coefficient K1 + Coefficient K2 (1) Here, equation (1) basically means that the required hydraulic pressure value can be set by the transmission input torque, and therefore can be set to correspond to the transmission input torque (this point is expressed by the following equations (2), (The same applies to (3)), and the coefficient K2 is an offset-equivalent value. As for the lubrication oil pressure P _LUB , the value obtained by multiplying the input torque Ti by the coefficient K1 as described above is added to the coefficient K2 as an offset value.
Is added to calculate (see FIG. 7).

As for the input torque value, for example,
Obtains an output torque of the engine 100 from the throttle opening TVO and the engine speed N _e, applied to values calculated transmission input torque T _i multiplied by the torque ratio t of the torque converter 201 to the engine output torque (estimated value) The same applies to the following equations (2) and (3).

That is, the required CVT hydraulic pressure P _CVT is

P _CVT = Input torque Ti × Coefficient K3 determined by speed ratio (2) (2) Further, regarding the clutch required hydraulic pressure P _CLU , similarly to the case of the hydraulically operated friction element used in the transmission,

P _CLU = input torque Ti × coefficient K4 + coefficient K5 (3), the value obtained by multiplying the input torque Ti by the coefficient K4 is given by:
The calculation is performed by adding a coefficient K5 as an offset value (see FIG. 7). Then, the calculated values P _LUB , P _CVT , and P _{CLU thus} obtained are stored in the memory of the storage circuit of the controller 61 as the required hydraulic pressure data at the time.

Next, in step S204 and subsequent steps, a predetermined value for discrimination regarding the engine speed is used, and basically, it is determined whether the engine speed is in a low speed range or a high speed range, and the high speed is determined. In the case where the oil pressure is in the range, the lubrication required oil pressure value P _LUB calculated in the step S201 is taken into consideration, and the line pressure is set according to the P _LUB value. Area, the P
Regardless of the _LUB value, it is sufficient to meet the required required oil pressure at the time of low engine rotation (here, the calculated CVT required oil pressure P _CVT value in step S202 and the calculated clutch required oil pressure P _CLU value in step S203). The process of determining the set line pressure (P _L (e)) in this subroutine is executed by setting the line pressure.

In this case, when setting the line pressure,
Lubrication will not be considered in the low rotation range,
At low engine rotation (for example, about 2000 rpm or less)
Is low in heat generation (heat generation in the power roller 3 in the case of this example). Therefore, even if the required lubricating oil pressure is low, the problem is less than in the case of high rotation, and the line pressure and pump noise (FIG. From the viewpoint of sound vibration, it is based on the idea that it works more advantageously due to the effect of sound vibration reduction (in the low rotation speed range, the hydraulic pressure (line pressure P _L) is particularly increased to the level of the above-described lubrication required oil pressure. ) without to be increased, a region that would sufficient if it is rotated as usual (pump drive), therefore, in this region, to determine the line pressure P _L from the required hydraulic pressure of the CVT and a clutch That is what you do). Therefore, according to this control, while achieving the compatibility with the sound vibration according to the present control, as shown in FIG. 8, the clutch required hydraulic pressure P _CLU (Equation (3)) according to the input torque at the time of low engine rotation as shown in FIG. ) And CVT required oil pressure P _CVT
In (Equation (2)), the originally required line pressure can be appropriately changed (FIG. 8). Basically, even in this control, the required oil pressure is determined by the input torque. However, as described above, the actual required oil pressure is low at low rotation because the set value is linear. Therefore, the control is divided into the low-speed rotation and the high-speed rotation, so that the control is based on the engine rotation.

Here, in this program example, the engine
A predetermined rotation value N for the first determination is used to determine the shift area._e(a)
And a predetermined second predetermined rotation speed N for the second determination.
_e(b) (N _e(a) <N_e(b)) and (Fig.
9) First, in step S204, the engine speed N_e
Is a predetermined value N_e(a) judge whether it is lower than
(N_e≤N_e(a)), execute the processing in block A in the figure
I do. That is, further, in step S211, the calculated CV
T required hydraulic pressure P_CVTCalculated clutch required oil pressure P_CLUWho
Is large (high) or not (P_CVT≤P_CLUJudge)
As a result of comparing the two, the calculated CVT required oil pressure P_CVTIs big
If (the answer of step S211 is No), the P_CVTThe value
Set line pressure value P_L(e) (Step S21)
2), calculated clutch required oil pressure P_CLUIf the
The answer of step S211 is Yes), that P_CLUSet value
Pressure value P_L(e) is set (step S213).

[0053] the engine speed N _e is the first predetermined value N _e
When it is higher than (a) (the answer to step S204 is No)
Further determines whether the engine speed N _e is less than a second predetermined value N _e (b) in step S205, if lower (the answer to step S205 is Yes), therefore the engine speed N _e is If the engine speed is the engine speed range between the predetermined values _Ne (a) and _Ne (b), ( _Ne (a) <N
_{e <N e (b))} , interpolation calculation processing (the process proceeds to step S231), the engine speed N _e is the second predetermined value N
When it is higher than _e (b) (No in step S205)
Executes the processing in block B in the figure.

That is, in step S221, the calculated CV
It is determined whether the calculated clutch required oil pressure P _CLU is larger (higher) than the T required oil pressure P _CVT (P _CVT ≤ P _CLU ),
As a result of comparing the two, if the calculated CVT required oil pressure P _CVT is large (No in step S221), the _PCTVT value is set as the set line pressure value P _L (e) (step S2).
22). On the other hand, if the calculated clutch required oil pressure P _CLU is large (the answer to step S221 is Yes), it is further determined in step S223 whether the calculated lubrication required oil pressure P _LUB is larger (higher) than the calculated clutch required oil pressure P _CLU (P. _{CLU ≤P
LUB} ), and as a result of comparing the two, if the calculated clutch required oil pressure P _CLU is large (the answer to step S223 is N)
o), the _PCLU value is set as the set line pressure value P _L (e) (step S224), and if the calculated required lubricating oil pressure P _LUB is large (the answer to step S223 is Yes), the P _PLU is set.
_{The LUB} value is set as the set line pressure value P _L (e) (step S225).

Here, the engine speed _Ne is set to a predetermined value _Ne.
(b) In the higher rotation range, the calculated CVT required oil pressure P _CVT and the calculated clutch required oil pressure P _CLU are also set in some cases because they may be higher than the calculated lubrication required oil pressure P _{LUB in} some cases. Therefore, the line pressure can be set by selecting the highest one of the three.

The process of setting the line pressure value P _L (e) in step S231 can be performed, for example, by the following equation (4) (linear interpolation (interpolation interpolation) calculation). .

[0057]

P _L (e) = (result of A) + (result of B−result of A) × (N _e −N _e (a)) / (N _e (b) −N _e (a)) ... (4) Here, "Result of A"; P in step S212 or S213
_L (e) value "Result of B"; step S222, S224 or S2
P _L (e) value at any of 25

The above-mentioned setting processing using the two determination values _Ne (a) and _Ne (b) relating to the engine speed is performed as shown in FIG. Between the point a and the point b, a line connecting the points a and b is changed (the engine speed N _e −
The line pressure is gradually changed from P _L ′ to P _L ″ in view of the line pressure P _L characteristic) to make the line pressure control characteristic a linear characteristic.

Basically, as described above, this control can perform line pressure switching control for achieving both sound vibration and hydraulic performance by dividing the engine into a low engine speed region and a high engine speed region. However, when the target of the required hydraulic pressure applied to the line pressure setting is different between the low rotation range and the high rotation range (for example,
As shown in the example of FIG. 9, the calculated lubrication required oil pressure P _LUB value is selected in the high rotation speed region, and the value P _L (e) is set with this value. Considering that there is a higher value between the CVT required hydraulic pressure P _CVT value and the calculated clutch required hydraulic pressure P _CLU value and this sets the value P _L (e)), When the engine rotation range is divided into a low range and a high range (low range, middle and high range) by setting and using only one type of separate value, that is, for example, the predetermined value N _e (a )) (Or, conversely, only the predetermined value _Ne (a)) is set as a discrimination value, and when the area is divided, the discrimination value for switching the line pressure control corresponding to the engine speed is set. characteristics of the location of the corresponding engine speed N _e, the line pressure setting properties at high rpm side from the characteristic in the low speed range side As it jumps and,
The characteristic changes discontinuously and abruptly in a step-like manner.

However, even in this case, both the sound vibration and the hydraulic performance, that is, the suppression of the sound vibration (pump noise) and the required oil pressure, are basically achieved.
However, before and after the engine speed N _e, the sound vibration characteristics would result in changes in stage manner. Therefore, it is more desirable that such a phenomenon can be avoided. Therefore, in this example of the program, a method as described above, which can be a line pressure setting characteristic including a setting characteristic between a and b points as shown in FIG. 9, is also introduced.

Thus, the set line pressure P _L (e) determined in this subroutine (in this program example, step S2
31 (including _P.sub.L (e) set at 31) is applied as the final line pressure _P.sub.L value to be set as _P.sub.L = _P.sub.L (e) (step S111 (FIG. 4) described later). When the drive duty corresponding to the above is instructed to the line pressure solenoid 215 as the line pressure control command value, and the line pressure control is executed, both the sound vibration and the hydraulic performance are achieved.

When the engine 100 is in a high rotation range (here, N
_e ≧ N _e (b)), considering the lubricating oil to be used for lubrication of the toroidal type continuously variable transmission shown in FIGS. By comparing the calculated required oil pressure obtained by equation (1) as P _LUB and the calculated required oil pressure to be compared with the calculated required oil pressure, the line pressure can be reliably set according to the higher required oil pressure. Hydraulic performance can be ensured (Block B), and
In the low rotation range (here, _Ne ≦ _Ne (a)), the demand for the calculated required oil pressure is not increased unnecessarily without depending on the calculated lubrication required oil pressure P _LUB. It is possible to reliably set the necessary line pressure in accordance with this (block A).

Therefore, if it is determined that the engine speed is in the low rotation range, the CVT required oil pressure P _CVT obtained by the equation (2) is used.
And the clutch required oil pressure P _CLU obtained by the equation (3), and the line pressure can be appropriately determined so as to set the line pressure according to the higher required oil pressure. In the case of the range, the required lubricating oil pressure P _LUB is further applied as a comparison target, and the required lubricating oil pressure P _LUB , the required CVT required oil pressure P _CVT and the required clutch oil pressure P _CLU are compared, and the highest required oil pressure among them is obtained. The line pressure can be appropriately determined so as to set the line pressure in accordance with the above. In the toroidal transmission unit, the power roller 3 is pressed between the input and output cone disks 1 and 2, and the oil film between the power roller 3 and the input and output cone disks 1 and 2 is sheared to form the input and output cone disks 1 and 2. When power is transmitted between the input and output cone disks 1 and 2, the power roller 3 needs to be pinched between the input and output cone disks 1 and 2 with a large force corresponding to the transmission torque, and is in frictional contact with the input and output cone disks 1 and 2. 3 requires the supply of a necessary and appropriate lubricating oil, the required hydraulic performance including the supply of the lubricating oil is also controlled by this line pressure control to achieve a high degree of compatibility with the sound vibration characteristics, that is, the hydraulic pump noise. Is also realized.

In the case where the present invention is applied to a stepped automatic transmission,
It should be noted that in a stepped automatic transmission,
Required CVT (Continuously Variable Transmission) required oil
Pressure P _CVTDoes not exist, so the oil pressure required for lubrication is high
Lubrication is required only for
Hydraulic pressure and shifting friction elements (hydraulic clutch, hydraulic brake
Set the line pressure to the higher of the required oil pressure calculated in g)
In the low rotation range, the lubrication oil pressure
The required hydraulic pressure for calculating the friction element for shifting
If there is more than one required hydraulic pressure for calculating the shifting friction element,
Line pressure setting
(To find the oil pressure required for lubrication and the friction element for shifting
In this case, it may be based on the equations (1) and (3)).

[0065] Further, as the predetermined value for determination regarding the engine speed N _e of engine speed to determine whether the high-speed range or a low speed range, the first predetermined value N _e (a), from which big in the second of this program example of using a predetermined value N _e (b), the predetermined value N _e (a) the following low engine speed region (first engine speed region) and a predetermined value N _e (b) above The line pressure can be set according to the required hydraulic pressure in each of the high engine speed range (second engine speed range).
In the engine speed range (third engine speed range) between these predetermined values _Ne (a) and _Ne (b), the line pressure is controlled by setting the line pressure so as not to rapidly change the line pressure control characteristic. It is possible to avoid stepwise changes in sound and vibration characteristics, and it is possible to set finer line pressure control characteristics based on engine speed, and to achieve a higher level of compatibility between sound and vibration and hydraulic performance. be able to.

In this case, as shown in equation (4), the respective set line pressure values in the case where the engine speed is equal to or less than the predetermined value N _e (a) and the case where the engine speed is equal to or more than the predetermined value N _e (b) are When the line pressure in the engine rotation range between the predetermined values N _e (a) and N _e (b) is set by applying the interpolation value obtained by the linear interpolation calculation, the sound vibration characteristics change stepwise. Instead, the characteristic can be made to change linearly as it changes on the straight line connecting the points a and b in FIG. 9, which can be more effective.

It should be noted that the above-described technique of preventing the stepwise change in the sound vibration characteristics can be applied even when the line pressure control is applied to the stepped automatic transmission as described above. In this case, a first predetermined value and a second predetermined value larger than the first predetermined value are similarly used as the predetermined values for the determination according to the above, and the first predetermined value is used. The line pressure is set in accordance with the required lubricating oil pressure in a first engine rotation range equal to or less than a predetermined value, and in accordance with the calculation required oil pressure of the shifting friction element in a second engine rotation range equal to or more than the second predetermined value. When the line pressure is set, the line pressure setting in the third engine rotation range between the first predetermined value and the second predetermined value is performed by the same interpolation calculation as described above. The line pressure can be determined so that the line pressure is set so as not to change suddenly.

Returning to FIG. 4, in the figure, step S101 is
The vehicle speed VSP is the predetermined vehicle speed VS as shown in FIGS.
This is a step of determining whether or not P1 or more. In this example of the program, as a determination step, a determination step of step S102 and step S103 is additionally provided. In step S102, the vehicle speed VSP is
When the vehicle speed is determined to be equal to or higher than the predetermined vehicle speed VSP1 as shown in FIG. 0 (the answer to step S101 is Yes), the throttle opening TVO of the engine 100 is set to a value close to the fully closed state as illustrated in FIG. This is a step of checking whether the opening degree is smaller than a predetermined low opening degree TVOC.

In step S103, the condition that the answer of step S101 is Yes and the answer of step S102 is No is satisfied (that is, the vehicle speed is equal to or higher than the predetermined vehicle speed VSP1 and the engine throttle opening TVO is close to the fully closed state). those selected if not), here, the engine speed N _e by the line pressure variable control process (setting obtained in step S100) line pressure value P _L (e), a high speed at step S110 This is a step for comparison with a predetermined line pressure value P _LH to be applied for the time line pressure increase control. Here, the predetermined value P _LH is, as illustrated in FIG. 11, a high line pressure value which is a target value of the line pressure increase control in order to uniformly increase (bently increase) the line pressure P _L. (Constant).

As a result of the comparison in step S103, when the line pressure value P _LH applied in the line pressure increase control is higher than the set line pressure value P _L (e) (P _LH ≧ P _L (e)) , Step S111 is selected. In this case, P
Let _L = a certain high value P _LH (constant). So this is
This is applied as the line pressure P _L to be set.

Therefore, in this example of the program, the line pressure increase control by the setting process in step S110 is basically selected with respect to the vehicle speed VSP under conditions equal to or higher than the predetermined vehicle speed VSP1, and the vehicle speed lower than the predetermined vehicle speed VSP1 is selected. In step S111, a result (P _L = a line pressure control value other than the main line pressure increase control (second line pressure control value) other than the main line pressure increase control) described later is selected and the main line pressure increase control is not executed (line pressure This control is executed in a high vehicle speed region. Therefore, the above P _LH value is applied as the line pressure P _L value to be set by this program, and the corresponding drive duty is instructed to the line pressure solenoid 215 as a line pressure control command value to execute the line pressure control. when go is obtained is increased to ensure a constant pressure P _LH line pressure P _L at a predetermined vehicle speed VSP1 or more high speed, it is controlled to ensure the amount of lubricating oil at a high speed can be realized. Therefore, even when operating on a high-speed road where high rotation and high torque continue for a long time, heat generation of the heat generating portion of the transmission mechanism, and therefore, increase in the oil temperature of the power roller 3 can be suppressed well.

[0072] The aim of such high speed line pressure P _L increase control, even light of the surface of the fuel consumption or the like, in which the skillfully harmonized so control the lubricating oil amount of priority. This is based on the following points, and will be further described. First, the control at the time of a low vehicle speed lower than the predetermined vehicle speed VSP1 may basically follow the characteristic tendency illustrated in the consideration FIG. 7, and accordingly, the line pressure value may be changed according to the transmission input torque. (See the above equations (1) to (3)), the line pressure can be basically determined by the transmission input torque, and the characteristic of the line pressure setting corresponding to the input torque is as follows. You can make use of this.

Here, specifically, the highest oil pressure among the required oil pressures shown in FIG. 7 can be used as the line pressure. In the control at low vehicle speed, basically, the line pressure increase control is performed. , The required hydraulic pressure P _LUB (corresponding to the required amount of lubricating oil), the required CVT hydraulic pressure P _CVT , and the required clutch hydraulic pressure P _CLU
Of these, the highest one can be selected. In this way, among them calculating hydraulic determines a line pressure to set the line pressure P _L by selecting the highest pressure required by obtained without the line pressure P _L control at low vehicle speed, At that time, as described above, the required hydraulic pressure (the line pressure set value P _L (e)
), The line pressure originally required can be changed appropriately.

The line pressure control at the time of low vehicle speed can be controlled in accordance with such a required oil pressure. However, if the line pressure control is performed at any speed regardless of the vehicle speed (low vehicle speed, high vehicle speed), the line pressure control can be performed exclusively. with, for example, FIG. 7 when the characteristic lubrication requiring hydraulic setting the line pressure as shown, in which case, as the line pressure P _L characteristic with respect to the vehicle speed VSP when viewed as a torque as a parameter, shows in comparison with FIG. 11 It becomes something like 12.

That is, the characteristics shown in FIG. 12 are plotted on the vertical axis for the line pressure P _L and the horizontal axis for the vehicle speed VSP. In the case of the torque on the maximum side (torque MAX), like the curve characteristic at the top of the figure. , And the minimum torque (torque MIN)
In the case of, it can be expressed as the characteristic at the bottom in the figure. Here, in the case of the comparative example shown by the broken line in FIG. 12, for example, in a driving scene where the accelerator pedal is depressed,
The hydraulic pressure (line pressure) required for lubrication should increase in proportion to the right as shown in the lower solid line as the vehicle speed VSP increases. May become insufficient in oil amount (in terms of line pressure, insufficient hydraulic pressure), and the amount of oil required for lubrication may not be sufficient with the above oil pressure setting at high vehicle speeds. The line pressure control according to this example of the program is based on this, and adds this line pressure increase control.

The amount of the lubricating oil is such that the temperature of the heat generating portion (in the case of a toroidal type continuously variable transmission, the oil temperature of the power roller) increases when the high torque and the high torque generation state continue for a long time, High rotation, which is necessary to lower the temperature of
It is the highway that the high torque lasts for a long time. Thus, with the addition of a control to make lubricating oil amount properly raise the line pressure P _L at high speed.

[0077] Here, as the mode of increase in line pressure P _L, preferably, it is desirable to as shown in FIG. 11. In this example, the line pressure P determined by the input torque
_{The control is} to increase the set value of _L , and to take measures against insufficient flow in the partial area by increasing the line pressure PL.
In this case, the line pressure set value is changed to the predetermined vehicle speed VSP.
In one or more vehicle speed ranges, a predetermined high constant line pressure value,
Here, this is performed by switching to a value equivalent to the torque MAX (this can also be regarded as a switching correction process for the original input torque corresponding line pressure set value).

In this case, the rebound by always setting the torque to MAX may include the point of fuel efficiency. However, the lubricating oil amount is prioritized and the lubricating oil is always equivalent to the torque MAX. (For example, when the foot is released from the accelerator pedal), the amount of oil is constantly increased, so that the heat generated by the power roller 3 in the toroidal transmission unit, which is a heat generating unit, is positively increased. Is lowered).

In FIG. 11, the vehicle speed V in the process of increasing the vehicle speed is shown.
SP1 upon reaching, for example, in terms of the relationship between the lower solid line characteristic (torque MIN) in Fig. 12, even if the raising of the extra line pressure P _L than, that larger amount flow lubricant , for the unit (toroidal transmission unit), it is assumed that acts in a direction to increase the durability, while also, even if the line pressure P _L rises rapidly, because traveling, in the continuously variable transmission N → There is no problem of shock such as D-shock, and generally, the continuously variable transmission system employing the line pressure increase control works advantageously. Also fuel efficiency,
Furthermore, in terms of sound and vibration, taking this into consideration, the present control is basically prohibited in an operation area other than the target area of the present control (the answer to step S101 is No.
→ S111, the answer of step S102 is Yes → S11
1) On the other hand, in the region of the present control, the request for the fuel consumption is relatively less severe and the influence on the fuel consumption and the like can be said to be less than that in the region such as the low rotation where the fuel consumption and the sound vibration are relatively important. Therefore, when these are combined, including such aspects of fuel efficiency,
This works advantageously as a whole of the continuously variable transmission system mounted on the vehicle.

In step S102 in FIG. 4, when the throttle opening TVO is close to the fully closed position, step S110 is not selected, and step S111 is selected. As a result, even if the vehicle is traveling at the vehicle speed VSP equal to or higher than the predetermined vehicle speed VSP1, the line pressure increase control is not executed at this time (line pressure increase control prohibition control). In this case, the execution area of the main line pressure P _L increase control can be the shaded area (“P _L up” area) in FIG. 10, and therefore, when the throttle is fully closed (0/8). Is
For example, the line pressure increase control may not be performed due to interference with other controls. As a result, the throttle opening T
Even when another second line pressure control is to be executed near the fully closed state of the VO, control interference, for example, in which the line pressure set values conflict with each other can be reliably prevented.

In this program example, step S11
In the case where the line pressure is set by the processing of P _L = other line pressure control value at 1, the other line pressure control (the line pressure P _L based on the engine speed) other than the main line pressure P _L increase control is performed. The target area to be subjected to the second line pressure P _L control executed as the switching control (including step S100) is as follows.

[1] A region where the vehicle speed VSP is lower than the predetermined vehicle speed VSP1, [2] A vehicle speed VSP is higher than the predetermined vehicle speed VSP1 and
In addition, the throttle opening TVO is an area where the throttle opening TVO is an opening degree (including fully closed) in the vicinity of the fully closed state.
As a result of the determination in step (3), under the condition that P _L (e)> P _LH is satisfied, [3] the region where the vehicle speed VSP is equal to or higher than the predetermined vehicle speed VSP1 and the throttle opening TVO is other than near the fully closed state (that is, , "P _L up" region of FIG. 10) is also of interest. In this case, the line pressure control is performed in combination with the second line pressure control so that the line pressure P _L described above is used.
It can be more comprehensive and integrated, including ascent control. In this case, the following control is executed as the second line pressure control in this example of the program.

In the above [1], the line pressure control at the time of low vehicle speed is performed.
_LUB , CVT required hydraulic pressure P _CVT , clutch required hydraulic pressure P _CLU
Line pressure P _L
Control can be performed (see FIG. 10). In particular,
More preferably, it may be by the engine rotational speed corresponding line pressure P _L control according to the process of the subroutine of FIG. 5 described above (step S201~S231). In this case, it can be used with line pressure switch function by the engine speed N _e, the control region of the line pressure, in addition to the vehicle speed VSP, and also divided cut with a low speed range and high speed range of the engine speed, finer line Pressure control is possible and P
_{As a process of L} = other line pressure control values, the P _L (e) value calculated by the subroutine in FIG. 5 is applied as P _L = P _L (e) to execute the line pressure control. the number corresponding line pressure P _L variable control by also utilized aforementioned advantages, both the sound vibration and hydraulic performance is achieved.

As the second line pressure P _L control in [2], when the throttle opening TVO is fully closed, a line pressure reduction control for reducing the line pressure P _L is executed. The continuously variable transmission is continuously downshifted to the low (higher gear ratio) gear ratio with the input rotation due to full closure and the decrease in vehicle speed, even if the high (lower gear ratio) gear ratio is selected. In view of this, the second line pressure P _L control is intended to prevent the line pressure from being high and a sudden low downshift during coasting. Therefore, according to this, at the time of coasting, while the present line pressure increase control prohibits this, unlike the line pressure increase control, the second line pressure P _L that actively reduces the line pressure is used.
The overall control of the line pressure including the control can be realized, and the vehicle speed V
Even if the SP is equal to or higher than the predetermined vehicle speed VSP1, the above-mentioned sudden low-down shift can be reliably avoided, which is a suitable fail-safe measure. In addition, the interference with the fail-safe can be reliably prevented. In this case, the priority is higher than the priority of the lubricating oil amount, and the highest priority of the fail-safe control can be realized.

In the second line pressure P _L control in the above [3], the set line pressure P _L (e) value calculated by the above-described engine speed corresponding line pressure P _L control processing and the main line pressure P _L increase control Is executed based on the result of the comparison with the line pressure value P _LH to be applied in the above, and under the condition of P _L (e)> P _LH , by the setting process of P _L = P _L (e), the engine speed corresponding line pressure P _L control, the second line pressure P _L
This will be executed as control. That is, as a result of the comparison, under the condition of P _LH ≧ P _L (e), the above-mentioned line pressure P _L increase control is executed, while under the condition of P _L (e)> P _LH , the vehicle speed VSP there a predetermined vehicle speed VSP1 or more, and the throttle opening TVO even when the region other than the near total閉付, can be made to execute the engine speed corresponding line pressure P _L control. With this configuration, the line pressure increase control and the engine speed corresponding line pressure P _L control as the second line pressure P _L control,
Both of these can be achieved, and optimization as comprehensive line pressure control becomes possible.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the case where the line pressure control device of the present invention is applied to a toroidal type continuously variable transmission has been described, but the present invention can be similarly applied to a V-belt type continuously variable transmission. It is needless to say that the same operation and effect can be obtained even if the present invention is applied not only to the continuously variable transmission but also to a stepped automatic transmission.

In the case of a stepped automatic transmission, the transmission 20
0 (FIG. 1) has a friction element for speed change such as a hydraulic clutch or a hydraulic brake in the speed change mechanism and directly controls the operating oil pressure value of the friction element individually. Also in a transmission, for example, a unit with a design concept in which lubrication is an important factor and a set hydraulic pressure is high may require similar control, and is effective when applied to such a case.

Further, in the above program example, the case where the line pressure increase control at high vehicle speed and the line pressure switching control based on the engine speed are used in combination has been described. However, it goes without saying that the present invention is not limited to such an embodiment. No. Accordingly, the present invention can be implemented in a mode in which only the line pressure switching control based on the engine speed is executed, and the above-described operation and effect of the present control can be naturally obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a system configuration of an automatic transmission including a line pressure control device according to an embodiment of the present invention.

FIG. 2 is a longitudinal side view of a toroidal type continuously variable transmission that can be applied.

FIG. 3 is a vertical sectional front view showing the toroidal-type continuously variable transmission together with a shift control system thereof.

FIG. 4 is a flowchart illustrating an example of a line pressure control program executed by a controller in the example.

FIG. 5 is a flowchart showing an example of a subroutine for line pressure switching control according to the engine speed in the control program.

FIG. 6 is a diagram provided for explanation of line pressure control by the control program, and is a consideration diagram showing a relationship among input torque, line pressure, and pump noise (sound vibration).

FIG. 7 is a view showing the relationship between the required oil pressures of the required oil pressure for lubrication, the required oil pressure for CVT, and the required oil pressure for a clutch.

FIG. 8 is a characteristic diagram of the input rotation speed-line pressure P _L showing the basic principle of the line pressure variable control corresponding to the engine rotation speed.

[9] Also, according to the engine rotational speed corresponding variable line pressure control, an example content of a suitable set hydraulic engine speed N _e - it is a characteristic diagram of the line pressure P _L.

FIG. 10 is a control area diagram based on vehicle speed VSP-throttle opening TVO, showing an example of a suitable control area for line pressure increase control at high vehicle speed.

[11] Also, an example of the content of a suitable set hydraulic by high speed line pressure up control, is a characteristic diagram of the vehicle speed VSP- line pressure P _L.

FIG. 12 is an explanatory diagram of a comparative example shown in comparison with FIG. 11;

[Explanation of symbols]

 Reference Signs List 1 input cone disc 2 output cone disc 3 power roller 4 step motor (shift actuator) 5 shift control valve 6 piston 7 precess cam 8 shift link 20 input shaft 28 loading cam 41 trunnion 43 upper link 45 lower link 55 pressure source (hydraulic source) 61 Controller 62 Throttle opening sensor 63 Vehicle speed sensor 68 Engine rotation sensor 100 Engine 200 Transmission 201 Torque converter 202 Forward / reverse switching system 205 Lubrication system 210 Control unit 215 Line pressure solenoid 250 Output shaft

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F16H 63:06

Claims (5)

[Claims] 1. A control device for controlling a line pressure in an automatic transmission having a transmission mechanism and including a hydraulically operated friction element, for shifting and transmitting rotational power from an engine, comprising: Determining means for determining whether the engine speed is in a low rotation range lower than the predetermined value or in a high rotation range higher than the predetermined value, and a determination result by the determination means; Means for controlling the line pressure based on the lubricating oil required for supplying the lubricating oil in the case of the high rotation range, in consideration of the lubricating oil used for lubrication of the transmission mechanism. The required first required oil pressure is compared with at least the second required oil pressure required as the friction element necessary oil pressure required for the hydraulic operation of the friction element, and the line pressure is adjusted according to the higher required oil pressure. Setting And a line pressure determining means for determining a line pressure so that the line pressure can be set according to the request for the second required hydraulic pressure, regardless of the first required hydraulic pressure, in the case of the low rotation speed range. A line pressure control device for an automatic transmission, comprising: line pressure control means. 2. The continuously variable transmission according to claim 1, wherein the transmission mechanism is a continuously variable transmission mechanism, and the line pressure control means determines that the transmission is in the low rotation speed range by the continuously variable transmission mechanism. A third required hydraulic pressure required as a hydraulic pressure required to be supplied as a control pressure used for speed change control is compared with the second required hydraulic pressure, and a line is determined according to the higher required hydraulic pressure. Means for determining a line pressure so as to set a pressure, wherein the third required hydraulic pressure is further applied as a comparison target in the case of the high rotation speed range, and the first required hydraulic pressure and the second required hydraulic pressure Comparing the required hydraulic pressure with the third required hydraulic pressure, and determining the line pressure so as to set the line pressure according to the highest required hydraulic pressure among them. Line pressure control device. 3. The method according to claim 1, wherein the determining unit determines a first predetermined value and a second predetermined value that is larger than the first predetermined value.
The line pressure control means includes: a line pressure setting characteristic that is set in a first engine speed range where the engine speed is lower than or equal to the first predetermined value; For the line pressure setting characteristic set in the second engine rotation range higher than or equal to the predetermined value, the engine speed in the third engine rotation range between the first predetermined value and the second predetermined value. 3. The automatic apparatus according to claim 1, further comprising means for determining the line pressure so that the set line pressure does not rapidly change the line pressure control characteristic. Transmission line pressure control device. 4. A method for setting a line pressure in the third engine speed range so as not to sharply change a line pressure control characteristic, wherein a line pressure set value set in the first engine speed range and Applying an interpolation value obtained by a linear interpolation operation using each set value of the line pressure set value set in the second engine speed range, the first engine speed range and the second engine speed range The line pressure control device for an automatic transmission according to claim 3, wherein a line pressure between the lines is set. 5. The system according to claim 1, wherein all or a part of the required hydraulic pressure to be set for the line pressure is obtained by obtaining a required hydraulic pressure value according to a transmission input torque. A line pressure control device for an automatic transmission.