JP2009138802A - Driving force transmission chain - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving force transmission chain capable of restraining chord vibration, while minimizing reduction in transmission efficiency of driving force. <P>SOLUTION: A silent chain 100 has a plurality of meshing links 10A and 10B having a pair of insertion holes, and a plurality of connection pins 20 respectively inserted into the insertion holes, and is formed in an annular shape by mutually rotatably connecting the respective meshing links 10A and 10B by the connection pins 20. The meshing link 10B is provided with an engaging part 13 for engaging with the meshing link 10A when a relative bending angle with the meshing link 10A turnably connected by the same connection pins 20 is less than a predetermined angle θ and releasing its engagement when the relative bending angle is the predetermined angle θ or more while increasing frictional force acting between these meshing links 10A and 10B. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes a plurality of link members having a pair of insertion holes and a plurality of connection pins respectively inserted into the insertion holes, and each link member is rotatably connected to each other by the connection pins. And a driving force transmission chain that is wound around a plurality of sprockets and transmits a driving force between the sprockets.

  In such a driving force transmission chain, the chain and the sprocket may be disengaged, and the chain may vibrate in a region where the chain is separated from the sprocket between a pair of sprockets, a so-called inter-axis region. . Such string vibration of the chain is caused by resonance caused by the relationship between the vertical movement of the chain that occurs when the sprocket and the chain are engaged and when the chain is released, and the natural frequency of the chain. It has become.

Therefore, in order to suppress such string vibration, Patent Document 1 has a spring member interposed between each link member, and the frictional force between adjacent link members is increased by the elastic force of this spring member. Is described. A chain 1 described in Patent Document 1 is a silent chain in which a mesh piece 3 formed on each link member 2 meshes with a sprocket 4 as shown in FIG. 9. And the spring member 6 is interposed between the some link members 2 connected by the connection pin 5 in the state laminated | stacked on the plate | board thickness direction as FIG. 10 shows. As a result, a pressing force acts on each link member 2 as indicated by an arrow in FIG. 10 due to the elastic force of the spring member 6, and the frictional force acting between the link members 2 increases. By increasing the frictional force acting between the link members 2 in this way, the rotational resistance of the link member 2 is increased, and in the inter-axis region where the sprocket 4 is separated as shown in FIG. The string vibration of the chain 1 can be suppressed.
Japanese Patent Laid-Open No. 10-54445

  However, when the frictional force acting between the adjacent link members 2 is increased by interposing the spring member 6 between the link members 2 as described above, the portion A surrounded by a two-dot chain line in FIG. When the chain 1 is wound around the sprocket 4 from the inter-axis region, and the rotational resistance of the link member 2 is increased when the chain 1 is separated from the sprocket 4 and proceeds to the inter-axis region as in part B. As a result, the transmission efficiency of the driving force is reduced.

  Such a problem is not limited to the silent chain that meshes with the sprocket 4 via the meshing piece 3 formed on the link member 2 as described above, but the sprocket via a roller that is externally fitted to a connecting pin that couples the link member. The roller chain that meshes with the roller chain is generally common.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a driving force transmission chain capable of suppressing string vibration while suppressing a decrease in driving force transmission efficiency as much as possible.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 includes a plurality of link members having a pair of insertion holes and a plurality of connection pins respectively inserted into the insertion holes, and each link member can be rotated with respect to each other by the connection pins. In a driving force transmission chain that is formed into an annular shape by being connected and wound around a plurality of sprockets to transmit the driving force between the sprockets, the link member can be rotated by the same connecting pin. When the relative bending angle with the other linked members is less than a predetermined angle, the frictional force acting between the linked members is increased by engaging the other link members, while the relative The gist of the present invention is that an engaging portion is provided to release the engagement when the bending angle is greater than or equal to a predetermined angle.

  According to the above configuration, the relative bending of the link members connected by the same connecting pin is formed in a substantially linear shape in the inter-axis region until the meshing with one sprocket is released and the other sprocket is wound. When the angle is small, the engaging portion is engaged with another link member connected by the same connecting pin, and the frictional force between the link members is increased. On the other hand, when the chain starts to wrap around the sprocket and the bending angle becomes a predetermined angle or more, the engagement of this engaging portion is released and the frictional force generated between the link members is reduced. It will turn. That is, according to the first aspect of the present invention, the rotation resistance of the link member is increased in the inter-axis region, while the rotation resistance can be decreased when the chain is wound around the sprocket, and the drive String vibration can be suppressed while suppressing a decrease in force transmission efficiency as much as possible.

  The predetermined angle is set to a value smaller than the bending angle of the link member when the chain is wound around the sprocket and meshed. Further, as the predetermined angle is set to a smaller value, the range in which the engagement portion is disengaged when the link member rotates about the connecting pin becomes wider, so that the transmission efficiency of the driving force is increased. The effect of suppressing the decrease is increased. Therefore, in order to improve transmission efficiency, it is desirable to set the predetermined angle as small as possible.

  According to a second aspect of the present invention, in the driving force transmission chain according to the first aspect, the link members are rotatably connected by the connection pins in a state of being alternately stacked, and the sprocket and A meshing piece that can be meshed and has a shape whose tooth width is narrower toward the distal end side, and the engagement portion is located at the distal end portion of the meshing piece and is directed from the meshing piece to another meshing piece adjacent thereto. The gist is that it is formed so as to protrude.

  Silent chains, i.e., chains in which link members are alternately stacked and connected so as to be rotatable by a connecting pin, and each of the link members is formed with an engaging piece protruding so as to engage with the sprocket, The shaft of the connecting pin that is the rotation center of the link member is formed by forming the engaging portion so as to protrude from the tip end portion of the engaging piece toward the engaging piece adjacent thereto as in the configuration according to claim 2. The engaging portion can be formed at a position away from the center. Thereby, when the engaging part is engaged, a larger rotational resistance is generated by the frictional force acting on the engaging part, and the string vibration of the chain can be suitably suppressed.

  Further, according to the above configuration, since the engagement portion is provided on the engagement piece that can be engaged with the sprocket and the tooth width becomes narrower toward the tip end side, and this is engaged with the adjacent engagement piece, the link member. The portion where the engagement occurs with the rotation is limited to the overlapping range of these meshing pieces. Further, since the engagement piece has a shape in which the tooth width is gradually narrowed toward the distal end thereof, the engagement portion is provided at the distal end portion of the engagement piece as in the above configuration, so that the engagement member is engaged with the rotation of the link member. It is possible to limit the portion where the coupling occurs to a narrower range where the tips with narrow tooth width overlap. That is, according to the structure of the said Claim 2, the range used as the state by which engagement of the engaging part was cancelled | released becomes wide, and the fall of the transmission efficiency of a driving force can be suppressed suitably.

  According to a third aspect of the present invention, in the driving force transmission chain according to the second aspect, the engagement portion is formed by bending the distal end portion of the engagement piece toward the distal end portion of the engagement piece adjacent thereto. The gist is to have.

  In the case of providing the engaging portion that protrudes from the tip end portion of the meshing piece toward the adjacent meshing piece as in the invention described in claim 2, the tip portion of the meshing piece as in the invention described in claim 3 Can be bent toward the adjacent engaging piece to form the engaging portion. If the engagement portion is formed by bending the tip of the engagement piece in this way, the engagement portion can be formed when the link member is formed by punching with a press machine or the like. Become.

  According to a fourth aspect of the present invention, in the driving force transmission chain according to the first aspect, the link members are rotatably connected by the connecting pins in a state where they are alternately stacked, and can be engaged with the sprocket. The sprocket and the meshing link are engaged with the sprocket by a meshing link having a meshing piece whose tooth width is narrower toward the tip side, and the meshing link and the splicing pin together with the meshing link. A guide link that suppresses a shift from the guide link, and the engaging portion is positioned to face the front end portion of the meshing piece in the guide link and protrudes from the guide link toward the front end portion of the meshing piece. The gist is to be formed.

  According to a fifth aspect of the present invention, in the driving force transmission chain according to the second or fourth aspect, the engaging portion protrudes toward a tip end portion of the meshing piece in the adjacent meshing link. It is the gist that it is the convex part formed in this way.

  In addition to the meshing link provided with the meshing piece that can mesh with the sprocket as the link member as in the invention of the fourth aspect, the meshing link and the coupling pin are rotatably connected by the coupling pin and engaged with the sprocket. In the case where a guide link that suppresses the meshing link from shifting from the sprocket is provided, a configuration in which an engaging portion is formed on the guide link may be employed. In the case of adopting such a configuration, as in the configuration described in claim 4, the engaging portion is located at a position facing the tip portion so as to protrude from the guide link toward the tip portion of the adjacent meshing piece. In the same manner as in the second aspect of the present invention, in the inter-axis region, the engaging portion is engaged with the tip end portion of the meshing piece to increase the rotation resistance of the link member, while the chain becomes the sprocket. When starting to wind, this engagement is released, and the rotational resistance can be lowered.

  In addition, as a specific configuration of the engaging portion, a convex portion that protrudes toward the tip end portion of the meshing piece in the adjacent meshing link is formed as in the invention described in claim 5, and this is formed into the engaging portion. It can be.

  According to a sixth aspect of the present invention, in the driving force transmitting chain according to the fifth aspect, the friction force acting between the adjacent engaging links increases as the bending angle decreases. The gist is that the surface is inclined.

The gist of the invention described in claim 7 is the driving force transmitting chain according to claim 6, wherein the convex portion is formed of a hemispherical protrusion.
According to the structure of the said Claim 6, engagement is started smoothly as the bending angle of the link member connected with the same connection pin becomes small, and the frictional force by the effect | action of an engaging part gradually becomes. As the bending angle increases, the frictional force gradually decreases and the engagement is smoothly released. Thereby, the vibration of the chain concerning the engagement of the engaging portion and the releasing operation thereof can be suppressed.

  Specifically, by forming a hemispherical protrusion on the surface of the link member as in the invention described in claim 7, the frictional force acting on the link member increases as the link member bending angle decreases. It is possible to form a convex portion having an inclined surface.

(First embodiment)
Hereinafter, a first embodiment in which a driving force transmission chain according to the present invention is embodied as a silent chain that meshes with a sprocket via a meshing piece formed on a link member will be described with reference to FIGS. To do. FIG. 1 shows a top view of the silent chain 100 of the present embodiment. 2A and 2B are perspective views of the meshing links 10A and 10B as link members constituting the silent chain 100, and FIG. 2A is a perspective view of the meshing link 10A and FIG. ) Is a perspective view of the meshing link 10B.

  As shown in FIG. 1, the silent chain 100 is formed by connecting a plurality of meshing links 10 </ b> A, each having a pair of insertion holes 11, and a meshing link 10 </ b> B so as to be rotatable with each other by a connecting pin 20. . In the silent chain 100 of the present embodiment, as shown in FIG. 1, the mesh link 10 </ b> A is disposed on the inner portion in the width direction (vertical direction in FIG. 1) of the silent chain 100, The meshing link 10B is disposed in the portion.

  As shown in FIGS. 2A and 2B, the meshing links 10A and 10B are formed in a thin plate shape, and two insertion holes 11 are formed respectively. Further, the meshing links 10A and 10B each include two chevron-shaped meshing pieces 12 whose tooth widths W gradually narrow toward the tip side (downward in FIG. 2).

  Further, as shown in FIG. 2B, in the meshing link 10B, the tip portions of the pair of meshing pieces 12 are bent in the same direction, and this portion is meshed with the meshing link 10A as shown in FIG. And the engagement portion 13 that protrudes toward the engagement piece 12 of the adjacent engagement link 10A.

  The meshing links 10A and 10B are manufactured by punching a metal thin plate with a press. And the engaging part 13 in the meshing link 10B is formed by bending the front-end | tip part of the meshing piece 12 in the case of this press.

The meshing links 10A and 10B formed in this way are rotatably connected by the connecting pin 20 in a state where they are alternately overlapped as shown in FIG.
In the silent chain 100 of the present embodiment, since the distal end portions of the two engagement pieces 12 of the engagement link 10B are bent into the engagement portion 13, the silent chain 100 is shown on the right side of FIG. In the portion where is substantially linear, the engaging portion 13 formed on the meshing link 10B is engaged with the meshing piece 12 of the adjacent meshing link 10A. As a result, a frictional force acts between the engaging portion 13 of the meshing link 10B and the meshing piece 12 of the meshing link 10A, and the rotational resistance between the meshing link 10A and the meshing link 10B increases. .

  Further, when the engaging portion 13 is engaged in this way, a pressing force acts on each meshing link 10A as shown by an arrow in FIG. 1, and the meshing link having the engaging portion 13 by this pressing force. Not only between 10B and the meshing link 10A with which it directly engages, but also the rotational resistance between each meshing link 10A increases.

  On the other hand, in the portion where the silent chain 100 is bent as shown on the left side of FIG. 3 and the relative bending angle of the mesh links 10A and 10B connected by the same connecting pin 20 is equal to or larger than the predetermined angle θ, The front end portion of the engagement piece 12 in the engagement link 10A and the engagement portion 13 in the engagement link 10B do not overlap, and the engagement between the engagement portion 13 of the engagement link 10B and the engagement piece 12 of the engagement link 10A is released. become.

  As a result, the rotational resistance between the meshing link 10A and the meshing link 10B decreases, and the pressing force acting on each meshing link 10A decreases, and between the meshing links 10A that have increased due to this pressing force. Rotational resistance of the motor is also lowered.

According to the first embodiment described above, the following effects can be obtained.
(1) When the silent chain 100 is substantially linear in the inter-axis region and the relative bending angle of the mesh links 10A and 10B connected by the same connecting pin 20 is small, the engaging portion 13 is adjacent. The engagement link 10A is engaged, and the frictional force between the engagement links 10A and 10B is increased. On the other hand, when the silent chain 100 starts to wind around the sprocket and the bending angle becomes equal to or larger than the predetermined angle θ, the engagement portion 13 is disengaged and the frictional force generated between the meshing links 10A and 10B is reduced. Therefore, the meshing links 10A and 10B can be easily rotated. That is, according to the silent chain 100 of the present embodiment, the rotational resistance of the meshing links 10A and 10B is increased in the inter-axis region, while the rotational resistance can be decreased when the silent chain 100 is wound around the sprocket. Thus, string vibration can be suppressed while suppressing a decrease in transmission efficiency of the driving force as much as possible.

  The predetermined angle θ is set to a value smaller than the bending angle of the meshing links 10A and 10B when the silent chain 100 is wound around and meshed with the sprocket. Further, the smaller the predetermined angle θ, the wider the range in which the engagement portion 13 is disengaged when the meshing links 10A and 10B rotate about the connecting pin 20 as an axis. The effect of suppressing a decrease in the transmission efficiency of the transmission is increased. Therefore, in order to improve transmission efficiency, it is desirable to adjust the size of the engaging portion 13 so that the predetermined angle θ is reduced.

  (2) Since the front end portion of the engagement piece 12 in the engagement link 10B is the engagement portion 13 that protrudes toward the engagement piece 12 of the engagement link 10A adjacent thereto, the connection that is the rotation center of the engagement links 10A and 10B An engaging portion 13 is formed at a position further away from the axis of the pin 20. Thereby, when the engaging portion 13 is engaged, a larger rotational resistance is generated by the frictional force acting on the engaging portion, and the string vibration of the chain can be suitably suppressed. .

  In addition, since the engaging portion 13 is provided on the meshing piece 12 whose tooth width W becomes narrower toward the tip side and is engaged with the adjacent meshing piece 12, the meshing links 10A and 10B are rotated. Thus, the portion where the engagement occurs is limited to the overlapping range of the engagement pieces 12. Further, since the mesh piece 12 has a shape in which the tooth width W is gradually narrowed toward the tip, by providing the engagement portion 13 at the tip of the mesh piece 12, the mesh links 10A and 10B are rotated. Thus, the portion where the engagement occurs can be limited to a narrower range where the tip ends overlap. That is, the range in which the engagement portion 13 is disengaged is widened, and a reduction in driving force transmission efficiency can be suitably suppressed.

  (3) A silent chain is known in which a spring member is interposed between link members to increase the frictional force acting between the link members and suppress string vibration. In this way, the spring member is interposed. In the configuration, when the link member is connected by the connecting pin, the link member is pressed with the spring member sandwiched between the link members, and the connecting pin is inserted while the spring member is deformed. There is a need. Therefore, the position of the link member is likely to shift due to the elastic force of the spring member. On the other hand, in the silent chain 100 of the present embodiment, when the interlocking links 10A and 10B are connected by the connecting pin 20, the adjacent interlocking link 10A and the interlocking link 10B are inserted into the insertion hole 11. By inserting the connecting pin in a state bent to the center, the engaging portion 13 can be assembled without being engaged with the meshing piece 12. Therefore, the positions of the meshing links 10A and 10B are not easily displaced, and assembly can be easily performed.

  (4) The engagement portion 13 is formed by bending the tip end portion of the engagement piece 12 toward the adjacent engagement piece 12. If the engaging portion 13 is formed by bending the distal end portion of the engagement piece 12 as described above, the engagement portion 13 is also formed when the engagement link 10B is formed by punching with a press or the like as described above. Can be formed, and the manufacturing process of the link member can be simplified.

The first embodiment can also be implemented in the following forms that are appropriately modified.
In the above-described embodiment, the configuration is shown in which the engaging portion 13 protrudes toward the meshing piece 12 of the adjacent meshing link 10A by bending the tip of the meshing piece 12 in the meshing link 10B. As shown in a), it is also possible to adopt a configuration in which a convex portion 113 made of a hemispherical protrusion is formed at the distal end portion of the engagement piece 12 and this is used as an engaging portion.

  When such a configuration is adopted, as shown in FIG. 4B, the convex portion 113 has a sloped surface. Thereby, as the bending angle of the meshing links 10A and 10B decreases, the meshing link 10A moves on the convex portion 113 as shown by the two-dot chain line in FIG. In this case, the engagement is smoothly started as the bending angle becomes smaller, and the frictional force due to the action of the engaging portion gradually increases. On the other hand, when the bending angle increases, the engagement is smoothly released accordingly. Thereby, in addition to the effects of (1), (2), and (3) according to the first embodiment, the vibration of the silent chain 100 related to the engaging operation of the convex portion 113 and the releasing operation thereof is suppressed. Will be able to.

  In addition, the shape of the convex portion 113 is not limited to the hemispherical shape as described above. In addition to the hemispherical shape, for example, the triangular link shape, the cross-sectional trapezoidal shape, etc. What is necessary is just to have the shape where the surface inclined so that the frictional force which acts between 10A of meshing links to increase may become large.

-Even if the convex part 113 does not have the inclined surface as mentioned above, if it is formed so that it may protrude toward the front-end | tip part of the meshing piece 12 in 10 A of adjacent meshing links, it is a meshing link. The rotational resistance acting between the meshing links 10A and 10B can be changed by the bending angles of 10A and 10B.
(Second Embodiment)
A silent chain according to a second embodiment that embodies the driving force transmission chain according to the present invention will be described below with reference to FIGS. In addition, about the member similar to 1st Embodiment, the detailed description is omitted only by attaching | subjecting the same code | symbol, and it demonstrates centering on difference between both. 5 is a front view of the silent chain 200 according to the present embodiment, FIG. 6A is a cross-sectional view of the silent chain 200 taken along the line aa in FIG. 5, and FIG. It is sectional drawing of a bb line direction.

  As shown in FIG. 5, in the silent chain 200 of the present embodiment, an outer guide link 30 is provided in place of the meshing link 10B in the first embodiment. The outer guide link 30 has a thin plate shape as in the meshing link 10 </ b> B in the first embodiment, has a pair of insertion holes, and is disposed in an outer portion of the silent chain 200.

  The outer guide link 30 does not have a meshing piece as shown in FIG. 5, and extends toward the sprocket 40 so as to cover the meshing piece 12 of the meshing link 10A. Therefore, the outer guide link 30 faces the side surface of the sprocket 40 in a state where the silent chain 200 is wound around the sprocket 40 as shown in FIG. Accordingly, in the silent chain 200, the outer guide link 30 is engaged with the side surface of the sprocket 40, so that the silent chain 200 is prevented from being displaced from the sprocket 40 and falling off.

  Further, as shown in FIGS. 5 and 6B, the outer guide link 30 has a bending angle between the outer guide link 30 and the meshing link 10A substantially zero, that is, when the silent chain 200 is substantially linear. In addition, a hemispherical convex portion 33 is provided at a position facing the tip end portion of the engagement piece 12 in the adjacent engagement link 10A. In FIG. 5, for convenience of explanation, the convex portion 33 is illustrated as being large, but it is desirable that the convex portion 33 be as small as possible so that the engagement range with the engagement piece 12 is narrowed.

  Since the convex portion 33 is formed on the outer guide link 30 as described above, in the silent chain 200 of the present embodiment, the silent chain 200 is substantially linear as shown on the right side of FIG. In the portion where the protrusion is formed, the convex portion 33 formed on the outer guide link 30 engages with the meshing piece 12 of the adjacent meshing link 10A. Thereby, frictional force comes to act between the convex part 33 and the meshing piece 12 of the meshing link 10A, and the rotational resistance between the meshing link 10A and the outer guide link 30 increases.

  Further, by engaging the projections 33 in this way, a pressing force is applied to each meshing link 10A as shown by an arrow in FIG. 6B, and this pressing force causes the outer guide link 30 and this to move. Not only between the meshing links 10A directly engaged but also the rotational resistance between the meshing links 10A increases.

  On the other hand, as shown on the left side of FIG. 5, the silent chain 200 is bent, and the relative bending angle between the outer guide link 30 and the meshing link 10A connected by the same connecting pin 20 is equal to or larger than a predetermined angle. In the portion, the tip of the engagement piece 12 in the engagement link 10A and the projection 33 in the outer guide link 30 do not overlap, and the engagement between the projection 33 and the engagement piece 12 of the engagement link 10A is released. .

  As a result, the rotational resistance between the meshing link 10A and the outer guide link 30 decreases, and the pressing force acting on each meshing link 10A decreases, and each meshing link 10A that has increased due to this pressing force. The rotation resistance between them also decreases.

According to the second embodiment described above, the following effects can be obtained.
(1) The outer guide link as an engaging portion that engages when the outer guide link 30 as the link member and the meshing link 10A have a bending angle less than a predetermined angle and the silent chain 200 is substantially linear. The convex part 33 is formed in the position facing this so that it may protrude toward the front-end | tip part of the meshing piece 12 in the meshing link 10A which adjoins 30. Accordingly, when the silent chain 200 starts to wind around the sprocket 40 while the convex portion 33 is engaged with the tip end portion of the engagement piece 12 in the inter-axis region to increase the rotational resistance between the outer guide link 30 and the engagement link 10A. By releasing this engagement, the rotational resistance can be reduced, and the effects equivalent to (1) to (3) in the first embodiment can be obtained.

The second embodiment can also be carried out in the following forms that are appropriately modified.
In the second embodiment, the outer guide link 30 has outer portions provided on both side surfaces of the silent chain 200 in the configuration in which the protrusions 33 are formed on the outer guide link 30 as shown in FIGS. The structure which provided the convex part 33 in both the guide links 30 was shown. On the other hand, the structure which provides the convex part 33 only in one outer guide link 30 is also employable.

  In the second embodiment, the outer guide type silent chain 200 in which the outer guide link 30 is disposed on the outer portion of the silent chain 200 is illustrated. On the other hand, as shown in FIG. 7, the guide groove 41 is formed in the sprocket 40 and the inner guide type is provided with an inner guide link 50 interposed between the meshing links 10 </ b> A instead of the outer guide link 30. The present invention can also be applied to the silent chain. Specifically, in such an inner guide type silent chain, by providing an engagement portion that engages with the tip end portion of the engagement piece 12 of the engagement link 10A on the side surface of the inner guide link 50, The same effect as the embodiment can be obtained.

  In addition, even in a silent chain including a guide link as described above, a configuration in which an engagement portion is provided on the meshing link as in the first embodiment without providing an engagement portion on the guide link, or a guide It is also possible to employ a configuration in which engaging portions are provided in both the link and the meshing link.

The first and second embodiments can be implemented in the following forms in which the above-described modified examples are appropriately changed.
-The arrangement | positioning aspect of an engaging part can be changed suitably. For example, in the first and second embodiments, the configuration in which the engaging portion that protrudes from the side surface of the link member positioned outside the silent chain toward the link member positioned inside is shown. The structure which provides the engaging part which protrudes toward the adjacent link member from the side surface of the link member located in can also be employ | adopted. Moreover, the structure which provides an engaging part in both the adjacent link members so that engaging parts may mutually oppose can also be employ | adopted.

-The number of engaging parts can also be changed suitably, such as providing an engaging part in all the link members.
In the first and second embodiments, the link member has the engagement piece 12 protruding toward the sprocket 40, and the silent chain that engages with the sprocket via the engagement piece 12 is exemplified. It is not limited to such a silent chain. For example, the present invention can be applied to a roller chain in which a link member is connected by a connecting pin and meshed with a sprocket via a roller externally fitted to the connecting pin. When the present invention is applied to a roller chain, for example, as shown in FIG. 8, an engagement portion 212 having a convex portion 213 is provided on the outer peripheral portion of the outer link 210B, and this engagement is provided on the outer peripheral portion of the inner link 210A. A configuration in which an engaged portion 214 that engages with the convex portion 213 of the joint portion 212 is provided can be employed. If such a configuration is adopted, when the bending angle of the link member is less than a predetermined angle, the convex portion 213 of the engaging portion 212 and the engaged portion are like the portion Y surrounded by a two-dot chain line in FIG. 214 is engaged, and the rotational resistance between the inner link 210A and the outer link 210B increases. On the other hand, when the bending angle is equal to or larger than the predetermined angle, the engagement between the convex portion 213 of the engaging portion 212 and the engaged portion 214 is released as in the portion X, and the inner link 210A and the outer link 210B are disengaged. The rotational resistance is reduced.

The top view of the silent chain concerning 1st Embodiment of this invention. (A), (b) is a perspective view of the meshing link which comprises the silent chain concerning the embodiment. The front view of the silent chain concerning the embodiment. (A) is a front view of the meshing link as a modified example of the first embodiment, and (b) is a cross-sectional view of the meshing link. The front view of the silent chain concerning 2nd Embodiment of this invention. (A), (b) is sectional drawing of the silent chain concerning the embodiment. Sectional drawing of the silent chain concerning the modification of 2nd Embodiment. The front view of the roller chain concerning the example of a change of this invention. The front view of the silent chain in which the spring member was interposed. A top view of the silent chain.

Explanation of symbols

10A, 10B ... meshing link, 11 ... insertion hole, 12 ... meshing piece, 13 ... engagement part, 20 ... coupling pin, 30 ... outer guide link, 33 ... convex part, 40 ... sprocket, 41 ... guide groove, 50 ... Inner guide link, 100: Silent chain, 110: Engagement link, 111: Insertion hole, 112 ... Engagement piece, 113 ... Projection, 200 ... Roller chain, 210A ... Inner link, 210B ... Outer link, 212 ... Engagement part, 213 ... convex part, 214 ... engaged part, 220 ... connecting pin, 230 ... roller.

Claims (7)

A plurality of link members having a pair of insertion holes and a plurality of connection pins respectively inserted into the insertion holes, and each link member is rotatably connected to each other by the connection pins. In addition, in the driving force transmission chain that is wound around a plurality of sprockets and transmits the driving force between the sprockets,
When the relative bending angle of the link member relative to another link member rotatably connected by the same connecting pin is less than a predetermined angle, the link member is engaged with the other link member. A driving force transmission chain characterized in that an engagement portion is provided that increases the frictional force acting between them and releases the engagement when the relative bending angle is equal to or greater than a predetermined angle. . The link member is rotatably connected by the connecting pin in a state of being alternately stacked, and has a meshing piece that can mesh with the sprocket and has a shape whose tooth width is narrower toward the tip side,
The chain for driving force transmission according to claim 1, wherein the engaging portion is located at a distal end portion of the engagement piece and protrudes from the engagement piece toward another engagement piece adjacent thereto. In the driving force transmission chain according to claim 2,
The engagement portion has a shape in which a tip end portion of the engagement piece is bent toward a tip end portion of the engagement piece adjacent to the engagement piece. The link member is rotatably connected by the connecting pin in a state of being alternately stacked, and meshed with the sprocket, and a meshing link having a meshing piece whose tooth width is narrower toward the tip side, A guide link that is rotatably connected by the connecting pin together with the meshing link and engages the sprocket to suppress a shift between the sprocket and the meshing link;
2. The drive according to claim 1, wherein the engaging portion is positioned so as to face the tip end portion of the meshing piece in the guide link and protrudes from the guide link toward the tip end portion of the meshing piece. Force transmission chain. In the driving force transmission chain according to claim 2 or 4,
The driving force transmitting chain, wherein the engaging portion is a convex portion formed so as to protrude toward a tip end portion of the meshing piece in the adjacent meshing link. In the driving force transmission chain according to claim 5,
The driving force transmitting chain, wherein the convex portion has a surface inclined so that a frictional force acting between the adjacent meshing links increases as the bending angle decreases. In the driving force transmission chain according to claim 6,
The driving force transmitting chain, wherein the convex portion is formed of a hemispherical protrusion.

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