JP4260068B2 - Bicycle with transmission - Google Patents

Description

  The present invention relates to a bicycle including a transmission including a derailleur.

  In a bicycle transmission, for the purpose of shifting, the structure spanned between the drive sprocket and the driven sprocket is, for example, a mechanism for switching between a plurality of sprockets provided on the driven sprocket. Derailleur is used. For example, a derailleur of a bicycle transmission disclosed in Patent Document 1 is fitted with a guide member fixed in an axial direction and a rotational direction to an upper body provided on a bicycle frame, and a guide member that is rotatably and axially movable. And a lower body pivotally attached to the control lever by a first pin and rotatably supporting a transmission wheel around which the chain is wound. Further, the sliding member provided slidably inside the cylindrical guide member is provided with a pair of transverse pins that engage with the control lever through a pair of helical slots formed in the guide member. . Then, the sliding member is moved in the axial direction by operating the cable coupled to the change lever, and the control lever is rotated and moved in the axial direction with respect to the guide member. The chain is replaced with the other sprocket.

  Here, the axis of the transmission wheel is parallel to the axis of the hub, whereas the control lever pivotally attached to the lower body that rotatably supports the transmission wheel by the first pin is the same as the axis of the first pin. Therefore, it is necessary to maintain the parallel relationship between the axis of the transmission wheel and the axis of the hub. For this purpose, an auxiliary connecting rod for connecting the lower body and the upper body is provided. One end of the auxiliary connecting rod is pivotally attached to the lower body by a second pin parallel to the first pin, and the other end of the auxiliary connecting rod is attached to the upper body so as to be rotatable and slidable in the axial direction.

Japanese Patent No. 2654101 (FIGS. 1 to 6)

  In the prior art, in order to maintain the parallel relationship between the axis of the transmission wheel and the axis of the hub, an auxiliary connecting rod and a member for attaching the auxiliary connecting rod are required, and the structure of the derailleur is complicated. The number of parts increases and the cost increases.

  The present invention has been made in view of such circumstances, and the invention according to claims 1 to 7 is intended to simplify the structure of the derailleur of the bicycle transmission, and hence the transmission, and reduce the number of parts. With the goal.

The invention according to claim 1 is a bicycle including a vehicle body frame, a crankshaft, and a transmission including a derailleur. The derailleur includes a derailleur shaft, a derailleur arm supported by the derailleur shaft, and the derailleur arm. And a guide rotator wound around an endless transmission band that is exchanged between a plurality of rotator elements constituting a multistage driven rotator, and the transmission includes the body frame. , A transmission mechanism that is a mechanism that is switched to a desired transmission position by the derailleur, and an output shaft that is coaxially coupled to the driven rotating body. The case includes the derailleur and the transmission mechanism. The mechanism and the output shaft are housed, the derailleur shaft is supported, and the crankshaft has a main shaft that passes through the case. The speed change mechanism is disposed coaxially with the main shaft and is driven and connected to be driven to rotate by the crankshaft, the driven rotating body disposed above the main shaft, and the drive rotation. And the endless transmission belt spanned over the driven rotating body, the derailleur shaft being disposed directly above the output shaft or the driven rotating body, and the derailleur arm surrounding the derailleur shaft. is supported by the derailleur shaft so as to allow translational movement in the rotational center line direction of the rotational movement and the driven rotating body in a direction, the guide part of the rotating body, the endless transmission belt is a plurality of rotary element Among the bicycles, the bicycle occupies a position overlapping with the driven rotating body in a side view when wound around the rotating body element having the smallest outer diameter.

According to a second aspect of the present invention, in the bicycle according to the first aspect, the bicycle includes a pair of swing arms that are swingably supported by a pivot shaft provided on the body frame and pivotally support a rear wheel. The shaft penetrates the case and supports the case .

According to a third aspect of the present invention, in the bicycle according to the second aspect, the output shaft and the driven rotating body are disposed obliquely forward and upward with respect to the main shaft, and the endless transmission band includes the guide rotating body, Wrapped around a tension rotator of a tensioner that applies tension to the endless transmission band, the guide rotator and the tension rotator are disposed rearward of the derailleur shaft, and at a position in the vertical direction, The pivot shaft is located between the rotation center line of the driven rotating body and the center axis line of the derailleur shaft, and the pivot shaft is positioned between the main shaft and the rotation center line of the driven rotation body in the vertical direction. It is located in .

According to a fourth aspect of the present invention, in the bicycle according to any one of the first to third aspects, the body frame includes a main frame extending rearward from the head pipe and a down disposed below the main frame. A tube, and the main shaft, the output shaft, and the derailleur shaft are disposed between the main frame and the down tube .

According to a fifth aspect of the present invention, in the bicycle according to any one of the first to fourth aspects, the driving rotary body provided on the main shaft so as to be movable in a rotation center line direction of the main shaft is the guide rotary body. Is moved in the direction of the rotation center line of the main shaft through the endless transmission band .

  According to a sixth aspect of the present invention, in the bicycle according to any one of the first to fifth aspects, the case is made of metal.

  The invention according to claim 7 is the bicycle according to any one of claims 1 to 5, wherein the case is made of a synthetic resin.

According to the first aspect of the present invention, the derailleur shaft that supports the derailleur arm that rotatably supports the guide rotator is supported using the derailleur shaft that constitutes the derailleur, the derailleur arm, and a case that houses the guide rotator. Ru is. The derailleur, the speed change mechanism, and the output shaft are housed in the case, and the crankshaft has a main shaft that passes through the case. The derailleur shaft is disposed immediately above the output shaft or the multistage driven rotating body, and the derailleur arm rotates and moves in the circumferential direction on the derailleur shaft and in the direction of the rotation center line of the driven rotating body. The guide rotating body is supported by the derailleur shaft so that translational movement is possible, and the endless transmission band is wound around a rotating body element having a minimum outer diameter among the plurality of rotating body elements. It occupies a position overlapping the driven rotating body in a side view .
As a result, the derailleur shaft supporting the derailleur arm for rotatably supporting the guide rotating body is supported by the case, reduces the number of parts upon the structure of the derailleur is simplified, thus the cost is Ru are reduced.

According to a second aspect of the present invention, the pivot shaft provided on the vehicle body frame and swingably supporting the pair of swing arms penetrates the case of the transmission and supports the case .

According to a third aspect of the present invention, the guide rotator and the tension rotator are arranged rearward of the derailleur shaft, and at the position in the vertical direction, the rotation center line of the driven rotator The pivot shaft is positioned between the main shaft and the rotation center line of the driven rotating body at a position in the vertical direction .

According to the invention of claim 4, the main shaft, the output shaft, and the derailleur shaft are disposed between the main frame and the down tube .

According to the fifth aspect of the present invention, the drive rotator provided on the main shaft so as to be movable in the direction of the rotation center line of the main shaft is connected to the drive rotator via the endless transmission band when the guide rotator moves in translation. The main shaft is moved in the direction of the rotation center line .

  According to the invention described in claim 6, the case is made of metal.

  According to the seventh aspect of the present invention, the case is formed of a synthetic resin.

Embodiments of the present invention will be described below with reference to FIGS.
Referring to FIGS. 1 and 2, a bicycle B in which the transmission according to the present invention is used is a downhill bicycle, and it is timed by going down an unpaved course with a high-speed corner and a jump section on a forest road or the like. Used for competitions.

Body frame F of the bicycle B includes a head pipe 1 steerably supports a front fork 5 of the left and right pair for supporting the front wheel W _F at its lower part, the main from the head pipe 1 a pair of left and right extending rearward obliquely downward A frame 2, a down tube 3 that extends obliquely rearward and downward from the front end portions of both main frames 2, and a saddle frame 4 that extends from the center of each main frame 2 and supports a saddle 6. As shown in FIGS. 1 and 3, the down tube 3 is disposed below the main frame 2.

In this specification and claims , “upper and lower”, “front and rear” and “left and right” are based on the bicycle, and correspond to “up and down”, “front and rear” and “left and right” of the bicycle, respectively. . The side view means viewing from the left-right direction.

The pivot axis 7 of the pivot portion provided in a rear portion 2a of the main frames 2, front end of the pair of left and right swing arms 8 pivotally supporting the rear wheel W _R through the axle 9 attached to the rear end portion The portion 8a is supported to be swingable. Both swing arms 8, via a suspension 10 having a compression spring 10a and a damper 10b that is coupled to the main frames 2, it is swingable in the vertical direction about the pivot shaft 7 together with the rear wheel W _R .

  The bicycle B is equipped with the crankshaft 11 and a transmission including the transmission T and a driving force transmission mechanism. As shown in FIG. 1, the crankshaft 11 is located between the rear part 2a of the main frames 2 and the rear part 3a of the down tube 3 positioned in front of the rear part 2a. A main shaft 11a and a transmission T fixed to the rear portions 2a and 3a are disposed, and the center line of the vehicle body in the vehicle width direction of the bicycle B (corresponding to the left-right direction) when viewed from above, that is, in plan view. The driving force transmission mechanism is disposed on the right side that is one side of the vehicle body center line L1 (see FIG. 2) and the transmission T.

  Referring also to FIG. 3, the transmission T includes a pair of left and right first and second case portions 21, 22 that are coupled by bolts B <b> 1 at a large number of bolt fastening portions 21 a, 22 a formed at the peripheral edge, and will be described later. And a metal case 20 composed of a cap 25. The case 20 is fixed to the main frame 2 and the down tube 3 by a bolt B2 as a fixing means in a pair of attachment portions 20a formed at the peripheral edge.

  The crankshaft 11, which is a pedal-type crankshaft, is coupled to a main shaft 11a disposed so as to penetrate the lower part of the case 20 in the left-right direction, and to both left and right end portions of the main shaft 11a protruding to the outside of the case 20. And a pair of crank arms 11b. A pedal 12 (see FIG. 1) is rotatably attached to each crank arm 11b.

  Above the main shaft 11a of the crankshaft 11 and above the case 20, there are an output shaft 24, a derailleur shaft 61 and a pivot shaft 7 of the transmission T, and their rotation center line L4 and center axis lines L5, L2 Are arranged extending in the left-right direction so that the lines L4, L5, and L2 are parallel to the rotation center line L3 of the crankshaft 11. The crankshaft 11, the output shaft 24, the derailleur shaft 61, and the pivot shaft 7 occupy overlapping positions in the left-right direction, and intersect the vehicle body center line L1 in plan view.

The pivot shaft 7 is inserted into a through hole 2c formed in the pivot boss 2b of the rear portion 2a of each main frame 2 and a through hole 23 formed by the cylindrical portions 21b and 22b of the first and second case portions 21 and 22. It extends through the inside of a pair of cylindrical bushes 13 that are respectively held, and is fixed to the rear part 2 a of each main frame 2. Each swing arm 8 has a pivot shaft on the left and right sides of the case 20, with a front end 8 a located between the case 20 and the rear part 2 a of each main frame 2 in the left-right direction projecting outside the case 20. 7 is supported by the pivot shaft 7 so as to be swingable. The pivot shaft 7 supports the case 20 via the bush 13.

Referring to FIG. 1, the output shaft 24 and the pivot shaft 7 are disposed so as to be within the rotation locus of the crank arm 11b. Then, the output shaft 24 and the pivot shaft 7, the rotational centerline L4 of rotation of the rear wheel W _R and swinging center line L2 for both swing arms 8 (which coincides with the central axis line L2 of the pivot shaft 7.) Of the output shaft 24 It is arranged with respect to the vehicle body frame F so as to be located within the virtual swing range of the virtual plane H including the center line L6 (which coincides with the center axis of the axle 9). That is, the virtual plane H swings in the virtual swing range around the swing center line L2 corresponding to the swing range of both swing arms 8, but the rotation center line L4 of the output shaft 24 Located within the moving range.

2 and 3, the output shaft 24 housed in the case 20 has a right end portion 24a which is one end portion protruding outward from the second case portion 22, and an output driving rotation is provided on the right end portion 24a. The drive sprocket 15 as a body is coupled. Referring also to FIG. 1, the chain 16 as an output endless transmission belt of flexible between the driven sprocket 17 as the output driven rotating member drivingly connected to the rear wheel W _R and the drive sprocket 15 It is handed over. Here, the driving sprocket 15, chain 16 and driven sprocket 17 constitute the drive force transmission mechanism for driving the wheels W _R after the drive wheel. The output shaft 24 is a rotating direction of advancing the rear wheel W _R and constantly conjunction with forward direction A0 (bicycle B. Hereinafter, various axes and sprocket when the crank shaft 11 is rotated in the normal direction A0 The forward rotation direction is indicated by symbol A0.) And the reverse rotation direction is opposite to the normal rotation direction A0.

Hereinafter, the crankshaft 11 and the transmission T will be further described.
2 and 3, the transmission T includes a case 20, and a transmission mechanism M1 and a transmission switching mechanism M2 that are both housed in the case 20. A part of the crankshaft 11 is housed in the case 20 and is held by the case 20, and a shift switching mechanism M2 that is mounted on the case 20 and switches the transmission mechanism M1 to a desired shift position is provided with the transmission mechanism. Actuated to M1. The speed change mechanism M1 includes a one-way clutch 32, a slide mechanism S, a driving sprocket body 30, a driven sprocket body 40, a chain 48, and an output shaft 24, which will be described later.

A crankshaft 11 as a first rotating shaft is rotatably supported by the case 20 via a pair of left and right bearings 26 . Both bearings 26 provided at portions near both ends of the main shaft 11a are held by the case portions 21 and 22 in the case 20, respectively. A driving sprocket body 30 as a first rotating body or a driving rotating body is disposed on the main shaft 11a between the bearings 26 and coaxially with the main shaft 11a.

  The drive sprocket 31 is drivingly connected to the main shaft 11a via a one-way clutch 32 and a slide mechanism S arranged coaxially with the main shaft 11a, and is driven to rotate by the crankshaft 11. The drive sprocket 31 and the one-way clutch 32 are arranged at positions that do not overlap each other in the direction A3 of the rotation center line L3 of the crankshaft 11, as shown in FIG.

  Referring also to FIG. 4, the one-way clutch 32 is composed of a pair of ratchet pawls 32c as clutch elements, a clutch inner 32a composed of a part of the main shaft 11a, and a part of an inner cylinder 34 described later. A clutch outer 32b, and a ring spring 32d held by the clutch inner 32a. Each ratchet pawl 32c whose base portion 32c1 is swingably supported by a support portion 32d1 formed of a recess formed on the outer peripheral surface of the clutch inner 32a has a plurality of tip end portions 32c2 formed on the inner peripheral surface of the clutch outer 32b. The ring spring 32d is urged so as to be able to engage with the claw portion 32b1.

  When the clutch inner 32a rotates in the normal rotation direction A0 of the crankshaft 11 relative to the clutch outer 32b, the tip end portion 32c2 of each clutch pawl 32c is engaged with the pawl portion 32b1, whereby the clutch inner 32a And the clutch outer 32b rotate integrally, and when the clutch inner 32a rotates relative to the clutch outer 32b in the reverse rotation direction opposite to the normal rotation direction A0, the tip end portion 32c2 of each clutch claw 32c is a claw portion. The clutch inner 32a can rotate independently of the clutch outer 32b without engaging with 32b1. Therefore, the one-way clutch 32 transmits only the rotation of the crankshaft 11 in the normal rotation direction A0 to the drive sprocket 31.

  2 and 3, between the one-way clutch 32 and the drive sprocket 31, the drive sprocket 31 can be moved in the rotation center line direction A3 with respect to the main shaft 11a and the clutch outer of the one-way clutch 32 can be moved. A slide mechanism S that rotates integrally with 32b is provided. A part of the slide mechanism S constitutes a clutch outer 32b and is rotatably supported on the outer periphery of the main shaft 11a via a pair of bearings 33 coaxially with the main shaft 11a. An outer cylinder 35 disposed coaxially with the inner cylinder 34 outward in the direction, and a ball spline mechanism 36 as an engagement mechanism provided between the outer peripheral surface of the inner cylinder 34 and the inner peripheral surface of the outer cylinder 35 Prepare. A drive sprocket 31 and a chain guide 37 are coupled to and integrated with the outer cylinder 35 by a bolt B3. The drive sprocket 31, the chain guide 37, and the outer cylinder 35 rotate integrally and along the main shaft 11a. Moves integrally in the rotation center line direction A3.

  The inner cylinder 34 and the drive sprocket 31 and the outer cylinder 35 are rotated together, that is, the slide mechanism S and the drive sprocket 31 are rotated together, and the drive sprocket 31 and the outer cylinder 35 are moved relative to the inner cylinder 34 and the main shaft 11a. The ball spline mechanism 36 for enabling movement in the rotation center line direction A3 is such that the outer circumferential surface of the inner cylinder 34 and the inner circumferential surface of the outer cylinder 35 face each other in the radial direction at equal angular positions in the circumferential direction. A pair of housing grooves 36a and 36b having a semicircular cross section formed respectively, and a pair of housing grooves 36a and 36b are housed so as to roll over and engage with the inner cylinder 34 and the outer cylinder 35 in the circumferential direction. And a ball row made up of a plurality of balls 36c as engaging elements. A pair of receiving grooves 36a, 36b are provided in a plurality of sets, in this embodiment, five sets. The width of each receiving groove 36a, 36b in the rotation center line direction A3 is set in the rotation center line direction A3 of the ball row. The driving sprocket 31 is set to be able to translate in the rotation center line direction A3 within a movement range equal to the translation movement range of the switching movement range of the guide pulley 63 of the derailleur 60 described later. In order to define the movement range of the drive sprocket 31 and the outer cylinder 35 and to prevent the ball 36c from falling off, the inner cylinder 34 and the outer cylinder 35 are moved by the ball train in the rotation center line direction A3. First stoppers 34a and 35a to be regulated and second stoppers 34b and 35b are provided.

  The output shaft 24 as a second rotating shaft is rotatably supported by the case 20 via a pair of left and right bearings 38 held in the case portions 21 and 22 in the case 20. Therefore, the case 20 is a member fixed to the vehicle body frame F and rotatably supports the crankshaft 11 and the output shaft 24, and the other of the speed change mechanism M1 through the shafts 11 and 24. It is a support member that supports the structural member and further supports the shift switching mechanism M2.

  The output shaft 24 includes a multistage type for speed change as a second rotating body composed of a predetermined number of second rotating body elements, which is a plurality larger than the number of driving sprockets 31 that are rotating body elements of the driving sprocket body 30. The driven rotor is drive-coupled between the bearings 38 so as to always rotate integrally with the output shaft 24 at a position intersecting the vehicle body center line L1 in plan view. In this embodiment, the multistage driven rotary member has the predetermined number of seven, and the transmission sprockets 41 to 7 serving as second rotary member elements for transmission of seven types having different outer diameters (i.e., tip diameters). This is a multistage driven sprocket body 40 composed of 47.

The seven shift sprockets 41 to 47 are sequentially arranged from the drive sprocket 15 side from the highest speed seven-speed shift sprocket 47 having the smallest outer diameter to the lowest speed first-speed shift sprocket 41 having the largest outer diameter. Arranged side by side in the direction A4 of the rotation center line L4, which is also the rotation center line of the driven sprocket body 40 so as to be low speed, spline-coupled on the outer peripheral surface coaxially with the output shaft 24, and drivingly connected to the output shaft 24 Is done. As shown in FIG. 3, the driven sprocket body 40 is disposed obliquely forward and upward with respect to the main shaft 11 a together with the coaxial output shaft 24.

The drive sprocket body 30 and the driven sprocket body 40 are spanned with a speed change chain 48 as an endless transmission band for flexible speed change, and the rotation is transmitted between the crankshaft 11 and the output shaft 24 by the chain 48. Is done. Specifically, the transmission switching mechanism M2 is alternatively selected from the drive sprocket 31 and the transmission sprockets 41 to 47 by the transmission switching mechanism M2 by switching the chain 48 between the group of transmission sprockets 41 to 47. The chain 48 is looped between an operation sprocket (the speed change sprocket 47 in FIG. 2) as an operation rotating body which is one speed change sprocket around which the chain 48 is selected. Therefore, the output shaft 24 is rotationally driven by the crankshaft 11 at a gear ratio determined by the driving sprocket 31 and the operating sprocket that is drivingly connected via the chain 48. The power of the output shaft 24, drive sprocket 15 is transmitted to the rear wheel W _R through the chain 16 and driven sprocket 17 (see FIG. 1).

  Referring to FIGS. 3, 5, and 6, the shift switching mechanism M <b> 2 operated by the shift operation mechanism 50 includes a derailleur 60 having a guide pulley 63 and a tensioner 70 having a tension pulley 72. The chain 48 is wound around the drive sprocket 31 and the operating sprocket, and a guide pulley 63 and a tension pulley 72 disposed on the slack side of the chain 48.

  Referring also to FIG. 1, the speed change operation mechanism 50 includes a speed change operation member 51 composed of a speed change lever operated by the driver, and a speed change operation member 51 for transmitting the operation of the speed change operation member 51 to the derailleur 60. A wire 52 for operatively connecting 51 and the derailleur 60 and an outer tube 53 covering the wire 52 are provided. The portion of the wire 52 extending longer than the outer tube 53 and near the case 20 is covered with a waterproof and dustproof bellows 57.

Referring to FIGS. 2, 3, and 5 to 7, the derailleur 60 includes a derailleur shaft 61 that is rotatably supported by the case 20, and base end portions 62 a 1 and 62 b 1 are rotationally moved to the derailleur shaft 61 and in the direction of the central axis A derailleur arm 62 that is slidably fitted and supported so as to be able to translate in A5 , and a guide pulley 63 as a guide rotating body that is rotatably supported by the tip portions 62a2 and 62b2 of the derailleur arm 62 And a pin 65 as an operating element for moving the derailleur arm 62 relative to the derailleur shaft 61 in accordance with the speed change operation by the speed change operation mechanism 50, and a balance torque Tb that balances the torque Ta acting on the derailleur shaft 61 from the derailleur arm 62. Are provided on the derailleur shaft 61, and a return spring 64 for returning the derailleur arm 62 to a first position to be described later. In this translational movement, as will be described later, since the center axis L5 of the derailleur shaft 61 and the rotation center line L4 of the driven sprocket body 40 are parallel, the center axis direction A5 is also the rotation center line direction A4. .

The derailleur shaft 61 is supported by the case 20 so that its center axis L5 is parallel to the rotation center line L7 of the guide pulley 63 and the rotation center line L4 of the driven sprocket body 40. Specifically, the one end portion 61a of the derailleur shaft 61 is fitted into the holding hole 25c of the cylindrical portion 25a of the cap 25 that is coupled to the first case portion 21 by the bolt B4, whereby the first case is interposed via the cap 25. The other end 61b is supported by the portion 21 and is supported by the second case portion 22 by fitting into the holding hole 22c of the second case portion 22. Further, as shown in FIG. 3, the derailleur shaft 61 is disposed immediately above the output shaft 24 or the driven sprocket body 40.

  When the derailleur shaft 61 moves in one direction (leftward in FIGS. 2 and 5) in the central axis direction A5, the washer 67 fitted to the step formed on the outer peripheral surface of the derailleur shaft 61 is moved by the cap 25. By abutting the tip of the cylindrical portion 25a in which the holding hole 25c is formed, the movement toward the other (right side in FIGS. 2 and 5) in the central axis direction A5 protrudes from the cap 25 at one end 61a. When a retaining ring 69 fitted in an annular groove formed on the outer peripheral surface comes into contact with a washer 68 fitted to the outer peripheral surface of the portion, the derailleur shaft 61 is regulated in a state that allows rotation.

  A guide tube 56 that guides the wire 52 is fixed, and one end portion 61a in which the insertion hole 61c into which the wire 52 is inserted is formed, and a fishing coil composed of a torsion coil spring in which the one end portion 66a is locked to the cap 25. The other end 66b of the combined spring 66 is locked. The derailleur shaft 61 is acted on by a counterbalance torque Tb based on the spring force generated in the counterbalance spring 66 by the rotation of the derailleur shaft 61 as the derailleur arm 62 rotates. Is defined, and is rotatably supported by the case 20 so that the chain 48 can be switched between the transmission sprockets 41 to 47 having different outer diameters according to the transmission operation by the transmission operation mechanism M2. On the derailleur shaft 61, the derailleur arm 62 and the guide pulley 63 rotate.

  The derailleur shaft 61 is engaged with the actuating element 54 and a receiving hole 61d for accommodating a columnar actuating element 54 coupled to the wire 52 by a set screw 55 for tightening the wire 52 so as to be movable in the direction A5 of the central axis L5. As a result, a guide hole 61e, which is a guide portion for guiding the pin 65 moved by the operating element 54, is formed. The accommodation hole 61d is a cylindrical hole having the central axis L5 of the derailleur shaft 61 as the central axis. The guide hole 61e is composed of a pair of long holes that open to the accommodation hole 61d and are opposed to each other in the diameter direction of the derailleur shaft 61. Each of the long holes is formed in a spiral shape extending in the central axis direction A5 and displaced in the circumferential direction.

The pin 65 is inserted into the guide hole 61e and engages with the derailleur shaft 61 (see FIGS. 2 and 6), and moves while being guided by the guide hole 61e in accordance with a speed change operation by the speed change operation mechanism M2. the arms 62 and the guide pulley 63, in later-described switching movement range in circumference, translating the central axis line direction A5 of the derailleur shaft 61 is rotated with respect to the derailer shaft 61.

  The derailleur arm 62 has a cylindrical boss 62c slidably fitted to the outer periphery of the derailleur shaft 61 so as to translate and rotate in the central axis direction A5, and base end portions 62a1 and 62b1 are press-fitted into the outer periphery of the boss 62c. A pair of first and second arm portions 62a and 62b fixed to each other, and inserted into the inside of a collar 62d which is provided at the tip of both arm portions 62a and 62b and defines the distance between both arm portions 62a and 62b. The rivet 62e as a connecting member for connecting the arm portions 62a and 62b with the collar 62d interposed therebetween, and the first and second members are rotatably supported on the outer periphery of the collar 62d fitted to the outer periphery of the rivet 62e. A support shaft 62f that rotatably supports the guide pulley 63 is provided between the arm portions 62a and 62b.

The guide pulley 63 around which the chain 48 is wound rotates around the support shaft 62f with the center line parallel to the rotation center line L4 of the driven sprocket body 40 and the output shaft 24 as the rotation center line L7.

  Referring also to FIG. 8, the derailleur arm 62 is driven by a pin 65 that moves in accordance with the speed change operation based on the operation of the speed change operation member 51 (see FIG. 1), and on the derailleur shaft 61, the center axis direction A5 The pin 65 inserted into the guide hole 61e is fixed to the derailleur arm 62 so as to be translated and rotated in the circumferential direction of the derailleur shaft 61. For this purpose, both ends of the pin 65 extending through the pair of through holes 62c1 of the guide hole 61e and the boss 62c are press-fitted into the pair of through holes 62b1 formed in the base end portion 62b1 of the second arm portion 62b. To be fixed. Further, a spring accommodating portion 62b2 for accommodating a tension spring 73 of a tensioner 70 described later is formed at the distal end portion of the second arm portion 62b, and the tension spring 73 is disposed so as to surround the rivet 62e in the accommodating portion 62b2. The

  Referring to FIG. 5, the return spring 64 made of a compression coil spring has a case whose one end abuts against the spring receiving portion of the cap 25 and the other end abuts against the base end portion 62a1 of the first arm portion 62a. Arranged within 20. When the derailleur arm 62 occupies the first position, which is the highest speed shift position where the chain 48 is wound around the speed change sprocket 47, the base end portion 62b1 of the second arm portion 62b is connected to the second case 22. The derailleur arm 62 is urged so as to come into contact with the stopper 22d formed with the holding hole 22c. At this time, the pin 65 is positioned at one end portion of the guide hole 61e, and a slight gap is formed between the one edge portion 61f.

3 and 6 , the tensioner 70 is rotatably supported by the holder 71 and the holder 71 rotatably supported by the collar 62d of the derailleur arm 62 between the first and second arm portions 62a and 62b. A tension pulley 72 as a tension rotating body and a tension spring 73 are provided. The holder 71 includes a pair of first and second arms 71a and 71b whose base ends are press-fitted and fixed to the outer periphery of the support shaft 62f, and both arms 71a and 71b. A collar 71c as a support shaft for the tension pulley 72, a rivet 71d as a connecting member that is inserted inside the collar 71c and connects the arms 71a and 71b with the collar 71c interposed therebetween, and a collar 71c And a bearing 71e fitted to the outer periphery.

  The tension pulley 72 is rotatably supported by the collar 71c via a bearing 71e between the first and second arms 71a and 71b. The chain 48 is wound around the guide pulley 63 and the tension pulley 72 using the first and second arms 71a and 71b as chain guides.

As shown in FIG. 3, the tension spring 73 formed of a torsion coil spring has one end 73 a locked to the second arm portion 62 b and the other end 73 b locked to the second arm 71 b of the tensioner 70. The holder 71, and hence the tension pulley 72, is urged by the spring force to apply an appropriate amount of tension to the chain 48 to prevent the chain 48 from sagging.
Further, as shown in FIG. 3, the guide pulley 63 and the tension pulley 72 are disposed rearward of the derailleur shaft 61, and at the position in the vertical direction, the rotation center line L4 of the driven sprocket body 40 and the derailleur shaft The pivot shaft 7 is positioned between the main shaft 11a and the rotation center line L4 in the vertical direction. The main shaft 11a, the output shaft 24, and the derailleur shaft 61 are disposed between the main frame 2 and the down tube 3 (see also FIG. 1).

  Here, referring to FIG. 2, FIG. 3 and FIG. 5, the switching movement of the guide pulley 63 to enable the chain 48 guided by the guide pulley 63 to be changed over to the respective transmission sprockets 41 to 47. The range and the movement path of the guide pulley 63 within the switching movement range will be described.

  The switching movement range of the guide pulley 63 by the speed change operation of the speed change operation mechanism 50 is the first position where the derailleur arm 62 contacts the stopper 22d by the spring force of the return spring 64 and the pin 65 in one direction (in FIGS. 2 and 5). The derailleur arm 62 is defined by a second position where the derailleur arm 62 moves to the left) and abuts against a washer 67 serving as a stopper whose position in the central axis direction A5 is set by the cylindrical portion 25a of the cap 25.

Of the switching movement ranges, the translation movement range, which is the movement range in the central axis direction A5, is the minimum outer diameter in which the guide pulley 63 is a variable speed sprocket positioned at both ends in the central axis direction A4 of the driven sprocket body 40. The transmission sprocket 47 and the maximum outer diameter transmission sprocket 41 are set so as to occupy the same position in the central axis direction A5. Here, the position of the stopper 22d in the first position and the second position The position of the washer 67 at the center axis direction A5.

On the other hand, among the switching movement ranges, the rotational movement range that is the movement range in the rotational direction corresponds to the transmission sprocket 47 having the smallest outer diameter and the transmission sprocket 41 having the largest outer diameter, and the guide pulley 63 has the transmission sprocket 47. , 41 is set to occupy a position at a predetermined distance outward in the radial direction. As shown in FIG. 3, when the chain 48 is wound around the transmission sprocket 47 having the smallest outer diameter among the transmission sprockets 41 to 47, a part of the guide pulley 63 is a driven sprocket body in a side view. Occupies a position overlapping 40.

  Here, the derailleur shaft 61 is rotatable with respect to the case 20, while being supported in a state where movement in the central axis direction A5 is substantially prevented, the rotational movement range is: The torque Ta is generated by the shape of the guide hole 61e and the spring force of the tension spring 73 acting on the derailleur arm 62, and the torque Ta acting on the derailleur shaft 61 via the pin 65, and the torque Ta Depending on the balance torque Tb acting on the derailleur shaft 61 so as to balance the derailleur shaft 61 in the rotational direction when the torque Ta and the balance torque Tb are balanced at the first position and the second position. Is determined from the balance position.

  The directions and magnitudes of these torques Ta and Tb include the spring constant of the tension spring 73, the spring constant of the balancing spring 66, the position of the spring force of each spring 73 and 66, and the derailleur shaft 61, the derailleur arm 62 and the guide. Factors such as the shape of each hole 61e are involved. Therefore, hereinafter, as an example, a case where the rotational movement range and the movement path are set by the spring force of the tension spring 73 and the balance spring 66 will be described.

  2 and 3, when the derailleur arm 62, and hence the guide pulley 63 occupies the first position, both torques Ta and Tb acting on the derailleur shaft 61, that is, one end 73a is the second arm. The torque Ta generated by the spring force of the tension spring 73 locked to the portion 62b and the balance torque Tb are in a balanced state. The adjustment of the balance position so that the guide pulley 63 occupies the set first position is performed by adjusting an initial load which is a spring force of the balance spring 66 at the first position. . Specifically, as shown in FIG. 7, the cap 25 is formed with a pair of insertion holes 25b each having a circular arc-like hole through which a pair of bolts B4 are inserted. By adjusting the position of the cap 25 in the circumferential direction along 25b, the initial load of the balancing spring 66 is adjusted.

  2 and 3, when the derailleur arm 62, and hence the guide pulley 63 occupies the second position, the torque Ta and the balancing torque Tb acting on the derailleur shaft 61 are It is in a balanced state. The spring constant of the balance spring 66 is set so that the guide pulley 63 occupies the set second position. Specifically, when the derailleur arm 62 occupies the second position rotated clockwise with respect to the first position, as shown in FIG. 3, due to the operating force acting on the pin 65 through the speed change operation mechanism 50. As the angle between the derailleur arm 62 and the holder 71 of the tensioner 70 increases, the spring force of the tension spring 73 increases and the torque Ta acting on the derailleur shaft 61 also increases. Thus, due to the torque Ta increased with the rotation of the derailleur arm 62, the derailleur shaft 61 rotates counterclockwise by a predetermined angle from the position in the rotation direction at the first position. A spring force that increases in proportion to the predetermined angle is generated. Then, the spring of the balance spring 66 so that the increased balance torque Tb based on the spring force and the increased torque Ta are balanced at the balance position where the guide pulley 63 occupies the second position set. A constant is set.

  Therefore, at the balance position at the second position, the rotation angle of the guide pulley 63 from the first position is determined by the shape of the guide hole 61e when it is assumed that the derailleur shaft 61 does not rotate. The angle is smaller from the angle (for example, 40 °) by the predetermined angle (for example, 10 °).

  By setting the spring force of the tension spring 73 and the balance spring 66 as described above, the guide pulley 63 and the derailleur shaft 61 are connected to each other within the switching movement range excluding the first position and the second position. When occupying the position, at each shift position, the shift sprockets 42 to 46 occupy the same position in the central axis direction A5 with respect to the shift sprockets 42 to 46, and occupy a position at a predetermined distance radially outward. Moving.

  Therefore, in order to switch to the low speed side by operating the speed change operation member 51, the operation element 54 coupled to the wire 52 is moved in the central axis direction A5 so as to be directed to the one end 61a in the accommodation hole 61d. When moving to one side (left side of FIGS. 2 and 5), the derailleur arm 62 moves within the switching movement range together with the pin 65 guided by the guide hole 61e by the operating force acting through the moving actuating element 54. On the derailleur shaft 61 that rotates against the spring force of the balance spring 66, it translates in the central axis direction A5 against the spring force of the return spring 64 and simultaneously rotates around the derailleur shaft 61.

  The chain 48 guided by the guide pulley 63 that moves together with the derailleur arm 62 that occupies the speed change position determined by the operation amount of the speed change operation member 51 is moved from the group of speed change sprockets 41 to 47 according to the speed change position. The drive sprocket 31 and the operation sprocket are drivingly connected to each other by the chain 48 wound around the alternatively selected operation sprocket.

Next, operations and effects of the embodiment configured as described above will be described.
2 and 3, the derailleur 60 having the derailleur arm 62 in the first position selects the speed change sprocket 47 as the operating sprocket from the group of speed change sprockets 41 to 47. That is, in the state where the seventh speed position is selected as the shift position, the crankshaft 11 that rotates in the forward rotation direction A0 when the driver strokes the pedal 12 is driven by the drive sprocket 31 via the one-way clutch 32 and the slide mechanism S. Is driven to rotate. Therefore, the one-way clutch 32 and the slide mechanism S are provided in a power transmission path from the crankshaft 11 to the drive sprocket 31.

The drive sprocket 31 rotationally drives the transmission sprocket 47, the output shaft 24, and the drive sprocket 15 through a chain 48 at a gear ratio determined by both the sprockets 31 and 47. Driving sprocket 15 rotationally drives the driven sprocket 17 (see FIG. 1) and the rear wheel W _R through the chain 16. In this manner, the power of the crankshaft 11 that is rotationally driven by the driver is transmitted to the output shaft 24 via the drive sprocket 31, the chain 48, and the transmission sprocket 47, and the power of the output shaft 24 is transmitted to the driving force. is transmitted to the rear wheel W _R through the mechanism, the bicycle B travels at the seventh-speed position.

  In order to switch the shift position by the derailleur 60 from the state of the first position, the shift operation member 51 is operated so as to select a shift sprocket 41 to 46 on the lower speed side, for example, the shift sprocket 41, as the operating sprocket. Then, the actuating element 54 that moves to the left in the central axis direction A5 in FIG. 2 by the wire 52 presses the pin 65, and the pin 65 guided to the guide hole 61e is moved to the other edge 61g of the guide hole 61e. Move towards. At this time, the derailleur arm 62 and the guide pulley 63 that move together with the pin 65 are translated leftward in FIG. 2 in the central axis direction A5 on the derailleur shaft 61 and clockwise in FIG. When the derailleur arm 62 rotates and contacts the washer 67, the first speed position, which is the shift position indicated by the two-dot chain line in FIGS. 2 and 3 (this first speed position is also the second position). ). The state of the pin 61p at this time is shown by a two-dot chain line in FIG.

  The chain 48 that moves to the left in FIG. 2 together with the guide pulley 63 is switched from the transmission sprocket 47 to the transmission sprocket 41 and is connected to the drive sprocket 31 via the chain 48. At this time, the drive sprocket 31 that can be moved in the rotation center line direction A3 by the slide mechanism S moves on the main shaft 11a in the rotation center line direction A3 by the component force of the tension of the chain 48 in the rotation center line direction A3. It occupies the position indicated by the two-dot chain line in FIG. Further, the tension pulley 72 occupies a position where a tension spring 73 applies an appropriate amount of tension to the chain 48.

  Further, when the speed change operation member 51 is operated and the wire 52 is loosened so that the operating sprocket is selected from speed change sprockets 42 to 47 higher than the speed change sprocket 41, the return spring 64 is connected to the derailleur arm 62. Is moved toward the first position, the guide pulley 63 selects the higher speed side transmission sprockets 42 to 47 as the operating sprocket, and the chain 48 is replaced with the operating sprocket. Also at this time, simultaneously with the movement of the derailleur arm 62, the chain 48 moves the drive sprocket 31 in the rotation center line direction A3 to a position corresponding to the new shift position. Then, the bicycle B travels at the gear ratio at the new gear shift position.

  Similarly, when switching the shift position, the derailleur arm 62, the guide pulley 63, and the tension pulley 72 move toward the desired shift position according to the operation of the shift operation member 51, and at the same time, the drive sprocket 31 The main shaft 11a is moved in the rotation center line direction A3 by the component force in the rotation center line direction A3 of 48 tension. The derailleur 60 selects one of the operating sprockets corresponding to the desired shift position from the group of sprockets 41 to 47, and the driving sprocket 31 and the operating sprocket are drivingly connected via the chain 48. .

In this way, when the guide pulley 63 translates in the rotation center line direction A4 during shifting, the drive sprocket 31 is moved in the rotation center line direction A3 via the chain 48. Then, following the movement of the derailleur arm 62 for switching the shift position, the drive sprocket 31 moves in the same direction as the direction in which the derailleur arm 62 translates in the switching movement range. The drive sprocket 31 and the driven sprocket body 40 are aligned along a plane orthogonal to the rotation center line L3 (this orthogonal plane is parallel to the vehicle body center line L1 in FIG. 2), that is, parallel to the orthogonal plane. It spans the operating sprocket.

  Therefore, the driving sprocket body 30 is drivingly connected to the crankshaft 11 and the output shaft 24 arranged in parallel to the crankshaft 11 is connected to the driving sprocket body 30 and arranged in the rotation center line direction A4 and more than the driving sprocket 31. In a transmission device T in which a chain 48 spanned with a driven sprocket body composed of a predetermined number of speed-change sprockets 41 to 47 is switched by a speed change mechanism M2, the drive sprocket 31 of the drive sprocket body 30 is a chain. The crankshaft 48 is spanned across the drive sprocket 31 of the drive sprocket body 30 and the variable speed sprockets 41 to 47 of the driven sprocket body 40, that is, the operating sprocket along the orthogonal plane orthogonal to the rotation center line L3. 11 is supported so as to be movable in the rotation center line direction A3, so that the chain 48 is wound around any of the transmission sprockets 41 to 47. In this case, the drive sprocket body 30 moves in the rotation center line direction A3 so that the chain 48 is spanned between the drive sprocket body 30 and the driven sprocket body 40 along the plane perpendicular to the rotation center line L3. The chain 48 is prevented from inclining with respect to the orthogonal plane, and the inter-shaft distance between the crankshaft 11 and the output shaft 24 (this inter-shaft distance is the distance between the rotation center line L3 and the rotation center line L4). Therefore, the chain 48 is prevented from being detached from the drive sprocket 31 or the transmission sprockets 41 to 47 even when the distance between the shafts is small. Furthermore, during coasting when the chain 48 is traveling, when the bicycle B is traveling, the driver stops pedaling 12 and the crankshaft 11 is stopped or rotated in the reverse direction. The chain 48 is prevented from being detached from the drive sprocket 31 or the transmission sprockets 41 to 4.

  Further, the drive sprocket body 30 is composed of one drive sprocket 31. The drive sprocket body 30 is movable in the rotation center line direction A3 by a slide mechanism S provided between the crankshaft 11 and the drive sprocket body 30. As a result, the width of the drive sprocket body 30 in the rotation center line direction A3 is minimized, so that the movement range of the drive sprocket body 30 in the rotation center line direction A3 is minimized. Thus, the transmission T is reduced in size in the rotation center line direction A3.

  In the one-way clutch 32 and the slide mechanism S provided in the power transmission path, the slide mechanism S is disposed between the one-way clutch 32 and the drive sprocket body 30, so that the slide mechanism S and the drive sprocket body 30 are arranged. In comparison with the case where an intermediate member, for example, a one-way clutch is interposed between the drive sprocket body 30 and the inertia when the drive sprocket body 30 moves in the rotation center line direction A3, the movement of the drive sprocket body 30 during shifting is reduced. The speed is increased and the effect of preventing the chain 48 from coming off is further improved.

Shifting the chain 48 spanned between the drive sprocket body 30 and the multistage driven sprocket body 40 composed of a plurality of speed change sprockets 41 to 47 by the speed change mechanism M2 between the speed change sprockets 41 to 47. in the apparatus T, the rear wheel W _R and the driven sprocket member 40 drivingly connected to output shaft 24 that rotates in conjunction normally provided so as to rotate constantly integrally with the output shaft 24, the forward direction of the crankshaft 11 The one-way clutch 32 that transmits the rotation at A0 to the drive sprocket body 30 is provided in the power transmission path from the crankshaft 11 to the drive sprocket body 30, so that the rear wheel can be used even during the inertial operation of the bicycle B. a driven sprocket 40 which rotates together with an output shaft 24 that rotates in conjunction constantly W _R, drive drivingly connected through the chain 48 in the wrapping around to the running state to the driven sprocket member 40 Since the moving sprocket body 30 is in a rotating state and the chain 48 is also in a traveling state, the gear change mechanism M2 can change gears. Therefore, if the bicycle B is in a traveling state, it can be changed at any time when desired. Driving performance is improved.

  The drive sprocket body 30 and the one-way clutch 32 are arranged coaxially with the crankshaft 11 and not overlapped with each other in the rotation center line direction A3 of the crankshaft 11, so that the drive sprocket is arranged coaxially with the crankshaft 11. Since the body 30 and the one-way clutch 32 are not restricted in the radial direction by the crankshaft 11 and the drive sprocket body 30, it is easy to ensure the clutch performance such as the clutch capacity and the one-way clutch. It can be placed without incurring 32 performance degradations. Further, since it is not necessary to reduce the shaft diameter of the shaft portion 11a of the crankshaft 11 in order to provide the one-way clutch 32, it is easy to ensure the required rigidity of the crankshaft 11.

  A derailleur arm 62 that rotatably supports a guide pulley 63 around which a chain 48 that is exchanged between a plurality of transmission sprockets 41 to 47 constituting the driven sprocket body 40 is wound is rotatable and translated in the central axis direction A5. The derailleur shaft 61 that supports the derailleur arm 62 is supported by the case 20 so that its center axis L5 is parallel to the rotation center line L7 of the guide pulley 63 and the rotation center line L4 of the driven sprocket body 40. Rotates around a center axis L4 parallel to the rotation center line L7 of the driven sprocket body 40 and the guide pulley 63, and in addition to the derailleur shaft 61 supporting the derailleur arm 62, the rotation center line L7 of the guide pulley 63 and A special member for maintaining a parallel relationship with the rotation center line L4 of the driven sprocket body 40 is not necessary. As a result, the structure of the derailleur 60 is simplified, the number of parts is reduced, and the cost is reduced.

  Further, the derailleur shaft 61 is rotatably supported by the case 20, and the derailleur 60 is used for a speed change operation of the speed change operation mechanism 50 so as to balance the torque Ta acting on the derailleur shaft 61 from the derailleur arm 62 via the pin 65. Accordingly, a balancing spring that generates a balancing torque Tb acting on the derailleur shaft 61 based on the spring force generated by the rotation of the derailleur shaft 61 due to the rotation of the derailleur arm 62 by the pin 65 moving while being guided by the guide hole 61e. 66 is provided, the derailleur arm 62 rotates and translates with respect to the derailleur shaft 61 by the pin 65 when the chain 48 is switched between the plurality of transmission sprockets 41 to 47, and at the same time, the derailleur shaft 61 The spring of the balance spring 66 that is generated by the torque Ta acting on the derailleur shaft 61 via the pin 65 from the derailleur arm 62 is generated in response to the rotation. Since the balance torque Tb generated by the force balances the torque Ta, the guide pulley 63 occupies a predetermined switching position. At this time, since the derailleur shaft 61 is not fixed to the case 20 and is only restricted in rotation by the balance spring 66, usually an excessive external force exceeding the external force acting on the derailleur arm 62, for example, The derailleur arm 62 is caused by excessive tension generated when the chain 48 is engaged and rotated with the driven sprocket body 40 in the locked state when the shifting operation is performed while the bicycle B is being backed in the state of getting off. When an excessive torque is generated in the pin 61e and the derailleur shaft 61, the derailleur shaft 61 is rotated by deforming the balance spring 66, so that the excessive torque is relieved. The excessive torque acting on the pin 65 and the derailleur shaft 61 is reduced, so that deformation of the members due to the excessive torque is prevented, and the derailleur 60 As a result, the durability of the transmission T is improved.

  Since the chain 48 is used for drivingly connecting the operating sprocket 31 and the driving sprocket 31 that are drivingly connected to the output shaft 24 to which the chain 16 is drivingly connected, the position of the vehicle body frame F and the pivot shaft 7 can be changed. In order to cope with this, it is easy to change the arrangement of the output shaft 24 in the transmission T, and the degree of freedom of the arrangement is increased.

The derailleur 60 provided in the transmission T includes a derailleur shaft 61, a derailleur arm 62 that is movably supported by the derailleur shaft 61, a plurality of derailleur arms 62 that are rotatably supported by the derailleur arm 62 and that constitute the driven sprocket body 40. And a guide pulley 63 around which a chain 48 to be exchanged between the transmission sprockets 41 to 47 is wound, and the transmission T has a case 20 fixed to the main frame 2 and the down tube 3 of the vehicle body frame F. The derailleur 60 is housed in the case 20, and the derailleur shaft 61 is rotatably supported, so that the derailleur shaft 61 houses the derailleur shaft 61, the derailleur arm 62 and the guide pulley 63 that constitute the derailleur 60. because they are supported by using the case 20 for, upon the number of parts the structure of the de Ireira 60 is simplified is reduced, hii Cost is reduced is. Further, the derailer shaft 61, derailer arm 62 and the guide pulley 63, Ru is housed in a case 20.

  The crankshaft 11 includes a main shaft 11a that penetrates the case 20, and a pair of crank arms 11b that are coupled to both ends of the main shaft 11a outside the case 20 and to which the pedal 12 is rotatably mounted. The case 20 is disposed in the vicinity of the crankshaft 11 having the crank arm 11b, and the crank arm 11b rotates in the lateral direction of the case 20 when the driver strokes the pedal 12.

The transmission device T includes a transmission mechanism M1 that is a mechanism that is switched to a desired transmission position by the derailleur 60 and that is housed in the case 20. The transmission mechanism M1 is coaxially disposed on the main shaft 11a and is connected to the crankshaft. The case 20 includes the derailleur 60 in addition to the drive sprocket 31 driven by the shaft 11, the driven sprockets 41 to 47, and the chain 48 spanned over the driving sprocket body 30 and the driven sprocket body 10. a drive sprocket 31 constituting the transmission mechanism M1, the driven sprocket 41 to 47 and the chain 48 is Ru housed.

  The transmission T includes an output shaft 24 that is coaxially coupled to the driven sprockets 41 to 47 and accommodated in the case 20, and the output shaft 24 is disposed so as to be within the rotation locus of the crank arm 11b. The output shaft 24 is disposed in the rotation locus of the crank arm 11b that rotates about the main shaft 11a of the crankshaft 11 to which the drive sprocket 31 is drivingly connected.

Includes a swing arm 8 of a pair for supporting the rear wheel W _R while being swingably supported on a pivot shaft 7 which is provided on the main frames 2, by a pivot shaft 7 which penetrates the case 20, 1 A pivot shaft 7 that swingably supports the pair of swing arms 8 is disposed through a case 20 disposed with respect to the vehicle body frame F so that the main shaft 11a of the crankshaft 11 penetrates.

Hereinafter, an example in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
The case 20 of the transmission T may be made of synthetic resin.

A belt may be used as the endless transmission band for speed change, and a pulley may be used as the driving rotating body and the driven rotating body. Further, an endless belt as an output endless transmission belt to the rear wheel W _R is used, the pulley may be used as the output driving rotating member and the output driven rotating member.

  In the above embodiment, the drive sprocket 30 is composed of the drive sprocket 31 that is one rotating body element. However, the drive sprocket 30 is composed of a plurality of drive sprockets arranged in the rotation center line direction A3 and having different tip diameters. Also good.

  The engagement mechanism provided in the slide mechanism S includes a plurality of ridges formed on the outer peripheral surface of the inner cylinder 34 and the inner peripheral surface of the outer cylinder 35, and a plurality of grooves into which the ridges are respectively fitted. It may be a spline.

  When the drive sprocket body is arranged separately from the crankshaft 11 and coaxially with the intermediate rotation shaft that is rotationally driven by the crankshaft 11 via the transmission mechanism, the one-way clutch 32 is separated from the crankshaft 11. In the power transmission path reaching the drive sprocket body, for example, it may be provided between the intermediate shaft and the drive sprocket body.

1 is a schematic left side view of a bicycle to which an embodiment of the present invention is applied and to which the present invention is applied. It is sectional drawing in the II-II arrow of FIG. 3 in the transmission equipped with the bicycle of FIG. FIG. 3 is an arrow view and a cross-sectional view taken along the line III-III in FIG. 2 in a state in which a second case portion of the transmission installed in the bicycle in FIG. 1 is removed. It is a sectional view taken along the IV-IV arrow of Fig. It is sectional drawing in the VV arrow of FIG. It is sectional drawing of the derailleur and tensioner in the VI-VI arrow view of FIG. It is a VII arrow line view of FIG. It is sectional drawing in the VIII-VIII arrow of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Head pipe, 2 ... Main frame, 3 ... Down tube, 4 ... Saddle frame, 5 ... Front fork, 6 ... Saddle, 7 ... Pivot shaft, 8 ... Swing arm, 9 ... Axle, 10 ... Suspension, 11 ... Crank Shaft, 12 ... pedal, 13 ... bush, 14 ... bearing, 15 ... driving sprocket, 16 ... driven sprocket, 17 ... chain, 18 ... collar,
20 ... Case, 21, 22 ... Case part, 23 ... Through hole, 24 ... Output shaft, 25 ... Cap,
30 ... Drive sprocket body, 31 ... Drive sprocket, 32 ... One-way clutch, 33 ... Bearing, 34 ... Inner cylinder, 35 ... Outer cylinder, 36 ... Engagement mechanism, 37 ... Chain guide, 40 ... Driving sprocket body, 41- 47 ... shift sprocket, 48 ... chain,
50: Transmission operation mechanism, 51: Transmission operation member, 52: Wire, 53 ... Outer tube, 54 ... Actuating element, 55 ... Set screw, 56 ... Guide tube, 57 ... Bellows,
60 ... derailleur, 61 ... derailleur shaft, 62 ... derailleur arm, 63 ... guide pulley, 64 ... return spring, 65 ... pin, 66 ... balancing spring, 67, 68 ... washer, 69 ... retaining ring, 70 ... tensioner, 71 ... Holder, 72 ... Tension pulley, 73 ... Tension spring,
B: Bicycle, F: Body frame, W _F : Front wheel, W _R : Rear wheel, T: Transmission, L1: Vehicle center line, A0: Forward rotation direction, A3, A4, A5 ... Direction, L2: Center axis ( Oscillation center line) L3, L4, L6, L7 ... Rotation center line, L5 ... Center axis, B1-B4 ... Bolt, H ... Virtual plane, M1 ... Transmission mechanism, M2 ... Transmission switching mechanism, S ... Slide mechanism, Ta … Torque, Tb… Balance torque.

Claims (7)

In a bicycle including a vehicle body frame, a crankshaft, and a transmission including a derailleur,
The derailleur is an endless shaft that is interchangeable between a derailleur shaft, a derailleur arm supported by the derailleur shaft, and a plurality of rotating body elements that are rotatably supported by the derailleur arm and constitute a multistage driven rotating body. A guide rotating body around which a transmission band is wound,
The transmission includes a case coupled to the vehicle body frame, a transmission mechanism that is a mechanism that is switched to a desired transmission position by the derailleur, and an output shaft that is coaxially coupled to the driven rotating body,
The derailleur, the speed change mechanism, and the output shaft are housed in the case, and the derailleur shaft is supported,
The crankshaft has a main shaft that penetrates the case,
The speed change mechanism is disposed coaxially with the main shaft and is drivingly connected and rotationally driven by the crankshaft, the driven rotating body disposed above the main shaft, the drive rotating body, The endless transmission belt stretched over the driven rotating body,
The derailleur shaft is disposed directly above the output shaft or the driven rotating body,
The derailleur arm is supported by the derailleur shaft so as to be capable of rotational movement in the circumferential direction on the derailleur shaft and translational movement in the direction of the rotation center line of the driven rotating body,
A part of the guide rotator occupies a position overlapping the driven rotator in a side view when the endless transmission band is wound around the rotator element having the smallest outer diameter among the plurality of rotator elements. Bicycle characterized by that. A pair of swing arms that are swingably supported by a pivot shaft provided in the vehicle body frame and pivotally support a rear wheel;
The pivot shaft is configured to penetrate the case, a bicycle according to claim 1 Symbol mounting, characterized in that to support the case. The output shaft and the driven rotor are disposed obliquely upward and forward with respect to the main shaft,
The endless transmission band is wound around the guide rotating body and a tension rotating body of a tensioner that applies tension to the endless transmission band,
The guide rotator and the tension rotator are disposed rearward of the derailleur shaft, and are vertically positioned between the rotation center line of the driven rotator and the center axis of the derailleur shaft. Position to,
The bicycle according to claim 2 , wherein the pivot shaft is positioned between the main shaft and the rotation center line of the driven rotating body in a vertical position . The vehicle body frame includes a main frame extending rearward from the head pipe, and a down tube disposed below the main frame,
The bicycle according to any one of claims 1 to 3 , wherein the main shaft, the output shaft, and the derailleur shaft are arranged between the main frame and the down tube . The drive rotator provided on the main shaft so as to be movable in the direction of the rotation center line of the main shaft moves in the direction of the rotation center line of the main shaft via the endless transmission band when the guide rotation body moves in translation. The bicycle according to any one of claims 1 to 4, wherein the bicycle is moved .   The bicycle according to any one of claims 1 to 5, wherein the case is made of metal.   The bicycle according to any one of claims 1 to 5, wherein the case is made of a synthetic resin.

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