JP3465597B2 - Line pressure control device for automatic 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 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 V-belt type continuously variable transmission and a continuously variable transmission (CVT) represented by a toroidal type continuously variable transmission,
In an automatic transmission mounted on a vehicle, a hydraulic pressure 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 speed change 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 so as to correspond to the input torque of the transmission, and the line pressure is raised according to the input torque. A device has been proposed (for example, JP-A-8-28646 (reference 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 speed change mechanism is also an important factor, this can be applied to realize a line pressure control device compatible with input torque.

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

FIG. 6 is a consideration diagram which will be referred to also in an embodiment of the present invention which will be described later, and shows the relationship among the input torque, the line pressure (the line pressure corresponding to the input torque), and the pump noise (the oil pump noise of the unit). According to this, when uniformly depending on the method of setting the line pressure according to 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 in the figure. Since there is a relationship, as the line pressure is set higher, pump noise (sound vibration) increases.

If the line pressure is set to be low in terms of sound vibration, it is possible to satisfy the problem that the pump noise is small. But,
The line pressure is controlled to be low, and as a result, it becomes difficult to satisfy the required hydraulic pressure (hydraulic performance), which requires higher transmission torque depending on the transmission input torque. .

Particularly, in the case of the toroidal continuously variable transmission described in the above-mentioned document 1, for example, in which the necessary and appropriate supply of lubricating oil is emphasized and the line pressure control corresponding to this is required,
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, the more difficult it is to deal with it.

Therefore, it is desirable that both sound vibration and hydraulic performance can be achieved. It is also desirable to enable line pressure control in a transmission unit with a high set hydraulic pressure, or to control line pressure in a continuously variable transmission where a proper supply of lubricating oil is particularly important. The sound vibration and the hydraulic performance can be achieved at the same time, or the characteristic of the line pressure setting corresponding to the input torque is that the sound vibration and the hydraulic performance can be achieved at the same time.

The present invention is based on the above consideration and also based on the consideration described later, and is intended to be improved from those points, and it is possible to make the sound vibration and the hydraulic performance compatible with each other. It is intended to provide a line pressure control device for a transmission. Further, it is an object of the present invention 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 proper supply of lubricating oil is particularly important.

[0010]

According to the present invention, the following line pressure control device for an automatic transmission is provided. That is, the present invention is a control device for controlling a line pressure in an automatic transmission that has a speed change mechanism and is configured to include a hydraulically operated friction element, and that changes rotational power from an engine and transmits the rotational power. Determining means for determining whether the engine rotation is in a low rotation range lower than the predetermined value or in a high rotation range higher than the predetermined value, the determination means having a predetermined value for determining the engine speed; The means for controlling the line pressure based on the judgment result is used, and when it is in the high rotation range, the lubrication required for supplying the lubricating oil to the speed change mechanism is required.
The first necessary oil pressure is determined as a main hydraulic, at least, compared to the second necessary hydraulic obtained as a friction element required hydraulic pressure required in the hydraulic actuation of said friction element, depending on whichever is higher required hydraulic When the line pressure is set and the engine speed is in the low rotation range, the second hydraulic pressure is set regardless of the first required hydraulic pressure.
And a line pressure control means including a line pressure determination means for determining the line pressure so that the line pressure can be set according to the required hydraulic pressure requirement.

Further, when the speed change mechanism is a continuously variable speed change mechanism, and the line pressure control means is determined to be in the low speed range, the line pressure control means controls the continuously variable speed change by the continuously variable speed change 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 second required hydraulic pressure, and the line pressure is set according to the higher required hydraulic pressure. Further including means for determining a line pressure, and in the case of the high rotation range, the third required hydraulic pressure is further applied as a comparison target, and the first required hydraulic pressure and the second required hydraulic pressure, A line pressure control device for an automatic transmission, characterized in that the line pressure is determined so as to set the line pressure according to the highest required hydraulic pressure among the third required hydraulic pressure. is there.

Further, the judging means uses a first predetermined value and a second predetermined value larger than the first predetermined value as the predetermined value for the discrimination, and the line pressure control means uses the engine. The line pressure in the first engine rotation range where the rotation speed is lower than the first predetermined value is the low rotation range.
Set the same line pressure and when it is determined, to a high engine speed is a predetermined value or more of the second second engine speed range
It is judged that the line pressure in the
Set the same line pressure as when
Against the gender, setting the third engine line pressure to be set by the speed range, the line pressure so as not abruptly change the line pressure control characteristics between the predetermined value and the second predetermined value of engine speed is first The line pressure control device for an automatic transmission, further comprising means for determining the line pressure.

In order to set the line pressure in the third engine speed range so as not to change the line pressure control characteristic abruptly, the line pressure set value set in the first engine speed range and the line pressure set value set in the first engine speed range are set. The first engine speed range and the second engine speed range are applied by applying interpolation values obtained by linear interpolation calculation using the respective set values of the line pressure set values set in the second engine speed range. A line pressure control device for an automatic transmission, characterized in that a line pressure between the lines is set.

Further, all or a part of the required hydraulic pressure to be the target of the line pressure setting is the hydraulic pressure obtained by obtaining the respective required hydraulic pressure values according to the transmission input torque, and the automatic transmission It is the line pressure control device of the machine.

[0015]

According to the line pressure control device of the present invention, the control region is divided into the low engine speed region and the high engine speed region, and the line pressure switching control according to the present invention is performed to achieve both sound vibration and hydraulic performance. It is possible to realize the line pressure switching control by the engine speed, which can appropriately achieve the above.

According to the first aspect of the present invention, when the engine speed is higher than a predetermined engine speed , the lubricating oil is supplied to the speed change mechanism.
The required hydraulic pressure (first required hydraulic pressure) determined as the required lubrication required hydraulic pressure and at least the required hydraulic pressure (second required hydraulic pressure) determined as the friction element required hydraulic pressure are compared to each other to ensure that the higher one is higher. The line pressure can be set according to the required hydraulic pressure, and it is possible to secure the required hydraulic performance in that region, and in the low rotation range, unnecessary sound vibration is generated regardless of the required lubrication required hydraulic pressure. It is possible to reliably set the required line pressure in accordance with the required hydraulic pressure of the friction element without increasing it.

Here, when setting the line pressure, lubrication is not taken into consideration in the low speed region, but at low engine speed (for example, about 2000 rpm or less), heat generation in the speed change mechanism to which the lubricating oil is supplied is small. Therefore, even if the required lubricating oil pressure is low, there are less problems than at high rotation speed, and
In view of the relationship between the line pressure and the sound vibration (oil pump noise of the unit) based on the above consideration, the present invention is more advantageous for the effect of reducing the sound vibration. According to the present invention, line pressure control in a transmission unit having a high set oil pressure can be easily dealt with, and it is suitable for application to both a stepped automatic transmission and a continuously variable transmission.

In this case, according to the second aspect of the present invention, it is possible to achieve both sound vibration and hydraulic performance even in line pressure control in a continuously variable transmission in which proper supply of lubricating oil is particularly important. Suitable for controlling the line pressure can be realized. In this case, if it is determined to be in the low rotation range, the required hydraulic pressure (third required hydraulic pressure) and the frictional element determined as the hydraulic pressure required to be supplied as the control pressure used for the control of the continuously variable transmission. By comparing 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, and in the case of a high rotation range, the required oil pressure as the control pressure is also included. As a result of the comparison of the above three required hydraulic pressures (the first required hydraulic pressure, the second required hydraulic pressure, the third required hydraulic pressure) with the required lubrication hydraulic pressure and the friction element required hydraulic pressure, the highest required hydraulic pressure among them is determined. The line pressure can be appropriately determined so as to set the line pressure, and the sound vibration and the hydraulic performance (the first required hydraulic pressure, the second 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 be pinched with a strong force between the input / output cone disks, and the power of frictional contact with the input / output cone disk. The roller is required to supply a necessary and appropriate lubricating oil, and the required hydraulic performance including the supply of the lubricating oil is also higher than that of the engine not adopting the present invention in line pressure corresponding to the engine speed according to the present invention. By adopting variable control, a high degree of compatibility with sound vibration is also realized.

In a third aspect of the present invention, the engine rotation range (third third value) between the first predetermined value and the second predetermined value for discrimination is further included.
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 change abruptly, and it is possible to avoid stepwise changes in the sound vibration characteristics. It is possible to set the line pressure control characteristic according to the engine speed, and it is possible to achieve a higher degree of both sound vibration and hydraulic performance.

In this case, according to the present invention, the sound vibration characteristics are not changed stepwise, and for example, the straight line connecting the points a and b illustrated in FIG. 9 is changed. The line pressure control characteristic can be changed linearly to make it more effective.

According to the fifth aspect, basically, the required hydraulic pressure can be determined by the transmission input torque, and while utilizing the characteristic of the line pressure setting corresponding to the input torque, it is possible to achieve both sound vibration and hydraulic performance. Therefore, for example, in the case of a continuously variable transmission, the originally required line pressure can be appropriately changed by the friction element required oil pressure and the above required oil pressure for the continuously variable transmission control according to the input torque when the engine speed is low. .

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1, 2 and 3 exemplify an automatic transmission including 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
Is a vehicle engine, 200 is a transmission to which power is input via a torque converter, and 250 is an output shaft.

When the transmission 200 is a continuously variable transmission, this is a torque converter 201, a forward / reverse switching mechanism having a forward / reverse clutch as a friction element,
The control unit 210 has a toroidal continuously variable transmission mechanism and the like.
In addition to the shift control valve, the actuator, and the like that constitute the shift control means, a hydraulic circuit having a line pressure solenoid 215 for controlling the line pressure according to the present invention may be provided.

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 thereof.
Although not shown in FIG. 2, a forward / reverse switching mechanism is arranged on the right side of the drawing as a front stage, and a torque converter 201 is arranged further upstream thereof, and engine power is generated by the torque converter 201 and the forward / reverse switching mechanism. Transmitted in order.

First, the toroidal transmission unit, which is the main part of the continuously variable transmission, will be described. This has an input shaft 20 to which the rotation from the engine 100 is transmitted, and this input shaft is as shown in FIG. , The end far from the engine 100 is rotatably supported in the transmission case 21 via a bearing 22, and the central portion is supported in the intermediate wall 23 of the transmission case 21 by the bearing 2
4 and the hollow output shaft 25 so as to be rotatably supported. 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 so 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 sandwiching the input shaft 20 are interposed between the opposing toroidal curved surfaces of the input / output cone disks 1 and 2, and these power rollers are placed between the input / output cone disks 1 and 2. The following configuration is adopted for clamping.

That is, the loading nut 26 is screwed onto the end of the bearing (22) of the input shaft 20, and the cam disc 27 and the input cone disc 27 are rotationally engaged with the input shaft 20 by locking the loading nut 26. A loading cam 28 is interposed between the toroidal curved surface 1a of FIG. 1 and an end surface far from the toroidal curved surface 1a, and the rotation from the input shaft 20 to the cam disk 27 is transmitted to the input cone disk 1 via the loading cam 28. Where input cone disk 1
Is transmitted to the output cone disc 2 through the rotation of both power rollers 3, and the loading cam 28 generates thrust in proportion to the transmission torque during the transmission, so that the power roller 3 is placed between the input and output cone discs 1, 2. Clamp it to enable the above power transmission.

That is, the power roller 3 is pinched between the input / output cone discs 1 and 2, and the power roller 3 is sheared by the oil film between the power roller 3 and the input / output cone discs 1 and 2. Power transmission between 1 and 2 is performed. The power transmission is performed by shearing the oil film between the input / output cone discs 1 and 2 and the power roller 3 as described above.
Is required to be pinched between the input / output cone discs 1 and 2 with a strong force corresponding to the transmission torque to be transmitted, and is also necessary and appropriate for the power roller 3 that makes frictional contact with the input / output cone discs 1 and 2. The supply of the lubricating oil is required, and the lubricating system 205 supplies the lubricating oil by the line pressure control as described later.

The output cone disk 2 is wedged on the output shaft 25, and the output gear 29 is fitted on this shaft 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 / thrust bearing 30. In the end cover 31, the radial / thrust bearing 3 is separately provided.
The input shaft 20 is rotatably supported via 2. here,
The radial and thrust bearings 30, 32 are abutted against each other via a spacer 33 so that they cannot come close to each other, and they cannot be displaced relative to each other in a direction away from each other. Make it urge in the direction.
Thus, the thrust acting between the input / 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, as shown in FIG.
The trunnion 41 is rotatably supported, and the trunnion has an upper end rotatably and swingably at both ends of an upper link 43 by a spherical joint 42, and a lower end rotatably at both ends of a lower link 45 by a spherical joint 44. Connect to swing freely. Then, the upper link 43 and the lower link 45
Supports the center of the transmission case 21 in a vertically swingable manner by means of spherical joints 46 and 47 so that both trunnions 41 can be vertically moved in synchronization with each other in opposite directions.

A shift control device for shifting gears by vertically moving both trunnions 41 in synchronism with each other in opposite directions will be described below with reference to FIG. Each trunnion 41 is provided with a piston 6 for individually stroking these trunnions 41, and upper chambers 51, 52 and lower chambers 53, 54 are defined on both sides of both pistons 6, respectively. The shift control valve 5 is installed in order to control the strokes of both pistons 6 in opposite directions. Here, the shift control valve 5 includes a spool type inner valve body 5a and a sleeve type outer valve body 5b slidably fitted to each other, and the outer valve body 5b is attached to the valve outer casing 5a.
It is configured by slidably fitting to c.

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

The operation command of the shift control valve 5 is given by the actuator (step motor) 4 which responds to the actuator drive position command Asstep (step position command) as a stroke to the outer valve body 5b via the rack and pinion. With this operation command, the outer valve body 5b of the shift control valve 5
Is displaced relative to the inner valve body 5a from the neutral position to, for example, the position shown in FIG. 3 and the shift control valve 5 is opened, 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 shift control valve 5 is displaced in the opposite direction from the neutral position relative to the inner valve body 5a, the shift control valve 5 opens. , While the fluid pressure from the pressure source 55 is supplied to the chambers 51 and 54, the other chambers 52 and 53 are drained, and the two trunnions 41 are fluidized to each other through the piston 6 in the corresponding vertical direction in the drawing. It shall be displaced in the opposite direction. As a result, in both power rollers 3, the rotation axis O ₁ has the input and output cone disks 1, 2.
The position (offset amount y) is offset from a position intersecting the rotation axis O ₂ of the power roller 3 by the offset, and the power roller 3 is rotated by its own swing component force from the input / output cone disks 1 and 2. It is possible to perform continuously variable transmission by tilting (tilt angle φ) around the swing axis line O _{3 which} is orthogonal to ₁ .

During such shifting, the precess cam 7 coupled to the lower end of 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 shift link 8. It is mechanically fed back to the inner valve body 5a of the control valve 5 as indicated by x. When the gear ratio command value corresponding to the actuator drive position command Asstep to the step motor 4 is achieved by the stepless speed change, mechanical feedback via the precess cam 7 causes the internal valve body of the speed change control valve 5 to receive mechanical feedback. 5a
Then, the power roller 3 is returned to the initial neutral position relative to the outer valve body 5b, and at the same time, in both power rollers 3, the rotation axis O ₁ intersects with the rotation axes O ₂ of the input / output cone disks 1 and _2. By returning to the position, the achievement state of the gear ratio command value can be maintained.

The actuator drive position command Asstep to the step motor 4 is determined by the controller 61. Since the purpose of the control is to set the power roller tilt angle φ to a value corresponding to the gear ratio command value, the precess cam 7 basically needs to feed back only the power roller tilt angle φ. The reason why the power roller offset amount y is also fed back here is to prevent the shift control from hunting by giving a damping effect of preventing the shift control from becoming oscillatory.

The pressure source 55 is a hydraulic pressure source of the transmission control unit 210 shown in FIG. 1 as a hydraulic pressure 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. It can be configured to be provided in the circuit. Here, the hydraulic pressure source configured as described above 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 continuously variable transmission (CVT) illustrated in FIGS. And preferably, in addition to this,
It is assumed that the line pressure control targeting the CVT hydraulic pressure and the clutch hydraulic pressure is also performed.

That is, in the case of a control example for lubricating oil pressure, CVT oil pressure, and clutch oil pressure, the shift control valve 5 is made to act on the pair of input / output cone disks 1 and 2 as described above. The shift control pressure (CVT hydraulic pressure) used for the control of the continuously variable shift performed by hydraulically operating the power roller 3 via the piston 6, and the hydraulic friction element in the forward / reverse switching mechanism for the forward / reverse switching system 202. Considering the pressure (forward or reverse clutch hydraulic pressure) acting as the operating pressure (engagement pressure), and the pressure of the lubricating oil (lubricating hydraulic pressure) used for lubrication of the power roller 3 and the like by the lubricating system 205. By the duty drive control to the line pressure solenoid 215 of the line pressure control system,
The pressure shall be regulated.

The step motor 4 and the line pressure solenoid 215 are controlled by the controller 61, and as shown in FIG. 1, the controller 61 controls the signal from the throttle opening sensor 62 for detecting the engine throttle opening TVO, the vehicle speed VSP. Signal from the vehicle speed sensor 63 for detecting
Engine speed sensor 68 for detecting engine speed N _e
From the input cone sensor, and signals from other sensors, for example, a signal from an input rotation sensor that detects the rotation speed N _i (or the engine rotation speed N _e ) of the input cone disk 1, the rotation speed of the output cone disk 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 Signals and the like from the line pressure sensor are input respectively because they are controlled and detected from the internal signal of the controller 61.

The controller 61 is configured to include a microcomputer, and here it has functions such as shaping the 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 which has, an arithmetic processing circuit (CPU), various control programs such as a shift control program and a line pressure control program executed by the arithmetic processing circuit, and a storage circuit which stores and stores information such as arithmetic results and the like. RAM, ROM)
And an output circuit or the like that sends a control signal (shift command value, line pressure control command value, etc.) for driving to the step motor 4, the line pressure solenoid 215, and the like.

In the gear shift control, the controller 61 basically calculates a target gear ratio and calculates it by a gear shift control program (not shown) based on the above various input information so that the gear ratio becomes the target value. Step motor 4
It is possible to execute the shift control by determining the actuator drive position command Asstep (shift command value) to the actuator.

Then, the line pressure P_LIn the control of
The controller 61 shows an example of the flow in FIGS. 4 and 5.
Lines to be set according to the program shown in the chart
Pressure P _LCalculate the value and set the drive duty corresponding to this value.
Command to the line pressure solenoid 215 as a command pressure control command value
By doing so, the line pressure control is executed. in this case
In the following control program example,
Based on the speed VSP information, further throttle opening TVO information
In consideration of information, line pressure P at high vehicle speed_LRaise
Control to secure the amount of lubricating oil at high vehicle speed (high vehicle speed
Engine pressure UP (increase) control), and engine speed
N_eLine pressure P based on information_LCVT at low speed
Required hydraulic pressure (P_CVT) And clutch required hydraulic pressure (P_CLU)
Therefore, the oil pressure required for lubrication (P_LUB) Request
Control that balances sound vibration and hydraulic performance (engine rotation
Line pressure switching control based on the number of turns) is included.

A more specific description will be given below, including FIGS. 6 to 12. Here, FIG. 6 shows input torque, line pressure,
FIG. 7 is a diagram showing the relationship between pump noise (sound and vibration) and FIG.
[Fig. 4] is a view showing the relationship between the required oil pressures of lubrication required oil pressure, CVT required oil pressure, and clutch required oil pressure. 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 pressure P _L. Further, FIG. 10 is a vehicle speed VSP- showing a preferred example of the control range of the high vehicle speed line pressure increase control.
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, which is a region diagram by the throttle opening TVO. FIG. 12 is an explanatory diagram of a comparative example shown in comparison with FIG. 11.

Referring to FIG. 4, in this program example, first, in step S101, a setting process for line pressure P _L switching control based on the engine speed N _e is executed.

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, lubrication required oil pressure, CVT required oil pressure, clutch required oil pressure). . In particular, as shown in the consideration diagrams of FIGS. 6 and 7, the oil pressure required for lubrication, the oil pressure required for CVT,
When each required oil pressure of the clutch is determined by the input torque of the transmission as illustrated in FIG. 7, the relationship between the three elements of the transmission input torque, the line pressure, and the pump noise is shown in FIG. In order to achieve both sound vibration and hydraulic performance, it is important to note that

According to these figures, the relationship (to) in FIG.
As shown in, when simply relying on the method of setting the line pressure according to the input torque, the line pressure and the pump noise 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) is also increased (,), and on the other hand, if the line pressure is decreased, the line pressure is decreased from the viewpoint of sound vibration. When set,
Even if the pump noise can be kept small, the line pressure is controlled to be low, so the transmission torque must be compatible with the transmission input torque, and the higher the transmission torque, the higher it needs to be. 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 the present program example, compatibility of these points is achieved as follows, and FIG. 5 is a subroutine of the engine pressure-corresponding line pressure variable control for that purpose. In steps S201 to S203 of FIG. 5, three kinds of required oil pressures, that is, lubrication required oil pressure P _LUB and CVT required oil pressure P.
_CVT and clutch required oil pressure P _CLU are calculated. Here, the required hydraulic pressure P _LUB for each of the line pressure settings,
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 oil pressure P _LUB required for lubrication is

## EQU1 ## P _LUB = input torque Ti × coefficient K1 + coefficient K2 (1) Here, the expression (1) basically means that the required hydraulic pressure value can be set by the transmission input torque, and therefore can correspond to the transmission input torque (this point is expressed by the following expression (2), The same applies to (3)), and the coefficient K2 is an offset equivalent value, and for the lubrication necessary oil pressure P _LUB , the value obtained by multiplying the input torque Ti by the coefficient K1 is added to the coefficient K2 as an offset value.
Is added to calculate (see FIG. 7).

Regarding the input torque value, for example,
An output torque of the engine 100 is obtained from the throttle opening TVO and the engine speed N _e, and a value (estimated value) obtained by calculating the transmission input torque T _i by multiplying the engine output torque by the torque ratio t of the torque converter 201 is applied. The same applies to the following equations (2) and (3).

That is, the required CVT oil pressure P _CVT is

## EQU2 ## P _CVT = input torque Ti × coefficient K3 determined by the speed ratio (2) Regarding the clutch required oil pressure P _CLU , as in the case of the hydraulically operated friction element used in the transmission,

[ _Equation 3] P _CLU = input torque Ti × coefficient K4 + coefficient K5 (3) A value obtained by multiplying the input torque Ti by the coefficient K4 is given by
The coefficient K5 as an offset value is added to the calculation (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 calculation required hydraulic pressure data at that time.

Next, in step S204 and thereafter, a predetermined value for determining the engine speed is used, and basically, it is determined whether the engine speed is in the low speed range or the high speed range, and the high speed is determined. If the calculated lubrication required oil pressure value P _{LUB in} step S201 is high, the line pressure is set according to the P _LUB value, while low lubrication is taken into consideration. If the area is
It is sufficient to meet the required required hydraulic pressure at low engine speed (here, the calculated CVT required hydraulic pressure P _CVT value in step S202 and the calculated clutch required hydraulic pressure P _CLU value in step S203) regardless of the _LUB value. The line pressure is set, and the processing for determining the set line pressure (P _L (e)) in this subroutine is executed.

In this case, when setting the line pressure,
In the low speed range, lubrication is not considered, but this is
At low engine speed (for example, about 2000 rpm or less)
Generates less heat (in the case of this example, heat generation in the power roller 3), so even if the required lubricating oil pressure is low, there is less problem than at high rotation, and the line pressure and pump noise ( viewed from sound vibration) of the relationship, but also based on the idea of favor by effect of sound vibration reduction (in the low speed region, especially, the hydraulic pressure (line pressure to a level that the above-described lubricating required oil pressure P _L ), The line pressure P _L is determined from the CVT and the required oil pressure of the clutch in this region, as long as it is normally rotated (pump driven). It is something to do). Therefore, also in this way, according to the present control, while achieving compatibility with sound vibration, as shown in FIG. 8, the clutch required oil pressure P _CLU (Equation (3) ) And CVT required hydraulic pressure P _CVT
The originally required line pressure can be appropriately changed by (Equation (2)) (FIG. 8). Basically, even in this control, the required oil pressure is determined by the input torque, but as described above, the set value is a straight line at the time of low rotation, so the actually required oil pressure is low. Therefore, the control is divided between the low rotation speed and the high rotation speed, and the control is based on the engine rotation speed.

In this program example, the engine
The predetermined rotation speed value N for the first determination is used to determine the rolling range._e(a)
And a predetermined rotation speed value N for the second determination larger than this
_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) Determine if it is lower, and if lower,
(N_e≦ N_e(a)), execute the processing in block A in the figure
To do. That is, in step S211, the calculated CV is further calculated.
T Required hydraulic pressure P_CVTCalculated clutch required oil pressure P_CLUWho
Is large (high) or not (P_CVT≤P_CLU),
As a result of comparing the two, the calculated CVT required hydraulic pressure P_CVTIs large
If (the answer in step S211 is No), the P_CVTThe value
Set line pressure value P_LSet as (e) (step S21
2), Calculation clutch required oil pressure P_CLUIs larger (
Answer S211 is Yes), P_CLUSet value
Pressure value P_LIt is set as (e) (step S213).

The engine speed N _e is the first predetermined value N _e
When higher than (a) (No in step S204)
Further determines in step S205 whether the engine speed N _e is lower than the second predetermined value N _e (b). If it is lower (the answer in step S205 is Yes), the engine speed N _e is If the engine speed range is the engine speed between these predetermined values N _e (a) and N _e (b), then (N _e (a) <N
_e <N _e (b)), the process proceeds to the interpolation calculation process (step S231) while 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 hydraulic pressure P _CVT is large (No in step S221), the P _CVT 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 (Yes in step S221), whether or not the calculated lubrication required oil pressure P _LUB is larger (higher) than the calculated clutch required oil pressure P _CLU in step S223 (P _CLU ≤ P
_LUB ) is determined and the two are compared, and as a result, if the calculated clutch required oil pressure P _CLU is large (the answer in step S223 is N
o), set the P _CLU value as the set line pressure value P _L (e) (step S224), and if the calculated lubrication necessary oil pressure P _LUB is large (Yes in step S223), then set P
_{The LUB} value is set as the set line pressure value P _L (e) (step S225).

Here, the engine speed N _e is a predetermined value N _e.
(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, they may be higher than the calculated lubrication required oil pressure P _LUB. Therefore, the highest one of these three is selected so that the line pressure can be set.

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

[0057]

[Equation 4] 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

As shown in FIG. 9, the setting process as described above is performed by using the two discriminating values N _e (a) and N _e (b) relating to the engine speed. Between the point a and the point b, the straight line connecting the points a and b is changed (engine speed N _e − in order to change the sound vibration performance stepwise.
In view of the line pressure P _L characteristic, the line pressure is gradually changed from P _L ′ to P _L ″), and the line pressure control characteristic is made to be a linear characteristic.

Basically, as described above, this control is performed by dividing the engine low speed region and the engine high speed region so that line pressure switching control can be performed to achieve both sound vibration and hydraulic performance. However, in the low speed range and the high speed range, the target of the required hydraulic pressure applied to the line pressure setting is different (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 range and the value P _L (e) is set by this value, while in the low rotation speed range, it is different. Considering that there is a case where the higher one of the CVT required oil pressure P _CVT value and the calculated clutch required oil pressure P _CLU value is selected and the value P _L (e) is set), When only one kind of different value is set and used to divide the engine rotation range into the low range and the high range (low range, middle and high range), that is, for example, a predetermined value N _e (a in FIG. 9 is assumed. ) Is set as the discriminant value (or, conversely, only the predetermined value N _e (a) is discriminated), and when the regions are divided, the discriminant 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,
It has a characteristic of rapidly changing discontinuously in steps.

However, even though this basically achieves both sound vibration and hydraulic performance, that is, suppression of sound vibration (pump noise) and securing of the required hydraulic pressure, it is basically achieved.
However, the sound vibration characteristics change stepwise before and after the engine speed N _e . Therefore, it is more desirable to avoid the occurrence of such a phenomenon. Therefore, in the present program example, the above-described method, which can be the line pressure setting characteristic including the setting characteristic between points ab as illustrated in FIG. 9, is also introduced.

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

The engine 100 is in a high rotation range (here, N
_{If e} ≧ N _e (b)), the lubrication required to supply the lubricating oil to the toroidal type continuously variable transmission shown in FIGS.
By comparing the required hydraulic pressure calculated by equation (1) as the hydraulic pressure P _LUB and the required hydraulic pressure to be compared with this, the line pressure can be reliably set according to the higher required hydraulic pressure, It is possible to secure good hydraulic performance (block B), and also in a low rotation range (here, N _e ≦ N _e
In the case of (a)), the line pressure necessary for the calculation of other required hydraulic pressure is ensured without unnecessarily increasing the sound vibration regardless of the required lubricating oil pressure P _LUB. Can be set to (block A).

Therefore, when it is judged that the engine speed is in the low speed range, the CVT required oil pressure P _CVT obtained by the equation (2) is obtained.
And the clutch required oil pressure P _CLU obtained by the equation (3) are compared with each other, and the line pressure can be appropriately determined so that the line pressure is set according to the higher required oil pressure. In the case of the range, the required lubrication oil pressure P _LUB is further applied as a comparison target, and the required lubrication oil pressure P _LUB , the CVT required oil pressure P _CVT and the clutch required oil pressure P _CLU are compared, and the highest required oil pressure among them is calculated. The line pressure can be appropriately determined so that the line pressure is set according to In the toroidal type transmission unit, the power roller 3 is pinched between the input / output cone disks 1 and 2, and the oil film is sheared between the power roller 3 and the input / output cone disks 1 and 2 to cause input / output cone disks 1 and 2. In the case of transmitting power between the power rollers 3, the power roller 3 needs to be sandwiched between the input / output cone disks 1, 2 with a strong force corresponding to the transfer torque, and the power roller 3 is in frictional contact with the input / output cone disks 1, 2. 3 requires a proper supply of lubricating oil. Regarding the required hydraulic performance including the supply of such lubricating oil, this line pressure control achieves a high degree of compatibility with sound vibration characteristics, that is, hydraulic pump noise. Is also realized.

When applied to a stepped automatic transmission,
As a supplementary note, for the stepped automatic transmission,
CVT (continuously variable transmission) required oil out of the required oil pressure
Pressure P _CVTIs not present, the oil pressure required for lubrication is high
Only in the case of the area, it is necessary to apply it for comparison and lubricate it.
Hydraulic pressure and friction elements for shifting (hydraulic clutch, hydraulic brake
The line pressure is set by the higher of the required hydraulic pressure
In the low rotation speed range,
First, calculate the necessary frictional element for gear shifting.
If there are multiple required hydraulic pressures for the shifting friction element,
The higher one) will be used to set the line pressure.
(To find those oil pressures required for lubrication and friction elements for shifting,
Therefore, it may be in accordance with the formulas (1) and (3)).

Further, the first predetermined value N _e (a) and the first predetermined value N _e (a) are used as the predetermined value for the determination regarding the engine speed N _e for judging whether the engine rotation is in the low rotation range or the high rotation range. In this program example using the large second predetermined value N _e (b), the low engine speed range (first engine speed range) equal to or lower than the predetermined value N _e (a) and the predetermined value N _e (b) or higher. Corresponds to high engine speed range (second engine speed range) respectively. Line pressure can be set according to required oil pressure, and
In the engine speed range (third engine speed range) between the predetermined value N _e (a) and the predetermined value N _e (b), the line pressure is controlled by setting the line pressure so as not to change abruptly. It is also possible to avoid stepwise changes in sound and vibration characteristics, and it is possible to make finer adjustments to the line pressure control characteristics based on engine speed, aiming for a higher degree of both sound and vibration performance. be able to.

In this case, as shown in equation (4), the respective set line pressure values in the engine rotation range of the predetermined value N _e (a) or less and the engine rotation range of the predetermined value N _e (b) or more are By applying the interpolation value obtained by the linear interpolation calculation using the line pressure in the engine rotation range between the predetermined values N _e (a) and N _e (b), the sound vibration characteristic changes stepwise. It is possible to obtain a more effective characteristic without changing the linear characteristic such as changing the straight line connecting the points a and b in FIG.

The method for preventing the stepwise change of the sound vibration characteristics as described above can be applied even when the line pressure control is applied to the stepped automatic transmission as described above. Here, in that case, similarly to the above, the first predetermined value and the second predetermined value larger than the first predetermined value are used as the predetermined values for the determination, and the first predetermined value is used. Line pressure is set in accordance with the required lubrication oil pressure in a first engine speed range equal to or lower than a predetermined value of, and in accordance with a calculated necessary oil pressure of the speed change friction element in a second engine speed range equal to or higher than the second predetermined value. When the line pressure is set, the line pressure setting in the third engine speed range between the first predetermined value and the second predetermined value is performed by the interpolation calculation similar to the above, and the line pressure control characteristic is set. The line pressure can be determined so that the line pressure is set so as not to change suddenly.

Returning to FIG. 4, in step S101,
The vehicle speed VSP is a predetermined vehicle speed VS as shown in FIGS.
This is a step of determining whether or not P1 or more. In the present program example, the determination steps of step S102 and step S103 are additionally provided as the determination step. In step S102, the vehicle speed VSP is as shown in FIG.
This is selected when it is determined that the vehicle speed is equal to or higher than the predetermined vehicle speed VSP1 as shown in 0 (the answer in step S101 is Yes), and the throttle opening TVO of the engine 100 is near the fully closed position as illustrated in FIG. Is a step (whether it is less than a predetermined low opening TVOc).

In step S103, when the answer to step S101 is Yes and the answer to step S102 is No (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 fully closed). If not, the set line pressure value P _L (e) obtained in the line pressure variable control process (step S100) by the engine speed N _e and the high vehicle speed in step S110 are selected. This is a step for comparison and judgment 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 that is a target value for the line pressure increase control in order to uniformly increase (dramatically greatly increase) the line pressure P _L. It can be (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)) In step S111, step S111 is selected. In this case, P
Let _L = some high value P _LH (constant). So this is
It is applied as the line pressure P _L value to be set.

Therefore, in this program example, the line pressure increase control by the setting process in step S110 is basically selected with respect to the vehicle speed VSP under the condition of the predetermined vehicle speed VSP1 or more, and the vehicle speed less than the predetermined vehicle speed VSP1. Then, as a result that the main line pressure increase control is not executed (P _L = other line pressure control value other than the main line pressure increase control (second line pressure control value)) is selected (line pressure). Prohibition control of the ascending control), which is executed in the high vehicle speed range. 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 commanded to the line pressure solenoid 215 as the line pressure control command value to execute the line pressure control. When going, it is possible to surely increase the line pressure P _L to a constant pressure P _LH when the vehicle speed is higher than the predetermined vehicle speed VSP1, and it is possible to realize control that secures the lubricating oil amount at the time of the high vehicle speed. Therefore, even when operating on a high speed road where high rotation and high torque continue for a long time, the heat generation of the heat generating portion of the transmission mechanism, and thus the increase in the oil temperature of the power roller 3, can be suppressed well.

The purpose of the control for increasing the line pressure P _L at high vehicle speed is to prioritize the control of the amount of lubricating oil, which is skillfully harmonized with the fuel consumption and the like. This is based on the following points, which will be further supplemented and explained. First, in the control at a low vehicle speed lower than the predetermined vehicle speed VSP1, basically, the characteristic tendency illustrated in the consideration FIG. 7 may be followed, and therefore, the line pressure value according to the transmission input torque. (Refer to the above equations (1) to (3)), the line pressure can be basically determined by the transmission input torque, and the line pressure setting corresponding to the input torque is characterized by This will make the most of this.

Specifically, the highest hydraulic pressure of the required hydraulic pressures shown in FIG. 7 can be set as the line pressure. Basically, in the control at the low vehicle speed, the main line pressure increase control is performed. Even when adopting, the lubrication required oil pressure P _LUB (equivalent to the lubrication required oil amount), CVT required oil pressure P _CVT , clutch required oil pressure P _CLU
You can choose the highest one. By doing this, the line pressure is determined so that the line pressure P _L is set by selecting the highest required hydraulic pressure among the calculated hydraulic pressures, and the line pressure P _L control at low vehicle speed can be achieved. And, at that time, the required hydraulic pressure (line pressure set value P _L (e) which is determined in accordance with the input torque as described above.
The line pressure originally required by) can be changed appropriately.

Therefore, the line pressure control at low vehicle speed can be controlled according to the required hydraulic pressure, but if the vehicle speed (low vehicle speed, high vehicle speed) is not satisfied, the input torque can be handled 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 of FIG. 12 are shown with the vertical axis representing the line pressure P _L and the horizontal axis representing the vehicle speed VSP. In the case of the maximum torque (torque MAX), the curve characteristics in the upper part of the figure are as shown. Also, the minimum torque (torque MIN)
In the case of, it can be expressed as the characteristic at the bottom of 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) necessary for lubrication should increase proportionally to the right as the vehicle speed VSP increases, as shown by the lower solid line. Is likely to be inadequate for the amount of oil (or, in terms of line pressure, inadequate for hydraulic pressure), and the amount of oil required for lubrication may not be sufficient at the above hydraulic pressure setting at high vehicle speeds. In consideration of this, the line pressure control according to this program example adds the line pressure increase control.

The amount of lubricating oil increases because the temperature of the heat generating portion (oil temperature of the power roller in the case of a toroidal type continuously variable transmission) rises when the high torque and high torque generation state continues for a long time. High rotation, which is necessary to lower the temperature of
High torque continues for long periods on highways. Therefore, a control is added to appropriately increase the line pressure P _L at high vehicle speed to increase the amount of lubricating oil.

Here, it is preferable that the line pressure P _{L be} increased as shown in FIG. In this example, the line pressure P determined by the input torque
Is intended to increase the _L of the set value, is a control that measures a flow rate insufficient line pressure P _L increases with the partial region,
In this case, the line pressure set value is set to the predetermined vehicle speed VSP.
In a vehicle speed range of 1 or more, a predetermined high constant line pressure value,
Here, it is performed by switching to a value corresponding 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 bounce-back caused by always using the torque MAX includes the point of fuel consumption, but the amount of lubricating oil is prioritized and the torque is always equivalent to the torque MAX. Even when there is a situation (for example, when the foot is released from the accelerator pedal), by constantly increasing the amount of oil, the heat generated by the power roller 3 in the toroidal transmission unit, which is the heat generating portion, is positively generated. I have lowered it).

In FIG. 11, the vehicle speed V in the process of increasing the vehicle speed
When SP1 is reached, for example, in terms of the relationship with the lower solid line characteristic (torque MIN) in FIG. 12, even if the line pressure P _L is increased more than that, it is not possible to flow a large amount of lubricating oil. , The unit (toroidal type transmission unit) works in the direction of increasing the durability. On the other hand, even if the line pressure P _L suddenly rises, it is still running, so N → There is no problem of shock such as D shock, and overall, the continuously variable transmission system employing the line pressure increase control will work advantageously. Also, fuel economy,
Further, regarding the aspect of sound vibration, this is also taken into consideration, and basically, this control is prohibited in an operation region other than the target region of this control (the answer in step S101 is No.
→ S111, the answer to step S102 is Yes → S11
1) On the other hand, the region of this control is less stringent in terms of fuel consumption than the region of low rotation, where fuel consumption and sound vibration are relatively important, and it can be said that the influence on fuel consumption is small. Therefore, when these are combined, including such aspects as fuel consumption,
This is advantageous for the entire continuously variable transmission system mounted on the vehicle.

In step S102 of FIG. 4, when the throttle opening TVO is near the fully closed position, the step S110 side is not selected, but the step S111 side is selected. As a result, even when the vehicle is traveling at the vehicle speed VSP equal to or higher than the predetermined vehicle speed VSP1, at this time, the main line pressure increase control is not executed (line pressure increase control prohibition control). In this case, the execution region of the main line pressure P _L increase control can be a shaded region in FIG. 10 (“P _L up” region), 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 if another second line pressure control is incorporated as something to be executed near the fully closed position of the VO, it is possible to reliably prevent control interference, for example, the line pressure set values conflict with each other.

In this program example, step S11
In 1, P _L = with processing other line pressure control value, if the setting of the line pressure is made, other than the line pressure P _L increases control, control the other line pressure (line pressure according to the engine rotational speed P _L The target region that is the target of the second line pressure P _L control executed as the switching control (including step S100) is as follows.

[1] Region where the vehicle speed VSP is lower than the predetermined vehicle speed VSP1, [2] Vehicle speed VSP is equal to or higher than the predetermined vehicle speed VSP1,
In addition, the throttle opening TVO is an area where the throttle opening TVO is an opening (including fully closed) near the fully closed state, and further, step S103.
[3] Vehicle speed VSP is equal to or higher than the predetermined vehicle speed VSP1 and the throttle opening TVO is in a region other than near the fully closed state (that is, P _L (e)> P _LH ). , “P _L up” area in FIG. 10) is also a target. In this case, by combining the second line pressure control with the second line pressure control, the line pressure control can be performed by the main line pressure P _L described above.
It is possible to make more comprehensive and integrated finer control including the ascending control. In this case, as the second line pressure control, the following control is executed in this program example.

In the above [1], the line pressure control at low vehicle speed is performed, and as described above, the oil pressure P required for lubrication is set.
_LUB , CVT required oil pressure P _CVT , clutch required oil pressure P _CLU
Based on the one selected from the above, the line pressure P _L
Control can be performed (see FIG. 10). In particular,
More preferably, the line pressure P _L control corresponding to the engine speed according to the process of the above-described subroutine (steps S201 to S231) of FIG. 5 can be performed. In this case, the line pressure switching function based on the engine speed N _e can be used in combination, and the line pressure control region can be divided into the low speed region and the high speed region of the engine speed in addition to the vehicle speed VSP, thereby providing a finer line. Pressure control is possible and P
_As a processing of _L = another line pressure control value, the P _L (e) value calculated by the subroutine in FIG. 5 is applied as P _L = P _L (e) and the line pressure control is executed, resulting in engine rotation. The above-described advantages of the variable line pressure P _L variable control can be utilized to achieve both sound vibration and hydraulic performance.

As the second line pressure P _L control in the above [2], when the throttle opening TVO is fully closed, a line pressure reduction control for reducing the line pressure P _L is executed. Even if the continuously variable transmission is selected for the high gear ratio (small gear ratio side), it is continuously downshifted to the low gear ratio (high gear ratio side) as the input rotation and the vehicle speed decrease due to full closure. Therefore, in view of this, the second line pressure P _L control is to prevent the line pressure from being high and a sudden low-down shift during coasting. Therefore, according to this, the main line pressure increase control prohibits this during coasting, but unlike the line pressure increase control, the second line pressure P _L that actively reduces the line pressure is used.
Total control of line pressure including control can be realized, and vehicle speed V
Even if SP is equal to or higher than the predetermined vehicle speed VSP1, the sudden low-down shift can be reliably avoided, which is a suitable fail-safe measure. Moreover, the interference with the fail-safe can be surely prevented, and in this case, this becomes higher than the priority of the lubricating oil amount, and such fail-safe control top priority can be realized.

In the second line pressure P _L control in [3], the set line pressure P _L (e) value calculated by the engine speed-corresponding line pressure P _L control process and the main line pressure P _L increase control are performed. Is executed based on the result of the comparison with the line pressure value P _LH to be applied in the above, and by the setting process of P _L = P _L (e) under the condition of P _L (e)> P _LH , The line pressure P _L control corresponding to the engine speed corresponds to the second line pressure P _L.
It will be executed as a control. That is, as a result of the comparison, under the condition of P _LH ≧ P _L (e), the above-described 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. In this way, between said engine speed corresponding line pressure P _L control as the line pressure increase control and the second line pressure P _L control,
Both of these can be achieved, and optimization as a comprehensive line pressure control becomes possible.

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

In a stepped automatic transmission, the transmission 20
0 (FIG. 1) has a friction element for shifting such as a hydraulic clutch and a hydraulic brake in the speed change mechanism, and directly controls the operating hydraulic pressure value of the friction element. Also in the transmission, for example, a unit having a design concept with a high set oil pressure, where lubrication is an important factor, may require similar control, and is effectively applied in 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 according to the engine speed are used in combination has been described, but it goes without saying that the present invention is not limited to this mode. Yes. Therefore, it is needless to say that the present invention can be implemented in a mode in which only the line pressure switching control based on the engine speed is executed to achieve the above-described operational effects of the present control.

[Brief description of drawings]

FIG. 1 is a diagram showing 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 vertical sectional side view of an applicable toroidal type continuously variable transmission.

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

FIG. 4 is a flowchart showing an example of a line pressure control program executed by a controller in the same 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 for explaining the line pressure control by the control program, and is a consideration diagram showing the relationship between the input torque, the line pressure, and the pump noise (sound vibration).

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

[8] Also, the input rotation speed represents the basic principle of the engine speed corresponding variable line pressure control - is a characteristic diagram of the line pressure P _L.

FIG. 9 is a characteristic diagram of engine speed N _e −line pressure P _L , similarly showing an example of preferable contents of the set hydraulic pressure by the line pressure variable control corresponding to the engine speed.

FIG. 10 is a control region diagram by a vehicle speed VSP-throttle opening TVO showing an example of a suitable control region for high vehicle speed line pressure increase control.

FIG. 11 is a characteristic diagram of vehicle speed VSP-line pressure P _L , similarly showing an example of preferable contents of the set hydraulic pressure by high vehicle speed line pressure up control.

FIG. 12 is likewise an explanatory view of a comparative example shown in comparison with FIG. 11.

[Explanation of symbols]

1 input cone disc 2 output cone disc 3 power rollers 4-step motor (shift actuator) 5 shift control valve 6 pistons 7 Precessum 8 speed change 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

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI F16H 63:06 F16H 63:06 (56) References JP-A-8-28646 (JP, A) JP-A-7-269687 (JP , A) JP 7-83320 (JP, A) JP 7-71586 (JP, A) JP 6-109121 (JP, A) JP 5-118417 (JP, A) JP 5-149418 (JP, A) JP 5-118424 (JP, A) JP 3-204472 (JP, A) JP 63-188535 (JP, A) JP 63-203437 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (5)

(57) [Claims] 1. A control device for controlling a line pressure in an automatic transmission which has a speed change mechanism and includes a hydraulically operated friction element, and which changes and transmits rotational power from an engine. Determination means for determining whether the engine speed is in a low rotation range lower than the predetermined value or a high rotation range higher than the predetermined value, and a determination result by the determination means. in the means for controlling the line pressure on the basis of, in the case of the high speed range, the transmission
The first required hydraulic pressure required as the required lubricating oil pressure required to supply the lubricating oil to the structure is compared with at least the second required hydraulic pressure required as the required friction element required hydraulic pressure for the hydraulic operation of the friction element. The line pressure is set according to the higher required hydraulic pressure, and the line pressure is set according to the second required hydraulic pressure request regardless of the first required hydraulic pressure in the low rotation range. A line pressure control device for an automatic transmission, comprising line pressure control means including line pressure determination means for determining a line pressure. 2. The continuously variable transmission mechanism according to claim 1, wherein the transmission mechanism is a continuously variable transmission mechanism, and when the line pressure control means is determined to be in the low rotation range. A third required hydraulic pressure, which is required as a hydraulic pressure required to be supplied as a control pressure used for controlling the shift, is compared with the second required hydraulic pressure, and the line is determined according to the higher required hydraulic pressure. Means for determining the line pressure so as to set the pressure, and in the case of the high rotation range, the third required hydraulic pressure is further applied as a comparison target, and the first required hydraulic pressure and the second required hydraulic pressure are applied. Of the required hydraulic pressure and the third required hydraulic pressure, and determines the line pressure so as to set the line pressure in accordance with the highest required hydraulic pressure among them. Line pressure control device. 3. The determination means, as the predetermined value for the determination, a first predetermined value and a second predetermined value larger than the first predetermined value.
And a predetermined value of, the line pressure control means sets the line pressure in the low engine speed range as a line pressure in a first engine engine speed range where the engine speed is lower than the first engine speed value.
It is determined that the same line pressure as in the case where it is determined that the engine speed is in the high engine speed range is set as the line pressure in the second engine engine speed range that is higher than the second predetermined value.
Set the same line pressure and when it is, against these line pressure setting characteristics line engine speed set by the third engine speed region between the predetermined value and the second predetermined value of said first pressure The line of the automatic transmission according to claim 1 or 2, further comprising means for determining the line pressure so as to set the line pressure so as not to change the line pressure control characteristic abruptly. Pressure control device. 4. The line pressure set value set in the first engine speed range and the line pressure set value set in the first engine speed range in order to set the line pressure in the third engine speed range so as not to change the line pressure control characteristic abruptly. The first engine speed range and the second engine speed range are applied by applying interpolation values obtained by linear interpolation calculation using the respective set values of the line pressure set values set in 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 method according to claim 1, wherein all or some of the required hydraulic pressures to be set for the line pressure are obtained by obtaining respective required hydraulic pressure values according to a transmission input torque. A line pressure control device for an automatic transmission, characterized in that the hydraulic pressure is controlled.