JP2008298242A - Power transmission chain and power transmission device furnished with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce noise concerning a power transmission chain. <P>SOLUTION: A first pin 3 of a connecting member 50 to connect a plurality of links to each other includes first and second kind first pins 3a, 3b. These pins 3a, 3b are arranged at random in the chain proceeding direction X. The first kind first pin 3a includes a first kind rate of change increasing part 18a where a rate of change of displacement quantity of a contact part T relatively largely increases in correspondence with increase of an angle of bend between the links. The second kind first pin 3b includes a second kind rate of change increasing part 18b where a rate of change of displacement quantity of a contact part T relatively small increases in correspondence with increase of the angle of bend between the links. When seen along the chain cross direction W, a contact central point Fa of the first kind first pin 3a matches with a center of figure Ja of an end surface 17a of the first kind first pin 3a, and a contact central point Fb of the second kind first pin 3b offsets from a center of figure Jb of an end surface 17b of the second kind first pin 3b. <P>COPYRIGHT: (C)2009,JPO&INPIT

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 includes links connected by first and second pins (for example, , See Patent Document 1).
JP 2006-242374 A

  For such a power transmission chain, further noise reduction is required. The present invention aims to solve this problem.

  In order to achieve the above object, the present invention provides a plurality of links (2) arranged in the chain traveling direction (X) and a plurality of links extending in the chain width direction (W) perpendicular to the chain traveling direction and connecting the links to each other. Each of the connecting members includes a main power transmission member (3) and a sub-power transmission member (4) having opposing portions (12, 22) opposed to each other. The opposite opposing portions of the main power transmission member and the sub power transmission member of the main power transmission member are in rolling contact with each other at a contact portion (T) that is displaced in accordance with a change in the bending angle (θ) between the links. A contact region (19) that contacts the sheave surfaces (62a, 63a, 72a, 73a) of the pulley (60, 70) is formed on the end surface (17), and this contact region includes a contact center point (F), The power transmission member is in the direction of chain travel Randomly arranged first-type main power transmission member (3a) and second-type main power transmission member (3b), the opposing portion (12) of the first-type main power transmission member is between the links It includes a first type change rate increasing portion (18a) in which the change rate of the displacement amount of the contact portion increases relatively with the increase in the bending angle, and the opposing portion of the second type main power transmission member is a link. Including a second type change rate increasing portion (18b) in which the change rate of the displacement amount of the contact portion increases relatively small as the bending angle increases, and when viewed along the chain width direction, the first type The contact center point (Fa) of the main power transmission member is arranged so as to coincide with the centroid (Ja) of the end surface (17a) of the first type main power transmission member. The contact center point (Fb) is located from the centroid (Jb) of the end surface (17b) of the second type main power transmission member. Provided is a power transmission chain (1) characterized in that it is arranged offset in a predetermined direction (V; X; Y) (Claim 1).

The alphanumeric characters in parentheses indicate corresponding components in the embodiments described later. The same applies hereinafter.
According to the present invention, the first type and the second type of main power transmission members are randomly arranged in the chain traveling direction so that the main power transmission members are engaged when the main power transmission members are sequentially engaged with the sheave surface of the pulley. As a result of the random period, the frequency of the engagement sound can be distributed over a very wide range. Thereby, a peak can be prevented from occurring at a specific frequency of the engagement sound, and the noise of the power transmission chain can be significantly reduced through the reduction of the engagement sound. In addition, with respect to the first type main power transmission member that is designed to slide relatively large when the link is bent, it contacts a position close to the instantaneous center of the rolling sliding movement when viewed from the chain width direction. A center point can be placed. As a result, the amount of sliding with the sheave surface when the first main power transmission member is engaged with the sheave surface of the pulley can be reduced, and the engagement sound can be further reduced. Furthermore, the amount of displacement of the second type main power transmission member when the link is bent is relatively small. As a result, the amount of sliding with the sheave surface when the second main power transmission member is engaged with the sheave surface of the pulley can be reduced, and the engagement sound can be further reduced.

  In the present invention, each of the first type change rate increasing portion and the second type change rate increasing portion includes an involute curve (INVa, INVb), and the first type change rate increasing portion The radius (Rba) of the base circle (Ca) related to the involute curve may be relatively large, and the radius (Rbb) of the base circle (Cb) related to the involute curve of the cross section of the second type of change rate increasing portion may be relatively small. (Claim 2).

  In this case, the locus of movement of the contact portion of the main power transmission member accompanying the bending between the links can be made to follow the involute curve. As a result, it is possible to reliably reduce the string-like vibration of the power transmission chain caused by the main power transmission member sequentially engaging with the sheave surface of the pulley. In addition, the involute curves of the cross sections of the first type and second type change rate increasing portions have a simple configuration in which the radii of the base circles are different from each other, so that the contact portion corresponding to the increase in the bending angle between the links can be obtained. The change rate of the displacement amount can be reliably varied between the first type and second type change rate increasing portions.

In the present invention, the predetermined direction when viewed along the chain width direction is the orthogonal direction (V) orthogonal to both the chain traveling direction and the chain width direction, the chain traveling direction, or the orthogonal direction and the chain traveling direction. In some cases, it includes an inclination direction (Y) that is inclined with respect to both of them.
For example, when the predetermined direction is an orthogonal direction, the position of the centroid of the end face of the second type main power transmission member and the position of the contact center point of the contact area can be matched with respect to the chain traveling direction. As a result, the second type main power transmission member can be made thin in the chain traveling direction. Further, when the predetermined direction is the chain traveling direction, the contact portion of the second type main power transmission member and the contact center point can be greatly separated with respect to the chain traveling direction. Thereby, the cycle in which the main power transmission member is engaged with the sheave surface of the pulley can be made more random, and as a result, the engagement sound when the main power transmission member is engaged with the pulley can be further reduced. Furthermore, when the predetermined direction is the tilt direction, it is possible to realize both the advantages when the predetermined direction is the orthogonal direction and the advantages when the direction is the chain traveling direction.

In the present invention, the link includes a first type link (2a) and a second type link (2b) having different connection pitches (P), and the first type link and the second type link are included. In some cases, the chains are randomly arranged in the chain traveling direction (claim 4).
The “connection pitch” refers to, for example, a pitch between adjacent connection members in a linear region of the power transmission chain.

In this case, the frequency when the main power transmission member sequentially engages with the sheave surface of the pulley can be made more random. As a result, the frequency of the engagement sound of the power transmission chain can be distributed over a wider range. Can be further reduced.
In the present invention, the first and second pulleys (60, 70) each having a pair of conical surface sheave surfaces (62a, 63a, 72a, 73a) facing each other and the pulleys are wound around these pulleys. And the power transmission chain that engages with the sheave surface and transmits power (claim 5). In this case, it is possible to realize a power transmission device with extremely low driving noise.

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 an input shaft 61 that is connected to a vehicle drive source so that power can be transmitted, and includes a fixed sheave 62 and a movable sheave 63. The fixed sheave 62 and the movable sheave 63 have a pair of sheave surfaces 62a and 63a that face each other. The sheave surfaces 62a and 63a include conical inclined surfaces.

  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 winding radius (effective radius) of the pulley 60 related to the chain 1 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. Thereby, the chain 1 is moved, and the winding radius of the pulley 70 related to the chain 1 can be changed.

FIG. 3 is a cross-sectional view of the main part of the chain 1. FIG. 4A is a cross-sectional view taken along the line IVA-IVA in FIG. 3 and shows a straight region of the chain 1. FIG. 4B is a cross-sectional view taken along the line IVB-IVB in FIG. 3 and shows a straight region of the chain 1. When describing with reference to FIG. 4 (A) and FIG. 4 (B), it demonstrates based on the linear area | region of the chain 1. FIG.
3 and 4A, chain 1 includes a plurality of links 2 and a plurality of connecting members 50 that connect these links 2 to each other.

Hereinafter, the direction parallel to the traveling direction of the chain 1 is referred to as the chain traveling direction X, and the direction parallel to the chain width direction orthogonal to the chain traveling direction X is referred to as the chain width direction W. A direction orthogonal to both of the 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.

  A plurality of link rows 51, 52, 53,... Are formed using the link 2. Each of the link rows 51, 52, 53,... Includes a plurality of links 2 arranged in the chain width direction W. The links 2 in the same link row are aligned so that the positions in the chain traveling direction X are the same. The link rows 51, 52, 53,... Are arranged along the chain traveling direction X.

The links 2 adjacent to each other in the chain traveling direction X are connected to each other by the corresponding connecting members 50, whereby the endless chain 1 is formed.
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 row 52 correspond to each other in the chain width direction W, The links 2 in the first and second rows 51 and 52 are connected to each other by a connecting member 50 inserted through the through holes 9 and 10.

Thus, the front through-hole 9 of the link 2 of one link row and the rear through-hole 10 of the link 2 of the other link row positioned in front of the chain traveling direction X with respect to the one link row, The links 2 in the corresponding link row are connected to each other by connecting members 50 that are lined up in the chain width direction W and correspond to each other.
Each connecting member 50 has a symmetrical shape in the chain width direction W, and includes a pair of first and second pins 3 and 4.

Each of the first and second pins 3 and 4 is a long member extending in the chain width direction W and formed using bearing steel such as JIS (Japanese Industrial Standard) SUJ2 material.
Referring to FIG. 4A, first pin 3 constitutes a main power transmission member. The peripheral surface 11 of the first pin 3 has a front portion 12 as a facing portion facing forward in the chain traveling direction X, a rear portion 13 facing backward in the chain traveling direction X, and a pair of ends facing each other in the orthogonal direction V One end portion 14 and the other end portion 15 as a portion.

The one end portion 14 is relatively positioned on the outer diameter side of the chain 1 (one side in the orthogonal direction V), and the other end portion 15 is relatively positioned on the inner diameter side of the chain 1 (the other side in the orthogonal direction V). Is located.
The front portion 12 includes a change rate increasing portion 18. Of the first pin 3, the change rate increasing portion 18 is in rolling contact with a rear portion 22 (to be described later) of the corresponding second pin 4 and a contact portion T as the link 2 is bent. .

The rolling sliding contact means a contact including at least one of a rolling contact and a sliding contact.
5A and 5B are partial cross-sectional views of the connecting member 50, respectively. Referring to FIG. 5A, the cross section of the change rate increasing portion 18 is composed of an involute curve INV. The starting point B of the involute curve INV coincides with the contact portion T1 of the first and second pins 3 and 4 in the linear region of the chain 1. This starting point B is close to the other end 15 of the one end 14 and the other end 15 of the front portion 12.

The involute curve INV is based on a predetermined basic circle C. The basic circle C is a circle having a center D and a radius Rb.
The center D is located on a plane E that is orthogonal to the chain traveling direction X and includes the contact portion T1 of the first pin 3 and that advances from the contact portion T1 toward the inner diameter side of the chain. A starting point B is arranged on the basic circle C.

The involute curve INV extends from the starting point B to the chain outer diameter side. The radius of curvature of the involute curve INV increases as the involute curve INV advances toward the chain outer diameter side. Thereby, according to the increase in the bending angle between the links 2, the rate of change of the displacement amount of the contact portion T increases.
With reference to FIG. 4A, the trajectory of the movement of the contact portion T accompanying the bending between the corresponding links 2 as viewed from the chain width direction W is an involute curve with the first pin 3 as a reference. It becomes. The rear portion 13 is formed on a flat surface facing the inner diameter side of the chain.

  With reference to FIG. 2, an end face 17 is provided at each of the pair of end portions 16 of the first pin 3. These end surfaces 17 engage with the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70 through a thin lubricating oil film so as to be able to transmit power. Thus, since the end face 17 of the first pin 3 directly contributes to power transmission, the first pin 3 is made of a material having high strength and excellent wear resistance, such as the above-described bearing steel. Yes.

The end surface 17 of the first pin 3 is formed in a shape including a part of a spherical surface, and is convexly curved outward in the chain width direction W. One end portion 14 of the first pin 3 protrudes outside the other end portion 15 in the chain width direction W.
With reference to FIG. 2 and FIG. 5 (A), a contact region 19 is provided on the end face 17. The contact area 19 of the end surface 17 is engaged with the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70 through a thin lubricating oil film so that power can be transmitted.

The contact area 19 has, for example, an elliptical shape, and the center of the ellipse is a contact center point F. When viewed along the chain width direction W, the long axis 20 of the contact region 19 is parallel to the rear portion 13 of the first pin 3.
Referring to FIG. 4A, the second pin 4 is also called a strip or an interpiece, and constitutes a secondary power transmission member. The second pin 4 is formed shorter than the first pin 3 so as not to contact the sheave surface of each of the pulleys, and 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 21 of the second pin 4 includes a rear portion 22 facing rearward in the chain traveling direction X. The rear portion 22 is formed on a flat surface perpendicular to the chain traveling direction X, and constitutes a facing portion that faces the front portion 12 of the corresponding first pin 3.
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 so as to be relatively movable, and the corresponding second pin 4 is press-fitted and fixed. In addition, the corresponding first pins 3 are press-fitted and fixed in the rear through-holes 10 of the links 2, and the corresponding second pins 4 are loosely fitted so as to be relatively movable.

The chain 1 has a predetermined connection pitch P. The connection pitch P refers to the pitch between adjacent connection members 50 in the linear region of the chain 1. Specifically, it refers to the distance between the contact portions T1 of the first pins 3 adjacent to each other in the chain traveling direction X in the linear region of the chain 1.
Referring to FIG. 6, in the bending region of chain 1, bending angle θ is defined as, for example, an angle formed by first plane H1 and second plane H2.

The first plane H1 includes the respective contact center points F of the pair of first pins 31 and 32 inserted into the respective through holes 9 and 10 of one link 21 and is parallel to the chain width direction W. A flat surface.
The second plane H2 is a contact center of each of the pair of first pins 32 and 33 inserted into the through holes 9 and 10 of the other links 22 adjacent to the link 21 in the chain traveling direction X. A plane including the point F and parallel to the chain width direction W is referred to.

The design range of the bending angle θ is set to 0 ° to 20 °, for example. The position of the contact portion T is displaced as the bending angle θ between the links 2 varies.
Referring to FIGS. 5A and 5B, the feature of the present embodiment is that the first pin 3 is a first type of first power transmission member as a first type of main power transmission member. The first pin 3a of the first type and the second type of the first pin 3b having different specifications are included. 1 pin 3b is at a point arranged in the chain traveling direction X at random.

  The difference between the first type first pin 3a and the second type first pin 3b is in the following two points. That is, (i) the first type change rate increasing portion 18a, which is the change rate increasing portion 18 of the first type first pin 3a, is used to change the displacement amount of the contact portion T according to the increase in the bending angle between the links. The second rate of change increasing portion 18b, which is the rate of change increasing portion 18 of the second type first pin 3b, is formed so that the rate of change increases relatively greatly. The rate of change of the displacement amount of the contact portion T increases relatively with the increase, and (ii) when the straight region of the chain 1 is viewed along the chain width direction W, the first type The contact center point Fa of the contact region 19a of the first pin 3a is arranged so as to coincide with the centroid Ja which is the centroid J of the end surface 17a of the first type first pin 3a, and the second The contact center point Fb of the contact region 19b of the first pin 3b of the seed is defined as the first pin 3 of the second type. From a centroid J of the end face 17b centroid Jb, and that are arranged offset is different in the orthogonal direction V as a predetermined direction.

More specifically, the radius Rba of the base circle Ca with respect to the involute curve INVa of the cross section of the first type change rate increasing portion 18a is relatively large, and the cross section of the second type change rate increasing portion 18b is The radius Rbb of the basic circle Cb with respect to the involute curve INVb is relatively small.
When viewed along the chain width direction W, the contact center point Fb of the contact region 19b of the second type first pin 3b is orthogonal to the centroid Jb of the end surface 17b of the second type first pin 3b. They are offset in one direction V.

The above-mentioned “place the contact center point Fa so as to coincide with the centroid Ja” means that the two substantially coincide with each other, and includes, for example, that they are shifted within the range of manufacturing error. It is a waste.
The contact region 19a of the first type of first pin 3a is arranged so as to avoid the peripheral edge (edge) of the end surface 17a of the first type of first pin 3a. Similarly, the contact region 19b of the first pin 3b of the second type is arranged avoiding the peripheral edge (edge) of the end surface 17b of the first pin 3b of the second type.

As described above, the first-type first pins 3a and the second-type first pins 3b are randomly arranged in the chain traveling direction X.
In this case, “randomly arranged” means that at least one of the first type of first pins 3a and the second type of first pins 3b is irregular in at least a partial region of the chain traveling direction X. It means that it is arranged. “Irregular” means that there is no periodicity and / or regularity.

The first-type first pins 3a and the second-type first pins 3b may be randomly arranged over the entire region in the chain traveling direction X.
As an example of the random arrangement, the first type first pin 3a and the second type first pin 3b with respect to the chain traveling direction X include 3b, 3a, 3a, 3b, 3a, 3a, 3a, 3b. , 3a, 3a, 3a, 3a, 3a, 3b, 3a, 3a, 3a, 3a, 3a, 3a, 3a,.

Referring to FIGS. 4A and 4B, as another feature of the present embodiment, link 2 includes first type link 2a and second type link 2b having different connection pitches. It can be mentioned that the first type link 2a and the second type link 2b are randomly arranged in the chain traveling direction X.
The connection pitch Pa of the first type link 2a is relatively short, and the connection pitch Pb of the second type link 2b is relatively long. The width of the column portion 8a of the first type link 2a is relatively narrow, and the width of the column portion 8b of the second type link 2b is relatively wide.

“Randomly arranged” in this case means that at least one of the first type link 2a and the second type link 2b is irregularly arranged in at least a partial region in the chain traveling direction X. To do. “Irregular” means that there is no periodicity and / or regularity.
The first type link 2a and the second type link 2b may be randomly arranged over the entire region in the chain traveling direction X.

As an example of a random arrangement, with respect to the chain traveling direction X, the first type link 2a and the second type link 2b are 2b, 2a, 2a, 2b, 2a, 2a, 2a, 2b, 2a, 2a, 2a. , 2a, 2a, 2b, 2a, 2a, 2a, 2a, 2a, 2a, 2a,.
Referring to FIG. 1, in this continuously variable transmission 100, the drive pulley 60 rotates as the input shaft 61 rotates, whereby the chain 1 is driven, and the first pin is connected to each pulley 60, 70 is bitten.

  As described above, according to the present embodiment, the first pin 3a and the second pin 1b of the second type are randomly arranged in the chain traveling direction X, so that the first pin As a result of the random engagement cycle when 3 is sequentially engaged with the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70, the frequency of the engagement sound can be distributed over a very wide range.

  Thereby, a peak can be prevented from occurring at a specific frequency of the engagement sound, and the noise of the chain 1 can be significantly reduced through the reduction of the engagement sound. Further, when viewed from the chain width direction W, the contact center point Fa of the first type of first pin 3a is made to coincide with the centroid Ja of the end surface 17a of the first type of first pin 3a. As a result, the first pin 3a of the first type that is relatively large to slide when the link 2 is bent is centered at the moment of the rolling sliding motion when viewed from the chain width direction W. The contact center point Fa can be arranged at a close position. As a result, the sliding amount with the sheave surfaces 62a, 63a, 72a, 73a when the first type first pin 3a engages with the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70. And the engagement sound can be further reduced.

  Furthermore, the second type of first pin 3b is bent between the links 2 because the change rate of the displacement amount of the contact portion T according to the increase in the bending angle θ between the links 2 is relatively small. The amount of displacement at this time is relatively small. As a result, the amount of sliding with the sheave surfaces 62a, 63a, 72a, 73a when the first pin 3b of the second type is engaged with the sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70 is reduced. The engagement sound can be further reduced.

  Further, since the cross section of the change rate increasing portion 18 of the first pin 3 is an involute curve INV, the trajectory of the movement of the contact portion T of the first pin 3 due to the bending between the links 2 can be represented by the involute curve INV. Can be along. As a result, it is possible to reliably reduce the string-like vibration of the chain 1 due to the first pin 3 being sequentially engaged with the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70. .

  Further, with respect to the involute curves INVa and INVb of the cross sections of the first type change rate increasing portion 18a and the second type change rate increasing portion 18b, the radii Rba and Rbb of the basic circles Ca and Cb are made different from each other. With the configuration, the change rate of the displacement amount of the contact portion T according to the increase in the bending angle θ between the links 2 can be reliably made different between the first type and second type change rate increasing portions 18a and 18b. .

  Further, when viewed along the chain width direction W, the contact center point Fb of the second type of the first pin 3b is set in the orthogonal direction V from the centroid Jb of the end surface 17b of the second type of the first pin 3b. Offset to one side. Thereby, with respect to the chain traveling direction X, the position of the centroid Jb of the end face 17b of the first pin 3b of the second type can be matched with the position of the contact center point Fb. As a result, the second type first pin 3b can be made thin with respect to the chain traveling direction X.

  Further, the first pin 2 and the second link 2b having different connection pitches P are randomly arranged in the chain traveling direction X, so that the first pin 3 corresponds to each of the pulleys 60 and 70. The cycle when sequentially engaging the sheave surfaces 62a, 63a, 72a, 73a can be made more random. As a result, the frequency of the engagement sound of the chain 1 can be distributed over a wider range, and the engagement sound can be further reduced.

Further, the first pin 3 is loosely fitted into the front through hole 9 of each link 2 and the second pin 4 is press-fitted and fixed, and the first pin 3 is press-fitted and fixed to the rear through hole 10 of each link 2. In addition, the second pin 4 is loosely fitted.
Thereby, when the contact area 19 of each first pin 3 contacts the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70, the second pins 4 that make a pair are The links 2 are bent while being in rolling contact with the pin 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 extremely small. As a result, the contact region 19 of each first pin 3 is The sheave surfaces 62a, 63a, 72a, and 73a come into contact with little rotation, thereby reducing friction loss and ensuring high transmission efficiency.
Furthermore, if two types of pins (first type first pin 3a and second type first pin 3b) are used as the first pin 3, a sufficient noise reduction effect can be obtained. 3 can be reduced in number of pins.

  For example, when four types of pins are randomly arranged in the direction of chain movement: two types of pins with different cross-sectional shapes at the rate of change increase and two types of pins with different positions of the contact center point with respect to the centroid of the end face However, in this case, the number of types of pins constituting the first pin is as many as four, the number of parts is increased, and the arrangement of pins when assembling the chain is increased. The labor is increased and the manufacturing cost is increased.

On the other hand, according to the present embodiment, the number of types of pins constituting the first pin 3 can be reduced to two types, the number of parts can be reduced, and the effort of arranging the pins when assembling the chain 1 can be reduced. The manufacturing cost can be reduced.
Depending on the above, it is possible to realize a continuously variable transmission 100 that has extremely low driving noise, little vibration, excellent transmission efficiency, is easy to assemble with a small number of parts, and is inexpensive.

The present invention is not limited to the contents of the above-described embodiment, and various modifications can be made within the scope of the claims.
For example, as shown in FIG. 7, when viewed from the chain width direction W, the contact center point Fb of the contact region 19b of the second type first pin 3b is set to the end surface 17b of the second type first pin 3b. You may arrange | position offset from the centroid Jb in the chain advancing direction X. For example, the contact center point Fb is arranged behind the centroid Jb in the chain traveling direction X.

  In this case, with respect to the chain traveling direction X, the contact portion T of the second type first pin 3b and the contact center point Fb can be greatly separated. As a result, the period in which the first pin 3 engages with the sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70 can be made more random. As a result, the first pin 3 is attached to the pulleys 60, 70. The engagement noise when engaging can be further reduced.

Further, as shown in FIG. 8, when viewed from the chain width direction W, the contact center point Fb of the contact region 19b of the second type first pin 3b is set to the end surface 17b of the second type first pin 3b. You may arrange | position offset from the centroid Jb to the predetermined inclination direction Y. FIG. When viewed from the chain width direction W, the inclined direction Y is a direction inclined with respect to both the orthogonal direction V and the chain traveling direction X.
In this case, the contact center point Fb is offset from the centroid Jb in the orthogonal direction V (the advantage that the first pin 3b of the second type can be made thin), and the contact center point Fb is shown in the above diagram. It is possible to realize both of the advantages (the advantage that the engagement sound can be further reduced) when offset from the center Jb in the chain traveling direction X.

  Moreover, in each said embodiment, the cross section of the change rate increase part 18 of the 1st pin 3 may be curves other than an involute curve. The cross section of the change rate increasing portion 18 of the first pin 3 may be such that the radius of curvature of the portion forming the contact portion T increases as the bending angle θ increases. It can be constituted by a curve in which the radius of curvature increases continuously or stepwise as it goes on.

Further, the link 2 may be configured using only the first type link 2a or the second type link 2b.
Further, the first pin 3 may be loosely fitted in the corresponding rear through hole 10 of the link 2. Further, the second pins 4 may be loosely fitted in the corresponding front through holes 9 of the links 2. Further, the second pin 4 may be engaged with the pulleys 60 and 70.

Furthermore, the present invention can be applied to a so-called block type chain that includes a power transmission block that is fixed to a pin or the like 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 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). .

It is a perspective view showing typically the principal part composition of the continuously variable transmission as a power transmission device 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 sectional drawing of the principal part of a chain. (A) is sectional drawing which follows the IVA-IVA line | wire of FIG. 3, and has shown the linear area | region of a chain, (B) is sectional drawing in alignment with the IVB-IVB line | wire of FIG. Indicates the area. FIGS. 5A and 5B are partial cross-sectional views of the connecting member. It is a side view of the bending area | region of a chain. It is a side view 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.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Power transmission chain, 2 ... Link, 2a ... 1st type link, 2b ... 2nd type link, 3 ... 1st pin (main power transmission member), 3a ... 1st type 1st pin ( 1st type main power transmission member), 3b ... 2nd type 1st pin (2nd type main power transmission member), 4 ... 2nd pin (sub power transmission member), 12 ... front (main) (Opposite portion of the power transmission member), 17 ... end face (of the first pin), 17a ... end face (of the first type of first pin), 17b ... end face (of the second type of first pin), 18a ... 1st type change rate increasing part, 18b ... 2nd type change rate increasing part, 19 ... Contact area, 22 ... Rear part (opposite part of auxiliary power transmission member), 50 ... Connecting member, 60 ... Drive pulley (1st) 1 pulley), 62a, 63a ... sheave surface, 70 ... driven pulley (second pulley), 72a, 73a ... sheave surface, 100 ... steplessly Speed machine (power transmission device), Ca ... foundation circle, Cb ... foundation circle, F ... contact center point (of the first pin), Fa ... contact center point (of the first pin of the first type), Fb ... Contact center point (of the second type of first pin), INVa (in the first type of change rate increasing portion) involute curve, INVb (in the second type of change rate increasing portion) of the involute curve, Ja ... ( Centroid of the first type first pin), Jb ... (end type of the first pin end face) centroid, P ... connection pitch, Rba ... (first type change rate increasing portion) Radius of the base circle with respect to the involute curve of the cross section, Rbb ... Radius (of the base circle with respect to the involute curve of the cross section of the second type of change rate increasing portion), T ... Contact portion, V ... The orthogonal direction (predetermined direction) ... Chain width direction, X ... Chain travel direction (predetermined direction), Y ... Inclination direction (predetermined direction) ), Θ ... bending angle.

Claims (5)

A plurality of links arranged in the chain traveling direction, and a plurality of connecting members that extend in the chain width direction orthogonal to the chain traveling direction and connect the links to each other;
Each of the connecting members includes a main power transmission member and a sub power transmission member having opposing portions facing each other,
The opposing facing portions of the main power transmission member and the sub power transmission member of each of the connecting members are in rolling contact with each other at a contact portion that is displaced with a change in the bending angle between the links,
A contact region that contacts the sheave surface of the pulley is formed on an end surface of the main power transmission member, and the contact region includes a contact center point,
The main power transmission member includes a first type main power transmission member and a second type main power transmission member randomly arranged in the chain traveling direction,
The facing portion of the first type main power transmission member includes a first type change rate increasing portion in which the change rate of the displacement amount of the contact portion increases relatively greatly as the bending angle between the links increases. The opposing portions of the two types of main power transmission members include a second type rate-of-change increasing portion in which the rate of change of the displacement amount of the contact portion increases relatively small as the bending angle between the links increases.
When viewed along the chain width direction, the contact center point of the first type main power transmission member is arranged so as to coincide with the centroid of the end surface of the first type main power transmission member, and the second type main power transmission member A power transmission chain, wherein the contact center point of the transmission member is arranged offset in a predetermined direction from the centroid of the end face of the second type main power transmission member. The cross section of each of the first type change rate increasing portion and the second type change rate increasing portion according to claim 1 includes an involute curve,
A power transmission chain in which the radius of the base circle with respect to the involute curve of the cross section of the first type change rate increasing portion is relatively large and the radius of the base circle with respect to the involute curve of the cross section of the second type change rate increasing portion is relatively small .   3. The predetermined direction when viewed along the chain width direction according to claim 1, wherein the predetermined direction is an orthogonal direction orthogonal to both the chain traveling direction and the chain width direction, the chain traveling direction, or both the orthogonal direction and the chain traveling direction. A power transmission chain that includes an inclination direction that is inclined with respect to the axis. The link according to any one of claims 1 to 3, wherein the link includes a first type link and a second type link having different connection pitches,
A power transmission chain in which a first type link and a second type link are randomly arranged in a chain traveling direction.   5. 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 the power transmission chain according to claim 1.

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