JP2008044528A - Tension adjusting device and belt driving type bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress wear of an outer peripheral surface of a belt, and to suppress the disappearance of printed letters, when a regulating member is pressed against the outer peripheral surface of the belt to add tension to the belt. <P>SOLUTION: A crank 14 is coupled to both ends of the rotating shaft 12 of the driving pulley 18, and the belt 24 is wound around the driving pulley 18 and a driven pulley 20. A supporting member 30 equipped with a stretching side arm 30A and a loosening side arm 30B is rockably provided coaxially with the rotating shaft 12. A stretching side idler 32 contacting the outer peripheral surface of the belt 24 is provided on the stretching side arm 30A, and a loosening side idler 34 contacting the outer peripheral surface of the belt 24 is provided on the loosening side arm 30B. The stretching side idler 32 and the loosening side idler 34 are equipped with recessed portions 62 at contacting portions with the belt 24 inside of flange portions 61 at both ends, and move in a direction orthogonal to a circumferential moving direction of the belt 24. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a belt tension adjusting device used in a belt driven bicycle and a belt driven bicycle including the tension adjusting device.

  2. Description of the Related Art Conventionally, a power transmission drive mechanism using a toothed belt wound around a pulley is known as a device for transmitting the rotation of a crank on which a bicycle pedal is supported to a rear wheel.

  As this power transmission drive mechanism, for example, as shown in FIG. 12, a drive pulley 206 and a driven pulley 210 on the rotary shaft 204 of the rear wheel are provided on the rotary shaft 204 of the crank 202, and the drive pulley 206 and the driven pulley are provided. A toothed belt 212 meshing with 210 is wound around. An extension side idler 220 and a loose side idler 222 for pressing the belt 212 from the outside to the inside are provided on the support 218 rotatably supported by the rotation shaft 216 on the chain stay 214 near the driven pulley 210. (For example, see Patent Document 1).

In this power transmission drive mechanism, when the crank 202 rotates and the tension of the extension-side belt 212 increases due to the resistance of the driven pulley 210, the extension-side belt 212 is tensioned, so that the extension-side idler 220 moves upward. . At this time, the belt 212 on the slack side is loosened, but the slack side idler 222 is integrated with the extension side idler 220 via the support 218, so that it rotates upward around the rotation shaft 216 of the support 218. Then, further tension is applied to the belt 212. As described above, the extension-side idler 220 moves according to the tension of the belt 212, so that the loose-side idler 222 can apply tension to the belt 212 according to the movement amount.
Japanese Utility Model Publication No. 62-163190

  However, in the power transmission drive mechanism described in Patent Document 1, since the extension side idler 220 and the loose side idler 222 are in contact with the outer peripheral surface of the belt 212, the outer peripheral surface of the belt 212 is easily worn. Since teeth are formed on the inner peripheral surface of the belt 212, characters such as a manufacturing number are often printed on the outer peripheral surface of the belt 212, and the characters cannot be seen due to wear of the belt 212. There's a problem.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a tension adjusting device and a belt-driven bicycle that can suppress wear on the outer peripheral surface of the belt.

  In order to solve the above-described problem, a tension adjusting device according to the first aspect of the present invention is connected to a driving pulley that is rotatably attached to a frame of a belt-driven bicycle, and both ends of a rotating shaft of the driving pulley. A crank with a pedal attached to the tip, a driven pulley provided on a support shaft of a rear wheel, an endless belt wound around the driving pulley and the driven pulley, and revolving around the rotation of the driving pulley; A regulating member that contacts the outer circumferential surface of the belt and regulates looseness of the belt, and the regulating member has a recess smaller than the width of the belt at a contact portion with the outer circumferential surface of the belt. It is characterized by.

  In the first aspect of the present invention, the drive pulley is rotatably attached to the frame of the belt-driven bicycle, the crank is connected to both ends of the rotation shaft of the drive pulley, and the pedal attached to the tip of the crank is scooped. As a result, the rotating shaft of the crank rotates. An endless belt is wound around the drive pulley and a driven pulley provided on the support shaft of the rear wheel, and the endless belt rotates around by the rotation of the drive pulley, and the driven pulley rotates around the belt. Rotates. The power is transmitted by rotating the support shaft of the rear wheel by the rotation of the driven pulley. At that time, the regulating member is in contact with the outer peripheral surface of the belt, and tension is applied to the belt to regulate the looseness of the belt.

  Since the restricting member includes a concave portion smaller than the width of the belt at the contact portion with the outer peripheral surface of the belt, the outer peripheral surface of the belt contacts an area other than the concave portion of the restricting member. Accordingly, at least a part of the outer peripheral surface of the belt does not come into contact with the regulating member, and wear of the outer peripheral surface of the belt is suppressed. For this reason, when characters, such as a serial number, are printed on the outer peripheral surface of the belt, it is possible to prevent the characters from being invisible due to wear of the belt.

  According to a second aspect of the present invention, in the tension adjusting device according to the first aspect, the regulating member contacts the loosened belt on the drive pulley side.

  In the invention according to claim 2, since the regulating member contacts the slack belt on the drive pulley side, tension can be applied to the slack side of the belt.

  According to a third aspect of the present invention, in the tension adjusting device according to the first or second aspect, a tension-side arm that is swingably provided on the frame and extends toward the tension side of the belt, and the belt A support member provided with a slack side arm extending to the slack side of the belt, wherein the regulation member is provided on the tension side arm and contacts the outer peripheral surface of the belt, and the slack side A loose side regulating member that is provided on the arm and is in contact with the outer peripheral surface of the belt.

  In the invention according to claim 3, the frame is provided with a swingable support member, and the support member includes a tension side arm extending to the belt tension side and a slack side extending to the belt slack side. And arm. A tension side regulating member provided on the tension side arm contacts the outer peripheral surface of the belt, and a slack side regulating member provided on the loose side arm contacts the outer peripheral surface of the belt. When the crank rotates and the tension on the tension side of the belt increases due to the resistance of the driven pulley, the belt is tensioned, so that the support member swings and the tension-side regulating member moves in a predetermined direction. At this time, although the slack side of the belt is loosened, the support member swings and moves in a direction in which the slack side regulating member presses the outer peripheral surface of the belt, and tension is applied to the belt.

  According to a fourth aspect of the present invention, in the tension adjusting device according to any one of the first to third aspects, the regulating member is an idler provided rotatably with respect to the support member. It is characterized by that.

  In the invention of claim 4, since the regulating member is an idler that can rotate with respect to the support member, the contact resistance with the belt is reduced by the rotation of the idler, and the efficiency by pedaling can be improved. In addition, it is possible to suppress wear at the contact portion between the belt and the idler.

  According to a fifth aspect of the present invention, in the tension adjusting device according to the fourth aspect, the idler includes the concave portion formed in a circumferential direction, and includes flange portions on both sides of the concave portion. It is characterized by being supported so as to be movable in the orthogonal direction.

  In the invention according to claim 5, the idler is provided with flange portions on both sides of the concave portion formed in the circumferential direction, and the flange portion suppresses the belt from coming off during traveling. In addition, since the idler is supported so as to be movable in a direction orthogonal to the moving direction of the belt, when the belt is displaced due to circular movement of the belt, manufacturing of components or assembly errors, the belt The idler moves in the direction of the difference. As a result, the outer peripheral surface of the belt and the idler can be stably brought into contact with each other, so that the belt can be prevented from falling off from the pulley. In addition, since the contact position between the outer peripheral surface of the belt and the idler is stabilized, wear of the outer peripheral surface of the belt is suppressed, and it is possible to suppress characters such as the serial number from being invisible.

  A belt-driven bicycle according to a sixth aspect of the invention includes the tension adjusting device according to any one of the first to fifth aspects.

  In the invention according to claim 6, since the tension adjusting device according to any one of claims 1 to 4 is provided, the outer peripheral surface of the belt is in contact with a region other than the concave portion of the regulating member. Since at least a part of the outer peripheral surface of the belt does not come into contact with the regulating member, wear of the outer peripheral surface of the belt is suppressed. For this reason, when characters, such as a serial number, are printed on the outer peripheral surface of the belt, it is possible to prevent the characters from being invisible due to wear of the belt.

  According to the present invention, wear on the outer peripheral surface of the belt can be suppressed. For this reason, when characters, such as a serial number, are printed on the outer peripheral surface of the belt, it is possible to prevent the characters from being invisible due to wear of the belt.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a tension adjusting device 10 used in a belt-driven bicycle 2 according to the first embodiment of the present invention. 2 and 3 are perspective views showing the main part of the tension adjusting device 10. FIG. FIG. 5 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIG. 1, in this tension adjusting device 10, a rotation shaft 12 is provided on a hanger pipe 13 (not shown) at the lower end of the seat pipe 4 of the belt-driven bicycle 2. A crank 14 extending in the opposite direction is connected. A pedal 16 is rotatably supported at the tip of the crank 14. As shown in FIGS. 2 and 3, an elliptical driving pulley 18 that rotates integrally with the rotary shaft 12 is attached between the left and right cranks 14. The rotating shaft 12 is supported by one end of the chain stay 6 of the belt-driven bicycle 2, and a circular driven pulley 20 is provided at the other end of the chain stay 6. The driven pulley 20 rotates integrally with a rotating shaft 22 of a rear wheel (not shown).

  An endless belt 24 is wound around the driving pulley 18 and the driven pulley 20. A plurality of teeth 26 (see FIG. 6) are formed on the inner peripheral surface of the belt 24, and these teeth 26 are meshed with a plurality of teeth 28 formed on the peripheral surfaces of the drive pulley 18 and the driven pulley 20. ing. When the crank 14 is rotated in the direction of arrow A (clockwise), the drive pulley 18 integrated with the rotary shaft 12 rotates in the direction of arrow B (clockwise), and the belt 24 rotates in the direction of arrow C. . The driven pulley 20 is rotated by the circumferential movement of the belt 24, and power is transmitted to the rear wheels (not shown).

  As shown in FIGS. 5A and 5B, a crank 14 is connected to both ends of the rotating shaft 12, and the rotating shaft 12 is fixedly supported at the lower end of the seat pipe 4 of the belt-driven bicycle 2. The hanger pipe 13 is rotatably supported via a bearing 40. A support member 30 is supported on the hanger pipe 13 by a hanger one 41 and a ring nut 42 so as to be swingable. The swing center of the support member 30 is provided coaxially with the rotary shaft 12, and the swing center of the support member 30 and the rotation center of the drive pulley 18 are concentric. Thereby, the support structure of the support member 30 becomes simple, and cost can be reduced.

  As shown in FIG. 1, the support member 30 is substantially V-shaped and includes a tension side arm 30 </ b> A that extends to the tension side of the belt 24 and a slack side arm 30 </ b> B that extends to the slack side of the belt 24. ing. The support member 30 is supported by a substantially V-shaped protrusion so as to be swingable. A substantially columnar tension side idler 32 that is in contact with the outer peripheral surface of the belt 24 is rotatably supported at the distal end portion of the tension side arm 30A. A substantially columnar slack side idler 34 that is in contact with the outer peripheral surface of the belt 24 is rotatably supported at the tip of the slack side arm 30B. That is, when the crank 14 is rotated in the direction of arrow A, the torque is increased by the rotation of the drive pulley 18 and the upper side of the belt 24 is stretched, but the drive pulley 18 on the upper side (the tension side) of the belt 24 is closely opposed. The tension side idler 32 is in contact with the position. Further, although the upper side of the belt 24 is stretched, the lower side of the belt 24 is loosened, but the loose side idler 34 is in contact with the drive pulley 18 on the lower side (slack side) of the belt 24 in the vicinity.

  Further, the distance between the swing center of the support member 30 and the loose side idler 34 is set to be larger than the distance between the swing center of the support member 30 and the tension side idler 32.

  As shown in FIG. 7, a male screw 52 for supporting the tension side idler 32 is screwed to the female thread 31 formed at the tip of the tension side arm 30 </ b> A of the support member 30. Dust covers 54 and 56 having a substantially U-shaped cross section are pushed outwardly on the cylindrical portion 52A of the male screw 52 so that the U-shaped portions face each other. An annular collar 58 is sandwiched inside the dust cover 54. The opening portion 32 </ b> A of the tension side idler 32 is extrapolated so as to contact the collar 58. A nut 50 is screwed into the threaded portion from which the male screw 52 has come out to prevent loosening.

  The tension side idler 32 rotates with respect to the collar 58, but dust or the like is generated in the opening portion 32 </ b> A of the tension side idler 32 that serves as a rotational contact portion between the tension side idler 32 and the collar 58 by the substantially U-shaped dust covers 54 and 56. Intrusion is effectively prevented and durability is improved.

  Further, flange portions 61 projecting in the radial direction are formed at both ends of the tension side idler 32, and the belt 24 is held so as not to come off. On the outer peripheral surface between the flange portions 61 of the tension side idler 32, a concave portion 62 smaller than the width of the belt 24 is formed in the circumferential direction. The tension side idler 32 is in contact with the outer peripheral surface of the belt 24 on the horizontal surfaces on both sides of the recess 62. The loose side idler 34 has the same configuration as the tension side idler 32.

  Such a tension side idler 32 (slack side idler 34) has a gap formed between the protrusions 32B on both sides and the dust covers 54 and 56, and the left and right sides with the opening 32A in contact with the collar 58. Move in the direction of the arrow. That is, the tension side idler 32 moves in a direction orthogonal to the moving direction of the belt 24.

  As shown in FIGS. 1 and 8, the drive pulley 18 has an elliptical shape, and includes a long diameter portion 18A and a short diameter portion 18B in a direction orthogonal to the long diameter portion 18A. As shown in FIG. 8, when the crank 14 rotates clockwise by about 70 ° with respect to the vertical direction, the long diameter portion 18 </ b> A of the drive pulley 18 is in the axial direction between the drive pulley 18 and the driven pulley 20. The drive pulley 18 is coupled to the rotary shaft 12 so as to be at right angles.

  As shown in FIG. 9, in the belt-driven bicycle 2, the torque peak 70 occurs twice when the left and right pedals 16 are stepped down during one rotation of the crank 14. The peak value fluctuates greatly depending on traveling conditions such as a flat ground or a slope, and the peak value becomes particularly large when the slope or the slope starts. In general, when the crank 14 rotates clockwise by about 70 ° with respect to the vertical direction, the torque acting on the rotating shaft 12 becomes maximum (peak 70 in FIG. 9). The long diameter portion 18 </ b> A of the drive pulley 18 is perpendicular to the direction between the axes of the drive pulley 18 and the driven pulley 20. Since the left and right cranks 14 are 180 ° out of phase, if the crank 14 on one side is at a position of 70 °, the crank 14 on the opposite side is also at a position 70 ° on the opposite side of the vertical direction.

  Here, the number of teeth of the drive pulley 18 is set to 50T, and the flatness of the drive pulley 18 is set to about 0.0472. Here, the flatness refers to a value represented by (ab) / a, where a is the radius of the long diameter portion 18A and b is the radius of the short diameter portion 18B.

  Next, the operation of the tension adjusting device 10 will be described.

  As shown in FIG. 8, when a rider on the belt-driven bicycle 2 steps on the pedal 16 and rotates the crank 14 in the direction of arrow A, the drive pulley 18 rotates in the direction of arrow B due to the rotation of the rotating shaft 12. . As the drive pulley 18 rotates, the belt 24 rotates in the direction of arrow C, and the driven pulley 20 rotates. As the driven pulley 20 rotates, power is transmitted to a rear wheel (not shown) provided on the rotating shaft 22 of the driven pulley 20.

  At that time, the tension side idler 32 is in contact with the outer peripheral surface of the belt 24 at a position close to the driving pulley 18 on the upper side (the tension side) of the belt 24. As a result, when the crank 14 rotates in the direction of arrow A and the tension of the tension belt 24 increases due to the resistance of the driven pulley 20, the tension belt 24 is tensioned, so that the tension idler 32 moves upward (arrow D). Direction). At this time, the belt 24 on the lower side (slack side) is loosened, but the support member 30 supporting the loose side idler 34 swings upward, and accordingly, the loose side supported by the support member 30. The idler 34 moves upward (arrow E direction). As a result, the loose side idler 34 presses the outer peripheral surface of the belt 24, and tension is applied to the loose side of the belt 24.

  When the long diameter portion 18A of the elliptical drive pulley 18 is perpendicular to the direction between the axes of the drive pulley 18 and the driven pulley 20, the short diameter portion 18B corresponds to the direction between the axes of the drive pulley 18 and the driven pulley 20. As compared with the case of the right angle, a path difference is generated and a large pretension is applied to the belt 24. When the crank 14 is at a position of about 70 ° in the direction of arrow A with respect to the vertical direction, the drive pulley 18 has a long diameter portion 18A perpendicular to the direction between the axes of the drive pulley 18 and the driven pulley 20. It is supported by. For this reason, when the torque acting on the rotating shaft 12 reaches a maximum (peak 70 in FIG. 9), such as during a hill or when starting out, a pretension is applied to the belt 24, so that the responsiveness is good.

  Further, by adding the tension side idler 32 (slack side idler 34) to the drive pulley 18 side, even if the distance between the shafts of the drive pulley 18 and the driven pulley 20 is separated, only the long diameter portion 18A and the short diameter portion 18B. The path difference can be expanded more reliably than in the case of. Further, even when the maximum torque varies greatly, such as starting from a stop and going uphill from a flat ground, the necessary tension can be quickly applied. For this reason, generation | occurrence | production of the tooth skip of the belt 24 by the tension | tensile_strength of the belt 24 being insufficient can be suppressed. Here, the tooth skipping is a phenomenon in which the teeth of the belt 24 ride on the teeth of the driving pulley 18 or the driven pulley 20 and jump over when the tension is weak.

  Further, since the distance between the swing center of the support member 30 and the loose side idler 34 is larger than the distance between the swing center of the support member 30 and the tension side idler 32, the tension side idler 32 when the belt 24 is stretched is used. The loose side idler 34 moves greatly by a small movement. As a result, a large tension is quickly applied to the loose side of the belt 24.

  In such a tension adjusting device 10, the tension side idler 32 and the loose side idler 34 are provided with a recess 62 smaller than the width of the belt 24 on the outer peripheral surface, so that the belt 24 is sandwiched between the flange portions 61. The outer peripheral surface of the belt 24 contacts the horizontal surfaces on both sides of the recess 62. As a result, a part of the outer peripheral surface of the belt 24 does not contact the tension side idler 32 and the loose side idler 34, and wear of the outer peripheral surface of the belt 24 can be suppressed. For this reason, when characters, such as a manufacturing number, are printed on the outer peripheral surface of the belt 24, it can suppress that a character becomes invisible by abrasion of the belt 24. FIG.

  As shown in FIG. 7, the tension side idler 32 (slack side idler 34) moves to the left and right (in the direction of the arrow) with the opening 32 </ b> A in contact with the collar 58. In other words, the tension side idler 32 and the loose side idler 34 move in a direction orthogonal to the circumferential movement direction of the belt 24. For this reason, when a lateral displacement of the belt 24 occurs due to the circumferential movement of the belt 24, manufacturing of component parts, or assembly errors, the tension side idler 32 or the belt 24 is sandwiched between the flange portions 61. The loose side idler 34 moves in the direction of displacement of the belt 24. For this reason, the outer peripheral surface of the belt 24 and the tension side idler 32 can be contacted stably. Thereby, the contact position of the outer peripheral surface of the belt 24 and the tension side idler 32 is stabilized, and the occurrence of wear in the region facing the concave portion 62 of the outer peripheral surface of the belt 24 can be suppressed.

  Next, a tension adjusting device according to a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 10, in the tension adjusting device 80, a support member 82 is fixedly supported on the hanger pipe 13 of the rotating shaft 12. The support member 82 includes a slack side arm 82A extending to the slack side (downward side) of the belt 24, and the slack side idler 34 is rotatably supported at the tip of the slack side arm 82A. The loose side idler 34 is in contact with the outer peripheral surface of the belt 24 at a position close to and opposed to the drive pulley 18 and presses the belt 24 from the outside to the inside.

  The loose-side idler 34 has the same configuration as that of FIG. 7, a recess 62 is formed at the center of the outer peripheral surface, and flange portions 61 are provided at both ends of the outer peripheral surface. Further, the loose side idler 34 is configured to be movable in a direction perpendicular to the circumferential movement direction of the belt 24.

  In such a tension adjusting device 80, by providing the slack side idler 34, tension can be applied to the slack side of the belt 24. Further, since the loose side idler 34 is provided with a recess 62 smaller than the width of the belt 24 on the outer peripheral surface, the belt 24 is sandwiched between the flange portions 61, and the outer peripheral surface of the belt 24 is a horizontal surface on both sides of the recess 62. To touch. As a result, a part of the outer peripheral surface of the belt 24 does not contact the tension side idler 32 and the loose side idler 34, and wear of the outer peripheral surface of the belt 24 can be suppressed. For this reason, when characters, such as a manufacturing number, are printed on the outer peripheral surface of the belt 24, it can suppress that a character becomes invisible by abrasion of the belt 24. FIG.

  Further, when a lateral displacement of the belt 24 occurs due to the circumferential movement of the belt 24, manufacturing of components, or an assembly error, the loose idler 34 is connected to the belt 24 while the belt 24 is sandwiched between the flange portions 61. It moves in the direction of 24 shifts. For this reason, the outer peripheral surface of the belt 24 and the loose side idler 34 can be contacted stably. Thereby, the contact position of the outer peripheral surface of the belt 24 and the loose side idler 34 is stabilized, and the occurrence of wear in a predetermined region of the outer peripheral surface of the belt 24 can be suppressed.

  Next, a tension adjusting device according to a third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the member same as 1st and 2nd embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 11A, in the tension adjusting device 100, the support member 102 is supported on the hanger pipe 13 of the rotating shaft 12 so as to be swingable. A tension side arm 102A extending to the upper side and a slack side arm 102B extending to the slack side (lower side) of the belt 24 are provided. A tension-side regulating member 104 is fixed to the distal end portion of the tension-side arm 102A, and a slack-side regulating member 106 is fixed to the distal end portion of the slack-side arm 102B.

  As shown in FIG. 11C, the loose side regulating member 106 has a distal end portion 103 of the loose side arm 102B bent in a U-shape, and a friction member 107 for sliding with the belt 24 is fixed inside thereof. Is. A concave portion 62 is formed on the surface of the friction member 107 along the moving direction of the belt 24. As shown in FIG. 11B, the tension side regulating member 104 has the same configuration.

  In such a tension adjusting device 100, when the tension side regulating member 104 moves upward due to the swinging of the support member 102, the loose side regulating member 106 moves upward, and tension is applied to the loose side of the belt 24. . Further, a recess 62 is formed on the surface of the friction member 107, and the outer peripheral surface of the belt 24 contacts the horizontal surfaces on both sides of the recess 62. As a result, a part of the outer peripheral surface of the belt 24 does not come into contact with the friction member 107 and wear of the outer peripheral surface of the belt 24 can be suppressed. For this reason, when characters, such as a manufacturing number, are printed on the outer peripheral surface of the belt 24, it can suppress that a character becomes invisible by abrasion of the belt 24. FIG. In the configuration shown in FIG. 11, although it is predicted that the frictional resistance is increased as compared with the configuration in which the tension side idler 32 and the loose side idler 34 are provided, the number of parts is small, which is advantageous in terms of cost.

  In the first embodiment, the center of swing of the support member 30 is provided coaxially with the rotating shaft 12 of the crank 14, but the present invention is not limited to this configuration. The support member 30 may be configured to be swingably supported by a member different from the hanger pipe 13 of the rotating shaft 12.

It is a block diagram which shows the tension adjustment apparatus of the belt drive type bicycle which is 1st Embodiment of this invention. It is a perspective view which shows the principal part of the tension adjustment apparatus shown in FIG. It is the perspective view which looked at the principal part of the tension adjustment apparatus shown in FIG. 1 from the other direction. It is a block diagram which shows the tension adjustment apparatus shown in FIG. (A) is AA sectional drawing in FIG. 4, (B) is an enlarged view of the attachment part vicinity of a supporting member. It is a partial block diagram which shows the state which the tooth | gear of the drive pulley and the tooth | gear of the belt meshed | engaged. It is sectional drawing which shows a tension | tensile_strength side idler. It is a block diagram which shows the state of a crank and a drive pulley when the torque which acts on a rotating shaft becomes the maximum. It is a graph which shows the peak of the torque which generate | occur | produces twice during one rotation of a crank. It is a block diagram which shows the tension adjustment apparatus of the belt drive type bicycle which is 2nd Embodiment of this invention. It is a block diagram which shows the tension adjustment apparatus of the belt drive type bicycle which is 3rd Embodiment of this invention. It is a block diagram which shows the tension adjustment apparatus of the conventional belt drive type bicycle.

Explanation of symbols

2 Belt-driven bicycle 10 Tension adjusting device 12 Rotating shaft 13 Hanger pipe (frame)
14 Crank 16 Pedal 18 Drive pulley 20 Driven pulley 22 Rotating shaft (support shaft)
24 Belt 26 Teeth 28 Teeth 30 Support Member 30A Tension Side Arm 30B Loose Side Arm 32 Tight Side Idler 34 Loose Side Idler 61 Flange 62 Recess 80 Tension Adjuster 82 Support Member 82A Loose Side Arm 100 Tension Adjuster 102 Support Member 102A Tension Side arm 102B Loose side arm 103 Tip portion 104 Tight side regulating member 106 Loose side regulating member 107 Friction member

Claims (6)

A drive pulley rotatably mounted on a belt-driven bicycle frame;
A crank connected to both ends of the rotating shaft of the drive pulley, and a pedal attached to the tip;
A driven pulley provided on the support shaft of the rear wheel;
An endless belt wound around the drive pulley and the driven pulley and revolving around the rotation of the drive pulley;
A regulating member that contacts the outer peripheral surface of the belt and regulates looseness of the belt,
The tension regulating device according to claim 1, wherein the regulating member includes a concave portion smaller than a width of the belt at a contact portion with the outer peripheral surface of the belt.   The tension adjusting device according to claim 1, wherein the regulating member contacts the loosened belt on the drive pulley side. A support member provided on the frame so as to be swingable, and having a tension side arm extending toward a tension side of the belt and a slack side arm extending toward a slack side of the belt;
The regulation member is provided on the tension side arm and is provided with a tension side regulation member that is in contact with the outer peripheral surface of the belt, and the slack side regulation member is provided on the loose side arm and is in contact with the outer peripheral surface of the belt. The tension adjusting device according to claim 1, wherein the tension adjusting device is configured.   The tension adjusting device according to any one of claims 1 to 3, wherein the restricting member is an idler provided rotatably with respect to the support member.   5. The idler is characterized in that the concave portion is formed in a circumferential direction, flange portions are provided on both sides of the concave portion, and supported so as to be movable in a direction orthogonal to the moving direction of the belt. The tension adjusting device described in 1.   A belt-driven bicycle comprising the tension adjusting device according to any one of claims 1 to 5.

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