JP2001173730A - Belt for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt for a continuously variable transmission capable of reducing vibration and noise generated when an element is wound around a pulley and when a recessed part and a protrusion are engaged with each other between andjoining elements. SOLUTION: A plurality of elements 3 are supported to an endless carrier 2 formed in a belt shape, recessed parts 7 wherein one protrusion 6 is engaged with one surface F1 of each element and the other protrusion 6 of an adjoining element 3 is engaged with the other surface F2 are formed, each inner and outer inside surface fb and outside surface fg opposed to each belt width direction Y2 of the recessed parts 7 and the protrusions 6, are formed as each nearly parallel surface in a belt diameter direction Y1 and a belt length direction X, and crowning treatment is executed on at least one surface of a recessed part side surface and a protrusion side surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a continuously variable transmission (CV).
The present invention relates to a steel continuously variable transmission belt used in T) and wound around a pair of V-shaped grooved pulleys.

[0002]

2. Description of the Related Art A continuously variable transmission (CVT) is known as one of transmissions provided in a torque transmitting system of a vehicle or the like. The continuously variable transmission (CVT) has an input shaft and an output shaft. A belt for a continuously variable transmission made of steel is wound between a pair of pulleys with V-grooves respectively arranged on the input shaft and the output shaft by switching the belt winding radius of each pulley with V-groove. And the rotational ratio between them is increased or decreased. The belt for a continuously variable transmission includes an endless carrier in the form of an endless belt, and is formed by attaching a number of thin plate-like elements to the endless carrier so as to be relatively movable. Each of the elements has a projection formed on one of its opposing surfaces and a concave portion formed on the other opposing surface, and the projection is fitted into the concave portion to restrict displacement between adjacent elements.

When such a belt for a continuously variable transmission rotates, each part of the belt alternately moves between a linear moving part between a pair of pulleys and a bending moving part which is a pulley wrapping part. As shown in FIGS. 8 (a) and 8 (b), the main portion 101 and the thin portion 102 of each element 100 have a tilt angle θ with respect to a boundary (also referred to as a locking edge) a between them as a fulcrum. Concave portions 1 facing each other by repeating tilt displacement
03 and the projection 104 are repeatedly fitted and detached from each other. Here, the protrusion 104 is formed as a conical outer surface, and the concave portion 103 is formed as a concave hole having a conical inner surface that fits the protrusion 104 with a uniform gap therebetween, thereby enabling mutual engagement and disengagement. . As described above, when the projection 104 and the concave portion 103 are displaced by the inclination angle θ, the innermost surface of the protrusion 104 and the inner surface of the concave portion 103 can be in contact with each other within a range in which mutual decoupling operation and interference during relative displacement do not occur. Side gap t2 with the outer surface of the projection 104
It is preferable that is smaller in order to exhibit the function of regulating relative displacement.

During the movement of the element 100 in the linear moving portion, the opposing surfaces f1 and f2 of the main portions 101 abut each other at a position where the element reference lines L coincide with each other (see FIG. 8 (a)). (See two elements on the right side), projection 104
As shown in FIG. 8B, the recess 104 and the recess 103 are not in contact with each other.
Is kept substantially constant. However, it is assumed that the belt for the continuously variable transmission reaches the bending moving part from the linear moving part and is wound around the V-groove pulley. In this case, the pair of adjacent elements 100 is different from each other and has a different contact surface with the pulley, particularly when the winding radius is changed, the directions are orthogonal to the belt length direction X and the belt radial direction Y1. And the belt width direction (FIG. 8A,
(In (b), the direction perpendicular to the paper surface). in this case,
When the tip of the projection 104 having a conical outer surface is relatively displaced by the relative displacement in contact with the concave portion 103 having the conical inner surface, when the projection 104 moves from the bending moving portion to the linear moving portion, Further, sliding displacement is performed, and the mutual positioning of the respective elements 100 is properly performed. An example of a belt for a continuously variable transmission including the same elements as described above is disclosed in Japanese Patent No. 2700334.

[0005]

The belt for a continuously variable transmission shown in FIGS. 8 (a) and 8 (b) and the belt for a continuously variable transmission disclosed in Japanese Patent No. By fitting the concave portion 103 of the element 100 and the projection 104 of the other element 100, positional adjustment can be performed at the time of meshing with each other while allowing displacement between adjacent elements. However, since the shapes of the projections and recesses of the elements described in the above publication are axially symmetric, when the continuously variable transmission belt reaches the bending movement portion from the linear movement portion, the recesses and projections are accompanied by the relative displacement of each element. Of the belt in the width direction. For this reason, the level of noise and vibration accompanying the collision when the element is wound around the pulley is relatively large, and the noise and vibration generated by the collision between the concave portion 103 and the projection 104 when each element separates from the pulley are reduced. The level of vibration is also relatively large, and it is desired to reduce these.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a stepless structure capable of reducing noise and vibration when an element is wound around a pulley or when a recess and a projection between adjacent elements are engaged with each other. It is an object of the present invention to provide a transmission belt.

[0007]

According to a first aspect of the present invention, a plurality of elements are supported on an endless band-shaped carrier, and a projection is provided on one surface of each element and on the other surface. In the continuously variable transmission belt in which the recesses with which the protrusions of the adjacent elements are engaged are formed, the inner and outer side surfaces of the recesses and the protrusions facing the belt width direction are respectively substantially in the belt radial direction and the belt length direction. It is formed as a parallel surface, and at least one of the side surface of the concave portion and the side surface of the projection is subjected to a crowning process. As described above, when the inner and outer side surfaces of the concave portion and the projection facing the belt width direction are formed as surfaces substantially parallel to the belt radial direction and the belt length direction, respectively, even if each element is relatively displaced, the concave portion and the projection are The gap (clearance) in the belt width direction is substantially constant. For this reason, while ensuring that each element is smoothly wound around the pulley, the displacement of the relative position of the element in the belt width direction can be reduced to reduce noise and vibration caused by the collision of the element with the pulley, and Since the crowning process is performed on at least one of the side surface of the recess and the side surface of the protrusion, the engagement between each projection and each recess when each element is detached from the pulley is smoothly performed, and the noise and vibration generated due to the collision at the time of engagement. And durability can be improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A belt for a continuously variable transmission to which the present invention is applied will be described below with reference to FIGS. The continuously variable transmission belt 1 is used for a continuously variable transmission (CVT), and for example, as shown in FIG. 6, an input pulley P1 integrated with an input shaft IS of the continuously variable transmission and an integrated output pulley OS. By being wound around the output pulley P2 and switching the belt winding radius of each pulley to the V groove, the input shaft IS and the output shaft O
The rotation ratio between S and S is increased or decreased. A belt 1 for a continuously variable transmission is formed by a pair of endless carriers 2 in the form of an endless band and a number of elements 3 movably attached to these carriers.
1 and P2, and a bending movement part E2 wound around the input / output pulleys P1 and P2 so as to be alternately rotatable.

The endless carrier 2 shown in FIG. 2 uses a laminate in which a plurality of thin steel plates are stacked and has a rectangular cross section to form a band, and the band-shaped laminate is continuously formed in an annular shape to have flexibility. Formed as a ring. Element 3 is shown in FIG.
As shown in (a) to (c), a substantially triangular strip-shaped main portion 4 is provided.
And the belt inner peripheral side of the belt inner peripheral edge of the main part (Fig. 3
(A) a thin-walled thin portion 5 extending downwardly;
And a straight boundary portion (also referred to as a locking edge) a between the thin section 5 and the thin section 5.

The main part 4 is a piece having a certain thickness, and the opposite faces F1 and F2 are kept parallel to each other on the front and back (here, the left side in FIG. 1, which is the direction of the belt rotational movement). So that it closely overlaps with other adjacent elements. Cuts 401 are formed on the left and right sides of the main part 4 when viewed from the front, and projections 6 and recesses 7 are formed on the front and back of the central part. The cut 401 is formed as a rectangular cut into which the endless carrier 2 is fitted so as to be relatively displaceable.

As shown in FIGS. 5 (a) and 5 (b), the recess 7 is formed so as to be recessed in the belt length direction X with respect to the element 3, and formed so that the element center line L is located at the center thereof. Is done. The concave portion 7 is formed as a rectangular concave hole that expands from the deepest portion side toward the opening side as a whole, and has a substantially rectangular bottom surface fc parallel to the facing surface F2 on the back side of the element 3 at the deepest portion.
Is formed. Of the inner peripheral wall of the concave portion 7, the slope in the radial direction Y <b> 1 of the belt orthogonal to the belt length direction X and the inner peripheral side of the belt (the lower side in FIG. 5A) descends from the deepest part toward the opening. The belt is formed on a belt inner peripheral side inner surface fa 'as a plane, and the outer peripheral side (upper side in FIG. 5A) of the belt is formed on a belt outer peripheral side inner surface fa as an inclined plane which rises toward the opening from the deepest part. . The left and right inner side surfaces fb and fb of the inner peripheral wall of the concave portion 7 facing the belt width direction Y2 orthogonal to the belt length direction X are in the belt radial direction Y1 (FIG. 5B).
And a plane substantially parallel to the belt length direction X, that is, as shown in FIGS. 3 (c) and 5 (b), a plane orthogonal to the rear facing surface F2.

On the other hand, the projection 6 is shown in FIGS. 4, 5 (a) and 5 (b).
As shown in the figure, the element 3 is formed so as to protrude in the belt length direction X, is formed so that the element center line L is located at the center thereof, and expands from the top toward the base end as a whole outer peripheral wall. It is formed in a rectangular projection. At the top of the projection 6, a top surface fd, which is substantially parallel to the facing surface F1 on the front side of the element 3 and is a substantially rectangular plane smaller than the above-described bottom surface fc, is formed. Of the outer peripheral wall of the protrusion 6, in the radial direction Y1 of the belt and on the inner peripheral side of the belt (the lower side in FIG. 5A), it descends from the top to the base end, and the above-described inner peripheral side of the belt Inner surface f
belt inner peripheral side outer surface f as an inclined plane smaller than a '
e ′ is formed and the outer peripheral side of the belt (upper side in FIG. 5A)
, A belt outer peripheral side outer surface fe as an inclined plane smaller than the above-described belt outer peripheral side inner surface fa is formed. The left and right outer surfaces fg, fg of the outer peripheral wall of the protrusion 6 that face the belt width direction Y2 orthogonal to the belt length direction X are planes substantially parallel to the belt radial direction Y1 and the belt length direction X, respectively. That is, as shown in FIG. 3 (c), it is formed as a surface orthogonal to the front facing surface F1. Moreover, each of the outer surfaces fg, fg is formed as a surface smaller than the above-mentioned left and right inner surfaces fb, fb.

The outer peripheral surface fe 'of the belt, the outer peripheral surface fe' of the belt, the outer peripheral surface fe of the belt, and the left and right outer surfaces fg, which are the outer peripheral surfaces of the above-mentioned projections 6, are formed as flat surfaces, respectively. In this case, a so-called crowning process is performed such that the center side of the plane slightly protrudes and the peripheral side retreats. Specifically, as shown in FIG. 7, the outer peripheral surface fe of the belt outer peripheral side of the protrusion 6 and the outer peripheral surface f
The radius of curvature r of e ′ is set to each cut 401 of the element 3.
R = W / (2 sin α) determined by the maximum deviation angle α between the endless carrier 2 and the length W of the protrusion in the belt width direction Y2.
And the radius of curvature R of the outer peripheral surfaces fg, fg of the projections is determined by the deviation angle α and the length h of the projections in the belt radial direction Y1.
h / (2 sin α). By performing such a crowning process, the belt inner peripheral side outer surface fe ′, the belt outer peripheral side outer surface fe, and the left and right outer surfaces fg of the protrusion 6 are formed.
Is a belt inner peripheral side inner surface f which is an inner peripheral wall side of the concave portion 7 side.
When a ′, the belt outer peripheral side inner surface fa and the left and right inner side surfaces fb contact each other, they can contact each other near the center of the plane, so that relatively smooth sliding can be secured and durability can be secured.

Next, as shown in FIGS. 3 (a) and 3 (b), the thin section 5 extending from the main section 4 has an inclination angle θ (for example, 5 ° here) immediately below the boundary section a. An inclined surface F3 is formed, and a bifurcated portion that is easy to reduce the weight is formed below the inclined surface F3. Here, when the adjacent elements 3 move on the bending movement portion E2 wound around the input / output pulleys P1 and P2, the respective elements 3 mutually tilt and displace with the boundary a as a fulcrum ( The two thin elements 5 are wound around each pulley in a state in which they come into close contact with each other, and are appropriately set so as to be movable.

Here, as shown in FIG.
And the projection 6 mesh with each other with the element center lines L aligned with each other, the gap in the radial direction Y1 of the belt, that is, the side portion between the belt inner peripheral side inner surface fa ′ and the belt inner peripheral side outer surface fe ′. Gap tb 'and belt outer peripheral side inner surface f
a and a side gap tb between the belt outer peripheral side outer surface fe and
The predetermined amount is set so as to prevent interference at the time of engagement and disengagement between the projection and the projection 6, and to smoothly perform relative displacement.
On the other hand, as shown in FIG.
And mesh with each other in a state where the element center lines L are aligned with each other, a gap facing the belt width direction Y2,
That is, the left and right inner surfaces fb, fb and the left and right outer surfaces fb
A relatively small amount is set for each side gap th between g and fg by not taking into account the relative displacement in the belt width direction Y2 when the concave portion 7 and the protrusion 6 are disengaged from each other.

The operation of the above-described continuously variable transmission belt 1 rotating and moving between the input / output pulleys P1 and P2 will be described. First, each element 3 of the linear moving portion E1 is supported by a pair of endless carriers 2, and the opposing surfaces F1 and F2 on the front and back sides of each main portion 4 are formed in parallel.
And the concave portion 7 are fitted to each other, so that the elements adjacent to each other can be moved in a straight line in a dense state without displacement in the belt radial direction Y1 and the belt width direction Y2 perpendicular to the belt length direction X. .

Each element 3 is sequentially wound around the pulley P1 or P2 from the linear moving section E1, and is bent.
And reach In this case, the adjacent elements 3 are sequentially inclined and displaced with the boundary part a as a fulcrum, and reach a state where the thin sections 5 come into close contact with each other. As shown in FIG. 5B, the rotation is relatively performed with the portion a as a fulcrum, and as shown in FIG.
2), the elements 3 are displaced from each other toward the initial position (p1), and the respective elements 3 are sequentially smoothly wound around the pulley P1 or P2. At this time, the side gap th (clearance) between the inner and outer side surfaces of the concave portion 7 and the protrusion 6 is substantially constant regardless of the assumed displacement of each element 3, so that the relative position shift in the belt width direction Y2 is small. In addition, noise and vibration caused by the collision of the element 3 with the pulley P1 or P2 can be reduced, and the durability can be improved.

Next, the linear moving part E1 is moved from the bending moving part E2.
, And each element 3 is sequentially turned into a pulley P1 or P2.
Leave more. In this case, the adjacent elements 3 are sequentially inclined and displaced with the boundary part a as a fulcrum, the thin sections 5 of the adjacent elements 3 are separated from each other, and the front and rear opposing surfaces F1 and F2 of the main part 4 are sequentially superimposed. Are linearly aligned in a state where the elements are locked to the endless carrier. At this time, at the engagement end position (p2), the side gap th (clearance) between the projection 6 and the recess 7 that mesh with each other is made relatively small, and the side surface of the projection 6 is subjected to crowning. , And the collision energy between the projections 6 and the recesses 7 can be reduced, and the noise and vibration generated by the meshing collision between the projections 6 and the recesses 7 when each element 3 separates from the pulley P1 or P2 can be reduced accordingly. , Durability can be improved.

The belt 1 for a continuously variable transmission shown in FIG. 1 is configured so that each element 3 is supported by a pair of endless carriers 2, but in some cases, each element is supported by a single endless carrier. The present invention may be applied to a constructed belt for a continuously variable transmission, and the same effects as those of the continuously variable transmission belt 1 of FIG. 1 can be obtained in this case.

[0020]

As described above in detail with the embodiments, according to the continuously variable transmission belt of the present invention, the inner and outer side faces of the concave portions and the projections facing the belt width direction are formed in the belt radial direction and the belt radial direction. Since the belt is formed by surfaces substantially parallel to the length direction and at least one of the side surface of the recess and the side surface of the protrusion is subjected to a crowning process, the clearance between the protrusion and the recess when the belt moves from the linear moving portion to the bending moving portion. Is regulated and constant, so that noise and vibration caused by the collision of each element with the pulley can be reduced, and the engagement between the projection and the concave portion when each element separates from the pulley can be performed smoothly. The noise and vibration generated due to the collision can be reduced.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of a belt for a continuously variable transmission according to an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of the continuously variable transmission belt of FIG.

3A and 3B are enlarged views of elements of the belt for the continuously variable transmission shown in FIG. 1, wherein FIG. 3A is a front view, FIG. 3B is a side view, and FIG.

FIG. 4 is an enlarged cutaway perspective view of a main part of an element of the continuously variable transmission belt of FIG. 1;

5 is an enlarged cross-sectional view of a main part of an element in FIG. 4 and an adjacent element (not shown), wherein FIG.
(B) is a sectional view taken along line BB.

FIG. 6 is a schematic side view of a state where the continuously variable transmission belt of FIG. 1 is wound around a pair of pulleys.

FIG. 7 is a curvature radius setting diagram accompanying the crowning processing of the continuously variable transmission belt of FIG. 1;

8A and 8B show a conventional belt for a continuously variable transmission, wherein FIG. 8A is an enlarged sectional view of a main part, and FIG. 8B is a partially cutaway sectional view when meshing is completed.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 belt for continuously variable transmission 2 endless carrier 3 element 6 protrusion 7 concave portion fb inner surface fg outer surface th side gap F1 one surface (front surface) F2 the other surface (back surface) X belt length direction Y1 Belt radial direction Y2 Belt width direction

Claims (1)

[Claims] 1. A continuously variable transmission belt in which a plurality of elements are supported by an endless belt-shaped carrier, and a projection is formed on one surface of each element and a recess is engaged with a projection of an element adjacent to the other surface. , The inner and outer side surfaces of the concave portion and the protrusion facing the belt width direction are respectively formed as surfaces substantially parallel to a belt radial direction and a belt length direction, and at least one of the concave side surface and the protrusion side surface is crowned. A belt for a continuously variable transmission, characterized by having been subjected to the following.