JP2009103155A - Power transmission chain and power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission chain and a power transmission device capable of continuously and stably retaining string vibration suppression effect of the chain. <P>SOLUTION: An annular body 21 with a large diameter contacted with the chain 1 from an outer side in a radial direction is provided on an outer side in a chain radial direction, and an annular body 22 with a small diameter contacted with the chain 1 from an inner side in a radial direction is provided on an inner side in a chain radial direction. Relative to bending of the mutual adjacent links 11, the annular bodies 21, 22 are elastically deformed and the link 11 is returned in the original state by the elastic force. Thereby, string vibration of the chain is quickly attenuated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power transmission chain, and more particularly to a power transmission chain and a power transmission device suitable for a continuously variable transmission (CVT) of a vehicle such as an automobile.

  As shown in FIG. 4, as a continuously variable transmission for an automobile, a drive pulley (2) provided on the engine side having a fixed sheave (2a) and a movable sheave (2b), a fixed sheave (3b) and a movable sheave (3a) and a driven pulley (3) provided on the drive wheel side and an endless power transmission chain (1) spanned between them, and a movable sheave (2b) (3a) by a hydraulic actuator The chain (1) is clamped with hydraulic pressure by moving it toward and away from the fixed sheave (2a) (3b), and this clamping force makes contact between the pulley (2) (3) and the chain (1). It is known that a load is generated and torque is transmitted by the frictional force of the contact portion.

As a power transmission chain, in Patent Document 1, a plurality of links having front and rear insertion portions through which pins are inserted, a front insertion portion of one link, and a rear insertion portion of another link correspond to the chain width direction. A plurality of first pins and a plurality of second pins arranged before and after connecting the links arranged in parallel, and the first pin and the second pin are relatively in rolling contact and moved, whereby the links are bent in the length direction. What is possible has been proposed.
JP 2005-233275 A

  In the power transmission chain of Patent Document 1, a gap is provided between adjacent links arranged in the width direction of the chain. If this gap is large, it becomes a deterrent when a string vibration of the chain occurs. Since the frictional force is lost, the problem of increased vibration and noise tends to occur. By substantially eliminating the gap, this problem can be solved, but when used for a long period of time, the effect of suppressing string vibration may be reduced by changing the gap due to wear caused by contact between the links. is there.

  An object of the present invention is to provide a power transmission chain and a power transmission device that can continuously and stably hold the string vibration suppression effect of the chain.

  The power transmission chain according to the present invention includes a plurality of links having front and rear insertion portions through which pins are inserted, and links arranged in the chain width direction so that a front insertion portion of one link and a rear insertion portion of another link correspond to each other. A plurality of first pins and a plurality of second pins arranged before and after connecting each other are provided, and the first pin and the second pin are relatively rolled and brought into contact with each other, whereby the links can be bent in the length direction. In the power transmission chain, a large-diameter annular body that comes into contact with the link from the outside in the radial direction is provided outside the chain in the radial direction, and a small-diameter annular body that comes into contact with the link from the inside in the radial direction It is characterized by being.

  Each annular body is formed of a metal belt-like thin plate so as to have elasticity to keep the chain in an annular shape when the chain is not wound around the pulley. The diameter of the large-diameter annular body when the chain is not wound around the pulley is almost equal to the outer diameter of the chain (may be slightly larger), and the small diameter when the chain is not wrapped around the pulley The diameter of the annular body is substantially equal to the inner diameter of the chain (may be slightly smaller). The large-diameter annular body preferably has higher rigidity than the small-diameter annular body, and is preferably thicker than the small-diameter annular body.

  The power transmission chain is, for example, a link row (reference link row) including links on the outermost side in the chain width direction, a front link row arranged on the front side of the reference link row, and a rear side of the reference link row. The first half of the link of the reference link row (front insertion portion) and the second half of the link of the front link row (rear insertion portion) are connected via a pin, and the link of the reference link row The latter half part (rear insertion part) and the first half part (front insertion part) of the links in the rear link row are connected via pins.

  Each annular body is preferably fixed to a link whose both edges are on the outermost side in the chain width direction. In order to facilitate this fixing, it is preferable that the outermost link in the chain width direction is provided with protrusions for supporting the annular body, and both edges of the annular body are welded to the protrusions. It is fixed by appropriate means.

  In the power transmission chain according to the present invention, at least one of the first pin and the second pin comes into contact with the pulley to transmit power by frictional force. In a chain in which one of the pins contacts the pulley, one of the first pin and the second pin is a pin that contacts the pulley when the chain is used in a continuously variable transmission ( In the following, it is referred to as “first pin” or “drive pin”, and the other is referred to as the pin that does not contact the pulley (interpiece or strip). It is called “interpiece”.

  One of the first pin and the second pin is fixed to the front insertion portion of one link and is movably fitted to the rear insertion portion of the other link, and the other is the front insertion portion of the one link. It is preferable that it is movably fitted in and fixed to a rear insertion portion of another link.

  The pin is fixed to the pin fixing portion by, for example, fitting and fixing the inner edge of the pin fixing portion and the outer peripheral surface of the pin by mechanical press-fitting. Alternatively, shrink fitting or cold fitting may be used. The fitting and fixing is preferably performed at the edges (upper and lower edges) of the portion orthogonal to the length direction of the pin fixing portion. After the fitting and fixing, a pre-tension is applied in the pre-tension applying step, so that an appropriate and residual compressive stress is equally applied to the pin fixing portion (pin press-fitting portion) of the link.

  For example, the link is made of spring steel or carbon tool steel. The material of the link is not limited to spring steel or carbon tool steel, and may of course be other steel such as bearing steel. In the link, the front and rear insertion portions may be independent through holes (links with columns), and the front and rear insertion portions may be one through holes (links without columns). Appropriate steel such as bearing steel is used as the material of the pin.

  For example, the first pin and the second pin are formed as involute curved surfaces in which either one of the contact surfaces is a flat surface and the other contact surface is relatively rollable and movable. Moreover, you may make it each contact surface form a required curved surface for the 1st pin and the 2nd pin.

  In this specification, one end side in the length direction of the link is front and the other end side is rear, but this front and rear are for convenience, and the length direction of the link always coincides with the front and rear direction. It doesn't mean that.

  In the continuously variable transmission using the power transmission chain described above, each pulley includes a fixed sheave having a conical sheave surface and a movable sheave having a conical sheave surface facing the sheave surface of the fixed sheave. The chain is sandwiched between the sheave surfaces of both sheaves, and the movable sheave is moved by a hydraulic actuator, whereby the distance between sheave surfaces of the continuously variable transmission, and hence the winding radius of the chain, is changed.

  The power transmission device according to the present invention includes a first pulley having a conical sheave surface, a second pulley having a conical sheave surface, and power transmission spanned between the first and second pulleys. And a power transmission chain as described above.

  This power transmission device is suitable for use as a continuously variable transmission for a vehicle such as an automobile.

  According to the power transmission chain of the present invention, the string vibration of the chain is suppressed by the annular body, and this string vibration suppression effect is continuously maintained stably, so that noise and vibration are reduced. In addition, the large-diameter annular body also has a function of suppressing chain elongation, and safety when excessive tension is applied is improved.

  Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, the upper side is the outer side in the chain radial direction, the lower side is the inner side in the chain radial direction, the right side is the front side in the chain moving direction, and the left side is the rear side in the chain moving direction. A description will be given with the radially inner side as the bottom.

  FIGS. 1 and 2 show a part of a power transmission chain according to the present invention. The power transmission chain (1) has front and rear insertion parts (12) (13) provided at predetermined intervals in the chain length direction. ) And a plurality of pins (first pin) (14) and an interpiece (second pin) for connecting the links (11) arranged in the chain width direction so as to be bendable in the length direction. (15). The interpiece (15) is shorter than the pin (14), and the pin (14) is wider in the front-rear direction than the interpiece (15). The pin (14) is opposed to the front side in a state of being arranged on the rear side.

  In the chain (1), three link rows composed of a plurality of links having the same phase in the width direction are arranged in the traveling direction (front-rear direction) to form one link unit, and the link unit composed of the three rows of link rows is the traveling direction. Are connected to each other.

  As shown in FIG. 2, the front insertion part (12) of each link (11) includes a pin movable part (16) to which the pin (14) is movably fitted and an interpiece to which the interpiece (15) is fixed. The rear insertion part (13) is composed of a fixed part (17), and the inter-piece movable part (19) in which the pin fixing part (18) to which the pin (14) is fixed and the inter-piece (15) are movably fitted Consists of.

  When connecting the links (11) aligned in the chain width direction, the links (11) so that the front insertion part (12) of one link (11) and the rear insertion part (13) of the other link (11) correspond to each other ( 11) are overlapped with each other, the pin (14) is fixed to the rear insertion part (13) of one link (11) and movably fitted to the front insertion part (12) of the other link (11), The interpiece (15) is movably fitted to the rear insertion portion (13) of one link (11) and fixed to the front insertion portion (12) of the other link (11). The pins (14) and the interpiece (15) are relatively rolled and brought into contact with each other, whereby the links (11) can be bent in the length direction (front-rear direction).

  The locus of the contact position between the pin (14) and the interpiece (15) with respect to the pin (14) is an involute of the circle, and in this embodiment, the rolling contact surface (14a) of the pin (14) However, it has an involute shape having a basic circle with a radius Rb and a center M in the cross section, and the rolling contact surface (15a) of the interpiece (15) is a flat surface (the cross-sectional shape is a straight line). As a result, when each link (11) moves from the straight portion of the chain (1) to the curved portion or from the curved portion to the straight portion, the pin (14) is fixed in the front insertion portion (12). The rolling contact surface (14a) of the piece (15) moves in the pin movable part (16) while making rolling contact (including some sliding contact) with the rolling contact surface (15a) of the interpiece (15). In the rear insertion part (13), the rolling contact surface (15a) of the interpiece (15) is in contact with the pin (14) in contact with the pin (14) fixed in the interpiece movable part (19). It moves while rolling (including some sliding contact) on the surface (14a).

  In FIG. 1, a gap is provided between adjacent links (11), although not shown in the figure. This gap needs to have a certain size in order to facilitate bending of the links (11) .For this reason, when string vibration of the chain (1) occurs, this gap is caused by friction between the links (11). It is difficult to attenuate the vibration.

  Therefore, in the power transmission chain (1) according to the present invention, large and small metal annular bodies (21) and (22) for restricting the bending of the link (11) are provided on the radially outer side and the inner side of the chain. Yes. Both edges of each annular body (21) (22) are fixed to the outermost link (11) by appropriate means such as welding, and the outermost link (11) has an annular shape. In order to facilitate fixing of the bodies (21) and (22), a protruding portion (23) protruding in the radial direction of the chain with respect to the other link (11) is provided. These protrusions (23) are formed by increasing the vertical dimension (diameter dimension) of the link (11A) on the outermost side in the width direction.

  Each annular body (21) (22) is formed of a metal strip-like thin plate, so that the inner circumferential length does not substantially change, but the shape seen from the axial direction is deformed. Thus, the chain (1) has elasticity to keep the chain (1) in an annular shape in a state where the chain (1) is not wound around the pulleys (2) and (3).

  As a result, when string vibration occurs in the chain (1) and the links (11) are bent, the annular body (21) (22) is elastically deformed, and each link (11) is restored to its original state by this elastic force. The string vibration of the chain (1) is quickly damped by returning. The large-diameter annular body (21) is thicker than the small-diameter annular body (22), which has the function of suppressing the chain (1) extension in addition to the function of suppressing string vibration. ing.

  In this power transmission chain (1), the required number of drive pins (14) and interpieces (15) are held vertically on an assembly jig, and then one or several links (11) are assembled together. Manufactured by press-fitting. This press-fitting is performed between the upper and lower edges of the drive pin (14) and the interpiece (15) and the upper and lower edges of the drive pin fixing part (18) and the interpiece fixing part (17). The cost is 0.005 mm to 0.1 mm. In this way, tension is applied (pre-tensioned) to the assembled chain (1).

  The power transmission chain described above is used in the CVT shown in FIG. 4. At this time, as shown in FIG. 3, the fixed sheave (2a) and the movable sheave (2) of the pulley (2) having the pulley shaft (2e). The end surface of the pin (14) is the conical sheave surface (2c) (2d) of the pulley (2) with the end surface of the interpiece (15) not in contact with each conical sheave surface (2c) (2d) of 2b). Power is transmitted by the frictional force generated by this contact. As described above, the pin (14) and the interpiece (15) are guided by the movable parts (16) and (19) to move in rolling contact with each other, so that the sheave surfaces (2c) (2d) of the pulley (2) On the other hand, the pin (14) hardly rotates, the friction loss is reduced, and a high power transmission rate is secured. When the movable sheave (2b) of the drive pulley (2) at the position indicated by the solid line is moved closer to or away from the fixed sheave (2a), the winding diameter of the chain (1) is indicated by a chain line in the figure. As shown, it is large when approaching and small when separating. Although not shown in the drawing of the driven pulley (3), when the movable sheave moves in the opposite direction to the movable sheave (2b) of the drive pulley (2) and the winding diameter of the drive pulley (2) increases, the driven pulley (2) When the winding diameter of (3) decreases and the winding diameter of the drive pulley (2) decreases, the winding diameter of the driven pulley (3) increases. As a result, with reference to the state (initial value) where the gear ratio is 1: 1, U / D has the minimum winding diameter of the drive pulley (2) and the maximum winding diameter of the driven pulley (3). A state is obtained, and an O / D state in which the winding diameter of the drive pulley (2) is maximum and the winding diameter of the driven pulley (3) is minimum is obtained.

  In the above power transmission chain (1), polygonal vibration occurs due to repeated vertical movement of the pin, which causes noise, but the drive pin (14) and the interpiece (15) are relatively in rolling contact. Because the locus of the contact position between the drive pin (14) and the interpiece (15) with respect to the drive pin (14) is an involute of a circle, both the contact surfaces of the drive pin and the interpiece are Compared with the case of a circular arc surface, vibration can be reduced and noise can be reduced. Moreover, since the string vibration of the chain (1) is suppressed by the annular bodies (21) and (22), vibration and noise can be further reduced.

FIG. 1 is a front view showing a part of one embodiment of a power transmission chain according to the present invention. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 4 is a perspective view showing a continuously variable transmission.

Explanation of symbols

(1) Power transmission chain
(2) (3) Pulley
(2a) (3b) Fixed sheave
(2b) (3a) Movable sheave
(2c) (2d) Conical sheave surface
(11) Link
(12) Front insertion part
(13) Rear insertion part
(14) Pin (1st pin)
(15) Interpiece (2nd pin)

Claims (2)

A plurality of links having front and rear insertion portions through which pins are inserted, and a plurality of links arranged before and after connecting links arranged in the chain width direction so that a front insertion portion of one link and a rear insertion portion of another link correspond to each other. In the power transmission chain provided with the first pin and the plurality of second pins, the first pin and the second pin are in rolling contact with each other, whereby the links can be bent in the length direction.
A large-diameter annular body that comes into contact with the link from the outside in the radial direction is provided outside the chain in the radial direction, and a small-diameter annular body that comes into contact with the link from the inside in the radial direction is provided inside the chain in the radial direction. Power transmission chain.   A power transmission chain comprising: a first pulley having a conical surface sheave surface; a second pulley having a conical surface sheave surface; and a power transmission chain spanned between the first and second pulleys. The power transmission device according to claim 1.

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