JP2006002784A - Power transmitting chain and transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmitting chain capable of suppressing polygonal vibrations and thereby removing the factor of noise emission. <P>SOLUTION: The power transmitting chain 1 is equipped with a plurality of links 11 having through holes 12 and 13 laid in line in front and behind and a plurality of pins 14 and interpieces 15 to couple together the links 11 laid in line across the chain width with possibility of being bent in the longitudinal direction in such an arrangement that the front through hole 12 in one link 11 is mating with the rear through hole 13 in another link 11. The locus of the position where the pin 14 contacts with the interpiece 15 is made involute of a circle, and two sorts of pins 14A and 14B having different basic circle radii of involute are formed. The contacting position h1 of the pin 14A having a greater basic circle radius is made lower than the contacting position h2 of the pin 14B having a smaller basic circle radius. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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. 14, 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, a link arranged in the chain width direction in Patent Document 1 so that a plurality of links having through holes arranged in front and rear, and a front through hole of one link and a rear through hole of another link correspond to each other. A plurality of first pins and a plurality of second pins that are connected to each other so as to be able to bend in the length direction, are fixed to the front through hole of one link and are movably fitted into the rear through hole of another link The first pin and the second pin that is movably fitted in the front through-hole of one link and fixed to the rear through-hole of the other link move relatively in contact with each other. Proposals have been made that can be bent.
Japanese Patent Laid-Open No. 8-31725

  The power transmission chain of Patent Document 1 described above suppresses polygonal vibration caused by the fact that the chain is not a continuous body, and noise of a continuously variable transmission using the same is reduced. In order to improve the quietness and improve the comfort, further noise reduction is preferable.

  Therefore, for example, it is conceivable to reduce noise by forming a pair of first pins and second pins having two different shapes and arranging these pairs at random. However, if the pin shape is changed, it is necessary to change the shape of the through-hole into which the pin is fitted, and the front and rear through-holes correspond to the first set and the second set. After all, four types of links are required, which increases the cost.

  An object of the present invention is to provide a power transmission chain and a power transmission device that can further suppress polygonal vibration, thereby eliminating noise factors, and suppressing cost increase.

  The power transmission chain according to the present invention includes a plurality of links having through holes arranged in the front and rear direction, and links arranged in the chain width direction so that the front through hole of one link and the rear through hole of another link correspond to each other. A plurality of first pins and a plurality of second pins that are flexibly connected in the vertical direction, and are fixed to a front through hole of one link and movably fitted to a rear through hole of another link The second pin fixedly attached to the rear through hole of the other link and movably fitted in the front through hole of one link is relatively rolled and moved so that the links in the longitudinal direction are bent. In a possible power transmission chain, the locus of the contact position between the first pin and the second pin is an involute of a circle, and a set of two types of first and second pins having different basic circle radii of the involute is formed. The involute foundation circle radius of one set is r1, the involute foundation circle radius of the other set is r2, the radial position of the contact point between the pins in the phase θa of the set of the involute foundation circle radius is r1, the involute foundation It is characterized in that r1> r2 and h1 <h2 where h2 is the radial position of the contact point between the pins in the phase θa of the set of the circle radius r2.

  In order to make the locus of the contact position of the pins that relatively move in rolling contact with each other as an involute curve of a circle, for example, the contact surface of one pin has an involute shape having a base circle of radius Rb and center M in cross section. The contact surface of the other pin may be a flat surface (the cross-sectional shape is a straight line). The locus of the contact position between the pins can be an involute curve of a circle even if the contact surfaces of both pins are both curved. In this case, the cross-sectional shape of both pins may be the same. preferable.

  The contact point between the pins changes when the pin moves from the straight portion to the curved portion of the chain, and the predetermined phase θa when obtaining h1 and h2 is selected, for example, as the meshing position with the pulley. . The reference for the radial position of the contact point between the pins may be the lower end surface of the link or the rotation center of the pulley.

  The number of sets of two types of pins may be the same or substantially the same, but one may be about twice or about five times the other. Then, a set of pins having different base circle radii (and thus a set of pins having different contact positions) are randomly arranged. If it does in this way, the moment force which raises a chain at the time of pulley approach of a chain becomes random, and the approach angle of a pin becomes random. Even in a chain straight state, moment force acts randomly.

  It is preferable that the through-holes of the link have substantially the same shape regardless of the basic circle radius of the pin fitted into the hole. “Substantially the same” means that all through hole shapes are within an error range that occurs when attempting to produce the same shape in the usual manner. If the base circle radius is changed while keeping the radial position of the contact point of both pins the same, it will be necessary to change the shape of the through hole accordingly. By appropriately changing the radial position, it is possible to change the base circle radius without changing the through hole shape. As a result, it is not necessary to increase the types of links in order to obtain a random arrangement, thereby preventing an increase in cost.

  Two types of links having different pitches are formed, and these links are preferably arranged at random. A pitch means the space | interval of through-holes, A link of a different pitch can be obtained by changing the space | interval of through-holes with the shape of a through-hole remaining the same. The size of the link itself may or may not be changed according to the pitch. The number of two types of pitches (links) may be the same or substantially the same, but one may be about twice or about five times the other. In addition, the number may be determined so as to correspond to the number of sets of pins, or the number may be determined regardless of the number of sets of pins.

  In the above description, when randomly arranging a set of pins having different shapes and links having different pitches, the number of pairs of pins having the same shape or the number of links having the same shape is a prime number, and the following four It is preferable that at least one (preferably two or more) of the two conditions is satisfied.

A) The number of arrays of similar elements does not appear within a range of ± 5% with respect to an arbitrary point.

B) The number of arrays with the maximum frequency is not more than three times the number of arrays with the minimum frequency.

C) There are more than three types of continuous arrangement numbers of homogeneous elements including different elements.

D) The portion having the rotational symmetry of the array pattern of 60 ° or less does not exceed 50% of the whole.

  In this specification, the term “random sequence” means, in a narrow sense, that at least one of the above four conditions is satisfied. For example, the sequence “abbabb” is provided only at one location, and other locations. If A) holds, it should also be regarded as a random array, and the “random array” includes not only elements that are arranged without periodicity or regularity throughout, It is assumed that only a small part has periodicity or regularity.

  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 that is not in contact with the pin (referred to as an interpiece or strip, hereinafter referred to as an “interpiece”).

  The front through-hole of the link includes a pin fixing portion to which the pin is fixed and an inter-piece movable portion into which the inter-piece is movably fitted. The rear through-hole of the link is a pin into which the pin is movably fitted. The movable part and the interpiece fixing part to which the interpiece is fixed are used. The front and rear through holes may be combined into a single hole.

  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 power transmission chain according to the present invention, one of the pins (interpiece) is shorter than the other pin (pin), and the end surface of the longer pin contacts the conical sheave surface of the pulley of the continuously variable transmission. The power is preferably transmitted by the frictional force caused by 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 of the present invention, the involute basic circle radius of each pair of pins is different, so that the moment force to lift the chain when the chain enters the pulley becomes random, and the pin entry angle becomes random. Since the peak level at a predetermined frequency that occurs with the same basic circle radius can be reliably reduced to a predetermined value or less, resonance due to polygonal vibration can be avoided, thereby causing a chain. Noise can be greatly reduced. In addition, by arranging a set of pins with different contact positions at random, the moment force acts randomly even in a chain linear state, and a greater noise reduction effect can be obtained.

  In addition, by setting r1> r2 and h1 <h2, even if the involute basic circle radius is different, the locus of the contact position between the pins becomes almost equal, and it is necessary to change the shape of the through hole of the link according to the pin. The above effects can be obtained without increasing the number of types of links, that is, without increasing costs.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the left in FIG. 3 is the front and the right is the rear.

  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 through holes (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, the front through hole (12) has a movable pin fixing part (12a) to which the pin (14) (shown by a solid line) is fixed and an interpiece (15) (shown by a two-dot chain line). The rear through hole (13) includes a pin movable portion (13a) and an interpiece (13) in which a pin (14) (shown by a two-dot chain line) is movably fitted. 15) It consists of an interpiece fixing part (13b) to which (shown by a solid line) is fixed. When connecting the links (11) arranged in the chain width direction, the front through hole (12) of one link (11) and the rear through hole (13) of the other link (11) correspond to each other. The links (11) are overlapped, the pin (14) is fixed in the front through hole (12) of one link (11) and is movably fitted into the rear through hole (13) of the other link (11) The interpiece (15) is movably fitted in the front through hole (12) of one link (11) and fixed to the rear through hole (13) of the other link (11). The pins (14) and the interpiece (15) are relatively rolled and brought into contact with each other, whereby the links (11) can be bent in the length direction (front-rear direction).

  The locus of the contact position between the pin (14) and the interpiece (15) relative to the pin (14) is an involute of the circle.In this embodiment, the contact surface (14a) of the pin (14) is As shown in FIG. 4, the cross section has an involute shape having a basic circle with a radius Rb and a center M, and the contact surface (15a) of the interpiece (15) is a flat surface (the cross-sectional shape is a straight line). . As a result, when each link (11) moves from the straight part of the chain (1) to the arc part or from the arc part to the straight part, the interpiece (15) is movable in the front through hole (12). The contact surface (15a) of the pin (14) fixed in the part (12b) is in rolling contact with the contact surface (14a) of the pin (14) (strictly speaking, rolling contact including a slight sliding contact (rolling) In the rear through-hole (13), the contact surface (14a) of the inter-piece (15) is fixed to the inter-piece (15) in which the pin (14) is fixed. It moves in the pin movable part (13a) while being in rolling contact with the contact surface (15a) (strictly, it is rolling contact (rolling and sliding contact) including some sliding contact). In FIG. 3, the portions indicated by reference signs A and B are lines (points in the cross section) where the pin (14) and the interpiece (15) are in contact with each other in the straight portion of the chain (1). Is the pitch in this specification.

  In such a power transmission chain (1), polygonal vibration accompanying the movement locus of the pin shown in FIG. 5 occurs. In FIG. 5, the tangential direction of the pulley and the pin entry direction are different at the biting position where the pin (indicated by a square mark) moves from the straight line portion to the arcuate portion that contacts the pulley. The pin makes contact with the pulley while descending. The amount by which the pin descends when contacting the pulley is shown as the initial biting position change amount. The pin in the straight portion also moves up and down due to the lowering of the pin at the biting position, and this vertical movement amount becomes the amplitude. Polygonal vibrations are generated by such repeated vertical movement of the pins.

  The pin (14) and the interpiece (15) are in rolling contact with each other and the locus of the contact position between the pin (14) and the interpiece (15) with respect to the pin (14) is the involute of the circle. Therefore, the amplitude can be reduced as compared with the case where the contact surfaces of the pin and the interpiece are both arcuate surfaces. However, even with this configuration, when the link (11), the pin (14), and the interpiece (15) are one type and no vibration reduction measures are taken, as shown in FIG. A peak occurs, which is perceived as noise by humans. Therefore, even in the case where the locus of the contact position is an involute of a circle, further reduction of polygonal vibration is desired.

  Therefore, in the power transmission chain according to the present invention, not all links (11), pins (14), and interpieces (15) are formed in the same shape, but in order to avoid resonance due to polygonal vibration, As shown in FIG. 7, two types of pins (14A) (14B) and interpieces (15A) (15B) having different base circle radii R1 or R2 are used, and preferably, as shown in FIG. As shown in FIG. 5, links (11A) and (11B) having different pitches P1 and P2 are used. In addition, in FIG. 7, the shape of the pin (14B) having the basic circle radius R2 is drawn to show that the shape is different from the pin (14A) having the basic circle radius R1, and is different from the actual shape. is doing.

  In the power transmission chain (1) according to the present invention, conventionally, as shown in FIG. 11 (c), all the links, pins and interpieces have the same base circle radius R1 at the same pitch P1, whereas As shown in FIG. 11 (a), the two types of pins (14A) and (14B) shown in FIG. 7 are used, the pitch P1 is all the same, and the involute of the first set of pins (14A) If the basic circle radius is R1, the basic circle radius of the involute of the second set of pins (14B) is R2, the basic circle radius of the involute of the third set of pins (14B) is R2, and the fourth set of pins (14A The base circle radius of the involute of (1) is R1, and the size of the base circle is changed and is arranged in an irregular order (randomly).

  In order to manufacture two types of pins (14A) (14B) and interpieces (15A) (15B) with different base circle radii, for example, the contact surface (14a) of the pin (14A) is formed on the base circle of radius R1. The contact surface (14a) of the pin (14B) is formed in an involute shape having a base circle with a radius R2, and the contact surface (15a) of the interpiece (15A) (15B) is flat. One kind of thing may be used. Pins (14A) (14B) and interpieces (15A) (15B) may have their cross-sectional shapes reversed, and the locus of the contact position between the pins and the interpiece becomes a circular involute, and the pins and the interpiece have the same cross section. You may make it have a shape.

  More preferably, as shown in FIG. 11 (b), the two types of links (11A) and (11B) shown in FIG. 8 and the two types of pins (14A) and (14B) shown in FIG. If the pitch of the first link (11A) is P1 using the piece (15), the pitch of the second link (11B) is P2, the pitch of the third link (11B) is P2, and the fourth The pitch of the link (11A) is P1, and the pitch is changed, and the links are arranged in an irregular order (randomly). In order to manufacture this power transmission chain (1), the contact surface (14a) of the pin (14A) has an involute shape having a foundation circle with a radius R1, and the contact surface (14a) of the pin (14B) has a foundation of a radius R2. Two types of links (11A) and (11B) that are formed in an involute shape with a circle and that have the same shape of the through holes (12) and (13) but have different intervals (and hence pitch) between the through holes (12) and (13) The two types of links (11A) and (11B) and the two types of pins (14A) and (14B) may be combined in an appropriate manner and continued.

  Further, in the power transmission chain (1) according to the present invention, when two types of pins (14A) (14B) having different basic circle radii are used, the shape of the link (11) is as shown in FIG. The front and rear through holes (12) and (13) have the same shape regardless of the involute base circle radius of the pins (14A) and (14B) fitted into the holes (12) and (13). (14A) (14B) and the interpiece (15) are formed so as to be in different positions.

  In FIG. 9, the involute basic circle radius of one pin (14A) shown in FIG. 9A is r1, the involute basic circle radius of the other pin (14B) shown in FIG. The radial position of the contact point of the pin (14A) / interpiece (15A) at the phase θ = θa (for example, the pulley engagement position) of the pin (14A) / interpiece (15A) with radius r1 (link Pin (14B) / interpiece (15B) contact point at the phase θ = θa of the pair of pin (14B) and interpiece (15B) with h1 (θa) as the height from the lower end and r2 of the involute basic circle radius Where r1> r2 and h1 (θa) <h2 (θa) where h2 (θa) is the radial position. Specific numerical values are, for example, r1 = 70 mm, r2 = 51 mm, h1 = 4.17 mm, and h2 = 4.47 mm.

  As shown in FIG. 10, the involute trajectory changes along with the change in the basic circle radius, and the involute curve length increases as the basic circle radius increases. Therefore, it is necessary to increase the height of the through-holes (12) and (13) of the link (11) for those having a large basic circle radius, but by satisfying the condition that h1 <h2 with r1> r2, Different sets of basic circle radii can be obtained without changing the shape of the through holes (12) and (13).

  According to the power transmission chain (1) of the above embodiment, by making the locus of the contact position an involute curve, as shown in FIG. 12, the pins (14A) (14B) and the interpiece (15) are connected to the pulley (2). The chain (1) continues to be pulled in the direction of the straight line L shown by the alternate long and short dash line in the figure, so that the polygonal vibration of the chain (1) due to the biting position and the movement after biting is minimized. Can be suppressed. Then, two kinds of pins (14A) (14B) and interpieces (15) in which the locus of the contact position between the pins (14A) (14B) and the interpiece (15) is an involute of a circle and the basic circle radius of the involute is different. ), And these pins (14A) (14B) and interpieces (15) are randomly arranged, the frequency range of sound generation is different and the sound energy is different. Therefore, the peak of the sound pressure level can be reduced. In addition, by arranging the pairs of pins (14A) and (14B) with different radial positions of the contact points at random, moment force acts randomly even in a chain linear state, and a greater noise reduction effect is obtained. . Furthermore, if the two types of links (11A) and (11B) having different pitches are also randomly arranged, the peak of the sound pressure level can be further reduced. Thus, the sharp peaks in FIG. 6 are greatly reduced by dispersing the sound energy to different frequency bands, and the noise felt by humans is reduced.

  In FIG. 12, the center of the curved portion of the chain is the origin, the direction of the linear portion of the chain is the X axis, the direction orthogonal to this is the Y axis, and the angle between the line connecting the origin and the rolling contact center and the Y axis. Let (phase) be θ. In addition, the contact portion between the pin and the interpiece when the chain is straight is the origin, the linear direction of the chain is the x axis, and the direction perpendicular to this is the y axis, and the pin tangential direction at the contact position between the pin of the chain curve portion and the interpiece If the angle formed by the y-axis is γ, the involute curve of the circle is given by the following equation, where the radius of the base circle is Rb.

x = Rb · (sin γ−γ · cos γ)
y = Rb · (cosγ + γ · sinγ) −Rb
The above power transmission chain is used in the CVT shown in FIG. 14. At this time, as shown in FIG. 13, the interpiece (15) is made shorter than the pin (14), and the interpiece (15) The end surface of the pin (14) is the conical shape of the pulley (2) with the end surface not contacting the conical sheave surfaces (2c) and (2d) of the fixed sheave (2a) and the movable sheave (2b) of the pulley (2). The sheave surfaces (2c) and (2d) are brought into contact with each other, and power is transmitted by the frictional force generated by the contact. As described above, since the pin (14) and the interpiece (15) are in rolling contact 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.

FIG. 1 is a plan view showing a part 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 same. FIG. 4 is a diagram illustrating the basic circle radius of the contact surface. FIG. 5 is a diagram showing the motion trajectory of the pin. FIG. 6 is a graph showing the sound pressure level when the equal pitch arrangement is adopted. FIG. 7 is a diagram illustrating an example in which pins having different shapes are randomly arranged. FIG. 8 is a diagram illustrating an example in which links having different shapes are randomly arranged. FIG. 9 is a diagram showing a pin shape and a link shape of the power transmission chain according to the present invention. FIG. 10 is a diagram showing the relationship between the trajectory of the contact position based on the involute curve and the basic circle radius. FIG. 11 is a diagram showing an example of the pitch, basic circle radius, and random arrangement of the power transmission chain according to the present invention. FIG. 12 is a view showing the state of the pins before and after the power transmission chain according to the present invention is engaged. FIG. 13 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 14 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) (11A) (11B) Link
(12) (13) Through hole
(14) (14A) (14B) Pin (1st pin)
(15) (15A) (15B) Interpiece (2nd pin)

Claims (4)

  A plurality of links having through holes arranged in the front-rear direction, and links arranged in the chain width direction are connected to be able to bend in the length direction so that the front through hole of one link and the rear through hole of another link correspond to each other. A first pin having a plurality of first pins and a plurality of second pins, fixed to a front through hole of one link and movably fitted to a rear through hole of another link, and the front through hole of the one link The power transmission chain in which the links can be bent in the longitudinal direction by relatively rolling and moving with the second pin fixedly fitted to the rear through hole of the other link. , The locus of the contact position between the first pin and the second pin is an involute of a circle, and two sets of first and second pins having different basic circle radii of the involute are formed. The radial position of the contact point between the pins in the phase θa of the set of the circle radius r1, the other set of involute basic circle radius r2, and the involute basic circle radius r1 is h1, and the phase of the set of involute basic circle radius r2. A power transmission chain, wherein r1> r2 and h1 <h2 are satisfied, where h2 is a radial position of a contact point between pins at θa.   The power transmission chain according to claim 1, wherein the through-holes of the link have substantially the same shape regardless of the basic circle radius of the pin fitted into the hole.   The power transmission chain according to claim 1 or 2, wherein two types of links having different pitches are formed, and these links are arranged at random.   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 any one of claims 1 to 3.

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