阅读说明：本技术 传动带及传动带用单体 (Transmission belt and single body for transmission belt ) 是由 三宅孝幸 越智亨 石原亘 德永淳一 于 2018-06-06 设计创作，主要内容包括：传动带的单体包括：一对凸曲面状的摇摆边缘部,以至少一部分横跨支柱部的方式在宽度方向上隔开间隔地形成于单体的正面以及背面中的一方；以及非接触部,以在一对摇摆边缘部之间与相邻的单体不接触的方式沿着鞍形面在宽度方向上延伸,当将一对摇摆边缘部的位于传动带的外周侧的端部的宽度的和设为“A”,将一对支柱部在包括摇摆边缘部的正面或者所述背面中的相比该摇摆边缘部更靠传动带的外周侧的部分的表面积的和设为“S”时,满足S/A≥3.5。(The monomer of the transmission belt includes: a pair of convexly curved swing edge portions formed on one of the front and rear surfaces of the single body at intervals in the width direction so that at least a part of the convexly curved swing edge portions straddles the pillar portion; and a non-contact portion extending in the width direction along the saddle surface so as not to contact the adjacent cells between the pair of rocking edge portions, wherein S/A is not less than 3.5 when a sum of widths of end portions of the pair of rocking edge portions on an outer peripheral side of the transmission belt is represented by "A" and a sum of surface areas of portions of the pair of column portions on an outer peripheral side of the transmission belt with respect to the rocking edge portions on a front surface or a rear surface including the rocking edge portions is represented by "S".)

1. A power transmission belt having a plurality of cells and rings, the cells comprising: a main body portion having a saddle-shaped surface; and a pair of strut parts extending from the body part so as to be positioned on both sides in the width direction of the saddle surface, wherein the ring is disposed between the pair of strut parts of the plurality of single bodies so as to be in contact with the saddle surface, and the transmission belt is wound around a primary pulley and a secondary pulley of a continuously variable transmission,

each of the monomers comprises: a pair of convexly curved swing edge portions formed on one of the front and back surfaces of the single body at an interval in the width direction so that at least a part of the convexly curved swing edge portions straddles the pillar portion; and a non-contact portion extending in the width direction along the saddle surface so as not to contact an adjacent cell between the pair of rocking edge portions,

when the sum of the widths of the ends of the pair of rocking edge portions on the outer peripheral side of the transmission belt is "A" and the sum of the surface areas of the portions of the pair of column parts on the outer peripheral side of the transmission belt with respect to the rocking edge portions on the front surface or the back surface including the rocking edge portions is "S", S/A ≧ 3.5 is satisfied.

2. The power transmission belt according to claim 1,

satisfies the condition that S/A is more than or equal to 3.5 and less than or equal to 5.0.

3. The power transmission belt according to claim 1 or 2,

satisfies the condition that S/A is more than or equal to 3.5 and less than or equal to 4.0.

4. A power transmission belt according to any one of claims 1 to 3,

an end portion of the swinging edge portion on the outer peripheral side of the transmission belt is located further outward in the radial direction of the transmission belt than the saddle surface, and an end portion of the swinging edge portion on the inner peripheral side of the transmission belt is located further inward in the radial direction of the transmission belt than the saddle surface.

5. A single body for a transmission belt includes a main body portion having a saddle surface that comes into contact with a ring of the transmission belt wound around a primary pulley and a secondary pulley of a continuously variable transmission, and a pair of stay portions extending from the main body portion so as to be positioned on both sides in a width direction of the saddle surface,

the monomer for the transmission belt comprises:

a pair of convexly curved swing edge portions formed on one of the front and back surfaces of the single body at an interval in the width direction so that at least a part of the convexly curved swing edge portions straddles the pillar portion; and

a non-contact portion extending in the width direction along the saddle surface so as not to contact an adjacent cell between the pair of rocking edge portions,

when the sum of the widths of the ends of the pair of rocking edge portions on the outer peripheral side of the transmission belt is "A" and the sum of the surface areas of the portions of the pair of column parts on the outer peripheral side of the transmission belt with respect to the rocking edge portions on the front surface or the back surface including the rocking edge portions is "S", S/A ≧ 3.5 is satisfied.

Technical Field

The present invention relates to a belt having a plurality of cells each including a pair of leg portions and a ring disposed between the pair of leg portions of the plurality of cells, and a cell for the belt.

Background

Conventionally, as a transmission belt for a continuously variable transmission, a transmission belt having: a plurality of single bodies each including a main body portion (base portion) and a pair of column portions extending from a left end or a right end of the main body portion; and a ring disposed between the pair of support portions of the plurality of cells (see, for example, patent document 1). In the single body of the belt, a pair of convexly curved rocking edge portions (contact areas) are formed on one surface at intervals in the width direction, and the adjacent single bodies pivot about a contact line included in the rocking edge portions.

Disclosure of Invention

In the single body as described above, the area of the portion of the pillar portion that protrudes further toward the outer circumferential side of the belt than the ring can be reduced as compared with a normal single body in which rings are arranged on both sides of the head portion extending from the central portion of the body portion in the width direction toward the outer circumferential side of the belt, and therefore, material costs can be reduced. However, in the transmission belt including the plurality of cells each having the pair of the stay portions, the pressing amount (deformation amount) of the stay portion may be partially larger than the pressing amount of the rocking edge portion (main body portion) in the chord portion (portion not wound around the pair of pulleys) of the transmission belt where the compression force acts on the plurality of cells from the pair of pulleys by reducing the area of the stay portion. Therefore, in the transmission belt including the plurality of cells having the pair of pillar portions, when a compressive force acts on the string portions of the plurality of cells, the plurality of cells may be misaligned when transmitting a torque, and vibration or noise may occur.

Therefore, a main object of the present invention is to suppress generation of vibration and noise when torque is transmitted between a pair of pulleys of a continuously variable transmission by a transmission belt including a plurality of single members having a pair of column portions.

The transmission belt of the present invention has a plurality of monomers and rings, the monomers including: a main body portion having a saddle-shaped surface; and a pair of strut parts extending from the body part so as to be positioned on both sides in a width direction of the saddle surface, wherein the ring is disposed between the pair of strut parts of the plurality of single bodies so as to be in contact with the saddle surface, and wherein the transmission belt is wound around a primary pulley and a secondary pulley of a continuously variable transmission, and wherein each of the single bodies includes: a pair of convexly curved swing edge portions formed on one of the front and back surfaces of the single body at an interval in the width direction so that at least a part of the convexly curved swing edge portions straddles the pillar portion; and a non-contact portion extending in the width direction along the saddle surface so as not to contact an adjacent cell between the pair of rocking edge portions, wherein when a sum of widths of end portions of the pair of rocking edge portions on an outer peripheral side of the transmission belt is defined as "a" and a sum of surface areas of portions of the pair of column portions on the outer peripheral side of the transmission belt with respect to the rocking edge portions out of the front surface and the back surface including the rocking edge portions is defined as "S", S/a is satisfied to be not less than 3.5.

The present inventors have conducted intensive studies to suppress generation of vibration and noise when torque is transmitted between a pair of pulleys of a continuously variable transmission by a transmission belt including a plurality of single members each having a pair of column portions. In the course of research, the inventors studied the relationship between the width of the rocking edge portion having a correlation with the pressing amount of the rocking edge portion, the surface area of the portion of the column portion having a correlation with the pressing amount of the column portion, which is located on the outer circumferential side of the belt than the rocking edge portion, the curvature of the loop of the chord portion of the belt in which the compressive force acts on the plurality of cells, and the curvature of the approximate curve passing through the rocking edge portion. The present inventors have also found that, when the sum of the widths of the ends of the pair of rocking edges on the outer peripheral side of the transmission belt is "a" and the sum of the surface areas of the portions of the pair of column parts on the outer peripheral side of the transmission belt than the rocking edges on the front surface or the back surface is "S", the single bodies are formed so as to satisfy S/a ≧ 3.5, and at the chord portions of the transmission belt where a compressive force acts on the single bodies, the center of curvature of the loop substantially coincides with the center of curvature of the approximate curve passing through the rocking edges. Thus, in the transmission belt of the present invention including a plurality of cells each satisfying S/a ≧ 3.5, the amount of pressure applied to the chord portion of the transmission belt by the compressive force can be made larger at the rocking edge portion than at the strut portion, and the occurrence of misalignment in the arrangement of the plurality of cells can be suppressed. As a result, it is possible to favorably suppress the occurrence of vibration and noise when torque is transmitted between a pair of pulleys of a continuously variable transmission by a transmission belt including a plurality of single members having a pair of column portions.

Drawings

Fig. 1 is a schematic configuration diagram showing an example of a continuously variable transmission including a belt according to the present invention.

FIG. 2 is a schematic configuration diagram showing the transmission belt of the present invention.

Fig. 3 is a schematic view illustrating an arrangement state of a plurality of cells at a chord portion of the transmission belt.

Fig. 4 is a schematic view illustrating an arrangement state of a plurality of cells at a chord portion of the transmission belt.

Fig. 5 is a graph showing a relationship between the sum of the widths of the end portions of the pair of swing edge portions on the outer circumferential side of the belt and the sum of the surface areas of the portions of the pair of pillar portions on the outer circumferential side of the belt than the swing edge portions, and the curvature of the loop and the curvature of the approximate curve passing through the swing edge portions.

Fig. 6 is a schematic configuration diagram of a modified transmission belt unit.

Detailed Description

Next, a mode for carrying out the present invention will be described with reference to the drawings.

Fig. 1 is a schematic configuration diagram showing a Continuously Variable Transmission (CVT)1 of the present invention. The continuously variable transmission 1 shown in the figure is mounted on a vehicle, and the continuously variable transmission 1 includes: a primary shaft (first shaft) 2 as a driving-side rotation shaft, a primary pulley (first pulley) 3 provided on the primary shaft 2, a secondary shaft (second shaft) 4 as a driven-side rotation shaft disposed in parallel with the primary shaft 2, a secondary pulley (second pulley) 5 provided on the secondary shaft 4, and a transmission belt 10. As shown in the drawing, the transmission belt 10 is wound around a pulley groove (V-shaped groove) of the primary pulley 3 and a pulley groove (V-shaped groove) of the secondary pulley 5.

The primary shaft 2 is coupled to an input shaft (not shown) connected to a power generation source, which is referred to as an engine (internal combustion engine) of a vehicle, via a forward/reverse switching mechanism (not shown). The primary pulley 3 includes: a fixed sheave 3a formed integrally with the primary shaft 2; the movable sheave 3b is supported by the primary shaft 2 via a ball spline or the like so as to be slidable in the axial direction. In addition, the secondary pulley 5 includes: a fixed sheave 5a formed integrally with the secondary shaft 4; the movable sheave 5b is supported by the secondary shaft 4 via a ball spline or the like so as to be slidable in the axial direction, and is biased in the axial direction by a return spring 8.

Moreover, the continuously variable transmission 1 includes: a primary cylinder 6 as a hydraulic actuator for changing a groove width of the primary pulley 3; the secondary cylinder 7 as a hydraulic actuator changes the groove width of the secondary pulley 5. The primary cylinder 6 is formed behind the movable sheave 3b of the primary pulley 3, and the secondary cylinder 7 is formed behind the movable sheave 5b of the secondary pulley 5. In order to change the groove widths of the primary pulley 3 and the secondary pulley 5, working oil is supplied to the primary cylinder 6 and the secondary cylinder 7 from an unillustrated oil pressure control device. The secondary shaft 4 is coupled to drive wheels (all not shown) of the vehicle via a gear mechanism, a differential gear, and a drive shaft.

In the present embodiment, a stepped portion is formed at an end portion (left end portion in fig. 1) of the primary shaft 2 on the side opposite to the engine side. An annular end plate 65 is interposed between the stepped portion and the primary piston 60 of the primary cylinder 6 so as to be able to contact an end portion (left end portion in fig. 1) of the movable sheave 3b of the primary pulley 3 on the side opposite to the engine side. Further, a stopper portion 2s is formed in the primary shaft 2 so as to be able to abut against an end portion of the spline teeth 3s formed on the inner peripheral surface of the movable sheave 3b on the fixed sheave 3a side.

When the movable sheave 3b of the primary pulley 3 is brought into contact with the end plate 65 away from the fixed sheave 3a, the movement of the movable sheave 3b relative to the primary shaft 2 in the direction away from the fixed sheave 3a is restricted. Accordingly, the width of the pulley groove of the primary pulley 3 becomes maximum, and along with this, the width of the pulley groove of the secondary pulley 5 is set to be minimum, whereby the transmission ratio γ of the continuously variable transmission 1 becomes maximum. When the spline teeth 3s formed on the inner peripheral surface of the movable sheave 3b abut against the stopper 2s formed on the primary shaft 2, the movable sheave 3b is restricted from moving toward the fixed sheave 3a relative to the primary shaft 2. As a result, the width of the pulley groove of the primary pulley 3 becomes minimum, and the transmission belt 10 sets the width of the pulley groove of the secondary pulley 5 to maximum, thereby minimizing the transmission ratio γ of the continuously variable transmission 1.

Fig. 2 is a schematic configuration diagram showing the belt 10. As shown in the drawing, the belt 10 includes: a single laminated ring 12 configured by laminating a plurality of (for example, 9 in the present embodiment) elastically deformable ring members 11 in a thickness direction (ring radial direction); a retainer ring 15; and a plurality of (for example, several hundreds of) cells 20 arranged (bundled) annularly along the inner peripheral surface of the stack ring 12. In the present embodiment, the monomer 20 includes a first monomer and a second monomer having a thickness (maximum thickness) slightly larger than the first monomer (for example, about 0.1 mm), and a plurality of the first monomers and the second monomers are arranged adjacent to each other. This can suppress the generation of vibration and noise when torque is transmitted between the drive belt 10 and the primary pulley 3 and the secondary pulley 5. Since the first monomer and the second monomer have a common structure except for the thickness, both are hereinafter collectively referred to as "monomer 20".

The plurality of ring members 11 constituting the laminated ring 12 are each an elastically deformable member cut out from a steel plate Drum (Drum), and are processed to have substantially the same thickness and different circumferential lengths. The retainer ring 15 is an elastically deformable member cut out from a drum made of, for example, steel plate, and has a thickness substantially the same as or thinner than that of the ring member 11. In addition, the slinger 15 has a longer inner circumference than the outer circumference of the outermost ring member 11o of the laminated ring 12. Thus, in a state where the stack ring 12 and the retainer ring 15 are concentrically arranged (a no-load state where tension is not applied), as shown in fig. 2, an annular gap is formed between the outer peripheral surface of the outermost ring member 11o and the inner peripheral surface of the retainer ring 15.

Each single body 20 is a member having a bilaterally symmetrical outer shape punched out of a steel plate by press working, for example, and as shown in fig. 2, each single body 20 has: a main body 21 extending horizontally in the figure; a pair of column parts 22 extending in the same direction from both ends of the body part 21; a single ring housing portion (recess) 23 formed by dividing between the pair of column portions 22 so as to open to the free end side of each column portion 22; and a pair of side surfaces 20s formed so as to be spaced apart from each other from the inner circumferential side toward the outer circumferential side (the outer side in the radial direction of the laminated ring 12) of the transmission belt 10 (the laminated ring 12).

The pair of column portions 22 extend from both sides in the width direction of the saddle surface 23s that is the bottom surface of the ring housing portion 23 to the outside in the radial direction of the laminated ring 12 (the direction from the inner circumferential side to the outer circumferential side of the transmission belt 10 (laminated ring 12), that is, upward in the drawing), and a hook portion 22f that protrudes in the width direction of the saddle surface 23s is formed at the free end portion of each column portion 22. The pair of hook portions 22f are slightly longer than the width of the laminated ring 12 (ring member 11), and face each other with a space shorter than the width of the stopper ring 15. Each of the strut parts 22 of the unit 20 has a flat inner surface 22i inclined so as to be spaced apart from the saddle surface 23s as it goes radially outward of the laminated ring 12, and a concave curved surface (for example, a concave cylindrical surface) smoothly continuing between the saddle surface 23s and the inner surface 22i of each strut part 22 is formed therebetween.

As shown in fig. 2, the stacked ring 12 is disposed in the ring housing 23, and the saddle surface 23s of the ring housing 23 contacts the inner peripheral surface of the innermost ring member 11i, which is the stacked ring 12. The saddle-shaped surface 23s has a bilaterally symmetric convex curved surface shape (convex shape) that is gently inclined downward in the figure toward the widthwise outer side with the widthwise central portion as the top portion T. Thus, a centripetal force toward the top portion T is applied to the laminated ring 12 by friction with the saddle surface 23s, and the laminated ring 12 can be centered. However, the saddle surface 23s may include a plurality of convex curved surfaces curved outward in the radial direction of the laminated ring 12.

Then, the elastically deformed retainer ring 15 is fitted into the ring housing 23 from between the pair of hook portions 22f of each unit 20. The stopper ring 15 is disposed between the outer peripheral surface of the outermost ring member 11o of the laminated ring 12 and the hook portion 22f of each cell 20, surrounds the laminated ring 12, and regulates, together with the pair of column portions 22, the separation of each cell 20 from the laminated ring 12 or the separation of the laminated ring 12 from the cell 20. Thereby, the plurality of cells 20 are bundled (arranged) in a ring shape along the inner peripheral surface of the stack ring 12. In the present embodiment, the retainer ring 15 is formed with a single or multiple openings (long holes), not shown, so that the retainer ring 15 can be easily elastically deformed, and the assemblability to the single body 20 can be ensured.

As described above, a gap is formed between the outer peripheral surface of the outermost ring member 11o of the laminated ring 12 and the inner peripheral surface of the stopper ring 15, and tension or the like does not substantially act on the stopper ring 15 during operation of the continuously variable transmission 1. Therefore, in the single body 20, it is not necessary to increase the column portion 22 and the hook portion 22f in order to secure rigidity or the like, and the area of the portion of the column portion 22 protruding further toward the belt outer circumferential side than the laminated ring 12 can be reduced as compared with a normal single body in which laminated rings are arranged on both sides of the head portion extending from the center portion in the width direction of the main body portion toward the belt outer circumferential side. Therefore, the cost of the belt 10 and the continuously variable transmission 1 can be reduced by reducing the material cost of the single body 20.

Each side surface 20s of the single body 20 includes: a first side surface 20sa located on the pillar portion 22 side, i.e., on the opposite side (outer side) of the inner surface 22i of the pillar portion 22; the second side surface 20sb is formed continuously with the first side surface 20sa and is located further inward in the radial direction of the stack ring 12 than the first side surface 20 sa. In the present embodiment, the pair of first side surfaces 20sa and the pair of second side surfaces 20sb are formed so as to be separated from each other as they go outward in the radial direction of the laminated ring 12. This can ensure the strength of each column part 22 satisfactorily.

The angle formed by the pair of second side surfaces 20sb is set to be substantially equal to (slightly larger than the design value of the opening angle in the present embodiment) the opening angle of the pulley grooves of the primary pulley 3 and the secondary pulley 5, and the angle formed by the pair of first side surfaces 20sa is set to be smaller than the angle formed by the pair of second side surfaces 20 sb. Thus, the second side surface 20sb of the single body 20 comes into frictional contact with the pulley groove of the primary pulley 3 and the pulley groove of the secondary pulley 5, receives the clamping pressure from the pulleys 3 and 5, and serves as a torque transmission surface (side surface) for transmitting torque from the primary pulley 3 to the secondary pulley 5 by frictional force. In contrast, the pair of first side surfaces 20sa does not substantially contact the pulley groove surfaces when torque is transmitted from the primary pulley 3 to the secondary pulley 5 via the transmission belt 10. Further, on the surface of each second side surface 20sb, there are formed irregularities (a plurality of grooves), not shown, for retaining working oil for lubricating and cooling the contact portion between the single body 20 and the primary pulley 3 and the secondary pulley 5.

As shown in fig. 2, a pair of rocking edge portions (contact regions) 25, non-contact portions 27, tapered surfaces (inclined surfaces) 21s, and a single protrusion (recess) 21p are formed on the front surface (one surface) of the single body 20. The pair of rocking edges 25 are formed on the front surface of the single body 20 at intervals in the width direction of the saddle surface 23s so as to straddle the corresponding strut member 22 and the body portion 21. In addition, the non-contact portion 27 is formed in the middle of the pair of rocking edge portions 25 in the above-described width direction. In the present embodiment, the edge portion on the inner periphery side of the belt (lower edge portion in fig. 2) of the noncontact section 27 is located closer to the inner periphery side of the belt (lower side in the figure) than the edge portion on the inner periphery side of the belt (lower edge portion in fig. 2) of the swing edge section 25. The tapered surface 21s is formed on the front surface (one surface) of the main body 21 so as to extend from the non-contact portion 27 and the pair of rocking edge portions 25 toward the inner peripheral side (lower side in fig. 2) of the belt, which is the opposite side to the projecting direction of each pillar portion 22. The projection 21p projects from the tapered surface 21s at the center in the width direction of the front surface of the body 21.

In the present embodiment, as shown in fig. 3, the front surface of the cell 20 (mainly, the front surface of the column portion 22) and the back surface (the other surface) of the cell 20 on the outer circumferential side of the belt with respect to the rocking edge portion 25 and the non-contact portion 27 are formed flat, and the column portion 22 of the cell 20 has a constant thickness te. However, the single body 20 is formed by press working, so-called sagging occurs at the peripheral edge portion of the pillar portion 22, and a portion formed flat on the front and back surfaces of the pillar portion 22 is a region surrounded by the peripheral edge portion and the swing edge portion 25 (see a hatched portion in fig. 2).

As shown in fig. 3, the tapered surface 21s on the inner peripheral side of the belt (lower side in fig. 2 and 3) of each rocking edge portion 25 and non-contact portion 27 approaches the back surface (back surface) as it moves away from the strut portion 22 (as it moves toward the inner peripheral side of the belt). A recessed portion 21r is formed on the rear surface of the cell 20 (main body portion 21) so as to be positioned on the rear surface side of the projection 21 p. When the belt 10 is assembled, the projections 21p of the adjacent cells 20 are loosely fitted into the recessed portions 21 r.

Each rocking edge portion 25 is a convex curved surface in a short belt shape, and in the present embodiment, is formed as a cylindrical surface (curved surface) having a predetermined radius of curvature and having a width in the radial direction. Each rocking edge portion 25 includes a contact line that brings the adjacent cells 20 into contact with each other and becomes a rotation fulcrum of both, and the position of the contact line varies within the range of the rocking edge portion 25 according to the gear ratio γ of the continuously variable transmission 1. In the present embodiment, the end of the rocking edge portion 25 located on the outer peripheral side of the belt 10 (the upper side in the figure, i.e., the pillar portion 22 side) is located radially outward of the saddle surface 23s (the top portion T) of the belt 10, and the end of the rocking edge portion 25 located on the inner peripheral side of the belt 10 (the lower side in the figure, i.e., the tapered surface 21s side) is located radially inward of the saddle surface 23s (the bottom portion) of the belt 10. Further, the rocking edge portion 25 may be formed on the rear surface of the single body 20.

The non-contact portion 27 is a strip-shaped recess that is open on the saddle surface 23s, extends in the width direction along the saddle surface 23s, and is formed on the front surface (one surface) of the main body 21 so as to separate the pair of rocking edges 25. The surface (bottom surface) of the non-contact portion 27 is recessed toward the back surface side from the surface of each rocking edge portion 25, and thus the thickness of the saddle surface 23s is smaller than the thickness te of the strut portion 22. The corner of the non-contact portion 27 and the edge of the main body 21 defining the non-contact portion 27 are rounded by chamfering or the like.

By forming such non-contact portions 27 in each element 20, the contact with the adjacent element 20 at a portion other than the rocking edge portion 25, that is, the contact between the adjacent element 20 and the non-contact portion 27 can be favorably suppressed in the transmission belt 10. As a result, it is possible to suppress the load from the central portion in the width direction of the cell 20 on which a large moment acts from being applied to the adjacent cell 20 to deform the cell 20, and it is possible to further improve the durability of each cell 20.

When torque is transmitted from the primary pulley 3 to the secondary pulley 5 via the transmission belt 10 including the plurality of cells 20 as described above, a compression force is applied to the plurality of cells 20 from the pulley 3, 5 side in a chord portion (hereinafter, referred to as a "compression-side chord portion") in which the cells 20 travel from the primary pulley 3 to the secondary pulley 5, of two chord portions that are portions not wound around the pulleys 3, 5 of the transmission belt 10. In the compression-side chord portion, the pressing amount (deformation amount) of the rocking edge portion 25 (body portion 21) which is the contact portion between the adjacent cells 20 is increased and the pressing amount of the pillar portion 22 is decreased, and thus, as can be seen from fig. 3, the center of curvature of the inner peripheral surface of the laminated ring 12 (innermost ring member 11i) substantially coincides with the center of curvature of an approximate curve (see the two-dot chain line in fig. 3) passing through the end portions 25a of the pair of rocking edge portions 25 on the outer peripheral side of the transmission belt 10. As a result, in the compression-side chord portion, as shown in the drawing, the plurality of cells 20 can be aligned in order, and the generation of vibration and noise can be suppressed when torque is transmitted.

However, in the belt 10 including the plurality of cells 20 each having the pair of the stay portions 22, since the area of the portion of the stay portion 22 protruding to the belt outer circumferential side from the laminated ring 12 is reduced, the stay portion 22 side of the cell 20 is liable to fall down in the rotation direction of the belt 10 or the direction opposite thereto, and as is apparent from fig. 4, the pressing amount (deformation amount) of the stay portion 22 may be partially larger than that of the rocking edge portion 25 (main body portion 21) in the compression side chord portion. In this case, the plurality of curvature centers of the approximate curves (see the two-dot chain lines in fig. 4) passing through the end portion 25a of the rocking edge portion 25 are formed in plurality and do not coincide with the curvature center of the laminated ring 12, and each of the plurality of curvature radii of the approximate curves is smaller than the curvature radius of the inner peripheral surface of the laminated ring 12 (the innermost ring member 11 i). As a result, when torque is transmitted, the plurality of cells 20 may be misaligned in the compression side string portion, and vibration and noise may occur.

Based on this, the present inventors paid attention to the fact that the width of the rocking edge portion 25 having a correlation with the pressing amount of the rocking edge portion 25 and the surface area of the portion of the stay portion 22 located further to the outer peripheral side of the transmission belt 10 than the rocking edge portion 25 having a correlation with the pressing amount of the stay portion 22 are concerned, and studied the relationship between the width and the surface area and the curvature of the laminated ring 12 in the compression-side chord portion and the curvature of the approximate curve passing through the rocking edge portion 25 in order to suppress the generation of vibration and noise when torque is transmitted between the pulleys 3, 5 by the transmission belt 10. Specifically, the sum of the widths a of the end portions 25a of the pair of swing edge portions 25 on the outer peripheral side of the belt is "a" (in the present embodiment, a is 2 × a, and about 5.7mm), and the sum of the surface areas S of the pair of column portions 22 in the flat portions on the outer peripheral side of the belt, i.e., the portions in contact with the adjacent cells 20 (see the hatched portions in fig. 2) of the swing edge portions 25 in the front surfaces of the cells 20 including the swing edge portions 25 is "S" (in the present embodiment, S is 2 × S, and about 20 mm)²) The change in curvature of the laminated ring 12 in the compression-side chord portion and the change in curvature of the approximate curve passing through the end 25a of the rocking edge portion 25 with respect to the value S/a are obtained by analysis. As a result, as shown in FIG. 5, it was found that when S/A.gtoreq.3.5 is satisfied, the center of curvature of the inner peripheral surface of the innermost ring member 11i (laminated ring 12) in contact with the top portion T of the saddle surface 23S at the compression-side chord portion substantially coincides with the center of curvature of the approximate curve passing through the end portion 25a of the rocking edge portion 25, and the radii of curvature of both substantially coincide.

As a result of the examination and analysis, in the transmission belt 10 of the present embodiment, the respective monomers 20 are formed so as to satisfy S/A.gtoreq.3.5. Thus, in the compression-side chord portion, the pressing amount of the rocking edge portion 25 can be made larger than the pressing amount of the strut portion 22, and the occurrence of irregularity in the arrangement of the plurality of cells 20 can be suppressed (see fig. 3). As a result, the transmission belt 10 including the plurality of cells 20 having the pair of column portions 22 can satisfactorily suppress the generation of vibration and noise when torque is transmitted between the pair of pulleys 3 and 5 of the continuously variable transmission 1.

Here, if S/a is equal to or greater than 3.5, the plurality of cells 20 can be aligned in order in the compression-side chord portion, and the generation of vibration and noise can be suppressed, but since there is a limit to the width expansion of the rocking edge portion 25 in the cell 20, the larger the value S/a, the larger the surface area (projected area) of the strut portion 22, and the larger the cell 20, the more the material cost increases. Therefore, the monomer 20 can also be formed so as to satisfy 3.5. ltoreq. S/A. ltoreq.5.0, more preferably, 3.5. ltoreq. S/A. ltoreq.4.0. This can satisfactorily suppress vibration and noise generated when torque is transmitted between the pair of pulleys 3, 5 of the continuously variable transmission 1 by the transmission belt 10, and can reduce the surface area (projected area) of the pair of the support portions 22, thereby reducing the material cost of the single body 20.

The sum a of the widths of the pair of rocking edges 25 may be the sum of the lengths of intersection lines of a straight line (a plane in contact with the saddle surface 23s at the top T) extending in the width direction through the top T of the saddle surface 23s and the surface of the rocking edge 25 in a plan view of the single body 20. That is, according to the analysis by the present inventors, when the sum of the lengths of the intersecting lines of the straight line extending in the width direction through the top portion T of the saddle surface 23S and the rocking edge portion 25 is "a", by forming the single body 20 so as to satisfy S/a ≧ 3.5, the center of curvature of the inner peripheral surface of the innermost ring member 11i (laminated ring 12) in contact with the top portion T of the saddle surface 23S and the center of curvature of the approximate curve of the intersecting line through the rocking edge portion 25 also substantially coincide in the compression-side chord portion, and the radii of curvature of both substantially coincide.

In the above embodiment, the end portion of the rocking edge portion 25 on the outer peripheral side of the belt is located radially outward of the saddle surface 23s (top portion T) in the belt 10, and the end portion of the rocking edge portion 25 on the inner peripheral side of the belt is located radially inward of the saddle surface 23s (bottom portion) in the belt 10. That is, the swing edge portion 25 may be formed such that an end portion located on the outer peripheral side of the conveyor belt or an end portion located on the inner peripheral side of the conveyor belt overlaps a straight line extending in the width direction through the swing edge portion 25 and the top portion T of the saddle surface 23 s.

The single body 20 has a bilaterally symmetrical outer shape, but is not limited thereto. That is, the single unit for the transmission belt of the present invention may be formed to have a left-right asymmetrical outer shape as the single unit 20B shown in fig. 6. As in the single body 20B shown in fig. 6, the projections 21p (and the recessed portions) may be formed not in the main body portion 21 but in the pillar portions 22. In the case where the protrusions 21p (and the recessed portions) are formed in the column parts 22 as described above, the sum of the surface areas S of the portions of the pair of column parts 22 in contact with the adjacent single bodies 20B out of the front and back surfaces of the single bodies 20B may be set to "S" described above, and the portions of the pair of column parts 22 in contact with the adjacent single bodies 20B may be the peripheral portions where the sagging occurs and the portions around the protrusions 21p are removed from the portions on the outer circumferential side of the belt than the swing edge portion 25. However, the portion of the pillar portion 22 that is located on the outer circumferential side of the belt with respect to the swing edge portion 25 and that contacts the adjacent cell 20B is not limited to a continuous region, and may be a region that is divided by the protrusion 21p, for example.

In the above-described belt 10, the pair of hook portions 22f are provided in each of the cells 20, and the stopper ring 15 is disposed between the laminated ring 12 and the hook portions 22f of the plurality of cells 20. That is, the structure of the strut member 22 is not limited to the strut member structure of the single body 20 described above, and the hook portion 22f may be omitted from the strut member 22 as in the single body 20B shown in fig. 6. Further, as in the case of the belt 10B shown in fig. 6, the retainer ring 15 may be omitted from the belt of the present invention. Further, the continuously variable transmission 1 may be configured such that: the primary shaft 2 and the secondary shaft 4 are selectively coupled with an input shaft, and the primary shaft 2 and the secondary shaft 4 are selectively coupled with a drive shaft of a vehicle.

As described above, the transmission belt of the present invention includes a plurality of monomers (20, 20B) and a ring (12), wherein the monomers (20, 20B) include: a main body part (21) having a saddle surface (23 s); and a pair of strut members (22) extending from the body portion (21) so as to be positioned on both sides of the saddle surface (23s) in the width direction, wherein the ring (12) is disposed between the pair of strut members (22) of the plurality of single members (20, 20B) so as to be in contact with the saddle surface (23s), and wherein the transmission belt is wound around a primary pulley (3) and a secondary pulley (5) of a continuously variable transmission (1), and wherein each of the single members (20, 20B) includes: a pair of convexly curved swing edge portions (25) formed on one of the front and back surfaces of the single body at an interval in the width direction so that at least a part of the swing edge portions straddles the pillar portion (22); and a non-contact portion (27) extending in the width direction along the saddle surface (23S) so as not to contact the adjacent cells (20, 20B) between the pair of swing edge portions (25), wherein S/A is 3.5 or more when the sum of the widths (a) of the end portions of the pair of swing edge portions (25) located on the outer peripheral side of the transmission belt (10, 10B) is defined as "A" and the sum of the surface areas (S) of the portions of the front surface or the back surface including the swing edge portions (25) located on the outer peripheral side of the transmission belt (10B, 20B) with respect to the swing edge portions (25) is defined as "S".

As described above, the present inventors have found that, when the sum of the widths of the ends of the pair of rocking edge portions on the outer peripheral side of the transmission belt is "a" and the sum of the surface areas of the portions of the pair of column portions on the front surface or the back surface on the outer peripheral side of the transmission belt than the rocking edge portions is "S", the single body is formed so as to satisfy S/a ≧ 3.5, whereby the center of curvature of the loop at the chord portion of the transmission belt where a compressive force acts on the single body substantially coincides with the center of curvature of the approximate curve passing through the rocking edge portions. Thus, in the transmission belt of the present invention including a plurality of cells each satisfying S/a ≧ 3.5, the amount of pressure applied to the chord portion of the transmission belt by the compressive force can be made larger at the rocking edge portion than at the strut portion, and the occurrence of misalignment in the arrangement of the plurality of cells can be suppressed. As a result, it is possible to favorably suppress the occurrence of vibration and noise when torque is transmitted between a pair of pulleys of a continuously variable transmission by a transmission belt including a plurality of single members having a pair of column portions.

In addition, the transmission belts (10, 10B) may satisfy 3.5. ltoreq. S/A. ltoreq.5.0, or may satisfy 3.5. ltoreq. S/A. ltoreq.4.0. This makes it possible to reduce the surface area (projected area) of the pair of column parts while satisfactorily suppressing vibration and noise generated when torque is transmitted between the pair of pulleys of the continuously variable transmission by the transmission belt, and to reduce the material cost of the single body.

Further, an end portion of the swinging edge portion (25) located on the outer peripheral side of the transmission belt (10, 10B) may be located further outward in the radial direction of the transmission belt (10, 10B) than the saddle surface (23s), and an end portion of the swinging edge portion (25) located on the inner peripheral side of the transmission belt (10, 10B) may be located further inward in the radial direction of the transmission belt than the saddle surface (23 s).

A single body (20, 20B) for a transmission belt of the present invention has a main body part (21) and a pair of strut parts (22), wherein the main body part (21) has a saddle-shaped surface (23s) which is in contact with a ring (12) of the transmission belt (10, 10B) wound around a primary pulley (3) and a secondary pulley (5) of a continuously variable transmission (1), the pair of strut parts (22) extend from the main body part (21) so as to be positioned on both sides in the width direction of the saddle-shaped surface (23s), and the single body (20, 20B) for a transmission belt includes: a pair of convexly curved swing edge portions (25) formed on one of the front and back surfaces of the single body at an interval in the width direction so that at least a part of the swing edge portions straddles the pillar portion (22); and a non-contact portion (27) extending in the width direction along the saddle surface (23S) so as not to contact the adjacent cells (20, 20B) between the pair of swing edge portions (25), wherein S/A is 3.5 or more, when the sum of the widths (a) of the end portions (25a) of the pair of swing edge portions (25) located on the outer peripheral side of the transmission belt (10, 10B) is defined as "A" and the sum of the surface areas (S) of the pair of column portions (22) on the outer peripheral side of the transmission belt relative to the swing edge portions (25) is defined as "S" in the front surface or the rear surface including the swing edge portions (25).

In the transmission belt including a plurality of the single bodies, the pressing amount of the rocking edge portion can be made larger than that of the pillar portion in the chord portion of the transmission belt in which the compressive force acts on the plurality of the single bodies, and the occurrence of the misalignment in the arrangement of the plurality of the single bodies can be suppressed. As a result, it is possible to favorably suppress the occurrence of vibration and noise when torque is transmitted between a pair of pulleys of a continuously variable transmission by a transmission belt including a plurality of single members having a pair of column portions.

The present invention is not limited to the above-described embodiments, and it is apparent that various modifications can be made within the scope of the invention. The above embodiment is only a specific embodiment of the invention described in the summary of the invention, and is not intended to limit the invention described in the summary of the invention.

Industrial applicability

The present invention can be applied to the manufacturing industry of continuously variable transmissions and transmission belts.