JP4761113B2 - Power transmission chain and power transmission device including the same - Google Patents

Description

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

For example, in an endless power transmission chain used in a power transmission device such as a pulley-type continuously variable transmission (CVT) of an automobile, pins adjacent to each other in the chain traveling direction can be moved by rolling. In addition, there are those connected by an interpiece (for example, see Patent Document 1).
In conjunction with the bending of the adjacent links, the corresponding pins and the interpieces roll with each other, and the contact positions of the corresponding pins and the interpieces move.
Japanese Patent Laid-Open No. 8-31725

The side surface of the pin is formed into a curved surface and is in line contact with the interpiece along the longitudinal direction of the pin. Therefore, when the power transmission chain is viewed from the side, the pin and the interpiece are in point contact. As a result, the pin and the interpiece smoothly roll and the link is smoothly bent.
However, in the linear region of the chain, neither the pin nor the interpiece is engaged with the pulley (not pinched), so the pin and the interpiece cause an inadvertent rolling motion due to the inertia of the chain drive, etc. Tend to bend carelessly.

Inadvertent bending between the links causes vibration of the power transmission chain, which is not preferable. In addition, the links are bent from the straight state in the direction opposite to the original bending direction (negative side), so-called overshoot, which is not preferable in terms of improving the transmission efficiency.
A similar problem exists not only in a power transmission chain including pins and strips but also in a power transmission chain having another general configuration.

  The present invention has been made under such a background, and an object of the present invention is to provide a power transmission chain capable of suppressing vibration and improving transmission efficiency, and a power transmission device including the power transmission chain. .

In order to achieve the above object, the present invention provides a power transmission chain (1) comprising a plurality of links (2, 2B) and a plurality of connecting members (3, 3A) for connecting these links so as to bend each other. Each of the connecting members is a predetermined power transmission member (3, 3) that is in rolling contact with the pair of members (4) interposed between the link and the link, in association with the bending between the links. 3A), and the movement trajectory of the contact point (T; TA) as seen from the chain width direction (W) between the predetermined power transmission member and the mating member accompanying bending between the links is a predetermined starting point (J: JA). ), And the opposing portion (12; 12A) of the predetermined power transmission member with respect to the even member is a curved surface portion (25;) for achieving the predetermined curve as a movement locus of the contact point. 25A) and the song An extended portion (26) extending in the opposite direction (V1) from the curved surface portion from the starting point of the curved portion, and the opposing portion of the predetermined power transmission member in the linear region of the power transmission chain is the starting point of the curved surface portion and the extending portion. Ri Citea into contact with even number members in portions, opposite portions of the kinematic pair members for the predetermined power transmission member (19; 31) is a flat surface, the extension of the above-mentioned power transmission member, a flat surface, almost the entire extension of the above-mentioned power transmission member is characterized that you have contacted the facing portion and the surface of the kinematic pair members in the chain linear region.

In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.
According to the present invention, the power transmission member in the linear region is restrained from moving in the reverse direction with respect to the pair member. As a result, it is possible to suppress a so-called overshoot in which the links in the straight region are inadvertently bent in the direction opposite to the original bending direction (negative side). Therefore, for example, when the power transmission chain is wound around a pair of pulleys and the power transmission member engages with each pulley to transmit power, the links in the linear region not held by the pulleys overshoot. To suppress vibration and noise of the power transmission chain. Further, by suppressing the overshoot, it is possible to suppress an excessive load from acting on the power transmission chain and achieve high transmission efficiency.

The rolling sliding contact means a contact including at least one of a rolling contact and a sliding contact. Further, the reverse direction refers to, for example, one of the directions orthogonal to both the chain traveling direction and the chain width direction.
Moreover , it can prevent more reliably that the power transmission member of a linear area | region moves to a reverse direction with respect to a pair member by the surface contact of the said extension part and the said pair member.

  In the present invention, the plurality of links include first and second through holes (9, 10; 9B, 10B) arranged in the chain traveling direction (X), respectively, and the predetermined power transmission member includes A power transmission member (3, 3A) that can be fitted into one through hole so as to be relatively movable, and a power transmission member (3, 3A) that can be fitted into the second through hole with relative movement restricted There is. In this case, the power transmission member and the corresponding link can be reliably connected, and the effect of the power transmission member that suppresses inadvertent bending of the links can be reliably exhibited.

  In the present invention, the predetermined power transmission member may include a plurality of types of power transmission members (3, 3A) having different movement loci of rolling and sliding contact with the pair member. In this case, for example, when the power transmission chain is wound around a pair of pulleys and the power transmission member engages with each pulley to transmit power, and each power transmission member sequentially engages with the pulley. The generation cycle of the engagement sound can be made random. Thereby, the frequency of the said engagement sound can be distributed over a wide range, and the noise accompanying the drive of a power transmission chain can be reduced more.

  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 above power transmission chain that transmits power in contact with the sheave surface. In this case, it is possible to realize a power transmission device that is suppressed in vibration, excellent in quietness, and excellent in transmission efficiency.

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

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

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

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

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

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

4 and 5, the chain 1 includes a plurality of links 2 and a plurality of pairs of first and second pins 3 and 4 that connect the links 2 so as to be bendable to each other. The first pin 3 rolls and comes into sliding contact with the second pin 4 forming a pair 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.

Hereinafter, a direction along the traveling direction of the chain 1 is referred to as a chain traveling direction X, and a direction perpendicular to the chain traveling direction X and along the longitudinal direction of the first and second pins 3 and 4 is defined as the chain width direction W. A direction perpendicular to both the chain traveling direction X and the chain width direction 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. The peripheral edge of each link 2 is formed in a smooth curve and has a shape in which stress concentration hardly occurs.

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

The links 2 of the first to third link rows 51 to 53 are respectively connected to the links 2 of the corresponding first to third link rows 51 to 53 using the corresponding first and second pins 3 and 4. It is connected to be relatively rotatable (bendable).
Specifically, the front through-hole 9 of the link 2 of the first link row 51 and the rear through-hole 10 of the link 2 of the second link row 52 correspond to each other side by side in the chain width direction W. The links 2 of the first and second link rows 51 and 52 are connected to be able to bend in the chain traveling direction X by the first and second pins 3 and 4 that pass through the through holes 9 and 10. Yes.

Similarly, the front through-hole 9 of the link 2 of the second link row 52 and the rear through-hole 10 of the link 2 of the third link row 53 correspond to each other along the chain width direction W. The links 2 of the second and third link rows 52 and 53 are connected to be able to be bent in the chain traveling direction X by the first and second pins 3 and 4 inserted through the through holes 9 and 10.
In FIG. 4, only one each of the first to third link rows 51 to 53 is illustrated, but the first to third link rows 51 to 53 are repeated along the chain traveling direction X. Has been. The links 2 in the two link rows adjacent to each other in the chain traveling direction X are sequentially connected by the corresponding first and second pins 3 and 4 to form an endless chain 1.

4 and 5, the first pin 3 is a predetermined power transmission member as a long (plate-like) connecting member extending in the chain width direction W. The peripheral surface 11 of the first pin 3 extends in parallel to the chain width direction W.
The peripheral surface 11 is formed as a smooth surface, and includes a front portion 12 as a facing portion facing forward in the chain traveling direction X, a rear portion 13 as a back portion facing backward in the chain traveling direction X, and an orthogonal direction V. One end 14 and the other end 15 as a pair of opposite ends.

The front portion 12 faces the paired second pins 4 and comes into rolling contact with a rear portion 19 (to be described later) of the second pins 4 at a contact portion T (contact point as viewed from the chain width direction W). ing.
The rear portion 13 is formed on a flat surface. This flat surface has a predetermined inclination angle B with respect to a predetermined plane A orthogonal to the chain traveling direction X (a plane orthogonal to the paper surface in FIG. 5), and faces the inner peripheral side of the chain. .

The one end portion 14 constitutes an end portion on the chain outer peripheral side (one in the orthogonal direction V) of the peripheral surface 11 of the first pin 3 and is formed in a curved surface that is convexly curved toward the chain outer peripheral side. Yes.
The other end portion 15 constitutes an end portion on the chain inner peripheral side (the other in the orthogonal direction V) of the peripheral surface 11 of the first pin 3, and has a curved surface that is convexly curved toward the inner peripheral side of the chain. Is formed.
In the following, in the orthogonal direction V, a side from the one end portion 14 toward the other end portion 15 is referred to as a chain inner peripheral side, and a side from the other end portion 15 toward the one end portion 14 is referred to as a chain outer peripheral side.

The pair of end portions 16 in the longitudinal direction (chain width direction W) of the first pin 3 protrudes in the chain width direction W from the links 2 arranged at the pair of end portions in the chain width direction W, respectively. The pair of end portions 16 are respectively provided with end surfaces 17 as a pair of power transmission portions.
2 and 6, the pair of end faces 17 are opposed to each other across a plane orthogonal to the chain width direction W, and have a symmetrical shape. These end surfaces 17 are for frictional contact (engagement) with the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70.

The first pin 3 is sandwiched between the corresponding sheave surfaces 62a, 63a, 72a, 73a, whereby power is transmitted between the first pin 3 and the pulleys 60, 70. Since the end surface 17 of the first pin 3 directly contributes to power transmission, the first pin 3 is formed of a high-strength wear-resistant material such as bearing steel (SUJ2), for example.
The end surface 17 of the first pin 3 is formed in a shape including a part of the spherical surface, and is convexly curved outward in the chain width direction W. The one end portion 14 of the first pin 3 is formed longer (wider) in the chain width direction W than the other end portion 15, whereby the end surface 17 faces the inner circumferential side of the chain. When viewed from the chain width direction W, the position of the top 23 of the end face 17 coincides with the position of the centroid of the end face 17.

A contact region 24 is provided on the end surface 17. The contact area 24 of the end surface 17 comes into contact with the corresponding sheave surfaces 62a, 63a, 72a, 73a of the pulleys 60, 70.
The contact region 24 has, for example, an elliptical shape, and has a contact center point C (corresponding to the centroid of the contact region 24). When viewed from the chain width direction W, the position of the contact center point C coincides with the position of the top 23 (the position of the centroid of the end face 17). The position of the contact center point C may be shifted (offset) from the centroid of the end surface 17.

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

When viewed along the chain width direction W, the major axis D of the contact region 24 is a predetermined angle of attack E (for example, 5 to 12 ° with respect to the plane A described above. In the present embodiment, 10 ° )), And proceeds in the chain traveling direction X side from the outer peripheral side of the chain toward the inner peripheral side.
The angle of attack E is, for example, equal to the inclination angle B of the rear portion 13 of the first pin 3 (E = B). The angle of attack E and the inclination angle B may be different.

4 and 5, the second pin 4 (also referred to as a strip or an interpiece) is a long plate (made of a material similar to that of the first pin 3) extending in the chain width direction W. And a pair member as a member interposed between the corresponding first pin 3 and the corresponding link 2.
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. With respect to the chain traveling direction X, the second pin 4 is formed thinner than the first pin 3.

The peripheral surface 18 of the second pin 4 extends in the chain width direction W. The peripheral surface 18 is formed as a smooth surface, and includes a rear portion 19 as a facing portion facing backward in the chain traveling direction X, a front portion 20 facing forward in the chain traveling direction X, and a pair of orthogonal directions V. It has one end 21 and the other end 22 as end portions.
The rear portion 19 is formed on a flat surface orthogonal to the chain traveling direction X. As described above, the rear portion 19 faces the front portion 12 of the paired first pins 3.

The front portion 20 is formed on a flat surface substantially parallel to the rear portion 19.
The one end portion 21 constitutes an end portion on the chain outer peripheral side of the peripheral surface 18 of the second pin 4 and is formed in a curved surface that is convexly curved toward the chain outer peripheral side.
The other end portion 22 constitutes an end portion on the inner circumferential side of the peripheral surface 18 of the second pin 4 and is formed in a curved surface that is convexly curved toward the inner circumferential side of the chain.

  The chain 1 is a so-called press-fit type chain. Specifically, the first pin 3 is loosely fitted in the front through hole 9 of each link 2 so as to be relatively movable, and the relative movement is regulated by the rear through hole 10 of each link 2. The second pin 4 is press-fitted and press-fitted so that the relative movement of the second pin 4 is restricted to the front through-hole 9 of each link 2 and can be relatively moved to the rear through-hole 10 of each link 2. Are loosely fitted.

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

With the above-described configuration, the rear portion 19 of the second pin 4 paired with the front portion 12 of the first pin 3 rolls in sliding contact with each other as the link 2 adjacent to the chain traveling direction X is bent. To do.
As shown in FIG. 5, the chain 1 has a predetermined connection pitch P. The connection pitch P refers to the distance between the adjacent first pins 3 in the linear region of the chain 1. Specifically, the mutual contact portion T1 of the first and second pins 3 and 4 in the front through-hole 9 of the link 2 in the linear region of the chain 1 and the first in the rear through-hole 10 of the link 2. And the distance in the chain traveling direction X between the contact portions T1 of the second pins 3 and 4. In the present embodiment, the connection pitch P is set to 8 mm, for example.

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

The second plane H2 is the contact center of each of the pair of first pins 3b and 3c inserted into the through holes 9 and 10 of the other link 2b adjacent to the link 2a and the chain traveling direction X. A plane including the point C and parallel to the chain width direction W is referred to.
The range of the design bending angle φ (allowable bending angle) is set to 0 ° to 20 °, for example.
FIG. 7 is an enlarged cross-sectional view of the main part of the first pin 3. With reference to FIGS. 5 and 7, the feature of the present embodiment is that the links 2 in the linear region of the chain 1 are in the original bending direction while achieving smooth bending between the adjacent links 2. Inadvertent bending (hereinafter referred to as overshoot) in the opposite direction (the negative side of the bending angle φ).

Specifically, a curved surface portion 25 and an extending portion 26 are provided on the front portion 12 of the first pin 3. The curved surface portion 25 and the extending portion 26 are arranged in the orthogonal direction V.
An end of the curved surface portion 25 on the inner peripheral side of the chain is a predetermined starting portion J (predetermined starting point when viewed from the chain width direction W). The position of the raised portion J coincides with the position of the contact portion T1, that is, the contact portion T of the first pin 3 in the linear region of the chain 1. The raised portion J is disposed closer to the inner circumferential side of the front portion 12.

When viewed from the chain width direction W, the curved surface portion 25 is composed of an involute curve as a predetermined curve having a predetermined starting portion J (starting point). The basic circle K of the involute curve is a circle having a center M and a radius Rb (basic circle radius, for example, 100 mm).
The center M is positioned on the chain inner peripheral side with respect to the contact portion T1 on a plane orthogonal to the chain traveling direction X and including the contact portion T1 of the first pin 3. The base circle K and the starting part J intersect.

With the above configuration, the curved surface portion 25 is in contact with the rear portion 19 of the pair of second pins 4 at the contact portion T when viewed from the chain width direction W. The movement trajectory of the contact portion T accompanying the bending between the corresponding links 2 forms an involute curve having a starting portion J with respect to the first pin 3.
That is, when viewed from the chain width direction W, the curved surface portion 25 of the first pin 3 is formed in an involute curve, so that the movement trajectory of the contact portion T has the above-described involute curve. The contact portion T is displaced toward the outer periphery of the chain as the bending angle φ (see FIG. 6) between the corresponding links 2 increases.

In addition, you may form the curved surface part 25 of the 1st pin 3 seen from the chain width direction W in curves (for example, the curve which has a single or several curvature radius) other than an involute curve.
Referring to FIGS. 5 and 7 again, the extending portion 26 is for suppressing the adjacent links 2 in the linear region from overshooting. The extended portion 26 constitutes a portion of the front portion 12 that is closer to the inner circumference side of the chain than the curved surface portion 25, and is opposite to the curved portion 25 from the rising portion J of the curved surface portion 25 (the inner circumference side of the chain). Direction).

The extending portion 26 is formed of a flat surface orthogonal to the chain traveling direction X, and extends along the orthogonal direction V when viewed from the chain width direction W. In the linear region of the chain 1, the extended portion 26 and the rear portion 19 of the second pin 4 face each other in parallel, and the substantially entire surface of the extended portion 26 is in surface contact with the rear portion 19.
Accordingly, when the straight region of the chain 1 is viewed from the chain width direction W, the front portion 12 of the first pin 3 is in contact with the rear portion 19 of the raised portion J of the curved surface portion 25 and the extending portion 26.

The length N of the extending portion 26 in the orthogonal direction V is preferably in the range of 0.05 mm to 0.8 mm (for example, 0.8 mm in the present embodiment). If the length N is less than 0.05 mm, it will be difficult to secure a sufficient area of the extended portion 26, and if the length N exceeds 0.8 mm, the extended portion 26 will be too large. This is because the size of the pin 3 of 1 is increased.
The lower limit of the length N range is more preferably 0.1 mm. The upper limit of the length N range is preferably 0.8 mm, but may be larger.

  The above is the schematic configuration of the continuously variable transmission 100 (see FIG. 3A). When the continuously variable transmission 100 is driven, the chain 1 is rotationally driven to transmit power to each of the drive pulley 60 and the driven pulley 70. At this time, as shown in FIG. 5, in the straight region of the chain 1, the front portion 12 of the first pin 3 is the second pin 4 paired with the raised portion J (contact portion T) of the curved surface portion 25. While being in line contact with the rear portion 19, the extended portion 26 is in surface contact with the rear portion 19.

As a result, in the straight region of the chain 1, the first pin 3 is suppressed from rolling and sliding in the reverse direction V1 with respect to the corresponding second pin 4, and as a result, overshoot is suppressed. .
On the other hand, as shown in FIG. 6, in the bent region of the chain 1, the front portion 12 of the first pin 3 is lined with the rear portion 19 of the second pin 4 whose contact portion T of the curved surface portion 25 makes a pair. Contact. At this time, the extending portion 26 and the rear portion 19 are not in contact with each other.

Thereby, in the bending region of the chain 1, the paired first and second pins 3 and 4 are smoothly rolled and slidably contacted, and the chain 1 is moved from the straight region to the bending region having a predetermined bending angle φ. Transition smoothly.
As described above, according to the present embodiment, the first pin 3 in the linear region of the chain 1 is suppressed from moving in the reverse direction V1 with respect to the corresponding second pin 4. .

As a result, overshooting of the links 2 in the linear region of the chain 1 can be suppressed. Therefore, it is possible to suppress overshooting of the links 2 in the linear region of the chain 1 that are not held by any of the pulleys 60 and 70, and vibration and noise of the chain 1 can be suppressed.
Further, by suppressing the overshoot, it is possible to suppress an extra load from acting on the chain 1 and to achieve high transmission efficiency.

Further, in the linear region of the chain 1, the extended portion 26 of the first pin 3 is in surface contact with the rear portion 19 of the corresponding second pin 4, so that the first pin 3 corresponds to the corresponding second pin 4. It is possible to more reliably prevent the movement in the reverse direction V1.
In addition, by being in surface contact, it is possible to sufficiently secure the mutual contact area of the paired first and second pins 3 and 4 and further reduce the pressure (surface pressure) at the time of contact between them. it can. Therefore, the load received by each of the first and second pins 3 and 4 can be reduced, and the durability of the chain 1 can be further improved.

In addition, since each first pin 3 is press-fitted into the corresponding rear through hole 10 of the corresponding link 2, the corresponding link 2 can be reliably connected to each corresponding first pin 3. Thereby, the effect which suppresses the careless bending of the links 2 which the extension part 26 of the 1st pin 3 has can be exhibited reliably.
Further, the first pin 3 is loosely fitted into the front through hole 9 of each link 2 and is press-fitted into the rear through hole 10 of each link 2. Further, the second pin 4 is fitted to the front through hole of each link 2. The link 9 is press-fitted and fitted into the rear through-hole 10 of each link 2.

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

Further, the trajectory of the contact portion T with respect to the first pin 3 draws an involute curve when viewed from the chain width direction W. Thereby, when each 1st pin 3 is sequentially bitten by each pulley 60 and 70, it can suppress that a string vibration-like motion arises in the chain 1. FIG. As a result, noise during driving of the chain 1 can be further reduced.
In this way, it is possible to realize a continuously variable transmission 100 that is suppressed in vibration, excellent in quietness, and excellent in transmission efficiency and durability.

FIG. 8 is a partial sectional view of an essential part of still another embodiment of the present invention. In the present embodiment, differences from the embodiment shown in FIGS. 1 to 7 are mainly described, and the same components are denoted by the same reference numerals and the description thereof is omitted.
Referring to FIG. 8, the feature of the present embodiment is that first pins 3 and 3A are provided as a plurality of types of first pins, and the first pin 3 is used as a reference. The moving locus of the rolling sliding contact of the contact portion T is different from the moving locus of the rolling sliding contact of the contact portion TA with reference to the first pin 3A.

  Specifically, the cross-sectional shape (the shape viewed from the chain width direction W) of the front portion 12A of the first pin 3A is different from the cross-sectional shape of the front portion 12 of the first pin 3. When the straight region of the chain 1 is viewed from the chain width direction W, the radius RbA of the basic circle KA of the curved surface portion 25A of the first pin 3A is different from the radius Rb of the basic circle K of the curved surface portion 25 of the first pin 3 (RbA ≠ Rb). In this embodiment, RbA <Rb. Thereby, the curved surface portion 25 </ b> A is curved larger than the curved surface portion 25.

Note that the shape of the curved surface portion 25A of the first pin 3A viewed from the chain width direction W may be a curve other than the involute curve (for example, a curve having a single or a plurality of curvature radii).
When the straight region of the chain 1 is viewed from the chain width direction W, the contact portion T of the first pin 3 and the contact portion TA of the first pin 3A are aligned in the orthogonal direction V. That is, these contact portions T and TA are arranged on a straight line extending in the chain traveling direction X.

In addition, although these contact parts T and TA may be arrange | positioned so that the position of the orthogonal direction V may shift | deviate (offset), it is preferable that it arranges like this Embodiment. This is because if the offset is performed as described above, an unnecessary moment is generated to roll the first pins 3 and 3A in the linear region of the chain 1 with respect to the corresponding second pins 4.
The first pins 3 and the first pins 3A are randomly arranged in the chain traveling direction X. More specifically, at least one of the first pin 3 and the first pin 3A is irregularly arranged in at least a part of the chain traveling direction X.

According to this embodiment, the frequency of the engagement sound can be distributed over a wide range by randomizing the generation period of the engagement sound when the first pins 3 and 3A are sequentially engaged with the pulleys. Noise during driving can be further reduced.
In the present embodiment, the contact portions T and TA may be arranged offset in the orthogonal direction V. In this case, the locus of the rolling sliding contact between the contact portions T and TA can be made greatly different without increasing the size of the first pins 3 and 3A. The generation cycle of the engagement sound when the first pins 3 and 3A are sequentially engaged with the pulleys can be made more random, and the noise during driving can be further reduced.

  At this time, as described above, a moment is generated to roll the first pins 3 and 3A in the linear region of the chain 1 with respect to the corresponding second pins 4, but in the linear region of the chain 1 Since the first and second pins 3 and 4 are brought into surface contact with each other to ensure a sufficient contact area, the above moment can be sufficiently received, and the inadvertent relative motion of both can be well suppressed. .

FIG. 9 is a partial sectional view of an essential part of still another embodiment of the present invention. In the present embodiment, differences from the embodiment shown in FIGS. 1 to 7 are mainly described, and the same components are denoted by the same reference numerals and the description thereof is omitted.
Referring to FIG. 9, the feature of the present embodiment is that one (single) first pin 3 causes the links 2 </ b> B as the even members adjacent to each other in the chain traveling direction X to rotate relative to each other. It is in a point where it is connected (possibly bendable). Specifically, the corresponding first pin 3 is loosely fitted in the front through hole 9B of each link 2B so as to be relatively movable, and the corresponding first pin 3 is relative to the rear through hole 10B of each link 2B. It is press-fitted so that movement is restricted.

A front portion 31 (opposing portion) of the peripheral portion 30 of the front through-hole 9 </ b> B with respect to the chain traveling direction X has a cross-sectional shape extending in the orthogonal direction V. The front portion 31 faces the front portion 12 of the first pin 3 loosely fitted in the front through hole 9B. The contact portion T of the curved surface portion 25 of the first pin 3 is in rolling contact with the front portion 31.
As a result, the link 2B and the first pin 3 loosely fitted to the link 2B are in rolling contact with each other. Further, when viewed from the chain width direction W, the movement trajectory of the contact portion T with respect to the first pin 3 forms an involute curve as a predetermined curve having a predetermined starting portion J (starting point).

According to the present embodiment, it is possible to further increase the number of first pins 3 to be bitten by each pulley at a shorter connection pitch between the first pins 3. Thereby, the load per 1st pin 3 can be reduced, the collision force with each pulley can be reduced, and noise can be reduced more.
In the present embodiment, the first pin 3A may be further provided, and the first pin 3 and the first pin 3A may be randomly arranged in the chain traveling direction X.

  While several embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, in each of the embodiment shown in FIGS. 1 to 7 and the embodiment shown in FIG. 8, the first pins 3 and 3 </ b> A are loosely fitted in the corresponding rear through holes 10 of the links 2. Also good. The second pin 4 may be loosely fitted in the corresponding front through hole 9 of each link 2.

Further, the second pin 4 may be engaged with the pulleys 60 and 70. Further, the shape of the rear portion 19 of the second pin 4 paired with the shape of the front portions 25 and 25A of the first pins 3 and 3A may be exchanged to make the second pin 4 a predetermined power transmission member. .
Furthermore, in the embodiment shown in FIG. 9, the first pin 3 may be loosely fitted in the rear through hole 10B of each link 2B.

  In each of the above embodiments, a first pin having a curved surface portion made of an involute curved surface and a first pin having a curved surface portion made of a curved surface other than the involute curved surface may be used in combination. Furthermore, the 1st pin in which the extension part is not provided may be included. Further, three or more types of first pins having different trajectories of rolling and sliding contact of the contact portion may be included.

Further, a member having a power transmission part similar to the end surface of the first pin is disposed in the vicinity of each of the pair of end parts in the longitudinal direction of the first pin, and the first pin and the power transmission surface are provided. A power transmission block including a member may be provided and used as a power transmission member.
Moreover, you may mutually replace the arrangement | positioning of the front through-hole of a link, and a rear through-hole. Furthermore, you may provide a communicating groove (slit) in the pillar part between the front through-hole of a link, and a rear through-hole. In this case, the elastic deformation amount (flexibility) of the link can be increased, and the stress generated in the link can be further reduced.

  Further, the present invention is not limited to a mode in which the groove widths of both the drive pulley 60 and the driven pulley 70 are changed, and may be a mode in which only one of the groove widths is changed and the other is a fixed width that does not change. good. Furthermore, although the aspect in which the groove width continuously changes (steplessly) has been described above, the groove width may be changed stepwise or may be applied to other power transmission devices such as a fixed type (stepless). .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view schematically showing a main configuration of a chain type continuously variable transmission as a power transmission device including a power transmission chain according to an embodiment of the present invention. FIG. 2 is a partially enlarged cross-sectional view of the drive pulley (driven pulley and chain) of FIG. 1. It is typical sectional drawing of a continuously variable transmission, (A) has shown the state by which the effective radius of the drive pulley was made into the minimum while the effective radius of the driven pulley was made into the maximum, (B) is a drive pulley. The effective radius of the driven pulley is maximized and the effective radius of the driven pulley is minimized. It is sectional drawing of the principal part of a chain. It is sectional drawing which follows the II-II line | wire of FIG. 4, and has shown the linear area | region of the chain. It is a side view of the bending area | region of a chain. It is an expanded sectional view of the important section of the 1st pin. It is a partial cross section figure of the principal part of another embodiment of this invention. It is a partial cross section figure of the principal part of another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Chain (power transmission chain), 3, 3A ... 1st pin (connection member, predetermined power transmission member), 12, 12A ... Front part (opposing part), 25, 25A ... Curved surface part, 26 ... Extension Part, J, JA ... start part (start point), T, TA ... contact part (contact point), V1 ... reverse direction

Claims (4)

In a power transmission chain comprising a plurality of links and a plurality of connecting members that connect these links so as to be bendable,
Each coupling member includes a predetermined power transmission member that rolls and slides in contact with a pair member that is either a link or a member that is interposed between the link and a bend between the links.
The movement trajectory of the contact point seen from the chain width direction of the predetermined power transmission member and the pair member with the bending between the links forms a predetermined curve having a predetermined starting point,
The facing portion of the predetermined power transmission member with respect to the pair member extends in a direction opposite to the curved surface portion from the curved surface portion for achieving the predetermined curve as the movement locus of the contact point. Including
Facing portion of the predetermined power transmission member in the linear region of the power transmission chain, Ri Citea into contact with even number members at the origin and the extending portion of the curved surface portion,
The facing portion of the pair member with respect to the predetermined power transmission member is a flat surface,
The extending portion of the power transmission member is a flat surface,
Power transmission chain substantially the entire extension of the above-mentioned power transmission member is characterized that you have contacted the facing portion and the surface of the kinematic pair members in the chain linear region. In Claim 1 , each of the plurality of links includes first and second through holes arranged in the chain traveling direction,
The predetermined power transmission member includes a power transmission member that is fitted into the first through hole so as to be relatively movable, and a power transmission member that is fitted into the second through hole while being restricted in relative movement. A characteristic power transmission chain. 3. The power transmission chain according to claim 1, wherein the predetermined power transmission member includes a plurality of types of power transmission members having different moving loci of rolling and sliding contact with the even-numbered member. First and second pulleys having opposing pair of conical sheave surfaces, respectively, wound around between these pulleys, according to claim 1, wherein transmitting power in contact with the sheave surfaces A power transmission device comprising: a power transmission chain.

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