JP2007255544A - Power transmission chain and power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission chain and a power transmission device capable of reducing noise and eliminating an impression and a friction trace caused by increase in amount of relative travel of links and a pin by using a plurality of kinds of links having different pitch lengths to improve the durability of the links. <P>SOLUTION: This power transmission chain 1 includes at least two kinds of links 21, 31 having different pitch lengths. Pin abutting parts 31a, 31b abutted on a corresponding pin 14 or inter piece 15 to regulate further relative travel of the pin 14 or the inter piece 15 when the link 21 exceeds the maximum amount of bending set in advance by adjusting the fore-and-aft length of the link 31 in such a way that its front face is abutted on the inter piece 15 in the link 21 positioned on a front side and its rear face is abutted on the pin 14 in the link 21 positioned on a rear side are formed on the link 31 positioned at the center among three links 21, 31, 21 lined up in the front and the rear. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power transmission chain, and more particularly to a power transmission chain and a power transmission device suitable for a continuously variable transmission (CVT) for 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, in Patent Document 1, a plurality of links having front and rear insertion portions through which pins are inserted, a front insertion portion of one link, and a rear insertion portion of another link correspond to the chain width direction. A plurality of first pins and a plurality of second pins that connect the links arranged in a row so as to be bendable in the length direction, and are fixed to the front insertion portion of one link and movable to the rear insertion portion of another link The first pin that is fitted and the second pin that is movably fitted to the front insertion portion of one link and fixed to the rear insertion portion of the other link are relatively rolled and moved in contact with each other. Those that can be bent in the length direction have been proposed.
JP 2004-301257 A

  In the power transmission chain described above, the durability of the link is particularly important, and further improvement of the durability is a problem. In addition, reducing noise is an important issue.

  In terms of durability, in this type of power transmission chain, the relative movement amount between the links is preferably within a predetermined range, but when contacting the pulley (when moving from the straight portion to the circular arc portion) or separating from the pulley. At the time (when moving from the arc portion to the straight portion), the relative movement amount of the link and the pin becomes large, and there is a possibility that an indentation or a friction scar is generated on the link. Such indentations and friction marks can be a cause of lowering link durability. On the other hand, in order to reduce noise, it is preferable to use a plurality of types of links having different pitch lengths. However, when this configuration is adopted, it is necessary to avoid a decrease in durability.

  The object of the present invention is to reduce the noise by using a plurality of types of links having different pitch lengths, and to eliminate the impressions and friction marks caused by an increase in the relative movement amount between the link and the pin. An object of the present invention is to provide a power transmission chain and a power transmission device that can improve durability.

  The power transmission chain according to the present invention includes a plurality of links having front and rear insertion portions through which pins are inserted, and links arranged in the chain width direction so that a front insertion portion of one link and a rear insertion portion of another link correspond to each other. A plurality of first pins and a plurality of second pins arranged before and after connecting each other are provided, and the first pin and the second pin are relatively rolled and brought into contact with each other, whereby the links can be bent in the length direction. One of the first pin and the second pin is fixed to the front insertion part of one link and is movably fitted to the rear insertion part of the other link, and the other is In the power transmission chain that is movably fitted in the front insertion portion and fixed to the rear insertion portion of another link, the plurality of links include at least two types having different pitch lengths, and are arranged in the front and rear direction. Three The front / rear length of the link is adjusted so that the front surface of the link located in the center of the link contacts the pin in the link located on the front side, and the rear surface contacts the pin in the link located on the rear side. Thus, when the link exceeds a preset maximum bending amount, a pin abutting portion that abuts the corresponding pin and restricts the relative movement of the pin is formed. is there.

  Each link includes a front column portion for forming the front shape of the front insertion portion, a rear column portion for forming the rear shape of the rear insertion portion, and an intermediate column between the front insertion portion and the rear insertion portion. And a front upper and lower connecting part that connects the upper and lower parts of the front pillar part and the intermediate pillar part, and a rear vertical connecting part that connects the upper and lower parts of the rear pillar part and the intermediate pillar part. .

  The pitch is a distance from a contact position between the first pin and the second pin in the front insertion part to a contact position between the first pin and the second pin in the rear insertion part. For example, the shape of the front and rear insertion part remains the same between the two By changing the distance and therefore the front and rear lengths of the intermediate pillars, links with different pitches can be obtained.

  Two or more types of links having different pitches are arranged at random, thereby avoiding concentration of energy of impact force between the pin and the pulley, and noise can be greatly reduced. Arbitrary, that is, a random arrangement pattern is adopted as the order of arranging two types of links having different pitches.

  When a long link with a relatively long pitch length and a short link with a relatively short length are included, the short link located at the center of the links included in the long link on either the front or back side is the center of the short links. It is preferable that the pin abutting portion is formed by providing an extension portion on the front and rear pillar portions located on the long link side with respect to the short link located on the side.

  Conventionally, the front and rear lengths of the front and rear column portions of each link were either increased or decreased according to the increase or decrease of the pitch length, or constant regardless of the increase or decrease of the pitch length. . Therefore, when the links are arranged in the front-rear direction in the order of long, short, and long, the short link has a short front-rear length, so there is a gap between the front and rear surfaces of the short link and the corresponding pins. The front and rear surfaces of the link did not have a function as a pin contact portion. Therefore, in the case of such an arrangement, the front and rear surfaces of the short link function as pin contact portions by providing extension portions on the front and rear column portions of the short link, thereby improving durability. .

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

  When the pin is fixed to the front and rear insertion portion, the pin is fixed to the front and rear insertion portion, for example, by fitting and fixing the inner edge of the insertion portion and the outer peripheral surface of the pin by mechanical press-fitting. It may be a fit or a cold fit. 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 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 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 in any of the above.

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

  According to the power transmission chain and the power transmission device of the present invention, since the plurality of links include at least two types having different pitch lengths, noise can be reduced. In order to prevent the bending amount of the link when moving from the straight line portion to the arc portion or from the arc portion to the straight line portion from exceeding the predetermined value, the pin corresponding to the pin corresponding to the pin corresponding to the case where the predetermined maximum bending amount is exceeded. Since the pin contact portion that contacts and restricts the relative movement of the pin beyond is formed on the link, durability can be 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.

  FIGS. 1 and 2 show a part of a power transmission chain according to the present invention. The power transmission chain (1) has front and rear insertion parts (12) (13) provided at predetermined intervals 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).

  As shown in FIG. 3, in the front insertion part (12), the pin fixing part (12a) to which the pin (14) (shown by a solid line) is fixed and the interpiece (15) (shown by a two-dot chain line) are movable. The inter-piece movable part (12b) can be fitted to the rear insertion part (13), and the pin insertion part (13a) and the inter-piece (13) to which the pin (14) (indicated by a two-dot chain line) can be movably fitted. 15) It consists of an interpiece fixing part (13b) to which (shown by a solid line) is fixed. When connecting the links (11) arranged in the chain width direction, the front insertion part (12) of one link (11) and the rear insertion part (13) of the other link (11) correspond to each other. The links (11) are overlapped, and the pin (14) is fixed to the front insertion part (12) of one link (11) and movably fitted to the rear insertion part (13) of the other link (11) The interpiece (15) is movably fitted to the front insertion part (12) of one link (11) and fixed to the rear insertion part (13) 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).

  The locus of the contact position between the pin (14) and the interpiece (15) relative to the pin (14) is an involute of the circle.In this embodiment, the contact surface (14a) of the pin (14) is The cross section has an involute shape having a basic circle with a radius Rb and a center M, and the contact surface (15a) 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 part of the chain (1) to the arc part or from the arc part to the straight part, the interpiece (15) is movable in the front insertion part (12). The contact surface (15a) moves to the contact surface (14a) of the pin (14) while rolling (including some sliding contact) against the pin (14) in the fixed state in the part (12b) In the insertion part (13), the contact surface (14a) rolls against the contact surface (15a) of the interpiece (15) against the interpiece (15) with the pin (14) fixed (slightly sliding contact) The pin movable part (13a) is moved. In FIG. 3, the portions indicated by reference signs A and B are lines (points in the cross section) where the pin (14) and the interpiece (15) are in contact with each other in the straight portion of the chain (1). Is the pitch.

  The link (11) includes a front column (16) for forming the front shape of the front insertion portion (12), and a rear column (17) for forming the rear shape of the rear insertion portion (13). The front upper connection that connects the upper columnar part (18) between the front insertion part (12) and the rear insertion part (13) and the upper and lower parts of the front column part (16) and the intermediate column part (18). A rear upper connecting portion (21) and a rear lower connecting portion for connecting the upper and lower portions of the portion (19) and the front lower connecting portion (20), and the rear column portion (17) and the intermediate column portion (18). (22).

  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, one link unit includes a link row having nine links and two link rows having eight links.

  FIG. 4 includes a long link (21) having a relatively long pitch length and a short link (31) having a relatively short pitch as a plurality of links (21) and (31). ) Shows an example in which the short link (31) is located at the center. This figure shows the state that these links (21) (31) are moving along the pulleys (2) (3), and the front side (31a) of the short link (31) is the front long link ( 21) Abuts on the interpiece (15) in the front insertion part (22), and the rear surface (31b) of the short link (31) is a pin in the rear insertion part (23) of the rear long link (21). By abutting on (23), further bending of the links (21) and (31) is prevented. As a result, at the time of transition from the straight part of the chain to the arc part or from the arc part to the straight part, the link (21) is over-bent to the circumferential surface of the front and rear insertion parts (22) and (23) due to over-bending. The strong contact of the pin (14) or the interpiece (15) suppresses the generation of indentations and friction marks as starting points of cracks, thereby improving the link life.

  In FIG. 4, what is indicated by a two-dot chain line is the outline shape of the short link (11) located at the center of the short links (11). That is, the short link (31) in FIG. 4 is provided with extensions (16a) and (17a) on the front and rear pillars (16) and (17) of the short link (11) shown in FIG. When the link (21) (31) exceeds the preset maximum bending amount by the extension portions (16a) (17a), the pin (14) abuts against the corresponding pin (14) or the interpiece (15). Alternatively, pin contact portions (31a) and (31b) are formed that restrict further relative movement of the interpiece (15).

  Since links with different pitch lengths are randomly arranged, various combinations such as long / short / short and short / long / short appear in addition to the long / short / long combinations shown in the figure. 4 so that a contact relationship similar to the contact relationship between the link (31) and the pin (14) or the interpiece (15) shown in FIG. 4 is obtained (the bending angle between the links is the same as the angle shown in FIG. 4). At the same time, the link and the pin (14) or the interpiece (15) are in contact with each other), and an extension part (possibly a cut-out part) is provided at the front and rear pillars of the central link, so that the link is preset. When the maximum bending amount is exceeded, the corresponding pin (14) or interpiece (15) is abutted to form a pin abutment that restricts further relative movement of the pin (14) or interpiece (15). can do.

  This power transmission chain (1) holds the required number of pins (14) and interpieces (15) vertically on the table, and then press-fits one or several links (11) one by one. It is manufactured by going. This press-fitting is performed between the upper and lower edges of the pin (14) and the interpiece (15) and the upper and lower edges of the pin fixing part (12a) and the interpiece fixing part (13b). 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 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) roll relatively. The contact surface of the pin (14) and the interpiece (15) with reference to the pin (14) is a circular involute so that the contact surface of both the pin and the interpiece is an arc surface. Compared with the case where it is, a vibration can be made small and a noise can be reduced. And by arranging two or more types of links (11) (21) (31) with different pitches at random, the impact force between the pin (14) and the interpiece (15) and the pulley (2) (3) is reduced. Energy concentration can be avoided and noise can be greatly reduced.

  The power transmission chain described above is used in the CVT shown in FIG. 6. At this time, as shown in FIG. 5, the interpiece (15) is made shorter than the pin (14), and the interpiece (15) The end surface of the pin (14) is the conical shape of the pulley (2) with the end surface not contacting the conical sheave surfaces (2c) and (2d) of the fixed sheave (2a) and the movable sheave (2b) of the pulley (2). The sheave surfaces (2c) and (2d) are brought into contact with each other, and power is transmitted by the frictional force generated by the contact. As described above, since the pin (14) and the interpiece (15) are in rolling contact, the pin (14) hardly rotates relative to the sheave surfaces (2c) (2d) of the pulley (2). Thus, friction loss is reduced and a high power transmission rate is secured.

FIG. 1 is a plan view showing a part of one embodiment of a power transmission chain according to the present invention. FIG. 2 is an enlarged perspective view of the same. FIG. 3 is an enlarged side view of the link. FIG. 4 is an enlarged side view showing a characteristic portion. FIG. 5 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 6 is a perspective view showing a continuously variable transmission.

Explanation of symbols

(1) Power transmission chain
(2) (3) Pulley
(2a) (3b) Fixed sheave
(2b) (3a) Movable sheave
(2c) (2d) Conical sheave surface
(11) Link
(12) Front insertion part
(13) Rear insertion part
(14) Pin (1st pin)
(15) Interpiece (2nd pin)
(16) (17) Front and rear pillars
(16a) (17a) Extension
(21) Long link
(31) Short link
(31a) (31b) Pin contact part

Claims (3)

A plurality of links having front and rear insertion portions through which pins are inserted, and a plurality of links arranged before and after connecting links aligned in the chain width direction so that a front insertion portion of one link and a rear insertion portion of another link correspond to each other. The first pin and the plurality of second pins are provided, and the first pin and the second pin are relatively in rolling contact with each other, whereby the links can be bent in the longitudinal direction. One of the two pins is fixed to the front insertion part of one link and is movably fitted to the rear insertion part of the other link, and the other is movably fitted to the front insertion part of one link. In the power transmission chain that is inserted and fixed to the rear insertion part of another link,
The plurality of links include at least two types having different pitch lengths, the link located in the center among the three links arranged in the front and rear, the front of the pin in the link located on the front side, and the rear side By adjusting the longitudinal length of the link so that the rear surface abuts on the pin in the link that is positioned, if the link exceeds the preset maximum bending amount, the link abuts on the corresponding pin. A power transmission chain, characterized in that a pin abutting portion for restricting further relative movement is formed.   A long link having a relatively long pitch length and a short link having a relatively short length are included, and a short link located at the center of links included in either of the front and rear links is located at the center of the short links. 2. The power transmission chain according to claim 1, wherein a pin abutting portion is formed by providing an extension portion at the front and rear pillar portions positioned on the long link side with respect to the short link.   A power transmission chain comprising: a first pulley having a conical surface sheave surface; a second pulley having a conical surface sheave surface; and a power transmission chain spanned between the first and second pulleys. The power transmission device according to claim 1 or 2.

Images