JP2014009785A - Power transmission chain and power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the strong sliding between a sliding part in a link and a first pin or a second pin, and thereby to improve the durability of a power transmission chain.SOLUTION: A longitudinally middle part of a first pin 14 is convexly curved outward in the chain radial direction, and a longitudinally middle part of a second pin 15 is convexly curved inward in the chain radial direction, which prevents the strong sliding between a sliding part in a link 11 and the first pin or the second pin, and thereby the durability of a power transmission chain is improved.

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 power transmission device such as a continuously variable transmission of an automobile, a primary pulley having a conical sheave surface, a secondary pulley having a conical sheave surface, and a power transmission wound around the primary pulley and the secondary pulley Some have a chain.

  As a power transmission chain, a chain including a plurality of links and a plurality of first pins and a plurality of second pins that connect the plurality of links so as to be bent is known (Patent Document 1).

  A front insertion portion and a rear insertion portion through which the pin is inserted are formed in the first pin and the second pin, respectively. Then, the links arranged in the chain width direction are connected by the plurality of first pins and the plurality of second pins arranged in the front-rear direction so that the front insertion part of one link corresponds to the rear insertion part of the other link. Yes.

  The front insertion part has a fixed part to which one of the first pin and the second pin is fixed, and a sliding part into which the other is slidably fitted. The rear insertion portion has a sliding portion that is overlaid on the fixing portion of the front insertion portion, and a fixing portion that is overlaid on the sliding portion of the front insertion portion.

  As shown in FIG. 6, when the power transmission chain (1) is attached to the continuously variable transmission (10), the first pin (14) is formed on the fixed sheave (2a) and the movable sheave (2b). It is sandwiched between the conical sheave surfaces (2c) (2d). By this clamping, power is transmitted between the power transmission chain (1) and the pulley (2).

  Here, when the first pin (14) is sandwiched between the fixed sheave (2a) and the movable sheave (2b) of the pulley (2), as shown in FIG. 6, the length of the first pin (14) The central portion in the vertical direction is deformed in a direction approaching the pulley shaft (2e) (convex shape on the inner diameter side in the chain radial direction). Patent Document 1 proposes a link shape suitable for preventing contact with the pulley shaft (2e).

JP 2009-222106 A

  In the above-described conventional power transmission chain, when the central portion in the length direction of the first pin is deformed into a convex shape on the radially inner side of the chain, the strength of sliding between the first pin and the link disposed in the central portion is increased. The sliding strength between the first pin and the link disposed at the end is different. Also, the sliding strength between the second pin and the link disposed at the central portion is different from the sliding strength between the second pin and the link disposed at the end portion. For this reason, a strong sliding mark may occur in the sliding portion of the link that slides strongly with the first pin or the second pin. If a strong sliding mark is generated on the link, the link may be broken starting from the sliding mark.

  An object of the present invention is to improve the durability of the power transmission chain by preventing the sliding portion of the link and the first pin or the second pin from sliding strongly.

  The present invention is a power transmission chain that is sandwiched by a pair of sheave surfaces in each of a first pulley and a second pulley each having a pair of conical sheave surfaces facing each other. Each of the plurality of links arranged in the direction of travel of the chain and the first insertion portion of one link and the second insertion portion of the other link correspond to each other. A connecting member that bends the links arranged in the chain width direction orthogonal to the first insertion portion and the second insertion portion so as to be bendable, and the connection members roll together. A first pin and a second pin that are in contact with each other, wherein the second pin is made shorter than the first pin, and the first pin is a pair of sheave surfaces of the first pulley and the second pulley, respectively. Sandwiched between The first insertion portion has a fixed portion to which one of the first pin and the second pin is fixed, and a sliding portion into which the other is slidably fitted, and the second insertion portion is The first pin has a sliding portion that is overlaid on the fixed portion, and a fixed portion that is overlaid on the sliding portion of the first insertion portion, and the first pin has a central portion in the length direction. The warp which becomes convex on the outer side in the chain radial direction is given.

  According to the power transmission chain of the present invention, when the pinching force of the pulley acts on the first pin, the first pin is deformed so as to cancel the warpage, and the first pin approaches a linear state, and the first pin The difference between the warp occurring at the second pin and the warp occurring at the second pin is reduced. Thereby, the sliding part of the link and the first pin or the second pin are prevented from sliding strongly, and the durability of the power transmission chain is improved.

FIG. 1 is a plan view showing a part of a first embodiment of a power transmission chain according to the present invention. FIG. 2 is an enlarged side view showing the shapes of the link, the first pin, and the second pin. FIG. 3 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 4 is a front view schematically showing the main part of the first embodiment of the power transmission chain, where (a) shows a state where the pulley clamping force is not acting, and (b) shows the pulley. The state where the clamping force is applied is shown. FIG. 5 is a front view schematically showing the main part of the second embodiment of the power transmission chain, in which (a) shows a state where the pulley clamping force is not acting, and (b) shows the pulley. The state where the clamping force is applied is shown. FIG. 6 is a front view exaggeratingly showing a state in which the power transmission chain is held between pulleys.

  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. The right side of FIGS. 1 and 2 is before the direction of travel, and the left side is after the direction of travel.

  FIG. 1 shows a part of the power transmission chain of this embodiment. The power transmission chain (1) has a plurality of links having a front insertion part (first insertion part) (12) and a rear insertion part (second insertion part) (13) provided at predetermined intervals in the chain traveling direction. (11), and a plurality of first pins (14) and a plurality of second pins (15) that connect the plurality of links (11) in a bendable manner. The second pin (15) is shorter than the first pin (14), and both of them are in contact with the second pin (15) arranged on the front side and the first pin (14) arranged on the rear side. Yes. The pair of the first pin (14) and the second pin (15) corresponds to a connecting member.

  In the power transmission chain (1), three link rows (3a) (3b) (3c) 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 (3). A plurality of link units (3) composed of the three link rows (3a), (3b) and (3c) are connected in the traveling direction. In this embodiment, the link row (3a) with nine links and the two link rows (3b) (3c) with eight links constitute one link unit (3).

  As shown in FIG. 2, the front insertion part (12) of the link (11) has a sliding part (16) in which the first pin (14) is slidably fitted and a second pin (15) fixed. And a fixed portion (17). Further, the rear insertion portion (13) of the link (11) includes a fixing portion (18) to which the first pin (14) is fixed and a sliding portion (2) in which the second pin (15) is slidably fitted. 19).

  The first pin (14) is wider in the front-rear direction than the second pin (15), and the upper and lower edges of the second pin (15) protrude toward the first pin (14). Edges (15a) (15b) are provided.

  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) Overlapping each other. The first pin (14) is fixed to the rear insertion portion (13) of one link (11) and is slidably fitted to the front insertion portion (12) of the other link (11). The second pin (15) is slidably 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 first pin (14) and the second pin (15) are relatively rolled and brought into contact with each other, whereby the links (11) can be bent.

  At the boundary between the fixed part (18) of the rear insertion part (13) and the sliding part (19), the upper and lower concave arcuate guide parts (19a) and (19b) of the sliding part (19) are connected and fixed respectively. Upper and lower convex arc-shaped holding portions (18a) and (18b) for holding the first pin (14) fixed to the portion (18) are provided. Similarly, at the boundary portion between the fixed portion (17) of the front insertion portion (12) and the sliding portion (16), the upper and lower concave arcuate guide portions (16a) and (16b) of the sliding portion (16) are provided. Upper and lower convex arc-shaped holding portions (17a) and (17b) for holding the second pin (15) fixed to the fixed portion (17) are provided.

  The locus of the contact position between the first pin (14) and the second pin (15) with respect to the first pin (14) is an involute of a circle. In this embodiment, the rolling contact surface (14a) of the first pin (14) is an involute curve, and the rolling contact surface (15c) of the second pin (15) is a flat surface (the cross-sectional shape is a straight line). . As a result, when each link (11) moves from the straight region of the chain (1) to the curved region or from the curved region to the straight region, the first pin (14) and the second pin (15) are relatively Rolling contact movement. Specifically, in the front insertion portion (12), the rolling contact surface (14a) of the first pin (14) is in contact with the second pin (15) with respect to the second pin (15) in a fixed state. It moves in the sliding part (16) while rolling (including some sliding contact) on the surface (15c). Further, in the rear insertion portion (13), the second pin (15) has its rolling contact surface (15c) as the first pin (with respect to the first pin (14) fixed in the sliding portion (19)). The rolling contact surface (14a) of 14) moves while rolling (including some sliding contact).

  The link (11) is made of, for example, spring steel or carbon tool steel. The material of the link (11) is not limited to spring steel or carbon tool steel, but may of course be other steel such as bearing steel. In the link (11), the front and rear insertion parts (12) and (13) may be independent through holes (links with columns), and the front and rear insertion parts (12) and (13) have one through hole (no columns). Link). As the material of the first pin (14) and the second pin (15), appropriate steel such as bearing steel is used.

  The power transmission chain (1) is manufactured by sequentially press-fitting a required number of links (11) after holding a required number of first pins (14) and second pins (15). The press-fitting is performed between the upper and lower edge portions of the first pin (14) and the fixed portion (18) of the rear insertion portion (13) of the link (11) and the upper and lower edge portions and the front insertion portion (second pin (15)). It is carried out between the upper and lower edges of the fixing part (17) of 12).

  The power transmission chain (1) is used in a continuously variable transmission (10) as a power transmission device. As shown in FIG. 3, the continuously variable transmission (10) includes a pair of pulleys (only one pulley is shown) (2), a power transmission chain (1) wound around both pulleys (2), It has.

  The pulley (2) includes a fixed sheave (2a) fixed to the pulley shaft (2e) and a movable sheave (2b) supported on the pulley shaft (2e) so as to be movable in the axial direction. The fixed sheave (2a) and the movable sheave (2b) have conical face-like sheave surfaces (2c) and (2d) that face each other.

  Both end surfaces of the first pin (14) are sandwiched between a pair of opposed sheave surfaces (2c) (2d) of the pulley (2), and both end surfaces of the first pin (14) and each sheave surface (2c) ) (2d), the power is transmitted between the power transmission chain (1) and the pulley (2). The movable sheave (2b) is pressed toward the fixed sheave (2a) by a hydraulic actuator (not shown), so that a clamping force for clamping the power transmission chain (1) is applied to the pulley (2). It is done. Both end surfaces of the second pin (15) are not in contact with the sheave surfaces (2c) and (2d) of the pulley (2).

  In FIG. 3, when the movable sheave (2b) of the pulley (2) at the position indicated by the solid line is moved closer to or away from the fixed sheave (2a), the power transmission chain (1) is wound around the pulley (2). The diameter is large when approaching and is small when separated, as indicated by the chain line in FIG.

  In the other pulley (not shown) of the pair of pulleys (2), the fixed sheave is disposed on the opposite side in the axial direction from the illustrated fixed sheave (2a) with the power transmission chain (1) in between. Yes. The movable sheave moves in the opposite direction to the movable sheave (2b) of the pulley (2) shown. As a result, the gear ratio of the continuously variable transmission (10) changes steplessly.

  When the number of links is different between the link rows (3a), (3b), and (3c) as in the power transmission chain (1) shown in FIG. The load sharing of 11) becomes large, and there is a possibility that the fixed portions (17) and (18) of the links (11) of the link rows (3b) and (3c) with a small number of links will be damaged. Therefore, in order to improve the durability of the link (11), it has been considered that the durability of the fixing portions (17) and (18) should be improved. In the fixed part (17) (18), the pin (14) (15) is press-fitted to increase the stress, but in the sliding part (16) (19), the pin (14) (15) It is considered that the stress is small. For this reason, conventionally, little consideration has been given to damage in the sliding portions (16) and (19).

  The clearance between the first pin (14) and the sliding portion (16) and the clearance between the second pin (15) and the sliding portion (19) are preferably reduced in order to reduce vibration. However, if this gap is made too small, the first pin (14) and the sliding portion (16) or the second pin ( 15) and the sliding part (19) may come into strong contact. Therefore, the clearance between each pin (14) (15) and each sliding portion (16) (19) is set in consideration of the force acting in the pretensioning step and high speed rotation.

  When the power transmission chain (1) is wound around the pulley (2), the first pin (14) sandwiched between the sheave surfaces (2c) (2d) of the pulley (2) is in the length direction. Is elastically deformed so as to protrude inward in the chain radial direction so that the central portion of the shaft approaches the pulley shaft (2e). Since the second pin (15) is shorter than the first pin (14), the deformation is smaller than that of the first pin (14). As the first pin (14) is elastically deformed, the link rows (3a), (3b), and (3c) are arranged so that the central portion in the length direction as a whole approaches the pulley shaft (2e) when viewed from the chain traveling direction. It is deformed so as to protrude inward in the radial direction of the chain. That is, the relative position of each pin (14) (15) and the sliding portion (16) (19) of the link (11) changes, and each pin (14) (15) and the sliding portion (16) ( 19) may come into strong contact. In this case, there is a possibility that a sliding mark is generated in the sliding portions (16) and (19), and the link (11) is broken starting from the sliding mark.

  Therefore, in this power transmission chain (1), the first pin (14) shown in FIG. 6 protrudes inward in the chain radial direction so that the central portion in the length direction (extending direction) approaches the pulley shaft (2e). In response to the elastic deformation (warping occurs), the first pin (14) is provided with a convex warp in the direction away from the pulley shaft (2e) in advance, that is, radially outward of the chain. Yes.

  FIG. 4 shows the first pin (14) and the second pin (15) of the first embodiment. As shown in FIG. 4A, the first pin (14) has a warp in which the central portion in the length direction protrudes outward in the radial direction of the chain in a state where the clamping force from the pulley (2) does not act. Has been granted. In this case, when the clamping force from the pulley (2) is applied, the first pin (14) is deformed inward in the chain radial direction as shown in FIG. , The warpage is offset and becomes linear. The amount of deformation of the second pin (15) is smaller than that of the first pin (14), and the second pin (15) is substantially linear. Since the link (11) fixed to the first pin (14) becomes linear according to the deformation of the first pin (14), the amount of change in the relative position between the second pin (15) and the link (11). Becomes smaller. Therefore, the possibility that the second pin (15) and the sliding portion (19) of the link (11) are in strong contact with each other is reduced.

  FIG. 5 shows the first pin (14) and the second pin (15) of the second embodiment. As shown in FIG. 4A, the first pin (14) has a warp in which the central portion in the length direction protrudes outward in the radial direction of the chain in a state where the clamping force from the pulley (2) does not act. Has been granted. Further, the second pin (15) is provided with a warp in which the central portion in the length direction is convex inward in the chain radial direction. The warpage of the first pin (14) is smaller than that of the first embodiment, and when the clamping force from the pulley (2) is large, as shown in FIG. The first pin (14) is deformed in a direction in which the central portion in the length direction protrudes inward in the chain radial direction, exceeds the linear shape, and the central portion in the length direction protrudes inward in the chain radial direction. It becomes the state that becomes. Since the second pin (15) is not clamped by the pulley (2), the amount of deformation is smaller than that of the first pin (14), and the central part in the length direction is kept convex inward in the chain radial direction. To do. The link (11) fixed to the first pin (14) is in a state in which the central portion in the length direction becomes convex inward in the chain radial direction in accordance with the deformation of the first pin (14). The amount of change in the relative position between 15) and the link (11) becomes small. Therefore, the possibility that the second pin (15) and the sliding portion (19) of the link (11) are in strong contact with each other is reduced.

  According to the first and second embodiments, when the clamping force from the pulley (2) is applied, the first pin (14) is deformed in a direction in which the applied warpage is canceled, and approaches a linear shape. . As a result, the strength of sliding between the first pin (14) and the link (11) disposed in the central portion, and the distance between the first pin (14) and the link (11) disposed at the end portion. The difference with the sliding strength at is small. Further, the first pin (14) is deformed so that the state of warpage approaches the second pin (15), and there is a difference between the warp generated in the first pin (14) and the warp generated in the second pin (15). Get smaller. As a result, the sliding strength between the second pin (15) and the link (11) disposed in the center portion and the distance between the second pin (15) and the link (11) disposed at the end portion are reduced. The difference with the sliding strength in the case is also reduced. Therefore, the link (11) does not slide strongly with either the first pin (14) or the second pin (15), and the durability of the power transmission chain (1) is improved.

  Preferably, both the first pin (14) and the second pin (15) are warped as in the second embodiment. By doing so, the magnitude of the warpage can be reduced, the difference from the conventional one can be reduced, and demerits due to the warpage can be prevented. For example, when the first pin (14) has a middle convex shape so that the first pin (14) is in a straight line state at the maximum clamping pressure, the first pin can be obtained at a low clamping pressure. Since the pin (14) does not sufficiently follow the second pin (15), the surface pressure varies in the chain width direction. However, since the absolute value of the surface pressure is low in this state, the durability of the chain is not affected.

  In the first to third embodiments, the warp of the first pin (14) and the second pin (15) (the chain radial direction between the center portion of the pin length direction and both end portions of the pin) The distance) is, for example, 0.01 mm to 0.1 mm. The warpage in each figure is exaggerated. Assuming that the amount of warping of the linear first pin (14) is 0.1 mm when the clamping force is maximum, the amount of warping in each embodiment does not have to be the same as this, and is 0.01 mm or more. The above effects can be obtained.

(1): Power transmission chain, (2): Pulley, (2c) (2d): Sheave surface, (11): Link, (12): Front insertion part (first insertion part), (13): Rear insertion Part (second insertion part), (14): first pin, (15): second pin, (16): sliding part, (17): fixing part, (18): fixing part, (19): Sliding part

Claims (3)

A power transmission chain that is sandwiched between the first sheave surface and the second pulley each having a pair of conical sheave surfaces facing each other, and the second pulley,
A plurality of links each having a first insertion portion and a second insertion portion and arranged in a chain traveling direction;
The links inserted in the chain width direction perpendicular to the chain traveling direction so that the first insertion part of one link and the second insertion part of the other link correspond to each other, the first insertion part and the second A connecting member that is connected to the insertion portion so as to be bent by being fitted to the insertion portion;
With
The connecting member includes a first pin and a second pin that are in rolling contact with each other,
The second pin is made shorter than the first pin, and the first pin is sandwiched between the pair of sheave surfaces of the first pulley and the second pulley,
The first insertion portion has a fixed portion to which one of the first pin and the second pin is fixed, and a sliding portion into which the other is slidably fitted, and the second insertion portion is A sliding portion that is superimposed on the fixed portion of the first insertion portion; and a fixing portion that is superimposed on the sliding portion of the first insertion portion,
A power transmission chain in which a warp in which a central portion in a length direction is convex outward in a chain radial direction is given to a first pin.   The power transmission chain according to claim 1, wherein the second pin is warped such that a central portion in the length direction is convex inward in the chain radial direction.   A first pulley having a conical sheave surface, a second pulley having a conical sheave surface, and a power transmission chain wound around the first pulley and the second pulley. A power transmission device comprising: a power transmission chain according to claim 1.

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