JP3301259B2 - Transmission control device for toroidal type 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 an input disk and an output disk which are arranged opposite to each other, and a stepless speed change of the rotation of the input disk in accordance with a tilt angle with respect to the two disks, and the rotation is transmitted to the output disk. The present invention relates to a shift control device for a toroidal-type continuously variable transmission including a shift unit including a pair of power rollers.

[0002]

2. Description of the Related Art A toroidal type continuously variable transmission mounted on an automobile is generally a double cavity type toroidal type continuously variable transmission in which two transmission units are arranged on the same shaft. The toroidal-type continuously variable transmission includes an input shaft to which an engine output is input, an input disk rotatably supported with respect to the input shaft, and an input disk disposed opposite to each of the input disks. A rotatable output disk, a tiltable power roller disposed between a pair of opposing input and output disks and transmitting torque from the input disk to the output disk; A pressing member disposed between the pair of flange portions provided on the input shaft and the input disk and acting on the input disk to change the pressure contact force of the power roller according to the magnitude of the input torque. Then, the power roller is tilted, and the rotation of the input disk is transmitted to the output disk in a stepless manner according to the tilt angle. In the toroidal-type continuously variable transmission, the tilt of the power roller is performed by a shift control device. The shift control device is
Conventionally, various types (for example, Japanese Patent Application Laid-Open No. 62-12826)
7 is known, for example, there is one as shown in FIG.

As shown in FIG. 6, a pair of power rollers 2
Are arranged so as to be sandwiched between an input disk 1 and an output disk (not shown) arranged oppositely, and are rotatably supported by respective support members called trunnions 4. That is, the power roller 2 is supported by the trunnion 4 by the eccentric shaft 5. Each trunnion 4 is supported by a transmission casing (not shown) so as to be rotatable and movable in the axial direction. That is, each trunnion 4 has a tilt shaft 6, moves in the axial direction of the tilt shaft 6, and can rotate about the tilt shaft 6. A piston 7 is fixed to the tilt shaft 6 of the trunnion 4, and the piston 7 is slidably provided in a hydraulic cylinder 8 formed in a transmission casing. The hydraulic cylinder 8 has two cylinder chambers defined by a piston 7, namely, a speed-up cylinder chamber 8a and a deceleration-side cylinder chamber 8a.
b is formed.

[0004] Each cylinder chamber 8a, 8b of the hydraulic cylinder 8
Communicates with the spool valve 10 through oil passages 9a and 9b. The spool 11 slidably disposed in the spool valve 10 is held at a neutral position by springs 12 disposed at both ends in the axial direction. The spool valve 10 has a Sa port formed at one end and an Sb port formed at the other end. The pilot pressure Sa is supplied to the Sa port via a solenoid valve 13a, and the Sb port is provided via a solenoid valve 13b. The pilot pressure Sb is supplied. Also,
The spool valve 10 is connected to a line pressure (hydraulic pressure source) P
An L port, an A port connected to the speed-increasing cylinder chamber 8a via the oil passage 9a, a B port connected to the deceleration cylinder chamber 8b via the oil passage 9b, and two T ports connected to the tank. Have. The solenoid valves 13a and 13b are configured to operate according to a control signal output from the controller 14.

[0005] A precess cam 1 is provided at the tip of one tilt shaft 6.
5 is connected, one end of a lever 16 pivotally connected at the center thereof contacts the precess cam 15, and the other end of the lever 16 is connected to a potentiometer 17. Potentiometer 17
Detects the axial displacement and tilt angle of the tilt shaft 6 of the trunnion 4 as a combined displacement amount, and inputs a detection signal to a controller (TCM: Transmission Control Module) 14. The shift control device further includes various sensors such as a vehicle speed sensor 18, an engine rotation sensor 19, and a throttle opening sensor 20. The vehicle speed, the engine rotation speed, and the throttle opening detected by these sensors are also provided. Is input to the controller 14.

In the toroidal type continuously variable transmission, the trunnion 4 is set at the neutral position (the position where the rotation center axis of the power roller 2 crosses the rotation center axes of the input disk 1 and the output disk).
When the trunnion 4 is displaced in the tilt axis direction (that is, in the axial direction of the tilt shaft 6), the trunnion 4 tilts around the tilt shaft 6 in a direction and at a speed corresponding to the direction and the amount of displacement. The shift control is performed by utilizing the property that the shift is performed by the tilt.

Next, the operation of the transmission control device will be described. First, the controller 14 calculates the actual transmission ratio from the combined displacement of the trunnion 4 detected by the potentiometer 17, and calculates the actual transmission ratio between the transmission ratio and the target transmission ratio. The target displacement of the trunnion 4 is set according to the deviation, and the solenoid valve 13
a, and outputs a control signal to 13b. Accordingly, pilot pressures Sa and Sb are supplied to both ends of the spool valve 10 from the solenoid valves 13a and 13b. At this time, the relationship between the pilot pressures Sa and Sb supplied to the spool valve 10 is S
When a> Sb, the spool 11 shifts to the left in FIG. 6, the oil passage 9a communicates with the pressure source via the PL port, and the oil passage 9b communicates with the tank via the T port. The pressure Pa of the oil passage 9a becomes larger than the pressure Pb of the oil passage 9b (Pa> Pb). As a result, due to the pressure difference between the cylinder chambers 8a and 8b, the left trunnion 4 in FIG. 6 is displaced upward, and the right trunnion 4 is displaced downward. With this displacement, the trunnions 4 tilt around the tilt shaft 6, respectively, and the speed change operation is started to the speed increasing side. Feedback control is performed by the controller 14 so that the actual speed ratio approaches the target speed ratio. When the actual gear ratio approaches the target gear ratio, the target displacement of the trunnion 4 approaches zero, and when the actual gear ratio matches the target gear ratio, the target displacement of the trunnion 4 becomes zero and the gear shift operation ends. I do.

[0008]

In the prior art shown in FIG. 6, when the speed ratio matches the target speed ratio, the pilot pressures Sa and S acting on both ends of the spool valve are changed.
b are equal and the trunnion displacement is zero. However, the spool neutral position of the spool valve may be shifted to one of the spool valves due to manufacturing variations of the spool valve or the springs provided at both ends thereof, or their deterioration over time. In this case, the pressure Pa in the speed-up cylinder chamber 8a and the pressure Pb in the deceleration-side cylinder chamber 8b become inconsistent, and the shift is started again or the gear ratio converges at a speed ratio different from the target speed ratio. Occurs.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and correct the neutral position of the spool valve, thereby converging the gear ratio other than the target gear ratio due to manufacturing variations of the spool valve or the like and aging. An object of the present invention is to provide a shift control device for a toroidal-type continuously variable transmission that can prevent the start of a re-shift.

[0010]

The present invention is configured as follows to achieve the above object. That is, the present invention provides an input disk and an output disk which are disposed opposite to each other, and a pair of transmission disks which transmit the rotation to the output disk by continuously changing the rotation of the input disk in accordance with a change in the tilt angle with respect to the both disks. A power roller, a pair of trunnions rotatably supporting the power roller and displaceable in the tilt axis direction, a hydraulic cylinder having two cylinder chambers and displacing the trunnion in the tilt axis direction, and a spool neutral A spool valve that shuts off the cylinder chamber when in a position and selectively communicates each cylinder chamber with a hydraulic pressure source and a tank when the spool is displaced from the neutral position, and controls a position of the spool. A solenoid valve, and a controller that outputs a duty corresponding to a deviation between a speed ratio and a target speed ratio to the solenoid valve. The controller responds to a correction execution condition for executing the correction of the neutral position of the spool valve, and in accordance with an error integrated value calculated by time-integrating an error of a gear ratio with respect to a target gear ratio. A duty correction amount relating to the error of the neutral position of the spool valve is calculated.
The present invention relates to a shift control device for a toroidal-type continuously variable transmission, which performs control for correcting y with the duty correction amount. Here, the duty is O in pulse width modulation control.
It refers to the time ratio between N and OFF. That is, the duty (%) is given by the following equation. duty = (one cycle of solenoid ON time / solenoid operation cycle) × 100

In the transmission control apparatus for a toroidal-type continuously variable transmission, the feedback gain to the solenoid valve is reduced when the correction execution condition is satisfied and the gear ratio fluctuates. , The feedback gain is controlled to increase as the correction proceeds.

In the transmission control device for a toroidal-type continuously variable transmission, the controller determines the correction execution condition and outputs a signal when the correction execution condition is satisfied, and the correction execution determination means. A speed ratio change presence / absence determining means for determining the presence or absence of a change in the speed ratio by inputting a signal from the controller and outputting a signal, and calculating an error integrated value by time-integrating an error of the speed ratio with respect to the target speed ratio Speed ratio error calculating means, a first storage section storing a correspondence table between a predetermined error integrated value and a change amount of the feedback gain, and the first storage section in response to a signal indicating a change from the speed ratio change presence / absence determining means, A change amount of the feedback gain according to the error integrated value calculated according to the correspondence table stored in the storage unit is calculated. A feedback gain change amount calculating means for setting the change amount of the feedback gain to zero by inputting the second signal, a second storage unit storing a correspondence table between a predetermined error integrated value and a duty correction amount, A correction amount calculating means for calculating a duty correction amount according to the error integrated value calculated according to the correspondence table stored in the second storage unit; and the duty ratio based on the calculated change amount of the feedback gain and the duty correction amount.
It is preferable to have a duty calculating means for correcting and outputting the result to the solenoid valve. The means for calculating the duty in accordance with the deviation between the gear ratio and the target gear ratio is duty calculation means regardless of whether or not the correction execution condition is satisfied.

Further, the error correction execution condition is, for example,
Satisfaction can be achieved when an idling condition is detected. That is, the condition for executing the correction regarding the error of the neutral position of the spool valve is restricted. For example, the condition may be that the target gear ratio is constant and the input from the outside to the transmission (for example, torque or rotation speed) does not change. Specifically, this is the case where the drive position is “P” or “N” and it is detected that the engine is idling. As a method of detecting the idling state of the engine, for example, the engine speed, the accelerator pedal depression amount,
The engine suction negative pressure is detected, and these values are within a predetermined range.

[0014]

The shift control device for a toroidal-type continuously variable transmission according to the present invention is configured as described above and operates as follows. That is, the shift control device of the toroidal-type continuously variable transmission, when there is an error in the neutral position of the spool valve, integrates the deviation between the actual speed ratio and the target speed ratio, that is, the error of the speed ratio with respect to the target speed ratio over time. Then, the error integrated value becomes a positive or negative value, and the duty to be output to the solenoid valve is corrected according to the magnitude and sign of the value. After the correction, the error integrated value approaches zero, and by repeating the correction, the error is corrected to a level at which there is no problem in control. As a result, the neutral position of the spool valve is corrected to a true neutral position.

When the gear ratio fluctuates, not only the neutral position of the spool valve is corrected, but also the feedback to the solenoid valve in accordance with the magnitude of the error integrated value and the sign of the positive or negative. Change the gain. That is,
Control becomes easier by lowering the feedback gain, and the response becomes better by increasing the feedback gain.Therefore, the feedback gain to the solenoid valve is first reduced, and as the correction proceeds, the feedback gain is increased. To the normal set value. By performing such control, the gear ratio quickly converges to reach the target gear ratio.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a toroidal-type continuously variable transmission according to an embodiment of the present invention; FIG. 1 is a functional block diagram of a controller in a shift control device according to the present invention. The shift control device of this embodiment has substantially the same configuration as the conventional shift control device shown in FIG. 6, but the difference between the two is in the configuration of the controller and the type of sensor used. The shift control device includes, as sensors, a number of sensors in addition to the vehicle speed sensor 18, the engine rotation sensor 19, and the throttle opening sensor 20, in order to determine whether or not the condition for executing the correction is satisfied. In the following description of this embodiment, description of portions having the same configuration as the conventional one will be omitted.

The controller 14 determines whether or not the correction execution condition is satisfied, and outputs a signal when the condition is satisfied. The controller 14 receives a signal from the correction execution determination unit 21 as an input. Speed ratio change presence / absence determining means 33 for determining the presence or absence of a change in the speed ratio and outputting a signal, and a speed ratio error calculating means for calculating the error integrated value by time-integrating the error of the speed ratio with respect to the target speed ratio 22, a first storage unit 2 that stores a correspondence table between an error integrated value obtained in advance by an experiment and a change amount of a feedback gain
3. When a signal indicating a change is input from the speed ratio change presence / absence determining means 33, the change amount of the feedback gain according to the calculated error integrated value is calculated in accordance with the correspondence table stored in the first storage unit 23. The feedback gain change amount calculating means 24 for setting the change amount of the feedback gain to zero by inputting a signal having no change from the speed ratio change presence / absence determining means 33, the difference between the error integrated value and the duty correction amount obtained in advance through experiments. The second storage unit 25 storing the correspondence table, and d corresponding to the calculated error integrated value according to the correspondence table stored in the second storage unit 25
The duty amount corresponding to the deviation between the gear ratio and the target gear ratio is corrected by the correction amount calculating means 26 for calculating the duty correction amount, and the calculated change amount of the feedback gain and the duty correction amount, and the solenoid valves 13a and 13b. Dut output to
y operation means 27 is provided. Further, the duty correction amount according to the error integrated value may be calculated according to a map (corresponding table) obtained in advance by experiment as described above, or may be calculated in the minimum resolution unit of the output signal to the solenoid valves 13a and 13b. It may be fixed.

The engine rotation sensor 19, the accelerator depression amount detection sensor 28, the pressure sensor 29, and the shift position sensor 30 detect the engine speed, the accelerator depression amount, the engine suction negative pressure, and the shift position, respectively, and execute correction by the controller 14. Input to the judgment means 21. The correction execution determination means 21 executes correction when the input engine speed, accelerator depression amount, and engine suction negative pressure are within predetermined ranges and the drive position is in the parking range “P” or the neutral range “N”. Judge that the conditions are satisfied. When the correction execution condition is satisfied, the target gear ratio does not change and remains constant. The method of calculating the target speed ratio and the actual speed ratio is the same as the conventional one. The target gear ratio is an optimal gear ratio at the present time, and is determined from the vehicle speed, the engine speed, and the throttle opening detected by the vehicle speed sensor 18, the engine rotation sensor 19, and the throttle opening sensor 20. It is calculated by the calculating means 31. The actual gear ratio is calculated from the combined displacement amount of the trunnion 4 detected by the potentiometer 17, that is, the combined displacement amount of the axial displacement of the tilting shaft 6 and the tilting angle of the tilting shaft 6, from the gear ratio calculating means 32 of the controller 14. It is calculated by

Next, with reference to the flowcharts of FIGS. 2 and 3, a description will be given of the correction execution control in the shift control device of the toroidal type continuously variable transmission according to the present invention. To correct the error in the neutral position of the spool valve 10, a certain condition, that is, a condition for executing the correction, must be satisfied.
Therefore, first, in a main routine, it is determined whether or not the engine is idling (S1). If it is determined that the vehicle is in the idling state, the correction execution condition is satisfied. In this case, n = 0 for the number n of times of repeating the integration, and E for the integrated value E of the gear ratio error.
(0) = 0 and initialization is performed. Next, the speed ratio e is detected (S2), and the actual speed ratio e and the target speed ratio e are detected.
Integration that is integrated in the gear ratio error is performed between ₀ and the deviation of _{(e-e 0) (S4} ). The integration is repeated N times (S5). It is determined whether there is a change in the gear ratio during the integration (S3), and if there is a change in the gear ratio, N integrations are performed (S4, S5). When the N-time integration is completed, a feedback gain change amount ΔG corresponding to the magnitude of the calculated error integrated value E is calculated according to a map obtained in advance through experiments (S6). Solenoid valves 13a, 13
The dutyA ₀ and dutyB ₀ output to b are calculated by the following equation (1) (S7). dutyA ₀ = 50% + (G−ΔG) (e−e ₀ ) dutyB ₀ = 50% − (G−ΔG) (e−e ₀ ) (1) where G and ΔG are positive proportional constants It is. If there is no change in the gear ratio in step 3 (S3), the feedback gain change amount ΔG = 0 is set (S8). That is, d
dutyA ₀ and dutyB ₀ are given by the following equation (2). dutyA ₀ = 50% + G (e−e ₀ ) dutyB ₀ = 50% −G (e−e ₀ ) (2) As described above, when there is a change in the gear ratio, as shown in the above equation (1) In the case where there is no change in the gear ratio, the duty is set to the normal value as shown in the above equation (2).
A ₀ and duty B ₀ are calculated.

Next, the correction of the neutral position of the spool valve will be described. Again, initialization is performed with the number of repetitions n = 0 and the integrated value E of the gear ratio error set to E (0) = 0, and the deviation (e−e ₀ ) between the actual gear ratio e and the target gear ratio e _0. , That is, the gear ratio error is integrated (S9). The integration is repeated N times (S10). When the accumulation of N times is completed, d is corrected to correct the neutral position of the spool valve.
The duty correction amount (△ duty) is calculated. That is, according to the map obtained in advance through experiments, the duty correction amount (△ d
uty) is calculated (S11). DutyA ₀ based on the feedback gain change amount ΔG calculated in step 6
And dutyB ₀ and the duty calculated in step 11
From the correction amount (△ duty), each solenoid valve 13a,
The dutyA and the dutyB to be output to 13b are calculated by the following equation (3) (S12). _{dutyA = dutyA 0 + △ duty dutyB} = dutyB 0 - △ duty (3) Then, each outputs a duty A and duty B each solenoid valve 13a, to 13b (S13).

Returning to the main routine S1 (S14), when the correction execution condition is satisfied, that is, in the idling state, the above steps 1 to 14 are repeated. If there was a change in the gear ratio, the feedback gain was first reduced, and the feedback gain was controlled to increase as the correction progressed.Therefore, the neutral position of the spool valve was quickly corrected by repeating the feedback. Will be

Next, the temporal change of the speed ratio when the speed ratio converges to the target speed ratio will be examined. FIGS. 4 and 5 show the temporal change of the deviation between the actual gear ratio and the target gear ratio during gear shifting. In FIGS. 4 and 5, the integrated values (shaded portions in the drawings) obtained when the deviation between the actual speed ratio and the target speed ratio are integrated over time are both negative values. If there is an error in the neutral position of the spool valve, the actual speed ratio oscillates near the target speed ratio as shown in FIG. 4, or the actual speed ratio deviates from the target speed ratio as shown in FIG. Stabilizes with leaving. At this time,
As shown in FIG. 4, when the change in the gear ratio is large, if the feedback gain of the output signal output from the controller 14 to the solenoid valves 13a and 13b is lower than a normal set value, a state as shown in FIG. 5 is obtained. Accordingly, if the feedback gain is reduced and the correction of the neutral position of the spool valve 10 is advanced and the feedback gain approaches the normal set value, that is, if the feedback gain is increased,
The actual gear ratio can be quickly and completely matched to the target gear ratio.

[0023]

The transmission control apparatus for a toroidal-type continuously variable transmission according to the present invention is configured as described above.
It has the following effects. That is, the transmission control device of the toroidal type continuously variable transmission detects the neutral position of the spool valve according to the integrated value of the deviation between the actual speed ratio and the target speed ratio, and corrects the output signal to the solenoid valve. As a result, it is possible to prevent convergence at a speed ratio different from the target speed ratio, and to prevent a phenomenon in which the speed change is started again after the speed ratio reaches the target speed ratio. Can be prevented.

Further, when the gear ratio fluctuates, the shift control device lowers the feedback gain to the solenoid valve, and as the correction of the neutral position of the spool valve progresses,
Since the feedback gain is controlled to be increased, it is possible to prevent the gear ratio from fluctuating while vibrating largely. Therefore, in this shift control device, the speed ratio converges to the target speed ratio quickly. Further, the shift control device controls the neutral position of the spool valve whenever the correction execution condition is satisfied. Even if the spool valve shifts in the neutral position due to aging, the shift can be easily detected,
It is possible to correct the neutral position of the spool valve to the true neutral position, and it is possible to always perform stable shift control.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a controller in a shift control device for a toroidal-type continuously variable transmission according to the present invention.

FIG. 2 is a flowchart showing a part of a correction execution procedure in the transmission control device of the toroidal type continuously variable transmission according to the present invention.

FIG. 3 is a flowchart illustrating a correction execution procedure following the flowchart of FIG. 2;

FIG. 4 is a graph showing an example of a temporal change of a deviation between an actual speed ratio and a target speed ratio when a change in the speed ratio is large.

FIG. 5 is a graph showing an example of a temporal change of a deviation between an actual speed ratio and a target speed ratio when a change in the speed ratio is small.

FIG. 6 is a schematic diagram showing a conventional shift control device for a toroidal-type continuously variable transmission.

[Explanation of symbols]

 Reference Signs List 1 input disk 2 power roller 4 trunnion 6 tilting shaft 8 hydraulic cylinder 8a, 8b cylinder chamber 10 spool valve 11 spool 13a, 13b solenoid valve 14 controller 21 correction execution determining means 22 gear ratio error calculating means 23 first storage unit 24 feedback Gain change amount calculation means 25 Second storage unit 26 Correction amount calculation means 27 Duty calculation means 33 Speed ratio fluctuation presence / absence determination means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 61/00-61/24 F16H 15/38

Claims (4)

(57) [Claims] An input disk and an output disk disposed opposite to each other, and a pair of power transmitted to the output disk by continuously changing the rotation of the input disk in accordance with a change in a tilt angle with respect to the both disks. A roller, a pair of trunnions rotatably supporting the power roller and displaceable in the tilt axis direction, a hydraulic cylinder having two cylinder chambers and displacing the trunnion in the tilt axis direction, and a spool in a neutral position. A spool valve that selectively closes the cylinder chambers to a hydraulic pressure source and a tank when the spool is displaced from the neutral position, and a solenoid that controls the position of the spool. A valve, and a controller that outputs a duty corresponding to a deviation between a gear ratio and a target gear ratio to the solenoid valve. The controller responds to a correction execution condition for executing the correction of the neutral position of the spool valve, and responds to the error integrated value calculated by time-integrating the error of the speed ratio with respect to the target speed ratio. A shift control device for a toroidal-type continuously variable transmission, wherein a duty correction amount related to an error in a neutral position of a valve is calculated, and control is performed to correct the duty with the duty correction amount. 2. When the correction execution condition is satisfied and the gear ratio is fluctuating, the feedback gain to the solenoid valve is reduced, and the feedback gain is increased as the correction progresses. The shift control device for a toroidal-type continuously variable transmission according to claim 1, wherein the shift control is performed. 3. The controller according to claim 1, wherein the controller determines the correction execution condition and outputs a signal when the condition is satisfied, and receives a signal from the correction execution determiner to change the speed ratio. Speed ratio variation presence / absence determining means for determining the presence / absence of the gear ratio and outputting a signal; speed ratio error calculating means for time-integrating an error of the gear ratio with respect to the target gear ratio to calculate an error integrated value; A first storage unit storing a correspondence table between the value and the amount of change in the feedback gain, and an error calculated according to the correspondence table stored in the first storage unit in response to a signal indicating a change from the speed ratio change presence / absence determining means. The amount of change in the feedback gain according to the integrated value is calculated. Feedback gain change amount calculating means for setting the change amount of the change to zero, a second storage unit storing a correspondence table between a predetermined error integrated value and a duty correction amount, and a calculation according to a correspondence table stored in the second storage unit. Correction amount calculating means for calculating a duty correction amount according to the calculated error integrated value, and duty calculating means for correcting the duty with the calculated change amount of the feedback gain and the duty correction amount and outputting the corrected duty to the solenoid valve. The shift control device for a toroidal-type continuously variable transmission according to claim 2, comprising: 4. The shift control device for a toroidal type continuously variable transmission according to claim 3, wherein the correction execution condition is satisfied when an idling state is detected.