Lightweight electric bicycle crossbar multidirectional bending and torsion torque durability test system

Abstract

This invention discloses a lightweight electric bicycle crossframe multi-directional bending torque durability testing system, including a rear crossframe fixing fixture and a multi-directional bending torque durability testing device. The rear crossframe of the folding frame is fixed on the rear crossframe fixing fixture; the head tube at the front end of the front crossframe is mounted on the multi-directional bending torque durability testing device, and the multi-directional bending moment and torque output by the multi-directional bending torque durability testing device are transmitted to the folding part through the head tube and the front crossframe; the durability testing system subjectes the folding part to bending moment and torque in multiple directions without blind spots, thus improving the comprehensiveness of the durability test.

Description

Technical Field

[0001] This invention belongs to the field of durability testing for electric bicycles. Background Technology

[0002] Lightweight electric vehicles have wide applications in scenarios such as in-vehicle electric vehicles and electric bicycles for ride-hailing services; for example Figure 1 As shown, in order to minimize the folded size, the frame of this type of electric bicycle generally includes a separate crossbar. The folding part between the front crossbar and the rear crossbar is connected by a folding structure, and the head tube is fixed separately to the front end of the front crossbar.

[0003] In specific working conditions, the cross frame will be subjected to bending moment due to the up-and-down bouncing of the folding part on bumpy roads, and bending moment due to non-up-and-down bouncing when driving diagonally and turning on slopes. Since lightweight foldable electric vehicles need to be frequently moved to the trunk, the torque situation at the folding part is complex.

[0004] Compared to non-folding bikes, the folding section of lightweight electric bicycles is the most vulnerable part. Bending moments and torques in any direction can cause the folding section to loosen or fall apart. Therefore, it is necessary to design a durability testing system that can subject the folding section to bending moments and torques in multiple directions without blind spots, thereby improving the comprehensiveness of durability testing. Summary of the Invention

[0005] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a lightweight electric bicycle crossbar multi-directional bending torque durability testing system, which enables the folding part to be subjected to bending moment and torque in multiple directions without blind spots, thereby improving the comprehensiveness of durability testing.

[0006] Technical solution: To achieve the above objectives, the present invention provides a lightweight electric bicycle frame multi-directional bending torque durability testing system. The lightweight electric bicycle frame includes a folding frame, which includes a front frame and a rear frame. The folding part between the front frame and the rear frame is connected by a folding structure. A head tube is fixedly connected to the front end of the front frame.

[0007] It includes a rear crossbar fixing fixture and a multi-directional bending torque durability testing device. The rear crossbar of the lightweight electric bicycle frame is fixed on the rear crossbar fixing fixture. The head tube at the front end of the front crossbar is installed on the multi-directional bending torque durability testing device. The multi-directional bending moment and torque output by the multi-directional bending torque durability testing device are transmitted to the folding part through the head tube and the front crossbar.

[0008] Furthermore, the multi-directional bending torque durability testing device includes an output shaft driven by a motor, and a rotating drive ring coaxial with the output shaft. The outer wall of the rotating drive ring is synchronously connected to the output shaft through several synchronous arms. A radial runout ring is coaxially arranged on the inner side of the rotating drive ring. The outer wall of the radial runout ring and the inner wall of the rotating drive ring are elastically connected by several support springs arranged in a circumferential array.

[0009] Furthermore, a radial beam is fixedly connected to one side of the radial runout ring along the diameter direction, and a sleeve coaxial with the radial runout ring is fixedly connected to the middle of the radial beam. A torque transmission cylinder is installed inside the sleeve through several bearings and rotates coaxially. A cylindrical synchronous cover is vertically fixedly connected to one end of the torque transmission cylinder. A bayonet is provided on one side of the cylindrical synchronous cover. The cylindrical synchronous cover is coaxial with the outside of the head tube, and the bayonet locks the front crossbar.

[0010] Furthermore, an insertion post is coaxially provided on the inner side of the cylindrical synchronization cover. The upper end of the insertion post is fixedly connected to the top wall of the cylindrical synchronization cover, and the insertion post is inserted downwards coaxially into the head tube channel inside the head tube.

[0011] Furthermore, the bottom end of the insertion column has a threaded hole and also includes a locking bolt. When the locking bolt is locked into the threaded hole, the bolt head of the locking bolt presses against the lower end face of the head tube.

[0012] Furthermore, within the enclosure of the radially running ring, a floating permanent magnet column is arranged in the radial direction. Several constraint rods are distributed in a circular array around the outer periphery of the floating permanent magnet column. The constraint rods are made of non-magnetic materials such as aluminum alloy. Under the constraint of the several constraint rods distributed in a circular array, the floating permanent magnet column can only slide along the axial direction. Both ends of the constraint rods are fixed to the inner wall of the radially running ring.

[0013] Furthermore, springs a and b are respectively provided on both ends of the floating permanent magnet column with elastic pressure on the axis. Under the combined action of springs a and b, the floating permanent magnet column tends to move towards the central area within the radial jumping ring range. Several constraint rods distributed in a circular array are fitted with electromagnetic induction coils. When the electromagnetic induction coils are energized, the magnetic field generated by the electromagnetic induction coils can drive the floating permanent magnet column to move along the axial direction.

[0014] Furthermore, the torque transmission cylinder has a nut movable channel with an inner contour of regular hexagon. The inner wall of the end of the nut movable channel that connects to the outside is provided with a limiting inner edge. A torque transmission nut with an outer contour of regular hexagon is coaxially arranged in the middle of the nut movable channel. The torque transmission nut can move along the length of the nut movable channel. The torque transmission nut has an external thread torque transmission column that is threaded into its internal thread. The end of the external thread torque transmission column away from the cylindrical synchronous cover is fixed to the radial beam by a fastener.

[0015] Beneficial effects: During the slow clockwise rotation of the radial runout ring along the axis of the present invention, the axial direction of the floating permanent magnet column also changes, thereby causing the direction of the bending moment of the back-and-forth bounce on the folded part to change accordingly. This results in the folded part being subjected to bending moments in multiple directions without dead angles, improving the comprehensiveness of the durability test. At the same time, in a "test cycle", the folded part of the lightweight electric bicycle frame is subjected to bending moment impacts in multiple directions, clockwise torque, and counterclockwise torque.

[0016] The support spring allows torque to be transmitted between the radial runout ring and the rotary drive ring, while maintaining a relatively independent, non-rigid connection. Radial fluctuations on the radial runout ring are not rigidly transmitted to the rotary drive ring, thus preventing the radial fluctuations generated on the radial runout ring from being consumed by the rotary drive ring and thus not being transmitted to the folding part. Attached Figure Description

[0017] Appendix Figure 1 Schematic diagram of a lightweight folding electric bicycle frame;

[0018] Appendix Figure 2 A schematic diagram of a lightweight folding electric bicycle frame fixture on a testing system;

[0019] Appendix Figure 3 This is a first-view schematic diagram of a multi-directional bending torque durability testing device.

[0020] Appendix Figure 4 This is a second-view schematic diagram of a multi-directional bending torque durability testing device.

[0021] Appendix Figure 5 For the appendix Figure 4 A disassembly diagram of the cylindrical synchronization cover based on the above;

[0022] Appendix Figure 6 For the appendix Figure 5 The schematic diagram behind the torque transmission cylinder has been omitted from the original design.

[0023] Appendix Figure 7 For the appendix Figure 6 An enlarged view of mark 19;

[0024] Appendix Figure 8 Appendix Figure 4 A sectional view;

[0025] Appendix Figure 9 For the appendix Figure 8 An enlarged view of mark 35;

[0026] Appendix Figure 10 This is a cross-sectional view of the torque transmission cylinder. Detailed Implementation

[0027] The invention will now be further described with reference to the accompanying drawings.

[0028] As attached Figures 1 to 10 The lightweight electric bicycle crossbar multi-directional bending torque durability testing system shown is as follows: Figure 1 The bicycle includes a lightweight electric bicycle frame 43, which includes a folding crossbar. The folding crossbar includes a front crossbar 3 and a rear crossbar 17. The folding part 18 between the front crossbar 3 and the rear crossbar 17 is connected by a folding structure. The front end of the front crossbar 3 is fixedly connected to the head tube 7.

[0029] This solution provides a rear crossbar fixing fixture and a multi-directional bending torque durability testing device. The rear crossbar 17 of the lightweight electric bicycle frame 43 is fixed on the rear crossbar fixing fixture. The testing requirements only require the rear crossbar 17 to be fully fixed; therefore, the specific structure of the rear crossbar fixing fixture is not provided in this paper. The head tube 7 at the front end of the front crossbar 3 is mounted on the multi-directional bending torque durability testing device. The multi-directional bending moment and torque output by the multi-directional bending torque durability testing device are transmitted to the folding part 18 through the head tube 7 and the front crossbar 3. The specific solution and structure of the multi-directional bending torque durability testing device are as follows:

[0030] like Figure 2 , 3 4; The multi-directional bending torque durability testing device includes an output shaft 28 driven by a motor, and a rotating drive ring 26 coaxial with the output shaft 28. The outer wall of the rotating drive ring 26 is synchronously connected to the output shaft 28 through several synchronous arms 29. A radial runout ring 25 is coaxially arranged on the inner side of the rotating drive ring 26. The outer wall of the radial runout ring 25 and the inner wall of the rotating drive ring 26 are elastically connected by several support springs 71 arranged in a circumferential array. The support springs 71 enable the radial runout ring 25 and the rotating drive ring 26 to transmit torque while maintaining a relatively independent non-rigid connection. The radial fluctuations on the radial runout ring 25 are not rigidly transmitted to the rotating drive ring 26. This avoids the radial fluctuations generated on the radial runout ring 25 being consumed by the rotating drive ring 26 and unable to be transmitted to the folding part 18. The specific process will be described later.

[0031] like Figure 5A radial beam 10 is fixedly connected to one side of the radial runout ring 25 along the diameter direction. A sleeve 8, coaxial with the radial runout ring 25, is fixedly connected to the middle of the radial beam 10. A torque transmission cylinder 9 is coaxially rotatable inside the sleeve 8 via several bearings 34. A cylindrical synchronous cover 12 is vertically fixedly connected to one end of the torque transmission cylinder 9. A bayonet 13 is provided on one side of the cylindrical synchronous cover 12. The cylindrical synchronous cover 12 is coaxial with the outside of the head tube 7, and the bayonet 13 locks the front cross tube. Frame 3; An insertion post 11 is coaxially arranged on the inner side of the cylindrical synchronization cover 12. The upper end of the insertion post 11 is fixedly connected to the top wall of the cylindrical synchronization cover 12. The insertion post 11 is inserted downward coaxially into the head tube channel 6 inside the head tube 7. The bottom end of the insertion post 11 has a threaded hole 14 and also includes a locking bolt 4. When the locking bolt 4 is locked into the threaded hole 14, the bolt head 5 of the locking bolt 4 presses against the lower end face of the head tube 7, thereby realizing the mutual fixation of the cylindrical synchronization cover 12 and the head tube 7.

[0032] like Figure 6 Within the enclosure of the radial runout ring 25, a floating permanent magnet column 20 is arranged radially, such as... Figure 9 The floating permanent magnet column 20 has several constraint rods 2 arranged in a circular array around its outer periphery. These constraint rods 2 are made of non-magnetic materials such as aluminum alloy. Under the constraint of these circularly arranged constraint rods 2, the floating permanent magnet column 20 can only slide along its axial direction. Both ends of each constraint rod 2 are fixed to the inner wall of a radially vibrating ring 25. Springs a 1.1 and b 1.2 are respectively provided coaxially and elastically pressing against the ends of the floating permanent magnet column 20. Under the combined action of springs a 1.1 and b 1.2, the floating permanent magnet column 20 tends to move towards the central region within the area enclosed by the radially vibrating ring 25. An electromagnetic induction coil 21 is fitted around the circularly arranged constraint rods 2. When the electromagnetic induction coil 21 is energized, the magnetic field generated by the electromagnetic induction coil 21 drives the floating permanent magnet column 20 to move along its axial direction. During operation, the electromagnetic induction coil 21 periodically generates alternating induced magnetic fields in the form of pulses. Under the action of the alternating magnetic fields generated by the electromagnetic induction coil 21, the floating permanent magnet column 20 exhibits periodic back-and-forth linear oscillation motion along its axial direction. Springs a1.1 and b1.2 periodically extend and compress, causing the radially oscillating ring 25 to exhibit radial fluctuations and back-and-forth oscillations along the axis of the floating permanent magnet column 20. The radial fluctuations generated by the radially oscillating ring 25 along the axis of the floating permanent magnet column 20 are ultimately transmitted to the folding portion 18 of the lightweight electric bicycle frame 43 through the formation of the bending moment of the back-and-forth oscillations; thereby subjecting the folding portion 18 of the lightweight electric bicycle frame 43 to the bending moment of the back-and-forth oscillations.

[0033] The torque transmission cylinder 9 contains a nut movable channel 15 with an inner hexagonal outline. A limiting inner edge 16 is provided on the inner wall of one end of the nut movable channel 15 that communicates with the outside. A torque transmission nut 22 with an outer hexagonal outline is coaxially positioned in the center of the nut movable channel 15. The torque transmission nut 22 can move along the length of the nut movable channel 15. An externally threaded torque transmission post 24 is threaded into the internal thread of the torque transmission nut 22. The end of the externally threaded torque transmission post 24 away from the cylindrical synchronous cover 12 is fixed to the radial beam 10 by a fixing member 23. Figure 7 , 9 As shown in Figure 10; in the specific working process: if the clockwise rotating external thread torque transmission column 24 drives the torque transmission nut 22 to slide forward within the nut movable channel 15 under thread transmission, during the forward sliding of the torque transmission nut 22 within the nut movable channel 15, there is basically no torque transmission between the external thread torque transmission column 24 and the torque transmission nut 22. After the radial runout ring 25 rotates clockwise a predetermined number of times along the axis, the torque transmission nut 22 has just slid forward to the front end of the nut movable channel 15. At this point, the torque transmission nut 22 cannot continue to move forward. At this time, the external thread torque transmission column 24 transmits the clockwise torque from the output shaft 28 to the nut 22. The nut 22 transmits the clockwise torque to the torque transmission cylinder 9, and finally to the folding part 18 of the lightweight electric bicycle frame 43. If the external thread torque transmission column 24 rotates counterclockwise, it drives the torque transmission nut 22 to slide backward in the nut movable channel 15 under threaded transmission. During the backward sliding of the torque transmission nut 22 in the nut movable channel 15, there is basically no torque transmission between the external thread torque transmission column 24 and the torque transmission nut 22. After the radial runout ring 25 rotates counterclockwise a predetermined number of times along the axis, the torque transmission nut 22 just slides backward to the rear end of the nut movement channel 15. At this time, the torque transmission nut 22 can no longer move backward. At this time, the external thread torque transmission column 24 transmits the counterclockwise torque from the output shaft 28 to the nut 22. The nut 22 transmits the counterclockwise torque to the torque transmission cylinder 9, and finally to the folding part 18 of the lightweight electric bicycle frame 43.

[0034] Working principle:

[0035] Tooling process: Fix the rear crossbar 17 of the lightweight electric bicycle frame 43 to the rear crossbar fixing fixture; at the same time, install the head tube 7 at the front end of the front crossbar 3 inside the cylindrical synchronous cover 12 of the multi-directional bending torque durability test device, and let the locking bolt 4 be locked into the threaded hole 14, so that the bolt head 5 of the locking bolt 4 presses against the lower end face of the head tube 7, thereby achieving mutual fixation between the cylindrical synchronous cover 12 and the head tube 7;

[0036] A "testing cycle":

[0037] The electromagnetic induction coil 21 periodically generates an alternating induced magnetic field in the form of pulses. Under the action of the alternating magnetic field generated by the electromagnetic induction coil 21, the floating permanent magnet column 20 periodically oscillates back and forth in a linear motion along the axial direction. Springs a1 and b1.2 periodically extend and compress, thereby causing the radial jumping ring 25 to generate radial fluctuations and a back-and-forth jumping tendency along the axial direction of the floating permanent magnet column 20. The radial fluctuations generated by the radial jumping ring 25 along the axial direction of the floating permanent magnet column 20 are ultimately transmitted to the folding part 18 of the lightweight electric bicycle frame 43 through the formation of the back-and-forth jumping bending moment; thus, the folding part 18 of the lightweight electric bicycle frame 43 is subjected to the back-and-forth jumping bending moment.

[0038] At the same time, the output shaft 28 drives the rotary drive ring 26 to rotate slowly clockwise. Under the drive of the support spring 71, the radial runout ring 25 also rotates slowly clockwise along the axis. During the slow clockwise rotation of the radial runout ring 25 along the axis, the axial direction of the floating permanent magnet column 20 also changes, which causes the direction of the bending moment of the back-and-forth jumping of the folded part 18 to change, so that the folded part 18 is subjected to bending moments in multiple directions without dead angles, thus improving the comprehensiveness of the durability test.

[0039] Meanwhile, as the radial runout ring 25 slowly rotates clockwise along the axis, the external thread torque transmission column 24, which rotates clockwise, drives the torque transmission nut 22 to slide forward within the nut movable channel 15 under the threaded transmission. During the forward sliding of the torque transmission nut 22 within the nut movable channel 15, there is basically no torque transmission between the external thread torque transmission column 24 and the torque transmission nut 22. After the radial runout ring 25 rotates clockwise along the axis a predetermined number of times, the torque transmission nut 22 has just slid forward to the front end of the nut movable channel 15. At this time, the torque transmission nut 22 cannot continue to move forward. At this time, the external thread torque transmission column 24 transmits the clockwise torque from the output shaft 28 to the nut 22. The nut 22 transmits the clockwise torque to the torque transmission cylinder 9 and finally to the folding part 18 of the lightweight electric bicycle frame 43.

[0040] After the folding part 18 of the lightweight electric bicycle frame 43 is subjected to a clockwise torque, the output shaft 28 begins to output counterclockwise rotation, causing the originally clockwise rotating radial runout ring 25 to slowly rotate counterclockwise along the axis. The externally threaded torque transmission column 24, rotating counterclockwise, drives the torque transmission nut 22 to slide backward within the nut movement channel 15 under threaded transmission. During the backward sliding of the torque transmission nut 22 within the nut movement channel 15, there is essentially no torque transmission between the externally threaded torque transmission column 24 and the torque transmission nut 22. After the radial runout ring 25 rotates counterclockwise a predetermined number of times along the axis, the torque transmission nut 22 just slides backward to the rear end of the nut movement channel 15. At this point, the torque transmission nut 22 cannot continue to move backward. At this time, the external thread torque transmission column 24 transmits the counterclockwise torque from the output shaft 28 to the nut 22. The nut 22 transmits the counterclockwise torque to the torque transmission cylinder 9, and finally to the folding part 18 of the lightweight electric bicycle frame 43; so that the folding part 18 of the lightweight electric bicycle frame 43 is subjected to a counterclockwise torque; thus, one "test cycle" is completed.

[0041] During a “test cycle”, the folding portion 18 of the lightweight electric bicycle frame 43 is subjected to bending moment impacts in multiple directions, clockwise torque, and counterclockwise torque.

[0042] The "test cycle" is repeated periodically, subjecting the folding part 18 of the lightweight electric bicycle frame 43 to bending moment impacts, clockwise torque, and counterclockwise torque in multiple directions. If the folding part 18 of the lightweight electric bicycle frame 43 does not fall apart when the predetermined number of cycles is reached (falling apart includes the folding structure of the folding part 18 being released from its locked state), then the durability test of the folding part 18 of the frame 43 is considered passed.

[0043] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A lightweight electric bicycle frame multi-directional bending torque durability test system, wherein the lightweight electric bicycle frame (43) includes a folding frame, the folding frame includes a front frame (3) and a rear frame (17), the folding part (18) between the front frame (3) and the rear frame (17) is connected by a folding structure; the front end of the front frame (3) is fixedly connected to a head tube (7). Its features are: Includes a rear crossbar fixing fixture and a multi-directional bending torque durability testing device. The rear crossbar (17) of the lightweight electric bicycle frame (43) is fixed on the rear crossbar fixing fixture. The head tube (7) at the front end of the front crossbar (3) is installed on the multi-directional bending torque durability testing device. The multi-directional bending moment and torque output by the multi-directional bending torque durability testing device are transmitted to the folding part (18) through the head tube (7) and the front crossbar (3). The multi-directional bending torque durability test device includes a rotary drive ring (26), and a radial runout ring (25) is coaxially arranged on the inner side of the rotary drive ring (26). The outer wall of the radial runout ring (25) and the inner wall of the rotary drive ring (26) are elastically connected by a number of support springs (71) arranged in a circumferential array. A radial beam (10) is fixed along the diameter direction on one side of the radial runout ring (25). A sleeve (8) coaxial with the radial runout ring (25) is fixedly connected to the middle of the radial beam (10). A torque transmission cylinder (9) rotates coaxially inside the sleeve (8). A cylindrical synchronous cover (12) is vertically fixed to one end of the torque transmission cylinder (9). A bayonet (13) is provided on one side of the cylindrical synchronous cover (12). The cylindrical synchronous cover (12) is coaxial with the outside of the head tube (7), and the bayonet (13) locks the front crossbar (3). Within the enclosure of the radially oscillating ring (25), a floating permanent magnet column (20) is arranged radially. Several constraint rods (2) are arranged in a circular array around the outer periphery of the floating permanent magnet column (20). Under the constraint of the several constraint rods (2) arranged in a circular array, the floating permanent magnet column (20) can only slide along the axial direction. Both ends of the constraint rods (2) are fixed to the inner wall of the radially oscillating ring (25). Both ends of the floating permanent magnet column (20) are respectively provided with a spring (1.1) and a spring (1.2) elastically pressing on the coaxial sides. Under the combined action of the springs (1.1) and (1.2), the floating permanent magnet column (20) tends to the central area within the enclosure of the radially oscillating ring (25). The constraint rods (2) arranged in a circular array are covered with an electromagnetic induction coil (21). When the electromagnetic induction coil (21) is energized, the magnetic field generated by the electromagnetic induction coil (21) can drive the floating permanent magnet column (20) to move along the axial direction. The torque transmission cylinder (9) has a nut movable channel (15) with an inner contour of regular hexagon. The inner wall of the end of the nut movable channel (15) that is connected to the outside is provided with a limiting inner edge (16). A torque transmission nut (22) with an outer contour of regular hexagon is coaxially arranged in the middle of the nut movable channel (15). The torque transmission nut (22) can move along the length direction of the nut movable channel (15). The torque transmission nut (22) has an internal thread that is engaged with an external thread torque transmission column (24). The end of the external thread torque transmission column (24) away from the cylindrical synchronous cover (12) is fixed to the radial beam (10) by a fixing member (23).

2. The lightweight electric bicycle crossbar multi-directional bending torque durability testing system according to claim 1, characterized in that: An insertion post (11) is coaxially arranged on the inner side of the cylindrical synchronization cover (12). The upper end of the insertion post (11) is fixedly connected to the top wall of the cylindrical synchronization cover (12). The insertion post (11) is inserted downwards coaxially into the head tube channel (6) inside the head tube (7).

3. The lightweight electric bicycle crossbar multi-directional bending torque durability testing system according to claim 2, characterized in that: The bottom end of the insertion post (11) has a threaded hole (14) and also includes a locking bolt (4). When the locking bolt (4) is locked into the threaded hole (14), the bolt head (5) of the locking bolt (4) presses against the lower end face of the head tube (7).

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