JP4770610B2 - 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. 6, a drive pulley (2) provided on the engine side having a fixed sheave (2a) and a movable sheave (2b), a fixed sheave (3b) and a movable sheave (3a) and a driven pulley (3) provided on the drive wheel side and an endless power transmission chain (1) spanned between them, and a movable sheave (2b) (3a) by a hydraulic actuator The chain (1) is clamped with hydraulic pressure by moving it toward and away from the fixed sheave (2a) (3b), and this clamping force makes contact between the pulley (2) (3) and the chain (1). It is known that a load is generated and torque is transmitted by the frictional force of the contact portion.

  As shown in FIG. 7, the power transmission chain (1) includes a plurality of links (31A) (31B) having front and rear insertion portions (32) and (33) through which pins (34) and (35) are inserted. Links (31A) (31B) aligned in the chain width direction so that the front insertion part (32) of the other link (31A) (31B) and the rear insertion part (33) of the other link (31A) (31B) correspond to each other A plurality of first pins (34) and a plurality of second pins (35) which are connected to each other so as to be able to bend in the length direction, fixed to the front insertion portion (32) of one link and other links ( The first pin (34) movably fitted in the rear insertion part (33) of 31A) (31B) and the front insertion part (32) of one link (31A) (31B) are movably fitted. In addition, when the second pin (35) fixed to the rear insertion portion (33) of the other link (31A) (31B) is relatively rolled and moved in contact, the length of the links (31A) (31B) is increased. One that can be bent in a direction is known (see Patent Document 1).

Patent Document 1 proposes to use two types of links (31A) and (31B) having different pitch lengths in the power transmission chain (1). That is, in FIG. 7, the pitch length of one link (31A) is P1, and the pitch length of the other link (31B) is P2, thereby reducing noise.
JP 2006-002783 A

  In the power transmission chains with different pitch lengths described above, every time the size (chain total length) changes, two types of links are designed. As a result, in order to produce chains of many sizes, many types of links are used. There is a problem that it is difficult to manage and the cost is high.

  An object of the present invention is to provide a power transmission chain and a power transmission device that suppress an increase in the types of links when manufacturing chains of a large number of sizes, thereby reducing the labor and cost of management.

  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 are composed of two types of basic links, most of which have different pitch lengths. The total length of the chain is L, the number of link rows consisting of basic links of the pitch length Pa is Na, and the pitch length Pb. An adjustment link having a pitch length satisfying L− (Na × Pa + Nb × Pb) is added, where Nb is the number of link trains of the basic links. It is.

  The adjustment links are preferably arranged in only one of all the link columns, but may be arranged in two or three of all the link columns as necessary. The pitch length of the adjustment link may be larger or smaller than the pitch length of the two types of basic links.

  In the above chain manufacturing method, when a standard chain having a predetermined total length already exists, an adjustment value of the pitch length is obtained from the total length of the chain that needs to be newly manufactured and the two types of pitch lengths of the standard chain. And a step of adding the adjustment value to one of the two pitch lengths to obtain the pitch length of the adjustment link.

  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.

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

  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 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 device of the present invention, it is possible to reduce noise by using two types of basic links having different pitch lengths, and by using two types of basic links in common and using adjustment links, a large number of sizes can be obtained. When the chain is manufactured, it is possible to suppress an increase in the types of links, thereby reducing the labor and cost of management.

  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 pins (first pins) (14) for connecting a plurality of links (10), (11), and (20) and links (10), (11), and (20) arranged in the chain width direction so that they can be bent in the length direction. ) 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 this chain, two types of links (10), (11), and (20) that have different pitch lengths adjust the fractions that are generated when a chain of a different size is produced with the basic links (10) and (11). An adjustment link (20) is used. The adjustment link (20) is used in only one link row among all the link rows, and any one of the basic links (10) and (11) is used in the remaining link rows.

  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, in the front insertion part (12) of one basic link (11), the pin movable part (16) and the interpiece (15) to which the pin (14) is movably fitted are fixed. It consists of an interpiece fixing part (17), and the rear insertion part (13) includes an interpiece movable part (a pin fixing part (18) to which the pin (14) is fixed and an interpiece movable part to which the interpiece (15) is movably fitted. 19).

  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.

  As shown in FIG. 3, the other basic link (10) and the adjustment link (20) have the same shape as the one basic link (11) shown in FIG. 2 except that the pitch length is different. The other basic link (10) has a longer pitch than the one basic link (11), and the front insertion portion (12) and the rear insertion portion (13) of the other basic link (10) The longitudinal length of the pillar portion (22) between them is the longitudinal length of the pillar portion (21) between the front insertion portion (12) and the rear insertion portion (13) of one basic link (11). In comparison, it is made longer by the difference in pitch length. The pitch length of the adjustment link (20) is different from those of the two types of basic links (10) and (11), as will be described later. The two types of basic links (10) and (11) are arranged over the entire length of the chain (1) by a predetermined arrangement pattern (random arrangement), and the adjustment link (20) has only one link row. It is a link. That is, for the portions not shown in FIGS. 1 and 3, any one of the basic links (10) and (11) is used.

  When connecting the links (10) (11) (20) aligned in the chain width direction, the front insertion part (12) of one link (10) (11) (20) and the other link (10) (11) (20) The links (10), (11), and (20) are overlapped so that the rear insertion part (13) corresponds to each other, and the pin (14) is located after one link (10), (11), and (20). It is fixed to the insertion part (13) and is movably fitted to the front insertion part (12) of another link (10) (11) (20), and the interpiece (15) is connected to one link (10) (11 ) (20) is movably fitted to the rear insertion portion (13) and fixed to the front insertion portion (12) of the other links (10) (11) (20). Then, the pin (14) and the interpiece (15) are relatively rolled and brought into contact with each other, whereby the links (10), (11), and (20) can be bent in the length direction (front-rear direction). The

  At the boundary between the pin fixing part (18) of the link (10) (11) (20) and the interpiece movable part (19), the concave and circular guide parts (19a) above and below the interpiece movable part (19) Upper and lower convex arc-shaped holding portions (18a) and (18b) are provided which hold the pin (14) fixed to the pin fixing portion (18), respectively, connected to (19b). 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). Thus, when each link (10) (11) (20) 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) ) Moves in the pin movable part (16) while the rolling contact (including some sliding contact) of the interpiece (15) with the contact surface of the interpiece (15) in the fixed state. In the insertion part (13), the interpiece (15) rolls in contact with the contact surface of the pin (14) with respect to the pin (14) fixed in the interpiece movable part (19) (somewhat Move (including sliding contact).

  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. In addition, because two types of basic links (10) and (11) with different pitch lengths are randomly arranged, the period of sound generation is shifted, the sound energy is distributed in different frequency bands, and the sound pressure level The peak is reduced, and the noise reduction effect is further improved.

  The power transmission chain (1) is manufactured in the following steps as shown in FIG.

  First, a standard chain is designed (S1). At this time, links having different pitch lengths are designed under the condition that the total length is L0 with respect to the total length L0 of the standard chain (S2), and a random arrangement using them is examined (S3). The random array is not a regular array such as aabaabaab but an irregular such as aababbbbbbabaab, where a is a link string consisting of one link (11) and b is a link string consisting of the other link (10). An appropriate arrangement is selected in consideration of the noise reduction effect. At the same time, an appropriate pitch length is examined, and durability and the like are taken into consideration, and two types of pitch lengths Pa and Pb and the number of link rows Na and Nb of the pitch length are determined. In this way, the specification of the standard chain is determined, and an array (pitch length and number of link columns) satisfying L0 = Na × Pa + Nb × Pb, where the number N of link columns is N = Na + Nb, is determined (S4). This standard chain consists only of the basic links (10) and (11), and the adjustment link (20) is not used.

  Next, a new-sized chain having a total length L1 different from that of the standard chain is designed (S5). At this time, the two types of pitch lengths Pa and Pb are not changed (S6). In other words, in the past, every time a new size was designed, the above-described pitch length study (S2) to specification determination (S4) were repeated, but the pitch length study (S2) was omitted. Then, random arrangement is examined under the condition of diverting the basic links (10) and (11) (S7). As a result, the numbers Na ′ and Nb ′ of the link rows of the basic links (10) and (11) are obtained. However, since the conventional ones are used as the pitch lengths Pa and Pb, fractions are generated. become. This fraction = adjustment value Δ is obtained by L1− (Na ′ × Pa + Nb ′ × Pb) (S8). This Δ also changes depending on what value Na ′ and Nb ′ are set, but there are a large number of options for the arrangement of the random sequence, and it is not possible to keep the absolute value of Δ within a predetermined range. Easy. Thereafter, the pitch length of the adjustment link (20) may be obtained as P1 = Pa + Δ or Pb + Δ (S9). Which of Pa + Δ and Pb + Δ is selected is arbitrary. As a result, the array (pitch length and the number of link columns) satisfying L1 = Na ′ × Pa + Nb ′ × Pb + P1 is determined, where the number N ′ of link columns is N ′ = Na ′ + Nb ′ (S10).

  This power transmission chain (1) holds the required number of pins (14) and interpieces (15) vertically on a table, and then links (10), (11), (20) one by one or several Manufactured by press-fitting together. 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).

  The power transmission chain described above is used in the CVT shown in FIG. 6. At this time, as shown in FIG. 5, 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 the above description, the case where the projecting edges (15a) and (15b) are provided on the upper and lower edges of the interpiece (15) has been described. Even so, the same effect can be obtained by adding an adjustment link different from the two types of links (31A) and (31B).

FIG. 1 is a plan view showing a part of one embodiment of a power transmission chain according to the present invention. FIG. 2 is an enlarged perspective view of the same. FIG. 3 is an enlarged side view of the link. FIG. 4 is a flowchart for explaining a method of manufacturing a power transmission chain according to the present invention. FIG. 5 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 6 is a perspective view showing a continuously variable transmission. FIG. 7 is a plan view showing a part of an embodiment of a conventional power transmission chain.

Explanation of symbols

(1) Power transmission chain
(2) (3) Pulley
(2a) (3b) Fixed sheave
(2b) (3a) Movable sheave
(2c) (2d) Conical sheave surface
(10) (11) (20) links
(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 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.
The plurality of links are composed of two types of basic links, most of which have different pitch lengths, and the total number of link rows consisting of basic links with a total length of L and a pitch length of Pa is Na, and a link row of basic links with a pitch length of Pb. A power transmission chain, wherein an adjustment link having a pitch length satisfying L− (Na × Pa + Nb × Pb) is added, where Nb is the number of the power transmission chain.   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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