JP4821258B2 - 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. 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 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.
JP 2005-233275 A

  In this type of power transmission chain, the durability of the link is particularly important. In the link, there are a part fixed to the pin and a part where the pin can move, but in the evaluation of the fatigue durability of the link, it is limited to the part where the pin can be moved The part fixed to the pin is also important.

  An object of the present invention is to provide a power transmission chain and a power transmission device in which the durability of a portion fixed to a pin of a link is increased, thereby improving the life of the chain.

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 part and fixed to the rear insertion part of another link, either one of the front and rear insertion parts of the link is fixed to the first pin. And second pin A second pin movable part that is movably fitted, and the other of the front and rear insertion parts of the link is a first pin movable part to which the first pin is movably fitted and a second pin fixed to which the second pin is fixed. The lubricant retaining recess is formed in at least one of the inner surface of the first pin fixing portion and the inner surface of the second pin fixing portion in the front and rear insertion portion of the link .

  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").

  In this type of power transmission chain, when a fatigue endurance test is performed, the portion fixed to the link pin may fatigue relatively quickly. Since this part is fixed (for example, press-fitted), it is considered that the lubrication state is deteriorated, and the lubrication state is improved by forming a concave portion for retaining the lubricant on the inner surface of this part. The fatigue of the portion fixed to the link pin is suppressed.

  Lubricating oil is normally supplied to the power transmission chain, and the lubricating oil is stored in the lubricant retaining recess, so that the link is reliably lubricated. The groove may be open to the outside and may be sealed. In a sealed state, grease may be held in the groove.

  The force received by the link varies depending on the position of the link. In a chain in which at least one of the first pin and the second pin is in contact with the pulley and transmits power by frictional force, the outer link (especially the outermost link and the outer link) The inner link) is disadvantageous in terms of fatigue life because the pin is deformed with respect to its axial direction (in the chain direction) due to the frictional force, and the inner surface of the insertion part is easily pulled and is subject to a large force. It has become. Therefore, a lubricant retaining recess may be provided only for one or two links on the outside. That is, the “predetermined link” may be all links, only the outermost link in the width direction, may be the outermost link in the width direction and the link inside thereof, An appropriate link may be used.

  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.

  One or a plurality of lubricant retaining recesses are provided at predetermined intervals. The recess for retaining the lubricant may be a groove extending the inner surface of the insertion portion in the length direction of the link, and the recess for retaining the lubricant is a groove extending the inner surface of the insertion portion in the thickness direction of the link. It may be said that.

  In the case where the lubricant holding recess is formed as a groove extending in the length direction of the link, the lubricant holding recess is not opened to the outside, and therefore grease can be applied in the groove. The size of the recess for retaining the lubricant is about 0.2 to 0.3 mm in depth and about 5 to 25% of the width of the link (about 0.8 to 1.0 mm). The link may be formed by pressing, and the recess for retaining the lubricant may be processed later. However, the molding condition is set so that this fractured surface becomes a groove shape by utilizing the fact that a secondary fractured surface is generated during press molding. The concave portion for retaining the lubricant can also be formed by adjusting (stroke speed, mold clearance, etc.).

  In the case where the recess for retaining the lubricant is formed as a groove extending in the thickness direction of the link, the recess for retaining the lubricant is opened to the outside, so that the lubricating oil of the chain can easily flow from the opening. Used as As the recesses for retaining the lubricant, about 2 to 4 recesses having a depth of about 0.2 to 0.3 mm and a width of about 0.2 to 0.3 mm are provided for each insertion portion. The link is formed by press working, and the lubricant retaining recess can be formed by providing a convex portion to be a lubricant retaining recess in the mold.

  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. This fitting and fixing is preferably press-fitting and is performed at the edges (upper and lower edges) of the portion orthogonal to the length direction of the insertion portion. The cross-sectional shape of the upper and lower edge portions of the pin is a convex arc shape, and correspondingly, a concave arc shape portion into which the upper and lower edge portions of the pin are press-fitted is formed in each insertion portion of the link.

  One of the front and rear insertion portions of the link is composed of a pin fixing portion to which the pin (first pin) is fixed and an interpiece movable portion to which the interpiece (second pin) is movably fitted. The other is composed of a pin movable part to which the pin is movably fitted and an interpiece fixing part to which the interpiece is fixed. The concave portion for retaining the lubricant is provided in both or one of the pin fixing portion and the interpiece fixing portion. When either one is used, it is provided on the side where fatigue is likely to occur. The lubricant holding recess may be provided in the pin movable part and the interpiece movable part. In this case, not only the fixed part but also the movable part can be lubricated.

  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, a circle involute.

  The first pin and the second pin may have different cross-sectional shapes or the same shape. Moreover, as for a link, the front-and-rear insertion part may be an independent through-hole (link with a pillar), respectively, and the front-rear insertion part may be a single through-hole (link without a pillar).

  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 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, the lubricant retaining recess is formed on the inner surface of the portion where the pin is fixed among the insertion portions of the predetermined link. The lubrication state of the fixed part is improved, the progress of fatigue in this part can be suppressed, and the fretting wear on the fitting surface can also be suppressed, so that the chain life is 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 (a), the front insertion part (12) includes a pin fixing part (12a) to which a pin (14) (shown by a solid line) is fixed and an interpiece (15) (shown by a two-dot chain line). Comprises an interpiece movable part (12b) that is movably fitted, and a rear insertion part (13) includes a pin movable part (13a) to which a pin (14) (indicated by a two-dot chain line) is movably fitted. It consists of an interpiece fixing part (13b) to which an interpiece (15) (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) 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, it has an involute shape having a basic circle with a radius Rb and a center M in the cross section, and the rolling 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 rolling contact surface (15a) moves to the rolling contact surface (14a) of the pin (14) while being in rolling contact (including some sliding contact) with respect to the pin (14) in the fixed state in the part (12b). In the rear insertion portion (13), the rolling contact surface (14a) is in rolling contact with the rolling contact surface (15a) of the interpiece (15) with respect to the interpiece (15) in which the pin (14) is fixed ( It moves in the pin movable part (13a) while including a slight sliding contact. In addition, in Fig.3 (a), the location shown with the code | symbol A and B is the line (point in a cross section) which the pin (14) and the interpiece (15) are contacting in the linear part of a chain (1). , AB is the pitch.

  As can be seen from FIG. 3 (b), which is a bb cross section of FIG. 3 (a), and FIG. 3 (c), which is a cc cross section, among the insertion portions (12) and (13) of the link (11). In the length direction of the link (11) on the inner surface of the upper and lower edge portions of the pin (14) or the interpiece (15), that is, the pin fixing portion (12a) and the interpiece fixing portion (13b) A extending lubricant holding groove (lubricant holding recess) (16) is formed. Therefore, the lubricating oil supplied to the power transmission chain (1) is stored in the lubricant retaining groove (16), whereby the pin fixing portion (12a) and the interpiece fixing portion (13b) are smoothly lubricated. Further, by holding the grease in the lubricant holding groove (16), it is possible to always hold an appropriate amount of lubricant on the link in a position where the lubricant is difficult to be supplied. The lubricant retaining groove (16) may be extended to the upper and lower edges of the interpiece movable part (12b) and the upper and lower edges of the pin movable part (13a) .In this case, the interpiece movable part ( The movement of the interpiece (15) in 12b) and the movement of the pin (14) in the pin movable part (13a) are made smoother by the lubricant in the lubricant holding groove (16).

  FIG. 4 shows another embodiment of the lubricant holding groove. In the following description, the same components as those in FIG.

  As can be seen from FIG. 4 (a) and FIG. 4 (b) which is a bb cross section thereof, the pin (14) or the interpiece (15) of the insertion portions (12) and (13) of the link (11) is provided. Four lubricant retaining grooves (lubricated) extending in the thickness direction of the link (11) are formed on the fixed portions, that is, the inner surfaces of the upper and lower edges of the pin fixing portion (12a) and the interpiece fixing portion (13b). An agent holding recess (18) is formed. Therefore, the lubricating oil supplied to the power transmission chain (1) is stored in these lubricant retaining grooves (18), so that the pin fixing portion (12a) and the interpiece fixing portion (13b) are smoothly lubricated. Is called. The number of lubricant retaining grooves (18) may be a plurality other than four or one. Moreover, although the groove | channel (18) showed the example opened to a link side surface, it may become a recessed part without opening. In this case, the retention of the lubricating oil is good.

  In the above embodiment, the front insertion part (12) and the rear insertion part (13) are each an independent through hole, but the through hole for obtaining these insertion parts (12) (13) is, Although not shown in the drawings, in order to alleviate the stress concentration at the hole edge, the front and rear insertion portions (12) and (13) may be communicated with each other by a communication portion so as to form a single long through hole in the front and rear.

  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.

  This power transmission chain (1) is used in the V-type pulley type CVT shown in FIG. 5. At this time, for example, the interpiece (second pin) (15) is replaced with the pin (first pin) (14). Pin (14) with the end face of the interpiece (15) not contacting the fixed sheave (2a) of the pulley (2) and the conical sheave surfaces (2c) (2d) of the movable sheave (2b). ) Comes into contact with the conical sheave surfaces (2c) and (2d) of the pulley (2), 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 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.

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 first embodiment of the link. FIG. 4 is an enlarged side view of the second embodiment of the link. 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 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) (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) Lubricant holding groove in the length direction (concave for holding lubricant)
(18) Lubricant holding groove in the thickness direction (lubricant holding recess)

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, 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 the other link,
Either one of the front and rear insertion portions of the link includes a first pin fixing portion to which the first pin is fixed and a second pin movable portion to which the second pin is movably fitted, and the other of the link front and rear insertion portions is The first pin movable part to which the first pin is movably fitted and the second pin fixing part to which the second pin is fixed, and the inner surface of the first pin fixing part and the second pin fixing in the front and rear insertion part of the link A power transmission chain, wherein a recess for retaining a lubricant is formed on at least one of the inner surface of the part .   2. The power transmission chain according to claim 1, wherein a lubricant retaining recess is not formed on an inner surface of the first pin movable portion and an inner surface of the second pin movable portion in the front and rear insertion portion of the link. Lubricant holding recess, the power transmission chain of claim 1 or 2 which is a groove extending in the longitudinal direction of the link. Lubricant holding recess is claim 1 or 2 of the power transmission chain is characterized in that there is a groove extending in the thickness direction of the link. A power transmission chain comprising: a first pulley having a conical sheave surface; a second pulley having a conical sheave surface; and a power transmission chain spanning the first and second pulleys. A power transmission device according to any one of claims 1 to 4 .

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