JP2008267579A - 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 reducing noises by reducing the pitch length in a pseudo manner. <P>SOLUTION: A protrusion 26 in contact with the sheave surface of the pulley is provided on the outermost 10 link out of links 10 and 11 disposed along the width of the chain. Since the protrusion 26 is in contact with the sheave surface of the pulley, the original pitch length P is equal to the sum of P1 and P2 (P = P1 + P2, P1 ≈ P/2, P2 ≈ P/2) in a pseudo manner. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  As a continuously variable transmission for an automobile, as shown in FIG. 9, 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 that connect the links arranged in a row so as to be bendable in the length direction, and are fixed to the front insertion portion of one link and movable to the rear insertion portion of another link The first pin that is fitted and the second pin that is movably fitted to the front insertion portion of one link and fixed to the rear insertion portion of the other link are relatively rolled and moved in contact with each other. Those that can be bent in the length direction have been proposed.
JP 2005-233275 A

  In the above-described conventional power transmission chain, the distance between the adjacent rolling contact surfaces (= pitch length) is ensured to be a predetermined value (for example, 6 mm) or more in consideration of the durability of the pins and links. Yes. The pitch length can be rephrased as an interval between pins contacting the pulley, and the sound of the pin colliding with the pulley is generated at an interval corresponding to the pitch length. In order to reduce noise, it is preferable that the interval (pitch length) between the sounds of the pins colliding with the pulley is as small as possible. However, when the pitch length is reduced, there is a concern that the durability may be lowered.

  An object of the present invention is to provide a power transmission chain and a power transmission device that reduce noise by artificially reducing the pitch length.

  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 that are connected to each other so as to be able to bend in the length direction, and the first pin and the second pin are in rolling contact with each other, whereby the links are bent in the length direction. In a power transmission chain in which at least one end face of at least one of the first pin and the second pin is in contact with the sheave surface of the pulley and power is transmitted by frictional force, A convex portion that contacts the sheave surface of the pulley is formed on the outermost side.

  A convex part may be provided in all the outermost links, and may be provided only in one part. The convex portion is for artificially setting the pitch length to a small pitch, and is formed so as to be substantially flush with the end surface of the pin that contacts the sheave surface of the pulley so as to contact the sheave surface of the pulley. . This is advantageous for noise reduction, and if the pitch length is reduced, the durability may be reduced. However, the outermost link in the chain width direction has a convexity that contacts the sheave surface of the pulley. By adopting the configuration in which the portion is formed, the collision sound of the pin in the pulley, which has conventionally been generated every one pitch length, is generated in a pseudo-pitch, and the fluctuation of the sound pressure level is suppressed, which is annoying. Sound reduction is achieved.

  The link has a front column part on the front side of the front insertion part, a rear column part on the rear side of the rear insertion part, and an intermediate column part between the front insertion part and the rear insertion part, and a convex part. Is formed when the link is press-molded. The convex portion is preferably provided in the intermediate column portion, but is not limited thereto, and may be provided in the front column portion and the rear column portion in addition to the intermediate column portion. Alternatively, it may be provided only at the rear column. When the convex portion is provided in the intermediate column portion, it may be provided over the entire length of the link in the chain radial direction, and is provided only between the front insertion portion and the rear insertion portion (at a height substantially equal to the height of the pin). May be. Further, since the intermediate column portion has little contribution to the strength of the link, the convex portion may be formed by cutting up the half portion on the outer side in the chain radial direction.

  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 the rear insertion portion of another link. In this case, the fixing (press-fitting) is performed at the edges (upper and lower portions) of the portion orthogonal to the length direction of the insertion portion. Edge).

  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, the pin is referred to as “first pin” or “pin”, and the other is referred to as the pin that does not contact the pulley (interpiece or strip). "Peace").

  The link is made of, for example, 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. 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 in a required curved surface so that one of the rolling contact surfaces is a flat surface and the other rolling contact surface is relatively rolling and movable. Moreover, you may make it a rolling contact surface form a required curved surface for the 1st pin and the 2nd pin. In any case, two types of rolling contact surface shapes of each pin (for example, those having a relatively large curvature and those having a relatively small curvature) are formed, so that the locus of the rolling contact movement is different. There may be two types of pin pairs. The locus of the contact position between the first pin and the second pin is, for example, an involute curve. The first pin and the second pin may have different cross-sectional shapes or the same shape.

  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 above power transmission chain, one of the pins (interpiece) is shorter than the other pin (pin), the end surface of the longer pin contacts the conical sheave surface of the pulley of the continuously variable transmission, It is preferable that power is transmitted by the frictional force due to this contact. Each pulley is composed of 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. Is moved by the hydraulic actuator, the distance between the sheave surfaces of the continuously variable transmission, that is, the wrapping radius of the chain is changed, and the continuously variable transmission can be performed with smooth movement.

  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 in any of the above.

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

  According to the power transmission chain and the power transmission device of the present invention, the outermost link arranged in the chain width direction is formed with the convex portion that contacts the sheave surface of the pulley. The pin collision noise in the pulley that has been generated is generated in a pseudo-pitch and noise can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the top and bottom refer to the top and bottom of FIG.

  FIG. 1 shows a part of a power transmission chain according to the present invention. The power transmission chain (1) has front and rear insertion portions (12) and (13) provided at predetermined intervals in the chain length direction. A plurality of links (10) (11) and a plurality of pins (first pins) (14) and interpieces (first ones) linking the links (10) (11) arranged in the chain width direction so as to be bendable in the length direction 2 pins) (15). The interpiece (15) is made shorter than the pin (14), and both are opposed to each other with the interpiece (15) disposed on the front side and the pin (14) disposed on the rear side.

  In FIG. 1, the outermost link (10) of the links (10) and (11) arranged in the chain width direction is formed with a convex portion (26) substantially flush with the end face of the pin (14).

  In the chain (1), three link rows composed of a plurality of links having the same phase in the chain traveling direction are arranged in the traveling direction (front-rear direction) to form one link unit, and the link unit comprising the three rows of link rows travels. A plurality are connected in the direction. In this embodiment, one link unit includes a link row having nine links and two link rows having eight links.

  3 and 4 show the outermost link (10) among the links (10) and (11) arranged in the chain width direction, and FIG. 2 shows another standard link (11).

  As shown in FIGS. 2 and 3, the pin (14) is wider in the front-rear direction than the interpiece (15), and the pin (14) is provided at the upper and lower edges of the interpiece (15). Protruding edges (15a) and (15b) extending to the side are provided.

  Each link (10) (11) has a front column portion (20) for forming the front shape of the front insertion portion (12) and a rear column portion for forming the rear shape of the rear insertion portion (13). (22) and an intermediate column portion (21) between the front insertion portion (12) and the rear insertion portion (13). The front insertion part (12) of the links (10) and (11) includes a pin movable part (16) to which the pin (14) is movably fitted and an interpiece fixing part (17) to which the interpiece (15) is fixed. The rear insertion portion (13) includes a pin fixing portion (18) to which the pin (14) is fixed and an interpiece movable portion (19) to which the interpiece (15) is movably fitted.

  As shown in FIGS. 3 and 4, the outermost link (10) of the links (10) and (11) arranged in the chain width direction is an intermediate column as compared to the standard link (11) shown in FIG. The only difference is that the convex portion (26) is formed on the portion (21). The convex portion (26) is provided over the entire length of the link (10) in the chain radial direction (up and down in the figure), and the inclination angle of the conical sheave surfaces (2c) and (2d) of the pulley (2) is 11 °. Considering this, as shown in FIG. 4, it has a tip surface (26a) having the same inclination angle.

  When connecting the links (10) (11) arranged in the chain width direction, the front insertion part (12) of one link (10) (11) and the rear insertion part (13) of the other links (10) (11) ) And the links (10) and (11) are overlapped so that the pin (14) is fixed to the rear insertion portion (13) of one link (10) (11) and the other link (10) (11) is movably fitted to the front insertion part (12), and the interpiece (15) is movably fitted to the rear insertion part (13) of one link (10) (11) and the other It is fixed to the front insertion part (12) of the links (10) (11). Then, the pin (14) and the interpiece (15) are relatively rolled and brought into contact with each other, whereby the links (10) and (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.In this embodiment, the contact surface of the pin (14) It has an involute shape having a base circle of radius Rb and center M, and the contact surface of the interpiece (15) is a flat surface (the cross-sectional shape is a straight line). As a result, when each link (10) (11) moves from the straight part of the chain (1) to the curved part or from the curved part to the straight part, the pin (14) is fixed at the front insertion part (12). The contact surface of the interpiece (15) in the state moves in the pin movable part (16) while rolling (including some sliding contact) to the contact surface of the interpiece (15), and the rear insertion part ( In 13), the contact surface of the interpiece (15) rolls into contact with the contact surface of the pin (14) with respect to the pin (14) fixed in the interpiece movable part (19). Move). 2 and 3, the portions indicated by reference signs A and B are lines (points in the cross section) where the pin (14) and the interpiece (15) are in contact with each other in the straight portion of the chain (1). , AB is the pitch.

  The power transmission chain described above is used in the CVT shown in FIG. 9. At this time, as shown in FIG. 5, 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.

  The interval at which the pin (14) collides with the sheave surface (2c) (2d) of the pulley (2) is 1 pitch length. To make the sound generated at this time unharmed, the pitch length should be as small as possible. Is preferred. However, the pitch length needs to be a certain size or more in consideration of durability, and cannot be reduced only for noise reduction. Therefore, in the power transmission chain (1) according to the present invention, the convex portion (26) formed on the outermost link (10) among the links (10) and (11) arranged in the chain width direction is shown in FIG. As described above, the pitch length is made to be a pseudo small pitch by contacting the sheave surfaces (2c) and (2d) of the pulley (2). That is, in FIG. 1, the convex portion (26) contacts the sheave surface (2c) (2d) of the pulley (2) with respect to the original pitch length P, so that P1 and P2 (P = P1 + P2) are simulated. , P1≈P / 2, P2≈P / 2) is the pitch length.

  In this power transmission chain (1), the necessary number of pins (14) and interpieces (15) are held vertically on a table, and then one or several links (10) and (11) are collected. Manufactured by press-fitting. This press-fitting is performed between the upper and lower edges of the pin (14) and the interpiece (15) and the upper and lower edges of the pin fixing part (18) and the interpiece fixing part (17). It is set to 0.005 mm to 0.1 mm. In this way, tension is applied (pre-tensioned) to the assembled chain (1).

  In the above power transmission chain (1), polygonal vibration is caused by repeated vertical movement of the pin, which causes noise, but the pin (14) and the interpiece (15) are relatively rolled and moved in contact. In addition, since 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, both the contact surfaces of the pin and the interpiece are arcuate surfaces. Compared to the case, vibration can be reduced and noise can be reduced. Further, the noise is reduced even when the pitch (26) comes into contact with the sheave surfaces (2c) (2d) of the pulley (2) so that the pitch length becomes a pseudo small pitch.

  In addition, since the convex part (26) formed in the link (10) in order to make the pitch length a pseudo small pitch does not bear a load, it is limited to those shown in FIG. 3 and FIG. However, various modifications are possible as long as the shape contacts the sheave surfaces (2c) and (2d) of the pulley (2).

  For example, the protrusion (27) formed on the outermost link (10) may have a tip surface (27a) parallel to the main body portion of the link (10), as shown in FIG. In this case, only a part of the tip surface (27a) comes into contact with the sheave surfaces (2c) and (2d) of the pulley (2).

  Further, as shown in FIG. 7, the convex portion (28) formed on the outermost link (10) may be formed by raising a half portion on the outer side in the chain radial direction. The intermediate column (21) contributes little to the strength of the link (10), and this outermost link (10) only adds a cutting and raising process to the process of obtaining the standard link (11). Since it can be obtained, it is possible to reduce the trouble of manufacturing the two types of links (10) and (11).

  Further, as another example in which the convex portion (29) is not provided over the entire length of the link (10) in the chain radial direction (up and down in the drawing), the convex portion (29) formed on the outermost link (10) is shown in FIG. As shown in Fig. 2, the intermediate column part (21) is formed only in the middle part in the vertical direction (between the front insertion part (12) and the rear insertion part (13)), and its end face (29a) is a convex curved surface. You may make it become.

FIG. 1 is a plan view showing a part of one embodiment of a power transmission chain according to the present invention. FIG. 2 is an enlarged side view of a standard link and pin. FIG. 3 is an enlarged side view of the outermost link and pin. FIG. 4 is an enlarged perspective view of the outermost link. FIG. 5 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 6 is an enlarged perspective view showing another example of the outermost link. FIG. 7 is an enlarged perspective view showing still another example of the outermost link. FIG. 8 is an enlarged perspective view showing still another example of the outermost link. FIG. 9 is a perspective view showing an example of a continuously variable transmission in which the power transmission chain according to the present invention is used.

Explanation of symbols

(1) Power transmission chain
(2) (3) Pulley
(2a) (3b) Fixed sheave
(2b) (3a) Movable sheave
(2c) (2d) Conical sheave surface
(10) Outermost link
(11) Standard link
(12) Front insertion part
(13) Rear insertion part
(14) Pin (1st pin)
(15) Interpiece (2nd pin)
(26) (27) (28) (29) Convex

Claims (2)

Links in the chain width direction can be bent in the length direction so that multiple links with front and rear insertion parts through which pins are inserted, and the front insertion part of one link and the rear insertion part of another link correspond to each other A plurality of first pins and a plurality of second pins connected to each other, 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 longitudinal direction. In the power transmission chain in which at least one end face of each of the first pin and the second pin is in contact with the sheave surface of the pulley and power is transmitted by frictional force,
A power transmission chain, wherein a convex portion that contacts a sheave surface of a pulley is formed on an outermost link arranged in a chain width direction.   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. A power transmission device according to claim 1.

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