JP2016033381A - Continuously variable transmission actuator and continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce friction resulting from sliding of constituent components of an actuator and ensure smooth motion of the actuator and the long life of the actuator.SOLUTION: A continuously variable transmission actuator is configured so that an actuator 5 includes: a ball screw shaft 21a rotating about an axis by a motor 10; a ball screw nut 23a moving axially in response to the rotation of the ball screw shaft 21a and provided on the ball screw shaft 21a; a coupling member 24 attached to the ball screw shaft 23a; a guide member 27 guiding the coupling member 24 axially while prohibiting the coupling member 24 from rotating about an axis; and an arm 29 urging a movable sheave 4 to a fixed sheave 3, a notch groove 28 guiding the coupling member 24 is formed in the guide member 27, and this notch groove 28 includes a parallel portion 30 that slides relatively to the coupling member 24 and that is provided on a coupling side of the coupling member 24 to the arm 29 and a wide portion 31 that does not slide relatively to the coupling member 24 and that is provided on an axially opposite side to the coupling side.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a continuously variable transmission actuator and a continuously variable transmission used in a vehicle such as a small motorcycle.

  The continuously variable transmission has a driving pulley, a driven pulley, and a transmission belt wound between both pulleys, and changes the distance between a fixed sheave and a movable sheave that respectively constitute both pulleys. The gear ratio can be adjusted steplessly by continuously changing the winding diameter of the transmission belt wound around the pulley and the driven pulley.

  In order to bring this movable sheave into and out of contact with the fixed sheave, for example, as shown in Patent Document 1, a centrifugal roller type drive mechanism may be employed. In this drive mechanism, as shown in FIG. 3 and the like of this document, when the rotation of the output shaft increases, the centrifugal roller 3 moves outward by centrifugal force, and the clutch plate 8 is moved against the urging force of the spring 10. Press against the pulley 1a (movable sheave) side. By pressing the pulley 1a, the interval between the pulleys 1 (between the movable sheave and the fixed sheave) is narrowed, and the gear ratio is changed.

  Since this centrifugal roller type drive mechanism indirectly drives the pulley by the centrifugal roller moved by the action of centrifugal force, for example, if a malfunction such as being caught in the movement of the centrifugal roller occurs, high driving accuracy of the pulley can be obtained. I can't. In this case, there is a problem that it is not possible to obtain an optimum gear ratio corresponding to the engine speed and speed, and a high fuel efficiency improvement effect in the drive system cannot be obtained. Therefore, Patent Documents 2 and 3 adopt a configuration in which the movable sheave is directly driven by an actuator using a motor as a driving source instead of a centrifugal roller.

  The continuously variable transmission according to Patent Document 2 rotates the nut member 107 by rotating the rotating shaft 102a of the motor 102 about the axis as described in FIG. When the nut member 107 is rotated, the screw shaft 111 that meshes with the nut member 107 is displaced in the axial direction. As the screw shaft 111 is displaced, the pressing member 117 is also displaced in the same direction, and the fork member 300 is rotated in a predetermined direction. With this rotation, the movable sheave 207 is pressed and the movable sheave 207 approaches the fixed sheave 203.

  As described in FIG. 4 and the like of this document, the continuously variable transmission according to Patent Document 3 drives the output shaft 91 by the actuator unit 90 and moves the arm member 120 in the driving direction to move the movable pulley. 62 is moved. The arm member 120 is connected to the output shaft 91 of the actuator unit 90 via the connecting member 130.

  In the configuration according to Patent Document 2, the screw shaft 111 is used for driving in the axial direction, and this screw shaft 111 prevents relative rotation while allowing relative movement in the axial direction in the screw shaft chamber 101b. In order to do so, a detent must be provided (see paragraph 0046 of this document). Therefore, there is a problem that the configuration of the actuator becomes complicated. Further, since the mechanism is driven by the rotation of the screw shaft 111, there is a problem that a moment accompanying the rotation is applied to the surrounding members, and the life of the members is shortened.

  Moreover, in the structure which concerns on patent document 3, the actuator unit 90 and the arm member 120 have to be attached or detached every time of an assembly | attachment and component replacement | exchange, and there exists a problem that workability | operativity falls.

  The applicant of the present application has invented the continuously variable transmission shown in FIG. 1 of the drawings according to the present invention in view of such problems in the continuously variable transmission according to Patent Documents 2 and 3. The continuously variable transmission includes a main driving shaft 1 connected to the output shaft side of the engine, a main driving side pulley 2 provided on the main driving shaft 1, and a fixed sheave 3 and a movable sheave 4 that constitute the main driving side pulley 2. An actuator 5 that is separated, a driven shaft 6 that transmits power to the wheels, a driven pulley 7 provided on the driven shaft 6, and a transmission belt 8 that transmits the rotational force of the driven pulley 2 to the driven pulley 7. It is a major component.

  Opposed tapered surfaces are respectively formed on the fixed sheave 3 and the movable sheave 4 that constitute the main pulley 2. By moving the movable sheave 4 in the axial direction with respect to the fixed sheave 3, the distance between the sheaves 3 and 4 changes, and the rotation radius of the transmission belt 8 driven by the main driving pulley 2 is continuously changed. It is supposed to change.

  The actuator 5 decelerates the rotation output of the motor 10 with the parallel shaft speed reducer 13, and rotates the ball screw shaft 21a as the rotation member 21 around the axis by the reduced rotation output. The ball screw shaft 21 a is provided with a ball screw nut 23 a as a displacement member 23. As shown in FIGS. 2 and 3, a connecting member 24 is fixed to the ball screw nut 23a. The connecting member 24 is fitted into a notch groove 28 formed in the guide member 27 shown in FIG. When the ball screw shaft 21a is rotated around the axis by driving the motor 10, the ball screw nut 23a provided on the ball screw shaft 21a rotates relative to the ball screw shaft 21a around the axis.

  As described above, the ball screw nut 23a is fixed by the connecting member 24. Further, since the connecting member 24 is fitted in the guide member 27 fixed to the speed reducer case 12, the ball screw nut 23a is It moves forward and backward in the axial direction (the direction of the arrow shown in FIG. 1) without rotating around the axis with respect to the speed reducer case 12. Along with this advancement and retraction, the hatched portion of the connecting member 24 shown in FIG. 2 and the range indicated by the arrow (the portion and range indicated by the symbol A in this figure) and the range indicated by the arrow of the guide member 27 shown in FIG. (Ranges marked with B in the figure) slide on each other. The connecting member 24 is fixed to one end of the arm 29, and when the actuator 5 is driven, the movable sheave 4 connected to the arm 29 comes in contact with and separates from the fixed sheave 3, and the speed ratio of the pulley 2 is changed. .

JP 2004-257458 A JP 2009-79759 A Japanese Patent No. 5241642

  When the guide member 27 shown in FIG. 6 is used, the connecting member 24 and the guide member 27 slide over the entire length of the guide member 27 in the axial direction. is there. In addition, wear powder generated by the wear of the sliding portion may enter the gap between the ball screw shaft 21a and the ball screw nut 23a, and the actuator 5 may have a short life.

  Accordingly, an object of the present invention is to reduce the friction caused by the sliding of the constituent parts of the actuator to achieve smooth operation and long life of the actuator.

  In order to solve this problem, in the present invention, a pulley having a fixed sheave and a movable sheave paired with the fixed sheave, an actuator that makes the movable sheave contact and separate in the axial direction with respect to the fixed sheave, An actuator for a continuously variable transmission comprising: a rotating member that rotates by a driving force of a motor; an output member that is displaced in an axial direction by the rotation of the rotating member; and the output member that cannot rotate about an axis And an arm fixed to the output member, connected to the movable sheave and capable of rotating relative to the movable sheave, and capable of transmitting a load in both axial directions of the movable sheave. The guide member is formed with a notch groove for guiding the output member, and the notch groove is formed in the arc of the output member. And a parallel portion that slides with the output member, and a widened portion that does not slide with the output member on the opposite side of the connection side in the axial direction. Configured.

  Thus, by forming the notch groove of the guide member with the parallel portion and the widened portion, the output member is reliably guided in the axial direction by the parallel portion, and contact between the output member and the guide member is prevented at the widened portion. Thus, the friction caused by the sliding between the output member and the guide member can be minimized. Moreover, since the parallel portion is formed on the side connected to the arm of the output member (the side opposite to the side where the rotating member is provided), even if the output member and the parallel portion slide to generate friction powder, The friction powder hardly reaches the rotating member side of the output member. For this reason, the life of the actuator can be extended, and the actuator can be stably operated over a long period of time.

  In the above configuration, the output member includes a displacement member that receives the rotating member, and a coupling member that is fixed to the displacement member and guided by the guide member, and connected to the arm. It can be configured.

  In each of the above configurations, it is preferable that the rotating member is a ball screw shaft and the displacement member is a ball screw nut. This actuator is required to have high controllability to accurately stop at a predetermined position within the range of this linear motion in response to ON / OFF of the driving force of the motor while converting the rotational motion to linear motion. By using a ball screw shaft as the rotating member and using a ball screw nut as the displacing member, it is possible to achieve both conversion of rotational motion into linear motion and high controllability of the stop position.

  In each said structure, it is preferable to comprise the said wide part by the taper surface continuous with the said parallel part. By setting it as a taper surface, the mold release property at the time of casting-molding a guide member can be improved. The taper angle of the taper surface is preferably 3 degrees or more.

  In each of the above configurations, it is preferable that an enlarged portion that partially enlarges the groove width of the notch groove is formed on the inner surface of the parallel portion. By forming the enlarged portion in this manner, the wear powder is accumulated and held in the enlarged portion, and it is possible to further prevent the wear powder from reaching the rotating member. For this reason, the lifetime of the actuator can be further extended.

  By applying the actuator for continuously variable transmission according to each of the above configurations to a continuously variable transmission, the friction of internal parts of the actuator can be reduced as much as possible, and a high fuel efficiency improvement effect in the drive system can be obtained.

  In this invention, the actuator that makes the movable sheave constituting the pulley contact and separate in the axial direction with respect to the fixed sheave includes the rotating member that rotates about the axis by the driving force of the motor, and the amount of rotation of the rotating member that is displaced in the axial direction. A displacement member provided on the rotation member, a connecting member attached to the displacement member, a guide member that guides the connection member in an axial direction while making the connection member non-rotatable around an axis, and fixed to the connection member And an arm that biases the movable sheave toward the fixed sheave, and the guide member has a notch groove that guides the connecting member, the notch groove being formed by the connecting member. An actuator for a continuously variable transmission having a parallel portion that slides with the connecting member on a side connected to the arm and a widened portion that does not slide with the connecting member on the side opposite to the connecting side. You configure.

  According to this configuration, the connecting member is reliably guided in the axial direction at the parallel portion, and the contact between the connecting member and the guide member is prevented at the widened portion, and the sliding between the connecting member and the guide member is caused. Friction can be reduced as much as possible. In addition, since the parallel part is formed on the side connected to the arm of the connecting member (the side opposite to the side where the rotating member is provided), even if the connecting member and the parallel part slide to generate friction powder. This friction powder hardly reaches the ball screw. For this reason, the life of the actuator can be extended, and the actuator can be stably operated over a long period of time.

A longitudinal sectional view showing a continuously variable transmission according to the present invention 1A and 1B show connection members used in the actuator of the continuously variable transmission shown in FIG. 1, (a) is a front view, (b) is a left side view, (c) is a right side view, and (d) is a plan view. 2 is a longitudinal sectional view showing a state in which the connecting member shown in FIG. 2 is fixed to the ball screw nut. An example of the guide member used for the actuator of continuously variable transmission shown in FIG. 1 is shown, (a) is a bottom view, (b) is sectional drawing which follows the bb line in (a). The longitudinal cross-sectional view which shows the other example of the guide member used for the actuator of the continuously variable transmission shown in FIG. The conventional example of the guide member used for the actuator of the continuously variable transmission shown in FIG. 1 is shown, (a) is a bottom view, (b) is a longitudinal sectional view.

  A longitudinal sectional view of a continuously variable transmission according to the present invention is shown in FIG. The continuously variable transmission includes a main driving shaft 1 connected to the output shaft side of the engine, a main driving side pulley 2 provided on the main driving shaft 1, and a fixed sheave 3 and a movable sheave 4 that constitute the main driving side pulley 2. An actuator 5 that is separated, a driven shaft 6 that transmits power to the wheels, a driven pulley 7 provided on the driven shaft 6, and a transmission belt 8 that transmits the rotational force of the driven pulley 2 to the driven pulley 7. It is a major component.

  Opposed tapered surfaces are respectively formed on the fixed sheave 3 and the movable sheave 4 that constitute the main pulley 2. By moving the movable sheave 4 in the axial direction with respect to the fixed sheave 3, the distance between the sheaves 3 and 4 changes, and the rotation radius of the transmission belt 8 driven by the main driving pulley 2 is continuously changed. Can be changed.

  The configuration of the actuator 5 will be described. A motor 10 is provided in the motor case 9 of the continuously variable transmission, and an output gear 11 provided on the output shaft of the motor 10 meshes with a gear of a parallel shaft reducer 13 housed in a reducer case 12. Yes. The parallel shaft speed reducer 13 includes a first gear 14 that meshes with the output gear 11, a second gear 16 that is attached to the same rotation shaft 15 as the first gear 14, and a third gear 17 that meshes with the second gear 16. Consists of The first gear 14, the second gear 16, and the third gear 17 are all spur gears. The rotating shaft 15 to which the first gear 14 and the second gear 16 are attached is supported by a shell bearing 18 so as to be rotatable around the shaft.

  A holding shaft body 19 is fitted in the center of the third gear 17. The holding shaft body 19 is supported by two four-point contact ball bearings 20 and 20 so as to be rotatable around the axis. Instead of using the four-point contact ball bearing 20, a deep groove ball bearing can also be used. Further, the number of bearings is not limited to two and may be one. A ball screw shaft 21 a as a rotating member 21 is fitted into the end of the holding shaft 19 opposite to the end fitted into the third gear 17. A fixing member 22 is inserted into the ball screw shaft 21a in a direction perpendicular to the axial direction of the ball screw shaft 21a, and the holding shaft body 19 and the ball screw shaft 21a rotate together around the axis by the fixing member 22. ing.

  The ball screw shaft 21 a is provided with a ball screw nut 23 a as a displacement member 23. A male screw groove is formed on the outer peripheral surface of the ball screw shaft 21a, and a female screw groove is formed on the inner peripheral surface of the ball screw nut 23a at the same pitch as that of the male screw groove. Yes. Further, a circulation path (not shown) is formed in the ball screw nut 23a from one end side to the other end side of the ball screw nut 23a and facing both the grooves at both ends. As the ball circulates through the gap between the grooves and the circulation path, the ball screw nut 23a is displaced relative to the ball screw shaft 21a in the axial direction as the ball screw shaft 21a rotates. To do.

  Thus, by adopting the ball screw shaft 21a as the rotating member 21 and the ball screw nut 23a as the displacing member 23, it is possible to achieve both the conversion of the rotary motion to the linear motion and the high controllability of the stop position. However, instead of the ball screw shaft 21a and the ball screw nut 23a, a sliding screw may be used as the rotating member 21, and a sliding nut may be used as the displacement member 23, respectively.

  A connecting member 24 shown in FIG. 2 is fixed to the ball screw nut 23a. The connecting member 24 is an H-shaped plate member. As shown in FIG. 3, the ball screw nut 23a is integrally fixed by a screw 26 screwed into a screw hole 25 formed in the connecting member 24. The ball screw nut 23 a and the connecting member 24 constitute an output member 36 that outputs the driving force of the motor 10 to the pulley 2.

  The connecting member 24 is fitted into a notch groove 28 formed in the guide member 27 shown in FIG. This notch groove 28 does not slide with the connecting member 24 on the connecting side of the connecting member 24 with an arm 29 (to be described later) on the connecting portion 24 and on the side opposite to the connecting side in the axial direction. And a widened portion 31. The widened portion 31 has an angle of 3 degrees or more with respect to the parallel portion 30 and is a tapered surface continuous with the parallel portion 30. While the connecting member 24 is reliably guided in the axial direction by the parallel portion 30, contact between the connecting member 24 and the guide member 27 is prevented in the widened portion 31, and the sliding between the connecting member 24 and the guide member 27 is prevented. Friction caused by movement can be minimized.

  The guide member 27 is fixed to the speed reducer case 12. When the ball screw shaft 21a is rotated around the axis by driving the motor 10, the ball screw nut 23a provided on the ball screw shaft 21a rotates relative to the ball screw shaft 21a around the axis. The ball screw nut 23 a is fixed by a connecting member 24, and the connecting member 24 is fitted in a guide member 27 fixed to the speed reducer case 12, and the ball screw nut 23 a is attached to the speed reducer case 12. It moves forward and backward in the axial direction (the direction of the arrow shown in FIG. 1) without rotating around the axis.

  The connecting member 24 is fixed to one end side of the arm 29. Both are fixed by press-fitting a common press-fit pin 33 into the pin hole 32 formed in the connecting member 24 and the pin hole formed in the arm 29. Thus, by integrating the connecting member 24 and the arm 29 with the press-fit pin 33 in advance, the actuator 5 can be assembled and disassembled smoothly.

  Two double-row angular ball bearings 34, 34 are provided on the other end side of the arm 29 as release bearings for the main pulley 2, and the arm 29 is connected to the movable sheave 4 via the bearings 34, 34. Is urged toward the fixed sheave 3 side. By interposing the bearing 34 in this way, it is possible to apply an urging force to the movable sheave 4 that rotates about the axis by the arm 29 that does not rotate relative to the movable sheave 4. Instead of using the double row angular ball bearing 34, a deep groove ball bearing can also be used. Further, the number of bearings 34 is not limited to two, and may be one.

  A lubricating layer such as a solid lubricating treatment layer (deflick coat) may be formed on the parallel portion 30 of the guide member 27 shown in FIG. By forming the lubrication layer, friction due to sliding between the connecting member 24 and the guide member 27 can be reduced, and the movable sheave 4 can be smoothly brought into and out of contact with the fixed sheave 3. Instead of forming the lubricating layer in this way, a resin material can be used as a material at least in the vicinity of the parallel portion 30 of the guide member 27. Since this resin material has higher solid lubricity than other materials such as metal materials, the movable sheave 4 can be smoothly moved with respect to the fixed sheave 3 as in the case where the lubricating layer is formed on the sliding surface. You can touch and leave. As this resin material, for example, a fluororesin excellent in slidability and heat resistance can be employed.

  Another example of the guide member 27 is shown in FIG. This guide member 27 has a notch groove 28 formed in the same manner as the guide member 27 shown in FIG. 4, and this notch groove 28 is common in that it has a parallel portion 30 and a widened portion 31. The difference is that an enlarged portion 35 that partially enlarges the groove width of the notch groove 28 is formed on the inner surface of the parallel portion 30. The enlarged portion 35 can be formed in a groove shape as shown in FIG. By forming the enlarged portion 35, the wear powder generated by the friction between the connecting member 24 and the guide member 27 is accumulated and held in the enlarged portion 35, and the wear powder is retained in the ball screw shaft 21a. Can be prevented. For this reason, the lifetime of the actuator 5 can be further extended. The number (number) and shape of the enlarged portions 35 are not particularly limited.

  The above embodiment is merely an example, as long as the problem of the present invention of reducing the friction caused by sliding of the components of the actuator 5 to achieve smooth operation and long life of the actuator 5 can be solved. However, the shape, arrangement, material, and the like of each member can be changed as appropriate.

1 Drive shaft 2 Drive pulley (pulley)
3 fixed sheave 4 movable sheave 5 actuator 6 driven shaft 7 driven pulley 8 transmission belt 9 motor case 10 motor 11 output gear 12 reduction gear case 13 parallel shaft reduction gear (reduction gear)
14 First gear 15 Rotating shaft 16 Second gear 17 Third gear 18 Shell bearing 19 Holding shaft body 20 Four-point contact ball bearing (bearing)
21 Rotating member 21a Ball screw shaft 22 Fixed member 23 Displacement member 23a Ball screw nut 24 Connecting member 25 Screw hole 26 Screw 27 Guide member 28 Notch groove 29 Arm 30 Parallel portion 31 Widened portion 32 Pin hole 33 Press-fit pin 34 Double row angular contact Ball bearing
35 Enlarged part 36 Output member

Claims (6)

A pulley (2) having a fixed sheave (3) and a movable sheave (4) that is paired with the fixed sheave (3), and the movable sheave (4) are in axial contact with the fixed sheave (3). An actuator for a continuously variable transmission comprising an actuator (5) to be separated;
The actuator (5) is a rotating member (21) that is rotated by the driving force of the motor (10), an output member (36) that is axially displaced by the rotation of the rotating member (21), and the output member (36). ) Is fixed to the output member (36), and is rotatable relative to the movable sheave (4) and is movable relative to the movable sheave (4). And (29) an arm (29) connected so as to be able to transmit a load in both axial directions.
The guide member (27) is formed with a notch groove (28) for guiding the output member (36), and the notch groove (28) is formed on the arm (29) of the output member (36). ) And a parallel part (30) sliding with the output member (36), and a widened part (31) not sliding with the output member (36) on the opposite side of the connection side in the axial direction. An actuator for continuously variable transmission, comprising:   The output member (36) is a displacement member (23) that receives the rotation member (21), is fixed to the displacement member (23) and is guided by the guide member (27), and the arm ( 29. The continuously variable transmission actuator according to claim 1, further comprising: a connecting member (24) connected to 29).   The continuously variable transmission actuator according to claim 2, wherein the rotating member (21) is a ball screw shaft (21a) and the displacement member (23) is a ball screw nut (23a).   The actuator for continuously variable transmission according to any one of claims 1 to 3, wherein the widened portion (31) is configured by a tapered surface continuous with the parallel portion (30).   The continuously variable transmission according to any one of claims 1 to 4, wherein an enlarged portion (35) for partially expanding a groove width of the notched groove (28) is formed on an inner surface of the parallel portion (30). Actuator for machine.   A continuously variable transmission in which the movable sheave (4) is moved by the continuously variable transmission actuator according to any one of claims 1 to 5.

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