JP5251346B2 - 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 a continuously variable transmission for an automobile, as shown in FIG. 6, a drive pulley (2) provided on the engine side having a fixed sheave (2a) and a movable sheave (2b), a fixed sheave (3b) and a movable sheave (3a) and a driven pulley (3) provided on the drive wheel side and an endless power transmission chain (1) spanned between them, and a movable sheave (2b) (3a) by a hydraulic actuator The chain (1) is clamped with hydraulic pressure by moving it toward and away from the fixed sheave (2a) (3b), and this clamping force makes contact between the pulley (2) (3) and the chain (1). It is known that a load is generated and torque is transmitted by the frictional force of the contact portion.

As a power transmission chain, 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 are provided, and the first pins and the second pins are relatively rolled and brought into contact with each other, whereby the links can be bent in the longitudinal direction. The thing is known (for example, patent document 1).
JP 2006-2784 A

  In the thing of the said patent document 1, noise reduction is aimed at by arranging two types of links from which length differs at random. However, in terms of weight, the weight of each link is substantially the same, and the weight per unit length (linear density) in the chain traveling direction can be regarded as uniform. The fact that the linear density is uniform means that there is only one string natural frequency under a certain condition. For this reason, when string vibration of the chain occurs, it is considered that noise at a specific frequency increases.

  An object of the present invention is to provide a power transmission chain and a power transmission device that suppress string vibration of the chain and thereby reduce noise and vibration.

The power transmission chain according to the present invention includes a plurality of links, a plurality of first pins, and a plurality of second pins, and the first pin and the second pin are relatively in rolling contact with each other, whereby the length of the links is increased. in the power transmission chain that is possible is the direction of bending, the traveling direction a plurality of locations of the chain, the weight load portions of the weight per unit length different from the reference portion is provided with a weight load portions The link which comprises comprises the protrusion part which fills the clearance gap between the links adjacent in a chain advancing direction, The weight is increased, It is characterized by the above-mentioned.

  “Weight non-uniform part” is not a non-uniform weight between a part having a reference link and a part having a link having a long pitch length when two types of links having different pitch lengths are randomly arranged. This is achieved by increasing the thickness of the link (the whole may be thickened, or only a part of the stepped link may be thickened). Instead of or in addition to increasing the thickness, the overall shape of the link may be increased, and the specific gravity of the link may be changed. Moreover, you may make it change not only a link but according to the shape and specific gravity of a pin.

  The natural frequency f of the string is defined as f = √ (T / ρ) / 2L, where L is the length of the string, T is the tension, and ρ is the weight per unit length. For example, when ρ is 1.1 times, f is 0.95 times, and when ρ is 1.2 times, f is 0.91 times. When f is 0.95 times, the effect of different string natural frequencies in the chain traveling direction becomes significant, so the weight ratio per unit length (weight of non-uniform weight portion / weight of reference portion) It is preferably 1.1 times or more, and more preferably 1.2 times or more.

  The power transmission chain is, for example, 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 the first and second pins, and the first pin and the second pin are in rolling contact with each other so that the links can be bent in the longitudinal direction. It is supposed to be.

  In the power transmission chain according to the present invention, for example, one unit (link) includes a first link row composed of a predetermined number of links, a second link row composed of a predetermined number of links, and a third link row composed of a predetermined number of links. As a unit, it is preferable to configure a chain by arranging a required number of link units in the chain traveling direction. In this case, the non-uniform weight portion can be obtained by configuring one or more of the link units with the above-described weight increase link.

  In the link unit, the number of links arranged in the width direction is all the same, and the first to third link rows each having eight links may be regarded as one link unit. For example, a link row of 5 links, a link row of 7 links, a link row of 8 links, and a link row of 8 links can be used as a link unit. There are cases in which two link rows (eight) and one link row having nine links are used as a link unit.

  A chain is configured by arranging the required number of such link units in the chain traveling direction. In this case, a gap is required between the links arranged in the chain traveling direction to avoid interference. This is a disadvantage in terms of suppressing the string vibration of the chain. Therefore, when forming the non-uniform weight portion, the protruding portion that fills the gap for avoiding interference between the links arranged in the chain traveling direction is integrated with the link facing through the gap so that the link is stepped. It is preferable.

  In this way, the frictional force between the links increases, and this frictional force becomes a resisting force against the string vibration of the chain, and the vibration can be attenuated. Thus, the damping effect of the string vibration of the chain can be increased. Here, “filling the gap” does not mean that the links are always in contact with each other, and the gap is not completely zero, but the frictional force becomes a resistance force to attenuate the string vibration of the chain. The case where there is a minute gap to the extent that can be performed is also included. The thickness of the protruding portion is the same as the thickness of the link (where the thickness of the thin portion of the link is t, and the thickness of the thick portion including the protruding portion is 2t). If necessary, one without a protruding portion is also used. The protruding portion may be provided on the front insertion portion side of the link, may be provided on the rear insertion portion side, may be provided on the inner side in the chain width direction, or may be provided on the outer side in the chain width direction. When providing the protruding portion, at least the front end portion and the rear end portion of the link remain thin (the same thickness as the reference link) in order to avoid interference with other links. The cross-sectional shape of the pin, the front and rear insertion portion and the contour shape of the link are the same in the non-uniform weight portion and the reference portion. The protruding portion is formed so as to increase the thickness of the peripheral portion of the front insertion portion or the rear insertion portion. As a result, the strength of the link is increased and the durability is improved.

  In the power transmission chain according to the present invention, at least one of the first pin and the second pin comes into contact with the pulley to transmit power by frictional force. In a chain in which one of the pins contacts the pulley, one of the first pin and the second pin is a pin that contacts the pulley when the chain is used in a continuously variable transmission ( In the following, the pin is referred to as “first pin” or “pin”, and the other is referred to as the pin that does not contact the pulley (interpiece or strip). "Peace").

  One of the first pin and the second pin is fixed to the front insertion portion of one link and is movably fitted to the rear insertion portion of the other link, and the other is the front insertion portion of the one link. It is preferable that it is movably fitted in and fixed to a rear insertion portion of another link.

  The pin is fixed to the pin fixing portion by, for example, fitting and fixing the inner edge of the pin fixing portion and the outer peripheral surface of the pin by mechanical press-fitting. Alternatively, shrink fitting or cold fitting may be used. The fitting and fixing is preferably performed at the edges (upper and lower edges) of the portion orthogonal to the length direction of the pin fixing portion. After the fitting and fixing, a pre-tension is applied in the pre-tension applying step, so that an appropriate and residual compressive stress is equally applied to the pin fixing portion (pin press-fitting portion) of the link.

  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.

  For example, the first pin and the second pin are formed as involute curved surfaces in which either one of the contact surfaces is a flat surface and the other contact surface is relatively rollable and movable. Moreover, you may make it each contact surface form a required curved surface for the 1st pin and the 2nd pin.

  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 continuously variable transmission using the power transmission chain described above, 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, whereby the distance between sheave surfaces of the continuously variable transmission, and hence the winding radius of the chain, is changed.

  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 for a vehicle such as an automobile.

  According to the power transmission chain of the present invention, since the weight non-uniform portion having a weight per unit length different from the reference portion is provided at a plurality of locations in the chain traveling direction, the natural frequency of the string depends on the position in the chain traveling direction. Even when the string vibration of the chain occurs, the noise at a specific frequency is suppressed from being increased, thereby reducing the noise and vibration.

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

  FIG. 1 shows a power transmission chain (1) according to the present invention, which includes a plurality of links (11) (21) (31), a plurality of pins (first pins) (14), and an interpiece (first piece). 2 pins) (15), and the first pin (14) and the second pin (15) are in rolling contact with each other, so that the length of the links (11) (21) (31) Bending in the vertical direction is possible. The part surrounded by the two-dot chain line is the weight non-uniform part (H), and the link (31) is thickened with respect to the other reference part (Q), and the weight is partially increased. ing. Further, the link indicated by reference numeral (21) has a longer pitch than the link indicated by reference numeral (11).

  Regarding the string vibration in such a power transmission chain (1), the natural frequency f of the string is f = √ (T / ρ) where L is the length of the string, T is the tension, and ρ is the weight per unit length. ÷ It is defined by 2L. If the string natural frequency f is constant, noise at this frequency may increase. The non-uniform weight portion (H) is configured such that the weight per unit length is different from the reference portion (Q) so that the natural frequency of the string varies depending on the position in the chain traveling direction.

  As shown in FIGS. 2 and 3, the reference portion (Q) and the non-uniform weight portion (H) are respectively provided with front and rear insertion portions (12) and (13) provided at predetermined intervals in the chain length direction. A plurality of links (11) having a pin (14) and an interpiece (15) for connecting the links (11) arranged in the chain width direction so as to be bendable in the length direction, and a reference portion (Q) The links (11) and (21) that make up the non-uniform portion have a uniform thickness. Multiple (4 types in total) (31) (32) (33) (34) are used.

  2 and 3, 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 interpiece (15) is opposed to the front side and the pin (14) is 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. In this embodiment, a link row having 5 links, a link row having 7 links, and a link row having 8 links are formed as one link unit.

  FIG. 4 shows the shapes of the reference link (11), pin (14) and interpiece (15) of uniform thickness. The stepped links (31), (32), (33), and (34) are provided with protrusions (31a), (32a), (33a), and (34a) to be described later, and the links (31), (32) ( The contour shapes of 33) and 34 and the shapes of the front and rear insertion portions (12) and (13) are the same as those of the reference link (11).

  As shown in FIG. 4, the front insertion part (12) of each link (11) includes an interpiece to which the pin movable part (16) and the interpiece (15) are 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.

  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.

  When connecting the links (11) aligned in the chain width direction, the front insertion part (12) of one link (11) (21) (31) (32) (33) (34) and the other link (11) The links (11) (21) (31) (32) (33) (34) overlap each other so that the rear insertion parts (13) of (21) (31) (32) (33) (34) correspond. Pin (14) is fixed to the rear insertion portion (13) of one link (11) (21) (31) (32) (33) (34) and the other link (11) (21) (31 ) (32) (33) (34) is movably fitted to the front insertion part (12), and the interpiece (15) is connected to one link (11) (21) (31) (32) (33) ( 34) is movably fitted to the rear insertion portion (13) and fixed to the front insertion portion (12) of the other links (11) (21) (31) (32) (33) (34). Then, the pin (14) and the interpiece (15) are relatively rolled and brought into contact with each other, so that the length direction between the links (11) (21) (31) (32) (33) (34) ( Bending in the front-rear direction is possible.

  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). In FIG. 4, 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.

  The power transmission chain (1) is used in the V-type pulley type CVT shown in FIG. 5, and at this time, 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 each conical sheave surface (2c) (2d) of However, power is transmitted by the frictional force caused by this contact.

  In the reference portion (Q) shown in FIG. 2, all the links (11) have a uniform thickness, and there is a gap (G1) between the links (11) arranged in the chain traveling direction (vertical direction in FIG. 2). ) (G2) (G3) exists. These gaps (G1), (G2), and (G3) are relatively disadvantageous to the occurrence of string vibration of the chain (1). Therefore, in the non-uniform weight portion (H) shown in FIG. 3, a stepped link having protrusions (31a) (32a) (33a) (34a) filling these gaps (G1) (G2) (G3). (31) (32) (33) (34) are used.

  For example, in FIG. 2, the link indicated by reference numeral (L1) is formed with a protruding portion (31a) for filling the gap indicated by (G1), which is the link indicated by reference numeral (31) in FIG. It has become. In FIG. 2, the link indicated by reference numeral (L2) is formed with a protrusion (33a) for filling the gap indicated by (G2), which is the link indicated by reference numeral (33) in FIG. It has become. In this way, the gap (G1) (G2) is formed on one of the opposing surfaces of the pair of links (11) facing in the chain width direction via the gap (G1) (G2) (G3). The projecting portions (31a) (32a) (33a) (34a) filling (G3) are integrally formed, so that the stepped links (31) (32) (33) constituting the non-uniform weight portion (H) are formed. ) (34) is formed.

  In FIG. 3, the stepped links (31), (32), (33), and (34) have a protrusion (31a) on the rear side in the chain traveling direction and on the left side in the chain width direction (31). In addition, there are protrusions (32a) on the front side in the chain traveling direction and on the left side in the chain width direction (32), those on the front side in the chain traveling direction and on the right side in the chain width direction (33a) and A total of four types (34) having a protrusion (34a) on the rear side in the chain traveling direction and on the right side in the chain width direction are used.

  This power transmission chain (1), after holding the required number of pins (14) and interpiece (15) vertically on the assembly jig, links (11) (21) (31) (32) ( 33) Manufactured by press-fitting (34) one by one or several at a time. This press-fitting is performed between the upper and lower edges of the pin (14) and the interpiece (15) and the upper and lower edges of the pin fixing part (18) and the interpiece fixing part (17). It is set to 0.005 mm to 0.1 mm. In this way, tension is applied (pre-tensioned) to the assembled chain (1).

  In the above power transmission chain (1), polygonal vibration is caused by repeated vertical movement of the pin, which causes noise, but the pin (14) and the interpiece (15) are relatively rolled and moved in contact. In addition, since the locus of the contact position between the pin (14) and the interpiece (15) with respect to the pin (14) is an involute of the circle, both the contact surfaces of the pin and the interpiece are arcuate surfaces. Compared to the case, vibration can be reduced and noise can be reduced. Further, when used in CVT, 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 surface (2c) of the pulley (2) ) (2d), the pin (14) hardly rotates, the friction loss is reduced, and a high power transmission rate is secured.

  Furthermore, the string non-uniformity (H) is provided for the string vibration of the chain (1), so that the natural frequency of the string varies depending on the position of the chain traveling direction, and the string vibration of the chain (1) occurs. Even in this case, it is possible to suppress the noise at a specific frequency from increasing. Moreover, in the non-uniform weight portion (H), the gaps (G1), (G2), and (G3) that exist between the links (11) with a uniform thickness are formed in the stepped links (31), (32), (33), and (34). By being filled with the formed protrusions (31a) (32a) (33a) (34a), the string vibration of the chain (1) is suppressed, thereby further reducing noise and vibration. .

  In the above formula f = √ (T / ρ) / 2L, for example, when ρ is 1.1 times, f is 0.95 times, and when ρ is 1.2 times, f is 0.91. Double. When f is 0.95 times, the effect of different string natural frequencies in the chain traveling direction becomes remarkable. Therefore, in the weight non-uniform portion (H), the weight ratio per unit length (weight non-uniform portion (H ) / Weight of the reference portion (Q)) is preferably 1.1 times or more, and more preferably 1.2 times or more.

FIG. 1 is a side view showing an embodiment of a power transmission chain according to the present invention. FIG. 2 is an enlarged plan view showing the configuration of the reference portion of the power transmission chain according to the present invention. FIG. 3 is an enlarged plan view showing the configuration of the non-uniform weight portion of the power transmission chain according to the present invention. FIG. 4 is an enlarged side view of the main part of FIG. 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) (21) (31) (32) (33) (34) Link
(12) Front insertion part
(13) Rear insertion part
(14) Pin (1st pin)
(15) Interpiece (2nd pin)
(31a) (32a) (33a) (34a) Projection
(H) Uneven weight part
(Q) Standard part

Claims (2)

A plurality of links, a plurality of first pins, and a plurality of second pins are provided, and the first pins and the second pins are relatively rolled and brought into contact with each other, whereby the links can be bent in the length direction. Power transmission chain
Weight non-uniform parts where the weight per unit length is different from the standard part are provided at multiple points in the direction of travel of the chain ,
The power transmission chain is characterized in that the weight of the link constituting the non-uniform weight portion is increased by forming a protrusion that fills a gap between adjacent links in the chain traveling direction . A power transmission chain comprising: a first pulley having a conical surface sheave surface; a second pulley having a conical surface sheave surface; and a power transmission chain spanned between the first and second pulleys. There claim 1 Symbol placement of the power transmission device.

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