JP2011094780A - Element of transmission belt for vehicle - Google Patents

Abstract

The present invention provides a plurality of elements constituting a transmission belt of a belt type continuously variable transmission for a vehicle and having high fatigue strength.
A relief portion provided at a portion where each of both inner side surfaces of a concave portion and a bottom surface intersects each other with a base end portion of each of the inner side surfaces on the side of the bottom surface in the width direction of the element. Indented outside. Accordingly, the escape portion 46 is provided on the locking edge portion 28 or close to the locking edge portion 28 as compared with the case where the relief portion 46 has the bottom surface 44 recessed toward the locking edge portion 28 side. Therefore, the stress concentration when the compressive force is applied to the locking edge portion 28 is alleviated. For example, the stress concentration near the portion where each of the inner side surfaces 40 of the recess 38 and the bottom surface 44 intersect is alleviated. The fatigue strength of the element 24 can be increased.
[Selection] Figure 4

Description

  The present invention relates to a structure of an element which is a component part of a transmission belt wound around a pair of pulleys having a variable groove width in a belt type continuously variable transmission for a vehicle.

  A pair of pulleys with variable groove widths and a plurality of elements sandwiched between the pair of pulleys in the thickness direction along an endless annular ring and wound around the pair of pulleys to transmit power. There is known a belt-type continuously variable transmission disposed in a power transmission path. In this transmission belt, power is transmitted between the pulleys while a plurality of elements are compressed in the thickness direction. Patent Document 1 discloses the above element that is a component part of a transmission belt of the belt type continuously variable transmission.

  The element of Patent Document 1 includes a recess that opens in the outer circumferential direction of the pulley and accommodates the ring, and is provided at the opening end of the recess and protrudes inward from the inner side surface on both sides in the width direction of the recess to cause the ring to A ring locking portion that locks in the recess, and a locking edge that functions as a swing center when swinging relative to an adjacent element and is provided on the inner peripheral side of the pulley from the bottom surface of the recess And a so-called concave element. And the said recessed part is equipped with the escape part which hollowed the part which each of the said inner side surface and the said bottom face crossed to the said rocking edge part side.

JP 2009-192025 A JP 2009-150425 A

  FIG. 5 is a front view and a left side view of an example of the concave element. 6 is an enlarged detailed view of the VI portion in FIG. As shown in FIGS. 5 and 6, in the concave element 200, the locking edge portion 204 that extends linearly is provided on the inner peripheral side of the pulley from the bottom surface 208 of the concave portion 206 that accommodates the ring 202. Actually, it is provided at a position very close to the bottom surface 208. Therefore, as shown in the broken line in FIG. 6, the relief portion 212 provided at the portion where each of the inner side surfaces 210 of the recess 206 intersects the bottom surface 208 is recessed toward the locking edge portion 204. In some cases, it is formed on the locking edge portion 204. Here, when power is transmitted, the concave element 200 receives a compressive force in the thickness direction at the locking edge portion 204 as shown in a broken line in FIG. 7 and releases the compressive force. Are repeated alternately, that is, due to the Poisson effect, for example, distortion occurs in the width direction of the concave element 200 and the distortion generated in the width direction is eliminated. Therefore, as shown in FIGS. 5 and 6, if the relief portion 212 is formed on the locking edge portion 204, stress concentration is repeated at the relief portion 212, so that the fatigue strength of the concave element 200 can be reduced. There was sex. Such a problem is not yet known.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to provide a plurality of elements constituting a transmission belt of a belt type continuously variable transmission for a vehicle and having high fatigue strength. It is to provide.

  In order to achieve the above object, the gist of the present invention is that (a) a plurality of transmission belts wound around a pair of pulleys of a belt-type continuously variable transmission are connected in the thickness direction along an endless annular ring. A recess that opens in the outer peripheral direction of the pulley and accommodates the ring, and functions as a swing center when swinging relative to an adjacent element, and is closer to the inner periphery of the pulley than the bottom surface of the recess. (B) In the concave portion, the base end portion on the bottom surface side of each of the inner side surfaces of the concave portion is recessed outward in the width direction of the element. The escape portion is provided.

  In this way, since the escape portion is not the one in which the bottom surface of the concave portion is recessed toward the locking edge portion side, the escape portion is compared with the case where the bottom surface is recessed in the locking edge portion side. Then, the stress concentration when the compressive force is received at the rocking edge portion is relieved, for example, the stress concentration near the portion where each of the inner side surfaces of the concave portion intersects the bottom surface is relieved, and the element The fatigue strength can be increased. In particular, the fatigue strength of the element can be increased when the locking edge portion is provided at a position very close to the bottom surface of the recess.

  Here, preferably, a curved surface that constitutes the escape portion and connects each of the inner side surfaces and the bottom surface is located at a predetermined length outside the inner side surface of the bottom surface in the width direction of the element. It is connected to the. In this way, the possibility that the ring rides on the curved surface and generates unnecessary bending stress can be eliminated with a sufficient margin.

1 is a perspective view showing a state in which a transmission belt is mounted on a vehicle belt type continuously variable transmission to which the present invention is preferably applied. It is sectional drawing of the transmission belt which shows the II arrow part cross section in FIG. 1, and its peripheral part. It is the front view of the element which looked at the element of FIG. 2 in the thickness direction, and its left view. FIG. 4 is an enlarged detailed view of a portion IV in FIG. 3. It is the figure which represented the example of the conventional concave element with the front view and the left view. FIG. 6 is an enlarged detailed view of a VI part in FIG. 5. FIG. 6 is a left side view of the concave element of FIG. 5, showing a state where a plurality of concave elements are in contact with each other.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a state in which a transmission belt 10 is mounted on a vehicle belt type continuously variable transmission 8 (hereinafter referred to as “belt type continuously variable transmission 8”) to which the present invention is preferably applied. . FIG. 2 is a cross-sectional view of the transmission belt 10 and its peripheral portion showing a cross section taken along arrow II in FIG. 1 and 2, the transmission belt 10 has a V-shaped groove 12 having a variable groove width on the outer peripheral portion and an output side pulley 14 provided so as to be rotatable around mutually parallel axes. A compression type transmission belt (metal belt) for the belt type continuously variable transmission 8 wound around the side pulley 16. The input pulley 14 and the output pulley 16 include fixed pulleys 14a and 16a fixed to the rotary shaft 18 and movable pulleys 14b and 16b provided so as to be relatively movable in the axial direction with respect to the rotary shaft 18. I have. The confronting surfaces of the fixed pulley 14a and the movable pulley 14b and the confronting surfaces of the fixed pulley 16a and the movable pulley 16b have a conical shape in which the relative distance in the axial direction increases toward the outer side in the radial direction. A pair of sheave surfaces 20 are provided respectively. The groove 12 is formed by the pair of sheave surfaces 20. The input pulley 14 and the output pulley 16 correspond to a pair of pulleys in the present invention. When the input pulley 14 and the output pulley 16 are not particularly distinguished, they are simply expressed as “pulley”.

The transmission belt 10 includes a pair of rings 22 formed by laminating a plurality of endless annular steel strips having flexibility, and is supported by the rings 22 and has a thickness direction DR _TH (see FIG. 3) along the rings 22. And a plurality of elements (tops) 24 made of plate-like metal connected in a ring shape.

  The ring 22 is made of, for example, a high-tensile steel plate having a thickness of about 0.2 mm that is formed into a ring shape and stacked in layers from the inside to the outside. In this embodiment, for example, there are approximately nine layers.

Figure 3 is a front view and a left side view of the element 24 viewed element 24 in its thickness direction DR _TH. FIG. 4 is an enlarged detailed view of a portion IV in FIG. The element 24 is a thick plate-like piece formed by punching a steel plate having a thickness of about 1.8 mm, for example, by press working. In the present embodiment, for example, about 400 elements 24 are provided for one transmission belt 10.

As shown in FIGS. 2 to 4, the element 24 is in contact with the pair of sheave surfaces 20 while facing the pair of sheave surfaces 20, and the elements 24 come into contact with each other in the curved state of the transmission belt 10. A rocking edge portion 28 that extends in a straight line functioning as a rocking center when rocking relatively with respect to the adjacent element 24, and a protrusion 32 that protrudes from one end face 30 in the thickness direction DR _TH of the element 24. And a concave projection housing portion 36 that receives the projection portion 32 provided on the other end surface 34 and projecting from the element 24 adjacent to the other end surface 34 side. Further, since the element 24 is locked to the ring 22, the element 24 opens in the outer circumferential direction of the pulleys 14, 16 and accommodates the ring 22, that is, the ring accommodating portion 38, and the concave portion provided at the opening end of the concave portion 38. from 38 widthwise DR _W sides of the inner surface 40 of the protruding inward and a ring engagement portion 42 for locking the ring 22 in the recess 38. As shown in FIG. 3, the rocking edge portion 28 is provided closer to the inner peripheral side of the pulleys 14 and 16 than the bottom surface 44 of the recess 38, and is provided, for example, close to the bottom surface 44. Note that when the transmission belt 10 performs power transmission, the elements 24 may be pressed against each other while swinging. In this case, the element 24 concentrates pressing force, that is, compressive force at the locking edge portion 28. Will receive. The inner surface 40 of the recess 38 contacts the end of the ring 22 and may be referred to as a ring end contact surface. The bottom surface 44 of the recess 38 contacts the inner periphery of the ring 22 so You may call a part contact surface.

As shown enclosed by broken lines in FIG. 4, the recess 38, the relief portion which is recessed a base end portion of the bottom surface 44 side of each of both inner side surfaces 40 of the recess 38 in the width direction DR _W outside of the element 24 46 is provided. The escape portion 46 is necessary to prevent unnecessary bending stress from being generated in the ring 22. The escape portion 46 has a curved surface 48 that connects each of the inner side surfaces 40 and the bottom surface 44. Then, the curved surface 48 is connected in the width direction DR _W predetermined length outwards L1 enters the position P1 of the element 24 than the inner surface 40 of the bottom 44. In other words, the bottom surface 44 is formed from the position P1. The predetermined length L1 is, for example, an extremely short length that is not zero, and is a length set experimentally so as to ensure that the ring 22 does not ride on the curved surface 48.

  According to the present embodiment, the relief portion 46 provided at the portion where each of the inner side surfaces 40 of the recess 38 intersects with the bottom surface 44 has the base end portion on the bottom surface 44 side of each of the inner side surfaces 40 as the element 24. It is what was dented in the width direction outside. In other words, the escape portion 46 is not a recess in which the bottom surface 44 of the recess 38 is recessed toward the locking edge portion 28. Accordingly, the escape portion 46 is provided on the locking edge portion 28 or close to the locking edge portion 28 as compared with the case where the relief portion 46 has the bottom surface 44 recessed toward the locking edge portion 28 side. Therefore, the stress concentration when the compressive force is applied to the locking edge portion 28 is alleviated. For example, the stress concentration near the portion where each of the inner side surfaces 40 of the recess 38 and the bottom surface 44 intersect is alleviated. The fatigue strength of the element 24 can be increased. In particular, when the locking edge portion 28 is provided at a position very close to the bottom surface 44 of the recess 38, the fatigue strength of the element 24 can be significantly increased.

In addition, according to the present embodiment, the curved surface 48 that constitutes the escape portion 46 and connects each of the inner side surfaces 40 and the bottom surface 44 has a width direction DR _{W of the} element 24 rather than the inner side surface 40 of the bottom surface 44. It is connected to a position P1 that enters a predetermined length L1 outward. Therefore, the possibility that the ring 22 rides on the curved surface 48 and generates unnecessary bending stress can be eliminated with a sufficient margin.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

  For example, in the above-described embodiment, the transmission belt 10 includes two rings 22 parallel to each other as shown in FIG. 2, but the number of the rings 22 is three or more even if one. There is no problem.

  In the above-described embodiment, it is described that the element 24 is formed by, for example, press working. However, the element 24 may be manufactured by other manufacturing methods such as die casting.

In the illustrated embodiment, the curved surface 48 constituting the escape portion 46 is connected in the width direction DR _W predetermined length outwards L1 enters the position P1 of the element 24 than the inner surface 40 of the bottom 44 However, a configuration in which the curved surface 48 is connected to a position intersecting the inner side surface 40 of the bottom surface 44 is also conceivable.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

8: Belt type continuously variable transmission 10: Transmission belt 14: Input side pulley (a pair of pulleys)
16: Output pulley (a pair of pulleys)
22: Ring 24: Element 28: Rocking edge portion 38: Recess 40: Inner side surface 44: Bottom surface 46: Escape portion 48: Curved surface

Claims (2)

In a transmission belt wound around a pair of pulleys of a belt type continuously variable transmission, a plurality of belts are connected in the thickness direction along an endless annular ring, and are adjacent to a recess that opens in the outer circumferential direction of the pulley and accommodates the ring. An element provided with a rocking edge portion that functions as a swing center when swinging relative to the element and is provided on the inner peripheral side of the pulley from the bottom surface of the recess,
An element of a power transmission belt for a vehicle, wherein the concave portion is provided with a relief portion in which a base end portion on the bottom surface side of each of both inner side surfaces of the concave portion is recessed outward in the width direction of the element. . The curved surface that constitutes the escape portion and connects each of the inner side surfaces and the bottom surface is connected to a position that has a predetermined length outside the inner side surface of the bottom surface in the width direction of the element. The element of the transmission belt for vehicles of Claim 1 characterized by the above-mentioned.

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