JPH0972397A - Belt type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve responsiveness through reduction of incurring of a friction loss by preventing the occurrence of the slip of a belt by deciding drive pulley thrust and driven pulley thrust based on a pulley thrust ratio, a target thrust, and a numbers of revolutions difference. SOLUTION: In a control means 60, when an input torque generating means 63 computes input torque TIN fed to a drive pulley and outputs it, a target thrust setting means 65 sets a target thrust FL based on the input torque TIN and an actual change gear ratio RAT. A pulley thrust ratio deciding means 69 decides a pulley thrust ratio RFR balancing with an actual change gear ratio based on the actual change gear ratio RAT. Meanwhile, a difference computing means 62 computes a number of revolutions difference between the target number NEO of revolutions of an engine and the actual number NE of revolutions of an engine and outputs it to a pulley thrust deciding means 66. The pulley thrust deciding means 66 decides drive pulley thrust FDR and driven pulley thrust FDN based on a pulley thrust ratio RFR, target thrust FL, and the number of revolutions deviation. This constitution generates optimum drive pulley thrust FDR and driven pulley thrust FDN, which correspond to a change speed ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt type continuously variable transmission which controls a driving pulley and a driven pulley independently to prevent belt slippage by an optimum pulley thrust corresponding to a running state of a vehicle or an engine braking state. .

[0002]

2. Description of the Related Art A conventional belt type continuously variable transmission is disclosed in Japanese Patent Laid-Open No.
As disclosed in Japanese Unexamined Patent Publication No. 1-218860, a first oil chamber in which a hydraulic pressure corresponding to an input torque or a torque ratio is constantly applied is provided in each of a driving pulley and a driven pulley, and the driving pulley and the driven pulley are suitable. It is configured to secure a belt clamping force having a large torque capacity.

A second oil chamber that acts on each of the movable sheaves of the drive pulley and the driven pulley is provided to supply or discharge the hydraulic pressure according to the speed change state and the positive / negative torque transmission state. A large axial force can be applied to the drive pulley or the driven pulley, and reliable power transmission without belt slip is possible.

Since the drive pulley and the driven pulley are hydraulically controlled by linear solenoids and the like respectively provided independently of each other, the shift control with a large degree of freedom is possible.

[0005]

In the conventional belt type continuously variable transmission, since the first oil chamber and the second oil chamber are provided in both the drive pulley and the driven pulley, the oil chamber structure of the drive pulley and the driven pulley is reduced. There is a problem that it becomes complicated and causes an increase in cost. The present invention has been made to solve such a problem, and an object thereof is to provide a belt type continuously variable transmission that has a simple structure, does not slip on a belt, improves friction loss, and is excellent in responsiveness. Especially.

[0006]

In order to solve the above problems, the control means for a belt type continuously variable transmission according to the present invention comprises an input torque generating means for calculating and outputting an input torque supplied to a drive pulley, and an input. Target thrust setting means for setting the target thrust based on the torque and the actual gear ratio, pulley thrust ratio determining means for determining the pulley thrust ratio that balances the actual gear ratio based on the actual gear ratio, target engine speed and actual A deviation calculating means for calculating a rotation speed deviation from the engine speed and a pulley thrust determining means for determining a driving pulley thrust and a driven pulley thrust based on the pulley thrust ratio, the target thrust and the rotation speed deviation are provided. Characterize.

Further, the pulley thrust determining means of the belt type continuously variable transmission according to the present invention sets one of the drive pulley thrust and the driven pulley thrust as the target thrust and the other as the product of the target thrust and the pulley thrust ratio or The value corresponding to the ratio,
The present invention is characterized in that a pulley thrust calculation means for setting a value equal to or larger than the target thrust by the sum of the target engine speed and the value corresponding to the speed deviation of the actual engine speed is provided.

Further, the pulley thrust determining means of the belt type continuously variable transmission according to the present invention sets one of the drive pulley thrust and the driven pulley thrust as the target thrust, and the other of them as the product of the target thrust and the pulley thrust ratio or It is characterized in that it is provided with a pulley thrust calculation means that is inversely proportional to the deviation between the value corresponding to the ratio and the value corresponding to the rotation speed deviation between the target engine speed and the actual engine speed, and is set to a value equal to or higher than the target thrust. To do.

Further, the pulley thrust calculation means of the belt type continuously variable transmission according to the present invention uses the value corresponding to the product of the target thrust and the pulley thrust ratio as a reference when the pulley thrust ratio is equal to or greater than a predetermined value. When the thrust force ratio is below a predetermined value, a determination means is provided for determining with a value corresponding to the ratio of the target thrust force and the pulley thrust force ratio as a reference.

[0010]

The control means for the belt type continuously variable transmission according to the present invention sets the target thrust based on the input torque and the actual gear ratio, and the input torque generating means for calculating and outputting the input torque supplied to the drive pulley. Target thrust setting means, a pulley thrust ratio determining means for determining a pulley thrust ratio that balances the actual gear ratio based on the actual gear ratio, and a deviation for calculating a rotational speed deviation between the target engine speed and the actual engine speed. Since the calculation means and the pulley thrust determining means for determining the drive pulley thrust and the driven pulley thrust based on the pulley thrust ratio, the target thrust and the rotational speed deviation are provided, the drive pulley drive pulley of the drive pulley corresponding to the pulley thrust ratio. One of the thrust and the driven pulley thrust of the driven pulley is set to the target thrust that does not cause the belt to slip, and the other is driven. Was set to a value greater than the target thrust corresponding to the target engine speed can be driven, the optimum drive pulley thrust and driven pulley thrust corresponding to the transmission ratio can occur.

Further, the pulley thrust determining means of the belt type continuously variable transmission according to the present invention sets one of the drive pulley thrust and the driven pulley thrust as the target thrust, and the other of them as the product of the target thrust and the pulley thrust ratio or The value corresponding to the ratio,
Since the pulley thrust calculation means for setting the target engine speed and the value corresponding to the rotation speed deviation of the actual engine speed to a value greater than the target thrust is provided, the belt type continuously variable transmission always has the minimum fuel consumption. Can be driven to prevent the belt from slipping.

Further, the pulley thrust determining means of the belt type continuously variable transmission according to the present invention sets one of the drive pulley thrust and the driven pulley thrust as the target thrust and the other as the product of the target thrust and the pulley thrust ratio. Since it is equipped with pulley thrust calculation means that is inversely proportional to the deviation between the value corresponding to the ratio and the value corresponding to the deviation of the target engine speed from the actual engine speed, and is set to a value equal to or greater than the target thrust, the minimum It is possible to drive the belt type continuously variable transmission with the fuel consumption of and prevent the belt from slipping.

Further, the pulley thrust calculation means of the belt type continuously variable transmission according to the present invention uses the value corresponding to the product of the target thrust and the pulley thrust ratio as a reference when the pulley thrust ratio is equal to or greater than a predetermined value. When the thrust ratio is less than the predetermined value, the determination means for making a determination based on the value corresponding to the ratio of the target thrust and the pulley thrust ratio is provided, so that the shift control corresponding to the state of the vehicle can be performed.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram of a main part of a belt type continuously variable transmission according to the present invention. In FIG. 1, a belt type continuously variable transmission (CVT) 1 is arranged between a metal V-belt mechanism 4 arranged between an input shaft 2 and a counter shaft 3 and an input shaft 2 and a drive pulley 5. Planetary gear type forward / reverse switching mechanism 2 provided
0, and a starting clutch 26 arranged between the counter shaft 3 and the output member (differential mechanism 29).

A belt type continuously variable transmission (CVT) 1
Is a hydraulic pump 30, a pulley side pressure control valve 40, a shift control valve 50, a metal V-belt mechanism 4 and a starting clutch 2.
A plurality of oil passages 30a to 30e for supplying hydraulic pressure to
A control unit 60, etc., which performs a predetermined calculation, conversion, and processing based on a signal representing the state of the engine and signals from various sensors to generate a control signal, is provided. The belt type continuously variable transmission (CVT) 1 is used for a vehicle, and the input shaft 2 is connected to an output shaft of an engine (ENG) via a coupling mechanism CP and is transmitted to a differential mechanism 29. Power is transmitted to the left and right wheels (not shown).

The metal V-belt mechanism 4 is wound around the drive pulley 5 arranged on the input shaft 2, the driven pulley 8 arranged on the counter shaft 3, and the drive pulley 5 and the driven pulley 8. And a metal V-belt 7.

The drive pulley 5 is a fixed pulley half body 5A rotatably arranged on the input shaft 2, and the fixed pulley half body 5A.
A movable pulley half 5B that can move axially relative to A
Is provided. A drive side cylinder chamber 6 sealed by a cylinder wall 5a connected to the fixed pulley half body 5A is formed on the side of the movable pulley half body 5B, and is supplied to the drive side cylinder chamber 6 via an oil passage 30d. Hydraulically moves the movable pulley half 5
A pulley thrust that moves B in the axial direction is generated.

The driven pulley 8 comprises a fixed pulley half body 8A arranged on the counter shaft 3 and a movable pulley half body 8B which is movable relative to the fixed pulley half body 8A in the axial direction. A fixed pulley half 8A is provided on the side of the movable pulley half 8B.
A driven side cylinder chamber 9 sealed by a cylinder wall 8a coupled to the driven side cylinder chamber 9 is formed, and a pulley for moving the movable pulley half body 8A in the axial direction by the hydraulic pressure supplied to the driven side cylinder chamber 9 through an oil passage 30e. Thrust is generated.

In this way, the metal V-belt 7 is controlled by controlling the hydraulic pressure (pulley-side pressure control hydraulic pressure) supplied to the drive-side cylinder chamber 6 and the driven-side cylinder chamber 9 to a desired value.
You can set the pulley thrust without slipping on the
The pulley widths of the drive pulley 5 and the driven pulley 8 can be varied, and the winding radius of the metal V-belt 7 can be continuously changed to change the gear ratio steplessly (continuously).

The planetary gear type forward / reverse switching mechanism 20 includes a sun gear 21 connected to the input shaft 2, a carrier 22 connected to the fixed half pulley 5A, a ring gear 23 which can be fixedly held by a reverse brake 25, and a sun gear 21. And a forward gear clutch 24 capable of connecting the ring gear 23 with the ring gear 23.

When the forward clutch 24 is engaged, the sun gear 21, the carrier 22, and the ring gear 23 rotate integrally with the input shaft 2, and the drive pulley 5 is driven in the same direction as the input shaft 2 (forward direction). To be done. On the other hand, reverse brake 2
When 5 is engaged, the ring gear 23 is driven in the direction opposite to the sun gear 21, and the drive pulley 5 is driven in the direction opposite to the input shaft 2 (reverse direction).

The starting clutch 26 controls the power transmission between the counter shaft 3 and the output side member, and when the clutch is engaged, the power transmission between the counter shaft 3 and the output side member becomes possible. When the starting clutch 26 is engaged, the engine output that has been shifted by the metal V-belt mechanism 4 is transmitted to the differential mechanism 29 via the gears 27a, 27b, 28a, 28b, and the differential mechanism 2
9 divides and transmits to the left and right wheels not shown.
When the starting clutch 26 is disengaged,
Since power is not transmitted, the belt type continuously variable transmission 1 is in a neutral state.

The operation control of the starting clutch 26 is performed by a signal supplied from the control means 60 to the clutch control valve 35, and the operating oil pressure is supplied from the clutch control valve 35 to the starting clutch 26 via the oil passages 30a and 30b. It is carried out by providing.

The pulley side pressure control valve 40 and the shift control valve 50 constitute a side pressure control valve, and supply hydraulic pressures are supplied to the drive side cylinder chamber 6 and the driven side cylinder chamber 9 based on a control signal supplied from the control means 60. (Pulley side hydraulic pressure) is controlled.

The shift control valve 50 is provided with two shift control valves for controlling the hydraulic pressure (pulley hydraulic pressure) to the drive side cylinder chamber 6 and the driven side cylinder chamber 9, respectively, and the valve adjustment is supplied from the control means 60. The linear solenoids provided in the two shift control valves are independently driven by the control signals (solenoid currents I _DR , I _DN ) that are set. The pulley thrusts of the drive pulley 5 and the driven pulley 8 are
It is represented by the product of the drive side pulley side pressure (P _DR ) supplied from the shift control valve 50 and the drive side cylinder area, and the product of the driven side pulley side pressure (P _DN ) and the driven side cylinder area, respectively.

The control means 60 is based on a microprocessor and has various arithmetic functions and memory functions, and controls the entire belt type continuously variable transmission 1 in accordance with an execution instruction software program. Further, the control means 60, a throttle opening signal (T _H) in which a plurality of sensors disposed in the belt type continuously variable transmission 1 has been detected, the vehicle speed signal (V), an engine speed signal (N _E), the drive pulley A target engine speed signal (N _EO ), a target pulley thrust signal (F _L ), an input torque signal (T) corresponding to the state of the vehicle based on the speed signal (N _DR ) and the driven pulley speed signal (N _DN ). _IN ), pulley thrust ratio (R
_FP ) etc. is generated from a data table which is calculated or preset in the memory, and the drive pulley thrust signal (F) is generated from these data.
_DR ), driven pulley thrust signal (F _DN ) and drive pulley thrust signal (F _DR ) and driven pulley thrust signal (F _DN ).
_Is converted into a control signal (solenoid current _IDR , _IDN ) and supplied to the linear solenoid of the shift control valve 50.

As described above, the belt type continuously variable transmission 1 according to the present invention is provided with the linear solenoid driven speed change control valve 50 for independently determining the pulley thrust of the drive pulley 5 and the pulley thrust of the driven pulley 8. Independent control is performed by a control signal (solenoid currents I _DR and I _DN ) from the control means 60 to prevent slippage of the metal V-belt 7 and obtain a desired gear ratio.

FIG. 2 is a block diagram of the shift control valve of the belt type continuously variable transmission according to the present invention. In FIG. 2, the shift control valve 50 includes a drive side shift control valve 51 and a driven side shift control valve 54.

The drive side shift control valve 51 and the driven side shift control valve 54 are respectively a linear solenoid 52,
The linear solenoid 55 is provided, the spool 53 and the spool 56 are driven by the solenoid drive currents I _DR and I _DN supplied from the control means 60 to adjust the valves, and the oil passages 30d and 3 are provided.
0e to drive the desired hydraulic pressure to the drive pulley 5 and the driven pulley 8
To provide.

The hydraulic pressures provided to the drive side cylinder chamber 6 and the driven side cylinder chamber 9 are the required movable pulley thrust force F _DR and driven pulley thrust force F _DN , respectively.
B, the driven pulley half body 8B is moved and suppressed by a clamping pressure that does not cause the metal V-belt 7 to slip, and the drive pulley 5
And the pulley width of the driven pulley 8 can be changed,
The desired gear ratio is set steplessly (continuously) by continuously changing the winding radius of the metal V-belt 7.

As described above, the shift control valve 50 of the belt type continuously variable transmission according to the present invention independently controls the linear solenoids 52 and 55 by the solenoid currents I _DR and I _DN supplied from the control means 60. Therefore, the desired driving pulley thrust force F _DR and the desired driven pulley thrust force F _DN can be supplied to the driving pulley 5 and the driven pulley 8.

FIG. 3 is a block diagram of the main control means of the belt type continuously variable transmission according to the present invention. In FIG.
The control means 60 is based on a microprocessor and is composed of various software control operation functions, memory, determination function, switch function, etc., and has a target engine rotation speed generation means 61, deviation calculation means 62, input torque generation means 63, pulley rotation. A ratio calculation means 64, a target thrust setting means 65, a pulley thrust determining means 66, and a pulley thrust ratio determining means 69 are provided.

The target engine speed generator 61 is a ROM.
The vehicle speed (V) -target engine speed (N _EO ) characteristic data having a throttle opening ( _TH ) as a parameter as shown in Table 1 of FIG. The target engine speed N _EO data corresponding to the signal V and the throttle opening signal T _H is read and the target engine speed signal N _EO is provided to the deviation calculation means 62.

The deviation calculating means 62 has a subtraction function, and the rotation speed of the target engine rotation speed signal N _EO provided from the target engine rotation speed generating means 61 and the engine rotation speed signal N _E supplied from the ECU shown in FIG. deviation calculating the outputs error signal (NE _O -N _E) in the pulley thrust determination means 66.

The input torque generating means 63 has a memory such as a ROM, and the engine speed (N _E ) with the throttle opening (T _H ) as a parameter as shown in Table 2 of FIG. 10 as a parameter.
-Input torque (T _IN ) characteristic data is set in advance, the input torque T _IN data corresponding to the throttle opening signal T _H and the engine speed signal N _E is read, and the input torque signal T _IN is set to the target thrust. Supply to the means 65.

The pulley rotation ratio calculation means 64 has a division function, and a pulley of the drive pulley rotation speed signal (N _DR ) detected on the drive pulley 5 side and the driven pulley rotation speed signal (N _DN ) detected on the driven pulley 8 side. Calculate the speed ratio (actual speed ratio),
The pulley rotation speed ratio (actual gear ratio) R _AT is set as the target thrust setting means 6
5

The target thrust setting means 65 is provided with a memory such as a ROM, and the pulley rotation speed ratio (R _AT ) with the input torque (T _IN ) as a parameter as shown in Table 3 of FIG.
Target thrust (F _L ) characteristic data is set in advance and corresponds to the input torque signal T _IN and the pulley rotation speed ratio R _AT , and the target thrust F that does not cause slippage on the metal V-belt 7 shown in FIG.
It reads _L data, and outputs a target thrust signal F _L on the pulley thrust determination means 66.

The pulley thrust determination means 66, the pulley thrust calculation means 67 comprises a solenoid current converter 68, the deviation signal from the deviation calculation unit 62 (N _EO -N _E), a target thrust signal from the target thrust setting unit 65 F _L and the pulley thrust ratio R drive pulley thrust based on the _FP F _DR from the pulley thrust ratio determining means 69 calculates the driven pulley thrust F _DN, drive pulley thrust F _DR and driven pulley thrust F _DN each driving solenoid current I _DR and the driven solenoid current I _DN are converted and supplied to the shift control valve 50 shown in FIG. 2 to drive and control the linear solenoids 52 and 55.

The pulley thrust ratio determining means 69 calculates a pulley thrust ratio R _FP that balances with the actual speed ratio R _AT based on the pulley speed ratio (actual speed ratio) R _AT supplied from the pulley speed ratio calculating means 64. Then, the pulley thrust ratio R _FP is provided to the pulley thrust determining means 66.

FIG. 4 shows a block diagram of the essential parts of the pulley thrust calculation means. In FIG. 4, pulley thrust calculation means 67
Are drive pulley thrust calculation means 81, driven pulley thrust calculation means 82, determination means 87, switching means 88, 90A, 90.
B, a drive pulley thrust output means 91, and a driven pulley thrust output means 92.

The drive pulley calculating means 81 is composed of various software-controlled calculating functions, and is provided with a drive side calculating means (B) 83 and a drive side calculating means (A) 84. The driving side computing means (A) 84 is composed of a multiplication function and a subtraction function, and is a product of the target thrust signal _FL and the pulley thrust ratio R _FP , a deviation signal (N _EO -N _E ).
After calculating the product x of the coefficient K and calculates the drive pulley thrust F _DR represented by the number 1, to provide a drive pulley thrust signal F _DR to the switching means 88 and the switching means 90A.

[0042]

[Number 1] _{F DR = F L × R FP} -x _{However, x = K × (N EO} -N E)

The driving side computing means (B) 83 has an addition function,
It has a subtraction function, a multiplication function, and a division function, calculates the drive pulley thrust force F _DR represented by z in Formula 2, and provides the drive pulley thrust signal F _DR to the switching means 90A.

[0044]

F _DR = z = (2-1 / R _FP ) × F _L + K × (N _EO −N _E ).

The driven pulley calculation means 82 is composed of various calculation functions of software control, and includes a driven side calculation means (A) 85 and a driven side calculation means (B) 86. The driven side computing means (A) 85 is composed of a division function and a subtraction function, and is a ratio of the target thrust signal _FL to the pulley thrust ratio R _FP and a deviation signal (N _EO −
After calculating the product x of N _E ) and the coefficient K, the driven pulley thrust force F _DN represented by the equation 3 is calculated, and the driven pulley thrust signal F _DN is provided to the switching means 88 and the switching means 90B.

[0046]

[Formula 3] F _DN = F _L / R _FP −x

The driven side computing means (B) 86 has an addition function,
It has a subtraction function and a multiplication function, and calculates the driven pulley thrust force F _DN represented by y in Equation 4 and provides the driven pulley thrust force signal F _DN to the switching means 90B.

[0048]

## EQU4 ## F _DN = y = (2-R _FP ) × FL + K × (N _EO −N _E ).

The judging means 87 has a soft control comparison function, and supplies a judgment signal H _T , for example, which has been coded, to the switching means 88 based on the input torque signal T _IN and the pulley thrust ratio R _FP , and drives the switching means 88. Side computing means (A) 84
Drive pulley thrust signal F _DR (= F _L × R _{FP provided by}
-X) or the driven pulley thrust signal F _DN (= F _L / R _FP -x) provided from the driven side computing means (A) 85 is selected.

For example, the input torque signal T _IN is positive (T _IN ≧
0) and the pulley thrust ratio R _FP is greater than 1 (R _FP ≧
1) and the input torque signal T _IN is negative (T _IN <0)
And the pulley thrust ratio R _FP is less than 1 (R _FP <1), the drive pulley thrust signal F _DR (= F _L × R _FP −x)
A decision signal H _T for selecting

On the other hand, the input torque signal T _IN is positive (T _IN ≧
0) and the pulley thrust ratio R _FP is less than 1 (R _FP <
1) and the input torque signal T _IN is negative (T _IN <0)
And the pulley thrust ratio R _FP is greater than 1 (R _FP ≧ 1)
In this case, the driven pulley thrust signal F _DN (= F _L / R _FP −
Provide a decision signal H _T to select x).

[0052] Switching means 88 is provided with a switching function of the soft control, the determination signal H drive pulley thrust signal on the basis of _{T F DR (= F L ×} R FP -x) supplied from the determining unit 87,
One of the driven pulley thrust signals F _DN (= F _L / R _FP −x) is selected and the selection signal S _O is supplied to the comparison means 89.

The comparison means 89 has a soft control comparison function, compares the selection signal S _O supplied from the switching means 88 with the target thrust signal _FL, and compares the comparison result with, for example, an encoded comparison signal H _O. Is output to control switching of the switching means 90A and the switching means 90B.

The switching means 90A has a software-controlled three-contact type switch function, and a comparison signal H from the comparison means 89.
There are three types of drive pulley thrust signals F _DR based on _O ,
Target thrust signal _FL , (F _L × R _FP -x) signal from driving side computing means (B) 84 represented by equation 1, z from driving side computing means (A) 83 represented by equation 2 One of the signals is selected, and the selection signal K _S is sent to the drive pulley thrust output means 91.
To supply.

The switching means 90B has a software-controlled three-contact type switch function, and a comparison signal H from the comparison means 89.
There are three types of driven pulley thrust signals F _DN based on _O ,
Y from the target thrust signal F _L, driven computing means represented by the number 3 (A) from _{85 (F L / R FP -x} ) signal, driven computing means represented by the number 4 (B) 86 One of the signals is selected, and the selection signal J _S is sent to the driven pulley thrust output means 92.
To supply.

For example, when the selection signal S _O is the drive pulley thrust signal F _DR (= F _L × R _FP −x), (F _L × R _FP −x)
And F _{L compare, (F L × R FP -x} ) is switching means when more than F _L 90A is a driving pulley thrust signal F _DR (= F _L
XR _FP- x) and the switching means 90B is configured to select the driven pulley thrust signal F _DN (F _L ). on the other hand,
When (F _L × R _FP −x) is less than or equal to F _L, switching means 90A
Selects the drive pulley thrust signal F _DR (= _FL ) and the switching means 90B selects the driven pulley thrust signal F _DN (= y).

Further, for example, when the selection signal S _O is the driven pulley thrust signal F _DN (= F _L / R _FP -x), (F _L / R _FP
-X) is compared with _{F L, (F L / R} FP -x) is switching means when more than F _L 90B are driven pulley thrust signal F
Select _{DN (= F L / R FP} -x), the switching means 90A is configured to select the drive pulley thrust signal F _DR (= F _L). On the other _{hand, (F L / R FP -x} ) is F switching means 90B when _L below selects the driven pulley thrust signal F _DN (= F _L), the switching means 90A is driven pulley thrust signal F _DR (= z)
To select.

The drive pulley thrust output means 91 and the driven pulley thrust output means 92 each have a buffer, and the drive pulley thrust signal F _DR corresponding to the selection signal K _S from the switching means 90A and the selection signal J _S from the switching means 90B. The driven pulley thrust signal F _{DN is provided} to the pulley thrust storage means 93 and the solenoid current conversion means 68 shown in FIG.

[0059] deviation signal of the pulley thrust calculation means according to the present invention in FIG. 5 (N _EO -N _E) - shows the thrust signal characteristic diagram. The characteristic of FIG. 5 represents the relationship between the drive pulley thrust F _DR and the driven pulley thrust F _DN with respect to the deviation (N _EO −N _E ) between the target engine speed N _EO and the engine speed N _E. Incidentally, the characteristic diagram is a driving pulley thrust F _DR is _{(F L × R FP -x)} , (F L
× R _FP -x) indicates the setting of the target thrust drive pulley thrust when F larger or against _L, or _at smaller F _DR and driven pulley thrust F _DN.

When (F _L × R _FP −x) exceeds the target thrust force F _L , the driven pulley thrust force F _DN is set to the target thrust force F _L (F _DN
= F _L ), and the drive pulley thrust F _DR is (F _L × R _FP −
x), and the deviation of x {= K × (N _EO −N _E )} (N
Decrease in the slope of the straight line -K in response to the increase in _EO -N _E).

[0061] When the deviation (N _EO -N _E) is zero, the drive pulley thrust F _DR takes a value (F _L × R _FP), the deviation (N _EO -
N _E ) decreases with increasing positive value and the deviation (N _EO)
-N _E ) is a predetermined value and the drive pulley thrust F _DR is the target thrust F
_L (F _DR = F _L ).

[0062] When deviation (N _EO -N _E) increases beyond a predetermined value, and sets (F _DR = F _L) to the target force F _L of the drive pulley thrust F _DR, the number of the driven pulley thrust F _DN Y {= (2-R _FP ) × F _L + K × (N _EO −
N _E )} value.

[0063] The goal for this driven pulley thrust F _DN, a value exceeding the deviation drive pulley thrust F _DR of Figure 5 is set to the target thrust force _{F L (F DR = F L} ) (N EO -N E) thrust F _L and the deviation from the sum of (N _EO -N _E), the deviation drive pulley thrust when (N _EO -N _E) is _{0 F DR (= F L ×} R FP) and a driven pulley thrust F _DN (= F _L) deviation of _{(F L × R FP -F L} ) is set to a value obtained by subtracting (y).

Although not shown, (F _L / R _FP -x)
If There exceeding target force F _L, sets the drive pulley thrust F _DR the target force _{F L (F DR = F L} ), a driven pulley thrust F _RN is set to _{(F L / R FP -x)} , x { = K × (N _EO −
N _E )} deviation (N _EO −N _E ) corresponding to increasing slope −K
It decreases with the straight line.

[0065] When the deviation (N _EO -N _E) is zero, the driven pulley thrust F _RN takes the (F _L / R _FP) value, the deviation (N _EO -
N _E ) is a predetermined value and the driven pulley thrust F _RN is the target thrust F _L (F
_RN = F _L) to become.

When the deviation (N _EO -N _E ) increases beyond a predetermined value, the driven pulley thrust F _RN is set to the target thrust F _L (F _DN = F _L ) and the drive pulley thrust F _{DR is set} to a number. Z {= (2-1 / R _FP ) × F _L + K × (N _EO −
N _E )} value.

[0067] Thus, it can also be set to a value greater than constantly target force F _L of the drive pulley thrust F _DR and driven pulley thrust F _DN.

[0068] Figure 6 is the deviation signal of the pulley thrust calculation means according to the present invention (N _EO -N _E) - shows another embodiment of the characteristic diagram of the thrust signal. 6, if the (F _L × R _FP -x) exceeds the target force F _L, the deviation (N _EO -N _E) increases beyond a predetermined value, sets the drive pulley thrust F _DR the target force FL (F _D
R = _FL ) and set the driven pulley thrust force F _DN to the y value shown in equation 5.

[0069]

F _DN = y = F _L ² / {R _FP × F _L −K × (N _EO −N _E )}

[0070] The driven pulley thrust F _DN is with the driving pulley thrust F _DR exceeds the set the target force _{F L (F DR = F L} ) is the deviation (N _EO -N _E) value of Fig. 6, the number Drive pulley thrust force F _DR is set to target thrust force F _L by the relational expression of 6 (F _DR = F _L ).
And calculated.

[0071]

[6] _{F DR / F DN = {R} FP × F L -K × (N EO -N E)} / F L

Although not shown, (F _L / R _FP -x)
Beyond but the target force F _L, the deviation if the (N _EO -N _E) increases beyond a predetermined value, the driven pulley thrust F _DN the target force F _L
And the drive pulley thrust force F _DR is set to the z value shown in Formula 7.

[0073]

F _DR = z = F _L ² / {(F _L / R _FP ) −K × (N
_EO- N _E )}

Next, the operation of the control means will be described based on the operation flow chart. 7 and 8 show operation flow charts of the control means of the belt type continuously variable transmission according to the present invention. Figure 7
In reads sensor signals from various sensors _{(T H, V, N DR} , N DN, N E) at step S1. Step S
At 2, the target engine speed N _EO shown in Table 1 of FIG. 9 is generated from the throttle opening _TH and the vehicle speed V.

Subsequently, in steps S3 to S5, the pulley rotation speed ratio R _AT is calculated from the ratio between the drive pulley rotation speed N _D and the driven pulley rotation speed N _DN , and from the throttle T _H and the engine rotation speed N _E of FIG. Input torque T _IN shown in Table 2
From the input torque T _IN and the pulley rotation speed ratio R _AT
The target thrust force _FL setting shown in Table 3 of No. 1 is executed.

Next, in step S6, the input torque T _IN ≧ 0
Whether T _IN ≧ 0 is determined in step S7.
And pulley rotation speed ratio (actual speed ratio) R _AT to R _AT , T _IN <0
In the case of (during deceleration), the pulley rotation speed ratio (actual speed ratio) R _AT is set to (1 / R _AT ) in step S8, and the process proceeds to step S9.

In step S9, the pulley rotation speed ratio (actual gear ratio) R _AT in steps S7 and S8
The pulley thrust ratio R _FP shown in Table 4 of 2 is set.
Step S10 makes a determination whether or not the input torque T _IN ≧ 0 again in the case of T _IN ≧ 0 is to determine whether or not the pulley thrust ratio R _FP ≧ 1 proceeds to step S11. On the other hand, when the input torque T _IN <0 in step S10, the process proceeds to step S12, and it is determined whether or not the pulley thrust ratio R _FP ≧ 1.

If the pulley thrust ratio R _FP ≧ 1 in step S11, or if the pulley thrust ratio R _FP <1 in step 12, the process proceeds to step S20 (state A) and step S20.
11 and pulley thrust ratio R _FP <1, or step 1
If the pulley thrust ratio R _FP ≧ 1 in step 2, step S30
Transition to (state B).

State A and state B in the operation flow diagram of FIG.
The operation flow of is shown. The state A of step S20 is transferred to step S21, and the driving pulley thrust force F _{DR is set} to ( _FL × R
_FP- x), and drive pulley thrust F is set in step S22.
_{DR (F L × R FP -x} ) and to compare the target force F _L, F _DR
> F _L if set the drive pulley thrust F _DR to _{(F L × R FP -x)} , a driven pulley thrust F _DN proceeds to step S23
Setting the target force F _L.

[0080] Further, after setting the drive pulley thrust F _{D R} the target force F _L at F _DR ≦ F _L If step S24 in step S22, shown in Equation 4 the driven pulley thrust F _DN proceeds to step S25 Set to y value.

On the other hand, the state B of step S30 is transferred to step S31, and the driven pulley thrust force F _{DN is set} to (F _L / R _FP
-X), and in step S32 the driven pulley thrust F _DN
(F _L / R _FP -x) and to compare the target force F _L, F _DN>
F _L if the driven pulley thrust F _DN is set to _{(F L / R FP -x)} , the process proceeds to step S33 to set the drive pulley thrust F _DR the target force F _L.

[0082] Further, after setting the driven pulley thrust F _{D N} the target force F _L at F _DN ≦ F _L If step S34 in step S32, indicating the transition to the drive pulley thrust F _DR to the number 2 in the step S35 Set to z value.

In the operation flow chart of FIG. 8, the values of y and z may be replaced with the y value shown in equation 5 and the z value shown in equation 7, respectively.

[0084]

As described above, the control means of the belt type continuously variable transmission according to the present invention comprises the input torque generating means for calculating and outputting the input torque supplied to the drive pulley, the input torque and the actual gear ratio. A target thrust setting means for setting a target thrust based on the actual gear ratio, a pulley thrust ratio determining means for determining a pulley thrust ratio that balances the actual gear ratio based on the actual gear ratio, and a target engine speed and an actual engine speed. A deviation calculating means for calculating a rotation speed deviation and a pulley thrust determining means for determining a drive pulley thrust and a driven pulley thrust based on the pulley thrust ratio, a target thrust and a rotation speed deviation are provided, which correspond to the pulley thrust ratio. One of the drive pulley thrust of the drive pulley and the driven pulley thrust of the driven pulley is set to a target thrust that does not cause the belt to slip, and the other is driven. -Drive can be set to a value greater than the target thrust corresponding to the thrust ratio and target engine speed, and drive pulley thrust and driven pulley thrust corresponding to the gear ratio are generated to improve friction loss. be able to.

Further, the pulley thrust determining means of the belt type continuously variable transmission according to the present invention sets one of the drive pulley thrust and the driven pulley thrust as the target thrust, and the other one of the product of the target thrust and the pulley thrust ratio or The value corresponding to the ratio,
Equipped with a pulley thrust calculation means for setting the target engine speed and the value corresponding to the speed deviation of the actual engine speed to a value greater than or equal to the target thrust, the drive pulley thrust and the driven pulley are set so that fuel consumption is always minimized. Since the thrust can be set,
The responsiveness and the convergence can be improved.

Further, the pulley thrust determining means of the belt type continuously variable transmission according to the present invention sets one of the drive pulley thrust and the driven pulley thrust as the target thrust, and the other sets the product of the target thrust and the pulley thrust ratio or Inversely proportional to the difference between the value corresponding to the ratio and the value corresponding to the rotational speed deviation between the target engine speed and the actual engine speed, equipped with a pulley thrust calculation means for setting a value equal to or higher than the target thrust. Since the drive pulley thrust force and the driven pulley thrust force can be set so that the responsiveness and convergence can be improved.

Further, the pulley thrust calculating means of the belt type continuously variable transmission according to the present invention uses the value corresponding to the product of the target thrust and the pulley thrust ratio as a reference when the pulley thrust ratio is equal to or greater than a predetermined value. When the thrust ratio falls below a predetermined value, a determination means is provided for making a determination based on the value corresponding to the ratio of the target thrust and the pulley thrust ratio, and the shift control corresponding to the vehicle condition is finely performed, so that friction loss and responsiveness are improved. Can be improved.

Therefore, it is possible to provide a belt type continuously variable transmission which has a simple structure, has little friction loss, and is excellent in responsiveness and convergence.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of essential parts of a belt type continuously variable transmission according to the present invention.

FIG. 2 is a configuration diagram of a shift control valve of a belt type continuously variable transmission according to the present invention.

FIG. 3 is a block diagram of the control means main part of the belt type continuously variable transmission according to the present invention.

FIG. 4 is a block diagram of a main part of a pulley thrust calculation means.

FIG. 5 is a deviation signal (N _EO -N _E ) -thrust signal characteristic diagram of the pulley thrust calculation means according to the present invention.

FIG. 6 is a characteristic diagram of another embodiment of the deviation signal (N _EO -N _E ) of the pulley thrust calculating means according to the present invention-thrust signal.

FIG. 7 is an operation flow chart of the control means of the belt type continuously variable transmission according to the present invention.

FIG. 8 is an operation flowchart of the control means of the belt type continuously variable transmission according to the present invention.

FIG. 9: Characteristic diagram of vehicle speed (V) -target engine speed (N _EO ) with throttle opening ( _TH ) as a parameter (Table 1)

FIG. 10 is a characteristic diagram of engine speed (N _E ) -input torque (T _IN ) using the throttle opening (T _H ) as a parameter (Table 2).

FIG. 11: Pulley rotational speed ratio (R _AT ) -Target thrust (F _L ) characteristic diagram with input torque (T _IN ) as parameter (Table 3)

FIG. 12: Pulley rotation speed ratio (1 / R _AT ) -pulley thrust ratio R _FP characteristic diagram (Table 4)

[Explanation of symbols]

1 ... Belt type continuously variable transmission, 2 ... Input shaft, 3 ... Counter shaft, 4 ... Metal belt mechanism, 5 ... Drive side movable pulley, 5
A, 8A ... Fixed pulley half body, 5B, 8B ... Movable pulley half body, 5a, 8a ... Cylinder wall, 6 ... Drive side cylinder chamber,
6a, 8a ... Cylinder wall, 7 ... V belt, 8 ... Driven side movable pulley, 9 ... Driven side cylinder chamber, 20 ... Planetary gear type forward / reverse switching mechanism, 21 ... Sun gear, 22 ... Carrier, 23
... Ring gear, 24 ... Forward clutch, 25 ... Reverse brake, 26 ... Start clutch, gears 27a, 27b, 2
8a, 28b ... Gear, 29 ... Differential mechanism,
30 ... Hydraulic pump, 30a-30e ... Oil passage, 35 ... Clutch control valve, 40 ... Pulley side pressure control means, 50 ... Shift control valve, 51 ... Drive side shift control valve, 52, 5
5 ... Linear solenoid, 53, 56 ... Spool, 54 ...
Driven side shift control valve, 60 ... Control means, 61 ... Target engine speed generating means, 62 ... Deviation calculating means, 63 ... Input torque generating means, 64 ... Pulley rotation ratio calculating means, 65
... Target thrust setting means, 66 ... Pulley thrust determining means, 67
... pulley pulley calculation means, 68 ... solenoid current conversion means, 69 ... pulley thrust ratio determination means, 81 ... drive pulley thrust calculation means, 82 ... driven pulley thrust calculation means, 83 ... drive side calculation means (B), 84 ... drive Side computing means (A), 8
5: driven side computing means (A), 86 ... driven side computing means (B), 87 ... determination means, 88, 90A, 90B ... switching means, 89 ... comparison means, 91 ... drive pulley thrust output means, 92 ... driven Pulley thrust output means.

Claims (4)

[Claims] 1. A gear ratio comprising control means capable of independently controlling a drive pulley thrust and a driven pulley thrust, and controlling the drive pulley thrust and the driven pulley thrust to achieve a target engine speed according to an operating state. In the belt-type continuously variable transmission for controlling, the control means sets the target thrust based on the input torque and the actual gear ratio, the input torque generating means calculating and outputting the input torque supplied to the drive pulley. Target thrust setting means, pulley thrust ratio determining means for determining a pulley thrust ratio that balances with the actual speed ratio based on the actual speed ratio, deviation for calculating a rotational speed deviation between the target engine speed and the actual engine speed A calculation means and a pulley thrust determiner for determining the drive pulley thrust and the driven pulley thrust based on the pulley thrust ratio, the target thrust and the rotational speed deviation. The belt type continuously variable transmission, characterized in that, with a. 2. The pulley thrust determining means sets one of a drive pulley thrust and a driven pulley thrust as a target thrust, and sets the other as a value corresponding to a product or ratio of the target thrust and the pulley thrust ratio, and a target engine rotation speed. 2. A belt type continuously variable transmission according to claim 1, further comprising a pulley thrust calculation means for setting a value equal to or larger than a target thrust by a sum of the number of rotations and a value corresponding to a rotation speed deviation of an actual engine rotation speed. . 3. The pulley thrust determining means sets one of a drive pulley thrust and a driven pulley thrust as a target thrust, and sets the other as a value corresponding to a product or a ratio of the target thrust and the pulley thrust ratio and a target engine rotation speed. 2. The belt type continuously variable belt according to claim 1, further comprising a pulley thrust calculation means for setting a value equal to or larger than a target thrust in inverse proportion to the deviation between the number of revolutions and the value corresponding to the deviation of the actual engine speed. transmission. 4. The pulley thrust calculation means uses a value corresponding to a product of a target thrust and a pulley thrust ratio as a reference when the pulley thrust ratio is a predetermined value or more, and when the pulley thrust ratio is less than a predetermined value. 4. The belt type continuously variable transmission according to claim 2, further comprising: a determination unit that determines the value based on a value corresponding to a ratio of the target thrust force and the pulley thrust force ratio.