JP2008215484A - Belt type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt type continuously variable transmission capable of restraining wear and tear of a side surface of a belt, while cutting off the power transmission on the inside of the transmission. <P>SOLUTION: This belt type continuously variable transmission 20 has an input side pulley 24 and an output side pulley 35 respectively engaging with an input shaft 22 and an output shaft 33, the belt 60 wound on these two pulleys 24 and 35 and capable of transmitting mechanical power from the input shaft 22 to the output shaft 33, and a rotary mechanism 40 constituted to be reciprocally rotatable around the input shaft 22 and capable of supporting the belt 60 from the input shaft 22 side, and can cut off the power transmission between the input shaft 22 and the output shaft 33 by supporting the belt 60 by the rotary mechanism 40 by separating from the pulleys. A clutch mechanism 50 is arranged for transmitting rotation of the input shaft 22 to the rotary mechanism 40 by engaging with the input side pulley 24 before the input side pulley 24 contacts with the side surface 66 of the belt 60. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a belt-type continuously variable transmission, and more particularly to a continuously variable transmission capable of interrupting power transmission between rotating shafts.

  A belt-type continuously variable transmission usually has an input-side pulley that engages with an input shaft and rotates integrally, and an output-side pulley that engages with an output side and rotates integrally. A belt is wound around a V-shaped groove formed by the side and output pulleys. The belt type continuously variable transmission changes the gear ratio by changing the groove width (hereinafter referred to as pulley width) on the input and output pulleys and changing the winding diameter of the belt wound around the pulley. I am letting.

  The pulley on the input side of a belt-type continuously variable transmission is generally engaged with a fixed sheave fixed to the input shaft and the input shaft, and is movable with respect to the fixed sheave in the axial direction of the input shaft. The pulley has a sheave, and the pulley width is changed by moving the movable sheave in the axial direction by hydraulic pressure or the like. The output pulley has a fixed sheave fixed to the output shaft and a movable sheave that engages with the output shaft and is movable in the axial direction of the output shaft with respect to the fixed sheave, like the input pulley. The pulley width is variable. The belt-type continuously variable transmission can change the gear ratio by changing the pulley widths at the input and output pulleys.

  In a vehicle equipped with such a belt-type continuously variable transmission, it is desired not to transmit mechanical power from the prime mover to the wheels while the vehicle is stopped. In particular, when the prime mover is an internal combustion engine, it is difficult to switch between operation and non-operation of the internal combustion engine in response to the start and stop of the vehicle, so a power transmission mechanism that transmits mechanical power from the prime mover to the drive wheels However, there is a need for a technique for interrupting power transmission. For example, in the technique described in Patent Document 1 below, it is proposed to provide a clutch device for interrupting power transmission outside the belt-type continuously variable transmission in the power transmission device (for example, Patent Literature 1). 1).

  Patent Document 2 below discloses a technique for interrupting power transmission between the input shaft and the output shaft of the belt type continuously variable transmission. In this belt-type continuously variable transmission, a belt hoisting roller that is rotatable in a forward and reverse direction via a bearing is provided on an input shaft (drive rotation shaft). In this continuously variable transmission, the movable sheave of the input side pulley (drive pulley) is separated from the fixed sheave to the maximum, thereby separating the belt from the movable sheave and the fixed sheave and disengaging the input side pulley and the belt. At the same time, the belt that has been wound around the input pulley is placed on the belt hoisting roller. Thereby, the continuously variable transmission of Patent Document 2 cuts off power transmission between the input shaft (drive rotation shaft) and the output shaft.

Japanese Examined Patent Publication No. 6-67693 JP 2002-161956 A

  By the way, in the technique described in Patent Document 1, since the start clutch device is separately provided outside the output shaft of the belt type continuously variable transmission, the size of the power transmission device including the continuously variable transmission is large. There is a problem of becoming. In addition, since such a starting clutch device is normally driven by hydraulic pressure or electromagnetic force, the energy for driving the starting clutch device is increased every time the starting clutch device is switched between engagement and disengagement. Necessary.

  In the technique described in Patent Document 2, when the input sheave and the belt are engaged, the movable sheave is moved and the belt on the riding roller is sandwiched between the fixed sheave and the input shaft. Since the movable sheave and the fixed sheave rotating together suddenly come into contact with the side surface (flank surface) of the stationary belt, there arises a problem that the side surface of the belt is worn. Since the side surface of the belt is a portion in contact with the input side and output side pulleys during power transmission, the belt type continuously variable transmission needs to prevent the side surface of the belt from being worn as much as possible.

  The present invention has been made in view of the above, and an object of the present invention is to provide a belt-type continuously variable transmission capable of suppressing belt wear while allowing power transmission to be interrupted inside the transmission.

  In order to achieve the above object, a continuously variable transmission according to the present invention is wound around two pulleys respectively engaged with two rotating shafts, and wound around the two pulleys. A belt capable of transmitting mechanical power to the other rotation shaft, a rotation mechanism configured to be rotatable in a forward / reverse direction around the one rotation shaft, and a rotation mechanism capable of supporting the belt from the rotation shaft side; A clutch mechanism capable of transmitting the rotation to the rotation mechanism is provided.

  In the continuously variable transmission according to the present invention, the clutch mechanism can be engaged with the pulley and transmit the rotation of the rotating shaft to the rotating mechanism before the pulley contacts the side surface of the belt.

  In the continuously variable transmission according to the present invention, the continuously variable transmission can be mounted on an automobile, and the two rotating shafts are an input shaft that receives mechanical power from the internal combustion engine, and a drive wheel. The output shaft may output an output of mechanical power.

  In the continuously variable transmission according to the present invention, the rotation mechanism and the clutch mechanism may be provided around the input shaft.

  In the continuously variable transmission according to the present invention, each pulley has a fixed sheave fixed to the rotating shaft and a movable sheave movable in the axial direction of the rotating shaft with respect to the fixed sheave. May be provided between the fixed sheave and the movable sheave, and the clutch mechanism may be provided between the fixed sheave or the movable sheave and the rotation mechanism.

  In the continuously variable transmission according to the present invention, the movable sheave or the fixed sheave may be provided with a cylindrical recess having a rotation axis as an axis so as to accommodate at least a part of the clutch mechanism. it can.

  In the continuously variable transmission according to the present invention, the clutch mechanism is disposed so as to sandwich the friction plate that rotates integrally with the rotating shaft, and mechanical power from the rotating shaft is generated by engaging the friction plate. A friction counter plate capable of being transmitted to the rotation mechanism; and an engagement means for engaging the friction plate with the friction counter plate when the pulley width is smaller than a predetermined width. When engaged, the rotation of the rotation shaft can be transmitted to the rotation mechanism via the friction plate and the friction counterpart plate.

  In the continuously variable transmission according to the present invention, the friction plate and the friction counterpart plate are plate-like members extending substantially orthogonal to the rotation shaft, and the engaging means is provided on the pulley, and the pulley width changes. Accordingly, it can be a pressing member that moves in the axial direction of the rotating shaft and presses the friction plate or the friction counterpart plate.

  In the continuously variable transmission according to the present invention, the pulley may be provided with a recess extending outward in the axial direction of the rotation shaft from the center of the pulley so as to accommodate at least a part of the rotation mechanism. The pressing member can be a member that protrudes and extends in the axial direction of the rotation shaft from the bottom of the recess.

  According to the present invention, since the clutch mechanism transmits the rotation of the rotating shaft to the rotating mechanism, the belt is driven from the rotating shaft side by the rotating mechanism, and the pulley and the belt are compared with the case where the belt is stationary. Thus, the contact can be made with a small speed difference. Since the rotating mechanism enables the transmission of power between the rotating shaft and the belt to be interrupted, the rotating pulley does not come into contact with the stationary belt, so that wear of the belt can be suppressed.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  First, a schematic configuration of an automobile to which a continuously variable transmission according to this embodiment is applied will be described with reference to FIG. FIG. 1 is a schematic diagram showing a schematic configuration of an automobile.

  As shown in FIG. 1, the automobile 1 is provided with an internal combustion engine 5 as a prime mover for driving the drive wheels 95. The internal combustion engine 5 includes a fuel injection device, an ignition device, and a throttle valve device (not shown), and these devices are controlled by a vehicle electronic control device (hereinafter referred to as an ECU) (not shown). Thus, the ECU can adjust the mechanical power generated by the internal combustion engine 5. The mechanical power generated by the internal combustion engine 5 is output from the crankshaft 6.

  Further, the motor 1 is transmitted from the damper 7 as a power transmission device that transmits the mechanical power output from the crankshaft 6 by the internal combustion engine 5 to the transmission, and a damper 7 that reduces torque fluctuation of the crankshaft 6. A forward / reverse switching mechanism 9 that enables the vehicle 1 to move forward and backward by switching the direction of rotation, and a belt-type continuously variable transmission 20 (hereinafter simply referred to as “speed change”) that changes the torque by changing the rotation from the forward / reverse switching mechanism 9. "CVT") is provided. A crankshaft 6 of the internal combustion engine 5 is coupled to a damper 7, and the damper 7 is coupled to a sun gear of a forward / reverse switching mechanism 9.

  The forward / reverse switching mechanism 9 is constituted by a planetary gear of a double pinion type (dual planetary type), and includes a forward clutch 9c that can engage the carrier and the sun gear, and a reverse brake 9b that can engage the ring gear with the housing. I have. By engaging the forward clutch 9c and releasing the reverse brake 9b, the mechanical power from the crankshaft 6 of the internal combustion engine 5 is transmitted to the input shaft 22 of the CVT 20 without changing the rotational direction. On the other hand, by releasing the forward clutch 9c and engaging the reverse brake 9b, the mechanical power from the crankshaft 6 changes the rotation direction to the opposite direction, and reduces the rotation speed to increase the torque. It is transmitted to the input shaft 22 of the CVT 20. Thus, the mechanical power output from the crankshaft 6 of the internal combustion engine 5 is transmitted to the input shaft 22 of the CVT 20 via the forward / reverse switching mechanism 9 after the torque fluctuation is reduced by the damper 7. The damper 7 may be directly coupled to the input shaft 22 of the CVT 20 without using the forward / reverse switching mechanism 9.

  The CVT 20 has an input side pulley 24 that engages with the input shaft 22 and rotates integrally with the input shaft 22, and an output side pulley 35 that engages with the output shaft 33 and rotates integrally with the output shaft 33. ing. Each of the input side pulley 24 and the output side pulley 35 is formed with a V-shaped groove, and a belt 60 having the same V shape is wound around the groove. The detailed structure of the CVT 20 according to this embodiment will be described later.

  The CVT 20 can change the winding diameter of the belt 60 wound around the pulley by changing the groove width (hereinafter referred to as pulley width) in the input pulley 24 and the output pulley 35. Yes. By changing the winding diameter of the belt 60 in the input pulley 24 and / or the output pulley 35, the CVT 20 changes the speed ratio that is the ratio between the rotational speed of the input shaft 22 and the rotational speed of the output shaft 33. Can do. In this way, the CVT 20 can receive the mechanical power from the internal combustion engine 5 by the input shaft 22 and continuously change the gear ratio inside and output it from the output shaft 33. .

  In addition, the automobile 1 is a power transmission device that transmits the mechanical power output from the output shaft 33 by the CVT 20 to the drive wheels 95, and a reduction mechanism 70 that reduces the rotation of the CVT 20 from the output shaft 33 and increases the torque. And a differential device 80 that distributes and outputs the mechanical power from the speed reduction mechanism 70 to the left and right drive shafts 90. The mechanical power from the CVT 20 is transmitted to the differential device 80 by reducing the rotational speed and increasing the torque by the speed reduction mechanism 70, and is distributed to the left and right drive shafts 90 by the differential device 80 to drive the drive wheels 95. To do.

  Next, the configuration of the belt type continuously variable transmission (CVT) according to the present embodiment will be described with reference to FIG. FIG. 2 is a longitudinal sectional view showing the entire configuration of the CVT. FIG. 2 schematically shows only the main part related to the present invention.

  The CVT 20 is spaced from the input shaft 22 by an input shaft 22 that is a rotating shaft that receives mechanical power from the internal combustion engine 5, an input-side pulley 24 that is provided coaxially with the input shaft 22 and rotates synchronously. And an output shaft 33 that is a rotation shaft that outputs mechanical power to the speed reduction mechanism 70, an output pulley 35 that is provided coaxially with the output shaft 33 and rotates synchronously, an input pulley 24, and an output pulley The belt 60 is wound around the belt 35 and transmits the mechanical power from the input shaft 22 to the output shaft 33.

  The input shaft 22 is coupled to the carrier of the forward / reverse switching mechanism 9 on the prime mover side, that is, the crankshaft 6 side of the internal combustion engine 5. The input shaft 22 receives mechanical power from the crankshaft 6 of the internal combustion engine 5. This is transmitted to the input side pulley 24. On the other hand, the output shaft 33 is engaged with the drive wheel 95 side, that is, the speed reduction mechanism 70. The output shaft 33 outputs the mechanical power received from the output side pulley 35 toward the drive wheel 95. The input side pulley 24 and the output side pulley 35 are engaged with these two rotating shafts, the input shaft 22 and the output shaft 33, respectively.

  The input pulley 24 is engaged with the fixed sheave 26 fixed in the axial direction C of the input shaft 22 and the input shaft 22, and is movable in the axial direction C of the input shaft 22 with respect to the fixed sheave 26. And a movable sheave. The input-side pulley 24 is provided so as to be coaxial with the input shaft 22, and rotates in synchronization with the input shaft 22.

  The fixed sheave 26 is formed with a fixed pulley surface 26a that faces the movable sheave 28 and supports the belt 60. On the other hand, the movable sheave 28 faces the fixed pulley surface 26a and has a movable pulley. A surface 28a is formed. The fixed pulley surface 26a and the movable pulley surface 28a are formed such that the interval in the axial direction C becomes narrower as the radial direction R of the input shaft 22 is directed inward. That is, a pulley groove that is a substantially V-shaped space is formed between the fixed pulley surface 26a and the movable pulley surface 28a. When the belt 60 is wound around the pulley groove of the input-side pulley 24, the fixed-side pulley surface 26a and the movable-side pulley surface 28a sandwich a side surface (flank surface) 66 of the belt 60, which will be described later. Friction engagement will occur.

  The movable sheave 28 and the input shaft 22 are engaged by a spline groove (not shown) formed so as to extend in the axial direction C. Thus, the movable sheave 28 rotates in synchronization with the input shaft 22 and can move in the axial direction C by sliding on the input shaft 22. The movable sheave 28 is driven by a hydraulic device (not shown) and is positioned in the axial direction C of the movable sheave 28, that is, in the axial direction C between the movable pulley surface 28 a of the movable sheave 28 and the fixed pulley surface 26 a of the fixed sheave 26. The interval (hereinafter referred to as pulley width) is controlled by the ECU. Thus, the input side pulley 24 is configured to be able to change the pulley width by moving the movable sheave 28. The input pulley 24 can change the diameter (hereinafter referred to as a winding diameter) formed by the belt 60 wound around the pulley by changing the pulley width.

  The belt 60 is configured such that a plurality of metal plate-like members (elements) having a substantially trapezoidal cross section are overlapped in a layer shape to form an annular shape. The side surfaces 66 (flank surfaces) on both sides of the belt 60, more specifically, the surface that contacts the fixed pulley surface 26a and the surface that contacts the movable pulley surface 28a, as the radial direction of the belt 60 goes inward, the belt The interval in the width direction of 60 is configured to be small. The side surface 66 of the belt 60 is sandwiched between the fixed and movable pulley surfaces 26a and 28a and receives a sandwiching pressure from these surfaces. As a result, the belt 60 frictionally engages with the input-side and output-side pulleys 24 and 35, and mechanical power from the input-side pulley 24 can be transmitted to the output-side pulley 35 described later.

  In the following description, the surface on the rotating shaft side (input shaft 22 side) of the belt 60 is referred to as a “back surface” 62. When the cross-sectional shape of the belt 60 has a trapezoidal shape as in the present embodiment, the upper base of the trapezoidal shape is the back surface 62 of the belt 60.

  Similarly to the input side pulley 24, the output side pulley 35 is engaged with the fixed sheave 26 fixed to the output shaft 33 and the output shaft 33, and is movable in the axial direction with respect to the fixed sheave 26. And a sheave 28. The fixed sheave 26 and the movable sheave 28 of the output-side pulley 35 are also formed with a fixed-side pulley surface 26a and a movable-side pulley surface 28a, respectively. When the belt 60 is wound around the output-side pulley 35, The pulley surface 26a and the movable pulley surface 28a are frictionally engaged with the belt 60 by sandwiching a side surface 66 of the belt 60 described later. The movable sheave 28 of the output pulley 35 is driven by a hydraulic device, and the pulley width is controlled by the ECU. The output-side pulley 35 is configured to be able to change the pulley width by moving the movable sheave 28, and the winding diameter of the belt 60 can be changed.

  Such a CVT 20 is controlled by the ECU to change the pulley width of the input side pulley 24 and the output side pulley 35 so that the winding diameter of the belt 60 can be changed in each pulley. . The ratio (Ro / Ri) between the winding diameter Ro of the belt 60 in the output pulley 35 and the winding diameter Ri of the belt 60 in the input pulley 24 is the rotational speed Ni of the input shaft 22 and the rotational speed No of the output shaft 33. This is the transmission ratio (Ni / No).

  When the gear ratio (Ni / No), which is the ratio between the rotational speed Ni of the input shaft 22 and the rotational speed No of the output shaft 33, is reduced (set to high gear), the CVT 20 sets the pulley width of the input pulley 24 to the output side. By making it smaller than the pulley width of the pulley 35, the winding diameter of the belt 60 in the input-side pulley 24 is made larger than the winding diameter in the output-side pulley 35. Thus, the CVT 20 can transmit the mechanical power received by the input shaft 22 to the output shaft 33 while increasing the rotational speed and decreasing the torque.

  On the other hand, when the transmission ratio (Ni / No) is increased (low gear), the pulley width on the input side is larger than the pulley width on the output side, so that the belt 60 around the input pulley 24 is wound. The diameter is made smaller than the winding diameter of the belt 60 in the output side pulley 35. As a result, the CVT 20 can transmit the mechanical power received by the input shaft 22 to the output shaft 33 by reducing the rotational speed and increasing the torque.

  In the automobile 1 provided with such a power transmission device, the rotational speed of the crankshaft 6 decreases as the vehicle decelerates, so that the internal combustion engine 5 does not stall at an unexpected timing when the vehicle is decelerated and stopped. Thus, it is necessary to reduce the rotational speed of the drive wheel 95 and increase the torque. The CVT 20 comes to a vehicle stop in a state where the gear ratio is increased as much as possible, that is, in a state where the pulley width of the input side pulley 24 is increased. In order to maintain the idling operation state of the internal combustion engine 5 and to enable the so-called idling stop operation that switches between the operation and non-operation of the internal combustion engine 5 while the vehicle is stopped, the crankshaft 6 of the internal combustion engine 5 is used. It is necessary to cut off power transmission between the motor and the drive wheel 95.

  The belt type continuously variable transmission (CVT) according to the present embodiment is provided with a mechanism for interrupting power transmission in the inside thereof, and will be described below with reference to FIG. FIG. 3A is an enlarged cross-sectional view of the input side pulley of the CVT. In FIG. 3A, the input-side pulley has a state in which the pulley width is larger than a predetermined width, and the belt detached from the pulley surface is supported by a rotating member described later.

  Between the fixed sheave 26 and the movable sheave 28 of the input side pulley 24 of the CVT 20, as a mechanism for interrupting power transmission, the belt 60 can be supported by rotating forward and backward about the input shaft 22. A rotation mechanism 40 is provided.

  The rotation mechanism 40 includes two ball bearings 44 provided coaxially with the input shaft 22, and a cylindrical member 46 provided on the outer side in the radial direction of the ball bearings 44. An inner side 44 a of the ball bearing 44 is in contact with the input shaft 22, and an inner surface 46 a of the cylindrical member 46 is coupled to the outer side 44 c of the ball bearing 44. Thereby, the cylindrical member 46 of the rotation mechanism 40 can be rotated forward and backward with respect to the input shaft 22.

  When the pulley 60 has a pulley width larger than a predetermined width and the belt 60 is detached from the fixed and movable pulley surfaces 26a and 28a, the outer surface 46c of the cylindrical member 46 receives the belt 60. At this time, the outer surface 46 c of the cylindrical member 46 is in contact with the back surface 62 of the belt 60. Thus, the rotation mechanism 40 can support the back surface 62 of the belt 60 from the input shaft 22 side by the outer surface 46c of the cylindrical member 46.

  The CVT 20 configured as described above increases the pulley width of the input pulley 24, thereby reducing the winding diameter of the input pulley 24 and increasing the pulley width beyond a predetermined width. Is brought into contact with the cylindrical member 46 of the rotation mechanism 40, and the fixed sheave 26 and the movable sheave 28 are separated from the side surface 66 of the belt 60. The belt 60 is separated from the input-side pulley 24 that rotates synchronously integrally with the input shaft 22, is wound around a rotation mechanism 40 that is rotatable with respect to the input shaft 22, and is supported from the back surface 62 by the rotation mechanism 40. To be stationary. In this way, the CVT 20 can disengage the input shaft 22 and the belt 60, and can interrupt power transmission between the input shaft 22 and the belt 60 inside the CVT 20.

  Thus, in the automobile 1 according to the present embodiment, even if the power transmission device does not have a clutch device or a torque converter, the drive wheel 95 and the output shaft of the CVT 20 that engages with the drive wheel 95 when the vehicle is stopped. 33, the input pulley 24, the input shaft 22 of the CVT 20, and the crankshaft 6 of the internal combustion engine 5 are rotating even though the output pulley 35 and the belt 60 are stationary (for example, idling state). ) And an idling stop operation for switching between operation and non-operation of the internal combustion engine 5 can be performed while the vehicle is stopped.

  As described above, when the power transmission is interrupted inside the CVT 20, the input pulley 24 and the belt 60 are engaged again to transmit power between the input shaft 22 and the output shaft 33. When the input side pulley 24 rotating together with the input shaft 22 is suddenly brought into contact with the side surface 66 (flank surface) of the belt 60 that is wound around the rotation mechanism 40 and is stationary, the side surface 66 of the belt 60 is recovered. The problem arises that the wears out. Since the side surface 66 of the belt 60 is a portion in contact with the input side pulley 24 and the output side pulley 35 during power transmission, it is necessary to suppress the wear of the side surface 66 of the belt 60 as much as possible.

  Therefore, in the belt type continuously variable transmission (CVT) according to the present embodiment, before the pulley contacts the belt, the clutch mechanism is engaged with the pulley and transmits the rotation of the rotation shaft (input shaft) to the rotation mechanism. This will be described with reference to FIGS. 3-1 and 3-2. FIG. 3-2 is an enlarged cross-sectional view of the input side pulley of the CVT, and shows a state where the movable sheave and the clutch mechanism are engaged.

  As shown in FIG. 3A, the clutch mechanism 50 is a wet multi-plate clutch having a substantially cylindrical shape, and the input shaft 22 and the shaft center are provided between the movable sheave 28 of the input pulley 24 and the rotating mechanism 40. Are concentrically arranged to match. On the side of the movable sheave 28 facing the fixed sheave 26, a substantially cylindrical recess 29 centered on the input shaft 22 is formed. The concave portion 29 is formed in the movable sheave 28 so as to extend from the center of the input side pulley 24 to the outside in the axial direction C of the input shaft 22. At least a part of the clutch mechanism 50 can be accommodated in the recess 29 of the movable sheave 28.

  The clutch mechanism 50 holds a friction plate 54 provided on the input shaft 22, a friction counter plate 58 that is disposed so as to sandwich the friction plate 54 and can be engaged with the friction plate 54, and the friction counter plate 58. A holding member 56 that transmits mechanical power received by the friction mating plate 58 to the rotation mechanism 40, and a pressing member 55 as an engaging means for engaging the friction plate 54 and the friction mating plate 58 are provided.

  The friction plate 54 is a plate-like member provided substantially orthogonal to the input shaft 22, and is a disk-like member in which a hole centered on the input shaft 22 is formed. The friction plate 54 is fitted to the input shaft 22 by a spline groove or the like extending in the axial direction C. The friction plate 54 is slidable in the axial direction C of the input shaft 22 and is engaged in the circumferential direction (rotational direction) of the input shaft 22. That is, the friction plate 54 can rotate integrally and coaxially with the input shaft 22, and mechanical power from the input shaft 22 can be transmitted to a friction counterpart plate 58 described later.

  The holding member 56 is a substantially cylindrical member, and extends in the axial direction C of the input shaft 22 from the end surface of the cylindrical member 46 constituting the rotation mechanism 40 on the movable sheave 28 side. Are combined. Inside the holding member 56, a plurality of friction counterpart plates 58 are arranged in the axial direction C so as to sandwich the friction plate 54 from both sides thereof. The holding member 56 and the cylindrical member 46 of the rotation mechanism 40 may be integrally formed.

  The friction counter plate 58 is a plate-like member provided substantially orthogonal to the input shaft 22, and is a disk-like member in which a hole centered on the input shaft 22 is formed. The friction plate 54 faces the friction plate 54 and is arranged in the axial direction C with a slight gap between the friction plate 54 and the friction plate 54. The friction counter plate 58 and the holding member 56 are fitted by a spline groove or the like extending in the axial direction C. The friction mating plate 58 is slidable in the axial direction C and is engaged with the input shaft 22 in the circumferential direction (rotating direction). When the compression force acts in the axial direction C of the input shaft 22, the friction counterpart plate 58 configured as described above sandwiches the friction plate 54 and engages with the friction plate 54 as shown in FIG. 3-2. Become. In this way, the friction counterpart plate 58 can transmit the mechanical power from the friction plate 54 to the rotation mechanism 40 via the holding member 56.

  As shown in FIG. 3A, the pressing member 55 is provided so as to protrude from the bottom surface 29 a of the concave portion 29 of the movable sheave 28 in the axial direction C of the input shaft 22. Opposite. The distance in the axial direction C between the pressing member 55 and the friction mating plate 58 facing the pressing member 55 is set to be larger than the distance between the movable pulley surface 28a and the side surface 66 of the belt 60 facing the movable pulley surface 28a. . That is, when the pressing member 55 moves to the fixed sheave 26 side along the axial direction C of the input shaft 22 together with the movable sheave 28, the movable pulley surface 28a of the input pulley 24 is moved to the belt as shown in FIG. Before coming into contact with the side surface 66 of 60, it is possible to abut against and press against the friction mating plate 58. The friction counter plate 58 pressed by the pulley pressing member 55 sandwiches the friction plate 54. In this way, the pressing member 55 functions as an engagement means for engaging the friction plate 54 and the friction counterpart plate 58 when the pulley width of the input side pulley 24 becomes smaller than a predetermined width.

  The clutch mechanism 50 configured as described above moves the movable sheave 28 toward the fixed sheave 26 along the axial direction C, and when the pulley width of the input-side pulley 24 becomes smaller than a predetermined width, FIG. As shown, the pressing member 55 provided on the movable sheave 28 presses the friction mating plate 58 and engages the friction mating plate 58 and the friction plate 54. As a result, the clutch mechanism 50 transmits the rotation of the input shaft 22 from the friction plate 54 engaged therewith to the cylindrical member 46 of the rotation mechanism 40 via the friction counterpart plate 58 and the holding member 56. . The outer surface 46 c of the cylindrical member 46 and the back surface 62 of the belt 60 are in contact with each other, and the rotation transmitted from the input shaft 22 to the cylindrical member 46 of the rotation mechanism 40 is transmitted from the back surface 62 to the belt 60. In the present embodiment, the rotation mechanism 40 and the clutch mechanism 50 are provided with the input shaft 22 as the center. However, the rotation mechanism 40 and the clutch mechanism 50 are provided with the output shaft 33 as the center. It is good as a thing.

  Next, the control of the belt type continuously variable transmission (CVT) according to the present embodiment will be described with reference to FIGS. 1 to 5 together with the operations of the internal combustion engine and the automobile. FIG. 4 is a longitudinal sectional view showing the overall configuration of the CVT, and shows a state where the input-side pulley is engaged with the side surface of the belt. FIG. 5 is a timing chart showing the operation of the automobile and the continuously variable transmission from the idling stop state until starting. FIG. 4 schematically shows only the main part related to the present invention.

  As shown in FIG. 5, at a time point before time point T1, the vehicle 1 is in a vehicle stop state, and the ECU sets the idle stop flag to the ON state because the accelerator operation amount is zero, so that the internal combustion engine 5 is turned on. Controlled to non-operating state. As a result, the rotational speed of the crankshaft 6 of the internal combustion engine 5 (hereinafter referred to as engine rotational speed) is zero. At this time, the ECU controls the belt engagement flag to be in an OFF state so that the pulley width of the input side pulley 24 of the CVT 20 is maximized. Thereby, as shown in FIGS. 2 and 3-1, in the CVT 20, the input side pulley 24 and the belt 60 are in a disengaged state, and the belt 60 is wound around the rotation mechanism 40, It is supported from the back surface 62.

  At time T1, an accelerator pedal (not shown) is operated by the driver of the automobile 1, and the accelerator operation amount becomes greater than zero. The ECU detects that the accelerator operation amount is not zero, sets the idle stop flag to the OFF state, starts the internal combustion engine 5 to be in the operating state, and reduces the pulley width of the input side pulley 24 from the maximum value. Go. That is, the movable sheave 28 is moved along the axial direction C toward the fixed sheave 26 side.

  From this time T1 to T2, the engine speed of the internal combustion engine 5 increases, but the pressing member 55 provided on the movable sheave 28 and the friction counterpart plate 58 of the clutch mechanism 50 are not yet in contact with each other. The input side pulley 24 and the side surface 66 of the belt 60 are not in contact. Power transmission is completely cut off between the input shaft 22 of the CVT 20 and the belt 60. The input shaft 22 and the input-side pulley 24 are rotated by mechanical power from the internal combustion engine 5, but the belt 60 is supported by the rotating mechanism 40 from the back surface 62 and is stationary. Thereby, the output side pulley 35 and the output shaft 33 engaged with the belt 60 and the driving wheel 95 engaged therewith are stationary.

  As shown in FIG. 3B, the pressing member 55 of the movable sheave 28 and the friction counterpart plate 58 come into contact with each other, and the friction plate 54 and the friction counterpart plate 58 are engaged. At this time, the fixed pulley surface 26 a and the movable pulley surface 28 a of the input pulley 24 are not in contact with the side surface 66 of the belt 60. The mechanical power received by the input shaft 22 of the CVT 20 is transmitted from the friction plate 54 to the rotation mechanism 40 via the friction counterpart plate 58. At this time, a rotational speed difference (slip) is generated between the friction plate 54 and the friction counterpart plate 58, and a part of the mechanical power from the friction plate 54 is dissipated as heat. The mechanical power transmitted from the friction partner plate 58 to the rotation mechanism 40 via the holding member 56 is transmitted from the back surface 62 to the belt 60 and starts to drive the belt 60.

  At time T2, the ECU turns on the belt engagement flag. As shown in FIG. 4, the ECU sets the pulley width of the input-side pulley 24 and the fixed-side pulley surface 26a and the movable-side pulley surface 28a to the belt 60. Control to contact the back surface 62 of When the fixed side and movable side pulley surfaces 26 a and 28 a of the input side pulley 24 are in contact with the side surface 66 of the belt 60, the cylindrical member 46 of the rotating mechanism 40 that supports the belt 60 is received from the friction counterpart plate 58. The rotation speed is driven by mechanical power, and the rotation speed is substantially the same as the rotation speed of the fixed sheave 26 and the movable sheave 28 of the input side pulley 24. That is, the side surface 66 of the belt 60 supported by the rotation mechanism 40 and the fixed side and movable side pulley surfaces 26a and 28a of the input side pulley 24 come into contact with each other in a state where the speed difference is substantially zero. In this way, the input-side pulley 24 abuts on the side surface 66 of the belt 60, so that wear on the side surface 66 of the belt 60 is suppressed.

  Then, after time T2, the fixed sheave 26 and the movable sheave 28 of the input side pulley 24 sandwich the belt 60 from the side surface 66, so that the back surface 62 of the belt 60 is separated from the cylindrical member 46 of the rotating mechanism 40. The mechanical power received by the input shaft 22 of the CVT 20 from the internal combustion engine 5 is transmitted to the side surface 66 of the belt 60 from the fixed and movable pulley surfaces 26 a and 28 a and is engaged with the output pulley 35. Drive. As shown in FIG. 5, the ECU increases the engine rotational speed of the internal combustion engine 5 in accordance with the increase in the accelerator operation amount, and reduces the pulley width of the input pulley 24 to reduce the gear ratio, thereby reducing the output shaft. The rotational speed of 33, that is, the speed of the vehicle is increased.

  As described above, the continuously variable transmission 20 (CVT) according to this embodiment includes the input pulley 22 and the output pulley 35 that are engaged with the input shaft 22 and the output shaft 33, which are two rotating shafts, respectively. The belt 60 is wound around the two pulleys 24 and 35 and can transmit the mechanical power from the input shaft 22 to the output shaft 33, and can be rotated forward and backward about the input shaft 22. The rotation mechanism 40 capable of supporting the belt 60 from the input shaft 22 side. When the pulley width becomes larger than a predetermined width, the belt 60 is separated from the input side pulley 24 and supported by the rotation mechanism 40. The power transmission between the input shaft 22 and the output shaft 33 can be cut off. In addition, since the clutch mechanism 50 transmits the rotation of the input shaft 22 which is a rotation shaft to the rotation mechanism 40, the belt 60 is driven from the input shaft 22 side by the rotation mechanism 40, and the pulley 24 and the belt 60 are Compared with the case where the belt 60 is stationary, the belt 60 can be contacted with a small speed difference. Since the rotation mechanism 40 enables the transmission of power between the input shaft 22 and the belt 60 to be interrupted, the rotating pulley 24 does not come into contact with the stationary belt 60 in rotation. Wear can be suppressed.

  Further, the continuously variable transmission 20 according to the present embodiment engages with the input side pulley 24 and transmits the rotation of the input shaft 22 to the rotation mechanism 40 before the input side pulley 24 contacts the side surface 66 of the belt 60. Since the clutch mechanism 50 is provided, the belt 60 is driven by the rotation mechanism 40, and the pulley 24 and the side surface 66 of the belt 60 can be brought into contact with each other in a state where the speed difference is substantially zero. Thereby, the wear on the side surface 66 of the belt 60 can be suppressed.

  Further, the continuously variable transmission 20 according to the present embodiment is mounted on the automobile 1, and the two rotation shafts are directed toward the input shaft 22 that receives mechanical power from the internal combustion engine 5 and the drive wheels 95. Therefore, even if the automobile 1 is not equipped with a clutch device or a torque converter, the internal combustion engine 5 and the drive wheel 95 are not engaged when the vehicle is stopped. The idling stop operation for switching between operation and non-operation of the internal combustion engine 5 while the vehicle is stopped can be realized while suppressing wear on the side surface 66 of the belt 60.

  Further, in the continuously variable transmission 20 according to the present embodiment, the rotation mechanism 40 and the clutch mechanism 50 are provided around the input shaft 22, so the automobile 1 including the belt type continuously variable transmission 20. Is normally stopped in a state where the gear ratio is large, that is, in a state where the pulley width of the input pulley 24 engaged with the input shaft 22 is large. For this reason, when the vehicle is stopped by providing the rotation mechanism 40 on the input shaft 22, the power transmission can be cut off only by slightly increasing the pulley width of the input side pulley 24. When the side pulley 24 and the belt 60 are engaged, the side surface 66 of the belt 60 can be engaged while being suppressed.

  In the continuously variable transmission 20 according to this embodiment, the input pulley 24 is fixed to the input shaft 22 and is movable relative to the fixed sheave 26 in the axial direction C of the input shaft 22. The rotating mechanism 40 is provided between the fixed sheave 26 and the movable sheave 28, and the clutch mechanism 50 is provided between the movable sheave 28 and the rotating mechanism 40. Therefore, when the pulley width of the input side pulley 24, that is, the interval between the fixed sheave 26 and the movable sheave 28 becomes larger than a predetermined interval, the belt 60 that is detached from the fixed sheave 26 and the movable sheave 28 is rotated. 40 can be satisfactorily received, and the configuration of the clutch mechanism 50 that engages with the input-side pulley 24 and transmits the rotation of the input shaft 22 to the rotation mechanism 40 can be easily realized.

  In the continuously variable transmission 20 according to the present embodiment, the movable sheave 28 is provided with a cylindrical recess 29 having the input shaft 22 as an axis so as to accommodate at least a part of the clutch mechanism 50. Thus, the clutch mechanism 50 is accommodated in the recess 29 when the pulley width of the input pulley 24 is reduced. The continuously variable transmission 20 provided with the turning mechanism 40 and the turning clutch mechanism 50 around the input shaft 22 that is a rotating shaft can be realized with a compact configuration.

  In the continuously variable transmission 20 according to this embodiment, the clutch mechanism 50 is disposed so as to sandwich the friction plate 54 and the friction plate 54 that rotate integrally with the input shaft 22, and engages with the friction plate 54. Thus, the friction mating plate 58 capable of transmitting mechanical power from the input shaft 22 to the rotating mechanism 40, and the engaging means for engaging the friction plate 54 and the friction mating plate 58 when the pulley width is smaller than a predetermined width. When the engaging means engages the friction plate 54 and the friction counterpart plate 58, the rotation of the input shaft 22 is transmitted to the rotation mechanism 40 via the friction plate 54 and the friction counterpart plate 58. Therefore, the mechanical power of the input shaft 22 is transmitted from the friction counterpart plate 58 to the rotation mechanism 40 by causing a speed difference (slip) between the friction plate 54 and the friction counterpart plate 58. it can. Since the mechanical power of the input shaft 22 is not suddenly transmitted from the rotation mechanism 40 to the back surface 62 of the belt 60, wear of the back surface 62 of the belt 60 can be suppressed as much as possible.

  Further, in the continuously variable transmission 20 according to this embodiment, the friction plate 54 and the friction counterpart plate 58 are plate-like members extending substantially orthogonal to the input shaft 22, and the engaging means is connected to the pulley 24. Since it is a pressing member 55 that is provided and moves in the axial direction of the input shaft 22 as the pulley width changes and presses the friction plate 54 or the friction counterpart plate 58, the shaft of the input shaft 22 that changes the pulley width The friction plate 54 and the friction counterpart plate 58 can be engaged with each other by using the directional force. In order to drive the engagement means, there is no need to provide a dedicated device for generating hydraulic pressure or electromagnetic force.

  Further, in the continuously variable transmission 20 according to the present embodiment, the pulley 24 has a recess 29 extending outward from the center of the pulley 24 in the axial direction of the input shaft 22 so that at least a part of the rotation mechanism 40 can be accommodated. Since the pressing member 55 is a member that protrudes and extends in the axial direction C of the input shaft 22 from the bottom surface 29a of the recess 29, the recess 29 rotates when the pulley width is reduced. While the mechanism 40 is accommodated, the friction plate 54 and the friction mating plate 58 can be engaged with each other by the pressing member 55 extending substantially orthogonal to the input shaft 22.

  In the continuously variable transmission 20 according to the present embodiment, the engagement means for engaging the friction plate 54 and the friction counterpart plate 58 moves in the axial direction C of the input shaft 22 as the pulley width changes and causes friction. Although the pressing member 55 that presses the mating plate 58 is used, the engaging means is not limited to this mode. Separately, a hydraulic piston may be provided on the input pulley 24 and the piston may be driven in the axial direction C of the input shaft 22 to engage the friction plate 54 and the friction counterpart plate 58.

  As described above, the continuously variable transmission according to this embodiment is useful for a belt-type continuously variable transmission for an automobile including an internal combustion engine as a prime mover, and in particular, between an input shaft and a crankshaft of the internal combustion engine. This is useful for a belt-type continuously variable transmission that does not include a clutch device or a torque converter and whose output shaft is engaged with a drive wheel of an automobile.

It is a schematic diagram which shows schematic structure of the motor vehicle which concerns on a present Example. 1 is a longitudinal sectional view showing an overall configuration of a belt type continuously variable transmission (CVT) according to an embodiment. It is an expanded sectional view of the input side pulley of the belt type continuously variable transmission (CVT) which concerns on an Example, and is a figure which shows the state from which the belt which remove | deviated from the pulley surface is supported by the rotation member. It is an expanded sectional view of the input side pulley of a belt type continuously variable transmission (CVT) concerning this example, and is a figure showing the state where a movable sheave and a clutch mechanism are engaged. It is a longitudinal cross-sectional view which shows the whole structure of the belt-type continuously variable transmission (CVT) which concerns on a present Example, and is a figure which shows the state which the input side pulley engaged with the side surface of the belt. It is a timing chart which shows operation of a car until a car concerning this example returns from an idle stop state and starts.

Explanation of symbols

1 automobile 5 internal combustion engine (motor)
6 Crankshaft 7 Damper 9 Forward / reverse switching mechanism 20 Belt type continuously variable transmission (CVT)
DESCRIPTION OF SYMBOLS 22 Input shaft 24 Input side pulley 26 Fixed sheave 26a Fixed side pulley surface 28 Movable sheave 28a Movable side pulley surface 29 Recess 33 Output shaft 35 Output side pulley 40 Turning mechanism 46 Cylindrical member 50 Clutch mechanism 54 Friction plate 55 Pressing member 56 Holding member 58 Friction mating plate 60 Belt 62 Back surface (belt)
66 Side (Belt)
70 Deceleration mechanism 80 Differential gear 90 Drive shaft 95 Drive wheel

Claims (9)

Two pulleys respectively engaged with two rotating shafts;
A belt wound around two pulleys and capable of transmitting mechanical power from one rotating shaft to the other rotating shaft;
A rotation mechanism configured to be able to rotate forward and backward about one rotation shaft, and capable of supporting the belt from the rotation shaft side;
A continuously variable transmission comprising a clutch mechanism capable of transmitting rotation of a rotating shaft to a rotating mechanism. The continuously variable transmission according to claim 1,
The clutch mechanism is a continuously variable transmission that engages with the pulley and transmits the rotation of the rotating shaft to the rotating mechanism before the pulley contacts the side surface of the belt. The continuously variable transmission according to claim 2,
A continuously variable transmission is mounted on a car,
2. The continuously variable transmission, wherein the two rotating shafts are an input shaft that receives mechanical power from the internal combustion engine and an output shaft that outputs mechanical power toward the drive wheels. The continuously variable transmission according to claim 3,
The continuously variable transmission, wherein the rotation mechanism and the clutch mechanism are provided around an input shaft. The continuously variable transmission according to any one of claims 1 to 4,
Each pulley has a fixed sheave fixed to the rotating shaft and a movable sheave movable in the axial direction of the rotating shaft with respect to the fixed sheave.
The rotation mechanism is provided between the fixed sheave and the movable sheave.
The continuously variable transmission, wherein the clutch mechanism is provided between the fixed sheave or the movable sheave and the rotation mechanism. The continuously variable transmission according to claim 5,
A continuously variable transmission, wherein the movable sheave or the fixed sheave is provided with a cylindrical recess having a rotating shaft as an axis so as to accommodate at least a part of the clutch mechanism. The continuously variable transmission according to any one of claims 1 to 6,
The clutch mechanism
A friction plate that rotates integrally with the rotating shaft;
A friction counterpart plate disposed so as to sandwich the friction plate and capable of transmitting mechanical power from the rotating shaft to the rotation mechanism by engaging with the friction plate;
When the pulley width is smaller than the predetermined width, the friction plate and the friction mating plate are engaged with engagement means,
A continuously variable transmission characterized in that when the engaging means engages the friction plate and the friction counterpart plate, the rotation of the rotating shaft is transmitted to the rotation mechanism via the friction plate and the friction counterpart plate. The continuously variable transmission according to claim 7,
The friction plate and the friction counterpart plate are plate-like members extending substantially orthogonal to the rotation axis,
The continuously variable transmission characterized in that the engaging means is a pressing member that is provided on the pulley and moves in the axial direction of the rotating shaft as the pulley width changes to press the friction plate or the friction counterpart plate. The continuously variable transmission according to claim 8,
The pulley is provided with a recess extending outward in the axial direction of the rotary shaft from the center of the pulley so as to accommodate at least a part of the rotation mechanism.
The continuously variable transmission, wherein the pressing member is a member that protrudes and extends in the axial direction of the rotation shaft from the bottom of the recess.

Images