JP3484812B2 - Control device for continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to, for example, a power source (engine).
Control device for the continuously variable transmission interposed between the drive shaft
It relates to the improvement technology of the installation. [0002] 2. Description of the Related Art For example, the effective diameter is continuously variable.
One pulley and a belt wound between both pulleys,
The line pressure is applied to one pulley actuator.
And the other pulley actuator
The line pressure is used as the base pressure and
Supply the adjusted hydraulic pressure (oil amount) to perform continuously variable transmission.
Transmission control device of a continuously variable transmission (CVT).
And the line pressure is set so as to satisfy the following requirements.
Generally, it is done. That is,   The belt should not slip. → Higher line pressure is better
No.   Excessive belt pressing force deteriorates the durability of each part
And the rotational friction must not be excessive. → Line
The lower the pressure, the better.   Fuel consumption should not deteriorate due to oil pump loss.
→ The lower the line pressure, the better. [0004] Further, at the time of a shift transition such as a downshift, etc.
At the time of shift transition so that the belt does not slip at
Temporary line pressure during shifting
Is raised, for example, Japanese Patent Publication No. 63-661
And Japanese Patent Publication No. 5-50615. [0005] SUMMARY OF THE INVENTION However, the line
The discharge rate of the oil pump that generates the original pressure of the pressure decreases.
In the low rotation region (for example, 1200 rpm or less), FIG.
As shown in (1), a rise in hydraulic pressure is temporarily delayed. Dow
During the shift, the control oil of one (primary side) pulley is
Pressure (gear pressure) to reduce the
Base line pressure (secondary pulley control oil
If the rise in pressure) is delayed, it will work to maintain the target gear ratio.
The primary side shifting pressure drops,
Therefore, slippage of the belt occurs. On the other hand, Japanese Patent Application Laid-Open No.
According to the report, in the low rotation range where the oil pump discharge decreases
Restricts the shift speed to a predetermined value or less and
It is disclosed to prevent the pressure from dropping. Only
And respond by limiting the shifting speed as described above.
Driver wants to change gears quickly,
Shifting will result in a slow shift even if you step
It is not preferable in driving feeling. The present invention has been made in view of such a conventional problem.
The contact pressure between each rotating member and the power transmission member
Reduce the gear speed by properly controlling
Good gear shifting without slippage of the power transmission member
To provide a control device for a continuously variable transmission.
Target. [0008] According to the first aspect of the present invention, there is provided:
According to the invention, as shown by a solid line in FIG.
And the driven-side rotating member, and interposed between them,
And a power transmission member for transmitting power with
Control the contact surface pressure between the member and the power transmission member as the line pressure
And the contact pressure between the other rotating member and the power transmission member is
The line pressure is controlled as a gear pressure adjusted according to the target gear ratio.
By controlling the rotation, the power
The ratio of the radius to the point of contact with the transmission member is changed steplessly.
Control device for continuously variable transmission
And the conditions for abrupt shifting in the direction of decreasing the shifting pressure are detected.
Outgoing sudden shift condition detecting means, and the sudden shift condition detecting means
When the rapid shift condition is detected by
Line pressure increase control means for increasing the pressure for a predetermined period;
Start of line pressure increase control by line pressure increase control means
Then, a line for detecting a condition that causes a delay in the rise of the line pressure occurs.
In-pressure rise delay condition detecting means, and the line pressure rise delay
The line pressure rise delay occurs due to the condition detecting means.
When the condition is detected, it corresponds to the delay in the rise of the line pressure.
PeriodAnd then adjust the line pressure according to the target gear ratio.
Control in the direction of reducing the shift pressure by adjusting
StartTransmission pressure reduction control delay means
It is characterized by having done. Further, the invention according to claim 2 is the same as that shown in FIG.
Calculates the shift speed to the target gear ratio as shown in
Shifting speed calculating means, wherein the rapid shifting condition detecting means comprises:
The shift speed calculated by the shift speed calculating means is equal to or higher than a predetermined value.
A large state is defined as a rapid shift condition for decreasing the shift pressure.
It is characterized by detecting. The invention according to claim 3 has one point in FIG.
As shown by the chain line, the continuously variable transmission is mounted on the vehicle,
The line pressure is controlled by the oil driven by the prime mover
When the pressure is adjusted using the discharge oil pressure from the
In addition, a rotation speed detection method that detects the rotation speed of the oil pump
And a line pressure rise delay condition detecting means,
When the rotational speed of the oil pump is lower than
To detect as a condition that causes a delay in the rise of the in-pressure.
Features. The invention according to claim 4 has two points in FIG.
As indicated by the dashed line, a line pressure detection for detecting the line pressure
Output means, and the shift pressure reduction control delay means includes
When the line pressure detected by the in-pressure detecting means is equal to or higher than a predetermined value.
Delaying the shift pressure reduction control until the
It is characterized by. [0012] According to the first aspect of the present invention, a rapid shift condition detection is performed.
Gear shift in the direction in which the means reduces the gear shift pressure, for example, drive side rotation
When the members are controlled by the shifting pressure, it is a downshift,
Conditions for performing sudden shifts of a predetermined speed or more (For a vehicle transmission,
(During sudden acceleration), the line pressure increase control
By increasing the line pressure for a predetermined period,
Speed set in accordance with the target gear ratio based on engine pressure
Prevents pressure drop and suppresses belt slippage. However, a condition that causes a delay in the rise of the line pressure may occur.
In this case, during the delay in the rise of the line pressure, the
Since the set shift pressure will decrease,
When the shift pressure rise delay detecting means detects the
At least the line pressure rise delay period by control delay means
During this time, the control to reduce the shift pressure is delayed
Prevent pressure drop. As described above, during the line pressure rise delay period,
Controlled by the shift pressure by preventing the shift pressure from decreasing
Slip between the rotating member on the side and the power transmission member is prevented, and it is durable
Can be prevented from decreasing. Also, the delay in line pressure rise
It is only necessary to delay the shift pressure reduction control by the appropriate period.
When shifting more than necessary, as in the method of limiting the shifting speed
There is no delay. According to the second aspect of the present invention, the transmission
The speed is calculated by the speed calculation means.
Slip between rotating member and power transmission member controlled by pressure
Only increase the line pressure when the speed
It can be detected as an increasing sudden shift condition,
It is not necessary to perform line pressure increase control without the need. Also, billing
According to the third aspect of the invention, the rotation speed is detected by the rotation speed detection means.
When the rotation speed of the oil pump
Is the source pressure of the line pressure even if the control to increase the line pressure is performed.
The oil pump discharge pressure is
Since this causes a delay in the rise of the pressure,
And delays the shift pressure reduction control only when necessary
be able to. According to the fourth aspect of the present invention, the line
Until the line pressure reaches a predetermined value by the
Only the shift pressure reduction control needs to be delayed.
The time can be kept to a minimum. [0017] Embodiments of the present invention will be described below. Figure 2 is a book
FIG. 1 is a system diagram of an embodiment of the present invention. Engine 1 output
On the side, a long travel damper (spring type for absorbing rotation fluctuation)
A continuously variable transmission (CVT) 3 is provided via a damper 2.
Have been. The starting clutch 15 described later is an engine.
1 and the continuously variable transmission 3
In the system with an inverter, the long travel
The damper 2 can be omitted. A continuously variable transmission (CVT) 3 is provided on the engine 1 side.
Primary pulley 4 as a driving-side rotating member,
Secondary shaft as a driven side rotating member on the shaft (diff) side
And rubber or metal wound between them,
Or as a power transmission member consisting of a combination of these
And the primary pulley side actuator
Gear 4a (shift control hydraulic chamber) and a second gear
To the pulley-side actuator 5a (hydraulic chamber for tension control)
The pulley ratio (secondary pulley
Side belt winding effective diameter / Primary pulley side belt winding
Change the gear ratio in a stepless manner.
That can be done. However, known toroids
Other CVTs, such as equations, can also be used. That is, stepless change
The speed unit 3 includes a driving-side rotating member that receives the rotating force of the power source,
Driven side rotating members and power transmission interposed between them
And the power transmission from the center of rotation of each rotating member.
By changing the ratio of the radius up to the contact point with the
Even if it is a continuously variable transmission that controls the gear ratio continuously.
Just fine. The shift pressure and the line pressure are applied to the oil pump 7.
Each hydraulic path provided inside the connected hydraulic circuit 8 (for example,
For example, a solenoid valve having a relief function
It is interposed in the hydraulic path together with the opening and closing of 9, 10 etc.
Adjustment via flow control valves for shifting pressure and line pressure control
The drive control of the solenoid valves 9 and 10 and the flow control valve
The control is controlled by the controller 11. That is, the change required according to the running conditions and the like.
In order to achieve the speed ratio, the controller 11
Shift pressure and line pressure via valves 9 and 10 and flow control valve
And the gear ratio is controlled to the target value.
You. Note that the solenoid valves 9 and 10 and the flow control valve are
It consists of a number of solenoid valves, and the opening and closing combination of multiple solenoid valves
To achieve the target shift pressure and line pressure.
Can also be configured. The output side of the continuously variable transmission 3 (secondary transmission)
Start between pulley 5) and drive shaft side (for example, differential)
The clutch 15 is interposed.
The clutch pressure to the solenoid is controlled by a solenoid valve 16.
The valve 16 is also controlled by the controller 11.
ing. It should be noted that the controller 11 does not
Function as speed change calculating means and pressure control means. For controlling the gear ratio and the line pressure, the control
Roller 11 has an actual input rotational speed Nin (d
To detect the rotational speed (Ne) of the engine 3
Generates a pulse signal in synchronization with the rotation of the mari pulley 4)
The input output rotation sensor 12 and the actual output rotation speed of the continuously variable transmission 3
Rotation of output side (secondary pulley 5) to detect No
Output-side rotation sensor 1 that generates a pulse signal in synchronization with
3. Opening of the throttle valve of engine 1 (throttle opening
Degree) Potentiometer that generates a voltage signal corresponding to TVO
Detection signals from the data-type throttle sensor 14 etc.
No. has been entered. In addition, as the input side rotation sensor 12,
Is the engine rotation sensor and the output side rotation sensor 13
A vehicle speed sensor can be used. FIG.
4 shows a main routine at the time of a gear change to be performed. Step (Figure
Then, it is described as S. The same applies to 101).
The rotational speed Ne of the engine 3 detected by the
The rotation of the oil pump 7 driven by the engine 3
When the speed is lower than the predetermined speed RA-HLD,
The line pressure rises slowly because the source pressure of the pump 7 is too low.
It is determined whether or not the state is such that this occurs. In addition, the input
The side rotation sensor 12 detects the rotation speed of the oil pump 7
And a rotation speed detecting means. Then, it is determined that the rotation speed is in the low rotation speed region.
If so, proceed to step 102, where the solenoid valve for shifting pressure control
9 is in hold to fix the control duty ratio
Is determined by the value of a hold flag described later. hold
If it is determined that the vehicle is not
It is determined whether there is a request for shift control. If it is determined that there is a downshift request
If so, proceed to step 104 and perform the downshift
Is larger than a predetermined amount. This
Here, when the shift width is larger than a predetermined amount, it will be described later.
Speed for performing line pressure increase control during downshift
The predetermined amount is set so as to satisfy a condition that is equal to or more than a predetermined value.
Under the condition that the line pressure increase control is performed.
Control to delay the decrease in the shifting pressure
I have. When the shift width of the downshift is large,
If it is determined, the process proceeds to step 105, where the hold
Set the value of lag to 1 and hold it, then step
Proceed to 108. The hold flag is set to 1
Is determined to be in hold in the determination of step 102
Proceeds to step 106 to determine whether a predetermined time has elapsed.
The process proceeds to step 108 until a predetermined time has elapsed.
Here, the predetermined time period is a line shift performed during a downshift.
This corresponds to the delay time of the increase in the pressure. At step 108, it is determined whether or not the hold is being performed.
Downshift system with a large shift width as described above.
Until the specified time elapses after your request,
Since the hold flag is set to 1, hold
It is determined to be medium and the process proceeds to step 109. In step 109
Means that the duty ratio of the solenoid valve 9 reduces the shift pressure
Duty ratio HLD-DTY is set. This de
The duty ratio HLD-DTY may be a preset value.
However, maintain the duty ratio just before the start of the downshift
The shift pressure may be changed according to a downshift request.
The duty ratio can be set to prevent the
No. Finally, proceeding to step 112,
The signal having the duty ratio set in 109 is
9 and is controlled so that the shift pressure does not decrease.
Until the predetermined time elapses, that is, as described later.
Line pressure rise system started with downshift request
Line pressure rise delay time
This state is maintained until the gear pressure rises,
Reduction is prevented. When the predetermined time has elapsed, step 104
Proceeds to step 107 by the determination of
Is reset to zero. As a result, the non-
It is determined that the hold is in progress, and the routine proceeds to step 110, where the target shift
The gear ratio is set, and in step 111, the gear ratio is set as the target gear ratio.
Thus, the duty ratio of the solenoid valve 9 is set. Soshi
To step 112, and
Duty ratio set by ratio feedback control
Is output to the solenoid valve 9 to set the gear ratio to the target
Feedback control is performed so as to match the gear ratio. In step 103, the downshift
If there is no request and even if there is a request,
If it is determined that the shift width of the gearshift is small,
Since the hold flag is not set to 1 at step 105
(The initial value has been reset to 0.)
From step 110 to the target gear ratio.
Lock control is performed. In this manner, when a downshift is requested,
Line pressure rise delay due to low oil pump discharge pressure
And the line pressure during this period is low,
Shift control, that is, control to reduce the shift pressure,
The gear pressure is too low and the gap between the primary pulley and the belt
If the line slips,
Prevents a reduction in shift pressure for a period corresponding to a delay in pressure rise
As a result, the slip is prevented and the durability of the belt is reduced.
Can be increased. Further, there is a possibility that belt slippage may occur.
The shift pressure is low for a predetermined period of time corresponding to the line pressure rise delay
After that, the speed changes at a speed corresponding to the target gear ratio.
Speed ensures good responsiveness and driving
Can be maintained well. FIG. 21 shows each of the components according to the present embodiment.
It shows the value. Step 101, step 104
Has a function to detect the condition where the line pressure rise delay occurs.
Construct line pressure rise delay detection means, and
Field flag is set, and
According to the judgment, it corresponds to the delay in the rise of the line pressure in step 109
The duty ratio of the solenoid valve 9 is fixed for a predetermined period
The function of delaying the shift pressure reduction control is the shift pressure reduction control delay.
Configure means. Next, the target executed in step 110
Set the gear ratio, that is, change the gear ratio to the actual target gear ratio.
Flowchart showing the feedback control routine shown in FIG.
It will be described according to. This routine is executed every unit time
Is done. In step 1, vehicle speed VSP and throttle opening
Based on the TVO, the final target gear ratio at steady state (maximum gear ratio)
Final target gear ratio, map gear ratio) A map that defines Base i
And read the Base i from the actual VSP and TVO.
Put in. In step 2, the output shaft rotation speed of the transmission
No is detected. This detection is performed by the vehicle speed sensor 12.
be able to. In step 3, the current gear ratio i is detected
I do. The gear ratio i is the engine speed (the input shaft of the transmission).
Rotation speed) N_EFrom the output shaft rotation speed No of the transmission,
These ratios (N_E/ N_O). In step 4, an engagement determined by the operation state
Calculate the number TTINR (short for target inertia torque)
Put out. This calculation method is based on one of the methods shown in FIGS.
Depends on the method. In the method of FIG. 5, first, at step 401,
The difference between the constant gear ratio Basei and the current gear ratio i (the absolute
Vs.) | Basei-i | or the ratio Basei / i (or
i / Basei) or the rate of change Δ of the gear ratio Basei in a steady state
Basei (absolute value of the amount of change per unit time
The absolute value of the difference from the calculated value). The ratio
When using, i / Basei and down
It may be Basei / i at the time of shifting. In step 402, if there is a difference,
In the case of the map of FIG. 8A and the ratio, the map of FIG.
In the case of the conversion rate, the coefficient TT is referred to with reference to the map of FIG.
Set the INR. However, the map is not
The characteristics are different at the time of the downshift. In the method of FIG.
First, at step 411, the engine speed N_EAnd su
Refer to the map from the throttle opening TVO and the engine
Luc TQ_ENGIs calculated, and in step 412, the engine
Luc TQ_ENGAnd engine speed N_EAnd from the current horse
POWER = TQ_ENG× N_EIs calculated. Then, at step 413, the output of the transmission
Shaft rotation speed N_OFrom the steady state gear ratio Basei,
Engine speed N_E’= N_OX Calculate Basei.
Then, at step 414, the steady-state engine speed
N_E’And the throttle opening TVO from the map (step
411)
Q TQ_ENG’. Then, in step 415,
Steady engine torque TQ_ENG’And steady-state engine
Rotation speed N_E”, The steady-state horsepower POWER ′ = T
Q_ENG’× N_E’. Then, at step 416, the horsepower at the steady state
The difference between POWER 'and the current horsepower (the absolute
Value) | POWER'-POWER | or ratio POWER
R '/ POWER (or POWER / POWE
R ′) or the rate of change ΔP of horsepower POWER ′ in a steady state
OWER '(the absolute value of the amount of change per unit time
(The absolute value of the difference from the value calculated in the routine of (1)). In step 417, if there is a difference,
In the case of the map of FIG. 8A and the ratio, the map of FIG.
In the case of the conversion rate, the coefficient TT is referred to with reference to the map of FIG.
Set the INR. In the method of FIG.
, The engine speed N_EAnd the throttle opening TVO
Engine torque TQ with reference to the map_ENGCalculate
Then, at step 422, the engine torque TQ_ENGAnd the present
Speed ratio i and a predetermined constant (including tire radius and differential characteristics)
Constant) K and the current vehicle driving force F = TQ_ENG× i
× K is calculated. Then, in step 423, the output of the transmission
Shaft rotation speed N_OFrom the steady state gear ratio Basei,
Engine speed N_E’= N_OX Calculate Basei.
Then, at step 424, the steady-state engine speed
N_E’And the throttle opening TVO from the map (step
Engine torque at steady state with reference to
Q TQ_ENG’. Then, in step 425,
Steady engine torque TQ_ENG’And steady state gear ratio Ba
From se i and a predetermined constant K, the driving force F ′ of the vehicle in a steady state
= TQ_ENG'× Base i × K is calculated. Then, at step 426, the vehicle in the stationary state
Difference between the driving force F 'of the vehicle and the driving force F of the current vehicle (the absolute value thereof).
Value) | F'-F | or the ratio F '/ F (or F /
F ′) or the change rate Δ of the driving force F ′ of the vehicle in a steady state.
F '(absolute value of the amount of change per unit time,
The absolute value of the difference from the calculated value for the chin) is calculated. And
In step 427, if there is a difference, the map shown in FIG.
In the case of, the map of FIG. 8B is used, and in the case of the change rate, the map of FIG.
The coefficient TTINR is set with reference to the map shown in FIG. Returning to FIG. 4, the description will be continued. Step 5
Then, the current gear ratio i, the transmission output shaft rotation speed N_O,
And from the coefficient TTINR, according to the following equation:
Is set to increase or decrease SV. SV = TTINR / (I_E× i × N_O) Where I_EIs a constant corresponding to engine inertia. In the present embodiment, as will be described later,
To reliably prevent the belt 6 from slipping during a speed transition
To optimize the line pressure control according to the shift speed SV
However, the shift transient in this line pressure control
In some cases, even if the line pressure is
The speed is very fast so that
In order to eliminate the possibility that the speed
In step 6, the subroutine shown in FIG.
Chin is supposed to run. That is, in step 601, whether the downshift is
Determine whether or not. For example, the final target speed ratio Basei and the speed change
By comparing the ratio i (at the start of the routine).
Can be. If YES, proceed to step 602, N
If it is O, this flow ends. In step 602,
Gear ratio Basei on the top and the currently set gear ratio (target gear ratio)
Ratio) Nexti is compared. These differences (or ratios)
Is greater than or equal to DWNPL, proceed to step 603,
If it is smaller than NPL, the shift process proceeds (near target gear ratio).
The shifting speed is set to be relatively slow (because it is done)
Because it is considered that the slip of the belt 6 hardly occurs,
This flow ends. In step 603, as shown in the flow
Referring to the map, the engine torque TQ_ENGOn the basis of the
The limit value SFTLMT of the set shift speed SV is determined.
I will. In step 604, the current SV and the limit value S
Compare with FTLMT. If SV ≧ SFTLMT
If SV = SFTLMT, the flow is terminated.
You. On the other hand, if SV <SFTLMT, SV
= SV, and the flow ends. like this
The speed change speed SV is set according to the engine torque.
Below a predetermined value SFTLMT (depending on the slipperiness of the belt 6).
At the time of shifting,
Even if the line pressure is increased more than a predetermined value, the belt 6 slips.
This eliminates the situation where shifting speeds are extremely high,
Thus, the slip of the belt 6 can be reliably prevented. This
Now, the description returns to the flowchart of FIG. In step 6, the current set speed ratio (target
Speed ratio) Nexti and the final target speed ratio at steady state (final
(I.e., target gear ratio) Basei to determine a magnitude relationship.
If Nexti> Basei, an upshift request (speed ratio reduction
(Small request), and proceed to step 7. In step 7,
Increase the set speed ratio (target speed ratio) Nexti with respect to the current value.
The decrement SV is reduced (see the following equation). Nexti = Nexti-SV If Nexti <Basei, a downshift request (increase in gear ratio)
Large request), and proceed to Step 8. In Step 8,
Increase the set speed ratio (target speed ratio) Nexti with respect to the current value.
The decrement SV is increased (see the following equation). Nexti = Nexti + SV In this way, the set speed ratio (target speed ratio) Nexti is set.
Then, the process proceeds to step 9. In step 9, change the settings.
Feedback so that the speed ratio (target gear ratio) Nexti can be obtained.
Lock control is performed. That is, the engine speed N_EAnd strange
Output shaft rotation speed N_OAnd the ratio (N_E/ N_OAs)
The detected current gear ratio i becomes the set gear ratio Nexti.
Gear ratio control is performed as described above. The speed ratio control detects the rotational speed ratio.
By increasing or decreasing the duty ratio of the solenoid valve 9
However, as described above, the predetermined change
In the speed condition, hold duty
And the line pressure rises after a predetermined time.
After that, the gear ratio control is started. this
As a result of such control, FIG. 10 shows the relationship between the low vehicle speed and the high vehicle speed.
As shown in the characteristics, even at the same speed ratio width, low vehicle speed and high vehicle speed
The shift speed changes with time, especially at high vehicle speeds.
Because the degree becomes slow, the inertia torque is roughly
The output can be kept constant during shifting
A decrease in torque can be avoided. FIG. 11 shows a method of calculating the coefficient TTINR.
Here is another example of the expression. In step 431, the slot
The rate of change of the opening degree ΔTVO (the absolute amount of change per unit time)
The detected value TVO in this routine and the overall
The absolute value of the difference from the detected value TVOold)
You. Then, in step 432, a map corresponding to FIG.
The throttle opening change rate ΔTVO
Then, the coefficient TTINR is set. The rate of change of the throttle opening ΔTV
Even if the coefficient TTINR corresponding to O is used,
Can be reflected. Note that the calculation method of the coefficient TTINR is as follows.
In addition to those listed in the above embodiment, the horsepower POWER
R, vehicle driving force F, engine speed N_EAnd slots
Opening TVO, intake air flow rate Q, or basic fuel injection amount
(Q / N_EFrom the equivalent value)
May be. By the way, in this embodiment, the controller
Reference numeral 11 denotes a line pressure control for performing the above-described shift control.
Control is achieved by executing the flowchart shown in FIG.
It has become. That is, block (1) [in the figure, simply
It is described as (1). The same applies hereinafter. ]
To the pulley-side actuator 4a (hydraulic chamber for gear ratio control)
The minimum pressure (Ppmin) of the supplied shift pressure is calculated. That is,
The belt 6 does not slip and must have a shift pressure that can achieve the target gear ratio.
Calculate the required minimum pressure (Ppmin). Specifically, the flowchart of FIG.
Is achieved by doing That is, at step 11,
Speed ratio (instruction speed ratio from the controller 11, etc.)
Required minimum shift pressure (Ppmin) suitable for engine torque
First, in order to obtain the speed ratio,
Required minimum primary pressure (shift pressure) magnification (θ₁/ Θ)
With the engine torque (or the input torque to the continuously variable transmission 3).
Pressure) and the required minimum primary pressure.
It is determined by referring to a set map or the like. In addition,
In the controller 11, the gear ratio is determined by the vehicle speed VSP and the speed.
A map in which the gear ratio is determined based on the throttle opening TVO
And set the gear ratio from the actual VSP and TVO
It is supposed to. Also, the desired engine operating state
To maintain the vehicle speed and achieve the driver's intended vehicle speed.
Alternatively, the gear ratio may be set. Take
In this case, keep the engine running with good fuel economy and exhaust performance.
To be advantageous in terms of fuel efficiency and exhaust performance.
Can be Then, in step 12, the primary minimum
The pressure (Ppmin) is determined according to the following equation. Primary minimum
Pressure (Ppmin) = engine torque x θ x magnification + offset
In the quantity block (2), the actuator on the secondary pulley side
Of the line pressure supplied to the heater 5a (hydraulic chamber for tension control)
Calculate the small pressure (Plmin). That is, the secondary pulley 5
The minimum pressure (Plmin) required to prevent the belt 6 from slipping on the side
Calculate. Specifically, the flowchart of FIG.
Is achieved by doing That is, in step 21,
Line pressure that matches the gear ratio and engine torque
To find the small pressure (Plmin),
Ratio of required minimum line pressure of gear ratio (θ₁/ Θ)
Jin torque TQ_ENG(Or the input torque to the continuously variable transmission 3)
And the required minimum line pressure.
It is determined by referring to a set map or the like. In step 22, the line minimum pressure (Plmin)
Is calculated according to the following equation. Line minimum pressure (Plmin) = engine torque x θ x magnification +
Offset amount In block (3), the actuator on the secondary pulley side
Calculation of the required thrust (FS) of the movable wall 5A of the
U. That is, the belt 6 slips on the primary pulley side.
Gear ratio (secondary pulley side effective diameter /
Primary pulley effective diameter = Primary pulley rotation speed /
Secondary pulley rotation speed, torque ratio)
In order to perform the
The thrust (pressing force) required for the movable wall 5A is obtained. What
The primary pulley side actuator 4a or
One of the pusher side actuators 5a
Once the force (in other words, hydraulic pressure) is determined, the belt tension and
From the relationship between gin torque and torque ratio, the thrust of the other
Can be determined logically. So here, the desired
The gear set by the solenoid valve 9 etc.
Imari minimum pressure (Ppmin) and primary pulley side movable wall 4
Determine the thrust FP on the primary pulley side 4a from the area of A, etc.
So, based on this,
In (3), a required secondary thrust (FS) is obtained. Soshi
And then, in block (4), the requested secondary thrust
(FS), the belt 6 on the primary pulley side
Necessary to achieve the desired gear ratio without slippage
To calculate the necessary pressure on the secondary pulley side
I have. More specifically, the request cell of block (3)
The kandari thrust (FS) is obtained by executing the flowchart in FIG.
It is requested by doing. In step 31,
The required secondary thrust (FS) is calculated based on the calculated secondary thrust. Requested secondary thrust (FS) = Primary minimum pressure (Ppmi
n) × area of primary pulley side movable wall 4A × coefficient 0−
Engine torque x coefficient 1 In block (4), the request security obtained in block (3)
Transmission ratio required line pressure based on the load thrust (FS)
(Plratio) is calculated. Specifically, the gear ratio required line pressure (Plrati
o) is obtained by executing the flowchart of FIG.
Can be That is, in step 41, the transformation is performed based on the following equation.
Calculate the required speed ratio line pressure (Plratio). Transmission ratio required line pressure (Plratio) = [request
Secondary thrust (FS)-secondary pulley spring constant x
Contraction length] / area of movable wall 5A The secondary pulley spring constant is the secondary pulley spring constant.
The movable wall 5A inside the rear-side actuator 5a is
The constant of the spring (not shown) for pushing back against the pressure
is there. In block (5), the basic line pressure (Pl b
ase). This means that the secondary
Line pressure (Plpr
s; this is described below) is the supply line pressure (basic
Line pressure) and the secondary pulley side actuator 5a
Oil trapped inside moves the movable wall 5A by centrifugal force
Centrifugal hydraulic pressure (Pscen; about this)
Will be described later), the secondary pulley spring force, and
Transient line to prevent belt 6 from slipping
Pressure (Pl add; line pressure increase control means at the time of rapid shifting according to the present invention)
Line pressure that is temporarily increased by
Calculate final line pressure because it is determined
As a basis, first calculate the basic line pressure (Pl base)
You. Specifically, the flowchart of FIG.
Is performed. In step 51, since the belt 6 does not slip
To achieve the minimum line pressure (Plmin) and the desired gear ratio
To the gear ratio required line pressure (Plratio) for
You. Line minimum pressure (Plmin) ≥ gear ratio required line pressure (Pl
ratio)), go to step 52. On the other hand,
Minimum pressure (Plmin) <gear ratio required line pressure (Plratio)
In the case of, the process proceeds to step 53. In step 52, the belt 6 is prevented from slipping.
To give priority, basic line pressure (Pl base) = line minimum pressure
(Plmin) and ends this flow. In step 53
Since there is room for slippage of the belt 6, the basic line
Pressure (Pl base) = Minimum pressure of gear ratio required line (Plratio)
 ), The flow ends. In block (6), the secondary centrifugal hydraulic pressure
(Pscen) is calculated. Specifically, the flow of FIG.
The chart is executed. In step 61,
To obtain the secondary centrifugal oil pressure (Pscen). Secondary centrifugal oil pressure (Pscen) = (Secondary pulley rotation
Rolling speed)^Two× coefficient In block (7), the belt 6 slips during a shift transition.
Calculate the transient line pressure (Pl add) to prevent the pressure change. That is, for example, the flowchart of FIG.
It is done by doing. In step 71, the downshift
Judge whether or not it is. For example, the final target gear ratio Basei and
It is determined by comparing the speed ratio i (at the start of the routine).
Can be If YES, proceed to step 72
If NO, the belt 6 can be used without performing the transient correction.
It is considered that the slip is unlikely to occur.
To set the transient line pressure (Pl add) to 0,
End the row. In step 72, the final target change on the map is performed.
The speed ratio Basei is compared with the current set speed ratio Nexti.
You. If these differences (or ratios) are more than DWNPL
If the value is smaller than DWNPL,
The gear shifting process progresses (because it is close to the target gear ratio)
Since the speed is set relatively slow, perform transient correction.
Without the belt 6 slipping
Then, the routine proceeds to step 75, where the transient line pressure (Pl add) = 0
To end the flow. In step 73, the current TQ_ENG, D
Engine rotation speed N_EFrom the throttle opening TVO
Calculate by referring to In step 74, during the flow
Refer to the map as shown to see the current engine torque.
Q TQ_ENGGear speed SV set based on
The transient line pressure (Pl add) is calculated. In other words, horizontal
Shaft; engine torque TQ_ENG, Vertical axis: transient line pressure
(Pl add) based on the constant speed change SV map
To find the transient line pressure (Pl add) at that time.
You. Thus, the transient line pressure (Pl add) is
The larger the torque, or the faster the shift speed SV,
A large value, in other words, the degree of slipperiness of the belt 6
The value is set according to the When the downshift is requested, the line pressure is set to the first
FIG.
The routine constitutes the line pressure increase control means. FIG.
Returning to block 2, in block (8), the final output line pressure
(Plprs) is calculated. That is, the basic obtained in (5)
Line pressure (Pl base) and secondary distance obtained in (6)
Cardiac hydraulic pressure (Pscen) and the transient lag obtained from block (7)
Based on the in-pressure (Pladd) and the secondary pulley spring force, etc.
Ask. Specifically, the flowchart of FIG.
Run. In step 81, the output line is calculated according to the following equation.
Find the pressure (Plprs). Output line pressure (Plprs) = [Basic line pressure (Pl base)
+ Transient line pressure (Pladd)-Secondary centrifugal oil pressure (Psc)
en)] x margin The margin includes the safety factor and the secondary
The pulley spring force and the like are also considered. In step 82, the output line pressure (Plprs
 ) And the limiter (LOW [lower limit] side). What
The limiter (LOW [lower limit] side) is set for each operating condition.
May be determined. Output line pressure (Plprs) <
If it is a mitter (LOW side), the process proceeds to step 83. Output line pressure (Plprs) ≧ limiter (LO
(W side), skip step 83 and proceed to step 8
Proceed to 4. In step 83, the output line pressure (Plprs)
= Set to limiter (LOW side). That is, the line pressure
To the minimum pressure (lower limit oil pressure) that the hydraulic circuit 8 can supply.
Set. As a result, the line pressure is maintained at a predetermined value.
To be set, for example, because the set hydraulic pressure is too low.
In-pressure cannot be maintained satisfactorily (for example, hunting
Line pressure control function
It is possible to eliminate problems such as the inability to perform the operation. Ma
In addition, it is also necessary to prevent the occurrence of control defects due to calculation errors, etc.
Becomes possible. In step 84, the output line pressure (Plprs
 ) And the limiter (HI [upper limit] side). What
Note that the limiter (HI side) should be set for each operating condition.
It may be. Output line pressure (Plprs) <limiter (H
I side), skip step 85 and repeat this flow.
finish. That is, in this case, the final output line pressure
(Plprs) is the result of the calculation in step 81.
Will be determined. On the other hand, output line pressure (Plprs) ≧ limiter
If (HI side), go to step 85. Step 8
In 5, output line pressure (Plprs) = limiter (HI side)
And the flow is terminated. In other words, the line pressure
To the maximum pressure that can be supplied by the hydraulic circuit 8 (upper limit oil pressure)
I do. This allows, for example, an excessive increase in belt tension.
Friction (if rotation becomes difficult) or
The pulley 6 and the secondary pulley actuator 5a
Or line pressure supply path breakage, excessive operation of oil pump, etc.
Can be reliably prevented. In addition, calculation errors
It is also possible to prevent the occurrence of control failure. The output line pressure thus obtained
(Plprs) is a flow control valve incorporated in the hydraulic circuit 8
When controlling via the output line pressure (Plprs)
Can be obtained through the solenoid valve 9 or the like,
The pressure acting on the valve body of the flow control valve due to switching of the path, etc.
To be adjusted by adjusting the opening.
Become. In other words, substantially the same control as the conventional shift pressure control is performed.
What should I do? As described above, the secondary pulley 5 and the bell
The minimum required line to prevent slippage from
Pressure (Plmin) while calculating the primary pulley 4
Gear ratio required to achieve target gear ratio without slippage on the side
Calculate the required line pressure (Plratio) and select one of these
Select the higher one and based on this selected line pressure,
Find the final output line pressure (Plprs) for the secondary
To supply the line pressure to the pulley-side actuator 5a
So that the drive side rotating member side and the driven
Does not relate to the side rotating member side, only one of them is considered
To prevent slippage of the power transmission member when
Can not achieve the gear ratio (torque ratio) of
The problem can be solved without fail,
Achieved target gear ratio without causing slip on the pulley pulley 4 side
In addition to the gear ratio control, the secondary pulley
Since it is performed on the side actuator 5a side,
All the controls are provided by the flow control valve for shifting control as in the past.
To greatly simplify the configuration when burdening
Can be. Further, according to the present embodiment, during the shift transition,
However, as the engine torque increases, or
The higher the speed, that is, the slip of the belt during shifting
Line pressure (Pl ad
d) to reduce belt slippage
To prevent belt slippage during shifting.
And without impairing the durability of the belt (excessive tension
No increase in rotational friction) and oil
Prevent deterioration of fuel efficiency etc. by suppressing unnecessary work of pumps
can do. In this embodiment, when adjusting the line pressure,
And through a flow control valve or the like incorporated in the hydraulic circuit 8
As described above, the line pressure control
Complex configuration for gear ratio control such as the Mari pulley side
Since it is not necessary to provide, the solenoid valve 10 is omitted and
Instead of a flow control valve, a pressure control that can directly control oil pressure
A control valve, for example, a duty control valve (open / close periodically and open
Pressure adjustment by changing the closing time ratio (duty ratio)
A possible valve), a duty signal from the controller 11
Drive to control the line pressure.
You may. This further simplifies the configuration and improves the accuracy.
Accuracy can be improved. Next, a second embodiment will be described. Book
In the embodiment, as shown in FIG.
All hydraulic sensors 21 to the secondary pulley side actuator
To the line pressure output passage 22 connecting the motor 5a and the hydraulic circuit 8.
Provided when the controller 11 requests the downshift.
Detected by the hydraulic pressure sensor 21 at the time of detection of a predetermined gear shifting condition.
To prevent the gear pressure from dropping until the input line pressure reaches a specified value.
Control so that The main routine including the shift pressure control is as follows:
As shown in FIG. 22, the first embodiment shown in FIG.
The difference from the main routine is that step 106 '
Instead of determining the shift pressure reduction prevention period at a fixed time,
The line pressure detected by the hydraulic pressure sensor 21 is compared with a predetermined value.
To prevent the reduction of the shift pressure until the predetermined value is reached.
I am trying to. In this embodiment, the actual line pressure is not detected.
Only the minimum necessary period according to the delay in line pressure rise
It is only necessary to prevent the reduction of the shifting pressure, thus preventing the belt from slipping.
Shift to target gear ratio while stopping and maintaining durability improvement effect
Start control as quickly as possible to ensure good responsiveness.
Can be. Also, according to the present invention, the line pressure control and the speed change
Regarding pressure control, in the above embodiment, the power source is an engine
Although described, the present invention can be applied to a case where another power source is used.
In addition to vehicles, for example, stationary, industrial, and machine tools
Extract power of arbitrary rotation speed from power source in machine etc.
The present invention can be applied to such cases. [0081] As described above, according to the first aspect,
According to the present invention, the shift pressure is low during the line pressure rise delay period.
The rotating part on the side controlled by the shifting pressure by blocking the lower part
Material and the power transmission member are prevented from slipping, reducing the durability.
It is a period that can be prevented and corresponds to a delay in line pressure rise
Since the control for lowering the gear shifting pressure can be delayed,
Can be minimized. According to the second aspect of the present invention, the transmission
Line pressure only when the speed change speed
Can be detected as a sudden shift condition that increases
There is no need to perform unnecessary line pressure increase control. In addition,
According to the invention as set forth in claim 3, the oil pressure which is the source pressure of the line pressure is used.
Line pressure rise delay condition when the discharge pump pressure is low
And delays the shift pressure reduction control only when necessary.
Can be According to the invention of claim 4, the license is
Control to reduce the shift pressure only until the gear pressure reaches the specified value.
Delay time should be kept to the minimum necessary
Can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing a configuration of the present invention. FIG. 2 is a system diagram showing one embodiment of the present invention. FIG. 3 is a flowchart of a main routine of control according to the embodiment. FIG. 4 is a flowchart of a shift control subroutine of the embodiment. FIG. 5 is a flowchart of a coefficient calculation subroutine (1). FIG. 6 is a flowchart of a coefficient calculation subroutine (2). FIG. 7 is a flowchart of a coefficient calculation subroutine (3). FIG. 8 is a diagram showing a coefficient calculation map. 9 is a flowchart of a subroutine for setting a shift speed limit value. FIG. 10 is a diagram showing characteristics of the embodiment. FIG. 11 is a flowchart of a coefficient calculation subroutine (4). FIG. 12 is a line of the embodiment. 5 is a flowchart illustrating pressure setting control. FIG. 13 is a flowchart illustrating block (1). FIG. 14 is a flowchart illustrating a block (2). FIG. 15 is a flowchart illustrating a block (3). FIG. 16 is a flowchart illustrating block (4). FIG. 17 is a flowchart illustrating a block (5). FIG. 18 is a flowchart illustrating a block (6). FIG. 19 is a flowchart illustrating block (7). FIG. 20 is a flowchart illustrating block (8). FIG. 21 is a time chart illustrating changes in respective values of the example. FIG. 22 is a system diagram of a second embodiment of the present invention. FIG. 23 is a flowchart of a main routine of control according to the embodiment. FIG. 24 is a time chart showing a change in each value in the conventional example. [Description of Signs] 1 engine 3 continuously variable transmission 4 primary pulley 4a primary pulley side actuator 5 secondary pulley 5a secondary pulley side actuator 6 belt 7 oil pump 8 hydraulic circuit 9 solenoid valve 10 solenoid valve 11 controller 12 input side rotation sensor 13 Output side rotation sensor 14 Throttle sensor 21 Oil pressure sensor

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 61/08 F16H 9/00

Claims (1)

(57) [Claim 1] A driving-side rotating member, a driven-side rotating member,
A power transmission member interposed between them to transmit power between the two, controlling the contact surface pressure between one of the rotation members and the power transmission member as a line pressure, and the other of the rotation member and the power transmission member By controlling the contact surface pressure with the line pressure as a transmission pressure adjusted in accordance with the target transmission ratio, the ratio of the radius from the rotation center of each rotating member to the contact point with the power transmission member can be steplessly adjusted. A control device for a continuously variable transmission that changes the speed ratio in a stepless manner by changing the speed ratio, wherein a sudden speed change condition detecting unit that detects a condition of a sudden speed change in a direction of decreasing the speed change pressure; A line pressure increase control means for increasing the line pressure for a predetermined period when a rapid shift condition is detected; and a condition in which a delay in increasing the line pressure occurs after the start of the line pressure increase control by the line pressure increase control means. To And the line pressure rises late condition detecting means for output, when a condition that increases the delay of the line pressure is generated is detected by the line pressure rise delay condition detection means, waiting for a period corresponding to an increase delay of the line pressure , The line pressure
Is adjusted in accordance with the target gear ratio to increase the gear shift pressure.
A control device for a continuously variable transmission, comprising: a shift pressure decrease control delay unit that starts control in a decreasing direction .