Bicycle and derailleur thereof
By using a four-bar linkage and chain tensioning assembly, the problem of chain slack when the bicycle derailleur is folded is solved, and the chain tension is maintained and the shifting accuracy is achieved when the bicycle is folded.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-18
- Publication Date
- 2026-04-10
AI Technical Summary
Existing derailleurs cannot absorb chain slack when a bicycle is folded, causing the chain to lose tension and affecting the bicycle's folding stability and shifting accuracy.
Employing a four-bar linkage and chain tensioning assembly, including a sprocket, tensioner, and tensioner arm, the four-bar linkage drives the chain tensioning assembly to maintain chain tension when switching between different sprockets and absorb chain slack when the bicycle is folded.
It achieves chain tension when the bicycle is folded, preventing the chain from falling off, improving shifting accuracy, and reducing additional weight.
Smart Images
Figure CN224104242U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a bicycle technical field, concretely relates to a bicycle and chain derailleur thereof. BACKGROUND
[0002] In a bicycle, power is transmitted from a crankset to a freewheel comprising at least one sprocket, thereby transmitting power to a rear wheel. The chain interacts with the teeth on the sprocket in the crankset and also with the sprocket arranged around the hub of the rear wheel of the bicycle in the freewheel, enabling power transmission. In a single-speed bicycle, the freewheel employs one sprocket. When a user operates the pedals, the crankset rotates and moves the chain, thereby causing the sprocket of the freewheel that interacts with it to rotate, which in turn drives the rear wheel to rotate. In a variable-speed bicycle, the freewheel employs multiple sprockets. In order to achieve switching of the chain in sprockets of different diameters, a chain derailleur is usually provided to shift gears.
[0003] The existing chain derailleur usually comprises a base member, a movable member, a chain guide, etc. The movable member is movably connected to the base member through a connecting rod mechanism. Under the action of a control pull wire on a gear shift lever, the chain guide moves laterally relative to the base member to achieve the purpose of gear shifting. The chain guide is movably connected to the movable member, and the chain guide usually comprises a chain guide plate, a tensioning wheel and a guide wheel arranged on the chain guide plate. In the existing chain derailleur, the tensioning wheel and the guide wheel are arranged on the chain guide plate, which results in a small tensioning range for the chain. When the bicycle is folded, the existing chain derailleur cannot absorb the additional slack of the chain, so that the chain cannot maintain tension when the bicycle is folded. SUMMARY
[0004] The utility model aims at overcoming the above-mentioned problems, providing a bicycle chain derailleur, which has a large tensioning range for the chain and can absorb the additional slack of the chain. Not only can the chain maintain tension when moving between different sprockets, but also can maintain tension when the bicycle is folded.
[0005] Another object of the utility model is to provide a bicycle comprising the above-mentioned bicycle chain derailleur.
[0006] The object of the utility model is achieved by the following technical solutions.
[0007] A bicycle chain derailleur comprises a four-bar linkage mechanism and a chain tensioning assembly arranged on the four-bar linkage mechanism. The four-bar linkage mechanism comprises a base member, a movable member and a connecting rod mechanism. The first end of the connecting rod mechanism is connected to the base member, and the second end of the connecting rod mechanism is connected to the first end of the movable member.
[0008] The four-bar linkage mechanism comprises a base member, a movable member and a connecting rod mechanism. The first end of the connecting rod mechanism is connected to the base member, and the second end of the connecting rod mechanism is connected to the first end of the movable member.
[0009] The chain tensioning assembly comprises a chain guide wheel, a tensioning wheel and a tensioning arm; the first end of the tensioning arm is rotationally connected to the second end of the movable member; the tensioning wheel is rotationally arranged at the second end of the tensioning arm; the chain guide wheel is rotationally arranged on the movable member; the rotationally connected part of the tensioning arm and the movable member is provided with a reset assembly; when the chain is switched between different chain wheels or when the bicycle is folded, the chain tensioning assembly keeps the chain tensioned.
[0010] The working principle of the bicycle chain shifter is as follows:
[0011] The variable speed wire drives the chain tensioning assembly and shifts the chain through the four-bar linkage mechanism, so as to switch the chain between different chain wheels and realize gear shifting. The movable member is a moving member, the chain guide wheel moves with the movable member to shift the chain, and the tensioning wheel and the tensioning arm tension the chain. Since the chain guide wheel is arranged on the movable member and the tensioning wheel is arranged on the tensioning arm, the chain tensioning assembly has a large tensioning range for the chain and can absorb the extra slack of the chain. When the bicycle is folded, the chain tensioning assembly keeps the chain tensioned.
[0012] In an embodiment, the movable member comprises an inner guide plate and an outer guide plate, the outer guide plate is fixed to the side of the inner guide plate, and the chain guide wheel is rotationally arranged between the inner guide plate and the outer guide plate; the linkage mechanism is hingedly connected to the first end of the outer guide plate; and the tensioning arm is rotationally connected to the second end of the inner guide plate. In this structure, the movable member is composed of the inner guide plate and the outer guide plate, and the structure is simpler.
[0013] Preferably, the inner guide plate is a flat plate structure, the side of the inner guide plate is divided into an inner side and an outer side, the side close to the bicycle frame is the inner side, and the side close to the outer guide plate is the outer side; the outer guide plate is fixedly connected to the outer side of the inner guide plate by screws; and the tensioning arm is rotationally connected to the second end of the outer side of the inner guide plate. In this structure, the inner guide plate is a flat plate structure, which is easy to process and simple in structure. The inner guide plate and the outer guide plate are connected by screws, which is convenient for installation and disassembly. Moreover, the outer guide plate and the tensioning arm are located on the outer side of the inner guide plate, so that the structure of the bicycle chain shifter is very compact.
[0014] Preferably, the outer guide plate and the tensioning arm are arranged separately from each other. That is, the tensioning arm is only connected to the inner guide plate and does not directly contact the outer guide plate. The inner guide plate is indirectly connected to the tensioning arm through the inner guide plate. The purpose is to simplify the structure of the bicycle chain shifter, so that the tensioning arm does not interfere with the outer guide plate and has a larger rotation range on the inner guide plate, thereby improving the tensioning range of the chain.
[0015] Preferably, the screw is two, the first end of the inner guide plate and the first end of the outer guide plate are fixed by one of the screws, and the middle part of the inner guide plate and the second end of the outer guide plate are fixed by the other screw. In the above structure, the middle part of the inner guide plate and the second end of the outer guide plate are fixed by the other screw, which indicates that the structural length of the outer guide plate is smaller than that of the inner guide plate, and the structure can be simplified. The two screws can make the connection between the inner guide plate and the outer guide plate very stable, and the simplification of the inner guide plate can improve the tensioning range of the chain by the tensioning arm.
[0016] Preferably, a column is arranged on the first end of the tensioning arm, the column is hinged with the second end of the inner guide plate, and the second end of the tensioning arm is arranged in a direction close to the outer side surface of the inner guide plate. The purpose is to ensure that the tensioning wheel and the chain guide wheel can be located on the same plane, so that the chain can be smoothly guided and tensioned on the tensioning wheel and the chain guide wheel, preventing the chain from falling off and improving the stability of the chain work.
[0017] Preferably, the second end of the tensioning arm is provided with two parallel chain guide plates, and the tensioning wheel is arranged between the two chain guide plates. The two chain guide plates can guide the chain to prevent the chain from falling off from the tensioning wheel.
[0018] Preferably, a plurality of open grooves are arranged on the tensioning arm. The purpose is to reduce the weight of the tensioning arm, simplify the structure of the tensioning arm, ensure that the reset component has enough elastic force to tension the chain, and also improve the structural strength of the tensioning arm.
[0019] Preferably, the column and the second end of the inner guide plate are hinged through a hinge shaft, the hinge shaft is provided with an annular groove at an end away from the inner guide plate, the column is provided with a mounting column, the mounting column passes through the annular groove, and the mounting column and the column are connected through threads. In the above structure, the mounting column can be installed on the hinge shaft by arranging the mounting column, and when the tensioning arm rotates, the mounting column can rotate in the annular groove. The annular groove plays a role in limiting the axial position of the mounting column, preventing the column from coming out.
[0020] A bicycle comprises a bicycle frame, a crankset, a freewheel, a chain and a bicycle derailleur; the crankset, the freewheel and the bicycle derailleur are arranged on the bicycle frame, and the chain is connected with the crankset, the freewheel and the bicycle derailleur respectively; when the bicycle is folded, the distance between the axis of the crankset and the axis of the freewheel is reduced, and the bicycle derailleur is used to tension the chain.
[0021] Compared with the prior art, the utility model has the following beneficial effects:
[0022] 1. The bicycle derailleur in the utility model, since the chain guide wheel is arranged on the movable component, the tension wheel is arranged on the tension arm, the distance between the chain guide wheel and the tension wheel can be changed, so that the chain tension assembly has a large tension range for the chain and can absorb the extra slack of the chain; not only can the chain maintain tension when switching and moving between different chain wheels, but also can maintain tension when the bicycle is folded, the chain is still in a tension state after the rear wheel is folded, and the chain does not fall off.
[0023] 2. The bicycle derailleur in the utility model, when the bicycle is folded, one bicycle derailleur is used to absorb the slack of the chain, and the chain moves between different chain wheels when shifting, so that an additional chain tensioner is not needed, and unnecessary bicycle weight caused by the additional chain tensioner is avoided.
[0024] 3. The bicycle derailleur in the utility model, in the process of shifting, the chain guide wheel and the tension wheel move at the same time, so that the speed change is more accurate. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 It is a partial structure schematic view of the bicycle in the utility model in a non-folded state.
[0026] Figure 2 It is a partial structure schematic view of the bicycle in the utility model in a folded state.
[0027] Figure 3 It is a front view of the bicycle derailleur in the utility model.
[0028] Figure 4 It is a front view of the bicycle derailleur in the utility model in another state.
[0029] Figure 5 It is a three-dimensional structure schematic view of the bicycle derailleur in the utility model.
[0030] Figure 6 It is a three-dimensional structure schematic view of the bicycle derailleur in the utility model in another direction view.
[0031] Figure 7 It is a right view of the bicycle derailleur in the utility model.
[0032] Figure 8 It is a three-dimensional structure schematic view of the movable component and part of the chain tension assembly in the utility model.
[0033] Figure 9 It is a top view of the movable component and part of the chain tension assembly in the utility model.
[0034] Figure 10The utility model discloses a three-dimensional structure schematic diagram of the inner guide plate, the tensioning wheel and the tensioning arm in the utility model.
[0035] Figure 11 The utility model discloses a three-dimensional structure schematic diagram of the inner guide plate, the mounting column, the hinged axle and the reset component in the utility model. DETAILED DESCRIPTION
[0036] In order to make the technical personnel of the prior art well understand the technical scheme of the utility model, the utility model will be further described below in conjunction with the embodiment and the drawing, but the embodiment of the utility model is not limited to this.
[0037] Referring to Figures 1-2 The embodiment discloses a bicycle, which comprises a bicycle frame 1, a crankset 2, a freewheel 3, a chain 4 and a bicycle derailleur 100; the crankset 2, the freewheel 3 and the bicycle derailleur 100 are arranged on the bicycle frame 1, and the chain 4 is connected with the crankset 2, the freewheel 3 and the bicycle derailleur 100 respectively; when the bicycle is folded, the distance between the axis of the crankset 2 and the axis of the freewheel 3 is reduced, that is, the distance between the axis of the crankset 2 and the axis of the freewheel 3 when the bicycle is unfolded is greater than the distance between the axis of the crankset 2 and the axis of the freewheel 3 when the bicycle is folded, and the bicycle derailleur 100 is used for tensioning the chain 4. The axis of the crankset 2 is the axis of a sprocket on the crankset 2, and the freewheel 3 can be composed of one sprocket or a plurality of sprockets.
[0038] Referring to Figures 1-7 The bicycle derailleur 100 comprises a four-bar linkage mechanism 7 and a chain tensioning assembly arranged on the four-bar linkage mechanism 7. The four-bar linkage mechanism 7 can drive the chain tensioning assembly to move, thereby achieving the functions of undulating the chain 4 and tensioning the chain 4.
[0039] Referring to Figures 1-7 The four-bar linkage mechanism 7 comprises a base member 5, a movable member 6 and a linkage mechanism 7; the base member 5 is installed on the bicycle frame 1; the first end of the linkage mechanism 7 is connected with the base member 5, and the second end of the linkage mechanism 7 is connected with the first end of the movable member 6.
[0040] Referring to Figures 2-11, the chain tensioning assembly comprises a chain guide wheel 8, a tensioning wheel 9 and a tensioning arm 10; the first end of the tensioning arm 10 is rotatably connected to the second end of the movable member 6; the tensioning wheel 9 is rotatably arranged at the second end of the tensioning arm 10; the chain guide wheel 8 is rotatably arranged on the movable member 6; and the rotatable connection between the tensioning arm 10 and the movable member 6 is provided with a reset assembly. When the bicycle is shifting or folding, the elastic force of the reset assembly makes the tensioning arm 10 swing back to tension the chain 4. That is, when the chain 4 is switching between different sprockets or when the bicycle is folding, the chain tensioning assembly keeps the chain tensioned.
[0041] Referring to Figures 2-11 , the movable member 6 comprises an inner guide plate 61 and an outer guide plate 62, the outer guide plate 62 is fixed on the side of the inner guide plate 61, and the chain guide wheel 8 is rotatably arranged between the inner guide plate 61 and the outer guide plate 62; the connecting rod mechanism 7 is hingedly connected to the first end of the outer guide plate 62; and the tensioning arm 10 is rotatably connected to the second end of the inner guide plate 61. In the above structure, the movable member 6 is composed of the inner guide plate 61 and the outer guide plate 62, and the structure is simpler; the first end of the outer guide plate 62 constitutes the first end of the movable member 6, and the second end of the inner guide plate 61 constitutes the second end of the movable member 6.
[0042] Referring to Figures 2-11 , the inner guide plate 61 is a flat plate structure, the side of the inner guide plate 61 is divided into an inner side and an outer side, the side close to the bicycle frame 1 is the inner side, and the side close to the outer guide plate 62 is the outer side; the outer guide plate 62 is fixedly connected to the outer side of the inner guide plate 61 by a screw 11; and the tensioning arm 10 is rotatably connected to the second end of the outer side of the inner guide plate 61. In the above structure, the inner guide plate 61 is a flat plate structure, which is easy to process and simple in structure; the inner guide plate 61 and the outer guide plate 62 are connected by the screw 11, which is convenient for installation and disassembly; and the outer guide plate 62 and the tensioning arm 10 are located on the side of the outer side of the inner guide plate 61, so that the structure of the bicycle derailleur 100 becomes very compact.
[0043] Referring to Figures 1-11 , the outer guide plate 62 and the tensioning arm 10 are arranged separately from each other. That is, the tensioning arm 10 is only connected to the inner guide plate 61 and does not directly contact and connect with the outer guide plate 62; the outer guide plate 62 and the tensioning arm 10 are separated; and the inner guide plate 61 is indirectly connected to the tensioning arm 10 through the inner guide plate 61; the purpose is to simplify the structure of the bicycle derailleur 100, so that the tensioning arm 10 does not interfere with the outer guide plate 62, and the tensioning arm 10 has a larger rotation range on the inner guide plate 61, thereby improving the tensioning range of the chain 4.
[0044] Referring to Figures 2-11Said screw 11 is two, one of which is used to fix the first end of the inner guide plate 61 and the first end of the outer guide plate 62, and the other is used to fix the middle part of the inner guide plate 61 and the second end of the outer guide plate 62. In the above structure, the middle part of the inner guide plate 61 and the second end of the outer guide plate 62 are fixed by the other screw 11, which indicates that the structural length of the outer guide plate 62 is smaller than that of the inner guide plate 61, and the structure can be simplified. The two screws 11 can make the connection between the inner guide plate 61 and the outer guide plate 62 very stable, and the simplification of the inner guide plate 61 can improve the tensioning range of the tensioning arm 10 to the chain 4.
[0045] Referring to Figures 2-11 Said chain guide wheel 8 is arranged between the middle part of the outer guide plate 62 and the middle part of the inner guide plate 61, the first end of the outer guide plate 62 is provided with a mounting protrusion 621, and the second end of the outer guide plate 62 is provided with a positioning sleeve 622. The mounting protrusion 621 and the positioning sleeve 622 are connected to the inner guide plate 61 by two screws 11 respectively. The purpose is to ensure that there is space between the inner guide plate 61 and the outer guide plate 62, which is convenient for the installation of the chain guide wheel 8 and the connection of the screw 11. The mounting protrusion 621 can also prevent the chain 4 from falling off the chain guide wheel 8.
[0046] Referring to Figures 2-11 The first end of the tensioning arm 10 is provided with a column 12, the column 12 is provided with an inner cavity, the column 12 is hinged to the second end of the inner guide plate 61, and the second end of the tensioning arm 10 is arranged in a direction close to the outer side surface of the inner guide plate 61. The purpose is to ensure that the tensioning wheel 9 and the chain guide wheel 8 can be located in the same plane, so that the chain 4 can be smoothly guided and tensioned on the tensioning wheel 9 and the chain guide wheel 8, preventing the chain 4 from falling off and improving the stability of the chain 4 in work.
[0047] Referring to Figures 2-11 The second end of the tensioning arm 10 is provided with two parallel chain guide plates 13, and the tensioning wheel 9 is arranged between the two chain guide plates 13. The two chain guide plates 13 can guide the chain 4 to prevent the chain 4 from falling off the tensioning wheel 9.
[0048] Referring to Figures 2-11 A plurality of open grooves 14 are arranged on the tensioning arm 10. The purpose is to reduce the weight of the tensioning arm 10, simplify the structure of the tensioning arm 10, ensure that the reset assembly has enough elastic force to tension the chain 4, and also improve the structural strength of the tensioning arm 10.
[0049] Referring to Figures 2-11, the second end of the inner guide plate 61 is hinged with the column 12 through a hinge shaft 15; the hinge shaft 15 is provided with an annular groove 16 on the end far from the inner guide plate 61, the column 12 is provided with a mounting column 17, the mounting column 17 passes through the annular groove 16, and the mounting column 17 is connected with the column 12 through screw connection. In the above structure, the mounting column 17 is arranged to mount the column 12 on the hinge shaft 15, when the tensioning arm 10 rotates, the mounting column 17 can rotate in the annular groove 16, the annular groove 16 plays a role of axial limiting for the mounting column 17, and the column 12 is prevented from being pulled out.
[0050] Referring to Figures 2-11 , the reset assembly is a torsion spring 18, which is sleeved on the hinge shaft 15 and located in the inner cavity, one end of the torsion spring 18 acts on the second end of the inner guide plate 61, and the other end acts on the column 12. The elastic force of the torsion spring 18 promotes the rotation of the tensioning arm 10, so that the tensioning wheel 9 tightens the chain 4.
[0051] Referring to Figures 2-11 , the side surface of the column 12 is provided with a limiting protrusion 19, and the outer side surface of the inner guide plate 61 is provided with a limiting column 20, the limiting protrusion 19 and the limiting column 20 can prevent the tensioning arm 10 from colliding with the four-bar linkage mechanism 7 due to excessive elastic force of the torsion spring 18, and play a role of safety limiting.
[0052] Referring to Figures 1-11 , the linkage mechanism 7 includes a first connecting rod 71 and a second connecting rod 72, the first end of the first connecting rod 71 is hinged with the base member 5, and the second end of the first connecting rod 71 is hinged with the first end of the outer guide plate 62; the first end of the second connecting rod 72 is hinged with the base member 5, and the second end of the second connecting rod 72 is hinged with the first end of the outer guide plate 62; the first connecting rod 71 and the second connecting rod 72 are hinged with the base member 5 at different positions, and the first connecting rod 71 and the second connecting rod 72 are hinged with the first end of the outer guide plate 62 at different positions.
[0053] Referring to , the working principle of the above bicycle derailleur 100 is as follows:
[0054] The shift wire drives the chain tensioning assembly and moves the chain 4 through the four-bar linkage mechanism 7, so that the chain 4 moves between different sprockets to realize the gear shifting process. The movable member 6 is a moving member, the chain guide wheel 8 moves with the movable member 6, thereby moving the chain 4, the tensioning wheel 9 and the tensioning arm 10 tension the chain 4. Since the chain guide wheel 8 is arranged on the movable member 6, and the tensioning wheel 9 is arranged on the tensioning arm 10, the chain tensioning assembly can tension the chain 4 in a large range, and can absorb the extra slack of the chain 4, and the chain tensioning assembly can keep the tension of the chain 4 when the bicycle is folded.
[0055] The above is the preferred embodiment of the present application, but the embodiment of the present application is not limited by the above, and any change, modification, replacement, combination, simplification made without departing from the spirit and principles of the present application should be an equivalent replacement method, which is included in the protection scope of the present application.
Claims
1. A bicycle derailleur, characterized in that, It includes a four-bar linkage and a chain tensioning assembly disposed on the four-bar linkage; wherein, The four-bar linkage includes a base component, a movable component, and a linkage mechanism; the first end of the linkage mechanism is connected to the base component, and the second end of the linkage mechanism is connected to the first end of the movable component. The chain tensioning assembly includes a guide sprocket, a tensioning wheel, and a tensioning arm; the first end of the tensioning arm is rotatably connected to the second end of the movable component; the tensioning wheel is rotatably disposed at the second end of the tensioning arm; the guide sprocket is rotatably disposed on the movable component, and a reset assembly is provided at the rotatable connection between the tensioning arm and the movable component.
2. A bicycle derailleur according to claim 1, characterized in that, The movable component includes an inner guide plate and an outer guide plate. The outer guide plate is fixed to the side of the inner guide plate. The guide sprocket is rotatably disposed between the inner guide plate and the outer guide plate. The linkage mechanism is hinged to the first end of the outer guide plate. The tensioning arm is rotatably connected to the second end of the inner guide plate.
3. A bicycle derailleur according to claim 2, characterized in that, The inner guide plate is a flat plate structure. The sides of the inner guide plate are divided into inner and outer sides. The side closer to the bicycle frame is the inner side, and the side closer to the outer guide plate is the outer side. The outer guide plate and the outer side of the inner guide plate are fixedly connected by screws. The tensioning arm is rotatably connected to the second end of the outer side of the inner guide plate.
4. A bicycle derailleur according to claim 2, characterized in that, The outer guide plate and the tensioning arm are separately configured.
5. A bicycle derailleur according to claim 3, characterized in that, There are two screws. The first end of the inner guide plate is fixed to the first end of the outer guide plate by one screw, and the middle part of the inner guide plate is fixed to the second end of the outer guide plate by the other screw.
6. A bicycle derailleur according to claim 2, characterized in that, The first end of the tensioning arm is provided with a column, which is hinged to the second end of the inner guide plate. The second end of the tensioning arm is inclined toward the outer side of the inner guide plate.
7. A bicycle derailleur according to claim 1, characterized in that, The second end of the tensioning arm is provided with two parallel guide discs, and the tensioning wheel is disposed between the two guide discs.
8. A bicycle derailleur according to claim 1, characterized in that, The tensioning arm is provided with multiple opening slots.
9. A bicycle derailleur according to claim 2, characterized in that, The column body is hinged to the second end of the inner guide plate via a hinge shaft; the hinge shaft has an annular groove at the end away from the inner guide plate, the column body has a mounting post, the mounting post passes through the annular groove, and the mounting post is threadedly connected to the column body.
10. A bicycle, characterized in that, The bicycle includes a bicycle frame, a crank assembly, a freewheel, a chain, and a bicycle derailleur as described in any one of claims 1-9; the crank assembly, the freewheel, and the bicycle derailleur are all mounted on the bicycle frame, and the chain is connected to the crank assembly, the freewheel, and the bicycle derailleur respectively; when the bicycle is folded, the distance between the axis of the crank assembly and the axis of the freewheel decreases, and the bicycle derailleur is used to tension the chain.