chain

Abstract

To provide a chain that is easy to assemble, can achieve long service life and miniaturization, and can increase tolerance for misalignment.SOLUTION: A chain is configured such that a plurality of outer links 110 comprising a pair of outer plates 111 and a pin 115 and a plurality of inner links 120 comprising a pair of inner plates 121 and a bushing 125 are alternately connected in a bendable manner in a longitudinal direction of the chain by rotatably inserting the pin 115 into the bushing 125. The chain comprises a position regulation part that is located between the pair of inner plates 121 and regulates the movement of each of the pair of inner plates 121 inward in a chain width direction. The bushing 125 is rotatably inserted into a bushing hole 122 of each of the pair of inner plates 121.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] The present invention relates to a chain consisting of a plurality of inner links with bushings and a plurality of outer links with pins, which are connected in an alternating, bendable manner along the chain longitudinal direction by rotatably inserting the pins into the bushings. [Background technology]

[0002] 2. Description of the Related Art Chains used in chain transmission mechanisms are known to use hollow cylindrical bushings. One type of such chain, as shown in Figures 5A and 5B, comprises a plurality of outer links 210 formed by connecting a pair of left and right outer plates 211 by pressing both ends of a pair of front and rear pins 215 into pin holes 212 of the outer plates 211, and a plurality of inner links 220 formed by connecting a pair of left and right inner plates 221 by pressing both ends of a pair of front and rear cylindrical bushings 225 into bush holes 222 of the inner plates 221. The outer links 210 and the inner links 220 are connected to each other so that they can bend alternately in the longitudinal direction of the chain, by having the pins 215 rotatably inserted into the bushings 225. In addition, rollers 230 are rotatably fitted onto the bushings 225, so that when the chain 200 is wound around a sprocket, the rollers 230 come into contact with the teeth of the sprocket.

[0003] In a chain 200 configured as described above, the bushing 225 is press-fitted into the bushing hole 222 of the inner plate 221 and fixed therein, so when a large force is applied to the opening edge of the bushing hole 222, the inner plate 221 is deformed and distortion occurs in the inner diameter of the bushing 225. This causes accelerated wear due to sliding between the pin 215 and the bushing 225, which can shorten the life of the chain. Furthermore, when chain 200 having such a configuration is used as, for example, a bicycle chain, the chain may be shifted between multiple sprockets arranged side by side in the width direction during gear changes, causing misalignment and bending of the chain in the width direction. In this case, the flexibility of the chain in the chain width direction depends on clearance C1 between the outer peripheral surface of pin 215 and the inner peripheral surface of bushing 225. Due to the presence of clearance C1, pin 215 and bushing 225 do not always slide under constant conditions, but rather the sliding points are constantly changing, and the pressing force at the sliding points is not constant and often increases suddenly, which also accelerates wear due to the sliding between pin 215 and bushing 225.

[0004] On the other hand, bushless chains that do not have bushes are known as chains used in chain transmission mechanisms (see, for example, Patent Documents 1 and 2). Patent Document 1 discloses a conventional bushless chain in which flanges functioning as bushings are formed at the ends of the inner plates by drawing, and the inner links and outer links are flexibly connected by relative sliding between the pin and the inner plate. Patent Document 1 also discloses a bushless chain in which so-called stepped pins are used as pins connecting the outer plates, and both ends of the stepped pins are rotatably inserted into pin holes in the inner plates, thereby flexibly connecting the inner links and outer links. Patent Document 2 also discloses such a bushless chain, which discloses that the pins used have a pair of shafts that are fixed to the pin holes in the outer plates and loosely fitted into the pin holes in the inner link plates, and a movement restricting portion that is formed inward of the pair of shafts in the pin longitudinal direction and restricts movement of the inner link plates inward in the chain width direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 5-71506 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-234881 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, in a bushless chain, there are no components that are press-fitted and fixed to the inner plates, so there is no risk of the inner plates being deformed, and in this respect, premature shortening of the chain life is avoided. However, because bushless chains are bendable due to the relative sliding of the pins and inner plates, the flexibility of the bushless chain in the width direction of the chain depends on the clearance between the outer peripheral surface of the pin and the inner peripheral surface of the pin hole in the inner plate. Therefore, just like bushing chains, bushless chains also have the problem of difficulty in obtaining sufficient alignment tolerance when used in a state where bending occurs in the width direction of the chain. Furthermore, in bushless chains that form flange portions that function as bushings, high machining precision is required in forming the flange portions in order to avoid partial contact between the flange portions and the pins and rollers, which increases the machining burden and also poses the problem of reduced fatigue strength.

[0007] The present invention was made based on the above circumstances, and aims to provide a chain that is easy to assemble, has a long life, is compact, and has a large tolerance for alignment deviation. [Means for solving the problem]

[0008] The present invention solves the above problem by providing a chain consisting of a plurality of outer links each having a pair of outer plates and a pin, and a plurality of inner links each having a pair of inner plates and a bushing, which are connected in a manner that allows them to bend alternately in the longitudinal direction of the chain by rotatably inserting the pins into the bushings, and which is provided with a position regulating section positioned between the pair of inner plates that regulates the inward movement of each of the pair of inner plates in the chain width direction, and which is configured so that the bushings are rotatably inserted into the bushing holes of each of the pair of inner plates. [Effects of the Invention]

[0009] According to the invention of claim 1, the widthwise movement of the inner plate is restricted by the position restricting portion, even if the bushing is not press-fitted into the inner plate to fix it, so deformation of the inner plate does not occur when assembling the chain, and it is possible to avoid a decrease in strength due to internal strain and also to eliminate the need to add a structure to improve strength, reducing waste of material and enabling miniaturization.In addition, since the process of press-fitting the bushing into the inner plate is not required, manufacturing is easier. Furthermore, because the bushings are rotatably inserted into the bushing holes of the inner plates, the inner shape of the bushings does not change when the chain is assembled, stabilizing the inner shape of the bushings and reducing wear caused by partial contact between the pins and bushings. Moreover, because the pins are rotatably inserted into the bushings and the bushings are rotatably inserted into the bushing holes of the inner plates, the sliding points are dispersed, reducing wear. Thus, according to the invention of claim 1, the strength and wear resistance of the chain are improved, thereby improving the durability of the chain and extending its lifespan. Furthermore, even when used in a state where bending occurs in the chain width direction, the clearance between the pin and bushing and the clearance between the bushing and inner plate improves the chain's flexibility in the chain width direction, so by adjusting these clearances it is possible to increase the alignment tolerance and by combining each clearance it is possible to adjust the wear resistance.

[0010] According to the invention of claim 2, by configuring the position regulating part with a roller, it is possible to reduce manufacturing costs and workload by simply adjusting the dimensions of each component without making any major structural changes to the chain used in general chain transmission mechanisms.

[0011] According to the invention of claim 3, the position control portion is formed integrally with the bushing, eliminating the need to use components to maintain the appropriate position of the inner plate, thereby reducing the number of parts and the manufacturing man-hours. According to the invention of claim 4, the bushing can be given the function of restricting the position of the inner plate without making the bushing shape complicated, and can be easily manufactured.

[0012] According to the invention of claim 5, the precision of the inner surfaces of the first bushing and the second bushing is increased, which prevents the inner peripheral edges of both ends of the bushing from contacting the outer peripheral surface of the pin unevenly, thereby reliably suppressing wear caused by partial contact between the pin and the bushing.

[0013] According to the invention of claim 6, by configuring the position regulating part with a roller, it is possible to reduce manufacturing costs and workload by simply adjusting the dimensions of each component without making any major structural changes to the chain used in general chain transmission mechanisms.

[0014] According to the invention of claim 7, the position control portion is formed integrally with each of the first bushing and the second bushing, thereby eliminating the need to use components for maintaining the appropriate position of the inner plate, thereby reducing the number of parts and the manufacturing man-hours. According to the invention of claim 8, the bushing can be given the function of restricting the position of the inner plate without making the bushing shape complicated, and can be easily manufactured. [Brief explanation of the drawings]

[0015] [Figure 1A] 1 is a cross-sectional view schematically showing a part of an example of the configuration of a chain according to a first embodiment of the present invention. [Figure 1B] 1B is an enlarged view showing the area circled by the dashed line in FIG. 1A. FIG. [Figure 2A] FIG. 6 is a cross-sectional view that schematically shows a portion of an example of the configuration of a chain according to a second embodiment of the present invention. [Figure 2B] 2B is an enlarged view showing the area circled by the dashed line in FIG. 2A. FIG. [Figure 3A] FIG. 10 is a cross-sectional view that schematically shows a portion of an example of the configuration of a chain according to a third embodiment of the present invention. [Figure 3B] 3B is an enlarged view showing the area circled by the dashed line in FIG. 3A. FIG. [Figure 4A] FIG. 10 is a cross-sectional view that schematically shows a portion of an example of the configuration of a chain according to a fourth embodiment of the present invention. [Figure 4B] 4B is an enlarged view showing the area circled by the dashed line in FIG. 4A. FIG. [Figure 5A] FIG. 1 is a cross-sectional view schematically showing a part of an example of the configuration of a conventional chain. [Figure 5B] FIG. 5B is an enlarged view showing the area circled by the dashed line in FIG. 5A. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a chain according to an embodiment of the present invention will be described with reference to the drawings.

[0017] First Embodiment FIG. 1A is a cross-sectional view schematically showing a part of an example of the configuration of a chain according to a first embodiment of the present invention. The chain 100a of this embodiment is composed of a plurality of outer links 110 each having a pair of outer plates 111 and a pin 115, and a plurality of inner links 120 each having a pair of inner plates 121 and a bushing 125, which are connected in an alternating, bendable manner in the longitudinal direction of the chain by rotatably inserting the pins 115 into the bushings 125.

[0018] The outer link 110 is formed by connecting a pair of left and right outer plates 111 by press-fitting both ends of a pair of front and rear pins 115 into pin holes 112 of the outer plates 111. The outer plates 111 have a generally flat shape. The pins 115 are cylindrical with a constant outer diameter in the axial direction.

[0019] The inner link 120 is formed by inserting both ends of a pair of front and rear bushings 125 into bushing holes 122 of a pair of left and right inner plates 121 so as to be rotatable. The bushing 125 is cylindrical with a constant outer and inner diameter in the chain width direction, and is configured so that a predetermined clearance C1 is formed between the inner surface of the bushing 125 and the outer surface of the pin 115, as shown in FIG. 1B. The inner plate 121 has a generally flat shape. The bushing hole 122 is formed so as to have a predetermined clearance C2 between it and the outer peripheral surface of the bushing 125.

[0020] The chain 100a according to this embodiment includes a position restricting portion that is positioned between a pair of inner plates 121 and restricts the movement of each of the pair of inner plates 121 inward in the chain width direction. The position restriction portion is constituted by a roller 130 rotatably fitted onto the bushing 125. By constructing the position restriction portion with the roller 130, it is only necessary to adjust the dimensions of each component without requiring any major structural changes from chains used in general chain transmission mechanisms, making it possible to reduce manufacturing costs and workloads.

[0021] As described above, the chain 100a according to the first embodiment includes position restricting portions that restrict inward movement of each of the pair of inner plates 121 in the width direction of the chain. Therefore, the position restricting portions restrict movement of the inner plates 121 in the width direction, even without press-fitting and fixing the bushings 125 into the inner plates 121. Furthermore, by adopting a configuration in which the bushings 125 are rotatably inserted into the bushing holes 122 of each of the pair of inner plates 121, deformation of the inner plates 121 does not occur during chain assembly, and a decrease in strength due to internal strain can be avoided. This eliminates the need for additional structures to improve chain strength, reducing material waste and enabling miniaturization. Furthermore, because the process of press-fitting the bushings 125 into the inner plates 121 is unnecessary, manufacturing is easier.

[0022] Furthermore, because the bushing 125 is rotatably inserted into the bushing hole 122 of the inner plate 121, the inner shape of the bushing 125 does not change when the chain is assembled, and the inner shape of the bushing 125 is stabilized. This makes it possible to prevent wear caused by partial contact between the pin 115 and the bushing 125. Moreover, because the pin 115 is rotatably inserted into the bushing 125 and the bushing 125 is rotatably inserted into the bushing hole 122 of the inner plate 121, the sliding points are dispersed, which also makes it possible to prevent wear.

[0023] In this way, according to the chain 100a of the first embodiment, the strength and wear resistance of the chain are improved, which improves the durability of the chain 100a and enables it to have a longer lifespan.

[0024] Furthermore, by configuring the position regulating section with roller 130, it is possible to reduce manufacturing costs and workload, since it is only necessary to adjust the dimensions of each component without making any major structural changes to the chain used in general chain transmission mechanisms.

[0025] Furthermore, even when the chain is used in a state where bending occurs in the width direction of the chain, the clearance C1 between the pin 115 and the bushing 125 and the clearance C2 between the bushing 125 and the inner plate 121 improves the flexibility of the chain in the width direction, so that by adjusting these clearances C1 and C2, it is possible to increase the alignment tolerance and improve wear resistance.

[0026] The present invention has been described above using the example of a chain in which the position regulating portion is constituted by a roller, but in the chain of the present invention, the bushing itself may be configured to have the position regulating function of the inner plate.

[0027] Second Embodiment FIG. 2A is a cross-sectional view that schematically shows a part of an example of the configuration of a chain according to a second embodiment of the present invention. The chain 100b according to this embodiment is configured such that the position restriction portion is formed integrally with the bushing 125. The basic structure of this chain 100b is the same as that of the chain 100a according to the first embodiment, and the same components are denoted by the same reference numerals for convenience, and the description thereof will be omitted.

[0028] The bushing 125 used in the chain 100b of this embodiment has an expanded diameter portion 126 positioned between a pair of inner plates 121 and having an outer diameter larger than the hole diameter of the bushing hole 122 of the inner plate 121, and a pair of shaft portions 127 rotatably inserted into the bushing hole 122 of the inner plate 121 and extending in the chain width direction continuous with each end of the expanded diameter portion 126, and the expanded diameter portion 126 forms a position restricting portion that restricts the movement of the inner plate 121 inward in the chain width direction.

[0029] The inner peripheral surface of bushing 125 has a shape that follows the peripheral surface of a cylinder, i.e., the inner diameter has a constant shape in the chain width direction, and is configured so that a predetermined size of clearance C1 is formed between the inner peripheral surface of bushing 125 and the outer peripheral surface of pin 115, as shown in Figure 2B. The shaft portion 127 of the bushing 125 is formed so that a predetermined clearance C2 is formed between its outer peripheral surface and the inner peripheral surface of the bushing hole 122 of the inner plate 121.

[0030] In the chain 100b according to the second embodiment, even if the shaft portion 127 of the bushing 125 is not press-fitted into the inner plate 121 to fix it, the expanded diameter portion 126 of the bushing 125 restricts movement of the inner plate 121 in the width direction. Therefore, the chain 100b according to the second embodiment, like the chain 100a according to the first embodiment, is easy to assemble, has a long life, and is compact. It also has a larger tolerance for misalignment and is more resistant to wear.

[0031] Furthermore, by forming the position restricting portion integrally with the bushing 125, it is not necessary to use a component for maintaining the appropriate position of the inner plate 121, which makes it possible to reduce the number of parts and the number of manufacturing steps. Moreover, by forming the enlarged diameter portion 126 having an outer diameter larger than the diameter of the bushing hole 122, it is possible to impart the position restricting function of the inner plate 121 to the bushing 125 without complicating the bushing shape, and manufacturing is easy.

[0032] <Third embodiment> FIG. 3A is a cross-sectional view schematically showing a part of an example of a configuration of a chain according to a third embodiment of the present invention. The chain 100c according to this embodiment has two bushings rotatably fitted onto one pin, in other words, the bushing is divided into two in the width direction of the chain. The basic structure of this chain 100c is the same as that of the chain 100a according to the first embodiment, and the same components are denoted by the same reference numerals for convenience, and their explanation will be omitted.

[0033] To specifically describe the configuration of the chain 100c according to this embodiment, the inner link 120 in this chain 100c includes a first bush 125a and a second bush 125b that are rotatably fitted around a common pin 115 and aligned in the chain width direction. The outer ends of the first bush 125a and the second bush 125b are rotatably inserted into bushing holes 122 in one of a pair of inner plates 121.

[0034] The inner surface of the first bushing 125a has a shape that follows the circumferential surface of a cylinder, i.e., the inner diameter has a constant shape in the chain width direction, and is configured so that a predetermined size of clearance C1 is formed between the inner surface of the first bushing 125a and the outer surface of the pin 115, as shown in Figure 3B. The first bushing 125a is formed so that a predetermined clearance C2 is formed between its outer peripheral surface and the inner peripheral surface of the bushing hole 122 of the inner plate 121. The second bushing 125b is similar to the first bushing 125a, and is formed so that there is a predetermined size of clearance C1 between the inner surface of the second bushing 125b and the outer surface of the pin 115, and also a predetermined size of clearance C2 between the outer surface of the second bushing 125b and the inner surface of the bushing hole 122 of the inner plate 121.

[0035] Like the chain 100a according to the first embodiment, the chain 100c according to the third embodiment is easy to assemble, has a long life, and is compact. It also has a larger tolerance for misalignment and is more resistant to wear.

[0036] Furthermore, by dividing the bushing into two in the chain width direction, the precision of the inner surfaces of the first bushing 125a and the second bushing 125b is increased, making it possible to prevent the inner peripheral edges at both ends of the bushing from contacting only the outer peripheral surface of the pin 115. This makes it possible to reliably prevent wear caused by partial contact between the pin 115 and the first bushing 125a and the second bushing 125b.

[0037] Furthermore, by configuring the position control section with roller 130, it is possible to reduce manufacturing costs and workload by simply adjusting the dimensions of each component without making any major structural changes to the chain used in general chain transmission mechanisms.

[0038] <Fourth embodiment> FIG. 4A is a cross-sectional view that schematically shows a part of an example of the configuration of a chain according to a fourth embodiment of the present invention. The chain 100d according to this embodiment has two bushings rotatably fitted onto one pin, and a position restricting portion is formed integrally with each of the two bushings. The basic structure of this chain 100d is the same as that of the chain 100a according to the first embodiment, and the same components are denoted by the same reference numerals for convenience, and the description thereof will be omitted.

[0039] To specifically describe the configuration of the chain 100d according to this embodiment, the inner link 120 in this chain 100d includes a first bush 125a and a second bush 125b that are rotatably fitted around a common pin 115 and aligned in the chain width direction. The outer ends of the first bush 125a and the second bush 125b are rotatably inserted into bushing holes 122 in one of a pair of inner plates 121.

[0040] Both the first bushing 125a and the second bushing 125b have a shaft portion 127 that is rotatably inserted into the bushing hole 122 of the inner plate 121 and extends in the chain width direction, and an expanded diameter portion 126 that is formed at the inner end of the shaft portion 127 so as to extend radially outward around the entire circumferential direction and has an outer diameter larger than the hole diameter of the bushing hole 122 of the inner plate 121, and the expanded diameter portion 126 forms a position control portion that controls the movement of the inner plate 121 inward in the chain width direction.

[0041] The inner surface of the first bushing 125a has a shape that follows the circumferential surface of a cylinder, i.e., the inner diameter has a constant shape in the chain width direction, and is configured so that a predetermined size of clearance C1 is formed between the inner surface of the first bushing 125a and the outer surface of the pin 115, as shown in Figure 4B. The first bushing 125a is formed so that a predetermined clearance C2 is provided between the outer peripheral surface of the shaft portion 127 and the inner peripheral surface of the bushing hole 122 of the inner plate 121. The second bushing 125b is similar to the first bushing 125a, and is formed so that there is a predetermined size of clearance C1 between the inner surface of the second bushing 125b and the outer surface of the pin 115, and also a predetermined size of clearance C2 between the outer surface of the shaft portion 127 of the second bushing 125b and the inner surface of the bushing hole 122 of the inner plate 121.

[0042] Like the chain 100a according to the first embodiment, the chain 100d according to the fourth embodiment is easy to assemble, has a long life, and is compact. It also has a larger tolerance for misalignment and is more resistant to wear.

[0043] Furthermore, by dividing the bushing into two in the chain width direction, the precision of the inner surfaces of the first bushing 125a and the second bushing 125b is increased, making it possible to prevent the inner peripheral edges at both ends of the bushing from contacting unevenly with the outer peripheral surface of the pin 115. This makes it possible to reliably prevent wear caused by partial contact between the pin 115 and the first bushing 125a and the second bushing 125b.

[0044] Furthermore, by forming the position restricting portion integrally with each of the first bushing 125a and the second bushing 125b, it is not necessary to use a component for maintaining the appropriate position of the inner plate 121, which makes it possible to reduce the number of parts and the number of manufacturing steps. Moreover, by forming the enlarged diameter portion 126 having an outer diameter larger than the diameter of the bushing hole 122, it is possible to impart the position restricting function of the inner plate 121 to the first bushing 125a and the second bushing 125b without complicating the bushing shape, and manufacturing is easy.

[0045] As described above, even when the chains 100a, 100b, 100c, and 100d according to the first to fourth embodiments are used in a state in which bending occurs in the chain width direction, the clearance C1 between the pin 115 and the bushing 125 (or the clearance C1 between the pin 115 and the first bushing 125a and the second bushing 125b) and the clearance C2 between the bushing 125 and the inner plate 121 (or the clearance C2 between the shank 127 of the first bushing 125a and the shank 127 of the second bushing 125b and the inner plate 121) improves flexibility in the chain width direction, so that adjustment of the clearances C1 and C2 makes it possible to increase alignment tolerance and improve wear resistance. Therefore, the chain according to the present invention may be used in any specific application, but is useful, for example, as a bicycle chain.

[0046] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the present invention as set forth in the claims. For example, the specific form of the chain may be any type in which a plurality of link plates are connected in a bendable manner by connecting pins, and may be, for example, a silent chain. [Explanation of symbols]

[0047] 100a chain 100b chain 100c chain 100d chain 200 ··· Chain 110, 210 ··· External link 111, 211 Outer plate 112, 212 Pin holes 115, 215 ··· Pin 120, 220 ··· Internal link 121, 221 Inner plate 122, 222 ··· Bush hole 125, 225 bushing 125a 1st bush 125b Second bush 126 ··· Expanded diameter part 127 Shaft 130, 230 ··· Laura

Claims

1. A chain comprising a plurality of outer links each having a pair of outer plates and a pin, and a plurality of inner links each having a pair of inner plates and a bushing, the pins being rotatably inserted into the bushings, and the outer links being alternately connected in a bendable manner in the longitudinal direction of the chain, a position restricting portion positioned between the pair of inner plates and restricting inward movement of each of the pair of inner plates in the chain width direction; The chain is characterized in that the bushings are rotatably inserted into the bushing holes of the pair of inner plates.

2. 2. The chain according to claim 1, wherein the position restricting portion is formed by a roller rotatably fitted onto the bushing.

3. 2. The chain according to claim 1, wherein the position restricting portion is formed integrally with the bushing.

4. 4. The chain according to claim 3, wherein the bushing has an enlarged diameter portion having an outer diameter larger than the diameter of the bushing hole, and a shaft portion rotatably inserted into the bushing hole and extending in the chain width direction continuous with each end of the enlarged diameter portion, and the enlarged diameter portion constitutes the position regulating portion.

5. The inner link includes a first bushing and a second bushing that are rotatably fitted around a common pin, 2. The chain according to claim 1, wherein the first bushing and the second bushing are rotatably inserted into a bushing hole of one of the pair of inner plates.

6. The chain according to claim 5, characterized in that the position regulating portion is constituted by a roller common to the first bush and the second bush that is rotatably inserted onto the first bush and the second bush that are aligned in the chain width direction.

7. 6. The chain according to claim 5, wherein the position restricting portion is formed integrally with each of the first bushing and the second bushing.

8. each of the first bushing and the second bushing has a shaft portion inserted into a bushing hole of the inner plate, and an enlarged diameter portion formed at an end of the shaft portion on an inner side in the chain width direction, the enlarged diameter portion having an outer diameter larger than a diameter of the bushing hole; 8. The chain according to claim 7, wherein the position restricting portion is formed by the enlarged diameter portion of the first bushing and the enlarged diameter portion of the second bushing.

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