Twelve-speed rear derailleur of bicycle

Abstract

The utility model discloses a bicycle twelve-speed rear derailleur which comprises a fixing piece, an upper pivot and a lower pivot, the fixing piece is in an inverted Y shape, limiting screws are arranged at one ends of the front faces of two branches of the fixing piece in a sleeved mode, the bottoms of the two branches of the fixing piece are hinged to one end of the front face of the upper pivot, and the lower pivot is hinged to one end of the front face of the lower pivot. A limiting screw is hinged to one end of the back face of the upper pivot and used for limiting the rotation angle of the upper pivot by abutting against the upper pivot, a connecting shaft is hinged to one end of the back face of the upper pivot, and the bottom of the connecting shaft is hinged to the top of the lower pivot. When the twelve-speed split finger poking brake is poked, the bending radian of the upper pivot pulled by a cable is larger, and the limiting screw is installed in front of the fixing piece, so that it is guaranteed that deformation rotation is smoother when the spring is broken and the like.

Description

Technical Field

[0001] The utility model relates to the field of bicycle speed changing devices, in particular to a twelve-speed rear transmission for a bicycle. Background Art

[0002] As one of the popular means of transportation among the general public, the shifter and the rear derailleur are the two most important components of the gear bicycle. The two components must match each other to make the acceleration during riding smoother and safer. At present, a twelve-speed split shifter has been designed in the market. When riding a bicycle with a twelve-speed split shifter, the shifter is moved to retract the cable, and the rear accelerator is stretched and deformed under the action of the pulling of the cable and the elastic force of the internal spring. Since the rear derailleur does not have a twelve-digit adjustment, the stretching and deformation of the rear derailleur cannot keep up with the pulling of the cable. The cable cannot withstand the pulling force of the shifter and breaks, the spring collapses, and the rear derailleur is severely deformed and cannot return to its original position, resulting in the derailleur being unable to operate normally, which poses a safety hazard to the rider when changing speeds. Therefore, a twelve-speed rear derailleur for a bicycle is provided. Utility Model Content

[0003] The utility model aims to provide a twelve-speed rear transmission for a bicycle to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: A twelve-speed rear transmission for a bicycle. To achieve the above-mentioned purpose, the utility model provides the following technical solutions: A twelve-speed rear transmission for a bicycle, comprising a fixing part, an upper pivot and a lower pivot, the shape of the fixing part being set to an inverted "Y" shape, one end of the front side of the two branches of the fixing part being sleeved with a limit screw, the bottom of the two branches of the fixing part being hinged to one end of the front side of the upper pivot, the limit screw being used to limit the rotation angle of the upper pivot by resisting the upper pivot, a connecting shaft being hinged to one end of the back side of the upper pivot, and the bottom of the connecting shaft being hinged to the top of the lower pivot.

[0005] Preferably, the upper pivot includes an upper jaw, a lower jaw and a strong spring, wherein the strong spring is arranged between the upper jaw and the lower jaw, one end of the strong spring is sleeved with a side branch of the fixing member, and the other end of the strong spring is sleeved with the inner wall of the upper jaw.

[0006] Preferably, the top of the upper jaw is hinged to one side branch of the fixing member, the middle of the top of the lower jaw is hinged to the other side branch of the fixing member, and the bottom ends of the upper jaw and the lower jaw are respectively hinged to the two sides of the top of the connecting shaft.

[0007] Preferably, the lower pivot comprises a pulley guide frame, and the top end of the pulley guide frame is rotatably connected to the bottom end of the connecting shaft.

[0008] Preferably, the lower pivot further comprises:

[0009] A guide sprocket wheel, the guide sprocket wheel is rotatably sleeved on the top of the pulley guide frame near the front end;

[0010] The tension wheel is rotatably sleeved on one end of the pulley guide frame close to the back side.

[0011] Preferably, a threaded structure for fixing the frame is provided on the back side of the top end of the fixing member, and a wire hole is provided on the front side of the top end of the fixing member.

[0012] Preferably, the front section of the lower jaw is provided with a wire tightening device.

[0013] Technical effects and advantages of the utility model:

[0014] Utilizing brand-new component structure technology with large stroke to support twelve-speed shifting, the upper pivot adopts a combination of upper jaw and lower jaw, so that when the twelve-speed split finger paddle shifter is turned, the upper pivot is pulled by the cable with a larger bending arc, which makes it freer to adjust the guide of the bicycle chain for linkage with the lower pivot, and the guiding gear is also larger. By installing a limit screw in front of the fixing, the spring tension and the degree of deformation of the upper pivot can be freely adjusted, ensuring the safety of the upper pivot after high-intensity deformation and preventing spring collapse. The entire upper pivot is hinged through a rotating shaft, which makes the rotation smoother during deformation, making riding safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an overall intuitive structural schematic diagram of the utility model.

[0016] Figure 2 It is a front view of the upper pivot structure of the utility model.

[0017] Figure 3 It is a structural schematic diagram of the lower pivot part of the utility model.

[0018] Figure 4 It is a top view of the overall structure of the utility model.

[0019] Figure 5 It is a side view of the overall structure of the utility model.

[0020] In the figure: 1. fixing part; 101. limit screw; 102. threaded structure; 103. tensioning device; 104. wire guide hole; 2. upper pivot; 201. upper jaw; 202. lower jaw; 203. strong spring; 3. lower pivot; 301. pulley guide frame; 302. guide chain wheel; 303. tension wheel; 4. connecting shaft. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] The utility model provides Figure 1-5 A twelve-speed bicycle rear transmission shown in the figure includes a fixing member 1, an upper pivot 2 and a lower pivot 3. The shape of the fixing member 1 is set to be an inverted "Y" shape. One end of the front side of the two branches of the fixing member 1 is sleeved with a limit screw 101. The bottom of the two branches of the fixing member 1 is hinged to one end of the front side of the upper pivot 2. The limit screw 101 is used to limit the rotation angle of the upper pivot 2 by supporting it. A connecting shaft 4 is hinged at one end of the back side of the upper pivot 2. The bottom of the connecting shaft 4 is hinged to the top of the lower pivot 3.

[0023] It should be noted that the designed bicycle 12-speed rear shift reference model RD-TY3000, its fixing part 1, upper pivot 2 and lower pivot 3 are made of aluminum alloy, which is strong and durable, and provides a solid foundation for stretching and deformation during use. The fixing part 1 is in the shape of Y, and its special shape can be simultaneously hinged with the upper jaw 201 and the lower jaw 202, and the three are connected to form the entire upper pivot 2. The design of the upper jaw 201 and the lower jaw 202 presents a shaped part structure, and this new part can support the adjustment of the gear position of the 12-speed split finger paddle.

[0024] Specifically, the upper pivot 2 includes an upper jaw 201, a lower jaw 202 and a strong spring 203, the strong spring 203 is arranged between the upper jaw 201 and the lower jaw 202, one end of the strong spring 203 is sleeved with a side branch of the fixing member 1, the other end of the strong spring 203 is sleeved with the inner wall of the upper jaw 201, the top of the upper jaw 201 is hinged with a side branch of the fixing member 1, the middle of the top of the lower jaw 202 is hinged with the other side branch of the fixing member 1, the bottom ends of the upper jaw 201 and the lower jaw 202 are respectively hinged with the two sides of the top of the connecting shaft 4, and the lower pivot 3 also includes: a guide chain wheel 302, the guide chain wheel 302 is rotatably sleeved on the top of the pulley guide frame 301 near the front end; a tension wheel 303, the tension wheel 303 is rotatably sleeved on the end of the pulley guide frame 301 near the back end.

[0025] It should be noted that the tension wheel 303 and the pulley guide frame 301 are made of nylon wear-resistant resin guide wheels, which have good wear resistance and can make the chain rotate more smoothly. The tension wheel 303 gives a certain tension to the lower part of the chain when riding, which plays the function of tightening the chain. The guide wheel 302 guides the moving chain to the correct gear position of the flywheel. The two guide wheels rotate the chain in succession to help the transmission achieve precise speed changes. The pulley guide frame 301 uses an aluminum alloy body, which fixes the guide wheel on the same horizontal plane. When the guide wheel is working, it protects the chain from being offset. While protecting the chain, it also protects the tension wheel 303 and the pulley guide frame 301 from being affected and worn by the outside world.

[0026] Specifically, a frame fixing thread structure 102 is provided on the back of the top of the fixing member 1 , a wire guide hole 104 is provided on the front of the top of the fixing member 1 , and a wire tightening device 103 is provided on the front section of the lower jaw 202 .

[0027] It should be noted that the designed spring adopts B tension spring, which is used to realize fast and convenient installation and disassembly of the wheel set. Its strong spring 203 has high tension and good elasticity, can support the adjustment of the twelve-speed gear, support rapid rebound when returning to the gear, and realize precise gear shifting. The fixing part 1 is provided with a limiting screw 101, which acts on adjusting the stretching angle and the stretching length of the spring to ensure the maximum stretching length of the strong spring 203 and the overall safety of the rear transmission.

[0028] Working principle of this utility model:

[0029] The rear derailleur is fixedly installed at the tail hook of the variable speed device at the rear wheel of the bicycle by screws, and the cable is led out from the twelve-speed split finger shifter, and is led to the rear derailleur position through the lead-in route of the bicycle body, and the cable passes through the lead-in hole 104. The cable head is fastened to the tensioning device 103 by screws, and the rear derailleur is installed. When riding, the rider shifts the twelve-speed split finger shifter, and each shifting causes the cable to be tightened by a certain distance. The tightening of the cable causes the lower jaw 202 to be subjected to a pulling force along the direction of the cable. Under the action of the rotating shaft, the lower jaw 202 rotates along the direction of the cable, thereby driving the upper jaw 201 to be stretched and deformed, and the upper pivot 2 links the entire lower pivot 3 to start stretching and deforming. The linkage between the upper jaw 201 and the lower jaw 202 allows the overall stretching deformation to meet the twelve-speed requirement, and the lower pivot 3 stretches and approaches the flywheel, and the chain is guided into the corresponding twelve-speed gear position through the guide sprocket 302. The rear derailleur is in a static deformed state under the action of the twelve-speed cable tension and the tension of the strong spring 203, completing the entire speed change process.

[0030] Finally, it should be noted that the above is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A 12-speed rear transmission for a bicycle, characterized in that: The invention comprises a fixing member (1), an upper pivot (2) and a lower pivot (3), wherein the fixing member (1) is shaped as an inverted "Y" shape, and a limiting screw (101) is sleeved on one end of the front face of two branches of the fixing member (1), and the bottom of the two branches of the fixing member (1) is hinged to one end of the front face of the upper pivot (2), and the limiting screw (101) is used to limit the rotation angle of the upper pivot (2) by resisting the upper pivot (2), and a connecting shaft (4) is hinged on one end of the back face of the upper pivot (2), and the bottom of the connecting shaft (4) is hinged to the top of the lower pivot (3).

2. A 12-speed bicycle rear derailleur according to claim 1, characterized in that: The upper pivot (2) comprises an upper jaw (201), a lower jaw (202) and a strong spring (203); the strong spring (203) is arranged between the upper jaw (201) and the lower jaw (202); one end of the strong spring (203) is sleeved with a branch on one side of the fixing member (1); and the other end of the strong spring (203) is sleeved with the inner wall of the upper jaw (201).

3. A 12-speed bicycle rear derailleur according to claim 2, characterized in that: The top of the upper jaw (201) is hinged to one side branch of the fixing member (1), the middle of the top of the lower jaw (202) is hinged to the other side branch of the fixing member (1), and the bottom ends of the upper jaw (201) and the lower jaw (202) are respectively hinged to the two sides of the top of the connecting shaft (4).

4. A 12-speed bicycle rear derailleur according to claim 1, characterized in that: The lower pivot (3) comprises a pulley guide frame (301), and the top end of the pulley guide frame (301) is rotatably connected to the bottom end of the connecting shaft (4).

5. A 12-speed bicycle rear derailleur according to claim 4, characterized in that: The lower pivot (3) further comprises: A guide sprocket (302), the guide sprocket (302) is rotatably sleeved on the top of the pulley guide frame (301) near the front end; The tension wheel (303) is rotatably sleeved on an end of the pulley guide frame (301) close to the back side.

6. A 12-speed bicycle rear derailleur according to claim 1, characterized in that: A frame fixing thread structure (102) is provided on the back side of the top end of the fixing member (1), and a wire lead hole (104) is provided on the front side of the top end of the fixing member (1).

7. A 12-speed bicycle rear derailleur according to claim 3, characterized in that: The front section of the lower jaw (202) is provided with a wire tightening device (103).

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