JP2009228748A - Power transmission chain, power transmission device having the same and method of manufacturing power transmission chain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission chain, allowing design change to be easily made for restraining abrasion, without causing the abrasion. <P>SOLUTION: In this power transmission chain, a first pin 3 for connecting a plurality of links 2 includes an end surface 17 contacting with a sheave surface of a pulley and a flat rear part 13 turning in the opposite direction of the chain advancing direction X. The end surface 17 is formed with a convex curved part 20 for forming a contact area 21 between the pulley and itself. When viewed from the chain width direction W, the convex curved part 20 has the center M and the first main direction N1 for satisfying the following conditions (1) and (2). The condition (1): the center M is arranged in a position coincident with both the center in the thickness direction K2 orthogonal to the rear part 13 and the center in the height direction K1 along the rear part 13 or in the vicinity of this position in the end surface 17, and the condition (2): the first main direction N1 is inclined at a predetermined inclination angle P to the rear part 13. The inclination angle P is set in response to the size of an entering angle of the first pin 3 to a drive pulley. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power transmission chain, a power transmission device including the power transmission chain, and a method for manufacturing the power transmission chain.

For example, an endless power transmission chain used in a power transmission device such as a pulley type continuously variable transmission (CVT) of an automobile is formed by connecting a plurality of link plates with pins, Used in a state of being wound around a pulley.
Power is transmitted between the power transmission chain and the pulley by engaging the pair of end surfaces of the pin with the sheave surface of the pulley.
JP 2006-144929 A

  In the case of CVT, the winding radius of the pulley related to the power transmission chain (hereinafter referred to as the pulley winding radius) varies. Further, the upper and lower limits of the pulley winding radius vary depending on the specification of the vehicle on which the CVT is mounted. For this reason, when the CVT is driven, the angle of the pin entering the pulley is not constant. For this reason, the part which contacts a pulley among pin end surfaces changes according to the winding radius of a pulley. As a result, depending on the wrapping radius of the pulley, the edge of the pin end surface may come into contact with the pulley. When edge contact occurs, wear of the pin end surface and the sheave surface of the pulley is promoted.

In order to suppress edge contact, for example, it is conceivable to change the direction (attack angle) of the pin with respect to the link in accordance with the CVT specification. However, in this case, it is necessary to change the direction of the pin with respect to the link by changing the shape of the link. Since the link is usually formed by pressing, it takes time and effort to change the shape of the mold.
SUMMARY OF THE INVENTION The present invention has been made under such a background, and a power transmission chain, a power transmission device including the power transmission chain, and a power transmission chain that are less susceptible to wear and that can be easily changed in design to suppress wear, and a power transmission chain. It aims to provide a method.

  In order to achieve the above object, the present invention extends a plurality of links (2) arranged in the chain traveling direction (X) and a chain width direction (W) perpendicular to the chain traveling direction and connects the plurality of links to each other. A plurality of connecting members (50), and the connecting members have end faces (17, 17A) that come into contact with the sheave surfaces (62a, 63a, 72a, 73a) of the pulleys (60, 70) so as to be able to transmit power. A power transmission member (3, 3A) having a scale, the power transmission member including a flat rear surface (13) extending along the chain width direction and facing the direction opposite to the chain traveling direction; A convex curved portion (20, 20A) for forming a contact region (21, 21A) between the end face and the pulley when the power transmission member bites into the pulley is formed, and the power transmission member is connected to the chain. Width When viewed from above, the convex curved portion has a center (M) and a main direction (N1, N1A) satisfying the following conditions 1) and 2): 1A). 1) The direction perpendicular to the rear surface is the thickness direction (K2) of the power transmission member, and the direction along the rear surface and perpendicular to the chain width direction is the height direction (K1) of the power transmission member. The center of the bending portion is disposed at a position that coincides with or near both the thickness center and the height center of the power transmission member. 2) When the power transmission chain is viewed from the chain width direction, the main direction of the convex curved portion is inclined at a predetermined inclination angle (P) with respect to the rear surface (Claim 1).

  In general, the power transmission chain is wound around a plurality of (for example, two) pulleys. And the power transmission member sent out from the upstream pulley in the chain traveling direction is sequentially bitten by the downstream pulley. Here, when a shift is performed between the upstream pulley and the downstream pulley, the power transmission member is engaged with the downstream pulley with a predetermined entry angle. As a result, a contact region tends to be formed in the vicinity of the outer peripheral edge (edge) of the end surface among the convex curved portions on the end surface of the power transmission member. Further, the position of the contact area on the end face varies depending on the approach angle.

  According to the present invention, the main direction of the convex curved portion is inclined at a predetermined inclination angle with respect to the rear surface, and the center of the convex curved portion coincides with both the thickness center and the height center of the power transmission member. Or it arrange | positions in the vicinity of this position. As a result, when the power transmission member is engaged with the pulley with a predetermined entry angle, the portion of the end surface where the contact region is formed can be disposed near the center of the end surface, and the area of the contact region can be sufficiently increased. Can be secured. As a result, it is possible to prevent the edge contact of the sheave surface of the pulley with the outer peripheral edge of the end surface. Therefore, local durability of the end face and slipping on the pulley can be prevented, and practical durability can be sufficiently secured. Also, for power transmission chains with different angles of approach to the pulley, the position of the contact area on the end surface will differ, but for such power transmission chains, the main direction of the convex curved portion on the end surface It is only necessary to make a small change to change the direction of the design, and a design change for suppressing wear can be easily performed.

In the present invention, the inclination angle may be set in accordance with the magnitude of the approach angle (Z) of the power transmission member with respect to the pulley (claim 2). In this case, it is possible to secure a larger area of the portion of the end surface where the contact region is formed.
Further, in the present invention, the first and second pulleys (60, 70) each having a pair of conical sheave surfaces facing each other and the pulleys are wound around the pulleys and engaged with the sheave surfaces. In some cases, the power transmission chain may transmit power.

In this case, it is possible to realize a power transmission device that is excellent in practical durability and can easily change the design of the power transmission member in accordance with a change in the approach angle of the power transmission member.
Further, the present invention includes a plurality of links arranged in the chain traveling direction, and a plurality of connecting members extending in the chain width direction perpendicular to the chain traveling direction and connecting the plurality of links to each other. An elongate power transmission member having an end surface that is in contact with the sheave surface of the sheave surface, and the power transmission member has a flat rear surface that extends along the chain width direction and faces away from the chain traveling direction. In the method of manufacturing a power transmission chain, the end face is formed with a convex curved portion for forming a contact region between the end face and the pulley when the power transmission member is engaged with the pulley. Without changing the position of the outer periphery (11) of the power transmission member relative to the link in the region, the chain There is provided a method of manufacturing a power transmission chain, characterized in that to change the main direction of orientation of the convex curved portion when viewed power transmission member in the area from the chain width direction (claim 4).

Typically, the link is press molded using a mold. For this reason, by optimizing the direction of the power transmission member held by the link by changing the shape of the link in accordance with the change in the approach angle of the power transmission member, it takes a lot of trouble such as changing the mold. In addition, costly work is required.
On the other hand, according to the present invention, the end face shape can be optimized according to the change of the approach angle of the power transmission member by a slight change work of changing the shape of the end face formed by grinding or the like. Therefore, when the power transmission member is engaged with the pulley with a predetermined entry angle, the design change work for sufficiently securing the area of the end surface where the contact region is formed can be simplified. In this way, a contact area with a sufficient area can be formed on the end face according to the approach angle of the power transmission member with a simple operation, so that it is possible to prevent edge contact with the sheave face of the pulley on the outer peripheral edge of the end face. In addition, local wear on the end face can be prevented and sufficient practical durability can be secured.

  In the above description, numbers in parentheses represent reference numerals of corresponding components in the embodiments described later, but the scope of the claims is not limited by these reference numerals.

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 drive source of a vehicle so as to be capable of transmitting power, and includes a fixed sheave 62 and a 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.

  Each sheave surface 62a, 63a is inclined with respect to the first orthogonal plane B1 orthogonal to the central axis A1 of the drive pulley 60, and the generatrix of each sheave surface 62a, 63a and the first orthogonal plane B1 The pulley half angle C as an angle formed is set to 11 °, for example. 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) so that the effective radius D1 (hereinafter also referred to as the effective radius D1 of the pulley 60) of the pulley 60 can be changed. It has become.

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 able to transmit power. 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.
Each sheave surface 73a, 72a is inclined with respect to a second orthogonal plane B2 orthogonal to the central axis A2 of the driven pulley 70, and the generatrix of each sheave surface 73a, 72a and the second orthogonal plane B2 The pulley half angle C as an angle formed is set to 11 °, for example. The pulley half angle C of the drive pulley 60 and the pulley half angle C of the driven pulley 70 are equal.

  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. Thereby, the chain 1 is moved, and the effective radius D2 of the pulley 70 related to the chain 1 (hereinafter, also referred to as the effective radius D2 of the pulley 70) can be changed.

FIG. 3 is a cross-sectional view of the main part of the chain 1. FIG. 4 is a longitudinal sectional view of the main part of the linear region of the chain 1. In the following, when the description is made with reference to FIG. 4, the linear region of the chain 1 will be described with reference to the state viewed from the chain width direction W.
Referring to FIGS. 3 and 4, chain 1 includes a plurality of links 2 and a plurality of connecting members 50 that connect these links 2 so that they can be bent.

Hereinafter, a direction parallel to the traveling direction of the chain 1 is referred to as a chain traveling direction X, and a direction parallel to the longitudinal direction of the connecting member 50 among the directions orthogonal to the chain traveling direction X is referred to as a chain width direction W. A direction orthogonal to both the direction X and the chain width direction W is referred to as an orthogonal direction V.
One V1 in the orthogonal direction V is a direction facing the outside in the chain radial direction when the chain 1 is bent, and the other V2 in the orthogonal direction V is a chain radial direction when the chain 1 is bent. It is the direction facing the inside.

Each link 2 is formed by press-molding a plate-shaped steel plate with a mold, and includes a front through hole 9 as a first through hole arranged in the front and rear of the chain traveling direction X, and a second through hole. A rear through hole 10 is formed. The links 2 are aligned in the chain traveling direction X and aligned in the chain width direction W.
The links 2 adjacent to each other in the chain traveling direction X are relatively formed in the front through hole 9 of the link 2 that is relatively upstream in the chain traveling direction X and the rear penetration of the link 2 that is relatively downstream in the chain traveling direction X. The holes 10 correspond to each other in the chain width direction W. The links 2 adjacent to each other in the chain traveling direction X are connected so as to be bendable by the connecting members 50 inserted through the corresponding through-holes 9 and 10, and the endless chain 1 is formed as a whole.

Each connecting member 50 includes a first pin 3 and a second pin 4 as power transmission members.
The first pin 3 is a long member extending in the chain width direction W. A peripheral surface 11 as an outer peripheral portion of the first pin 3 is formed as a smooth surface extending in parallel with the chain width direction W, and includes a front portion 12 as a facing portion facing forward in the chain traveling direction X, and a chain. It has a rear portion 13 as a flat rear surface facing in the direction opposite to the traveling direction X, and one end portion 14 and the other end portion 15 as a pair of end portions opposite to each other in the orthogonal direction V.

  The front portion 12 faces the paired second pins 4 and rolls and slides at a rear flat portion 19 (to be described later) of the second pins 4 and a contact portion T (contact point as viewed from the chain width direction W). In contact. The rear portion 13 is a flat surface and has a predetermined angle of attack E with respect to a third orthogonal plane D3 orthogonal to the chain traveling direction X. The angle of attack E is, for example, about 5 ° to 12 °. The rear portion 13 extends along an inclined direction F inclined with respect to the orthogonal direction V when the chain linear region is viewed from the chain width direction W, and faces the other V2 side of the orthogonal direction V. The angle formed by the inclination direction F and the orthogonal direction V is the angle of attack E.

With reference to FIG. 2 and FIG. 4, end surfaces 17 are respectively provided on the pair of end portions 16 in the longitudinal direction of the first pin 3. Each end surface 17 is convexly curved toward the outer side in the chain width direction W and faces the other V2 side in the orthogonal direction V. One end 14 of the peripheral surface 11 of the first pin 3 is formed wider in the chain width direction W than the other end 15.
A convex curved portion 20 is formed on each end surface 17. The convex curved portion 20 is a portion where the contact region 21 is formed, and is formed on at least a part of the corresponding end surface 17 (the entire region in the present embodiment).

The contact region 21 is a region that comes into contact with the corresponding pulleys 60 and 70 in the end surface 17 when the first pin 3 bites into the corresponding pulleys 60 and 70. That is, these contact regions 21 are in frictional contact (engagement) with the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70 through the thin film-like lubricating oil film.
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. The first pin 3 is formed of a material having high strength and excellent wear resistance, such as bearing steel (SUJ2), for example, because the convex curved portion 20 of the end surface 17 directly contributes to power transmission. .

3 and 4, the second pin 4 (also referred to as a strip or an interpiece) is a long member extending in the chain width direction W and formed of the same material as that of the first pin 3. It is.
The second pin 4 is formed shorter than the first pin 3 so that the pair of end portions do not contact the sheave surfaces of the pulleys, and with respect to the first pin 3 that makes a pair, It is arranged in front of the chain traveling direction X.

The peripheral surface 18 of the second pin 4 is a smooth surface extending in parallel with the chain width direction W, and has a rear flat portion 19 as a facing portion facing in a direction opposite to the chain traveling direction X. Yes. The rear flat portion 19 is a flat surface that is formed at an intermediate portion of the second pin 4 in the orthogonal direction V and that is orthogonal to the chain traveling direction X, and is opposed to the front portion 12 of the paired first pin 3. ing.
The chain 1 is a so-called press-fit type chain. Specifically, the corresponding first pin 3 is loosely fitted in the front through hole 9 of each link 2, and the corresponding second pin 4 is press-fitted and fixed, and the rear through hole of each link 2. 10, the corresponding first pin 3 is press-fitted and fixed, and the corresponding second pin 4 is loosely fitted.

  With the above configuration, the rear flat portion 19 of the second pin 4 paired with the front portion 12 of the first pin 3 is a contact portion that moves in accordance with the bending between the links 2 adjacent to each other in the chain traveling direction X. Rolling and sliding contact with each other on T. Rolling sliding contact refers to contact including at least one of rolling contact and sliding contact. Each of the first and second pins 3 and 4 may be loosely fitted in the corresponding front through hole 9 and rear through hole 10.

  The front portion 12 has a curved shape protruding in the chain traveling direction X. Specifically, the cross-sectional shape of a portion of the front portion 12 on the one V1 side in the direction V orthogonal to the contact portion T1 in the linear region of the chain 1 includes an involute curve. Moreover, the cross-sectional shape of the part which exists in the other V2 side of the orthogonal | vertical direction V with respect to the said contact part T1 among the front parts 12 is made into the smooth curve line. Thereby, when viewed from the chain width direction W, the movement trajectory of the contact portion T accompanying the bending between the corresponding links 2 includes an involute curve with the first pin 3 as a reference.

Thereby, when the adjacent links 2 are bent, the corresponding first and second pins 3 and 4 can smoothly roll and come into contact with each other, and the smooth bending of the links 2 can be achieved. As a result, the string vibration of the chain 1 can be suppressed.
5A is a side view of the first pin 3 viewed from the chain width direction W, and FIG. 5B is a cross-sectional view taken along the line VB-VB in FIG. FIG. 5C is a cross-sectional view taken along the line VC-VC in FIG.

Referring to FIG. 5A, the thickness direction K2 of the first pin 3 is a direction perpendicular to the rear portion 13. The length (thickness) of the first pin 3 in the thickness direction K2 is, for example, about 3 mm.
Further, the first pin 3 has a height direction K1 along the rear portion 13 and perpendicular to the chain width direction W. The length (height) of the first pin 3 in the height direction K1 is, for example, about 7 mm.

The convex curved portion 20 is a surface that is formed by applying a crowning process to the end surface 17 and projects outward in the chain width direction W, and the whole is smoothly convex curved.
As one of the features of the present embodiment, when the first pin 3 is viewed from the chain width direction W, the convex curved portion 20 has a center M and a first main direction N1 that satisfy the following conditions 1) and 2): It is in having.

  1) The center M of the convex curved portion 20 is disposed at a position that coincides with or near both the center of the end surface 17 with respect to the thickness direction K2 and the center of the end surface 17 with respect to the height direction K1. In addition, the above-mentioned “near” means that the position that coincides with both the center of the end surface 17 with respect to the thickness direction K2 and the center of the end surface 17 with respect to the height direction K1 is substantially the same position. The center M may not completely coincide with the coincident position due to a manufacturing error or the like.

2) When the first pin 3 is viewed from the chain width direction W, the first main direction N1 is inclined at a predetermined inclination angle P with respect to the rear portion 13.
The center of the end surface 17 in the thickness direction K2 described above refers to a position that passes through the center of the maximum width portion 22 of the first pin 3 in the thickness direction K2 and is parallel to the rear portion 13. Further, the center of the end surface 17 with respect to the height direction K1 refers to a position passing through the center of the maximum width portion 23 with respect to the height direction K1 and orthogonal to the rear portion 13.

When viewed from the chain width direction W, the convex curved portion 20 has a first main direction N1 and a second main direction N2 orthogonal to the first main direction N1. The convex curved portion 20 is formed by performing a crowning process along the first main direction N1 and a crowning process along the second main direction N2.
When viewed from the chain width direction W, the predetermined inclination angle P formed by the first main direction N1 with respect to the rear portion 13 (height direction K1) is, for example, greater than 0 ° and not greater than 15 °. By setting the angle to 15 ° or less, a realistic layout of the convex curved portion 20 can be realized. The upper limit of the inclination angle P is preferably 10 °.

In the present embodiment, the first main direction N1 is a direction that proceeds to the other V2 side of the orthogonal direction X as it proceeds in the chain traveling direction X, and passes through the center M. FIG. 5B is a cross-sectional view of the first pin 3 taken along a first parallel plane Q1 along the first main direction N1 and parallel to the chain width direction W.
Referring to FIG. 5A, in the present embodiment, second main direction N2 is a direction that proceeds toward one V1 side of orthogonal direction X as it proceeds in chain traveling direction X. 5C is a cross-sectional view of the first pin 3 cut along a second parallel plane Q2 along the second main direction N2 and parallel to the chain width direction W. FIG.

  Referring to FIGS. 5A and 5B, when the first pin 3 is cut along the first parallel plane Q1, the cross-sectional shape of the convex curved portion 20 is the first curvature radius. It becomes an arc line having a main curvature radius R1. The first main radius of curvature R1 is larger than a second main radius of curvature R2, which will be described later, and is, for example, about 160 mm. A center M is arranged on the first parallel plane Q1. In the first parallel plane Q1, the angle formed by the normal S of the convex curved portion 20 at the center M and the chain width direction W is equal to the pulley half angle C. The cross-sectional shape of the convex curved portion 20 when the convex curved portion 20 is cut along an arbitrary plane parallel to the first parallel plane Q1 is an arc line having the first main radius of curvature R1.

  Referring to FIGS. 5A and 5C, when the first pin 3 is cut along the second parallel plane Q2, the cross-sectional shape of the convex curved portion 20 is the first curvature radius. The arc line has a main curvature radius R2. The second main curvature radius R2 is, for example, about 50 mm. The center M of the convex curved portion 20 is arranged on the second parallel plane Q2. The cross-sectional shape of the convex curved portion 20 when the convex curved portion 20 is cut along an arbitrary plane parallel to the second parallel plane Q2 is an arc line having the second main curvature radius R2.

  Referring to FIGS. 5A and 5B, the inclined plane H is inclined by the pulley half angle C with respect to the plane G orthogonal to the chain width direction W, and proceeds to the other V2 in the orthogonal direction V. When the convex curved portion 20 is cut along the inclined plane H that goes inward in the chain width direction W, the outer peripheral shape of the cross section of the convex curved portion 20 becomes an elliptical shape 24 (in FIG. An oval shape 24a is illustrated). When viewed from the chain width direction W, the oval shape 24 is vertically long in the first main direction N1 and short in the second main direction N2. The end surface 17 viewed from the oblique direction J perpendicular to the inclined plane H and the end surface 17 viewed from the chain width direction W have substantially the same shape.

  With reference to FIG. 5A, the contact region 21 of the first pin 3 is arranged so as to avoid the outer peripheral edge 25 of the end surface 17 of the first pin 3. When the contact region 21 is viewed from the chain width direction W, the contact region 21 has an elliptical shape that is vertically long in the first main direction N1 and short in the second main direction N2. That is, the contact region 21 has the same or similar shape as the elliptical shape 24 (in FIG. 5A, the contact region 21 that is the same as the elliptical shape 24a is shown). The center of the contact region 21 substantially coincides with the center of the convex curved portion 20.

Referring to FIGS. 2 and 5A, effective radii D1 and D2 of the pulleys 60 and 70 are defined as follows. In other words, the effective radius D1 of the drive pulley 60 is such that the pulley 60 between the center M of the convex curved portion 20 of the end surface 17 of the first pin 3 sandwiched by the drive pulley 60 and the center axis A1 of the drive pulley 60. Defined as radial distance.
Similarly, the effective radius D2 of the driven pulley 70 is the pulley 70 between the center M of the convex curved portion 20 of the end surface 17 of the first pin 3 sandwiched by the driven pulley 70 and the center axis A2 of the driven pulley 70. Is defined as the radial distance.

FIGS. 6A to 6C are schematic views of main parts for explaining the operation of the chain 1 in the continuously variable transmission 100. In FIGS. 6A to 6C, the first pin 3 is exaggerated and enlarged.
Referring to FIG. 6A, when the speed reduction ratio of continuously variable transmission 100 is the highest (during underdrive), effective radius D1 of drive pulley 60 is set to the minimum value, and effective radius D2 of driven pulley 70 is set. Is the maximum value. When deceleration is performed by continuously variable transmission 100, effective radius D1 is relatively small and effective radius D2 is relatively large.

Referring to FIG. 6B, when the continuously variable transmission 100 does not perform a shift, that is, when the reduction ratio = the speed increase ratio = 1, the effective radius D1 of the drive pulley 60 and the driven pulley 70 The effective radii D2 are equal to each other.
Referring to FIG. 6C, when the speed increasing ratio of continuously variable transmission 100 is the highest (during overdrive), effective radius D1 of drive pulley 60 is set to the maximum value, and effective radius of driven pulley 70 is set. D2 is set to the minimum value. When the speed increase is performed by the continuously variable transmission 100, the effective radius D1 is relatively large and the effective radius D2 is relatively small.

Referring to FIG. 6A, here, the chain 1 is a pull type chain, and of the two chain linear regions Y1 and Y2 existing between the pulleys 60 and 70, the side pulled into the drive pulley 60 When the drive pulley 60 pulls the chain straight region Y1, the tensile force acts on the chain straight region Y1, and the driven pulley 70 is driven to rotate.
The chain 1 is engaged with the drive pulley 60 at a predetermined entry angle Z. The approach angle Z at this time is defined as an angle formed by two planes α1 and α2, for example. One plane α1 is a plane including the central axes A1 and A2 of the pulleys 60 and 70. The other plane α2 is a plane including the center M of the convex curved portion 20 of each first pin 3 in one chain linear region Y1.

As shown in FIG. 6A, when the continuously variable transmission 100 is decelerated, the approach angle Z takes a positive value. On the other hand, as shown in FIG. 6C, when the continuously variable transmission 100 is accelerated, the approach angle Z takes a negative value.
In the present embodiment, the absolute value of the approach angle Z at the time of underdrive is relatively large, and the absolute value of the approach angle Z at the time of overdrive is relatively small. Accordingly, the maximum absolute value of the approach angle Z is larger on the positive side than on the negative side. For this reason, the shape of the convex curved part 20 of the end surface 17 is determined on the basis of the time of the underdrive in which the approach angle Z becomes a positive side. Specifically, referring to FIG. 7, as described above, as the first main direction N1 of the convex curved portion 20 proceeds in the chain traveling direction X, the other V2 in the orthogonal direction V (the inner diameter side of the chain) Try to go forward.

  During underdrive, the rear portion 13 is inclined with respect to the plane α1. On the other hand, when viewed from the chain width direction W, the first main direction N1 is substantially orthogonal to the plane α1. As a result, the contact region 21 formed when the first pin 3 is engaged with the drive pulley 60 is formed at a position away from the outer peripheral edge 25 (edge) of the end surface 17 and around the center M. Formed.

  As shown in FIGS. 8A and 8B, the absolute value of the approach angle Z at the time of underdrive is relatively small, and the absolute value of the approach angle Z at the time of overdrive is relatively large. The maximum value of the absolute value of the approach angle Z of the chain 1A is larger on the negative side than on the positive side. For this reason, the shape of the convex curved portion 20A of the end face 17A is determined with reference to the overdrive when the approach angle Z is on the negative side. In FIG. 8A and FIG. 8B, the first pin 3A is exaggerated and enlarged.

  Specifically, as shown in FIG. 9, in the chain straight region Y1A, as the first main direction N1A of the convex curved portion 20A advances in the chain traveling direction X, one of the orthogonal directions V V1 (the chain outer diameter side) ). With respect to the configuration except that the directions of the first and second main directions N1A and N2A are as shown in FIG. 9, the chain 1 and the chain 1A have the same configuration.

  As shown in FIG. 10, during overdrive, the rear portion 13 is inclined with respect to the plane α1. On the other hand, when viewed from the chain width direction W, the first main direction N1A is substantially orthogonal to the plane α1. As a result, the contact region 21A formed when the first pin 3A is engaged with the drive pulley 60 is formed at a position away from the outer peripheral edge 25 (edge) of the end face 17A and around the center M. Formed.

Referring to FIGS. 6 and 8, in this way, the maximum absolute value of the approach angle Z of each of the first pins 3 and 3A with respect to the drive pulley 60 and the approach angle Z at this maximum value are positive. Based on whether the value is a negative value or not, the inclination angle P related to the convex curved portions 20 and 20A is appropriately set.
4 and 9, by appropriately setting the inclination angle P, the first and second main directions N1, N2 of each convex curved portion 20, 20A when viewed from the chain width direction W; N1A , N2A can be changed. Even when the inclination angle P is changed, the position of the peripheral surface 11 of the first pins 3 and 3A with respect to the link 2 in the chain linear regions Y1 and Y1A is not changed.

6 and 8, for each of the chains 1 and 1A, the first pins 3 and 3A sent out from the driven pulley 70 as the upstream pulley in the chain traveling direction X are sequentially moved to the downstream side. It is caught in a drive pulley 60 as a pulley.
When a shift is performed between the driven pulley 70 and the drive pulley 60, the first pins 3 and 3A are engaged with the drive pulley 60 with a predetermined entry angle Z. As a result, of the end surfaces 17 and 17A of the first pins 3 and 3A, the contact regions 21 and 21A tend to be easily formed near the outer peripheral edge 25 (edge) of the end surfaces 17 and 17A.

However, according to the present embodiment, the first main directions N1, N1A of the convex curved portions 20, 20A are inclined at a predetermined inclination angle P with respect to the rear portion 13 of the first pins 3, 3A, and The center M of the convex curved portions 20 and 20A is arranged at a position that coincides with or near both the thickness center and the height center of the corresponding first pins 3 and 3A.
As a result, when the first pins 3 and 3A are engaged with the drive pulley 60 with the approach angle Z, the portions of the end surfaces 17 and 17A where the contact areas 21 and 21A are formed are formed on the end surfaces 17 and 17A. While being able to arrange | position in the center vicinity, the area of 21 A of contact regions and 21A can fully be ensured. As a result, it is possible to prevent the edge contact of the sheave surfaces 62a and 63a of the drive pulley 60 with the outer peripheral edge 25 of the end surfaces 17 and 17A. Therefore, it is possible to prevent local wear of the end faces 17 and 17A and slip with respect to the drive pulley 60 and sufficiently ensure practical durability. Wear of the sheave surfaces 62a and 63a of the drive pulley 60 can also be suppressed, and the practical durability of the drive pulley 60 can be improved. In addition, the noise per edge can be reduced by reducing the contact noise when each first pin 3, 3 </ b> A contacts the drive pulley 60 by preventing per edge.

  Further, for the chain 1A in which the approach angle Z to the drive pulley 60 is different from that of the chain 1, the position of the contact region 21A on the end face 17A is different, but for such a chain 1A, the end face A small change that changes the direction of the first main direction N1A of the convex curved portion 20A of 17A to be different from the main direction N1 is sufficient, and a design change for suppressing wear can be easily performed.

More specifically, by setting the inclination angle P in accordance with the magnitude of the entry angle Z of the first pins 3 and 3A with respect to the drive pulley 60, the contact areas 21 and 21A of the end faces 17 and 17A are set. As a result, it is possible to secure a larger area of the portion where the film is formed.
From the above, it is excellent in practical durability and quietness, and furthermore, it is easy to change the design of the first pins 3 and 3A according to the change of the approach angle Z of the first pins 3 and 3A to the drive pulley 60. A continuously variable transmission 100 that can be implemented is realized.

  Further, when manufacturing the chain 1 and the chain 1A, the position of the peripheral surface 11 of the first pins 3 and 3A with respect to the link 2 in the chain linear regions Y1 and Y1A is not changed, that is, the angle of attack E is changed. do not do. On the other hand, depending on the magnitude of the approach angle Z of the first pins 3 and 3A with respect to the drive pulley 60, the first main directions N1 and N1A of the convex curved portions 20 and 20A when viewed from the chain width direction W are shown. The direction is changed.

The link 2 is press-molded using a mold. For this reason, the direction of the first pins 3 and 3A held by the link 2 is changed by changing the shape of the link 2 in accordance with the change of the approach angle Z of the first pins 3 and 3A to the drive pulley 60. Optimizing requires a laborious and costly operation such as changing the mold.
On the other hand, in the present embodiment, the first pins 3 and 3A to the drive pulley 60 can be changed by slightly changing the shapes of the end faces 17 and 17A formed by grinding such as crowning. The shape of the end faces 17 and 17A can be optimized according to the change of the approach angle Z. Therefore, when each of the first pins 3 and 3A is engaged with the drive pulley 60 with the approach angle Z, a sufficient area of the portion of the end surfaces 17 and 17A where the contact regions 21 and 21A are formed is secured. The design change work for this is simple. As described above, since the contact areas 21 and 21A having a sufficient area can be formed on the end faces 17 and 17A according to the approach angle Z by a simple work, the sheaves of the drive pulley 60 are formed on the outer peripheral edge 25 of the end faces 17 and 17A. Edge contact with the surfaces 62a and 63a can be prevented, and local wear of the end surfaces 17 and 17A can be prevented to sufficiently ensure practical durability.

The present invention is not limited to the contents of the above-described embodiments, and various modifications can be made within the scope of the claims. For example, the present invention can be applied to a so-called block type chain including a power transmission block that is fixed to a pin or the like as a power transmission member and protrudes outward in the chain width direction from the pin.
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 only one of the groove widths may be changed and the other may be a fixed width that does not change. good. In the above description, the groove width is continuously (stepless) changed. However, the groove width may be changed stepwise or may be applied to other power transmission devices such as a fixed type (no shift). .

It is a perspective view showing typically the principal part composition of the continuously variable transmission provided with the power transmission chain concerning one embodiment of the present invention. It is a partial expanded sectional view of the drive pulley (driven pulley) and chain of FIG. It is a cross-sectional view of the principal part of a chain. It is a longitudinal cross-sectional view of the principal part of the linear area | region of a chain. (A) is a side view of the first pin viewed from the chain width direction, (B) is a cross-sectional view taken along line VB-VB in FIG. 5 (A), and (C) is FIG. It is sectional drawing which follows the VC-VC line of (A). (A)-(C) are the schematic diagrams of the principal part for demonstrating the operation | movement of the chain in a continuously variable transmission, respectively. It is an enlarged view of the principal part of FIG. (A) And (B) is a schematic diagram at the time of making the maximum value of the absolute value of the approach angle of the 1st pin into a drive pulley differ. It is a partial cross section figure of the principal part of the chain linear area | region of FIG. It is an enlarged view of the principal part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Power transmission chain, 2 ... Link, 3, 3A ... 1st pin (power transmission member), 11 ... (1st pin's) peripheral surface (outer peripheral part), 13 ... Rear part (rear surface), 17, 17A ... End face, 20, 20A ... Convex curve part, 21, 21A ... Contact area, 50 ... Connecting member, 60, 70 ... Pulley, 62a, 63a, 72a, 73a ... Sheave face, 100 ... Continuously variable transmission (power transmission device ), K1 ... Height direction, K2 ... Thickness direction, M ... Center, N1, N1A ... First main direction (main direction), P ... Inclination angle, W ... Chain width direction, X ... Chain travel direction, Y1, Y1A: Chain linear region, Z: Approach angle.

Claims (4)

A plurality of links lined up in the direction of travel of the chain,
A plurality of connecting members extending in a chain width direction orthogonal to the chain traveling direction and connecting a plurality of links to each other;
The connecting member includes a long power transmission member having an end surface that is in contact with the sheave surface of the pulley so that power transmission is possible
The power transmission member includes a flat rear surface extending along the chain width direction and facing a direction opposite to the chain traveling direction,
The end face is formed with a convex curved portion for forming a contact region between the end face and the pulley when the power transmission member is engaged with the pulley.
When the power transmission member is viewed from the chain width direction, the convex curved portion has a center and a main direction that satisfy the following conditions 1) and 2).
1) The direction perpendicular to the rear surface is the thickness direction of the power transmission member, and the direction along the rear surface and perpendicular to the chain width direction is the height direction of the power transmission member. The power transmission member is disposed at a position that coincides with or near both the thickness center and the height center of the power transmission member.
2) When the power transmission chain is viewed from the chain width direction, the main direction of the convex curved portion is inclined at a predetermined inclination angle with respect to the rear surface.   2. The power transmission chain according to claim 1, wherein the inclination angle is set in accordance with a magnitude of an approach angle of the power transmission member with respect to the pulley.   3. The first and second pulleys each having a pair of conical sheave surfaces facing each other, and wound around these pulleys and engaged with the sheave surfaces to transmit power. A power transmission device comprising: a power transmission chain. A plurality of links arranged in the chain traveling direction and a plurality of coupling members extending in the chain width direction orthogonal to the chain traveling direction and coupling the plurality of links to each other, the coupling member transmitting power to the sheave surface of the pulley An elongate power transmission member having an end surface that comes into contact with the power transmission member, and the power transmission member includes a flat rear surface extending in the chain width direction and facing a direction opposite to the chain traveling direction. In the method of manufacturing a power transmission chain, a convex curved portion for forming a contact region between the end face and the pulley when the power transmission member bites into the pulley is formed.
Without changing the position of the outer periphery of the power transmission member with respect to the link in the chain linear region, the power transmission member in the chain linear region can be viewed from the chain width direction according to the magnitude of the approach angle of the power transmission member with respect to the pulley. A method of manufacturing a power transmission chain, characterized in that the direction of the main direction of the convex curved portion is changed.

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