JP2008144824A - Power transmission chain manufacturing method and manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission chain manufacturing method and manufacturing apparatus capable of ensuring appropriate pretensioning conditions even with a chain wound around a small-diameter pulley.
A pretension applying device is configured to wrap an endless chain between a pretension applying first rotating shaft and a pretension applying second rotating shaft to apply pretension to the chain. At the time of application, the rotating shafts are pulled while the outer peripheral surface of each rotating shaft is in contact with the surface of the link on the inner diameter side of the chain.
[Selection] Figure 4

Description

  The present invention relates to a method and apparatus for manufacturing a power transmission chain, and more particularly to a method and apparatus for manufacturing a power transmission chain 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). 2. Description of the Related Art A chain-type continuously variable transmission that generates a load and transmits torque by the frictional force of the contact portion is known.

  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.

In this type of power transmission chain, in order to improve durability, a pretensioning device having a configuration similar to a continuously variable transmission (actual machine) actually used is used in the manufacturing process, and the pin is An appropriate residual compressive stress is applied to the link by pre-applying (pre-tensioning) tension to the chain in a state of being sandwiched between conical sheave surfaces.
JP 2006-102784 A

  In this type of power transmission chain, the durability of the link is particularly important, and further improvement of the durability is a problem. Conventionally, the diameter of the pulley at the time of pre-tension was not considered, but from the viewpoint of applying pre-tension under conditions severer than the actual use conditions, the winding diameter at the time of pre-tension is a continuously variable transmission. It is preferable to include a size equal to or smaller than the minimum winding diameter obtained. However, when a pretension applying device having a configuration similar to that of the actual machine is used, there is a problem that when the pulley is small, the link bottom (the surface on the inner diameter side of the link) interferes with the pulley shaft before applying a predetermined load. is there. In order to avoid the interference, the pulley shaft may be made thin. However, if a pretension is applied so that a larger stress than that of the actual machine is applied, the pulley shaft of the pretension applying device may be broken.

  An object of the present invention is to provide a method and an apparatus for manufacturing a power transmission chain that can ensure appropriate pretensioning conditions even with a chain wound around a pulley having a small diameter.

  A method for manufacturing a power transmission chain according to the present invention is a method for manufacturing a power transmission chain comprising a plurality of links and a plurality of pins connecting them, and wound around a pair of pulleys of a continuously variable transmission. A step of applying a pretension to the chain by winding an endless chain between the first rotating shaft for applying tension and the second rotating shaft for applying pretension. A pretension is imparted by pulling the rotating shafts in a state where the inner diameter side surface is in contact.

  A power transmission chain manufacturing apparatus according to the present invention is a power transmission chain manufacturing apparatus comprising a plurality of links and a plurality of pins connecting them, and wound around a pair of pulleys of a continuously variable transmission. A pretensioning device is provided for applying pretension to the chain by winding an endless chain between the first rotating shaft for applying tension and the second rotating shaft for applying pretension. The rotating shafts are pulled with each other in a state where the outer peripheral surface of the shaft is in contact with the surface of the link on the inner diameter side of the chain.

  In the power transmission chain obtained by the manufacturing method and the manufacturing apparatus according to the present invention, the winding diameter is changed steplessly with the change in the distance between sheaves of each pulley consisting of a fixed sheave and a movable sheave each having a conical sheave surface. Therefore, it is suitable for use in a continuously variable transmission in which a continuously variable transmission is performed.

  If the pretension is applied with the pin sandwiched between conical sheave surfaces so that it corresponds to the actual machine of the continuously variable transmission, the link and the pulley shaft may come into contact if the winding diameter is large. However, if the winding diameter is reduced, the link and the pulley shaft may come into contact before applying a predetermined load. At the time of this contact, a large stress is concentrated on the contact portion between the link and the pulley shaft, which may cause damage to the link or the pulley, or a predetermined load cannot be applied and durability may not be improved. On the other hand, when pulling the rotating shafts in a state where the outer peripheral surface of each rotating shaft for pretensioning and the surface on the inner diameter side of the link are in contact, the link and the pulley shaft are always in contact with each other. Therefore, no stress is concentrated on the contact portion between the link and the pretensioning rotating shaft. Therefore, even if the diameter of the rotating shaft is reduced, the link or the shaft is not damaged. Pretension can be reliably applied.

  It is preferable that at least one of the pretension applying rotary shafts has a size equal to or smaller than the minimum winding diameter obtained by the continuously variable transmission. In continuously variable transmissions, underdrive (hereinafter referred to as “U / D”) has the maximum speed ratio for low-speed driving, and overdrive (hereinafter referred to as “U / D”) for low-speed driving. O / D "))). The movement of the pin and thus the load on the link is greater when rotating along a pulley with a smaller winding diameter than when rotating along a pulley with a larger winding diameter. Therefore, by setting the winding diameter at the time of applying the pretension (the outer diameter of the pretensioning rotating shaft) to be equal to or less than the minimum winding diameter obtained by the continuously variable transmission, a uniform stress is applied to the link over a wide range. And the link can be stretched evenly.

  When the pretension applying device is a model of a continuously variable transmission (actual machine), the winding diameter can be changed steplessly, and pretension can be applied under conditions close to the conditions of use of the actual machine. Therefore, there is a problem that the configuration of the pretension applying device is complicated and expensive. The above-described pretension applying device is simple in configuration and can reduce costs, and when applying pretension with a small winding diameter, which is a severe (important) condition for the chain, the pulley shaft and the link Can be solved.

  The pretension is set such that the maximum principal stress generated in the link is equal to or greater than the elastic limit stress of the link. By doing so, the link is plastically deformed by the pretension, an appropriate residual compressive stress is applied to the inside of the link, and the fatigue durability performance is improved.

  The above manufacturing method is suitable for manufacturing various types of power transmission chains for continuously variable transmissions, but includes a plurality of links having front and rear insertion portions through which pins are inserted, a front insertion portion of one link, and the like. A plurality of first pins and a plurality of second pins arranged before and after connecting the links arranged in the chain width direction so as to correspond to the rear insertion portions of the links, and the first pins and the second pins roll relatively. By making contact movement, the links can be bent in the longitudinal direction, and one of the first pin and the second pin is fixed to the front insertion portion of one link and after the other link. A power transmission chain is manufactured that is movably fitted in the insertion part, and the other is movably fitted in the front insertion part of one link and fixed to the rear insertion part of the other link. More suitable for.

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

  The link is made of, for example, spring steel or carbon tool steel. The material of the link is not limited to spring steel or carbon tool steel, but 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 this fitting and fixing, the pre-tension is applied as described above, so that an appropriate residual compressive stress is uniformly and accurately applied to the pin fixing portion (pin press-fitting portion) of the link.

  According to the power transmission chain manufacturing method and manufacturing apparatus of the present invention, by applying a pretension by pulling with a simple shaft, the device can be made simple and inexpensive, and the shaft diameter can be reduced. Since shaft breakage due to stress concentration is prevented, appropriate pretensioning conditions can be ensured even with a chain wound around a small-diameter pulley.

  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 part of a power transmission chain manufactured by a method and apparatus for manufacturing a power transmission chain according to the present invention. The power transmission chain (1) is provided at predetermined intervals in the chain length direction. A plurality of links (11) having the inserted front and rear insertion portions (12) and (13) and a plurality of pins (first pins) for connecting the links (11) arranged in the chain width direction so as to be bent in the length direction ( 14) and an interpiece (second pin) (15). The interpiece (15) is made shorter than the pin (14), and both are opposed to each other with the interpiece (15) disposed on the front side and the pin (14) disposed on the rear side.

  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.

  As shown in FIG. 2, the front insertion part (12) of the link (11) has a pin movable part (16) to which the pin (14) is movably fitted and an interpiece fixing to which the interpiece (15) is fixed. The rear insertion part (13) consists of a pin fixing part (18) to which the pin (14) is fixed and an interpiece movable part (19) to which the interpiece (15) is movably fitted. Become.

  Each pin (14) is wider in the front-rear direction than the interpiece (15), and the upper and lower edges of the interpiece (15) have protruding edges (15a) extending to the respective pins (14) side. ) (15b).

  In FIG. 2, the portions indicated by reference signs A and B are lines (points in the cross section) where the pin (14) and the interpiece (15) are in contact with each other in the straight portion of the chain (1), and the distance between AB. Is the pitch.

  When connecting the links (11) aligned in the chain width direction, the links (11) so that the front insertion part (12) of one link (11) and the rear insertion part (13) of the other link (11) correspond to each other ( 11) are overlapped with each other, the pin (14) is fixed to the rear insertion part (13) of one link (11) and movably fitted to the front insertion part (12) of the other link (11), The interpiece (15) is movably fitted to the rear insertion portion (13) of one link (11) and fixed to the front insertion portion (12) of the other link (11). The pins (14) and the interpiece (15) are relatively rolled and brought into contact with each other, whereby the links (11) can be bent in the length direction (front-rear direction).

  At the boundary between the pin fixing part (18) of the link (11) and the interpiece movable part (19), the upper and lower concave arcuate guide parts (19a) (19b) of the interpiece movable part (19) are connected. Upper and lower convex arc-shaped holding portions (18a) and (18b) for holding the pin (14) fixed to the pin fixing portion (18) are provided. Similarly, at the boundary between the interpiece fixing part (17) and the pin movable part (16), the upper and lower concave arcuate guide parts (16a) and (16b) of the pin movable part (16) are connected to the interpiece fixed part. Upper and lower convex arc-shaped holding portions (17a) and (17b) for holding the interpiece (15) fixed to the portion (17) are provided.

  The locus of the contact position between the pin (14) and the interpiece (15) with respect to the pin (14) is an involute of the circle.In this embodiment, the contact surface of the pin (14) It has an involute shape having a base circle of radius Rb and center M, and the contact surface 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 contact surface of the piece (15) moves in the pin movable part (16) while rolling (including some sliding contact) to the contact surface of the interpiece (15), and in the rear insertion part (13) The interpiece (15) rolls into contact with the contact surface of the pin (14) with respect to the pin (14) fixed in the interpiece movable part (19) (including some sliding contact). Move while.

  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.

  This power transmission chain (1) is used in the V-type pulley type CVT shown in FIG. 3. 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 ensured.

  In FIG. 3, when the movable sheave (2b) of the drive pulley (2) at the position indicated by the solid line is moved toward and away from the fixed sheave (2a), the winding diameter of the chain (1) is as shown in FIG. As indicated by the chain line, it is large when approaching and small when separated. In the driven pulley (3), although not shown in the drawing, when the movable sheave moves in the opposite direction to the movable sheave (2b) of the drive pulley (2) and the winding diameter of the drive pulley (2) increases, the driven pulley When the winding diameter of (3) decreases and the winding diameter of the drive pulley (2) decreases, the winding diameter of the driven pulley (3) increases. As a result, on the basis of the state where the gear ratio is 1: 1 (initial value), the winding diameter of the drive pulley (2) is minimum and the winding diameter of the driven pulley (3) is maximum U / D. A state is obtained, and an O / D state in which the winding diameter of the drive pulley (2) is maximum and the winding diameter of the driven pulley (3) is minimum is obtained.

  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. Thus, a pretension is applied to the assembled chain (1).

  4 and 5 show a pretensioning device used in the method and apparatus for manufacturing a power transmission chain according to the present invention.

  The pretension applying device (31) approaches and separates from the pretension applying first rotating shaft (32) driven by a rotation driving device (not shown) and the pretension applying first rotating shaft (32). And a second pre-tension applying second rotating shaft (33).

  In an actual continuously variable transmission, the chain (1) is held by pinching the pin (14) between the fixed sheave (2a) and the movable sheave (2b) as shown in FIG. 2e) is used in a state where the outer peripheral surface of the link (11) is not in contact with the inner surface of the chain (11), whereas in this pretensioning device (31), the outer periphery of each rotating shaft (32) (33) The chain (1) is held by bringing the surface into contact with the surface of the link (11) on the inner diameter side of the chain, and in this state, the rotating shafts (32) and (33) are pulled together to apply pretension. Yes.

  The outer diameters of the rotary shafts (32) and (33) are set to the minimum winding diameter obtained by the continuously variable transmission. This diameter is the same as the smaller diameter of the U / D state or the O / D state, and the movement of the pin (14) and the interpiece (15) is large, which is a severe condition for the chain (1). In addition, the magnitude of the tension is such that the maximum principal stress value generated inside the link (11) (especially the press-fitting part at the pin fixing part (12a) and the interpiece fixing part (13b)) is greater than the elastic limit of the link (11). And it sets so that it may become below a plastic limit, and, thereby, an appropriate residual compressive stress is given inside a link (11).

  According to this pretensioning device (31), the outer peripheral surface of each rotating shaft (32) (33) and the surface of the link (11) on the inner diameter side of the chain are always in contact with each other. Stress concentration that occurs when a link (11) and pulley shaft (2e) interfere with each other is avoided, and a small-sized chain (1) is used to pre-tension with a small-diameter rotating shaft (32) (33). Even in the case of application, damage to the rotating shafts (32), (33) and the link (11) can be prevented.

  The pre-tensioning can be applied to a chain in which the lengths of the first pin and the second pin are substantially equal, both of which are in contact with the sheave surface. The present invention can also be applied to a chain in which both are movably fitted to the front and rear insertion portions.

FIG. 1 is a plan view showing a part of an embodiment of a power transmission chain manufactured by a power transmission chain manufacturing method and a manufacturing apparatus according to the present invention. FIG. 2 is an enlarged side view of the link. FIG. 3 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 4 is a side view schematically showing the pretension applying device. FIG. 5 is a front view of the same. FIG. 6 is a perspective view showing a continuously variable transmission.

Explanation of symbols

(1) Power transmission chain
(2) (3) Pulley
(11) Link
(14) Pin (1st pin)
(15) Interpiece (2nd pin)
(31) Pretensioning device
(32) First rotary shaft for pretensioning
(33) Second rotary shaft for pretensioning

Claims (2)

A method of manufacturing a power transmission chain comprising a plurality of links and a plurality of pins connecting them, and being wound between a pair of pulleys of a continuously variable transmission,
A step of applying a pretension to the chain by winding an endless chain between the first rotating shaft for applying pretension and the second rotating shaft for applying pretension. A method of manufacturing a power transmission chain, wherein a pretension is applied by pulling the rotating shafts in a state where the surface on the inner diameter side of the chain is in contact. An apparatus for manufacturing a power transmission chain comprising a plurality of links and a plurality of pins connecting them, and wound between a pair of pulleys of a continuously variable transmission,
A pretensioning device is provided for applying a pretension to the chain by winding an endless chain between the first rotating shaft for pretensioning and the second rotating shaft for pretensioning. An apparatus for manufacturing a power transmission chain, wherein the rotating shafts are pulled with the outer peripheral surface of the rotating shaft in contact with the surface on the inner diameter side of the link.

Images