JP2010019337A - Power transmission chain and power transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission chain and a power transmitting device reduced in noise by not using pin random arrangement easily causing humming noise at low speed. <P>SOLUTION: In a plurality of links 11, its pitch length is two levels or higher, and they are randomly arranged. A pin 14 is held between pulleys 2 to transmit torque by a frictional force. An inter-piece 15 has a length contacting with the pulley 2, and the arrangement of its contact positions is the same as the contact position arrangement of the pins 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

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. 6, a primary 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 secondary pulley (3) provided on the drive wheel side and an endless power transmission chain (1) bridged between the two, 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 so as to be bendable in the length direction, and are 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. It has been proposed to bend in the length direction, use links with different pitch lengths as a plurality of links, and use pins with different rolling contact surfaces.
JP 2006-97844 A

  In the power transmission chain shown in Patent Document 1, noise can be reduced by randomly arranging a plurality of links having different pitch lengths, and further randomly arranging different pin shapes. Depending on the combination of random arrangements, low-frequency beat noise may occur due to peaks close to each other.

  An object of the present invention is to provide a power transmission chain and a power transmission device that reduce noise without using a pin random arrangement that is likely to cause beat noise at low speeds.

  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. In the power transmission chain, the plurality of links have a pitch length of 2 levels or more and are randomly arranged, and the first pin is a pin that is sandwiched between pulleys and transmits torque, The second pin has a length in contact with the pulley, and the arrangement of the contact positions is the same as the arrangement of the contact positions of the first pins.

  In a conventional power transmission chain, one pin is a pin that contacts a pulley and transmits torque when the chain is used in a continuously variable transmission (hereinafter referred to as “first pin” or “pin”). The other pin is a pin that does not contact the pulley (referred to as an interpiece or a strip, hereinafter referred to as a “second pin” or an “interpiece”). On the other hand, in the power transmission chain of the present invention, the first pin transmits torque, but the second pin comes into contact with the pulley. The contact position array of the second pin is set to be the same as the contact position array of the first pin, and the peak of the sound pressure level of the sound generated when the second pin comes into contact with the pulley is the first pin on the pulley. The sound pressure level of the sound generated by the contact is located at the center between the peaks. As a result, the interval between the generated sounds is reduced, the peak value of the sound is lowered, and the fluctuation of the sound pressure level is also reduced, so that noise can be greatly reduced. The contact position of the second pin can be set to a predetermined position by adjusting the end face shape of the pin.

  Regarding the random arrangement of the configuration other than the pitch length of the link, with respect to the rolling contact surface shape of the first pin and the second pin, the locus of the contact position between the first pin and the second pin is an involute curve and the basic circle radius of the involute No. 2 is randomly arranged, and the end face shape of the pin that contacts the pulley is not required to be randomly arranged with the position contacting the pulley being the second level.

  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 edges (upper and lower edges) 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.

  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. The second pin preferably has a shape narrower than that of the first pin. In this case, the upper and lower edges of the second pin may be provided with protruding edges.

  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, the end face of the first pin is in contact with the conical sheave surface of the pulley of the continuously variable transmission, and the power is 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 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 device of the present invention, since the link pitch length is a random arrangement of two or more levels, sound reduction when the first pin collides with the pulley, particularly the primary peak of the sound pressure level. In addition to this, the second pin is also brought into contact with the pulley, and the arrangement of the contact positions is the same as the contact position arrangement of the first pins. At the same time, the peak value of the sound is lowered and the fluctuation of the sound pressure level is reduced, so that the noise can be greatly reduced.

  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 slightly shorter than the pin (14), and both face 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.

  This power transmission chain (1) is used in the V-type pulley type CVT shown in FIG. 3. At this time, the fixed sheave (2a) and the movable sheave (2b) of the pulley (2) having the pulley shaft (2e) are used. The end surfaces of the pins (14) are in contact with the conical sheave surfaces (2c) and (2d), and power is transmitted by the frictional force generated by the contact. The interpiece (15) hardly contributes to power transmission, but its end surface is formed so as to contact the conical sheave surface (2c) (2d) of the pulley (2).

  Each link (11) has a front column portion (20) for forming the front shape of the front insertion portion (12) and a rear column portion (22) for forming the rear shape of the rear insertion portion (13). And an intermediate column part (21) between the front insertion part (12) and the rear insertion part (13). 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.

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

  As a sound caused by the chain (1), there is a sound when the pin (14) comes into contact (collision) with the pulley (2) (3), and this sound is a contact point P1 of the pin (14) shown in FIG. And an interval corresponding to a distance P between P2 and P2. If the pins (14) are arranged at the same interval, the sound has a sharp peak at a certain frequency. Therefore, the pitch length of the link (11) (distance between AB in FIG. 2) is 2 levels (3 if necessary). The primary peak is reduced by randomly arranging the links (11) having different pitch lengths.

  According to the conventional noise reduction method, it is further attempted to arrange the pin end face shape and the like in two levels at random. However, in the random arrangement of the pin (14) shape, a roaring sound may be generated at a low speed due to adjacent peaks. Therefore, in the power transmission chain (1) according to the present invention, the pin (14) and the pin (14) and the pulley (2) (3) are brought into contact with each other without using the random arrangement of the pin (14) shape. Reduction of the noise that the interpiece (15) collides with the pulleys (2) and (3) is achieved.

  The interval at which the interpiece (15) contacts the pulleys (2) and (3) is a distance Q between the contact points Q1 and Q2 of the interpiece (15) as shown in FIG. The pin (14) and the interpiece (15) are arranged in the order of the pin (14), the interpiece (15), the pin (14), and the interpiece (15) according to the distances P and Q between the respective contact points. (2) A sound is generated by colliding with (3). The interval between the sound from the pin (14) and the sound from the interpiece (15) corresponds to the distance indicated by D in FIG. The distance D can be set to an appropriate value by grinding the end face shape of the interpiece (15) to a predetermined shape (changing the thickness if necessary). The interval at which the pin (14) contacts the pulleys (2) and (3) and the interval at which the interpiece (15) contacts the pulleys (2) and (3) vary depending on the pitch length.

  FIG. 5 shows that when the interpiece (15) is brought into contact with the pulley (2) (3), the pin (14) and the interpiece (15) are connected to the pulley (2) as compared with the conventional one. It is a figure explaining how the sound which collides with (3) changes. In the figure, the alternate long and two short dashes line indicates the collision sound caused by the pin (14) when the interpiece (15) is not in contact. This corresponds to the conventional one, and the pin (14) has a relatively short interval T1 corresponding to a small pitch length and a relatively long interval T2 corresponding to a large pitch length. A sound is generated by collision. A broken line indicates a collision sound caused by the interpiece (15) when the interpiece (15) contacts the pulleys (2) and (3). That is, the level of the impact sound of the interpiece (15) is smaller than that of the pin (14), but, as with the pin (14), a relatively short interval T1 corresponding to a small pitch length and a relative value corresponding to a large pitch length. Therefore, it collides with the pulleys (2) and (3) at a long interval T2 to generate sound. The collision of the interpiece (15) causes the collision energy to be borne by the interpiece (15) as compared to the case of the collision of the pin (14) alone. The pressure level decreases. The arrangement of contact positions of the interpiece (15) is set to be the same as the arrangement of contact positions of the pins (14). As a result, in the case where both the pin (14) and the interpiece (15) are brought into contact with the pulley (2) (3), as shown by the solid line in FIG. The generation interval is halved and the fluctuation of the sound pressure level is reduced. Thereby, the sound resulting from the chain (1) is greatly reduced.

  This power transmission chain (1) holds the required number of pins (14) and interpieces (15) vertically on the assembly jig, and then press-fits one or several links (11) one by one. It is manufactured by doing. 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. Moreover, since the pitch length of the link (11) is a random arrangement of two levels or more, the sound when the pin (14) and the interpiece (15) collide with the pulley (2) (3) is reduced. In particular, the effect of reducing the primary peak of the sound pressure level is increased. In addition, the interpiece (15) is also brought into contact with the pulleys (2) and (3), and the arrangement of the contact positions is the contact of the pins (14). By being made the same as the position arrangement, noise is greatly reduced.

  When used in the CVT, the pin (14) and the interpiece (15) are guided by the movable parts (16) and (19) as described above to move in rolling contact with the pulley (2). The pin (14) hardly rotates with respect to the sheave surfaces (2c) and (2d), the 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 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 view for explaining an interval at which the pin and the interpiece contact the pulley. FIG. 5 is a diagram for explaining the sound pressure level when the pin and the interpiece come into contact with the pulley. FIG. 6 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)
(15) Interpiece (2nd pin)

Claims (2)

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 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. In the power transmission chain provided with the first pin and the plurality of second pins, the first pin and the second pin are in rolling contact with each other, whereby the links can be bent in the length direction.
The plurality of links have a pitch length of 2 levels or more and are randomly arranged. The first pin is a pin that is sandwiched between pulleys and transmits torque, and the second pin is connected to the pulley. A power transmission chain having a contact length and having an arrangement of contact positions the same as a contact position arrangement of first pins.   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 claim 1.

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