JP2012159159A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a structure capable of sufficiently reducing a load on a starter motor for starting an engine without the occurrence of excessive sliding at each traction part, in a continuously variable transmission whose gear ratio can be changed infinitely.SOLUTION: After the engine is started, a controller gradually increases pressing force generated by a pressing device on condition that a shift lever is left in a non-travel state. Then, tilting angles of trunnions having supported respective power rollers are mutually synchronized. Thereafter, on the basis of a learning function, a step count for adjusting the gear ratio of a troidal type continuously variable transmission to a desired value is learned.

Description

  The present invention is a combination of a toroidal-type continuously variable transmission and a planetary gear unit, and the rotation direction of the output member can be converted into both directions with the input member rotated in one direction with the stop state interposed therebetween. The present invention relates to an improvement of a continuously variable transmission that can change a transmission gear ratio to infinity.

  2. Description of the Related Art Toroidal continuously variable transmissions that can be used as an automatic transmission for automobiles have been widely known, for example, as described in Patent Documents 1 to 3. Further, it has been widely known that a continuously variable transmission device is configured by combining a toroidal type continuously variable transmission and a planetary gear type transmission, as described in Patent Documents 4 to 6. In particular, in Patent Documents 5 to 6, among these, by adjusting the speed ratio of the toroidal-type continuously variable transmission (hereinafter simply referred to as “speed ratio”; the same applies in the present specification and claims). The speed ratio of the continuously variable transmission as a whole (hereinafter referred to as “speed ratio”, the same applies in the present specification and claims), with the stop state (the state where the speed ratio is infinite) across the forward state And a continuously variable transmission that can be switched between a reverse state and a reverse state. Patent Document 7 describes an invention relating to a hydraulic control circuit for controlling the speed ratio of such a continuously variable transmission. Patent Document 8 describes a structure for opening / closing a speed ratio control valve for adjusting the speed ratio. Further, Patent Document 9 describes an invention for learning and storing a state that realizes the state where the gear ratio is infinite, so that this state can be reliably realized.

  The present invention relates to an improvement of a continuously variable transmission capable of realizing a state with an infinite speed ratio as described above. First, regarding the structure and operation of such a continuously variable transmission, the above-mentioned patent document Based on the description of FIG. This continuously variable transmission is formed by combining a toroidal type continuously variable transmission 1 and a planetary gear type transmission 2 and has an input shaft 3 as an input member and an output shaft 4 as an output member. Between the input shaft 3 and the output shaft 4, the input rotary shaft 5 and the transmission shaft 6 of the toroidal-type continuously variable transmission 1 are provided concentrically with the shafts 3 and 4. In the state where the front stage unit 7 and the middle stage unit 8 of the planetary gear type transmission 2 are spanned between the input rotary shaft 5 and the transmission shaft 6, the rear stage unit 9 is connected to the transmission shaft 6 and the transmission shaft 6. Each is provided in a state of being spanned between the output shaft 4.

  The toroidal continuously variable transmission 1 includes a pair of input disks 10a and 10b, an integrated output disk 11, and a plurality of power rollers 12a and 12b. Of these, both input disks 10a and 10b are concentrically connected to each other via the input rotating shaft 5 and are coupled so as to freely rotate in synchronization. The output disk 11 is supported between the input disks 10a and 10b so as to be concentric with the input disks 10a and 10b and to be rotatable relative to the input disks 10a and 10b. . Further, a plurality of each of the power rollers 12a and 12b is provided between the both axial side surfaces of the output disk 11 and one axial side surface of the both input disks 10a and 10b (2 in the illustrated example). 4 pieces each, a total of 4 pieces). Power is transmitted between the input disks 10a and 10b and the output disk 11 while rotating with the rotation of the input disks 10a and 10b.

  The output disk 11 is rotatably supported at both ends in the axial direction by a pair of support columns 14 and 14 and rolling bearings 15 and 15 which are thrust angular ball bearings. Yes. Further, support plates 16 and 16 are supported in the vicinity of both end portions of the support columns 14 and 14, respectively. Then, a plurality of trunnions 17a and 17b are provided between the support plates 16 and 16 respectively, and swinging and axial directions about pivots 18 and 18 provided concentrically with each other at both ends (see FIGS. 4 to 5). Supports displacement in the vertical direction). Further, the power rollers 12a and 12b are respectively rotated on the inner side surfaces (surfaces facing each other) of the trunnions 17a and 17b via support shafts 19 and 19 and a plurality of sets of rolling bearings, and the input rotary shaft 5 A slight displacement in the axial direction is supported freely. The peripheral surfaces of the power rollers 12a and 12b are brought into rolling contact with the axial side surfaces of the input disks 10a and 10b and the axial side surfaces of the output disk 11. The rolling contact portions between these surfaces serve as traction portions that transmit power via traction oil.

  Further, the base end portion (left end portion in FIG. 4) of the input rotary shaft 5 is coupled to an engine crankshaft (not shown) via the input shaft 3, and the input rotary shaft 5 is rotationally driven by the crankshaft. Like. Also, a hydraulic pressing device 20 is provided between the base end portion of the input rotating shaft 5 and the input disk 10a on the side close to the engine (left side in FIG. 4), and each traction portion has an appropriate The surface pressure can be applied. Further, the output disk 11 is spline-engaged with the base end portion (the left end portion in FIG. 4) of the hollow rotary shaft 21. The hollow rotary shaft 21 is inserted into the input disk 10b on the side far from the engine (right side in FIG. 4) so that the rotational force of the output disk 11 can be taken out. Further, a sun gear for constituting the front stage unit 7 of the planetary gear type transmission 2 at a portion protruding from the outer surface of the input disk 10b at the tip end portion (right end portion in FIG. 4) of the hollow rotary shaft 21. 22 is fixed.

  On the other hand, a carrier 23 is provided between the input disk 10b and a portion protruding from the hollow rotation shaft 21 at the tip end portion (right end portion in FIG. 4) of the input rotation shaft 5, and this input disk. 10b and the input rotation shaft 5 rotate in synchronization with each other. And at the circumferentially equidistant positions (generally 3 to 4 positions) on both sides in the axial direction of the carrier 23, each is a double pinion type, and the front stage unit 7 of the planetary gear type transmission 2 and The planetary gears 24 to 26 constituting the middle unit 8 are rotatably supported. Further, a ring gear 27 is rotatably supported around one half of the carrier 23 (the right half of FIG. 4). A second sun gear 28 fixed to the base end portion (left end portion in FIG. 4) of the transmission shaft 6 is disposed on the inner diameter side of the ring gear 27.

  A second carrier 29 for constituting the rear stage unit 9 is coupled and fixed to the base end portion (left end portion in FIG. 4) of the output shaft 4. The second carrier 29 and the ring gear 27 are coupled via a low speed clutch 30. Further, a third sun gear 31 is fixedly provided near the tip of the transmission shaft 6 (near the right end in FIG. 4). A second ring gear 32 is disposed around the third sun gear 31, and a high-speed clutch 33 is provided between the second ring gear 32 and a fixed portion such as the casing 13. Further, a plurality of sets of planetary gears 34 and 35 disposed between the second ring gear 32 and the third sun gear 31 are rotatably supported by the second carrier 29.

  In the case of the continuously variable transmission configured as described above, the power transmitted from the input rotating shaft 5 to the integrated output disk 11 via the pair of input disks 10a and 10b and the power rollers 12a and 12b is the above described hollow. It is taken out through the rotating shaft 21. In the so-called low speed mode in which the low speed clutch 30 is connected and the high speed clutch 33 is disconnected, the input rotary shaft is adjusted by adjusting the gear ratio of the toroidal continuously variable transmission 1. The rotation speed of the output shaft 4 can be converted into forward rotation and reverse rotation with a stop state (a state where the speed ratio is infinite) called a so-called geared neutral (G / N) with the rotation speed of 5 kept constant. Become. On the other hand, in the so-called high-speed mode in which the high-speed clutch 33 is connected and the low-speed clutch 30 is disconnected, the speed ratio of the toroidal continuously variable transmission 1 is changed to the higher speed side. The speed ratio of the step transmission as a whole also changes to the speed increasing side. In this state, the continuously variable transmission shown in FIGS. 4 to 5 transmits a part of the power transmitted from the input shaft 3 to the output shaft 4 through the input-side rotating shaft 5 to the toroidal continuously variable transmission. 1 is bypassed, so-called power split state. In this power split state, the torque passing through the toroidal continuously variable transmission 1 can be reduced, so that the durability of the toroidal continuously variable transmission 1 and the transmission efficiency of the continuously variable transmission as a whole are improved. I can plan. The relationship between the speed ratio of the toroidal continuously variable transmission 1 and the speed ratio of the continuously variable transmission in both the low speed and high speed modes, and the torque passing through the toroidal continuously variable transmission 1 in each mode state. Since the direction and size are described in Patent Documents 5, 7, 9 and the like and widely known in the past, illustration and detailed description thereof are omitted.

  Adjustment of the gear ratio of the toroidal type continuously variable transmission 1 incorporated in the continuously variable transmission as described above is carried out by using the trunnions 17a and 17b of the pivot shafts 18 and 18 by hydraulic actuators 36 and 36, respectively. This is done by displacing in the axial direction. When the trunnions 17a and 17b are displaced in the axial direction of the pivots 18 and 18, the circumferential surfaces of the power rollers 12a and 12b supported by the trunnions 17a and 17b and the disks 10a, 10b, The direction of the tangential force acting on the rolling contact portion (traction portion) with the 11 axial side surface changes with respect to the axial direction of each of the pivot shafts 18 and 18. Specifically, each traction portion is in a neutral position (the center of each traction portion includes the central axis of each of the disks 10a, 10b, 11 and is orthogonal to a virtual straight line connecting the central axes of the respective pivots 18, 18) In the direction in which the trunnions 17a and 17b are swung to the deceleration side or the acceleration side about the pivots 18 and 18 according to the direction of the deviation. Power is added. And the position of each said traction part changes regarding the radial direction of each said disk 10a, 10b, 11, and the said gear ratio changes. If the traction portions are returned to the neutral position in a state where the gear ratio has reached a desired value, the gear ratio of the toroidal continuously variable transmission 1 can be maintained at the desired value. The actuators 36, 36 are connected to the trunnions 17 a, 17 b based on the power transmission while the toroidal-type continuously variable transmission 1 transmits power. Axial thrust load (a force called “2Ft” in the technical field of toroidal type continuously variable transmissions) is supported.

  As described above, a mechanism for adjusting the transmission ratio of the toroidal type continuously variable transmission 1 to a desired value and maintaining the adjusted value will be described based on the description in Patent Document 8. As shown in FIG. 6, this mechanism includes a transmission ratio control valve 37, a stepping motor 38, and a recess cam 39. Among these, the transmission ratio control valve 37 is a combination of the spool 40 and the sleeve 41 so as to allow relative displacement in the axial direction. Based on the relative displacement between the spool 40 and the sleeve 41, the hydraulic power source 42, The supply / discharge state of the actuator 36 with the hydraulic chambers 43a and 43b is switched. The spool 40 and the sleeve 41 are relatively displaced by the movement of any one of the trunnions 17a and 17b and the stepping motor 38. In the illustrated example, the movement of any one trunnion 17 a, that is, the axial displacement of the pivot 18 and the swing displacement about the pivot 18 are transmitted via the recess cam 39 and the link arm 44. The spool 40 is transmitted to the spool 40 and displaced in the axial direction, and the sleeve 41 is displaced in the axial direction by the stepping motor 38.

  When adjusting the gear ratio of the toroidal-type continuously variable transmission 1, the sleeve 41 is displaced to a predetermined position by the stepping motor 38, and the gear ratio control valve 37 is opened in a predetermined direction. Then, pressure oil is supplied to and discharged from the hydraulic chambers 43a and 43b of the actuators 36 and 36 attached to the trunnions 17a and 17b in a predetermined direction, and the trunnions 17a and 17b are supplied by the actuators 36 and 36. Are displaced in the axial direction of each of the pivots 18 and 18, respectively. As a result, the traction portions related to the power rollers 12a and 12b supported by the trunnions 17a and 17b are displaced from the neutral position, and the speed ratio starts to change. In this way, at the moment when each traction section shifts from the neutral position and the gear ratio starts to change, the open / close state of the gear ratio control valve 37 is changed according to the axial displacement of each trunnion 17a, 17b. The direction is switched to the opposite direction. Accordingly, the trunnions 17a and 17b start to move (return) toward the neutral position with respect to the axial direction from the moment when the swing displacement starts for shifting. Then, in a state where the speed ratio has reached the desired value, the speed ratio control valve 37 is closed simultaneously with the return of the traction units to the neutral position. As a result, the gear ratio of the toroidal type continuously variable transmission 1 is maintained at the desired value.

The structure and operation of the continuously variable transmission capable of realizing the geared neutral state are as described above. The structure and operation of the mechanism for adjusting the transmission ratio of the toroidal continuously variable transmission 1 incorporated in the continuously variable transmission are as described above. However, there are problems as described later in terms of putting the continuously variable transmission into practical use. This problem is caused by adopting the following structures (1) to (5) for practical use of this continuously variable transmission.
(1) Instead of a mechanical loading cam device, a hydraulic device is used as the pressing device 20 for ensuring the surface pressure of each traction section.
(2) Even if the pressurizing spring 46 for ensuring the surface pressure of each of the traction portions in a state where the hydraulic pressure is not introduced into the hydraulic chambers 45a and 45b of the pressing device 20, it may be omitted or provided. Use one that has only a small elasticity to prevent rattling during transportation.
(3) A mechanical synchronization mechanism for synchronizing the tilt angles of the trunnions 17a and 17b is omitted.
(4) Learning by comparing the number of steps of the stepping motor 38 for controlling the switching of the transmission ratio control valve 37 with the actual transmission ratio of the toroidal-type continuously variable transmission 1; A function for storing in a controller for controlling the stepping motor 38 is provided.
(5) Pressure oil to the hydraulic chambers 43a and 43b of the actuators 36 and 36 provided for the trunnions 17a and 17b in order to displace the trunnions 17a and 17b in the axial directions of the pivots 18 and 18, respectively. Is supplied and discharged by a single gear ratio control valve 37. A precess cam 39 and the like for feeding back the movement (axial displacement amount and tilt angle) of each trunnion 17a, 17b to the transmission ratio control valve 37 is provided only in any one trunnion 17a.
Hereinafter, the reason why the structures (1) to (5) are employed, and the problems caused by adopting these structures will be described.

  First, the reason why the structure (1) is adopted is that an excessive so-called gross slip is called at each traction portion of the toroidal-type continuously variable transmission 1 when the low-speed and high-speed clutches 30 and 33 are switched. This is to prevent slippage. As is well known in the technical field of a continuously variable transmission comprising a combination of a toroidal type continuously variable transmission 1 and a planetary gear type transmission 2, when passing the geared neutral point (G / N point), and When the clutches 30 and 33 are switched, the direction of torque passing through the toroidal continuously variable transmission 1 is reversed. Therefore, in the case of the loading cam device, when the G / N point is passed or when the clutches 30 and 33 are switched, the pressing force (loading pressure) is instantaneously lost, and the gross slip at each traction portion. Occurs. For this reason, a hydraulic device is used as the pressing device 20 so as to ensure a necessary pressing force even when the G / N point is passed or during the switching. On the other hand, since the pressure oil supplied into the hydraulic chambers 45a and 45b of the hydraulic pressing device 20 is discharged from a pump driven by a traveling engine, when the engine is stopped, The pressure based on hydraulic pressure cannot be obtained.

  Next, the reason why the configuration (2) is adopted is to keep the torque required to start the engine small. If the pressurizing spring is omitted or a spring having a small elasticity is used, the input disks 10a and 10b and the input disks 10a and 10b of the toroidal-type continuously variable transmission are started when the engine is started. It is only necessary to rotate the member coupled to the. In other words, in addition to the power rollers 12a and 12b and the output disk 11, it is not necessary to rotate the sun gear 22 that rotates with the output disk 11 or the like. For this reason, the mass of the portion that needs to be rotated by the starter motor (cell motor) when the engine is started can be suppressed to a small size, and the energy required for starting the engine can be reduced. However, if the pressurizing spring is omitted or a spring having a small elasticity is used, the traction sections move freely (arbitrarily). Therefore, in the state where the hydraulic pressure in the hydraulic chambers 45a and 45b of the pressing device 20 is not raised as described above, the movements of the traction units are synchronized based on the relative rotation of the disks 10a, 10b, and 11. The tilt angles of the trunnions 17a and 17b cannot be matched.

  Next, the reason why the structure (3) is adopted is that the trunnions 17a and 17b constituting the toroidal continuously variable transmission 1 are smoothly displaced and the toroidal continuously variable transmission is performed. This is to ensure sufficient durability and reliability even when the power transmitted by the machine 1 is increased. In the case of a conventionally known toroidal type continuously variable transmission, a mechanical synchronization mechanism such as a cable, a gear transmission mechanism, a link mechanism or the like is provided between the trunnions, and each trunnion The swing angle (tilt angle) is synchronized with the mechanical type. However, when such a mechanical synchronization mechanism is incorporated, the resistance of the synchronization mechanism becomes a resistance against the oscillating displacement of each trunnion, which is disadvantageous from the viewpoint of smoothly performing the oscillating displacement of each trunnion. become. In addition, for example, the synchronization mechanism using a cable cannot be denied the possibility of the cable being cut with use over a long period of time. Further, the gear transmission mechanism has worn powder generated at the meshing part that damages the traction part. In any case, the possibility cannot be denied, which is disadvantageous in terms of ensuring sufficient durability and reliability.

  For this reason, the mechanical synchronization mechanism is omitted, and the tilt angles of the trunnions 17a and 17b are synchronized only by controlling the supply and discharge of pressure oil into the hydraulic chambers 43a and 43b of the actuators 36 and 36. Things are being researched. However, even if it is the pressure oil supplied and discharged into each of the hydraulic chambers 43a and 43b, as with the pressure oil supplied into the hydraulic chambers 45a and 45b of the pressing device 20, a pump driven by a traveling engine is used. Use what is discharged. Therefore, when the engine is stopped, the hydraulic pressure in the hydraulic chambers 43a and 43b of the actuators 36 and 36 is lost. In this state, the actuators 36 and 36 reliably synchronize the positions of the trunnions 17a and 17b with respect to the axial direction of the pivots 18 and 18 and the tilt angles of the trunnions 17a and 17b. I can't let you.

  The reason why the structure (4) is adopted is to accurately regulate the gear ratio of the toroidal continuously variable transmission 1 in order to realize an infinite speed ratio with respect to the continuously variable transmission. The gear ratio of the toroidal continuously variable transmission 1 when realizing the geared neutral as described above is determined by the number of teeth of the gears 22, 24 to 28 constituting the planetary gear type transmission 2, and the toroidal The actual transmission ratio (actual transmission ratio in the operating state) of the type continuously variable transmission 1 is determined by the rotational speeds of the input disks 10a and 10b and the rotational speed of the output disk 11 which can be measured by a rotation sensor. It is calculated based on the ratio of On the other hand, the value of the gear ratio of the toroidal continuously variable transmission 1 has a one-to-one correspondence with the number of steps of the stepping motor 38 (the number representing the position, not the number of divisions related to the entire stroke). It is difficult to associate the speed ratio with the number of steps in advance due to processing errors, assembly errors, deformation of each part after the start of use, and the like. On the other hand, the gear ratio of the toroidal continuously variable transmission 1 incorporated in the continuously variable transmission that achieves the geared neutral, which is the subject of the present invention, must be regulated with high accuracy.

  Under such circumstances, as described in Patent Document 9, it is considered that the actual gear ratio and the number of steps are associated (learned) and stored in the controller. In this case, as the transmission ratio of the toroidal-type continuously variable transmission 1 that is learned and stored by the controller, it is common to adopt a transmission ratio that realizes the geared neutral (G / N). . This is because the gear ratio for realizing the geared neutral needs to be regulated with high precision, and every time a vehicle equipped with a continuously variable transmission stops, the speed ratio of the continuously variable transmission is It is in a neutral state and appears frequently, so it is suitable as a learning point. Based on such a learning function, immediately after the engine is started, even if the surface pressure of each traction part is insufficient, the posture by the recess cam 39 is supported by the trunnion 17a provided with the recess cam 39. The controlled power roller 12a is adjusted to a gear ratio that realizes the geared neutral. On the other hand, the remaining (three in the illustrated example) power rollers 12b that are not subjected to posture control by the recess cam 39 are not necessarily adjusted to a gear ratio that realizes the geared neutral.

  The reason for adopting the structure (5) is to reduce the size and weight of the continuously variable transmission including the toroidal continuously variable transmission 1 and to simplify the gear ratio control. A gear ratio control valve 37, a stepping motor 38, a recess cam 39, etc. are provided for each trunnion 17a, 17b, and the tilt angles of these trunnions 17a, 17b can be controlled separately (but synchronized). Although possible, not only does the space for providing the members 37 to 39 and the like increase, but also the control for appropriately controlling the plurality of stepping motors 38 becomes troublesome. For this reason, only one set of the transmission ratio control valve 37 and the stepping motor 38 is provided, and the posture of any one trunnion 17a is changed to the spool of the transmission ratio control valve 37 through the recess cam 39 and the link arm 44. 40 (or the sleeve 41) is fed back.

  When such a structure is adopted, the tilt angles of all the trunnions 17a and 17b are synchronized with each other if all of the traction portions related to the power rollers 12a and 12b are in an appropriate power transmission state. It is done. Even if the tilt angles of some of the trunnions 17a and 17b are slightly different from the tilt angles of the other trunnions 17a and 17b, the tilt angles of the trunnions 17b are different from those of the other trunnions 17a and 17b. It corresponds to the tilt angles of 17a and 17b. The operation of matching the tilt angles in this way is performed by stabilizing the unstable state, in other words, by naturally swinging the trunnion 17b in a direction that minimizes the energy applied to the trunnion 17b. However, with respect to any one trunnion 17a provided with the precess cam 39, as long as the hydraulic pressure is introduced into the hydraulic chambers 42a and 42b of the actuator 36 attached to the trunnion 17a, the precess cam 39 is inclined. Since the turning angle is regulated by the state of the gear ratio control valve 37, the tilting angle of the one trunnion 17a does not naturally swing to stabilize the unstable state as described above. The tilt angle of the single trunnion 17a is a value corresponding to the number of steps of the stepping motor 38 that regulates the open / closed state of the speed ratio control valve 37 until it gets tired.

  In addition, due to the structure of the oil supply passage, the hydraulic pressure in the hydraulic chambers 43a and 43b of the actuators 36 and 36 rises after the engine is started (the thrust load applied to the actuators 36 and 36 can be supported by the power transmission). Compared to the timing of rising (to a degree), the hydraulic pressure in the hydraulic chambers 45a and 45b of the pressing device 20 rises (rising to the extent that power can be transmitted in each traction portion) is slightly delayed. Such a difference in the timing at which the hydraulic pressure rises is caused by the distance between the hydraulic power source and each of the actuators 36 and 36 and the pressing device 20, the difference in the structure of the oil supply passage for introducing the pressure oil, and the like. That is, since each of the actuators 36 and 36 is provided in an actuator body fixed in the casing 13, an oil supply passage for introducing hydraulic pressure into the hydraulic chambers 43a and 43b of the actuators 36 and 36 is provided. The structure is simple and the distance from the speed ratio control valve 37 can be easily shortened. On the other hand, the pressing device 20 has a structure that rotates together with the input shaft 3 and the input rotary shaft 5, so that the structure for introducing hydraulic pressure into the hydraulic chambers 45 a and 45 b of the pressing device 20 is complicated. Therefore, the distance from the hydraulic control valve tends to be long. For this reason, as described above, the timing at which the hydraulic pressure in the hydraulic chambers 45a and 45b of the pressing device 20 rises slightly behind the timing at which the hydraulic pressure in the hydraulic chambers 43a and 43b of the actuators 36 and 36 rises.

  Based on the above assumptions, the problem to be solved by the present invention will be specifically described. When the engine is stopped, both the hydraulic pressure in the hydraulic chambers 43a and 43b of the actuators 36 and 36 and the hydraulic pressure in the hydraulic chambers 45a and 45b of the pressing device 20 are lost. In this state, if the engine is started with both the low speed and high speed clutches 30 and 33 disconnected, before the hydraulic pressure in the hydraulic chambers 43a, 43b, 45a, and 45b sufficiently rises. The power rollers 12a and 12b start power transmission between the disks 10a, 10b and 11. However, in this state, the traction portion relating to each of the power rollers 12a and 12b slipped considerably (only a very small part of the power transmitted to both the input disks 10a and 10b is transmitted to the output disk 11). It becomes a state. In this state, the thrust loads (2Ft) applied to the trunnions 17a and 17b that rotatably support the power rollers 12a and 12b are not supported by the actuators 36 and 36, respectively. 17a and 17b are in a state that can be displaced almost freely in the axial direction of the pivots 18 and 18 provided at both ends.

  In this state, when a tangential force acts on each traction portion based on the relative rotation between the respective disks 10a, 10b, and 11, as is widely known in the technical field of toroidal continuously variable transmissions, The trunnions 17a and 17b that rotatably support the power rollers 12a and 12b are displaced in a direction in which the gear ratio of the toroidal-type continuously variable transmission 1 is in a maximum deceleration state. Even in this state, if the slip of the traction portion of the power roller 12a supported by the one trunnion 17a provided with the precess cam 39 is large, the remaining three trunnions 17b are not yet moved before the power roller 12a reaches the maximum deceleration state. There is a possibility that the supported power roller 12b reaches the maximum deceleration position. In this state, even if the tilt angle of the one trunnion 17a is controlled to be a value commensurate with the gear ratio for realizing the geared neutral state based on the learning function described above, the remaining 3 The tilt angle of each trunnion 17b may remain at a value commensurate with the maximum deceleration state. That is, at the moment when the control is started, the difference between the position of the one power roller 12a and the position for realizing the geared neutral is the position of the three power rollers 12b and the geared neutral. There is a possibility that it will be much smaller than the deviation from the position for realizing the above. In this case, even if the one power roller 12a is in the position for realizing the geared neutral, the three power rollers 12b are on the deceleration side than the position for realizing the geared neutral. Exists in a position greatly deviated.

  In the state where the engine is started, the shift lever for switching the operation state is switched to the neutral position (N range) or the parking position (P range). In the state where the shift lever is switched to these two positions, the continuously variable transmission does not transmit power, so both the low speed and high speed clutches 30 and 33 are disconnected. Further, since the toroidal continuously variable transmission 1 does not need to transmit power, it is not necessary to introduce hydraulic pressure into the hydraulic chambers 45a and 45b of the pressing device 20. That is, immediately after starting the engine, when the position of the shift lever is in the N range or the P range, the surface pressure of each traction portion remains small. Accordingly, when no measures are taken as it is, if the position of the one power roller 12a and the position of the three power rollers 12b are greatly deviated as described above, this deviation is eliminated as it is. There is a possibility that it will remain untouched.

  In spite of such a state, when the driver performs an operation for starting the vehicle, specifically, the shift lever is switched to the forward position (D range) or the reverse position (R range). Then, the low speed clutch 30 is connected, and the pressing force generated by the pressing device 20 is further increased. Then, the toroidal continuously variable transmission 1 is operated in a state where the surface pressure of each of the traction portions is increased to a level that allows large power transmission. Then, an excessive slip may occur in a traction portion related to the power roller 12a supported by the one trunnion 17a with a high surface pressure. That is, as described above, if the traction portion related to the one power roller 12a is more slippery than the traction portions of the remaining three power rollers 12b, the rotation of the two input disks 10a and 10b based on the start of the engine is performed. Accordingly, the posture of each of the power rollers 12a and 12b tends to be different between the one power roller 12a controlled by the recess cam 39 and the remaining three power rollers 12b as described above. . In this way, the pressing device 20 is generated while the speed ratio (tilt angle) is different between the one power roller 12a controlled by the recess cam 39 and the remaining three power rollers 12b. When the pressing force is increased and the transmission of power between the input disks 10a and 10b and the output disk 11 is started, the toroidal continuously variable transmission 1 has a large number of the remaining three The engine is operated in a state commensurate with the gear ratio of the power roller 12b (for example, a maximum deceleration state). For this reason, after the engine is started, if the shift lever is switched to the D range or the R range in the state as it is, a gross slip may occur in the traction portion of the toroidal continuously variable transmission 1. .

  Specifically, when one D-range is selected, the one power roller 12a is in a position that realizes a gear ratio slightly lower than the gear ratio (G / N point) corresponding to the geared neutral. When the R range is selected, the position is displaced to a position where the speed ratio on the high speed side is realized slightly from the G / N point. In any case, when the shift lever is switched to the travel position, one power roller 12a supported by the one trunnion 17a is displaced to a position near the G / N point. On the other hand, the remaining plurality (three in the case of the structure shown in FIGS. 4 to 5) of the power rollers 12b are not controlled by the recess cam 39, so that they remain in their positions (for example, in the maximum deceleration state). Stay in the same position). In this state, when the hydraulic pressure in the hydraulic chambers 45a and 45b of the pressing device 20 rises and the surface pressure of each traction portion rises, the toroidal continuously variable transmission 1 is operated with the maximum reduction ratio, for example. . The reason for this is that the total area of the traction portions related to the remaining three power rollers 12b is larger (three times) than the area of the traction portion related to the one power roller 12a, and the remaining three power rollers 12b. This is because priority is given to the gear ratio. In this state, gloss slip occurs in the traction portion related to the one power roller 12a.

  In addition, the gross slip generated as described above becomes increasingly significant. This point will be described with reference to FIG. As described above, the toroidal-type continuously variable transmission 1 in the state where gross slip is generated in the traction portion related to the one power roller 12a is on the speed reduction side (for example, the maximum speed reduction) with respect to the gear ratio realizing geared neutral. Ratio). On the other hand, the controller for controlling the switching state of the transmission ratio control valve 37 at the moment when a range (for example, D range or R range) for traveling is selected by the shift lever is the toroidal type continuously variable transmission. An instruction is given to set the gear ratio of the machine 1 to a value that realizes the geared neutral state. Therefore, in this state, the controller changes the gear ratio of the toroidal continuously variable transmission 1 to the higher speed side based on the difference between the actual gear ratio of the toroidal continuously variable transmission 1 and the command value. Give instructions to do so.

  As a result, the trunnion 17a supporting the one power roller 12a is displaced to the higher speed side, and the slip ratio (creep) of the traction portion related to the one power roller 12a is further increased. That is, the slip rate and traction coefficient of the remaining three power rollers 12b that transmit power at the maximum deceleration position are at the position a in FIG. The slip ratio and the traction coefficient are present at the point b in the figure, and based on the above-mentioned instruction to change to the higher speed side, as shown by the arrow α in the figure, the slip ratio becomes higher. Along with this, the traction coefficient decreases. As a result, a significant slip (gross slip) occurs in the traction portion related to the one power roller 12a. In this state, the transmission ratio of the toroidal type continuously variable transmission remains fixed at the maximum deceleration side and cannot be adjusted. Further, when the gloss slip as described above occurs, the durability of not only the peripheral surface of the single power roller 12a but also the side surfaces in the axial direction of the input disk 10a (10b) and the output disk 11 is significantly reduced. End up.

  Patent Document 5 describes a technique for restricting the position of each power roller to the maximum deceleration side at the time of starting the engine for the purpose of reducing the burden on the starter motor at the time of starting. Patent Document 5 describing such a technique does not describe the structure of a pressing device for ensuring the surface pressure of the traction portion, the presence or absence of a pressurizing spring, and the like. However, since the technology is based on the premise that the speed ratios (trunion tilt angles) of the power rollers are synchronized, use at least a spring having a sufficiently large elasticity as a pressurizing spring, or a mechanical type It is considered that a synchronization mechanism is provided. In the case of the prior art described in Patent Document 5 as described above, there is an effect from the viewpoint of preventing the occurrence of gloss slip based on the asynchronousness of each power roller, but the load reducing effect of the starter motor is omitted. Or inferior to the case where the elasticity is extremely small. Furthermore, the gear ratio of the toroidal-type continuously variable transmission at the start of the engine is a value greatly deviating from the value for realizing geared neutral when the vehicle is started. For this reason, if the shift lever is switched to the running state immediately after the engine is started, an excessive load is applied to the continuously variable transmission at the moment of switching, and any part is damaged or the engine just started is stopped ( There is also a possibility that

JP 7-20569 A Japanese Patent Laid-Open No. 11-166605 JP 2007-298098 A JP 11-63146 A JP 2000-346190 A JP 2009-30749 A JP 2004-308553 A JP 2006-283800 A JP 2002-89678 A

  In view of the circumstances as described above, the present invention can sufficiently reduce the burden on the starter motor for starting the engine with respect to the continuously variable transmission that can change the transmission gear ratio to infinity. It was invented to realize a structure in which excessive slip does not occur in the traction section.

  A continuously variable transmission according to the present invention includes a toroidal continuously variable transmission and a planetary gear unit disposed between an input member connected to an output shaft of an engine as a drive source and an output member connected to a driven portion. . Of these, the input member is connected to the input portion of the toroidal-type continuously variable transmission, and two of the three connection portions that can be connected to the power transmission member existing in the planetary gear unit. The input member and the output portion of the toroidal continuously variable transmission are connected to the connecting portion, and the output member is connected to the remaining connecting portion so as to be able to transmit power. Then, by adjusting the gear ratio between the input disk and the output disk of the toroidal-type continuously variable transmission, the rotation direction of the output member is stopped while the input member is rotated in one direction. Can be converted in both directions.

The toroidal continuously variable transmission includes an output disk, an input disk, a plurality of trunnions, a plurality of power rollers, and a pressing device.
Among these, the output disk has an output-side curved surface that is a toroidal curved surface.
The input disk is supported concentrically with the output disk in a state where the input-side curved surface which is a toroidal curved surface is opposed to the output-side curved surface and capable of relative rotation with respect to the output disk.
Each trunnion is arranged so as to be able to swing and displace about a pivot that is twisted with respect to the central axis of each disk.
Each of the power rollers is supported between the output-side curved surface and the input-side curved surface facing each other in a state in which each power roller is rotatably supported on the inner side surface facing the rotation shaft in each trunnion. Is sandwiched between.
Further, the pressing device secures the surface pressure of the traction portion, which is a rolling contact portion between the peripheral surface of each power roller and each curved surface on the output side and the input side, so that the input disk and the output disk are mutually connected. It pushes in the approaching direction and is hydraulic.

Then, each trunnion is displaced in the axial direction of each pivot by a hydraulic actuator, so that each trunnion is oscillated and displaced about each pivot, so that the gap between the input disk and the output disk is increased. Adjust the gear ratio.
The inclination angle of each trunnion about each pivot is controlled by a transmission ratio control valve that controls the supply and discharge of pressure oil to and from the actuator.
The open / close state of the transmission ratio control valve is switched based on the relative displacement of the pair of valve components. Then, one of these two valve constituent members is provided by a stepping motor, and the other valve constituent member is provided by a displacement transmission mechanism provided between any one of the trunnions. It is configured to be displaced.
Further, the pressure applied to each traction portion by the pressing device without introducing hydraulic pressure into the hydraulic chamber constituting the pressing device is the torque transmitted from the output shaft to the input disk when the engine is started. Is insufficient to transmit to the output disk.

Further, the controller starts the engine with the shift lever for switching the running state switched to the non-running state, and before the shift lever is switched to the running state, the toroidal continuously variable transmission. It is determined whether there is an abnormality in the gear ratio.
A method for determining whether or not there is an abnormality in the gear ratio is not particularly limited. For example, when there is a difference exceeding the threshold between the target speed ratio and the actual speed ratio, and this difference is not resolved for a predetermined time or more, it can be determined that there is an abnormality. The predetermined time in this case is a short time of, for example, 1 second or less, and is determined by design. By setting such a predetermined time, erroneous determination due to detection noise can be prevented. Alternatively, it is possible to determine the presence or absence of the abnormality by outputting a command signal for shifting by a predetermined amount and determining whether or not the gear has been shifted by the predetermined amount. Further, it can be determined by detecting whether or not the gear ratio of the toroidal type continuously variable transmission is in a maximum deceleration state in a state where a command signal to be shifted is not output. Any method can be used as long as it is possible to detect a gear ratio abnormality based on excessive slip in the traction section relating to each of the power rollers, and the above-described methods can be used alone or in combination to determine whether there is a gear ratio abnormality. .

  In order to determine whether or not there is an abnormality in the transmission ratio, for example, as in the invention described in claim 2, in the state where no hydraulic pressure is introduced into the hydraulic chamber constituting the pressing device, any one trunnion is provided. The traction part related to the supported power roller is made to be more slippery than the surface pressure of the traction part related to the power roller supported by another trunnion. If the traction part relating to the power roller supported by any one trunnion provided with the displacement transmission mechanism is made slippery, the gear ratio relating to any one of the power rollers can be changed based on excessive slip. A state different from the speed ratio of the power roller appears (the speed ratio of the toroidal continuously variable transmission as a whole is in a maximum deceleration state in a state where no speed change command signal is output). That is, in this state, the gear ratio of the entire toroidal-type continuously variable transmission is several times, even though no command signal indicating that the maximum deceleration state should be obtained is issued for any one of the power rollers. As a speed change ratio for other power rollers, there is a maximum deceleration state. The reason for the maximum deceleration state is widely known in the technical field of toroidal type continuously variable transmissions as described above, and thus the description thereof is omitted. And it can detect that the said gear ratio is abnormal based on the deviation of the gear ratio and command signal as the whole said toroidal type continuously variable transmission.

  In order to make the traction portion related to the power roller supported by any one trunnion easy to slip, for example, as in the invention described in claim 3, the toroidal continuously variable transmission is connected to each of the above-described toroidal continuously variable transmissions. A half toroidal type in which each of the power rollers is rotatably supported on one side of the trunnion. Then, the amount of protrusion of the power roller supported by any one trunnion from one side surface of the trunnion is determined by the amount of protrusion of the power roller supported by the other trunnion from the side surface of this trunnion. Also make it smaller. If comprised in this way, the surface pressure of the traction part regarding the power roller supported by the said one trunnion can be made low, and this traction part can be made to slip easily.

Alternatively, as in the invention described in claim 4, the pressure receiving area of the actuator for displacing any one trunnion in the axial direction of each pivot, and the other trunnion in the axial direction of each pivot. It is larger than the pressure receiving area of the actuator for displacement. Since the hydraulic pressures introduced into the actuators for displacing each trunnion are equal to each other, the tangential force acting on the traction portion relating to the power roller supported by any one of the trunnions (as described above) is configured. 2Ft) can be increased, and the traction portion related to any one of the power rollers can be slipped more easily than the traction portions of the other power rollers.
The presence or absence of a gear ratio abnormality is determined by the measured value of the tilt angle sensor attached to each trunnion and the actual gear ratio of the toroidal-type continuously variable transmission obtained as the difference between the rotational speeds of the input disk and the output disk. You can also know by comparing.

  Regardless of which method is used to determine whether or not there is a gear ratio abnormality, if it is determined that the gear ratio is abnormal, whether or not the gear ratio is abnormal again after slightly increasing the pressing force. Judging. This operation is repeated until it is determined that the gear ratio is not abnormal. That is, when it is determined that there is an abnormality in the transmission gear ratio, whether the transmission gear ratio is abnormal each time the pressing force generated by the pressing device is increased step by step. The operation of determining whether or not is repeated until it is determined that there is no abnormality in the gear ratio.

When the continuously variable transmission according to the present invention as described above is implemented, it is preferably obtained as a ratio between the rotational speed of the input disk and the rotational speed of the output disk as in the invention described in claim 5. Based on the actual transmission ratio of the toroidal type continuously variable transmission, the number of steps of the stepping motor for adjusting the transmission ratio of the toroidal type continuously variable transmission to a desired value is learned. Provide a learning function to be stored in the controller for control. In this case, after it is determined that there is no abnormality in the gear ratio, the number of steps for adjusting the gear ratio of the toroidal continuously variable transmission to a desired value is learned based on this learning function.
Alternatively, the shift lever can be switched to the running state after it is determined that there is no abnormality in the gear ratio, as in the invention described in claim 6. In other words, as long as it is determined that the gear ratio is abnormal, the shift lever cannot be switched to the running state.

According to the continuously variable transmission of the present invention configured as described above, the burden on the starter motor for starting the engine can be sufficiently reduced, and each traction section is accompanied by an operation for starting the vehicle. It is possible to realize a structure that can reliably prevent excessive slippage from occurring.
First, the burden on the starter motor can be reduced by lowering the pressing force when no hydraulic pressure is introduced into the hydraulic chamber constituting the pressing device. By reducing this pressing force, it is only necessary to rotationally drive only the input disk constituting the toroidal type continuously variable transmission and the members coupled to the input disk when the engine is started. In other words, there is no need to rotationally drive a plurality of power rollers and an output disk and a member that rotates together with the output disk. For this reason, the inertial mass of the portion to be rotationally driven by the starter motor when the engine is started can be greatly reduced, and the burden on the starter motor can be sufficiently reduced.

  Next, to prevent an excessive slip from occurring in accordance with the start operation, the pressing force generated by the pressing device when the gear ratio of the toroidal type continuously variable transmission is determined to be abnormal is determined. It can be achieved by raising it. As described above, each trunnion swings and displaces to the maximum deceleration side around each pivot while the axial thrust load of each pivot is not supported by each actuator. When the engine is started in this state, one trunnion to which the displacement transmission mechanism is attached based on switching of the gear ratio control valve is prepared for starting, and based on learning at the time of previous stop, geared neutral However, the remaining three trunnions may remain at the maximum deceleration position as they are. In this way, while the tilt angle of one trunnion and the tilt angle of three trunnions are greatly deviated, the pressing force is rapidly increased to start transmission of power by the toroidal continuously variable transmission. Then, as described above, a gross slip occurs in the traction portion related to the power roller supported by the one trunnion. In other words, the driver operates the shift lever to the travel position (D range or R range) with the tilt angle of the one trunnion and the tilt angle of the three trunnions greatly deviated. Along with this, when high hydraulic pressure is introduced into the hydraulic chamber of the pressing device and the surface pressure of the traction portion relating to each power roller supported by each trunnion is sufficiently increased, as described above, it is supported by the one trunnion. Excessive slip is generated in the traction section related to the power roller.

  On the other hand, in the case of the present invention, the shift lever is switched to the non-traveling position (N range or P range), and the pressing force is applied while the toroidal continuously variable transmission does not transmit power. In order to raise, the tilt angles of the trunnions that support the power rollers can be matched. Thus, the operation of matching the tilt angles of these trunnions by increasing the pressing force stabilizes the unstable state, in other words, these trunnions in a direction that minimizes the energy applied to these trunnions. Is done by rocking naturally. In a state in which the toroidal continuously variable transmission does not transmit power, the pressing force can be kept low, and the traction portions related to the power rollers supported by the trunnions are easily displaced. Synchronizing the tilt angles of a total of 4 trunnions takes place in a short time.

  In order to synchronize the tilt angles of the respective trunnions, the tilt angle of the one trunnion is set to be equal to the tilt angle of the one trunnion rather than the tilt angle of the one trunnion. Matching to the tilt angles of the three trunnions can be performed in a shorter time. Therefore, when it is determined that there is an abnormality in the gear ratio at the non-traveling position, the supply / discharge control of the pressure oil to the actuator attached to each trunnion is stopped, and each trunnion is connected to each end. If it is possible to displace with a light force in the axial direction of the pivot provided in the part, the one trunnion provided with a displacement transmission mechanism is displaced (to the maximum deceleration side) by the force applied from the traction part. The tilt angles of the three trunnions coincide with the tilt angles of the three trunnions. Thus, after the difference between the tilt angles of the respective trunnions is eliminated, the tilt angle of each of the trunnions is adjusted to the G / N point for starting. Accordingly, the power roller supported by each trunnion immediately synchronizes the input disk and the input disk after the pressing force generated by the pressing device increases with the start operation performed by the driver. Power is transmitted to and from the output disk.

The flowchart for demonstrating the operation | movement of one example of embodiment of this invention. The diagram for demonstrating the state which the traction part regarding each power roller synchronizes based on this operation | movement using a traction curve. Similarly, the flowchart for demonstrating the operation | movement for determining the presence or absence of abnormality of a gear ratio. Sectional drawing which shows an example of the continuously variable transmission used as the object of this invention. AA sectional drawing of FIG. FIG. 3 is a schematic cross-sectional view of a hydraulic control device portion for gear ratio control. The diagram for demonstrating the reason for the asynchronousness of the traction part regarding each power roller to increase.

  An example of an embodiment of the present invention will be described with reference to FIGS. It should be noted that the features of the present invention, including this example, are that each of the power rollers can be started before the vehicle is started after the engine is started even when the engine is started with a low surface pressure of the traction portion. Traction related to the power roller supported by the trunnion provided with the displacement transmission mechanism including the precess cam 39 in the state after the tilt angle of each trunnion supporting the power roller is matched and the driver switches the shift lever to the running state. This is in order to prevent excessive slippage in the part. Regarding the basic configuration of a continuously variable transmission comprising a combination of a toroidal-type continuously variable transmission 1 and a planetary gear type transmission 2, for example, a conventionally known structure shown in FIGS. Since it is the same as that, the overlapping description is omitted. However, the structure of the toroidal type continuously variable transmission 1 will be described with reference to FIGS.

  In the case of the conventional structure shown in FIGS. 4 to 5, a preload spring 46 is provided in the hydraulic chamber 45a constituting the hydraulic pressing device. Even if the spring 46 is omitted or provided, the abutting portions of the components of the toroidal continuously variable transmission 1 rattle during transportation from the continuously variable transmission manufacturing factory to the automobile assembly factory. Only the ones with small elasticity to prevent are provided. Therefore, in a state where the engine is not started and the pump serving as the hydraulic pressure source is stopped, the traction section does not cause excessive slip between the input disks 10a and 10b and the output disk 11. The surface pressure required to transmit power is not applied. When the engine is started, the shift lever is switched to the parking position or the neutral position (P range or N range). In this state, both the low speed side and high speed side clutches 30 and 33 are disconnected. I'm leaning. Therefore, when the engine is started, the starter motor rotates and drives only a part of the members constituting the toroidal continuously variable transmission 1 such as the input disks 10a and 10b, the input rotary shaft 5, and the carrier 23. All you need is enough. However, in this case, there is a possibility that the tilt angle of one trunnion 17a provided with the displacement transmission mechanism including the precess cam 39 and the tilt angle of the other trunnion 17b may not match due to the mechanism as described above. There is. Therefore, in the case of this example, this mismatch is resolved by performing the following control when starting the engine.

First, in step 1 of the flowchart shown in FIG. 1, it is determined whether or not the engine has been started. This determination is made based on whether or not the rotational speed of the input rotary shaft 5 of the toroidal type continuously variable transmission 1 that rotates in synchronization with the crankshaft of the engine is equal to or higher than a predetermined value (for example, 300 min ⁻¹ ). The rotational speed of the input rotary shaft 5 is close to one of the input disks 10a (or 10b) of the two input disks 10a and 10b in order to obtain the actual transmission ratio of the toroidal continuously variable transmission 1. It is calculated | required from the detection signal of the arrange | positioned input side rotation sensor. When the engine is started by the starter motor, the rotation speed of the crankshaft increases from the speed rotated by the starter motor to the idling speed as the engine is ignited (startup completion). Therefore, if a threshold value (for example, 300 min ⁻¹ ) is set between the speed rotated by these starter motors and the idling speed, it can be determined whether or not the engine has started. If it is determined in step 1 that the engine speed is less than the threshold value, it is considered that the engine has not been started, and the process ends as it is (returning to step 1). The rotational speed compared with the threshold value in Step 1 may be any rotational speed as long as it is the rotational speed of the portion that rotates in synchronization with the crankshaft of the engine. For example, the rotational speed of the engine obtained from the tachometer signal can be used.

  If it is determined in step 1 that the rotational speed of the input rotary shaft 5 is equal to or higher than a predetermined value (the engine has started), the process proceeds to the next step 2 where a shift lever for switching the operation state is set. It is determined whether or not the vehicle is in a non-running state (N range or R range). If it is determined in step 2 that the shift lever is not in the non-traveling state (the driving range is switched to the D range or R range), the traction relating to the power rollers 12a and 12b has already been obtained. Since the surface pressure of the portion is sufficiently increased and the tilt angles of the trunnions 17a and 17b are determined to coincide with each other, the process ends.

  On the other hand, if it is determined in step 2 that the shift lever is in a non-traveling state, whether or not there is an abnormality in the gear ratio of the toroidal continuously variable transmission 1 in the next step 3. (Whether there is an excessive slip in the traction portion of any one of the power rollers 12a), in other words, it is determined whether the tilt angles of the trunnions 17a, 17b coincide with each other. Thus, the method for determining whether or not there is an abnormality in the gear ratio of the toroidal type continuously variable transmission 1 is not particularly limited. For example, the determination can be made by directly measuring the tilt angle of each trunnion 17a, 17b by an encoder provided on the pivot 18 portion at the end of each trunnion 17a, 17b. However, such a method may cause a problem in terms of cost and installation space. Therefore, when such a method cannot be employed, for example, the amount of change in the number of steps of the stepping motor 38 (see FIG. 6) matches the amount of change in the gear ratio of the toroidal continuously variable transmission 1. If the determination is made based on whether or not, the above problem can be solved. Such a determination method will be described with reference to FIG.

  First, in step A, a command signal for changing the gear ratio of the toroidal type continuously variable transmission 1 by a predetermined amount is output from the controller to the stepping motor 38. Then, based on switching of the transmission ratio control valve 37 (see FIG. 6), the one trunnion 17a is displaced, and the power roller 12a supported by the trunnion 17a is displaced in the axial direction of the pivot shaft 18. If the four power rollers 12a and 12b are synchronized, the gear ratio of the toroidal-type continuously variable transmission 1 changes by an amount corresponding to the command signal in the determination in step B. Then, the flag indicating that the gear ratio of the toroidal type continuously variable transmission 1 is abnormal is turned off, and the process ends. On the other hand, if the four power rollers 12a and 12b are not synchronized, the gear ratio of the toroidal type continuously variable transmission 1 is changed by an amount corresponding to the command signal in the determination in step B. Therefore, in step D, the process ends with the flag indicating that the transmission ratio of the toroidal continuously variable transmission 1 is abnormal turned ON. As long as this flag is ON, steps 3 and 4 in FIG. 1 are repeated to synchronize the four power rollers 12a and 12b.

  That is, when it is determined by the determination made as described above that there is an abnormality in the gear ratio of the toroidal continuously variable transmission 1, the trunnions 17a constituting the toroidal continuously variable transmission 1 There is a non-negligible difference between the tilt angles of 17b, and an excessive slip exists in the traction portion of at least some of the power rollers 12a and 12b. It is judged. For this reason, in the next step 4, hydraulic pressure is introduced into the hydraulic chambers 45 a and 45 b of the pressing device 20 to slightly increase the pressing force generated by the pressing device 20. The hydraulic pressure introduced into these hydraulic chambers 45a and 45b is not by introducing a sufficiently high pressure from the beginning, but by gradually (stepwise) increasing the pressure. The reason for this is that if a sufficiently high pressure is introduced from the beginning to increase the surface pressure of the power rollers 12a and 12b sufficiently, the trunnions 17a and 17b that support the power rollers 12a and 12b are swung. This is because the displacement is difficult to be performed with a light force, and it is difficult to synchronize the tilt angles of the trunnions 17a and 17b. When carrying out the step 4, the trunnions 17a, 17b are not introduced into any of the hydraulic chambers 43a, 43b of the actuators 36, 36 attached to the trunnions 17a, 17b. In the axial direction of the pivots 18 and 18 provided at both ends of the shaft, it can be displaced with a light force.

  If the pressing force generated by the pressing device 20 is slightly increased in the step 4, the process returns to the step 3 again to determine whether or not the speed ratio of the toroidal continuously variable transmission 1 is abnormal. . When it is determined in step 3 that there is no abnormality in the gear ratio of the toroidal type continuously variable transmission 1, in other words, the tilt angles of the trunnions 17a and 17b coincide with each other. Moves to the next step 5 and performs learning control. On the other hand, if it is determined in step 3 that there is still an abnormality in the gear ratio of the toroidal continuously variable transmission 1, the process proceeds to step 4 again, and the hydraulic chamber 45 a of the pressing device 20. 45b, the hydraulic pressure introduced into 45b is slightly increased, and the pressing force generated by the pressing device 20 is further increased, and then it is determined again whether or not the transmission ratio of the toroidal type continuously variable transmission 1 is abnormal. To do. This operation is repeated until it is determined that there is no abnormality in the gear ratio.

  After it is determined in step 3 that there is no abnormality in the gear ratio of the toroidal continuously variable transmission 1, the learning control performed in step 5 is performed by changing the gear ratio of the toroidal continuously variable transmission 1 as described above. This is because the value for realizing the geared neutral is regulated with high accuracy. If the relationship between the gear ratio of the toroidal-type continuously variable transmission 1 and the number of steps of the stepping motor 38 is known at a certain point, the gear ratio and the step in the entire range of the gear ratio and the number of steps. The relationship with the number can be matched with sufficient accuracy. Therefore, the learning control is not necessarily performed at the gear ratio for realizing the geared neutral. For example, it may be performed when the synchronization is confirmed in the step 3 (in relation to the speed ratio at that time and the number of steps), or may be performed in the maximum reduction ratio portion. Further, the timing for performing learning control is not limited to once. For example, after the synchronization is confirmed, the gear ratio of the toroidal type continuously variable transmission 1 is adjusted to a value capable of realizing the geared neutral, and then the learning control is performed again to change the gear ratio to realize the geared neutral. You may carry out at a specific time (G / N point).

  In any case, the traction section relating to the one power roller 12a is provided with the remaining three power rollers 12b so that the transmission ratios of the four power rollers 12a and 12b can be reliably synchronized as described above. It is more slippery than the traction part. That is, the toroidal-type continuously variable transmission 1 incorporated in the continuously variable transmission of the present example exists between the axial side surfaces of the pair of input disks 10a and 10b and the axial side surfaces of the integrated output disk 11. A pair of trunnions 17a and 17b and power rollers 12a and 12b are provided, one for each pair of cavities to be formed, which is a double cavity type. Among these four power rollers 12a and 12b, the displacement transmission The traction portion related to the power roller 12a supported by one trunnion 17a provided with a mechanism is made to be more slippery than the traction portion related to the power roller 12b supported by the remaining three trunnions 17b. Specifically, the amount of protrusion (support height) of the power roller 12a from the inner surface of the one trunnion 17a is determined from the amount of protrusion of the power roller 12b from the inner surface of the remaining three trunnions 17b. Is slightly lower (for example, about several μm to several tens of μm). The relationship between the behavior of these three trunnions 17b (direction of axial displacement and swing displacement) and the behavior of the one trunnion 17a is always the same. The reason for this is that if there is a large difference in the tilt angles of the trunnions 17a and 17b with this relationship broken, the tilt angles of the trunnions 17a and 17b cannot be synchronized with each other.

  Therefore, the hydraulic pressure is not introduced into the hydraulic chambers 45a and 45b of the pressing device 20, and the input disks 10a and 10b and the output disk 11 are connected to each other in a state where the pressing device 20 does not generate a sufficient pressing force. When the relative rotation occurs, the power roller 12b supported by the three trunnions 17b is tilted to the maximum deceleration side by the tangential force acting on each traction portion by the mechanism as described above. On the other hand, the power roller 12a supported by the one trunnion 17a acts on the traction portion of the three power rollers 12b even if a tangential force is applied to the traction portion or not. Since it is smaller than the force to be applied, there is a possibility of staying at a position where geared neutral is realized or a portion close to this position. In this way, the driver's start operation (to the D range or R range) with the tilt angle of the one power roller 12a and the tilt angle of the three power rollers 12b largely deviated from each other. When a large hydraulic pressure is introduced into the hydraulic chambers 45a, 45b of the pressing device 20 and the pressing force generated by the pressing device 20 increases, as described above, the toroidal continuously variable transmission 1 Is operated at a gear ratio commensurate with the tilt angle of the three power rollers 12b. As a result, excessive slippage occurs at the contact portion between the peripheral surface of the single power roller 12a and the axial side surfaces of the disks 10a (or 10b) and 11.

  On the other hand, in the case of the structure of this example, before performing the start operation (operation for switching the shift lever to the D range or the R range) (while the shift lever exists in the N range or the R range). Further, in step 4, in order to gradually increase the pressing force generated by the pressing device 20, the tilt angle of the trunnion 17a that supports the one power roller 12a and the three power rollers 12b are supported. The deviation from the tilt angle of the trunnion 17b is reduced or eliminated. That is, as indicated by an arrow β in FIG. 2, the state of the traction portion of the one power roller 12a approaches from the point c to the point d which is the state of the traction portions of the remaining three power rollers 12b. In a state where the tilt angles of the trunnions 17a and 17b coincide with each other, the traction portions of the power rollers 12a and 12b are in a state of transmitting power without excessive sliding. Therefore, after confirming that the tilt angles of the trunnions 17a and 17b coincide with each other, that is, that there is no abnormality in the gear ratio of the toroidal continuously variable transmission 1, the start operation (the shift lever is set to D In other words, the shift lever cannot be switched between the D range and the R range while the transmission ratio of the toroidal-type continuously variable transmission 1 is abnormal. Keep this shift lever locked.

  Incidentally, the gear ratio of the toroidal-type continuously variable transmission 1 is adjusted to the G / N point, that is, the state of the traction portion of each of the power rollers 12a and 12b, which coincides with the point d in FIG. As indicated by an arrow γ, the operation of displacing toward the G / N point is after confirming that there is no abnormality in the gear ratio of the toroidal-type continuously variable transmission 1, and that the shift lever is N It may be performed while existing in the range or P range, or after switching to the D range or R range, but is preferably performed while existing in the N range or P range. After confirming that there is no abnormality in the gear ratio of the toroidal continuously variable transmission 1, and further adjusting the gear ratio to the G / N point as necessary, the hydraulic chamber of the pressing device 20 The hydraulic pressure in 45a, 45b is the normal value when the shift lever is in the N range or R range (the degree to which the position of each traction part can be prevented from shifting due to vibrations in the engine, etc.). You may return to a small value.

  The present invention includes three or more power rollers, and only the tilt angle of the trunnion (support member) that supports one of the power rollers is mechanically controlled by the recess cam (the servo mechanism is incorporated), and the rest With respect to the position of the plurality of power rollers (the tilt angle of the trunnion), the tangential force acting on the traction portion related to the power roller is matched with the tilt angle of the trunnion supporting the one power roller. If there is, it can be implemented. For example, as long as three power rollers are installed between a pair of input disks and output disks, the invention can be implemented not only in the double cavity type but also in a single cavity type toroidal continuously variable transmission. However, it is assumed that the traction portion related to one power roller incorporating the servo mechanism is more slippery than the traction portions related to the remaining plurality of power rollers in a state where the pressing force of the hydraulic pressing device is insufficient. It becomes. Therefore, for example, when the present invention is implemented with respect to a continuously variable transmission device incorporating a full toroidal type toroidal continuously variable transmission, the diameter of one power roller incorporating a servo mechanism is set to the remaining plurality of power rollers. The diameter is slightly smaller (a few μm to several tens of μm) than the diameter of the power roller. Alternatively, as in the invention described in claim 4, the pressure receiving area of the actuator for displacing any one trunnion in the axial direction of each pivot is set to the other trunnion in the axial direction of each pivot. Make it larger than the pressure receiving area of the actuator for displacement.

DESCRIPTION OF SYMBOLS 1 Toroidal type continuously variable transmission 2 Planetary gear type transmission 3 Input shaft 4 Output shaft 5 Input rotation shaft 6 Transmission shaft 7 Front stage unit 8 Middle stage unit 9 Rear stage unit 10a, 10b Input disk 11 Output disk 12a, 12b Power roller 13 Casing 14 struts 15 rolling bearings 16 support plates 17a, 17b trunnions 18 pivots 19 support shafts 20 pressing devices 21 hollow rotating shafts 22 sun gears 23, 23a carriers 24 planetary gears 25 planetary gears 26 planetary gears 27 ring gears 28 second sun gears 29 Two-carrier 30 Low speed clutch 31 Third sun gear 32 Second ring gear 33 High speed clutch 34 Planetary gear 35 Planetary gear 36 Actuator 37 Gear ratio control valve 38 Stepping motor 39 Princess cam 40 Spool 41 Sleeve 42 Hydraulic source 43a, 43b Hydraulic chamber 44 Link arm 45a, 45b Hydraulic chamber 46 Pressure spring

Claims (6)

A toroidal-type continuously variable transmission and a planetary gear unit are arranged between an input member connected to the output shaft of the engine, which is a driving source, and an output member connected to the driven portion, and the input member is included in this toroidal The input member and the toroidal are connected to the input part of the continuously variable transmission and to two connection parts of the three connection parts that can be connected to the power transmission member, which are present in the planetary gear unit. A transmission ratio between the input disk and the output disk of the toroidal continuously variable transmission. A continuously variable transmission capable of converting the rotation direction of the output member into both directions with the stop state sandwiched between the input member and the input member rotated in one direction,
The toroidal-type continuously variable transmission includes an output disk having an output-side curved surface that is a toroidal curved surface, and an output disk that is concentric with the output-side curved surface in a state where the input-side curved surface that is a toroidal curved surface is opposed to the output-side curved surface. An input disk supported so as to be able to rotate relative to the output disk, and a plurality of trunnions arranged so as to be able to swing and displace about a pivot that is twisted with respect to the central axis of each disk. A plurality of power rollers sandwiched between the output-side curved surface and the input-side curved surface facing each other in a state of being rotatably supported by the trunnion, and the peripheral surfaces of the power rollers, the output side, and the input In order to ensure the surface pressure of the traction part that is a rolling contact part with each curved surface, the input disk and the output disk are pressed in a direction approaching each other. A pressure-type pressing device, and each trunnion is displaced in the axial direction of each pivot by a hydraulic actuator so that each trunnion swings and displaces around each pivot, thereby Adjusting the gear ratio with the output disk, the inclination angle of each trunnion about each pivot is controlled by a gear ratio control valve that controls the supply and discharge of pressure oil to and from the actuator. The open / close state of the transmission ratio control valve is switched based on the relative displacement of the pair of valve constituent members, and one of the valve constituent members is connected to the stepping motor. Thus, the other valve component member is displaced by a displacement transmission mechanism provided between any one of the trunnions. And it is,
The torque transmitted from the output shaft to the input disk when the engine is started is applied to the traction portion by the pressing device without introducing hydraulic pressure into the hydraulic chamber constituting the pressing device. It is not enough to transmit to the disc,
The controller starts the engine with the shift lever for switching the running state switched to the non-running state, and before the shift lever is switched to the running state, the shift of the toroidal continuously variable transmission is changed. It is determined whether or not there is an abnormality in the ratio, and if it is determined that there is an abnormality, it is determined whether or not the transmission ratio is abnormal again after increasing the pressing force generated by the pressing device. A continuously variable transmission having a function.   In a state where no hydraulic pressure is introduced into the hydraulic chamber constituting the pressing device, the traction portion relating to the power roller supported by any one of the trunnions is more slippery than the traction portion relating to the power rollers supported by the other trunnions. The continuously variable transmission according to claim 1.   The toroidal continuously variable transmission is a half toroidal type in which each power roller is rotatably supported on one side surface of each trunnion, and the trunnion of the power roller supported by any one of the trunnions The continuously variable transmission according to claim 2, wherein a protruding amount from one side surface of the power roller is smaller than a protruding amount from one side surface of the trunnion of the power roller supported by the other trunnion.   The pressure receiving area of an actuator for displacing any one trunnion in the axial direction of each pivot is greater than the pressure receiving area of an actuator for displacing the other trunnion in the axial direction of each pivot. The continuously variable transmission according to Item 2. Based on the actual transmission ratio of the toroidal continuously variable transmission obtained as the ratio of the rotational speed of the input disk and the rotational speed of the output disk, the transmission ratio of the toroidal continuously variable transmission is set to a desired value. Learning the number of steps of the stepping motor for adjustment, and having a learning function for storing in a controller for controlling the stepping motor,
After determining that there is no abnormality in the gear ratio of the toroidal continuously variable transmission, the number of steps for adjusting the gear ratio of the toroidal continuously variable transmission to a desired value is determined based on the learning function. The continuously variable transmission according to any one of claims 1 to 4, wherein learning is performed.   The continuously variable transmission according to any one of claims 1 to 5, wherein the shift lever can be switched to a running state after it is determined that there is no abnormality in the gear ratio.

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