JP2009222103A - Power transmission chain and power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission chain preventing the deterioration of durability caused by minute damage during machining, and to provide a power transmission device. <P>SOLUTION: A plate-like link material 10 is formed by drawing work so that its bottomed cylindrical portion 10a has a cross section shaped to be front and rear insertion portions 12, 13 (Fig.a). Then, all of the bottomed cylindrical portions 10a or part including the bottom thereof are removed. Thereby, inner peripheral faces of the front and rear insertion portions 12, 13 of each link 11 are formed as non-cut faces S. <P>COPYRIGHT: (C)2010,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 a power transmission chain for a continuously variable transmission, Patent Document 1 corresponds to 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. In this way, a plurality of first pins and a plurality of second pins arranged before and after connecting the links arranged in the chain width direction are provided. Bending in the vertical direction is possible, and 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, The other has been proposed that is movably fitted in the front insertion part of one link and fixed to the rear insertion part of another link.
JP 2005-233275 A

  In the power transmission chain of Patent Document 1, each link is formed by press forming (punching) a material. According to the punching process, the inner circumferential surface of each link insertion part of each link becomes a cut surface (fracture surface), and micro scratches such as sagging, burrs, and shearing surfaces occur on the inner circumferential surface of the link insertion part. However, there is a concern that the durability of the link may be reduced by the press-fit of the pin.

  An object of the present invention is to provide a power transmission chain and a power transmission device that prevent a decrease in durability due to minute scratches during processing.

  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, the front and rear insertion portions of each link are characterized in that their inner peripheral surfaces are non-cut surfaces.

  In the conventional link processing method (punching), the inner peripheral surface of the front / rear insertion portion of each link becomes a cut surface, whereas in the power transmission chain of the present invention, the front / rear insertion portion of each link has a peripheral portion. By being bent in a substantially right angle direction, the inner peripheral surface is formed by a link material surface which is a non-cut surface.

  That is, in the conventional one, the inner peripheral surface of the front and rear insertion portion of the link becomes a cut surface (shear surface and fracture surface) by a press die, and micro-scratches such as detachment and burrs are likely to occur at this time. When a pin is inserted into the front and rear insertion portion of the link, such a punched surface may cause a link breakage. On the other hand, in the power transmission chain of the present invention, the cut surface exists at the peripheral edge of the front and rear insertion portion, but does not exist on the inner peripheral surface of the front and rear insertion portion, and is a link material that is normally formed by rolling. The inner peripheral surface of the front and rear insertion portion is formed by the rolling surface (non-cut surface).

  In order to make the inner peripheral surface of the front and rear insertion part of each link a non-cut surface, for example, each link uses a plate-like link material and has a bottomed cylindrical part whose cross section has a front and rear insertion part shape. May be formed by removing all or part of the bottomed cylindrical portion after the drawing (first embodiment), and each link is a plate-like link material. After forming a through hole smaller than the front and rear insertion portion, the peripheral edge portion of the through hole may be bent (second embodiment). In this case, each link In addition, a reinforcing material having a through hole that fits into the edge bending portion may be fixed to be reinforced (third embodiment), and each link uses a plate-like link material. Then, after forming a through-hole smaller than the front-and-rear insertion part, fold the periphery of the through-hole. Also it is formed by processing good (Fourth Embodiment).

  Preferably, in the power transmission chain, 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 , Movably fitted in the front insertion portion of one link and fixed to the rear insertion portion of the other link, and further, a link row composed of a plurality of links having the same phase in the width direction in the traveling direction (front-rear direction) The three link units are arranged in parallel to form one link unit, and a plurality of link units composed of the three link rows are connected in the traveling direction.

  In this power transmission chain, 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").

  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.

  The pin is fixed to the front and rear insertion portion by, for example, fitting and fixing between the inner edge of the insertion portion and the outer peripheral surface of the pin by mechanical press-fitting. Alternatively, shrink fitting or cold fitting may be used. The first pin and the second pin are fitted to one insertion portion so as to face each other in the length direction of the chain, and either one of them is fitted and fixed to the peripheral surface of the insertion portion of the link. The fitting and fixing is preferably performed at the edges (upper and lower edges) of the portion orthogonal to the length direction of the insertion portion. By applying pre-tension after the fitting and fixing, an appropriate residual compressive stress is applied to the pin fixing portion (pin press-fitting portion) of the link evenly and accurately.

  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.

  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 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, the distance between sheave surfaces of the continuously variable transmission, that is, the wrapping radius of the chain is changed, and a continuously variable transmission can be performed with a 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 such as an automobile.

  According to the power transmission chain and the power transmission device of the present invention, since the cut surface does not exist on the inner peripheral surface of the front and rear insertion portion, a decrease in durability due to minute scratches during processing is prevented, and durability is improved.

  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.

  1 and 2 show the basic structure of a power transmission chain according to the present invention. The power transmission chain (1) is a front-rear insertion portion (12) (13) provided at a predetermined interval 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 fixed part (18) to which the pin (14) is fixed and the inter-piece (15) are movably fitted together Consists of.

  Each pin (14) is wider in the front-rear direction than the interpiece (15), and the upper and lower edges of the interpiece (15) have protruding edges (15a) extending to the respective pins (14) side. ) (15b).

  In FIG. 2, 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), and the distance between AB. Is the pitch.

  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).

  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 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, the cross section has an involute shape having a basic circle with a radius Rb and a center M, and the rolling contact surface (15c) 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 being in rolling contact (including some sliding contact) with the rolling contact surface (15c) of the interpiece (15). In the rear insertion part (13), the rolling contact surface (15c) 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 with rolling contact (including some sliding contact) on the surface (14a).

  This power transmission chain (1) holds the required number of pins (14) and interpieces (15) vertically on the assembly jig, and then press-fits one or several links (11) one by one. It is manufactured by doing. 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).

  The power transmission chain is used in the CVT. At this time, as shown in FIG. 8, each cone of the fixed sheave (2a) and the movable sheave (2b) of the pulley (2) having the pulley shaft (2e). The end surface of the pin (14) is in contact with the conical sheave surface (2c) (2d) of the pulley (2) while the end surface of the interpiece (15) is not in contact with the cylindrical sheave surface (2c) (2d). Power is transmitted by frictional force due to 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. In the driven pulley, although not shown, 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 is wound. When the diameter is reduced and the winding diameter of the drive pulley (2) is reduced, the winding diameter of the driven pulley is increased. As a result, a U / D state in which the winding diameter of the drive pulley (2) is minimum and the winding diameter of the driven pulley is maximum is obtained based on the state (initial value) where the gear ratio is 1: 1. In addition, an O / D state can be obtained in which the winding diameter of the drive pulley (2) is maximum and the winding diameter of the driven pulley is minimum.

  The link (11) shown in FIG. 2 can be obtained by pressing the plate-like link material (10) shown in FIG. 3 (a) having a predetermined thickness by rolling, and conventionally formed by punching. It had been. In the punching process, as shown in FIG. 3C, the inner peripheral surfaces of the front and rear insertion portions (12) and (13) of the link (11) are cut surfaces (fracture surfaces) indicated by C. Since the cut surface C tends to generate micro-scratches such as burrs, sag, and sheared surfaces, it is disadvantageous in terms of durability compared to the surface (rolled surface) S of the link material (10). Here, when the pin (14) and the interpiece (15) are press-fitted, there is a possibility that micro-scratches during the processing of the link (11) may become large.

  Therefore, in the link (11) of the power transmission chain (1) of the present invention, as shown in FIG. 3 (b), the cut surface C is placed on one of the peripheral surfaces of the front and rear insertion portions (12) and (13) (FIG. Then, the inner peripheral surface of the front and rear insertion portions (12) and (13) of the link (11) is formed by the rolling surface S of the link material (10).

  In order to form the inner peripheral surface of the front and rear insertion portions (12) and (13) of the link (11) with the rolled surface S of the link material (10), first, as shown in FIG. A plate-like link material (10) is formed by drawing so as to have a bottomed cylindrical portion (10a) whose cross section is in the shape of the front and rear insertion portion (12) (13) (FIG. 4 (a)), Thereafter, it can be obtained by removing all or part of the bottomed cylindrical part (10a) including the bottom part. By doing so, the cut surface C is not formed on the inner peripheral surface of the front and rear insertion portions (12) and (13) but on one surface (lower surface in the drawing) of the peripheral portion of the front and rear insertion portions (12) and (13). When the pins (14) and the interpiece (15) are press-fitted into the inner peripheral surfaces of the front and rear insertion portions (12) and (13), the possibility of scratches is substantially zero. When removing the bottomed cylindrical portion (10a), as shown in FIG. 4 (b), all the protruding portions may be removed during drawing, and as shown in FIG. 4 (c). A part of the protruding portion may be left during the drawing process. If it makes it like FIG.4 (b), the link (11) which made the shape completely the same as the past, and made only the inner peripheral surface of the front-and-rear insertion part (12) (13) non-cut surface (rolling surface) S will be obtained. As shown in FIG. 4 (c), the projecting edge portions (12a) and (13a) are formed on the peripheral edge portions of the front and rear insertion portions (12) and (13), so that the front and rear insertion portions (12) ( 13) Not only can the inner peripheral surface be a non-cut surface S, but also the peripheral portions of the front and rear insertion portions (12) and (13) can be made thicker, further improving the durability of the link (11). Can do.

  In order to obtain the link (11) in FIG. 4 (c), the drawing process is omitted and, as shown in FIG. It can also be obtained by forming a small through hole (10b) (for the thickness of the link material (10)) and subsequently bending the periphery of the through hole (10b). The link (11) shown in FIG. 5 (b) thus obtained is similar to the link (11) in FIG. 4 (c), and has a protruding edge ( By forming 12a) and 13a, not only the inner circumferential surface of the front and rear insertion portions 12 and 13 is a non-cut surface S but also the front and rear are compared with the link 11 of FIG. The peripheral portions of the insertion portions (12) and (13) can be thickened, and the durability of the link (11) can be further improved.

  As for the link (11) shown in FIG. 4 (c) and FIG. 5 (b), only the peripheral portion of the front and rear insertion portions (12) and (13) is thick, so the thickness of the entire link (11) is increased. Therefore, as shown in FIGS. 6 (a) and 6 (b), a reinforcing material (20) may be press-fitted. The reinforcing member (20) has a through hole (20a) that is one size larger than the portion including the front and rear insertion portions (12) and (13) of the link (11) and the column portion between them. By fitting the through hole (20a) to the protruding edge (12a) (13a) of the link (11), the combined link (11) and reinforcement (20) (link) has a uniform thickness. The link (11) shown in FIG. 1 can be replaced with the link (11) with the reinforcing member (20) without changing the design.

  In addition, as shown in FIG. 7, after forming a through-hole through which the front and rear insertion portions (12) and (13) are communicated by the same step as the step of forming the link (11) in FIG. It is assumed that the peripheral edge is bent (FIG. 7 (a)), and the protrusion amount of the protrusion (10c) at this time is larger than that of the link (11) of FIG. 5 (b). After the intermediate shape shown in FIG. 7 is obtained, the projecting portion (10c) is further folded back into a U shape so that the inner peripheral surfaces of the front and rear insertion portions (12) and (13) shown in FIG. A uniform thickness can be obtained without a reinforcing material. The link (11) in FIG. 7 (b) is different from the link (11) shown in FIGS. 1 and 2 in that the front and rear insertion portions (12) and (13) are in communication (no column portion). Although it is different, the link (11) in FIG. 7B can also be replaced with the link (11) shown in FIG. 1 without changing the design. By providing through holes corresponding to the front and rear insertion portions (12) and (13) at the stage of FIG. 7 (a), the link (11) of FIG. Is also possible.

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 the link and the pin. FIG. 3 is a cross-sectional view illustrating a link of a power transmission chain according to the present invention in comparison with a conventional one. FIG. 4 is a sectional view showing a first embodiment of the link of the power transmission chain according to the present invention. FIG. 5 is a sectional view showing a second embodiment of the link of the power transmission chain according to the present invention. FIG. 6 is a sectional view showing a third embodiment of the link of the power transmission chain according to the present invention. FIG. 7 is a cross-sectional view showing a fourth embodiment of the link of the power transmission chain according to the present invention. FIG. 8 is a front view showing a state in which the power transmission chain is attached to the pulley.

Explanation of symbols

(1) Power transmission chain
(2) Pulley
(2c) (2d) Conical sheave surface
(10) Link material
(10a) Bottomed cylindrical part
(10b) Through hole
(11) Link
(12) Front insertion part
(13) Rear insertion part
(14) Pin (1st pin)
(15) Interpiece (2nd pin)
(20) Reinforcement material

Claims (6)

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 power transmission chain, wherein the front and rear insertion portions of each link have an inner peripheral surface that is a non-cut surface.   Each link uses a plate-like link material to form a bottomed cylindrical part having a cross-sectional shape in the front and rear insertion part by drawing, and then removes all or part of the bottomed cylindrical part. The power transmission chain according to claim 1, wherein the power transmission chain is formed.   2. Each link is formed by using a plate-shaped link material to form a through hole smaller than the front and rear insertion portion and then edge-bending the through hole peripheral portion. Power transmission chain.   4. The power transmission chain according to claim 3, wherein a reinforcing material having a through hole that fits into the edge bending portion is fixed to each link.   2. Each link is formed by forming a through-hole smaller than the front-and-rear insertion portion using a plate-shaped link material, and then turning back the peripheral portion of the through-hole. 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 any one of claims 1 to 5.

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