JP3464347B2 - Transmission control device for continuously variable transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for a continuously variable transmission (hereinafter referred to as CVT), and is particularly suitable for use in, for example, a vehicle or the like for performing gear ratio feedback control using a hydraulic control valve. The present invention relates to a shift control device for a continuously variable transmission.

[0002]

2. Description of the Related Art Generally, for example, a belt type CVT for a vehicle.
Is a fixed pulley part, a movable pulley part, and a primary side pulley and a secondary side pulley having a hydraulic servo provided on the movable pulley part and having a continuously variable effective diameter. And a drive belt. Then, the oil pressure generated by the oil pressure source is adjusted to the oil pressure on the secondary side of the CVT (hereinafter, simply referred to as secondary side pressure) according to the transmission torque by the secondary side hydraulic control valve, and the hydraulic servo of the secondary side pulley is controlled. Supply. On the other hand, in order to change the winding radius of the drive belt and change the gear ratio, the secondary side pressure is adjusted by the primary side hydraulic control valve, and the hydraulic pressure on the primary side of the CVT (hereinafter simply (Referred to as the primary side pressure). Thus, the CVT continuously changes the rotation of the engine and transmits it to the wheels.

Here, the primary hydraulic control valve and the secondary hydraulic control valve are controlled by an electronic control unit. The electronic control unit inputs a vehicle speed, a throttle opening, etc., determines an appropriate target gear ratio according to the operating conditions of the vehicle, and feedback-controls the gear ratio of the CVT. In addition, in this way CV
A device for electronically controlling T is disclosed in, for example, JP-A-63-3032.
No. 58 publication.

[0004]

Generally, there are a flow rate control valve and a pressure control valve as an actuator for controlling the shift of a CVT. When the pressure control valve is used, the operation amount is the primary side pressure. Here, the oil pressure ratio P _R = primary side pressure P ₁ /
Assuming that the secondary side pressure P ₂ and the torque ratio T _R = input torque T ₁ / maximum transmission torque T _MAX , the hydraulic pressure ratio P _R in the steady state is expressed as a function of the gear ratio R and the torque ratio T _{R as in} the following equation. To be done.

P _R = f (R, T _R ) (1)

The speed ratio change speed dR / dt is proportional to the difference ΔP ₁ from each hydraulic pressure in the steady state expressed by the following equation.

ΔP ₁ = P ₁ −P ₂ · P _R (2)

When feedback control of the actual gear ratio R to the target gear ratio R _{S is performed} , in order to eliminate the deviation, a proportional gain is applied to the deviation, a so-called proportional calculation, or a deviation is multiplied by an integral gain to perform integration, a so-called integral calculation. Etc. are included.
In addition, a feedforward element may be combined in parallel with the feedback element in order to improve followability with respect to the target value.

By the way, since the torque ratio is deeply related to the shift control, a more appropriate torque ratio T _{R is} calculated in the shift control calculation.
It is known that the shift control performance can be improved by using. In calculating the torque ratio T _R , the normal input torque T ₁
Is used as

T ₁ = T _E -J ₁ (dN ₁ / dt) -T _ac (3)

Here, T _E is the engine output torque, J ₁ is the input side moment of inertia of the CVT, N ₁ is the CVT input side rotational speed, and T _ac is the torque consumed by the auxiliary machine. For example, in the case where the throttle is fully closed and decelerating to stop the vehicle, that is, when the target shift value at which the second term on the right side of the above equation (3) is substantially 0 is in the ab section of FIG. 13, The input torque T ₁ becomes equal to the engine output torque Te, but the engine torque in the engine braking state is generally inaccurate and changes depending on the operating state of the auxiliary machine. Furthermore, there are auxiliary machines such as air conditioners and compressors whose consumption torque is difficult to estimate, and the input torque is ambiguous in practice.

However, from the viewpoint of control calculation, the relationship of the above equation (1) is important. As shown in FIG. 14, this equation (1) has a small absolute value of the input torque, that is, an absolute value of the torque ratio. In a small place, the hydraulic pressure ratio P _R to the torque ratio
Has a high sensitivity, and a more accurate torque ratio, that is, an input torque is required for good control. In addition, as described above, when the absolute value of the input torque is small, that is, where the absolute value of the torque ratio is small, the above equation (3) is calculated to
Since the amount corresponding to the speed change ratio does not appear, it cannot be said to be optimum for the calculation of the speed change control. That is, in the case of the above example, the above equation (3) is an equation for calculating the CVT transmission torque, which is inaccurate as an absolute value and is not appropriate because it does not correspond to the shift speed as a relative value. There was the above problem.

As described above, when the torque ratio is used as a variable in the shift control calculation, it is important to calculate the torque ratio more appropriately. If the input torque is calculated as in the conventional case, the target There is a problem that the followability to the value may be poor.

The present invention has been made in order to solve the above problems, and in a feedback control system using a torque ratio as a variable of a shift control calculation, a feedback control system having a good followability with respect to a target value is provided. An object of the present invention is to provide a shift control device for a multi-speed transmission.

[0015]

Means for Solving the Problems] transmission control device for a continuously variable transmission according to the invention of this includes a rotating speed detecting means for detecting the respective rotation of the primary pulley and the secondary pulley, the rotational speed detection An actual speed ratio calculating means for calculating an actual speed ratio from the ratio of the rotational speeds from the means, a required load amount detecting means for detecting a load amount required for the engine, and at least an output of the required load amount detecting means and a load. Target speed ratio determining means for sequentially determining the target speed ratio based on the rotation speed of the gear, speed ratio control means for controlling the primary side hydraulic control valve so that the actual speed ratio matches the target speed ratio, The transmission torque calculation means for estimating the torque transmitted by the transmission, and the secondary side hydraulic control valve controlled according to the transmission torque estimated by the transmission torque calculation means, are required for the primary side pulley and the secondary side pulley. Generate a strong clamping force The transmission torque calculation means includes a secondary side pressure control means, and the transmission torque calculation means estimates the first transmission torque corresponding to the speed change ratio change speed associated with the speed change ratio of the continuously variable transmission; An input torque calculation unit that calculates a second transmission torque that is input to the continuously variable transmission, and a transmission torque determination unit that selects either the first transmission torque or the second transmission torque as the transmission torque are provided. And then
The transmission torque determining unit determines that the required load amount is smaller than a predetermined value.
If the engine is driven and the target changes
The speed ratio is increasing, or the engine is running and the above target is reached.
If the gear ratio is decreasing,
The larger of the 2nd transmission torque is the above-mentioned transmission torque.
Otherwise, the second transmission above
Luk is the transmission torque .

Furthermore, the shift control device for a continuously variable transmission according to this invention, the shift control unit has a feedforward control operation unit, the feed-forward control amount is a value corresponding to at least the transmitted torque It is a thing.

[0017]

Furthermore, the shift control device for a continuously variable transmission according to this invention includes a rotation speed detecting means for detecting the respective rotation of the primary pulley and secondary pulley, each from the rotational speed detecting means An actual speed ratio calculating means for calculating an actual speed ratio from the ratio of rotational speeds, a required load amount detecting means for detecting a load amount required for the engine, and at least an output of the required load amount detecting means and a rotational speed of the load. The target speed ratio determining means for sequentially determining the target speed ratio based on the above, the speed ratio control means for controlling the primary side hydraulic control valve so that the actual speed ratio matches the target speed ratio, and the continuously variable transmission are transmitted. And a transmission torque calculation means for estimating the torque to be controlled, and the secondary side hydraulic control valve is controlled in accordance with the transmission torque estimated by the transmission torque calculation means so that a clamping force required for the primary side pulley and the secondary side pulley is obtained. Secondary to generate A transmission torque calculating means for estimating a first transmission torque corresponding to a speed ratio change speed associated with a speed ratio change of the continuously variable transmission; An input torque calculation unit for calculating a third transmission torque input to the continuously variable transmission;
A transmission torque determining unit that selectively transmits torque to either the first transmission torque and the third transfer torque possess, the heat transfer
The reaching torque determining unit determines that the output torque of the fluid coupling is a predetermined value.
If it is smaller, and the engine is driven,
The target gear ratio is increasing, or the engine is running and
When the target gear ratio is decreasing, the first transmission torque is reduced.
Or the third transmission torque, whichever is greater,
It is determined as the reaching torque. In other cases, it is determined as the third torque above.
The transmission torque is used as the transmission torque .

Furthermore, the shift control device for a continuously variable transmission according to this invention, a value shift control means comprises a feed forward control computation unit, the feedforward control amount corresponds to at least the transmission torque To do.

[0020]

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention is applied to a belt type CVT for vehicles as an example.
It will be described in detail with reference to the drawings. Embodiment 1. 1 is a configuration diagram showing a first embodiment of the present invention. In the figure, reference numeral 1 denotes an engine (engine), the rotation of which is transmitted to a CVT 8 via an engine output shaft 2 and a clutch 3, and after continuously changing gears in the CVT 8, a differential device (not shown) is operated. It is adapted to be transmitted to a drive wheel (not shown) via the drive wheel. CVT
8 is a pair of input shaft 4 and output shaft 9 parallel to each other,
A pair of primary side pulleys 5 and secondary side pulleys 7 with variable effective diameters provided on the input shaft 4 and the output shaft 9, respectively, a drive belt 6 wound between these pulleys 5 and 7, and an input. Primary side hydraulic cylinders 5c and 2 provided on the shaft 4 and the output shaft 9, respectively, for applying a thrust force to the variable pulleys 5 and 7 in a direction to reduce the V groove width thereof.
A secondary hydraulic cylinder 7c is provided.

The pulleys 5 and 7 are fixed rotating bodies 5a and 7a fixed to the input shaft 4 and the output shaft 9, respectively.
And movable rotary members 5b and 7b which are provided on the input shaft 4 and the output shaft 9 such that they cannot rotate relative to each other and are movable in the axial direction. The pressure receiving area of the primary side hydraulic cylinder 5c is set to be larger than the pressure receiving area of the secondary side hydraulic cylinder 7c, and it functions as a hydraulic actuator that moves the movable rotating bodies 5b and 7b.
By changing the ratio of the radius of wrapping around the secondary pulley 7 and the secondary pulley 7, continuously variable speed is achieved.

Reference numeral 10 denotes a hydraulic pump, which is driven by the engine 1 and sends the hydraulic oil returned to the oil tank 15 through the oil passage 13 to the secondary hydraulic control valve 1.
1, pressure is fed to the primary side hydraulic control valve 12 and the secondary side hydraulic cylinder 7c. The secondary side hydraulic control valve 11 is usually a controller 20 that is configured by a microcomputer.
The hydraulic oil in the oil passage 13 is returned according to the signal S ₂ from the oil passage 1
6 to the secondary side pressure P which is the oil pressure of the oil passage 13.
Adjust pressure ₂ . If the oil pressure in the oil passage 14 is higher than the oil pressure corresponding to the signal S ₁ from the controller 20, the primary-side hydraulic control valve 12 causes the hydraulic oil in the oil passage 14 to flow out into the return oil passage 16 to reduce the pressure, and the signal S if lower than the hydraulic pressure corresponding to _1, by boosting allowed to flow into the hydraulic oil in the oil passage 13 to the oil passage 14, an oil pressure of the oil passage 14 in accordance with signal S ₁ 1 primary side pressure P ₁
Regulate the pressure.

The clutch 3 is, for example, an electromagnetic clutch, and changes its transmission torque from zero to a maximum value in accordance with a signal S _C from the controller 20, thereby disengaging the clutch, in a half-clutch (slip) state, and in a direct engagement state. Works in the state. The controller 20 includes an input port 20c, an output port 20d, an MPU 20a and a memory 20b which are connected to each other by a bus line 20e. Input of throttle opening detector 21 as required load amount detecting means for detecting throttle opening θ of throttle valve 22 in intake pipe 17 of engine 1, engine speed detector 18 for detecting engine speed Ne, and CVT 8. Each detection output of the CVT input shaft rotation speed detector 19 for detecting the rotation speed N ₁ of the shaft 4 and the CVT output shaft rotation speed detector 23 for detecting the rotation speed N ₂ of the output shaft 9 of the CVT 8 are input to the input port 20c. The controller 20 processes these input signals according to a program stored in the memory 20b in advance and supplied to the clutch 3 and the primary side hydraulic control valve 1.
2, to the secondary side hydraulic control valve 11, the respective signals S _C ,
The S _1, S ₂ is output from the output port 20d as the driving signal.

FIG. 2 is a functional block diagram showing an example of a concrete circuit configuration of the controller 20 shown in FIG. In the actual gear ratio calculating means 30, the ratio of the input rotation speed N ₁ from the CVT input shaft rotation speed detector 19 to the output rotation speed N ₂ from the CVT output shaft rotation speed detector 23, that is, CV
The gear ratio R (= N ₁ / N ₂ ) of T8 is calculated. In the first target gear ratio calculation means 31, the throttle opening θ from the throttle opening detector 21 (see FIG. 13) stored in advance,
The target primary-side rotation speed is obtained from the relationship with the output rotation speed N ₂ corresponding to the vehicle speed, and the steady-state gear ratio target value Rb, which is the value divided by the output rotation speed N ₂ at that time, is determined. A plurality of relationships shown in FIG. 13 are prepared and selected by the shift position S _R (for example, R, N, D, L, etc.) detected by the shift position detector 24 such as a shift lever (not shown).

In the operation mode determining means 32, the output rotational speed N ₂ corresponding to the vehicle speed and the vehicle acceleration A _{C of the} differential value thereof,
The output of the braking state detector 25, which detects the braking state of the vehicle from the brake signal and the vehicle acceleration A _C, and the throttle opening θ
Or its differential value, the shift position S _R, and the predetermined judgment values corresponding to these pieces of information, the vehicle operating state and the driver's will are estimated, and the target including the transient state is estimated. The operating condition (operating mode Mo) for determining the gear ratio (second target gear ratio) R _S and the secondary side pressure target value is, for example,
It determines which region (mode) of the stop mode, the start mode, the normal traveling mode, the sudden acceleration mode, the sudden deceleration mode, the downhill mode, and the slippery road mode.

In the second target gear ratio calculation means 35, when the first target gear ratio Rb changes, the second target gear ratio Rb is equal to or lower than the maximum speed ratio change speed predetermined from the actual gear ratio R and the operation mode Mo.
A second target gear ratio R _S (hereinafter simply referred to as a target gear ratio) that changes following the first target gear ratio Rb is calculated.

FIG. 3 is a functional block diagram showing an example of a concrete circuit configuration of the input torque calculation means 34 as the transmission torque calculation means. First, the shift torque calculation unit 341 calculates the transmission torque A (T _1A ) as the first transmission torque of the CVT by the following formula based on the output rotation speed N ₂ corresponding to the input vehicle speed and the target gear ratio R _S. To do.

T _1A = | K ⁻¹ J ₁ N ₂ (dR _S / dt) | (4)

Here, K = 1 + (R _S ) ² J ₁ / J ₂ (5). It should be noted that this transmission torque A is the same as the CVT due to the shift.
Is a torque (hereinafter, referred to as a gear shift transient torque) associated with the transfer of rotational energy between the input and output side inertia moments.

In the above equations (4) and (5), J ₁ is the total moment of inertia between the engine and the primary pulley, and J ₂ is the total moment of inertia connected to the CVT output side. It is a total value obtained by converting the inertia moment of the rotating portion and the equivalent moment of inertia corresponding to the mass of the vehicle body into the CVT output shaft. Further, in the input torque calculation unit 342, as shown in FIG.
Throttle opening θ and engine speed N
This engine output torque Te is obtained from the relationship between e and the engine output torque Te, and the CVT is calculated according to the following equation.
The transmission torque B (T _1B ) as the second transmission torque of is calculated.

T _1B = │Te-J ₁ (dNe / dt) │ (6)

This equation (6) substantially omits the torque T _ac consumed by the auxiliary machine of the above equation (3). Further, the CVT transmission torque A (T
_1A ) and the transmission torque B (T _1B ) are supplied, the transmission torque determining unit 343 performs the process according to the flowchart shown in FIG. 5 to determine the transmission torque T ₁ . That is, when the throttle opening θ is less than the predetermined value θ1 (No in step S1)
When the engine is in the driven state (Te <0: No in step S2) and the target gear ratio is increasing (dRs / d
t> 0: Yes in step S3), or when the engine is in a driving state (Te> 0: Yes in step S2) and the target gear ratio is decreasing (dRs / dt <0: step S
No. 4), transmission torque A (T _1A ) and transmission torque B (T 1
The larger of ( _1B ) is the transmission torque T ₁ (step S
5).

In other cases, the transmission torque B (T _1B ) is set as the transmission torque T ₁ . That is, when the throttle opening θ is larger than the predetermined value θ1 (Yes in step S1) or when the throttle opening θ is the predetermined value θ1 or less (No in step S1), the engine is in the driving state (Te> 0: When the target gear ratio is increasing (Yes in step S2) (dRs / dt> 0: Yes in step S4), or
The engine is in a driven state (Te> 0: N in step S2)
o) and the target gear ratio is decreasing (dRs / dt
<0: No in step S3), transmission torque B (T1 _B )
Is the transmission torque T ₁ (step S6).

The processing of the transmission torque determining unit 343 will be further described with reference to FIG. 6 which is an enlarged view of a portion of FIG. 14 where the absolute value of the torque ratio is small. Now T _1A > T
_The case of _1B is a case where the speed change ratio is large, and in this case, the white circle in FIG. 6 is the calculated value at T _1A and the black circle is the calculated value at T _1B . It should be noted that the right side and the left side centering on the hydraulic pressure ratio 0 in FIG. 6 show the case where the engine is in the driven state and the driven state, respectively. First, in the driving state, when it is desired to control the speed ratio to the OD (highest speed) side (decrease speed ratio), the higher hydraulic ratio should be selected, so the white circle b = T _1A is selected.
In the driven state, when it is desired to control the gear ratio to the FL (minimum speed) side (increased gear ratio), a lower value should be selected for the hydraulic ratio, so the white circle c = T _1A is selected. In other cases, it is obvious that it is better to select black circle = T _1B .

Now, returning to FIG. 2, the target secondary side pressure calculating means 37 calculates the target gear ratio R _S , the CVT input torque T ₁ , and
From the operation mode Mo, the target secondary side pressure P _2S required to control the shift to the target gear ratio R _S without the belt slipping of the CVT 8 is determined. The secondary side current calculation means 38 calculates and outputs the drive current I ₂ of the secondary side hydraulic control valve 11 from the current-hydraulic characteristic as shown in FIG. 7.

The target primary side pressure calculating means 40 calculates the primary side pressure necessary for shifting the CVT 8, that is, the target primary side pressure P _1S so that the actual gear ratio R matches the target gear ratio R _S. FIG. 8 is a functional block diagram showing an example of a specific circuit configuration of the target primary side pressure calculating means 40. In the figure, the pulley position calculation units 44 and 45 indicate the target gear ratio R
_{The S} and the actual gear ratio R are converted into the target pulley position X _S and the actual pulley position X, respectively. In the following description, the smaller the gear ratio, the larger the value indicating the pulley position.

The feedback control calculation unit 47 as the integral control calculation means includes an output pulley position deviation X of the adder 46.
_{For E} , control law calculation such as PID (proportional, integral,
Differential) control calculation is performed and P _1FB for feedback control is output. The torque ratio calculation unit 41 determines a torque ratio T _R defined as the ratio of the input torque T _{1 to} the torque T _MAX (function of the target gear ratio R _S ) that can be transmitted at the target secondary side pressure P _2S without belt slip. In the hydraulic pressure ratio calculation unit 42,
From the torque ratio T _R and the target gear ratio R _S obtained previously, the hydraulic pressure ratio P _R
(Primary side pressure / Secondary side pressure) is obtained from the predetermined relationship shown in FIG. Next, the feedforward control calculation unit 43 obtains the feedforward control amount P _1FF from the hydraulic pressure ratio P _R , the target secondary side pressure P _2S and the differential value of the target pulley position X _S = the target pulley moving speed V _PS by the following formula.

P _1FF = P _2S × P _R + K _V × V _PS (7)

In this equation (7), K _V is a predetermined value. With respect to the result of adding the feedback control component P _1FB and the feedforward control component P _1FF in the adder 48, the target primary side pressure limiting unit 49 _sets the target secondary side pressure as its upper limit value, and the input torque T ₁ and the actual speed change. From the ratio R, the lowest hydraulic pressure at which the belt does not slip on the primary side pulley is set as the lower limit value, and the value after being limited to a value between the lower limit value and the upper limit value is output as the target primary side pressure P _1S .

Now, returning to FIG. 2 again, in the primary side current control means 36, similarly to the secondary side current control means 38, the drive current I is determined from the predetermined relationship between hydraulic pressure and current (see FIG. 7).
₁ is determined and output to the primary hydraulic control valve 12. In addition,
The first target speed ratio calculation means 31, the second target speed ratio calculation means 35, and the operation mode determination means 32 constitute a target speed ratio determination means, and the target primary side pressure calculation means 40 and the primary side current control means 36 change speed. The target secondary side pressure calculation means 37 and the secondary side current control means 38 constitute a ratio control means, and a secondary side pressure control means.

FIG. 9 is a block diagram showing an example of a concrete circuit configuration of the feedback control calculation unit 47. In the figure, K _P , K _D , and K _I are proportional gain, differential gain, and integral gain, respectively, and Z ⁻¹ is an operator used in Z conversion, and the PID control calculation of this feedback control calculation unit 47 is The difference from the normal PID control calculation is the deviation X _E
Is divided by the target secondary side pressure P _2S , multiplied by an integration gain K _I and integrated, and the integrated value P _INT is multiplied by the target secondary side pressure P _2S and output.

As described above, in many cases, the above equation (3) is sufficient to secure a good followability with respect to the target value. However, in the present embodiment, the CVT transmission torque is changed to the normal input torque (transmission). A transmission torque calculating means for obtaining both the torque B) and the shift transient torque (transmission torque A) is provided, and when the absolute value of the engine torque is small, the CVT transmission torque is not calculated from the external force viewed from the CVT but the shift transient. By calculating the magnitude of the torque, the CVT that is highly accurate and corresponds to the shift speed can be obtained as a CVT suitable for the control purpose.
It is possible to obtain a transmission torque value and perform control with good followability with respect to the target value. That is, particularly when the engine output torque is small and the gear ratio is changed, the gear shift transient torque obtained from the target gear shift speed is adopted as the CVT transmission torque, and the control calculation is executed with a value corresponding to the gear shift speed. Therefore, control performance with good followability can be obtained.

Embodiment 2. FIG. 10 is a functional block diagram showing the second embodiment of the present invention. In the figure, FIG.
The same reference numerals are given to the portions corresponding to, and detailed description thereof will be omitted. In the first embodiment, the clutch 3 is used as the detection target of the CVT input shaft rotation speed detector 19 that detects the input rotation speed N _1. However, in the present embodiment, instead of this, a fluid coupling is used. This is the case of using the torque converter (not shown). The input torque calculation means 34A of the controller 20A in the present embodiment is
CVT input shaft rotation speed detector 19, CVT output shaft rotation speed detector 23, engine rotation speed detector 18 and second
The input torque of the CVT is determined based on the output of the target gear ratio calculation means 35, and other configurations are similar to those in the case of FIG.

FIG. 11 is a functional block diagram showing an example of a concrete circuit configuration of the input torque calculating means 34A as the transmission torque detecting means. In the figure, parts corresponding to those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted. The input torque calculation unit 344 calculates the transmission torque C (T _1C ) as the third transmission torque of the CVT according to the following equation.

T _1C = │T _T -J ₃ (dN ₁ / dt) │ (8)

Here, J ₃ is the total value of the moment of inertia between the turbine of the torque converter and the primary pulley, T
_T is the output torque of the torque converter, and the speed ratio e = N _E which is the input rotation speed and N ₁ which is the output rotation speed.
It is calculated by the following formula based on N ₁ / N _E.

T _T = K _T (e) · (N _E ) ² (9)

Here, K _T (e) is a unique value determined by the speed ratio e. The calculation relating to this equation (9) is also performed in the input torque calculation unit 344. Further, the CVT transmission torque A (T _1A ) and the transmission torque C calculated as described above.
The transmission torque determination unit 345 supplied with (T _1C ) performs the process according to the flowchart shown in FIG. 12 to determine the transmission torque T ₁ . That is, when the output torque T _T of the torque converter is less than or equal to the predetermined value T _TH (N in step S11)
o), the engine is in a driven state (Ne> N ₁ : step S)
No. 12) and when the target gear ratio is increasing (dR
s / dt> 0: Yes of step S13), and or, the engine drive state (Ne <N _1: When Yes) and the target speed ratio of the step S12 is reduced (dRs / dt <0:
The larger of the transmission torque A (T _1A ) and the transmission torque C (T _1C ) is set as the transmission torque T ₁ (No in step S14) (step S5).

In other cases, the transmission torque C (T _1C ) is set as the transmission torque T ₁ . That is, when the output torque T _T of the torque converter is larger than the predetermined value T _TH (step S
11) or the output torque T _T of the torque converter is less than or equal to a predetermined value T _TH (No in step S11)
Then, when the engine is in a driving state (Ne <N ₁ : Yes in step S12) and the target gear ratio is increasing (dRs / dt
> 0: Yes of step S14), and or, the engine is driven state (Ne> N _1: When No) and the target speed ratio of the step S12 is reduced (dRs / dt <0: No of step S13), and The transmission torque C (T _1C ) is set as the transmission torque T ₁ (step S16).

As described above, in the present embodiment, the transmission torque calculating means for obtaining the CVT transmission torque from both the normal input torque (transmission torque C) and the shift transient torque (transmission torque A) is provided, and the absolute value of the engine torque is calculated. If the value is small, the CVT transmission torque is not calculated from the external force viewed from the CVT, but the magnitude of the shift transient torque is calculated to obtain a high accuracy and a value corresponding to the shift speed.
It is possible to obtain a CVT transmission torque value suitable for the control purpose and perform control with good followability to the target value.

Embodiment 3. In the above embodiment, the case where the throttle opening θ is used to detect the required load of the engine has been described, but the present invention is not limited to this. For example, the operation amount of the accelerator pedal or the intake pipe of the engine may be used. It may be an amount such as negative pressure.

Fourth Embodiment Further, the hydraulic pressure ratio may be a final pulley pressing force ratio. Therefore, the present invention is not limited to the belt type continuously variable transmission as long as the transmission can be expressed as the ratio of the pressing force on the primary side to the pressing force on the secondary side. A toroidal type continuously variable transmission may be used.

Embodiment 5. Further, in the above embodiment, the case where the present invention is applied to the continuously variable transmission for the vehicle has been described, but the present invention is not limited to this, and other devices such as the continuously variable transmission for aircraft and ships, etc. Can be similarly applied to, and has the same effect.

[0055]

As it is evident from the foregoing description, according to this invention, a rotational speed detection means for detecting the respective rotation of the primary pulley and secondary pulley, each rotation speed from the rotation speed detecting means Based on at least the output of the required load amount detection means and the rotational speed of the load, the actual gear ratio calculation means for calculating the actual gear ratio from the ratio, the required load amount detection means for detecting the load amount required for the engine, The target transmission ratio determining means for sequentially determining the target transmission ratio, the transmission ratio control means for controlling the primary side hydraulic control valve so that the actual transmission ratio matches the target transmission ratio, and the torque transmitted by the continuously variable transmission are The transmission torque calculation means to be estimated, and the secondary side hydraulic control valve is controlled according to the transmission torque estimated by the transmission torque calculation means to generate a clamping force required for the primary side pulley and the secondary side pulley. Equipped with secondary pressure control means Transmission torque calculating means first corresponding to the gear ratio change rate due to the gear ratio change of the continuously variable transmission
Of the first transmission torque and the second transmission torque of the continuously variable transmission, which calculates the second transmission torque input to the continuously variable transmission from the engine output torque. possess a transmission torque determining section to transmit torque select one, the transmission torque determining section,
If the required load is smaller than the specified value and the engine
Drive is in a driven state and the target gear ratio is increasing, or
If the engine is running and the target gear ratio is decreasing,
Is the first transmission torque and the second transmission torque.
The one with the larger deviation is determined as the above transmission torque, and
In the case of the outside, since the second transmission torque is the transmission torque , the continuously variable transmission (CV
By incorporating the torque that will occur in T) into the calculation as a part of the CVT transmission torque, it is possible to more accurately estimate the torque ratio that governs the CVT transmission characteristics, and especially when the transmission torque is small. There is an effect that the followability with respect to the target value of control can be improved, there is no need to add new hardware, it can be realized only by program processing, and an inexpensive and high-performance CVT shift control device can be obtained. Furthermore, it is possible to execute the control calculation with the value corresponding to the shift speed.
And has the effect of obtaining control performance with good followability.
It

[0056] transmission control device for a continuously variable transmission according to this invention, the shift control unit has a feedforward control operation unit, the feed forward control amount, since a value corresponding to at least the transmitted torque, The feedforward control amount becomes a function of the transmission torque, and it becomes easy to correct the feedforward control amount by using the value corresponding to this transmission torque, and the variation of the shifting characteristics of the continuously variable transmission is improved. The effect is that you can do it.

[0057]

[0058] Further, the shift control device for a continuously variable transmission according to this invention includes a rotation speed detecting means for detecting the respective rotation of the primary pulley and secondary pulley, each from the rotational speed detecting means An actual speed ratio calculating means for calculating an actual speed ratio from the ratio of rotational speeds, a required load amount detecting means for detecting a load amount required for the engine, and at least an output of the required load amount detecting means and a rotational speed of the load. The target speed ratio determining means for sequentially determining the target speed ratio based on the above, the speed ratio control means for controlling the primary side hydraulic control valve so that the actual speed ratio matches the target speed ratio, and the continuously variable transmission are transmitted. And a transmission torque calculation means for estimating the torque to be controlled, and the secondary side hydraulic control valve is controlled in accordance with the transmission torque estimated by the transmission torque calculation means so that a clamping force required for the primary side pulley and the secondary side pulley is obtained. Secondary to generate A transmission torque calculating means for estimating a first transmission torque corresponding to a speed ratio change speed associated with a speed ratio change of the continuously variable transmission; An input torque calculation unit for calculating a third transmission torque input to the continuously variable transmission;
A transmission torque determining unit that selectively transmits torque to either the first transmission torque and the third transfer torque possess, the heat transfer
The reaching torque determining unit determines that the output torque of the fluid coupling is a predetermined value.
If it is smaller, and the engine is driven,
The target gear ratio is increasing, or the engine is running and
When the target gear ratio is decreasing, the first transmission torque is reduced.
Or the third transmission torque, whichever is greater,
It is determined as the reaching torque. In other cases, it is determined as the third torque above.
Since the transmission torque is the above transmission torque, the torque that would be generated in the fluid coupling of the continuously variable transmission (CVT) by the shift control operation is taken into the calculation as a part of the CVT transmission torque, so that the transmission of the CVT is changed. The torque ratio that governs the characteristics can be more accurately estimated, the followability to the target value of the CVT shift control can be improved particularly when the transmission torque is small, and there is no need to add new hardware.
Inexpensive and high-performance CVT that can be realized only by program processing
There is an effect that a shift control device can be obtained. Furthermore,
The control calculation can be executed with the value corresponding to the high speed, and the followability is good.
The effect is that good control performance can be obtained.

[0059] Further, the shift control device for a continuously variable transmission according to this invention, the shift control unit has a feedforward control operation unit, the feed-forward control amount is a value corresponding to at least the transmitted torque Therefore, the feedforward control amount becomes a function of the transmission torque, and it becomes easy to correct the feedforward control amount by using the value corresponding to this transmission torque. There is an effect that can be improved.

[0060]

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a shift control device for a continuously variable transmission according to the present invention.

FIG. 2 is a block diagram showing a main part of a shift control device for a continuously variable transmission according to a first embodiment of the present invention.

FIG. 3 is a block diagram showing a main part of the first embodiment of a shift control device for a continuously variable transmission according to the present invention.

FIG. 4 is a diagram for explaining the operation of FIG.

5 is a flowchart for explaining the operation of FIG.

FIG. 6 is a diagram for explaining the operation of FIG.

FIG. 7 is a diagram showing the relationship between the control current of the hydraulic control valve and the output hydraulic pressure in the first embodiment of the shift control device for a continuously variable transmission according to the present invention.

FIG. 8 is a block diagram showing a main part of the first embodiment of a shift control device for a continuously variable transmission according to the present invention.

FIG. 9 is a block diagram showing a main part of the first embodiment of a shift control device for a continuously variable transmission according to the present invention.

FIG. 10 is a block diagram showing a second embodiment of a shift control device for a continuously variable transmission according to the present invention.

FIG. 11 is a block diagram showing a main part of a shift control device for a continuously variable transmission according to a second embodiment of the present invention.

12 is a flowchart for explaining the operation of FIG. 11. FIG.

FIG. 13 is a diagram showing a map for determining a target gear ratio.

FIG. 14 is a diagram showing a map for determining a hydraulic pressure ratio.

[Explanation of symbols]

2 engine output shaft, 4 CVT input shaft, 5 primary pulley, 7 secondary pulley, 8 CVT, 9 CVT output shaft, 10 hydraulic pump, 11 secondary hydraulic control valve, 12
Primary side hydraulic control valve, 18 engine speed detector,
19 CVT input shaft rotation speed detector, 20, 20A controller, 21 throttle opening detector, 22 throttle valve, 23 CVT output shaft rotation speed detector, 24
Shift position detector, 25 braking state detector, 30 actual gear ratio calculating means, 31 first target gear ratio calculating means, 32
Operating mode determining means, 34 input torque calculating means, 3
5 2nd target gear ratio calculation means, 36 primary side current control means, 37 target secondary side pressure calculation means, 38 secondary side current control means, 40 target primary side pressure calculation means, 43 feedforward control calculation section, 47 feedback Control calculation unit, 341 shift torque calculation unit, 342, 344 input torque calculation unit, 343, 345 transmission torque determination unit.

Front page continuation (51) Int.Cl. ⁷ identification code FI F16H 59:42 F16H 59:42 59:68 59:68 101: 02 101: 02 (58) Fields investigated (Int.Cl. ⁷ , DB name) ) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (4)

(57) [Claims] 1. A fixed pulley piece, a movable pulley piece, and the same.
Effective diameter with hydraulic servo on movable pulley piece
Is a continuously variable primary side pulley and secondary side pulley, and these
A drive belt stretched between pulleys and a hydraulic pressure source are generated.
Adjusts the hydraulic pressure and supplies it to the hydraulic servo of the secondary pulley.
The secondary side hydraulic control valve and the secondary side pressure are adjusted to regulate the primary side pool.
With a primary side hydraulic pressure control valve that supplies to the hydraulic servo of
And continuously change the rotation of the engine and transmit it to the load.
In the continuously variable transmission, Each of the primary pulley and the secondary pulley
Rotation speed detecting means for detecting rotation, The actual gear ratio is calculated from the ratio of the rotational speeds from the rotational speed detection means.
An actual gear ratio calculating means for calculating Required load amount to detect the load amount required for the above engine
Detection means, At least the output of the required load amount detection means and the load
Target shift that sequentially determines the target gear ratio based on the rolling speed
A ratio determining means, The above 1 is set so that the actual gear ratio matches the target gear ratio.
A gear ratio control means for controlling the secondary hydraulic control valve, Transmission torque for estimating the torque transmitted by the continuously variable transmission
Computing means, According to the transmission torque estimated by the transmission torque calculation means
The secondary side hydraulic control valve is controlled to control the primary side pulley and
And the secondary side that generates the necessary clamping force on the secondary pulley
And a pressure control means, The transmission torque calculation means is for changing the transmission ratio of the continuously variable transmission.
The first transmission torque corresponding to the speed change ratio of gear ratio
From the estimated shift torque calculation unit and engine output torque
Calculate the second transmission torque input to the continuously variable transmission
Input torque calculation unit, the first transmission torque and the first transmission torque
Select one of the 2 transmission torques and set it as the above transmission torque.
Transmission torque determining unitThen The transmission torque determining unit determines that the required load amount is greater than a predetermined value.
If it is small, the engine is driven, and the target is
If the gear ratio is increasing or the engine is running and the
When the gear ratio is decreasing,
The larger one of the second transmission torques is the transmission torque.
Determined as Luk, otherwise, Second transmission above
Torque is the above transmission torque Infinite change characterized by
Speed change control device. 2. The continuously variable shift according to claim 1, wherein the shift control means has a feedforward control calculation unit and sets the feedforward control amount to a value corresponding to at least the transmission torque. Gear shift control device. 3. A fluid coupling connected to an engine, and a fixing
The pulley piece, the movable pulley piece, and the movable pulley piece
Primary side with continuously variable effective diameter that has a hydraulic servo
Pulley and secondary pulley, and tension between these pulleys
The drive belt and the hydraulic pressure generated by the hydraulic pressure source are regulated to
Secondary hydraulic control valve that supplies hydraulic servo of secondary pulley
And the secondary side pressure is adjusted to the hydraulic servo of the primary side pulley.
And a primary side hydraulic pressure control valve for supplying the
A continuously variable transmission that continuously changes the output rotation and transmits it to the load.
At Each of the primary pulley and the secondary pulley
Rotation speed detecting means for detecting rotation, The actual gear ratio is calculated from the ratio of the rotational speeds from the rotational speed detection means.
An actual gear ratio calculating means for calculating Required load amount to detect the load amount required for the above engine
Detection means, At least the output of the required load amount detection means and the load
Target shift that sequentially determines the target gear ratio based on the rolling speed
A ratio determining means, The above 1 is set so that the actual gear ratio matches the target gear ratio.
A gear ratio control means for controlling the secondary hydraulic control valve, Transmission torque for estimating the torque transmitted by the continuously variable transmission
Computing means, According to the transmission torque estimated by the transmission torque calculation means
The secondary side hydraulic control valve is controlled to control the primary side pulley and
And the secondary side that generates the necessary clamping force on the secondary pulley
And a pressure control means, The transmission torque calculation means is for changing the transmission ratio of the continuously variable transmission.
The first transmission torque corresponding to the speed change ratio of gear ratio
The estimated shift torque calculation unit and the output torque of the fluid coupling
From the third transmission torque input to the above continuously variable transmission
An input torque calculation unit for calculating, and the above first transmission torque
Select one of the above-mentioned third transmission torques and select the above-mentioned transmission torque.
The transmission torque determining unitThen The transmission torque determining unit determines that the output torque of the fluid coupling is
If it is smaller than the specified value and the engine is in a driven state
The target gear ratio is increasing or the engine is operating.
When the target gear ratio is decreasing, the first transmission
Whichever is greater, the ultimate torque or the third transmission torque
Determined as the above transmission torque, otherwise, above
The third transmission torque is the above transmission torque Characterized by
Of a continuously variable transmission for a vehicle. Wherein said shift control means includes a feed-forward control computation unit, the feed forward control amount, at least stepless according to claim 3, characterized in that a value corresponding to the transmission torque Gear shift control device.