Goods bearing frame with adjustable gravity center for cargo carrying bicycle or electric vehicle and control method

Abstract

The invention discloses a gravity-center-adjustable cargo bearing frame for a cargo-carrying bicycle or an electric vehicle and a control method for the gravity center of cargoes during riding. The bearing frame comprises a foldable goods conversion frame, a goods bearing assembly, a middle vertical bearing loading system, an adjustable gravity center controller and a bandage system. The middle vertical bearing loading system is vertically arranged in the center of the goods bearing assembly and comprises a middle vertical shaft and a weight transfer mechanism. The adjustable gravity center controller comprises a movable upper arm capable of rotating up and down around a hinge point, an adjusting mechanism used for pushing the movable upper arm to be lifted upwards, and a center hanging scaffold self-adaptive device hung at the front end of the movable upper arm. One ends of a plurality of bandages of the bandage system are fixed on the peripheral surface of the tray, and the other ends of the bandages are connected to bandage fixing points of the central hanging scaffold. The movable upper arm is pushed to ascend through the adjusting mechanism, the center hanging scaffold moves upwards, the binding belt is tightened, the weight of goods is transferred to the middle vertical bearing loading system from the goods bearing assembly, and the gravity center of the goods is closer to the center axis of the frame.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cargo carrying device of cargo carrying bicycle or electric bicycle, and particularly relates to a gravity-adjustable cargo carrying rack for cargo carrying bicycle or electric bicycle and a method for controlling cargo gravity during riding. BACKGROUND

[0002] As a kind of green and environmental protection short-distance transport tool, cargo carrying bicycle or electric bicycle has been more and more widely applied in the scenes of urban logistics distribution, daily shopping and family travel. Compared with ordinary bicycle, cargo carrying bicycle needs to carry heavier cargo, so higher requirements are put forward for the stability, carrying capacity and control performance of the vehicle.

[0003] The existing cargo carrying bicycle usually adopts fixed rack structure, and the cargo is directly placed on the rack at the front or rear of the frame and is simply fixed by a strap or a cargo box. For example, US patent US11260928B2 discloses a cargo carrying bicycle, which includes a wheel, a front fork, a handlebar, a seat tube, a head tube, a down tube and other components, and a cargo carrying structure is arranged on the frame. Although this traditional cargo carrying bicycle structure can meet the basic cargo carrying demand, it still has the following shortcomings in actual use: Firstly, the gravity center position of the cargo of the existing cargo carrying bicycle is fixed and cannot be adjusted according to the actual riding demand. When carrying heavy cargo, the gravity center of the cargo often deviates from the central axis of the frame, causing the gravity center of the vehicle to be unstable during riding, and left-right swinging or front-back tilting is easy to occur, increasing the difficulty and safety risk of riding, especially when turning, accelerating or braking, the gravity center deviation problem is more prominent.

[0004] Secondly, the traditional fixed rack structure bears the weight of the cargo completely by the rack, and the connection point between the rack and the frame bears large bending moment and shear force, which is easy to cause fatigue damage of the connection part after long-term use. At the same time, since the weight of the cargo is concentrated in a local position of the frame, the carrying capacity of the whole frame cannot be fully utilized, which limits the further improvement of the carrying capacity.

[0005] Thirdly, the existing strap fixing method is complicated to operate, and the strap needs to be manually tied and untied one by one, which is time-consuming and laborious, and reduces the efficiency of cargo loading and unloading. The strap is often hung on the outside of the rack when not in use, which not only affects the appearance, but also has the safety hidden danger of being rolled into the wheel or hung on the obstacle during riding.

[0006] In addition, for irregularly shaped or unevenly distributed gravity center cargo, the traditional fixing method is difficult to realize the self-adaptive adjustment of the gravity center position of the cargo, and the cargo is easy to deviate or tilt during transportation, affecting the riding stability.

[0007] Therefore, a cargo carrying device for cargo carrying bicycle or electric vehicle capable of dynamically adjusting the center of gravity of the cargo, simple operation, safe and reliable is needed to solve the above problems in the prior art and improve the stability, safety and convenience of cargo carrying riding. SUMMARY

[0008] The present application aims to provide a center-of-gravity-adjustable cargo carrying frame for cargo carrying bicycle or electric vehicle to solve the technical problem that the center of gravity of the cargo is fixed and cannot be adjusted according to the riding requirements, resulting in poor riding stability and low safety in the prior art.

[0009] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A center-of-gravity-adjustable cargo carrying frame for cargo carrying bicycle or electric vehicle, comprising a foldable cargo conversion frame, a cargo supporting assembly and a binding system, further comprising: a middle vertical shaft load bearing system vertically arranged at the center position of the cargo supporting assembly for bearing part of the weight of the cargo, the middle vertical shaft load bearing system comprising a middle vertical shaft and a weight transfer mechanism, the lower end of the middle vertical shaft being fixedly connected to the frame, the weight transfer mechanism being arranged at the upper part of the middle vertical shaft and comprising a cantilever; an adjustable center-of-gravity controller arranged on the weight transfer mechanism, the adjustable center-of-gravity controller comprising a movable upper arm rotatable up and down about a hinge point, an adjusting mechanism for pushing the movable upper arm upward, and a center hanging plate adaptive device suspended at the front end of the movable upper arm, the center hanging plate adaptive device comprising a center hanging plate with binding fixed points arranged around the center hanging plate; the binding system comprises a plurality of bindings, one end of each binding being fixed to the outer peripheral surface of the tray of the cargo supporting assembly, and the other end being connected to the binding fixed points of the center hanging plate for wrapping and fixing the cargo. By adjusting the mechanism to push the movable upper arm upward, the center hanging plate is moved upward, the bindings are tightened, and the weight of the cargo is transferred from the cargo supporting assembly to the middle vertical shaft load bearing system, thereby achieving dynamic adjustment of the center of gravity of the cargo.

[0010] Preferably, the connecting mechanism of the center hanging plate adaptive device is a ball-and-socket universal hinge structure comprising a ball head connecting seat fixed at the front end of the movable upper arm and a ball-and-socket connecting piece rotatably sleeved on the ball head connecting seat, the lower part of the ball-and-socket connecting piece being fixedly connected to the center hanging plate, and the inner cavity of the ball-and-socket connecting piece being provided with a spherical surface matched with the outer surface of the ball head connecting seat, so that the center hanging plate can rotate in the horizontal plane and swing in the vertical direction, thereby automatically adjusting the posture according to the actual center of gravity position of the cargo and keeping the center of gravity of the cargo stable.

[0011] Further preferably, the inner wall of the ball socket connector is provided with a circular arc guide groove, which cooperates with the guide protrusion on the outer surface of the ball head connector seat to play a guiding and limiting role; the circumference of the ball head connector seat is provided with a limiting stopper, when the swing angle of the center lifting tray reaches a preset range, the ball socket connector abuts against the limiting stopper to prevent excessive deflection, thereby ensuring the structural stability and safety of the device.

[0012] Preferably, the adjusting mechanism comprises a fixed lower arm and an adjusting knob, the fixed lower arm is fixedly installed at the lower part of the middle vertical shaft and corresponds to the movable upper arm in an up-down relationship; the adjusting knob is rotatably installed on the movable upper arm, and by rotating it, the lower end gradually extends and abuts against the fixed lower arm, thereby pushing the movable upper arm to rotate upward. This adjusting mode is simple to operate, and the transfer of the weight of the goods and the adjustment of the center of gravity can be realized by simply rotating.

[0013] Preferably, the outer periphery of the center lifting tray is provided with a plurality of binding strap fixing holes, and a quick locking mechanism is installed at each binding strap fixing hole. The quick locking mechanism makes the fixing and unfixing of the binding strap more convenient and efficient, significantly improves the efficiency of loading and unloading goods compared with the traditional knot tying method, and ensures firm and reliable fixation.

[0014] Preferably, the binding strap system comprises a telescopic binding strap assembly arranged in the internal space of the tray, which comprises a plurality of rigid rods, a plurality of elastic bands and a plurality of binding straps. The rigid rods are arranged around the inner periphery of the tray at equal intervals. The elastic bands are arranged corresponding to each rigid rod and around the outer periphery of the tray. The number of binding straps matches that of the rigid rods and elastic bands. One end of each binding strap is fixed to the outer end of the corresponding rigid rod, and the free end of each binding strap is wound between the corresponding rigid rod and elastic band to form a storage state. When the binding strap is pulled out, the elastic band moves inward to the rigid rod, and the binding strap is released from the storage state. When the binding strap is loosened, the elastic band rebounds outward due to its own elastic restoring force, and drives the binding strap to automatically retract to the storage state. This design realizes the functions of automatic storage and rapid expansion of the binding strap, avoids the situation of scattered and dragging binding strap, keeps the device clean and beautiful, and prevents the safety hazards caused by the binding strap being rolled into the wheel or hung on the obstacle during cycling.

[0015] Further preferably, the bottom of the tray is provided with a long slot corresponding to the position of each binding strap, and an elastic cover is arranged in the long slot. One side of the elastic cover is fixed to one side edge of the long slot, and the other side is a free end. In the natural state, the elastic cover covers and closes the long slot to prevent dust, rainwater and other foreign matters from entering the internal space of the tray. When the binding strap is pulled out, the elastic cover opens, and the binding strap extends out of the tray through the long slot. When the binding strap is retracted, the elastic cover automatically returns to the covering state. This design not only ensures the smoothness of the binding strap pulling and retracting, but also effectively protects the binding strap assembly in the internal space of the tray.

[0016] Preferably, the weight transfer mechanism further comprises a vertical shaft bearing seat, the cantilever can rotate around the axis of the middle vertical shaft in the horizontal direction, the vertical shaft bearing seat is provided with a cantilever force applying mechanism, the cantilever force applying mechanism is used for driving the cantilever to swing left and right to adjust the position of the center of gravity of the goods in the turning direction. Through this active center of gravity adjustment mechanism, the center of gravity of the goods is offset to the inside of the turning when the vehicle turns, generating a balance moment opposite to the direction of the overturning moment caused by the centrifugal force, effectively offsetting the instability of the centrifugal force, making the vehicle keep a better balance state during turning, and reducing the risk of rollover.

[0017] Preferably, the cantilever force applying mechanism comprises a motor fixedly installed on the side wall of the vertical shaft bearing seat, a drive gear connected to the output shaft of the motor, and a driven gear fixed to the hinged end of the cantilever, the drive gear and the driven gear are meshed with each other, and the motor drives the cantilever to swing left and right through gear transmission. The rider can operate the motor through the control button or the lever installed on the handlebar to realize active adjustment of the center of gravity of the goods in the turning direction.

[0018] Alternatively, the cantilever force applying mechanism comprises a left side cable and a right side cable, one end of the left side cable is fixed to the left side of the cantilever, one end of the right side cable is fixed to the right side of the cantilever, and the left side cable and the right side cable are guided upwards along the middle vertical shaft to the handlebar position, a cable control handle is arranged on the handlebar, and the cantilever is driven to swing left and right by pulling the cable control handle. This purely mechanical cable control system does not need power driving, has simple and reliable structure, and is intuitive to operate.

[0019] Compared with the prior art, the present application has the following advantages: Dynamic adjustment of the center of gravity of the goods: through the adjustable center of gravity controller, the weight of the goods can be transferred from the goods bearing assembly to the middle vertical shaft bearing weight system according to actual needs, so that the center of gravity of the goods is closer to the central axis of the frame, the stability and safety of riding are significantly improved, and the instability risk of the vehicle caused by the deviation of the center of gravity of the goods is reduced.

[0020] Self-adaptive function of the central hanging disc: the self-adaptive device of the central hanging disc adopts a ball and socket universal joint structure, which can automatically adjust the posture according to the actual center of gravity position of the goods, so that the center of gravity of the goods remains stable even during the weight transfer process, and the risk of overturning caused by the deviation of the center of gravity is avoided.

[0021] Simple and efficient operation: the weight transfer and center of gravity adjustment can be realized through the simple rotation operation of the adjusting knob, the quick locking mechanism makes the fixing and unfixing of the binding belt more convenient, the automatically stored binding belt assembly avoids the trouble of manual winding and arranging, the overall operation process is simple and fast, and the efficiency of loading and unloading and transporting goods is improved.

[0022] Active stability control during turning: the dynamic matching adjustment of the center of gravity of the goods in the turning direction is realized through the cantilever force applying mechanism, the center of gravity of the goods is actively offset to the inside of the turning during the turning of the vehicle, the influence of the centrifugal force is effectively offset, and the stability and safety during turning are greatly improved.

[0023] Compact and beautiful structure: the retractable binding assembly is arranged inside the tray, is automatically stored when not in use, keeps the appearance of the device clean, and prevents the binding from being rolled into the wheel or hung on the obstacle during riding, thereby causing a safety hazard.

[0024] Strong adaptability: the foldable goods conversion frame is convenient for storage and transportation, and the center lifting tray self-adaptive device can adapt to goods of irregular shapes and different center of gravity distribution, and has a wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic diagram of the overall structure of the center of gravity adjustable goods carrying rack of embodiment 1 in the unfolded state mounted on the cargo carrying bicycle; Figure 2 is a schematic diagram of the main structure of the center of gravity adjustable goods carrying rack of embodiment 1; Figure 3 is a partial enlarged schematic diagram of the foldable goods conversion frame and the central folding hinge of embodiment 1; Figure 4 is a schematic diagram of the connection relationship between the binding system and the center lifting tray of embodiment 1; Figure 5 is a schematic diagram of the structure of the adjustable center of gravity controller of embodiment 1; Figure 6 is a comparative schematic diagram of the weight transfer mechanism of embodiment 1 in two different working states; Figure 7 is a top view of the distribution of the long slot at the bottom of the tray of embodiment 2; Figure 8 is a schematic diagram of the structure of the retractable binding assembly inside the tray of embodiment 2 (enlarged at A); Figure 7 Figure 9 is a partial enlarged schematic diagram of the cooperation relationship between the elastic cover and the long slot of embodiment 2; Figure 10 is a schematic diagram of the overall structure of the center of gravity adjustable goods carrying rack of embodiment 4 in the folded state mounted on the cargo carrying bicycle; Figure 11 is a partial enlarged schematic diagram of the folding locking mechanism of embodiment 4 (enlarged at B). Figure 10

[0026] Reference signs: ​​Foldable cargo conversion frame 100, central vertical bearing load system 200, adjustable center of gravity controller 230, cargo support assembly 300, strap system 400, main frame 01, front fork 011, handlebars 012, seat post 013, head tube 014, down tube 015, symmetrical folding arm 110, central folding hinge 120, folding locking mechanism 130, compression spring 131, locking seat 132, guide rod 133, central vertical shaft 210, weight transfer mechanism 220, vertical bearing carrier 221, cantilever 222, center plate 223, movable upper arm 231, fixed lower arm 232, center plate adaptive device 233, adjustment knob 234, pallet 320, long slot 321, elastic cover 322, strap 401, elastic band 510, rigid rod 520. Detailed Implementation Example

[0027] like Figures 1-2 As shown, this embodiment provides a center-of-gravity adjustable cargo carrier for cargo bicycles or electric vehicles, which mainly includes: a foldable cargo conversion frame 100 as the main bearing body, a cargo support component 300 set at the bottom of the foldable cargo conversion frame 100 and forming an initial cargo placement platform, a central vertical bearing load system 200 vertically set at the center of the cargo support component 300 to bear part of the cargo weight and cooperate to realize weight adjustment and transfer, an adjustable center-of-gravity controller 230 set at the upper part of the central vertical bearing load system 200 to adjust the center of gravity of the cargo, and a strap system 400 mainly set in the cargo support component 300. The strapping system 400 includes multiple straps 401, each evenly distributed on the outer periphery of the pallet 320 in the cargo support assembly 300. These straps are retractable and converge towards the center, with their ends engaging with the central vertical bearing load-bearing system 200 to securely fasten the cargo. An adjustable center-of-gravity controller 230 ensures a reasonable distribution of cargo weight between the pallet 320 and the central vertical bearing load-bearing system 200. Through the coordinated action of these components, the entire device achieves convenient loading, secure fastening, and a reasonable distribution of the center of gravity for the cargo.

[0028] like Figure 1As shown, the above-mentioned foldable cargo conversion frame 100 is fixedly installed on the main frame 01, and is connected with the cargo support assembly 300 through the lower tube 015 of the main frame 01 to provide support and stability. The main frame 01 includes a wheel, a front fork 011, a handlebar 012, a seat tube 013, a head tube 014, a lower tube 015, and the like, and constitutes a cargo carrying bicycle similar to the prior patent US11260928B2. The foldable cargo conversion frame 100 mainly includes: two symmetrical folding arms 110 arranged symmetrically, a central folding hinge 120 arranged at a middle position of the two symmetrical folding arms 110 as a folding rotation pivot point, and a folding locking mechanism 130 arranged near the central folding hinge 120 or at a key position of the symmetrical folding arms 110 for locking the unfolded state. Among them, the two symmetrical folding arms 110 are connected with each other through the central folding hinge 120 to form a foldable bearing structure, and the symmetrical folding arms 110 extend along the longitudinal direction of the frame, forming a U-shaped or rectangular cargo bearing space in the unfolded state, and can be folded to a compact state in the folded state to reduce the occupied space; the folding locking mechanism 130 can adopt a latch type, buckle type or bolt type locking structure to ensure that the foldable cargo conversion frame 100 will not be accidentally folded when carrying cargo.

[0029] As shown in Figure 2 and Figure 3 The middle vertical shaft load-carrying system 200 mainly includes a middle vertical shaft 210 and a weight transfer mechanism 220. Among them, the middle vertical shaft 210 is a vertical shaft structure, the lower end of which is fixedly connected to the lower tube 015, and the upper end of which is connected to the weight transfer mechanism 220; the weight transfer mechanism 220 includes a vertical shaft bearing seat 221 which can be adjusted up and down and is positionally locked on the upper end of the middle vertical shaft 210, and a cantilever 222 which can be rotated and positionally locked on the vertical shaft bearing seat 221 and extends outward.

[0030] As shown in Figure 2 and Figure 5As shown, the adjustable gravity center controller 230 is arranged at the upper part of the middle vertical shaft 210, used to realize dynamic adjustment of the gravity center of the goods and control of the weight transfer. The adjustable gravity center controller 230 mainly comprises: a movable upper arm 231 which is a cantilever 222 of the weight transfer mechanism 220 and can rotate up and down around the hinge point, a fixed lower arm 232 which is fixedly installed at the lower part of the middle vertical shaft 210 and corresponds to the movable upper arm 231 in an up-down relationship, an adjusting knob 234 which is rotatably installed on the movable upper arm 231 and can gradually extend the lower end to abut against the fixed lower arm 232 to push the movable upper arm 231 to rotate upward, and a center lifting plate adaptive device 233 which is suspended at the front end of the movable upper arm 231. The center lifting plate adaptive device 233 comprises a center lifting plate 223 and a connecting mechanism. The center lifting plate 223 is a ring-shaped or polygonal plate structure, and a plurality of binding points are arranged on the periphery of the center lifting plate 223 for the ends of the binding belts 401 to be fixedly bound. The center lifting plate 223 is suspended at the front end of the movable upper arm 231 by a universal connection or a guide rail connection. See Figure 6 The position of the goods can be freely adjusted to maintain dynamic balance and ensure that the position of the gravity center of the goods is relatively stable during the up-down movement of the movable upper arm 231.

[0031] As shown in Figure 2 and Figure 5 , the binding belt system 400 is composed of a plurality of binding belts 401, which are used to wrap and fix the goods from multiple directions and connect the goods to the center lifting plate 223. One end of the binding belt 401 is fixed to the outer periphery of the tray 320, and the other end is connected to the corresponding fixed point of the center lifting plate 223. The binding belt 401 can be made of woven belts, nylon belts or other high-strength flexible materials, and has a certain elasticity and tensile strength. In use, after the goods are placed on the tray 320, each binding belt 401 is pulled out from the outer periphery of the tray 320 to wrap the goods. The ends of each binding belt 401 are fixedly bound to the center lifting plate 223, and the goods are firmly wrapped by tightening the binding belts 401. At this time, the main weight of the goods is still borne by the goods supporting assembly 300, but the upper part of the goods has established a connection with the center lifting plate 223 through the binding belts 401, and a small part of the weight of the goods is borne by the center lifting plate 223 and transmitted to the frame through the center lifting plate adaptive device 233 and the middle vertical shaft 210.

[0032] As shown in Figure 5As shown, the weight transfer mechanism of the whole device works as follows: when further stabilization of the cargo is needed, turn the adjustment knob 234 so that the adjustment part of the adjustment knob 234 gradually extends and comes into contact with the upper surface of the fixed lower arm 232. As the adjustment knob 234 continues to rotate, the contact force of the adjustment knob 234 on the fixed lower arm 232 increases, and the moment generated by this force causes the movable upper arm 231 to rotate upward around its hinge point, thereby driving the center hanger tray adaptive device 233 and the center hanger tray 223 as a whole to move upward. Since the center hanger tray 223 is connected to the cargo through the binding belt 401, and the center hanger tray adaptive device 233 has an adaptive adjustment function, during the upward movement of the center hanger tray 223, the binding belt 401 gradually tightens, the center of gravity of the cargo remains relatively stable, but the weight of the cargo gradually shifts from the cargo support assembly 300 to the central vertical shaft load-bearing system 200. This weight transfer mechanism, through the simple operation of the adjustment knob 234, changes the way the cargo weight is borne from mainly relying on the cargo support assembly 300 to mainly being borne by the central vertical shaft load-bearing system 200, so that the center of gravity of the cargo is closer to the center axis of the vehicle frame, reducing the possibility of the center of gravity of the cargo shifting during riding, significantly improving the stability and safety of riding.

[0033] Workflow description: Referring to Figures 1-11, in particular, in use, the operator first unfolds the foldable cargo conversion frame 100 from the folded state to the working state, and locks it through the folding locking mechanism 130. Then the goods to be transported are placed on the pallet 320, and the goods are as close to the center position as possible to facilitate subsequent binding. Then each strap 401 is pulled out from the outer periphery of the pallet 320, and the straps 401 are wrapped around the periphery of the goods in a cross or parallel manner, and the end of each strap 401 is tied to the corresponding fixed point of the center hanger 223, and the goods are firmly wrapped and fixed by tightening the straps 401. At this time, the main weight of the goods is still borne by the goods supporting assembly 300, and the straps 401 mainly prevent the goods from moving and falling laterally. When preparing to start riding, the operator turns the adjusting knob 234, which gradually extends and abuts against the fixed lower arm 232, and continues to turn to slowly lift the movable upper arm 231 upward, driving the center hanger adaptive device 233 and the center hanger 223 to move upward, and the straps 401 are tightened, and the weight of the goods is gradually transferred from the goods supporting assembly 300 to the middle vertical shaft load-bearing system 200. Because the center hanger adaptive device 233 can automatically adjust the attitude of the center hanger 223 according to the actual center of gravity position of the goods, even during the upward movement, the center of gravity of the goods remains in the original stable position, and no obvious inclination or deviation occurs. In this way, part of the weight of the goods is finally borne by the middle vertical shaft load-bearing system 200, and the center of gravity of the goods is closer to the center line of the frame, greatly reducing the risk of vehicle instability caused by the shaking or deviation of the center of gravity of the goods during riding, and enabling the rider to control the vehicle more easily and safely. After transportation is completed, the adjusting knob 234 is operated in reverse, the movable upper arm 231 is lowered, the weight of the goods returns to the goods supporting assembly 300, and the straps 401 are untied to remove the goods, the whole process is simple and fast, and the efficiency of loading and unloading and transporting the goods is improved.

[0034] In a further specific embodiment, the connecting mechanism of the center hanging plate self-adaptive device 233 is in the shape of a ball socket universal hinge, with a circular arc guide groove and a limiting stop structure. Specifically, the connecting mechanism includes a ball head connecting seat fixedly installed at the front end of the movable upper arm 231 and a ball socket connecting piece rotatably sleeved on the ball head connecting seat, and the lower part of the ball socket connecting piece is fixedly connected with the center hanging plate 223. The inner cavity of the ball socket connecting piece is provided with a spherical surface matched with the outer surface of the ball head connecting seat, and a multi-degree-of-freedom spherical hinge connection is formed between the two, so that the center hanging plate 223 can rotate 360 degrees in the horizontal plane and swing at a certain angle in the vertical direction, thereby realizing self-adaptive adjustment to the center of gravity position of irregular goods. The inner wall of the ball socket connecting piece is provided with a circular arc guide groove matched with the guide protrusion on the outer surface of the ball head connecting seat, which plays a guiding and limiting role during the rotation or swing of the center hanging plate 223, preventing excessive deflection. In addition, the circumferential direction of the ball head connecting seat is provided with a plurality of limiting stop blocks, when the swing angle of the center hanging plate 223 reaches the boundary of the preset safety range, the corresponding part of the ball socket connecting piece abuts against the limiting stop block, thereby limiting its continued deflection, ensuring the structural stability and safety of the device when carrying goods. This design enables the center hanging plate 223 to automatically adjust the attitude angle during the upward and downward movement of the movable upper arm 231 and the tightening of the binding belt 401 according to the actual center of gravity distribution of the goods, always keeping the center of gravity of the goods relatively stable, avoiding the risk of overturning due to the shift of the center of gravity.

[0035] In a further specific embodiment, the center hanging plate 223 is provided with a quick locking mechanism at the position where the binding belt 401 is connected, such as a known quick release buckle. Specifically, the outer peripheral edge of the center hanging plate 223 is provided with a plurality of binding belt fixing holes at equal angles, and each binding belt fixing hole is provided with a quick buckle device, which includes a buckle female seat fixed on the center hanging plate 223 and a buckle male head fixed at the end of the binding belt 401. The buckle male head is a protruding buckle structure, and the two sides thereof are provided with elastic clamping jaws. The buckle female seat is a corresponding plug-in hole structure, and the inner wall thereof is provided with a clamping groove matched with the elastic clamping jaws. In use, the operator aligns the buckle male head at the end of the binding belt 401 with the plug-in hole of the buckle female seat, and presses it to insert. The elastic clamping jaws are squeezed and contracted during the insertion process. When the buckle male head is completely inserted, the elastic clamping jaws automatically pop open and are clamped into the clamping groove on the inner wall of the buckle female seat, achieving quick locking. When the binding belt 401 needs to be untied, the operator presses the release button on both sides of the buckle male head to make the elastic clamping jaws contract and separate from the clamping groove, and then the buckle male head can be pulled out of the buckle female seat. Compared with the traditional knot binding method, this quick locking mechanism has the advantages of simple operation, firm fixation and reusability, significantly improving the efficiency of loading and unloading goods. At the same time, each buckle device is also provided with a safety locking pin, which can be inserted after the binding belt 401 is locked to provide a second safety protection, preventing the buckle from being accidentally detached due to vibration or impact during transportation, and further enhancing the reliability and safety of the goods fixation. Embodiment

[0036] Reference Figures 7-9 On the basis of Embodiment 1, the binding belt system 400 is improved and optimized in this embodiment. By arranging a retractable binding belt assembly 500 inside the tray 320, the automatic storage and quick deployment function of the binding belt 401 is realized, further improving the convenience of use of the device.

[0037] As shown in Figure 7 , the retractable binding belt assembly 500 is arranged in the internal space of the tray 320. The binding belt assembly 500 mainly includes: a plurality of rigid rods 520 arranged at equal angles and around the inner peripheral edge of the tray 320, a plurality of elastic belts 510 arranged around the outer peripheral edge of the tray 320 and matched with the rigid rods 520, and a plurality of binding belts 401 connected between the rigid rods 520 and the elastic belts 510. The rigid rod 520 is in the form of an elongated rod and can be made of metal pipe or hard plastic. The elastic belt 510 is an elastic belt body and can be made of rubber, elastic fabric or other materials with good elasticity. The elastic belt 510 is correspondingly installed around the outer peripheral edge of the tray 320, and is in a straight state and kept at the outer peripheral position of the tray 320 in a natural state.

[0038] As shown in Figure 7 and Figure 8As shown, one end of the strap 401 is fixed to the outer end of the rigid rod 520, and the free end of the strap 401 is wrapped multiple times between the rigid rod 520 and the elastic band 510 to form a storage state. Specifically, each strap 401 is led out from the fixed point at the outer end of the rigid rod 520, extends outward to the elastic band 510 to wrap around it, and then is folded and wrapped multiple times between the rigid rod 520 and the elastic band 510 for storage. Finally, the free end of the strap 401 passes through the long groove 321 at the bottom of the tray 320 and extends out of the tray. In the initial storage state, the elastic band 510 is held in its natural position at the outer edge, and the main body of the strap 401 is folded and stored in a compact manner in the space between the rigid rod 520 and the elastic band 510, with only a small amount of the free end protruding from the outside of the tray 320, resulting in a simple and beautiful overall appearance.

[0039] like Figure 8 As shown, when using the strap 401, the operator grasps the free end of the strap 401 and pulls it outwards. The strap 401 gradually unfolds and releases from its folded storage state between the rigid rod 520 and the elastic band 510. As the strap 401 is pulled out, the elastic band 510 is subjected to an inward pulling force, undergoes elastic deformation, and gradually moves inwards from the outer periphery towards the rigid rod 520. The distance between the elastic band 510 and the rigid rod 520 decreases, allowing the strap 401, which was originally folded and stored between the two, to be released smoothly. The operator can pull out a sufficient length of strap 401 according to the size of the goods and the packaging needs, wrap and secure the goods from multiple directions, and then tie and fix the end of the strap 401 to the central hanging plate 223 as described in Embodiment 1. When the strap 401 is not in use, the operator releases the free end of the strap 401. The elastic band 510, due to its own elastic restoring force, springs back outward to its natural state at the outer edge of the tray 320. During the rebound, the strap 401 is folded back between the rigid rod 520 and the elastic band 510, and the strap 401 automatically returns to its stored state. No manual winding or tidying is required, making the operation very convenient. This automatic elastic retraction mechanism effectively prevents the strap 401 from being scattered and dragging outside the tray 320, maintaining the neat appearance of the device and preventing the strap 401 from being caught in the wheel or snagged on obstacles during riding, thus avoiding safety hazards.

[0040] In a further specific embodiment, the bottom of the tray 320 is provided with a long slot 321 for each strap 401 to pass through, and an elastic cover 322 is arranged in the long slot 321. Specifically, the long slot 321 is a long strip-shaped opening extending in the radial direction of the tray 320, and its length is sufficient to allow the strap 401 to pass through smoothly without being hindered during the pulling process. The elastic cover 322 is made of soft rubber or silicone sheet material, with one side fixed to one side edge of the long slot 321 and the other side being a free end. In the natural state, the elastic cover 322 covers and seals the long slot 321 by relying on its own elasticity, preventing dust, rainwater and other foreign matter from entering the tray 320 and polluting the strap assembly 500 inside. When the free end of the strap 401 is pulled outward, the strap 401 pushes the elastic cover 322 to turn outward or retract, and the elastic cover 322 opens or retracts with the movement of the strap 401, allowing the strap 401 to smoothly pass through the long slot 321 and extend outside the tray. When the strap 401 is retracted, the elastic cover 322 automatically returns to the covering state by its own elastic force, resealing the long slot 321. This design not only ensures the smoothness of the strap 401 pulling and retracting, but also effectively protects the strap assembly 500 inside the tray 320 from external environmental factors, prolonging the service life of the device. In addition, the inner surface of the elastic cover 322 can be provided with guide ribs to guide the strap 401 during its passage, preventing the strap 401 from jamming or deviating in the long slot 321. Embodiment

[0041] On the basis of the above-mentioned embodiment 1 or embodiment 2, in this embodiment, the cantilever 222 is positioned and locked in the height direction, and has a controllable rotating movement function in the radial direction of the cantilever 222, i.e. a rotating space is reserved in the vertical bearing seat 221, and the rotation of the cantilever 222 is actively controlled by setting a force applying mechanism, so as to realize dynamic matching adjustment of the center of gravity of the goods and the turning direction during vehicle turning, and further improve the stability and safety of the cargo riding.

[0042] Scheme one: mechanical motor driving scheme The weight transfer mechanism in this embodiment increases the steering control function on the basis of the original structure. A circular rotating groove is arranged in the vertical bearing seat, and a rotating bearing cooperating with the rotating groove is arranged at the hinged end of the cantilever. The cantilever can rotate left and right in the horizontal direction around the axis of the middle vertical shaft, and the rotating range is ±30° to ±45°. A height locking mechanism is arranged on the vertical bearing seat, and the operator can adjust the cantilever to the appropriate height according to the weight and center of gravity of the goods, and then fix it in the height direction by a locking pin.

[0043] The cantilever force applying mechanism is arranged between the vertical bearing carrier and the cantilever, mainly comprising a small motor fixedly installed on the side wall of the vertical bearing carrier, a driving gear connected to the output shaft of the motor, and a passive gear fixed to the hinged end of the cantilever. The driving gear and the passive gear are in mesh with each other. When the motor drives the driving gear to rotate forward or reversely, the passive gear is rotated through the gear transmission, and then the cantilever is driven to swing left and right around the central vertical shaft axis.

[0044] Working principle: In actual riding process, when the vehicle needs to turn, the rider operates the motor through the control button or the lever installed on the handlebar. When turning left, the left control button is pressed, the motor drives the cantilever to swing to the left side, and drives the overall center of gravity of the goods connected by the binding belt to shift to the inside of the turning; when turning right, the right control button is pressed, the motor reversely drives the cantilever to swing to the right side. This active center of gravity adjusting mechanism shifts the center of gravity of the goods to the inside of the turning, generates a balance torque in the opposite direction of the overturning torque caused by the centrifugal force, effectively offsets the instability of the centrifugal force, and makes the vehicle maintain a better balance state during turning, reduces the risk of rollover. After turning is completed, the control button is released or the centering button is pressed, the motor drives the cantilever to return to the middle position, and the center of gravity of the goods returns to the center line of the frame.

[0045] The motor is powered by a battery or a rechargeable lithium battery, and the battery pack is fixedly installed near the frame. The whole electric control system has simple structure, intuitive operation and convenient maintenance.

[0046] Scheme two: manual cable operation scheme This scheme adopts a pure mechanical cable control system, which does not need power driving, and the structure is more simple and reliable. The cantilever can rotate left and right around the central vertical shaft in the horizontal direction, and the hinged end thereof is connected with a left cable and a right cable respectively. The two cables are guided upward along the central vertical shaft and the goods conversion frame to the handlebar position, and two cable control handles are arranged on the handlebar, which are similar to the structure of the bicycle brake handle.

[0047] One end of the left cable is fixed to the left side of the cantilever, is guided through a guide pulley and is connected to the control handle on the left side of the handlebar; one end of the right cable is fixed to the right side of the cantilever, is guided through a guide pulley and is connected to the control handle on the right side of the handlebar. The cable adopts stainless steel wire or high-strength nylon rope, and is provided with a flexible protective sleeve, which can ensure the force transmission effect and prevent the cable from being worn.

[0048] Working principle: When the vehicle needs to turn left, the rider holds and pulls the left handlebar, the left cable is pulled tight and exerts a pulling force on the left side of the cantilever, which makes the cantilever rotate left around the middle vertical shaft, and drives the center of gravity of the goods to shift left. At this time, the right cable is in a relaxed state. When turning right, the operation is the opposite, pulling the right handlebar makes the cantilever rotate right. After turning, the rider releases the handlebar, and the cantilever returns to the middle position naturally under the action of its own gravity and the gravity of the goods, or a reset spring can be added at the hinge of the cantilever to help the cantilever quickly return to the middle. Embodiments

[0049] As shown in Figure 10 and Figure 11 , the folding locking mechanism 130 adopts a spring compression type locking structure, mainly including: a compression spring 131 and a locking seat 132 which are sleeved on the screw rod of the adjusting knob 234 from top to bottom, and two guide rods 133 which are arranged on both sides of the locking seat 132 and extend to both sides along the opening and closing direction of the two symmetrical folding arms 110, and the end of the two guide rods 133 is a spherical structure.

[0050] The working principle is as follows: when the foldable goods conversion frame 100 rotates from the unfolded state to the folded state, the two symmetrical folding arms 110 rotate towards each other around the central folding hinge 120, and the two symmetrical folding arms 110 gradually approach. In the process of approaching, the spherical structure at the end of the guide rod 133 respectively contacts the arm surface of the corresponding symmetrical folding arm 110, and the circular surface of the ball serves as a guide to guide the two symmetrical folding arms 110 into the accommodating space of the locking seat 132. When the two symmetrical folding arms 110 are completely closed in place, the compression spring 131 is in a pre-compressed state, and an elastic pressure is generated downward on the locking seat 132. This pressure is transmitted to the end of the symmetrical folding arm 110 entering its accommodating space through the locking seat 132 and the guide rod 133, so that the two symmetrical folding arms 110 remain in contact with each other under the action of the elastic force, achieving preliminary locking and preventing the foldable goods conversion frame 100 from accidentally unfolding due to slight vibration or external force during normal use.

[0051] If it is necessary to further enhance the locking effect to carry heavier goods or cope with more complex road conditions, the operator can rotate the compression adjusting knob 234 downward, and the screw rod moves downward under the thread cooperation, the knob head further compresses the compression spring 131 sleeved on the screw rod, so that the downward pressure of the compression spring 131 on the locking seat 132 increases significantly. With the continuous rotation of the adjusting knob 234, the locking seat 132 generates a stronger clamping force on the end of the symmetrical folding arm 110 entering its accommodating space under the action of greater elastic pressure, and the connection between the two symmetrical folding arms 110 is more firm and reliable, so that the entire foldable goods conversion frame 100 forms a high-rigidity load-bearing structure, which can stably bear the weight of the goods and various dynamic loads and impacts during the riding process.

[0052] The compressed spring 131 plays a key role in the locking mechanism: its pre-compressed state provides an initial elastic force that realizes the rapid self-locking function of the frame, automatically locking after the folding arms are closed without additional operation; at the same time, the additional compression amount adjustable by the adjusting knob 234 allows the locking force to be flexibly adjusted according to the actual load demand, meeting the convenient operation under light load and ensuring safety and reliability under heavy load. In addition, the continuous elastic pressure of the spring can automatically compensate for the possible connection loosening caused by factors such as vibration and temperature change, ensuring the long-term stability of the locking.

[0053] When it is necessary to unfold the foldable cargo conversion frame 100 from the folded state, the operator first rotates the compression adjusting knob 234 upward in the opposite direction, the screw rod moves upward under the action of the screw thread, the compression amount of the compressed spring 131 decreases, and the clamping force of the locking seat 132 on the symmetrical folding arms 110 decreases. Then, the symmetrical folding arms 110 are forcibly pulled in the opposite direction, overcoming the remaining spring elastic force, so that the end of the symmetrical folding arms 110 is separated from the containing space of the locking seat 132 and the positioning of the guide rod 133, the locking state between the two symmetrical folding arms 110 is released, and then the symmetrical folding arms 110 are rotated in the unfolding direction around the central folding hinge 120, so that the foldable cargo conversion frame 100 can be unfolded to the working state. The entire locking and unlocking process is simple and intuitive to operate, and the spring compression structure not only ensures high reliability in the folded state, but also makes the unfolding operation relatively labor-saving and controllable.

[0054] The above description is only one specific example of the present application and does not constitute any limitation on the present application. Obviously, for those skilled in the art, after understanding the content and principles of the present application, various modifications and changes in form and details can be made without departing from the principles and structures of the present application, but these modifications and changes based on the idea of the present application are still within the protection scope of the claims of the present application.

Claims

1. A center of gravity adjustable cargo carrying rack for a cargo carrying bicycle or electric bicycle comprising a foldable cargo conversion frame (100), a cargo cradle assembly (300) and a strapping system (400), characterized in that, Also include: The middle vertical shaft load bearing system (200) is vertically arranged at the center position of the goods supporting assembly (300), and is used for bearing part of the goods weight. The middle vertical shaft load bearing system (200) comprises: The lower end of the middle vertical shaft (210) is fixedly connected to the frame; The weight transfer mechanism (220) is arranged at the upper part of the middle vertical shaft (210) and comprises a cantilever (222); The adjustable gravity center controller (230) is arranged on the weight transfer mechanism (220), and the adjustable gravity center controller (230) comprises: The movable upper arm (231) can rotate up and down around the hinge point; The adjusting mechanism is used for pushing the movable upper arm (231) to lift upward; The center lifting plate adaptive device (233) is suspended at the front end of the movable upper arm (231) and comprises a center lifting plate (223). The periphery of the center lifting plate (223) is provided with a belt fixing point. The belt system (400) comprises a plurality of belts (401). One end of each belt (401) is fixed to the peripheral surface of the tray (320) of the goods supporting assembly (300), and the other end is connected to the belt fixing point of the center lifting plate (223), which is used for wrapping and fixing the goods. By pushing the movable upper arm (231) to rise through the adjusting mechanism, the center lifting plate (223) moves upward, and the belt (401) tightens, so that the goods weight is transferred from the goods supporting assembly (300) to the middle vertical shaft load bearing system (200).

2. The gravity center adjustable cargo carrier for a cargo bike or an electric bike according to claim 1, characterized in that: The connecting mechanism of the center lifting plate adaptive device (233) is a ball and socket universal hinge structure, which comprises a ball head connecting seat fixed at the front end of the movable upper arm (231) and a ball and socket connecting piece rotatably sleeved on the ball head connecting seat. The lower part of the ball and socket connecting piece is fixedly connected to the center lifting plate (223), and the inner cavity of the ball and socket connecting piece is provided with a spherical surface matched with the outer surface of the ball head connecting seat, so that the center lifting plate (223) can rotate in the horizontal plane and swing in the vertical direction.

3. The gravity center adjustable cargo carrier for a cargo bike or an electric bike according to claim 2, characterized in that: The inner wall of the ball and socket connecting piece is provided with a circular arc guide groove matched with the guide protrusion on the outer surface of the ball head connecting seat. The circumferential direction of the ball head connecting seat is provided with a limiting stop block. When the swing angle of the center lifting plate (223) reaches a preset range, the ball and socket connecting piece abuts against the limiting stop block.

4. The gravity center adjustable cargo carrier for a cargo bike or an electric bike according to claim 1, characterized in that: The adjusting mechanism comprises: The fixed lower arm (232) is fixedly installed at the lower position of the middle vertical shaft (210) and corresponds to the movable upper arm (231) in an up-down relationship. The adjusting knob (234) is rotatably installed on the movable upper arm (231) and gradually extends downward and abuts against the fixed lower arm (232) through rotation, so as to push the movable upper arm (231) to rotate and lift upward.

5. The gravity center adjustable cargo carrier for a cargo bike or an electric bike according to any one of claims 1 to 4, characterized in that, The outer periphery of the center lifting plate (223) is provided with a plurality of belt fixing holes, and a quick locking mechanism is installed at each belt fixing hole.

6. The gravity center adjustable cargo carrier for a cargo bike or an electric bike according to claim 5, characterized in that: The belt system (400) comprises a telescopic belt assembly (500) arranged in the internal space of the tray (320), which comprises: A plurality of rigid rods (520) are arranged around the inner periphery of the tray (320) at uniform intervals; A plurality of elastic bands (510) are arranged around the outer periphery of the tray (320) in correspondence with each rigid rod (520); The number of the plurality of binding bands (401) matches the number of the rigid rods (520) and the elastic bands (510), one end of each binding band (401) is fixed to the outer end of the corresponding rigid rod (520), and the free end of each binding band (401) is wound between the corresponding rigid rod (520) and the corresponding elastic band (510) to form a storage state, when the binding band (401) is pulled, the elastic band (510) moves inward to approach the rigid rod (520), and the binding band (401) is released from the storage state.

7. A gravity centre adjustable cargo carrier for a cargo bike or electric bike according to claim 6, characterized in that: The weight transfer mechanism (220) further comprises a vertical shaft bearing seat (221), the cantilever (222) can rotate around the axis of the middle vertical shaft (210) in the horizontal direction, the vertical shaft bearing seat (221) is provided with a cantilever force applying mechanism, the cantilever force applying mechanism is used to drive the cantilever (222) to swing left and right to adjust the position of the center of gravity of the goods in the turning direction.

8. The gravity center adjustable cargo carrier for a cargo-carrying bicycle or electric bicycle according to claim 7, characterized in that: The cantilever force applying mechanism comprises a motor fixedly installed on the side wall of the vertical shaft bearing seat (221), a drive gear connected to the output shaft of the motor, and a driven gear fixedly installed on the hinged end of the cantilever (222), the drive gear and the driven gear are meshed with each other, and the motor drives the cantilever (222) to swing left and right through gear transmission.

9. A method of controlling the center of gravity of a load during riding using the load carrier according to claim 1, characterized by, The method comprises the following steps: S1: a goods loading and fixing step, placing the goods on the tray (320), pulling out a plurality of binding bands (401) from the outer periphery of the tray (320) to wrap the goods, and fixing the ends of the binding bands (401) to the binding band fixing points of the center hanging plate (223) respectively, at this time the main weight of the goods is borne by the goods supporting assembly (300); S2: a weight transfer step, operating the adjusting mechanism of the adjustable center of gravity controller (230), pushing the movable upper arm (231) to lift upward, driving the center hanging plate (223) to move upward, the binding bands (401) are tightened accordingly, and the weight of the goods is gradually transferred from the goods supporting assembly (300) to the middle vertical shaft load bearing system (200); S3: a center of gravity stabilizing step, during the upward movement of the center hanging plate (223), the center hanging plate self-adapting device (233) automatically adjusts the posture of the center hanging plate (223) according to the actual center of gravity position of the goods, so that the center of gravity position of the goods is relatively stable and closer to the central axis of the vehicle frame; S4: a weight returning step after riding is completed, reversely operating the adjusting mechanism to lower the movable upper arm (231), and moving the center hanging plate (223) downward, so that the weight of the goods returns to the goods supporting assembly (300).

10. The method of controlling the center of gravity of cargo while riding according to claim 9, characterized in that Between the steps S2 and S3, a turning control step is further included: S2.1: when the vehicle needs to turn, the cantilever (222) is driven to swing to the inside of the turning direction by the cantilever force applying mechanism. S2.2: the swing of the cantilever (222) drives the overall center of gravity of the cargo connected by the strap (401) to shift to the inside of the turn, generating a balancing moment opposite to the direction of the centrifugal force; S2.3: after the turn is completed, the cantilever (222) is restored to the middle position, and the center of gravity of the cargo returns to the center line of the frame.

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