JP2008208980A - Power transmission chain and power transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission chain and a power transmission system which prevents a pin from coming out of a part to which a link is fixed. <P>SOLUTION: The power transmission chain 1 is provided with a plurality of links 11, a plurality of pins 14, and a plurality of inter pieces 15, and the plurality of links 11 have the front and rear insertion parts 12, 13. A recess 20 shaped like a bow in cross section is extended and formed in the longitudinal direction of the pin 14 on at least the surface 14b opposite to the surface 14a brought into rolling contact with the pin 14 among the pin 14 and the inter piece 15. The protrusion 21 corresponding to the recess 20 is formed in the rear insertion part 13. <P>COPYRIGHT: (C)2008,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. 6, the automatic transmission for an automobile has a fixed sheave (2a) having a conical sheave surface and a movable sheave (2b) having a conical sheave surface, and is provided on the engine side. Drive pulley (2), driven sheave (3) provided on the drive wheel side with fixed sheave (3b) and movable sheave (3a), and endless power transmission chain (1) spanned between them The movable sheave (2b) (3a) is moved toward and away from the fixed sheave (2a) (3b) by a hydraulic actuator, and the chain (1) is clamped and brought into contact with the hydraulic sheave. A device that transmits torque by the frictional force is known.

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 a row, and the first pin and the second pin are relatively in rolling contact and moved, so that the links can be bent in the longitudinal direction. It has been proposed to be used between a first pulley having a conical sheave surface and a second pulley having a conical sheave surface.
JP 2005-233275 A

  In the power transmission chain of Patent Document 1, the pin and the interpiece are brought into rolling contact when the chain is rotated, and the load point applied to the rolling contact surface (the surface that contacts the other pin) is moved, whereby the link is fixed to the pin. The moment force in the direction of exiting from the part (clockwise or counterclockwise) works.

  An object of the present invention is to provide a power transmission chain and a power transmission device that can prevent a pin from coming out of a fixed portion of a link.

  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. One of the first pin and the second pin is fixed to the front insertion portion of one link and movably fitted to the rear insertion portion of the other link, and the other is connected to the front insertion portion of the one link. In the power transmission chain that is movably fitted in the insertion portion and fixed to the rear insertion portion of another link, the fixing is fixed to the concave arc-shaped portion of the insertion portion corresponding to the convex arc-shaped upper and lower edges of each pin. Line by being press-fitted A concave portion having an arcuate cross-sectional shape is formed on the surface opposite to the rolling contact surface of at least one of the first pin and the second pin, and extends in the length direction of the pin. The convex part corresponding to is formed in each insertion part, It is characterized by the above-mentioned.

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

  Each pin of the first pin and the second pin has a surface that contacts the other pin (hereinafter referred to as a “rolling contact surface”) and a surface that contacts the inner edge of the front and rear insertion portion of the link opposite to the surface (hereinafter referred to as “rolling contact surface”). (Referred to as “rear surface”).

  The cross-sectional shape of the concave portion and the convex portion is, for example, an arc shape, and preferably includes an upper and lower arc portion and a linear portion interposed therebetween. The straight line portion can be used as a reference plane that determines a predetermined angle (attack angle) of the pin with respect to a plane orthogonal to the chain traveling direction.

  The arcuate recess may be provided in both the first pin and the second pin, or may be provided in either one of them. Preferably, one of the first pin and the second pin is wider than the other pin and is in contact with the pulley to transmit power by frictional force, and the rolling contact surface of the pin not in contact with the pulley is The rolling contact surface of the pin that contacts the flat surface and the pulley is formed in an involute curved surface, and the concave portion is provided only on the pin that contacts the pulley. The pin with the involute curve will receive a relatively large rotational moment, and by finding a recess only in the pin that is wider and susceptible to the rotational moment, without affecting the durability, etc. The problem that the pin is easy to rotate can be solved.

  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. In the link, the front and rear insertion portions may be independent through holes (links with columns), or 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.

  When the chain rotates, as the pin and the interpiece are brought into rolling contact, the load point moves up and down on the rolling contact surface of the pin, and a clockwise or counterclockwise moment force is applied to the pin. Then, the pin may rotate and the pin may come out from the part fixing the pin of the link, but when the concave part of the pin shape of the pin and the convex part of the insertion part corresponding to this are formed, The upper and lower circular arc portions of the concave portion of the pin hit the convex portion of the insertion portion, and the rotation of the pin is prevented.

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. The chain is sandwiched between the sheave surfaces of both sheaves. By moving the shaft with a hydraulic actuator, the wrapping radius of the chain changes according to the distance between sheave surfaces of the continuously variable transmission, and a 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 above.

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

  According to the power transmission chain and the power transmission device of the present invention, the concave portion having an arcuate cross section is formed extending in the length direction of the pin, and the convex portion corresponding to the concave portion is formed in each insertion portion. Therefore, even when the pin is about to rotate, the upper and lower circular arc portions of the concave portion of the pin hit the convex portion of the insertion portion to prevent the pin from rotating, and the pin can be prevented from coming off from the portion where the pin of the link is fixed. . Moreover, since rotation of the pin is prevented, fretting between the link and the pin can be prevented, and the life of the pin can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the right in FIG. 2 is the front and the left is the rear.

  1 and 2 show a part of the power transmission chain of the present invention. The power transmission chain (1) has front and rear insertion portions (12) and (13) through which pins (14) and (15) are inserted. A plurality of links (11), a link (11) arranged in the chain width direction so that a front insertion portion (12) of one link (11) and a rear insertion portion (13) of another link (11) correspond to each other. ) Comprising a plurality of first pins (pins) (14) and a plurality of second pins (interpieces) (15) arranged before and after connecting the first pin (14) and the second pin (15); By relatively rolling and moving in contact with each other, the links (11) can be bent in the length direction. The interpiece (15) is made shorter than the pin (14), and both (14) and (15) are opposed to each other with the interpiece (15) disposed on the front side and the pin (14) disposed on the rear side. ing.

  The chain (1) is a link unit consisting of a plurality of link rows composed of a plurality of links (11) having the same phase in the width direction as a link unit by arranging three link rows in the traveling direction (front-rear direction). Are connected in the traveling direction. In this embodiment, a link row having nine links (11) and two link rows having eight links (11) are used as one link unit.

  As shown in FIG. 3, the front insertion part (12) of the link (11) has a pin movable part (16) to which the pin (14) is movably fitted and an interpiece fixing to which the interpiece (15) is fixed. The rear insertion part (13) consists of a pin fixing part (18) to which the pin (14) is fixed and an interpiece movable part (19) to which the interpiece (15) is movably fitted. Become.

  At the boundary between the pin fixing part (18) of the link (11) and the interpiece movable part (19), the upper and lower concave arcuate guide parts (19a) (19b) of the interpiece movable part (19) are connected. Upper and lower convex arc-shaped holding portions (18a) and (18b) for holding the pin (14) fixed to the pin fixing portion (18) are provided. Similarly, at the boundary between the interpiece fixing part (17) and the pin movable part (16), the upper and lower concave arcuate guide parts (16a) and (16b) of the pin movable part (16) are connected to the interpiece fixed part. Upper and lower convex arc-shaped holding portions (17a) and (17b) for holding the interpiece (15) fixed to the portion (17) are provided.

  The pin (14) has a wider width in the front-rear direction than the interpiece (15), and the upper and lower protruding edges (15a) extending toward the pin (14) are provided on the upper and lower edges of the interpiece (15). (15b) is provided, and the contact surface (rolling contact surface) (15c) and the opposite surface (back surface) (15d) of the interpiece (15) are flat surfaces (the cross-sectional shape is a straight line).

  The locus of the contact position between the pin (14) and the interpiece (15) with respect to the pin (14) is an involute of a circle. In this embodiment, the contact surface (rolling contact surface) of the pin (14) ) (14a) has an involute shape with a base circle of radius Rb and center M in cross section.

  As shown in FIG. 3 and FIG. 4, a concave portion (20) having an arcuate cross section is formed on the surface (back surface) (14b) of the pin (14) that contacts the link (11). A convex portion (21) corresponding to the concave portion (20) is formed in the rear insertion portion (13) of the link (11). The concave portion (20) and the convex portion (21) are formed by upper and lower circular arc portions (22) and (23) and a linear portion (24) interposed therebetween. The straight portion (24) is used as a reference surface for determining a predetermined angle of attack of the pin (14) with respect to a plane perpendicular to the traveling direction of the chain (1).

  This power transmission chain (1) holds the required number of pins (14) and interpieces (15) vertically on the table, and then press-fits one or several links (11) one by one. It is manufactured by going. 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. As described above, the pin (14) and the interpiece (15) are fixed by, for example, mechanical press-fitting, but may be shrink-fitted or cold-fitted instead. After the fitting and fixing, the pre-tension is applied in the pre-tension applying step, so that the pin fixing portion (18) of the link (11) is evenly and appropriately given a residual compressive stress.

  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).

  When each link (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) and the interpiece (15) are in rolling contact (slightly sliding contact). Are included in the upper and lower concave arcuate guides (16a) and (16b) of the pin movable part (16) and the upper and lower concave arcuate guides (19a and 19b) of the interpiece movable part (19). Move. As a result, the load point moves from the position indicated by A and B to the upper side (the outer diameter side of the chain) A ′ and B ′, and the pin (14) and the interpiece (15) are indicated by a two-dot chain line. The relative position is changed so that those upper edge portions (chain outer diameter side edge portions) approach each other. Along with this change, moment force F is applied to the pin (14), and the pin (14) tries to rotate counterclockwise, but the upper arc portion (22) of the recess (20) of the pin (14) is inserted backward. The pin (14) is prevented from rotating by hitting the convex part (21) of the part (13). Further, the load point of the pin (14) moves from the position indicated by A 'and B' to the position of A and B, and the pin (14) and the interpiece (15) are moved to the position indicated by the solid line. When the relative position is changed so that the parts (chain inner diameter side edges) approach each other, the moment force F 'is applied to the pin (14) with this change, and the pin (14) tries to rotate clockwise. However, similarly to the above, the lower arc part (23) of the concave part (20) of the pin (14) hits the convex part (21) of the rear insertion part (13), and the rotation of the pin (14) is prevented. Thus, by preventing the rotation of the pin (14), it is possible to prevent the pin from coming out of the portion where the pin of the link is fixed. Furthermore, since rotation of the pin is prevented, fretting between the pin (14) and the link (11) is prevented, and the life of the pin (14) can be improved.

  In FIG. 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). Is the pitch.

  In the above power transmission chain (1), polygonal vibration is generated by repeated vertical movement of the pin (14), which causes noise, but the pin (14) and the interpiece (15) are relatively The pin (14) and the interpiece (15) are moved by rolling contact and the locus of the contact position between the pin (14) and the interpiece (15) with respect to the pin (14) is an involute of a circle. Compared with the case where both of the contact surfaces (14a) and (15c) are arcuate surfaces, vibration can be reduced and noise can be reduced.

  The power transmission chain (1) is used in the CVT shown in FIG. 6. At this time, as shown in FIG. 5, the end face of the interpiece (15) is fixed sheave (2a) of the pulley (2). And the end surface of the pin (14) is in contact with the conical sheave surface (2c) (2d) of the pulley (2) without being in contact with each conical sheave surface (2c) (2d) of the movable sheave (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.

  In the chain type power transmission chain (1), polygonal vibration is generated by repeated vertical movement of the pin (14), which causes noise, but the pin (14) and the interpiece (15) are relatively The pin (14) and the interpiece (15) are moved in a rolling manner and the locus of the contact position between the pin (14) and the interpiece (15) with reference to the pin (14) is involute. Compared with the case where both of the contact surfaces are arc surfaces, vibration can be reduced and noise can be reduced.

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 perspective view of the same. FIG. 3 is an enlarged side view of the link and the pin. FIG. 4 is an enlarged schematic view for explaining the characteristic portion of the pin according to the present invention. FIG. 5 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 6 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)
(14a) Rolling contact surface
(14b) Rear side
(15) Interpiece (2nd pin)
(16) Pin movable part
(17) Interpiece fixing part (pin fixing part)
(18) Pin fixing part
(19) Interpiece movable part (Pin movable part)
(20) Concave
(21) Convex
(22) Upper arc
(23) Lower arc
(24) Straight section

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 aligned 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. The first pin and the plurality of second pins are provided, and the first pin and the second pin are relatively in rolling contact with each other, whereby the links can be bent in the longitudinal direction. One of the two pins is fixed to the front insertion part of one link and is movably fitted to the rear insertion part of the other link, and the other is movably fitted to the front insertion part of one link. In the power transmission chain that is fixed to the rear insertion portion of the other link, the fixing is performed by pressing the convex arc-shaped upper and lower edge portions of each pin into the concave arc-shaped portion of the corresponding insertion portion. 1st pin and 2nd pin A concave portion having an arcuate cross section extends in the length direction of the pin on the surface opposite to the rolling contact surface of at least one pin, and a convex portion corresponding to this concave portion is formed in each insertion portion. A power transmission chain characterized by   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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