JP4839716B2 - 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 suitable for a continuously variable transmission (CVT) of an automobile and a power transmission device using the same.

  As a continuously variable transmission for an automobile, as shown in FIG. 7, 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 in a longitudinal direction so as to be 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.
Japanese Patent Laid-Open No. 8-31725

  In the power transmission chain disclosed in Patent Document 1, for example, the pin and the link are fixed by press-fitting. For example, when the parts are made small and thin in order to meet the demands for downsizing and weight reduction of the chain, When the stress increases, the durability of the link may decrease. Also, when the transmission ratio changes, a relatively large axial misalignment may occur, which may cause a large force to act on the link, which may be disadvantageous in terms of durability. .

  An object of the present invention is to provide a power transmission chain and a power transmission device that can prevent an excessive load from acting on a link due to a force caused by misalignment that occurs when a gear ratio changes.

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 that connect each other in the length direction, and the first pin and the second pin are fitted in the front and rear insertion portions of each link, respectively, and these pins are relatively In the power transmission chain in which the links can be bent in the longitudinal direction by rolling contact movement, the plurality of links are either one of the first pin and the second pin in the front and rear insertion portions. Are press-fitted and fixed, and a press-fit link in which one of the first pin and the second pin is press-fitted and fixed to either one of the front and rear insertion portions, and a first pin and a second pin are inserted to the front and rear insertion portions. Ri Do and a rotatably to fit non-press-fitting the link to be placed, with a link which is located outermost, including adjacent rows back and forth are pressed link, the remaining columns in the press-fitting links on the outermost side All of the links are non-press-fit links, and for columns having no press-fit links on the outermost side, one or two of the centers are press-fit links, and the rest are non-press-fit links. It is what.

  For the press-fit link, the front insertion part of the link includes a first pin fixing part to which the first pin is fixed and a second pin movable part to which the second pin is movably fitted, and the rear insertion part of the link is The first pin movable part into which the first pin is movably fitted and the second pin fixing part to which the second pin is fixed are included. The front / rear insertion part is formed with a front / rear through hole separated from each other in the link, and the front through hole = front insertion part and the rear through hole = rear insertion part may be formed. The front part of the hole = the front insertion part and the rear part of the through hole = the rear insertion part.

  The press-fitting is preferably performed between the upper and lower edges of the pin (the direction in which the chain travels forward and backward, the width direction of the chain is the right and left, and the direction perpendicular to both) and the upper and lower edges of the insertion part. The margin is 0.005 mm to 0.1 mm, and the non-press-fit link has the same shape as the press-fit link except for the portion corresponding to the press-fit allowance, and the gap between the pin and the insertion portion peripheral edge in the non-press-fit link is 0.005 to 0.2 mm.

  There are basically two press-fitting links in one row, and the rest are non-press-fit links. Usually, the number of links included in one column is about 5 to 10, and the number of press-fit links <the number of non-press-fit links. The arrangement of the press-fit link is determined so that the link does not fall off from the pin and the pin does not fall off from the entire chain.

  The chain is formed, for example, by linking three link rows formed of a plurality of links having the same phase in the width direction in the traveling direction to form one link unit and connecting the plurality of link units in the traveling direction. In this case, if the link unit is composed of a link row of 9 links, a link row of 8 links, and a link row of 9 links, the link outside the link row of 9 links becomes the outermost link. This is always a press-fit link. As for the links outside the row of 8 links, the outermost link of the row of 9 links prevents the dropout, so these do not have to be press-fit links. However, if all the links in the row of these eight links are used for non-press-fit, the pins fitted in these links become completely free, so at least one, preferably two links are press-fit. It is considered as a link. As for the position where the press-fitting link is arranged in the row having no press-fitting link on the outermost side, two of the outer links in the row may be the press-fitting links, and two at the center are the press-fitting links. In short, the press-fitting link may be arranged anywhere. In this way, a plurality of link rows composed of a plurality of links having the same phase in the width direction are arranged in the traveling direction (for example, three) to form one link unit, and a plurality of link units are connected in the traveling direction to form a chain. When formed, it is easy to decide which link should be used as the press-fit link and to manufacture easily.

  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 referred to as “pin”), and the other is a pulley. The pin which is not in contact with the pin (referred to as an interpiece or strip, hereinafter referred to as “interpiece”) may be used.

  For example, the first pin and the second pin are formed in a required curved surface so that either one of the contact surfaces is a flat surface and the other contact surface can be relatively rolled and moved. Moreover, you may make it each contact surface form a required curved surface for the 1st pin and the 2nd pin. In any case, the contact surface shape of each pin is formed in two types (for example, one having a relatively large curvature and one having a relatively small curvature), so that the pins having different trajectories of rolling contact movement are formed. There may be two types of sets. The locus of the contact position between the first pin and the second pin is, for example, a circle involute.

  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.

  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. Appropriate steel such as bearing steel is used as the material of the pin.

  This power transmission chain is manufactured, for example, by holding a required number of pins and interpieces vertically on a table, and then fitting links one by one or several together. At this time, the press-fitting link needs to be managed with respect to the press-fitting allowance, but the non-press-fitting link is not required to be managed, and the manufacturing becomes easy and the quality is improved. In addition, since the links to be press-fitted are limited, the possibility of occurrence of burrs during manufacturing can be reduced, and for those in which the press-fitting links are arranged outside, it is easy to check the burrs. Become.

  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 of an automobile.

  According to the power transmission chain and the power transmission device of the present invention, since both the press-fit link and the non-press-fit link are used, the press-fit link prevents the drop-off and the drop-off of the chain. With respect to the force caused by misalignment in the axial direction that occurs when the gear ratio changes, the non-press-fit link releases this force, thereby preventing an excessive load from acting on the link. Therefore, the durability of the link can be improved while maintaining the function to be ensured by press-fitting.

  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. ) (22) (23) having a plurality of links (11) (21) and a plurality of pins (first pins) for connecting the links (11) (21) arranged in the chain width direction so that they can be bent in the length direction ) (14) and an interpiece (second pin) (15).

  For the links (11) and (21), two types of links (11) for press-fitting and links for non-press-fitting (21) are used. These links for press-fitting (11) and links for press-fitting (21 ) Are mixed based on a predetermined mixed pattern.

  As shown in FIG. 3, the front insertion portion (12) of the press-fit link (11) includes a pin fixing portion (12a) and a second pin to which a pin (14) (shown by a solid line) as a first pin is fixed. Interpiece (15) (shown with a two-dot chain line) consists of an interpiece movable part (12b) that is movably fitted, and the rear insertion part (13) is a pin (14) (shown with a two-dot chain line) Are composed of a pin movable part (13a) to which the two are movably fitted and an interpiece fixing part (13b) to which the interpiece (15) (shown by a solid line) is fixed.

  As shown in FIG. 4, the front insertion portion (22) of the non-press-fit link (21) includes a pin movable portion (22a) to which a pin (14) (shown by a solid line) is movably fitted and an interpiece (15 ) (Shown by the two-dot chain line) consists of a movable interpiece movable part (22b), and the rear insertion part (23) is fitted so that the pin (14) (shown by the two-dot chain line) can be moved The movable pin part (23a) and the interpiece (15) (shown by a solid line) are movably fitted to each other and the movable interpiece part (23b).

  The difference between the press-fit link (11) and the non-press-fit link (21) is that the press-fit link (11) is vertically moved (P1) (P2) of the pin fixing portion (12a) as shown in FIG. And in the upper and lower parts (P3) and (P4) of the interpiece fixing part (13b), there is a press-fitting allowance for the pin (14) or the interpiece (15), whereas for the non-press-fit link (21) The pin fixing part (12a) of the press-fit link (11) is replaced with the pin movable part (22a), and the inter-piece fixed part (13b) of the press-fit link (11) is replaced with the inter-piece movable part (23b). Therefore, there is no press-fitting allowance (there is a gap) at any position.

  In this power transmission chain (1), the necessary number of pins (14) and interpieces (15) are held vertically on a table, and then one or several links (11) and (21) are collected. Manufactured by fitting. For the press-fit link (11), the upper and lower edges of the pin (14) and the interpiece (15) and the upper and lower edges of the pin fixing portion (12a) (22a) and the interpiece fixing portion (13b) (23b) The press-fitting allowance is 0.005 mm to 0.1 mm.

  When connecting the links (11) (21) arranged in the chain width direction, the front insertion part (12) (22) of one link (11) (21) and the rear insertion of the other link (11) (21) The links (11) and (21) are overlapped so that the sections (13) and (23) correspond to each other. At this time, for the press-fitting link (11), the pin (14) is fixed to the front insertion part (12) of the press-fitting link (11), and the interpiece (15) is the rear insertion part of the press-fitting link (11). Fixed to (13). This prevents the links (11) and (21) from falling off and the pins (14) and the interpiece (15) from falling off. As for the non-press-fit link (21), the pin (14) and the interpiece (15) are movably fitted into the corresponding front and rear insertion portions (22) and (23). As a result, the pin (14) and the interpiece (15) are relatively rolled and brought into contact with each other, and the links (11) and (21) 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). Thus, when each link (11) (21) moves from the straight part of the chain (1) to the arc part or from the arc part to the straight part, the front insertion part (12) (22) 15) in the interpiece movable part (12b) (22b), the contact surface (15a) is rolling contact with the contact surface (14a) of the pin (14) with respect to the pin (14) (including some sliding contact) In the rear insertion part (13) (23), the pin (14) rolls the contact surface (14a) to the contact surface (15a) of the interpiece (15) in the interpiece (15). It moves in the pin movable part (13a) while making contact (including some sliding contact). 3 and 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 linear portion of the chain (1). , AB is the pitch.

  The non-press-fit link (21) and the press-fit link (11) have the same shape except for the press-fit allowance, so the press-fit link (11) and the non-press-fit link (21) are connected to the chain (1 ) Can be set freely.

  In the example shown in FIG. 1, the outermost link in the width direction of each row is a press-fit link (11), and the other links are non-press-fit links (21). As can be seen from FIG. 1, the outermost link (11) indicated by the reference symbol K prevents the link (11) indicated by the reference symbol L from falling off. The press-fitting link (21) can be used. However, in this case, the axial movement of the pins (14) and the interpiece (15) in this row cannot be prevented by press-fitting. In order to compensate for this, in the example shown in FIG. 5, the L link (11), which is press-fitted in FIG. 1, is changed to a non-press-fit link (21), and in FIG. Of the links in the middle portion of the row that was (21), the one in the center is the press-fit link (11). In FIG. 5, all links not denoted by reference numeral (11) are non-press-fit links. Although not shown, the press-fit link (11) is arranged so that the non-press-fit link (21) does not fall off from the pin (14) and the interpiece (15), and the pin (14) from the entire chain. Various modifications can be made as long as the interpiece (15) is prevented from falling off.

  1, FIG. 2 and FIG. 5 show only a part of the chain (1), but the chain (1) is a link row (R1) (R2) composed of a plurality of links having the same phase in the width direction. ) (R3) are arranged in a moving direction (front-rear direction) to form one link unit, and a plurality of link units (R1), (R2) and (R3) are connected in the moving direction. ing. Therefore, by determining which of the three link rows (R1), (R2), and (R3) is the press-fit link (11), the arrangement of the press-fit link (11) of the entire chain (1) is determined. can do.

  This power transmission chain (1) is used in the CVT shown in FIG. 6. At this time, the interpiece (15) is made shorter than the pin (14), and the end face of the interpiece (15) is a pulley (2 ) Of the fixed sheave (2a) of the movable sheave (2b) and the conical sheave surface (2c) of the pulley (2) with the end surface of the pin (14) not contacting the conical sheave surfaces (2c) (2d) of the movable sheave (2b). The power is transmitted by the frictional force caused by the contact with (2d). As described above, since the pin (14) and the interpiece (15) are in rolling contact movement, the pin (14) hardly rotates with respect to the sheave surfaces (2c) (2d) of the pulley (2). Thus, friction loss is reduced and a high power transmission rate is secured.

  Note that the configuration in which the press-fit link (11) and the non-press-fit link (21) are mixed includes a second pin that transmits power by contacting the sheave surface instead of the interpiece (15). The present invention can be applied to a chain including a chain (the first pin and the second pin having the same length and both contacting the sheave surface) and various other types of power transmission chains.

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 perspective view of the same. FIG. 3 is an enlarged side view of the press-fitting link. FIG. 4 is an enlarged side view of the non-press-fit link. FIG. 5 is a plan view showing a part of a second embodiment of the power transmission chain according to the present invention. FIG. 6 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 7 is a perspective view showing an example of a continuously variable transmission in which the power transmission chain according to the present invention is used.

Explanation of symbols

(1) Power transmission chain
(2) (3) Pulley
(2a) (3a) Fixed sheave
(2b) (3b) Movable sheave
(2c) (2d) Conical sheave surface
(11) Press-fit link
(12) Front insertion part
(13) Rear insertion part
(14) Pin (1st pin)
(15) Interpiece (2nd pin)
(21) Non-press-fit link
(22) Front insertion part
(23) Rear insertion part

Claims (2)

A plurality of links having front and rear insertion portions through which pins are inserted, and links arranged in the chain width direction are connected in the length 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 are provided, and the first pin and the second pin are fitted in the front and rear insertion portions of each link, respectively, and these pins are relatively rolled and contacted to move the link. In the power transmission chain that can be bent in the longitudinal direction between each other,
In the plurality of links, either one of the first pin and the second pin is press-fitted and fixed to either one of the front and rear insertion portions, and one of the first pin and the second pin is inserted to the other insertion portion of the front and rear and press-fitting the link but which is press-fitted, Ri Do and a non-press-fitting link that the first pin and the second pin is fitted movably in the insertion portion front and rear, located on the outermost side including the column sequentially adjacent The link to be pressed is a press-fit link, and the remaining links in the row having the press-fit link on the outermost side are all non-press-fit links. One or two of them are press-fit links, and the rest are non-press-fit links . 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 claim 1 .

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