Gear shift control system for a gearbox

Abstract

This invention relates to the field of gearbox technology, and in particular to a gear shifting control system for a gearbox, comprising a flexible shift fork mechanism, a shift guide drum, a shifting control gear set, and a shifting control mechanism. The flexible shift fork mechanism includes a shift fork seat, a shift fork arm rotatably connected to the shift fork seat, and an elastic element for driving the shift fork arm to reset. When the shift fork arm swings relative to the shift fork seat, the elastic element drives the shift fork arm to reset. A shift guide groove is provided on the circumferential surface of the shift guide drum, and a shift fork protrusion is provided on the upper part of the shift fork seat, the shift fork protrusion being movably disposed within the shift guide groove. This invention uses a rotatable connection between the shift fork arm and the shift fork seat, resulting in low friction, more flexible shifting, and a longer service life for the elastic element. Furthermore, it effectively avoids damage to the ratchet teeth caused by ratchet grinding, jamming, or forced pulling, effectively extending the service life of the elastic element, the gear shifting control system, and the gearbox itself.

Description

Technical Field

[0001] This invention relates to the field of gearbox technology, and in particular to a gear shifting control system for a gearbox. Background Technology

[0002] In a gearbox, a shift control system is needed to shift gears in order to enable the transmission and change of gears between different gear pairs. Most existing shift control systems use a rigid shift fork mechanism. When the shift fork drives the ratchet to engage with the gear for shifting, it is easy for the ratchet and gear teeth to hit each other, resulting in tooth knocking or jamming. When the ratchet and gear disengage, it is easy for the ratchet to be pulled hard, causing damage to the ratchet teeth.

[0003] Chinese invention patent application publication number CN115195932A discloses a bicycle bottom bracket gearbox with load-bearing shifting, which includes a shifting control mechanism. This mechanism employs an elastic notch and a spring plate on the shift fork, utilizing the repeated rebound deformation force of the spring plate to achieve the shift fork's elastic performance. During use, this shift fork structure requires the spring plate to not only perform reciprocating deformation but also to provide connection and support. This makes the spring plate highly susceptible to premature fatigue failure, leading to ratchet and gear tooth misalignment or jamming, and ultimately resulting in a short service life for the gearbox.

[0004] Given the shortcomings of existing gear shifting systems that employ rigid and flexible shift forks, there is an urgent need to provide a solution to overcome these technical problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a gear shifting control system for a transmission. The shift fork is rotatably connected to the shift fork arm and the shift fork seat, resulting in low friction, more flexible shifting and disengaging, and a longer service life for the elastic components. Furthermore, it effectively avoids damage to the ratchet teeth caused by ratchet grinding, jamming, or forced pulling.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] The present invention provides a gear shifting control system for a transmission, including a flexible shift fork mechanism, a shift guide drum for driving the flexible shift fork mechanism to move, a shifting control gear set for driving the shift guide drum to rotate, and a shifting control mechanism for driving the shifting control gear set to rotate.

[0008] The elastic shift fork mechanism includes a shift fork seat, a shift fork arm rotatably connected to the shift fork seat, and an elastic element for driving the shift fork arm to reset. When the shift fork arm swings relative to the shift fork seat, the elastic element drives the shift fork arm to reset.

[0009] The shift guide drum has a shift guide groove on its circumferential surface, and the shift fork seat has a shift fork protrusion on its upper part, which is movably disposed in the shift guide groove.

[0010] The upper part of the shift fork seat has two parallel sliding guide holes, and the shift fork seat is sleeved on the two guide rods through the sliding guide holes.

[0011] Preferably, the lower part of the shift fork seat is provided with a mounting groove, the shift fork arm is provided with a fork arm connecting part, and the fork arm connecting part is mounted on the mounting groove by a fork arm pivot.

[0012] The elastic element is a torsion spring, the spring body of which is mounted on the fork arm pivot, and the output end of the torsion spring clamps the fork arm connection and the fork seat.

[0013] The fork arm connecting part is provided with a receiving groove, the fork arm pivot passes through the receiving groove, the spring body of the torsion spring is installed in the receiving groove, and the output end extends out of the receiving groove and clamps the shift fork seat.

[0014] The fork arm is provided with a lower fork portion, and the inner sides of both ends of the lower fork portion are provided with pull posts, which are movably disposed in the fork groove on the circumferential surface of the ratchet.

[0015] The gear shifting control gear set includes a driven gear for gear shifting control mounted on the gear shifting guide drum and a driving gear for gear shifting control meshing with the driven gear for gear shifting control. A return spring for driving the gear to reset is provided on one side of the driving gear for gear shifting control. One end of the return spring is connected to the gear wall of the driving gear for gear shifting control, and the other end of the return spring is connected to the mounting shaft of the driving gear for gear shifting control.

[0016] The shift control mechanism includes a shift cable, a cable adjustment mechanism, and a cable controller. The shift control drive gear is provided with a cable mounting groove. One end of the shift cable is wound around the cable mounting groove, and the other end of the shift cable passes through the cable adjustment mechanism and enters the cable controller.

[0017] The cable adjustment mechanism includes a mounting base disposed on the gearbox housing, an adjusting screw connected to the mounting base, and a locking nut connected to the adjusting screw; the mounting base is provided with a seat thread hole, which communicates with the interior of the gearbox housing; the adjusting screw is a hollow structure and is provided with an adjusting thread section.

[0018] The adjusting threaded section is threadedly connected to the threaded hole of the seat body; the locking nut is sleeved on the adjusting threaded section and threadedly connected to the adjusting threaded section; the elastic shift fork mechanism, the shift guide drum, and the shift control gear set are all located inside the gearbox housing.

[0019] The adjusting screw is further provided with a screw head that connects to the adjusting thread section; the mounting base and the gearbox housing are integrally formed.

[0020] The cable adjustment mechanism further includes a cable conduit, and a conduit recess is provided at the end of the screw head away from the adjusting thread section. One end of the cable conduit is installed in the conduit recess.

[0021] The beneficial effects of this invention are:

[0022] (1) The present invention provides a gear shifting control system for a gearbox, wherein the shift fork is rotatably connected to the shift fork arm and the shift fork seat. When the shift fork arm swings relative to the shift fork seat, the elastic element always drives the shift fork arm to return to its original position. The deformation of the elastic element gives the elastic shift fork mechanism a clearance function, avoiding gear knocking and jamming when shifting gears, thus making the shift fork structure elastic. When the elastic shift fork mechanism drives the ratchet to shift gears and mesh with the gear, it has a force-relieving function, thereby avoiding hard contact between the ratchet and the gear end face ratchet teeth, which would cause gear knocking or jamming; when the ratchet disengages from the gear, it avoids hard pulling of the ratchet, which would damage the ratchet teeth.

[0023] (2) The present invention provides a gear shifting control system for a gearbox, wherein the shift fork is rotatably connected to the shift fork arm and the shift fork seat. The friction is small when the shift fork arm swings, making the ratchet and gear more flexible in shifting and disengaging. When the shift fork arm swings at a small angle relative to the shift fork seat, a large displacement of the ratchet can be obtained. Compared with the overall displacement of the shift fork used by existing rigid shift forks and some elastic shift forks, it not only has less wear and a longer service life, but also makes the elastic deformation of the elastic element small, avoiding premature failure of the elastic element, and effectively extending the service life of the elastic element, the elastic shift fork mechanism and the gearbox. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0025] Figure 2 This is a three-dimensional structural schematic diagram from another perspective of the present invention.

[0026] Figure 3 This is a three-dimensional structural diagram of the elastic shift fork mechanism described in this invention.

[0027] Figure 4 This is an exploded structural diagram of the elastic shift fork mechanism described in this invention.

[0028] Figure 5 This is a three-dimensional structural diagram of the elastic shift fork mechanism of the present invention after the ratchet is installed.

[0029] Figure 6 This is a three-dimensional structural diagram of the present invention after concealing the shift gear set and shift control mechanism.

[0030] Figure 7 This is an exploded view of the gear shift control mechanism of the present invention after the cable controller is hidden.

[0031] Figure 8 This is a three-dimensional structural diagram of the gear shift control mechanism of the present invention after the cable controller is hidden.

[0032] Figure 9 This is a three-dimensional structural diagram of the adjusting screw described in this invention.

[0033] Figure 10 This is a three-dimensional structural diagram of the gearbox described in this invention. Detailed Implementation

[0034] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention. The present invention will be described in detail below with reference to the accompanying drawings.

[0035] refer to Figures 1 to 10 As shown, a gear shifting control system for a transmission includes a flexible shift fork mechanism 5, a shift guide drum 6 for driving the flexible shift fork mechanism 5 to move, a shift control gear set 7 for driving the shift guide drum 6 to rotate, and a shift control mechanism 8 for driving the shift control gear set 7 to rotate. The flexible shift fork mechanism 5 includes a shift fork seat 1, a shift fork arm 3 rotatably connected to the shift fork seat 1, and an elastic element 2 for driving the shift fork arm 3 to reset. When the shift fork arm 3 swings relative to the shift fork seat 1, the elastic element 2 drives the shift fork arm 3 to reset. A shift guide groove 61 is provided on the circumferential surface of the shift guide drum 6, and a shift fork protrusion 13 is provided on the upper part of the shift fork seat 1. The shift fork protrusion 13 is movably disposed in the shift guide groove 61.

[0036] Specifically, one or more shift guide grooves 61 on the elastic shift fork mechanism 5 and the shift guide drum 6 can be provided as needed.

[0037] In practical applications, the shift control mechanism 8 drives the shift operation gear set 7 to rotate, which in turn drives the shift guide drum 6 to rotate, so that the shift guide 61 drives the shift fork protrusion 13 to move the elastic shift fork mechanism 5. During the movement of the elastic shift fork mechanism 5, when the ratchet teeth of the ratchet 01 collide with the ratchet teeth of the gear 02, the shift fork arm 3 swings relative to the shift fork seat 1. The elastic element 2 always drives the shift fork arm 3 to reset the ratchet 01. The deformation of the elastic element 2 gives the elastic shift fork mechanism 5 a clearance function, avoiding gear grinding and jamming when shifting gears; thus, the ratchet 01 meshes with the gear 02 to achieve gear shifting.

[0038] This invention employs a rotatable connection between the shift fork arm 3 and the shift fork seat 1. When the shift fork arm 3 swings relative to the shift fork seat 1, the elastic element 2 always drives the shift fork arm 3 to return to its original position, thus giving the shift fork structure elasticity. When the elastic shift fork mechanism 5 drives the ratchet 01 to engage with the gear 02, it has a force-dissipating effect, thereby preventing the ratchet 01 from hard-hitting the ratchet teeth on the end face of the gear 02, which could cause tooth knocking or jamming. When the ratchet 01 disengages from the gear 02, it can prevent the ratchet 01 from being pulled too hard, which could damage the ratchet teeth.

[0039] This invention employs a rotatable connection between the shift fork arm 3 and the shift fork seat 1. The shift fork arm 3 exhibits low friction during swing, making the ratchet 01 and gear 02 more flexible in shifting and disengaging. When the shift fork arm 3 swings at a small angle relative to the shift fork seat 1, it can achieve a large displacement of the ratchet 01. Compared with the overall displacement of the shift fork used by existing rigid shift forks and some elastic shift forks, this invention not only has less wear and a longer service life, but also results in less elastic deformation of the elastic element 2, preventing premature failure of the elastic element 2 and effectively extending the service life of the elastic element 2, the elastic shift fork mechanism 5, and the gearbox.

[0040] In this embodiment, the upper part of the shift fork seat 1 is provided with two parallel sliding guide holes 11, and the shift fork seat 1 is sleeved on the two guide rods 03 using the sliding guide holes 11. During operation, the shift fork seat 1 drives the entire elastic shift fork mechanism and ratchet 01 to move on the guide rods 03, so as to realize the engagement and disengagement of the ratchet 01 and the gear 02. Specifically, two sliding guide holes 11 are provided in parallel, so that the shift fork seat 1 is installed on the two guide rods 03. This double guide rod design effectively avoids the shift fork seat 1 and the entire elastic shift fork mechanism from shaking and flipping, so that the shift control system used in this gearbox has a stable structure and reliable transmission.

[0041] In this embodiment, the lower part of the shift fork seat 1 is provided with a mounting groove 12, and the shift fork arm 3 is provided with a fork arm connecting part 31. The fork arm connecting part 31 is mounted on the mounting groove 12 by a fork arm pivot 4. The elastic element 2 is a torsion spring, the spring body 21 of which is mounted on the fork arm pivot 4, and the output end 22 of the torsion spring clamps the fork arm connecting part 31 and the shift fork seat 1. Specifically, the fork arm connecting part 31 is mounted on the fork arm pivot 4, and both ends of the fork arm pivot 4 are mounted on the groove walls on both sides of the mounting groove 12. The fork arm connecting part 31 is accommodated in the mounting groove 12. This structure is compact and provides good stability when the shift fork arm 3 rotates.

[0042] In this embodiment, the fork arm connecting part 31 is provided with a receiving groove 311, the fork arm rotating shaft 4 passes through the receiving groove 311, the spring body 21 of the torsion spring is installed in the receiving groove 311, and the output end 22 extends out of the receiving groove 311 and clamps the shift fork seat 1. Installing the spring body 21 of the torsion spring in the receiving groove 311 not only ensures structural stability and reliable installation, but also makes the elastic shift fork mechanism 5 more compact.

[0043] In this embodiment, the fork arm 3 is provided with a lower fork portion 32, and the inner sides of both ends of the lower fork portion 32 are provided with pull posts 321, which are movably disposed in the fork groove 011 on the circumferential surface of the ratchet 01.

[0044] In this embodiment, the shift control gear set 7 includes a shift control driven gear 71 mounted on the shift guide drum 6 and a shift control driving gear 72 meshing with the shift control driven gear 71. A return spring 73 for driving gear reset is provided on one side of the shift control driving gear 72. One end of the return spring 73 is connected to the gear wall of the shift control driving gear 72, and the other end is connected to the mounting shaft of the shift control driving gear 72. Specifically, the shift control mechanism 8 includes a shift cable 81, a cable adjustment mechanism 82, and a cable controller. The shift control driving gear 72 has a cable mounting groove. One end of the shift cable 81 is wound around the cable mounting groove, and the other end of the shift cable 81 passes through the cable adjustment mechanism 82 and enters the cable controller. The cable controller can be implemented using an existing controller structure, and therefore will not be described in detail.

[0045] In this embodiment, the cable adjustment mechanism 82 is used to adjust the tension of the shift cable 81. When a shift is needed, the cable controller controls the shift cable 81 to drive the shift control drive gear 72 to rotate. The shift control drive gear 72 drives the shift control driven gear 71 to rotate, thereby driving the shift guide drum 6 to rotate. This drives the elastic shift fork mechanism 5 to move, causing the ratchet 01 to mesh with the gear 02, thus achieving a shift. When the force that drives the shift cable 81 to rotate the shift control drive gear 72 is released, the return spring 73 drives the shift control drive gear 72 to reset.

[0046] To overcome the problems of existing cable adjustment mechanisms being mounted on the vehicle frame, which makes it difficult to observe the tension of the shift cable in the transmission and leads to extremely inconvenient adjustments; and the shift cable easily loosening during use after adjustment, this invention provides a cable adjustment mechanism 82, which includes a mounting base 100 disposed in the transmission housing 400, an adjusting screw 200 connected to the mounting base 100, and a locking nut 300 connected to the adjusting screw 200; the mounting base 100 is provided with a seat threaded hole 101, which communicates with the interior of the transmission housing 400; the adjusting screw 200 is a hollow structure and is provided with an adjusting threaded section 201; the adjusting threaded section 201 is threadedly connected to the seat threaded hole 101; the locking nut 300 is sleeved on the adjusting threaded section 201 and threadedly connected to the adjusting threaded section 201; the elastic shift fork mechanism 5, the shift guide drum 6, and the shift control gear set 7 are all disposed inside the transmission housing 400.

[0047] In practical application, one end of the shift cable 81 is wound around the shift control drive gear 72, and the other end of the shift cable 81 passes through the mounting base 100 and the adjusting screw 200 in sequence before connecting to the cable controller at the handlebars of the frame. When the shift cable 81 is first installed, it is still loose. At this time, simultaneously tightening the adjusting screw 200 and the locking nut 300 on the adjusting thread section 201 shortens the threaded engagement section between the mounting base 100's threaded hole 101 and the adjusting thread section 201, thereby increasing the exposed length of the adjusting thread section 201 in the mounting base 101. This increases the length of the adjusting thread section 201 used to fit and accommodate the shift cable 81, thus tensioning the shift cable 81. After the shift cable 81 is tensioned, the adjusting thread section 201 is tightened separately, causing its end face to abut against the mounting base 100. At this point, the adjusting screw 200 is not easily screwed into the threaded hole 101 of the mounting base 100, thus achieving locking of the shift cable 81 after tensioning.

[0048] This cable adjustment mechanism 82 uses a mounting base 100 mounted on the gearbox housing 400, which makes it easy to install components such as the adjusting screw 200 and the locking nut 300 without having to install them on the bicycle frame or other places. This not only makes installation convenient but also makes effective use of the installation location and saves other installation space. Furthermore, it is securely fixed, making its structure stable.

[0049] This cable adjustment mechanism 82 uses a mounting base 100 mounted on the gearbox housing 400. When adjusting the tension of the shift cable 81 by turning the adjusting thread section 201 and the locking nut 300, the tension of the shift cable 81 on the shift control drive gear 72 can be observed in real time. Compared with existing cable adjustment devices, it effectively increases the convenience and efficiency of adjusting the shift cable 81, thereby improving the overall assembly efficiency of the gearbox product and reducing labor costs.

[0050] This cable adjustment mechanism 82 adjusts the tightness of the shift cable 81 by shortening or increasing the engagement length between the adjusting screw 200 and the mounting base 100. It only requires turning the adjusting screw 200 in both directions, making it simple to operate and easy for workers to learn. At the same time, a locking nut 300 is used to lock the shift cable 81, making it less likely to loosen during use. This improves the reliability of the shift control mechanism and enhances the overall quality of the gearbox product.

[0051] In this embodiment, the adjusting screw 200 is further provided with a screw head 202 connected to the adjusting thread section 201, which facilitates tightening and adjustment, and also facilitates the installation of other components such as the cable conduit 500. The mounting base 100 and the gearbox housing 400 are integrally formed. Specifically, the mounting base 100 and the gearbox housing 400 are machined together, thereby reducing the need for separate processing of parts. This not only avoids the cumbersome process of processing multiple parts and then assembling them, but also makes the installation of parts convenient and the structure more stable after installation.

[0052] In this embodiment, the cable adjustment mechanism 82 further includes a cable conduit 500. A conduit recess 203 is provided at the end of the screw head 202 away from the adjusting thread section 201, and one end of the cable conduit 500 is installed in the conduit recess 203. Using the conduit recess 203 to accommodate, install, and position the cable conduit 500 facilitates the threading and tensioning of the shift cable 81.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present invention without departing from the scope of the present invention are within the scope of the present invention.

Claims

1. A gear shifting control system for a transmission, characterized in that: It includes a flexible shift fork mechanism (5), a shift guide drum (6) for driving the flexible shift fork mechanism (5) to move, a shift control gear set (7) for driving the shift guide drum (6) to rotate, and a shift control mechanism (8) for driving the shift control gear set (7) to rotate. The elastic shift fork mechanism (5) includes a shift fork seat (1), a shift fork arm (3) rotatably connected to the shift fork seat (1), and an elastic element (2) for driving the shift fork arm (3) to reset. When the shift fork arm (3) swings relative to the shift fork seat (1), the elastic element (2) drives the shift fork arm (3) to reset. The shift guide drum (6) has a shift guide groove (61) on its circumferential surface, and the shift fork seat (1) has a shift fork protrusion (13) on its upper part. The shift fork protrusion (13) is movably disposed in the shift guide groove (61). The lower part of the shift fork seat (1) is provided with a mounting groove (12), and the shift fork arm (3) is provided with a fork arm connecting part (31). The fork arm connecting part (31) is mounted on the mounting groove (12) by a fork arm pivot (4). The elastic element (2) is a torsion spring. The spring body (21) of the torsion spring is installed on the fork arm pivot (4). The output end (22) of the torsion spring clamps the fork arm connecting part (31) and the fork seat (1). The fork arm connecting part (31) is provided with a receiving groove (311), the fork arm rotating shaft (4) passes through the receiving groove (311), the spring body (21) of the torsion spring is installed in the receiving groove (311), and the output end (22) extends out of the receiving groove (311) and clamps the shift fork seat (1).

2. The gear shifting control system for a transmission according to claim 1, characterized in that: The upper part of the shift fork seat (1) is provided with two sliding guide holes (11) arranged side by side. The shift fork seat (1) is sleeved on the two guide rods (03) through the sliding guide holes (11).

3. A gear shifting control system for a transmission according to claim 1 or 2, characterized in that: The fork arm (3) is provided with a lower fork (32), and the inner sides of both ends of the lower fork (32) are provided with pull posts (321), which are movably disposed in the fork groove (011) on the circumferential surface of the ratchet (01).

4. The gear shifting control system for a transmission according to claim 1, characterized in that: The shift control gear set (7) includes a shift control driven gear (71) mounted on the shift guide drum (6) and a shift control driving gear (72) meshing with the shift control driven gear (71). A return spring (73) for driving the gear to reset is provided on one side of the shift control driving gear (72). One end of the return spring (73) is connected to the gear wall of the shift control driving gear (72), and the other end of the return spring (73) is connected to the mounting shaft of the shift control driving gear (72).

5. The gear shifting control system for a transmission according to claim 4, characterized in that: The shift control mechanism (8) includes a shift cable (81), a cable adjustment mechanism (82), and a cable controller. The shift control drive gear (72) is provided with a cable mounting groove. One end of the shift cable (81) is wound around the cable mounting groove, and the other end of the shift cable (81) passes through the cable adjustment mechanism (82) and enters the cable controller.

6. The gear shifting control system for a transmission according to claim 5, characterized in that: The cable adjustment mechanism (82) includes a mounting base (100) disposed on the gearbox housing (400), an adjustment screw (200) connected to the mounting base (100), and a locking nut (300) connected to the adjustment screw (200). The mounting base (100) is provided with a seat threaded hole (101), which communicates with the inside of the gearbox housing (400); the adjusting screw (200) is a hollow structure and is provided with an adjusting thread section (201). The adjusting thread section (201) is threadedly connected to the threaded hole (101) of the seat body; the locking nut (300) is sleeved on the adjusting thread section (201) and threadedly connected to the adjusting thread section (201); The elastic shift fork mechanism (5), the shift guide drum (6), and the shift control gear set (7) are all located inside the gearbox housing (400).

7. The gear shifting control system for a transmission according to claim 6, characterized in that: The adjusting screw (200) is also provided with a screw head (202) connected to the adjusting thread section (201); the mounting base (100) and the gearbox housing (400) are integrally formed.

8. The gear shifting control system for a transmission according to claim 7, characterized in that: The pull wire adjustment mechanism (82) also includes a pull wire tube (500), and a tube recess (203) is provided at the end of the screw head (202) away from the adjustment thread section (201), and one end of the pull wire tube (500) is installed in the tube recess (203).

Images