Automatic expansion type bicycle speed change device

Abstract

The utility model relates to an automatic expansion type bicycle speed change device which comprises a bicycle frame, a front axle, a rear axle, a front fluted disc, a chain and a speed change mechanism. The front axle and the rear axle are both rotationally connected to the interior of the frame, the front fluted disc is arranged on the outer side of the front axle in a sleeving mode, and the chain is in transmission connection to the outer side of the front fluted disc. According to the automatic expansion type bicycle speed changing device, through driving of the transmission mechanism, the telescopic rod is driven to move up and down, the telescopic rod drives the arc-shaped supporting piece and the semi-arc-shaped block which are connected with the telescopic rod to move in the moving process, so that the distance between the arc-shaped supporting piece and the ratchet wheel is adjusted, and therefore the outer diameter of the whole speed adjusting device is adjusted; the circular chain disc is formed by combining the arc-shaped supporting pieces, namely when the distance between the arc-shaped supporting pieces and the ratchet wheel is larger, the outer diameter of the whole chain disc is increased, otherwise, the diameter of the chain disc is reduced, and the problem that an existing bicycle speed changing system is usually composed of a plurality of transmission gears of different sizes is effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of bicycle speed change, in particular to an automatic expansion type bicycle speed change device. Background Art

[0002] Bicycle gearshifting refers to the mechanism of adjusting riding resistance and speed by changing the transmission gear ratio during riding. This process can be achieved in different ways, the most common of which is the use of a derailleur or transmission gear system;

[0003] The bicycle transmission system usually includes a front derailleur and a rear derailleur. The front derailleur controls the number of teeth on the front sprocket, while the rear derailleur controls the transmission gear set of the rear wheel. By adjusting the front and rear derailleurs, the rider can change the transmission gear ratio to adapt to different road conditions and riding needs;

[0004] However, the current bicycle speed change system usually adopts a plurality of transmission gears of different sizes. When adjusting the speed, the chain needs to be moved to the corresponding sprocket. Since there is a certain gap between two adjacent transmission gears, the chain is prone to get stuck or fall off during the speed adjustment process. Therefore, an automatic expansion bicycle speed change device is proposed to solve the above technical problems. Utility Model Content

[0005] In view of the shortcomings of the prior art, the utility model provides an automatic expansion type bicycle speed change device, which solves the problem that the current bicycle speed change system usually adopts a plurality of transmission gears of different sizes.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: an automatic expansion type bicycle speed change device, comprising a frame, a front axle, a rear axle, a front sprocket, a chain and a speed change mechanism;

[0007] The front axle and the rear axle are both rotatably connected to the inside of the frame, the front sprocket is sleeved on the outside of the front axle, the chain transmission is connected to the outside of the front sprocket, and the speed change mechanism is installed on the outside of the rear axle;

[0008] The speed change mechanism is connected to the speed change mechanism through a chain;

[0009] The speed change mechanism comprises a rotating wheel, which is sleeved on the outside of the rear axle, a groove is provided on the outside of the rotating wheel, and a stop pawl is rotatably connected inside the groove, and the stop pawl is connected to the inner wall of the groove through at least one torsion spring;

[0010] A ratchet is sleeved on the outer side of the rotating wheel, corresponding to the locking claw, and a connecting groove for the locking claw to be embedded is opened on the inner side of the ratchet;

[0011] At least two telescopic rods are slidably connected inside the ratchet wheel, an arc-shaped support piece is installed at one end of the telescopic rod away from the rotating wheel, a semi-arc-shaped block is rotatably connected inside the arc-shaped support piece, and the semi-arc-shaped block is connected to the arc-shaped support piece through a torsion spring;

[0012] The telescopic rod includes a vertical portion and a horizontal portion, a slide groove is provided inside the ratchet wheel for the vertical portion to slide up and down, and a square opening is provided on the front side of the ratchet wheel corresponding to the horizontal portion for the horizontal portion to pass through and move up and down, and the square opening is connected to the slide groove;

[0013] A transmission mechanism is arranged on the outer side of the ratchet wheel for adjusting the distance between the arc-shaped support piece and the ratchet wheel.

[0014] Furthermore, at least two of the semi-arc blocks are connected to the chain transmission.

[0015] Furthermore, the front cross-section of the connecting groove is in the shape of a triangle.

[0016] Furthermore, the transmission mechanism includes a shifting gear, a fixing plate, a waterproof shell, a fixed-axis motor and a battery; the shifting gear is sleeved on the outside of the rear axle, the waterproof shell is installed on the ratchet through the fixing plate, the fixed-axis motor and the battery are both arranged on the outside of the waterproof shell, and the fixed-axis motor is electrically connected to the battery.

[0017] Furthermore, a transmission gear is sleeved on the output end of the fixed-axis motor, and the transmission gear is transmission-connected with a shift gear to drive the shift gear to rotate.

[0018] Furthermore, a plurality of arc-shaped grooves are provided inside the first shift gear, into which a plurality of lateral parts are inserted respectively.

[0019] Furthermore, a shift switch connected to the fixed-axis motor signal is arranged on the frame.

[0020] Furthermore, a support rod is rotatably connected to the frame, a compression spring is installed between the side of the support rod opposite to the frame, a tensioning wheel is rotatably connected to the bottom end of the support rod, and the tensioning wheel is in contact with the inner side of the chain.

[0021] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0022] The automatic expansion bicycle speed change device is driven by a transmission mechanism to drive the telescopic rod to move up and down, and the telescopic rod drives the arc-shaped support piece and the semi-arc-shaped block connected thereto to move during the movement, so as to adjust the distance between the arc-shaped support piece and the ratchet wheel, thereby adjusting the outer diameter of the entire speed control device. A circular chain plate is formed by combining a plurality of arc-shaped support pieces, that is, when the distance between the arc-shaped support piece and the ratchet wheel is larger, the outer diameter of the entire chain plate increases accordingly, and vice versa, the diameter of the chain plate decreases, which effectively solves the problem that the current bicycle speed change system usually adopts a plurality of transmission gears of different sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the utility model;

[0024] Figure 2 It is a schematic diagram of the speed change mechanism of the utility model;

[0025] Figure 3 It is a rear view schematic diagram of the speed change mechanism of the utility model;

[0026] Figure 4 This is a schematic diagram of the connection structure between the arc-shaped support piece and the semi-arc-shaped block of the utility model;

[0027] Figure 5 This is a schematic diagram of the connection structure between the rotating wheel and the locking claw of the utility model;

[0028] Figure 6 This is a schematic diagram of the overall structure of the speed change mechanism of the utility model;

[0029] Figure 7 This is a schematic diagram of the internal structure of the waterproof shell of the utility model.

[0030] In the figure: 1. frame; 2. front axle; 3. rear axle; 4. front sprocket; 5. chain; 6. speed change mechanism; 601. rotating wheel; 602. locking pawl; 603. ratchet; 604. connecting groove; 605. telescopic rod; 6051. vertical part; 6052. transverse part; 606. arc-shaped support piece; 607. semi-arc-shaped block; 608. 1 shifting gear; 609. fixing plate; 610. waterproof shell; 611. fixed axis motor; 612. battery; 613. transmission gear; 7. support rod; 8. compression spring; 9. tension wheel. DETAILED DESCRIPTION

[0031] 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.

[0032] See also Figure 1 An automatic expansion type bicycle speed change device in this embodiment includes a frame 1, a front axle 2, a rear axle 3, a front sprocket 4, a chain 5 and a speed change mechanism 6; the front axle 2 and the rear axle 3 are both rotatably connected to the inside of the frame 1, the front sprocket 4 is sleeved on the outside of the front axle 2, the chain 5 is transmission-connected to the outside of the front sprocket 4, and the speed change mechanism 6 is installed on the outside of the rear axle 3; and the speed change mechanism 6 is transmission-connected to the speed change mechanism 6 through the chain 5.

[0033] In actual use, the outer diameter of the entire transmission mechanism 6 is adjusted through the cooperation between the various components inside the transmission mechanism 6 to adapt to different road conditions and riding requirements, and the chain 5 is driven by the rotation of the front sprocket 4, thereby driving the transmission mechanism 6 and the rear axle 3 to rotate.

[0034] See also Figure 2-7 , in order to adapt to different road conditions and riding requirements, the speed change mechanism 6 in this example is connected to the speed change mechanism 6 through a chain 5;

[0035] The speed change mechanism 6 includes a rotating wheel 601, which is sleeved on the outer side of the rear axle 3. A groove is formed on the outer side of the rotating wheel 601, and a stopper 602 is rotatably connected inside the groove. The stopper 602 is connected to the inner wall of the groove through at least one torsion spring.

[0036] A ratchet 603 is sleeved on the outer side of the rotating wheel 601 , corresponding to the locking claw 602 , and a connecting groove 604 for the locking claw 602 to be embedded is opened on the inner side of the ratchet 603 .

[0037] In actual setting, the locking claw 602 is fitted to the inner side of the connecting groove 604 through the elastic force of the torsion spring, that is, when the ratchet 603 rotates clockwise, it can drive the rotating wheel 601 and the rear axle 3 to rotate, and when the ratchet 603 rotates counterclockwise, the locking claw 602 will be squeezed into the inside of the groove, and will not drive the rotating wheel 601 and the rear axle 3 to rotate.

[0038] At least two telescopic rods 605 are slidably connected inside the ratchet wheel 603. An arc-shaped support piece 606 is installed at one end of the telescopic rod 605 away from the rotating wheel 601. A semi-arc block 607 is rotatably connected inside the arc-shaped support piece 606. The semi-arc block 607 is connected to the arc-shaped support piece 606 through a torsion spring.

[0039] The telescopic rod 605 includes a vertical portion 6051 and a horizontal portion 6052. A sliding groove is provided inside the ratchet 603 for the vertical portion 6051 to slide up and down. Corresponding to the horizontal portion 6052, a square opening is provided on the front side of the ratchet 603 for the horizontal portion 6052 to penetrate and move up and down, and the square opening is connected to the sliding groove.

[0040] A transmission mechanism is disposed on the outer side of the ratchet 603 to adjust the distance between the arc-shaped support piece 606 and the ratchet 603 .

[0041] In actual use, the transmission mechanism drives the telescopic rod 605 to move up and down, and the telescopic rod 605 drives the arc-shaped support piece 606 and the semi-arc block 607 connected to it to move during the movement, so as to adjust the distance between the arc-shaped support piece 606 and the ratchet 603, thereby adjusting the outer diameter of the entire speed regulating device.

[0042] In actual configuration, a circular chain disc is formed by combining a plurality of arc-shaped support pieces 606 , that is, when the distance between the arc-shaped support piece 606 and the ratchet wheel 603 is larger, the outer diameter of the entire chain disc increases accordingly, and vice versa, the diameter of the chain disc decreases.

[0043] It should be noted that at least two semi-arc blocks 607 are both connected to the chain 5 in a transmission manner, and the chain 5 has a connecting hole inside for the semi-arc blocks 607 to be inserted.

[0044] Furthermore, in order to ensure that the locking claw 602 can effectively transmit power to the ratchet 603 , the front cross-section of the connecting groove 604 in this embodiment is in the shape of a triangle.

[0045] In detail, in order to adjust the size of the entire chain plate, the transmission mechanism in this embodiment includes a shifting gear 608, a fixing plate 609, a waterproof housing 610, a fixed axis motor 611 and a battery 612;

[0046] The shift gear 608 is sleeved on the outside of the rear axle 3, the waterproof housing 610 is installed on the ratchet 603 through the fixing plate 609, the fixed axis motor 611 and the battery 612 are both arranged on the outside of the waterproof housing 610, and the fixed axis motor 611 is electrically connected to the battery 612, and a transmission gear 613 is sleeved on the output end of the fixed axis motor 611, and the transmission gear 613 is transmission-connected with the shift gear 608 to drive the shift gear 608 to rotate, and a plurality of arc grooves are opened inside the shift gear 608, and a plurality of transverse portions 6052 are respectively inserted into the arc grooves.

[0047] In actual use, the output end of the fixed-axis motor 611 rotates to drive the transmission gear 613 to rotate, and the transmission gear 613 drives the 1-position gear 608 connected to it to rotate, thereby driving the horizontal part 6052 on the telescopic rod 605 to move, and the vertical part 6051 connected to it is driven to move by the horizontal part 6052, so as to adjust the distance between the arc-shaped support piece 606 and the ratchet 603.

[0048] In addition, in order to transmit the command for the fixed-axis motor 611 to rotate, a shift switch connected to the fixed-axis motor 611 signal is provided on the vehicle frame 1 .

[0049] In actual use, by pressing the shift switch, the output end of the fixed-axis motor 611 is driven to rotate, and the fixed-axis motor 611 drives the transmission gear 613 connected thereto to rotate.

[0050] In addition, in order to ensure that the chain 5 is always in a taut state, in this embodiment, a support rod 7 is rotatably connected to the frame 1, a compression spring 8 is installed between the support rod 7 and the side opposite to the frame 1, and a tensioning wheel 9 is rotatably connected to the bottom end of the support rod 7, and the tensioning wheel 9 is in contact with the inner side of the chain 5.

[0051] In actual setting, the tensioning wheel 9 fits against the inner side of the chain 5 and supports the chain 5 through the elastic force of the compression spring 8. That is, when the diameter of the chain plate is reduced, the compression spring 8 rebounds to ensure that the tensioning wheel 9 always supports the chain 5.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic expansion type bicycle speed change device, characterized in that: It comprises a frame (1), a front axle (2), a rear axle (3), a front sprocket (4), a chain (5) and a speed change mechanism (6); The front axle (2) and the rear axle (3) are both rotatably connected to the inside of the frame (1); the front sprocket (4) is sleeved on the outside of the front axle (2); the chain (5) is transmission-connected to the outside of the front sprocket (4); and the speed change mechanism (6) is installed on the outside of the rear axle (3); The speed change mechanism (6) is connected to the speed change mechanism (6) through a chain (5); The speed change mechanism (6) comprises a rotating wheel (601), the rotating wheel (601) being sleeved on the outside of the rear axle (3), a groove being formed on the outside of the rotating wheel (601), and a stop claw (602) being rotatably connected inside the groove, the stop claw (602) being connected to the inner wall of the groove via at least one torsion spring; A ratchet wheel (603) is sleeved on the outer side of the rotating wheel (601) and corresponds to the locking claw (602); a connecting groove (604) for the locking claw (602) to be embedded is opened on the inner side of the ratchet wheel (603); At least two telescopic rods (605) are slidably connected inside the ratchet wheel (603); an arc-shaped support piece (606) is installed at one end of the telescopic rod (605) away from the rotating wheel (601); a semi-arc-shaped block (607) is rotatably connected inside the arc-shaped support piece (606); and the semi-arc-shaped block (607) is connected to the arc-shaped support piece (606) via a torsion spring; The telescopic rod (605) comprises a vertical portion (6051) and a horizontal portion (6052); a sliding groove for the vertical portion (6051) to slide up and down is provided inside the ratchet wheel (603); a square opening for the horizontal portion (6052) to pass through and move up and down is provided on the front side of the ratchet wheel (603), corresponding to the horizontal portion (6052); and the square opening is communicated with the sliding groove; A transmission mechanism is provided on the outer side of the ratchet wheel (603) for adjusting the distance between the arc-shaped support piece (606) and the ratchet wheel.

2. The automatic expansion type bicycle speed change device according to claim 1, characterized in that: At least two of the semi-arc blocks (607) are transmission-connected to the chain (5).

3. The automatic expansion type bicycle speed change device according to claim 1, characterized in that: The front cross-section of the connecting groove (604) is in the shape of a triangle.

4. The automatic expansion type bicycle speed change device according to claim 1, characterized in that: The transmission mechanism comprises a shifting gear (608), a fixing plate (609), a waterproof housing (610), a fixed-axis motor (611) and a storage battery (612); The first shift gear (608) is sleeved on the outside of the rear axle (3); the waterproof housing (610) is mounted on the ratchet (603) via a fixing plate (609); the fixed-axis motor (611) and the storage battery (612) are both arranged on the outside of the waterproof housing (610); and the fixed-axis motor (611) and the storage battery (612) are electrically connected.

5. The automatic expansion type bicycle speed change device according to claim 4, characterized in that: A transmission gear (613) is sleeved on the output end of the fixed-axis motor (611), and the transmission gear (613) is transmission-connected to a shift gear (608) so as to drive the shift gear (608) to rotate.

6. The automatic expansion type bicycle speed change device according to claim 4, characterized in that: A plurality of arc-shaped grooves are provided inside the first shift gear (608), into which the plurality of transverse portions (6052) are inserted respectively.

7. The automatic expansion type bicycle speed change device according to claim 4, characterized in that: A gear shift switch connected to the fixed-axis motor (611) is provided on the vehicle frame (1).

8. The automatic expansion type bicycle speed change device according to claim 1, characterized in that: A support rod (7) is rotatably connected to the frame (1), a compression spring (8) is mounted between the side of the support rod (7) opposite to the frame (1), a tension wheel (9) is rotatably connected to the bottom end of the support rod (7), and the tension wheel (9) is in contact with the inner side of the chain (5).

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