JP4770598B2 - Power transmission chain and power transmission device - Google Patents

Description

  The present invention relates to a power transmission chain, and more particularly to a power transmission chain and a power transmission device suitable for a continuously variable transmission (CVT) of a vehicle such as an automobile.

  As a continuously variable transmission for an automobile, as shown in FIG. 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 of Patent Document 1, each pin is within a preset bending range while being in rolling contact with each other as the chain moves from a straight portion to a curved portion or from a curved portion to a straight portion. The reciprocating motion is repeated, and accordingly, the links bend each other. When this power transmission chain is used in a continuously variable transmission, it may exceed the preset bending range (overbend) due to changes in input torque or shifts. This overbend may cause link deformation or increased noise. Cause.

  An object of the present invention is to provide a power transmission chain and a power transmission device that can prevent relative movement between pins exceeding a preset bending angle, thereby suppressing the deformation of a link and the generation of noise. .

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. A predetermined bending angle range of the second pin with respect to the first pin when the power transmission chain transitions from the straight portion to the curved portion is defined. the convex portion provided on one of which is fitted in a recess provided in the other, the bending angle of the second pin to the first pin is maximum in the range of the predetermined bending angle Those characterized that you prevented from exceeding a song angle.

  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 edge of the pin (the outer diameter side edge of the chain and the inner diameter side edge of the chain) is the guided surface, and the edge of the front and rear insertion part of the link (the outer diameter side edge of the chain and the inner diameter side of the chain) Guided by a guide formed on the inner periphery. When transitioning from a straight part of a chain to a curved part or from a curved part to a straight part, one pin moves while making rolling contact with the other pin, and the contact position between the pins moves to move the bending angle between the pins. Changes, and accordingly, the bending angle between adjacent links also changes. Contact between the pins is line contact along the longitudinal direction of the pins (point contact in the cross section of the pin). The range of the guide portion is determined in consideration of the bending range of the link when moving from the straight portion of the chain to the curved portion or from the curved portion to the straight portion. In chains for continuously variable transmissions, etc., the torque acting on the chain changes or the chain speed changes, so that the inertial force etc. fluctuates, and the link or pin angle is set in advance. There is a possibility of overbending beyond the limit. Furthermore, the pins may be displaced in the direction along the rolling contact surface. However, when the convex portion of the other pin fits into the concave portion of one pin, it is excessively bent or in the direction along the rolling contact surface. Misalignment is prevented. Thereby, the deformation | transformation of a link and generation | occurrence | production of noise are suppressed.

  The bending angle of the second pin with respect to the first pin when the link is in the curved part of the chain is, for example, the tangent at the contact position of both pins when the link is in the linear part of the chain, and the link is The tangent line at the contact position of both pins in the case of the curved portion is the angle formed by this reference line. In addition, the bending angle of adjacent links is, for example, a line connecting a contact position between pins in the front insertion part of one link and a contact position of pins in the rear insertion part, and in the front insertion part of the other link. The angle formed by the line connecting the contact position between the pins in the rear and the contact position between the pins in the rear insertion portion.

  When setting the bending angle between the pins, it is considered that a movement exceeding the maximum bending angle can be prevented by providing a convex portion on one pin and bringing it into contact with the corresponding surface of the other pin. However, in this case, since the contact between the two pins is a line contact at two locations, the movement of the other pin with respect to one pin is not a movement caused by rolling, but along the rolling contact surface between the pins. And the pin is in excessive contact with the link. This excessive contact causes deformation of the link and an increase in noise, but is prevented by fitting the convex portion into the concave portion. The fitting between the convex portion and the concave portion may be surface contact (fitting between the circular arc-shaped concave portion and the convex portion of the circular arc section), or line contact at two locations (the cross-section V-shaped concave portion and the cross-section arc-shaped convex portion). Or surface contact between the surfaces located on the outer diameter side of the chain (the surface located on the inner diameter side of the chain by fitting the half surface of the arc-shaped concave section with the half surface of the arc-shaped convex section) There may be a gap between them, and line contact at one place between the surfaces located on the outer diameter side of the chain (by fitting the half surface of the V-shaped concave section and the half surface of the arc-shaped convex section into the chain, A gap may exist between the surfaces positioned on the inner diameter side). In short, the shape of the concave and convex portions prevents pins from sliding along the rolling contact surface regardless of whether they are surface contact or point contact, and preventing the pins from bending beyond the bending angle. If so, various modifications are possible.

  The concave portion and the convex portion are provided on the chain outer diameter side edge portion of each pin or in the vicinity thereof. In addition, the concave portion and the convex portion may be provided over the entire length of each pin, and may be provided at a predetermined location in the length direction of the pin (for example, two locations near both ends).

  The shape of the pins used in one chain is not limited to one type, and two types of pins may be used. In this case, the shape of the convex part and the concave part may be different between the two types of pins, or may be the same shape.

  For example, the link is made of spring steel or carbon tool steel. The material of the link is not limited to spring steel or carbon tool steel, and may of course be other steel such as bearing steel. In the link, the front and rear insertion portions may be independent through holes (links with columns), and the front and rear insertion portions may be one through holes (links without columns). Appropriate steel such as bearing steel is used as the material of the pin.

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

  In this specification, one end side in the length direction of the link is front and the other end side is rear, but this front and rear are for convenience, and the length direction of the link always coincides with the front and rear direction. It doesn't mean that.

  One of the first pin and the second pin is fixed to a pin fixing portion provided at a front portion of a front insertion portion of one link and is movable at a front portion of a rear insertion portion of another link The other side is movably fitted into a pin movable part provided on the rear part of the front insertion part of one link and the rear part of the rear insertion part of the other link. It is preferable that it is fixed to a pin fixing part provided in.

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

  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, and the other is a pin that does not contact the pulley. The pin that contacts the pin is wider in the front-rear direction than the pin that does not contact the pulley, and the protruding edge that extends to contact the inner periphery of the pin fixing portion on the pin that does not contact the pulley It is preferable that all or the tip of the protruding edge portion is a convex portion that fits into a concave portion provided in the pin that contacts the pulley.

  In this way, by increasing the front-rear width of the pin that contacts the pulley, the rigidity of the pin is enhanced, high power transmission is ensured, and the front-rear width of the pin that does not contact the pulley is relatively increased. By making it narrow, an increase in the size of the chain can be avoided. In addition, a pin with a narrow front-rear width has a smaller contact area between the link and a pin than a pin with a wide front-rear width, and as a result, the surface pressure that the link receives from the pin is increased, which is disadvantageous in design freedom However, by providing the protruding edge portion, a contact area with the link is ensured, and the degree of freedom in designing the link can be improved. Thus, the optimum design of the link can be achieved without increasing the size of the link.

  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 above.

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

  According to the power transmission chain of the present invention, the convex portion of the other pin fits into the concave portion of the one pin, thereby preventing over-bending and displacement in the direction along the rolling contact surface. Bending beyond the specified range is prevented, and link deformation and noise generation are suppressed.

  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 according to the present invention. The power transmission chain (1) has front and rear insertion portions (12) and (13) provided at predetermined intervals in the chain length direction. A plurality of links (11) and a plurality of pins (first pin) (14) and an interpiece (second pin) (15) for connecting the links (11) arranged in the chain width direction so as to be bendable in the length direction And. 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 pin (14) is wider in the front-rear direction than the interpiece (15), and extends to the pin (14) side at the upper and lower edges of the interpiece (15). Protruding edges (15a) and (15b) are provided. The front insertion part (12) of the link (11) comprises a pin movable part (16) to which the pin (14) is movably fitted and an interpiece fixing part (17) to which the interpiece (15) is fixed, The rear insertion portion (13) includes a pin fixing portion (18) to which the pin (14) is fixed and an interpiece movable portion (19) to which the interpiece (15) is movably fitted. 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 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 part (13) of one link (11) and fixed to the front insertion part (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).

  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 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 at the straight portion of the chain (1). Is the pitch.

  FIG. 2 shows the relative positional relationship between the link (11) and the pin (14) and the interpiece (15) in the straight part of the chain (1). In the curved part of the chain (1), adjacent links Along with the bending between (11), the pin (14) and the interpiece (15), the upper and lower concave arcuate guide parts (16a) (16b) and the interpiece movable part (19 ) And the upper and lower concave arcuate guides (19a) and (19b), respectively. As a result, the contact position moves upward (the outer diameter side of the chain) from the position indicated by A and B, and the pin (14) and the interpiece (15) are connected to the upper edge portion (the outer diameter side edge of the chain). Part) to change the relative position so that they approach each other. The cross section of the upper edge of the pin (14) that fits with at least the tip of the projecting edge (15a) having an arcuate section on the upper side of the interpiece (15) during this movement. An arcuate recess (14a) is provided.

  FIG. 3 shows the relative positional relationship between the link (11), the pin (14), and the interpiece (15) in the curved portion of the chain (1). When the chain (1) moves from the straight part to the curved part, the position of the interpiece (15) relative to the pin (14) changes, but at that time, the pin (14) and the interpiece in the pin fixing part (18) The contact position with the interpiece (15) in the movable part (19) moves from A to A ′. The bending angle α of the interpiece (15) with respect to the pin (14) is the angle formed between the tangent at the contact position A at the linear portion of the chain (1) and the tangent at the contact position A ′ at the curved portion of the chain (1). It becomes. This bending angle α is determined by the bending angle of the link (11) (the contact position A between the pin (14) and the interpiece (15) in the rear insertion portion (13) of the link (11) positioned relatively rearward). And the front insertion part (12) = the line connecting the contact position A ′ between the pin (14) and the interpiece (15) in the rear insertion part (13) of the link (11) positioned relatively forward (A'-A 'line) and the contact position A' between the pins in the rear insertion portion (13) of the link (11) positioned relatively forward and the pins in the front insertion portion (12) ( 14) and the contact position B ′ between the interpiece (15) and the same angle as the line (A′-B ′ line).

  The bending angle of the interpiece (15) with respect to the pin (14) is set to a predetermined range, for example, 0 to 20 °, and when the chain (1) smoothly transitions from the straight portion to the curved portion, The bending angle falls within this range. However, when this power transmission chain (1) is used in a continuously variable transmission, the inertial force etc. fluctuate due to changes in input torque or gear shifts, and the links (11) or pins (14) and interpiece (15) May over-bend beyond a preset bending angle. In the power transmission chain (1) in which the pin (14) and the interpiece (15) are formed as described above, even in such a case, as shown in FIG. 4 (a), the recess (14a) Since the projecting edge (15a) as the convex part is fitted, the over-bending of the interpiece (15) is prevented, and the concave arcuate guide on the upper side of the interpiece movable part (19) of the link (11) Excessive force does not act on the portion (19a), and string vibration that is a vibration factor is also suppressed. On the other hand, as shown in FIG. 4 (b), the surface of the pin (44) facing the protruding edge (45a) of the interpiece (45) is smooth (or fitted with the protruding edge (45a). In the case of a slight recess that does not fit, it is a two-line contact indicated by C and D (two-point contact in the cross section), and the interpiece (45) is a rolling contact surface with respect to the pin (44). Since it can move along the outer diameter side of the chain, slipping occurs and the link (11) is excessively contacted. In this case, the upper edge portion of the interpiece (45) is pressed against the concave arcuate guide portion (19a) of the interpiece movable portion (19), causing deformation of the link (11) and noise.

  The fitting between the concave portion (14a) and the convex portion (15a) is not limited to the surface contact between the concave portion (14a) and the convex portion (15a) as shown above, but as shown in FIG. Alternatively, a line contact may be made at two locations by fitting the concave section (14b) having a V-shaped section and the convex section (15a) having an arcuate section. Even in this case, the concave part (14b) and the protruding edge part (15a) as the convex part are fitted to each other, thereby preventing the over-bending of the interpiece (15) and the interpiece movable part of the link (11). Excessive force does not act on the concave arcuate guide portion (19a) on the upper side of (19), and string vibration that becomes a vibration factor is also suppressed.

  The recesses (14a) (14b) and the projections (15a) are fitted into the lower portions of the recesses (14a) (14b) and the projections (15a) in FIGS. There may be a gap. Even in this case, the concave portions (14a) and (14b) and the protruding edge portion (15a) as the convex portions are fitted to each other, so that the interpiece (15) is prevented from being excessively bent, and the link (11) is prevented from being bent. Excessive force does not act on the concave arcuate guide portion (19a) on the upper side of the piece movable portion (19), and string vibration that is a vibration factor is also suppressed.

  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 (18) and the interpiece fixing part (17). It is set to 0.005 mm to 0.1 mm. In this way, tension is applied (pre-tensioned) to the assembled chain (1).

  In the above power transmission chain (1), polygonal vibration is caused by repeated vertical movement of the pin, which causes noise, but the pin (14) and the interpiece (15) are relatively rolled and moved in contact. In addition, since the locus of the contact position between the pin (14) and the interpiece (15) with respect to the pin (14) is an involute of the circle, both the contact surfaces of the pin and the interpiece are arcuate surfaces. Compared to the case, vibration can be reduced and noise can be reduced.

  The above-described power transmission chain is used in the CVT shown in FIG. 7. At this time, as shown in FIG. 6, the end face of the interpiece (15) is fixed to the fixed sheave (2a) of the pulley (2) and the movable sheave. The end surface of the pin (14) is in contact with the conical sheave surface (2c) (2d) of the pulley (2) without contacting the conical sheave surface (2c) (2d) of (2b). Power is transmitted by the frictional force. As described above, the pin (14) and the interpiece (15) are guided by the movable parts (16) and (19) to move in rolling contact with each other, so that the sheave surfaces (2c) (2d) of the pulley (2) On the other hand, the pin (14) hardly rotates, the friction loss is reduced, and a high power transmission rate is secured.

  In this CVT, when the input torque changes or a speed change operation is performed, a predetermined bending range is exceeded between the pin (14) and the interpiece (15) and therefore between the links (11). Hyperbending can occur. Since the interpiece (15) is not in contact with the pulley (2), the amount of movement is likely to be larger than that of the pin (14), but the protruding edge fits into the recess as described above. Even if a force that causes the interpiece (15) to move greatly in the interpiece movable part (19) is applied, the interpiece (15) is displaced with respect to the pin (14). There is nothing. Thus, by preventing overbending, an increase in the contact surface pressure of the link (11) is prevented, thereby ensuring excellent durability as a CVT.

  In the above, the pin (14) is provided with only the recesses (14a) and (14b) corresponding to the protruding edge (15a) on the upper side of the interpiece (15). In order to prevent this, the pin (14) may be further provided with a recess corresponding to the protruding edge (15b) on the lower side of the interpiece (15). In the above description, when the upper and lower edges of the interpiece (15) have protruding edges (15a) and (15B), the upper protruding edges (15a) are used as protrusions. The projecting edges (15a) and (15b) of the upper and lower edges of the piece (15) are omitted, and convex portions are formed in the upper and lower intermediate portions of the interpiece (15), and the corresponding concave portions are formed on the pins (14). You may make it form in.

  In addition, one of the pin (14) and the interpiece (15) in one insertion part (12) (13) is not movable with respect to the pin (14), but both are movable. It may be possible (rather than being press-fitted into the pin (14), it is only loosely fitted).

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 side view of the link in the straight portion of the chain. FIG. 3 is an enlarged side view of the link in the curved portion of the chain. FIG. 4 is an enlarged schematic view for explaining the characteristic part of the present invention. FIG. 5 is an enlarged side view showing another embodiment of the pin. 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 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)
(14a) Recess
(15) Interpiece (2nd pin)
(15a) Upper protruding edge (convex)
(15b) Lower protruding edge
(16) Pin movable part
(17) Interpiece fixing part (pin fixing part)
(18) Pin fixing part
(19) Interpiece movable part (Pin movable part)

Claims (4)

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. In the power transmission chain provided with the first pin and the plurality of second pins, the first pin and the second pin are relatively in rolling contact with each other, so that the links can be bent in the longitudinal direction.
A range of a predetermined bending angle of the second pin with respect to the first pin when the power transmission chain shifts from the straight portion to the curved portion is defined, and is provided on one of the first pin and the second pin. the convex portion is fitted in a recess provided in the other, that you prevent bending angle of the second pin to the first pin exceeds a maximum flexion angle in the range of the predetermined bending angle A characteristic power transmission chain.   One of the first pin and the second pin is fixed to a pin fixing portion provided at a front portion of a front insertion portion of one link and is movable at a front portion of a rear insertion portion of another link The other side is movably fitted into a pin movable part provided on the rear part of the front insertion part of one link and the rear part of the rear insertion part of the other link. The power transmission chain of Claim 1 currently fixed to the pin fixing | fixed part provided in. 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, and the other is a pin that does not contact the pulley. the pin towards the contact, the front-rear direction of the width than the pin of the person who does not contact the pulley is made wide, the chain radially outer side edges or near the pins of the person who does not contact the pulley, the pin fixing portion A protruding edge that extends to contact the inner periphery is formed, and all or the tip of the protruding edge is a protrusion that fits into a recess provided on the pin that contacts the pulley. The power transmission chain according to claim 2.   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 any one of claims 1 to 3.

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