TWM536644U - Bicycle front derailleur - Google Patents

Description

Bicycle front derailleur

The present invention relates to a front derailleur for bicycles.

A conventional bicycle front derailleur is provided with a chain guide that moves a chain with respect to a front sprocket. The front sprocket of the wrapped chain is changed by causing the chain guide to move the chain.

When the chain guide moves the chain from the small-diameter front sprocket to the large-diameter front sprocket, if the chain guide moves too much, the chain will move beyond the front sprocket of the winding target, and the chain may fall off from the front sprocket. .

The purpose of the present invention is to provide a bicycle front derailleur that can suppress the situation in which the chain is detached from the front sprocket.

(1) The bicycle front derailleur of the present invention has: a base member attached to the frame of the bicycle, a link mechanism attached to the base member, and a chain guide attached to the base member via the link mechanism and moving the chain with respect to the front sprocket of the bicycle; The chain guide includes: a first guide plate, a second guide plate, and a restricting portion; the first guide plate includes: a first end edge; and a second end closer to the link mechanism than the first end edge The second guide plate is disposed at a position closer to the frame than the first guide plate in a state where the base member is attached to the frame, and the restricting portion includes a resin and is attached to the first guide plate. The inner surface of the second guide plate side; the restricting portion is disposed to be separated from the first end edge of the first guide plate.

(2) The bicycle front derailleur according to the second aspect of the invention, wherein the restricting portion includes the first portion and is closer to the first portion. The second portion of the first end edge of the first guide plate; the first portion protrudes toward the second guide plate side from the second portion.

(3) The bicycle front derailleur according to the third aspect of the present invention, wherein the first part and the second part include the resin, the first part and the first part and the second part. The second part described above is formed integrally.

(4) The bicycle front derailleur according to the fourth aspect of the present invention, wherein the second part includes the inclined surface, the inclined surface, the bicycle front derailleur according to the above aspect (2) or (3) The amount of protrusion toward the second guide plate side toward the distal end portion side farthest from the link mechanism from the proximal end portion side of the first guide plate that is connected to the link mechanism The smaller.

The bicycle front derailleur according to any one of the above aspects of the present invention, wherein the inner side of the first guide plate is the bicycle front derailleur according to any one of the above aspects of the present invention. The first convex portion that protrudes toward the second guide plate between the first end edge of the first guide and the restricting portion.

(6) The bicycle front derailleur according to the sixth aspect of the present invention, wherein the first convex portion extends to the first portion of the first guide plate. End edge.

(7) The bicycle front derailleur according to the seventh aspect of the present invention, wherein the bicycle front derailleur according to the above (5) or (6), is formed between the restricting portion and the first convex portion. There is a gap.

The bicycle front derailleur according to any one of the above aspects (5) to (7), wherein the second part is the first part The convex portion protrudes toward the second guide plate side.

The bicycle front derailleur according to any one of the above aspects of the present invention, wherein the first convex portion includes a contact. The contact portion is in contact with the chain of the bicycle to move the chain from the large-diameter front sprocket toward the small-diameter front sprocket side.

(10) The bicycle front derailleur according to the tenth aspect of the present invention, wherein the inner side surface of the first guide plate includes a second convex portion, The second convex portion is arranged in The contact portion is closer to the second end edge side and protrudes toward the second guide plate side, and the second protrusion portion protrudes toward the second guide plate side from the contact portion.

(11) The bicycle front derailleur according to the eleventh aspect of the present invention, wherein the first portion of the bicycle front derailleur according to the first aspect of the present invention is further directed toward the second guide than the second convex portion. The side of the board protrudes.

The bicycle front derailleur according to any one of the above aspects of the present invention, wherein the restricting portion is bonded to the first 1 The inner surface of the guide plate.

(13) The bicycle front derailleur according to the above-described (12), further comprising an undercoat layer, wherein the undercoat layer is located in the restricting portion and the first 1 between the inner faces of the guide plates.

(14) The bicycle front derailleur according to the fourteenth aspect of the present invention, wherein the undercoat layer is a vulcanized adhesive layer.

(15) The bicycle front derailleur according to any one of the above-mentioned (12), wherein the restricting portion is embedded in: a recess formed by the inner surface of the guide plate.

(16) The bicycle front derailleur according to any one of the above-mentioned (12), wherein the restricting portion is adhered by insert molding. Connected to the above inner surface.

The bicycle front derailleur according to any one of the above aspects of the present invention, wherein the outer periphery of the restricting portion is The inner surface of the first guide plate is located further inside than the outer circumference of the first guide plate.

(18) The bicycle front derailleur according to any one of the above-mentioned (1) to (17), further comprising a low position adjusting bolt, the lower position The adjusting bolt is used to adjust the position of the chain guide when the chain of the bicycle is switched from the large diameter of the front sprocket to the small diameter of the front sprocket.

(19) The bicycle front derailleur according to any one of the above aspects of the present invention, wherein the resin comprises rubber.

The bicycle front derailleur of the present invention can suppress the situation in which the chain is detached from the front sprocket.

F‧‧‧Frame

S‧‧‧Front sprocket

S1‧‧‧ Large diameter sprocket (large diameter front sprocket)

S2‧‧‧Small diameter sprocket (small diameter front sprocket)

C‧‧‧Chain

10‧‧‧ Front derailleur (front derailer for bicycles)

12‧‧‧Base member

14, 104‧‧‧ linkage mechanism

16‧‧‧Chain guides

18‧‧‧Low adjustment bolt

52‧‧‧1st guide

52A‧‧‧outweek

54‧‧‧2nd guide

56‧‧‧Restrictions

62‧‧‧1st edge

64‧‧‧2nd edge

70‧‧‧ base end

72‧‧‧ front end

74‧‧‧ inside

76‧‧‧1st convex

76C‧‧‧Contacts

78‧‧‧2nd convex

80‧‧‧Part 1

82‧‧‧Part 2

82A‧‧‧ sloped surface

84‧‧‧Undercoat

Fig. 1 is a side view of a bicycle on which a bicycle front derailleur according to the first embodiment of the present invention is mounted.

Fig. 2 is a front elevational view of the bicycle front derailleur of Fig. 1.

Fig. 3 is a rear elevational view of the bicycle front derailleur of Fig. 2.

Fig. 4 is a first perspective view of the bicycle front derailleur according to Fig. 2.

Fig. 5 is a second perspective view of the bicycle front derailleur according to Fig. 2.

Fig. 6 is a front elevational view showing the first guide and the restricting portion of Fig. 5.

Fig. 7 is a perspective view of the first guide and the regulating portion of Fig. 5.

Fig. 8 is an exploded perspective view showing the first guide plate and the regulating portion in Fig. 7;

Fig. 9 is a side view of the first guide plate and the regulating portion of Fig. 7 as seen from the lower side.

Fig. 10 is a partially enlarged view of Fig. 9.

Figure 11 is a cross-sectional view taken along line 11-11 of Figure 9.

Fig. 12 is a first operation diagram when the chain is moved by the chain guide of Fig. 6.

Fig. 13 is a second operation diagram when the chain is moved by the chain guide of Fig. 6.

Fig. 14 is a third operation diagram when the chain is moved by the chain guide of Fig. 6.

Fig. 15 is a first schematic view showing the relationship between the chain guide of Fig. 6 and the chain.

Fig. 16 is a second schematic view showing the relationship between the chain guide of Fig. 6 and the chain.

Fig. 17 is a third schematic view showing the relationship between the chain guide of Fig. 6 and the chain.

Figure 18 is a first schematic diagram showing the relationship between the hypothetical chain guide and the chain.

Fig. 19 is a first perspective view of the bicycle of the bicycle front derailleur according to the second embodiment of the present invention.

Fig. 20 is a second perspective view of the bicycle front derailleur according to Fig. 19.

(First embodiment)

Referring to Fig. 1, the structure of the bicycle front derailleur will be described.

The bicycle front derailleur 10 (hereinafter referred to as "front derailleur 10") is attached to the seat tube F1 of the frame F of the bicycle 1. A plurality of front sprockets S are superposed on the bottom bracket (not shown) at the lower end portion of the seat tube F1. The plurality of front sprocket wheels S include a large-diameter front sprocket S1 (hereinafter referred to as "large-diameter sprocket S1") and a larger-diameter sprocket S1 having a smaller diameter front sprocket S2 (hereinafter referred to as " Small diameter sprocket S2"). In one example, the large diameter sprocket S1 phase smaller diameter sprocket S2 is disposed further from the frame F. The bicycle 1 may also include three or more plural front sprockets S.

As shown in FIG. 2, the front derailleur 10 is provided with a base member 12, a link mechanism 14, and a chain guide 16. In one example, the front derailleur 10 is further provided with a lower adjustment bolt 18. The front derailleur 10 is connected to an operation portion R (refer to FIG. 1) provided on the handlebar H by a Bowden cable W. The Bowden cable W is provided with an outer casing W1 and an inner cable W2 shown in Fig. 3 . The shifting operation of the front derailleur 10 is performed by moving the inner cable W2 in the outer casing W1.

As shown in FIG. 2, the base member 12 can be attached to the frame F of the bicycle 1. The base member 12 is provided with a mounting portion 20 and an outer casing Hold 22 (refer to Figure 3). The mounting portion 20 includes a washer 20A, a first connecting portion 20B (refer to FIG. 3), a screw seat portion 20E, and a second connecting portion 20C. The base member 12 is attached to the frame F by sandwiching a bracket (not shown) fixed to the frame F by the washer 20A and the screw seat portion 20E. In another example, the base member 12 includes a clamping portion that is attached to the frame F by fixing the clamping portion to the outer circumference of the frame F.

As shown in FIG. 3, the first connecting portion 20B is located further above the screw seat portion 20E. The second connecting portion 20C is located further below the screw seat portion 20E. As shown in FIG. 4, the third connecting portion 20D protrudes away from the frame F in a state where the front derailleur 10 is attached to the frame F in a state of being attached to the frame F. The link mechanism 14 is movably connected to the first connecting portion 20B, the second connecting portion 20C, and the third connecting portion 20D.

As shown in FIG. 3, the outer casing holding portion 22 is a hole portion into which the Bowden cable W is inserted. The outer casing holding portion 22 is provided in the mounting portion 20. The outer casing holding portion 22 has a small diameter portion (not shown) inside to restrict the movement of the end portion of the outer casing W1 of the Bowden cable W inserted into the outer casing holding portion 22, and does not limit the inner cable. W2's movement.

As shown in FIGS. 4 and 5, the link mechanism 14 is attached to the base member 12. The link mechanism 14 includes an input link 28, a first link 30, a second link 32, an expansion link 34, a connection link 36, a first shaft portion 38, a second shaft portion 40, and a third shaft portion. 42. The fourth shaft portion 44, the fifth shaft portion 46, the sixth shaft portion 48, and the biasing member 50.

As shown in Figure 3, the input link 28 is provided with cable mounting. Part 28C. The cable attachment portion 28C is attached to the inner cable W2 of the Bowden cable W. Specifically, when the end of the inner cable W2 is sandwiched between the washer 28D and the cable mounting portion 28C, the inner cable W2 is opposed by screwing the bolt 28E into the cable mounting portion 28C. The input link 28 is mounted to the input link 28.

As shown in FIG. 5, the first end portion 28A of the input link 28 is rotatably connected to the first connecting portion 20B via the first shaft portion 38 via the first connecting portion 20B. The second end portion 28B of the input link 28 is rotatably connected to the first end portion 36A of the connecting link 36 via the second shaft portion 40 via the connecting link 36.

The first end portion 30A of the first link 30 is rotatably connected to the second connecting portion 20C via the third shaft portion 42 with respect to the second connecting portion 20C. The second end portion 30B of the first link 30 is rotatably connected to the chain guide 16 via the fourth shaft portion 44 with respect to the chain guide 16 .

As shown in FIG. 4, the first end portion 32A of the second link 32 is rotatably connected to the third connecting portion 20D via the fifth shaft portion 46 with respect to the third connecting portion 20D. The second end portion 32B of the second link 32 is rotatably coupled to the chain guide 16 with respect to the chain guide 16.

The first end portion 34A of the expansion link 34 is connected to the second end portion 36B of the connection link 36 via the sixth shaft portion 48. The second end portion 34B of the expansion link 34 is rotatably connected to the first link portion 30 of the first link portion 30A and the first end portion 30A of the first link 30 via the second shaft portion 40. End 30A.

The biasing member 50 is disposed on the first link 30 and the chain guide Between 16. The biasing member 50 is, for example, a coil spring, and is disposed around the fourth shaft portion 44. The biasing member 50 applies a force toward the first direction X1 to the chain guide 16. The first direction X1 is a state in which the chain guide 10 is attached to the bicycle 1 and the chain guide 16 approaches the direction of the frame F (refer to FIG. 2).

When the inner cable W2 shown in FIG. 3 is moved toward the operation portion side by the operation portion R (refer to FIG. 1), the link mechanism 14 is wound by the respective links 28, 30, 32, 34, and 36. The shaft portions 38, 40, 42, 44, 46, 48 are rotated, and the angles formed by the mutually connected links 28, 30, 32, 34, 36 are changed, and the second end portion 30B of the first link 30 is made. Move away from the frame F. Thereby, the chain guide 16 connected to the second end portion 30B of the first link 30 is moved in the second direction X2 opposite to the first direction X1.

The link mechanism 14 causes the respective links 28, 30, 32, 34, 36 to surround the shaft portions 38, 40, 42, 44 by the force of the biasing member 50 when the inner cable W2 moves toward the opposite side of the operating portion. , 46, 48 rotation. Thereby, the angle formed by the interconnected links 28, 30, 32, 34, 36 is changed, and the second end 30B of the first link 30 is moved in the direction approaching the frame F. Thereby, the chain guide 16 connected to the second end portion 30B of the first link 30 is moved in the first direction X1.

As shown in Fig. 1, since the small-diameter sprocket S2 is disposed at a position where the larger-diameter sprocket S1 is closer to the frame F, when the chain guide 16 moves in the first direction X1, the chain guide 16 is from the large diameter. The sprocket S1 side moves toward the small diameter sprocket S2 side. When the chain guide 16 faces the second direction When the X2 moves, the chain guide 16 moves from the small diameter sprocket S2 side toward the large diameter sprocket S1 side.

The lower adjustment bolt 18 shown in Fig. 2 is for adjusting the position of the chain guide 16 when the chain C of the bicycle 1 is switched from the large diameter sprocket S1 to the small diameter sprocket S2. By adjusting the lower adjustment bolt 18, the stop position of the chain guide 16 in the first direction X1 side when the inner cable W2 shown in FIG. 3 moves toward the opposite side of the operation portion is set.

The chain guide 16 is attached to the base member 12 via a link mechanism 14. The chain guide 16 moves the chain C relative to the front sprocket S of the bicycle 1. The chain guide 16 includes a first guide 52, a second guide 54, and a regulating portion 56 (refer to Fig. 6).

The second guide 54 shown in FIG. 3 is disposed closer to the frame F than the first guide 52 in a state where the base member 12 is attached to the frame F (refer to FIG. 1). The second guide 54 contains metal. The metal is, for example, an aluminum alloy or iron. The second guide 54 is formed by bending, cutting, or the like on the metal plate. In other examples, the second guide 54 includes carbon fibers. The second guide 54 includes a base end portion 58 that is connected to the link mechanism 14 and a distal end portion 60 that is the farthest from the link mechanism 14. A plate portion 60A that can be in contact with the chain C (refer to FIG. 1) is attached to the inner surface 54A of the second guide 54. The plate portion 60A contains a resin. Alternatively, the plate portion 60A may be omitted, so that the inner surface 54A of the second guide plate 54 can directly contact the chain C.

The first guide 52 shown in Fig. 6 contains metal. The metal is, for example, an aluminum alloy or iron. The first guide 52 is bent by bending the metal plate It is formed by curved machining and cutting. In other examples, the first guide 52 includes carbon fibers. The first guide 52 includes a first end edge 62 and a second end edge 64 closer to the link mechanism 14 than the first end edge 62. In one example, the first guide 52 further includes a third end edge 66, a fourth end edge 68, a base end portion 70 connected to the link mechanism 14, and a distal end portion 72 that is furthest from the link mechanism 14. In the first guide 52, the front derailleur 10 is attached to the bicycle 1 (refer to FIG. 1), and the distal end portion 72 is disposed on the rear side of the bicycle 1, and the proximal end portion 70 is disposed on the upper side.

The first end edge 62 includes an end edge of the outer circumference 52A of the first guide 52 that faces the sprocket S (refer to FIG. 2). The first end edge 62 is curved along the outer shape of the sprocket S. That is, the first end edge 62 is an end edge that extends in the longitudinal direction of the first guide 52 along the lower end of the first guide 52. The second end edge 64 includes an end edge on the opposite side of the first end edge 62 of the outer circumference 52A of the first guide 52. The third end edge 66 includes an end edge that connects the first end edge 62 and the second end edge 64 on the proximal end portion 70 side of the outer circumference 52A of the first guide plate 52. The fourth end edge 68 includes an end edge that connects the first end edge 62 and the second end edge 64 on the distal end portion 72 side of the outer circumference 52A of the first guide plate 52.

The proximal end portion 70 of the first guide 52 is bent toward the second guide 54. The proximal end portion 58 of the second guide 54 is bent toward the first guide 52. The proximal end portion 70 of the first guide 52 and the proximal end portion 58 of the second guide 54 are fixed to each other via a rivet (not shown). The front end portion 72 of the first guide 52 is bent toward the second guide 54. The front end portion 72 of the first guide 52 and the front end portion 60 of the second guide 54 are fixed to each other via the rivet B. In the first guide A space 16S for inserting the chain C is formed between the inner surface 74 of the plate 52 facing the second guide 54 and the inner surface 54A of the second guide 54 facing the first guide 52.

The inner surface 74 of the first guide 52 includes a first convex portion 76 and a second convex portion 78. The first convex portion 76 and the second convex portion 78 are integrally provided with the first guide plate 52. The first convex portion 76 and the second convex portion 78 may be attached to the inner surface 74 instead of the first guide plate 52. The first convex portion 76 protrudes toward the second guide 54 side. The first convex portion 76 extends to the first end edge 62 of the first guide 52 . The first convex portion 76 extends to the third end edge 66 of the first guide 52 . The first convex portion 76 has an L shape along a connecting portion (a corner portion located at a lower end of the front side of the first guide 52) along the first end edge 62 and the third end edge 66.

The first convex portion 76 includes a first inclined surface 76A, a second inclined surface 76B, and a contact portion 76C. The first inclined surface 76A is provided at a portion along the first end edge 62 of the first convex portion 76. The first inclined surface 76A has a smaller amount of projection toward the second guide 54 side as it goes from the base end portion 70 side of the first guide 52 toward the distal end portion 72 side. The second inclined surface 76B is provided at a portion along the third end edge 66. The second inclined surface 76B has a smaller amount of projection toward the second guide 54 side as it goes from the distal end portion 72 side of the first guide 52 toward the end edge 66 side.

The contact portion 76C is provided at a boundary portion between the first inclined surface 76A and the second inclined surface 76B. The contact portion 76C extends from the first end edge 62 toward the second end edge 64. The contact portion 76C has the largest amount of protrusion toward the second guide 54 (refer to FIG. 3) in the first convex portion 76. Contact portion 76C, Contact with the chain C of the bicycle 1 causes the chain C to move from the large diameter sprocket S1 toward the small diameter sprocket S2 side.

As shown in FIG. 7, the second convex portion 78 is disposed closer to the second end edge 64 than the contact portion 76C, and protrudes toward the second guide 54 side. The second convex portion 78 protrudes toward the second guide 54 side from the contact portion 76C. That is, the amount of protrusion of the second convex portion 78 is larger than the amount of protrusion of the contact portion 76C.

As shown in FIG. 8, the restricting portion 56 includes resin and is attached to the inner surface 74 of the first guide 52 on the second guide 54 side. The entire outer circumference of the restricting portion 56 is located further inside the outer circumference 52A of the first guide 52 than the inner surface 74 of the first guide 52. A gap 52S is formed between the restricting portion 56 and the first convex portion 76. In other words, the restricting portion 56 is attached to the inner surface 74 in a state where at least a portion of the portion facing the first convex portion 76 in the outer periphery of the restricting portion 56 is not in contact with the first convex portion 76. The restricting portion 56 is disposed apart from the first end edge 62 of the first guide 52 . The restricting portion 56 is disposed inside the L-shape of the first convex portion 76. The first convex portion 76 protrudes toward the second guide 54 side between the first end edge 62 of the first guide 52 and the regulating portion 56.

The restricting portion 56 includes a first portion 80 and a second portion 82 that is closer to the first end edge 62 of the first guide 52 than the first portion 80. The first portion 80 and the second portion 82 contain a resin. The resin contains rubber or polyacetic acid. The rubber contains a thermoplastic synthetic rubber or a thermosetting synthetic rubber. The thermosetting synthetic rubber is, for example, NBR (nitril-butadiene rubber). The first part 80 and the second part 82 are formed as one body.

As shown in Fig. 9, the first portion 80 protrudes toward the second guide 54 (refer to Fig. 5) from the second portion 82. The second portion 82 includes an inclined surface 82A. The inclined surface 82A faces the second guide 54. The inclined surface 82A has a smaller amount of projection toward the second guide 54 side as it goes from the proximal end portion 70 side (end edge 66 side) of the first guide 52 toward the distal end portion 72 side.

As shown in FIG. 10, the first portion 80 protrudes toward the second guide 54 side than the second convex portion 78. The second portion 82 protrudes toward the second guide 54 side than the first convex portion 76. The amount of protrusion D toward the second guide 54 side is the amount of protrusion DA of the first convex portion 76, the amount of protrusion DD of the second portion 82, the amount of protrusion DB of the second protrusion 78, and the amount of protrusion of the first portion 80. The order of the DCs becomes larger (in this order, it is closer to the side of the second guide 54).

The mounting state of the restricting portion 56 and the first guide 52 will be described with reference to Fig. 11 .

The restricting portion 56 is adhered to the inner surface 74 of the first guide 52. Further, an undercoat layer 84 is disposed between the restricting portion 56 and the inner surface 74 of the first guide. The undercoat layer 84 is a vulcanized adhesive layer. The restricting portion 56 is bonded to the inner surface 74 by insert molding. Specifically, the manufacturing method of the first guide 52 is performed in the order of the first step, the second step, the third step, the fourth step, the fifth step, and the sixth step, in one example.

The first step includes a step of bending and cutting the metal plate of the material of the first guide 52. The second step includes a step of cleaning the first guide 52. The third step includes: a restriction portion 56 to be enclosed in the mold The material is in close contact with the undercoat 84 applied to the surface 74, and the restriction portion 56 is attached to the inner surface 74 by hardening the material. The fourth step includes a step of barreling the first guide 52. The fifth step includes a step of polishing and polishing the first guide 52. In the sixth step, a plating layer is applied to the inner surface 74 of the first guide 52. Since the restricting portion 56 is attached to the inner surface 74 by the bonding method, it is not necessary to process the hole portion or the like for mounting the restricting portion 56 on the outer surface of the first guide 52. Therefore, the restriction portion 56 can be attached without undue appearance.

The operation of switching the chain C from the small diameter sprocket S2 to the large diameter sprocket S1 will be described with reference to Figs. 12 to 14 . 12 to 14 show only the first guide 52 and the restricting portion 56 of the front derailleur 10.

As shown in Fig. 12, when the chain C is wound around the small-diameter sprocket S2, when the inner cable W2 is moved by the operation portion R (refer to Fig. 1), the chain guide 16 faces the second direction X2. mobile. At this time, the second guide 54 (refer to FIG. 2) comes into contact with the chain C, and pushes the chain C to the large-diameter sprocket S1 from the first direction X1 side.

As shown in Fig. 13, the chain C pressed to the large-diameter sprocket S1 from the first direction X1 side is oriented toward the large-diameter sprocket S1 by the pin (not shown) engaged with the large-diameter sprocket S1. The peripheral movement. By engaging the chain C with the tooth portion of the large-diameter sprocket S1, the chain C is wound around the large-diameter sprocket S1 as shown in Fig. 4.

Referring to Figures 15 to 18, the action and effect of the front derailleur 10 will be described.

As shown in Fig. 15, when the current derailleur 10 switches the chain C from the small diameter sprocket S2 to the large diameter sprocket S1, the chain C is embedded in the tooth portion ST of the large diameter sprocket S1 or before being embedded. In the state, when the second guide 54 moves excessively in the second direction X2, or when the chain C generates a force moving in the second direction X2 due to vibration or the like, the chain C larger diameter sprocket S1 is further oriented in the second direction. When the X2 side moves, it may fall off from the tooth portion ST of the large diameter sprocket S1. The front derailleur 10 restricts the movement of the chain C in the second direction X2 when the chain C is fitted in the state of the tooth portion ST of the large-diameter sprocket S1 or before the insertion, and the second portion 82 of the restriction portion 56 restricts the movement of the chain C in the second direction X2. Therefore, the possibility that the chain C is detached from the tooth portion ST of the large-diameter sprocket S1 is reduced. Since the movement of the chain C in the second direction X2 can be restricted by the restricting portion 56, it is possible to omit a mechanism for adjusting the amount of movement of the chain guide 16 when the chain guide 16 is moved in the second direction X (for example, high position adjustment) bolt).

As shown in Fig. 16, when the current derailleur 10 switches the chain C from the small diameter sprocket S2 to the large diameter sprocket S1, the chain C is often slid onto the front end of the tooth portion ST of the large diameter sprocket S1. status. In this case, when the second guide 54 moves excessively in the second direction X2, the chain C moves the larger diameter sprocket S1 toward the second direction X2 side. Therefore, it is possible to fall off from the tooth portion ST of the large-diameter sprocket S1. In the front derailleur 10, the first portion 80 of the restricting portion 56 protrudes toward the second guide 54 side from the second convex portion 82. Therefore, in a state where the chain C slides up to the tip end of the tooth portion ST of the large-diameter sprocket S1, the first portion 80 of the restricting portion 56 restricts the movement of the chain C in the second direction X2. Therefore, the possibility that the chain C is detached from the tooth portion ST of the large-diameter sprocket S1 is reduced.

As shown in Fig. 17, when the chain C is detached toward the second direction X2 side of the large-diameter sprocket S1, the chain C passes through the gap formed between the inner surface 74 of the first guide 52 and the large-diameter sprocket S1. Reverts to the tooth portion ST of the large diameter sprocket S1. At this time, as shown in FIG. 18, the hypothetical structure including the restricting portion 90 extending to the first end edge 62 has a small gap between the first portion 92 of the restricting portion 90 and the large-diameter sprocket S1. The chain C is prevented from returning to the tooth portion ST of the large-diameter sprocket S1. With this hypothetical configuration, the restriction portion 90 may be peeled off from below by the contact of the chain C to be moved toward the tooth portion ST of the large-diameter sprocket S1. As shown in Fig. 17, the front derailleur 10 is disposed so as to be separated from the first end edge 62, so that it is less likely to prevent the chain C from returning to the tooth portion ST of the large-diameter sprocket S1. That is, the possibility that the restriction portion 90 is peeled off is reduced.

The second portion 82 contains a resin. Therefore, when the chain C is wound around the large-diameter sprocket S1, the noise generated when the chain C is vibrated or the like in contact with the second portion 82 can be reduced.

The second portion 82 includes an inclined surface 82A whose amount of protrusion toward the second guide 54 side increases from the proximal end portion 70 side toward the distal end portion 72 side. Therefore, when the chain C is driven in a state of being inclined with respect to the front-rear direction of the bicycle 1, the chain C is suppressed from coming into contact with the second portion 82.

On the inner surface 74 of the first guide plate 52, a second convex portion 78 having a smaller amount of projection D toward the second guide 54 side than the first portion 80 is formed. Therefore, when the chain C slides up to the tooth portion ST of the large-diameter sprocket S1, when the chain C moves further toward the first portion 80 and moves toward the second direction X2, the second convex portion 78 restricts the chain C toward the first 2 direction X2 shift move. Therefore, the chain C is less likely to fall off.

The first inclined surface 76A of the first convex portion 76 has a smaller amount of projection toward the second guide 54 side as it goes from the proximal end portion 70 side toward the distal end portion 72 side. The second inclined surface 76B of the first convex portion 76 has a smaller amount of projection toward the second guide 54 side as it goes from the distal end portion 72 side toward the proximal end portion 70 side. Therefore, when the chain C is driven in a state of being inclined with respect to the front-rear direction of the bicycle 1, the chain C is suppressed from coming into contact with the first convex portion 76.

(Second embodiment)

The front derailleur 100 of the second embodiment will be described with reference to Figs. 19 and 20. The same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof will be omitted.

The front derailleur 100 includes a base member 102, a link mechanism 104, and a chain guide 16. In one example, the front derailleur 100 is further provided with a lower adjustment bolt 18 and a high adjustment bolt 19. The link mechanism 104 includes a first link 106, a second link 108, a biasing member 110, a first shaft portion 112, a second shaft portion 114, a third shaft portion 116, and a fourth shaft portion 118. The chain guide 16 includes a first guide 52, a second guide 54, and a regulating portion 56. The first guide 52 and the second guide 54 of the present embodiment may be formed by bending one metal plate, and may be the first guide 52 and the second guide 54 of different individuals.

The high position adjusting bolt 19 is used when the chain C of the bicycle 1 shown in Fig. 1 is switched from the small diameter sprocket S2 to the large diameter sprocket S1. The position of the chain guide 16 is adjusted. By adjusting the high-position adjusting bolt 19, the stop position of the chain guide 16 in the second direction X2 side when the inner cable W2 shown in FIG. 3 is moved toward the operation portion side is set.

The first end portion 106A of the first link 106 is rotatably connected to the base member 102 via the first shaft portion 112. The second end portion 106B of the first link 106 is rotatably connected to the chain guide 16 via the second shaft portion 114.

The first end portion 108A of the second link 108 is rotatably coupled to the base member 102 via the third shaft portion 116. The second end portion 108B of the second link 108 is rotatably coupled to the chain guide 16 via the fourth shaft portion 118.

The elastic member 110 is disposed between the first link 106 and the chain guide 16. The elastic member 110 is, for example, a coil spring, and is fitted in the second shaft portion 114. The biasing member 110 applies a force toward the first direction X1 to the chain guide 16. The first direction X1 is a state in which the chain guide 10 is attached to the bicycle 1 and the chain guide 16 approaches the direction of the frame F (refer to FIG. 2).

A cable attachment portion 108C for mounting the inner cable W2 (refer to FIG. 3) is provided at the first end portion 108A of the second link 108. The link mechanism 104 rotates around the shaft portions 112, 114, 116, 118 by the respective links 106, 108 when the inner cable W2 is moved toward the operation portion R side by the operation portion R (refer to Fig. 1). The angle formed by the interconnecting links 106 and 108 is changed, and the second end portion 106B of the first link 106 is moved away from the frame F. Thereby letting the first link 106 The chain guide 16 connected to the second end portion 106B moves in the second direction X2 opposite to the first direction X1.

The link mechanism 104 rotates the respective links 106, 108 about the shaft portions 112, 114, 116, 118 by the force of the biasing member 110 when the inner cable W2 moves toward the opposite side of the operating portion. Thereby, the angle formed by the interconnected links 106 and 108 is changed, and the second end 106B of the first link 106 is moved in the direction approaching the frame F. Thereby, the chain guide 16 connected to the second end portion 106B of the first link 106 is moved in the first direction X1. The same effect as that of the first embodiment can be achieved by the front derailleur 100.

(Modification)

The description of the above embodiment is an example of the type adopted by the bicycle front derailleur of the present invention, and is not intended to limit the form thereof. The bicycle front derailleur according to the present invention can adopt, for example, a modification of the above-described embodiment and a combination of at least two modifications that are not contradictory.

A concave portion may be formed in a portion of the inner surface 74 of the first guide 52 that corresponds to the regulating portion 56. In this case, the restricting portion 56 can be fitted into the concave portion formed on the inner surface 74 of the first guide 52.

The method of attaching the first guide 52 to the restricting portion 56 is not limited to the bonding method. For example, it may be attached by a mounting member such as a rivet or a bolt, or may be attached to the through hole or the notch provided in the first guide 52 by a snapping method or the like.

The first portion 80 and the second portion of the restricting portion 56 may also be used. 82 is formed into different individuals. In this case, one of the first portion 80 and the second portion 82 may be formed of a metal. In this case, one of the first portion 80 and the second portion 82 may be integrally formed with the inner surface 74 of the first guide 52. The probability of the first portion 80 being in contact with the chain C compared to the second portion 82 is lower when traveling. Therefore, when one of the first portion 80 and the second portion 82 is formed of a metal and the other is formed of a resin, the first portion 80 is preferably formed of a metal, and the second portion 82 is formed of a resin.

The first portion 80 of the restricting portion 56 may be omitted. In this case, in a state where the chain C is fitted into the tooth portion ST of the large-diameter sprocket S1, the second portion 82 can be prevented from moving the chain C in the second direction X2.

52‧‧‧1st guide

52A‧‧‧outweek

52S‧‧‧ gap

56‧‧‧Restrictions

62‧‧‧1st edge

64‧‧‧2nd edge

66‧‧‧3rd edge

68‧‧‧4th edge

70‧‧‧ base end

72‧‧‧ front end

74‧‧‧ inside

76‧‧‧1st convex

76A‧‧‧1st inclined surface

76B‧‧‧2nd inclined surface

76C‧‧‧Contacts

78‧‧‧2nd convex

80‧‧‧Part 1

82‧‧‧Part 2

82A‧‧‧ sloped surface

Claims (19)

A bicycle front derailleur includes: a base member attachable to a frame of the bicycle; a link mechanism attached to the base member; and a base member attached to the base member via the link mechanism and relative to the bicycle a chain guide that moves the chain by the front sprocket; the chain guide includes: a first guide, a second guide, and a restricting portion; the first guide includes: a first end edge, and the first The end edge of the first link is closer to the second end edge of the link mechanism; and the second guide plate is disposed closer to the frame than the first guide plate in a state where the base member is attached to the frame; The portion includes a resin and is attached to an inner surface of the first guide plate on the second guide plate side, and the restricting portion is disposed apart from the first end edge of the first guide plate. The bicycle front derailleur according to the first aspect of the invention, wherein the restricting portion includes: a first portion; and a second portion closer to the first end edge of the first guide plate than the first portion; The first portion protrudes toward the second guide plate side more than the second portion. The bicycle front derailleur according to claim 2, wherein the first portion and the second portion include the resin, and the first portion and the second portion are integrally formed. The bicycle front derailleur according to claim 2, wherein the second portion includes an inclined surface that follows a base end connected to the link mechanism from the first guide plate. The portion side is directed toward the distal end portion side farthest from the link mechanism, and the amount of protrusion toward the second guide plate side becomes smaller. The bicycle front derailleur according to the second aspect of the invention, wherein the inner surface of the first guide plate includes: between the first end edge of the first guide plate and the restricting portion 2 The first convex portion protruding from the side of the guide plate. The bicycle front derailleur according to claim 5, wherein the first convex portion extends to the first end edge of the first guide. The bicycle front derailleur according to claim 5, wherein a gap is formed between the restricting portion and the first convex portion. The bicycle front derailleur according to claim 5, wherein the second portion protrudes toward the second guide plate side from the first convex portion. The bicycle front derailleur according to claim 5, wherein the first convex portion includes a contact portion that comes into contact with the chain of the bicycle to cause the chain to pass from the large diameter of the front sprocket Moving toward the small front diameter side of the front sprocket. The bicycle front derailleur according to claim 9, wherein the inner surface of the first guide includes a second convex portion, and the second convex portion is disposed closer to the second portion than the contact portion. end The edge side protrudes toward the second guide plate side, and the second convex portion protrudes toward the second guide plate side from the contact portion. The bicycle front derailleur according to claim 10, wherein the first portion protrudes toward the second guide plate side from the second convex portion. The bicycle front derailleur according to claim 1, wherein the restricting portion is adhered to the inner surface of the first guide. The bicycle front derailleur according to claim 12, further comprising an undercoat layer located between the restricting portion and the inner surface of the first guide. The bicycle front derailleur according to claim 13, wherein the undercoat layer is a vulcanized adhesive layer. The bicycle front derailleur according to claim 12, wherein the restricting portion is fitted in a recess formed in the inner surface of the first guide. The bicycle front derailleur according to claim 12, wherein the restricting portion is adhered to the inner surface by insert molding. The bicycle front derailleur according to the first aspect of the invention, wherein the inner circumference of the first guide plate is located further inside than the outer circumference of the first guide plate. For example, the bicycle front derailleur according to the first aspect of the patent application, further comprising a low position adjusting bolt, The low-position adjusting bolt is used to adjust the position of the chain guide when the chain of the bicycle is switched from the large-diameter front sprocket to the small-diameter front sprocket. The bicycle front derailleur according to any one of claims 1 to 18, wherein the resin comprises rubber.