JP2007032767A - Gear ratio controller for continuously variable transmission for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a vehicle to run at a vehicle speed being suitable for road situation by adjusting the gear ratio of a continuously variable transmission to the optimum value and setting braking force based on engine brake to a proper value in accordance with the road situation. <P>SOLUTION: The control for adjusting the gear ratio to a deceleration side in a condition in which the vehicle runs while stepping on a brake pedal is performed. At this time, amount of adjustment of the gear ratio is changed in accordance with force for stepping on the brake pedal, and speed of speed change is changed in accordance with stepping-on speed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement in a control device for controlling a gear ratio of a continuously variable transmission used as an automatic transmission for a vehicle (mainly automobile) such as a belt type continuously variable transmission or a toroidal type continuously variable transmission. Specifically, the driver's intention to decelerate is quickly reflected in the adjustment of the gear ratio, thereby facilitating the realization of a stable traveling state along the traffic flow.

  In recent years, a continuously variable transmission such as a belt type continuously variable transmission or a toroidal type continuously variable transmission is increasingly used as an automatic transmission for vehicles. A continuously variable transmission can effectively improve engine performance and improve fuel efficiency and driving performance, but in order to obtain its advantages and ensure driving safety, it can It is necessary to perform control for realizing the optimum gear ratio. Further, when the driver removes his / her foot from the accelerator pedal, it is necessary to control the gear ratio of the continuously variable transmission in order to obtain an appropriate deceleration (braking force) according to the running state by the engine brake. .

  Conventionally, the operation of an accelerator pedal or the like is detected, and the gear ratio is changed to the deceleration side in accordance with the vehicle condition (vehicle speed or deceleration) at that time. However, if the vehicle is a gear-type vehicle having a stepped transmission mechanism (a vehicle in which the gear ratio during traveling cannot be adjusted steplessly), for example, when traveling downhill, the road conditions at that time (degree of gradient, There are few cases where the braking force by the engine brake is just an appropriate value depending on whether there is a curve, the radius of curvature of the curve, the presence or absence of traffic jams, the road width, etc. This is because the braking force by the engine brake determined by the transmission gear ratio changes only in stages. Specifically, at the selected gear ratio, the braking force by the engine brake is often too strong or conversely too weak.

  On the other hand, in the case of a continuously variable transmission, the gear ratio can be adjusted steplessly. Therefore, if appropriate control is performed, the braking force by the engine brake can be just set to an appropriate value. As conventional techniques for adjusting the gear ratio of the continuously variable transmission according to the running state, for example, those described in Patent Documents 1 to 4 are known. In the case of the prior art described in each of these patent documents, the deceleration caused by the engine brake is changed according to the vehicle speed when the driver stops the depression of the accelerator pedal and travels by inertia.

  That is, in the case of the prior art described in each of the above patent documents, the braking force based on the required engine brake is calculated based on the accelerator pedal depression state, acceleration, vehicle speed, etc. The gear ratio is controlled. Specifically, for example, during high-speed driving, the speed is increased in order to increase the braking force based on the engine brake, and during low-speed driving, the speed reduction is performed to decrease the braking force based on the engine brake. Shift in a direction to reduce the ratio. However, depending on the state of the accelerator pedal depression, acceleration, and vehicle speed, the appropriate engine brake will be applied depending on the road conditions (gradient level, presence / absence of curves, radius of curvature of curves, presence / absence of traffic jams, road width, etc.). It is difficult to finely adjust the gear ratio in order to obtain the braking force by. Furthermore, the intention of the driver (whether destined for deceleration or acceleration) cannot be incorporated into the control for adjusting the gear ratio.

  For this reason, depending on the road conditions, the gear ratio is not adjusted to an appropriate value even though it is a continuously variable transmission, and there is a possibility that stable running is hindered. For example, when the gear ratio is biased toward the deceleration side with respect to an appropriate value corresponding to the road condition, the braking force based on the engine brake is too strong and the vehicle speed is excessively reduced. As a result, it not only causes traffic jams, but also has a risk of being collided with a succeeding vehicle when the vehicle speed is extremely reduced. Further, in order to prevent the occurrence of traffic jams and rear-end collisions, it is necessary to depress the accelerator pedal that has been depressed until then in order to prevent the vehicle speed from excessively decreasing. Originally, if an appropriate speed ratio is set, it is difficult to obtain an appropriate vehicle speed by depressing the accelerator pedal, and it is difficult to obtain an appropriate vehicle speed only by the braking force based on the engine brake. Will occur, and stable driving will not be possible (the driving condition will be jerky).

  On the contrary, when the adjusted gear ratio is biased toward the speed increase side with respect to an appropriate value corresponding to the road condition, the braking force based on the engine brake is too weak and the vehicle speed increases excessively. As a result, the number of times the brake pedal is depressed and the time increase, the burden on the driver required to travel at the optimum vehicle speed increases, and the driver's fatigue increases. In addition, if the number of times and the time of depression of the brake pedal are extremely increased, the temperature of the brake may be excessively increased and the braking force may be decreased. As a continuously variable transmission that is preferable as an object of the present invention, the input shaft is rotated by combining, for example, a toroidal continuously variable transmission mechanism and a gear-type differential mechanism described in Patent Document 5. A structure in which the output shaft can be stopped in a state is known.

JP-A-8-334156 JP-A-9-112680 JP-A-9-112682 JP-A-9-112682 JP 2004-211836 A

In view of the circumstances as described above, the present invention optimizes the transmission ratio of the continuously variable transmission according to the road conditions at that time, such as the degree of gradient, the presence or absence of a curve, the radius of curvature thereof, the presence or absence of traffic congestion, and the road width. Adjusting and adjusting the braking force based on engine braking to an appropriate value to enable traveling at a vehicle speed suitable for the above road conditions, thereby enabling safe and stable traveling conditions such as downhills. It was invented to realize a control device for a machine.
Specifically, based on not only the accelerator pedal depression status but also the brake pedal depression status and changes in running speed, the driver's intention to drive in the current state is estimated and the above-mentioned continuously variable transmission is performed. The speed ratio of the machine is adjusted to a value that is considered appropriate according to the estimated intention, and traveling at a vehicle speed suitable for the road condition is enabled.

A control device for a continuously variable transmission for a vehicle according to the present invention includes a continuously variable transmission, a controller for adjusting the transmission ratio of the continuously variable transmission, and a speed detecting means for detecting the traveling speed of the vehicle. And a brake operation state detecting means for detecting the operation state of the brake pedal.
Then, the controller determines that the brake pedal of the brake pedal is detected when the vehicle speed is determined by the travel speed detection means and the brake pedal is operated by the brake operation state detection means. It has a function of adjusting the gear ratio of the continuously variable transmission according to the operating state.

  The control device for a continuously variable transmission for a vehicle according to the present invention configured as described above estimates an intention of how the driver is going to travel by observing the operation state of the brake pedal. Then, in order to adjust the transmission ratio of the continuously variable transmission to a value that is considered appropriate according to the estimated intention, the braking force based on the engine brake is secured to a vehicle speed that is suitable for road conditions and the driver's intention. Therefore, it can be sized appropriately. As a result, it is possible to travel at an appropriate vehicle speed without frequently repeating the operation of the accelerator pedal and the brake pedal, thereby reducing driver fatigue and preventing occurrence of traffic jams and rear-end collisions.

When implementing the present invention, preferably, as described in claim 2, the controller obtains a target gear ratio of the continuously variable transmission based on the operation state of the brake pedal detected by the brake operation state detection means, A function of adjusting the speed ratio of the continuously variable transmission to the target speed ratio is provided.
If comprised in this way, a driver | operator's will will be rapidly reflected in the gear ratio of a continuously variable transmission according to the operation condition of a brake pedal, and the stable driving | running | working state can be implement | achieved.
In the case of carrying out the invention described in claim 2, preferably, as described in claim 3, when it is determined that the brake pedal is operated, the speed ratio of the continuously variable transmission is reduced. Adjust to.
With this configuration, the driver's intention to decelerate the vehicle, expressed by operating the brake pedal, is reflected in the gear ratio of the continuously variable transmission, while suppressing the driver's burden. A stable running state can be realized.

Further, when the invention described in claim 3 as described above is carried out, for example, as described in claim 4, for example, the brake operation state detecting means is provided with a function for obtaining the depression speed of the brake pedal. Then, the controller has a function of increasing the speed at which the gear ratio is adjusted to the deceleration side as the stepping speed increases.
Alternatively, as described in claim 5, the brake operation state detection means is provided with a function for obtaining the depression force of the brake pedal. Then, the controller is provided with a function of increasing the degree of adjusting the speed ratio to the deceleration side (speed ratio adjustment range) as the stepping force increases.
If comprised in this way, depending on the operation state of a brake pedal, not only will a driver | operator intend to decelerate, but it will draw up to the extent to decelerate and can adjust the gear ratio of a continuously variable transmission. For this reason, the stable driving | running | working state is realizable, suppressing a driver | operator's burden more.

Further, when the inventions described in claims 3 to 5 as described above are carried out, preferably, as described in claim 6, for example, the operation of the brake pedal is terminated by the brake operation state detection means in the controller. If the speed ratio of the continuously variable transmission is determined, the operation has been completed until the next state where the speed ratio should be adjusted, such as re-operation of the brake pedal or depression of the accelerator pedal. A function of maintaining the gear ratio at the determined time is provided.
Alternatively, as described in claim 7, when the controller determines that the operation of the brake pedal has been completed by the brake operation state detection means, the speed ratio of the continuously variable transmission is changed to Unless a state where the gear ratio should be adjusted next appears, such as when the accelerator pedal is depressed, gradually from the gear ratio at the time when it is determined that the operation is completed to the gear ratio immediately before the brake pedal is operated ( It has a function of returning (for example, taking 1 to several seconds).
Alternatively, as described in claim 8, an accelerator operation state detection means for detecting the depression state of the accelerator pedal is provided. When the controller determines that the operation of the brake pedal has been completed by the brake operation state detection means, the speed ratio of the continuously variable transmission is determined from the traveling speed at that time and the depression state of the accelerator pedal. A function of gradually changing the required speed change ratio (for example, taking 1 to several seconds) is provided.
If such a configuration is adopted, after releasing the brake pedal that the driver has stepped on (operated) for deceleration, the gear ratio of the continuously variable transmission is set to an appropriate value, and the vehicle The running state can be stabilized. Of the above-described claims 6 to 8, which of the inventions shown in claims 6 and 7 is to be implemented can be selected according to the traveling speed of the vehicle. For example, it is conceivable to implement the invention described in claim 6 when traveling at a low speed of 10 km / h (or 5 km / h) or less, and the invention described in claim 7 otherwise.

Preferably, when carrying out the present invention, preferably, the continuously variable transmission is a half-toroidal or full-toroidal continuously variable transmission mechanism and a gear type such as a planetary gear mechanism. And a differential transmission mechanism capable of realizing a so-called infinite gear ratio in which the output shaft is stopped while the input shaft is rotated.
The toroidal-type continuously variable transmission has a speed change operation faster than a belt-type continuously variable transmission and can quickly realize a deceleration state according to the driver's intention. Therefore, it is more advantageous than the belt type continuously variable transmission. In addition, in the case of a structure capable of realizing the infinite gear ratio, an extremely low speed driving state can be realized. Therefore, for example, by carrying out in combination with the invention described in claim 6, the foot from the brake pedal can be used in a traffic jam. This is advantageous in terms of reducing the burden on the driver, such as being able to travel at a low speed in a separated state.

  1 to 8 show an embodiment of the present invention. Of these, FIG. 1 shows that the input shaft 3 is rotated and output by combining a toroidal-type continuously variable transmission mechanism and a gear-type differential mechanism as described in Patent Document 5 described above. The block diagram of the continuously variable transmission which can implement | achieve what is called an infinite gear ratio which can stop the axis | shaft 14 is shown. In the case of the present embodiment, the speed ratio of such a continuously variable transmission is configured to be adjusted according to the operating state of the brake pedal. In FIG. 1, a thick arrow indicates a power transmission path, a solid line indicates a hydraulic circuit, and a broken line indicates an electric circuit. 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 from the hydraulic pressing device 5 constituting the toroidal-type continuously variable transmission 4 to the input side disk 6 and further to the output side disk 8 via the power roller 7. The

  Of these two discs 6, 8, the rotational speed of the input side disc 6 is measured by the input side rotational sensor 9, and the rotational speed of the output side disc 8 is measured by the output side rotational sensor 10, and is input to the controller 11. The gear ratio (speed ratio) between the disks 6 and 8 (of the toroidal-type continuously variable transmission 4) can be calculated. The power transmitted to the input shaft 3 is transmitted to the planetary gear mechanism 12 which is a differential unit directly or via the toroidal continuously variable transmission 4. Then, the differential component of the constituent members of the planetary gear mechanism 12 is extracted to the output shaft 14 via the clutch device 13. The clutch device 13 represents a low speed clutch 15 and a high speed clutch 16 shown in FIG. Further, the rotation speed of the output shaft 14 can be detected by the output shaft rotation sensor 17.

  On the other hand, the oil pump 18 (18a, 18b in FIG. 2) is driven by the power extracted from the damper 2 portion, and the pressure oil discharged from the oil pump 18 supports the pressing device 5 and the power roller 7. The trunnion, which is a support member, can be fed into a control valve device 20 for controlling the amount of displacement of an actuator 19 (see FIG. 2) that displaces the trunnion in the axial direction of a pivot (not shown). The control valve device 20 includes a gear ratio control valve 21, a differential pressure cylinder 22, correction control valves 23a and 23b, a high-speed switching valve 24, and a low-speed switching valve 25 shown in FIG. Are combined. Of these, the transmission ratio control valve 21 controls the supply and discharge of hydraulic pressure to the actuator 19. The hydraulic pressure in a pair of hydraulic chambers 26a and 26b (see FIG. 2) provided in the actuator 19 is detected by a hydraulic sensor 27 (actually, a pair of hydraulic sensors 27a and 27b as shown in FIG. 2). The detection signal is input to the controller 11.

  The controller 11 calculates a torque (passing torque) that passes through the toroidal continuously variable transmission 4 based on a signal from the hydraulic sensor 27. Then, in order to correct the transmission ratio of the toroidal type continuously variable transmission 4 according to the passing torque calculated in this way, the sleeve 28 (see FIG. 2), which is a component of the transmission ratio control valve 21, is applied to the differential pressure. It is displaced by the cylinder 22. The supply / discharge of the pressure oil to / from the differential pressure cylinder 22 is controlled by the correction control valves 23a and 23b. The control valve device 20 includes a stepping motor 29, a line pressure control electromagnetic valve 30, an electromagnetic valve 31 for switching the correction control valves 23a and 23b, the high speed switching valve 24, and a low speed switching. The operation state can be switched by the shift solenoid valve 32 for switching the valve 25. The stepping motor 29, the line pressure control solenoid valve 30, the solenoid valve 31, and the shift solenoid valve 32 are all switched based on the control signal from the controller 11.

  In addition to the signals from the rotation sensors 9, 10, 17 and the hydraulic sensor 27, the controller 11 includes a detection signal from the oil temperature sensor 33, a position signal from the position switch 34, and an accelerator sensor 35. A detection signal, a detection signal from the brake switch 36, a detection signal from the brake fluid pressure switch 37, and a measurement signal from the brake fluid pressure sensor 38 are input. Of these, the oil temperature sensor 33 detects the temperature of the lubricating oil (traction oil) in the casing that houses the continuously variable transmission. The position switch 34 emits a signal indicating an operation position (selection position) of a shift lever (operation lever) provided in the driver's seat for switching a manual hydraulic pressure switching valve 39 described later in FIG. It is. The accelerator sensor 35 is for detecting the opening degree of the accelerator pedal, and is an accelerator operation state detecting means described in the claims. The brake switch 36 and the brake hydraulic pressure switch 37 are brake operation state detection means described in the claims.

  The brake switch 36 detects that the brake pedal has been depressed and generates a signal indicating that, and uses a switch that has been conventionally used to light the brake lamp. Such a brake switch 36 is turned on and off using a slight displacement amount as a threshold value so that the hydraulic pressure in the master cylinder portion does not increase at all when the brake pedal is depressed a little. The presence of a predetermined hysteresis between ON and OFF is the same as in a general detection switch. The brake fluid pressure switch 37 detects that the hydraulic pressure in any part of the brake hydraulic circuit (for example, the part connected to the discharge port of the master cylinder) has increased as the brake pedal is depressed. A signal indicating that. Such ON / OFF of the brake fluid pressure switch 37 is performed using a pressure at which the hydraulic pressure in any one of the above portions is slightly increased (to the extent that almost no braking force is generated) as a threshold value. The presence of a predetermined hysteresis between ON and OFF is the same as in the case of the brake switch 36. Further, the brake hydraulic pressure sensor 38 measures the hydraulic pressure in any part of the brake hydraulic circuit (for example, the part connected to the discharge port of the master cylinder) where the hydraulic pressure proportional to the magnitude of the braking force exists. A signal representing the magnitude of hydraulic pressure is generated.

  The controller 11 is connected to the stepping motor 29 and the electromagnetic for line pressure control based on signals from the switches 34, 36, 37 and the sensors 9, 10, 17, 27, 33, 35, 38. In addition to sending the control signal to the valve 30, the solenoid valve 31, and the shift solenoid valve 32, the control signal is sent to the engine controller 40 for controlling the engine 1. Then, as described in Patent Document 3 described above, the toroidal continuously variable transmission 4 is changed when the speed ratio between the input shaft 3 and the output shaft 14 is changed, or when stopped or traveled at a very low speed. The torque (passing torque) applied to the output shaft 14 after passing through is controlled. Further, in the case of the invention described in Patent Document 5, based on detection signals from the input side rotation sensor 9 and the output side rotation sensor 10, the rotation speed and the rotation direction of the output shaft 14 are calculated. Control the passing torque.

  FIG. 2 shows a hydraulic circuit for controlling the continuously variable transmission as described above. In this hydraulic circuit, the pressure oil sucked from the oil reservoir 41 and discharged by the oil pumps 18a and 18b can be adjusted to a predetermined pressure by the pressure regulating valves 42a and 42b. Of these pressure regulating valves 42 a and 42 b, the adjustment pressure by the pressure regulating valve 42 a for adjusting the hydraulic pressure sent to the manual hydraulic pressure switching valve 39 side is adjustable based on the opening and closing of the line pressure control electromagnetic valve 30. . Then, the pressure oil whose pressure is adjusted by the pressure regulating valves 42a and 42b can be sent to the actuator 19 via the transmission ratio control valve 21 and the correction control for adjusting the stroke of the differential pressure cylinder 22 The valves 23a and 23b can be freely fed based on the opening and closing of the electromagnetic valve 31. Further, the pressure oil is fed into the hydraulic pressing device 5.

  The pressure oil can be fed into the hydraulic chamber of the low speed clutch 15 or the high speed clutch 16 via the manual hydraulic pressure switching valve 39 and the high speed switching valve 24 or the low speed switching valve 25. Of these low speed and high speed clutches 15 and 16, the low speed clutch 15 is connected when realizing a low speed mode in which the speed reduction ratio is increased (including an infinite speed ratio) and the speed reduction ratio is increased. The connection is broken when realizing the high-speed mode to be reduced. In contrast, the high speed clutch 16 is disconnected when realizing the low speed mode and is connected when realizing the high speed mode. The supply / discharge state of the pressure oil to the low speed and high speed clutches 15 and 16 is switched according to the switching state of the shift solenoid valve 32.

  Further, in the case of the present embodiment, when the brake pedal is depressed while traveling without stepping on the accelerator pedal, the gear ratio of the continuously variable transmission is adjusted according to the operation state of the brake pedal. It is configured. In this case, whether or not the vehicle is running is determined by a detection signal from the output shaft rotation sensor 17. That is, since the rotational speed of the output shaft 14 is proportional to the traveling speed of the vehicle, only when the traveling speed known from the rotational speed is equal to or higher than a preset threshold value (Vkm / h), the controller 11 is The function of adjusting the speed ratio of the continuously variable transmission according to the operating state of the brake pedal, which is a feature of the invention, is exhibited. When the vehicle is stopped or traveling at a very low speed (for example, less than 1 km / h), and when the vehicle is traveling with the accelerator pedal depressed, the continuously variable transmission is set according to the operation state of the brake pedal. Therefore, the controller 11 does not exhibit the above function. Whether or not the accelerator pedal is depressed is determined by a detection signal from the accelerator sensor 35. The operation state of the brake pedal (depressing speed and depressing strength) is determined by detection signals or measurement signals of the brake switch 36, brake fluid pressure switch 37, and brake fluid pressure sensor 38. The speed ratio of the continuously variable transmission can be adjusted by adjusting the speed ratio of the toroidal-type continuously variable transmission 4 by the actuator 19 as well as if necessary (the speed of the entire continuously variable transmission is changed at that time). (According to the ratio), the low speed and high speed clutches 15 and 16 are both connected and disconnected (mode switching).

  First, in the case where the speed ratio of the continuously variable transmission is adjusted according to the depression speed of the brake pedal when the brake pedal is depressed during traveling (the invention described in claim 4), FIG. This will be described with reference to. In this case, as shown in the flowchart of FIG. 3, whether or not the traveling speed of the vehicle is equal to or higher than a preset threshold value (Vkm / h) is detected in the detection signal of the output shaft rotation sensor 17 in step 1. Judgment based on. If the traveling speed is less than the threshold value, the gear ratio control based on the depression of the brake pedal is not performed, and the processing is terminated as it is.

  On the other hand, when the travel speed is equal to or higher than the threshold value, the process proceeds to step 2 to determine whether or not the brake pedal is depressed based on the detection signal of the brake switch 36. If it is determined in step 2 that the brake pedal is not depressed, gear ratio control based on depression of the brake pedal is not performed. However, if the brake pedal has been depressed before that, and if gear ratio control has been performed as a result of this depression, the control is returned after steps 3 and 4 to return the gear ratio to the normal control value. To do. If the brake pedal has not been depressed before that, and the gear ratio control associated with this depression has not been performed, the value of the gear ratio control and the value at that point in time are related to the gear ratio value. Steps 3 and 4 are passed through as they are. The operation in steps 3 and 4 in the case where the brake pedal has been depressed before that and the gear ratio control accompanying the depression has been performed will be described later.

  If it is determined in step 2 that the brake pedal is depressed, gear ratio control based on depression of the brake pedal is performed. In this case, first, in step 5, the depression speed of the brake pedal is obtained. The stepping speed is obtained based on the length of time from when the brake switch 36 is turned on until the brake hydraulic pressure switch 37 is turned on. That is, as the amount of depression (depression force) of the brake pedal changes, the ON / OFF state of the brake switch 36 changes as shown by a thin line a in FIG. The ON / OFF state of the hydraulic pressure switch 37 changes as shown by the entire line b in FIG. That is, when the brake pedal is depressed, the brake fluid pressure switch 37 is turned on after the time T has elapsed since the brake switch 36 was first turned on. As shown in FIG. 4B, the time T becomes shorter as the brake pedal depressing speed S is faster (the brake pedal is operated more rapidly). Therefore, the controller 11 obtains the brake pedal depression speed S based on the time T from the relationship shown in FIG.

  If the stepping-on speed S of the brake pedal is obtained in step 5, the gear ratio of the continuously variable transmission shown in FIG. 1 is adjusted in the next step 6 according to the operating state of the brake pedal. That is, the controller 11 obtains the target speed ratio “T_eCVT” of the continuously variable transmission based on the brake operating state, that is, the stepping speed S, and determines the speed ratio of the continuously variable transmission as the target speed ratio. The gear ratio is adjusted to “T_eCVT”. In many cases, the target gear ratio is realized (without connection / disconnection of the low speed clutch 15 and the high speed clutch 16), and the gear ratio “eCVU” of the toroidal continuously variable transmission 4 is achieved. Adjust by adjusting. Therefore, in the following description, the target speed ratio “T_eCVU” of the toroidal type continuously variable transmission 4 is obtained based on the stepping speed S, and the speed ratio of the toroidal type continuously variable transmission 4 is determined as the target speed ratio “T_eCVU”. To adjust to "." However, if the gear ratio of the entire continuously variable transmission at the moment when the brake pedal is depressed is close to the gear ratio at which the low speed mode and the high speed mode are switched, the stepless speed S is used to determine the stepless speed. When the target gear ratio “T_eCVT” of the transmission is obtained, it may be necessary to connect and disconnect the low speed clutch 15 and the high speed clutch 16 in order to realize the target gear ratio “T_eCVT”. There is also. Even in such a case, the target gear ratio “T_eCVT” is basically the same except that the clutches 15 and 16 are connected and disconnected and the gear ratio of the toroidal continuously variable transmission 4 is adjusted. Is realized.

  If it is determined in step 2 that the brake pedal has been operated, the transmission ratio of the toroidal type continuously variable transmission 4 is set to a predetermined amount so that the transmission ratio of the continuously variable transmission as a whole changes to the deceleration side. Only adjust. The predetermined amount is determined according to the depression force of the brake pedal (stepping force / braking force) as shown in FIGS. 5 to 8 described later, but is simply a predetermined amount in the description of FIG. In any case, when the gear ratio of the toroidal continuously variable transmission 4 is adjusted to a predetermined amount reduction side, an adjustment amount (tuning value α) is set for the gear ratio value itself, or the toroidal type continuously variable transmission 4 is adjusted. An adjustment amount (tuning value α) is set for the position of the stepping motor 29 (SM) for adjusting the gear ratio of the continuously variable transmission 4. In the former case, in step 6, the adjustment amount (tuning value α) is subtracted from the gear ratio “P_eCVU” of the toroidal-type continuously variable transmission 4 at that time (the moment when the brake pedal is depressed). A target speed ratio “T_eCVU” (= P_eCVU−α) (which changes the speed ratio of the continuously variable transmission as a whole to the deceleration side) is set. On the other hand, in the latter case, in step 6, the target position “T_SM” (= P_SM−) obtained by subtracting the adjustment amount (tuning value α) from the position “P_SM” of the stepping motor 29 at that time. Set α).

  If the target gear ratio “T_eCVU” of the toroidal-type continuously variable transmission 4 or the target position “T_SM” of the stepping motor 29 is set in the step 6, the target gear ratio “ "T_eCVU" or the time (shift speed G) until the target position "T_SM" is reached. That is, as shown in FIG. 4C, the controller 11 increases the speed G for adjusting the speed ratio to the deceleration side as the brake pedal depression speed S increases (the tuning value α). Make adjustments in a short time).

  In this way, when the target transmission ratio “T_eCVU” of the toroidal type continuously variable transmission 4 or the target position “T_SM” of the stepping motor is set and the shift speed G is obtained, the following step 8 is performed. Shift control is performed. Then, the speed ratio of the continuously variable transmission as a whole is set to the target speed ratio “T_eCVT”. Thereafter, the above steps 2 and 5 to 8 are repeated, and this target speed ratio “T_eCVT” is maintained unless the operation state of the brake pedal is changed.

On the other hand, if it is determined in step 2 that the depression of the brake pedal has been released, any one of the following controls (A) to (C) is performed. Of these (A) to (C), which control (A) or (B) is performed is determined, for example, in accordance with the traveling speed at that time. (c) is when the accelerator pedal is depressed.
(A) Until the state where the gear ratio should be adjusted, such as when the brake pedal is depressed again or when the accelerator pedal is depressed, The transmission gear ratio is maintained at the determined time (the invention according to claim 6).
(B) Unless the state where the gear ratio should be adjusted next appears, the gear ratio at the time when the depression of the brake pedal is released is immediately before the brake pedal is operated (when the determination in step 2 is performed). The gear ratio is gradually returned to (invention of claim 7).
(C) Considering the detection signal of the accelerator sensor 35, the speed is gradually changed to a target speed ratio obtained from the travel speed when the brake pedal is released and the accelerator pedal is depressed ( The invention described in claim 8).

  FIG. 3 shows (C). That is, in the example shown in FIG. 3, the gear ratio in a normal traveling state (a state where the brake pedal is not depressed) is set as the target gear ratio after the brake pedal is released. The target gear ratio is determined by the controller 11 taking into account the detection signal of the accelerator sensor 35 and the traveling speed obtained from the detection signal of the output shaft rotation sensor 17. Or a target position of the stepping motor 29.

If the target gear ratio after releasing the depression of the brake pedal is set in this way, in step 4, a gear speed G ′ for realizing this target gear ratio is set. The speed change speed G ′ is set by either of the following (a) and (b).
(a) Regardless of the difference between the gear ratio at the moment when the depression of the brake pedal is released and the target gear ratio, the speed is always constant and gradually returned (for example, 1 to several seconds are required).
(b) The shift speed is adjusted according to the difference between the gear ratio at the moment when the brake pedal is released and the target gear ratio, and the shift speed G ′ is increased as the difference increases.
In any case, a smooth shift operation can be realized without causing a shift shock after releasing the depression of the brake pedal, and without causing the passenger to feel uncomfortable. In particular, according to (b) above, even when the amount of adjustment (tuning value α) that accompanies the depression of the brake pedal is large, the time required to reach the target gear ratio is reduced while preventing the occurrence of a situation in which the passenger feels uncomfortable. Can be planned.

  As described above, when the target gear ratio after the release of the depression of the brake pedal is set and the speed change speed G ′ is set, the speed change control is performed in the next step 8. Then, the transmission gear ratio of the continuously variable transmission as a whole is set to the target transmission gear ratio, and the process ends. Thereafter, the above steps 2 to 4 and 8 are repeated, and normal shift control is performed unless the brake pedal is depressed.

  Next, when it is determined that the brake pedal is operated, a predetermined amount (adjustment amount) for adjusting the transmission ratio of the toroidal-type continuously variable transmission 4 so that the transmission ratio of the continuously variable transmission as a whole changes to the deceleration side. The function of determining the tuning value α) according to the depression force of the brake pedal (stepping force / braking force) will be described with reference to FIGS. Of these, FIG. 5 is a flowchart showing the operation of obtaining the predetermined amount and further performing the shift control. Steps 1 to 4 in FIG. 5 are the same as steps 1 to 4 in FIG. 3 and FIG. Step 6 is the same as Step 5 in FIG. 3 and Steps 8-9 in FIG. 5 are the same as Steps 7-8 in FIG. 3 (substantially the same as Step 5 in FIG. 3 and Step 6 in FIG. 5). The overlapping explanation is omitted or simplified. In short, the feature of FIG. 5 is that the predetermined amount (degree of adjustment of the gear ratio to the deceleration side) is obtained from steps 5 to 7 as shown in FIG.

  If it is determined in step 2 of the flowchart shown in FIG. 5 that the brake pedal is being depressed, the stepping force of the brake pedal is obtained based on the measurement signal of the brake hydraulic pressure sensor 38 in step 5. . The depression force of the brake pedal obtained from this measurement signal is proportional to the braking force that the driver wants to obtain. Next, when the brake pedal depression speed S is obtained by differentiating the change in the measurement signal of the brake fluid pressure sensor 38 in step 6, the controller 11 obtains the predetermined amount in step 7. . That is, a predetermined amount (adjustment amount, variable amount) relating to the gear ratio of the toroidal continuously variable transmission 4 required for the controller 11 to change the gear ratio of the continuously variable transmission as a whole to the deceleration side based on the stepping force. The tuning value α) is obtained from the relationship shown in FIG. In this case, the controller 11 increases the degree of adjusting the speed ratio to the deceleration side as the stepping force increases, as in the fifth aspect of the invention. FIG. 5 shows the case where the adjustment amount (tuning value α) is set with respect to the speed ratio value itself of the toroidal-type continuously variable transmission 4. However, this adjustment amount can also be set with respect to the position of the stepping motor 29 (SM) as in step 6 of FIG.

  In step 6, the predetermined amount α is obtained, and the target transmission ratio “T_eCVU” (or the target position “T_SM” of the stepping motor 29) of the toroidal continuously variable transmission 4 is set based on the predetermined amount α. Further, when the speed change speed G is obtained in the next step 8, the speed change control is executed in the next step 9. Then, the speed ratio of the continuously variable transmission as a whole is set to the target speed ratio “T_eCVT”. Thereafter, the above steps 2 and 5 to 9 are repeated, and this target speed ratio “T_eCVT” is maintained unless the operating state of the brake pedal is changed. The operation in the case where it is determined in step 2 that the depression of the brake pedal is released is the same as in the case of FIG.

  Next, FIG. 7 shows a more practical operation compared to the operations shown in the flowcharts of FIGS. That is, the flowcharts shown in FIGS. 3 and 5 are implemented in a combined state, but none of the operation of the accelerator pedal is taken into consideration. After releasing the brake pedal, it is only considered to return to normal control. On the other hand, when the vehicle is driven, not only the brake pedal but also the accelerator pedal is operated, and the accelerator pedal is often depressed immediately after releasing the depression of the brake pedal. FIG. 7 is for making it possible to perform a smooth shifting operation when the accelerator pedal is depressed immediately after releasing the depression of the brake pedal in this way. To understand that the operation shown in Fig. 7 is necessary, suddenly depress the brake pedal from the state where the gear ratio of the continuously variable transmission is adjusted to the deceleration side as the brake pedal is depressed. Let's consider the case where the accelerator pedal is released and the accelerator pedal is depressed immediately. In such a case, if the gear ratio of the continuously variable transmission is immediately changed to a gear ratio according to the depression of the accelerator pedal, the change of the gear ratio may be too rapid, which may cause a driver or other passengers to feel uncomfortable. There is. Therefore, in the flowchart shown in FIG. 7, when it is determined that the depression of the brake pedal is released, the continuously variable transmission is based on the measurement signal of the output shaft rotation sensor 17 and the detection signal of the accelerator sensor 35. The gear ratio is gradually changed to a target gear ratio obtained from the traveling speed at that time and the depressed state of the accelerator pedal.

  When such FIG. 7 is compared with FIG. 5, steps 1 to 7 in FIG. 7 are basically the same as steps 1, 2, and 5 to 9 in FIG. However, in step 7 of FIG. 5 described above, the predetermined amount (adjustment amount, tuning value α) for adjusting the gear ratio to the deceleration side is changed to the map of FIG. 6 (relationship between brake pedal depression force and predetermined amount). ) And the target gear ratio is determined from this predetermined amount and the current gear ratio, whereas in step 5 of FIG. 7, the map (the brake pedal depression force) shown in FIG. The target gear ratio is determined based on the relationship between each vehicle speed and the target gear ratio. In FIG. 8B, the horizontal axis represents the vehicle speed, the vertical axis represents the gear ratio, and the depression force of the brake pedal is represented by the position of each line. Of the lines representing the depression force of the brake pedal, all lines represent a state where the depression force of the brake pedal is weak, and a thin line represents a state where the depression force of the brake pedal is strong, for each magnitude of the depression force. Further, in step 6 of FIG. 7, the shift speed G (time to reach the target gear ratio) from the depression speed S of the brake pedal obtained in step 4 of FIG. The relationship is determined based on the relationship between the depression speed S of the brake pedal and the transmission speed G).

  Furthermore, in the case of the flowchart shown in FIG. 7, when it is determined in step 2 that the brake pedal has been released, and in step 8 it is determined that the accelerator pedal is depressed, the next step 9 Thus, the opening degree of the accelerator pedal is detected based on the detection signal of the accelerator sensor 35. Next, in step 10, the depression speed s of the accelerator pedal is obtained by differentiating the change in the detection signal (accelerator opening) of the accelerator sensor 35. Then, in step 11, the target gear ratio is obtained based on the accelerator opening and the vehicle speed, for example, using a map as shown in FIG. In FIG. 8A, the horizontal axis represents the vehicle speed, the vertical axis represents the gear ratio, and the accelerator opening (the degree of depression of the accelerator pedal) is represented by the position of each line. Of the lines representing the accelerator opening, all lines represent the state in which the accelerator pedal is released, and the thin line represents the state in which the accelerator pedal is depressed for each degree of depression (accelerator opening).

  In step 12, the speed g of the speed change operation is obtained from FIG. 9A based on the depression speed s of the accelerator pedal obtained in step 10 and the target speed ratio obtained in step 11. Then, as in the other cases (shown in FIGS. 3 and 5), in step 7, the speed change control is performed to set the speed ratio of the continuously variable transmission as a whole to the target speed ratio “T_eCVT”. To do. Thereafter, steps 1, 2, 8-12, and 7 are repeated to maintain the target speed ratio as long as the operating state of the brake pedal does not change. Steps 13 and 14 showing the operation when it is determined in step 8 that the accelerator pedal is not depressed are basically the same as steps 3 and 4 in FIG. 5 except that the accelerator opening is not taken into consideration. It is.

  The shift control device for a continuously variable transmission for a vehicle according to the present invention is configured and operated as described above, thereby estimating the intention of the driver how the vehicle is going to run at present and continuously changing the speed. The gear ratio of the device can be adjusted to a value considered appropriate. For this reason, the braking force based on the engine brake can be set to an appropriate magnitude in order to ensure a vehicle speed suitable for the road conditions and the driver's intention, and the operation of the accelerator pedal and the brake pedal need not be repeated frequently. However, it is possible to drive at an appropriate vehicle speed, reduce driver fatigue, and prevent traffic jams and rear-end collisions. In addition, the vehicle can be configured at a low cost, and the behavior of the vehicle can be adapted to the driver's intention.

  The operation status of the brake pedal by the driver can also be detected by detecting the pressure of the brake fluid with a pressure sensor. In this case, since the pressure accompanying the depression of the brake pedal can be determined linearly, the gear ratio of the continuously variable transmission can be adjusted linearly. In addition, in order to suppress the cost increase due to the addition of sensors and to adjust the gear ratio linearly, a pressure switch is used to turn the brake fluid pressure on and off at three different levels. This pressure can be detected in a plurality of stages.

The block diagram which shows one example of the continuously variable transmission which the transmission control apparatus of this invention implements. FIG. 3 is a hydraulic circuit diagram for shift control. The flowchart which shows the 1st example of operation | movement of transmission control. The diagram for demonstrating operation | movement of each part. The flowchart which shows the 2nd example of speed change operation | movement. The diagram which shows the relationship between the depression force of a brake pedal, and the adjustment amount of a gear ratio. The flowchart which shows the 3rd example of speed change operation | movement. The map which shows the relationship between a vehicle speed and a target gear ratio, (A) for every accelerator opening, (B) for every brake pedal depression force, respectively. FIG. 4A is a diagram illustrating a relationship between an accelerator depression speed s and a shift speed g, and FIG. 5B is a diagram illustrating a relationship between a brake pedal depression speed S and a shift speed G.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Damper 3 Input shaft 4 Toroidal type continuously variable transmission 5 Pressing device 6 Input side disk 7 Power roller 8 Output side disk 9 Input side rotation sensor 10 Output side rotation sensor 11 Controller 12 Planetary gear mechanism 13 Clutch device 14 Output Shaft 15 Low speed clutch 16 High speed clutch 17 Output shaft rotation sensor 18, 18, 18b Oil pump 19 Actuator 20 Control valve device 21 Gear ratio control valve 22 Differential pressure cylinder 23a, 23b Correction control valve 24 High speed switching valve 25 Low speed Switch valve 26a, 26b Hydraulic chamber 27, 27a, 27b Hydraulic sensor 28 Sleeve 29 Stepping motor 30 Line pressure control solenoid valve 31 Solenoid valve 32 Shift solenoid valve 33 Oil temperature sensor 34 Position switch 35 Acceleration sensor 36 Brake switch 37 Brake fluid pressure switch 38 Brake fluid pressure sensor 39 Manual hydraulic pressure switching valve 40 Engine controller 41 Oil reservoir 42a, 42b Pressure regulating valve

Claims (9)

  Continuously variable transmission, controller for adjusting the gear ratio of the continuously variable transmission, speed detecting means for detecting the traveling speed of the vehicle, and brake operating state for detecting the operating state of the brake pedal Detecting means, and when the controller determines that the vehicle is in a traveling state by the traveling speed detecting means and that the brake pedal is operated by the brake operation state detecting means, A shift control device for a continuously variable transmission for a vehicle having a function of adjusting a gear ratio of the continuously variable transmission according to an operation state of the brake pedal.   The controller has a function of obtaining a target gear ratio of the continuously variable transmission based on the operation state of the brake pedal detected by the brake operation state detecting means, and adjusting the gear ratio of the continuously variable transmission to the target gear ratio. A shift control apparatus for a continuously variable transmission for a vehicle according to claim 1.   The transmission control device for a continuously variable transmission for a vehicle according to claim 2, wherein when it is determined that the brake pedal is operated, the transmission ratio of the continuously variable transmission is adjusted to the deceleration side.   The brake operation state detection means has a function of obtaining a depression speed of a brake pedal, and the controller has a function of increasing a speed of adjusting the speed ratio to a deceleration side as the depression speed increases. A shift control device for a continuously variable transmission for a vehicle as described in 1.   The brake operation state detection means has a function of obtaining a depression force of the brake pedal, and the controller has a function of increasing the degree of adjusting the speed ratio to the deceleration side as the depression force increases. The shift control device for a continuously variable transmission for a vehicle according to any one of?   When it is determined by the brake operation state detection means that the operation of the brake pedal has been completed, the controller performs the above-described operation until the state in which the gear ratio of the continuously variable transmission and the gear ratio should be adjusted next appears. The transmission control device for a continuously variable transmission for a vehicle according to any one of claims 3 to 5, which has a function of maintaining a gear ratio at a time point when it is determined that an operation has been completed.   If it is determined by the brake operation state detection means that the operation of the brake pedal has been completed, the controller does not perform the above operation unless a state in which the gear ratio of the continuously variable transmission and the gear ratio should be adjusted next appears. The vehicular vehicle according to any one of claims 3 to 5, which has a function of gradually returning from a gear ratio at a time point when it is determined to be completed to a gear ratio immediately before the brake pedal is operated. A transmission control device for a continuously variable transmission.   Accelerator operation state detection means for detecting the depression state of the accelerator pedal is provided, and the controller determines the speed ratio of the continuously variable transmission when it is determined by the brake operation state detection means that the operation of the brake pedal has been completed. The continuously variable transmission for a vehicle according to any one of claims 3 to 5, which has a function of gradually changing to a target speed ratio obtained from a traveling speed at that time and a depression state of the accelerator pedal. Gear shift control device. The continuously variable transmission is a continuously variable transmission configured by combining a toroidal-type continuously variable transmission mechanism and a gear-type differential mechanism and capable of stopping the output shaft while the input shaft is rotated. A shift control device for a continuously variable transmission for a vehicle according to any one of?

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