Variable leverage brake

Abstract

The utility model relates to brake technology field discloses a brake of variable lever ratio, solves the problem that fixed lever ratio cannot consider assembly convenience and braking performance. It includes brake casing, piston subassembly, brake handle, push rod subassembly, is equipped with transmission lever and guide mechanism still, transmission lever front end is hinged with brake handle through first transmission subassembly, and the middle part is hinged with push rod subassembly through second transmission subassembly, and guide mechanism is connected with transmission lever and drives it to change the relative position of input point position and output point position. The utility model discloses lever ratio can be multi -gear or continuously regulated, and adapts to different braking conditions, and brake gain is realized to the transmission lever of adding, and the braking force is significantly improved in the later period of labor saving in the early stage of braking, and the motion change amount of push rod subassembly is greater when the same handle stroke is pinched, and assembly convenience and braking performance are considered.

Description

Technical Field

[0001] This utility model relates to the field of braking system technology, specifically to a variable lever ratio brake suitable for vehicles, mechanical equipment, etc., and is particularly suitable for scenarios where there is a need for flexible adjustment of braking force and operating stroke. Background Technology

[0002] As a core safety component of vehicles and mechanical equipment, the performance of brakes directly affects safety and ease of operation. Current brake technologies typically employ a fixed lever ratio design, meaning the transmission ratio between the operating force of the brake lever and the thrust of the piston assembly remains constant.

[0003] A prior art example, referring to patent document CN223355806U, discloses a hydraulic brake with adjustable stroke, including a brake body, a piston rod, a handle, and a transmission rod; it also includes a cylinder liner and an adjusting component; the cylinder liner is movably disposed within a pressure cylinder, and the cylinder liner has at least a first position state and a second position state relative to the pressure cylinder, and the movement of the cylinder liner can cause the piston rod to move relative to the pressure cylinder, thereby changing the set starting position of the piston rod; the adjusting component is movably connected to the brake body, and the adjusting component includes an operating end and an actuating end, with the actuating end of the adjusting component abutting against the cylinder liner; this invention achieves the purpose of adjusting the brake's idle stroke by having the adjusting component act on the cylinder liner to move it, thereby causing the transmission rod and piston rod that cooperate with the cylinder liner to move accordingly, thus changing the set starting position of the piston rod, and achieving the purpose of adjusting the brake's idle stroke, and since the cylinder liner and piston rod move together, the cooperation relationship between the two does not change.

[0004] However, in actual use, the requirements for brakes vary significantly depending on the operating conditions: for example, during emergency braking, a small operating stroke is needed to obtain a large braking force for rapid braking; while during low-speed braking or normal braking, a moderate operating stroke is required to match the braking force, balancing operating comfort and braking smoothness. Brakes with a fixed lever ratio cannot simultaneously meet the needs of these different operating conditions, resulting in problems such as delayed braking response, difficult operation, or excessive braking. Furthermore, existing adjustable lever ratio braking mechanisms often employ complex gear transmissions or multi-link structures, resulting in drawbacks such as bulky structures, low adjustment precision, and poor reliability, making them unsuitable for miniaturized and lightweight brake design requirements. Therefore, there is an urgent need for a compact, easily adjustable, and highly reliable variable lever ratio brake to address the shortcomings of existing technologies. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of existing brakes with fixed lever ratios that cannot adapt to various working conditions, and to provide a brake with a variable lever ratio. By optimizing the transmission structure design, the lever ratio can be flexibly adjusted, taking into account the braking force and operating stroke requirements under different working conditions. It is also compact, easy to adjust, and highly reliable.

[0006] The technical solution of this utility model to solve its technical problem is: a brake with a variable lever ratio, comprising: A brake housing having a piston chamber having a front opening and a rear opening; A piston assembly, which is movably disposed in the piston chamber; Brake handle, which is rotatably connected to the brake housing via a pivot shaft; The push rod assembly is positioned at the rear end of the piston assembly, and the push rod assembly and the piston assembly form a transmission engagement. It also includes: A transmission lever, wherein the front end of the transmission lever is pivotally connected to the brake handle through a first transmission assembly to form a transmission engagement, and the middle part of the transmission lever is pivotally connected to the push rod assembly through a second transmission assembly to form a transmission engagement; A guide mechanism is mounted on the brake housing and is connected to the transmission lever to form a transmission engagement. The connection point between the transmission lever and the first transmission component is the input point, the connection point between the transmission lever and the second transmission component is the output point, and the connection point between the transmission lever and the guide mechanism is the guide point. When the guide mechanism changes position, it causes the transmission lever to change position relative to the brake housing, thereby changing the relative position of the output point and the input point on the transmission lever.

[0007] Preferably, the output points, input points, and guide points are arranged sequentially from front to back.

[0008] More specifically, during the process of the user squeezing the brake handle, the transmission lever moves forward, the input point rotates around the pivot shaft, the output point rotates around the contact point between the push rod assembly and the piston assembly, and the guide point rotates around the guide mechanism.

[0009] In a preferred embodiment of this utility model, the guiding mechanism includes a guide wheel, a guide wheel connecting shaft, a guide shaft, and a guide rocker arm; The guide wheel is connected to the brake housing; The guide wheel connecting shaft is connected to the guide wheel; The transmission lever is provided with a third transmission hole, and the guide shaft is inserted into the third transmission hole; One end of the guide rocker arm is connected to the guide shaft, and the other end of the guide rocker arm is connected to the guide wheel connecting shaft. The guide rocker arm and the guide shaft are arranged perpendicular to each other. The guide wheel connecting shaft and / or guide wheel spindle are eccentrically mounted on the guide wheel.

[0010] A further provision of the above technical solution is that: a guide wheel spindle is provided on the side of the guide wheel, and a connecting hole is provided on the brake housing; the guide wheel spindle is inserted into the connecting hole to achieve a rotational connection between the guide wheel and the brake housing.

[0011] A further provision of the above technical solution is that the brake housing is also provided with several gear slots; The guide wheel is also equipped with a spring stop, which can be engaged into any one of the gear slots.

[0012] A further provision of the above technical solution is that: the guide wheel connecting shaft extends at least partially out of the brake housing and is equipped with a knob, the knob being responsive to user operation; The knob is provided with an indicator protrusion, which is positioned opposite to the spring stop and can point to any one of the stop slots.

[0013] In a preferred embodiment of the present invention, the guiding mechanism includes a variable guide groove formed on the brake housing and a guide block disposed on the transmission lever. The guide block is inserted into the variable guide groove and can move along the variable guide groove.

[0014] A further provision of the above technical solution is that the guide block has an initial position and an end position in the variable guide groove, the variable guide groove is arc-shaped, and the height of the initial position of the variable guide groove is higher than the height of the end position.

[0015] In a preferred embodiment of the present invention, the first transmission assembly includes a drive shaft and a first pivot sleeve; the drive shaft is fixed on the brake handle, the transmission lever has a first transmission hole, the first pivot sleeve is disposed in the first transmission hole, and the drive shaft is rotatably inserted into the first pivot sleeve. The second transmission assembly includes an output shaft, a fastener, and a second pivot sleeve; the push rod assembly is connected to the output shaft, the transmission lever has a second transmission hole, the second pivot sleeve is disposed in the second transmission hole, the output shaft has a locking hole, a portion of the fastener is rotatably inserted into the first pivot sleeve, and the other portion of the fastener is threaded into the locking hole and abuts against the push rod assembly; the output shaft and the push rod assembly are arranged perpendicular to each other.

[0016] Detailed explanation of the braking process of this utility model: Initial state: The piston assembly is in its initial position in the piston chamber, the hydraulic pressure in the oil pipe at the front end of the piston chamber is maintained at constant pressure, and there is no pressure difference with the hydraulic circuit of the brake pump; the push rod assembly is in light contact with the rear end of the piston assembly, and no thrust is generated; the three core points of the transmission lever (output point, input point, and guide point) are in the preset initial position, and the three points are arranged linearly from front to back; the drive shaft of the first transmission assembly and the first pivot sleeve, and the output shaft of the second transmission assembly and the second pivot sleeve are all in a state of free rotation without load; the guide mechanism has not experienced any positional deviation and maintains the initial trajectory constraint on the transmission lever.

[0017] Triggering Phase (Handle Force Application, Output Point Activation): When the user squeezes the brake handle, the braking process officially begins: the brake handle rotates clockwise around the pivot shaft (taking a conventional right-hand brake handle as an example), and the first transmission component fixed on the handle drives the shaft to rotate synchronously, and through the first pivot sleeve, drives the output point of the transmission lever to move upward and towards the handle; the force applied by the handle in this phase is the "input force", and the initial transmission of force is completed through the first transmission component. Since the lever ratio (the ratio of the lever arm of the output point to the input point) is small in the initial state, the user only needs a small grip force to drive the transmission lever to start, achieving a rapid braking response.

[0018] Transmission Stage (Compound Motion, Dynamic Adjustment of Lever Ratio): After the output point is activated, the transmission lever enters a compound motion state of "forward movement + rotation" under the constraint of the guide mechanism, while simultaneously achieving an adaptive increase in the leverage ratio: The guide mechanism applies trajectory constraints to the guide point of the transmission lever, forcing the transmission lever to move forward (towards the piston chamber) along the guide trajectory while the output point moves upward; the input point of the transmission lever moves forward with the whole and rotates around the guide point; at this time, the lever arm of the input point (distance from the guide point to the input point) gradually increases, and the lever arm of the output point (distance from the guide point to the output point) gradually decreases, and the leverage ratio (input lever arm / output lever arm) continuously increases, achieving a force amplification effect of "small gripping force → large thrust"; the output shaft of the second transmission component moves with the input point. Since the output shaft is perpendicular to the push rod assembly, its rotational torque is converted into a linear thrust along the piston chamber axis. Through the locking limit of the fasteners, the force is stably transmitted to the push rod assembly.

[0019] Braking Phase (Hydraulic Drive, Brake Effective): After receiving the thrust, the push rod assembly triggers a pressure change in the hydraulic circuit, completing the final braking: Under the push of the output shaft, the push rod assembly moves forward along the piston chamber axis, directly pushing the piston assembly to compress the hydraulic oil in the piston chamber; the hydraulic oil pressure in the piston chamber rises sharply and is transmitted to the lower brake pump through the front oil pipe, driving the brake shoes / brake pads of the lower pump to clamp the brake disc / brake drum, achieving wheel braking; at this stage, because the leverage ratio has been increased to its peak, the user can obtain sufficient braking force even without further increasing the grip force, ensuring braking effect while avoiding hand fatigue caused by excessive grip force.

[0020] Reset process: When the brake lever is released, the components return to their initial positions under the action of the reset spring (usually integrated into the piston assembly), waiting for the next braking.

[0021] The beneficial effects of this utility model are as follows: 1. Flexible and adjustable leverage ratio: The guide mechanism drives the guide point of the transmission lever to move, changing the relative position of the output point and the input point, so as to realize the multi-level or continuous adjustment of the leverage ratio. It can adapt the best braking force and operating stroke according to different working conditions (emergency braking, normal braking, etc.). II. Convenient Operation: In the first embodiment, the user can switch gears by rotating the knob, the spring-loaded gear achieves precise positioning, and the indicator protrusion facilitates gear identification; in the second embodiment, when the transmission lever moves, the guide block automatically adapts to the position along the variable guide groove, without the need for additional operation. 3. Compact and reliable structure: It adopts a three-point transmission lever and integrated guide mechanism design, with fewer parts and a reasonable layout, avoiding the reliability problems caused by complex transmission structures; the transmission components adopt a pivot sleeve fit design, reducing wear and extending service life; IV. Wide adaptability: It can be widely used in various equipment that require braking systems, such as motorcycles, bicycles, electric vehicles, and construction machinery, to meet the personalized braking performance needs of different users. V. Braking performance optimization: By adjusting the lever ratio, the lever ratio can be increased during emergency braking to obtain greater braking force with a smaller operating stroke, thereby improving braking response speed; the lever ratio can be decreased during normal braking to balance operating comfort and braking smoothness. VI. Braking Gain: A transmission lever is added, changing the pivot point of the push rod assembly's movement (from the pivot shaft to the second point on the transmission lever). During the braking process, the push rod assembly not only rotates (upwards) itself, but the transmission lever (with the guide block and guide groove engaging) also rotates slightly forward, providing additional motion gain to the push rod assembly. That is, for the same stroke of the brake lever, the push rod assembly in this invention exhibits a greater range of motion changes. Furthermore, the brake of this invention has a small lever ratio in the initial braking phase, allowing for a large amount of hydraulic pressure from the user, enabling the caliper piston to quickly extend the brake pads; in the later stages of braking, the lever ratio dynamically adjusts and increases, significantly improving braking force, thus solving the problem of a fixed lever ratio failing to balance ease of assembly and braking performance. Attached Figure Description

[0022] Figure 1 This is a structural schematic diagram of Embodiment 2 of this utility model.

[0023] Figure 2 This is a structural exploded view of Embodiment 2 of this utility model.

[0024] Figure 3 This is a partial exploded view of Embodiment 2 of this utility model.

[0025] Figure 4 This is a comparative cross-sectional view of Example 2 (gear 1) at the initial braking stage, the middle braking stage, and the final braking stage.

[0026] Figure 5 This is a comparative schematic diagram of the partial structure in Example 2 (gear 1) at the initial stage of braking, the middle stage of braking, and the end stage of braking.

[0027] Figure 6 This is a comparative cross-sectional view of Example 2 (gear 2) at the initial braking stage, the middle braking stage, and the final braking stage.

[0028] Figure 7 This is a comparative schematic diagram of the partial structure in Example 2 (gear 2) at the initial stage of braking, the middle stage of braking, and the end stage of braking.

[0029] Figure 8 This is a schematic diagram of the transmission lever and guide mechanism in Embodiment 2.

[0030] Figure 9 This is a schematic diagram of the transmission lever and guide mechanism from another angle in Embodiment 2.

[0031] Figure 10 This is a schematic diagram comparing the handle output rate and handle travel in Example 2.

[0032] Figure 11 This is a structural schematic diagram of Embodiment 3 of this utility model.

[0033] Figure 12 This is a structural exploded view of Embodiment 3 of this utility model.

[0034] Figure 13 This is a comparative schematic diagram of the initial braking stage, the middle braking stage, and the final braking stage in Example 3.

[0035] Figure 14 This is a comparative schematic diagram of the partial structure in Example 3 at the initial stage of braking, the middle stage of braking, and the end stage of braking.

[0036] Figure 15 This is a comparative cross-sectional view of the initial braking stage, the middle braking stage, and the final braking stage of Example 3.

[0037] Figure 16 This is a schematic diagram comparing the handle output rate and handle travel in Example 3.

[0038] In the diagram: 1. Brake housing; 11. Piston chamber; 12. Front opening; 13. Rear opening; 14. Connecting hole; 15. Gear slot; 16. Spring-loaded gear; 17. Knob; 171. Indicator protrusion; 2. Piston assembly; 21. Ball joint groove; 22. Return spring; 3. Brake handle; 31. Pivot shaft; 4. Transmission lever; 4a. Output point; 4b. Input point; 4c. Guide point; 41. First transmission hole; 42. Second transmission hole; 43. Third transmission hole; 5. ... 51. Transmission assembly; 52. Drive shaft; 53. First pivot sleeve; 6. Second transmission assembly; 61. Output shaft; 611. Locking hole; 62. Fastener; 63. Second pivot sleeve; 7. Push rod assembly; 71. Ball head section; 8. Guide mechanism; 811. Guide wheel; 812. Guide wheel connecting shaft; 813. Guide shaft; 814. Guide rocker arm; 815. Guide wheel spindle; 821. Variable guide groove; 8211. Initial position; 8212. End position; 822. Guide block. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example

[0040] Reference Figures 1 to 16A variable lever ratio brake includes: a brake housing 1, which is an integral load-bearing structure, having a piston chamber 11, the piston chamber 11 having a front opening 12 (for connecting an oil pipe, the other end of which is connected to the brake lower pump) and a rear opening 13 (for mounting and using accessories such as a piston assembly 2 and a push rod assembly 7); a piston assembly 2, which is movably disposed in the piston chamber 11; a brake handle 3, which is rotatably connected to the brake housing 1 via a pivot shaft 31 (the pivot shaft 31 preferably adopts a structure scheme in the prior art, which will not be described in detail here); and a push rod assembly 7, which is disposed at the rear end of the piston assembly 2, and the push rod assembly 7 forms a transmission engagement with the piston assembly 2.

[0041] Unlike existing technologies, this disclosure also includes a transmission lever 4. The front end of the transmission lever 4 is pivotally connected to the brake handle 3 via a first transmission assembly 5, forming a transmission engagement. The middle part of the transmission lever 4 is pivotally connected to the push rod assembly 7 via a second transmission assembly 6, forming a transmission engagement. A guide mechanism 8 is disposed on the brake housing 1 and is connected to the transmission lever 4, forming a transmission engagement. By changing its own position, the guide mechanism 8 drives the transmission lever 4 to adjust its position relative to the brake housing 1, thereby changing the relative position of the output point 4a and the input point 4b, and realizing lever ratio adjustment. The connection point between the transmission lever 4 and the first transmission assembly 5 is the input point 4b, the connection point between the transmission lever 4 and the second transmission assembly 6 is the output point 4a, and the connection point between the transmission lever 4 and the guide mechanism 8 is the guide point 4c. When the guide mechanism 8 changes position, it drives the transmission lever 4 to change its position relative to the brake housing 1, so that the relative position of the output point 4a and the input point 4b on the transmission lever 4 changes. The technical advantages are at least as follows: First, the three-point layout of the transmission lever 4 ensures stable force transmission. The output point 4a, input point 4b, and guide point 4c are arranged from front to back, which conforms to the mechanical transmission law and reduces transmission interference. Second, the first transmission component 5 and the second transmission component 6 adopt a pivot sleeve structure, which reduces rotational friction and improves transmission efficiency and service life.

[0042] The working process of the above technical solution is as follows: the user squeezes the brake handle 3, which causes the output point 4a of the transmission lever 4 to move upward. Under the action of the guide mechanism 8, the transmission lever 4 moves forward and rotates along a predetermined trajectory. The output point 4a drives the push rod assembly 7 to push the piston assembly 2 to brake through the second transmission component 6.

[0043] Preferably, the output point 4a, input point 4b, and guide point 4c are arranged sequentially from front to back. The output point 4a (connected to the first transmission assembly 5 of the brake handle 3), the input point 4b (connected to the second transmission assembly 6 of the push rod assembly 7), and the guide point 4c (connected to the guide mechanism 8) are arranged from front to back, forming a stable mechanical transmission triangle. During the user's squeezing of the brake handle 3, the transmission lever 4 moves forward, and the input point 4b rotates around the pivot shaft 31, the output point 4a rotates around the contact point between the push rod assembly 7 and the piston assembly 2, and the guide point 4c rotates around the guide mechanism 8.

[0044] By changing the relative positions of the output / input points 4b, the lever ratio is dynamically adjusted during braking. Typically, the lever ratio is small in the initial braking phase to ensure rapid response, and large in the later stages to increase braking force. Compared to traditional fixed-lever-ratio brakes: First, this design resolves the contradiction between braking response and braking force: Traditional brakes have a fixed lever ratio; if a sensitive response is desired, the braking force is insufficient, and if a large braking force is desired, the handle travel is too long. This design achieves a balance between rapid initial response and strong braking force through a dynamically changing lever ratio. Second, it offers higher transmission efficiency: the pivot sleeve structure replaces the traditional direct shaft-hole fit, significantly reducing rotational friction, minimizing force loss, and extending component lifespan.

[0045] It should be noted that in the brake lever ratio change mechanism of the existing brake system: when the brake handle 3 is squeezed, the force is transmitted to the piston assembly 2 through the push rod assembly 7. On the one hand, the push rod assembly 7 and the piston assembly 2 are not on the same straight line. Therefore, there is a certain angle between the push rod force line of the push rod assembly 7 and the piston force line of the piston assembly 2. That is, when the two transmit force, there will inevitably be a certain force loss. It is certain that the larger the angle, the greater the force loss and the lower the force transmission efficiency. On the other hand, the brake handle 3 and the push rod assembly 7 are in an approximate lever relationship. The second point is the pivot shaft 31. When the brake handle 3 is squeezed, the brake handle 3 rotates (downward) around the pivot shaft 31, and the push rod assembly 7 at the other end rotates (upward). The greater the squeezing force, the smaller the angle between the push rod force line and the piston force line. The lever ratio change mechanism of this utility model is as follows: as the gripping stroke increases, the first point rises continuously and the third point falls along the guide groove. The curved design of the guide groove causes the rotation center (third point) of the transmission lever 4 to change continuously, and the vertical distance (lever arm) between the first point and the second point changes accordingly, so as to realize the lever ratio is continuously adjustable during the pinching brake process.

[0046] Reference Figure 3 , Figure 12 The specific structure of the transmission assembly: I. First transmission assembly 5: includes a drive shaft 51 and a first pivot sleeve 52; the drive shaft 51 is fixed to the brake handle 3, the transmission lever 4 has a first transmission hole 41, the first pivot sleeve 52 is disposed in the first transmission hole 41, and the drive shaft 51 is rotatably inserted into the first pivot sleeve 52. The first pivot sleeve 52 is installed in the first transmission hole 41 of the transmission lever 4 to ensure no relative movement between the two; the drive shaft 51 is connected to the brake handle 3 and rotates synchronously with the brake handle 3 around the pivot shaft 31; through the cooperation of the drive shaft 51 and the first pivot sleeve 52, the force when the brake handle 3 is squeezed is transmitted to the transmission lever 4.

[0047] II. Second transmission assembly 6: includes an output shaft 61, a fastener 62, and a second pivot sleeve 63; the push rod assembly 7 is connected to the output shaft 61, the transmission lever 4 has a second transmission hole 42, the second pivot sleeve 63 is disposed in the second transmission hole 42, the output shaft 61 has a locking hole 611, a part of the fastener 62 is rotatably inserted into the first pivot sleeve 52, and the other part of the fastener 62 is threaded into the locking hole 611 and abuts against the push rod assembly 7; the output shaft 61 and the push rod assembly 7 are arranged perpendicular to each other to ensure the conversion of transmission direction and the effective transmission of force. The second pivot sleeve 63 is installed in the second transmission hole 42 of the transmission lever 4 to ensure that there is no relative movement between the two; the output shaft 61 passes through the second pivot sleeve 63, so that the two form a rotatable fit; the head of the fastener 62 (such as a bolt) is rotatably inserted into the first pivot sleeve 52, and the rod passes through the locking hole 611 of the output shaft 61 and is fastened by a threaded connection, while abutting against the push rod assembly 7, which plays a role in filling the gap and preventing swaying; the output shaft 61 is set perpendicular to the push rod assembly 7, which accurately converts the arc swing of the transmission lever 4 into the linear motion of the push rod assembly 7, while the low friction characteristics of the second pivot sleeve 63 ensure transmission efficiency and stability. The advantages of adopting the above scheme are: first, the output shaft 61 can accurately match the arc-shaped motion trajectory of the first position rising and the third position falling, ensuring that the lever ratio changes according to the design law; second, the vertical connection between the output shaft 61 and the push rod assembly 7 amplifies the small angle change of the transmission lever 4 into a larger linear displacement of the push rod, enhancing the sensitivity and controllability of the lever ratio change; and third, it prevents the deformation of the transmission structure caused by vibration or long-term use, ensuring the long-term stability of the lever ratio control accuracy.

[0048] Preferably, the piston assembly 2 has a ball joint groove 21 at its rear end, and the push rod assembly 7 has a ball joint section 71 at its front end. The ball joint section 71 extends into the ball joint groove 21 and abuts against it, so that the push rod assembly 7 and the piston assembly 2 form a transmission engagement. The ball joint section 71 and the ball joint groove 21 form a rotatable engagement without a fixed connection. This is a commonly used engagement method between the push rod assembly 7 and the piston assembly 2 in a brake. When the push rod assembly 7 performs complex trajectory movements, the ball joint section 71 can rotate flexibly within the ball joint groove 21, and the angle adaptively eliminates jamming, so that the brake handle 3 can be gripped without any jerking throughout the entire process.

[0049] It should be noted that the piston assembly 2 includes a return spring 22 and a piston body. When the brake handle 3 is released, under the action of the return spring 22, each component returns to its initial position 8211, waiting for the next braking. Example

[0050] Reference Figures 1-10 Based on the structure of Embodiment 1, this embodiment provides a preferred implementation of the guide mechanism 8, as follows: Reference Figure 10 The guiding mechanism 8 includes a guide wheel 811, a guide wheel connecting shaft 812, a guide shaft 813, and a guide rocker arm 814. The guide wheel 811 is connected to the brake housing 1. Specifically, a guide wheel spindle 815 is provided on the side of the guide wheel 811. The brake housing 1 has a connecting hole 14, and the guide wheel spindle 815 is inserted into the connecting hole 14 to achieve a rotational connection between the guide wheel 811 and the brake housing 1. The guide wheel connecting shaft 812 is connected to the guide wheel 811, and the guide wheel connecting shaft 812 and / or the guide wheel spindle 815 are eccentrically arranged on the guide wheel 811 to form an eccentric transmission structure; the transmission lever 4 has a third transmission hole 43, and the guide shaft 813 is inserted into the third transmission hole 43 to achieve a sliding fit with the transmission lever 4; one end of the guide rocker arm 814 is connected to the guide shaft 813, and the other end of the guide rocker arm 814 is connected to the guide wheel connecting shaft 812, and the guide rocker arm 814 and the guide shaft 813 are arranged perpendicular to each other to ensure effective force transmission.

[0051] Reference Figures 4-7 The braking process in this embodiment is as follows: 1. Initial Braking Trigger and Trajectory Constraint with Low Lever Ratio: When the user squeezes the brake handle 3, causing the output point 4a of the transmission lever 4 to move upward, the transmission lever 4 tends to shift backward (away from the piston chamber 11). At this time, the guide shaft 813 slides within the third transmission hole 43, simultaneously pulling the guide rocker arm 814. The guide rocker arm 814 drives the guide wheel connecting shaft 812, causing the guide wheel 811 to rotate at a small angle around the guide wheel spindle 815. Due to the eccentric design of the guide wheel connecting shaft 812, the rotation of the guide wheel 811 will exert a forward pulling force on the guide shaft 813 through the rocker arm, forcing the transmission lever 4 to move forward as a whole, rather than simply rotating. During this stage, the eccentricity is not fully released, the constraint trajectory of the guide shaft 813 on the transmission lever 4 is gentle, the increase in the lever arm at the input point 4b of the transmission lever 4 is small, and the leverage ratio remains at a low level, ensuring a rapid braking response.

[0052] II. During the braking process, the leverage ratio dynamically increases: As the gripping force of the handle increases and the output point 4a continues to move upward, the rotation angle of the guide wheel 811 increases, the eccentricity of the guide wheel connecting shaft 812 is gradually fully released, and the guide rocker arm 814 pushes the guide shaft 813 to increase the sliding stroke in the third transmission hole 43. At the same time, it drives the guide point 4c of the transmission lever 4 to move forward by an increased amount. The amplitude of the "forward movement + rotation" compound motion of the transmission lever 4 intensifies, the lever arm of the input point 4b (the distance from the guide point 4c to the input point 4b) increases significantly as the guide point 4c moves forward, and the lever arm of the output point 4a (the distance from the guide point 4c to the output point 4a) is relatively shortened. The leverage ratio increases linearly or non-linearly, realizing the amplification of force and providing greater thrust for the push rod assembly 7.

[0053] III. Stable maintenance of large lever ratio at the end of braking: When the guide wheel 811 rotates to the maximum angle and the eccentricity is fully released, the sliding stroke of the guide shaft 813 reaches the limit, and the trajectory constraint on the transmission lever 4 enters a stable state; at this time, the relative positions of the three points of the transmission lever 4 are fixed in the large lever ratio state, and the input point 4b can stably transmit the amplified thrust to ensure that the piston assembly 2 outputs sufficient hydraulic pressure to achieve strong braking.

[0054] The technical advantages of the guide mechanism 8 in this embodiment are: First, strong trajectory controllability: the eccentricity of the eccentric structure can be precisely designed, and the motion trajectory of the transmission lever 4 can be preset, thereby customizing different lever ratio change curves to adapt to the braking requirements of different vehicle models; Second, high transmission smoothness: the sliding fit between the guide shaft 813 and the third transmission hole 43, and the rotational fit of each hinge point, reduce rigid collisions between components and reduce the risk of transmission jamming; Third, compact structure: the combination of the eccentric wheel and the rocker arm has a small volume, which is suitable for narrow installation spaces such as two-wheeled vehicles, and there is no need to add a large slide rail or cam structure.

[0055] Optionally, refer to Figures 4-7 , Figure 10The brake housing 1 is further provided with several gear slots 15; the guide wheel 811 is also provided with a spring stop 16 (preferably a combination of a spring and a positioning steel ball), the spring stop 16 can be engaged into any one of the gear slots 15 to achieve gear positioning of the guide wheel 811 in the initial state (i.e., without squeezing the brake handle 3). Further configured: the guide wheel connecting shaft 812 extends at least partially outside the brake housing 1 and is equipped with a knob 17, the knob 17 responding to user operation; the knob 17 is provided with an indicator protrusion 171, the indicator protrusion 171 being opposite to the spring stop 16, and the indicator protrusion 171 being able to point to any one of the gear slots 15, facilitating user identification of the current lever ratio gear.

[0056] The working principle of gear adjustment is as follows: 1. The user rotates the knob 17 by hand, which drives the guide wheel connecting shaft 812 and the guide wheel 811 to rotate synchronously; 2. During the rotation, the positioning steel ball is squeezed by the edge of the gear slot 15, compresses the spring and disengages from the current gear slot 15, and slides along the surface of the housing; 3. When the knob 17 is rotated to the target gear, the positioning steel ball is inserted into the corresponding gear slot 15 under the action of the spring force, producing a "click" feedback, indicating that the gear switching is complete; 4. The user can confirm the current preset initial lever ratio gear by observing the gear slot 15 pointed to by the indicator protrusion 171 on the knob 17.

[0057] The relationship between gear position and initial lever ratio: Different gear positions of the guide wheel 811 correspond to different initial eccentric positions: When shifting gears, the initial rotation angle of the guide wheel 811 changes, which causes the relative position of the initial eccentricity of the guide wheel connecting shaft 812 to change; The initial eccentric position 8211 determines the initial three-point relative position of the transmission lever 4: Different initial angles of the guide wheel 811 result in different initial positions 8211 of the guide rocker arm 814 driving the guide shaft 813, which in turn changes the initial position 8211 of the guide point 4c of the transmission lever 4, ultimately causing the initial lever arm ratio (initial lever ratio) of the output point 4a and the input point 4b to change.

[0058] The value of the gear shifting structure to the overall braking system: It breaks through the limitations of a single initial lever ratio, allowing users to manually switch gears and preset different initial lever ratios according to riding scenarios (commuting, off-road, heavy load / unloaded) and user abilities (women, children, men), making the brakes more adaptable. At the same time, it retains the core function of dynamic lever ratio change during braking: regardless of the preset gear, when the brake lever 3 is squeezed, the transmission lever 4 will still complete "forward movement + rotation" under the constraint of the guide mechanism 8, realizing a dynamic increase in the lever ratio from the initial value to the peak value, balancing response speed and braking force. Example

[0059] Reference Figures 11-16Based on the structure of Embodiment 1, this embodiment provides another preferred embodiment of the guide mechanism 8, which can be used as an alternative to Embodiment 2. Specifically, the guide mechanism 8 includes a variable guide groove 821 formed on the brake housing 1 and a guide block 822 disposed on the transmission lever 4. The guide block 822 is inserted into the variable guide groove 821 and can move along the variable guide groove 821. The guide block 822 has an initial position 8211 and an end position 8212 in the variable guide groove 821. The variable guide groove 821 is arc-shaped, and the height of the initial position 8211 is higher than the height of the end position 8212.

[0060] The variable guide groove 821 is arc-shaped and has a defined height difference, which is key to achieving the variable lever ratio. Through clever geometric constraints, the transmission lever 4 generates a unique rotational trajectory during movement, thereby changing the lever arm ratio. When the brake handle 3 is squeezed, the first point rises, and because the third point is constrained by the arc-shaped guide groove, it can only move downwards. The transmission lever 4 is forced to rotate around the third point (instantaneous fulcrum), causing the first point to rotate accordingly. The curved characteristics of the arc-shaped guide groove cause the movement trajectory of the third point to form a specific curve, resulting in a non-linear change in the vertical distance (lever arm) between the first and second points.

[0061] The lever ratio adjustment principle in this embodiment is as follows: (Refer to...) Figure 16 During braking, the guide block 822 moves along the variable guide groove 821 from the initial position 8211 to the end position 8212 as the transmission lever 4 moves. Since the variable guide groove 821 is arc-shaped and its height gradually decreases, the position of the guide point 4c changes as the guide block 822 moves, so that the relative distance between the output point 4a and the input point 4b is dynamically adjusted, and the lever ratio changes adaptively with the braking stroke. At the initial position 8211, the lever ratio is the smallest, which is suitable for long-stroke operation at the beginning of braking. At the end position 8212, the lever ratio is the largest, which is suitable for large braking force output at the end of braking, realizing continuous adaptive adjustment of the lever ratio during braking, taking into account both operating comfort and braking effect.

[0062] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the present utility model. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model.

Claims

1. A brake with a variable lever ratio, comprising: Brake housing (1) having piston chamber (11) having a front opening (12) and a rear opening (13); Piston assembly (2), which is movably disposed in the piston chamber (11); Brake handle (3), which is rotatably connected to brake housing (1) via pivot shaft (31); A push rod assembly (7) is disposed at the rear end of the piston assembly (2), and the push rod assembly (7) and the piston assembly (2) form a transmission engagement; Its features are, It also includes: The transmission lever (4) has its front end pivotally connected to the brake handle (3) via the first transmission assembly (5) to form a transmission engagement, and its middle part pivotally connected to the push rod assembly (7) via the second transmission assembly (6) to form a transmission engagement. The guide mechanism (8) is disposed on the brake housing (1) and is connected to the transmission lever (4) to form a transmission engagement; The connection point between the transmission lever (4) and the first transmission component (5) is the input point (4b), the connection point between the transmission lever (4) and the second transmission component (6) is the output point (4a), and the connection point between the transmission lever (4) and the guide mechanism (8) is the guide point (4c). When the guide mechanism (8) changes position, the guide mechanism (8) drives the transmission lever (4) to change position relative to the brake housing (1), so that the relative position of the output point (4a) and the input point (4b) on the transmission lever (4) changes.

2. The brake with a variable lever ratio according to claim 1, characterized in that: The output point (4a), input point (4b), and guide point (4c) are arranged sequentially from front to back.

3. The brake with a variable lever ratio according to claim 2, characterized in that: During the process of the user squeezing the brake handle (3), the transmission lever (4) moves forward, and the input point (4b) rotates around the pivot shaft (31), the output point (4a) rotates around the contact point between the push rod assembly (7) and the piston assembly (2), and the guide point (4c) rotates around the guide mechanism (8).

4. The brake with a variable lever ratio according to any one of claims 1-3, characterized in that: The guiding mechanism (8) includes a guide wheel (811), a guide wheel connecting shaft (812), a guide shaft (813), and a guide rocker arm (814); The guide wheel (811) is connected to the brake housing (1); The guide wheel connecting shaft (812) is connected to the guide wheel (811); The transmission lever (4) is provided with a third transmission hole (43), and the guide shaft (813) is inserted into the third transmission hole (43); One end of the guide rocker arm (814) is connected to the guide shaft (813), and the other end of the guide rocker arm (814) is connected to the guide wheel connecting shaft (812). The guide rocker arm (814) and the guide shaft (813) are arranged perpendicular to each other. The guide wheel connecting shaft (812) and / or guide wheel spindle (815) are eccentrically mounted on the guide wheel (811).

5. The brake with a variable lever ratio according to claim 4, characterized in that: The guide wheel (811) has a guide wheel spindle (815) on its side. The brake housing (1) has a connecting hole (14). The guide wheel spindle (815) is inserted into the connecting hole (14) to achieve a rotational connection between the guide wheel (811) and the brake housing (1).

6. The brake with a variable lever ratio according to claim 4, characterized in that: The brake housing (1) is also provided with several gear slots (15); The guide wheel (811) is also equipped with a spring stop (16), which can be engaged into any one of the gear slots (15).

7. The brake with a variable lever ratio according to claim 6, characterized in that: The guide wheel connecting shaft (812) extends at least partially outside the brake housing (1) and is equipped with a knob (17) that responds to user operation; The knob (17) is provided with an indicator protrusion (171), which is positioned opposite to the spring stop (16), and the indicator protrusion (171) can point to any one of the stop slots (15).

8. The brake with a variable lever ratio according to any one of claims 1-3, characterized in that: The guide mechanism (8) includes a variable guide groove (821) formed on the brake housing (1) and a guide block (822) disposed on the transmission lever (4). The guide block (822) is inserted into the variable guide groove (821) and can move along the variable guide groove (821).

9. The brake with a variable lever ratio according to claim 8, characterized in that: The guide block (822) has an initial position (8211) and an end position (8212) in the variable guide groove (821). The variable guide groove (821) is arc-shaped, and the height of the initial position (8211) of the variable guide groove (821) is higher than the height of the end position (8212).

10. The brake with a variable lever ratio according to any one of claims 1-3, characterized in that: The first transmission assembly (5) includes a drive shaft (51) and a first pivot sleeve (52); the drive shaft (51) is fixed on the brake handle (3), the transmission lever (4) has a first transmission hole (41), the first pivot sleeve (52) is disposed in the first transmission hole (41), and the drive shaft (51) is rotatably inserted into the first pivot sleeve (52); The second transmission assembly (6) includes an output shaft (61), a fastener (62), and a second pivot sleeve (63); the push rod assembly (7) is connected to the output shaft (61), the transmission lever (4) has a second transmission hole (42), the second pivot sleeve (63) is disposed in the second transmission hole (42), the output shaft (61) has a locking hole (611), a part of the fastener (62) is rotatably inserted into the first pivot sleeve (52), and the other part of the fastener (62) is threaded into the locking hole (611) and abuts against the push rod assembly (7); the output shaft (61) and the push rod assembly (7) are arranged perpendicular to each other.

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