阅读说明：本技术 传动带用单体以及传动带 (Single body for transmission belt and transmission belt ) 是由 越智亨 三宅孝幸 于 2018-08-01 设计创作，主要内容包括：一种传送带的单体,卷绕于无级变速器的带轮,该单体包括：凸曲面状的摇摆边缘部,以至少部分地横跨支柱部的方式形成于正面以及背面中的一方,并且包括相邻的单体的接触线,所述接触线成为相邻的单体彼此的转动的支点,非接触部,是以与相邻的用单体不接触的方式沿着鞍形面在宽度方向上延伸的凹部,至少部分地在宽度方向上断开摇摆边缘部,非接触部的深度被设定为：该非接触部的传动带的内周侧的端部相比该传动带的卷绕半径变为最小时的接触线更靠内周侧,并且不到达主体部的内周侧的缘部。(A single unit of a conveyor belt wound around a pulley of a continuously variable transmission, comprising: a convexly curved rocking edge portion formed on one of the front surface and the rear surface so as to at least partially straddle the pillar portion, and including a contact line of adjacent cells, the contact line serving as a fulcrum of rotation of the adjacent cells, and a non-contact portion, which is a recess extending in the width direction along the saddle surface so as to be out of contact with the adjacent cells, at least partially interrupting the rocking edge portion in the width direction, the depth of the non-contact portion being set to: the end portion of the non-contact portion on the inner circumferential side of the belt is closer to the inner circumferential side than the contact line when the winding radius of the belt is minimized, and does not reach the edge portion on the inner circumferential side of the body portion.)

1. A monomer for a power transmission belt, comprising: a main body portion having a saddle surface that contacts a ring of a transmission belt wound around a primary pulley and a secondary pulley of a continuously variable transmission; and a pair of support column parts extending from the main body part so as to be positioned on both sides in the width direction of the saddle surface,

the monomer for the transmission belt comprises:

a convexly curved rocking edge portion formed on one of the front surface and the rear surface so as to at least partially straddle the pillar portion, and including a contact line of the adjacent belt units, the contact line serving as a fulcrum of rotation of the adjacent belt units,

a non-contact portion which is a concave portion extending in the width direction along the saddle surface so as not to contact with the adjacent belt single body and at least partially breaks the swing edge portion in the width direction,

the depth of the non-contact portion is set to: an end portion on the inner circumferential side of the belt of the non-contact portion is closer to the inner circumferential side than the contact line when the winding radius of the belt becomes minimum, and does not reach an edge portion on the inner circumferential side of the body portion.

2. The monomer for a power transmission belt according to claim 1, wherein,

the one of the front surface and the back surface includes a slope that is continuous with the rocking edge portion on the inner peripheral side of the contact line when the winding radius becomes smallest, and that approaches the other of the front surface and the back surface as going from the rocking edge portion toward the inner peripheral side,

the depth of the non-contact portion is set to: the inner peripheral end of the non-contact portion is positioned on the outer peripheral side of the belt or on a boundary line between the swing edge and the inclined surface.

3. The monomer for a power transmission belt according to claim 1 or 2, wherein,

the end portion of the rocking edge portion on the inner peripheral side is located on the inner peripheral side with respect to the saddle surface, and the end portion of the rocking edge portion on the outer peripheral side is located on the outer peripheral side with respect to the saddle surface.

4. The monomer for a power transmission belt according to any one of claims 1 to 3, wherein,

the contact line at which the winding radius becomes minimum is located on the inner circumferential side of the saddle surface, and the contact line at which the winding radius becomes maximum is located on the outer circumferential side of the transmission belt relative to the saddle surface.

5. The monomer for a power transmission belt according to any one of claims 1 to 4, wherein,

the non-contact portion is formed such that depths of both end portions in the width direction gradually decrease as approaching the rocking edge portion, and a portion between the both end portions has a constant depth, the depth of the non-contact portion being the constant depth.

6. The monomer for a power transmission belt according to claim 5, wherein,

the width of the portion of the non-contact portion having the constant depth is narrower than the width of the ring.

7. The monomer for a power transmission belt according to any one of claims 1 to 6, wherein,

the single belt body further includes a pair of hook portions projecting in the width direction from the free end portions of the pillar portions so as to face each other,

a retaining ring is disposed between the ring and the hook.

8. A power transmission belt comprising a plurality of cells and rings, the cells having: 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, the ring being disposed between the pair of strut parts of the plurality of cells so as to be in contact with the saddle surface, and the transmission belt being wound around a primary pulley and a secondary pulley of a continuously variable transmission,

each of the monomers has: a convexly curved rocking edge portion formed on one of the front surface and the rear surface so as to at least partially straddle the pillar portion, and including a contact line of the adjacent cells, the contact line serving as a fulcrum of rotation of the adjacent cells, and a non-contact portion which is a recess extending in the width direction along the saddle surface so as not to contact the adjacent cells and at least partially interrupts the rocking edge portion in the width direction,

the depth of the non-contact portion is set to: an end portion on the inner circumferential side of the belt of the non-contact portion is closer to the inner circumferential side than the contact line when the winding radius of the belt becomes minimum, and does not reach an edge portion on the inner circumferential side of the body portion.

Technical Field

The present invention relates to a single body for a transmission belt and a transmission belt having the same, the single body for a transmission belt comprising: a main body portion having a saddle surface that contacts a ring of a transmission belt wound around a pulley of a continuously variable transmission; and a pair of support column portions extending from the main body portion so as to be positioned on both sides in the width direction of the saddle surface.

Background

Conventionally, a single body for a transmission belt is known, which has: a main body part extending in the left and right direction; a pair of column parts extending upward from the left and right ends of the upper part of the main body part; and a rocking edge portion formed on the front main surface and extending in the left-right direction (see, for example, patent document 1). An inclined surface is formed on the front main surface of the single body so as to be positioned below the swing edge portion extending in the left-right direction, and the plate thickness of the single body becomes thinner toward the lower end. A recess (non-contact portion) extending in the vertical direction is formed in a substantially central portion in the lateral direction of the front main surface or the rear main surface of the single body. In the transmission belt including the single bodies, the adjacent single bodies are brought into contact with each other on both sides of the recess, so that the misalignment can be absorbed and the deflection can be suppressed.

Disclosure of Invention

However, in the single body described in patent document 1, the strength is reduced by forming a recess reaching the lower end (lower edge) of the single body on the front main surface or the rear main surface. Therefore, the strength of the single body itself is reduced, and the durability of the transmission belt including a plurality of the single bodies is reduced due to the deformation of the single body during torque transmission.

Therefore, an object of the present invention is to further improve the durability of a transmission belt by ensuring sufficient strength of a single belt for the transmission belt while allowing the single belt to contact with adjacent single belts only at swing edge portions located on both sides of a non-contact portion.

The monomer for the transmission belt of the present invention comprises: a main body portion having a saddle surface that contacts a ring of a transmission belt wound around a primary pulley and a secondary pulley of a continuously variable transmission; and a pair of support column portions extending from the body portion so as to be positioned on both sides in the width direction of the saddle surface, wherein the belt unit includes: a convexly curved rocking edge portion formed on one of the front surface and the rear surface so as to at least partially straddle the pillar portion, and including a contact line of the adjacent belt units, the contact line serving as a fulcrum of rotation of the adjacent belt units, a non-contact portion being a concave portion extending in the width direction along the saddle surface so as not to contact the adjacent belt units, the non-contact portion at least partially breaking the rocking edge portion in the width direction, a depth of the non-contact portion being set to: an end portion on the inner circumferential side of the belt of the non-contact portion is closer to the inner circumferential side than the contact line when the winding radius of the belt becomes minimum, and does not reach an edge portion on the inner circumferential side of the body portion.

In the single body for a transmission belt of the present invention, the rocking edge portion is at least partially broken in the width direction by the non-contact portion. The depth of the non-contact portion is set so that the end portion on the inner circumferential side of the belt of the non-contact portion is closer to the inner circumferential side than the contact line at which the winding radius of the belt becomes minimum and does not reach the edge portion on the inner circumferential side of the body portion. This makes it possible to bring the belt unit into contact with the adjacent unit only at the rocking edge portions located on both sides of the non-contact portion, and to suppress the thickness reduction of the belt unit, so that the strength of the belt unit can be sufficiently ensured, and the deformation of the belt unit during torque transmission can be suppressed. As a result, the durability of the transmission belt including the single body for a transmission belt of the present invention can be further improved.

Drawings

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

FIG. 2 is a schematic structural view showing a driving belt monomer of the present invention.

FIG. 3 is a schematic structural view showing a driving belt unit of the present invention.

Fig. 4 is a partially enlarged cross-sectional view showing a main part of the single body for a transmission belt of the present invention.

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) of a power generation source such as an engine (internal combustion engine) coupled to 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. The continuously variable transmission 1 may be configured such that the primary shaft 2 and the secondary shaft 4 are selectively coupled to the input shaft, and the primary shaft 2 and the secondary shaft 4 are selectively coupled to a drive shaft of the vehicle.

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 retaining 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 Drum (Drum) made of a steel plate, and are processed to have substantially the same thickness and different circumferential lengths set in advance. 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 retaining ring 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 retaining 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 retaining ring 15.

Each of the single bodies 20 is a member having a bilaterally symmetrical outer shape (planar shape) punched out of a steel plate by, for example, press working, and each of the single bodies 20 has, as shown in fig. 2: 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 outer circumferential side (the direction from the inner circumferential side to the outer circumferential side of the transmission belt 10 (stacked ring 12), i.e., upward in the drawing). Further, a hook portion 22f protruding 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 retaining ring 15. Each of the strut parts 22 of the single body 20 has a flat inner surface 22i inclined so as to be spaced apart from the saddle surface 23s toward the outer peripheral side, 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 retaining ring 15 is fitted into the ring housing 23 from between the pair of hook portions 22f of each unit 20. The retaining ring 15 is disposed between the outer peripheral surface of the outermost ring member 11o of the laminated ring 12 and the hook portions 22f of the individual cells 20, surrounds the laminated ring 12, and regulates the individual cells 20 from falling off the laminated ring 12 or the laminated ring 12 from falling off the individual cells 20 together with the pair of column portions 22. 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 retaining ring 15 is formed with a single or multiple openings (long holes), not shown, so that the retaining ring 15 can be easily elastically deformed, and the ease of assembly into 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 retaining ring 15, and tension or the like does not substantially act on the retaining ring 15 during operation of the continuously variable transmission 1. Therefore, in the single body 20, it is not necessary to increase the column part 22 and the hook part 22f in order to secure rigidity or the like, and the area of the portion of the column part 22 protruding to the outer peripheral side of the laminated ring 12 can be reduced compared to a normal single body in which the laminated ring is disposed on both sides of the head part extending to the outer peripheral side from the central part in the width direction of the body part. 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 on the inner circumferential side (the inner side in the radial direction of the laminated ring 12) of 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 toward the outer peripheral side. 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, the single body 20 includes a swing edge portion (contact region) 25 having a convex curved surface shape, a non-contact portion 27, and a tapered surface (inclined surface) 21s formed on the main body 21 on the front surface (one surface). The rocking edge portion 25 is a convex curved surface portion formed on the front surface of the single body 20 so as to straddle each of the pillar portions 22 and the body portion 21, and is in line contact with the back surface 20bs of the adjacent single body 20. That is, the rocking edge portion 25 includes a contact line of the adjacent cells 20, which becomes a fulcrum of rotation of the adjacent cells 20 with respect to each other.

The non-contact portion 27 is a strip-shaped recess formed in the body portion 21 so as to open on the saddle surface 23s and extend in the width direction along the saddle surface 23s, and partially breaks the rocking edge portion 25 in the width direction. As shown in fig. 3, the non-contact portion 27 is formed such that the depth of both end portions in the width direction gradually decreases as it approaches the rocking edge portion 25, and the portion between both end portions has a substantially constant depth d. The width w of the portion of the non-contact portion 27 having the substantially constant depth d is narrower than the width of the laminated ring 12. This can suppress stress concentration in the vicinity of both ends of the non-contact portion 27 in the width direction, and can further improve the durability of the single body 20.

The tapered surface 21s is a flat inclined surface that is continuous with the swing edge 25 and is formed so as to approach the rear surface 20bs of the single body 20 as the edge 21ei (lower side in the drawing) of the body 21 that extends from the swing edge toward the inner peripheral side of the belt 10. Further, on the tapered surface 21s, one protrusion (recess) 21p is formed so as to be positioned at the center portion in the width direction of the front surface of the body portion 21, and on the back surface 20bs of the single body 20 (body portion 21), a recess 21r is formed so as to be positioned on the back side of the protrusion 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.

In the present embodiment, as shown in fig. 2, the front surface (mainly, the front surface of the column part 22) of the cell 20 on the outer peripheral side (upper side in fig. 2) of the rocking edge part 25 and the back surface 20bs (the other surface) of the cell 20 are formed flat and parallel to each other. Thus, the pillar portion 22 of the cell 20 has a substantially constant thickness te. Further, since the non-contact portion 27 is recessed toward the back surface 20bs side from the surface of the rocking edge portion 25, the saddle surface 23s is smaller in thickness than the thickness te of the pillar portion 22. The inclination angle of the tapered surface 21s is set in consideration of the thickness te of the pillar portion 22 so that the tapered surface 21s does not contact the rear surface 20bs of the adjacent cell 20. A flat portion extending parallel to the rear surface 20bs of the single body 20 may be formed around the projection 21 p.

Fig. 4 is a partially enlarged sectional view showing a main part of the single body 20. As shown in fig. 4, the rocking edge portion 25 is formed to smoothly continue with the front surface of the pillar portion 22 and the tapered surface 21s and to have a width in the radial direction of the belt 10. In the present embodiment, the swing edge portion 25 has a predetermined radius of curvature, and is formed of a cylindrical surface that contacts both the front surface of the pillar portion 22 and the tapered surface 21 s. However, the rocking edge portion 25 may be formed of a convex curved surface such as an elliptic cylindrical surface other than a cylindrical surface.

As described above, the rocking edge portion 25 includes the contact line that serves as the fulcrum of the rotation of the adjacent cells 20, but the position of the contact line varies from the end 25o on the outer circumferential side of the belt 10 of the rocking edge portion 25 (hereinafter referred to as the "outer circumferential end portion") to the end 25i on the inner circumferential side of the belt 10 (hereinafter referred to as the "inner circumferential end portion") based on the gear ratio γ of the continuously variable transmission 1. That is, 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, the contact line between the adjacent cells 20 is closest to the outer peripheral side of the transmission belt 10 in the rocking edge portion 25 at the chordal portion that is the portion of the transmission belt 10 not wound around the pulleys 3, 5. In addition, the inclination of the cells 20 is theoretically maximized when the winding radius of the belt 10 is minimized, and thus the contact line between the adjacent cells 20 is closest to the inner circumferential side of the belt 10 in the rocking edge portion 25.

Therefore, the rocking edge portion 25 (such as the radius of curvature of the cylindrical surface) is designed such that the outer peripheral end portion 25o (the boundary line between the front surface of the pillar portion 22 and the rocking edge portion 25) is on the outer peripheral side of the designed (theoretical) contact line in the chord portion. The oscillating edge portion 25 is designed such that the inner peripheral end 25i (the boundary line between the tapered surface 21s and the oscillating edge portion 25) is positioned on the inner peripheral side of the contact line 25cmin at which the winding radius of the belt 10 becomes minimum. Thereby, the rocking edge portion 25 is continuous with the tapered surface 21s on the inner peripheral side of the contact line 25 cmin. In the present embodiment, as shown in the drawing, the rocking edge portion 25 is designed so that the inner peripheral side end portion 25i is sufficiently (to some extent) away from the contact line 25cmin toward the inner peripheral side in consideration of manufacturing tolerances of the single body 20 and the like, a deformation amount during operation, and the like.

Further, the range from the outer peripheral end 25o of the wobbling edge portion 25 to the contact line 25cmin includes the contact line 25cmax when the winding radius of the drive belt 10 becomes maximum. In the present embodiment, the rocking edge portion 25 is designed such that the contact line 25cmin when the winding radius becomes minimum is on the inner peripheral side of the saddle surface 23s (bottom portion), and the contact line 25cmax when the winding radius becomes maximum is on the outer peripheral side of the saddle surface 23s (top portion T). This can further shorten the distance between the contact lines between the saddle surface 23s of the transmission belt 10 of the pulleys 3 and 5 wound around the single unit 20 in the radial direction, and therefore, the angular velocity difference between the laminated ring 12 and the single unit 20 can be further reduced, and the friction loss caused by the relative sliding between the laminated ring 12 and the single unit 20 can be favorably reduced. Further, the winding radius of the transmission belt 10 becomes minimum when the speed ratio γ of the continuously variable transmission 1 becomes minimum and becomes maximum when the speed ratio γ becomes maximum, or becomes minimum when the speed ratio γ becomes maximum and becomes maximum when the speed ratio γ becomes minimum.

Here, as described above, by forming the non-contact portion 27, which is a recessed portion extending along the saddle surface 23s, in each cell 20, the contact with the adjacent cell 20 at a portion other than the rocking edge portion 25 can be suppressed in the transmission belt 10, and the durability of each cell 20 can be improved. That is, by not bringing the non-contact portion 27 of each cell 20 into contact with the adjacent cell 20, 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 thus, the durability of each cell 20 can be further improved.

However, if the end of the non-contact portion 27 on the inner circumferential side of the belt 10 is located on the outer circumferential side of the contact line 25cmin, each element 20 comes into contact with the portion on the inner circumferential side of the non-contact portion 27 of the adjacent element 20 when the winding radius of the belt 10 is minimized. On the other hand, when the non-contact portion 27 is formed so that the front surface of the single body 20 reaches the edge portion 21ei on the inner peripheral side of the body portion 21, the strength of the single body 20 may be reduced, and the durability of the transmission belt 10 including a plurality of single bodies 20 may be reduced.

Based on this, as shown in fig. 4, the depth (the above-described constant depth) d of the non-contact portion 27 of the single body 20 is determined such that an end portion 27i on the inner peripheral side of the belt 10 of the non-contact portion 27 (hereinafter referred to as "inner peripheral end portion") is on the inner peripheral side of a contact line 25cmin at which the winding radius of the belt 10 becomes minimum and on the outer peripheral side of an inner peripheral end portion 25i of the rocking edge portion 25 (a boundary line between the tapered surface 21s and the rocking edge portion 25). That is, the bottom surface 27b of the non-contact portion 27 is closer to the back surface 20bs of the single body 20 than the contact line 25cmin, and is further from the back surface 20bs than the inner circumferential side end 25i of the rocking edge portion 25.

Thus, the non-contact portion 27 can break the rocking edge portion 25 into a pair of actual contact regions 25A (regions where portions located on the inner peripheral side of the contact line 25cmin are mainly removed from the rocking edge portion 25, see the hatched portion in fig. 2), so that each cell 20 and the adjacent cell 20 can be brought into contact only with the rocking edge portion 25 located on both sides of the non-contact portion 27, and the non-contact portion 27 can be made as shallow as possible, whereby thinning of the cell 20 can be suppressed favorably. As a result, the strength of each element 20 can be sufficiently ensured, and the deformation of each element 20 during torque transmission can be suppressed, so that the durability of the transmission belt 10 including a plurality of elements 20 can be further improved.

As described above, the rocking edge portion 25 of the single body 20 is designed such that the contact line 25cmin when the winding radius becomes minimum is located on the inner peripheral side of the saddle surface 23s, and the contact line 25cmax when the winding radius becomes maximum is located on the outer peripheral side of the saddle surface 23 s. In the single body 20, by making the inner peripheral end portion 27i of the non-contact portion 27 more outer than the inner peripheral end portion 25i of the rocking edge portion 25, the non-contact portion 27 can be made shallower than in a case where, for example, the contact line 25cmax when the winding radius becomes maximum is provided more inner than the saddle surface 23s in the radial direction of the belt 10.

Further, depending on the specification (thickness, etc.) of the single body 20, the depth d of the non-contact portion 27 may be set so that the inner peripheral end 27i is positioned on the inner peripheral end 25i of the rocking edge 25 (the boundary line between the tapered surface 21s and the rocking edge 25). Further, depending on the curvature of the rocking edge portion 25 and the inclination angle of the tapered surface 21s, the depth d of the non-contact portion 27 may be set so that the inner peripheral end portion 27i is located on the inner peripheral side of the inner peripheral end portion 25i of the rocking edge portion 25 in a range not reaching the inner peripheral edge portion 21ei of the body portion 21.

Further, if the inner peripheral end 25i of the rocking edge 25 is located on the inner peripheral side of the saddle surface 23s (bottom) and the outer peripheral end 25o is located on the outer peripheral side of the saddle surface 23s (top T), the contact line 25cmin at which the winding radius becomes minimum may be located on the outer peripheral side of the saddle surface 23s (bottom), and the contact line 25cmax at which the winding radius becomes maximum may be located on the inner peripheral side of the saddle surface 23s (top T). The rocking edge 25 may be formed such that the inner peripheral end 25i or the outer peripheral end 25o overlaps a straight line (see a chain line in fig. 4) extending in the width direction through the rocking edge 25 and the top T of the saddle surface 23 s. The rocking edge portion 25 and the non-contact portion 27 may be formed on the back surface 20bs of the single body 20.

As described above, the single body (20) for a transmission belt of the present invention comprises: a main body part (21) having a saddle surface (23s) that comes into contact with a ring (12) of a transmission belt (10) wound around a primary pulley (3) and a secondary pulley (5) of a continuously variable transmission (1); and a pair of strut members (22) extending from the main body (21) so as to be positioned on both sides of the saddle surface (23s) in the width direction, wherein the single belt body comprises: a convexly curved swing edge portion (25) formed on one of the front surface and the rear surface so as to at least partially straddle the pillar portion (22), and including a contact line of the adjacent belt units, the contact line serving as a fulcrum of rotation of the adjacent belt units (20), a non-contact portion (27) being a recess extending in the width direction along the saddle surface (23s) so as to be out of contact with the adjacent belt units (20), the swing edge portion (25) being at least partially broken in the width direction, a depth (d) of the non-contact portion (27) being set to: an end portion (27i) of the non-contact portion (27) on the inner peripheral side of the transmission belt (10) is located on the inner peripheral side of the contact line (25cmin) when the winding radius of the transmission belt (10) is minimized, and does not reach an edge portion (21ei) of the main body portion (21) on the inner peripheral side.

In the single body for a transmission belt of the present invention, the rocking edge portion is at least partially broken in the width direction by the non-contact portion. The depth of the non-contact portion is set so that the end portion on the inner circumferential side of the belt of the non-contact portion is closer to the inner circumferential side than the contact line at which the winding radius of the belt becomes minimum and does not reach the edge portion on the inner circumferential side of the body portion. This makes it possible to bring the belt unit into contact with the adjacent unit only at the rocking edge portions located on both sides of the non-contact portion, and to suppress the thickness reduction of the belt unit, so that the strength of the belt unit can be sufficiently ensured, and the deformation of the belt unit during torque transmission can be suppressed. As a result, the durability of the transmission belt including the single body for a transmission belt of the present invention can be further improved.

Further, the one of the front surface and the back surface may include a slope (21s), the slope (21s) being continuous with the swing edge (25) on the inner peripheral side of the contact line (25cmin) when the winding radius becomes minimum, and approaching the other one (20bs) of the front surface and the back surface from the swing edge (25) toward the inner peripheral side. The depth (d) of the non-contact portion (27) is set to: the inner peripheral end (27i) of the non-contact portion (27) is located further on the outer peripheral side of the transmission belt (10) than a boundary line (25i) between the swing edge (25) and the inclined surface (21s) or on the boundary line (25 i). This makes it possible to bring the single belt body into contact with the adjacent single belt body only at the rocking edge portions located on both sides of the non-contact portion, and to further reduce the non-contact portion, thereby making it possible to favorably suppress the thickness reduction of the single belt body.

Further, an end portion (25i) of the rocking edge portion (25) on the inner peripheral side may be positioned on the inner peripheral side of the saddle surface (23s), and an end portion (25o) of the rocking edge portion (25) on the outer peripheral side of the transmission belt may be positioned on the outer peripheral side of the transmission belt (10) on the saddle surface (23 s).

The contact line (25cmin) at which the winding radius is minimized may be positioned on the inner circumferential side of the saddle surface (23s), and the contact line (25cmax) at which the winding radius is maximized may be positioned on the outer circumferential side of the transmission belt (10) relative to the saddle surface (23 s). This makes it possible to further reduce the non-contact portion and further shorten the distance between the contact lines between the saddle-shaped surface of the transmission belt and the single body in the radial direction during torque transmission, and therefore, the angular velocity difference between the ring and the single body for the transmission belt can be further reduced, and the friction loss caused by the relative sliding between the ring and the single body for the transmission belt can be favorably reduced.

Further, the non-contact portion (27) may be formed such that the depth of both end portions in the width direction gradually decreases as it approaches the rocking edge portion (25), and a portion between the both end portions has a constant depth (d), and the depth of the non-contact portion (27) may be the constant depth (d). This can suppress stress concentration in the vicinity of both ends in the width direction of the non-contact portion, and can further improve the durability of the single belt for a transmission belt.

Further, the width (w) of the portion of the non-contact portion (27) having the constant depth (d) may be narrower than the width of the ring (12).

The single belt body (20) further includes a pair of hook portions (22f), the pair of hook portions (22f) protruding in the width direction from the free end portions of the pillar portions (22) so as to face each other, and a retaining ring (15) may be disposed between the ring (12) and the hook portions (22 f). Thus, the retaining ring can prevent the belt monomer from falling off the ring or prevent the ring from falling off the plurality of belt monomers.

The transmission belt (10) of the present invention includes a plurality of monomers (20) and a ring (12), wherein the monomers (20) have: 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 is disposed between the pair of strut members (22) of the plurality of cells (20) so as to be in contact with the saddle surface (23s), and wherein the transmission belt (10) is wound around a primary pulley (3) and a secondary pulley (5) of a continuously variable transmission (1), wherein each of the cells (20) has: a convexly curved rocking edge portion (25) formed on one of the front surface and the rear surface so as to at least partially straddle the pillar portion (22), and including a contact line of the adjacent cells (20) that serves as a fulcrum of rotation of the adjacent cells (20), a non-contact portion (27) that is a recess extending in the width direction along the saddle surface (23s) so as to be out of contact with the adjacent cells (20) and that at least partially breaks the rocking edge portion (25) in the width direction, a depth (d) of the non-contact portion (27) being set such that: an end portion (27i) of the non-contact portion (27) on the inner peripheral side of the transmission belt (10) is located on the inner peripheral side of the contact line (25cmin) when the winding radius of the transmission belt (10) is minimized, and does not reach an edge portion (21ei) of the main body portion (21) on the inner peripheral side.

In the transmission belt of the present invention, since the thickness reduction of each element can be suppressed, the strength of each element can be sufficiently ensured while the adjacent elements are brought into contact only with the rocking edge portions located on both sides of the non-contact portion, and the deformation of the elements during torque transmission can be suppressed. As a result, the durability of the transmission belt of the present invention can be further improved.

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.