JP2008014357A - Continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a structure including an operation mode capable of outputting motive power input from a driving source without passing through a toroidal type continuously variable transmission 10 with a simple structure. <P>SOLUTION: The continuously variable transmission is equipped with a low speed mode for connecting a low speed clutch 14 and cutting off connection of a high speed clutch 15, and a high speed mode for cutting off the connection of the low speed clutch 14 and connecting the high speed clutch 15. Further, other than these low speed and high speed modes, the transmission is equipped with a bypass mode for operating with both the clutches 14 and 15 of low speed clutch 14 and the high speed clutch in connected states. In this bypass mode, all of the motive power input from the driving source to the continuously variable transmission is output via first to third planetary gear transmissions 11 to 13, and motive power is not transmitted to the toroidal type continuously variable transmission 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement of a continuously variable transmission incorporating a toroidal type continuously variable transmission, which is used as an automatic transmission for a vehicle (automobile), for example, and can improve efficiency, and can be powered by a toroidal type continuously variable transmission. Even when a state where it is impossible to transmit is generated, a structure capable of performing necessary output (running) is realized.

  For example, the use of a toroidal-type continuously variable transmission as an automatic transmission for automobiles is described in many publications such as Patent Document 1, Non-Patent Documents 1 and 2, and is partially implemented and well known. . In addition, a toroidal continuously variable transmission and a gear-type differential mechanism (planetary gear) are used to increase the fluctuation range of the variable speed ratio {speed ratio (reduction ratio), speed ratio (speed increase ratio) = 1 / speed ratio}. A continuously variable transmission combined with a transmission (type transmission) is also widely known, for example, as described in Patent Documents 2 to 5. Among them, Patent Documents 2 and 5 describe a mode in which power is transmitted only by a toroidal type continuously variable transmission (low speed mode), and main power is transmitted by a planetary gear type transmission which is a differential mechanism. A continuously variable transmission having a mode (high-speed mode) that realizes a so-called power split state in which a variable speed ratio is adjusted by a continuously variable transmission is described. Further, in Patent Document 3, the rotational speed ratio of the toroidal continuously variable transmission is set to a predetermined value (GN value, GN point), so that the rotation state of the output shaft is stopped while the input shaft is rotated in one direction. A continuously variable transmission having a mode (low speed mode) capable of realizing a so-called geared neutral state (GN state) and a mode (high speed mode) for transmitting power only by the toroidal type continuously variable transmission is described. Yes. Patent Documents 4 and 5 describe a continuously variable transmission having a mode for realizing a geared neutral state (low speed mode) and a mode for realizing a power split state (high speed mode).

  Of these continuously variable transmissions, in the case of a structure equipped with a mode capable of realizing a geared neutral state, the rotational state of the output shaft is stopped by adjusting the variable speed ratio of the toroidal continuously variable transmission. Since it can be switched between forward rotation and reverse rotation across the state, the starting device such as a torque converter and a starting clutch can be omitted, and the automatic transmission can be reduced in size and weight. At the same time, it is not necessary to travel in a state where the torque converter is not locked up or in a state where the start clutch is in a half-clutch state. For this reason, the power from the engine that is the drive source can be efficiently transmitted to the output shaft, and thus the wheels (tires), and the starting performance can be improved (a feeling of direct start with excellent response feeling). can get). Further, in the case of a structure having a mode capable of realizing the power split state, a part of the power can be sent to the output shaft by bypassing the toroidal continuously variable transmission. In other words, compared to the power applied to the input shaft, the power passing through the toroidal continuously variable transmission can be kept low. The durability of the toroidal continuously variable transmission is improved, and the continuously variable transmission as a whole It is possible to improve transmission efficiency and increase allowable transmission power.

  Patent Document 6 describes a continuously variable transmission as shown in FIG. In the case of the structure shown in FIG. 5, the toroidal type continuously variable transmission 1 and the first to third planetary gear type transmissions 2 to 4 are connected to the low speed and high speed clutches 5 and 6 and the engine direct coupling clutch. 7 is combined. Of these, the engine direct coupling clutch 7 is connected, and the power input from the engine to the input shaft 8 is directly applied to the output shaft 9 with the low speed and high speed clutches 5 and 6 disconnected. The transmission operation mode (engine direct connection mode) is realized. In such an operation mode, the variable speed ratio between the input shaft 8 and the output shaft 9 is fixed to a predetermined value (in the case of FIG. 5, the transmission ratio is 1). In this state, since no power is input to the toroidal continuously variable transmission 1, the transmission efficiency can be improved accordingly. Further, in addition to such an improvement in transmission efficiency, even when an unexpected abnormality occurs such that power transmission cannot be performed by the toroidal-type continuously variable transmission 1, by switching to the engine direct connection mode, Power can be output from the output shaft 9.

  However, in the case of the structure described in Patent Document 6 as described above, in addition to the low-speed and high-speed clutches 5 and 6 that realize the low-speed mode and the high-speed mode, the above-described engine direct connection mode is realized. Only the engine direct coupling clutch 7 is required. For this reason, the structure of the continuously variable transmission is complicated by the necessity of the engine direct coupling clutch 7 as described above, which increases the cost and hinders the reduction in size and weight.

JP 2001-317601 A JP 11-63146 A Japanese Patent Laid-Open No. 9-210191 JP 2000-220719 A JP 2005-291486 A JP 2003-4117 A Motoo Aoyama, “Bessed Best Car Red Badge Series 245 / A book that understands the latest mechanics of cars”, Sangensha Co., Ltd./Kodansha Co., Ltd., December 20, 2001, p. 92-93 Hirohisa Tanaka, “Toroidal CVT”, Corona Inc., July 13, 2000

  In view of the circumstances as described above, the present invention realizes a structure having an operation mode capable of outputting power input from a drive source (for example, an engine) without passing through a toroidal continuously variable transmission with a simple configuration. Invented as much as possible.

The continuously variable transmission of the present invention is a combination of a toroidal continuously variable transmission and a planetary gear type transmission via a clutch device (clutch, brake) as in the case of conventionally known continuously variable transmissions. Become.
Of these, the clutch device is connected when realizing the first mode (for example, the low-speed mode) for increasing the reduction ratio and disconnected when realizing the second mode (for example, the high-speed mode) that is also reduced. A first clutch (for example, a low speed clutch) that is connected to realize the second mode (high speed mode) and disconnected when the first mode (low speed mode) is realized. It consists of two clutches (for example, a high speed clutch).
The clutch device is provided with a controller for switching the connection / disconnection state of the first and second clutches as required. The controller switches the shift state to one of the first mode (low speed mode) and the second mode (high speed mode).

  Note that mode switching (switching of the power transmission path) between the first mode (low speed mode) and the second mode (high speed mode) is performed by changing the variable speed ratio of the continuously variable transmission. It is performed in a state adjusted to values (mode switching point, rotation synchronization point) that can be realized in both the mode (low speed mode) and the second mode (high speed mode). That is, when viewed from the toroidal continuously variable transmission, the variable speed ratio of the toroidal continuously variable transmission is adjusted to a value corresponding to a mode switching point that can be realized in both modes. Then, with the variable speed ratio of the toroidal type continuously variable transmission (and thus the variable speed ratio of the continuously variable transmission) adjusted to a value corresponding to the mode switching point (and thus the mode switching point), The first mode (low speed mode) and the second mode (high speed mode) are switched by switching the connection / disconnection state of the first and second clutches (both low speed and high speed clutches). The variable speed ratio of the continuously variable transmission can be continuously changed before and after switching to).

In particular, in the continuously variable transmission of the present invention, in addition to the first and second modes (low speed and high speed modes), the first clutch (low speed clutch) and the second clutch (high speed) A third mode (for example, a bypass mode) in which the operation is continued while both clutches are connected (simultaneously). In order to realize such a third mode, for example, the controller is provided with a function of (simultaneously) connecting both such clutches.
In this third mode (bypass mode), the toroidal continuously variable transmission is operated with the variable speed ratio corresponding to the mode switching point. That is, the variable speed ratio of the continuously variable transmission is fixed to the mode switching point, which is a value that can be realized in both the first mode (low speed mode) and the second mode (high speed mode). In this state (in a state where the speed change ratio remains unchanged at the mode switching point), the operation is continued. In such a third mode (bypass mode), all the power input from the drive source (for example, engine) to the continuously variable transmission is output via the planetary gear type transmission, and the toroidal type In the continuously variable transmission, power is not transmitted.

In the case of implementing the continuously variable transmission of the present invention as described above, preferably, the variable speed ratio of the continuously variable transmission for realizing the third mode (bypass mode) as described in claim 2. That is, the mode switching point is set to 1 or less (a deceleration side including a constant speed) as a speed increase ratio, more preferably 0.8 or less, and still more preferably 0.5 or less. Such a speed increase ratio can be set, for example, by adjusting the reduction ratio of the planetary gear type transmission and the gear ratio of each gear, sprocket, etc. constituting the power transmission mechanism.
According to a third aspect of the present invention, there is provided operating means for (forcibly) connecting the first and second clutches in order to switch to the third mode (bypass mode). Based on the operation of the operation means, the mode can be switched to the third mode.
Such operation means can be operated by the driver, for example, in the vicinity of a shift lever (operating lever, select lever) provided in the driver's seat (in the vehicle) so that the driver can operate as necessary. It is preferable to provide it at a position where it can be operated sometimes.

  Alternatively, as described in claim 4, there is provided an abnormality detecting means for detecting an abnormality of the toroidal type continuously variable transmission. When the abnormality detection means determines that there is an abnormality, the first and second clutches are both connected (automatically and forcibly) to switch to the third mode (bypass mode). Note that the abnormality detecting means is such that, for example, in the controller, the oil temperature, vibration, speed change ratio, etc. of the toroidal-type continuously variable transmission deviates from a normal value (a state in which no abnormality has occurred). It can be configured by providing a function for determining whether or not the threshold value has been exceeded.

Further, when the continuously variable transmission according to the present invention is implemented, preferably, as described in claim 5, each toroidal continuously variable transmission is supported by each support member (trunion) that rotatably supports each power roller. The variable speed ratio is changed by displacing the valve with a hydraulic actuator. Then, in the state switched to the third mode (bypass mode), the hydraulic pressures of the pair of hydraulic chambers constituting the actuator are made equal (the differential pressure between the hydraulic chambers is made zero).
In this case, preferably, as described in claim 6, a control unit for controlling the variable speed ratio of the toroidal type continuously variable transmission is configured so that the supply / discharge state of the pressure oil to each hydraulic chamber of the actuator is controlled. It is assumed that a gear ratio control valve for switching is provided.

  That is, based on the switching of the gear ratio control valve, a difference in hydraulic pressure is generated between a pair of hydraulic chambers constituting the actuator (a differential pressure is generated), and each of the support members according to the differential pressure. Is displaced in the axial direction of the pivot axis. Based on such displacement, the direction of the tangential force acting on the rolling contact portion (traction portion) between the circumferential surface of each power roller and the inner surface of each disk on the input side and output side is changed (side Slip), and the power rollers and then the support members are swung (tilted) around the pivot, thereby changing the speed ratio of the toroidal continuously variable transmission (to the input side disk). The variable speed ratio between the output side disk and the output side disk is adjusted to a desired value.

In the state switched to the third mode, the hydraulic pressures of the hydraulic chambers of the actuator are made equal based on the operation (switching) of the speed ratio control valve for shifting as described above. Such a gear ratio control valve employs a switching valve that can be switched based on the driving of a driving member such as a stepping motor. In addition, such a gear ratio control valve can be an electromagnetic valve (for example, a servo valve, an electromagnetic valve, or the like). It is also possible to adopt a configuration in which pressure oil is directly supplied to and discharged from each hydraulic chamber of the actuator based on such control (regulation of opening and closing) of the solenoid valve.
Further, in any of the configurations, for example, as described in claim 7, the hydraulic chambers of the actuator are communicated with each other (forcibly), or as described in claim 8. By connecting the hydraulic chambers of the actuator to the same hydraulic source (forcibly), the hydraulic pressures of the hydraulic chambers can be made equal (the differential pressure between the hydraulic chambers can be made zero). It should be noted that the hydraulic pressure source in which the hydraulic chambers communicate with each other in this manner may be the same hydraulic pressure. For example, the hydraulic pressure source may be in communication with a drain (hydraulic pressure zero hydraulic pressure source) or may be adjusted to a predetermined pressure. An oil passage leading to the discharge port of the pump may be communicated.

  As described above, in the case of the continuously variable transmission according to the present invention, both the first clutch (for example, a low speed clutch) and the second clutch (for example, a high speed clutch) are connected (simultaneously). A third mode (for example, a bypass mode) in which operation is performed as it is is provided. In such a third mode (bypass mode), all of the power input from the drive source (for example, engine) to the continuously variable transmission is output via the planetary gear transmission, and the toroidal continuously variable transmission. Then power will not be transmitted. For this reason, the transmission efficiency can be improved by operating in the third mode. In addition to such an improvement in transmission efficiency, even if an unexpected abnormality occurs such that power transmission cannot be performed by the toroidal continuously variable transmission, the mode is switched to the third mode (third By operating in the mode, the power input from the engine can be output (via only the planetary gear type transmission). Moreover, in order to realize such a third mode only, the clutch for this third mode {for example, the engine direct coupling clutch 7 (FIG. 5) required in the structure described in Patent Document 6 described above is used. Need not be provided), the structure of the continuously variable transmission can be simply configured, and any increase in cost, size and weight can be prevented.

  Patent Documents 3 and 5 describe a technique for setting the time for simultaneously connecting both the low speed clutch and the high speed clutch at the time of the mode switching in order to smoothly perform the mode switching. However, in the case of the techniques described in each of these Patent Documents 3 and 5, such clutches are connected in a very short time at the time of mode switching. It is not intended to operate in a connected state {while maintaining (continuing) the connected state}.

  Further, as described in claim 2, if the variable speed ratio of the continuously variable transmission that realizes the third mode is set to 1 or less in the speed increase ratio (which increases or decreases in accordance with the final speed reduction ratio, etc.) The vehicle can be started or run only in the third mode even when an unexpected abnormality occurs such that the transmission of power cannot be performed by the toroidal continuously variable transmission. For this reason, for example, when an abnormal noise is heard from the continuously variable transmission or when the intended travel cannot be performed, the driver operates the operation means described in claim 3 to switch to the third mode. Regardless of the above-mentioned abnormality, the vehicle can be evacuated to a safe place such as a road shoulder, or can be driven to the minimum necessary, such as traveling to a repair shop. Further, by switching to the third mode based on the determination by the abnormality detecting means as described in claim 4, the required travel can be continued regardless of the abnormality.

  In the case of a structure that does not have a starting device (torque converter, starting clutch, etc.), such as a continuously variable transmission that can realize a geared neutral state, when switching to the third mode, it is necessary to It is preferable to realize a half-clutch state with both the first and second clutches. If the half-clutch state can be realized in this way, the vehicle can be started in the third mode even in the case of the structure without the starting device. That is, from the neutral state in which both the first clutch and the second clutch are disconnected, the mode is switched to the third mode based on the operation of the operating means (both the first and second clutches). ), The vehicle can be started or run from a stopped state without entering a mode in which the geared neutral state can be realized.

  In addition, when both the first clutch and the second clutch are connected to switch to the third mode as described above, the variable speed ratio of the toroidal type continuously variable transmission is changed to the mode switching point. If it deviates from the value corresponding to, the gear is forcibly shifted to the value corresponding to the mode switching point based on the torque shift. That is, when both the first and second clutches are connected, the rotational speed ratio (rotational speed ratio) of each component (sun gear, ring gear, carrier) of the planetary gear type transmission is the tooth of each component. It is uniquely determined by a value (a value that realizes the mode switching point) according to the number ratio (reduction ratio). The variable speed ratio of the toroidal-type continuously variable transmission is set to the only value (a value corresponding to the mode switching point) that can realize the rotation speed ratio uniquely determined in this way (change in elastic deformation and assembly gap). Etc.) (for example, based on the above).

  For this reason, for example, when the first and second clutches are connected in a state where the variable speed ratio of the toroidal continuously variable transmission is deviated from the value corresponding to the mode switching point, the toroidal continuously variable transmission is performed. Power for shifting (torque shifting) the variable speed ratio of the toroidal type continuously variable transmission to a value corresponding to the mode switching point is input to the machine. In such a state, the power input to the toroidal-type continuously variable transmission is not zero (the power for torque shift is input), and thus a power loss is caused (although slightly). On the other hand, when the first and second clutches are connected in a state where the deviation is large (a state that is extremely different from a value corresponding to the mode switching point), the input to the toroidal continuously variable transmission is performed. The power becomes excessively large and a large load is applied to the engine. When such a load is significant, there is a possibility that the engine will stop (engine stall).

  Therefore, when both the first and second clutches are connected (switched to the third mode), the variable speed ratio of the toroidal continuously variable transmission is adjusted to a value corresponding to the mode switching point. It is preferable to do this. When the first and second clutches are connected in the state adjusted to the value corresponding to the mode switching point in this way, the power input from the engine is supplied to the toroidal continuously variable transmission. It is output without intervention (through only the planetary gear type transmission). In such an ideal state as the third mode, the hydraulic pressures of a pair of hydraulic chambers constituting an actuator for displacing each support member (trunnion) supporting each power roller are equal to each other. (Differential pressure becomes 0). Therefore, in the case of the present invention, as described in claims 5 to 8, the actuator is configured in the state switched to the third mode (the state where both the first and second clutches are connected). The hydraulic pressures of the pair of hydraulic chambers are made equal (the differential pressure is set to 0).

  If the hydraulic pressures are made equal in this way, even if the variable speed ratio of the toroidal continuously variable transmission deviates from the value corresponding to the mode switching point, the variable speed ratio changes to a value corresponding to the mode switching point. (Can eliminate the deviation). That is, when the hydraulic pressures in the hydraulic chambers are equal, the support members (trunnions) are displaced in the axial direction and swing based on the power applied to the toroidal continuously variable transmission (power for torque shifting). The variable speed ratio of the continuously variable transmission is changed (shifted) to a value corresponding to the mode switching point. For this reason, even when, for example, due to an electrical abnormality (for example, disconnection) or the like, the variable speed ratio of the toroidal continuously variable transmission cannot be adjusted to a value corresponding to the mode switching point, the hydraulic pressure between the hydraulic chambers can be reduced. By equalizing, the variable speed ratio of the toroidal type continuously variable transmission can be changed to a value corresponding to the mode switching point. As a result, even in a state where the variable speed ratio cannot be adjusted, the hydraulic pressure is made equal as described above, and the mode is switched to the third mode (the first and second clutches are connected) as described above. It is possible to perform the minimum necessary driving.

  FIG. 1 shows an example of an embodiment of the present invention. The continuously variable transmission of this example includes a toroidal-type continuously variable transmission 10 and first to third planetary gear type transmissions 11 to 13 between a input shaft 8 and an output shaft 9 at a low speed as a clutch device. And high-speed clutches 14 and 15 are combined. Then, in the low speed mode state in which the low speed clutch 14 is connected, the input shaft 8 is rotated based on the adjustment of the variable speed ratio (speed ratio, speed ratio) of the toroidal-type continuously variable transmission 10. In this state, the output shaft 9 is stopped in a state where the gear ratio is infinite (speed ratio 0) (geared neutral state, GN state). The input shaft 8 constituting such a continuously variable transmission is rotationally driven by a drive shaft such as an engine crankshaft (not shown) during operation. No starting device such as a torque converter or a starting clutch is provided between the input shaft 8 and the drive shaft.

  The toroidal continuously variable transmission 10 is of a so-called double cavity type in which power is transmitted in two systems parallel to each other, and a pair of input side disks 16a and 16b and an integrated output side. A disk 17 and a plurality of power rollers 18 and 18 (see FIG. 5 described above and FIGS. 3 and 4 described later) are provided. Of these, both the input side disks 16a and 16b are arranged concentrically at positions spaced apart from each other in the axial direction, with one axial side surface, which is a toroidal curved surface, facing each other. That is, of the two input side disks 16a and 16b, one input side disk 16a located on the drive shaft side (left side in FIG. 1) is the front end of the input shaft 8 (on the drive shaft side, FIG. The rotation synchronized with the input shaft 8 is freely supported on the outer peripheral surface. On the other hand, the other input side disk 16b is provided at the rear end portion (right end portion in FIG. 1) of the input shaft 8 via the first carrier 24 constituting the first planetary gear type transmission 11. The coupling is fixed, and the rotation in synchronism with the input shaft 8 can be freely performed. With such a configuration, the input disks 16a and 16b and the first carrier 24 are connected so as to be able to transmit power (synchronized rotation is freely possible).

  The output-side disk 17 has a shape such that the back surfaces of a pair of output-side disks are in contact with each other, and both axial side surfaces are toroidal curved surfaces. Such an output-side disk 17 is formed in a state where the toroid side faces the toroid side surfaces of both the input side disks 16a and 16b around the input shaft 8 between the both input side disks 16a and 16b. The rotation relative to the input shaft 8 is freely provided. Further, each of the power rollers 18 and 18 is sandwiched between the input side disks 16a and 16b and the output side disk 17 between a plurality of axial side surfaces each having a toroidal curved surface. . The speed ratio between the input side disks 16a and 16b and the output side disk 17 can be adjusted by swinging and displacing the power rollers 18 and 18 synchronously.

  Each of the power rollers 18 and 18 rotates and slightly swings on the inner surface of the trunnions 19 and 19 corresponding to the support members described in the claims, for example, as shown in FIGS. It is supported so that it can be moved and displaced. Each of the trunnions 19 and 19 is provided with a swinging displacement about the pivots 20 and 20 that are twisted with respect to the input shaft 8. Further, the trunnions 19 and 19 are displaced in the axial direction of the pivots 20 and 20 by a hydraulic actuator 21, thereby changing a speed ratio between the input side disks 16 a and 16 b and the output side disk 17 ( The variable speed ratio of the toroidal type continuously variable transmission 10 is changed. That is, for example, as shown in FIG. 3A, a pair of hydraulic chambers 23 a and 23 b constituting the actuator 21 are connected to each other based on the switching of the speed ratio control valve 22 that is switched based on the driving of the stepping motor 37. A difference in hydraulic pressure is generated between them (the differential pressure is generated), and the trunnions 19 and 19 are displaced in the axial direction of the pivots 20 and 20 in accordance with the differential pressure. In place of the speed ratio control valve 22 driven by the stepping motor 37, an electromagnetic speed ratio control valve such as a servo valve, an electromagnetic proportional valve, or an electromagnetic switching valve is incorporated, and such an electromagnetic speed ratio is incorporated. A configuration in which pressure oil is supplied to and discharged from the hydraulic chambers 23a and 23b of the actuator 21 based on control of the control valve (adjustment of opening and closing) can also be adopted.

Whichever structure is adopted, based on the displacement of each trunnion 19, 19, the circumferential surface of each power roller 18, 18 and the inner surface of each of the input side and output side disks 16 a, 16 b, 17 The direction of the tangential force acting on the rolling contact portion (traction portion) is changed (side slip is generated). Based on such a change in force, the power rollers 18 and 18 and then the trunnions 19 and 19 are swung (tilted) around the pivots 20 and 20 to thereby form the toroidal type. The variable speed ratio of the continuously variable transmission 10 (the variable speed ratio between the input side disks 16a and 16b and the output side disk 17) is adjusted to a desired value.
Since the structure and operation of such a toroidal-type continuously variable transmission 10 are the same as those of conventionally known toroidal-type continuously variable transmissions, detailed description thereof is omitted.

  Further, the first planetary gear type transmission 11 provided next to such a toroidal type continuously variable transmission 10 is of a double pinion type, and each is rotatably supported by the first carrier 24 to form a pair. The first planetary gears 25a and 25b are meshed with each other, and the planetary gear 25a near the inner diameter is meshed with the first sun gear 26, and the first planetary gear 25b near the outer diameter is meshed with the first ring gear 27. ing. The first sun gear 26 is connected to the output side disk 17 via a hollow rotary shaft 28 so that power can be transmitted (synchronized rotation is freely possible). The hollow rotary shaft 28 is provided concentrically with the first sun gear 26 and the output side disk 17, and a base end portion is coupled and fixed to an inner diameter portion of the output side disk 17, and the first sun gear is mounted at a distal end portion. 26 is fixed.

  Further, the second planetary gear type transmission 12 arranged next to the first planetary gear type transmission 11 as described above and away from the toroidal type continuously variable transmission 10 rotates together with the first carrier 24. The second carrier 29 is provided. In the case of this example, the second carrier 29 and the first carrier 24 are integrally formed, and the first carrier 24 also has a function as the second carrier 29. Each second planetary gear 30 rotatably supported by the second carrier 29 is meshed with a second sun gear 32 fixed to one end portion (front end portion) of the transmission shaft 31. In the case of this example, each first planetary gear 25a located radially inward of each second planetary gear 30 and each first planetary gear 25a, 25b constituting the first planetary gear type transmission 11. Are combined planetary gears called so-called step pinions, which freely combine rotations synchronized with each other. Note that no ring gear is provided around each of the second planetary gears 30.

  A third sun gear 33 constituting the third planetary gear type transmission 13 is fixed to the other end portion (rear end portion) of the transmission shaft 31. A third carrier 34 and a third ring gear 35 that also constitute the third planetary gear type transmission 13 are provided around the third sun gear 33, and a third planet 34 is provided on the third carrier 34. Gears 36a and 36b are rotatably supported. Such a third planetary gear type transmission 13 is also of a double pinion type, like the first planetary gear type transmission 11. The third carrier 34 and the output shaft 9 are connected (coupled) so as to be able to transmit power (synchronously rotate freely).

  Further, the first ring gear 27 and the third carrier 34 constituting the first planetary gear type transmission 11 can be connected to each other so that power can be transmitted via the low speed clutch 14, and the first The three ring gear 35 and a fixed part such as a housing can be freely engaged and disengaged by the high speed clutch 15. Of these, the low speed clutch 14 corresponds to the first clutch described in the claims, and the low speed mode (including the GN state) for increasing the reduction ratio (including the first state described in the claims). The connection is cut off when realizing a high-speed mode (also corresponding to the second mode) which is connected when realizing the mode). The high-speed clutch 15 corresponds to the second clutch described in the claims, and is connected when the high-speed mode is realized and disconnected when the low-speed mode is realized. .

  The low-speed and high-speed clutches 14 and 15 can be switched (controlled) by a controller (not shown). For this purpose, for example, the low-speed clutch and the high-speed clutch 14 are switched by switching the electromagnetic switching valves (not shown) for the low-speed clutch and the high-speed clutch whose energization state is controlled based on the control signal of the controller. The hydraulic oil can be introduced independently into each of the 15 hydraulic chambers. For such low-speed clutch and high-speed clutch electromagnetic switching valves, for example, an electromagnetic valve (spool valve) that displaces the spool based on energization of the solenoid can be employed. Then, based on the displacement of the spools of the electromagnetic switching valves for the low speed clutch and the high speed clutch (opening and closing of the electromagnetic valve), the pressure oil is introduced into the hydraulic chambers of the low speed and high speed clutches 14 and 15. Is switched to switch the connection / disconnection state of the low speed and high speed clutches 14 and 18.

  FIG. 2 shows the relationship between the variable speed ratio (speed increase ratio) of the toroidal type continuously variable transmission 10 and the variable speed ratio (speed increase ratio) of the continuously variable transmission as a whole. In the low-speed mode in which the low-speed clutch 14 is connected and the high-speed clutch 15 is disconnected, the variable speed ratio of the toroidal continuously variable transmission 10 is a value that can realize the GN state, as indicated by the solid line α. As the speed is decelerated from (GN value), the variable speed ratio of the continuously variable transmission as a whole is increased from the stopped state (state where the speed ratio is 0) to the forward direction (+: forward direction). Similarly, as the speed increases from the GN value, the speed is also increased in the backward direction (-: reverse direction) from the stopped state. On the other hand, in the high speed mode in which the high speed clutch 15 is connected and the low speed clutch 14 is disconnected, the speed change ratio of the toroidal continuously variable transmission 10 is increased as shown by the broken line β. The speed ratio of the continuously variable transmission as a whole can be increased (in the forward direction). In such a high speed mode, a power split state in which the power passing through the toroidal type continuously variable transmission 10 can be reduced is realized.

  Further, mode switching between the low speed mode and the high speed mode (switching of the power transmission path) is a value that the variable speed ratio of the continuously variable transmission can be realized in both the low speed mode and the high speed mode. (Mode switching point, rotation synchronization point), that is, in a state adjusted to a in FIG. In this case, when viewed from the toroidal type continuously variable transmission 10, the variable speed ratio of the toroidal type continuously variable transmission 10 corresponds to a value corresponding to the mode switching point a that is a value that can be realized in both modes. 2 is performed in a state adjusted to b in FIG. In this way, the variable speed ratio of the toroidal-type continuously variable transmission 10 (and hence the variable speed ratio of the continuously variable transmission) is adjusted to the value b corresponding to the mode switching point (and thus the mode switching point a). In this state, by switching the connection / disconnection state of the low speed and high speed clutches 14 and 15 (mode switching), before and after switching between the low speed mode and the high speed mode, the continuously variable transmission is The variable speed ratio can be changed continuously.

  In the case of this example, in addition to the low speed mode and the high speed mode as described above, the operation is performed with the clutches 14 and 15 of both the low speed clutch 14 and the high speed clutch 15 being connected. The controller for performing connection / disconnection control of each of the clutches 14 and 15 has a function of realizing a bypass mode (corresponding to the third mode described in the claims). In this bypass mode, the variable speed ratio of the toroidal type continuously variable transmission 10 is operated with the value b corresponding to the mode switching point. In other words, the variable speed ratio of the continuously variable transmission is a value that can be realized in both the low speed mode and the high speed mode, and is fixed to the mode switching point a (the mode switching point a The operation is performed with the speed ratio remaining unchanged. In such a bypass mode, all of the power input to the continuously variable transmission from the engine that is the driving source is output via the first to third planetary gear type transmissions 11 to 13, and the toroidal type The continuously variable transmission 10 does not transmit power. In such a bypass mode, for example, the optimum target speed ratio of the continuously variable transmission (toroidal continuously variable transmission 10) corresponding to the vehicle running state (vehicle speed, accelerator opening, etc.) at that time is the above mode. When it is the switching point a (value b corresponding to the mode switching point), it is switched by the controller.

  In the case of this example, the variable speed ratio of the continuously variable transmission that realizes the bypass mode, that is, the mode switching point a is increased or decreased according to the final reduction ratio, etc., at 1 or less. More specifically, it is set to 0.48. Further, in order to switch to such a bypass mode, an operating means for (forcibly) connecting both the low speed and high speed clutches 14 and 15 is a shift lever (operating lever) provided in the driver's seat (in the vehicle). Near the select lever). The driver can switch to the bypass mode by operating the operation means as required. In the case of this example, an abnormality detecting means for detecting an abnormality of the toroidal type continuously variable transmission 10 is provided. As such an abnormality detection means, for example, the controller causes the oil temperature, vibration, variable speed ratio, etc. of the toroidal-type continuously variable transmission 10 to deviate from normal values (states in which no abnormality has occurred). It is configured by determining whether or not (a preset threshold has been exceeded). When such an abnormality detection means determines an abnormality, the low speed and high speed clutches 14 and 15 are connected (automatically and forcibly) to switch to the third mode (bypass mode). I am trying to do it.

  The abnormality detecting means detects, for example, the temperature (oil temperature) of the lubricating oil (traction oil) circulating in the toroidal type continuously variable transmission 10 by a temperature detecting means (temperature sensor), and the oil temperature is previously detected. When a set threshold value (for example, 200 ° C.) is exceeded, it can be determined that the abnormality has occurred. In such a case, it is considered that excessive slip occurs in the traction portion (rolling contact portion) of the toroidal type continuously variable transmission 10, and the oil temperature rises based on the heat generated by such slip. . Therefore, based on such a determination, the above-described toroidal-type continuously variable transmission 10 does not transmit power (transmits power only by the first to third planetary gear type transmissions 11 to 13). Switch to bypass mode (connect both low speed and high speed clutches 14 and 15). Further, for example, when the vibration of the toroidal-type continuously variable transmission 10 is detected by a vibration detecting means (vibration sensor) and the vibration exceeds a preset threshold value, it can be determined that the abnormality has occurred. In such a case, for example, it is considered that the toroidal continuously variable transmission 10 is damaged, or an abnormality such as foreign matter is mixed.

  The variable speed ratio of the toroidal type continuously variable transmission 10 is obtained from, for example, the ratio of the rotational speeds of the input side disks 16a and 16b and the output side disk 17, and this variable speed ratio exceeds a threshold (for example, mechanical It is also possible to determine that the abnormality has occurred when the value deviates from the range of values that can be realized by design. In such a case, it is considered that an abnormality such as an excessive increase in the rotational speed of the input side disks 16a and 16b has occurred based on the gross slip. In place of the variable speed ratio, it can be determined that the abnormality has occurred when the rotational speed of the output disk 17 or the input disks 16a and 16b exceeds a threshold value.

In addition, in order to adjust the variable speed ratio of the toroidal type continuously variable transmission 10, a gear change command for switching the gear ratio control valves 22, 22a is output from the controller (for example, stepping). The above abnormality also occurs when the toroidal continuously variable transmission 10 is not shifted (the gear ratio is not changed) even though a drive signal is output to the motor 37 or an open / close signal is output to the solenoid valve. Can be determined. In such a case, for example, there is an abnormality in the transmission ratio control valves 22 and 22a constituting the control unit for performing a shift, the drive member (stepping motor 37) for switching the transmission ratio control valves 22 and 22a, and the like. (For example, derailment of the stepping motor 37, etc.) is considered to have occurred. On the other hand, when the toroidal-type continuously variable transmission 10 is shifting (the transmission ratio is changed) even though no shift command is output, the above abnormality occurs. Can be determined. In this case, it is considered that there is a possibility that the gear ratio of the toroidal type continuously variable transmission 10 hunts periodically.
In any case, when it is determined that the abnormality has occurred, the low-speed and high-speed clutches 14 and 15 are (forced) based on the function of the controller to switch to the bypass mode. Connecting.

  Further, in the case of this example, as shown in FIGS. 3 and 4, the hydraulic pressures of the pair of hydraulic chambers 23a and 23a constituting the actuators 21 and 21 are made equal in the state switched to the bypass mode (hydraulic chambers). The differential pressure between them is set to 0). For this reason, for example, in the case of the structure shown in FIG. 3A, the hydraulic chambers 23a of the actuators 21 and 21 are switched based on the switching of the speed ratio control valve 22 in the state of switching to the bypass mode. , 23b are equalized. Specifically, while measuring the hydraulic pressure of each of the hydraulic chambers 23a and 23b with a hydraulic sensor, the hydraulic pressure of each of the hydraulic chambers 23a and 23b is made equal (so that the difference in hydraulic pressure becomes zero). The gear ratio control valve 22 is switched. Further, as shown in FIG. 3B, for example, by opening the normally closed electromagnetic valve 41, the hydraulic chambers 23a, 23b of the actuators 21, 21 are communicated with each other (forcibly), The hydraulic pressures of these hydraulic chambers 23a and 23b can be made equal (the differential pressure is made zero). Furthermore, as shown in FIG. 4, for example, solenoid valves 38 and 38 are used to connect the hydraulic chambers 23a and 23b of the actuators 21 and 21 to the same hydraulic source, for example, a drain 40 having a hydraulic pressure of 0 {FIG. Or it can also be made to communicate with the discharge port {(B) of FIG. 4} of the oil pump 39 adjusted to a predetermined pressure.

  As described above, in the case of the continuously variable transmission of the present example, the bypass mode (third mode) is performed in which the clutches 14 and 15 of both the low speed clutch 14 and the high speed clutch 15 are connected. Mode). In such a bypass mode, all of the power input from the drive source (for example, the engine) to the continuously variable transmission is output via the first to third planetary gear type transmissions 11 to 13, and the toroidal type In the step transmission 10, power is not transmitted. For this reason, the transmission efficiency can be improved by operating in such a bypass mode. In addition to the improvement of the transmission efficiency as described above, even if an unexpected abnormality occurs such that the power transmission cannot be performed by the toroidal type continuously variable transmission 10, for example, the driver may operate the operation means. Or, the operation can be continued by automatically switching to the bypass mode (operating in the bypass mode) based on the determination of the abnormality detection means. That is, the power input from the engine can be output only through the first to third planetary gear type transmissions 11 to 13, and the vehicle is evacuated to a safe place such as a road shoulder regardless of the abnormality. Or you can perform the minimum required traveling such as self-running to a repair shop. In addition, in order to realize such a bypass mode, for example, it is not necessary to provide the engine direct coupling clutch 7 (see FIG. 5) required in the structure described in Patent Document 6 described above. The structure of the transmission can be simply configured, and any increase in cost, size, and weight can be prevented.

  In the case of this example, in order to displace the trunnions 19 and 19 that support the power rollers 18 and 18 in the state where the bypass mode is switched (the low speed and high speed clutches 14 and 15 are connected). The hydraulic pressures of the pair of hydraulic chambers 23a and 23b constituting the actuators 21 and 21 are equal to each other (the differential pressure is set to 0). For this reason, even if the variable speed ratio of the toroidal type continuously variable transmission 10 deviates from the value b corresponding to the mode switching point (see FIG. 2), the variable speed ratio is set to the value b corresponding to the mode switching point. Can be changed (displacement can be eliminated). That is, when the hydraulic pressures in the hydraulic chambers 23a and 23b are equal, the trunnions 19 and 19 are displaced and swung in the axial direction based on the power applied to the toroidal type continuously variable transmission 10 (power for torque shifting). The variable speed ratio of the toroidal continuously variable transmission 10 changes (shifts) to a value corresponding to the mode switching point. For this reason, even when the variable speed ratio of the toroidal continuously variable transmission 10 cannot be adjusted to the value b corresponding to the mode switching point due to, for example, an electrical abnormality (for example, disconnection), the hydraulic chamber 23a. , 23 b are equalized, the variable speed ratio of the toroidal-type continuously variable transmission 10 is changed to a value b corresponding to the mode switching point. As a result, even in a state where the speed change ratio cannot be adjusted in this way, the minimum oil pressure can be obtained by equalizing the hydraulic pressure as described above and switching to the bypass mode (by connecting both the low speed and high speed clutches 14 and 15). You can run as much as possible.

In the above description, the present invention is combined with a toroidal continuously variable transmission and a planetary gear type transmission, and the rotation state of the output shaft is corrected with the input shaft rotated in one direction. A so-called geared neutral state (low speed mode) that can be switched between rotation and reverse, and the planetary gear type transmission transmits the main power and the toroidal continuously variable transmission adjusts the transmission ratio. The case where the present invention is applied to a continuously variable transmission having a mode (high speed mode) for realizing a power split state has been described. However, the present invention combines a toroidal type continuously variable transmission and a planetary gear type transmission, for example, a mode in which power is transmitted only by the toroidal type continuously variable transmission (low speed mode), and a mode in which a power split state is realized. Continuously variable transmission equipped with (high-speed mode), continuously variable transmission equipped with a mode (low-speed mode) that can realize a geared neutral state and a mode (high-speed mode) that transmits power only by a toroidal-type continuously variable transmission It can also be applied to devices. In other words, the toroidal continuously variable transmission and the planetary gear type transmission are combined, and the continuously variable transmission before and after switching between the first mode (for example, the low speed mode) and the second mode (for example, the high speed mode). The present invention can be applied to any structure that can continuously change the change rate ratio. In any structure, the third switching point is operated by connecting both the first clutch (for example, the low speed clutch) and the second clutch (high speed clutch) at the mode switching point. A mode (for example, bypass mode) is realized.
The structure of the toroidal continuously variable transmission may be either a half toroidal type or a full toroidal type.

The half part sectional view showing an example of an embodiment of the invention. The diagram which shows the relationship between the variable speed ratio (speed increase ratio) as the whole continuously variable transmission, and the variable speed ratio (speed increase ratio) of a toroidal type continuously variable transmission. The principal part hydraulic circuit diagram which shows two examples of the structure of the part which performs gear ratio control. The principal part hydraulic circuit diagram which shows two examples of the structure for equalizing the hydraulic pressure of the hydraulic chambers of an actuator. FIG. 6 is a schematic cross-sectional view showing an example of a conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toroidal type continuously variable transmission 2 1st planetary gear type transmission 3 2nd planetary gear type transmission 4 3rd planetary gear type transmission 5 Low speed clutch 6 High speed clutch 7 Engine direct coupling clutch 8 Input shaft 9 Output shaft DESCRIPTION OF SYMBOLS 10 Toroidal type continuously variable transmission 11 1st planetary gear type transmission 12 2nd planetary gear type transmission 13 Third planetary gear type transmission 14 Low speed clutch 15 High speed clutch 16a, 16b Input side disk 17 Output side disk 18 Power roller 19 Trunnion 20 Axis 21 Actuator 22 Gear ratio control valve 23a, 23b Hydraulic chamber 24 First carrier 25a, 25b First planetary gear 26 First sun gear 27 First ring gear 28 Hollow rotating shaft 29 Second carrier 30 Second Planetary gear 31 Transmission shaft 32 Second sun gear 33 Third sun gear 34 Third carrier 35 First Ring gear 36a, 36b the third planetary gear 37 a stepping motor 38 solenoid valve 39 the oil pump 40 drain 41 solenoid valve

Claims (8)

  A toroidal-type continuously variable transmission and a planetary gear type transmission are combined through a clutch device, and this clutch device is connected to realize a first mode for increasing the reduction ratio and is also made smaller. The first clutch that is disconnected when realizing the first mode and the second clutch that is connected when realizing the second mode and disconnected when realizing the first mode In the continuously variable transmission that changes the state of shifting of each of these clutches to change the shifting state to one of the first mode and the second mode. In addition to the first and second modes, a third mode is provided in which the operation is continued while both the first clutch and the second clutch are connected. Characteristic continuously variable transmission   The continuously variable transmission according to claim 1, wherein the speed change ratio of the continuously variable transmission that realizes the third mode is set to 1 or less in terms of the speed increasing ratio.   An operation means for switching to the third mode is provided, and based on an operation of the operation means, switching to the three modes is made possible. Step transmission.   An abnormality detection means for detecting an abnormality of the toroidal continuously variable transmission is provided, and when the abnormality detection means determines that there is an abnormality, it switches to the third mode. The continuously variable transmission described in item 1.   The toroidal-type continuously variable transmission changes the speed ratio by displacing each support member that rotatably supports each power roller by a hydraulic actuator. The continuously variable transmission according to any one of claims 1 to 4, wherein the hydraulic pressures of a pair of hydraulic chambers constituting the actuator are equalized.   The control unit for controlling the variable speed ratio of the toroidal-type continuously variable transmission includes a speed ratio control valve that switches the supply / discharge state of the pressure oil to each hydraulic chamber of the actuator, and is based on the operation of the speed ratio control valve. The continuously variable transmission according to claim 5, wherein the hydraulic pressure in each of the hydraulic chambers is made equal.   The continuously variable transmission according to any one of claims 5 to 6, wherein the hydraulic chambers of the actuator are made to communicate with each other so that the hydraulic pressures of the hydraulic chambers are equalized.   The continuously variable transmission according to any one of claims 5 to 6, wherein each hydraulic chamber of the actuator is connected to the same hydraulic pressure source to equalize the hydraulic pressure of each hydraulic chamber.

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