JP4761121B2 - Power transmission chain and power transmission device including the same - Google Patents

Description

  The present invention relates to a power transmission chain and a power transmission device including the power transmission chain.

An endless power transmission chain used in a power transmission device such as a pulley-type continuously variable transmission (CVT) of an automobile has a plurality of links arranged in the chain traveling direction and links adjacent to each other in the chain traveling direction. Are connected by a pair of pins capable of rolling with each other (see, for example, Patent Documents 1 to 3).
Japanese Patent Laid-Open No. 8-31725 Japanese Utility Model Publication No. 63-201248 JP-A-1-169150

In each of the above patent documents, when adjacent links are bent, a pair of corresponding pins roll together to move a contact position between opposing side surfaces of the pair of pins. .
In the chain of Patent Document 1, the cross-sectional shape of the side surface of one pin is formed in an involute curve. This involute curve has a smaller radius of curvature as it goes from the outer diameter side to the inner diameter side of the chain, and the radius of curvature of the part in contact with the other pin in the chain linear region where the bending angle between the links is zero Is small. As a result, in the state where the chain extends straight, the contact area between one pin and the other pin is small, and depending on the load condition, a large load may act locally on the contact portion. Also, depending on the use conditions, one pin may easily swing unintentionally with respect to the other pin, and the behavior between the links may be disturbed.

In the chains of Patent Documents 2 and 3, each of the facing surface of one pin and the facing surface of the other pin is formed in an arc shape that is convex. In this case, the pair of pins come into contact with each other at the convex portions, and the contact area between the pins is small, so the same problem as the power transmission chain of Patent Document 1 occurs.
The present invention has been made under such a background, and an object of the present invention is to provide a power transmission chain capable of reducing load bias and further improving durability and a power transmission device including the power transmission chain.

  Another object of the present invention is to provide a power transmission chain that can stabilize the behavior between links in a linear region, and a power transmission device including the power transmission chain.

  In order to achieve the above object, the present invention includes a plurality of links (2, 2E; 2K) and a plurality of connecting members (200) for connecting the plurality of links (2, 2E; 2K) to each other in a bendable manner. The connecting member (200) includes a facing portion (12) opposed to the pair member (4; 2K) formed of either the link (2K) or the member (4) interposed between the link (2, 2E). , 12D) including a predetermined power transmission member (3, 3D, 3F, 3G, 3H, 3J), and the facing portion (12, 12D) is connected to the pair member (4; 2K) with a link (2 , 2E; 2K) is brought into rolling and sliding contact at the contact portions (T, TD; TK) that are displaced by bending between the links (2, 2E; 2K). Change in displacement of the contact portion (T, TD; TK) according to an increase in the bending angle (φ) The rate-of-change decreasing portion (12, 12D) is provided, and the contact portion (T, TD; TK) when the bending angle (φ) is zero is disposed in the rate-of-change decreasing portion (12, 12D). A power transmission chain (1) is provided.

  Here, the following angles can be illustrated as bending angles. That is, when the power transmission chain is viewed from the width direction, a straight line passing between predetermined portions (such as a contact center point of a portion in contact with the pulley) of a pair of power transmission members coupled to one link, and the one link and chain An angle formed by a straight line passing between predetermined portions of a pair of power transmission members connected to another link adjacent in the traveling direction can be exemplified.

In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.
According to the present invention, the rate of change of the displacement amount of the contact portion when the bending angle is near zero can be increased. That is, the radius of curvature of the portion of the facing portion where the contact portion is disposed when the bending angle is near zero can be increased. Thereby, in the power transmission chain in the linear region where the bending angle is zero, a substantially large contact area between the predetermined power transmission member and the mating member can be secured. As a result, the pressure (surface pressure) acting between the predetermined power transmission member and the mating member can be reduced, and it is possible to prevent a high load from acting locally on each of them, thereby improving the durability of the power transmission chain. Can be improved. Further, in the power transmission chain in the linear region, it is possible to prevent the predetermined power transmission member from inadvertently swinging with respect to the pair member, and to prevent inadvertent bending between the links. It is possible to stabilize the behavior between the links in the linear region.

  In the present invention, the facing portion (12, 12D) may be composed of a change rate decreasing portion (12, 12D). In this case, it is possible to reduce the relative motion between the predetermined power transmission member and the pair member when the links adjacent to each other in the chain traveling direction are bent at a predetermined bending angle. Thereby, it can suppress that the said adjacent links are once bent more than a predetermined bending angle (overshoot). Inadvertent movement between links can be suppressed, and noise can be reduced and transmission efficiency can be improved.

In the present invention, the predetermined power transmission member (3, 3D, 3F, 3G, 3H, 3J) is projected onto a projection plane (J) orthogonal to the chain width direction (W), and the chain traveling direction (X) In the projection plane (J) when the direction along the direction x is the x direction and the direction along the direction (V) perpendicular to both the chain travel direction (X) and the chain width direction (W) is the y direction. The trajectory of the projection point of the contact portion (T, TD; TK) may be expressed by the following equation with the projection point of the contact portion (T, TD; TK) in the linear region as the origin (0 _{INV ′} ).

x = −Rbφ0 + Rbsinφ + Rb (φ0−φ) cosφ
y = Rb−Rbcosφ + Rb (φ0−φ) sinφ
However, Rb: Basic circle radius (mm) of the locus of the projected point of the contact portion, φ0: Permissible bending angle between links (maximum design bending angle, rad), φ: Bending angle between links (rad) . In this case, by setting the locus of the projected point of the contact point so as to satisfy the above equation, the change rate decreasing portion can be reliably formed.

  In the present invention, the contact portion (T, TD; TK) when the bending angle (φ) is negative may be disposed in the change rate decreasing portion (12, 12D). Here, the positive bending angle means that another link adjacent to the one link in the forward direction of the chain is bent toward the inner diameter side of the chain with respect to the one link. “Negative” means that another link adjacent to the one link in the forward direction of the chain is bent toward the chain outer diameter side with respect to the one link. When the bending angle is negative, a decrease in the absolute value of the bending angle is called an increase in the bending angle.

In this case, even when the bending angle becomes negative and the links adjacent to each other in the chain traveling direction are reversely warped, these links can behave in the same manner as when the bending angle is positive. It is possible to prevent the behavior between the links from being disturbed.
Further, in the present invention, the predetermined power transmission members (3, 3D, 3F, 3G, 3H, 3J) are each formed in an elongated shape, and a power transmission portion for pulley engagement at each of the pair of end portions (16). (17, 17F, 17H), and randomization for randomizing the engagement cycle when the power transmission units (17, 17F, 17H) are sequentially engaged with the pulleys (60, 70). Means (3, 3D; 2, 2E; 3, 3F; 3, 3G; 3, 3H; 3, 3J) may be provided.

In this case, the frequency of the engagement sound can be distributed over a wide range by randomizing the generation period of the engagement sound when each power transmission member is sequentially engaged with the pulley, and the noise associated with driving the power transmission chain is reduced. can do.
The following can be exemplified as the randomizing means. That is, providing a plurality of types of power transmission members having different trajectories of rolling and sliding contact of the contact portion, and providing a plurality of types of links having different pitches (connection pitches) between adjacent power transmission members in the chain linear region. , Rukoto to place the different plurality of types of power transmission member of the relative position between the contact center points for the sheave surface of the contact portion and the pulley when viewed straight region of the chain from the chain widthwise direction at random, the pair against the sheave surface Rukoto to place the different plurality of types of power transmission members of the distance between the contact center points of the end surface at random, different plural kinds of inclination (angle of attack) of the power transmission member when viewed chain linear region from the chain width direction Rukoto be placed randomly, and stiffness Rukoto to place the different plurality of types of power transmission members (elastic modulus) at random, at least 1 It can be exemplified.

  In the present invention, the first and second pulleys (60, 70) each having a pair of conical sheave surfaces (62a, 63a, 72a, 73a) facing each other and the pulleys are wound around these pulleys. In some cases, the power transmission chain (1) that contacts the sheave surfaces (62a, 63a, 72a, 73a) and transmits power is provided. In this case, a power transmission device with excellent durability can be realized.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 schematically shows a main configuration of a chain-type continuously variable transmission (hereinafter also simply referred to as a continuously variable transmission) as a power transmission device including a power transmission chain according to an embodiment of the present invention. It is a perspective view. Referring to FIG. 1, a continuously variable transmission 100 is mounted on a vehicle such as an automobile, and includes a drive pulley 60 made of metal (such as structural steel) as a first pulley, and a second pulley. And a driven pulley 70 made of metal (such as structural steel) and an endless power transmission chain 1 (hereinafter also simply referred to as a chain) wound between the pulleys 60 and 70. . In addition, the chain 1 in FIG. 1 has shown a partial cross section for easy understanding.

  FIG. 2 is a partially enlarged sectional view of the drive pulley 60 (driven pulley 70) and the chain 1 of FIG. Referring to FIGS. 1 and 2, drive pulley 60 is attached to input shaft 61 connected to a vehicle drive source so as to be capable of transmitting power, and includes fixed sheave 62 and movable sheave 63. Yes. The fixed sheave 62 and the movable sheave 63 have a pair of sheave surfaces 62a and 63a that face each other. Each sheave surface 62a, 63a includes a conical inclined surface. A groove is defined between the sheave surfaces 62a and 63a, and the chain 1 is held between the grooves 1 with a strong pressure.

  Further, a hydraulic actuator (not shown) for changing the groove width is connected to the movable sheave 63, and the movable sheave 63 is moved in the axial direction of the input shaft 61 (left-right direction in FIG. 2) at the time of shifting. By doing so, the groove width is changed. Thereby, the chain 1 is moved in the radial direction of the input shaft 61 (vertical direction in FIG. 2), and the effective radius R (hereinafter also referred to as the effective radius R of the pulley 60) of the pulley 60 is set to the minimum value R1. (See FIG. 3A. For example, 30 mm.) To a maximum value R2 (see FIG. 3B, for example, 70 mm.) Can be changed.

On the other hand, as shown in FIGS. 1 and 2, the driven pulley 70 is attached to an output shaft 71 that is connected to a drive wheel (not shown) so as to be capable of transmitting power and is integrally rotatable. A fixed sheave 73 and a movable sheave 72 each having a pair of opposed sheave surfaces 73a and 72a for forming a groove for sandwiching the chain 1 with high pressure are provided.
A hydraulic actuator (not shown) is connected to the movable sheave 72 of the driven pulley 70 in the same manner as the movable sheave 63 of the drive pulley 60, and the groove width is changed by moving the movable sheave 72 during shifting. It is like that. Accordingly, the chain 1 is moved, and the effective radius R of the pulley 70 related to the chain 1 (hereinafter also referred to as the effective radius R of the pulley 70) is changed from the maximum value R2 (see FIG. 3A) to the minimum value R1 (see FIG. 3). 3 (see (B)).

With the above configuration, when the continuously variable transmission 100 has the highest reduction ratio (under drive), the effective radius R of the drive pulley 60 is set to the minimum value R1, as shown in FIG. The effective radius R of the pulley 70 is set to the maximum value R2.
On the other hand, when the speed increasing ratio of the continuously variable transmission 100 is the highest (during overdrive), the effective radius R of the drive pulley 60 is set to the maximum value R2, as shown in FIG. The effective radius R is set to the minimum value R1.

FIG. 4 is a cross-sectional view of the main part of the chain 1. FIG. 5 is a cross-sectional view taken along the line VV in FIG. 4 and shows the chain 1 in a straight region. FIG. 6 is a side view of the chain 1 in the bent region.
In the following, when described with reference to FIG. 5, the description will be based on the chain 1 in the linear region as viewed from the chain width direction, and when described with reference to FIG. 6, as viewed from the chain width direction. The description will be made with reference to the chain 1 in the bent region.

Referring to FIGS. 4 and 5, chain 1 includes a plurality of links 2 and a plurality of connecting members 200 that connect these links 2 so that they can be bent.
Hereinafter, the direction along the traveling direction of the chain 1 is referred to as a chain traveling direction X, and the direction perpendicular to the chain traveling direction X and along the longitudinal direction of the connecting member 200 is referred to as a chain width direction W. A direction orthogonal to both the width directions W is referred to as an orthogonal direction V.

Each link 2 is formed in a plate shape, and is disposed between a front end portion 5 and a rear end portion 6 as a pair of end portions arranged in the front and rear in the chain traveling direction X, and between the front end portion 5 and the rear end portion 6. An intermediate portion 7 is included.
The front end portion 5 and the rear end portion 6 are respectively formed with a front through hole 9 as a first through hole and a rear through hole 10 as a second through hole. The intermediate portion 7 has a column portion 8 that partitions the front through hole 9 and the rear through hole 10. The column portion 8 has a predetermined thickness in the chain traveling direction X. Moreover, the peripheral part in each link 2 is formed in the smooth curve, and is made into the shape which a stress concentration does not produce easily.

  First to third link rows 51 to 53 are formed using the link 2. Specifically, each of the first link row 51, the second link row 52, and the third link row 53 includes a plurality of links 2 arranged in the chain width direction W. In each of the first to third link rows 51 to 53, the links 2 in the same link row are aligned so that the positions in the chain traveling direction X are the same. The first to third link rows 51 to 53 are arranged side by side along the chain traveling direction X.

The links 2 of the first to third link rows 51 to 53 can be rotated relative to the links 2 of the corresponding first to third link rows 51 to 53 using the corresponding connecting members 200 (bendable). It is connected to.
Specifically, the front through-hole 9 of the link 2 of the first link row 51 and the rear through-hole 10 of the link 2 of the second link row 52 correspond to each other side by side in the chain width direction W. The links 2 of the first and second link rows 51 and 52 are connected to each other so as to be bent in the chain traveling direction X by the connecting member 200 inserted through the through holes 9 and 10.

Similarly, the front through-hole 9 of the link 2 of the second link row 52 and the rear through-hole 10 of the link 2 of the third link row 53 correspond to each other along the chain width direction W. The links 2 of the second and third link rows 52 and 53 are connected to each other so as to be bent in the chain traveling direction X by the connecting member 200 that is inserted through the through holes 9 and 10.
In FIG. 4, only one each of the first to third link rows 51 to 53 is illustrated, but the first to third link rows 51 to 53 are repeated along the chain traveling direction X. Has been. Then, the links 2 in the two link rows adjacent to each other in the chain traveling direction X are sequentially connected by the corresponding connecting members 200 to form an endless chain 1.

Each connecting member 200 includes a pair of first and second pins 3 and 4. The paired first and second pins 3 and 4 are configured to be in rolling contact with each other. The rolling sliding contact means a contact including at least one of a rolling contact and a sliding contact.
With reference to FIGS. 4 and 5, the first pin 3 is a long (plate-shaped) predetermined power transmission member extending in the chain width direction W. The peripheral surface 11 of the first pin 3 extends in parallel to the chain width direction W.

The peripheral surface 11 has a front part 12 as an opposing part facing forward in the chain traveling direction X and a rear part 13 as a back part facing backward in the chain traveling direction X.
The front portion 12 is formed in a curve having a smooth cross-sectional shape, and faces the paired second pins 4 and is in rolling contact with the contact portion T (contact line). The front part 12 can be said to be a part that can come into contact with the paired second pins 4 of the first pins 3. The contact portion T1 in the chain 1 in the straight region is disposed closer to the inner diameter side of the chain in the front portion 12.

The rear portion 13 is formed on a flat surface. This flat surface has a predetermined inclination angle B with respect to a predetermined plane A1 orthogonal to the chain traveling direction X (a plane orthogonal to the paper surface in FIG. 5), and faces the inner diameter side of the chain.
The pair of end portions 16 in the longitudinal direction (chain width direction W) of the first pin 3 protrudes in the chain width direction W from the links 2 arranged at the pair of end portions in the chain width direction W, respectively. The pair of end portions 16 are respectively provided with end surfaces 17 as a pair of power transmission portions.

2 and 6, the pair of end faces 17 are opposed to each other across a plane A2 orthogonal to the chain width direction W, and have symmetrical shapes. These end surfaces 17 are for frictional contact (engagement) with the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70.
The first pin 3 is sandwiched between the corresponding sheave surfaces 62a, 63a, 72a, 73a, whereby power is transmitted between the first pin 3 and the pulleys 60, 70. Since the end surface 17 of the first pin 3 directly contributes to power transmission, the first pin 3 is formed of a high-strength wear-resistant material such as bearing steel (SUJ2), for example.

The end surface 17 of the first pin 3 is formed in a shape including a part of a spherical surface, is convexly curved outward in the chain width direction W, and faces the inner diameter side of the chain. When viewed from the chain width direction W, the position of the top 23 of the end face 17 coincides with the position of the centroid of the end face 17.
The end surface 17 comes into contact with the pulleys 60 and 70 at the contact region 24. The contact region 24 has, for example, an elliptical shape, and has a contact center point C (corresponding to the centroid of the contact region 24). When viewed from the chain width direction W, the position of the contact center point C coincides with the position of the centroid (the top portion 23) of the end surface 17.

Here, the effective radius R of each of the pulleys 60 and 70 described above is defined as follows. That is, the effective radius R of the drive pulley 60 is the diameter of the pulley 60 between the contact center point C of the power transmission surface 17 of the first pin 3 clamped by the drive pulley 60 and the center axis F1 of the drive pulley 60. Defined as direction distance.
Similarly, the effective radius R of the driven pulley 70 is such that the pulley 70 between the contact center point C of the power transmission surface 17 of the first pin 3 sandwiched by the driven pulley 70 and the central axis F2 of the driven pulley 70. Defined as radial distance.

When viewed from the chain width direction W, the major axis D of the contact region 24 has a predetermined angle of attack E (for example, 5 to 12 °, 10 ° in the present embodiment) with respect to the plane A1. The chain advances in the chain traveling direction X side from the chain outer diameter side toward the inner diameter side.
The angle of attack E is, for example, equal to the inclination angle B of the rear portion 13 of the first pin 3 (E = B). Note that E ≠ B may be used.

4 and 5, the second pin 4 (also referred to as a strip or an interpiece) is a long member that is formed of the same material as that of the first pin 3 and extends in the chain width direction W. There is a pair member that is interposed between the paired first pin 3 and the corresponding link 2.
The second pin 4 is formed to be shorter than the first pin 3 so as not to contact the sheave surface of each pulley. The second pin 4 is forward of the pair of first pins 3 in the chain traveling direction X. Is arranged. With respect to the chain traveling direction X, the second pin 4 is formed thinner than the first pin 3.

The peripheral surface 18 of the second pin 4 extends in the chain width direction W. The peripheral surface 18 has a rear portion 19 as a facing portion facing rearward in the chain traveling direction X.
The rear portion 19 is formed on a flat surface orthogonal to the chain traveling direction X. The rear portion 19 faces the front portion 12 of the paired first pin 3 and is in rolling contact with the front portion 12 at the contact portion T.

The locus of the contact portion T with the first pin 3 and the second pin 4 paired with the first pin 3 as viewed from the chain width direction W is a predetermined curve INV ′ to be described later. .
The chain 1 is a so-called press-fit type chain. Specifically, the first pin 3 is loosely fitted in the front through hole 9 of each link 2 so as to be relatively movable, and the relative movement is regulated by the rear through hole 10 of each link 2. The second pin 4 is press-fitted and press-fitted so that the relative movement of the second pin 4 is restricted to the front through-hole 9 of each link 2 and can be relatively moved to the rear through-hole 10 of each link 2. Are loosely fitted.

  In other words, the first pin 3 is loosely fitted in the front through hole 9 of each link 2 so as to be relatively movable, and the second pin 4 paired with the first pin 3 is relatively moved. The first pin 3 is press-fitted and fitted in the rear through hole 10 of each link 2 so that relative movement is restricted, and the first pin A second pin 4 paired with 3 is loosely fitted so as to be relatively movable.

With the above configuration, the front portion 12 of the first pin 3 is displaced with respect to the rear portion 19 of the paired second pin 4 as the link 2 adjacent to the chain traveling direction X is bent. Rolling and sliding contact on T.
The chain 1 has a predetermined connection pitch P. The connection pitch P refers to the distance between the contact center points C of the first pins 3 adjacent to each other in the chain traveling direction X when the chain 1 is viewed from the chain width direction W. In the present embodiment, the connection pitch P is set to 8 mm, for example.

Referring to FIG. 6, in the chain 1 in the bending region, the links 2 adjacent to each other in the chain traveling direction X are bent at a predetermined bending angle φ. The bending angle φ is defined as an angle formed by the first plane H1 and the second plane H2.
The first plane H1 includes the respective contact center points C of the pair of first pins 3a and 3b inserted into the respective through holes 9 and 10 of the link 2a in one of the bent regions, and the chain width. A plane parallel to the direction W.

The second plane H2 is the contact center of each of the pair of first pins 3b and 3c inserted into the through holes 9 and 10 of the other link 2b adjacent to the link 2a and the chain traveling direction X. A plane including the point C and parallel to the chain width direction W is referred to.
As shown in FIG. 6, when viewed from the chain width direction W, another link 2b adjacent to the one link 2a in front of the chain traveling direction X is bent toward the inner diameter side of the chain with respect to the one link 2a. The bending angle φ is a positive value. When the bending angle φ is positive, “the bending angle φ increases” means that the value of the bending angle φ increases.

On the other hand, when viewed from the chain width direction W, when the other link 2b adjacent to the one link 2a in front of the chain traveling direction X is bent toward the outer diameter side of the one link 2a, The bending angle φ is a negative value. When the bending angle φ is negative, “the bending angle φ increases” means that the absolute value of the bending angle φ decreases.
The range of the design bending angle φ is set to, for example, −3 ° to 20 °. The allowable bending angle φ0 (the maximum design positive bending angle φ) is 20 °.

With reference to FIGS. 5 and 6, the feature of the present embodiment is that the front portion 12 of the first pin 3 has a rate of change of the displacement amount of the contact portion T as the bending angle φ increases. The rate of change is reduced, and the contact portion T when the bending angle φ is zero (φ = 0) is arranged in the rate of change reduction portion.
In the present embodiment, the front portion 12 includes a change rate decreasing portion, and the cross-sectional shape of the front portion 12 includes a predetermined curve INV ′ described later. As for the front part 12, the curvature radius in the part in which the contact part T is arrange | positioned becomes small according to the increase in bending angle (phi). The front portion 12 includes a first portion 21 and a second portion 22.

  The first portion 21 extends from the front portion 12 of the first pin 3 to the chain outer diameter side from the contact portion T1 in the linear region, and the first portion 21 has a bending angle φ of zero or The contact portion T when positive (φ ≧ 0) is arranged. The second portion 22 of the front portion 12 of the first pin 3 extends closer to the inner diameter side of the chain than the contact portion T1 in the linear region. The second portion 22 has a negative bending angle φ ( The contact portion T when φ <0) is arranged.

FIG. 7 is a diagram in which the first portion 21 of the front portion 12 of the first pin 3 is projected onto a projection plane J orthogonal to the chain width direction W. FIG. 8 is a view for explaining the first portion 21 of the front portion 12 of the first pin 3.
Referring to FIGS. 5, 7, and 8, first pin 3 is projected onto projection plane J, the direction along chain traveling direction X is the x direction, and among the directions along orthogonal direction V, the chain When the direction from the inner diameter side to the outer diameter side is the y direction, the locus of the projection point of the contact portion T in the projection plane J is the origin 0 _{INV ′} of the projection point of the contact portion T1 in the linear region of the chain 1. The following formulas (1) and (2) are satisfied.

x = −Rbφ0 + Rbsinφ + Rb (φ0−φ) cosφ (1)
y = Rb−Rbcosφ + Rb (φ0−φ) sinφ (2)
However, Rb: radius (mm) of the basic circle K _{INV ′} of the locus of the projection point of the contact portion T, φ0: allowable bending angle (rad), φ: bending angle (rad).
The cross-sectional shape of the first portion 21 of the front portion 12 is a shape along the locus of the projection point of the contact portion T (the shape of a predetermined curve INV ′ described later).

Referring to FIG. 8, the basic circle K _{INV ′} is a circle having a center P0 _{INV ′} on the projection plane J. The center P0 _{INV ′} is positioned closer to the chain outer diameter side than the contact portion T, and the position relative to the origin 0 _{INV ′} is (x, y) = (− Rbφ0, Rb).
In the present embodiment, for example, the basic circle radius Rb = 70 (mm) and the allowable bending angle φ0 = 20 (deg) ≈0.35 (rad). The basic circle radius Rb may be smaller than 70 or larger than 70. Similarly, the allowable bending angle φ0 may be smaller than 20 or larger than 20. What is necessary is just to set suitably according to the use condition of the chain 1. FIG.

In FIG. 7, a black dot on the projection plane J of the first portion 21 of the front portion 12 indicates the position of the contact portion T at every bending angle of 2 °. It can be seen that as the bending angle φ increases, the interval between adjacent black circle points becomes narrower, and the rate of change (moving speed) of the displacement amount of the contact portion T decreases as the bending angle φ increases.
FIG. 9 is a view for explaining the cross-sectional shape of the first portion 21 of the front portion 12. 8 and 9, the cross-sectional shape of the first portion 21 of the front portion 12 is a shape of a predetermined curve INV ′ (inverse involute curve) related to the involute curve INV.

Specifically, the involute curve INV has a basic circle K _INV similar to the basic circle K _{INV ′} . The origin 0 _INV of the involute curve INV is on the basic circle K _INV . The end point of the involute curve INV is P2 _INV . The point P2 _INV includes a straight G1 _INV through and origin 0 _INV inclined by acceptable bending angle φ0 respect to a straight line G0 _INV through both the center P0 _INV and the origin 0 _INV of the base circle K _INV, the base circle K _INV The tangent line G2 _{INV at} the intersection P1 _INV with the point intersects the involute curve INV.

The involute curve INV, and such tangent G2 _INV, as shown in FIG. 10, the center P0 _INV around the base circle K _INV rotated by acceptable bending angle .phi.0, further the involute curve INV of this time the tangential G2 _INV Reverse (rotate 180 °) around a parallel straight line G3 _INV . Thereby, the involute curve INV coincides with the predetermined curve INV ′ (inverse involute curve) shown in FIG.

Referring to FIG. 9, the involute curve INV is a curve drawn by the tip (one end) of the yarn M _INV when the yarn M _INV wound around the basic circle K _INV is unwound. The involute curve INV can be expressed by a mathematical formula.
Specifically, one of the tangential directions of the basic circle K _{INV at} the origin 0 _INV is the x direction, and the direction from the inner diameter side to the outer diameter side of the basic circle K _INV among the directions along the straight line G0 _INV is the y direction. and then, 'when _INV, the point P1' to the point of contact with the yarn M _INV and basic circle K _INV when unraveled yarn M _INV only from the base circle K _INV Rbφ P1 coordinates of _INV,
P1 ′ _INV (x, y) = (− Rbsinφ, Rbcosφ−Rb) (3)
It becomes.

The distance between the point P1 _{INV 'INV} and yarn M tip point P2 of the _INV' in this case is equal to the distance Rbfai between the point P1 _'INV and the origin 0 _INV, the Rbfai. Therefore, the distance between the point P1 ′ _INV and the point P2 ′ _INV is Rbφcosφ with respect to the x direction and Rbφsinφ with respect to the y direction. That is,
Between P1 ′ _{INV and} P2 ′ _INV (Δx, Δy)
= (Rbφcosφ, Rbφsinφ) (4)
It is.

Therefore, when the values in the x direction of (x, y) in the above equation (3) and (Δx, Δy) in the equation (4) are added and the values in the y direction are added, the following equation (5) , (6), the mathematical expression of the coordinates of the point P2 ′ _INV , that is, the mathematical expression of the involute curve INV is obtained.
x = −Rbsinφ + Rbφcosφ (5)
y = Rbcosφ−Rb + Rbφsinφ (6)
Referring to FIG. 8, a predetermined curve INV 'is thread M _INV' is a curve the tip of the draw _'the yarn M _INV when wound _in' the base circle K _INV. Specifically, _'together with overlaid, the intersection P1 _{INV' 'the} base circle K _INV' yarn _INV predetermined intersection P1 _INV intersection yarn M _{INV 'along'} tangent G2 _{INV 'of} the base circle K _INV in P1 _'from the state extended by a length Rbφ from the yarn M _{INV' INV} is a curve point P2 _'INV' draws the other end (tip) of the _'yarn M _INV when _wound' to the base circle K _INV.

The predetermined curve INV ′ can be expressed by the equations (1) and (2) as described above, and these equations (1) and (2) are obtained as follows.
That is, first, the origin 0 _{INV 'is} tangent G2 _INV' matches the point P2 _'INV' tip _'of yarns M _INV when extending _the' thread M _INV along. And the coordinates of the center P0 _{INV '} of the basic circle K _INV' are
P0 _{INV ′} (x, y) = (− Rbφ0, Rb)
It becomes. The x component corresponds to the first term of the above formula (1), and the y component corresponds to the first term of the above formula (2).

Then, when wound by a length Rbφ the _'basic circle K _{INV a'} yarn M _INV, yarn M _{INV 'and} the base circle K _INV' each other with the intersection point P1 _'INV', the center P0 _{INV 'and} a The distance between is Rbsinφ with respect to the x direction and −Rbcosφ with respect to the y direction. That is,
Between P0 _{INV ′ and} P1 ′ _{INV ′} (Δx, Δy) = (Rbsinφ, −Rbcosφ)
It is. This Δx corresponds to the second term of the above formula (1), and Δy corresponds to the second term of the above formula (2).

Furthermore, the distance between the intersection P1 _'tip point of P2'_'INV' and yarn M _{INV INV 'when} the intersection P1' _{INV ''} base circle K _INV and _{'yarn INV} at intersect is, x Rb (φ0−φ) cosφ with respect to the direction and Rb (φ0−φ) sinφ with respect to the y direction. That is,
Between P1 ′ _{INV ′ and} P2 ′ _{INV ′} (Δx, Δy) = (Rb (φ0−φ) cosφ, Rb (φ0−φ) sinφ)
It is. This Δx corresponds to the third term of the above equation (1), and Δy corresponds to the third term of the above equation (2).

From the above, the above formulas (1) and (2) become the formula of the coordinates of the point P2 ′ _{INV ′} , that is, the formula of the predetermined curve INV ′.
Referring to FIG. 5, the second portion 22 of the front portion 12 has a curved shape that is smoothly connected to the first portion 21. The cross-sectional shape of the second portion 22 is a curve that satisfies the above formulas (1) and (2). The cross-sectional shape of the second portion 22 may be a curve having a single radius of curvature. Moreover, the connection part of the 1st and 2nd parts 21 and 22 does not need to be made smooth.

In the continuously variable transmission having the above schematic configuration, when the chain 1 moves from the straight region to the bent region, the position of the contact portion T is on the first portion 21 of the front portion 12 as shown in FIG. Displaces toward the chain outer diameter side. The moving speed of the contact portion T at this time can be obtained by differentiating the component in the x direction by the bending angle φ and the component in the y direction by the bending angle φ. Obtained by differentiating. That is,
x ′ = Rbcosφ−Rbφ0sinφ−Rbcosφ + Rbφsinφ
= -Rb (φ0-φ) sinφ (7)
y ′ = Rbsinφ + Rbφ0 cosφ−Rbsinφ−Rbφcosφ
= Rb (φ0−φ) cosφ (8)
Accordingly, the moving speed v of the contact portion T can be obtained by averaging the above formulas (7) and (8). That is,

  Since the bending angle φ in the linear region is zero (φ = 0), the movement distance L ′ of the contact portion T on the front portion 12 during the period from the bending angle φ to the positive bending angle φ. (Φ) is obtained by the following equation.

From the above L ′ (φ), the rate of change of the displacement amount of the contact portion T decreases as the bending angle φ increases.
As described above, according to the present embodiment, the front portion 12 of the first pin 3 is the change rate decreasing portion, and the change rate of the displacement amount of the contact portion T is predetermined as the bending angle φ increases. To decrease at a rate of.
As a result, the rate of change of the displacement amount of the contact portion T in the linear region where the bending angle φ is near zero can be increased. That is, the radius of curvature of the first portion 21 where the contact portion T is disposed when the bending angle φ is near zero in the front portion 12 of the first pin 3 can be increased. Thereby, in the chain 1 in the linear region where the bending angle φ is zero, a substantially large contact area between the first pin 3 and the second pin 4 can be secured.

  As a result, the pressure (surface pressure) acting between the first pin 3 and the second pin 4 can be reduced, and a high load can be prevented from acting locally on each of the two. Durability can be improved. Further, in the chain 1 in the straight region, the first pin 3 can be prevented from inadvertently swinging with respect to the second pin 4, and the inadvertent bending between the links 2 can be prevented. The behavior between the links 2 in the linear region can be stabilized.

  In addition, the entire area of the front portion 12 of the first pin 3 is a change rate decreasing portion. As a result, the relative movement between the first pin 3 and the second pin 4 when the links 2 adjacent in the chain traveling direction X are bent at a predetermined bending angle φ can be reduced. Thereby, irrespective of the bending angle φ, it is possible to suppress the adjacent links 2 from being once bent (overshooted) more than a predetermined bending angle φ. Inadvertent movement between the links 2 can be suppressed, and noise can be reduced and transmission efficiency can be improved.

Further, since the locus of the projection point of the contact portion T in the projection plane J satisfies the above formulas (1) and (2), a change rate decreasing portion is present at the front portion 12 of the first pin 3. Can be reliably formed.
Further, the contact portion T when the bending angle φ is negative is arranged in the second portion 22 formed of the change rate decreasing portion. Thereby, even when the bending angle φ becomes negative and the links 2 adjacent to each other in the chain traveling direction X are reversely warped, the links 2 are caused to behave in the same manner as when the bending angle φ is positive. It is possible to prevent the behavior between the links 2 from being disturbed.

Furthermore, by providing the first pin 3 with the angle of attack E, the arrangement of the first pin 3 can be optimized and the engagement with the pulleys 60 and 70 can be made smoother.
Further, the first pin 3 is loosely fitted into the front through hole 9 of each link 2 and press-fitted into the rear through hole 10 of each link 2, and the second pin 4 is fitted to the front through hole 9 of each link 2. The links 2 are press-fitted and loosely fitted into the rear through holes 10 of the links 2.

Thereby, when each end surface 17 of each first pin 3 comes into contact with the corresponding sheave surface 62a, 63a, 72a, 73a of each pulley 60, 70, the second pin 4 that makes a pair has the first The links 2 can be bent by rolling and sliding contact with the pins 3.
At this time, between the first and second pins 3 and 4 that make a pair, the rolling contact component is large and the sliding contact component is very small. As a result, each end face 17 of each first pin 3 is The corresponding sheave surfaces 62a, 63a, 72a, and 73a come into contact with little rotation, so that friction loss can be reduced and higher transmission efficiency can be ensured.

Further, as described above, the rate of change of the displacement amount of the contact portion T due to the bending between the links 2 is the largest at zero when the bending angle φ is positive. Therefore, when the effective radius R of each pulley 60, 70 is large and the bending angle φ in the bending region is a small value close to zero, the contact portion T when the chain 1 moves from the linear region to the bending region. A large amount of movement can be secured.
That is, the amount of movement of the contact center point C of the first pin 3 when the chain 1 moves from the straight region to the bent region can be increased. As a result, when the first pin 3 engages with each of the pulleys 60 and 70, the relative speed between the two can be reduced to smoothly engage the first pin 3, and the first pin 3 and each of the pulleys 60 and 70 are shocked. Can be prevented. Noise can be further reduced, and loss can be reduced to further improve transmission efficiency.

Thus, the continuously variable transmission 100 excellent in durability, silence, and transmission efficiency can be realized.
FIG. 11 is a partial cross-sectional view of an essential part of another embodiment of the present invention. In the present embodiment, differences from the embodiment shown in FIGS. 1 to 10 will be mainly described, and the same components are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIG. 10, the feature of this embodiment is that the randomizing means for randomizing the engagement period when the end face of each first pin is sequentially engaged with each pulley. As described above, a plurality of types of first pins having different trajectories of rolling and sliding contact of the contact portion are provided.
Specifically, first pins 3 and 3D are provided as a plurality of types of first pins.

The cross-sectional shape of the front portion 12D of the first pin 3D is different from the cross-sectional shape of the front portion 12 of the first pin 3. For example, the basic circle radius of the curve of the predetermined curve INV′D in the cross section of the front portion 12D is different from the basic circle radius of the predetermined curve INV ′ of the cross section of the front portion 12 of the first pin 3. .
With the configuration described above, the locus of the rolling sliding contact of the contact portion T of the first pin 3 with respect to the first pin 3 and the contact of the first pin 3D with respect to the first pin 3D. The locus of the rolling and sliding contact of the part TD is different.

  The first pins 3 and the first pins 3D are randomly arranged in the chain traveling direction X. In this case, “randomly arranged” means that at least one of the first pins 3 and the first pins 3D is irregularly arranged in at least a part of the chain traveling direction X. It is. Note that “irregular” means that there is no periodicity and / or regularity.

According to the present embodiment, the frequency of the engagement sound can be distributed over a wide range by randomizing the generation period of the engagement sound when the first pins 3 and 3D are sequentially engaged with the pulleys. Noise during driving can be further reduced.
FIG. 12 is a partial cross-sectional view of a main part of still another embodiment of the present invention. In the present embodiment, differences from the embodiment shown in FIGS. 1 to 10 will be mainly described, and the same components are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIG. 12, the feature of this embodiment is that the randomizing means for randomizing the engagement period when the end surfaces of the first pins are sequentially engaged with the pulleys. As described above, a plurality of types of links having different connection pitches are provided in the straight line region.
Specifically, as a plurality of types of links, a link 2 as a link having a relatively long connection pitch and a link 2E as a link having a relatively short connection pitch are provided.

In the link 2E, the thickness of the column portion 8E in the chain traveling direction X is made thinner than the thickness of the column portion 8 of the link 2 in the chain traveling direction X. Thereby, the connection pitch PE of the link 2E is shorter than the connection pitch P of the link 2 (PE <P).
The link 2 and the link 2E (the link row including the link 2 and the link row including the link 2E) are randomly arranged in the chain traveling direction X. Note that “randomly arranged” in this case means that at least one of the link 2 and the link 2E is irregularly arranged in at least a part of the chain traveling direction X.

FIG. 13 is a side view of the main part of still another embodiment of the present invention. In the present embodiment, differences from the embodiment shown in FIGS. 1 to 10 will be mainly described, and the same components are denoted by the same reference numerals and description thereof will be omitted.
Referring to FIG. 13, the feature of this embodiment is that the randomizing means for randomizing the engagement period when the end face of each first pin is sequentially engaged with each pulley. As described above, a plurality of types of first pins having different relative positions between the contact portion and the contact center point in the straight line region when viewed from the chain width direction W are provided.

Specifically, first pins 3 and 3F are provided as a plurality of types of first pins.
When viewed from the chain width direction W, the first pin 3 in the linear region has a relative position between the contact portion T1 and the contact center point C that is separated by Δx1 with respect to the chain traveling direction X and is orthogonal V is separated by Δy1.
On the other hand, when viewed from the chain width direction W, the first pin 3F in the linear region has a relative position between the contact portion TF1 and the contact center point CF separated by Δx2 with respect to the chain traveling direction X. With respect to the orthogonal direction V, they are separated by Δy2.

That is, in the linear region of the chain viewed from the chain width direction W, the relative position of the contact center point C with respect to the contact portion T1 of the first pin 3 and the relative position of the contact center point CF with respect to the contact portion TF1 of the first pin 3F. Is different in at least one of the chain traveling direction X and the orthogonal direction V (both in the present embodiment).
The first pins 3 and the first pins 3F are randomly arranged in the chain traveling direction X. In this case, “randomly arranged” means that at least one of the first pins 3 and the first pins 3F is irregularly arranged in at least a part of the chain traveling direction X. It is.

FIG. 14 is a view for explaining still another embodiment of the present invention, and FIGS. 14A and 14B are cross-sectional views of the first pin as viewed from the chain traveling direction X, respectively. is there.
In the present embodiment, differences from the embodiment shown in FIGS. 1 to 10 will be mainly described, and the same components are denoted by the same reference numerals and description thereof will be omitted.
Referring to FIGS. 14A and 14B, the feature of this embodiment is that the engagement period when the end surfaces of the first pins are sequentially engaged with the pulleys. As a randomizing means for randomizing, a plurality of types of first pins having different distances between the contact center points of the pair of end faces are provided.

Specifically, first pins 3 and 3G are provided as a plurality of types of first pins. The distance NG between the contact center points C of the pair of end faces 17 of the first pin 3G in the chain width direction W is shorter than the distance N between the contact center points C of the pair of end faces 17 of the first pin 3 ( NG <N).
The first pins 3 and the first pins 3G are randomly arranged in the chain traveling direction X. In this case, “randomly arranged” means that at least one of the first pins 3 and the first pins 3G is irregularly arranged in at least a part of the chain traveling direction X. It is.

FIG. 15 is a side view of the main part of still another embodiment of the present invention. In the present embodiment, differences from the embodiment shown in FIGS. 1 to 10 will be mainly described, and the same components are denoted by the same reference numerals and description thereof will be omitted.
Referring to FIG. 15, the feature of this embodiment is that the randomizing means for randomizing the engagement period when the end surfaces of the first pins are sequentially engaged with the pulleys. As described above, a plurality of types of first pins having different angles of attack (tilts) in the chain linear region are provided.

Specifically, as a plurality of types of first pins, the first pin 3 as a small angle of attack pin with a relatively small angle of attack and the first pin as a large angle of attack pin with a relatively large angle of attack Pin 3H is provided.
The angle of attack E of the first pin 3 and the angle of attack EH of the first pin 3H are different from each other, and the angle of attack E of the first pin 3 is smaller than the angle of attack EH of the first pin 3H. (E <EH).

Further, the first pins 3 and the first pins 3H are randomly arranged in the chain traveling direction X. In this case, “randomly arranged” means that at least one of the first pins 3 and the first pins 3H is irregularly arranged in at least a part of the chain traveling direction X. .
FIG. 16 is a view for explaining still another embodiment of the present invention, and FIGS. 16 (A) and 16 (B) are side views of the first pin seen from the chain traveling direction X, respectively. is there. In the present embodiment, differences from the embodiment shown in FIGS. 1 to 10 will be mainly described, and the same components are denoted by the same reference numerals and description thereof will be omitted.

Referring to FIGS. 16A and 16B, the feature of this embodiment is that the engagement period when the end surfaces of the first pins are sequentially engaged with the pulleys. As a randomizing means for randomizing, a plurality of types of first pins having different rigidity (elastic modulus) are provided.
Specifically, a first pin 3 as a high-rigidity pin having relatively high rigidity and a first pin 3J as a low-rigidity pin having relatively low rigidity are provided as the first pins. .

The first pin 3 is formed of, for example, JIS standard SUJ2 (high carbon chromium bearing steel) as described above, and the first pin 3J is formed of, for example, SUS440C (martensitic stainless steel). ing.
The first pins 3 and the first pins 3J are randomly arranged in the chain traveling direction X. The “random arrangement” in this case means that at least one of the first pins 3 and the first pins 3J is irregularly arranged in at least a part of the chain traveling direction X. It is.

With the above configuration, when the chain 1 is tensioned, the amount of bending of the first pin 3 and the first pin 3J is different. As a result, each of the first pins 3 and 3J is sequentially turned on. The period when it is bitten by the pulley becomes random.
FIG. 17 is a partial sectional view of an essential part of still another embodiment of the present invention. In the present embodiment, differences from the embodiment shown in FIGS. 1 to 10 will be mainly described, and the same components are denoted by the same reference numerals and description thereof will be omitted.

  Referring to FIG. 17, the feature of the present embodiment is that one first pin 3 connects links 2K adjacent in the chain traveling direction X so that they can rotate relative to each other (bendable). There is in point. Specifically, the corresponding first pin 3 is loosely fitted in the front through hole 9K of each link 2K so as to be relatively movable, and the corresponding first pin 3 is relative to the rear through hole 10K of each link 2K. It is press-fitted so that movement is restricted.

  A front portion 31 (opposing portion) of the peripheral portion 30 of the front through hole 9K in the chain traveling direction X has a cross-sectional shape extending in the orthogonal direction V. The front portion 31 faces the front portion 12 of the first pin 3 that is loosely fitted in the front through hole 9K, and is in rolling contact with the contact portion TK. As a result, the link 2K as the pair member and the first pin 3 loosely fitted to the link 2K are in rolling contact with each other as the link 2K is bent.

According to the present embodiment, the pitch between the first pins 3 can be shortened to increase the number of first pins 3 that are bitten by each pulley at a time. Thereby, the load per 1st pin 3 can be reduced, the collision force with each pulley can be reduced, and noise can be reduced more.
In the present embodiment, a randomizing means for randomizing the engagement period with the pulley may be provided.

While several embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments.
For example, in the embodiment shown in FIG. 11, three or more types of first pins having different trajectories of rolling and sliding contact of the contact portion may be provided.
Furthermore, in the embodiment shown in FIG. 12, three or more types of links having different connection pitches may be provided.

  Further, in the embodiment shown in FIG. 13, a plurality of types of first pins whose relative positions between the contact portion and the contact center point when the linear region of the chain is viewed from the chain width direction W are different only in the orthogonal direction V. May be included. Similarly, the relative position between the contact portion and the contact center point when the linear region of the chain is viewed from the chain width direction W includes a plurality of types of first pins that differ only in the direction along the chain traveling direction X. Also good.

Further, three or more types of first pins having different relative positions between the contact portion and the contact center point when the linear region of the chain is viewed from the chain width direction W may be provided.
In the embodiment shown in FIG. 14, three or more types of first pins having different distances between the contact center points of the pair of end faces may be provided.
Furthermore, in the embodiment shown in FIG. 15, three or more types of first pins having different angles of attack may be provided.

Further, in the embodiment shown in FIG. 16, three or more types of first pins having different rigidity may be provided.
Further, in each of the above embodiments, two or more types of random means described above may be used in combination.
Further, the first pin may be loosely fitted in the rear through hole of each link so as to be relatively movable. Moreover, the 2nd pin 4 may be loosely fitted by the front through-hole of each link so that relative movement is possible. Further, the second pin 4 may be adapted to engage with the pulleys 60 and 70.

Further, a member having a power transmission part similar to the end face of the first pin is disposed in the vicinity of each of the pair of end parts in the longitudinal direction of the first pin, and the first pin and the power transmission part are provided. A power transmission block including a member may be provided and used as a predetermined power transmission member.
Moreover, you may mutually replace the arrangement | positioning of the front through-hole of a link, and a rear through-hole. Furthermore, you may provide a communication groove (slit) in the column part of a link. A slit may be smaller than the height of each through-hole, and may be enlarged to the same extent. If the height is small, the rigidity of the link increases. If the height is large, the amount of elastic deformation (flexibility) increases and the stress generated in the link can be further reduced. What is necessary is just to set the height of a slit suitably according to load conditions.

Furthermore, although the end surface of the first pin has a shape including a part of the spherical surface, it may be a trapezoidal end surface so that the contact portion with the sheave surface of the pulley becomes a flat surface. In this case, the surface pressure of the contact portion between the end surface and the sheave surface is reduced, and durability is improved.
Further, the present invention is not limited to a mode in which the groove widths of both the drive pulley 60 and the driven pulley 70 are changed, and may be a mode in which only one of the groove widths is changed and the other is a fixed width that does not change. good. Furthermore, although the aspect in which the groove width continuously changes (steplessly) has been described above, the groove width may be changed stepwise or may be applied to other power transmission devices such as a fixed type (stepless). .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view schematically showing a main configuration of a chain type continuously variable transmission as a power transmission device including a power transmission chain according to an embodiment of the present invention. It is a partial expanded sectional view of the drive pulley (driven pulley) and chain of FIG. It is typical sectional drawing of a continuously variable transmission, (A) has shown the state by which the effective radius of the drive pulley was made into the minimum while the effective radius of the driven pulley was made into the maximum, (B) is a drive pulley. The effective radius of the driven pulley is maximized and the effective radius of the driven pulley is minimized. It is sectional drawing of the principal part of a chain. It is sectional drawing which follows the VV line | wire of FIG. 4, and has shown the chain of the linear area | region. It is a side view of the chain of a bending area. It is the figure which projected the 1st part of the front part of a 1st pin on the projection plane orthogonal to a chain width direction. It is a figure for demonstrating the 1st part of the front part of a 1st pin. It is a figure for demonstrating the cross-sectional shape of the 1st part of a front part. It is a figure for demonstrating the cross-sectional shape of the 1st part of a front part. It is a partial cross section figure of the principal part of another embodiment of this invention. It is a partial cross section figure of the principal part of another embodiment of this invention. It is a side view of the principal part of further another embodiment of this invention. It is a figure for demonstrating another embodiment of this invention, (A) and (B) are sectional drawings which looked at the 1st pin from the chain advancing direction, respectively. It is a side view of the principal part of further another embodiment of this invention. It is a figure for demonstrating another embodiment of this invention, (A) and (B) are each the side views which looked at the 1st pin from the chain advancing direction. It is a partial cross section figure of the principal part of another embodiment of this invention.

Explanation of symbols

0 _{INV '} ... origin, 1 ... chain (power transmission chain), 2, 2E ... link, 2K ... link (a pair member made up of links), 3, 3D, 3F, 3G, 3H, 3J ... first pin (predetermined Power transmission member), 4... 2nd pin (a mating member made up of a member interposed between the links), 12, 12D... (Of the first pin) front (opposite portion, change rate decreasing portion). , 16 ... (first pin) end, 17, 17F, 17H ... (first pin) end face (power transmission part), 60, 70 ... pulleys (first and second pulleys), 62a, 63a, 72a, 73a ... sheave surface, 100 ... continuously variable transmission (power transmission device), 200 ... connecting member, J ... projection plane, Rb ... base circle radius, T, TD, TK ... contact part, V ... orthogonal direction (The direction perpendicular to both the chain travel direction and the chain width direction), W ... Down width direction, X ... chain traveling direction, phi ... bending angle, .phi.0 ... allowable bending angle.

Claims (7)

Multiple links,
A plurality of connecting members for connecting the plurality of links so as to be able to bend each other
The connecting member includes a predetermined power transmission member having a facing portion facing a pair member formed of either one of a link or a member interposed between the links,
The opposing portion is in rolling contact with the pair of members at a contact portion that is displaced along with the bending between the links,
The facing portion is provided with a rate-of-change decreasing portion in which the rate of change of the displacement of the contact portion decreases in accordance with an increase in the bending angle between the links.
The power transmission chain according to claim 1, wherein the contact portion when the bending angle is zero is disposed in the change rate decreasing portion.   2. The power transmission chain according to claim 1, wherein the facing portion includes a change rate decreasing portion. 3. The predetermined power transmission member according to claim 1, wherein the predetermined power transmission member is projected onto a projection plane orthogonal to the chain width direction, and the direction along the chain traveling direction is set to the x direction, and is orthogonal to both the chain traveling direction and the chain width direction. The trajectory of the projected point of the contact portion in the projection plane when the direction along the direction to be moved is the y direction is expressed by the following equation with the projected point of the contact portion in the linear region as the origin: chain.
x = −Rbφ0 + Rbsinφ + Rb (φ0−φ) cosφ
y = Rb−Rbcosφ + Rb (φ0−φ) sinφ
Where Rb: basic circle radius (mm) of the locus of the projected point of the contact portion, φ0: allowable bending angle (rad) between links, φ: bending angle (rad) between links.   4. The power transmission chain according to claim 1, 2, or 3, wherein the contact portion when the bending angle is negative is arranged in the change rate decreasing portion. In any one of Claims 1-4, the said predetermined power transmission member is each formed in elongate, The power transmission part for pulley engagement is included in each of a pair of edge part,
A power transmission chain comprising randomizing means for randomizing an engagement cycle when each of the power transmission units is sequentially engaged with a pulley.   6. The randomizing means according to claim 5, wherein the randomizing means randomly selects a plurality of types of power transmission members having different relative positions between the contact portion when the linear region of the chain is viewed from the chain width direction and the contact center point with respect to the sheave surface of the pulley. Arrangement, Randomly disposing a plurality of types of power transmission members with different distances between the contact center points of the pair of end faces with respect to the sheave surface, Plurality with different inclinations when the linear region of the chain is viewed from the chain width direction A power transmission chain comprising at least one of randomly arranging different types of power transmission members and randomly arranging a plurality of types of power transmission members having different elastic moduli. First and second pulleys having opposing pair of conical sheave surfaces, respectively, wound around between these pulleys, claim 1-6 for transmitting power in contact with the sheave surfaces A power transmission device comprising the power transmission chain according to claim 1.

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