JP5211345B2 - Power transmission chain and power transmission device - Google Patents

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

  This type of power transmission chain is manufactured, for example, by holding a required number of pins vertically and then press-fitting links one by one or several at a time. The links are press-fitted to a predetermined dimensional position by position control so that a minute gap exists between adjacent ones of the links arranged in a row. The size of the gap is preferably small in terms of securing a frictional force that serves as a deterrent when string vibration of the chain occurs. However, if the gap is reduced, the frictional resistance between the links increases and the chain increases. There is a possibility that the rotational torque of will become too large.

  Assembling with the above position control has the advantage of high efficiency, but since the link thickness varies during rolling, the link position is controlled after setting the gap to a certain value. Then, gaps vary due to variations in the thickness of the links.

  An object of the present invention is to provide a power transmission chain and a power transmission device that can be press-fitted by position control with high assembly efficiency and are less susceptible to variations in link thickness.

  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 addition, in the power transmission chain in which the link is fixed to each pin at a predetermined position, the gap between the links adjacent to each other in the chain width direction is set with at least two types of gaps. To do.

  “Gap” means a gap at the time of design when there is no variation in the thickness of the link. The gap between the links is set by setting the link position at the time of fixing (press-fitting) the link to the pin as a predetermined position (position control).

  In the conventional power transmission chain, the size of the gap is one type and is the same everywhere, whereas in the power transmission chain according to the present invention, the size of the gap is two or more types. As a result, the vibration damping effect due to the frictional force between the links can be reliably obtained at the places where the gap is small, and the friction resistance between the links is large even when the link thickness varies at the places where the gap is large. It is prevented from becoming too much.

  For example, in a chain, 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 in the traveling direction. It is formed by connecting multiple. The number of links arranged in the width direction is not all the same, but the number of links in each link row is made large and small, for example, the number of links is 2 m (m: natural number) (eight as an example) 2 link rows and one link row having 2m + 1 links (9 as an example) may be used as one link unit. In this case, when considering in the chain width direction corresponding to one pin, for each link of the 2m + 1 link row, on both sides, the links face each other with a predetermined gap, and each link of the 2m link row The links are arranged so that the links are opposed to each other through a predetermined gap on one side and the links are opposed to each other on the other side with a predetermined thickness + the predetermined gap. Thus, with respect to the arrangement between the links adjacent in the chain width direction, the first arrangement in which the links are opposed from both sides via the front or rear half of the predetermined link and the front or rear half of the predetermined link If there is a second array in which the links are opposed from only one side, the gap A between the links of the first array in which the links are opposed to each other through a predetermined gap on both sides is reduced. The above effect can be made more effective by increasing the gap B (A <B) between the links of the second array in which the links are opposed to each other via a predetermined gap only on one side. it can.

  The two types of gaps are not limited to those described above. For example, links arranged in the chain width direction are divided into an outer portion and a central portion, and one of them is made smaller and the other is a gap. It may be large.

  The smaller gap A may be zero. Further, the larger gap B is preferably set to B−A = 3 × α, where α is a variation in the thickness of the link so that the gap does not become a negative gap even when the thickness of the link varies. The gap A is preferably 0.01 mm or less.

  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.

  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 the pin is fixed to the rear insertion portion of another link, and the pin is fixed to the front and rear insertion portion by, for example, fitting between the inner edge of the insertion portion and the outer peripheral surface of the pin by mechanical press-fitting. Although fixed and fixed, instead of this, 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. After the fitting and fixing, a pretension is applied in the pretension applying step, so that an appropriate residual compressive stress is uniformly and accurately applied to the pin fixing portion (pin press-fitting portion) of the link.

  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, by using two types of gaps, a sufficient frictional force between the links can be obtained at a part where the gap is small, and a part where the gap is large. In this case, even if the thickness of the link varies, the variation is absorbed and a gap of a predetermined amount or more is secured. As a result, the frictional resistance between the links becomes an appropriate value, and the effect of damping the string vibration of the power transmission chain can be obtained with certainty, and the rotation unevenness due to the excessive negative clearance is less likely to occur.

  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 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.

  The chain (1) has a link row (R1) (R2) (R3) composed of a plurality of links in the same phase (in the vertical direction in FIG. 1) in the chain traveling direction in the traveling direction (left and right direction in FIG. 1). Three link units are arranged to form one link unit, and a plurality of link units composed of the three link rows (R1), (R2), and (R3) are connected in the traveling direction (left-right direction in FIG. 1). In this embodiment, the link row (R1) having nine links and the two link rows (R2) (R3) having eight links are used as one link unit. The links (11) of each link row (R1), (R2), and (R3) are arranged so as to be symmetric with respect to the center in the chain width direction (a line extending left and right in the vertical center in FIG. 1).

  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). For example, 0.003 mm to 0.05 mm.

  FIG. 3 shows a press-fitting device used in the method for manufacturing a power transmission chain according to the present invention. In the following description, the top and bottom refer to the top and bottom of FIG.

  The press-fitting device (40) includes a disk-shaped holding jig (43) having a required number of pin insertion holes (44) into which one end of the pin (14) and the interpiece (15) can be inserted, and each link (11 ) And a pressing jig (45) for pushing the pin (14) and the interpiece (15) to predetermined positions.

  The pin insertion hole (44) of the holding jig (43) has a bottom, and the bottom surface of the holding jig (43) is stepped so that the end surface of the pin (14) protrudes beyond the end surface of the interpiece (15). Yes. The cross-sectional shape of the pin insertion hole (44) is almost the same as that of the front and rear insertion portions (12) and (13) of the link (11), and the pin (14) and the interpiece (15) can be inserted and removed. The fitting is such that the inserted pin (14) and the interpiece (15) are movable.

  The pressing jig (45) is for press-fitting the links (11) one by one, and the pressing jig (45) has a substantially rectangular plate shape whose size is slightly larger than that of the link (11). ) Is provided with a pin insertion hole (46) penetrating therethrough. The cross-sectional shape of the pin insertion hole (46) is substantially the same shape as the front and rear insertion portions (12) and (13) of the link (11), and when the pressing jig (45) is moved downward, 14) and the interpiece (15) are in contact with each other but do not interfere with each other.

  The holding jig (43) is rotatable around the vertical axis.First, all the pins (14) and interpieces (15) used in the chain (1) are placed in the pin insertion holes (44). Inserted. Next, the link (11) is disposed at the upper end of the pin (14) and the interpiece (15), and the pressing jig (45) is lowered.

  The lowering amount of the pressing jig (45) is not a close contact between the first layer link (11) and the second layer link (11), but a predetermined amount of gap between the adjacent layer links (11). Are controlled (position control). That is, the press-fitting position of the link (11) is set so that the link (11) is stacked with the distance between the links (11) being an interval of the thickness of the link (11) + the gap. However, since the thickness of the link (11) varies, when the actual thickness of the link (11) is large, the gap is reduced accordingly. In the chain (1) shown in FIG. 1, a total of 25 links (11) are overlapped. Therefore, even if the thickness variation of the link (11) is 5 μm, the 25th layer link (11 ) Is deviated by 0.125 mm from the design position. Assembling by position control is good in assembling efficiency, but it is difficult to manage the gap between the links (11) in consideration of variations in the thickness of the links (11).

  In order to cope with variations in the thickness of the link (11), in the power transmission chain according to the present invention, as shown in FIG. 4, two types of A and B having different sizes are set as the gaps between the links (11). ing.

  FIG. 4 is an enlarged schematic view of the arrangement of links (11), showing the first to fifteenth layers of each link row (R1) (R2) (R3) in FIG. In the figure, the link (L1) of the link row (R1) with nine links is (3 × n + 1) layers (1, 4, 7, 10, 13, 16, 19, 22, and 25th layers). Placed in position. The link (L2) of one (R2) of the link row having eight links is the first half (9) of the links (L1) of the nine link rows (R1) by the latter half (left half in the figure). The link (L3) in the other (R3) of the link row with 8 links is arranged with 9 links in the front half (right half in the figure). The second half (the left half in the figure) of the link (L1) in the row (R1) is arranged so as to be sandwiched from both sides. As a result, with regard to the arrangement between the links (L1) (L2) (L3) adjacent in the chain width direction, the links (L2) (L3) are opposed from both sides via the front or rear half of the predetermined link (L1). There is a first array P and a second array Q in which the link (L1) faces only from one side in front of or in the latter half of the predetermined links (L2) and (L3).

  Focusing on these two arrays P and Q, the gap A between the predetermined link (L1) and the links (L2) (L3) on both sides thereof in the first array P is relatively small, and the second array Q The gap B between the predetermined link (L2) (L3) and the link (L1) on one side thereof is relatively large.

  Here, assuming that α is a variation in the thickness of the link, B−A = 3 × α, and the smaller gap A including 0 is set to 0.01 mm or less.

  According to this power transmission chain (1), the two sizes of the gap are set as described above, so that the link (L1) of nine link rows (R1) and the link (L1) are adjacent to each other via the gap A. The frictional force between the matching links (L2) and (L3) can be a resistance force to attenuate the vibration. Then, any one of the links (L2) and (L3) adjacent to the link (L1) of the nine link rows (R1) via the gap A is adjacent to the link (L1) (L2) via the gap B. ) (L3), this gap B becomes a buffer zone, and an overnegative gap (excessive contact pressure) is generated between the adjacent links (L1), (L2), and (L3) via the gap A. This prevents wear on the links (L1), (L2), and (L3), prevents rotation unevenness due to over-negative clearance, and prevents the transmission efficiency of the chain (1) from being reduced. The

  The power transmission chain is used in the CVT. At this time, as shown in FIG. 5, 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 (3), although not shown in the drawing, 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 When the winding diameter of (3) decreases and the winding diameter of the drive pulley (2) decreases, the winding diameter of the driven pulley (3) increases. As a result, the gear ratio is 1: 1, the U / D state where the drive pulley (2) has the smallest winding diameter and the driven pulley (3) has the largest winding diameter, and the drive pulley (2). The O / D state in which the winding diameter of the driven pulley (3) is the smallest and the winding diameter of the driven pulley (3) is the smallest is obtained.

  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 curve, the rolling contact surfaces of the pin and the interpiece are both circular arc surfaces. Compared to the case, vibration can be reduced and noise can be reduced. And, when used in CVT, string vibration is suppressed by the existence of an appropriate gap between the links (11) (L1) (L2) (L3) adjacent in the chain width direction, and even more. 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 side view of the main part of FIG. FIG. 3 is a vertical sectional view showing a press-fitting device used in the method of manufacturing a power transmission chain according to the present invention. FIG. 4 is a diagram schematically showing a gap between links of the power transmission chain 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.

Explanation of symbols

(1) Power transmission chain
(2) (3) Pulley
(2c) (2d) Conical sheave surface
(11) (L1) (L2) (L3) link
(12) Front insertion part
(13) Rear insertion part
(14) Pin (1st pin)
(15) Interpiece (2nd pin)

Claims (5)

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 so that the links can be bent in the longitudinal direction, and the link is in a predetermined position. In the power transmission chain fixed to each pin in
A power transmission chain characterized in that at least two kinds of gaps are set with respect to a gap between adjacent links in the chain width direction.   Regarding the arrangement between the links adjacent in the chain width direction, the first arrangement in which the links are opposed from both sides through the front or rear half of the predetermined link, and the link from only one side to the front or rear half of the predetermined link And the second array facing each other, the gap between the predetermined link in the first array and the links on both sides thereof is defined as A, the predetermined link in the second array and the link on one side thereof The power transmission chain according to claim 1, wherein the clearance is B and A <B.   The power transmission chain according to claim 2, wherein α is set to be B−A = 3 × α, where α is a variation in the thickness of the link.   4. The power transmission chain according to claim 2, wherein the smaller gap A is set to 0.01 mm or less including zero.   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 any one of claims 1 to 4.

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