JP4915361B2 - Belt for continuously variable transmission - Google Patents

Description

  The present invention relates to a belt for a continuously variable transmission in which a large number of plate-like elements are arranged in an annular shape so as to face each other, and these elements are bound in an annular shape by an endless annular ring.

  As a continuously variable transmission capable of continuously changing the gear ratio, that is, continuously changing, a belt type continuously variable transmission using a belt as a transmission member is known. This type of continuously variable transmission is configured to change the rotational speed ratio between the driving pulley and the driven pulley by changing the effective winding radius of the belt with respect to the driving pulley and the driven pulley. For example, as a continuously variable transmission mounted on a vehicle, a transmission configured to transmit torque as a pressing force of a belt due to a large torque to be transmitted is used.

  In other words, a so-called pressing type belt is a circular arrangement of plate-shaped metal pieces called elements (or blocks), which are bound together by a ring (sometimes called a hoop). It is configured to be sandwiched in a groove having a V-shaped cross section, and to transmit torque between the two by a frictional force between the element and the pulley. Each element is pressed by receiving torque from the driving pulley, pressing the preceding element to advance, and the driven pulley is configured to transmit the torque by rotating the driven pulley by the pressing force.

  In such a belt, each element keeps its intended posture, enters the winding groove of the pulley, and transmits the desired power by contacting the pulley, but the belt as a whole has flexibility. Since there is a need, some clearance is set between the elements and between the element and the ring, and there is room for the attitude of the element to change accordingly. As a result, when the element enters the winding groove of the pulley or receives a load in the winding groove, the posture of the element changes, and the change in the posture may vary from element to element. In such a case, torque transmission between the pulley and the element is not performed as expected, the torque capacity of the continuously variable transmission as a whole is reduced, or the power transmission efficiency is lowered. There is a possibility that the lifetime of

  Therefore, in the invention described in Patent Document 1, for example, protrusions that contact the inner surface of the pulley winding groove are formed on both sides of the V-shaped or tapered element, and the protrusions are rocking edges. It is provided at the same height as the height. The rocking edge is an edge that becomes a center for bringing adjacent elements into contact with each other and performing mutual rotation (so-called pitching) in the contact state. Therefore, in the invention of Patent Document 1, torque transmission between the pulley and the element occurs in the vicinity of the rocking edge, and as a result, the moment for rotating the element is reduced and the posture of the element can be stabilized. Has been.

JP 2001-355682 A

  In the configuration described in Patent Document 1 described above, torque transmission between the element and the pulley does not occur at a position far away from the locking edge that is the center of rotation (pitching) between the elements. Pitching and accompanying posture instability are prevented or suppressed. However, since the contact between the element and the pulley is limited to the central portion in the height direction of the element, rotation around the axis passing through the element in the thickness direction (that is, rolling) easily occurs, and the rotation The angle tends to increase. In the invention described in Patent Document 1, since the convex portion and the concave portion that connect the elements are formed in two places, the element is not affected even when a load causing rotation (rolling) is applied as described above. There is no rolling alone. On the other hand, from the viewpoint of workability and assemblability, in the element in which the above-mentioned convex part and concave part are formed in one place, since there is no means to counter such rotational force, the element is easy to roll and the element Even if the pitching can be prevented or suppressed, the tilting of the element occurs due to rolling, which may cause a decrease in torque capacity and power transmission efficiency, and may impair durability.

  The present invention has been made paying attention to the above-mentioned technical problems, and the postures of a large number of elements bound in a ring by a ring can be stabilized without rolling not only in pitching but also rolling inside a winding groove in a pulley. An object of the present invention is to provide a belt for a continuously variable transmission that can be made to operate.

  In order to achieve the above object, the invention of claim 1 is arranged such that a number of elements sandwiched in a winding groove having a V-shaped cross section formed on the outer peripheral portion of the pulley are arranged in an annular shape, and these elements are arranged by a ring. In a continuously variable transmission belt constituted by bundling, a pulley having a locking edge that is in contact with one surface of the element in a state of rotating relative to an adjacent element is wound around the pulley. Projecting portions that project toward the inner surface of the winding groove at the extended positions of the locking edge at the left and right side portions of the element and are sandwiched by the inner surface. The posture correction protrusions formed at the left and right side parts of the element are lower than the protrusions or The protrusions for fitting that are formed on at least one of the sides and restrict the vertical and horizontal positions of adjacent elements are formed on one surface of the element, and the protrusions for fitting of the adjacent elements are inserted. The fitting concave portion is formed on a surface opposite to the surface on which the fitting convex portion is formed.

  According to a second aspect of the present invention, in the first aspect of the present invention, a saddle surface on which the ring is mounted is formed at a central portion in the width direction of the element, and extends from the left and right side portions on the upper side of the saddle surface. A belt for a continuously variable transmission is characterized in that a hook portion for restricting escape of the ring from the saddle surface is formed by covering a side edge portion of the ring on the saddle surface.

  The invention according to claim 3 is the continuously variable transmission according to claim 1 or 2, wherein the protrusion is formed in a convex arc shape toward the inner surface of the winding groove. The belt.

  According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the tip of the posture correcting projection is formed on a flat surface facing the inner surface of the winding groove. This is a belt for a continuously variable transmission.

  Therefore, according to the first aspect of the present invention, each element that is annularly bound by the ring comes into contact with the inner surface of the winding groove in the pulley by the protruding portions formed at the extended positions of the locking edge on the left and right sides thereof. In addition, since the fitting convex part and the fitting concave part that connect the elements are formed in one place, the element resists the moment that causes rotation around the axis that penetrates the element in the thickness direction, that is, rolling. However, if a load causing rolling occurs in the element inside the winding groove, or if it is going to enter the winding groove in a rolled state, it will be above or below the protrusion. The posture correcting projections formed away from each other come into contact with the inner surface of the winding groove. Therefore, the element does not roll beyond the state in which the posture correction protrusion is in contact with the inner surface of the winding groove, and the posture correction protrusion protrudes toward the inner surface of the winding groove in the same manner as the protrusion. Therefore, the rolling angle of the element is regulated and becomes small, and as a result, the posture of the element can be stabilized to a predetermined posture without inclination or a posture close thereto. Further, even if the posture correction protrusion protrudes toward the inner surface of the winding groove, the protrusion amount is smaller than the protrusion amount of the protruding portion sandwiched in contact with the inner surface of the winding groove. There is no positive torque transmission through the projection. For this reason, the moment that causes the element to pivot in the front-rear direction, that is, pitching around the rocking edge, that is, the pitching is not increased. Therefore, according to the invention of claim 1, the posture of the element is prevented or prevented from rolling or pitching. It can be stabilized in a predetermined posture, and as a result, torque capacity, power transmission efficiency, and durability can be improved.

  According to the invention of claim 2, the hook portion is formed so as to extend upward in the saddle surface, but this is a state in which the hook portion extends in a direction perpendicular to the locking edge. Alternatively, even if the posture correction protrusions may be formed on the back surface (side facing the inner surface of the winding groove), a large load is not received from the inner surface of the winding groove, and as a result, from the saddle surface The durability of the hook portion extending upward can be improved. Further, in the case where the posture correction protrusion is formed on the side surface or the back surface of the hook portion, the posture correction protrusion is formed at a position far away from the protruding portion that transmits torque. With a small contact pressure with the inner surface of the winding groove, a large moment for correcting the posture of the element can be generated, and the posture correction effect can be improved.

  According to the invention of claim 3, since the tip end surface of the projecting portion transmitting torque between the element and the inner surface of the winding groove has an arc shape, even when rolling occurs in the element, The point at which torque transmission occurs between the element and the inner surface of the winding groove is prevented from being greatly separated from the extension line of the locking edge, and as a result, the so-called pitching suppression effect of the element can be improved.

  According to the fourth aspect of the present invention, when the posture correcting projection comes into contact with the inner surface of the winding groove so as to limit the rolling of the element, the contact area or length thereof can be increased. Further, it is possible to prevent or suppress wear on the inner surface of the winding groove.

  Next, the present invention will be described more specifically. The belt according to the present invention is used for a continuously variable transmission, and is sandwiched in a winding groove having a V-shaped cross section formed on an outer peripheral portion of the pulley, and as a result, friction generated between the belt and the pulley. It is configured to transmit torque with force. Therefore, the left and right side surfaces of the belt have a shape corresponding to the inner surface of the winding groove. Specifically, it is formed in a V shape or a taper shape. The width of the winding groove of the driving pulley and the width of the winding groove of the driven pulley change at the same time, so that the belt winding radius of each pulley changes to a large or small value. As a result, the rotation of the driving pulley and the driven pulley The number ratio, i.e. the transmission ratio, is configured to change. In this case, since the belt moves in the radial direction along the inner surface of the winding groove (moves along the generatrix of the inner surface which is a tapered surface), the belt's winding radius, that is, the gear ratio changes continuously, and there is no effect. A step shift state is established.

  The belt according to the present invention used in this way is formed by binding a large number of elements in a ring so as to form a ring as a whole and to form both sides V-shaped or tapered. . These elements are all metal plate pieces having the same shape, arranged in an annular shape with the same posture, and dimples to maintain the vertical and horizontal relative positions of the elements in the aligned state. And a recess called a hole in which the dimple loosely fits are formed at one place on both the front and back surfaces of the element. Specifically, the dimples are formed so as to protrude from the back surface or the front surface as a hole is formed by pressing one portion of the front surface or back surface of the element in the thickness direction to form a hole. Therefore, when the dimples are fitted into the holes of the adjacent elements, the relative movement of the elements in the radial direction, that is, the vertical direction and the horizontal direction is restricted. Rotation (rolling) about the penetrating axis is possible.

  Since the elements are arranged in a ring shape, there is always a place where the elements are arranged in a so-called fan-shaped (radial) shape centered on the center of curvature of the belt without being arranged in parallel. In order to allow a fan-shaped arrangement with the elements in contact with each other, the elements are formed with locking edges. Specifically, this rocking edge is a boundary line or boundary region where the thickness of the element changes, and in the width direction (direction parallel to the rotation center axis of the pulley) at the substantially central portion in the height direction of the element. It is formed to extend. That is, in the state where the belt is wound around the pulley, the circumference of the upper side of the element (outer side as a belt) becomes longer, so that the interval between the elements becomes wider, and on the contrary, the lower side of the element (as the belt) Is shorter on the inner circumference side), so that the distance between the elements is reduced. For this reason, the lower part of the element is configured so as to gradually become thinner on the lower end side, and the portion where the plate thickness changes between the upper side and the lower side of the element in this way is a rocking edge. Therefore, each element rotates in the plate thickness direction around the rocking edge, that is, pitching occurs and opens like a fan as described above. In addition, this rocking edge should just be formed in either one of front and back both surfaces, and is formed in the surface in which the said dimple is formed as an example.

  Each element has a saddle surface on which a ring is placed (arranged). The saddle surface is in contact with the ring that binds many elements, so the contact pressure increases when the belt is transmitting torque, whereas the elements are arranged in a straight line. When the belt is wound around the pulley and opened in a fan shape, sliding occurs between the ring and the saddle surface, and accordingly, a large frictional force is generated. The saddle surface is formed at a position as close as possible to the aforementioned rocking edge so that the moment due to this frictional force does not increase. Therefore, the saddle surface is formed at a substantially central portion in the vertical direction of each element.

  Further, the saddle surface is formed in accordance with the ring to be used. If the structure uses a single ring, the saddle surface is formed at one location of each element as a surface having a width slightly wider than the width of the ring. Further, if the configuration uses two rings, saddle surfaces are formed at two locations of each element in accordance with the rings. Further, if the two rings are arranged adjacent to each other, a saddle surface is formed at one place of each element as a surface slightly wider than the dimension obtained by adding the widths of the rings. .

  The ring is mounted on the saddle surface as described above, and binds the elements so that the elements maintain an annular arrangement, and acts to prevent the elements from separating outward in the radial direction. When the element is fed from the winding groove of the pulley, the element is also pulled out from the winding groove. For this reason, each element is provided with a structure for holding the ring in a state of being sandwiched between the saddle surface so that the ring does not escape from the element in the radial direction.

  An example of the configuration is a configuration in which a so-called top portion that protrudes in the left-right direction from the center portion in the width direction of the element is provided. That is, a neck portion extending upward from the saddle surface is formed at the center portion in the width direction of the element, and the bottom portion extends in the left-right direction so as to cover a part of the upper side of the saddle surface at the tip portion of the neck portion. A substantially triangular top is integrally formed. Accordingly, the ring is held between the saddle surface and the top thereof in a loosely sandwiched state.

  Another example is an example in which two rings are arranged in parallel on one saddle surface. In such a configuration, the elements extend upward from the saddle surface on the left and right sides of each element. A hook portion is provided to cover a part of the upper side of the saddle surface. The distance between the hook portions, in other words, the opening width of the saddle surface is wider than the width of one ring and smaller than the total of the widths of the two rings. Therefore, the ring is held between the saddle surface and its hook portion in a loosely sandwiched state.

  The left and right side surfaces of the belt in a state where the elements are arranged in an annular shape and bound by a ring form an inclined surface (taper surface) along the inner surface of the winding groove in the pulley. That is, the left and right side portions of each element are inclined in a tapered shape. Furthermore, the left and right side portions of each element are formed with protrusions for identifying the location where torque transmission occurs in the vicinity of the extended position of the locking edge without contacting the entire inner surface of the winding groove. ing. This is to reduce or avoid a moment that causes the element to rotate (pitch) in the front-rear direction around the rocking edge. Therefore, the protrusion is formed over both the upper and lower sides with the extended position of the locking edge as the center. The length and the height of the protrusion in the vertical direction can be determined experimentally in consideration of the crushing strength, the surface pressure generated between the inner surface of the winding groove and the workability. Further, the shape of the tip of the protruding portion is preferably a shape that does not increase the surface pressure between the inner surface of the winding groove, for example, formed in a plane parallel to the inner surface of the winding groove, or has a radius of curvature. It is formed in a large convex curved surface.

  As this protrusion is formed, the contact point between the element and the inner surface of the winding groove is limited to the center position in the vertical direction of the element. Rotation (rolling) about the axis passing through in the thickness direction is likely to occur. Postures for posture correction for restricting the rolling angle to a small angle and maintaining the posture of each element in the desired posture as much as possible are provided on the left and right sides of each element above or below the protrusion. It is formed at a position distant from at least one of them. This posture correction projection is for restricting the rolling of the element further by contacting the inner surface of the winding groove, and the amount of protrusion of the posture correction projection toward the inner surface of the winding groove Is less than the amount of protrusion of the protrusion. Here, the amount of protrusion is the amount of protrusion from the reference surface assumed as a surface parallel to the inner surface of the winding groove. Therefore, when the element is sandwiched in the normal position in the winding groove, the posture correction protrusion does not contact the inner surface of the winding groove, or even if it comes in contact, it makes a slight contact, and a substantial torque transmission. Is configured so that it does not touch. In the normal state, the portion between the protruding portion and the posture correcting projection among the left and right side portions of the element does not contact the inner surface of the winding groove.

  An example of the belt according to the present invention described above is schematically shown in FIG. The example shown here is a belt composed of two rings 1 and 2 that are arranged adjacent to each other and a large number of elements 4 that are bundled by placing these rings 1 and 2 on one saddle surface 3. 5, the element 4 is constituted by a metal piece having a substantially trapezoidal shape when viewed from the front or the back. Accordingly, the left and right side portions 6 and 7 form inclined surfaces (or tapered surfaces) parallel to the inner surface 10 of the winding groove 9 formed on the outer peripheral portion of the pulley 8 around which the belt 5 is wound.

  The pulley 8 includes a fixed sheave having a taper surface and a movable sheave having a taper surface that forms a winding groove 9 having a V-shaped cross section together with the taper surface, and changes the interval between these sheaves. Thus, the width of the winding groove 9 is changed to be wide and narrow, and the winding radius of the belt 5 is increased or decreased accordingly. The rings 1 and 2 are formed by laminating a plurality of thin metal strips.

  The thickness of the element 4 is substantially constant from the substantially central part to the upper part in the height direction (vertical direction), whereas the lower part is gradually thinner on the lower end side. Yes. Specifically, as shown in FIG. 2, the lower half of one surface (assumed to be the front) is inclined toward the other surface (assumed to be the back), and the thickness of this portion is on the lower end side. It is getting thinner. The boundary portion between the upper portion having a substantially constant thickness and the lower portion having a gradually decreasing thickness is a rocking edge 11. Therefore, the rocking edge 11 is a portion formed as a ridge line (or edge) along the width direction (that is, the direction parallel to the rotation center axis of the pulley 8) at the substantially central portion in the vertical direction of the element 4.

  A fitting convex portion, that is, a dimple 12 protruding to the front side is formed at a substantially central portion of the portion below the locking edge 11. A fitting recess, that is, a hole 13 for loosely fitting the dimple 12 of the adjacent element 4 is formed in the back side portion of the dimple 12. Accordingly, the dimple 12 of the other element 4 adjacent to the hole 13 of the one element 4 can be fitted into the hole 13 of the other element 4 so that these adjacent elements 4 can be relatively rotated (rolled). And the relative movement in the left-right direction is restricted, and the mutual arrangement state is maintained.

  Further, a saddle surface 3 is formed at a position close to the locking edge 11 in an upper portion of the locking edge 11. The saddle surface 3 is a portion on which two rings 1 and 2 arranged adjacent to each other are placed, or a portion through which the belts 1 and 2 are inserted. It is a substantially flat portion formed to have a width that is somewhat wider than the total size of the two widths.

  Hook portions (preventing portions) 15 and 16 are provided for preventing the rings 1 and 2 from being detached from the saddle surface 3, in other words, preventing the element 4 from being detached from the rings 1 and 2. The hook portions 15 and 16 are portions that partially cover the left and right sides of the saddle surface 3 from above. In the example shown in FIG. 1, the hooks 15 and 16 rise above the saddle surface 3 on the left and right ends of the element 4. It is an inverted L-shaped part. The narrowest portion between the hooks 15 and 16 is wider than the width of one ring 1 (or 2) and the width of two rings 1 and 2 arranged in parallel (the respective rings 1 and 2). It is narrower than the total width). Therefore, both end portions of the rings 1 and 2 arranged side by side on the saddle surface 3 are configured to be inserted between the saddle surface 3 and the hook portions 15 and 16.

  The left and right end portions 5 and 6 of the element 4 are substantially centered in the vertical direction, more precisely at a position where the locking edge 11 is extended, and contact the inner surface 10 of the winding groove 9 to be sandwiched from the pulley 8. Protrusions 17 and 18 that receive pressure are formed. The projecting portions 17 and 18 are portions protruding toward the inner surface 10 of the winding groove 9 over a predetermined range on both the upper and lower sides thereof with the extension position of the locking edge 11 as a center, It is formed in a plane parallel to the inner surface 10 of the winding groove 9. Therefore, when the element 4 enters the winding groove 9 in a normal posture, only the projecting portions 17 and 18 are configured to contact the inner surface 10 of the winding groove 9. In the state where only the protrusions 17 and 18 are in contact with the inner surface 10 of the winding groove 9 and torque is transmitted, the protrusions 17 and 18 are formed at the extended positions of the locking edge 11. As the torque is transmitted, the load that presses the element 4 in the thickness direction acts on the vicinity of the rocking edge 11, and as a result, a so-called pitching moment for rotating the element 4 around the rocking edge 11 is reduced or generated. Disappear.

  Posture correction protrusions 19 and 20 are formed above and below the protrusions 17 and 18, respectively. Specifically, the upper ends of the left and right sides 5 and 6 of the element 4 (the left and right sides 5 and 6 at positions corresponding to the upper ends of the hooks 15 and 16) and the lower end (the left and right sides of the thinnest part). At the portions 5 and 6), posture correcting projections 19 and 20 projecting toward the inner surface 10 of the winding groove 9 are formed. The posture correcting protrusions 19 and 20 are for restricting the rolling of the element 4 or reducing the rolling angle, and are formed as protrusions having a protrusion amount equal to or less than the protrusion amount of the protrusions 17 and 18 described above. Has been. Here, the protruding amount is a protruding amount from the reference surface assumed for the element 4 toward the inner surface 10 of the winding groove 9 as a surface parallel to the inner surface of the winding groove 9. Therefore, in a state where the element 4 is sandwiched in the winding groove 9 in a normal posture, the posture correction protrusions 19 and 20 do not contact the inner surface 10 of the winding groove 9 or transmit a substantial torque. It touches lightly enough not to do.

  The belt 5 according to the present invention has a large number of the elements 4 arranged in an annular shape with their postures aligned with each other, and in this state, the two rings 1 and 2 are fitted in parallel on the saddle surface 3, The element 4 is formed by binding the rings 1 and 2. When the belt 5 is wound around the winding groove 9 of the pair of pulleys 8 and sandwiched between the inner surfaces 10, the inner surface 10 of the winding groove 9 and the left and right side portions 5 and 6 of each element 4 are formed in a tapered shape. Therefore, the element 4 is subjected to a force that gradually pushes toward the outer periphery of the pulley 8. However, since each element 4 is bound by the rings 1 and 2, the element 4 is placed inside the winding groove 9 against the pushing force. It stays and is held inside the winding groove 9. The clamping pressure is indicated by a thick arrow in FIG.

  Each element 4 constituting the belt 5 according to the present invention includes projecting portions 17 and 18 formed at extended positions of the locking edge 11, and the projecting portions 17 and 18 contact the inner surface 10 of the winding groove 9. Torque transmission. Therefore, even if a moment that causes pitching acts on the element 4 with torque transmission, a load in the direction that causes pitching is generated in the vicinity of the rocking edge 11, so that the pitching moment is reduced. The posture in the pitching direction can be stabilized.

  Further, in the case where rotation, that is, rolling around the axis line penetrating the element 4 in the thickness direction or the dimple 12 and the hole 13 described above occurs, any one of the posture correcting protrusions 19 in addition to the protrusions 17 and 18 described above. , 20 contacts the inner surface 10 of the winding groove 9. An example of this state is shown in FIG. As described above, the amount of protrusion of the posture correcting projections 19 and 20 is smaller than the amount of protrusion of the protruding portions 17 and 18 that transmit torque, so that the posture correcting protrusions 19 and 20 and the inner surface 10 of the winding groove 9 However, if the posture correcting projections 19 and 20 are in strong contact with the inner surface 10 of the winding groove 9, no further rolling occurs.

  Further, since the posture correcting protrusions 19 and 20 protrude toward the inner surface 10 of the winding groove 9 from the portions adjacent to the protrusions 17 and 18, even if the element 4 is slightly rolled, Strong contact with the inner surface 10 to prevent further rolling. Thus, the rolling angle θ in a state where the rolling is restricted becomes the maximum allowable rolling angle. Since the maximum allowable rolling angle is limited to a small angle, the rolling of each element 4 can be suppressed and its posture can be stabilized. Therefore, in the belt according to the present invention, not only the pitching of each element 4 but also the rolling can be prevented or suppressed, and the posture of the element 4 with respect to the winding groove 9 can be stabilized to a normal posture or a posture close thereto. In addition, torque capacity and power transmission efficiency can be improved, and durability can be prevented or suppressed from generating and noise.

  The present invention can also be applied to a belt using a conventional element in which a neck portion and a top portion are formed at a central portion in the width direction. An example of this is shown in FIG. 4, and the base portion 33 in which the left and right side portions 31, 32 are inclined surfaces (or tapered surfaces) substantially parallel to the inner surface (not shown) of the winding groove in the pulley is made of metal. It is formed in a thin plate shape, and the left and right sides of the upper end portion of the base portion 33 are saddle surfaces 34 and 35. A locking edge 36 is formed slightly below the saddle surfaces 34, 35, and the portion below the locking edge 36 is configured to gradually become thinner toward the lower end.

  Further, a neck portion 37 extending upward is integrally formed at a central portion in the width direction of the base portion 33, and a so-called bottom side portion of the neck portion 37 extends above the saddle surfaces 34 and 35. A substantially triangular top 38 is integrated. Therefore, the portions from the center of the rings 39 and 40 placed on the saddle surfaces 34 and 35 are covered by the top portion 38, and the top portion 38 is caught by the rings 39 and 40, so that the element 30 is not detached from the rings 39 and 40. It is configured. A dimple 41 is formed on one surface of the central portion of the top portion 38, and a hole (not shown) is formed on the opposite surface.

  Further, projecting portions 42 and 43 for transmitting torque by being in contact with the inner surface of the winding groove and being sandwiched by pulleys are formed at the extended positions of the locking edge 36 in the left and right side portions 31 and 32 of the base portion 33. Has been. Also, posture correction protrusions 44 and 45 set to a protrusion amount equal to or less than the protrusion amount of the protrusion portions 42 and 43 are formed below the protrusion portions 42 and 43.

  The belt in which the elements 30 having the structure shown in FIG. 4 are arranged in an annular shape and bound by the rings 39 and 40 is wound around the winding grooves of a pair of pulleys, as in the example shown in FIG. Torque is transmitted by being pinched inside the winding groove. In this case, since torque is transmitted to and from the pulley at the protruding portion formed at the extended position of the locking edge 36, a moment that causes rotation (pitching) of the element 30 around the locking edge 36 is generated. However, since the point of action of the load is in the vicinity of the rocking edge 36, the pitching moment can be reduced and the posture of the element 30 can be stabilized. Further, even if rolling occurs in the element 30 because the contact portion between the element 30 and the pulley is limited to the projecting portions 42 and 43, if the element 30 rolls slightly, the posture correcting projections 44 and 45 are wound around the groove. The rolling angle of the element 30 is reduced because it is prevented from abutting against the inner surface of the element and rolling further. As a result, even when configured as shown in FIG. 4, not only the pitching of the element 30 but also the rolling is suppressed, the torque capacity and power transmission efficiency of the continuously variable transmission are improved, and the durability is reduced. Generation of noise can be prevented or suppressed.

  Note that, as described above, the protruding portion in the present invention is not limited to the configuration in which the shape of the tip is formed on a plane parallel to the inner surface of the winding groove. For example, as shown in FIG. The structure formed in the convex circular arc surface of this radius R may be sufficient. With such a configuration, the contact position with respect to the inner surface 10 of the winding groove 9 when the element 4 is slightly rolled is slightly shifted from the locking edge 11, so that the effect of suppressing the pitching of the element 4 can be increased. .

  Further, the number of rings in the present invention is not particularly limited, and a configuration using one ring may be used.

It is sectional drawing which shows the state cut | disconnected by the plane which passes along the rotation center axis line of a pulley in the state which wound an example of the belt which concerns on this invention on a pulley. It is a vertical side view which shows one of the elements. It is a schematic diagram which shows the state which rolled. It is a front view of the element which shows the example which applied this invention to the conventional element. It is sectional drawing similar to FIG. 1 which shows the example which formed the front end surface of the protrusion part in the convex circular arc surface.

Explanation of symbols

  1, 2, 39, 40 ... ring, 3, 34, 35 ... saddle surface, 4, 30 ... element, 5 ... belt, 6, 7, 31, 32 ... left and right sides, 8 ... pulley, 9 ... winding groove , 10 ... Inner surface, 11, 36 ... Rocking edge, 12 ... Dimple, 13 ... Hole, 15, 16 ... Hook part, 17, 18, 42, 43 ... Projection part, 19, 20, 44, 45 ... Protrusion for posture correction .

Claims (4)

In a continuously variable transmission belt constituted by arranging a large number of elements sandwiched in a winding groove having a V-shaped cross section formed in the outer peripheral portion of a pulley and bundling these elements by a ring,
On one surface of the element, a locking edge that contacts the adjacent element in a state of rotating relative to the adjacent element is formed in a direction parallel to the rotation center axis of the pulley in a state of being wound around the pulley. And
Protruding portions that protrude toward the inner surface of the winding groove at the extended position of the locking edge on both the left and right side portions of the element and are sandwiched by the inner surface are formed,
Protrusions for posture correction with a smaller amount of protrusion toward the inner surface than the protrusion are formed on at least one of the left and right sides of the element above or below the protrusion,
Further, a fitting convex portion that regulates the vertical and horizontal positions of adjacent elements is formed on one surface of the element, and the fitting concave portion into which the fitting convex portion of the adjacent element is inserted is the fitting convex portion. A belt for continuously variable transmission, characterized in that it is formed on a surface opposite to the surface on which is formed.   A saddle surface on which the ring is placed is formed at the center in the width direction of the element, and the ring extends by covering the side edge of the ring on the saddle surface by extending from the left and right side portions above the saddle surface. The continuously variable transmission belt according to claim 1, further comprising a hook portion that restricts the escape from the saddle surface.   The continuously variable transmission belt according to claim 1, wherein the protrusion is formed in a convex arc shape toward the inner surface of the winding groove.   The continuously variable transmission belt according to any one of claims 1 to 3, wherein a tip portion of the posture correcting protrusion is formed on a flat surface facing an inner surface of the winding groove.

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