JP2011174486A - Continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a configuration providing accelerating force required for avoiding risk even during traveling with a manual gear shift mode selected. <P>SOLUTION: In this continuously variable transmission, a manual gear shift function is provided for adjusting a gear ratio based on operation by a driver to any one of values in a plurality of stages as predetermined gear ratios mutually different, and an automatic gear shift function is provided for automatically adjusting the gear shift ratio according to an operating condition at that point without being based on the operation by the driver. A function is provided for automatically adjusting to the gear ratio that determined as the optimum gear ratio according to vehicle speed at the time and the amount that an accelerator pedal is depressed, even if the driver does not change the gear ratio to a deceleration side based on the manual gear shift function when the amount that the accelerator pedal is depressed is suddenly increased with any shift stage of the plurality of stages selected based on the gear shift operation by the driver and the gear ratio adjusted to a gear ratio corresponding to the shift stage. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to an improvement of a continuously variable transmission used as an automatic transmission for a vehicle (automobile), for example.
Specifically, in the gear ratio control device, in addition to the automatic gear shift mode in which the gear ratio is automatically selected and controlled based on the vehicle speed, the accelerator opening, etc., the manual gear shift mode in which the driver selects the gear ratio is provided. The structure having a function to be realized is intended to realize a structure that can reliably obtain an acceleration force necessary for avoiding a danger or the like even when traveling with the manual transmission mode selected.

  The use of a toroidal continuously variable transmission as a vehicle (automobile) transmission is described in, for example, many publications and is well known in some implementations. Also, a continuously variable transmission that combines a toroidal continuously variable transmission and a differential unit (for example, a planetary gear transmission that is a gear-type differential unit) in order to increase the fluctuation range of the transmission ratio is disclosed in, for example, a patent. It has been widely known from the past, for example, as described in Documents 1-2. Among them, Patent Document 1 discloses a mode in which power is transmitted only by a toroidal-type continuously variable transmission (for example, a first mode and a low speed mode), and a main power is transmitted by a planetary gear type transmission which is a differential unit. In addition, there is described a continuously variable transmission having a mode (for example, a second mode, a high speed mode) that realizes a so-called power split state in which a gear ratio is adjusted by the toroidal continuously variable transmission. . Further, in Patent Document 2, the rotation state of the output shaft is rotated forward with a so-called geared neutral (GN) state in which the rotation state of the output shaft is stopped while the input shaft is rotated in one direction. A continuously variable transmission having a mode (for example, a first mode and a low speed mode) switched to reverse rotation is described.

  6 to 7 show a continuously variable transmission having a mode described in Patent Document 2 that can realize a geared neutral state. FIG. 6 shows a block diagram of the continuously variable transmission, and FIG. 7 shows a hydraulic circuit for controlling the continuously variable transmission. The output of the engine 1 is input to the input shaft 3 via the damper 2. The power transmitted to the input shaft 3 is transmitted to the planetary gear type transmission 5 which is a differential unit, either directly or via the toroidal continuously variable transmission 4. The differential components of the constituent members of the planetary gear type transmission 5 are taken out to the output shaft 9 via the clutch device 6, that is, the low speed and high speed clutches 7 and 8 shown in FIG. The toroidal continuously variable transmission 4 includes input and output disks 10 and 11, a plurality of power rollers 12, a plurality of trunnions (not shown), an actuator 13 (FIG. 7), A pressing device 14 and a gear ratio control unit 15 are provided.

  Of these, the input-side and output-side disks 10 and 11 are arranged concentrically and relatively freely rotatable. Each of the power rollers 12 is sandwiched between inner surfaces of the input and output disks 10 and 11 facing each other, and power is supplied between the input and output disks 10 and 11. (Force, torque) is transmitted. Each trunnion supports each power roller 12 rotatably. The actuator 13 is a hydraulic type, and the trunnions supporting the power rollers 12 are displaced in the axial directions of the pivots provided at both ends thereof, so that the input side disk 10 and the output side The gear ratio with the disk 11 is changed. The pressing device 14 is a hydraulic device that generates a pressing force proportional to the hydraulic pressure with the introduction of the hydraulic pressure, and presses the input side disk 10 and the output side disk 11 in a direction approaching each other. . The gear ratio control unit 15 controls the displacement direction and the displacement amount of the actuator 13 in order to set the gear ratio between the input side disk 10 and the output side disk 11 to a desired value.

  In the illustrated example, the transmission ratio control unit 15 includes a controller (ECU) 16, a stepping motor 17 that is switched based on a control signal from the controller 16, a line pressure control electromagnetic on-off valve 18, and the like. The gear ratio correcting solenoid valve 19, the shift solenoid valve 20, and the control valve device 21 whose operation state can be switched by these members 17 to 20 are constituted. The control valve device 21 includes a transmission ratio control valve 22, a differential pressure cylinder 23, correction control valves 24a and 24b, and high-speed clutch and low-speed clutch switching valves 25 and 26 (FIG. 7). It is a combination. Of these, the gear ratio control valve 22 controls the supply and discharge of hydraulic pressure to and from the actuator 13. Further, the differential pressure cylinder 23 is configured to control the transmission ratio control valve so as to correct the transmission ratio of the toroidal type continuously variable transmission 4 according to the force (passing torque) passing through the toroidal type continuously variable transmission 4. This is for adjusting the switching state of 22. The correction control valves 24 a and 24 b control the supply and discharge of pressure oil to and from the differential pressure cylinder 23. Further, the switching valves 25 and 26 for the high speed clutch and the low speed clutch switch the introduction state of the pressure oil to the low speed and high speed clutches 7 and 8, respectively.

  Further, the pressure oil discharged from the oil supply pump 27 (27a, 27b in FIG. 7) driven by the power extracted from the damper 2 portion is sent to the control valve device 21 and the pressing device 14. That is, the pressure oil sucked from the oil reservoir 28 (FIG. 7) and discharged by the oil supply pumps 27a and 27b is adjusted to a predetermined pressure by the pressing force adjusting valve 29 and the low pressure side adjusting valve 30 (FIG. 7). Among these, the pressing force adjusting valve 29 includes a hydraulic pressure corresponding to a hydraulic pressure difference (differential pressure) existing between a pair of hydraulic chambers 31a and 31b provided with a piston sandwiched between the actuator 13 and the control. The valve opening pressure is adjusted based on the introduction of the hydraulic pressure based on the opening / closing of the line pressure control electromagnetic switching valve 18 controlled by the command from the vessel 16. Based on such adjustment of the valve opening pressure, the pressing force generated by the pressing device 14 is regulated to an optimum value according to the operating state at that time.

  The pressure oil adjusted by the pressure adjusting valve 29 is supplied to the low speed clutch via the manual hydraulic pressure switching valve 32 and the pressure reducing valve 33, the high speed clutch switching valve 25 or the low speed clutch switching valve 26. 7 or the hydraulic chamber of the high speed clutch 8. The low speed clutch 7 out of the low speed and high speed clutches 7 and 8 is connected when realizing a low speed mode in which the speed reduction ratio is increased (including an infinite gear ratio (including geared / neutral state)). At the same time, the connection is broken when the high speed mode for reducing the reduction ratio is realized. On the other hand, the high speed clutch 8 is disconnected when realizing the low speed mode and is connected when realizing the high speed mode. Further, the supply / discharge state of the pressure oil to the low speed and high speed clutches 7 and 8 is switched according to the switching of the shift solenoid valve 20.

  FIG. 8 shows an example of the relationship between the speed ratio (1 / speed ratio, speed increasing ratio) of the toroidal type continuously variable transmission 4 and the speed ratio of the continuously variable transmission as a whole. For example, in the low speed mode in which the low speed clutch 7 is connected and the high speed clutch 8 is disconnected, the gear ratio of the toroidal-type continuously variable transmission 4 is set to the geared neutral state as shown by the solid line α. As the actual value (GN value, GN point) is changed to the deceleration side, the speed ratio of the continuously variable transmission as a whole increases from the stopped state (speed ratio 0 state) to the forward direction (+: forward rotation direction). It can be changed in the direction of speed. Similarly, as the GN value is changed from the GN value to the speed increasing side, the speed is also changed from the stop state to the speed increasing direction in the reverse direction (-: reverse direction). On the other hand, in the high speed mode in which the high speed clutch 8 is connected and the low speed clutch 7 is disconnected, the speed ratio of the toroidal continuously variable transmission 4 is changed to the higher speed side as indicated by the solid line β. As a result, the speed ratio of the continuously variable transmission as a whole can be changed to the speed increasing side (in the forward direction).

  In a vehicle incorporating a continuously variable transmission as described above, it is based on the driving state (driving state) of the vehicle obtained from the operation of the accelerator pedal (accelerator opening degree) or the traveling speed (vehicle speed) of the vehicle. The controller 16 obtains the optimum gear ratio (target gear ratio) of the continuously variable transmission. Then, in order to realize this target gear ratio, the stepping motor 17 is driven based on the control signal of the controller 16 and the gear ratio control valve 22 is switched to thereby change the gear ratio of the toroidal continuously variable transmission 4. The target speed ratio is adjusted to the target speed ratio. In addition, by switching the shift solenoid valve 20 as necessary (according to the target gear ratio of the continuously variable transmission), the connection / disconnection state of the low speed and high speed clutches 7 and 8 is switched. Select the required travel mode (low speed mode or high speed mode). As a result, the gear ratio of the continuously variable transmission is adjusted to an optimum value (target gear ratio) according to the running state of the vehicle at that time.

  Patent Document 3 discloses an automatic transmission mode that automatically adjusts the speed ratio of the continuously variable transmission as described above to the optimum value at that time based on the running state (driving state) of the vehicle. A structure is described in which driving can be performed even in a manual shift mode in which the gear ratio is changed stepwise in accordance with the driver's intention (operation). In the case of the structure described in Patent Document 3, a plurality of preset stages (for example, 5 stages, 5 speeds. Note that the structure is a toroidal continuously variable transmission alone, and is set to 6 stages or 8 stages. Can be changed based on the operation of the driver.

  In the case of such a continuously variable transmission with a manual transmission mode, when the automatic transmission mode is selected, the transmission ratio of the continuously variable transmission is set to an optimal value according to the vehicle conditions such as the vehicle speed and the accelerator opening. Therefore, the controller 16 controls the switching valves 25 and 26 for high speed, low speed, and both clutches to switch the connection / disconnection state of the low speed, high speed, and both clutches 7 and 8, The speed ratio of the toroidal continuously variable transmission 4 is controlled by switching the pressure oil supply / discharge state to the speed ratio control unit 15. In this state, the gear ratio determined by the controller 16 to be appropriate can be realized, the speed change operation by the driver becomes unnecessary, the driver's burden can be reduced, and the driver's driving fatigue can be reduced. On the other hand, in the state where the manual shift mode is selected, the driver can arbitrarily select a gear ratio (shift speed) from among the plurality of preset shift speeds.

  However, when operating in such a manual transmission mode, if the gear ratio of the toroidal type continuously variable transmission, that is, the gear ratio of the continuously variable transmission is adjusted as it is based only on the shift operation of the driver, The following inconveniences may occur. That is, in the manual shift mode, a gear ratio (shift speed) that can be selected by the driver is basically determined. If the driver does not give a gear shift instruction (select lever operation), the gear ratio (shift speed) is determined. Fixed to. However, for example, if the driver decelerates or stops the vehicle while forgetting the downshifting operation with the gear ratio fixed at a high speed, the engine knocks or the engine stops ( There is a possibility that On the other hand, for example, when the traveling speed of the vehicle increases while the driver forgets the upshifting operation with the gear ratio fixed at a low speed, the engine may over-run (overrun).

  In view of such circumstances, a function for automatically changing the gear ratio is provided even when the driver is not operating the manual gear shift mode and the driver does not give an instruction (select lever operation) to change the gear ratio. A continuously variable transmission having the same is conventionally known, for example, as described in Patent Documents 4 and 5. That is, in a continuously variable transmission having a manual transmission mode in addition to the automatic transmission mode, when the driver forgets to perform a shift operation and the vehicle traveling speed fluctuates greatly when the manual transmission mode is selected, the automatic transmission is automatically changed. Structures that perform operations are also known in the art. As such a structure conventionally known, there are three types as shown in the following (A) to (C).

(A) When traveling in manual transmission mode, if the traveling speed is too slow compared to the currently selected transmission ratio, the function to change the speed ratio (increase the reduction ratio) to the lower speed ratio. Give it.
By giving this function to the controller of the continuously variable transmission, it is possible to prevent the engine from being knocked or stalled.
(B) When traveling in manual gear shifting mode, if the traveling speed becomes too fast compared to the gear ratio selected at that time, a function to shift to a higher gear ratio (increase the speed increasing ratio) To have.
By giving this function to the controller of the continuously variable transmission, it is possible to prevent the engine from overrunning.
(C) If the driver suddenly increases the amount of depression of the accelerator pedal while traveling in the manual transmission mode, a function is provided for shifting to a lower speed ratio (increasing the speed reduction ratio).
By giving this function to the controller of the continuously variable transmission, this acceleration can be achieved even if the driver cannot obtain the desired acceleration with the gear ratio at the moment when the accelerator pedal depression amount is increased. Can be obtained.

Any of the conventional structures shown in the above (A) to (C) is a gear shift operation to a preset gear ratio (gear stage) even when the driver forgets an appropriate gear shift operation in the manual gear shift mode. (Shift down or up) is automatically performed. For this reason, there is a problem that the gear ratio automatically changed (selected) is not always appropriate according to the traveling state at that time.
However, in the case of the first and second examples of the conventional structure shown in the above (A) and (B), the gear ratio is changed by one step (first gear) according to the vehicle speed and the engine speed at that time. If the operation (shifting operation, downshifting or upshifting) is repeated, it will not be a big problem. That is, even in the conventional structure shown in the above (A) and (B), when the selected gear ratio deviates significantly from the appropriate value of the gear ratio corresponding to the traveling speed at that time, the gear shifting operation is performed. By performing one step at a time, a problem remains in that it takes a certain amount of time to obtain the optimum acceleration / deceleration. However, in view of the situation where the manual shift mode is also in effect and the driver does not perform a shift operation, it cannot be said that a particularly serious problem occurs.

On the other hand, in the case of the conventional structure shown in the above (C), there is a possibility that the problem cannot be ignored in terms of risk avoidance. In other words, when the driver suddenly increases the amount of depression of the accelerator pedal, it is often necessary to rapidly accelerate immediately after the accelerator pedal is depressed. Therefore, when the driver suddenly increases the amount of depression of the accelerator pedal, immediately after the depression of the accelerator pedal, the gear ratio of the continuously variable transmission is set to the optimum value (a reduction ratio that can achieve the required acceleration state). (It is not desirable to cause a time lag as the speed ratio is set to the optimum value by taking steps).
On the other hand, as in the conventional structure shown in (C) above, when the driver suddenly increases the amount of depression of the accelerator pedal, the gear ratio of the continuously variable transmission can be reduced by simply shifting to the lower speed. The optimum value is not always immediately when the pedal is depressed. For example, when the controller detects a sudden increase in the amount of depression of the accelerator pedal and performs a shift operation of “current shift speed—1st speed”, the gear ratio after the shift operation is still biased toward the high speed side. There is a possibility that sufficient acceleration cannot be obtained at the vehicle speed at that time, or if the vehicle is going uphill, the vehicle is decelerated, and if it is significant, the engine may be knocked. In order to prevent such an inconvenience, when the controller performs a shift operation of “current shift stage-2 speed” when detecting a sudden increase in the amount of depression of the accelerator pedal, the gear ratio after the shift operation is If the vehicle speed at that time becomes excessively high, the acceleration becomes excessive, or the rotational speed of the engine rapidly increases.

  In view of the circumstances as described above, the present invention has been invented to realize a structure capable of obtaining an acceleration force necessary for avoiding danger even when traveling in a state where the manual transmission mode is selected.

In the continuously variable transmission according to the present invention, the controller for adjusting the speed ratio between the input shaft and the output shaft is set to any one of a plurality of speed values that are different from each other. A manual shift function that adjusts based on the shift operation of the driver, and an automatic shift function that automatically adjusts the gear ratio according to the driving state at that time, not based on the shift operation of the driver .
In particular, in the continuously variable transmission according to the present invention, the controller selects any one of the plurality of gears based on a gear shift operation by the driver, and shifts corresponding to the gears. Even if the driver does not change the gear ratio to the deceleration side based on the manual gear shifting function when the accelerator pedal depression amount suddenly increases while the ratio is adjusted, the vehicle speed and the accelerator It has a function of automatically adjusting to a gear ratio determined to be optimal according to the amount of pedal depression.

Preferably, when the invention of the continuously variable transmission according to the present invention as described above is carried out, as in the invention described in claim 2, the controller is provided with a vehicle speed and a depression amount of the accelerator pedal at that time. If the accelerator pedal continues to be depressed even after it is automatically adjusted to the optimum gear ratio, the gear ratio is optimized according to the vehicle speed at each time and the amount of depression of the accelerator pedal. The function to keep adjusting to the value judged to be.
When carrying out the invention described in claim 2 as described above, for example, as in the invention described in claim 3, the value of the gear ratio determined to be optimum at that time, the engine speed, and the A value that can be maintained at an optimum rotational speed corresponding to the vehicle speed at the time.
Note that the value of the gear ratio that can be maintained at the optimum rotational speed corresponding to the vehicle speed is any value selected from the following (a) to (c).
(a) The value at which the engine speed is the speed at which the maximum torque is generated at the current vehicle speed.
(b) Value at which the engine speed is the speed at which the maximum horsepower is generated at the current vehicle speed.
(c) Designed in consideration of the vehicle speed at that time and the above (a) and (b), a value that gives the optimum engine speed {as an intermediate value between these (a) and (b) Defined tuning value}.

  Further, when the present invention is implemented, preferably, as in the invention described in claim 4, the controller has a vehicle speed and a depression of the accelerator pedal at the time when the depression amount of the accelerator pedal suddenly increases. After automatically adjusting to the gear ratio determined to be optimal according to the amount, when the amount of depression of the accelerator pedal decreases, the function of automatically adjusting the gear ratio is released. Then, the controller is provided with a function of returning to the state in which the speed ratio is adjusted by the manual speed change function before the speed ratio is automatically adjusted to the deceleration side based on this function.

  When carrying out the present invention, preferably, as in the invention described in claim 5, as the accelerator pedal depressing amount suddenly increases, the controller determines the vehicle speed and the accelerator pedal depressing amount at that time. Automatically adjusts to the gear ratio determined to be optimal according to the vehicle's speed, and the accelerator pedal depression amount is maintained as it is and continues to be adjusted to the gear ratio determined to be optimal according to the vehicle speed at that time. As a result, when the speed ratio before the start of automatically adjusting the speed ratio is reached, the function of automatically adjusting the speed ratio is released. Based on this function, a function of returning to a state in which the gear ratio is adjusted by the manual gear shifting function before the gear ratio is automatically adjusted to the deceleration side is provided.

When carrying out the present invention, whether or not a kick-down operation has been performed (whether or not the amount of depression of the accelerator pedal has suddenly increased under circumstances where it is necessary to change the gear ratio to the deceleration side, As a method for determining whether or not the F-KICKDN flag is turned on in step 8 in FIG. 3 showing a flowchart showing the operation of the embodiment described later, any of the following (a) to (d) Can be used.
(a) Judgment is made based on whether or not the accelerator pedal depression amount has suddenly changed.
For example, the depression speed of the accelerator pedal is “1% / 10 ms or more” and the depression amount of the accelerator pedal is 80% or more (80% of the total stroke from the state where the pedal is not depressed to the state where it is completely depressed) If it has been depressed), it is determined that a kick-down operation has been performed.
(b) A kick-down switch (ON / OFF switch) provided in the back of the accelerator pedal, which is turned on when the accelerator pedal is fully depressed, detects that the accelerator pedal has been completely depressed. In this case, it is determined that a kick down operation has been performed.
(c) When it is detected that the amount of depression of the accelerator pedal changes suddenly and the accelerator pedal is fully depressed by the kick down switch, it is determined that the kick down operation has been performed.
For example, when the depression speed of the accelerator pedal is “1% / 10 ms or more” and the kick down switch is turned on, it is determined that the kick down operation has been performed.
(d) When it is determined that the vehicle speed is a predetermined value V1 (for example, V1 = 30 km / h) and the accelerator pedal depresses rapidly in the above-described (a) to (c) Only when it is determined that the kick-down operation has been performed.
In any case, the vehicle speed at that time is not limited to the characteristic control of the present invention while the vehicle is stopped, and the speed ratio of the continuously variable transmission is set to 1st speed (the speed reduction ratio is the maximum). When the engine speed is equal to or higher than the maximum torque or the maximum rotation speed (or allowable maximum number of rotations) at which the maximum horsepower is generated, the control characteristic of the present invention is not performed.

Further, after determining that the kick-down operation has been performed by any of the methods described in the above (a) to (d), the predetermined condition is satisfied as in the inventions described in claims 4 and 5 above. In this case, the method for determining whether to return to the state in which the gear ratio is adjusted by the manual transmission function (cancel the determination that the kick-down operation has been performed and turn off the F-KICKDN flag) is as follows: Any method of a) to (d) can be adopted.
(a) Determine whether the accelerator pedal is released.
For example, when the accelerator pedal stepping-on state that has been greatly depressed changes in the release direction and the accelerator pedal depression amount is 50% or less (the pedal has not been depressed more than 50% of the total stroke), Releases the determination that a kick-down operation has been performed.
(b) When the kick down switch is turned off, the determination that the kick down operation has been performed is cancelled.
(c) When the kick-down switch is turned off and the accelerator pedal depression amount is 50% or less, the determination that the kick-down operation has been performed is cancelled.
(d) The speed ratio of the continuously variable transmission is automatically adjusted based on the determination that the kick-down operation has been performed. As a result, the current speed ratio is selected based on the original speed ratio (the manual speed change mode was selected). When the gear ratio is restored, the determination that the kick-down operation has been performed is cancelled.

According to the continuously variable transmission of the present invention configured as described above, it is possible to realize a structure capable of obtaining an acceleration force necessary for danger avoidance or the like even when traveling in a state where the manual transmission mode is selected.
That is, in the case of the continuously variable transmission according to the present invention, the manual transmission mode is selected as the transmission mode of the continuously variable transmission, and the transmission ratio of the continuously variable transmission is set to a specific value (gear, for example, 5th speed). ) If the driver suddenly increases the amount of depression of the accelerator pedal (acceleration operation by kick-down has been performed) while driving in a fixed state, the controller simply shifts the gear position ( Speed ratio-1st speed "or" current speed-2nd speed ", but not the optimum speed ratio (for example, the engine speed is the maximum torque) according to the vehicle speed at that time Alternatively, automatic downshift control is performed to a speed ratio that provides a rotational speed that generates maximum horsepower. For this reason, even when the driver has greatly depressed the accelerator pedal while forgetting the downshifting operation, an optimal acceleration state can be realized that the driver thinks necessary at that time. That is, for example, when sudden acceleration is required temporarily to avoid danger, the driver can achieve the required acceleration state by simply depressing the accelerator pedal without performing a shift operation. The acceleration state for avoiding danger like this can be realized.

Further, in the case of the continuously variable transmission according to the present invention, when the driver keeps the accelerator pedal depressed greatly (continues to accelerate), the controller obtains as described above. In order to maintain the optimum acceleration state (for example, the speed ratio capable of maintaining the engine speed at the maximum speed or the speed that generates the maximum horsepower), the speed ratio of the continuously variable transmission as the vehicle speed increases, Adjust to the speed increasing side.
As a result, the speed ratio of the continuously variable transmission is changed (shifted up) until it reaches the same value as the original speed ratio (speed stage), which is the speed ratio selected in the manual speed change mode. In this case, the shift control based on the determination that the kick-down operation, which is a feature of the present invention, is completed, and thereafter the original gear ratio (fixed gear stage) is maintained.
For this reason, for example, when accelerating for a relatively long time, such as when joining a highway, even if the driver forgets the manual downshift operation, the required acceleration is After realizing the required acceleration, the driver's intended driving situation can be determined based on the gear ratio selected by the driver first. You can resume.

On the other hand, if the driver depresses the accelerator pedal greatly and then returns the accelerator pedal, the driver wishes for a temporary (short-term) acceleration, and it is determined that the desire has already been achieved. Then, it is determined that the acceleration by the kick-down is completed, and the original gear ratio (shift speed) is restored.
For this reason, even when temporary acceleration is performed, thereafter, the driving situation intended by the driver can be maintained based on the gear ratio selected by the driver. That is, even when sudden acceleration is required temporarily, for example, in order to avoid danger, the driver forgets the manual downshifting operation as in the case where acceleration is required for a relatively long time as described above. However, the required acceleration can be obtained without causing a problem time delay, and after realizing the required acceleration, based on the gear ratio selected by the driver first, The driving situation intended by the driver can be resumed.

As described above, the continuously variable transmission according to the present invention has a vehicle speed at that time even when the driver forgets to perform a shift operation for downshifting and depresses only the accelerator pedal while traveling in the manual shift mode. It is possible to obtain the necessary acceleration performance without causing a time delay which causes a problem by automatically shifting down to the optimum gear ratio according to the vehicle.
In other words, despite the fact that the accelerator pedal is fully depressed, the required acceleration performance cannot be obtained or the required acceleration performance is obtained as the gear ratio of the continuously variable transmission remains unchanged. There is no time lag until the driver feels uncomfortable. As a result, the driver feels uneasy due to the time delay until the driver feels the desired acceleration after the accelerator pedal is fully depressed (especially the acceleration required to avoid danger). Etc.) can be suppressed.

The block diagram of a continuously variable transmission for demonstrating one example of embodiment of this invention. The figure which shows an example of the hydraulic circuit for gear ratio control. The flowchart for demonstrating the operation | movement of gear ratio control. The figure which shows an example of the map used when adjusting a gear ratio in automatic transmission mode. The diagram for demonstrating the operation | movement of gear ratio control. The block diagram which shows one example of the continuously variable transmission conventionally known. The figure which similarly shows the hydraulic circuit for gear ratio control. The diagram which shows the relationship between the speed ratio of the whole continuously variable transmission, and the speed ratio of the toroidal type continuously variable transmission incorporated in this continuously variable transmission.

  In the continuously variable transmission of this example, as shown in FIG. 1, in addition to signals similar to those in the conventional structure described above, such as signals from the position switch 37 and the accelerator sensor 34, the controller 16 for gear ratio control is added. Thus, signals from the shift sensor 35 and the acceleration sensor 36 are input. The position switch 37 detects the position (forward, reverse, neutral, parking) of the shift lever selected by the manual hydraulic pressure switching valve 32a shown in FIG. The shift sensor 35 is provided with a paddle shift lever or the like when the manual shift mode (M position in the manual hydraulic pressure switching valve 32a in FIG. 2) is selected by the manual hydraulic pressure switching valve 32a. This is for detecting which gear ratio (speed) is selected by the gear ratio switching device for manual gear shifting. The accelerator sensor 34 detects the amount of depression of the accelerator pedal, and the acceleration sensor 36 detects the acceleration of the vehicle (vehicle body).

  The continuously variable transmission of this example employs a configuration as shown in FIGS. 1 and 2 and appropriately adjusts the speed ratio between the input shaft 3 and the output shaft 9. That is, when the driver selects the automatic transmission mode (the D position in the manual hydraulic pressure switching valve 32a of FIG. 2) by the manual hydraulic pressure switching valve 32a, Similarly, the gear ratio of the continuously variable transmission is adjusted to an optimum value according to the vehicle situation such as the vehicle speed and the accelerator opening. That is, in this case, the controller 16 controls the switching valves 25 and 26 for high speed, low speed, and both clutches shown in FIG. In addition to switching the contact state, the speed ratio of the toroidal continuously variable transmission 4 is controlled by switching the pressure oil supply / discharge state to the speed ratio control unit 15a. In this state, the speed ratio determined by the controller 16 to be appropriate can be realized, the speed change operation by the driver becomes unnecessary, the driver's burden can be reduced, and the driver's fatigue can be reduced. On the other hand, in the state in which the manual transmission mode is selected, the transmission ratio switching device allows the driver to arbitrarily select a transmission ratio (shift stage) from among a plurality of preset transmission stages. .

  About the above structure and effect | action, it is the same as that of the case of the continuously variable transmission widely known conventionally. In particular, in the case of the continuously variable transmission of the present invention, the accelerator pedal is increased without operating the transmission ratio switching device in a state where the driver selects the manual transmission mode with the manual hydraulic pressure switching valve 32a. When stepped on, the speed ratio of the continuously variable transmission is adjusted to the deceleration side so that the required acceleration performance can be obtained without causing a time delay that is a problem. That is, when the accelerator sensor 34 detects that the accelerator pedal has been depressed greatly, even in the manual shift mode, the gear ratio of the continuously variable transmission is temporarily determined at that time. The vehicle speed is adjusted to an optimum value (not the fixed speed ratio set in advance in the manual speed change mode, but the optimum speed ratio according to the vehicle speed at that time). Even when the driver forgets the downshift operation, the acceleration performance intended for the driver can be obtained so that the acceleration performance intended by the driver can be obtained. Hereinafter, the operation of the continuously variable transmission of this example including such a characteristic portion will be described with reference to FIGS.

  First, in step 1 shown in FIG. 3, the current (current) shift mode is determined. If it is determined in step 1 that the current speed change mode is the automatic speed change mode, the process proceeds to step 2, and based on a map as shown in FIG. Accordingly, the gear ratio is automatically adjusted to an appropriate gear ratio.

  On the other hand, if it is determined in step 1 that the current shift mode is the manual shift mode, the process proceeds to step 3 to detect the vehicle speed at that time. Specifically, the vehicle speed at that time is assumed to be adjusted to the first gear (the gear ratio that can be realized when the continuously variable transmission is adjusted to the slowest speed side). It is determined whether or not the vehicle speed is less than or equal to the vehicle speed X1 (for example, 30 km / h) when it is assumed that the maximum allowable rotational speed is increased (and whether or not the vehicle is stopped). If it is determined in step 3 that the vehicle speed V is equal to or less than the threshold value X1 (and the vehicle is in a stopped state), the process proceeds to step 4 to generate an optimal creep force while the vehicle is in a stopped state. Control (stop GN control) is performed or when the vehicle is in a running state, the gear ratio is fixed to the first speed.

  On the other hand, if it is determined in step 3 that the vehicle speed V exceeds the threshold value X1 (V> X1), it is determined in next step 5 whether or not there is a shift request from the driver. That is, it is determined whether or not the driver has operated the gear ratio switching device such as a paddle shift lever. If it is determined in step 5 that there is a gear change request by the driver, the gear ratio of the continuously variable transmission is requested in step 6 in response to the gear change request. Change to a value. If the kick-down shift control flag (F-KICKDN flag) indicating that the accelerator pedal has been depressed greatly (becomes kick-down state) is turned on, this flag is turned off.

  On the other hand, if it is determined in step 5 that there is no shift request from the driver, it is determined in step 7 whether or not gear ratio control (kick-down shift control) based on an increase in accelerator pedal depression amount is in progress { The kickdown shift control flag (F-KICKDN) ON / OFF state} is determined. If it is determined in step 7 that F-KICKDN is OFF, the process proceeds to the next step 8 to determine the depression state of the accelerator pedal.

If it is determined in step 8 that the accelerator pedal is depressed suddenly (as described above for the determination criteria), the kick-down shift control flag (F-KICKDN) is turned on in step 9. In step 10, kickdown shift control, which is a feature of this example, is performed. For example, as shown in FIG. 5, a case will be described in which the amount of depression of the accelerator pedal is suddenly increased at point a while the fifth gear is selected in the manual shift mode and the vehicle is traveling. In this case, based on the kick-down shift control, which is a feature of the present invention, the speed ratio of the continuously variable transmission is a value at which a necessary and sufficient acceleration performance can be obtained at that time, as indicated by the point B. For example, the engine speed is adjusted to a gear ratio of 6000 min ⁻¹ that exhibits the maximum torque. In the case of merely shifting the shift speed ("current shift speed-1 speed" or "current shift speed-2 speed") as in the conventional structure described above, FIG. As indicated by point C, the engine speed is insufficient and sufficient acceleration performance cannot be obtained (in the case of “current shift speed-1 speed”), or as indicated by point D in FIG. Furthermore, there is a possibility that the engine will overrun (in the case of “current shift speed-2 speed”). On the other hand, if the present invention is implemented, the speed ratio of the continuously variable transmission becomes an optimum value necessary to obtain a desired acceleration performance.
On the other hand, if it is determined in step 8 that the amount of depression of the accelerator pedal has not increased abruptly, the process is terminated while maintaining the gear ratio (gear stage) at that time, and the process returns to step 1.

  If it is determined in step 7 that F-KICKDN is ON, the process proceeds to the next step 11 to determine whether the accelerator pedal is released. If it is determined in step 11 that the accelerator pedal has been returned, the process proceeds to the next step 12 where the kick down shift control flag (F-KICKDN) is turned OFF and the kick down, which is a feature of the present invention. After canceling the shift control, the routine proceeds to step 13 where a shift-up shift to the original gear ratio (shift stage) is performed. At this time, the gear ratio of the continuously variable transmission shifts from point (e) to point (f) in FIG. Note that the criteria for determining the accelerator pedal release state are as described above.

Further, if the accelerator pedal is not fully returned in the step 11, the subsequent gear ratio (the gear ratio to be changed automatically and continuously) and the original (the gear ratio) are determined in the following step 14. A comparison is made with the gear ratio before the sudden increase in the amount of depression of the accelerator pedal, which is selected based on the operation of the switching device. Then, when the current gear ratio coincides with the original gear ratio, the routine proceeds to the step 12, and the kick-down gear shift control flag (F-KICKDN) is turned OFF to cancel the kick-down gear shift control which is a feature of the present invention. Then, the process proceeds to step 13 and is fixed to the original speed ratio (speed stage). At this time, the gear ratio of the continuously variable transmission shifts from point B to point G in FIG.
On the other hand, in step 14, the current speed ratio does not match the original speed ratio (current speed ratio ≠ original speed ratio, more specifically, the current speed ratio is on the deceleration side with respect to the original speed ratio). If it is determined that the vehicle is biased), the process proceeds to step 15 where the speed is adjusted to the optimum gear ratio according to the vehicle speed and the accelerator opening at that time (the engine rotates appropriately to obtain the required acceleration performance). The gear ratio of the continuously variable transmission is adjusted so that the speed is reached.

The above operation is repeated during the state in which the manual shift mode is selected by the manual hydraulic pressure switching valve 32a. For this reason, even if the driver forgets the gear shift operation (shift down gear shift command by the paddle shift lever, etc.) when sudden acceleration is required temporarily to avoid danger, etc., it is necessary even if only the accelerator pedal is operated. Acceleration performance can be obtained without causing a time delay that makes the driver feel uncomfortable.
Furthermore, in the state after obtaining the required acceleration performance, it is automatically restored to the original gear ratio (shift stage) previously selected by the driver according to the accelerator pedal depression status, vehicle speed, etc. Therefore, after realizing the required acceleration, the driving situation intended by the driver can be resumed and further continued based on the speed ratio selected by the driver. That is, according to the present invention, after appropriately performing the danger avoidance operation based on the temporary kick-down control, the structure for maintaining the original gear ratio selected by the driver is used in the case of emergency evacuation. A manual shift mode based on the driver's will can be realized in a wide range while appropriately performing the control.

The present invention combines a toroidal-type continuously variable transmission, a planetary gear type transmission, and a clutch device so that the rotation direction of the output shaft is sandwiched between the stop state while the input shaft is rotated in one direction in the low speed mode state. In addition to the so-called geared-neutral type continuously variable transmission that can be converted, various continuously variable transmissions having other structures as shown in the following (A) to (C) can also be implemented.
(A) A toroidal continuously variable transmission, planetary gear type transmission and clutch device are combined to transmit power in the toroidal continuously variable transmission in the low speed mode, and toroidal continuously variable in the high speed mode. A so-called power split type continuously variable transmission that reduces torque passing through the toroidal continuously variable transmission by transmitting power through the transmission and the planetary gear type transmission.
(B) A continuously variable transmission constructed only of a toroidal type continuously variable transmission without using a planetary gear type transmission.
(C) A belt-type continuously variable transmission in which a belt is stretched between a pair of pulleys each capable of expanding and reducing the width dimension.

DESCRIPTION OF SYMBOLS 1 Engine 2 Damper 3 Input shaft 4 Toroidal type continuously variable transmission 5 Planetary gear type transmission 6 Clutch device 7 Low speed clutch 8 High speed clutch 9 Output shaft 10 Input side disk 11 Output side disk 12 Power roller 13 Actuator 14 Press device 15, 15a Gear ratio control unit 16 Controller 17 Stepping motor 18 Electromagnetic on-off valve for line pressure control 19 Gear valve for correcting gear ratio 20 Solenoid valve for shift 21 Control valve device 22 Gear ratio control valve 23 Differential pressure cylinder 24a, 24b Correction Control valve 25 Switching valve for high speed clutch 26 Switching valve for low speed clutch 27, 27a, 27b Oil supply pump 28 Oil reservoir 29 Push pressure adjustment valve 30 Low pressure side adjustment valve 31a, 31b Hydraulic chamber 32, 32a Manual hydraulic pressure change valve 33 Pressure reducing valve 34 Accelerator sensor 35 Shift sensor 36 Speed sensor 37 position switch

Japanese Patent Laid-Open No. 10-196759 JP 2006-349159 A JP 2000-193077 A JP-A-9-310757 JP 2004-125071 A

Claims (5)

  A controller for adjusting the speed ratio between the input shaft and the output shaft is adjusted based on the speed change operation of the driver to one of a plurality of values that are different from each other. A continuously variable transmission having a manual transmission function and an automatic transmission function that automatically adjusts a gear ratio according to a driving state at that time without being based on a gear shifting operation of a driver; Depressing amount of the accelerator pedal in a state in which any one of the plurality of gears is selected and adjusted to a gear ratio corresponding to the gears based on a gear shift operation by the driver. Even if the driver does not change the gear ratio to the deceleration side based on the manual gear shifting function, the gear shift determined to be optimum according to the vehicle speed and the amount of depression of the accelerator pedal at that time To automatically adjust the ratio Continuously variable transmission that is characterized in that.   When the accelerator pedal is continuously depressed even after the controller automatically adjusts to the gear ratio determined to be optimal according to the vehicle speed at that time and the depression amount of the accelerator pedal, 2. The continuously variable transmission according to claim 1, having a function of continuously adjusting to a value determined to be optimal according to a vehicle speed at the time point and a depression amount of the accelerator pedal.   The continuously variable transmission according to claim 2, wherein the value of the transmission gear ratio determined to be optimal at that time is a value capable of maintaining the rotation speed of the engine at an optimal rotation speed corresponding to the vehicle speed at that time.   The controller automatically adjusts to the gear ratio determined to be optimal according to the current vehicle speed and the amount of depression of the accelerator pedal as the amount of depression of the accelerator pedal suddenly increases. When the amount decreases, the function to automatically adjust the gear ratio is released, and the gear ratio is adjusted by the manual gearshift function before the gear ratio is automatically adjusted to the deceleration side based on this function. The continuously variable transmission according to any one of claims 1 to 3, wherein the continuously variable transmission has a function of returning to the position.   The controller automatically adjusts to the gear ratio determined to be optimal according to the current vehicle speed and the amount of depression of the accelerator pedal as the amount of depression of the accelerator pedal suddenly increases. When the amount is maintained as it is and the gear ratio that is determined to be optimum corresponding to the vehicle speed at that time is continuously adjusted, as a result of reaching the gear ratio before this gear ratio is automatically adjusted, The function of automatically adjusting the speed ratio is canceled, and the function of returning the speed ratio to the state adjusted by the manual speed change function before the speed ratio is automatically adjusted to the deceleration side based on the function. The continuously variable transmission according to any one of claims 1 to 4.

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